YK03-07 Mariana Arc and Forearc Geobiological …...YK03-07 Mariana Arc and Forear c Geobiological...

YK03-07 Mariana Arc and Forearc

Geobiological Expedition Cruise Report

Geobiological investigation of deep-sea hydrothermal field in the TOTO caldera and serpentine seamounts in Mariana Forearc (YK03-07)

August 19, Yokosuka – August 29, Guam, September 1,Guam-September 19, Yokosuka, 2003

Japan Marine Science & Technology Center

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Scientific party

Chief Scientist

Dr. Ken Takai (August 19-September 19)

Vice Chief Scientist

Dr. Kantaro Fujioka (September 1-September 19)

Staff Scientists

Dr. Hisako Hirayama (August 19-September 19)Dr. Yohey Suzuki (August 19-September 19)Dr. Tatsunori NAKAGAWA (August 19-September 19)Ms. Ayako KOSAKA (August 19-September 19)Prof. Dr. Chitoshi Mizota (September 1-September 19)Prof. Dr. Hitoshi Chiba (September 1-September 19)Prof. Dr. Hirokazu Maekawa (September 1-September 19)Dr. Masato Joshima (September 1-September 19)Dr. Kazuhiro Kato (September 1-September 19)Mr. Masumi Sakaguchi (September 1-September 19)

Mairne Technicians Mr. Masayuki Toizumi (August 19-August 29) Ms. Rie Ishi (September 1-September 19)

“Shinkai 6500” Operation Team “R/V YOKOSUKA” Crew Commander Captain

Yoshiji Imai Osamu YUKAWA

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Acknowledgements

We are grateful to Captain Mr. O. Yukawa, Chief Officer T. Aoki and Chief Engineer Mr. K. Tabuchi for their safe navigation and their skillful handling of “R/V Yokosuka”. Great thanks are due to Commander Mr. Y. Imai and “Shinkai 6500” operation team for taking us to deep sea floor and accurate operations in sampling. We also thank Mr. M. Toizumi and Ms. R. Ishii, Nippon Marine Enterprise, Ltd., for their attentive supports.

We thank all the JAMSTEC personnel who have supported us. We also thank Dr. T. Gamo and Dr. J. Tsunogai (Hokkaido Univ.) for technical supports for geochemical analyses.

Finally, we would like to appreciate all the person who supported directly or indirectly this cruise.

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Contents

Acknowledgements 3 Contents 4 List of participants 6

Scientific group 6 Marine Technician 9 “Shinkai 6500” operation team 10 “R/V Yokosuka” crews 10

Manned research submersible “Shinkai 6500” 11 Research vessel “Yokosuka” 12 Outline of SEA BEAM 2112 12 Shipboard Log of YK03-07 14

I. Cruise summary 17

II. Introduction 20 General background and objectives 20 AcidSLiME 20 AlkaliSLiME 23

III. Explanatory note 28 Geochemistry 28 Geophysics 31 Microbiology 32

IV. Dive report 35 #772 (K. TAKAI) 36 #773 (H. HIRAYAMA) 40 #774 (T. NAKAGAWA) 44 #775 (Y. SUZUKI) 47 #776 (T. NAKAGAWA) 51 #777 (K. TAKAI) 54 #778 (Y. SUZUKI) 58 #779 (H. CHIBA) 62

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#780 (K. TAKAI) 66 #781 (K. FUJIOKA) 69 #782 (K. FUJIOKA) 74 #783 (K. FUJIOKA) 78 #784 (H. HIRAYAMA) 82 #785 (C. MIZOTA) 86 #786 (H. MAEKAWA) 89

V. Preliminary results 93 Microbiology 93 Geochemistry 93 Topography and geology 96 In situ measurement using StrataBox 105 Geophysics 110 Petrology 114 Biology 116

VI. Shore base study 119 Geochemistry 119 Microbiology 119 Biology 122 Geology, Geophysics & Geochemistry (Petrology) 122

VII. Appendix 127 Sampling list 127 Printed matters 130

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LIST OF PARTICIPANTS

Scientific Participants

Chief Scientist Dr. Ken Takai Group Leader (Geomicrobiology)Subground Animalcule Retrieval (SUGAR) Project,Frontier Research System for Extremophiles,Japan Marine Science & Technology Center

Vice Chief ScientistDr. Kantaro Fujioka GeologistGeneral Manager of Observation and Research Dept.,Global Ocean Development Inc (GODI)

Dr. Hisako HIRAYAMA Research scientist (Microbiology)Subground Animalcule Retrieval (SUGAR) Project,Frontier Research System for Extremophiles,Japan Marine Science & Technology Center

Dr. Yohey Suzuki Research scientist (Microbiology)Subground Animalcule Retrieval (SUGAR) Project,

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Frontier Research System for Extremophiles,Japan Marine Science & Technology Center

Dr. Tatsunori NAKAGAWA Research scientist (Microbiology)Subground Animalcule Retrieval (SUGAR) Project,Frontier Research System for Extremophiles,Japan Marine Science & Technology Center

Ms. Ayako KOSAKA Graduate Student (Geochemistry)Division of Earth and Planetary Sciences,Graduate School of Science,Hokkaido University

Prof. Dr. Chitoshi Mizota Professor (Geobiologist)Faculty of Agriculture, Iwate University

Prof. Dr. Hitoshi Chiba Professor (Geochemist) Institute for Study of the Earth's Interior Okayama University

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Prof. Dr. Hirokazu Maekawa Professor (Petrologist) Department of Earth and Life Sciences College of Integrated Arts and Sciences Osaka Prefecture University

Dr. Masato Joushima Research Scientist (Geophysist) AIST

Dr. Kazuhiro Kato Assistant Engnieer (Geochemist) Faculty of science, Shizuoka University

Mr. Masumi Sakaguchi Ph.D. student,Department of Geology, Kochi University,

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Marine Technician

Mr. Masayuki TOIZUMI Marine Science Dept.,Nippon Marine Enterprises, LTD.

Mr. Rie ISHII Marine Science Dept.,Nippon Marine Enterprises, LTD.

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“ Shinkai6500” operation team”

Commander Y. IMAI

T. SAKURAI Y. SASAKI T. YOSHIUME I. IIJIMA Y. NANBU H. SHIBATA M. YANAGITANI F. SUDA Y. ONO K. MATSUMOTO H. UEKI Y. CHIDA

“R/V Yokosuka” Crews

Chief Engineer Captain Chief Officer K. TABUCHI O. YUKAWA T. AOKI T. ABE K. KOTO D. GIBU M. TAKAHASI K. KITAMURA Y. ODA S. SASAKI S. TAKUNO K. SHIMIZU T. TOGUCHI Y. FUJIMURA T. SHIRAYAMA K. MIURA M. KITANO H. YAMAMOTO Y. KAWAI K. TODA R. MITSUMORI S. AMAZAKI Y. HAZATANI T. MORITA R. TAKEMURA

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Manned Research Submersible “Shinkai 6500”

Mission of “Shinkai 6500” “Shinkai 6500” able to operate surveys and observations down to the depth 6500 meters with one scientsit and two pilots. During the operation, “Shinkai 6500” finds her position by two ways; Long Base Line system (LBL) and Super Short Base Line system (SSBL). The LBL system needs three bottom-mounted transponders to be deployed in the survey area. “Shinkai 6500” locates her own position by herself in real time and the mother ship determines the position of “Shinkai 6500” based on the position of transponders. The SSBL system does not require any transponder but the accuracy of the posision is inferior to LBL system and “Shinkai 6500” can not determine her own position.

Specifications Length: 9.5m Width: 2.7m Height: 3.2m Weight in air: 25.8t Maximum operation depth: 6500m Complement: 3 (2 pilots and 1 researcher) Inner radius of pressure vessel: 2.0m Normal dive time: 8 hours Life support duration: 129 hours Payload: 150kg (weight in air) Under water speed 0-2.0 knots (Emergency: 2.5 knots) Observation instruments: Pan-tilt-zoom color video camera

Fixed-view color video camera 35mm still camera CTD sensors Gammma ray spectrometer CTFM sonar Video-image transmission system

Operating devices: 2 manipulators 2 retractable baskets

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Research Vessel “Yokosuka”

Mission of “Yokosuka” 1) Operate submersible “Shinkai 6500” 2) Operate underway-geophysical equipments;

Multi Narrow Beam Echo Sounder (Sea Beam 2112.04) Gravity meter (Type S-63) Ship-borne three-components magnetometer (Type SFG-1212) Proton magnetometer (Typ STC10)

Research Facilities In wet laboratory, a fumigation chamber, Mili-Q water purification system, -80˚C and -20˚C freezer, incubator and rock saw. In addition, “Yokosuka” has on-board video editing system for DVCAM, S-VHS and VHS.

Specifications Length: 105.22m Breadth: 16.0m Height: 7.3m Draft: 4.5m Gross tonnage: 4439t Cruising speed: about 16kts Cruising range: about 9000mile

Outline of SEA BEAM 2112

Bathymetric data were collected by the SEA BEAM 2112. The SEA BEAM 2112 is a multibeam survey system that generates data and produces wide-swath contour maps and side scan images. It transmits a sonar signal from projectors mounted along the keel of the ship. The sonar signal travels through the seawater to the seafloor and is reflected off the bottom. Hydrophones mounted across the bottom of the ship receive the reflected sonar signals. The system electronics process the signals, and based on the travel time of the received signals as well as signal intensity, calculate the bottom depths and other characteristics such as S/N ratio for echoes received across the swath. Positioning of depths on the seafloor is based on GPS and ship motion input. The data is

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logged to the hard disk for post processing which allows for additional analysis. Plotters and side scan graphic recorder are also included with system for data recording and display.

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6:04 XBT measurment

Shipboard Log of YK03-07 Date & Time (Ship's time) Note Remarks

Weather / Wind & Sea condition at noon

Tus. 19.Aug.03 15:00 16:00 16:45 19:00

Departure from H.Q. YOKOSUKA Briefing about ship's life and safety KONPIRA ceremony Scientific meeting

transit o / NE 2 (-)

Wen. 20.Aug.03 13:30-14:30

19:00 Scientific lecture for crew and SHINKAI team Scientific meeting

transit bc / NNE 4(2)

Thu. 21.Aug.03 0:00

19:00-21:00 Time adjustment, advance 0.5 hour (UTC+9.5h) Scientific meeting

transit bc / ENE 3(2)

Fri. 22.Aug.03 0:00

19:00-21:00 Time adjustment, advance 0.5 hour (UTC+. 0h) Scientific meeting

transit bc / ESE 3(2)

Sat. 23.Aug.03 6:00

6:40-7:13 9:57

10:05 11:30 16:01 17:07 17:36

arrived at TOTO caldera

pre-site survey SHINKAI on the surface (Dive #772, K. TAKAI) Vent open Landing Leave bottom Arrive at the surface Hetch open Scientific meeting

transit

survey Dive

bc / ESE 3(2)

Sun. 24.Aug.03 9:58

10:04 11:32 16:03 17:10 17:36

SHINKAI on the surface (Dive #773, S. HIRAYAM A) Vent open Landing Leave bottom Arrive at the surface Hetch open Scientific meeting

Dive bc / East 3(1)

Mon. 25.Aug.03 9:56

10:03 11:32 16:02 17:10 17:36

SHINKAI on the surface (Dive #774, T. NAKAGAWA) Vent open Landing Leave bottom Arrive at the surface Hetch open Scientific meeting

Dive bc / SE 2(1)

Tus. 26.Aug.03 9:51 9:58

11:23 15:53 17:03 17:29

SHINKAI on the surface (Dive #775, Y. SUZUKI) Vent open Landing Leave bottom Arrive at the surface Hetch open Scientific meeting

Dive bc / South 2(1)

Wen. 27.Aug.03 9:50 9:55

11:15 16:06 17:17 17:43

SHINKAI on the surface (Dive #776,T. NAKAGAWA) Vent open Landing Leave bottom Arrive at the surface Hetch open Scientific meeting

Dive

transit

bc / ESE 1(1)

Wen. 28.Aug.03 6:00 6:01

6:28-7:09 9:53

10:00 11:28 16:00 17:10 17:34

19:30-20:00

arrived at South Chamorro XBT measurment pre-site survey SHINKAI on the surface (Dive #777, K. TAKAI) Vent open Landing Leave bottom Arrive at the surface Hetch open Scientific meeting

transit

survey Dive

bc / SE 2(1)

Wen. 29.Aug.039:25

9:25-10:25 Arrive at APRA (GUAM) Imiglation

bc /ESE 4(-)

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Date & Time (Ship's t ime) Note Remarks

Weather / Wind & Sea condition at

noon Mon. 2.Sep.07 transit bc / NNW 2

13:05 Departure from APRA(GUAM) 13:00-14:00 Scientific meeting 14:30-15:00 Briefing about ship's life and safety 15:00-16:00 Meeting with SHINKAI6500 Team 19:00-20:00 Scientific meeting 18:55-19:23 Eight Cross Track Survey

19:35 Start Site Survey at Chamoro Area T ue. 3.Sep.07 Dive#778 bc / SW 1

10:38 Stop site Survey at Chamoro Area 9:50 SHINKAI on the surface (Dive #778, SUZUKI)

10:00 Vent open 11:26 Landing 16:09 Leave bottom 17:20 Arrive at the surface 18:43 Site Survey at Chamoro Area

19:00-20:00 Scientific meeting Wen. 4.Sep.07 Dive#779 bc / NW 2

3:19 Stop site Survey at Chamoro Area 9:51 SHINKAI on the surface (Dive #779, CHIBA) 9:57 Vent open

11:24 Landing 15:56 Leave bottom 17:08 Arrive at the surface 18:00 Towing proton magnetmeter 18:27 Site Survey at Chamoro Area

19:00-19:30 Scientific meeting T ur. 5.Sep.07 Dive#780 c / NNW 1

4:55 Stop Geophysical Site Survey 7:03 Recover proton Magnetmeter 9:50 SHINKAI on the surface (Dive #780, TAKAI) 9:57 Vent open

11:21 Landing 16:00 Leave bottom 17:09 Arrive at the surface 18:00 Towing proton magnetmeter

18:10 Site Survey at Chamoro Area Start 19:00-20:00 Scientific meeting

Fri. 6.Sep.07

19:00-20:00 Site Survey at BlueMoon Scientific meeting

Transit bc / SSE 5

Sat. 7.Sep.07 Site Survey 1:56 Stop Geophysical Site Survey 9:37 Site Survrvey start

19:00-19:15 Scientific meeting Sun. 8.Sep.07 Dive#781 c / NNS 5

4:55 Stop Geophysical Site Survey 7:05 Recover proton Magnetmeter 9:50 SHINKAI on the surface (Dive #781, FUJIOKA) 9:57 Vent open

11:42 Landing 15:38 Leave bottom 17:00 Arrive at the surface 17:57 Towing proton magnetmeter 18:08 Start Geophysical Site Survey at Bluemoon

19:00-19:30 Scientific meeting Mon. 9.Sep.07 Dive#782 c / SE3

7:02 Recover proton Magnetmeter 7:21 Stop Geophysical Site Survey at Bluemoon 9:53 SHINKAI on the surface (Dive #782, FUJIOKA) 9:59 Vent open

10:02 Landing 16:10 Leave bottom 16:59 Arrive at the surface 17:54 Towing proton magnetmeter 18:56 Start Geophysical Site Survey at Bluemoon

19:00-19:30 Scientific meeting

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7 : 0 2 Re c o v e r p r o t o n M a g n e t m e t e r

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9 : 5 9 V e n t o p e n

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1 6 : 5 9 A r r iv e a t t h e s u r f a c e

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1 8 : 5 6 S t a r t G e o p h y s ic a l S it e S u r v e y a t B lu e m o o n

1 9 : 0 0 - 1 9 : 3 0 S c ie n t if ic m e e t in g

Tu e. 1 0 . S e p . 0 3 Tr a n s it & b c / EN E

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I. CRUISE SUMMARY

Geomicrobiological expedition was conducted by means of RSV Shinkai6500 and its mother vessel R/V Yokosuka toward a deep-sea hydrothermal field in the Mariana Arc Volcano, the TOTO caldera and Serpentine Sea Mounts in the Mariana Forearc.

In the expedition of the TOTO caldera, the detail mapping of the hydrothermal activities in the Nakayama Field, which was preliminarily surveyed by a single dive of ROV Kaiko in 2000, was achieved. A hydrothermal activity center was located in the south-east edge of the largest mound in the north-east area inside the caldera. The hydrothermal activity center had several white smoker vents, emitting extreme acidic hydrothermal fluids (the maximum temperature measured was 172 ˚C and the lowest pH measured was pH1.59), indicating the world’s lowest pH value of the deep-sea hydrothermal vent known so far. Whole active hydrothermal area was limited in the range (length 400m, width 100m) along the north-south ridge in the edge of the mound. With increasing distance from the hydrothermal center, the surface hydrothermal events shifted to elemental sulfur chimneys accompanying approx. 100 ˚C clear smokers, diffusing clear smoker simmerings and white sulfur sediments. All of the typical hydrothermal fluids were sampled by WHATS water samplers and will be examined with respect to geochemical and isotopic characterizations. The conspicuous physical properties of the hydrothermal fluids in the Nakayama Field might have a great impact on the formation of surface microbial communities and even on the mode of the subsurface microbial communities, so called “Subvent Biosphere”. For microbiological investigations, various excellent samples were collected. These were the little-diluted acidic hydrothermal fluids, intact sulfur chimney structure, systematic plume and ambient seawater, and the STR-ISCS samples. In addition, a variety of hydrothermal animal samples were obtained. Using these excellent samples, the high resolution sketch of the microbial community structures occurring in this system will be completed. In comparison with other deep-sea hydrothermal systems standing on different tectonic and geological settings such as Mid Ocean Ridge, Back-Arc and Hot Spots and even any other Volcanic Arc, geomicrobiology in the global or local deep-sea hydrothermal systems will be well developed. Thus, the expedition to the TOTO cauldron was concluded to be greatly successful.

Despite a great success in the TOTO caldera, the expeditions for the Mariana Forearc Serpentine Seamounts other than the South Chamorro Seamount were terrible. No

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highly alkaline sediments or water sample was successfully recovered. In the South Chamorro Seamount, which was a center of interest before the cruise, most of the chemosynthetic animal communities were about to extinct, indicating the quite low energy and carbon fluxes accompanying with the serpentine upwelling flow. On the summit in the South Chamorro Seamount, almost all the seafloor surface was covered with solid carbonate crust and we were not able to obtain the subseafloor core samples below the carbonate crust. To testify the AlkaliSLiME hypothesis, the highly alkaline subseafloor serpentine mud supposed to be present below at least the anoxic methane oxidation (AMO) zone is necessary. In this cruise, we have had only core sample up to the AMO zone, usually representing the dark layer. The north-west slope, 200 m distance from the summit, was known to be another active serpentine mud flow because of the formation of relatively large chemosynthetic animal communities. It was apparent that the animal community at the north-west slope was drastically decreased since 1997, when Fryer et al. observed a magnitude of vent mussels along a crack of the carbonate crust. First, gray fresh sediments covered the original carbonate crust seafloor and the concomitant animal communities. The gray and fresh sediments appeared to be derived from the boreholes of the Ocean Drilling Project Leg#195, holes 1200 (A-F), operated in 2001, some of which were discovered during this expedition. In addition, several MBARI cores obtained from this site contained organics-rich (especially methylamines-rich) sediments, typical organic materials during the degradation of marine invertebrate animals. These results clearly indicated that the ODP operation had a lethal impact directly or indirectly on the adjacent animal community. The pristine, highly alkaline serpentine mud diffused as cuttings by drilling buried the active animal community and choked or toxified the animals. This is probably a direct and first impact. An indirect possibility is the ODP-induced alteration of upwelling energy and carbon flow. The boreholes of ODP1200 holes might play bypasses for the subsurface pore-water. Then, the highly alkaline methane- or sulfide-rich seepage prior to drilling may move to the ODP1200 borehole bypasses. In this cruise, we obtained potential seepage samples from the summit, the previous animal community site at the north-west slope and the ODP1200E boreholes. In comparison with the previously determined results from Kaiko dive and ODP#195, geochemical and isotopic characterization of carbon sources might shed light on the alteration of upwelling energy and carbon flow before and after the ODP operation. This is the first example of the ODP-induced catastrophic impact on the ecosystem.

The last focus during this cruise was the microbial mat-like structure on the surface of

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the silicate-carbonate chimneys from the Conical Seamount. Onshore investigation will clarify the chmical or microbiological origin of the unique mat-like structure.

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II. Introduction

General background and objectives

AcidSLiME in the TOTO caldra? Recently, there has been an increasing interest in the subsurface biosphere in

the Earth as a potential analogous habitat for extraterrestrial life, particularly in our own Solar System, where liquid water and hydrolithologically provided energy and carbon sources may be more likely present in the subsurface (Stevens and McKinley, 1995; Kasting and Siefert, 2002; Chapelle et al., 2002). Based on terrestrial biology, this is not an unreasonable expectation: on Earth, chemolitho-autotrophic, even methanotrophic and carboxy-dotrophic, microorganisms can gain energy from a variety of reduced inorganic compounds coupling with electron acceptors such as molecular oxygen, nitrate, iron (III), sulphate, sulphur, or carbon dioxide. On today’s Earth, these energy sources are readily generated by biotic processes, and many of them can also be supplied from the earth’s interior directly associated with magmatism in volcanic and hydrothermal fields in tectonic margins and hot spots. In contrast to electron donors, the production of significant quantities of many electron acceptor species such as nitrate, metal oxides and sulphate ultimately requires the involvement of molecular oxygen, and is thus intimately linked to past or present photosynthesis on Earth. Thus, the finding of microbial ecosystems based on chemolithoauto-trophic primary producers utilizing photosyn-thesis-independent energy generation and carbon sources would have implications not only for understanding early earthly ecosystems prior to emerging photosynthetic life, but as models or potential analogs for geochemically active planets or moons. On the basis of geochemical and thermodynamic considerations, a combination of hydrogen and carbon dioxide might be the most abundant and effective energy and carbon sources in our Solar System, nevertheless the detection of subsurface microbial community sustained by chemosynthesis (methanogens or homoacetogens) with photosynthesis-independent, lithospheric hydrogen and carbon dioxide has been equivocal and hotly contested even on Earth.

Such a system was first reported by Stevens and McKinley in the deep crystalline rock aquifers of the Columbia River Basalt Group (CRB) (Stevens and McKinley, 1995). Based on geochemical and isotopic analyses of the groundwater chemistry, in vitro experiments of basalt-groundwater interaction and culture-based evaluation for microbial population of methanogens and acetogens, the authors

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proposed that the microbial ecosystem may be supported by primary production of mesophilic methanogens and acetogens utilizing hydrogen produced from in situ basalt-groundwater geochemical reaction (Stevens and McKinley, 1995). Anderson et al. (1998) argued against the hydrogen-based microbial ecosystems (SLiME hypothesis) in the deep CRB aquifers proposed, citing a lack of evidence supporting the production of hydrogen by the experiments of the basalt-groundwater interactions as proposed by Stevens and McKinley (1995). Subsequently, Chapelle et al. (2002) reported the detection of Archaea-dominating microbial communities in the groundwater system beneath the Lidy hot springs in Idaho by means of a combination of molecular techniques, and concluded that the microbial communities were derived from a hydrogen-based, subsurface lithoautotrophic microbial ecosystem dominated by methanogens. While archaeal rDNA were indeed present, there was no evidence presented either that predominants phylotypes seen were in fact methanogens, or that methanogenesis was in fact occurring, as hypothesized by the authors. In short, there was no cultivation or molecular probing to show abundance of such organisms, there was no isotopic analysis of the methane to suggest a biological origin, and there was no discussion of how a system with nM levels of H2 could be producing mM amounts of CH4.

Perhaps a more promising site for a hydrogen-driven SLiME might be located beneath active deep-sea hydrothermal seafloor in the Mid Oceanic Ridge (MOR) spreading centers. These environments are located in sediment-poor areas, have very little input of organic carbon, and have the opportunity for production of abundant molecular hydrogen and carbon dioxide provided directly from degassing of magma or reaction between water and superheated rock (Figure 1) (Von Damm, 1995). Possible occurrence of microbial communities beneath active deep-sea hydrothermal vent systems (subvent biosphere) has been proposed on the basis of observations of microbial expulsion of hyperthermophiles immediately after submarine volcanic eruptions (Deming and Baross, 1993; Delaney et al., 1998) and of distribution profile of bio-molecules in the deep-sea hydrothermal vent environment (Takai and Horikoshi, 1999; Takai et al., 2001b; Takai and Fujiwara, 2002). Direct measurements to the indigenous microbial communities in the superheated hydrothermal emissions and inside the sulfide chimneys (Takai and Horikoshi, 1999; Huber et al., 2002) and the potential subsurface microbial communities in the core samples penetrating beneath hydrothermal seafloor (Kimura et al., 2003) have also supported the presence of a subvent biosphere. Most of the microbial components determined so far are

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hyper-thermophilic chemolithoorganotrophs obtaining energy from organic compounds probably provided from chemosynthetic microbial and animal communities utilizing photosynthesis-derived electron acceptors (molecular oxygen, nitrate and sulphate) in the relatively surface zone of habitats. Superheated vent emissions, with minimal dilution by seawater, probably entrain the microbial components indigenous to the subsurface hydrothermal water-rock interface in a temperature range permitting microbial growth (up to around 120 ˚C). In such systems, the input of photosynthetically-derived energy and carbon sources will be negligible, and molecular hydrogen and carbon dioxide from the earth’s interior should be primary energy and carbon sources. However, previous studies of undiluted vent emission have shown that it contains limited information about the subvent biosphere because of the paucity of microbial cells and microbial products (Takai and Horikoshi, 1999; Takai et al., 2003), almost certainly due to the very high temperature (>300 oC) inhibition of growth and survival of any entrained microbes.

One approach we have taken to address this problem has been the fabrication of a microbial habitat called an in situ colonization system (ISCS), designed to trap and contain cellular material in the vent waters (Takai et al., 2003). In recent studies of the vent fields of the Central Indian Ridge (CIR), we proved the existence of HyperSLiME beneath a deep-sea hydrothermal system in the Central Indian Ridge (Takai et al., submitted). How about other deep-sea hydrothermal systems such as in volcanic arc or back-arc basins?

As a typical back-arc lifting hydrothermal system, the deep-sea hydrothermal systems in the Okinawa Trough are now extensively investigated. The Suiyo Seamount was also studied but it contained no apparent signature for the possible occurrence of HyperSLiME beneath the seafloor. The most interesting question is whether the Suiyo Seamount represented all other volcanic arc types or an exception?

The TOTO caldera Nakayama field will answer the question because it is an apparent volcanic arc deep-sea hydrothermal activity located in the same Izu-Bonin-Mariana Arc system as the Suiyo Seamount. The TOTO caldera Nakayama field was discovered in 2000 by means of ROV Kaiko dive cruise (Gamo et al., submitted). The hydrothermal fluid chemistry in the TOTO caldera Nakayama field was found to be very unique (strong acidification by magmatic volatiles) and the subseafloor microbial methanogenesis was suggested by carbon isotopic analysis of the gas components in the hydrothermal fluid (Gamo et al., submitted). Thus, the major scientific objective for the Shinkai6500 cruise to the TOTO caldera is to prove whether

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the acidphilic subsurface lithoautotrophic microbial ecosystem (AcidSLiME) is present or not.

AlkaliSLiME in the Mariana Forearc Serpentine Seamount? Deep-sea hydrothermal seafloor and its subseafloor terrain in the tectonic margins

are considered to be the primary regions on Earth where the potential energy and carbon sources for the active subsurface biosphere are constantly provided from the Earth’s interior. However, some places other than hydrothermal systems associated with magmatism, like the subducting oceanic lithosphere occurring in the Mariana Forearc, could serve as a host for SLiME on Earth where the geochemical and mineralogical components are being generated and recycled. Called a ‘Subduction Factory’, the Mariana subduction system composed of the subducting oceanic slab and the upper mantle generates liquid water, carbon dioxide, hydrogen, methane, and other reduced chemical components under much lower temperature conditions than hydrothermal systems, corresponding to the following reactions:

Mg48Si34O85(OH)62 (Antigorite: scaly serpentine) = 14MgSiO4 (Olivine) + 20 MgSiO3

(Enstatite) +31 H2O (fluid) (Dobson et al., 2002)

Peridotites (Olivine, orthopyroxene, clinopyroxene, spinel, garnet) + H2O (fluid) = Serpentine + H2 + Magnetite (O’Hanley, 1996)

During this process, called serpentinization, a part of hydrogen gas may reduce coexisting carbon dioxide to produce methane or hydrocarbon by the Fischer-Tropsch reaction in presence of metal oxides as catalysts (Berndt et al., 1996).

CO2 + 4H2 = CH4 + 2H2O 2CO2 + 3H2 = 2CH2COOH

Although these geochemical reactions occur in deeper zone of the crust near the upper mantle, the chemical products can be upwelled with the serpentine diapir due to their buoyancy. In fact, the geochemical analysis of the sediments and core-liner gases in the south Chamorro seamount, ODP leg. 195 suggested that high concentrations of the C1 through C6 hydrocarbons (presumably produced by the Fisher-Tropsh reaction) were rising upward with deep upwelling fluids (Leg. 195 Shipboard scientific party,

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2002). Such geochemically produced substrates including water, hydrogen, carbonate, methane and hydrocarbons could supply the needed energy and carbon sources for chemolithoautotrophic or hydrocarnonotrophic microorganisms and support the microbial activities in deep subseafloor environments.

Another outstanding physical aspect defining the subseafloor serpentine biosphere is unusual high alkaline pH of the interstitial water (Leg. 195 Shipboard scientific party, 2002), maximally pH12.5 determined in the subseafloor serpentine mud of South Chamorro seamount which is the world’s record of the highest pH value in naturally occurring environments on Earth and exceeds the highest pH limit for growth of life (Takai et al., 2001a). As compared to the generation mechanisms of various hydrolithospheric energy and carbon sources, the formation process of the deep subseafloor alkaline water is still unclear. It is now hypothsized that extra amounts of hydroxyl ion dissociation during the dehydration and serpentinization processes and supersaturated carbonate ions with extraordinary high pressures may cause the highly elevated pH in the serpentine diapir. In addition, the acidifying effect of CO2 and bicarbonate ion may be strongly excluded by the deep upwelling fluids flow. These geochemical settings might provide an extremely alkaline microbial habitats for the deep serpentine biosphere.

On the basis of the geological and geochemical characteristics described above, we hypothesize that an alkaliphilic subseafloor lithoautotrophic microbial ecosystem that we call ‘Alkali-SLiME’ exists beneath the serpentine seamount in the Mariana Forearc. The South Chamorro seamount is located in the southwestern edge of the Mariana foerarc graben and is the only previously known site of active serpentine/blueschist mud volcanism in the world (Fryer, 1996; Fryer and Mottel, 1997). Bathymetric and petrologic features of the serpentine seamounts have been well characterized investigated by dredged holes, submersible dives, and ODP leg.195.

During the ODP leg. 195, a total of six holes were drilled at the south Chamorro seamount (Site 1200). Geochemical analyses and microbiological sampling were performed using three holes, 1200D (22.0 m), 1200E (54.4m), and 1200F (16.3 m). The in situ temperatures in recovered drilled range during Leg. 195 seem to be low for prosperous occurrence of chemolithotroph-dependent, hyper-alikaliphilic microbial ecosystem (eg. 2.0 ˚C at 41 mbsf at 1200A). To sustain an active microbial loop of the deep subseafloor ecosystem starting from primary production by methanogens based on hydrogen geologically provided from serpentinization and re-energized by the subsequent fermentative decomposition, at least moderate temperatures of habitats (>30

24

˚C) are likely necessary since most of the presently known hydrogen-dependent methanogenic and fermentative microorganisms grow well above 30 ˚C. Based on the temperature gradient in the south Chamorro seamount calculated (0.01-0.07 ˚C/m), over 3,000 m depth will be required to prove the hypothesis for the presence of a previously unknown, discrete ‘Alkali-SLiME’ in deep serpentine biosphere. Geochemical products generated by serpen-tinization processes and the Fisher-Tropsh reactions are almost certainly continuously supplied to the environment, where they can be available for the chemolithoautotrophic and hydrocarbonotrophic microorganisms under hyper-alkaline conditions, and we fully expect that such microbial communities will be present in the south Chamorro deep subseafloor environments.

We are now proposing a drilling expedition of AlkaliSLiME that we call: “Deep-STAR (Deep-Subseafloor Traversal for Animalcule Retrieval) Cruise”, at the south Chamorro serpentine seamount in the Mariana Forearc. Preliminary site survey for microbial components, potentially indigenous and entrained from deep subseafloor with upwelling serpentine diapier is an major scientific objective of the Shinkai65000 cruise to the Serpentine Seamounts. The microbiological site survey will proceed the successful future operation of our proposing “Deep-STAR Cruise”.

Anderson, R.T., Chapelle, F.H. and Lovley, D.R. (1998). Evidence against hydrogen-based microbial ecosystems in basalt aquifers. Science, Vol. 281, 976-977.

Berndt, M.E., Allen, D.E. and Seyfried Jr., W.E. (1996). Reduction of CO2 during serpentinization of olivine at 300 ˚C and 500 bar. Geology, Vol. 24, 351-354.

Chapelle, F.H. et al. (2002). A hydrogen-based subsurface microbial community dominated by methanogens. Nature, Vol. 415, 312-315.

Delaney, J.R. et al. (1998). The quantum event of oceanic crustal accretion: impacts of diking at Mid-Ocean Ridges. Science, Vol. 281, 222-230.

Deming, J.W. and Baross, J.A. (1993). Deep-sea smokers: Windows to a subsurface biosphere. Geochim. Cosmochim. Acta, Vol. 57, 3219-3230.

Dobson, D. et al. (2002). Simulation of subduction zone seismicity by dehydration of serpentine. Science, Vol. 298, 1407-1410.

Fryer, P. (1996). Evolution of the Mariana convergent plate margin system. Rev. Geophys., Vol. 34, 89-125.

Fryer, P. and Mottl, M.J. “Shinkai 6500” investigation of a resurgent mud volcano on the Southeastern Mariana forearc. JAMSTEC Deep Sea Res., Vol. 13, 103-114.

Huber, J.A., Butterfield, D.A. and Baross, J.A. (2002). Temporal changes in archaeal

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diversity and chemistry in a Mid-Ocean Ridge subseafloor habitats. Appl. Environ. Microbiol., Vol. 68, 1585-1594.

Kasting, J.F. and Siefert, J.L. (2002). Life and the Evolution of Earth's. Science, Vol. 296, 1066-1068.

Kelly, D.S. et al. (2001). An off-axis hydrothermal vent field near the Mid Atlantic Ridge at 30˚N. Nature, Vol. 412, 145-149.

Kimura, H. et al. (2003). Distribution of microorganisms in the Subsurface of the Manus Basin Hydrothermal Vent Field in Papua New Guinea. Appl. Environ. Microbiol., Vol. 69, 644-648.

Leg. 195 Shipboard Scientific Party. (2002). Mariana convergent margin/West Philippine seaseismic observatory. Proc. ODP Int. Rep. 195.

Mckay, C.P. (2001). The deep biosphere: lessons for planetary exploration. In: Subsurface microbiology and biogeochemistry, J.K. Fredrickson and M. Fletcher (Eds)., Wiley, New York, pp. 315-327.

O’Hanley, D.S. (1996). Serpentinites: Records of petrologic and tectonic history. Oxford Univ. Press, New York.

Shanks, III, K.L. (2001). Stable isotopes in seafloor hydrothermal systems. In: Stable isotope geochemistry, J.W. Valley and D.R. Cole (Eds)., Mineralogical Society of America, Washington DC, pp. 469-526.

Stevens, T.O. and McKinley, J.P. (1995). Lithoautotrophic microbial ecosystems in deep basalt aquifers. Science, Vol. 270, 450-454.

Takai, K. and Horikoshi, K. (1999). Genetic diversity of archaea in deep-sea hydrothermal vent environments. Genetics, Vol. 152, 1285–1297.

Takai, K. and Horikoshi, K. (2000). Rapid detection and quantification of members of the archaeal community by quantitative PCR using fluorogenic probes. Appl. Environ. Microbiol., Vol. 66, 5066-5072.

Takai, K. and Fujiwara, Y. (2002). Hydrothermal vents: biodiversity in deep-sea hydrothermal vents. In: Encyclopedia of Environmental Microbiology, G. Bitton (Ed)., Vol. 3, Wiley, New York, pp. 1604-1617.

Takai, K. and Inagaki, F. (2003). Deep biosphere and hydrothermal activity: potential roles in the co-evolution of earth and life. J. Geography, Vol. 112, 234-249 (Japanese with English abstract).

Takai, K. et al. (2001a). Alakaliphilus transvaalensis gen. nov., sp. nov., an extremely alkaliphilic bacterium isolated from a deep South African gold mine. Int. J. System. Evol. Microbiol., Vol. 51, 1245–1256.

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Takai, K. et al. (2001b). Distribution of archaea in a black smoker chimney structure. Appl. Environ. Microbiol., Vol. 67, 3618–3629.

Takai, K., Inoue, A. and Horikoshi, K. (2002). Methanothermococcus okinawensis sp. nov., a thermophilic, methane-producing archaeon isolated from a Western Pacific deep-sea hydrothermal vent system. Int. J. System. Evol. Microbiol., Vol. 52, 1089-1095.

Takai, K. et al. (2003). Isolation and phylogenetic diversity of members of previously uncultivated -Proteobacteria in deep-sea hydrothermal fields. FEMS Microbiol. Lett., Vol. 218, 167-174.

Von Damm, K.L. (1995). Controls on the chemistry and temporal variability of seafloor hydrothermal fluids. In: Geophysical Monograph 91 Seafloor Hydrothermal System, S.E. Humphris et al. (Eds)., American Geographical Union, Washington DC, pp. 222-247.

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III. EXPLANETAY NOTE

GEOCHEMISTRY

1. WHATS WHATS (Water Hydrothermal Atsuryoku Tight Sampler) has been developed for collecting fluid samples with keeping gas pressure, installed to center of the manned submersible “Shinkai 6500”. Using this equipment, the hydrothermal fluid samples can be collected without mixing with ambient seawater, of which fabrication allows to keep dissolved gasses intact in the container.

This sampling system consists of inlet tubing, four pressure-resistant sample bottles with ball valves at both ends (volume of one bottle: 150 ml), an arm to open and shut the valve and a deep-sea compatible pump. Operation of WHATS is controlled from inside the cabin of “Shinkai 6500”.

2. Water Samples Treatment collected by WHATS Water samples including hydrothermal and cold seep fluid, and bottom ambient

seawater were sampled in this cruise. Water samples collected by WHATS were treated as follows:

(1) Dissolved gaseous component was separated from liquid phase in vacuum after addition of Mercury chloride and Amide sulfate. The separated gas samples will be measured their Carbon isotope ratios and Hydrogen concentration.

(2) Each fluid sample was separated into several aliquot depending on the amount of sample. They include: (a) glass vial for gas components analysis (30ml x 1, 20ml x 3), (b) 5ml polyethylene bottle for pH measurement, (c) 5ml polyethylene bottle for Alkalinity measurement, (d) 8ml Nalgen bottle for major component analysis, (e) glass vial for microbiology (30ml).

(3) Sample (d) was filtered by 0.45µm membrane filter. The filtered fluid was further separated into two aliquot. One will be acidified immediately after its return to the shore laboratory and will be used for cation analyses. Another will be used for the anion analyses. Remaining half of sample (d) will be stored as an archive.

3. Onboard Analyses

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Concentrations of aqueous silica, pH, alkalinity, and salinity were measured onboard in this cruise. 2.1 pH pH of fluid water was measured by Metrhom pH Meter with combined glass electrode,

which are calibrated against NBS Standard solutions of pH=6.88 (20℃) and 4.00 (20℃). Measurements were performed within several hours after recovery on board.

2.2 Dissolved Silica (SiO2) Dissolved silica was measured by colorimetry of molybdate at wavelength 812 nm.

CSK standard solutions (0, 50, 100, 150, 200 μm) were used as a working standard. Analytical Procedure is as follows: (1) Take water sample (0.5ml) in cuvetto, and then add H2O (0.5ml), Molybdate

solution (1.0ml). (2) After standing for 10 to 20 min. (ca.15 min), add reducing solution (1.5ml). (3) Cover the cuvetto with sealon film and shake vigorously and wait for 3 hours. (4) Absorption was measured at 812nm.

2.3 Alkalinity Alkalinity of fluid is measured by Gran titration method according to the following

procedure: (1) Take 5ml of raw fluid sample in a plastic bottle. (2) Adjust pH to 3.5 by titration of 0.1N HCl. (3) Add 0.005ml of 0.1N HCl and record pH and equilibrium voltage. (4) Repeat step (4) at least 10 times. (5) Calculate alkalinity of sample by Gran plot method.

2.4 Salinity Salinity of fluid is measured directly by seawater refraction meter.

2.5 NH4-N NH4-N in fluid is measured by cololimetry at 640 nm according to the following

procedure: (1) Take fluid sample (0.1ml) in cuvetto (2) Add Phenol solution (0.5ml) (3) Add Nitroprusside solution (0.5ml)

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(4) Add Oxidizing solution (0.5ml) (5) Wait at least 1 hour (6) Measurement at 640nm.

4. Treatment of MBARI core pore water for stable isotope analysis Sea-bottom sediments that were collected by MBARI-type corer were sub-sampled

into several sections of every 5 or 10 cm interval from the hole of the MBARI corer wall by insertion of 30mmφ plastic tube minimizing air contact. (1) Center of the section was again sub-sampled by cork borer and transferred into 50

brown vial bottle. The air in the bottle was purged by N2 gas and sealed firmly. (2) The remaining core was transferred into 50ml plastic syringe in which stainless steal

mesh and filtering paper was placed for rough filtration. (3) Sediment in the 50ml plastic syringe was squeezed by a handy vice in refrigerator.

Squeezed pore water was transferred into 10 ml plastic syringe through 3 ways stopcock and 45µm membrane filter.

(4) 1 ml of the squeezed water is transferred into 2 ml Nalgen bottle for measurement of δ13CCH4 and δ13CCO2. Remaining aliquot of squeezed water was stored in 4ml Nalgen bottle for measurements of major chemical composition, δD and δ18O.

4. Treatment of MBARI core pore water for general purpose Written by H.Chiba

Interstitial water was obtained by squeezing from the round sections of MBARI cores. The MBARI core used in this study was shared with Ms. Kosaka of Hokkaido University who will measure CH4 concentration, carbon isotopic ratio etc. After sampling at 5 cm interval for CH4 measurement by 50 ml syringes, remaining whole core was slowly pushed out with pushing rod about 10 cm interval, sampled in plastic bags, and stored in the refrigerator until squeezing. Sediment was taken out from the refrigerator just before the squeezing and scraped from the part of the core with a stainless steel spatula. The scraped sediment was placed in a stainless steel squeezer (Figure). Sediments were squeezed in a Carver hydraulic press at pressures of 300 kg f/cm2 for at least 10, normally 20 minutes (photo). Interstitial water was collected directly from the squeezer into a 20-ml plastic syringe, from which the various aliquots for chemical analysis were ejected through an on-line 0.22 µm membrane filter

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(MillexTM-HA filter unit). Squeezed interstitial water samples were measured for pH, alkalinity and salinity.

The methods for analyses of pH and alkalinity were the same as those of fluid samples. Salinity was measured directry by the hand refractometer (ATAGO S/Mill).

GEOPHYSICS

1. DSTCM(Deep sea Three Component Magnetometer) The equipment was designed for Shinkai 6.5K to obtain 3 component of geomagnetic field near the sea bottom. Flux magnetic sensor and control unit are separately settled in 2 anti-pressure cases and put out 3 component magnetic values every 1/8 second. Data of gyro compass, inclinometer(pitting and rolling) are recorded in Shinkai 6.5K. We can process the corrected geomagnetic field data from these data by post processing. Magnetometer: resolution 1nT, accuracy < 200 nT (for total field intensity), Measurement range +-99999 nT, measurement interval 8 Hz, Anti-pressure case capability 6500m, 196mm dia. x 330mm and 196mm dia. x 700mm, Weight 11kg(6kg in water) for sensor, 22kg(14kg in water) for control unit Power 12V DC, RS232C interface 9600 BPS, 8bit, 1 stop bit, non-parity, serial, For Gyro-compass and inclinometer see the explanation of Shinkai 6.5K equipment.

2. StrataBox sub-bottom profiler The StrataBox™ is a portable, low power, high-resolution, and water-resistant marine sediment imaging instrument, manufactured by OCEAN DATA EQUIPMENT CORPORATION, capable of delivering 6 cm of marine sediment strata resolution with bottom penetration of up to 40 meters. It is designed exclusively for inshore and coastal geophysical marine survey up to 150 meters of water depth and operates at 10 kHz , for ordinary shallow-water-type transducer. Included with the StrataBox™ product is the following: ˎˎ StrataBox™ Sensor Unit

ˎˎ StrataBox™ Transducer Assembly

ˎˎ StrataBox™ Installation CD

ˎˎ StrataBox™ Manual

StrataBox™ Sensor Unit provides all of the transmit/receive electronics, and all of the signal processing functions. It is powered from a 10-30VDC source and consumes 8

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watts of power. It interfaces to the Host PC via a single COM port. The mechanical case for the Electronics Unit is Water Resistant to the EN60529 IP65 Specification and is also UV Stable and Chemical Resistant. The StrataBox™ Transducer Assembly for deep sea is a cylinder, 24cm in diameter, and 20cm in height, covered with rover and attached to horizontal flame using several bolts. The ring provides a means to affix the transducer to the appropriate mounting hardware. The transducer itself provides 300 Watts of Low Frequency energy for bottom penetration of up to 40 meters (sediment dependent). It is lightweight and well suited for portable applications. The StrataBox™ Installation CD will install the PC software used to configure, control, and acquire data from the StrataBox Sensor device. It will also include this manual in PDF format and any Release Notes that have been generated. A hardcopy of the StrataBox™ Manual is also included so that the user may learn to install, operate, and maintain the StrataBox™ Equipment and Accessories. The manual also includes a section on acoustic theory. The StrataBox PC software was designed for use with the Windows 98 operating system, but should operate under Windows 95/ME/NT/2000/XP also. We recommend the software be used on a PC with a processor speed of at least 266 MHz. The software requires at least 1 available Serial Port for connection to the StrataBox instrument, and optionally, additional Serial Ports for NMEA Navigation/GPS Input, NMEA Depth Out, and External Annotation. The software features Navigation Input, External Annotation, Data Storage, Zoom Modes, Thermal Printer output, Automatic/Manual Eventing, and more. The StrataBox software interface is divided into two fields. The Controls field is located on the left and contains navigation/depth information, configuration buttons, and system status. The Data field is located on the right and contains the actual acoustic echo data.

MICROBIOLOGY

1. Subsampling procedures For enrichment and MPN (Most Probable Number) cultivation analyses, water

samples collected by Niskin and WHATS were immediately collected in sterilized glass vials on board, and then, if needed, added sodium sulfide (final conc. 0.05%) and filled headspace with nitrogen gas. For molecular ecological analyses, microbial components in water were concentrated using 0.22µm-pore size 25mm or 45mm cellulose acetate filters. Then, the filters were stored at –20˚C for molecular phylogenetic analysis and at 4˚C with 5% formaldehyde for FISH (Fluorescence In Situ Hybridization) analysis.

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Sea-bottom sediments that were collected by MBARI-type corer were subsampled into several sections in every 5 cm by 50 ml syringe or a push bar and each section was tripatitioned. For enrichment and MPN analyses, sediment sample in 50 ml syringe was further subsampled by 3 ml syringe and 2 ml of sediment was putted into glass bial with filter-sterilized anaerobic seawater that contained sodium sulfide (final conc. 0.05%). Furthermore, the headspace was filled with nitrogen gas and stored in 5˚C incubator. For the RNA based molecular phylogenetic analyses, sediment sample in 50 ml syringe was transferred into 50 ml plastic tube, freezed in liquid nitrogen and stored in –80 ˚C freezer. On the other hand, sample for DNA based molecular phylogenetic analyses and determining biomass was pushed out from corer by push bar, putted into 50 ml plastic tube or vinyl bag and stored in –20˚C freezer.

Chimney samples were subsampled into several sections (e.g. vent orifice surface, inside structure, middle-inside structure). Preparation of slurry and preservation for DNA based molecular analyses were performed as described for sediment samples.

2. STR-ISCS In order to demonstrate the possible existence of hyperthermophilic

microorganisms in >300˚C vent emission, which likely transported through as active microbial populations from subvent biosphere, the in situ colonization system (ISCS) was developed. This system consisted of stainless steel vessels and matrices, which might be newly given habitat for hyperthermophiles with vast surface area. The various candidates for matrices were tested in advance. Finally, we use pumice containing low proportion of aluminum. The vessels are created for fitting with vent orifice diameters. The vessels and matrices were sterilized by heating at 400˚C for 4 days. Any nucleic acids and microorganisms were removed. Then, bringing these ISCS with submersible dives, we place several ISCS in designed microhabitats such as vent emission and surrounding microhabitats. After several days or weeks, ISCS is retrieved by another dive and applied to shore based experiments.

However, it is not completely demonstrated whether ISCS was incubated at >300˚C during all the time of deployment. For conquering this query, we developed ISCS and named STR-ISCS (Self Temperature Recorder – In Situ Colonization System) that consists of ISCS and temperature probe with automatically recording system. The first system of STR-ISCS called Anomalocaris was developed and brought to deep-sea hydrothermal vents in 2002 but she had some troubles in operation. Thus, we further developed second type STR-ISCS and use it on this cruise. The data logger (4.1cm Ø x

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25.5 cm) is hydrostatic pressure resistant up to 60 Mpa for 6000 m deep-sea hydrothermal vent fields. The temperature probe that is 38cm in length is able to resist up to 400˚C, and the code between data logger and temperature probe is exchangeable and the length are 20 – 100 cm. The data were transported into PC after retrieval onboard and memory limit are enough to measure the temperature in such a manner as 1 time per 1minute for 6 months.

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IV. DIVE REPORTS

#772 Dive (TOTO Caldera) Dr. K. Takai #773 Dive (TOTO Caldera) Dr. H. Hirayama #774 Dive (TOTO Caldera) Dr. T. Nakagawa #775 Dive (TOTO Caldera) Dr. Y. Suzuki #776 Dive (TOTO Caldera) Dr. T. Nakagawa #777 Dive (South Chamorro Seamount) Dr. K. Takai #778 Dive (South Chamorro Seamount) Dr. Y. Suzuki #779 Dive (South Chamorro Seamount) Dr. H. Chiba #780 Dive (South Chamorro Seamount) Dr. K. Takai #781 Dive (Blue Moon Seamount) Dr. K. Fujioka #782 Dive (Celestial Seamount) Dr. K. Fujioka #783 Dive (Big Blue Seamount) Dr. K. Fujioka #784 Dive (Pacman Seamount) Dr. H. Hirayama #785 Dive (Conical Seamount) Dr. C. Mizota #786 Dive (Coni-Pac Triangle) Dr. H. Maekawa

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Dive Report: SHINKAI 6500 Dive #772

Date: 23 August , 2003 Site: TOTO Caldera Nakayama Field Landing: 11:30; 12°42.8691'N, 143°32.2339'E, 2970m Leaving: 16:00; 12°42.7892'N, 143°32.3407’ E, 2911m Observer: Ken Takai (SUGAR Project, JAMSTEC) Pilot: K. IIjima, Co-Pilot: T. Ono

Objectives: Two major objectives are underlying on this dive 759: 1) mapping hydrothermal activities in the Nakayama Field in the TOTO caldera 2) sampling hydrothermal fluids and deploying STR-ISCS in the main hydrothermal sites.

Dive Summary: We landed at approximately 100m from a top of the mound in the Nakayama Field. Just before landing (7 m above), the first Niskin water sample was obtained. During the descendance, we observed the turbid water at around 2500m, might be hydrothermal plumes, corresponding to the depth of the surrounding peaks of the TOTO caldera. After landing, we run to the Kaiko #163-2 marker, called “Dancing Galetheids Site”. It was steep ascend. In the way to the Kaiko #163-2 marker, several white sulfur flow were observed. Beyond the wide white sulfur mat, we encountered the first hydrothermal animal communities consisting of tubeworms and shrimps and many other animals. Then, we landed on the tubeworms’ colony and obtained Niskin water sample just above colony. In addition, we took a bundle of tubeworms (but they were dead). 10 m away to East, there was the top of the mound and many gaps were observed in the east-west direction. Many simmering sites were observed in the gaps. From one of the simmering site (12°42.8139'N, 143°32.3304’ E, 2923m), WHATS water sample was obtained. The temperature of the simmering water was max. 22 ˚C and an average of 20 ˚C. Two bottles were sampled. Marker#71 was settled. Over the ridge (north-south direction), the east side was very steep slope and sometimes cliff. We went down to the valley after the ridge. From the bottom of the valley, we went up along the slope to east. This slope was covered with igneous rocks (andesite or basalt) and no apparent hydrothermal activity was observed. At a depth of 2920m, we turned to the southwest and headed to the large depletion. At a terrace in the way to the bottom of the depletion,

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we found the white sulfur-covered sediments (12°42.6734'N, 143°32.3978’ E, 3060m). Two MBARI cores were retrieved. We loitered around the depletion but hydrothermal activity was not apparent. Finally, we went to the ridge for additional hydrothermal fluid sampling. Along the ridge, the east side of the ridge was heavily collapsed. It was expected that the depletion was formed by giant collapse of the subsurface magma chamber in the past. We found another hydrothermal simmering site (12°42.8007'N, 143°32.3415’ E, 2922m). There, we took WHATS sample (2 bottles), Bag sample (2.8 L) and several rocks located in the hydrothermal fluid passage. In addition, we deployed the STR-ISCS (No. 2), lay on the simmering. The hydrothermal fluid was max. 78 ˚C and an average temperature was 65 ˚C. A marker #72 and a homer were settled around the STR-ISCS. This was the last mission of this dive.

Keywords: Volcanic arc, hydrothermal simmering, sulfur mat, STR-ISCS

Payloads: 1) WHATS with a temperature probe for fluid sampling 2) Bag pomp sampler 3) Sample box x2 4) MBARI core sampler 35cm x2 (MY; Yellow, MG, green) 5) Niskin bottle x2 6) STR-ISCS-1, -2 7) ISCS-4 8) Kumade 9) Homer x1 10) Marker x3

Location of Events: Time Position Depth Event 11:30 12˚42.8691'N, 143˚32.2339'E, 2970m Landing on rock floor (t = 1.7˚C)

Niskin No. 1 12:03 12˚42.8213'N, 143˚32.3223'E, 2923m Found tubeworm colony,

Sampling tube worms Niskin No. 2

12:34 12˚42.8139'N, 143˚32.3304'E, 2921m Found hydrothermal simmering

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WHATS 1 and 2 (max. 22 ˚C) (average. 20 ˚C)

13:59 12˚42.6734'N, 143˚32.3978'E, 3060m MBARI core 16:00 12˚42.8007'N, 143˚32.3415'E, 2922m WHATA 3 and 4 (max. 78 ˚C)

(an average of 65 ˚C) 2.8 L Bag water sample STR-ISCS No. 2

16:01 12˚42.7892'N, 143˚32.3407'E, 2911m Leaving the bottom

Video Digest: 12:19:00 CAM2 The first WHATS sampling site

15:40:45 - CAM2 Deployment of STR-ISCS-2

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Dive#772 Observor: KenTakai (JAMSTEC)

Time Position Depth Event Latitude Gratitude

10:05 0 Vent open 11:24 121 420 2964 White Niskin sampling at 7m above the bottom 11:30 130 420 2970 Landing 11:33 Head to KAIKO marker #3? 11:42 80 490 2911 11:47 40 560 2922 Found tubeworm -like 11:49 Found tube warm colony (dead colony?) 11:54 39 586 2923 Sampling tube worm 12:00 Settle #71 marker 12:03 Red Niskin sampling 12:09 40 591 2921 Found shimmaring water 12:20 18 596 2927 Start WHATS sampling (first) of 20° C water 12:27 2921 Finish WHATS sampling (first) of 19° C water 12:34 32 594 2921 Finish WHATS sampling (second) of 19.5° C water

Strat the settle of STR-ISCS(#1) 12:47 Give up the settle of STR-ISCS 12:59 -10 740 3031 Found hole 13:38 -241 715 3062 Found smoker-like turbidity 13:39 -241 715 3062 Found fracture 13:51 -230 720 3060 Trying to sample the yellow MBARI (Success?) 13:57 -227 724 3060 Trying to sample the green MBARI (Success) 14:11 -400 690 3037 14:29 -300 600 3041 14:37 -90 670 2991 14:49 2 616 2922 Found tubeworm. Observing around there. 14:59 7 608 2922 Start WHATS sampling 15:11 Finish WHATS (Third) sampling (58-75° C) 15:18 -1 619 2921 Finish WHATS (forth) sampling (60° C) 15:29 10 614 2922 Start pump-sampling of water 15:37 2 595 2922 Trying the settle of STR-ISCS (#2?) 15:54 2912 Settled Homer 27 and marker #72 16:00 -19 619 Leave the bottom

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Date: 24 August , 2003 Site Name: TOTO Caldera Nakayama Field Landing: 11:32; 12°42.6429'N, 143°32.3632'E, 3059m Leaving: 16:03; 12°42.7402'N, 143°32.3103’ E, 2950m Observer: Hisako Hirayama (SUGAR Project, JAMSTEC) Pilot: T. Yoshiume, Co-Pilot: T. Sakurai

Objectives: Two major objectives are underlying on this dive 773: 1) mapping hydrothermal activities in the Nakayama Field in the TOTO caldera 2) sampling hydrothermal fluids and deploying STR-ISCS in the main hydrothermal sites.

Dive Summary: During a descent to the bottom, the densely turbid water (hydrothermal plumes)

was observed between 2550-2850m and the first Niskin water was sampled at 2571m (12°42.6521' N, 143°32.3822’ E). We landed at the bottom of the depression (12°42.6429' N, 143°32.3632’ E, 3059m), 300m south-southeast from a top of the mound in the Nakayama Field. We headed north-northwest ascending a steep slope. On the way of the ascending, we found a few of shrimps, dead tubeworm colonies and sea anemones, and then found small Calyptogena colonies at 2973m, where four Calyptogena were sampled (12°42.7114' N, 143°32.3286’ E). When we ascended further away to the north, several white sulfur flows began to appear. Next, hydrothermal animal communities consisting of tubeworm, galetheids, shrimps etc. and sulfur chimneys appeared (12°42.7396' N, 143°32.3260’ E, 2943m). The simmering water was observed from the most sulfur chimneys, a few of the chimneys vigorously emitted hydrothermal water. The hot waters were simmering from the whole of this chimney site, and the position of Shinkai 6500 could not be stabilized because of the ascensional flow. During re-access to the sulfur chimney site, we lost the sulfur chimney site. We were going further north to follow the dense hydrothermal plume, and reached a marker #72 site, where the STR-ISCS (No.2) was settled in the dive #772 (12°42.8007'N, 143°32.3415’ E, 2922m).

We headed south to go to the sulfur chimney site again. At 120 m south from a marker #72, we found sulfur chimney site (12°42.7371'N, 143°32.3341’ E, 2945m). At

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the active sulfur chimney which was vigorously emitting hydrothermal water, max. 96°C water was obtained by WHATS sampler (2 bottles). Bag-water (15L) was sampled 30 cm above the simmering site. At another sulfur chimney, max. 103°C of WHATS water was sampled (2 bottles), and deployed STR-ISCS (No.1) in the chimney. A marker #73 was settled 5m above the STR-ISCS. Since sulfur chimneys were very crumbly, manipulator of the Shinkai 6500 could not grapple them. A scoop was used to sample the crumbled sulfur chimney. At 15m north of a marker #73, living tubeworms and a rock were sampled (12°42.7461N, 143°32.3354’ E, 2935m). Around there, fissures with north-south direction were observed. .

After leaving the bottom, the second Niskin water with no turbidity was sampled at 2840m (12°42.7487N, 143°32.3111’ E).

Keywords: Sulfur chimney, hydrothermal water, STR-ISCS

Payloads: 1) WHATS with a temperature probe for fluid sampling 2) Bag pomp sampler 3) Niskin bottle x2 4) Sample box x2 5) MBARI core sampler 35cm x2 (MY; Yellow, MG, green) 6) STR-ISCS-1 7) ISCS-4 8) Scoop 9) Marker x3

Location of Events: Time Position Depth Event 11:07 12˚42.6521'N, 143˚32.3822'E, 2571m Niskin No.1 sampling 11:32 12˚42.6429'N, 143˚32.3632'E, 3059m Landing on rock floor (t = 1.7˚C)

12˚42.8213'N, 143˚32.3223'E, 2923m Found Calyptogena colony, Sampling four Calyptogena

12:40 12˚42.7396'N, 143˚32.3260'E, 2943m Found active sulfur chimneys and tubeworm colony

15:28 12˚42.7371'N, 143˚32.3341'E, 2945m Found active sulfur chimneys

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and tubeworm colonyWHATS 1 - 2 (max. 97 °C)(average. 92°C)WHATS 3 - 4 (max. 103 °C)(average. 102°C)15L Bag water sampleSTR-ISCS No.1Chimney sampling

15:53 12˚42.7461'N, 143˚32.3354'E, 2935m Tubeworm sampling 16:03 12˚42.7402'N, 143˚32.3103'E, 2950m Leaving the bottom 16:05 12˚42.7487'N, 143˚32.3111'E, 2840m Niskin No.2 sampling

Video Digest: 11:56:18 CAM2 Calyptogena sampling site

14:00:00 - CAM2 Sulfur chimney site WHATS sampling Bag-water sampling Deployment of STR-ISCS-1 Sulfur chimney sampling Tubeworm sampling

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Dive#773 Observor: Senko Hirayama (JAMSTEC)


10:05 Vent open 11:05 11 2500 Found plume 11:07 -277 692 2589 NISKIN (red) 11:33 -290 660 3059 Landing (2.7_C)

-210 620 Found clam's colony 12:15 -210 620 2973 Collect clams 12:32 -159 547 2655 Found cold seep 12:41 -141 558 2945 Found chimey 12:57 -81 597 2924 Found plume 13:09 0 590 2924 Found Homer and flying shrimp 13:11 -6 612 2919 Found Homer 13:25 -110 630 2952 13:30 -123 617 2945 Found chimey 13:34 -145 619 2952 Found chimney colony 13:44 -130 600 2949 #73 Mkr 13:56 -120 594 2949 Max. 96_C 14:03 WHATS (#1) 97_C 14:17 WHATS (#2) 14:18 Water (Bag) 14:43 2947 102_C 14:50 2947 WHATS (#3, #4) 102_C 15:06 Sampling rock 15:14 ISCS (#1) 15:28 -120 610 2945 #74 Mkr 15:41 -164 646 2935 tube worm 15:53 -100 610 2937 Collect tube worm and rocks 16:03 -110 560 2950 Left bottom 16:07 -54 558 2650 NISKIN (white)

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Date: 25 August , 2003 Site Name: TOTO Caldera Nakayama Field Landing: 11:32; 12°42.7219'N, 143°32.2424'E, 2992m Leaving: 16:00; 12°42.7392'N, 143°32.2927’E, 2943m Observer: Tastunori Nakagawa (JAMSTEC) Pilot: Y. Sasaki, Co-Pilot: M. Yanagitani

Objectives: Two major objectives are underlying on this dive 774: 1) mapping hydrothermal activities in the Nakayama Field in the TOTO caldera 2) sampling hydrothermal fluids and chimney in the main hydrothermal sites.

Dive Summary: After sampling of Niskin water at 2000 m depth and observation of plum below 2600 m depth, we landed at approximately 100m from a top of the mound in the Nakayama Field. We ran to the #73 marker. The white sulfur mat, simmering water, a lot of sulfur chimneys, and many shrimps occurred around the #73 marker. Then, the sulfur chimney was collected with the novel chimney sampler so-called “Guillotine Cutter” at this site (12°42.7237'N, 143°32.3367'E, 2951m). After disintegration of the chimneys, two WHATS water samples (#1 and #2) were obtained from the fluids at the near site (12°42.7338'N, 143°32.3547'E, 2965m). The temperatures of the fluids were max. 81 ˚C and an average of 75 ˚C, and max. 87˚C and an average of 86˚C, respectively. After running to west and disintegration of the chimneys, two WHATS water samples (#3 and #4) were obtained from the fluids those near site (12°42.7336'N, 143°32.3416'E, 2951m). The temperatures of the fluids were max. 96 ˚C and an average of 87 to 95 ˚C, and max. 100˚C and an average of 92˚C, respectively. In addition, bag sample (10 L) was obtained from the same fluid. After leaving form the fluid (2 m), Niskin water was obtained. Several animals and rocks were collected. This was the last mission of this dive.

Keywords: sulfur chimney, Volcanic arc, hydrothermal simmering, novel chimney sampler

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Payloads: 1) WHATS with a temperature probe for fluid sampling 2) Bag pomp sampler 3) Sample box x2 4) MBARI core sampler 35cm x2 (MY; Yellow, MG, green) 5) Niskin bottle x2 6) Marker x3 7) Chimney sampler so-called “Guillotine Cutter”

Location of Events: Time Position Depth Event 10:51 12˚42.7053'N, 143˚32.2265'E, 2000m Niskin (Red) 11:32 12˚42.7053'N, 143˚32.2265'E, 2992m Landing (t = 1.7˚C) 13:35 12˚42.7237'N, 143˚32.3367'E, 2951m Sampling chimney 14:43 12˚42.7338'N, 143˚32.3547'E, 2965m WHATS 1 and 2

(#1, max. 81 ˚C; average. 75 ˚C) (#2, max. 87 ˚C; average. 86 ˚C)

15:37 12˚42.7336'N, 143˚32.3416'E, 2951m WHATS 3 and 4 (max. 78 ˚C) (#3, max. 96 ˚C; average. 87-95

˚C) (#4, max. 100 ˚C; average. 92 ˚C)

Water bag NISKIN (white)

15:57 12˚42.7356'N, 143˚32.3321'E, 2945m Sampling animals 16:02 12˚42.7392'N, 143˚32.2927'E, 2943m Leaving the bottom

Video Digest: No.2 CAM 13:04:45 Sulfur chimney was collected with the chimney sampler.

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Dive#774 Observor: Tatsunori Nakagawa (JAMSTEC)


10:03 Vent open 10:51 -174.5 409.9 2000 NISKIN (red) 11:03 2500 Found plume 11:33 -144 440 2992 Landing 11:59 -380 450 2958 Found chimney-like structure 12:29 -105 577 2949 Found ballast #773 12:52 -140 610 2952 Found chimney colony 13:01 -137 610 2952 Reached bottom 13:09 -137 610 2952 &ollect chimney with "Girochin" sample 13:35 -140 610 2952 97 C 14:15 -135 635 2965 WHATS (#1) 86_C 14:22 -135 635 2965 WHATS (#2) 86_C 15:08 -120 620 2951 WHATS (#3) 93_C 14:47 -120 620 2951 WHATS (#4) 93_C 15:25 -120 620 2951 Pump water 15:39 -122 618 2949 NISKIN (white) 15:47 -120 600 2946 Collect fauna 16:00 -120 600 2945 Collect rock 16:03 -120 600 2945 Left bottom

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Date: 26 August , 2003 Site Name: TOTO Caldera Nakayama Field Landing: 11:23; 12°42.7063'N, 143°32.2061'E, 3010m Leaving: 15:53; 12°42.7532'N, 143°32.2742’ E, 2969m Observer: Yohey Suzuki (SUGAR Project, JAMSTEC) Pilot: Y. Nanbu, Co-Pilot: K. IIjima

Objectives: Two major objectives are pursued on this dive 775: 1) mapping hydrothermal activities in the Nakayama Field in the TOTO caldera 2) sampling hydrothermal fluids, seawater, chimneys and macrofauna.

Dive Summary: On the way to the bottom, we collected the Niskin water at 1000 m. We also observed the plume at ~2500-2800. We landed approximately 100m southwest of the sulfur chimney site found in the previous dives. We went south to find unknown hydrothermal activities. At the beginning of climbing the slope, we saw the bottom covered with brecciated igneous rocks. Near the top of the slope, we found huge intact igneous rocks (cooled lava). We turned back south to get to the mound on the slope of which the sulfur chimney site was found. On the top of the mound, we fortunately ran into a site where numerous white smokers were being vented. We measured the temperatures of the white smoker fluids and the maximum and average temperatures were 170 ˚C and 120 ˚C, respectively. We collected the white smoker-bearing fluid by using WHATS (#1 and #2) and the pump water sampler (2 L). By using a cylindrical sediment sampler, the solidified surface sediments were collected from the white smoker vent from which the WHATS and bag pump samples were collected. We went further north and found a site covered with massive tubeworm colonies. Suddenly, we encountered a vertical collapse of the mound. The collapse of the mound has been referred to as the “crater site” from the past dive by using the Kaikoh vehicle. Clear hydrothermal fluids were simmered intensively from the bottom of the collapse. Although we attempted to measure the temperatures of the fluids, we were unable to reach the fluids. In the massive tubeworm colonies, organisms that resemble to tubeworms in their appearance, but has a white hairy head periodically coming our and

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going in. We collected the five tubeworm-like organisms (referred to also as barnacle-like organism) by using the manipulator. Afterwards, we searched around the mound and found no other significant hydrothermal activities. Then we left the bottom.

Keywords: hydrothermal simmering, white smokers, mound collapse, barnacle-like organism

Payloads: 1) WHATS with a temperature probe for fluid sampling 2) Bag pomp sampler 3) Sample box x2 4) MBARI core sampler 35cm x2 (MY; Yellow, MG, green) 5) Niskin bottle x2 6) Chimney sampler 7) Cylindrical sediment 8) Kumade

Location of Events: Time Position Depth Event 10:21 12˚42.6980'N, 143˚32.2308'E, 1000m Niskin No. 1 11:23 12˚42.7063'N, 143˚32.2061'E, 3030m Landing on rock floor (t = 1.7˚C) 14:40 12˚42.7700'N, 143˚32.3435'E, 2936m Found hydrothermal simmering

WHATS 1 and 2 (max. 170 ˚C) (average. 120 ˚C) 2 L Bag water Core sample

15:45 12˚42.7801'N, 143˚32.3424'E, 2927m Found the crater site 15:22 12˚42.7801'N, 143˚32.3424'E, 2927m Found barnacle-like organism 15:53 12˚42.7532'N, 143˚32.2742'E, 2922m Leaving the bottom

Video Digest: 13:15-46 CAM2 The finding of white smokers (max temp. 172 C) and WHATS sampling 14:45-56 CAM2 The finding of the collapse of the mound and extensive hydrothermal simmering

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15:07-09, 15:16-18 CAM2The finding of barnacle-like organism at the surrounding of the mound collapse.

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Dive#776 Observor: Takko Nakagawa (JAMSTEC)

Time Position Depth Event Latitude Longtitude

10:21 -190 420 1000 NISKIN (red) 11:23 -170 370 3010 Landing (1.7_C) 13:46 -70 580 2936 WHATS (1,2)130_C

Bag water 14:40 -55 621 2935 Push core (W&B), Rocks 15:13 -44 620 2926 Sampling tube worm 15:51 -90 500 2069 Left bottom

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Date: 27 August , 2003 Site Name: TOTO Caldera Nakayama Field Landing: 11:15; 12°42.6955'N, 143°32.3190'E, 2972m Leaving: 16:06; 12°42.7736'N, 143°32.3455’E, 2934m Observer: Tatsunori Nakagawa (JAMSTEC) Pilot: T. Yoshiume, Co-Pilot: Y. Ono

Objectives: Two major objectives are underlying on this dive 776: 1) Recovery of ISCS and HOMER in the Nakayama Field in the TOTO caldera 2) sampling hydrothermal fluids from the white smoker site.

Dive Summary: We landed at approximately 100m from a top of the mound in the Nakayama Field. After sampling of sea anemone, we ran to the #72 HOMER. We found the #72 HOMER, #1 ISCS, and #71 marker. Then, we retrieved the #1 ISCS and #72 HOMER. We ran to the #71 marker at sulfur chimney site. We found the #2 ISCS. Then, we retrieved the #2 ISCS. We ran to south in order to collect fluids from white smoker site (12°42.7700'N, 143°32.3435'E, 2936m). After observation of the white smoker discovered during yesterday dive, we ran to find another white smoker. Finally, we went back to the same white smoker site. Several white smokers were observed at the white smoker site. After disintegration of the white smoker hole, three WHATS water samples (#1, #2, and #3) were obtained from the fluids at the site (12°42.7736'N, 143°32.3455'E, 2934m). The temperatures of the fluids were max. 70 ˚C and an average of 55 ˚C, max. 69˚C and an average of 55˚C, and max. 145˚C and an average of 120˚C, respectively. Niskin water was obtained before leaving form the bottom. This was the last mission of this dive.

Keywords: White smoker, Volcanic arc, hydrothermal simmering

Payloads: 1) WHATS with a temperature probe for fluid sampling

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2) Bag pomp sampler 3) Sample box x2 4) MBARI core sampler 35cm x2 (MY; Yellow, MG, green) 5) Niskin bottle x2 6) Marker x3

Location of Events: Time Position Depth Event 11:15 12˚42.6955'N, 143˚32.3190'E, 2972m Landing (t = 1.7˚C)

Sampling sea anemone and rock 11:33 12˚42.7714'N, 143˚32.3300'E, 2924m Found KAIKO marker 12:02 12˚42.8007'N, 143˚32.3411'E, 2922m Retrieved ISCS #1 12:19 12˚42.7980'N, 143˚32.3363'E, 2918m Retrieved #27 Mini xponder 13:30 12˚42.7233'N, 143˚32.3262'E, 2945m Retrieved ISCS #2 16:06 12˚42.7736'N, 143˚32.3455'E, 2934m WHATS 1, 2, and 3

(#1, max. 70 ˚C; average. 55 ˚C) (#2, max. 69 ˚C; average. 55 ˚C) (#3, max. 145 ˚C; average. 120

˚C) NISKIN (white and red) Leaving the bottom

Video Digest: No.2 CAM 15:14:45 White smoker site occurred.

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Dive#776 Observor: Takko Nakagawa (JAMSTEC)

Time Position Depth Event Latitude Longtitude

9:55 Vent open 11:15 -180 580 2972 Found bottom, 1.7° C 11:18 3 Seaanemone sampling 11:31 -75 591 2927m Passed white smoker site 11:34 2922m Found KAIKO marker 11:38 2918m Found marker #72 and homer 11:42 2 610 2919m 11:45 5 612 2919m Recover STR-ISCS #2 12:01 -5 607 2887m Finish of recovery 12:18 -5 615 2923m Recover homer 13:30 -141 582 2945m Recover STR-ISCS #1 13:48 -100 590 14:03 -70 600 14:06 -72 604 2836m Found white smoker 14:25 -50 660 2944m 15:12 -63 595 2928m Found ballast of Dive #772 15:19 -60 600 2934m Landed at white smoker site 15:30 Measuring temp. ? 15:40 Start WHATS sampling (70° C)

Finish WHATs sampling (2bottles) 15:49 Start bag-water sampling (69° C) 15:59 Start WHATS sampling (145° C) 16:03 Finish WHATS sampling (3) and

Cancel (4) 16:05 Niskin sampling 16:06 -40 630 Leave the bottom

10:21 -190 420 1000 NISKIN (red) 11:23 -170 370 3010 Landing (1.7_C) 13:46 -70 580 2936 WHATS (1,2)130_C

Bag water 14:40 -55 621 2935 Push core (W&B), Rocks 15:13 -44 620 2926 Sampling tube worm 15:51 -90 500 2069 Left bottom

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Date: 28 August , 2003 Site Name: South Chamorro Seamount Landing: 11:28; 13°47.0063'N, 146°00.4553'E, 2939m Leaving: 16:00; 13°46.7952N, 146°00.2000’ E, 2929m Observer: Ken Takai (SUGAR Project, JAMSTEC) Pilot: Y. Sakurai, Co-Pilot: M. Yanagitani

Objectives: Two major objectives are underlying on this dive 777: 1) mapping cold seep activities in the South Chamorro Seamount Summit 2) sampling seeping fluids and deploying STR-ISCS in the main seep sites.

Dive Summary: We landed at approximately 250m east from a summit of the South Chamorro Seamount. Just before landing (2 m above), the first Niskin water sample was obtained. The landing point was covered with serpentine mud including many serpentine and peridotite rocks. After landing, we run to the Kaiko #165-1 marker settled in the summit. It was moderate ascend. In the way to the Kaiko #165-1 marker, relatively sediment-rich seafloor were observed. We took two MBARI core at 150 m east from the summit (13°46.9868'N, 146°00.4198'E, 2931m). Beyond this point, we encountered the summit seafloor covered with the vast serpentine mud flow, of which surface was all cemented by solid carbonate. The mud flow had many gaps and several shrimps, galetheid, mussels and calms resided in the bottom of the gaps. In front of one of the gaps, we found Kaiko #165-1 marker (13°46.9358'N, 146°00.2503'E, 2899m). Here, WHATS water sample (4 bottle) from the cold seep and Niskin sample from just above the seep were obtained. The temperature of the simmering water was the same as the ambient seawater (1.5 ˚C). We also took one Calyptogena and two mussels. In addition, we deployed the STR-ISCS (No. 2) in actually inside of the gap, the STR-ISCS (No. 1) in the upper terrace of the gap and the STR-ISCS (No. 3, 60 cm length) in the branched gap. During the deployment of the STR-ISCSs, we broke the cemented carbonate covering the surface of the gap. The exposured inside was dark and looked ANME zone. Thus we collected a bulk of carbonated serpertine rock from the bottom of the gap. This was the last mission of this dive.

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Keywords: Forearc, cold seep, peridotite, serpentine, STR-ISCS

Payloads: 1) WHATS with a temperature probe for fluid sampling 2) Bag pomp sampler 3) Sample box x2 4) MBARI core sampler 35cm x2 and 50cm x2 (MY; Yellow, MG, green) 5) Niskin bottle x2 6) STR-ISCS-1, -2, -3 (60 cm length) 8) Scoop 9) Homer x1 10) Marker x3

Location of Events: Time Position Depth Event 11:28 13˚47.0063'N, 146˚00.4553'E, 2939m Landing on rock floor (t = 1.5˚C)

Niskin No. 1 11:53 13˚46.9879'N, 146˚00.4918'E, 2931m Sampling MBARI core (x2) 15:43 13˚46.9358'N, 146˚00.2503'E, 2899m Found Kaiko marker #165-1

WHATS 1, 2, 3, 4 (1.5 ˚C) Two Mussels A clam STR-ISCS 1, 2, 3 Microbial reef 2 pieces

16:00 13˚46.7952'N, 146˚00.2000'E 2929m Leaving the bottom

Video Digest: 12:59:00-12:59:11 CAM2 cold seep & mussels

13:00:25 –13:00:35 CAM2 cold seep & mussels, clams

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14:46:19-14:46:39 CAM2 microbial reef

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Dive#777Observor: Ken Takai (JAMSTEC)


10:03 Vent open 11:22 Niskin (White) 11:28 11 460 2939 Landing 11:45 -20 400 2938 MBARI (Yellow)7 cm 11:51 -25 400 2938 MBARI (Green) 25 cm 12:47 -110 91 2907 Fouond Kaikoh Marker 12:47 -110 91 2907 Found Clams 13:05 -110 80 2909 WHATS (#1) 13:56 -110 80 2909 WHATS (#2) 12:29 -110 80 2909 Collect Calyptogenax1 & Bathymodiolusx2 14:23 -110 80 2909 Set ISCS-1 & 2 14:51 -110 80 2909 Collecte three rocks 15:13 -110 80 2909 Set ISCS-3 15:26 -110 80 2909 WHATS (#3) 15:36 -110 80 2909 WHATS (#4) 16:00 -180 0 2909 Left bottom

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Date: 02 September, 2003 Site Name: South Chamorro Seamount Landing: 11:26; 13°47.1034'N, 146°00.3646'E, 2925m Leaving: 16:09; 13°47.0039N, 146°00.1490’ E, 2906m Observer: Yohey Suzuki (SUGAR Project, JAMSTEC) Pilot: Iijima, Co-Pilot: Ohno

Objectives: Two major objectives are underlying on this dive 777: 1) mapping cold seep activities in the South Chamorro Seamount Summit 2) sampling seeping fluids and deploying STR-ISCS in the main seep sites.

Dive Summary: We landed at approximately 250m north from a summit of the South Chamorro Seamount. The landing point was covered with serpentine mud including many serpentine and peridotite rocks. After landing, we headed to the Shinkai #351 markers placed on the slope of the seamount. On the way to the markers, we found several dead colonies of Bathymodiolus in a hole on the slope. We placed #74 marker and headed again to #351 makers and found the 351 Marker A with an orange ball. In contrast to the 351 dive, most of Bathymodiolu colonies were dead, and we found only a white gastropod active at the site and collected the snail by using a manipulator. It should be noted that the south of the Bathymodiolu colony site, flat fine sediment floor was established elongating the southwest direction. The #75 marker was placed on the flat sediment site. We collected sediment using a core sampler and obtained about a 10 cm core. As we judged that the site is not active any more, we headed to ODP 1200D site. Against the intention, we encountered the ODP 1200C cork. As our dive time was running out and we were unable to find active cold seeping as indicated by alive massive Bathymodiolu colonies, we returned to the #75 marker and collected two WHATS bottles from dead Bathymodiolu colonies. During sampling with WHATS, we found alive Bathymodiolu colonies nearby the Shinkai vehicle, we collected the next two WHATS samples from the alive Bathymodiolu colonies. After collecting several individuals of Bathymodiolu, we collected two MBARI samples from where the active Bathymodiolu was colonized. We collected a carbonate crust and two serpentine rocks

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from this site. This was the last mission of the dive. Keywords: cold seep, mussel, gastropod, STR-ISCS

Payloads: 1) WHATS with a temperature probe for fluid sampling 2) Bag pomp sampler 3) Sample box x2 4) MBARI core sampler 35cm x2 and 50cm x2 (MY; Yellow, MG, green) 5) Niskin bottle x2 6) STR-ISCS-5 8) Scoop 9) Homer x1 10) Marker x3

Location of Events: Time Position Depth Event 11:26 13˚47.1034'N, 146˚00.3646'E, 2925m Landing on rock floor (t = 1.5˚C) 12:03 13˚46.0506'N, 146˚00.2137'E, 2906m Placing #74 marker 13:18 13˚46.0025'N, 146˚00.1848'E, 2906m Found #351 marker

A snail A sediment core Placing #75 marker

13:47 13˚46.0638'N, 146˚00.1849'E 2921m Found ODP1200C cork 16:00 13˚46.0025'N, 146˚00.1848'E, 2906m WHATS (4),

Bathymodiol (4), MBARI (2) Niskin (2) Rocks (2) Carbonate crust (1)

Video Digest: 11:53:20-11:57:20 CAM2 dead mussels (#74 marker)

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12:45:50-12:49:30 CAM2#351 marker and flat floor (#75 marker site)13:08:30-13:09:30 CAM2larger dead mussel colonies (nearby #75 marker)

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,

S h in k a i 6 5 0 0 # 7 7 8 d iv e V id e o L o g a t t h e c o n t r o l r o o m 2 S e p 2 0 0 3 , S o u t h C h a m o r r o S e a m o u n t S c ie n t is t : Y. S u z u k i, Pilo t : K . I i j im a , C o - p ilo t : Y. O h n o

S t a r t Tim e D e p t h S . H C . H

C a m e N o . D e s c r ip t io n

1 1 : 1 8 : 1 7 2 9 2 2 ? ? 2 l ig h t - g r a y m u d a n d c o n g o lo m e r a t e , 1 1 : 2 3 : 1 7 2 9 2 4 2 2 5 ? 2 la r g e b lo c k c o n g lo m e r a t e , a lm o s t s t o p , 1 1 : 2 4 : 3 7 2 9 2 5 2 2 5 ? 2 la n d in g , 1 1 : 2 9 : 1 7 2 9 2 5 1 8 9 ? 2 s t a r t t o m o v e t o 2 1 0 ° 1 1 : 3 1 : 4 7 2 9 2 8 2 1 6 ? 2 Pa s s o v e r s m a ll d e p r e s s io n , s e a f lo o r c o m p o s e d o f m u d a n d c o n g lo m e r a t e 1 1 : 3 6 : 4 2 2 9 1 3 2 0 9 ? 2 s t i l l m o v e , m u d a n d c o n g lo m e r a t e ( m u d s u p p o r t e d ) 1 1 : 3 8 : 4 0 2 9 8 6 2 1 1 ? 2 X= 7 0 , Y= 2 1 0 1 1 : 4 1 : 2 0 2 9 8 6 2 7 0 ? 2 t a lu s d e p o s it s ? C o m g lo m e r a t e s u p p o r t e d m u d 1 1 : 4 5 : 4 0 2 9 8 3 2 7 1 ? 2 f la t s e a f lo o r ? C o n g lo m e r a t e s u p p o r t e d m u d , 1 1 : 4 9 ; 5 0 2 9 8 2 2 7 0 ? 2 s e r p e n t in e m u d a n d p e r id o t it e b lo c k s 1 1 : 5 3 : 2 0 2 9 8 7 2 5 0 ? 2 f in d t h e s h e ll 1 1 : 5 3 : 0 0 2 9 1 2 1 5 9 ? 2 X= 1 0 0 , Y= 3 0 1 1 : 5 5 : 2 0 2 9 1 2 1 5 2 ? 2 s h e ll ( m u s s e ls ) 1 1 : 5 7 : 2 0 2 9 1 2 1 7 7 ? 2 m a n y s h e ll ( m u s s e ls ) 1 2 : 0 3 : 5 0 2 9 1 2 1 7 8 ? 2 N O . 7 4 m a r k e r s e t u p 1 2 : 0 5 : 5 0 2 9 8 8 1 6 2 ? 2 s e r p e n t in e m u d a n d p e r id o t it e 1 2 : 1 3 : 4 0 2 9 8 1 1 5 9 ? 2 X= 6 0 , Y= 1 2 0 , c o n t in u e d t h e s e r p e n t in e m u d a n d p e r id o t it e 1 2 : 1 9 : 4 0 2 9 8 2 3 5 8 ? 2 X= 8 0 , Y= 1 6 0 , c o n t in u e d t h e s e r p e n t in e m u d a n d p e r id o t it e 1 2 : 2 6 : 5 0 2 9 8 4 2 8 5 ? 2 X= 1 3 0 , Y= 1 5 0 1 2 : 2 8 : 4 0 2 9 8 5 2 7 1 ? 2 la r g e b lo c k c o n g lo m e r a t e , 1 2 : 3 0 : 4 5 2 9 8 5 2 1 1 ? 2 X= 1 3 0 , Y= 1 2 0 , f la t s u r f a c e 1 2 : 3 2 : 3 1 2 9 8 3 2 1 2 ? 2 S m a ll f is s u r e ( d e p r e s s io n ? ) w a s o b s e r v e d o n t h e f lo o r 1 2 : 3 4 : 3 1 2 9 8 4 2 1 1 ? 2 X= 7 0 , Y= 1 0 0 1 2 : 3 8 : 0 0 2 9 8 4 2 6 9 ? 2 X= - 4 0 , Y= 5 0 1 2 : 4 2 : 1 2 2 9 8 3 2 6 7 ? 2 la n d in g 1 2 : 4 3 : 5 0 2 9 8 5 2 2 6 ? 2 f in d t h e o ld m a r k e r ( N o . ? ) 1 2 : 4 7 : 3 2 2 9 8 5 2 2 8 ? 2 m a n y s h e ll ( m u s s e ls ) ? 1 2 : 4 9 : 3 2 2 9 8 2 2 1 4 ? 2 f la t f lo o r 1 2 : 5 0 : 4 0 2 9 8 5 2 3 4 ? 2 la r g e b lo c k c o n g lo m e r a t e , 1 2 : 5 3 : 1 2 2 9 8 5 2 3 4 ? 2 p u s h c o r e ( r e d ) 1 2 : 5 7 : 0 0 ? 2 r e t u r n e d t h e c o r e ( r e d ) r e c o v e r e d 1 2 . 5 8 : 1 0 2 8 9 4 ? 2 N O ? M a k e r s e t 1 2 : 5 8 : 4 0 2 9 8 4 ? 2 X= 0 , Y= - 3 0 1 3 : 0 6 : 4 3 2 9 8 4 2 2 3 ? 2 la r g e b lo c k c o n g lo m e r a t e w it h in s e r p e n t it e m u d 1 3 : 0 9 : 2 0 2 9 8 4 2 2 3 ? 2 f in d t h e s h e ll 1 3 : 1 1 : 3 0 2 9 8 5 2 3 6 ? 2 s h e ll c o lo n y ( m u s s le ) 1 3 : 1 9 : 2 0 2 9 8 5 2 4 4 ? 2 c o lle c t t h e g a s t r o p o d a , 1 3 : 2 4 : 1 4 2 9 8 5 2 4 5 ? 2 e n d s a m p lin g , s t a r t t o m o v e t o 3 0 0 ° 1 3 : 3 2 : 1 4 2 9 2 2 3 0 0 ? 2 m u d a n d s e r p e n t in e c o n g lo m e r a t e , n o - c o m m u n it y 1 3 : 3 4 : 2 8 2 9 2 8 2 9 4 ? 2 X= 1 0 0 , Y= - 1 2 0 ( m u d a n d s e r p e n t in e c o n g lo m e r a t e , n o - c o m m u n it y ) 1 3 : 3 7 : 4 5 2 9 2 5 2 4 0 ? 2 Z o o m u p o f s e r p e n t in e r o c k s 1 3 : 4 1 : 2 5 2 9 2 5 8 2 ? 2 X= 9 0 , Y= - 1 9 0 1 3 : 4 5 : 2 5 2 9 2 9 3 8 ? 2 c a r b o n a t e c r u s t ? 1 3 : 4 6 : 2 5 2 9 2 3 5 8 ? 2 O D P 1 2 0 0 C , r e - e n t r y c o n e , X= 1 2 0 , Y= - 7 0 1 3 : 4 7 : 1 5 2 9 2 8 9 4 ? 2 X= 1 1 0 , Y= - 1 5 0 1 3 : 5 1 : 5 2 2 9 1 2 1 4 7 ? 2 f in d Yo k o s u k a M a k e r # ? 1 3 : 5 2 : ? ? 2 9 8 5 1 2 3 ? 2 X= 9 0 , Y= 3 0 1 3 : 5 5 : 4 6 2 9 8 4 2 1 1 ? 2 s e r p e n t in e r o k c s ( c o n g lo m e r a t e ) c o v e r e d w it h t h in m u d 1 3 : 5 7 : 3 2 2 9 8 3 2 1 0 ? 2 X= 5 0 , Y= 3 0 1 4 : 0 0 : 2 6 2 9 8 3 2 1 1 ? 2 X= - 3 0 , Y= - 1 0 1 4 : 0 3 : 1 5 2 9 8 6 2 7 2 ? 2 s e r p e n t in e r o k c s ( c o n g lo m e r a t e ) c o v e r e d w it h t h in m u d , X= - 5 0 , Y= - 7 0 1 4 : 0 8 : 2 7 2 9 2 6 3 2 9 ? 2 X= 4 0 , Y= - 2 0 1 4 : 1 1 : 2 7 2 9 2 6 3 0 1 ? 2 t u b e w o r m ? 1 4 : 1 2 : 4 7 2 9 2 8 3 0 1 ? 2 X= 1 0 0 , Y= - 1 9 0 , t u b e w o r m - lik e o r g a n is m w a s o b s e r v e d 1 4 : 1 7 : 2 7 2 9 8 3 9 1 ? 2 X= 1 4 0 , Y= - 2 3 0 1 4 : 2 1 : 1 8 2 9 8 4 1 4 8 ? 2 X= 1 3 0 , Y= - 1 3 0 1 4 : 2 5 : 1 8 2 9 8 6 1 8 2 ? 2 X= 7 0 , Y= - 8 0 1 4 : 2 7 : 4 0 2 9 8 2 1 4 9 ? 2 t u b e w o r m ? A d h e r e n c e o n r o c k 1 4 : 2 9 : 4 8 2 9 8 1 1 5 8 ? 2 X= 0 , Y= - 6 0 1 4 : 3 3 : ? ? 2 9 8 8 1 4 6 ? 2 S e r p e n t in e r o c k s ( c o n g lo m e r a t e ) , n o - b io lo g ic a l a c t iv it y 1 4 : 3 7 : ? ? 2 9 8 3 9 8 ? 2 X= 2 0 , Y= - 4 0 1 4 : 4 1 : ? ? 2 9 8 2 2 6 7 ? 2 X= 2 0 , Y= 0 1 4 : 4 4 : ? ? 2 9 8 3 2 0 1 ? 2 f in d in g m a r k e r 1 4 : 4 7 : 1 9 2 9 8 5 2 6 5 ? 2 L a n d in g c lo s e t o A m a r k e r ( # 3 5 1 ) a n d s t a n d - b y u n t il r e d u c e t u r b id it y , m u s 1 4 : 5 2 : 2 9 2 9 8 5 2 7 7 ? 2 M u s s le c o m m u n it y a n d c a r b o n a t e c r u s t s ( ? ) 1 4 : 5 5 : 4 8 2 9 8 5 2 7 7 ? 2 w a t e r s a m p lin g ( g r e e e n t a p e w it h s a m p le r , W H A TS # 1 - # 2 ? ) 1 5 : 0 5 : 1 9 2 9 8 5 2 7 7 ? 2 d if f u s e f lo w w a s o b s e r v d a t s c u p p e r o f w a t e r s a m p le r 1 5 : 1 7 : 4 1 2 9 8 5 2 7 5 ? 2 s h e ll c o lo n y ( m u s s e ls ) a n d s e r p e n t in e b lo c k 1 5 : 1 9 : 2 1 2 9 8 5 2 7 5 ? 2 w a t e r s a m p lin g : W H A TS N O . 3 1 5 : 3 0 : 1 0 2 9 8 5 2 7 1 ? 2 f in d t h e g a la t h e id a e ? 1 5 : 3 2 : 3 0 2 9 8 5 2 7 2 ? 2 w a t e r s a m p lin g : W H A TS N O . 4 1 5 : 3 7 : 1 5 2 9 8 5 2 7 9 ? 2 f in is h t h e w a t e r s a m p lim g . 1 5 : 4 0 : 2 2 2 9 8 5 2 7 9 ? 2 s a m p lin g m u s s e ls ; 2 in c a r b o n a t e m a t r ix 1 5 : 4 5 : 2 2 2 9 8 5 2 7 4 ? 2 m a k e r ( ? ) s e t ( g r e e n ) 1 5 : 4 9 : 3 3 2 9 8 5 2 7 4 ? 2 s a m p lin g m u s s e ls a n d c a r b o n a t e m a t r ix 1 5 : 5 2 : 0 0 2 9 8 5 2 6 2 ? 2 M B A RI ( 3 5 c m ) w h it e 1 5 : 5 5 : 2 1 2 0 9 5 2 6 6 ? 2 I S C S 5 s e t 1 5 : 5 8 : 0 5 2 9 8 5 2 7 1 ? 2 r e c o v a r y o f M B A RI ( w h it e ) 1 5 : 5 9 : 4 0 2 9 8 5 2 6 7 ? 2 w a t e r s a m p lin g ? ( b y n is k in ) 1 6 : 0 3 : 5 3 2 9 8 5 2 7 8 ? 2 s e r p e n t in e m u d s a m p lin g 1 6 : 0 7 : 2 2 2 9 8 5 2 7 3 s a m p lin g 2 r o c k s 1 6 : 0 8 : 2 5 2 9 8 6 le a v e b o t t o m

W H A TS # 1 - # 4 , M B A RI ( w h it e ) , N is k in 2 b o t t le s , 2 r o c k s a n d 1 c a r b o n a t e

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Date: 3 September, 2003 Site Name: South Chamorro Seamount Landing: 11:24; 13°47.1513’N, 146°0.0678’E, 2980m Leaving: 15:56; 13°46.0509’N, 146°.1651’ E, 2925m Observer: Hitoshi Chiba (ISEI, Okayama University) Pilot: Y. Nunbu, Co-Pilot: T. Yoshiume

Objectives: Two major objectives are underlying on this dive 779: 1) sampling of seeping fluids, living organisms and sediments in the South Chamorro Seamount Summit area, and, 2) sampling of various kinds of rocks, serpentine, metamorphic and ultra-mafic rocks and carbonate crusts.

Dive Summary: We landed at approximately 200m northwest of the planed landing point, ODP CORK deployed by Leg 195 in 2001. Landing point was muddy seafloor with pebbles (peridotite rocks). After landing, we run to the CORK. When we found the CORK, we changed the course to the south for searching other ODP drill holes. As we approached to the ODP drilling site, surface of seafloor became covered with thin white-grey serpentine mud, like small amount of snow. As we approached further to the drilling site, white-gray serpentine mud layer became thick. At least three ODP drill holes were observed in this site. Drill holes had small rim of drill cuttings around the hole. One push core and one MBARI core (35 cm type) were sampled slightly off from the mound. After these samplings, we moved to the marker #75 site. We saw Shinkai6500 #351A marker close to the marker #75. We took three MBARI cores (2 x 50cm and 1 x 35cm types) at the center of thick serpentine mud pond. The top of the collected cores was composed of white-gray serpentine, but bottom part was black suggesting sulfate-reducing bacterial activity. Then, we ran to the place good to collect rock samples. The rock collecting site was 50m southward from the marker #75. Here, we took three rock samples. After rock collection, we ran toward the top of the seamount where biological community was found by the #777 dive. We easily reached to the place because of the guidance by the homer beacon deployed by the #777 dive. Here, we found that the homer, ISCS, and the Kaiko #165-1 marker were very closely seated.

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Many organisms were collected by scoop, which include one snail, two Calyptogena, and many mussels. They live at the edge of the channel on the seafloor. Collected live Calyptogena and mussels are very small in size. Lots of dead mussel shells were also found in the channels, suggesting the biological community is waning at present. The bottom and walls of the channel were composed of hard carbonate. Several carbonate crusts of the channel were sampled. We searched dense biological community around there in order to sample cold seep, but failed. After the decision not to sample fluid here, we went back to the ODP holes upon request from the mother ship. We took a push core at the rim of drill cuttings and collected two rock samples around the hole and left bottom.

Keywords: Mariana, Fore-arc seamount, cold seep, peridotite, serpentine, carbonate, organisms

Payloads: 1) WHATS with a temperature probe for fluid sampling (not used)2) Bag pomp sampler (not used)3) Sample box x24) MBARI core sampler 35cm x2 and 50cm x25) Niskin bottle x2 (not used)6) Scoop7) Marker x3 (only #76 marker was used)

Location of Events: Time Position Depth Event 11:24 13˚47.1513'N, 146˚0.0678'E, 2980m Landing on muddy seafloor with

pebbles 12:14 13˚47.0419'N, 146˚0.1651'E, 2926m Sampling Push core (x1) and

MBARI core (35cm x 1) at ODP hole

12:45 13˚46.9967'N, 146˚0.1851'E, 2905m Sampling MBARI cores (50cm x 2 & 35cm x1) at #75 marker

13:05 13˚46.9710'N, 146˚0.1851'E, 2903m Sampling rocks (x3) 14:35 13˚46.9310'N, 146˚0.2476'E, 2929m Sampling organisms (snail,

Calyptogena, and mussels), and

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carbonate crust (x5) 15:56 13˚40509'N, 146˚0.1651'E, 2925m Left bottom after sampling of push

core (x 1) and rocks (x2)

Video Digest: 11:45:35-11:46:30 CAM2 ODP CORK 1200C deployed by Leg 125

15:17:28-15:17:50 CAM2 Base part of ODP CORK

11:57:40-11:59:20 CAM2 ODP drill hole 1200D

15:38:48-15:39:30 CAM2 Push core at the rim composed of drill cuttings

12:30:58-12:32:10 CAM2 MBARI sampling at #75 marker site

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Shinkai 6500 #779 dive Video Log at the control room 3 Sep, 2003 Scientist: H. Chiba, Pilot: Y. Nanbu, Co-pilot: T.Yoshiume

Time Depth S.H Event Mark (Stop No.) Description

9:55 0 - Vent Open 11:24 2980 Landing, X=-280, Y=-240 11:33 2950 161 Serpentinite rocks (conglomerate) thinly covered with mud 11:36 2938 161 X=140, Y=-190 11:43 2926 58 flat plane covered with mud 11:45 2927 64 find ODP 1200C Cone, X=100, Y=-80 11:49 2926 165 flat plane covered with mud 11:52 2925 249 find ODP Dril l hole (1200D) 11:55 2925 209 Dril l hole (1200D) picture was taken by shinkai 12:02 2925 183 Dril l cuttings and peridotite around ODP Hole 12:06 2926 214 push core sampling (red) 12:10 2926 215 Recovery push core (red) 12:12 2926 217 MBARI(White, 35cm) Core 12'15 2926 215 X=80, Y=-60 12:18 2925 215 Ripple mark? 12:19 2915 162 start to move to 160° 12:20 2915 160 block in matrix (serpentin mud and peridotite) 12:25 2904 158 find the marker #75, stop at near 75 marker 12:28 2905 196 MBARI (black 50cm) 12:34 2905 213 try to MBARI (blue, 50cm) sampling 12:38 2905 213 try to MBARI (green, 35cm) sampling 12:45 2905 215 report of push core and MBARI sampling, X=0, Y=-30 12:50 2983 170 Start to move (S.H=165° ) 12:52 2983 190 serpentine rocks covered with thin mud 12:53 2983 192 Stop for rock sampling, X=-60, Y=-30 13:05 2903 sampling report from Shinkai (3 rocks sampling), start to move 13:07 2903 230 talus deposits (peridotite) ? 13:10 2908 122 carbonate crust together with conglomerate (serpentine?) 13:13 2897 125 start to move, carbonate crust and fragment 13:15 2897 carbonate crust covered with mud 13:17 2897 finding ISCS and homer 13:24 2899 205 small mussels colony was observed in fissure or depression of carbonate crust 13:28 2899 218 stop for sampling 13:46 2899 bivalve sampling by scoop type sampler and stored in ahead right side sample box in the middle part 14:10 2908 245 finding gastropoda and sampling in closed box center 14:33 2908 288 sampling report from SHINKAI (5 rocks and a few shells) 14:45 2899 285 start to move for finding musseles colony site, and start to WHATS at mussels colony site 14:53 2898 flat plane covered with mud and carbonate crust(?) 14:59 2898 298 report from Shinkai (Scince large mussels colony was not found, start to move for dril l hole), X=-130,15:05 2897 start to move (Heading 350° ) 15:06 2898 X=10, Y=-20 15:06 X=90, Y=-30 15:17 2928 303 arraival at ODP 1200C cone 15:20 Shinkai located at X=-100m, Y=-100m to object point (dril l hole) 15:26 2926 158 arraival at ODP dril l hole 15:27 2926 119 stop at ODP dril l hole and try to push coring 15:37 2925 start to push core (yellow)

Y

15:55 2925 35 Ripple mark was observed on flat surface 15:46 2925 report from SHINKAI (push core_yellow and deployment 76 marker), try to collect rock samples

15:57 2925 report from SHINKAI (2 rocks sample) and leaving

MBARI (50cmX2, 35cmX2), Push Core (red, yellow), 10rocks, biological sample (mussels)

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Date: 4 September , 2003 Site Name: South Chamorro Seamount Landing: 11:21; 13°46.9584'N, 146°00.2513'E, 2899m Leaving: 16:00; 13°47.0325N, 146°00.2236’ E, 2902m Observer: Ken Takai (SUGAR Project, JAMSTEC) Pilot: Y. Sakurai, Co-Pilot: M. Yanagitani

Objectives: Two major objectives are underlying on this dive 780: 1) retrieving STR-ISCS and ISCS deployed in the animal communities in the summit and 6K351 site and 2) sampling subcores and indigenous water from ODP1200E borehole.

Dive Summary: We landed at approximately center of summit of the South Chamorro Seamount. To retrieve three STR-ISCS deployed in the crack of the Kaiko #165-1 marker, we went to south. Then, three STR-ISCS were successfully recovered. After recovery, we went to 6K351 site or Marker#75 site. First we run to west until X-0 and then we headed to north. Just 10 m before the #75 marker, I found a clear non-treated borehole in the west edge of the terrace, in which #75 marker and 351-A and –B markers. After recovery of the ISCS close to 351-A marker, we went to landing adjacent one of the ODP1200 boreholes. The borehole was very deep and had relatively small mound around hole than the holes discovered in DIVE#779. 10 m away north from the hole, another borehole was found. From the borehole, the bag water sample (10L) and WHATS (-1, -2, -3, -4) samples were collected. Then, 50 cm MBARI were tried to take the inclined subcores from the borehole. The microbiology MBARI was from the east wall (terrace side) and geochemistry MBARI was from the west wall (valley side). In addition, two 35 cm MBARI were retrieved in the mound around the hole. Finishing the sampling at around the borehole, we returned to the #75 marker and did the animal sampling. Finally, we went to the northeast from the #75 marker and left the bottom.

Keywords: ODP borehole, cold seep, peridotite, serpentine, STR-ISCS

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Payloads: 1) WHATS with a temperature probe for fluid sampling 2) Bag pomp sampler 3) Sample box x2 4) MBARI core sampler 35cm x2 and 50cm x2 (MY; Yellow, MG, green) 5) Push corer x2 6) Niskin bottle x2 7) Scoop 8) Marker x2

Location of Events:

Time Position Depth Event 11:21 13˚46.9584'N, 146˚00.2513'E, 2899m Landing on rock floor (t = 1.5˚C) 12:01 13˚46.9305'N, 146˚00.2428'E, 2899m Recovery of STR-ISCS 1, 2, 3 12:38 13˚46.9945'N, 146˚00.1736'E, 2906m Recovery of ISCS 5

Carbonate crust push core 15:01 13˚47.0029'N, 146˚00.1702'E, 2906m WHATS 1, 2, 3, 4 (1.5 ˚C)

50 cm MBARI x2 35 cm MBARI x2

15:52 13˚47.0083'N, 146˚00.1757'E 2906m Sampling animals 16:00 13˚47.0325'N, 146˚00.2236'E 2902m Leaving bottom

Video Digest: 12:58:55-13:00:25 CAM2 ODP1200A, E or F borehole

14:23:20 –14:25:20 CAM2 MBARI subcoring

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Shinkai 6500 #780 dive Video Log at the control room 4 Sep, 2003 South Chamorro Seamount Scientist: K. Takai, Pilot: T . Sakurai, Co-pilot: M.Yanagitani

T ime Depth S.H Description 9:11 - Swimer stand by 9:58 - Vent open

11:16 Report form Shinkai (trim good) 11:21 2899 Landing, Conglomerate, WaterT emp.=1.6° C, X=-80 Y=100 11:23 2898 Start to move to HOMER site 11:27 2898 Arraival and stop at ISCS and HOMER site 11:41 2899 Recovery of HOMER? (black) 11:45 2899 Report from Shinkai (recovery of HOMER & ISCS) 11:45 2899 193 Galatheidae was observed 11:50 2900 175 Fissure was observed on surface, ISCS with red cable located in this fissure. Recovery of this ISCS 12:02 2899 148 Report from Shinkai )‹ (recovery of two ISCS, move head 7012:06 2898 271 Move head 270° 12:09 2906 271 X=-150, Y=0 12:15 2903 15 X=-110, Y=-40 12:27 2906 87 Recovery of ISCS, green in color

12:40 2906 92 Report from Shinkai (reporrecovery of ISCS, green in color, obsarbation arounding this area)

12:54 2902 175 Report from Shinkai (push core, yellow), X=-110, Y=-40, Start to move to drill hole

13:25 2907 99 Report from Shinkai (1 rock sampling near drill hole)

12:31 2906 88 Finding carbonate

12:46 2905 163 Serpentine mud, peridotite and carbonate?

12:59 2901 251 Arraival at drill hole site 13:16 2907 97 Landing close to drill hole (black color mud is deposited around drill hole) and try to MBARI, WHATS

13:28 2907 87 Zoom up #351 marker 13:29 2907 99 Start to collect water sample (20lit .) and canceled this sampling 13:34 2907 99 Re-try to collect water sample (20lit .) from the inside of drill hole 13:43 2907 97 Report from Shinkai (finish of 20liter water sampling)

13:55 2908 97 Report from Shinkai (finish of WHATS #1 and start of next WHATS) 14:03 2908 97 Report from Shinkai (finish of WHATS #2 and start of next WHATS)

14:11 2908 98 Report from Shinkai (finish of WHATS #3 and start of next WHATS)

14:23 2908 98 Report from Shinkai (finish of MBARI #4 and start to collect mud sample by MBARI long)

13:45 2908 96 Start to collect water sample (WHATS) from the inside of drill hole

14:08 2908 97 Zoom up swimming fish

14:21 2908 98 Finish of MBARI #4

14:24 2908 98 Start of MBARI (green, 50cm) and sampling was carried out inside of drill hole 14:32 2908 98 Recovery of MBARI (green, 50cm) 14:33 2908 97 Start of MBARI (white, 50cm) and sampling was carried out inside of drill hole 14:35 2908 96 Recovery of MBARI (white, 50cm) 14:38 2908 96 Start of MBARI (yellow, 35cm) and sampling was carried out the top of drill cuttings 14:40 2908 96 Recovery of MBARI (yellow, 35cm) 14:42 2908 96 Start of MBARI (black, 35cm) and sampling was carried outand sampling was carried out the top of drill cuttings 14:44 2908 97 Recovery of MBARI (black, 35cm)

Sampling report from Shinkai (MBARI 50cm x2, 35cm x2 & WHATS #1-#4), and try to collect mud sample from the drill 14:47 2908 98 cuttings by metal scoop type sampler 15:01 2907 96 Reported from Shinkai (finish of mud sample collecting) 15:04 2907 96 Reported from Shinkai (return to marker 75 and will start biological sampling) 15:23 2906 119 Finding mussels colony 15:28 2906 122 Sampling (mussels with mud) 15:53 2904 125 Report from Shinkai (start to move to 40° ) 15:54 2903 35 #351 marker 15:57 2903 X=20, Y=-20 15:58 2903 Leave bottom, X=50 Y=30

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Date: 7 September, 2003 Site Name: Bluemoon Seamount, Mariana Forearc Landing: 11:42; 15°43.9270'N, 147°11.2704'E, 3683m Leaving: 15:38; 15°43.7004’N, 147°11.9945’E, 3583m Observer: Kantaro Fujioka (ORDept, GODI) Pilot: Y. Sasaki, Co-Pilot: Y. Ohno

Objectives: Two major objectives are underlying on this dive 781: 1) geologic mapping of the Bluemoon Seamount Summit 2) sampling rocks, sediments, fluids and animals. These results will be combined with those of #782, 783, 784, 785 and 786 of the other serpentine seamounts.

Dive Summary: We landed at the pebbly mud slope of the canyon-like structure taking a Niskin bottle sample above the seafloor before landing. At the landing point at water depth of 3683 m we took one push core sample of the surface sediments that covers canyon formation and represent a notable ripple mark which shows a strong current ordinary go through up and down direction of the seamount. We took a submersible course to 120° down to the bottom of the canyon at water depth of 3695m where thick sediments cover the canyon. As the submersible climb up the canyon slab-like strata that is composed of pelagic sediments covered with thick manganese oxide were seen everywhere showing gentle inclination to the up dip direction. The strata consist of soft sediments, manganese cover, pelagic sediments in the descending order and no serpentine mud strata were observed during this dive. Instead the lithology we observed during this dive was all the same that we observed at the stop 2. This means that the serpentine mud flow event if occurred ceased before the pelagic sediments deposited (we need to check the age of the deposition of the pelagic sediments as well as the age of the manganese oxide). A huge outcrop of rectangular rock covered with manganese exposed on the seafloor. This outcrop is stratified sequence of semi-consolidated pelagic mud overlain by manganese crust and thin present sediments. Even the summit of Bluemoon Seamount is covered with thick calcareous mud and partly exposed old strata consisting of the

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semi-consolidated mud. During this dive we saw pelagic mud, manganese and present mud along the track line.

As the concluding remarks it will be said that the serpentine mud flow activity if occurred ceased before the deposition of the semi-consolidated pelagic mud, that is about several million years ago. We did not find any active seepage nor carbonate chimneys at all. We did just only one line survey at this seamount. The eastern slope of the Bluemoon Seamount is needed urgently.

During this dive we collected 17 rocks 2 push cores 2 MBARI cores 1 Niskin bottle sample and 398 still photos of the external camera, 2 No. 1video and 2 No. 2 video records and continuous record of StrataBox and three-component magnetometer data were obtained along the ship’ tracks. During this dive, most of the primary objectives were met. However, we still need survey and sampling from the eastern slope of the Bluemoon Seamount where a huge collapse structure is seen un the bathymetric map. . Keywords: Mariana Forearc, serpentine seamount, collapse, manganese coating, pelagioc sediments

Payloads: (1) WHATS gas sampler with thermometer orifice (2) Sample boxes, right & left (3) Push corers (3 if possible).. (4) MBARI core sampler (50cm long x 2, 35cm long x 2) (5) Niskin water sampler (200 ml x 2) (6) Scoop. (7) 3 JAMSTEC markers (8) StrataBox. (9) Three-component magnetometer

Location of Events: Time Position Depth Event 11:39 15°43.9270'N, 147°11.2704'E, 3682m Landing on rock floor

Niskin No. 1 11:42 15°43.9270’N, 147°11.2704’ E, 3683m Sampling push core and 3 rocks 12:44 15°43.8291N, 147°11.4350’ E, 3678m Sampling 3 rocks 13:38 15°43.7958’N, 147°11.4876’ E, 3635m Sampling 3 rocks

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14:19 15°43.7723’N, 147°11.5178’ E, 3617m Sampling 3 rocks 14:47 15°43.7611N, 147°11.6216’ E, 3601m Sampling 3 rocks 15:38 15°43.7004N, 147°11.9945’ E, 3583m Left the bottom

Video Digest: 11:55:04-11:55:34 30 CAM2 Platy manganese coating mudstone and brown semi-consolidated pelagic mud

11:58:20-11:58:40 20 CAM2 Platy manganese coating mudstone and brown semi-consolidated pelagic mud

12:14:07-12:14:46 39 CAM2 Deformed platy manganese coating mudstone and brown semi-consolidated pelagic mud

12:16:51-12:17:11 20 CAM2 Deformed platy manganese coating mudstone and brown semi-consolidated pelagic mud

13:23:40 –13:24:28 48 CAM2 Stratified sequence of present pelagic mud, manganese crust and brown semi-consolidated mudstone.

13:51:37-13:52:37 60 CAM2 Huge outcrop of manganese-coated pelagic mud with joints and present pelagic mud with ripple marks.

14:02:01-14:02:20 19 CAM2 14:04:18-14:04:32 14 CAM2 Sand balls make a line under a huge block

14:42:50-14:43:28 38 CAM2 Stratified huge outcrop of pelagic mudstone

15:25:54-15:26:06 12 CAM2

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MBARI core sampling at the surface of the present pelagic mud Total 300

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Shinkai 6500 #781 dive Video Log at the control room 7 Sep, 2003 Blue Moon Seamount Scientist: K. Fujioka, Pilot: Y. Sasaki, Co-pilot: Y.Ohno

T ime Depth S.H Description 9:58 - Vent open

11:37 3,683 255 Small rock fragments ware scattered on mud 11:39 3682 237 Water Sampling (Niskin), (X=420, Y=-767) 11:41 3683 343 Zoom up seafloor (mud & small rock fragments) 11:42 3683 336 Landing (X=420, Y=-770), Water Temp.=1.5° C 11:49 3683 325 3Rocks sampling, push coring (red) 12:03 3683 329 Report from Shinkai (This stop location was defined sa "Stop1") 12:08 3684 108 X=450, Y=-750 12:12 3690 121 Outcrop of layered rock (?) covered with mud 12:13 3693 121 X=375, Y=-645 12:15 3696 121 Flat surface covered with mud 12:17 3695 121 Small rock fragments were scattered on mud (X=280, Y=-540) 12:21 3680 115 Outcrop of rocks, arrival at base of clif (X=245, Y=-464) 12:22 3680 77 Stop for collecte rock sample 12:44 3677 77 Sampling of 3 rocks

12:57 3676 104 Sampling of surface mud including small rock fragments by metal sccop sampler, Report from Shinkai (This stop location was defined sa "Stop2"), X=-250, Y=-464

13:03 3676 87 Start to move to 120° , large blocky reocks were observed 13:05 3670 119 Mud surface (X=253, Y=-432) 13:09 3647 117 Conglomerate covered with mud (X=197, Y=397) 13:11 3638 120 Outcrop, stop for collect samples (X=170, Y=-370) 13:38 3635 82 Sampling of 3 rocks and This stop location was defined sa "Stop3" 13:41 3633 120 Start to move to 120° 13:47 3615 53 Stop for observation of outcrop (X=130, Y=-330) 14:02 3617 65 Zoom up quail's egg like rocks 14:16 3618 84 Large rock boby was observed

14:18 3617 84 Report from Shinkai (3 rocks sampling, and this stop location was defined sa

‹"Stop4"), and start to move to 90 14:21 3617 91 mud covered surface (X=131.5, -321) 14:26 3602 91 Layered rocks covered with mud (X=130, Y=-137) 14:31 3602 342 X=110, Y=-137 14:32 3608 18 Stop for sampling 14:35 3601 46 Ripple mark? And huge rock block with seaanemone

14:48 3600 76 Report from Shinkai (3 rocks sampling, and this stop location was defined sa ‹"Stop5", X=110, Y=-140), and start to move to 90

14:59 3598 92 X=80, Y=-90 15:01 3593 91 Mud surface (X=66, Y=18) 15:05 3591 91 X=70, Y=50 15:07 3591 91 Layered rocks covered with mud 15:08 3589 91 Mud surface (X=50, Y=130) 15:12 3588 91 Mud surface (X=30, Y=280) 15:15 3592 91 Mud surface (X=10, Y=410) 15:19 3585 102 Outcrop? 15:20 3583 86 Stop for sampling of coring (X=4, Y=522) 15:23 3584 77 Push coring (red) 15:25 3584 76 MBARI (green) 15:28 3584 75 MBARI (yellow) 15:32 3584 62 Zoom up shrinp 15:37 3583 76 2 rocks sampling and leave bottom (X=0, Y=530)

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Date: 8 September, 2003 Site Name: Celestial Seamount Landing: 11:02 16°32.0566'N, 147°13.2464'E, 1987m Leaving: 16:10; 16°31.3444N, 147°13.0751’ E, 1881m Observer: Kantaro Fujioka (ORDept, GODI) Pilot: T. Yoshiume, Co-Pilot: Y. Nanbu

Objectives: Major objectives are two holds on this dive 782: 1) reconnaissance of the serpentine seamount around the Celestial Seamount summit 2) sampling seeping, rocks, cores and sediments.

Dive Summary: We landed at the down slope of sedimented serpentine mud flow and took 3 rock

samples. On the sediments notable ripple marks and glass sponge stand on the exposed rock are seen. At the steep cliff around the summit we encountered the surface of serpentine mud with strong slickenside on the surface. The direction of the slickenside shows the downward sliding of the overriding sediments and rocks that was an old serpentine mud flow. His means the seamount collapsed at the eastern half at sometime by fault movement or earthquake. A huge octpus swimming and sitting just in front of our submesible and it started to circulate gradually. Then it flied over around our sub and sit down in front of our sub again. We saw it’s eye sometimes closing and opening just like thinking of a philosopher’s meditation. The summital ridge of the seamount is narrow and strong current swing the sub. We saw several serpentine mud outcrop. We collected 5 rocks which are calcarenites and chert. Remains of landing of some reaesearch vessel must be US are seen at the varios locations. Serpentinized peridotite of the seamount include many pyroxene compared with those of S. Chamorro, Conical, Pacman seamounts. Judging from the evidence that the carbonate rocks and silica encrusted rocks confirmed the existence of active seepage at this seamount not so much older time but recently. The existence of chert even on piece make us bother about its origin. One scenario is the recycling of the subducted Jurassic siliceous sediments offscraped and accreted at the wedge mantle then transported by the serpentine mud. We have to consider the scenario

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of collapse of the seamount by the compilation of all the data available. During this dive we collected 20 rocks, 3 push cores, 4 MBARI cores, 2 scoop

samples, 1 Niskin bottle sample and 401still photos of the external camera 2 No. Vide and 2 No. 2 video records and continuous record of StrataBox and three-component magnetometer data were obtained along the ship’ tracks. During this dive, most of the primary objectives were met. However, we still need survey and sampling from the eastern slope of the Celestsial Seamount where a huge collapse structure is seen un the bathymetric map.

Keywords: Mariana Forearc, Serpentine seamount, peridotite, serpentie mud flow, Slickenside

Payloads: (1) WHATS gas sampler with thermometer orifice (2) Sample boxes, right & left (3) Push corers (3 if possible).. (4) MBARI core sampler (50cm long x 2, 35cm long x 2) (5) Niskin water sampler (200 ml x 2) (6) Scoop. (7) 3 JAMSTEC markers (8) StrataBox. (9) Three-component magnetometer (10) HOMER

Location of Events: Time Position Depth Event 11:02 16˚32.0566'N, 147˚13.2464'E, 1987m Landing on rock floor pebbly mud

3 rocks and 1 push core 11:56 16˚31.9130'N, 147˚13.2325'E, 1968m Sampling 6 rocks 12:40 16˚31.8151'N, 147˚13.0901'E, 1954m Sampling 3 rocks, push core

2 Scoop 14:31 16˚31.5949'N, 147˚12.6108'E 1836m Sampling 3 rocks, push core 15:44 16˚31.3755'N, 147˚13.0444'E 1870m Sampling 5 rocks, push core 16:10 16˚31.3444'N, 147˚13.0751'E 1881m Sampling MBARI 4Left the bottom

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Video Digest: 11:01:17-11:01:41 24 CAM2 The boundary between the present mud with ripple marks on the surface and serpentine mud flow deposit

11:19:44-11:19:59 15 CAM2 Fragile glassy sponge root

13:24:56-13:25:44 48 CAM2 Slickenside on the serpentine flow deposit. Note the direction is downward to the east

13:32:09 –13:32:47 38 CAM2 A sharp bottom boundary of the serpentine mud flow

13:57:51-14:00:15 144 CAM2Octpus was swimming down and sitting in front of the sub and go round qt the sameposition looking at our sub

15:27:48-15:28:12 24 CAM2A huge rolling stone forming a remnant hill and sampling these rocks (hard carbonate)

15:45:49-15:45:56 7 CAM2A red shrimp is swimming across our subTotal 300

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Shinkai 6500 #782 dive Video Log at the control room 8 Sep, 2003 Celestial Seamount Scientist: K. Fujioka, Pilot: T . Yoshiume, Co-pilot: Y.Nanbu

T ime Depth S.H Description 9:10 Swimmer stand by

10:00 Vent open 10:53 Report from Shinkai (trim good) 10:59 1986 122 Rounded conglomerate deposits on mud, ripple mark? 11:01 1987 159 Landing (X=840, Y=970), mud surface with conglomerate, stop for sampling

11:10 1987 Report from Shinkai (sampling of 3 rocks and push core (blue), this location is "stop1", ‹X=840, Y=970), start to move to 200

11:23 1982 201 Observation of layered strata 11:26 1971 Depression? (X=780, Y=960) 11:27 1969 201 Sponges were observed 11:29 1969 191 Flat surface covered with mud, change heading to 180° (X=724, Y=937)

11:33 1966 182 Flat surface covered with mud and ripple marks. Sometimes small conglomerates were scattered on mud surface

11:35 1967 178 X=664, Y=-945 11:38 1961 180 T alus deposits? 11:40 1960 149 Stop for rock sampling

11:57 1958 82 ‹move to 200 12:03 1952 230 Block in matrix structure? What is matrix? Pelagic mud or serpentine mud? 12:05 1961 230 X=490, Y=870 12:06 1961 230 Ripple marks? 12:07 1968 250 Move to heading to 250° 12:11 1956 250 Stop for rock sampling 12:16 1956 386 Cancel to rock sampling, start to move to 200° 12:18 1954 329 Stop for rock sampling (X=396, Y=690) 12:28 1954 334 Push core (yellow) 12:32 1954 339 Sampling by scoop

Report from Shinkai (sampling of 6 rocks, this location is "stop2", X=580, Y=950), start to

329 Report from Shinkai‹X=400, Y=700), start to move to 250 12:40 1954 (sampling of 3 rocks, scoop sample and push corethis location is "stop3",

12:45 1949 257 Layered strata covered with mud 12:46 1949 248 X=382, Y=649 12:50 1943 259 Flat plane covered with mud and conglomerates were scattered on surface, X=340, Y=602 12:52 Large blocky rocks with sharp edge was observed 12:59 1928 252 Flat plane composed of blocky rocks, and sponge adhere to rock surface 13:01 1923 251 X=269, Y=512 13:02 1919 252 Flat plane covered with mud 13:06 1913 254 X=216, Y=434, mud and conglomerate 13:08 1908 252 X=210, Y=420 13:13 1901 254 X=170, Y=337 13:15 1893 251 X=150, Y=310 13:18 1891 283 Change heading to 285° (X=144, Y=278), mud and conglomerate 13:21 1892 291 X=145, Y=236, mud and conglomerate 13:22 1887 291 mud and conglomerate, sponge adhere to rock surface 13:23 1884 282 X=150, Y=208 13:25 1882 284 Observation of slickenside 13:29 1874 269 X=154, Y=191 13:30 1871 284 Stop for observation X=150, Y=180 13:31 1870 275 Flow structure (?) was observed, start to move to 265° 13:34 1864 Steep slope or slope failure (?) 13:37 1864 267 Mud and conglomerate X=143, Y=120 13:44 1854 264 Mud and conglomerate, X=140, Y=30

13:47 1855 218 Change heading to 230° , mud and conglomerate, huge block was observed on surface, X=140, Y=2

13:51 1854 Scattered distribution of rock fragments on surface 13:52 1851 238 Observation of octopus, X=77, Y=-54 13:57 1849 218 Stop for observation of octopus 14:07 1849 217 Finish of observation and start to move to 230° 14:13 1840 231 Mud and conglomerate

14:14 1836 247 Arraival at atop of Celestial SMT, where was observed conglomerate (serpentine?) and surface morphology was rough.

14:23 1835 266 Stop for sampling, X=-10, Y=-160 Report from Shinkai (sampling of 3 rocks and push core (red), this location is "stop4", X=-10,

14:24 1836 273 Y=-160) 14:33 1832 235 Start to move to 230° 14:35 1835 139 Mud and conglomerate, X=-41, Y=-181 14:37 1839 129 Change heading to 130° 14:38 1851 118 X=-98, Y=-150 14:41 1855 50 Mud and conglomerate, X=-100, Y=-100 14:43 1852 75 mud and conglomerate, X=-87, Y=-82 14:46 1852 78 Mud and conglomerate, X=-91, Y=14 14:48 1852 64 X=-87, Y=20 14:51 1862 74 Mud and conglomerate, X=-87, Y=57 14:59 1863 185 X=-130, Y=160

15:04 1872 181 Arraival at slope basement, slope was covered with conglomerate (talus deposits?), Shinkai go down along slope

15:06 1872 100 Mud and conglomerate, X=-200, Y=300 15:09 1867 101 Mud, X=-220, Y=330 15:10 1866 113 Zoom up blocky rock on surface (mud) 15:11 1865 111 Mud and conglomerate, X=-254, Y=400 15:15 1868 111 Mud and conglomerate, X=-303,Y=464 15:17 1872 111 X=-320, Y=490 15:20 1876 111 Scattered distribution of small rock fragments on mud cuvered surface 15:24 1870 76 Zoom up rock surface coated with manganese?, stop for rock sampling 15:44 1871 149 Report from Shinkai (sampling of 5 rocks, this location is "stop5", X=-410, Y=600) 15:48 1869 170 Start to move to 110° 15:50 1870 108 Depression or small down step? X=-433, Y=616 15:53 1879 79 X=-470, Y=-664 15:55 1880 Stop for core sampling, MBARI (green) 15:59 MBARI (yellow) 16:05 1881 335 MBARI (black, white)

Report from Shinkai (sampling of 4 MBARI, this location is "stop6", X=-475, Y=670, and 16:10 1881 leave bottom)

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Date: 11 September, 2003 Site Name: Big Blue Seamount Landing: 10:52; 18°05.8405'N, 147°06.5462'E, 1431m Leaving: 16:10; 18°06.5003’N, 147°06.1276’ E, 1263m Observer: Kantaro Fujioka (ORDept, GODI) Pilot: K. Iijima, Co-Pilot: Y. Ohno

Objectives: Major objectives are two holds on this dive 783: 1) reconnaissance of the serpentine seamount around the Big Blue Seamount summit 2) sampling seeping, rocks, cores and sediments.

Dive Summary: We landed at the boundary between present calcareous sediment with ripple marks and old serpentine mud flow deposit and took 3 rocks and one push core sample at water depth of 1431 m. Then start to go to 90° direction. Small E-W trending ridge and trough with 4m depth structure consisting of the old serpentine flow deposits are seen. Talus debris forming a debris fan make a clear topographic inflection point is the present calcareous sand, may be foraminifers sand. We then climbing up the main body of the Big Blue seamount. Steep slope consisting of an old serpentine mud and debris canyon that the pebbles were washe out from the serpentine mud. The countless amounts of the old serpentine mud forms gentle bedding plane and piles up to form a slope. At water depth of 1267 m we stop to observe the elongated hole that was the result of the landing of some apparatus. We saw white carbonate sediments inside the hole and took 2 35 cm-long MBARI tube samples which show the different lithology. The upper 2/3 consists of white calcareous mud and the lower part consists of grayish blue serpentine mud. No clear shimmering was seen from the hole. From the final wall of the peak notable two white ridges were seen with small shell fragments. We tries to find any shimmering and carbonate chimneys but did not. We climbed up to the summit of the seamount, the depth was 1232 m by our sub’s depth meter. Rather narrow summit was formed by carbonate encrust white sediments, may be serpentine mud represent chaotic structre, say the field of under-construction of a house or a building of China. We saw tiny shell fragments everywhere but did not find an active seepage nor carbonate

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chimneys. We decided to go back to stop 5 where we saw two notable white ridge. Finally we took 2 MBARI cores and scoop sampling of pebbles there. The Big Blue Seamount as a whole is a young serpentine seamount just stopped its activity or at the dormant stage of its activity judging from the freshness of sediments and fossil bivalve reservation. Through the several dives to S. Chamorro, Bluemoon, Celestial, and Big Blue seamounts we tentatively conclude that the activity of seepage is something to the following order; S. Chamorro, Big Blue, Celestia,l and Bluemoon.

During this dive we collected 13 rocks, 3 push cores, 4 MBARI cores, 2 scoop samples, 1 Niskin bottle sample and 325still photos of the external camera 2 No. Vide and 2 No. 2 video records and continuous record of StrataBox and three-component magnetometer data were obtained along the ship’ tracks. During this dive, most of the primary objectives were met. However, we still need survey and sampling from the eastern and northwestern slopes of the Big Blue Seamount where a huge collapse structure is seen in the bathymetric map.

Keywords: Forearc, cold seep, peridotite, serpentine, STR-ISCS

Payloads: 1) WHATS with a temperature probe for fluid sampling 2) Bag pomp sampler 3) Sample box x2 4) MBARI core sampler 35cm x2 and 50cm x2 (MY; Yellow, MG, green) 5) Niskin bottle x2 6) STR-ISCS-1, -2, -3 (60 cm length) 8) Scoop 9) Homer x1 10) Marker x3

Location of Events: Time Position Depth Event 10:52 18˚05.8405'N, 147˚06.5462'E, 1431m Landing on the boundary between

serpentine mud and pelagic

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sediments Sampling 3 rocks 12:08 18˚06.0328'N, 147˚06.5382'E, 1425m Sampling 1 rock push core 13:09 18˚06.2894'N, 147˚06.3750'E, 1324m Sampling 3 rocks push core 14:00 18˚06. 4023'N, 147˚06.2035'E, 1269m Sampling 4 rocks MBARI(S x 2) 15:02 18˚06.2894'N, 147˚06.3750'E, 1234m Sampling push core 16:07 18˚06.5039'N, 147˚06.1276'E, 1271m Sampling 3 rocks MBARI(L x 2) 16:10 18˚06.5003'N, 147˚06.1276'E 1263m Leaving the bottom Niskin

Video Digest: 18:52:17-18:52:48 31 CAM2 fish, sea anemone and serpentine mud

13:25:54 –13:26:32 36 CAM2 13:32:44-13:33:10 26 CAM2 13:39:02-13:39:30 28 CAM2 Artificial hole, carbonate sediments and MBARI

13:54:52-13:55:55 63 CAM2 Swimming sea anemone

14:02:21:-14:02:42 21 CAM2 Shark is swimming with us

14:15:43-14:16:30 47 CAM2 White ridges and shell fragments

14:59:54-15:00:21 27 CAM2 Summit of Big Blue Seamount and push core

15:38:07-15:38:28 21 CAM2 MBARI long coring at white ridge Total 300

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Shinkai 6500 #783 dive Video Log at the control room 11 Sep, 2003 Big Blue Seamount Scientist: K. Fujioka, Pilot: K. Iijima, Co-pilot: Y.Ohno

T ime Depth S.H Description 9:10 Swimmer stand by

10:00 Vent open 10:48 1431 Talus deposits? 10:49 1431 201 Zoom up fish 10:50 1431 203 Talus deposits are composed of rounded rocks 10:52 1432 203 Report from Shinkai (landing, water temp.=3.5° C, X=-1030, Y=970)

Report from Shinkai (3 rocks sampling, this location is "stop1", X=-1030, 11:18 1433 149 Y=970, start to move) 11:20 1431 79 X=-1090, Y=970 11:21 1434 0 Huge blocky rocks 11:22 1435 4 Mud surface and ripple mark (X=-1020, Y=970) 11:24 1433 4 X=-1010, Y=970 11:27 1426 4 X=-920, Y=970 11:28 1423 4 Small step (apron of serpentine flow?) 11:29 1424 358 X=-830, Y=965 11:32 1430 0 Scattered distribution of rock fragments on mud 11:36 1427 331 X=-685, Y=954 11:39 1425 278 Stop for sampling 11:53 1425 302 Sampling using scoop 12:01 1425 303 Push core (red)

Report from Shinkai (push core (white) and sampling by scoop, this location is 12:09 "stop2", X=-680, Y=940, start to move) 12:16 1399 330 X=-544, Y=916

12:17 1393 331 Arraival at basement of slope and talus deposits were observed, Shinkai start to climb along slope

12:20 1378 330 X=-430,Y=860 12:24 1361 311 X=-342, Y=772 12:27 1343 311 X=-280, Y=710 12:29 1338 310 Small rock fragments were observed 12:32 1326 310 X=-220, Y=656 12:33 1323 311 Stop for sampling

Report from Shinkai (3 rocks, push core (blue) and sampling by scoop, this 13:09 1324 location is "stop3", X=-220, Y=650) 13:12 1315 Start to move to 310° 13:14 1304 311 Apron of serpentine mud flow? 13:16 1297 311 X=-141, Y=555 13:19 1286 311 X=-80. Y=483 13:22 1275 311 X=-40, Y=430 13:31 1269 322 Sampling of MBARI (white, yellow)

Report from Shinkai (4 rocks, MBARI (white, yellow) and sampling by scoop, this ‹ location is "stop4", X=10, Y=380, start to move to 310 )

14:02 1266 325 Fish 14:06 1267 311 X=63, Y=330 14:10 1266 Rock fragments deposits on flat surface 14:12 1273 337 X=190, Y=270 14:15 1273 337 Stop for observation (X=180, Y=270)

Small rock fragments with sharp edge are deposits on mud, finding shell fragments, 14:16 1273 337 this location is "stop5" (X=190, Y=230) 14:24 1265 338 Start to move 14:27 1254 341 X=228, Y=207 14:29 1254 341 Observation of rocks and mud, X=270, Y=190 14:33 1237 2 Observation of serpentine mud? X=332, Y=162 14:36 1233 31 Observation of mud surface and fish, X=398, Y=195 14:40 1234 318 Mud, X=455, Y=204 14:45 1236 160 Mud with rock fragments, X=503, Y=218 14:58 1234 179 Sampling of push core (red), this location is "stop6", X=460, Y=200

Start to move to X=190, Y=270 (stop 5) 15:06 1233 190 X=407, Y=177 15:10 1237 191 X=331, Y=157 15:12 1261 190 X=240, Y=120 15:17 1271 94 X=175, Y=125 15:20 1272 100 X=161, Y=169 15:21 1271 99 Dence distribution of small rock fragments and rocks 15:26 1271 73 Zoom up small rock fragments 15:28 1271 85 Small rock fragments and rocks, X=191, Y=224 15:33 1271 84 MBARI (blue) 15:44 1271 93 MBARI (green)

Report from Shinkai (3 rocks, MBARI (blue, white) and sampling by scoop, this 16:07 location is "stop7", X=194, Y=226) 16:10 1273 Leave bottom

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Date: 13 September, 2003 Site Name: Pacman Seamount Landing: 11:32; 19°10.7035’N, 147°03.7856’E, 3562m Leaving: 15:47; 19°10.2062’N, 147°03.0424’E, 3458m Observer: Hisako Hirayama (SUGAR Project, JAMSTEC) Pilot: Y. Sasaki, Co-Pilot: M. Yanagitani

Objectives: In 1993 the southeastern arm of the crescent-shaped serpentine seamount Pacman Seamount was investigated by 6K dive #178 by P. Fryer, in which she discovered small carbonate-chimney structures (19°10.608’N, 147°03.711’E) formed along fissures in NW-SE directed ridge. Moreover Dr. K. Fujioka & Dr. H. Chiba discovered slightly seeping water from a rock and surrounding mud floor covered with thick muddy sediments (19°10.1910’N, 147°03.1000’E) in the record of a video of the dive #178 on board in this cruse YK03-07, although Dr. Fryer never mentioned about those seeping in the video and her cruise report. Then this dive #784 was planed to trace the two sites (chimney and cold-seep) found in dive #178. Two major objectives are underlying on this dive #784: 1) Mapping the chimney sites and sampling chimneys and cold-seep water from the chimney 2) Search of the cold-seep sites and sampling seeping water in the southeastern arm of the Pacman Seamount.

Dive Summary: We landed at approximately 230 m northeast from the chimney site found in dive #178. The landing point (19°10.7035’N, 147°03.7856’E, 3562m) was covered with thick muddy sediments containing abundant animal tracks and ripple marks showing the flows from west to east. We ran to the chimney site, and found only a block of chimneys beside fissures in N-S directed ridge (19°10.6171’N, 147°03.7510’E, 3548m). Here we sampled 3 pieces of chimney structure and settled marker #77. After chimney sampling, we ran to south along the fissures in N-S directed ridge to seek more chimneys. Next, many E-W directed ridges were found with so many fissures. These ridges should be serpentine mud flows covered with thick muddy sediments, but no chimney was found around there. We gave up chimney, and headed to southwest for cold-seep sites.

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To the next target site (19°10.1910’N, 147°03.1000’E) on which seeping water was observed in a video of the dive #178, we sped up and just carefully observed whether cold-seep was there from the rocks or sea floor. It was a gentle ascent to the target site. On the way, so many animal tracks, spiral trails of animal excrement, and animal burrows were found on the muddy sea floor. Several sea cucumbers, sea urchin, starfish, red shrimp, and jellyfish-like were also observed. After we reached near the target site, we slowed down the speed and further carefully observed the sea floor. We ran around the target point widely for two hours, but the landscape was just same as those on the way to this site, that is, muddy floor with only abundant animal tracks and several animals. Finally we couldn’t find the cold-seep or related chimney structure. Before leaving the bottom, we sampled two MBARI cores and one niskin water at the muddy sediment site (19°10.2062’N, 147°03.0424’E, 3458m)

Keywords: Chimney, cold seep, serpentine

Payloads: 1) WHATS with a temperature probe for fluid sampling2) Bag pump sampler3) Niskin bottle (x2)4) MBARI core sampler (x5; 35cm x2 and 50cm x3)5) German core sampler (x1)6) Push core sampler (x1)7) Sample box (x2)8) Scoop10) Marker (x3)

Location of Events: Time 11:32 1.5˚C) 12:18

Position 19°10.7035’N, 147°03.7856’E,

19°10.6171’N, 147°03.7510’E,

Depth 3562m

3548m

Event Landing on muddy floor (t =

Sampling 3 pieces of chimney Settled marker #77

15:47 19°10.2062’N, 147°03.0424’E, 3458m Sampling two MBARI cores Leaving the bottom

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Video Digest: 11:49:15-11:49:30 11:52:29-11:52:41 11:55:20-11:55:50 12:07:20-12:07:52 Carbonate chimney

CAM2 CAM2 CAM2 CAM2

13:47:39-13:47:45 Animal tracks

CAM2

13:39:28-13:39:32 Sea urchin

CAM2

13:46:42-13:46:51 13:58:22-13:58:25

CAM2 CAM2

Sea urchin or jellyfish-like ?

13:58:47-13:58:50 CAM2 Starfish

13:09:58-13:10:04 CAM2 14:55:30-14:55:36 CAM2 Sea cucumber

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Shinkai 6500 #784 dive Video Log at the control room 13 Sep 2003, Pacman Seamount Scientist: H. Hirayama, Pilot: Y. Sasaki, Co-pilot: M. Yanagitani

Time Depth S.H Description 9:10 Swimmer stand by 9:57 Vent open

11:29 3561 208 Observation of mud and biological trail 11:32 3561 Landing, water temp.=1.5° C, X=380, Y=500 11:34 3561 Start to move to 210° 11:37 3558 211 Weathered rocks and mud 11:38 3556 Change heading to 200° , X=344, Y=460 11:41 3553 200 Mud and biological trail, X=293, Y=457 11:44 3551 187 Apron of mud flow, X=250, Y=440 11:47 3347 186 Start to move 11:50 3347 219 Finding small chimneys, X=214, Y=433 11:57 3546 192 Stop for sampling

Sampling of chimneys and carbonates, deployment of #77 marker, X=211, 12:18 3546 205 Y=444 12:20 3548 189 Moving along crack 12:25 3546 173 X=199, Y=456 12:26 3545 163 Apron of mud flow 12:27 3545 167 Weathered chimney? observation of around this stop site until 13:00 12:37 3545 171 Sampling of rock, X=150, Y=424 12:54 3546 302 X=408, Y=380 12:56 3546 189 X=170, Y=380, observation of cross section of mud flow 13:01 3545 192 Stop for search of chimney 13:03 3546 240 Start to move to 230° 13:04 3546 230 Thickly mud covered surface 13:05 3547 236 X=112, Y=363 13:08 3551 231 Mud and biological trail, X=63, Y=326 13:10 3540 231 Mud and biological trail, X=32, Y=277 13:14 3524 231 Mud and biological trail, X=30, Y=200 13:18 3506 231 Mud and biological trail, X=-85, Y=137 13:20 3492 231 X=-120, Y=90 13:21 3489 220 Change heading to 200° 13:23 3483 201 X=-202, Y=30 13:25 3477 201 Mud and biological trail, X=-270, Y=10, change heading to 250° 13:29 3474 251 Mud and biological trail, X=-346, Y=-84 13:33 3460 246 Mud and biological trail, X=-400, Y=-193 13:35 3457 246 Mud and biological trail, X=-420, Y=-200 13:39 3455 246 Mud and biological trail, X=-469, Y=-343 13:44 3446 251 Mud and biological trail, X=-498, Y=-448 13:46 3449 251 Mud and biological trail, X=-510, Y=-470 13:49 3450 280 Mud and biological trail, X=-521, Y=-517 13:53 3450 213 Mud and biological trail, X=-580, Y=-540, change heading to 270° 13:56 3452 270 Mud and biological trail, X=-588, Y=-578 13:59 3450 181 Mud and biological trail, X=-620, Y=-590 14:03 3447 181 Mud and biological trail, X=-672, Y=-587 14:06 3446 181 Mud and biological trail, X=-700, Y=-580 14:08 3446 359 Change heading to north 14:11 3448 341 Mud and biological trail, X=-680, Y=-590 14:15 3450 341 Mud and biological trail, X=-530, Y=-640 14:17 3450 340 Change heading to 270° 14:20 3458 271 Mud and biological trail, X=-476, Y=-678 14:23 3456 271 Mud and biological trail, X=-470, Y=-720 14:27 3456 298 X=-466, Y=-761, finding sea whip 14:35 3457 321 X=-456, Y=-806, observation of weathered rocks 14:38 3455 328 X=-450, Y=-830 14:42 3456 235 Apron of mud flow including rocks 14:43 3456 Start to move 14:47 3457 182 Mud and biological trail, X=-490, Y=-825 14:50 3457 225 X=-523, Y=-831, observation of sea whip 14:52 3457 178 X=-536, Y=822, observation of cross section of mud flow 14:55 3457 220 X=-540, Y=-850, observation of chimney-like structure 14:59 3457 181 X=-610, Y=-739 15:07 3459 42 Mud and biological trail, X=-608, Y=-739 15:10 3457 23 Mud and biological trail, X=-570, Y=-700 15:14 3457 243 Mud and biological trail, X=-537, Y=-737 15:20 3457 53 X=-532, Y=666, observation of sea whip 15:26 3458 91 Mud and biological trail, X=-532, Y=-666 15:40 3458 298 Stop for sampling 15:42 3458 313 Niskin sampling 15:43 3458 325 MBARI (green) 15:47 3458 344 MBARI (yellow), X=-541, Y=-802, leave bottom

85


Date: 14 Sept., 2003 Site Name: Conical Seamount Landing: 19°32.2306’N, 146°38.9280’E, 3130m Leaving: 19°32.3181’N, 146°39.0042’E, 3124m Observer: Chitoshi Mizota (Faculty of Agriculture, Iwate University) Pilot: Y. Sakurai and Y. Ohno

Objectives: Three major objectives are underlying on this dive #785: 1) sampling matrix clay and associated xenolith including peridotite of upper mantle origin and high-temperature metamorphic rocks in serpentine mud flow, 2) sampling of chimney consisting of carbonates/Mg-silicates and long-lived sea anemone, and 3) examining Ocean Drilling Project Hole 780 A, B, C and D.

Dive Summary: Before landing (about 5m above), a Niskin sample water was obtained. We have

landed on a gentle slope (south-west facing) of Conical Seamount. The landing point was covered by white sand with rounded, small ridge of the serpentine mud flow. After landing, we tried to look out the “graveyard” areas which consist of upstanding chimney. We spent almost one hour to look out the chimney. We found carbonate chimneys with gigantic sea anemone atop carbonate chimney. We sampled four samples of upstanding chimney with black manganese coating. We failed to sample the sea anemone due to the very fragile nature. Moving short time (three minutes) southwest, we sampled one MBARI core on a serpentine mud flow. Due to poor performance of No.2 battery, we have to decided to leave at 14.30. We could not have enough time to visit ODP site 780.

Keywords: Forearc, serpentine mud volcano, carbonate chimney, sea anemone, OPD Hole 780

Payloads: 1) WHATS with a temperature probe for fluid sampling 2) Bag pomp sampler 3) Sample box x2 4) MBARI core sampler, 35cmx2 and 50cmx4 (MY; yellow, MG; green)

86

5) Niskin bottle x2 6) Scoop 7) Marker x2

Location of Events: Time Position Depth Events 11:25 19°32.2306’N, 146°38.9280’E 3130m Niskin No.1, and landing on

sand floor 14:06 19°32.3206’N, 146°38.9268’E 3127m Sampling carbonate chimney

x4, MBARI (L: yellow, S:

white) x2 14:22 19°32.3300’N, 146°38.9249’E 3125m Sampling MBARI (L: green) x1 14:33 19°32.3181’N, 146°39.0042’E 3124m Leaving the bottom

Video Digest: {View from No. 2 Camera}

13:11:00 – 13:12:20 Sea anemone 13:14:40 – 13:16:00 Sampling of chimney 13:20:00 – 13:21:00 Close-up of chimney surface

87

Shinkai 6500 #785 dive Video Log at the control room 14 Sep 2003, Conical Seamount Scientist: C. M izota, Pilot: T. Sakurai, Co-pilot: Y. Ohno

Time Depth S.H Description 9:10 Swimmer stand by 9:57 Vent open 11:18 3130 35 Sampling (Niskin), X=-121, Y=-130 11:20 3130 276 Mud flow (small depressions were observed) 11:22 3130 249 Broken chimney? or weathered rocks? 11:24 3130 249 Landing, water temp.=1.5° C, X=-130, Y=-120 11:29 3130 217 Start to move to 350° 11:29 3130 309 Stop for observation of cliff, X=-141, Y=-128 11:34 3130 318 Finish of observation of clif, start to move to 350° 11:38 3125 351 Terrace, X=-80, Y=-122 11:42 3120 319 Change heading to 320° 11:43 3120 319 X=-29, Y=-116 11:45 3122 320 X=0, Y=-140, observation of debris flow deposits 11:47 3125 269 Weathered rocks were observed 11:48 3124 265 Change heading to 270° 11:53 3125 242 X=50, Y=-190 11:55 3127 190 Change heading to 190° 12:00 3128 189 X=-40, Y=-200 12:07 203 X=-160, Y=-180 12:11 3143 284 X=-280, Y=-180 12:13 3149 197 Mud and ripple mark 12:14 3150 150 X=-350, Y=-170 12:15 3150 39 X=-360, Y=-170 12:17 3150 350 Change heading to 10° 12:20 3141 327 X=-263, Y=-128 12:24 3129 344 X=-165, Y=-125 12:29 3122 267 X=-43, Y=-114 12:32 3121 X=-50, Y=-110 12:33 3121 293 chimney? 12:38 3125 321 X=30, Y=-150 12:39 3126 Change heading to 250° 12:44 3126 249 X=30, Y=-210 12:52 3129 172 X=-50, Y=-200

12:55 3125 352 Finding seaanemone, stop at chmney site of #179? (X=40, Y=-126), waiting until good visibility

13:12 3127 303 Try to sampling of chimney Report from Shinkai (3 chimneys, MBARI (white,

14:07 3127 325 black)), X=40, Y=-30 14:14 3126 308 Stop for sampling of mud flow 14:21 3125 Report from Shinkai (MBARI (yellow)), X=53, Y=-128 14:28 3124 248 X=50, Y=10

14:31 3124 Leave bottom (accidental trouble of No.1 battery), X=30, Y=10

88


Date: 15 September, 2003 Site Name: Eastern wall of Coni-Pac Triangle Landing: 11:02; 19°38.3231’N, 147°4.3074’E, 4839m Leaving: 15:08; 19°38.2639’N, 147°5.6378’ E, 4282m Observer: Hirokazu Maekawa (Department of Earth and Life Sciences, College of Integrated Arts and Sciences, Osaka Prefecture University) Pilot: Y. Nanbu, Co-Pilot: M. Yanagitani

Objectives: Three major objectives of this dive 786 are as follows: 1) analysis of serpentine and

debris flow sequences, 2) sampling of ultramafic rocks to compare serpentine mineral with those from Conical Seamount and examine lateral variation of serpentine mineral from trench to eastward, and 3) sampling of metamorphic rocks and flow matrix to estimate the source of flow.

Dive Summary: We landed at approximately 400m north of the planed landing point, on the way of

Dive #180 investigation path. Landing point was muddy seafloor with cobbles to pebbles of metadolerite (Stop 01: 19˚38.3231'N, 147˚4.3074'E, 4839m). Muddy seafloor consists probably of serpentine mud or mafic mud materials. We sampled 3 rocks. One is metadolerite and two are consolidated serpentine mud. After landing, we run up eastward to the top of slope. Debris channels are developed on the faces of the slope, making a series of ridge and trough in the slope. At Stop 02 (19°38.2581’N, 147°4.4253’E, 4760m), several tens-meter blocks are scattered in the brown colored matrix. Most of blocks are mudstone, but some are consolidated serpentine mud. We took two samples. One is hard siltstone with clear bedding and another is pale-green mudstone with 1-3mm subrounded to subangular fragments of serpentinite. We took also a long push core, but only 10cm brown mud materials were obtained. East to the Stop 02, mud flow is widespread. Blocks of varying sizes are unevenly distributed. In steep slope bedded mud layers with northwesterly strike and dip westward to 20° are often observed. Each bed is thought to represent a unit of flow. At Stop 03 (19°38.2447’N, 147°4.4810’E, 4731m), we sampled one brown siltstone and many small subrounded pebble- and cobble-sized siltstones by scoop. On the way to the Stop

89

04 (19°38.2053’N, 147°5.2064’E, 4408m), we tried to take samples at three locations, but all are soft semi-consolidated mudstone and we didn’t take any sample there. We took two mudstones and one MBARI core (50cm) at Stop 04, and used scoop and one MBARI core (35cm) for sampling at Stop 05 (19°38.2165’N, 147°5.4864’E, 4362m). Together with abundant mud materials, small fragments of varying types, such as manganese crust, siltstone, metabasalt to metadolerite, and possibly serpentine, are obtained by scoop. Dark brownish mud of 10-15cm thick was only recovered by MBARI cores. Finally in the outcrops with many blocks, we took three rocks (Stop 6: 19°38.2639’N, 147°5.6378’E, 4282m). Two are reddish brown in color and are possibly altered peridotite or igneous rock), and one is dark greenish metadolerite. We also took one MBARI core (35cm) and one push core, and obtained many small fragments of various rock types at Stop 6.

Although the surface layer of unconsolidated mud pervasively covers outcrops, we regard that the slope is essentially composed of thick piles of sedimentary flows due to gravity sliding of serpentinite and surface mud cover. During this dive we collected 10 rocks, 2 push cores, 3 MBARI cores, 2 scoop samples, 400 still photos of the external camera, 2 No. 1 video and 2 No. 2 video records.

Keywords: Mariana, Coni-Pac triangle, forearc, serpentinite, serpentine mineral, serpentine flow

Payloads: 1) Sample box x3 2) MBARI core sampler 35cm x2 and 50cm x1 3) Long push core (50cm) x1 4) Push core x3 5) Scoop 6) Marker x1(not used)

Location of Events: Time Position Depth Event 11:02 19˚38.3231'N, 147˚4.3074'E, 4839m STOP 01: Landing on muddy

seafloor with blocks of varying sizes. Sampling three rocks

11:53 19°38.2581’N, 147°4.4253’E, 4760m STOP 02: Sampling two rock and

90

Core (long) x1 12:16 19°38.2447’N, 147°4.4810’E, 4731m STOP 03: Sampling one rock and

Scoop 13:47 19°38.2053’N, 147°5.2064’E, 4408m STOP 04: Sampling one rock and

MBARI (50cm) x1 14:21 19°38.2165’N, 147°5.4864’E, 4362m STOP 05: Sampling MBARI

(35cm) x1 and Scoop 15:08 19°38.2639’N, 147°5.6378’E, 4282m STOP 06: Sampling three rocks and

MBARI (35cm) x1

Video Digest: 10:58:12-10:58:42 30 CAM1 Frequent outcrop view: serpentine and mud flows

11:31:30-11:31:55 25 CAM1 Frequent outcrop view: serpentine and mud flows forming ridge

12:22:00-12:22:40 40 CAM1 Blocks scattered in mud matrix

11:59:10-11:59:35 Flow direction

25 CAM2

13:02:15-13:02:45 mud flow without any block

30 CAM2

14:17:50-14:18:50 Sampling by scoop at Stop 05

60 CAM2

14:20:35-14:21:35 60 MBARI sampling at Stop 05

CAM2

14:49:10-14:49:40 Sampling rock at Stop 06

30 CAM2

91

Shinkai 6500 #786 dive Video Log at the control room 15 Sep 2003, Coni-Pac Triangle Scientist: H. M aekawa, Pilot: Y. Nanbu, Co-pilot: M. Yanagitani

Time Depth S.H Description 8:10 Swimmer stand by 8:56 Vent open

11:03 4839 185 Landing, water temp.=1.4° C, X=40, Y=-1370 11:19 4839 196 Report from Shinkai (sampling of 3 rocks, this location is "stop1", X=40, Y=-1370) 11:21 4836 107 Seaanemone adhere to rock 11:23 4827 132 Start to move to 130° 11:25 4813 125 Scattered distribution of rock fragments on mud 11:30 4781 134 Weathered rocks 11:31 4772 155 X=-30, Y=-1200 11:34 4768 159 Weathered mud (serpentine?) flow was observed

11:54 4759 159 Report from Shinkai (sampling of 1 rock, push core (black long), this location is "stop2", X=-80, Y=-1180), start to move to 135°

12:04 4731 169 Report from Shinkai (sampling of 1 rock, scoop sampling, this location is "stop3", X=100, Y=-1080), start to move to 135°

12:25 4690 90 X=-90, Y=-930 12:30 4637 112 Outcrop, steep slope, X=-97, Y=-813 12:32 4636 119 Finish of outcrop 12:36 4618 151 Stop for sampling 12:44 4615 154 Cancel of sampling 12:48 4589 128 Land scape? X=-155, Y=-720 12:51 4588 114 Flat surface covered with mud and biological trail was observed 12:53 4573 93 X=-196, Y=-648 12:55 4552 103 X=-99, Y=-523 12:57 4546 101 Observation of mud flow unit 12:58 4536 135 X=-220, Y=-450 13:01 4525 83 Weathered mud flow 13:04 4516 83 Gentle slope covered with mud, X=-228, Y=-354 13:08 4498 83 Gentle slope covered with mud, X=-220, Y=-210 13:11 4473 84 X=-197, Y=-127 13:12 4470 86 Stop for sampling, weathered mud flow 13:20 4466 83 Cancel of sampling, X=-190, Y=-110, start to move to 90° 13:24 4446 83 Gentle slope covered with mud 13:30 3326 91 X=-180, Y=80

13:48 4404 88 Report from Shinkai (sampling of 2 rocks and M BARI (blue), X=-189, Y=190, this location is "stop4")

13:53 4386 81 X=-185, Y=253, mud 13:54 4384 Observation of rocks on mud, ripple mark 13:58 4382 84 Mud and biological trail, X=-166, Y=432 14:00 4381 84 Mud and biological trail, X=-160, Y=470 14:04 4368 53 Mud, X=-143, Y=583 14:06 4362 27 Stop for sampling of scoop

14:21 4356 21 Report from Shinkai (scoop, M BARI (green), X=-160, Y=600, this location is "stop5")

14:28 4344 32 Stop for sampling 14:37 4322 53 X=-140, Y=710 14:41 4303 62 X=-101, Y=807 14:43 4301 62 X=-100, Y=830 14:45 4284 61 X=-84, Y=919 14:49 4282 320 Stop for sampling 15:00 4282 Sampling of 3 rocks 15:05 4283 Push core (stripe of black and yellow) 15:07 4283 MBARI (black) 15:09 4282 Leave bottom, X=-66, Y=940, this location is "stop6"

92

V. PRELIMINARY RESULTS

MICROBIOLOGY

During this cruise, we had a variety of samples from the TOTO cauldron deepsea hydrothermal field and the Mariana Forearc serpentine seamounts such as the South Chamorro Seamount. These samples will be investigated onshore as described in the Section of Onshore Study. Here, we can just indicate the preliminary results of the temperature shift profiles of the STR-ISCS deployed in the hydrothermal vent sites in the TOTO cauldron. Both STR-ISCS were incubated for 4 days. The average

Tem

pera

ture

(ÞC

)

temperature of the ISCS deployed in a sulfur chimney was 108 ˚C. In a clear smoker simmering, there was tendency of rise in temperature 20-40 ˚C in the first day but continuously 80˚C in the subsequent days. The tendency of rise in temperature suggested the sealing by sulfur on the top of the ISCS had occurred. Fig. Temperature shift profile of the ISCSs deployed in a sulfur chimney and a clear smoker simmering site of the TOTO cauldron.

Deployment of STR-ISCS in 108ÞC vent site Deployment of STR-ISCS in 108ÞC vent siteSTR-ISCS retrieval STR-ISCS retrieval

120 120

100100

Tem

pera

ture

(ÞC

) 80 80

60 60

40 40

2020

0 0 2003.8.27 6:31

2003.8.26 20:35

2003.8.26 10:39

2003.8.26 0:43

2003.8.25 14:47

2003.8.25 4:51

2003.8.24 18:55

2003.8.27 6:31

2003.8.26 20:35

2003.8.26 10:39

2003.8.26 0:43

2003.8.25 14:47

2003.8.25 4:51

2003.8.24 18:55

Date Date

GEOCHEMISTRY

1. Results of onboard analyses of fluid samples collected by WHATS, Bag Sampler, and Niskin Sampler Fluid samples collected by various fluid samplers are analyzed for pH, alkalinity, and

silica and NH4 concentrations. Results are listed in the following Table.

93

Results of onboard chemical analysis of fluid samples collected during YK03-07

Dive No. Sample # pH alk. (meq/L)

Si (mM/L)

NH4 (mM/L)

TOTO Caldera #772 N1 N2

pump W2 W4

7.63 7.36 5.69 5.35 5.16

2.37 2.39 2.4

2.33 4.74

0.25 0.17 1.14 1.36 2.68

0.41 0.30 0.12 0.09 0.38

#773 N1 N2

pump W3

7.43 7.51 5.43 5.21

2.47 2.46 2.78 4.76

0.15 0.28 0.74 2.22

0.33 0.36 0.27 0.70

#774 N1 N2

pump W2 W4

7.54 6.46 5.24 5.96 5.26

2.85 2.45 3.5

18.92 4.14

0.21 0.26 4.47 2.67 3.13

0.55 0.53 0.43 0.44 0.39

#775 N1 pump W3

7.50 3.18 1.83

2.63 -0.93

-18.18

0.17 1.29 9.33

0.30 0.12 0.38

#776 N1 W3

6.83 1.59

2.31 -20.6

0.25 11.60

0.13 0.16

South Chamorro Sm #777 N1 N2 W2 W4

7.61 7.78 7.69 8.03

2.73 2.61 2.71 2.49

0.17 0.16 0.17 0.20

0.20 0.31 0.31 0.20

#778 N1 N2 W2 W4

7.56 7.57 7.69 7.74

2.54 2.5

2.49 2.45

0.12 0.12 0.13 0.11

0.25 0.25 0.19 0.21

#779 --

#780 pump W3

7.36 7.50

2.73 2.47

0.13 0.13

0.26 0.26

Bluemoon Smt. #781 N1 7.52 2.72 0.05 0.18

Big Blue Smt. #783 N1 7.42 2.54 0.09 0.19

Pacman Smt. #784 N1 7.57 2.49 0.11 0.13

Conical Smt. #785 N1 7.58 2.49 0.09 0.34

2. Results and brief discussions of pore water samples at Mariana Serpentine Seamounts Some of the core samples taken by MBARI corer at Mariana Serpentine Seamounts

were squeezed to collect pore water samples. They were measured for pH, alkalinity, and salinity onboard. The results are listed in the following Table.

94

Preliminary Results of Pore Water Analyses during YK03-07 Cruise.

Dive No. depth amount pH Alkalinity salinity remarks Name of Smt. (cm) (ml) (meq/l) (‰)

778 0-4 26 7.68 2.83 35 yellow sediment with pebbles S. Chamorro Smt. 4-6 30 7.76 2.94 35 boundary, clay

6-11 26.5 7.84 2.87 34 black sediment 779 0-5 32 8.36 2.89 35 brown sediment

S. Chamorro Smt. 5-10 32.5 8.37 3.05 35 boundary of brown and black sediment, not completely squeezed 10-15 20 8.39 3.32 35 black sediment 15-20 16 8.42 3.41 35 black sediment

780 0-5 25.1 7.74 2.44 36 brown sediment S. Chamorro Smt.

782

5-10 10-15 0-8

28.4 22 12

7.92 8.02 7.66

2.68 2.70 3.35

36 boundary of brown and gray sediments 35.5 gray sediments

35 brwon pelagic sediment, unusual high alkalinity* Celestial Smt. 8-18

18-28 28-38 38-48

26 23.5

14 17

7.68 7.63 7.63 7.62

2.52 2.49 2.75 2.21

35 brwon pelagic sediment 35 brwon pelagic sediment 35 brwon pelagic sediment 35 brwon pelagic sediment

783 0-10 19 7.81 2.37 35 brown sediment Big Blue Smt. 10-20 13 7.75 2.57 36 brown sediment and boundary

20-30 36.9 7.96 2.75 36 blue sediment 30-40 20 8.22 1.83 36 blue sediment

* Unusually high alkalinity may be caused by fine carbonate particle since the squeezed water is slightly cloudy.

Comparison with fluid samples collected above the seafloor pH range of fluid samples taken above the seafloor by WHATS, Pump, and Niskin

samplers is from 7.36 to 8.03. Except the sample #777 W4 (pH=8.03) which was collected just above the active mussels colony, pH of the fluid samples are very similar to ambient seawater (pH=7.4 – 7.6). Their alkalinity, silica and NH4 concentration are also in the range of ambient seawater. These results indicate the difficulty to detect symptoms of cold seepage and to sample it directly above the seafloor. It is because the very slow upwelling rate of the fluid of deep origin and the reaction which change the fluid composition just beneath the seafloor by mixing with ambient seawater diffusing downward.

Compositions of pore water samples and their depth profiles pH and alkalinity of pore water samples are generally higher than those of fluid

samples collected above seafloor. No anomaly of salinity was detected. Higher pH and alkalinity of pore waters than ambient seawater are symptoms of upwelling deep fluid which is alkaline and high alkalinity. Depth profiles of pH and alkalinity of pore water samples are plotted in the following

Figures. Most of the cores show pH increase with depth. They include all the cores from South Chamorro Seamount and the core from Celestial Seamount. Among them, core taken by #779 at the flat mud close to #75 marker at the South Chamorro Seamount has the highest pHs. Alkalinity of pore water samples also increase with depth in cores at South Chamorro Seamount. However, Cores at Celestial and Big Blue Seamounts do not

95

00

10 10

20 20

Dep

th, c

m

Dep

th, c

m

30 30

40 40

#778 #782 #779 #783 #780

50 50 7.6 7.8 8 8.2 8.4 8.6 1.5 2 2.5 3 3.5

pH Alkalinity, meq/l Depth dependence of pH of pore waters at Mariana Serpentine Smt. Depth dependence of alkalinity of pore water at Mariana Serpentine Smt.

indicate such apparent increases in alkalinity with depth. Therefore, pore water analyses suggest the presence of upwelling deep fluid only at South Chamorro Seamount.

Preliminary concluding remarks Active upwelling of fluid of deep origin was detected only at South Chamorro Seamount by pore water analyses onboard. No symptom for deep fluid upwelling was found at Celestial and Big Blue Seamounts. The cores able to get by a submersible are too short to diagnose precisely the presence of upwelling deep fluid. Longer cores, such as piston or gravity cores, and drilling are necessary for such a diagnosis and estimation of the chemical composition of upwelling deep fluid in the oceanic crust.

TOPOGRAPHY AND GEOLOGY Written by K. Fujioka

General arrangement of the Mariana arc-trench system Mariana arc-trench system MATS is one of the typical oceanic arc and oceanic plate system which extends from the Izu-Bonin arc-trench system to the Challenger deep, almost 2500 km long forming an arcuate morphology toward the Pacific Ocean. The MATS consists of remnant arc, volcanic front, old arc forearc seamount chain

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(serpentine mud volcano) and trench from west to east. Mariana Trough occupies the central part the MATS between remnant arc and volcanic front, spreading since 6 Ma to the present to form a broad almost N-S trending ridge and trough structure. Volcanic front start from the end of the Izu-Bonin arc at around 25N, forming an active volcanic island such as Iwojima Is., Nikkou SMT., Sanpuku SMT., Kasuga SMT., Daikoku SMT., Farallon de Pajaros, Maug Is., asuncion Is., Agrigan, Pagan, Alamagan, Guguan, Zealandia Bank, Sarigan and Anatahan and submarine volcanoes that have no mane making a line with a regular interval. Old arc consists of big islands such as Rota, Saipan and Guam from north to south, however the lineament is truncated at around 18°N to 19.5°N where a huge forearc basin stretches toward east. Forearc seamount chain is a serpentine mud-hosted seamount which will describe below forming another chain like a volcanic front having a regular interval, shape, and size of the seamount.

Recently the MATS was divided morphologically into three or four segments (Stern and Smoot, 1999; Fujioka et al., 2002; Seama et al., 2003). The southern Mariana is a transform fault that extends form Guam to Palau laterally since about 6 Ma (Fujioka, et al., 2002). However Fryer et al (2003) insisted the southern Mariana is not a transform fault but a broken slab forms a roll back movement. Seama et al (2003) and Yamazaki et al (2002) classified the Mariana Trough into four morphological segments and evolutional stages, northern at around 22 to 20 degree, north-central, central and southern respectively. As for the forearc system the four segments seem to be reasonable but it will be more complicated if we take into account the collision of the huge seamount chain at the trench axis. Daton seamount chain and other three chains or volcanoes are colliding with the trench where the forearc morphology is highly disturbed to form extremely shallow, anomalous bathymetry.

I intend here to divide the MATS into four segments northernmost, north, central and south, respectively. The northernmost lies from 25°N to 23°N where no rifting occurs with single volcanic chain. The north segment is from 23° to 20° where intial spreading of the Mariana Trough and a few serpentine seamount at the forearc. The central segment is a dominat part of the MATS starts from 20° to 17°. Here backarc spreading of the Mariana Trough, no Outer arc, many serpentine seamount at the forearc and many collision at the trench axis. The final south segment starts from 17° to 13°N and is truncated at the southern end by transform fault.

At the forearc region of the MATS, serpentine mud volcanoes seem to have a regular interval, shape, and size but have an exception. The distance from one seamount or group of seamounts, to another is about 20 to 30 miles but the distance between North

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Chamorro to Bluemoon is more than 120 miles and between Big Blue to Turquoise is more than 60 miles. In between these intervals it seems to have a seamount-like structure but it is uncertain at this point.

Our bathymetric survey by SeaBeam 2112 with R/V Yokosuka covers more than 2500 mile swath mapping and making a small boxes at Chamorro, Bluemoon, Celestial, Big Blue, Coni-Pac Triangle system.

I intend to describe here the morphologic features of these seamounts and to classify them into two genetic types based on their features. We use the names of seamount that were given by Fryer et al (1999) for the major serpentine seamounts. However for the convenience of the description, the name of the seamounts will be abbreviated shortly as follows; SC:South Cahmorro, NC:North Chamorro, BM: Bluemoon, PC:Peacock, CT: Celestial, TQ:Turquoise, BB:Big Blue, PM:Pacman, CC:Conical, respectively. Table 1 shows the various features of the seamounts.

Morphologic description of the seamounts South Chamorro Seamount (SC SMT)

The SC has a typical conical shape with summit at 13°46’N, 146°01’E.and the water depth of the summit is 2950 m by our SEABEAM 2112 system. The shape of the summit of SC is a small cone like structure but if we look at the shape carefully the NW-SE length is about 4 km longer than that of NE-SW (See Table 1). If we assume the body is a ideal cone we can calculate the volume is something to be 2660 km3 above the basement of the seamount. If the serpentinization of the SC will be 90 % of original peridotite water volume needed to make serpentine minerals is estimated to be 1015 kg. South Chamorro Seamount formation seems to be young but takes about 1 m.y. then we can get a supply rate of H2O from the slab to be 106 t/y. We have an extrapolation concern the water from the sediments of the subducted slab, however it seems to be the waste of time.

We had four dives to the SC #777 to #780 during this cruise but actually we had four more dives were conducted by Shinkai 6500, “280, 281, 351 and by Kaiko #165, from1996 to 2000. OODP Leg 195 cruise drilled several holes around the summit in March, 2001. The Hole 1200 A to F distributed within a narrow area of the north slope at the summit. Hole 1200C has an A-CORK experiment on the seafloor. The most important results of the dives and drilling is that high alkalic and high pH pore fluid makes a seep to sustain chemosynthetic community. We tried to map the distribution of clam communities, markers, holes, and serpentine mud flows and sample cold seep fluid

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by WHATs, Niskin and pump sampler, sediments by push and MBARI corer, rocks and bivalves by manipulator.

The activity of the cold seep seems to be weak compared with that at the time of #165 dive by Kaiko, 2000 based on the ratio of living clams at the same site. We observed vary curious sediments thinly covering the previously living clam community that is now almost extinct by the newly rapid supply of the artificially caused flood of drilled sediments. We call this a “drill induced extinction”.

As for the decision of the drilling site especially precious communities are living we have to carefully chose the site taking into account everything specially micro-topography and current system there, etc.

North Chamorro Seamount (NC SMT) The NC is also conical seamount whose shallowest peak is located at 13°56’N, 146°14’E and the depth is 3400 m. The size of the body of NS is larger than SC. The NC has an elongated shape at NW-SE direction and the slope of the SE slope is steeper than that of at NW. Slope failure and lobe structures are seen on the NW slope but on the SE slope many topographic inflection points are recognized but few slope failure.

Bluemoon Seamount (BM SMT) The BM is a rather deformed seamount whose shallowest peak lies at 15°44’N,

147°13’E and the depth is 3600 m. The eastern slope of the BM is highly deformed by the slope failure and also at the southwestern foot is deformed by the same process. The density of contour line from the shallower than 4200 m is much denser than that of the lower slope but the eastern slope shows rather gentle slope even at the shallower part.

Dive #781 was conducted at the summit area where a notable NE-SW trending fault cutting the body. The result of the dive is negative for the activity of cold seep and serpentine mud flow instead we got many dark brown semi-consolidated pelagic sediments and manganese crusts. Deformation of manganese crusts will remind us to have an active fault movement along this fault. However, R/V Thomas Thompson obtained serpentine mud sediments from somewhere of the BM therefore it is estimated that the activity of serpentine mud volcanism and cold seep did exist but already ceased long before.

Bathymetric interest of the BM is two holds; the nearest position from the trench axis, 55.6 km and deepest water depth of the surrounding forearc area, more than 5000 m.

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Peacock Seamount (PC SMT) The location of PC that has three peaks is 16°03’N, 147°07’E and the water depth is

3650 m. The PC has egg-like shape as a whole but in the northeastern foot there are many canyons and ridge structures are seen in the bathymetric map. Bathymetric interest of the PC is, also like BM, the deepest water depth of the surrounding forearc area, more than 5000 m.

Celestial Seamount (CT SMT) The CT is NNE to SSW elongated ellipsoidal shape with summit depth being 1900 m and is located at 16°32’N, 147°13’E. The northern summit area collapses largely to form caldera-like structure and debris of the failure makes a ridge structure along the northern slope. The western foot of the CT has a small depression, small knoll and canyons by unknown process makes the whole edifice to be ugly compared with the other conical seamounts. The topographic contour line is dense from the shallower part than 2600 m that indicates two stages evolution of the CT.

Dive #782 was conducted at the northern slope where a huge slope failure occurred. We landed at the thick sediment coved valley and climbed up at the summit of the CT. A notable slickenside structure was seen near the summit that shows the downward movements of mass waisting of serpentine mud flow deposits. Along the summit ridge we got several pieces of calcareous cemented hard rocks and chert. The result of the dive indicated that the activity of serpentine mud volcanism and related cold seepage has ceased before.

Turquoise Seamount (TQ SMT) The location of the summit of the Turquoise Seamount is 16°57’N, 14711’E, forming

a NNE-SSW trending small ridge at the summit. The summit of TQ is 3200 m just like CC and SC but the bottom depth is rather deep compared those of CC and SC. Whole edifice of the seamount is like a pear spreading eastward where a notable collapse and slope failure structure are seen. This seamount shows the three stages of the growth process and development of the clear canyon and horse-shoe structure at the eastern part of the edifice. The story of evolution of the seamount is the first serpentine seamount was established then the second one constructed at rather western part and the eastern part was collapsed to form notable slope failures.

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Big Blue Seamount (BB SMT) The Big Blue seamount is a complex one consisting of many small peaks of knolls

surrounding the main seamount. The location of the summit is the shallowest of all the Mariana Forearc serpentine seamount as shallow as 1232 m The shape of BB is quite irregular with notable canyons at NE and NW slopes. At least five peaks are recognized and several ranges deform the seamount shape. It seems likely to say that the geographic position of the BB is just collision part between Daton seamount chain and Mariana trench. Complex morphology may reflect such a geological situation. Dive #783 by Shinkai 6500 was conducted in order to have a reconnaissance of BB.

The dive started at the southern slope on the slope break and found an old serpentine mud flow deposits forming a small ridge which was covered with thick pelagic and/or calcareous sand and ripple marks were observed on the sediment surface . At the foot of the inflection point thick sediments of talus debris forming a talus fan. As we climbing up the southern slope many thin layers of serpentine flows are seen to form a BB body. Near the summit inclination of slope changes more gently and sediment cover is less thick compared with topographic low on the slope. Carbonate encrusted serpentine flows form a summit edifice. Two notable whitish ridges were recognized where shell fragments are scattered on the surface. Rugged surface of the summit consists of serpentine mud flow encrusted by carbonate. Many tiny shell fragments were encountered during the dive. Activity of the cold seep at the BB may ceased just before our dive because that we obtained bivalve fragment from the serpentine mud and thin cover of pelagic sediments at the summit.

Pacman Seamount (PC SMT) The PC is a queer seamount as for its shape because it happened a huge slope failure

at the eastern half of the seamount body at some time. SEABEAM bathymetric map shows a notable horse-shoe structure 10 mile long and 5 mile wide forming a depression at the foot of the eastern slope and a large swell east off the seamount. The location of the peak is 19°16’N, 146°55’E and the water depth is 2780 m by SEABEAM 2112 bathymetry. EW trending two arms are notable therefore representing U-shape with it’s mouth open to the east. Our bathymetry result indicates that a slight change of the contour density at the north and south arms which have several steps on their ranges. Alvin and Shinkai 6500 had dive to PC in 1987,1993 respectively and found a baby carbonate chimney make a line with NS direction. Especially dive #178 (Patty Fryer was an observer) showed a magnificent small chimneys with pale green stuff on their

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surface. Review observation of videos during #178 dive I found several small pock mark near the site of leave bottom on the flat sediment surface covered by pelagic mud. Many trails of sea urchin and sea cucumber and small hole may be caused by the gas bubbling were clearly seen in the video. #784 dive was conducted to confirm such a gas bubbling however it was quite hard to approach the exact the same point among a huge flat plane without any marker other than small rock pieces and gorgonians.

Conical Seamount (CC SMT) The location of the peak of CC is 19°32.5’N, 146°39’E and water depth is 3140 m by

SEABEAM bathymetry. As a short gramps it seems real conical shape but actually it is more deformed. The slope of the seamount at the eastern side is rather steeper than the western one and elongated NNE to SSW direction forming a broad lobe toward the SSW direction. The contour interval, at every 50 m interval, change its density at the water depth of 4000 m on the western slope whereas at 4400 m on the eastern slope. Therefore the shape of the cross section of the seamount has an inflection points on the E-W cross section. This means the two different history of an activity of serpentine mud flow of CC. At the summit area of CC shows irregular shape at the SW corner to have an elongated small ridge-like nose.

Many dives by US submersible Alvin and dives #179 and #785 by Shinkai 6500 show the many small ridge and trough structure that was formed by the serpentine mud flow with carbonate chimneys. During #179 dive notable elongated lobe structure which consists of fresh serpentine mud flow with boulder of peridotite blocks were observed. Many carbonate chimneys around 2 m high and several tens of cm wide stood at the summit slope of CC. One of the chimneys US team found the existence of a giant sea anemone fixed on the apex of the chimney and after 6 year later it was found again to be alive on the same chimney. During #785 we tried to find the same one, that is 17 years since the first finding but it was hard to find it. We actually found a giant sea anemone sitting on the chimney however it is hard to recognize it to be that one. The situation of carbonate chimneys were changed a little bit manganese coating on the surface of the carbonate and new white carbonate grew from the older roots but smaller than that of older one. We did not find the shimmering of any seepage at the carbonate chimney site.

Coni-Pac Triangle (CPT) The Coni-Pac Triangle (CPT) is not a serpentine seamount but mostly consisting of

serpentine mud flow deposit. It elongates NW-SE direction about 20 miles with two

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notable parallel ridges that were observed in our bathymetric map. The CPT forms really a triangle shape surrounded by Conical Seamount, CPT east wall and north wall. The deepest point of the CPT is 5800 m. The northern and eastern walls of the CPT form steep cliff having a repeated combination of a rather steep wall and a gentle slope that is composed mostly of serpentine mud flow and older semi-consolidated pelagic sediments. The outcrops of well stratified formation dipping toward the down slope that is SW direction were observed during #178 dive (Patty Fryer was an observed).

We intend to visualize the geology of the upper wall and summit of the ridge during #786 dive. We landed at water depth of 4830 m that is almost the same depth of Fryer’s last stop during the #178 dive. The slope however covered with thick pelagic sediments showing a notable ripple mark on the surface therefore it was hard to find the outcrop. Slope itself may consist of a repeated serpentine mud flow mostly buried by recent pelagic sediments and partly older semi-consolidated mudstone with manganese crust on the surface. The dip of the serpentine flow deposits was down dip toward NW to W.

About 10 pieces of rocks were collected from the slope and most of them were altered dolerite, sedimentary rocks. A few fragments of peridotite will be found from the scooped samples and serpentine mud flow deposit during the shorebased study, I hope.

Classification of serpentine seamount The results of the dive expedition of the seamounts by Alvin and Shinkai 6500 as

well as deep tow, dredge hauls from the serpentine seamount will be discussed. The seamount will divided into two major types by their morphology and geology.

1) One is non-collapse type and the other is collapse type. The former has a clear conical shape with a little deformation, whereas the latter has the notable collapse structure on its east and north slope and has an irregular shape.

2) Other classification category based on the morphology of the seamounts is the topographic inflection points. The seamount slope shows a notable inflection points on the cross section. This indicate the various stages of the activity of serpentine mud flow with pauses at sometime and some intervals. Therefore seamounts having more inflection points will be older than those having less inflection points.

3) We have to take into account the other category than seamounts themselves such as the tectonic framework around the seamount location. Pacific plate subducts under the MATS but at least five points of the surveyed area have a huge collision of seamounts and trench axis. The basement of the seamount is shallower where collision is taking place, eg. BB, PC, CT and CPT, 1460, 2780, 1900, 3160m, respectively. We also have

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to take into account the depth of the basement of the serpentine seamounts. BB and PC are located on the deep basement, more than 5000 m.

Finally, the serpentine seamounts is simply classified into two types, C and D, that is conical type and deformed type as to the activity of cold seep.

Genetic consideration of forearc serpentine seamount One thing we should take into account is the tectonic stress field of the Mariana

arc-trench system. In such a case it seems significant that several huge seamount and seamount chain collide with arc. At least five such cases are identified from the bathymetric map. At 21°30, 20°207 the extension of CC and north wall, 19°30’ east off PC, 18°30 around BB, 16° around CC.

The other thing to think about is the basement of the forearc. If we look at the bathymetric map carefully, the contour of 5000 m is concave toward the arc at around BM and 4000 m contour is concave toward arc around CT and TQ. West of BB to CPT broad forearc basin occupies east of Agurigan Island to Paganand here the outer arc high is not seen. In case of Izu-Boni ODP drilling it was clear that the outer arc high consists of boninitic andesites of the older arc, about 30 Ma, once a volcanic front.. The width of the area covered from 4000 m and 5000m contours gradually wider northward from east off Guam, widest at around BM and PC then gradually narrower to the north. The notable feature of the seamount is the shallowest part exist at BB and south of CPT forming an island-like feature

Origin and development of serpentine seamount The origin of serpentine mud flow is estimated as follows; subducting old, cold

oceanic plate yields much fluids and supplies them to the overlying forearc mantle wedge peridotite to form serpentine by the reaction under the low temperature and high pressure conditions. The density of water saturated serpentine hosted peridotite mass including volatile component started to migrate upward and yield serpentine flow deposits on the seafloor at the forearc area. The repeated accumulation of serpentine flow makes an edifice high like a strato-volcanoes. The volatile component will react and mixes with seawater at the surface condition to have a carbonate chimney or carbonate encrust.

The start of the formation of seamount is estimated just after the subduction started, may be 1 or2 million delay from the initiation of subduction. In case of MATS sometime 43 Ma or around 40 Ma the first serpentine seamount was formed. As the

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activity of the serpentine mud flow is episodic, submarine erosion takes off the soft fragile serpentine sediments and makes a flat top. Then second activity will make a new edifice on the old basement and forms inflection point on the bathymetric map. Fault movement and possible explosion of gas yield the slope failure with huge mass wasting on the seamount edifice to form irregular ridge and trough structure, and subsequent erosion will make a notable canyon structure on the surface. If the duration of the inactive or non-active term is long, manganese oxides coats the surface of the flow and carbonate chimneys. As for the origin of volatile component it is estimated that the carbon from the dead planktons buried into pelagic sediments, hydrogen from the result of the reaction of serpentinization, fluids from the sediments and rocks of subductiong lithospere and mantle origin gas will be mixed up.

During ascent of water saturated serpentine mud surrounding rocks pre-existing beneath the forearc, such as sedimentary rocks, gabbros, basalts if they were there will be captured in the serpentine flow as xenoliths. The microbe will be also captured into the serpentine mud. Therefore we can estimate the lower limit of the living microbe under the forearc, that is the lower limit of deep biosphere by an elaborated microbiological study of serpentine mud. Careful analyses of mineral assemblages of metamorphic rocks from the serpentine mud will sheds light to the depth and thermal information from where the serpentine mud formed.

In situ measurement using StrataBox, and three-component magnetometer

Subbottom profiling using StrataBox was performed for 7dives in various setting of parameter or power connection. StrataBox is personal computer based subbottom profiling system and we got clear image of subbottom structure when submersible run more than 2m above the sea bottom. The record in original format is 200 x 7bit for each scan, meaning rough sampling and nallow dynamic range. Once record is taken, it’s difficult to reconstruct the data by post-processing. We must select best condition and setting of parameters. For power connection, there are 3 available ways, submersible’s ordinary 28V DC power, submersible’s accurate 28V DC power and 12 V drifit-type battery. For parameter setting, there are auto-all mode and manual setting. In manual setting mode there are 3 parameters, DC gain, BT gain and range. We select DC gain as 20db, BT gain as 0db and 0.4db/m, range as 40m, 20m and 10m. We could not

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test all kinds of setting, but got valuable information for next trial.Setting for each dive is as follows,#778 : ordinary 28V DC, auto all mode#779 : ordinary 28V DC, manual setting (DC gain: 20db, BT gain: 0.4db/m, range: 40m)#780 : ordinary 28V DC, manual setting (DC gain: 20db, BT gain: 0db/m, range: 40m)#781 : ordinary 28V DC, manual setting (DC gain: 20db, BT gain: 0db/m, range: 10m)#783 : ordinary 28V DC, manual setting (DC gain: 20db, BT gain: 0.4db/m, range: 40mand 20m)#784 : ordinary 28V DC, manual setting (DC gain: 20db, BT gain: 0.4db/m, range:10m)#785 : accurate 28V DC, manual setting (DC gain: 20db, BT gain: 0.4db/m, range:40m)Finally we could not test 12V drifit-type battery due to our short preparation.Considering all these results, we decided the best power connection and parametersettings as follows;Ordinary 28V DC power, manual setting (DC gain: 20db, BT gain 0.4db/m, range: 20m)But, 12 V drifit-type batteries should be tested for better record.For example, hardcopies of 1 minute record are shown in Fig.1 to 7.

Thin transparent sedimentary layer, less than 1m, exists in some places. There are so many scattered balls like structures in subbottom image. Their sizes are calculated to be several ten cm if submersible run at 0.5 knot/hour. The image might suggest underground large rock blocks.

Fig.1 1minute 13 second record of Dive #778. Record runs from left to right. If submersible runs at 0.5 knot/hour full horizontal width of the image indicates approximately 18 m. Right end indicates 2003/09/02, 11:39 for local Guam time. Vertical range is 10m.

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Fig.2 Example record of Dive #779. Right end time is 15:08:41. Vertical range is 40m. Other explanation is same as Fig.1

Fig.3 Dive #780. Right end time is 15: 59:07. Vertical range is 40m. Other explanation is same as Fig.1

Fig.4 Dive #781. Right end time is 14:29:02. Vertical range is 10m. Other explanation is same as Fig.1

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Post-processing of StrataBox image data is useful to treat longer interval of data than 1min 13second. StrataBox data is modified to treat in Photoshop software, and then change the vertical ratio of image. 3 examples of approximately 10 minute record of Dive #783 are shown in Fig.8.

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Fig.8 Three examples of StrataBox record treated in Photoshop.

Submersible’s depth is recorded in CTD data in high resolution format. We can correct the StrtaBox image to true topographic one using CDT data. Fig.9 is the result of this calculation, also shown by Photoshop software.

Fig.9 Depth corrected StrataBox image. Submersible runs from left to right.

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DSTCM（ Deep Sea Three Component Magnetometer） was used for 6 dives. Due to the malfunction of some equipment at most 2 components were recorded for all data. Submersible’s orientation data recorded in DSTCM is no-use due to malfunction of AD converter. We can show 2 components during dives. Fig.10 indicates some part of X, Y component records in dive #784.

Fig.10 2 components of DSTCM recorded in dive #783. Vertical record didn’t work.

Geophysics

Gravity meter record of this cruise jumped so many times and looks like very difficult to reconstruct their continuity. Just after the departure from JAMSTEC port the relative value is approximately 10000 mgal, then decreased to 8000 mgal, which is reasonable due to low latitude. Aug. 23rd the value jumped up to 15000 mgal and at Guam port the value is 35000 mgal. Finally it reached 70000 mgal. We might reconstruct relative gravity values from rather stable parts of data using suitable shift of values among these parts. Furthermore recording function of system stopped from midst of the cruise, Sept. 6. Fig.1 is the example of Aug. 23rd’s data.

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Proton precession magnetometer was used from Sept. 3rd to Sept. 15th. Sometimes the result is very noisy and it needs much time to fix the data. Fig.2 shows Sept. 5th record.

STCM (Shipboard Three Component Magnetometer) have worked well during the cruise. Double circle running (8 figure loop) for calibration constants were done 2 times at Sept.2nd and Sept.15th. Calibration constants calculated these data were summarized in Table.1.

Table.1 Calibration constants for STCM ―――――――――――――――――――――――――――――――――――

―――

Date 9/1/2003 9/15/2003 yk0307c1c2 Start TIME 08:55 21:40 End TIME 09:23 22:10 Latitude 13°39.6‘ N 19°39‘ N

Longitude 145°54.5‘ E 146°20‘ E B(1,1)= 1.08525 1.08011 1.08204

B(1,2)= 0.04832 0.0427 0.05051

B(1,3)= 0.04307 -0.12404 0.00391

B(2,1)= -0.02861 -0.04191 -0.03577

B(2,2)= 1.20068 1.1688 1.21511

B(2,3)= -0.05971 -0.26358 0.06387

B(3,1)= -0.0009 -0.00323 -0.00268

B(3,2)= 0.06151 0.06509 0.12632

B(3,3)= 0.42724 0.46115 0.90530

Hp1= -2195.1 1391.3 -1573.2

Hp2= 5687.5 11311.2 3901.1

Hp3= 1887.8 4981.8 -5052.0

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―――――――――――――――――――――――――――――――――――

2 character 8 loops are shown in Fig.3 and 4.

Fig.3 Ship’s track of YOKOSUKA at first chr8 loop, 2003/9/1.

Fig.4 Ship’s track of YOKOSUKA at 2nd chr8 loop, 2003/.9/15.

Every 1minute records were calculated using the calibration constants in Table.1. Fig.5 to 7 illustrates the total magnetic anomaly from STCM data with least square method for every track line.

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Fig.5 Profiles of total magnetic anomaly of STCM data.

Fig.6 Profiles of total magnetic anomaly of STCM data.

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Fig.7 Profiles of total magnetic anomaly calculated from STCM data.

These data indicate rather small magnetic anomaly around the seamounts targeted here, approximately 100 nT (P-P). Future studies using DSTCM and magnetic intensity data from rock samples are important to reconstruct true magnetic structure of these seamounts.

PETROLOGY

During Dive #778 to #786, about eighty rocks were recovered. They are mainly untramafic rocks. Carbonate rock, mudstone and metamorphosed basalt to dolerite are subordinate. Ultramafic rocks are mostly or completely serpentinized, but pyroxene bastite is ubiquitous. It is noteworthy that ultramafic rocks of Celestial Seamount are rich in pyroxene. Ultramafic rocks recovered from Big Blue Seamount has less alternated by sea water. It may suggest that Big Blue Seamount is relatively young serpentinite seamount. Rocks recovered from Coni-Pac Triangle contains metamorphosed igneous rocks. Microscopic observation is necessary to determine mineral assemblages and metamorphic conditions. Rocks obtained from each dive are as follows;

Dive #778 (Chamorro Seamount) Ultramafic rocks were partly or completely serpentinized. Olivine and orthopyroxene

are partly retained in some of ultramafic rocks. They are serpentinized dunite and harzburgite. Orthopyroxene bastite is commonly visible. Two white colored carbonate

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rocks are also recovered.

Dive #779 (Chamorro Seamount) Seven ultramafic rocks and five carbonate rocks were recovered. The ultramafic

rocks are dunite and harzburgite and highly serpentinized. One carbonate rock (#779-R-09-1) contains shells.

Dive #780 (Chamorro Seamount) Three ultramafic blocks were recovered. One has primary olivine and pyroxene

crystals and two are wholly serpentinized. The former contains orthopyroxene bastite, and is estimated harzburgite origin.

Dive #781 (Bluemoon Seamount) All the rocks recovered are semi-consolidated brown mudstone. Some have clear

alternated laminae of silt and clay. These rocks are considered to be parts of thick sedimentary layers which cover old serpentinite seamount.

Dive #782 (Celestial Seamount) Ultramafic rocks and Carbonate rocks were recovered. Ultramafic rocks are mostly

serpentinized. Because the ultramafic rocks characteristically contain abundant pyroxene bastite, they are olivine pyroxenite or websterite. Carbonate rocks are white in color. Some has gray-colored siliceous core.

Dive #783 (Big Blue Seamount) Seventeen ultramafic rocks were recovered. They are highly serpentinized, but

pyroxene bastite is frequently recognized. Similar to the Celestial Seamount, some contains abundant pyroxene bastite. Although most of ultramafic rocks were highly serpentinized, the thickness of brownish clayey cover around each block is less than one centimeter. It suggests that the Big Blue Seamount erupted just recently and rocks of surface were less altered by sea water.

Dive #784 (Pacman Seamount) The rocks recovered from Dive #784 are carbonate rocks. They are white in color.

Some of them are part of chimney and fragile.

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Dive #785 (Conical Seamount) No rock was recovered.

Dive #786 (Coni-Pac Triangle) Metadolerite - metagabbro, vesicular meta-volcanic rock, mudstone, and

reddish-brown colored rocks were recovered. Metadolerite - metagabbro is dark green in color, and medium to coarse grained. Vesicular meta-volcanic rock is greenish gray. It possibly was originated from boninite. Two reddish-brown colored rocks were obtained. These rocks have equigranular texture, and were possibly peridotite or (sedimentary?) gabbro. Further exact study using polarized microscopy is necessary to determine rock type. Milimetric fragments of serpentinite were also found in semi-consolidated mud from Dive #786.

BIOLOGY

A p r o v is io n a l id e n t if ic a t io n o f a liv e b e n t h o s c o lle c t e d d u r in g t h e YK 0 3 - 0 7

D ive N o . C o m m m o n n a m e I d e n t if ic a t io n 7 7 3 C la m C a l y p t o g e n a sp . 1

Tu b e wo r m L ame l l i b r a c h i a sp . S h r im p M u n id o p s is m a r ia n ic a

7 7 4 S h r im p C h o r o c a r is va n d o ve r a e M u sse l B a t h ym o d io lu s b r e v io r

7 7 5 B a r n a c le - like U n id e n t if ie d 7 7 7 C la m C a l y p t o g e n a sp . 2

M u sse l B a t h ym o d io lu s e lo n g a t u s 7 7 8 M u sse l d it t o 7 7 9 C la m C a l y p t o g e n a sp .2

M u sse l B a t h ym o d io lu s e lo n g a t u s 7 8 0 C la m C a l y p t o g e n a sp .2

Description of sample materials collected during the YK03-07 cruise Leg 1 and 2 and the prompt analytical strategy on land-based laboratory is given in Table 1. Results will be published on relevant journals.

A comparison of major chemo-synthesis based biological community among five

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areas is summarized in Table and Fig. It is clear that the major benthos composition is very variable, indicating unique faunal composition within a given area. Such geographic discrimination would relate to flux of hydrogen sulfide together with methane in issuing fluids which is verified by analysis in land-based laboratory.

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VI. SHORE BASE STUDY

GEOCHEMISTRY

Ms. A.Kosaka (Hokkaido Univ.) During the cruse, I have gas samples collected by WHATS, seawater and pore

water samples. These samples would be subjected to analysis for isotope ratio. Stable carbon isotope ratio(δ13C) of CH4, CO2 and CO will be measured by GC/C/IRMS system at Hokkaido University. The concentration of these gases could be calculated from peak area of the MS detectors. Some portion of these samples will be analysis for H2. Chemical character of the Mariana forearc site compared to another field in the world will be discussed.

Dr. Hitoshi Chiba (ISEI, Okayama University) 1) H. Chiba, H. Maekawa, Y. Ohara, and Fujioka: Oxygen and hydrogen isotopic

behavior on serpentinization of peridotite at Mariana Fore-arc Seamount. After petrologic description about metamorphism and alteration of rock samples, I

will measure representative rock samples for oxygen and hydrogen isotopic ratios. Measurement will be done for subsampes of various degrees of metamorphism and alteration as well as a fresh core. The results will show a general stable isotopic trend during serpentinization reaction. The temperature of serpentinization process may be estimated using available stable isotope geothermometer.

2) H. Chiba: Pore water chemical composition of Mariana Fore-arc Seamount (Data Report)

The pore water samples collected during the cruise will be measure for their major chemical compositions. The data will be reported as a data report in JAMSTEC J. Deep Sea Res.

MICROBIOLOGY

Drs. K. Takai, H. Hirayama, Y. Suzuki and T. Nakagawa (JAMSTEC)

During this cruise, we have succeeded in collecting good samples, especially

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from the TOTO caldera deep-sea hydrothermal field. The finding elemental sulfur chimney appeared to be the first case so far and an extremely acidic hydrothermal fluid will provide an excellent opportunity to study about extremely acidophilic, hyperthermophilic microbial communities in the deep-sea hydrothermal systems.

By analyzing the high quality samples we obtained in this cruise, we intend to investigate the microbial diversity and distribution by the combination of culture-dependent and culture-independent molecular ecological study. Furthermore, microbiological data will be coupled to geochemical, geophysical and geological data and show us the position of microbes in geochemical cycling or flow in hydrothermal vents in the TOTO caldera and serpentine mud seepages in the Mariana Forearc Seamounts.

Culture-dependent ecological surveys Microbiologist often said that culturable microbes are only 0.1 to 1% in natural

environment, and culture–independent molecular ecological surveys have been very popular and indispensable tools for microbial ecologist. However, it is very difficult to show the direct evidence of metabolism and physiology of microorganisms and culture-independent analyses are still important and effective tools in microbial ecology. Furthermore, coupling the information of culture-independent molecular ecological, geochemical and geophysical analyses provide the effective data for cultivation of previously uncultured organisms. In fact, our group has been tried to cultivate previously uncultured organisms with the information of geochemical investigation in hydrothermal vents in Indian Ocean, Iheya ridge and Hishikari gold mine and has succeeded in cultivation of more than 10% of the members in each habitat.

In this survey, we will evaluate the predicted members of microorganisms in hydrothermal vent and cold seep site by MPN method. In addition, we will explore the novel microbial resources for industry or

MPN analysis Serial-dilution [Most Probable Number (MPN) cultivation experiments were

performed to enumerate organisms whose metabolism are correspond to the condition of medium. Homogenized sediment slurries were diluted in 10-fold steps into liquid media, which should support the growth and putative population of specific physiological types of microorganisms. The microorganisms in the highest dilutions with positive growth are possibly dominant species in the cultured condition. This

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approach is applied to the predictable members in each environment.

Culture –independent molecular ecological surveys Culture–independent molecular ecological surveys produce high resolution

mapping of diversity and distribution of microorganisms. Most of the previous molecular ecological study were based on genome DNA but DNA based analyses could not reflect the activity of microbes. Sometimes, some of the detected clones were not from active microbe but from sedimented paleobe in the sediment samples. Thus, in this survey, we will use RNA based molecular biological technique that reflects the activity of the cell. RNA based culture-independent analysis will more contribute to understanding the microbial effect in geochemical cycles than DNA based analysis.

Evaluation of biomass: In order to evaluate the population and distribution of microbial components, we will evaluate total microbial density by direct counting of DAPI or AO stained cells.

c-DNA is synthesized from purified RNA by reverse transcriptase using gene specific oligonucleotide or random hexamer as a primer.

T-RFLP (Terminal Restriction Fragment Length Polymorphism) allows identification of PCR products based on length variations after restriction endonuclease digest. In the amplification of gene fragment, one of the primer oligonucleotide is labeled by fluorescent material like Fam.

DGGE (Denaturing Gradient Gel Electrophoresis) and TGGE (Temperature Gradient Gel Electrophoresis) are gel-electrophoresis methods that separate mixed PCR products in denaturing polyacrylamide gradients, based on melting domain structure of the DNA double strand (Muyzer and Smalla 1998). Bands appearing on the gel are extracted and sequenced for a phylogenetic identification.

Quantitative PCR, a modification of two-step PCR, is essentially a fluorescens assay used to quantify the number of target genes in an environmental sample (Takai and Horikoshi 2000). In the analysis based on 16S rDNA, we will study the population ratio between the domain Bacteria and Archaea using the specific probe for each domain. In addition, we also quantify the amount of functional genes as DNA or c-DNA as template by gene specific primers.

Gene sequencing is necessary process to obtain the primary information of the gene sequence itself that is essential for all phylogenetic analysis and identification of

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microorganisms. We will construct clone libraries for target genes (e.g. 16S rDNA, Methyl CoM reductase, dissimilatory sulfite reductase etc.) with each subsamples and compare each libraries associated with geochemical and geological data.

FISH (Fluorescence In Situ Hybridization) analysis is the microscopic observation of the cells that rRNA was hybridized with the specific fluorescence probes designed based on the variability of 16S rRNA sequence. Thus, this technique visualizes the results of clone analysis based on 16S rDNA. Furthermore, if we use two or more probes for hybridization, we may observe the consortium of microorganisms like the anaerobic methane oxidizing consortium between anaerobic methane oxidizing archaea and sulfate reducing bacteria.

BIOLOGY

Dr. Chitoshi Mizota・ Sulfur isotopic characterization of sulfides in sediments just beneath the

chemo-synthesis based biological community which collaborates with H. Chiba (Okayama Univ.)

・ Taxonomic and geographic studies on the chemo-synthesis based animal community which collaborates with Y. Fujiwara (JAMSTEC), T. Okutani (JAMSTEC) and S. Kojima (ORI, Univ. Tokyo))・ Carbon, nitrogen and sulfur isotopic characterization of soft body parts of

chemo-synthesis based biological community which collaborates with T. Yamanaka (Kyushu Univ.)

・ Oxygen and hydrogen isotopic constraints to formation temperature as estimated by serpentine-magnetite geo-thermometry which collaborates with H. Chiba (Okayama Univ.)

GEOLOGY, GEOPHYSICS & GEOCHEMISTRY (PETROLOGY)

Future studies of Geology, Geophysics and Geochemistry

1. Oral presentations (possible)JAMSTEC symposium (General results of G & G including all the participants)Japanese Geophysical Union (Godo-gakkai)Geologicla Soceity of Japan Ann. Mtg

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AGU 2004

2. Summary papersCruise summary to InterMargin (Including all the participants)JAMSTEC DSR paper (Including all the participants)

3. Research papers1. Chamorro SeamountDrill induces extinction of chemosysthetic community (in preparation)Fujioka, K., Chiba, H., Takai , K., Suzukui, Y., (Nature)We intend to write up a short paper on the possible drilling mud flood buriedchemosynthetic community based on the time series and spatial observation of the clam community of the South Chamorro Seamount.

Comparative serpentinology study 2. Origin and development of the Mariana forearc serpentine seamounts Fujioka, K., Maekawa, H., Chiba, H., Takai, K., Suzuki, Y., Hirayama, H., Mizota, C., Ishii, R., Kato, K., Sakaguchi, M. (GEOLOGY or GRL) Description of each serpentine seamount based on the topography, dive geology petrology and geochemistry data to establish a model for the formation of serpentine seamount

Geology and geophysics of the Mariana forearc 3. Topography and geophysical features of the Mariana forearc Fujioka, K., Joushima, M., Ishii, R. (JGR) Compilation of bathymetric, geomagnetic and gravity data

4. Tectonic framework and evolution of Mariana arc-trench system K. Fujioka (Tectonophysics) Compilation of all the DSDP/ODP data, dive results and piston coring, dredge hauls data proposal of a serpentine dominated tectonics along the western Pacific

5. Magnetic properties of the Mariana forearc serpentine seamount Joushima, M., Kido, Y., and Fujioka, K. (GRL) Model for an origin of magnetic anomalies observed along the Mariana forearc by

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three-component and proton magnetometer as well as intensity and susceptibility from the discrete samples

6. Metamorphic evolution beneath the Mariana forearc, western PacificMaekawa, H., Sakaguchi, M., and Fujioka, K., (possible addition of Maekawa’sstudents names)(J. Metamorph. Geol)

7. Oceanfloor metamorphism and thermal structure of the of the ocean crust and uppermantle in the Mariana forearcSakaguchi, M., Maekawa, H., Ishizuka, H., and Fujioka, K (J. Metamorph. Geol)

8. Temperature and pressure estimation of the formation of serpentine mud flow byoxygen isotope and petrologic data of the Mariana forearc serpentine seamount (Chem.Geol.)Chiba, H., Ohara, Y., Maekawa, H., and Fujioka, K.,

Ultramafic and related rocks 7. Mantle compositional variations beneath the Mariana forearc: implications forlithospheric processes in mantle wedge. (J. Petrol. or Chem. Geol)Ohara, Y., Fujioka, K., Snow, J. and Ishii, T .Using peridotites, gabbros and other rocks to estimate the variation of mantle wedgecompositional chain.

Nakagawa, M. will have a crystallographic analyses of serpentine minerals of the sediments obtained from Mariana forearc but I don’t know he will write a paper

Matsuoka, H., will have an elaborated nannofossil biostratigraphic analyses of the sediments from Mariana forearc but I don’t know she will write a paper

Matsuoka, A. will have an elaborated radiolarians biostratigraphic analyses of the sediments from Mariana forearc but I don’t know he will write a paper

Ishii, K., Maekawa, H. et al Ductile deformation under upper mantle condition deduced from the peridotite xenolith from the Mariana forearc serpentine seamount

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M. Joshima, K. Nishimura, Oyagi, K. Fijioka Sub-bottom structure of seamounts in the Mariana outer arc area using sub-bottom profiling equipment, StrataBox.

Future study (Kazuhiro Kato, Faculty of Science, Shizuoka University)

Title Isotopic study of carbonate deposits to identify mixing ratio of seawater and cold seepage and estimation of formation process.

Co-worker H. Wada (Shizuoka Univ., δ13C & δ18O), H. Matsuzaki (University of Tokyo, ∆14C), K. Ohseto (Japan National Oil Corporation, X-ray CT Scan)

Many isotopic studies were carried out using the carbonate deposits associated with the cold seepage and these carbonate deposits result from the mixing fluid of seawater and cold seepage. However, quantitative estimation of mixing ratio between the seawater and cold seepage during carbonate precipitation have not been studied from the isotopic study of carbonates. Therefore, objective of my future study is isotopic analyses (mainly δ13C, δ18O and ∆14C) to identify mixing ratio of seawater and cold seepage and precipitation process using the carbonate deposits and bottom seawater samples (Niskin sample) collected from the South Chamorro Seamount (Dive #778, Dive #779), Pacman Seamount (Dive #784) and Conical Seamount (Dive #785).

Hitoshi Chiba (ISEI, Okayama University) 3) H. Chiba, H. Maekawa, Y. Ohara, and Fujioka: Oxygen and hydrogen isotopic

behavior on serpentinization of peridotite at Mariana Fore-arc Seamount. After petrologic description about metamorphism and alteration of rock samples, I

will measure representative rock samples for oxygen and hydrogen isotopic ratios. Measurement will be done for subsampes of various degrees of metamorphism and alteration as well as a fresh core. The results will show a general stable isotopic trend during serpentinization reaction. The temperature of serpentinization process may be estimated using available stable isotope geothermometer.

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4) H. Chiba: Pore water chemical composition of Mariana Fore-arc Seamount (Data Report)

The pore water samples collected during the cruise will be measure for their major chemical compositions. The data will be published as a data report in JAMSTEC J. Deep Sea Res.

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VII. APENDIX

Sample list for Microbiology, Biology and Geochemistry Sample enumeration of YK03-07, Leg 1 (ToTo Caldera Nakayama field)

Date Dive No. Sample category Position Depth (m) Temp. ( ) Sample descrip tion Volume Investigation Distribution Remarks Aug. 23.03 #772

Rock 12-42.801N, 143-32.398E 2922 Igneous rock with surface sulfur x1 DNA,RNA,CLT,BM JAMSTEC (#63 marker)

Sediment 12-42.673N, 143-32.398E 3060 772M Y-1 0-5 cm PW, GAS Hokudai 772M Y-2 5-10 cm DNA,RNA,CLT,PW, BM, Gas JAMSTEC

12-42.673N, 143-32.398E 3060 772M Y-1 0-5 cm PW, GAS Hokudai 772M Y-2 5-10 cm DNA,RNA,CLT,BM JAMSTEC 772M Y-3 10-15 cm PW, GAS Hokudai 772M Y-4 15-20 cm DNA,RNA,CLT,PW, BM, Gas JAMSTEC 772M Y-5 20-25cm PW, GAS Hokudai 772M Y-6 25-30 cm DNA,RNA,CLT,PW, BM, Gas JAMSTEC

Water WHATS(each 150ml;for liquid) 12-42.8139N, 143-32.330E 2927 20 C 772W-1 150 ml PW, Gas, DNA, CLT, FISH Hokudai (90 ml), JAMSTEC(60 ml) 12-42.8139N, 143-32.330E 2921 20 C 772W-2 150 ml PW, Gas, DNA, CLT, FISH Hokudai (90 ml), JAMSTEC(61 ml) 12-42.801N, 143-32.398E 2922 58-75 C 772W-3 150 ml PW, Gas, DNA, CLT, FISH Hokudai (90 ml), JAMSTEC(62 ml) 12-42.801N, 143-32.398E 2921 60 C 772W-4 150 ml PW, Gas, DNA, CLT, FISH Hokudai (90 ml), JAMSTEC(63 ml)

Niskin bottle 12-42.8691N, 143-32.234E 2964 (-7) 772N1 (White) 2L DNA,FISH,CLT,PW,Gas JAMSTEC(1.8 L), Hokudai (0.2 L) 12-42.8231N, 143-32.322E 2923 772N2 (Red) 2L DNA,FISH,CLT,PW,Gas JAMSTEC(1.8 L), Hokudai (0.2 L) Above tube worm

12-42.801N, 143-32.398E 2922 Pump sample (772PS) 20 L JAMSTEC(rest), Hokudai (0.1 L)

Aug. 24.03 #773 Rock 12-42.746N, 143-32.335E 2935 Chimney-core x1 DNA,RNA,CLT,BM JAMSTEC

12-42.746N, 143-32.335E 2935 Chimney-middle x1 DNA,RNA,CLT,BM JAMSTEC 12-42.746N, 143-32.335E 2935 Chimeny-surface x1 DNA,RNA,CLT,BM JAMSTEC

Marker #73 Water WHATS(each 150ml;for liquid)

12-42.737N, 143-32.334E 2949 96 C 773W-1 150 ml PW, Gas, DNA, CLT, FISH Hokudai 12-42.737N, 143-32.334E 2949 97 C 773W-2 150 ml PW, Gas, DNA, CLT, FISH Jamstec 12-42.737N, 143-32.334E 2947 102 C 773W-3 150 ml PW, Gas, DNA, CLT, FISH Hokudai 12-42.737N, 143-32.334E 2947 102 C 773W-4 150 ml PW, Gas, DNA, CLT, FISH Jamstec

Niskin bottle 12-42.652N, 143-32.382E 2589 773N1 (Red) 2L DNA,FISH,CLT,PW,Gas JAMSTEC(1.8 L), Hokudai (0.2 L) 12-42.652N, 143-32.382E 2840 773N2 (White) 2L DNA,FISH,CLT,PW,Gas JAMSTEC(1.8 L), Hokudai (0.2 L) Above tube worm

12-42.749N, 143-32.311E 2948 Pump sample (773PS) 20 L JAMSTEC(rest), Hokudai (0.1 L)

Organism 12-42.711N, 143-32.329E 2973 Clams 4 DNA, FISH, EM JAMSTEC, Iwate Univ preserved in 3.7% formardehyde 12-42.746N, 143-32.335E 2937 Tube worm 10 DNA, FISH, EM JAMSTEC, Iwate Univ preserved in 3.7% formardehyde 12-42.746N, 143-32.335E 2937 Shrimp 5 DNA, FISH, EM JAMSTEC preserved in 3.7% formardehyde

Aug. 25.03 #774 Rock 12-42.324N, 143-32.337E 2952 Chimney x1 DNA,RNA,CLT,BM JAMSTEC

Water WHATS(each 150ml;for liquid) 12-42.734N, 143-32.355E 2965 78-81 C 774W-1 150 ml PW, Gas, DNA, CLT, FISH Hokudai (90 ml), JAMSTEC(60 ml) 78-81 C 12-42.734N, 143-32.355E 2965 84-87 C (1910 ml total) 774W-2 150 ml PW, Gas, DNA, CLT, FISH Hokudai (90 ml), JAMSTEC(61 ml) 84-87 C (1910 ml total) 12-42.734N, 143-32.343E 2951 87-95 C(1165 ml) 774W-3 150 ml PW, Gas, DNA, CLT, FISH Hokudai (90 ml), JAMSTEC(62 ml) 87-95 C(1165 ml) 12-42.734N, 143-32.343E 2951 87-100 C avg. 92 C 774W-4 150 ml PW, Gas, DNA, CLT, FISH Hokudai (90 ml), JAMSTEC(63 ml) 87-100 C avg. 92 C

Niskin bottle 12-42.705N, 143-32.227E 2000 774N1 (Red) 2L DNA,FISH,CLT,PW,Gas JAMSTEC(1.8 L), Hokudai (0.2 L) 12-42.734N, 143-32.343E 2840 774N2 (White) 2L DNA,FISH,CLT,PW,Gas JAMSTEC(1.8 L), Hokudai (0.2 L) Above tube worm

12-42.734N, 143-32.342E 2948 Pump sample (774PS) 20 L DNA,FISH,CLT,PW,Gas JAMSTEC(rest), Hokudai (0.1 L)

Organism 12-42.734N, 143-32.332E 2945 musse ls 2 DNA, FISH, EM JAMSTEC preserved in 3.7% formardehyde

Aug. 26.03 #775 Rock 12-42.770N, 143-32.344E 2936 White smoker rock x1 DNA,RNA,CLT,BM JAMSTEC

Water WHATS(each 150ml;for liquid) 12-42.770N, 143-32.344E 2936 113-122 C (Max 170 C) 775W-1 150 ml PW, Gas, DNA, CLT, FISH Hokudai (90 ml), JAMSTEC(60 ml) 12-42.770N, 143-32.344E 2936 94-123 C 775W-2 150 ml PW, Gas, DNA, CLT, FISH Hokudai (90 ml), JAMSTEC(60 ml)

Niskin bottle 12-42.698N, 143-32.231E 1000 775N1 (Red) 2L DNA,FISH,CLT,PW,Gas JAMSTEC(1.8 L), Hokudai (0.2 L)

12-42.770N, 143-32.344E 2936 Pump sample (775PS) 2L DNA,FISH,CLT,PW,Gas JAMSTEC(rest), Hokudai (0.1 L)

Organism 12-42.780N, 143-32.342E 2927 bar nac le - like o r ganism 5 DNA, FISH, EM JAMSTEC preserved in 3.7% formardehyde

Aug. 27.03 #776

Water WHATS(each 150ml;for liquid) 12-42.774N, 143-32.345E 2934 38-70 C 776W-1 150 ml PW, Gas Hokudai 12-42.774N, 143-32.345E 2934 47-69 C 776W-2 150 ml PW, DNA, CLT, FISH JAMSTEC

2934 114-129 (Max 140) 776W-3 150 ml PW, DNA, CLT, FISH JAMSTE

Niskin bottle 12-42.774N, 143-32.345E 2934 776N1 (White) 2L DNA,FISH,CLT,PW,Gas JAMSTEC(1.8 L), Hokudai (0.2 L) Ambient bottom water

ISCS 12-42.771N, 143-32.330E 2924 ISCS-2 DNA,FISH,CLT JAMSTEC 20-70 C (Tubeworm site) for four days 12-42.723N, 143-32.326E 2945 ISCS-1 DNA,FISH,CLT JAMSTEC 108 C (sulfur chimney site) for three days

Aug. 28.03 #777 Rock 13-46.936N, 146-0.250E 2899 carbonate crust-white x1 DNA,RNA,CLT,BM JAMSTEC Small

13-46.936N, 146-0.250E 2899 carbonate crust-black x1 DNA,RNA,CLT,BM JAMSTEC Small 13-46.936N, 146-0.250E 2899 carbonate crust-black x1 DNA,RNA,CLT,BM JAMSTEC large

Sediment 13-46.936N, 146-0.250E 2931 777M Y-1 0-5 cm PW, GAS Hokudai 777M Y-2 5-10 cm DNA,RNA,CLT,PW, BM, Gas JAMSTEC

13-46.987N, 146-0.420E 2931 777M G-1 0-5 cm PW, GAS Hokudai 777M G-2 5-10 cm DNA,RNA,CLT,BM JAMSTEC 777M G-3 10-15 cm PW, GAS Hokudai 777M G-4 15-20 cm DNA,RNA,CLT,PW, BM, Gas JAMSTEC

Water WHATS(each 150ml;for liquid) 13-46.936N, 146-0.250E 2899 777W-1 150 ml PW, Gas, DNA, CLT, FISH Hokudai (120 ml), JAMSTEC(30 ml) From main fault 13-46.936N, 146-0.250E 2899 777W-2 150 ml PW, Gas, DNA, CLT, FISH Hokudai (120 ml), JAMSTEC(30 ml) From main fault 13-46.936N, 146-0.250E 2899 777W-3 150 ml PW, Gas, DNA, CLT, FISH Hokudai (120 ml), JAMSTEC(30 ml) From small fault 13-46.936N, 146-0.250E 2899 777W-4 150 ml PW, Gas, DNA, CLT, FISH Hokudai (120 ml), JAMSTEC(30 ml) From small fault

Niskin bottle 13-46.988N, 146-0.486E 29?? 777N1 (White) 2L DNA,FISH,CLT,PW,Gas JAMSTEC(1.8 L), Hokudai (0.2 L) ambient bottom water 13-46.936N, 146-0.250E 2899 777N2 (Red) 2L DNA,FISH,CLT,PW,Gas JAMSTEC(1.8 L), Hokudai (0.2 L) Cold seep

Organism 13-46.936N, 146-0.250E 2899 Calyptogena x1 DNA, FISH, EM JAMSTEC, Iwate Univ preserved in 3.7% formardehyde 13-46.936N, 146-0.250E 2899 Bathymodiolus x2 DNA, FISH, EM JAMSTEC, Iwate Univ preserved in 3.7% formardehyde

Abbreviations: PW, pore water chemistry; CLT, microbial cultivation; BM, biomarke; FISH, fluorescence in-situ hybridization

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Sample enumeration of YK03-07, Leg 2 (S erpentine S eamounts)

Date Dive No. Sample category Position Depth (m) Temp. ( ) Samp le descrip tion Volume Investigation Distribution Remarks Sep. 02.03 #778

Rock 13-47.003N, 146-0.185E 2905 carbonate crust-white x1 DNA,RNA,CLT,BM JAM STEC & Geologists (see another table) 13-47.003N, 146-0.185E 2905 carbonate crust-black x1 DNA,RNA,CLT,BM JAM STEC & Geologists (see another table) 13-47.003N, 146-0.185E 2905 serpentine rock x2 Geologists (see another table)

Sediment 13-47.003N, 146-0.185E 2905 778M G-1 0-5 cm DNA,RNA,CLT,BM JAM STEC

13-47.003N, 146-0.185E 2905 778M W-1 0-5 cm PW, GAS Hokudai 778M W-2 5-10 cm PW, GAS Hokudai

13-47.003N, 146-0.185E 2905 778C-1 0-5 cm DNA,RNA,CLT,BM JAM STEC

Water WHATS(each 150ml;for liquid) 13-47.003N, 146-0.185E 2905 778W-1 150 ml PW, Gas, DNA, CLT, FISH Hokudai (150 ml) From dead colony 13-47.003N, 146-0.185E 2905 778W-2 150 ml PW, Gas, DNA, CLT, FISH Hokudai (120 ml), JAM STEC(30 ml) From dead colony 13-47.003N, 146-0.185E 2905 778W-3 150 ml PW, Gas, DNA, CLT, FISH Hokudai (150 ml) From alive colony 13-47.003N, 146-0.185E 2905 778W-4 150 ml PW, Gas, DNA, CLT, FISH Hokudai (120 ml), JAM STEC(30 ml) From alive colony

Niskin bottle 13-47.003N, 146-0.185E 2905 778N1 (White) 2L DNA,FISH,CLT,PW,Gas JAM STEC(1.8 L), Hokudai (0.2 L) ambient bottom water 13-47.003N, 146-0.185E 2905 778N2 (Red) 2L DNA,FISH,CLT,PW,Gas JAM STEC(1.8 L) Cold seep

Organism 13-47.003N, 146-0.185E 2905 Bathymodiolus x4 DNA, FISH, EM, Isotope JAM STE, Iwate Univ. preserved in 3.7% formardehyde Snail sx1 DNA, FISH, EM, Isotope JAM STEC preserved in 3.7% formardehyde

Sep. 03. 03 #779 Rock Geologists (see another table)

13-47.042N, 146-0.68E 2980 779M W-1 0-5 cm DNA,RNA,CLT,BM JAM STEC no sulfate reduction 779M W-2 5-10 cm DNA,RNA,CLT,BM Hokudai 1200C site 779M W-3 10-15 cm DNA,RNA,CLT,BM Hokudai 779M W-4 15-20 cm DNA,RNA,CLT,BM Hokudai 779M W-5 20-25 cm DNA,RNA,CLT,BM JAM STEC 779M W-6 25-30 cm DNA,RNA,CLT,BM Hokudai

Sediment 13-46.997N, 146-0.185E 2926 779M Blue-1 0-5 cm PW, GAS Hokudai, Iwate univ #75 site 779M Blue-2 5-10 cm PW, GAS Hokudai, Iwate univ 779M Blue-3 10-15 cm PW, GAS Hokudai, Iwate univ

13-46.997N, 146-0.185E 2926 779M G-1 0-5 cm DNA,RNA,CLT,BM JAM STEC #75 site 779M G-2 5-10 cm DNA,RNA,CLT,BM JAM STEC 779M G-3 10-15 cm DNA,RNA,CLT,BM JAM STEC 779M G-4 15-20 cm DNA,RNA,CLT,BM JAM STEC

13-46.997N, 146-0.185E 2926 779M Black 0-15 cm PW, Isotope Okay ama Univ. #75 site

13-47.042N, 146-0.68E 2980 777CR 100 ml Geologists (see another table) Geologists (see another table)

13-47.051N, 146-0.165E 2925 777CY-1 50 ml DNA,RNA,CLT,BM JAM STEC #76 site 777CY-2 50 ml DNA,RNA,CLT,BM JAM STEC

Organism 13-46.932N, 146-0.248E 2899 Calyptogena x2 DNA, FISH, EM Iwate univ. Top of seamount 13-46.932N, 146-0.248E 2899 Bathymodiolus x24 DNA, FISH, EM Iwate univ. 13-46.932N, 146-0.248E 2899 Gastropod x1 DNA, FISH, EM JAM STEC


13-47.003N, 146-0.170E 2906 780M W-1 0-5 cm PW, GAS Hokudai, Okayama Univ. 2nd, Vertical, from ODP hole 780M W-2 5-10 cm PW, GAS Hokudai, Okayama Univ. 780M W-3 10-15 cm PW, GAS Hokudai, Okayama Univ. 780M W-4 15-20 cm PW, GAS Hokudai, Okayama Univ.

Sediment 13-47.003N, 146-0.170E 2906 780M G-1 0-5 cm DNA,RNA,CLT,BM JAM STEC 1 st, Horizontal, from ODP hole 780M G-2 5-10 cm DNA,RNA,CLT,BM JAM STEC 780M G-3 10-15 cm DNA,RNA,CLT,BM JAM STEC

13-47.003N, 146-0.170E 2906 780M Y-1 0-5 cm DNA,RNA,CLT,BM JAM STEC around the ODP hole 780M Y-2 5-10 cm DNA,RNA,CLT,BM JAM STEC 780M Y-3 10-15 cm DNA,RNA,CLT,BM JAM STEC 780M Y-4 15-20 cm DNA,RNA,CLT,BM JAM STEC 780M Y-5 20-25 cm DNA,RNA,CLT,BM JAM STEC 780M Y-6 25-30 cm DNA,RNA,CLT,BM JAM STEC

13-47.003N, 146-0.170E 2906 780M Black-1 0-5 cm PW, GAS Hokudai, Okayama Univ. around the ODP hole 780M Black-2 5-10 cm PW, GAS Hokudai, Okayama Univ. 780M Black-3 10-15 cm PW, GAS Hokudai, Okayama Univ.

13-46.995N, 146-0.173E 2906 780CY 5 ml Geologists

Water 13-47.003N, 146-0.185E 2905 780W-1 150 ml PW, DNA, CLT, FISH JAM STEC 13-47.003N, 146-0.185E 2905 780W-2 150 ml PW, Gas, Hokudai (120 ml), JAM STEC(30 ml) 13-47.003N, 146-0.185E 2905 780W-3 150 ml PW, Gas, Hokudai (150 ml) 13-47.003N, 146-0.185E 2905 780W-4 150 ml PW, DNA, CLT, FISH JAM STEC

13-47.003N, 146-0.185E 2905 780 Pump water 10 L

13-46.930N, 146-0.243E 2899 ISCS-1 DNA, FISH,CLT JAM STEC 13-46.930N, 146-0.243E 2899 ISCS-2 DNA, FISH,CLT JAM STEC 13-46.930N, 146-0.243E 2899 ISCS-3 DNA, FISH,CLT JAM STEC long 13-46.995N, 146-0.173E 2906 ISCS-4 DNA, FISH,CLT JAM STEC

Organism 13-47.008N, 146-0.176E 2906 Bathymodiolus x20 DNA, FISH, EM Iwate univ. 13-47.008N, 146-0.176E 2906 Gastropod x1 DNA, FISH, EM JAM STEC


Sediment 15-43.700N, 147-11.994E 3583 781MY-1 0-5 cm PW, GAS Hokudai, Okayama Univ 781MY-2 5-10 cm DNA, FISH,CLT, PW, GAS JAM STEC, Hokudai, Okayama Univ 781MY-3 10-15 cm PW, GAS Hokudai, Okayama Univ 781MY-4 15-20 cm DNA, FISH,CLT JAM STEC, Hokudai, Okayama Univ 781MY-5 20-25 cm PW, GAS Hokudai, Okayama Univ 781MY-6 25-30 cm DNA, FISH,CLT JAM STEC, Hokudai, Okayama Univ 781MY-7 30-35 cm PW, GAS Hokudai, Okayama Univ

15-43.927N, 147-11.270E 3682 781CY Geologists (see another table)

15-43.700N, 147-11.994E 3583 781CR Geologists (see another table)

Water 15-43.922N, 147-11.267E 3682 781N-1 PW, GAS Hokudai Sep. 08. 03 #782

Rock Geologists (see another table)

Sediment 16-31.344N, 147-13.075E 1881 782MB-1 0-5 cm PW, GAS Hokudai, Okayama Univ 782MB-2 5-10 cm PW, GAS Hokudai, Okayama Univ 782MB-3 10-15 cm PW, GAS Hokudai, Okayama Univ 782MB-4 15-20 cm PW, GAS Hokudai, Okayama Univ 782MB-5 20-25 cm PW, GAS Hokudai, Okayama Univ 782MB-6 25-30 cm PW, GAS Hokudai, Okayama Univ 782MB-7 30-35 cm PW, GAS Hokudai, Okayama Univ 782MB-8 35-40 cm PW, GAS Hokudai, Okayama Univ 782MB-9 40-45 cm PW, GAS Hokudai, Okayama Univ

16-31.344N, 147-13.075E 1881 782MW-1 0-5 cm DNA, FISH,CLT JAM STEC 782MW-10 45-50 cm DNA, FISH,CLT JAM STEC

16-31.344N, 147-13.075E 1881 782MG 0-25 cm PW, GAS Okayama Univ., Iwate Univ 16-31.344N, 147-13.075E 1881 782MY 0-15 cm Geologists (see another table)

16-31.595N, 147-13.090E 1954 782CY Half Geologists (see another table)

16-32.056N, 147-13.246E 1987 782CB 0-5 cm Geologists (see another table)

16-31.595N, 147-12.611E 1836 782CR Full Geologists (see another table)

128

Sample enumeration of YK03-07, Leg 2 (Serpentine Seamounts)

Date Dive No. Samp le category Position Depth (m) Temp . ( ) Samp le descrip tion Volume Investigation Distribution Remarks Sep. 08. 03 #782

Rock Geologists (see another table)

Sediment 16-31.344N, 147-13.075E 1881 782M B-1 0-5 cm PW, GAS Hokudai, Okayama Univ 782M B-2 5-10 cm PW, GAS Hokudai, Okayama Univ 782M B-3 10-15 cm PW, GAS Hokudai, Okayama Univ 782M B-4 15-20 cm PW, GAS Hokudai, Okayama Univ 782M B-5 20-25 cm PW, GAS Hokudai, Okayama Univ 782M B-6 25-30 cm PW, GAS Hokudai, Okayama Univ 782M B-7 30-35 cm PW, GAS Hokudai, Okayama Univ 782M B-8 35-40 cm PW, GAS Hokudai, Okayama Univ 782M B-9 40-45 cm PW, GAS Hokudai, Okayama Univ

16-31.344N, 147-13.075E 1881 782M W-1 0-5 cm DNA, FISH,CLT JAM STEC 782M W-10 45-50 cm DNA, FISH,CLT JAM STEC

16-31.344N, 147-13.075E 1881 782M G 0-25 cm PW, GAS Okayama Univ., Iwate Univ 16-31.344N, 147-13.075E 1881 782M Y 0-15 cm Geologists (see another table)

16-31.595N, 147-13.090E 1954 782CY Half Geologists (see another table)

16-32.056N, 147-13.246E 1987 782CB 0-5 cm Geologists (see another table)

16-31.595N, 147-12.611E 1836 782CR Full Geologists (see another table)


Sediment 18-6.504N, 147-6.128E 1271 783M B-1 0-5 cm PW, GAS Hokudai, Okayama Univ 783M B-2 5-10 cm PW, GAS Hokudai, Okayama Univ 783M B-3 10-15 cm PW, GAS Hokudai, Okayama Univ 783M B-4 15-20 cm PW, GAS Hokudai, Okayama Univ 783M B-5 20-25 cm PW, GAS Hokudai, Okayama Univ 783M B-6 25-30 cm PW, GAS Hokudai, Okayama Univ 783M B-7 30-35 cm PW, GAS Hokudai, Okayama Univ 783M B-8 35-40 cm PW, GAS Hokudai, Okayama Univ 783M B-9 40-45 cm PW, GAS Hokudai, Okayama Univ

18-6.504N, 147-6.128E 1271 783M G-2 5-10 cm DNA,RNA,CLT,BM JAM STEC 783M G-4 15-20cm DNA,RNA,CLT,BM JAM STEC 783M G-6 25-30 cm DNA,RNA,CLT,BM JAM STEC 783M G-8 35-40 cm DNA,RNA,CLT,BM JAM STEC 783M G-10 45-50 cm DNA,RNA,CLT,BM JAM STEC

18-6.402N, 147-6.203E 1269 783M W 0-35 cm Geologists (see another table) 18-6.402N, 147-6.203E 1269 783M Y 0-35 cm Geologists (see another table)

18-6.289N, 147-6.375E 1324 783CB half Geologists (see another table)

18-6.647N, 147-6.114E 1234 782CR one third Geologists (see another table)

Water 18-6.504N, 147-6.128E 1271 783N-1 PW, GAS Hokudai


Sediment 19-10.206N, 147-3.042E 3545 784M Y-1 0-10 cm PW Okay ama Univ 784M Y-2 10-20 cm PW Okay ama Univ 784M Y-3 20-30 cm PW Okay ama Univ 784M Y-4 30-40 cm PW Okay ama Univ 784M Y-5 40-50 cm PW Okay ama Univ

19-10.206N, 147-3.042E 3545 784M G 0-35 cm Geologists (see another table)

Water 19-10.206N, 147-3.042E 3545 784N-1 PW, GAS Hokudai C14 Shizuoka Univ.


19-32.321N, 146-38.927E 3127 Chimney DNA,RNA,CLT,BM JAM STEC

Sediment 19-32.330N, 146-38.925E 3125 785M G-1 0-5 cm PW, GAS Hokudai, Okayama Univ 785M G-2 5-10 cm DNA,RNA,CLT,BM JAM STEC, Okayama Univ. 785M G-3 10-15 cm PW, GAS Hokudai, Okayama Univ 785M G-4 15-20 cm DNA,RNA,CLT,BM JAM STEC, Okayama Univ.

19-32.321N, 146-38.927E 3127 785M Y 0-25 cm Geologists (see another table) 785M W 0-10 cm

Water 19-32.230N, 146-38.928E 3130 785N-1 PW, GAS Hokudai C14 Shizuoka Univ.


Sediment 19-38.205N, 147-5.206E 4408 786M Blue 15 cm Geologists (see another table) 19-38.216N, 147-5.436E 4362 786M G 15 cm Geologists (see another table) 19-38.264N, 147-5.638E 4282 786M Blk 15 cm Geologists (see another table)

19-38.258N, 147-4.425E 4760 786C-long 5 cm Geologists (see another table)

Abbreviations: PW, pore water chemistry; CLT, microbial cultivation; BM, biomarke; FIS H, fluorescence in-situ hybridization

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