The 6th Joint Meeting of the UJNR Panel on Earthquake Research

Present situation of monitoring, prediction and information for volcanic disaster mitigation in Japan

Koji Aizawa

Division of VolcanologyDepartment of Seismology and VolcanologyJapan Meteorological Agency JMA

Today’s Contents

Overview of Volcanic Disaster mitigation Operated by JMAExample of Recent Response for Volcanic Disaster by JMA and Local Authorities

JMA

Active Volcanoes in JapanDefinition of ACTIVE volcanoes :

Volcanoes that erupted in recent 10,000 years orhave vigorous fumaroles

TOTAL: 108 volcanoes

JMA

Volcanic eruption of last 10 years in JapanYear 96 97 98 99 00 01 02 03 04 05 06

Meakan-Dake ▲ ▲ ▲

Tokachi-Dake ▲

Usuzan ▲ ▲

Hokkaido Komagatake ▲ ▲ ▲

Akita Yakeyama ▲

Asamayama ▲ ▲

Miyakejima ▲ ▲ ▲ ▲ ▲ ▲

Izu-Torishima ▲

Iwo-jima ▲ ▲

Fukutoku-oka-no-ba ▲

Kuju-san ▲

Asosan ▲ ▲ ▲

Sakurajima ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲

Satsuma-Iwo-jima ▲ ▲ ▲ ▲ ▲ ▲ ▲

Suwanose-jima ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲

Moyoro-Dake ▲

▲ eruption occurred

JMA

Active Volcanoes in Japanand Volcano Observations and Information Centers (VOICs)

N32°

N28°

N24°

Beyonesu RocksSumisujimaIzu-Torishima

Nishinoshima

Kaitoku SeamountFunka Asane

IojimaKita-FukutokutaiFukutoku-Okanoba

Minami-Hiyoshi Seamount

E140° E144°

SashiusudakeOdamoisanOshima-Oshima

MoyorodakeChirippusan

Etorofu-YakeyamaBerutarubesan

Etorofu-Atosanupuri

ChachadakeRaususan

Tomariyama

Shiretoko-Iozan

Rausudake

Atosanupuri

Mashu

Meakandake

Taisetsuzan

Maruyama

Tokachidake

Eniwadake

UsuzanHokkaido-Komagatake

TarumaesanEsanKuttaraOsorezan

Iwakisan

Towada

Hakkodasan

HachimantaiIwatesan

Akita-Yakeyama

KurikomayamaNaruko

Zaozan

Adatarayama

Chokaisan

Nasudake

Nikko-ShiranesanAkagisanHarunasan

FujisanHakoneyama

MiyakejimaIzu-Oshima

Izu-Tobu Volcanoes

Niijima

KozushimaHachijojima

Aogashima

MidagaharaYakedake

NorikuradakeHakusan

Ontakesan

Bandaisan

Hiuchigatake

Tsurumidakeand Garandake

Kujusan

Unzendake

AsosanKirishimayama

Sakurajima

KaimondakeSatuma-Iojima

Kuchinoerabujima

Nakanoshima

Suwanosejima

Kusatsu-Shiranesan

Asamayama

Azumayama

Nansei Islands

Submarine Volcano NNE of Iriomotejima

Io-Torishima

Fukuoka VOIC

Tokyo VOIC

Sendai VOIC

Sapporo VOIC

Myokosan

Niigata-Yakeyama

Sapporo VOIC

RuruidakeRishirizan

YoteisanNiseko

HijioriNumazawa

Takaharayama

Akandanayama

Yokodake Toshima

Mikurajima

Sofugan

Kaikata Seamount

Nikko Seamount

SanbesanAbu Volcanoes

Yufudake

Fukue VolcanoesYonemaru and Sumiyoshiike

Wakamiko

Ikeda and Yamagawa

Kuchinoshima

Sendai VOIC

Tokyo VOIC

Fukuoka VOIC

Akita-Komagatake

Izu-Ogasawara Islands

Area of responsibility

26 volcanoes written with red letters are continuously monitored by JMA.

Disaster Prevention Authorities,Mass Media

VOIC

Meteorological Observatories

Regular survey of volcanoesEmergency observation of volcanoes

Quick look analysis and watch of dataIssuance of Volcano Information

24 hours Watch

VOICGeneral Public

Real-time telemeter

Mobile Observation Team

Volcanic Regular Bulletin

Volcano Information

Diagnosis of Volcanic Activity

Detailed Analysis of・ Seismic and Geodetic data・ Volcanic fumes activity

Data Analysis

Dispatch ofMobile ObservationTeam

Collaborative work with researchers

Tiltmeter

GPS InfrasonicMicrophone

High-sensitive Visual Camera

Seismometer

Volcano Information and

Volcano Information

Volcanic AlertVolcanic Alert is issued when volcanic activities are extremely intensified and urgent countermeasures to prevent/mitigate damage to human lives are required.

Volcanic Advisory is issued when unusual volcanic phenomena are observed and preparation for disaster prevention/mitigation is required.

Volcanic Advisory

VolcanicObservation Report

Volcanic Observation Report is issued as supplemental information to Volcanic Alert and/or Volcanic Advisory.

Bulletin of Volcanoes

Volcanic Regular Bulletin (Monthly)

Monthly Report on Earthquake and Volcanoes in Japan

Weekly Report on Earthquake and Volcanoes in Japan

JMA

Volcanic Activity Levels

Volcanic Activity Levels by JMA

５ VERY LARGE ERUPTION

４ LARGE-MIDDLE ERUPTION

３ SMALL ERUPTION, CAUTION

２ ACTIVE

１ CALM

０ DORMANT

ALER

TA

DV

.

Volcanic O

bservation Report

Dessimination of Volcano Information

Volcano Information

Coordinating Committee of Prediction of Volcanic Eruption

１９７４～Members :Volcanologists and public offices

UniversitiesResearch Institutes(NIED, GSJ, PWRI)Geological Survey InstituteMinistry of Land, Infrast-

ructure and TransportCabinet OfficeMinistry of EducationJapan Coast GuardJapan Meteorological Agency

(Secretariat)

Eruption of Asama volcano in 2004

Distribution of continuous observation points at Asama by JMA as of March 2006

■: Seismometer ◆: Infrasonic microphone, ◎: Seismic intensity meter☆: Tiltmeter●: GPS ★: Visual camera.

JMA

Level Volcanic activity Eruption

5

Very large eruption or possibilityPyroclastic flow and/or lava flow

reach to distant area from the mountain.

Pyroclastic flow and/or lava flow reach to the town distant from the mountain.

4 Large eruption or possibilityBig explosion affects the town.

Volcanic bombs reach to the town (more than 3km distant from the crater).

Small pyroclastic flow, air shock affects the houses in the town.

3

Explosive eruption at the summit crater or possibility

Explosion occurs. orPrecursor of eruption e.g.Large flux of volcanic gasSeismic swarmGlowing etc.

Explosive eruption.Volcanic bombs reach to the mountain slope (within

3km distant from the crater)Very small pyroclastic flow

2

ActiveVolcano is rather active. e.g.,

Volcanic gas increasesVolcanic earthquakes

Very small eruption might occur occasionally.

1CalmActivity of volcanic quakes,

smokes and others is low. Low possibility of eruption

0 Dormant No possibility of eruption

The restriction rule of the climbing mountain according to the level

The rule for off-limits of Asama

Level 0 : No restrictionLevel 1 : Off-limits within 500m from the crater.Level 2 : Off-limits within about 2 km from the crater.Level 3 : Off-limits within 4 km from the crater.

JMA

MLIT(2004)

Volcanic glow before eruption

The photo was taken on 7 August 2004 from Karuizawa Weather Station about 8km south of the vent.Volcanic glow was observed only at night by highly sensitive video camera from 25 July 2004 about 1 month before the eruption.

JMA

Eruption at 20:02 on 1 September 2004.

• Upper left: Right after the eruption, light of plume was seen through the clouds.

• Upper right: After that, volcanic bombs scattered as far as 2km from the vent.

• Lower: An example of photo taken in fine weather. Red dotted line shows the area where volcanic bombs scattered on 1 September 2004.

0

100

200

300

2003/10/1 2003/12/1 2004/2/1 2004/4/2 2004/6/3 2004/8/3 2004/10/4 2004/12/4

012345

2003/10/1 2003/12/1 2004/2/1 2004/4/2 2004/6/3 2004/8/3 2004/10/4 2004/12/4

Eruption in 2004

Volcanic Activity Level

Volcanic quakes Eruptions

01020304050

2004/8/31 0:00 2004/9/1 0:00 2004/9/2 0:00 2004/9/3 0:00

Hourly number of quakes EXP.

LEVEL 2 LEVEL 3

Observation Report

The local governments forbade entering the area within 4km from the active crater!

Precursor of eruption at AsamaTilt change and B type earthquakes before several to 30 hours

22 23 24 25 September 2004

Explosions Precursors Predicted

Sep. 1 ○ △Sep. 23 ○ ×Sep. 29 ○ ○Oct. 10 × ×Nov. 14 ○ ○

No Explosion

Oct. 6 ○ －Feb. 21-22 ○ －

JMA

Ground deformation and volcano information

9月27日 9月28日 9月29日 9月30日

9月27日 9月28日 9月29日 9月30日

Hourly frequencies of BH type volcanic earthquakes

S-up,W-up0.2μrad

Eruption

Volcano information

Volcano information

On 29 September

At 00:43 volcano info.

At 08:15 volcano info.

At 12:17 eruption

JMA

SummaryThere are difficulties to exactlypredict volcanic eruption on presenttechnical level.

But, at volcano where monitoring system is operating, some eruptions rarely occur completely without precursors, so we can issue Volcano information before eruption in some case.

For volcanic disaster mitigation, it is important to operate volcanic monitoring system and issue adequate information to the public. JMA

ありがとうございました。

Thank you!

Official mascots of JMA

“Hare-run”