the earth’s surface, their EARTH REVEALEDcourseweb.glendale.edu/ppal/Word files/101TVF05.pdf ·...

Glendale Community College

Fall 2005

This course examines the materials

and physical features of the earth’s surface, their

evolution through dynamic interactions of the earth’s internal and external pro-cesses, and such related

issues as the earth hazards, environment, and

resources.

Telecourse

EARTH REVEALEDGeology 101: Physical GeologyTicket #7695: 3 units

Telecourse

EARTH REVEALEDGeology 101: Physical GeologyTicket #7695: 3 units*

Instructor: Poorna PalMS MBA Ph.D.

Course Website: http://www.glendale.edu/~ppal Professor of Geology Office: CS-262

∗ This is a CSU, UC, USC transfer course and satisfies the 3 semester unit general education requirement in physical sciences for the baccalaureate degree in most North American uni-versities and colleges. Students wishing to satisfy the 1-unit laboratory requirement simulta-neously can also take Geol-111, the corresponding 1-unit lab course at Glendale College.

Phone: (818) 240-1000 × 5517 e-mail: [email protected],

[email protected]@hotmail.com

(1) Section 3410: F 1500-1823 PM (CS-252) These Geol-111 lab. sections are currently available: (2) Section 3412: TR 830-1002 AM (CS-252) Telecourse Office:

Telecast: Charter (3) Section 7702: Th 1830-2153 PM (CS-252) Location: AD 145

Communications Channel 15 Tuesdays & Thursdays: 11 PM-Midnight Saturdays: 11 AM-Noon

Phone: (818)240-1000 ext 5898 or 5904 e-mail: [email protected]

Strategies for Success Telecourses are best suited for the disciplined and self-motivated students seeking alternative ways to meet their educational goals. For success in this course, therefore, an effective strategy would be to:

Attend all the six class meetings specified here. Sep 13 is the DEADLINE for ADD/Drop-without-W, Nov

Class Meetings (6-9 PM: CS-266)

Sep2: Orientation Sep 16: Review and Test 1 Oct 7: Review and Test 2

Oct 28: Review and Test 3 Nov 18: Review and Test 4

Dec 2: Review, Test 5 & Final Exam

To drop with a “W” (DROPPING OUT OF THE CLASS IS THE STUDENT’S RESPONSIBILITY).

Do well in all the quizzes and in the periodic tests and final examination mentioned above. Read the corresponding chapters in the recommended textbook before and after the broadcast. Review the broadcast tapes instead of relying on a single viewing. If you miss a broadcast, you can

view the tape in our Learning Center located in AD 232 on the second floor of the Administration Building, or borrow from the Center for a week.

Consult with the course instructor frequently, so as to clarify your doubts as soon as they arise [Office Hours: MW: 530-630 PM; TTh: 1-3 PM, F: 5-6 PM (Sept 2, 16, Oct 7, 28, Nov 18, Dec 2) or by appointment]

SI (supplemental Instruction) is available for this class (5-6 PM in CS-266, on the days of the class meetings) and can let you earn up to 2½ “extra-credit” points, for attendance and active participa-tion, besides helping your performance in the quizzes, tests and exams.

http://www.glendale.edu/~ppal

mailto:[email protected]




Schedule of Broadcasts and Corresponding Chapters in the Textbook

Broadcast Dates and Episodes1 The Corresponding Textbook2 Chapter

Feb 19 (11AM-Noon) Feb 22 & 24 (11PM-Midnight)

101 (Down to Earth) 102 (The Restless Planet)

1 (Introduction to Physical Geology)

Feb 26 (11AM-Noon) Mar 1 & 3 (11PM-Midnight)

103 (Earth’s Interior) 104 (The Sea Floor)

2 (The Earth’s Interior) and 3 (The Sea Floor)

March 4 (6-9 PM): Class Meeting and Test-1 (CS-266)

Mar 5 (11AM-Noon) Mar 8 & 10 (11PM-Midnight)

105 (The Birth of a Theory) 106 (Plate Dynamics)

4 (Plate Tectonics)


107 (Mountain Building) 108 (Earth’s Structures)

5 (Mountain Belts and the Continental Crust) and 6 (Geologic Structures)


109 (Earthquakes) 110 (Geologic Time)

7 (Earthquakes) and 8 (Time and Geology)

March 25 (6-9 PM): Class Meeting and Test-2 (CS-266)


111 (Evolution Through Time) 112 (Minerals: The Materials of Earth)

8 (Time and Geology) and 9 (Atoms, Elements and Minerals)

Apr 2 (11AM-Noon) Apr 5 & 1 (11PM-Midnight)

113 (Volcanism) 114 (Intrusive Igneous Rocks)

11 (Volcanism and Extrusive Rocks) and 10 (Intrusive Activity and Origin of Igneous Rocks)

April 11 to 16: Spring Vacation

Apr 16 (11AM-Noon) 115 (Weathering and Soils) 12 (Weathering and Soil) and Apr 19 & 21 (11PM-Midnight) 116 (Mass Wasting) 13 (Mass Wasting)

April 22 (6-9 PM): Class Meeting and Test-3 (CS-266)

Apr 23 (11AM-Noon) Apr 26 & 28 (11PM-Midnight)

117 (Sedimentary Rocks) 118 (Metamorphic Rocks)

14 (Sediments and Sedimentary Rocks) and 15 (Metamorphism, Metamorphic Rocks)

Apr 30 (11AM-Noon) May 3 & 5 (11PM-Midnight)

119 (Running Water I: Rivers, Erosion and Deposition) 120 (Running Water II: Landform Evolution)

16 (Streams and Landscapes)

May 7 (11AM-Noon) May 10 & 12 (11PM-Midnight)

121 (Ground Water) 122 (Wind, Dust and Deserts)

17 (Ground Water) and 19 (Deserts and Wind Action)

May 13 (6-9 PM): Class Meeting and Test-4 (CS-266)


123 (Glaciers) 124 (Waves, Beaches and Coast)

18 (Glaciers and Glaciation) and 20 (Waves, Beaches, and Coasts)


125 (Living with Earth: Part I) 126 (Living with Earth: Part II)

21 (Geologic Resources)

June 3 (6-9 PM): Class Meeting, Test-5 and FINAL EXAMINATION (CS-266)

1 “The Earth Revealed: Introductory Geology” (Annenberg/CPB Collection: 1992) 2 D. McGeary and C.C. Plummer: “Physical Geology ⎯ EARTH REVEALED” (Wm.C. Brown, 2002)

Schedule of Class Meetings and Activities (6:9 pm, CS-266)

September 2 (a) Introduction to the course; (b) Preview of chapters 1-3 (episodes 101-104).

September 16 (a) Review and discussions on chapters 1 through 3; (b) Class-Test 1; (c) Review of the Test; and (d) Preview of chapters 4-8 (episodes 105-110).

October 7 (a) Review and discussions on chapters 4 through 8; (b) Class-Test 2; (c) Review of the Test; and (d) Preview of chapters 8-13 (episodes 111-116).

October 28 (a) Review and discussions on chapters 8 through 13; (b) Class-Test 3; (c) Review of the Test; and (d) Preview of chapters 14-17 and 19 (episodes 117-122).

November 18 (a) Review and discussions on chapters 14 through 17 and 19; (b) Class-Test 4; (c) Review of the Test; and (d) Preview of chapters 18, 20-21 (episodes 123-126).

December 2 (a) Review and discussions on chapters 18, 20 and 21 and on the entire course

(b) Class-Test 5 and the FINAL EXAMINATION

Schedule for Quiz: Quiz-1 Quiz Quiz 3 Quiz 4 Quiz 4

Date available: Sep 13 Oct 4 Oct 25 Nov 15 Nov 29 Date due: Sep 16 Oct 7 Oct 28 Nov 18 Dec 2

Class Policies and Grading Scheme

For final grading (A > 90% > B > 80% > C > 70% > F): • Best 4 of the 5 Class-Tests will account for 60% of overall grade in the class; • The 5 Quizzes will each carry a maximum of 3 points, for a total of 15% of the grade. • The comprehensive FINAL EXAMINATION will have a weightage of 15%. • Presence and participation in class meetings/activities will account for the remaining 10%.

Taking all these tests and examinations is therefore mandatory. Also • dropping out of the course is the student’s responsibility (September 13 is the last day to

drop without a “W”, November 19 to drop with a “W”, an automatic “F” after then); • A missed test can be made up within one week of the scheduled date (arrange with the

telecourse office) (the two points for the corresponding class meeting will of course be deducted); and

• any “Extra Credit” work ⎯ an essay, term paper or research project ⎯ is encouraged, and will be graded on a -5 to +5 scale (due on or before the final meeting on June 13).

What is Physical Geology all about? Physical Geology examines the earth materials, processes, surface morphology, internal structure, evolution, resources and environment.

Visit http://cs.ndsu.nodak.edu/~slator/htm/PLANET to use “Geology Explorer: Planet Oit Information” being developed at the North Dakota State University

The subject-matter of these studies includes*

Earth and earth processes:

– The Earth’s Interior (Chapter 2) – The Sea Floor (Chapter 3) – Plate Tectonics (Chapter 4) – –

Mountain Belts and Continental Crust (Chapter 5) Geological Structures (Chapter 6)

Earth hazards, primary earth materials:

– Earthquakes (Chapter 7) – Time and geology (Chapter 8) – Atoms, Elements and Minerals (Chapter 9) – Volcanism and Extrusive Rocks (Chapter 10) – Intrusive Activity and Origin of Igneous Rocks (Chapter 11)

Secondary rocks and the related matters:

– Weathering and Soil (Chapter 12) – Mass wasting (Chapter 13) – Sediments and Sedimentary Rocks (Chapter 14) – Metamorphism, Metamorphic Rocks and Hydrothermal

Rocks (Chapter 15) Streams and Landscapes (Chapter 16)

Other surface processes, earth resources:

– Groundwater (Chapter 17) – Deserts and Wind Action (Chapter 18) – Glaciers and Glaciation (Chapter 19) – Waves, beaches and coasts (Chapter 20) – Geologic resources (Chapter 21)

*The chapter numbers here refer to those in the textbook: PHYSICAL GEOLOGY: EARTH REVEALED by David McGeary and Charles Plummer (WCB/McGraw-Hill, 1998). You can also explore the companion website of the book’s other version (you will need to match the chapter titles here, though, because the sequencing of chapters in the version presented online differs from your video-adapted version) at http://www.mhhe.com/earthsci/geology/plummer/student.mhtml

–

The current concerns in these studies include

the earth hazards like earthquakes and volcanism and the internal processes that govern them, the issues like global warming, environmental and/or evolutionary impacts of

catastrophic events, waste disposal, coastal habitat etc., and the earth resources and their potential exhaustibility.

1

http://cs.ndsu.nodak.edu/~slator/htm/PLANET

http://www.mhhe.com/earthsci/geology/plummer/student.mhtml

The processes that shape the Earth Two processes — hydrological cycle and plate tectonics — continually shape and reshape the Earth

Earth, the “Third Rock from Sun”, is called the “Lonely Planet” because, to our knowledge as yet, earth is the only planet with the evidence of life. It is also called the “Blue Planet”, because water is abundant on Earth. Compositionally, three groups of elements form the major consti-tuents of Solar System: (a) the gaseous elements H and He (e.g., Sun, Jupiter and Saturn), (b) the ice-forming elements C, N and O that occur as solid NH3 (ammonia), CH4 (methane) and H2O (ice) (e.g., Uranus and Neptune), and (c) the rock-forming elements Mg, Fe and Si (e.g., the inner or terrestrial planets — Mercury, Venus, Earth, Mars — and the asteroids and Moon.

1090.380.971.000.53

11.219.363.703.520.17

EquatorialRadius

(Earth = 1)

SunMercury

VenusEarthMars

JupiterSaturn

UranusNeptune

Pluto

333×103

0.060.821.000.11

317.8995.1414.5217.46

0.10

Mass(Earth = 1)

140954104990551739401330706

170022602500?

Density(Kg/m3)

~240 Ma88

225365687

433310759306856019091000

Lengthof year(days)*

25.38§

59244†0.997

10.41§

0.430.45†0.636.39

Lengthof day(days)

…58

108150228778

1427287044975910

Distancefrom Sun(103 Km)

*excepting that for Sun §at equator, as the period varies with latitude †retrograde

1090.380.971.000.53

11.219.363.703.520.17

EquatorialRadius

(Earth = 1)

SunMercury

VenusEarthMars

JupiterSaturn

UranusNeptune

Pluto

333×103

0.060.821.000.11

317.8995.1414.5217.46

0.10

Mass(Earth = 1)

140954104990551739401330706

170022602500?

Density(Kg/m3)

~240 Ma88

225365687

433310759306856019091000


25.38§

59244†0.997

10.41§

0.430.45†0.636.39

Lengthof day(days)

…58

108150228778

1427287044975910


1090.380.971.000.53

11.219.363.703.520.17

EquatorialRadius

(Earth = 1)

1090.380.971.000.53

11.219.363.703.520.17

EquatorialRadius

(Earth = 1)

SunMercury

VenusEarthMars

JupiterSaturn

UranusNeptune

Pluto

333×103

0.060.821.000.11

317.8995.1414.5217.46

0.10

Mass(Earth = 1)

333×103

0.060.821.000.11

317.8995.1414.5217.46

0.10

Mass(Earth = 1)

140954104990551739401330706

170022602500?

Density(Kg/m3)

140954104990551739401330706

170022602500?

Density(Kg/m3)

~240 Ma88

225365687

433310759306856019091000


~240 Ma88

225365687

433310759306856019091000


25.38§

59244†0.997

10.41§

0.430.45†0.636.39

Lengthof day(days)

25.38§

59244†0.997

10.41§

0.430.45†0.636.39

Lengthof day(days)

…58

108150228778

1427287044975910


…58

108150228778

1427287044975910


*excepting that for Sun §at equator, as the period varies with latitude †retrograde

Two reasons explain why water, which should occur all over the Solar System wherever the temperatures are between 0ºC and100ºC, is so abundant on Earth but a rarity elsewhere: (a) hydrological cycle and(b) plate tectonics. Here, hydrological cycle is the conti-nuous recycling of water between oceans, atmosphere and land. As the run-off from land eventually fills up the ocean basins and levels the land, hydrological cycle carries the seeds of its own destruction as the resulting smoothening of the surface eventually translates into the drying up of the Earth.

Evaporation320,000 km3

Ocean Storage1,370,000,000 km 3

Precipitation285,000 km3



Run-off: 35,000 km3

A conceptual look at the hydrological cycle


Ocean Storage1,370,000,000 km 3Ocean Storage1,370,000,000 km 3




Run-off: 35,000 km3

A conceptual look at the hydrological cycle

Plate tectonics, on the other hand, involves the creation of new surface area, in the form of ocean basins, so compensating for the surface area lost in folded mountain belts and deep sea

200 Ma (million years) ago

135 Ma ago

65 Ma ago

Present

Plate tectonics explains how the Earth’s surface morphology, including the

relative geography of landand oceans, has evolved

continually over thegeological time.200 Ma

(million years) ago

135 Ma ago

65 Ma ago

Present

Plate tectonics explains how the Earth’s surface morphology, including the

relative geography of landand oceans, has evolved

continually over thegeological time.

trenches. This explains why the ocean floor is made up of basalt, a volcanic rock. Obviously, the water on Earth would have long disappeared had plate tectonics not existed to

continually create the ocean basins that hydrological cycle would then fill up. Earth remains the water planet because (a) temperatures over most of the Earth’s surface are between 0ºC and 100ºC, (b) the temperature gradient in the troposphere is steep enough to allow the precipita-tion of atmospheric moisture, (c) the hydrological cycle has been perennially present, and (d) plate tectonism has occurred throughout, ever since the oceans evolved ~4 Ga ago.

2

The Sea Floor

The Oceans cover ~72% of the earth’s surface;

have an average depth of ~3.8 Km,

%2

)Continentalmountains%2

)%2)

Continentalmountains

Geology of the Sea-Floor

http://pubs.usgs.gov/pdf/planet.pdf

Visit the US Geological Survey at http://pubs.usgs.gov/pdf/planet.pdf or the Marine Geology and Geophysics Division of National Oceanic &

Atmospheric Administration’s (NOAA) National Geophysics Data Center (NGDC) at the URL: http://ngdc.noaa.gov/mgg/mggd.html

compared to ~840 m average height of the continents; and comprise <200 Ma old basaltic floor; but were plausibly created ~3.7 Ga ago;

O ECA

7N

(%8

0.)

L

(A

ND

9.2Oceanridges(22.1%)Continental

platforms(18.9%)

Oceanbasin floors(29.8%)

Con

tinen

tal s

helf

and

slop

e (1

1.4%

)

(10.3%)

Island arcs,trenches, guyots etc. (3.7%)

Continental rise (3.8%)

O ECA

7N

(%8

0.)

O ECA

7N

(%8

0.)

L

(A

ND

9.2

L

(A

ND

9.2Oceanridges(22.1%)Continental

platforms(18.9%)

Oceanbasin floors(29.8%)

Con

tinen

tal s

helf

and

slop

e (1

1.4%

)

(10.3%)

Island arcs,trenches, guyots etc. (3.7%)

Continental rise (3.8%)

Physiography of the Sea Floor Ocean floor comprises (a) continental margins and (b) deep ocean basins. Continental margins (a) can be active (i.e., seismic) or passive (i.e., aseismic); (b) comprise ~14% of ocean area, with ~750 m average depth; and (c) carry ~52% of all sediments (thickness: <7 Km). Deep ocean basins (a) cover ~85% of the ocean surface and (b) comprise (i) abyssal seafloor (~80% of ocean area, ~4.5 Km average depth, ~13% of all sediments averaging ~200 m in thickness); (ii) ridges and rises (e.g., the Mid-Atlantic Ridge, East Pacific Rise etc.): ~6% of ocean area, ~2.5 Km average depth, ~28% of world’s sediments (thickness ~8 Km); and (iii) deep sea trenches and island arcs: ~1% of ocean area, ~6.5 Km average depth, ~1% (?) of all sediments.

Bathymetric, magnetic and stratigraphic profiles across the submarine ridges and rises tend to be symmetric. Ridge axes have

the youngest rocks, high heat flow and seismicity. Interpretation of

these magnetic anomaly profiles using the Vine and Matthews model yields the map of seafloor ages.

This Postulate of Sea-Floor Spread ascribes the forming of new ocean floor to continental rifting and incessant volcanism at the rifted margins — a process that creates spreading submarine ridges and rises.

Deep sea trenches form, on this picture, when the converging sea floor edges collide.The other notable features of the sea floor include aseismic rises, seamounts, guyots, and submarine canyons.

5

http://pubs.usgs.gov/pdf/planet.pdf

http://ngdc.noaa.gov/mgg/mggd.html

Streams and Landscapes –

–

–

Running water is

the run-off of excess precipitation from land to the oceans that completes the hydrological cycle; the most important geologic agent for (a) erosion, transportation and deposition of sediments, and (b) landscape development.

Typically, 15-20% of rainfall in the hydrologic cycle becomes surface runoff, usually through streams, but also as sheet wash under favorable conditions (e.g., in the deserts). Stream, a gravity driven channel flow,

removes water from a drainage basin (internal or external) separated from other basins by the divides;

The hydrologic Cycle

Evaporation= 15 x 109

milliongallons

Land

World Ocean = 362 x1012 million gallons

Evaporation= 85 x 109

milliongallons Precipitation

= 75 x 109

million gallons

Precipitation = 25 x 109

million gallons

Run-off= 1010

milliongallons

Following USGS sites offer excellent introduction to and information on surface water resources:

http://ga.water.usgs.gov/edu/http://water.usgs.gov/data.html

– –

is typically antecedent in Southern California; and can have dendritic, radial, trellis etc. drainage patterns that reflect rock type and structure.

The longitudinal profile of a stream reflects its gradient: It is steep at headwaters (juvenile phase) with V-shaped valley, gentler when it enters the plains (adult phase) where it meanders in a broad valley with a flood plain, and nearly flat towards its mouth (mature phase) where a delta forms.

Stream erosion, transportation and deposition are controlled by (a) velocity (governed by channel shape and roughness, volume of water) and (b) discharge (= volume per unit time = flow velocity × area of channel’s cross-section) Specifically, (a) erosion involves hydraulic action, solution and abrasion; (b) transportation occurs through bed load/saltation (sand and gravel), suspension (silt and clay) and solution; while (c) deposition occurs with drop in velocity (e.g., formation of flood plains, channel-fills and levees, meander loops and placer beaches, deltas and alluvial fans ⎯ sediment supply, waves and shoreline currents control the shape of a delta).

– – –

–

Regional erosion by streams is controlled by climate (angular landforms in dry climates and rounded landforms in wet climates), rock type (slope angle decreases with the overburden grain size) and structure (folded and faulted rocks depart from the staircase character of horizontal beds).

Landscapes reflect either a reduction of slope angles from erosion approaching base level or parallel retreat of slopes across a region.

Stream terraces reflect either regional uplift which lowers the base level and promotes down-cutting or change from dry to wet climate (which increases a stream’s erosional capacity).

4

17

http://ga.water.usgs.gov/edu/

http://water.usgs.gov/data.html

http://www.ndsu.nodak.edu/instruct/sainieid/group/100-year.htm

Flood Frequency Analysis and Determination of 100-year and 500-year Floods Bernhardt Saini-Eidukat, Department of Geosciences, North Dakota State University Leopold (1994)1 describes a flood frequency curve (see below) as the relation of the size distribution of flood occurrences at a given location on a river to the frequency of these occurrences. To determine the size of a flood occurrence, either the highest annual discharge can be tabulated to form an annual flood series, or all discharge levels above an established limit can be tabulated without regard to annual occurrence. In either case, the data series represents only a sample of the discharge events at the given location, and the observed size distribution may not represent the largest or smallest peak discharge events possible. For this example, let's use the annual flood series method. To estimate probability that any discharge will be equaled or exceeded in any given year, the peak discharges are ranked from m = 1 (largest), m = 2 (second largest) and so on to m=n, where n is the number of years in the data record. For each data point, a Recurrence Interval (RI) is calculated using the Weibull equation RI = (n+1)/m which is the average time interval between the occurrence of two discharge events of a given or greater size (Lundgren, 1986, p. 240)2. The RI is the reciprocal of the probability of an occurrence. As an example, in the flood record of the Red River of the North at Fargo, North Dakota, the 11th highest discharge was 11,200 cubic feet per second on April 3, 1994 during the 112 year record (1882 - 1994) in the National Water Data Storage and Retrieval System (WATSTORE) database for North Dakota. The Recurrence Interval of this discharge level is 113/11 or about 10 years, and the probability of a flood discharge of this size occurring in any one year is 1/10, or about ten percent. The 100-year flood level is that gage height that corresponds to the discharge at RI = 100, which has a probability of being met or exceeded of 1%. Similarly, the 500-year flood level is that gage height corres-ponding to the discharge extrapolated at RI = 500, which has a probability of being met or exceeded of 0.2 %. To determine the flood plain that will be inundated by a 100- or a 500-year flood, compare the topography of the area adjacent to the river to the predicted gage height.

Gage Discharge Gage DischargeHt (ft.) (CFS) Ht (ft.) (CFS)

14 263 29 1080015 899 30 1190016 1850 31 1320017 2730 32 1470018 3460 33 1650019 4060 34 1830020 4640 35 2050021 5220 36 2290022 5780 37 2540023 6340 38 2810024 6950 39 3100025 7590 40 3400026 8260 41 3710027 9060 42 4050028 9900 43 44000

How do you translate from discharge to gage height, or vice versa? The USGS has tables of discharge vs. gage height for each gaging station. For example, if you scroll to near the bottom of the gage for Fargo, you'll see a table that shows discharge vs.gage height. Shown alongside is a part of that table.

1 Leopold, Luna B., 1994, A View of the River:

Cambridge, Massachusetts, Harvard University Press, 298 p.

2 Lundgren, L., 1986, Environmental Geology: Prentice-Hall, Upper Saddle River, New Jersey, 576 p.

http://www.ndsu.nodak.edu/instruct/sainieid/group/

http://www.ndsu.nodak.edu/instruct/sainieid/env/gif/excel.gif

http://www.ndsu.nodak.edu/instruct/sainieid/group/

http://h2o.usgs.gov/swr/ND/

http://srv1dndbmk.cr.usgs.gov/cgi-bin/stnhyd.pl?station=05054000

Underground Water

– –

–

Groundwater accounts for ~15% of the precipitation; is our largest source of freshwater (35-100 times the surface water supply); and fills pore space, cracks and crevices in rocks beneath the ground surface. The quantity of groundwater that the hydrological cycle contains remains open to speculation and uncertainties,however (see Table). Porosity and permeability reflect the ability of a subsurface horizon to hold

OceansPore water in the

sedimentsIce-caps, glaciers

Rivers, lakesAtmospheric

moisture

Total hydrosphere

Total mass(trillion tons)

1,370,000

330,00020,000

300

13

1,720,313

Share of thehydrosphere

80%

18.8%1.2%0.02%

0.0008%

100%

Considering all sediments*

Total mass(trillion tons)

1,370,000

7,00020,000

300

13

1,397,313

Share of thehydrosphere

97%

0.5%1.4%

0.02%

0.0009%

100%

Conventional estimates

*Karl K. Turekian: GLOBAL ENVIRONMENTAL CHANGE (Prentice Hall, 1996) and move groundwater. Downward percolation of ground water continues until porosity ends. Filling saturates porosity in a saturated zone, the top of which in an unconfined aquifer is the water table. Unsaturated zone above the water table is the zone of aeration. Lenses of impermeable rock may produce local water tables above the main water table.

–

Groundwater flow follows Darcy’s Law: velocity = permeability × hydraulic gradient

Aquifers carry groundwater, may be confined, in layered formations when a porous and permeable horizon is sandwiched between two impermeable layers or aquicludes: in this case we have (a) potentiometric surface, and (b) artesian springs; or

– unconfined (i.e., the bottom part of the weathered zone, immediately above the bedrock), in which case we have the water table and wells must be drilled into the saturated zone in order to tap water.

Groundwater interacts with surface water in gaining and losing streams.

Go to http://water.wr.usgs.gov/gwatlas/index.htmlto browse the groundwater atlas of US

Polluted groundwater is a serious problem: Human activity produces potential pollution from pesticides, herbicides, fertilizers, heavy metals and toxic compounds, bacteria, viruses and parasites from animal, plant and human waste, acid mine drainage, low and high level radioactive waste, and oil seepage. Other problems include groundwater withdrawal and calcitization, saltwater intrusion, and subsidence through compaction. Caves, sinkholes and karst topography result from the solutional effects of groundwater. Groundwater may also form petrified wood, concretions, geodes, cement sedimentary rocks, and develop alkaline soils. Hot springs and geysers, with their associated deposits of sinter (silica) and travertine (calcite), reflect the rise of hot groundwater and can be tapped as geothermal energy.

http://water.wr.usgs.gov/gwatlas/index.html

Deserts and Wind ActionDeserts

are “arid” or dry regions (i.e., regions that receive <25 cm (or <10 inches) of annual precipitation and

c monly occur at om– – – – –

about 30° N and S latitudes and the poles, i.e., where air pressure is usually high the rain shadows of mountains, continental interiors, the proximity to cold ocean currents, and/or high altitude Visit http://pubs.usgs.gov/gip/deserts/contents/

to read this USGS online publication on deserts.

source: http://pubs.usgs.gov/gip/deserts/what/world.html

Desert landforms

Of these, atmosphere plays the most important role. Deserts worldwide are found at ~30° N and S latitudes, to-wards the western margins of land, and at the South Pole. Note that ~30° N and S are also the latitudes at which sea surface waters are particularly salty, because evaporation exceeds precipitation. Air pressure is high at these latitudes. A separate handout is being provided on atmospheric circulation and weather in the attached handout. The model shown below is from the URL: http://pubs.usgs.gov/gip/deserts/atmosphere/

– –

–

Dunes typically characterize the deserts and form under winds that blow from one direction. Crescentic or crescent-shaped mounds that are generally wider than long, with slipface on the concave side, are the most common dune form on Earth and on Mars. The other types of dunes are linear, star, dome, and parabolic.

Desert streams tend to be – –

intermittent rather than perennial, and characterized by (a) internal drainage (e.g., Colorado, Niger, Amu and Syr darya); and (b) flash flooding. Sahara once received almost 18 inches of rain in a 3-hour period, for instance.

Desert of Southwestern U.S. – –

reflect partly the latitude effect and partly the rain-shadow effect; and are characterized by flat lying sediments in Colorado plateau and (b) block faults in the Basin and Range province.

Wind action

Visit the above USGS site at http://terraweb.wr.usgs.gov/TRS/projects/eolian/eolianmp.html

for information on aeolian mapping and related issues or go to http://www.desertusa.com/ to browse multimedia desert

life related articles in the online magazine “desertUSA”

– – –

also creates the erosion, transportation and deposition of sediments (aeolian sediments), depending on wind speed (and air temperature), topography and geology; typically produces LOESS deposits (e.g., the U.S. Midwest and China) and sand dunes; and combines with Southern California Sun to produce the Los Angeles SMOG through thermal inversion.

5

18

http://pubs.usgs.gov/gip/deserts/contents/

http://pubs.usgs.gov/gip/deserts/what/world.html

http://pubs.usgs.gov/gip/deserts/atmosphere/

http://terraweb.wr.usgs.gov/TRS/projects/eolian/eolianmp.html

http://www.desertusa.com/

Atmospheric Circulation and Weather Ocean-atmosphere interactions (a) moderate surface temperatures, (b) shape the earth’s overall weather and climate, and

(c) create ocean waves and currents. Atmosphere is the solid earth’s ~110 km thick gaseous envelope; weather

is the atmosphere’s state at a given point in time and space; and climate is the weather’s yearly averaged seasonal composite.

In the near-surface region that we are interested in, i.e., the troposphere (it extends to 10-15 km above earth’s surface and carries ~90% of the atmospheric mass), average temperatures decrease as we go up.

The atmosphere — is uniquely rich in N2 (78%) and O2 (21%) - Moon and Mars lack an

atmosphere, atmosphere of Venus is CO2-rich (~96%), while Jupiter and Saturn have H and He dominated atmospheres;

— evolved in three phases: (1) H, He rich early phase of ~4.5 Ga ago, (2) CO2, N2 and H2O rich middle phase of ~3.7 Ga ago and (3) N2 and O2 rich present phase since ~1.25 Ga ago.

Where did Earth’s CO2 go?

― Atmosphere has ~0.03% CO2, Seawater ~60 times as much. ― Carbonates (e.g., limestones) precipitate in the ocean bottom. Indeed, most of this C is

now locked up in limestones and marble. Oceans have thus depleted the earth’s atmosphere of its CO2 content.

Three forces mainly drive atmospheric circulation: (a) differential solar heating of earth’s surface, (b) gravity, i.e., equatorial bulge versus polar flattening, and (c) rotation.

As solar heating of the earth’s surface varies with latitude, — earth’s elliptical orbit and 23½° tilt of spin axis create seasons; and ― evaporation dominates radiation in the tropics while water freezes at the polar latitudes to create icecaps.

Moisture–laden warm air that rises at the equator cools down and must sink but (a) travels polewards as gravity at the poles exceeds that at equator and (b) begins equatorward return as cold surface air after sinking at the pole, so creating a convective cell.

Being basically unstable, this single cell breaks down into three, at 30° and 60° (N and S) latitudes. This creates (a) high pressure zones of sinking air masses at the 30° N and S latitudes and poles (these latitudes thus have deserts on land and high surface water salinity in the oceans), and (b) low pressure zones of rising air masses at the 60° N and S latitudes and equator (these latitudes thus have rain forests on land and low surface water salinity in the oceans).

The Coriolis deflection of these convection cells in the direction of Earth’s spin now creates: ― westward surface winds (“trade winds”) at 0°-30°N and 0°-30°S, ― eastward surface winds (“prevailing westerlies”) at 30°-60°N & S, and ― westward surface winds (“polar easterlies”) at 60°-90°N and S.

Equatorial surface air thus flows against earth’s spin direction. Warm surface waters thus stack up on the western margins of tropical/semi-tropical oceans, with the following results: ― Warm surface waters stack up on the western margins of

tropical/semitropical oceans. This (a) deepens the thermocline on the western coasts, so producing generally humid climatic conditions on one hand and poor fishing conditions on the other; and (b) creates breeding grounds for tropical storms/cyclones on these western margins.

― Upwelling of cold deep waters on the opposite eastern coasts produces arid climates on one hand but excellent fishing on the other.

6

19

Global warming will make Europe cold and dry, abruptly,

according to the National Research Council*.

Why this opposite effect? To understand this, we need to look at

the distribution of water on Earth, and water’s latent heat, to see how global warming is likely to affect the northern and southern hemispheres differently, andthe ocean currents that keep Europe unusually warm for its location.

* SCIENCE & POLICY IMPLICATIONS OF ABRUPT CLIMATE CHANGE: National Research Council (National Academy Press, Washington DC: April 2002)

Europe currently has an unusually warmer and wetter climate for its high-latitude location.

according to the National Research Council*.

Why this opposite effect? To understand this, we need to look at

the distribution of water on Earth, and water’s latent heat, to see how global warming is likely to affect the northern and southern hemispheres differently, andthe ocean currents that keep Europe unusually warm for its location.

* SCIENCE & POLICY IMPLICATIONS OF ABRUPT CLIMATE CHANGE: National Research National Academy Press, Washington DC: April 2002)Council (

Europe currently has an unusually warmer and wetter climate for its high-latitude location.

water’s latent heat of fusion is 80 cal/gm, and its latent heatevaporation is 585 cal/gm, i.e., the heat needed to evaporategram is water is enough to melt 7 times as much ice.

Therefore, global warming should affect the NorthernSouthern hemispheres in significantly different ways

N. Hemisphere587.6 billion Km3

2.8 billion Km3

S. Hemisphere782.4 billion Km3

30.1 billion Km3

OceansIcecaps,

Sea-ice & glaciers 1 Km3 = 262.4 billion gallons

Northern hemisphe60.7% sea and 39.3land, while the Souhemisphere is 80.9%and 19.1% land; anice accounts for a smproportion of waterNorthern hemisphe(0.47%) than in theSouthern hemisphe(3.7%).

Earth has a hemi-spherically asymmdistribution of landwater.

water’s latent heat of fusion is 80 cal/gm, and its latent heatevaporation is 585 cal/gm, i.e., the heat needed to evaporategram is water is enough to melt 7 times as much ice.

Therefore, global warming should affect the NorthernSouthern hemispheres in significantly different ways


2.8 billion Km3


30.1 billion Km3

OceansIcecaps,



2.8 billion Km3


30.1 billion Km3

OceansIcecaps,


Northern hemisphe60.7% sea and 39.3land, while the Souhemisphere is 80.9%and 19.1% land; anice accounts for a smproportion of waterNorthern hemisphe(0.47%) than in theSouthern hemisphe(3.7%).

Earth has a hemi-spherically asymmdistribution of landwater.

The 20th century Data reflect this, with

correlated rises, since 1900, of 0.6ºC in mean global temperatures and ~10 cm in the mean sea level worldwide; andincreased precipitation at higher latitudes, in the Northern hemisphere, and relative aridity at the lower latitudes, compared togreater precipitation throughout the Southern hemisphere, but for ~20ºS.

correlated rises, since 1900, of 0.6ºC in mean global temperatures and ~10 cm in the mean sea level worldwide; andincreased precipitation at higher latitudes, in the Northern hemisphere, and relative aridity at the lower latitudes, compared togreater precipitation throughout the Southern hemisphere, but for ~20ºS.

Oceans modulate the climate, irrespective of whether global warming is anthopogenic or not.

Oceans modulate the climate, irrespective of whether global warming is anthopogenic or not.

a

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Sources: (a) For temperature data: http://www.giss.nasa.gov/data/update/gistemp/graphs(b) For sea level data: T.P. Barnett, in CLIMATE CHANGE (IPCC Working Group Report: Cambridge University Press, 1990)

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Land as the % of Earth’s surfacearea per 1º

latitude band

40oS

0o

40oN

0

- 10% 10%0%Precipitation Change (1900-94)

10.5

Recomputed from the data in Thomas Karl, Neville Nicholls & Jonathan Gregory: The Coming Climate, Scientific American, May 1997

Land as the % of Earth’s surfacearea per 1º

latitude band

40oS

0o

40oN

0

- 10% 10%0%Precipitation Change (1900-94)

10.5

Recomputed from the data in Thomas Karl, Neville Nicholls & Jonathan Gregory: The Coming Climate, Scientific American, May 1997

A recent analysis of Earth’s heat balance* goes a step furthequantitatively demonstrating that, during the latter half of t20th century, changes in the ocean heat content have dominthe changes in Earth’s heatbalance.Much of this heat appears tohave gone particularly into thewarming of Atlantic waters.

* S. Levitus, J.I. Antonov, J. Wang, T.L. Delworth, K.W. Dixon & A.J. Broccoli: Anthropogenic warming of Earth’s climatic system. Science, 292: 267-270 (2001).

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http://www.nodc.noaa.gov/OC5/WOA98F/woaf_c

A recent analysis of Earth’s heat balance* goes a step furthequantitatively demonstrating that, during the latter half of t20th century, changes in the ocean heat content have dominthe changes in Earth’s heatbalance.Much of this heat appears tohave gone particularly into thewarming of Atlantic waters.

* S. Levitus, J.I. Antonov, J. Wang, T.L. Delworth, K.W. Dixon & A.J. Broccoli: Anthropogenic warming of Earth’s climatic system. Science, 292: 267-270 (2001).

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50

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Two kinds of currents transfer this heat across the oceans:

The resulting change is likely to be abrupt*,

the oceans: wind-driven surface currents like the Gulf Stream that carry warm tropical waters to the higher latitudes, andthe Global Conveyor Belt1 of thermohaline cir-culation that mixes all the surface and deep waters and is particularly sensitive to changes in the hydrological cycle2.

1 W.S. Broecker: “The great ocean conveyor”, Oceanography, 4: 79-89 (1991) and “Chaotic Climate”, Scientific American, Nov 1995.

2 S. Rahmstorf: Bifurcation of the Atlantic thermohaline circulation in response to changes in the hydrological cycle. Nature, 378: 145-149 (1995).

the oceans: wind-driven surface currents like the Gulf Stream that carry warm tropical waters to the higher latitudes, andthe Global Conveyor Belt1 of thermohaline cir-culation that mixes all the surface and deep waters and is particularly sensitive to changes in the hydrological cycle2.

1 W.S. Broecker: “The great ocean conveyor”, Oceanography, 4: 79-89 (1991) and “Chaotic Climate”, Scientific American, Nov 1995.

2 S. Rahmstorf: Bifurcation of the Atlantic thermohaline circulation in response to changes in the hydrological cycle. Nature, 378: 145-149 (1995).

g g y p ,based on the evidence from Greenland and Antarctic ice cothe warming that began in the Younger Dryas started withpresent Conveyor Belt and was aaccomplished rapidly; whichraises the alarming possibility that Europe may suddenly revert to its Mini Ice Age (c. 1300-1900) in a matter of decades.

Data Sources: Alley et al., Nature, 362: 527-52Grootes et al., Nature, 336: 552Blunier et al., Nature, 394: 739-

* P.U. Clark, N.G. Pisias, T.F. StockeWeaver: The role of the thermohalilation in abrupt climate change. Na863-869 (2002).

Temperature change expected by 2,050 AD should the present warming trend continueSource: http://www.giss.nasa.gov/data/update/gistemp

g g y p ,based on the evidence from Greenland and Antarctic ice cothe warming that began in the Younger Dryas started withpresent Conveyor Belt and was aaccomplished rapidly; whichraises the alarming possibility that Europe may suddenly revert to its Mini Ice Age (c. 1300-1900) in a matter of decades.

Data Sources: Alley et al., Nature, 362: 527-52Grootes et al., Nature, 336: 552Blunier et al., Nature, 394: 739-

* P.U. Clark, N.G. Pisias, T.F. StockeWeaver: The role of the thermohalilation in abrupt climate change. Na863-869 (2002).



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Glaciers and Glaciation

–

Glaciers and polar ice caps are the frozen masses of water that carry ~2% of the hydrospheric water supply.

Glacial flow is sluggish (1 mm-15 m/day)

Snow Line, the elevation above which water is always frozen, varies with

(a) altitude, (b) latitude and (c) season.

Types of glaciation:

continental glaciation (>50,000 km2 in area) and ice sheets account for ~95% of all glacial ice (e.g., Antarctica ≈ 85% and

This site http://www.glaciers.net/ is a good place to visit for professionals, students, and hobbyists interested in glacial processes and landforms.

Greenland ≈ 10%); –

–

– –

ice caps (<50,000 km2 extent), e.g., the Tundras; Alpine or valley glaciers (seen in the mountain valleys); and piedmonts or the glacial lakes.

Glacial budget: net gain of snow occurs in the zone of

Browse the satellite image atlas of world’s glaciers at USGS site http://pubs.usgs.gov/factsheet/fs133-99//

Another excellent resource for glaciologists is the USGS Open-File Report 98-31 on long-term monitoring of glaciers in North America and

Northwestern Europe that can be web-accessed at http://chht-ntsrv.er.usgs.gov/Glacier_wkshp/toc.htm

accumulation, where addition exceeds loss, whereas –

– – –

net loss of snow characterizes the zone of ablation.

This book “Looking South: The Australian

Antarctic Program

Glacial erosion: produces rock flour, varves, striations; carves “U-shaped” valleys and fjords; and forms (a) lateral, (b) medial and (c) end (i.e.,

into the 21st Century” is now available as Adobe

Acrobat PDF files at the site http://www.antdiv.gov.au/s/f.plx?/resources/looksth/index

.html

terminal and recessional) moraines and (d) drumlins.

Questions about the past ice ages (Milankovitch cycle*) and climate changes (also continental drift) arouse geological and paleoenvironmental interest. As for the first of these, the recurrent Ice Ages and Inter-glacial warm periods observed in the earth’s most recent past 2 Ma history, were ascribed by Milankovitch to the 21000, 41000 and 100000 year variations in earth’s

Visit the NOAA (National Oceanic and Atmospheric

Administration) Paleoclimatology

program at http://www.ngdc.noaa.gov/paleo/paleo.html

orbital relationships and wobble. As for the latter, recall that Alfred Wegener’s reconstruction of Pangea, an assembly of all the landmasses, at the South Pole was made to explain the observed 250 Ma glaciation in such presently far flung landmasses as South America, Africa, India, Australia and Antarctica.

*Read about the “Milankovitch Cycles in Paleoclimate” at http://deschutes.gso.uri.edu/~rutherfo/milankovitch.html

Learn the geological history of Glacier National Park at http://www.nps.gov/glac/

2

20

http://www.glaciers.net/

http://pubs.usgs.gov/factsheet/fs133-99//

http://chht-ntsrv.er.usgs.gov/Glacier_wkshp/toc.htm

http://www.antdiv.gov.au/s/f.plx?/resources/looksth/index.html



http://www.ngdc.noaa.gov/paleo/paleo.html

http://www.ngdc.noaa.gov/paleo/paleo.html

http://www.nps.gov/glac/

http://deschutes.gso.uri.edu/~rutherfo/milankovitch.html

Waves, Beaches and the Coast Waves are – single or complex sinusoidals, that can be

either capillary or gravity, of which – –

gravity waves can be wind-driven, tidal or tsunamis. As (a) gravity waves are faster the longer they are and (b) a basin must be at least twice as deep as the length of the wave, the wind generated ocean waves break as they approach the shore, at the

Following are some of the USGS sites of interest here: http://walrus.wr.usgs.gov/hazards/

erosion.html http://www.nap.edu/books/030906

5844/html/ http://marine.usgs.gov/

surf zone. This creates longshore current and littoral drift.

Tides – –

have diurnal, semidiurnal and mixed cycles, are stronger (spring tides) during the full and new moon when the luni-solar gravitational pulls add up, and

Try http://co-ops.nos.noaa.gov/about2.html for information on water levels, tides and currents

– weaker (neap tides) during the first and third quarter of moon when the two (i.e., lunar and solar) gravitational pulls are mutually perpendicular.

Tsunamis are –

–

seawaves generated by ocean-bottom seismicity (e.g., earthquakes, volcanism and/or landslides); and common on the Pacific shores because of the tectonic nature of this ocean’s boundaries.

Browse the site of Netherlands Coastal Zone Management Center at

http://www.minvenw.nl/projects/netcoast/coast/coast.htm

Beaches: –

–

–

Beach slope determines the way the waves break (spilling versus plunging and/or surging breakers). Berm is located above the level of highest wave activity, beach-face (or backshore) is above water all the time, and marine (or tidal) terrace (i.e., foreshore) is exposed during the low tides. Sand stays on the beach because it is

This NOAA (National Oceanic and Atmospheric Administration) site provides links to extensive data and

sites on waves and tides: http://www.pmel.noaa.gov/bering/pages/env_wave.html

For information on tsunamis, try this NASA site: http://observe.ivv.nasa.gov/nasa/exhibits/tsunami/tsu

n_bay.html

continually recycled between the shore and the surf zone. – In temperate zones, longshore bar grows at the cost of the berm in the

winter, when wave activity is strong, while berm grows at the cost of the longshore bar during summer, when wave activity is weak.

Coasts can be

3

– –

active (i.e., tectonic) versus passive. depositional (e.g., deltas) or erosional (e.g., fjords).

Human interference causes coastal erosion, e.g., groins produce beach-growth upstream of longshore current, shifting erosion downstream, while breakwater wall has beach-growth behind it and intensifies coastal erosion on its flanks.

Issues to ponder about

– – –

Global warming and the coastal habitat, agriculture, climate etc. Coastal construction (sea walls) and marine erosion Marine pollution and waste disposal

21

http://walrus.wr.usgs.gov/hazards/erosion.html

http://walrus.wr.usgs.gov/hazards/erosion.html

http://www.nap.edu/books/0309065844/html/

http://www.nap.edu/books/0309065844/html/

http://marine.usgs.gov/

http://www.pmel.noaa.gov/bering/pages/env_wave.html

Geologic Resources ― (a) Minerals

– –

–

The geological or extractive earth resources are essentially nonrenewable and can be broadly grouped as

mineral (metallic and nonmetallic) and energy (fossil fuels, nuclear) resources.

Kinds of mineral resources: Metallic minerals: These include ferrous metals (ores of iron,

Earth resourcesRenewable• Direct (solar)• Other (wind, tides, groundwater, oceans)

PotentiallyRenewableFresh air, water, soil

Nonrenewable• Fossil fuels (coal, oil, natural gas)• Radioactive minerals• Metallic, nonmetallic and industrial minerals

manganese, chromite, nickel, cobalt etc.), non-ferrous metals or polymetallic deposits (ores of copper, lead, zinc, tin, tungsten etc.) and precious metals ⎯ their suitability for mining is defined by their concentration factor (this value is 60 ppm for copper, 2 ppm for tin, 4 ppb for gold etc., i.e., the more scarce the resource is the smaller its concentra-

Visit the USGS mineral resources website http://minerals.usgs.gov/

tion need to be for its cost-effective extraction). – Nonmetallic and industrial minerals:

These include such gemstones as diamond, ruby, sapphire, amethyst etc. and industrial minerals and materials like barite, gypsum, halite etc.

Concentration Factor Concentration of the metal in the ore depositConcentration of that metal in average crust=

– Occurrence of mineral resources:

Deposits in igneous and metamorphic rocks: Metallic deposits like those of chromium, platinum and iron often occur in crystal setting within cooling magma. Polymetallic deposits of copper, lead, zinc, gold, silver, nickel, cobalt, tin, tungsten, molybdenum, mercury and iron occur as hydrothermal deposits (contact metamor-phism, hydrothermal veins, disseminated deposits and hot-spring deposits). Pegmatites often carry lithium, mica, rare metals and barites. Polymetallic deposits usually occur in folded mountain belts. Notice how porphyry copper and molybdenum deposits dot the entire subduction zone from Andes to the Cascades. Almost all the U.S. reserves of gold, silver, platinum and palladium come from the western U.S., from Rockies to the Sierras and Cascades.

– Other types of ore deposits: include the chemical precipitation in layers, in the case of most of iron and manganese and some copper deposits,

placer deposits of gold, tin, platinum and titanium, and concentration by weathering and groundwater (e.g., of diamond brought to the surface from kimberlite pipes; forming of bauxite and laterite by chemical weathering), and the supergene enrichment of disseminated ores.

1900 1925 1950 20001975

200

100

Pric

e (1

977-

79 =

100

)

Long-run inflation-adjusted world prices for nonferrous metals

(aluminum, copper, tin and zinc)

1900 1925 19501900 1925 1950 20001975

200

100

Pric

e (1

977-

79 =

100

)

Long-run inflation-adjusted world prices for nonferrous metals

(aluminum, copper, tin and zinc)

Exhaustibility of mineral resources: A typical problem with mineral and similar earth resources is their exhaustibility. Since our need for these resources has only been rising, this means that their prices too should rise, particularly because, with increasing use, their supply is only likely to decline. But, as this graph shows, inflation adjusted prices of four of the most used nonferrous metals ― aluminum, copper, tin and zinc ― has mostly stayed steady about the 1978 levels.

4

22

http://minerals.usgs.gov/

Geologic Resources ― (b) Energy Resources

Fossil fuels: These comprise coal, oil and natural gas, all of organic origin. Of these, coal forms from plant

remains (ancient rain forests ⇒ peats and bogs ⇒ lignite ⇒ coal) and occurs in sedimentary layers. Oil and natural gas, on the otherhand, form from decomposition of shallow marine microorganisms and are found in suitable ‘traps’ (structural and stratigraphic). The rising demand for the fossil fuels (they accounted for 85% of world’s 2000 energy use) means that the supplies of these ex-

For energy resources, a starting point would be US Department of

Energy site http://www.osti.gov/

haustble resources should drop and their prices should rise. That

Oil (43%)

Natural Gas (21%)

Coal (21%)

Nuclear (9%)

Renewa-bles (6%)

Oil (43%)

Natural Gas (28%)

Coal (18%)

Nuclear (7%)

Renewa-bles (4%)

2000 2020

Source: www.eia.doe.gov

Oil (43%)

Natural Gas (21%)

Coal (21%)

Nuclear (9%)

Renewa-bles (6%)

Oil (43%)

Natural Gas (21%)

Coal (21%)

Nuclear (9%)

Renewa-bles (6%)

Oil (43%)

Natural Gas (28%)

Coal (18%)

Nuclear (7%)

Renewa-bles (4%)

Oil (43%)

Natural Gas (28%)

Coal (18%)

Nuclear (7%)

Renewa-bles (4%)

2000 2020

Source: www.eia.doe.gov

$10

$20

$30

$40

$50

1970 1980 1990 2000

2.0%

2.5%

3.0%

3.5%

4.0%

Fraction of Proved R

eserves Used (per year)R

eal P

rice

of C

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Oil

(per

bar

rel)

xxx

x

x

xxxxx

x

xxxx x

x

xx

xxxxxxx

xx

xx

x$10

$20

$30

$40

$50

1970 1980

2.0%

2.5%

3.0%

3.5%

4.0%

5

1990 2000

$10

$20

$30

$40

$50

1970 1980

2.0%

2.5%

3.0%

3.5%

4.0%

Fraction of Proved R

eserves Used (per year)R

eal P

rice

of C

rude

Oil

(per

bar

rel)

xxx

x

x

xxx

x

x

xxxxx

xxxxx

x

xxxx

x

xxxx x

x

xx

xxx

xx

xxxxxxxxxxxx

xx

xx

xx

xx

xx

1990 2000These data are from BP Statistical Review of World Energy 2002.

the real or inflation-adjusted crude oil prices did not rise in proportion thus suggests that exhaustibility is as much a function of technology and price as of supply. Notice the estimates of 34.9 years for world’s future oil supply in 1971 and 38.6 years in 2001!

1971 641.80 18.40 102.03 34.9 1987 896.50 21.70 445.63 41.3

1972 672.70 19.30 121.33 34.9 1988 916.60 22.70 468.33 40.4

1973 635.00 21.10 142.43 30.1 1989 1011.80 23.20 491.53 43.6

1974 720.40 21.20 163.63 34.0 1990 1009.20 23.70 515.23 42.6

1975 666.10 20.10 183.73 33.1 1991 1000.90 23.10 538.33 43.4

1976 652.00 21.70 205.43 30.0 1992 1006.80 23.40 561.73 43.1

1977 653.70 22.90 228.33 28.5 1993 1009.00 23.40 585.13 43.1

1978 649.00 23.00 251.33 28.2 1994 1009.30 23.50 608.63 43.0

1979 649.20 24.00 275.33 27.1 1995 1016.90 23.80 632.43 42.8

1980 654.90 22.80 298.13 28.7 1996 1036.90 24.60 657.03 42.2

1981 678.20 21.60 319.73 31.4 1997 1040.00 26.22 683.25 39.7

1982 677.40 20.50 340.23 33.0 1998 1042.00 26.75 710.00 39.0

1983 677.70 20.30 360.53 33.4 1999 1044.00 26.22 736.22 39.8

1984 707.20 20.80 381.33 34.0 2000 1046.20 27.19 763.41 38.5

1985 707.60 20.60 401.93 34.4 2001 1050.00 27.18 790.59 38.6

1986 703.10 22.00 423.93 32.0 2002

Cumulative Production BBO

Number of Years

Remaining

Proved Reserves

BBO

Proved Reserves

BBO

Annual Production

BBO

Annual Production

BBO

Cumulative Production BBO

Number of Years

Remaining

Visit the WorldAtom site http://www.iaea.org/worldatom/ of

International Atomic Energy Agency for current news and

INTERNATIONALATOMIC ENERGY AGENCY

activities in the field of atomic energy

Radioactive minerals: – Three types of nuclear technology exist: fission technology

uses conventional (U235 -based) and breeder (U238 based) reactors while fusion technology, futuristic as yet, may eventually harness the limitless supply of heavywater: D2O.

–

Because of the differences in their half-life values, that for U238 ⇒ Pb206 decay being 4.5 Ga compared to 713 Ma for the U235 ⇒ Pb207 decay series, we have 33 times as much U238 as U235. This suggests that (a) initially, at the onset of nuclear synthesis, uranium is likely to have comprised equal amounts of U235 and U238, and (b) a shift to the U238 based technology should not only enhance mineral reserves for nuclear energy but also reduce the problem of waste disposal.

Other energy sources: these include geothermal, tidal, wind, OTEC (ocean thermal energy conversion), methyl hydrate gel etc. Discussions on earth resources can hardly be independent of the concerns about waste disposal, pollution, climate change, and the like geoenvironmental issues.

Browse Nuclear Energy Institute’s website http://www.nei.org/

23

http://www.osti.gov/

http://www.iaea.org/worldatom/

http://www.nei.org/

Natural Disasters or the Earth Hazards Natural disasters are the environmental concerns amenable to geological evaluation and include – earthquakes and volcanism, – severe weather (floods, hurricanes, tornadoes), tsunamis, landslides, erosion, etc. and – extraterrestrial catastrophism, e.g., a bolide impact may have caused dinosaur extinction.

Natural disaster trends –

–

Since the 1970s, natural disasters have accounted for two-thirds of the disaster-related fatalities worldwide. Contrary to the common perception, earthquakes and volcanism have not produced most of these fatalities.

These fatalities seem more common in the economically less developed Third World, than in the economically developed countries, where their effect has been mostly as property losses. This makes the efforts at disaster mitigation a socioeconomic necessity.

Earthquakes: 8%

Floods: 19%

High winds: 20%

Drought & Famine: 6%

Volcanoes: 1%

Landslides: 3%

TotalFatalities

worldwide(1971-95)

= 8,219,000

Othernaturaldisasters: 9%

Man-madedisasters: 34%

0 4 8 12 16

ETHIOPIA

CHINABANGLADESH 31.9

SUDAN

48.4

DISASTER FATALITIES* (1971-95: IN THOUSANDS)

MOSTLY FLOODS

MOSTLY FAMINE

MOZAMBIQUE

MOSTLY MASS STARVATIONINDIA

SOVIET UNION/CIS STATES

IRANPHILIPPINES

NICARAGUA

COLUMBIAGUATEMALA

SOMALIA

NIGERIA

PERU

MEXICO

HONDURAS

* International Federation of Red Cross and Red Crescent Societies (The Economist, Sept 6, 1997)

D eathsD am age

(b ill 1996$)19901980197019601950194019301920

$19.1$21 .6$21 .0$13 .3

$5.0$5.1$1.8

1990198019701960195019401930192019101900

161226570750220

1050213010508100

Tw entie th C entury H urricane D estruction in the U .S .

Mitigation efforts: Natural disaster fatalities mostly follow an exponential scaling law that has a predictive value. Notice how all the fatality-frequency plots here display expo-nential decay (i.e., the fatal events are far fewer than the ones that are progressively less fatal). Clearly, disaster mitigation policies have to focus on either (a) increasing or (b) decreasing the slope of regression line here or (c) lowering the intercept!

The paradox of technology:

The environmental stress attendant to population growth has created a catch-22

Number of Fatalities per Event3 30 300 3,000

3

0.3

0.03

Tornadoes

FloodsTornadoesHurricanesEarthquakes

Num

ber o

f Eve

nts

per Y

ear

0.1

1

10

0.011 10 100 1,000 10,000

Floods

Hurricanes

Earthquakes

U.S. 20th Century Natural Disaster Fatality-Frequency Plots*

* S.P. Nishenko and C.C. Barton: “Scaling Laws for Natural Disaster Fatalities” inREDUCTION AND PREDICTABILITY OF NATURAL DISASTERS (Eds: Rundle,Turcotte and Klein) (Addison-Wesley, 1996)

situation: poverty and deprivation enhance environmental stress but the increasing recourse to technology needed to ameliorate this situation often ends up aggravating this stress.

Access this database on using satellite remote sensing for disaster mitigation efforts at

http://ltpwww.gsfc.nasa.gov/ndrd/

6

24

http://ltpwww.gsfc.nasa.gov/ndrd/

Nature and dimensions of the environmental crisis Dimensions and Premises of Environmental Debate

— The (a) human, technological and natural and (b) exhaustible, renewable and perennial dimensions of resources.

— Inelasticity of food demand versus technology’s degradation of environment. — Anthropogenic, biocentric and temporal streams of environmental concerns.

Some Environmental Perspectives: — Since population grows geometrically, while resources grow arithmatically, a

continued population growth is unsustainable (Thomas Malthus). — The invisible hands of supply and demand guide a freely competitive market to a

just and fair distribution of wealth (Adam Smith). — Earth provides enough for every person’s need but not for every person’s greed

(Mahatma Gandhi). — Nature, to be commanded, must be obeyed (Francis Bacon).

The exhaustibility of earth resources and the degradation of the environment are problems irrespective of whether we take — the Malthusian view that exhaustibility

limits economic growth; — the neo-Malthusian perspective that

resource exploitation has environmental limits; or

— the Ricardian perspective that progressive depletion raises costs and lowers quality;

This is particularly true when we note that — technology enhances efficiency but

degrades the environment, and — of all the natural disasters deleterious to

our habitat and environment, the climate

FranceU.K.

China

Sweden

Russia

USA

BrazilItaly

Singapore

0.1

1

10

100

0.01 0.1 1 10

Mexico

GermanyIndia Japan

NorwaySwtizerland

Saudi ArabiaNetherlands Australia

Spain

GDP (PPP) in trillion US $

Economic prosperity and energy consumption are closely correlated

Ene

rgy

cons

umpt

ion

(in te

rraj

oule

s) FranceU.K.

China

Sweden

Russia

USA

BrazilItaly

Singapore

0.1

1

10

100

0.01 0.1 1 10

Mexico

GermanyIndia Japan

NorwaySwtizerland

Saudi ArabiaNetherlands Australia

Spain


Economic prosperity and energy consumption are closely correlated

Ene

rgy

cons

umpt

ion

(in te

rraj

oule

s)

related ones raise the most panic but promise the best prospects for mitigation. as is evident from these two graphs.

Our current environmental concerns therefore range from — geoenvironmental problems: from

global warming and air and water pollution to the degradation of coastal habitat; to

— geological problems: from predicting the earth hazards to solving the problems in foundation engineering and earthquake-proofing; and

0.03

0.1

1

3

0.1 1 10

0.3

30.30.03

USA

China

Japan

Russia

GermanyIndiaU.K.

UkrainePoland Canada

ItalyFrance

Iran

BrazilMexico

SouthKorea

Australia

SouthAfricaNorth

Korea

Kazakstan

...and so are economic prosperity and carbon emissions


Tot

al C

arbo

n E

mis

sion

(b

illio

n to

ns)

0.03

0.1

1

3

0.1 1 10

0.3

30.30.03

USA

China

Japan

Russia

GermanyIndiaU.K.


ItalyFrance

Iran

BrazilMexico

SouthKorea

Australia

SouthAfricaNorth

Korea

Kazakstan

0.03

0.1

1

3

0.1 1 10

0.3

30.30.03

USA

China

Japan

Russia

GermanyIndiaU.K.


ItalyFrance

Iran

BrazilMexico

SouthKorea

Australia

SouthAfricaNorth

Korea

Kazakstan

...and so are economic prosperity and carbon emissions


Tot

al C

arbo

n E

mis

sion

(b

illio

n to

ns)

– geoeconomic problems: from depletion of resources (energy, minerals, water and soil) to waste disposal.

7

25

STATE OF THE PLANET

THE FRAYING WEB OF LIFE

The new U.N. reportexamines the state ofknowledge about five majorcategories of ecosystems,scoring them in terms oftheir capacity to deliver thegoods and services thatsupport life and humaneconomies. It looks at howpeople have alteredecosystems and affectedtheir robustness, and wheretrouble might lie in thefuture.

-

FOREST

8

26

A video-guide for the “Earth Revealed” videotapes

Focus on these issues and/or answer these questions as you view the videos: (Taken from the URL: http://jersey.uoregon.edu/~mstrick/RogueComCollege/G100/StudyGuides/VSGindex.html)

Episode 101: Down to Earth • •

•

•

•

•

•

•

What environmental conditions make life possible on earth? What is the goal of the study of geology? Why do geologists rarely conduct experiments? Describe earth's internal and external heat engines. How do these two engines shape the planet? What exciting theory to study the earth is the video talking about? Explain its salient features. What are the natural resources mentioned in the film? Discuss the issues that arise from their usage. How do geologists attempt to predict volcanic eruptions? What is the Parkfield experiment all about? Can any steps be taken to prepare for earthquakes? What earth process is more destructive than volcanoes and earthquakes? Where are many of the earth's major population centers? What are the challenges and obligations of modern earth scientists?

Episode 102: The Restless Planet • • • • • • •

•

•

• •

•

Where on earth are living things found? Explain the nebular hypothesis. Why do we see so few meteorite impact scars on earth? Describe the solar system and the differences between the planets. Describe the process of differentiation. What factors contributed to the early heating of the earth? Describe the internal structure of the earth. Why is the inner core solid? Describe (a) the origin and composition of earth's early atmosphere, and (b) the sources that have contributed to earth's hydrosphere. How did earth's early oceans contribute to the origin and evolution of life? How did early life forms change earth's atmosphere? Why is earth still geologically active? What is convection and how does it relate to earth's internal heat engine? Describe the theory of plate tectonics.

http://jersey.uoregon.edu/~mstrick/RogueComCollege/G100/StudyGuides/VSGindex.html

Episode 103: Earth's Interior •

• •

•

• •

What information can we get from the study of seismic waves? Describe reflection and refraction. Describe the internal structure of the earth. What is an ophiolite? Describe in detail. Why are ophiolites of special interest to geologists? Describe the two basic types of seismic waves. How do geophysicists use this difference to study the interior of the earth? What happens to P and S-waves as they travel though the different layers that make the earth? What is a gravimeter and how does it work? How is earth's magnetic field used to study the earth? How do Faraday's observations lead to an understanding of earth's magnetic field? What are paleomagnetism and magnetic field reversals? How often does earth's magnetic field reverse?

Episode 104: The Seafloor •

•

•

•

•

• •

What are conditions like on the seafloor? What is the main type of rock found on the seafloor? Describe the topography of the seafloor: shelf, slope, canyons, rises and abyss. What are pelagic sediments? What does the oceanic ridge system represent? What is found at the crest of the oceanic ridges? Discuss the age of the ocean floor. What is seafloor spreading and what does it do to the ocean floor? What is subduction? Discuss methods used by marine geologists to study the seafloor. What is GLORIA and the GPS, and how are they used to map the seafloor? Why are the maps produced by GLORIA so important? What conditions limit exploration and development of resources from the seafloor? Describe the ecological environment found at hydrothermal vent sites. Discuss pros and cons of the study, exploration, and development of the seafloor.

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