Why Study Why Study OceanographyOceanography??

Earth is the water planetEarth is the water planet Oceans Modulate the ClimateOceans Modulate the Climate Human Civilization in LittoralHuman Civilization in Littoral

(waves govern the coastal processes and (waves govern the coastal processes and habitat)habitat)

Life began in the Oceans, but ocean Life began in the Oceans, but ocean biological productivity is poorbiological productivity is poor

We are caught in a Malthusian TrapWe are caught in a Malthusian Trap

Earthrise over Smythii impact basin with Schubert impact crater on horizon. Views like this during Apollo missions made it clear that Earth is part of a planetary system rather than an isolated sphere, subject to the same bombardment that battered the surface of the Moon. (Apollo 11 AS11-44-6551)

The Solar System

Earth, the “Third Rock from Sun” is also called the “Lonely Planet” because,

to our knowledge as yet, earth is the only

planet with evidence of life and it is water that

creates this uniqueness.

The joint NASA/Centre National d'Etudes Spatiales Topex/Poseidon oceanography satellite ceased operations after nearly 62,000 orbits of Earth. The spacecraft lost its ability to maneuver, bringing to a close a successful 13-year mission.

Topex/Poseidon data have helped in hurricane and El Nino/La Nina forecasting, ocean and climate research, ship routing, offshore industries, fisheries...

http://www.youtube.com/watch?v=OvE22AUl-_w

NASA - Topex / Poseidon Oceanography Mission Ends

This uniqueness This uniqueness comes from two comes from two cycles that define cycles that define the Earth ...the Earth ...

hydrological cycle;

and

plate tectonics.

EvaporationEvaporation320,000 km320,000 km33

PrecipitationPrecipitation285,000 km285,000 km33

PrecipitationPrecipitation95,000 km95,000 km33

Run-off: Run-off: 35,000 35,000

kmkm33

Ocean StorageOcean Storage1,370,000,0001,370,000,000 kmkm33

EvaporationEvaporation60,000 km60,000 km33

Sediments

A conceptual look at the hydrological cycle. Notice three aspects of it:. Notice three aspects of it:

1.1. Evaporation exceeds precipitation over the oceans, Evaporation exceeds precipitation over the oceans, but precipitation exceeds evaporation on land.but precipitation exceeds evaporation on land.

2.2. Currently, atmosphere transfers by precipitation all Currently, atmosphere transfers by precipitation all the water it receives by evaporation.the water it receives by evaporation.

3.3. Run-off carries excess water as also rock materials Run-off carries excess water as also rock materials from land to to oceans.from land to to oceans.

Present is the key to the past, i.e., the geological processes today are the same as they have always been.

Mount Annapoorna, 26,545 ft (8,091 m)

http://www.ngdc.noaa.gov/mgg/image/relief_slides2.html

Earth

Venus

Mars

Some images Some images of the Martian of the Martian

surfacesurface

A team of veteran planet hunters - Astronomers Geoffrey Marcy ofthe University of California at Berkeley and R. Paul Butler of theCarnegie Institution of Washington - has discovered two Saturn-sized objects orbiting nearby stars – a discovery suggesting thatsolar systems with multiple small planets like our own may be far

more common than scientists had assumed. The new objects,announced

yesterday atNASA

headquarters,are one-third

the size ofJupiter and

maybesmaller,

suggestingthat "Earth-

mass planetsare extremely

common inthe galaxy."

www.washingtonpost.com (3/30/2000)

Mount Annapoorna, 26,545 ft (8,091 m)

The World Ocean

Area(106 km2)

Mean Depth(km)

Volume(106 km3)

Pacific OceanAtlantic Ocean

Indian Ocean

165.282.473.4

4.2823.9263.963

707.6323.6291.0

                                

Bibi ka Makbara, Aurangabad

Sun setting on Mount Everest (29,028 ft = 8,848 m)

Another view of Mount Everest

Mount Kanchenjunga: 28,169 ft (8,586 m)

http://fs1dgadrv.er.usgs.gov/edu/mearthsw.html

Evaporation320,000 km3

Ocean Storage1,370,000,000 km 3

Precipitation285,000 km3

Precipitation95,000 km3

Evaporation60,000 km3

Run-off: 35,000

km3

A conceptual look at the hydrological cycle

A trio of frames from Polar's Visible Imaging

System (VIS), taken 6 seconds apart on

December 31, 1998, captures an object rapidly descending

toward northern Europe. Because the

camera's filter isolates emission from hydroxyl

(OH) radicals, the incoming object must

have contained abundant water.

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

NOAA Current SST Anomalies: 2/14/1998

Tsunami!

Raphael (Raffaelo Sanzio: 1483-1520): “School of Athens”

cover ~71% of earth’s surface and have an average depth of ~3.8 km;

carry most (80-97.5%) of the hydrospheric water supply;

evolved ~4 Ga ago, in an event that created the atmosphere, the hydrosphere and the biosphere;

The OceansThe Oceans

evolved ~4.7 Ga ago, together with the rest of the Solar System, from a hydrogen-helium dust cloud;is largely spherical, with ~6371 km average radius, an equatorial bulge and polar flattening;is a multilayered body, with core, mantle and the crust;is unique in having water; andhas a hemispherically asymmetric distribution of land and oceans.

The Earth

O ECA

7N

(

%80.

)

L

(

AN

D

%29.2

)

Oceanridges(22.1%)Continental

platforms(18.9%)

Oceanbasin floors(29.8%)

Co

nti

nen

tal s

hel

f an

d

slo

pe

(11.

4%)

Continentalmountains

(10.3%)

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

Continental rise (3.8%)

http://www.worldatlas.com/aatlas/imageg.htm

9090o o NN

00oo

3030o o NN

6060o o NN

9090o o SS

3030o o SS

6060o o SS

La

titu

de

La

titu

de

55 1010 1515 2020

LandLand

Whole EarthWhole Earth

Surface Area (million kmSurface Area (million km22))2525

OceansOceans

HydrogenHelium

OxygenCarbon

Nitrogen

SiliconNeon

MagnesiumIron

SulphurAluminum

CalciumNickel

SodiumArgon

ChromiumPhosphorous

ManganeseChlorine

PotassiumOther elements

HHe

OCN

SiNeMgFeSAlCaNiNaArCrPMnClK

74.50023.840

0.82000.37500.0910

0.08300.05500.05700.10400.03800.00660.00740.00920.00330.00300.00320.00090.00110.00060.0003

29.8

15.6

13.933.3

1.51.82.00.2

1.9

46.6

27.7

2.15.0

8.13.6

2.8

2.61.5

UniverseWholeEarth

Earth’sCrust

Outercore

The whole earth is richer in Fe, Mg and Ni, and poorer in Si, K and Al, than what

is found on the earth’s surface.

Whole Earth density = 5.5 gm/cm3

Density of the crust = 2.7 gm/cm3

Mantle

Co

re

CrustRo

ckyM

etallic Innercore

Earth has an equatorial bulge and polar flatenning,

the equatorial radius (req) being ~21 km

greater than the polar radius (rpole) . The radius (r)

of an equivalent sphere is 6,371 km.

rpole

reqr = 6371 km

)

Equivalentsphere

- 30 m

10 m

Based on satellite mapping,the earth is now known to betruly pear-shaped, in that, added to facts of earth’s equatorialbulge and polar flatenning, the south pole is ~40 m closer to the earth’s center than the north pole.

OceansPore water in sediments

Glacier and polar icecapsSurface water (rivers, lakes)

Atmospheric moisture

1,370,000300,00025,000

30013

80.8%17.7% 1.5% 0.018% 0.0008%

1,370,00010,000

25,000 300 13

97.5% 0.7% 1.8% 0.02% 0.0009%

How much water in the hydrosphere ?An average person needs ~300,000 gallons of water per year (1 metric ton = 263 gallons), including 250,000 gallons for growing food. Indeed, nations with <150,000 gallons annual per capita water availability face severe limits to economic growth. Including all the

land and marine sedimentary

formations worldwide*

Excluding the coastal marine sediments

* Based on Karl Turekian: GLOBAL ENVIRONMENTAL CHANGE (Prentice Hall, 1996)

Hydrospheric mass in trillion metric tons

A panoramic view of the Martian surface, as seen by the Pathfinder