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

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1 Why Study Oceanography? Earth is the water planet Oceans Modulate the Climate Human Civilization in Littoral (waves govern the coastal processes and habitat) Life began in the Oceans, but ocean biological productivity is poor We are caught in a Malthusian Trap

2 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 AS )

3 The Solar System

4 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.

5 Venus Earth Mars

6 Some images of the Martian surface

7 A team of veteran planet hunters - Astronomers Geoffrey Marcy of the University of California at Berkeley and R. Paul Butler of the Carnegie Institution of Washington - has discovered two Saturnsized objects orbiting nearby stars a discovery suggesting that solar systems with multiple small planets like our own may be far more common than scientists had assumed. The new objects, announced yesterday at NASA headquarters, are one-third the size of Jupiter and maybe smaller, suggesting that "Earthmass planets are extremely common in the galaxy." (3/30/2000)

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

9 The World Ocean Area (10 6 km 2 ) Volume (10 6 km 3 ) Mean Depth (km) Pacific Ocean Atlantic Ocean Indian Ocean

10 Bibi ka Makbara, Aurangabad

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

13 Another view of Mount Everest

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

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16 A conceptual look at the hydrological cycle Evaporation 60,000 km 3 vaporation 20,000 km 3 Precipitation 285,000 km 3 Run-off: 35,000 km 3 Precipitation 95,000 km 3 Ocean Storage 1,370,000,000 km 3

17 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.

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19 NOAA Current SST Anomalies: 2/14/1998

20 Tsunami!

21 Raphael (Raffaelo Sanzio: ): School of Athens

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25 The Oceans cover ~71% of earth s surface and have an average depth of ~3.8 km; carry most ( %) of the hydrospheric water supply; evolved ~4 Ga ago, in an event that created the atmosphere, the hydrosphere and the biosphere;

26 The Earth 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; and has a hemispherically asymmetric distribution of land and oceans.

27 Continental rise (3.8%) Island arcs, trenches, guyots etc. (3.7%) Continental shelf and slope (11.4%) L ( A N D 29.2 %) Continental platforms (18.9%) Ocean ridges (22.1%) Ocean basin floors (29.8%) O C E A 0.8% ) N (7 Continental mountains (10.3%)

28 90 o N 60 o N Surface Area (million km 2 ) Whole Earth 25 Latitude 30 o N 0 o 30 o S Oceans Land 60 o S 90 o S

29 Hydrogen Helium Oxygen Carbon Nitrogen Silicon Neon Magnesium Iron Sulphur Aluminum Calcium Nickel Sodium Argon Chromium Phosphorous Manganese Chlorine Potassium Other elements H He O C N Universe Whole Earth Earth s Crust Si Ne Mg Fe S Al Ca Ni Na Ar Cr P Mn Cl K 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. Rocky Metallic Mantle Outer core Inner core Crust Core Whole Earth density = 5.5 gm/cm 3 Density of the crust = 2.7 gm/cm 3

30 r pole r = 6371 km) r eq Earth has an equatorial bulge and polar flatenning, the equatorial radius (r eq ) being ~21 km greater than the polar radius (r pole ). The radius (r) of an equivalent sphere is 6,371 km. Equivalent sphere 10 m Based on satellite mapping, the earth is now known to be truly pear-shaped, in that, added to facts of earth s equatorial bulge and polar flatenning, the south pole is ~40 m closer to the earth s center than the north pole m

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37 * Based on Karl Turekian: GLOBAL ENVIRONMENTAL CHANGE (Prentice Hall, 1996) 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. Hydrospheric mass in trillion metric tons Including all the land and marine sedimentary formations worldwide* Excluding the coastal marine sediments Oceans Pore water in sediments Glacier and polar icecaps Surface water (rivers, lakes) Atmospheric moisture 1,370, ,000 25, % 17.7% 1.5% 0.018% % 1,370,000 10,000 25, % 0.7% 1.8% 0.02% %

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