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• ContinentalShelf 

• Continental

Edge

• ContinentalSlope

Ocean and Ocean Currents

Oceans are used for marine resources, generating power, as CO2 sinks and for

precipitation.

 The Relief of the Ocean

• Continental Shelf- This is seaward etension of the continent from the

shoreline to the continental edge. CS are formed either !" the process of

erosion or the process of deposition.

•

• Signi#cance of Continental Shelf-

•  Their shallowness ena!les sunlight to penetrate which encourages growth

of plankton, marine life etc. CS are therefore the richest #shing grounds in

the world.

•  Their gentle slope and limited depth keep out cold under currents and

increase the heights of tides. This helps the ships to enter or lea$e port

during high tide period.

• Continental Slope-%fter the continental shelf ends at the continental edge,

there is a sharp fall in gradient and that forms the continental slope.

• Salinit" of Ocean- &&' of ocean water is Sodium Chloride. (ue to free

mo$ement of water, the proportion of di)erent salts remains constant. *ut

the degree of concentration i.e. the salinit" di)ers from place to place.

Salinit" of Oceans depends on the following factors+

• Rate of e$aporation- The water in the igh ressure *elts of the Trade

inds (eserts !etween 2/ degree and 0/ degree 1 and S ha$e high

salinit" !ecause of high rate of e$aporation caused !" high temperatureand low humidit". The temperate oceans ha$e lower salinit" due to lower

rate of e$aporation.

• %mount of fresh water added due to rain, streams etc+ n E3uatorial water

the salinit" is low as there hea$" rainfall and high humidit" in these areas.

%lso areas in which huge ri$ers drain ha$e lower salinit".

 The Temperature of Ocean ater+

• Since water warms up and cools down much more slowl" than the land,

the annual range of temperature in an" part of ocean is $er" small.

•  The temperature also decreases with depth !ut e$en in the deepest ocean

trenches the water ne$er free4es.

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5o$ement of Ocean Currents+

• arm Currents- 6low from e3uatorial regions towards the poles.

• Cold Currents- 6low from olar Regions towards the e3uatorial regions.

• 6actors that determine 7ow of Ocean currents +

• 8%1ET%R9 1(S- Trade winds !low !etween the e3uator and the tropics

:of Cancer and Capricorn; that mo$e the e3uatorial waters poleward andwestward. This wa" the eastern coasts of continents of kept warm. E.g.

 The 1orth-East trade winds mo$e the

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