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Ocean water description slide share in detail
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- 2. Blue planet Theearth has an abundant supply of water on its surface, hence our planet is called blue planet. Reservoir percentage Oceans 97.25 Ice caps 2.05 Glaciers & ground water 0.68 others
- 3. HYDROLOGICAL CYCLE The hydrologicalcycle is the circulation of water within the earth’s hydrosphere in different forms i.e. the liquid , solid and the gaseous phases. It is the continuous exchange of water between the oceans, atmosphere, land surface and subsurface and the organisms
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- 5. DIVISIONS OF THEOCEAN FLOOR The ocean floors can be divided into four major Divisions • The continental shelf • The continental slope • The deep sea plain • The oceanic deeps Other minor relief features are • Ridges , hills, sea mounts, guyots , trenches and canyons , etc
- 6. Continental shelf Thecontinental shelf is the extended margin of each continent occupied by shallow water An average slope 10 or less Average width is about 80 kms Very narrow shelves in Chile and w. Sumatra Widest shelves in Siberia (1500 km) The depths varies between 30m to 300m The continental shelves are covered with variable thicknesses of sediments brought by rivers, glaciers etc. Source of fossil fuels
- 8. Continental slope Thecontinental slope connects the continental shelf and the ocean basins. The slope varies between 2-50 The slope boundary indicates the end of the continents . Canyons and trenches are observed in this region. The depths vary between 200 to 3000m.
- 10. Deep sea plain Deep sea plains are gently sloping areas of the ocean basins. These are the smoothest region of the world. These plains covered with fine grained sediments like clay and silt The depths vary between 3000 to 6000m.
- 12. Oceanic deeps orTrenches These areas are the deepest parts of the oceans. The trenches are relatively steep sided, narrow basins. They are some 3-5 km deeper than the surrounding ocean floor. 57 deeps have been explored.
- 16. Minor relief features Mid-oceanicridges A mid-oceanic ridge is composed of two chains of mountains separated by a large depression. Height 2500 m Iceland: a part of mid Atlantic ridge
- 18. Seamount • A submarinemountain or peak rising more than 1000m above the ocean floor is known as a sea mount. • Does not reach the surface of the ocean • Volcanic origin • E.g – emperor seamount in pacific
- 21. guyots It isa flat topped sea mount. More than 10000 sea mounts and guyots exist in the pacific ocean alone.
- 23. Submarine canyons These aredeep valleys , they are sometimes found cutting across the continental shelves and slopes. E.g – Hudson canyon Atoll These are low islands found in the tropical oceans consisting of coral reefs surrounding a central depression.
- 24. TEMPERATURE OF OCEANWATER Factors affecting temperature distribution of the oceans • Latitude • Unequal distribution of land and water • Prevailing Wind • Ocean currents
- 25. Distribution of temperature •The boundary region from where there is a rapid decrease of temperature is called Thermocline. (100- 400 m below the sea surface) • 90 % of the total volume of water is found below the Thermocline. • Temperature decreases from equator towards poles. (0.5 0 C / latitudes) • Average surface temperature is 27 0 C
- 26. SALINITY OF THEOCEAN • Salinity is the total content of dissolved salts in sea water • It is expressed in parts per thousand or ppt(0/00) • Highest salinity water bodies lake Van in Turkey (330 0/00) dead sea (238 0/00) great salt lake (220 0/00)
- 27. SALINITY OF THEOCEAN Factors affecting salinity • Temperature • Evaporation • Rainfall • Fresh water from the rivers • Melting of ice • Confluence of Ocean currents
- 28. Horizontal Distribution ofsalinity • Salinity ranges from 330/00 - 370/00. • Red sea 410/00. • Pacific ocean 310/00 - 350/00. • Atlantic ocean 36 0/00. • Indian ocean 350/00.
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- 30. Vertical Distribution ofsalinity • Salinity increases with depth • Salinity increases with depth and there is distinct zone called Halocline where salinity increases sharply .