1. Oceans,
Seas, Lakes
and Others

2. Ocean
• Definition
– An ocean is a body of salt water with no
boundaries and limitless volume
• It is the largest water body

3. • There are only five oceans in the
world in the order of size (largest to
smallest)
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The Pacific Ocean
The Atlantic Ocean
The Indian Ocean
The Southern Ocean
The Arctic Ocean
• The Southern Ocean was approved in
2000 by the International Hydrographic
Organization. It is now the fourth
largest ocean

5. • Largest Ocean
– The Pacific Ocean is the largest
ocean in the world.
– It covers almost one third of the
Earth's surface
• Smallest Ocean
– The smallest ocean is the Arctic
Ocean, which is about 10 times
smaller than the Pacific Ocean

6. • Ocean beds are very deep, and
support only very basic life forms
like bacteria and shrimp
– Because no light reaches there and
the pressure are such that marine
life cannot survive
• An idea of the ocean depth the
Pacific Ocean has an average
depth of 3790 meters or 12,430
feet

7. Sea
• Definition
– A sea is part of an ocean that is partially
surrounded by land
• If it is totally surrounded by land, then
it's called an inland sea
– Example
• Caspian Sea
• Aral Sea

8. • Seas being close to land are
generally much shallower than
ocean
– Therefore, it is possible for plant
and animal life to thrive on a sea
bed because it is generally lit up by
light
• The average depth of the
Mediterranean Sea on the other
hand is 4690 feet

9. • There are numerous seas. Following are
few seas (by size):
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South China Sea  Asia
Caribbean Sea  North America
Mediterranean Sea  Asia, Europe, Africa
Bering Sea  Asia and North America
Arabian Sea  Asia
Sea of Okhotsk  Asia
Sea of Japan (East Sea)  Asia
East China Sea  Asia
Andaman Sea  Asia
Black Sea  Asia and Europe
Red Sea  Africa and Asia

11. Gulf
• Definition
– A deep inlet of the sea almost surrounded by
land, with a narrow mouth
– A body of water surrounded by land from
three sides

12. • Following are of the gulfs
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–
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Gulf of Mexico
Persian Gulf
Gulf of Oman
Gulf of Alaska
Gulf of Saint Lawrence

15. Bay
• Definition
– An area of water mostly surrounded by land
• A large bay may be called a gulf or a sea
• Bays generally have calmer waters than
the surrounding sea
– Because the surrounding land blocks some
waves and often reduces winds

16. • Following are some bays:
– Hudson Bay
– Bay of Bengal
– Bay of Biscay

19. • Bays and gulfs were significant in
the history of human settlement
because
– They can provide a safe place for
fishing as they have varied marine
geology
– Later, they were important in the
development of sea trade as the
safe anchorage they encouraged
their selection as ports

20. Lake
• Definition
– A body of relatively still fresh or salt water of
considerable size that is surrounded by land from all
sides
• Lakes are inland and not part of the ocean
• They are larger and deeper than ponds
• Very large lakes are called seas
– Caspian sea
– Aral Sea

21. • There are some natural lakes and
some artificial (man-made) lakes
• Natural lakes
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Caspian Sea (Khazar Lake), Asia
Lake Superior, North America
Lake Victoria, Africa
Huron Lake, North America
Lake Michigan, North America
Aral Sea, Asia
Tanganyika, Africa

24. • Artificial Lakes
– It is also called a reservoir
– A reservoir is an artificial lake used
to store water.
– Reservoirs are often created by
building a reinforced dam or a
barrage

25. Dam

26. Barrage

27. Waterfall
Definition
– A cascade of water falling from a height, formed
when a river or stream flows over a precipice or
steep incline
– A waterfall is a place where flowing water rapidly
drops in elevation as it flows over a steep region or a
cliff

28. • Tallest Waterfalls
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Angel Falls, Venezeula
Tugela Falls, South Africa
Tres Hermanas, Peru
Olo'upena Falls, USA
Yumbilla, Catarata, Peru

29. Angel Falls -
Venezeula

30. Tugela Falls -
South Africa

31. Tres Hermanas -
Peru

32. Olo'upena Falls
- USA

33. Yumbilla, Catarata -
Peru

34. Niagara Falls, North America