The New Childrens Encyclopedia

(Marvins-Underground-K-12) #1

The world’s oceans


Earth is known as the “blue planet,” after the oceans


that cover two-thirds of its surface. Much of the


ocean remains mysterious because the dark, cold


conditions make its deep waters difficult to explore.


MIGHTY OCEANS
Our oceans are in constant
motion. They are driven by
flowing currents that mix warm
and cold water, which in turn
affect our climate. There are five
great oceans. In order of size,
these are the Pacific, Atlantic,
Indian, Southern, and Arctic
oceans. Smaller areas are
called seas.

EARTH


TELL ME MORE...


Twice a day the sea level rises and falls.
This movement is called a tide. It is
caused by the gravitational effects of
the Moon, Sun, and Earth. When
these combine, a bulge of water forms
on either side of Earth, causing a high
tide. When it passes, the tide goes out.

d WAVE POWER Waves
contain a huge amount of
energy. This energy can be
captured and turned into
electricity.

North Sea
Average depth 308 ft (94 m)

Arctic Ocean
Average depth 3,248 ft (990 m)

Mediterranean Sea
Average depth 4,921 ft (1,500 m)

Indian Ocean
Average depth 12,762 ft (3,890 m)

Southern Ocean
Average depth 14,763 ft (4,500 m)

Pacific Ocean
Average depth 14,041 ft (4,280 m)

Atlantic Ocean
Average depth 10,925 ft (3,330 m)

World oceans
The depth of the ocean varies
enormously. On average, the
Southern Ocean is the deepest,
but many oceans have submarine
canyons running through them.
The deepest of these is the Mariana
Trench in the Pacific. At 35,829 ft
(10,920 m) deep, you could fit in
Mount Everest with room to spare.

Caribbean Sea
Average depth 4,960 ft (1,512 m)

(c) 2012 Dorling Kindersley. All Rights Reserved.(c) 2012 Dorling Kindersley. All Rights Reserved.
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