Diapositiva 1

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Lake A body of (usually fresh) water surrounded
by land
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LAKES CLASSIFICATION Lakes are classified
depending on how they formed and on the quality
of the water (freshwater or saltwater). Only in
the saltiest lakes there is no life.
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1.Tectonic lakes. The movements of the Earth's
crust formed the largest lake, the Caspian Sea,
and the deepest, Lake Baikal. Caspian Sea is
located in a depression between the Caucasus
Mountains and Central Asia and its surface is
still varying, millions of years after its
emergence. 2.Volcanic lakes. The most common
form is the one filling the caldera of a shut-off
volcano. Some volcanic lakes form when the lava
seeps on the slopes, solidifying due to the cold
waters. 3.Glacial lakes appear following the
melting of the glaciers. They are more common in
the Northern Hemisphere Most lakes in the UK,
Finland (about 60,000 !) or Alps formed this way.

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4.Karstic lakes form in calcareous regions and
can be subterranean as well. Water dissolves the
limestone creating huge caves harboring rivers
and lakes. 5.Salt lakes. Most lakes contain
freshwater and are continuously supplied with
water from the exterior. If the supply of
freshwater is limited, minerals from the bottom
of the lakes can enter into the water's
composition and concentrate, turning the lake
salty. The Great Salt Lake from Utah formed this
way. The Caspian Sea and the Aral Sea are salty
too. INVESTIGATE WHERE ARE THEY 6.Artificial
lakes. The most common are reservoirs, like Lake
Nasser, formed through the interception of the
Nile, and Lake Mead (US), formed through the
interception of the Colorado River. They generate
hydroelectric power. Many artificial lakes serve
as water reservoirs, supplying water for
industries and home usage.
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HOMEWORK EXAMPLES OF LAKES NAME AND SITUATION
ON EARTH