Lakes are formed as a result of running off of surface and underground water in deepenings, the hollow of various origin. These hollows are called pools, or hollows. They are replenished generally at the expense of the thawing snow and rains. Lakes are on all continents, in mountainous areas, on plains, the deepest and absolutely small. The form, the sizes and depth of lakes depend on origin of hollows. Lake hollows are formed in different ways.
Instruction
1. Tectonic the ozerabolshinstvo of large lakes has tectonic origin. They arise on sites of tectonic breaks, usually such lakes very deep, have the extended form. At slow lowering of sites of earth crust there were hollows of the Aral and Caspian seas lakes. The deepest in the world Lake Baikal was formed as a result of a deep crack. In similar tectonic breaks the North American Great Lakes were formed. One more example of the huge break is the East African rift system filled with a chain of lakes. The most known of them – Nyasa, Albert, Tanganyika, Edward. The same system possesses the most low-sited lake – the Dead Sea.
2. Volcanic ozeraozernym hollows happen craters of extinct volcanoes. Such lakes meet on the Japanese and Kuril Islands, on Kamchatka and Java Island. Sometimes the lava and fragments of rocks partition off the rivers, and in this case the volcanic lake appears too. For example, Lake Kivu on border of Rwanda and Zaire. These reservoirs quite deep, but small on the area.
3. Glacial to an ozeranaryad with lake hollows which were created by internal processes of Earth there is a set of the deepenings formed due to exogenous processes. Glacial lakes which filled the hollows formed by the movement of glaciers are most widespread. As a result of destructive activity of ancient glaciers the lakes of Karelia and Finland, numerous small lakes on slopes of mountains in the Alps, in the Caucasus and Altai were formed. These superficial lakes, wide, with islands.
4. Inundated ozerakotlovina of these lakes arose in valleys of the rivers. These are the remains of the old former course. Such reservoirs extended, twisting, small and superficial.
5. Lemon lakes These lakes were formed owing to separation from the sea of parts of the rivers by tongues of sand. They the extended form, superficial, are widespread in the south of Ukraine.
6. Karst lakes In the areas rich with limestones, dolomite, plasters, waters resulted from dissolution of these breeds karst lake hollows. Such lakes meet in the Crimea, in the Caucasus, the Urals.
7. Thermokarst ozerav to the tundra and a taiga, on sites of permafrost, during a warm season soil melts and sinks, forming small deepenings. So there are thermokarst lakes.
8. Artificial ozeraozerny hollows can be created artificially. The most known example of such lakes – reservoirs. Among the largest artificial reservoirs – the Lake Mid in the USA which appeared after closure of Colorado a dam and also the Lake Naser created by damming of the valley of Nile. All these lakes service hydroelectric power station. Also the set of such reservoirs is used for providing settlements with water. An example of artificial lakes are both decorative small park and garden lakes.