On our planet, there is a huge number of lakes.They can differ dramatically from one another both in size, origin and other indicators.Then what are they similar, and that the lake is at all?
give a precise definition of this concept is not so simple.For example, if you say that this is a pond, surrounded on all sides by land, it is not quite correct.Since those who fall in the river (or are derived from them), the coastline is broken.
If you claim that it is fresh water source, what of the Dead Sea and the other in which the water is salty?You can say that they have no connection with the oceans.But we know all the lake of Maracaibo, located in South America, is connected to the Caribbean Sea.
So nevertheless that such a lake?The right thing would be to say that it is a naturally occurring body of water on land.The first lake together different sizes.Sometimes it can be found in the mountains small, long only a few dozen meters, while the largest lake in the world - the Caspian Sea - has a length of over 1,000 kilometers.
The lake drains rainwater, they fall into rivers and streams, so they should be in the low points of the area.But this is not always the case.South American Lake Titicaca is located at an altitude of 3812 meters above sea level.
How are they formed
To understand what a lake, it is necessary to find out how they arise.There are glacial reservoirs are located in the basins of the earth surface, formed under a huge weight of an ancient glacier.These grooves gradually filled by glacial melt waters.Most often, they are placed in large groups, are small in size and depth.There are many in Finland, Canada and Siberia.
Mountain lakes located in the highland basins.Sometimes it happens that there is a lake in front of - when rock falls is partitioned the river bed and the water accumulates near the dam occurred.Usually they are short-lived, and the water is rapidly eroding barrier, but there are exceptions.An example is the Lake Sarez in the Pamir.
Lakes formed in the crustal faults, elongated, narrow and very deep.There are many in Africa, Tanganyika, Nyasa and others.Such is the deepest lake in the world Baikal.
Reservoirs tectonic origin and may have a small depth, for example Chmielewski lakes, which are located in the eastern part of the range Achishkho.Four drainage pond filled with fresh water in them does not run a single stream, and does not follow too.
Alpine lakes filled with glacial water, there are only fresh.But the Dead Sea, located in a valley, so salty that it there is no life.
Some lakes water due to the presence of large amounts of impurities in the composition can not only salt but turbid, which gives it a different color.But most of the water bodies, especially small in size, have a fresh and clean water.For example, in the Leningrad region is Lake Nameless, which is considered one of the cleanest in Russia.The reason for this is the presence of a large number of springs and the keys are constantly updating and refreshing water.
Some of the lakes are regularly changing their sizes, and maps of the coastline is designated conditionally.In most cases it depends on seasonal rainfall.For example, Lake Chad on the African continent during the year may change several times.
