Lake - a natural water bodies resulting from filling with water the land depressions.
Causes of these recesses and methods of filling them with water may be different, however, there are several types of lakes.
Most of the large lakes on the planetIt was the result of tectonic processes in the earth's crust. As a result of plate motion and earthquake cracks in the earth's crust and its deflections. In these recesses, and water accumulates. For example, the Onega Lake is located in the basin, and Lake Baikal in a huge tectonic fissure.
Volcanic lakes are usually formed in the cratersextinct volcanoes. There are many lakes in areas of high volcanic activity - in Kamchatka, Japan. Also referred to as volcanic lakes, which are formed in places where the frozen lava of volcano izvergnuvshayasya, partition off the river bed.
In the northern regions of the earth are many glacial lakes. Their hollow formed by the movement of glaciers, which was pressed top layer of soft ground and left after leaving a decrease in relief. In the mountains, lakes and glaciers are due, which, melting, leaving behind a moraine - a mixture of sand, stones and earth. It can block the mountain river, with the result that the lake formed. Mountain lakes are also formed as a result of landslides, when the stones block the riverbed.
In areas where the crust is composed of gypsum,dolomite and limestone, the water can erode the rock, as a result of underground voids are formed - caves, which can be filled with water. So there is a big part of the underground lakes.
In areas of permafrost soil can sink when the summer thaw, resulting in formation of small lakes.
Some lakes are formed near the seacoast where sand spit separates the shallow portion of the sea, such lakes are called lagoons. If the sand bar separates the section of the river, the lake is also formed, but it is called the estuary.
Sometimes, the river bed is too curved, but it happens gradually flattening, and the curved portion is on the side of the channel, that is, there is a lake called the bayou.