The lake basin can be both endogenous and exogenous origin that have the most significant impact on their size, shape, water regime.
The largest lake basins of tectonic origin. They are located either in a simple tectonic structures in the basin in the plains (Ilmen, Chad) or in foothill and intermountain depressions (Balkhash), or in the grabens of the rift (Baikal, Nyasa, Tanganyika). But most of the major lake basin has a complex tectonic origin, in their education are involved as concave folds and breaks of the earth’s crust (Issyk-Kul lake. Victoria, etc.). All tectonic lakes are large in size and significant depth, and rift – an elongated and narrow shape in plan, very large depth, steep slopes. The bottoms of many deep lakes lie below the sea level, having a mirror above the water level, is cryptodepression (Baikal, Ladoga, etc.). In the location of tectonic lakes are observed certain regularities: they are concentrated along faults of the earth’s crust (the Syrian-African and Baikal rift zone), or framed panels: along the Canadian shield is a Large bear, Great Slave, Winnipeg, Athabasca, Great North American lakes; the Baltic shield along the Vyg, Segozero, Onega, Ladoga, etc.
The lakes occupy volcanic craters and calderas of extinct volcanoes or depressions in the surface of solidified lava flows (Kronotsky lake on the Kamchatka Peninsula, lake Java, Continue reading
Looking at a map, on all continents, you can see the lake. Some of them elongated, others rounded. Some lakes are located in mountainous areas, others on vast flat plains, some very deep and some very shallow. The shape and depth of the lake depend on the size of the basin which it occupies. Lake basins are formed by different ways.
Most of the major lakes of the globe is of tectonic origin. They are located in major deformations of the earth crust in the plains or fill the deep tectonic crack — rift (lake Baikal, Tanganyika, Nyasa, etc.).
Lake basins can become craters and calderas of extinct volcanoes, and sometimes depressions on the surface of lava flows. These lakes are called volcanic, are found, for example, on the Kuril and Japanese Islands, in Kamchatka, on the island of Java and in other volcanic regions of the Earth. It happens that the lava and fragments of igneous rocks dammed the river valley in this case also there is a volcanic lake.
The basin of the lake Kaali in Estonia is of meteoritic origin. It is located in the crater formed by the fall of a large meteorite.
Glacial lakes fill hollows formed as a result of the glacier activity. Moving, Continue reading
Lake Toba is the largest volcanic lake in the world and also the largest lake located in Sumatra
Lake Toba is in Northern Sumatra, about 45 kilometers from Berastagi at an altitude of 900 metres above sea level, about 200 km North of equator.
Lake Toba is a large – 100 kilometres long and 30 wide, but also deep – its depth is over 500 meters, so the Toba has the 11th place in the list of deepest lakes in the world.
For the first time, lake Toba has been described by the Dutchman Herman Neubronner van der Toucam, but because of his large size just through in 82 years, in 1929, it was identified as a Caldera.
Lake Toba was formed as a result of the most powerful in the last 25 million years of volcanic eruption that occurred about 73 thousand years ago.
The eruption of the SUPERVOLCANO Toba was incredible strength in the air has risen more than 2,800 cubic kilometers of volcanic rocks, more than 800 cubic kilometers of settled as ash.
Together with clouds of dust and ash was thrown up to three billion tons of sulfur dioxide. 20 000 square kilometers of land surface were destroyed in a moment.
The average temperature in the Northern hemisphere fell to 21 degrees. The population Continue reading