Lake Cheko
Encyclopedia
Lake Cheko is a small freshwater
lake
in Siberia
, near the Podkamennaya Tunguska River
, in what is now the Evenkiysky District of the Krasnoyarsk Krai
. It is a small bowl shaped lake, 708 m long, 364 m wide and about 50 m deep.
Scientists have speculated that Lake Cheko was created during the Tunguska event
, an explosion on 30 June 1908 that destroyed more than 2000 km² (772.2 sq mi) of Siberian taiga
. It is suggested that the lake, which lies approximately 8 kilometres north-north-west of the event hypocenter
, was formed by a fragment which struck the ground.
A 1961 investigation estimated the age of the lake to be at least 5000 years, based on meters-thick silt
deposits on the lake bed;
newer research suggests that only a meter or so of the sediment layer on the lake bed is "normal lacustrine
sediment
ation", indicating a much younger lake of about 100 years.
Acoustic-echo soundings of the lake floor provide further support for the hypothesis, revealing a conical shape for the lake bed, which is consistent with an impact crater. Also, the lake's long axis points to the epicenter
of the Tunguska explosion, about 7.0 km away.
Magnetic readings also indicate a possible meter-sized chunk of rock below the lake's deepest point, which may be a fragment of the colliding body. However, researchers at Imperial College London
, point out that many of the trees surrounding the lake are older than 100 years, which suggests that the lake could not have been created by an impact in 1908.
Researchers from the University of Bologna
investigated the lake bed in 2009. Studies of sediments, isotopes and pollen, in their opinion, "suggest that Lake Cheko formed at the time of the Tunguska Event."
Fresh Water
Fresh Water is the debut album by Australian rock and blues singer Alison McCallum, released in 1972. Rare for an Australian artist at the time, it came in a gatefold sleeve...
lake
Lake
A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...
in Siberia
Siberia
Siberia is an extensive region constituting almost all of Northern Asia. Comprising the central and eastern portion of the Russian Federation, it was part of the Soviet Union from its beginning, as its predecessor states, the Tsardom of Russia and the Russian Empire, conquered it during the 16th...
, near the Podkamennaya Tunguska River
Podkamennaya Tunguska River
The Podkamennaya Tunguska is a river in Krasnoyarsk Krai, Russia; it is an eastern tributary of the Yenisei and has a length of . The name of the river comes from the fact that it flows under pebble fields without open water...
, in what is now the Evenkiysky District of the Krasnoyarsk Krai
Krasnoyarsk Krai
Krasnoyarsk Krai is a federal subject of Russia . It is the second largest federal subject after the Sakha Republic, and Russia's largest krai, occupying an area of , which is 13% of the country's total territory. The administrative center of the krai is the city of Krasnoyarsk...
. It is a small bowl shaped lake, 708 m long, 364 m wide and about 50 m deep.
Scientists have speculated that Lake Cheko was created during the Tunguska event
Tunguska event
The Tunguska event, or Tunguska blast or Tunguska explosion, was an enormously powerful explosion that occurred near the Podkamennaya Tunguska River in what is now Krasnoyarsk Krai, Russia, at about 7:14 a.m...
, an explosion on 30 June 1908 that destroyed more than 2000 km² (772.2 sq mi) of Siberian taiga
Taiga
Taiga , also known as the boreal forest, is a biome characterized by coniferous forests.Taiga is the world's largest terrestrial biome. In North America it covers most of inland Canada and Alaska as well as parts of the extreme northern continental United States and is known as the Northwoods...
. It is suggested that the lake, which lies approximately 8 kilometres north-north-west of the event hypocenter
Hypocenter
The hypocenter refers to the site of an earthquake or a nuclear explosion...
, was formed by a fragment which struck the ground.
A 1961 investigation estimated the age of the lake to be at least 5000 years, based on meters-thick silt
Silt
Silt is granular material of a size somewhere between sand and clay whose mineral origin is quartz and feldspar. Silt may occur as a soil or as suspended sediment in a surface water body...
deposits on the lake bed;
newer research suggests that only a meter or so of the sediment layer on the lake bed is "normal lacustrine
Lake
A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...
sediment
Sediment
Sediment is naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particle itself....
ation", indicating a much younger lake of about 100 years.
Acoustic-echo soundings of the lake floor provide further support for the hypothesis, revealing a conical shape for the lake bed, which is consistent with an impact crater. Also, the lake's long axis points to the epicenter
Epicenter
The epicenter or epicentre is the point on the Earth's surface that is directly above the hypocenter or focus, the point where an earthquake or underground explosion originates...
of the Tunguska explosion, about 7.0 km away.
Magnetic readings also indicate a possible meter-sized chunk of rock below the lake's deepest point, which may be a fragment of the colliding body. However, researchers at Imperial College London
Imperial College London
Imperial College London is a public research university located in London, United Kingdom, specialising in science, engineering, business and medicine...
, point out that many of the trees surrounding the lake are older than 100 years, which suggests that the lake could not have been created by an impact in 1908.
Researchers from the University of Bologna
University of Bologna
The Alma Mater Studiorum - University of Bologna is the oldest continually operating university in the world, the word 'universitas' being first used by this institution at its foundation. The true date of its founding is uncertain, but believed by most accounts to have been 1088...
investigated the lake bed in 2009. Studies of sediments, isotopes and pollen, in their opinion, "suggest that Lake Cheko formed at the time of the Tunguska Event."