Lake Cheko

Infobox_lake
lake_name = Lake Cheko
coords = coord|60.964|N|101.86|E|type:waterbody_region:RU|display=inline,title
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basin_countries = Russia
location = near Podkamennaya Tunguska River, Siberia
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Lake Cheko is a small freshwater lake in Siberia, near the Podkamennaya Tunguska River. It is 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 Convert|2000|km2|sqmi|0|abbr=on of Siberian taiga.cite journal
last = Gasperini
first = L. "et al"
title = Geophysical/sedimentological study of a lake close to the epicenter of the great 1908 Siberian (Tunguska) Explosion
journal = NGF Abstracts and Proceedings
issue = 1
pages = 29–30
date = 2001
url = http://www-th.bo.infn.it/tunguska/GasperiniSvalbard.pdf
accessdate = 2008-05-27 ] 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, [cite journal
last = Florenskiy
first = K. P.
authorlink = Kirill Florensky
title = Preliminary results from the 1961 combined Tunguska meteorite expedition
journal = Meteoritica
volume = 23
pages = 3–29
date = 1963
url = http://abob.libs.uga.edu/bobk/tungmet.html
accessdate = 2007-06-26] but newer research suggests that only a meter or so of the sediment layer on the lake bed is "normal lacustrine sedimentation", indicating a much younger lake of about 100 years. [cite journal
last = Gasperini
first = L. "et al"
title = Reply - Lake Cheko and the Tunguska Event: impact or non-impact?
journal = Terra Nova
volume = 20
issue = 2
pages = 169–172
year = 2008
month = April
url = http://www.blackwell-synergy.com/doi/pdf/10.1111/j.1365-3121.2008.00792.x
doi = 10.1111/j.1365-3121.2008.00792.x
accessdate = 2008-05-27 ] 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.cite journal
last = Gasperini
first = L. "et al"
title = The Tunguska Mystery
journal = Scientific American
pages = 80–86
year = 2008
month = June
url = http://www.sciam.com/article.cfm?id=the-tunguska-mystery
accessdate = 2008-06-08 ] 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. Researchers from the University of Bologna intend to investigate the dense object, 10 meters below the lake bed, in 2009.cite web
last = Rincon
first = Paul
title = Fire in the sky: Tunguska at 100
news source = BBC News
url = http://news.bbc.co.uk/1/hi/sci/tech/7470283.stm
accessdate = 2008-07-01 ]

However, Gareth Collins and Phil Bland of 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.

References