Elgygytgyn
| Elgygytgyn | ||
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| Geographical location | Chukchi Autonomous Okrug ( Russia ) | |
| Tributaries | around 50 small streams (many dry out in summer, all freeze through in winter) | |
| Drain | Enmywaam | |
| Data | ||
| Coordinates | 67 ° 30 ′ N , 172 ° 0 ′ E | |
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| Altitude above sea level | 492 m | |
| surface | 119 km² | |
| width | 12 km | |
| volume | 14.1 km³ | |
| Maximum depth | 169 m | |
| Catchment area | 293 km² | |
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particularities |
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| Age: approx. 3.6 million years Water temperature: max. 3.5 ° C in midsummer Ice thickness: approx. 2 m at the end of winter Visibility depth: 19 m, extremely oligotrophic |
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Elgygytgyn ( Chukchi Эльгыгытгын [ ˈɛɬɣəˌɣətɣən ] 'The White Lake', Russian Эльгыгы́тгын ) is a lake in Eastern Siberia . It is located on the Anadyr Plateau in the Chukchi Autonomous Okrug . The lake has a diameter of about twelve kilometers and is 169 meters deep. Its name refers to the long ice cover: the lake is covered with ice nine months a year. It is only ice-free from mid-July to October.
Emergence
The lake lies within a meteorite crater (impact structure) with a diameter of 18 kilometers. The meteorite impact occurred around 3.6 million years ago; H. at the turn of the lower to the middle Pliocene . The Elgygytgyn crater is therefore considered to be a comparatively young crater. As it is still very well preserved and relatively large, it was recognized as a meteorite crater in the 1970s, despite its remote location. Furthermore, Elgygytgyn is one of only two known impact craters on earth that were formed in volcanic rocks.
particularities
Although located north of the Arctic Circle , the lake was not covered by glaciers during the Ice Age , so that the lake sediments of Elgygytgyn form a climate archive that is valuable for science . This is currently being investigated as part of several research projects.
fauna
Another specialty of Elgygytgyn are its fish species. Two of them, Salvethymus svetovidovi and Salvelinus elgyticus , are endemic , so they only occur in this lake. The third naturally occurring species is Salvelinus boganidae or a close relative. The arctic char was also introduced a few years ago . This means that all fish in the lake are salmon fish .
The fish species in the lake are adapted to the very low temperatures of the water, which are usually just above freezing, and spend most of the year in complete darkness. The surface is frozen about 10 months a year. In summer the surface can melt, but in a few years the lake does not completely thaw.
literature
- Robert S. Dietz, John F. McHone: El'gygytgyn: Probably world's largest meteorite crater . In: Geology 4 (7), 1976, pp. 391-392, doi : 10.1130 / 0091-7613 (1976) 4 <391: EPWLMC> 2.0.CO; 2
- Martin Melles et al: The Lake El'gygytgyn Scientific Drilling Project - Conquering Arctic Challenges through Continental Drilling . In: Scientific Drilling 11/2011, pp. 29-40, doi : 10.2204 / iodp.sd. March 11, 2011 (PDF; 9.05 MB), accessed on May 11, 2013
Web links
- University of Cologne - project page of the climate research program (German / English)
- University of Fairbanks (English)
- Elgygytgyn in the Canadian database of impact structures (English)
- Information Elgygytgyn-drilling project (English)
- DFG Science TV: Polar Climate Archive - Video series about the drilling project at Elgygytgyn
Individual evidence
- ↑ a b Elgygytgyn in the State Water Register of the Russian Federation (Russian)
- ↑ a b Article Elgygytgyn in the Great Soviet Encyclopedia (BSE) , 3rd edition 1969–1978 (Russian)
- ↑ Dietz & McHone, 1976
- ^ Salvethymus svetovidovi in The IUCN Red List of Threatened Species . Retrieved April 29, 2013.
- ↑ Salvelinus elgyticus on FishBase . Retrieved April 29, 2013.
- ↑ Salvelinus boganidae in The IUCN Red List of Threatened Species . Retrieved April 29, 2013.
- ↑ Russia Unknown El'gygytgyn - Crater Lake in Chukotka