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| Titel |
Multivariate statistic and time series analyses of grain-size data in quaternary sediments of Lake El'gygytgyn, NE Russia |
| VerfasserIn |
A. Francke, V. Wennrich, M. Sauerbrey, O. Juschus, M. Melles, J. Brigham-Grette |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1814-9324
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| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 9, no. 6 ; Nr. 9, no. 6 (2013-11-05), S.2459-2470 |
| Datensatznummer |
250085254
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| Publikation (Nr.) |
 copernicus.org/cp-9-2459-2013.pdf |
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| Zusammenfassung |
| Lake El'gygytgyn, located in the Far East Russian Arctic, was
formed by a meteorite impact about 3.58 Ma ago. In 2009, the International
Continental Scientific Drilling Program (ICDP) at Lake
El'gygytgyn obtained a continuous sediment sequence of the
lacustrine deposits and the upper part of the impact breccia. Here, we
present grain-size data of the past 2.6 Ma. General downcore grain-size
variations yield coarser sediments during warm periods and finer ones during
cold periods. According to principal component analysis (PCA), the
climate-dependent variations in grain-size distributions mainly occur in the
coarse silt and very fine silt fraction. During interglacial periods,
accumulation of coarser material in the lake center is caused by
redistribution of clastic material by a wind-induced current pattern during
the ice-free period. Sediment supply to the lake is triggered by the
thickness of the active layer in the catchment and the availability of water
as a transport medium. During glacial periods, sedimentation at Lake
El'gygytgyn is hampered by the occurrence of a perennial
ice cover, with sedimentation being restricted to seasonal moats and vertical
conduits through the ice. Thus, the summer temperature predominantly
triggers transport of coarse material into the lake center. Time series
analysis that was carried out to gain insight into the frequency of the
grain-size data showed variations predominately on 98.5, 40.6, and
22.9 kyr oscillations, which correspond to Milankovitch's
eccentricity, obliquity and precession bands. Variations in the relative
power of these three oscillation bands during the Quaternary suggest that
sedimentation processes at Lake El'gygytgyn are dominated by
environmental variations caused by global glacial–interglacial variations
(eccentricity, obliquity), and local insolation forcing and/or latitudinal
teleconnections (precession), respectively. |
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