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| Titel |
Precipitation as the main driver of Neoglacial fluctuations of Gualas glacier, Northern Patagonian Icefield |
| VerfasserIn |
S. Bertrand, K. A. Hughen, F. Lamy, J.-B. W. Stuut, F. Torrejón, C. B. Lange |
| 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 ; 8, no. 2 ; Nr. 8, no. 2 (2012-03-15), S.519-534 |
| Datensatznummer |
250005466
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| Publikation (Nr.) |
 copernicus.org/cp-8-519-2012.pdf |
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| Zusammenfassung |
| Glaciers are frequently used as indicators of climate change. However, the
link between past glacier fluctuations and climate variability is still
highly debated. Here, we investigate the mid- to late-Holocene fluctuations
of Gualas Glacier, one of the northernmost outlet glaciers of the Northern
Patagonian Icefield, using a multi-proxy sedimentological and geochemical
analysis of a 15 m long fjord sediment core from Golfo Elefantes, Chile, and
historical documents from early Spanish explorers. Our results show that the
core can be sub-divided into three main lithological units that were
deposited under very different hydrodynamic conditions. Between 5400 and
4180 cal yr BP and after 750 cal yr BP, sedimentation in Golfo Elefantes was
characterized by the rapid deposition of fine silt, most likely transported
by fluvio-glacial processes. By contrast, the sediment deposited between
4130 and 850 cal yr BP is composed of poorly sorted sand that is free of
shells. This interval is particularly marked by high magnetic susceptibility
values and Zr concentrations, and likely reflects a major advance of Gualas
glacier towards Golfo Elefantes during the Neoglaciation. Several thin silt
layers observed in the upper part of the core are interpreted as secondary
fluctuations of Gualas glacier during the Little Ice Age, in agreement with
historical and dendrochronological data. Our interpretation of the Golfo
Elefantes glaciomarine sediment record in terms of fluctuations of Gualas
glacier is in excellent agreement with the glacier chronology proposed for
the Southern Patagonian Icefield, which is based on terrestrial (moraine)
deposits. By comparing our results with independent proxy records of
precipitation and sea surface temperature, we suggest that the fluctuations
of Gualas glacier during the last 5400 yr were mainly driven by changes
in precipitation in the North Patagonian Andes. |
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