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| Titel |
Spatial distribution of Pleistocene/Holocene warming amplitudes in Northern Eurasia inferred from geothermal data |
| VerfasserIn |
D. Y. Demezhko, D. G. Ryvkin, V. I. Outkin, A. D. Duchkov, V. T. Balobaev |
| 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 ; 3, no. 3 ; Nr. 3, no. 3 (2007-09-13), S.559-568 |
| Datensatznummer |
250001082
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| Publikation (Nr.) |
 copernicus.org/cp-3-559-2007.pdf |
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| Zusammenfassung |
| We analyze 48 geothermal estimates of Pleistocene/Holocene warming
amplitudes from various locations in Greenland, Europe, Arctic regions of
Western Siberia, and Yakutia. The spatial distribution of these estimates
exhibits two remarkable features. (i) In Europe and part of Asia the
amplitude of warming increases toward the northwest and displays clear
asymmetry with respect to the North Pole. The region of maximal warming is
close to the North Atlantic. A simple parametric dependence of the warming
amplitudes on the distance to the warming center explains 91% of the
amplitude variation. The Pleistocene/Holocene warming center is located
northeast of Iceland. We claim that the Holocene warming is primarily
related to the formation (or resumption) of the modern system of currents in
the North Atlantic. (ii) In Arctic Asia, north of the 68-th parallel, the
amplitude of temperature change sharply decreases from South to North,
reaching zero and even negative values. These small or negative amplitudes
could be attributed partially to a joint influence of Late Pleistocene ice
sheets. Using a simple model of the temperature regime underneath the ice
sheet we show that, depending on the relationship between the heat flow and
the vertical ice advection velocity, the base of the glacier can either warm
up or cool down. Nevertheless, we speculate that the more likely explanation
of these observations are warm-water lakes thought of have formed in the
Late Pleistocene by the damming of the Ob, Yenisei and Lena Rivers. |
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