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| Titel |
Major dust events in Europe during marine isotope stage 5 (130-74 ka): a climatic interpretation of the "markers" |
| VerfasserIn |
D.-D. Rousseau, M. Ghil, G. Kukla, A. Sima, P. Antoine, M. Fuchs, C. Hatté, F. Lagroix, M. Debret, O. Moine |
| 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. 5 ; Nr. 9, no. 5 (2013-09-26), S.2213-2230 |
| Datensatznummer |
250085226
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| Publikation (Nr.) |
 copernicus.org/cp-9-2213-2013.pdf |
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| Zusammenfassung |
At present, major dust storms are occurring at mid-latitudes in the Middle
East and Asia, as well as at low latitudes in Northern Africa and in
Australia. Western Europe, though, does not experience such dramatic climate
events, except for some African dust reaching it from the Sahara. This
modern situation is of particular interest, in the context of future climate
projections, since the present interglacial is usually interpreted, in this
context, as an analog of the warm Eemian interval. European terrestrial
records show, however, major dust events during the penultimate interglacial
and early glacial. These events are easily observed in loess records by
their whitish-color deposits, which lie above and below dark chernozem
paleosols in Central European records of Marine Isotope Stage (MIS) 5 age.
We describe here the base of the Dolni Vestonice (DV) loess sequence, Czech
Republic, as the reference of such records. The dust is deposited during
intervals that are characterized by poor vegetation – manifested by high
δ13C values and low magnetic susceptibility – while the fine
sand and clay in the deposits shows grain sizes that are clearly different
from the overlying pleniglacial loess deposits. Some of these dust events
have been previously described as "Markers" or Marker Silts (MS) by one of
us (G. Kukla), and are dated at about 111–109 ka and 93–92 ka, with a
third and last one slightly visible at about 75–73 ka. Other events
correspond to the loess material of Kukla's cycles, and are described as
eolian silts (ES); they are observed in the same DV sequence and are dated
at about 106–105 ka, 88–86 ka, and 78.5–77 ka. These dates are determined
by considering the OSL ages with their errors measured on the studied
sequence, and the comparison with Greenland ice-core and European speleothem
chronologies.
The fine eolian deposits mentioned above, MS as well as ES, correspond to
short events that lasted about 2 ka; they are synchronous with re-advances
of the polar front over the North Atlantic, as observed in marine sediment
cores. These deposits also correlate with important changes observed in
European vegetation. Some ES and MS events appear to be coeval with
significant dust peaks recorded in the Greenland ice cores, while others are
not. This decoupling between the European eolian and Greenland dust
depositions is of considerable interest, as it differs from the fully
glacial situation, in which the Eurasian loess sedimentation mimics the
Greenland dust record. Previous field observations supported an
interpretation of MS events as caused by continental dust storms. We show
here, by a comparison with speleothems of the same age found in the northern
Alps, that different atmospheric-circulation modes seem to be responsible
for the two categories of dust events, MS vs. ES. |
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