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| Titel |
Seasonal flood layer distribution of the last 450 years in annually laminated sediment from Lake Ammersee (Southern Germany) |
| VerfasserIn |
M. Czymzik, A. Brauer, P. Dulski, B. Plessen, R. Naumann, J. Zimmermann, U. v. Grafenstein |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250026386
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| Zusammenfassung |
| Lakes can be utilized as long-term natural observatories of environmental and climate change
in the human habitat because they act as ideal sediment traps accumulating continuous
sediment records reaching far back in time. Especially from annually laminated lake sediment
records detailed seasonal information can be obtained. Such long time series of
high-resolution data ideally complement multi-scale observational data in order to
achieve a comprehensive mechanistic understanding of climate and environmental
variability.
For this case study two short annually laminated sediment cores from Lake Ammersee
(Southern Germany) have been studied using a combination of micro-facies analyses, high
resolution element scanning (μ-XRF) and stable isotope (δ13C, δ18O) data. Our results
provide a precise and independent chronology established by counting of calcite varves using
a petrographic microscope and the identification of short-term fluxes of detrital matter into
the lake. The seasonal occurrence of these detrital layers was determined by their
micro-stratigraphic position within a varve. The record of detrital layers within the last 73
years is in good agreement with observed runoff data from the main tributary river (Ammer)
and local precipitation data. This leads in combination with a proximal-distal pattern
of detrital layer thicknesses to an interpretation as flood layers. Our data indicate
maxima of spring and summer flood layers during solar minima in the Little Ice
Age triggered by intensified snowmelt events and atmospheric circulation changes. |
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