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| Titel |
Are landscapes buffered to high-frequency climate change? A comparison of sediment fluxes and depositional volumes in the Corinth rift, central Greece, over the past 130 kyrs |
| VerfasserIn |
Stephen E. Watkins, Alexander C. Whittaker, Rebecca E. Bell, Lisa C. McNeill, Robert L. Gawthope |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250143315
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| Publikation (Nr.) |
 EGU/EGU2017-7022.pdf |
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| Zusammenfassung |
| Sediment supply is a fundamental control on the stratigraphic record. However, a key
question is the extent to which tectonics and climate affect sediment fluxes in time and space.
To address this question, estimates of sediment fluxes must be compared with measured
sediment volumes within a closed basin, for which the tectonic and climatic boundary
conditions are constrained.
The Corinth rift, Greece is one of the most actively extending basins on Earth, with
modern day extension rates of up to 15 mm/yr. The Gulf of Corinth is a closed system and
has periodically become a lake during marine lowstands over the late Pleistocene. We
estimated suspended sediment fluxes through time for rivers draining into the Gulf of
Corinth using an empirically-derived BQART method. WorldClim climate data,
palaeoclimate models and palaeoclimate proxies were used to estimate discharges and
temperatures over the last 130 ky. We used high-resolution 2D seismic surveys to interpret
three seismic units over this period and we used this data to derive independent
time series of basin sedimentary volumes to compare with our sediment input flux
estimates.
Our results predict total Holocene sediment fluxes into the Corinth Gulf of 20 km3, within
a factor of 2 of the measured sediment volume in the central depocentres over this
timescale. Sediment fluxes vary spatially around the Gulf, but imply catchment-averaged
erosion rates of 0.2 to 0.4 mm/yr. Moreover, BQART predicted sediment fluxes and
sedimentation rate measurements both indicate a 25% reduction during the last
glacial period compared to the Holocene. At the last glacial maximum mean annual
temperatures were lower by 5 degrees, although precipitation was similar, or lower,
than present. Consequently, our results demonstrate that sediment export to the
basin is sensitive to glacial-interglacial cycles. However, precipitation constraints
alone are insufficient to understand sediment flux sensitivity to climate change. |
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