The paleo Elbe River: 10.000 yrs after flooding
The submerged valley of the paleo Elbe River forms one of the most prominent structures of the German North Sea (~1.000 ha). The valley developed to its present form during the Weichselian sea-level lowstand (130 m below present). Melt waters that discharged in north-westerly directions along the Scandinavian Ice Sheet fed the paleo Elbe at that time. During the Holocene the valley drowned in the rising sea. We will present an area-wide high resolution map of the seafloor (~1,600 km²), high-resolution shallow seismic data and sediment coring data along the paleo Elbe River to explain historical process of sedimentary valley infill and coastal evolution with the successive Holocene sea level rise. At the eastern levee of the valley (which belongs to a nature conservation area) complex sequences of glacio-fluvial and sub-glacial deposits are still present at the seafloor surface. The glacial deposits, consisting mainly of coarse sediments (such as coarse sands, gravel and boulders) are a unique habitat of the otherwise sandy North Sea. The new backscatter map highlights a much higher heterogeneity and complexity in sediment and habitat distribution as assumed before. The presence of only relative thin and patchy Holocene marine fine sand layers indicates strong hydrodynamic processes. Shallow seismic data show the base of the paleo Elbe valley and conspicuous internal seismic reflectors above the base, inclined in northeastern direction. Core data indicate a change in current regime and the development from a terrigenous towards a marine environment.
HE > 420-439 > 436
HE > 420-439 > 438
HE > 420-439 > 439