Feldens, P., Diesing, M., Wilken, D., Schwarzer, K.
Submarine eskers preserved on Adler Grund, south-western
Baltic Sea
The position of offshore ice margins, especially in the
Baltic Sea, is poorly known. Based on hydroacoustic surveys, we mapped a field
of submarine eskers on the seafloor of the shoal Adler Grund, southwestern
Baltic Sea. The eskers comprise discontinuous, branching ridge structures with
zigzag-shaped crests. These features are elevated up to 7 m above the
surrounding seafloor with slope angles approaching 26o. The ridges are composed
of gravel and boulders. Their interpretation as glacio-tectonic features is
unlikely due to branching ridge crests and a continuous reflector at the base
of several ridges. Based on their morphology and distribution, the ridges are
interpreted as concertina eskers formed by meltwater outbursts close to an ice
margin. Their good state of preservation indicates that the eskers were most
likely formed during the last advance of the Weichselian glaciation across the
study region.