Publication Date:
2014-06-04
Description:
In multibeam echosounder and sub-bottom profiler data acquired during RV Polarstern cruise ARK-VII/3a from the Hovgaard Ridge (Fram Strait), we found evidence for very deep (〉1200 m) iceberg scouring. Five elongated seafloor features have been detected that are interpreted to be iceberg scours. The scours are oriented in north-south/south-north direction and are about 15 m deep, 300 m wide, and 4 km long crossing the entire width of the ridge. They are attributed to multiple giant palaeo-icebergs that most probably left the Arctic Ocean southward through Fram Strait. The huge keel-depths are indicative of ice sheets extending into the Arctic Ocean being at least 1200 m thick at the calving front during glacial maxima. The deep St Anna Trough or grounded ice observed at the East Siberian Continental Margin are likely source regions of these icebergs that delivered freshwater to the Nordic Seas.
Print ISSN:
0094-8276
Electronic ISSN:
1944-8007
Topics:
Geosciences
,
Physics
