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Deep water paleo‐iceberg scouring on top of Hovgaard Ridge–Arctic Ocean
Author(s) -
Arndt Jan Erik,
Niessen Frank,
Jokat Wilfried,
Dorschel Boris
Publication year - 2014
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2014gl060267
Subject(s) - geology , iceberg , oceanography , ridge , arctic , seafloor spreading , echo sounding , continental shelf , bathymetry , glacial period , ice shelf , continental margin , trough (economics) , ice sheet , sea ice , paleontology , cryosphere , macroeconomics , economics , tectonics
Abstract In multibeam echosounder and subbottom profiler data acquired during R/V 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 paleo‐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.