New insights on the glacial history of North-East Greenland from swath bathymetric data


Contact
Jan.Erik.Arndt [ at ] awi.de

Abstract

The present-day shape of the Greenland ice sheet represents its extent during an interglacial. Information on its past dynamic during glacials is preserved as submarine glacial features on the Greenland continental shelves. However, large areas of the continental shelves are unmapped or only poorly covered by bathymetric soundings. Hence, little is known on the extent and retreat of the ice after the Last Glacial Maximum (LGM) here. This is also the case for the North-East Greenland continental shelf. Here, the East Greenland Current is continuously exporting Arctic sea ice. In addition, in the Arctic winter large areas of landfast ice are developing at the coast and on shoals of the continental shelf that only seldom break up. These conditions make this area only hardly accessible to research vessels. Nevertheless, two studies based on single track lines of high resolution multibeam bathymetric data showed that Westwind Trough was covered by a fast flowing ice stream reaching at least to the middle shelf. Radiocarbon dating even suggested that probably the LGM ice extended to the shelf edge, but direct marine evidence was missing. We have investigated newly acquired and re-processed swath bathymetric data and sub-bottom profiler data from 19 cruises of RV Polarstern from 1985 until 2014 for glacial seafloor features. These features shed light on the past ice sheet configuration and LGM retreat. Amongst others, our study gives first marine evidence for ice stream activity in Norske Trough and in general a more intense ice streaming activity on the shelf. In addition, our data indicates that possibly a small separate ice sheet was present offshore the modern day Greenland coast.



Item Type
Conference (Poster)
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Primary Division
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Peer revision
Not peer-reviewed
Publication Status
Published
Event Details
ICAM, 02 Jun 2015 - 05 Jun 2015, Trondheim.
Eprint ID
37935
Cite as
Arndt, J. E. , Jokat, W. and Dorschel, B. (2015): New insights on the glacial history of North-East Greenland from swath bathymetric data , ICAM, Trondheim, 2 June 2015 - 5 June 2015 .


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