C43A-0775
On the existence of an East Siberian-Chukchi ice sheet: New insights from the SWERUS-C3 Expedition 2014
Thursday, 17 December 2015
Poster Hall (Moscone South)
Martin Jakobsson1, Matt O'Regan1, Nina Kirchner2, Roman Ananiev3, Jan Backman4, Natalia Barrientos4, Denis Chernykh5, Helen Coxall1, Thomas M Cronin6, Andrey Koshurnikov7, Leopold Isaevich Lobkovsky8, Larry A Mayer9, Riko Noormets10, Francesco Muschitiello1, Nilsson Johan11, Christof Pearce1, Igor Peter Semiletov12 and Christian Stranne1, (1)Stockholm University, Department of Geological Sciences, Stockholm, Sweden, (2)Bert Bolin Center Climate Res, Stockholm, Sweden, (3)National Research Tomsk Polytechnic University, Tomsk, Russia, (4)Stockholm University, Stockholm, Sweden, (5)Pacific Oceanological Institute FEB RAS, Vladivostok, Russia, (6)U.S. Geological Survey, Reston, Virginia, USA, VA, United States, (7)Lomonosov Moscow State University, Moscow, Russia, (8)Institute of oceanology, Moscow, Russia, (9)University of New Hampshire Main Campus, Durham, NH, United States, (10)University Centre in Svalbard, Longyearbyen, Norway, (11)Stockholm University, Department of meteorology, Stockholm, Sweden, (12)University of Alaska Fairbanks, Fairbanks, AK, United States
Abstract:
The glacial history of the vast Siberian continental shelf of the Laptev and East Siberian Seas is poorly known. Most of this shelf area is shallower than 120 m implying that it was exposed land during the Last Glacial Maximum (LGM) as well as during older major Quaternary glaciations. The regional glacial and deglacial history of marine transgression has greatly influenced marine conditions of today’s Arctic Ocean continental shelves. For example, the present extent of submarine permafrost on the shallow continental shelves is tightly linked to the glacial history, because the submarine permafrost was formed during cold conditions when sea level was low enough for the shelves to be subaerially exposed. Conversely, one explanation for lack of submarine permafrost on some shelf areas is the presence of past ice sheets. Ice sheets extending over parts of the Eastern Siberian continental shelf have been proposed in literature during LGM as well as during older Quaternary glacial periods. However, the sparsely available data from the outer continental shelf and adjacent slope of the Eastern Siberian Arctic Ocean has left the glacial history in this part largely unresolved. Here we present new geophysical mapping and sediment coring data from the shallow East Siberian shelf and adjacent slope collected during the 2014 SWERUS-C3 expedition (SWERUS-C3: Swedish – Russian – US Arctic Ocean Investigation of Climate-Cryosphere-Carbon Interactions) with Swedish icebreaker Oden. The mapping, using multibeam sonar, chirp sub-bottom profiler, and electro magnetics, in combination with new sediment cores provide information on past glacial activities, sea-level history and permafrost extent on the Eastern Siberian Arctic Ocean. Combining the new SWERUS-C3 data with previous results from this region raises the question whether an East Siberian-Chukchi ice sheet existed during LGM and/or during older glacial periods.
