Late-Weichselian ice sheets in Arctic and Pacific Siberia

Abstract

Abstract Interpretation of Space images coupled with field data on glacial geomorphology and glacial geology of Northern Eurasia have provided compelling evidence for a continuous Late Weichselian ice sheet covering the entire Arctic margin of the continent. In addition to the Scandinavian ice sheet, three ice sheets of the same order — the Karan, East Siberian and Beringian — are identified within the major Eurasian ice sheet. Also, there is evidence and other considerations suggesting a former ice sheet in the Sea of Okhotsk. Ice-spreading centers of the ice sheets were situated on the continental shelves off the Siberian coasts, thus we can term the ice sheets ‘Siberian’. So far, the conventional stratigraphic approach to the problem of Siberian glaciation has proven fruitless and yielded nothing but uncertainty, while geomorphological studies have discovered a wealth of glacial landforms in Arctic Siberia. It was these landforms and their spacing that made the existence of former Siberian ice sheets evident. The East Siberian ice sheet rested on the shelves of the eastern Laptev and East Siberian Seas, and its flow was directed radially, including up the Yana and Indigirka Rivers. The Beringian ice sheet was grounded on the Chukchi-, Bering-, and Beaufort Sea shelves, overriding the Chukchi and Seward Peninsulas from the north and flowing through the Bering Strait. It was continued by a thick floating ice shelf buttressed by the submarine Aleutian-Commander Ridge. The Okhotsk ice sheet was grounded on the Okhotsk shelf. Specific gemorphic signatures of marine ice sheets — the ‘glacially cut corners’ — have been identified on all promontories jutting out into the Bering and Okhotsk Seas. The Beringian and Okhotsk ice sheets are consistent with the results of deep-sea drilling in the adjacent North Pacific during Leg 145 of D/V JOIDES Resolution.