The Russian component of an Arctic Ice Sheet during the Last Glacial Maximum

Abstract

The extent of Late Weichselian glaciation in Arctic Russia remains a problem. Our model of 1995–1998 suggests a continuous and long-lived ice sheet centered on the Kara Sea. Other reconstructions suggest a smaller and “diachronous” glaciation. The vast majority of dates support the model of restricted glaciation. We show that these dates are inconsistent with the geologic record of ice flow across the Kara-Barents divide, with second-order glacial geology of Kola Peninsula, and with evidence for glacial surges. They are also inconsistent with Late Weichselian climate of the Arctic, with Eurasian continental paleohydrology, including meltwater drainage systems, cataclysmic megafloods, major transgressions of the Caspian Sea, and with the entire paleogeographic context of northern Eurasia. We believe that, due to impeded ventilation of the Pleistocene Arctic Ocean, these dates are often too old, and that recycling and contamination of the samples would also contribute to the dating errors. Destructive impacts of late-glacial ice-sheet surges and megafloods upon the Arctic glacial sequences would also aggravate the situation. By ignoring the dates until these problems are addressed, we find that the field evidence supports continuous glaciation of Arctic Russia at the LGM, and that the resulting ice sheet was part of an Arctic Ice Sheet that included an ice shelf in the Arctic Ocean and ice sheets in Greenland and North America. We present 3-D reconstructions of the Arctic Ice Sheet and, with an enlarged Antarctic Ice Sheet, we show that the ice volume is equivalent to an LGM sea level that was 130–135 m lower than at present. The reconstructions depict the Arctic Ice Sheet before and after massive thawing of the bed that allows partial gravitational collapse of the overlying ice, with a minimal change in ice volume.