The Late Pleistocene Glacial And Sea Level History of Wrangel Island, Northeast Siberia

点击翻译按钮获取中文摘要

AbstractOPP-9906702The extent and configuration of the Arctic ice sheet during the Last Glacial Maximum (LGM) is one of the critical missing pieces in Quaternary history. The extent and chronology of glaciation in the Arctic has played a significant role in shaping the modern distribution and composition of modern high latitude flora and fauna. No ice sheet has been more controversial than the one proposed to cover the East Siberian Sea. The presence of a marine-based East Siberian Ice Sheet (ESIS) during the late Quaternary has been suggested by some glaciologists and has been used in paleoclimate models. However, the glacial geology along the proposed ice sheet's eastern margin has only been superficially investigated. Wrangel Island is the key region for such an investigation. Confirmation of the late Quaternary conditions of the East Siberian Sea would aid paleoclimate modeling efforts and greatly improve our understanding of differences in ice extent between the eastern and western Russian Arctic.The Principal Investigators will study the glacial history of Wrangel Island to provide the first field evidence to test the following hypotheses: 1) Wrangel Island was covered by an ice sheet covered during the LGM or earlier; 2) Wrangel Island was uncovered, but lay in the peripheral depression of an ESIS; or 3) Wrangel Island remained unglaciated, except perhaps for limited alpine glaciation. These hypotheses will be tested by providing the first radiometric sea-level and glacial chronologies for this region by using radiocarbon, gas chromatography amino acid, 10Be, 26A1, and 36C1 cosmogenic isotope dating. Palynological analysis to assess variations will be used to interpret Late Quaternary vegetation and inferred climates. This research should contribute a significantly to a growing database of Late Quaternary paleoenvironmental studies in central, western and northeast Siberia. This research will fufill the Russian-American Initiative on Shelf-Land Environments in the Arctic (RAISE) goals and will also meet the needs of other international programs, such as Quaternary Environment of the Eurasian North (QUEEN)and Circum-Arctic Paleo-Environments (CAPE).