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

西伯利亚东北部弗兰格尔岛晚更新世冰川和海平面历史

• 批准号: 9906702
• 负责人: Patricia Anderson
• 金额: $ 45.33万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-04-01 至 2004-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9906702&HistoricalAwards=false
• 关键词: Late; Pleistocene; Glacial; Sea; Level

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).

末次冰盛期北极冰盖的范围和形态是第四纪历史上重要的遗失部分之一。北极冰川作用的范围和年代学对现代高纬度动植物的现代分布和组成起到了重要作用。没有一个冰盖比提议覆盖东西伯利亚海的冰盖更具争议性。一些冰川学家提出了第四纪晚期以海洋为基础的东西伯利亚冰盖(ESIS)的存在，并已用于古气候模型。然而，拟议中的冰盖东缘沿线的冰川地质只是表面上的调查。兰杰尔岛是进行此类调查的关键地区。对东西伯利亚海第四纪晚期条件的确认将有助于古气候模拟工作，并极大地提高我们对俄罗斯东部和西部冰盖范围差异的理解。主要调查人员将研究兰格尔岛的冰川历史，以提供第一批现场证据，以检验以下假设：1)兰格尔岛在末次盛冰期或更早期间被冰盖覆盖；2)兰格尔岛被发现，但位于ESIS的外围凹陷中；或3)兰格尔岛保持未冰川状态，可能除了有限的高山冰川。这些假说将通过使用放射性碳、气相色谱氨基酸、10Be、26A1和36C1宇宙成因同位素测年提供该地区的第一个辐射海平面和冰川年代学来验证。孢粉学分析将被用来评估变化，以解释晚第四纪植被和推断的气候。这项研究将对西伯利亚中部、西部和东北部不断增长的晚第四纪古环境研究数据库做出重大贡献。这项研究将有助于实现俄美北极陆架环境倡议(RAISE)的目标，也将满足其他国际项目的需要，如欧亚北部第四纪环境(Queen)和环-北极古环境(CAPE)。