Evaluating the Last Glacial Maximum Ice-Sheet Extent in the Northen Kara Sea and its Effect on the Siberian River Drainage.

Polyak 0221468首席研究员将调查喀拉海北方第四纪沉积物的地层学和形态学，以划定末次盛冰期（LGM）期间欧亚北极边缘的冰盖界限。 这将测试是否大量的西西伯利亚河流被喀拉海大陆架上的冰阻塞，从而阻止流入北冰洋。他将根据地震反射数据进行研究，包括火花，海底声纳和侧扫声纳记录以及从喀拉海北方收集的沉积物岩心。 对这些数据的预先评价揭示了一个复杂的系统，由冰川沉积物、河流网络、低海平面期间延伸到大陆架和冰前/前三角洲盆地组成。 对这些数据进行详细调查，最好在2003年进行更多的横断面调查，并将其与邻近陆地地区的冰川地质结果进行比较，将使他们能够回答在末次冰期期间巴伦茨-卡拉冰盖是否扩展到整个北方卡拉海。建立详细的数字测深和地震地层模型，并确定沉积物芯材料的年龄和沉积环境。由此产生的产品将包括地层控制的三维地形模型或冰碛沉积物、相邻的沉积盆地和主要的古河道。 侧扫数据将提供关于海底结构的更多信息。 这些结果将提供必要的边界条件模拟欧亚北极的古水文末次冰期循环。 生成的有关冰盖边缘配置以及冰川侵蚀和沉积特征分布的数据将有助于了解北方欧亚大陆冰川发育的模式以及北冰洋冰架的潜在作用。 此外，生成的测深网格模型将改进北极国际测深数据库。

Polyak0221468The Principal Investigator will investigate the stratigraphy and morphology of Quaternary deposits in the northern part of the Kara Sea in order to delineate the ice-sheet limits at the Eurasian Arctic margin during the Last Glacial Maximum (LGM). This will test whether voluminous West Siberian rivers were dammed by the ice on the Kara Sea continental shelf and thus, prevented from discharging into the Arctic Ocean.He will conduct a study based on seismic-reflection data, including sparker, subbottom sonar and sidescan sonar records and sediment cores collected from the northern Kara Sea. A pre-evaluation of these data reveals a complex system of glacigenic deposits, riverine networks, extended on the shelf during low sea level and proglacial/prodeltaic basins. A detailed investigation of these data, preferably supplemented by additional transects to be run in 2003, and their comparison with glacial-geological results from adjacent land areas will allow them to answer whether the Barents-Kara ice sheet expanded across the entire northern Kara Sea during the LGM.This study will involve processing and interpretation of seismic-reflection records, construction of detailed digital bathymetric and seismo-stratigraphic models and determination of age and depositional environments of sediment-core material. The resulting products will include stratigraphically-controlled, three-dimensional terrain models or morainic deposits, adjacent depositional basins, and major paleo-river channels. Sidescan data will provide additional information on seafloor texture. These results will provide necessary boundary conditions for modeling the paleohydrology of the Eurasian Arctic for the last glacial cycle. Generated data on the configuration of the ice-sheet margin and the distribution of glacigenic erosional and sedimentary features will help understand the patterns of glacial development in northern Eurasia and the potential role of ice shelves in the Arctic Ocean. In addition, generated bathymetric grid models will improve the international bathymetric data base for the Arctic.