Response of the Antarctic Ice Sheet to the Last Great Global Warming

Hall/1643248该奖项支持一个项目，以重建东南极冰盖（罗斯冰盖）的一部分的行为，使用冰川地质测绘和放射性碳测年冰碛中所含的藻类沉积物，在末次冰期结束。这些结果将与其他测年方法进行比较，这些测年方法将用于末次盛冰期期间终止于南极洲东部皇家学会山脉山脉的高山冰川，其地貌与罗斯冰盖的地貌相交。这一比较的结果将有助于更好地了解结束上一个冰河时代的最近一次全球变暖期间的南极冰盖。这段时间很有趣，因为它将有助于我们了解南极冰盖在未来气候变暖中的行为。 这些数据还将有助于为模型提供信息，这些模型不仅试图模拟上一个冰河时代结束时冰盖的行为，而且还试图模拟其未来对大气二氧化碳浓度升高的反应。这项工作将有助于研究生和本科生的教育和培训，工作成果将纳入缅因州大学的课程。 研究结果将通过讲座和对K-12教室的访问向公众传播，该项目的数据将从缅因州大学网站以及公共数据库下载。南极冰盖对过去和未来全球海平面的变化起着关键性的控制作用，并对南半球乃至全球气候和海洋环流产生重要影响。然而，对冰盖在最后一次冰期循环中的演变以及导致其前进和后退的机制仍然缺乏完整的了解。特别令人感兴趣的是南极冰盖对结束上一个冰河时代的全球变暖的反应，因为它提供了关于未来冰盖在变暖气候下可能行为的重要线索。在这个项目中，科学家们将重建南极冰盖在罗斯海部分的最后一次冰期/间冰期过渡期间在南部皇家社会范围的岬角变薄的历史。他们将结合使用冰川地貌测绘和后退冰碛内藻类沉积物的放射性碳测年。最后，将把这一记录与铍和放射性碳年代测定年表进行比较，后者是关于邻近的独立高山冰川的年代测定，这些冰川在末次盛冰期终止于陆地，其沉积物与冰盖的沉积物有交叉关系。这一比较的结果将影响南极冰盖在最后一个冰河时代结束时的行为。这项工作将支助六名学生，包括至少三名本科生，并涉及在南极的实地工作。

Hall/1643248This award supports a project to reconstruct the behavior of a portion of the East Antarctic Ice Sheet (the Ross Ice Sheet), using glacial geologic mapping and radiocarbon dating of algal deposits contained in glacial moraines, at the end of the last glacial period. The results will be compared with other dating methods that will be used on alpine glaciers that terminated in the mountains of the Royal Society Range in East Antarctica during the last glacial maximum and whose landforms intersect with those of the Ross Ice Sheet. Results from this comparison will contribute to a better understanding of the Antarctic ice sheet during the most recent global warming that ended the last ice age. This period is of interest since it will help inform our understanding of Antarctic ice sheet behavior in a future climate warming. Such data also will help inform models that attempt to simulate not only the behavior of the ice sheet during the end of the last ice age, but also its future response to elevated atmospheric carbon dioxide. The work will contribute to the education and training of both graduate and undergraduate students and results from the work will be incorporated in classes at the University of Maine. Results derived from the research will be disseminated to the public through lectures and visits to K-12 classrooms and data from this project will be downloadable from a University of Maine web site, as well as from public data repositories. The Antarctic Ice Sheet exerts a key control on global sea levels, both past and future, and strongly influences Southern Hemisphere and even global climate and ocean circulation. And yet a complete understanding of the evolution of the ice sheet over the last glacial cycle and of the mechanisms that caused it to advance and retreat is still lacking. Of particular interest is the response of the Antarctic Ice Sheet to the global warming that ended the last ice age, because it yields important clues about likely future ice-sheet behavior under a warming climate. In this project, scientists will reconstruct the thinning history of the Antarctic Ice Sheet in the Ross Sea sector during the last glacial/interglacial transition on the headlands of the southern Royal Society Range. They will use a combination of glacial geomorphological mapping and radiocarbon dating of algal deposits enclosed within recessional moraines. Finally, this record will be compared with a beryllium- and radiocarbon-dated chronology that will be produced of adjacent independent alpine glaciers that terminated on land during the last glacial maximum and whose deposits show cross-cutting relationships with those of the ice sheet. Results from this comparison will bear on the behavior of the Antarctic Ice Sheet during the termination of the last ice age. This work will support six students, including at least three undergraduates, and involves field work in the Antarctic.