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

霍尔/1643248该奖项支持一个重建南极东部冰盖(罗斯冰盖)一部分行为的项目，该项目使用冰川地质测绘和对上一次冰期结束时冰川冰雹中的藻类沉积进行放射性碳测年。这一结果将与其他将用于高山冰川的测年方法进行比较，这些高山冰川在上一次冰川高峰期终止于东南极皇家学会山脉的山脉，其地貌与罗斯冰盖的地貌相交。这种比较的结果将有助于更好地了解南极冰盖在最近一次全球变暖期间的情况，这场变暖结束了上一次冰河时代。这段时间很有意义，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。这样的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，而且还试图模拟它未来对大气中二氧化碳浓度上升的反应。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堂。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的网站和公共数据库下载。南极冰盖对全球海平面的过去和未来都起着关键的控制作用，并强烈影响着南半球乃至全球气候和海洋环流。然而，对上一次冰川周期中冰盖的演变以及导致冰盖进退的机制仍然缺乏完整的了解。尤其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，因为它为气候变暖下未来冰盖可能的行为提供了重要线索。在这个项目中，科学家们将重建在罗斯海地区的南极冰盖变薄的历史，在最后一次冰川/间冰期过渡期间，在皇家学会山脉南部的海角。他们将结合使用冰川地貌测绘和对衰退冰雹中藻类沉积物的放射性碳测年。最后，这一记录将与铍和放射性碳年代测定的年代学进行比较，该年代学将由相邻的独立高山冰川产生，这些冰川在上一次冰盛期终止于陆地上，其沉积与冰盖的沉积显示出横切关系。这一比较的结果将对南极冰盖在上一个冰期结束时的行为产生影响。这项工作将支持六名学生，其中至少包括三名本科生，并涉及到南极的实地工作。

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.