A GIS database and Map of Marine and Terrestrial Glacial Features Related to Mid- to Late-Pleistocene Arctic Ocean Glaciation

北极现在处于气候变化的前沿，因为地表气温变暖的速度是地球仪其他地区的两倍。海冰覆盖面积的空前减少正将北极推向未知的境地。冰冻圈中最重要的组成部分是高纬度冰川，它们拥有世界上99%以上的淡水。这些冰川本质上是不稳定的，因此对气候变化很敏感。我们可以研究冰川系统在过去是如何应对气候变化的，以更好地了解未来的冰川动态，并限制未来冰川对海平面上升的影响。越来越多的证据表明，在过去的13万年里，一个厚厚的冰盖可能多次跨越北冰洋。该项目旨在汇集来自北冰洋和周围沿海平原的各种地质证据，以探索更新世中期至晚期北冰洋冰川作用的时间和范围。这项研究将帮助我们更好地了解过去是否存在北冰洋宽的冰盖，这反过来又将帮助我们更好地了解未来冰盖的变化。高纬度的冰盖和冰架在了解未来冰川动态方面特别有意义，因为地质记录表明，由于完全冰川条件下的水分限制，它们可能会与中纬度冰川不同步地前进和后退。因此，高纬度冰川作用可能会对气候变化做出非直观的反应。该项目的主要目标是提高我们对中更新世至晚更新世期间北冰洋西部冰川作用程度的认识，并确定促成冰盖形成的主要冰源。该项目将建立一个地理信息系统数据库，收集以前在Beaufort-Chukchi地区收集的北冰洋冰川作用的地质证据，使研究人员能够测试更新世期间北冰洋西部几个地点冰川作用广泛的假设。现有的数据集将由数据档案、出版物和报告综合而成，包括：（1）通过对该区域的多次科学考察收集的安装在船体上的啁啾和多波束声纳的海洋调查数据;（2）海洋沉积物岩心;（3）关于冰川不稳定巨石和古代隆起海滩山脊的陆地记录。这项研究的结果将提高我们对高纬度冰盖在气候变化期间如何表现的理解。该项目将支持一名理学硕士学生和一名女性早期职业PI。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

The Arctic is now at the frontline of climate change as surface air temperatures warm twice as fast as the rest of the globe. Unprecedented reductions in sea ice cover are pushing the Arctic into unknown conditions. Among the most critical components of the cryosphere are high-latitude glaciers, which hold more than 99% of the world’s fresh water. These glaciers are inherently unstable and thus sensitive to climate change. We can look to how glacial systems responded to climate change in the past to better understand future glacier dynamics and to constrain future projections of glacial contributions to sea level rise. Evidence is building in support of a thick ice-sheet that spanned the Arctic Ocean, possibly multiple times, during the past 130,000 years. This project aims to bring together a diverse array of geologic evidence from the Arctic Ocean and the surrounding coastal plains, to explore the timing and extent of Arctic Ocean glaciation during the mid- to late-Pleistocene. This research will help us better understand whether an Arctic Ocean wide ice sheet existed in the past, which will in turn help us better understand future ice sheet changes.Ice sheets and ice shelves at high latitudes are of particular interest in understanding future glacier dynamics because geologic records suggest that they may advance and retreat out-of-phase with glaciers at mid-latitudes due to moisture limitations in full glacial conditions. As such, high-latitude glaciation may display non-intuitive behavior in response to climate change. The main objective of the project is to improve our understanding of the extent of glaciation in the western Arctic Ocean during the mid to late Pleistocene and to identify the main sources of ice that contributed to ice-sheet build up. The project will build a geographic information system database of previously collected geologic evidence of Arctic Ocean glaciation in the Beaufort-Chukchi region, allowing researchers to test the hypothesis that glaciation was extensive in the western Arctic Ocean at several points during the Pleistocene. Existing datasets that will be synthesized from data archives, publications and reports include (1) marine survey data from hull mounted chirp and multibeam sonars collected by numerous scientific cruises to the region, (2) marine sediment cores, and (3) terrestrial records of glacial erratic boulders and ancient raised beach ridges. Results from this research will improve our understanding of how high-latitude ice sheets can behave during periods of climatic change. This project will support one MSc student and a female early career PI.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.