The Response of the Greenland Ice Sheet to Holocene Climate Change: Testing Ice Sheet Models and Forcing Mechanisms of Ice-Margin Change

鉴于最近格陵兰岛气候迅速变暖，冰盖对气候变化的反应越来越令人担忧。科学家们的共识是，海洋条件(如温度和洋流)在控制冰盖退缩速度方面发挥着关键作用。该项目将在一条包括格陵兰冰盖海洋和陆地终端部分的广泛地理走廊上重建格陵兰西部冰盖的变化。从这些地点进行的测量将有助于展示被认为控制冰缘对气候变化反应的不同机制。该项目将结合过去冰缘变化的地质重建以及遥感和摄影测量方法，生成整个全新世、直到20世纪并包括20世纪的冰缘变化记录。地质重建利用了未开发的冰川湖泊中包含的以前冰缘位置的档案。此外，宇宙成因的10Be测年将产生全新世早期冰缘衰退的记录，无论是海洋冰川终端还是陆地冰川终端都发生了这种情况。20世纪冰缘变化的记录将利用最近产生的空间数据集，如基于航空照片的地形图、卫星图像、激光和雷达数据，这些数据提供了冰盖及其表面的高分辨率图像。尽管格陵兰冰盖有可能对海平面上升做出巨大贡献，以应对持续和预计的气候变化，从而在美国和全球范围内造成重大的社会经济影响，但冰盖的未来行为在很大程度上仍然不确定。这种不确定性源于我们对冰盖对气候变化反应的模式和时间尺度的不完全了解。反过来，这又源于我们对冰盖变化的相对简短的看法，这种看法仅限于几十年。该项目将根据过去10,000年来不同类型的冰盖部门对气候变化的反应，提高我们对控制冰缘变化的因素的理解。通过将这些结果与海洋记录以及其他冰缘和气候重建相结合，该项目的发现将有助于预测未来的冰盖和海平面变化。

Ice sheet response to climate change is a growing concern in light of recent rapid climate warming over Greenland. A consensus among scientists is that oceanographic conditions (e.g., temperature and currents) play a critical role in controlling rates of ice sheet retreat. This project will generate reconstructions of western Greenland Ice Sheet change across a wide geographic corridor that encompasses both marine- and land-terminating sectors of the Greenland Ice Sheet. Measurements from these locations will help demonstrate the different mechanisms thought to control ice margin response to climate change. The project will combine geological reconstructions of past ice margin change and remote sensing and photogrammetry methods to generate records of ice margin change throughout the Holocene, up to and including the 20th century. The geological reconstructions take advantage of untapped archives of former ice margin positions contained within proglacial lakes. In addition, cosmogenic 10Be dating will generate records of early Holocene ice margin recession that took place for both marine- and land-based glacier termini. Records of 20th century ice margin change will take advantage of recently produced spatial datasets such as aerial-photograph-based topographic maps, satellite images, laser and radar data that provide high-resolution images of the ice sheet bed and its surfaceDespite the potential of the Greenland Ice Sheet to contribute dramatically to sea level rise in response to ongoing and projected climate change, resulting in significant socio-economic impacts in the US and around the globe, the future behavior of the ice sheet remains largely uncertain. This uncertainty stems from our incomplete knowledge of the pattern and timescales of the ice sheet's response to climate change. This, in turn, stems from a relatively brief view that we have of ice sheet change, which is limited to several decades. This project will improve our understanding of what controls ice margin change based on how different types of ice sheet sectors have responded to climate changes over the last 10,000 years. By combining these results with marine records and other ice margin and climate reconstructions, the findings of this project will be useful in forecasting future ice sheet and sea level change.