Collaborative Research: Constraining the timing and rate of southeastern Laurentide Ice Sheet thinning during the last deglaciation with cosmogenic nuclide dipsticks

合作研究：用宇宙成因核素试纸限制最后一次冰消期间劳伦太德冰盖东南部变薄的时间和速率

• 批准号: 1603175
• 负责人: Jeremy Shakun
• 金额: $ 7.01万
• 依托单位: Boston College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-01 至 2021-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1603175&HistoricalAwards=false
• 关键词: Collaborative; Research; Constraining; timing; rate

Global sea level is rising and this rise is accelerating, with implications for global economics, geopolitics, and security. The largest, but also most uncertain, control on the pace and magnitude of future sea level rise is how the Greenland and Antarctic Ice Sheets will respond to continued warming. The end of the last Ice Age provides an outstanding opportunity to probe this question since it featured the collapse of major ice sheets and abrupt mult-meter jumps in sea level that remain to be fully explained. This project will focus on reconstructing the three-dimensional collapse of the New England sector of the Laurentide Ice Sheet, the largest of the Ice Age ice masses.This research will first constrain the timing and rate of ice sheet thinning in New England by measuring surface exposure ages of glacial boulders down the sides of a dozen large mountains -- revealing when the ice sheet surface lowered below various elevations, much like rings in a bathtub. These vertical datapoints will then be combined with the well-constrained horizontal ice margin retreat history in the region to produce three-dimensional reconstructions of the ice sheet collapse through time. These reconstructions will enable an assessment of this region's contribution to deglacial sea level rise, freshwater input to the ocean and possible impacts on its circulation, and how the ice sheet responded to the abrupt climate changes of the last deglaciation -- all critical for testing computer models used to predict the future.

全球海平面正在上升，这种崛起正在加速，对全球经济学，地缘政治和安全产生了影响。对未来海平面上升的速度和幅度的最大但最不确定的控制是格陵兰和南极冰盖如何响应持续变暖。最后一个冰河时代的结束为调查这个问题提供了一个很棒的机会，因为它以大型冰盖的崩溃和突然的多米跳跃为特色，在海平面上，尚待解释。该项目将着重于重建新英格兰的劳伦德冰冰块的三维倒塌，这是最大的冰河时代冰块质量。这项研究将首先限制新英格兰的冰盖的时间和速率，通过测量冰层的冰川山脉的地面巨大山脉的底层较低的冰层较低的冰层较低的层面，在冰层下方散发出较低的山顶，这是一个较低的山顶。然后，这些垂直数据点将与该区域受约束的水平冰缘撤退历史相结合，以产生冰盖随时间崩溃的三维重建。这些重建将能够评估该地区对冰纹海平面上升的贡献，对海洋的淡水输入以及对其循环的可能影响以及冰盖对最后一次脱胶的突然气候变化的反应 - 所有这些都是用于测试用于预测未来的计算机模型的至关重要的。

项目成果

Laurentide ice sheet thinning and erosive regimes at Mount Washington, New Hampshire, inferred from multiple cosmogenic nuclides

• DOI: 10.1130/spe.s.13487109
• 发表时间: 2020-10
• 期刊: Untangling the Quaternary Period—A Legacy of Stephen C. Porter
• 作者: Alexandria J. Koester;J. Shakun;P. Bierman;P. Davis;L. Corbett;B. Goehring;A. Vickers;S. Zimmerman