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过程中东南劳伦特冰盖减薄的时间和速率

基本信息

批准号：
1602280
负责人：
Paul Bierman
金额：
$ 9.42万
依托单位：
University of Vermont & State Agricultural 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 2022-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1602280&HistoricalAwards=false
关键词：
COLLABORATIVE RESEARCH CONSTRAINING TIMING RATE

项目摘要

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，而且上升速度还在加速，对全球经济、地缘政治和安全产生影响。对未来海平面上升速度和幅度的最大但也是最不确定的控制是格陵兰岛和南极冰盖将如何应对持续变暖。上一个冰河时代的结束为探讨这个问题提供了一个绝佳的机会，因为它的特点是主要冰盖的崩塌和海平面突然的多米跃升，这些仍有待充分解释。该项目将重点重建劳伦泰冰盖新英格兰部分的三维塌陷，劳伦泰冰盖是冰河时代最大的冰块。这项研究将首先通过测量十几座大山两侧冰川巨石的表面暴露年龄来限制新英格兰冰盖变薄的时间和速度，揭示冰盖表面何时降低到不同海拔以下，就像冰盖中的环一样。浴缸。然后，这些垂直数据点将与该地区受良好约束的水平冰缘退缩历史相结合，以产生冰盖随时间崩塌的三维重建。这些重建将能够评估该地区对冰消期海平面上升的贡献、流入海洋的淡水及其对其循环的可能影响，以及冰盖如何响应上次冰消期的突然气候变化——所有这些对于测试计算机都至关重要用于预测未来的模型。