| 项目编号: | 1552230
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| 项目名称: | Cosmogenic surface exposure dating of Cordilleran-Laurentide ice-sheet separation during the last deglaciation: implications for abrupt sea-level rise |
| 作者: | Anders Carlson
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| 承担单位: | Oregon State University
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| 批准年: | 2016
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| 开始日期: | 2016-02-15
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| 结束日期: | 2019-01-31
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| 资助金额: | 249931
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| 资助来源: | US-NSF
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| 项目类别: | Standard Grant
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| 国家: | US
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| 语种: | 英语
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| 特色学科分类: | Geosciences - Earth Sciences
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| 英文关键词: | ice sheet
; mwp-1a
; cis-lis separation
; mwp
; cordilleran-laurentide
; cordilleran
; ice-free corridor
; last deglaciation
; ice saddle
; global-mean sea-level rise
; cis-lis
; sea-level
; abrupt sea-level rise
; rapid sea-level rise
; boulder cosmogenic surface exposure age
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| 英文摘要: | The rise in sea level during the last deglaciation (21,000-6,000 years ago) was punctuated by intervals of abrupt sea-level rise, called meltwater pulses (MWP), which indicate the development of instability in one or more of Earth's ice sheets. The largest MWP, MWP-1A, occurred 14,600-14,300 years ago with ~14 m of global-mean sea-level rise. It was recently hypothesized that the collapse of an ice saddle between the Cordilleran (CIS) and Laurentide (LIS) ice sheets could have caused MWP-1A when the two ice sheets separated. Results from this research will provide important data on whether the ice sheet failure caused rapid jumps in sea level. Determining if the ice sheet separation caused a MWP will provide insight into the evolution of North Atlantic climate and its relationship to meltwater discharge to the Arctic Ocean where much of the ice sheet separation meltwater would be routed. These findings will also have implications for development of instability in the Greenland ice sheet as it has an ice saddle similar to the one previously seen in the Cordilleran-Laurentide. Finally, these results will date when an ice-free corridor formed between the Cordilleran and Laurentide ice sheets, which has important ramifications for human migration routes to the Americas.
This project will date the end of CIS-LIS separation with 50 boulder cosmogenic surface exposure ages at six locations along the suture zone of the ice sheets between 50°N and 60°N. These ages will determine when CIS-LIS separation was complete, and if it was concurrent with MWP-1A or another interval of rapid sea-level rise. They will also document if CIS-LIS separation occur over centuries, which could cause a MWP, or over millennia which would be inconsistent with separation causing a MWP. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/92867
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| Appears in Collections: | 全球变化的国际研究计划
科学计划与规划
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| Recommended Citation: | |
Anders Carlson. Cosmogenic surface exposure dating of Cordilleran-Laurentide ice-sheet separation during the last deglaciation: implications for abrupt sea-level rise. 2016-01-01.
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