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DOI	10.1016/j.epsl.2021.116972
	Effect of ice sheet thickness on formation of the Hiawatha impact crater
	Silber E.A.; Johnson B.C.; Bjonnes E.; MacGregor J.A.; Larsen N.K.; Wiggins S.E.
发表日期	2021
ISSN	0012821X
卷号	566
英文摘要	The discovery of a large putative impact crater buried beneath Hiawatha Glacier along the margin of the northwestern Greenland Ice Sheet has reinvigorated interest into the nature of large impacts into thick ice masses. This circular structure is relatively shallow and exhibits a small central uplift, whereas a peak-ring morphology is expected. This discrepancy may be due to long-term and ongoing subglacial erosion but may also be explained by a relatively recent impact through the Greenland Ice Sheet, which is expected to alter the final crater morphology. Here we model crater formation using hydrocode simulations, varying pre-impact ice thickness and impactor composition over crystalline target rock. We find that an ice-sheet thickness of 1.5 or 2 km results in a crater morphology that is consistent with the present morphology of this structure. Further, an ice sheet that thick substantially inhibits ejection of rocky material, which might explain the absence of rocky ejecta in most existing Greenland deep ice cores if the impact occurred during the late Pleistocene. From the present morphology of the putative Hiawatha impact crater alone, we cannot distinguish between an older crater formed by a pre-Pleistocene impact into ice-free bedrock or a younger, Pleistocene impact into locally thick ice, but based on our modeling we conclude that latter scenario is possible. © 2021 Elsevier B.V.
关键词	craters ice sheets impacts
英文关键词	Ice; Morphology; Circular structures; Crater; Crater morphology; Greenland Ice Sheet; Ice mass; Ice sheet; Impact; Impact craters; Pleistocene; Sheet thickness; Glaciers; crater; crystalline rock; glacier; ice sheet; ice thickness; Arctic; Greenland; Greenland Ice Sheet
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/203297
作者单位	Department of Earth Sciences, Western University, London, ON N6A 5B7, Canada; The Institute for Earth and Space Exploration, Western University, London, ON N6A 3K7, Canada; Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, IN, United States; Department of Physics and Astronomy, Purdue University, West Lafayette, IN, United States; Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, RI, United States; Cryospheric Sciences Lab, NASA Goddard Space Flight Center, Greenbelt, MD, United States; GLOBE Institute, University of Copenhagen, Copenhagen, Denmark
推荐引用方式 GB/T 7714	Silber E.A.,Johnson B.C.,Bjonnes E.,et al. Effect of ice sheet thickness on formation of the Hiawatha impact crater[J],2021,566.
APA	Silber E.A.,Johnson B.C.,Bjonnes E.,MacGregor J.A.,Larsen N.K.,&Wiggins S.E..(2021).Effect of ice sheet thickness on formation of the Hiawatha impact crater.Earth and Planetary Science Letters,566.
MLA	Silber E.A.,et al."Effect of ice sheet thickness on formation of the Hiawatha impact crater".Earth and Planetary Science Letters 566(2021).