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DOI	10.5194/tc-12-2249-2018
	Simulated retreat of Jakobshavn Isbræ since the Little Ice Age controlled by geometry
	Steiger N.; Nisancioglu K.H.; Åkesson H.; De Fleurian B.; Nick F.M.
发表日期	2018
ISSN	19940416
卷号	12 期号:7
英文摘要	Rapid retreat of Greenland's marine-terminating glaciers coincides with regional warming trends, which have broadly been used to explain these rapid changes. However, outlet glaciers within similar climate regimes experience widely contrasting retreat patterns, suggesting that the local fjord geometry could be an important additional factor. To assess the relative role of climate and fjord geometry, we use the retreat history of Jakobshavn Isbræ, West Greenland, since the Little Ice Age (LIA) maximum in 1850 as a baseline for the parameterization of a depth- and width-integrated ice flow model. The impact of fjord geometry is isolated by using a linearly increasing climate forcing since the LIA and testing a range of simplified geometries. We find that the total length of retreat is determined by external factors - such as hydrofracturing, submarine melt and buttressing by sea ice - whereas the retreat pattern is governed by the fjord geometry. Narrow and shallow areas provide pinning points and cause delayed but rapid retreat without additional climate warming, after decades of grounding line stability. We suggest that these geometric pinning points may be used to locate potential sites for moraine formation and to predict the long-term response of the glacier. As a consequence, to assess the impact of climate on the retreat history of a glacier, each system has to be analyzed with knowledge of its historic retreat and the local fjord geometry. © 2018 Author(s).
学科领域	climate forcing; climate variation; fjord; geometry; glacier retreat; grounding line; ice flow; Little Ice Age; moraine; parameterization; sea ice; Arctic; Greenland; Jakobshavn Glacier
语种	英语
scopus关键词	climate forcing; climate variation; fjord; geometry; glacier retreat; grounding line; ice flow; Little Ice Age; moraine; parameterization; sea ice; Arctic; Greenland; Jakobshavn Glacier
来源期刊	Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/119105
作者单位	Geophysical Institute, University of Bergen, Bjerknes Centre for Climate Research, Bergen, Norway; Department of Earth Science, University of Bergen, Bjerknes Centre for Climate Research, Bergen, Norway; Centre for Earth Evolution and Dynamics, University of Oslo, Oslo, Norway; Department of Arctic Geology, University Centre in Svalbard, Longyearbyen, Norway; Department of Geological Sciences, Stockholm University, Bolin Centre for Climate Research, Stockholm, Sweden
推荐引用方式 GB/T 7714	Steiger N.,Nisancioglu K.H.,Åkesson H.,et al. Simulated retreat of Jakobshavn Isbræ since the Little Ice Age controlled by geometry[J],2018,12(7).
APA	Steiger N.,Nisancioglu K.H.,Åkesson H.,De Fleurian B.,&Nick F.M..(2018).Simulated retreat of Jakobshavn Isbræ since the Little Ice Age controlled by geometry.Cryosphere,12(7).
MLA	Steiger N.,et al."Simulated retreat of Jakobshavn Isbræ since the Little Ice Age controlled by geometry".Cryosphere 12.7(2018).