气候变化领域集成服务门户(CCPortal): Subglacial valleys preserved in the highlands of south and east Greenland record restricted ice extent during past warmer climates

CCPortal

DOI	10.5194/tc-18-1467-2024
	Subglacial valleys preserved in the highlands of south and east Greenland record restricted ice extent during past warmer climates
	Paxman, Guy J. G.; Jamieson, Stewart S. R.; Dolan, Aisling M.; Bentley, Michael J.
发表日期	2024
ISSN	1994-0416
EISSN	1994-0424
起始页码	18
结束页码	3
卷号	18 期号:3
英文摘要	The Greenland Ice Sheet is a key contributor to contemporary global sea level rise, but its long-term history and response to episodes of warming in Earth's geological past remain uncertain. The terrain covered by the ice sheet comprises similar to 79 % of Greenland and similar to 1.1 % of the Earth's land surface and contains geomorphological records that may provide valuable insights into past ice-sheet behaviour. Here we use ice surface morphology and radio-echo sounding data to identify ice-covered valleys within the highlands of southern and eastern Greenland and use numerical ice-sheet modelling to constrain the climatological and glaciological conditions responsible for valley incision. Our mapping reveals intricate subglacial valley networks with morphologies that are indicative of substantial glacial modification of an inherited fluvial landscape, yet many of these valleys are presently situated beneath cold-based, slow-moving (i.e. non-erosive) ice. We use the morphology of the valleys and our simple ice-sheet model experiments to infer that incision likely occurred beneath erosive mountain valley glaciers during one or more phases of Greenland's glacial history when ice was restricted to the southern and eastern highlands and when Greenland's contribution to barystatic sea level was up to + 7 m relative to today. We infer that this valley incision primarily occurred prior to the growth of a continental-scale ice sheet, most likely during the late Miocene (ca. 7-5 Ma) and/or late Pliocene (ca. 3.6-2.6 Ma). Our findings therefore provide new data-based constraints on early Greenland Ice Sheet extent and dynamics that can serve as valuable boundary conditions in models of regional and global palaeoclimate during past warm periods that are important analogues for climate change in the 21st century and beyond.
语种	英语
WOS研究方向	Physical Geography ; Geology
WOS类目	Geography, Physical ; Geosciences, Multidisciplinary
WOS记录号	WOS:001192378800001
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/303431
作者单位	Durham University; University of Leeds
推荐引用方式 GB/T 7714	Paxman, Guy J. G.,Jamieson, Stewart S. R.,Dolan, Aisling M.,et al. Subglacial valleys preserved in the highlands of south and east Greenland record restricted ice extent during past warmer climates[J],2024,18(3).
APA	Paxman, Guy J. G.,Jamieson, Stewart S. R.,Dolan, Aisling M.,&Bentley, Michael J..(2024).Subglacial valleys preserved in the highlands of south and east Greenland record restricted ice extent during past warmer climates.CRYOSPHERE,18(3).
MLA	Paxman, Guy J. G.,et al."Subglacial valleys preserved in the highlands of south and east Greenland record restricted ice extent during past warmer climates".CRYOSPHERE 18.3(2024).