气候变化领域集成服务门户(CCPortal): Trough geometry was a greater influence than climate-ocean forcing in regulating retreat of the marine-based Irish-Sea Ice Stream

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DOI	10.1130/B31852.1
	Trough geometry was a greater influence than climate-ocean forcing in regulating retreat of the marine-based Irish-Sea Ice Stream
	Small D.; Smedley R.K.; Chiverrell R.C.; Scourse J.D.; Cofaigh C.; Duller G.A.T.; McCarron S.; Burke M.J.; Evans D.J.; Fabel D.; Gheorghiu D.M.; Thomas G.S.P.; Xu S.; Clark C.D.
发表日期	2018
ISSN	167606
起始页码	1981
结束页码	1999
卷号	130 期号:2021-11-12
英文摘要	Marine terminating ice streams are a major component of contemporary ice sheets and are likely to have a fundamental influence on their future evolution and concomitant contribution to sea-level rise. To accurately predict this evolution requires that modern day observations can be placed into a longer-term context and that numerical ice sheet models used for making predictions are validated against known evolution of former ice masses. New geochronological data document a stepped retreat of the paleo-Irish Sea Ice Stream from its Last Glacial Maximum limits, constraining changes in the timeaveraged retreat rates between well-defined ice marginal positions. The timing and pace of this retreat is compatible with the sediment- landform record and suggests that ice marginal retreat was primarily conditioned by trough geometry and that its pacing was independent of ocean-climate forcing. We present and integrate new luminescence and cosmogenic exposure ages in a spatial Bayesian sequence model for a north-south (173km) transect of the largest marine-terminating ice stream draining the last British- Irish Ice Sheet. From the south and east coasts of Ireland, initial rates of ice margin retreat were as high as 300-600 m a-1, but retreat slowed to 26 m a-1 as the ice stream became topographically constricted within St George's Channel, a sea channel between Ireland to the west and Great Britain to the east, and then stabilized (retreating at only 3 m a-1) at the narrowest point of the trough during the climatic warming of Greenland Interstadial 2 (GI-2: 23.3-22.9 ka). Later retreat across a normal bed-slope during the cooler conditions of Greenland Stadial 2 was unexpectedly rapid (152 m a-1). We demonstrate that trough geometry had a profound influence on ice margin retreat and suggest that the final rapid retreat was conditioned by ice sheet drawdown (dynamic thinning) during stabilization at the trough constriction, which was exacerbated by increased calving due to warmer ocean waters during GI-2. © 2018 Geological Society of America.
语种	英语
来源期刊	Bulletin of the Geological Society of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/185002
作者单位	School of Geographical and Earth Sciences, University of Glasgow, Glasgow, United Kingdom; Department of Geography, Durham University, Durham, United Kingdom; Department of Geography and Earth Sciences, Aberystwyth University, Ceredigion, United Kingdom; School of Environmental Sciences, University of Liverpool, Liverpool, United Kingdom; Centre for Geography, Environment and Society (CGES), College of Life and Environmental Sciences, University of Exeter, Penryn Campus, Penryn, Cornwall, United Kingdom; Department of Geography, Maynooth University, Maynooth, Ireland; Scottish Universities Environmental Research Centre, East Kilbride, United Kingdom; Natural Environment Research Council (NERC), Cosmogenic Isotope Analysis Facility-Scottish Univ. Environmental Research Centre (CIAF-SUERC), East Kilbride, United Kingdom; Department of Geography, University of Sheffield, Sheffield, United Kingdom
推荐引用方式 GB/T 7714	Small D.,Smedley R.K.,Chiverrell R.C.,et al. Trough geometry was a greater influence than climate-ocean forcing in regulating retreat of the marine-based Irish-Sea Ice Stream[J],2018,130(2021-11-12).
APA	Small D..,Smedley R.K..,Chiverrell R.C..,Scourse J.D..,Cofaigh C..,...&Clark C.D..(2018).Trough geometry was a greater influence than climate-ocean forcing in regulating retreat of the marine-based Irish-Sea Ice Stream.Bulletin of the Geological Society of America,130(2021-11-12).
MLA	Small D.,et al."Trough geometry was a greater influence than climate-ocean forcing in regulating retreat of the marine-based Irish-Sea Ice Stream".Bulletin of the Geological Society of America 130.2021-11-12(2018).