气候变化领域集成服务门户(CCPortal): How dynamic are ice-stream beds?

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DOI	10.5194/tc-12-1615-2018
	How dynamic are ice-stream beds?
	Davies D.; Bingham R.G.; King E.C.; Smith A.M.; Brisbourne A.M.; Spagnolo M.; Graham A.G.C.; Hogg A.E.; Vaughan D.G.
发表日期	2018
ISSN	19940416
卷号	12 期号:5
英文摘要	Projections of sea-level rise contributions from West Antarctica's dynamically thinning ice streams contain high uncertainty because some of the key processes involved are extremely challenging to observe. An especially poorly observed parameter is sub-decadal stability of ice-stream beds, which may be important for subglacial traction, till continuity and landform development. Only two previous studies have made repeated geophysical measurements of ice-stream beds at the same locations in different years, but both studies were limited in spatial extent. Here, we present the results from repeat radar measurements of the bed of Pine Island Glacier, West Antarctica, conducted 3-6 years apart, along a cumulative ∼ 60 km of profiles. Analysis of the correlation of bed picks between repeat surveys shows that 90 % of the bed displays no significant change despite the glacier increasing in speed by up to 40 % over the last decade. We attribute the negligible detection of morphological change at the bed of Pine Island Glacier to the ubiquitous presence of a deforming till layer, wherein sediment transport is in steady state, such that sediment is transported along the basal interface without inducing morphological change to the radar-sounded basal interface. Given the precision of our measurements, the upper limit of subglacial erosion observed here is 500 mm a-1, far exceeding erosion rates reported for glacial settings from proglacial sediment yields, but substantially below subglacial erosion rates of 1.0 m a-1 previously reported from repeat geophysical surveys in West Antarctica. © 2018 Author(s).
学科领域	deformation; glacial erosion; glacier dynamics; ice stream; interface; radar; sea level change; sediment transport; stream bed; Antarctica; Pine Island Glacier; West Antarctica
语种	英语
scopus关键词	deformation; glacial erosion; glacier dynamics; ice stream; interface; radar; sea level change; sediment transport; stream bed; Antarctica; Pine Island Glacier; West Antarctica
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/119153
作者单位	School of GeoSciences, University of Edinburgh, Edinburgh, EH8 9XP, United Kingdom; NERC British Antarctic Survey, Cambridge, CB3 0ET, United Kingdom; School of Geosciences, University of Aberdeen, Aberdeen, AB24 3UF, United Kingdom; College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4RJ, United Kingdom; Centre for Polar Observation and Modelling, School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, United Kingdom
推荐引用方式 GB/T 7714	Davies D.,Bingham R.G.,King E.C.,et al. How dynamic are ice-stream beds?[J],2018,12(5).
APA	Davies D..,Bingham R.G..,King E.C..,Smith A.M..,Brisbourne A.M..,...&Vaughan D.G..(2018).How dynamic are ice-stream beds?.Cryosphere,12(5).
MLA	Davies D.,et al."How dynamic are ice-stream beds?".Cryosphere 12.5(2018).