气候变化领域集成服务门户(CCPortal): Glacial sedimentation, fluxes and erosion rates associated with ice retreat in Petermann Fjord and Nares Strait, north-west Greenland

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DOI	10.5194/tc-14-261-2020
	Glacial sedimentation, fluxes and erosion rates associated with ice retreat in Petermann Fjord and Nares Strait, north-west Greenland
	Hogan K.A.; Jakobsson M.; Mayer L.; Reilly B.T.; Jennings A.E.; Stoner J.S.; Nielsen T.; Andresen K.J.; Nørmark E.; Heirman K.A.; Kamla E.; Jerram K.; Stranne C.; Mix A.
发表日期	2020
ISSN	19940416
起始页码	261
结束页码	286
卷号	14 期号:1
英文摘要	Petermann Fjord is a deep ( > 1000 m) fjord that incises the coastline of north-west Greenland and was carved by an expanded Petermann Glacier, one of the six largest outlet glaciers draining the modern Greenland Ice Sheet (GrIS). Between 5 and 70m of unconsolidated glacigenic material infills in the fjord and adjacent Nares Strait, deposited as the Petermann and Nares Strait ice streams retreated through the area after the Last Glacial Maximum. We have investigated the deglacial deposits using seismic stratigraphic techniques and have correlated our results with high-resolution bathymetric data and core lithofacies. We identify six seismoacoustic facies in more than 3500 line kilometres of subbottom and seismic-reflection profiles throughout the fjord, Hall Basin and Kennedy Channel. Seismo-acoustic facies relate to bedrock or till surfaces (Facies I), subglacial deposition (Facies II), deposition from meltwater plumes and icebergs in quiescent glacimarine conditions (Facies III, IV), deposition at grounded ice margins during stillstands in retreat (grounding-zone wedges; Facies V) and the redeposition of material downslope (Facies IV). These sediment units represent the total volume of glacial sediment delivered to the mapped marine environment during retreat. We calculate a glacial sediment flux for the former Petermann ice stream as 1080-1420m3 a-1 per metre of ice stream width and an average deglacial erosion rate for the basin of 0.29-0.34mma-1. Our deglacial erosion rates are consistent with results from Antarctic Peninsula fjord systems but are several times lower than values for other modern GrIS catchments. This difference is attributed to fact that large volumes of surface water do not access the bed in the Petermann system, and we conclude that glacial erosion is limited to areas overridden by streaming ice in this large outlet glacier setting. Erosion rates are also presented for two phases of ice retreat and confirm that there is significant variation in rates over a glacial- deglacial transition. Our new glacial sediment fluxes and erosion rates show that the Petermann ice stream was approximately as efficient as the palaeo-Jakobshavn Isbræ at eroding, transporting and delivering sediment to its margin during early deglaciation. © Author(s) 2020.
英文关键词	bathymetry; bedrock; coast; erosion rate; ice stream; Last Glacial Maximum; lithofacies; meltwater; redeposition; Arctic; Greenland; Greenland Ice Sheet; Petermann Glacier
语种	英语
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/202103
作者单位	British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 0ET, United Kingdom; Center for Coastal and Ocean Mapping, University of New Hampshire, Durham, NH 03824, United States; Department of Geological Sciences, Stockholm University, Stockholm, 106 91, Sweden; Bolin Centre for Climate Research, Stockholm University, Stockholm, 106 91, Sweden; College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331, United States; Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO 80309-0450, United States; Geological Survey of Denmark and Greenland, Øster Voldgade 10, Copenhagen K, 1350, Denmark; Department of Geoscience, Aarhus University, Hoegh-Guldbergs Gade 2, Aarhus C, 8000, Denmark; TNO, Geological Survey of Netherlands, Princetonlaan 6, Utrecht, 3584 CB, Netherlands; Rambøll Management Consulting, Hannemanns Allé 53, Copenhagen S, 2300, Denmark
推荐引用方式 GB/T 7714	Hogan K.A.,Jakobsson M.,Mayer L.,et al. Glacial sedimentation, fluxes and erosion rates associated with ice retreat in Petermann Fjord and Nares Strait, north-west Greenland[J],2020,14(1).
APA	Hogan K.A..,Jakobsson M..,Mayer L..,Reilly B.T..,Jennings A.E..,...&Mix A..(2020).Glacial sedimentation, fluxes and erosion rates associated with ice retreat in Petermann Fjord and Nares Strait, north-west Greenland.Cryosphere,14(1).
MLA	Hogan K.A.,et al."Glacial sedimentation, fluxes and erosion rates associated with ice retreat in Petermann Fjord and Nares Strait, north-west Greenland".Cryosphere 14.1(2020).