DOI: 10.5194/tc-14-4475-2020
论文题名: Last glacial ice sheet dynamics offshore NE Greenland - A case study from Store Koldewey Trough
作者: Leirvik Olsen I. ; Arne Rydningen T. ; Forwick M. ; Sverre Laberg J. ; Husum K.
刊名: Cryosphere
ISSN: 19940416
出版年: 2020
卷: 14, 期: 12 起始页码: 4475
结束页码: 4494
语种: 英语
英文关键词: continental shelf
; deglaciation
; geomorphology
; ice sheet
; ice stream
; Last Glacial Maximum
; offshore structure
; sea ice
; seismic data
; trough
; Arctic
; Greenland
; Store Koldewey
英文摘要: The presence of a grounded Greenland Ice Sheet on the northeastern part of the Greenland continental shelf during the Last Glacial Maximum is supported by new swath bathymetry and high-resolution seismic data, supplemented with multi-proxy analyses of sediment gravity cores from Store Koldewey Trough. Subglacial till fills the trough, with an overlying drape of maximum 2.5 m thick glacier-proximal and glacier-distal sediment. The presence of mega-scale glacial lineations and a grounding zone wedge in the outer part of the trough, comprising subglacial till, provides evidence of the expansion of fast-flowing, grounded ice, probably originating from the area presently covered with the Storstrømmen ice stream and thereby previously flowing across Store Koldewey Island and Germania Land. Grounding zone wedges and recessional moraines provide evidence that multiple halts and/or readvances interrupted the deglaciation. The formation of the grounding zone wedges is estimated to be at least 130 years, while distances between the recessional moraines indicate that the grounding line locally retreated between 80 and 400 m yr-1 during the deglaciation, assuming that the moraines formed annually. The complex geomorphology in Store Koldewey Trough is attributed to the trough shallowing and narrowing towards the coast. At a late stage of the deglaciation, the ice stream flowed around the topography on Store Koldewey Island and Germania Land, terminating the sediment input from this sector of the Greenland Ice Sheet to Store Koldewey Trough. © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164516
Appears in Collections: 气候变化与战略
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作者单位: Department of Geosciences, UiT the Arctic University of Norway, Box 6050 Langnes, Tromsø, 9037, Norway; Norwegian Polar Institute, P.O. Box 6606 Langnes, Tromsø, 9296, Norway
Recommended Citation:
Leirvik Olsen I.,Arne Rydningen T.,Forwick M.,et al. Last glacial ice sheet dynamics offshore NE Greenland - A case study from Store Koldewey Trough[J]. Cryosphere,2020-01-01,14(12)