DOI: 10.5194/tc-14-3487-2020
论文题名: Surface velocity of the Northeast Greenland Ice Stream (NEGIS): Assessment of interior velocities derived from satellite data by GPS
作者: Hvidberg C.S. ; Grinsted A. ; Dahl-Jensen D. ; Khan S.A. ; Kusk A. ; Andersen J.K. ; Neckel N. ; Solgaard A. ; Karlsson N.B. ; Kjar H.A. ; Vallelonga P.
刊名: Cryosphere
ISSN: 19940416
出版年: 2020
卷: 14, 期: 10 起始页码: 3487
结束页码: 3502
语种: 英语
英文关键词: bedrock
; digital elevation model
; glacial hydrology
; GPS
; ice core
; satellite data
; shear strength
; smoothing
; topography
; velocity profile
; Arctic
; East Greenland
; Greenland
; Greenland Ice Sheet
英文摘要: The Northeast Greenland Ice Stream (NEGIS) extends around 600 km upstream from the coast to its onset near the ice divide in interior Greenland. Several maps of surface velocity and topography of interior Greenland exist, but their accuracy is not well constrained by in situ observations. Here we present the results from a GPS mapping of surface velocity in an area located approximately 150 km from the ice divide near the East Greenland Ice-core Project (EastGRIP) deep-drilling site. A GPS strain net consisting of 63 poles was established and observed over the years 2015-2019. The strain net covers an area of 35 km by 40 km, including both shear margins. The ice flows with a uniform surface speed of approximately 55ma1 within a central flow band with longitudinal and transverse strain rates on the order of 104 a1 and increasing by an order of magnitude in the shear margins. We compare the GPS results to the Arctic Digital Elevation Model and a list of satellite-derived surface velocity products in order to evaluate these products. For each velocity product, we determine the bias in and precision of the velocity compared to the GPS observations, as well as the smoothing of the velocity products needed to obtain optimal precision. The best products have a bias and a precision of 0:5ma1. We combine the GPS results with satellite-derived products and show that organized patterns in flow and topography emerge in NEGIS when the surface velocity exceeds approximately 55ma1 and are related to bedrock topography. © 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/164488
Appears in Collections: 气候变化与战略
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作者单位: Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark; Dtu Space, Technical University of Denmark, Kongens Lyngby, Denmark; Alfred-Wegener-Institut, Helmholtz-Zentrum för Polar-und Meeresforschung, Bremerhaven, Germany; Geological Survey of Denmark and Greenland, Copenhagen, Denmark
Recommended Citation:
Hvidberg C.S.,Grinsted A.,Dahl-Jensen D.,et al. Surface velocity of the Northeast Greenland Ice Stream (NEGIS): Assessment of interior velocities derived from satellite data by GPS[J]. Cryosphere,2020-01-01,14(10)