Geodetic measurements of postglacial adjustments in Greenland

被引:37
作者
Khan, Shfaqat Abbas [1 ]
Wahr, John [3 ]
Leuliette, Eric [4 ]
van Dam, Tonie [2 ]
Larson, Kristine M. [5 ]
Francis, Olivier [2 ]
机构
[1] Tech Univ Denmark, Danish Natl Space Ctr, Dept Geodesy, Copenhagen, Denmark
[2] Univ Luxembourg, Fac Sci Technol & Commun, L-1511 Luxembourg, Luxembourg
[3] Univ Colorado, Inst Res Environm Sci, Dept Phys & Cooperat, Boulder, CO 80309 USA
[4] Univ Colorado, Colorado Ctr Astrodynam Res, Boulder, CO 80309 USA
[5] Univ Colorado, Dept Aerosp Engn Sci, Boulder, CO 80309 USA
关键词
D O I
10.1029/2007JB004956
中图分类号
P3 [地球物理学]; P59 [地球化学];
学科分类号
0708 ; 070902 ;
摘要
We analyze data from seven continuous Global Positioning System ( GPS) receivers and one tide gauge, all located along the edge of the Greenland ice sheet, to determine vertical uplift rates. We compare our results with predictions based on the ICE-5G deglaciation model of Peltier ( 2004). Results from the GPS receiver at Kellyville (-1.2 +/- 1.1 mm/a) and from the tide gauge at Nuuk (-2.2 +/- 1.3 mm/ a), indicate that ICE-5G overestimates the subsidence rates at those locations by 2.1 and 1.1 mm/ a, respectively. Kellyville and Nuuk are located along the southwestern margin of the Greenland ice sheet, and the observed negative uplift rates are consistent with independent evidence that the ice margin along the southwestern edge readvanced during the last similar to 8 ka to its current position. The ICE-5G glaciation-deglaciation history includes a readvance between the latitudes of 62 degrees N and 72 degrees N. The GPS measurements suggest the ICE-5G readvance may be too large or mistimed. Our GPS results at Qaqortoq, located at the southern tip of Greenland, suggest a secular subsidence rate of -0.3 +/- 1.1 mm/ a, while ICE-5G predicts an uplift rate of 1.0 mm/ a. ICE-5G assumes no ice sheet readvance in south Greenland, including no readvance of the Qassimiut lobe. The difference of 1.3 +/- 1.1 mm/ a can tentatively be explained as due to a similar to 33 km readvance of the Qassimiut lobe during the last similar to 3 ka. For the other GPS sites, the observed/ predicted uplift rates are 3.6 +/- 1.1/-0.1 mm/ a at Thule, 0.0 +/- 1.1/2.0mm/a at Scoresbysund, and -0.4 +/- 1.1/-1.7mm/a at Kulusuk. For Thule, Kulusuk, and Scoresbysund the differences between the observed and predicted rates are on the order of 1.3 - 3.7 mm/ a, though with opposite signs, and indicate that ICE-5G does not exactly reproduce the correct rebound signal at those locations.
引用
收藏
页数:16
相关论文
共 45 条
[31]   ICE-AGE PALEOTOPOGRAPHY [J].
PELTIER, WR .
SCIENCE, 1994, 265 (5169) :195-201
[32]  
PODLECH S, 2004, THESIS U COPENHAGEN
[33]  
PRESS WH, 1992, NUMERICAL RECIPES FO, V77, P494
[34]  
Ray R, 1999, TM209478 NASA
[35]   Changes in the velocity structure of the Greenland ice sheet [J].
Rignot, E ;
Kanagaratnam, P .
SCIENCE, 2006, 311 (5763) :986-990
[36]   Rapid volume loss from two East Greenland outlet glaciers quantified using repeat stereo satellite imagery [J].
Stearns, Leigh A. ;
Hamilton, Gordon S. .
GEOPHYSICAL RESEARCH LETTERS, 2007, 34 (05)
[37]   Greenland glacial history and local geodynamic consequences [J].
Tarasov, L ;
Peltier, WR .
GEOPHYSICAL JOURNAL INTERNATIONAL, 2002, 150 (01) :198-229
[38]   Impact of a priori zenith hydrostatic delay errors on GPS estimates of station heights and zenith total delays [J].
Tregoning, P. ;
Herring, T. A. .
GEOPHYSICAL RESEARCH LETTERS, 2006, 33 (23)
[39]   Implications for deglaciation chronology from new AMS age determinations in central west Greenland [J].
vanTatenhove, FGM ;
vanderMeer, JJM ;
Koster, EA .
QUATERNARY RESEARCH, 1996, 45 (03) :245-253
[40]   Influence of mapping function parameters on global GPS network analyses:: Comparisons between NMF and IMF -: art. no. L01814 [J].
Vey, S ;
Dietrich, R ;
Fritsche, M ;
Rülke, A ;
Rothacher, M ;
Steigenberger, P .
GEOPHYSICAL RESEARCH LETTERS, 2006, 33 (01)