Basal melt at NorthGRIP modeled from borehole, ice-core and radio-echo sounder observations

被引:86
作者
DahlJensen, D
Gundestrup, N
Gogineni, SP
Miller, H
机构
[1] Univ Copenhagen, Niels Bohr Inst Astron Phys & Geophys, DK-2100 Copenhagen, Denmark
[2] Univ Kansas, Radar Syst & Remote Sensing Lab, Lawrence, KS 66045 USA
[3] Alfred Wegener Inst Polar & Marine Res, D-27568 Bremerhaven, Germany
来源
ANNALS OF GLACIOLOGY, VOL 37 | 2003年 / 37卷
关键词
D O I
10.3189/172756403781815492
中图分类号
P [天文学、地球科学];
学科分类号
07 ;
摘要
From temperature measurements down through the 3001 m deep bore-hole at the North Greenland Icecore Project (NorthGRIP) drill site, it is now clear that the ice at the base, 3080 m below the surface, is at the pressure-melting point. This is supported by the measurements on the ice core where the annual-layer thicknesses show there is bottom melting at the site and upstream from the borehole. Surface velocity measurements, internal radio-echo layers, borehole and ice-core data are used to constrain a time-dependent flow model simulating flow along the north-northwest-trending ice-ridge flow-line, leading to the NorthGRIP site. Also time-dependent melt rates along the flowline are calculated with a heat-flow model. The results show the geothermal heat flow varies from 50 to 200 mW m(-2) along the 100 km section of the modeled flowline. The melt rate at the NorthGRIP site is 0.75 cm a(-1), but the deep ice in the NorthGRIP core originated 50 km upstream and has experienced melt rates as high as 1.1 cm a(-1).
引用
收藏
页码:207 / 212
页数:6
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