CGRG Bibliography of Canadian Geomorphology
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Author : Argus, D.F.; Peltier, W.R.; Eanes, R.J.; and Heflin, M.B.
Date : 2000.
Title : Intraplate deformation due to glacial isostatic adjustment.
Publication : American Geophysical Union Fall Meeting, December 15-19, 2000. San Francisco, California.
Issue :
Page(s) :
Abstract
Observations from very long baseline interferometry, satellite laser ranging, and the global positioning system are combined to study the isostatic response of the solid earth to unloading of the late Pleistocene ice sheets. The geodetic observations are for the most part consistent with the postglacial rebound models of Peltier [1994, 1996], which are based largely on radiocarbon dating of relative sea level markers several thousand years old. Places that were beneath the centers of the former Fennoscandia and Laurentide ice sheets are observed to be rising, reflecting rebound in response to unloading of the ice sheets. Places that were in the former forebulge areas are observed to be subsiding slowly or not moving vertically at all. Geodesy is further constraining the postglacial rebound models in two ways. First, observations of the vertical motions of sites not along the coastlines are constraining the maximum former thickness of the ice sheets at places not sampled by the Holocene relative sea level histories. For example, Yellowknife, Northwestern Territories, Canada is estimated to be rising at 8 .3 mm/yr (95\% conf. limits), at a rate significantly faster than the 3 mm/yr predicted by the two rebound models. This rapid rise indicates that the western part of the Laurentide ice sheet was thicker during the last glacial maximum that previously thought. Second, observations of lateral site motions are beginning to limit the combination of mantle viscosity and lithospheric thickness. Places that were along the margins of the former ice sheets appear to be moving away from the former ice sheets very slowly, at speeds of 1 to 2 mm/yr. The consistency between the geodetic data and the rebound models indicates that, aside from local phenomena, glacial isostatic adjustment is the biggest cause of current intraplate deformation.
Bibliography of Canadian Geomorphology