IDS Workshop 2006Abstract

Plate motion and glacial isostatic adjustment from DORIS

Dr Donald ARGUS⁽¹⁾, Dr Pascal WILLIS⁽²⁾

⁽¹⁾ Jet Propulsion Laboratory, California Institute of Technology, Pasadena, USA
⁽²⁾ Institut Geographique National (and Jet Propulsion Laboratory, California Institute of Technology), Saint-Mande, France

Session theme: Stations coordinates

Abstract

Positions from 1993 to 2005 estimated from DORIS are used to estimate the velocities of 39 sites on the interiors of 10 plates. Velocities are estimated enforcing measured ties between beacons at a mark and between nearby marks. Uncertainties in velocity are assessed using (1) data decimation, (2) comparison with the three other main space geodetic techniques, and (3) consistency with plate rigidity and with models of postglacial rebound. An error budget is formed in which the standard error in a horizontal site velocity component is taken to be 18 mm divided by the time period of observation at a site; the standard error in a vertical site velocity component is taken to be 27 mm divided by the time period of observation. The angular velocities of the Eurasian, North American, South American, Nubian, Somalian, Antarctic, Australia, Pacific, and Nazcan plates are estimated. The uncertainties in the angular velocities from DORIS are several times bigger than uncertainties in plate angular velocities estimated combining all 4 techniques. The two sets of angular velocities are consistent for all plate pairs. The DORIS observations suggest that Yellowknife (Canada) and Ny Alesund (Svalbard) are rising in glacial isostatic adjustment to, respectively, late Pleistocene unloading of the Laurentide ice sheet and current unloading of glaciers in Svalbard

 
Corresponding author:

Dr Donald ARGUS
Jet Propulsion Laboratory, California Institute of Technology
4800 Oak Grove Dr.
91109 Pasadena, CA
USA
Phone: 818 354 3380
Fax: 818 393 4965
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