HR: 15:25h
AN: G13C-08    [Abstracts]
TI: ITRF2005 Plate Motion Model: A Sensitivity Analysis
AU: * Altamimi, Z
EM: altamimi@ensg.ign.fr
AF: Zuheir Altamimi, Institut Geographique National ENSG/LAREG, Champs-sur-Marne, 77455, France
AU: Legrand, J
EM: Juliette.Legrand@oma.be
AF: Juliette Legrand, Royal Observatory of Belgium Av. Circulaire 3, Brussels, B-1180, Belgium
AB: The use of time series of station positions as input data for the construction of the ITRF2005 allows to control and eliminate station non-linear motion and all kind of discontinuities that would contaminate the long-term velocity estimates. We derived an absolute ITRF2005 Plate Motion Model using a velocity field of 152 sites located on rigid part of 15 tectonic plates. Given the 5 years more data and the greater number of sites involved, compared to what was used in case of ITRF2000 plate motion model, the angular velocities of the major plates appear to be better determined with the ITRF2005 data. However, this paper focuses on a comparative sensitivity analysis to a certain number of variants that impact the angular velocity estimates. The following variants are tested and the results of their comparisons are reported: number and distribution of sites per plate; solving for all plates motions simultaneously or separately; using full variance covariance matrix or diagonal terms only; assessing the impact of the Z-translation of 1.8 mm/yr between ITRF2000 and ITRF2005. Based on these tests we finally attempt to quantify the accuracy of the present day plate motion determination as derived from space geodesy measurements.
DE: 1209 Tectonic deformation (6924)
DE: 1229 Reference systems
DE: 1240 Satellite geodesy: results (6929, 7215, 7230, 7240)
DE: 8155 Plate motions: general (3040)
DE: 8158 Plate motions: present and recent (3040)
SC: Geodesy [G]
MN: 2007 Fall Meeting