Observing Plate Motions in S.E. Asia: Geodetic Results of the GEODYSSEA Project
W.J.F. Simons, B.A.C. Ambrosius and R. Noomen
D. Angermann and P. Wilson
M. Becker and E. Reinhart
A. Walpersdorf and C. Vigny
This paper presents the final geodetic results obtained in the framework of the `GEODYnamics of South and South-East Asia' (GEODYSSEA) project. The goal of this project is to study the overall plate motions in this region. For this purpose, a network of 42 stations was observed with GPS during two field campaigns in 1994 and 1996.
The data were analyzed independently by four groups using different software packages and analysis strategies. The resulting individual network solutions were combined into 2 campaign averaged coordinate solutions. The precision of both coordinate solutions was found to be 4-7 mm for the horizontal, and 1 cm for the vertical component. Subsequently, these campaign solutions were merged into one unique solution, which was accurately mapped into the International Terrestrial Reference Frame solution of 1996 (ITRF-96) (Altamimi and Boucher, 1996).
The global accuracy of this solution with respect to ITRF-96 is of the order of 1 cm, while the resolution of the relative horizontal velocities is estimated to be at the level of 2-3 mm/yr. This solution represents the latest official geodetic result of the GEODYSSEA project and it is used as the basis for all scientific interpretations, which have been and will be published in separate papers. As an immediate result the velocity estimates of a part of the network provided the first direct measurement of a relative motion of the Sundaland block with respect to Eurasian plate.
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