Geodynamics of S.E. Asia: First results of the Sulawesi 1998 GPS campaign

In November 1998, concurrently with the third GPS campaign of the international GEODY5SEA (GEODYnamics of South and South East Asia) project, a dense geodetic network in Sulawesi, Indonesia was re-measured with GPS. The network is situated in. a tectonic complex region near the triple junction of the Eurasian, the Philippine and the Indo-Australian tectonic plates. The GPS campaign included second and third repeat measurements for densification sites of the GEODYSSEA network in this region, and also a re-measurement of a Pa1u¬Koro fault transect in Sulawesi. The acquired data, together with data from IGS stations in the same region, have been processed at DEOS, using the JPL GIPSY-II software, while the DEOS 3D-Motion software was used for the network deformation analysis. The station coordinates were analyzed together with those of the previous Sulawesi campaigns and the GEODYSSEA campaigns of 1994 and 1996. Our kinematic model for the present motions was further validated and improved, and contains both steady state velocity and non-linear displacements. The tectonic block and fault motions are compared with previous results and are geophysically interpreted, and provide detailed new information for this region.