INITIAL RESULTS FROM WING, THE CONTINUOUS GPS NETWORK IN THE WESTERN PACIFIC AREA

To investigate tectonic deformation in the western Pacific, a continuo us GPS tracking network has been established, and named the Western Pa cific Integrated Network of GPS (WING). Between 1995 and March 1997 we establised ten new sites. Data for the period July 1995 to October 19 96 were analyzed, together with data from International GPS Service fo r Geodynamics (IGS) global sites, to estimate daily coordinates. A fid ucial-free approach was used to obtain the most accurate baseline esti mates. To fix the estimated coordinates to the terrestrial reference f rame, il-le Tsukuba IGS site is assumed to be moving westward relative to the stable Eurasian continent at similar to 2 cm/yr according to H eki's [1996] estimate. We find that: (1) velocities of sites well with in oceanic plates an in good agreement with rigid plate motion models; (2) sites close to plate boundaries are all affected by the deformati on at those boundaries, among which back-arc rifting (spreading) is cl early visible at the Mariana and Okinawa troughs; (3) sites in eastern Asia are moving east to east-southeast relative to the stable Eurasia n continent, suggesting long distance effects of the northward collisi on of India with Asia.