Bevis 9419262 The SW Pacific GPS Project has used the Global Position System (GPS) to monitor crustal motion across and within a plate boundary complex between the Australian and Pacific plates, where two active subduction systems of opposite polarity, the Tonga and New Hebrides island arcs are set by a broad interarc region which includes the North Fiji and Lau Basins. The GPS net has directly observed the kinematics of normal and collisional plate convergence, intra-arc strain and back-arc spreading. The Project has mounted three successful GPS campaigns: a small one in 1988 and two large campaigns in 1990 and 1992. The current project will the existing GPS network in this region. Prior results have demonstrated that some of the most rapid aseismic crustal motions ever observed are taking place in the Tongen trend, and that very complex water between crustal blocks are taking place in this region. It is important to follow up on the previous to confirm there actonisting observations.
