9725693 Kellogg Key Central and South American (CASA) GPS stations will be reoccupied to analyze on-going convergent margin deformation. The three major goals of this project are: 1) To monitor the strain accumulation preceding the predicted large subduction zone thrust earthquake in the Ecuador trench. The proposed measurements together with 3-dimensional elastic half space models will map the rates of elastic strain locking and relate these to the rupture zones for the 1906, 1942, 1958, and 1979 earthquakes, testing models for the mechanics of subduction zone earthquakes. 2) Resurvey the network in northern Colombia to study the kinematics and mechanics of an active arc - continent collision zone. 3) Reoccupy sites in the South Caribbean deformed belt to study deformation in an accretionary prism to determine the location of the current Caribbean-South American plate boundary. This study is jointly funded by a large group of international agencies. ***
