This project represents an opportunity for US scientists to continue cooperation with scientists from Colombia, Costa Rica, Ecuador, Germany, Panama, Switzerland, and Venezuela in the epoch measurements in the Central and South America (CASA) network. This is a field program to obtain precise repeat GPS baseline measurements between 45 sites in the North Andean convergent margin. The observations will include: 1) short baselines across the Colombia trench (400 km) and the Middle America trench (540 km) where we can directly measure rapid subduction rates. 2) A survey network across the South Caribbean deformed belt will test predictions of aseismic subduction of Caribbean oceanic crust beneath the North Andes. 3) Baseline observations across the active Santa Marta, Romeral, and East Andean fault systems test predicted shear strain models for the North Andean microplate.
