This research is to conduct geological studies of the two principal fault zones of Sumatra, Indonesia, in concert with ongoing geodetic studies of the region. Dating of uplifted coral reefs to document the timing, geographical extent and uplift of two great historical subduction-zone earthquakes and their prehistoric predecessors should provide a precise and complete record of great subduction zone earthquakes in the region. The right-lateral Sumatran fault will be dated by offset channels of datable pyroclastic deposits from the Sumatran volcanic arc. The research will address fundamental issues in earthquake mechanics and neotectonics and provide a firmer basis for seismic hazard evaluation in Sumatra. This research is a component of the National Earthquake Hazard Reduction Program.
