This SGER proposal is requested to cover the cost of surveying coastal uplift around the Pagai and Sipora islands related to the M8.4 and 7.9 earthquakes of September 2007. Significant uplift has occurred there, rising porites heads well above the sea level (several tens of centimeters typically and locally more than 1 meter). These heads are known to grow close (within centimeters) to the sea level at the time of the low tides and their emergence thus provides a measurement of co-seismic uplift (with appropriate correction for tidal effects). This data set will provide exceptional constraints, in addition to the existing SUGAR GPS measurements, on the co-slip on the megathrust.
This research will shed important light on the characteristics of large megathrust earthquakes, with direct societal implication for Sumatra, where Padang (over 1 million inhabitants) is exposed to the risk of a M>8.5 tsunamigenic earthquake. This research will be conducted in collaboration with our Indonesian partners and will provide key data for graduate students.
