Sumatran GPS Array (SuGAr)

Cross-section of Sumatra with SuGAr stations

The Sumatran GPS Array (SuGAr) spans more than a thousand kilometres of the convergent plate boundary between Indo-Australian and Asian tectonic plates. With 49 GPS stations, this network provides a wealth of information on the Sunda megathrust and the Sumatran fault.

This Array is particularly valuable scientifically for three reasons:

- Numerous GPS stations are located on islands that directly overlie the locked sections of the Sunda megathrust: they are very well situated to record interseismic, coseismic ans postseismic deformation of the upper part of the subduction zone, which is unique in the world.
- SuGAr geodetic data complement centennial and millennial paleoseismologic time series collected from coral micro-atolls in the same locations. SuGAr data can therefore be inserted into the context of several earthquake cycles.
- Several great earthquakes have occurred along the Sumatran margin since the network has been implemented, and one has even been forecast. SuGAr thus provides a great opportunity to understand pre- and post-seismic behaviour of the megathrust by monitoring tectonic deformation above it.