I conduct inversion for the megathrust coupling model of the Makran subduction zone from interseismic GPS velocity data. I utilize the model resolution matrix to explore possible plate-coupling scenarios that are consistent with the limited spatial resolution afforded by GPS observations. Based on these coupling scenarios, I predict possible future earthquake ruptures, and forward model the corresponding tsunami responses within the western Indian Ocean basin. My results show potential segmentation of the Makran megathrust with varying coupling from west to east, and the largest future earthquake scenario is able to produce tsunami of maximum wave height up to 5 m at major coastal cities in the region.

In many numerical modeling studies of the Earth system. Crustal deformation in response to earthquake rupture is assumed to be an elastic process, where earthquake-induced strain is recoverable after several earthquake cycles. Inelastic deformation, or permanent damages caused by the earthquake are ignored in under the elastic assumption, leading to inaccurate estimation of earthquake hazard potential, earthquake mechanisms, or fault zone properties. This dissertation focuses on revealing the inelastic behaviors of the Earth during or after large earthquakes, through the application of satellite-based geodetic observations and numerical modeling techniques.

I monitor the 6.5-year post-seismic deformation following the 2013 Baluchistan earthquake using Sentinel-1 InSAR time-series, and apply finite element modeling to simulate the time-dependent deformation of the Makran accretionary prism. My results show that power-law viscoelastic relaxation of an earthquake stress-induced, low-viscosity zone within the lower accretionary prism contributes to most of the post-seismic deformation. I argue that the low-temperature viscous behavior of the lower Makran wedge results from the high fluid saturation within the accretionary prism.

I present the surface strain field of the 2013 Mw7.7 Baluchistan earthquake in southern Pakistan. I invert co-seismic displacement maps generated from pixel-tracking of SPOT-5 optical images for co-seismic surface horizontal strain tensors. I show that co-seismic inelastic surface deformation is localized to a narrow zone about 100-200 m wide on the hanging wall side of the fault. I find that the width of the inelastic deformation zone correlates to fault maturity, and that the permanent surface strains reflect deformation of the fault damage zone.