Feasibility study on the potential of satellite altimetry for detecting seismic geoid changes due to the 2004 Sumatra-Andaman earthquake

Sea surface height data obtained by satellite altimetry from Jason-1 and TOPEX/Poseidon were analyzed to explore the possibility of a seismic geoid change due to the 2004 Sumatra-Andaman earthquake. This analysis identified a weakly positive geoid change in a region between the trench and outer arc. A subsequent investigation of the characteristics of this coseismic geoid change based on the dislocation theory revealed that a positive peak should indicate the upper edge of the high-slipped area or asperity and that a negative peak is responsible for the lower edge of the earthquake fault. An attempt at modeling the difference in the sea level anomaly failed to explain the observation since a large scatter in the original dataset obstructed its confirmation.