Crustal Displacement after the September 12, 2007 Earthquake at Phuket, Thailand

Abstract

The earthquake of September 12, 2007 from southwest of Bengkulu, Sumatra, Indonesia had the magnitude 8.4 and 7.9. It was due to thrust faulting on the boundary between the Australia and Sunda plates. This study analyzes GPS data by GIPSY-OASIS II software in two experiments. The first experiment covering a period of seven days before and after earthquake occurrence shows 4.59 mm.horizontal displacement to SE, and 4.2 mm. downward displacement vertically. The second experiment covering a period of three months, from August 1st to October 31st 2007, shows 4.96 mm. Horizontal displacement to SE, and 16 mm downward displacement vertically. Therefore, Phuket may not receive direct effect in horizontal displacement after September 12th earthquake because the horizontal displacement is 4-6 mm. which is the range of displacement typically observed in this area.