[G04-P] Poster

[G04-P-05] GPS Observation to Identify Bali Back Arc Thrusting

^○Dina A. Sarsito¹, Sri Hidayati¹, Susilo Susilo³, Cecep Sulaiman², Irwan Meilano¹, Endra Gunawan¹, Estu Kriswati², Hasanuddin Z. Abidin¹, Heri Andreas¹ (1.Geodesy Research Group – Institut Teknologi Bandung, Ganesa 10, Bandung , Indonesia, 2.Geological Agency of Indonesia, Diponegoro, Bandung, Indonesia, 3.Geospatial Information Agency, Jl. Raya Jakarta-Bogor Km. 46, Cibinong, Indonesia)

Historically Bali has been influenced by several destructive earthquakes that caused widespread damages in the south of island and more than 1500 casualties especially from 1917 M 6.6 earthquake disaster. The island is the part of Sunda Shelf which is separated from Java Island by narrow strait called Bali Strait. Although Indo-Australian plate is subducting highly frontal beneath Bali, it should be considered to have low interpolate coupling indicating a low possibility of stress accumulation associated with the plate interface to the south of this island.
This research uses continuous-GPS and campaign-GPS which are distributed over Bali. By using combine analysis of GPS vector velocity, azimuth slip vector from earthquake data and simple inversion modeling, we try to infer interplate coupling on the southern subduction zone and also possible back arc thrusting in the northern part. Our preliminary results show that the combination of moderate coupling on subduction and thrusthing on the back arc contribute to the deformation pattern of the island.