Preliminary results of local earthquake tomography around Bali, Lombok, and Sumbawa regions
- Global Geophysical Reserach Group, Faculty of Mining and Petroleum Engineering, Institute of Technology Bandung, JlGanesa 10, Bandung, 40132 (Indonesia)
- Meteorological, Climatological, and Geophysical Agency (MCGA) of Indonesian, Jakarta (Indonesia)
Bali, Sumbawa, and Lombok regions are located in active tectonic influence by Indo-Australia plate subducts beneath Sunda plate in southern part and local back-arc thrust in northern part the region. Some active volcanoes also lie from eastern part of Java, Bali, Lombok and Sumbawa regions. Previous studies have conducted subsurface seismic velocity imaging using regional and global earthquake data around the region. In this study, we used P-arrival time from local earthquake networks compiled by MCGA, Indonesia within time periods of 2009 up to 2013 to determine seismic velocity structure and simultaneously hypocenter adjustment by applying seismic tomography inversion method. For the tomographic inversion procedure, we started from 1-D initial velocity structure. We evaluated the resolution of tomography inversion results through checkerboard test and calculating derivative weigh sum. The preliminary results of tomography inversion show fairly clearly high seismic velocity subducting Indo-Australian and low velocity anomaly around volcano regions. The relocated hypocenters seem to cluster around the local fault system such as back-arc thrust fault in northern part of the region and around local fault in Sumbawa regions. Our local earthquake tomography results demonstrated consistent with previous studies and improved the resolution. For future works, we will determine S-wave velocity structure using S-wave arrival time to enhance our understanding of geological processes and for much better interpretation.
- OSTI ID:
- 22391579
- Journal Information:
- AIP Conference Proceedings, Vol. 1658, Issue 1; Conference: ISEDM 2014: 4. International Sympsoium on Earthquake and Disaster Mitigation 2014, Bandung (Indonesia), 11-12 Nov 2014; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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