Cimandiri Fault Identification Using Earthquake Tomography Double-Difference Method

Abstract

Cimandiri Fault is one of major faults in West Java, which has a considerable potential hazard to the surrounding populated area. Therefore, it’s important to have a better understanding about the fault in order to improve disaster mitigation effort in Indonesia. This study is done to identify the Cimandiri Fault based on tomography earthquake data. The recorded data of 290 events were acquired from 15 BMKG seismograph stations located in the vicinity of study area. All events have a total of 2,895 phases consisted of 2,072 P-wave phases and 823 S-wave phases. The method used in this study to produce images beneath the surface of Western Java is double-difference travel time seismic tomography. Inversions were performed using the TomoDD algorithm to image seismic velocity models with horizontal variations from Banten Province and West Java. The final results of this study show the existence of Cimandiri Fault located in the southern part of West Java and extends with direction of North East-South West through Pelabuhan Ratu until it reaches the ocean in the south of Banten.