Crustal structure in the southern part of West Java based on analysis of teleseismic receiver function

Abstract

We analyzed teleseismic receiver functions from five broadband stations to determine the crustal thickness and Vp/vs ratios in the southern part of west Java. We observed that the study area is characterized by crustal thickness around 31-37 km with Vp/Vs varying between 1.66 and 1.87. We suggest that lower values of Vp/Vs obtained in some stations indicate more felsic crustal composition. The mid-crust low velocity zone is observed beneath a seismic station located near the volcanic zones with high values of Vp/Vs ratio suggesting the presence of partial melt due to geothermal activities in the upper mantle. Furthermore, a seismic station located near the active fault zone also has high Vp/Vs ratio, which may indicate the presence of fluid filled fracture zone. However, this station exhibits complicated receiver functions, thus it needs further research involving a larger dataset with good backazimuth coverage of the teleseismic data to resolve this issue.