Evaluation of earthquake potential using a kinematic crustal block motion model in Java, Indonesia, based on GNSS observation

Abstract

Assessing the earthquake potential in Java Island is of paramount importance due to its status as one of the world's most seismically active regions, a concern that is heightened by the island’s high population density. This study presents a comprehensive analysis of crustal deformation in Java Island, utilizing observations from Global Navigation Satellite System (GNSS) gathered over a decade, from 2008 to 2018. The GNSS data revealed a distinct non-linear trend, primarily due to the persistent post-seismic deformation following the 2006 Mw7.7 Java earthquake. To enhance the accuracy of our analysis, we employed viscoelastic relaxation modeling for data correction. Among the eleven unique crustal block motion models created, MODEL04 emerged as the optimal model for assessing earthquake potential. The seismic moment deficit rates obtained from this model provide valuable insight into the region's potential to generate future seismic events. Notably, our findings suggest that the convergence of the Australian plate with Western and Eastern Java carries the potential to produce earthquakes of Mw8.7 and Mw > 7.8, respectively. An exploration of the inland fault interfaces revealed seismic moment deficit rates suggestive of the potential for Mw7.0 earthquakes.