Modelling of strong motion generation areas for a great earthquake in central seismic gap region of Himalayas using the modified semi-empirical approach

Abstract

Over the past decades, strong motion generation areas (SMGAs) have received significant attention in the modelling of high-frequency records. Herein, we propose the source model for a scenario earthquake (Mw 8.5) in the central seismic gap region of Himalayas. On the rupture plane, three SMGAs have been identified. Further, SMGA parameters are evaluated using available empirical relations. The spatiotemporal distribution of aftershocks is utilised to locate these SMGAs on the rupture plane. Further, the modified semi-empirical technique (MSET) is used to simulate the strong motion records. It has been observed that the study area can expect peak ground acceleration of >100cm/s2 and its distribution is mainly affected by the location of nucleation point in the rupture plane. Furthermore, the estimated peak ground acceleration (PGA) values are comparable with the earlier studies in the region. This confirms the robustness of generated rupture model with three SMGAs and the reliability of MSET to simulate high-frequency records.