ABSTRACT
During the 2015 Mw7.8 Gorkha earthquake, which is the largest to have struck Kathmandu in the last 80 years, the ground motion inside the basin exhibited a notable amplification at low frequencies (<0.9 Hz). Different factors, including source, path as well as site effects, were responsible for the unusual recorded ground motion characteristics. To shed light on the site effects contribution, we study the seismic response of the Kathmandu basin by means of 3D physics-based numerical simulations of some of the aftershocks of the Gorkha earthquake, using the open-source high-performance spectral element code SPEED. To this aim, we developed a large 3D numerical model for the central part of Nepal, including the most recent data for the Kathmandu basin geometry and soil stratigraphy. With the ever-increasing computational power, 3D numerical simulations are becoming increasingly appealing to study the seismic response of complex tectonic and geological systems. The 3D model presented here could support future studies on the seismic response of the Kathmandu basin.
