This article simulates the ground motion during the devastating 18th September 2011 Sikkim earthquake by analytical approaches. Surface level peak ground acceleration (PGA) values at several stations in the epicentral region have been estimated by the finite fault seismological model. A PGA contour map in the epicentral region is provided. It is found that very near to the epicentre, PGA would have reached more than 0.3g. The SPECFEM3D_GLOBE package which models the complete three-dimensional wave velocity structure and topography is used to simulate the displacement time histories on a global scale. A contour map of peak ground displacement (PGD) and permanent ground residual displacements (PGRD) in the near source region is provided. The estimated ground motions are validated with that obtained from damage values.
The 500-800 km long segment located between the rupture zones of 1905 Kangra (M W 7.8) and 1934 Bihar-Nepal earthquake (M s 8.3) known as central seismic gap has not generated any great event since historic times. The objective of the present study is to simulate displacement time histories in the Garhwal-Himalayan region for a hypothetical great earthquake in the seismic gap using spectral finite element method. The orientation of the rupture plane, slip field and rupture velocity are modelled as random variables and ensemble of ground motions have been simulated. Contour maps of peak ground displacement (PGD) and peak ground residual displacement (PGRD) are provided in the epicentral region. The statistics of PGD at important cities and towns in the epicentral regions have been presented.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.