Ground-Motion Model for Deep Intraslab Subduction Zone Earthquakes of Northeastern India (NEI) and Adjacent Regions

Abstract

ABSTRACTIn this study, a ground-motion model (GMM) for deep intraslab subduction zone earthquakes in northeastern India (NEI) and adjacent regions, including portions of Bangladesh, Bhutan, China, Myanmar, and Nepal, is developed. Strong-motion data for deep intraslab earthquakes in NEI are very sparse, so it is not possible to develop a robust empirical GMM; hence, we used the stochastic point-source model to develop a new GMM. The model is based on ground-motion simulations of 36,500 Mw 5–8 earthquakes and epicentral distances of 50–300 km. We used region-specific key seismic parameters, for example, stress parameter, quality factor, and path duration in ground-motion simulation. Sensitivity analyses were also performed to evaluate the bias of each key seismic input parameter. We compared our GMM with the existing strong-motion data and compared our model with those of Lin and Lee (2008), Abrahamson et al. (2016), and Idini et al. (2017), which were developed for intraslab earthquakes based on VS30 and hypocentral depth. Our model gives higher values compared with their GMMs. Both peak ground acceleration and spectral acceleration values are estimated for NEI and adjacent regions intraslab earthquakes.