In this article, a stochastic finite fault source model is calibrated to estimate ground motion in northeastern India for intermediate depth events originating in the Indo-Burmese tectonic domain. A total of 47 three-component accelerograms from eight events with magnitudes ranging from M w 4.8-6.4 are used to estimate the input source and site parameters of the finite fault source model. Key seismic parameters such as stress drop (Δσ) and site amplification function are determined from the recorded strong motion data. The obtained stress drop of the eight recorded events lies in between 105 and 165 bars. © 2012 Springer Basel.

S T G Raghukanth

Department Of Civil Engineering

SEISMOLOGICAL MODELS

SITE AMPLIFICATION

STRESS DROP

STRONG GROUND MOTION

Subduction zones

Drops

Earthquake effects

Faulting

Seismology

Stochastic systems

Stochastic models

earthquake magnitude

Fault

ground motion

numerical model

Stochasticity

STRONG MOTION

subduction zone

India

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Pure and Applied Geophysics

The present study focuses on developing a 3D crustal velocity model and applying it to perform ground motion simulations for North East India. The study region encompasses area between 89°E to 97°E longitude and 22°N to 30°N latitude. The calibration of the material property is based on 48 shear wave profiles available for the region along with the geotectonic features reported in the literature. The 3D material model arrived from the study is implemented in a finite element framework for ground motion simulations. The developed model is validated using the strong motion data available for four events; 1988&nbsp;Mw 7.2 India–Bangladesh earthquake, 2011&nbsp;Mw 6.3 India–Myanmar earthquake, 2013&nbsp;Mw 5.5 Assam earthquake and Mw 5.2 Bhutan earthquake. The simulations are able to capture the prominent features of the recorded data up to 2Hz. Hence, the developed model can be implemented for estimating ground motions (&lt;&nbsp;2Hz) in the north eastern region of India. The simulated results can be used to estimate region-specific hazard and the displacement-based design of structures. © 2018, © 2018 Taylor &amp; Francis Group, LLC.

Journal of Earthquake Engineering

3D Crustal Velocity Model for Ground Motion Simulations in North-East India

In this article, a study on development of ground motion prediction equations (GMPEs) is undertaken for seismically active regions in India. To derive the equations, the seismically active regions are divided into four units based on seismotectonic setting and geology. Due to lack of strong motion data, a stochastic finite-fault simulation method is used for generating a complete synthetic database with respect to magnitude and distance. The input parameters in the stochastic seismological model, such as site amplification and stress drop, are first derived from the past strong-motion data. A total of 236 three-component records from 62 earthquakes with magnitudes ranging from Mw 3.4 to 7.8 are used to calibrate the seismological model. The obtained stress drops of these 62 events lie in between 60 and 165 bars. With the help of a large synthetic database generated from the calibrated seismological model, ground motion relations for 5&nbsp;% damped spectral acceleration are obtained by regression analysis. The developed ground motion relations are compared with the existing GMPEs of the other active regions in the world. Although the proposed equations have trends similar to those of the existing relations, there are some differences attributed to stress drop and the quality factor of active regions in India. These relations will be useful to prepare spectral acceleration hazard maps of India for a given annual probability of exceedance. © 2014, Springer Basel.

Ground Motion Relations for Active Regions in India

This article estimates the ground motion during the January 26, 2001 Gujarat, India earthquake by spectral finite element method. The SPECFEM3D-GLOBE package which models the complete three-dimensional wave velocity structure, ellipticity, topography, and bathymetry is used to simulate the ground motion on a global scale. The Earth is modelled with 553.4 million grid points. Displacement time histories are simulated at various stations in the epicentral region. A contour map of permanent ground displacements in the near source region is provided. The obtained results are validated by comparing them with recorded peak ground velocity data and field observations. © 2012 Copyright A. S. Elnashai &amp; N. N. Ambraseys.

Ground motion simulation for January 26, 2001 Gujarat earthquake by spectral finite element method

India's urban population has increased in the recent times. An earthquake near an urban agglomeration has the potential to cause severe damage. In this article, seismicity parameters for region surrounding important urban agglomerations in India are estimated. A comprehensive earthquake catalogue for the region (6°E-42°E latitude and 60°N-100°N longitude) including historic and pre-historic events has been compiled from various sources. To estimate the parameters, past earthquake data in a control region of radius 300 km has been assembled to quantify the seismicity around each urban agglomeration. The collected earthquake data is first evaluated for its completeness. From combined (historical and instrumental) data, the seismicity parameters b-value, seismic activity rate, λ and maximum expected magnitude (mmax) have been obtained from the methodology proposed by Kijko and Graham (1998). The obtained activity rates indicate that region surrounding Guwahati urban agglomeration is the most seismically active region followed by Srinagar, Patna, Amritsar and Chandigarh. © 2011 Springer Science+Business Media B.V.

Bulletin of Earthquake Engineering

Seismicity parameters for important urban agglomerations in India

Bulletin of the Seismological Society of America

Path Durations for Use in the Stochastic-Method Simulation of Ground Motions

Tectonophysics

Large and great earthquakes in the Shillong plateau–Assam valley area of Northeast India Region: Pop-up and transverse tectonics

Seismological Research Letters

Indian Strong Motion Instrumentation Network

Stochastic Finite Fault Modeling of Subduction Zone Earthquakes in Northeastern India