Probabilistic Seismic-Hazard Estimation for Peninsular India

Abstract

Peninsular India (10.0Њ N-28.0Њ N; 68.0Њ E-90.0Њ E) is one of the oldest and seismically most stable landmasses of the Indian plate. Recent seismic history, however, shows that more than five damaging earthquakes with magnitudes greater than M w 6.0 have occurred in this region, highlighting the importance of seismichazard assessment for the region. This article estimates the probabilistic seismic hazard associated with peninsular India with a zoneless approach incorporating the observed seismic activity and known geological characteristics of the region. The seismicity parameters for hazard assessment have been estimated incorporating completeness criteria for various spans of the catalog data. The spatial and temporal variations of seismic activity have been modeled using different source models. Seismic source zones for the region have been defined on the basis of large-scale geological features, which are used for assigning the maximum possible earthquake potential. Due to the poorly known attenuation characteristics of the study region, three appropriate attenuation models have been used for the estimation of groundmotion parameters. Hazard maps for peninsular India have been developed using a convolution scheme based on weighting and incorporating various uncertainties involved while modeling different parameters. The comparison of the probabilistic seismic-hazard map developed herein with the hazard map specified in the Indian Standards shows that the design parameters in the Indian Standards may significantly underestimate the seismic hazard in some regions of peninsular India.

Estimation of peak ground acceleration and spectral acceleration for South India with local site effects: probabilistic approach

“…The seismic hazard estimation for Peninsular India was previously attempted by Jaiswal and Sinha (2007) and their study area starts from 10 • N. In the present study, the study area selected is from 8 • N and the earthquake data and details of seismic sources were collected for an area of about 300 km from the boundary of study area, as per Regulatory Guide 1. 165 (1997).…”

“…About 189 active seismic sources, which were associated with earthquakes of moment magnitude 4 and above, were identified in the study area. The earthquake catalogue for this study contains 598 events with moment magnitude 4 and above against 184 events considered by Jaiswal and Sinha (2007). In the current work data until 2006 was considered where as Jaiswal and Sinha (2007) had considered the data till 2002.…”

“…The earthquake catalogue for this study contains 598 events with moment magnitude 4 and above against 184 events considered by Jaiswal and Sinha (2007). In the current work data until 2006 was considered where as Jaiswal and Sinha (2007) had considered the data till 2002. Moreover the present study used a regional attenuation relationship developed by Raghukanth (2004), whereas, Jaiswal andSinha (2007) gave 50% weightage to this relationship and the rest to other attenuation relations.…”

“…In the current work data until 2006 was considered where as Jaiswal and Sinha (2007) had considered the data till 2002. Moreover the present study used a regional attenuation relationship developed by Raghukanth (2004), whereas, Jaiswal andSinha (2007) gave 50% weightage to this relationship and the rest to other attenuation relations. The variation of the spectral acceleration at 1 s, with 10% and 2% probability of exceedance in 50 years, for the entire study area is also provided in the present study.…”

Site specific design response spectrum proposed for the capital city of Agartala, Tripura

“…This approach is simple and provides unarguable lower limit for M max (Wheeler 2009). This incremental technique has been used by various researchers to estimate the seismic hazard in India (Jaiswal & Sinha 2007a, 2007b, 2008Menon et al 2010;NDMA 2010;Roshan & Basu 2010). Method-C: Method to estimate M max proposed by Kijko and Sellevoll (1989) is applicable only when the 'b' value of seismicity parameter of the region is known.…”