GIS in seismic hazard assessment of Shillong region, India

Abstract

The Shillong region falling in north-eastern part of India is developing fast and has witnessed one of the greatest earthquakes of India in 1897 besides several other earthquakes. Seismic hazard assessment of the Shillong and adjoining regions has become pertinent and been carried out with the help of GIS in view of sharp increase in human activities and the proposed developmental works. For this purpose an area has been selected spanning from 24.2° to 26.8°N latitudes and 89.2° to 92.8°E longitudes and is divided into a 0.2° × 0.2° grid-like framework for analysis. Seismic hazard assessment has been performed by employing deterministic seismic hazard assessment (DSHA) approach. Further, 1897 earthquake rupture zone based ground motion estimations were also done in order to examine and compare the intensity converted ground motion and predicted ground motion in the epicentral and nearby areas. Maximum predicted ground motion is found out to be 0.606 g on the rock sites and 0.634 g on the soil sites. The average ground motion on the rock and the soil sites is 0.433 g and 0.26 g respectively. © Springer Nature Singapore Pte Ltd. 2017.