Deterministic Seismic Hazard Analysis of Tindharia Site Using ANBU-13 GMPE

Abstract

India has been prone to several major to minor earthquakes from ancient times. Although the prediction of earthquake time is unreliable, prior seismic hazard studies may help against significant earthquake loss. Seismic hazard studies effectively exhibit solutions for future events at a particular location by combining different mathematical models and addressing uncertainties and challenges. This paper has carried out the seismic hazard analysis of the Tindharia landslide, Darjeeling Sikkim Himalayas and its surroundings based on the deterministic approach considering an updated historic earthquake database and models within a 300 km radius. The method determines the worst-case ground motion for the best maximum magnitude (Mmax) at the shortest source-to-site distance (Rmin). The hazard analysis was carried out using linear seismo-tectonic data considering faults, lineaments and shears zones collected from different sources. The Mmax is calculated using the five most widely used empirical relations involving magnitude and fault rupture length. The maximum among them is considered the maximum magnitude of the fault. The peak ground acceleration for each source has been calculated using the ANBU-13 attenuation equation at 30, 50 and 75 km focal depth. The controlling earthquake of the site is carried out by comparing the levels of PGA produced by various earthquake sources. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.