Abstract

The Central Himalaya is one of the most seismically active regions and has been the focus of several studies. This research aims to estimate the seismic hazard in the region using the Gumbel-I distribution. Seismic data are obtained from the International Seismological Center (ISC) catalog from 1964 to 2023, covering an area between longitudes 80° to 88° E and latitudes 26.5° to 30.5° N. A total of 1614 events, in body-wave magnitude (mb) units, are finalized for analysis. Using K-means clustering, the region is divided into six clusters and named 1 to 6, from west to east. The study shows the maximum probable annual magnitudes 4.8, 4.7, and 4.6, respectively for the clusters 1, 6, and 4 and its lowest value 3.8 in cluster 2. In addition, the shortest return periods are obtained in cluster 1 (7.0, 24.1, and 86.2) and in cluster 4 (7.8, 21.6, and 61.4) years, respectively, for magnitudes 5.5, 6.0, and 6.5. Thus, clusters 1 and 4 are seismically active. The return period for the Gorkha earthquake (6.9 mb) in cluster 4 is estimated to be 142.7 years, with 30% probability of reoccurrence within 50 years and 51% probability in 100 years. Clusters 2 and 5 show moderate seismic behavior. With a higher value of 10% probability of exceedance (6.28, 25.17, and 101.38 years) for magnitudes 5.5, 6.0, and 6.5 points out that cluster 3 is the most stable seismic region. This research provides insight into regional seismic hazards, aiding in preparedness and mitigation planning.