Earthquake Source Parameters of Moderate to Small Earthquake and Scaling Relationships in the Western Himalaya: Seismic Hazard Implication

• DOI: 10.11648/j.earth.20251402.13
• Publication Date: 2025-03-26T03:41:59Z
• Authors: Vedprakash Thakur; Sanjay Prajapati; Birendra Pratap; Uma Shankar; Sudipto Bhattacharje
• Keywords: Seismic microzonation; Earthquake simulation; Types of earthquake

The Northwest Himalayas experiences frequent seismic activity, with numerous moderate events occurring over the past century, leading to several disasters. In present study, we conducted a comprehensive analysis of source parameters for 125 earthquakes local magnitudes (ML) ≥ 4.0 that occurred in northwest region during period from 2013 2019. We analyzed P and S wave spectra using Brune's model investigate self-relation self-similarity area. digital seismograms used this study were recorded by sixteen permanent broad-band stations at hypocentral distances between 10 327 km. average ratio P/S corner frequency is found range 1.1-1.9, suggesting higher wave. static stress drops 0.1 136 MPa median value 9.8 (98 bars). obtained moments 7.49×10<sup>14</sup> 1.15×10<sup>18</sup> Nm (4.0 ≤ Mw 6.0). radii are 388 7073 m. established linear relationship moment magnitudes. scaling relations indicated slight deviation self-similarity. High-stress observed some suggest elevated frictional strength lower strain rates within faults, while may indicate general fault weakness. Although definitive correlation drop was not universally, values also demonstrated drops. Furthermore, decreased increasing moment, depth dependence observed; shallower tended have than deeper ones. While there wasn't clear values, more pronounced observed, indicating generally larger our This implies large could still leave significant on potentially future events. reveals ML all > 4.0. coefficient determination magnitude fit scale be 0.91, which indicates good. Therefore, it concluded newly derived consistent currently region.