Ground shaking hazard assessment in Jharkhand state, India, using deterministic approach

Jharkhand, a mineral-rich state in India, faces specific seismic risks that necessitate thorough assessment due to its significant mining activities. This study conducts a detailed deterministic seismic hazard analysis (DSHA) to support earthquake-resilient infrastructure and hazard management. The study computes essential ground motion parameters and predicts potential earthquake scenarios by integrating geological and seismological data, including fault structures, historical seismicity, and crustal properties. Peak ground acceleration (PGA) was calculated for a return period of 2475 years, assuming a 2% probability of exceedance over 50 years. Deterministic evaluations of PGA, spectral acceleration (SA), and response spectra were performed for different periods, utilizing seismic data from various sources up to 2023. To accurately capture regional tectonic conditions, 13 ground motion prediction equations (GMPEs) were applied. The study area was divided into grids of 0.100° × 0.100° and analyzed using ArcGIS and MATLAB. A logic tree approach, incorporating weighted GMPEs, was employed to address uncertainties in the hazard assessment. The results indicate PGA values of up to 0.18 g, influenced significantly by major tectonic structures, including the Debagram Bogra fault, Singhbhum Shear Zone, Northern and Southern Purulia shear zones, Main frontal thrust (MFT), Main central thrust (MCT), and critical faults such as F233, F1329, F2423. SA values for durations ranging from 0.0 to 4.0 s were compared with Indian Standards, revealing important insights for aligning earthquake-resilient infrastructure in Jharkhand. These findings provide a robust basis for enhanced safety measures and hazard mitigation strategies in future development.