Flat-File Compilation of Strong Ground-Motion Intensity Measures for Crustal Earthquakes in the Indian Region

This study presents a uniformly processed ground‐motion flat-file for earthquakes recorded across India, comprising standardized intensity measures (IMs) and associated metadata. The primary objective is to develop a comprehensive, consistent database aligned with international practices for Ground Motion Model (GMM) development. Such standardized flat-files are essential for parametric studies, GMM derivation, and seismic hazard assessment. Thus, we compile a comprehensive dataset of ground-motion IMs, including peak ground motion parameters (acceleration (PGA), velocity (PGV), displacement (PGD)), spectral acceleration (SA), Fourier amplitude spectra (FAS), Effective Amplitude Spectrum (EAS), Arias intensity (AI), cumulative absolute velocity (CAV) significant duration (SD), Acceleration Spectrum Intensity (ASI), Velocity Spectrum Intensity (VSI), and Characteristic Intensity (Ic). These metrics are derived from approximately 778 manually processed strong-motion records from 195 earthquakes, with moment magnitudes (Mw) ≥ 2.0 and epicentral distances (REpi) < 600 km, recorded at 254 seismic stations across India between 1986 and 2018. A step-by-step waveform processing protocol was implemented to ensure consistency and accuracy. The reliability of the processed IMs was verified through residual analysis of FAS ordinates against an empirical model. This is the first study of its kind in India to provide a uniformly processed IM database, offering a valuable resource for applications in engineering seismology, seismic hazard analysis, and earthquake engineering.