Research Roundup
Monitoring hydrologically influenced seismic processes in Palghar region using Horizontal-to-Vertical Spectral Ratio (HVSR) analysis.
Murarishetti S, Kumar VP, Sivaram K, Shekar M, Kumar P.
JOURNAL OF SEISMOLOGY
The study examines seasonal changes in shallow subsurface properties in the Palghar earthquake swarm region of western India. Earthquake recordings from 6 broadband stations were analyzed using EHVSR, SSR, and HVSR inversion methods during pre-monsoon and monsoon/post-monsoon periods. The results show measurable seasonal changes in resonance frequency, amplification, shear-wave velocity, and VP/VS ratio, while deeper structures remain relatively stable. The strongest variations were observed near the earthquake swarm nucleation zone, indicating possible hydrological influences.
Fig: Spatial distribution of fundamental resonance frequency (f₀) in the Palghar earthquake swarm region during pre-monsoon and post-monsoon periods, highlighting seasonal variations in shallow subsurface seismic response.