Spatial Analysis and Predictive Modeling of Natural Seismic Activity: A Smoothed Seismicity Approach

ABSTRACT The study uncovers significant disparities in seismic activity patterns between Kerala and Pondicherry. Kerala demonstrates a higher incidence of seismic events on land, particularly concentrated in central Kerala, where multiple faults and lineaments are prevalent. The reactivation of ancient faults emerges as a crucial contributor to the escalated seismicity observed in the region. In addition to ancient fault reactivation, Kerala’s seismicity is influenced by hydrological stress, particularly triggered seismicity induced by the filling of the Idukki reservoir. Regarding Pondicherry, the region displays a distinctive seismic profile characterized by both onshore and offshore seismic activity. Various studies document the reactivation of ancient faults in the area, particularly evidenced by the 2001 earthquake near Pondicherry. The NE-SW and NNE-SSW fault-bounded ridges and depressions, extending from land into the offshore sea, have contributed to the seismic activity. The region is under the influence of land-ocean tectonics (LOTs), attributing moderate seismicity to compressional stress acting on the Indian Plate. Smoothed seismicity analysis supports these observations, highlighting higher G-R parameters in Pondicherry indicative of LOTs along the Eastern continental margin of India (ECMI). Additionally, elevated earthquake probability near Mullaperiyar Dam in the Kerala region underscores the significant role of hydrology in seismic events. In short, the distinct seismic patterns observed in Kerala and Pondicherry underscore the complex relationship of geological, hydrological, and tectonic factors shaping seismic activity in these regions. Reactivated ancient faults, hydrological stress, and land-ocean tectonics stand out as primary contributors to seismic activity, underscoring the intricate nature of assessing and addressing seismic hazards in these regions.