Monsoonal rainfall induced shallow earthquake Swarm in the Amravati district of the central India

Abstract

Sadrabadi and Zilphi villages of Dharni Taluka in Amravati district, Maharashtra, experienced small magnitude earthquakes between September 1, 2018 and December 9, 2018. We deployed a four station temporary network of three component broadband seismographs to understand and characterize the earthquake sequence. We find that the short lived (~2 months) micro-earthquake (M ≤ 2.4) swarm, accompanying rumbling sound, was highly clustered (3×3 km2) and occurred at extremely shallow depth (<0.4 km). Analysis of the data reveal that the earthquake swarm might have been induced by the percolation of monsoonal rainwaters (reaching ~100 mm/day) through the cracked volume of soil/rock, associated with the fault system of the Narmada Son failed rift region. Besides revealing the science of earthquake swarm and characterizing it, the monitoring of earthquake swarm and its analysis contributed significantly in reducing the public panic.