Why Maharashtra has seen 24 tremors in 18 days; what experts are studying
NASHIK/PALGHAR: Maharashtra has recorded at least 24 tremors across Nashik and Palghar districts between July 25 and August 12, part of what seismologists are calling an “earthquake swarm” — a cluster of shallow, low-to-moderate quakes without a single dominant mainshock.The activity began on July 25, when nine earthquakes, the strongest measuring 3.2 on the Richter scale, struck Surgana, Kalwan, Dindori and Peth talukas within a 36-hour window. District collector Ayush Prasad said the region falls in Seismic Zone III near a fault line in the Western Ghats, and that such swarms — documented in the area since 1869 — typically occur between July and November.The sequence’s largest event came on July 28: A magnitude 3.9 quake along local fault lines.By July 31, the National Seismological Network had logged around 15 quakes in the belt, ranging from 2.8 to 3.9 magnitude, prompting the National Centre for Seismology to install four round-the-clock monitoring stations in Surgana, Peth, Dindori and Kalwan. Assistant collector Kashmira Sankhe said the solar-powered devices, placed at government Ashram schools and gram panchayat offices, would transmit real-time data to the ministry of earth sciences to enable faster disaster-mitigation decisions.On August 9, a 4.3-magnitude quake jolted Surgana, Kalwan, Deola, Chandwad, Peth, Dindori, Nashik and Niphad talukas, leading collector Prasad to ask residents to inspect homes for cracks and report structural risks.The swarm spread further on August 11, with four back-to-back tremors — 3.2, 3.4 and two more — rattling Jawhar taluka in Palghar district near Dengachimet, keeping residents outdoors past midnight. The same night, four more tremors (2.9, 2.7, 2.0 and 2.8 magnitude) were felt around Shinde and Rahude villages near Saputara. No casualties or major damage have been reported in any of the incidents.What’s driving the swarmOfficials attribute the activity to local stress adjustments and monsoon rainwater seeping into fractured basalt rock, which increases underground pore pressure.Most hypocentres have been recorded at depths of 10 km or less, with epicentres forming a north-south corridor through Surgana, Hatgad, Shinde and Umbarthan down to Peth, Karanjali and Dindori — concentrated north of the Kurduwadi-Sangamner fault lineament.Chief minister Devendra Fadnavis has directed authorities to widen the seismic assessment beyond the ongoing Centre for Seismic Technology study, roping in additional institutions, and to step up awareness drives — particularly among students — in Nashik and Palghar.
