Maharashtra Logs 29 Small Earthquakes in a Fortnight: What an Earthquake Swarm Is

Maharashtra has experienced a spate of small earthquakes over the last fortnight, according to local reports. Of the 29 tremors recorded in this period, 24 were in and around Nashik, four were in Palghar and one was in Nagpur. None was particularly strong — the largest, in Nagpur on August 8, measured magnitude 4.3 — but all were shallow, occurring at depths of around 5-8 km.

Seismologists call this pattern of many small quakes clustered in one area over a short period an earthquake swarm. It is not a new phenomenon for the state: Maharashtra has experienced such swarms often before, The Hindu's explainer notes.

An earthquake is a sudden movement of rocks along a fault — a fracture or region of weakness in the Earth's crust. In some places, friction can prevent two blocks of rock from sliding past each other.