Big quake unlikely, but caution needed: Report

A joint report by two government agencies has formally stated that ongoing seismic activity in Palghar is an “earthquake swarm”, implying that a strong earthquake is unlikely in the region. But it also says that it’s not known how long the tremors will continue.



The study, based on analyses of field stations, reveals that the tremors are clustered in a small region of 5x10km2 south of Talasari, almost along NH8. The report states that a majority of the quakes occurred at shallow depths, were felt locally and were associated with a rumbling sound. “Thus, it appears that the current activity is an earthquake swarm and hence it is unlikely that it can lead to a strong earthquake. Previous (such) episodes in peninsular India indicate that it may continue for a few more days or months. In most earthquake swarm cases, quake activity quickly increases, but slowly decreases in a zigzag manner, that is while decreasing, there may be a few occasional lowmagnitude earthquake bursts in the sequence,” states the report (see graphic).

Prepared by the National Centre for Seismology (NCS) under the Union ministry of earth sciences and the regional meteorological centre (RMC, Mumbai), the report has been submitted to the state government.

NCS director Vineet Gahalaut said, “We are not absolutely saying that a big earthquake will not occur, but then if we look at certain characteristic features, it looks unlikely. A few days back we witnessed that tremor activity was coming down, but then again the tremors started. It looks like they are not dying down as of now.”

Four seismometers are installed in the affected region for real-time updates. Now, there’s a plan to set up a permanent seismological observatory in Palghar, for which the state government has agreed to provide land, said IMD’s K S Hosalikar. “We are planning a couple of more seismometers for nearby dams,” he said.