Palghar district on Friday morning experienced two very mild intensity earthquakes, with the second one — at 4.3 moment magnitude (Mw) — being the strongest recorded so far. While the two earthquakes struck in a span of six minutes, the shock waves were felt as far as Mumbai, Umbergaon and Vapi.
According to officials from the India Meteorological Department (IMD) and National Centre for Seismology (NCS), New Delhi, the two earthquakes, part of the “swarm of earthquakes” occurring in the region in recent months, struck in quick succession at a depth of 5 km. “While the first earthquake of 3.2 Mw occurred at 11.08 a.m. at latitude 20.2 north and longitude 72.9 east, the second earthquake of 4.3 Mw occurred six minutes later at 11.14 a.m., at latitude 20.2 north and 72.8 east,” Kiran Narkhede, scientific assistant, IMD Mumbai, told The Hindu .
Calls from suburbs
While the earthquakes occurred over 100 km from Mumbai, tremors were felt in the city. “Some shockwaves from the second earthquake were felt in Mumbai. We received calls from Mahalaxmi, Goregaon and a few other suburbs, and South Mumbai, Umbergaon and Vapi till evening,” Mr. Narkhede said.
Anxious residents from Wadala, Chembur, Bandra, Powai and Santacruz who felt the tremors called up the Brihanmumbai Municipal Corporation Disaster Control Room. Shona Dias (30), a marketing and communications professional, said, “I was in my office across the Mumbai International Airport, when the ground suddenly shook for around five seconds. Though our office is on the fourth floor, we could distinctly feel the ground shake.”
Abhishek Pathak (29), a businessman based in Bandra, said, “My mother initially felt like there was something wrong with her, but I felt it too. I ran to my balcony to see if everything was fine. It was frightening.”
Mahesh Narvekar, chief officer of the BMC Disaster Management, said people reported feeling a slight tremor from four to five locations. “They made inquiry calls, but there has been no untoward incident.”
No casualties
According to Dr. Vineet Gahalaut, director, NCS, as the magnitude increases, so will the area it is felt over.
“The second earthquake … was the largest mild earthquake to have occurred since November 2018. Many earthquakes of smaller intensities occur every day in the region. We do not expect very big earthquakes to happen there as it is away from the tectonic boundaries,” Dr. Gahalaut said.
There was no casualty or injury. Prashant Narnaware, district collector of Palghar, said, “The first thing we did was to send our teams to schools as students were appearing for the Class X exams. We have already trained teachers and students for what is to be done in case of such tremors.”
Mr. Narnaware said teams were also sent to hospitals, but no casualty has been reported. “We are conducting a continuous survey of the cracks in structures to see how they can be made earthquake-resistant. We have already put up tents, provided tarpaulin sheets, deployed civil defence personnel, and put in place a standard operating procedure,” he said.
Krishnanand Hosalikar, deputy director general (western region), IMD said the earthquake in Palghar and the tremors in Mumbai were felt around the same time. “This is a ‘felt shock’. Where tremors are felt depends … If the depth of earthquake is shallow, it can be felt on a large range. But if depth is more, it is more localised. It also depends on magnitude, soil type, structures … some people may not feel it at all.”
