4.9 quake jolts city
An earthquake measuring 4.9 on the Richter Scale shook Pune, Mumbai and several other parts of the state around 11 on Saturday morning, with its epicentre about 5.5 km from Goshatwadi village near the Koyna dam in Patan taluka of Satara district. Officials of India Meteorological Department (IMD) said the earthquake was of minor intensity and that it would be inappropriate to treat the shocks as "pre-strokes of a bigger magnitude earthquake."
The earthquake was felt in Mumbai, Satara, Karad and many parts of Western Maharashtra besides other places. Talking to The Indian Express, P N Mohanan, senior scientist, instruments division, IMD and director of Seismological Observatory Pune, said, "The tremors cannot be treated as pre-strokes of a bigger magnitude earthquake. Today's earthquake traces its epicentre to Koyna dam, which is a known source of tremors."
No loss of life or property was reported.
Commenting on whether Saturday morning tremors had any relation to the earthquake in Indonesia two days ago, Mohanan said, "Prima-facie, I see no relation between the earthquakes in Indonesia and other places with this one. What makes the Koyna dam area a known source of earthquakes are faultlines 10-15 km beneath the earth's surface. And Koyna can quake irrespective of earthquakes taking place anywhere in the world."
He said that at 4.9 Richter Scale, the shocks could have been recorded by seismographs located as far as Chennai.
The Koyna region that falls in earthquake zone-4 witnesses minor shocks of intensity of 2.1- 2.2 almost once or twice a month, which are not felt by people but are recorded by seismographs, said Mohanan.
"There has always been an argument as to whether it is the huge water body at Koyna dam that causes these tremors. But in my opinion, the water body is too small compared to large faultlines located 10-15 km below earth's surface and run through hard, base rock," he added.