Tremors rock Chennai twice, nuke installations safe

C Shivakumar

Chennai:

Panic gripped Chennai when the city recorded two tremors in the span of two hours sparking tsunami warning and an alert in nuclear installations as well as authorities monitoring the dams.

Station director of Madras Atomic Power station K Ramamurthy told Express that the first tremor whose intensity was 5 milli-G (one milli-g is one thousandth of the acceleration due to gravity) was felt at 14.15 hours soon after the earthquake with an intensity of 8.5 in Richter scale was recorded in Indonesia (2.4 degree North Lattitude and 93.07 degree East Longtitude).

This was way below 10 milli-G , which could trigger an alarm in the nuclear installation, he said, adding that the control room staff were alerted and operations were halted briefly. “We got in touch with Andaman and Nicobar Islands fearing the possibility of tsunami. But Anadaman and Nicobar authorities found everything was and the reactors began to function normally,” Ramamurthy said.

The second tremor, which was felt at 1615 hours after a quake with an intensity of 8.1 at the location 0.8 degree north and 92.4 degree East was trigerred in Sumatra, was also below 5 milli-G and trigerred tsunami alert but was withdrawn after Andaman and Nicobar authorities stated .

However, he said the nuclear establishment has adequate security safeguards and they were put on alert. 

Later, director of seismic unit in meteorology department W B Gopal said that four earthquakes were recorded in Indonesia. The first one was triggered at 1408 hours in Indonesia with an intensity of 8.5 on Richter Scale while the second was felt at 14.31 with an intensity of seven in the Richeter scale with the location 2.65 north and 89.93 degree east longtitude. The third was felt at 14.58 hours at East Indian Ocean with an intensity 6.8 in Richter Scale located at 1.37 degree north and 91.72 degree East while the fourth with the an intensity of 8.1 at Richter Scale with location of 0.8 degree north and 92.4 degree East was felt at 1613 hours. Chennai residents felt the tremors after the first and fourth quake, he added.