BENGALURU:The next time you experience tremors in the state, don’t panic. Karnataka, on an average, records four to five mild tremors every month and these don’t last for more than a few seconds. The highest number of tremors recorded per year are in Vijayapura and Bagalkot. The two districts recorded 45 mild tremors in the last one year.
Karnataka State Natural Disaster Monitoring Centre (KSNDMC) gets a real time alert on such mild quakes with the magnitude less than 1 to 4 on the Richter scale. The centre has installed seismic record systems at 13 places across the state.
“Despite being in a low-risk seismic zone of 2 and 3, Karnataka is one of the few states in the country to have taken safety measures,” Dr G S Srinivasa Reddy, director, KSNDMC, told Express.
According to him, all river beds form a major fault line (the surface of a fault fracture along which the rocks have been displaced) in the state, including the Arkavathy bed in Bengaluru. Reddy, however, said there is no need to panic as the tremors felt in the state measure less than 5 in magnitude on the Richter scale.
The last big recorded earthquake in Karnataka was in Ballari in 1863, measuring 6.5 on the Richter scale, Reddy said, noting that in the past five years they have not recorded anything beyond 4 on the Richter scale.
Some of the active seismic zones in the state include the Western Ghats, coastal areas which come under zone 3 and all rivers and reservoirs including KRS, Supa, Harangi and Almatti among others. In the Deccan Plateau, Koyna reservoir in Maharashtra falls under zone 4 which is a more active seismic zone. “This is a reservoir-induced seismic zone,” Reddy said, adding that “More pressure is exerted on the largest fault line in the Deccan Plateau on which Koyna is built.”
Vijayapura and Bagalkot recorded 45 tremors in the last one year because of the presence of Almatti reservoir
http://www.newindianexpress.com/states/karnataka/State-in-Low-risk-Seismic-Zone/2015/04/29/article2788714.ece
