Ministry pushes study on quakes

[1]

Raji P. Shrivastava [1]

The ministry of earth sciences is making a major push to study earthquakes as also pick up warning signals to predict earthquakes .

Dr Shailesh Nayak, secretary, ministry of earth sciences, told journalists that a team of scientists had drilled a 1.5 km deep bore hole near the Koyna dam. This is the first of four boreholes being dug to monitor tremors and other seismic signatures of impending earthquakes.
A deep bore hole will provide direct observational data and contribute to earthquake hazard reduction.
Scientists have found a granite basement less than a kilometre below the Deccan Traps near the Koyna dam in Maharashtra.
“There were no sedimentary rocks at the place where we drilled the bore-hole. Rather, we hit the granite basement after drilling around 1000 metres in the Deccan Traps area,’ said Mr Nayak.
The secretary said that the cores recovered from the borehole have so far revealed a flood basalt pile comprising several layers of lava flows.
“No sedimentary rock has been observed,” he explained observing that the absence of sedimentary rocks indicates that the area was not under the sea and also ruled out the possibility of oil reserves in this region. The drilling is being carried out as part of a major `500 crore scientific programme funded by the ministry to investigate seismcity in the Koyna-Warna region. Koyna is looked upon as a “classical site” of Reservoir Triggered Seismicity with earthquakes having occurred since the impoundment of the reservoir in 1962 including the largest 6.3 on the Richter scale on December 10 1967.
The RTS increased following the monsoon period and almost every year one or more earthquakes of magnitude above 4 have occurred. Scientists from a number of institutes including the Pune University, Benaras Hindu University, National Geophysical Research Institute and the Geological Survey of India are involved in the study.