Indian scientists to lead global study on quakes at Koyna

Sailesh Nayak (centre), secretary, Ministry of earth Sciences along with Harsh Gupta (left), former secretary, department of ocean development at a workshop on 'Deep Scientific Drilling to Study Reservoir Triggered Earthquakes at Koyna, India' at Hyderabad on Monday. Photo: G. Ramakrishna

Indian scientists will spearhead a major international project which is expected to provide fresh insights into the processes that cause earthquakes.

The project, costing anywhere between Rs.200 crore and Rs.400 crore, will be the first of its kind in the world and is being taken up at the Koyna region in Maharashtra. As part of the project, a 7-km deep borehole drilling has been planned. Koyna is the best known example of reservoir-triggered earthquakes.

The project will be funded mainly by the Ministry of Earth Sciences and supported by other national and international organisations.

To chalk out a blueprint of the project, 70 experts, including 26 from abroad, have gathered at the CSIR-National Geophysical Research Institute (NGRI) here to attend a five-day workshop on ‘Deep Scientific Drilling to Study Reservoir Triggered Earthquakes at Koyna India,' which began on Monday. The project will study the physical, geological and chemical processes and properties of the earthquake zone in real time.

“Unique project”

Secretary, Ministry of Earth Sciences, Shailesh Nayak, who inaugurated the workshop, described it as a unique project. It would provide a better understanding of the earthquake processes and also “what exactly is below the Deccan traps.” Another similar project to drill a deep bore hole in the ocean (Arabian Sea) was also being planned in collaboration with the United States.

In his presentation, the former secretary, Department of Ocean Development, Harsh Gupta termed Koyna a “classical site' of Reservoir Triggered Seismicity (RTS). Earthquakes have been occurring since the impoundment of the reservoir in 1962, including the largest RTS event of M 6.3 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. A deep borehole will provide direct observational data and contribute to earthquake hazard reduction.

Acting director of the CSIR- NGRI, Y.J. Bhaskar Rao, and scientist N. Purnachandra Rao said that although the Koyna region was located in ‘stable continental region,' earthquakes were taking place in a localised area. It was like a “mini-laboratory” for studying earthquakes and the results of the proposed project would be applicable in general to earthquakes because the “basic earthquake mechanism is the same.” It would take at least a decade to get the initial results.