Shailesh Nayak

Ministry of Earth Sciences, New Delhi

Shailesh Nayak is a Distinguished Scientist in the Ministry of Earth Sciences, Government of India. He obtained PhD degree in Geology from M.S. University of Baroda in 1980. He was the Secretary of the Ministry of Earth Sciences, during 2008–2015. He set up the state-of-the-art tsunami warning system for the Indian Ocean and provided tsunami advisories to the Indian Ocean rim countries. He has pioneered applications of remote sensing to coastal and marine environments and has developed products for coastal management and services for fishery and ocean state forecast. He was instrumental in initiating studies related to reservoir induced seismicity. He is a Fellow of the Indian Academy of Sciences (2014), the National Academy of Sciences, India (2015), the International Society of Photogrammetry & Remote Sensing and Academician of the International Academy of Astronautics. He was conferred the ISC Vikram Sarabhai Memorial Award in 2012.

Shailesh Nayak

Session 1B: Inaugural Lectures by Fellows

Chairperson: M M Sarin, Physical Research laboratory, Ahmedabad

Towards understanding of triggered earthquakes

Triggered earthquakes have been receiving increased attention from the scientific community the world over. Artificial water reservoirs are known to induce seismicity; this is known as Reservoir-Induced Seismicity. The Shivaji Sagar and later the  Warna reservoirs at Koyna have induced earthquakes during the last 50 years, and many studies have been carried out to understand this phenomenon. However, the current models do not explain their genesis as direct observational data along the fault plane are lacking. To understand reservoir-induced seismicity, scientific deep drilling, approximately 5–7 km deep, has been undertaken at Koyna. An exploratory phase has been completed by drilling nine shallow boreholes (up to 1.5 km) and deploying seismometers. These observations provided hypocentral location and disposition of fault zones responsible for these earthquakes. Based on these data sets, a pilot bore-hole of up to 3 km has been drilled, recently. Geophysical measurements to characterise physical properties of rocks, hydrofrac measurements to measure stress regime, and more, were carried out. Geomicrobiological studies have also been undertaken. The results of these studies and future study plans related to reservoir-trigger seismicity will be presented.

© 2017 Indian Academy of Sciences, Bengaluru.