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https://www.ias.ac.in/article/fulltext/jess/098/04/0309-0318

Earthquake prediction; pattern recognition; reservoir-induced seismicity

Anticipating the scale invariance of rock fracturing processes, we applied Keilis-Borok’s algorithm M8, originally designed for identifying times of increased probability (TIPS) of occurrence of strong earthquakes (M < 8.0), retrospectively to Koyna earthquakes which occurred in the region after the impoundment of the Shivaji Sagar reservoir in 1962. The algorithm which enables diagnosis of TIPS from the 7th year onwards after the commencement of the earliest available data set showed that the 5.3 magnitude earthquake of 20 September 1980 indeed occurred within a time of increased probability. This result, apart from its potential application to recognizing future TIPS in the region, points to selfsimilarity between the premonitory patterns of natural and induced earthquakes and to scale-invariant nature of their processes. Further, a typical precursory rise in seismicity followed by a relative quiescence was also found to precede all the three larger earthquakes of the sequence.

V G Kossobokov^{1 2} B K Rastogi¹ V K Gaur^{1 3}

1. National Geophysical Research Institute, Hyderabad - 500 007, India
2. Institute of Physics of the Earth, Bulshaya, Gruzinskaya Street No. 1, Moscow - D 242, USSR
3. Department of Ocean Development, 12, Lodi Road, New Delhi - 110 003, India

Published

December 1989

Manuscript received

20 March 1989

Manuscript revised

21 September 1989