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Nat Hazards (2015) 77:S109S116
DOI 10.1007/s11069-014-1111-x
ORIGINAL PAPER
D. V. Ramana J. Pavan Kumar Asha Chelani R. K. Chadha
M. Shekar R. N. Singh
Received: 28 August 2013 / Accepted: 25 February 2014 / Published online: 7 March 2014 Springer Science+Business Media Dordrecht 2014
Abstract KoynaWarna region in western India is known to be the largest case of the reservoir-triggered seismicity in the world with M6.3 earthquake in 1967. This region continues to be seismically active even after 45 years with occurrences of earthquakes up to M5.0. The porous crustal rocks of KoynaWarna region respond to changes in the prevailing stress/strain regime. This crustal section is highly fractured and is being fed by rivers and reservoirs. It is also subjected to uctuating plate boundary forces and signicant gravity-induced stresses due to crustal inhomogeneities. These changes induce variations in the water level in bore wells before, during and after an earthquake, and their study can help in understanding the earthquake genesis in the region. The ongoing seismicity thus requires understanding of coupled hydrological and tectonic processes in the region. Water table uctuations are a reection of the ongoing hydro-tectonics of the region. The fractal dimension of water levels in the bore wells of the region can be used as measure of the nonlinear characteristics of porous rock, revealing the underlying complexity. In this paper, we present values of correlation dimensions of the water level data in the bore wells using the nonlinear time series methodology. The spatiotemporal changes in the fractal
D. V. Ramana (&) R. K. Chadha M. Shekar R. N. Singh
National Geophysical Research Institute (CSIR), Hyderabad, India e-mail: [email protected]
R. K. Chadhae-mail: [email protected]
M. Shekare-mail: [email protected]
R. N. Singhe-mail: [email protected]
J. Pavan Kumar
Indian National Center for Ocean Information Services (MoES), Hyderabad, India e-mail: [email protected]
A. Chelani
National Environmental and Engineering Research Institute (CSIR), Nagpur, India
Complexity in hydro-seismicity of the KoynaWarna region, India
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dimensions have also been determined. The results show that hydro-seismically the region behaves as a low-dimensional nonlinear dynamical system.
Keywords Seismicity Nonlinear Hydro-tectonics Porous rock
1 Introduction
The seismicity in the KoynaWarna region in western India within the interior of the Indian continental plate started in 1962 after the impoundment of the Koyna...