Natural Hazards

, Volume 60, Issue 3, pp 1365–1379

Spatial variation of seismicity parameters across India and adjoining areas

  • Sreevalsa Kolathayar
  • T. G. Sitharam
  • K. S. Vipin
Short Communication

Abstract

An attempt has been made to quantify the variability in the seismic activity rate across the whole of India and adjoining areas (0–45°N and 60–105°E) using earthquake database compiled from various sources. Both historical and instrumental data were compiled and the complete catalog of Indian earthquakes till 2010 has been prepared. Region-specific earthquake magnitude scaling relations correlating different magnitude scales were achieved to develop a homogenous earthquake catalog for the region in unified moment magnitude scale. The dependent events (75.3%) in the raw catalog have been removed and the effect of aftershocks on the variation of b value has been quantified. The study area was divided into 2,025 grid points (1°×1°) and the spatial variation of the seismicity across the region have been analyzed considering all the events within 300 km radius from each grid point. A significant decrease in seismic b value was seen when declustered catalog was used which illustrates that a larger proportion of dependent events in the earthquake catalog are related to lower magnitude events. A list of 203,448 earthquakes (including aftershocks and foreshocks) occurred in the region covering the period from 250 B.C. to 2010 A.D. with all available details is uploaded in the website http://www.civil.iisc.ernet.in/~sreevals/resource.htm.

Keywords

India Earthquake catalog Moment magnitude Seismicity b Value 

Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  • Sreevalsa Kolathayar
    • 1
  • T. G. Sitharam
    • 1
  • K. S. Vipin
    • 2
  1. 1.Department of Civil EngineeringIISc BangaloreBangaloreIndia
  2. 2.Department of Civil, Mining and Environmental EngineeringUniversity of WollongongWollongongAustralia

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