Spatial variation of seismicity parameters across India and adjoining areas
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- 作者：Sreevalsa Kolathayar (1) sreevals@civil.iisc.ernet.in
T. G. Sitharam (1)
K. S. Vipin (2) - 关键词：India – ; Earthquake catalog – ; Moment magnitude – ; Seismicity – ; b Value
- 刊名：Natural Hazards
- 出版时间：February 2012
- 出版年：2012
- 期刊代码：33_0921030X
- 类别：soc
- 卷：60
- 期：3
- 页码：1365-1379
- 数据来源：sp
摘要
An attempt has been made to quantify the variability in the seismic activity rate across the whole of India and adjoining areas (0–45掳N and 60–105掳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掳脳1掳) 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.