Role of attenuation relationship in shaping the seismic hazard
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- 作者：K. Mohan (1) kapil_geo@yahoo.co.in
A. Joshi (2) anushijos@yahoo.co.in - 关键词：Attenuation relationship – ; Peak ground acceleration – ; Seismic hazard – ; Standard deviation
- 刊名：Natural Hazards
- 出版时间：January 2012
- 出版年：2012
- 期刊代码：33_0921030X
- 类别：soc
- 卷：60
- 期：2
- 页码：649-670
- 数据来源：sp
摘要
Attenuation relationships are commonly used for engineering studies to estimate the peak ground acceleration values. This paper presents the role of attenuation relationship in defining the seismic hazard in an area. It is seen that the seismic hazard in an area, which is calculated using attenuation relationships, is mostly controlled by the type of attenuation relationship used in the study. The present work aims to study the effect of attenuation relationship on seismic hazard study. In the present work, seismic hazard maps have been prepared in the seismically very active northeast Himalaya using the approach given by Joshi and Patel (Tectonophysics 283:289–310, 1997). The attenuation relationships of Jain et al. (2000), Sharma (2000), Joyner and Boore (Bull Seism Soc Am 71:2011–2038, 1981) and Abrahamson and Litehiser (Bull Seism Soc Am 79:549–580, 1989) have been considered in the present study. Among all considered attenuation relationships, the Abrahamson and Litehiser (Bull Seism Soc Am 79:549–580, 1989) attenuation relationship gives the least root mean square error between the recorded and calculated peak ground acceleration values. Therefore, the same has been used to define attenuation characteristic of the region. The mean and standard deviation of peak ground acceleration values at all the observation points due to above-mentioned attenuation relationships in the NE Himalayas are calculated. The study shows that the Zone III covers an area of 81,000 km2 and Zone II of 96,000 km2 in the map prepared using the mean peak ground acceleration values, whereas the area of Zone IV increases by 40,000 km2 when the map is prepared by adding the standard deviation values in the mean peak ground acceleration values, and only Zone II is left with 183,000 km2 when the standard deviation values are subtracted from the mean. This high standard deviation is due to the difference in the peak ground acceleration values obtained from different events. This study shows that a rigorous test needs to be done for selecting attenuation relationship for any hazard study in a given area.