[1]XU Zhishuang,REN Jing,TAN Zhuantiao,et al.Determination of the Long-axis Direction of the Seismic Influence Field Using the Strike of the Focal Mechanism Solution[J].Journal of Seismological Research,2022,45(01):88-99.[doi:10.20015/j.cnki.ISSN1000-0666.2022.0010
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Journal of Seismological Research[ISSN 1000-0666/CN 53-1062/P] Volume:
45
Number of periods:
2022 01
Page number:
88-99
Column:
Public date:
2022-01-20
- Title:
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Determination of the Long-axis Direction of the Seismic Influence Field Using the Strike of the Focal Mechanism Solution
- Author(s):
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XU Zhishuang; REN Jing; TAN Zhuantiao; GAO Xiaoyue; CHEN Yahui; YANG Zhigao; LI Zhiqiang
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(China Earthquake Networks Center,Beijing 100045,China)
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- Keywords:
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seismic influence field; long-axis direction; focal mechanism; isoseismal map; meizoseismal area
- CLC:
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P315.94
- DOI:
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10.20015/j.cnki.ISSN1000-0666.2022.0010
- Abstract:
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In order to evaluate the practicability of using the strike of the focal mechanism solution as the long-axis direction of the seismic influence field,145 destructive earthquake cases from 1970 to 2020 were taken as the research samples.The deviation between the strikes of the focal mechanism solutions and the long-axis directions of the meizoseismal areas has been studied.It is found that the average difference between the strikes of the focal mechanism solutions and the long-axis directions of the meizoseismal areas is 17.0°.Of all the earthquake cases,the strike-slip/near strike-slip,reverse,and normal faults account for 56.6%,19.3% and 6.2%,respectively.And average differences between strikes of the focal mechanism solutions of these earthquakes and the long-axis directions of the meizoseismal areas are about 16.4°,16.2° and 20.6°.In general,the earthquake cases whose difference between the strikes of the focal mechanism solutions and the long-axis directions of the meizoseismal areas less than 30° takes a percentage of 82.8%,indicating that the method is feasible.And then,the differences between the strikes of the focal mechanism solutions of the historical strong earthquakes occurring near the epicenter of the earthquake samples and the long-axis directions of the meizoseismal areas of 50 strong earthquakes with obvious isoseismal long-axis direction from 2010 to 2020 were statistically studied.The results show that among the 50 earthquakes,there have been historical earthquakes within 30 km of the epicenters of 13 earthquakes and the difference between the strike of the focal mechanism solutions and the long-axis direction of the meizoseismal area of 8 cases(62%)is within 30°.Therefore,if a historical strong earthquake has ever occurred within 30 km from the epicenter of the current earthquake,the direction of the focal mechanism solution of the historical strong earthquake and the strike of the active fault nearby can be comprehensively considered to determine the direction of the long-axis direction of the seismic influence field.