Focal Mechanism Solution and Stress Field Inversion of Small and Moderate Earthquakes in North Henan Province and Its Adjacent Region

详细信息   

• 责任者：Xin Hailiang (Geophysical of Exploration Center ; CEA ; Zhengzhou 450002 ; China) ; Fang Shengming
• 刊名：Journal of Seismological Research
• 出版年：2012
• 卷期：35(2)
• 关键词：强震 ; strong earthquakes ; 小震 ; small seisms ; 震源机制 ; focal mechanism ; 河南 ; Henan Province
• 页码：p.184-189
• 图表：2 illus., 2 tables, 23 refs.
• 分类号：0500
• issnNo：ISSN1000-0666
• isbnNo：CN53-1062/P

摘要

///Based on the data of digital seismic wave recorded by regional seismic network from 1985 to 2008, the focal mechanism solutions of 145 small and moderate earthquakes which occurred in North Henan Province and its adjacent regions were determined by the amplitude ratio of Pg and Sg in vertical component records with clear initial motion of P-wave. Using the methods of statistic, systematic cluster analysis and grid point test, the authors analyze the parameters of focal mechanism solutions and calculate the regional mean stress field. The results show that the mainly focal mechanism solutions is strikeslip type, the main stress axis is close to horizon and the main characteristic of the regional tectonic stress field is characterized by horizontal compression in study area. There are some normal and reverse fault types beside of strikeslip type for focal mechanism solutions. On the whole the focal mechanism solutions of small and moderate earthquakes have many types and scattering distribution, which indicates that small earthquakes occurred in random, and the whole controlling of tectonic stress field of North China is weak.