张家口地区近年中小地震震源机制解及应力场反演

地震 ›› 2019, Vol. 39 ›› Issue (1): 11-19.

张家口地区近年中小地震震源机制解及应力场反演

王曰风, 张秀萍, 李峰, 马利军, 宋晓煜, 刘燕翔, 张珊珊

河北省地震局张家口中心台, 河北张家口 075000

收稿日期:2017-09-28 出版日期:2019-01-31 发布日期:2019-01-31
作者简介:王曰风(1974-), 男, 甘肃民勤人, 高级工程师, 主要从事地震学和地震分析预测综合研究等工作。
基金资助:
河北省地震局地震科技星火计划项目“晋冀蒙交界地区典型盆地孕震动力学模型构建(DZ2016062
1076)”

Focal Mechanism Solutions and Stress Field Inversion of Recent Medium-small Eearthquakes in Zhangjiakou Area

WANG Yue-feng, ZHANG Xiu-ping, LI Feng, MA Li-jun, SONG Xiao-yu, LIU Yan-xiang, ZHANG Shan-shan

Hebei Seismological Bureau, Zhangjiakou Central Station, Hebei Zhangjiakou 075000, China

Received:2017-09-28 Online:2019-01-31 Published:2019-01-31

摘要/Abstract

摘要： 利用垂直向Pg和Sg波最大振幅比方法, 计算得到张家口地区2007—2015年发生的中小地震震源机制解; 通过系统聚类分析, 研究震源机制分布特征与断裂活动的关系, 并采用网格搜索法对张家口地区的现今地壳应力场进行反演, 得到了较为精确的张家口地区的构造应力场。结果表明: 主压应力轴的走向范围: 211°～223°, 即NE—SW向; 主张应力轴的走向范围: 323°～332°, 即NNW—SSE向, P轴、 T轴都近于水平; 两组节面的走向分别为N18°E向和近EW向(N83°E), 破裂以水平走滑为主。

关键词: 震源机制, 系统聚类分析, 网格搜索法, 构造应力场, 张家口地区

Abstract: Based on the maximum amplitude ratio of vertical Pg and Sg waves, the focal mechanism solutions of medium-small earthquakes in Zhangjiakou area from 2007 to 2015 are obtained. According to systematic cluster analysis, the relationship between distribution characteristics of the focal mechanism and fault activity is discussed. In addition, grid search method is employed for inversing the crustal stress field in the Zhangjiakou area. Ultimately, the tectonic stress field in Zhangjiakou area is obtained accurately. The results show that the strike of the principal compressive stress is NE-SW, and ranges from 211 to 223 degrees. The strike of the principal tensional stress is NNW-SSE with a range of 323~232 degrees, which indicates P and T axes are nearly horizontal. The joint strikes of the two groups are N18°E and N83°E respectively. The break mode is dominated by horizontal strike slip.

Key words: Focal mechanism, Tectonic stress field, Systematic cluster analysis

中图分类号:

P315.7

王曰风, 张秀萍, 李峰, 马利军, 宋晓煜, 刘燕翔, 张珊珊. 张家口地区近年中小地震震源机制解及应力场反演[J]. 地震, 2019, 39(1): 11-19.

WANG Yue-feng, ZHANG Xiu-ping, LI Feng, MA Li-jun, SONG Xiao-yu, LIU Yan-xiang, ZHANG Shan-shan. Focal Mechanism Solutions and Stress Field Inversion of Recent Medium-small Eearthquakes in Zhangjiakou Area[J]. EARTHQUAKE, 2019, 39(1): 11-19.

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