地震工程学报Issue(z2)：157-163,7.DOI:10.3969/j.issn.1000-0844.2015.增刊2.0157
濮阳小震集中区震源机制解与应力场跟踪分析与研究
Tracking Analysis of Focal Mechanisms and Stress Field of Small Earthquake Concentrating Area in Puyang,Henan Province
摘要
Abstract
In the border area of Hebei ,Shandong ,and Henan provinces in north China ,moder‐ate‐to‐strong earthquakes have occurred frequently including the Cixian M L 7 .5 earthquake of 1830 and the Heze M L 7 earthquake of 1937 .In recent years ,moderate earthquakes have occurred fre‐quently in this region ,especially at the border area of Puyang ,Henan Province and Juancheng , Shandong Province .Clusters of small‐to‐moderate earthquakes in this region have been referred to as “small earthquake concentrating area in Puyang” .Four earthquakes of M L ≥ 3 have occurred in this area since the 2011 Fanxian earthquake (Oct .13 ,M L 4 .3) with a frequency of 1 ,thus indica‐ting a significant in decrease in seismicity in this area .Earthquakes of M L ≥ 2 have occurred more frequently since Nov .2013 ,including the two Fanxian earthquakes (Nov .20 ,2013 M L 3 and Aug .5 ,2014 M L 3 ) , thus indicating increased seismicity .These frequent small and moderate earthquakes provide primary information of regional tectonic stress field .In this study ,we evalu‐ated the stress field of this area from focal mechanism solutions obtained by applying Snoke's al‐gorithm to the data collected from the Seismic Network Centers of Shandong ,Hebei ,and Henan provinces .We can better understand the Liaokao fault zone by analyzing pre‐earthquake charac‐teristics ,such as spatio‐temporal variation of principal compressive stress axis (especially P axis) and the consistent parameters of focal mechanism solutions of moderate‐strong earthquakes ,as well as the background and the seismogenic structure of this region .These results are also valued as a good reference for earthquake risk estimation ,rapid earthquake damage assessment ,and de‐termination of correlation between characteristic variation of tectonic stress field and earthquakes in this area .The results show that the focal mechanisms are predominantly strike‐slip fault solu‐tions ,and tectonic stress features horizontal or near horizontal torsion .Further ,the azimuth of the P axis is related to seismic activity ,and the temporal variations of P axis can be used as a reference for predicting small and moderate earthquakes in this region .Pre‐earthquake spatio‐temporal variation is a complex process that varies between different regions ;therefore ,further research is required on more cases to obtain more effective solutions for earthquake disaster prevention .关键词
濮阳小震集中区/Pg 和 Sg 波的最大振幅比法/震源机制解/区域应力场Key words
small earthquake concentrating area in Puyang/maximum amplitude ratio of Pg and Sg/focal mechanism solution/regional stress field/correlation of P-axis azimuth variation and seismic activity分类
天文与地球科学引用本文复制引用
陈亚红,王鹏,张军,邵李娜,申茂正,董春勇..濮阳小震集中区震源机制解与应力场跟踪分析与研究[J].地震工程学报,2015,(z2):157-163,7.基金项目
山东省地震局重点科研基金项目 （）
