冀鲁豫交界地区重力场变化与区内小震关系探讨  

Relationship between Gravity Field Change and Small Earthquakes in the Combined Areas of Hebei,Shandong,and Henan Provinces

作　　者：谢汝一[1] 刘越[1] 秦建增[1] 罗翔飞[1] 李青[1] 

机构地区：[1]中国地震局地球物理勘探中心,河南郑州450002

出　　处：《地震工程学报》2016年第4期581-587,共7页China Earthquake Engineering Journal

基　　金：行业专项(201508009;201208008)

摘　　要：冀鲁豫交界地区历史上曾发生过多次中强地震,是一直受关注的地震危险区。利用该区1995—2010年共20期的流动重力观测资料,在统一起算基准、消除系统误差的基础上进行拟稳平差,计算重力场累积变化量;通过对重力场变化的分析,研究测区内重力场动态变化与测区内发生的一系列4级左右地震的关系。研究结果认为:冀鲁豫地区发生M_L4.0以上地震前后震区的重力场变化具有明显的"震前持续上升-震后反向恢复"的特征。The juncture region of Hebei,Shandong,and Henan provinces（Ji-Lu-Yu region for short）,where many middle-strong earthquakes have occurred throughout history,is the focus of this study as an earthquake risk area.We used 20 stages of mobile gravity observation data,gathered from 1995 to 2010in the region,to calculate the accumulated variation in the gravity field by means of a quasi-stable adjustment,on the basis of a unified calculation datum and elimination of system error.By analyzing variations in the gravity field before and after five earthquakes,the relationship between the dynamic variation in the gravity field and a series of M_L4.0earthquakes was studied.The earthquakes studied were the M_L4.3earthquake,April 27,2005,epicenter located between Puyang in Henan and Juancheng in Shandong;the Puyang M_L4.6earthquake,April 9,2006;the M_L4.3earthquake,January 3,2008,located between Fengqiu and Lankao in Henan;the M_L4.8earthquake,March 10,2008,located between Fengqiu and Lankao in Henan;and the Puyang M_L4.2earthquake,January 15,2010,The results show that,in this region,the gravity field variation shows a certain regularity before and after earthquakes of magnitude4.0.This characteristic is obvious in that ＂gravity values rise continuously before earthquakes and reverse after＂.In addition,reasons for the regularity in the gravity field variation before and after earthquakes are investigated in this article.

关 键 词：冀鲁豫 重力观测 地震 重力场变化 

分 类 号：P315.72[天文地球—地震学]