滦县M_L5.0地震前重力异常探讨  

RESEARCH ON GRAVITY ANOMALY BEFORE LUANXIAN M_L5.0 EARTHQUAKE

作　　者：刘善华[1] 张鹤[1] 李民[1] 

机构地区：[1]中国地震应急搜救中心,北京100039

出　　处：《大地测量与地球动力学》2005年第1期30-34,共5页Journal of Geodesy and Geodynamics

摘　　要：分析研究了2004年1月20日河北省滦县ML5.0地震孕育过程中首都圈重力场的异常变化和动态演化 特征。结果表明,震前出现的重力上升 下降 上升变化是较明显的中短期异常反映;重力场动态图像较清晰地反映 了研究区重力场的准均匀态 非均匀态 发震的演化过程;滦县地区重力场的异常变化形态支持了孕震体震前膨胀 的理论。In this paper, the abnormal variation and evolution characteristics of the gravity field in Beijing area in the seismogenic process of the Luanxian %M%-L5.0 earthquake on January 20,2004 are analyzed and studied. The results show that the ascent-descent-ascent variations of gravity before earthquake are the obvious reflection of medium-short-term anomaly.The dynamic patterns of gravity field reflect clearly the evolutionary process of gravity field: quasi-homogeneous state—non-homogeneous state—earthquake occurrence. The theory of seismogenic body impending before earthquake is supported by anomaly variation of gravity field in Luanxian area.

关 键 词：重力异常 重力场 地震孕育 孕震体 中短期异常 首都圈 动态演化 异常变化 动态图像 清晰 

分 类 号：P315[天文地球—地震学]