文安5.1级地震前后不同时间尺度的重力变化分析*

(中国地震局第二监测中心,陕西 西安 710054)

文安5.1级地震; 流动重力观测; 重力变化; 重力场

Gravity Variation in Different Time Scales before and after the Wen'an MS5.1 Earthquake
LIANG Wei-feng,ZHU Yi-qing,XU Yun-ma,LIU Lian,GUO Shu-song,LIU fang

(Second Crust Monitoring and Application Center,CEA,Xi'an 710054,Shannxi,China)

Wen'an M5.1 earthquake; mobile gravity observation; gravity variation; gravity field

备注

系统深入地分析了2005~2009年华北地区流动重力观测资料,提取2006年河北省文安县MS5.1地震前后0.5 a、1 a等不同时间尺度可靠的重力场动态变化信息,研究其与地震活动的关系。结果 显示:文安地震孕育阶段,测区出现较大范围的区域性重力异常,并产生与地震孕育有关的局部重力异常区及重力变化高梯度带。重力场动态图像较清晰地反映了区域重力场的有序性演化与地震活动。

Analyzing the mobile gravity observational data in North China from 2005 and 2009 systematically and deeply,we derived dynamic variation of the regional gravity field in different time scales before and after Wen'an MS5.1 earthquake,and studied the relationship between gravity anomaly variation and seismic activity.The result showed that there existed regional gravity anomaly in a wide range in the survey area during the preparation of Wen'an MS5.1 earthquake,and there were local gravity anomaly area and high gradient zone of gravity variation referential to the earthquake preparation.The dynamic image of gravity field clearly reflected the evolution orderly and seismic activity of regional gravity field.