【摘要】 通过对1992~2008年间各期观测资料进行全时空扫描,分析华北地区网区重力场的演化特征,总结震前异常的形态、持续时间和变化幅度,指出重力场空间变化易于发生地震的部位,并对一些问题进行讨论。结果显示:华北地区重力场总体变化不具明确规律性;大量测点存在明显的背景性趋势性异常变化;重力场变化与网区及周边地区中强地震的活动联系密切,较明显的重力场异常反应多发生在震前2年左右时间,且常伴有大面积高值异常区出现。重力变化"0"线、高梯度带、异常中心(含极值)附近是重力场空间变化易于发震的部位。更多还原

【Abstract】 This paper analyze the characteristics of gravity variations in the observed area in North China using space-time scan method on basis of gravity data from 1992 to 2008.The shape,duration and magnitude of anomaly before earthquakes are summarized,and the earthquake prone region in the spatial variation of gravity field is presented.The results show that the variation of gravity field has no obvious regularity;a lot of sites show clear tendency anomaly;the variation of gravity field is correlative closely with the earthquakes in and around the net,and most of the anomalies occur 2 years before the earthquakes;0 gradient line,high gradient zone and extreme center of gravity field are the earthquake prone region.更多还原