定义了描述地震前重力变化异常时变距和量级的参数S和G。根据收集到的89个4.0级以上地震震例，统计分析了震前重力变化异常范围和量级与震级的关系，得到了流动重力地震分析预报的量化参考指标。结果表明：5、6、7、8级地震震级判定的重力变化异常量级参考指标分别为50、70、90、120μGal，重力变化异常范围参考指标分别为140、220、350、660km。此外，由于流动重力观测周期等方面的局限性，根据流动重力观测资料尚难以获得震级与重力变化异常时间过程的关系。

In this paper,the scale parameter S and magnitude parameter G are defined to describe gravity changes before earthquakes. 89 earthquakes with M_S ≥ 4.0 are collected to analysis the relationship between earthquake magnitude and S,G. The reference quantitative indexes for earthquake prediction are constructed. The results show that in the work of earthquake prediction,for an earthquake with potential magnitude of M_S5.0,M_S6.0,M_S7.0, or M_S8.0,the index G will be 50μGal,70μGal,90μGal,or 120μGal respectively,and the region of gravity change should be 140km,220km,350km,or 660km respectively. In addition,due to the limits on measurement interval,it is difficult to analyze the relationship between earthquake magnitude and time process of gravity changes.

P315

地震科技星火计划攻关项目（XH20039）、国家自然科学基金面上项目（41974021）共同资助