太原M_L5.0级地震前后的重力场变化  

Variations of gravity field before and after Taiyuan M_L5.0 earthquake

作　　者：秦建增[1] 李清林[1] 冯建林[1] 张晓普[1] 张瑞敏[1] 黄邦武[1] 张建志[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：《华北地震科学》2004年第2期40-44,共5页North China Earthquake Sciences

摘　　要：讨论了2002年9月3日太原ML5.0级地震前后重力场的变化。震前2001年12月～2002年6月重力场表现为:上升—下降—上升及平静—活动—平静的活动方式。部分测点点值、测段段差值的趋势性异常在持续相当长时间后,于2002年3月发生转折,6月表现为变化加速,点值和段差值的变化幅值在(30～60)×10-8m·s-2之间,地震发生在加速变化过程中。震后该区的重力异常逐渐恢复。重力变化可能是由该区地壳形变、地壳深部质量迁移和断层蠕动共同作用引起的。The gravity field in Shanxi surveying region changed obviously before and after Taiyuan M_L5.0 Earthquake occurred on Sep. 3, 2002. Before this event, from Dec. of 2001 to Jun. of 2002, the gravity field showed an pattern: ascent-descent-ascent and quiet-active-quiet. After the tendency anomaly lasted a period of time, the observing value on some sites turned in March, 2002, and accelerated in June. The variation of site value and segment difference was between 30×10^(-8)m·s^(-2) to 60×10^(-8)m·s^(-2), and the earthquake occurred in the period of acceleration. After the earthquake, the gravity anomalies recovered gradually. The Variation of gravity field in this area may be caused by the crustal deformation or deep transference and fault creep.

关 键 词：重力异常 地震活动性 地震预报 

分 类 号：P315.72[天文地球—地震学]