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.
出处
《华北地震科学》
2004年第2期40-44,共5页
North China Earthquake Sciences
关键词
重力异常
地震活动性
地震预报
anomaly of gravity
seismicity
earthquake prediction
