张北6.2级地震前的地壳形变特征

THE CHARACTERISTICS OF CRUSTAL DEFORMATION BEFORE THE ZHANGBEI EARTHQUAKE WITH M S 6.2

介绍了 １９９８ 年 １ 月 １０ 日张北 ６．２ 级地震前华北地区，主要是首都圈地区的地壳形变特征。分析了 Ｇ Ｐ Ｓ结果、跨断层形变观测以及定点台站观测的异常信息。认为张北地震前的地壳形变异常大部分是“场兆”异常；张北震中区在震前至少半年是处于形变闭锁阶段；地壳形变的前兆发展在总体上存在由东南向西北迁移特征。

The characteristics of crustal deformation in North China region, especially in Beijing area, before Zhangbei earthquake occurred on January 10, 1998, are introduced. The anomalies of GPS data, mobile survey across faults and seismological station data are analysed. It is thought that most crustal deformation anomalies before Zhangbei earthquake are “field precursors”, earthquake source area is locked at least half a year before the earthquake, and the crustal deformation precursors are characteristic of migrating from the Southeast to Northwest.