中强地震平静是汶川8.0级地震前最显著的地震活动异常

本文对四川地区1923年以来5.0级以上地震资料进行了分析研究。 结果表明, 研究区中强地震经历了4个较为完整的周期活动, 中强地震具有16年的准周期活动特征, 平静期持续5年左右, 从2008年汶川8.0级地震开始, 研究区将进入第5个活动周期, 其可能的持续时间为2024年前后。 2008年汶川8.0级地震前, 5.0～5.9级、 6.0～6.9级、 7.0～8.0级三个档次的地震事件的平静间隔均达到统计时段的历史之最, 三个档次地震的平静均被汶川8.0级地震直接打破, 中强地震超长平静是汶川8.0级地震前最为显著的异常现象。

Moderate-to-strong Earthquake Quiescence is the Most Significant Seismic Anormaly before the Wenchuan 8.0 Earthquake

This paper analyzed M_S≥5.0 earthquakes since 1923 in the region of Sichuan. The result shows that strong earthquakes in the region experienced four complete cycle of seismic activities, and there is a 16-year quasi-periodic characteristics for medium to strong earthquake. The quiet period lasted about 5 years. Starting from the 2008 Wenchuan 8.0 earthquake, the study area will enter into the fifth active cycle and continue to about 2024. Quiescence intervals for M5.0～5.9, M6.0～6.9, and M7.0～8.0 events reached the historical highest before the May 12 , 2008 Wenchuan 8.0 earthquake. Long-term quiescence of strong earthquake is the most significant anomaly before the Wenchuan 8.0 earthquake.