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

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

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，研究区将进人第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。

This paper analyzed Ms≥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 MT. 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.