四川九寨沟7.0级地震中长期预测的回顾认识

回顾了2013年郭增建提出的基于地震活动性的"静中动"和后期与作者共同发展的"准静中动"方法,以1987年1月8日在甘肃南部迭部县发生的5.9级地震作为标志性的"准静中动"地震,结合国家地震局在1989年综合划定的1990—2000年南北地震带10年地震危险区,用中长期预测的时间尺度,指出了南北地震带北段三个未来可能发生6~7级地震的地区,其中一个就是四川省九寨沟地区。回顾分析中对"静中动"方法预测效能、存在的问题及一些中长期预测的问题进行讨论,得到两点认识:一是通过这次地震的再次验证,证明"静中动"方法是一种可行的预测地震的独立指标方法,在验证的基础上对该方法进行了优化认识;二是基于"静中动"方法与南北地震带北段10年地震危险区对应地震较为准确的启发,初步认为前兆可以划分为平静期的前兆与活跃期的前兆,而前者可能对于地震的预测意义更大,未来可以沿这一思路开展进一步的论证和研究。

Review of Mid-long Term Prediction for Jiuzhaigou MS 7.0 Earthquake in Sichuan Province

In this study,the Diebu,Gansu M_S5.9 earthquake,which occurred on January 8,1987,was regarded as the symbolical earthquake based on the review of the "activity in quiescence" and "quasi-activity in quiescence" methods and the analysis of the 10-year seismic risk area in the North-South seismic belt designated by the State Seismological Bureau in 1989. Then three places in the northern section of the North-South seismic belt,where earthquakes with magnitudes in the range of 6~7 may occur,were identified using the time scale of mid-long term prediction,one of which is the Jiuzhaigou area in Sichuan Province. Based on the discussions of some problems in the mid-long term prediction,the following conclusions are derived:(1) The Jiuzhaigou M_S7.0 earthquake verifies that "activity in quiescence" is a feasible method to predict earthquakes,and the method has been optimized in this study. (2) Based on the "activity in quiescence" method and the analysis of the 10-year seismic risk area in the North-South seismic belt,the precursors can be distributed into quiet and active periods,and the precursors in the quiet period may be more significant in predicting earthquakes.