几种测震学指标的短临前兆异常的初步探讨

本文在国家地震局组织的实用化攻关研究的基础上,按日常预报实践中积累的经验,分析研究了江苏及邻近地区几次地震前缺震曲线、波速比变化、b值时间扫描、累计无震单元数、尾波参数特征和地震活动性时间分维6个指标的短临异常信息,得到以下初步结论:(1)一些测震学指标在中强震发生之前三个月左右出现前兆变化;(2)短临前兆异常的幅度与震级大小的关系不明显;(3)在预测检验过程中,对于多数指标R约为0.5—0.6左右。

THE PRIMARY RESEARCH FOR SHORT-TEMPORARY ANOMALIES USING SEISMOLOGICAL METHODS

Based on the practical research to tackle key problems, which were organized by the SSB, and according to the prediction experiences that are accumulated over a long-period, the short-temporary anomalies are discussed this paper. There are six indices used:the shock event lack curve, the wave velocity ratio variation, the b value time sweeping, the accumulated no-seismic unit numbers, the parameters of coda and the time fractal dimension of seismic frequency hierarchy.The simple conclusions are:(1) The anomalies for the most indices appear about 3 months before main shock.(2) It is not interrelated between the size of anomaly and the magnitude of the coming strong earthquake.(3) For the most indices the Xu''s mark is about 0.5-0.6 in the prediction check.