晋冀蒙交界地区余震短期发生率的预测效能评估和预测策略研究

发布时间：2018-10-22 07:07

【摘要】：为系统地考察晋冀蒙交界地区余震短期发生率预测的效能,以及构建适合区域地震活动特点的地震预测策略和预测指标体系,本文利用当前较为前沿的ETAS模型和"瘦化算法",采用连续滑动预测和N-test检验方法系统评估预测效能的方式,对晋冀蒙交界地区1980年以来的8个地震序列进行了回溯性研究.研究结果表明:ETAS模型和"瘦化算法"对该地区的余震发生率具有一定预测能力,预测"过少"的比例较低,但预测"过多"的比例较高;在主震发生后的早期阶段预测效果较好,但预测效能随着序列的持续时间显著下降;适度增加预测时间窗长可改善预测"过少"的情况,但对预测"过多"的情况改善不明显.此外,高阶余震激发能力偏弱,可能是晋冀蒙交界地区ETAS模型和"瘦化算法"预测效能偏低的原因之一.作为余震短期发生率预测的可能策略,建议在该地区的ETAS模型和"瘦化算法"预测应用中,采用3天的预测时间窗、仅对序列早期阶段进行应用,且重点关注"不低于"相应预测地震数目的底线思维,可能更具有现实意义.
[Abstract]:In order to systematically investigate the effectiveness of short-term aftershock incidence prediction in the Shanxi, Hebei and Mongolian border areas, and to construct the earthquake prediction strategy and prediction index system suitable for the characteristics of regional seismicity. In this paper, by using the ETAS model and the "thinning algorithm", and using the method of continuous sliding prediction and N-test to evaluate the prediction efficiency systematically, the paper makes a retrospective study of 8 earthquake sequences in the Shanxi, Hebei and Mongolian border area since 1980. The results show that ETAS model and "thinning algorithm" can predict the incidence of aftershock in this area, and the proportion of "too little" is lower, but the proportion of "too much" is higher. In the early stage after the occurrence of the main shock, the effect of prediction is better, but the prediction efficiency decreases significantly with the duration of the sequence, and the situation of "too little" prediction can be improved by the moderate increase of the prediction time window, but the improvement of the situation of "too much" is not obvious. In addition, the weak excitation ability of higher-order aftershocks may be one of the reasons for the low prediction efficiency of the ETAS model and the "thinning algorithm". As a possible strategy for short-term aftershock occurrence prediction, it is suggested that in the application of ETAS model and "thinning algorithm" in this area, a 3-day prediction time window should be used only for the early stage of the sequence. It may be more practical to focus on the bottom line thinking of "no less than" to predict the number of earthquakes.
【作者单位】：中国地震局地球物理研究所;
【基金】：中国地震局地球物理研究所基本科研业务费专项(DQJB13B19) 中国科学院国际合作局对外合作重点项目“‘一带一路’自然灾害风险与综合减灾国际研究计划”联合资助
【分类号】：P315

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