四川盆地内部少震与弱震区MS≥4.5地震预测意义分析

自2008年汶川MS8.0地震发生以来,四川盆地内部及盆地边缘发生了一系列MS≥4.5地震,部分地震发生之后,四川及邻区又发生了MS≥6.0强震。2019年6月17日四川长宁MS6.0地震后,对四川盆地内部及盆地边缘MS≥4.5地震的预测意义进行了研究和疏理。通过给定不同的预测规则,对上述MS≥4.5地震的预测效能进行了统计检验,结果表明:仅四川盆地内部,以三台、梓潼等区域为代表的历史少震与弱震区MS≥4.5地震对四川及邻区未来半年内发生MS≥6.5地震具有显著的预测意义。

Predictive Efficiency Tests of Moderate Earthquakes with Sizes MS≥4.5 in Low Seismicity Regions within Sichuan Basin

Since the 2008 Wenchuan MS8.0 earthquake,a series of moderate earthquakes with size MS≥4.5 occurred in the interior and the margin of Sichuan Basin.It has been observed that some MS≥6.0 strong earthquakes in Sichuan and its surroundings followed a part of the MS≥4.5 earthquakes in the interior and the margin of Sichuan Basin.After the Sichuan Changning MS6.0 earthquake on June 17,2019,the statistical significance of predictive efficiency for the moderate earthquakes in the interior and the margin of Sichuan Basin has been systematically investigated.Under different prediction rules,statistical tests for predictive efficiency of the MS≥4.5 earthquakes have been done,and the results indicate that only some MS≥4.5 events occurred in low seismicity regions,such as Santai,Zitong,have statistically significance of predictive efficiency,and can be a predictor for MS≥6.5 strong earthquakes within half a year in Sichuan and its adjacent areas.