选取中原地区(30°-38°N,109°-118°E)1970年1月至2018年10月ML ≥ 4.0地震,分析4级地震平静异常与异常结束后发生的MS ≥ 4.5地震的相关性,判定4.0级地震平静异常指标为90天,统计平静异常结束后1.5年内MS ≥ 4.5地震的发生概率,发现异常映震率为61.8%,计算得到地震预报效能评分R值=0.547,说明4级地震异常平静预测效能明显。分析认为,利用4.0级地震平静90天预测中原地区MS ≥ 4.5地震具有一定指示意义,结合该区地震平静时段进行分析,可明显减少地震虚报率。
The study on the quietness of earthquakes with ML ≥ 4.0 and MS ≥ 4.5 since 1970 in Central China shows that the anomaly index of the quietness of earthquakes with ML=4.0 is 90 days. After quiet anomalies of earthquakes with ML ≥ 4.0, it can be predicted that earthquakes with MS ≥ 4.5 may occur in the 1.5 year, with an anomalous reflecting rate of 61.8%. By calculating R value (0.547), it shows that the method has a certain predictive value and a confidence of at least 97.5%. If combined with the analysis of the quiet time of regional earthquakes, the false prediction rate can be obviously reduced. Therefore, the calm index has certain guiding significance in predicting earthquakes with MS ≥ 4.5 in Central China.
2019,40(4): 53-58 收稿日期:2018-12-25
DOI:10.3969/j.issn.1003-3246.2019.04.008
基金项目:2019年中国地震局震情跟踪定向工作任务(项目编号:2019010109)
作者简介:谢健健(1973-),女,高级工程师,主要从事地震活动性分析等研究工作。E-mail:jiankbeauty@163.com
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