选取中原地区1970—2020年发生的983次ML≥3.0地震,按季度、半年和全年统计地震频次,回溯检验各时段ML≥3.0地震高频次异常与周边地区ML 4.5地震的对应关系,得到以下结果:按照季度、半年和全年统计,3级地震高频次异常定量指标分别为5次、9次和18次,高频异常后1年内发生ML≥4.5地震的概率分别为0.65、0.63和0.64,且R值计算结果表明,使用该方法预测地震具有一定可信度。将研究区以不同形式划分多种小区,进行3级地震高频次与ML≥4.5地震震中空间相关性研究,发现在19次震例中,18次震例均可预估ML≥4.5地震的发震区域,认为预测范围可由42平方度减小到21平方度,在少震弱震地区地震预测预报日常工作中,具有一定实用价值。
983 ML≥3.0 earthquakes that occurred in Central China from 1970 to 2020 were selected in the study. Statistics of earthquake frequencies by quarter year, half-year, and whole year are obtained to analyze the relations between the high-frequency anomalies of ML≥3.0 earthquakes in each period and the occurrence of ML 4.5 earthquakes in the surrounding areas. The following results are obtained. The indexes of high-frequency anomalies of ML 3.0 earthquakes are 5, 9 and 18 for the seasonal, semi-annual, and annual statistics, respectively. The probabilities of ML≥4.5 earthquakes within one year after high-frequency anomalies are 0.65, 0.63 and 0.64, respectively. The calculation results of the R-value show that this method has certain credibility in earthquake prediction. The research area is divided into several sub-areas in different forms and the spatial correlation between the high-frequency anomalies of ML 3.0 earthquakes and the epicenter of ML≥4.5 earthquakes is studied. The earthquake generating area of 18 ML≥4.5 earthquakes can be predicted among 19 research cases. It is considered that the prediction range can be reduced from 42 square degrees to 21 square degrees, which has certain practical value in the daily work of earthquake prediction in areas with few earthquakes and weak earthquakes.
2021,42(4): 36-44 收稿日期:2021-03-16
DOI:10.3969/j.issn.1003-3246.2021.04.005
基金项目:中国地震局地震科技星火计划(项目编号:XH20036)
作者简介:谢健健(1973-),女,高级工程师,主要从事地震活动性研究等工作。E-mail:jiankbeauty@163.com
*通讯作者:孙召华(1984-),女,硕士,工程师,主要从事地震监测与分析预报工作。E-mail:sunzhaohua-1029@163.com
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