云南地区强震前小震调制比特征分析

利用调制比时空扫描方法,对1973-2014年云南地区Ms≥6.0地震进行回溯性研究,分析强震前区域小震调制比时空演化过程.结果 显示,从小震调制比异常开始至发震的持续时间为1.5a之内,调制比异常的最高值需大于0.57,强震多发生在调制比为最高值时或其后14个月内异常区边界或内部调制比显著高值附近,震级随异常持续时间...

Analysis of characteristics of small earthquake modulation ratio before strong earthquakes in Yunnan region

Using the spatiotemporal scanning method of modulation ratio (R_m), a retrospectively study of M_S ≥ 6.0 earthquakes in the Yunnan region from 1973 to 2014 was carried out to analyze R_m spatiotemporal evolution of regional small earthquakes before strong earthquakes. The results show that the duration from the start of anomalies to earthquake occurrence is less than 1.5 years, the max R_m value should be greater than 0.57, strong earthquakes mostly occur at the time of the max R_m or within 14 months afterward and the epicenters are always located at the boundary of the anomaly area or near the significant-high R_m place in the anomaly area, there is a general increasing trend for magnitude with anomaly duration. Strong earthquakes usually occur in western Yunnan. In terms of regions, most strong earthquakes in southwest Yunnan occur within 6 months, especially 3 months, after the max R_m value (R_m ≥ 0.57) at the boundary of the anomaly area, and strong earthquakes in northwest Yunnan often occur within 7-12 months after the max R_m value (R_m ≥ 0.67) near significant-high R_m place in the anomaly area, strong earthquakes in northeast Yunnan mostly occur at the time of the max R_m value (R_m ≥ 0.67) in the anomaly area.