【摘要】 利用调制比时空扫描方法,对1973—2014年云南地区M_S≥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1.5 a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的延长大致呈增加的趋势;小滇西—滇西北地区的强震多发生在调制期内;从分区来看,滇西南强震多发生在调制比为最高值(R_m≥0.57)后6个月内的异常边界处,尤其是3个月内,滇西北强震多发生在最高值(R_m≥0.67)后7—12月内异常区内显著高值附近,滇东北强震多发生在最高值(R_m≥0.67)时的异常区内。更多还原

【Abstract】 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.更多还原