广西北流-广东化州交界5.2级地震前RTL异常特征

RTL Anomaly Characteristics before the M_(S)5.2 Guangxi Beiliu-Guangdong Huazhou Boundary Earthquake

采用“区域—时间—长度算法”(简称RTL算法)对2019年10月12日发生在广西北流-广东化州交界的5.2级地震进行了回顾性检验。选取2015年10月11日至2019年10月10日中国地震台网测定的M_(L)2.0以上地震目录,根据震中附近所在区域确定选取范围:109.0°~112.0°E,20.5°~23.5°N,并以0.5°为步长,在此区间内得到49个点,分别计算各点RTL值。分析结果显示:震前震中及其南北两侧共有8个点存在RTL异常,RTL分析方法可以作为本次地震前的一项异常指标。

The regional time-length algorithm(RTL)was used to retrospectively examine the M_(s)5.2 earthquake at the boundary between Guangxi Beiliu and Guangdong Huazhou on October 12,2019.The catalogue of earthquakes above M_(L)2.0 measured by China Earthquake Networks from October 11,2015 to October 10,2019 was selected,and the selection scope was determined according to the region near the epicenter:49 points were obtained in the range of 109.0°~112.0°E and 20.5°~23.5°N with step size of 0.5°.RTL values of each point were calculated.The analysis results show that there are 8 RTL anomalies at the epicenter and its north and south sides before the earthquake,and the RTL analysis method can be used as an anomaly index before the earthquake.