摘要
为定量分析2022年10月3日平山M_(S)4.3地震前地震活动变化,改进了“区域-时间-尺度”(RTL)算法,提高了与节点距离和时间较近的地震事件的权重,降低了距离和时间较远的地震事件的权重;采用改进的RTL算法分别扫描震中V_(RTL)值时间曲线和区域V_(RTL)值演化图像,结果显示:平山M_(S)4.3地震前震中西部和西南方向地震活动存在平静异常,同时发现2020年2月23日河北平山M_(L)3.5地震前震中南部存在地震平静异常;特征距离和震级下限对V_(RTL)值扫描结果有一定的影响,在地震活动复杂地区,特征距离对扫描结果的影响更大。该RTL算法可定量分析地震活动变化情况,为弱震区震情跟踪和地震危险性分析工作提供方法和依据。
The Pingshan M_(S)4.3 earthquake occurred in a weak earthquake area on October 3,2022.It is the largest earthquake within 50 km of the periphery since 1970.In order to quantitatively analyze the variation of seismic activity before the Pingshan M_(S)4.3 earthquake,We improved the“Region-Time-Length”(RTL)algorithm,increased the weight of the seismic events close to the node in distance and time,and decreased the weight of seismic events that are VRTLfar away from the node in distance and time.We used the improved RTL algorithm to scan the time curve of the VRTLepicenter and the evolution image of regional value,respectively.The results show that there are seismic quiescence anomalies in the west and southwest of the epicenter before the Pingshan M_(S) 4.3 earthquake.At the same time,there are seismic quiescence anomalies in the south of the epicenter before the Pingshan M_(L)3.5 earthquake on February 23,2020.The characteristic distance and the lower limit of magnitude have a certain influence on the scanning results,and the characteristic distance has a greater influence on the scanning results in the area with complex seismic activity.The RTL algorithm can quantitatively analyze the variation of seismic activity and provide methods and basis for the tracking of seismic situation and seismic risk analysis in weak earthquake areas.
作者
陈婷
孙丽娜
王晓山
张新东
CHEN Ting;SUN Lina;WANG Xiaoshan;Zhang Xindong(Hebei Hongshan National Observatory on Thick Sediments and Seismic Hazards,Xingtai 054000,China;Hebei Earthquake Agency,Shijiazhuang 050021,China)
出处
《华北地震科学》
2023年第3期60-66,共7页
North China Earthquake Sciences
基金
河北省地震科技星火计划项目(DZ20200827054)
河北省省级科技计划(22375406D)。
