2023年12月18日积石山M_(S)6.2地震前单台波速比变化特征  

Characteristics of wave velocity ratio at single seismic station before December 18,2023,Jishishan M_(S) 6.2 earthquake

作　　者：邢康 贾漯昭 刘晓锋 吴亚锋 孙宗强 XING Kang;JIA Luozhao;LIU Xiaofeng;WU Yafeng;SUN Zongqiang(Henan Earthquake Agency,Zhengzhou 450016,China;Bureau of Earthquake Prevention and Disaster Reduction of Shuifu County,Yunnan Province 657800,China)

机构地区：[1]河南省地震局,郑州450016 [2]水富市防震减灾局,云南657800

出　　处：《地震地磁观测与研究》2024年第5期28-33,共6页Seismological and Geomagnetic Observation and Research

摘　　要：收集整理甘肃及邻省地震台网2015年1月—2023年12月产出的震相观测报告,采用单台多震和达法,分析2023年12月18日积石山M_(S)6.2地震前震中附近地区单台波速比变化特征。结果表明:民和、兰州台波速比震前呈不同形态的低值异常,白银、渭源、合作和岷县台波速比震前变化基本平稳;与地处震中以北的民和、兰州和白银台相比,位于震中以南的渭源、合作和岷县台波速比均值明显偏高。综合分析认为,民和、兰州台波速比低值异常对判定此次积石山M_(S)6.2地震前震中以北和北东方向可能存在孕震体具有重要参考价值,此外震中附近单台波速比具有南高北低的分布特征。Based on the seismic phase observation reports produced by Gansu and its adjacent provincial networks from January 2015 to December 2023,this paper analyzes the variation of single-station wave velocity ratio in the vicinity of the epicenter before the Jishishan M_(S) 6.2 earthquake on December 18,2023,using the Wadati method of single-station and multi-earthquake.The results show that the wave velocity ratio of MIH and LZH stations exhibited different forms of low-value anomalies before the earthquake,while the wave velocity ratio of BYT,WYT,HZT,and MXT stations remained relatively stable before the earthquake.Compared with MIH,LZH,and BYT stations located north of the epicenter,WYT,HZT,and MXT stations located south of the epicenter have significantly higher average wave velocity ratios.Based on comprehensive analysis,we think that the low-value anomaly of wave velocity ratio at MIH and LZH stations has an important reference value for determining the possible existence of seismogenic bodies in the north and northeast directions before the Jishishan M_(S) 6.2 earthquake.In addition,the velocity ratio of a single station near the epicenter has a distribution characteristic of being higher in the south and lower in the north.

关 键 词：积石山M_(S)6.2地震 单台多震和达法 波速比 震前 变化特征 

分 类 号：P315.7[天文地球—地震学]