摘要
在综合分析1991年以来祁连地震区及周边7次M_(S)6.0以上地震前嘉峪关气氡异常特征的基础上,进一步分析嘉峪关气氡趋势异常与门源M_(S)6.9地震的关系。分析结果显示:(1)在该区域,有些地震发生前气氡出现了明显的响应,表现为破年变和短期成组突跳异常变化;有些地震发生前气氡无响应,且地震发生前气氡是否有响应与震中距没有明显的关系。(2)地震发生前气氡是否出现异常,与地震发生的断裂紧密相关,同一断裂的地震,气氡异常具有相似性特征。地震前分布在大柴旦—宗务隆山断裂上的气氡都出现了破年变和成组突跳的配套性异常,而分布在托莱山—冷龙岭断裂上的气氡通常没有异常显示。(3)嘉峪关气氡的趋势异常可能与整个区域构造活动的增强有关,它可能是玛多M_(S)7.4及其后发生在祁连山地震区及其周边包含门源M_(S)6.9在内一系列M_(S)5.5以上地震的响应。该研究对地震前兆异常性质的判定、地震跟踪监测和预测效能的提高具有重要意义。
Based on a comprehensive analysis of the characteristics of radon anomalies in Jiayuguan before seven M_(S)≥6.0 earthquakes in Qilian earthquake area and its surrounding areas since 1991,the relationship between the trend anomaly of gas radon in Jiayuguan and the Menyuan M_(S)6.9 earthquake was further analyzed.The results showed:(1)The concentration of gas radon appeared obvious response to some earthquakes and had no response to other earthquakes in the study area.There is no obvious relationship between the gas radon response and the epicenter distance.(2)Whether the gas radon is abnormal is closely related to the seismogenic fault of earthquake.The anomalies of gas radon have similar characteristics before earthquakes with the same seismogenic fault.The gas radon concentration appeared distortion anomalies in annual variation and sudden jump in short term before eathequakes distributed along the Dachaidan-Zongwushan fault and had no anomalies before eathequakes distributed along the Tuolaishan-Lenglongling fault.(3)The trend anomaly of gas radon in Jiayuguan may be related to the enhancement of tectonic activity in the study area,which may be the response of Maduo M_(S)7.4 and a series of M_(S)5.5 earthquakes occurred in the Qilian Mountains and its surrounding areas,including the Menyuan M_(S)6.9 earthquake.This study is of great significance to the judgment of earthquake precursory anomalies and the improvement of earthquake tracking monitoring and prediction efficiency.
作者
苏鹤军
周慧玲
李晨桦
马东正
SU Hejun;ZHOU Huiling;LI Chenhua;MA Dongzheng(Gansu Lanzhou Geophysics National Observation and Research Station, Lanzhou 730000, Gansu, China;Lanzhou Institute of Geotechnique and Earthquake, CEA, Lanzhou 730000, Gansu, China;Gansu Earthquake Agency, Lanzhou 730000, Gansu, China)
出处
《地震工程学报》
CSCD
北大核心
2022年第2期389-397,共9页
China Earthquake Engineering Journal
基金
甘肃省地震局地震科技野外站基金(2021Y11,2021Y16)
地震科技星火计划项目(XH21033)
甘肃省科技计划项目(20JR10RA500,21JR7RA796)
2021年度震情跟踪定向工作任务(2021010302)。
