摘要
2021年5月22日青海果洛州玛多县发生Ms7.4地震,打破了青海地区长时间的6级平静,通过地球物理场定点形变观测资料分析,并结合地下流体资料异常变化研究玛多Ms7.4地震前青海地区应力场变化特征,认为2015年8月至2017年12月德令哈和玉树钻孔应变先后出现最大主应变减弱和增大减缓异常变化,玛多Ms7.4地震发生在玉树钻孔应变最大主应变方向指示方向。随着孕震过程的演化,震中附近的区域应力加载进一步增强,前兆异常演化具有向震中迁移的特征。
On May 22,2021,a Ms7.4 earthquake occurred in Maduo County, which is breaking the calm of a long-term earthquake of magnitude 6 or above in Qinghai. By analyzing the variation characteristics of stress field in Qinghai before the Ms7.4 Madduo earthquake through borehole strain observation data and abnormal variation characteristics of geophysical field data, it is found that: From August 2015 to December 2017,the maximum principal strain of Delingha drilling hole and Yushu drilling hole showed abnormal changes of weakening and mitigating successively.The Ms7.4 Maduo earthquake occurred in the direction indicated by the maximum principal strain direction of Yushu drilling hole. With the evolution of seismogenic process, the regional stress loading near the earthquake epicenter was further strengthened. The evolution of precursor anomaly is characterized by migration to the epicenter.
作者
苏维刚
马震
冯丽丽
孙玺皓
SU Weigang;MA Zhen;FENG Lili;SUN Xihao(Geodynamics Field Observation and Research Station of Qinghai-Tibet Plateau,Golmud 810001,China;Qinghai Earthquake Agency,Xining 810001,China)
出处
《高原地震》
2021年第4期7-12,共6页
Plateau Earthquake Research
基金
青海格尔木青藏高原内部地球动力学野外科学观测研究站专项课题资助。
