2022年5月2日青州M_(L)4.1地震前昌邑青山深井综合观测仪数据异常分析

Analysis of abnormal changes of deep-well comprehensive observation instrument for Qingshan in Changyi,Shandong

2022年5月2日山东青州发生M_(L)4.1地震,潍坊地震监测中心站昌邑青山深井综合观测仪钻孔分量应变、垂直摆、孔隙压力和静水位观测,于2022年4月25日均出现趋势异常变化。为明确异常性质,山东省地震局对该仪器工作状态及周边环境开展多次现场核实工作,通过对历史观测资料、周边区域观测资料、历史地震数据以及模拟抽水干扰影响的分析,认为昌邑青山深井综合观测仪出现的同步趋势变化非地震前兆异常,受干旱及农田灌溉水井抽水的影响可能性较大。

On May 2,2022,an earthquake with a local magnitude(M_(L))of 4.1 occurred in Qingzhou,Shandong Province.Before the earthquake,on April 25,2022,the deep-well comprehensive observation instrument of Qingshan in Weifang Central Station showed abnormal trend variations in several observation items,including borehole component strain,vertical pendulum,pore pressure,and hydrostatic level.In order to clarify the properties of abnormal variations,Weifang Earthquake Monitoring Center Station has carried out several on-site verifications of the working state of the instrument,as well as the surrounding environment.Comprehensive analysis has been performed by analyzing the historical observation data,observation data of surrounding areas,historical earthquake data,and simulating the effects of pumping disturbance.It is considered that the synchronous trend variation of the Changyi Qingshan deep-well comprehensive observation instrument is more likely to be affected by pumping and drought during irrigation,and this abnormal change is not a precursor anomaly of the earthquake.