2021年玛多M_(S)7.4和2022年门源M_(S)6.9地震引起的山东井水位同震响应特征分析

COSEISMIC RESPONSE ANALYSIS OF WELL WATER LEVEL IN SHANDONG PROVINCE CAUSED BY 2021 MADUO M_(S)7.4 AND 2022 MENYUAN M_(S)6.9 EARTHQUAKES

2021年5月22日青海玛多M S7.4地震和2022年1月8日青海门源M_(S)6.9地震引起栖霞鲁07井、枣庄鲁15井和菏泽鲁27井水位不同程度的同震响应。基于秒数据,对比分析3口井水位同震变化形态、幅度与分钟值记录的差异,并从含水层渗透性变化、地震能量密度等方面进行同震响应机理探讨。结果表明,井水位秒数据能够更加完整地记录水震波信息,更加精确展现水位同震变化形态、幅度;井水位对于远场大震的震荡形态主要受含水层水文地质条件的影响。在正常应力背景下,远场大震引起枣庄鲁15井水位同震响应的地震能量密度阈值大约是1.54×10^(-4)J·m^(-3)。

Coseismic responses of Qixia No.07 well,Zaozhuang No.15 well and Heze No.27 well caused by the May 22,2021 Qinghai Maduo M_(S)7.4 earthquake and the January 8,2022 Qinghai Menyuan M_(S)6.9 earthquake.Based on the second data,this paper analyzes the differences of water level coseismic change in the form and amplitude compared to the minute data,and discusses coseismic response mechanism from the aspects of aquifer permeability change and seismic energy density.The results show that the well water level second data can record the water shock wave information more completely,and show the shape and amplitude of the coseismic change of the water level more accurately;Coseismic variation range of well water level for far-field large earthquakes is mainly affected by the hydrogeological conditions of the aquifer;The oscillation pattern of the well water level to the far-field earthquake is mainly affected by the hydrogeological conditions of the aquifer.Under the normal stress background,the seismic energy density threshold of the water level coseismic response of Zaozhuang No.15 well caused by the far-field earthquake is approximately 1.54×10^(-4)J·m^(-3).