秦岭-大别及邻区S波速度及其在秭归地震定位中的应用

摘要

在秦岭-大别造山带及邻区背景噪声相速度成像的基础上,用近邻算法反演得到深度6～38 km范围内的S波速度分布图像.依据S波速度结构建立湖北分区速度模型,并将该模型应用到2017-02-23秭归3.8级地震和06-16秭归4.3级地震定位中.结果显示,分区模型得到的总体平均误差比一维模型的更小,与三峡台网定位结果相比分区模型得到的定位结果偏差也更小.%Ambient noise tomography is a powerful method to image the structure of the crust and upper mantle with better resolution.We use the nearest neighbor algorithm to map S wave velocity based on the ambient noise phase speed tomography of the Qingling-Dabie orogenic belt.With depths of 6～38 km S wave velocity,we build the partition velocity model,and apply it to the seismic localization of the June 16,2017 Zigui M4.3 and the February 23,2017 Zigui M3.8 earthquakes.The results show that the average error of the partition model issmaller,and the seismic localization results of the partition model is closer to the results from the Three Gorges digital seismological network.So,the partition velocity model is more reasonable than the one-dimensional velocity model in seismic localization.