唐山北部地区浅层一维剪切波速度结构初步研究  

Preliminary Study on One-dimensional Shear Wave Velocity Structure of the Shallow Crust in Northern Tangshan Area

作　　者：王莉婵 毛国良[1] 蔡玲玲[1] 马旭东 王亚玲 王宁[1] Wang Lichan;Mao Guoliang;Cai Lingling;Ma Xudong;Wang Yaling;Wang Ning(Hebei Earthquake Agency,Shijiazhuang 050021,China)

机构地区：[1]河北省地震局,石家庄050021

出　　处：《震灾防御技术》2022年第1期104-113,共10页Technology for Earthquake Disaster Prevention

基　　金：中国地震局地震监测、预测、科研三结合课题(3JH-202001014)。

摘　　要：2019年8月2日河北省唐山市路南区某矿井区发生ML2.4巷道塌陷,基于塌陷周边台站观测到的短周期瑞雷波,提取面波基阶群速度频散曲线,并利用迭代反演方法得到研究区域地下10 km深度范围内的一维剪切波速度结构,用于精定位分析。速度分析结果表明,研究区域浅表剪切波速度约为2.46 km/s;深度为2 km时,塌陷周边存在小范围的低速区,速度约为2.57 km/s;深度约为4 km时,剪切波速度达3.47 km/s;深度为5~9 km时,唐山东部沉积盆地内存在1个剪切波低速层。精定位分析结果表明,增加浅层速度模型有助于提高深度较小的地震定位精度;塌陷周边的低速区向下延伸近20 km,为地震多发区。On August 2,2019,a ML2.4 mine laneway collapse occurred in the Lunan district of Tangshan,Hebei province.In this pa-per,we extracted the fundamental dispersion curve based on the short-period Rayleigh waves observed at the stations around the col-lapse,and then got the one-dimensional S-wave velocity structure within 10 km in the northern area of Tangshan by iterative inversion method,which can be used for precise location analysis.The result of the velocity analysis shows that the shallow S-wave velocity in the northern part of Tangshan is about 2.46 km/s;when the depth is 2 km,there is a small range of low-velocity area around the col-lapse,and the velocity is about 2.57 km/s;when the depth is 4 km,the shear wave velocity reaches 3.47 km/s;when the depth is 5-9km,there is a low velocity layer of S wave in the eastern Tangshan sedimentary basin.The result of precise location analysis shows that the addition of shallow velocity model is helpful to improve the accuracy of seismic location in shallow depth,and the earthquake prone area is the low-velocity area which arounds the collapse extending down nearly 20 km.

关 键 词：塌陷 面波频散 剪切波 速度结构 精定位 

分 类 号：P315.3[天文地球—地震学]