利用接收函数研究程海断裂带莫霍面深度和地壳内S波速度结构特征  

Crustal Depth and S Wave Velocity Structure in Chenghai Fault Zone from Receiver Functions

作　　者：陈佳[1] 高琼[1] 王军[1] 邓嘉美[1] CHEN Jia;GAO Qiong;WANG Jun;DENG Jia-mei(Earthquake Administration of Yunnan Province,Yunnan Dalt 671000,China)

机构地区：[1]云南省地震局,云南大理671000

出　　处：《地震》2019年第1期72-80,共9页Earthquake

基　　金：云南省地震局陈颙院士工作站;云南省地震局青年基金和云南省地震局传帮带项目联合资助

摘　　要：利用程海断裂带附近27个数字地震台站远震波形资料,提取每一个台站的接收函数,计算出各台站莫霍面深度同时利用时间域线性反演方法,获得了各个台站下方的横波速度。结果显示:程海断裂带莫霍面深度从南部42km增至北部的54km,南部和北部莫霍面深度有明显的不同。从程海断裂带下方不同深度S波速度剖面可以看出,宾川及其北东部地区中下地壳存在明显的低速层,此低速层可能与还没有固结的热物质有关。而永胜南部地区,地壳中S波速度垂直变化剧烈,低速异常高速异常交替丛生,这可能是此区地震频发的主要原因。同时,本文对宽频带地震仪和短周期地震仪得到的接收函数进行了初步的对比分析。We used teleseismic records from the temporary and fixed stations near the Chenghai fault zone.The total of the stations is 27.We get the P-wave receiver functions of every station using the teleseismic waveform.We get the crust thickness and shear velocity using the time domain linear inversion method.The results show the depth of Chenghai fault belt change from 42 km in the south to 54 km in the north.The depth of Moho in the south is more different from the north.The Binchuan and its north eastern area show obvious low-velocity layer from the depth profile.The lower layer is related to the thermal material.Then in the south area of Yongsheng,the vertical change of S wave velocity is more drastical.Low speed and high speed layer exist alternately,which could be the reason why this area has many earthquakes.At the same time,we give the preliminary contrast analysis about the receive functions which were calculated using broad band and short-period seismographs.

关 键 词：程海断裂带 接收函数 横波速度 喜马拉雅台阵 宾川主动源台阵 

分 类 号：P315.7[天文地球—地震学]