用接收函数方法研究中国境内地壳结构  

Crustal structure in China from teleseismic receiver function

作　　者：张攀[1] 朱良保[1,2] 陈浩朋[1] 王清东[1] 杨颖航 

机构地区：[1]武汉大学测绘学院,中国武汉430079 [2]武汉大学地球空间环境与大地测量教育部重点实验室,中国武汉430079

出　　处：《地震学报》2014年第5期850-861,981,共12页Acta Seismologica Sinica

基　　金：国家自然科学基金(41374053);国家测绘地理信息局测绘基础研究基金(11-02-01;12-02-06)共同资助

摘　　要：利用中国数字地震台网30个台站的高质量宽频带远震数据,采用H-k叠加搜索法对中国境内的地壳结构进行研究,获得了研究区内的地壳厚度和vP/vS分布特征.结果表明,中国境内的vP/vS值介于1.6—1.9之间,地壳厚度变化剧烈,在29—81km之间.100°—110°E之间存在一个地壳厚度陡变带,将中国分为东西两个部分.东部地壳厚度相对均匀,为31—36km,西部地区地壳厚度相对较厚且变化较大,中部地区地壳厚度为34—49km.总的看来,青藏高原地区地壳最厚,可达81km;天山、准噶尔盆地和内蒙古地区地壳厚度次之;华南地区地壳最薄.另外,中国大陆地壳平均波速比为1.738(σ=0.253),比全球大陆平均波速比1.78(σ=0.269)低.较低的波速比可能暗示中国境内地壳低速层的存在或者铁镁质成分的缺失.This paper selects broadband teleseismic waveform data recorded by the China Digital Seismography Network to study the crustal structure in China.The crustal thickness and vP/vS ratio are estimated by the grid-search method.The result shows that the vP/vS ratio is between 1 .6 and 1 .9 ,and the crustal thickness ranges 29-81 km in China.The gradient belt between 100°E and 110°E divided China into eastern and western parts.The crustal thickness beneath eastern China smoothly ranges from 31 km to 36 km,while the crustal thickness in the western part is relatively thick and changed greatly.Crustal thickness ranges from 34 km to 49 km in the middle of China.In general,the crust in Tibetan Plateau is the thickest,reaching 81 km;crustal thickness de-creases in Tianshan,Junggar basin and Inner Mongolia and thins out in South China coastal.The average vP/vS ratio over China crust is about 1 .738 （σ=0.253）,which is significantly lower than the average 1.78 （σ= 0.269）of global continental crust.The lower vP/vS ratio may imply the existence of low velocity zone in the crust or the absence of mafic in China.

关 键 词：接收函数 H-k叠加搜索法 地壳厚度 波速比 泊松比 

分 类 号：P315.31[天文地球—地震学]