CAJ | 학술논문

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29-81 km 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31-36 km，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34-49 km．总的看来，青藏高原地区地壳最厚，可达81 km；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．
이용중국수자지진태망30개태참적고질량관빈대원진수거，채용H-k 첩가수색법대중국경내적지각결구진행연구，획득료연구구내적지각후도화vP/vS 분포특정．결과표명，중국경내적vP/vS 치개우1．6-1．9지간，지각후도변화극렬，재29-81 km 지간．100°-110°E 지간존재일개지각후도두변대，장중국분위동서량개부분．동부지각후도상대균균，위31-36 km，서부지구지각후도상대교후차변화교대，중부지구지각후도위34-49 km．총적간래，청장고원지구지각최후，가체81 km；천산、준갈이분지화내몽고지구지각후도차지；화남지구지각최박．령외，중국대륙지각평균파속비위1．738（σ＝0．253），비전구대륙평균파속비1．78（σ＝0．269）저．교저적파속비가능암시중국경내지각저속층적존재혹자철미질성분적결실．
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.