甘肃东南部地壳速度结构的区域地震波形反演

doi:10.6038/j.issn.0001-5733.2012.04.015

CORC > 北京大学 > 地球与空间科学学院

	甘肃东南部地壳速度结构的区域地震波形反演; Crustal structure in southeastern Gansu from regional seismic waveform inversion
	李少华 ; 王彦宾 ; 梁子斌 ; 何少林 ; 曾文浩
刊名	地球物理学报
	2012
关键词	波形反演地壳结构区域地震甘肃东南部 Waveform inversion Crust structure Regional earthquake Southeastern Gansu
DOI	10.6038/j.issn.0001-5733.2012.04.015
英文摘要	利用2007年完成扩建的甘肃东南部及邻近地区的24个宽频带固定地震台站记录到的2008年8月1日汶川地震余震的三分量地震全波形资料,采用小生境遗传算法和反射率法结合的波形反演方法,给出了甘肃东南部两个分区的地壳速度模型.西区和东区分别对应青藏高原块体和它与鄂尔多斯块体之间的过渡带,反演给出的平均模型显示,两个区上、中地壳的平均P波速度非常接近,由酸性岩和中性岩组成,下地壳P波速度差别较大,东区为6.41km/s,西区为6.96km/s,厚度相差也较大,东区为9.3km,西区为19.8km,地壳厚度由西向东减小,分别为54.6km和47.9km.显示西区下地壳由基性岩组成,而东区下地壳由中性岩组...; We applied three-component full-waveform inversion combining niching genetic algorithm and reflectivity method to the southeastern Gansu and obtained average crustal structure for two regions. The western and eastern regions are located at the northeastern margin of Qinghai-Tibet plateau and its transition zone to the Ordos block. The waveform data was recorded by 24 broadband permanent seismic stations implemented in 2007 from an aftershock of Wenchuan earthquake occurred on August 1, 2008. The final average models show that the western and eastern region has similar P-wave velocity in the upper and lower crust, which are composed of felsic and intermediate materials. The P-wave velocity is 6.96 and 6.41 km/s, and the thickness is 19.8 and 9.3 km at the lower crust for the western and eastern region, respectively. The total crustal thickness is 54.6 and 47.9 km for the western and eastern region. These results imply that the lower crust is composed of mafic in the western region and intermediate material in the eastern region, and support that the crust thickening in the Qinghai-Tibet block in the study region mainly occurred in the lower crust. The P-wave velocity for the upper mantle is 7.73 km/s at the western and 8.05 km/s at the eastern region, which corresponds to the young active tectonic region and old stable block, respectively. A sedimentary layer of 6.5 km thick is found at the eastern region with P-wave velocity of 5.78 km/s, but it is absent at the western region. Comparing with the global average crustal P-wave velocities given by PREM model, the crust in this region shows lower P-wave velocity values.; http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000303362400015&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701 ; SCI(E); 中文核心期刊要目总览(PKU); 中国科技核心期刊(ISTIC); 中国科学引文数据库(CSCD); 5; 04; 1186-1197; 55
语种	中文
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/85278]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	李少华,王彦宾,梁子斌,等. 甘肃东南部地壳速度结构的区域地震波形反演, Crustal structure in southeastern Gansu from regional seismic waveform inversion[J]. 地球物理学报,2012.
APA	李少华,王彦宾,梁子斌,何少林,&曾文浩.(2012).甘肃东南部地壳速度结构的区域地震波形反演.地球物理学报.
MLA	李少华,et al."甘肃东南部地壳速度结构的区域地震波形反演".地球物理学报 (2012).