气候变化领域集成服务门户(CCPortal): Upper mantle seismic velocities and anisotropy in China determined through Pn and Sn tomography

CCPortal

DOI	10.1029/2006JB004409
	Upper mantle seismic velocities and anisotropy in China determined through Pn and Sn tomography
	Pei, Shunping; Zhao, Junmeng; Sun, Youshun; Xu, Zhonghuai; Wang, Suyun; Liu, Hongbing; Rowe, Charlotte A.; Toksoez, M. Nafi; Gao, Xing
发表日期	2007
ISSN	2169-9313
EISSN	2169-9356
卷号	112 期号:B5
英文摘要	[1] We have obtained velocity images of the uppermost mantle beneath China by performing tomographic inversion of both Pn and Sn traveltimes. From the Annual Bulletin of Chinese Earthquakes, 99,139 Pn arrivals and 43,646 Sn arrivals were selected. Pn anisotropy was also obtained simultaneously with Pn velocity. Average Pn and Sn velocities are 8.05 and 4.55 km/s, respectively, and maximum velocity perturbations are about 3 - 4%. The Pn and Sn velocities are low in eastern China and high in western China. Particularly high velocities are associated with old basins ( for example, Tarim, Junggar, Turpan-Hami, Qaidam, and Sichuan) and stable craton ( for example, Ordos). Low Sn velocities are found mainly throughout North China. In addition, velocities are relatively low beneath the central Tibetan Plateau and the North-South Seismic Zone ( along 103 degrees E). In Tarim and central China where we observe strong anisotropy, the fast Pn velocity directions are consistent with the directions of maximum principal compressive stress as well as directions of crustal movement determined from Global Positioning System. Beneath the India-Eurasia collision zone, the Pn anisotropy direction is parallel to the collision arc and nearly perpendicular to both the direction of maximum compression and crustal movement resulting from pure shear deformation. Both the velocity variations and anisotropy indicate that the Tibetan Plateau was extruded, and the mantle material beneath the plateau has flowed around the East Himalaya Syntax, while the remaining material has diverted northwestward beneath the Tarim Basin.
关键词	TIBETAN PLATEAU SOUTHWESTERN CHINA BENEATH CHINA CRUST COLLISION WESTERN DEFORMATION ZONE FLOW ASIA
语种	英语
WOS研究方向	Geochemistry & Geophysics
WOS类目	Geochemistry & Geophysics
WOS记录号	WOS:000246849700002
来源期刊	JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/257517
推荐引用方式 GB/T 7714	Pei, Shunping,Zhao, Junmeng,Sun, Youshun,et al. Upper mantle seismic velocities and anisotropy in China determined through Pn and Sn tomography[J]. 中国科学院青藏高原研究所,2007,112(B5).
APA	Pei, Shunping.,Zhao, Junmeng.,Sun, Youshun.,Xu, Zhonghuai.,Wang, Suyun.,...&Gao, Xing.(2007).Upper mantle seismic velocities and anisotropy in China determined through Pn and Sn tomography.JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,112(B5).
MLA	Pei, Shunping,et al."Upper mantle seismic velocities and anisotropy in China determined through Pn and Sn tomography".JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH 112.B5(2007).