| 新疆及邻区Pn速度层析成像 |
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| 引用本文： | 裴顺平,许忠淮,汪素云,Thoma S M.Hearn.新疆及邻区Pn速度层析成像[J].地球物理学报,2002,45(2):218-225. |
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| 作者姓名： | 裴顺平 许忠淮 汪素云 Thoma S M.Hearn |
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| 作者单位： | 1. 中国地震局地球物理研究所,北京,100081;
2. Department of Physics, New Mexico State University, LasCruces, NM88003, USA |
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| 基金项目： | 国家重点基础研究发展规划项目 ( 95 -1 3-0 2 -0 5 )，中国地震局地球物理研究所论著 0 1AC1 0 1 4 . |
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| 摘 要： | 利用新疆及邻区2万多条Pn射线的走时资料,采用层析成像的方法反演该地区上地幔顶部的Pn速度结构.主要结果是:①新疆地区平均h速度为.2km/s,高于中国大陆地区的平均值(.0km/s),速度变化量从-0.3km/s到0.2km/s.②准噶尔盆地是明显的高Pn速度区,高速区与地貌形状吻合较好,最大值达.4km/s;塔里木盆地整体上呈现高速异常二者都可能与盆地是稳定地块、构造活动和变形较弱有关.③在盆地与山脉的交接带即主要的构造活动带,存在较低的Pn速度,可达7.9km/s.④塔里木南缘中部存在一显著的低速区,可能与岩浆活动和构造活动较强有关.⑤上地幔顶部波速各向异性整体上盆地中心较弱,边缘地带较强.新疆南部波速的各向异性可能是因印度板块对欧亚大陆的碰撞使地幔物质向北蠕动的结果.
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| 关 键 词： | 新疆 Pn速度 层析成像 |
| 文章编号： | 0001-5733(2002)02-0218-08 |
| 收稿时间： | 2001-02-19 |
Pn VELOCITY TOMOGRAPHY OF XINJIANG, CHINA AND ADJACENT REGION |
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| PEI SHUN-PING,XU ZHONG,HUAI\ WANG SU,YUN.Pn VELOCITY TOMOGRAPHY OF XINJIANG, CHINA AND ADJACENT REGION[J].Chinese Journal of Geophysics,2002,45(2):218-225. |
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| Authors: | PEI SHUN-PING XU ZHONG HUAI\ WANG SU YUN |
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| Institution: | 1. Institute of Geophysics, China Seismology Bureau, Beijing 100081, China;
2. Department of Physics, New Mexico State University, Las Cruces, NM88003, USA |
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| Abstract: | Travel times of more than 20,000 Pn arrivals recorded from Xinjiang and adjacent regional earthquakes are inverted in a tomographic study to map the lateral variations and anisotropy of Pn velocity of the uppermost mantle.The results indicate that (1) Average Pn velocity in Xinjiang region is 8.2 km/s, which is higher than the average 8.0 km/s for the mainland of China. The velocity varies from -0.3 km/s to 0.2km/s. (2) In Junggar basin, there is an obvious high velocity region, which is well consistent with topography and has the maximal velocity 8.4 km/s. On the whole, abnormal high Pn velocity also appears in Tarim basin. It is possibly because both basins are stable, and tectonic activity and deformation are weak there. (3) The low Pn velocity mainly exists in the transition region between basin and mountain, which is possibly attributed to strong tectonic activity. (4) A definite low Pn velocity region to the south of Tarim basin is possibly related to strong magma and tectonic activity. (5) Anisotropy of Pn velocity is generally weak in the central basin and strong on the edge of basin. Velocity anisotropy in the south of Xinjiang is possibly due to northward creep of mantle material caused by collision between India and Eurasia plate. |
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| Keywords: | Xinjiang Pn velocity Tomography |
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