地震学报（英文版）2003，Vol.16Issue(1)：26-33,8.
Lateral variation of Pn velocity beneath northeastern marginal region of Qinghai- Xizang plateau
Lateral variation of Pn velocity beneath northeastern marginal region of Qinghai- Xizang plateau
摘要
Abstract
Pn arrival time data are collected from the bulletins of both national and regional seismological network in China. These data are tomographically inverted to map the lateral variation and anisotropy of Pn velocity in the northeastern marginal region of Qinghai-Xizang plateau. The average Pn velocity in this region is 8.09 km/s, being a little higher than the average for whole China. Higher velocity is found in tectonically stable Qaidam basin, while lower velocity is seen in and around tectonically active Shanxi graben. The region where the 1920 Haiyuan great earthquake occurred shows a slightly low Pn velocity. A noticeable result is that, differing from the tectonically compressive Tianshan region, where Pn velocity is low, the Qilianshan region, where the Neotectonic deformation is also primarily compressive, shows high Pn velocity. In the uppermost mantle beneath the Ordos plateau Pn velocity is inhomogeneous, varying from higher velocity in southwestern part to lower one in northeastern part. This may be attributed to possible movement of the Ordos block, as there are strong earthquakes all around the block.关键词
Pn/tomography/northeastern Qinghai-Xizang plateauKey words
Pn/tomography/northeastern Qinghai-Xizang plateau分类
天文与地球科学引用本文复制引用
许忠淮,汪素云,裴顺平..Lateral variation of Pn velocity beneath northeastern marginal region of Qinghai- Xizang plateau[J].地震学报（英文版）,2003,16(1):26-33,8.基金项目
Foundation item: State Key Basic Research Project Development and Programming Mechanism and Prediction of Continental Strong Earthquakes (G19980407) and State National Science Foundation of China (49732090). （G19980407）
