华南上地幔P波速度结构

通过拟合15°-30°内的长周期P波走时及波形资料,得到了华南地区上地幔P波速度结构模型SC.研究结果表明,在华南地区的上地幔内无低速层存在,在405km和660km深度处仃一级间断面存在,速度跳跃分别为5.7％和4.6％.通过与欧洲西部上地幔模型K8,欧洲西北部上地幔模型S8和西藏地区上地幔模型QX8比较,我们发现各个构造区P波速度的过渡区是一致,但间断面的绝对深度不一样.

UPPER MANTLE P VELOCITY STRUCTURE OF SOUTHERN CHINA

The waveforms and travel times of long period P phase in the upper mantle range 15°-30° have been used to derive upper mantle P velocity structure SC of the Southern China. The model of upper mantle P velocity structure of Southern China shows that: there is not low velocity zone in the Southern China, there are first-order discontinuities at 405 km and 660 km. The jump of velocity is 5.1% at 405 km and 4.6% at 660km. A comparison of the upper mantle model of this study with the West Europe upper mantle model K8, Northwestern Eurasia upper mantle S8 and Tibet upper mantle model QX8 indicates that the shape of the P velocity profile of this study is similar to these tectonic regions through the transition region （300-700 km）, but there are differences in the absolute depths to the discontinuities.