青藏高原北缘地区上地幔P波速度结构

Upper Mantle P-Velocity Structure in the Northern Region of the Qinghai-Tibet Plateau

本文利用长周期P波波形资料,通过拟合理论地震图的方法研究了青藏高原北缘东侧区和西侧区的上地幔P波速度结构。结果表明,在这两个区域的上地幔结构中均存在P波低速层,且盖层的厚度较薄,在405km和670km深处均有P波速度的一级间断面。在670km深处这两个地区的速度结构仍有差异。

In this paper, long-period P-waveforms have been used to study the upper mantle P-velocity structure of east and west regions in the northern margin of the Qinghai-Tibet plateau by matching synthetic seismograms. The result shows that the present model consists of low velocity zones and thin lid of the upper mantle and at the depths of 405km and 670km there exist first-order discontinuities in these two regions. The lateral heterogeneity of velocity structure in these two regions may cover down to 670km.