SEISMIC TOMOGRAPHY OF THE CHINESE CONTINENT AND ADJACENT REGION
SEISMIC TOMOGRAPHY OF THE CHINESE CONTINENT AND ADJACENT REGION
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发表时间：
1989
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通讯作者：
F. Liu;K. Qu
中科院分区：
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作者：
F. Liu;K. Qu
本文利用中国地震台网和ISC记录的区域和远端地震的纵波走时残差，重建了中国大陆及其邻近地区的三维速度图像。主要研究结果如下：1。速度图像清楚地显示了中国大陆及其邻近地区地壳和上地幔的横向非均质性，这种非均质性至少持续到1100 km深。上地幔速度图像与已知地表地质特征之间的相关性可以追溯到110km深度。在220公里以下，这种相关性几乎不可见。45-0km深度和45+0km深度的速度图像清楚地显示，中国大陆的地壳大致被经度102.5°E一分为二。110 km深度的速度图像显示速度异常呈块状。与中国大地构造图对比发现，扬子台地和塔里木台地对应于高速带，中朝台地多表现为低速异常，华南褶皱系为低速带。220 km深度的速度图像显示，中国许多地区都存在软流圈的低速带。se的大陆。与45-0km和45+0km的速度图像相似，400 km和600 km的图像也表明，在102.5°E附近，一条约200 km宽的带将中国大陆分为两个构造不同的部分。这意味着中国大陆的东西构造差异可能存在于整个上地幔中。
In this paper,the three-dimensional velocity images beneath the Chinese continent and adjacent regions are reconstructed using P-wave travel time residuals of regional and distant earthquakes recorded by the Chinese seismic networks and ISC.The main results are as follows:1.The velocity images display clearly the lateral heterogeneity of the crust and upper mantle beneath the Chinese continent and adjacent regions, which persists down to at least 1100 km deep.The correlation between the velocity image of the upper mantle and the known surface geological feature can be traced down to a depth of 110km.Below 220 km this correlation is hardly seen.2.The velocity images at depths of 45-0km and 45+0km show clearly that the crust of the Chinese continent is divided into two parts approximately by the 102.5°E longitude.3.The velocity image at a depth of 110 km shows that velocity anomalies appear in block patterns.Comparing the image to the tectonic map of China,we find that the Yangtze para-platform and the Tarim platform correspond to high velocity zones,the Sino-Korean paraplat-form appears mostly as a low velocity anomaly,the South China fold system is a low velocity zone.Note that a dumbbell-shaped east-west trending high-velocity zone exists along the Himalayas at the southern margin of the Tibetan block.4.The velocity image at a depth of 220 km shows that low-velocity zones of the asthenos-phere exist under many areas in the Chine.se continent.Similar to the velocity images of 45-0km and 45+0km,the images of 400 km and 600 km also indicate that a strip of about 200 km wide near 102.5°E divides the Chinese continent into two tectonically different parts.This means that the tectonic differences between the eastern and western part of the-Chinese contnent may exist in the whole upper mantle.