青藏高原莫霍面的研究进展

A Review on the Moho Discontinuity beneath the Tibetan Plateau

本文首先简要回顾了莫霍面的发现 ,介绍其基本性质 ,然后对青藏高原莫霍面研究的重要进展进行了评述。在区域尺度上 ,被动源地震 (天然地震 )方法研究结果勾勒出青藏高原地壳及岩石圈底部的深部构造轮廓。然而受分辨率的限制 ,天然地震结果给出的地壳及上地幔结构的细节不足。近年来已经用分辨率达到几千米甚至百米级的主动源地震 (包括宽角反射与折射地震和深反射地震 )方法 ,揭示出青藏高原地壳及上地幔的精细结构。本文对近 30年来深地震探测获得的青藏高原各个地块的莫霍面深度、壳幔结构和上地幔盖层速度等基本数据进行了较系统的分析 。

After a summary review of the Moho discovery and introduction of its elementary nature, this paper focus on the important advancement on Moho studies in the Tibet plateau. In the regional scale, passive source seismic (natural earthquake) research achievements sketch the deep tectonic background reached to the basement of the lithosphere. However, due to the limitation of resolution of passive source methods, the results (structure of the crust and upper mantle) generally lack of enough details. In recent decades, with the use of active source seismic (include wide angle reflection and refraction seismic profiling, near vertical reflection seismic profiling) with high resolution of several kilometer even hundreds meter, the fine structure of the crust and upper mantle beneath the Tibetan Plateau has been revealed. This paper make a systematic analysis on the basic data of the Moho depth, crust and uppermost mantle structure as well as the velocity of the uppermost mantle in the recent 30 years and have a discussion on several problems including the Moho research of the Tibetan Plateau.