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地球内部物理和演化的几个核心论题:I.地球内部结构和物理性质

陈胜早   

  1. Ottawa—Carleton Geoseienee Center and Dept.of Earth Sciences Carleton University,Ottawa,ONKIS 5116,CANADA
  • 收稿日期:1997-09-20 修回日期:1997-09-20 出版日期:1997-09-20 发布日期:1997-09-20

KEY T0PICS 0N PHYSICS AND EVOLUTION OF THE EARTH’S INTERIOR: 1.EARTH STRUCTURE AND PHYSICAL PROPERTIES

Cheng Sheng-zao   

  1. Ottawa-Carleton Geosciences Center and Department of Earth Sciences, Carleton University, Ottawa, ONKIS 5B6, CANADA
  • Received:1997-09-20 Revised:1997-09-20 Online:1997-09-20 Published:1997-09-20

摘要: 本文综述研究地球内部结构和物理特性的几种常见规方法和主要研究结果,并首重讨论地球物理状态方程,地震成象,综合反演,高温高压实验和有关对比研究方法,均匀各向同性球对球模型仍不失其参考意义,但最新研究结果表明,地球内部状态是非均匀和各向异性的,横向不均匀对称地球模型仍不其参考意义,但最新研究结果表明,地球内部状态是非均匀和各向异性的,横向不均匀性主要表现在上地幔部分,下地幔和液态外核似乎比较均匀,但核-幔边界过渡带(D″)可能代表一个内含非均匀化学边界的热边界层,其形态起伏和横向变化影响地球模壁的球对称性。3-D地震成象实质上反映地震波建与温度异常的关系.而温度变化又会引起密度异常,因而密度变化是控制地幔对流的关键参数之一。

Abstract: Some important methods and main results from studies of physics and evolution of the Earth’s interior were reviewed in this paper, with an emphasis on the areas such as geophysical equations of state, seismic tomography, integrated inversions, high-temperature an d high-pressure experiments, and their comparative studies. The most updated findings have demonstrated that the Earth’s interior is heterogeneous and anisotropic, even though the homogeneous, isotropic, and symmetric spherical model nowadays can be still taken as a reference mode1. The lateral heterogeneity is mainly found in the upper mantle, while the lower mantle and the outer core of liquid state seem to be relatively homogeneous. The core-mantle boundary(CMB)transition zone (D″). however, is most likely a heterogeneous chemical boundary layer embedded in a thermal boundary layer, with a temperature drop of several hundred degrees, where its topographic undulation and lateral heterogeneity will affect the spherical symmetry of the Earth mode1. Results from 3-D seismic tomography reflect, in practice, the relationship between velocity and temperature anomalies, whereas the temperature variations further lea to on anomalous change in density, and hence, the parameter density is one of essential cont factors in mantle convection modeling.