论文部分内容阅读
地磁倒转是地球演化史上的全球性重大事件.由于对地球内部物质和运动的认识不足,目前我们尚不清楚地磁倒转的确切原因.不过,相关研究也取得了明显的进展,现在已经知道地磁场是由地球外核的磁流体发电机过程所产生,数值模拟和实验已能再现一个与地磁场时空特征相似的磁场,并从中发现了磁场的自发倒转现象.由于数值模拟和实验的近似程度远未达到地球的真实情况,地磁倒转的自发性目前还不能予以确认.近年来的研究发现,虽然地磁场起源于地球外核,但其他圈层的物性参数分布和运动,如下地幔和地核的电导率分布、地幔对流、板块运动、内核生长等因素都影响或控制着地磁倒转的过程和频率,这些外部因素是否是引起地磁倒转的原因需要进一步的研究.本文简要介绍了地磁场的时空特征和形成机制,评述了地磁倒转的研究进展,并指出在深入探知地球内部信息的基础上,将地球各圈层的相互作用等因素进行统一考虑,构建综合性模型,是未来地磁场及其倒转机制研究的方向.
Geomagnetic inversion is a major global event in the evolution of the Earth and it is not clear exactly why the magnetism is reversed due to the lack of understanding of the matter and movement inside the Earth.However, significant progress has been made in related researches, and it is now known that the geomagnetic field Is generated by the magnetoelectric generator process outside the Earth’s core. Numerical simulations and experiments have been able to reproduce a magnetic field similar to that of the geomagnetic field, and find that the spontaneous reversal of the magnetic field can be found. Since the numerical simulation is far from the experiment The spontaneity of geomagnetic reversal can not be confirmed until the earth’s real situation has been reached, and recent studies have found that while the geomagnetic field originates from the extragalactic core, the distribution and movement of physical parameters of other layers are as follows Conductivity distribution, mantle convection, plate motion and kernel growth all affect or control the process and frequency of geomagnetic inversion, and whether these external factors are the cause of geomagnetic inversion needs further study.In this paper, the temporal and spatial characteristics of geomagnetic field And forming mechanism, reviewed the research progress of geomagnetic inversion, and pointed out that in-depth exploration Base ball inside information on the interaction of various spheres of the Earth and other factors were considered together, to build a comprehensive model, the direction of future research field and its reversal mechanism.