地磁场的缓慢变化(周期在一年以上)称为地磁场的长期变。由于长期变不仅与地磁场起源的理论关系极大,而且对于古地磁学中的基本假定(轴向地心偶极子假说)有着头等重要的意义,因此,近来颇受重视,讨论相当热烈。 讨论的中心问题之一是所谓地磁极的章动(Wobble)。对于这一问题,各家的观点极为分歧。 Vesrine et al.(1963)通过对地磁场的观测资料所做的球谐分析,得出结论说,“没有 The slow changes in geomagnetic field (more than one year cycle) are called long-term changes in geomagnetic field. As long-term changes are not only of great theoretical relevance to the origin of geomagnetic fields, but also of paramount importance for the basic assumptions of paleomagnetism (axial geocentric dipole hypothesis), they have received considerable attention recently and have been widely discussed. One of the central issues discussed is the so-called Wobble of polar poles. The views of all sides are extremely divided on this issue. Vesrine et al. (1963), based on the spherical harmonic analysis of the observations of the geomagnetic field, concluded that "no