A vibration of geomagnetic axis around the geographic north pole in the historic time
A vibration of geomagnetic axis around the geographic north pole in the historic time
复制标题
历史时期地磁轴绕地理北极的振动
DOI：
10.1016/0012-821x(67)90010-6
复制
发表时间：
1967
期刊：
影响因子：
--
通讯作者：
K. Tokieda
中科院分区：
文献类型：
--
作者：
N. Kawai;K. Hirooka;K. Tokieda
A rapid movement of the geomagnetic dipole axis around the geographic north pole has been predicted by the present authors [11. This motion can be represented by a combination of two different rotations, the direction of motion in one being anticlockwise and in the other clockwise. The radii-of the first rotation is about 1000 krn with a period of about 1500 y whilst the second motion traces out a loop with a radius of approximately 400 krn over a period of 500 y. Consequently the geomagnetic pole desc7sbes three clockwise loops during the time it takes; to complete the main anticlockwise circle around the n, arth pole asshown in fig. 1. The wobbling motion not only explains the records of secular variation hitherto accumulated at the widely spread geomagnetic observatories over the earth's surface but also fits the archaeomagnetic data obained by many authors [2-51. Very recently an excellent series of archaeomagnetic investigations was reported by DuBois [6] who surnmarized his measurements of baked clays found in Arizona..'these were fireplaces Or hearths of American Indians, and they are elegantly dated by means of the tree-ring method. In his data the three small clockwise loops superimposed on a larger anticlockwise circle can be easily recognized. It shows a striking rescmblance to that of the combined motion we have proposed.
