Abstract
DR. E. C. BULLARD has described (Mon. Not. Roy. Astro. Soc., Geophys. Supp., 5,. No 7, July 1948). the rapid changes in the earth‘s magnetic filed in South africa, from which certain tentative conclusions are drown. From data in tables 25, 29 in and 33 in "Descriptions of the Earth‘s Main Magnetic and its Secular Changes", by E. H. Vestine and others (Carnegie Institution, Washington, 1947), a diagram is constructed showing the annual changes in the horizontal and vertical fields in South Africa at 1922·5 ; this date has been chosen because it is believed that the secular variations are better known then than at any other time.
Article PDF
Rights and permissions
About this article
Cite this article
Secular Changes in the Earth‘s Magnetic Field. Nature 163, 147 (1949). https://doi.org/10.1038/163147a0
Issue Date:
DOI: https://doi.org/10.1038/163147a0