Chart-making of the Earth's main magnetic field

Abstract

[1]  Methods of magnetic prospecting have long history. Investigations of geomagnetism started when magnetic iron ore (rock rich of magnetite) was found. It is believed that a few hundreds years B. C. the Chinese were the first ones to use properties of magnetic iron ore to point out the directions. However, a thought that the Earth itself acts as a magnet appeared considerably later. First information on the use of magnetic compass in Europe relates to the end of XII century. Ideas on geomagnetic field, its direction and effects were put onto scientific grounds after the book "About magnet, magnetic bodies and about big magnet - the Earth'' had been published. Systematic quantitative investigations on the direction of the magnetic field of the Earth commenced in London over the lifetime of Gilbert. In Sweden as early as 1640, observations of local anomalies of the geomagnetic field direction were used for the prospecting of the iron ore. Sphere of application of magnetic methods covers different areas of geomagnetism, magnetism of rocks, paleomagnetism, magnetic prospecting, navigation on the basis of magnetometry, effects of magnetic field variation on human health, including crews of air-crafts, etc. Variety of applications of magnetic methods is so broad that it is practically impossible to consider all aspects in one paper. Apart from that, by now the most effective results of research of geomagnetism are connected with getting data on such imagination taking hypotheses as continental drift, sea floor spreading and plates tectonics, movement of geographical and magnetic poles, etc. Intensity of geomagnetic field is measured from satellites, air-crafts/planes, ships, as well as in observatories, and then classified, formed and recorded every 5 years since 1945. Non-systematic measurements have been carried out considerably earlier. However, until now there is no sufficient visual interpretation of data on geomagnetic field with the purpose of its reliable analysis and study for the further fundamental and applied research. This work offers cartographic method of interpretation of geomagnetic field measurements, creation of geographic maps of the magnetic field of the Earth, and creation of geoinformation system.

Received 22 November 2007; accepted 15 December 2007; published 10 May 2008.

Keywords: geomagnetic field, magnetic anomaly, Earth's main magnetic field, geographical map.

Index Terms: 0925 Exploration Geophysics: Magnetic and electrical methods; 1500 Geomagnetism and Paleomagnetism; 1517 Geomagnetism and Paleomagnetism: Magnetic anomalies: modeling and interpretation.

Citation: Zhalkovsky, Ye. A. (2008), Chart-making of the Earth's main magnetic field, Russ. J. Earth Sci., 10, ES4003, doi:10.2205/2007ES000258.