The study of Earth's magnetism (1269–1950): A foundation by Peregrinus and subsequent development of geomagnetism and paleomagnetism

Abstract

This paper summarizes the histories of geomagnetism and paleomagnetism (1269–1950). The role of Peregrinus is emphasized. In the sixteenth century a debate on local versus global departures of the field from that of an axial dipole pitted Gilbert against Le Nautonier. Regular measurements were undertaken in the seventeenth century. At the turn of the nineteenth century, de Lamanon, de Rossel, and von Humboldt discovered the decrease of intensity as one approaches the equator. Around 1850, three figures of rock magnetism were Fournet (remanent and induced magnetizations), Delesse (remagnetization in a direction opposite to the original), and Melloni (direction of lava magnetization acquired at time of cooling). Around 1900, Brunhes discovered magnetic reversals. In the 1920s, Chevallier produced the first magnetostratigraphy and hypothesized that poles had undergone enormous displacements. Matuyama showed that the Earth's field had reversed before the Pleistocene. Our review ends in the 1940s, when exponential development of geomagnetism and paleomagnetism starts.

Alexander von Humboldt's charts of the Earth's magnetic field: an assessment based on modern models

“…1). It was measured with an inclinometer (dip meter), which consisted of a magnetized needle able to rotate in the vertical plane (Courtillot and Le Mouël, 2007). Declination and inclination were the first measurements to be made (since 16th century), which allow to obtain only directional data at a point.…”

The HISTMAG database: combining historical, archaeomagnetic and volcanic data

“…The discovery of declination in Europe is attributed to sundial designers of the 15th century (e.g. Balmer 1956;Chapman & Bartels 1962), who marked the value on the compass attached to the sundial to guarantee an accurate orientation. The earliest known value was recorded by Georg Peuerbach in 1451 (Zinner 1939).…”

“…Chapman & Bartels 1962), monitoring of the geomagnetic field started at individual locations like London (Malin & Bullard 1981) or Paris (Alexandrescu et al 1996). The spatial variation of geomagnetic directions was investigated during several marine voyages, which led to the first isogonic chart of the Atlantic by Halley (1701).…”

“…During the late 18th and in the beginning of the 19th century, the first iron-free observatories were constructed (e.g. Chapman & Bartels 1962), while the systematic observation of all geomagnetic field components on a global scale is marked by the initiation of the 'Göttingen Magnetic Union' by Gauss and Weber in 1830s. Gauss (1833) complemented geomagnetic measurements with his method for absolute field intensity determination; earlier-from the end of the 18th century-relative values had been derived from the oscillation period of the needle displaced from its rest position (e.g.…”

“…Chapman & Bartels 1962): Alexander Neckham wrote about the common use of the magnetic needle to indicate 1348 P. Arneitz et al north for mariners and described a compass, where a needle was placed on a pivot. A more detailed design of a pivoted compass as well as the concept of magnetic poles were given by Petrus Peregrinus (e.g.…”