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File:Magnetic Declination Chart for the International Geomagnetic Reference Field, 2005.pdf. Add languages. Page contents not supported in other languages.
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The following is a list of geomagnetic reversals, showing the ages of the beginning and end of each period of normal polarity (where the polarity matches the current direction). Source for the last 83 million years: Cande and Kent, 1995. [1] Ages are in million years before present (mya).
The magnetic property most useful in stratigraphic work is the change in the direction of the remanent magnetization of the rocks, caused by reversals in the polarity of the Earth's magnetic field. The direction of the remnant magnetic polarity recorded in the stratigraphic sequence can be used as the basis for the subdivision of the sequence ...
The first systematic evidence for and time-scale estimate of the magnetic reversals were made by Motonori Matuyama in the late 1920s; he observed that rocks with reversed fields were all of early Pleistocene age or older. At the time, the Earth's polarity was poorly understood, and the possibility of reversal aroused little interest.
Earth Magnetic Field Declination from 1590 to 1990. The Hydrographic Office, later the Naval Oceanographic Office, was responsible for publishing charts defining components the world magnetic field. After the non-magnetic vessel Carnegie blew up in 1909 collection of oceanic magnetic field information capability was lost. By 1951 those charts ...
Magnetic: Brunhes-Matuyama magnetic reversal. 4] Calabrian: 1.8 Vrica Section, Calabria, Italy Magnetic: Approximately 15 ka after the end of magnetic polarity chronozone C2n (Olduvai). Biologic: Immediately above extinction Discoaster brouweri .
Gauss-Matuyama reversal, approximately 2.588 million years ago; Jaramillo reversal, approximately one million years ago; Laschamp event, a short reversal that occurred 41,000 years ago; Reversal of the solar magnetic field; Magnetization reversal, a process leading to a 180° reorientation of the magnetization vector with respect to its initial ...