Search results
Results From The WOW.Com Content Network
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. [6] [7]
The geographic poles are defined by the points on the surface of Earth that are intersected by the axis of rotation. The pole shift hypothesis describes a change in location of these poles with respect to the underlying surface – a phenomenon distinct from the changes in axial orientation with respect to the plane of the ecliptic that are caused by precession and nutation, and is an ...
The Brunhes–Matuyama reversal, named after Bernard Brunhes and Motonori Matuyama, was a geologic event, approximately 781,000 years ago, when the Earth's magnetic field last underwent reversal. [ 1 ] [ 2 ] Estimations vary as to the abruptness of the reversal.
British explorer Sir James Clark Ross discovered the magnetic north pole in 1831 in northern Canada, approximately 1,000 miles (1,609 kilometers) south of the true North Pole.
The Earth's magnetic North Pole is currently moving toward Russia in a way that British scientists have not seen before. ... before slowing in the last five years to about 22 miles per year ...
Polar drift is a geological phenomenon caused by variations in the flow of molten iron in Earth's outer core, resulting in changes in the orientation of Earth's magnetic field, and hence the position of the magnetic north- and south poles. The North magnetic pole is approximately 965 kilometres (600 mi) from the geographic North Pole. The pole ...
Magnetic declination varies both from place to place and with the passage of time. As a traveller cruises the east coast of the United States, for example, the declination varies from 16 degrees west in Maine, to 6 in Florida, to 0 degrees in Louisiana, to 4 degrees east in Texas.
The geomagnetic poles move over time because the geomagnetic field is produced by motion of the molten iron alloys in the Earth's outer core. (See geodynamo .) Over the past 150 years, the poles have moved westward at a rate of 0.05° to 0.1° per year and closer to the true poles at 0.01° per year.