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ind, a stream of charged particles emanating from the Sun. Its magnitude at the Earth’s surface ranges from 25 to 65 microteslas (0.25 to 0.65 gauss).[3]
Approximately, it is the field of a magnetic dipole currently tilted at an angle of about 11 degrees with respect to Earth’s rotational axis, as if there were a bar magnet placed at that angle at the center of the Earth.
The North geomagnetic pole, located near Greenland in the northern hemisphere, is actually the south pole of the Earth’s magnetic field, and the South geomagnetic pole is the north pole.
The magnetic field is generated by electric currents due to the motion of convection currents of molten iron in the Earth’s outer core driven by heat escaping from the core, a natural process called a geodynamo.
While the North and South magnetic poles are usually located near the geographic poles, they can wander widely over geological time scales, but sufficiently slowly for ordinary compasses to remain useful for navigation.
However, at irregular intervals averaging several hundred thousand years, the Earth’s field reverses and the North and South Magnetic Poles relatively abruptly switch places.
These reversals of the geomagnetic poles leave a record in rocks that are of value to paleomagnetists in calculating geomagnetic fields in the past. Such information in turn is helpful in studying the motions of continents and ocean floors in the process of plate tectonics.
The magnetosphere is the region above the ionosphere that is defined by the extent of the Earth’s magnetic field in space. It extends several tens of thousands of kilometers into space, protecting the Earth from the charged particles of the solar wind and cosmic rays that would otherwise strip away the upper atmosphere, including the ozone layer that protects the Earth from harmful ultraviolet radiation.
By 800 million years the increased solar output is supposed to cook the Earth. Solution to both problems is to put the Earth in orbit around Jupiter. Tidal stresses applied to a planet can generate the needed heating to keep the center on boil. Mirrors or a parasol can address the sunlight issue. Problem solved!