Earth’s Magnetic Field

Welcome to the very first blog for our MagneHealth website.  Given that this is a site dedicated to information about all things magnetic, the fact that within the past couple of weeks, a British astronaut has joined the International Space Station team for 6 months, seemed an ideal opportunity to link that event with some information about Earth’s magnetic field. 

This geo-magnetic field extends from the Earth’s interior to where it meets the solar wind.  The magnetosphere is the region above the ionosphere and extends several tens of thousands of kilometres in space, protecting us 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.

Although our North and South magnetic poles wander widely, it is sufficiently slowly for ordinary compasses to remain useful for navigation.  But at irregular intervals, averaging several hundred thousand years, the Earth’s magnetic field reverses and the poles abruptly switch places.  These reversals leave a record in rocks that can help paleomagnetists to calculate geomagnetic fields in the past.  This in turn can help in the study of motions of continents and ocean floors in the process of plate tectonics.