Hi All. I have received a couple or e-mails asking me how a geomagnetic storm may cause an earthquake. Here is the theory as it had been told to me.

The geomagnetic storm affects the earth in several ways. First it causes a compression of the earth's atmosphere as the storm hits. This sets up a free-earth oscillation of the earth system; these small periodic vibrations could trigger earthquakes.

Secondly, electric currents are formed in the ionosphere around the geomagnetic equator and the magnetic poles. These currents induce electric currents in the earth. These currents interact with faults and water in faults to change the properties of faults leading to rupture. This is the most probable triggering mechanism.

Third, when a geomagnetic storm hits, the resulting induced electrical currents dissipate by ohmic heating. This causes a heating of magmas and results in expansion of the earth. Volcanic eruptions and earthquakes relieve the strain from this expansion.

Fourth, the geomagnetic field variations result in conflicting eddy currents in the earth's core. This causes the earth to slow or accelerate suddenly. This can also result in earthquakes.

Despite all of this we still have the same problem. How do we locate the area that has the most strain build up to produce a large quake? There is also the problem of large quakes when there is no geomagnetic storm. Where these quakes triggered by some other action, or force, or did they occur because the object causing the stress build up finely sheared? A lot of questions, but not many answers. Take Care…Don in creepy town.