Here is a Picture of the Day discussing far more details of the electrical effects of solar activity on the earth, featuring the work of Dr. Friedemann T. Freund.
Sunspots and Earthquakes
Dec 21, 2005
Civilization's interest in predicting the location and time of damaging earthquakes is obvious. The potential for devastation of property that otherwise could be secured, and the loss of life that otherwise could be prevented, are powerful reasons to find predictive factors.
Some scientists have become aware of a correlation between sunspots and Earthquakes and want to use the sunspot data to help predict earthquakes. The theory is that an intensification of the magnetic field can cause changes in the geo-sphere. The NASA and the European Geosciences Union have already put their stamp of approval on the sunspot hypothesis, which suggests that changes in the sun-earth environment affects the magnetic field of the earth that can trigger earthquakes in areas prone to it. It is not clear how such a trigger might work.
In the Journal of Scientific Exploration, Vol. 17, No. 1, pp. 37–71, 2003, there is an excellent report that addresses the more down-to-earth problems facing geophysicists trying to understand earthquakes. The paper is titled, Rocks That Crackle and Sparkle and Glow: Strange Pre-Earthquake Phenomena, by Dr. Friedemann T. Freund, a professor in the Department of Physics, San Jose State University, and a senior researcher at NASA Ames Research Center. Dr. Freund writes, "Many strange phenomena precede large earthquakes. Some of them have been reported for centuries, even millennia. The list is long and diverse: bulging of the Earth’s surface, changing well water levels, ground-hugging fog, low frequency electromagnetic emission, earthquake lights from ridges and mountain tops, magnetic field anomalies up to 0.5% of the Earth’s dipole field, temperature anomalies by several degrees over wide areas as seen in satellite images, changes in the plasma density of the ionosphere, and strange animal behavior. Because it seems nearly impossible to imagine that such diverse phenomena could have a common physical cause, there is great confusion and even greater controversy."
Freund outlines the basic problem, "Based on the reported laboratory results of electrical measurements, no mechanism seemed to exist that could account for the generation of those large currents in the Earth’s crust, which are needed to explain the strong EM signals and magnetic anomalies that have been documented before some earthquakes. Unfortunately, when a set of observations cannot be explained within the framework of existing knowledge, the tendency is not to believe the observation. Therefore, a general malaise has taken root in the geophysical community when it comes to the many reported non-seismic and non-geodesic pre-earthquake phenomena… There seems to be no bona fide physical process by which electric currents of sufficient magnitude could be generated in crustal rocks."
Freund makes an excellent attempt to explain all of the phenomena in terms of rock acting like a p-type semi-conducting material when placed under stress. For example, the emission of positive ions from the Earth’s surface may act as nuclei for the ground-hugging fog that sometimes occur prior to earthquake activity. And although the surface potential may only be in the 1–2-Volt range, the associated electric field can reach hundreds of thousands of Volts per centimeter, enough to cause corona discharges, or "earthquake lights."
Thermal anomalies seen from space before an earthquake may be due to the emission of infra-red light where the semi-conductor charge recombines at the surface. Disturbed animal behavior may be due to the presence of positive ions in the air.
As Freund says, this theory places an explanation in the realm of semiconductor physics, which means that geoscientists are not the best people to judge it. That explains why the paper appears in a speculative journal. Freund laments, "the peer review system often creates near-insurmountable hurdles against the publication of data that seem contrary to long-held beliefs." Freund has identified a source of charge in stressed rocks that was not believed possible. He says, "…once fully told and understood, the "story" [of p-holes] is basically so simple that many mainstream geoscientists are left to wonder why it has taken so long for them to be discovered. If they are so ubiquitous as they appear to be, why did p-holes go unnoticed for over a hundred years? Confronted with this question, by a twist of logic, many 'mainstreamers' succumb to the impulse to reject the p-hole concept out of hand.
...The missing link between the sunspots and earthquakes is the fact that the electric discharges on the Sun that cause sunspots also affect the Earth's ionosphere. The ionosphere forms one "plate" of a capacitor, while the Earth forms the other.
Changes of voltage on one plate will induce movement of charge on the other. But unlike a capacitor, the Earth has charge distributed beneath the surface. And if the subsurface rock has become semi-conducting because of stress, there is an opportunity for sudden electrical breakdown to occur through that rock. The mystery of how the current is generated is solved and the link with sunspots exposed. Subsurface lightning causes earthquakes! Seismic waves are the equivalent of the rumble of thunder. The energy released may be equivalent to the detonation of many atomic bombs but only a small proportion needs to come from the release of strain in the rocks. Most of it comes from the Earth's stored internal electrical energy.
The latest issue of the IEEE journal, SPECTRUM, features an article based on Freund's work that looks at ways of predicting earthquakes. Once again, it seems that scientific advances fare better today in the hands of electrical engineers.