[ckissick]

I used to work at the USGS on an earthquake prediction research project. We used anomalous changes in water levels in wells. The same principal applies to increases in radon gas. Just before an earthquake, there is a "strain event", or a change in the stress/strain regime. The change in strain does things to water levels, magnetic fields, and radon gas emissions. You can also make direct measures of earth strain.

China once predicted an earthquake because of changes in water levels in wells, and an increase radon gas has often been reported occurring just before an earthquake, however it's always been after the fact. The guy is not a whacko.