Re: earthquake warning system
Some American research groups are currently experimenting by placing sensors in California to try to and figure out patterns in order to predict earthquakes. No definitive method of predicting earthquakes exist right now. Even with best case scenario, the heads up is not more than a few minutes, which is meaningless for most largely populated areas.
Check these links for more information
http://www.geophys.washington.edu/SEIS/PNSN/INFO_GENERAL/eq_prediction.html