Charles Richter one said that only fools, charlatans and liars predict earthqakes, but NOVA video explores scientific efforts to find the indicators that show a major seismic event is about to happen. A U. S. Geological Survey experiment, based on the ob servation of a burst of low frequency radio waves just before the 1989 Loma Prieta Earthquake, is described. Written and produced by Charles Charlson; narrated by Avery Brooks. Closed captioned.