Earthquakes continue to inspire awe and terror, as they have since ancient times. But now, because of the nation's prosperity, there are new concerns about the high rate of property damage in earthquake- prone areas. The quake that hit the Los Angeles area last January, for example, though moderate in scale, caused more than 60 deaths and $20 billion in destruction. The so-called Northridge quake sparked efforts to map Southern California's many geologic faults, where earthquakes commonly occur. But while understanding of earthquake dynamics is growing, geophysicists are less confident of their ability to predict major seismic events than they were 20 years ago. Meanwhile, seismologists caution that east of the Rockies, many parts of the central and eastern U.S. are at greater risk than residents think.