Fast Moves; August 1993; Scientific American Magazine; by Corey S. Powell; 3 Page(s)
The ground must still tremble before seismologists can collect data on earthquakes, but the speed at which they can analyze the abrupt shifts of faults is surpassing the swiftness of the shock waves. Indeed, it is now possible to provide a crucial warning of a few seconds for some aftershocks. And while attempts to predict earthquakes have met with mixed success, researchers may soon be able to anticipate the effects of an initial tremor, enabling railroads to stop or slow their trains and permit elevator systems to halt at the nearest floor. "It is a tremendous development," says Hiroo Kanamori of the California Institute of Technology, which helps to operate one of the leading earthquake research centers.
Such warnings are becoming possible now that seismic analysis can be completed practically in real time. Seismic stations around the globe are linked by telephone lines, which gives them nearly instantaneous access to readings recorded after an earthquake. Seismologists transmit their analyses of the tremor--its location, depth, magnitude and the orientation of the fault, for instance--to their colleagues through the Internet with equal rapidity. Moreover, researchers have developed streamlined methods for picking the most relevant information out of the seismic data. "Analysis that would have taken many months 10 years ago now happens in hours or less," says Thorne Lay of the University of California at Santa Cruz.