ABSTRACT
Seismologists use earthquakes as “fl ash lights” to illuminate the interior of the Earth. Information extracted from the propagation of seismic waves has produced great insights into the hidden structure of our dynamic planet. Unfortunately, earthquakes are erratic “fl ash lights” that seem to go off at unpredicted times and at unpredicted places. Since they often lead to destruction and death, it is understandable that seismologists have endeavored to fi nd ways to predict-within limits as narrow as possible-time, place, and magnitude of major seismic events (Gokhberg et al., 1995; Lomnitz, 1994; Milne, 1899, Rikitake, 1976 #452; Sykes et al., 1999; Turcotte, 1991; Wyss and Dmowska, 1997). However, using the “fl ash lights” is different from understanding when and where a “fl ash” might go off. The two require different skills and different tools.
