PREDICTING EARTHQUAKES

August 18, 2004
		In recent years, scientists have been moving ever closer to one day being able to predict when and where a major earthquake could occur. A leading scientist in earthquake prediction answers your questions about the latest developments in the field.

Online NewsHour Special Report: Predicting Earthquakes Forum Introduction What is the difference between a "return interval" and a "recurrence interval"? Seismologists study earthquakes, but who studies how to mobilize society for disaster? Why is it that the New Madrid Fault is very rarely mentioned in quake discussions? If people could turn on their TVs to find out an earthquake was coming, wouldn't there be widespread panic? Are we going to have a 19-year quake cycle here in California? What are the chances of a major earthquake through the mid-U.S.A., where none has occurred since the early 1800s?	As scientists make leaps and bounds in learning about why and how earthquakes occur, they become increasingly more likely to be able to accurately predict when a cataclysmic quake will occur. With the introduction of new technologies and the help of new tools, such as an observatory built right into the extremely active San Andreas Fault, scientists are on the brink of discoveries that could one day save millions of lives. Dr. William Ellsworth is a leader in research on understanding the earthquake cycle and the physics of earthquakes. He is an authority on the seismicity of the San Andreas Fault system, the analysis of earthquake locations, microseismicity, the seismic cycle, earthquake forecasting, earthquake nucleation, geophysical inverse theory and seismic tomography. Much of his research has played a central role in the long-term forecasts of major earthquakes in California, including the 1999 report of 30-year earthquake probabilities for the San Francisco Bay region. Ellsworth takes your questions on the latest developments in earthquake prediction.