ABSTRACT
Virtually every region of the United States has some sort of earthquake risk. Earthquakes in the most vulnerable areas can impose enormous losses. Most Americans correctly perceive that earthquakes are a problem in California. Earthquake events of great magnitude are relatively infrequent, but they do cause widespread damage and considerable societal disruption. A swarm of earthquakes centered near the town of New Madrid, Missouri, violently shook the central Mississippi Valley beginning on December 16, 1811, and continued through the spring of 1812. Great earthquake events are not new to Alaska: Between 1899, when instrumental seismic recording began, and 1961, seven Alaska earthquakes scored magnitudes of 8.0 or higher on the Richter scale. Earthquake specialists agree that both parts of the state have enteral into cycles of increased earthquake activity that could culminate in catastrophic earthquakes. The cyclical nature of great earthquakes makes long-term forecasting of earthquake activity possible.
