For most Americans, January 17, 1994 was a holiday. The date marked the anniversary of Martin Luther King, Jr.'s birthday. Government offices were closed and observance ceremonies were attended. For the residents of Los Angeles, however, January 17 was be spent quite differently. On that particular Monday morning, the city awoke to natural disaster. The temblor struck at 4:31 a.m. local time. It had been roughly six decades since a major earthquake had occurred directly under an urban area in the United States. The event resulted in the loss of life, thousands of injuries, and enormous damage. Indeed, the Northridge earthquake eventually proved to be the costliest natural disaster in the nation's history.
California earthquakes are tectonic in nature. They result from the relentless motion of two crustal plates, the Pacific plate and the North American plate. These giant slabs of the Earth's crust literally "float" upon the "hot, sticky mantle" (Blakeslee A20). At present, the Pacific plate is moving in a northwesterly direction relative to the North American plate. This movement occurs at a rate of about one inch per year.
Many areas of California have been highly active geologically for quite some time. In fact, the state is broken into a series of crustal blocks separated by faults. Within the Los Angeles basin, for example, there exists a huge network of faults extending over a 3,600-square-mile area (Blakeslee A20). These great fractures form lines of weakness in the masses of rock at the earth's surface (Iacopi 10-25). Earthquakes are associated with movement along such faults. The temblors involve the slow build-up and sudden release of strain within the planet's crust (Iacopi 10-25).
Earthquakes rarely occur as isolated events. Rather, major tectonic shifts are frequently accompanied by minor movements on the same or related fault planes. These minor movements may result in either foresh...