Suggest ways that earthquakes may be predicted. How successful has prediction been in recent years. Explain why earthquakes of similar magnitude may cause different amounts of damage according to location and historical context.

Authors Avatar

Suggest ways that earthquakes may be predicted.  How successful has prediction been in recent years.  Explain why earthquakes of similar magnitude may cause different amounts of damage according to location and historical context.  

At 6:00 am on January 17, 1994, disaster struck southern California in the form of an earthquake that originated deep beneath the Santa Susana Mountains. Slippage occurred on a fault and the resulting earthquake damaged buildings and highways, ruptured gas lines, and created chaos in the largest metropolitan area in the western US. Every news organization had special reporters on the scene. Pictures of damage and fires as well as interviews with distraught victims formed a steady parade across television screens. Even the most jaded students were fascinated with the awesome power of the earth.

One of the greatest challenges to seismologists is to be able to predict earthquakes with enough precision to minimize loss of life and economic hardship. In an ideal world, we would know where all active faults lie, when they will rupture, and the magnitude of the next earthquake expected. Earthquake prediction is successful when it can routinely provide accurate information on time, location, and size of future earthquakes. Long-term predictions affect urban planning decisions. Intermediate predictions promote emergency preparedness and heighten awareness. Successful short-term predictions lead to evacuation orders that can save lives. Seismologists can determine probabilities of rupture for particular faults or fault systems, but these probabilities are only as good as our knowledge of past earthquakes, long-term rates of fault movement, and local fault interactions. Well-documented historical accounts, geologic and geodetic studies, and modern earthquake recordings are used to develop some understanding of a particular fault’s behavior. One of the problems encountered is that we rarely have more than one or two earthquake cycles in the historical record.  Reid’s elastic rebound theory combined with our knowledge of plate tectonics suggests that we might someday be able to predict earthquakes. The observation that some faults fail with quasi-periodic behavior is fundamental for earthquake prediction and hazard mitigation. Theoretically, if plate motions are steady, strain accumulation will increase steadily and slip will occur at regular time intervals; the amount of time between slip episodes is called the recurrence interval. There are three basic models for earthquake prediction: 1) the characteristic earthquake, 2) the time-predictable earthquake, and 3) the slip-predictable earthquake (Lay and Wallace, 1995).  Even in recent years earthquakes have been hard to predict however recently they have met some success such as, Anza Southern California, October 30, 2001 and Portola Northern California, August 10, 2001.

Join now!

Ground shaking causes most earthquake damage. The magnitude of an earthquake, distance to the earthquake focus, type of faulting, depth, and type of material are important factors in determining the amount of ground shaking that might be produced at a particular site. Where there is an extensive history of earthquake activity, these parameters can often be estimated; however, in many areas of Washington they are still poorly defined. The magnitude of an earthquake influences ground shaking in several ways. Large earthquakes usually produce ground motions with large amplitudes and long durations. In addition, large earthquakes produce strong shaking over much ...

This is a preview of the whole essay