Modest preparations at home and at work will make a tremendous difference in our comfort, safety, and peace of mind in the aftermath of this event. Long-term earthquake forecasting leans heavily on history for evaluating earthquake occurrence probabilities. Surprisingly, little of this information can be determined by classical seismological techniques. Earthquake science now relies heavily on geological and historical investigation of past fault behavior. Geological fault studies search for ancient evidence of slip rate, the size of past offsets, and the times of past ruptures.
Investigators scan old newspapers to learn the extent and size of historical ruptures.
Earthquake forecasters estimate an average earthquake recurrence interval of 167 years. LBL's Exploratory Research and Development Fund enabled a direct study of the Hayward Fault's earthquake history. Current results of that study indicate that the fault's past ruptures occurred, on average, every 150-250 years. This appears to support the 167- year average recurrence estimated by earthquake forecasters. Following a large earthquake, the greatest concern we will probably have, after our personal safety, will be the safety and whereabouts of our families.