Earthquakes
The US Geological Survey (USGS) has consistently increased its probability forecast for a major Bay Area earthquake: from 65% in 1990, to 70% in 1992, to 80% in 1997. Each number is an estimate of the probability of an earthquake measuring 7.0 or larger on the Richter scale within 30 years of the date the estimate was made.
In a 1990 report, the USGS stated that "...it seems likely that in 1979 we began a new era of major earthquake activity." A report released to the public in late 2003 provides additional evidence that Northern California earthquakes occur in cyclical patterns with several decades of dormancy followed by several decades of high seismic activity. The suggestion is that Northern California has just passed through a dormant period and is early in a period of higher seismic activity.
Shaking Intensity in the Bay Area: The epicenter of the 1989 Loma Prieta earthquake was in the Santa Cruz Mountains, distanced some 30-70 miles from Bay Area cities. The USGS warns that should an earthquake strike at one of the closer fault areas, such as the Hayward fault, shaking in local cities can be expected to be 5 to 12 times stronger than it was in 1989.
Community-Wide Effects: The Association of Bay Area Governments (ABAG) estimates that after an earthquake a potential housing loss to Bay Area communities of over 159,000 units. This would have disastrous effects on our local and regional economies. It also means that recovery, repair and rebuilding time for every household will be very lengthy, due to the number of homes that will need repairs or replacement. Households that are less damaged will certainly make much faster recoveries.
Increasing Importance of Prevention: The cost of earthquake insurance has increased dramatically. At the same time, benefits have decreased. Many homeowners have made a conscious choice to accept the earthquake risk personally by declining earthquake coverage. Governmental resources to help with damage recovery, especially at the personal level, are declining. All these factors, together, make it even more critical to focus on the prevention of earthquake-related damages.
Prevention Pays: Based on extensive post-earthquake evaluations, experts agree that structural damage can be greatly reduced by following recommended practices of seismic retrofitting. Retrofitting will reduce the cost of repair, and may even prevent structural damage altogether. The benefits go well beyond being simply financial. It will make your home safer and help to keep it habitable following a major disaster. It will also reduce the amount of time and effort needed for recovery, returning your family much more quickly back to your normal life style.
