Laserfiche WebLink
Figure 2: Timeline of Earthquake and Population Growth in the San Francisco Bay <br />Bay Area Earthquakes (>M6.0) <br />❑ata Sources: <br />I. boyareacensus.co.gov <br />2. Ellsworth (19901 <br />aver this 58 year period the 2014 M6.0 <br />Bay Area region did not South Napa <br />experience a M6.4 or greater L <br />earthquake while the region <br />added four million people. 1989 M6.9 <br />Lorna Preta <br />5.1.3 Probability of Future Earthquakes <br />A powerfully damaging earthquake similar to the 1906 earthquake or 1989 Loma Prieta <br />earthquake are rare but likely to occur in the next 30 years. The United States Geological <br />Survey (USGS) estimates there is a 72% chance of one or more magnitude 6.7 or larger <br />earthquakes in the next 30 years on one of the Bay Area's faults.' Smaller magnitude <br />earthquakes are more likely to occur, potentially producing significant local damage, as <br />experienced in the 2014 South Napa earthquake <br />Scientists continually study which Bay Area faults are more likely to produce large <br />earthquakes, and how often. In March 2015, the USGS released an update to its 2008 <br />earthquake probabilities for California faults. The Uniform California Earthquake Rupture <br />Forecast 3 (UCERF3) provides detailed assessment on the likelihood of each fault segment <br />producing M6.7, M7.0 and M8.0 and greater earthquakes. These probabilities are based on <br />data such as fault length; how much energy the faults release annually through fault slip; <br />and, known historical return periods for the fault. Table 2 summarizes the probabilities of <br />future earthquakes in California. <br />s Field, E.H., et al, (2013) <br />