2014 South Napa earthquake 2014 South Napa earthquake The 2014 South Napa earthquake occurred in the North San Francisco Bay Area on August 24 at . At 6.0 on the moment magnitude scale and with a maximum Mercalli intensity of VIII ("Severe"), the event was the largest in the San Francisco Bay Area since the 1989 Loma Prieta earthquake. The epicenter of the earthquake was located to the south of Napa and to the northwest of American Canyon on the West Napa Fault. Total damage in the southern Napa Valley and Vallejo areas was in the range of $362 million to 1 billion, with
Earthquake prediction of having observed such phenomena prior to an earthquake, no such phenomena has been shown to be an actual precursor. A 2011 review found the "most convincing" electromagnetic precursors to be ULF magnetic anomalies, such as the Corralitos event (discussed below) recorded before the 1989 Loma Prieta earthquake. However, it is now believed that observation was a system malfunction. Study of the closely monitored 2004 Parkfield earthquake found no evidence of precursory electromagnetic signals of any type; further study showed that earthquakes with magnitudes less than 5 do not produce significant transient signals. The "International Commission on Earthquake Forecasting for