Updated: I discovered after I finished this post that there was another big earthquake today August 24, 2014. This time it was 6.9 and in a remote area of Peru. See below at the bottom of the post for more details.
An earthquake 6.1 on the Richter Scale struck the San Francisco Bay area about 1 AM PDT Sunday morning. The heaviest damage was in Napa, but Sonoma and Solano were also hit with significant damage. The epicenter was 6 miles south southwest of Napa.
Fault line maps of the Bay Area show a wide strip of parallel faults with this earthquake right in the middle of them just northeast of the main part of San Francisco Bay. In contrast, faults in the Los Angeles, Orange County area run North South and East West, although the San Andreas runs North West and South East.
About 12 hours prior to the Napa Earthquake, a 6.4 earthquake struck the community of Hacienda La Calera, Chile. This is a community near Valparaiso. There were no reports of injuries or serious damage but utility service was out in some areas. There were many aftershocks there as well as in the Bay Area earthquake. It’s all part of the Ring of Fire, where pressures that build up underground until they get released, which in turn, cause pressures to build up elsewhere and then get released.
While checking on these stories, I also noticed a lot of less dramatic earthquake activity in the area north of Oklahoma City and Edmond. The highest Richter Scale reading was 4.2. This might not mean much in our lifetime but it might be very significant in geologic time.
Update: Since I wrote that, I discovered another earthquake happened, this time in a sparsely populated area of central Peru about 290 miles Southeast of Lima, the capital city. According to the Peruvian Government, as reported in USA Today, there were no immediate reports of major damage or injuries. In a populated area, a 6.9 Earthquake could be really devastating. The USGS Chart is below.