Historic fence line on the San Andreas Fault showing relative movement during the 1906 earthquake. Credit: Charly Stamper
As one of ~20,000 geologists flocking to AGU Fall Meeting in San Francisco, I’ve headed out a few days early to take in a few West Coast sights. For many, the Foggy City will always be synonymous with earthquakes. San Francisco is located right on the San Andreas Fault, which is part of a larger fracture zone marking the boundary between the North American and Pacific tectonic plates. In 1906, a sudden release of stress along the San Andreas Fault resulted in a magnitude 7.8 earthquake. The city of San Francisco was ravaged by fire and over 3,000 people lost their lives. Along the fault suture, the north-west moved 6m relative to the south-east, a feature preserved in historic fence lines. More recently, the fault was responsible for the devastating 1989 Loma Prieta quake. Nobody knows when the next ‘big one’ is due, but there is no doubt that seismic activity will continue to be felt in this area. A small shake would probably go down quite well with the visitors in town!
