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Bay Area Earthquake Hazards



The San Francisco Bay Area is underlain by a complex web of active faults (see map at right). The 2008 UCERF2 Report calculates a 63% probability that the Bay Area will suffer a magnitude 6.7 earthquake or larger in the next 30 years. This earthquake hazard extends across the entire area from the well-known San Andreas to the lesser-known Greenville and Green Valley faults. If you live in the Bay Area, it is very likely that the next large earthquake will affect you: either directly, by damaging your home, neighborhood, or workplace, or indirectly, by damaging the infrastructure and economy of the area.

If a large earthquake occurs in the Bay Area, severe ground shaking or ground failure could damage your home or workplace, leaving you without shelter or without income. In densely populated neighborhoods, fires can follow earthquakes and produce greater devastation than the original ground shaking. You can mitigate this potential damage by retrofitting and insuring your home, and by taking steps to make your workplace more earthquake-safe. It is likely that a large earthquake will cut the electricity and water supply to many areas: residents are urged to store supplies of food and water that will last at least 72 hours.

The Bay Area has a vital and interdependent economy built on computers, biotech, banking, medicine, shipping, and tourism, to name a few of our many important industries. The lifelines of energy, water, and transportation are critical to this economy, and unfortunately, vulnerable to damage from earthquakes. Large earthquakes can damage infrastructure and cripple the economy through a series of smaller failures. While Caltrans, PG&E, SFPUC, and EBMUD have devoted considerable resources to retrofitting their facilities in the 20 years since the Loma Prieta earthquake, many vulnerabilities remain. Small businesses in the Bay Area cities are also at great risk to earthquake damage, and to the fires that can follow earthquakes.

Bay Area Fault Map (looking North)

All residents of the Bay Area will face challenges after a large earthquake. The loss of home and possessions, the severing of utility and transportation lifelines, and dislocation or slowdown of business are hardships that the Bay Area will suffer. Everyone in the Bay Area is responsible for being prepared for an earthquake, both at home and in the workplace. From individual citizens to schools, businesses, and local governments, residents can prepare for earthquakes so that they can survive their effects. The information on this website and at details what steps you can take to mitigate your earthquake hazard. Take the time to review this information, and Be Prepared Now!

California Governors Office of Emergency Services
Use this website to discover the hazards that exist in your area and learn how to reduce YOUR risk!

USGS Earthquake Science Center - Northern California
United States Geological Survey, Northern California

Fault and earthquake maps, shaking hazard maps, liqufaction maps, and other information
United States Geological Survey, Northern California

ABAG Earthquake and Hazards Maps/Info
Association of Bay Area Governments

Fault maps, historic earthquakes, how the ground is expected to shake, and much more
California Geological Survey (CGS)

Forecast of California Earthquakes
Southern California Earthquake Center, USGS, and CGS

Earthquake Shaking Potential Map of California (Dec. 2008)
California Geological Survey (CGS)

Maps of recent earthquakes, ShakeMaps for larger earthquakes, email notification, and more
California Integrated Seismic Network

Earthquake and Tsunami Hazards and Mitigation Information
California Governors Office of Emergency Services


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