New tsunami hazard maps highlight threat facing seven California counties — even Napa is up for discussion
A map of the 2011 Tohoku earthquake and tsunami disaster as seen from the air (Source: USGS)
California has updated its earthquake hazard maps for seven of its nine counties, including for Napa and San Francisco.
The updated maps highlight the threat for the state’s wine country and its agricultural heartland, which are located in the path of an earthquake on the San Andreas Fault.
The updated hazard maps cover the county from the coast to the top of the Central Valley in the north, along the Sierra Nevada range from the eastern border of San Francisco to Lake Tahoe in the south, and along the Santa Clara Valley and the Central Coast from Napa to San Luis Obispo in the south.
The updated maps are available for each county’s residents to view and change their home-safety planning needs based on the likelihood of an earthquake occurring in their area.
“Our updated hazard maps reflect an ongoing review of earthquake hazards and updates based on earthquake research and field data. The new maps now incorporate improvements and changes to the Bay Area’s earthquake safety plan, updated U.S. Geological and California Geological Survey earthquake hazard maps, and improved information on natural hazard hazards,” said Dr. Matthew J. Hallett, director of the California Natural Hazards Program at the U.S. Geological Survey.
The new hazard maps have been produced in several phases over the past year.
Phase one involved the creation of new hazard maps for seven counties: Amador, Butte, Butte County, Colusa, Sonoma, Solano, and Napa.
Phase two included creating hazard maps for Sonoma and Solano counties, as well as the southern portion of Santa Maria County.
The final phase involved the creation of hazard maps for the northern part of Santa Barbara County and the western most part of San Luis Obispo County.
The county hazard map update process is aimed at ensuring residents in the earthquake paths of the six major faults: San Andreas, Tehachapi-Corona, San Francisquito-Plaster River, Redlands-Ventura, Kern-Hillsdale, and Elsinore-Horseshoe Bend.
“While these maps are being updated, residents may notice small changes in current hazard classifications, or an increase in risk or intensity
