West Napa Fault
The West Napa Fault is a 57 km (35 mi) long
It has been mapped as a Late Pleistocene-Holocene active fault, and is considered to be predominantly a right lateral strike-slip fault.[1] The fault was discovered in 1976 by Gene Boudreau, a ground water drilling specialist from Sebastopol.[2] In 2023 there was data showing that the West Napa Fault is actually nine miles longer than previously known.[3]
Earthquakes
The West Napa Fault is a likely source for the magnitude 6.0 South Napa earthquake that hit Napa County on August 24, 2014.[4] Seismologists were not able to determine the exact fault on which the quake occurred, because faults are usually identified by their expression on the surface.[5]
The epicenter for the 2000 Yountville earthquake which occurred on September 3, 2000, is also near the West Napa Fault.[6]
See also
- Green Valley Fault – northern extension of the East Bay Concord Fault.
- Geology of Napa County, California
- Quaternary California
References
- ^ Wesling, John R.; Hanson, Kathryn L. (2008). "Mapping of the West Napa Fault zone for input into the Northern California Quaternary Fault Database" (PDF). United States Geological Survey. Retrieved 25 August 2014.
- ^ Jensen, Peter (August 31, 2014). "A lesser fault line blamed for Sunday's earthquake". Napa Valley Register. Napa, CA: Lee Enterprises, Inc. Retrieved August 31, 2014.
- ^ Fault line that caused 2014 Napa quake longer, potentially stronger than previously thought: USGS, ABC7 News San Francisco, 26 December 2023
- ^ Perlman, David (24 August 2014). "Little-known fault suspected in Northern California quake". San Francisco Chronicle. Retrieved 25 August 2014.
- ^ "Which fault is it?". Seismo Blog. 24 August 2014. Retrieved 27 August 2014.
- ^ Courtney, Kevin (September 2, 2001). "Shake up call". Napa Valley Register. Napa, CA: Lee Enterprises, Inc.