What You Need To Know
Delta, Sierra and Greater Sacramento Areas
Counties: Alpine, Amador, Calaveras, Colusa, El Dorado, Nevada, Placer, Sacramento, San Joaquin, Stanislaus, Sutter, Tuolumne, Yolo, Yuba
- The Delta region and the Sierra Nevada are known for their natural scenery and historic landmarks, but like the rest of the state, this is earthquake country. The mountains and the valley have been shaped by repeated earthquakes on faults in the region.
- Moderate earthquakes have occurred in the high Sierra, the foothills and in the Central Valley. These occurred on active faults found in wide zones along the crest of the Sierra Nevada, through Lake Tahoe, along the foothills, and in the western Sacramento Valley.
- Large quakes from distant faults such as those in the San Francisco Bay Area or east of the Sierra Nevada can also cause significant damage to homes, businesses, and communities, especially in areas where water levels are high in soft soils that can settle unevenly during shaking.
- Soils in lowland areas away from major faults may be subject to liquefaction. Houses on liquefied soil may settle or even move laterally on gentle slopes. Landslides are possible on steep hillsides.
How to Strengthen Your House
See the USGS interactive fault map to learn more about faults in this area
*The 76% probability of one or more magnitude 7.0 earthquakes striking Northern California is based on a 30-year period, beginning in 2014.