The map depicts five liquefaction hazard zones for the greater San Juan metropolitan area that range from very low hazard to very high hazard. This map shows the likelihood of liquefaction in Northern Santa Clara County during a magnitude 7.8 earthquake on the northernmost segments of the San Andreas Fault. The liquefaction zones shown in dark green are well-known — landfill areas including the Marina, Fisherman's Wharf, Dogpatch and South of Market. Hazard Zone Map for the San Jose West 7.5-minute Quadrangle, Santa Clara County, California. Preliminary maps of Quaternary deposits and liquefaction susceptibility, nine-county San Francisco Bay region, California: a digital database: USGS: OF 00-444: 275: Lettis, W.R. 1982: Late Cenozoic stratigraphy and structure of the western margin of the San Joaquin … Staff Directory In the South Bay and along the Peninsula, one massive liquefaction zone extends from SFO down through most of Santa Clara and San Jose. Development Related Inquires: Phone: (408) 535-3555 Email. Such areas along the Bay margins are found in San Francisco, Oakland and Alameda Island, as well as other places around San Francisco Bay. Map users may search for a … Map users may search for a … The map predicts the approximate percentage of each designated area that will liquefy and show surface manifestations of liquefaction such as sand boils and ground cracking. Maps showing the probability of surface manifestations of liquefaction in the northern Santa Clara Valley were prepared with liquefaction probability curves. DOC Maps: Geologic Hazards The California Geological Survey, a division within the California Department of Conservation, provides data and analysis of California's seismic and geologic hazards. Contact Us. The highest hazard areas shown by the liquefaction hazard maps are concentrated in regions of man-made landfill, especially fill that was placed many decades ago in areas that were once submerged bay floor. Bay Area seismic maps The Seismic Hazards Mapping Act (Act) of 1990 (Public Resources Code, Chapter 7.8, Section 2690-2699.6) directs the Department of Conservation to identify and map areas prone to earthquake hazards of liquefaction, earthquake-induced … (A more detailed map of the Marina's liquefaction zones can be found here. The map displays the boundaries of Zones of Required Investigation for liquefaction and earthquake-induced landslides over an area of approximately 60 square miles at a scale of 1 inch In the South Bay and along the Peninsula, one massive liquefaction zone extends from SFO down through most of Santa Clara and San Jose. A new map released by the California Geological Survey shows seismic hazard zones for certain areas of San Mateo and Contra Costa counties, specifically liquefaction and landslide zones. Extensive swamp deposits and artificial fill over swamp deposits containing loose sandy soils occur in these areas. Faults Earthquakes occur when forces underground cause the faults beneath us to rupture and suddenly slip. This earthquake is similar to the 1906 San Francisco earthquake. Public Works Development Services 200 E. Santa Clara St. San Jose, CA 95113. Landslide-prone areas are marked in light blue…