Quaternary geology and liquefaction susceptibility, Napa, California 1:100,000 quadrangle: A digital database

Open-File Report 98-460
By: , and 



Earthquake-induced ground failures such as liquefaction have historically brought loss of life and damage to property and infrastructure. Observations of the effects of historical large-magnitude earthquakes show that the distribution of liquefaction phenomena is not random. Liquefaction is restricted to areas underlain by loose, cohesionless sands and silts that are saturated with water. These areas can be delineated on the basis of thorough geologic, geomorphic, and hydrologic mapping and map analysis (Tinsley and Holzer, 1990; Youd and Perkins, 1987). Once potential liquefaction zones are delineated, appropriate public and private agencies can prepare for and mitigate seismic hazard in these zones. In this study, we create a liquefaction susceptibility map of the Napa 1:100,000 quadrangle using Quaternary geologic mapping, analysis of historical liquefaction information, groundwater data, and data from other studies. The study is atterned after state-of-the-art studies by Youd (1973) Dupre and Tinsley (1980) and Dupre (1990) in the Monterey-Santa Cruz area, Tinsley and others (1985) in the Los Angeles area, and Youd and Perkins (1987) in San Mateo County, California. The study area comprises the northern San Francisco Metropolitan Area, including the cities of Santa Rosa, Vallejo, Napa, Novato, Martinez, and Fairfield (Figure 1). Holocene estuarine deposits, Holocene stream deposits, eolian sands, and artificial fill are widely present in the region (Helley and Lajoie, 1979) and are the geologic materials of greatest concern. Six major faults capable of producing large earthquakes cross the study area, including the San Andreas, Rodgers Creek, Hayward, West Napa, Concord, and Green Valley faults (Figure 1).

Study Area

Publication type Report
Publication Subtype USGS Numbered Series
Title Quaternary geology and liquefaction susceptibility, Napa, California 1:100,000 quadrangle: A digital database
Series title Open-File Report
Series number 98-460
DOI 10.3133/ofr98460
Year Published 1998
Language English
Publisher U.S. Geological Survey
Contributing office(s) U.S. Geological Survey
Description Report: 12 p.; 2 Plates: 42.0 x 34.0 inches; Data Files
Country United States
State California
Other Geospatial Napa quadrangle
Projection UTM Zone 10
Scale 100000
Online Only (Y/N) Y
Additional Online Files (Y/N) Y
Google Analytic Metrics Metrics page
Additional publication details