Maps of quaternary deposits and liquefaction susceptibility in the Central San Francisco Bay Region, California

Abstract

This database, identified as 'Maps of Quaternary deposits and liquefaction susceptibility in the Central San Francisco Bay Region, California', has been approved for release and publication by the Director of the USGS. Although this database has been reviewed and is substantially complete, the USGS reserves the right to revise the data pursuant to further analysis and review. This database is released on condition that neither the USGS nor the U.S. Government may be held liable for any damages resulting from its use. 3. description of mapping, including description of mapping techniques and units and of the liquefaction interpretation. Part 4 is the digital spatial database: 4. Quaternary deposits and liquefaction susceptibility database. Parts 5 and 6 are graphic plot files for map sheets 1 and 2 at a scale of 1:200,000: 5. map sheet 1: plot file of the Quaternary deposits map, including an explanation of map units; 6. map sheet 2: plot file of the liquefaction susceptibility map. Part 7 is the database package, consisting of the spatial database (either coverage or shape file format) together with the three text files and metadata file. Part 8 is the plotfile package, with files in either postcript or PDF format. Part 9 is the metadata file, which is also included in the spatial database. The two colored maps are presented as digital plot files in PostScript and PDF format (image size 32 x 40 inches each). The PostScript map images (68.3 MB) can be used for viewing or plotting in computer systems with sufficient capacity, and the considerably smaller PDF files (30.4 MB) can be viewed or plotted in full or in part from Adobe ACROBAT running on Mac, PC, or UNIX platforms. The appearance of the maps in plots (colors and line weights) will depend on file type and the particular plotter that is used. The map database is provided both as an uncompressed ARC/INFO export file and as ArcView Shape files. The spatial database was compiled in vector form over the past several years using workstation ArcInfo, a

The Distribution of Red and Yellow Tags in the City of Napa

“…Thus, the correlation of damage with the pre-1950 development of central Napa does not hold for these outlying areas, and we need to consider other factors to explain the distribution of damage. Figure 3 plots the red and yellow tags against the mapped geology (Witter et al, 2006). There are several alluvial units mapped within the Napa Valley.…”

“…We compare these zones with the pre-1950 development of Napa, the recent alluvial geology of the Napa Valley (Witter et al, 2006), and the depth of the underlying sedimentary basin, as inferred from the Bouguer gravity anomaly (Jachens et al, 2006;Aagaard et al, 2010). The extent of the central damage zone is strongly correlated with the pre-1950 buildings and with the underlying sedimentary basin, but poorly correlated with the alluvial geology.…”

Liquefaction susceptibility assessment in fluvial plains using airborne lidar: the case of the 2012 Emilia earthquake sequence area (Italy)

“…Wakamatsu (1992) grouped sedimentary deposits into three categories of liquefaction susceptibility (likely, possible and not likely) using geomorphological criteria and classifying geomorphological units such as natural levee, former river channel, sandy dry river channel and artificial fill as the highest level of liquefaction potential. Witter et al (2006) and Ganapathy and Rajawat (2012) combined geomorphic expression and geological characteristics to define and distinguish lithological units and to produce liquefaction susceptibility maps for the central San Francisco Bay region (USA) and Chennai city (India), respectively.…”

Liquefaction Susceptibility Map of Greece

“…Areas susceptible to liquefaction can be identified through detailed geologic, geomorphic and hydrologic mapping (Witter et al 2006). Afterwards, a prone to liquefaction area should be further investigated in detail in order to evaluate the liquefaction potential and the degree of ground and/or structural failure.…”