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This digital map database, compiled from previously published andunpublished data, and new mapping by the authors, represents thegeneral distribution of bedrock and surficial deposits in the mappedarea. Together with the accompanying text file (pamf.ps, pamf.pdf,pamf.txt), it provides current information on the geologic structureand stratigraphy of the area covered. The database delineates mapunits that are identified by general age and lithology following thestratigraphic nomenclature of the U.S. Geological Survey. The scaleof the source maps limits the spatial resolution (scale) of thedatabase to 1:62,500 or smaller.
San Francisco Bay Region Landslide Folio Part E - Map of debris-flow source areas in the San Francisco Bay region, California
These maps show, for emergency service managers in the San FranciscoBay region, the threshold rainfall that may be capable oftriggering a level of debris-flow activity likely to threatenpublic safety. The maps are products of a continuing series ofstudies that began after a catastrophic storm on January 3-5, 1982triggered 18,000 debris flows in the San Francisco Bay region,causing 25 deaths and $66 million in property damage. Thethreshold rainfall values were estimated by re-evaluating aprevious empirical analysis of data from the 1982 storm, and otherhistorical rainfall records, that normalized the rainfall intensitydata by dividing by the mean annual precipitation (MAP) of thecorresponding rain gage. The present...
CASANC - Boundaries for the Monterey Bay, Cordell Bank, and Gulf of the Farallones National Marine Sanctuaries
CASANC is a polygon coverage showing the offshore boundaries of the national marine sanctuaries (NMS) off central California: Monterey Bay NMS, Cordell Bank NMS, and Gulf of the Farallones NMS and the adjacent coastline. This is one of a collection of digital files of a geographic information system of spatially referenced data related to the USGS Coastal and Marine Geology Program "Monterey Bay National Marine Sanctuary Project" . The data were collected and analyzed between 1994 and 2000.
Geologic maps and structure sections of the southwestern SantaClara Valley and southern Santa Cruz Mountains, Santa Clara andSanta Cruz Counties, California
This digital map database, compiled from previously publishedand unpublished data, and new mapping by the authors,represents the general distribution of bedrock and surficialdeposits in the mapped area. Together with the accompanyingtext file (scvmf.ps, scvmf.pdf, scvmf.txt), it provides currentinformation on the geologic structure and stratigraphy of thearea covered. The database delineates map units that areidentified by general age and lithology following thestratigraphic nomenclature of the U.S. Geological Survey. Thescale of the source maps limits the spatial resolution (scale)of the database to 1:24,000 or smaller.
San Francisco Bay Region landslide folio part E - Map of debris-flow source areas in the San Francisco Bay region, California
This map identifies the principal areas in the San Francisco Bayregion that are likely to produce debris flows, which are alsocalled "mudslides." Debris flows that occur in the bay region arefast-moving downslope flows of mud that may include rocks,vegetation, and other debris. These flows begin during intenserainfall as shallow landslides on steep slopes. The rapid movementand sudden arrival of debris flows pose a hazard to life andproperty during and immediately following the triggering rainfall.Debris flows in a given storm originate from a number of sourcesscattered throughout steep parts of the landscape, as shown infigure 1 (on map sheet; files sfbr- df.ps, al-df.ps, etc.). Duringsubsequent storms, new debris...
General distribution of geologic materials in the southern San Francisco Bay region, California: A digital map database
The ssfb_m1 digital map database, which is compiled from 1970'svintage sources, represents the general distribution and identityof geologic materials in the southern San Francisco Bay region,California, west of the Calaveras fault. It is not a geologic map,because it does not address the geologic structure or thestratigraphic organization of the map units in a systematic way.Instead, it is directed at the distribution and character of thegeologic materials following the pattern of its progenitors,Wentworth and others (1985) and Ellen and Wentworth (in press).Consultation of these reports and the other compilation sources willaid in using the database.
San Francisco Bay region landslide folio part D - Index to detailed maps of landslides in the San Francisco Bay region, California
A table keyed to 171 topographic quadrangles on a new1:275,000-scale shaded-relief map speeds access to information onlandslide locations in the ten-county San Francisco Bay region.Detailed maps showing individual landslides in nearly any area ofinterest can be found quickly by knowing only the name of theappropriate 7.5' quadrangle. The some-80 technical reports thatcontain these maps may be consulted in the U.S. Geological Survey'sMenlo Park library collection.
San Francisco Bay region landslide folio part C - Summary distribution of slides and earth flows in the San Francisco Bay region, California
The distribution of landslides evident in the landscape -- most ofwhich are slumps, translational slides, and earth flows -- is ofinterest both for evaluation of hazard and risk and for use infurther study of landslides. Future movement of such landslides ismost likely to occur within and around the places where they havepreviously occurred. A map showing the generalized distribution ofthese landslides was published by Nilsen and Wright for the 9-countySan Francisco Bay region in 1979. Original sources available at thetime of that compilation were incomplete for the region. Landslidemapping that has since become available provides a basis forrevision and extension of that work, and modern procedures allowthis to...
This Open-File report is a digital geologic map database. Thisdigital map database is prepared from a previously published map byBrabb (1989). The geologic map database delineates map units thatare identified by general age, lithology and clast size followingthe stratigraphic nomenclature of the U. S. Geological Survey.
Some of the benefits that can be derived from these geologic maps are:>1. Materials properties>2. Earthquake shaking>3. Liquefaction potential>4. Ground water pollution>5. Relating landslides>6. Location of mineral hazards>7. Seismic velocity>8. Earthquake faults>9. Education and scientific inquiry
Digital Compilation of "Preliminary Map of Landslide Deposits in Santa Cruz County, California, By Cooper-Clark and Associates, 1975": A Digital Map Database
A 1:62,500-scale black-and-white map identifying some 2,000landslides of various types in Santa Cruz County, California, hasbeen converted to a digital-map database that can be acquired fromthe U.S. Geological Survey over the Internet or on magnetic tape.
Preliminary Geologic Description of the San Jose 30 X 60 Minute Quadrangle, California: A Digital Database
The San Jose 30 x 60-minute quadrangle straddles the CaliforniaCoast Ranges southeast of San Francisco, and extends from west ofthe San Andreas fault near Santa Cruz on the southwest (long. -122�,lat. 37�) to the San Joaquin River in the Central Valley on thenortheast (long. -121�, lat. 37.5�). The map is a new geologiccompilation that is based on extensive previous work by many authorsand a great deal of new mapping, largely at 1:24,000, much of whichis previously unpublished.This report presents the preliminary geologic map of the San Jose 30x 60-minute quadrangle at a scale of 1:100,000, and consists of aspatial database of nine layers, two colored map sheets (geologicmap and correlation diagram), and a descriptive...
A digital version of the 1970 US Geological Survey topographic map of the San Francisco Bay region, three sheets, 1:125,000
This Open-File report is a digital topographic map database. Itcontains a digital version of the 1970 U.S. Geological Surveytopographic map of the San Francisco Bay Region (3 sheets), at ascale of 1:125,000.
Point coverage J498MBPTfor Ano Nuevo to Santa Cruz, California -A Photographic Tour of the Coastline
This data set consists of the point locations from whichdigital photographs were collected by Henry Chezar, USGS,on November 4, 1998, on the R/V David Johnston,associated with a marine data collection activityreferred to by the USGS/CMG Activity ID: J-4-98-MB
NET60MIN, NET15MIN, NET7_5MIN - Geographic graticules for the Monterey Bay National Marine Sanctuary
NET60MIN, NET15MIN, and NET7_5MIN are reference graticules covering the Monterey Bay National Marine Sanctuary and adjacent areas at intervals of 1 degree, 15 minutes, and 7.5 minutes, respectively. This is one of a collection of digital files of a geographic information system of spatially referenced data related to the USGS Coastal and Marine Geology Program "Monterey Bay National Marine Sanctuary Project" . The data were collected and analyzed between 1994 and 2000.