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This map describes the possible hazard from earthquake-induced landslides for the city of Berkeley, CA. The hazard depicted by this map was modeled for a scenario corresponding to an M=7.1 earthquake on the Hayward, CA fault. This scenario magnitude is associated with complete rupture of the northern and southern segments of the Hayward fault, an event that has an estimated return period of about 500 years. The modeled hazard also corresponds to completely saturated ground-water conditions resulting from an extreme storm event or series of storm events. This combination of earthquake and ground-water scenarios represents a particularly severe state of hazard for earthquake- induced landslides. For dry ground-water...
This digital map database, which is compiled from previouslyunpublished and open-filed U.S. Geol. Survey reports (Wesling andHelley, 1989), represents the general distribution and identity ofQuaternary deposits in eight 7.5 minute quadrangles in the southernSan 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...
This map describes the possible hazard from earthquake-inducedlandslides for the city of Berkeley, CA. The hazard depicted bythis map was modeled for a scenario corresponding to an M=7.1earthquake on the Hayward, CA fault. This scenario magnitude isassociated with complete rupture of the northern and southernsegments of the Hayward fault, an event that has an estimatedreturn period of about 500 years. The modeled hazard alsocorresponds to completely saturated ground-water conditionsresulting from an extreme storm event or series of storm events.This combination of earthquake and ground-water scenariosrepresents a particularly severe state of hazard for earthquake-induced landslides. For dry ground-water conditions,...
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...
Contra Costa County is located at the northern end of the DiabloRange of Central California. It is bounded on the north byCarquinez Strait, through which flows 27 percent of California'ssurface water runoff. San Francisco Bay forms the westernboundary, the San Joaquin Valley borders it on the east and theLivermore Valley forms the southern boundary. Contra Costa is oneof the nine Bay Area counties with streams that are tributaries toSan Francisco Bay. Most of the county is mountainous with steeprugged topography. Mount Diablo, in the center of the county, isone of the highest peaks in the Bay Area, reaching an elevation of1173 meters (3,849 ft). Contra Costa County is covered bytwenty-five 7.5' topographic Quadrangles...
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.
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.
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...
Alameda County is located at the northern end of the Diablo Range ofCentral California. It is bounded on the north by the south flankof Mount Diablo, one of the highest peaks in the Bay Area, reachingan elevation of 1173 meters (3,849 ft). San Francisco Bay forms thewestern boundary, the San Joaquin Valley borders it on the east andan arbitrary line from the Bay into the Diablo Range forms thesouthern boundary. Alameda is one of the nine Bay Area countiestributary to San Francisco Bay. Most of the country is mountainouswith steep rugged topography. Alameda County is covered bytwenty-eight 7.5' topographic Quadrangles which are shown on theindex map (alq_quad or Sheet 2).The Quaternary deposits in Alameda County...
Alameda County is located at the northern end of the Diablo Range of Central California. It is bounded on the north by the south flank of Mount Diablo, one of the highest peaks in the Bay Area, reaching an elevation of 1173 meters (3,849 ft). San Francisco Bay forms the western boundary, the San Joaquin Valley borders it on the east and an arbitrary line from the Bay into the Diablo Range forms the southern boundary. Alameda is one of the nine Bay Area counties tributary to San Francisco Bay. Most of the country is mountainous with steep rugged topography. Alameda County is covered by twenty-eight 7.5' topographic Quadrangles which are shown on the index map (alq_quad or Sheet 2). The Quaternary deposits in Alameda...
Categories: Web Site;
Tags: 06001 = Alameda,
06013 = Contra Costa,
06075 = San Francisco,
06077 = San Joaquin,
06081 = San Mateo,
Map data that predict the varying likelihood of landsliding canhelp public agencies make informed decisions on land use andzoning. This map, prepared in a geographic information systemfrom a statistical model, estimates the relative likelihood oflocal slopes to fail by two processes common to an area ofdiverse geology, terrain, and land use centered on metropolitanOakland. The model combines the following spatial data: (1) 120bedrock and surficial geologic-map units, (2) ground slopecalculated from a 30-m digital elevation model, (3) an inventoryof 6,714 old landslide deposits (not distinguished by age or typeof movement and excluding debris flows), and (4) the locations of1,192 post-1970 landslides that damaged...
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...
This Open-File report is a digital geologic map database of the Alameda County, California.
This map describes the possible hazard from earthquake-inducedlandslides for the cities of Oakland and Piedmont, CA. Thehazard depicted by this map was modeled for a scenariocorresponding to an M=7.1 earthquake on the Hayward, CA fault.This scenario magnitude is associated with complete rupture ofthe northern and southern segments of the Hayward fault, an eventthat has an estimated return period of about 500 years. Themodeled hazard also corresponds to completely saturated ground-water conditions resulting from an extreme storm event or seriesof storm events. This combination of earthquake and ground-waterscenarios represents a particularly severe state of hazard forearthquake-induced landslides. For dry ground-water...
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.
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 themapped area. Together with the accompanying text file (oakmf.ps,oakmf.pdf, oakmf.txt), it provides current information on thegeologic structure and stratigraphy of the area covered. Thedatabase delineates map units that are identified by general ageand lithology following the stratigraphic nomenclature of the U.S.Geological Survey. The scale of the source maps limits the spatialresolution (scale) of the database to 1:24,000 or smaller.
This report presents a preliminary map and database ofQuaternary deposits and liquefaction susceptibility for thenine-county San Francisco Bay region, together with a digitalcompendium of ground effects associated with past earthquakesin the region. The report consists of (1) a spatial database offivedata layers (Quaternary deposits, quadrangle index, andthree ground effects layers) and two text layers (a labels andleaders layer for Quaternary deposits and for groundeffects), (2) two small-scale colored maps (Quaternary depositsand liquefaction susceptibility), (3) a text describing theQuaternary map, liquefaction interpretation, and the groundeffects compendium, and (4) the databse description pamphlet.The nine...
In this study, we develop a liquefaction susceptibility map of theSan Francisco 1:100,000 quadrangle using Quaternary geologicmapping, historical liquefaction information, groundwater data, andprevious studies.
This digital map database, compiled from previously open- filed U.S.Geological Survey reports (Graymer and others, 1994, Graymer,Jones, and Brabb, 1994) and unpublished data, represents thegeneral distribution of rocks and faults in the Hayward fault zone.As described in this report, the Hayward fault zone is a zone ofhighly deformed rocks which trends north 30 degrees west from anarea southeast of San Jose to the San Pablo Bay, and ranges inwidth from 2 to 10 kilometers. Although historic earthquakeactivity has been concentrated in the western part of the zone, thezone as a whole reflects oblique right-lateral and compressivedeformation along a significant upper crustal break over the past10 million years or more....
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