Description: This part of DS 781 presents data for the bathymetric contours for several seafloor maps of the Offshore Scott Creek map area, California. The vector data file is included in "Contours_OffshoreScottCreek.zip", which is accessible from http://dx.doi.org/10.5066/F7CJ8BJW.
10-m interval contours of the Offshore Scott Creek map area, California, were generated from bathymetry data collected by the U.S. Geological Survey (USGS) and by California State University, Monterey Bay (CSUMB). Mapping was completed between 2006 and 2009 using a combination of a 244-kHz Reson 8101 multibeam echosounder and a 234-kHz SEA SWATHplus bathymetric sidescan-sonar system. The mapping missions collected bathymetry data from about the 10-m isobath to beyond the 3-nautical-mile limit of California’s State Waters. Bathymetric contours at 10-m intervals were generated from a modified 2-m bathymetric surface. The original surface was smoothed using the Focal Mean tool in ArcGIS and a circular neighborhood with a radius of 20 to 30 meters (depending on the area). The contours were generated from this smoothed surface using the ArcGIS Spatial Analyst Contour tool. The most continuous contour segments were preserved while smaller segments and isolated island polygons were excluded from the final output. The contours were then clipped to the boundary of the map area.
Description: This part of DS 781 presents data for the faults for the geologic and geomorphic map of the Offshore of Scott Creek map area, California. The vector data file is included in "Faults_OffshoreScottCreek.zip," which is accessible from http://dx.doi.org/10.5066/F7CJ8BJW.
The offshore of Scott Creek map area straddles the right-lateral San Gregorio Fault Zone, an important structure in the distributed transform boundary between the North American and Pacific plates. Regionally, this fault is part of a system that occurs predominantly in the offshore for about 400 km from Point Conception in the south to Bolinas and Point Reyes in the north. The San Gregorio Fault in the map area is part of a 90-km-long offshore segment that extends from Point Sur on the south, across outer Monterey Bay to Point Ano Nuevo. Offshore parts of this fault system are identified on seismic-reflection data based on abrupt truncation or warping of reflections and (or) juxtaposition of reflection panels with different seismic parameters. In this map area, the San Gregorio Fault forms a distributed about 2-km-wide shear zone that includes two main faults. The nearshore eastern part of the zone, which includes the Coastways Fault, partly coincides with a prominent bathymetric lineament on the outer flank of nearshore bedrock outcrops between Waddell Creek and Davenport. The western part of the zone, which includes the Frijoles Fault, cuts across the flat, sediment-covered shelf. Cumulative lateral slip on San Gregorio Fault Zone in this region is thought to range from 4 to 10 mm/yr.
McCulloch (1987) considered the San Gregorio Fault Zone the eastern margin of the Outer Santa Cruz Basin. Farther offshore, outside California's State Waters but within the map area, this basin is cut by the northwest-trending Ascension Fault.
Description: This part of DS 781 presents data for the folds for the geologic and geomorphic map of the Offshore of Scott Creek map area, California. The vector data file is included in "Folds_OffshoreScottCreek.zip," which is accessible from http://dx.doi.org/10.5066/F7CJ8BJW.
The offshore of Scott Creek map area straddles the right-lateral San Gregorio Fault Zone, an important structure in the distributed transform boundary between the North American and Pacific plates. Regionally, this fault is part of a system that occurs predominantly in the offshore for about 400 km from Point Conception in the south to Bolinas and Point Reyes in the north. The San Gregorio Fault in the map area is part of a 90-km-long offshore segment that extends from Point Sur on the south, across outer Monterey Bay to Point Ano Nuevo. Offshore parts of this fault system are identified on seismic-reflection data based on abrupt truncation or warping of reflections and (or) juxtaposition of reflection panels with different seismic parameters. In this map area, the San Gregorio Fault forms a distributed about 2-km-wide shear zone that includes two main faults. The nearshore eastern part of the zone, which includes the Coastways Fault, partly coincides with a prominent bathymetric lineament on the outer flank of nearshore bedrock outcrops between Waddell Creek and Davenport. The western part of the zone, which includes the Frijoles Fault, cuts across the flat, sediment-covered shelf. Cumulative lateral slip on San Gregorio Fault Zone in this region is thought to range from 4 to 10 mm/yr.
McCulloch (1987) considered the San Gregorio Fault Zone the eastern margin of the Outer Santa Cruz Basin. Farther offshore, outside California's State Waters but within the map area, this basin is cut by the northwest-trending Ascension Fault.
Description: This part of DS 781 presents data for the geologic and geomorphic map of the Offshore of Scott Creek map area, California. The vector data file is included in "Geology_OffshoreScottCreek.zip," which is accessible from http://dx.doi.org/10.5066/F7CJ8BJW.
The offshore part of the map area lies southwest of the southwest flank of the Santa Cruz Mountains, extending from the shoreline to water depths of about 60 to 75 m on the gently dipping (about 0.6° to 0.8°) continental shelf. The shelf is underlain by Neogene bedrock and a variably thick (as much as 24 m) late Quaternary sediment cover. Sea level has risen 120 to 130 m over about the last 21,000 years, leading to broadening of the continental shelf, progressive eastward migration of the shoreline and wave-cut platform, and associated transgressive erosion and deposition. The Offshore of Scott Creek map area is now an open-ocean shelf that is subjected to full, and sometimes severe, wave energy. Shelf morphology and geology are also affected by local faulting, folding, uplift, and possibly subsidence.
The offshore of Scott Creek map area straddles the right-lateral San Gregorio Fault Zone, an important structure in the distributed transform boundary between the North American and Pacific plates. Regionally, this fault is part of a system that occurs predominantly in the offshore for about 400 km from Point Conception in the south to Bolinas and Point Reyes in the north. The San Gregorio Fault in the map area is part of a 90-km-long offshore segment that extends from Point Sur on the south, across outer Monterey Bay to Point Año Nuevo. Offshore parts of this fault system are identified on seismic-reflection data based on abrupt truncation or warping of reflections and (or) juxtaposition of reflection panels with different seismic parameters. In this map area, the San Gregorio Fault forms a distributed about 2-km-wide shear zone that includes two main faults. The nearshore eastern part of the zone, which includes the Coastways Fault, partly coincides with a prominent bathymetric lineament on the outer flank of nearshore bedrock outcrops between Waddell Creek and Davenport. The western part of the zone, which includes the Frijoles Fault, cuts across the flat, sediment-covered shelf. Cumulative lateral slip on San Gregorio Fault Zone in this region is thought to range from 4 to 10 mm/yr.
McCulloch (1987) considered the San Gregorio Fault Zone the eastern margin of the Outer Santa Cruz Basin. Farther offshore, outside California's State Waters but within the map area, this basin is cut by the northwest-trending Ascension Fault.
Emergent marine terraces on the flanks of the Santa Cruz Mountains between Santa Cruz and Point Año Nuevo are as high as 240 m with estimated uplift rates that range from about 0.2 m/year to as much as 1.1 mm/yr. This uplift has been attributed to a combination of (1) advection of crust around a bend in the San Andreas Fault, and (2) uplift on the northeast (landward) side of a steep-northeast dipping offshore San Gregorio fault. The uplifted region in this tectonic model includes the nearshore and shelf of the Offshore of Scott Creek map area, but considerable shore-normal uplift gradients are associated with both processes and offshore uplift rates are not well constrained.
Map unit polygons were digitized over underlying 2-meter base layers developed from multibeam bathymetry and backscatter data. The bathymetry and backscatter data were collected between 2006 and 2010.
Description: This part of DS 781 presents data for the habitat map of the seafloor of the Offshore of Scott Creek map area, California. The vector data file is included in "Habitat_OffshoreScottCreek.zip," which is accessible from http://dx.doi.org/10.5066/F7CJ8BJW.
Using multibeam echosounder (MBES) bathymetry and backscatter data, potential marine benthic habitat maps were constructed. The habitats were based on substrate types and documented or "ground truthed" using underwater video images and seafloor samples obtained by the USGS. These maps display various habitat types that range from flat, soft, unconsolidated sediment-covered seafloor to hard, deformed (folded), or highly rugose and differentially eroded bedrock exposures. Rugged, high-relief, rocky outcrops that have been eroded to form ledges and small caves are ideal habitat for rockfish (Sebastes spp.) and other bottom fish such as lingcod (Ophiodon elongatus).
Please refer to Greene and others (2007) for more information regarding the Benthic Marine Potential Habitat Classification Scheme and the codes used to represent various seafloor features.
Description: This part of DS 781 presents the seafloor-character map Offshore of Scott Creek, California. The raster data file is included in "SeafloorCharacter_OffshoreScottCreek.zip," which is accessible from http://dx.doi.org/10.5066/F7CJ8BJW.
This raster-format seafloor character map shows four substrate classes offshore of Scott Creek, California. The substrate classes mapped in this area have been further divided into the following California Marine Life Protection Act depth zones and slope classes: Depth Zone 2 (intertidal to 30 m), Depth Zone 3 (30 to 100 m), Slope Class 1 (0 degrees - 5 degrees), and Slope Class 2 (5 degrees - 30 degrees). Depth Zone 1 (intertidal), Depth Zones 4-5 (greater than 100 m), and Slopes Classes 3-4 (greater than 30 degrees) are not present in the region covered by this block. The map is created using a supervised classification method described by Cochrane (2008), available at http://doc.nprb.org/web/research/research%20pubs/615_habitat_mapping_workshop/Individual%20Chapters%20High-Res/Ch13%20Cochrane.pdf.
Description: This part of DS 781 presents data for the bathymetry and shaded-relief maps of Offshore Scott Creek, California. The raster data file is included in "BathymetryHS_OffshoreScottCreek.zip", which is accessible from http://dx.doi.org/10.5066/F7CJ8BJW.
The bathymetry and shaded-relief maps of Offshore Scott Creek, California, were generated from bathymetry data collected by California State University, Monterey Bay (CSUMB), by Fugro Pelagos, and by the U.S. Geological Survey (USGS). Mapping was completed between 2006 and 2009, using a combination of 400-kHz Reson 7125 and 244-kHz Reson 8101 multibeam echosounders, as well as a 234-kHz SWATHplus bathymetric sidescan-sonar system. These mapping missions combined to collect bathymetry from about the 10-m isobath to beyond the 3-nautical-mile limit of California’s State Waters.
Description: This part of DS 781 presents data for the acoustic-backscatter map of Offshore of Scott Creek map area, California. Backscatter data are provided as three separate grids depending on mapping system. The raster data files are included in "BackscatterA_8101_OffshoreScottCreek.zip," which is accessible from http://dx.doi.org/10.5066/F7CJ8BJW.
The acoustic-backscatter map of the Offshore of Scott Creek, California was generated from backscatter data collected by California State University, Monterey Bay (CSUMB), by Fugro Pelagos, and by the U.S. Geological Survey (USGS). Mapping was completed between 2006 and 2009, using a combination of 400-kHz Reson 7125 and 244-kHz Reson 8101 multibeam echosounders, as well as a 234-kHz SWATHplus bathymetric sidescan-sonar system. Within the final imagery, brighter tones indicate higher backscatter intensity, and darker tones indicate lower backscatter intensity. The intensity represents a complex interaction between the acoustic pulse and the seafloor, as well as characteristics within the shallow subsurface, providing a general indication of seafloor texture and composition. Backscatter intensity depends on the acoustic source level; the frequency used to image the seafloor; the grazing angle; the composition and character of the seafloor, including grain size, water content, bulk density, and seafloor roughness; and some biological cover. Harder and rougher bottom types such as rocky outcrops or coarse sediment typically return stronger intensities (high backscatter, lighter tones), whereas softer bottom types such as fine sediment return weaker intensities (low backscatter, darker tones).
Description: This part of DS 781 presents data for the acoustic-backscatter map of Offshore of Scott Creek map area, California. Backscatter data are provided as three separate grids depending on mapping system. The raster data files are included in "BackscatterB_7125_OffshoreScottCreek.zip," which is accessible from http://dx.doi.org/10.5066/F7CJ8BJW.
The acoustic-backscatter map of the Offshore of Scott Creek, California was generated from backscatter data collected by California State University, Monterey Bay (CSUMB), by Fugro Pelagos, and by the U.S. Geological Survey (USGS). Mapping was completed between 2006 and 2009, using a combination of 400-kHz Reson 7125 and 244-kHz Reson 8101 multibeam echosounders, as well as a 234-kHz SWATHplus bathymetric sidescan-sonar system. Within the final imagery, brighter tones indicate higher backscatter intensity, and darker tones indicate lower backscatter intensity. The intensity represents a complex interaction between the acoustic pulse and the seafloor, as well as characteristics within the shallow subsurface, providing a general indication of seafloor texture and composition. Backscatter intensity depends on the acoustic source level; the frequency used to image the seafloor; the grazing angle; the composition and character of the seafloor, including grain size, water content, bulk density, and seafloor roughness; and some biological cover. Harder and rougher bottom types such as rocky outcrops or coarse sediment typically return stronger intensities (high backscatter, lighter tones), whereas softer bottom types such as fine sediment return weaker intensities (low backscatter, darker tones).
Description: This part of DS 781 presents data for the acoustic-backscatter map of Offshore of Scott Creek map area, California. Backscatter data are provided as three separate grids depending on mapping system. The raster data files are included in "BackscatterC_SWATH_OffshoreScottCreek.zip," which is accessible from http://dx.doi.org/10.5066/F7CJ8BJW.
The acoustic-backscatter map of the Offshore of Scott Creek, California was generated from backscatter data collected by California State University, Monterey Bay (CSUMB), by Fugro Pelagos, and by the U.S. Geological Survey (USGS). Mapping was completed between 2006 and 2009, using a combination of 400-kHz Reson 7125 and 244-kHz Reson 8101 multibeam echosounders, as well as a 234-kHz SWATHplus bathymetric sidescan-sonar system. Within the final imagery, brighter tones indicate higher backscatter intensity, and darker tones indicate lower backscatter intensity. The intensity represents a complex interaction between the acoustic pulse and the seafloor, as well as characteristics within the shallow subsurface, providing a general indication of seafloor texture and composition. Backscatter intensity depends on the acoustic source level; the frequency used to image the seafloor; the grazing angle; the composition and character of the seafloor, including grain size, water content, bulk density, and seafloor roughness; and some biological cover. Harder and rougher bottom types such as rocky outcrops or coarse sediment typically return stronger intensities (high backscatter, lighter tones), whereas softer bottom types such as fine sediment return weaker intensities (low backscatter, darker tones).
Description: This part of DS 781 presents data for the bathymetry and shaded-relief maps of Offshore Scott Creek, California. The raster data file is included in "Bathymetry_OffshoreScottCreek.zip", which is accessible from http://dx.doi.org/10.5066/F7CJ8BJW.
The bathymetry and shaded-relief maps of Offshore Scott Creek, California, were generated from bathymetry data collected by California State University, Monterey Bay (CSUMB), by Fugro Pelagos, and by the U.S. Geological Survey (USGS). Mapping was completed between 2006 and 2009, using a combination of 400-kHz Reson 7125 and 244-kHz Reson 8101 multibeam echosounders, as well as a 234-kHz SWATHplus bathymetric sidescan-sonar system. These mapping missions combined to collect bathymetry from about the 10-m isobath to beyond the 3-nautical-mile limit of California’s State Waters.