Description: This part of SIM 3302 presents bathymetric contours for several seafloor maps of Offshore Coal Oil Point, California (vector data file is included in "Contours_OffshoreCoalOilPoint.zip," which is accessible from http://pubs.usgs.gov/ds/781/OffshoreCoalOilPoint/data_catalog_OffshoreCoalOilPoint.html). Contours of Offshore Coal Oil Point, California, were generated from bathymetry data collected by the U.S. Geological Survey (USGS), by California State University, Monterey Bay, Seafloor Mapping Lab (CSUMB), and by Fugro Pelagos. Most of the nearshore and shelf regions were mapped by the USGS in the summers of 2006, 2007, and 2008 using a combination of 117 kHz and 234.5 kHz SEA (AP) Ltd. SWATHplus-M phase-differencing sidescan sonars. The far eastern nearshore and shelf regions were mapped by CSUMB in the summer of 2007 using a 244 kHz Reson 8101 multibeam echosounder. The outer shelf and slope regions were mapped by Fugro Pelagos in 2008 using a combination of 400 kHz Reson 7125, 240 kHz Reson 8101, and 100 kHz Reson 8111 multibeam echosounders. The nearshore bathymetry and coastal topography were also mapped by Fugro Pelagos in 2009 for the U.S. Army Corps of Engineers (USACE) Joint Lidar Bathymetry Technical Center of Expertise using the SHOALS-1000T bathymetric and the Leica ALS60 topographic lidar systems. All of these mapping missions combined to collect bathymetry from the 0-m isobath to beyond the 3-nautical mile limit of California’s state waters. A smooth arithmetic mean convolution function applying a weight of 1/9 to each cell in a 3x3 matrix was applied iteratively to the merged bathymetry grid ten times. Following smoothing, contour lines were generated at 10-meter intervals from 10 to 100 m and 50-meter intervals from 100 to 250 m.
Description: This part of SIM 3302 presents data for faults for the geologic and geomorphic map (see sheet 10, SIM 3302) of the Offshore of Coal Oil Point map area, California. The vector data file is included in "Faults_OffshoreCoalOilPoint.zip," which is accessible from http://pubs.usgs.gov/ds/781/OffshoreCoalOilPoint/data_catalog_OffshoreCoalOilPoint.html. This map area is in the Ventura Basin, in the southern part of the Western Transverse Ranges geologic province, which is north of the California Continental Borderland (Fisher and others, 2009). Significant clockwise rotation--at least 90 degrees--since the early Miocene has been proposed for the Western Transverse Ranges province (Luyendyk and others, 1980; Hornafius and others, 1986; Nicholson and others, 1994), and this region is presently undergoing north-south shortening (see, for example, Larson and Webb, 1992). In the eastern part of the map area, cross sections suggest that this shortening is, in part, accommodated by offset on the North Channel, Red Mountain, South Ellwood, and More Creek Fault systems (Bartlett, 1998; Heck, 1998; Redin and others, 2005; Leifer and others, 2010). Crustal deformation in the western part of the Offshore of Coal Oil Point map area apparently is less complex than that in the eastern part (Redin, 2005); the western structure is dominated by a large, south-dipping homocline that extends from the south flank of the Santa Ynez Mountains beneath the continental shelf.
Description: This part of SIM 3302 presents data for folds for the geologic and geomorphic map (see sheet 10, SIM 3302) of the Offshore of Coal Oil Point map area, California. The vector data file is included in "Folds_OffshoreCoalOilPoint.zip," which is accessible from http://pubs.usgs.gov/ds/781/OffshoreCoalOilPoint/data_catalog_OffshoreCoalOilPoint.html. This map area is in the Ventura Basin, in the southern part of the Western Transverse Ranges geologic province, which is north of the California Continental Borderland (Fisher and others, 2009). Significant clockwise rotation--at least 90 degrees--since the Miocene has been proposed for the Western Transverse Ranges province (Luyendyk and others, 1980; Hornafius and others, 1986; Nicholson and others, 1994), and this region is presently undergoing north-south shortening (see, for example, Larson and Webb, 1992). In the eastern part of the map area, cross sections suggest that this shortening is, in part, accommodated by offset on the North Channel, Red Mountain, South Ellwood, and More Creek Fault systems (Bartlett, 1998; Heck, 1998; Redin and others, 2005; Leifer and others, 2010). Crustal deformation in the western part of the Offshore of Coal Oil Point map area apparently is less complex than that in the eastern part (Redin, 2005); the western structure is dominated by a large, south-dipping homocline that extends from the south flank of the Santa Ynez Mountains beneath the continental shelf.
Description: This part of SIM 3302 presents data for the geologic and geomorphic map (see sheet 10, SIM 3302) of the Offshore of Coal Oil Point map area, California. The vector data file is included in "Geology_OffshoreCoalOilPoint.zip," which is accessible from http://pubs.usgs.gov/ds/781/OffshoreCoalOilPoint/data_catalog_OffshoreCoalOilPoint.html. The offshore part of the Offshore of Coal Oil Point map area largely consists of a gently offshore-dipping (less than 1 degree) shelf underlain by sediments derived primarily from relatively small coastal watersheds that drain the Santa Ynez Mountains. Shelf deposits are primarily sand (Qms) at depths less than about 35 to 50 m, and they are finer grained sediment such as very fine sand, silt, and clay (Qmsf) from depths of 35 to 50 m southward to the shelf break at a depth of about 90 m. The boundary between units Qms and Qmsf is based on observations and extrapolation from sediment sampling (see, for example, Reid and others, 2006) and camera ground-truth surveying. It is important to note that the boundary between units Qms and Qmsf should be considered transitional and approximate and is expected to shift as a result of seasonal- to annual- to decadal-scale cycles in wave climate, sediment supply, and sediment transport. Fine-grained deposits that are similar to unit Qmsf also are mapped at water depths greater than 90 m, below the shelf break on the upper slope; however, here they are identified as a separate unit (unit Qmsl) because of their location below the distinct shelf-slope geomorphologic break. Coarser grained, marine deposits (coarse sand to boulders) of units Qmsc, Qmscl, and Qsc are recognized on the basis of their high acoustic backscatter, their ground-truth-survey imagery, and, in some cases, their moderate seafloor relief. This coarse-grained facies is linked either to the mouths of steep coastal watersheds or to adjacent seafloor bedrock outcrops, and the deposits generally represent wave-winnowed lags of deltaic sediment. Two distinct lobes of coarse-grained sediment (unit Qmscl), present in deeper water (about 50 m) near the west edge of the map area, may similarly represent winnowed deltaic deposits that formed at lower sea levels during the latest Pleistocene or early Holocene. An isolated patch of clast-supported cobbles (unit Qsc), which rests on bedrock south of Coal Oil Point at a water depth of 70 m, also may have been deposited at lower sea levels during the late Pleistocene. Offshore bedrock exposures are mapped as either the Miocene Monterey Formation (Tm, Tmu, Tmm), the late Miocene and early Pliocene Sisquoc Formation (Tsq), or the undivided Quaternary and Tertiary bedrock (QTbu) or undivided Tertiary bedrock (Tbu) units on the basis of the confidence in extending the onshore mapping of Minor and others (2009) offshore. Midshelf to outer shelf bedrock exposures are all mapped as undivided units; however, offshore sampling data (see, for example, Kunitomi and others, 1998), as well as regional cross sections that are constrained by petroleum exploration data and sampling (Redin, 2005; Redin and others, 2005), have suggested that these seafloor outcrops predominantly are late Miocene and Pliocene strata. These rocks have been uplifted in a large, regional, internally warped, south-dipping homocline that formed above the blind, north-dipping Pitas Point-North Channel Fault system; the fault tip is inferred to lie beneath the continental slope, about 6 to 7 km offshore. Bedrock is, in some places, overlain by a thin (less than 1 m?) veneer of sediment, recognized on the basis of high backscatter, flat relief, continuity with moderate- to high-relief bedrock outcrops, and (in some cases) high-resolution seismic-reflection data; these areas, which are mapped as composite units Qms/Tu, Qms/Tsq, Qms/Tmu, Qms/Tmm, Qms/Tm, Qms/Tbu, or Qmsf/QTbu, are interpreted as ephemeral sediment layers that may or may not be continuously present, whose presence or absence is a function of the recency and intensity of storm events, seasonal and (or) annual patterns of sediment movement, or longer term climate cycles. The Offshore of Coal Oil Point map area includes the upper part of the large (130 km2), well-documented submarine Goleta landslide complex (Eichhubl and others, 2002; Fisher and others, 2005; Greene and others, 2006). Greene and others (2006) reported that the complex, which measures 14.6 km long and 10.5 km wide and extends from water depths of 90 to 574 m, has displaced about 1.75 km3 of landslide debris during the Holocene; they described it as a compound, multiphase submarine landslide that contains both surficial slump blocks and mud flows, in three distinct segments (west, central, and east lobes). Each segment consists of a distinct headwall scarp (units Qglwh, Qglch, Qgleh), a downdropped head block (units Qglwb, Qglcb, Qgleb), and several composite slide-debris lobes (units Qglw5, Qfglw4, Qglw3, Qglw2, Qglw1, Qglc4, Qglc3, Qglc2a, Qglc2, Qfle5, Qgle4, Qgle3, Qgle2). The geologic map geomorphic map on sheet 10 (SIM 3302) shows the upper approximately 3 km of this landslide complex; in addition, the seismic-reflection profile SB-145 (fig. 3 on sheet 8, SIM 3302), which crosses the east lobe of the landslide complex, illustrates its subsurface characteristics. The landslide source is inferred to be Pleistocene-age, shelf-edge deltaic sediments deposited during Quaternary sea-level lowstands, and Fisher and others (2005) suggested that the youngest landslides formed about 8,000 to 10,000 years ago. The Santa Barbara Channel region, including the map area, has a long history of petroleum production (Barnum, 1998) that began in 1928 with discovery of the Ellwood oil field. Subsequent discoveries in the offshore part of the map area include the South Ellwood offshore oil field, the Coal Oil Point oil field, and the Naples oil and gas field (Brickey, 1998; Galloway, 1998). Oil and gas are mainly sourced by the Miocene Monterey Formation; the reservoirs are in the Vaqueros Formation, the Rincon Shale, and the Monterey Formation. Development of the South Ellwood offshore oil field began in 1966 from platform "Holly," which was the last platform to be installed in California's State Waters. Debris and infrastructure associated with platform "Holly," as well as with seep containment devices ("seep tents"), are mapped as unit pd. Hornafius and others (1999) described "the world's most spectacular marine hydrocarbon seeps" in the Coal Oil Point map area, and these seeps release an estimated 36 metric tons of methane and 17 metric tons reactive organic gas (ethane, propane, butane, and higher hydrocarbons) per day. Areas of grouped to solitary pockmarks (unit Qmp) caused by gas seeps are common features. In addition, numerous asphalt (tar) deposits (unit Qas) associated with hydrocarbon seeps and gas vents are mapped both onshore and offshore. The offshore deposits, which have been confirmed with seafloor video observations, often are localized along bedrock structures such as faults or the crests of anticlines, forming bathymetric features that are morphologically similar to bedrock outcrops but are distinguished from them on the basis of their low acoustic backscatter. Although many such asphalt deposits are too small to be shown on the map, the larger deposits can cover as much as several hundred square meters.
Description: This part of SIM 3302 presents the habitat map of the seafloor (see sheet 7) of Offshore of Coal Oil Point, California (vector data file is included in "Habitat_OffshoreCoalOilPoint.zip," which is accessible from http://pubs.usgs.gov/ds/781/OffshoreCoalOilPoint/data_catalog_OffshoreCoalOilPoint.html). 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 ranging from flat, soft consolidated 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). Habitat maps will be presented in a map format generated in a GIS (ArcMap) and both digital and hard copy versions will be produced.
Description: This part of SIM 3302 presents data for the seafloor-character map (see sheet 5, SIM 3302) of the Offshore of Coal Oil Point map area, California. The raster data file is included in "SeafloorCharacter_OffshoreCoalOilPoint_2m.zip," which is accessible from http://pubs.usgs.gov/ds/781/OffshoreCoalOilPoint/data_catalog_OffshoreCoalOilPoint.html. These metadata describe the seafloor-character data collected at 2-m resolution. See "SeafloorCharacter_OffshoreCoalOilPoint_5m_metadata.txt" metadata for a description of the seafloor-character data collected at 5-m resolution. The raster-format seafloor-character map shows five substrate classes of the Offshore of Coal Oil Point map area. The substrate classes mapped in this map area have been colored to indicate in which of the following California Marine Life Protection Act depth zones and slope classes they belong: Depth Zone 2 (intertidal to 30 m), Depth Zone 3 (30 to 100 m), Depth Zone 4 (100 to 200 m), Slope Class 1, 0 degrees to 5 degrees (flat), Slope Class 2, 5 degrees to 30 degrees (sloping), and Slope Class 3, 30 degrees to 60 degrees (steeply sloping). Depth Zone 1 (intertidal), Depth Zone 5 (greater than 200 m), and Slope Classes 4 and 5, greater than 60 degrees (vertical to overhang) are not present in this map area. 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. Bathymetry data were collected at two different resolutions: at 2-m resolution, down to approximately 80-m water depth (2006-2008 USGS data, and 2007 CSUMB data); and at 5-m resolution, in the deeper areas (2009 Fugro Pelagos data). The final resolution of the seafloor-character map is determined by the resolution of both the backscatter and bathymetry datasets; therefore, separate seafloor-character maps were generated to retain the maximum resolution of the source data.
Description: This part of SIM 3302 presents data for the seafloor-character map (see sheet 5, SIM 3302) of the Offshore of Coal Oil Point map area, California. The raster data file is included in "SeafloorCharacter_OffshoreCoalOilPoint_5m.zip," which is accessible from http://pubs.usgs.gov/ds/781/OffshoreCoalOilPoint/data_catalog_OffshoreCoalOilPoint.html. These metadata describe the seafloor-character data collected at 5-m resolution. See "SeafloorCharacter_OffshoreCoalOilPoint_2m_metadata.txt" metadata for a description of the seafloor-character data collected at 2-m resolution. The raster-format seafloor-character map shows five substrate classes of the Offshore of Coal Oil Point map area. The substrate classes mapped in this map area have been colored to indicate in which of the following California Marine Life Protection Act depth zones and slope classes they belong: Depth Zone 2 (intertidal to 30 m), Depth Zone 3 (30 to 100 m), Depth Zone 4 (100 to 200 m), Slope Class 1, 0 degrees to 5 degrees (flat), Slope Class 2, 5 degrees to 0 degrees (sloping), and Slope Class 3, 30 degrees to 60 degrees (steeply sloping). Depth Zone 1 (intertidal), Depth Zone 5 (greater than 200 m), and Slope Classes 4 and 5, greater than 60 degrees (vertical to overhang) are not present in this map area. 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. Bathymetry data were collected at two different resolutions: at 2-m resolution, down to approximately 80-m water depth (2006-2008 USGS data, and 2007 CSUMB data); and at 5-m resolution, in the deeper areas (2009 Fugro Pelagos data). The final resolution of the seafloor-character map is determined by the resolution of both the backscatter and bathymetry datasets; therefore, separate seafloor-character maps were generated to retain the maximum resolution of the source data.
Description: This part of SIM 3302 presents data for the bathymetry and shaded-relief maps (see sheets 1, 2, SIM 3302) of the Offshore of Coal Oil Point map area, California. The raster data file for the bathymetry map is included in "Bathymetry_OffshoreCoalOilPoint.zip." The raster data file for the shaded-relief map is included in "BathymetryHS_OffshoreCoalOilPoint.zip." Both are accessible from http://pubs.usgs.gov/ds/781/OffshoreCoalOilPoint/data_catalog_OffshoreCoalOilPoint.html. The bathymetry and shaded-relief maps of the Offshore of Coal Oil Point map area, California, were generated from bathymetry data collected by the U.S. Geological Survey (USGS), by California State University, Monterey Bay, Seafloor Mapping Lab (CSUMB), and by Fugro Pelagos. Most of the nearshore and shelf areas were mapped by the USGS in the summers of 2006, 2007, and 2008, using a combination of 117-kHz and 234.5-kHz SEA (AP) Ltd. SWATHplus-M phase-differencing sidescan sonars. A small area in the far-eastern nearshore and shelf was mapped by CSUMB in the summer of 2007, using a 244-kHz Reson 8101 multibeam echosounder. The outer shelf and slope were mapped by Fugro Pelagos in 2008, using a combination of 400-kHz Reson 7125, 240-kHz Reson 8101, and 100-kHz Reson 8111 multibeam echosounders. The nearshore bathymetry and coastal topography were also mapped by Fugro Pelagos in 2009 for the U.S. Army Corps of Engineers (USACE) Joint Lidar Bathymetry Technical Center of Expertise, using the SHOALS-1000T bathymetric-lidar and the Leica ALS60 topographic-lidar systems. All of these mapping missions combined to collect bathymetry from the 0-m isobath to beyond the 3-nautical-mile limit of California's State Waters.
Description: This part of SIM 3302 presents data for the bathymetry and shaded-relief maps (see sheets 1, 2, SIM 3302) of the Offshore of Coal Oil Point map area, California. The raster data file for the bathymetry map is included in "Bathymetry_OffshoreCoalOilPoint.zip." The raster data file for the shaded-relief map is included in "BathymetryHS_OffshoreCoalOilPoint.zip." Both are accessible from http://pubs.usgs.gov/ds/781/OffshoreCoalOilPoint/data_catalog_OffshoreCoalOilPoint.html. The bathymetry and shaded-relief maps of the Offshore of Coal Oil Point map area, California, were generated from bathymetry data collected by the U.S. Geological Survey (USGS), by California State University, Monterey Bay, Seafloor Mapping Lab (CSUMB), and by Fugro Pelagos. Most of the nearshore and shelf areas were mapped by the USGS in the summers of 2006, 2007, and 2008, using a combination of 117-kHz and 234.5-kHz SEA (AP) Ltd. SWATHplus-M phase-differencing sidescan sonars. A small area in the far-eastern nearshore and shelf was mapped by CSUMB in the summer of 2007, using a 244-kHz Reson 8101 multibeam echosounder. The outer shelf and slope were mapped by Fugro Pelagos in 2008, using a combination of 400-kHz Reson 7125, 240-kHz Reson 8101, and 100-kHz Reson 8111 multibeam echosounders. The nearshore bathymetry and coastal topography were also mapped by Fugro Pelagos in 2009 for the U.S. Army Corps of Engineers (USACE) Joint Lidar Bathymetry Technical Center of Expertise, using the SHOALS-1000T bathymetric-lidar and the Leica ALS60 topographic-lidar systems. All of these mapping missions combined to collect bathymetry from the 0-m isobath to beyond the 3-nautical-mile limit of California's State Waters.
Description: This part of SIM 3302 presents data for part of the acoustic-backscatter map (see sheet 3, SIM 3302) of the Offshore of Coal Oil Point map area, California. The raster data file is included in "BackscatterA_CSUMB_OffshoreCoalOilPoint.zip," which is accessible from http://pubs.usgs.gov/ds/781/OffshoreCoalOilPoint/data_catalog_OffshoreCoalOilPoint.html. The acoustic-backscatter map of Offshore Coal Oil Point, California was generated from backscatter data collected by California State University, Monterey Bay, Seafloor Mapping Lab (CSUMB), by the U.S. Geological Survey (USGS) and by Fugro Pelagos. These metadata describe the acoustic-backscatter data collected by CSUMB and reprocessed by the USGS. See "BackscatterB_USGS_OffshoreCoalOilPt_metadata.txt" metadata for a description of the acoustic-backscatter data collected by the USGS. The far eastern nearshore and shelf region of the Offshore Coal Oil Point map was mapped by CSUMB in the summer of 2007 using a 244 kHz Reson 8101 multibeam echosounder. 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 sediment type. 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 SIM 3302 presents data for part of the acoustic-backscatter map (see sheet 3, SIM 3302) of the Offshore of Coal Oil Point map area, California. The raster data file is included in "BackscatterB_USGS_OffshoreCoalOilPoint.zip," which is accessible from http://pubs.usgs.gov/ds/781/OffshoreCoalOilPoint/data_catalog_OffshoreCoalOilPoint.html. The acoustic-backscatter map of the Offshore of Coal Oil Point map area, California, was generated from backscatter data collected by California State University, Monterey Bay, Seafloor Mapping Lab (CSUMB), by the U.S. Geological Survey (USGS), and by Fugro Pelagos. These metadata describe the acoustic-backscatter data collected by the USGS. See "BackscatterA_CSUMB_OffshoreCoalOilPoint_metadata.txt" metadata for a description of the acoustic-backscatter data collected by CSUMB, and see "BackscatterC_Fugro_OffshoreCoalOilPoint_metadata.txt" metadata for a description of the acoustic-backscatter data collected by Fugro Pelagos. Most of the nearshore and shelf areas in the Offshore of Coal Oil Point map area were mapped by the USGS in the summers of 2006, 2007, and 2008, using a combination of 117-kHz and 234.5-kHz SEA (AP) Ltd. SWATHplus-M phase-differencing sidescan sonars. Within the acoustic-backscatter 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 sediment type. 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 SIM 3302 presents data for part of the acoustic-backscatter map (see sheet 3, SIM 3302) of the Offshore of Coal Oil Point map area, California. The raster data file is included in "BackscatterB_USGS_OffshoreCoalOilPoint.zip," which is accessible from http://pubs.usgs.gov/ds/781/OffshoreCoalOilPoint/data_catalog_OffshoreCoalOilPoint.html. The acoustic-backscatter map of the Offshore of Coal Oil Point map area, California, was generated from backscatter data collected by California State University, Monterey Bay, Seafloor Mapping Lab (CSUMB), by the U.S. Geological Survey (USGS), and by Fugro Pelagos. These metadata describe the acoustic-backscatter data collected by the USGS. See "BackscatterA_CSUMB_OffshoreCoalOilPoint_metadata.txt" metadata for a description of the acoustic-backscatter data collected by CSUMB, and see "BackscatterC_Fugro_OffshoreCoalOilPoint_metadata.txt" metadata for a description of the acoustic-backscatter data collected by Fugro Pelagos. Most of the nearshore and shelf areas in the Offshore of Coal Oil Point map area were mapped by the USGS in the summers of 2006, 2007, and 2008, using a combination of 117-kHz and 234.5-kHz SEA (AP) Ltd. SWATHplus-M phase-differencing sidescan sonars. Within the acoustic-backscatter 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 sediment type. 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 SIM 3302 presents data for part of the acoustic-backscatter map (see sheet 3, SIM 3302) of the Offshore of Coal Oil Point map area, California. The raster data file is included in "BackscatterC_Fugro_OffshoreCoalOilPoint.zip," which is accessible from http://pubs.usgs.gov/ds/781/OffshoreCoalOilPoint/data_catalog_OffshoreCoalOilPoint.html. The acoustic-backscatter map of the Offshore of Coal Oil Point map area, California, was generated from backscatter data collected by California State University, Monterey Bay, Seafloor Mapping Lab (CSUMB), by the U.S. Geological Survey (USGS), and by Fugro Pelagos. These metadata describe the acoustic-backscatter data collected by Fugro Pelagos and reprocessed by CSUMB. See "BackscatterA_CSUMB_OffshoreCoalOilPoint_metadata.txt" metadata for a description of the acoustic-backscatter data collected by CSUMB, and see "BackscatterB_USGS_OffshoreCoalOilPoint_metadata.txt" metadata for a description of the acoustic-backscatter data collected by the USGS. Fugro Pelagos collected backscatter data offshore the Coal Oil Point region (part of a larger Southern California mapping effort) using a combination of several sonars (400-kHz Reson 7125, 240-kHz Reson 8101, 100-kHz Reson 8111) aboard a series of Fugro Pelagos-directed vessels. An Applanix POS MV (Position and Orientation System for Marine Vessels) was used to accurately position the vessels during data collection, and it also accounted for vessel motion such as heave, pitch, and roll (position accuracy, +/-2 m; pitch, roll, and heading accuracy, +/-0.02 degrees; heave accuracy, +/-5 percent, or 5 cm). KGPS (GPS with real-time kinematic corrections) altitude data were used to account for tide-cycle fluctuations, and sound-velocity profiles were collected with an Applied Microsystems SVPlus sound velocimeter. Data were cleaned, and final products were created by the Seafloor Mapping Lab at CSUMB from the postprocessed multibeam-bathymetry data. Within the acoustic-backscatter 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 sediment type. 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 SIM 3302 presents data for the bathymetry and shaded-relief maps (see sheets 1, 2, SIM 3302) of the Offshore of Coal Oil Point map area, California. The raster data file for the bathymetry map is included in "Bathymetry_OffshoreCoalOilPoint.zip." The raster data file for the shaded-relief map is included in "BathymetryHS_OffshoreCoalOilPoint.zip." Both are accessible from http://pubs.usgs.gov/ds/781/OffshoreCoalOilPoint/data_catalog_OffshoreCoalOilPoint.html. The bathymetry and shaded-relief maps of the Offshore of Coal Oil Point map area, California, were generated from bathymetry data collected by the U.S. Geological Survey (USGS), by California State University, Monterey Bay, Seafloor Mapping Lab (CSUMB), and by Fugro Pelagos. Most of the nearshore and shelf areas were mapped by the USGS in the summers of 2006, 2007, and 2008, using a combination of 117-kHz and 234.5-kHz SEA (AP) Ltd. SWATHplus-M phase-differencing sidescan sonars. A small area in the far-eastern nearshore and shelf was mapped by CSUMB in the summer of 2007, using a 244-kHz Reson 8101 multibeam echosounder. The outer shelf and slope were mapped by Fugro Pelagos in 2008, using a combination of 400-kHz Reson 7125, 240-kHz Reson 8101, and 100-kHz Reson 8111 multibeam echosounders. The nearshore bathymetry and coastal topography were also mapped by Fugro Pelagos in 2009 for the U.S. Army Corps of Engineers (USACE) Joint Lidar Bathymetry Technical Center of Expertise, using the SHOALS-1000T bathymetric-lidar and the Leica ALS60 topographic-lidar systems. All of these mapping missions combined to collect bathymetry from the 0-m isobath to beyond the 3-nautical-mile limit of California's State Waters.
Description: This part of SIM 3302 presents data for the bathymetry and shaded-relief maps (see sheets 1, 2, SIM 3302) of the Offshore of Coal Oil Point map area, California. The raster data file for the bathymetry map is included in "Bathymetry_OffshoreCoalOilPoint.zip." The raster data file for the shaded-relief map is included in "BathymetryHS_OffshoreCoalOilPoint.zip." Both are accessible from http://pubs.usgs.gov/ds/781/OffshoreCoalOilPoint/data_catalog_OffshoreCoalOilPoint.html. The bathymetry and shaded-relief maps of the Offshore of Coal Oil Point map area, California, were generated from bathymetry data collected by the U.S. Geological Survey (USGS), by California State University, Monterey Bay, Seafloor Mapping Lab (CSUMB), and by Fugro Pelagos. Most of the nearshore and shelf areas were mapped by the USGS in the summers of 2006, 2007, and 2008, using a combination of 117-kHz and 234.5-kHz SEA (AP) Ltd. SWATHplus-M phase-differencing sidescan sonars. A small area in the far-eastern nearshore and shelf was mapped by CSUMB in the summer of 2007, using a 244-kHz Reson 8101 multibeam echosounder. The outer shelf and slope were mapped by Fugro Pelagos in 2008, using a combination of 400-kHz Reson 7125, 240-kHz Reson 8101, and 100-kHz Reson 8111 multibeam echosounders. The nearshore bathymetry and coastal topography were also mapped by Fugro Pelagos in 2009 for the U.S. Army Corps of Engineers (USACE) Joint Lidar Bathymetry Technical Center of Expertise, using the SHOALS-1000T bathymetric-lidar and the Leica ALS60 topographic-lidar systems. All of these mapping missions combined to collect bathymetry from the 0-m isobath to beyond the 3-nautical-mile limit of California's State Waters.