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Sample records for barbara california usa

  1. Soils and vegetation of Santa Barbara Island, Channel Islands National Park, California, USA

    NASA Astrophysics Data System (ADS)

    Halvorson, William L.; Fenn, Dennis B.; Allardice, William R.

    1988-01-01

    The multifaceted development of an erosion surface on Santa Barbara Island, Channel Islands National Park, California, has led to this study of the relationship between soils and vegetation. A dry Mediterranean climate and past attempts at farming and introductions of alien species have led to vegetative degradation accompanied by both gully and surface erosion. Soil and vegetation analyses show this erosion to be in a location of transition. The soils are Typic Chromoxererts (Vertisol Order) with high clay, salinity, and sodium contents. The vegetation is ecotonal in nature, grading from a principally alien annual grassland with Avena fatua and Atriplex semibaccata to a shrub community dominated by the native Suaeda californica. Management toward revegetation and stabilization of this island ecosystem will be difficult with high clay, saline-sodic soils and disturbed vegetation.

  2. California State Waters Map Series: offshore of Santa Barbara, California

    USGS Publications Warehouse

    Johnson, Samuel Y.; Dartnell, Peter; Cochrane, Guy R.; Golden, Nadine E.; Phillips, Eleyne L.; Ritchie, Andrew C.; Greene, H. Gary; Krigsman, Lisa M.; Kvitek, Rikk G.; Dieter, Bryan E.; Endris, Charles A.; Seitz, Gordon G.; Sliter, Ray W.; Erdey, Mercedes D.; Gutierrez, Carlos I.; Wong, Florence L.; Yoklavich, Mary M.; Draut, Amy E.; Hart, Patrick E.; Conrad, James E.; Cochran, Susan A.; Johnson, Samuel Y.; Cochran, Susan A.

    2013-01-01

    In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP), designed to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats, and geology within the 3-nautical-mile limit of California’s State Waters. The CSMP approach is to create highly detailed seafloor maps through collection, integration, interpretation, and visualization of swath sonar data, acoustic backscatter, seafloor video, seafloor photography, high-resolution seismic-reflection profiles, and bottom-sediment sampling data. The map products display seafloor morphology and character, identify potential marine benthic habitats, and illustrate both the surficial seafloor geology and shallow (to about 100 m) subsurface geology. The Offshore of Santa Barbara map area lies within the central Santa Barbara Channel region of the Southern California Bight. This geologically complex region forms a major biogeographic transition zone, separating the cold-temperate Oregonian province north of Point Conception from the warm-temperate California province to the south. The map area is in the southern part of the Western Transverse Ranges geologic province, which is north of the California Continental Borderland. Significant clockwise rotation—at least 90°—since the early Miocene has been proposed for the Western Transverse Ranges province, and geodetic studies indicate that the region is presently undergoing north-south shortening. Uplift rates (as much as 2.2 mm/yr) that are based on studies of onland marine terraces provide further evidence of significant shortening. The city of Santa Barbara, the main coastal population center in the map area, is part of a contiguous urban area that extends from Carpinteria to Goleta. This urban area was developed on the coalescing alluvial surfaces, uplifted marine terraces, and low hills that lie south of the east-west-trending Santa Ynez Mountains. Several beaches line the actively

  3. Preliminary geologic map of the Santa Barbara coastal plain area, Santa Barbara County, California

    USGS Publications Warehouse

    Minor, Scott A.; Kellogg, Karl S.; Stanley, Richard G.; Stone, Paul; Powell, Charles L.; Gurrola, Larry D.; Selting, Amy J.; Brandt, Theodore R.

    2002-01-01

    This report presents a new geologic digital map of the Santa Barbara coastal plain area at a compilation scale of 1:24,000 (one inch on the map = 2,000 feet on the ground) and with a horizontal positional accuracy of at least 20 m. This preliminary map depicts the distribution of bedrock units and surficial deposits and associated deformation underlying and adjacent to the coastal plain within the contiguous Santa Barbara and Goleta 7.5' quadrangles. A planned second version will extend the mapping westward into the adjoining Dos Pueblos Canyon quadrangle and eastward into the Carpinteria quadrangle. The mapping presented here results from the collaborative efforts of geologists with the U.S. Geological Survey Southern California Areal Mapping Project (SCAMP) (Minor, Kellogg, Stanley, Stone, and Powell) and the tectonic geomorphology research group at the University of California at Santa Barbara (Gurrola and Selting). C.L. Powell, II, performed all new fossil identifications and interpretations reported herein. T.R. Brandt designed and edited the GIS database,performed GIS database integration and created the digital cartography for the map layout. The Santa Barbara coastal plain is located in the western Transverse Ranges physiographic province along a west-trending segment of the southern California coastline about 100 km (62 mi) northwest of Los Angeles. The coastal plain region, which extends from the Santa Ynez Mountains on the north to the Santa Barbara Channel on the south, is underlain by numerous active and potentially active folds and partly buried thrust faults of the Santa Barbara fold and fault belt. Strong earthquakes that occurred in the region in 1925 (6.8 magnitude) and 1978 (5.1 magnitude) are evidence that such structures pose a significant earthquake hazard to the approximately 200,000 people living within the major coastal population centers of Santa Barbara and Goleta. Also, young landslide deposits along the steep lower flank of the Santa

  4. Monterey fractured reservoir, Santa Barbara Channel, California

    SciTech Connect

    Belfield, W.C.; Helwig, J.; La Pointe, P.R.; Dahleen, W.K.

    1983-03-01

    The South Elwood field in the Santa Barbara Channel is a faulted anticline with cumulative production of 14.5 million bbl from the Monterey Formation as of September 1, 1982. The distributions of pressure, flow rates, and oil-water contacts and the low average matrix permeability of 0.2 md require a fractured reservoir. Core and outcrop studies show a dominant fracture set characterized by vertical, lithologically controlled fractures oriented across strike, and breccias controlled by lithology and structure. Generally, the fracture intensity is unaffected by structural position or bed curvature but is controlled by lithology and bed thickness. Other varieties of fracturing in the Monterey are related to a protracted history of diagenesis, deformation, and fluid injection. Three types of tar-bearing breccias occur in the Monterey Formation: stratigraphic breccia, coalescent-fracture breccia, and fault-related breccia. Formation of breccias probably involves high pore pressures. Because of their polygenetic origin, breccia masses have diverse orientations paralleling bedding or fracture/fault systems. In conclusions, fracturing and brecciation of the Monterey Formation reflect the interplay between processes of diagenesis, deformation, and fluid dynamics. The most important features of the reservoir in the area of the present study are: (1) vertical fractures oriented normal to the structural trends and inferred to be favorably oriented (to remain open) with respect to the regional minimum horizontal stress; and (2) breccias that are both stratigraphically and structurally controlled and inferred to be related to the interaction of rock stress and fluid dynamics.

  5. 76 FR 31242 - Revisions to the California State Implementation Plan, Santa Barbara County Air Pollution Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-31

    ... Environmental protection, Air pollution control, Incorporation by reference, Intergovernmental relations... Identification of plan. * * * * * (c) * * * (359) * * * (i) * * * (E) Santa Barbara County Air Pollution Control... AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, Santa Barbara County...

  6. Groundwater quality in the Santa Barbara Coastal Plain, California

    USGS Publications Warehouse

    Davis, Tracy A.; Belitz, Kenneth

    2016-10-03

    Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California established the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. The Santa Barbara Coastal Plain is one of the study units.

  7. Geologic Map of the Santa Barbara Coastal Plain Area, Santa Barbara County, California

    USGS Publications Warehouse

    Minor, Scott A.; Kellogg, Karl S.; Stanley, Richard G.; Gurrola, Larry D.; Keller, Edward A.; Brandt, Theodore R.

    2009-01-01

    This report presents a newly revised and expanded digital geologic map of the Santa Barbara coastal plain area at a compilation scale of 1:24,000 (one inch on the map to 2,000 feet on the ground)1 and with a horizontal positional accuracy of at least 20 m. The map depicts the distribution of bedrock units and surficial deposits and associated deformation underlying and adjacent to the coastal plain within the contiguous Dos Pueblos Canyon, Goleta, Santa Barbara, and Carpinteria 7.5' quadrangles. The new map supersedes an earlier preliminary geologic map of the central part of the coastal plain (Minor and others, 2002; revised 2006) that provided coastal coverage only within the Goleta and Santa Barbara quadrangles. In addition to new mapping to the west and east, geologic mapping in parts of the central map area has been significantly revised from the preliminary map compilation - especially north of downtown Santa Barbara in the Mission Ridge area - based on new structural interpretations supplemented by new biostratigraphic data. All surficial and bedrock map units, including several new units recognized in the areas of expanded mapping, are described in detail in the accompanying pamphlet. Abundant new biostratigraphic and biochronologic data based on microfossil identifications are presented in expanded unit descriptions of the marine Neogene Monterey and Sisquoc Formations. Site-specific fault kinematic observations embedded in the digital map database are more complete owing to the addition of slip-sense determinations. Finally, the pamphlet accompanying the present report includes an expanded and refined summary of stratigraphic and structural observations and interpretations that are based on the composite geologic data contained in the new map compilation. The Santa Barbara coastal plain is located in the western Transverse Ranges physiographic province along an east-west-trending segment of the southern California coastline about 100 km (62 mi) northwest

  8. Bathymetry and Acoustic Backscatter: Northern Santa Barbara Channel, Southern California

    USGS Publications Warehouse

    Dartnell, Pete; Finlayson, David; Conrad, Jamie; Cochrane, Guy; Johnson, Samuel

    2010-01-01

    In the summer of 2008, as part of the California Seafloor Mapping Program (CSMP) the U.S. Geological Survey, Coastal and Marine Geology mapped a nearshore region of the northern Santa Barbara Channel in Southern California (fig 1). The CSMP is a cooperative partnership between Federal and State agencies, Universities, and Industry to create a comprehensive coastal/marine geologic and habitat basemap series to support the Marine Life Protection Act (MLPA) inititive. The program is supported by the California Ocean Protection Council and the California Coastal Conservancy. The 2008 mapping collected high resolution bathymetry and acoustic backscatter data using a bathymetric side scan system within State waters from about the 10-m isobath out over 3-nautical miles. This Open-File Report provides these data in a number of different formats, as well as a summary of the mapping mission, maps of bathymetry and backscatter, and FGDC metadata.

  9. 75 FR 45082 - Revisions to the California State Implementation Plan, Santa Barbara County Air Pollution Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-02

    ... Air Pollution Control District (SBCAPCD) portion of the California State Implementation Plan (SIP... Environmental protection, Air pollution control, Intergovernmental relations, Nitrogen dioxide, Ozone, Reporting... AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, Santa Barbara County...

  10. Geologic Map of the Goleta Quadrangle, Santa Barbara County, California

    USGS Publications Warehouse

    Minor, Scott A.; Kellogg, Karl S.; Stanley, Richard G.; Brandt, Theodore R.

    2007-01-01

    This map depicts the distribution of bedrock units and surficial deposits and associated deformation underlying those parts of the Santa Barbara coastal plain and adjacent southern flank of the Santa Ynez Mountains within the Goleta 7 ?? quadrangle at a compilation scale of 1:24,000 (one inch on the map = 2,000 feet on the ground) and with a horizontal positional accuracy of at least 20 m. The Goleta map overlaps an earlier preliminary geologic map of the central part of the coastal plain (Minor and others, 2002) that provided coverage within the coastal, central parts of the Goleta and contiguous Santa Barbara quadrangles. In addition to new mapping in the northern part of the Goleta quadrangle, geologic mapping in other parts of the map area has been revised from the preliminary map compilation based on new structural interpretations supplemented by new biostratigraphic data. All surficial and bedrock map units are described in detail in the accompanying map pamphlet. Abundant biostratigraphic and biochronologic data based on microfossil identifications are presented in expanded unit descriptions of the marine Neogene Monterey and Sisquoc Formations. Site-specific fault-kinematic observations (including slip-sense determinations) are embedded in the digital map database. The Goleta quadrangle is located in the western Transverse Ranges physiographic province along an east-west-trending segment of the southern California coastline about 100 km (62 mi) northwest of Los Angeles. The Santa Barbara coastal plain surface, which spans the central part of the quadrangle, includes several mesas and hills that are geomorphic expressions of underlying, potentially active folds and partly buried oblique and reverse faults of the Santa Barbara fold and fault belt (SBFFB). Strong earthquakes have occurred offshore within 10 km of the Santa Barbara coastal plain in 1925 (6.3 magnitude), 1941 (5.5 magnitude) and 1978 (5.1 magnitude). These and numerous smaller seismic events

  11. SRTM Perspective View with Landsat Overlay: Santa Barbara, California

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Santa Barbara, California, is often called 'America's Riviera.' It enjoys a Mediterranean climate, a mountain backdrop, and a long and varied coastline. This perspective view of the Santa Barbara region was generated using data from the Shuttle Radar Topography Mission (SRTM) and an enhanced Landsat satellite image. The view is toward the northeast, from the Goleta Valley in the foreground to a snow-capped Mount Abel (elevation 2526 m or 8286 feet) along the skyline. The coast here generally faces south. Consequently, Fall and Winter sunrises occur over the ocean, which is unusual for the U.S. west coast. The Santa Barbara 'back country' is very rugged and largely remains as undeveloped wilderness and an important watershed for local communities. Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data match the 30-meter resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive. For visualization purposes, topographic heights displayed in this image are exaggerated two times. Colors approximate natural colors.

    The elevation data used in this image was acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of Earth's land surface.

    To collect the 3-D SRTM data, engineers added a mast 60 meters (about 200-feet) long, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif, for NASA's Earth Science Enterprise,Washington, D.C. JPL

  12. 33 CFR 165.1157 - Security Zone; Cruise Ships, Santa Barbara, California.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Security Zone; Cruise Ships... § 165.1157 Security Zone; Cruise Ships, Santa Barbara, California. (a) Location. The following areas are... cruise ship located within 3 nautical miles of the Santa Barbara Harbor Breakwater Light (Light...

  13. 33 CFR 165.1157 - Security Zone; Cruise Ships, Santa Barbara, California.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Security Zone; Cruise Ships... § 165.1157 Security Zone; Cruise Ships, Santa Barbara, California. (a) Location. The following areas are... cruise ship located within 3 nautical miles of the Santa Barbara Harbor Breakwater Light (Light...

  14. 78 FR 53711 - Revisions to the California State Implementation Plan, Placer, Santa Barbara and Ventura County...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-30

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, Placer, Santa Barbara and... District (PCAPCD), Santa Barbara County Air Pollution Control District (SBCAPCD) and Ventura County...

  15. SRTM Perspective View with Landsat Overlay: Santa Barbara Coastline, California

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This image of the Santa Barbara, California, region provides a beautiful snapshot of the area's rugged mountains and long and varied coastline. Generated using data acquired from the Shuttle Radar Topography Mission (SRTM) and an enhanced Landsat image this is a perspective view toward the northeast, from the Goleta Valley in the foreground to a snow-capped Mount Abel (elevation 2,526 m or 8,286 feet) along the skyline at the left. On a clear day, a pilot might see a similar view shortly before touching down on the east-west runway of the Santa Barbara Airport, seen just to the left of the coastline near the center of image. This area is one of the few places along the U.S. West Coast where because of a south-facing beach, fall and winter sunrises occur over the ocean.

    Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data match the 30-meter(98-foot) resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive. For visualization purposes, topographic heights displayed in this image are exaggerated two times. Colors approximate natural colors.

    The elevation data used in this image was acquired by SRTM aboard Space Shuttle Endeavour, launched on February 11,2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of Earth's land surface. To collect the 3-D SRTM data, engineers added a mast 60 meters (about 200-feet)long, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif, for NASA's Earth Science

  16. Ground-water reconnaissance of the Santa Barbara-Montecito area, Santa Barbara County, California

    USGS Publications Warehouse

    Muir, K.S.

    1968-01-01

    This is the third interpretive report prepared by the U.S. Geological Survey in cooperation with the Santa Barbara County Water Agency on the groundwater resources of areas along the south coast of the county. The two previous reports--one by J. E. Upson in 1951 and another by R. E. Evenson, H. D. Wilson, Jr., and K. S. Muir--were on ground-water conditions in the Goleta and Carpinteria basins. The Santa Barbara-Montecito area is between those two basins-the Goleta basin on the west and the Carpinteria basin on the east. This area of about 30 square miles extends from the Pacific Ocean on the south to the Santa Inez Mountains on the north. The city of Santa Barbara and the towns of Montecito and Summerland are within the area. The Santa Barbara-Montecito area is a low-lying flat section of the coastal plain. Farther inland are highlands of consolidated rock and terrace deposits. The highlands are areas of uplift, folding, and faulting, and the lowlands are structural depressions. Most of the urban development in the area has been in the lowlands. The unconsolidated deposits that have partly filled the structural depressions make up the ground-water reservoir of the Santa Barbara-Montecito area. They include the Santa Barbara Formation of Pliocene and Pleistocene age, the Casitas Formation of Pleistocene age, and the alluvium of late Pleistocene and Recent age. These deposits underlie an area of about 20 square miles and have a maximum thickness of about 2,000 feet. The consolidated rocks of Tertiary age that underlie and form the boundaries of the ground-water reservoir contain ground water in fractures and in sandstone beds. However, the consolidated rocks are not an important source of ground water. In 1959, a year the ground-water basins were full and ground water in storage was at a maximum, storage in the Santa Barbara area was 184,000 acre-feet, and storage in the Montecito area was 97,000 acre-feet. By 1964, in response to below-average recharge and

  17. Permeability of the South Ellwood Fault, Offshore Santa Barbara, California

    NASA Astrophysics Data System (ADS)

    Boles, J. R.; Horner, S.; Garven, G.

    2009-12-01

    Natural methane migrates from faulted and fractured siliceous Miocene-age shale hydrocarbon reservoirs to the seabed of the Santa Barbara channel in southern California. At one locality near Platform Holly, about 2 km offshore, where seepage is monitored from two steel and concrete tents on the seabed (area~1860 m2), seepage rate can be related to wells producing 1 km beneath the tents. A new well, perforated at 914 m (3000 ft) beneath the collection tents, directly affects the seepage into the tents. When the well is shut down, seepage production rates increase at a constant rate of 45.3 m3 day/day (1.6 MCF/day/day) to 31.2 m3 day/day (1.1 MCF/day/day) over shutdown periods ranging from 21 days in 2003 to 45 days in 2005, respectively. Using seismic and well data, a fault with about 60 m (200 ft) of throw has been identified running along the crest of the South Ellwood anticline. Using these changes in flow rate, the estimated pressure differences between the seep tent and the perforation intervals in the well, we have calculated the permeability with respect to gas for the 914 m fracture/fault flow path, assuming steady Darcian flow, to be about 3.0E-14 m2 (30 millidarcys, md). In another well, no longer in production, we observe tidal-cycle pressure variations indicating communication with the seabed and anomalous pressure build up that indicates influx of about 5 m3 (25 barrels) of seawater per day. Chemical and isotopic analysis confirms seawater mixing into the reservoir. Using an estimated fault volume of 6.3E+05 m3, we calculate a permeability of 1.9E-14 m2 (19 md) from the Darcy equation (Boles and Horner, 2003) for this well. These two permeability estimates, calculated by different methods, are remarkably similar and indicate that large fault conduits can have permeability of 10’s of md over kilometer length scales. Note: MCF= thousand cubic feet

  18. 76 FR 5319 - Revisions to the California State Implementation Plan, Santa Barbara Air Pollution Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-31

    ... AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, Santa Barbara Air Pollution Control District, Placer County Air Pollution Control District, Antelope Valley Air Quality Management District, and Ventura County Air Pollution Control District AGENCY: Environmental Protection Agency...

  19. 76 FR 5277 - Revisions to the California State Implementation Plan, Santa Barbara Air Pollution Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-31

    ... AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, Santa Barbara Air Pollution Control District, Antelope Valley Air Quality Management District, Ventura County Air Pollution Control District and Placer County Air Pollution Control District AGENCY: Environmental Protection Agency...

  20. Coastal Processes Study of Santa Barbara and Ventura Counties, California

    USGS Publications Warehouse

    Barnard, Patrick L.; Revell, David L.; Hoover, Dan; Warrick, Jon; Brocatus, John; Draut, Amy E.; Dartnell, Pete; Elias, Edwin; Mustain, Neomi; Hart, Pat E.; Ryan, Holly F.

    2009-01-01

    The Santa Barbara littoral cell (SBLC) is a complex coastal system with significant management challenges. The coastline ranges broadly in exposure to wave energy, fluvial inputs, hard structures, and urbanization. Geologic influence (structural control) on coastline orientation exerts an important control on local beach behavior, with anthropogenic alterations and the episodic nature of sediment supply and transport also playing important roles. Short- and long-term temporal analyses of shoreline change, beach width, and volume change show no obvious trends in regional beach behavior. Extensive armoring along the SBLC has accreted the back beach, narrowing beach widths and in some cases increasing sediment transport. Unarmored beaches have exhibited mild erosion while maintaining similar widths. Harbor constructions have had notable impacts on downdrift beaches, but once the coastal system has equilibrated the signal becomes strongly dampened and littoral-drift gradients driven by natural shoreline orientation again become dominant. Sediment inputs from the Santa Clara River dominate sediment processes on beaches to the south. The SBLC is dominated by episodic flood and storm-wave events. Exceptionally large accretion signals along this stretch of coastline are closely tied to major flood events when large amounts of sediment are deposited in deltas. These deltas decay over time, supplying downdrift beaches with sediment. Storm-wave impacts and gradients in alongshore transport can lead to beach rotations and migrating erosion hotspots when geological controls are weak. Annual and seasonal rates of cross-shore and alongshore transport are at least 2-3 times higher for the more west- and southwest-facing beaches south of the Ventura River as compared to the more sheltered beaches to the west/north. Gross littoral transports are good approximations of net littoral transports for beaches west/north of Ventura as transport is almost purely unidirectional. However

  1. Water-resources optimization model for Santa Barbara, California

    USGS Publications Warehouse

    Nishikawa, T.

    1998-01-01

    A simulation-optimization model has been developed for the optimal management of the city of Santa Barbara's water resources during a drought. The model, which links groundwater simulation with linear programming, has a planning horizon of 5 years. The objective is to minimize the cost of water supply subject to: water demand constraints, hydraulic head constraints to control seawater intrusion, and water capacity constraints. The decision variables are montly water deliveries from surface water and groundwater. The state variables are hydraulic heads. The drought of 1947-51 is the city's worst drought on record, and simulated surface-water supplies for this period were used as a basis for testing optimal management of current water resources under drought conditions. The simulation-optimization model was applied using three reservoir operation rules. In addition, the model's sensitivity to demand, carry over [the storage of water in one year for use in the later year(s)], head constraints, and capacity constraints was tested.

  2. Optical assessment of particle size and composition in the Santa Barbara Channel, California.

    PubMed

    Kostadinov, Tihomir Sabinov; Siegel, David A; Maritorena, Stéphane; Guillocheau, Nathalie

    2012-06-01

    The suspended particle assemblage in complex coastal waters is a mixture of living phytoplankton, other autochthonous matter, and materials of terrestrial origin. The characterization of suspended particles is important for understanding regional primary productivity and rates of carbon sequestration, the fate of anthropogenic materials released to the coastal environment, as well as its effects on bulk optical properties, which influence the passive optical remote sensing of the coastal ocean. Here, the extensive bio-optical Plumes and Blooms data set is used to characterize the surface particle assemblage in the Santa Barbara Channel, California, a highly productive, upwelling-dominated, coastal site affected by episodic sediment inputs. Available variables sensitive to characteristics of the particle assemblage include particle beam attenuation and backscattering coefficients, High Performance Liquid Chromatography (HPLC) pigment concentration observations, chlorophyll and particulate organic carbon concentration, particulate and phytoplankton absorption coefficients, and Laser In-situ Scattering and Transmissometry (LISST) 100-X particle sizer observations. Comparisons among these particle assemblage proxy variables indicate good agreement and internal consistency among the data set. Correlations among chlorophyll concentration, particulate organic carbon concentration (POC), HPLC pigments, and proxies sensitive to the entire particle assemblage such as backscattering and LISST data strongly indicate that in spite of its coastal character, variability in the particle assemblage in the Santa Barbara Channel is dominated by its marine biogenic component. Relatively high estimates of the bulk real index of refraction and its positive correlation with chlorophyll and lithogenic silica concentration tentatively indicate that there is minerogenic particle influence in the Santa Barbara Channel that tends to covary with the phytoplankton blooms. Limitations of each

  3. Status of groundwater quality in the Santa Barbara Study Unit, 2011: California GAMA Priority Basin Project

    USGS Publications Warehouse

    Davis, Tracy A.; Kulongoski, Justin T.

    2016-10-03

    Groundwater quality in the 48-square-mile Santa Barbara study unit was investigated in 2011 as part of the California State Water Resources Control Board’s Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project. The study unit is mostly in Santa Barbara County and is in the Transverse and Selected Peninsular Ranges hydrogeologic province. The GAMA Priority Basin Project is carried out by the U.S. Geological Survey in collaboration with the California State Water Resources Control Board and Lawrence Livermore National Laboratory.The GAMA Priority Basin Project was designed to provide a statistically unbiased, spatially distributed assessment of the quality of untreated groundwater in the primary aquifer system of California. The primary aquifer system is defined as that part of the aquifer corresponding to the perforation interval of wells listed in the California Department of Public Health database for the Santa Barbara study unit. This status assessment is intended to characterize the quality of groundwater resources in the primary aquifer system of the Santa Barbara study unit, not the treated drinking water delivered to consumers by water purveyors.The status assessment for the Santa Barbara study unit was based on water-quality and ancillary data collected in 2011 by the U.S. Geological Survey from 23 sites and on water-quality data from the California Department of Public Health database for January 24, 2008–January 23, 2011. The data used for the assessment included volatile organic compounds; pesticides; pharmaceutical compounds; two constituents of special interest, perchlorate and N-nitrosodimethylamine (NDMA); and naturally present inorganic constituents, such as major ions and trace elements. Relative-concentrations (sample concentration divided by the health- or aesthetic-based benchmark concentration) were used to evaluate groundwater quality for those constituents that have federal or California regulatory and non

  4. International Conference on Mechanical Fatigue of Advanced Materials Held in Santa Barbara, California on 13-18 January 1991

    DTIC Science & Technology

    1991-02-15

    University of California at Santa Barbara Ohya , Kanji, General Manager NGK Spark Plug Co., Ltd. Ota, Mark NGK Spark Plug Co., Inc. Pelloux, Regis M ...Long and Short Cracks- in Silicon Nitride" Y. Mutoh and M . Takahaslii "Cyclic Fatigue Properties of Sintered Si3N4’ K. Ohya . M . Takatsu. and K. Ogura...2 M onolithic M etals

  5. Preliminary report on water storage capacity of unconsolidated deposits beneath the Lompoc Plain, Santa Barbara County, California

    USGS Publications Warehouse

    Upson, Joseph E.

    1943-01-01

    The Lompoc Plain is the central lowland of a topographic and structural basin that forms the western and lower part of the Santa Ynes Valley in Santa Barbara County, California. It extends inland about 11 miles from the coast and is 1 mile fto about 3 miles wide.

  6. User Evaluation: Summary of the Methodologies and Results for the Alexandria Digital Library, University of California at Santa Barbara.

    ERIC Educational Resources Information Center

    Hill, Linda L.; Dolin, Ron; Frew, James; Kemp, Randall B.; Larsgaard, Mary; Montello, Daniel R.; Rae, Mary-Anna; Simpson, Jason

    1997-01-01

    The collection and services of the Alexandria Digital Library (ADL) at the University of California Santa Barbara focus on geospatial information sources with links to geographic locations. Evaluation studies conducted within the ADL project are described as well as what was learned about user characteristics and reactions to ADL. (Author/AEF)

  7. Bathymetry and acoustic backscatter-outer mainland shelf, eastern Santa Barbara Channel, California

    USGS Publications Warehouse

    Dartnell, Peter; Finlayson, David P.; Ritchie, Andrew C.; Cochrane, Guy R.; Erdey, Mercedes D.

    2012-01-01

    In 2010 and 2011, scientists from the U.S. Geological Survey (USGS), Pacific Coastal and Marine Science Center (PCMSC), acquired bathymetry and acoustic-backscatter data from the outer shelf region of the eastern Santa Barbara Channel, California. These surveys were conducted in cooperation with the Bureau of Ocean Energy Management (BOEM). BOEM is interested in maps of hard-bottom substrates, particularly natural outcrops that support reef communities in areas near oil and gas extraction activity. The surveys were conducted using the USGS R/V Parke Snavely, outfitted with an interferometric sidescan sonar for swath mapping and real-time kinematic navigation equipment. This report provides the bathymetry and backscatter data acquired during these surveys in several formats, a summary of the mapping mission, maps of bathymetry and backscatter, and Federal Geographic Data Committee (FGDC) metadata.

  8. Hyperpycnal plume-derived fans in the Santa Barbara Channel, California

    USGS Publications Warehouse

    Warrick, Jonathan A.; Simms, Alexander R.; Ritchie, Andy; Steel, Elisabeth; Dartnell, Pete; Conrad, James E.; Finlayson, David P.

    2013-01-01

    Hyperpycnal gravity currents rapidly transport sediment across shore from rivers to the continental shelf and deep sea. Although these geophysical processes are important sediment dispersal mechanisms, few distinct geomorphic features on the continental shelf can be attributed to hyperpycnal flows. Here we provide evidence of large depositional features derived from hyperpycnal plumes on the continental shelf of the northern Santa Barbara Channel, California, from the combination of new sonar, lidar, and seismic reflection data. These data reveal lobate fans directly offshore of the mouths of several watersheds known to produce hyperpycnal concentrations of suspended sediment. The fans occur on an upwardly concave section of the shelf where slopes decrease from 0.04 to 0.01, and the location of these fans is consistent with wave- and auto-suspending sediment gravity current theories. Thus, we provide the first documentation that the morphology of sediment deposits on the continental shelf can be dictated by river-generated hyperpycnal flows.

  9. Kirschenmann Road multi-well monitoring site, Cuyama Valley, Santa Barbara County, California

    USGS Publications Warehouse

    Everett, R.R.; Hanson, R.T.; Sweetkind, D.S.

    2011-01-01

    The U.S. Geological Survey (USGS), in cooperation with the Water Agency Division of the Santa Barbara County Department of Public Works, is evaluating the geohydrology and water availability of the Cuyama Valley, California (fig. 1). As part of this evaluation, the USGS installed the Cuyama Valley Kirschenmann Road multiple-well monitoring site (CVKR) in the South-Main subregion of the Cuyama Valley (fig. 1). The CVKR well site is designed to allow for the collection of depth-specific water-level and water-quality data. Data collected at this site provides information about the geology, hydrology, geophysics, and geochemistry of the local aquifer system, thus, enhancing the understanding of the geohydrologic framework of the Cuyama Valley. This report presents the construction information and initial geohydrologic data collected from the CVKR monitoring site, along with a brief comparison to selected supply and irrigation wells from the major subregions of the Cuyama Valley (fig. 1).

  10. Potential earthquake faults offshore Southern California, from the eastern Santa Barbara Channel south to Dana Point

    USGS Publications Warehouse

    Fisher, M.A.; Sorlien, C.C.; Sliter, R.W.

    2009-01-01

    Urban areas in Southern California are at risk from major earthquakes, not only quakes generated by long-recognized onshore faults but also ones that occur along poorly understood offshore faults. We summarize recent research findings concerning these lesser known faults. Research by the U.S. Geological Survey during the past five years indicates that these faults from the eastern Santa Barbara Channel south to Dana Point pose a potential earthquake threat. Historical seismicity in this area indicates that, in general, offshore faults can unleash earthquakes having at least moderate (M 5-6) magnitude. Estimating the earthquake hazard in Southern California is complicated by strain partitioning and by inheritance of structures from early tectonic episodes. The three main episodes are Mesozoic through early Miocene subduction, early Miocene crustal extension coeval with rotation of the Western Transverse Ranges, and Pliocene and younger transpression related to plate-boundary motion along the San Andreas Fault. Additional complication in the analysis of earthquake hazards derives from the partitioning of tectonic strain into strike-slip and thrust components along separate but kinematically related faults. The eastern Santa Barbara Basin is deformed by large active reverse and thrust faults, and this area appears to be underlain regionally by the north-dipping Channel Islands thrust fault. These faults could produce moderate to strong earthquakes and destructive tsunamis. On the Malibu coast, earthquakes along offshore faults could have left-lateral-oblique focal mechanisms, and the Santa Monica Mountains thrust fault, which underlies the oblique faults, could give rise to large (M ??7) earthquakes. Offshore faults near Santa Monica Bay and the San Pedro shelf are likely to produce both strike-slip and thrust earthquakes along northwest-striking faults. In all areas, transverse structures, such as lateral ramps and tear faults, which crosscut the main faults, could

  11. Anomalously high uplift rates along the Ventura-Santa Barbara Coast, California-tectonic implications

    USGS Publications Warehouse

    Wehmiller, J. F.; Sarna-Wojcicki, A.; Yerkes, R.F.; Lajoie, K.R.

    1979-01-01

    The NW-SE trending segments of the California coastline from Point Arena to Point Conception (500 km) and from Los Angeles to San Diego (200 km) generally parallel major right-lateral strike-slip fault systems. Minor vertical crustal movements associated with the dominant horizontal displacements along these fault systems are recorded in local sedimentary basins and slightly deformed marine terraces. Typical maximum uplift rates during Late Quaternary time are about 0.3 m/ka, based on U-series ages of corals and amino-acid age estimates of fossil mollusks from the lowest emergent terraces. In contrast, the E-W-trending segments of the California coastline between Point Conception and Los Angeles (200 km) parallel predominantly northward-dipping thrust and high-angle reverse faults of the western Transverse Ranges. Along this coast, marine terraces display significantly greater vertical deformation. Amino-acid age estimates of mollusks from elevated marine terraces along the Ventura-Santa Barbara coast imply anomalously high uplift rates of between 1 and 6 m/ka over the past 40 to 100 ka. The deduced rate of terrace uplift decreases from Ventura to Los Angeles, conforming with a similar trend observed by others in contemporary geodetic data. The more rapid rates of terrace uplift in the western Transverse Ranges reflect N-S crustal shortening that is probably a local accommodation of the dominant right-lateral shear strain along coastal California. ?? 1979.

  12. Geologic Controls on Channel Morphology and Low-Flow Habitat; Rattlesnake Creek, Santa Barbara, California

    NASA Astrophysics Data System (ADS)

    Bean, G.; Keller, E.

    2006-12-01

    Channel morphology and baseflow are limiting factors in sustaining low-flow habitat for the spawning and rearing of endangered southern steelhead trout in southern California. To aid the recovery of steelhead trout, it is imperative to determine how pools are formed and maintained in steep mountain streams, and what hydrogeologic factors control baseflow. Rattlesnake Creek, a steep (6 to 31%) boulder-bedrock channel in Santa Barbara, California, was investigated to determine if geologic and hydrogeologic properties, specifically rock strength and fracture density, control channel morphology and low-flow habitat. Analysis of rock strength, fracture density, and channel morphology using a single-factor analysis of variance, Kolmorgorov-Smirnov test and t-test suggest that rock strength and fracture density of the underlying lithology (bed and banks) does not significantly affect the channel morphology at the 0.05 level of significance. However, this study does show that boulder large roughness elements (LREs) armor the channel, controlling channel gradient and the location, abundance and type of pools. Step pools are the dominant pool type, found in reaches up to 18% where cascades might be expected, and steps are composed of resistant sandstone boulder LREs. Although fracture density does not influence the morphology of the channel, baseflow for low-flow habitat is predominantly supplied through fractures in the coldwater sandstone.

  13. Tidal Fluctuations in a Deep Fault Extending Under the Santa Barbara Channel, California

    NASA Astrophysics Data System (ADS)

    Garven, G.; Stone, J.; Boles, J. R.

    2013-12-01

    Faults are known to strongly affect deep groundwater flow, and exert a profound control on petroleum accumulation, migration, and natural seafloor seepage from coastal reservoirs within the young sedimentary basins of southern California. In this paper we focus on major fault structure permeability and compressibility in the Santa Barbara Basin, where unique submarine and subsurface instrumentation provide the hydraulic characterization of faults in a structurally complex system. Subsurface geologic logs, geophysical logs, fluid P-T-X data, seafloor seep discharge patterns, fault mineralization petrology, isotopic data, fluid inclusions, and structural models help characterize the hydrogeological nature of faults in this seismically-active and young geologic terrain. Unique submarine gas flow data from a natural submarine seep area of the Santa Barbara Channel help constrain fault permeability k ~ 30 millidarcys for large-scale upward migration of methane-bearing formation fluids along one of the major fault zones. At another offshore site near Platform Holly, pressure-transducer time-series data from a 1.5 km deep exploration well in the South Ellwood Field demonstrate a strong ocean tidal component, due to vertical fault connectivity to the seafloor. Analytical models from classic hydrologic papers by Jacob-Ferris-Bredehoeft-van der Kamp-Wang can be used to extract large-scale fault permeability and compressibility parameters, based on tidal signal amplitude attenuation and phase shift at depth. For the South Ellwood Fault, we estimate k ~ 38 millidarcys (hydraulic conductivity K~ 3.6E-07 m/s) and specific storage coefficient Ss ~ 5.5E-08 m-1. The tidal-derived hydraulic properties also suggest a low effective porosity for the fault zone, n ~ 1 to 3%. Results of forward modeling with 2-D finite element models illustrate significant lateral propagation of the tidal signal into highly-permeable Monterey Formation. The results have important practical implications

  14. Health-hazard-evaluation report HETA 87-243-292-1876, Santa Barbara Cottage Hospital, Santa Barbara, California. [Ethylene oxide exposures

    SciTech Connect

    Daniels, W.; Gunter, B.

    1988-02-01

    In response to a request from the Santa Barbara Cottage Hospital, Santa Barbara, California, an evaluation was made of possible health hazards. Attention was directed in particular to waste anesthetic gases and vapors in the Outpatient Surgery Center and the main operating rooms. A second concern was ethylene oxide (EtO) exposures from a gas sterilizer, and samples were taken during operation of this equipment. Personal and area air samples were collected during surgery and analyzed for nitrous oxide (N/sub 2/0), halogenated anesthetic agents, and methyl methacrylate. Only two samples exceeded the NIOSH REL of 25 ppm for N/sub 2/O. Eight samples exceeded the NIOSH REL of 0.5/ppm for halogenated anesthetics used in combination with N/sub 2/O. The Outpatient Surgery Center had only about half the recommended number of air changes per hour. Contaminant concentrations are maintained below the environmental criteria in most samples, but a potential for overexposure to N/sub 2/O and forane exists. The authors recommend improving general ventilation at the facility, work practices, exposure monitoring, equipment maintenance, and the use of scavenging systems for waste gases.

  15. Coastal groundwater dynamics off Santa Barbara, California: combining geochemical tracers, electromagnetic seepmeters, and electrical resistivity

    USGS Publications Warehouse

    Swarzenski, Peter W.; Izbicki, John A.

    2009-01-01

    This paper presents repeat field measurements of 222Rn and 223,224,226,228Ra, electromagnetic seepage meter-derived advective fluxes, and multi-electrode, stationary and continuous marine resistivity surveys collected between November 2005 and April 2007 to study coastal groundwater dynamics within a marine beach in Santa Barbara, California. The study provides insight into magnitude and dynamics of submarine groundwater discharge (SGD) and associated nutrient loadings into near-shore coastal waters, where the predominant SGD drivers can be both spatially and temporally separated. Rn-222 and 223,224,226,228Ra were utilized to quantify the total and saline contribution, respectively, of SGD. The two short-lived 224,223Ra isotopes provided an estimate of apparent near-shore water mass age, as well as an estimate of the Ra-derived eddy diffusion coefficient, Kh (224Ra = 2.86 ?? 0.7 m2 s-1; 223Ra = 1.32 ?? 0.5 m2 s-1). Because 222Rn (t1/2 = 3.8 day) and 224Ra (t1/2 = 3.66 day) have comparable half-lives and production terms, they were used in concert to examine respective water column removal rates. Electromagnetic seepage meters recorded the physical, bi-directional exchange across the sediment/water interface, which ranged from -6.7 to 14.5 cm day-1, depending on the sampling period and position relative to the low tide line. Multi-day time-series 222Rn measurements in the near-shore water column yielded total (saline + fresh) SGD rates that ranged from 3.1 ?? 2.6 to 9.2 ?? 0.8 cm day-1, depending on the sampling season. Offshore 226Ra (t1/2 = 1600 year) and 222Rn gradients were used with the calculated Kh values to determine seabed flux estimates (dpm m-2 day-1), which were then converted into SGD rates (7.1 and 7.9 cm day-1, respectively). Lastly, SGD rates were used to calculate associated nutrient loads for the near-shore coastal waters off Santa Barbara. Depending on both the season and the SGD method utilized, the following SGD-derived nutrient inputs were

  16. Seastacks buried beneath newly reported Lower Miocene sandstone, northern Santa Barbara County, California

    SciTech Connect

    Fritsche, A.E.; Hanna, F.M.

    1985-04-01

    Three large, isolated exposures of a light-gray, coarse-grained, thick-bedded sandstone unit occur in the northern San Rafael Mountains of Santa Barbara County, California. These rocks are moderately fossiliferous and contain Vertipecten bowersi, Amussiopecten vanvlecki, Aequipecten andersoni, Otrea howelli, shark teeth, whale bones, and regular echinoid spines. The fossils indicate that the sandstone unit, although previously reported as upper(.) Miocene, correlates best with the lower Miocene Vaqueros Formation. This unit was deposited in angular unconformity on a Cretaceous, greenish-gray turbidite sequence of interbedded sandstone and shale, and onlaps the unconformity erosion surface from west to east, the unit being thicker in the west and older at its base. The underlying Cretaceous sandstone beds are well indurated, and during the eastward transgression of the early Miocene sea, they resisted wave erosion and stood as seastacks offshore of the advancing coastline, thus creating a very irregular topographic surface upon which the Vaqueros Formation was deposited. Some seastacks were as much as 4 m tall, as indicated by inliers of Cretaceous rock surrounded by 4-m thick sections of the Vaqueros Formation.

  17. Flood-Derived Sand Lobes on the Shelf of the Northern Santa Barbara Channel, Southern California

    NASA Astrophysics Data System (ADS)

    Steel, E.; Simms, A.; Warrick, J. A.; Yokoyama, Y.

    2014-12-01

    Gravity flows in the Santa Barbara Channel (SBC) of Southern California have the potential to damage pipelines leading to offshore petroleum platforms, yet their recurrence intervals and initiation mechanisms remain unknown. The recent discovery of seven fans on the continental shelf of the SBC poses an important question; namely, are the SBC fans deposited by sediment gravity flows capable of damaging shelf infrastructure? The fans lie directly offshore from small mountainous creeks that exceed the suspended sediment threshold of 40 g/L required for plunging at the fluvial-marine interface. Here, we present grain size trends, radiocarbon dates, and overall stratigraphic architecture of two fans in the SBC from eight cores and nine grab samples collected in October, 2013. The snub-nosed geometry of each lobe implies en masse freezing of deposits, but the incorporation of shell material and evidence of erosion in shallow seismic profiles indicate an initially turbulent flow regime. The location and geometry of these features suggests that the fans in the SBC are the result of hybrid hyperpycnal-debris flows, likely during floods associated with El Niño Southern Oscillation. A small shoreface slope break found immediately up-dip from these features suggests that seafloor geometry may play a key role in their deposition. The absence of a similar shoreface slope brake in areas without fans suggests a relationship between fan formation and shelf gradient.

  18. 77 FR 36955 - Security Zone; Cruise Ships, Santa Barbara Harbor, Santa Barbara, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-20

    ... Barbara, California. This proposed regulation is needed for national security reasons to protect cruise... Barbara, California. This security zone helps the Coast Guard to prevent vessels or persons from engaging... and under cruise ships which visit Santa Barbara Harbor, Santa Barbara, California. This proposed...

  19. A simulation-optimization model for water-resources management, Santa Barbara, California

    USGS Publications Warehouse

    Nishikawa, Tracy

    1998-01-01

    In times of drought, the local water supplies of the city of Santa Barbara, California, are insufficient to satisfy water demand. In response, the city has built a seawater desalination plant and gained access to imported water in 1997. Of primary concern to the city is delivering water from the various sources at a minimum cost while satisfying water demand and controlling seawater intrusion that might result from the overpumping of ground water. A simulation-optimization model has been developed for the optimal management of Santa Barbara?s water resources. The objective is to minimize the cost of water supply while satisfying various physical and institutional constraints such as meeting water demand, maintaining minimum hydraulic heads at selected sites, and not exceeding water-delivery or pumping capacities. The model is formulated as a linear programming problem with monthly management periods and a total planning horizon of 5 years. The decision variables are water deliveries from surface water (Gibraltar Reservoir, Cachuma Reservoir, Cachuma Reservoir cumulative annual carryover, Mission Tunnel, State Water Project, and desalinated seawater) and ground water (13 production wells). The state variables are hydraulic heads. Basic assumptions for all simulations are that (1) the cost of water varies with source but is fixed over time, and (2) only existing or planned city wells are considered; that is, the construction of new wells is not allowed. The drought of 1947?51 is Santa Barbara?s worst drought on record, and simulated surface-water supplies for this period were used as a basis for testing optimal management of current water resources under drought conditions. Assumptions that were made for this base case include a head constraint equal to sea level at the coastal nodes; Cachuma Reservoir carryover of 3,000 acre-feet per year, with a maximum carryover of 8,277 acre-feet; a maximum annual demand of 15,000 acre-feet; and average monthly capacities for the

  20. Sundowner Winds Contributing to Intensifying Dry Conditions in Santa Barbara, California

    NASA Astrophysics Data System (ADS)

    Macarewich, S. I.; Carvalho, L. V.; Hall, T.

    2015-12-01

    Extreme downslope wind and warming events, locally termed as "sundowners," are notorious for accelerating the spread of wildfires in the vicinity of Santa Barbara, California. Unique topographic features characterize the terrain of this region: about 100 km of narrow coastal plains run approximately east-west, and are bordered by a steep mountain range (exceeding elevations of 1200 m), which runs parallel to the coastline. Named for their typical onset during the early to late afternoon, Sundowners are foehn winds associated with gusty winds down the lee slope of the mountains and canyons, abnormal rapid drop in relative humidity and rise in temperature. Some Sundowner events can exceed wind speeds of gale force and temperatures of 40°C (~100°F). Not only do these events disrupt the marine-influenced weather regime, they also cause significant damage to agriculture, threaten urban landscapes, and coincide with nearly every major wildfire. Sundowners are mesoscale phenomena that develop as a result of a north to south pressure gradient at the Santa Ynez Mountains. Here, Sundowners are identified using the Montecito remote operated weather station (MTIC1) from December 1999 to February 2014. The MTIC1 is located within a mountain pass where Sundowner winds are most significant. A Sundowner database, provided by the National Weather Service, is used to identify the events. We show that recordings of maximum temperatures, sustained wind speeds, wind gusts, and minimum relative humidity indicate that Sundowner events are increasing in frequency and intensity, particularly in spring. When compared to normal conditions, Sundowner conditions produce a significant increase in evapotranspiration and net radiation that can increase drought conditions in the region. This study examines environmental impacts and discusses potential drivers of Sundowner behavior.

  1. Magnitude and composition of sinking particulate phosphorus fluxes in Santa Barbara Basin, California

    NASA Astrophysics Data System (ADS)

    Sekula-Wood, Emily; Benitez-Nelson, Claudia R.; Bennett, Melissa A.; Thunell, Robert

    2012-06-01

    The composition and bioavailability of particulate P influence marine biological community production on both modern and geologic time-scales, and continental margins play a critical role in the supply, modification, and storage of particulate P. This study examined particulate P cycling in the Santa Barbara Basin (SBB) off the coast of southern California using a ˜520 m deep-moored sediment trap deployed from 1993-2006 and a sediment core collected in 2005 directly beneath the sediment trap at 590 m. Total particulate P (TPP), particulate inorganic P (PIP), and particulate organic P (POP) were quantified using a 5-step sequential extraction method (SEDEX) that chemically separates PIP into loosely bound, oxide-bound, authigenic, and detrital P phases. POP fluxes, while similar in magnitude to other coastal regions (22 ± 10 μmol m-2 d-1) were a small component of the TPP pool (15%). Seasonal trends revealed significant increases in POP fluxes during upwelling due to increased biological production in surface waters by organisms that increased mineral ballast. High particulate organic carbon (POC) to POP ratios (337 ± 18) further indicated rapid and efficient remineralization of POP relative to POC as particles sank through the oxic water column; however, further reduction of POP ceased in the deeper anoxic waters. Loosely bound, oxide-bound, and authigenic P, dominated the TPP pool, with PIP fluxes substantially higher than those measured in other coastal settings. Strong correlations between oxide-associated, authigenic, and detrital P fluxes with lithogenic material indicated a terrestrial source associated with riverine discharge. Furthermore, more than 30% of the loosely bound and oxide-bound P was remineralized prior to burial, with the magnitude of dissolution far exceeding that of POP. These results highlight the dynamic nature of the particulate P pool in coastal ecosystems and how changes in P source can alter the composition and lability of P that

  2. Fluvial Tufa Evidence of Late Pleistocene Wet Intervals from Santa Barbara, Southern California

    NASA Astrophysics Data System (ADS)

    Ibarra, Y.; Corsetti, F. A.; Feakins, S. J.; Rhodes, E. J.; Kirby, M. E.

    2014-12-01

    Past pluvials in the western United States provide valuable context for understanding regional hydroclimate variability. Here we report evidence of conditions substantially wetter than today from fluvial tufa deposits located near Zaca Lake, Santa Barbara County, California that have been dated by radiocarbon (14C) and Infra-Red Stimulated Luminescence (IRSL). Two successions of tufa deposition occur within a small catchment that drains Miocene Monterey Formation bedrock: 1) a fluvial deposit (0-0.5 m thick, 200 m in extent) that formed along a narrow valley below a modern spring, and 2) a perched deposit about 10 m higher (2 m thick, 15 m in extent). IRSL and radiocarbon dating of the perched carbonates suggests at least two episodes of carbonate growth: one at 19.4 ± 2.4 (1σ) through 17.8 ± 2.8 (1σ) ka and another at 11.9 ± 1.5 (1σ) ka verified with a charcoal 14C age of 10.95 ± 0.12 (2σ) cal ka BP. The relationship between the perched and fluvial spring deposits is inferred to represent a drop in the water table of more than 10 m associated with a transition from a wet climate in the late glacial to a dry Holocene today. The wet period indicated by tufa growth between 19.4 and 17.8 ka is relatively consistent with other California climate records both north and south of Zaca Lake. However, tufa growth ca. 12 to 11 ka demonstrates wet conditions occurred as far south as Zaca Lake during the Younger Dryas event, in contrast to climate records farther south in Lake Elsinore indicating persistently dry conditions through this interval. A small shift north in the average position of the winter season storm track could explain wet winters at Zaca while at the same time generating dry winters at Lake Elsinore, 275 km southwest of Zaca. If true, these data indicate that rather small latitudinal shifts in the average winter season storm track can produce large changes in regional hydroclimate.

  3. Modeling of depth to base of Last Glacial Maximum and seafloor sediment thickness for the California State Waters Map Series, eastern Santa Barbara Channel, California

    USGS Publications Warehouse

    Wong, Florence L.; Phillips, Eleyne L.; Johnson, Samuel Y.; Sliter, Ray W.

    2012-01-01

    Models of the depth to the base of Last Glacial Maximum and sediment thickness over the base of Last Glacial Maximum for the eastern Santa Barbara Channel are a key part of the maps of shallow subsurface geology and structure for offshore Refugio to Hueneme Canyon, California, in the California State Waters Map Series. A satisfactory interpolation of the two datasets that accounted for regional geologic structure was developed using geographic information systems modeling and graphics software tools. Regional sediment volumes were determined from the model. Source data files suitable for geographic information systems mapping applications are provided.

  4. Flow of springs and small streams in the Tecolote Tunnel area of Santa Barbara County, California

    USGS Publications Warehouse

    Rantz, S.E.

    1961-01-01

    This report presents the results of an investigation to determine the effect of the construction of Tecolote Tunnel in southern Santa Barbara County, California, on the flow of springs and spring-fed streams in the tunnel area. A program of monthly measurement of discharge for this purpose began in late 1948 at 125 springs and streams; tunnel construction started in March 1950 and was completed in January 1956. By late 1951 appreciable seepage was entering the tunnel. Incidental to the primary objective of this study, but a necessary part of the investigation, were a study of the discharge pattern of the springs and streams of the region, and an evaluation of the effect on flow of both the Arvin-Tehachapi earthquake of July 21, 1952 and the Refugio brush fire of early September 1955. The most striking characteristic of the regimen of flow in the area is the rapid response of discharge to precipitation. An interesting effect was observed in July 1952 when the Arvin-Tehachapi earthquake abruptly increased the flow at 18 measuring sites. At 15 of these sites this effect was felt for only several months, but at three of the sites the effect remained for several years. As for the Refugio fire, there is some reason to believe that the summer flow of many springs and streams may have increased in the years that followed as a result of decreased evapotranspiration losses, but the evidence is inconclusive. The many complex and interrelated factors that influence the discharge of springs and spring-fed streams make it exceedingly difficult to isolate the effect of Tecolote Tunnel on the flow Another major difficulty in evaluating the effect of the tunnel stems from the fact that the calibration period for this study was only three years long, lasting from late 1948 to late 1951, and was uniformly deficient in precipitation, Furthermore, these inadequacies of the calibration period in regard to short length of record and limited range in precipitation, cannot be overcome by

  5. Sources and Pathways of Bacterial Contamination in Urban Streams and Ocean Beaches, Santa Barbara, California

    NASA Astrophysics Data System (ADS)

    Johnson, R. D.; Mendez, G. O.; La, J. X.; Izbicki, J. A.

    2005-12-01

    Streams and ocean beaches in Santa Barbara, California, occasionally have concentrations of fecal indicator bacteria that exceed public health standards for recreational water, forcing temporary beach closures. Possible sources of fecal bacteria contamination include transient human populations, animal populations, and leaking sewer lines. The purpose of this three-year study is to identify important sources of fecal bacteria affecting the urban streams and beaches and to identify important pathways of transport. Contamination may enter streams and beaches directly by surface runoff, but also may be transmitted short distances through shallow ground water. Our analysis of existing historical data shows that fecal indicator bacteria concentrations are higher in near-shore ocean water following extreme high tides. The possible role of near shore ground water in supplying contaminants to the sea will be investigated by sampling water from an array of shallow wells installed for this study between an older city sewer line and the ocean. The ground water flux to the ocean will be inferred from water levels in these wells, and further tested by radium isotope values in near shore ocean samples. Two additional well arrays will be installed to test for leakage from residential sewage hookups and measure associated exchanges between ground water, streams, and ocean. Preliminary data collected by this study show fecal indicator bacteria concentrations in urban reaches of Mission Creek and its tributaries, the principle drainage through the city, are higher during low flow periods than during periods of higher flow. Analysis of preliminary data also shows short-term temporal variations in bacterial concentrations during twenty-four hour periods. Human enterovirus has been detected in our sample from one urban-drain tributary to Mission Creek. In order to identify the origins of fecal indicator bacteria water samples from Mission Creek, its tributaries, urban drains, and

  6. 78 FR 32274 - Scorpion Pier Replacement Project, Channel Islands National Park, Santa Barbara County, California

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-29

    ... National Park Service Scorpion Pier Replacement Project, Channel Islands National Park, Santa Barbara... analysis process for the proposed replacement and potential relocation of the existing Scorpion Pier at..., Attn: Scorpion Pier Project, 1901 Spinnaker Drive, Ventura, CA 93001 or electronically to...

  7. Modeling studies of dissolved organic matter cycling in Santa Barbara Basin (CA, USA) sediments

    NASA Astrophysics Data System (ADS)

    Burdige, David J.; Komada, Tomoko; Magen, Cédric; Chanton, Jeffrey P.

    2016-12-01

    Here we describe new reaction-transport models for the cycling of dissolved organic matter (DOM, both dissolved organic carbon [DOC] and dissolved organic nitrogen [DON]) in anoxic marine sediments, and apply these models to data from Santa Barbara Basin sediment cores (maximum depth of 4.6 m). Model results show that most organic carbon (and nitrogen) flow in the sediments occurs through reactive DOM intermediates that turn over rapidly to produce inorganic remineralization end-products. Refractory DOM is also produced, and the vast majority of this refractory DOM is not remineralized and either escapes as a benthic flux across the sediment-water interface or is buried. Except near the sediment surface, refractory DOM represents >95% of the total pore water DOM. Pore water DOM appears to be consistently depleted in nitrogen as compared to its source organic matter, which may be the result of differential production of carbon- versus nitrogen-containing refractory DOM during remineralization. Refractory DOC (DOCr) in Santa Barbara Basin sediment pore waters is largely produced from degradation of sediment particulate organic carbon (POC). In addition, there is an upward basal flux of DOCr that is strongly depleted in 14C (-810‰). The Δ14C value of DOCr varies according to its source, ranging from +60‰ (a component of surface sediment POC enriched with radiocarbon from nuclear weapons testing in the 1960's) to -810‰ (the basal DOC flux). Each contributes to the DOCr benthic flux, which has a weighted-average Δ14C value of -40‰. The model-determined DOCr benthic flux is roughly half of the total DOC benthic flux, consistent with observations in the literature that sediments are a source of both labile and refractory DOC to bottom waters. These results support previous arguments that sediment benthic fluxes represent an important source of refractory DOC to the oceans. The benthic flux of refractory DOC from these sediments may also contribute pre-aged DOC

  8. Groundwater-quality data in the Santa Barbara study unit, 2011: results from the California GAMA Program

    USGS Publications Warehouse

    Davis, Tracy A.; Kulongoski, Justin T.; Belitz, Kenneth

    2013-01-01

    Groundwater quality in the 48-square-mile Santa Barbara study unit was investigated by the U.S. Geological Survey (USGS) from January to February 2011, as part of the California State Water Resources Control Board (SWRCB) Groundwater Ambient Monitoring and Assessment (GAMA) Program’s Priority Basin Project (PBP). The GAMA-PBP was developed in response to the California Groundwater Quality Monitoring Act of 2001 and is being conducted in collaboration with the SWRCB and Lawrence Livermore National Laboratory (LLNL). The Santa Barbara study unit was the thirty-fourth study unit to be sampled as part of the GAMA-PBP. The GAMA Santa Barbara study was designed to provide a spatially unbiased assessment of untreated-groundwater quality in the primary aquifer system, and to facilitate statistically consistent comparisons of untreated-groundwater quality throughout California. The primary aquifer system is defined as those parts of the aquifers corresponding to the perforation intervals of wells listed in the California Department of Public Health (CDPH) database for the Santa Barbara study unit. Groundwater quality in the primary aquifer system may differ from the quality in the shallower or deeper water-bearing zones; shallow groundwater may be more vulnerable to surficial contamination. In the Santa Barbara study unit located in Santa Barbara and Ventura Counties, groundwater samples were collected from 24 wells. Eighteen of the wells were selected by using a spatially distributed, randomized grid-based method to provide statistical representation of the study unit (grid wells), and six wells were selected to aid in evaluation of water-quality issues (understanding wells). The groundwater samples were analyzed for organic constituents (volatile organic compounds [VOCs], pesticides and pesticide degradates, and pharmaceutical compounds); constituents of special interest (perchlorate and N-nitrosodimethylamine [NDMA]); naturally occurring inorganic constituents (trace

  9. Water levels in observation wells in Santa Barbara County, California, in 1956

    USGS Publications Warehouse

    Muir, K.S.; Merritt, P.M.

    1957-01-01

    Investigation of the ground-water resources of Santa Barbara County was continued during 1956 by the Geological Survey in cooperation with the Santa Barbara County Water Agency. Monthly water-level recorders were operated. Earlier measurements, covering the period 1941 through 1953, have been published in Geological Survey water-Supply Papers; those for 1954 and 1955 are in press and have been released locally in duplicated form. Water-Supply Paper 1068 contains tabulated descriptions of 2,246 wells in existence in 1942 in the various ground-water basins of the county. The same publication contains also many water-level measurements made prior to 1942 by the city of Santa Barbara, Santa Maria Valley Water Conservation District, San Joaquin Power Division of the Pacific Gas and Electric Co., Union Sugar Co., Union Oil Co., and other organizations and individuals. Comprehensive reports on the geology and ground-water resources of the Santa Ynez River basin (Upson and Thomasson, 1951), the south-coast basins (Upson, 1951), the Santa Maria Valley area (Worts, 1951), and the Cuyama Valley (Upson and Worts, 1951) have been published as Water-Supply Papers 1107, 1108, 1000, and 1110-B respectively. A report on stream runoff and ground-water storage capacity of the Santa Ynez River valley (Troxell and Wilson, 1952) was released to the open file in October 1952. A report appraising the ground-water resources of the Santa Ynez River valley (Wilson, 1957) was released to the open file in October 1956.

  10. Southern sea otter range expansion and habitat use in the Santa Barbara Channel, California

    USGS Publications Warehouse

    Tinker, M. Tim; Tomoleoni, Joseph; LaRoche, Nicole; Bowen, Lizabeth; Miles, A. Keith; Murray, Mike; Staedler, Michelle; Randell, Zachary

    2017-01-17

    The re-colonization of the Santa Barbara channel by sea otters brings these ESA-listed marine mammals closer to active oil and gas production facilities, shipping lanes and naturally occurring oil and gas seeps. However, the degree to which sea otters may actually be affected by human-caused oil spills or exposure to natural oil seeps is currently unknown. Between 2012 and 2014, the U.S. Geological Survey and collaborating agencies conducted a telemetry-based study of sea otters in Santa Barbara channel, in order to provide critical information for resource managers (specifically the Bureau of Ocean Energy Management, henceforth BOEM, and the U.S. Fish and Wildlife Service, henceforth USFWS) about the spatial ecology, population status, and potential population threats to sea otters in Santa Barbara Channel, with particular reference to exposure to manmade structures and sources of oil and natural gas. Analysis of spatial monitoring data using a Bayesian-based synoptic model allowed for description of sea otter home ranges, identification of hot-spots of use, and insights into habitat selection behavior by male and female sea otters. Important findings included the deeper modal depth preferred by males versus females, strong preferences by both sexes for areas with persistent kelp canopy, and greater use of soft-sediment areas by males. The synoptic model also provided the ability to predict population-level density distribution for each sex in new habitats: by calculating the value of these probability density distributions at the known locations of natural seeps, we were able to identify those seeps with higher potential for sea otter encounters. The relative probability of occurrence at locations near to some seeps was sufficiently high (about 1% likelihood of occurrence for some of our study animals) that one would anticipate occasional encounters. Data on male and female survival, reproductive success, activity budgets, and body condition all indicated that

  11. The world's most spectacular marine hydrocarbon seeps (Coal Oil Point, Santa Barbara Channel, California): Quantification of emissions

    NASA Astrophysics Data System (ADS)

    Hornafius, J. Scott; Quigley, Derek; Luyendyk, Bruce P.

    1999-09-01

    We used 50 kHz sonar data to estimate natural hydrocarbon emission rates from the 18 km2 marine seep field offshore from Coal Oil Point, Santa Barbara, California. The hydrocarbon gas emission rate is 1.7 ± 0.3 × 105 m3 d-1 (including gas captured by a subsea seep containment device) and the associated oil emission rate is 1.6 ± 0.2 × 104 Ld-1 (100 barrels d-1). The nonmethane hydrocarbon emission rate from the gas seepage is 35±7 td-1 and a large source of air pollution in Santa Barbara County. Our estimate is equal to twice the emission rate from all the on-road vehicle traffic in the county. Our estimated methane emission rate for the Coal Oil Point seeps (80±12 td-1) is 4 times higher than previous estimates. The most intense areas of seepage correspond to structural culminations along anticlinal axes. Seep locations are mostly unchanged from those documented in 1946, 1953, and 1973. An exception is the seepage field that once existed near offshore oil platform Holly. A reduction in seepage within a 1 km radius around this offshore platform is correlated with reduced reservoir pressure beneath the natural seeps due to oil production. Our findings suggest that global emissions of methane from natural marine seepage have been underestimated and may be decreasing because of oil production.

  12. Transport of clays in the eastern part of santa barbara channel, California

    USGS Publications Warehouse

    Kolpack, R.L.; Drake, D.E.

    1984-01-01

    A record discharge of about 54 ?? 106 metric tons of predominantly fine-grained detrital sediment was introduced during 1969 into the eastern part of Santa Barbara Channel from the Santa Clara and Ventura Rivers. The clay-size fraction from bottom samples collected during a time-series of about 18 months revealed movement across the shelf and into the adjacent basin in a repetitive sequential pattern. Light transmission profiles show resuspension and transport of sediments at depths of up to 225 m. This transport and distribution history is attributed to seasonal variations in the vertical and lateral position of a poleward-flowing current. ?? 1985 Springer-Verlag New York Inc.

  13. Metagenomes from two microbial consortia associated with Santa Barbara seep oil.

    PubMed

    Hawley, Erik R; Malfatti, Stephanie A; Pagani, Ioanna; Huntemann, Marcel; Chen, Amy; Foster, Brian; Copeland, Alexander; del Rio, Tijana Glavina; Pati, Amrita; Jansson, Janet R; Gilbert, Jack A; Tringe, Susannah Green; Lorenson, Thomas D; Hess, Matthias

    2014-12-01

    The metagenomes from two microbial consortia associated with natural oils seeping into the Pacific Ocean offshore the coast of Santa Barbara (California, USA) were determined to complement already existing metagenomes generated from microbial communities associated with hydrocarbons that pollute the marine ecosystem. This genomics resource article is the first of two publications reporting a total of four new metagenomes from oils that seep into the Santa Barbara Channel.

  14. Geohydrology of the Foothill ground-water basin near Santa Barbara, California

    USGS Publications Warehouse

    Freckleton, J.R.

    1989-01-01

    Geohydrologic data presented in this report indicate that the East Subbasin of the Goleta groundwater basin and Storage Unit II of the Santa Barbara groundwater basin should be considered as a separate groundwater basin, which is referred to as the Foothill groundwater basin in this report. The 4.5 sq-mi Foothill groundwater basin is bordered on the north and northeast by the Santa Ynez Mountains and on three sides by faults that impede groundwater flow. Sedimentary rocks of Tertiary age underlie the groundwater basin and form its lower boundary. Unconsolidated deposits of the Santa Barbara Formation (Pliocene and Pleistocene age) form the principal aquifer of the basin. Where a zone of low permeability separates it from overlying Quaternary alluvium, the aquifer is confined. In the early 1950's, groundwater levels declined more than 60 ft during periods of heavy pumping. From the mid-1950 's to the late 1970 's, groundwater levels generally rose. Water levels during 1984-87 generally declined. Nitrate concentrations in samples from two wells exceeded the primary maximum contaminant level established by the U.S. Environmental Protection Agency. Secondary maximum contaminant levels for dissolved solids, chloride, and sulfate also were exceeded in some samples. A three-dimensional finite-difference model was developed for part of Foothill groundwater basin. Steady-state verification and transient-state model calibrations were used to estimate or confirm estimates of basin recharge and natural discharge. (USGS)

  15. Survey for least bell's vireo in riparian habitat on Vandenberg Air Force Base, Santa Barbara County, California

    NASA Technical Reports Server (NTRS)

    Breininger, David R.

    1988-01-01

    The least bell's vireo (Vireo bellii pusillus) was listed in 1986 as an endangered species by the U.S. Fish and Wildlife Service. Because of the possibility of the species existing on Vandenberg Air Force Base (VAFB), this survey was conducted to determine if they exist, and if so to prepare a distribution map of the species on the base. Major riparian areas were surveyed on foot for 17 days in April, May, and July 1987. No least bell's vireo were sighted; based on past studies, it is unlikely that there is a significant population on VAFB. There are, however, at least 13 other species of special concern that inhabit VAFB riparian woodlands. Most of these species have declined along the south coast of Santa Barbara County, and many have declined in much of the southern half of California. Riparian areas on VAFB are an important environmental resource for the southern half of California; many of these areas, however, show signs of degradation.

  16. Geohydrology of Storage Unit III and a combined flow model of the Santa Barbara and foothill ground-water basins, Santa Barbara County, California

    USGS Publications Warehouse

    Freckleton, John R.; Martin, Peter; Nishikawa, Tracy

    1998-01-01

    The city of Santa Barbara pumps most of its ground water from the Santa Barbara and Foothill ground-water basins. The Santa Barbara basin is subdivided into two storage units: Storage Unit I and Storage Unit III. The Foothill basin and Storage Unit I of the Santa Barbara basin have been studied extensively and ground-water flow models have been developed for them. In this report, the geohydrology of the Santa Barbara ground- water basin is described with a special emphasis on Storage Unit III in the southwestern part of the basin. The purposes of this study were to summarize and evaluate the geohydrology of Storage Unit III and to develop an areawide model of the Santa Barbara and Foothill basins that includes the previously unmodeled Storage Unit III. Storage Unit III is in the southwestern part of the city of Santa Barbara. It is approximately 3.5 miles long and varies in width from about 2,000 feet in the southeast to 4,000 feet in the north-west. Storage Unit III is composed of the Santa Barbara Formation and overlying alluvium. The Santa Barbara Formation (the principal aquifer) consists of Pleistocene and Pliocene(?) unconsolidated marine sand, silt, and clay, and it has a maximum saturated thickness of about 160 feet. The alluvium that overlies the Santa Barbara Formation has a maximum saturated thickness of about 140 feet. The storage unit is bounded areally by faults and low-permeability deposits and is underlain by rocks of Tertiary age. The main sources of recharge to Storage Unit III are seepage from Arroyo Burro and infiltration of precipitation. Most of the recharge occurs in the northwest part of the storage unit, and ground water flows toward the southeast along the unit's long axis. Lesser amounts of recharge may occur as subsurface flow from the Hope Ranch subbasin and as upwelling from the underlying Tertiary rocks. Discharge from Storage Unit III occurs as pumpage, flow to underground drains, underflow through alluvium in the vicinity of Arroyo

  17. Influence of Harbor construction on downcoast morphological evolution: Santa Barbara, California

    USGS Publications Warehouse

    Revell, D.L.; Barnard, P.L.; Mustain, N.; Storlazzi, C.D.

    2008-01-01

    Sand impoundment caused by construction of the Santa Barbara Harbor in the 1920s, created an erosion wave that impacted downcoast Carpinteria Beach. Historic beach and shoreline changes were analyzed to understand continuing erosion using a combination of historic air photos, lidar, and physical measurements. The long-term analyses show a clockwise rotation with erosion of - 0.35 m/yr at the updrift end and accretion downdrift of 0.3 m/yr. Storm impacts measured before and after the 1982-83 and 1997-98 El Ni??o events show similar rotation patterns, providing evidence that El Ni??os may be driving coastal evolution. Differences in shoreline responses between El Nino events show that the erosion hotspot migrated downdrift following construction of a revetment after the 1982-83 storms. Seasonal field measurements in the winter show beach narrowing while sediment coarsen variably alongshore. The coarsest materials and erosion hotspot are co-located at the end of the revetment on the city beach. Copyright ASCE 2008.

  18. Eustatic and structural control of submarine-fan sedimentation, Conception fan, Santa Barbara basin, California

    SciTech Connect

    Thor, D.R.

    1984-04-01

    Eustatic sea level lows provide an opportunity for submarine-fan development; topography and structure, however, can control depositional-sequence geometry. Analysis of high-resolution seismic data provides a basis to evaluate to the evolution and geometry of the Pleistocene-Holocene Conception fan. The fan formed in the restricted, tectonically active Santo Barbara basin. It consists of 4 vertically stacked depositional sequences, each bounded by nondepositional unconformities. The unconformities are defined by seismic-sequence boundaries and were formed during sea-level falls that are related to Pleistocene glacioeustatic changes. Each depositional sequence consists of lowstand, sandrich facies (fan channel, levee, and lobe) topped by highstand, mud-rich facies. The geometry of the depositional sequences tends to be rectilinear, not arcuate, because lateral progradation is restricted by topographically high structures. The modern fan surface and the Holocene depositional sequence provide a good analog for the older, underlying depositional sequences. The fan surface is characterized by 4 main channels, 2 of which head into submarine canyons incised into the shelf. Submarine canyons that fed the other 2 channels are now filled and have no topographic expression. In addition, numerous partially buried channel segments occur in the interchannel areas. The Holocene depositional sequence consists of lenticular and sheet-drape deposits interpreted to be channel, levee, and lobe facies. The facies geometry suggests that Mutti's topographic compensation, channel migration, and avulsion were typical processes on Conception fan.

  19. Intensive Cultural Resources Survey for the Goleta Flood Protection Program, Santa Barbara County, California.

    DTIC Science & Technology

    1982-04-01

    Seal (Phoco vitulina) and California Sea Lion ( Zalophus californianus ). Black Abalone (Haliotis cracherodii), Purple Olive (Olivella biplicata...Polinices lewisii, Saxidomus a., Mytilus californianus , and Protothaca staminea. A single shark vertebra was also observed. A cluster of five broken...a dense shell midden deposit comprised primarily of Chione s., Tivela stultorum, Protothaca staminea, Saxidomus natalii, and Mytilus californianus

  20. 78 FR 53680 - Revisions to the California State Implementation Plan, Placer, Santa Barbara and Ventura County...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-30

    .... 7401 et seq. Subpart F--California 0 2. Section 52.220, is amended by adding paragraphs (c)(423)(i)(E... there other versions of these rules? C. What is the purpose of the submitted rules? II. EPA's Evaluation and Action A. How is EPA evaluating the rules? B. Do the rules meet the evaluation criteria? C....

  1. Nutrient contributions to the Santa Barbara Channel, California, from the ephemeral Santa Clara River

    USGS Publications Warehouse

    Warrick, J.A.; Washburn, L.; Brzezinski, Mark A.; Siegel, D.A.

    2005-01-01

    The Santa Clara River delivers nutrient rich runoff to the eastern Santa Barbara Channel during brief (???1-3 day) episodic events. Using both river and oceanographic measurements, we evaluate river loading and dispersal of dissolved macronutrients (silicate, inorganic N and P) and comment on the biological implications of these nutrient contributions. Both river and ocean observations suggest that river nutrient concentrations are inversely related to river flow rates. Land use is suggested to influence these concentrations, since runoff from a subwatershed with substantial agriculture and urban areas had much higher nitrate than runoff from a wooded subwatershed. During runoff events, river nutrients were observed to conservatively mix into the buoyant, surface plume immediately seaward of the Santa Clara River mouth. Dispersal of these river nutrients extended 10s of km into the channel. Growth of phytoplankton and nutrient uptake was low during our observations (1-3 days following runoff), presumably due to the very low light levels resulting from high turbidity. However, nutrient quality of runoff (Si:N:P = 16:5:1) was found to be significantly different than upwelling inputs (13:10:1), which may influence different algal responses once sediments settle. Evaluation of total river nitrate loads suggests that most of the annual river nutrient fluxes to the ocean occur during the brief winter flooding events. Wet winters (such as El Nin??o) contribute nutrients at rates approximately an order-of-magnitude greater than "average" winters. Although total river nitrate delivery is considerably less than that supplied by upwelling, the timing and location of these types of events are very different, with river discharge (upwelling) occurring predominantly in the winter (summer) and in the eastern (western) channel. ?? 2004 Elsevier Ltd. All rights reserved.

  2. Morphology, acoustic characteristics, and Late Quaternary growth of conception Fan, Santa Barbara basin, California

    SciTech Connect

    Kraemer, S.M.C.

    1986-04-01

    A radial borderland-basin fan in the western half of the Santa Barbara basin, the Conception Fan, shows characteristics of a debris slope. More than 3000 mi of closely spaced (3.5 kHz) high-resolution profiles, 270 gravity cores, and 8 borings were used to map channel and fan morphology, and channel, levee, and lobe acoustic facies. Two major unconformities are recognized on the seismic profiles. The upper unconformity represents the 10-k.y.B.P. horizon. The lower unconformity is the erosional surface of the late Wisconsinan lowstand of sea level, 18-26 k.y.B.P. Eustasy and tectonism produced two pulses of deposition, each from a different point source, during the Flandrian transgression. Prior to the late Pleistocene, the Conception Fan was fed by one major canyon/channel system, above the western part of the fan. During the late Pleistocene, two small submarine canyons were cut into the slope 7 mi east. Four major channels, smaller than the western channel system, were incised into the fan surface, indicating the eustatic decrease in sediment input. The fault-controlled western canyon (Sacate) fed all but the eastern channel. Faulting and slumping on the slope cut the eastern canyon (Gaviota) and formed the eastern channel. Numerous slope gullies influenced eastern canyon and channel development. Holocene currents rounding Point Conception have winnowed fine sediments in the western channel region, resulting in hummocky topography and the scoured appearance of the channel. Hemipelagic deposition dominates the lower-middle and lower fan of the eastern part of the fan. The western part of the fan seems to be receiving slope-like deposits over the relict fan surface.

  3. The Quaternary North Channel-Pitas Point Fault System in Northwest Santa Barbara Channel, California.

    NASA Astrophysics Data System (ADS)

    Sorlien, C. C.; Nicholson, C.; Behl, R. J.; Marshall, C. J.; Kennett, J.

    2014-12-01

    The north margin of the rapidly-shortening, rapidly subsiding offshore and western onshore Ventura Basin is comprised of major N-dipping faults that step left. Offshore in Santa Barbara Channel, part of the shortening accommodated by the shallow Red Mountain fault is transferred farther offshore to the North Channel-Pitas Point fault system (NC-PP). We previously investigated the eastern offshore 50 km of this fault system using dense grids of industry multichannel seismic reflection (MCS) data and local grids of high resolution MCS data. Timing and rates of the observed deformation were determined by correlation to a detailed dated stratigraphy derived from piston cores that sampled seafloor outcrops back to 740 ka, as well as biostratigraphy, oxygen isotopic stratigraphy, a dated industry well-log horizon, and tephrochonology of the 639 ka Lava Creek ash. We are now continuing our interpretation of the NC-PP through its western 50 km using 2D and 3D MCS data and this previous dated seismic stratigraphy. The PP-NC is variably blind along strike, with its upper tips in places below the 1 Ma horizon and in other locations cutting up to higher levels. The blind slip is absorbed by a progressively-tilting S-dipping forelimb everywhere. Preliminary examination of cross sections through our 8 gridded, depth-converted horizons suggests that the rate of tilting has not significantly changed during the last 1 Myr, and that dips and structural relief, although variable, are not systematically greater in the east than in the west between Carpinteria and the UCSB campus at 119° 50' W.. Farther westward, the rate of tilting, and probably the rate of offshore shortening, decreases steadily through 40 km between 120° 05' W. and the end of the system beyond Point Conception. This trend mirrors the decrease in elevation and structural relief of the Santa Ynez Mountains above the deep fault. As in its eastern part, there is no evidence of a major change in tilt rate through the

  4. Post-Last Glacial Maximum (Latest Pleistocene to Holocene) geology of the Santa Barbara shelf, southern California

    NASA Astrophysics Data System (ADS)

    Johnson, S. Y.; Ritchie, A. C.; Conrad, J. E.; Dartnell, P.; Phillips, E.; Sliter, R. W.

    2011-12-01

    High-resolution bathymetric and seismic-reflection data collected for the California Seafloor Mapping Program (http://walrus.wr.usgs.gov/mapping/csmp/) provide new insights for understanding the post-Last Glacial Maximum (LGM) evolution of the Santa Barbara shelf, highlighting relationships between tectonics, eustasy, and sediment supply. The west-trending shelf extends offshore for 5 to 7 km and is bounded on the south by the deep Santa Barbara basin and on the north by a narrow coastal zone and the steep, rapidly uplifting Santa Ynez Mountains. The active, west-trending, north-dipping Ventura-Pitas Point-North Channel and Red Mountain fault systems form the structural boundary between two distinct shelf domains. The smooth, gently sloping, southern shelf is flooded by thick (35 to 40 m), prograding Santa Clara and Ventura River deltaic deposits. These thick strata drape the shelfbreak and fill the accommodation space created by rising sea level, largely masking the influence of active tectonics. In contrast, the northern shelf has complex bathymetry and a well-defined, sharp shelfbreak at ~90 m water depth. The northern shelf is relatively sediment starved (mean sediment thickness is 3 to 4 m), with thickest accumulations (up to ~18 m) forming shallow (< 30 m), discontinuous to laterally coalescing, inner-shelf bars that are best developed at the mouths of steep coastal watersheds. These watersheds also feed several distinct, coarse-grained sediment lobes (as large as ~1.5 km2, extending to 3 km offshore and depths of 70 m) that probably formed during massive flood events. The relative lack of offshore deposits on the northern shelf suggests sediment transport is dominated by easterly nearshore drift. Faulting and folding on the northern shelf are significant controls on sediment distribution and thickness, the occurrence of bedrock uplifts, and common hydrocarbon-associated seeps, pockmarks, and mounds. Bedrock, typically "soft" Neogene strata, is especially

  5. Proceedings of the 2006 International Workshop on Multiscale Biological Imaging, Data Mining and Informatics, Santa Barbara, USA (BII06).

    PubMed

    2007-07-10

    The 2006 International Workshop on Multiscale Biological Imaging, Data Mining and Informatics was held at Santa Barbara, on Sept 7-8, 2006. Based on the presentations at the workshop, we selected and compiled this collection of research articles related to novel algorithms and enabling techniques for bio- and biomedical image analysis, mining, visualization, and biology applications.

  6. Can genomics clarify the origins of Boreioglycaspis melaleucae in California, USA?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Australian psyllid Boreioglycaspis melaleucae is a biological control agent of Melaleuca quinquenervia in Florida (USA) but was observed attacking M. quinquenervia trees in southern California (USA). Genotyping revealed the California population matched three of eight Australian haplotypes and ...

  7. Ground-water monitoring at Santa Barbara, California; Phase 2, Effects of pumping on water levels and on water quality in the Santa Barbara ground-water basin

    USGS Publications Warehouse

    Martin, Peter

    1984-01-01

    From July 1978 to January 1980, water levels in the southern part of the Santa Barbara ground-water basin declined more than 100 feet. These water-level declines resulted from increases in municipal pumping since July 1978. The increase in municipal pumping was part of a basin-testing program designed to determine the usable quantity of ground water in storage. The pumping, centered in the city less than 1 mile from the coast, has caused water-level declines to altitudes below sea level in the main water-bearing zones. As a result, the ground-water basin would be subject to saltwater intrusion if the study-period pumpage were maintained or increased. Data indicate that saltwater intrusion has degraded the quality of the water yielded from six coastal wells. During the study period, the six coastal wells all yielded water with chloride concentrations in excess of 250 milligrams per liter, and four of the wells yielded water with chloride concentrations in excess of 1,000 milligrams per liter. Previous investigators believed that saltwater intrusion was limited to the shallow part of the aquifer, directly adjacent to the coast. The possibility of saltwater intrusion into the deeper water-bearing deposits in the aquifer was thought to be remote because an offshore fault truncates these deeper deposits so that they lie against consolidated rocks on the seaward side of the fault. Results of this study indicate, however, that ocean water has intruded the deeper water-bearing deposits, and to a much greater extent than in the shallow part of the aquifer. Apparently the offshore fault is not an effective barrier to saltwater intrusion. No physical barriers are known to exist between the coast and the municipal well field. Therefore, if the pumping rate maintained during the basin-testing program were continued, the degraded water along the coast could move inland and contaminate the municipal supply wells. The time required for the degraded water to move from the coast to

  8. Knemidocoptic Mange in Wild Golden Eagles, California, USA

    PubMed Central

    Stephenson, Nicole; Rogers, Krysta; Hawkins, Michelle G.; Sadar, Miranda; Guzman, David Sanchez-Migallon; Bell, Douglas A.; Smallwood, Kenneth S.; Wells, Amy; Shipman, Jessica; Foley, Janet

    2014-01-01

    During 2012–2013 in California, USA, 3 wild golden eagles were found with severe skin disease; 2 died. The cause was a rare mite, most closely related to Knemidocoptes derooi mites. Cautionary monitoring of eagle populations, habitats, and diseases is warranted. PMID:25271842

  9. Burkholderia pseudomallei isolates in 2 pet iguanas, California, USA.

    PubMed

    Zehnder, Ashley M; Hawkins, Michelle G; Koski, Marilyn A; Lifland, Barry; Byrne, Barbara A; Swanson, Alexandra A; Rood, Michael P; Gee, Jay E; Elrod, Mindy Glass; Beesley, Cari A; Blaney, David D; Ventura, Jean; Hoffmaster, Alex R; Beeler, Emily S

    2014-02-01

    Burkholderia pseudomallei, the causative agent of melioidosis, was isolated from abscesses of 2 pet green iguanas in California, USA. The international trade in iguanas may contribute to importation of this pathogen into countries where it is not endemic and put persons exposed to these animals at risk for infection.

  10. Landslides: Geomorphology and Sea Cliff Hazard Potential, Santa Barbara - Isla Vista, California J.F. Klath and E.A. Keller

    NASA Astrophysics Data System (ADS)

    Klath, J. F.; Keller, E. A.

    2015-12-01

    sea level rise estimates, a map displaying likely position of the coastline by 2100 will be created. This information will be useful to the county of Santa Barbara, California when considering future development and hazard mitigation plans.

  11. Wind energy development in California, USA

    USGS Publications Warehouse

    Wilshire, H.; Prose, D.

    1987-01-01

    Windfarms have been developed rapidly in California in the last few years. The impetus has been a legislated goal to generate 10% of California's electricity by windpower by the year 2000, and generous state and federal tax incentives. Windpower is promoted as environmentally benign, which it is in traditional uses. The California program, however, is not traditional: it calls for centralized development of a magnitude sufficient to offset significant amounts of fossil fuels now used to generate electricity. Centralized windfarm development, as exemplified by the Altamont Pass, Tehachapi Mountains, and San Gorgonio Pass developments, involves major road building projects in erosion-sensitive terrain, effective closure of public lands, and other detrimental effects. A windfarm consisting of 200 turbines with 17-m rotors located in steep terrain 16 km from an existing corridor might occupy 235 ha and physically disturb 86 ha. With average annual wind speeds of 22.5 km/h, the farm would generate about 10??106 kWh/year at present levels of capacity. This annual production would offset 1% of one day's consumption of oil in California. To supply 10% of the state's electricity (at 1984 production rates) would require about 600,000 turbines of the type in common use today and would occupy more than 685,000 ha. It is likely that indirect effects would be felt in much larger areas and would include increased air and water pollution resulting from accelerated erosion, degradation of habitat of domestic and wild animals, damage to archaeological sites, and reduction of scenic quality of now-remote areas of the state. ?? 1987 Springer-Verlag New York Inc.

  12. Marine protected area networks in California, USA.

    PubMed

    Botsford, Louis W; White, J Wilson; Carr, Mark H; Caselle, Jennifer E

    2014-01-01

    California responded to concerns about overfishing in the 1990s by implementing a network of marine protected areas (MPAs) through two science-based decision-making processes. The first process focused on the Channel Islands, and the second addressed California's entire coastline, pursuant to the state's Marine Life Protection Act (MLPA). We review the interaction between science and policy in both processes, and lessons learned. For the Channel Islands, scientists controversially recommended setting aside 30-50% of coastline to protect marine ecosystems. For the MLPA, MPAs were intended to be ecologically connected in a network, so design guidelines included minimum size and maximum spacing of MPAs (based roughly on fish movement rates), an approach that also implicitly specified a minimum fraction of the coastline to be protected. As MPA science developed during the California processes, spatial population models were constructed to quantify how MPAs were affected by adult fish movement and larval dispersal, i.e., how population persistence within MPA networks depended on fishing outside the MPAs, and how fishery yields could either increase or decrease with MPA implementation, depending on fishery management. These newer quantitative methods added to, but did not supplant, the initial rule-of-thumb guidelines. In the future, similar spatial population models will allow more comprehensive evaluation of the integrated effects of MPAs and conventional fisheries management. By 2011, California had implemented 132 MPAs covering more than 15% of its coastline, and now stands on the threshold of the most challenging step in this effort: monitoring and adaptive management to ensure ecosystem sustainability.

  13. Barbara Cooney.

    ERIC Educational Resources Information Center

    Horne, Jackie C.

    2000-01-01

    Profiles the life/work of the award winning picture-book author-illustrator Barbara Cooney. Includes her early development as an artist; early attempts at the picture-book form; experimentation with different media: watercolor, pen/ink with wash, charcoal, acrylics, pastels, and collage; later work that draws upon folk-art traditions; her love of…

  14. A preliminary study of the Santa Barbara, California, earthquake of August 13, 1978, and its major aftershocks

    USGS Publications Warehouse

    Lee, William Hung Kan; Johnson, C.E.; Henyey, T.L.; Yerkes, R.L.

    1978-01-01

    The ML5.1 Santa Barbara earthquake of August 13, 1978 occurred at lat 34 ? 22.2'N., long 119 ? 43.0' 4 km south of Santa Barbara, Calif. at a depth of 12.5 km in the northeast Santa Barbara Channel, part of the western Transverse Ranges geomorphic-structural province. This part of the province is characterized by seismically active, east-trending reverse faults and rates of coastal uplift that have averaged up to about 10 m/1000 years over the last 45,000 years. No surface rupture was detected onshore. Subsurface rupture propagated northwest from the main shock toward Goleta, 15 km west of Santa Barbara, where a maximum acceleration of 0.44 g was measured at ground level and extensive minor damage occurred; only minor injuries were reported. A fairly well-constrained fault-plane solution of the main shock and distribution of the aftershocks indicate that left-reverse-oblique slip occurred on west-northwest-trending, north-dipping reverse faults; inadequate dip control precludes good correlation with any one of several mapped faults. Had the earthquake been larger and rupture propagated to the southeast or a greater distance to the northwest, it could have posed a hazard to oilfield operations. The fault-plane solution and aftershock pattern closely fit the model of regional deformation and the solution closely resembles those of five previously mapped events located within a 15-km radius.

  15. Measurement of radon gas on major faults in California, USA

    USGS Publications Warehouse

    Zhang, W.; King, C.-Y.

    1994-01-01

    Abundant data have been gathered through measurements of radon gas emission in the soil on several major active faults, such as San Andreas and Calaveras, in California, U.S.A.. They show radon emissions and their spatial variations at the unlocked, locked, and creeping sections of faults with different tectonic movements. The characteristics of these variations and the role of fault gases in the research on earthquake prediction are discussed in this paper. ?? 1994 Acta Seismologica Sinica.

  16. Tracking Identity: Opportunity, Success, and Affiliation with Science among Fifth-Grade Latina/o Youth of Santa Barbara, California

    NASA Astrophysics Data System (ADS)

    Maas, Grayson Ford

    This dissertation is an investigation into the American public education system at the elementary school level. It highlights important factors that shape the organizational structure of schools and classrooms, and in turn, how they engender disparities in the ways students experience education, namely, in the opportunities made available to them to achieve and succeed at a high level. This dissertation operates at the confluence of notions about class, gender, language, and race, especially as they revolve around public education and the hegemonic meritocratic discourse on which it is founded. This dissertation engages and contributes to scholarship within the following areas: The political economy of education; discourse and the dialectical relationship between agency and structure; cultural perspectives on identity, voice, and learning; and, Latinas/os in science education. The data that serve as the basis for the findings presented in this dissertation were collected throughout a three-phase yearlong ethnographic study of the two tracked fifth-grade classrooms at Amblen Elementary School, serving a socioeconomically disadvantaged Latina/o student population in Santa Barbara, California. In classrooms all across the nation, while it remains true that Latina/o students disproportionally take up space in the lower-tracked courses and not in the higher ones, this study does not examine inequality in tracking assignments made along ethnic/racial lines (as 100% of the students that participated in this research identify as Latina/o), rather, it investigates the consequences of what happens when Latina/o students are tracked according to symbolic markers of their ethnic/racial identity, that is, their varying levels of English language competency. Using data from participant observation, semi-structured interviews, students' drawings, as well as free-list and rank-order exercises, I was able to answer the following central research questions: In what ways do the

  17. WIMP Dark Matter Limit-Direct Detection Data and Sensitivity Plots from the Cryogenic Dark Matter Search II and the University of California at Santa Barbara

    DOE Data Explorer

    Expectations for non-baryonic dark matter are founded principally in Big Bang nucleosynthesis calculations, which indicate that the missing mass of the universe is not likely to be baryonic. The supersymmetric standard model (SUSY) offers a promising framework for expectations of particle species which could satisfy the observed properties of dark matter. WIMPs are the most likely SUSY candidate for a dark matter particle. The High Energy Physics Group at University of California, Santa Barbara, is part of the CDMSII Collaboration and have provided the Interactive Plotter for WIMP Dark Matter Limit-Direct Detection Data on their website. They invite other collaborations working on dark matter research to submit datasets and, as a result, have more than 150 data sets now available for use with the plotting tool. The published source of the data is provided with each data set.

  18. Prehistoric fires and the shaping of colonial transported landscapes in southern California: A paleoenvironmental study at Dune Pond, Santa Barbara County

    NASA Astrophysics Data System (ADS)

    Ejarque, Ana; Anderson, R. Scott; Simms, Alexander R.; Gentry, Beau J.

    2015-03-01

    Using a novel combination of paleoecologic proxies including pollen, non-pollen palynomorphs (NPPs), macroscopic charcoal, and Spheroidal Carbonaceous Particles (SCPs), 5000 years of landscape change, fire history and land-use have been reconstructed from Dune Pond, Santa Barbara County, California. The pond was sensitive to Holocene regional climatic variability, showing different phases of lower (4600-3700 cal yr BP, 2100-700 cal yr BP, historical period) and higher (3700-2100 cal yr BP, 700-150 cal yr BP) local moisture availability. During this period the landscape was dominated by a coastal mosaic vegetation including dune mats, coastal scrub and salt marshes on the dunes and backdunes, with chaparral and oak woodland growing in the valley plains and foothills. Fire was intimately linked with such dominating mosaic vegetation, and the combination of wet conditions and the presence of nearby human settlement were a trigger favoring coastal fires for at least two periods: from 3100 to 1500 cal yr BP and from 650 cal yr BP until the 18th century. In both cases fire was an important tool to keep an open coastal landscape attractive to hunting wildlife. Finally, matching this varied range of high-resolution paleoecological proxies with historical records we could characterize the development of colonial transported landscapes following the Euro-American settlement of Santa Barbara. The introduction of livestock grazing by Spanish colonists favored erosive processes and the introduction of fecal-borne parasites in freshwater bodies, negatively impacted salt and brackish coastal marshes, and promoted the invasion of alien grasses and ruderals. This agro-pastoral landscape was consolidated during the American period, with a greater role for cultivation, the development of industrial activities and increased population. Despite negative environmental consequences such as the loss of native habitats, exotic land-uses and plants introduced during the historical period

  19. ChE at UC Santa Barbara.

    ERIC Educational Resources Information Center

    Seborg, Dale E.

    1981-01-01

    Describes the chemical engineering program at the University of California, Santa Barbara, including history of the department, faculty research interests and professional activities, graduate and undergraduate programs, and research in nuclear engineering. (SK)

  20. A study of the TEX86 paleothermometer in the water column and sediments of the Santa Barbara Basin, California

    NASA Astrophysics Data System (ADS)

    Huguet, Carme; Schimmelmann, Arndt; Thunell, Robert; Lourens, Lucas J.; Sinninghe Damsté, Jaap S.; Schouten, Stefan

    2007-09-01

    Particulate organic matter collected during a 2-year period, as part of an ongoing sediment trap study, and a high-resolution sediment record from 1850 to 1987 A.D. from the Santa Barbara Basin were analyzed for TEX86, a temperature proxy based on marine crenarchaeotal membrane lipids. Highest fluxes of crenarchaeotal lipids in the water column were found in May-June 1996 and from October 1996 to January 1997 and, in general, showed a good correlation with mass fluxes. TEX86 reconstructed temperatures from the sediment trap series ranged from 8 to 11°C and were usually substantially lower than sea surface temperatures (SST), indicating that unlike in previous studies, the TEX86 corresponds to subsurface temperatures, likely between 100 and 150 m. TEX86 temperature variations observed in trap samples were not coupled to changes in SST or deep-water temperatures and only to some degree with crenarchaeotal lipid fluxes. This suggests that a complex combination of different depth origins and seasonal growth periods of Crenarchaeota contributed to the variations in TEX86 signal during the annual cycle. TEX86 temperatures in the two sediment cores studied (8-13°C) were also substantially lower than those of instrumental SST records (14-17.5°C) confirming that TEX86 records a subsurface temperature signal in the Santa Barbara Basin. This result highlights the importance of performing calibration studies using sediment traps and core tops before applying the TEX86 temperature proxy in a given study area.

  1. Brief communication: Additional cases of maxillary canine-first premolar transposition in several prehistoric skeletal assemblages from the Santa Barbara Channel Islands of California.

    PubMed

    Sholts, Sabrina B; Clement, Anna F; Wärmländer, Sebastian K T S

    2010-09-01

    This article identifies and discusses seven new cases of complete maxillary canine-premolar transposition in ancient populations from the Santa Barbara Channel region of California. A high frequency of this tooth transposition has been previously documented within a single prehistoric cemetery on one of the Channel Islands. A total of 966 crania representing 30 local sites and about 7,000 years of human occupation were examined, revealing an abnormally high prevalence of this transposition trait among islanders during the Early period of southern California prehistory ( approximately 5500-600 B.C.). One of the affected crania is from a cemetery more than 7,000-years-old and constitutes the earliest case of tooth transposition in humans so far reported. The results are consistent with findings by other studies that have indicated inbreeding among the early Channel Islands groups. Together with the normal transposition rates among mainland populations, the decreasing prevalence of maxillary canine-first premolar transposition among island populations across the Holocene suggests that inbreeding on the northern Channel Islands had all but ceased by the end of the first millennium B.C., most likely as a result of increased cross-channel migration and interaction.

  2. Geochemical characterization of tarballs on beaches along the California coast. Part I - Shallow seepage impacting the Santa Barbara Channel Islands, Santa Cruz, Santa Rosa and San Miguel

    USGS Publications Warehouse

    Hostettler, F.D.; Rosenbauer, R.J.; Lorenson, T.D.; Dougherty, J.

    2004-01-01

    Tarballs are common along the southern California coastline. This study investigates tarballs from beaches along this coastline, with a focus on Santa Cruz, Santa Rosa, and San Miquel Islands in the Santa Barbara Channel. The tarballs were fingerprinted using biomarker and stable carbon isotope parameters, and then grouped according to genetic similarities. The data show that the tarballs are of natural and not anthropogenic origin and that all originate from source rock within the Miocene Monterey Formation via shallow seeps offshore. Sterane biomarker parameters were found to vary widely in the sample set. Biodegradation, especially of the regular steranes, is the primary process impacting the biomarker distributions in a large group of samples. The most common tarball occurrences appear to come from offshore seepage near the west end of Santa Cruz Island. Another major group most likely was transported north from near Santa Monica Bay. Several individual occurrences of some of these tarball groups also were found on beaches as far north as Pt. Reyes and as far south as San Diego, indicating significant long-distance dispersal by ocean currents. This study begins a library of tarball fingerprints to be used as a database to help distinguish between natural and anthropogenic tar occurrences all along the California coast, and to compare shallow seepage with future samples of deeper production oils from the same area.

  3. Microplastic contamination in the San Francisco Bay, California, USA.

    PubMed

    Sutton, Rebecca; Mason, Sherri A; Stanek, Shavonne K; Willis-Norton, Ellen; Wren, Ian F; Box, Carolynn

    2016-08-15

    Despite widespread detection of microplastic pollution in marine environments, data describing microplastic abundance in urban estuaries and microplastic discharge via treated municipal wastewater are limited. This study presents information on abundance, distribution, and composition of microplastic at nine sites in San Francisco Bay, California, USA. Also presented are characterizations of microplastic in final effluent from eight wastewater treatment plants, employing varying treatment technologies, that discharge to the Bay. With an average microplastic abundance of 700,000particles/km(2), Bay surface water appears to have higher microplastic levels than other urban waterbodies sampled in North America. Moreover, treated wastewater from facilities that discharge into the Bay contains considerable microplastic contamination. Facilities employing tertiary filtration did not show lower levels of contamination than those using secondary treatment. As textile-derived fibers were more abundant in wastewater, higher levels of fragments in surface water suggest additional pathways of microplastic pollution, such as stormwater runoff.

  4. Natural Offshore Oil Seepage and Related Tarball Accumulation on the California Coastline - Santa Barbara Channel and the Southern Santa Maria Basin: Source Identification and Inventory

    USGS Publications Warehouse

    Lorenson, T.D.; Hostettler, Frances D.; Rosenbauer, Robert J.; Peters, Kenneth E.; Dougherty, Jennifer A.; Kvenvolden, Keith A.; Gutmacher, Christina E.; Wong, Florence L.; Normark, William R.

    2009-01-01

    Oil spillage from natural sources is very common in the waters of southern California. Active oil extraction and shipping is occurring concurrently within the region and it is of great interest to resource managers to be able to distinguish between natural seepage and anthropogenic oil spillage. The major goal of this study was to establish the geologic setting, sources, and ultimate dispersal of natural oil seeps in the offshore southern Santa Maria Basin and Santa Barbara Basins. Our surveys focused on likely areas of hydrocarbon seepage that are known to occur between Point Arguello and Ventura, California. Our approach was to 1) document the locations and geochemically fingerprint natural seep oils or tar; 2) geochemically fingerprint coastal tar residues and potential tar sources in this region, both onshore and offshore; 3) establish chemical correlations between offshore active seeps and coastal residues thus linking seep sources to oil residues; 4) measure the rate of natural seepage of individual seeps and attempt to assess regional natural oil and gas seepage rates; and 5) interpret the petroleum system history for the natural seeps. To document the location of sub-sea oil seeps, we first looked into previous studies within and near our survey area. We measured the concentration of methane gas in the water column in areas of reported seepage and found numerous gas plumes and measured high concentrations of methane in the water column. The result of this work showed that the seeps were widely distributed between Point Conception east to the vicinity of Coal Oil Point, and that they by in large occur within the 3-mile limit of California State waters. Subsequent cruises used sidescan and high resolution seismic to map the seafloor, from just south of Point Arguello, east to near Gaviota, California. The results of the methane survey guided the exploration of the area west of Point Conception east to Gaviota using a combination of seismic instruments. The

  5. Map of the Carpinteria area and vicinity, Santa Barbara County, California, showing water-level contours for March 1982

    USGS Publications Warehouse

    Maltby, Dorothy

    1984-01-01

    A water-level contour map of the Carpinteria area, California, has been completed by the U.S. Geological Survey using 34 water-level measurements made by the Carpinteria County Water District in March 1982. Also shown are 5 hydrographs that show water-level fluctuations in each well between 1977 and 1982. (USGS)

  6. A Geomorphic Investigation of the Tectonic Transition between the Santa Barbara and Ventura Fold Belts near Rincon Point, California

    NASA Astrophysics Data System (ADS)

    Fredrickson, S. M.; Keller, E. A.

    2015-12-01

    The Santa Barbara and Ventura Fold Belts have very different uplift rates: ~1-2 m/ky and ~6-8 m/ky, respectively. Differences are probably related to the position of the two belts relative to the big bend of the San Andreas fault. The onshore transition between these fold belts occurs at Rincon Creek, near Carpinteria. We use a combination of geomorphology and geochronology to describe patterns and rates of crustal deformation near Rincon Creek and test whether the known change in uplift rate is spatially discrete or distributed across the transition zone.Five sediment samples from the first emergent marine terrace between Carpinteria and Rincon Creek are being processed for optically stimulated luminescence (OSL) dating. We expect the age of this terrace to be either MIS 3 or MIS 5. An age of MIS 3 will suggest that the terrace is continuous with the Punta Gorda terrace across Rincon Creek. An age of MIS 5 will suggest that a geologic discontinuity exists across Rincon Creek, supporting the existence of a cross-fault at Rincon Creek. Terrace chronology will also help constrain the growth rate of the Rincon Creek anticline and the slip rates of several faults that vertically displace the marine terrace.Uplift patterns may be inferred from stream profile analysis via digital topography. Preliminary analysis of normalized stream steepness indices and stream concavities from Carpinteria to La Conchita indicate a gradational change in uplift rate rather than a sharp transition at Rincon Creek. Chi analysis and knickpoint identification are in progress and will also help delineate patterns of uplift.

  7. Residential Mobility and Breast Cancer in Marin County, California, USA

    PubMed Central

    Jacquez, Geoffrey M.; Barlow, Janice; Rommel, Robert; Kaufmann, Andy; Rienti, Michael; AvRuskin, Gillian; Rasul, Jawaid

    2013-01-01

    Marin County (California, USA) has among the highest incidences of breast cancer in the U.S. A previously conducted case-control study found eight significant risk factors in participants enrolled from 1997–1999. These included being premenopausal, never using birth control pills, lower highest lifetime body mass index, having four or more mammograms from 1990–1994, beginning drinking alcohol after age 21, drinking an average two or more alcoholic drinks per day, being in the highest quartile of pack-years of cigarette smoking, and being raised in an organized religion. Previously conducted surveys provided residential histories; while Ǫ statistic accounted for participants’ residential mobility, and assessed clustering of breast cancer cases relative to controls based on the known risk factors. These identified specific cases, places, and times of excess breast cancer risk. Analysis found significant global clustering of cases localized to specific residential histories and times. Much of the observed clustering occurred among participants who immigrated to Marin County. However, persistent case-clustering of greater than fifteen years duration was also detected. Significant case-clustering among long-term residents may indicate geographically localized risk factors not accounted for in the study design, as well as uncertainty and incompleteness in the acquired addresses. Other plausible explanations include environmental risk factors and cases tending to settle in specific areas. A biologically plausible exposure or risk factor has yet to be identified. PMID:24366047

  8. 78 FR 25740 - Meridian Energy USA, Inc. v. California Independent System Operator Corporation; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-02

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Meridian Energy USA, Inc. v. California Independent System Operator Corporation; Notice of Filing Take notice that on April 24, 2013, Meridian Energy USA, Inc....

  9. Development of Multiscale Biological Image Data Analysis: Review of 2006 International Workshop on Multiscale Biological Imaging, Data Mining and Informatics, Santa Barbara, USA (BII06)

    PubMed Central

    Auer, Manfred; Peng, Hanchuan; Singh, Ambuj

    2007-01-01

    The 2006 International Workshop on Multiscale Biological Imaging, Data Mining and Informatics was held at Santa Barbara, on Sept 7–8, 2006. Based on the presentations at the workshop, we selected and compiled this collection of research articles related to novel algorithms and enabling techniques for bio- and biomedical image analysis, mining, visualization, and biology applications. PMID:17634090

  10. A History of Warming Sea Surface Temperature and Ocean Acidification Recorded by Planktonic Foraminifera Geochemistry from the Santa Barbara Basin, California

    NASA Astrophysics Data System (ADS)

    Osborne, E.; Thunell, R.; Bizimis, M.; Buckley, W. P., Jr.; benitez-Nelson, C. R.; Chartier, C. J.

    2015-12-01

    The geochemistry of foraminiferal shells has been widely used to reconstruct past conditions of the ocean and climate. Since the onset of the Industrial Revolution, anthropogenically produced CO2 has resulted in an increase in global temperatures and a decline in the mean pH of the world's oceans. The California Current System is a particularly susceptible region to ocean acidification due to natural upwelling processes that also cause a reduction in seawater pH. The trace element concentration of magnesium and boron in planktonic foraminiferal shells are used here as proxies for temperature and carbonate ion concentration ([CO32-]), respectively. Newly developed calibrations relating Mg/Ca ratios to temperature (R2 0.91) and B/Ca ratios to [CO32-] (R2 0.84) for the surface-mixed layer species Globogerina bulloides were generated using material collected in the Santa Barbara Basin sediment trap time-series. Using these empirical relationships, temperature and [CO32-] are reconstructed using a 0.5 meter long multi-core collected within the basin. 210Pb activities were used to determine a sedimentation rate for the core to estimate ages for core samples (sedimentation rate: 0.341 cm/yr). A spike in 137Cs activity is used as a tie-point to the year 1965 coinciding with the peak of nuclear bomb testing. Our down-core record extends through the mid-19th century to create a history of rising sea surface temperatures and declining [CO32-] as a result of anthropogenic CO2 emissions.

  11. Were fossil spring-associated carbonates near Zaca Lake, Santa Barbara, California deposited under an ambient or thermal regime?

    NASA Astrophysics Data System (ADS)

    Ibarra, Yadira; Corsetti, Frank A.; Cheetham, Michael I.; Feakins, Sarah J.

    2014-03-01

    A previously undescribed succession of currently-inactive spring-associated carbonates located near Zaca Lake, Southern California, was investigated in order to determine the nature of deposition (ambient temperature or hydrothermal water, as both are found within the region). The carbonate deposits are up to ~ 1 m thick and formed discontinuously for over 200 m in a narrow valley between two ridges that drain Miocene Monterey Formation bedrock. Depositional facies along the presently dry fluvial path include barrage deposits, narrow fluvial channels, and cascade deposits. The carbonates are mesoscopically banded and contain ubiquitous micro- to macrophyte calcite encrusted fabrics. All of the depositional facies contain alternating bands (~ .05 mm to 5 mm thick) of dark brown and light brown isopachous calcite; the dark brown bands are composed of dense isopachous bladed calcite, whereas the light brown bands are composed of bundles of calcite tubules interpreted as the biosignature of the desmid microalgae Oocardium stratum. Oxygen isotope thermometry utilizing modern water δ18O values from the piped spring reveal depositional water temperature estimates that collectively range from ~ 11 to 16 °C. Stable isotope carbon values exhibit a mean δ13C value of - 9.01 ± 0.62‰ (1σ, n = 27). Our petrographic and geochemical data demonstrate that (1) inactive carbonates were likely sourced from ambient temperature water with a strong soil-zone δ13C signal, (2) the Oocardium calcite biosignature can be used to infer depositional temperature and flow conditions, and (3) the occurrence of extensive carbonates (especially the presence of a perched cascade deposit) indicate the carbonates formed when conditions were much wetter.

  12. Environmental Law Series Links Campus and Community in Santa Barbara.

    ERIC Educational Resources Information Center

    McGinnes, J. Marc

    1981-01-01

    Describes a three-course series in environmental law developed at the University of California, Santa Barbara as part of the undergraduate Environmental Studies Program. The series progresses from theory to simulation to field experience. (Author/WB)

  13. Description of the larvae of Nothotrichia shasta Harris and Armitage (Trichoptera: Hydroptilidae) from California, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nothotrichia Flint is a small genus of infrequently collected microcaddisflies that are amphitropical in distribution. Previously only known from adult specimens, the first description and illustration of larvae in the genus, N. shasta from California, USA is presented. We provide characters to sepa...

  14. Habitat Effects on Population Density and Movement of Insect Vectors of Xylella fastidiosa in California, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Xylella fastidiosa is a xylem-limited bacterium that causes disease in grapevines, almonds, citrus, pear, alfalfa, and many other economically important plants. In California, USA, the bacteria are transmitted by several species of leafhoppers including the cicadellids Draeculacephala minerva Ball a...

  15. Emissions calculated from particulate matter and gaseous ammonia measurements from a commercial dairy in California, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Emission rates and factors for particulate matter (PM) and gaseous ammonia (NH3) were estimated from measurements taken at a dairy in California, USA in June 2008. Concentration measurements were made using both point and remote sensors. Filter-based PM samplers and OPCs characterized aerodynamic an...

  16. A draft genome sequence of “Candidatus Liberibacter asiaticus” from California, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The draft genome sequence of “Candidatus Liberibacter asiaticus” strain HHCA, collected from a lemon tree in California, USA, is reported. The HHCA strain has a genome size of 1,118,244 bp, with G+C content of 36.6%. The HHCA genome encodes 1,191 predicted open reading frames and 51 RNA genes....

  17. Second progress report on the cooperative investigation of springs and stream flow in the Tecolote Tunnel area of Santa Barbara County, California

    USGS Publications Warehouse

    Troxell, Harold C.; Burgess, C.E.

    1950-01-01

    This report represents the second of a series of progress reports giving the results of discharge measurements made at more than 100 locations in the Santa Ynez Mountains from the Refugio Canyon on the west to the San Marcos Pass and Painted Cave area on the east. The flow in all the developed springs and headwater streams within this area, here designated as the Tecolote Tunnel Area of the purpose of this report, is generally measured monthly. The primary purpose of this second progress report is to make available to the public all factual data regarding the flow at these locations obtained since the preparation of the first progress report, issued in May 1949. Near the mid-point of this area the Bureau of Reclamation and the Santa Barbara County Water Agency proposed a tunnel, known as Tecolote Tunnel, for the purpose of diverting a portion of the runoff of the Santa Ynez River drainage area into water-deficient Santa Barbara and the coastal areas to the east and west, Because the water users of the mountain springs in the Tecolote Tunnel Area are somewhat apprehensive as to the influence this tunnel may have on their present water supply, the Santa Barbara Water Agency has requested the Geological Survey to obtain records of flow in their springs at frequent and regular intervals. During the current fiscal year these observations have been made as a result of a cooperative agreement between the Geological Survey and the Santa Barbara County Water Agency whereby each paid half the cost of the investigation. During the previous fiscal year all the costs to the Geological Survey in obtaining these observations were completely reimbursed by the Bureau of Reclamation.

  18. Ground-water monitoring at Santa Barbara, California; Phase 3, development of a three-dimensional digital ground-water flow model for storage unit I of the Santa Barbara ground-water basin

    USGS Publications Warehouse

    Martin, Peter; Berenbrock, Charles

    1986-01-01

    Water-bearing rocks within the 7 sq mi of Storage Unit I of the Santa Barbara Groundwater Basin, consist of unconsolidated deposits that range in thickness from < 300 ft along the north perimeter of the unit to > 1,000 ft near the Pacific Ocean. The groundwater system was simulated as two horizontal layers separated by a confining bed. The model boundaries coincide with mapped faults on all sides. The faults were considered no-flow boundaries except for the offshore fault that forms the south boundary. This boundary was simulated as a general-head boundary , which allows water to move into and out of the modeled area. The model was calibrated by simulating both steady-state conditions (approximated by July 1978 and February 1983 water levels) and transient-state conditions (represented by May 1978 through December 1979 water level changes). The calibrated model was then used to simulate the period from January 1980 through December 1983 in order to verify the model. Model results generally closely matched measured data throughout Storage Unit I. During the transient and verification simulations, 9,980 acre-ft of groundwater was pumped from Storage Unit I for municipal use. Results of the model indicate that 42% (4,190 acre-ft) of the water pumped from the system was withdrawn from storage, 33% (3,290 acre-ft) was derived from changes in underflow across the offshore fault, and 25% (2,500 acre-ft) was derived from decreased groundwater discharge to drains. The model simulated that municipal pumpage induced about 1,380 acre-ft of water to move across the offshore fault toward Storage Unit I. Several model simulations were used to estimate aquifer response to different municipal pumpage patterns that could be used as management alternatives. Results of the simulations indicate that spreading municipal pumpage more evenly throughout Storage Unit I, by increasing the number of wells while reducing the pumping rate at the individual wells to maintain the same total

  19. Effects of Groundwater Development on Uranium: Central Valley, California, USA

    USGS Publications Warehouse

    Jurgens, Bryant C.; Fram, Miranda S.; Belitz, Kenneth; Burow, Karen R.; Landon, Matthew K.

    2009-01-01

    Uranium (U) concentrations in groundwater in several parts of the eastern San Joaquin Valley, California, have exceeded federal and state drinking water standards during the last 20 years. The San Joaquin Valley is located within the Central Valley of California and is one of the most productive agricultural areas in the world. Increased irrigation and pumping associated with agricultural and urban development during the last 100 years have changed the chemistry and magnitude of groundwater recharge, and increased the rate of downward groundwater movement. Strong correlations between U and bicarbonate suggest that U is leached from shallow sediments by high bicarbonate water, consistent with findings of previous work in Modesto, California. Summer irrigation of crops in agricultural areas and, to lesser extent, of landscape plants and grasses in urban areas, has increased Pco2 concentrations in the soil zone and caused higher temperature and salinity of groundwater recharge. Coupled with groundwater pumping, this process, as evidenced by increasing bicarbonate concentrations in groundwater over the last 100 years, has caused shallow, young groundwater with high U concentrations to migrate to deeper parts of the groundwater system that are tapped by public-supply wells. Continued downward migration of U-affected groundwater and expansion of urban centers into agricultural areas will likely be associated with increased U concentrations in public-supply wells. The results from this study illustrate the potential longterm effects of groundwater development and irrigation-supported agriculture on water quality in arid and semiarid regions around the world.

  20. Effects of groundwater development on uranium: Central Valley, California, USA.

    PubMed

    Jurgens, Bryant C; Fram, Miranda S; Belitz, Kenneth; Burow, Karen R; Landon, Matthew K

    2010-01-01

    Uranium (U) concentrations in groundwater in several parts of the eastern San Joaquin Valley, California, have exceeded federal and state drinking water standards during the last 20 years. The San Joaquin Valley is located within the Central Valley of California and is one of the most productive agricultural areas in the world. Increased irrigation and pumping associated with agricultural and urban development during the last 100 years have changed the chemistry and magnitude of groundwater recharge, and increased the rate of downward groundwater movement. Strong correlations between U and bicarbonate suggest that U is leached from shallow sediments by high bicarbonate water, consistent with findings of previous work in Modesto, California. Summer irrigation of crops in agricultural areas and, to lesser extent, of landscape plants and grasses in urban areas, has increased Pco(2) concentrations in the soil zone and caused higher temperature and salinity of groundwater recharge. Coupled with groundwater pumping, this process, as evidenced by increasing bicarbonate concentrations in groundwater over the last 100 years, has caused shallow, young groundwater with high U concentrations to migrate to deeper parts of the groundwater system that are tapped by public-supply wells. Continued downward migration of U-affected groundwater and expansion of urban centers into agricultural areas will likely be associated with increased U concentrations in public-supply wells. The results from this study illustrate the potential long-term effects of groundwater development and irrigation-supported agriculture on water quality in arid and semiarid regions around the world.

  1. Range and Frequency of Africanized Honey Bees in California (USA).

    PubMed

    Kono, Yoshiaki; Kohn, Joshua R

    2015-01-01

    Africanized honey bees entered California in 1994 but few accounts of their northward expansion or their frequency relative to European honey bees have been published. We used mitochondrial markers and morphometric analyses to determine the prevalence of Africanized honeybees in San Diego County and their current northward progress in California west of the Sierra Nevada crest. The northernmost African mitotypes detected were approximately 40 km south of Sacramento in California's central valley. In San Diego County, 65% of foraging honey bee workers carry African mitochondria and the estimated percentage of Africanized workers using morphological measurements is similar (61%). There was no correlation between mitotype and morphology in San Diego County suggesting Africanized bees result from bidirectional hybridization. Seventy percent of feral hives, but only 13% of managed hives, sampled in San Diego County carried the African mitotype indicating that a large fraction of foraging workers in both urban and rural San Diego County are feral. We also found a single nucleotide polymorphism at the DNA barcode locus COI that distinguishes European and African mitotypes. The utility of this marker was confirmed using 401 georeferenced honey bee sequences from the worldwide Barcode of Life Database. Future censuses can determine whether the current range of the Africanized form is stable, patterns of introgression at nuclear loci, and the environmental factors that may limit the northern range of the Africanized honey bee.

  2. Late Pleistocene to Holocene sedimentation and hydrocarbon seeps on the continental shelf of a steep, tectonically active margin, southern California, USA

    USGS Publications Warehouse

    Draut, Amy E.; Hart, Patrick E.; Lorenson, T.D.; Ryan, Holly F.; Wong, Florence L.; Sliter, Ray W.; Conrad, James E.

    2009-01-01

    Small, steep, uplifting coastal watersheds are prolific sediment producers that contribute significantly to the global marine sediment budget. This study illustrates how sedimentation evolves in one such system where the continental shelf is largely sediment-starved, with most terrestrial sediment bypassing the shelf in favor of deposition in deeper basins. The Santa Barbara-Ventura coast of southern California, USA, is considered a classic area for the study of active tectonics and of Tertiary and Quaternary climatic evolution, interpretations of which depend upon an understanding of sedimentation patterns. High-resolution seismic-reflection data over >570 km2 of this shelf show that sediment production is concentrated in a few drainage basins, with the Ventura and Santa Clara River deltas containing most of the upper Pleistocene to Holocene sediment on the shelf. Away from those deltas, the major factor controlling shelf sedimentation is the interaction of wave energy with coastline geometry. Depocenters containing sediment 5-20 m thick exist opposite broad coastal embayments, whereas relict material (bedrock below a regional unconformity) is exposed at the sea floor in areas of the shelf opposite coastal headlands. Locally, natural hydrocarbon seeps interact with sediment deposition either to produce elevated tar-and-sediment mounds or as gas plumes that hinder sediment settling. As much as 80% of fluvial sediment delivered by the Ventura and Santa Clara Rivers is transported off the shelf (some into the Santa Barbara Basin and some into the Santa Monica Basin via Hueneme Canyon), leaving a shelf with relatively little recent sediment accumulation. Understanding factors that control large-scale sediment dispersal along a rapidly uplifting coast that produces substantial quantities of sediment has implications for interpreting the ancient stratigraphic record of active and transform continental margins, and for inferring the distribution of hydrocarbon resources

  3. Variations in archaeal and bacterial diversity associated with the sulfate-methane transition zone in continental margin sediments (Santa Barbara Basin, California).

    PubMed

    Harrison, Benjamin K; Zhang, Husen; Berelson, Will; Orphan, Victoria J

    2009-03-01

    The sulfate-methane transition zone (SMTZ) is a widespread feature of continental margins, representing a diffusion-controlled interface where there is enhanced microbial activity. SMTZ microbial activity is commonly associated with the anaerobic oxidation of methane (AOM), which is carried out by syntrophic associations between sulfate-reducing bacteria and methane-oxidizing archaea. While our understanding of the microorganisms catalyzing AOM has advanced, the diversity and ecological role of the greater microbial assemblage associated with the SMTZ have not been well characterized. In this study, the microbial diversity above, within, and beneath the Santa Barbara Basin SMTZ was described. ANME-1-related archaeal phylotypes appear to be the primary methane oxidizers in the Santa Barbara Basin SMTZ, which was independently supported by exclusive recovery of related methyl coenzyme M reductase genes (mcrA). Sulfate-reducing Deltaproteobacteria phylotypes affiliated with the Desulfobacterales and Desulfosarcina-Desulfococcus clades were also enriched in the SMTZ, as confirmed by analysis of dissimilatory sulfite reductase (dsr) gene diversity. Statistical methods demonstrated that there was a close relationship between the microbial assemblages recovered from the two horizons associated with the geochemically defined SMTZ, which could be distinguished from microbial diversity recovered from the sulfate-replete overlying horizons and methane-rich sediment beneath the transition zone. Comparison of the Santa Barbara Basin SMTZ microbial assemblage to microbial assemblages of methane seeps and other organic matter-rich sedimentary environments suggests that bacterial groups not typically associated with AOM, such as Planctomycetes and candidate division JS1, are additionally enriched within the SMTZ and may represent a common bacterial signature of many SMTZ environments worldwide.

  4. Blue oak plant communities of southern San Luis Obispo and northern Santa Barbara Counties, California. Forest Service general technical report (Final)

    SciTech Connect

    Borchert, M.I.; Cunha, N.D.; Krosse, P.C.; Lawrence, M.L.

    1993-02-01

    An ecological classification system has been developed for the Pacific Southwest Region of the Forest Service. As part of that classification effort, blue oak (Quercus douglasii) woodlands and forests of southern San Luis Obispo and northern Santa Barbara Counties in Los Padres National Forest were classified into 13 plant communities using vegetation collected from 208 plots, 0.1 acre each. Three distinct regions of vegetation were identified in the study area: Avenales, Miranda Pine Mountain and Branch Mountain. Communities were classified separately for plots in each region. Each region has a woodland community that occupies flat or gently sloping benches, toeslopes, and valley bottoms.

  5. Effects of Groundwater Development on Uranium: Central Valley, California, USA

    USGS Publications Warehouse

    Jurgens, B.C.; Fram, M.S.; Belitz, K.; Burow, K.R.; Landon, M.K.

    2010-01-01

    Uranium (U) concentrations in groundwater in several parts of the eastern San Joaquin Valley, California, have exceeded federal and state drinking water standards during the last 20 years. The San Joaquin Valley is located within the Central Valley of California and is one of the most productive agricultural areas in the world. Increased irrigation and pumping associated with agricultural and urban development during the last 100 years have changed the chemistry and magnitude of groundwater recharge, and increased the rate of downward groundwater movement. Strong correlations between U and bicarbonate suggest that U is leached from shallow sediments by high bicarbonate water, consistent with findings of previous work in Modesto, California. Summer irrigation of crops in agricultural areas and, to lesser extent, of landscape plants and grasses in urban areas, has increased Pco2 concentrations in the soil zone and caused higher temperature and salinity of groundwater recharge. Coupled with groundwater pumping, this process, as evidenced by increasing bicarbonate concentrations in groundwater over the last 100 years, has caused shallow, young groundwater with high U concentrations to migrate to deeper parts of the groundwater system that are tapped by public-supply wells. Continued downward migration of U-affected groundwater and expansion of urban centers into agricultural areas will likely be associated with increased U concentrations in public-supply wells. The results from this study illustrate the potential long-term effects of groundwater development and irrigation-supported agriculture on water quality in arid and semiarid regions around the world. Journal compilation ?? 2009 National Ground Water Association. No claim to original US government works.

  6. Temporal and Spatial Variation of Atmospherically Deposited Organic Contaminants at High Elevation in Yosemite National Park, California, USA

    EPA Science Inventory

    Atmospherically deposited organic contaminants in the Sierra Nevada mountains of California, USA, have exceeded some thresholds of concern, but the spatial and temporal distributions of contaminants in the mountains are not well known. The present study evaluated (1) whether the...

  7. Range and Frequency of Africanized Honey Bees in California (USA)

    PubMed Central

    Kono, Yoshiaki; Kohn, Joshua R.

    2015-01-01

    Africanized honey bees entered California in 1994 but few accounts of their northward expansion or their frequency relative to European honey bees have been published. We used mitochondrial markers and morphometric analyses to determine the prevalence of Africanized honeybees in San Diego County and their current northward progress in California west of the Sierra Nevada crest. The northernmost African mitotypes detected were approximately 40 km south of Sacramento in California’s central valley. In San Diego County, 65% of foraging honey bee workers carry African mitochondria and the estimated percentage of Africanized workers using morphological measurements is similar (61%). There was no correlation between mitotype and morphology in San Diego County suggesting Africanized bees result from bidirectional hybridization. Seventy percent of feral hives, but only 13% of managed hives, sampled in San Diego County carried the African mitotype indicating that a large fraction of foraging workers in both urban and rural San Diego County are feral. We also found a single nucleotide polymorphism at the DNA barcode locus COI that distinguishes European and African mitotypes. The utility of this marker was confirmed using 401 georeferenced honey bee sequences from the worldwide Barcode of Life Database. Future censuses can determine whether the current range of the Africanized form is stable, patterns of introgression at nuclear loci, and the environmental factors that may limit the northern range of the Africanized honey bee. PMID:26361047

  8. The marine geology of the eastern Santa Barbara Channel, with particular emphasis on the ground water basins offshore from the Oxnard Plain, Southern California

    USGS Publications Warehouse

    Greene, H. Gary; Wolf, Stephen C.; Blom, Ken G.

    1978-01-01

    Marine geophysical investigations provide new data concerning the stratigraphy, tectonic and sedimentary history, and the ground water geology of the southeastern Santa Barbara Channel region. The offshore stratigraphy identified in seismic reflection profiles includes a succession of Neogene to Quaternary strata. The middle Miocene Conejo volcanics form an acoustical basement and the overlying late Cenozoic sedimentary rocks attain a thickness greater than 2,500 m. These sedimentary deposits fill a structurally controlled, physiographic and depositional depression called the Ventura Basin. Structure consists generally of a gently folded, east-trending Tertiary synclinorium bordered on the north by a regional thrust fault and on the south by a steep asymmetrical anticlinal ridge. Most structures show evidence of north-south compression that occurred during early Pleistocene time. Three well-defined unconformities represent widespread erosion in late Miocene, early to middle Pleistocene, and late Pleistocene time. The boundaries of Miocene, Pliocene, and lower Pleistocene strata continue uninterrupted eastward along the southern part of Santa Barbara basin to Hueneme Canyon, where they turn northeast and can be traced to the coast near Port Hueneme. These limits probably represent the south edge of the Santa Barbara basin during Pliocene and Pleistocene time. Fresh water-bearing materials of the Oxnard plain are unconsolidated Quaternary sediment laid down on more consolidated Tertiary rocks. Offshore, the total fresh water-bearing materials distinguished in the seismic reflection profiles attain a thickness of about 356 m and have an areal extent of over 760 km2. Strata that contain the offshore continuation of the five major on-land aquifers (Grimes Canyon, Fox Canyon, Hueneme, Mugu, and Oxnard aquifers) are identified in the seismic reflection profiles. These strata make up the two offshore ground-water basins, the Mound and Oxnard plain ground-water basins

  9. Sea-level rise and coastal groundwater inundation and shoaling at select sites in California, USA

    USGS Publications Warehouse

    Hoover, Daniel J.; Odigie, Kingsley; Swarzenski, Peter W.; Barnard, Patrick

    2016-01-01

    Study regionThe study region spans coastal California, USA, and focuses on three primary sites: Arcata, Stinson Beach, and Malibu Lagoon.Study focus1 m and 2 m sea-level rise (SLR) projections were used to assess vulnerability to SLR-driven groundwater emergence and shoaling at select low-lying, coastal sites in California. Separate and combined inundation scenarios for SLR and groundwater emergence were developed using digital elevation models of study site topography and groundwater surfaces constructed from well data or published groundwater level contours.New hydrological insights for the regionSLR impacts are a serious concern in coastal California which has a long (∼1800 km) and populous coastline. Information on the possible importance of SLR-driven groundwater inundation in California is limited. In this study, the potential for SLR-driven groundwater inundation at three sites (Arcata, Stinson Beach, and Malibu Lagoon) was investigated under 1 m and 2 m SLR scenarios. These sites provide insight into the vulnerability of Northern California coastal plains, coastal developments built on beach sand or sand spits, and developed areas around coastal lagoons associated with seasonal streams and berms. Northern California coastal plains with abundant shallow groundwater likely will see significant and widespread groundwater emergence, while impacts along the much drier central and southern California coast may be less severe due to the absence of shallow groundwater in many areas. Vulnerability analysis is hampered by the lack of data on shallow coastal aquifers, which commonly are not studied because they are not suitable for domestic or agricultural use. Shallow saline aquifers may be present in many areas along coastal California, which would dramatically increase vulnerability to SLR-driven groundwater emergence and shoaling. Improved understanding of the extent and response of California coastal aquifers to SLR will help in preparing for mitigation

  10. Bouse Formation in the Bristol basin near Amboy, California, USA

    USGS Publications Warehouse

    Miller, David M.; Reynolds, Robert E.; Bright, Jordan E.; Starratt, Scott W.

    2014-01-01

    Limestone beds underlain and overlain by alluvial fan conglomerate near Amboy, California, are very similar in many respects to parts of the Bouse Formation, suggesting that an arm of the Pliocene Bouse water body extended across a wide part of the southern Mojave Desert. The deposits are north of the town of Amboy at and below an elevation of 290 m, along the northern piedmont of the Bristol “dry” Lake basin. The Amboy outcrops contain the Lawlor Tuff (4.83 Ma), which is also found in an outcrop of the Bouse Formation in the Blythe basin near Buzzards Peak in the Chocolate Mountains, 180 km southeast of Amboy. Bouse exposures near Amboy are ∼3.4 m thick, white, distinctly bedded, with limestone and calcareous sandstone as well as stromatolite mounds; we interpret these as nearshore deposits. The Bouse at Amboy contains ostracodes, diatoms, and mollusks that indicate saline lake or estuarine environments with an admixture of fresh-water forms. Along with wading bird tracks and a spine from a marine fish, these fossils suggest that the deposits formed in saline waters near a fresh-water source such as a perennial stream. Beds of the outcrop dip southward and are 113 m above the surface of Bristol Playa, where similar age sediments are buried 270+ m deep, indicating significant faulting and vertical tectonics in this part of the Eastern California Shear Zone during the past 5 m.y. Confirmation of the Bouse Formation at Amboy strengthens previous assignments to the Bouse Formation for mudstones in driller logs at Danby “dry” Lake, California, and suggests that areally extensive arms of the Bouse water body were west of the Blythe basin. The Bristol basin arm of the lower Bouse basin probably was restricted from the main water body by narrow passages, but Bouse sediment there is similar to that in the Blythe basin, suggesting generally similar water chemistry and environmental conditions. Examining the degree to which Bouse deposits in the western arms

  11. Status and habitat use of the California black rail in the Southwestern USA

    USGS Publications Warehouse

    Conway, C.J.; Sulzman, C.

    2007-01-01

    California black rails (Laterallus jamaicensis coturniculus) occur in two disjunct regions: the southwestern USA (western Arizona and southern California) and northern California (Sacramento Valley and the San Francisco Bay area). We examined current status of black rails in the southwestern USA by repeating survey efforts first conducted in 1973-1974 and again in 1989, and also examined wetland plant species associated with black rail distribution and abundance. We detected 136 black rails in Arizona and southern California. Black rail numbers detected during past survey efforts were much higher than the numbers detected during our more intensive survey effort, and hence, populations have obviously declined. Plants that were more common at points with black rails included common threesquare (Schoenoplectus pungens), arrowweed (Pluchea sericea), Fremont cottonwood (Populus fremontii), seepwillow (Baccharis salicifolia), and mixed shrubs, with common threesquare showing the strongest association with black rail presence. Plant species and non-vegetative communities that were less common at points with black rails included California bulrush (Schoenoplectus californicus), southern cattail (Typha domingensis), upland vegetation, and open water. Black rails were often present at sites that had some saltcedar (Tamarix ramosissima), but were rarely detected in areas dominated by saltcedar. We recommend that a standardized black rail survey effort be repeated annually to obtain estimates of black rail population trends. Management of existing emergent marshes with black rails is needed to maintain stands of common threesquare in early successional stages. Moreover, wetland restoration efforts that produce diverse wetland vegetation including common threesquare should be implemented to ensure that black rail populations persist in the southwestern USA. ?? 2007, The Society of Wetland Scientists.

  12. Pesticides in amphibian habitats of Central and Northern California, USA

    USGS Publications Warehouse

    Fellers, Gary M.; Sparling, W; McConnell, Laura; Kleeman, Patrick M.; Drakeford, Leticia

    2013-01-01

    Previous studies have indicated that toxicity from pesticide exposure may be contributing to amphibian declines in California and that atmospheric deposition could be a primary pathway for pesticides to enter amphibian habitats. We report on a survey of California wetlands sampled along transects associated with Lassen Volcanic National Park, Lake Tahoe, Yosemite National Park, and Sequoia National Park. Each transect ran from the Pacific coast to the Cascades or Sierra Nevada mountains. Pacific chorus frogs (Pseudacris regilla), water, and sediment were collected from wetlands in 2001 and 2002. Twenty-three pesticides were found in frog, water, or sediment samples. Six contaminants including trifluralin, α-endosulfan, chlordanes, and trans-nonachlor were found in adult P. regilla. Seventeen contaminants were found in sediments, including endosulfan sulfate, chlordanes, 1-chloro-4-[2,2-dichloro-1-(4-chlorophenyl)ethenyl]benzene (4,4′-DDE), and chlorpyrifos. The mean number of chemicals detected per pond in sediments was 2.4 (2.5, standard deviation). In water, 17 chemicals were detected, with β-endosulfan being present in almost all samples. Trifluralin, chlordanes, and chlorpyrifos were the next most common. The mean number of chemicals in water per pond was 7.8 (2.9). With the possible exception of chlorpyrifos oxon in sediments and total endosulfans, none of the contaminants exceeded known lethal or sublethal concentrations in P. regilla tissue. Endosulfans, chlorpyrifos, and trifluralin were associated with historic and present day population status of amphibians. Cholinesterase, an essential neurological enzyme that can be depressed by certain pesticides, was reduced in tadpoles from areas with the greatest population declines.

  13. Santa Barbara Final Technical Report

    SciTech Connect

    Hacker, Angela; Hansen, Sherman; Watkins, Ashley

    2013-11-30

    This report serves as the Final Report for Santa Barbara County’s Energy Efficiency and Conservation Block Grant (EECBG) BetterBuildings Neighborhood Program (BBNP) award from the U.S. Department of Energy (DOE). This report explains how DOE BBNP funding was invested to develop robust program infrastructure designed to help property owners complete energy improvements, thereby generating substantial outcomes for the local environment and economy. It provides an overview of program development and design within the grant period, program accomplishments and challenges to date, and a plan for the future sustainability of emPower, the County’s innovative clean energy and building efficiency program. During the grant period, Santa Barbara County’s emPower program primarily targeted 32,000 owner occupied, single family, detached residential homes over 25 years old within the County. In order to help these homeowners and their contractors overcome market barriers to completing residential energy improvements, the program developed and promoted six voluntary, market-based service areas: 1) low cost residential financing (loan loss reserve with two local credit unions), 2) residential rebates, 3) local customer service, 4) expert energy advising, 5) workforce development and training, and 6) marketing, education and outreach. The main goals of the program were to lower building energy use, create jobs and develop a lasting regional building performance market. These services have generated important early outcomes and lessons after the program’s first two years in service. The DOE BBNP funding was extended through October 2014 to enable Santa Barbara County to generate continued outcomes. In fact, funding related to residential financing remains wholly available for the foreseeable future to continue offering Home Upgrade Loans to approximately 1,300 homeowners. The County’s investment of DOE BBNP funding was used to build a lasting, effective, and innovative

  14. Integrated Science Investigations of the Salton Sea, California, USA

    NASA Astrophysics Data System (ADS)

    Barnum, D.

    2006-12-01

    The Salton Sea is the latest waterbody to be formed by Colorado River floodwaters within the Salton Trough. Over the past 100 years, floodwaters have been replaced by agricultural drainage water and municipal discharges so that today, most of the water reaching the Salton Sea is agricultural drainwater flowing down the New, Alamo and Whitewater Rivers. An evaporation of about 6 feet per year and inputs of more than 4 million tons of salt per year have increased salinity of the waters of the Salton Sea. The current salinity level of approximately 46 parts per thousand is about 25% more saline than ocean water. Diverting water from the Imperial Valley agricultural lands to urban Southern California, and anticipated loss of inflows from Mexico and increasing water conservation activities will result in less water flowing into the Salton Sea. A Restoration Program is being conducted to evaluate the effects of diminished inflows on the Salton Sea Ecosystem and recommend alternatives to avoid or minimize those effects. The Salton Sea has become increasingly important as habitat for migratory birds because of wetland losses. California has lost approximately 91% of interior wetland acreage from pre-settlement until the mid-1980's. The Salton Sea provides critical habitat linking distant wetlands of Pacific and Central Flyways to wintering habitats in Mexico and Central and South America. More than 400 species of birds have been observed in the Salton Sea Ecosystem. Large percentages of the populations for several bird species such as the endangered Yuma Clapper Rail, the Eared Grebe, Snowy Plover and American White Pelican utilize the Salton Sea. Approximately 20 species of conservation concern utilize the Salton Sea ecosystem. Fish-eating birds such as Great Blue Herons, California Brown Pelicans, Double-crested Cormorants and several species of egrets are highly dependent upon the fishery of the Salton Sea. The Salton Sea fishery is now primarily comprised of tilapia

  15. Seventh progress report on the cooperative investigation of springs and streamflow in the Tecolote tunnel area of Santa Barbara County, California

    USGS Publications Warehouse

    Peterson, W.C.

    1957-01-01

    This report is the seventh in a a continuing series of progress reports giving the results of discharge measurements made at selected springs and streams in the Tecolote Tunnel are area of the Santa Ynez Mountains. The mountains. The measurement program was begun on its present scale in the latter part of 1948 by the Geological Survey at the request of the Santa Barbara County Water Agency and is being continued under a cooperative agreement whereby each agency pays half the cost of the investigation. The purpose of the program is to obtain sufficient factual data to determine what effect, if any, the inflow of ground water into Tecolote Tunnel will have on the flow of springs and streams in the vicinity of the tunnel. The area involved in the study, shown by plate 1, was made large enough to include a number of springs and steams believe to be outside the zone of influence of the tunnel. Tecolote Tunnel, completed late in 1955, was built by the Bureau of Reclamation for the purpose of conveying water stored in Cachuma Reservoir to the city of Santa Barbara and adjacent coastal communities. The alinement of the tunnel is roughly north and south through the center of the arbitrarily chosen study area which extends from the Painted Cave area on the east to Refugio Pass on the west and from the Santa Ynez River on the North to the Pacific Ocean on the south. The purpose of this report is to make available the factual data obtained from July 1954 to June 1956, together with a brief presentation of precipitation, springflow, and tunnel outflow for the entire period of investigation.

  16. Pesticides and amphibian population declines in California, USA

    USGS Publications Warehouse

    Sparling, Donald W.; Fellers, Gary M.; McConnell, Laura L.

    2001-01-01

    Several species of anuran amphibians have undergone drastic population declines in the western United States over the last 10 to 15 years. In California, the most severe declines are in the Sierra Mountains east of the Central Valley and downwind of the intensely agricultural San Joaquin Valley. In contrast, coastal and more northern populations across from the less agrarian Sacramento Valley are stable or declining less precipitously. In this article, we provide evidence that pesticides are instrumental in declines of these species. Using Hyla regilla as a sentinel species, we found that cholinesterase (ChE) activity in tadpoles was depressed in mountainous areas east of the Central Valley compared with sites along the coast or north of the Valley. Cholinesterase was also lower in areas where ranid population status was poor or moderate compared with areas with good ranid status. Up to 50% of the sampled population in areas with reduced ChE had detectable organophosphorus residues, with concentrations as high as 190 ppb wet weight. In addition, up to 86% of some populations had measurable endosulfan concentrations and 40% had detectable 4,4'- dichlorodiphenyldichloroethylene, 4,4'-DDT, and 2,4'-DDT residues.

  17. Spatial Distribution of Lead in Sacramento, California, USA

    PubMed Central

    Solt, Michael J.; Deocampo, Daniel M.; Norris, Michelle

    2015-01-01

    Chronic exposure to lead remains a health concern in many urban areas; Sacramento, California is one example, with state surveillance data showing nearly 3% of screened children reported with blood lead levels over 4.5 μg/dL in 2009. To investigate the environmental exposure, 91 soil samples were collected and analyzed by ICP-AES and ICP-MS for 14 elements. An additional 28 samples were collected from areas of focus and analyzed by hand-held X-ray fluorescence spectrometry for Pb and Zn. Analysis of the metals data revealed non-normal distributions and positive skewness, consistent with anthropogenic input. In addition, high correlation coefficients (≥0.75) of metal concentrations in Cd-Pb, Cd-Zn, Pb-Zn, and Sb-Sn pairs suggest similarities in the input mechanisms. Semivariograms generated from Pb and associated metals reveal these metals to exhibit spatial correlation. A prediction map of lead concentrations in soil was generated by ordinary kriging, showing elevated concentrations in soil located in the central, older area of Sacramento where historic traffic density and industrial activity have been historically concentrated. XRF analysis of Pb and Zn from additional samples verifies elevated concentrations in the central areas of Sacramento as predicted. PMID:25789455

  18. California sea lions (Zalophus californianus californianus) have lower chlorinated hydrocarbon contents in northern Baja California, México, than in California, USA.

    PubMed

    Del Toro, Ligeia; Heckel, Gisela; Camacho-Ibar, Víctor F; Schramm, Yolanda

    2006-07-01

    Chlorinated hydrocarbons (CHs) were determined in blubber samples of 18 California sea lions (Zalophus californianus californianus) that stranded dead along Todos Santos Bay, Ensenada, Baja California, México, January 2000-November 2001. Summation operatorDDTs were the dominant group (geometric mean 3.8 microg/g lipid weight), followed by polychlorinated biphenyls ( summation operatorPCBs, 2.96 microg/g), chlordanes (0.12 microg/g) and hexachlorocyclohexanes (0.06 microg/g). The summation operatorDDTs/ summation operatorPCBs ratio was 1.3. We found CH levels more than one order of magnitude lower than those reported for California sea lion samples collected along the California coast, USA, during the same period as our study. This sharp north-south gradient suggests that Z. californianus stranded in Ensenada (most of them males) would probably have foraged during the summer near rookeries 500-1000 km south of Ensenada and the rest of the year migrate northwards, foraging along the Baja California peninsula, including Ensenada, and probably farther north.

  19. Diatoms in Historical Tsunami Deposits, Northern California, USA

    NASA Astrophysics Data System (ADS)

    Hemphill-Haley, E.; Loofbourrow, C.

    2013-12-01

    A fundamental challenge in using microfossils to differentiate paleotsunami deposits from those of other sources (storms, floods) is to identify characteristics that favor one mode of deposition over the other. The silt- to sand-size siliceous hard parts (valves) of diatoms are commonly found as transported particles in tsunami deposits, but logically, may also be found in other types of coastal deposits of the same grain size. To date, observations on diatom preservation and provenance have been invoked as supporting evidence for paleotsunami deposits. These observations can be tested and refined by detailed observations of diatom assemblages in recent, well-documented tsunami deposits. As a component of the U.S. Geological Survey Science Application for Risk Reduction (SAFRR) project, diatoms were examined in two historical tsunami deposits on the central and northern California coast: the 1946 deposit on the north end of Half Moon Bay (37.5°N) and the 1964 deposit about 10 km south of Crescent City (41.7°N). Both tsunamis were the result of distant-source events across the Pacific Ocean from California: the M 8.1 Eastern Aleutians Islands earthquake (1946) and the M 9.2 Alaska earthquake (1964). At both localities tsunami inundation was documented by eyewitness accounts. The deposits are now preserved in the shallow subsurface as ~1-10 cm thick layers of silt and sand intercalated in peaty marsh or clay-rich lagoon deposits. These historical tsunami deposits are particularly useful for documenting characteristics of entrained diatom assemblages for comparison to paleotsunami deposits. First, the deposits consist of mostly fine sand and silt, and therefore are an appropriate particle size for containing diatoms. Second, although they are recent enough to have been documented by eyewitness accounts, they are also old enough to have been altered by natural geological processes (e.g., burial, compaction, taphonomic affects on diatom valves) as would be found in

  20. Chlorinated hydrocarbons in flatfishes from the Southern California, USA, Bight

    SciTech Connect

    Schiff, K.; Allen, M.J.

    2000-06-01

    Although inputs of chlorinated hydrocarbon compounds to the Southern California Bight (SCB) are presently low, historical deposits represent a source of bioaccumulation potential to sediment-associated fauna. To assess this bioaccumulation potential, 14 chlorinated hydrocarbon classes were measured in livers of three species of flatfish collected from 63 randomly selected sites on the coastal shelf between Point Conception and the United States-Mexico international border. Tissue contamination was widespread throughout the SCB, but was limited to just two chlorinated hydrocarbon classes. Virtually 100% of Pacific sanddab (Citharichthys sordidus) and longfin sanddab (Citharichthys xanthostigma) populations were estimated to be contaminated with dichlorodiphenyltrichloroethane (total DDT = sum of o.p{prime} and p,p{prime} isomers of DDT + dichlorodiphenyldichloroethylene [DDE] + dichlorodiphenyldichloroethane [DDD]) and/or polychlorinated biphenyls (total PCBs). Total DDT also contaminated the majority (64%) of the Dover sole (Microstomus pacificus) population in the SCB. Total PCB measurements in tissues of SCB flatfish were dominated by 12 congeners (52, 66, 87, 101, 105, 118, 128, 138, 153, 170, 180, and 187), which averaged 95% of the combined mass of the 27 congeners analyzed. Sediment concentrations accounted for most of the variability observed in tissue concentrations for 8 of these 12 congeners and total PCBs. Normalized sediment concentrations were also significantly correlated to normalized tissue concentrations for total DDT and p,p{prime}-DDE. Tissue concentrations measured in this study from reference areas of the SCB were compared to tissue concentrations measured form reference areas in studies conducted in 1977 and 1985. Total DDT and total PCB liver concentrations were found to have decreased one to two orders of magnitude in pacific and longfin sanddabs between 1985 and 1994. Total DDT and total PCB liver concentrations decreased 5- to 35-fold in

  1. Hydro-economic analysis of groundwater pumping for irrigated agriculture in California's Central Valley, USA

    NASA Astrophysics Data System (ADS)

    Medellín-Azuara, Josué; MacEwan, Duncan; Howitt, Richard E.; Koruakos, George; Dogrul, Emin C.; Brush, Charles F.; Kadir, Tariq N.; Harter, Thomas; Melton, Forrest; Lund, Jay R.

    2015-09-01

    As in many places, groundwater in California (USA) is the major alternative water source for agriculture during drought, so groundwater's availability will drive some inevitable changes in the state's water management. Currently, agricultural, environmental, and urban uses compete for groundwater, resulting in substantial overdraft in dry years with lowering of water tables, which in turn increases pumping costs and reduces groundwater pumping capacity. In this study, SWAP (an economic model of agricultural production and water use in California) and C2VISim (the California Department of Water Resources groundwater model for California's Central Valley) are connected. This paper examines the economic costs of pumping replacement groundwater during drought and the potential loss of pumping capacity as groundwater levels drop. A scenario of three additional drought years continuing from 2014 show lower water tables in California's Central Valley and loss of pumping capacity. Places without access to groundwater and with uncertain surface-water deliveries during drought are the most economically vulnerable in terms of crop revenues, employment and household income. This is particularly true for Tulare Lake Basin, which relies heavily on water imported from the Sacramento-San Joaquin Delta. Remote-sensing estimates of idle agricultural land between 2012 and 2014 confirm this finding. Results also point to the potential of a portfolio approach for agriculture, in which crop mixing and conservation practices have substantial roles.

  2. Earthquakes, Tsunamis, and Storms Recorded at Crescent City, California, USA

    NASA Astrophysics Data System (ADS)

    Kelsey, H. M.; Hemphill-Haley, E.; Loofbourrow, C.; Caldwell, D. J.; Graehl, N. A.; Robinson, M.

    2015-12-01

    Stratigraphic evidence for coseismic land-level change, tsunamis, and storms is found beneath freshwater marshes in coastal northern California at Crescent City (CC). Previous studies at CC have focused on tsunamis, including the 1964 farfield tsunami from the Alaska earthquake, and nearfield tsunamis from earthquakes in the Cascadia subduction zone (CSZ). In addition to new data on tsunami inundation and coseismic land-level change, evidence for deposition by large storms shows another significant coastal hazard for the area. Our results are from three freshwater wetland sites at CC: Marhoffer Creek, Elk Creek, and Sand Mine. Marhoffer Creek marsh is adjacent to the coast about 5 km north of CC, and at an elevation of > 3.4 m above NAVD88 (>1 m above highest tides). C-14 and diatom data show it has been a freshwater wetland for at least the past 1,800 yr. We identify tsunami deposits associated with two CSZ earthquakes (1700 C.E. and 1,650 yr BP) at Marhoffer Creek. Diatom data show that coseismic subsidence accompanied the 1700 C.E. earthquake; the tsunami deposit from that event extends 550 m inland from the beach. Cs-137 data show that thin sand layers about 70 m from the beach and 20 cm below the marsh surface were deposited by the farfield tsunami in 1964. Intercalated between the 1964 and 1700 tsunami deposits, and extending as far inland as the 1964 deposit, are storm deposits consisting of discontinuous layers of sand and detrital peat. The deposits are found in an interval about 0.5 m thick, and are perched at elevations above the highest winter tides. We surmise that at least some of these deposits record the catastrophic ARkStorm of 1861-1862. At Elk Creek wetland, diatom data confirm coseismic subsidence in 1700 in addition to tsunami deposition. The 1964 tsunami deposit is thin and found only proximal to the Elk Creek channel. At Sand Mine marsh, association with coseismic subsidence is used to differentiate CSZ tsunamis in a complex ~100 m wide

  3. Ground-water quality in the Santa Rita, Buellton, and Los Olivos hydrologic subareas of the Santa Ynez River basin, Santa Barbara County, California

    USGS Publications Warehouse

    Hamlin, S.N.

    1985-01-01

    Groundwater quality in the upper Santa Ynez River Valley in Santa Barbara County has degraded due to both natural and anthropogenic causes. The semiarid climate and uneven distribution of rainfall has limited freshwater recharge and caused salt buildup in water supplies. Tertiary rocks supply mineralized water. Agricultural activities (irrigation return flow containing fertilizers and pesticides, cultivation, feedlot waste disposal) are a primary cause of water quality degradation. Urban development, which also causes water quality degradation (introduced contaminants, wastewater disposal, septic system discharge, and land fill disposal of waste), has imposed stricter requirements on water supply quality. A well network was designed to monitor changes in groundwater quality related to anthropogenic activities. Information from this network may aid in efficient management of the groundwater basins as public water supplies, centered around three basic goals. First is to increase freshwater recharge to the basins by conjunctive surface/groundwater use and surface-spreading techniques. Second is to optimize groundwater discharge by efficient timing and spacing of pumping. Third is to control and reduce sources of groundwater contamination by regulating wastewater quality and distribution and, preferably, by exporting wastewaters from the basin. (USGS)

  4. Bartonella quintana in body lice and head lice from homeless persons, San Francisco, California, USA.

    PubMed

    Bonilla, Denise L; Kabeya, Hidenori; Henn, Jennifer; Kramer, Vicki L; Kosoy, Michael Y

    2009-06-01

    Bartonella quintana is a bacterium that causes trench fever in humans. Past reports have shown Bartonella spp. infections in homeless populations in San Francisco, California, USA. The California Department of Public Health in collaboration with San Francisco Project Homeless Connect initiated a program in 2007 to collect lice from the homeless to test for B. quintana and to educate the homeless and their caregivers on prevention and control of louse-borne disease. During 2007-2008, 33.3% of body lice-infested persons and 25% of head lice-infested persons had lice pools infected with B. quintana strain Fuller. Further work is needed to examine how homeless persons acquire lice and determine the risk for illness to persons infested with B. quintana-infected lice.

  5. Environmental Assessment: Western Range Instrumentation Modernization Program Vandenberg Air Force Base, Santa Barbara County, and Pillar Point Air Force Station, San Mateo County California

    DTIC Science & Technology

    2008-09-03

    California, but their age and associations in the San Francisco Bay region remain to be clarified. Radiocarbon - dated components at CA-SCL-178 near San...occupations. Numerous radiocarbon - dated components in San Francisco, San Mateo, Santa Clara, Santa Cruz, and Monterey counties represent the Middle...information if it does not display a currently valid OMB control number. 1. REPORT DATE 03 SEP 2008 2. REPORT TYPE 3. DATES COVERED 00-00-2008

  6. Wildfires alter rodent community structure across four vegetation types in southern California, USA

    USGS Publications Warehouse

    Brehme, Cheryl S.; Clark, Denise R.; Rochester, Carlton J.; Fisher, Robert N.

    2011-01-01

    We surveyed burned and unburned plots across four habitat reserves in San Diego County, California, USA, in 2005 and 2006, to assess the effects of the 2003 wildfires on the community structure and relative abundance of rodent species. The reserves each contained multiple vegetation types (coastal sage scrub, chaparral, woodland, and grassland) and spanned from 250 m to 1078 m in elevation. Multivariate analyses revealed a more simplified rodent community structure in all burned habitats in comparison to unburned habitats. Reduction in shrub and tree cover was highly predictive of changes in post-fire rodent community structure in the burned coastal sage scrub and chaparral habitats. Reduction in cover was not predictive for the less substantially burned woodlands and grasslands, for which we hypothesized that interspecific competition played a greater role in post-fire community structure. Across vegetation types, generalists and open habitat specialists typically increased in relative abundance, whereas closed habitat specialists decreased. We documented significant increases in relative abundance of the deer mouse (Peromyscus maniculatus Wagner) and Dulzura kangaroo rat (Dipodomys simulans Merriam). In contrast, we found significant decreases in relative abundance for the California mouse (Peromyscus californicus Gambel), San Diego pocket mouse (Chaetodipus fallax Merriam), desert woodrat (Neotoma lepida Thomas), and brush mouse (Peromyscus boylii Baird). Currently, our research program involves assessment of whether habitat conservation plans (HCPs) in southern California provide long-term protection to HCP covered species, as well as preserve ecosystem function. The scenario of increased wildfires needs to be incorporated into this assessment. We discuss our results in relation to management and conservation planning under a future scenario of larger and more frequent wildfires in southern California.

  7. Strain accumulation in the Santa Barbara Channel, 1971-1987

    NASA Technical Reports Server (NTRS)

    Larsen, Shawn; King, Nancy; Agnew, Duncan; Hager, Bradford

    1988-01-01

    Geophysical evidence suggests a significant amount of north-south convergence occurs across the Santa Barbara Channel. Tectonic studies indicate a discrepancy between observed fault slip in California and the North American-Pacific plate motion. Newer plate motion models (NUVEL-1) yield a lower rate of convergence. Global Positioning System (GPS) data collected in the Santa Barbara Channel in 1987, when combined with 1971 trilateration measurements, should be sufficient to resolve the present-day convergence rate. In early 1987. from January 3 to 7, GPS data were collected at 14 sites in California and at 5 additional stations throughout North America. The data can be used to estimate the rate of crustal deformation (convergence) ocurring across the Santa Barbara Channel. The GPS baselines were computed with the Bernese 2nd generation software. A comparison was made between baseline lengths obtained with the Burnese and MIT softwares. Baseline changes from 1971 to January, 1987 (GPS-Bernese) across the Santa Barbara Channel were computed. A uniform strain model was calculated from the baseline changes. The present-day rate of convergence across the Santa Barbara Channel was determined to be 8 to 10 mm/yr. This conclusion is obtained from changes in the baseline length measured with a 1971 trilateration survey and a January, 1987, GPS survey. The rapid convergence rate, in addition to the history of large seismic events, suggests this region is a prime target for future geodetic and geophysical studies.

  8. Temporal and spatial variation of atmospherically deposited organic contaminants at high elevation in Yosemite National Park, California, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Atmospherically deposited organic contaminants in the Sierra Nevada Mountains of California, USA, have exceeded some thresholds of concern, yet the distributions of contaminants in the mountains are not well known and there is little knowledge of temporal variation. The present study, (1) evaluated...

  9. Liquefaction caused by the 2009 Olancha, California (USA), M5.2 earthquake

    USGS Publications Warehouse

    Holzer, T.L.; Jayko, A.S.; Hauksson, E.; Fletcher, J.P.B.; Noce, T.E.; Bennett, M.J.; Dietel, C.M.; Hudnut, K.W.

    2010-01-01

    The October 3, 2009 (01:16:00 UTC), Olancha M5.2 earthquake caused extensive liquefaction as well as permanent horizontal ground deformation within a 1.2 km2area earthquake in Owens Valley in eastern California (USA). Such liquefaction is rarely observed during earthquakes of M ≤ 5.2. We conclude that subsurface conditions, not unusual ground motion, were the primary factors contributing to the liquefaction. The liquefaction occurred in very liquefiable sands at shallow depth (< 2 m) in an area where the water table was near the land surface. Our investigation is relevant to both geotechnical engineering and geology. The standard engineering method for assessing liquefaction potential, the Seed–Idriss simplified procedure, successfully predicted the liquefaction despite the small earthquake magnitude. The field observations of liquefaction effects highlight a need for caution by earthquake geologists when inferring prehistoric earthquake magnitudes from paleoliquefaction features because small magnitude events may cause such features.

  10. Tick-borne Relapsing Fever and Borrelia hermsii, Los Angeles County, California, USA

    PubMed Central

    Raffel, Sandra J.; Schrumpf, Merry E.; Webster, Larry S.; Marques, Adriana R.; Spano, Robyn; Rood, Michael; Burns, Joe; Hu, Renjie

    2009-01-01

    The primary cause of tick-borne relapsing fever in western North America is Borrelia hermsii, a rodent-associated spirochete transmitted by the fast-feeding soft tick Ornithodoros hermsi. We describe a patient who had an illness consistent with relapsing fever after exposure in the mountains near Los Angeles, California, USA. The patient’s convalescent-phase serum was seropositive for B. hermsii but negative for several other vector-borne bacterial pathogens. Investigations at the exposure site showed the presence of O. hermsi ticks infected with B. hermsii and the presence of rodents that were seropositive for the spirochete. We determined that this tick-borne disease is endemic to the San Gabriel Mountains near the greater Los Angeles metropolitan area. PMID:19624916

  11. Burn severity and non-native species in Yosemite National Park, California, USA

    USGS Publications Warehouse

    Kaczynski, Kristen M.; Beatty, Susan W.; van Wagtendonk, Jan W.; Marshall, Kristin N.

    2011-01-01

    We examined non-native species density three years after the Tuolumne Fire, which burned 1540 ha in upper montane forest in California, USA. We sampled 60 plots, stratified by burn severity (low, moderate, or high severity) and landscape position (lowland or upland). We detected non-native species in 8 of 11 (73 %) of high severity lowland sites and in 5 of 10 (50 %) of moderate severity lowland sites but, overall, richness and abundance was low. We detected only five non-native species, of which bull thistle (Cirsium vulgare [Savi] Ten.) was the most common. Although non-native abundance is currently low, we recommend continued low intensity monitoring, especially on high severity burned lowland sites.

  12. Hantavirus Infections among Overnight Visitors to Yosemite National Park, California, USA, 2012

    PubMed Central

    Núñez, Jonathan J.; Fritz, Curtis L.; Knust, Barbara; Buttke, Danielle; Enge, Barryett; Novak, Mark G.; Kramer, Vicki; Osadebe, Lynda; Messenger, Sharon; Albariño, César G.; Ströher, Ute; Niemela, Michael; Amman, Brian R.; Wong, David; Manning, Craig R.; Nichol, Stuart T.; Rollin, Pierre E.; Xia, Dongxiang; Watt, James P.

    2014-01-01

    In summer 2012, an outbreak of hantavirus infections occurred among overnight visitors to Yosemite National Park in California, USA. An investigation encompassing clinical, epidemiologic, laboratory, and environmental factors identified 10 cases among residents of 3 states. Eight case-patients experienced hantavirus pulmonary syndrome, of whom 5 required intensive care with ventilatory support and 3 died. Staying overnight in a signature tent cabin (9 case-patients) was significantly associated with becoming infected with hantavirus (p<0.001). Rodent nests and tunnels were observed in the foam insulation of the cabin walls. Rodent trapping in the implicated area resulted in high trap success rate (51%), and antibodies reactive to Sin Nombre virus were detected in 10 (14%) of 73 captured deer mice. All signature tent cabins were closed and subsequently dismantled. Continuous public awareness and rodent control and exclusion are key measures in minimizing the risk for hantavirus infection in areas inhabited by deer mice. PMID:24565589

  13. Earliest record of the invasive Foraminifera Trochammina hadai in San Francisco Bay, California, USA

    USGS Publications Warehouse

    McGann, Mary

    2014-01-01

    In 1995, Trochammina hadai, a benthic Foraminifera prevalent in Japanese estuaries, was found in San Francisco Bay, California, USA. Subsequent field investigations determined that the species was also present in nearly all of the major ports and estuaries along the western United States. Because of its widespread colonization, it is of interest to determine when T. hadai first appeared as an invasive in the coastal regions of the North Pacific. In San Francisco Bay, the species was not found in 404 surface samples collected between 1930 and 1981. In 1983, however, a grab sediment sample from one of four sites in the southern portion of the bay contained T. hadai. This site was the most northern of the four and contained 12 specimens of the invasive, comprising 1.5% of the assemblage. This is the earliest appearance on record of T. hadai in San Francisco Bay.

  14. Investigation of and Response to 2 Plague Cases, Yosemite National Park, California, USA, 2015

    PubMed Central

    Danforth, Mary; Novak, Mark; Petersen, Jeannine; Mead, Paul; Kingry, Luke; Weinburke, Matthew; Buttke, Danielle; Hacker, Gregory; Tucker, James; Niemela, Michael; Jackson, Bryan; Padgett, Kerry; Liebman, Kelly; Vugia, Duc

    2016-01-01

    In August 2015, plague was diagnosed for 2 persons who had visited Yosemite National Park in California, USA. One case was septicemic and the other bubonic. Subsequent environmental investigation identified probable locations of exposure for each patient and evidence of epizootic plague in other areas of the park. Transmission of Yersinia pestis was detected by testing rodent serum, fleas, and rodent carcasses. The environmental investigation and whole-genome multilocus sequence typing of Y. pestis isolates from the patients and environmental samples indicated that the patients had been exposed in different locations and that at least 2 distinct strains of Y. pestis were circulating among vector–host populations in the area. Public education efforts and insecticide applications in select areas to control rodent fleas probably reduced the risk for plague transmission to park visitors and staff. PMID:27870634

  15. Eremidrilus n. gen. (Annelida, Clitellata, Lumbriculidae) and new species from California, U.S.A.

    USGS Publications Warehouse

    Fend, S.V.; Rodriguez, P.

    2003-01-01

    A new Nearctic lumbriculid genus, Eremidrilus, includes four new California species (E. elegans, E. coyote, E. ritocsi, and E. felini) plus the new combination of Trichodrilus allegheniensis Cook, 1971 from the eastern U.S.A. Eremidrilus has the Trichodrilus arrangement of reproductive organs, but is distinguished by a filiform proboscis and male pores on folded porophores. A combination of other characters distinguishes most Eremidrilus species from most Trichodrilus species: (i) elongate-tubular thin-walled atria, (ii) posterior vasa deferentia forming a loop in XI, (iii) no posterior blood vessels, (iv) nephridia not present in VII. Spermathecae restricted to the first postatrial segment and laterally displaced spermathecal pores differentiate the western Eremidrilus species from the single eastern species. ?? 2003 NRC.

  16. Coccidioidomycosis among Workers Constructing Solar Power Farms, California, USA, 2011–2014

    PubMed Central

    Sondermeyer, Gail; Shusterman, Dennis; McNary, Jennifer; Vugia, Duc J.; McDowell, Ann; Borenstein, Penny; Gilliss, Debra; Ancock, Benedict; Prudhomme, Janice; Gold, Deborah; Windham, Gayle C.; Lee, Lauren; Materna, Barbara L.

    2015-01-01

    Coccidioidomycosis is associated with soil-disruptive work in Coccidioides-endemic areas of the southwestern United States. Among 3,572 workers constructing 2 solar power–generating facilities in San Luis Obispo County, California, USA, we identified 44 patients with symptom onset during October 2011–April 2014 (attack rate 1.2 cases/100 workers). Of these 44 patients, 20 resided in California outside San Luis Obispo County and 10 resided in another state; 9 were hospitalized (median 3 days), 34 missed work (median 22 days), and 2 had disseminated disease. Of the 25 patients who frequently performed soil-disruptive work, 6 reported frequent use of respiratory protection. As solar farm construction in Coccidioides-endemic areas increases, additional workers will probably be exposed and infected unless awareness is emphasized and effective exposure reduction measures implemented, including limiting dust generation and providing respiratory protection. Medical providers, including those in non–Coccidioides-endemic areas, should suspect coccidioidomycosis in workers with compatible illness and report cases to their local health department. PMID:26484688

  17. Community ecology and disease risk: lizards, squirrels, and the Lyme disease spirochete in California, USA.

    PubMed

    Salkeld, Daniel J; Lane, Robert S

    2010-01-01

    Vector-borne zoonotic diseases are often maintained in complex transmission cycles involving multiple vertebrate hosts and their arthropod vectors. In the state of California, U.S.A., the spirochete Borrelia burgdorferi, which causes Lyme disease, is transmitted between vertebrate hosts by the western black-legged tick, Ixodes pacificus. Several mammalian species serve as reservoir hosts of the spirochete, but levels of tick infestation, reservoir competence, and Borrelia-infection prevalence vary widely among such hosts. Here, we model the host (lizards, Peromyscus mice, Californian meadow voles, dusky-footed wood rats, and western gray squirrels), vector, and pathogen community of oak woodlands in northwestern California to determine the relative importance of different tick hosts. Observed infection prevalence of B. burgdorferi in host-seeking I. pacificus nymphs was 1.8-5.3%, and our host-community model estimated an infection prevalence of 1.6-2.2%. The western gray squirrel (Sciurus griseus) was the only source of infected nymphs. Lizards, which are refractory to Borrelia infection, are important in feeding subadult ticks but reduce disease risk (nymphal infection prevalence). Species identity is therefore critical in understanding and determining the local disease ecology.

  18. Quantifying the fire regime distributions for severity in Yosemite National Park, California, USA

    USGS Publications Warehouse

    Thode, Andrea E.; van Wagtendonk, Jan W.; Miller, Jay D.; Quinn, James F.

    2011-01-01

    This paper quantifies current fire severity distributions for 19 different fire-regime types in Yosemite National Park, California, USA. Landsat Thematic Mapper remote sensing data are used to map burn severity for 99 fires (cumulatively over 97 000 ha) that burned in Yosemite over a 20-year period. These maps are used to quantify the frequency distributions of fire severity by fire-regime type. A classification is created for the resultant distributions and they are discussed within the context of four vegetation zones: the foothill shrub and woodland zone; the lower montane forest zone; the upper montane forest zone and the subalpine forest zone. The severity distributions can form a building block from which to discuss current fire regimes across the Sierra Nevada in California. This work establishes a framework for comparing the effects of current fires on our landscapes with our notions of how fires historically burned, and how current fire severity distributions differ from our desired future conditions. As this process is refined, a new set of information will be available to researchers and land managers to help understand how fire regimes have changed from the past and how we might attempt to manage them in the future.

  19. Application of environmental groundwater tracers at the Sulphur Bank Mercury Mine, California, USA

    USGS Publications Warehouse

    Engle, M.A.; Goff, F.; Jewett, D.G.; Reller, G.J.; Bauman, J.B.

    2008-01-01

    Boron, chloride, sulfate, ??D, ??18O, and 3H concentrations in surface water and groundwater samples from the Sulphur Bank Mercury Mine (SBMM), California, USA were used to examine geochemical processes and provide constraints on evaporation and groundwater flow. SBMM is an abandoned sulfur and mercury mine with an underlying hydrothermal system, adjacent to Clear Lake, California. Results for non-3H tracers (i.e., boron, chloride, sulfate, ??D, and ??18O) identify contributions from six water types at SBMM. Processes including evaporation, mixing, hydrothermal water input and possible isotopic exchange with hydrothermal gases are also discerned. Tritium data indicate that hydrothermal waters and other deep groundwaters are likely pre-bomb (before ???1952) in age while most other waters were recharged after ???1990. A boron-based steady-state reservoir model of the Herman Impoundment pit lake indicates that 71-79% of its input is from meteoric water with the remainder from hydrothermal contributions. Results for groundwater samples from six shallow wells over a 6-month period for ??D and ??18O suggests that water from Herman Impoundment is diluted another 3% to more than 40% by infiltrating meteoric water, as it leaves the site. Results for this investigation show that environmental tracers are an effective tool to understand the SBMM hydrogeologic regime. ?? Springer-Verlag 2007.

  20. Coccidioidomycosis among Workers Constructing Solar Power Farms, California, USA, 2011-2014.

    PubMed

    Wilken, Jason A; Sondermeyer, Gail; Shusterman, Dennis; McNary, Jennifer; Vugia, Duc J; McDowell, Ann; Borenstein, Penny; Gilliss, Debra; Ancock, Benedict; Prudhomme, Janice; Gold, Deborah; Windham, Gayle C; Lee, Lauren; Materna, Barbara L

    2015-11-01

    Coccidioidomycosis is associated with soil-disruptive work in Coccidioides-endemic areas of the southwestern United States. Among 3,572 workers constructing 2 solar power-generating facilities in San Luis Obispo County, California, USA, we identified 44 patients with symptom onset during October 2011-April 2014 (attack rate 1.2 cases/100 workers). Of these 44 patients, 20 resided in California outside San Luis Obispo County and 10 resided in another state; 9 were hospitalized (median 3 days), 34 missed work (median 22 days), and 2 had disseminated disease. Of the 25 patients who frequently performed soil-disruptive work, 6 reported frequent use of respiratory protection. As solar farm construction in Coccidioides-endemic areas increases, additional workers will probably be exposed and infected unless awareness is emphasized and effective exposure reduction measures implemented, including limiting dust generation and providing respiratory protection. Medical providers, including those in non-Coccidioides-endemic areas, should suspect coccidioidomycosis in workers with compatible illness and report cases to their local health department.

  1. Factors influencing the variation in capture rates of shrews in southern California, USA

    USGS Publications Warehouse

    Laakkonen, Juha; Fisher, Robert N.; Case, Ted J.

    2003-01-01

    We examined the temporal variation in capture rates of shrewsNotiosorex crawfordi (Coues, 1877) and Sorex ornatus (Merriam, 1895) in 20 sites representing fragmented and continuous habitats in southern California, USA. InN. crawfordi, the temporal variation was significantly correlated with the mean capture rates. Of the 6 landscape variables analyzed (size of the landscape, size of the sample area, altitude, edge, longitude and latitude), sample area was positively correlated with variation in capture rates ofN. crawfordi. InS. ornatus, longitude was negatively correlated with variation in capture rates. Analysis of the effect of precipitation on the short- and long-term capture rates at 2 of the sites showed no correlation between rainfall and capture rates of shrews even though peak number of shrews at both sites were reached during the year of highest amount of rainfall. A key problem confounding capture rates of shrews in southern California is the low overall abundance of both shrew species in all habitats and seasons.

  2. Littoral transport rates in the Santa Barbara Littoral Cell: a process-based model analysis

    USGS Publications Warehouse

    Elias, E. P. L.; Barnard, Patrick L.; Brocatus, John

    2009-01-01

    Identification of the sediment transport patterns and pathways is essential for sustainable coastal zone management of the heavily modified coastline of Santa Barbara and Ventura County (California, USA). A process-based model application, based on Delft3D Online Morphology, is used to investigate the littoral transport potential along the Santa Barbara Littoral Cell (between Point Conception and Mugu Canyon). An advanced optimalization procedure is applied to enable annual sediment transport computations by reducing the ocean wave climate in 10 wave height - direction classes. Modeled littoral transport rates compare well with observed dredging volumes, and erosion or sedimentation hotspots coincide with the modeled divergence and convergence of the transport gradients. Sediment transport rates are strongly dependent on the alongshore variation in wave height due to wave sheltering, diffraction and focusing by the Northern Channel Islands, and the local orientation of the geologically-controlled coastline. Local transport gradients exceed the net eastward littoral transport, and are considered a primary driver for hot-spot erosion.

  3. Toxicity of two insecticides to California, USA, anurans and its relevance to declining amphibian populations

    USGS Publications Warehouse

    Sparling, D.W.; Fellers, G.M.

    2009-01-01

    Contaminants have been associated with population declines of several amphibian species in California (USA). Pesticides from the Central Valley of California are transported by winds into the Sierra Nevada Mountains and precipitate into wet meadows where amphibians breed. The present study examined the chronic toxicity of two of the insecticides most commonly used in the Central Valley and found in the mountains, chlorpyrifos and endosulfan, to larval Pacific treefrogs (Pseudacris regilla) and foothill yellow-legged frogs (Rana boylii) and discusses the implications of this toxicity to declining amphibian populations. Larvae were exposed to the pesticides from Gosner stages 25 to 26 through metamorphosis. The estimated median lethal concentration (LC50) for chlorpyrifos was 365 ??g/L in P. regilla and 66.5 ??g/L for R. boylii. Time to metamorphosis increased with concentration of chlorpyrifos in both species, and cholinesterase activity declined with exposure concentration in metamorphs of both species at Gosner stages 42 to 46. For endosulfan, the estimated LC50 was 15.6 ??g/L for P. regilla and 0.55 ??g/L for R. boylii. All R. boylii exposed to concentrations of greater than 0.8 ??g/L died before they entered metamorphosis. Pseudacris regilla remains relatively abundant and is broadly distributed throughout California. In contrast, R. boylii is among the species experiencing severe population declines. The present study adds to the increasing evidence that pesticides are very harmful to amphibians living in areas that are miles from sources of pesticide application. ?? 2009 SETAC.

  4. Landscape-level Connectivity in Coastal Southern California, USA, as Assessed through Carnivore Habitat Suitability

    USGS Publications Warehouse

    Hunter, R.D.; Fisher, R.N.; Crooks, K.R.

    2003-01-01

    Although the fragmentation of the natural landscape of coastal southern California, USA, is accelerating, large-scale assessments of regional connectivity are lacking. Because of their large area requirements and long dispersal movements, mammalian carnivores can be effective focal species to use when evaluating landscape-level connectivity. Our goal was to make an initial assessment of the extent of landscape-level connectivity in coastal southern California using mountain lions (Felis concolor [Linnaeusl) and bobcats (Felis rufus [Shreber]) as focal species. We first characterized habitat preferences for mountain lions and bobcats from previously derived habitat relationship models for these species; the resulting maps provided a coarse view of habitat preferences for use at regional scales. We then constructed GIS models to evaluate the disturbance impact of roadways and development, major determinants of carnivore distribution and abundance in the south coast region. Finally, we combined the habitat relationship models with the disturbance impact models to characterize habitat connectivity for mountain lions and bobcats in the ecoregion. Habitat connectivity in the ecoregion appeared higher for bobcats than for mountain lions due in part to higher habitat suitability for bobcats in coastal lowland areas. Our models suggest that much of the key carnivore habitat in the coastal southern California is at risk; over 80% of high suitability habitat and over 90% of medium suitability habitat for carnivores is found in the least protected land management classes. Overall, these models allow for (1) identification of core habitat blocks for carnivores and key landscape connections between core areas, (2) evaluation of the level of protection of these areas, and (3) a regional framework within which to develop and coordinate local management and conservation plans.

  5. Extensive geographic and ontogenetic variation characterizes the trophic ecology of a temperate reef fish on southern California (USA) rocky reefs

    PubMed Central

    Hamilton, Scott L.; Caselle, Jennifer E.; Lantz, Coulson A.; Egloff, Tiana L.; Kondo, Emi; Newsome, Seth D.; Loke-Smith, Kerri; Pondella, Daniel J.; Young, Kelly A.; Lowe, Christopher G.

    2015-01-01

    Interactions between predator and prey act to shape the structure of ecological communities, and these interactions can differ across space. California sheephead Semicossyphus pulcher are common predators of benthic invertebrates in kelp beds and rocky reefs in southern California, USA. Through gut content and stable isotope (δ13C and †15N) analyses, we investigated geographic and ontogenetic variation in trophic ecology across 9 populations located at island and mainland sites throughout southern California. We found extensive geographic variation in California sheephead diet composition over small spatial scales. Populations differed in the proportion of sessile filter/suspension feeders or mobile invertebrates in the diet. Spatial variation in diet was highly correlated with other life history and demographic traits (e.g. growth, survivorship, reproductive condition, and energy storage), in addition to proxies of prey availability from community surveys. Multivariate descriptions of the diet from gut contents roughly agreed with the spatial groupings of sites based on stable isotope analysis of both California sheephead and their prey. Ontogenetic changes in diet occurred consistently across populations, despite spatial differences in size structure. As California sheephead increase in size, diets shift from small filter feeders, like bivalves, to larger mobile invertebrates, such as sea urchins. Our results indicate that locations with large California sheephead present, such as many marine reserves, may experience increased predation pressure on sea urchins, which could ultimately affect kelp persistence. PMID:26246648

  6. Extensive geographic and ontogenetic variation characterizes the trophic ecology of a temperate reef fish on southern California (USA) rocky reefs.

    PubMed

    Hamilton, Scott L; Caselle, Jennifer E; Lantz, Coulson A; Egloff, Tiana L; Kondo, Emi; Newsome, Seth D; Loke-Smith, Kerri; Pondella, Daniel J; Young, Kelly A; Lowe, Christopher G

    Interactions between predator and prey act to shape the structure of ecological communities, and these interactions can differ across space. California sheephead Semicossyphus pulcher are common predators of benthic invertebrates in kelp beds and rocky reefs in southern California, USA. Through gut content and stable isotope (δ(13)C and †(15)N) analyses, we investigated geographic and ontogenetic variation in trophic ecology across 9 populations located at island and mainland sites throughout southern California. We found extensive geographic variation in California sheephead diet composition over small spatial scales. Populations differed in the proportion of sessile filter/suspension feeders or mobile invertebrates in the diet. Spatial variation in diet was highly correlated with other life history and demographic traits (e.g. growth, survivorship, reproductive condition, and energy storage), in addition to proxies of prey availability from community surveys. Multivariate descriptions of the diet from gut contents roughly agreed with the spatial groupings of sites based on stable isotope analysis of both California sheephead and their prey. Ontogenetic changes in diet occurred consistently across populations, despite spatial differences in size structure. As California sheephead increase in size, diets shift from small filter feeders, like bivalves, to larger mobile invertebrates, such as sea urchins. Our results indicate that locations with large California sheephead present, such as many marine reserves, may experience increased predation pressure on sea urchins, which could ultimately affect kelp persistence.

  7. Mercury correlations among six tissues for four waterbird species breeding in San Francisco Bay, California, USA

    USGS Publications Warehouse

    Eagles-Smith, C. A.; Ackerman, J.T.; Adelsbach, T.L.; Takekawa, J.Y.; Miles, A.K.; Keister, R.A.

    2008-01-01

    Despite a large body of research concerning mercury (Hg) in birds, no single tissue has been used consistently to assess Hg exposure, and this has hampered comparisons across studies. We evaluated the relationships of Hg concentrations among tissues in four species of waterbirds (American avocets [Recurvirostra americana], black-necked stilts [Himantopus mexicanus], Caspian terns [Hydroprogne caspia; formerly Sterna caspia], and Forster's terns [Sterna forsteri]) and across three life stages (prebreeding adults, breeding adults, and chicks) in San Francisco Bay, California, USA. Across species and life stages, Hg concentrations (least square mean ?? standard error) were highest in head feathers (6.45 ?? 0.31 ??g/g dry wt) and breast feathers (5.76 ?? 0.28 ??g/g dry wt), followed by kidney (4.54 ?? 0.22 ??g/g dry wt), liver (4.43 ?? 0.21 ??g/g dry wt), blood (3.10 ?? 0.15 ??g/g dry wt), and muscle (1.67 ?? 0.08 ??g/g dry wt). Relative Hg distribution among tissues, however, differed by species and life stage. Mercury concentrations were highly correlated among internal tissues (r 2 ??? 0.89). Conversely, the relationships between Hg in feathers and internal tissues were substantially weaker (r2 ??? 0.42). Regression slopes sometimes differed among species and life stages, indicating that care must be used when predicting Hg concentrations in one tissue based on those in another. However, we found good agreement between predictions made using a general tissue-prediction equation and more specific equations developed for each species and life stage. Finally, our results suggest that blood is an excellent, nonlethal predictor of Hg concentrations in internal tissues but that feathers are relatively poor indicators of Hg concentrations in internal tissues. ?? 2008 SETAC Printed in the USA.

  8. Accumulation of current-use and organochlorine pesticides in crab embryos from Northern California, USA

    USGS Publications Warehouse

    Smalling, Kelly L.; Morgan, Steven; Kuivila, Kathryn K.

    2010-01-01

    Invertebrates have long been used as resident sentinels for assessing ecosystem health and productivity. The shore crabs, Hemigrapsus oregonensis and Pachygrapsus crassipes, are abundant in estuaries and beaches throughout northern California, USA and have been used as indicators of habitat conditions in several salt marshes. The overall objectives of the present study were to conduct a lab-based study to test the accumulation of current-use pesticides, validate the analytical method and to analyze field-collected crabs for a suite of 74 current-use and legacy pesticides. A simple laboratory uptake study was designed to determine if embryos could bioconcentrate the herbicide molinate over a 7-d period. At the end of the experiment, embryos were removed from the crabs and analyzed by gas chromatography/mass spectrometry. Although relatively hydrophilic (log KOW of 2.9), molinate did accumulate with an estimated bioconcentration factor (log BCF) of approximately 2.5. Following method validation, embryos were collected from two different Northern California salt marshes and analyzed. In field-collected embryos 18 current-use and eight organochlorine pesticides were detected including synthetic pyrethroids and organophosphate insecticides, as well as DDT and its degradates. Lipid-normalized concentrations of the pesticides detected in the field-collected crab embryos ranged from 0.1 to 4 ppm. Pesticide concentrations and profiles in crab embryos were site specific and could be correlated to differences in land-use practices. These preliminary results indicate that embryos are an effective sink for organic contaminants in the environment and have the potential to be good indicators of ecosystem health, especially when contaminant body burden analyses are paired with reproductive impairment assays.

  9. Bat response to differing fire severity in mixed-conifer forest California, USA.

    PubMed

    Buchalski, Michael R; Fontaine, Joseph B; Heady, Paul A; Hayes, John P; Frick, Winifred F

    2013-01-01

    Wildlife response to natural disturbances such as fire is of conservation concern to managers, policy makers, and scientists, yet information is scant beyond a few well-studied groups (e.g., birds, small mammals). We examined the effects of wildfire severity on bats, a taxon of high conservation concern, at both the stand (<1 ha) and landscape scale in response to the 2002 McNally fire in the Sierra Nevada region of California, USA. One year after fire, we conducted surveys of echolocation activity at 14 survey locations, stratified in riparian and upland habitat, in mixed-conifer forest habitats spanning three levels of burn severity: unburned, moderate, and high. Bat activity in burned areas was either equivalent or higher than in unburned stands for all six phonic groups measured, with four groups having significantly greater activity in at least one burn severity level. Evidence of differentiation between fire severities was observed with some Myotis species having higher levels of activity in stands of high-severity burn. Larger-bodied bats, typically adapted to more open habitat, showed no response to fire. We found differential use of riparian and upland habitats among the phonic groups, yet no interaction of habitat type by fire severity was found. Extent of high-severity fire damage in the landscape had no effect on activity of bats in unburned sites suggesting no landscape effect of fire on foraging site selection and emphasizing stand-scale conditions driving bat activity. Results from this fire in mixed-conifer forests of California suggest that bats are resilient to landscape-scale fire and that some species are preferentially selecting burned areas for foraging, perhaps facilitated by reduced clutter and increased post-fire availability of prey and roosts.

  10. Urban sources and emissions of nitrous oxide and methane in southern California, USA

    NASA Astrophysics Data System (ADS)

    Townsend-Small, A.; Pataki, D.; Tyler, S. C.; Czimczik, C. I.; Xu, X.; Christensen, L. E.

    2012-12-01

    Anthropogenic activities have resulted in increasing levels of greenhouse gases, including carbon dioxide, methane, and nitrous oxide. While global and regional emissions sources of carbon dioxide are relatively well understood, methane and nitrous oxide are less constrained, particularly at regional scales. Here we present the results of an investigation of sources and emissions of methane and nitrous oxide in Los Angeles, California, USA, one of Earth's largest urban areas. The original goal of the project was to determine whether isotopes are useful tracers of agricultural versus urban nitrous oxide and methane sources. For methane, we found that stable isotopes (carbon-13 and deuterium) and radiocarbon are good tracers of biogenic versus fossil fuel sources. High altitude observations of methane concentration, measured continuously using tunable laser spectroscopy, and isotope ratios, measured on discrete flask samples using mass spectrometry, indicate that the predominant methane source in Los Angeles is from fossil fuels, likely from "fugitive" emissions from geologic formations, natural gas pipelines, oil refining, or power plants. We also measured nitrous oxide emissions and isotope ratios from urban (landscaping and wastewater treatment) and agricultural sources (corn and vegetable fields). There was no difference in nitrous oxide isotope ratios between the different types of sources, although stable isotopes did differ between nitrous oxide produced in oxic and anoxic wastewater treatment tanks. Our nitrous oxide flux data indicate that landscaped turfgrass emits nitrous oxide at rates equivalent to agricultural systems, indicating that ornamental soils should not be disregarded in regional nitrous oxide budgets. However, we also showed that wastewater treatment is a much greater source of nitrous oxide than soils regionally. This work shows that global nitrous oxide and methane budgets are not easily downscaled to regional, urban settings, which has

  11. Bat Response to Differing Fire Severity in Mixed-Conifer Forest California, USA

    PubMed Central

    Heady, Paul A.; Hayes, John P.; Frick, Winifred F.

    2013-01-01

    Wildlife response to natural disturbances such as fire is of conservation concern to managers, policy makers, and scientists, yet information is scant beyond a few well-studied groups (e.g., birds, small mammals). We examined the effects of wildfire severity on bats, a taxon of high conservation concern, at both the stand (<1 ha) and landscape scale in response to the 2002 McNally fire in the Sierra Nevada region of California, USA. One year after fire, we conducted surveys of echolocation activity at 14 survey locations, stratified in riparian and upland habitat, in mixed-conifer forest habitats spanning three levels of burn severity: unburned, moderate, and high. Bat activity in burned areas was either equivalent or higher than in unburned stands for all six phonic groups measured, with four groups having significantly greater activity in at least one burn severity level. Evidence of differentiation between fire severities was observed with some Myotis species having higher levels of activity in stands of high-severity burn. Larger-bodied bats, typically adapted to more open habitat, showed no response to fire. We found differential use of riparian and upland habitats among the phonic groups, yet no interaction of habitat type by fire severity was found. Extent of high-severity fire damage in the landscape had no effect on activity of bats in unburned sites suggesting no landscape effect of fire on foraging site selection and emphasizing stand-scale conditions driving bat activity. Results from this fire in mixed-conifer forests of California suggest that bats are resilient to landscape-scale fire and that some species are preferentially selecting burned areas for foraging, perhaps facilitated by reduced clutter and increased post-fire availability of prey and roosts. PMID:23483936

  12. 75 FR 67393 - Notice of Realty Action: Direct Sale of Public Lands in Santa Barbara County, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-02

    ... Bureau of Land Management Notice of Realty Action: Direct Sale of Public Lands in Santa Barbara County... land consisting of approximately 391 acres in Santa Barbara County, California. Each parcel would be... 23; Sec. 30, lot 2; Sec. 32, lot 3; Sec. 33, lot 10. The area described contains 31.68 acres in...

  13. Prevalence of selected pathogens in western pond turtles and sympatric introduced red-eared sliders in California, USA.

    PubMed

    Silbernagel, C; Clifford, D L; Bettaso, J; Worth, S; Foley, J

    2013-11-25

    Pathogen introduction by invasive species has been speculated to be a cause of declining western pond turtle Emys marmorata populations in California, USA. This study determined the prevalence of Ranavirus spp., Herpesvirus spp., Mycoplasma spp. (via polymerase chain reaction of blood and nasal flush contents), and Salmonella spp. infection (via fecal culture) in native E. marmorata and invasive red-eared sliders Trachemys scripta elegans and compared infection prevalence in E. marmorata populations sympatric with T. scripta elegans to E. marmorata populations that were not sympatric by sampling 145 E. marmorata and 33 T. scripta elegans at 10 study sites throughout California. Mycoplasma spp. were detected in both species: prevalence in E. marmorata was 7.8% in the northern, 9.8% in the central, and 23.3% in the southern California regions. In T. scripta elegans, Mycoplasma spp. were not detected in the northern California region but were detected at 4.5 and 14.3% in the central and southern regions, respectively. All turtles tested negative for Herpesvirus spp. and Ranavirus spp. Enteric bacteria but not Salmonella spp. were isolated from feces. E. marmorata populations that were sympatric with T. scripta elegans did not have increased risk of Mycoplasma spp. infection. For E. marmorata, there was a significant association between Mycoplasma spp. infection and lower body weight and being located in the southern California region. This study is the first of its kind to document pathogen prevalence in native E. marmorata habitats and those sympatric with T. scripta elegans in California.

  14. Tidal salt marsh sediment in California, USA. Part 2: occurrence and anthropogenic input of trace metals.

    PubMed

    Hwang, Hyun-Min; Green, Peter G; Higashi, Richard M; Young, Thomas M

    2006-09-01

    Surface sediment samples (0-5 cm) from 5 tidal salt marshes along the coast in California, USA were analyzed to investigate the occurrence and anthropogenic input of trace metals. Among study areas, Stege Marsh located in the central San Francisco Bay was the most contaminated marsh. Concentrations of metals in Stege Marsh sediments were higher than San Francisco Bay ambient levels. Zinc (55.3-744 microg g(-1)) was the most abundant trace metal and was followed by lead (26.6-273 microg g(-1)). Aluminum normalized enrichment factors revealed that lead was the most anthropogenically impacted metal in all marshes. Enrichment factors of lead in Stege Marsh ranged from 8 to 49 (median=16). Sediments from reference marshes also had high enrichment factors (2-8) for lead, indicating that lead contamination is ubiquitous, possibly due to continuous input from atmospherically transported lead that was previously used as a gasoline additive. Copper, silver, and zinc in Stege Marsh were also enriched by anthropogenic input. Though nickel concentrations in Stege Marsh and reference marshes exceeded sediment quality guidelines, enrichment factors indicated nickel from anthropogenic input was negligible. Presence of nickel-rich source rock such as serpentinite in the San Francisco Bay watershed can explain high levels of nickel in this area. Coefficients of variation were significantly different between anthropogenically impacted and non-impacted metals and might be used as a less conservative indicator for anthropogenic input of metals when enrichment factors are not available.

  15. Feline infectious peritonitis in a mountain lion (Puma concolor), California, USA.

    PubMed

    Stephenson, Nicole; Swift, Pamela; Moeller, Robert B; Worth, S Joy; Foley, Janet

    2013-04-01

    Feline infectious peritonitis (FIP) is a fatal immune-mediated vasculitis of felids caused by a mutant form of a common feline enteric virus, feline enteric coronavirus. The virus can attack many organ systems and causes a broad range of signs, commonly including weight loss and fever. Regardless of presentation, FIP is ultimately fatal and often presents a diagnostic challenge. In May 2010, a malnourished young adult male mountain lion (Puma concolor) from Kern County, California, USA was euthanized because of concern for public safety, and a postmortem examination was performed. Gross necropsy and histopathologic examination revealed necrotizing, multifocal myocarditis; necrotizing, neutrophilic, and histiocytic myositis and vasculitis of the tunica muscularis layer of the small and large intestines; and embolic, multifocal, interstitial pneumonia. Feline coronavirus antigen was detected in both the heart and intestinal tissue by immunohistochemistry. A PCR for coronavirus performed on kidney tissue was positive, confirming a diagnosis of FIP. Although coronavirus infection has been documented in mountain lions by serology, this is the first confirmed report of FIP.

  16. Temporal and spatial patterns of phytoplankton production in Tomales Bay, California, U.S.A.

    USGS Publications Warehouse

    Cole, B.E.

    1989-01-01

    Primary productivity in the water column was measured 14 times between April 1985 and April 1986 at three sites in Tomales Bay, California, USA The conditions at these three stations encompassed the range of hydrographic conditions, phytoplankton biomass, phytoplankton community composition, and turbidity typical of this coastal embayment. Linear regression of the measured daily carbon uptake against the composite parameter B Zp Io (where B is the average phytoplankton biomass in the photic zone; Zp is the photic depth; and Io is the daily surface insolation) indicates that 90% of the variability in primary productivity is explained by variations in phytoplankton biomass and light availability. The linear function derived using Tomales Bay data is essentially the same as that which explains more than 80% of the variation in productivity in four other estuarine systems. Using the linear function and measured values for B, Zp, and Io, the daily photic-zone productivity was estimated for 10 sites at monthly intervals over the annual period. The average daily photic-zone productivity for the 10 sites ranged from 0??2 to 2??2 g C m-2. The bay-wide average annual primary productivity in the water column was 400 g C m-2, with most of the uptake occuring in spring and early summer. Spatial and temporal variations in primary productivity were similar to variations in phytoplankton biomass. Productivity was highest in the seaward and central regions of the bay and lowest in the shallow landward region. ?? 1989.

  17. Pyrethroid and organophosphate pesticide-associated toxicity in two coastal watersheds (California, USA).

    PubMed

    Phillips, Bryn M; Anderson, Brian S; Hunt, John W; Siegler, Katie; Voorhees, Jennifer P; Tjeerdema, Ron S; McNeill, Katie

    2012-07-01

    Portions of the Santa Maria River and Oso Flaco Creek watersheds in central California, USA, are listed as impaired under section 303(d) of the Clean Water Act and require development of total maximum daily load (TMDL) allocations. These listings are for general pesticide contamination, but are largely based on historic monitoring of sediment and fish tissue samples that showed contamination by organochlorine pesticides. Recent studies have shown that toxicity in these watersheds is caused by organophosphate pesticides (water and sediment) and pyrethroid pesticides (sediment). The present study was designed to provide information on the temporal and spatial variability of toxicity associated with these pesticides to better inform the TMDL process. Ten stations were sampled in four study areas, one with urban influences, and the remaining in agriculture production areas. Water toxicity was assessed with the water flea Ceriodaphnia dubia, and sediment toxicity was assessed with the amphipod Hyalella azteca. Stations in the lower Santa Maria River had the highest incidence of toxicity, followed by stations influenced by urban inputs. Toxicity identification evaluations and chemical analysis demonstrated that the majority of the observed water toxicity was attributed to organophosphate pesticides, particularly chlorpyrifos, and that sediment toxicity was caused by mixtures of pyrethroid pesticides. The results demonstrate that both agriculture and urban land uses are contributing toxic concentrations of these pesticides to adjacent watersheds, and regional water quality regulators are now using this information to develop management objectives.

  18. Chemical preservation of insect cuticle from the Pleistocene asphalt deposits of California, USA

    NASA Astrophysics Data System (ADS)

    Stankiewicz, B. Artur; Briggs, Derek E. G.; Evershed, Richard P.; Duncan, Ian J.

    1997-06-01

    Cuticles of Coleoptera (beetles) and Orthoptera (crickets) from the Pleistocene asphalt deposits of Rancho La Brea and McKittrick in California, USA were studied by means of flash pyrolysis-gas chromatography /mass spectrometry (py-GC/MS). Commercial chitin, amino acid standards, and fresh and decayed cuticles of modern beetle and cricket were likewise investigated to allow the state of preservation of the fossil specimens to be interpreted. Insect cuticles are composed of chitin and proteins covalently cross-linked via catecholamine moieties. Pyrolysis of the fossil insects yielded all the products normally obtained from the pyrolysis of the chitin biopolymer, indicating that it has survived in a highly intact state. Proteins, on the other hand, are poorly preserved. Only phenols, indoles, and nitrobenzenes were present among the pyrolysis products, providing evidence for the preservation of tyrosine, tryptophan, and phenylalanine moieties. This demonstrates the preferential preservation of chitin in comparison with proteins, a result confirmed by scanning electron microscopy of the structure.

  19. Aerobic methane oxidation and methanotroph community composition during seasonal stratification in Mono Lake, California (USA).

    PubMed

    Carini, Stephen; Bano, Nasreen; LeCleir, Gary; Joye, Samantha B

    2005-08-01

    Patterns of aerobic methane (CH4) oxidation and associated methanotroph community composition were investigated during the development of seasonal stratification in Mono Lake, California (USA). CH4 oxidation rates were measured using a tritiated CH4 radiotracer technique. Fluorescence in situ hybridization (FISH), denaturing gradient gel electrophoresis (DGGE) and sequence analysis were used to characterize methanotroph community composition. A temporally shifting zone of elevated CH4 oxidation (59-123 nM day(-1)) was consistently associated with a suboxycline, microaerophilic zone that migrated upwards in the water column as stratification progressed. FISH analysis revealed stable numbers of type I (4.1-9.3 x 10(5) cells ml(-1)) and type II (1.4-3.4 x 10(5) cells ml(-1)) methanotrophs over depth and over time. Denaturing gradient gel electrophoresis and sequence analysis indicated slight shifts in methanotroph community composition despite stable absolute cell numbers. Variable CH4 oxidation rates in the presence of a relatively stable methanotroph population suggested that zones of high CH4 oxidation resulted from an increase in activity of a subset of the existing methanotroph population. These results challenge existing paradigms suggesting that zones of elevated CH4 oxidation activity result from the accumulation of methanotrophic biomass and illustrate that type II methanotrophs may be an important component of the methanotroph population in saline and/or alkaline pelagic environments.

  20. Hydrogen peroxide measurements in recreational marine bathing waters in Southern California, USA.

    PubMed

    Clark, Catherine D; De Bruyn, Warren J; Hirsch, Charlotte M; Jakubowski, Scott D

    2010-04-01

    Hydrogen peroxide (H(2)O(2)) was measured in the surf zone at 13 bathing beaches in Southern California, USA. Summer dry season concentrations averaged 122 +/- 38 nM with beaches with tide pools having lower levels (50-90 nM). No significant differences were observed for ebb waters at a salt marsh outlet vs. a beach (179 +/- 20 vs. 163 +/- 26 nM), and between ebb and flood tides at one site (171 +/- 24 vs. 146 +/- 42 nM). H(2)O(2) levels showed little annual variation. Diel cycling was followed over short (30 min; 24 h study) and long (d) time scales, with maximum afternoon concentration = 370 nM and estimated photochemical production rate of 44 nM h(-1). There was no correlation between the absorbance coefficient at 300 nm (used as a measure of chromophoric dissolved organic matter (CDOM) levels) and H(2)O(2). H(2)O(2) concentrations measured in this study are likely sufficient to inhibit fecal indicator bacteria in marine recreational waters through indirect photoinactivation.

  1. Fine scale mapping of the structure and composition of the Elkhorn Slough (California, USA) tidal plume

    NASA Astrophysics Data System (ADS)

    Fischer, Andrew M.; Ryan, John P.; Rienecker, Erich V.

    2017-01-01

    Fine scale mapping of the structure and composition of a tidal ebb plume from a highly modified coastal lagoon (Elkhorn Slough, California, USA) was conducted by combining in situ, observational data sets from surface underway mapping, autonomous underwater vehicle (AUV) profiles, drifter tracking and the analysis of plume structure indices. The results reveal a 6-m-deep, jet-like, sediment laden plume extending one km offshore at low tide, which becomes entrained in the prevailing nearshore circulation. The plume that exits the slough is significantly different from the water that enters the slough. The rapidly evolving discharge plume is associated with elevated and highly correlated (r = 0.93) concentrations of dissolved organic matter and nitrate. While dissolved constituents remain in the shallow plume and are transported northward with the prevailing current, sediment may settle quickly through the water column and can be transported southwestward with the littoral currents. This study illustrates the applications of AUVs, when coupled with additional datasets, for generating higher resolution observational snapshots of dynamic and ephemeral tidal plumes. The results provide unique perspective on small-scale dynamics of an estuarine plume and its influence on coastal ecology.

  2. Risk Factors for Human Lice and Bartonellosis among the Homeless, San Francisco, California, USA

    PubMed Central

    Cole-Porse, Charsey; Kjemtrup, Anne; Osikowicz, Lynn; Kosoy, Michael

    2014-01-01

    Homeless persons in San Francisco, California, USA, have been shown to have head and body lice infestations and Bartonella quintana infections. We surveyed a self-selected population of homeless persons in San Francisco to assess infestations of head and body lice, risks of having body lice, and presence of B. quintana in lice. A total of 203 persons who reported itching were surveyed during 2008–2010 and 2012: 60 (30%) had body lice, 10 (4.9%) had head lice, and 6 (3.0%) had both. B. quintana was detected in 10 (15.9%) of 63 body lice pools and in 6 (37.5%) of 16 head lice pools. Variables significantly associated (p<0.05) with having body lice in this homeless population included male sex, African–American ethnicity, and sleeping outdoors. Our study findings suggest that specific segments of the homeless population would benefit from information on preventing body lice infestations and louseborne diseases. PMID:25280380

  3. Eolian deposits in the Neoproterozoic Big Bear Group, San Bernardino Mountains, California, USA

    USGS Publications Warehouse

    Stewart, John H.

    2005-01-01

    Strata interpreted to be eolian are recognized in the Neoproterozoic Big Bear Group in the San Bernardino Mountains of southern California, USA. The strata consist of medium- to large-scale (30 cm to > 6 m) cross-stratified quartzite considered to be eolian dune deposits and interstratified thinly laminated quartzite that are problematically interpreted as either eolian translatent climbing ripple laminae, or as tidal-flat deposits. High index ripples and adhesion structures considered to be eolian are associated with the thinly laminated and cross-stratified strata. The eolian strata are in a succession that is characterized by flaser bedding, aqueous ripple marks, mudcracks, and interstratified small-scale cross-strata that are suggestive of a tidal environment containing local fluvial deposits. The eolian strata may have formed in a near-shore environment inland of a tidal flat. The Neoproterozoic Big Bear Group is unusual in the western United States and may represent a remnant of strata that were originally more widespread and part of the hypothetical Neoproterozoic supercontinent of Rodinia. The Big Bear Group perhaps is preserved only in blocks that were downdropped along Neoproterozoic extensional faults. The eolian deposits of the Big Bear Group may have been deposited during arid conditions that preceded worldwide glacial events in the late Neoproterozoic. Possibly similar pre-glacial arid events are recognized in northern Mexico, northeast Washington, Australia, and northwest Canada.

  4. Risk factors for human lice and bartonellosis among the homeless, San Francisco, California, USA.

    PubMed

    Bonilla, Denise L; Cole-Porse, Charsey; Kjemtrup, Anne; Osikowicz, Lynn; Kosoy, Michael

    2014-10-01

    Homeless persons in San Francisco, California, USA,have been shown to have head and body lice infestations and Bartonella quintana infections. We surveyed a self selected population of homeless persons in San Francisco to assess infestations of head and body lice, risks of having body lice, and presence of B. quintana in lice. A total of 203 persons who reported itching were surveyed during 2008-2010 and 2012: 60 (30%) had body lice, 10 (4.9%)had head lice, and 6 (3.0%) had both. B. quintana was detected in 10 (15.9%) of 63 body lice pools and in 6 (37.5%)of 16 head lice pools. Variables significantly associated(p<0.05) with having body lice in this homeless population included male sex, African-American ethnicity, and sleeping outdoors. Our study findings suggest that specific segments of the homeless population would benefit from information on preventing body lice infestations and louse borne diseases.

  5. Groundwater movement, recharge, and perchlorate occurrence in a faulted alluvial aquifer in California (USA)

    USGS Publications Warehouse

    Izbicki, John A.; Teague, Nicholas F.; Hatzinger, Paul B.; Böhlke, John Karl; Sturchio, Neil C.

    2015-01-01

    Perchlorate from military, industrial, and legacy agricultural sources is present within an alluvial aquifer in the Rialto-Colton groundwater subbasin, 80 km east of Los Angeles, California (USA). The area is extensively faulted, with water-level differences exceeding 60 m across parts of the Rialto-Colton Fault separating the Rialto-Colton and Chino groundwater subbasins. Coupled well-bore flow and depth-dependent water-quality data show decreases in well yield and changes in water chemistry and isotopic composition, reflecting changing aquifer properties and groundwater recharge sources with depth. Perchlorate movement through some wells under unpumped conditions from shallower to deeper layers underlying mapped plumes was as high as 13 kg/year. Water-level maps suggest potential groundwater movement across the Rialto-Colton Fault through an overlying perched aquifer. Upward flow through a well in the Chino subbasin near the Rialto-Colton Fault suggests potential groundwater movement across the fault through permeable layers within partly consolidated deposits at depth. Although potentially important locally, movement of groundwater from the Rialto-Colton subbasin has not resulted in widespread occurrence of perchlorate within the Chino subbasin. Nitrate and perchlorate concentrations at the water table, associated with legacy agricultural fertilizer use, may be underestimated by data from long-screened wells that mix water from different depths within the aquifer.

  6. Alicyclobacillus vulcanalis sp. nov., a thermophilic, acidophilic bacterium isolated from Coso Hot Springs, California, USA.

    PubMed

    Simbahan, Jessica; Drijber, Rhae; Blum, Paul

    2004-09-01

    A thermo-acidophilic Gram-positive bacterium, strain CsHg2T, which grows aerobically at 35-65 degrees C (optimum 55 degrees C) and at pH 2.0-6.0 (optimum 4.0), was isolated from a geothermal pool located in Coso Hot Springs in the Mojave Desert, California, USA. Phylogenetic analysis of 16S rRNA gene sequences showed that this bacterium was most closely related to the type strains of Alicyclobacillus acidocaldarius (97.8 % identity) and Alicyclobacillus sendaiensis (96.9 %), three Japanese strains denoted as UZ-1, KHA-31 and MIH 332 (96.1-96.5 %) and Alicyclobacillus genomic species FR-6 (96.3 %). Phenotypic characteristics including temperature and pH optima, G+C composition, acid production from a variety of carbon sources and sensitivity to different metal salts distinguished CsHg2T from A. acidocaldarius, A. sendaiensis and FR-6. The cell lipid membrane was composed mainly of omega-cyclohexyl fatty acid, consistent with membranes from other Alicyclobacillus species. Very low DNA-DNA hybridization values between CsHg2T and the type strains of Alicyclobacillus indicate that CsHg2T represents a distinct species. On the basis of these results, the name Alicyclobacillus vulcanalis sp. nov. is proposed for this organism. The type strain is CsHg2T (ATCC BAA-915T = DSM 16176T).

  7. [Experiences of undocumented Mexican migrant women when accessing sexual and reproductive health services in California, USA: a case study].

    PubMed

    Deeb-Sossa, Natalia; Díaz Olavarrieta, Claudia; Juárez-Ramírez, Clara; García, Sandra G; Villalobos, Aremis

    2013-05-01

    This study focuses on the experience of Mexican women migrants in California, USA, with the use of formal health services for sexual and reproductive health issues. The authors used a qualitative interpretative approach with life histories, interviewing eight female users of healthcare services in California and seven key informants in Mexico and California. There were three main types of barriers to healthcare: immigration status, language, and gender. Participants reported long waiting times, discriminatory attitudes, and high cost of services. A combination of formal and informal healthcare services was common. The assessment of quality of care was closely related to undocumented immigration status. Social support networks are crucial to help solve healthcare issues. Quality of care should take intercultural health issues into account.

  8. Reclaiming agricultural drainage water with nanofiltration membranes: Imperial Valley, California, USA

    USGS Publications Warehouse

    Kharaka, Y.K.; Schroeder, R.A.; Setmire, J.G.; ,

    2003-01-01

    We conducted pilot-scale field experiments using nanofiltration membranes to lower the salinity and remove Se, As and other toxic contaminants from saline agricultural wastewater in the Imperial Valley, California, USA. Farmlands in the desert climate (rainfall - 7.4 cm/a) of Imperial Valley cover -200,000 ha that are irrigated with water (-1.7 km3 annually) imported from the Colorado River. The salinity (-850 mg/L) and concentration of Se (-2.5 ??g/L) in the Colorado River water are high and evapotranpiration further concentrates salts in irrigation drainage water, reaching salinities of 3,000-15,000 mg/L TDS and a median Se value of -30 ??g/L. Experiments were conducted with two commercially available nanofiltration membranes, using drainage water of varying composition, and with or without the addition of organic precipitation inhibitors. Results show that these membranes selectively remove more than 95% of Se, SO4, Mo, U and DOC, and -30% of As from this wastewater. Low percentages of Cl, NO3 and HCO3, with enough cations to maintain electrical neutrality also were removed. The product water treated by these membranes comprised more than 90% of the wastewater tested. Results indicate that the treated product water from the Alamo River likely will have less than 0.2 ??g/L Se, salinity of 300-500 mg/L TDS and other chemical concentrations that meet the water quality criteria for irrigation and potable use. Because acceptability is a major issue for providing treated wastewater to urban centers, it may be prudent to use the reclaimed water for irrigation and creation of lower salinity wetlands near the Salton Sea; an equivalent volume of Colorado River water can then be diverted for the use of increasing populations of San Diego and other urban centers in southern California. Nanofiltration membranes yield greater reclaimed-water output and require lower pressure and less pretreatment, and therefore are generally more cost effective than traditional reverse

  9. Barbara Reed: Visionary Storyteller and Dramatist.

    ERIC Educational Resources Information Center

    Gangi, Jane

    2000-01-01

    Pays tribute to Barbara Reed, a leader in both children's drama and storytelling. Notes Barbara Reed's life accomplishments and many contributions to the field of theatre and performing arts education. (SC)

  10. RNA shotgun metagenomic sequencing of northern California (USA) mosquitoes uncovers viruses, bacteria, and fungi.

    PubMed

    Chandler, James Angus; Liu, Rachel M; Bennett, Shannon N

    2015-01-01

    Mosquitoes, most often recognized for the microbial agents of disease they may carry, harbor diverse microbial communities that include viruses, bacteria, and fungi, collectively called the microbiota. The composition of the microbiota can directly and indirectly affect disease transmission through microbial interactions that could be revealed by its characterization in natural populations of mosquitoes. Furthermore, the use of shotgun metagenomic sequencing (SMS) approaches could allow the discovery of unknown members of the microbiota. In this study, we use RNA SMS to characterize the microbiota of seven individual mosquitoes (species include Culex pipiens, Culiseta incidens, and Ochlerotatus sierrensis) collected from a variety of habitats in California, USA. Sequencing was performed on the Illumina HiSeq platform and the resulting sequences were quality-checked and assembled into contigs using the A5 pipeline. Sequences related to single stranded RNA viruses of the Bunyaviridae and Rhabdoviridae were uncovered, along with an unclassified genus of double-stranded RNA viruses. Phylogenetic analysis finds that in all three cases, the closest relatives of the identified viral sequences are other mosquito-associated viruses, suggesting widespread host-group specificity among disparate viral taxa. Interestingly, we identified a Narnavirus of fungi, also reported elsewhere in mosquitoes, that potentially demonstrates a nested host-parasite association between virus, fungi, and mosquito. Sequences related to 8 bacterial families and 13 fungal families were found across the seven samples. Bacillus and Escherichia/Shigella were identified in all samples and Wolbachia was identified in all Cx. pipiens samples, while no single fungal genus was found in more than two samples. This study exemplifies the utility of RNA SMS in the characterization of the natural microbiota of mosquitoes and, in particular, the value of identifying all microbes associated with a specific host.

  11. Multimedia screening of contaminants of emerging concern (CECS) in coastal urban watersheds in southern California (USA).

    PubMed

    Maruya, Keith A; Dodder, Nathan G; Sengupta, Ashmita; Smith, Deborah J; Lyons, J Michael; Heil, Ann T; Drewes, Jörg E

    2016-08-01

    To examine the occurrence and fate of contaminants of emerging concern (CECs) and inform future monitoring of CECs in coastal urban waterways, water, sediment, and fish tissue samples were collected and analyzed for a broad suite of pharmaceuticals and personal care products (PPCPs), commercial and/or household chemicals, current use pesticides, and hormones in an effluent-dominated river and multiple embayments in southern California (USA). In the Santa Clara River, which receives treated wastewater from several facilities, aqueous phase CECs were detectable at stations nearest discharges from municipal wastewater treatment plants but were attenuated downstream. Sucralose and the chlorinated phosphate flame retardants tris(1-chloro-2-propyl) phosphate (TCPP), tris(1,3-dichloro-2-propyl) phosphate (TDCPP), and tris(2-chloroethyl) phosphate (TCEP) were most abundant in water, with maximum concentrations of 35 μg/L, 3.3 μg/L, 1.4 μg/L, and 0.81 μg/L, respectively. Triclocarban, an antimicrobial agent in use for decades, was more prevalent in water than triclosan or nonylphenol. Maximum concentrations of bifenthrin, permethrin, polybrominated diphenyl ethers (PBDEs), and degradates of fipronil exceeded CEC-specific monitoring trigger levels recently established for freshwater and estuarine sediments by factors of 10 to 1000, respectively. Maximum fish tissue concentrations of PBDEs varied widely (370 ng/g and 7.0 ng/g for the Santa Clara River and coastal embayments, respectively), with most species exhibiting concentrations at the lower end of this range. These results suggest that continued monitoring of pyrethroids, PBDEs, and degradates of fipronil in sediment is warranted in these systems. In contrast, aqueous pharmaceutical concentrations in the Santa Clara River were not close to exceeding current monitoring trigger levels, suggesting a lower priority for targeted monitoring in this medium. Environ Toxicol Chem 2016;35:1986-1994. © 2016 SETAC.

  12. Tidal salt marsh sediment in California, USA. Part 1: occurrence and sources of organic contaminants.

    PubMed

    Hwang, Hyun-Min; Green, Peter G; Young, Thomas M

    2006-08-01

    Surface sediment samples (0-5 cm) from five tidal marshes along the coast of California, USA were analyzed for organic pollutants to investigate their relationship to land use, current distribution within marshes, and possible sources. Among the study areas, Stege Marsh, located in San Francisco Bay, was the most contaminated. Compared to San Francisco Bay, Stege Marsh had much higher levels of organic contaminants such as PCBs (polychlorinated biphenyls), DDTs, and chlordanes. At reference marshes (Tom's Point and Walker Creek in Tomales Bay), organic contaminants in sediments were very low. While PAHs (polycyclic aromatic hydrocarbons) were found at all of the study areas (22-13,600 ng g(-1)), measurable concentrations of PCBs were found only in the sediments from Stege Marsh (80-9,940 ng g(-1)). Combustion related (pyrogenic) high molecular weight PAHs were dominant in sediments from Stege and Carpinteria Marshes, while in sediments from Tom's Point and Walker Creek petroleum related (petrogenic) low molecular weight PAHs and alkyl-substituted PAHs were much more abundant than pyrogenic PAHs. PCB congener patterns in all of the Stege Marsh samples were the same and revealed that Aroclor 1248 was a predominant source. In all marshes, the sum of DDE and DDD accounted for more than 90% of total DDTs, indicating that DDT has degraded significantly. The ratios of p,p'-DDE to p,p'-DDD in sediments from Stege Marsh provide evidence of possible previous use of technical DDD. Chlordane ratios indicated that chlordanes have degraded slightly. Bis(2-ethylhexyl)phthalate (280-32,000 ng g(-1)) was the most abundant phthalate. The data indicates that Stege Marsh may be a source of contaminants that continue to be discharged into San Francisco Bay.

  13. Detection of the oyster herpesvirus in commercial bivalve in northern California, USA: conventional and quantitative PCR.

    PubMed

    Burge, Colleen A; Strenge, Robyn E; Friedman, Carolyn S

    2011-04-06

    The ostreid herpesvirus (OsHV-1) and related oyster herpesviruses (OsHV) are associated with world-wide mortalities of larval and juvenile bivalves. To quantify OsHV viral loads in mollusc tissues, we developed a SYBR Green quantitative PCR (qPCR) based on the A-region of the OsHV-1 genome. Reaction efficiency and precision were demonstrated using a plasmid standard curve. The analytical sensitivity is 1 copy per reaction. We collected Crassostrea gigas, C. sikamea, C. virginica, Ostrea edulis, O. lurida, Mytilus galloprovincialis, and Venerupis phillipinarum from Tomales Bay (TB), and C. gigas from Drakes Estero (DE), California, U.S.A., and initially used conventional PCR (cPCR) to test for presence of OsHV DNA. Subsequently, viral loads were quantified in selected samples of all tested bivalves except O. lurida. Copy numbers were low in each species tested but were significantly greater in C. gigas (p < 0.0001) compared to all other species, suggesting a higher level of infection. OsHV DNA was detected with cPCR and/or qPCR and confirmed by sequencing in C. gigas, C. sikamea, C. virginica, O. edulis, M. galloprovincialis, and V phillipinarum from TB and C. gigas from DE. These data indicate that multiple bivalve species may act as reservoirs for OsHV in TB. A lack of histological abnormalities in potential reservoirs requires alternative methods for their identification. Further investigation is needed to determine the host-parasite relationship for each potential reservoir, including characterization of viral loads and their relationship with infection (via in situ hybridization), assessments of mortality, and host responses.

  14. Calibration of numerical models for small debris flows in Yosemite Valley, California, USA

    USGS Publications Warehouse

    Bertolo, P.; Wieczorek, G.F.

    2005-01-01

    This study compares documented debris flow runout distances with numerical simulations in the Yosemite Valley of California, USA, where about 15% of historical events of slope instability can be classified as debris flows and debris slides (Wieczorek and Snyder, 2004). To model debris flows in the Yosemite Valley, we selected six streams with evidence of historical debris flows; three of the debris flow deposits have single channels, and the other three split their pattern in the fan area into two or more channels. From field observations all of the debris flows involved coarse material, with only very small clay content. We applied the one dimensional DAN (Dynamic ANalysis) model (Hungr, 1995) and the two-dimensional FLO2D model (O'Brien et al., 1993) to predict and compare the runout distance and the velocity of the debris flows observed in the study area. As a first step, we calibrated the parameters for the two softwares through the back analysis of three debris- flows channels using a trial-and-error procedure starting with values suggested in the literature. In the second step we applied the selected values to the other channels, in order to evaluate their predictive capabilities. After parameter calibration using three debris flows we obtained results similar to field observations We also obtained a good agreement between the two models for velocities. Both models are strongly influenced by topography: we used the 30 m cell size DTM available for the study area, that is probably not accurate enough for a highly detailed analysis, but it can be sufficient for a first screening. European Geosciences Union ?? 2005 Author(s). This work is licensed under a Creative Commons License.

  15. Bed composition generation for morphodynamic modeling: Case study of San Pablo Bay in California, USA

    USGS Publications Warehouse

    van der Wegen, M.; Dastgheib, A.; Jaffe, B.E.; Roelvink, D.

    2011-01-01

    Applications of process-based morphodynamic models are often constrained by limited availability of data on bed composition, which may have a considerable impact on the modeled morphodynamic development. One may even distinguish a period of "morphodynamic spin-up" in which the model generates the bed level according to some ill-defined initial bed composition rather than describing the realistic behavior of the system. The present paper proposes a methodology to generate bed composition of multiple sand and/or mud fractions that can act as the initial condition for the process-based numerical model Delft3D. The bed composition generation (BCG) run does not include bed level changes, but does permit the redistribution of multiple sediment fractions over the modeled domain. The model applies the concept of an active layer that may differ in sediment composition above an underlayer with fixed composition. In the case of a BCG run, the bed level is kept constant, whereas the bed composition can change. The approach is applied to San Pablo Bay in California, USA. Model results show that the BCG run reallocates sand and mud fractions over the model domain. Initially, a major sediment reallocation takes place, but development rates decrease in the longer term. Runs that take the outcome of a BCG run as a starting point lead to more gradual morphodynamic development. Sensitivity analysis shows the impact of variations in the morphological factor, the active layer thickness, and wind waves. An important but difficult to characterize criterion for a successful application of a BCG run is that it should not lead to a bed composition that fixes the bed so that it dominates the "natural" morphodynamic development of the system. Future research will focus on a decadal morphodynamic hindcast and comparison with measured bathymetries in San Pablo Bay so that the proposed methodology can be tested and optimized. ?? 2010 The Author(s).

  16. RNA shotgun metagenomic sequencing of northern California (USA) mosquitoes uncovers viruses, bacteria, and fungi

    PubMed Central

    Chandler, James Angus; Liu, Rachel M.; Bennett, Shannon N.

    2015-01-01

    Mosquitoes, most often recognized for the microbial agents of disease they may carry, harbor diverse microbial communities that include viruses, bacteria, and fungi, collectively called the microbiota. The composition of the microbiota can directly and indirectly affect disease transmission through microbial interactions that could be revealed by its characterization in natural populations of mosquitoes. Furthermore, the use of shotgun metagenomic sequencing (SMS) approaches could allow the discovery of unknown members of the microbiota. In this study, we use RNA SMS to characterize the microbiota of seven individual mosquitoes (species include Culex pipiens, Culiseta incidens, and Ochlerotatus sierrensis) collected from a variety of habitats in California, USA. Sequencing was performed on the Illumina HiSeq platform and the resulting sequences were quality-checked and assembled into contigs using the A5 pipeline. Sequences related to single stranded RNA viruses of the Bunyaviridae and Rhabdoviridae were uncovered, along with an unclassified genus of double-stranded RNA viruses. Phylogenetic analysis finds that in all three cases, the closest relatives of the identified viral sequences are other mosquito-associated viruses, suggesting widespread host-group specificity among disparate viral taxa. Interestingly, we identified a Narnavirus of fungi, also reported elsewhere in mosquitoes, that potentially demonstrates a nested host-parasite association between virus, fungi, and mosquito. Sequences related to 8 bacterial families and 13 fungal families were found across the seven samples. Bacillus and Escherichia/Shigella were identified in all samples and Wolbachia was identified in all Cx. pipiens samples, while no single fungal genus was found in more than two samples. This study exemplifies the utility of RNA SMS in the characterization of the natural microbiota of mosquitoes and, in particular, the value of identifying all microbes associated with a specific host

  17. Water availability and land subsidence in the Central Valley, California, USA

    USGS Publications Warehouse

    Faunt, Claudia; Sneed, Michelle; Traum, Jonathan A.; Brandt, Justin

    2016-01-01

    The Central Valley in California (USA) covers about 52,000 km2 and is one of the most productive agricultural regions in the world. This agriculture relies heavily on surface-water diversions and groundwater pumpage to meet irrigation water demand. Because the valley is semi-arid and surface-water availability varies substantially, agriculture relies heavily on local groundwater. In the southern two thirds of the valley, the San Joaquin Valley, historic and recent groundwater pumpage has caused significant and extensive drawdowns, aquifer-system compaction and subsidence. During recent drought periods (2007–2009 and 2012-present), groundwater pumping has increased owing to a combination of decreased surface-water availability and land-use changes. Declining groundwater levels, approaching or surpassing historical low levels, have caused accelerated and renewed compaction and subsidence that likely is mostly permanent. The subsidence has caused operational, maintenance, and construction-design problems for water-delivery and flood-control canals in the San Joaquin Valley. Planning for the effects of continued subsidence in the area is important for water agencies. As land use, managed aquifer recharge, and surface-water availability continue to vary, long-term groundwater-level and subsidence monitoring and modelling are critical to understanding the dynamics of historical and continued groundwater use resulting in additional water-level and groundwater storage declines, and associated subsidence. Modeling tools such as the Central Valley Hydrologic Model, can be used in the evaluation of management strategies to mitigate adverse impacts due to subsidence while also optimizing water availability. This knowledge will be critical for successful implementation of recent legislation aimed toward sustainable groundwater use.

  18. Water availability and land subsidence in the Central Valley, California, USA

    NASA Astrophysics Data System (ADS)

    Faunt, Claudia C.; Sneed, Michelle; Traum, Jon; Brandt, Justin T.

    2016-05-01

    The Central Valley in California (USA) covers about 52,000 km2 and is one of the most productive agricultural regions in the world. This agriculture relies heavily on surface-water diversions and groundwater pumpage to meet irrigation water demand. Because the valley is semi-arid and surface-water availability varies substantially, agriculture relies heavily on local groundwater. In the southern two thirds of the valley, the San Joaquin Valley, historic and recent groundwater pumpage has caused significant and extensive drawdowns, aquifer-system compaction and subsidence. During recent drought periods (2007-2009 and 2012-present), groundwater pumping has increased owing to a combination of decreased surface-water availability and land-use changes. Declining groundwater levels, approaching or surpassing historical low levels, have caused accelerated and renewed compaction and subsidence that likely is mostly permanent. The subsidence has caused operational, maintenance, and construction-design problems for water-delivery and flood-control canals in the San Joaquin Valley. Planning for the effects of continued subsidence in the area is important for water agencies. As land use, managed aquifer recharge, and surface-water availability continue to vary, long-term groundwater-level and subsidence monitoring and modelling are critical to understanding the dynamics of historical and continued groundwater use resulting in additional water-level and groundwater storage declines, and associated subsidence. Modeling tools such as the Central Valley Hydrologic Model, can be used in the evaluation of management strategies to mitigate adverse impacts due to subsidence while also optimizing water availability. This knowledge will be critical for successful implementation of recent legislation aimed toward sustainable groundwater use.

  19. Selenium bioaccumulation and body condition in shorebirds and terns breeding in San Francisco Bay, California, USA

    USGS Publications Warehouse

    Ackerman, Joshua T.; Eagles-Smith, Collin A.

    2009-01-01

    The present study evaluated Se bioaccumulation in four waterbird species (n = 206 birds) that breed within San Francisco Bay, California, USA: American avocets (Recurvirostra americana), black-necked stilts (Himantopus mexicanus), Forster's terns (Sterna forsteri), and Caspian terns (Hydroprogne caspia). Selenium concentrations were variable and influenced by several factors, including species, region, reproductive stage, age, and sex. Adult Se concentrations (μg/g dry wt) in livers ranged from 3.07 to 48.70 in avocets (geometric mean ± standard error, 7.92 ± 0.64), 2.28 to 41.10 in stilts (5.29 ± 0.38), 3.73 to 14.50 in Forster's terns (7.13 ± 0.38), and 4.77 to 14.40 in Caspian terns (6.73 ± 0.78). Avocets had higher Se concentrations in the North Bay compared to the South Bay, whereas stilt Se concentrations were similar between these regions and Forster's terns had lower Se concentrations in the North Bay compared to the South Bay. Female avocets had higher Se concentrations than male avocets, but this was not the case for stilts and Forster's terns. Of the factors assessed, reproductive stage had the most consistent effect among species. Prebreeding birds tended to have higher liver Se concentrations than breeding birds, but this trend was statistically significant only for Forster's terns. Forster's tern chicks had lower Se concentrations than Forster's tern adults, whereas avocet and stilt adults and chicks were similar. Additionally, body condition was negatively related to liver Se concentrations in Forster's tern adults but not in avocet, stilt, or Caspian tern adults and chicks. These variable results illustrate the complexity of Se bioaccumulation and highlight the need to sample multiple species and examine several factors to assess the impact of Se on wildlife.

  20. Toxicity of metal-contaminated sediments from Keswick Reservoir, California, USA

    SciTech Connect

    Finlayson, B.; Fujimura, R.; Huang, Z.Z.

    2000-02-01

    Keswick Reservoir, California, USA, receives metal-laden acid-mine drainage (AMD) from the abandoned Iron Mountain Mine. Mixing of the AMD with reservoir water causes precipitation and deposition of metal-rich sludge in the reservoir. Hydroelectric generation activities can scour the sediments and mobilize trace metals cadmium, copper, and zinc into the water column, thus creating potentially toxic conditions to fish and aquatic invertebrates. Sediment samples collected from Keswick Reservoir in 1993 and 1994 were analyzed for acid-volatile sulfides and for simultaneously extractable metals (SEM), and whole sediments and sediment elutriates were tested for toxicity to rainbow trout (Oncorhynchus mykiss), amphipods (Hyalella azteca), and cladocerans (Ceriodaphnia dubia). Acid-volatile sulfide concentrations in the sediments were low (<10 {micro}mol/g H{sub 2}S), indicating that dissolved metals in the sediment pore water were not limited by sulfide. The SEM concentrations were generally high (up to 11 {micro}g/g Cd, 4,800 {micro}g/g Cu, and 1,600 {micro}g/g Zn, dry weight) in the sediments. Whole sediments and 20% w/w sediment elutriates from 16 sites were tested for toxicity. Low survival (as low as 0{degree}) in whole sediments was generally associated with copper and zinc, and to a lesser extent cadmium, concentrations that exceeded probable effect level values for freshwater sediments; survival also may have been influenced by low pH and alkalinity conditions. Low survival (as low as 0%) in sediment elutriates was also generally associated with higher concentrations of dissolved zinc. Further study is required to formulate sediment cleanup levels that are protective of fish and wildlife. Source control in the Iron Mountain Mine drainage will eventually significantly lessen the production of sediments.

  1. Prevalences of zoonotic bacteria among seabirds in rehabilitation centers along the Pacific Coast of California and Washington, USA.

    PubMed

    Steele, Christine M; Brown, Richard N; Botzler, Richard G

    2005-10-01

    Many seabirds are rehabilitated annually by wildlife rehabilitation centers along the Pacific Coast, USA. Although various strains of zoonotic bacteria have been isolated from seabirds, risks to rehabilitators at these centers have not been well documented. From November 2001 through January 2003, we determined the prevalence of detectable enteric fauna by isolation and characterization of Gram-negative bacteria from cloacal swabs taken from 26 common murres (Uria aalge), 49 gulls (Larus spp.), and 14 other seabirds treated by rehabilitators in California and Washington (USA). At least 25 bacterial species were identified, including multiple strains of Escherichia coli, as well as Enterobacter cloacae, Citrobacter freundii, and Klebsiella pneumoniae. Antibiotic resistance was found in 13 of 19 bacterial isolates tested, including E. coli, K. pneumoniae, Acinetobacter baumanii, and Pseudomonas aeruginosa. Potential transfer of these bacteria poses a risk to wildlife rehabilitators and to seabirds in these centers, as well as to free-ranging birds.

  2. Comparison of enzootic risk measures for predicting West Nile disease, Los Angeles, California, USA, 2004-2010.

    PubMed

    Kwan, Jennifer L; Park, Bborie K; Carpenter, Tim E; Ngo, Van; Civen, Rachel; Reisen, William K

    2012-08-01

    In Los Angeles, California, USA, 2 epidemics of West Nile virus (WNV) disease have occurred since WNV was recognized in 2003. To assess which measure of risk was most predictive of human cases, we compared 3 measures: the California Mosquito-Borne Virus Surveillance and Response Plan Assessment, the vector index, and the Dynamic Continuous-Area Space-Time system. A case-crossover study was performed by using symptom onset dates from 384 persons with WNV infection to determine their relative environmental exposure to high-risk conditions as measured by each method. Receiver-operating characteristic plots determined thresholds for each model, and the area under the curve was used to compare methods. We found that the best risk assessment model for human WNV cases included surveillance data from avian, mosquito, and climate sources.

  3. Larva of Nothotrichia shasta Harris & Armitage (Trichoptera: Hydroptilidae) from California, USA, with its phylogenetic and taxonomic implications.

    PubMed

    Parys, Katherine A; Harris, Steven C

    2013-01-01

    Nothotrichia Flint 1967 is a small genus of infrequently collected microcaddisflies known from Chile and Brazil in South America, Costa Rica in Central America, and the United States in North America. Previously known only from adult specimens, we provide the first description and illustration of a larva in the genus, the larva of N. shasta from California, USA. We provide characters to separate Nothotrichia from other similar genera and an updated key to larval Hydroptilidae modified from that of Wiggins (1996). Larval characters provide additional evidence for the phylogeny and classification of the genus, which we now place tentatively in tribe Ochrotrichiini (subfamily Hydroptilinae).

  4. State Emergency Response and Field Observation Activities in California (USA) during the March 11, 2011, Tohoku Tsunami

    NASA Astrophysics Data System (ADS)

    Miller, K. M.; Wilson, R. I.; Goltz, J.; Fenton, J.; Long, K.; Dengler, L.; Rosinski, A.; California Tsunami Program

    2011-12-01

    This poster will present an overview of successes and challenges observed by the authors during this major tsunami response event. The Tohoku, Japan tsunami was the most costly to affect California since the 1964 Alaskan earthquake and ensuing tsunami. The Tohoku tsunami caused at least $50 million in damage to public facilities in harbors and marinas along the coast of California, and resulted in one fatality. It was generated by a magnitude 9.0 earthquake which occurred at 9:46PM PST on Thursday, March 10, 2011 in the sea off northern Japan. The tsunami was recorded at tide gages monitored by the West Coast/Alaska Tsunami Warning Center (WCATWC), which projected tsunami surges would reach California in approximately 10 hours. At 12:51AM on March 11, 2011, based on forecasted tsunami amplitudes, the WCATWC placed the California coast north of Point Conception (Santa Barbara County) in a Tsunami Warning, and the coast south of Point Conception to the Mexican border in a Tsunami Advisory. The California Emergency Management Agency (CalEMA) activated two Regional Emergency Operation Centers (REOCs) and the State Operation Center (SOC). The California Geological Survey (CGS) deployed a field team which collected data before, during and after the event through an information clearinghouse. Conference calls were conducted hourly between the WCATWC and State Warning Center, as well as with emergency managers in the 20 coastal counties. Coordination focused on local response measures, public information messaging, assistance needs, evacuations, emergency shelters, damage, and recovery issues. In the early morning hours, some communities in low lying areas recommended evacuation for their citizens, and the fishing fleet at Crescent City evacuated to sea. The greatest damage occurred in the harbors of Crescent City and Santa Cruz. As with any emergency, there were lessons learned and important successes in managing this event. Forecasts by the WCATWC were highly accurate

  5. Thin layers and species-specific characterization of the phytoplankton community in Monterey Bay, California, USA

    NASA Astrophysics Data System (ADS)

    Rines, J. E. B.; McFarland, M. N.; Donaghay, P. L.; Sullivan, J. M.

    2010-01-01

    During the summers of 2005 and 2006, experiments designed to understand the properties of densely concentrated, thin layers of plankton and the processes governing their dynamics were conducted in Monterey Bay, California, USA. Our goal was to elucidate the role that species-specific properties of phytoplankton play in thin layer dynamics. Using adaptive sampling, we collected water samples from inside and outside bio-optical features of the water column. Characterization of the phytoplankton was compiled from live and preserved samples, and analyzed within a framework of physical, optical, chemical and acoustical data. In both years, Monterey Bay was home to an extraordinarily diverse assemblage of phytoplankton and other protists. Bioluminescent dinoflagellates, and Harmful Algal Bloom (HAB) taxa were common. In 2005, community assemblages were widespread, thus advection of water through the experimental mooring array did not result in floristic changes. In 2006 phytoplankton were very patchy in horizontal distribution, and advection of water through the array was at times accompanied by dramatic shifts in community composition. Individual taxa often exhibited disparate patterns of vertical distribution, with some found throughout the water column, whereas others were restricted to narrow depth intervals. Thin layers were observed in both years. In 2005, the dinoflagellate Akashiwo sanguinea formed intense thin layers near the pycnocline at night, and migrated to near surface waters at dawn. In 2006, layer composition was more complex, and related to the water mass present at the time of sampling. Optically detected thin layers of phytoplankton can be studied from the perspective of the impact their high biomass has on both ecological processes, and ocean optics. But thin layers can also be studied from the species-specific perspective of each organism, its role within the thin layer habitat, and the impact that life within a thin layer has on its life history

  6. Mortality and herpesvirus infections of the Pacific oyster Crassostrea gigas in Tomales Bay, California, USA.

    PubMed

    Burge, Colleen A; Griffin, Frederick J; Friedman, Carolyn S

    2006-09-14

    Seed losses of Pacific oysters Crassostrea gigas have been associated with an ostreid herpesvirus-1 (OsHV-1) in Europe, and in 2002, a similar OsHV was detected in Tomales Bay, California, USA. In May of 2003, 5 stocks of seed Pacific oysters were planted at 2 sites (Inner Bay and Outer Bay) in Tomales Bay and monitored for mortality, presence/prevalence of OsHV (using polymerase chain reaction [PCR] and histology), and growth. Temperature (degrees C) and salinity data were collected every half an hour at each site. OsHV was detected at both the Inner and Outer Bay sites on the same sample date and mean temperature predicted OsHV presence (p < 0.005). High levels of mortality occurred 2 wk (Inner Bay site) and 4 wk (Outer Bay site) after OsHV detection. OsHV presence predicted mortality (p = 0.01). Temperature maximums and overall temperature exposure were greater at the Inner Bay site and may explain why mortality affected these oysters sooner than oysters planted at the Outer Bay site. Differences in cumulative mortality were significant among stocks (p < 0.0001), but not between sites (p > 0.05). OsHV prevalence was similar among stocks (p > 0.05) and between sites (p > 0.05). No evidence of herpesvirus-induced Cowdry type A nuclear inclusions or other pathogens were observed. Changes in tissue and cellular architecture including dilation of the digestive tubules and nuclear chromatin margination and pycnosis were observed in OsHV-infected oysters, consistent with previously observed OsHV infections. Stocks with smaller oysters had higher mortality rates than those with larger oysters; growth rate did not correlate with mortalities (p > 0.05). Taken together, these data suggest that the OsHV may cause or act in synergy with temperature to kill Pacific oyster seed in Tomales Bay, but further investigation of OsHV etiology in seed oysters is needed.

  7. Pliocene to late Pleistocene magmatism in the Aurora Volcanic Field, Nevada and California, USA

    NASA Astrophysics Data System (ADS)

    Kingdon, S.; Cousens, B.; John, D. A.; du Bray, E. A.

    2013-12-01

    The 3.9- 0.1 Ma Aurora Volcanic Field (AVF) covers 325 km2 east and southeast of the Bodie Hills, north of Mono Lake, California, USA. The AVF is located immediately northwest of the Long Valley magmatic system and adjacent and overlapping the Miocene Bodie Hills Volcanic Field (BHVF). Rock types range from trachybasalt to trachydacite, and high-silica rhyolite. The trachybasalts to trachydacites are weakly to moderately porphyritic (1-30%) with variable phenocryst assemblages that are some combination of plagioclase, hornblende, clinopyroxene, and lesser orthopyroxene, olivine, and/or biotite. Microphenocrysts are dominated by plagioclase, and include opaque oxides, clinopyroxene, and apatite. These rocks are weakly to strongly devitrified. The high-silica rhyolites are sparsely porphyritic with trace to 10% phenocrysts of quartz, sanidine, plagioclase, biotite, (+/- hornblende), accessory opaque oxide minerals, titanite, allanite, (+/-apatite, zircon), and have glassy groundmasses. Rocks in the AVF are less strongly porphyritic than those of BHVF. Plagioclase phenocrysts are often oscillatory zoned and many have sieve texture. Amphiboles have distinct black opaque rims. Xenocrystic quartz and plagioclase are rare. AVF lavas have bimodal SiO2 compositions, ranging from 49 to 78 wt%, with a gap between 65 and 75 wt%. They are high-K calc-alkaline to shoshonitic in composition, and are metaluminous to weakly peraluminous. They are enriched in rare earth elements (REE), especially light REEs, compared to the Miocene BHVF rocks. Primordial mantle-normalized incompatible element patterns show arc- or subduction-related signatures, with enrichment in Ba and Pb, and depletion in Nb and Ta. Enrichment in K and Sr and depletion in Ti are less pronounced than in the BHVF rocks. There is no correlation between lead isotope ratios and silica (initial 206Pb/204Pb ratios range from 18.974 to 19.151). Neodymium isotope ratios show a moderate negative correlation with silica

  8. Holocene climate on the Modoc Plateau, northern California, USA: The view from Medicine Lake

    USGS Publications Warehouse

    Starratt, S.W.

    2009-01-01

    Medicine Lake is a small (165 ha), relatively shallow (average 7.3 m), intermediate elevation (2,036 m) lake located within the summit caldera of Medicine Lake volcano, Siskiyou County, California, USA. Sediment cores and high-resolution bathymetric and seismic reflection data were collected from the lake during the fall of 1999 and 2000. Sediments were analyzed for diatoms, pollen, density, grain size (sand/mud ratio), total organic carbon (TOC), and micro-scale fabric analysis. Using both 14C (AMS) dating and tephrochronology, the basal sediments were estimated to have been deposited about 11,400 cal year BP, thus yielding an estimated average sedimentation rate of about 20.66 cm/1,000 year. The lowermost part of the core (11,400-10,300 cal year BP) contains the transition from glacial to interglacial conditions. From about 11,000-5,500 cal year BP, Medicine Lake consisted of two small, steep-sided lakes or one lake with two steep-sided basins connected by a shallow shelf. During this time, both the pollen (Abies/Artemisia ratio) and the diatom (Cyclotella/Navicula ratio) evidences indicate that the effective moisture increased, leading to a deeper lake. Over the past 5,500 years, the pollen record shows that effective moisture continued to increase, and the diatom record indicates fluctuations in the lake level. The change in the lake level pattern from one of the increasing depths prior to about 6,000 cal year BP to one of the variable depths may be related to changes in the morphology of the Medicine Lake caldera associated with the movement of magma and the eruption of the Medicine Lake Glass Flow about 5,120 cal year BP. These changes in basin morphology caused Medicine Lake to flood the shallow shelf which surrounds the deeper part of the lake. During this period, the Cyclotella/Navicula ratio and the percent abundance of Isoetes vary, suggesting that the level of the lake fluctuated, resulting in changes in the shelf area available for colonization by

  9. Fuel deposition rates of montane and subalpine conifers in the central Sierra Nevada, California, USA

    USGS Publications Warehouse

    van Wagtendonk, J.W.; Moore, P.E.

    2010-01-01

    Fire managers and researchers need information on fuel deposition rates to estimate future changes in fuel bed characteristics, determine when forests transition to another fire behavior fuel model, estimate future changes in fuel bed characteristics, and parameterize and validate ecosystem process models. This information is lacking for many ecosystems including the Sierra Nevada in California, USA. We investigated fuel deposition rates and stand characteristics of seven montane and four subalpine conifers in the Sierra Nevada. We collected foliage, miscellaneous bark and crown fragments, cones, and woody fuel classes from four replicate plots each in four stem diameter size classes for each species, for a total of 176 sampling sites. We used these data to develop predictive equations for each fuel class and diameter size class of each species based on stem and crown characteristics. There were consistent species and diameter class differences in the annual amount of foliage and fragments deposited. Foliage deposition rates ranged from just over 50 g m-2 year-1 in small diameter mountain hemlock stands to ???300 g m-2 year-1 for the three largest diameter classes of giant sequoia. The deposition rate for most woody fuel classes increased from the smallest diameter class stands to the largest diameter class stands. Woody fuel deposition rates varied among species as well. The rates for the smallest woody fuels ranged from 0.8 g m-2 year-1 for small diameter stands of Jeffrey pine to 126.9 g m-2 year-1 for very large diameter stands of mountain hemlock. Crown height and live crown ratio were the best predictors of fuel deposition rates for most fuel classes and species. Both characteristics reflect the amount of crown biomass including foliage and woody fuels. Relationships established in this study allow predictions of fuel loads to be made on a stand basis for each of these species under current and possible future conditions. These predictions can be used to

  10. ORGANIC POLLUTANT DEPOSITION TO THE SIERRA NEVADA (CALIFORNIA, USA) SNOWPACK AND ASSOCIATED LAKE AND STREAM ECOSYSTEM

    EPA Science Inventory

    High elevation ecosystems in the western USA and Canada are receiving deposition of persistent organic pollutants (POPs) that presumably originate in the USA as well as outside its borders. In April 1992 we obtained paired snowpack samples from each of two watersheds located in t...

  11. Flies from L.A., The Sequel: A further twelve new species of Megaselia (Diptera: Phoridae) from the BioSCAN Project in Los Angeles (California, USA)

    PubMed Central

    Brown, Brian V.; Disney, R. Henry L.

    2016-01-01

    Abstract Background Presented are continued results from the BioSCAN Project, an urban biodiversity study sampling primarily from private backyards in Los Angeles, California (USA). Presented are continued results from the BioSCAN Project, an urban biodiversity study sampling primarily from private backyards in Los Angeles, California (USA). New information Twelve new species of Megaselia (Diptera: Phoridae) are described: M. baileyae, M. friedrichae, M. gonzalezorum, M. joanneae, M. losangelensis, M. phyllissunae, M. pongsaiae, M. shatesae, M. stoakesi, M. studentorum, M. voluntariorum, M. wongae. PMID:27226746

  12. Exchange of polycyclic aromatic hydrocarbons among the atmosphere, water, and sediment in coastal embayments of southern California, USA.

    PubMed

    Sabin, Lisa D; Maruya, Keith A; Lao, Wenjian; Diehl, Dario; Tsukada, David; Stolzenbach, Keith D; Schiff, Kenneth C

    2010-02-01

    The present study investigated cross-media transport between both the sediment and the water column and between the water column and the atmosphere, to understand the role of each compartment as a source or a sink of polycyclic aromatic hydrocarbons (PAH) in southern California, USA, coastal waters. Concentrations of PAH were measured in the atmosphere, water column, and sediment at four water-quality-impaired sites in southern California: Ballona Creek Estuary, Los Angeles Harbor, Upper Newport Bay, and San Diego Bay. These concentrations were used to calculate site-specific sediment-water and atmosphere-water exchange fluxes. The net sediment-water exchange of total PAH (t-PAH) was positive, indicating that sediments were a source to the overlying water column. Furthermore, the net atmosphere-water exchange (gas exchange + dry particle deposition) of t-PAH was typically positive also, indicating the water column was a net source of PAH to the surrounding atmosphere through gas exchange. However, in all cases, the magnitude of the diffusive flux of PAH out of the sediments and into the water column far exceeded input or output of PAH through air/water exchange processes. These results demonstrate the potential importance of contaminated sediments as a source of PAH to the water column in coastal waters of southern California.

  13. RELATIONSHIPS BETWEEN ENVIRONMENTAL VARIABLES AND BENTHIC DIATOM ASSEMBLAGES IN CALIFORNIA CENTRAL VALLEY STREAMS (USA)

    EPA Science Inventory

    Streams and rivers in the California Central Valley Ecoregion have been substantially modified by human activities. This study examines distributional patterns of benthic diatom assemblages in relation to environmental characteristics in streams and rivers of this region. Benthic...

  14. Habitat requirements of the endangered California freshwater shrimp (Syncaris pacifica) in lagunitas and Olema creeks, Marin County, California, USA

    USGS Publications Warehouse

    Martin, Barbara A.; Saiki, Michael K.; Fong, Darren

    2009-01-01

    This study was conducted to better understand the habitat requirements and environmental limiting factors of Syncaris pacifica, the California freshwater shrimp. This federally listed endangered species is native to perennial lowland streams in a few watersheds in northern California. Field sampling occurred in Lagunitas and Olema creeks at seasonal intervals from February 2003 to November 2004. Ten glides, five pools, and five riffles served as fixed sampling reaches, with eight glides, four pools, and four riffles located in Lagunitas Creek and the remainder in Olema Creek. A total of 1773 S. pacifica was counted during this study, all of which were captured along vegetated banks in Lagunitas Creek. Syncaris pacifica was most numerous in glides (64), then in pools (31), and lastly in riffles (5). According to logistic regression analysis, S. pacifica was mostly associated with submerged portions of streambank vegetation (especially overhanging vegetation such as ferns and blackberries, emergent vegetation such as sedge and brooklime, and fine roots associated with water hemlock, willow, sedge, and blackberries) along with low water current velocity and a sandy substrate. These seemingly favorable habitat conditions for S. pacifica were present in glides and pools in Lagunitas Creek, but not in Olema Creek. ?? 2009 The Crustacean Society.

  15. Molecular Diversity of Trypanosoma cruzi Detected in the Vector Triatoma protracta from California, USA

    PubMed Central

    Shender, Lisa A.; Lewis, Michael D.; Rejmanek, Daniel; Mazet, Jonna A. K.

    2016-01-01

    Background Trypanosoma cruzi, causative agent of Chagas disease in humans and dogs, is a vector-borne zoonotic protozoan parasite that can cause fatal cardiac disease. While recognized as the most economically important parasitic infection in Latin America, the incidence of Chagas disease in the United States of America (US) may be underreported and even increasing. The extensive genetic diversity of T. cruzi in Latin America is well-documented and likely influences disease progression, severity and treatment efficacy; however, little is known regarding T. cruzi strains endemic to the US. It is therefore important to expand our knowledge on US T. cruzi strains, to improve upon the recognition of and response to locally acquired infections. Methodology/Principle Findings We conducted a study of T. cruzi molecular diversity in California, augmenting sparse genetic data from southern California and for the first time investigating genetic sequences from northern California. The vector Triatoma protracta was collected from southern (Escondido and Los Angeles) and northern (Vallecito) California regions. Samples were initially screened via sensitive nuclear repetitive DNA and kinetoplast minicircle DNA PCR assays, yielding an overall prevalence of approximately 28% and 55% for southern and northern California regions, respectively. Positive samples were further processed to identify discrete typing units (DTUs), revealing both TcI and TcIV lineages in southern California, but only TcI in northern California. Phylogenetic analyses (targeting COII-ND1, TR and RB19 genes) were performed on a subset of positive samples to compare Californian T. cruzi samples to strains from other US regions and Latin America. Results indicated that within the TcI DTU, California sequences were similar to those from the southeastern US, as well as to several isolates from Latin America responsible for causing Chagas disease in humans. Conclusions/Significance Triatoma protracta populations

  16. INDOOR AND OUTDOOR ULTRA-FINE PARTICLE COUNTS IN A 1999 TWO-SEASON FRESNO, CALIFORNIA, USA ACUTE CARDIAC PANEL STUDY

    EPA Science Inventory

    Indoor and Outdoor Ultrafine Particle Counts in a 1999 Two-Season Fresno, California, USA Acute Cardiac Panel Study.

    John Creason, Debra Walsh, Lucas Neas, US Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects R...

  17. An Interview with Barbara Keogh: Observations of Her Career and the Role of Context in Understanding Children with Disabilities

    ERIC Educational Resources Information Center

    Chamberlain, Steven P.

    2011-01-01

    Barbara Keogh is a true Californian. She was born in Glendale, received her education and professional training in California colleges and universities, and has been a professor at the University of California, Los Angeles (UCLA) for more than 40 years, where she is now Emerita. She is a licensed clinical psychologist and has worked as a…

  18. U.S. Geological Survey (USGS) Western Region; Santa Barbara Channel Coastal and Ocean Science

    USGS Publications Warehouse

    Johnson, Samuel Y.

    2009-01-01

    USGS coastal and ocean science in the Western United States and the Pacific integrates scientific expertise in geology, water resources, biology, and geography. Operating from 10 major science centers in the Western Region, the USGS is addressing a broad geographic and thematic range of important coastal and marine issues. In California, the Santa Barbara Channel represents one area of focus.

  19. The Educational Legacy of El Plan de Santa Barbara: An Interview with Reynaldo Macias

    ERIC Educational Resources Information Center

    Rangel, Javier

    2007-01-01

    In this interview, Reynaldo F. Macias, chair of the recently established Department of Chicana/o Studies at the University of California, Los Angeles (UCLA), talks about the historical significance of El Plan de Santa Barbara, its impact on Chicana/o studies throughout the Southwest, and its relevance in establishing a department at UCLA, and the…

  20. IMPACT II, Catalog of Santa Barbara County Teacher-Developed Curriculum Ideas: Disseminators, Adapters.

    ERIC Educational Resources Information Center

    Santa Barbara County Schools, CA.

    This document highlights the creative curriculum ideas of Santa Barbara County's (California) teachers that have been classroom-tested. IMPACT II is a teacher program that assists educational reform by providing innovative teacher-developed curriculum ideas, teacher-to-teacher networks, professional development, teacher recognition, and…

  1. Valve morphology and systematic position of Navicula walkeri (Bacillariophyceae), a diatom endemic to Oregon and California (USA)

    USGS Publications Warehouse

    Kociolek, J.P.; Spaulding, S.A.; Kingston, J.C.

    1998-01-01

    Variation in valve size and ultrastructure is documented for Navicula walkeri, a freshwater diatom species endemic to Oregon and central California (USA). In LM, this large diatom has longitudinal lines on either side of the axial area, as well as lineolate striae. External proximal raphe ends recurve toward the same side as the deflected distal ends. A large central nodule and bulbous areas at the terminus of each raphe branch are visible internally. The edges of an axial plate form the image of longitudinal lines. The suite of features present in N. walkeri suggests it is part of Navicula sensu stricto but occupies an isolated position within the group. Navicula sensu stricto is not an entirely homogeneous assemblage, and further refinements of the systematic affinities of its members may be warranted.

  2. The effects of timber harvesting on the structure and composition of adjacent old-growth coast redwood forest, California, USA

    USGS Publications Warehouse

    Russell, W.H.; Jones, C.

    2001-01-01

    Data collected across timber harvest boundaries on nine sites within the Redwood National and State Park management area in California, USA, were used to estimate the effective size of old-growth coast redwood preserves. Fourteen variables related to stand structure and composition, wildlife habitat, and physical environment were significantly correlated to distance from the timber harvest boundary using multiple regression analysis. A maximum depth of edge influence of 200 m was determined for variables exhibiting a significant correlation to the distance from the harvest edge. A spatial analysis using ArcView indicated that 53% of the old growth preserved within the study area was influenced by edge conditions, leaving 47% as effective old-growth.

  3. Health Care–Associated Infection Outbreak Investigations in Outpatient Settings, Los Angeles County, California, USA, 2000−2012

    PubMed Central

    Coelho, Laura; Bancroft, Elizabeth; Terashita, Dawn

    2015-01-01

    Health care services are increasingly delivered in outpatient settings. However, infection control oversight in outpatient settings to ensure patient safety has not improved and literature quantifying reported health care–associated infection outbreaks in outpatient settings is scarce. The objective of this analysis was to characterize investigations of suspected and confirmed outbreaks in outpatient settings in Los Angeles County, California, USA, reported during 2000–2012, by using internal logs; publications; records; and correspondence of outbreak investigations by characteristics of the setting, number, and type of infection control breaches found during investigations, outcomes of cases, and public health responses. Twenty-eight investigations met the inclusion criteria. Investigations occurred frequently, in diverse settings, and required substantial public health resources. Most outpatient settings investigated had >1 infection control breach. Lapses in infection control were suspected to be the outbreak source for 16 of the reviewed investigations. PMID:26196293

  4. Isolation of Onchocerca lupi in Dogs and Black Flies, California, USA

    PubMed Central

    Hassan, Hassan K.; Bolcen, Shanna; Kubofcik, Joseph; Nutman, Thomas B.; Eberhard, Mark L.; Middleton, Kelly; Wekesa, Joseph Wakoli; Ruedas, Gimena; Nelson, Kimberly J.; Dubielzig, Richard; De Lombaert, Melissa; Silverman, Bruce; Schorling, Jamie J.; Adler, Peter H.; Beeler, Emily S.

    2015-01-01

    In southern California, ocular infections caused by Onchocerca lupi were diagnosed in 3 dogs (1 in 2006, 2 in 2012). The infectious agent was confirmed through morphologic analysis of fixed parasites in tissues and by PCR and sequencing of amplicons derived from 2 mitochondrially encoded genes and 1 nuclear-encoded gene. A nested PCR based on the sequence of the cytochrome oxidase subunit 1 gene of the parasite was developed and used to screen Simulium black flies collected from southern California for O. lupi DNA. Six (2.8%; 95% CI 0.6%–5.0%) of 213 black flies contained O. lupi DNA. Partial mitochondrial16S rRNA gene sequences from the infected flies matched sequences derived from black fly larvae cytotaxonomically identified as Simulium tribulatum. These data implicate S. tribulatum flies as a putative vector for O. lupi in southern California. PMID:25897954

  5. Isolation of Onchocerca lupi in Dogs and Black Flies, California, USA.

    PubMed

    Hassan, Hassan K; Bolcen, Shanna; Kubofcik, Joseph; Nutman, Thomas B; Eberhard, Mark L; Middleton, Kelly; Wekesa, Joseph Wakoli; Ruedas, Gimena; Nelson, Kimberly J; Dubielzig, Richard; De Lombaert, Melissa; Silverman, Bruce; Schorling, Jamie J; Adler, Peter H; Unnasch, Thomas R; Beeler, Emily S

    2015-05-01

    In southern California, ocular infections caused by Onchocerca lupi were diagnosed in 3 dogs (1 in 2006, 2 in 2012). The infectious agent was confirmed through morphologic analysis of fixed parasites in tissues and by PCR and sequencing of amplicons derived from 2 mitochondrially encoded genes and 1 nuclear-encoded gene. A nested PCR based on the sequence of the cytochrome oxidase subunit 1 gene of the parasite was developed and used to screen Simulium black flies collected from southern California for O. lupi DNA. Six (2.8%; 95% CI 0.6%-5.0%) of 213 black flies contained O. lupi DNA. Partial mitochondrial16S rRNA gene sequences from the infected flies matched sequences derived from black fly larvae cytotaxonomically identified as Simulium tribulatum. These data implicate S. tribulatum flies as a putative vector for O. lupi in southern California.

  6. An Investigation of Summertime Inland Water Body Temperatures in California and Nevada (USA): Recent Trends and Future Projections

    NASA Astrophysics Data System (ADS)

    Healey, Nathan; Hook, Simon; Piccolroaz, Sebastiano; Toffolon, Marco; Radocinski, Robert

    2016-04-01

    Inland water body temperature has been identified as an ideal indicator of potential climate change. Understanding inland water body temperature trends is important for forecasting impacts to limnological, biological, and hydrological resources. Many inland water bodies are situated in remote locations with incomplete data records of in-situ monitoring or lack in-situ observations altogether. Thus, the utilization of satellite data is essential for understanding the behavior of global inland water body temperatures. Part of this research provides an analysis of summertime (July-September) temperature trends in the largest California/Nevada (USA) inland water bodies between 1991 and 2015. We examine satellite temperature retrievals from ATSR (ATSR-1, ATSR-2, AATSR), MODIS (Terra and Aqua), and VIIRS sensors. Our findings indicate that inland water body temperatures in the western United States were rapidly warming between 1991 and 2009, but since then trends have been decreasing. This research also includes implementation of a model called air2water to predict future inland water body surface temperature through the sole input of air temperature. Using projections from CMIP5-CCSM4 output, our model indicates that Lake Tahoe (USA) is expected to experience an increase of roughly 3 °C by 2100.

  7. Use of soil fumigants and air quality issues in California, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many high value cash crops use soil fumigants for profitable production.The primary fumigants used in California are 1,3-dichloropropene (Telone®), chloropicrin, metam salts (sodium or potassium), and methyl bromide. Most of these toxic chemicals and their formulations are volatile compounds (VOCs),...

  8. APPLICATION OF ENVIRONMENTAL GROUNDWATER TRACERS AT THE SULPHUR BANK MERCURY MINE, CALIFORNIA, USA

    EPA Science Inventory

    This paper reports on boron, chloride, sulfate, δD, δ18O, and 3H concentrations in surface water and groundwater samples from the Sulphur Bank Mercury Mine, California (SBMM) to examine and provide constraints on the site’s groundwater system. SBMM is an abandoned sulfur and merc...

  9. Earthshots: Satellite images of environmental change – Imperial Valley, California, USA

    USGS Publications Warehouse

    ,

    2013-01-01

    At the bottom of the sink lies the Salton Sea, the largest lake in California. It lacks an outlet to the ocean and lies 70 m below sea level. About 85% of the sea’s inflows come from agricultural runoff, and its waters are 37% saltier than the Pacific Ocean.

  10. Classic biological control of olive fruit fly in California, USA: release and recovery of introduced parasitoids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The establishment of olive fruit fly Bactrocera oleae (Rossi) in California led to a classical biological program. This study reports the release and recovery of two solitary larval endoparasitoids, Psyttalia humilis Silvestri and Psyttalia lounsburyi (Silvestri) from sub-Saharan Africa, in two coa...

  11. Olive fruit fly (Diptera: Tephritidae) in California table olives, USA: Invasion, distribution, and management implications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Olive fruit fly, Bactrocera oleae (Rossi), was discovered in California in late 1998. Thereafter, intensive research was conducted to develop pest control methods in table olives. The life history of olive fruit fly was elucidated, and the distribution and abundance of the adults determined through ...

  12. REVIEW OF THE FISHERIES OF THE SALTON SEA, CALIFORNIA, USA: PAST, PRESENT, FUTURE. (R826552)

    EPA Science Inventory

    The Salton Sea is an endorheic, 980-km2 salt lake in the Sonoran Desert of southern California. The historical fish community switched from freshwater to marine species as salinity increased due to evaporation and brackish water inflows. Three species, bairdiella (<...

  13. Cadmium content in fresh and canned squid (Loligo opalescens) from the Pacific coastal waters of California (USA).

    PubMed

    Galitsopoulou, A; Georgantelis, D; Kontominas, M G

    2009-01-01

    Cadmium (Cd) levels were determined in 70 samples of mantle tissue and 70 whole individual squid (Loligo opalescens; commercially known as California squid). Samples were collected from the coastal zones of California (USA) during the period 2007/2008. To further investigate consumer exposure to processed fishery products, cadmium concentration was also determined in 200 canned samples of squid. Cd concentrations in raw mantle were low, between 0.01 and 0.29 mg kg(-1) and below the tolerance limit of current regulations (1 mg kg(-1)). Respective concentrations in whole individuals were significantly higher, ranging from 0.51 to 1.18 mg kg(-1), attributed to the presence of the visceral portion in whole squid samples. Cd concentrations varied in relation to age and sex of squid, indicating that several physiological factors may influence accumulation. Furthermore, canning of squid substantially enhanced Cd levels. Cd concentration ranged 0.17-0.67 mg kg(-1) in canned mantle tissue and 0.86-2.07 mg kg(-1) in canned whole squid samples, due to both concentration after canning and movement of the metal between different tissues. Several biological compounds, including metallothioneins, nucleic acids and enzymes, may affect Cd concentrations in commercial fishery products.

  14. Complete nucleotide sequence and genome organization of an endornavirus from bottle gourd (Lagenaria siceraria) in California, U.S.A.

    PubMed

    Kwon, Sun-Jung; Tan, Shih-Hua; Vidalakis, Georgios

    2014-08-01

    The full-length nucleotide sequence and genome organization of an Endornavirus isolated from ornamental hard shell bottle gourd plants (Lagenaria siceraria (Molina) Standl.) in California (CA), USA tentatively named L. siceraria endornavirus-California (LsEV-CA) was determined. The LsEV-CA genome was 15088 bp in length, with a G + C content of 36.55 %. The lengths of the 5' and 3' untranslated regions were 111 and 52 bp, respectively. The genome of LsEV-CA contained one large ORF encoding a 576 kDa polyprotein. The predicted protein contains two glycosyltransferase motifs, as well as RNA-dependent RNA polymerase and helicase domains. LsEV-CA was detected in healthy-looking field-grown gourd plants, as well as plants expressing yellows symptoms. It was also detected in non-symptomatic greenhouse-grown gourd seedlings grown from seed obtained from the same field sites. These preliminary data indicate that LsEV-CA is likely not associated with the gourd-yellows syndrome observed in the field.

  15. Genotypes and phylogeographical relationships of infectious hematopoietic necrosis virus in California, USA

    USGS Publications Warehouse

    Kelley, G.O.; Bendorf, C.M.; Yun, S.C.; Kurath, G.; Hedrick, R.P.

    2007-01-01

    Infectious hematopoietic necrosis virus (IHNV) contains 3 major genogroups in North America with discreet geographic ranges designated as upper (U), middle (M), and lower (L). A comprehensive genotyping of 237 IHNV isolates from hatchery and wild salmonids in California revealed 25 different sequence types (a to y) all in the L genogroup; specifically, the genogroup contained 14 sequence types that were unique to individual isolates as well as 11 sequence types representing 2 or more identical isolates. The most evident trend was the phylogenetic and geographical division of the L genogroup into 2 distinct subgroups designated as LI and LII. Isolates within Subgroup LI were primarily found within waterways linked to southern Oregon and northern California coastal rivers. Isolates in Subgroup LII were concentrated within inland valley watersheds that included the Sacramento River, San Joaquin River, and their tributaries. The temporal and spatial patterns of virus occurrence suggested that infections among adult Chinook salmon in the hatchery or that spawn in the river are a major source of virus potentially infecting other migrating or resident salmonids in California. Serum neutralization results of the California isolates of IHNV corroborated a temporal trend of sequence divergence; specifically, 2 progressive shifts in which more recent virus isolates represent new serotypes. A comparison of the estimates of divergence rates for Subgroup LI (1 ?? ICT5 mutations per nucleotide site per year) indicated stasis similar to that observed in the U genogroup, while the Subgroup LII rate (1 ?? 10 3 mutations per nucleotide site per year) suggested a more active evolution similar to that of the M genogroup. ?? Inter-Research 2007.

  16. Age Determination of the Remaining Peat in the Sacramento-San Joaquin Delta, California, USA

    USGS Publications Warehouse

    Drexler, Judith Z.; de Fontaine, Christian S.; Knifong, Donna L.

    2007-01-01

    Introduction The Sacramento-San Joaquin Delta of California was once a 1,400 square kilometer (km2) tidal marsh, which contained a vast layer of peat ranging up to 15 meters (m) thick (Atwater and Belknap, 1980). Because of its favorable climate and highly fertile peat soils, the majority of the Delta was drained and reclaimed for agriculture during the late 1800s and early 1900s. Drainage of the peat soils changed the conditions in the surface layers of peat from anaerobic (having no free oxygen present) to aerobic (exposed to the atmosphere). This change in conditions greatly increased the decomposition rate of the peat, which consists largely of organic (plant) matter. Thus began the process of land-surface subsidence, which initially was a result of peat shrinkage and compaction, and later largely was a result of oxidation by which organic carbon in the peat essentially vaporized to carbon dioxide (Deverel and others, 1998; Ingebritsen and Ikehara, 1999). Because of subsidence, the land-surface elevation on farmed islands in the Delta has decreased from a few meters to as much as 8 m below local mean sea level (California Department of Water Resources, 1995; Steve Deverel, Hydrofocus, Inc., written commun., 2007). The USGS, in collaboration with the University of California at Davis, and Hydrofocus Inc. of Davis, California, has been studying the formation of the Delta and the impact of wetland reclamation on the peat column as part of a project called Rates and Evolution of Peat Accretion through Time (REPEAT). The purpose of this report is to provide results on the age of the remaining peat soils on four farmed islands in the Delta.

  17. Genotypes and phylogeographical relationships of infectious hematopoietic necrosis virus in California, USA.

    PubMed

    Kelley, Garry O; Bendorf, Christin M; Yun, Susan C; Kurath, Gael; Hedrick, Ronald P

    2007-08-13

    Infectious hematopoietic necrosis virus (IHNV) contains 3 major genogroups in North America with discreet geographic ranges designated as upper (U), middle (M), and lower (L). A comprehensive genotyping of 237 IHNV isolates from hatchery and wild salmonids in California revealed 25 different sequence types (a to y) all in the L genogroup; specifically, the genogroup contained 14 sequence types that were unique to individual isolates as well as 11 sequence types representing 2 or more identical isolates. The most evident trend was the phylogenetic and geographical division of the L genogroup into 2 distinct subgroups designated as LI and LII. Isolates within Subgroup LI were primarily found within waterways linked to southern Oregon and northern California coastal rivers. Isolates in Subgroup LII were concentrated within inland valley watersheds that included the Sacramento River, San Joaquin River, and their tributaries. The temporal and spatial patterns of virus occurrence suggested that infections among adult Chinook salmon in the hatchery or that spawn in the river are a major source of virus potentially infecting other migrating or resident salmonids in California. Serum neutralization results of the California isolates of IHNV corroborated a temporal trend of sequence divergence; specifically, 2 progressive shifts in which more recent virus isolates represent new serotypes. A comparison of the estimates of divergence rates for Subgroup LI (1 x 10(-5) mutations per nucleotide site per year) indicated stasis similar to that observed in the U genogroup, while the Subgroup LII rate (1 x 10(-3) mutations per nucleotide site per year) suggested a more active evolution similar to that of the M genogroup.

  18. Emplacement mode of a composite post-collisonal pluton in the Klamath Mountains (California, USA)

    NASA Astrophysics Data System (ADS)

    Machek, M.; Zavada, P.; Spicak, A.

    2011-12-01

    The Klamath Mountains represent an accreationary complex on the northwest California and southwestern Oregon. It consists of four arcuate belts representing terranes of former island archipelago environments that span in age from Paleozoic to Jurrasic and are divided by eastward dipping thrust faults (Snoke and Barnes, 2006). During and after the accretion, the entire thrust sheet was penetrated by numerous plutonic bodies. The Castle Crags pluton was selected for detailed internal fabrics to understand the emplacement mode of post-collisional plutons. Castle Crags pluton that intruded the Eastern Klamath terrane and in particular ultramafic Trinity Complex subterrane is an elliptical NW-SE elongated pluton with 12 km and 7 km in its long and short dimension, respectively. It is a well exposed composite plutonic body with about 1 km vertical crossfall. The pluton is affected by prominent NW-SE trending vertical joints and another less well developed vertical set perpendicular to the first one. The pluton is zoned and consists of three following igneous varieties: 1) marginal fine-grained granodioritic facies with abundant subsolidus shear zones, 2) coarse-grained granodiorite and 3) central, circular in plan-form and about 2 km in diameter, domain of trondhjemite. Numerous miarolitic cavities with macroscopically measurable trends mark the transition between the central trondhjemite and surrounding granodiorite (Vennum, 1980 a,b). Macroscopic foliations, jointing and sampling on the Castle Crags was carried out along the main crest of the pluton and numerous sideway crests and valleys gaining about 70 samples. The internal magmatic foliations and magnetic foliations show a concentric pattern of margin-parallel vertical foliations. The magnetic lineations reveal plunge trends parallel to the margins of the pluton and continuously increasing plunge angles from the margin to the core of the pluton. The zonality and fabric pattern of the pluton can reflect either

  19. A Radiocarbon Chronology of Hunter-Gatherer Occupation from Bodega Bay, California, USA

    SciTech Connect

    Kennedy, M A; Russell, A D; Guilderson, T P

    2005-04-27

    The evolution of hunter-gatherer maritime adaptations in western North America has been a prominent topic of discussion among archaeologists in recent years (e.g. Arnold 1992; Erlandson and Colten 1991; Erlandson and Glassow 1997; Lightfoot 1993). Although vast coastal regions of the northeastern Pacific (for example, southern California) have been investigated in detail, our understanding of hunter-gatherer developments along the coast of northern California is limited. Previous research indicates that humans have exploited marine mammals, fish and shellfish along the northern California shoreline since the early Holocene (Schwaderer 1992). By the end of the late Holocene, some groups remained year-round on the coast subsisting primarily on marine resources (e.g. Gould 1975; Hildebrandt and Levulett 2002). However, a paucity of well-dated cultural deposits has hindered our understanding of these developments, particularly during the early and middle Holocene. The lack of a long and reliable chronological sequence has restricted our interpretations of behavioral change, including the adaptive strategies (such as foraging, mobility and settlement) used by human foragers to colonize and inhabit the coastal areas of this region. These shortcomings have also hindered comparative interpretations with other coastal and inland regions in western North America. Here we present a Holocene radiocarbon chronology of hunter-gatherer occupation based on contemporaneous samples of charcoal and Mytilus californianus (California sea mussel) shell recovered from seven archaeological sites near Bodega Bay, California. A series of 127 {sup 14}C ages reveal a chronological sequence that spans from ca. 8940-110 cal BP (1{sigma}) (7890-160 {sup 14}C yr BP = charcoal; 8934-101 {sup 14}C yr BP = shell). As part of this sequence, we report new {sup 14}C dates from the stratified cave and open-air midden deposits at Duncan's Landing (CA-SON-348/H). In addition, we present {sup 14}C ages

  20. Stable sulfur isotope hydrogeochemical studies using desert shrubs and tree rings, Death Valley, California, USA

    SciTech Connect

    Yang, Wenbo; Spencer, R.J.; Krouse, H.R.

    1996-08-01

    The {delta}{sup 34}S values of two dominant xerophytes, Atriplex hymenehytra and Larrea tridentata, in Death Valley, California, vary similarly from +7 to +18{per_thousand}, corresponding isotopically to sulfate in the water supplies at a given location. Going radially outwards, tree ring data from a phreatophyte tree, Tamarix aphylla, show a distinct time dependence, with {delta}{sup 34}S values increasing from +13.5 to +18{per_thousand} for soluble sulfate and from +12 to +17% for total sulfur. These data are interpreted in terms of sulfur sources, water sources and flow paths, and tree root growth. 32 refs., 3 figs., 3 tabs.

  1. Parasites of the African clawed frog, Xenopus laevis, in southern California, U.S.A

    USGS Publications Warehouse

    Kuperman, Boris I.; Matey, Victoria E.; Fisher, Richard N.; Ervin, Edward L.; Warburton, Manna L.; Bakhireva, Ludmila; Lehman, Cynthia A.

    2004-01-01

    A total of 230 feral African clawed frogs, Xenopus laevis, from 3 localities in southern California were examined for parasites. The following species were found: 3 species of Protozoa, Nyctotherussp., Balantidium xenopodis, Protoopalina xenopodus; 2 species of Monogenea, Protopolystoma xenopodis, Gyrdicotylus gallieni; 1 species of Digenea, Clinostomum sp. (as metacercariae); 1 species of Cestoda, Cephalochlamys namaquensis; 2 species of Nematoda, Contracaecum sp. (as larvae), Eustrongylides sp. (as larvae); and 1 species of Acanthocephala, Acanthocephalus sp. (as cystacanth). Of these, the protozoans P. xenopodus and B. xenopodis, both monogeneans, and the cestode have an African origin. Contracaecum sp., Eustrongylides sp., and Acanthocephalus sp. have not been previously reported from X. laevis.

  2. The plumbotectonics of the West Shasta mining district, eastern Klamath Mountains, California ( USA).

    USGS Publications Warehouse

    Doe, B.R.; Delevaux, M.H.; Albers, J.P.

    1985-01-01

    The tectonic setting comprising the West Shasta mining district has often been compared with that of primitive island arcs. Concentrations of U, Th, and Pb and Pb isotope compositions were determined for Devonian ores and rocks of the West Shasta district, E Klamath Mountains, California, to help evaluate the tectonic classification. The lead isotope pattern is found to be complex. From comparison of the data with those on younger ores and rocks in the region and with those isotopic patterns found in modern tectonic terranes, however, a number of conclusions are described in detail. -after Authors

  3. 33 CFR 80.1126 - Santa Barbara Harbor, CA.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Santa Barbara Harbor, CA. 80.1126... NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1126 Santa Barbara Harbor, CA. A line drawn from Santa Barbara Harbor Light 4 to Santa Barbara Harbor Breakwater Light....

  4. Amphibian chytrid fungus (Batrachochytrium dendrobatidis) in coastal and montane California, USA Anurans

    USGS Publications Warehouse

    Fellers, Gary M.; Cole, Rebecca A.; Reinitz, David M.; Kleeman, Patrick M.

    2011-01-01

    We found amphibian chytrid fungus (Bd = Batrachochytrium dendrobatidis) to be widespread within a coastalwatershed at Point Reyes National Seashore, California and within two high elevation watersheds at Yosemite NationalPark, California. Bd was associated with all six species that we sampled (Bufo boreas, B. canorus, Pseudacris regilla, Ranadraytonii, R. sierrae, and Lithobates catesbeianus). For those species sampled at 10 or more sites within a watershed, thepercentage of Bd-positive sites varied from a low of 20.7% for P. regilla at one Yosemite watershed to a high of 79.6% forP. regilla at the Olema watershed at Point Reyes. At Olema, the percent of Bd-positive water bodies declined each year ofour study (2005-2007). Because P. regilla was the only species found in all watersheds, we used that species to evaluatehabitat variables related to the sites where P. regilla was Bd-positive. At Olema, significant variables were year, length ofshoreline (perimeter), percentage cover of rooted vegetation, and water depth. At the two Yosemite watersheds, waterdepth, water temperature, and silt/mud were the most important covariates, though the importance of these three factorsdiffered between the two watersheds. The presence of Bd in species that are not declining suggests that some of theamphibians in our study were innately resistant to Bd, or had developed resistance after Bd became established.

  5. Accumulation of pesticides in pacific chorus frogs (Pseudacris regilla) from California's Sierra Nevada Mountains, USA

    USGS Publications Warehouse

    Smalling, Kelly L.; Fellers, Gary M.; Kleeman, Patrick M.; Kuivila, Kathryn

    2013-01-01

    Pesticides are receiving increasing attention as potential causes of amphibian declines, acting singly or in combination with other stressors, but limited information is available on the accumulation of current-use pesticides in tissue. The authors examined potential exposure and accumulation of currently used pesticides in pond-breeding frogs (Pseudacris regilla) collected from 7 high elevations sites in northern California. All sites sampled are located downwind of California's highly agricultural Central Valley and receive inputs of pesticides through precipitation and/or dry deposition. Whole frog tissue, water, and sediment were analyzed for more than 90 current-use pesticides and pesticide degradates using gas chromatography–mass spectrometry. Two fungicides, pyraclostrobin and tebuconazole, and one herbicide, simazine, were the most frequently detected pesticides in tissue samples. Median pesticide concentration ranged from 13 µg/kg to 235 µg/kg wet weight. Tebuconazole and pyraclostrobin were the only 2 compounds observed frequently in frog tissue and sediment. Significant spatial differences in tissue concentration were observed, which corresponded to pesticide use in the upwind counties. Data generated indicated that amphibians residing in remote locations are exposed to and capable of accumulating current-use pesticides. A comparison of P. regilla tissue concentrations with water and sediment data indicated that the frogs are accumulating pesticides and are potentially a more reliable indicator of exposure to this group of pesticides than either water or sediment.

  6. Prevalence of eustrongylidosis in wading birds from colonies in California, Texas, and Rhode Island, USA

    USGS Publications Warehouse

    Franson, J.C.; Custer, T.W.

    1994-01-01

    Snowy Egret (Egretta thula) and Black-crowned Night-Heron (Nycticorax nycticorax) nestlings from colonies in Texas, Rhode Island, and California and Great Egret (Casmerodius albus) nestlings from Texas were examined for eustrongylidosis, or infection by the parasitic nematode Eustrongylides spp. In 31% (24/77) of all broods examined, at least one nestling was infected. Snowy Egret broods from Texas were more frequently (100%) infected than those from California (20%) or Rhode Island (10%), and the prevalence of eustrongylidosis in 5- and 10-day-old Snowy Egret nestlings was higher in the Texas colony than the other two. Within the Texas colony, the frequency of eustrongylidosis was greater for Snowy Egret (100%) and Great Egret (80%) broods than for Black-crowned Night-Heron broods (12.5%). Also in Texas, eustrongylidosis was more frequent in 5-day-old Snowy Egret nestlings than 5-day-old Black-crowned Night-Heron or Great Egret nestlings, and in 10-day-old Snowy Egret nestlings than in 10-day-old Black-crowned Night-Heron nestlings. Eustrongylides spp. caused perforations of the gastrointestinal tract and peritonitis, particularly in Snowy Egrets.

  7. Processes of coastal bluff erosion in weakly lithified sands, Pacifica, California, USA

    USGS Publications Warehouse

    Collins, B.D.; Sitar, N.

    2008-01-01

    Coastal bluff erosion and landsliding are currently the major geomorphic processes sculpting much of the marine terrace dominated coastline of northern California. In this study, we identify the spatial and temporal processes responsible for erosion and landsliding in an area of weakly lithified sand coastal bluffs located south of San Francisco, California. Using the results of a five year observational study consisting of site visits, terrestrial lidar scanning, and development of empirical failure indices, we identify the lithologic and process controls that determine the failure mechanism and mode for coastal bluff retreat in this region and present concise descriptions of each process. Bluffs composed of weakly cemented sands (unconfined compressive strength - UCS between 5 and 30??kPa) fail principally due to oversteepening by wave action with maximum slope inclinations on the order of 65 at incipient failure. Periods of significant wave action were identified on the basis of an empirical wave run-up equation, predicting failure when wave run-up exceeds the seasonal average value and the bluff toe elevation. The empirical relationship was verified through recorded observations of failures. Bluffs composed of moderately cemented sands (UCS up to 400??kPa) fail due to precipitation-induced groundwater seepage, which leads to tensile strength reduction and fracture. An empirical rainfall threshold was also developed to predict failure on the basis of a 48-hour cumulative precipitation index but was found to be dependent on a time delay in groundwater seepage in some cases.

  8. Accumulation of pesticides in Pacific chorus frogs (Pseudacris regilla) from California's Sierra Nevada Mountains, USA.

    PubMed

    Smalling, Kelly L; Fellers, Gary M; Kleeman, Patrick M; Kuivila, Kathryn M

    2013-09-01

    Pesticides are receiving increasing attention as potential causes of amphibian declines, acting singly or in combination with other stressors, but limited information is available on the accumulation of current-use pesticides in tissue. The authors examined potential exposure and accumulation of currently used pesticides in pond-breeding frogs (Pseudacris regilla) collected from 7 high elevations sites in northern California. All sites sampled are located downwind of California's highly agricultural Central Valley and receive inputs of pesticides through precipitation and/or dry deposition. Whole frog tissue, water, and sediment were analyzed for more than 90 current-use pesticides and pesticide degradates using gas chromatography-mass spectrometry. Two fungicides, pyraclostrobin and tebuconazole, and one herbicide, simazine, were the most frequently detected pesticides in tissue samples. Median pesticide concentration ranged from 13 µg/kg to 235 µg/kg wet weight. Tebuconazole and pyraclostrobin were the only 2 compounds observed frequently in frog tissue and sediment. Significant spatial differences in tissue concentration were observed, which corresponded to pesticide use in the upwind counties. Data generated indicated that amphibians residing in remote locations are exposed to and capable of accumulating current-use pesticides. A comparison of P. regilla tissue concentrations with water and sediment data indicated that the frogs are accumulating pesticides and are potentially a more reliable indicator of exposure to this group of pesticides than either water or sediment.

  9. Pyrethroid insecticide concentrations and toxicity in streambed sediments and loads in surface waters of the San Joaquin Valley, California, USA

    USGS Publications Warehouse

    Domagalski, J.L.; Weston, D.P.; Zhang, M.; Hladik, M.

    2010-01-01

    Pyrethroid insecticide use in California, USA, is growing, and there is a need to understand the fate of these compounds in the environment. Concentrations and toxicity were assessed in streambed sediment of the San Joaquin Valley of California, one of the most productive agricultural regions of the United States. Concentrations were also measured in the suspended sediment associated with irrigation or storm-water runoff, and mass loads during storms were calculated. Western valley streambed sediments were frequently toxic to the amphipod, Hyalella azteca, with most of the toxicity attributable to bifenthrin and cyhalothrin. Up to 100% mortality was observed in some locations with concentrations of some pyrethroids up to 20 ng/g. The western San Joaquin Valley streams are mostly small watersheds with clay soils, and sediment-laden irrigation runoff transports pyrethroid insecticides throughout the growing season. In contrast, eastern tributaries and the San Joaquin River had low bed sediment concentrations (<1 ng/g) and little or no toxicity because of the preponderance of sandy soils and sediments. Bifenthrin, cyhalothrin, and permethrin were the most frequently detected pyrethroids in irrigation and storm water runoff. Esfenvalerate, fenpropathrin, and resmethrin were also detected. All sampled streams contributed to the insecticide load of the San Joaquin River during storms, but some compounds detected in the smaller creeks were not detected in the San Joaquin River. The two smallest streams, Ingram and Hospital Creeks, which had high sediment toxicity during the irrigation season, accounted for less than 5% of the total discharge of the San Joaquin River during storm conditions, and as a result their contribution to the pyrethroid mass load of the larger river was minimal. ?? 2010 SETAC.

  10. Map of the Carpinteria area and vicinity, Santa Barbara County, California, showing water-level contours for March 1983, and net change in water level between March 1982 and March 1983

    USGS Publications Warehouse

    Moyle, W.R.

    1984-01-01

    A water-level contour map of the Carpinteria area, California, was constructed using 34 water-level measurements made by the Carpinteria County Water District in March 1983. Also shown on the map are five hydrographs that show water-level fluctuations in each well between 1978 and 1983. In addition, a water-level net-change map for March 1982 to March 1983 is shown. (USGS)

  11. New Tsunami Response, Mitigation, and Recovery Planning "Playbooks" for California (USA) Maritime Communities

    NASA Astrophysics Data System (ADS)

    Wilson, R. I.; Lynett, P. J.; Miller, K.; Eskijian, M.; Dengler, L. A.; Ayca, A.; Keen, A.; Admire, A. R.; Siegel, J.; Johnson, L. A.; Curtis, E.; Hornick, M.

    2015-12-01

    The 2010 Chile and 2011 Japan tsunamis both struck the California coast offering valuable experience and raised a number of significant issues for harbor masters, port captains, and other maritime entities. There was a general call for more planning products to help guide maritime communities in their tsunami response, mitigation, and recovery activities. The State of California is working with the U.S. Federal Emergency Management Agency (FEMA), the U.S. National Tsunami Hazard Mitigation Program (NTHMP), and other tsunami experts to provide communities with new tsunami planning tools to address these issues: Response Playbooks and plans have been developed for ports and harbors identifying potential tsunami current hazards and related damage for various size events. Maps have been generated showing minor, moderate, and severe damage levels that have been linked to current velocity thresholds of 3, 6, and 9 knots, respectively. Knowing this information allows harbor personnel to move ships or strengthen infrastructure prior to the arrival of distant source tsunamis. Damage probability tools and mitigation plans have been created to help reduce tsunami damage by evaluating the survivability of small and large vessels in harbors and ports. These results were compared to the actual damage assessments performed in California and Japan following the 2011 Japanese tsunami. Fragility curves were developed based on current velocity and direction to help harbor and port officials upgrade docks, piles, and related structures. Guidance documents are being generated to help in the development of both local and statewide recovery plans. Additional tools, like post-tsunami sediment and debris movement models, will allow harbors and ports to better understand if and where recovery issues are most likely to occur. Streamlining the regulatory and environmental review process is also a goal of the guidance. These maritime products and procedures are being integrated into guidance

  12. Diurnal, Seasonal and Inter-annual Variations of N2O Fluxes from Perennial Vineyard Soils in California, USA.

    NASA Astrophysics Data System (ADS)

    Suddick, E. C.; Carlisle, E. A.; Spencer, R. G.; Smart, D. R.

    2007-12-01

    The USA emits 1562 million metric tons of carbon equivalents a year, whereby this value is projected to rise by an estimated 14 % in 2012. California is the 12th major global emitter of greenhouse gases, emitting approximately 500 million metric tons of carbon equivalents a year. 84 % of greenhouse gas emissions are from CO2, 7 % and 6 % from N2O and CH4 respectively and approximately 8 % of these emissions are derived from agricultural activities. The concentration of nitrous oxide (N2O) within the atmosphere has been increasing at a rate of approximately 0.27 % per year and has mainly been attributed to agricultural practices such as land-use changes, biomass burning, nitrogen fertilization, livestock and manure management. Agriculture related activities generate from 6 to 35 Tg N2O-N per year, or about 60 to 70 % of global production. The primary biogenic sources of N2O are from terrestrial soils, which are thought to be a major source of N2O to the atmosphere and mainly involve the microbial nitrogen transformations brought about by nitrification and denitrification. The aim of this study was to quantify the seasonal and inter-annual variability of N2O emissions and nitrogen cycling from a conventionally tilled wine grape vineyard in Napa, California during a two year closed static chamber study and to also investigate the diurnal N2O flux pattern and effects of fertilization management practices on emissions within a table grape vineyard in Delano, California. Preliminary data shows that the annual N2O fluxes were influenced by soil properties, management practices and weather such as precipitation events where increases in N2O emissions were observed after irrigation or fertilization practices and immediately following rainfall. Vineyard floor and vine management will be discussed in terms of the significance management practices have upon the release of N2O emissions from vineyard soils where the high water and nitrogen fertilizer usage within these

  13. Miocene rapakivi granites in the southern Death Valley region, California, USA

    USGS Publications Warehouse

    Calzia, James P.; Ramo, O.T.

    2005-01-01

    Rapakivi granites in the southern Death Valley region, California, include the 12.4-Ma granite of Kingston Peak, the ca. 10.6-Ma Little Chief stock, and the 9.8-Ma Shoshone pluton. All of these granitic rocks are texturally zoned from a porphyritic rim facies, characterized by rapakivi textures and miarolitic cavities, to an equigranular aplite core. These granites crystallized from anhydrous and peraluminous to metaluminous magmas that were more oxidized and less alkalic than type rapakivi granites from southern Finland. Chemical and isotope (Nd–Sr–Pb) data suggest that rapakivi granites of the southern Death Valley region were derived by partial melting of lower crustal rocks (possibly including Mesozoic plutonic component) with some mantle input as well; they were emplaced at shallow crustal levels (4 km) in an actively extending orogen.

  14. Miocene rapakivi granites in the southern Death Valley region, California, USA

    USGS Publications Warehouse

    Calzia, J.P.; Ramo, O.T.

    2005-01-01

    Rapakivi granites in the southern Death Valley region, California, include the 12.4-Ma granite of Kingston Peak, the ca. 10.6-Ma Little Chief stock, and the 9.8-Ma Shoshone pluton. All of these granitic rocks are texturally zoned from a porphyritic rim facies, characterized by rapakivi textures and miarolitic cavities, to an equigranular aplite core. These granites crystallized from anhydrous and peraluminous to metaluminous magmas that were more oxidized and less alkalic than type rapakivi granites from southern Finland. Chemical and isotope (Nd-Sr-Pb) data suggest that rapakivi granites of the southern Death Valley region were derived by partial melting of lower crustal rocks (possibly including Mesozoic plutonic component) with some mantle input as well; they were emplaced at shallow crustal levels (4 km) in an actively extending orogen.

  15. Biogeochemical cycling of selenium in the San Joaquin Valley, California, USA

    USGS Publications Warehouse

    Presser, T.S.; Ohlendorf, H.M.

    1987-01-01

    Subsurface agricultural drainage waters from western San Joaquin Valley, California, were found to contain elevated concentrations of the element selenium in the form of selenate. In 1978, these drainage waters began to replace previous input to Kesterson Reservoir, a pond system within Kesterson National Wildlife Refuge; this substitution was completed by 1982. In the 1983 nesting season, unusual rates of deformity and death in embryos and hatchlings of wild aquatic birds (up to 64% of eared grebe and American coot nests) occurred at the refuge and were attributed to selenium toxicosis. Features necessary for contamination to have taken place included geologic setting, climate, soil type, availability of imported irrigation water, type of irrigation, and the unique chemical properties of selenium. The mechanisms of biogeochemical cycling raise questions about other ecosystems and human exposure.

  16. Potential toxicity concerns from chemical coagulation treatment of stormwater in the Tahoe basin, California, USA.

    PubMed

    Lopus, S E; Bachand, P A M; Heyvaert, A C; Werner, I; Teh, S J; Reuter, J E

    2009-10-01

    Coagulant dosing of stormwater runoff with polyaluminum chlorides (PACs) is used in numerous waterbodies to improve water clarity, but the potential risks of PACs to aquatic organisms in Lake Tahoe, California are not fully understood. To assess these risks, the USEPA 3-species toxicity test and a non-standard fish test using Japanese medaka (Oryzias latipes) were used to determine the toxicity of PAC-treated and non-treated stormwater samples to aquatic species. Stormwater samples were collected from three sites representing runoff from different urbanized areas in May 2004; samples received coagulant dosing using three different coagulants (JC1720, PAX-XL9, Sumalchlor50) at levels optimized with jar testing. Raw stormwaters were toxic to algae and fathead minnows (mortality). Treatment with coagulants increased toxicity to zooplankton (reproduction) and had no consistent effects on the other toxicity metrics.

  17. Sodium metasomatism along the Melones fault zone, Sierra Nevada foothills, California, USA

    USGS Publications Warehouse

    Albino, G.V.

    1995-01-01

    Albitite, locally aegirine- and riebeckite-bearing, formed as a result of sodium metasomatism of felsic dykes and argillites along the Melones Fault Zone near Jamestown, California. Pyrite, magnetite, hematite and titanite are common in small amounts in altered dykes. The dykes were originally plagioclase-hornblende porphyritic, and had major and trace element abundances typical of calc-alkaline rocks, whereas they now have Na2O contents as high as 11.40%. Mass balance calculations indicate that alteration involved addition of large amounts of sodium, and the removal of SiO2 and K2O. Textural preservation, combined with volume factors calculated from specific gravity and whole rock analytical data, indicate that Na-metasomatism was essentially isovolumetric. -from Author

  18. Mercury contamination in three species of anuran amphibians from the Cache Creek Watershed, California, USA.

    PubMed

    Hothem, Roger L; Jennings, Mark R; Crayon, John J

    2010-04-01

    Fish and wildlife may bioaccumulate mercury (Hg) to levels that adversely affect reproduction, growth, and survival. Sources of Hg within the Cache Creek Watershed in northern California have been identified, and concentrations of Hg in invertebrates and fish have been documented. However, bioaccumulation of Hg by amphibians has not been evaluated. In this study, adult and juvenile American bullfrogs (Lithobates catesbeianus) and foothill yellow-legged frogs (Rana boylii), adult Northern Pacific treefrogs (Pseudacris regilla), and larval bullfrogs were collected and analyzed for total Hg. One or more species of amphibians from 40% of the 35 sites had mean Hg concentrations greater than the US Environmental Protection Agency's tissue residue criterion for fish (0.3 microg/g). Of the bullfrog tissues analyzed, the liver had the highest concentrations of both total Hg and methyl mercury. Total Hg in carcasses of bullfrogs was highly correlated with total Hg in leg muscle, the tissue most often consumed by humans.

  19. Thirty-one years of debris-flow observation and monitoring near La Honda, California, USA

    USGS Publications Warehouse

    Wieczorek, G.F.; Wilson, R.C.; Ellen, S.D.; Reid, M.E.; Jayko, A.S.

    2007-01-01

    From 1975 until 2006,18 intense storms triggered at least 248 debris flows within 10 km2 northwest of the town of La Honda within the Santa Cruz Mountains, California. In addition to mapping debris flows and other types of landslides, studies included soil sampling and geologic mapping, piezometric and tensiometer monitoring, and rainfall measurement and recording. From 1985 until 1995, a system with radio telemetered rain gages and piezometers within the La Honda region was used for issuing six debris-flow warnings within the San Francisco Bay region through the NOAA ALERT system. Depending upon the relative intensity of rainfall during storms, debris flows were generated from deep slumps, shallow slumps, shallow slides in colluvium and shallow slides over bedrock. Analysis shows the storms with abundant antecedent rainfall followed by several days of steady heavy intense rainfall triggered the most abundant debris flows. ?? 2007 millpress.

  20. Increasing summer river discharge in southern California, USA, linked to urbanization

    NASA Astrophysics Data System (ADS)

    Townsend-Small, Amy; Pataki, Diane E.; Liu, Hongxing; Li, Zhaofu; Wu, Qiusheng; Thomas, Benjamin

    2013-09-01

    southern California relies heavily on imported water for domestic use. A synthesis of river discharge data in this region reveals that summer (June, July, and August) river discharge in watersheds that have at least 50% urban, suburban, and/or commercial land cover has increased by 250% or more over the past half-century, without any substantial precipitation during these months. Total annual discharge in the Los Angeles River has also increased at levels up to several hundred percent. Three factors likely contribute to our observations: (1) increased groundwater recharge rates from leaking water pipelines, (2) inputs of treated wastewater into streams and rivers, and (3) increased runoff or recharge due to over-irrigation of ornamental landscaping. In the southwestern United States, water importation consumes large amounts of energy and contributes to decline of river flows in source regions. Here we show that water importation also increases river flows in urban areas.

  1. Global positioning system surveying to monitor land subsidence in Sacramento Valley, California, USA

    USGS Publications Warehouse

    Ikehara, M.E.

    1994-01-01

    A subsidence research program began in 1985 to document the extent and magnitude of land subsidence in Sacramento Valley, California, an area of about 15 600 km2m, using Global Positioning System (GPS) surveying. In addition to periodic conventional spirit levelling, an examination was made of the changes in GPS-derived ellipsoidal height differences (summary differences) between pairs of adjacent bench marks in central Sacramento Valley from 1986 to 1989. The average rates of land subsidence in the southern Sacramento Valley for the past several decades were determined by comparing GPS-derived orthometric heights with historic published elevations. A maximum average rate of 0.053 m year-1 (0.90 m in 17 years) of subsidence has been measured. -Author

  2. Metals and trace elements in giant garter snakes (Thamnophis gigas) from the Sacramento Valley, California, USA

    USGS Publications Warehouse

    Wylie, G.D.; Hothem, R.L.; Bergen, D.R.; Martin, L.L.; Taylor, R.J.; Brussee, B.E.

    2009-01-01

    The giant garter snake (GGS; Thamnophis gigas) is a federally listed threatened species endemic to wetlands of the Central Valley of California. Habitat destruction has been the main factor in the decline of GGS populations, but the effects of contaminants on this species are unknown. To contribute to the recovery of these snakes, the U.S. Geological Survey (USGS) began studies of the life history and habitat use of GGSs in 1995. During a series of investigations conducted from 1995 to the present, specimens of dead GGSs were opportunistically collected from the Colusa National Wildlife Refuge (CNWR), the Natomas Basin, and other sites in northern California. Whole snakes were stored frozen for potential future analysis. As funding became available, we analyzed tissues of 23 GGSs to determine the concentrations of total mercury (Hg) and other trace elements in livers and concentrations of Hg in brains and tail clips. Mercury concentrations (??g/g, wet weight) ranged from 0.08 to 1.64 in livers, 0.01 to 0.18 in brains, and 0.02 to 0.32 in tail clips. In livers, geometric mean concentrations (??g/g, dry weight) of arsenic (25.7) and chromium (1.02) were higher than most values from studies of other snakes. Mercury concentrations in tail clips were positively correlated with concentrations in livers and brains, with the most significant correlations occurring at the Natomas Basin and when Natomas and CNWR were combined. Results indicate the value of using tail clips as a nonlethal bioindicator of contaminant concentrations. ?? 2008 US Government.

  3. Geology and mammalian paleontology of the Horned Toad Hills, Mojave Desert, California, USA

    USGS Publications Warehouse

    May, S.R.; Woodburne, M.O.; Lindsay, E.H.; Albright, L.B.; Sarna-Wojcicki, A.; Wan, E.; Wahl, D.B.

    2011-01-01

    The Horned Toad Formation includes five lithostratigraphic members that record alluvial fan, fluvial, lake margin, and lacustrine deposition within a relatively small basin just south of the active Garlock fault during the late Miocene to early Pliocene. These sediments experienced northwest-southeast contractional deformation during the Pliocene-Pleistocene associated with basement-involved reverse faults. Member Two of the Horned Toad Formation has yielded 24 taxa of fossil mammals, referred to as the Warren Local Fauna, including Cryptotis sp., cf. Scapanus, Hypolagus vetus, Hypolagus edensis,? Spermophilus sp., Prothomomys warrenensis n. gen., n. sp., Perognathus sp., Repomys gustelyi, Postcopemys valensis, Peromyscus sp. A, Peromyscus sp. B, Jacobsomys dailyi n. sp., Borophagus cf. B. secundus, cf. Agriotherium, Machairodus sp. cf. M. coloradensis, Rhynchotherium sp. cf. R. edensis, Pliomastodon vexillarius, Dinohippus edensis, Teleoceras sp. cf. T. fossiger, cf. Prosthennops, Megatylopus sp. cf. M. matthewi, Hemiauchenia vera, Camelidae gen. et. sp. indet., and the antilocaprid cf. Sphenophalos. The majority of fossil localities are confined to a 20 m thick stratigraphic interval within a reversed polarity magnetozone. The fauna demonstrates affinity with other late Hemphillian faunas from California, Nevada, Nebraska, Texas, and Mexico. The Lawlor Tuff, dated elsewhere in California at 4.83 ?? 0.04 Ma and geochemically identified in the Horned Toad Formation, overlies most of the fossil mammal localities. Magnetic polarity data are correlated with Chrons 3n.3r, 3n.3n, and 3n.2r, suggesting an age of approximately 5.0 - 4.6 Ma. These constraints indicate an age for the late Hemphillian Warren Local Fauna of 4.85 - 5.0 Ma. ?? Society of Vertebrate Paleontology November 2011.

  4. Determinants of polychlorinated biphenyls in dust from homes in California, USA.

    PubMed

    Whitehead, Todd P; Ward, Mary H; Colt, Joanne S; Nishioka, Marcia G; Buffler, Patricia A; Rappaport, Stephen M; Metayer, Catherine

    2013-02-01

    Polychlorinated biphenyl (PCB) production ceased in the U.S. over 30 years ago, but these persistent chemicals remain ubiquitous contaminants. Here, we evaluate potential determinants of PCB levels in dust from California homes including characteristics of the residence as well as the residents' habits and occupations. Dust was collected from 415 households as part of a large case-control study (the Northern California Childhood Leukaemia Study), using a high-volume small surface sampler. Dust concentrations of 6 PCBs (PCB-105, PCB-118, PCB-138, PCB-153, PCB-170, and PCB-180) were measured using gas chromatography-mass spectrometry. Individual PCB detection rates ranged from 9% to 54% with PCB concentrations ranging from below detection (1 or 2 ng g (-1)) to 270 ng g(-1) and PCB loadings ranging from below detection to 960 ng m (-2). Multivariable linear and logistic regression models were used to identify potential determinants of residential PCB contamination based on in-home interviews and residential geographic locations. We observed that residences built prior to 1980 had higher odds of PCB detection and higher PCB loadings than more recently constructed homes. Households where residents typically did not remove their shoes had higher PCB dust loadings than households where residents did. PCBs were less likely to be detected in carpet dust from households that had frequently vacuumed or replaced carpets compared to other households. Since we used a cross-sectional dust sampling protocol and report significant, but modest, effects of these determinants on levels of PCBs in residential dust, our results should be interpreted with caution. Longitudinal studies to determine optimal strategies for reducing PCBs in homes are warranted.

  5. Influence of Watershed Runoff on Nutrient Dynamics in a Southern California Salt Marsh

    NASA Astrophysics Data System (ADS)

    Page, Henry M.; Petty, Robert L.; Meade, Daniel E.

    1995-08-01

    The effect of freshwater runoff on nutrient loading and dynamics was studied in Carpinteria Salt Marsh, a typically small (93 ha) southern California, U.S.A., estuary adjoining a watershed supporting extensive agricultural and urban development. Concentrations of dissolved nitrate, but not ammonium or phosphate, were elevated in stream flow and perched groundwater in the watershed, relative to marsh surface waters. Loading of nitrate and particulate organic nitrogen (PON) from the watershed, but not ammonium or phosphate, increased as a function of stream discharge. Estimates of net nutrient exchange over selected tidal cycles suggested that the marsh exported nitrate, ammonium and PON to the Santa Barbara Channel. Nitrate and PON were advected from the watershed through the marsh while ammonium was produced within the marsh and exported. The availability of imported nitrogen for primary production may be limited by marsh tidal elevation as most nitrogen inputs are throughput to the Santa Barbara Channel.

  6. Chlorinated, brominated, and perfluorinated compounds, polycyclic aromatic hydrocarbons and trace elements in livers of sea otters from California, Washington, and Alaska (USA), and Kamchatka (Russia)

    USGS Publications Warehouse

    Kannan, K.; Moon, H.-B.; Yun, S.-H.; Agusa, T.; Thomas, N.J.; Tanabe, S.

    2008-01-01

    Concentrations of organochlorine pesticides (DDTs, HCHs, and chlordanes), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), polycyclic aromatic hydrocarbons (PAHs), perfluorinated compounds (PFCs), and 20 trace elements were determined in livers of 3- to 5-year old stranded sea otters collected from the coastal waters of California, Washington, and Alaska (USA) and from Kamchatka (Russia). Concentrations of organochlorine pesticides, PCBs, and PBDEs were high in sea otters collected from the California coast. Concentrations of DDTs were 10-fold higher in California sea otters than in otters from other locations; PCB concentrations were 5-fold higher, and PBDE concentrations were 2-fold higher, in California sea otters than in otters from other locations. Concentrations of PAHs were higher in sea otters from Prince William Sound than in sea otters from other locations. Concentrations of several trace elements were elevated in sea otters collected from California and Prince William Sound. Elevated concentrations of Mn and Zn in sea otters from California and Prince William Sound were indicative of oxidative stress-related injuries in these two populations. Concentrations of all of the target compounds, including trace elements, that were analyzed in sea otters from Kamchatka were lower than those found from the US coastal locations. ?? The Royal Society of Chemistry.

  7. Chlorinated, brominated, and perfluorinated compounds, polycyclic aromatic hydrocarbons and trace elements in livers of sea otters from California, Washington, and Alaska (USA), and Kamchatka (Russia).

    PubMed

    Kannan, Kurunthachalam; Moon, Hyo-Bang; Yun, Se Hun; Agusa, Tetsuro; Thomas, Nancy J; Tanabe, Shinsuke

    2008-04-01

    Concentrations of organochlorine pesticides (DDTs, HCHs, and chlordanes), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), polycyclic aromatic hydrocarbons (PAHs), perfluorinated compounds (PFCs), and 20 trace elements were determined in livers of 3- to 5-year old stranded sea otters collected from the coastal waters of California, Washington, and Alaska (USA) and from Kamchatka (Russia). Concentrations of organochlorine pesticides, PCBs, and PBDEs were high in sea otters collected from the California coast. Concentrations of DDTs were 10-fold higher in California sea otters than in otters from other locations; PCB concentrations were 5-fold higher, and PBDE concentrations were 2-fold higher, in California sea otters than in otters from other locations. Concentrations of PAHs were higher in sea otters from Prince William Sound than in sea otters from other locations. Concentrations of several trace elements were elevated in sea otters collected from California and Prince William Sound. Elevated concentrations of Mn and Zn in sea otters from California and Prince William Sound were indicative of oxidative stress-related injuries in these two populations. Concentrations of all of the target compounds, including trace elements, that were analyzed in sea otters from Kamchatka were lower than those found from the US coastal locations.

  8. Recent rates of carbon accumulation in montane fens ofYosemite National Park, California, U.S.A.

    USGS Publications Warehouse

    Drexler, Judith; Fuller, Christopher C.; Orlando, James L.; Moore, Peggy E.

    2016-01-01

    Little is known about recent rates of carbon storage in montane peatlands, particularly in the western United States. Here we report on recent rates of carbon accumulation (past 50 to 100 years) in montane groundwater-fed peatlands (fens) of Yosemite National Park in central California, U.S.A. Peat cores were collected at three sites ranging in elevation from 2070 to 2500 m. Core sections were analyzed for bulk density, % organic carbon, and 210Pb activities for dating purposes. Organic carbon densities ranged from 0.026 to 0.065 g C cm-3. Mean vertical accretion rates estimated using210Pb over the 50-year period from ∼1960 to 2011 and the 100-year period from ∼1910 to 2011 were 0.28 (standard deviation = ±0.09) and 0.18 (±-0.04) cm yr-1, respectively. Mean carbon accumulation rates over the 50- and 100-year periods were 95.4 (±25.4) and 74.7 (±17.2) g C m-2 yr-1, respectively. Such rates are similar to recent rates of carbon accumulation in rich fens in western Canada, but more studies are needed to definitively establish both the similarities and differences in peat formation between boreal and temperate montane fens.

  9. Sediment quality assessment in tidal salt marshes in northern California, USA: An evaluation of multiple lines of evidence approach

    USGS Publications Warehouse

    Hwang, Hyun-Min; Carr, Robert S.; Cherr, Gary N.; Green, Peter G.; Grosholz, Edwin G.; Judah, Linda; Morgan, Steven G.; Ogle, Scott; Rashbrook, Vanessa K.; Rose, Wendy L.; Teh, Swee J.; Vines, Carol A.; Anderson, Susan L.

    2013-01-01

    The objective of this study was to evaluate the efficacy of integrating a traditional sediment quality triad approach with selected sublethal chronic indicators in resident species in assessing sediment quality in four salt marshes in northern California, USA. These included the highly contaminated (Stege Marsh) and relatively clean (China Camp) marshes in San Francisco Bay and two reference marshes in Tomales Bay. Toxicity potential of contaminants and benthic macroinvertebrate survey showed significant differences between contaminated and reference marshes. Sublethal responses (e.g., apoptotic DNA fragmentation, lipid accumulation, and glycogen depletion) in livers of longjaw mudsucker (Gillichthys mirabilis) and embryo abnormality in lined shore crab (Pachygrapsus crassipes) also clearly distinguished contaminated and reference marshes, while other responses (e.g., cytochrome P450, metallothionein) did not. This study demonstrates that additional chronic sublethal responses in resident species under field exposure conditions can be readily combined with sediment quality triads for an expanded multiple lines of evidence approach. This confirmatory step may be warranted in environments like salt marshes in which natural variables may affect interpretation of toxicity test data. Qualitative and quantitative integration of the portfolio of responses in resident species and traditional approach can support a more comprehensive and informative sediment quality assessment in salt marshes and possibly other habitat types as well.

  10. Polychlorinated biphenyls and toxaphene in Pacific tree frog tadpoles (Hyla regilla) from the California Sierra Nevada, USA.

    PubMed

    Angermann, Jeffrey E; Fellers, Gary M; Matsumura, Fumio

    2002-10-01

    Pacific tree frog (Hyla regilla) tadpoles were collected throughout the Sierra Nevada mountain range, California, USA, in 1996 and 1997 and analyzed for the presence of polychlorinated biphenyls (PCBs) and toxaphene. Whole-tadpole sigma PCB levels ranged from 244 ng/g (wet wt) at lower elevations on the western slope to 1.6 ng/g high on the eastern slope, whereas sigma toxaphene levels ranged from 15.6 to 1.5 ng/g. Linear regression of PCB and toxaphene residue levels versus elevation indicated a significant relationship, with an r2 value of 0.33 for PCB and 0.45 for toxaphene indicating a significant elevation effect on PCB and toxaphene bioaccumulation in Sierra Nevada H. regilla. Tadpole samples from sites in east-facing versus west-facing drainage basins showed significant differences in PCB and toxaphene residue levels, suggesting the possibility of a rain-shadow effect in the long-range atmospheric transport of these contaminants to the Sierra Nevada Mountains.

  11. Polychlorinated biphenyls and toxaphene in Pacific tree frog tadpoles (Hyla regilla) from the California Sierra Nevada, USA

    USGS Publications Warehouse

    Angermann, Jeffrey E.; Fellers, Gary M.; Matsumura, Fumio

    2002-01-01

    Pacific tree frog (Hyla regilla) tadpoles were collected throughout the Sierra Nevada mountain range, California, USA, in 1996 and 1997 and analyzed for the presence of polychlorinated biphenyls (PCBs) and toxaphene. Whole-tadpole Σ PCB levels ranged from 244 ng/g (wet wt) at lower elevations on the western slope to 1.6 ng/g high on the eastern slope, whereas Σ toxaphene levels ranged from 15.6 to 1.5 ng/g. Linear regression of PCB and toxaphene residue levels versus elevation indicated a significant relationship, with an r2 value of 0.33 for PCB and 0.45 for toxaphene indicating a significant elevation effect on PCB and toxaphene bioaccumulation in Sierra Nevada H. regilla. Tadpole samples from sites in east-facing versus west-facing drainage basins showed significant differences in PCB and toxaphene residue levels, suggesting the possibility of a rain-shadow effect in the long-range atmospheric transport of these contaminants to the Sierra Nevada Mountains.

  12. Testing alternative conceptual models of seawater intrusion in a coastal aquifer using computer simulation, southern California, USA

    USGS Publications Warehouse

    Nishikawa, T.

    1997-01-01

    Two alternative conceptual models of the physical processes controlling seawater intrusion in a coastal basin in California, USA, were tested to identify a likely principal pathway for seawater intrusion. The conceptual models were tested by using a two-dimensional, finite-element groundwater flow and transport model. This pathway was identified by the conceptual model that best replicated the historical data. The numerical model was applied in cross section to a submarine canyon that is a main avenue for seawater to enter the aquifer system underlying the study area. Both models are characterized by a heterogeneous, layered, water-bearing aquifer. However, the first model is characterized by flat-lying aquifer layers and by a high value of hydraulic conductivity in the basal aquifer layer, which is thought to be a principal conduit for seawater intrusion. The second model is characterized by offshore folding, which was modeled as a very nearshore outcrop, thereby providing a shorter path for seawater to intrude. General conclusions are that: 1) the aquifer system is best modeled as a flat, heterogeneous, layered system; 2) relatively thin basal layers with relatively high values of hydraulic conductivity are the principal pathways for seawater intrusion; and 3) continuous clay layers of low hydraulic conductivity play an important role in controlling the movement of seawater.

  13. Influences of the unsaturated, saturated, and riparian zones on the transport of nitrate near the Merced River, California, USA

    NASA Astrophysics Data System (ADS)

    Domagalski, Joseph L.; Phillips, Steven P.; Bayless, E. Randall; Zamora, Celia; Kendall, Carol; Wildman, Richard A.; Hering, Janet G.

    2008-06-01

    Transport and transformation of nitrate was evaluated along a 1-km groundwater transect from an almond orchard to the Merced River, California, USA, within an irrigated agricultural setting. As indicated by measurements of pore-water nitrate and modeling using the root zone water quality model, about 63% of the applied nitrogen was transported through a 6.5-m unsaturated zone. Transport times from recharge locations to the edge of a riparian zone ranged from approximately 6 months to greater than 100 years. This allowed for partial denitrification in horizons having mildly reducing conditions, and essentially no denitrification in horizons with oxidizing conditions. Transport times across a 50-100-m-wide riparian zone of less than a year to over 6 years and more strongly reducing conditions resulted in greater rates of denitrification. Isotopic measurements and concentrations of excess N2 in water were indicative of denitrification with the highest rates below the Merced River. Discharge of water and nitrate into the river was dependent on gradients driven by irrigation or river stage. The results suggest that the assimilative capacity for nitrate of the groundwater system, and particularly the riverbed, is limiting the nitrate load to the Merced River in the study area.

  14. Influences of the unsaturated, saturated, and riparian zones on the transport of nitrate near the Merced River, California, USA

    USGS Publications Warehouse

    Domagalski, J.L.; Phillips, S.P.; Bayless, E.R.; Zamora, C.; Kendall, C.; Wildman, R.A.; Hering, J.G.

    2008-01-01

    Transport and transformation of nitrate was evaluated along a 1-km groundwater transect from an almond orchard to the Merced River, California, USA, within an irrigated agricultural setting. As indicated by measurements of pore-water nitrate and modeling using the root zone water quality model, about 63% of the applied nitrogen was transported through a 6.5-m unsaturated zone. Transport times from recharge locations to the edge of a riparian zone ranged from approximately 6 months to greater than 100 years. This allowed for partial denitrification in horizons having mildly reducing conditions, and essentially no denitrification in horizons with oxidizing conditions. Transport times across a 50-100-m-wide riparian zone of less than a year to over 6 years and more strongly reducing conditions resulted in greater rates of denitrification. Isotopic measurements and concentrations of excess N2 in water were indicative of denitrification with the highest rates below the Merced River. Discharge of water and nitrate into the river was dependent on gradients driven by irrigation or river stage. The results suggest that the assimilative capacity for nitrate of the groundwater system, and particularly the riverbed, is limiting the nitrate load to the Merced River in the study area. ?? Springer-Verlag 2007.

  15. Storm surges and climate change implications for tidal marshes: Insight from the San Francisco Bay Estuary, California, USA

    USGS Publications Warehouse

    Thorne, Karen M.; Buffington, Kevin J.; Swanson, Kathleen; Takekawa, John Y.

    2013-01-01

    Tidal marshes are dynamic ecosystems, which are influenced by oceanic and freshwater processes and daily changes in sea level. Projected sea-level rise and changes in storm frequency and intensity will affect tidal marshes by altering suspended sediment supply, plant communities, and the inundation duration and depth of the marsh platform. The objective of this research was to evaluate if regional weather conditions resulting in low-pressure storms changed tidal conditions locally within three tidal marshes. We hypothesized that regional storms will increase sea level heights locally, resulting in increased inundation of the tidal marsh platform and plant communities. Using site-level measurements of elevation, plant communities, and water levels, we present results from two storm events in 2010 and 2011 from the San Francisco Bay Estuary (SFBE), California, USA. The January 2010 storm had the lowest recorded sea level pressure in the last 30 years for this region. During the storm episodes, the duration of tidal marsh inundation was 1.8 and 3.1 times greater than average for that time of year, respectively. At peak storm surges, over 65% in 2010 and 93% in 2011 of the plant community was under water. We also discuss the implications of these types of storms and projected sea-level rise on the structure and function of the tidal marshes and how that will impact the hydro-geomorphic processes and marsh biotic communities.

  16. Landscape position influences soil respiration variability and sensitivity to physiological drivers in mixed-use lands of Southern California, USA

    NASA Astrophysics Data System (ADS)

    Crum, Steven M.; Liang, Liyin L.; Jenerette, G. Darrel

    2016-10-01

    Linking variation in ecosystem functioning to physiological and landscape drivers has become an important research need for understanding ecosystem responses to global changes. We investigate how these contrasting scale-dependent ecosystem drivers influence soil respiration (Rs), a key ecosystem process, using in situ landscape surveys and experimental subsidies of water and labile carbon. Surveys and experiments were conducted in summer and winter seasons and were distributed along a coastal to desert climate gradient and among the dominant land use classes in Southern California, USA. We found that Rs decreased from lawn to agricultural and wildland land uses for both seasons and along the climate gradient in the summer while increasing along the climate gradient in the winter. Rs variation was positively correlated with soil temperature and negatively to soil moisture and substrate. Water additions increased Rs in wildland land uses, while urban land uses responded little or negatively. However, most land uses exhibited carbon limitation, with wildlands experiencing largest responses to labile carbon additions. These findings show that intensively managed land uses have increased rates, decreased spatial variation, and decreased sensitivity to environmental conditions in Rs compared to wildlands, while increasing aridity has the opposite effect. In linking scales, physiological drivers were correlated with Rs but landscape position influenced Rs by altering both the physiological drivers and the sensitivity to the drivers. Systematic evaluation of physiological and landscape variation provides a framework for understanding the effects of interactive global change drivers to ecosystem metabolism across multiple scales.

  17. Sediment quality assessment in tidal salt marshes in northern California, USA: an evaluation of multiple lines of evidence approach.

    PubMed

    Hwang, Hyun-Min; Carr, R Scott; Cherr, Gary N; Green, Peter G; Grosholz, Edwin D; Judah, Linda; Morgan, Steven G; Ogle, Scott; Rashbrook, Vanessa K; Rose, Wendy L; Teh, Swee J; Vines, Carol A; Anderson, Susan L

    2013-06-01

    The objective of this study was to evaluate the efficacy of integrating a traditional sediment quality triad approach with selected sublethal chronic indicators in resident species in assessing sediment quality in four salt marshes in northern California, USA. These included the highly contaminated (Stege Marsh) and relatively clean (China Camp) marshes in San Francisco Bay and two reference marshes in Tomales Bay. Toxicity potential of contaminants and benthic macroinvertebrate survey showed significant differences between contaminated and reference marshes. Sublethal responses (e.g., apoptotic DNA fragmentation, lipid accumulation, and glycogen depletion) in livers of longjaw mudsucker (Gillichthys mirabilis) and embryo abnormality in lined shore crab (Pachygrapsus crassipes) also clearly distinguished contaminated and reference marshes, while other responses (e.g., cytochrome P450, metallothionein) did not. This study demonstrates that additional chronic sublethal responses in resident species under field exposure conditions can be readily combined with sediment quality triads for an expanded multiple lines of evidence approach. This confirmatory step may be warranted in environments like salt marshes in which natural variables may affect interpretation of toxicity test data. Qualitative and quantitative integration of the portfolio of responses in resident species and traditional approach can support a more comprehensive and informative sediment quality assessment in salt marshes and possibly other habitat types as well.

  18. Diel cycles of hydrogen peroxide in marine bathing waters in Southern California, USA: in situ surf zone measurements.

    PubMed

    Clark, Catherine D; De Bruyn, Warren J; Hirsch, Charlotte M; Aiona, Paige

    2010-12-01

    Hydrogen peroxide is photochemically produced in natural waters. It has been implicated in the oxidative-induced mortality of fecal indicator bacteria (FIB), a microbial water quality measure. To assess levels and cycling of peroxide in beach waters monitored for FIB, diel studies were carried out in surf zone waters in July 2009 at Crystal Cove State Beach, Southern California, USA. Maximum concentrations of 160-200 nM were obtained within 1h of solar noon. Levels dropped at night to 20-40 nM, consistent with photochemical production from sunlight. Day-time production and night-time dark loss rates averaged 16 ± 3 nM h(-1) and 12 ± 4 nM h(-1) respectively. Apparent quantum yields averaged 0.07 ± 0.02. Production was largely dominated by sunlight, with some dependence on chromophoric dissolved organic matter (CDOM) levels in waters with high absorption coefficients. Peroxide levels measured here are sufficient to cause oxidative-stress-induced mortality of bacteria, affect FIB diel cycling and impact microbial water quality in marine bathing waters.

  19. Stratigraphic controls on seawater intrusion and implications for groundwater management, Dominguez Gap area of Los Angeles, California, USA

    USGS Publications Warehouse

    Nishikawa, T.; Siade, A.J.; Reichard, E.G.; Ponti, D.J.; Canales, A.G.; Johnson, T.A.

    2009-01-01

    Groundwater pumping has led to extensive water-level declines and seawater intrusion in coastal Los Angeles, California (USA). A SUTRA-based solute-transport model was developed to test the hydraulic implications of a sequence-stratigraphic model of the Dominguez Gap area and to assess the effects of water-management scenarios. The model is two-dimensional, vertical and follows an approximate flow line extending from the Pacific Ocean through the Dominguez Gap area. Results indicate that a newly identified fault system can provide a pathway for transport of seawater and that a stratigraphic boundary located between the Bent Spring and Upper Wilmington sequences may control the vertical movement of seawater. Three 50-year water-management scenarios were considered: (1) no change in water-management practices; (2) installation of a slurry wall; and (3) raising inland water levels to 7.6 m above sea level. Scenario 3 was the most effective by reversing seawater intrusion. The effects of an instantaneous 1-m sea-level rise were also tested using water-management scenarios 1 and 3. Results from two 100-year simulations indicate that a 1-m sea-level rise may accelerate seawater intrusion for scenario 1; however, scenario 3 remains effective for controlling seawater intrusion. ?? Springer-Verlag 2009.

  20. Gaining the necessary geologic, hydrologic, and geochemical understanding for additional brackish groundwater development, coastal San Diego, California, USA

    USGS Publications Warehouse

    Danskin, Wesley R.

    2012-01-01

    Local water agencies and the United States Geological Survey are using a combination of techniques to better understand the scant freshwater resources and the much more abundant brackish resources in coastal San Diego, California, USA. Techniques include installation of multiple-depth monitoring well sites; geologic and paleontological analysis of drill cuttings; geophysical logging to identify formations and possible seawater intrusion; sampling of pore-water obtained from cores; analysis of chemical constituents including trace elements and isotopes; and use of scoping models including a three-dimensional geologic framework model, rainfall-runoff model, regional groundwater flow model, and coastal density-dependent groundwater flow model. Results show that most fresh groundwater was recharged during the last glacial period and that the coastal aquifer has had recurring intrusions of fresh and saline water. These intrusions disguise the source, flowpaths, and history of ground water near the coast. The flow system includes a freshwater lens resting on brackish water; a 100-meter-thick flowtube of freshwater discharging under brackish estuarine water and above highly saline water; and broad areas of fine-grained coastal sediment filled with fairly uniform brackish water. Stable isotopes of hydrogen and oxygen indicate the recharged water flows through many kilometers of fractured crystalline rock before entering the narrow coastal aquifer.

  1. Pesticides in mountain yellow-legged frogs (Rana muscosa) from the Sierra Nevada Mountains of California, USA

    USGS Publications Warehouse

    Fellers, G.M.; McConnell, L.L.; Pratt, D.; Datta, S.

    2004-01-01

    In 1997, pesticide concentrations were measured in mountain yellow-legged frogs (Rana muscosa) from two areas in the Sierra Nevada Mountains of California, USA. One area (Sixty Lakes Basin, Kings Canyon National Park) had large, apparently healthy populations of frogs. A second area (Tablelands, Sequoia National Park) once had large populations, but the species had been extirpated from this area by the early 1980s. The Tablelands is exposed directly to prevailing winds from agricultural regions to the west. When an experimental reintroduction of R. muscosa in 1994 to 1995 was deemed unsuccessful in 1997, the last 20 (reintroduced) frogs that could be found were collected from the Tablelands, and pesticide concentrations in both frog tissue and the water were measured at both the Tablelands and at reference sites at Sixty Lakes. In frog tissues, dichlorodiphenyldichloroethylene (DDE) concentration was one to two orders of magnitude higher than the other organochlorines (46 ?? 20 ng/g wet wt at Tablelands and 17 ?? 8 Sixty Lakes). Both ??-chlordane and trans-nonachlor were found in significantly greater concentrations in Tablelands frog tissues compared with Sixty Lakes. Organophosphate insecticides, chlorpyrifos, and diazinon were observed primarily in surface water with higher concentrations at the Tablelands sites. No contaminants were significantly higher in our Sixty Lakes samples.

  2. Behaviour of wintering Tundra Swans Cygnus columbianus columbianus at the Eel River delta and Humboldt Bay, California, USA

    USGS Publications Warehouse

    Black, Jeffrey M.; Gress, Carol; Byers, Jacob W.; Jennings, Emily; Ely, Craig

    2010-01-01

    Tundra Swan Cygnus columbianus columbinanus phenology and behaviour at the Eel River delta and southern Humboldt Bay in northern California, USA, is described. Counts made each January from 1963 onwards peaked at 1,502 swans in 1988. Monthly counts recorded during the 2006/07 and 2008/09 winters peaked in February, at 1,033 and 772 swans respectively. Swans roosted on ephemeral ponds at the Humboldt Bay National Wildlife Refuge, on ephemeral ponds within grassland pastures in the vicinity of the Refuge, and perhaps also used the Eel River as a roost. Flights between Refuge roosts and the pastures and ponds occurred in the two hours after sunrise and before dark. In winters 2008/09 and 2009/10, the percentage of cygnets in the flocks was 10.6% and 21.4% respectively, and increased to =31% cygnets each year after most swans had departed from the area in March. Average brood size in 2009/10 was 2.1 cygnets. Daily activities consisted of foraging (44.9% of activities recorded), comfort behaviour (22.1%), locomotion (16.2%) and vigilance (15.5%). Eight neck-collared swans identified in the wintering flock were marked at four locations in different parts of Alaska, up to 1,300 km apart.

  3. Contrasting rainfall generated debris flows from adjacent watersheds at Forest Falls, southern California, USA

    NASA Astrophysics Data System (ADS)

    Morton, Douglas M.; Alvarez, Rachel M.; Ruppert, Kelly R.; Goforth, Brett

    2008-04-01

    Debris flows are widespread and common in many steeply sloping areas of southern California. The San Bernardino Mountains community of Forest Falls is probably subject to the most frequently documented debris flows in southern California. Debris flows at Forest Falls are generated during short-duration high-intensity rains that mobilize surface material. Except for debris flows on two consecutive days in November 1965, all the documented historic debris flows have occurred during high-intensity summer rainfall, locally referred to as 'monsoon' or 'cloudburst' rains. Velocities of the moving debris range from about 5 km/h to about 90 km/h. Velocity of a moving flow appears to be essentially a function of the water content of the flow. Low velocity debris flows are characterized by steep snouts that, when stopped, have only small amounts of water draining from the flow. In marked contrast are high-velocity debris flows whose deposits more resemble fluvial deposits. In the Forest Falls area two adjacent drainage basins, Snow Creek and Rattlesnake Creek, have considerably different histories of debris flows. Snow Creek basin, with an area about three times as large as Rattlesnake Creek basin, has a well developed debris flow channel with broad levees. Most of the debris flows in Snow Creek have greater water content and attain higher velocities than those of Rattlesnake Creek. Most debris flows are in relative equilibrium with the geometry of the channel morphology. Exceptionally high-velocity flows, however, overshoot the channel walls at particularly tight channel curves. After overshooting the channel, the flows degrade the adjacent levee surface and remove trees and structures in the immediate path, before spreading out with decreasing velocity. As the velocity decreases the clasts in the debris flows pulverize the up-slope side of the trees and often imbed clasts in them. Debris flows in Rattlesnake Creek are relatively slow moving and commonly stop in the channel

  4. Faunal responses to fire in chaparral and sage scrub in California, USA

    USGS Publications Warehouse

    van Mantgem, Elizabeth; Keeley, Jon E.; Witter, Marti

    2015-01-01

    Impact of fire on California shrublands has been well studied but nearly all of this work has focused on plant communities. Impact on and recovery of the chaparral fauna has received only scattered attention; this paper synthesizes what is known in this regard for the diversity of animal taxa associated with California shrublands and outlines the primary differences between plant and animal responses to fire. We evaluated the primary faunal modes of resisting fire effects in three categories: 1) endogenous survival in a diapause or diapause-like stage, 2) sheltering in place within unburned refugia, or 3) fleeing and recolonizing. Utilizing these patterns in chaparral and sagescrub, as well as some studies on animals in other mediterranean-climate ecosystems, we derived generalizations about how plants and animals differ in their responses to fire impacts and their post fire recovery. One consequence of these differences is that variation in fire behavior has a much greater potential to affect animals than plants. For example, plants recover from fire endogenously from soil-stored seeds and resprouts, so fire size plays a limited role in determining recovery patterns. However, animals that depend on recolonization of burned sites from metapopulations may be greatly affected by fire size. Animal recolonization may also be greatly affected by regional land use patterns that affect colonization corridors, whereas such regional factors play a minimal role in plant community recovery. Fire characteristics such as rate of spread and fire intensity do not appear to play an important role in determining patterns of chaparral and sage scrub plant recovery after fire. However, these fire behavior characteristics may have a profound role in determining survivorship of some animal populations as slow-moving, smoldering combustion may limit survivorship of animals in burrows, whereas fast-moving, high intensity fires may affect survivorship of animals in above ground refugia or

  5. Contrasting rainfall generated debris flows from adjacent watersheds at Forest Falls, southern California, USA

    USGS Publications Warehouse

    Morton, D.M.; Alvarez, R.M.; Ruppert, K.R.; Goforth, B.

    2008-01-01

    Debris flows are widespread and common in many steeply sloping areas of southern California. The San Bernardino Mountains community of Forest Falls is probably subject to the most frequently documented debris flows in southern California. Debris flows at Forest Falls are generated during short-duration high-intensity rains that mobilize surface material. Except for debris flows on two consecutive days in November 1965, all the documented historic debris flows have occurred during high-intensity summer rainfall, locally referred to as 'monsoon' or 'cloudburst' rains. Velocities of the moving debris range from about 5??km/h to about 90??km/h. Velocity of a moving flow appears to be essentially a function of the water content of the flow. Low velocity debris flows are characterized by steep snouts that, when stopped, have only small amounts of water draining from the flow. In marked contrast are high-velocity debris flows whose deposits more resemble fluvial deposits. In the Forest Falls area two adjacent drainage basins, Snow Creek and Rattlesnake Creek, have considerably different histories of debris flows. Snow Creek basin, with an area about three times as large as Rattlesnake Creek basin, has a well developed debris flow channel with broad levees. Most of the debris flows in Snow Creek have greater water content and attain higher velocities than those of Rattlesnake Creek. Most debris flows are in relative equilibrium with the geometry of the channel morphology. Exceptionally high-velocity flows, however, overshoot the channel walls at particularly tight channel curves. After overshooting the channel, the flows degrade the adjacent levee surface and remove trees and structures in the immediate path, before spreading out with decreasing velocity. As the velocity decreases the clasts in the debris flows pulverize the up-slope side of the trees and often imbed clasts in them. Debris flows in Rattlesnake Creek are relatively slow moving and commonly stop in the

  6. Trends and causes of severity, size, and number of fires in northwestern California, USA.

    PubMed

    Miller, J D; Skinner, C N; Safford, H D; Knapp, E E; Ramirez, C M

    2012-01-01

    Research in the last several years has indicated that fire size and frequency are on the rise in western U.S. forests. Although fire size and frequency are important, they do not necessarily scale with ecosystem effects of fire, as different ecosystems have different ecological and evolutionary relationships with fire. Our study assessed trends and patterns in fire size and frequency from 1910 to 2008 (all fires > 40 ha), and the percentage of high-severity in fires from 1987 to 2008 (all fires > 400 ha) on the four national forests of northwestern California. During 1910-2008, mean and maximum fire size and total annual area burned increased, but we found no temporal trend in the percentage of high-severity fire during 1987-2008. The time series of severity data was strongly influenced by four years with region-wide lightning events that burned huge areas at primarily low-moderate severity. Regional fire rotation reached a high of 974 years in 1984 and fell to 95 years by 2008. The percentage of high-severity fire in conifer-dominated forests was generally higher in areas dominated by smaller-diameter trees than in areas with larger-diameter trees. For Douglas-fir forests, the percentage of high-severity fire did not differ significantly between areas that re-burned and areas that only burned once (10% vs. 9%) when re-burned within 30 years. Percentage of high-severity fire decreased to 5% when intervals between first and second fires were > 30 years. In contrast, in both mixed-conifer and fir/high-elevation conifer forests, the percentage of high-severity fire was less when re-burned within 30 years compared to first-time burned (12% vs. 16% for mixed conifer; 11% vs. 19% for fir/high-elevation conifer). Additionally, the percentage of high-severity fire did not differ whether the re-burn interval was less than or greater than 30 years. Years with larger fires and greatest area burned were produced by region-wide lightning events, and characterized by less winter

  7. Effects of trichloroethylene and perchloroethylene on wild rodents at Edwards Air Force Base, California, USA

    USGS Publications Warehouse

    Spring, Sarah E.; Miles, A. Keith; Anderson, Michael J.

    2004-01-01

    Effects of inhalation of volatilized trichloroethylene (TCE) or perchloroethylene (PCE) were assessed based on the health and population size of wild, burrowing mammals at Edwards Air Force Base (CA, USA). Organic soil-vapor concentrations were measured at three sites with aquifer contamination of TCE or PCE of 5.5 to 77 mg/L and at two uncontaminated reference sites. Population estimates of kangaroo rats (Dipodomys merriami and D. panamintinus) as well as hematology, blood chemistry, and histopathology of kangaroo rats and deer mice (Peromyscus maniculatus) were compared between contaminated and uncontaminated populations. Maximum soil-gas concentrations associated with groundwater contamination were less than 1.5 μl/L of TCE and 0.07 μl/L of PCE. Population estimates of kangaroo rats were similar at contaminated and reference sites. Hematology, blood chemistry, and histopathology of kangaroo rats and deer mice indicated no evidence of health effects caused by exposure. Trichloroethylene or PCE in groundwater and in related soil gas did not appear to reduce the size of small mammal populations or impair the health of individuals.

  8. Mercury concentrations and loads in a large river system tributary to San Francisco Bay, California, USA

    USGS Publications Warehouse

    David, N.; McKee, L.J.; Black, F.J.; Flegal, A.R.; Conaway, C.H.; Schoellhamer, D.H.; Ganju, N.K.

    2009-01-01

    In order to estimate total mercury (HgT) loads entering San Francisco Bay, USA, via the Sacramento-San Joaquin River system, unfiltered water samples were collected between January 2002 and January 2006 during high flow events and analyzed for HgT. Unfiltered HgT concentrations ranged from 3.2 to 75 ng/L and showed a strong correlation (r2 = 0.8, p < 0.001, n = 78) to suspended sediment concentrations (SSC). During infrequent large floods, HgT concentrations relative to SSC were approximately twice as high as observed during smaller floods. This difference indicates the transport of more Hg-contaminated particles during high discharge events. Daily HgT loads in the Sacramento-San Joaquin River at Mallard Island ranged from below the limit of detection to 35 kg. Annual HgT loads varied from 61 ?? 22 kg (n = 5) in water year (WY) 2002 to 470 ?? 170 kg (n = 25) in WY 2006. The data collected will assist in understanding the long-term recovery of San Francisco Bay from Hg contamination and in implementing the Hg total maximum daily load, the long-term cleanup plan for Hg in the Bay. ?? 2009 SETAC.

  9. Directly dated MIS 3 lake-level record from Lake Manix, Mojave Desert, California, USA

    USGS Publications Warehouse

    Reheis, Marith; Miller, David M.; McGeehin, John P.; Redwine, Joanna R.; Oviatt, Charles G.; Bright, Jordon E.

    2015-01-01

    An outcrop-based lake-level curve, constrained by ~ 70 calibrated 14C ages on Anodonta shells, indicates at least 8 highstands between 45 and 25 cal ka BP within 10 m of the 543-m upper threshold of Lake Manix in the Mojave Desert of southern California. Correlations of Manix highstands with ice, marine, and speleothem records suggest that at least the youngest three highstands coincide with Dansgaard–Oeschger (D–O) stadials and Heinrich events 3 and 4. The lake-level record is consistent with results from speleothem studies in the Southwest that indicate cool wet conditions during D–O stadials. Notably, highstands between 43 and 25 ka apparently occurred at times of generally low levels of pluvial lakes farther north as interpreted from core-based proxies. Mojave lakes may have been supported by tropical moisture sources during oxygen-isotope stage 3, perhaps controlled by southerly deflection of Pacific storm tracks due to weakening of the sea-surface temperature gradient in response to North Atlantic climate perturbations.

  10. Helium systematics of cold seep fluids at Monterey Bay, California, USA: Temporal variations and mantle contributions

    NASA Astrophysics Data System (ADS)

    Füri, E.; Hilton, D. R.; Brown, K. M.; Tryon, M. D.

    2009-08-01

    We report helium isotope ratios (3He/4He) as well as helium and neon abundance results for submarine cold seep fluids from Extrovert Cliff in Monterey Bay, California. Samples were collected in copper tubing attached to submarine flux meters operating in continuous pumping mode. Following instrumentation recovery, the tubing was sectioned to produce for the first time a high-resolution time series of dissolved He and Ne variations over a time span of several days. Noble gas concentrations are variable and appear affected by interaction with a hydrocarbon phase within the aquifer. However, it is still possible to resolve the He signal into components associated with air equilibration, excess air entrainment, and terrigenic fluxes (both crustal and mantle-derived). The mantle He contribution reaches ˜25-30% in some samples (up to 2.3 RA, where RA = air 3He/4He). Our quasi-continuous He-Ne record shows remarkable fluctuations over time scales of only a few hours and reflects the combined effects of gas stripping by hydrocarbons and an episodic input of mantle-derived fluids.

  11. Geochronology and paleoenvironment of pluvial Harper Lake, Mojave Desert, California, USA

    NASA Astrophysics Data System (ADS)

    Garcia, Anna L.; Knott, Jeffrey R.; Mahan, Shannon A.; Bright, Jordon

    2014-03-01

    Accurate reconstruction of the paleo-Mojave River and pluvial lake (Harper, Manix, Cronese, and Mojave) system of southern California is critical to understanding paleoclimate and the North American polar jet stream position over the last 500 ka. Previous studies inferred a polar jet stream south of 35°N at 18 ka and at ~ 40°N at 17-14 ka. Highstand sediments of Harper Lake, the upstream-most pluvial lake along the Mojave River, have yielded uncalibrated radiocarbon ages ranging from 24,000 to > 30,000 14C yr BP. Based on geologic mapping, radiocarbon and optically stimulated luminescence dating, we infer a ~ 45-40 ka age for the Harper Lake highstand sediments. Combining the Harper Lake highstand with other Great Basin pluvial lake/spring and marine climate records, we infer that the North American polar jet stream was south of 35°N about 45-40 ka, but shifted to 40°N by ~ 35 ka. Ostracodes (Limnocythere ceriotuberosa) from Harper Lake highstand sediments are consistent with an alkaline lake environment that received seasonal inflow from the Mojave River, thus confirming the lake was fed by the Mojave River. The ~ 45-40 ka highstand at Harper Lake coincides with a shallowing interval at downstream Lake Manix.

  12. Anomalous shear wave attenuation in the shallow crust beneath the Coso volcanic regionn, California ( USA).

    USGS Publications Warehouse

    Sanders, C.; Ho-Liu, P.; Rinn, D.; Hiroo, Kanamori

    1988-01-01

    We use seismograms of local earthquakes to image relative shear wave attenuation structure in the shallow crust beneath the region containing the Coso volcanic-geothermal area of E California. Seismograms of 16 small earthquakes show SV amplitudes which are greatly diminished at some azimuths and takeoff angles, indicating strong lateral variations in S wave attenuation in the area. 3-D images of the relative S wave attenuation structure are obtained from forward modeling and a back projection inversion of the amplitude data. The results indicate regions within a 20 by 30 by 10 km volume of the shallow crust (one shallower than 5 km) that severely attenuate SV waves passing through them. These anomalies lie beneath the Indian Wells Valley, 30 km S of the Coso volcanic field, and are coincident with the epicentral locations of recent earthquake swarms. No anomalous attenuation is seen beneath the Coso volcanic field above about 5 km depth. Geologic relations and the coincidence of anomalously slow P wave velocities suggest that the attenuation anomalies may be related to magmatism along the E Sierra front.-from Authors

  13. Human viruses and viral indicators in marine water at two recreational beaches in Southern California, USA.

    PubMed

    Love, David C; Rodriguez, Roberto A; Gibbons, Christopher D; Griffith, John F; Yu, Qilu; Stewart, Jill R; Sobsey, Mark D

    2014-03-01

    Waterborne enteric viruses may pose disease risks to bather health but occurrence of these viruses has been difficult to characterize at recreational beaches. The aim of this study was to evaluate water for human virus occurrence at two Southern California recreational beaches with a history of beach closures. Human enteric viruses (adenovirus and norovirus) and viral indicators (F+ and somatic coliphages) were measured in water samples over a 4-month period from Avalon Beach, Catalina Island (n = 324) and Doheny Beach, Orange County (n = 112). Human viruses were concentrated from 40 L samples and detected by nested reverse transcriptase polymerase chain reaction (PCR). Detection frequencies at Doheny Beach were 25.5% (adenovirus) and 22.3% (norovirus), and at Avalon Beach were 9.3% (adenovirus) and 0.7% (norovirus). Positive associations between adenoviruses and fecal coliforms were observed at Doheny (p = 0.02) and Avalon (p = 0.01) Beaches. Human viruses were present at both beaches at higher frequencies than previously detected in the region, suggesting that the virus detection methods presented here may better measure potential health risks to bathers. These virus recovery, concentration, and molecular detection methods are advancing practices so that analysis of enteric viruses can become more effective and routine for recreational water quality monitoring.

  14. Diets of three species of anurans from the cache creek watershed, California, USA

    USGS Publications Warehouse

    Hothem, R.L.; Meckstroth, A.M.; Wegner, K.E.; Jennings, M.R.; Crayon, J.J.

    2009-01-01

    We evaluated the diets of three sympatric anuran species, the native Northern Pacific Treefrog, Pseudacris regilla, and Foothill Yellow-Legged Frog, Rana boylii, and the introduced American Bullfrog, Lithobates catesbeianus, based on stomach contents of frogs collected at 36 sites in 1997 and 1998. This investigation was part of a study of mercury bioaccumulation in the biota of the Cache Creek Watershed in north-central California, an area affected by mercury contamination from natural sources and abandoned mercury mines. We collected R. boylii at 22 sites, L. catesbeianus at 21 sites, and P. regilla at 13 sites. We collected both L. catesbeianus and R. boylii at nine sites and all three species at five sites. Pseudacris regilla had the least aquatic diet (100% of the samples had terrestrial prey vs. 5% with aquatic prey), followed by R. boylii (98% terrestrial, 28% aquatic), and L. catesbeianus, which had similar percentages of terrestrial (81%) and aquatic prey (74%). Observed predation by L. catesbeianus on R. boylii may indicate that interaction between these two species is significant. Based on their widespread abundance and their preference for aquatic foods, we suggest that, where present, L. catesbeianus should be the species of choice for all lethal biomonitoring of mercury in amphibians. Copyright ?? 2009 Society for the Study of Amphibians and Reptiles.

  15. Attributes of desert tortoise populations at the National Training Center, Central Mojave Desert, California, USA

    USGS Publications Warehouse

    Berry, K.H.; Bailey, T.Y.; Anderson, K.M.

    2006-01-01

    We sampled 21 study plots for desert tortoises (Gopherus agassizii) at the National Training Center, Fort Irwin, California. Each plot was sampled once between 1997 and 2003 to obtain a snapshot of population attributes, status, and relationships between tortoise densities and human activities. Densities ranged from <1 to 28 tortoises km-2; overall, tortoises were uncommon to rare at 16 of the 21 plots. Tortoise densities were negatively correlated with death rates, infectious disease (mycoplasmosis), surface disturbance and trash. Health status of tortoises was correlated with some anthropogenic uses. The presence of infectious disease in tortoises was negatively correlated with distances from offices, the Ft. Irwin cantonment, and paved roads. Also, significantly more tortoises with shell disease were found on plots with current and recent military use than on plots with no history of military use. Factors contributing to or causing deaths of tortoises included vehicles, vandalism, predation, mycoplasmosis and shell diseases. Annual death rates for subadult and adult tortoises ranged from 1.9% to 95.2% for the 4 years preceding surveys. Deaths from anthropogenic sources were significantly correlated with surface disturbances, trash, military ordnance, and proximity to offices and paved roads-typical characteristics of military training areas.

  16. Chemical contaminants in gray whales (eschichtius robustus) stranded in Alaska, Washington, and California, USA. Technical memo

    SciTech Connect

    Varanasi, U.; Stein, J.E.; Tilbury, K.L.; Meador, J.P.; Sloan, C.A.

    1993-08-01

    The concentrations of chlorinated hydrocarbons (CHs) such as polychlorinated biphenyls (PCBs), 1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethanes (DDTs), 1,1-dichloro-2,2-bis(p- chlorophenyl) ethenes (DDEs), and chlordanes, and essential (e.g., zinc, selenium, copper) and toxic (e.g., mercury, lead) elements were measured in tissues and stomach contents from 22 gray whales (Eschrichtius robustus) stranded between 1988 and 1991. The stranding sites ranged from the relatively pristine areas of Kodiak Island, Alaska, to more urbanized areas in Puget Sound, Washington, and San Francisco Bay, California, with the majority of the sites on the Washington outer coast and in Puget Sound. Similar to concentrations in tissues, no significant differences were observed in concentrations of elements in stomach contents between whales stranded in Puget Sound and whales stranded at the more pristine sites. The lack of data from apparently healthy gray whales limits the assessment of whether the levels of anthropogenic contaminants found in tissues may have deleterious effects on the health of gray whales.

  17. Comparing volunteer and professionally collected monitoring data from the rocky subtidal reefs of Southern California, USA.

    PubMed

    Gillett, David J; Pondella, Daniel J; Freiwald, Jan; Schiff, Kenneth C; Caselle, Jennifer E; Shuman, Craig; Weisberg, Stephen B

    2012-05-01

    Volunteer-based citizen monitoring has increasingly become part of the natural resources monitoring framework, but it is often unclear whether the data quality from these programs is sufficient for integration with traditional efforts conducted by professional scientists. At present, the biological and physical characteristics of California's rocky reef kelp forests are concurrently monitored by two such groups, using similar methodologies--underwater visual census (UVC) of fish, benthic invertebrates, and reef habitat, though the volunteer group limits their sampling to transects close to the reef surface and they use a more constrained list of species for enumeration and measurement. Here, we compared the data collected from 13 reefs that were sampled by both programs in 2008. These groups described relatively similar fish communities, total fish abundance and abundance of the dominant fish species but there were some differences in the measured size distributions of the dominant fish species. Descriptions of the benthic invertebrate community were also similar, though there were some differences in relative abundance that may have resulted from the less detailed subsampling protocols used by the volunteers. The biggest difference was in characterization of the physical habitat of the reefs, which appeared to result from selection bias of transect path by the volunteer program towards more complex structured sections of a reef. Changes to address these differences are relatively simple to implement and if so, offer the promise of better integration of the trained volunteer monitoring with that of professional monitoring groups.

  18. Geochronology and paleoenvironment of pluvial Harper Lake, Mojave Desert, California, USA

    USGS Publications Warehouse

    Garcia, Anna L.; Knott, Jeffrey R.; Mahan, Shannon; Bright, Jordan

    2014-01-01

    Accurate reconstruction of the paleo-Mojave River and pluvial lake (Harper, Manix, Cronese, and Mojave) system of southern California is critical to understanding paleoclimate and the North American polar jet stream position over the last 500 ka. Previous studies inferred a polar jet stream south of 35°N at 18 ka and at ~ 40°N at 17–14 ka. Highstand sediments of Harper Lake, the upstream-most pluvial lake along the Mojave River, have yielded uncalibrated radiocarbon ages ranging from 24,000 to > 30,000 14C yr BP. Based on geologic mapping, radiocarbon and optically stimulated luminescence dating, we infer a ~ 45–40 ka age for the Harper Lake highstand sediments. Combining the Harper Lake highstand with other Great Basin pluvial lake/spring and marine climate records, we infer that the North American polar jet stream was south of 35°N about 45–40 ka, but shifted to 40°N by ~ 35 ka. Ostracodes (Limnocythere ceriotuberosa) from Harper Lake highstand sediments are consistent with an alkaline lake environment that received seasonal inflow from the Mojave River, thus confirming the lake was fed by the Mojave River. The ~ 45–40 ka highstand at Harper Lake coincides with a shallowing interval at downstream Lake Manix.

  19. Isotopic constraints on sources of methane in Los Angeles, California, USA (Invited)

    NASA Astrophysics Data System (ADS)

    Townsend-Small, A.; Tyler, S. C.; Christensen, L.; Xu, X.; Pataki, D. E.

    2009-12-01

    Methane is a powerful greenhouse gas and an important contributor to global warming. Recent studies have suggested that methane emissions in large cities are underestimated with several models even indicating that substantial emissions attributed to cities are in part from regional and/or encroaching agricultural sources rather than from urban fossil fuel sources. We have found that stable isotopes (13-C and D) and radiocarbon (C-14) are excellent tracers of various sources of methane in Los Angeles, California. Measurements of the d13C and dD of methane from discrete sources show excellent separation between urban sources, such as vehicle emissions, power plants, oil refineries, landfills, and sewage treatment plants and agricultural sources like cows, biogas, and cattle feedlots. In addition, radiocarbon is an excellent tracer of modern versus fossil fuel contributions to methane emissions in the region. Preliminary measurements of background air in Los Angeles indicate that the major source of excess methane is vehicle emissions with most additional CH4 likely contributed from among other fossil fuel sources such as oil refining or power plants. We are currently confirming these results with broader field campaigns and additional measurements, including continuous measurements of atmospheric methane concentration using tunable laser spectroscopy. The combination of high-resolution tunable laser concentration measurements and precise isotope measurements using mass spectrometry is a very promising and powerful tool for methane source monitoring.

  20. Soda Lake-Painted Rock(!) Petroleum System in the Cuyama Basin, California, U.S.A.

    USGS Publications Warehouse

    Lillis, Paul G.

    1994-01-01

    The Cuyama basin, located in the central California Coast Ranges, was formed by extension during early Miocene time and was filled with a variety of nonmarine, marginal marine, and neritic to bathyal marine sediments. Low sulfur oil is produced primarily from the lower Miocene Painted Rock Sandstone Member of the Vaqueros Formation along a structural trend parallel to the Russell fault, which was active from 23 to 5 Ma. A major fold and thrust belt beginning about 3 Ma formed the Caliente and Sierra Madre ranges and partially obscures the Miocene extensional basin. Stable carbon isotope and biomarker data indicate that the lower Miocene Soda Lake Shale Member of the Vaqueros Formation is the predominant source rock for the oil in the Cuyama area. Burial and thermal history modeling shows that oil generation began in middle-late Miocene time and that oil migrated into existing traps. Younger traps that formed in the overthrust are barren of oil because migration occurred prior to the development of the fold and thrust belt or because subthrust oil was unable to migrate into the overthrust.

  1. Determinants of Multidrug-Resistant Tuberculosis Clusters, California, USA, 2004–2007

    PubMed Central

    Kim, Elizabeth Y.; Lin, S.-Y. Grace; Cattamanchi, Adithya; Oh, Peter; Flood, Jennifer; Hopewell, Philip C.; Kato-Maeda, Midori

    2010-01-01

    Laboratory and epidemiologic evidence suggests that pathogen-specific factors may affect multidrug-resistant (MDR) tuberculosis (TB) transmission and pathogenesis. To identify demographic and clinical characteristics of MDR TB case clustering and to estimate the effect of specific isoniazid resistance–conferring mutations and strain lineage on genotypic clustering, we conducted a population-based cohort study of all MDR TB cases reported in California from January 1, 2004, through December 31, 2007. Of 8,899 incident culture-positive cases for which drug susceptibility information was available, 141 (2%) were MDR. Of 123 (87%) strains with genotype data, 25 (20%) were aggregated in 8 clusters; 113 (92%) of all MDR TB cases and 21 (84%) of clustered MDR TB cases occurred among foreign-born patients. In multivariate analysis, the katG S315T mutation (odds ratio 11.2, 95% confidence interval 2.2–∞; p = 0.004), but not strain lineage, was independently associated with case clustering. PMID:20735924

  2. Neogene folding and faulting in southern Monterey Bay, Central California, USA

    USGS Publications Warehouse

    Gardner-Taggart, J. M.; Greene, H. Gary; Ledbetter, M.T.

    1993-01-01

    The goal of this study was to determine the Neogene structural history of southern Monterey Bay by mapping and correlating the shallow tectonic structures with previously identified deeper occurring structures. Side scan sonographs and Uniboom seismic reflection profiles collected in the region suggest that deformation associated with both compressional and transcurrent movement is occurring. Strike-slip movement between the North American and Pacific plates started as subduction ceased 21 Ma, creating the San Andreas fault system. Clockwise rotation of the Pacific plate occurred between 3.4 and 3.9 Ma causing orthogonal convergence between the two plates. This plate rotation is responsible for compressional Neogene structures along the central California coast. Structures exhibit transpressional tectonic characteristics such as thrust faulting, reverse faulting and asymmetrical folding. Folding and faulting are confined to middle Miocene and younger strata. Shallow Mesozoic granitic basement rocks either crop out or lie near the surface in most of the region and form a possible de??collement along which the Miocene Monterey Formation has decoupled and been folded. Over 50% of the shallow faults strike normal (NE-SW) to the previously identified faults. Wrench fault tectonics complicated by compression, gradual uplift of the basement rocks, and a change in plate convergence direction are responsible for the observed structures in southern Monterey Bay. ?? 1993.

  3. Re-evaluating the origins of late Pleistocene fire areas on Santa Rosa Island, California, USA

    NASA Astrophysics Data System (ADS)

    Rick, Torben C.; Wah, John S.; Erlandson, Jon M.

    2012-09-01

    At the close of the Pleistocene, fire regimes in North America changed significantly in response to climate change, megafaunal extinctions, anthropogenic burning and, possibly, even an extraterrestrial impact. On California's Channel Islands, researchers have long debated the nature of late Pleistocene "fire areas," discrete red zones in sedimentary deposits, interpreted by some as prehistoric mammoth-roasting pits created by humans. Further research found no evidence that these red zones were cultural in origin, and two hypotheses were advanced to explain their origin: natural fires and groundwater processes. Radiocarbon dating, X-ray diffraction analysis, and identification of charcoal from six red zones on Santa Rosa Island suggest that the studied features date between ~ 27,500 and 11,400 cal yr BP and resulted from burning or heating, not from groundwater processes. Our results show that fire was a component of late Pleistocene Channel Island ecology prior to and after human colonization of the islands, with no clear evidence for increased fire frequency coincident with Paleoindian settlement, extinction of pygmy mammoths, or a proposed Younger Dryas impact event.

  4. Are the benches at Mormon Point, Death Valley, California, USA, scarps or strandlines?

    USGS Publications Warehouse

    Knott, J.R.; Tinsley, J. C.; Wells, S.G.

    2002-01-01

    The benches and risers at Mormon Point, Death Valley, USA, have long been interpreted as strandlines cut by still-stands of pluvial lakes correlative with oxygen isotope stage (OIS) 5e/6 (120,000-186,000 yr B.P.) and OIS-2 (10,000-35,000 yr B.P.). This study presents geologic mapping and geomorphic analyses (Gilbert's criteria, longitudinal profiles), which indicate that only the highest bench at Mormon Point (~90 m above mean sea level (msl)) is a lake strandline. The other prominent benches on the north-descending slope immediately below this strandline are interpreted as fault scarps offsetting a lacustrine abrasion platform. The faults offsetting the abrasion platform most likely join downward into and slip sympathetically with the Mormon Point turtleback fault, implying late Quaternary slip on this low-angle normal fault. Our geomorphic reinterpretation implies that the OIS-5e/6 lake receded rapidly enough not to cut strandlines and was ~90 m deep. Consistent with independent core studies of the salt pan, no evidence of OIS-2 lake strandlines was found at Mormon Point, which indicates that the maximum elevation of the OIS-2 lake surface was -30 m msl. Thus, as measured by pluvial lake depth, the OIS-2 effective precipitation was significantly less than during OIS-5e/6, a finding that is more consistent with other studies in the region. The changed geomorphic context indicates that previous surface exposure dates on fault scarps and benches at Mormon Point are uninterpretable with respect to lake history. ?? 2002 University of Washington.

  5. Modeling selenium bioaccumulation through arthropod food webs in San Francisco Bay, California, USA

    USGS Publications Warehouse

    Schlekat, C.E.; Purkerson, D.G.; Luoma, S.N.

    2004-01-01

    Trophic transfer is the main process by which upper trophic level wildlife are exposed to selenium. Transfers through lower levels of a predator's food web thus can be instrumental in determining the threat of selenium in an ecosystem. Little is known about Se transfer through pelagic, zooplankton-based food webs in San Francisco Bay ([SFB], CA, USA), which serve as an energy source for important predators such as striped bass. A dynamic multipathway bioaccumulation model was used to model Se transfer from phytoplankton to pelagic copepods to carnivorous mysids (Neomysis mercedis). Uptake rates of dissolved Se, depuration rates, and assimilation efficiencies (AE) for the model were determined for copepods and mysids in the laboratory. Small (73-250 ??m) and large (250-500 ??m) herbivorous zooplankton collected from SFB (Oithona/Limnoithona and Acartia sp.) assimilated Se with similar efficiencies (41-52%) from phytoplankton. Mysids assimilated 73% of Se from small herbivorous zooplankton; Se AE was significantly lower (61%) than larger herbivorous zooplankton. Selenium depuration rates were high for both zooplankton and mysids (12-25% d-1), especially compared to bivalves (2-3% d-1). The model predicted steady state Se concentrations in mysids similar to those observed in the field. The predicted concentration range (1.5-5.4 ??g g -1) was lower than concentrations of 4.5 to 24 ??g g-1 observed in bivalves from the bay. Differences in efflux between mysids and bivalves were the best explanation for the differences in uptake. The results suggest that the risk of selenium toxicity to predators feeding on N. mercedis would be less than the risk to predators feeding on bivalves. Management of selenium contamination should include food webs analyses to focus on the most important exposure pathways identified for a given watershed.

  6. Climate, lightning ignitions, and fire severity in Yosemite National Park, California, USA

    USGS Publications Warehouse

    Lutz, J.A.; van Wagtendonk, J.W.; Thode, A.E.; Miller, J.D.; Franklin, J.F.

    2009-01-01

    Continental-scale studies of western North America have attributed recent increases in annual area burned and fire size to a warming climate, but these studies have focussed on large fires and have left the issues of fire severity and ignition frequency unaddressed. Lightning ignitions, any of which could burn a large area given appropriate conditions for fire spread, could be the first indication of more frequent fire. We examined the relationship between snowpack and the ignition and size of fires that occurred in Yosemite National Park, California (area 3027 km2), between 1984 and 2005. During this period, 1870 fires burned 77 718 ha. Decreased spring snowpack exponentially increased the number of lightning-ignited fires. Snowpack mediated lightning-ignited fires by decreasing the proportion of lightning strikes that caused lightning-ignited fires and through fewer lightning strikes in years with deep snowpack. We also quantified fire severity for the 103 fires >40 ha with satellite fire-severity indices using 23 years of Landsat Thematic Mapper data. The proportion of the landscape that burned at higher severities and the complexity of higher-severity burn patches increased with the log10 of annual area burned. Using one snowpack forecast, we project that the number of lightning-ignited fires will increase 19.1% by 2020 to 2049 and the annual area burned at high severity will increase 21.9%. Climate-induced decreases in snowpack and the concomitant increase in fire severity suggest that existing assumptions may be understated-fires may become more frequent and more severe. ?? IAWF 2009.

  7. Concordant paleolatitudes from ophiolite sequences in the northern California Coast Ranges, U.S.A.

    USGS Publications Warehouse

    Mankinen, E.A.; Gromme, C.S.; Williams, K.M.

    1991-01-01

    Paleomagnetic data have been obtained from two ophiolite sequences in the northern California Coast Ranges: from Mount Diablo in the San Francisco Bay area and from Potter Valley, north of Clear Lake. The ophiolite exposed at Mount Diablo is part of the late Middle to Late Jurassic Coast Range ophiolite, and that exposed near Potter Valley is Late Jurassic to perhaps Early Cretaceous in age and occurs within the Franciscan assemblage. Data from the sheeted-dike complex at Mount Diablo show these rocks to be strongly overprinted, probably following uplift and erosion of the ophiolite. Samples whose primary remanent magnetization seems to be recovered yield a mean paleomagnetic pole at 30.7??N, 159.5??E with ??95 = 5.6??. A comparison of this pole with the Jurassic apparent polar wander path for North America indicates that the ophiolite has rotated 45?? ?? 7?? counterclockwise relative to the craton and has not been latitudinally displaced. The diabase and pillow basalt in Potter Valley have not been strongly overprinted and data from those rocks yield a paleomagnetic pole at 79.0??N, 61.5??E with ??95 = 6.4??. This result indicates that the ophiolite at Potter Valley has rotated approximately 29?? ?? 8?? clockwise, and has undergone little or no latitudinal displacement. Because of the predominantly northeastward transport of oceanic plates converging with the western margin of North America since middle Mesozoic time, the absence of appreciable northward displacement of either ophiolite fragment indicates that both formed close to the continental margin. ?? 1991.

  8. Earthquake Interactions at Different Scales: an Example from Eastern California and Western Nevada, USA.

    NASA Astrophysics Data System (ADS)

    Verdecchia, A.; Carena, S.

    2015-12-01

    Earthquakes in diffuse plate boundaries occur in spatially and temporally complex patterns. The region east of the Sierra Nevada that encompasses the northern Eastern California Shear Zone (ECSZ), Walker Lane (WL), and the westernmost part of the Basin and Range province (B&R) is such a kind of plate boundary. In order to better understand the relationship between moderate-to major earthquakes in this area, we modeled the evolution of coseismic, postseismic and interseismic Coulomb stress changes (∆CFS) in this region at two different spatio-temporal scales. In the first example we examined seven historical and instrumental Mw ≥ 6 earthquakes that struck the region around Owens Valley (northern ECSZ) in the last 150 years. In the second example we expanded our study area to all of the northern ECSZ, WL and western B&R, examining seventeen paleoseismological and historical major surface-rupturing earthquakes (Mw ≥ 6.5) that occurred in the last 1400 years. We show that in both cases the majority of the studied events (100% in the first case and 80% in the second) are located in areas of combined coseismic and postseismic positive ∆CFS. This relationship is robust, as shown by control tests with random earthquake sequences. We also show that the White Mountain fault has accumulated up to 30 bars of total ∆CFS (coseismic + postseismic + interseismic) in the last 150 years, and the Hunter Mountain, Fish Lake Valley, Black Mountain, and Pyramid Lake faults have accumulated 40, 45, 54 and 37 bars respectively in the last 1400 years. Such values are comparable to the average stress drop in a major earthquake, and all these faults may be therefore close to failure.

  9. An alkaline spring system within the Del Puerto ophiolite (California USA): A Mars analog site

    SciTech Connect

    Blank, J.G.; Green, S.; Blake, D.; Valley, J.; Kita, N.; Treiman, A.; Dobson, P.F.

    2008-10-01

    Mars appears to have experienced little compositional differentiation of primitive lithosphere, and thus much of the surface of Mars is covered by mafic lavas. On Earth, mafic and ultramafic rocks present in ophiolites, oceanic crust and upper mantle that have been obducted onto land, are therefore good analogs for Mars. The characteristic mineralogy, aqueous geochemistry, and microbial communities of cold-water alkaline springs associated with these mafic and ultramafic rocks represent a particularly compelling analog for potential life-bearing systems. Serpentinization, the reaction of water with mafic minerals such as olivine and pyroxene, yields fluids with unusual chemistry (Mg-OH and Ca-OH waters with pH values up to {approx}12), as well as heat and hydrogen gas that can sustain subsurface, chemosynthetic ecosystems. The recent observation of seeps from pole-facing crater and canyon walls in the higher Martian latitudes supports the hypothesis that even present conditions might allow for a rockhosted chemosynthetic biosphere in near-surface regions of the Martian crust. The generation of methane within a zone of active serpentinization, through either abiogenic or biogenic processes, could account for the presence of methane detected in the Martian atmosphere. For all of these reasons, studies of terrestrial alkaline springs associated with mafic and ultramafic rocks are particularly timely. This study focuses on the alkaline Adobe Springs, emanating from mafic and ultramafic rocks of the California Coast Range, where a community of novel bacteria is associated with the precipitation of Mg-Ca carbonate cements. The carbonates may serve as a biosignature that could be used in the search for evidence of life on Mars.

  10. Greenhouse gas emissions from alternative water supply processes in southern California, USA

    NASA Astrophysics Data System (ADS)

    Schneider, A.; Townsend-Small, A.

    2012-12-01

    Burgeoning population centers and declining hydrological resources have encouraged the development of alternative water treatment systems, including desalination and wastewater recycling. These processes currently provide potable water for millions of people and assist in satisfying agricultural and landscaping irrigation demands. There are a variety of alternative water production methods in place, and while they help to reduce the demands placed on aquifers, during their operation they are also significant sources of greenhouse gases. The environmental advantages of these alternative water production methods need to be carefully weighed against their energy footprints and greenhouse gas emissions profiles. This study measured the greenhouse gas emissions of a wastewater treatment and recycling facility in Orange County, California to get a more complete picture of the carbon footprint of the plant. We measured atmospheric emissions of CO2, CH4, and N2O throughout the water recycling process and at various times of the day and week. This allowed us to assemble a thorough, cross-sectional profile of greenhouse gas emissions from the facility. We then compared the measured emissions of the treatment plant to the modeled emissions of desalination plants in order to assess the relative carbon footprints of the two water production methods. Other water supply alternatives, including regional water importation, were also included in the comparison in order to provide a more complete understanding of the potential greenhouse gas emissions. Finally, we assessed the significance of wastewater treatment as an urban greenhouse gas source when compared to other known emissions in the region. This research offers a valuable tool for sustainable urban and regional development by providing planners with a quantified comparison of the carbon footprints of several water production options.

  11. Characterizing urbanization, and agricultural and conservation land-use change in Riverside County, California, USA.

    PubMed

    Chen, Xiongwen; Li, Bai-Lian; Allen, Michael F

    2010-05-01

    Monitoring trends in urbanization and land use related to population growth and changing social and economic conditions is an important tool for developing in land use and habitat conservation policy. We analyzed urbanization and agricultural land-use change in Riverside County, California from 1984 to 2002, comparing maps every two years on the basis of aerial photographs. Matrix analysis combined with information theory was applied to study land type conversion. Results showed that the total area of "Urban and Built-Up Land" increased the most whereas total area of "Prime Farmland" decreased most. Land-use characterized as "Grazing Land,"Farmland of Local Importance," and "Farmland of Statewide Importance" also decreased. Mean patch size also decreased for "Grazing Land,"Water Area,"Other Land," and "Prime Farmland." The diversity of land types decreased dramatically after 1992. Urbanization patterns were different among three city groups (Riverside City, Coachella Valley, and Blythe), indicating the different times for "leapfrog" development in the three areas. Furthermore, the unpredictability and change in composition of land use increased after 1996 due to intensified urbanization. If the current driving forces continue, our model projects that in 2020 the area of "Urban and Built-Up Land" may increase between 25% and 39% in comparison with 2002. Percentages of most agricultural land types are projected to decrease, especially "Farmland of Local Importance,"Prime Farmland," and "Farmland of Statewide Importance." If the county's goal is to preserve agricultural lands and natural biodiversity, while maintaining sustainable development, current land-use policies and practices should be changed. This study demonstrates new useful methods for monitoring and detection of change of land-use processes.

  12. Metabolic Potential and Activity in Fluids of the Coast Range Ophiolite Microbial Observatory, California, USA

    NASA Technical Reports Server (NTRS)

    Hoehler, T.; Som, S.; Schrenk, M.; McCollom, T.; Cardace, D.

    2016-01-01

    Metabolic potential and activity associated with hydrogen and carbon monoxide were characterized in fluids sampled from the the Coast Range Ophiolite Microbial Observatory (CROMO). CROMO consists of two clusters of science-dedicated wells drilled to varying depths up to 35m in the actively serpentinizing, Jurassic-age Coast Range Ophiolite of Northern California, along with a suite of pre-existing monitoring wells at the same site. Consistent with the fluid chemistry observed in other serpentinizing systems, CROMO fluids are highly alkaline, with pH up to 12.5, high in methane, with concentrations up 1600 micromolar, and low in dissolved inorganic carbon (DIC), with concentrations of 10's to 100's of micromolar. CROMO is conspicuous for fluid H2 concentrations that are consistently sub-micromolar, orders of magnitude lower than is typical of other systems. However, higher H2 concentrations (10's -100's of micromolar) at an earlier stage of fluid chemical evolution are predicted by, or consistent with: thermodynamic models for fluid chemistry based on parent rock composition equivalent to local peridotite and with water:rock ratio constrained by observed pH; the presence of magnetite at several wt% in CROMO drill cores; and concentrations of formate and carbon monoxide that would require elevated H2 if formed in equilibrium with H2 and DIC. Calculated Gibbs energy changes for reaction of H2 and CO in each of several metabolisms, across the range of fluid composition encompassed by the CROMO wells, range from bioenergetically feasible (capable of driving ATP synthesis) to thermodynamically unfavorable. Active consumption relative to killed controls was observed for both CO and H2 during incubation of fluids from the pre-existing monitoring wells; in incubations of freshly cored solids, consumption was only observed in one sample set (corresponding to the lowest pH) out of three. The specific metabolisms by which H2 and CO are consumed remain to be determined.

  13. Latest Pliocene and Quaternary diatom floras of the Lake Tahoe basin, California and Nevada, USA

    NASA Astrophysics Data System (ADS)

    Starratt, S. W.

    2005-12-01

    Despite an active research program at Lake Tahoe, few attempts have been made to understand the conditions that existed within the watershed prior to European contact. A greater understanding of the Quaternary history of the basin would not only benefit local stakeholders, but would also enhance the knowledge of the entire Truckee River system. Lake Tahoe has been called one of the most oligotrophic lakes in the world. Historically, the lake has contained low levels of phosphorus (5 g/L) and nitrogen (100 g/L). As a result, the abundance of phytoplankton and zooplankton is also low. Over the past century anthropogenic inputs have caused parts of the lake to become seasonally mesotrophic. The impact of climate variability on the nutrient load in the lake is poorly known. Detailed analysis of the pre-European contact record is necessary in order to unravel the complex interaction between natural and human inputs to the watershed. Dredge samples collected from slump blocks and surface sediments in the deep basin and surface samples collected at a number of sites around the margin of Lake Tahoe have been analyzed for diatoms and chrysophyte stomatocysts. The deep lake basin diatom flora is dominated by planktonic, oligotrophic, alkaliphilic taxa such as Cyclotella bodanica and C. ocellata. Planktonic and obligate planktonic taxa ( Aulacoseira distans, Fragilaria crotonensis, Stephanodiscus spp.) found close to shore and benthic taxa are representative of oligotrophic to eutrophic conditions ( Frustulia rhomboides, Tetracyclus glans, Achnanthes minutissima, Epithemia spp., Rhopalodia gibba, Meridion circulare). Several samples of diatomaceous sediment collected near Tahoe City, California, on the west side of the lake, contain taxa that are representative of shallow, more eutrophic conditions and at least one of these samples contains late Pliocene taxa ( Tertiarius sp., Pliocaenicus sp.), which suggests that at least locally, the lake at that time was shallower and was

  14. Last glacial maximum and Holocene lake levels of Owens Lake, eastern California, USA

    USGS Publications Warehouse

    Bacon, S.N.; Burke, R.M.; Pezzopane, S.K.; Jayko, A.S.

    2006-01-01

    Stratigraphic investigations of fluvio-deltaic and lacustrine sediments exposed in stream cuts, quarry walls, and deep trenches east of the Sierra Nevada in Owens Valley near Lone Pine, California have enabled the reconstruction of pluvial Owens Lake level oscillations. Age control for these sediments is from 22 radiocarbon (14C) dates and the identification and stratigraphic correlation of a tephra, which when plotted as a function of age versus altitude, define numerous oscillations in the level of pluvial Owens Lake during the latest Pleistocene and early Holocene. We have constructed a lake-level altitude curve for the time interval ???27,000 cal yr BP to present that is based on the integration of this new stratigraphic analysis with published surface stratigraphic data and subsurface core data. Pluvial Owens Lake regressed from its latest Pleistocene highstands from ???27,000 to ???15,300 cal yr BP, as recorded by ???15 m of down cutting of the sill from the altitudes of ???1160 to 1145 m. By ???11,600 cal yr BP, the lake had dropped ???45 m from the 1145 m sill. This lowstand was followed by an early Holocene transgression that attained a highstand near 1135 m before dropping to 1120 m at 7860-7650 cal yr BP that had not been recognized in earlier studies. The lake then lowered another ???30 m to shallow and near desiccation levels between ???6850 and 4300 cal yr BP. Fluvial cut-and-fill relations north of Lone Pine and well-preserved shoreline features at ???1108 m indicate a minor lake-level rise after 4300 cal yr BP, followed by alkaline and shallow conditions during the latest Holocene. The new latest Quaternary lake-level record of pluvial Owens Lake offers insight to the hydrologic balance along the east side of the southern Sierra Nevada and will assist regional paleoclimatic models for the western Basin and Range. ?? 2005 Elsevier Ltd. All rights reserved.

  15. Mineralization of organogenic ammonium in the Monterey Formation, Santa Maria and San Joaquin basins, California, USA

    SciTech Connect

    Compton, J.S. ); Williams, L.B.; Ferrell, R.E. Jr. )

    1992-05-01

    Inorganic fixed-ammonium (Amm) contents as high as 0.28 wt% were measured in organic-rich, quartz-grade siliceous rocks of the Miocene Monterey Formation from the Santa Maria and San Joaquin basins, California. The greatest amount of fixed-Amm was found in rocks associated with hydrocarbons in the Point Arguello and Lost Hills oil fields, where the Amm/(Amm + K) molar ratio of bulk samples ranges from 0.17-0.35. The formation of Amm-illite is suggested by the parallel increase in the percent of illite in the mixed-layered illite/smectite (I/S) and in the Amm/(Amm + K) molar ratio of the clay-sized fraction with increasing burial depth. Mineralization of Amm appears to be promoted by the coincident timing of the smectite-to-illite clay mineral transformation and the release of Amm during catagenesis. Amm-feldspar may form at shallow burial depths in rocks from the Point Arguello field that contain a greater amount of detrital K-feldspar and in which the I/S contains only 10-20% illite. Quartz-grade siliceous Monterey rocks from coastal outcrops in the Lions Head area lack significant amounts of hydrocarbons and have Amm/(Amm + K) molar ratios of 0.14-0.21. Rocks from the Lions Head area show a strong positive correlation between diagenetic illite and fixed-Amm contents, with Amm constituting 18-21 Mol% of the fixed interlayer cations in the I/S. The results of this study support the suggestion of Williams et al. (1989) that high fixed-Amm contents may provide a long-term geologic record of low-temperature (<150C) Amm mineralization associated with hydrocarbon generation and migration.

  16. Application of three fault growth criteria to the Puente Hills thrust system, Los Angeles, California, USA

    NASA Astrophysics Data System (ADS)

    Olson, Erik L.; Cooke, Michele L.

    2005-10-01

    Three-dimensional mechanical models are used to evaluate the performance of different fault growth criteria in predicting successive growth of three échelon thrust faults similar to the segments of the Puente Hills thrust system of the Los Angeles basin, California. Four sequential Boundary Element Method models explore the growth of successive échelon faults within the system by simulating snapshots of deformation at different stages of development. These models use three criteria, (1) energy release rate, (2) strain energy density, and (3) Navier-Coulomb stress, to characterize the lateral growth of the fault system. We simulate the growth of an échelon thrust fault system to evaluate the suitability of each of these criteria for assessing fault growth. Each of these three factors predicts a portion of the incipient fault geometry (i.e. location or orientation); however, each provides different information. In each model, energy release rate along the westernmost (leading) tip of the Puente Hills thrust drops with growth of the next neighboring fault; this result supports the overall lateral development of successive échelon segments. Within each model, regions of high strain energy density and Navier-Coulomb stress envelope at least a portion of the next fault to develop, although the strain energy density has stronger correlation than Navier-Coulomb stress to the location of incipient faulting. In each model, one of the two predicted planes of maximum Navier-Coulomb stress ahead of the leading fault tip matches the strike but not the dip of the incipient fault plane recreating part of the fault orientation. The incipient fault dip is best predicted by the orientation of the strain energy density envelopes around the leading fault tip. Furthermore, the energy release rate and pattern of strain energy density can be used to characterize potential soft linkage (overlap) or hard linkage (connection) of échelon faults within the system.

  17. ALS-based hummock size-distance relationship assessment of Mt Shasta debris avalanche deposit, Northern California, USA

    NASA Astrophysics Data System (ADS)

    Tortini, Riccardo; Carn, Simon; van Wyk de Vries, Benjamin

    2015-04-01

    The failure of destabilized volcano flanks is a likely occurrence during the lifetime of a stratovolcano, generating large debris avalanches and drastically changing landforms around volcanoes. The significant hazards associated with these events in the Cascade range were demonstrated, for example, by the collapse of Mt St Helens (WA), which triggered its devastating explosive eruption in 1980. The rapid modification of the landforms due to these events makes it difficult to estimate the magnitude of prehistoric avalanches. However, the widespread preservation of hummocks along the course of rockslide-debris avalanches is highly significant for understanding the physical characteristics of these landslides. Mt Shasta is a 4,317 m high, snow-capped, steep-sloped stratovolcano located in Northern California. The current edifice began forming on the remnants of an ancestral Mt Shasta that collapsed ~300-380k years ago producing one of the largest debris avalanches known on Earth. The debris avalanche deposit (DAD) covers a surface of ~450 km2 across the Shasta valley, with an estimated volume of ~26 km3. We analyze ALS data on hummocks from the prehistoric Shasta valley DAD in northern California (USA) to derive the relationship between hummock size and distance from landslide source, and interpret the geomorphic significance of the intercept and slope coefficients of the observed functional relationships. Given the limited extent of the ALS survey (i.e. 40 km2), the high-resolution dataset is used for validation of the morphological parameters extracted from freely available, broader coverage DTMs such as the National Elevation Dataset (NED). The ALS dataset also permits the identification of subtle topographic features not apparent in the field or in coarser resolution datasets, including a previously unmapped fault, of crucial importance for both seismic and volcanic hazard assessment in volcanic areas. We present evidence from the Shasta DAD of neotectonic

  18. Mineralogy and geochemistry of two metamorphosed sedimentary manganese deposits, Sierra Nevada, California, USA

    USGS Publications Warehouse

    Flohr, M.J.K.; Huebner, J.S.

    1992-01-01

    Laminated to massive rhodochrosite, hausmannite, and Mn-silicates from the Smith prospect and Manga-Chrome mine, Sierra Nevada, California were deposited as ocean floor sediments associated with chert and shale. The principal lithologies at Smith are chert, argillite, rhodochrosite-, hausmannite- and chlorite-rich layers, and relatively uncommon layers of jacobsite. The Manga-Chrome mine also contains layers rich in manganoan calcite and caryopilite. Tephroite, rhodonite, spessartine, and accessory alleghanyite and sonolite formed during metamorphism. Volcaniclastic components are present at Manga-Chrome as metavolcanic clasts and as Mn-poor, red, garnet- and hematite-rich layers. There is no evidence, such as relict lithologies, that Mn was introduced into Mn-poor lithologies such as chert, limestone or mudstone. Replacement of Mn-poor phases by Mn-rich phases is observed only in the groundmass of volcanic clasts that appear to have fallen into soft Mn-rich mud. Manganiferous samples from the Smith prospect and Manga-Chrome mine have high Mn Fe and low concentrations of Ni, Cu, Zn, Co, U, Th and the rare-earth elements that are similar to concentrations reported from other ancient Mn deposits found in chert-greenstone complexes and from manganiferous sediments and crusts that are forming near modern sea floor vents. The Sierra Nevada deposits formed as precipitates of Mn-rich sediments on the sea floor, probably from mixtures of circulating hydrothermal fluids and seawater. The composition of a metabasalt from the Smith prospect is consistent with those of island-arc tholeiites. Metavolcanic clasts from the Manga-Chrome mine are compositionally distinct from the Smith metabasalt and have alkaline to calc-alkaline affinities. A back-arc basin is considered to be the most likely paleoenvironment for the formation of the Mn-rich lenses at the Manga-Chrome mine and, by association, the Smith prospect. Layers of rhodochrosite, hausmannite and chert preserve the

  19. Organic matter sources and rehabilitation of the Sacramento-San Joaquin Delta (California, USA)

    USGS Publications Warehouse

    Jassby, A.D.; Cloern, J.E.

    2000-01-01

    1. The Sacramento San Joaquin River Delta, a complex mosaic of tidal freshwater habitats in California, is the focus of a major ecosystem rehabilitation effort because of significant long-term changes in critical ecosystem functions. One of these functions is the production, transport and transformation of organic matter that constitutes the primary food supply, which may be sub-optimal at trophic levels supporting fish recruitment. A long historical data set is used to define the most important organic matter sources, the factors underlying their variability, and the implications of ecosystem rehabilitation actions for these sources. 2. Tributary-borne loading is the largest organic carbon source on an average annual Delta-wide basis; phytoplankton production and agricultural drainage are secondary; wastewater treatment plant discharge, tidal marsh drainage and possibly aquatic macrophyte production are tertiary; and benthic microalgal production, urban run-off and other sources are negligible. 3. Allochthonous dissolved organic carbon must be converted to particulate form - with losses due to hydraulic flushing and to heterotroph growth inefficiency - before it becomes available to the metazoan food web. When these losses are accounted for, phytoplankton production plays a much larger role than is evident from a simple accounting of bulk organic carbon sources, especially in seasons critical for larval development and recruitment success. Phytoplankton-derived organic matter is also an important component of particulate loading to the Delta. 4. The Delta is a net producer of organic matter in critically dry years but, because of water diversion from the Delta, transport of organic matter from the Delta to important, downstream nursery areas in San Francisco Bay is always less than transport into the Delta from upstream sources. 5. Of proposed rehabilitation measures, increased use of floodplains probably offers the biggest increase in organic matter sources. 6

  20. Geochemical evidence for a complex origin for the Kelso dunes, Mojave National Preserve, California USA

    USGS Publications Warehouse

    Muhs, Daniel; Lancaster, Nicholas; Skipp, Gary L.

    2017-01-01

    The Kelso Dune field in southern California is intriguing because although it is of limited areal extent (~ 100 km2), it has a wide variety of dune forms and contains many active dunes (~ 40 km2), which is unusual in the Mojave Desert. Studies over the past eight decades have concluded that the dunes are derived primarily from a single source, Mojave River alluvium, under a dominant, westerly-to-northwesterly wind regime. The majority of these studies did not, however, present data to support the Mojave River as the only source. We conducted mineralogical and geochemical studies of most of the 14 geomorphically defined dune groups of the Kelso Dune field as well as potential sand sources, alluvial sediments from the surrounding mountain ranges. Results indicate that sands in the nine western dune groups have K/Rb and K/Ba (primarily from K-feldspar) compositions that are indistinguishable from Mojave River alluvium (westerly/northwesterly winds) and Budweiser Wash alluvium (southwesterly winds), permitting an interpretation of two sources. In contrast, sands from the five eastern dune groups have K/Rb and K/Ba values that indicate significant inputs from alluvial fan deposits of the Providence Mountains. This requires either rare winds from the east or southeast or, more likely, aeolian reworking of distal Providence Mountain fan sediments by winds from the west, at a rate greater than input from the Mojave River or other western sources. The results indicate that even a small dune field can have a complex origin, either from seasonally varying winds or complex alluvial-fan-dune interaction. Application of K/Rb and K/Ba in K-feldspar as a provenance indicator could be used in many of the world's ergs or sand seas, where dune origins are still not well understood or are controversial. Four examples are given from Africa and the Middle East where such an approach could yield useful new information about dune sand provenance.

  1. Continuous monitoring of an earth fissure in Chino, California, USA - a management tool

    NASA Astrophysics Data System (ADS)

    Carpenter, M. C.

    2015-11-01

    Continuous measurements of deformation have been made in Chino, California across an earth fissure and nearby unfissured soil since 2011 in two buried, horizontal, 150 mm pipes, 51 m long, which are connected by sealed boxes enclosing vertical posts at mostly 6 m intervals. Horizontal displacements and normal strain are measured in one line using nine end-to-end quartz tubes that are attached to posts and span fissured or unfissured soil. The free ends of the tubes are supported by slings and move relative to the attachment post of the next quartz tube. Linear variable differential transformer (LVDT) sensors measure the relative movements. Five biaxial tilt sensors were also attached to selected posts in that line. Relative vertical movement was measured at nine locations along the line in the second pipe using low-level differential pressure sensors. The second pipe is half full of water giving a free water surface along its length. Data are recorded on a Campbell CR10 using multiplexers. The quartz-tube horizontal extensometers have exhibited more than 3 mm of predominantly elastic opening and closing in response to about 32 m of seasonal drawdown and recovery, respectively, in an observation well 0.8 km to the south. The nearest production well is 1.6 km to the west. The horizontal strain was 5.9 × 10-5 or 30 % of the lowest estimate of strain-at-failure for alluvium. Maximum relative vertical movement was 4.8 mm. Maximum tilt in the fissure zone was 0.09 arcdeg while tilt at a separate sensor 100 m to the east was 0.86 arcdeg, indicating a wider zone of deformation than is spanned by the instrumentation. High correlation of horizontal displacements during drawdown, and especially recovery, with change in effective stress supports differential compaction as the mechanism for earth-fissure movement. The continuous measurements of horizontal strain coupled with water-level fluctuations and vertical borehole extensometry can provide a real-time adaptive management

  2. A regional-scale study of chromium and nickel in soils of northern California, USA

    USGS Publications Warehouse

    Morrison, J.M.; Goldhaber, M.B.; Lee, L.; Holloway, J.M.; Wanty, R.B.; Wolf, R.E.; Ranville, J.F.

    2009-01-01

    A soil geochemical survey was conducted in a 27,000-km2 study area of northern California that includes the Sierra Nevada Mountains, the Sacramento Valley, and the northern Coast Range. The results show that soil geochemistry in the Sacramento Valley is controlled primarily by the transport and weathering of parent material from the Coast Range to the west and the Sierra Nevada to the east. Chemically and mineralogically distinctive ultramafic (UM) rocks (e.g. serpentinite) outcrop extensively in the Coast Range and Sierra Nevada. These rocks and the soils derived from them have elevated concentrations of Cr and Ni. Surface soil samples derived from UM rocks of the Sierra Nevada and Coast Range contain 1700-10,000 mg/kg Cr and 1300-3900 mg/kg Ni. Valley soils west of the Sacramento River contain 80-1420 mg/kg Cr and 65-224 mg/kg Ni, reflecting significant contributions from UM sources in the Coast Range. Valley soils on the east side contain 30-370 mg/kg Cr and 16-110 mg/kg Ni. Lower Cr and Ni concentrations on the east side of the valley are the result of greater dilution by granitic sources of the Sierra Nevada. Chromium occurs naturally in the Cr(III) and Cr(VI) oxidation states. Trivalent Cr is a non-toxic micronutrient, but Cr(VI) is a highly soluble toxin and carcinogen. X-ray diffraction and scanning electron microscopy of soils with an UM parent show Cr primarily occurs within chromite and other mixed-composition spinels (Al, Mg, Fe, Cr). Chromite contains Cr(III) and is highly refractory with respect to weathering. Comparison of a 4-acid digestion (HNO3, HCl, HF, HClO4), which only partially dissolves chromite, and total digestion by lithium metaborate (LiBO3) fusion, indicates a lower proportion of chromite-bound Cr in valley soils relative to UM source soils. Groundwater on the west side of the Sacramento Valley has particularly high concentrations of dissolved Cr ranging up to 50 ??g L-1 and averaging 16.4 ??g L-1. This suggests redistribution of Cr

  3. Electromagnetic imaging the of the Pacific-North American plate boundary in central California, USA

    NASA Astrophysics Data System (ADS)

    Wheelock, B. D.; Constable, S.; Key, K. W.

    2010-12-01

    The continental margin of central California lies adjacent to a segment of the San Andreas fault (SAF) that exhibits a transition between locked behavior south of the town of Cholame, and freely slipping (creeping) behavior north of the town of Parkfield. Recent reports of non-volcanic tremor (NVT) near the town of Cholame represent the first observation of NVT in a strike-slip environment. Dense clusters of tremor episodes located at the northern limit of the locked section of the SAF were found to originate within the ductile lower crust at depths between 15 and 30~km, and have been interpreted as evidence of high pore fluid pressure. An excess of fluids in this region is likely given its history of subduction, which transports large quantities of water into the forearc crust and mantle. We present a study that uses deep electromagnetic imaging methods to estimate the abundance and distribution of pore fluids at depths associated with non-volcanic tremor. This study extends a previously collected terrestrial profile of magnetotelluric (MT) data (Becken et al. 2008, Geophysical Journal International) into the offshore environment. We deployed 21 seafloor instruments that collected controlled-source electromagnetic (CSEM) and MT data in a line extending from the coast near Morro Bay, across the continental shelf, and out onto the Pacific plate. The marine MT data results in apparent resistivity and phase estimates at periods between 1~s and 20,000~s, sufficient for probing the upper 100~km of regional conductivity. A significant coast effect, marked by asymptotic behavior in the TE mode of the MT responses, is observed at the deep water sites. This necessitates accurate bathymetry modeling when inverting. The CSEM transmitter was towed by all receivers broadcasting a compact broadband binary waveform with a 0.25~Hz fundamental frequency. The controlled-source signal is observed above the noisefloor at source-receiver offsets up to 6~km, which provides constraints

  4. Cretaceous planktic foraminiferal biostratigraphy of the Calera Limestone, Northern California, USA

    USGS Publications Warehouse

    Sliter, W.V.

    1999-01-01

    The Calera Limestone is the largest, most stratigraphically extensive limestone unit of oceanic character included in the Franciscan Complex of northern California. The aim of this paper is to place the Calera Limestone at its type locality (Rockaway Beach, Pacifica) in a high-resolution biostratigraphy utilizing planktic foraminifers studied in thin section. A section, about 110 m-thick, was measured from the middle thrust slice exposed by quarrying on the southwest side of Calera Hill at Pacifica Quarry. Lithologically, the section is divided in two units; a lower unit with 73 m of black to dark-grey limestone, black chert and tuff, and an upper unit with 36.8 m of light-grey limestone and medium-grey chert. Two prominent black-shale layers rich in organic carbon occur 11 m below the top of the lower black unit and at the boundary with overlying light-grey unit, yielding a total organic content (TOC) of 4.7% and 1.8% t.w., respectively. The fossiliferous Calera Limestone section measured at Pacifica Quarry, from the lower black shale, contains eleven zones and three subzones that span approximately 26 m.y. from the early Aptian to the late Cenomanian. The zones indentified range from the Globigerinelloides blowi Zone to the Dicarinella algeriana Subzone of the Rotalipora cushmani Zone. Within this biostratigraphic interval, the Ticinella bejaouaensis and Hedbergella planispira Zones at the Aptian/Albian boundary are missing as are the Rotalipora subticinensis Subzone of the Biticinella breggiensis Zone and the overlying Rotalipora ticinensis Zone in the late Albian owing both to low-angle thrust faulting and to unconformities. The abundance and preservation of planktic foraminifers are poor in the lower part and improve only within the upper G. algerianus Zone. The faunal relationship indicate that the lower black shale occurs in the upper part of the G. blowi Zone and correlates with the Selli Event recognized at global scale in the early Aptian. The upper black

  5. A statistical learning framework for groundwater nitrate models of the Central Valley, California, USA

    USGS Publications Warehouse

    Nolan, Bernard T.; Fienen, Michael N.; Lorenz, David L.

    2015-01-01

    We used a statistical learning framework to evaluate the ability of three machine-learning methods to predict nitrate concentration in shallow groundwater of the Central Valley, California: boosted regression trees (BRT), artificial neural networks (ANN), and Bayesian networks (BN). Machine learning methods can learn complex patterns in the data but because of overfitting may not generalize well to new data. The statistical learning framework involves cross-validation (CV) training and testing data and a separate hold-out data set for model evaluation, with the goal of optimizing predictive performance by controlling for model overfit. The order of prediction performance according to both CV testing R2 and that for the hold-out data set was BRT > BN > ANN. For each method we identified two models based on CV testing results: that with maximum testing R2 and a version with R2 within one standard error of the maximum (the 1SE model). The former yielded CV training R2 values of 0.94–1.0. Cross-validation testing R2 values indicate predictive performance, and these were 0.22–0.39 for the maximum R2 models and 0.19–0.36 for the 1SE models. Evaluation with hold-out data suggested that the 1SE BRT and ANN models predicted better for an independent data set compared with the maximum R2 versions, which is relevant to extrapolation by mapping. Scatterplots of predicted vs. observed hold-out data obtained for final models helped identify prediction bias, which was fairly pronounced for ANN and BN. Lastly, the models were compared with multiple linear regression (MLR) and a previous random forest regression (RFR) model. Whereas BRT results were comparable to RFR, MLR had low hold-out R2 (0.07) and explained less than half the variation in the training data. Spatial patterns of predictions by the final, 1SE BRT model agreed reasonably well with previously observed patterns of nitrate occurrence in groundwater of the Central Valley.

  6. Rockfall hazard and risk assessment in the Yosemite Valley, California, USA

    USGS Publications Warehouse

    Guzzetti, F.; Reichenbach, P.; Wieczorek, G.F.

    2003-01-01

    Rock slides and rock falls are the most frequent types of slope movements in Yosemite National Park, California. In historical time (1857-2002) 392 rock falls and rock slides have been documented in the valley, and some of them have been mapped in detail. We present the results of an attempt to assess rock fall hazards in the Yosemite Valley. Spatial and temporal aspects of rock falls hazard are considered. A detailed inventory of slope movements covering the 145-year period from 1857 to 2002 is used to determine the frequency-volume statistics of rock falls and to estimate the annual frequency of rock falls, providing the temporal component of rock fall hazard. The extent of the areas potentially subject to rock fall hazards in the Yosemite Valley were obtained using STONE, a physically-based rock fall simulation computer program. The software computes 3-dimensional rock fall trajectories starting from a digital elevation model (DEM), the location of rock fall release points, and maps of the dynamic rolling friction coefficient and of the coefficients of normal and tangential energy restitution. For each DEM cell the software calculates the number of rock falls passing through the cell, the maximum rock fall velocity and the maximum flying height. For the Yosemite Valley, a DEM with a ground resolution of 10 ?? 10 m was prepared using topographic contour lines from the U.S. Geological Survey 1:24 000-scale maps. Rock fall release points were identified as DEM cells having a slope steeper than 60??, an assumption based on the location of historical rock falls. Maps of the normal and tangential energy restitution coefficients and of the rolling friction coefficient were produced from a surficial geologic map. The availability of historical rock falls mapped in detail allowed us to check the computer program performance and to calibrate the model parameters. Visual and statistical comparison of the model results with the mapped rock falls confirmed the accuracy of

  7. Insights into controls on hexavalent chromium in groundwater provided by environmental tracers, Sacramento Valley, California, USA

    USGS Publications Warehouse

    Manning, Andrew H.; Mills, Christopher; Morrison, Jean M.; Ball, Lyndsay B.

    2015-01-01

    Environmental tracers are useful for determining groundwater age and recharge source, yet their application in studies of geogenic Cr(VI) in groundwater has been limited. Environmental tracer data from 166 wells located in the Sacramento Valley, northern California, were interpreted and compared to Cr concentrations to determine the origin and age of groundwater with elevated Cr(VI), and better understand where Cr(VI) becomes mobilized and how it evolves along flowpaths. In addition to major ion and trace element concentrations, the dataset includes δ18O, δ2H, 3H concentration, 14C activity (of dissolved inorganic C), δ13C, 3He/4He ratio, and noble gas concentrations (He, Ne, Ar, Kr, Xe). Noble gas recharge temperatures (NGTs) were computed, and age-related tracers were interpreted in combination to constrain the age distribution in samples and sort them into six different age categories spanning from <60 yr old to >10,000 yr old. Nearly all measured Cr is in the form of Cr(IV). Concentrations range from <1 to 46 μg L−1, with 10% exceeding the state of California’s Cr(VI) maximum contaminant level of 10 μg L−1. Two groups with elevated Cr(VI) (⩾5 μg L−1) were identified. Group 1 samples are from the southern part of the valley and contain modern (<60 yr old) water, have elevated NO3− concentrations (>3 mg L−1), and commonly have δ18O values enriched relative to local precipitation. These samples likely contain irrigation water and are elevated due to accelerated mobilization of Cr(VI) in the unsaturated zone (UZ) in irrigated areas. Group 2 samples are from throughout the valley and typically contain water 1000–10,000 yr old, have δ18O values consistent with local precipitation, and have unexpectedly warm NGTs. Chromium(VI) concentrations in Group 2 samples may be elevated for multiple reasons, but the hypothesis most consistent with all available data (notably, the warm NGTs) is a relatively long UZ residence time due to

  8. Sources of high-chloride water and managed aquifer recharge in an alluvial aquifer in California, USA

    NASA Astrophysics Data System (ADS)

    O'Leary, David R.; Izbicki, John A.; Metzger, Loren F.

    2015-11-01

    As a result of pumping in excess of recharge, water levels in alluvial aquifers within the Eastern San Joaquin Groundwater Subbasin, 130 km east of San Francisco (California, USA), declined below sea level in the early 1950s and have remained so to the present. Chloride concentrations in some wells increased during that time and exceeded the US Environmental Protection Agency's secondary maximum contaminant level of 250 mg/L, resulting in removal of some wells from service. Sources of high-chloride water include irrigation return in 16 % of sampled wells and water from delta sediments and deeper groundwater in 50 % of sampled wells. Chloride concentrations resulting from irrigation return commonly did not exceed 100 mg/L, although nitrate concentrations were as high as 25 mg/L as nitrogen. Chloride concentrations ranged from less than 100-2,050 mg/L in wells affected by water from delta sediments and deeper groundwater. Sequential electromagnetic logs show movement of high-chloride water from delta sediments to pumping wells through permeable interconnected aquifer layers. δD and δ18O data show most groundwater originated as recharge along the front of the Sierra Nevada, but tritium and carbon-14 data suggest recharge rates in this area are low and have decreased over recent geologic time. Managed aquifer recharge at two sites show differences in water-level responses to recharge and in the physical movement of recharged water with depth related to subsurface geology. Well-bore flow logs also show rapid movement of water from recharge sites through permeable interconnected aquifer layers to pumping wells.

  9. Use of turbidometry to characterize suspended sediment and phosphorus fluxes in the Lake Tahoe basin, California, USA

    NASA Astrophysics Data System (ADS)

    Stubblefield, Andrew P.; Reuter, John E.; Dahlgren, Randy A.; Goldman, Charles R.

    2007-01-01

    The efficacy of in-stream nephelometric turbidometry as a surrogate for total suspended solids (TSS) and total phosphorus (TP) concentrations was evaluated for use in low turbidity (<50 NTU) subalpine watersheds at Lake Tahoe, California-Nevada, USA. Continuous turbidity records for the 1999, 2000 and 2001 snowmelt seasons and data from water quality samples (1982-2000) were examined to determine watershed sediment delivery dynamics. Strong correlations were found between turbidity and both TSS and TP concentration. The strong correlation indicates that turbidity can serve as a good surrogate for direct measurement in these watersheds. The watersheds displayed clockwise hysteresis: sediment flushing and depletion, on daily, seasonal and decadal time-scales. The hysteresis curves had strong concave shapes, indicating a sensitive response to peak flow. A pronounced seasonal trend was observed for the ratio of suspended sediment concentration (SSC)/discharge over time, indicating early season flushing of available sediment. Significant linear relationships (p < 0.05) were found for 12 of 17 years. Comparison of annual sediment rating curve coefficients indicated smaller coefficients during high sediment loading years and in the years following. The smaller coefficients are evidence of sediment depletion during high flow years. The effect of hysteresis on monitoring methods was illustrated by comparing turbidity estimates of TSS load with sediment rating curve estimates of SSC. After accounting for differences in SSC/TSS methods of analysis, daily loads calculated with turbidity methods were 58-98% of rating curve estimates for the spring snowmelt seasons of 1999-2001. Copyright

  10. Present-day oxidative subsidence of organic soils and mitigation in the Sacramento-San Joaquin Delta, California, USA.

    PubMed

    Deverel, Steven J; Ingrum, Timothy; Leighton, David

    Subsidence of organic soils in the Sacramento-San Joaquin Delta threatens sustainability of the California (USA) water supply system and agriculture. Land-surface elevation data were collected to assess present-day subsidence rates and evaluate rice as a land use for subsidence mitigation. To depict Delta-wide present-day rates of subsidence, the previously developed SUBCALC model was refined and calibrated using recent data for CO2 emissions and land-surface elevation changes measured at extensometers. Land-surface elevation change data were evaluated relative to indirect estimates of subsidence and accretion using carbon and nitrogen flux data for rice cultivation. Extensometer and leveling data demonstrate seasonal variations in land-surface elevations associated with groundwater-level fluctuations and inelastic subsidence rates of 0.5-0.8 cm yr(-1). Calibration of the SUBCALC model indicated accuracy of ±0.10 cm yr(-1) where depth to groundwater, soil organic matter content and temperature are known. Regional estimates of subsidence range from <0.3 to >1.8 cm yr(-1). The primary uncertainty is the distribution of soil organic matter content which results in spatial averaging in the mapping of subsidence rates. Analysis of leveling and extensometer data in rice fields resulted in an estimated accretion rate of 0.02-0.8 cm yr(-1). These values generally agreed with indirect estimates based on carbon fluxes and nitrogen mineralization, thus preliminarily demonstrating that rice will stop or greatly reduce subsidence. Areas below elevations of -2 m are candidate areas for implementation of mitigation measures such as rice because there is active subsidence occurring at rates greater than 0.4 cm yr(-1).

  11. Temporal and spatial variation of atmospherically deposited organic contaminants at high elevation in Yosemite National Park, California, USA.

    PubMed

    Bradford, David F; Stanley, Kerri A; Tallent, Nita G; Sparling, Donald W; Nash, Maliha S; Knapp, Roland A; McConnell, Laura L; Massey Simonich, Staci L

    2013-03-01

    Contaminants used at low elevation, such as pesticides on crops, can be transported tens of kilometers and deposited in adjacent mountains in many parts of the world. Atmospherically deposited organic contaminants in the Sierra Nevada Mountains of California, USA, have exceeded some thresholds of concern, but the spatial and temporal distributions of contaminants in the mountains are not well known. The authors sampled shallow-water sediment and tadpoles (Pseudacris sierra) for pesticides, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls in four high-elevation sites in Yosemite National Park in the central Sierra Nevada twice during the summers of 2006, 2007, and 2008. Both historic- and current-use pesticides showed a striking pattern of lower concentrations in both sediment and tadpoles in Yosemite than was observed previously in Sequoia-Kings Canyon National Parks in the southern Sierra Nevada. By contrast, PAH concentrations in sediment were generally greater in Yosemite than in Sequoia-Kings Canyon. The authors suggest that pesticide concentrations tend to be greater in Sequoia-Kings Canyon because of a longer air flow path over agricultural lands for this park along with greater pesticide use near this park. Concentrations for DDT-related compounds in some sediment samples exceeded guidelines or critical thresholds in both parks. A general pattern of difference between Yosemite and Sequoia-Kings Canyon was not evident for total tadpole cholinesterase activity, an indicator of harmful exposure to organophosphorus and carbamate pesticides. Variability of chemical concentrations among sites, between sampling periods within each year, and among years, contributed significantly to total variation, although the relative contributions differed between sediment and tadpoles.

  12. Present-day oxidative subsidence of organic soils and mitigation in the Sacramento-San Joaquin Delta, California, USA

    NASA Astrophysics Data System (ADS)

    Deverel, Steven J.; Ingrum, Timothy; Leighton, David

    2016-05-01

    Subsidence of organic soils in the Sacramento-San Joaquin Delta threatens sustainability of the California (USA) water supply system and agriculture. Land-surface elevation data were collected to assess present-day subsidence rates and evaluate rice as a land use for subsidence mitigation. To depict Delta-wide present-day rates of subsidence, the previously developed SUBCALC model was refined and calibrated using recent data for CO2 emissions and land-surface elevation changes measured at extensometers. Land-surface elevation change data were evaluated relative to indirect estimates of subsidence and accretion using carbon and nitrogen flux data for rice cultivation. Extensometer and leveling data demonstrate seasonal variations in land-surface elevations associated with groundwater-level fluctuations and inelastic subsidence rates of 0.5-0.8 cm yr-1. Calibration of the SUBCALC model indicated accuracy of ±0.10 cm yr-1 where depth to groundwater, soil organic matter content and temperature are known. Regional estimates of subsidence range from <0.3 to >1.8 cm yr-1. The primary uncertainty is the distribution of soil organic matter content which results in spatial averaging in the mapping of subsidence rates. Analysis of leveling and extensometer data in rice fields resulted in an estimated accretion rate of 0.02-0.8 cm yr-1. These values generally agreed with indirect estimates based on carbon fluxes and nitrogen mineralization, thus preliminarily demonstrating that rice will stop or greatly reduce subsidence. Areas below elevations of -2 m are candidate areas for implementation of mitigation measures such as rice because there is active subsidence occurring at rates greater than 0.4 cm yr-1.

  13. Does prescribed fire promote resistance to drought in low elevation forests of the Sierra Nevada, California, USA?

    USGS Publications Warehouse

    van Mantgem, Phillip J.; Caprio, Anthony C.; Stephenson, Nathan L.; Das, Adrian J.

    2016-01-01

    Prescribed fire is a primary tool used to restore western forests following more than a century of fire exclusion, reducing fire hazard by removing dead and live fuels (small trees and shrubs).  It is commonly assumed that the reduced forest density following prescribed fire also reduces competition for resources among the remaining trees, so that the remaining trees are more resistant (more likely to survive) in the face of additional stressors, such as drought.  Yet this proposition remains largely untested, so that managers do not have the basic information to evaluate whether prescribed fire may help forests adapt to a future of more frequent and severe drought.During the third year of drought, in 2014, we surveyed 9950 trees in 38 burned and 18 unburned mixed conifer forest plots at low elevation (<2100 m a.s.l.) in Kings Canyon, Sequoia, and Yosemite national parks in California, USA.  Fire had occurred in the burned plots from 6 yr to 28 yr before our survey.  After accounting for differences in individual tree diameter, common conifer species found in the burned plots had significantly reduced probability of mortality compared to unburned plots during the drought.  Stand density (stems ha-1) was significantly lower in burned versus unburned sites, supporting the idea that reduced competition may be responsible for the differential drought mortality response.  At the time of writing, we are not sure if burned stands will maintain lower tree mortality probabilities in the face of the continued, severe drought of 2015.  Future work should aim to better identify drought response mechanisms and how these may vary across other forest types and regions, particularly in other areas experiencing severe drought in the Sierra Nevada and on the Colorado Plateau.

  14. Building Topographically Modified Tree-Ring Chronologies from High Elevation Bristlecone Pine in the White Mountains of California, USA

    NASA Astrophysics Data System (ADS)

    Bunn, A. G.; Hughes, M. K.; Salzer, M. W.

    2010-12-01

    We analyze growth rates of dozens of high elevation (~3400 m.a.s.l.) bristlecone pine trees (Pinus longaeva D.K. Bailey) from the White Mountains of California, USA by exploiting the biophysical position of the individual trees. Recent work has shown that 20th century growth in the highest elevation bristlecone pine is greater than at any point in recent millennia. This phenomenon is coincident with increased temperatures over the instrumental climate record. While both temperature and moisture availability appear to influence growth, the trade-off of these limiting factors is not well understood. The White Mountains are dominated by steep, rugged terrain. We suggest that even in relatively small areas, the complexity of terrain in high mountain systems can alter the limiting growth factors of individual trees and that these differences may be of value to better understand bristlecone pine growth. In a multivariate analysis we are able to isolate different patterns of growth based that are associated with topographic indices reflecting variations in local temperature lapse rates and soil moisture anomalies. When we build topographically modified mean ring-width chronologies along these gradients we find substantial variation between the chronologies in the time and frequency domains. We also find that the correlations with the instrumental climate record vary and that we are partially able to unmix temperature versus precipitation signals. These differences appear consistent with mechanistic understanding of the control of tree-ring variability using a process-based model. If these results are robust, the calculation of climate reconstructions using ring-width data from these trees could be placed on a firmer, clearer, basis.

  15. Sources of high-chloride water and managed aquifer recharge in an alluvial aquifer in California, USA

    USGS Publications Warehouse

    O'Leary, David; Izbicki, John A.; Metzger, Loren F.

    2015-01-01

    As a result of pumping in excess of recharge, water levels in alluvial aquifers within the Eastern San Joaquin Groundwater Subbasin, 130 km east of San Francisco (California, USA), declined below sea level in the early 1950s and have remained so to the present. Chloride concentrations in some wells increased during that time and exceeded the US Environmental Protection Agency’s secondary maximum contaminant level of 250 mg/L, resulting in removal of some wells from service. Sources of high-chloride water include irrigation return in 16 % of sampled wells and water from delta sediments and deeper groundwater in 50 % of sampled wells. Chloride concentrations resulting from irrigation return commonly did not exceed 100 mg/L, although nitrate concentrations were as high as 25 mg/L as nitrogen. Chloride concentrations ranged from less than 100–2,050 mg/L in wells affected by water from delta sediments and deeper groundwater. Sequential electromagnetic logs show movement of high-chloride water from delta sediments to pumping wells through permeable interconnected aquifer layers. δD and δ18O data show most groundwater originated as recharge along the front of the Sierra Nevada, but tritium and carbon-14 data suggest recharge rates in this area are low and have decreased over recent geologic time. Managed aquifer recharge at two sites show differences in water-level responses to recharge and in the physical movement of recharged water with depth related to subsurface geology. Well-bore flow logs also show rapid movement of water from recharge sites through permeable interconnected aquifer layers to pumping wells.

  16. Geochemistry of tectonically expelled fluids from the northern Coast ranges, Rumsey Hills, California, USA

    USGS Publications Warehouse

    Davisson, M.L.; Presser, T.S.; Criss, R.E.

    1994-01-01

    Tectonic compression has created abnormally high pressure on deep basinal fluids causing their expulsion from areally exposed Upper Cretaceous rock along the eastern margin of the California Coast ranges. The fluids emerge as near-neutral, perennial sodium chloride springs at high elevations with flow rates as high as 10 L per min. Higher spring discharges are more common around the exposure of a west-vergent fault propagation fold axis. Spring waters range from ~1000 to 27,000 mg/L TDS. The least saline water (??18O = -7.5???) closely represents local meteoric water that mixes with saline fluid (??18O = +5.3???) and forms a slope of ~3.5 on a ??D vs. ??18O plot. A Na (125 to 8000 mg/L) vs. Cl (150 to 17,000 mg/L) plot shows a linear dilution trend that extends close to, but below, the values for modern seawater. Calcium (75-3000 mg/L) is considerably enriched relative to seawater and forms a nonlinear trend with chloride. In detail, the "Na deficit," defined by the difference between the measured Na content and the Na concentration on a hypothetical seawater dilution line, is approximately balanced by the Ca excess, similarly defined by the seawater dilution line. This relationship strongly suggests that the fluid is diluted seawater that is being modified by active albitization of plagioclase at different depths. Simultaneous B and 18O enrichment of the fluids, accompanied by deuterium depletion, further suggest that the seawater modification is influenced by clay diagenesis. Bicarbonate and SiO2 concentrations show an inverse correlation with Cl, with most waters being saturated or slightly oversaturated with calcite and quartz at the discharge temperatures. Some freshwater springs with near-meteoric stable isotope values may represent mixing of young groundwater from perched aquifers, but in many cases, the freshwater springs emerge along the same structures and have the same perennial nature as the saline fluids, and expulsion of an older fresh groundwater

  17. Proparasitylenchus californicus n. sp. (Tylenchida: Allantonematidae), parasitic in the intertidal rove beetle Tarphiota geniculata (Mäklin) (Coleoptera: Staphylinidae) in California, USA.

    PubMed

    Poinar, George; Datlen, Nicole; Espinoza, Magaly; McLaughlin, John

    2015-09-01

    A new nematode species, Proparasitylenchus californicus n. sp., is described from the intertidal rove beetle Tarphiota geniculata (Mäklin) (Coleoptera: Staphylinidae) in California, USA. The new species differs from European representatives of the genus by possessing a cleft stylet in both sexes. The parasitic female is ovoviviparous and produces numerous juveniles that moult twice in the beetle host, then exit and moult twice to the adult stage in the environment. After mating, the free-living fertilised females enter a new host. Heavy infections sterilise the beetles. This is the first record of the genus Proparasitylenchus Wachek, 1955 in the New World and the first allantonematid parasite of a marine, intertidal beetle.

  18. Improving assessments of tropospheric ozone injury to Mediterranean montane conifer forests in California (USA) and Catalonia (Spain) with GIS models related to plant water relations

    NASA Astrophysics Data System (ADS)

    Kefauver, Shawn C.; Peñuelas, Josep; Ustin, Susan L.

    2012-12-01

    The impacts of tropospheric ozone on conifer health in the Sierra Nevada of California, USA, and the Pyrenees of Catalonia, Spain, were measured using field assessments and GIS variables of landscape gradients related to plant water relations, stomatal conductance and hence to ozone uptake. Measurements related to ozone injury included visible chlorotic mottling, needle retention, needle length, and crown depth, which together compose the Ozone Injury Index (OII). The OII values observed in Catalonia were similar to those in California, but OII alone correlated poorly to ambient ozone in all sites. Combining ambient ozone with GIS variables related to landscape variability of plant hydrological status, derived from stepwise regressions, produced models with R2 = 0.35, p = 0.016 in Catalonia, R2 = 0.36, p < 0.001 in Yosemite and R2 = 0.33, p = 0.007 in Sequoia/Kings Canyon National Parks in California. Individual OII components in Catalonia were modeled with improved success compared to the original full OII, in particular visible chlorotic mottling (R2 = 0.60, p < 0.001). The results show that ozone is negatively impacting forest health in California and Catalonia and also that modeling ozone injury improves by including GIS variables related to plant water relations.

  19. 33 CFR 110.115 - Santa Barbara Harbor, Calif.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Santa Barbara Harbor, Calif. 110... ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.115 Santa Barbara Harbor, Calif. North of the Santa Barbara breakwater; seaward of the line of mean high water; and southwest of a line bearing...

  20. Investigating the Sources and Dynamics of Dissolved Organic Matter in an Agricultural Watershed in California (U.S.A.)

    NASA Astrophysics Data System (ADS)

    Dyda, R. Y.; Hernes, P. J.; Spencer, R. G.; Ingrum, T. D.; Pellerin, B. A.; Bergamaschi, B. A.

    2007-12-01

    Dissolved organic matter (DOM) is ubiquitous and plays critical roles in nutrient cycling, aquatic food webs and numerous other biogeochemical processes. Furthermore, various factors control the quality and quantity of DOM, including land use, soil composition, in situ production, microbial uptake and assimilation and hydrology. As a component of DOM, dissolved organic carbon (DOC) has been recently identified as a drinking water constituent of concern due to its propensity to form EPA-regulated carcinogenic compounds when disinfected for drinking water purposes. Therefore, understanding the sources, cycling and modification of DOC across various landscapes is of direct relevance to a wide range of studies. The Willow Slough watershed is located in the Central Valley of California (U.S.A.) and is characterized by both diverse geomorphology as well as land use. The watershed drains approximately 425 km2 and is bordered by Cache and Putah Creeks to the north and south. The study area in the watershed includes the eastern portion of the foothills of the inner Coast Range and the alluvial plain and encompasses diverse land uses, including orchards, viticulture, dairy, pasture and natural grasslands. The Willow Slough watershed represents a unique opportunity to examine DOC dynamics through multiple land uses and hydrologic flow paths that are common throughout California. Preliminary data show that DOC concentrations at the watershed mouth peak during winter storms and also increase gradually throughout the summer months during the agricultural irrigation season. The increasing DOC concentrations during the summer months may result from agricultural runoff and/or primary production in channel. In addition, initial results using the chromophoric DOM (CDOM) absorption coefficient and spectral slope parameters indicate seasonal differences in the composition of the DOM. Spectral slopes decreased during both the summer irrigation season and winter storms relative to winter

  1. Methylmercury production in sediment from agricultural and non-agricultural wetlands in the Yolo Bypass, California, USA

    USGS Publications Warehouse

    Marvin-DiPasquale, Mark; Windham-Myers, Lisamarie; Agee, Jennifer L.; Kakouros, Evangelos; Kieu, Le H.; Fleck, Jacob A.; Alpers, Charles N.; Stricker, Craig A.

    2014-01-01

    As part of a larger study of mercury (Hg) biogeochemistry and bioaccumulation in agricultural (rice growing) and non-agricultural wetlands in California's Central Valley, USA, seasonal and spatial controls on methylmercury (MeHg) production were examined in surface sediment. Three types of shallowly-flooded agricultural wetlands (white rice, wild rice, and fallow fields) and two types of managed (non-agricultural) wetlands (permanently and seasonally flooded) were sampled monthly-to-seasonally. Dynamic seasonal changes in readily reducible ‘reactive’ mercury (Hg(II)R), Hg(II)-methylation rate constants (kmeth), and concentrations of electron acceptors (sulfate and ferric iron) and donors (acetate), were all observed in response to field management hydrology, whereas seasonal changes in these parameters were more muted in non-agricultural managed wetlands. Agricultural wetlands exhibited higher sediment MeHg concentrations than did non-agricultural wetlands, particularly during the fall through late-winter (post-harvest) period. Both sulfate- and iron-reducing bacteria have been implicated in MeHg production, and both were demonstrably active in all wetlands studied. Stoichiometric calculations suggest that iron-reducing bacteria dominated carbon flow in agricultural wetlands during the growing season. Sulfate-reducing bacteria were not stimulated by the addition of sulfate-based fertilizer to agricultural wetlands during the growing season, suggesting that labile organic matter, rather than sulfate, limited their activity in these wetlands. Along the continuum of sediment geochemical conditions observed, values of kmeth increased approximately 10,000-fold, whereas Hg(II)R decreased 100-fold. This suggests that, with respect to the often opposing trends of Hg(II)-methylating microbial activity and Hg(II) availability for methylation, microbial activity dominated the Hg(II)-methylation process, and that along this biogeochemical continuum, conditions that favored

  2. The western pond turtle (Clemmys marmorata) in the Mojave River, California, USA: Highly adapted survivor or tenuous relict?

    USGS Publications Warehouse

    Lovich, J.; Meyer, K.

    2002-01-01

    Aspects of the ecology of populations of the western pond turtle Clemmys marmorata were investigated in the Mojave River of the central Mojave Desert, California, U.S.A. One population occupied man-made ponds and the other occurred in natural ponds in the flood plain of the Mojave River. Both habitats are severely degraded as a result of ground water depletion from human activities along the river and one is infested with the exotic shrub saltcedar Tamarix ramosissima. Mean female carapace length (CL) was significantly greater (14.4 cm) than that of males (13.7 cm). Live juveniles were not detected during the period of study. Shelled eggs were visible in X-radiographs from 26 May to 14 July. Mean clutch size was 4.46 and ranged from 3 to 6 eggs. Clutch size did not vary between 1998 and 1999 but was significantly correlated with CL for both years combined, increasing at the rate of 0.548 eggs/cm CL. Gravid female CL ranged from 13.3-16.0 cm. Some females nested in both years. Mean X-ray egg width (21.8 mm) was not significantly correlated with CL or clutch size. X-ray egg width differed more among clutches than within, whether including CL as a co-variate or not. Nesting migrations occurred from 6 June to 8 July with minimum round trip distances ranging from 17.5-585 m with a mean of 195 m. Mean estimated time of departure as measured at the drift fence was 18:13. Most females returned to the ponds in the early morning. Nesting migrations required females to be out of the water for estimated periods of 0.83 to 86 h. The destination of nesting females was typically fluvial sand bars in the channel of the dry riverbed. Overall, the ecology of C. marmorata in the Mojave River is very similar to that reported for populations in less severe habitats along the west coast of the United States. Notable exceptions include long nesting migrations to sandbars in the dry river channel, a possible result of human modifications to the environment, and an apparent lack of

  3. Methylmercury production in sediment from agricultural and non-agricultural wetlands in the Yolo Bypass, California, USA.

    PubMed

    Marvin-DiPasquale, Mark; Windham-Myers, Lisamarie; Agee, Jennifer L; Kakouros, Evangelos; Kieu, Le H; Fleck, Jacob A; Alpers, Charles N; Stricker, Craig A

    2014-06-15

    As part of a larger study of mercury (Hg) biogeochemistry and bioaccumulation in agricultural (rice growing) and non-agricultural wetlands in California's Central Valley, USA, seasonal and spatial controls on methylmercury (MeHg) production were examined in surface sediment. Three types of shallowly-flooded agricultural wetlands (white rice, wild rice, and fallow fields) and two types of managed (non-agricultural) wetlands (permanently and seasonally flooded) were sampled monthly-to-seasonally. Dynamic seasonal changes in readily reducible 'reactive' mercury (Hg(II)R), Hg(II)-methylation rate constants (kmeth), and concentrations of electron acceptors (sulfate and ferric iron) and donors (acetate), were all observed in response to field management hydrology, whereas seasonal changes in these parameters were more muted in non-agricultural managed wetlands. Agricultural wetlands exhibited higher sediment MeHg concentrations than did non-agricultural wetlands, particularly during the fall through late-winter (post-harvest) period. Both sulfate- and iron-reducing bacteria have been implicated in MeHg production, and both were demonstrably active in all wetlands studied. Stoichiometric calculations suggest that iron-reducing bacteria dominated carbon flow in agricultural wetlands during the growing season. Sulfate-reducing bacteria were not stimulated by the addition of sulfate-based fertilizer to agricultural wetlands during the growing season, suggesting that labile organic matter, rather than sulfate, limited their activity in these wetlands. Along the continuum of sediment geochemical conditions observed, values of kmeth increased approximately 10,000-fold, whereas Hg(II)R decreased 100-fold. This suggests that, with respect to the often opposing trends of Hg(II)-methylating microbial activity and Hg(II) availability for methylation, microbial activity dominated the Hg(II)-methylation process, and that along this biogeochemical continuum, conditions that favored

  4. Sulfur, carbon, and oxygen isotope variations in submarine hydrothermal deposits of Guaymas Basin, Gulf of California, USA

    USGS Publications Warehouse

    Peter, J.M.; Shanks, Wayne C.

    1992-01-01

    Sulfur, carbon, and oxygen isotope values were measured in sulfide, sulfate, and carbonate from hydrothermal chimney, spire, and mound samples in the southern trough of Guaymas Basin, Gulf of California, USA. ??34S values of sulfides range from -3.7 to 4.5%. and indicate that sulfur originated from several sources: 1. (1) dissolution of 0??? sulfide contained within basaltic rocks, 2. (2) thermal reduction of seawater sulfate during sediment alteration reactions in feeder zones to give sulfide with positive ??34S, and 3. (3) entrainment or leaching of isotopically light (negative-??34S) bacteriogenic sulfide from sediments underlying the deposits. ??34S of barite and anhydrite indicate sulfur derivation mainly from unfractionated seawater sulfate, although some samples show evidence of sulfate reduction and sulfide oxidation reactions during mixing within chimneys. Oxygen isotope temperatures calculated for chimney calcites are in reasonable agreement with measured vent fluid temperatures and fluid inclusion trapping temperatures. Hydrothermal fluids that formed calcite-rich chimneys in the southern trough of Guaymas Basin were enriched in 18O with respect to seawater by about 2.4??? due to isotopic exchange with sedimentary and/or basaltic rocks. Carbon isotope values of calcite range from -9.6 to -14.0??? ??34CpDB, indicating that carbon was derived in approximately equal quantities from the dissolution of marine carbonate minerals and the oxidation of organic matter during migration of hydrothermal fluid through the underlying sediment column. Statistically significant positive, linear correlations of ??34S, ??34C, and ??18O of sulfides and calcites with geographic location within the southern trough of Guaymas Basin are best explained by variations in water/rock ( w r) ratios or sediment reactivity within subsurface alteration zones. Low w r ratios and the leaching of detrital carbonates and bacteriogenic sulfides at the southern vent sites result in relatively

  5. The effects of raking on sugar pine mortality following prescribed fire in Sequoia and Kings Canyon National Parks, California, USA

    USGS Publications Warehouse

    Nesmith, Jonathan C. B.; O'Hara, Kevin L.; van Mantgem, Phillip J.; de Valpine, Perry

    2010-01-01

    Prescribed fire is an important tool for fuel reduction, the control of competing vegetation, and forest restoration. The accumulated fuels associated with historical fire exclusion can cause undesirably high tree mortality rates following prescribed fires and wildfires. This is especially true for sugar pine (Pinus lambertiana Douglas), which is already negatively affected by the introduced pathogen white pine blister rust (Cronartium ribicola J.C. Fisch. ex Rabenh). We tested the efficacy of raking away fuels around the base of sugar pine to reduce mortality following prescribed fire in Sequoia and Kings Canyon national parks, California, USA. This study was conducted in three prescribed fires and included 457 trees, half of which had the fuels around their bases raked away to mineral soil to 0.5 m away from the stem. Fire effects were assessed and tree mortality was recorded for three years after prescribed fires. Overall, raking had no detectable effect on mortality: raked trees averaged 30% mortality compared to 36% for unraked trees. There was a significant effect, however, between the interaction of raking and average pre-treatment forest floor fuel depth: the predicted probability of survival of a 50 cm dbh tree was 0.94 vs. 0.96 when average pre-treatment fuel depth was 0 cm for a raked and unraked tree, respectively. When average pre-treatment forest floor fuel depth was 30 cm, the predicted probability of survival for a raked 50 cm dbh tree was 0.60 compared to only 0.07 for an unraked tree. Raking did not affect mortality when fire intensity, measured as percent crown volume scorched, was very low (0% scorch) or very high (>80% scorch), but the raking treatment significantly increased the proportion of trees that survived by 9.6% for trees that burned under moderate fire intensity (1% to 80% scorch). Raking significantly reduced the likelihood of bole charring and bark beetle activity three years post fire. Fuel depth and anticipated fire intensity need

  6. Anaerovirgula multivorans gen. nov., sp. nov., a Novel Spore-Forming, Alkaliphilic Anaerobe Isolated from Owens Lake, California, USA

    NASA Technical Reports Server (NTRS)

    Pikuta, Elena V.; Itoh, Takashi; Krader, Paul; Whitman, William B.; Hoover, Richard B.

    2006-01-01

    A novel, alkaliphilic, obligately anaerobic bacterium, strain SCAT, was isolated from mud sediments of a soda lake in California, USA. The rod-shaped cells were motile, Gram-positive, formed spores and were 0.4-0.5x2.5-5.0 micrometers in size. Growth occurred within the pH range 6.7-10.0 and was optimal at pH 8.5. The temperature range for growth was 10-45 degrees C, with optimal growth at 35 degrees C. NaCl was required for growth. Growth occurred at 0.5-9.0% (w/v) NaCl and was optimal at 1-2% (w/v). The novel isolate was a catalase-negative chemo-organoheterotroph that fermented sugars, proteolysis products, some organic and amino acids, glycerol, d-cellobiose and cellulose. It was also capable of growth by the Stickland reaction. Strain SCAT was sensitive to tetracycline, chloramphenicol, rifampicin and gentamicin, but it was resistant to ampicillin and kanamycin. The G+C content of the genomic DNA was 34.2 mol%. Major fatty acid components were C14:0, iso-C15:0, C16:1omega9c and C16:0. 16S rRNA gene sequence analysis of strain SCAT showed a similarity of approximately 97% with the type strains of Clostridium formicaceticum and Clostridium aceticum in clostridial cluster XI and a similarity of less than 94.2% to any other recognized Clostridium species and those of related genera in this cluster. Strain SCAT was clearly differentiated from C. formicaceticum and C. aceticum based on comparison of their phenotypic properties and fatty acid profiles, as well as low levels of DNA-DNA relatedness between strain SCAT and the type strains of these two species. Therefore, strain SCAT is considered to represent a novel species of a new genus, Anaerovirgula multivorans gen. nov., sp. nov., in clostridial cluster XI. The type strain is SCAT (=ATCC BAA-1084T=JCM 12857T=DSM 17722T=CIP 107910T).

  7. Physical, Nutrient, and Biological Measurements of Coastal Waters off Central California in November 2007

    DTIC Science & Technology

    2008-07-01

    Durazo Universidad Autonoma de Baja California Ensenada, Mexico Libe Washburn University of California Santa Barbara, CA Paul Choboter...CalPoly State University San Luis Obispo, CA Roger Hewitt NOAA La Jolla, CA Carmen G. Castro Consejo Superior de Investigaciones

  8. Contamination status and accumulation profiles of organotins in sea otters (Enhydra lutris) found dead along the coasts of California, Washington, Alaska (USA), and Kamchatka (Russia).

    PubMed

    Murata, Satoko; Takahashi, Shin; Agusa, Tetsuro; Thomas, Nancy J; Kannan, Kurunthachalam; Tanabe, Shinsuke

    2008-04-01

    Organotin compounds (OTs) including mono- to tri-butyltins, -phenyltins, and -octyltins were determined in the liver of adult sea otters (Enhydra lutris) found dead along the coasts of California, Washington, and Alaska in the USA and Kamchatka, Russia. Total concentrations of OTs in sea otters from California ranged from 34 to 4100ng/g on a wet weight basis. The order of concentrations of OTs in sea otters was total butyltins>total octyltins> or = total phenyltins. Elevated concentrations of butyltins (BTs) were found in some otters classified under 'infectious-disease' mortality category. Concentrations of BTs in few of these otters were close to or above the threshold levels for adverse health effects. Total butyltin concentrations decreased significantly in the livers of California sea otters since the 1990s. Based on the concentrations of organotins in sea otters collected from 1992 to 2002, the half-lives of tributyltin and total butyltins in sea otters were estimated to be approximately three years.

  9. Contamination status and accumulation profiles of organotins in sea otters (Enhydra lutris) found dead along the coasts of California, Washington, Alaska (USA), and Kamchatka (Russia)

    USGS Publications Warehouse

    Murata, S.; Takahashi, S.; Agusa, T.; Thomas, N.J.; Kannan, K.; Tanabe, S.

    2008-01-01

    Organotin compounds (OTs) including mono- to tri-butyltins, -phenyltins, and -octyltins were determined in the liver of adult sea otters (Enhydra lutris) found dead along the coasts of California, Washington, and Alaska in the USA and Kamchatka, Russia. Total concentrations of OTs in sea otters from California ranged from 34 to 4100 ng/g on a wet weight basis. The order of concentrations of OTs in sea otters was total butyltins ??? total octyltins ??? total phenyltins. Elevated concentrations of butyltins (BTs) were found in some otters classified under 'infectious-disease' mortality category. Concentrations of BTs in few of these otters were close to or above the threshold levels for adverse health effects. Total butyltin concentrations decreased significantly in the livers of California sea otters since the 1990s. Based on the concentrations of organotins in sea otters collected from 1992 to 2002, the half-lives of tributyltin and total butyltins in sea otters were estimated to be approximately three years. ?? 2008 Elsevier Ltd. All rights reserved.

  10. Paleomagnetic constraints on the timing and duration of latest Pleistocene to early Holocene eruptions at Mount Shasta volcano, California, USA

    NASA Astrophysics Data System (ADS)

    Gardner, C. A.; Champion, D. E.; Christiansen, R. L.; Calvert, A. T.; Mosbrucker, A. R.

    2013-12-01

    Mount Shasta in northern California, USA, has among the highest late Pleistocene to early Holocene eruptive rates in the Cascades arc (Hildreth, 2007, USGS Prof Paper 1744). Paleomagnetic data from over 50 sites help constrain the timing and durations of these events. In late glacial times, lithic pyroclastic flows of unknown volume and age swept down all flanks of the volcano, followed, after a period of quiescence, by Shasta's largest known explosive event-- the pumiceous Red Banks tephra fall and pyroclastic flows at ~11 ka. The Red Banks tephra fall was closely followed by growth of the Shastina and Black Butte edifices on the west side of the volcano with the volume of the Shastina deposits alone estimated to be about 30 km3. Since cessation of activity at Shastina and Black Butte, a series of lava domes and flows built the summit Hotlum cone and inundated the N and E flanks of the volcano. Paleomagnetic secular-variation data show that the events described above have well-grouped and distinct remanence directions suggesting that individual pulses of activity occurred within short time intervals (days to decades), with periods of quiescence between them lasting longer than the eruptive activity. The total interval of time suggested by the movement of the magnetic field from pre-Red Banks through Hotlum activity is likely within 5-10 kyr. The pre-Redbanks pyroclastic flows exposed on at least three flanks of the volcano have essentially the same paleomagnetic direction of ~ D=350°, I=60° with a site mean α95of 1.8° (7/7 sites). The Red Banks eruptive products have a more easterly and shallower (~ D=2°, I=53°) remanent direction. The prominent Shastina cone on the NW flank of the volcano produced lava flows to the NW and SW of the cone and an apron of pyroclastic material to the west. Shastina pyroclastic flows and lava flows have a similar direction of ~ D=8°, I=56 (α95 from 15 sites is 1.4°) suggesting that the Shastina eruptive period lasted a

  11. Soil geochemistry of Mother Lode-type gold deposits in the Hodson mining district, central California, U.S.A.

    USGS Publications Warehouse

    Chaffee, M.A.; Hill, R.H.

    1989-01-01

    The Hodson mining district is in the westernmost foothills of the Sierra Nevada in California, about 17 km west of the town of Angels Camp. This district is part of the West Gold Belt, which lies about 12-16 km west of, and generally parallel to, the better known Mother Lode Gold Belt in central California. The district produced several million dollars worth of Au between about 1890 and 1940. ?? 1989.

  12. Protocol, Engineering Research Center, University of California, Santa Barbara

    DTIC Science & Technology

    2005-12-01

    characteristics of the protocols (Suda). " Developed a natural language interface and voice-enabled applications for mobile wireless personal handheld...microsecond for a three-way replicated server. With an alternative rotating sequencer protocol, the latency is still about 400 microseconds for a three-way... sequence numbers, acknowledge messages already received, and retransmit messages for which acknowledgments are not received. Thus, the standby server

  13. A Two-Generation Study of Body Mass Index, Energy Balance and Specific Physical Activity of College Students and Their Respective Parents Living in the Same Household at Los Angeles, California, U.S.A.

    ERIC Educational Resources Information Center

    Liang, Ying; Lee, Judy; Tam, Chick F.; Bridges, Elizabeth; Keating, Xiaofen D.

    2007-01-01

    The purpose was to compare the differences in body mass index (BMI), energy balance (EB) and specific physical activity (SPA) between 30 CSULA college students (Y) and their respective parents (O) living in the same household at Los Angeles, California, U.S.A. Each student completed a 24-hour dietary record with SPA journal, and the same for…

  14. DEMOGRAPHY AND SPATIAL POPULATION STRUCTURE IN CALIFORNIA TIGER SALAMANDER

    EPA Science Inventory

    Although the causes of many amphibian declines remain mysterious, there is general agreement that human habitat alteration represents the greatest threat to amphibian populations. In January 2000 the US Fish and Wildlife Service proposed listing Santa Barbara County California Ti...

  15. Opportunity in our Ignorance: Urban Biodiversity Study Reveals 30 New Species and One New Nearctic Record for Megaselia (Diptera: Phoridae) in Los Angeles (California, USA).

    PubMed

    Hartop, Emily A; Brown, Brian V; Disney, R Henry L

    2015-04-02

    An urban biodiversity study sampling primarily from private backyards in Los Angeles, California (USA), reveals the presence of fifty-six species of Megaselia within the first few months of sampling. Thirty of these are described as new to science: M. armstrongorum, M. bradyi, M. brejchaorum, M. carthayensis, M. ciancii, M. creasoni, M. defibaughorum, M. donahuei, M. francoae, M. fujiokai, M. hardingorum, M. heini, M. hentschkeae, M. hoffmanorum, M. hoggorum, M. hoguei, M. isaacmajorum, M. kelleri, M. lombardorum, M. marquezi, M. mikejohnsoni, M. oxboroughae, M. pisanoi, M. renwickorum, M. rodriguezorum, M. sacatelensis, M. seaverorum, M. sidneyae, M. steptoeae, and M. wiegmanae. M. largifrontalis is newly reported from the Nearctic Region. The implications these findings have for future taxonomic work in Megaselia, particularly in urban areas, are discussed.

  16. The precarious persistence of the endangered Sierra Madre yellow-legged frog Rana muscosa in southern California, USA

    USGS Publications Warehouse

    Backlin, Adam R.; Hitchcock, Cynthia J.; Gallegos, Elizabeth A.; Yee, Julie L.; Fisher, Robert N.

    2015-01-01

    We conducted surveys for the Endangered Sierra Madre yellow-legged frog Rana muscosa throughout southern California to evaluate the current distribution and status of the species. Surveys were conducted during 2000–2009 at 150 unique streams and lakes within the San Gabriel, San Bernardino, San Jacinto, and Palomar mountains of southern California. Only nine small, geographically isolated populations were detected across the four mountain ranges, and all tested positive for the amphibian chytrid fungus Batrachochytrium dendrobatidis. Our data show that when R. muscosa is known to be present it is easily detectable (89%) in a single visit during the frog's active season. We estimate that only 166 adult frogs remained in the wild in 2009. Our research indicates that R. muscosa populations in southern California are threatened by natural and stochastic events and may become extirpated in the near future unless there is some intervention to save them.

  17. 77 FR 65621 - Security Zone; Cruise Ships, Santa Barbara Harbor, Santa Barbara, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-30

    ... waters from the surface to the sea floor within a 100-yard radius of any cruise ship located within 3... to the sea floor within a 100-yard radius of any cruise ship which is located within 3 nautical miles... Barbara Harbor within a 100-yard radius of cruise ships covered by this rule. This security...

  18. Relations of hydrogeologic factors, groundwater reduction-oxidation conditions, and temporal and spatial distributions of nitrate, Central-Eastside San Joaquin Valley, California, USA

    USGS Publications Warehouse

    Landon, M.K.; Green, C.T.; Belitz, K.; Singleton, M.J.; Esser, B.K.

    2011-01-01

    In a 2,700-km2 area in the eastern San Joaquin Valley, California (USA), data from multiple sources were used to determine interrelations among hydrogeologic factors, reduction-oxidation (redox) conditions, and temporal and spatial distributions of nitrate (NO3), a widely detected groundwater contaminant. Groundwater is predominantly modern, or mixtures of modern water, with detectable NO3 and oxic redox conditions, but some zones have anoxic or mixed redox conditions. Anoxic conditions were associated with long residence times that occurred near the valley trough and in areas of historical groundwater discharge with shallow depth to water. Anoxic conditions also were associated with interactions of shallow, modern groundwater with soils. NO3 concentrations were significantly lower in anoxic than oxic or mixed redox groundwater, primarily because residence times of anoxic waters exceed the duration of increased pumping and fertilizer use associated with modern agriculture. Effects of redox reactions on NO3 concentrations were relatively minor. Dissolved N2 gas data indicated that denitrification has eliminated gt;5 mg/L NO3-N in about 10% of 39 wells. Increasing NO3 concentrations over time were slightly less prevalent in anoxic than oxic or mixed redox groundwater. Spatial and temporal trends of NO3 are primarily controlled by water and NO3 fluxes of modern land use. ?? 2011 Springer-Verlag (outside the USA).

  19. Spatial patterns of atmospherically deposited organic contaminants at high elevation in the southern Sierra Nevada mountains, California, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Airborne contaminants in the Sierra Nevada mountains of California have been implicated as a factor adversely affecting biological resources like amphibians and fish, yet the distributions of contaminants within the mountains are poorly known, particularly at high elevation. we evaluated contaminan...

  20. Benthic macroinvertebrates as indicators of biological condition below hydropower dams on west slope Sierra Nevada streams, California, USA

    EPA Science Inventory

    Over 50 hydropower dams in California will undergo relicensing by the Federal Energy Regulatory Commission (FERC) in the next 15 years. An interpretive framework for biological data collected by relicensing studies is lacking. This study developed a multi-metric index of biotic...

  1. Quaternary tephrochronology and deposition in the subsurface Sacramento-San Joaquin Delta, California, U.S.A.

    USGS Publications Warehouse

    Maier, Katherine L.; Gatti, Emma; Wan, Elmira; Ponti, Daniel J.; Pagenkopp, Mark; Starratt, Scott W.; Olson, Holly A.; Tinsley, John

    2015-01-01

    We document characteristics of tephra, including facies and geochemistry, from 27 subsurface sites in the Sacramento-San Joaquin Delta, California, to obtain stratigraphic constraints in a complex setting. Analyzed discrete tephra deposits are correlative with: 1) an unnamed tephra from the Carlotta Formation near Ferndale, California, herein informally named the ash of Wildcat Grade (<~1.450 - >~0.780 Ma), 2) the Rockland ash bed (~0.575 Ma), 3) the Loleta ash bed (~0.390 Ma), and 4) a middle Pleistocene tephra resembling volcanic ash deposits at Tulelake, California, and Pringle Falls, Bend, and Summer Lake, Oregon, herein informally named the dacitic ash of Hood (<~0.211 to >~0.180 Ma, correlated age). All four tephra are derived from Cascades volcanic sources. The Rockland ash bed erupted from the southern Cascades near Lassen Peak, California, and occurs in deposits up to >7 m thick as observed in core samples taken from ~40 m depth below land surface. Tephra facies and tephra age constraints suggest rapid tephra deposition within fluvial channel and overbank settings, likely related to flood events shortly following the volcanic eruption. Such rapidly deposited tephra are important chronostratigraphic markers that suggest varying sediment accumulation rates (~0.07-0.29 m/1000 yr) in Quaternary deposits below the modern Sacramento-San Joaquin Delta. This study provides the first steps in developing a subsurface Quaternary stratigraphic framework necessary for future hazard assessment.

  2. Undoing Gender through Legislation and Schooling: The Case of AB 537 and AB 394 in California, USA

    ERIC Educational Resources Information Center

    Knotts, Greg

    2009-01-01

    This article investigates California laws AB 537: The Student Safety and Violence Prevention Act of 2000, and the recently enacted AB 394: Safe Place to Learn Act. Both demand that gender identity and sexual orientation be added to the lexicon of anti-harassment protection in public education. However, despite these progressive measures, schools…

  3. Accumulation pattern of organochlorine pesticides and polychlorinated biphenyls in sourthern sea otters (Enhydra lutris nereis) found stranded along coastal California, USA

    USGS Publications Warehouse

    Nakata, H.; Kannan, K.; Jing, L.; Thomas, N.J.; Tanabe, S.; Giesy, J.P.

    1998-01-01

    Concentrations of PCBs, DDTs (p,p'-DDE, p,p'-DDD and p,p'-DDT), HCHs (α-, β-, γ-isomers), chlordanes (trans-chlordane, cis-chlordane, trans-nonachlor, cis-nonachlor and oxychlordane) and HCB (hexachlorobenzene were measured in liver, kidney and brain tissues of adult southern sea otters (Enhydra lutris nereis) found stranded along coastal California, USA, during 1992–96. The contamination pattern of organochlorines in sea otters from several locations was in the order of DDTs > PCBs > > CHLs > HCHs > > HCB, whereas those from Monterey Harbor contained greater concentrations of PCBs than of DDTs. Hepatic concentrations of PCBs and DDTs were in the ranges of 58–8700 and 280–5900 ng/g, wet weight, respectively, which varied depending on the geographic location. Sea otters collected from Monterey Harbor contained the greatest concentrations of PCBs and DDTs. In general, accumulation of DDTs, CHLs and PCBs was greater in kidney than in liver, whereas that of HCHs was similar in both the tissues. The gender difference in organochlorine concentrations was less than those reported in cetaceans. The composition of DDTs, HCHs and CHLs compounds in sea otter tissues indicated no recent inputs of these compounds in coastal California. Sea otters that died from infectious diseases, neoplasia and emaciation contained higher concentrations of DDTs than those that died from trauma.

  4. Harry Beal Torrey (1873-1970) of California, USA, and his research on hydroids and other coelenterates.

    PubMed

    Calder, Dale R

    2013-01-10

    Harry Beal Torrey was born on 22 May 1873 in Boston, Massachusetts. Two years later his family moved to Oakland, California. Torrey earned B.S. and M.S. degrees in zoology from the University of California, Berkeley, in 1895 and 1898 respectively, a Ph.D. in zoology from Columbia University in 1903, and an M.D. from the Medical College of Cornell University in 1927. He began his academic career as a marine biologist, investigating taxonomy, reproduction, morphology, development, regeneration, and behaviour of cnidarians of the west coast of the United States, but his research interests soon shifted to experimental biology and endocrinology. He eventually entered the field of medicine, specializing in public health, and served as a physician and hospital administrator. Torrey held academic positions at the University of California, Berkeley (1895-1912), the Marine Biological Association of San Diego (1903-1912), Reed College (1912-1920), the University of Oregon (1920-1926), and Stanford University (1928-1938). Following retirement from academia, he served as Director of the Children's Hospital of the East Bay, Oakland, California, from 1938 to 1942. In retirement, he continued an association with the University of California at Berkeley, near his home. Of 84 publications by him listed herein, 31 dealt with coelenterates. This paper focuses on his early research on coelenterate biology, and especially his contributions to taxonomy of hydroids. He was author or coauthor of six genera and 48 species-group taxa of Cnidaria, and he also described one new species each of Ctenophora and Phoronida. Although he abandoned systematic work early in his career, his most widely cited publication is a taxonomic monograph on hydroids of the west coast of North America, published in 1902. He died, at age 97, on 9 September 1970.

  5. Environmental Assessment for the California Space Center at Vandenberg Air Force Base, California

    DTIC Science & Technology

    2010-04-08

    Cultural Resources Inventory, Vandenberg Air Force Base, Santa Barbara County, California Hodges et al. (2000) 2000-04 Archaeological Survey of the...Review Laura Ornelaz, Attorney Advisor, 30 SW/JA, VAFB Nick Pelster, Technical Director, California Space Authority Roger Root, U.S. Fish and Wildlife...the terrestrial natural communities of California. Nongame Heritage Program. California Department of Fish and Game, Sacramento. Hodges , C.M., C.G

  6. The Tulare Lake Project: A 35,000-year record of lake level constraining precipitation and stream discharge from the southern Sierra Nevada of California, USA

    NASA Astrophysics Data System (ADS)

    Negrini, R. M.

    2015-12-01

    Building upon earlier works by Harding (1949), Atwater et al. (1986) and Davis (1999), research centered at CSU Bakersfield over the past 15 years has generated a high resolution paleoclimate history with water resource implications for one of the world's great agricultural centers, the San Joaquin Valley of California. Lake level is based upon aerial mapping of geomorphological features (e.g., sand spits and shorelines), lithologic features exposed in trenches from opposite sides of the lake basin (e.g., marsh deposits), and proxy data from core (e.g., clay %). Age control was provided by radiocarbon dating of charcoal, mussel shells, and bulk organic matter and by paleomagnetic secular variation dating. From oldest to youngest, highlights include: 1. millennial-scale variations at the base of the record, 2. evidence for avulsion of the Kings River into Tulare Lake at or near the time of maximum glaciation in the Sierra Nevada as predicted by Weissman et al. (2005), 3. lake-level changes during the early and middle Holocene that vary in tune with eastern Pacific sea-surface temperatures from marine core records. This includes an unusually wet period starting at 12,500 cal B.P. followed by a dramatic, rapid drop in lake level at 7,500 cal B.P. Evidence for the former feature includes geochemical (leaf wax n-alkane markers for grass) and petrographic (grass phytolith) data. The latter feature represents an abrupt decrease in Sierran Stream discharge equal to several millions of acre-ft/yr. 4. A centuries-long increase in lake level commencing in the 13th or 14th century based on both lake-level reconstructions from the LBDA of Cook et al. (2010) and dated fine-grained sediments exposed in high-elevation trenches (Negrini et al., 2006), 5. A flood deposit identified in the uppermost sediments exposed in the southeastern edge of the lake that has a radiocarbon age consistent with that of an early 17th century flood found in the sediments of the Santa Barbara Channel

  7. Mentors, Muses, and Mutuality: Honoring Barbara Snell Dohrenwend

    ERIC Educational Resources Information Center

    Mulvey, Anne

    2012-01-01

    I describe feminist community psychology principles that have the potential to expand and enrich mentoring and that honor Barbara Snell Dohrenwend, a leader who contributed to the research, theory, and profession of community psychology. I reflect on the affect that Barbara Dohrenwend had on life and on the development of feminist community…

  8. International Conference on Vibrations at Surfaces (3rd) Held at Asilomar, California (USA) September 1-4, 1982.

    DTIC Science & Technology

    1982-09-04

    Northwestern University, Evanston, Illinois, "Laser-Induced Thermal Desorption of CO from Clean Polycrystalline Copper : Time-of-Flight and Surface Diffusion...Scattering (SERS) from Silver, Copper , and Gold Films in UHV: Excitation Spectra". 10:04 a.m. D. A. Weitz and S. Garoff, Exxon Research and Engineering...95193, USA The chemisorption of oxygen on Lithium, Aluminum, and Copper surfaces has been investigated using the ab initio Hartree-Fock cluster model

  9. Undoing Gender Through Legislation and Schooling: the Case of AB 537 and AB 394 IN California, USA

    NASA Astrophysics Data System (ADS)

    Knotts, Greg

    2009-11-01

    This article investigates California laws AB 537: The Student Safety and Violence Prevention Act of 2000, and the recently enacted AB 394: Safe Place to Learn Act. Both demand that gender identity and sexual orientation be added to the lexicon of anti-harassment protection in public education. However, despite these progressive measures, schools have an unconscious acceptance of heteronormativity and gendered norms, which undermines both the spirit and language of these laws. This paper examines how California schools can both change standard practices and realise the transformative social change that laws like AB 537 and AB 394 can instigate. I assert that the systemic implementation of these laws, through the adoption, enforcement and evaluation of existing AB 537 Task Force Recommendations, is necessary for their success. My second assertion is that AB 537 and AB 394 have the potential to change and reconstitute gender-based and heteronormative standards at school sites.

  10. Emergency response and field observation activities of geoscientists in California (USA) during the September 29, 2009, Samoa Tsunami

    NASA Astrophysics Data System (ADS)

    Wilson, Rick I.; Dengler, Lori A.; Goltz, James D.; Legg, Mark R.; Miller, Kevin M.; Ritchie, Andy; Whitmore, Paul M.

    2011-07-01

    State geoscientists (geologists, geophysicists, seismologists, and engineers) in California work closely with federal, state and local government emergency managers to help prepare coastal communities for potential impacts from a tsunami before, during, and after an event. For teletsunamis, as scientific information (forecast model wave heights, first-wave arrival times, etc.) from NOAA's West Coast and Alaska Tsunami Warning Center is made available, federal- and state-level emergency managers must help convey this information in a concise, comprehensible and timely manner to local officials who ultimately determine the appropriate response activities for their jurisdictions. During the September 29, 2009 Tsunami Advisory for California, government geoscientists assisted the California Emergency Management Agency by providing technical assistance during teleconference meetings with NOAA and other state and local emergency managers prior to the arrival of the tsunami. This technical assistance included background information on anticipated tidal conditions when the tsunami was set to arrive, wave height estimates from state-modeled scenarios for areas not covered by NOAA's forecast models, and clarifying which regions of the state were at greatest risk. Over the last year, state geoscientists have started to provide additional assistance: 1) working closely with NOAA to simplify their tsunami alert messaging and expand their forecast modeling coverage; 2) creating "playbooks" containing information from existing tsunami scenarios for local emergency managers to reference during an event; and, 3) developing a state-level information "clearinghouse" and pre-tsunami field response team to assist local officials as well as observe and report tsunami effects. Activities of geoscientists were expanded during the more recent Tsunami Advisory on February 27, 2010, including deploying a geologist from the California Geological Survey as a field observer who provided

  11. Coccidioidomycosis and other systemic mycoses of marine mammals stranding along the central California, USA coast: 1998-2012.

    PubMed

    Huckabone, Sara E; Gulland, Frances M D; Johnson, Suzanne M; Colegrove, Kathleen M; Dodd, Erin M; Pappagianis, Demosthenes; Dunkin, Robin C; Casper, David; Carlson, Erin L; Sykes, Jane E; Meyer, Weiland; Miller, Melissa A

    2015-04-01

    A wide range of systemic mycoses have been reported from captive and wild marine mammals from North America. Examples include regionally endemic pathogens such as Coccidioides and Blastomyces spp., and novel pathogens like Cryptococcus gattii, which appear may have been introduced to North America by humans. Stranding and necropsy data were analyzed from three marine mammal stranding and response facilities on the central California coast to assess the prevalence, host demographics, and lesion distribution of systemic mycoses affecting locally endemic marine mammals. Between 1 January 1998 and 30 June 2012, >7,000 stranded marine mammals were necropsied at the three facilities. Necropsy and histopathology records were reviewed to identify cases of locally invasive or systemic mycoses and determine the nature and distribution of fungal lesions. Forty-one animals (0.6%) exhibited cytological, culture- or histologically confirmed locally invasive or systemic mycoses: 36 had coccidioidomycosis, two had zygomycosis, two had cryptococcosis, and one was systemically infected with Scedosporium apiospermum (an Ascomycota). Infected animals included 18 California sea lions (Zalophus californianus), 20 southern sea otters (Enhydra lutris nereis), two Pacific harbor seals (Phoca vitulina richardsi), one Dall's porpoise (Phocoenoides dalli), and one northern elephant seal (Mirounga angustirostris). Coccidioidomycosis was reported from 15 sea lions, 20 sea otters, and one harbor seal, confirming that Coccidioides spp. is the most common pathogen causing systemic mycosis in marine mammals stranding along the central California coast. We also report the first confirmation of C. gattii infection in a wild marine mammal from California and the first report of coccidioidomycosis in a wild harbor seal. Awareness of these pathogenic fungi during clinical care and postmortem examination is an important part of marine mammal population health surveillance and human health protection

  12. Placing the 2012-2015 California-Nevada drought into a paleoclimatic context: Insights from Walker Lake, California-Nevada, USA

    NASA Astrophysics Data System (ADS)

    Hatchett, Benjamin J.; Boyle, Douglas P.; Putnam, Aaron E.; Bassett, Scott D.

    2015-10-01

    Assessing regional hydrologic responses to past climate changes can offer a guide for how water resources might respond to ongoing and future climate change. Here we employed a coupled water balance and lake evaporation model to examine Walker Lake behaviors during the Medieval Climate Anomaly (MCA), a time of documented hydroclimatic extremes. Together, a 14C-based shoreline elevation chronology, submerged subfossil tree stumps in the West Walker River, and regional paleoproxy evidence indicate a ~50 year pluvial episode that bridged two 140+ year droughts. We developed estimates of MCA climates to examine the transient lake behavior and evaluate watershed responses to climate change. Our findings suggest the importance of decadal climate persistence to elicit large lake-level fluctuations. We also simulated the current 2012-2015 California-Nevada drought and found that the current drought exceeds MCA droughts in mean severity but not duration.

  13. 3D point cloud data from laser scanning along the 2014 South Napa Earthquake surface rupture, California, USA

    USGS Publications Warehouse

    DeLong, Stephen B.

    2016-01-01

    Point cloud data collected along a 500 meter portion of the 2014 South Napa Earthquake surface rupture near Cuttings Wharf Road, Napa, CA, USA. The data include 7 point cloud files (.laz). The files are named with the location and date of collection and either ALSM for airborne laser scanner data or TLS for terrestrial laser scanner data. The ALSM data re previously released but are included here because they have been precisely aligned with the TLS data as described in the processing section of this metadata. 

  14. A re-evaluation of the size of the white shark (Carcharodon carcharias) population off California, USA.

    PubMed

    Burgess, George H; Bruce, Barry D; Cailliet, Gregor M; Goldman, Kenneth J; Grubbs, R Dean; Lowe, Christopher G; MacNeil, M Aaron; Mollet, Henry F; Weng, Kevin C; O'Sullivan, John B

    2014-01-01

    White sharks are highly migratory and segregate by sex, age and size. Unlike marine mammals, they neither surface to breathe nor frequent haul-out sites, hindering generation of abundance data required to estimate population size. A recent tag-recapture study used photographic identifications of white sharks at two aggregation sites to estimate abundance in "central California" at 219 mature and sub-adult individuals. They concluded this represented approximately one-half of the total abundance of mature and sub-adult sharks in the entire eastern North Pacific Ocean (ENP). This low estimate generated great concern within the conservation community, prompting petitions for governmental endangered species designations. We critically examine that study and find violations of model assumptions that, when considered in total, lead to population underestimates. We also use a Bayesian mixture model to demonstrate that the inclusion of transient sharks, characteristic of white shark aggregation sites, would substantially increase abundance estimates for the adults and sub-adults in the surveyed sub-population. Using a dataset obtained from the same sampling locations and widely accepted demographic methodology, our analysis indicates a minimum all-life stages population size of >2000 individuals in the California subpopulation is required to account for the number and size range of individual sharks observed at the two sampled sites. Even accounting for methodological and conceptual biases, an extrapolation of these data to estimate the white shark population size throughout the ENP is inappropriate. The true ENP white shark population size is likely several-fold greater as both our study and the original published estimate exclude non-aggregating sharks and those that independently aggregate at other important ENP sites. Accurately estimating the central California and ENP white shark population size requires methodologies that account for biases introduced by sampling a

  15. Correlation of the Peach Springs Tuff, a large-volume Miocene ignimbrite sheet in California and Arizona ( USA).

    USGS Publications Warehouse

    Glazner, A.F.; Nielson, J.E.; Howard, K.A.; Miller, D.M.

    1986-01-01

    The Peach Springs Tuff is a distinctive early Miocene ignimbrite deposit that was first recognized in western Arizona. Recent field studies and phenocryst analyses indicate that adjacent outcrops of similar tuff in the central and eastern Mojave Desert may be correlative. This proposed correlation implies that outcrops of the tuff are scattered over an area of at least 35 000 km2 from the western Colorado Plateau to Barstow, California, and that the erupted volume, allowing for posteruption crustal extension, was at least several hundred cubic kilometres. Thus, the Peach Springs Tuff may be a regional stratigraphic marker, useful for determining regional paleogeography and the time and extent of Tertiary crustal extension. -Authors

  16. Anomalomermis ephemerophagis n. g., n. sp. (Nematoda: Mermithidae) parasitic in the mayfly Ephemerella maculata Traver (Ephermeroptera: Ephermerellidae) in California, USA.

    PubMed

    Poinar, George; Walder, Larissa; Uno, Hiromi

    2015-03-01

    A new nematode, Anomalomermis ephemerophagis n. g., n. sp. (Nematoda: Mermithidae) is described from the mayfly Ephemerella maculata Traver (Ephermeroptera: Ephermerellidae) in California. The new species is characterised by six cephalic papillae and four additional disk papillae located on the head between the cephalic papillae and stoma. Additional diagnostic characters are: a terminal mouth opening; absence of X-fibers in the cuticle of both postparasitic juveniles and adults; paired, curved, medium-sized spicules; a straight barrow-shaped vagina and large eggs. Two infectious agents were present in some specimens. This is the first description of an adult nematode from a mayfly.

  17. Factors affecting plant diversity during post-fire recovery and succession of mediterranean-climate shrublands in California, USA

    USGS Publications Warehouse

    Keeley, J.E.; Fotheringham, C.J.; Baer-Keeley, M.

    2005-01-01

    Plant community diversity, measured as species richness, is typically highest in the early post-fire years in California shrublands. However, this generalization is overly simplistic and the present study demonstrates that diversity is determined by a complex of temporal and spatial effects. Ninety sites distributed across southern California were studied for 5 years after a series of fires. Characteristics of the disturbance event, in this case fire severity, can alter post-fire diversity, both decreasing and increasing diversity, depending on life form. Spatial variability in resource availability is an important factor explaining patterns of diversity, and there is a complex interaction between landscape features and life form. Temporal variability in resource availability affects diversity, and the diversity peak in the immediate post-fire year (or two) appears to be driven by factors different from subsequent diversity peaks. Early post-fire diversity is influenced by life-history specialization, illustrated by species that spend the bulk of their life cycle as a dormant seed bank, which is then triggered to germinate by fire. Resource fluctuations, precipitation in particular, may be associated with subsequent post-fire diversity peaks. These later peaks in diversity comprise a flora that is compositionally different from the immediate post-fire flora, and their presence may be due to mass effects from population expansion of local populations in adjacent burned areas. ?? 2005 Blackwell Publishing Ltd.

  18. Regional Evaluation of Groundwater Age Distributions Using Lumped Parameter Models with Large, Sparse Datasets: Example from the Central Valley, California, USA

    NASA Astrophysics Data System (ADS)

    Jurgens, B. C.; Bohlke, J. K.; Voss, S.; Fram, M. S.; Esser, B.

    2015-12-01

    Tracer-based, lumped parameter models (LPMs) are an appealing way to estimate the distribution of age for groundwater because the cost of sampling wells is often less than building numerical groundwater flow models sufficiently complex to provide groundwater age distributions. In practice, however, tracer datasets are often incomplete because of anthropogenic or terrigenic contamination of tracers, or analytical limitations. While age interpretations using such datsets can have large uncertainties, it may still be possible to identify key parts of the age distribution if LPMs are carefully chosen to match hydrogeologic conceptualization and the degree of age mixing is reasonably estimated. We developed a systematic approach for evaluating groundwater age distributions using LPMs with a large but incomplete set of tracer data (3H, 3Hetrit, 14C, and CFCs) from 535 wells, mostly used for public supply, in the Central Valley, California, USA that were sampled by the USGS for the California State Water Resources Control Board Groundwater Ambient Monitoring and Assessment or the USGS National Water Quality Assessment Programs. In addition to mean ages, LPMs gave estimates of unsaturated zone travel times, recharge rates for pre- and post-development groundwater, the degree of age mixing in wells, proportion of young water (<60 yrs), and the depth of the boundary between post-development and predevelopment groundwater throughout the Central Valley. Age interpretations were evaluated by comparing past nitrate trends with LPM predicted trends, and whether the presence or absence of anthropogenic organic compounds was consistent with model results. This study illustrates a practical approach for assessing groundwater age information at a large scale to reveal important characteristics about the age structure of a major aquifer, and of the water supplies being derived from it.

  19. Natural recharge estimation and uncertainty analysis of an adjudicated groundwater basin using a regional-scale flow and subsidence model (Antelope Valley, California, USA)

    USGS Publications Warehouse

    Siade, Adam J.; Nishikawa, Tracy; Martin, Peter

    2015-01-01

    Groundwater has provided 50–90 % of the total water supply in Antelope Valley, California (USA). The associated groundwater-level declines have led the Los Angeles County Superior Court of California to recently rule that the Antelope Valley groundwater basin is in overdraft, i.e., annual pumpage exceeds annual recharge. Natural recharge consists primarily of mountain-front recharge and is an important component of the total groundwater budget in Antelope Valley. Therefore, natural recharge plays a major role in the Court’s decision. The exact quantity and distribution of natural recharge is uncertain, with total estimates from previous studies ranging from 37 to 200 gigaliters per year (GL/year). In order to better understand the uncertainty associated with natural recharge and to provide a tool for groundwater management, a numerical model of groundwater flow and land subsidence was developed. The transient model was calibrated using PEST with water-level and subsidence data; prior information was incorporated through the use of Tikhonov regularization. The calibrated estimate of natural recharge was 36 GL/year, which is appreciably less than the value used by the court (74 GL/year). The effect of parameter uncertainty on the estimation of natural recharge was addressed using the Null-Space Monte Carlo method. A Pareto trade-off method was also used to portray the reasonableness of larger natural recharge rates. The reasonableness of the 74 GL/year value and the effect of uncertain pumpage rates were also evaluated. The uncertainty analyses indicate that the total natural recharge likely ranges between 34.5 and 54.3 GL/year.

  20. Validation and Application of PHYDOTax In The Santa Barbara Channel

    NASA Astrophysics Data System (ADS)

    Schafer, C. B.; Palacios, S. L.; Broughton, J.; Kudela, R. M.

    2013-12-01

    Phytoplankton Functional Types(PFTs) are conceptual groupings of phytoplankton based on physical or functional characteristics. Understanding phytoplankton is essential in our study of how ecosystems function and in monitoring carbon flow. PHYDOTax is a PFT algorithm that discriminates taxon-specific biomass in images from airborne and spaceborne hyperspectral sensors. The PHYDOTax algorithm uses a spectral library and an inverse matrix approach to deconvolve pure phytoplankton spectral end-members from spectra of natural waters. The spectral library used in development was created from phytoplankton taxa found in Monterey Bay, CA and the California Current System (CCS). PHYDOTax has only been validated in Monterey Bay and for only one airborne sensor, Spectroscopic Aerial Mapping System with On-board Navigation (SAMSON). The objectives of this research were to apply PHYDOTax to a different region of the CCS, Santa Barbara Channel (SBC), and to test the usability of PHYDOTax with a different airborne imager, Airborne Visible/Infrared Imaging Spectrometer (AVIRIS). PHYDOTax was modified to accommodate the reduced spectral resolution of AVIRIS, which has fewer wavelengths than the SAMSON imagery that was used to validate the model for Monterey Bay. PHYDOTax's predictions were consistent with cell-count data from whole water samples on June 5, 2013, courtesy of the Plumes and Blooms Cruise (UCSB). PHYDOTax's ability to perform in another area of the CCS shows promise that it may be accurately applied to the west coast of the US. PHYDOTax's ability to perform with lower spectral resolution imagery, suggests that it may it may be robust enough to be down-sampled to multi-spectral resolution inputs. This opens the possibility of applying PHYDOTax to historical (SeaWiFS, MODIS, MERIS), existing (VIIRS, HICO), and future (PACE, GEO-CAPE) sensors to describe temporal trends in phytoplankton distribution and carbon flow in the ocean and to build continuity among the sensor

  1. Risk factors associated with clinic visits during the 1999 forest fires near the Hoopa Valley Indian Reservation, California, USA.

    PubMed

    Lee, Tze-San; Falter, Kenneth; Meyer, Pamela; Mott, Joshua; Gwynn, Charon

    2009-10-01

    Forest fires burned near the Hoopa Valley Indian Reservation in northern California from late August until early November in 1999. The fires generated particulate matter reaching hazardous levels. We assessed the relationship between patients seeking care for six health conditions and PM(10) exposure levels during the 1999 fires and during the corresponding period in 1998 when there were no fires. Multivariate logistic regression analysis indicated that daily PM(10) levels in 1999 were significant predictors for patients seeking care for asthma, coronary artery disease and headache after controlling for potential risk factors. Stratified multivariate logistic regression models indicated that daily PM(10) levels in 1999 were significant predictors for patients seeking care for circulatory illness among residents of nearby communities and new patients, and for respiratory illness among residents of Hoopa and those of nearby communities.

  2. A report from the American College of Rheumatology 2013 Meeting (October 26-30, 2013 - San Diego, California, USA).

    PubMed

    Rabasseda, X

    2013-11-01

    The American College of Rheumatology annual meeting opened in San Diego, California, with a poster session in which prominent clinical and preclinical research into experimental and putative novel therapies for rheumatoid arthritis and other inflammatory conditions were discussed. The meeting continued through 2 more days of poster presentations and 4 days of very active oral sessions, in which information was discussed on therapeutics and candidate drugs for managing rheumatological diseases ranging from rheumatoid arthritis, osteoarthritis and systemic lupus erythematosus to many other conditions frequently seen in the rheumatology ward. The following report summarizes a selection of oral and poster presentations that reflect the state of the art of current rheumatology pharmacotherapy and what is arising as novel investigational therapy.

  3. Detection of a locked zone at depth on the Parkfield, California, segment of the San Andreas fault ( USA).

    USGS Publications Warehouse

    Harris, R.A.; Segall, P.

    1987-01-01

    The Parkfield, California, segment of the San Andreas fault is transitional in character between the creeping segment of the fault to the NW and the locked Carrizo Plain segment to the SE. The rate of shallow fault slip decreases from 25-30 mm/yr NW of the epicenter of the 1966 Parkfield earthquake to zero at the SE end of the 1966 rupture zone. Data from a network of trilateration lines spanning the San Andreas fault near Parkfield and extending to the Pacific coast near San Luis Obispo shed light on the rate of fault slip at depth since the 1966 earthquake. In this study, average rates of line length change and shallow fault slip were inverted to determine the slip rate at depth on the Parkfield fault segment. -from Authors

  4. A Re-Evaluation of the Size of the White Shark (Carcharodon carcharias) Population off California, USA

    PubMed Central

    Burgess, George H.; Bruce, Barry D.; Cailliet, Gregor M.; Goldman, Kenneth J.; Grubbs, R. Dean; Lowe, Christopher G.; MacNeil, M. Aaron; Mollet, Henry F.; Weng, Kevin C.; O'Sullivan, John B.

    2014-01-01

    White sharks are highly migratory and segregate by sex, age and size. Unlike marine mammals, they neither surface to breathe nor frequent haul-out sites, hindering generation of abundance data required to estimate population size. A recent tag-recapture study used photographic identifications of white sharks at two aggregation sites to estimate abundance in “central California” at 219 mature and sub-adult individuals. They concluded this represented approximately one-half of the total abundance of mature and sub-adult sharks in the entire eastern North Pacific Ocean (ENP). This low estimate generated great concern within the conservation community, prompting petitions for governmental endangered species designations. We critically examine that study and find violations of model assumptions that, when considered in total, lead to population underestimates. We also use a Bayesian mixture model to demonstrate that the inclusion of transient sharks, characteristic of white shark aggregation sites, would substantially increase abundance estimates for the adults and sub-adults in the surveyed sub-population. Using a dataset obtained from the same sampling locations and widely accepted demographic methodology, our analysis indicates a minimum all-life stages population size of >2000 individuals in the California subpopulation is required to account for the number and size range of individual sharks observed at the two sampled sites. Even accounting for methodological and conceptual biases, an extrapolation of these data to estimate the white shark population size throughout the ENP is inappropriate. The true ENP white shark population size is likely several-fold greater as both our study and the original published estimate exclude non-aggregating sharks and those that independently aggregate at other important ENP sites. Accurately estimating the central California and ENP white shark population size requires methodologies that account for biases introduced by

  5. ECOLOGIC DRIVERS AND POPULATION IMPACTS OF AVIAN TRICHOMONOSIS MORTALITY EVENTS IN BAND-TAILED PIGEONS (PATAGIOENAS FASCIATA) IN CALIFORNIA, USA.

    PubMed

    Rogers, Krysta H; Girard, Yvette A; Koenig, Walter D; Johnson, Christine K

    2016-07-01

    :   Avian trichomonosis, a disease typically caused by the protozoan parasite Trichomonas gallinae , is a well recognized cause of death in many avian species. In California, US, trichomonosis has caused periodic epidemics in Pacific Coast Band-tailed Pigeons ( Patagioenas fasciata monilis). We summarize reported mortality events and investigate ecologic drivers and population impacts associated with epidemic mortality due to trichomonosis in Band-tailed Pigeons. Between 1945 and 2014, 59 mortality events involving Band-tailed Pigeons were reported in California with the number of reported events increasing over time. Estimated mortality for these events was variable, ranging between 10 and 10,000 pigeons. Events were most-frequently reported in Monterey (19%; 11/59) and San Luis Obispo (8%; 5/59) counties. Events often started in January (32%; 9/28) and February (50%; 14/28) and lasted 5-68 d. Impacts of mortality events on pigeon populations were indicated by Breeding Bird Survey and Christmas Bird Count abundance indices, which showed a decline in outbreak years compared to nonoutbreak years. Environmental conditions most associated with outbreak years included higher average temperatures between January and March, the period most associated with mortality events, and lower average precipitation in December just prior to mortality events. In Monterey County, events tended to occur in winters following higher acorn production of coast live oaks ( Quercus agrifolia ) in the fall. Weather and food abundance could be related to increased transmission or enhanced viability of Trichomonas spp. Although estimated mortality due to avian trichomonosis was highly variable across years, cumulative losses were substantial and likely to have a negative impact on population size.

  6. Demography and movement patterns of leopard sharks (Triakis semifasciata) aggregating near the head of a submarine canyon along the open coast of southern California, USA

    USGS Publications Warehouse

    Nosal, D.C.; Cartamil, D.C.; Long, J.W.; Luhrmann, M.; Wegner, N.C.; Graham, J.B.

    2013-01-01

    The demography, spatial distribution, and movement patterns of leopard sharks (Triakis semifasciata) aggregating near the head of a submarine canyon in La Jolla, California, USA, were investigated to resolve the causal explanations for this and similar shark aggregations. All sharks sampled from the aggregation site (n=140) were sexually mature and 97.1 % were female. Aerial photographs taken during tethered balloon surveys revealed high densities of milling sharks of up to 5470 sharks ha-1. Eight sharks were each tagged with a continuous acoustic transmitter and manually tracked without interruption for up to 48 h. Sharks exhibited strong site-fidelity and were generally confined to a divergence (shadow) zone of low wave energy, which results from wave refraction over the steep bathymetric contours of the submarine canyon. Within this divergence zone, the movements of sharks were strongly localized over the seismically active Rose Canyon Fault. Tracked sharks spent most of their time in shallow water (≤2 m for 71.0 % and ≤10 m for 95.9 % of time), with some dispersing to deeper (max: 53.9 m) and cooler (min: 12.7 °C) water after sunset, subsequently returning by sunrise. These findings suggest multiple functions of this aggregation and that the mechanism controlling its formation, maintenance, and dissolution is complex and rooted in the sharks' variable response to numerous confounding environmental factors.

  7. High abundances of potentially active ammonia-oxidizing bacteria and archaea in oligotrophic, high-altitude lakes of the Sierra Nevada, California, USA.

    PubMed

    Hayden, Curtis J; Beman, J Michael

    2014-01-01

    Nitrification plays a central role in the nitrogen cycle by determining the oxidation state of nitrogen and its subsequent bioavailability and cycling. However, relatively little is known about the underlying ecology of the microbial communities that carry out nitrification in freshwater ecosystems--and particularly within high-altitude oligotrophic lakes, where nitrogen is frequently a limiting nutrient. We quantified ammonia-oxidizing archaea (AOA) and bacteria (AOB) in 9 high-altitude lakes (2289-3160 m) in the Sierra Nevada, California, USA, in relation to spatial and biogeochemical data. Based on their ammonia monooxygenase (amoA) genes, AOB and AOA were frequently detected. AOB were present in 88% of samples and were more abundant than AOA in all samples. Both groups showed >100 fold variation in abundance between different lakes, and were also variable through time within individual lakes. Nutrient concentrations (ammonium, nitrite, nitrate, and phosphate) were generally low but also varied across and within lakes, suggestive of active internal nutrient cycling; AOB abundance was significantly correlated with phosphate (r(2) = 0.32, p<0.1), whereas AOA abundance was inversely correlated with lake elevation (r(2) = 0.43, p<0.05). We also measured low rates of ammonia oxidation--indicating that AOB, AOA, or both, may be biogeochemically active in these oligotrophic ecosystems. Our data indicate that dynamic populations of AOB and AOA are found in oligotrophic, high-altitude, freshwater lakes.

  8. Black bear (Ursus americanus Pallas) feeding damage across timber harvest edges in northern California coast redwood (Sequoia sempervirens[D. Don] Endl.) forests, USA

    USGS Publications Warehouse

    Russell, W.H.; Carnell, K.; McBride, J.R.

    2001-01-01

    Feeding damage to trees by black bears (Ursus americanus Pallas) was recorded in proximity to timber harvest edges in harvested and old-growth stands of coast redwood (Sequoia sempervirens [D. Don] Endl.) in northern California, USA. Bears exhibited distinct preference in their feeding patterns related to stand structure and composition and to distance from the timber-harvest edge. Most damage was recorded within regenerating stands. Regression analysis indicated that density of damaged trees was negatively correlated with distance from timber harvest edges within old-growth stands. A significant negative correlation was also found between the density of trees damaged by bears and habitat diversity (H') as measured by the Shannon diversity index. In addition, bears exhibited preference for pole-size trees (dbh = 10-50 cm) over all other size classes, and coast redwood over other species. In general, damage by bears appeared to act as a natural thinning agent in even-aged stands. No damage was recorded in old-growth stands except in close proximity to the timber-harvest edge where subcanopy recruitment was high.

  9. Structural characterization of the fracture systems in the porcelanites: Comparing data from the Monterey Formation in California USA and the Sap Bon Formation in Central Thailand

    NASA Astrophysics Data System (ADS)

    Kanjanapayont, Pitsanupong; Aydin, Atilla; Wongseekaew, Kanitsorn; Maneelok, Wichanee

    2016-09-01

    The fractures in the porcelanites from the Monterey Formation in California USA and the Sap Bon Formation in Central Thailand were documented for a comparative study of their modes, distribution, and their relationship to other structures such as folds and bedding planes. Both formations consist in thinly bedded stiff units that are prone to folding, flexural slip, and cross-bedding brittle fracturing under compression. There are two assemblages in the porcelanites. The first assemblage includes commonly vertical high-angle opening mode fractures, left-lateral strike-slip faults, normal faults, and thrust faults. The second one is sub-horizontal fractures which are associated with folds, bedding slip, and thrusts faults in both Monterey and Sap Bon formations. The structural architectures of these rocks and the associated groups of structures are remarkably similar in terms of both opening and shearing modes and their relationships with the bedding due to their depositional architecture and the compressional tectonic regimes, in spite of the fact that the two locations are more than ten thousand kilometers apart and have very different ages of deformation.

  10. Hydrogeological characterization of Gold Valley: an investigation of precipitation recharge in an intermountain basin in the Death Valley region, California, USA

    NASA Astrophysics Data System (ADS)

    Abdulaziz, Abdulaziz M.; Hurtado, José M.; Faid, Abdalla

    2012-06-01

    Gold Valley is typical of intermountain basins in Death Valley National Park (DVNP), California (USA). Using water-balance calculations, a GIS-based analytical model has been developed to estimate precipitational infiltration rates from catchment-scale topographic data (elevation and slope). The calculations indicate that groundwater recharge mainly takes place at high elevations (>1,100 m) during winter (average 1.78 mm/yr). A resistivity survey suggests that groundwater accumulates in upstream compartmentalized reservoirs and that the groundwater flows through basin fill and fractured bedrock. This explains the relationship between the upstream precipitational infiltration in Gold Valley and the downstream spring flow in Willow Creek. To verify the ability of local recharge to support high-flux springs in DVNP, a GIS-based model was also applied to the Furnace Creek catchment. The results produced insufficient total volume of precipitational infiltration to support flow from the main high-flux springs in DVNP under current climatic conditions. This study introduces a GIS-based infiltration model that can be integrated into the Death Valley regional groundwater flow model to estimate precipitational infiltration recharge. In addition, the GIS-based model can efficiently estimate local precipitational infiltration in similar intermountain basins in arid regions provided that the validity of the model is verified.

  11. High Abundances of Potentially Active Ammonia-Oxidizing Bacteria and Archaea in Oligotrophic, High-Altitude Lakes of the Sierra Nevada, California, USA

    PubMed Central

    Hayden, Curtis J.; Beman, J. Michael

    2014-01-01

    Nitrification plays a central role in the nitrogen cycle by determining the oxidation state of nitrogen and its subsequent bioavailability and cycling. However, relatively little is known about the underlying ecology of the microbial communities that carry out nitrification in freshwater ecosystems—and particularly within high-altitude oligotrophic lakes, where nitrogen is frequently a limiting nutrient. We quantified ammonia-oxidizing archaea (AOA) and bacteria (AOB) in 9 high-altitude lakes (2289–3160 m) in the Sierra Nevada, California, USA, in relation to spatial and biogeochemical data. Based on their ammonia monooxygenase (amoA) genes, AOB and AOA were frequently detected. AOB were present in 88% of samples and were more abundant than AOA in all samples. Both groups showed >100 fold variation in abundance between different lakes, and were also variable through time within individual lakes. Nutrient concentrations (ammonium, nitrite, nitrate, and phosphate) were generally low but also varied across and within lakes, suggestive of active internal nutrient cycling; AOB abundance was significantly correlated with phosphate (r2 = 0.32, p<0.1), whereas AOA abundance was inversely correlated with lake elevation (r2 = 0.43, p<0.05). We also measured low rates of ammonia oxidation—indicating that AOB, AOA, or both, may be biogeochemically active in these oligotrophic ecosystems. Our data indicate that dynamic populations of AOB and AOA are found in oligotrophic, high-altitude, freshwater lakes. PMID:25402442

  12. Relations of hydrogeologic factors, groundwater reduction-oxidation conditions, and temporal and spatial distributions of nitrate, Central-Eastside San Joaquin Valley, California, USA

    USGS Publications Warehouse

    Landon, Matthew K.; Green, Christopher T.; Belitz, Kenneth; Singleton, Michael J.; Esser, Bradley K.

    2011-01-01

    In a 2,700-km2 area in the eastern San Joaquin Valley, California (USA), data from multiple sources were used to determine interrelations among hydrogeologic factors, reduction-oxidation (redox) conditions, and temporal and spatial distributions of nitrate (NO3), a widely detected groundwater contaminant. Groundwater is predominantly modern, or mixtures of modern water, with detectable NO3 and oxic redox conditions, but some zones have anoxic or mixed redox conditions. Anoxic conditions were associated with long residence times that occurred near the valley trough and in areas of historical groundwater discharge with shallow depth to water. Anoxic conditions also were associated with interactions of shallow, modern groundwater with soils. NO3 concentrations were significantly lower in anoxic than oxic or mixed redox groundwater, primarily because residence times of anoxic waters exceed the duration of increased pumping and fertilizer use associated with modern agriculture. Effects of redox reactions on NO3 concentrations were relatively minor. Dissolved N2 gas data indicated that denitrification has eliminated >5 mg/L NO3–N in about 10% of 39 wells. Increasing NO3 concentrations over time were slightly less prevalent in anoxic than oxic or mixed redox groundwater. Spatial and temporal trends of NO3 are primarily controlled by water and NO3 fluxes of modern land use.

  13. Relations of hydrogeologic factors, groundwater reduction-oxidation conditions, and temporal and spatial distributions of nitrate, Central-Eastside San Joaquin Valley, California, USA

    NASA Astrophysics Data System (ADS)

    Landon, Matthew K.; Green, Christopher T.; Belitz, Kenneth; Singleton, Michael J.; Esser, Bradley K.

    2011-09-01

    In a 2,700-km2 area in the eastern San Joaquin Valley, California (USA), data from multiple sources were used to determine interrelations among hydrogeologic factors, reduction-oxidation (redox) conditions, and temporal and spatial distributions of nitrate (NO3), a widely detected groundwater contaminant. Groundwater is predominantly modern, or mixtures of modern water, with detectable NO3 and oxic redox conditions, but some zones have anoxic or mixed redox conditions. Anoxic conditions were associated with long residence times that occurred near the valley trough and in areas of historical groundwater discharge with shallow depth to water. Anoxic conditions also were associated with interactions of shallow, modern groundwater with soils. NO3 concentrations were significantly lower in anoxic than oxic or mixed redox groundwater, primarily because residence times of anoxic waters exceed the duration of increased pumping and fertilizer use associated with modern agriculture. Effects of redox reactions on NO3 concentrations were relatively minor. Dissolved N2 gas data indicated that denitrification has eliminated >5 mg/L NO3-N in about 10% of 39 wells. Increasing NO3 concentrations over time were slightly less prevalent in anoxic than oxic or mixed redox groundwater. Spatial and temporal trends of NO3 are primarily controlled by water and NO3 fluxes of modern land use.

  14. Chemical evolution of shallow playa groundwater in response to post-pluvial isostatic rebound, Honey Lake Basin, California-Nevada, USA

    NASA Astrophysics Data System (ADS)

    Mayo, Alan L.; Henderson, Rachel M.; Tingey, David; Webber, William

    2010-05-01

    The 1,750-km2 endorheic Honey Lake basin (California-Nevada, USA) was part of the 22,000-km2 Pleistocene Lake Lahontan pluvial lake system which existed between 5,000 and 40,000 years BP. The basin consists of two subbasins separated by a low elevation divide. Groundwater in the western subbasin has a maximum total dissolved solids (TDS) content of only ˜1,300 mg/L; however eastern subbasin groundwater has a maximum TDS of ˜46,000 mg/L. This TDS distribution is unexpected because 94% of surface water TDS loading is to the western subbasin. In situ reactions and upwelling thermal groundwater contributing to groundwater chemistry were modeled using NETPATH. The TDS difference between the subbasins is attributed to post-Lake Lahontan isostatic rebound about 13,000 years ago. Prior to rebound the subbasins did not exist and the low point of the basin was in the eastern area where hydraulic isolation from the larger Lake Lahontan and frequent desiccation of the basin surface water resulted in evaporite mineral deposition in accumulating sediments. After rebound, the terminal sink for most surface water shifted to the western subbasin. Although most closed basins have not been impacted by isostatic rebound, results of this investigation demonstrate how tectonic evolution can impact the distribution of soluble minerals accumulating in shallow basins.

  15. Evaluation of a floating fish guidance structure at a hydrodynamically complex river junction in the Sacramento–San Joaquin River Delta, California, USA

    USGS Publications Warehouse

    Romine, Jason G.; Perry, Russell W.; Pope, Adam C.; Stumpner, Paul; Liedtke, Theresa L.; Kumagai, Kevin K; Reeves, Ryan L

    2016-01-01

    Survival of out-migrating juvenile Chinook salmon (Oncorhynchus tshawytscha) in the Sacramento–San Joaquin River delta, California, USA, varies by migration route. Survival of salmonids that enter the interior and southern Delta can be as low as half that of salmonids that remain in the main-stem Sacramento River. Reducing entrainment into the higher-mortality routes, such as Georgiana Slough, should increase overall survival. In spring 2014, a floating fish-guidance structure (FFGS) designed to reduce entrainment into Georgiana Slough was deployed just upstream of the Georgiana Slough divergence. We used acoustic telemetry to evaluate the effect of the FFGS on Chinook entrainment to Georgiana Slough. At intermediate discharge (200–400 m3 s–1), entrainment into Georgiana Slough was five percentage points lower when the FFGS was in the on state (19.1% on; 23.9% off). At higher discharge (>400 m3 s–1), entrainment was higher when the FFGS was in the on state (19.3% on; 9.7% off), and at lower discharge (0–200 m3 s–1) entrainment was lower when the FFGS was in the on state (43.7% on; 47.3% off). We found that discharge, cross-stream fish position, time of day, and proportion of flow remaining in the Sacramento River contributed to the probability of being entrained to Georgiana Slough.

  16. Correlation between response of human cell line and distribution of sediment polycyclic aromatic hydrocarbons and polychlorinated biphenyls on Palos Verdes Shelf, California, USA

    SciTech Connect

    Anderson, J.W.; Zeng, E.Y.; Jones, J.M.

    1999-07-01

    Sections of a sediment core collected from Station 7C near the County Sanitation Districts of Los Angeles County, California, USA, outfall were analyzed for total organic carbon (TOC), polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs). In addition, the biological responses to extracts from the same samples were determined using the P450 reporter gene system (RGS) assay. The profiles of TOC, PAHs, and PCBs were consistent in illustrating the predischarge baseline and the effects of improving wastewater treatment. Induction of the CYP1A1 gene using P450 RGS was correlated with total PAHs and better correlated with the B[a]P toxic equivalency quotients calculated using toxic equivalency factors (TEFs) derived from P450 RGS analyses of individual high molecular weight PAHs. Results from short (6 h) and long (16 h) exposures using the RGS assay suggested that a portion of the induction was from the slower acting chlorinated hydrocarbons (coplanar PCBs, dioxins, furans, etc.). Coplanar PCBs in the amounts of 0.9 to 3.1 {micro}g/g were found in three core sections analyzed; hence the induction of RGS was likely produced by both PAHs and coplanar PCBs. Since dioxins and furans were not analyzed, their contributions to the RGS responses are unknown. The RGS assay may be used to screen samples for potential toxicological importance before conducting costly chemical analyses.

  17. Annual Quality Assurance Conference Abstracts by Barbara Marshik

    EPA Pesticide Factsheets

    25th Annual Quality Assurance Conference. Abstracts: Material and Process Conditions for Successful Use of Extractive Sampling Techniques and Certification Methods Errors in the Analysis of NMHC and VOCs in CNG-Based Engine Emissions by Barbara Marshik

  18. Santa Barbara Cluster Comparison Test with DISPH

    NASA Astrophysics Data System (ADS)

    Saitoh, Takayuki R.; Makino, Junichiro

    2016-06-01

    The Santa Barbara cluster comparison project revealed that there is a systematic difference between entropy profiles of clusters of galaxies obtained by Eulerian mesh and Lagrangian smoothed particle hydrodynamics (SPH) codes: mesh codes gave a core with a constant entropy, whereas SPH codes did not. One possible reason for this difference is that mesh codes are not Galilean invariant. Another possible reason is the problem of the SPH method, which might give too much “protection” to cold clumps because of the unphysical surface tension induced at contact discontinuities. In this paper, we apply the density-independent formulation of SPH (DISPH), which can handle contact discontinuities accurately, to simulations of a cluster of galaxies and compare the results with those with the standard SPH. We obtained the entropy core when we adopt DISPH. The size of the core is, however, significantly smaller than those obtained with mesh simulations and is comparable to those obtained with quasi-Lagrangian schemes such as “moving mesh” and “mesh free” schemes. We conclude that both the standard SPH without artificial conductivity and Eulerian mesh codes have serious problems even with such an idealized simulation, while DISPH, SPH with artificial conductivity, and quasi-Lagrangian schemes have sufficient capability to deal with it.

  19. Isotope geochemistry of mercury in source rocks, mineral deposits and spring deposits of the California Coast Ranges, USA

    USGS Publications Warehouse

    Smith, C.N.; Kesler, S.E.; Blum, J.D.; Rytuba, J.J.

    2008-01-01

    We present here the first study of the isotopic composition of mercury in rocks, ore deposits, and active spring deposits from the California Coast Ranges, a part of Earth's crust with unusually extensive evidence of mercury mobility and enrichment. The Franciscan Complex and Great Valley Sequence, which form the bedrock in the California Coast Ranges, are intruded and overlain by Tertiary volcanic rocks including the Clear Lake Volcanic Sequence. These rocks contain two types of mercury deposits, hot-spring deposits that form at shallow depths (< 300??m) and silica-carbonate deposits that extend to depths of 1000??m. Active springs and geothermal areas continue to precipitate Hg and Au and are modern analogues to the fossil hydrothermal systems preserved in the ore deposits. The Franciscan Complex and Great Valley Sequence contain clastic sedimentary rocks with higher concentrations of mercury than volcanic rocks of the Clear Lake Volcanic Field. Mean mercury isotopic compositions (??202Hg) for all three rock units are similar, although the range of values in Franciscan Complex rocks is greater than in either Great Valley or Clear Lake rocks. Hot spring and silica-carbonate mercury deposits have similar average mercury isotopic compositions that are indistinguishable from averages for the three rock units, although ??202Hg values for the mercury deposits have a greater variance than the country rocks. Precipitates from spring and geothermal waters in the area have similarly large variance and a mean ??202Hg value that is significantly lower than the ore deposits and rocks. These observations indicate that there is little or no isotopic fractionation (< ?? 0.5???) during release of mercury from its source rocks into hydrothermal solutions. Isotopic fractionation does appear to take place during transport and concentration of mercury in deposits, however, especially in their uppermost parts. Boiling of hydrothermal fluids, separation of a mercury-bearing CO2 vapor

  20. Impact of seasonality and anthropogenic impoundments on dissolved organic matter dynamics in the Klamath River (Oregon/California, USA)

    NASA Astrophysics Data System (ADS)

    Oliver, Allison A.; Spencer, Robert G. M.; Deas, Michael L.; Dahlgren, Randy A.

    2016-07-01

    Rivers play a major role in the transport and processing of dissolved organic matter (DOM). Disturbances that impact DOM dynamics, such as river impoundments and flow regulation, have consequences for biogeochemical cycling and aquatic ecosystems. In this study we examined how river impoundments and hydrologic regulation impact DOM quantity and quality by tracking spatial and seasonal patterns of DOM in a large, regulated river (Klamath River, USA). Dissolved organic carbon (DOC) concentrations decreased downstream and longitudinal patterns in DOC load varied by season. Export of DOM (as DOC) was largely driven by river flow, while DOM composition was strongly influenced by impoundments. Seasonal algal blooms in upstream lentic reaches provided a steady source of algal DOM that was processed in downstream reaches. DOM at upstream sites had an average spectral slope ratio (SR) > 1, indicating algal-derived material, but decreased downstream to an average SR < 1, more indicative of terrestrial-derived material. The increasingly terrestrial nature of DOM exported from reservoirs likely reflects degraded algal material that becomes increasingly more recalcitrant with distance from upstream source and additional processing. As a result, DOM delivered to free-flowing river reaches below impoundments was less variable in composition. Downstream of impoundments, tributary influences resulted in increasing contributions of terrestrial DOM from the surrounding watershed. Removal of the four lower dams on the Klamath River is scheduled to proceed in the next decade. These results suggest that management should consider the role of impoundments on altering DOM dynamics, particularly in the context of dam removal.

  1. Peat Formation Processes Through the Millennia in Tidal Marshes of the Sacramento-San Joaquin Delta, California, USA

    USGS Publications Warehouse

    Drexler, J.Z.

    2011-01-01

    The purpose of this study was to determine peat formation processes throughout the millennia in four tidal marshes in the Sacramento-San Joaquin Delta. Peat cores collected at each site were analyzed for bulk density, loss on ignition, and percent organic carbon. Core data and spline fit age-depth models were used to estimate inorganic sedimentation, organic accumulation, and carbon sequestration rates in the marshes. Bulk density and percent organic matter content of peat fluctuated through time at all sites, suggesting that peat formation processes are dynamic and responsive to watershed conditions. The balance between inorganic sedimentation and organic accumulation at the sites also varied through time, indicating that marshes may rely more strongly on either inorganic or organic matter for peat formation at particular times in their existence. Mean carbon sequestration rates found in this study (0. 38-0. 79 Mg C ha-1 year-1) were similar to other long-term estimates for temperate peatlands. ?? 2011 Coastal and Estuarine Research Federation (outside the USA).

  2. Differential tolerance of native and nonnative fish exposed to ultraviolet radiation and fluoranthene in Lake Tahoe (California/Nevada), USA.

    PubMed

    Gevertz, Amanda K; Tucker, Andrew J; Bowling, Anna M; Williamson, Craig E; Oris, James T

    2012-05-01

    Within Lake Tahoe (CA/NV), USA, multiple environmental stressors are present that can affect both native and nonnative fish species. Stressors include natural ultraviolet radiation (UVR) and polycyclic aromatic hydrocarbons (PAHs). Many PAHs, such as fluoranthene (FLU) are phototoxic to aquatic organisms in the presence of UVR. Decreasing levels of UVR due to eutrophication and increasing levels of PAHs due to recreational activities may combine to affect the relative ability of native versus nonnative fish species to survive in the lake. The objective of the present study was to examine the differential effects of exposure to different levels of UVR and phototoxic FLU in native and nonnative fish species. Responses to these changes in the native Lahontan redside minnow (Richardsonius egregius) and the nonnative warm-water bluegill sunfish (Lepomis macrochirus) were compared during toxicity tests, which were conducted in controlled outdoor exposures. Physiological defenses were also investigated in an attempt to elucidate ways each species may tolerate UVR and UVR + FLU exposures. It was determined that the native redside minnow is more tolerant to UVR and UVR + FLU exposure when compared to the nonnative bluegill. In addition, a natural UVR coping mechanism, increased pigmentation, is exhibited to a greater extent in the native redside. The present study will help determine the potential for a future successful invasion of the bluegill and similar species in Lake Tahoe and other oligotrophic, montane lakes that are susceptible to habitat alteration, nutrient inputs, and recreational activity.

  3. Regional variations in water quality and relationships to soil and bedrock weathering in the southern Sacramento Valley, California, USA

    USGS Publications Warehouse

    Wanty, R.B.; Goldhaber, M.B.; Morrison, J.M.; Lee, L.

    2009-01-01

    Regional patterns in ground- and surface-water chemistry of the southern Sacramento Valley in California were evaluated using publicly available geochemical data from the US Geological Survey's National Water Information System (NWIS). Within the boundaries of the study area, more than 2300 ground-water analyses and more than 20,000 surface-water analyses were available. Ground-waters from the west side of the Sacramento Valley contain greater concentrations of Na, Ca, Mg, B, Cl and SO4, while the east-side ground-waters contain greater concentrations of silica and K. These differences result from variations in surface-water chemistry as well as from chemical reactions between water and aquifer materials. Sediments that fill the Sacramento Valley were derived from highlands to the west (the Coast Ranges) and east (the Sierra Nevada Mountains), the former having an oceanic provenance and the latter continental. These geologic differences are at least in part responsible for the observed patterns in ground-water chemistry. Thermal springs that are common along the west side of the Sacramento Valley appear to have an effect on surface-water chemistry, which in turn may affect the ground-water chemistry.

  4. Weathering and transport of chromium and nickel from serpentinite in the Coast Range ophiolite to the Sacramento Valley, California, USA

    USGS Publications Warehouse

    Morrison, Jean M.; Goldhaber, Martin B.; Mills, Christopher T.; Breit, George N.; Hooper, Robert L.; Holloway, JoAnn M.; Diehl, Sharon F.; Ranville, James F.

    2015-01-01

    A soil geochemical study in northern California was done to investigate the role that weathering and transport play in the regional distribution and mobility of geogenic Cr and Ni, which are both potentially toxic and carcinogenic. These elements are enriched in ultramafic rocks (primarily serpentinite) and the soils derived from them (1700–10,000 mg Cr per kg soil and 1300–3900 mg Ni per kg soil) in the Coast Range ophiolite. Chromium and Ni have been transported eastward from the Coast Range into the western Sacramento Valley and as a result, valley soil is enriched in Cr (80–1420 mg kg−1) and Ni (65–224 mg kg−1) compared to median values of U.S. soils of 50 and 15 mg kg−1, respectively. Nickel in ultramafic source rocks and soils is present in serpentine minerals (lizardite, antigorite, and chrysotile) and is more easily weathered compared to Cr, which primarily resides in highly refractory chromite ([Mg,Fe2+][Cr3+,Al,Fe3+]2O4). Although the majority of Cr and Ni in soils are in refractory chromite and serpentine minerals, the etching and dissolution of these minerals, presence of Cr- and Ni-enriched clay minerals and development of nanocrystalline Fe (hydr)oxides is evidence that a significant fractions of these elements have been transferred to potentially more labile phases.

  5. Can private land conservation reduce wildfire risk to homes? A case study in San Diego County, California, USA

    USGS Publications Warehouse

    Butsic, Van; Syphard, Alexandra D.; Keeley, Jon E.; Bar-Massada, Avi

    2017-01-01

    The purchase of private land for conservation purposes is a common way to prevent the exploitation of sensitive ecological areas. However, private land conservation can also provide other benefits, one of these being natural hazard reduction. Here, we investigated the impacts of private land conservation on fire risk to homes in San Diego County, California. We coupled an econometric land use change model with a model that estimates the probability of house loss due to fire in order to compare fire risk at the county and municipality scale under alternative private land purchasing schemes and over a 20 year time horizon. We found that conservation purchases could reduce fire risk on this landscape, and the amount of risk reduction was related to the targeting approach used to choose which parcels were conserved. Conservation land purchases that targeted parcels designated as high fire hazard resulted in lower fire risk to homes than purchases that targeted low costs or high likelihood to subdivide. This result was driven by (1) preventing home placement in fire prone areas and (2) taking land off the market, and hence increasing development densities in other areas. These results raise the possibility that resource conservation and fire hazard reduction may benefit from combining efforts. With adequate planning, future conservation purchases could have synergistic effects beyond just protecting ecologically sensitive areas.

  6. Mineralogy, textures, and relative age relationships of massive sulfide ore in the West Shasta district, California ( USA).

    USGS Publications Warehouse

    Howe, S.S.

    1985-01-01

    The Devonian massive sulfide orebodies of the West Shasta district in N California are composed primarily of pyrite, with lesser amounts of other sulfide and gangue minerals. Examination of polished thin sections of more than 100 samples from the Mammoth, Shasta King, Early Bird, Balaklala, Keystone, and Iron Mountain mines suggests that mineralization may be divided into 6 paragenetic stages, the last 5 each separated by an episode of deformation: 1) precipitation of fine-grained, locally colloform and framboidal pyrite and sphalerite; 2) deposition of fine-grained arsenopyrite and coarse-grained pyrite; 3) penetration and local replacement of sulfide minerals of stages 1 and 2 along growth zones and fractures by chalcopyrite, sphalerite, galena, tennantite, pyrrhotite, bornite, and idaite; 4) recrystallization and remobilization of existing minerals; 5) deposition of quartz, white mica, chlorite, and calcite; and 6) formation of bornite, digenite, chalcocite, and covellite during supergene enrichment of several orebodies at the Iron Mountain mine. Mineralogic and textural evidence do not support a second major episode of massive sulfide mineralization during the Permian. -from Author

  7. Novel poxvirus infection in northern and southern sea otters (Enhydra lutris kenyoni and Enhydra lutris neiris), Alaska and California, USA.

    PubMed

    Tuomi, Pamela A; Murray, Michael J; Garner, Michael M; Goertz, Caroline E C; Nordhausen, Robert W; Burek-Huntington, Kathleen A; Getzy, David M; Nielsen, Ole; Archer, Linda L; Maness, Heather T D; Wellehan, James F X; Waltzek, Thomas B

    2014-07-01

    Small superficially ulcerated skin lesions were observed between October 2009 and September 2011 during captive care of two orphaned sea otter pups: one northern (Enhydra lutris kenyoni) in Alaska and one southern (Enhydra lutris nereis) in California. Inclusions consistent with poxviral infection were diagnosed by histopathology in both cases. Virions consistent with poxvirus virions were seen on electron microscopy in the northern sea otter, and the virus was successfully propagated in cell culture. DNA extraction, pan-chordopoxviral PCR amplification, and sequencing of the DNA-dependent DNA polymerase gene revealed that both cases were caused by a novel AT-rich poxvirus. Bayesian and maximum likelihood phylogenetic analyses found that the virus is divergent from other known poxviruses at a level consistent with a novel genus. These cases were self-limiting and did not appear to be associated with systemic illness. To our knowledge, this is the first report of a poxvirus in a mustelid species. The source of this virus, mode of transmission, zoonotic potential, and biological significance are undetermined.

  8. Pathogen infection and exposure, and ectoparasites of the federally endangered Amargosa vole (Microtus californicus scirpensis), California, USA.

    PubMed

    Ott-Conn, Caitlin N; Clifford, Deana; Branston, Tammy; Klinger, Robert; Foley, Janet

    2014-10-01

    Abstract We surveyed pathogens and ectoparasites among federally endangered Amargosa voles (Microtus californicus scirpensis) and sympatric rodents in Tecopa Hot Springs, Inyo County, California, December 2011-November 2012. We aimed to assess disease and detect possible spillover from or connectivity with other hosts within and outside the Amargosa ecosystem. We assessed 71 individual voles and 38 individual sympatric rodents for current infection with seven vector-borne zoonotic pathogens and past exposure to five pathogens. Thirteen percent of Amargosa voles were PCR positive for Toxoplasma gondii, a zoonotic protozoan that may alter host behavior or cause mortality. Additionally, we found antibodies against Borrelia burgdorferi sensu lato (SL) spp. in 21% of voles, against Anaplasma phagocytophilum in 2.6%, Rickettsia spp. in 13%, relapsing fever Borrelia (3.9%), and T. gondii (7.9%). Sympatric rodents also had active infections with Borrelia SL spp. (15%). Of the ectoparasites collected, the tick Ixodes minor is of particular interest because the study area is well outside of the species' reported range and because I. minor ticks infest migratory birds as well as rodents, showing a potential mechanism for pathogens to be imported from outside the Amargosa ecosystem.

  9. The legacy of wetland drainage on the remaining peat in the Sacramento San Joaquin Delta, California, USA

    USGS Publications Warehouse

    Drexler, J.Z.; De Fontaine, C. S.; Deverel, S.J.

    2009-01-01

    Throughout the world, many extensive wetlands, such as the Sacramento-San Joaquin Delta of California (hereafter, the Delta), have been drained for agriculture, resulting in land-surface subsidence of peat soils. The purpose of this project was to study the in situ effects of wetland drainage on the remaining peat in the Delta. Peat cores were retrieved from four drained, farmed islands and four relatively undisturbed, marsh islands. Core samples were analyzed for bulk density and percent organic carbon. Macrofossils in the peat were dated using radiocarbon age determination. The peat from the farmed islands is highly distinct from marsh island peat. Bulk density of peat from the farmed islands is generally greater than that of the marsh islands at a given organic carbon content. On the farmed islands, increased bulk density, which is an indication of compaction, decreases with depth within the unoxidized peat zone, whereas, on the marsh islands, bulk density is generally constant with depth except near the surface. Approximately 5580 of the original peat layer on the farmed islands has been lost due to land-surface subsidence. For the center regions of the farmed islands, this translates into an estimated loss of between 29005700 metric tons of organic carbon/hectare. Most of the intact peat just below the currently farmed soil layer is over 4000 years old. Peat loss will continue as long as the artificial water table on the farmed islands is held below the land surface. ?? 2009 The Society of Wetland Scientists.

  10. The legacy of wetland drainage on the remaining peat in the Sacramento-San Joaquin Delta, California, USA

    USGS Publications Warehouse

    Drexler, Judith Z.; Christian S. de Fontaine,; Steven J. Deverel,

    2009-01-01

    Throughout the world, many extensive wetlands, such as the Sacramento-San Joaquin Delta of California (hereafter, the Delta), have been drained for agriculture, resulting in land-surface subsidence of peat soils. The purpose of this project was to study the in situ effects of wetland drainage on the remaining peat in the Delta. Peat cores were retrieved from four drained, farmed islands and four relatively undisturbed, marsh islands. Core samples were analyzed for bulk density and percent organic carbon. Macrofossils in the peat were dated using radiocarbon age determination. The peat from the farmed islands is highly distinct from marsh island peat. Bulk density of peat from the farmed islands is generally greater than that of the marsh islands at a given organic carbon content. On the farmed islands, increased bulk density, which is an indication of compaction, decreases with depth within the unoxidized peat zone, whereas, on the marsh islands, bulk density is generally constant with depth except near the surface. Approximately 55–80% of the original peat layer on the farmed islands has been lost due to landsurface subsidence. For the center regions of the farmed islands, this translates into an estimated loss of between 2900-5700 metric tons of organic carbon/hectare. Most of the intact peat just below the currently farmed soil layer is over 4000 years old. Peat loss will continue as long as the artificial water table on the farmed islands is held below the land surface.

  11. Kinematic significance of L tectonites in the footwall of a major terrane-bounding thrust fault, Klamath Mountains, California, USA

    NASA Astrophysics Data System (ADS)

    Sullivan, W. A.

    2009-11-01

    Detailed geologic mapping, cross-section reconstructions, strain analyses, and kinematic analyses, enable the reconstruction of a ˜one-kilometer-wide domain of L tectonites in the east-west-striking, subhorizontal to gently south-dipping Pigeon Point high-strain zone (PPHSZ) associated with a major thrust fault separating oceanic- and arc-affinity terranes in the Klamath Mountains, California. L tectonites are associated with: (1) a convex-upward warp of the upper high-strain-zone boundary, (2) a transition from mafic metavolcaniclastic rocks to micaceous quartzites, (3) folds subparallel with mineral lineations, (4) emplacement of synkinematic ultramafic/mafic intrusive bodies, and (5) a local temperature increase from greenschist- to amphibolite-facies conditions. Pure-shear-dominated deformation accommodated zone-normal shortening and transport-parallel elongation coupled with subordinate top-to-the-west-directed, thrust-style simple shear. L tectonite formation was controlled by the shape of the high-strain-zone boundary driving lateral flow into the apex of the lens-shaped zone in response to a favorable kinematic geometry and bulk strain in the constrictional field. Localized magmatic heating best explains the shape of the high-strain-zone boundary, but L tectonites are not partitioned into a single rheological domain. During terrane amalgamation strain-path partitioning occurred with localized top-to-the-west-directed simple shear partitioned into a structurally overlying thrust zone and pure-shear-dominated subvertical shortening and transport-parallel elongation partitioned into the PPHSZ.

  12. Can We Mitigate Climate Extremes using Managed Aquifer Recharge: Case Studies California Central Valley and South-Central Arizona, USA

    NASA Astrophysics Data System (ADS)

    Scanlon, B. R.; Reedy, R. C.; Faunt, C. C.; Pool, D. R.; Uhlman, K.

    2015-12-01

    Frequent long-term droughts interspersed with intense floods in the southwestern U.S. underscore the need to store more water to manage these climate extremes. Here we show how managed aquifer recharge can enhance drought resilience in the southwestern U.S. with ~ 70% of California under extreme drought and 75% of Arizona under moderate drought. Data on water sources, transportation, and users were compiled for managed aquifer recharge systems in the Central Valley and south-central Arizona. Groundwater depletion of 115 to 145 km3 in the 1900s created large subsurface reservoirs in thick alluvial basins in these regions. Large canals and aqueducts up to several 100 km long allow water to be imported from reservoirs, mostly in more humid regions. Imported water is either used instead of groundwater or is applied in surface spreading basins primarily during wet periods (≤1.3 km3/yr Central Valley, ≤0.7 km3/yr Arizona) and is extracted during droughts. The dominant water users include irrigators and municipalities both within and outside the managed aquifer recharge systems. Groundwater modeling indicates that recharge basins significantly increase groundwater storage in the Central Valley. Managed aquifer recharge systems significantly enhance drought resilience and increase sustainability of water resources in semiarid regions, complementing surface water reservoirs and conjunctive surface water/groundwater use by providing longer term storage.

  13. Controls on mineralisation in the Sierra Foothills gold province, central California, USA: A GIS-based reconnaissance prospectivity analysis

    USGS Publications Warehouse

    Bierlein, F.P.; Northover, H.J.; Groves, D.I.; Goldfarb, R.J.; Marsh, E.E.

    2008-01-01

    The assessment of spatial relationships between the location, abundance and size of orogenic-gold deposits in the highly endowed Sierra Foothills gold province in California, via the combination of field studies and a GIS-based analysis, illustrates the power of such an approach to the characterisation of important parameters of mineral systems, and the prediction of districts likely to host economic mineralisation. Regional- to deposit-scale reconnaissance mapping suggests that deposition of gold-bearing quartz veins occurred in second- and third-order, east-over-west thrusts during regional east - west compression and right-lateral transpression. At the district-scale, significant zones of mineralisation correspond with such transpressional reactivation zones and dilational jogs that developed during the Late Jurassic - Early Cretaceous along the misaligned segments of first-order faults throughout the Sierra Nevada Foothills Metamorphic Belt. Field-based observations and interpretation of GIS data (including solid geology, structural elements, deposit locations, magnetics, gravity) also highlight the importance of structural permeability contrasts, rheological gradients, and variations in fault orientation for localising mineralisation. Although this approach confirms empirical findings and produces promising results at the province scale, enhanced geological, structural, geophysical and geochronological data density is required to generate regionally consistent, high-quality input layers that improve predictive targeting at the goldfield to deposit-scale.

  14. Geochemical evidence for Se mobilization by the weathering of pyritic shale, San Joaquin Valley, California, U.S.A.

    USGS Publications Warehouse

    Presser, T.S.; Swain, W.C.

    1990-01-01

    Acidic (pH 4) seeps issue from the weathered Upper Cretaceous-Paleocene marine sedimentary shales of the Moreno Formation in the semi-arid Coast Ranges of California. The chemistry of the acidic solutions is believed to be evidence of current reactions ultimately yielding hydrous sodium and magnesium sulfate salts, e.g. mirabilite and bloedite, from the oxidation of primary pyrite. The selenate form of Se is concentrated in these soluble salts, which act as temporary geological sinks. Theoretically, the open lattice structures of these hydrous minerals could incorporate the selenate (SeO4-2) anion in the sulfate (SO4-2) space. When coupled with a semi-arid to arid climate, fractional crystallization and evaporative concentration can occur creating a sodium-sulfate fluid that exceeds the U.S. Environmental Protection Agency limit of 1000 ??g l-1 for a toxic Se waste. The oxidative alkaline conditions necessary to ensure the concentration of soluble selenate are provided in the accompanying marine sandstones of the Panoche and Lodo Formations and the eugeosynclinal Franciscan assemblage. Runoff and extensive mass wasting in the area reflect these processes and provide the mechanisms which transport Se to the farmlands of the west-central San Joaquin Valley. Subsurface drainage from these soils consequently transports Se to refuge areas in amounts elevated to cause a threat to wildlife. ?? 1990.

  15. Reactive iron and manganese distributions in seabed sediments near small mountainous rivers off Oregon and California (USA)

    NASA Astrophysics Data System (ADS)

    Roy, Moutusi; McManus, James; Goñi, Miguel A.; Chase, Zanna; Borgeld, Jeffry C.; Wheatcroft, Robert A.; Muratli, Jesse M.; Megowan, Meghan R.; Mix, Alan

    2013-02-01

    We examined the spatial distribution of sedimentary reactive iron (FeR) and manganese (MnR) along the continental shelf near the mouth of the Umpqua River, Oregon (USA). A well-defined muddy (silt+clay) depocenter of fluvial origin characterizes this part of the Oregon margin. Reactive Fe and Mn contents are elevated within the silt-rich landward edge of the depocenter. Away from this depocenter, sediments are predominantly sandy both along the inner-shelf (<˜100 m depth) and mid-shelf (˜100-150 m depth) and have lower concentrations of reactive metals compared to the depocenter. Sediments are also muddy along the slope (>˜150 m depth) and have elevated FeR and MnR. Based on their correlation with sediment grain size, it appears that FeR and to a lesser extent MnR, are associated with mud size sediments. Reactive metal concentration is also positively correlated with organic carbon (OC) content, indicating a potentially common source. Seabed sediments from five other small, mountainous river systems (Klamath, Eel, Navarro, Russian, and Salinas) located south of Umpqua show the same general relationship between FeR and OC. Although both FeR and MnR exhibit similar relationships to grain size and OC, the relationships with MnR exhibit considerable scatter. Comparison of Umpqua River suspended sediment data with the seabed data suggests that MnR is more prone to loss from sediment particles during transit to the seabed as compared to FeR, and this difference explains why FeR maintains a reasonably tight relationship with organic carbon and particle size along the seafloor relative to MnR.

  16. Conceptualisations of masculinity and self-reported medication adherence among HIV-positive Latino men in Los Angeles, California, USA.

    PubMed

    Galvan, Frank H; Bogart, Laura M; Wagner, Glenn J; Klein, David J; Chen, Ying-Tung

    2014-06-01

    HIV-positive Latino men have been found to have poorer medication adherence compared to Whites. This study sought to identify how cultural conceptualisations of masculinity are associated with self-reported medication adherence among Latino men. A total of 208 HIV-positive men reported the number of doses of antiretroviral medication missed in the previous seven days (dichotomised at 100% adherence versus less). Conceptualisations of masculinity consisted of traditional machismo (e.g., power and aggressive attitudes, which are normally associated with negative stereotypes of machismo) and caballerismo (e.g., fairness, respect for elders and the importance of family). Multivariate logistic regression was used to identify factors associated with adherence. The mean adherence was 97% (SD = 6.5%; range = 57-100%). In all, 77% of the participants reported 100% adherence in the previous seven days. Caballerismo was associated with a greater likelihood (OR = 1.77; 95% CI: 1.08-2.92; p = 0.03) and machismo with a lower likelihood (OR = 0.60; 95% CI: 0.38-0.95; p = 0.03) of medication adherence. In addition, higher medication side-effects were found to be associated with a lower likelihood (OR = 0.59; 95% CI: 0.43-0.81; p = 0.001) of medication adherence. These findings reinforce the importance of identifying cultural factors that may affect medication adherence among HIV-positive Latino men resident in the USA.

  17. Impacts of Discharge Reductions on Physical and Thermal Habitat Characteristics in a Desert Spring, Death Valley National Park, California, USA

    NASA Astrophysics Data System (ADS)

    Morrison, R. R.; Stone, M. C.; Sada, D. W.

    2013-12-01

    Desert springs are biodiversity hotspots that are sensitive to anthropogenic activities. Despite their importance, the effects of human disturbance on desert springs are not well known, and scarce information exists describing the biotic or environmental effects of incrementally increasing disturbance. The objective of this research was to quantify the influence of incremental reductions in discharge on the physical and thermal characteristics of a desert springbrook. This objective was accomplished through a combination of field experiments at Travertine Spring in Death Valley National Park, USA, and hydraulic/temperature modeling in order to: (1) quantify changes in physical characteristics of the springbrook channel and aquatic environment; (2) investigate the effects of reduced spring discharge on seasonal spatial temperature patterns; (3) delineate tipping points that exhibit a non-linear response to decreased flow. The study results supported our predictions that decreased discharge would modify physical habitat characteristics of the springbrook, reduce aquatic habitat volume, increase variability in water temperatures along the springbrook, and reduce springbrook suitability for invertebrates that require stable environments. Field observations revealed a significant relationship between water depth and flow velocity with reduced spring discharge. The rate of change of mean water depths, velocities, and habitat volumes were greatest with only a 10% reduction in spring flow. In addition, a non-linear temperature response to flow reductions was present under all modeled conditions. Generally, water temperature gradients increased as flows were decreased, and the sensitivity of reduced discharge increased with distance from the spring source. The degree of sensitivity was a function of season, which reflects the influence of ambient air temperature and wind in the cooling of the springbrook. These results suggest that habitat for species using stable thermal

  18. Geomorphic controls on mercury accumulation in soils from a historically mined watershed, Central California Coast Range, USA

    USGS Publications Warehouse

    Holloway, J.M.; Goldhaber, M.B.; Morrison, J.M.

    2009-01-01

    Historic Hg mining in the Cache Creek watershed in the Central California Coast Range has contributed to the downstream transport of Hg to the San Francisco Bay-Delta. Different aspects of Hg mobilization in soils, including pedogenesis, fluvial redistribution of sediment, volatilization and eolian transport were considered. The greatest soil concentrations (>30 mg Hg kg-1) in Cache Creek are associated with mineralized serpentinite, the host rock for Hg deposits. Upland soils with non-mineralized serpentine and sedimentary parent material also had elevated concentrations (0.9-3.7 mg Hg kg-1) relative to the average concentration in the region and throughout the conterminous United States (0.06 mg kg-1). Erosion of soil and destabilized rock and mobilization of tailings and calcines into surrounding streams have contributed to Hg-rich alluvial soil forming in wetlands and floodplains. The concentration of Hg in floodplain sediment shows sediment dispersion from low-order catchments (5.6-9.6 mg Hg kg-1 in Sulphur Creek; 0.5-61 mg Hg kg-1 in Davis Creek) to Cache Creek (0.1-0.4 mg Hg kg-1). These sediments, deposited onto the floodplain during high-flow storm events, yield elevated Hg concentrations (0.2-55 mg Hg kg-1) in alluvial soils in upland watersheds. Alluvial soils within the Cache Creek watershed accumulate Hg from upstream mining areas, with concentrations between 0.06 and 0.22 mg Hg kg-1 measured in soils ~90 km downstream from Hg mining areas. Alluvial soils have accumulated Hg released through historic mining activities, remobilizing this Hg to streams as the soils erode.

  19. Contemporary Land Change Alters Fish Communities in a San Francisco Bay Watershed, California, U.S.A.

    PubMed Central

    Cervantes-Yoshida, Kristina; Leidy, Robert A.; Carlson, Stephanie M.

    2015-01-01

    Urbanization is one of the leading threats to freshwater biodiversity, and urban regions continue to expand globally. Here we examined the relationship between recent urbanization and shifts in stream fish communities. We sampled fishes at 32 sites in the Alameda Creek Watershed, near San Francisco, California, in 1993–1994 and again in 2009, and we quantified univariate and multivariate changes in fish communities between the sampling periods. Sampling sites were classified into those downstream of a rapidly urbanizing area (“urbanized sites”), and those found in less impacted areas (“low-impacted sites”). We calculated the change from non-urban to urban land cover between 1993 and 2009 at two scales for each site (the total watershed and a 3km buffer zone immediately upstream of each site). Neither the mean relative abundance of native fish nor nonnative species richness changed significantly between the survey periods. However, we observed significant changes in fish community composition (as measured by Bray-Curtis dissimilarity) and a decrease in native species richness between the sampling periods at urbanized sites, but not at low-impacted sites. Moreover, the relative abundance of one native cyprinid (Lavinia symmetricus) decreased at the urbanized sites but not at low-impacted sites. Increased urbanization was associated with changes in the fish community, and this relationship was strongest at the smaller (3km buffer) scale. Our results suggest that ongoing land change alters fish communities and that contemporary resurveys are an important tool for examining how freshwater taxa are responding to recent environmental change. PMID:26580560

  20. PEAT ACCRETION HISTORIES DURING THE PAST 6000 YEARS IN MARSHES OF THE SACRAMENTO - SAN JOAQUIN DELTA, CALIFORNIA, USA

    SciTech Connect

    Drexler, J Z; de Fontaine, C S; Brown, T A

    2009-07-20

    Peat cores were collected in 4 remnant marsh islands and 4 drained, farmed islands throughout the Sacramento - San Joaquin Delta of California in order to characterize the peat accretion history of this region. Radiocarbon age determination of marsh macrofossils at both marsh and farmed islands showed that marshes in the central and western Delta started forming between 6030 and 6790 cal yr BP. Age-depth models for three marshes were constructed using cubic smooth spline regression models. The resulting spline fit models were used to estimate peat accretion histories for the marshes. Estimated accretion rates range from 0.03 to 0.49 cm yr{sup -1} for the marsh sites. The highest accretion rates are at Browns Island, a marsh at the confluence of the Sacramento and San Joaquin rivers. Porosity was examined in the peat core from Franks Wetland, one of the remnant marsh sites. Porosity was greater than 90% and changed little with depth indicating that autocompaction was not an important process in the peat column. The mean contribution of organic matter to soil volume at the marsh sites ranges from 6.15 to 9.25% with little variability. In contrast, the mean contribution of inorganic matter to soil volume ranges from 1.40 to 8.45% with much greater variability, especially in sites situated in main channels. These results suggest that marshes in the Delta can be viewed as largely autochthonous vs. allochthonous in character. Autochthonous sites are largely removed from watershed processes, such as sediment deposition and scour, and are dominated by organic production. Allochthonous sites have greater fluctuations in accretion rates due to the variability of inorganic inputs from the watershed. A comparison of estimated vertical accretion rates with 20th century rates of global sea-level rise shows that currently marshes are maintaining their positions in the tidal frame, yet this offers little assurance of sustainability under scenarios of increased sea-level rise in

  1. Isotopic measurements of atmospheric methane in Los Angeles, California, USA: Influence of “fugitive” fossil fuel emissions

    NASA Astrophysics Data System (ADS)

    Townsend-Small, Amy; Tyler, Stanley C.; Pataki, Diane E.; Xu, Xiaomei; Christensen, Lance E.

    2012-04-01

    Recent studies have suggested that CH4 emissions in Los Angeles and other large cities may be underestimated. We utilized stable isotopes (13C and D) and radiocarbon (14C) to investigate sources of CH4 in Los Angeles, California. First, we made measurements of δ13C and δD of various CH4 sources in urban areas. Fossil fuel CH4 sources (oil refineries, power plants, traffic, and oil drilling fields) had δ13C values between -45 and -30‰ and dD values between -275 and -100‰, whereas biological CH4 (cows, biofuels, landfills, sewage treatment plants, and cattle feedlots) had δ13C values between -65 and -45‰ and δD values between -350 and -275‰. We made high-altitude observations of CH4 concentration using continuous tunable laser spectroscopy measurements combined with isotope analyses (13C, 14C, and D) of discrete samples to constrain urban CH4 sources. Our data indicate that the dominant source of CH4 in Los Angeles has a δ13C value of approximately -41.5‰ and a δD value between -229 and -208‰. Δ14C of CH4 in urban air samples ranged from +262 to +344‰ (127.1 to 134.9 pMC), depleted with respect to average global background CH4. We conclude that the major source of CH4 in Los Angeles is leakage of fossil fuels, such as from geologic formations, natural gas pipelines, oil refining, and/or power plants. More research is needed to constrain fluxes of CH4 from natural gas distribution and refining, as this flux may increase with greater reliance on natural gas and biogas for energy needs.

  2. Comparison of aerodynamically and model-derived roughness lengths (zo) over diverse surfaces, central Mojave Desert, California, USA

    USGS Publications Warehouse

    MacKinnon, D.J.; Clow, G.D.; Tigges, R.K.; Reynolds, R.L.; Chavez, P.S.

    2004-01-01

    The vulnerability of dryland surfaces to wind erosion depends importantly on the absence or the presence and character of surface roughness elements, such as plants, clasts, and topographic irregularities that diminish wind speed near the surface. A model for the friction velocity ratio has been developed to account for wind sheltering by many different types of co-existing roughness elements. Such conditions typify a monitored area in the central Mojave Desert, California, that experiences frequent sand movement and dust emission. Two additional models are used to convert the friction velocity ratio to the surface roughness length (zo) for momentum. To calculate roughness lengths from these models, measurements were made at 11 sites within the monitored area to characterize the surface roughness element. Measurements included (1) the number of roughness species (e.g., plants, small-scale topography, clasts), and their associated heights and widths, (2) spacing among species, and (3) vegetation porosity (a measurement of the spatial distribution of woody elements of a plant). Documented or estimated values of drag coefficients for different species were included in the modeling. At these sites, wind-speed profiles were measured during periods of neutral atmospheric stability using three 9-m towers with three or four calibrated anemometers on each. Modeled roughness lengths show a close correspondence (correlation coefficient, 0.84-0.86) to the aerodynamically determined values at the field sites. The geometric properties of the roughness elements in the model are amenable to measurement at much higher temporal and spatial resolutions using remote-sensing techniques than can be accomplished through laborious ground-based methods. A remote-sensing approach to acquire values of the modeled roughness length is particularly important for the development of linked surface/atmosphere wind-erosion models sensitive to climate variability and land-use changes in areas such

  3. Stable isotopes, Sr/Ca, and Mg/Ca in biogenic carbonates from Petaluma Marsh, northern California, USA

    SciTech Connect

    Ingram, B.L.; De Deckker, P.; Chivas, A.R.; Conrad, M.E.; Byrne, A.R.

    2004-10-19

    Stable isotope ({sup 18}O/{sup 16}O and {sup 13}C/{sup 12}C) and minor-element compositions (Sr/Ca and Mg/Ca ratios) of ostracodes and gastropods separated from marsh sediments from San Francisco Bay, Northern California, were used to reconstruct paleoenvironmental changes in Petaluma Marsh over the past 700 yr. The value of {delta}{sup 18}O in the marsh carbonates reflects changes in freshwater inflow, evaporation, and temperature. Mg/Ca and Sr/Ca in ostracode calcite reflect changes in both freshwater inflow and temperature, although primarily reflect temperature changes in the salinity range of about 10-35 {per_thousand}. Ostracode {delta}{sup 18}O values show a gradual increase by 5 {per_thousand} between 500 yr BR and the present, probably reflecting rising sea level and increased evaporation in the marsh. Superimposed on this trend are higher frequency Mg/Ca and {delta}{sup 18}O variations (3-4 {per_thousand}), probably reflecting changes in freshwater inflow and evaporation. A period of low Mg/Ca occurred between about 100-300 cal yr BP, suggesting wetter and cooler conditions during the Little Ice Age. Higher Mg/Ca ratios occurred 600-700 cal yr BP, indicating drier and warmer conditions during the end of the Medieval Warm Period. Both ostracode and gastropod {delta}{sup 13}C values decrease up-core, reflecting decomposition of marsh vegetation, which changes from C{sub 4} ({delta}{sup 13}C {approx} -12{per_thousand}) to CAM ({delta}{sup 13}C = -26 {per_thousand})-type vegetation over time.

  4. Seismic and aseismic deformations and impact on reservoir permeability: The case of EGS stimulation at The Geysers, California, USA

    NASA Astrophysics Data System (ADS)

    Jeanne, Pierre; Rutqvist, Jonny; Rinaldi, Antonio Pio; Dobson, Patrick F.; Walters, Mark; Hartline, Craig; Garcia, Julio

    2015-11-01

    In this paper, we use the Seismicity-Based Reservoir Characterization approach to study the spatiotemporal dynamics of an injection-induced microseismic cloud, monitored during the stimulation of an enhanced geothermal system, and associated with the Northwest Geysers Enhanced Geothermal System (EGS) Demonstration project (California). We identified the development of a seismically quiet domain around the injection well surrounded by a seismically active domain. Then we compare these observations with the results of 3-D Thermo-Hydro-Mechanical simulations of the EGS, which accounts for changes in permeability as a function of the effective normal stress and the plastic strain. The results of our modeling show that (1) the aseismic domain is caused by both the presence of the injected cold water and by thermal processes. These thermal processes cause a cooling-stress reduction, which prevent shear reactivation and favors fracture opening by reducing effective normal stress and locally increasing the permeability. This process is accompanied by aseismic plastic shear strain. (2) In the seismic domain, microseismicity is caused by the reactivation of the preexisting fractures, resulting from an increase in injection-induced pore pressure. Our modeling indicates that in this domain, permeability evolves according to the effective normal stress acting on the shear zones, whereas shearing of preexisting fractures may have a low impact on permeability. We attribute this lack of permeability gain to the fact that the initial permeabilities of these preexisting fractures are already high (up to 2 orders of magnitude higher than the host rock) and may already be fully dilated by past tectonic straining.

  5. Aquifer-System Characterization by Integrating Data from the Subsurface and from Space, San Joaquin Valley, California, USA

    NASA Astrophysics Data System (ADS)

    Sneed, M.; Brandt, J. T.

    2014-12-01

    Extensive groundwater pumping from the aquifer system in the San Joaquin Valley, California, between 1926 and 1970 caused widespread aquifer-system compaction and resultant land subsidence that locally exceeded 8 m. The importation of surface water in the early 1970s resulted in decreased pumping, recovery of water levels, and a reduced rate of subsidence in some areas. Recently, land-use changes and reductions in surface-water availability have caused pumping to increase, water levels to decline, and subsidence to recur. Reduced freeboard and flow capacity of several Federal, State, and local canals have resulted from this subsidence. Vertical land-surface changes during 2005-14 in the San Joaquin Valley were determined by using space-based [Interferometric Synthetic Aperture Radar (InSAR) and Global Positioning System (GPS)] and subsurface (extensometer) data; groundwater-level and lithologic data were used to understand and estimate properties that partly control the stress/strain response of the aquifer system. Results of the InSAR analysis indicate that two areas covering about 7,200 km2 subsided 20-540 mm during 2008-10; GPS data indicate that these rates continued through 2014. Groundwater levels (stress) and vertical land-surface changes (strain) were used to estimate preconsolidation head and aquifer system storage coefficients. Integrating lithology into the analysis indicates that in some parts of the valley, the compaction occurred primarily within quickly-equilibrating fine-grained deposits in deeper parts of the aquifer system. In other parts of the valley, anomalously fine-grained alluvial-fan deposits underlie one of the most rapidly subsiding areas, indicating the shallow sediments may also contribute to total subsidence. This information helps improve hydrologic and aquifer-system compaction models, which in turn can be used to consider land subsidence as a constraint in evaluating water-resource management options.

  6. Processes governing decadal-scale depositional narrowing of the major tidal channel in San Pablo Bay, California, USA

    NASA Astrophysics Data System (ADS)

    Wegen, M.; Jaffe, B. E.

    2014-05-01

    Bathymetric measurements show that a deep, subtidal channel in San Pablo Bay, California, has consistently narrowed during the past 150 years. This raises general questions on the seasonal and intertidal morphodynamic processes acting at the subtidal channel-shoal interface. The current work addresses these questions using a process-based morphodynamic model (Delft3D). Model results reveal considerable morphodynamic activity during a tidal cycle. Deposition on the channel margin is largest during flooding of the shoals. Erosion rates (mainly occuring during ebb) remain relatively small, so that net accretion occurs on much of the channel margin. A remarkable finding is that locally generated wind waves are responsible for shoal extension and depositional channel narrowing. High suspended sediment concentration (SSC) in the channel is a critical factor. Apart from sediment supply during high river flow, wind waves suspending sediment on the shoals cause high SSC levels in the channel at ebb. Sensitivity analysis shows that wind direction even determines the location of channel margin accretion. Fluvial sediment supply is another cause of high SSC in the channel. Density currents, 3-D circulation flows, sea level rise, or varied sediment characteristics only have a limited effect on the erosion and sedimentation patterns. A 30 year forecast shows that deeper shoals and decreasing fluvial sediment supply lower SSC levels in the channel, limit channel margin accretion, and even lead to net channel margin erosion in some areas. Channel shape thus remains subject to dynamic processes related to local variations in sediment supply, albeit to a more limited extent than in earlier decades.

  7. Luminescence chronologies for sediments recording paleoseismic events and slip rate for the central Garlock fault, California, USA

    NASA Astrophysics Data System (ADS)

    Okubo, S. G.; Wolf, E.; Roder, B. J.; Rhodes, E. J.; McGill, S. F.; Dolan, J. F.; Mcauliffe, L. J.; Lawson, M. J.; Barrera, W. A.

    2012-12-01

    Luminescence dating has a significant role to play in providing chronological control for lacustrine and alluvial sediments that record both tectonic and climatic events. However, poor characteristics in some environments mean that the well-established method of OSL (optically stimulated luminescence) dating of quartz is not well-suited for the material available. In order to overcome this significant limitation, a range of methods based on the IRSL (infra-red stimulated luminescence) and ITL (isothermal thermoluminescence) of K-feldspar are currently under development. The site of El Paso Peaks, California has an established C-14 chronology spanning the last 7,000 years for a series of playa sediments comprising silts and fine sands, with occasional incursions of coarser sands and gravels from the alluvial fan that forms one side of the small ephemeral lake basin. Another barrier is formed by a shutter ridge of the left-lateral central Garlock fault, and this succession of sediments records at least six seismic events. Following collection of a suite of 24 luminescence samples distributed throughout the upper part of this succession, this site provides a rare opportunity to test different luminescence dating protocols in a rigorous fashion. At the site of Christmas Canyon West, a few miles further east, numerous small offsets of depositional and erosional alluvial fan features provide the opportunity to determine slip rates for a variety of timescales spanning the past couple of thousand years, besides forming a record of the timing of several discrete depositional episodes representing local high precipitation events. We review the challenges involved in developing a reliable luminescence chronology for sediment deposition in these contexts, and in relating this chronology to significant environmental events.

  8. EDITORIAL: Proceedings of the 8th International LISA Symposium, Stanford University, California, USA, 28 June-2 July 2010 Proceedings of the 8th International LISA Symposium, Stanford University, California, USA, 28 June-2 July 2010

    NASA Astrophysics Data System (ADS)

    Buchman, Sasha; Sun, Ke-Xun

    2011-05-01

    (CQG) and Journal of Physics: Conference Series (JPCS). The plenary lectures are published in CQG, while most parallel talks and posters are being published in JPCS. At the recommendation of the science organization committee (SOC) other selected work from the conference will also appear in CQG. All papers in CQG have been screened through the journal's regular peer review process. We gratefully acknowledge the support of the CQG and JPCS Publishers and staff for the publication of the proceedings. The symposium and proceedings are generously sponsored by L'Agenzia Spaziale Italiana, the California Institute of Technology, EADS Astrium Germany, the KACST Foundation Saudi Arabia, the LIGO collaboration, the Max-Planck Institute in Potsdam, Germany, NASA, and the National Science Foundation. Stanford University made very significant contributions through the Dean of Research Office, the Department of Applied Physics, the Department of Physics, the Hansen Experimental Physics Laboratory (HEPL), and the SLAC National Accelerator Laboratory. We thank the Stanford local organization committee (LOC), administration and professional staff, KACST engineers, and graduate students for their support of the symposium operations. LISA is one of the most tantalizing yet challenging scientific space missions ever. The 8th International LISA Symposium and publication of the proceedings contribute to its progress. Sasha Buchman and Ke-Xun Sun Stanford University Guest Editors

  9. Direct and indirect costs of rabies exposure: a retrospective study in southern California (1998-2002).

    PubMed

    Shwiff, Stephanie A; Sterner, Ray T; Jay, Michele T; Parikh, Shefali; Bellomy, Amy; Meltzer, Martin I; Rupprecht, Charles E; Slate, Dennis

    2007-04-01

    The direct and indirect costs of suspected human rabies exposure were estimated for San Luis Obispo and Santa Barbara counties, California, USA. Clinic, hospital, and county public health records (1998-2002) were examined to determine direct costs for postexposure prophylaxis (PEP), and 55 (41%) former patients were contacted to voluntarily provide estimates of their indirect costs associated with receiving PEP. Additional costs due to public health and animal control personnel responses to rabid animals were collected, including diagnostic testing and wages. The mean total cost of a suspected human rabies exposure was $3,688, the direct costs per case were $2,564, and the indirect costs were $1,124 of that total. About one third of the total cost for suspected human rabies exposure was attributed to indirect costs (e.g., lost wages, transportation, and day-care fees), most of which were not reimbursable to the patient.

  10. Use of Weighted Regressions on Time, Discharge, and Season to Assess Effectiveness of Agricultural and Environmental Best Management Practices in California and Nevada, USA

    NASA Astrophysics Data System (ADS)

    Domagalski, J. L.; Schlegel, B.; Hutchins, J.

    2014-12-01

    Long-term data sets on stream-water quality and discharge can be used to assess whether best management practices (BMPs) are restoring beneficial uses of impaired water as required under the Clean Water Act. In this study, we evaluated a greater than 20-year record of water quality from selected streams in the Central Valley (CV) of California and Lake Tahoe (California and Nevada, USA). The CV contains a mix of agricultural and urbanized land, while the Lake Tahoe area is mostly forested, with seasonal residents and tourism. Because nutrients and fine sediments cause a reduction in water clarity that impair Lake Tahoe, BMPs were implemented in the early 1990's, to reduce nitrogen and phosphorus loads. The CV does not have a current nutrient management plan, but numerous BMPs exist to reduce pesticide loads, and it was hypothesized that these programs could also reduce nutrient levels. In the CV and Lake Tahoe areas, nutrient concentrations, loads, and trends were estimated by using the recently developed Weighted Regressions on Time, Discharge, and Season (WRTDS) model. Sufficient data were available to compare trends during a voluntary and enforcement period for seven CV sites within the lower Sacramento and San Joaquin Basins. For six of the seven sites, flow-normalized mean annual concentrations of total phosphorus and nitrate decreased at a faster rate during the enforcement period than during the earlier voluntary period. Concentration changes during similar years and ranges of flow conditions suggest that BMPs designed for pesticides also reduced nutrient loads in the CV. A trend analysis using WRTDS was completed for six streams that enter Lake Tahoe during the late 1980's through 2008. The results of the model confirm that nutrient loading is influenced strongly by season, such as by spring runoff from snowmelt. The highest nutrient concentrations in the late 1980's and early 1990's correlate with high flows, followed by statistically significant decreases

  11. In Utero and Early-Life Exposure to Ambient Air Toxics and Childhood Brain Tumors: A Population-Based Case–Control Study in California, USA

    PubMed Central

    von Ehrenstein, Ondine S.; Heck, Julia E.; Park, Andrew S.; Cockburn, Myles; Escobedo, Loraine; Ritz, Beate

    2015-01-01

    to age 6. Citation: von Ehrenstein OS, Heck JE, Park AS, Cockburn M, Escobedo L, Ritz B. 2016. In Utero and early-life exposure to ambient air toxics and childhood brain tumors: a population-based case–control study in California, USA. Environ Health Perspect 124:1093–1099; http://dx.doi.org/10.1289/ehp.1408582 PMID:26505805

  12. Using 10Be erosion rates and fluvial channel morphology to constrain fault throw rates in the southwestern Sacramento River Valley, California, USA

    NASA Astrophysics Data System (ADS)

    Cyr, A. J.

    2013-12-01

    The Sacramento - San Joaquin River Delta, California, USA, is a critical region for California water resources, agriculture, and threatened or endangered species. This landscape is affected by an extensive set of levees that enclose artificial islands created for agricultural use. In addition to their importance for sustaining agriculture, this levee system also supports extensive transport and power transmission infrastructure and urban/suburban development. These levees are susceptible to damage from even moderate ground shaking by either a large earthquake on one of the high-activity faults in the nearby San Francisco Bay region, or even a moderate earthquake on one of the low-activity faults in the Delta region itself. However, despite this danger the earthquake hazards in this region are poorly constrained due to our lack of understanding of faults in and near the Delta region. As part of an effort to better constrain the seismic hazard associated with known, but poorly constrained, faults in the region, a geomorphic analysis of the Dunnigan Hills, northwest of Woodland, CA, is being combined with cosmogenic 10Be catchment-averaged erosion rates. The Dunnigan Hills are a low-relief (maximum elevation 87 m) landscape generated by fault-bend folding above the west-vergent Sweitzer reverse fault that soles into a blind east-vergent reverse fault. These faults have been imaged by seismic reflection data, and local microseismicity indicates that this system is actively propagating to the east. However, the throw rates on the faults in this system remain unconstrained, despite the potential for significant shaking such as that experienced in the nearby April, 1892 earthquake sequence between Winters and Vacaville, Ca, ~25 km to the south, which has been estimated at magnitude 6.0 or greater. Geomorphic and cosmogenic 10Be analyses from 12 catchments draining the eastern flank of the Dunnigan Hills will be used to infer vertical rock uplift rates to better constrain

  13. Coupling Between the Changes in CO2 Concentration and Sediment Biogeochemistry in the Salinas De San Pedro Mudflat, California, USA

    NASA Astrophysics Data System (ADS)

    Rezaie Boroon, M.; Diaz, S.; Torres, V.; Lazzaretto, T.; Dehyn, D.

    2013-12-01

    We investigated the effects of elevated carbon dioxide [CO2] on biogeochemistry of marsh sediment including speciation of selected heavy metals in Salinas de San Pedro mudflat in California. The Salinas de San Pedro mudflat has higher carbon (C) content than the vast majority of fully-vegetated salt marshes even with the higher tidal action in the mudflat. Sources for CO2 were identified as atmospheric CO2 as well as due to local fault degassing process. We measured carbon dioxide [CO2], methane [CH4], total organic carbon, dissolved oxygen, salinity, and heavy metal concentration in various salt marsh locations. Overall, our results showed that CO2 concentration ranging from 418.7 to 436.9 [ppm], which are slightly different in various chambers but are in good agreement with some heavy metal concentrations values in mudflat at or around the same location. The selected metal concentration values (ppm) ranging from 0.003 - 0.011(As); 0.001-0.005 (Cd); 0.04-0.02 (Cr); 0.13-0.38 (Cu); 0.11-0.38 (Pb); 0.0009-0.020 (Se); and 0.188-0.321 (Zn). The low dissolved O2 [ppm] in the pore water sediment indicates suboxic environment. Additionally, CO2 [ppm] and loss on ignition (LOI) [%] correlated inversely; the higher CO2 content, the lower was the LOI; that is to say the excess CO2 may caused higher rates of decomposition and therefore it leads to lower soil organic matter (LOI) [%] on the mudflat surface. It appears that the elevated CO2 makes changes in salt marsh pore water chemistry for instance the free ionic metal (Cu2+, Pb2+, etc.) speciation is one of the most reactive form because simply assimilated by the non-decayed or alive organisms in sediment of salt marsh and/or in water. This means that CO2 not only is a sign of improvement in plant productivity, but also activates microbial decomposition through increases in dissolved organic carbon availability. CO2 also increases acidification processes such as anaerobic degradation of microorganism and oxidation of

  14. Zircon trace element geochemistry and growth of the Pleistocene to Holocene Mono Craters rhyolite magma system, California (USA)

    NASA Astrophysics Data System (ADS)

    Baker, N.; Miller, J. S.; Vazquez, J. A.; Marcaida, M.; Lidzbarski, M. I.

    2015-12-01

    The Mono Craters, part of the Mono-Inyo volcanic chain in eastern California, comprise at least 27 high-silica Pleistocene to Holocene rhyolite domes, lava flows and tephra cones. The Holocene chronology of the Mono Craters is well constrained but only recently has 238U-230Th zircon and 40Ar/39Ar dating elucidated the Pleistocene eruptive history. We performed trace element analysis on dated zircon crystal rims and sectioned interiors (using SHRIMP-RG) from 3 rhyolite domes (21, 12.5, and 7 ka) with additional rim data on 5 ashes separated from juvenile pumice clasts in the correlative Wilson Creek Formation (spanning from 62 to 21 ka). Ti-in-zircon (TTi,zrc) thermometry (titania activity from coexisting Fe-Ti oxides) gives temperatures predominantly between 650°C and 750°C, similar to average zircon saturation temperatures (Tzrc,sat). The observation that Tzrc,sat ≈ TTi,zrc indicates that Mono Craters rhyolite magmas were zircon-saturated and erupted at these temperatures (near water-saturated granite eutectic). Variations in key trace elements are relatively limited overall and zircons display similar REE patterns with generally curved MREE to HREE patterns and prominent negative Eu anomalies. Most of the variation is observed in zircons from older eruptions (62-41 ka). Zircon rims from Ash 17 of the Wilson Creek Formation (59 ka) have elevated Th/U, Eu/Eu*, and Ti and lower Hf compared to Ash 19 (62 ka), which suggests a thermal rejuvenation event between these two eruptions. Zircon rims from Ash 15 (41 ka) are characterized by a trend toward high Hf, at relatively low and relatively constant Ti, and low Eu/Eu*, consistent with rhyolite magma undergoing eutectic-like crystallization just prior to eruption. Zircon surfaces and interiors for the 21, 12.5, and 7 ka dome eruptions have very similar Hf, low Eu/Eu*, low Ti, and low Th/U. This requires zircon crystallization in a very uniform thermal and chemical environment from the latest Pleistocene to Holocene

  15. A Geochemical Exploration of the Sagehen Volcanic Centre, Truckee-Tahoe Region, California, U.S.A

    NASA Astrophysics Data System (ADS)

    Clarke, Christopher Angus Leo

    The assemblage of ca. 6--4 Ma volcanic rocks exposed at the Sagehen Research station in the Truckee-Tahoe region of the northern Sierra Nevada, United States, is interpreted to be, within the Ancestral Cascades volcanic arc, a Lassen-type stratovolcano complex. Sagehen is of particular importance because it is one of the few Tertiary arc volcanic centres in California which has not been heavily glaciated during the Pleistocene. The volcanic rocks are variably porphyritic or aphanitic, including abundant plagioclase with clinopyroxene and amphibole. The rocks range from basalt to basaltic-andesite to andesite in composition. Basalts are olivine- and clinopyroxene-bearing with minor phenocrysts of plagioclase. The basaltic-andesites are primarily pyroxene bearing while the andesites contain pyroxene-, plagioclase- and hornblende porphyritic phases. Sagehen arc lavas are calc-alkaline and enriched in the large ion lithophile elements and depleted in High Field Strength Elements. The basalts are depleted in Zr and Hf while the andesites are enriched with Zr and Hf relative to the middle rare earth elements. Compared to previously studied Ancestral Cascade arc samples, Sagehen region basalts have lower 143Nd/144Nd isotopic values that do not correspond to proposed mantle-lithosphere mixing lines, while the andesite samples appear to represent the interplay of these two components on a 87Sr/ 86Sr vs. 143Nd/144Nd. The trace element data and isotopic plots suggest that the melts that produced the basalts are from subduction modified mantle wedge peridotites that ponded near the base of the lithosphere similar to the generation of other subduction related calc-alkaline lavas along convergent continental margins. The andesitic samples appear to be the result of further modification through crustal assimilation as seen in the higher isotopic Sr contents in the andesites and Ce/Smpmn vs. Tb/Ybpmn plots. Finally, the proposed map units from Sylvester & Raines (2007) were found

  16. Detection of stress in tomatoes induced by late blight disease in California, USA, using hyperspectral remote sensing

    NASA Astrophysics Data System (ADS)

    Zhang, Minghua; Qin, Zhihao; Liu, Xue; Ustin, Susan L.

    2003-11-01

    Large-scale farming of agricultural crops requires on-time detection of diseases for pest management. Hyperspectral remote sensing data taken from low-altitude flights usually have high spectral and spatial resolutions, which can be very useful in detecting stress in green vegetation. In this study, we used late blight in tomatoes to illustrate the capability of applying hyperspectral remote sensing to monitor crop disease in the field scale and to develop the methodologies for the purpose. A series of field experiments was conducted to collect the canopy spectral reflectance of tomato plants in a diseased tomato field in Salinas Valley of California. The disease severity varied from stage 1 (the light symptom), to stage 4 (the sever damage). The economic damage of the crop caused by the disease is around the disease stage 3. An airborne visible infrared imaging spectrometer (AVIRIS) image with 224 bands within the wavelength range of 0.4-2.5 μm was acquired during the growing season when the field data were collected. The spectral reflectance of the field samples indicated that the near infrared (NIR) region, especially 0.7-1.3 μm, was much more valuable than the visible range to detect crop disease. The difference of spectral reflectance in visible range between health plants and the infected ones at stage 3 was only 1.19%, while the difference in the NIR region was high, 10%. We developed an approach including the minimum noise fraction (MNF) transformation, multi-dimensional visualization, pure pixels endmember selection and spectral angle mapping (SAM) to process the hyperspectral image for identification of diseased tomato plants. The results of MNF transformation indicated that the first 28 eigenimages contain useful information for classification of the pixels and the rest were mainly noise-dominated due to their low eigenvalues that had few signals. Therefore, the 28 signal eigenimages were used to generate a multi-dimensional visualization space for

  17. Sources of fecal indicator bacteria to groundwater, Malibu Lagoon and the near-shore ocean, Malibu, California, USA

    USGS Publications Warehouse

    Izbicki, John A.; Swarzenski, Peter W.; Burton, Carmen A.; Van De Werfhorst, Laurie; Holden, Patricia A.; Dubinsky, Eric A.

    2012-01-01

    Onsite wastewater treatment systems (OWTS) used to treat residential and commercial sewage near Malibu, California have been implicated as a possible source of fecal indicator bacteria (FIB) to Malibu Lagoon and the near-shore ocean. For this to occur, treated wastewater must first move through groundwater before discharging to the Lagoon or ocean. In July 2009 and April 2010, δ18O and δD data showed that some samples from water-table wells contained as much as 70% wastewater; at that time FIB concentrations in those samples were generally less than the detection limit of 1 Most Probable Number (MPN) per 100 milliliters (mL). In contrast, Malibu Lagoon had total coliform, Escherichia coli, and enterococci concentrations as high as 650,000, 130,000, and 5,500 MPN per 100 mL, respectively, and as many as 12% of samples from nearby ocean beaches exceeded the U.S. Environmental Protection Agency single sample enterococci standard for marine recreational water of 104 MPN per 100 mL. Human-associated Bacteroidales, an indicator of human-fecal contamination, were not detected in water from wells, Malibu Lagoon, or the near-shore ocean. Similarly, microarray (PhyloChip) data show Bacteroidales and Fimicutes Operational Taxanomic Units (OTUs) present in OWTS were largely absent in groundwater; in contrast, 50% of Bacteroidales and Fimicutes OTUs present in the near-shore ocean were also present in gull feces. Terminal-Restriction Length Fragment Polymorphism (T-RFLP) and phospholipid fatty acid (PLFA) data showed that microbial communities in groundwater were different and less abundant than communities in OWTS, Malibu Lagoon, or the near-shore ocean. However, organic compounds indicative of wastewater (such as fecal sterols, bisphenol-A and cosmetics) were present in groundwater having a high percentage of wastewater and were present in groundwater discharging to the ocean. FIB in the near-shore ocean varied with tides, ocean swells, and waves. Movement of water from

  18. Concentration, UV-spectroscopic characteristics and fractionation of DOC in stormflow from an urban stream, Southern California, USA

    USGS Publications Warehouse

    Izbicki, J.A.; Pimentel, I.M.; Johnson, R.; Aiken, G.R.; Leenheer, J.

    2007-01-01

    The composition of dissolved organic carbon (DOC) in stormflow from urban areas has been greatly altered, both directly and indirectly, by human activities and there is concern that there may be public health issues associated with DOC, which has unknown composition from different sources within urban watersheds. This study evaluated changes in the concentration and composition of DOC in stormflow in the Santa Ana River and its tributaries between 1995 and 2004 using a simplified approach based on the differences in the optical properties of DOC and using operationally defined differences in molecular weight and solubility. The data show changes in the composition of DOC in stormflow during the rainy season and differences associated with runoff from different parts of the basin, including extensive upland areas burned prior to the 2004 rainy season. Samples were collected from the Santa Ana River, which drains ???6950 km2 of the densely populated coastal area of southern California, during 23 stormflows between 1995 and 2004. Dissolved organic carbon (DOC) concentrations during the first stormflows of the ?winter' (November to March) rainy season increased rapidly with streamflow and were positively correlated with increased faecal indicator bacteria concentrations. DOC concentrations were not correlated with streamflow or with other constituents during stormflows later in the rainy season and DOC had increasing UV absorbance per unit carbon as the rainy season progressed. DOC concentrations in stormflow from an urban drain tributary to the river also increased during stormflow and were greater than concentrations in the river. DOC concentrations in stormflow from a tributary stream, draining urban and agricultural land that contained more than 320 000 animals, mostly dairy cows, were higher than concentrations in stormflow from the river and from the urban drain. Fires that burned large areas of the basin before the 2004 rainy season did not increase DOC

  19. Diatom-inferred Holocene record of moisture variability in Lower Bear Lake, San Bernardino Mountains, California, USA

    NASA Astrophysics Data System (ADS)

    Starratt, S.; Kirby, M. E.

    2014-12-01

    Although Holocene diatom records from southern California lakes have been difficult to obtain, diatoms have been found in Lower Bear Lake (LBL) sediments, providing a 9200-year hydroclimatological record for the San Bernardino Mountains. Based on several physical and chemical properties as well as gastropod and ostracod assemblages. Kirby et al. (2012, QSR,46:57-65) inferred nine decadal to multi-centennial pluvial episodes (five major (PE-V to PE-I), four minor (PE-IIIa-c, PE-IIa) in sediment core BBLVC05-1 (34o15'20" N, 116o55'20" W; 4.5 m long). Here, we consider the implications of this new diatom data. The diatom record shows a gradual increase in salinity during the Holocene, corroborating the inference of decreasing lake size made by Kirby et al. (2012). The longest pluvial (PE-V; 9170?-8250 cal yr BP), is dominated by small fragilaroid taxa, indicating fresh, slightly alkaline waters. An increase in halophilic taxa at ~8700 cal yr BP suggests a several-decades-long drier interval within the pluvial. PE-IV (7000-6400 cal yr BP) is dominated by benthic taxa, including relatively high numbers of epiphytic taxa, indicating an increase in aquatic macrophytes. The abundance of Aulacoseira in PE-IV and PE-III (3350-3000 cal yr BP) suggests increased turbulence due to increased storminess. PE-III and PE-II (850-700 cal yr BP) contain greater abundances of benthic (epiphytic) and halophilic species, although the latter never dominate the assemblage. PE-I (500-476 cal yr BP) was not sampled. Aerophilic taxa comprise up to 3% of the assemblage during pluvial events suggesting increased erosion during those periods and the presence of symbiotic species throughout the record indicates nitrogen-depleted waters. The diatom data generally support the occurrence of multiple pluvials over the Holocene with the most sustained occurring in the early Holocene. Furthermore, the diatom data suggest LBL likely diminished in size through the Holocene becoming more saline in the

  20. GPS Instrumentation and Remote Sensing Study of Slow Moving Landslides in the Eastern San Francisco Bay Hills, California, USA

    NASA Astrophysics Data System (ADS)

    Cohen-Waeber, J.; Burgmann, R.; Sitar, N.; Ferretti, A.; Giannico, C.

    2012-12-01

    The objective of this study is to characterize slope deformation as a result of static and dynamic forces, using the most current geodetic technologies that measure active ground surface displacement. Recent advances in geodetic and remote data collection, such as with continuous GPS and Interferometric Synthetic Aperture Radar (InSAR) allow for a level of primary site characterization and eventual risk assessment due to landsliding that was previously not possible. Active landsliding across the Lawrence Berkeley National Laboratory (LBNL) site and the greater Berkeley Hills region, in the Eastern San Francisco Bay, California, has been the object of many investigations over recent decades, though the mechanisms of currently mobile slides are still poorly understood. Previous studies suggest a trend in landslide mobility is closely associated with precipitation and regional active tectonic conditions in addition to the geologic setting (Alan Kropp and Associates, 2002). InSAR time-series analysis has been shown to successfully track creeping landslides in the Berkeley Hills with millimeter scale accuracy (Hilley et al., 2004) and documents displacement primarily during periods of high precipitation (Quigley et al., 2010). However, displacement of creeping landslides due to seismic activity has yet to be measured. A first focus of this project is therefore to study the spatial and temporal distribution of active Berkeley Hills landsliding in relation to local precipitation and ground shaking events by a careful observational program. This program includes the instrumentation of individual landslides with permanent continuously streaming GPS stations (beginning 2012), and regional monitoring of slope surface deformation by InSAR time series analysis (beginning 1992). To date, continuous GPS tracking of select landslides has recorded up to 2 cm of total surface deformation driven by the onset of precipitation, with displacement response times of less than 5 days

  1. Carbon dioxide emissions from vegetation-kill zones around the resurgent dome of Long Valley caldera, eastern California, USA

    USGS Publications Warehouse

    Bergfeld, Deborah; Evans, William C.; Howle, James F.; Farrar, Christopher D.

    2006-01-01

    A survey of diffuse CO2 efflux, soil temperature and soil-gas chemistry over areas of localized vegetation-kill on and around the resurgent dome of Long Valley caldera California was performed to evaluate the premise that gaseous and thermal anomalies are related to renewed intrusion of magma. Some kill sites are long-lived features and others have developed in the past few years. Total anomalous CO2 emissions from the thirteen areas average around 8.7 t per day; but the majority of the emissions come from four sites west of the Casa Diablo geothermal power plant. Geochemical analyses of the soil-gases from locations west and east of the plant revealed the presence of isobutane related to plant operations. The δ13C values of diffuse CO2 range from − 5.7‰ to − 3.4‰, similar to values previously reported for CO2 from hot springs and thermal wells around Long Valley.At many of the vegetation-kill sites soil temperatures reach boiling at depths ≤ 20 cm. Soil temperature/depth profiles at two of the high-emissions areas indicate that the conductive thermal gradient in the center of the areas is around 320 °C m− 1. We estimate total heat loss from the two areas to be about 6.1 and 2.3 MW. Given current thinking on the rate of hydrothermal fluid flow across the caldera and using the CO2 concentration in the thermal fluids, the heat and CO2 loss from the kill areas is easily provided by the shallow hydrothermal system, which is sourced to the west of the resurgent dome. We find no evidence that the development of new areas of vegetation kill across the resurgent dome are related to new input of magma or magmatic fluids from beneath the resurgent dome. Our findings indicate that the areas have developed as a response to changes in the shallow hydrologic system. Some of the changes are likely related to fluid production at the power plant, but at distal sites the changes are more likely related to seismicity and uplift of the dome.

  2. Carbon dioxide emissions from vegetation-kill zones around the resurgent dome of Long Valley caldera, eastern California, USA

    NASA Astrophysics Data System (ADS)

    Bergfeld, Deborah; Evans, William C.; Howle, James F.; Farrar, Christopher D.

    2006-04-01

    A survey of diffuse CO 2 efflux, soil temperature and soil-gas chemistry over areas of localized vegetation-kill on and around the resurgent dome of Long Valley caldera California was performed to evaluate the premise that gaseous and thermal anomalies are related to renewed intrusion of magma. Some kill sites are long-lived features and others have developed in the past few years. Total anomalous CO 2 emissions from the thirteen areas average around 8.7 t per day; but the majority of the emissions come from four sites west of the Casa Diablo geothermal power plant. Geochemical analyses of the soil-gases from locations west and east of the plant revealed the presence of isobutane related to plant operations. The δ13C values of diffuse CO 2 range from - 5.7‰ to - 3.4‰, similar to values previously reported for CO 2 from hot springs and thermal wells around Long Valley. At many of the vegetation-kill sites soil temperatures reach boiling at depths ≤ 20 cm. Soil temperature/depth profiles at two of the high-emissions areas indicate that the conductive thermal gradient in the center of the areas is around 320 °C m - 1 . We estimate total heat loss from the two areas to be about 6.1 and 2.3 MW. Given current thinking on the rate of hydrothermal fluid flow across the caldera and using the CO 2 concentration in the thermal fluids, the heat and CO 2 loss from the kill areas is easily provided by the shallow hydrothermal system, which is sourced to the west of the resurgent dome. We find no evidence that the development of new areas of vegetation kill across the resurgent dome are related to new input of magma or magmatic fluids from beneath the resurgent dome. Our findings indicate that the areas have developed as a response to changes in the shallow hydrologic system. Some of the changes are likely related to fluid production at the power plant, but at distal sites the changes are more likely related to seismicity and uplift of the dome.

  3. Water movement through a thick unsaturated zone underlying an intermittent stream in the western Mojave Desert, southern California, USA

    USGS Publications Warehouse

    Izbicki, J.A.; Radyk, J.; Michel, R.L.

    2000-01-01

    Previous studies indicated that small amounts of recharge occur as infiltration of intermittent streamflow in washes in the upper Mojave River basin, in the western Mojave Desert, near Victorville, California. These washes flow only a few days each year after large storms. To reach the water table, water must pass through an unsaturated zone that is more than 130 m thick. Results of this study, done in 1994-1998, showy that infiltration to depths below the root zone did not occur at control sites away from the wash. At these sites, volumetric water contents were as low as 0.01 and water potentials (measured as the combination of solute and matric potentials using a water activity meter) were as negative as -14,000 kPa. Water-vapor movement was controlled by highly negative solute potentials associated with the accumulation of soluble salts in the unsaturated zone. Highly negative matric potentials above and below the zone of maximum solute accumulation result from movement of water vapor toward the highly negative solute potentials at that depth. The ??18O and ??D (delta oxygen-18 and delta deuterium) isotopic composition of water in coarse-grained deposits plots along a Rayleigh distillation line consistent with removal of water in coarse-grained layers by vapor transport. Beneath Oro Grande Wash, water moved to depths below the root zone and, presumably, to the water table about 130 m below land surface. Underneath Oro Grande Wash, volumetric water contents were as high as 0.27 and water potentials (measured as matric potential using tensiometers) were between -1.8 and -50 kPa. On the basis of tritium data, water requires at least 180-260 years to infiltrate to the water table. Clay layers impede the downward movement of water. Seasonal changes in water vapor composition underneath the wash are consistent with the rapid infiltration of a small quantity of water to great depths and subsequent equilibration of vapor with water in the surrounding material. It may be

  4. Distribution of Xantus' Murrelet Synthliboramphus hypoleucus at sea in the Southern California Bight, 1995-97

    USGS Publications Warehouse

    Whitworth, Darrell L.; Takekawa, John Y.; Carter, Harry R.; Newman, Scott H.; Keeney, Thomas W.; Kelly, Paul R.

    2000-01-01

    We radiomarked 153 Xantus' Murrelets Synthliboramphus hypoleucus captured at sea near Santa Barbara Island (SBI), the largest murrelet colony in the California Channel Islands, USA. We tracked these radiomarked murrelets in the Southern California Bight (SCB) off coastal southern California during the 1995-97 breeding seasons. In 1995 during mild El Nino conditions, the murrelets were distributed in non-upwelling areas. In 1996-97, they were distributed in dense patches, aggregating in cool upwelled waters near the northern Channel Islands or south of San Nicolas Island. Murrelets flew longer distances from SBI to foraging areas in 1997 (x?? = 111 ?? 44 km) than in 1996 (x?? = 62 ?? 25 km), but the distances they travelled did not differ between months (Apr and May) within years. Mean foraging distances from SBI were similar for 'incubating' murrelets (determined on the basis of repeated visits to SBI) and 'non-incubating' murrelets during the colony attendance period. We attributed the low return rate of radiomarked murrelets to SBI to the capture and marking of a large proportion of birds that were not actively incubating rather than to any adverse effects of radio attachment. We believe changes in murrelet foraging patterns between the 1970s and 1990s are associated with changes in prey resources in the SCB. Flexibility in the foraging strategies of these murrelets may be related to the highly variable marine environment at the southern end of the California Current Upwelling System.

  5. Radiolarian indicators of El Nino and anti-El Nino events in Holocene sediments of Santa Barbara basin

    SciTech Connect

    Weinheimer, A.L.

    1986-04-01

    Radiolarian distributions and physical oceanographic data from the Santa Barbara basin indicate the following. Strong anti-El Nino periods can be characterized by (1) intermediate radiolarian density, (2) high percentage of transition-central radiolarian fauna, and (3) low percentage and number of warm-water radiolarian fauna. This distribution pattern is attributed to strong wind-driven upwelling and reduced northward transport by the California Countercurrent during anti-El Nino periods. Strong El Nino periods are typically (1) high in radiolarian density, and (2) low in percentage but high in number of warm-water fauna. This distribution is attributed to reduced wind-driven upwelling, enhanced northward countercurrent transport, and geostrophic doming of the cold-water masses in the shear zone between the California Current and California Countercurrent.

  6. Changes in production and respiration during a spring phytoplankton bloom in San Francisco Bay, California, USA: Implications for net ecosystem metabolism

    USGS Publications Warehouse

    Caffrey, J.M.; Cloern, J.E.; Grenz, C.

    1998-01-01

    We present results of an intensive sampling program designed to measure weekly changes in ecosystem respiration (oxygen consumption in the water column and sediments) around the 1996 spring bloom in South San Francisco Bay, California, USA. Measurements were made at a shallow site (2 m, where mean photic depth was 60% of the water column height) and a deep site (15 m, mean photic depth was only 20% of the water column). We also estimated phytoplankton primary production weekly at both sites to develop estimates of net oxygen flux as the sum of pelagic production (PP), pelagic respiration (PR) and benthic respiration (BR). Over the 14 wk period from February 5 to May 14, PP ranged from 2 to 210, PR from 9 to 289, and BR from 0.1 to 48 mmol O2 m-2 d-1, illustrating large variability of estuarine oxygen fluxes at the weekly time scale. Pelagic production exceeded total respiration at the shallow site, but not at the deep site, demonstrating that the shallow domains are net autotrophic but the deep domains are net heterotrophic, even during the period of the spring bloom. If we take into account the potential primary production by benthic microalgae, the estuary as a whole is net autotrophic during spring, net heterotrophic during the nonbloom seasons, and has a balanced net metabolism over a full annual period. The seasonal shift from net autotrophy to heterotrophy during the transition from spring to summer was accompanied by a large shift from dominance by pelagic respiration to dominance by benthic respiration. This suggests that changes in net ecosystem metabolism can reflect changes in the pathways of energy flow in shallow coastal ecosystems.

  7. Mercury concentrations in blood and feathers of prebreeding Forster's terns in relation to space use of San Francisco Bay, California, USA, habitats

    USGS Publications Warehouse

    Ackerman, J.T.; Eagles-Smith, C. A.; Takekawa, J.Y.; Bluso, J.D.; Adelsbach, T.L.

    2008-01-01

    We examined mercury concentrations and space use of prebreeding Forster's terns (Sterna forsteri) in San Francisco Bay, California, USA, to assess factors influencing mercury levels in piscivorous birds. In 2005 and 2006, we collected blood and feathers from 122 Forster's terns and radio-marked and tracked 72 terns to determine locations of dietary mercury uptake. Capture site and capture date were the most important factors explaining variation in blood mercury concentrations (geometric mean ?? standard error: 1.09 ?? 0.89 ??g/g wet wt), followed by sex and year. Accordingly, radiotelemetry data revealed that Forster's terns generally remained near their site of capture and foraged in nearby salt ponds, managed and tidal marshes, and tidal flats. In contrast, capture site and capture date were not important factors explaining variation in feather mercury concentrations, probably because feathers were grown on their wintering grounds several months prior to our sampling. Instead, sex and year were the most important factors explaining mercury concentrations in breast feathers (9.57 ?? 8.23 ??g/g fresh wt), and sex was the most important factor for head feathers (6.94 ?? 7.04 ??g/g fresh wt). Overall, 13 and 22% of prebreeding Forster's terns were estimated to be at high risk for deleterious effects due to mercury concentrations in blood (>3.0 ??g/g wet wt) and feathers (>20.0 ??g/g fresh wt), respectively. Breeding terns are likely to be even more at risk because blood mercury concentrations more than tripled during the 45-d prebreeding time period. These data illustrate the importance of space use and tissue type in interpreting mercury concentrations in birds. ?? 2008 SETAC.

  8. New Peak Temperature Constraints Using RSCM Geothermometry on Lucia Subterrane in Franciscan Complex (California, USA): Detection of Thermal Anomalies in Gold-Bearing Quartz Veins Surrounding.

    NASA Astrophysics Data System (ADS)

    Lahfid, A.; Delchini, S.; Lacroix, B.

    2015-12-01

    The occurrence of deposits hosted by carbonaceous materials-rich metasediments is widespread. Therefore, we aims in this study to investigate the potential of the Raman Spectroscopy of Carbonaceous Material (RSCM) geothermometry to detect thermal anomalies in hydrothermal ore deposits environment and to demonstrate the ability of warm fluids, migrating through the sedimentary sequence to locally disturb the thermal gradient and associated peak temperatures. For this purpose, we have chosen the Lucia subterrane in the Franciscan Complex (California, USA), which includes gold-bearing quartz veins that witness a hydrothermal overprint (Underwood et al., 1995).The sediments in this zone essentially comprise greywacke and shale-matrix mélange (e.g. Frey and Robinson, 1999), which have undergone high-pressure, low-temperature metamorphism. The thermal history of the Lucia subterrane has been previously proposed by Underwood et al. (1995), essentially using vitrinite reflectance method (Rm). Rm values increase from the south to the north; they vary between 0.9 and 3.7 % (~150-280°C). All these results suggest that the Lucia subterrane underwent a regional increase of thermal gradient toward the north. Anomalous Rm values from 4.5% to 4.9% (~305-315°C) are recorded near Cape San Martin. These highest temperatures estimated are likely, associated with a late hydrothermal event (Underwood et al., 1995). Estimated Raman temperatures 1) confirmed the increase in the metamorphic grade towards the north already shown by Underwood et al. (1995), using classical methods like mineralogy and vitrinite reflectance and 2) exhibit anomalous values (temperatures reach 350°C). These anomalies are probably due to the later hydrothermal event. This result suggests that RSCM could be used as a reliable tool to determine thermal anomalies caused by hot fluid-flow.

  9. The Impact of Climatological Variables on Kelp Canopy Area in the Santa Barbara Channel

    NASA Astrophysics Data System (ADS)

    Zigner, K.; Bausell, J.; Kudela, R. M.

    2015-12-01

    Kelp canopy area (KCA), a proxy for kelp forest health, has important implications for small and large-scale processes pertaining to fisheries, near shore currents, and marine ecosystems. As part of the NASA Airborne Science Research Program (SARP), this study examines the impact of ocean chemistry and climatological variables on KCA in the Santa Barbara Channel through time series analysis. El Niño Southern Oscillation (ENSO), North Pacific Gyre Oscillation (NPGO), North Pacific Oscillation (NPO), and upwelling indices as well as sea surface temperature (SST), salinity, nitrate, and chlorophyll-a concentrations taken within the Santa Barbara channel (1990-2014) were acquired from the Climate Prediction Center (CPC), California Cooperative Oceanic Fisheries Investigation (CalCOFI), and Di Lorenzo's NPGO websites. These data were then averaged for winter (November-January) and summer (May-August) seasons and compared to KCA measurements derived from Landsat images via unsupervised classification. Regression, cumulative sum tests, and cross-correlation coefficients revealed a two year lag between KCA and the NPGO, indicating the presence of an additional factor driving both variables. Further analyses suggests that the NPO may be this driving factor, as indicated by the correlation (lag 0) with KCA. Comparing relationships between kelp and other variables over various time periods supports the acceleration of the NPGO and other variables in more recent years. Exploring relationships between KCA, NPGO, and NPO may provide insight into potential impacts of climate change on coastal marine ecosystems.

  10. Sediment scour and deposition within harbors in California (USA), caused by the March 11, 2011 Tohoku-oki tsunami

    NASA Astrophysics Data System (ADS)

    Wilson, Rick; Davenport, Clif; Jaffe, Bruce

    2012-12-01

    Tsunamis have caused significant damage to boats and docks within harbors and ports along the California coast. Sediment scour and deposition within harbors by tsunamis, though not extensively studied, have produced long-term impacts to the recovery and resiliency of affected maritime communities. The March 11, 2011 Tohoku-oki teletsunami generated strong tsunami currents (up to 7 m/s, or 14 kn) within Crescent City and Santa Cruz harbors that triggered sedimentation problems, regulatory issues with sediment disposal, and months of delays in the reconstruction process. Evaluation of video, pre- and post-tsunami bathymetric surveys, and harbor sediment analysis data helped develop a better understanding of tsunami flow regime and sediment transport within these harbors. In Crescent City, the scour effects of large tsunami surges were amplified by the narrow entrance to the Small-Boat Basin, increasing the sediment supply and trapping this material within the basin, causing shoaling that made the harbor unusable and creating long-term disposal issues. Within the entire harbor, at least 289,400 m3 of sediment was scoured in an area of 0.67 km2. A minimum fill volume of 154,600 m3 was calculated with the sediment covering 55% of that portion of the harbor included in the bathymetric surveys. In Santa Cruz, the long, constricting layout and shallow nature of the harbor increased current velocities and scour in confined areas, and exacerbated sedimentation in between and beneath docks. At the harbor entrance, estimated scour volumes range from 2550 to 14,800 m3, and fill estimates range from 120 to 8750 m3, depending upon the surveys used to characterize post-tsunami conditions, while the area of deposition ranges from 6 to 64% of the survey overlap areas. About 83 m3 of sediment was scoured in Santa Cruz North Harbor, while a minimum of 75 m3 was deposited across 50% of that portion of the harbor common to pre- and post-tsunami surveys. Fill estimates are considered

  11. Patterns of volcanism, weathering, and climate history from high-resolution geochemistry of the BINGO core, Mono Lake, California, USA

    NASA Astrophysics Data System (ADS)

    Zimmerman, S. R.; Starratt, S.; Hemming, S. R.

    2012-12-01

    Mono Lake, California is a closed-basin lake on the east side of the Sierra Nevada, and inflow from snowmelt dominates the modern hydrology. Changes in wetness during the last glacial period (>12,000 years ago) and over the last 2,000 years have been extensively described, but are poorly known for the intervening period. We have recovered a 6.25 m-long core from ~3 m of water in the western embayment of Mono Lake, which is shown by initial radiocarbon dates to cover at least the last 10,000 years. The sediments of the core are variable, ranging from black to gray silts near the base, laminated olive-green silt through the center, to layers of peach-colored carbonate nodules interbedded with gray and olive silts and pea-green organic ooze. Volcanic tephras from <1 to 8 cm thick occur throughout. Results of 0.5 cm-resolution scanning-X-Ray fluoresence (XRF) analysis describe changes in lithology due to volcanism, erosion, and changing lake level and chemistry. Titanium (Ti) is chemically and biologically unreactive, and records the dominant input, from weathering of Sierra Nevada granite to the west and Miocene and Pliocene volcanic rocks of the Bodie and Adobe Hills to the north, east, and south. The rhyolitic tephras of the Mono-Inyo Craters are much lower in TiO2 than the bedrock (<0.1% vs. 1-2%), and are an unweathered source of K2O (3.5-5%), and thus form dramatic peaks in the K/Ti ratio. Calcium (Ca) and Sr are well correlated throughout the core, and normalization of both by K (detritus + tephra) corresponds with occurrence of carbonate-rich layers. These are a mixture of authigenic precipitates directly precipitated and eroded into the lake during periods of regression. The lowermost 1.5 m of the BINGO core contains the highest proportion of detrital input to Mono Lake over the last ~12,000 years, recorded by high Si, Ti, K, and Fe, in black to dark-gray, fine-grained silts above 10 cm of pure light gray silt. Based on radiocarbon dates of >10,000 calibrated

  12. Wetland Plant Physiology Exhibits Controls on Carbon Sequestration Processes in a Restored Temperate Peatland of California, USA

    NASA Astrophysics Data System (ADS)

    Windham-Myers, L.; Byrd, K. B.; Khanna, S.; Miller, R.; Anderson, F.

    2011-12-01

    Wetland soils, especially peatlands, serve as the leading long-term sink of carbon (C) in the terrestrial biosphere, representing ~5% of global terrestrial ecosystem acreage but ~25% of total stored terrestrial organic C. While inhibition of microbial respiration rates is a necessary component of peat formation, plant processes regulate gross and net organic matter production (GPP and NPP) and microbial respiration in the rhizosphere. Recent work in a 14-year-old, 6-ha experimental wetland complex in the California's Sacramento-San Joaquin Delta has documented that continuous flooding at 25 cm depth can generate peat growth averaging 1 kg C m-2 y-1, and elevation gains approaching 4 cm y-1, 40-fold greater than historic rates tied to mean sea level rise (1mm y-1). To determine macrophyte controls on organic matter production and respiration in emergent marsh habitats, plant physiological processes were examined for 3 dominant species: hardstem bulrush (Schoenoplectus acutus), narrowleaf and broadleaf cattail (Typha angustifolia and T. latifolia). Leaf-level photosynthetic rates (GPP) were collected monthly with a LiCor 6400XT in May-September of 2010 and 2011 across a gradient of water residence time. GPP, stomatal conductance, photosynthetically active radiation (PAR), relative humidity and leaf temperatures were assessed from pre-dawn to solar-noon to assess light-use (LUE) and water-use efficiency (WUE) for carbon assimilation (A). CO2 levels (Ci) were regulated to generate A-Ci curves, indicating leaf capacity to assimilate recycled CO2. Porewater acetate concentrations and live root concentrations of ethanol and acetaldehyde were assayed seasonally in 2011 as relative indices of fermentative respiration. Plant species distribution, NPP and leaf-area indices (LAI) were calculated using allometric relationships, and used to scale-up leaf-level GPP estimates, as well as to ground-truth high-resolution CIR imagery, to compare NDVIs with recent hyperspectral data

  13. Phase-equilibrium geobarometers for silicic rocks based on rhyolite-MELTS—Part 3: Application to the Peach Spring Tuff (Arizona-California-Nevada, USA)

    NASA Astrophysics Data System (ADS)

    Pamukcu, Ayla S.; Gualda, Guilherme A. R.; Ghiorso, Mark S.; Miller, Calvin F.; McCracken, Reba G.

    2015-03-01

    Establishing the depths of magma accumulation is critical to understanding how magmas evolve and erupt, but developing methods to constrain these pressures is challenging. We apply the new rhyolite-MELTS phase-equilibria geobarometer—based on the equilibrium between melt, quartz, and two feldspars—to matrix glass compositions from Peach Spring Tuff (Arizona-California-Nevada, USA) high-silica rhyolite. We compare the results to those from amphibole geothermobarometry, projection of glass compositions onto the haplogranitic ternary, and glass SiO2 geobarometry. Quartz + 2 feldspar rhyolite-MELTS pressures span a relatively small range (185-230 MPa), consistent with nearly homogeneous crystal compositions, and are similar to estimates based on projection onto the haplogranitic ternary (250 ± 50 MPa) and on glass SiO2 (255-275 MPa). Amphibole geothermobarometry gives much wider pressure ranges (temperature-independent: ~65-300 MPa; temperature-dependent: ~75-295 MPa; amphibole-only: ~80-950 MPa); average Anderson and Smith (Am Mineral 80:549-559, 1995) + Blundy and Holland (Contrib Miner Petrol 104:208-224, 1990) or Holland and Blundy (Contrib Miner Petrol 116:433-447, 1994—Thermometer A, B) pressures are most similar to phase-equilibria results (~220, 210, 190 MPa, respectively). Crystallization temperatures determined previously with rhyolite-MELTS (742 °C), Zr-in-sphene (769 ± 20 °C), and zircon saturation (770-780 °C) geothermometry are similar, but temperatures from amphibole geothermometry (~450-955 °C) are notably different; the average Anderson and Smith + Holland and Blundy (1994—Thermometer B; ~710 °C) temperature is most consistent with previous estimates. The rhyolite-MELTS geobarometer effectively culls glass compositions affected by alteration or analytical issues; Peach Spring glass compositions that yield pressure estimates reveal a tight range of plausible Na2O and K2O contents, suggesting that low Na2O and high K2O contents of many

  14. Uranium in Holocene valley-fill sediments, and uranium, radon, and helium in waters, Lake Tahoe-Carson Range area, Nevada and California, U.S.A.

    USGS Publications Warehouse

    Otton, J.K.; Zielinski, R.A.; Been, J.M.

    1989-01-01

    Uraniferous Holocene sediments occur in the Carson Range of Nevada and California, U.S.A., between Lake Tahoe and Carson Valley. The hosts for the uranium include peat and interbedded organic-rich sand, silt, and mud that underly valley floors, fens, and marshes along stream valleys between the crest of the range and the edge of Lake Tahoe. The known uranium accumulations extend along the Carson Range from the area just southeast of South Lake Tahoe northward to the area just east of Carson City; however, they almost certainly continue beyond the study area to the north, west, and south. Due to the young age of the accumulations, uranium in them is in gross disequilibrium with its highly radioactive daughter products. These accumulations have thus escaped discovery with radiation detection equipment in the past. The uranium content of these sediments approaches 0.6 percent; however, the average is in the range of 300-500 ppm. Waters associated with these sediments locally contain as much as 177 ppb uranium. Modest levels of helium and radon also occur in these waters. Uraniferous waters are clearly entering the private and public water supply systems in some parts of the study area; however, it is not known how much uranium is reaching users of these water supplies. Many of the waters sampled in the study area exceed the published health effects guidance level of the Environmental Protection Agency. Regulatory standards for uranium in waters have not been published, however. Much uranium is stored in the sediments along these stream valleys. Estimates for a marsh and a fen along one drainage are 24,000 and 15,000 kg, respectively. The potential effects of man-induced environmental changes on the uranium are uncertain. Laboratory studies of uraniferous sediment rich in organic matter may allow us to evaluate the potential of liberating uranium from such sediments and creating transient increases in the level of uranium moving in water in the natural environment

  15. Tectonic geomorphology and volcano-tectonic interaction in the eastern boundary of the Southern Cascades (Hat Creek Graben region), California, USA

    NASA Astrophysics Data System (ADS)

    Paguican, Engielle Mae; Bursik, Marcus

    2016-07-01

    The eastern boundary of the Southern Cascades (Hat Creek Graben region), California, USA, is an extensively faulted volcanic corridor between the Cascade Range and Modoc Plateau. The east-west extending region is in the transition zone between the convergence and subduction of the Gorda Plate underneath the North American Plate; north-south shortening within the Klamath Mountain region; and transcurrent movement in the Walker Lane. We describe the geomorphological and tectonic features, their alignment and distribution, in order to understand the tectonic geomorphology and volcano-tectonic relationships. One outcome of the work is a more refined morpho-structural description that will affect future hazard assessment in the area. A database of volcanic centers and structures was created from interpretations of topographic models generated from satellite images. Volcanic centers in the region were classified by morphological type into cones, sub-cones, shields and massifs. A second classification by height separated the bigger and smaller edifices and revealed an evolutionary trend. Poisson Nearest Neighbor analysis shows that bigger volcanoes are spatially dispersed while smaller ones are clustered. Using volcano centroid locations, about 90 lineaments consisting of at least three centers within 6km of one another were found, revealing that preferential north-northwest directed pathways control the transport of magma from the source to the surface, consistent with the strikes of the major fault systems. Most of the volcano crater openings are perpendicular to the maximum horizontal stress, expected for extensional environments with dominant normal regional faults. These results imply that the extension of the Hat Creek Graben region and impingement of the Walker Lane is accommodated mostly by extensional faults and partly by the intrusions that formed the volcanoes. Early in the history of a volcano or volcano cluster, melt produced at depth in the region propagates

  16. Fine Resolution Tree Height Estimation from Lidar Data and Its Application in SRTM DEM Correction across Forests of Sierra Nevada, California, USA

    NASA Astrophysics Data System (ADS)

    Su, Y.; Guo, Q.; Ma, Q.; Li, W.

    2015-12-01

    Sierra Nevada (SN) is a mountain range located in the northeastern California, USA, covering an area of 63,100 km2. As one of the most diverse temperate conifer forests on the Earth, forests of SN serve a series of ecosystem functions and are valuable natural heritages for the region and even the country. The still existed gap of accurate fine-resolution tree height estimation has lagged ecological, hydrological and forestry studies within the region. Moreover, the Shuttle Radar Topography Mission (SRTM) digital elevation model (DEM), as one of the most frequently used land surface elevation product in the region, has been proved systematically higher than actual land surface in vegetated mountain areas due to the absorption and reflection effects of canopy on the SRTM radar signal. An accurate fine resolution tree height product across the region is urgently needed for developing models to correct SRTM DEM. In this study, we firstly developed a method to estimate SN tree height distribution (defined by Lorey's height) through the combination of airborne lidar data, spaceborne lidar data, optical imagery, climate surfaces, and field measurements. Over 5 470 km2airborne lidar data and 1 000 plot measurements were collected across the SN to address this mission. Our method involved three main steps: 1) estimate tree heights within airborne lidar footprints using step-wise regression; 2) link the airborne lidar derived tree height to spaceborne lidar data and compute tree heights at spaceborne lidar footprints; 3) extrapolate tree height estimation from spaceborne lidar footprints to the whole region using Random Forest. The obtained SN tree height product showed good correspondence with independent field plot measurements. The coefficient of determination is higher than 0.65, and the root-mean-square error is around 5 m. With the obtained tree height product, we further explored the possibility of correcting SRTM DEM. The results showed that the obtained tree height

  17. Barbara Bodichon's Travel Writing: Her Epistolary Articulation of "Bildung"

    ERIC Educational Resources Information Center

    Simon-Martin, Meritxell

    2016-01-01

    English painter Barbara Bodichon received a dynamic home education, consisting of engaging lessons, reading sessions, family discussions, sketching excursions, and trips at home and abroad. As an adult, Bodichon led a nomadic life, living between Algeria and England and travelling across Europe and America. Seeking to unpack travelling and travel…

  18. 27 CFR 9.217 - Happy Canyon of Santa Barbara.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Happy Canyon of Santa... Areas § 9.217 Happy Canyon of Santa Barbara. (a) Name. The name of the viticultural area described in this section is “Happy Canyon of Santa Barbara”. For purposes of part 4 of this chapter, “Happy...

  19. Santa Barbara City College: 2002-05 College Plan.

    ERIC Educational Resources Information Center

    Santa Barbara City Coll., CA.

    This document summarizes the Santa Barbara City College 2002-2005 College Plan. The plan's goals are: (1) to develop and implement strategies to increase assistance to students in identifying learning needs and defining educational, career, and life goals; (2) to increase the percentage of students attaining educational goals; (3) to increase…

  20. The Quintessential Searcher: The Wit & Wisdom of Barbara Quint.

    ERIC Educational Resources Information Center

    Block, Marylaine, Ed.

    This book presents selected writings by Barbara Quint (BQ) on online searching. The selections are organized into the following chapters: (1) "The Art of Searching," including finding out what the patron wants, preparing for the search, knowing when the search is done, search styles, rules of online searching, cost issues, Quint's Laws,…

  1. Barbara Thayer-Bacon on Knowers and the Known

    ERIC Educational Resources Information Center

    McKenzie, Jim

    2002-01-01

    Barbara Thayer-Bacon (1999) objects to the minimum proficiency examinations that are mandated for school students in Ohio. Similar tests are required by, or are under consideration by, governments in many other parts of the world. Various writers have objected to one or other of these tests by arguing that they are crude, invalid, unreliable,…

  2. 33 CFR 167.450 - In the Santa Barbara Channel Traffic Separation Scheme: General.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false In the Santa Barbara Channel... Barbara Channel Traffic Separation Scheme: General. The Traffic Separation Scheme in the Santa Barbara Channel is described in §§ 167.451 and 167.452. The geographic coordinates in §§ 167.451 and 167.452...

  3. Effect of localizing fruit and vegetable consumption on greenhouse gas emissions and nutrition, Santa Barbara County.

    PubMed

    Cleveland, David A; Radka, Corie N; Müller, Nora M; Watson, Tyler D; Rekstein, Nicole J; Wright, Hannah Van M; Hollingshead, Sydney E

    2011-05-15

    The US agrifood system is very productive, but highly centralized and resource intensive with very weak links between production and consumption. This contributes to high levels of malnutrition and greenhouse gas emissions (GHGE). A popular approach to improvement is localization-reducing direct transport (farm to retail distance, or "food miles"). We examined Santa Barbara County (SBC) California, which mirrors the high production, nutritional and environmental problems, and growing localization movement of California. SBC ranks in the top 1% of US counties in value of agricultural products, and >80% of this value is produce (fruits and vegetables). We calculated the amount of produce grown in and consumed in SBC and estimated that >99% of produce grown in SBC is exported from the county, and >95% of produce consumed in SBC is imported. If all produce consumed in SBC was grown in the county (100% localization), it would reduce GHGE from the agrifood system <1%, and not necessarily affect nutrition. While food miles capture only a portion of the environmental impact of agrifood systems, localization could be done in ways that promote synergies between improving nutrition and reducing GHGE, and many such efforts exist in SBC.

  4. Initial source and site characterization studies for the U.C. Santa Barbara campus

    SciTech Connect

    Archuleta, R.; Nicholson, C.; Steidl, J.; Gurrola, L.; Alex, C.; Cochran, E.; Ely, G.; Tyler, T.

    1997-12-01

    The University of California Campus-Laboratory Collaboration (CLC) project is an integrated 3 year effort involving Lawrence Livermore National Laboratory (LLNL) and four UC campuses - Los Angeles (UCLA), Riverside (UCR), Santa Barbara (UCSB), and San Diego (UCSD) - plus additional collaborators at San Diego State University (SDSU), at Los Alamos National Laboratory and in industry. The primary purpose of the project is to estimate potential ground motions from large earthquakes and to predict site-specific ground motions for one critical structure on each campus. This project thus combines the disciplines of geology, seismology, geodesy, soil dynamics, and earthquake engineering into a fully integrated approach. Once completed, the CLC project will provide a template to evaluate other buildings at each of the four UC campuses, as well as provide a methodology for evaluating seismic hazards at other critical sites in California, including other UC locations at risk from large earthquakes. Another important objective of the CLC project is the education of students and other professional in the application of this integrated, multidisciplinary, state-of-the-art approach to the assessment of earthquake hazard. For each campus targeted by the CLC project, the seismic hazard study will consist of four phases: Phase I - Initial source and site characterization, Phase II - Drilling, logging, seismic monitoring, and laboratory dynamic soil testing, Phase III - Modeling of predicted site-specific earthquake ground motions, and Phase IV - Calculations of 3D building response. This report cover Phase I for the UCSB campus and incudes results up through March 1997.

  5. Large-Scale Multi-Objective Optimization for the Management of Seawater Intrusion, Santa Barbara, CA

    NASA Astrophysics Data System (ADS)

    Stanko, Z. P.; Nishikawa, T.; Paulinski, S. R.

    2015-12-01

    The City of Santa Barbara, located in coastal southern California, is concerned that excessive groundwater pumping will lead to chloride (Cl) contamination of its groundwater system from seawater intrusion (SWI). In addition, the city wishes to estimate the effect of continued pumping on the groundwater basin under a variety of initial and climatic conditions. A SEAWAT-based groundwater-flow and solute-transport model of the Santa Barbara groundwater basin was optimized to produce optimal pumping schedules assuming 5 different scenarios. Borg, a multi-objective genetic algorithm, was coupled with the SEAWAT model to identify optimal management strategies. The optimization problems were formulated as multi-objective so that the tradeoffs between maximizing pumping, minimizing SWI, and minimizing drawdowns can be examined by the city. Decisions can then be made on a pumping schedule in light of current preferences and climatic conditions. Borg was used to produce Pareto optimal results for all 5 scenarios, which vary in their initial conditions (high water levels, low water levels, or current basin state), simulated climate (normal or drought conditions), and problem formulation (objective equations and decision-variable aggregation). Results show mostly well-defined Pareto surfaces with a few singularities. Furthermore, the results identify the precise pumping schedule per well that was suitable given the desired restriction on drawdown and Cl concentrations. A system of decision-making is then possible based on various observations of the basin's hydrologic states and climatic trends without having to run any further optimizations. In addition, an assessment of selected Pareto-optimal solutions was analyzed with sensitivity information using the simulation model alone. A wide range of possible groundwater pumping scenarios is available and depends heavily on the future climate scenarios and the Pareto-optimal solution selected while managing the pumping wells.

  6. REAL-TIME MEASUREMENTS OF THE CHEMICAL COMPOSITION OF SIZE-RESOLVED PARTICLES DURING A SANTA ANA WIND EPISODE, CALIFORNIA USA. (R826240)

    EPA Science Inventory

    Size-resolved particle composition, mass and number concentrations, aerosol scattering coefficients, and prevailing meteorological conditions were measured at the Ellen Browning Scripps Memorial Pier located in La Jolla, California on 15 December 1998. Aerosol particles were s...

  7. Physical, Nutrient, and Biological Measurements of Coastal Waters off Central California in June 2007

    DTIC Science & Technology

    2007-10-01

    Universidad Autonoma de Baja California Ensenada, Mexico Libe Washburn University of California Santa Barbara, CA Paul Choboter CalPoly...State University San Luis Obispo, CA Roger Hewitt NOAA La Jolla, CA Carmen G. Castro Consejo Superior de Investigaciones Científicas Spain

  8. Physical, Nutrient, and Biological Measurements of Coastal Waters off Central California in October 2008

    DTIC Science & Technology

    2009-05-01

    Reginaldo Durazo Universidad Autonoma de Baja California Ensenada, Mexico Libe Washburn University of California Santa Barbara, CA Paul Choboter...CalPoly State University San Luis Obispo, CA Roger Hewitt NOAA La Jolla, CA Carmen G. Castro Consejo Superior de Investigaciones

  9. Physical, Nutrient, and Biological Measurements of Coastal Waters off Central California in June 2008

    DTIC Science & Technology

    2008-12-01

    Universidad Autonoma de Baja California Ensenada, Mexico Libe Washburn University of California Santa Barbara, CA Paul Choboter CalPoly State...University San Luis Obispo, CA Roger Hewitt NOAA La Jolla, CA Carmen G. Castro Consejo Superior de Investigaciones Científicas Spain

  10. Physical, Nutrient, and Biological Measurements of Coastal Waters off Central California in July 2010

    DTIC Science & Technology

    2011-04-01

    although the inshore/offshore disparity was markedly less along Line 60. Both these results may reflect stronger ekman transport-driven offshore...Universidad Autonoma de Baja California Ensenada, Mexico Libe Washburn University of California Santa Barbara, CA Paul Choboter CalPoly State

  11. Development and characterization of 12 microsatellite markers for the Island Night Lizard (Xantusia riversiana), a threatened species endemic to the Channel Islands, California, USA

    USGS Publications Warehouse

    O'Donnell, Ryan P.; Drost, Charles A.; Mock, Karen E.

    2014-01-01

    The Island Night Lizard is a federally threatened species endemic to the Channel Islands of California. Twelve microsatellite loci were developed for use in this species and screened in 197 individuals from across San Nicolas Island, California. The number of alleles per locus ranged from 6 to 21. Observed heterozygosities ranged from 0.520 to 0.843. These microsatellite loci will be used to investigate population structure, effective population size, and gene flow across the island, to inform protection and management of this species.

  12. GEOCHEMICAL EVOLUTION OF GROUND WATER AND TRANSPORT OF MERCURY AT THE SULPHUR BANK MERCURY MINE SUPERFUND SITE IN NORTHERN CALIFORNIA, USA

    EPA Science Inventory

    The Sulphur Bank Mercury Mine, located on the shore of Clear Lake, Lake County, California, is a potential source for a modern-day mercury flux into the local aquatic ecosystem. Surface mining created the Herman Pit, a 9.3 ha open pit with a depth > 30 m, while overburden and pr...

  13. Recommendations to improve the cleanup process for California`s leaking underground fuel tanks (LUFTs)

    SciTech Connect

    Rice, D.W.; Dooher, B.P.; Cullen, S.J.; Everett, L.G.; Kastenberg, W.E.; Grose, R.D.; Marino, M.A.

    1996-12-01

    This document summarizes the findings, conclusions, and recommendations resulting from an 18 month review of the regulatory framework and cleanup process currently applied to California`s leaking underground fuel tanks (LUFT). This review was conducted by the Lawrence Livermore National Laboratory (LLNL) and the University of California at Berkeley, Davis, Los Angeles, and Santa Barbara at the request of the State Water Resources Control Board (SWRCB), Underground Storage Tank Program. The recommendations are made to improve and streamline the LUFT cleanup decision-making process.

  14. Introduction: the influence and legacy of Barbara Grier.

    PubMed

    DeMuth, Danielle M

    2014-01-01

    This special issue of the Journal of Lesbian Studies focuses on the life and legacy of the lesbian publisher, editor, and author Barbara Grier. Through Grier's "Lesbiana" column in Daughters of Bilitis's magazine The Ladder, three editions of The Lesbian in Literature (1967, 1975, 1985), to her role as publisher of the Naiad Press from 1973-2003, Grier introduced hundreds of new lesbian books to readers and kept several lesbian classics on the literary horizon. The articles in this issue focus on Grier's biography, history, and impact through archival analysis, interviews, and content analysis. This introduction contextualizes and outlines the articles in this special issue.

  15. Multiproxy record of the last interglacial (MIS 5e) off central and northern California, U.S.A., from Ocean Drilling Program sites 1018 and 1020

    USGS Publications Warehouse

    Poore, Richard Z.; Dowsett, H.J.; Barron, J.A.; Heusser, L.; Ravelo, A.C.; Mix, A.

    2000-01-01

    Environmental and climatic conditions during the last interglacial (about 125,000 years ago) along the Central and Northern California coastal region are interpreted from study of marine cores recovered by the Ocean Drilling Program at sites 1018 and 1020. Marine microfossil and pollen assemblages, oxygen isotopes in benthic foraminifers, physical properties, and calcium carbonate contents of cored sediments are proxies indicating strong links between the marine and terrestrial environments during marine isotope stage 5 (MIS 5). At the beginning of the last interglacial (MIS 5e), reduction in global ice volume, increase in surface temperature, and warming of air temperature along the Central and Northern California coast were synchronous within the resolution of our sampling record.

  16. Role of State Tsunami Geoscientists during Emergency Response Activities: Example from the State of California (USA) during September 29, 2009, Samoa Tsunami Event

    NASA Astrophysics Data System (ADS)

    Wilson, R. I.; Dengler, L. A.; Goltz, J. D.; Legg, M.; Miller, K. M.; Parrish, J. G.; Whitmore, P.

    2009-12-01

    California tsunami geoscientists work closely with federal, state and local government emergency managers to help prepare coastal communities for potential impacts from a tsunami before, during, and after an event. For teletsunamis, as scientific information (forecast model wave heights, first-wave arrival times, etc.) from NOAA’s West Coast and Alaska’s Tsunami Warning Center is made available, state-level emergency managers must help convey this information in a concise and comprehendible manner to local officials who ultimately determine the appropriate response activities for their jurisdictions. During the Samoa Tsunami Advisory for California on September 29, 2009, geoscientists from the California Geological Survey and Humboldt State University assisted the California Emergency Management Agency in this information transfer by providing technical assistance during teleconference meetings with NOAA and other state and local emergency managers prior to the arrival of the tsunami. State geoscientists gathered additional background information on anticipated tidal conditions and wave heights for areas not covered by NOAA’s forecast models. The participation of the state geoscientists in the emergency response process resulted in clarifying which regions were potentially at-risk, as well as those having a low risk from the tsunami. Future tsunami response activities for state geoscientists include: 1) working closely with NOAA to simplify their tsunami alert messaging and expand their forecast modeling coverage, 2) creation of “playbooks” containing information from existing tsunami scenarios for local emergency managers to reference during an event, and 3) development of a state-level information “clearinghouse” and pre-tsunami field response team to assist local officials as well as observe and report tsunami effects.

  17. East versus West: organic contaminant differences in brown pelican (Pelecanus occidentalis) eggs from South Carolina, USA and the Gulf of California, Mexico.

    PubMed

    Vander Pol, Stacy S; Anderson, Daniel W; Jodice, Patrick G R; Stuckey, Joyce E

    2012-11-01

    Brown pelicans (Pelecanus occidentalis) were listed as endangered in the United States in 1970, largely due to reproductive failure and mortality caused by organochlorine contaminants, such as DDT. The southeast population, P.o. carolinensis, was delisted in 1985, while the west coast population, P.o. californicus, was not delisted until 2009. As fish-eating coastal seabirds, brown pelicans may serve as a biomonitors. Organic contaminants were examined in brown pelican eggs collected from the Gulf of California in 2004 and South Carolina in 2005 using gas chromatography/mass spectrometry (GC/MS). Contaminants were compared using all individual data as well as statistically pooled samples to provide similar sample sizes with little difference in results. Principal components analysis separated the Gulf of California brown pelican eggs from the South Carolina eggs based on contaminant patterns. The South Carolina population had significantly (P<0.05) higher levels of polychlorinated biphenyls (PCBs), chlordanes, dieldrin and mirex, while the Gulf of California eggs had higher levels of dichlorodiphenyltrichloroethanes (DDTs) and hexachlorocyclohexanes (HCHs). With the exception of dieldrin and brominated diphenyl ether (BDE) 47, this pattern was observed for mussel and oyster tissues from these regions, indicating the need for further study into the differences between east and west coast brown pelican populations and ecosystem contamination patterns.

  18. East versus West: organic contaminant differences in brown pelican (Pelecanus occidentalis) eggs from South Carolina, USA and the Gulf of California, Mexico

    USGS Publications Warehouse

    Vander Pol, Stacy S.; Anderson, Daniel W.; Jodice, Patrick G.; Stuckey, Joyce E.

    2015-01-01

    Brown pelicans (Pelecanus occidentalis) were listed as endangered in the United States in 1970, largely due to reproductive failure and mortality caused by organochlorine contaminants, such as DDT. The southeast population, P.o. carolinensis, was delisted in 1985, while the west coast population, P.o. californicus, was not delisted until 2009. As fish-eating coastal seabirds, brown pelicans may serve as a biomonitors. Organic contaminants were examined in brown pelican eggs collected from the Gulf of California in 2004 and South Carolina in 2005 using gas chromatography/mass spectrometry (GC/MS). Contaminants were compared using all individual data as well as statistically pooled samples to provide similar sample sizes with little difference in results. Principal components analysis separated the Gulf of California brown pelican eggs from the South Carolina eggs based on contaminant patterns. The South Carolina population had significantly (P < 0.05) higher levels of polychlorinated biphenyls (PCBs), chlordanes, dieldrin and mirex, while the Gulf of California eggs had higher levels of dichlorodiphenyltrichloroethanes (DDTs) and hexachlorocyclohexanes (HCHs). With the exception of dieldrin and brominated diphenyl ether (BDE) 47, this pattern was observed for mussel and oyster tissues from these regions, indicating the need for further study into the differences between east and west coast brown pelican populations and ecosystem contamination patterns.

  19. An endobiont-bearing allogromiid from the Santa Barbara Basin: Implications for the early diversification of foraminifera

    NASA Astrophysics Data System (ADS)

    Bernhard, Joan M.; Habura, Andrea; Bowser, Samuel S.

    2006-09-01

    Our current understanding of paleoecology and paleoceanography is largely based on the superb Phanerozoic fossil record of foraminiferan protists. The early history of the group is unresolved, however, because basal foraminiferans (allogromiids) are unmineralized and thus fossilize poorly. Molecular-clock studies date foraminiferal origins to the Neoproterozoic, but the deep sea, one of Earth's most extensive habitats and presently hosting a significant fraction of basal foraminiferal diversity, was probably anoxic at that time and, until now, anaerobic allogromiids were unknown. Molecular, cell, and ecological analyses reveal the presence of a previously unknown allogromiid inhabiting anoxic, sulfidic deep-sea sediments (Santa Barbara Basin, California). The fact that the new foraminifer harbors prokaryotic endobionts implicates symbiogenesis as a driving force in early foraminiferal diversification.

  20. Identification of Geologic and Anthropogenic Sources of Phosphorus to Streams in California and Portions of Adjacent States, U.S.A., Using SPARROW Modeling

    NASA Astrophysics Data System (ADS)

    Domagalski, J. L.

    2013-12-01

    The SPARROW (Spatially Referenced Regressions On Watershed Attributes) model allows for the simulation of nutrient transport at un-gauged catchments on a regional scale. The model was used to understand natural and anthropogenic factors affecting phosphorus transport in developed, undeveloped, and mixed watersheds. The SPARROW model is a statistical tool that allows for mass balance calculation of constituent sources, transport, and aquatic decay based upon a calibration of a subset of stream networks, where concentrations and discharge have been measured. Calibration is accomplished using potential sources for a given year and may include fertilizer, geological background (based on bed-sediment samples and aggregated with geochemical map units), point source discharge, and land use categories. NHD Plus version 2 was used to model the hydrologic system. Land to water transport variables tested were precipitation, permeability, soil type, tile drains, and irrigation. For this study area, point sources, cultivated land, and geological background are significant phosphorus sources to streams. Precipitation and clay content of soil are significant land to water transport variables and various stream sizes show significance with respect to aquatic decay. Specific rock types result in different levels of phosphorus loading and watershed yield. Some important geological sources are volcanic rocks (andesite and basalt), granodiorite, glacial deposits, and Mesozoic to Cenozoic marine deposits. Marine sediments vary in their phosphorus content, but are responsible for some of the highest natural phosphorus yields, especially along the Central and Southern California coast. The Miocene Monterey Formation was found to be an especially important local source in southern California. In contrast, mixed metamorphic and igneous assemblages such as argillites, peridotite, and shales of the Trinity Mountains of northern California result in some of the lowest phosphorus yields. The

  1. On the importance of stratigraphic control for vertebrate fossil sites in Channel Islands National Park, California, USA: Examples from new Mammuthus finds on San Miguel Island

    USGS Publications Warehouse

    Pigati, Jeffery S.; Muhs, Daniel R.; McGeehin, John P.

    2016-01-01

    Quaternary vertebrate fossils, most notably mammoth remains, are relatively common on the northern Channel Islands of California. Well-preserved cranial, dental, and appendicular elements of Mammuthus exilis (pygmy mammoth) and Mammuthus columbi (Columbian mammoth) have been recovered from hundreds of localities on the islands during the past half-century or more. Despite this paleontological wealth, the geologic context of the fossils is described in the published literature only briefly or not at all, which has hampered the interpretation of associated 14C ages and reconstruction of past environmental conditions. We recently discovered a partial tusk, several large bones, and a tooth enamel plate (all likely mammoth) at two sites on the northwest flank of San Miguel Island, California. At both localities, we documented the stratigraphic context of the fossils, described the host sediments in detail, and collected charcoal and terrestrial gastropod shells for radiocarbon dating. The resulting 14C ages indicate that the mammoths were present on San Miguel Island between ∼20 and 17 ka as well as between ∼14 and 13 ka (thousands of calibrated 14C years before present), similar to other mammoth sites on San Miguel, Santa Cruz, and Santa Rosa Islands. In addition to documenting the geologic context and ages of the fossils, we present a series of protocols for documenting and reporting geologic and stratigraphic information at fossil sites on the California Channel Islands in general, and in Channel Islands National Park in particular, so that pertinent information is collected prior to excavation of vertebrate materials, thus maximizing their scientific value.

  2. 77 FR 39638 - Safety Zone; Barbara Harder Wedding Fireworks, Lake Erie, Lake View, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-05

    ... No. USCG-2012-0568] RIN 1625-AA00 Safety Zone; Barbara Harder Wedding Fireworks, Lake Erie, Lake View... temporary safety zone on Lake Erie, Lake View, NY. This safety zone is intended to restrict vessels from a portion of Lake Erie during the Barbara Harder Wedding Fireworks. This temporary safety zone is...

  3. 33 CFR 167.451 - In the Santa Barbara Channel: Between Point Vicente and Point Conception.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false In the Santa Barbara Channel: Between Point Vicente and Point Conception. 167.451 Section 167.451 Navigation and Navigable Waters COAST....451 In the Santa Barbara Channel: Between Point Vicente and Point Conception. (a) A separation zone...

  4. 33 CFR 167.450 - In the Santa Barbara Channel Traffic Separation Scheme: General.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false In the Santa Barbara Channel... Description of Traffic Separation Schemes and Precautionary Areas Pacific West Coast § 167.450 In the Santa Barbara Channel Traffic Separation Scheme: General. The Traffic Separation Scheme in the Santa...

  5. The Population Ecology of a Rare and Endangered Plant Species, ’Cirsium rhothophilum’ on Vandenberg AFB, California.

    DTIC Science & Technology

    1979-11-01

    297-30q. PIGOTY, C.D. 1968. Biological flora of the British isles. Cirsium acaulon (L.) Scop. J. Ecol. 56:597-612. POWELL, W.R. (ed.). 1974. Inventory... of the Santa Barbara Region, California. Santa Barbara Museum of Natural History, Santa Barbara, 331 pp. United States Department of the Air Force...habitat. U. S. Dept. of the Interior, Fish and Wildlife Service. Federdi Register, Vol. 40, No. 127, pp. 27824-27924. 5)3 SMITH, C.F. 1976. A flora

  6. Isolation of Leptospira from a phocid: acute renal failure and mortality from Leptospirosis in rehabilitated northern elephant seals (Mirounga angustirostris), California, USA.

    PubMed

    Delaney, Martha A; Colegrove, Kathleen M; Spraker, Terry R; Zuerner, Richard L; Galloway, Renee L; Gulland, Frances M D

    2014-07-01

    During rehabilitation, acute renal failure due to leptospirosis occurred in eight male northern elephant seals (Mirounga angustirostris) that stranded along the central California coast in 2011. Characteristic histologic lesions including renal tubular degeneration, necrosis, and mineralization, and mild lymphoplasmacytic interstitial nephritis were noted in the six animals examined. Immunohistochemistry, bacterial culture, and PCR were positive in 2/3, 2/3, and 3/4 seals, respectively, and 6/8 had high serum antibody titers to Leptospira interrogans serovar pomona. Pulsed-field gel electrophoresis confirmed one isolate as serovar pomona. Variable number tandem repeat (VNTR) analysis showed both elephant seal isolates were identical to each other but distinct from those isolated from California sea lions (Zalophus californianus). The time from stranding to onset of azotemia was 1 to 38 (median=24) days, suggesting some seals were infected at the rehabilitation facility. Based on temporal and spatial incidence of infection, transmission among elephant seals likely occurred during rehabilitation. Molecular (VNTR) analysis of the two isolates indicates there is a unique L. interrogans serovar pomona genotype in elephant seals, and sea lions were not the source of infection prior to or during rehabilitation. This study confirms the susceptibility of northern elephant seals to leptospirosis, indicates intraspecies transmission during rehabilitation, and reports the first isolation and preliminary characterization of leptospires from elephant seals.

  7. Mapping variations in weight percent silica measured from multispectral thermal infrared imagery - Examples from the Hiller Mountains, Nevada, USA and Tres Virgenes-La Reforma, Baja California Sur, Mexico

    USGS Publications Warehouse

    Hook, S.J.; Dmochowski, J.E.; Howard, K.A.; Rowan, L.C.; Karlstrom, K.E.; Stock, J.M.

    2005-01-01

    Remotely sensed multispectral thermal infrared (8-13 ??m) images are increasingly being used to map variations in surface silicate mineralogy. These studies utilize the shift to longer wavelengths in the main spectral feature in minerals in this wavelength region (reststrahlen band) as the mineralogy changes from felsic to mafic. An approach is described for determining the amount of this shift and then using the shift with a reference curve, derived from laboratory data, to remotely determine the weight percent SiO2 of the surface. The approach has broad applicability to many study areas and can also be fine-tuned to give greater accuracy in a particular study area if field samples are available. The approach was assessed using airborne multispectral thermal infrared images from the Hiller Mountains, Nevada, USA and the Tres Virgenes-La Reforma, Baja California Sur, Mexico. Results indicate the general approach slightly overestimates the weight percent SiO2 of low silica rocks (e.g. basalt) and underestimates the weight percent SiO2 of high silica rocks (e.g. granite). Fine tuning the general approach with measurements from field samples provided good results for both areas with errors in the recovered weight percent SiO2 of a few percent. The map units identified by these techniques and traditional mapping at the Hiller Mountains demonstrate the continuity of the crystalline rocks from the Hiller Mountains southward to the White Hills supporting the idea that these ranges represent an essentially continuous footwall block below a regional detachment. Results from the Baja California data verify the most recent volcanism to be basaltic-andesite. ?? 2005 Elsevier Inc. All rights reserved.

  8. Rotation period of 234 Barbara, a further slowly spinning asteroid

    NASA Astrophysics Data System (ADS)

    Schober, H. J.

    1981-03-01

    The S-type asteroid 234 Barbara was observed photoelectrically for variations at CTIO, Chile, during the opposition in September 1979. A rotation period of P=26h5±0h.1(≙ 1d.104 ± 0d.004) was derived, with a lightcurve amplitude of at least Δm ≧ 0m.24. The lightcurve seems to show double wave characteristic, though the primary maximum and one of the minima are not observed directly. Absolute magnitude is Vbar(1,0) =9m.34 with B-V = +0m.92 and U-B=+0m.48; a phase coefficient of β = 0.035 mag/deg was derived.

  9. Effect of Microclimates on Evapotranspiration Rates, Energy Balance, and Water Use Estimation in the Sacramento-San Joaquin Delta, California, USA

    NASA Astrophysics Data System (ADS)

    Anderson, F.; Bergamaschi, B. A.; Von Dessonneck, T.; Keating, K.; Verfaillie, J. G.; Hatala, J.; Knox, S.; Baldocchi, D. D.; Fujii, R.

    2012-12-01

    Research involving the atmospheric-surface exchange of greenhouse gases in California's Sacramento-San Joaquin Delta (Delta) has primarily focused on peat oxidation and resulting subsidence from over a century of agricultural land management practices. Currently there is a network of flux towers used to investigate management plans to mitigate subsidence and, in some cases, increase land elevation. Nevertheless, Delta land elevations have decreased by over 10m and water resources are largely allocated to maintain levee stability and prevent salt-water intrusion into the Delta, the source of fresh water to over to 22 million Southern Californians. These water allocations are potentially modeled using outdated evapotranspiration (ET) rates. The network of flux towers in the Delta has provided researchers the ability to calculate the atmospheric exchange of water vapor from a variety of land surfaces. From these results, ET rates are found to be reduced compared to the same land surface measurements outside the Delta region and are most likely due to the Delta's unique microclimate. In the summertime, this area is an oasis of cool, moist air (Delta Breeze) when compared to other areas in the Sacramento and San Joaquin Valleys, where daytime high temperatures are often 5 to 10°C higher. The air mass that influences the delta region is formed from a complex interaction between the sub-tropical Pacific High pressure system, upwelling along the California coast, upper atmospheric westerlies, and the unique break in the California Coastal range (i.e. the San Francisco Bay). In general, ET rates are lower than the surrounding geography, as the onset of the "Delta Breeze" occurs in the afternoons, increasing the sensible heat exchange and reducing the energy available for latent heat. Current ET rates were calculated using eddy covariance flux systems for a variety of land uses within the Delta: agricultural crops (corn, rice, alfalfa, and irrigated pasture), a newly

  10. Composition of modern sand and Cretaceous sandstone derived from the Sierra Nevada, California, USA, with implications for Cenozoic and Mesozoic uplift and dissection

    NASA Astrophysics Data System (ADS)

    Ingersoll, Raymond V.

    2012-12-01

    The California Sierra Nevada represents the roots of a primarily Cretaceous magmatic arc that is presently being dissected extensively in the south and to a lesser degree in the north, where it is covered by Cenozoic volcanic rocks. The Cenozoic magmatic arc built on top of the Cretaceous arc has been dissected concurrently with northward migration of the Mendocino triple junction, south of which the magmatic arc is inactive. A north-to-south transect from the modern Cascade arc along the Sierra Nevada, therefore, acts as a proxy for evolution from an active undissected magmatic arc to a transitional arc to a dissected arc to intensely uplifted basement. Discriminant analysis of Cascade and Sierra Nevada modern alluvial sand defines four compositional groups and clearly distinguishes volcaniclastic undissected-arc and plutoniclastic uplifted-basement end members. Two intermediate compositional groups are primarily volcaniplutoniclastic and metamorphiplutoniclastic. The former group represents Dickinson's (1985) "transitional arc;" the latter represents "dissected arc." Sand composition in the southern Sierra Nevada reflects significant uplift, resulting from a combination of latest Cretaceous-Paleogene uplift and late Cenozoic Basin and Range extension (footwall uplift of the western rift shoulder), possibly enhanced by mantle-lithosphere delamination. High concentrations of quartz and feldspar, and near absence of aphanitic lithic fragments are typical of the southern Sierra Nevada and are characteristic of Dickinson's "basement uplift." Cretaceous sandstone petrofacies of the Great Valley Group (GVG) of western California document dissection of the Cretaceous magmatic arc, as well as erosion of residual orogenic highlands (analogous to modern Taiwan) formed during latest Jurassic arc-continent collision (Nevadan orogeny). When Cretaceous petrofacies data are entered into the modern-sand discriminant analysis as unknowns, they are classified into the modern