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Sample records for valley salton sea

  1. 75 FR 59285 - Sonny Bono Salton Sea National Wildlife Refuge Complex (Sonny Bono Salton Sea National Wildlife...

    Science.gov (United States)

    2010-09-27

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Fish and Wildlife Service Sonny Bono Salton Sea National Wildlife Refuge Complex (Sonny Bono Salton Sea National Wildlife Refuge and Coachella Valley National Wildlife Refuge), Imperial and Riverside Counties...

  2. Chemistry and geothermometry of brine produced from the Salton Sea Scientific drill hole, Imperial Valley, California

    Science.gov (United States)

    Thompson, J.M.; Fournier, R.O.

    1988-01-01

    The December 29-30, 1985, flow test of the State 2-14 well, also known as the Salton Sea Scientific drill hole, produced fluid from a depth of 1865-1877 m at a reservoir temperature of 305????5??C. Samples were collected at five different flashing pressures. The brines are Na-Ca-K-Cl-type waters with very high metal and low SO4 and HCO3 contents. Compositions of the flashed brines were normalized relative to the 25??C densities of the solutions, and an ionic charge balance was achieved by adjusting the Na concentration. Calculated Na/K geothermometer temperatures, using equations suggested by different investigators, range from 326?? to 364??C. The Mg/K2 method gives a temperature of about 350??C, Mg/Li2 about 282??, and Na/Li 395??-418??C. -from Authors

  3. 2010 USGS Lidar: Salton Sea (CA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The USGS Salton Sea project encompasses a 5-kilometer buffer around the Salton Sea, California. Dewberry classified LiDAR for a project boundary that touches 623...

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

    Science.gov (United States)

    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 Over the past 100 years, floodwaters have been replaced by agricultural drainage water and municipal discharges so that today, most of the water reaching the Salton Sea is agricultural drainwater flowing down the New,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

  5. Quarterly Fishery Surveys - Salton Sea [ds428

    Data.gov (United States)

    California Department of Resources — In the spring of 2003, California Department of Fish and Game (CDFG) personnel began quarterly sampling of Salton Sea fish at fourteen stations around the sea, as...

  6. Salton Sea ecosystem monitoring and assessment plan

    Science.gov (United States)

    Case(compiler), H. L.; Boles, Jerry; Delgado, Arturo; Nguyen, Thang; Osugi, Doug; Barnum, Douglas A.; Decker, Drew; Steinberg, Steven; Steinberg, Sheila; Keene, Charles; White, Kristina; Lupo, Tom; Gen, Sheldon; Baerenklau, Ken A.

    2013-01-01

    The Salton Sea, California’s largest lake, provides essential habitat for several fish and wildlife species and is an important cultural and recreational resource. It has no outlet, and dissolved salts contained in the inflows concentrate in the Salton Sea through evaporation. The salinity of the Salton Sea, which is currently nearly one and a half times the salinity of ocean water, has been increasing as a result of evaporative processes and low freshwater inputs. Further reductions in inflows from water conservation, recycling, and transfers will lower the level of the Salton Sea and accelerate the rate of salinity increases, reduce the suitability of fish and wildlife habitat, and affect air quality by exposing lakebed playa that could generate dust. Legislation enacted in 2003 to implement the Quantification Settlement Agreement (QSA) stated the Legislature’s intent for the State of California to undertake the restoration of the Salton Sea ecosystem. As required by the legislation, the California Resources Agency (now California Natural Resources Agency) produced the Salton Sea Ecosystem Restoration Study and final Programmatic Environmental Impact Report (PEIR; California Resources Agency, 2007) with the stated purpose to “develop a preferred alternative by exploring alternative ways to restore important ecological functions of the Salton Sea that have existed for about 100 years.” A decision regarding a preferred alternative currently resides with the California State Legislature (Legislature), which has yet to take action. As part of efforts to identify an ecosystem restoration program for the Salton Sea, and in anticipation of direction from the Legislature, the California Department of Water Resources (DWR), California Department of Fish and Wildlife (CDFW), U.S. Bureau of Reclamation (Reclamation), and U.S. Geological Survey (USGS) established a team to develop a monitoring and assessment plan (MAP). This plan is the product of that effort. The

  7. Avian disease at the Salton Sea

    Science.gov (United States)

    Friend, M.

    2002-01-01

    A review of existing records and the scientific literature was conducted for occurrences of avian diseases affecting free-ranging avifauna within the Salton Sea ecosystem. The period for evaluation was 1907 through 1999. Records of the U.S. Department of Agriculture, Bureau of Biological Survey and the scientific literature were the data sources for the period of 1907a??1939. The narrative reports of the U.S. Fish and Wildlife Service's Sonny Bono National Wildlife Refuge Complex and the epizootic database of the U.S. Geological Survey's National Wildlife Health Center were the primary data sources for the remainder of the evaluation. The pattern of avian disease at the Salton Sea has changed greatly over time. Relative to past decades, there was a greater frequency of major outbreaks of avian disease at the Salton Sea during the 1990s than in previous decades, a greater variety of disease agents causing epizootics, and apparent chronic increases in the attrition of birds from disease. Avian mortality was high for about a decade beginning during the mid-1920s, diminished substantially by the 1940s and was at low to moderate levels until the 1990s when it reached the highest levels reported. Avian botulism (Clostridium botulinum type C) was the only major cause of avian disease until 1979 when the first major epizootic of avian cholera (Pasteurella multocidia) was documented. Waterfowl and shorebirds were the primary species affected by avian botulism. A broader spectrum of species have been killed by avian cholera but waterfowl have suffered the greatest losses. Avian cholera reappeared in 1983 and has joined avian botulism as a recurring cause of avian mortality. In 1989, avian salmonellosis (Salmonella typhimurium) was first diagnosed as a major cause of avian disease within the Salton Sea ecosystem and has since reappeared several times, primarily among cattle egrets (Bubulcus ibis). The largest loss from a single epizootic occurred in 1992, when an estimated

  8. Trace elements and pesticides in Salton Sea area, California

    Science.gov (United States)

    Schroeder, Roy A.; Setmire, James G.; Wolfe, John C.

    1988-01-01

    Concentrations of numerous potentially toxic trace elements and pesticides were determined in water, sediment, and biota from the Salton Sea area in southestern California. Comparison of results with data from other studies in this area and from other areas, and with various water-quality standards or criteria, indicate that selenium probably is the principal contaminant of concern in the Salton Sea basin and that it probably is related to agricultural practices. Selenium is mobilized in the subsurface drainwater produced by agricultural irrigation and transported in ditches and rivers, some of which pass through or near the Salton Sea National Wildlife Refuge before entering the Salton Sea. Some selenium apparently is incorporated into the food chain. In response to the finding of elevated selenium residues in fish from the area by State agencies, the Imperial County Health Department has issued a health advisory restricting or prohibiting human consumption of fish from the Salton Sea and drains.

  9. Quarterly Water Quality Surveys - Salton Sea [ds429

    Data.gov (United States)

    California Department of Resources — In the spring of 2003, California Department of Fish and Game (CDFG) personnel began quarterly sampling of Salton Sea fish at fourteen stations around the sea, as...

  10. Correlation of wireline log characteristics with hydrothermal alteration and other reservoir properties of the Salton Sea and Westmorland geothermal fields, Imperial Valley, California, USA

    Energy Technology Data Exchange (ETDEWEB)

    Muramoto, F.S.; Elders, W.A.

    1984-05-01

    A detailed study of wireline logs from 11 wells in the Salton Sea and Westmorland geothermal systems was undertaken in order to determine the effects of hydrothermal alteration on the response of electrical and gamma-gamma density well logs. For the Salton Sea geothermal field, definite correspondence between log responses and hydrothermal mineralogy is evident, which in turn is related to the physical properties of the rocks. Three hydrothermal and one unaltered zone can be identified from log data on shales. These are: (1) the unaltered montmorillonite zone (<100/sup 0/ to 190/sup 0/C); (2) the illite zone (100/sup 0/ to 190/sup 0/C to 230/sup 0/ to 250/sup 0/C); (3) the chlorite zone (230/sup 0/ to 250/sup 0/C to 290/sup 0/ to 300/sup 0/C); and (4) the feldspar zone (>290/sup 0/ to 300/sup 0/C). The characteristic responses on well logs by which these zones are identified result primarily from changes in clay mineralogy of the shales and increases in density with progressive hydrothermal metamorphism. In the Westmorland geothermal field, differentiating mineral zones from log responses was only partially successful. However, analyses of both well log and petrologic data for wells Landers 1 and Kalin Farms 1 suggest that the former is heating up and the latter is cooling.

  11. Groundwater Availability Within the Salton Sea Basin Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Tompson, A; Demir, Z; Moran, J; Mason, D; Wagoner, J; Kollet, S; Mansoor, K; McKereghan, P

    2008-01-11

    It is widely recognized that increasing demands for water in Southern California are being affected by actions to reduce and redirect the amount of water imported from the Colorado River. In the Imperial Valley region, for example, import reductions will not only affect agricultural users but also could produce significant collateral impacts on the level and quality of water in the Salton Sea, its regional ecology, or even the long term air quality in the greater basin. The notion of using groundwater in the Imperial Valley as an additional source for agricultural or domestic needs, energy production, or Salton Sea restoration efforts, so as to offset reductions in imported water, is not a new concept. Even though it has been discussed recently (e.g., LLNL, 2002), the idea goes back, in part, to several studies performed by the US Department of Interior and other agencies that have indicated that there may be substantial, usable amounts of groundwater in some portions of the Imperial Valley. It has been estimated, for example, that between 1.1 and 3 billion acre-feet (AF) of groundwater lie within the extended, deep basin underlying the valley and Salton Sea region, even though much of it may be unrecoverable or too poor in its quality (Imperial County, 1997). This is a significant volume with respect to the total annual precipitation volume received in California, whose average is close to 200 million (or 0.2 billion) AF per year (DWR, 1998), and especially with respect to the total annual precipitation received in the Salton Sea watershed itself, which we estimate (Appendix A) to be approximately 2.5 million acre feet (MAF) per year. Clearly, a thorough appraisal of the groundwater resources in the Imperial Valley and Salton Sea region--i.e., an assessment of their overall physical availability--will be needed to determine how they can be used and managed to suit new or redirected demands in the region. Development of an improved or updated groundwater assessment

  12. Salton Sea Project, Phase 1. [solar pond power plant

    Science.gov (United States)

    Peelgren, M. L.

    1982-01-01

    A feasibility study was made for a salt gradient solar pond power plant in or near the Salton Sea of California. The conclusions support continuance 5-MWe proof-of-concept experiment, and ultimate construction by an electric utility company of a 600-MWe plant. The Solar Pond concept would be an environmental benefit to the Salton Sea by reversing the increasing salinity trend. The greatest cost drivers are the lake dike construction and pond sealing. Problems to be resolved include method of brine production from Salton Sea water for the first unit (which requires evaporation pond area and time), the high turbidity and color content of the Salton Sea water (which requires pretreatment), and other questions related to pond permeability, bio-activity and soil/brine chemical reactions. All technical and environmental problems appear solvable and/or manageable if care is taken in mitigating impacts.

  13. 78 FR 44144 - Sonny Bono Salton Sea National Wildlife Refuge Complex (Sonny Bono Salton Sea National Wildlife...

    Science.gov (United States)

    2013-07-23

    ... Leader, at 760-348-5278, extension 227. Further information may also be found at http://go.usa.gov/jbhn... alternatives for managing the Sonny Bono Salton Sea NWR and three alternatives for managing the Coachella...

  14. Geology of the Desert Hot Springs-Upper Coachella Valley Area, California (with a selected bibliography of the Coachella Valley, Salton Sea, and vicinity)

    Energy Technology Data Exchange (ETDEWEB)

    Proctor, Richard J.

    1968-01-01

    The Desert Hot Springs area is in the upper Coachella Valley at the junction of three natural geomorphic provinces of California--the Transverse Ranges, the Peninsular Ranges, and the Colorado Desert. The mapped area is about 100 miles east of Los Angeles and lies principally in north central Riverside County. The oldest rocks in the area are Precambrian(?) amphibolitic and migmatized paragneisses of the San Gorgonio igneous-metamorphic (Chuckwalla) complex. They are intruded by Cretaceous diorite porphyry, Cactus Granite, quartz monzonite, intrusive breccia, and basic plutonic rocks. Of probable late Paleozoic age are the metamorphic rocks of the San Jacinto Mountains which form spurs projecting into San Gorgonio Pass and Coachella Valley.

  15. State of the Salton Sea—A science and monitoring meeting of scientists for the Salton Sea

    Science.gov (United States)

    Barnum, Douglas A.; Bradley, Timothy; Cohen, Michael; Wilcox, Bruce; Yanega, Gregor

    2017-01-19

    IntroductionThe Salton Sea (Sea) is an ecosystem facing large systemic changes in the near future. Managers and stakeholders are seeking solutions to the decline of the Sea and have turned to the scientific community for answers. In response, scientists gathered in Irvine, California, to review existing science and propose scientific studies and monitoring needs required for understanding how to retain the Sea as a functional ecosystem. This document summarizes the proceedings of this gathering of approximately 50 scientists at a September 8–10, 2014, workshop on the State of the Salton Sea.

  16. Possible importance of algal toxins in the Salton Sea, California

    Science.gov (United States)

    Reifel, K.M.; McCoy, M.P.; Rocke, T.E.; Tiffany, M.A.; Hurlbert, S.H.; Faulkner, D.J.

    2002-01-01

    In response to wildlife mortality including unexplained eared grebe (Podiceps nigricollis) die-off events in 1992 and 1994 and other mortality events including large fish kills, a survey was conducted for the presence of algal toxins in the Salton Sea. Goals of this survey were to determine if and when algal toxins are present in the Salton Sea and to describe the phytoplankton composition during those times. A total of 29 samples was collected for toxicity analysis from both nearshore and midlake sites visited biweekly from January to December 1999. Dinoflagellates and diatoms dominated most samples, but some were dominated by a prymnesiophyte (Pleurochrysis pseudoroscoffensis) or a raphidophyte (Chattonella marina). Several types of blooms were observed and sampled. The dinoflagellate Gyrodinium uncatenum formed an extensive, dense (up to 310 000 cells ml-1) and long-lasting bloom during the winter in 1999. A coccolithophorid, Pleurochrysis pseudoroscoffensis, occurred at high densities in surface films and nearshore areas during the spring and summer of 1999. These surface films also contained high densities of one or two other species (an unidentified scrippsielloid, Heterocapsa niei, Chattonella marina). Localized blooms were also observed in the Salton Sea. An unknown small dinoflagellate reached high densities (110 000 cells ml-1) inside Varner Harbor, and an unidentified species of Gymnodinium formed a dense (270 000 cells ml-1) band along part of the southern shoreline during the summer. Three species known to produce toxins in other systems were found. Protoceratium reticulatum (=Gonyaulax grindleyi) and Chattonella marina were found in several samples taken during summer months, and Prorocentrum minimum was found in low densities in several samples. Extracts of most samples, including those containing known toxic species, showed a low level (brine shrimp lethality assay and were not considered toxic. All sample extracts tested in the mouse bioassay

  17. Characterizing Novel Archaeal Lineages in Salton Sea Sediments

    Science.gov (United States)

    Tarn, J.; Valentine, D. L.

    2016-12-01

    Biological communities in extreme environments are often dominated by microorganisms of the domain Archaea. Abundant microbial assemblages of this group are found in the hottest, saltiest, and most thermodynamically-limited ecosystems on earth. These taxing surroundings are thought to impose a state of chronic energy stress on resident organisms due to high costs of cellular maintenance relative to resource availability. Even in more temperate settings, Archaea are regularly associated with low-nutrient lifestyles, reflecting their adaptation to extreme, biologically-limiting conditions, which may be an ancestral, domain-wide trait. In this study, we seek to characterize the Archaeal community of the Salton Sea, where members of this domain are novel and highly abundant. Previous work by Swan et al. in 2010 showed that gradients in salinity, sulfate, carbon and nitrogen across sediment horizons of the Salton Sea are linked to changes in Archaeal dominance and community structure. In light of recent taxonomic revisions of the domain, I reclassified the 107 published small subunit rRNA Archaeal sequences from the 2010 study using updated reference databases. The majority of these Euryarchaeal sequences were reassigned to the so-called DPANN superphylum, with Pacearchaeota-related sequences being very abundant in shallow, organic-rich sediments. In deeper, energy-limited strata, several groups of Bathyarchaeota and one divergent DPANN clade were dominant. Ongoing metagenomic work on these sediment communities is being used to assemble genomes of these novel Archaeal groups. These results will help define genomic adaptations of Salton Sea Archaea to varying levels of energy stress as well as inform future cultivation efforts.

  18. Salton Sea Scientific Drilling Project: A summary of drilling and engineering activities and scientific results

    Energy Technology Data Exchange (ETDEWEB)

    Ross, H.P.; Forsgren, C.K. (eds.)

    1992-04-01

    The Salton Sea Scientific g Project (SSSDP) completed the first major well in the United States Continental Scientific Drilling Program. The well (State 2-14) was drilled to 10,W ft (3,220 m) in the Salton Sea Geothermal Field in California's Imperial Valley, to permit scientific study of a deep, high-temperature portion of an active geothermal system. The program was designed to investigate, through drilling and testing, the subsurface thermal, chemical, and mineralogical environments of this geothermal area. Extensive samples and data, including cores, cuttings, geothermal fluids and gases, and geophysical logs, were collected for future scientific analysis, interpretation, and publication. Short duration flow tests were conducted on reservoirs at a depth of approximately 6,120 ft (1,865 m) and at 10,136 ft (3,089 m). This report summarizes all major activities of the SSSDP, from project inception in the fall of 1984 through brine-pond cleanup and site restoration, ending in February 1989. This report presents a balanced summary of drilling, coring, logging, and flow-test operations, and a brief summary of technical and scientific results. Frequent reference is made to original records, data, and publication of results. The report also reviews the proposed versus the final well design, and operational summaries, such as the bit record, the casing and cementing program, and the coring program. Summaries are and the results of three flow tests. Several teamed during the project.

  19. Environmental Contaminants in Piscivorous Birds at the Salton Sea, 1992-93

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This study indicates that there are reasons to be concerned about contaminant exposure in piscivorous birds at the Salton Sea. Of greatest concern is p,p'DDE....

  20. Snag Fields and Roosting and Nesting Sites - Salton Sea [ds393

    Data.gov (United States)

    California Department of Resources — This data set shows all the on-water or very nearshore avian resources used for nesting and roosting by specific bird species of interest around the Salton Sea....

  1. Technical Proposal Salton Sea Geothermal Power Pilot Plant Program

    Energy Technology Data Exchange (ETDEWEB)

    None

    1975-03-28

    The proposed Salton Sea Geothermal Power Pilot Plant Program comprises two phases. The objective of Phase 1 is to develop the technology for power generation from high-temperature, high-salinity geothermal brines existing in the Salton Sea known geothermal resources area. Phase 1 work will result in the following: (a) Completion of a preliminary design and cost estimate for a pilot geothermal brine utilization facility. (b) Design and construction of an Area Resource Test Facility (ARTF) in which developmental geothermal utilization concepts can be tested and evaluated. Program efforts will be divided into four sub-programs; Power Generation, Mineral Extraction, Reservoir Production, and the Area Resources Test Facility. The Power Generation Subprogram will include testing of scale and corrosion control methods, and critical power cycle components; power cycle selection based on an optimization of technical, environmental and economic analyses of candidate cycles; preliminary design of a pilot geothermal-electric generating station to be constructed in Phase 2 of this program. The Mineral Extraction Subprogram will involve the following: selection of an optimum mineral recovery process; recommendation of a brine clean-up process for well injection enhancement; engineering, construction and operation of mineral recovery and brine clean-up facilities; analysis of facility operating results from environmental, economical and technical point-of-view; preliminary design of mineral recovery and brine clean-up facilities of sufficient size to match the planned pilot power plant. The Reservoir Production Subprogram will include monitoring the operation and maintenance of brine production, handling and injection systems which were built with private funding in phase 0, and monitoring of the brine characteristics and potential subsidence effects during well production and injection. Based on the above, recommendations and specifications will be prepared for production and

  2. The Potential for Renewable Energy Development to Benefit Restoration of the Salton Sea. Analysis of Technical and Market Potential

    Energy Technology Data Exchange (ETDEWEB)

    Gagne, Douglas [National Renewable Energy Lab. (NREL), Golden, CO (United States); Haase, Scott [National Renewable Energy Lab. (NREL), Golden, CO (United States); Oakleaf, Brett [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hurlbut, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Akar, Sertac [National Renewable Energy Lab. (NREL), Golden, CO (United States); Wall, Anna [National Renewable Energy Lab. (NREL), Golden, CO (United States); Turchi, Craig [National Renewable Energy Lab. (NREL), Golden, CO (United States); Pienkos, Philip [National Renewable Energy Lab. (NREL), Golden, CO (United States); Melius, Jennifer [National Renewable Energy Lab. (NREL), Golden, CO (United States); Melaina, Marc [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-11-01

    This report summarizes the potential for renewable energy development in the Salton Sea region, as well as the potential for revenues from this development to contribute financially to Salton Sea restoration costs. It considers solar, geothermal, biofuels or nutraceutical production from algae pond cultivation, desalination using renewable energy, and mineral recovery from geothermal fluids.


  3. Double Difference Earthquake Locations at the Salton Sea Geothermal Reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Boyle, K L; Hutchings, L J; Bonner, B P; Foxall, W; Kasameyer, P W

    2007-08-08

    The purpose of this paper is to report on processing of raw waveform data from 4547 events recorded at 12 stations between 2001 and 2005 by the Salton Sea Geothermal Field (SSGF) seismic network. We identified a central region of the network where vertically elongated distributions of hypocenters have previously been located from regional network analysis. We process the data from the local network by first autopicking first P and S arrivals; second, improving these with hand picks when necessary; then, using cross-correlation to provide very precise P and S relative arrival times. We used the HypoDD earthquake location algorithm to locate the events. We found that the originally elongated distributions of hypocenters became more tightly clustered and extend down the extent of the study volume at 10 Km. However, we found the shapes to depend on choices of location parameters. We speculate that these narrow elongated zones of seismicity may be due to stress release caused by fluid flow.

  4. Sources of subsidence at the Salton Sea Geothermal Field

    Science.gov (United States)

    Barbour, Andrew J.; Evans, Eileen; Hickman, Stephen H.; Eneva, Mariana

    2016-01-01

    At the Salton Sea Geothermal Field (SSGF) in Southern California, surface deformation associated with geologic processes including sediment compaction, tectonic strain, and fault slip may be augmented by energy production activities. Separating the relative contributions from natural and anthropogenic sources is especially important at the SSGF, which sits at the apex of a complex tectonic transition zone connecting the southern San Andreas Fault with the Imperial Fault; but this has been a challenging task so far. Here we analyze vertical surface velocities obtained from the persistent scatterer InSAR method and find that two of the largest subsidence anomalies can be represented by a set of volumetric strain nuclei at depths comparable to geothermal well completion zones. In contrast, the rates needed to achieve an adequate fit to the magnitudes of subsidence are almost an order of magnitude greater than rates reported for annual changes in aggregate net-production volume, suggesting that the physical mechanism responsible for subsidence at the SSGF is a complicated interplay between natural and anthropogenic sources.

  5. Outdoor recreational use of the Salton Sea with reference to potential impacts of geothermal development

    Energy Technology Data Exchange (ETDEWEB)

    Twiss, R.; Sidener, J.; Bingham, G.; Burke, J.E.

    1978-04-01

    The objectives of this study were to describe the types, levels, and locations of outdoor recreation uses in the Salton Sea area, the number and principal activities of visitors, and to estimate the consequences upon outdoor recreation of geothermal development and other activities that might affect the Salton Sea. It is concluded that since the Salton Sea is considered legally to be a sump for agricultural, municipal, and presumably geothermal waste waters, recreational use of the Sea for fishing and boating (from present marinas) will undoubtedly continue to decline, unless there is a major policy change. Use of the shoreline for camping, the surrounding roads and lands for scenic viewing, ORV events, and retirement or recreation communities will not decline, and will probably increase, assuming control of hydrogen sulfide odors. Two ways in which the fishing and present boating facilities could be returned to a wholly usable steady state are discussed. One is by construction of a diked evaporation pond system at the south end of the Sea. This would allow a means of control over both water level and salinity. Another means, less costly but more difficult to effectively control, would be to budget geothermal plant use of, and disposal of wastes in, Salton Sea water. (JGB)

  6. Thermal and petrologic constraints on lower crustal melt accumulation under the Salton Sea Geothermal Field

    Science.gov (United States)

    Karakas, Ozge; Dufek, Josef; Mangan, Margaret T.; Wright, Heather M.; Bachmann, Olivier

    2017-06-01

    In the Salton Sea region of southern California (USA), concurrent magmatism, extension, subsidence, and sedimentation over the past 0.5 to 1.0 Ma have led to the creation of the Salton Sea Geothermal Field (SSGF)-the second largest and hottest geothermal system in the continental United States-and the small-volume rhyolite eruptions that created the Salton Buttes. In this study, we determine the flux of mantle-derived basaltic magma that would be required to produce the elevated average heat flow and sustain the magmatic roots of rhyolite volcanism observed at the surface of the Salton Sea region. We use a 2D thermal model to show that a lower-crustal, partially molten mush containing rate) given extension rates at or below the current value of ∼0.01 m/yr (Brothers et al., 2009). These regions of partial melt are a natural consequence of a thermal regime that scales with average surface heat flow in the Salton Trough, and are consistent with seismic observations. Our results indicate limited melting and assimilation of pre-existing rocks in the lower crust. Instead, we find that basalt fractionation in the lower crust produces derivative melts of andesitic to dacitic composition. Such melts are then expected to ascend and accumulate in the upper crust, where they further evolve to give rise to small-volume rhyolite eruptions (Salton Buttes) and fuel local spikes in surface heat flux as currently seen in the SSGF. Such upper crustal magma evolution, with limited assimilation of hydrothermally altered material, is required to explain the slight decrease in δ18 O values of zircons (and melts) that have been measured in these rhyolites.

  7. Analyses of operational times and technical aspects of the Salton Sea scientific drilling project: (Final report)

    Energy Technology Data Exchange (ETDEWEB)

    1986-12-01

    The Deep Salton Sea Scientific Drilling Program (DSSSDP) was conducted in Imperial County of California at the Southeastern edge of the Salton Sea. Emphasis was on the acquisition of scientific data for the evaluation of the geological environment encountered during the drilling of the well. The scientific data acquisition activities consisted of coring, running of numerous downhole logs and tools in support of defining the geologic environment and conducting two full scale flow tests primarily to obtain pristine fluid samples. In addition, drill cuttings, gases and drilling fluid chemistry measurements were obtained from the drilling fluid returns concurrent with drilling and coring operations. The well was drilled to 10,564 feet. This report describes the field portions of the project and presents an analysis of the time spent on the various activities associated with the normal drilling operations, scientific data gathering operations and the three major downhole problem activities - lost circulation, directional control and fishing.

  8. Pleurochrysis pseudoroscoffensis (Prymnesiophyceae) blooms on the surface of the Salton Sea, California

    Science.gov (United States)

    Reifel, K.M.; McCoy, M.P.; Tiffany, M.A.; Rocke, T.E.; Trees, C.C.; Barlow, S.B.; Faulkner, D.J.; Hurlbert, S.H.

    2001-01-01

    Dense populations of the coccolithophore Pleurochrysis pseudoroscoffensis were found in surface films at several locations around the Salton Sea in February-August, 1999. An unidentified coccolithophorid was also found in low densities in earlier studies of the lake (1955-1956). To our knowledge, this is the first record of this widespread marine species in any lake. Samples taken from surface films typically contained high densities of one or two other phytoplankton species as well as high densities of the coccolithophore. Presence or absence of specific algal pigments was used to validate direct cell counts. In a preliminary screen using a brine shrimp lethality assay, samples showed moderate activity. Extracts were then submitted to a mouse bioassay, and no toxic activity was observed. These results indicate that blooms of P. pseudoroscoffensis are probably not toxic to vertebrates and do not contribute to the various mortality events of birds and fish that occur in the Salton Sea.

  9. Diversity of terrestrial avifauna in response to distance from the shoreline of the Salton Sea

    Science.gov (United States)

    Mendelsohn, M.B.; Boarman, W.I.; Fisher, R.N.; Hathaway, S.A.

    2007-01-01

    Large aquatic bodies influence surrounding terrestrial ecosystems by providing water and nutrients. In arid landscapes, the increased primary productivity that results may greatly enhance vertebrate biodiversity. The Salton Sea, a large saline lake in the Colorado Desert of southern California, provides nutrients in the form of hundreds of thousands of dead fish carcasses, brine flies, and chemical compounds through windborne salt sea spray. We performed point counts for landbirds and shorebirds monthly or every other month between March 2001 and February 2002 across a sampling grid of 35 points along the west edge of Salton Sea. We found that avian diversity (numbers of species and numbers per species) was dependent on proximity to the Sea. Diversity was at a maximum nearest the shore, and was significantly lower away from the Sea's edge, at all surveyed distances up to 1 km from the shore. Cover by the dominant shrubs on the study site also corresponded to proximity to the water's edge. Whereas one may hypothesize that the avian diversity patterns are caused by these differences in vegetation structure, our data did not support this. Future studies should further investigate this potential correlation between vegetation and bird patterns. Until more is understood about the relationship between elevated avian diversity and the physical environment of the land-shore interface, our results suggest that the Sea's surface be stabilized near its present level. Future management schemes at the Salton Sea that include reductions of water sources should be carefully analyzed, so as to not jeopardize the terrestrial avifauna at this unique ecosystem. ?? 2006 Elsevier Ltd. All rights reserved.

  10. A linked hydrodynamic and water quality model for the Salton Sea

    Science.gov (United States)

    Chung, E.G.; Schladow, S.G.; Perez-Losada, J.; Robertson, Dale M.

    2008-01-01

    A linked hydrodynamic and water quality model was developed and applied to the Salton Sea. The hydrodynamic component is based on the one-dimensional numerical model, DLM. The water quality model is based on a new conceptual model for nutrient cycling in the Sea, and simulates temperature, total suspended sediment concentration, nutrient concentrations, including PO4-3, NO3-1 and NH4+1, DO concentration and chlorophyll a concentration as functions of depth and time. Existing water temperature data from 1997 were used to verify that the model could accurately represent the onset and breakup of thermal stratification. 1999 is the only year with a near-complete dataset for water quality variables for the Salton Sea. The linked hydrodynamic and water quality model was run for 1999, and by adjustment of rate coefficients and other water quality parameters, a good match with the data was obtained. In this article, the model is fully described and the model results for reductions in external phosphorus load on chlorophyll a distribution are presented. ?? 2008 Springer Science+Business Media B.V.

  11. A brine interface in the Salton Sea Geothermal System, California: Fluid geochemical and isotopic characteristics

    Science.gov (United States)

    Williams, Alan E.; McKibben, Michael A.

    1989-08-01

    Data from 71 geothermal production intervals in 48 wells from the Salton Sea Geothermal System (SSGS) indicate that fluids in that system cluster into two distinct populations in terms of their salinity and their stable isotopic compositions. The distinctive, hot, hypersaline brine (typically >20 wt% total dissolved solids) for which the SSGS is known is overlain by a cooler (barrier to convective heat and mass transfer in the SSGS, isolating the hypersaline reservoir from overlying dilute fluids. A lithologic "cap" implied by previous SSGS models is unnecessary in such a stratified system since heat and mass transfer across the interface must occur by slow conductive, diffusional and interface mixing processes regardless of local permeability.

  12. Occurrence of West Nile virus infection in raptors at the Salton Sea, California

    Science.gov (United States)

    Dusek, Robert J.; Iko, William M.; Hofmeister, Erik K.

    2010-01-01

    We investigated the prevalence of West Nile virus (WNV)-neutralizing antibodies and infectious virus, and the occurrence of overwinter transmission in two raptor species during January and March 2006 at the Salton Sea, Imperial County, California. We captured 208 American Kestrels (Falco sparverius) (January, n=100; March, n=108) and 116 Burrowing Owls (Athene cunicularia) (January, n=52; March, n=64). Laboratory analysis revealed that 83% of American Kestrels and 31% of Burrowing Owls were positive for WNV-neutralizing antibodies. Additionally, two seroconversions were detected in Burrowing Owls between January and March. Infectious WNV, consistent with acute infection, was not detected in any bird.

  13. Selenium in aquatic biota inhabiting agricultural drains in the Salton Sea Basin, California

    Science.gov (United States)

    Saiki, Michael K.; Martin, Barbara A.; May, Thomas W.

    2012-01-01

    Resource managers are concerned that water conservation practices in irrigated farmlands along the southern border of the Salton Sea, Imperial County, California, could increase selenium concentrations in agricultural drainwater and harm the desert pupfish (Cyprinodon macularius), a federally protected endangered species. As part of a broader attempt to address this concern, we conducted a 3-year investigation to collect baseline information on selenium concentrations in seven agricultural drains inhabited by pupfish. We collected water, sediment, selected aquatic food-chain taxa (particulate organic detritus, filamentous algae, net plankton, and midge [Chironomidae] larvae), and two poeciliid fishes (western mosquitofish Gambusia affinis and sailfin molly Poecilia latipinna) for selenium determinations. The two fish species served as ecological surrogates for pupfish, which we were not permitted to sacrifice. Dissolved selenium ranged from 0.70 to 32.8 μg/L, with selenate as the major constituent. Total selenium concentrations in other environmental matrices varied widely among drains, with one drain (Trifolium 18) exhibiting especially high concentrations in detritus, 5.98–58.0 μg Se/g; midge larvae, 12.7–50.6 μg Se/g; mosquitofish, 13.2–20.2 μg Se/g; and mollies, 12.8–30.4 μg Se/g (all tissue concentrations are based on dry weights). Although toxic thresholds for selenium in fishes from the Salton Sea are still poorly understood, available evidence suggests that ambient concentrations of this element may not be sufficiently elevated to adversely affect reproductive success and survival in selenium-tolerant poeciliids and pupfish.

  14. Character and Implications of a Newly Identified Creeping Strand of the San Andreas fault NE of Salton Sea, Southern California

    Science.gov (United States)

    Janecke, S. U.; Markowski, D.

    2015-12-01

    The overdue earthquake on the Coachella section, San Andreas fault (SAF), the model ShakeOut earthquake, and the conflict between cross-fault models involving the Extra fault array and mapped shortening in the Durmid Hill area motivate new analyses at the southern SAF tip. Geologic mapping, LiDAR, seismic reflection, magnetic and gravity datasets, and aerial photography confirm the existence of the East Shoreline strand (ESS) of the SAF southwest of the main trace of the SAF. We mapped the 15 km long ESS, in a band northeast side of the Salton Sea. Other data suggest that the ESS continues N to the latitude of the Mecca Hills, and is >35 km long. The ESS cuts and folds upper Holocene beds and appears to creep, based on discovery of large NW-striking cracks in modern beach deposits. The two traces of the SAF are parallel and ~0.5 to ~2.5 km apart. Groups of east, SE, and ENE-striking strike-slip cross-faults connect the master dextral faults of the SAF. There are few sinistral-normal faults that could be part of the Extra fault array. The 1-km wide ESS contains short, discontinuous traces of NW-striking dextral-oblique faults. These en-echelon faults bound steeply dipping Pleistocene beds, cut out section, parallel tight NW-trending folds, and produced growth folds. Beds commonly dip toward the ESS on both sides, in accord with persistent NE-SW shortening across the ESS. The dispersed fault-fold structural style of the ESS is due to decollements in faulted mud-rich Pliocene to Holocene sediment and ramps and flats along the strike-slip faults. A sheared ladder-like geometric model of the two master dextral strands of the SAF and their intervening cross-faults, best explains the field relationships and geophysical datasets. Contraction across >40 km2 of the southernmost SAF zone in the Durmid Hills suggest that interaction of active structures in the SAF zone may inhibit the nucleation of large earthquakes in this region. The ESS may cross the northern Coachella

  15. Use of a nesting platform by Gull-billed Terns and Black Skimmers at the Salton Sea, California

    Science.gov (United States)

    Molina, Kathy C.; Ricca, Mark A.; Miles, A. Keith; Schoneman, Christian

    2009-01-01

    In 2006, we constructed an elevated nesting platform at the Salton Sea, California, and monitored its use by Gull-billed Terns and Black Skimmers over three subsequent breeding seasons. Black Skimmers were the first to colonize the platform with a total of five nests in 2006. In 2007 Gull-billed Terns colonized the platform with a total of 28 nests and the number of Black Skimmer nests increased to 20. Neither species nested on the platform in 2008. Low success for both species was probably influenced by at least two factors. First, when both species nested on the platform, nest densities were higher than is typical of their colonies on larger, earthen islands, and colony success may have been reduced by overcrowding. Second, lack of access to water may have reduced chicks' ability to thermoregulate effectively in the hot environment of the Salton Sea. Refinements to the size, design, and location of artificial nesting habitats are necessary to enhance productivity of colonial groundnesting birds at the Salton Sea successfully.

  16. Occurrence, distribution and transport of pesticides into the Salton Sea Basin, California, 2001-2002

    Science.gov (United States)

    LeBlanc, L.A.; Kuivila, K.M.

    2008-01-01

    The Salton Sea is a hypersaline lake located in southeastern California. Concerns over the ecological impacts of sediment quality and potential human exposure to dust emissions from exposed lakebed sediments resulting from anticipated shrinking of shoreline led to a study of pesticide distribution and transport within the Salton Sea Basin, California, in 2001-2002. Three sampling stations-upriver, river mouth, and offshore-were established along each of the three major rivers that discharge into the Salton Sea. Large-volume water samples were collected for analysis of pesticides in water and suspended sediments at the nine sampling stations. Samples of the bottom sediment were also collected at each site for pesticide analysis. Sampling occurred in October 2001, March-April 2002, and October 2002, coinciding with the regional fall and spring peaks in pesticide use in the heavily agricultural watershed. Fourteen current-use pesticides were detected in water and the majority of dissolved concentrations ranged from the limits of detection to 151 ng/l. Diazinon, EPTC and malathion were detected at much higher concentrations (940-3,830 ng/l) at the New and Alamo River upriver and near-shore stations. Concentrations of carbaryl, dacthal, diazinon, and EPTC were higher in the two fall sampling periods, whereas concentrations of atrazine, carbofuran, and trifluralin were higher during the spring, which matched seasonal use patterns of these pesticides. Current-use pesticides were also detected on suspended and bed sediments in concentrations ranging from detection limits to 106 ng/g. Chlorpyrifos, dacthal, EPTC, trifluralin, and DDE were the most frequently detected pesticides on sediments from all three rivers. The number of detections and concentrations of suspended sediment-associated pesticides were often similar for the river upriver and near-shore sites, consistent with downstream transport of pesticides via suspended sediment. While detectable suspended sediment

  17. 3-D Velocity Model of the Coachella Valley, Southern California Based on Explosive Shots from the Salton Seismic Imaging Project

    Science.gov (United States)

    Persaud, P.; Stock, J. M.; Fuis, G. S.; Hole, J. A.; Goldman, M.; Scheirer, D. S.

    2014-12-01

    We have analyzed explosive shot data from the 2011 Salton Seismic Imaging Project (SSIP) across a 2-D seismic array and 5 profiles in the Coachella Valley to produce a 3-D P-wave velocity model that will be used in calculations of strong ground shaking. Accurate maps of seismicity and active faults rely both on detailed geological field mapping and a suitable velocity model to accurately locate earthquakes. Adjoint tomography of an older version of the SCEC 3-D velocity model shows that crustal heterogeneities strongly influence seismic wave propagation from moderate earthquakes (Tape et al., 2010). These authors improve the crustal model and subsequently simulate the details of ground motion at periods of 2 s and longer for hundreds of ray paths. Even with improvements such as the above, the current SCEC velocity model for the Salton Trough does not provide a match of the timing or waveforms of the horizontal S-wave motions, which Wei et al. (2013) interpret as caused by inaccuracies in the shallow velocity structure. They effectively demonstrate that the inclusion of shallow basin structure improves the fit in both travel times and waveforms. Our velocity model benefits from the inclusion of known location and times of a subset of 126 shots detonated over a 3-week period during the SSIP. This results in an improved velocity model particularly in the shallow crust. In addition, one of the main challenges in developing 3-D velocity models is an uneven stations-source distribution. To better overcome this challenge, we also include the first arrival times of the SSIP shots at the more widely spaced Southern California Seismic Network (SCSN) in our inversion, since the layout of the SSIP is complementary to the SCSN. References: Tape, C., et al., 2010, Seismic tomography of the Southern California crust based on spectral-element and adjoint methods: Geophysical Journal International, v. 180, no. 1, p. 433-462. Wei, S., et al., 2013, Complementary slip distributions

  18. Irregular focal mechanisms observed at Salton Sea Geothermal Field: Possible influences of anthropogenic stress perturbations

    Science.gov (United States)

    Crandall-Bear, Aren; Barbour, Andrew J.; Schoenball, Martin; Schoenball, Martin

    2018-01-01

    At the Salton Sea Geothermal Field (SSGF), strain accumulation is released through seismic slip and aseismic deformation. Earthquake activity at the SSGF often occurs in swarm-like clusters, some with clear migration patterns. We have identified an earthquake sequence composed entirely of focal mechanisms representing an ambiguous style of faulting, where strikes are similar but deformation occurs due to steeply-dipping normal faults with varied stress states. In order to more accurately determine the style of faulting for these events, we revisit the original waveforms and refine estimates of P and S wave arrival times and displacement amplitudes. We calculate the acceptable focal plane solutions using P-wave polarities and S/P amplitude ratios, and determine the preferred fault plane. Without constraints on local variations in stress, found by inverting the full earthquake catalog, it is difficult to explain the occurrence of such events using standard fault-mechanics and friction. Comparing these variations with the expected poroelastic effects from local production and injection of geothermal fluids suggests that anthropogenic activity could affect the style of faulting.

  19. Geological, Geophysical, And Thermal Characteristics Of The Salton Sea Geothermal Field, California

    Energy Technology Data Exchange (ETDEWEB)

    Younker, L.W.; Kasameyer, P. W.; Tewhey, J. D.

    1981-01-01

    The Salton Sea Geothermal Field is the largest water-dominated geothermal field in the Salton Trough in Southern California. Within the trough, local zones of extension among active right-stepping right-lateral strike-slip faults allow mantle-derived magmas to intrude the sedimentary sequence. The intrusions serves as heat sources to drive hydrothermal systems. We can characterize the field in detail because we have an extensive geological and geophysical data base. The sediments are relatively undeformed and can be divided into three categories as a function of depth: (1) low-permeability cap rock, (2) upper reservoir rocks consisting of sandstones, siltstones, and shales that were subject to minor alterations, and (3) lower reservoir rocks that were extensively altered. Because of the alteration, intergranular porosity and permeability are reduced with depth. permeability is enhanced by renewable fractures, i.e., fractures that can be reactivated by faulting or natural hydraulic fracturing subsequent to being sealed by mineral deposition. In the central portion of the field, temperature gradients are high near the surface and lower below 700 m. Surface gradients in this elliptically shaped region are fairly constant and define a thermal cap, which does not necessarily correspond to the lithologic cap. At the margin of the field, a narrow transition region, with a low near-surface gradient and an increasing gradient at greater depths, separates the high temperature resource from areas of normal regional gradient. Geophysical and geochemical evidence suggest that vertical convective motion in the reservoir beneath the thermal cap is confined to small units, and small-scale convection is superimposed on large-scale lateral flow of pore fluid. Interpretation of magnetic, resistivity, and gravity anomalies help to establish the relationship between the inferred heat source, the hydrothermal system, and the observed alteration patterns. A simple hydrothermal model is

  20. Seismic calibration shots conducted in 2009 in the Imperial Valley, southern California, for the Salton Seismic Imaging Project (SSIP)

    Science.gov (United States)

    Murphy, Janice; Goldman, Mark; Fuis, Gary; Rymer, Michael; Sickler, Robert; Miller, Summer; Butcher, Lesley; Ricketts, Jason; Criley, Coyn; Stock, Joann; Hole, John; Chavez, Greg

    2011-01-01

    Rupture of the southern section of the San Andreas Fault, from the Coachella Valley to the Mojave Desert, is believed to be the greatest natural hazard facing California in the near future. With an estimated magnitude between 7.2 and 8.1, such an event would result in violent shaking, loss of life, and disruption of lifelines (freeways, aqueducts, power, petroleum, and communication lines) that would bring much of southern California to a standstill. As part of the Nation's efforts to prevent a catastrophe of this magnitude, a number of projects are underway to increase our knowledge of Earth processes in the area and to mitigate the effects of such an event. One such project is the Salton Seismic Imaging Project (SSIP), which is a collaborative venture between the United States Geological Survey (USGS), California Institute of Technology (Caltech), and Virginia Polytechnic Institute and State University (Virginia Tech). This project will generate and record seismic waves that travel through the crust and upper mantle of the Salton Trough. With these data, we will construct seismic images of the subsurface, both reflection and tomographic images. These images will contribute to the earthquake-hazard assessment in southern California by helping to constrain fault locations, sedimentary basin thickness and geometry, and sedimentary seismic velocity distributions. Data acquisition is currently scheduled for winter and spring of 2011. The design and goals of SSIP resemble those of the Los Angeles Region Seismic Experiment (LARSE) of the 1990's. LARSE focused on examining the San Andreas Fault system and associated thrust-fault systems of the Transverse Ranges. LARSE was successful in constraining the geometry of the San Andreas Fault at depth and in relating this geometry to mid-crustal, flower-structure-like decollements in the Transverse Ranges that splay upward into the network of hazardous thrust faults that caused the 1971 M 6.7 San Fernando and 1987 M 5

  1. Investigations of a large scale eared grebe (Podiceps nigricollis) die-off at the Salton Sea, California in 1992

    Science.gov (United States)

    Meteyer, C.U.; Audet, D.J.; Rocke, T.E.; Radke, W.; Creekmore, L.H.; Duncan, R.

    2004-01-01

    An estimated 150,000 Eared Grebes (Podiceps nigricollis) died at the Salton Sea between 16 December 1991 and 21 April 1992. This represented the largest documented mortality event of Eared Grebes at the time and approximately 6% of the North American population. During the die-off, grebes exhibited several uncharacteristic behaviors, such as congregating at freshwater tributaries, repeatedly gulping freshwater, preening excessively, moving onto land, and allowing close approach and/or capture. Avian cholera was diagnosed in Eared Grebes collected along the north and west shoreline of the Sea late in the die-off but not from the majority of the Eared Grebes dying along the south shore. Gross and histological examinations and diagnostic testing for viruses, bacteria, and parasites did not identify the cause of mortality in the majority of Eared Grebes examined from the south shore of the Sea. Liver concentrations of arsenic, chromium, DDE, mercury, selenium, and zinc were elevated in some Eared Grebes, but none of those contaminants exceeded known thresholds for independent lethality. Poisoning by heavy metals, organochlorine, organophosphorus, or carbamate pesticides, avian botulism, and salt were ruled out as the cause of mortality. Hypotheses for the die-off are interactive effects of contaminants, immunosuppression, a yet unidentified biotoxin or pathogen present in the Salton Sea, impairment of feather waterproofing leading to hypothermia, or a unique manifestation of avian cholera that evades laboratory detection.

  2. Water quality in the New River from Calexico to the Salton Sea, Imperial County, California

    Science.gov (United States)

    Setmire, James G.

    1984-01-01

    The New River enters the United States at Calexico, Calif., after it crosses the international boundary. Water-quality data from routine collection indicated that the New River was degraded by high organic and bacterial content. Intensive sampling for chemical and physical constituents and properties of the river was done May 9-13, 1977, to quantify the chemical composition of the water and to identify water-quality problems. Concentrations of total organic carbon in the New River at Calexico ranged from 80 to 161 milligrams per liter and dissolved organic carbon ranged from 34 to 42 milligrams per liter; the maximum chemical oxygen demand was 510 milligrams per liter. Intensive sampling for chemical and biological characteristics was done in the New River from May 1977 to June 1978 to determine the occurrence of the organic material and its effects on downstream water quality. Dissolved-oxygen concentration was measured along longitudinal profiles of the river from Calexico to the Salton Sea. A dissolved-oxygen sag downstream from the Calexico gage varied seasonally. The sag extended farther downstream and had lower concentrations of dissolved oxygen during the summer months than during the winter months. The sag of zero dissolved-oxygen concentration extended 26 miles in July 1977. In December 1976, the sag extended 20 miles but the minimum dissolved-oxygen concentration was 2.5 milligrams per liter. The greatest diel (24-hour) variation in dissolved-oxygen concentration occurred in the reach from the Calexico gage to Lyons Crossing, 8.8 miles downstream. High concentrations of organic material were detected as far as Highway 80, 19.5 miles downstream from the international boundary. Biological samples analyzed for benthic invertebrates showed that water at the Calexico and Lyons Crossing sites, nearest the international boundary, was of such poor quality that very few bottom-dwelling organisms could survive. Although the water was of poor quality at Keystone

  3. Monitoring reservoir response to earthquakes and fluid extraction, Salton Sea geothermal field, California.

    Science.gov (United States)

    Taira, Taka'aki; Nayak, Avinash; Brenguier, Florent; Manga, Michael

    2018-01-01

    Continuous monitoring of in situ reservoir responses to stress transients provides insights into the evolution of geothermal reservoirs. By exploiting the stress dependence of seismic velocity changes, we investigate the temporal evolution of the reservoir stress state of the Salton Sea geothermal field (SSGF), California. We find that the SSGF experienced a number of sudden velocity reductions (~0.035 to 0.25%) that are most likely caused by openings of fractures due to dynamic stress transients (as small as 0.08 MPa and up to 0.45 MPa) from local and regional earthquakes. Depths of velocity changes are estimated to be about 0.5 to 1.5 km, similar to the depths of the injection and production wells. We derive an empirical in situ stress sensitivity of seismic velocity changes by relating velocity changes to dynamic stresses. We also observe systematic velocity reductions (0.04 to 0.05%) during earthquake swarms in mid-November 2009 and late-December 2010. On the basis of volumetric static and dynamic stress changes, the expected velocity reductions from the largest earthquakes with magnitude ranging from 3 to 4 in these swarms are less than 0.02%, which suggests that these earthquakes are likely not responsible for the velocity changes observed during the swarms. Instead, we argue that velocity reductions may have been induced by poroelastic opening of fractures due to aseismic deformation. We also observe a long-term velocity increase (~0.04%/year) that is most likely due to poroelastic contraction caused by the geothermal production. Our observations demonstrate that seismic interferometry provides insights into in situ reservoir response to stress changes.

  4. Monitoring reservoir response to earthquakes and fluid extraction, Salton Sea geothermal field, California

    Science.gov (United States)

    Taira, Taka’aki; Nayak, Avinash; Brenguier, Florent; Manga, Michael

    2018-01-01

    Continuous monitoring of in situ reservoir responses to stress transients provides insights into the evolution of geothermal reservoirs. By exploiting the stress dependence of seismic velocity changes, we investigate the temporal evolution of the reservoir stress state of the Salton Sea geothermal field (SSGF), California. We find that the SSGF experienced a number of sudden velocity reductions (~0.035 to 0.25%) that are most likely caused by openings of fractures due to dynamic stress transients (as small as 0.08 MPa and up to 0.45 MPa) from local and regional earthquakes. Depths of velocity changes are estimated to be about 0.5 to 1.5 km, similar to the depths of the injection and production wells. We derive an empirical in situ stress sensitivity of seismic velocity changes by relating velocity changes to dynamic stresses. We also observe systematic velocity reductions (0.04 to 0.05%) during earthquake swarms in mid-November 2009 and late-December 2010. On the basis of volumetric static and dynamic stress changes, the expected velocity reductions from the largest earthquakes with magnitude ranging from 3 to 4 in these swarms are less than 0.02%, which suggests that these earthquakes are likely not responsible for the velocity changes observed during the swarms. Instead, we argue that velocity reductions may have been induced by poroelastic opening of fractures due to aseismic deformation. We also observe a long-term velocity increase (~0.04%/year) that is most likely due to poroelastic contraction caused by the geothermal production. Our observations demonstrate that seismic interferometry provides insights into in situ reservoir response to stress changes. PMID:29326977

  5. Atmospheric dry deposition in the vicinity of the Salton Sea, California - I: Air pollution and deposition in a desert environment

    Science.gov (United States)

    Alonso, R.; Bytnerowicz, A.; Boarman, W.I.

    2005-01-01

    Air pollutant concentrations and atmospheric dry deposition were monitored seasonally at the Salton Sea, southern California. Measurements of ozone (O 3), nitric acid vapor (HNO3), ammonia (NH3), nitric oxide (NO), nitrogen dioxide (NO2) and sulfur dioxide (SO 2) were performed using passive samplers. Deposition rates of NO 3-, NH4+, Cl-, SO 42-, Na+, K+ and Ca2+ to creosote bush branches and nylon filters as surrogate surfaces were determined for one-week long exposure periods. Maximum O3 values were recorded in spring with 24-h average values of 108.8 ??g m-3. Concentrations of NO and NO2 were low and within ranges of the non-urban areas in California (0.4-5.6 and 3.3-16.2 ??g m-3 ranges, respectively). Concentrations of HNO3 (2.0-6.7 ??g m-3) and NH 3 (6.4-15.7 ??g m-3) were elevated and above the levels typical for remote locations in California. Deposition rates of Cl-, SO42-, Na+, K+ and Ca2+ were related to the influence of sea spray or to suspended soil particles, and no strong enrichments caused by ions originated by human activities were detected. Dry deposition rates of NO3- and NH4+ were similar to values registered in areas where symptoms of nitrogen saturation and changes in species composition have been described. Deposition of nitrogenous compounds might be contributing to eutrophication processes at the Salton Sea. ?? 2005 Elsevier Ltd. All rights reserved.

  6. Analysis of P- and S-wave VSP (vertical seismic profile) data from the Salton Sea Geothermal Field

    Energy Technology Data Exchange (ETDEWEB)

    Daley, T.M.

    1987-09-01

    To understand any geophysical data, geologic information is necessary. This thesis will begin with a summary of the geology of the Salton Trough region and the Salton Sea Geothermal Field (SSGF). The information available from the SSSDP will also be summarized. After the geologic summary, the design of the VSP will be discussed, including acquisition equipment and procedures. The data processing procedures and software used will be discussed as a separate section. Processing procedures will also be described at various times in the thesis where more specialized procedures are used. Data analysis makes up the bulk of the thesis and it is divided into a number of sections detailing the basic VSP interpretation, the anisotropy analysis and the fracture detection and orientation analysis. A combined interpretation of the results, with probable geologic causes for observed events, is presented as a separate section from the data analysis. Finally, a summary of results for each of the goals stated above will be given. The reader should note that a large volume of data were collected and various display methods were used (from the standard wiggle-trace to three-component hodographs). Much of these data are left in the appendices with important or representative figures given in the body of the thesis. Also given in the appendices are listings of FORTRAN programs developed in conjunction with the thesis work. 46 refs., 63 figs., 12 tabs.

  7. Relationships among seismic velocity, metamorphism, and seismic and aseismic fault slip in the Salton Sea Geothermal Field region

    Science.gov (United States)

    McGuire, Jeffrey J.; Lohman, Rowena B.; Catchings, Rufus D.; Rymer, Michael J.; Goldman, Mark R.

    2015-01-01

    The Salton Sea Geothermal Field is one of the most geothermally and seismically active areas in California and presents an opportunity to study the effect of high-temperature metamorphism on the properties of seismogenic faults. The area includes numerous active tectonic faults that have recently been imaged with active source seismic reflection and refraction. We utilize the active source surveys, along with the abundant microseismicity data from a dense borehole seismic network, to image the 3-D variations in seismic velocity in the upper 5 km of the crust. There are strong velocity variations, up to ~30%, that correlate spatially with the distribution of shallow heat flow patterns. The combination of hydrothermal circulation and high-temperature contact metamorphism has significantly altered the shallow sandstone sedimentary layers within the geothermal field to denser, more feldspathic, rock with higher P wave velocity, as is seen in the numerous exploration wells within the field. This alteration appears to have a first-order effect on the frictional stability of shallow faults. In 2005, a large earthquake swarm and deformation event occurred. Analysis of interferometric synthetic aperture radar data and earthquake relocations indicates that the shallow aseismic fault creep that occurred in 2005 was localized on the Kalin fault system that lies just outside the region of high-temperature metamorphism. In contrast, the earthquake swarm, which includes all of the M > 4 earthquakes to have occurred within the Salton Sea Geothermal Field in the last 15 years, ruptured the Main Central Fault (MCF) system that is localized in the heart of the geothermal anomaly. The background microseismicity induced by the geothermal operations is also concentrated in the high-temperature regions in the vicinity of operational wells. However, while this microseismicity occurs over a few kilometer scale region, much of it is clustered in earthquake swarms that last from

  8. Total selenium and selenium species in irrigation drain inflows to the Salton Sea, California, April and July 2007

    Science.gov (United States)

    May, Thomas W.; Walther, Michael J.; Saiki, Michael K.; Brumbaugh, William G.

    2007-01-01

    This report presents the results for two sampling periods during a 4-year monitoring survey to provide a characterization of selenium concentrations in selected irrigation drains flowing into the Salton Sea, California. Total selenium, selenium species, and total suspended solids were determined in water samples, and total selenium was determined in sediment, detritus, and biota that included algae, plankton, midge larvae (family, Chironomidae), and two fish species-western mosquitofish (Gambusia affinis), and sailfin molly (Poecilia latipinna). In addition, sediments were analyzed for percent total organic carbon and particle size. Total selenium concentrations in water for both sampling periods ranged from 1.43 to 47.1 micrograms per liter, predominately as selenate, which is typical of waters leached out of selenium-contaminated marine shales under alkaline and oxidizing conditions. Total selenium concentrations ranged from 0.88 to 20.2 micrograms per gram in biota, and from 0.15 to 28.9 micrograms per gram in detritus and sediment.

  9. Total selenium and selenium species in irrigation drain inflows to the Salton Sea, California, October 2008 and January 2009

    Science.gov (United States)

    May, Thomas W.; Walther, Michael J.; Saiki, Michael K.; Brumbaugh, William G.

    2009-01-01

    This report presents the results for two sampling periods (October 2008 and January 2009) during a 4-year monitoring program to characterize selenium concentrations in selected irrigation drains flowing into the Salton Sea, California. Total selenium, selenium species (dissolved selenite, selenate, organoselenium), and total suspended solids were determined in water samples. Total selenium also was determined in water column particulates and in sediment, detritus, and biota that included algae, plankton, midge larvae (family, Chironomidae), and two fish species (western mosquitofish, Gambusia affinis, and sailfin molly, Poecilia latipinna). In addition, sediments were analyzed for percent total organic carbon and particle size. Mean total selenium concentrations in water for both sampling periods ranged from 1.00 to 33.6 micrograms per liter, predominately as selenate, which is typical of waters where selenium is leached out of selenium-containing marine shales and associated soils under alkaline and oxidizing conditions. Total selenium concentrations (micrograms per gram dry weight) ranged as follows: algae, 1.52 to 8.26; plankton, 0.79 to 3.66; midges, 2.68 to 50.6; fish, 3.09 to 30.4; detritus, 1.78 to 58.0; and sediment, 0.42 to 10.0.

  10. Total selenium and selenium species in irrigation drain inflows to the Salton Sea, California, October 2007 and January 2008

    Science.gov (United States)

    May, Thomas W.; Walther, Michael J.; Saiki, Michael K.; Brumbaugh, William G.

    2008-01-01

    This report presents the results for two sampling periods (October 2007 and January 2008) during a 4-year monitoring program to characterize selenium concentrations in selected irrigation drains flowing into the Salton Sea, California. Total selenium, selenium species (selenite, selenate, organoselenium), and total suspended solids were determined in water samples, and total selenium was determined in sediment, detritus, and biota that included algae, plankton, midge larvae (family, Chironomidae), and two fish species?western mosquitofish (Gambusia affinis) and sailfin molly (Poecilia latipinna). In addition, sediments were analyzed for percent total organic carbon and particle size. Mean total selenium concentrations in water for both sampling periods ranged from 0.97 to 64.5 micrograms per liter, predominately as selenate, which is typical of waters where selenium is leached out of selenium-containing marine shales and associated soils under alkaline and oxidizing conditions. Total selenium concentrations (micrograms per gram dry weight) ranged as follows: algae, 0.95 to 5.99; plankton, 0.15 to 19.3; midges, 1.39 to 15.4; fish, 3.71 to 25.1; detritus, 0.85 to 21.7; sediment, 0.32 to 7.28.

  11. Total selenium and selenium species in irrigation drain inflows to the Salton Sea, California, April and July 2008

    Science.gov (United States)

    May, Thomas W.; Walther, Michael J.; Saiki, Michael K.; Brumbaugh, William G.

    2009-01-01

    This report presents the results for two sampling periods (April 2008 and July 2008) during a 4-year monitoring program to characterize selenium concentrations in selected irrigation drains flowing into the Salton Sea, California. Total selenium, selenium species (dissolved selenite, selenate, organoselenium), and total suspended solids were determined in water samples and total selenium was determined in water column particulates and in sediment, detritus, and biota that included algae, plankton, midge larvae (family, Chironomidae), and two fish species - western mosquitofish (Gambusia affinis) and sailfin molly (Poecilia latipinna). In addition, sediments were analyzed for percent total organic carbon and particle size. Mean total selenium concentrations in water for both sampling periods ranged from 1.93 to 44.2 micrograms per liter, predominately as selenate, which is typical of waters where selenium is leached out of selenium-containing marine shales and associated soils under alkaline and oxidizing conditions. Total selenium concentrations (micrograms per gram dry weight) ranged as follows: algae, 0.75 to 3.39; plankton, 0.88 to 4.03; midges, 2.52 to 44.3; fish, 3.37 to 18.9; detritus, 1.11 to 13.6; sediment, 0.11 to 8.93.

  12. Double-diffusive convection in geothermal systems: the salton sea, California, geothermal system as a likely candidate

    Science.gov (United States)

    Fournier, R.O.

    1990-01-01

    Much has been published about double-diffusive convection as a mechanism for explaining variations in composition and temperature within all-liquid natural systems. However, relatively little is known about the applicability of this phenomenon within the heterogeneous rocks of currently active geothermal systems where primary porosity may control fluid flow in some places and fractures may control it in others. The main appeal of double-diffusive convection within hydrothermal systems is-that it is a mechanism that may allow efficient transfer of heat mainly by convection, while at the same time maintaining vertical and lateral salinity gradients. The Salton Sea geothermal system exhibits the following reservoir characteristics: (1) decreasing salinity and temperature from bottom to top and center toward the sides, (2) a very high heat flow from the top of the system that seems to require a major component of convective transfer of heat within the chemically stratified main reservoir, and (3) a relatively uniform density of the reservoir fluid throughout the system at all combinations of subsurface temperature, pressure, and salinity. Double-diffusive convection can account for these characteristics very nicely whereas other previously suggested models appear to account either for the thermal structure or for the salinity variations, but not both. Hydrologists, reservoir engineers, and particularly geochemists should consider the possibility and consequences of double-diffusive convection when formulating models of hydrothermal processes, and of the response of reservoirs to testing and production. ?? 1990.

  13. Reservoir engineering report for the magma-SDG and E geothermal experimental site near the Salton Sea, California

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, R.C.

    1976-07-12

    A description of the Salton Sea geothermal reservoir is given and includes approximate fault locations, geology (lithology), temperatures, and estimates of the extent of the reservoir. The reservoir's temperatures and chemical composition are also reviewed. The flow characteristics are discussed after analyses of drillstem tests and extended well tests. The field production, reserves and depletion are estimated, and the effects of fractures on flow and depletion are discussed. The reservoir is believed to be separated into an ''upper'' and ''lower'' portion by a relatively thick and continuous shale layer. The upper reservoir is highly porous, with high permeability and productivity. The lower reservoir is at least twice as large as the upper but has much lower storativity and permeability in the rock matrix. The lower reservoir may be highly fractured, and its temperatures and dissolved solids are greater than those of the upper reservoir. The proven reserves of heat in the upper reservoir are about /sup 1///sub 4/ GW.yr (in the fluid) and /sup 1///sub 3/ GW.yr (in the rock). In the lower reservoir the proven reserves of heat are 5/sup 3///sub 4/ GW.yr (in the fluid) and 17 GW.yr (in the rock). Unproven reserves greatly exceed these numbers. Injection tests following well completion imply that hydraulic fracturing has taken place in two of the SDG and E wells and at least one other well nearby.

  14. Salton Sea Geothermal Field, California, as a near-field natural analog of a radioactive waste repository in salt

    Energy Technology Data Exchange (ETDEWEB)

    Elders, W.A.; Cohen, L.H.

    1983-11-01

    Since high concentrations of radionuclides and high temperatures are not normally encountered in salt domes or beds, finding an exact geologic analog of expected near-field conditions in a mined nuclear waste repository in salt will be difficult. The Salton Sea Geothermal Field, however, provides an opportunity to investigate the migration and retardation of naturally occurring U, Th, Ra, Cs, Sr and other elements in hot brines which have been moving through clay-rich sedimentary rocks for up to 100,000 years. The more than thirty deep wells drilled in this field to produce steam for electrical generation penetrate sedimentary rocks containing concentrated brines where temperatures reach 365/sup 0/C at only 2 km depth. The brines are primarily Na, K, Ca chlorides with up to 25% of total dissolved solids; they also contain high concentrations of metals such as Fe, Mn, Li, Zn, and Pb. This report describes the geology, geophysics and geochemistry of this system as a prelude to a study of the mobility of naturally occurring radionuclides and radionuclide analogs within it. The aim of this study is to provide data to assist in validating quantitative models of repository behavior and to use in designing and evaluating waste packages and engineered barriers. 128 references, 33 figures, 13 tables.

  15. Discovering new events beyond the catalogue—application of empirical matched field processing to Salton Sea geothermal field seismicity

    Science.gov (United States)

    Wang, Jingbo; Templeton, Dennise C.; Harris, David B.

    2015-10-01

    Using empirical matched field processing (MFP), we compare 4 yr of continuous seismic data to a set of 195 master templates from within an active geothermal field and identify over 140 per cent more events than were identified using traditional detection and location techniques alone. In managed underground reservoirs, a substantial fraction of seismic events can be excluded from the official catalogue due to an inability to clearly identify seismic-phase onsets. Empirical MFP can improve the effectiveness of current seismic detection and location methodologies by using conventionally located events with higher signal-to-noise ratios as master events to define wavefield templates that could then be used to map normally discarded indistinct seismicity. Since MFP does not require picking, it can be carried out automatically and rapidly once suitable templates are defined. In this application, we extend MFP by constructing local-distance empirical master templates using Southern California Earthquake Data Center archived waveform data of events originating within the Salton Sea Geothermal Field. We compare the empirical templates to continuous seismic data collected between 1 January 2008 and 31 December 2011. The empirical MFP method successfully identifies 6249 additional events, while the original catalogue reported 4352 events. The majority of these new events are lower-magnitude events with magnitudes between M0.2-M0.8. The increased spatial-temporal resolution of the microseismicity map within the geothermal field illustrates how empirical MFP, when combined with conventional methods, can significantly improve seismic network detection capabilities, which can aid in long-term sustainability and monitoring of managed underground reservoirs.

  16. In-Flight Validation of Mid and Thermal Infrared Remotely Sensed Data Using the Lake Tahoe and Salton Sea Automated Validation Sites

    Science.gov (United States)

    Hook, Simon J.

    2008-01-01

    The presentation includes an introduction, Lake Tahoe site layout and measurements, Salton Sea site layout and measurements, field instrument calibration and cross-calculations, data reduction methodology and error budgets, and example results for MODIS. Summary and conclusions are: 1) Lake Tahoe CA/NV automated validation site was established in 1999 to assess radiometric accuracy of satellite and airborne mid and thermal infrared data and products. Water surface temperatures range from 4-25C.2) Salton Sea CA automated validation site was established in 2008 to broaden range of available water surface temperatures and atmospheric water vapor test cases. Water surface temperatures range from 15-35C. 3) Sites provide all information necessary for validation every 2 mins (bulk temperature, skin temperature, air temperature, wind speed, wind direction, net radiation, relative humidity). 4) Sites have been used to validate mid and thermal infrared data and products from: ASTER, AATSR, ATSR2, MODIS-Terra, MODIS-Aqua, Landsat 5, Landsat 7, MTI, TES, MASTER, MAS. 5) Approximately 10 years of data available to help validate AVHRR.

  17. New insights into North America-Pacific Plate boundary deformation from Lake Tahoe, Salton Sea and southern Baja California

    Science.gov (United States)

    Brothers, Daniel Stephen

    Five studies along the Pacific-North America (PA-NA) plate boundary offer new insights into continental margin processes, the development of the PA-NA tectonic margin and regional earthquake hazards. This research is based on the collection and analysis of several new marine geophysical and geological datasets. Two studies used seismic CHIRP surveys and sediment coring in Fallen Leaf Lake (FLL) and Lake Tahoe to constrain tectonic and geomorphic processes in the lakes, but also the slip-rate and earthquake history along the West Tahoe-Dollar Point Fault. CHIRP profiles image vertically offset and folded strata that record deformation associated with the most recent event (MRE). Radiocarbon dating of organic material extracted from piston cores constrain the age of the MRE to be between 4.1--4.5 k.y. B.P. Offset of Tioga aged glacial deposits yield a slip rate of 0.4--0.8 mm/yr. An ancillary study in FLL determined that submerged, in situ pine trees that date to between 900-1250 AD are related to a medieval megadrought in the Lake Tahoe Basin. The timing and severity of this event match medieval megadroughts observed in the western United States and in Europe. CHIRP profiles acquired in the Salton Sea, California provide new insights into the processes that control pull-apart basin development and earthquake hazards along the southernmost San Andreas Fault. Differential subsidence (>10 mm/yr) in the southern sea suggests the existence of northwest-dipping basin-bounding faults near the southern shoreline. In contrast to previous models, the rapid subsidence and fault architecture observed in the southern part of the sea are consistent with experimental models for pull-apart basins. Geophysical surveys imaged more than 15 ˜N15°E oriented faults, some of which have produced up to 10 events in the last 2-3 kyr. Potentially 2 of the last 5 events on the southern San Andreas Fault (SAF) were synchronous with rupture on offshore faults, but it appears that ruptures on

  18. Occurrence, distribution, and transport of pesticides, trace elements, and selected inorganic constituents into the Salton Sea Basin, California, 2001-2002

    Science.gov (United States)

    LeBlanc, Lawrence A.; Schroeder, Roy A.; Orlando, James L.; Kuivila, Kathyrn M.

    2004-01-01

    A study of pesticide distribution and transport within the Salton Sea Basin, California, was conducted from September 2001 to October 2002. Sampling for the study was done along transects for the three major rivers that flow into the Salton Sea Basin: the New and Alamo Rivers at the southern end of the basin and the Whitewater River at the northern end. Three stations were established on each river: an outlet station approximately 1 mile upstream of the river discharge, a near-shore station in the river delta, and off-shore station in the Salton Sea. Water and suspended and bed sediments were collected at each station in October 2001, March-April 2002, and September 2002, coinciding with peak pesticide applications in the fall and spring. Fourteen current-use pesticides were detected in the water column. Concentrations of dissolved pesticides typically decreased from the outlets to the sea in all three rivers, consistent with the off-shore transport of pesticides from the rivers to the sea. Dissolved concentrations ranged from the limits of detection to 151 nanograms per liter (ng/L); however, diazinon, eptam (EPTC), and malathion were detected at much higher concentrations (940?3,830 ng/L) at the New and Alamo River outlet and near-shore stations. Concentrations of carbaryl, dacthal, diazinon, and eptam were higher during the two fall sampling periods, whereas concentrations of atrazine, carbofuran, and trifluralin were higher during the spring. Current-use pesticides also were detected on suspended and bed sediments in concentrations ranging from method detection limits to 106 ng/g (nanograms per gram). Chlorpyrifos, dacthal, eptam, trifluralin, and DDE were the most frequently detected pesticides on sediments from all three rivers. The number and concentrations of pesticides associated with suspended sediments frequently were similar for the river outlet and near-shore sites, consistent with the downstream transport of sediment-associated pesticides out of the

  19. Continental rupture and the creation of new crust in the Salton Trough rift, Southern California and northern Mexico: Results from the Salton Seismic Imaging Project

    Science.gov (United States)

    Han, Liang; Hole, John A.; Stock, Joann M.; Fuis, Gary S.; Kell, Annie; Driscoll, Neal W.; Kent, Graham M.; Harding, Alistair J.; Rymer, Michael J.; González-Fernández, Antonio; Lázaro-Mancilla, Octavio

    2016-10-01

    A refraction and wide-angle reflection seismic profile along the axis of the Salton Trough, California and Mexico, was analyzed to constrain crustal and upper mantle seismic velocity structure during active continental rifting. From the northern Salton Sea to the southern Imperial Valley, the crust is 17-18 km thick and approximately one-dimensional. The transition at depth from Colorado River sediment to underlying crystalline rock is gradual and is not a depositional surface. The crystalline rock from 3 to 8 km depth is interpreted as sediment metamorphosed by high heat flow. Deeper felsic crystalline rock could be stretched preexisting crust or higher-grade metamorphosed sediment. The lower crust below 12 km depth is interpreted to be gabbro emplaced by rift-related magmatic intrusion by underplating. Low upper mantle velocity indicates high temperature and partial melting. Under the Coachella Valley, sediment thins to the north and the underlying crystalline rock is interpreted as granitic basement. Mafic rock does not exist at 12-18 km depth as it does to the south, and a weak reflection suggests Moho at 28 km depth. Structure in adjacent Mexico has slower midcrustal velocity, and rocks with mantle velocity must be much deeper than in the Imperial Valley. Slower velocity and thicker crust in the Coachella and Mexicali valleys define the rift zone between them to be >100 km wide in the direction of plate motion. North American lithosphere in the central Salton Trough has been rifted apart and is being replaced by new crust created by magmatism, sedimentation, and metamorphism.

  20. A Strategy for Interpretation of Microearthquake Tomography Results in the Salton Sea Geothermal Field Based upon Rock Physics Interpretations of State 2-14 Borehole Logs

    Energy Technology Data Exchange (ETDEWEB)

    Bonner, B; Hutchings, L; Kasameyer, P

    2006-06-14

    We devise a strategy for analysis of Vp and Vs microearthquake tomography results in the Salton Sea geothermal field to identify important features of the geothermal reservoir. We first interpret rock properties in State 2-14 borehole based upon logged core through the reservoir. Then, we interpret seismic recordings in the well (Daley et al., 1988) to develop the strategy. We hypothesize that mapping Poisson's ratio has two applications for the Salton Sea geothermal reservoir: (1) to map the top of the reservoir, and (2) as a diagnostic for permeable zones. Poisson's ratio can be obtained from Vp and Vs. In the State 2-14 borehole, Poisson's ratio calculated from large scale averages ({approx} 150 m) shows a monotonic decrease with depth to about 1300 m, at which point it increases with depth. Our model is that the monotonic decrease is due to compaction, and the increase below 1300 m is due to the rocks being hydrothermally altered. We hypothesize we can map the depth to alteration by identifying the transition from decreasing to increasing values; and thus, map the top of the reservoir, which is associated with a known increase in sulfite, chlorite, and epidote alteration that may be indicative of hydrothermal activity. We also observe (from Daley et. al. plots) an anomalous drop in Poisson's ratio at a depth of about 900 m, within a sandstone formation. The sandstone has a P-wave velocity significantly higher than the siltstone above it but a lower velocity in the lower half of the formation relative to the upper half. We interpret the relative decrease in velocity to be due to fracturing and chemical alteration caused by permeability. We conclude that using Vp and Vs tomography results to obtain images of Poisson's ratio has the potential to identify significant features in the geothermal reservoir in this geologic setting. Seismic attenuation tomography results (mapped as Qp and Qs) should also be useful for evaluating geothermal

  1. Calibration Shots Recorded for the Salton Seismic Imaging Project, Salton Trough, California

    Science.gov (United States)

    Murphy, J. M.; Rymer, M. J.; Fuis, G. S.; Stock, J. M.; Goldman, M.; Sickler, R. R.; Miller, S. A.; Criley, C. J.; Ricketts, J. W.; Hole, J. A.

    2009-12-01

    The Salton Seismic Imaging Project (SSIP) is a collaborative venture between the U.S. Geological Survey, California Institute of Technology, and Virginia Polytechnic Institute and State University, to acquire seismic reflection/wide angle refraction data, and currently is scheduled for data acquisition in 2010. The purpose of the project is to get a detailed subsurface 3-D image of the structure of the Salton Trough (including both the Coachella and Imperial Valleys) that can be used for earthquake hazards analysis, geothermal studies, and studies of the transition from ocean-ocean to continent-continent plate-boundary. In June 2009, a series of calibration shots were detonated in the southern Imperial Valley with specific goals in mind. First, these shots were used to measure peak particle velocity and acceleration at various distances from the shots. Second, the shots were used to calibrate the propagation of energy through sediments of the Imperial Valley. Third, the shots were used to test the effects of seismic energy on buried clay drainage pipes, which are abundant throughout the irrigated parts of the Salton Trough. Fourth, we tested the ODEX drilling technique, which uses a down-hole casing hammer for a tight casing fit. Information obtained from the calibration shots will be used for final planning of the main project. The shots were located in an unused field adjacent to Hwy 7, about 6 km north of the U.S. /Mexican border (about 18 km southeast of El Centro). Three closely spaced shot points (16 meters apart) were aligned N-S and drilled to 21-m, 23.5-m, and 27-m depth. The holes were filled with 23-kg, 68-kg, and 123-kg of ammonium-nitrate explosive, respectively. Four instrument types were used to record the seismic energy - six RefTek RT130 6-channel recorders with a 3-component accelerometer and a 3-component 2-Hz velocity sensor, seven RefTek RT130 3-channel recorders with a 3-component 4.5-Hz velocity sensor, 35 Texans with a vertical component 4

  2. Assessment of geothermal development in the Imperial Valley of California. Volume 1. Environment, health, and socioeconomics

    Energy Technology Data Exchange (ETDEWEB)

    Layton, D. (ed.)

    1980-07-01

    Utilization of the Imperial Valley's geothermal resources to support energy production could be hindered if environmental impacts prove to be unacceptable or if geothermal operations are incompatible with agriculture. To address these concerns, an integrated environmental and socioeconomic assessment of energy production in the valley was prepared. The most important impacts examined in the assessment involved air quality changes resulting from emissions of hydrogen sulfide, and increases in the salinity of the Salton Sea resulting from the use of agricultural waste waters for power plant cooling. The socioeconomics consequences of future geothermal development will generally be beneficial. (MHR)

  3. Plate boundary deformation at the latitude of the Salton Trough - northern Gulf of California (Invited)

    Science.gov (United States)

    Stock, J. M.

    2013-12-01

    Along the Pacific-North America plate boundary zone, the segment including the southern San Andreas fault to Salton Trough and northern Gulf of California basins has been transtensional throughout its evolution, based on Pacific-North America displacement vectors calculated from the global plate circuit (900 × 20 km at N54°W since 20 Ma; 460 × 20 km at N48°W since 11 Ma). Nevertheless, active seismicity and focal mechanisms show a broad zone of plate boundary deformation within which the inferred stress regime varies locally (Yang & Hauksson 2013 GJI), and fault patterns in some regions suggest ongoing tectonic rotation. Similar behavior is inferred to have occurred in this zone over most of its history. Crustal structure in this region is constrained by surface geology, geophysical experiments (e.g., the 2011 Salton Seismic Imaging Project (SSIP), USGS Imperial Valley 1979, PACE), and interdisciplinary marine and onland studies in Mexico (e.g., NARS-Baja, Cortes, and surveys by PEMEX). Magnetic data (e.g., EMAG-2) aids in the recognition of large-scale crustal provinces and fault boundaries in regions lacking detailed geophysical surveys. Consideration of existing constraints on crustal thickness and architecture, and fault and basin evolution suggests that to reconcile geological deformation with plate motion history, the following additional factors need to be taken into account. 1) Plate boundary displacement via interacting systems of rotating blocks, coeval with slip on steep strike slip faults, and possibly related to slip on low angle extensional faults (e.g, Axen & Fletcher 1998 IGR) may be typical prior to the onset of seafloor spreading. This fault style may have accommodated up to 150 km of plate motion in the Mexican Continental Borderland and north of the Vizcaino Peninsula, likely between 12 and 15 Ma, as well as explaining younger rotations adjacent to the Gulf of California and current deformation southwest of the Salton Sea. 2) Geophysical

  4. Foehn-induced effects on local dust pollution, frontal clouds and solar radiation in the Dead Sea valley

    Science.gov (United States)

    Kishcha, Pavel; Starobinets, Boris; Savir, Amit; Alpert, Pinhas; Kaplan, Michael

    2017-03-01

    Despite the long history of investigation of foehn phenomena, there are few studies of the influence of foehn winds on air pollution and none in the Dead Sea valley. For the first time the foehn phenomenon and its effects on local dust pollution, frontal cloudiness and surface solar radiation were analyzed in the Dead Sea valley, as it occurred on 22 March 2013. This was carried out using both numerical simulations and observations. The foehn winds intensified local dust emissions, while the foehn-induced temperature inversion trapped dust particles beneath this inversion. These two factors caused extreme surface dust concentration in the western Dead Sea valley. The dust pollution was transported by west winds eastward, to the central Dead Sea valley, where the speed of these winds sharply decreased. The transported dust was captured by the ascending airflow contributing to the maximum aerosol optical depth (AOD) over the central Dead Sea valley. On the day under study, the maximum surface dust concentration did not coincide with the maximum AOD: this being one of the specific effects of the foehn phenomenon on dust pollution in the Dead Sea valley. Radar data showed a passage of frontal cloudiness through the area of the Dead Sea valley leading to a sharp drop in noon solar radiation. The descending airflow over the downwind side of the Judean Mountains led to the formation of a cloud-free band followed by only the partial recovery of solar radiation because of the extreme dust pollution caused by foehn winds.

  5. Borehole-explosion and air-gun data acquired in the 2011 Salton Seismic Imaging Project (SSIP), southern California: description of the survey

    Science.gov (United States)

    Rose, Elizabeth J.; Fuis, Gary S.; Stock, Joann M.; Hole, John A.; Kell, Annie M.; Kent, Graham; Driscoll, Neal W.; Goldman, Mark; Reusch, Angela M.; Han, Liang; Sickler, Robert R.; Catchings, Rufus D.; Rymer, Michael J.; Criley, Coyn J.; Scheirer, Daniel S.; Skinner, Steven M.; Slayday-Criley, Coye J.; Murphy, Janice M.; Jensen, Edward G.; McClearn, Robert; Ferguson, Alex J.; Butcher, Lesley A.; Gardner, Max A.; Emmons, Iain; Loughran, Caleb L.; Svitek, Joseph R.; Bastien, Patrick C.; Cotton, Joseph A.; Croker, David S.; Harding, Alistair J.; Babcock, Jeffrey M.; Harder, Steven H.; Rosa, Carla M.

    2013-01-01

    The Imperial and Coachella Valleys are being formed by active plate-tectonic processes. From the Imperial Valley southward into the Gulf of California, plate motions are rifting the continent apart. In the Coachella Valley, the plates are sliding past one another along the San Andreas and related faults (fig. 1). These processes build the stunning landscapes of the region, but also produce damaging earthquakes. Rupture of the southern section of the San Andreas Fault (SAF), from the Coachella Valley to the Mojave Desert, is believed to be the greatest natural hazard that California will face in the near future. With an estimated magnitude between 7.2 and 8.1, such an event would result in violent shaking, loss of life, and disruption of infrastructure (freeways, aqueducts, power, petroleum, and communication lines) that might bring much of southern California to a standstill. As part of the nation’s efforts to avert a catastrophe of this magnitude, a number of projects have been undertaken to more fully understand and mitigate the effects of such an event. The Salton Seismic Imaging Project (SSIP), funded jointly by the National Science Foundation (NSF) and the U.S. Geological Survey (USGS), seeks to understand, through seismic imaging, the structure of the Earth surrounding the SAF, including the sedimentary basins on which cities are built. The principal investigators (PIs) of this collaborative project represent the USGS, Virginia Polytechnic Institute and State University (Virginia Tech), California Institute of Technology (Caltech), Scripps Institution of Oceanography (Scripps), University of Nevada, Reno (UNR), and Stanford University. SSIP will create images of underground structure and sediments in the Imperial and Coachella Valleys and adjacent mountain ranges to investigate the earthquake hazards posed to cities in this area. Importantly, the images will help determine the underground geometry of the SAF, how deep the sediments are, and how fast

  6. Proglacial vs postglacial depostional environments, the opposing processes that filled the southern North Sea tunnel valleys

    DEFF Research Database (Denmark)

    Moreau, Julien; Huuse, Mads

    prograding north in opposing direction to the former ice flows whose south­ward flowing meltwater excavated the valleys. The first hypothesis, by analogy with some small eskers introduced the concept of backfilling where the eroded sediments upstream is deposited directly below the ice margin, in a conveyor...... challenged by new observations on the architecture of the valleys and their infill sediments which appear to show many similarities in common with deltaic clinoforms observed in the pre­glacial succession of the southern North Sea. The new model states that the incision and the filling of the valleys...... stratigraphic scheme is immense and a long run project, it would be unique for this period in the region. We intend to solve part of the problem by numerically reconstructing the local landscape with the ice sheet and its isostatic depression. This allows to represent a type-sequence helping the understanding...

  7. Integrated Modeling of Water Policy Futures in the Imperial-Mexicali Valleys

    Science.gov (United States)

    Kjelland, M. K.; Forster, C. B.; Grant, W. E.; Collins, K.

    2004-12-01

    Divided by an international border, the Imperial-Mexicali Valleys (IMVs) are linked by shared history, natural resources, culture and economy. This region is experiencing changes driven by policy makers both within and outside the IMVs. The largest external decision, the Colorado River Quantification Settlement Agreement (QSA) of 2003, opens the door to a laboratory for studying the consequences of a massive transfer of agricultural water to municipal users. Two irrigation districts, two urban water agencies and the State of California have agreed to a 75 year of more than 30 million acre-feet of Colorado River water from agricultural to urban use. Although Imperial Valley farmers will be compensated for water conservation and land fallowing, the economic, environmental and social consequences are unclear. Farmers who fallow will likely cause a greater impact on local businesses and government than those choosing on-field water conservation. Reduced agricultural water use causes reduced flow of irrigation runoff, at higher salinity than before, to the Salton Sea that, in turn, impacts the population dynamics of Ichthyan and Avian species at the Salton Sea. Municipal wastewater discharged into the New River by Mexicali, Mexico is also an important source of inflow to the Salton Sea that will be reduce by plans to reclaim the wastewater for various uses, including cooling water for two new power plants in the Mexicali. A restoration program is funded to produce a Sea with much reduced surface area. But this approach may, in turn, lead to increases in windblown dust from the dry lakebed that will contribute to an air basin already designated as a federal nonattainment area for particulate emissions. Additional water will be conserved by lining the All American and Coachella canals. But, eliminating seepage from the All American canal reduces groundwater recharge to aquifers used by Mexican farmers. A complex interplay of water-related issues must be accounted for if

  8. Salton Trough regional deformation estimated from combined trilateration and survey-mode GPS data

    Science.gov (United States)

    Anderson, G.; Agnew, D.C.; Johnson, H.O.

    2003-01-01

    The Salton Trough in southeastern California, United States, has one of the highest seismicity and deformation rates in southern California, including 20 earthquakes M 6 or larger since 1892. From 1972 through 1987, the U.S. Geological Survey (USGS) measured a 41-station trilateration network in this region. We remeasured 37 of the USGS baselines using survey-mode Global Positioning System methods from 1995 through 1999. We estimate the Salton Trough deformation field over a nearly 30-year period through combined analysis of baseline length time series from these two datasets. Our primary result is that strain accumulation has been steady over our observation span, at a resolution of about 0.05 ??strain/yr at 95% confidence, with no evidence for significant long-term strain transients despite the occurrence of seven large regional earthquakes during our observation period. Similar to earlier studies, we find that the regional strain field is consistent with 0.5 ?? 0.03 ??strain/yr total engineering shear strain along an axis oriented 311.6?? ?? 23?? east of north, approximately parallel to the strike of the major regional faults, the San Andreas and San Jacinto (all uncertainties in the text and tables are standard deviations unless otherwise noted). We also find that (1) the shear strain rate near the San Jacinto fault is at least as high as it is near the San Andreas fault, (2) the areal dilatation near the southeastern Salton Sea is significant, and (3) one station near the southeastern Salton Sea moved anomalously during the period 1987.95-1995.11.

  9. Fault zone characteristics and basin complexity in the southern Salton Trough, California

    Science.gov (United States)

    Persaud, Patricia; Ma, Yiran; Stock, Joann M.; Hole, John A.; Fuis, Gary S.; Han, Liang

    2016-01-01

    Ongoing oblique slip at the Pacific–North America plate boundary in the Salton Trough produced the Imperial Valley (California, USA), a seismically active area with deformation distributed across a complex network of exposed and buried faults. To better understand the shallow crustal structure in this region and the connectivity of faults and seismicity lineaments, we used data primarily from the Salton Seismic Imaging Project to construct a three-dimensional P-wave velocity model down to 8 km depth and a velocity profile to 15 km depth, both at 1 km grid spacing. A VP = 5.65–5.85 km/s layer of possibly metamorphosed sediments within, and crystalline basement outside, the valley is locally as thick as 5 km, but is thickest and deepest in fault zones and near seismicity lineaments, suggesting a causative relationship between the low velocities and faulting. Both seismicity lineaments and surface faults control the structural architecture of the western part of the larger wedge-shaped basin, where two deep subbasins are located. We estimate basement depths, and show that high velocities at shallow depths and possible basement highs characterize the geothermal areas.

  10. Water Transfers, Air Quality, Ecosystems and Population Growth at the US-Mexico Border: An Integrated Model of the Mexicali and Imperial Valleys

    Science.gov (United States)

    Forster, C. B.; Gonzalez, T.; Peach, J.; Kjelland, M.; Collins, K.; Grant, W. E.

    2006-12-01

    Borderland communities in the Imperial-Mexicali Valleys (IMVs) of California (U.S.A.) and Mexicali (Mexico) are experiencing socioeconomic and environmental changes driven by policy makers and environmental conditions both within and outside the IMVs. The Colorado River Quantification Settlement Agreement (QSA) of 2003 will transfer 30 million acre-feet of Colorado River water from Imperial Valley (IV) agricultural users to Southern California urban users over a 75-year period. Because the water level of the Salton Sea is supported by agricultural runoff, reduced water flows to the sea raise concerns that: 1) air quality will be degraded as dust is generated by the drying Sea-bed, and 2) declining fish populations due to increasing salinity will no longer support birds migrating along a key avian flyway. Rapid population growth in the Mexican border-city of Mexicali, combined with new power plants and plans for water reuse, raises concerns that: 1) the quantity and quality of water supplied to the Salton Sea will decline, and 2) increased vehicle use and electrical power generation will lead to declining air quality in the binational air basin. Each concern may be affected by climate change. As environmental factors change, so too may the agricultural economy of the Imperial Valley that, in turn, depends on the availability of both water and manual labor. The economy of Mexicali is dominated by the maquiladora (manufacturing) industry that depends upon the availability of power, labor and water. A system dynamics model, with annual time step, simulates this complex binational system. The model was developed by an academic team with input from local experts/decision-makers from both Mexico and the US. We are preparing to engage community stakeholders and decision-makers in exploring the model. Insights gained from model results yield better understanding of the consequences of alternative future scenarios that include: QSA water transfers and land fallowing plans

  11. Experience of the chronological correlation of the Holocene sea coastal landforms in the Tuloma River valley and the Kola Bay

    Directory of Open Access Journals (Sweden)

    Tolstobrov D. S.

    2016-03-01

    Full Text Available The paper is a continuation of studies of the Earth's crust neotectonic movements within the north-western part of the Kola region. New radiocarbon data of the lake bottom sediments in the Tuloma River valley allowed to modify diagram of the relative uplift lines of the Earth surface in the north-western part of the Kola region and to compare them with previously constructed epeirogenic spectra of coastal landforms for the study area. The dynamics and nature of the area uplift have been established and the dating of the ancient shorelines within the Tuloma River valley and the Kola Bay of the Barents Sea during the Holocene has been carried out

  12. Modelling of a strong dust event in the complex terrain of the Dead Sea valley during the passage of a gust front

    Directory of Open Access Journals (Sweden)

    Pavel Kishcha

    2016-02-01

    Full Text Available The area of the Dead Sea valley and the adjacent regions are often affected by mineral dust. This study focuses on an extreme dust episode occurring on 22 March 2013, where near-surface dust concentrations of up to 7000 µg m−3 were encountered in the Dead Sea region. This episode is of great interest as it was accompanied by high wind speeds and a gust front that rapidly passed the Judean Mountains. Wind was even accelerated on the lee side of the Judean Mountains leading to a severe downslope wind. We simulated this situation with the comprehensive online-coupled weather forecast model COSMO-ART. Fair agreement was found between the simulated meteorological variables and the observations. The model was capable of producing a reasonable spatiotemporal distribution of near-surface dust concentration, consistent with available measurements in this area. With respect to the time of the maximum near-surface dust concentration in the Dead Sea valley, the model captured it almost perfectly compared to the observed total suspended particle (TSP concentrations. COSMO-ART showed that the high near-surface dust concentration in the Dead Sea valley was mainly determined by local emissions. These emissions were caused by strong winds on the lee side of the Judean Mts. The model showed that an ascending airflow in the Dead Sea valley lifted dust particles, originating mainly from the upwind side of the Judean Mts., up to approximately 7 km. These dust particles contributed to the pronounced maximum in modelled dust aerosol optical depth (AOD over the valley. Here we highlight the important point that the simulated maximum dust AOD was reached in the eastern part of the Dead Sea valley, while the maximum near-surface dust concentration was reached in the western part of the valley.

  13. Trace element and organochlorine contamination in prey and habitat of the Yuma clapper rail in the Imperial Valley, California

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Yuma clapper rail (Rallus longirostris yumanensis) occurs along the Colorado River in Arizona and California, and in small marshes located around the Salton Sea...

  14. Response of the Apodi-Mossoró estuary-incised valley system (NE Brazil to sea-level fluctuations

    Directory of Open Access Journals (Sweden)

    Helenice Vital

    2010-01-01

    Full Text Available This study focuses on the Quaternary sea level changes in the Apodi-Mossoró Estuary and adjacent shelf, Northeastern Brazil, based on the analysis of high-resolution seismic profiles, integrated with echosounder, SRTM and satellite image data. We use these data to develop a relative stratigraphy. An incised-valley extending from the Apodi-Mossoró Estuary onto the shelf dominates the investigated area. In very shallow waters (down to 10 m depth the channel lies mainly in a NW-SE direction, changing to NE-SW in waters below10 m, in the form of a J-shaped valley. The southern flank of the shallow channel presents an abrupt morphology, probably determined by a residual scarp due to neotectonic reactivation of a pre-existing fault. This incised-valley can be correlated with a former river valley formed during the late Pleistocene fall in sea-level. The base-level change related to this drop in sea level can be regionally expressed on seismic lines as a laterally-continuous stratigraphic surface named Horizon I, interpreted as representing the sub-aerial exposure of the continental shelf. Many incised valleys were excavated on this exposed shelf, including that of the Apodi-Mossoró Estuary and its incised valley system. This incised valley has lain buried since the Holocene transgression. The Holocene sediments present sub-horizontal layers, or they have filled the incised valley with oblique features.Este estudo utiliza a integração de dados sísmicos de alta resolução, batimétricos, SRTM e imagens de satélite para desenvolvimento da estratigrafia relativa visando entender as variações do nível do mar durante o Quaternário no estuário do rio Apodi-Mossoró e plataforma adjacente, nordeste do Brasil. A principal feição identificada foi um canal submerso, na plataforma interna, parcialmente preenchido, provavelmente relacionado com o sistema de vales incisos formado durante o rebaixamento do nível do mar no Pleistoceno. O canal

  15. Surface Deformation in Imperial Valley, Southern California

    Science.gov (United States)

    Eneva, M.; Adams, D.; Falorni, G.; Morgan, J.

    2013-12-01

    The Imperial Valley in southern California is subjected to significant tectonic deformation resulting from the relative movement of the North American and Pacific plates. It is characterized by large earthquakes, frequent swarm activity, and aseismic events. High heat flow makes possible the operation of geothermal fields, some of which cause man-made surface displacements superimposed on the tectonic deformation. We apply radar interferometry (InSAR) to analyze Envisat ASAR data for the period 2003-2010. The SqueeSAR technique is used to obtain deformation time series and annual rates at numerous locations of permanent and distributed scatterers (PS and DS). SqueeSAR works very well in agricultural areas, where conventional differential InSAR (DinSAR) fails. We observe differential movements marking the Superstition Hills, San Andreas, and Imperial faults. The Imperial fault traverses agricultural fields, where DInSAR does not work and thus our SqueeSAR observations are the first for this fault (Fig. 1). We also observe steps in the deformation time series around the Superstition Hills fault from an October 2006 aseismic event and the April 2010 M7.2 earthquake south of the U.S.-Mexico border. Significant annual deformation rates are detected in the current geothermal fields. For example, subsidence of up to -50 mm/year is seen at the Salton Sea field (Fig. 2), and both subsidence and uplift are seen at Heber. We also determine the deformation baseline at prospective geothermal fields, thus making it possible in the future to distinguish between man-made and tectonic causes of surface deformation. Fig. 1. Line-of-sight (LOS) deformation indicates differential displacement on both sides of Imperial Fault. Movements away from the satellite are shown in yellow to red, and towards the satellite in blue. Larger deformation is associated with two geothermal fields, Heber (to the south-west) and East Mesa (to the east). Fig. 2. Subsidence in the Salton Sea geothermal

  16. Potential effects of geothermal energy conversion on Imperial Valley ecosystems. [Seven workshop presentations

    Energy Technology Data Exchange (ETDEWEB)

    Shinn, J.H. (ed.)

    1976-12-17

    This workshop on potential effcts of geothermal energy conversion on the ecology of Imperial Valley brought together personnel of Lawrence Livermore Laboratory and many collaborators under the sponsorship of the ERDA Imperial Valley Environmental Project (IVEP). The LLL Integrated Assessment Team identified the electric power potential and its associated effluents, discharges, subsidence, water requirements, land use, and noise. The Working Groups addressed the ecological problems. Water resource management problems include forces on water use, irrigation methods and water use for crops, water production, and water allocation. Agricultural problems are the contamination of edible crops and the reclamation of soil. A strategy is discussed for predevelopment baseline data and for identification of source term tracers. Wildlife resources might be threatened by habitat destruction, powerline impacts, noise and disturbance effects, gas emissions, and secondary impacts such as population pressure. Aquatic ecosystems in both the Salton Sea and fresh waters have potential hazards of salinity and trace metal effects, as well as existing stresses; baseline and bioassay studies are discussed. Problems from air pollution resulting from geothermal resource development might occur, particularly to vegetation and pollinator insects. Conversion of injury data to predicted economic damage isneeded. Finally, Imperial Valley desert ecosystems might be threatened by destruction of habitat and the possible effects on community structure such as those resulting from brine spills.

  17. Geothermal development of the Salton Trough, California and Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, T.D.; Howard, J.H.; Lande, D.P. (eds.)

    1975-04-01

    A geological description is given of the Salton Trought followed by a chronological history of attempts to exploit the area's geothermal resources. In addition, detailed descriptions are given of all ongoing geothermal projects in the area and the organizations conducting them.

  18. Geothermal resources of rifts: A comparison of the rio grande rift and the salton trough

    Science.gov (United States)

    Swanberg, Chandler A.

    1983-05-01

    The Rio Grande Rift and the Salton Trough are the best developed rift systems in the United States and both share many features common to rifts in general, including geothermal resources. These two rifts have different tectonic and magmatic histories, however, and these differences are reflected in the nature of their geothermal resources. The Salton Trough is a well developed and successful rift. It is the landward extension of the Gulf of California spreading center, which has separated Baja, California, from the remainder of Mexico. Quaternary silicic magmatization has occurred and several of the geothermal resources are associated with recent rhyolitic intrusions. Such resources tend to be high temperature (> 200°C). Greenschist facies metamorphism has been observed in several of the geothermal wells. Localized upper crustal melting is a distinct possibility and there is increasing speculation that very high temperature (> 300°C) geothermal fluids may underlie a large portion of the central trough at depths in excess of 4 km. Low temperature geothermal resources associated with shallow hydrothermal convection are less common and tend to be located on the flanks of the trough or in the Coachella Valley to the north of the zone of active rifting. In contrast, the Rio Grande Rift is less well developed. Recent volcanism consists primarily of mantle-derived basalts, which have not had sufficient residence time within the crust to generate significant crustal melting. The geothermal resources within the Rio Grande Rift do not correlate well with these young basalts. Rather, the quantity of geothermal resources are low temperature (resources are less common and the only discovered example is the Valles Caldera of northern New Mexico ( T = 250-300°C). The deep interiors of the sedimentary basins of the Rio Grande Rift do not appear to be major geothermal exploration targets.

  19. NAIP Aerial Imagery (Resampled), Salton Sea - 2005 [ds425

    Data.gov (United States)

    California Department of Resources — NAIP 2005 aerial imagery that has been resampled from 1-meter source resolution to approximately 30-meter resolution. This is a mosaic composed from several NAIP...

  20. CRYPTOMONADS FROM THE SALTON SEA, CALIFORNIA. (R826552)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  1. 75 FR 63502 - Sonny Bono Salton Sea National Wildlife Refuge Complex (Sonny Bono Salton Sea National Wildlife...

    Science.gov (United States)

    2010-10-15

    ... National Wildlife Refuge System, consistent with sound principles of fish and wildlife management... stakeholders and individuals at this time for initial input. If you would like to meet with planning staff or... management propose, for migratory birds,'' and the Lea Act (16 U.S.C. 695), ``for the management and control...

  2. Fluvial terrace formation in the lower Awhea and Pahaoa River valleys, New Zealand: implications for tectonic and sea-level controls

    Science.gov (United States)

    Litchfield, Nicola J.; Clark, Kate J.

    2015-02-01

    Altitudes and ages of fluvial terraces along the lower Awhea and Pahaoa River valleys are compared with the altitudes and ages of Holocene marine deposits and terraces in the actively uplifting southern Hikurangi Margin, New Zealand. From these, we infer fluvial terrace formation processes and examine implications for controls on river behaviour and the likely mechanism of uplift. Both river valleys contain a prominent fill terrace (PgT) radiocarbon dated at 10,000-8000 cal. y BP, which formed in response to the rapid estuary infilling during the late stage of post-glacial sea-level rise. Older and younger terraces are primarily degradation terraces, with the exception of the oldest terraces mapped, which are fill terraces inferred to date from the Last Glacial Coldest Period. These results show the Awhea and Pahaoa Rivers respond to a number of competing controls including climate, tectonics, sea-level and anthropogenic (land use) changes, gradient and valley width. The influence of tectonic uplift can be isolated and Holocene marine terraces, estuarine deposits and the PgT tread altitudes are used to constrain the single-event displacement and slip rate of the submarine Palliser-Kaiwhata Fault, of 2-5 m and 2.5 ± 1 mm/y, respectively. The results also provide insight into likely future response of rivers such as the Awhea and Pahaoa to sea-level rise and tectonic uplift.

  3. Time-transgressive tunnel valley formation indicated by infill sediment structure, North Sea - the role of glaciohydraulic supercooling

    DEFF Research Database (Denmark)

    Kristensen, Thomas Bojer; Piotrowski, Jan; Huuse, Mads

    2008-01-01

    , the volumetrically most important and structurally most distinct, is composed of clinoform reflections downlapping axially up-valley (up-ice), Facies II is composed of near-horizontal, continuous and well layered reflections onlapping the clinoform reflections and the valley walls and Facies III is composed...... of clinoform reflections downlapping axially down-valley (down-ice). A model of formation of this sediment architecture is proposed, in which valley incision and infill are causally linked. It is proposed that Facies I is related to glaciohydraulic supercooling of subglacial meltwater in the distal parts...... of tunnel valleys. The valleys formed time-transgressively during ice retreat, whereby sediment eroded further up-ice was re-deposited along adverse subglacial slopes of the valleys close to the ice margin. The formation of Facies II and III is related to the deposition in proglacial basins during final...

  4. Imperial Valley Environmental Project: progress report

    Energy Technology Data Exchange (ETDEWEB)

    Phelps, P.L.; Anspaugh, L.R. (eds.)

    1977-10-19

    Progress is reported in six areas of research: air quality, water quality, ecosystem quality, subsidence and seismicity, socioeconomic effects, and integrated assessment. A major goal of the air quality element is to evaluate the rate of emission of H/sub 2/S, CO/sub 2/, H/sub 2/, N/sub 2/, CH/sub 4/, and C/sub 2/H/sub 6/ from the operation of the geothermal loop experimental facility at Niland. Concentrations of H/sub 2/S were found to vary between 1500 to 4900 ppM by volume at the Niland facility. To distinguish between geothermal fluids and other waters, extensive sampling networks were established. A major accomplishment was the installation of a high-resolution subsidence-detection network in the Salton Sea geothermal field area, centered on the test facility at Niland. A major effort went into establishing a background of data needed for subsequent impact assessments related to socioeconomic issues raised by geothermal developments. Underway are a set of geothermal energy scenarios that include power development schedules, technology characterizations, and considerations of power-plant-siting criteria. A Gaussian air-pollution model was modified for use in preliminary air-quality assessments. A crop-growth model was developed to evaluate impacts of gases released from geothermal operations on various agricultural crops. Work is also reported on the legal analysis of geothermal legislation and the legal aspects of water-supply utilization. Remote sensing was directed primarily at the Salton Sea, Heber, Brawley, and East Mesa KGRAs. However, large-format photography of the entire Salton Trough was completed. Thermal and multispectral imaging was done for several selected sites in the Salton Sea KGRA. (JGB)

  5. Shallow hydrothermal regime of the East Brawley and Glamis known geothermal resource areas, Salton Trough, California

    Energy Technology Data Exchange (ETDEWEB)

    Mase, C.W.; Sass, J.H.; Brook, C.A.; Munroe, R.J.

    1981-01-01

    Thermal gradients and thermal conductivities were obtained in real time using an in situ heat-flow technique in 15 shallow (90 to 150 m) wells drilled between Brawley and Glamis in the Imperial Valley, Southern California. The in situ measurements were supplemented by follow-up conventional temperature logs in seven of the wells and by laboratory measurements of thermal conductivity on drill cuttings. The deltaic sedimentary material comprising the upper approx. 100 m of the Salton Trough generally is poorly sorted and high in quartz resulting in quite high thermal conductivities (averaging 2.0 Wm/sup -1/ K/sup -1/ as opposed to 1.2 to 1.7 for typical alluvium). A broad heat-flow anomaly with maximum of about 200 mWm/sup -2/ (approx. 5 HFU) is centered between Glamis and East Brawley and is superimposed on a regional heat-flow high in excess of 100 mWm/sup -2/ (> 2.5 HFU). The heat-flow high corresponds with a gravity maximum and partially with a minimum in electrical resistivity, suggesting the presence of a hydrothermal system at depth in this area.

  6. Earthquake-induced barium anomalies in the Lisan Formation, Dead Sea Rift valley, Israel

    Science.gov (United States)

    Katz, Amitai; Agnon, Amotz; Marco, Shmuel

    2009-08-01

    Prominent barium concentration anomalies that appear within earthquake brecciated layers (seismites) in the late Pleistocene lacustrine Lisan Formation in the Dead Sea Basin (DSB) are described and discussed here for the first time. Chemical analyses of samples from vertical profiles through the seismites display asymmetric Ba concentration peaks. The peaks start a few centimeters above the seismite's base and gradually rise to maxima reaching some 1000 ppm Ba, before falling off to background values (around 100 ppm), or abutting against the upper boundary of the breccia layer. High resolution SEM and electron microprobe analyses disclose that the Ba in the anomalies resides within prismatic crystallites (mostly sorting relationship with the latter. The peaks of the anomalies reflect higher population density, rather than larger crystal sizes, of the BM crystallites therein. Mass balance calculations show that the mass of Ba 2+ dissolved in the lake above a unit area of the seismites was mostly several times larger than that found in the seismite. The concentration of Ba 2+ in DSB Ca-chloride brines is mostly lesser than that in the DSB Lake, ruling out the former as a source of Ba to the anomalies. We propose that, during earthquakes, the uppermost bottom sediment layers in the DSB Lake were shaken and re-suspended into the overlying brine. The larger, faster-settling fragments and grains remained almost intact or were rapidly removed, unaffected, from the slurry. However, the finer grains remained in suspension for longer periods, allowing nucleation and growth of BM crystallites on their surfaces from the surrounding brine before reaching the bottom. The lag of Ba trapping behind the breccia accumulation and the asymmetrical peak shapes of the anomalies are accounted for by decreasing dilution of the Ba-rich finer particles by Ba-poor coarse grains during seismite accumulation, as reflected by the graded bedding of the seismite layers. The supply rate of Ba 2

  7. Delineation of tunnel valley across the North Sea coastline, Denmark based on reflection seismic data, boreholes, TEM and Schlumberger soundings

    DEFF Research Database (Denmark)

    Andersen, Theis Raaschou; Jørgensen, Flemming; Christensen, Steen

    of on- and offshore 2D seismic data, TEM (Transient Electro-Magnetic) soundings, Schlumberger soundings, and boreholes. The valleys are observed as discrete incisions with three overall orientations: SSE – NNW, ESE – WNW, and SSW – NNE. They have depths between 75 and 185 m, widths up to 1.8 km......, and lengths from 7 to 25 km. The infill comprises till, glaciofluvial sand, and glaciolacustrine clay and silt. Younger tunnel valleys are found to often re-use pre-established valleys generating cut-and-fill structures which are clearly revealed on the reflection seismic profiles. Cross-cutting relations...

  8. Delineation of tunnel valleys across the North Sea coastline, Denmark based on reflection seismic data, boreholes, TEM and Schlumberger soundings

    DEFF Research Database (Denmark)

    Andersen, Theis Raaschou; Jørdensen, Flemming; Christensen, Steen

    of on- and offshore 2D seismic data, TEM (Transient Electro-Magnetic) soundings, Schlumberger soundings, and boreholes. The valleys are observed as discrete incisions with three overall orientations: SSE – NNW, ESE – WNW, and SSW – NNE. They have depths between 75 and 185 m, widths up to 1.8 km......, and lengths from 7 to 25 km. The infill comprises till, glaciofluvial sand, and glaciolacustrine clay and silt. Younger tunnel valleys are found to often re-use pre-established valleys generating cut-and-fill structures which are clearly revealed on the reflection seismic profiles. Cross-cutting relations...

  9. Geometry of the Paleo-Nueces River Incised-Valley, Corpus Christi Bay, Texas as it Relates to Quaternary Sea Level History

    Science.gov (United States)

    Lugrin, L.; Gulick, S. S.; Goff, J. A.

    2012-12-01

    CHIRP subbottom seismic data were collected on the 2009 and 2011 Marine Geophysics Field courses at the University of Texas at Austin within the Corpus Christi Bay along the central Texas coast in order to study the geometry of the ancestral Nueces River incised valley and its evolution over Quaternary sea level history. Since the late Pleistocene, the Nueces River valley experienced a gradual infill due to sea level rise, interrupted by two major flooding events that represent periods of rapid sediment influx. These flooding events are recognizable based on abrupt changes in seismic facies. Discontinuous, chaotic fluvial lag deposits present underneath a fairly continuous, stratified, sub-horizontal estuarine coastal plain facies mark what is interpreted to be the Pleistocene/Holocene unconformity. Above the P/H boundary, oyster reefs thrive within the estuary until capped by a strong reflector, marking the second flooding surface that allowed enough incoming sediment to discontinue oyster reef growth. The estuarine deposits within the paleo-Nueces river valley exhibit a landward migration as the Holocene transgression proceeded. As infill continued, the bay-head delta prograded seaward and the flood-tidal delta extended progressively further up the estuary until the central estuarine basin was capped. The earlier flooding events provide strong reflectors that can be linked to the draining of Lake Agassiz around 8.2 k.a.. This event flooded the Gulf of Mexico with freshwater, and interrupted the estuarine infilling of the Nueces paleo-channel. Cores from previous studies have found at least two species of oyster reefs in Corpus Christi Bay: euryhaline species Crassostrea virginica, and Ostrea equestris, a species known to thrive in higher salinity waters. The presence of both species at the flooding boundary suggests the sudden pulse of freshwater mixed with higher salinity oceanic water. The second flooding surface is interpreted to be associated with an increase

  10. GeoTIFF image of the backscatter intensity of the sea floor of the Hudson Shelf Valley (12-m resolution, Mercator, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Hudson Shelf Valley is the submerged seaward extension of the ancestral Hudson River drainage system and is the largest physiographic feature on the Middle...

  11. GeoTIFF image of shaded-relief bathymetry, colored by backscatter intensity, of the sea floor of the Hudson Shelf Valley (12-m resolution, Mercator, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Hudson Shelf Valley is the submerged seaward extension of the ancestral Hudson River drainage system and is the largest physiographic feature on the Middle...

  12. Valley fever

    Science.gov (United States)

    ... especially the first trimester) People of Native American, African, or Philippine descent may also get more severe ... that causes Valley fever) Chest x-ray Sputum culture Sputum smear (KOH test) Tests done for more ...

  13. Valley Fever

    Science.gov (United States)

    ... loss Headache Valley fever Symptoms & causes Diagnosis & treatment Advertisement Mayo Clinic does not endorse companies or products. ... a Job Site Map About This Site Twitter Facebook Google YouTube Pinterest Mayo Clinic is a not- ...

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

    Science.gov (United States)

    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

  15. Qena Valley Evolution, Eastern Desert, Egypt

    Science.gov (United States)

    Abdelkareem, Mohamed

    2010-05-01

    Remotely sensed topographic and optical data were used to identify tectonic phenomena in Qena Valley. Using digital elevation model, morphotectonic features were identified. Processing and analysis were carried out by the combined use of: (1) digital elevation model, (2) digital drainage network analysis, (3) optical data analysis, and (4) lineament extraction and analysis. Structural information from other sources, such as geological maps, remotely sensed images and field observations were analyzed with geographic information system techniques. The analysis results reveal that the linear features of Qena Valley controlled by several structural elements have different trends NW-SE, NE-SW and N-S trends. Basement rocks at Qena valley has a major NE-SW trending and the sedimentary rocks are dominated by a NW-SE, NE-SW and N-S trends while, E-W are less abundant. The NE-SW trends at north Eastern Desert Egypt attain to normal faults that reflect extension in NW-SE direction, which is related to strike slip faulting along NW-SE directed Najd fault system. Further, the NE-SW is abundant as joints and fractures seem to have controlled the path of the Nile in Qift - Qena area. The NW-SE direction are abundant in the rock fracture trends (Gulf of Suez or Red Sea) and reflects Neoproterozoic faults have been reactivated in Neogene during rifting events of the Red Sea opening and marked the sedimentary rocks at Qena valley. The results of the lineament density map reveals that Qena valley was originated along one fault that trend like the Gulf of Suez and the range of the Red Sea Hills. This major fault was dissected by several lateral faults are seen well exposed at numerous places within the valley, especially on its eastern side. Both sides of Qena valley have a similar density matching may attain to that this lineaments affected Qena valley during rifting. This rifts it probably happened in Early Miocene associated with Red Sea tectonics. The general southward slope of

  16. Organochlorines and selenium in fishes and colonial waterbirds from the Salton Sea

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — As part of the continuing U.S. Department of the Interior Drainwater Investigation, a monitoring program has been proposed to determine current and future effects of...

  17. Early Pliocene Hiatus in Sand Output by the Colorado River: Evidence From Marine Deposits in the Salton Trough, Southern California

    Science.gov (United States)

    Dorsey, R. J.; Bykerk-Kauffman, A.

    2015-12-01

    Early Pliocene deposits in the western Salton Trough preserve a high-fidelity record of sediment dispersal into the marine realm during initiation and early evolution of the Colorado River (CR). Grain-size fractionation, sediment routing, and transport dynamics of the early CR delta are recorded in sediments of the Fish Creek - Vallecito basin, which was located ~100 km south of Yuma along the transform plate boundary at 5 Ma. Early Pliocene delivery of CR sand to the basin took place in two distinct pulses: (1) deposition of sandy turbidites (Wind Caves Mbr of the Latrania Fm) in a restricted submarine canyon at Split Mt Gorge between ~5.3 and 5.1 Ma; and (2) progradation of a thick, widespread, coarsening-up deltaic sequence of marine mudstone, sandstone, and coquinas (Deguynos Fm) between ~4.8 and 4.2 Ma. Estimated flux of CR sediment during Wind Caves deposition was weak (~3-5 Mt/yr) compared to the long-term average (172±64 Mt/yr). The two pulses of CR sand input are separated by the Coyote Clay (CC, ~5.1-4.8 Ma), a regionally correlable, greenish-yellow-weathering marine claystone unit at the base of the Deguynos Fm. CC gradationally overlies Wind Caves turbidites in the area of the paleocanyon. In contrast, in the Coyote Mts 15-23 km to the south and SE, CC rests on coarse-grained locally-derived late Miocene sedimentary rocks, Alverson volcanics, and metamorphic basement rock along a regional unconformity. Identical claystone facies occur in the NW Indio Hills (restores to Yuma at the mouth of the CR at 5 Ma), and Sierra Cucapa in Mexico (~200 km south of Yuma at 5 Ma). Marine localities outside of the Wind Caves paleocanyon experienced slow to negligible sedimentation along a rugged rocky shoreline until abrupt arrival of CR-derived clay. CC accumulated in a sand-starved, pro-delta marine setting (Winker, 1987) over an inferred N-S distance of ~200 km. We therefore reject an alternate hypothesis that CC accumulated on the muddy slope of the prograding CR

  18. Ambient Noise Tomography of Southern California Images Dipping San Andreas-Parallel Structure and Low-Velocity Salton Trough Mantle

    Science.gov (United States)

    Barak, S.; Klemperer, S. L.; Lawrence, J. F.

    2014-12-01

    Ambient noise tomography (ANT) images the entire crust but does not depend on the spatial and temporal distribution of events. Our ANT high-resolution 3D velocity model of southern California uses 849 broadband stations, vastly more than previous studies, and four years of data, 1997-1998, 2007, and 2011, chosen to include our own broadband Salton Seismic Imaging Project, a 40-station transect across the Salton Trough, as well as other campaign stations in both Mexico and the U.S.A., and permanent stations. Our shear-wave model has 0.05° x 0.05° lateral and 1 km vertical blocks. We used the Harvard Community Velocity Model (CVM-H) as the initial model for the inversion. We show significant differences relative to the CVM-H model, especially in the lower crust and upper mantle. We observe prominent low-velocity anomalies in the upper mantle under the Salton Buttes and Cerro Prieto geothermal fields, indicating high-temperatures and possibly partial-melt. Similar low-velocity zones have been previously observed along the Gulf of California. We also observe vertical to gradually dipping lateral velocity contrasts in the lower crust under the southern part of the San Andreas Fault. The east to northeast dip may represent crustal fabric sheared by movement of the Pacific plate under the North American plate prior to the initiation of transform motion.

  19. Evolution of Rotations in the Fish Creek Vallecito Basin, Western Salton Trough, CA

    Science.gov (United States)

    Housen, B. A.; Dorsey, R. J.; Janecke, S. U.; Axen, G. J.

    2006-12-01

    Rocks in the Western Salton Trough region record the history of slip on the transtensional West Salton detachment fault and initiation of younger strike-slip faults in this plate boundary zone. Spatial and temporal patterns of vertical axis rotations as determined by paleomagnetism can be used to provide valuable constraints on the structural-tectonic evolution of this area. Prior work includes the magnetostratigraphy of Plio-Pleistocene sedimentary rocks in the Fish Creek-Vallecito Basin (FCVB) (Opdyke et al., 1977; Johnson et al., 1983), who found that these rocks contain a complete record of geomagnetic field reversals spanning Pliocene-Pleistocene time. Johnson et al. (1983) also concluded that the FCVB had undergone 35° of CW rotation during the past 0.9 Ma. We resampled and reanalyzed their section, and sampled additional sedimentary and plutonic rocks in the Western Salton Trough in order to better document the history of vertical axis rotation recorded by these rocks. Results from 29 sites in the FCVB have well-defined magnetizations with two components. The first removed component in all samples is unblocked between 90 and 220 °C, and the second-removed components are unblocked between 300 and 590 °C. The second-removed components have either normal or reversed polarity. Sites from the Diablo Fm are predominantly reversed and have a mean of D = 204, I = -48.3, k = 37, α95 = 12.7°, N = 5. Sites from the middle of the section (Olla and Tapiado Fms) are predominantly normal and have a mean of D = 8.1, I = 48, k = 32, α95= 8.7°, N = 10. Sites from the upper portion of the section (Hueso Fm) have predominantly reversed polarity with means of D = 179.6, I = -43.4, k = 82, α95 = 10.2°, N = 4. Results from weakly-magnetized and deformed rocks of the La Posta pluton, on the south side of Whale Peak, have well-defined magnetizations with a group mean direction of D = 16.3, I = 37.3, k = 44, α95 = 7.4°, N = 10. The stratigraphic distribution of declination

  20. Valley evolution by meandering rivers

    Science.gov (United States)

    Limaye, Ajay Brian Sanjay

    Fluvial systems form landscapes and sedimentary deposits with a rich hierarchy of structures that extend from grain- to valley scale. Large-scale pattern formation in fluvial systems is commonly attributed to forcing by external factors, including climate change, tectonic uplift, and sea-level change. Yet over geologic timescales, rivers may also develop large-scale erosional and depositional patterns that do not bear on environmental history. This dissertation uses a combination of numerical modeling and topographic analysis to identify and quantify patterns in river valleys that form as a consequence of river meandering alone, under constant external forcing. Chapter 2 identifies a numerical artifact in existing, grid-based models that represent the co-evolution of river channel migration and bank strength over geologic timescales. A new, vector-based technique for bank-material tracking is shown to improve predictions for the evolution of meander belts, floodplains, sedimentary deposits formed by aggrading channels, and bedrock river valleys, particularly when spatial contrasts in bank strength are strong. Chapters 3 and 4 apply this numerical technique to establishing valley topography formed by a vertically incising, meandering river subject to constant external forcing---which should serve as the null hypothesis for valley evolution. In Chapter 3, this scenario is shown to explain a variety of common bedrock river valley types and smaller-scale features within them---including entrenched channels, long-wavelength, arcuate scars in valley walls, and bedrock-cored river terraces. Chapter 4 describes the age and geometric statistics of river terraces formed by meandering with constant external forcing, and compares them to terraces in natural river valleys. The frequency of intrinsic terrace formation by meandering is shown to reflect a characteristic relief-generation timescale, and terrace length is identified as a key criterion for distinguishing these

  1. Energy valley in transition

    NARCIS (Netherlands)

    Verwayen, Barbara

    2006-01-01

    The Energy Valley foundation was born in 2004. It functions as a catalyst and platform for private and public organisations. It has a supporting and facilitating role in realising projects on energy conservation and sustainable energy. The Energy Valley a

  2. Silicon Valley: Planet Startup

    NARCIS (Netherlands)

    Dr. P. Ester; dr. A. Maas

    2016-01-01

    For decades now, Silicon Valley has been the home of the future. It's the birthplace of the world's most successful high-tech companies-including Apple, Yahoo, Google, Facebook, Twitter, and many more. So what's the secret? What is it about Silicon Valley that fosters entrepreneurship and

  3. Haemoragisk Rift Valley Fever

    DEFF Research Database (Denmark)

    Fabiansen, Christian; Thybo, Søren

    2007-01-01

    A case of fatal hemorrhagic Rift Valley fever during an epidemic in Kenya's North Eastern Province in January 2007 is described.......A case of fatal hemorrhagic Rift Valley fever during an epidemic in Kenya's North Eastern Province in January 2007 is described....

  4. Infill of tunnel valleys associated with landward‐flowing ice sheets

    DEFF Research Database (Denmark)

    Moreau, Julien; Huuse, Mads

    2014-01-01

    The southern termination of the Middle and Late Pleistocene Scandinavian ice sheets was repeatedly located in the southern North Sea (sNS) and adjacent, north-sloping land areas. Giant meltwater-excavated valleys (tunnel valleys) formed at the southern termination of the ice sheets and contain...

  5. Geometry of Valley Growth

    CERN Document Server

    Petroff, Alexander P; Abrams, Daniel M; Lobkovsky, Alexander E; Kudrolli, Arshad; Rothman, Daniel H

    2011-01-01

    Although amphitheater-shaped valley heads can be cut by groundwater flows emerging from springs, recent geological evidence suggests that other processes may also produce similar features, thus confounding the interpretations of such valley heads on Earth and Mars. To better understand the origin of this topographic form we combine field observations, laboratory experiments, analysis of a high-resolution topographic map, and mathematical theory to quantitatively characterize a class of physical phenomena that produce amphitheater-shaped heads. The resulting geometric growth equation accurately predicts the shape of decimeter-wide channels in laboratory experiments, 100-meter wide valleys in Florida and Idaho, and kilometer wide valleys on Mars. We find that whenever the processes shaping a landscape favor the growth of sharply protruding features, channels develop amphitheater-shaped heads with an aspect ratio of pi.

  6. Intermontane valley fills

    OpenAIRE

    Mey, Jürgen (Diplom-Geologe)

    2017-01-01

    Sedimentary valley fills are a widespread characteristic of mountain belts around the world. They transiently store material over time spans ranging from thousands to millions of years and therefore play an important role in modulating the sediment flux from the orogen to the foreland and to oceanic depocenters. In most cases, their formation can be attributed to specific fluvial conditions, which are closely related to climatic and tectonic processes. Hence, valley-fill deposits constitute v...

  7. Boyne Valley Tombs

    Science.gov (United States)

    Prendergast, Frank

    The passage tombs of the Boyne Valley exhibit the greatest level of development of the megalithic tomb building tradition in Ireland in terms of their morphology, embellishment, burial tradition, grave goods, clustering, and landscape siting. This section examines these characteristics and gives a summary archaeoastronomical appraisal of their orientation and detected astronomical alignment.

  8. Breathing Valley Fever

    Centers for Disease Control (CDC) Podcasts

    2014-02-04

    Dr. Duc Vugia, chief of the Infectious Diseases Branch in the California Department of Public Health, discusses Valley Fever.  Created: 2/4/2014 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 2/5/2014.

  9. Bringing Silicon Valley inside.

    Science.gov (United States)

    Hamel, G

    1999-01-01

    In 1998, Silicon Valley companies produced 41 IPOs, which by January 1999 had a combined market capitalization of $27 billion--that works out to $54,000 in new wealth creation per worker in a single year. Multiply the number of employees in your company by $54,000. Did your business create that much new wealth last year? Half that amount? It's not a group of geniuses generating such riches. It's a business model. In Silicon Valley, ideas, capital, and talent circulate freely, gathering into whatever combinations are most likely to generate innovation and wealth. Unlike most traditional companies, which spend their energy in resource allocation--a system designed to avoid failure--the Valley operates through resource attraction--a system that nurtures innovation. In a traditional company, people with innovative ideas must go hat in hand to the guardians of the old ideas for funding and for staff. But in Silicon Valley, a slew of venture capitalists vie to attract the best new ideas, infusing relatively small amounts of capital into a portfolio of ventures. And talent is free to go to the companies offering the most exhilarating work and the greatest potential rewards. It should actually be easier for large, traditional companies to set up similar markets for capital, ideas, and talent internally. After all, big companies often already have extensive capital, marketing, and distribution resources, and a first crack at the talent in their own ranks. And some of them are doing it. The choice is yours--you can do your best to make sure you never put a dollar of capital at risk, or you can tap into the kind of wealth that's being created every day in Silicon Valley.

  10. Green valley galaxies

    Directory of Open Access Journals (Sweden)

    Salim S.

    2014-01-01

    Full Text Available The “green valley” is a wide region separating the blue and the red peaks in the ultraviolet-optical color magnitude diagram, first revealed using GALEX UV photometry. The term was coined by Christopher Martin (Caltech, in 2005. Green valley highlights the discriminating power of UV to very low relative levels of ongoing star formation, to which the optical colors, including u−r, are insensitive. It corresponds to massive galaxies below the star-forming, “main” sequence, and therefore represents a critical tool for the study of the quenching of star formation and its possible resurgence in otherwise quiescent galaxies. This article reviews the results pertaining to (predominantly disk morphology, structure, environment, dust content and gas properties of green valley galaxies in the local universe. Their relationship to AGN is also discussed. Attention is given to biases emerging from defining the “green valley” using optical colors. We review various evolutionary scenarios and we present evidence for a new one, the quasi-static view of the green valley, in which the majority (but not all of galaxies currently in the green valley were only partially quenched in the distant past and now participate in a slow cosmic decline of star formation, which also drives down the activity on the main sequence, presumably as a result of the dwindling accretion/cooling onto galaxy disks. This emerging synthetic picture is based on the findings from Fang et al. (2012, Salim et al. (2012 and Martin et al. (2007, as well as other results.

  11. Near-surface groundwater responses to injection of geothermal wastes

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, S.C.

    1984-06-01

    This report assesses the feasibility of injection as an alternative for geothermal wastewater disposal and analyzes hydrologic controls governing the upward migration of injected fluids. Injection experiences at several geothermal developments are presented including the following: Raft River Valley, Salton Sea, East Mesa, Otake, Hatchobaru, and Ahuachapan geothermal fields.

  12. Fluvial valleys and Martian palaeoclimates

    Science.gov (United States)

    Gulick, Virginia C.; Baker, Victor R.

    1989-10-01

    Theoretical models of early Martian atmospheric evolution describe the maintenance of a dense CO2 atmosphere and a warm, wet climate until the end of the heavy-bombardment phase of impacting. However, the presence of very young, earthlike fluvial valleys on the northern flank of Alba Patera conflicts with this scenario. Whereas the widespread ancient Martian valleys generally have morphologies indicative of sapping erosion by the slow outflow of subsurface water, the local Alba valleys were probably formed by surface-runoff processes. Because subsurface water flow might be maintained by hydrothermal energy inputs and because surface-runoff valleys developed late in Martian history, it is not necessary to invoke drastically different planet-wide climatic conditions to explain valley development on Mars. The Alba fluvial valleys can be explained by hydrothermal activity or outflow-channel discharges that locally modified the atmosphere, including precipitation and local overland flow on low-permeability volcanic ash.

  13. Imperial County geothermal development semi-annual report, October 1, 1980-March 31, 1981

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    The current geothermal progress in Imperial County is reported. Three areas are reported: Geothermal Administration, Geothermal Planning, and other Geothermal Activities. Geothermal Administration addresses the status of the Imperial Valley Environmental Project (IVEP) transfer, update of the Geothermal Resource Center, and findings of Geothermal field inspections. In addition, the cooperative efforts between industry and the County; Master EIR for the Salton Sea KGRA and the resurveying of the subsidence detection network are covered. Geothermal Planning addresses a Board of Supervisor action on the Union Oil Geothermal Production Permit for 16 wells in the Salton Sea KGRA and a permit for Southern California Edison 10 megawatts power plant in the Salton Sea KGRA. Planning Commission action covers: Amendment of Magma Power's 49 megawatts Geothermal Production Permit to 28 megawatt power plant and relocation of the plant and wells within the Salton Sea KGRA; Exploration permit to Occidental Geothermal for four exploratory wells in East Brawley; Geothermal Production Permit to Southern California Edison to operate a 10 megawatt power plant in the Salton Sea KGRA; and Geothermal production permit to Union Oil for 16 production-injection wells in the Salton Sea KGRA. Lastly, EIR exemptions to CEQA were granted to Chevron for 70 shallow temperature observation holes and Union for fifteen. Other Geothermal Activity addresses the County Direct Heat Development study; the solicitation for district heating and cooling proposals; the new Geothermal Class II-1 disposal site; the DOE Region IX meeting in Tucson; and USGA designating a new KGRA, the East Brawley KGRA, the Westmorland KGRA, and revising the southern border of the Salton Sea KGRA.

  14. Commercial production of ethanol in the San Luis Valley, Colorado. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Hewlett, E.M.; Erickson, M.V.; Ferguson, C.D.; Sherwood, P.B.; Boswell, B.S.; Walter, K.M.; Hart, M.L.

    1983-07-01

    The purpose of this study is to assess the commercial feasibility of producing between 76 and 189 million liters (20 and 50 million gallons) of ethanol annually in the San Luis Valley, Colorado using geothermal energy as the primary heat source. The San Luis Valley is located in south-central Colorado. The valley is a high basin situated approximately 2316 meters (7600 feet) above sea level which contains numerous warm water wells and springs. A known geothermal resource area (KGRA) is located in the east-central area of the valley. The main industry in the valley is agriculture, while the main industry in the surrounding mountains is lumber. Both of these industries can provide feedstock for the production of ethanol.

  15. Commercial production of ethanol in the San Luis Valley, Colorado. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hewlett, E.M.; Erickson, M.V.; Ferguson, C.D.; Boswell, B.S.; Walter, K.M.; Hart, M.L.; Sherwood, P.B.

    1983-07-01

    The commercial feasibility of producing between 76 and 189 million liters (20 to 50 million gallons) of ethanol annually in the San Luis Valley, Colorado using geothermal energy as the primary heat source was assessed. The San Luis Valley is located in south-central Colorado. The valley is a high basin situated approximately 2316 meters (7600 feet) above sea level which contains numerous warm water wells and springs. A known geothermal resource area (IGRA) is located in the east-central area of the valley. The main industry in the valley is agriculture, while the main industry in the surrounding mountains is lumber. Both of these industries can provide feedstocks for the production of ethanol.

  16. Optical manipulation of valley pseudospin

    Science.gov (United States)

    Ye, Ziliang; Sun, Dezheng; Heinz, Tony F.

    2017-01-01

    The coherent manipulation of spin and pseudospin underlies existing and emerging quantum technologies, including quantum communication and quantum computation. Valley polarization, associated with the occupancy of degenerate, but quantum mechanically distinct valleys in momentum space, closely resembles spin polarization and has been proposed as a pseudospin carrier for the future quantum electronics. Valley exciton polarization has been created in the transition metal dichalcogenide monolayers using excitation by circularly polarized light and has been detected both optically and electrically. In addition, the existence of coherence in the valley pseudospin has been identified experimentally. The manipulation of such valley coherence has, however, remained out of reach. Here we demonstrate all-optical control of the valley coherence by means of the pseudomagnetic field associated with the optical Stark effect. Using below-bandgap circularly polarized light, we rotate the valley exciton pseudospin in monolayer WSe2 on the femtosecond timescale. Both the direction and speed of the rotation can be manipulated optically by tuning the dynamic phase of excitons in opposite valleys. This study unveils the possibility of generation, manipulation, and detection of the valley pseudospin by coupling to photons.

  17. Distribution of glacial deposits, soils, and permafrost in Taylor Valley, Antarctica

    Science.gov (United States)

    Bockheim, James G.; Prentice, M.L.; McLeod, M.

    2008-01-01

    We provide a map of lower and central Taylor Valley, Antarctica, that shows deposits from Taylor Glacier, local alpine glaciers, and grounded ice in the Ross Embayment. From our electronic database, which includes 153 sites from the coast 50 km upvalley to Pearse Valley, we show the distribution of permafrost type and soil subgroups according to Soil Taxonomy. Soils in eastern Taylor Valley are of late Pleistocene age, cryoturbated due to the presence of ground ice or ice-cemented permafrost within 70 cm of the surface, and classified as Glacic and Typic Haploturbels. In central Taylor Valley, soils are dominantly Typic Anhyorthels of mid-Pleistocene age that have dry-frozen permafrost within the upper 70 cm. Salt-enriched soils (Salic Anhyorthels and Petrosalic Anhyorthels) are of limited extent in Taylor Valley and occur primarily on drifts of early Pleistocene and Pliocene age. Soils are less developed in Taylor Valley than in nearby Wright Valley, because of lesser salt input from atmospheric deposition and salt weathering. Ice-cemented permafrost is ubiquitous on Ross Sea, pre-Ross Sea, and Bonney drifts that occur within 28 km of the McMurdo coast. In contrast, dry-frozen permafrost is prevalent on older (???115 ky) surfaces to the west. ?? 2008 Regents of the University of Colorado.

  18. Lithospheric Structure and Active Deformation in the Salton Trough from Coseismic and Postseismic Models of the 2010 Mw 7.2 El Mayor-Cucapah Earthquake

    Science.gov (United States)

    Fielding, E. J.; Huang, M. H.; Dickinson, H.; Freed, A. M.; Burgmann, R.; Gonzalez-Ortega, J. A.; Andronicos, C.

    2016-12-01

    The 4 April 2010 Mw 7.2 El Mayor-Cucapah (EMC) Earthquake ruptured about 120 km along several NW-striking faults to the west of the Cerro Prieto Fault in the Salton Trough of Baja California, Mexico. We analyzed interferometric synthetic aperture radar (SAR), SAR and optical pixel offsets, and continuous and campaign GPS data to optimize an EMC coseismic rupture model with 9 fault segments, which fits the complex structure of the faults. Coseismic slip inversion with a layered elastic model shows that largely right-lateral slip is confined to upper 10 km with strong variations along strike. Near-field GPS measures slip on a north-striking normal fault that ruptured at the beginning of the earthquake, previously inferred from seismic waveforms. EMC Earthquake postseismic deformation shows the Earth's response to the large coseismic stress changes. InSAR shows rapid shallow afterslip at the north and south ends of the main ruptures. Continuous GPS from the Plate Boundary Observatory operated by UNAVCO measures the first six years of postseismic deformation, extremely rapid near the rupture. Afterslip on faults beneath the coseismic rupture cannot explain far-field displacements that are best explained by viscoelastic relaxation of the lower crust and upper mantle. We built a viscoelastic 3D finite element model of the lithosphere and asthenosphere based on available data for the region with the EMC coseismic faults embedded inside. Coseismic slip was imposed on the model, allowed to relax for 5 years, and then compared to the observed surface deformation. Systematic exploration of the viscoelastic parameters shows that horizontal and vertical heterogeneity is required to fit the postseismic deformation. Our preferred viscoelastic model has weaker viscosity layers beneath the Salton Trough than adjacent blocks that are consistent with the inferred differences in the geotherms. Defining mechanical lithosphere as rocks that have viscosities greater than 10^19 Pa s (able

  19. Crustal Recycling by Surface Processes Along the Pacific-North America Plate Boundary: From the Colorado Plateau to the Salton Trough and Gulf of California

    Science.gov (United States)

    Dorsey, R. J.

    2009-12-01

    Delivery of sediment from the Colorado Plateau to basins in the Salton Trough and northern Gulf of California exerts an incompletely understood control on structure, magmatism, rheology, and rift evolution. This study examines the volumetric rate at which crust of the continent interior is moved as sediment and converted into new crust in deep sedimentary basins along the active oblique-divergent plate boundary. The modern Colorado River was integrated by a series of lake spillover events that propagated from Lake Mead to the Salton Trough between 6.0 and 5.3 Ma (Spencer et al., 2001, 2008; House et al., 2005; Dorsey et al., 2007). Thus all transfer of sediment from the Colorado Plateau to the Salton Trough and northern Gulf post-dates 5.3 Ma. The volume of Colorado River sediment in subsurface basins of the Salton Trough and northern Gulf of California is estimated using published geophysical and borehole data, and two end-member crustal models. In the first model, pre-existing granitic crust has been fully ruptured by oblique rifting, and new crust is being formed by input of sediment from above mixed with mafic intrusions from below (Fuis et al., 1984). In the second model, the middle and lower crust consists of thinned granitic rock that has undergone large-scale crustal flow (Gonzalez et al., 2005). Using the two crustal models for basin depth, and measured basin areas, the total volume of Colorado River sediment in subsurface basins is bracketed between 198,000 and 291,000 km3. The volume of rock eroded from the Colorado Plateau can be approximated by multiplying the pre-dam sediment discharge (1.2-1.5 x 108 t/yr; Meade and Parker, 1985) by the total lifetime of sediment output (5.3 m.y.) and converting mass to volume by bracketing average sediment density between 2300 and 2500 kg/m3. This yields an equivalent sediment volume of 200,000-270,000 km3 that would have been delivered to the plate boundary at early-1900's discharge rates. Thus, despite current

  20. Structure Contour of the Top of the Cotton Valley Group, Western Gulf and East Texas Basin and Louisiana-Mississippi Salt Basins Provinces (047, 048 and 049)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map shows the structural configuration on the top of the Cotton Valley Group in feet below sea level. The map was produced by calculating the difference between...

  1. Dark Valley in Newton Crater

    Science.gov (United States)

    2003-01-01

    MGS MOC Release No. MOC2-418, 11 July 2003This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) high resolution image shows part of a dark-floored valley system in northern Newton Crater. The valley might have been originally formed by liquid water; the dark material is probably sand that has blown into the valley in more recent times. The picture was acquired earlier this week on July 6, 2003, and is located near 39.2oS, 157.9oW. The picture covers an area 2.3 km (1.4 mi) across; sunlight illuminates the scene from the upper left.

  2. Assessing long-term postseismic deformation following the M7.2 4 April 2010, El Mayor-Cucapah earthquake with implications for lithospheric rheology in the Salton Trough

    Science.gov (United States)

    Spinler, Joshua C.; Bennett, Richard A.; Walls, Chris; Lawrence, Shawn; González García, J. Javier

    2015-05-01

    The 4 April 2010 Mw 7.2 El Mayor-Cucapah (EMC) earthquake provides the best opportunity to date to study the lithospheric response to a large (>M6) magnitude earthquake in the Salton Trough region through analysis of Global Positioning System (GPS) data. In conjunction with the EarthScope Plate Boundary Observatory (PBO), we installed six new continuous GPS stations in the months following the EMC earthquake to increase station coverage in the epicentral region of northern Baja California, Mexico. We modeled the pre-EMC deformation field using available campaign and continuous GPS data for southern California and northern Baja California and inferred a pre-EMC secular rate at each new station location. Through direct comparison of the pre- and post-EMC secular rates, we calculate long-term changes associated with viscoelastic relaxation in the Salton Trough region. We fit these velocity changes using numerical models employing an elastic upper crustal layer underlain by a viscoelastic lower crustal layer and a mantle half-space. Forward models that produce the smallest weighted sum of squared residuals have an upper mantle viscosity in the range 4-6 × 1018 Pa s and a less well-resolved lower crustal viscosity in the range 2 × 1019 to 1 × 1022 Pa s. A high-viscosity lower crust, despite high heat flow in the Salton Trough region, is inconsistent with felsic composition and might suggest accretion of mafic lower crust associated with crustal spreading obscured by thick sedimentary cover.

  3. RailroadValleySpringfish_CH

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These data identify the areas where final critical habitat for the Railroad Valley springfish (Crenichthys nevadae) occur. The irrigation ditch that is on the north...

  4. Asynchronous behavior of the Antarctic Ice Sheet and local glaciers during and since Termination 1, Salmon Valley, Antarctica

    Science.gov (United States)

    Jackson, Margaret S.; Hall, Brenda L.; Denton, George H.

    2018-01-01

    The stability of the Antarctic Ice Sheet under future warming remains an open question with broad implications for sea-level prediction and adaptation. In particular, knowledge of whether the ice sheet has the capacity for rapid drawdown or collapse, or whether it can remain stable during periods of warming, is essential for predicting its future behavior. Here we use 55 radiocarbon dates, coupled with geomorphologic mapping, to reconstruct the timing of changes in ice extent and elevation during the last ice-age termination in Salmon Valley, adjacent to McMurdo Sound in the western Ross Sea Embayment. Results indicate that a grounded ice sheet in the Ross Sea Embayment achieved its maximum elevation and extent along the headlands of Salmon Valley at ∼18,000 yr BP, during a period of increasing temperatures and accumulation over the Antarctic continent. This ice remained at or near its maximum on the headlands near the valley mouth until after ∼14,000 yr BP. Removal of grounded Ross Sea ice from Salmon Valley was complete shortly after ∼7900 yr BP, indicating that the grounding line had retreated through southern McMurdo Sound by that time. We suggest the primary driver of Ross Sea ice removal from McMurdo Sound was marine-based, either through basal melting or calving due to sea-level rise. When combined with regional data, the Salmon Valley record suggests that this sector of the Antarctic Ice Sheet did not contribute in a significant way to deglacial meltwater pulses, such as meltwater pulse 1a. In contrast to the Ross Sea ice, our work also shows that local, independent alpine glaciers in Salmon Valley have advanced through the Holocene. Land-terminating glaciers such as these elsewhere in the region show a similar pattern, and may reflect the continued influence of increased accumulation following the termination of the last ice age.

  5. Influence of system controls on the Late Quaternary geomorphic evolution of a rapidly-infilled incised-valley system: The lower Manawatu valley, North Island New Zealand

    Science.gov (United States)

    Clement, Alastair J. H.; Fuller, Ian C.

    2018-02-01

    The Manawatu incised-valley estuary was rapidly infilled between 12,000-4700 cal. yr BP. A combination of empirical measurements of sedimentation rates, a reconstruction of relative sea-level (RSL) change, and digital elevation models of key surfaces within the Holocene sedimentary fill of the valley were integrated to produce a numerical model to investigate the influence of the system controls of sea-level change, sediment flux, and accommodation space on the rapid infilling history of the palaeo-estuary. The numerical model indicates that sediment flux into the palaeo-estuary was greatest during the Holocene marine transgression between 12,000-8000 years BP. The average rate of sediment deposition in the estuary during this period was 1.0 M m3 yr- 1. This rapid rate of sedimentation was controlled by the rate of accommodation space creation, as regulated by the rate of sea-level rise and the antecedent configuration of the valley. By the time sea levels stabilised c. 7500 cal. yr BP, the palaeo-estuary had been substantively infilled. Limited accommodation space resulted in rapid infilling of the central basin, though sediment flux into the estuary between 7100 and 4500 cal. yr BP was at a lower rate of 234,000 m3 yr- 1. The limited accommodation space also influenced hydrodynamic conditions in the estuarine central basin, driving export of fine-grained sediment from the estuary. Once the accommodation space of the estuarine basin was infilled sediment bypassed the system, with a consequent reduction in the sedimentation rate in the valley. More accurate partitioning of the sources of sediment driving the infilling is necessary to quantify sediment bypassing. Post-depositional lowering of RSL index points from the valley is driven by neotectonics and sediment compaction.

  6. Luminescence dating of paleolake deltas and glacial deposits in Garwood Valley, Antarctica: Implications for climate, Ross ice sheet dynamics, and paleolake duration

    Science.gov (United States)

    Levy, Joseph S.; Rittenour, Tammy M.; Fountain, Andrew G.; O'Connor, Jim E.

    2017-01-01

    The formation of perched deltas and other lacustrine deposits in the McMurdo Dry Valleys of Antarctica is widely considered to be evidence of valley-filling lakes dammed by the grounded Ross Sea ice sheet during the local Last Glacial Maximum, with lake drainage interpreted as a record of grounding line retreat. We used luminescence dating to determine the age of paleolake deltas and glacial tills in Garwood Valley, a coastal dry valley that opens to the Ross Sea. Luminescence ages are stratigraphically consistent with radiocarbon results from algal mats within the same delta deposits but suggest radiocarbon dates from lacustrine carbonates may overestimate deposit ages by thousands of years. Results suggest that late Holocene delta deposition into paleolake Howard in Garwood Valley persisted until ca. 3.5 ka. This is significantly younger than the date when grounded ice is thought to have retreated from the Ross Sea. Our evidence suggests that the local, stranded ice-cored till topography in Garwood Valley, rather than regional ice-sheet dynamics, may have controlled lake levels for some McMurdo Dry Valleys paleolakes. Age control from the supraglacial Ross Sea drift suggests grounding and up-valley advance of the Ross Sea ice sheet into Garwood valley during marine oxygen isotope stage (MIS) 4 (71–78 ka) and the local Last Glacial Maximum (9–10 ka). This work demonstrates the power of combining luminescence dating with existing radiocarbon data sets to improve understanding of the relationships among paleolake formation, glacial position, and stream discharge in response to climate change.

  7. Modelling photochemistry in alpine valleys

    Directory of Open Access Journals (Sweden)

    G. Brulfert

    2005-01-01

    Full Text Available Road traffic is a serious problem in the Chamonix Valley, France: traffic, noise and above all air pollution worry the inhabitants. The big fire in the Mont-Blanc tunnel made it possible, in the framework of the POVA project (POllution in Alpine Valleys, to undertake measurement campaigns with and without heavy-vehicle traffic through the Chamonix and Maurienne valleys, towards Italy (before and after the tunnel re-opening. Modelling is one of the aspects of POVA and should make it possible to explain the processes leading to episodes of atmospheric pollution, both in summer and in winter. Atmospheric prediction model ARPS 4.5.2 (Advanced Regional Prediction System, developed at the CAPS (Center for Analysis and Prediction of Storms of the University of Oklahoma, enables to resolve the dynamics above a complex terrain. This model is coupled to the TAPOM 1.5.2 atmospheric chemistry (Transport and Air POllution Model code developed at the Air and Soil Pollution Laboratory of the Ecole Polytechnique Fédérale de Lausanne. The numerical codes MM5 and CHIMERE are used to compute large scale boundary forcing. This paper focuses on modelling Chamonix valley using 300-m grid cells to calculate the dynamics and the reactive chemistry which makes possible to accurately represent the dynamics in the Chamonix valley (slope and valley winds and to process chemistry at fine scale. The summer 2003 intensive campaign was used to validate the model and to study chemistry. NOy according to O3 reduction demonstrates a VOC controlled regime, different from the NOx controlled regime expected and observed in the nearby city of Grenoble.

  8. EPA Region 1 - Valley Depth in Meters

    Data.gov (United States)

    U.S. Environmental Protection Agency — Raster of the Depth in meters of EPA-delimited Valleys in Region 1. Valleys (areas that are lower than their neighbors) were extracted from a Digital Elevation Model...

  9. The Central Valley Hydrologic Model

    Science.gov (United States)

    Faunt, C.; Belitz, K.; Hanson, R. T.

    2009-12-01

    Historically, California’s Central Valley has been one of the most productive agricultural regions in the world. The Central Valley also is rapidly becoming an important area for California’s expanding urban population. In response to this competition for water, a number of water-related issues have gained prominence: conjunctive use, artificial recharge, hydrologic implications of land-use change, subsidence, and effects of climate variability. To provide information to stakeholders addressing these issues, the USGS made a detailed assessment of the Central Valley aquifer system that includes the present status of water resources and how these resources have changed over time. The principal product of this assessment is a tool, referred to as the Central Valley Hydrologic Model (CVHM), that simulates surface-water flows, groundwater flows, and land subsidence in response to stresses from human uses and from climate variability throughout the entire Central Valley. The CVHM utilizes MODFLOW combined with a new tool called “Farm Process” to simulate groundwater and surface-water flow, irrigated agriculture, land subsidence, and other key processes in the Central Valley on a monthly basis. This model was discretized horizontally into 20,000 1-mi2 cells and vertically into 10 layers ranging in thickness from 50 feet at the land surface to 750 feet at depth. A texture model constructed by using data from more than 8,500 drillers’ logs was used to estimate hydraulic properties. Unmetered pumpage and surface-water deliveries for 21 water-balance regions were simulated with the Farm Process. Model results indicate that human activities, predominately surface-water deliveries and groundwater pumping for irrigated agriculture, have dramatically influenced the hydrology of the Central Valley. These human activities have increased flow though the aquifer system by about a factor of six compared to pre-development conditions. The simulated hydrology reflects spatial

  10. Cosseno de Salton, Índice de Jaccard e Correlação de Pearson: comparando índices normalizados e absolutos em análise de cocitação de autores

    Directory of Open Access Journals (Sweden)

    Ely Francina Tannuri de Oliveira

    2017-01-01

    Full Text Available Esta pesquisa objetiva realizar um estudo comparativo entre os indicadores absolutos e os normalizados, para Análise de Cocitação de Autores, a saber: Cosseno de Salton (CS, Índice de Jaccard (IJ e Correlação de Pearson (r. , Visa apresentar os três índices normalizados, apontar as diferenças no uso entre os indicadores absolutos e normalizados, avaliar questões sobre a escolha dos três indicadores e apresentar um estudo teórico-aplicado. Ainda, calcular a Correlação de Spearman entre a matriz com os valores absolutos de cocitação e os três diferentes índices normalizados - Cosseno de Salton (CS, Índice de Jaccard (IJ e Correlação de Pearson (r. Como fonte de dados, utilizaram-se os artigos do periódico Scientometrics, pertencente à base de dados Scopus na temática Estudos Métricos. Recuperaram-se 234 artigos do período de 2013 e 2014, em junho de 2015. Identificaram-se 9.327 pesquisadores citados. Gerou-se a matriz absoluta dos autores mais cocitados e procederam-se às normalizações pelos três processos. No sentido de comparar os resultados da matriz absoluta com os respectivos índices normalizados Cosseno de Salton (CS, Índice de Jaccard (IJ e Correlação de Pearson (r, calculou-se a Correlação de Spearman, a partir do pareamento dos dados absolutos e dos normalizados de cada uma das matrizes, ordenados em postos, com a finalidade de sugerir o melhor indicador normalizado. Apresentaram-se os gráficos de dispersão e concluiu-se pelo uso de preferencial do Cosseno de Salton (Cs, a partir dos objetivos da pesquisa, da natureza dos dados e da maior significância relativa à Correlação de Spearman.

  11. Load structure seismites in the Dead Sea Area, Israel : Chronological benchmarking with C-14 dating

    NARCIS (Netherlands)

    Bowman, D; Bruins, HJ; van der Plicht, J; Boaretto, E.; Bruins, Hendrik J.; Carmi, I.

    2001-01-01

    The Dead Sea is a terminal lake located in the seismically active zone of the Syro-African Rift Valley. The water level of the Dead Sea has been receding dramatically during the last decades, resulting in significant entrenchment of wadis towards its shores. Exposed sections in fan deltas reveal

  12. Mechanically and optically controlled graphene valley filter

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Fenghua; Jin, Guojun, E-mail: gjin@nju.edu.cn [National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093 (China)

    2014-05-07

    We theoretically investigate the valley-dependent electronic transport through a graphene monolayer modulated simultaneously by a uniform uniaxial strain and linearly polarized light. Within the Floquet formalism, we calculate the transmission probabilities and conductances of the two valleys. It is found that valley polarization can appear only if the two modulations coexist. Under a proper stretching of the sample, the ratio of the light intensity and the light frequency squared is important. If this quantity is small, the electron transport is mainly contributed by the valley-symmetric central band and the conductance is valley unpolarized; but when this quantity is large, the valley-asymmetric sidebands also take part in the transport and the valley polarization of the conductance appears. Furthermore, the degree of the polarization can be tuned by the strain strength, light intensity, and light frequency. It is proposed that the detection of the valley polarization can be realized utilizing the valley beam splitting. Thus, a graphene monolayer can be used as a mechanically and optically controlled valley filter.

  13. The Microclimate of Valley Glaciers

    OpenAIRE

    Oerlemans, J.

    2010-01-01

    Glaciers have fascinated mankind throughout history. Glaciers look solid and robust, but observing them for only a couple of years shows that they are dynamic and change shape all the time. The lower glaciers come, the greater the contrast with the surrounding landscape. Many glaciers in the world enter pastures and forests. It is not surprising that laymen, artists and scientists have reported on the behaviour of large valley glaciers. A wealth of information on glacier fluctuations in histo...

  14. Synoptic conditions of fine-particle transport to the last interglacial Red Sea-Dead Sea from Nd-Sr compositions of sediment cores

    Science.gov (United States)

    Palchan, Daniel; Stein, Mordechai; Goldstein, Steven L.; Almogi-Labin, Ahuva; Tirosh, Ofir; Erel, Yigal

    2018-01-01

    The sediments deposited at the depocenter of the Dead Sea comprise high-resolution archive of hydrological changes in the lake's watershed and record the desert dust transport to the region. This paper reconstructs the dust transport to the region during the termination of glacial Marine Isotope Stage 6 (MIS 6; ∼135-129 ka) and the last interglacial peak period (MIS5e, ∼129-116 ka). We use chemical and Nd and Sr isotope compositions of fine detritus material recovered from sediment core drilled at the deepest floor of the Dead Sea. The data is integrated with data achieved from cores drilled at the floor of the Red Sea, thus, forming a Red Sea-Dead Sea transect extending from the desert belt to the Mediterranean climate zone. The Dead Sea accumulated flood sediments derived from three regional surface cover types: settled desert dust, mountain loess-soils and loess-soils filling valleys in the Dead Sea watershed termed here "Valley Loess". The Valley Loess shows a distinct 87Sr/86Sr ratio of 0.7081 ± 1, inherited from dissolved detrital calcites that originate from dried waterbodies in the Sahara and are transported with the dust to the entire transect. Our hydro-climate and synoptic conditions reconstruction illustrates the following history: During glacial period MIS6, Mediterranean cyclones governed the transport of Saharan dust and rains to the Dead Sea watershed, driving the development of both mountain soils and Valley Loess. Then, at Heinrich event 11, dry western winds blew Saharan dust over the entire Red Sea - Dead Sea transect marking latitudinal expansion of the desert belt. Later, when global sea-level rose, the Dead Sea watershed went through extreme aridity, the lake retreated, depositing salt and accumulating fine detritus of the Valley Loess. During peak interglacial MIS 5e, enhanced flooding activity flushed the mountain soils and fine detritus from all around the Dead Sea and Red Sea, marking a significant "contraction" of the desert belt

  15. Spin-Valley Beam Splitter in Graphene

    CERN Document Server

    Song, Yu; Shi, Zhi-Gui; Li, Shun; Zhang, Jian

    2016-01-01

    The fourfold spin-valley degenerate degrees of freedom in bulk graphene can support rich physics and novel applications associated with multicomponent quantum Hall effects and linear conductance filtering. In this work, we study how to break the spin-valley degeneracy of electron beams spatially. We propose a spin-valley beam splitter in a gated ferromagnetic/pristine/strained graphene structure. We demonstrate that, in a full resonant tunneling regime for all spin-valley beam components, the formation of quasi-standing waves can lead four giant lateral Goos-H\\"{a}nchen shifts as large as the transverse beam width, while the interplay of the two modulated regions can lead difference of resonant angles or energies for the four spin-valley flavors, manifesting an effective spin-valley beam splitting effect. The beam splitting effect is found to be controllable by the gating and strain.

  16. Two new species of the genus Longicheles Valle, 1953 from the Kelkit Valley, Turkey, with redescription Longicheles lagrecai (Valle, 1963) (Acari: Macrochelidae).

    Science.gov (United States)

    Hasan Hüseyin, Özbek; Durmuş Ali, Bal; Salih, Doğan

    2013-01-01

    The Kelkit Valley is geographically a transitional zone between the Middle Black Sea and Inner Anatolia regions in Turkey. Two new species of Macrochelidae are described from this area--Longicheles ozkani sp. nov. and Longicheles ayyildizi sp. nov. Longicheles lagrecai (Valle, 1963) is recorded for the Turkish fauna and redescribed on the basis of specimens collected from the Valley. A world-wide key to species of Longicheles Valle is provided.

  17. California's restless giant: the Long Valley Caldera

    Science.gov (United States)

    Hill, David P.; Bailey, Roy A.; Hendley, James W.; Stauffer, Peter H.; Marcaida, Mae

    2014-01-01

    Scientists have monitored geologic unrest in the Long Valley, California, area since 1980. In that year, following a swarm of strong earthquakes, they discovered that the central part of the Long Valley Caldera had begun actively rising. Unrest in the area persists today. The U.S. Geological Survey (USGS) continues to provide the public and civil authorities with current information on the volcanic hazard at Long Valley and is prepared to give timely warnings of any impending eruption.

  18. Strike-slip Fault Structure in the Salton Trough and Deformation During and After the 2010 M7.2 El Mayor-Cucapah Earthquake from Geodetic and Seismic Data

    Science.gov (United States)

    Fielding, E. J.; Sun, J.; Gonzalez-Ortega, A.; González-Escobar, M.; Freed, A. M.; Burgmann, R.; Samsonov, S. V.; Gonzalez-Garcia, J.; Fletcher, J. M.; Hinojosa, A.

    2013-12-01

    The Pacific-North America plate boundary character changes southward from the strike-slip and transpressional configuration along most of California to oblique rifting in the Gulf of California, with a transitional zone of transtension beneath the Salton Trough in southernmost California and northern Mexico. The Salton Trough is characterized by extremely high heat flow and thin lithosphere with a thick fill of sedimentary material delivered by the Colorado River during the past 5-6 million years. Because of the rapid sedimentation, most of the faults in Salton Trough are buried and reveal themselves when they slip either seismically or aseismically. They can also be located by refraction and reflection of seismic waves. The 4 April 2010 El Mayor-Cucapah earthquake (Mw 7.2) in Baja California and Sonora, Mexico is probably the largest earthquake in the Salton Trough for at least 120 years, and had primarily right-lateral strike-slip motion. The earthquake ruptured a complex set of faults that lie to the west of the main plate boundary fault, the Cerro Prieto Fault, and shows that the strike-slip fault system in the southern Salton Trough has multiple sub-parallel active faults, similar to southern California. The Cerro Prieto Fault is still likely absorbing the majority of strain in the plate boundary. We study the coseismic and postseismic deformation of the 2010 earthquake with interferometric analysis of synthetic aperture radar (SAR) images (InSAR) and pixel tracking by subpixel correlation of SAR and optical images. We combine sampled InSAR and subpixel correlation results with GPS (Global Positioning System) offsets at PBO (Plate Boundary Observatory) stations to estimate the likely subsurface geometry of the major faults that slipped during the earthquake and to derive a static coseismic slip model. We constrained the surface locations of the fault segments to mapped locations in the Sierra Cucapah to the northwest of the epicenter. SAR along-track offsets

  19. A landscape scale valley confinement algorithm: Delineating unconfined valley bottoms for geomorphic, aquatic, and riparian applications

    Science.gov (United States)

    David E. Nagel; John M. Buffington; Sharon L. Parkes; Seth Wenger; Jaime R. Goode

    2014-01-01

    Valley confinement is an important landscape characteristic linked to aquatic habitat, riparian diversity, and geomorphic processes. This report describes a GIS program called the Valley Confinement Algorithm (VCA), which identifies unconfined valleys in montane landscapes. The algorithm uses nationally available digital elevation models (DEMs) at 10-30 m resolution to...

  20. Novel magnetite-producing magnetotactic bacteria belonging to the Gammaproteobacteria

    OpenAIRE

    Christopher T Lefèvre; Viloria, Nathan; Schmidt, Marian L.; Pósfai, Mihály; Frankel, Richard B.; Bazylinski, Dennis A.

    2011-01-01

    Two novel magnetotactic bacteria (MTB) were isolated from sediment and water collected from the Badwater Basin, Death Valley National Park and southeastern shore of the Salton Sea, respectively, and were designated as strains BW-2 and SS-5, respectively. Both organisms are rod-shaped, biomineralize magnetite, and are motile by means of flagella. The strains grow chemolithoautotrophically oxidizing thiosulfate and sulfide microaerobically as electron donors, with thiosulfate oxidized stoichiom...

  1. Hydrology and simulation of ground-water flow in Juab Valley, Juab County, Utah.

    Science.gov (United States)

    Thiros, Susan A.; Stolp, Bernard J.; Hadley, Heidi K.; Steiger, Judy I.

    1996-01-01

    Plans to import water to Juab Valley, Utah, primarily for irrigation, are part of the Central Utah Project. A better understanding of the hydrology of the valley is needed to help manage the water resources and to develop conjunctive-use plans.The saturated unconsolidated basin-fill deposits form the ground-water system in Juab Valley. Recharge is by seepage from streams, unconsumed irrigation water, and distribution systems; infiltration of precipitation; and subsurface inflow from consolidated rocks that surround the valley. Discharge is by wells, springs, seeps, evapotranspiration, and subsurface outflow to consolidated rocks. Ground-water pumpage is used to supplement surface water for irrigation in most of the valley and has altered the direction of groundwater flow from that of pre-ground-water development time in areas near and in Nephi and Levan.Greater-than-average precipitation during 1980-87 corresponds with a rise in water levels measured in most wells in the valley and the highest water level measured in some wells. Less-than average precipitation during 1988-91 corresponds with a decline in water levels measured during 1988-93 in most wells. Geochemical analyses indicate that the sources of dissolved ions in water sampled from the southern part of the valley are the Arapien Shale, evaporite deposits that occur in the unconsolidated basin-fill deposits, and possibly residual sea water that has undergone evaporation in unconsolidated basin-fill deposits in selected areas. Water discharging from a spring at Burriston Ponds is a mixture of about 70 percent ground water from a hypothesized flow path that extends downgradient from where Salt Creek enters Juab Valley and 30 percent from a hypothesized flow path from the base of the southern Wasatch Range.The ground-water system of Juab Valley was simulated by using the U.S. Geological Survey modular, three-dimensional, finite-difference, ground-water flow model. The numerical model was calibrated to simulate

  2. Vernal Pool Distribution - Central Valley, 2005 [ds650

    Data.gov (United States)

    California Department of Resources — "Great Valley Vernal Pool Distribution", originally mapped by Bob Holland, 2005. This dataset contains vernal pool areas mapped over Califorina's Central Valley,...

  3. Valley filtering due to orbital magnetic moment in bilayer graphene

    Science.gov (United States)

    Park, Chang-Soo

    2018-01-01

    We investigate the effect of valley-dependent orbital magnetic moment on the transmission of quasiparticles through biased bilayer graphene npn and pnp junctions in the presence of out-of-plane magnetic field. It is shown that the valley-polarized Zeeman-like energy splitting, due to the interaction of orbital magnetic moment with magnetic field, can suppress the transmission of quasiparticles of one valley while transmitting those of the other valley. This valley-selective transmission property can be exploited for valley filtering. We demonstrate that the npn and pnp junction, respectively, filters off the K‧-valley and K-valley particles, with nearly perfect degree of filtration.

  4. 27 CFR 9.100 - Mesilla Valley.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Mesilla Valley. 9.100 Section 9.100 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT... Mesilla Valley viticultural area is located within Dona Ana County, New Mexico, and El Paso County, Texas...

  5. Valley Pearl’ table grape

    Science.gov (United States)

    Valley Pearl’ is an early to mid-season, white seedless table grape (Vitis vinifera L.) suitable for commercial table grape production where V. vinifera can be grown. Significant characteristics of ‘Valley Pearl’ are its high and consistent fruit production on spur pruned vines and large round berr...

  6. Beaver assisted river valley formation

    Science.gov (United States)

    Westbrook, C.J.; Cooper, D.J.; Baker, B.W.

    2011-01-01

    We examined how beaver dams affect key ecosystem processes, including pattern and process of sediment deposition, the composition and spatial pattern of vegetation, and nutrient loading and processing. We provide new evidence for the formation of heterogeneous beaver meadows on riverine system floodplains and terraces where dynamic flows are capable of breaching in-channel beaver dams. Our data show a 1.7-m high beaver dam triggered overbank flooding that drowned vegetation in areas deeply flooded, deposited nutrient-rich sediment in a spatially heterogeneous pattern on the floodplain and terrace, and scoured soils in other areas. The site quickly de-watered following the dam breach by high stream flows, protecting the deposited sediment from future re-mobilization by overbank floods. Bare sediment either exposed by scouring or deposited by the beaver flood was quickly colonized by a spatially heterogeneous plant community, forming a beaver meadow. Many willow and some aspen seedlings established in the more heavily disturbed areas, suggesting the site may succeed to a willow carr plant community suitable for future beaver re-occupation. We expand existing theory beyond the beaver pond to include terraces within valleys. This more fully explains how beavers can help drive the formation of alluvial valleys and their complex vegetation patterns as was first postulated by Ruedemann and Schoonmaker in 1938. ?? 2010 John Wiley & Sons, Ltd.

  7. Relative sea-level variability during the late Middle Pleistocene: New evidence from eastern England

    Science.gov (United States)

    Barlow, N. L. M.; Long, A. J.; Gehrels, W. R.; Saher, M. H.; Scaife, R. G.; Davies, H. J.; Penkman, K. E. H.; Bridgland, D. R.; Sparkes, A.; Smart, C. W.; Taylor, S.

    2017-10-01

    Unravelling patterns of relative sea-level change during previous interglacials enhances our understanding of ice sheet response to changing climate. Temperate-latitude estuarine environments have the potential to preserve continuous records of relative sea level from previous interglacial (warm) periods. This is important because, currently, we typically only have snapshots of sea-level highstands from low-latitude corals and raised palaeoshoreline indicators while the (continuous) deep-sea oxygen isotope record only provides indirect evidence of sea-level changes. Here, we focus on the Nar Valley in eastern England, in which is preserved evidence of a late middle-Pleistocene marine transgression more than 20 vertical metres in extent. By applying a model of coastal succession and sea-level tendencies, as used in Holocene sea-level studies, we assess the mode (abrupt versus gradual) of sea-level change recorded by the interglacial Nar Valley sequences. Compiled palaeo-stratigraphic evidence comprising foraminifera, pollen and amino acid racemization dating, suggests that the mode of sea-level change in the Nar Valley interglacial sequence was gradual, with potentially two phases of regional transgression and relative sea-level rise occurring at two separate times. The first phase occurred during the latter part of marine Oxygen Isotope Stage (MIS) 11 from ∼8 to 18 m OD; and, the second phase potentially occurred during early MIS 9 from ∼-3 to 3 m OD (with long-term tectonic uplift included in these estimates). We cannot conclusively preclude an alternative MIS 11 age for these lower sediments. The lack of indicators for rapid sea-level oscillations in the Nar Valley adds weight to an argument for steady melt of the ice sheets during both MIS 11 and 9.

  8. Transforming the "Valley of Death" into a "Valley of Opportunity"

    Science.gov (United States)

    Jedlovec, Gary J.; Merceret, Francis J.; O'Brien, T. P.; Roeder, William P.; Huddleston, Lisa L.; Bauman, William H., III

    2014-01-01

    Transitioning technology from research to operations (23 R2O) is difficult. The problem's importance is exemplified in the literature and in every failed attempt to do so. Although the R2O gap is often called the "valley of death", a recent a Space Weather editorial called it a "Valley of Opportunity". There are significant opportunities for space weather organizations to learn from the terrestrial experience. Dedicated R2O organizations like those of the various NOAA testbeds and collaborative "proving ground" projects take common approaches to improving terrestrial weather forecasting through the early transition of research capabilities into the operational environment. Here we present experience-proven principles for the establishment and operation of similar space weather organizations, public or private. These principles were developed and currently being demonstrated by NASA at the Applied Meteorology Unit (AMU) and the Short-term Prediction Research and Transition (SPoRT) Center. The AMU was established in 1991 jointly by NASA, the U.S. Air Force (USAF) and the National Weather Service (NWS) to provide tools and techniques for improving weather support to the Space Shuttle Program (Madura et al., 2011). The primary customers were the USAF 45th Weather Squadron (45 WS) and the NWS Spaceflight Meteorology Group (SMG who provided the weather observing and forecast support for Shuttle operations). SPoRT was established in 2002 to transition NASA satellite and remote-sensing technology to the NWS. The continuing success of these organizations suggests the common principles guiding them may be valuable for similar endeavors in the space weather arena.

  9. Pull-apart basin formation and development in narrow transform zones with application to the Dead Sea Basin

    NARCIS (Netherlands)

    Smit, J.H.W.; Brun, J.P.; Cloetingh, S.A.P.L.; Ben-Avraham, Z.

    2008-01-01

    Contrary to other examples, like Death Valley, California, and the Sea of Marmara, Turkey, the Dead Sea-type pull-apart basins form within a narrow transform corridor between strike-slip faults that are less than 10 km apart, much smaller than the crustal thickness of 35 km. In this paper we

  10. Photosensitive Epilepsy In Kashmir Valley

    Directory of Open Access Journals (Sweden)

    Saleem S M

    2003-01-01

    Full Text Available A random population of 618 people with epilepsy hailing from different parts of Kashmir valley was screened for photosensitivity both clinically and on a standard protocol of intermittent photic stimulation (IPS provoked EEG recordings. Six (0.9% patients with a mean age of 15+6.57 years were found to be photosensitive; five had generalized and one had absence seizures. The baseline EEG in all patients showed generalized epileptiform discharges. On IPS, similar EEG findings were obtained with a narrow range of stimulus frequency i.e. 7-12 cycles/sec. There appears to be a low prevalence of photo-sensitivity in our epileptic population, possibly related to genetic factors.

  11. 27 CFR 9.78 - Ohio River Valley.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Ohio River Valley. 9.78... River Valley. (a) Name. The name of the viticultural area described in this section is “Ohio River Valley.” (b) Approved maps. The approved maps for determining the boundary of the Ohio River Valley...

  12. Hydrothermal system of Long Valley caldera, California

    Energy Technology Data Exchange (ETDEWEB)

    Sorey, M.L.; Lewis, R.E.; Olmsted, F.H.

    1978-01-01

    The geologic and hydrologic setting of the hydrothermal system are described. The geochemical and thermal characteristics of the system are presented. A mathematical model of the Long Valley caldera is analyzed. (MHR)

  13. Alluvial Boundary of California's Central Valley

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset defines the extent of the alluvial deposits in the Central Valley of California and encompasses the contiguous Sacramento, San Joaquin, and...

  14. Meie ingel Silicon Valleys / Raigo Neudorf

    Index Scriptorium Estoniae

    Neudorf, Raigo

    2008-01-01

    Ettevõtluse Arendamise Sihtasutuse esinduse töölepanekust USAs Silicon Valleys räägib esinduse juht Andrus Viirg. Vt. ka: Eestlasi leidub San Franciscos omajagu; Muljetavaldav karjäär; USAga ammune tuttav

  15. Meie mees Silicon Valleys / Kertu Ruus

    Index Scriptorium Estoniae

    Ruus, Kertu, 1977-

    2007-01-01

    Ilmunud ka: Delovõje Vedomosti 5. dets. lk. 4. Peaminister Andrus Ansip avas Eesti Ettevõtluse Sihtasutuse esinduse Silicon Valley pealinnas San Joses. Vt. samas: Ränioru kliima on tehnoloogiasõbralik; Andrus Viirg

  16. Vegetation - San Felipe Valley [ds172

    Data.gov (United States)

    California Department of Resources — This Vegetation Map of the San Felipe Valley Wildlife Area in San Diego County, California is based on vegetation samples collected in the field in 2002 and 2005 and...

  17. Detection of valley currents in graphene nanoribbons

    Science.gov (United States)

    Chan, K. S.

    2018-02-01

    There are two valleys in the band structure of graphene zigzag ribbons, which can be used to construct valleytronic devices. We studied the use of a T junction formed by an armchair ribbon and a zigzag ribbon to detect the valley-dependent currents in a zigzag graphene ribbon. A current flowing in a zigzag ribbon is divided by the T junction into the zigzag and armchair leads and this separation process is valley dependent. By measuring the currents in the two outgoing leads, the valley-dependent currents in the incoming lead can be determined. The method does not require superconducting or magnetic elements as in other approaches and thus will be useful in the development of valleytronic devices.

  18. Airborne Dust Models in Valley Fever Research

    Science.gov (United States)

    Sprigg, W. A.; Galgiani, J. N.; Vujadinovic, M.; Pejanovic, G.; Vukovic, A. J.; Prasad, A. K.; Djurdjevic, V.; Nickovic, S.

    2011-12-01

    Dust storms (haboobs) struck Phoenix, Arizona, in 2011 on July 5th and again on July 18th. One potential consequence: an estimated 3,600 new cases of Valley Fever in Maricopa County from the first storm alone. The fungi, Coccidioides immitis, the cause of the respiratory infection, Valley Fever, lives in the dry desert soils of the American southwest and southward through Mexico, Central America and South America. The fungi become part of the dust storm and, a few weeks after inhalation, symptoms of Valley Fever may appear, including pneumonia-like illness, rashes, and severe fatigue. Some fatalities occur. Our airborne dust forecast system predicted the timing and extent of the storm, as it has done with other, often different, dust events. Atmosphere/land surface models can be part of public health services to reduce risk of Valley Fever and exacerbation of other respiratory and cardiovascular illness.

  19. VALMET-A valley air pollution model

    Energy Technology Data Exchange (ETDEWEB)

    Whiteman, C.D.; Allwine, K.J.

    1983-09-01

    Following a thorough analysis of meteorological data obtained from deep valleys of western Colorado, a modular air-pollution model has been developed to simulate the transport and diffusion of pollutants released from an elevated point source in a well-defined mountain valley during the nighttime and morning transition periods. This initial version of the model, named VALMET, operates on a valley cross section at an arbitrary distance down-valley from a continuous point source. The model has been constructed to include parameterizations of the major physical processes that act to disperse pollution during these time periods. The model has not been fully evaluated. Further testing, evaluations, and development of the model are needed. Priorities for further development and testing are provided.

  20. Burrowing Owl - Palo Verde Valley [ds197

    Data.gov (United States)

    California Department of Resources — These burrowing owl observations were collected during the spring and early summer of 1976 in the Palo Verde Valley, eastern Riverside County, California. This is an...

  1. New River Valley Agriculture & Agritourism Strategic Plan

    OpenAIRE

    Walker, Martha A.; Scott, Kelli H.

    2017-01-01

    This strategic plan discusses plans for improving the marketing of agritourism and agribusiness in the New River Valley (Floyd, Giles, Montgomery and Pulaski Counties), and potentially increasing community wealth while improving the access to local crops and products. Includes Planning for an Agricultural Future in Giles, Montgomery, and Pulaski Counties: An Agricultural Regional Assessment, prepare for the New River Valley Agricultural & Agritourism Project Management Team by Matson Consu...

  2. The impact of the lithospheric flexure during the Elsterian glacial maximum on post-/proglacial systems in the southern North Sea area

    DEFF Research Database (Denmark)

    Moreau, Julien; Le Pourhiet, Laetitia; Huuse, Mads

    Tunnel valleys have long fascinated the geoscientists by their scale and the consequent intensity of the sedimentary processes necessary to their formation. The filling of tunnel valleys in the southern and eastern North Sea is mainly made of clinoforms prograding north. A new sedimentological...... tunnel valleys). The presence of clinoforms 5080 m above the valley shoulders indicates the potential depth of the lake. The lake geometry was certainly controlled by the lithospheric flexure depression and forebulge due to ice sheet loading, during or after ice sheet recession. The lake levels might...

  3. Surface atmospheric circulation patterns and associated minimum temperatures in the Maipo and Casablanca valleys, central Chile

    Science.gov (United States)

    Montes, Carlo; Muñoz, Ricardo C.; Perez-Quezada, Jorge F.

    2013-01-01

    This paper analyzes the influence of circulation anomalies on the magnitude of minimum air temperature ( T min) at a daily scale in two important agricultural valleys of Chile (Maipo and Casablanca) during the period 2001-2007. A statistical classification of synoptic fields was performed, resulting in eight circulation patterns (CPs, 84 % of explained variance). The corresponding anomalies of T min (ATmin) of each CP were analyzed in order to understand their synoptic-scale forcing mechanisms. Results showed a direct association between ATmin and the synoptic structure. The average weakening in sea level pressure (SLP) yields positive ATmin, while negative ATmin is associated with a strengthening in SLP. In the latter case, it was also found that a synoptic structure (10.2 % of frequency) corresponding to a migratory high-pressure system passing eastward across the Andes led to the lowest ATmin and a higher probability of frost in both valleys (22 % on average) in winter and springtime.

  4. PEARLS OF THE PČINJA VALLEY – RURAL TOURISM ATTRACTIONS OF THIS AREA

    Directory of Open Access Journals (Sweden)

    Svetlana Trajković

    2013-10-01

    Full Text Available River Valley Pčinja, with its source part and tributaries that make up the Aegean Sea with its configuration, where the gorge turns between nearby mountains and flat areas, meadows, gardens and of our arable land, remains of old mills, houses and villages, which, still do not leave the inhabitants of this region, contains tourist potential. This valley is adorned with rich flora and fauna where one can see examples of the unique flora and fauna, with its diversity and natural material in the form of a "devil's stone" Witness antiquities and places of worship as well as a special value of the Monastery of St. Prohor of Pcinja. The pleasant climate and in some areas of the river gurgling disrupts primordial peace and makes the holiday for eyes, soul of every lover of nature.

  5. Topological Valley Transport in Two-dimensional Honeycomb Photonic Crystals.

    Science.gov (United States)

    Yang, Yuting; Jiang, Hua; Hang, Zhi Hong

    2018-01-25

    Two-dimensional photonic crystals, in analogy to AB/BA stacking bilayer graphene in electronic system, are studied. Inequivalent valleys in the momentum space for photons can be manipulated by simply engineering diameters of cylinders in a honeycomb lattice. The inequivalent valleys in photonic crystal are selectively excited by a designed optical chiral source and bulk valley polarizations are visualized. Unidirectional valley interface states are proved to exist on a domain wall connecting two photonic crystals with different valley Chern numbers. With the similar optical vortex index, interface states can couple with bulk valley polarizations and thus valley filter and valley coupler can be designed. Our simple dielectric PC scheme can help to exploit the valley degree of freedom for future optical devices.

  6. Christmas Valley Renewable Energy Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Del Mar, Robert [Oregon Department of Energy, Salem, OR (United States)

    2017-05-22

    In partnership with the Oregon Military Department, the Department of Energy used the award to assess and evaluate renewable resources in a 2,622-acre location in Lake County, central Oregon, leading to future development of up to 200 MW of solar electricity. In partnership with the Oregon Military Department, the Department of Energy used the award to assess and evaluate renewable resources in a 2,622-acre location in Lake County, central Oregon, leading to future development of up to 200 MW of solar electricity. The Oregon Military Department (Military) acquired a large parcel of land located in south central Oregon. The land was previously owned by the US Air Force and developed for an Over-the-Horizon Backscatter Radar Transmitter Facility, located about 10 miles east of the town of Christmas Valley. The Military is investigating a number of uses for the site, including Research and Development (R&D) laboratory, emergency response, military operations, developing renewable energy and related educational programs. One of the key potential uses would be for a large scale solar photovoltaic power plant. This is an attractive use because the site has excellent solar exposure; an existing strong electrical interconnection to the power grid; and a secure location at a moderate cost per acre. The project objectives include: 1. Site evaluation 2. Research and Development (R&D) facility analysis 3. Utility interconnection studies and agreements 4. Additional on-site renewable energy resources analysis 5. Community education, outreach and mitigation 6. Renewable energy and emergency readiness training program for veterans

  7. Geothermal development. Semi-annual report, October 1, 1980-March 31, 1981

    Energy Technology Data Exchange (ETDEWEB)

    1981-03-31

    Three areas are reported: geothermal administration, geothermal planning, and other geothermal activities. Administration covers the status of the Imperial Valley Environmental Project transfer, update of the Geothermal Resource Center, and findings of the geothermal field inspections. Planning addresses Board of Supervisor actions, Planning Commission actions, notice of exemptions, and the master Environmental Impact Report for Salton Sea. The other activity includes the County Direct Heat Development study; the solicitation for district heating and cooling proposals; the new Geothermal Class II-1 disposal site; the DOE Region IX meeting in Tucson; and USGA designating a new KGRA, the East Brawley KGRA, the Westmoreland KGRA, and revising the southern border of the Salton Sea KGRA. (MHR)

  8. Fjord-valley fill stratigraphy from onshore high-resolution shear-wave seismics, Trondheim harbour area, central Norway

    Science.gov (United States)

    Hansen, L.; Polom, U.; L'Heureux, J.; Sauvin, G.; Lecomte, I.; Krawczyk, C. M.; Longva, O.

    2009-12-01

    To obtain information on the stratigraphic variability within the underlying fjord-valley fill, a shallow, shear-wave reflection seismic survey was successfully carried out on land in the Trondheim harbor area, central Norway. Since the last deglaciation, the region has been subjected to a fall of relative sea level of totally 175 m due to glacioisostatic rebound. The relative sea-level fall was accompanied by river erosion of emerging (glacio) marine deposits, several, large landslides, and delta progradation into the fjord. The infilled harbour area is located on the submerged part of a delta plain, and land reclamation is still going on. Historic and older submarine landslides are known to have taken place along the shoreline and an improved understanding of the ground conditions is therefore valuable for engineering purposes. In addition, the unique, S-wave seismic record gives insight into the overall architecture and long-term development of a fjord-valley filling influenced by relative sea level fall accompanied by occasional major mass-wasting events. Shear-wave reflection seismics was applied using a land streamer of 120 channels combined with a newly developed shear-wave vibrator from LIAG. Overall, 4.2 profile-km were acquired in a 2.5-D grid along paved roads and parking lots during night to minimize environmental noise. The investigations achieved a highly resolved image of the fjord-valley fill and clear bedrock detection. Vertical resolution is within a few meters over the entire profile whereas horizontal resolution decreases with depth. The entire fjord-valley fill is up to 160 m thick and five main stratigraphic units have been identified including bedrock. The fjord-valley fill is interpreted as consisting of glaciomarine deposits overlain by marine fjord sediments grading upwards into deltaic deposits. The change from continuous to more discontinuous or irregular reflection patterns reflects a progressive influence of delta-derived processes and

  9. Mammals of the Sea.

    Science.gov (United States)

    Naturescope, 1986

    1986-01-01

    Presents information on sea mammals, including definitions and characteristics of cetaceans, pinnipeds, and sirenians. Contains descriptions of the teaching activities "Whale Music,""Draw A Whale to Scale,""Adopt a Sea Mammal," and "Sea Mammal Sleuths." (TW)

  10. Measured compaction for 24 extensometers in the Central Valley

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset contains the compaction data for 24 extensometers used for observations in the Central Valley Hydrologic Model (CVHM). The Central Valley...

  11. Evapotranspiration Input Data for the Central Valley Hydrologic Model (CVHM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset contains monthly reference evapotranspiration (ETo) data for the Central Valley Hydrologic Model (CVHM). The Central Valley encompasses an...

  12. Goldstone-Apple Valley Radio Telescope System Theory of Operation

    Science.gov (United States)

    Stephan, George R.

    1997-01-01

    The purpose of this learning module is to enable learners to describe how the Goldstone-Apple Valley Radio Telescope (GAVRT) system functions in support of Apple Valley Science and Technology Center's (AVSTC) client schools' radio astronomy activities.

  13. Radon in water of Shu river valley

    Directory of Open Access Journals (Sweden)

    Yelena Kuyanova

    2012-03-01

    Full Text Available The values of radon and its daughter products in water of Shu River valley have been received, using liquid scintillation spectrometry. The radon concentration naturally increases in investigated water samples downstream the Shu River, reaching the maximum value in the Tashutkolsky basin. The radon and its daughter products in a human body of 15 % are in soft tissues have been calculated by a mathematical modeling method. The annual dose from radon and its daughter products calculated by a mathematical modeling method received by the residents living in Shu river valley is 0,03 mSv/year.

  14. The Health Valley: Global Entrepreneurial Dynamics.

    Science.gov (United States)

    Dubuis, Benoit

    2014-12-01

    In the space of a decade, the Lake Geneva region has become the Health Valley, a world-class laboratory for discovering and developing healthcare of the future. Through visionary individuals and thanks to exceptional infrastructure this region has become one of the most dynamic in the field of innovation, including leading scientific research and exceptional actors for the commercialization of academic innovation to industrial applications that will improve the lives of patients and their families. Here follows the chronicle of a spectacular expansion into the Health Valley.

  15. Advanced seismic imaging of overdeepened alpine valleys

    Science.gov (United States)

    Burschil, Thomas; Buness, Hermann; Tanner, David; Gabriel, Gerald; Krawczyk, Charlotte M.

    2017-04-01

    Major European alpine valleys and basins are densely populated areas with infrastructure of international importance. To protect the environment by, e.g., geohazard assessment or groundwater estimation, understanding of the geological structure of these valleys is essential. The shape and deposits of a valley can clarify its genesis and allows a prediction of behaviour in future glaciations. The term "overdeepened" refers to valleys and basins, in which pressurized melt-water under the glacier erodes the valley below the fluvial level. Most overdeepened valleys or basins were thus refilled during the ice melt or remain in the form of lakes. The ICDP-project Drilling Overdeepened Alpine Valleys (DOVE) intends to correlate the sedimentary succession from boreholes between valleys in the entire alpine range. Hereby, seismic exploration is essential to predict the most promising well path and drilling site. In a first step, this DFG-funded project investigates the benefit of multi-component techniques for seismic imaging. At two test sites, the Tannwald Basin and the Lienz Basin, the Leibniz Institute for Applied Geophysics acquired P-wave reflection profiles to gain structural and facies information. Built on the P-wave information, several S-wave reflection profiles were acquired in the pure SH-wave domain as well as 6-C reflection profiles using a horizontal S-wave source in inline and crossline excitation and 3-C receivers. Five P-wave sections reveal the structure of the Tannwald Basin, which is a distal branch basin of the Rhine Glacier. Strong reflections mark the base of the basin, which has a maximum depth of 240 metres. Internal structures and facies vary strongly and spatially, but allow a seismic facies characterization. We distinguish lacustrine, glacio-fluvial, and deltaic deposits, which make up the fill of the Tannwald Basin. Elements of the SH-wave and 6-C seismic imaging correlate with major structures in the P-wave image, but vary in detail. Based on

  16. Clean Cities Award Winning Coalition: Coachella Valley

    Energy Technology Data Exchange (ETDEWEB)

    ICF Kaiser

    1999-05-20

    Southern California's Coachella Valley became a Clean Cities region in 1996. Since then, they've made great strides. SunLine Transit, the regional public transit provider, was the first transit provider to replace its entire fleet with compressed natural gas buses. They've also built the foundation for a nationally recognized model in the clean air movement, by partnering with Southern California Gas Company to install a refueling station and developing a curriculum for AFV maintenance with the College of the Desert. Today the valley is home to more than 275 AFVs and 15 refueling stations.

  17. Molecular Epidemiology of Rift Valley Fever Virus

    Science.gov (United States)

    Grobbelaar, Antoinette A.; Weyer, Jacqueline; Leman, Patricia A.; Kemp, Alan; Paweska, Janusz T.

    2011-01-01

    Phylogenetic relationships were examined for 198 Rift Valley fever virus isolates and 5 derived strains obtained from various sources in Saudi Arabia and 16 countries in Africa during a 67-year period (1944–2010). A maximum-likelihood tree prepared with sequence data for a 490-nt section of the Gn glycoprotein gene showed that 95 unique sequences sorted into 15 lineages. A 2010 isolate from a patient in South Africa potentially exposed to co-infection with live animal vaccine and wild virus was a reassortant. The potential influence of large-scale use of live animal vaccine on evolution of Rift Valley fever virus is discussed. PMID:22172568

  18. Geothermal resource investigations, Imperial Valley, California. Status report

    Energy Technology Data Exchange (ETDEWEB)

    1971-04-01

    The discussion is presented under the following chapter titles: geothermal resource investigations, Imperial Valley, California; the source of geothermal heat; status of geothermal resources (worldwide); geothermal aspects of Imperial Valley, California; potential geothermal development in Imperial Valley; environmental considerations; and proposed plan for development. (JGB)

  19. Sea Level Acceleration in the China Seas

    OpenAIRE

    Yongcun Cheng; Tal Ezer; Hamlington, Benjamin D.

    2016-01-01

    While global mean sea level rise (SLR) and acceleration (SLA) are indicators of climate change and are informative regarding the current state of the climate, assessments of regional and local SLR are essential for policy makers responding to, and preparing for, changes in sea level. In this work, three acceleration detection techniques are used to demonstrate the robust SLA in the China Seas. Interannual to multidecadal sea level variations (periods >2 years), which are mainly related to ...

  20. Observation of acoustic valley vortex states and valley-chirality locked beam splitting

    Science.gov (United States)

    Ye, Liping; Qiu, Chunyin; Lu, Jiuyang; Wen, Xinhua; Shen, Yuanyuan; Ke, Manzhu; Zhang, Fan; Liu, Zhengyou

    2017-05-01

    We report an experimental observation of the classical version of valley polarized states in a two-dimensional hexagonal sonic crystal. The acoustic valley states, which carry specific linear momenta and orbital angular momenta, were selectively excited by external Gaussian beams and conveniently confirmed by the pressure distribution outside the crystal, according to the criterion of momentum conservation. The vortex nature of such intriguing bulk crystal states was directly characterized by scanning the phase profile inside the crystal. In addition, we observed a peculiar beam-splitting phenomenon, in which the separated beams are constructed by different valleys and locked to the opposite vortex chirality. The exceptional sound transport, encoded with valley-chirality locked information, may serve as the basis of designing conceptually interesting acoustic devices with unconventional functions.

  1. 77 FR 33237 - Saline Valley Warm Springs Management Plan/Environmental Impact Statement, Death Valley National...

    Science.gov (United States)

    2012-06-05

    ... resources within this remote area, many people associate Saline Valley only with Warm Springs. Since the... by partnerships between the NPS and the Tribe. As a consequence of conflicting perceptions and values...

  2. College in Paradise! (Paradise Valley Shopping Mall).

    Science.gov (United States)

    Schoolland, Lucile B.

    Rio Salado Community College (RSCC), a non-campus college within the Maricopa Community College District, offers hundreds of day, late afternoon, and evening classes at locations throughout the county. The Paradise Valley community had always participated heavily in the evening classes offered by RSCC at local high schools. In fall 1982, an effort…

  3. Businessman's Efforts Help Reinvent Valley Tech

    Science.gov (United States)

    Pedersen, Diane B.

    2007-01-01

    Machine shop and metal fabrication programs across the country have struggled since the mid-1980s when the rise in global competition resulted in more manufacturing jobs going overseas. Blackstone Valley Regional Vocational Technical High School in Upton, Massachusetts, was able to keep its program up and running due in large part to its…

  4. Babesiosis in Lower Hudson Valley, New York

    Centers for Disease Control (CDC) Podcasts

    2011-05-12

    This podcast discusses a study about an increase in babesiosis in the Lower Hudson Valley of New York state. Dr. Julie Joseph, Assistant Professor of Medicine at New York Medical College, shares details of this study.  Created: 5/12/2011 by National Center for Emerging Zoonotic and Infectious Diseases (NCEZID).   Date Released: 5/23/2011.

  5. 27 CFR 9.103 - Mimbres Valley.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Mimbres Valley. 9.103 Section 9.103 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT... Counties, New Mexico. The boundaries are as follows: The beginning point is located at Faywood Station on...

  6. 27 CFR 9.23 - Napa Valley.

    Science.gov (United States)

    2010-04-01

    ... Valley viticultural area is located within Napa County, California. From the beginning point at the conjuction of the Napa County-Sonoma County line and the Napa County-Lake County line, the boundary runs along— (1) The Napa County-Lake County line; (2) Putah Creek and the western and southern shores of Lake...

  7. 27 CFR 9.76 - Knights Valley.

    Science.gov (United States)

    2010-04-01

    ... Valley viticultural area is located in northeastern Sonoma County, California. From the beginning point lying at the intersection of the Sonoma/Lake County line and the north line of Section 11, Township 10...,” and “Mount St. Helena Quadrangle” maps to the point of intersection with the Lake County line on the...

  8. Business plan Hatchery Facility Zambezi Valley, Mozambique

    NARCIS (Netherlands)

    Vernooij, A.G.; Wilschut, S.

    2015-01-01

    This business plan focuses on the establishment of a hatchery, one of the essential elements of a sustainable and profitable poultry meat value chain. There is a growing demand for poultry meat in the Zambezi Valley, and currently a large part of the consumed broilers comes from other parts of the

  9. Range management research, Fort Valley Experimental Forest

    Science.gov (United States)

    Henry A. Pearson; Warren P. Clary; Margaret M. Moore; Carolyn Hull Sieg

    2008-01-01

    Range management research at the Fort Valley Experimental Forest during the past 100 years has provided scientific knowledge for managing ponderosa pine forests and forest-range grazing lands in the Southwest. Three research time periods are identified: 1908 to 1950, 1950 to 1978, and 1978 to 2008. Early research (1908-1950) addressed ecological effects of livestock...

  10. Poultry Slaughter facility Zambezi Valley, Mozambique

    NARCIS (Netherlands)

    Vernooij, A.G.; Wilschut, S.

    2015-01-01

    This business plan focuses on the establishment of a slaughterhouse, one of the essential elements of a sustainable and profitable poultry meat value chain. There is a growing demand for poultry meat in the Zambezi Valley, and currently a large part of the consumed broilers comes from other parts of

  11. Rift Valley fever: A neglected zoonotic disease?

    Science.gov (United States)

    Rift Valley fever (RVF) is a serious viral disease of animals and humans in Africa and the Middle East that is transmitted by mosquitoes. First isolated in Kenya during an outbreak in 1930, subsequent outbreaks have had a significant impact on animal and human health, as well as national economies. ...

  12. Pumpernickel Valley Geothermal Project Thermal Gradient Wells

    Energy Technology Data Exchange (ETDEWEB)

    Z. Adam Szybinski

    2006-01-01

    The Pumpernickel Valley geothermal project area is located near the eastern edge of the Sonoma Range and is positioned within the structurally complex Winnemucca fold and thrust belt of north-central Nevada. A series of approximately north-northeast-striking faults related to the Basin and Range tectonics are superimposed on the earlier structures within the project area, and are responsible for the final overall geometry and distribution of the pre-existing structural features on the property. Two of these faults, the Pumpernickel Valley fault and Edna Mountain fault, are range-bounding and display numerous characteristics typical of strike-slip fault systems. These characteristics, when combined with geophysical data from Shore (2005), indicate the presence of a pull-apart basin, formed within the releasing bend of the Pumpernickel Valley – Edna Mountain fault system. A substantial body of evidence exists, in the form of available geothermal, geological and geophysical information, to suggest that the property and the pull-apart basin host a structurally controlled, extensive geothermal field. The most evident manifestations of the geothermal activity in the valley are two areas with hot springs, seepages, and wet ground/vegetation anomalies near the Pumpernickel Valley fault, which indicate that the fault focuses the fluid up-flow. There has not been any geothermal production from the Pumpernickel Valley area, but it was the focus of a limited exploration effort by Magma Power Company. In 1974, the company drilled one exploration/temperature gradient borehole east of the Pumpernickel Valley fault and recorded a thermal gradient of 160oC/km. The 1982 temperature data from five unrelated mineral exploration holes to the north of the Magma well indicated geothermal gradients in a range from 66 to 249oC/km for wells west of the fault, and ~283oC/km in a well next to the fault. In 2005, Nevada Geothermal Power Company drilled four geothermal gradient wells, PVTG-1

  13. Geomorphology of outflow part Batova river valley

    Science.gov (United States)

    Vulcheva-Georgieva, Ivalena; Stankova, Svetla

    2017-03-01

    Firths are geomoiphological and hydrological sites typical for flat, neutral coast of no tidal sea basins. There in the greatest extend is preserved the geological column of the correlative Pleistocene- Holocene sediments. They make possible to reveal the Quaternary evolution of the contact zone "land-sea". Firths are one of the most reliable indicators for the Quaternary Earth crust movements. Along the Black Sea coast most widely are developed the firths in the north - west and the west periphery, where they form a classic firth type coast. This report examines the results of complex studies of Batova river firth, located (developed) on the North Bulgarian Black Sea coast.

  14. A valley-filtering switch based on strained graphene.

    Science.gov (United States)

    Zhai, Feng; Ma, Yanling; Zhang, Ying-Tao

    2011-09-28

    We investigate valley-dependent transport through a graphene sheet modulated by both the substrate strain and the fringe field of two parallel ferromagnetic metal (FM) stripes. When the magnetizations of the two FM stripes are switched from the parallel to the antiparallel alignment, the total conductance, valley polarization and valley conductance excess change greatly over a wide range of Fermi energy, which results from the dependence of the valley-related transmission suppression on the polarity configuration of inhomogeneous magnetic fields. Thus the proposed structure exhibits the significant features of a valley-filtering switch and a magnetoresistance device.

  15. Hydrogeochemical investigation of groundwater in Jericho area in the Jordan Valley, West Bank, Palestine

    Science.gov (United States)

    Da'as, Ammar; Walraevens, Kristine

    2013-06-01

    Water resources in the Middle East, particularly in Palestine, are extremely scarce and costly. The Jordan Valley is a fertile productive region, described as the food basket of Palestine. Groundwater originating from the Quaternary Aquifer System forms the main water resource in the Jordan Valley. However, the quality of this groundwater is threatened mainly by the high chloride concentration. The most representative area of the Jordan Valley is Jericho area, which was chosen to be the study area. The study area (65 km2) is almost a flat area with a gentle decline towards the east. It is the lowest land on earth with ground levels reaching 400 meters below sea level (mbsl) near the Dead Sea shores. The Quaternary Aquifer System in the study area could be divided into an upper alluvial layer with thickness varying from 40 to 150 m and a lower low-permeable Lisan layer, which crops out in the eastern part of the study area with thickness over 200 m. Hydrogeochemical investigation reveals that the water is generally earth alkaline with higher content of earth alkalis and prevailing chloride. According to Stuyfzand (1986) and Piper's (1944) classification systems, water type in the Alluvial Aquifer varies from fresh hard CaMgHCO3 or MgCaHCO3 water in the west and northwest to brackish very-hard MgNaCl or NaMgCl in the middle. In the east, the water becomes brackish-salt extremely-hard MgNaCl or NaCl. Groundwater quality is deteriorating (increase in salinity) spatially towards the east and vertically with increasing depth (when nearing the Lisan Formation). As an indication of groundwater salinity, total dissolved solids show some variability with time over the last 21 years (1983-2004). In short-time scale, there are high seasonal and yearly fluctuations with regard to salinity, specifically in Cl- and SO42- contents. Spring water from the Upper Cenomanian Aquifer (CaHCO3) represents the fresh end member, while Rift Valley Brines (RVB-CaNaCl) and Dead Sea Brines (DSB

  16. Punctuated Sediment Discharge during Early Pliocene Birth of the Colorado River: Evidence from Regional Stratigraphy, Sedimentology, and Paleontology

    Science.gov (United States)

    Dorsey, Rebecca J.; O'Connell, Brennan; McDougall, Kristin; Homan, Mindy B.

    2018-01-01

    The Colorado River in the southwestern U.S. provides an excellent natural laboratory for studying the origins of a continent-scale river system, because deposits that formed prior to and during river initiation are well exposed in the lower river valley and nearby basinal sink. This paper presents a synthesis of regional stratigraphy, sedimentology, and micropaleontology from the southern Bouse Formation and similar-age deposits in the western Salton Trough, which we use to interpret processes that controlled the birth and early evolution of the Colorado River. The southern Bouse Formation is divided into three laterally persistent members: basal carbonate, siliciclastic, and upper bioclastic members. Basal carbonate accumulated in a tide-dominated marine embayment during a rise of relative sea level between 6.3 and 5.4 Ma, prior to arrival of the Colorado River. The transition to green claystone records initial rapid influx of river water and its distal clay wash load into the subtidal marine embayment at 5.4-5.3 Ma. This was followed by rapid southward progradation of the Colorado River delta, establishment of the earliest through-flowing river, and deposition of river-derived turbidites in the western Salton Trough (Wind Caves paleocanyon) between 5.3 and 5.1 Ma. Early delta progradation was followed by regional shut-down of river sand output between 5.1 and 4.8 Ma that resulted in deposition of marine clay in the Salton Trough, retreat of the delta, and re-flooding of the lower river valley by shallow marine water that deposited the Bouse upper bioclastic member. Resumption of sediment discharge at 4.8 Ma drove massive progradation of fluvial-deltaic deposits back down the river valley into the northern Gulf and Salton Trough. These results provide evidence for a discontinuous, start-stop-start history of sand output during initiation of the Colorado River that is not predicted by existing models for this system. The underlying controls on punctuated sediment

  17. Punctuated sediment discharge during early Pliocene birth of the Colorado River: Evidence from regional stratigraphy, sedimentology, and paleontology

    Science.gov (United States)

    Dorsey, Rebecca J.; O’Connell, Brennan; McDougall-Reid, Kristin; Homan, Mindy B.

    2018-01-01

    The Colorado River in the southwestern U.S. provides an excellent natural laboratory for studying the origins of a continent-scale river system, because deposits that formed prior to and during river initiation are well exposed in the lower river valley and nearby basinal sink. This paper presents a synthesis of regional stratigraphy, sedimentology, and micropaleontology from the southern Bouse Formation and similar-age deposits in the western Salton Trough, which we use to interpret processes that controlled the birth and early evolution of the Colorado River. The southern Bouse Formation is divided into three laterally persistent members: basal carbonate, siliciclastic, and upper bioclastic members. Basal carbonate accumulated in a tide-dominated marine embayment during a rise of relative sea level between ~ 6.3 and 5.4 Ma, prior to arrival of the Colorado River. The transition to green claystone records initial rapid influx of river water and its distal clay wash load into the subtidal marine embayment at ~ 5.4–5.3 Ma. This was followed by rapid southward progradation of the Colorado River delta, establishment of the earliest through-flowing river, and deposition of river-derived turbidites in the western Salton Trough (Wind Caves paleocanyon) between ~ 5.3 and 5.1 Ma. Early delta progradation was followed by regional shut-down of river sand output between ~ 5.1 and 4.8 Ma that resulted in deposition of marine clay in the Salton Trough, retreat of the delta, and re-flooding of the lower river valley by shallow marine water that deposited the Bouse upper bioclastic member. Resumption of sediment discharge at ~ 4.8 Ma drove massive progradation of fluvial-deltaic deposits back down the river valley into the northern Gulf and Salton Trough.These results provide evidence for a discontinuous, start-stop-start history of sand output during initiation of the Colorado River that is not predicted by existing models for this system. The underlying controls on

  18. Campaigned GPS on Present-Day Crustal Deformation in Northernmost Longitudinal Valley Preliminary Results, Hualien Taiwan

    Directory of Open Access Journals (Sweden)

    Chia-Yu Chen

    2014-01-01

    Full Text Available The Longitudinal Valley in Eastern Taiwan sits at the collision suture between the Eurasian and Philippine Sea plates. Based on repeated GPS campaigned measurements from 25 stations six times in 2007 - 2009, we characterize the surface deformation in the northernmost Longitudinal Valley where the Coastal Range of the Philippine Sea plate turns northward diving under the Eurasian plate producing two major active faults: the Milun fault and the Longitudinal Valley fault. We reconstructed a GPS velocity field and conducted strain analyses and elastic block modeling. Our results suggest a rapid clockwise rotation of 33° Myr-1 and an eastward tectonic escape in the small Hualien City block (HUAL area of ~10 × 10 km, which is apparently detached from the regional rotating RYUK block defined by previous studies. We interpret it as being initiated locally by the northwest indentation of the Coastal Range, which pushed the HUAL block to move upward and eastward. According to our strain analyses, the HUAL block shows a significant internal elastic strain inside the Milun Tableland, the hanging wall of the Milun fault. No significant deformation was observed across the surface trace of the fault, indicating that the Milun fault is now probably locked in the near surface. The deformation in the footwall of the fault was accommodated by pure-shear strain with a major NNW-compression and a minor ENE-extension. The deformation in the hanging wall is characterized by simple-shear strain with ENE-extension in its northern part and little deformation in the southern part, separated by a little known NW-trending active fault zone (Dongmingyi fault, which needs further investigation.

  19. Groundwater quality in the Owens Valley, California

    Science.gov (United States)

    Dawson, Barbara J. Milby; Belitz, Kenneth

    2012-01-01

    Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created 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. Owens Valley is one of the study areas being evaluated. The Owens study area is approximately 1,030 square miles (2,668 square kilometers) and includes the Owens Valley groundwater basin (California Department of Water Resources, 2003). Owens Valley has a semiarid to arid climate, with average annual rainfall of about 6 inches (15 centimeters). The study area has internal drainage, with runoff primarily from the Sierra Nevada draining east to the Owens River, which flows south to Owens Lake dry lakebed at the southern end of the valley. Beginning in the early 1900s, the City of Los Angeles began diverting the flow of the Owens River to the Los Angeles Aqueduct, resulting in the evaporation of Owens Lake and the formation of the current Owens Lake dry lakebed. Land use in the study area is approximately 94 percent (%) natural, 5% agricultural, and 1% urban. The primary natural land cover is shrubland. The largest urban area is the city of Bishop (2010 population of 4,000). Groundwater in this basin is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from surrounding mountains. Recharge to the groundwater system is primarily runoff from the Sierra Nevada, and by direct infiltration of irrigation. The primary sources of discharge are pumping wells, evapotranspiration, and underflow to the Owens Lake dry lakebed. The primary aquifers in Owens Valley are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database

  20. Eco-Hydrological Modelling of Stream Valleys

    DEFF Research Database (Denmark)

    Johansen, Ole

    Predicting the effects of hydrological alterations on terrestrial stream valley ecosystems requires multidisciplinary approaches involving both engineers and ecologists. Groundwater discharge in stream valleys and other lowland areas support a number of species rich ecosystems, and their protection...... is prioritised worldwide. Protection requires improved knowledge on the functioning of these ecosystems and especially the linkages between vegetation, groundwater discharge and water level conditions are crucial for management applications. Groundwater abstraction affects catchment hydrology and thereby also...... groundwater discharge. Numerical hydrological modelling has been widely used for evaluation of sustainable groundwater resources and effects of abstraction, however, the importance of local scale heterogeneity becomes increasingly important in the assessment of local damage to these groundwater dependent...

  1. Hydrogeochemical assessment of groundwater in Kashmir Valley ...

    Indian Academy of Sciences (India)

    Hydrogeochemical assessment of groundwater in Kashmir Valley, India. 1033. Figure 1. Geology of the study area and the location of sampling sites. 4. Results and discussion ..... 1036. G H Jeelani et al. F ig u re. 2 . Spa tia l v a ria tio n o f m a jo r io ns in g ro undw a ter a cro ss the a llu via l ba sin o f the. Ka sh mir. V a lley.

  2. 27 CFR 9.35 - Edna Valley.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Edna Valley. 9.35 Section 9.35 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF... identified as “T31S/T32S” on the U.S.G.S. map; (4) Thence east along township line “T31S/T32S”, across Price...

  3. Flood Frequency Analysis of Main Nara Valley

    OpenAIRE

    Manohar Lal; Bakhshal Khan Lashari; Khalifa Qasim Laghari

    2011-01-01

    This paper deals with the flood of 2007 and its frequency analysis at MNY (Main Nara Valley), and generally describe flood of 2010 in Sindh Pakistan. Heavy monsoon rain and cyclones cause the flood conditions in Sindh. The damages happened to the infrastructure of the MNVD from RD (Reduced Distance) 0-100 and the ecological impacts of the flood on the local region of Taluka Johi, District Dadu. For flood risk assessment and its description, knowledge of extreme flood events and...

  4. Willamette Valley Ecoregion: Chapter 3 in Status and trends of land change in the Western United States--1973 to 2000

    Science.gov (United States)

    Wilson, Tamara S.; Sorenson, Daniel G.

    2012-01-01

    The Willamette Valley Ecoregion (as defined by Omernik, 1987; U.S. Environmental Protection Agency, 1997) covers approximately 14,458 km² (5,582 mi2), making it one of the smallest ecoregions in the conterminous United States. The long, alluvial Willamette Valley, which stretches north to south more than 193 km and ranges from 32 to 64 km wide, is nestled between the sedimentary and metamorphic Coast Ranges (Coast Range Ecoregion) to the west and the basaltic Cascade Range (Cascades Ecoregion) to the east (fig. 1). The Lewis and Columbia Rivers converge at the ecoregion’s northern boundary in Washington state; however, the majority of the ecoregion falls within northwestern Oregon. Interstate 5 runs the length of the valley to its southern boundary with the Klamath Mountains Ecoregion. Topography here is relatively flat, with elevations ranging from sea level to 122 m. This even terrain, coupled with mild, wet winters, warm, dry summers, and nutrient-rich soil, makes the Willamette Valley the most important agricultural region in Oregon. Population centers are concentrated along the valley floor. According to estimates from the Oregon Department of Fish and Wildlife (2006), over 2.3 million people lived in Willamette Valley in 2000. Portland, Oregon, is the largest city, with 529,121 residents (U.S. Census Bureau, 2000). Other sizable cities include Eugene, Oregon; Salem (Oregon’s state capital); and Vancouver, Washington. Despite the large urban areas dotting the length of the Willamette Valley Ecoregion, agriculture and forestry products are its economic foundation (figs. 2,3). The valley is a major producer of grass seed, ornamental plants, fruits, nuts, vegetables, and grains, as well as poultry, beef, and dairy products. The forestry and logging industries also are primary employers of the valley’s rural residents (Rooney, 2008). These activities have affected the watershed significantly, with forestry and agricultural runoff contributing to river

  5. Imperial County geothermal development. Quarterly report, April 1, 1980-June 30, 1981

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    Three areas are reported: Geothermal Administration, Geothermal Planning; and other Geothermal Activities. Geothermal Administration addresses the status of the Imperial Valley Environmental Project (IVEP) transfer, update of the Geothermal Resource Center, and findings of Geothermal field inspections. Field inspections will cover the four new wells drilled by Magma at the Salton Sea in preparation for 28 MW power plant, the progress at Sperry at East Mesa, and the two on-line power plants in East Mesa and North Brawley. Evaluation of cooperative efforts will cover the Geothermal Subsidence Detection Network Resurvey, Master EIR for the Salton Sea and the Annual Imperial County Geothermal meeting. The status of Geothermal development throughout the County will cover existing proposed facilities. The summary of the Geothermal meeting (Appendix A) will also provide the status of several projects. Geothermal Planning addresses the EIR Notice of Exemption from CEQA, progress on the Master EIR for the Salton Sea, and the EIR for Phillips Petroleum for 6 exploratory wells in the Truckhaven area. Other Geothermal Activity addresses the Department of Energy Region IX meeting hosted by Imperial County, the Annual Imperial County Geothermal meeting, Class II-1 geothermal hazardous waste disposal siting study, and Imperial County Geothermal Direct Heat Study.

  6. Remote Sensing Contributions to Prediction and Risk Assessment of Natural Disasters Caused by Large Scale Rift Valley Fever Outbreaks

    Science.gov (United States)

    Anyamba, Assaf; Linthicum, Kenneth J.; Small, Jennifer; Britch, S. C.; Tucker, C. J.

    2012-01-01

    Remotely sensed vegetation measurements for the last 30 years combined with other climate data sets such as rainfall and sea surface temperatures have come to play an important role in the study of the ecology of arthropod-borne diseases. We show that epidemics and epizootics of previously unpredictable Rift Valley fever are directly influenced by large scale flooding associated with the El Ni o/Southern Oscillation. This flooding affects the ecology of disease transmitting arthropod vectors through vegetation development and other bioclimatic factors. This information is now utilized to monitor, model, and map areas of potential Rift Valley fever outbreaks and is used as an early warning system for risk reduction of outbreaks to human and animal health, trade, and associated economic impacts. The continuation of such satellite measurements is critical to anticipating, preventing, and managing disease epidemics and epizootics and other climate-related disasters.

  7. Optical manipulation of valley pseduospin in 2D semiconductors

    Science.gov (United States)

    Ye, Ziliang

    Valley polarization associated with the occupancy in the energy degenerate but quantum mechanically distinct valleys in the momentum space closely resembles spin polarization and has been proposed as a pseudospin carrier for future quantum information technologies. Monolayers of transition metal dichalcogenide (TMDC) crystals, with broken inversion symmetry and large spin-orbital coupling, support robust valley polarization and therefore provide an important platform for studying valley-dependent physics. Besides optical excitation and photoluminescence detection, valley polarization has been electrically measured through the valley Hall effect and created through spin injection from ferromagnetic semiconductor contacts. Moreover, the energy degeneracy of the valley degree of freedom has been lifted by the optical Stark effect. Recently, we have demonstrated optical manipulation of valley coherence, i.e., of the valley pseudospin, by the optical Stark effect in monolayer WSe2. Using below-bandgap circularly polarized light, we rotated the valley pseudospin on the femtosecond time scale. Both the direction and speed of the rotation can be optically controlled by tuning the dynamic phase of excitons in opposite valleys. The pseudospin rotation was identified by changes in the polarization of the photoluminescence. In addition, by varying the time delay between the excitation and control pulses, we directly probed the lifetime of the intervalley coherence. Similar rotation levels have also been observed in static magneto-optic experiments. Our work presents an important step towards the full control of the valley degree of freedom in 2D semiconductors. The work was done in collaboration with Dr. Dezheng Sun and Prof. Tony F. Heinz.

  8. Hydrologic reconnaissance of Rush Valley, Tooele County, Utah

    Science.gov (United States)

    Hood, James W.; Price, Don; Waddell, K.M.

    1969-01-01

    This report is the third in a series by the U. S. Geological Survey in cooperation with the Utah Department of Natural Resources, Division of Water Rights, which describes the water resources of the western basins of Utah. Its purpose is to present available hydrologic data for Rush Valley, to provide an evaluation of the potential water-resources development of the valley, and to identify needed studies that would help provide an understanding of the valley's water supply.

  9. Hydrologic reconnaissance of Skull Valley, Tooele County, Utah

    Science.gov (United States)

    Hood, James W.; Waddell, K.M.

    1968-01-01

    This report is the second in a series by the U.S. Geological Survey in cooperation with the Utah Department of Natural Resources, Division of Water Rights, which describes the water resources of the western basins of Utah. Its purpose is to present available hydrologic data on Skull Valley, to provide an evaluation of the potential water-resource development of the valley, and to identify needed studies that would help provide an understandingof the valley's water supply.

  10. Sea Turtle Interaction Report

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Sea Turtle Interaction Report is a report sent out in pdf format to authorized individuals that summarizes sea turtle interactions in the longline fishery. The...

  11. Sea Lion Diet Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — California sea lions pup and breed at four of the nine Channel Islands in southern California. Since 1981, SWFSC MMTD has been conducting a diet study of sea lions...

  12. Sources, trends and regional impacts of fine particulate matter in southern Mississippi valley: significance of emissions from sources in the Gulf of Mexico coast

    OpenAIRE

    Chalbot, M.-C.; McElroy, B.; I. G. Kavouras

    2013-01-01

    The sources of fine particles over a 10 yr period at Little Rock, Arkansas, an urban area in the southern Mississippi Valley, were identified by positive matrix factorization. The annual trends of PM2.5 and its sources, and their associations with the pathways of air mass backward trajectories were examined. Seven sources were apportioned, namely, primary traffic particles, secondary nitrate and sulphate, biomass burning, diesel particles, aged/contaminated sea salt and mine...

  13. Sources, trends and regional impacts of fine particulate matter in southern Mississippi Valley: significance of emissions from sources in the Gulf of Mexico coast

    OpenAIRE

    M.-C. Chalbot; McElroy, B.; I. G. Kavouras

    2013-01-01

    The sources of fine particles over a 10 yr period at Little Rock, Arkansas, an urban area in southern Mississippi Valley, were identified by positive matrix factorization. The annual trends of PM2.5 and its sources and their associations with the pathways of air mass backward trajectories were examined. Seven sources were apportioned, namely, primary traffic particles, secondary nitrate and sulphate, biomass burning, diesel particles, aged/contaminated sea salt a...

  14. Prediction, Assessment of the Rift Valley Fever Activity in East and Southern Africa 2006–2008 and Possible Vector Control Strategies

    OpenAIRE

    Anyamba, Assaf; Kenneth J Linthicum; Small, Jennifer; Britch, Seth C.; Pak, Edwin; de La Rocque, Stephane; Formenty, Pierre; Hightower, Allen W.; Robert F Breiman; Chretien, Jean-Paul; Compton J Tucker; Schnabel, David; Sang, Rosemary; Haagsma, Karl; Latham, Mark

    2010-01-01

    Historical outbreaks of Rift Valley fever (RVF) since the early 1950s have been associated with cyclical patterns of the El Niño/Southern Oscillation (ENSO) phenomenon, which results in elevated and widespread rainfall over the RVF endemic areas of Africa. Using satellite measurements of global and regional elevated sea surface temperatures, elevated rainfall, and satellite derived-normalized difference vegetation index data, we predicted with lead times of 2–4 months areas where outbreaks of...

  15. Spatially resolving valley quantum interference of a donor in silicon.

    Science.gov (United States)

    Salfi, J; Mol, J A; Rahman, R; Klimeck, G; Simmons, M Y; Hollenberg, L C L; Rogge, S

    2014-06-01

    Electron and nuclear spins of donor ensembles in isotopically pure silicon experience a vacuum-like environment, giving them extraordinary coherence. However, in contrast to a real vacuum, electrons in silicon occupy quantum superpositions of valleys in momentum space. Addressable single-qubit and two-qubit operations in silicon require that qubits are placed near interfaces, modifying the valley degrees of freedom associated with these quantum superpositions and strongly influencing qubit relaxation and exchange processes. Yet to date, spectroscopic measurements have only probed wavefunctions indirectly, preventing direct experimental access to valley population, donor position and environment. Here we directly probe the probability density of single quantum states of individual subsurface donors, in real space and reciprocal space, using scanning tunnelling spectroscopy. We directly observe quantum mechanical valley interference patterns associated with linear superpositions of valleys in the donor ground state. The valley population is found to be within 5% of a bulk donor when 2.85 ± 0.45 nm from the interface, indicating that valley-perturbation-induced enhancement of spin relaxation will be negligible for depths greater than 3 nm. The observed valley interference will render two-qubit exchange gates sensitive to atomic-scale variations in positions of subsurface donors. Moreover, these results will also be of interest for emerging schemes proposing to encode information directly in valley polarization.

  16. Disorder-dependent valley properties in monolayer WSe2

    KAUST Repository

    Tran, Kha

    2017-07-19

    We investigate the effect of disorder on exciton valley polarization and valley coherence in monolayer WSe2. By analyzing the polarization properties of photoluminescence, the valley coherence (VC) and valley polarization (VP) are quantified across the inhomogeneously broadened exciton resonance. We find that disorder plays a critical role in the exciton VC, while affecting VP less. For different monolayer samples with disorder characterized by their Stokes shift (SS), VC decreases in samples with higher SS while VP does not follow a simple trend. These two methods consistently demonstrate that VC as defined by the degree of linearly polarized photoluminescence is more sensitive to disorder, motivating further theoretical studies.

  17. Subsurface stratigraphy of the eastern Hollister Valley, California

    Science.gov (United States)

    McMasters, Catherine R.; Herd, Darrell G.; Throckmorton, Constance K.; Heusser, Linda E.

    1987-01-01

    In September 1977, four cores were recovered by shallow auger drilling from Hollister Valley, California, near the Calaveras fault. The wells were drilled to search for evidence that Hollister Valley may have been occupied by a large lake during the late Pleistocene or Holocene. This small valley, near Monterey Bay, may have been dammed by a large landslide on the San Andreas fault (Jenkins, 1973; Herd and Helley, 1977). The cores sampled the first 38 m of sediment below the valley floor, but no lacustrine deposits were found at these sites; a very detailed record to Holocene alluviation in a tectonically subsiding basin. 

  18. Sea level change

    Digital Repository Service at National Institute of Oceanography (India)

    Church, J.A.; Clark, P.U.; Cazenave, A.; Gregory, J.M.; Jevrejeva, S.; Levermann, A.; Merrifield, M.A.; Milne, G.A.; Nerem, R.S.; Nunn, P.D.; Payne, A.J.; Pfeffer, W.T.; Stammer, D.; Unnikrishnan, A.S.

    .................................. 1143 13.1.4 Models Used to Interpret Past and Project Future Changes in Sea Level .............................................. 1144 13.2 Past Sea Level Change ................................................. 1145 13.2.1 The Geological Record....6.5 Regional Relative Sea Level Changes ...................... 1194 13.6.6 Uncertainties and Sensitivity to Ocean/Climate Model Formulations and Parameterizations ............ 1197 13.7 Projections of 21st Century Sea Level Extremes and Waves...

  19. The North Sea

    NARCIS (Netherlands)

    Cohen, K.M.; Westley, K.; Erkens, G.; Hijma, M.P.; Weerts, H.J.T.

    Chapter 7 in the 'SPLASHCOS Taphonomy book', on the landscape-archaeological inventory of the North Sea as a regional sea (covering British, Dutch, Belgian, German and Danish sectors of the southern and central North Sea). Abstract: This chapter gives a general overview of knowledge regarding the

  20. Oceanography of marginal seas

    Digital Repository Service at National Institute of Oceanography (India)

    DileepKumar, M.

    The North Indian Ocean consists of three marginal seas; The Persian Gulf and the Red Sea in the west and the Andaman Sea in the east. Oceanographic features of these semi-enclosed basins have been discussed in this article. While circulation...

  1. Field Surveys, IOC Valleys. Volume III, Part I. Cultural Resources Survey, Dry Lake Valley, Nevada.

    Science.gov (United States)

    1981-08-01

    Delmues (or Swiss Bob) Well where there was a station, then west across Dry Lake Valley toward Coyote Spring to another station (Lloyd, 1980). The line...in the recorded surface assemblages of the temporary camps. Further investigations may $ Etag E-TR-48-III-I 120 clarify the specific nature of the

  2. Surface slip during large Owens Valley earthquakes

    KAUST Repository

    Haddon, E. K.

    2016-01-10

    The 1872 Owens Valley earthquake is the third largest known historical earthquake in California. Relatively sparse field data and a complex rupture trace, however, inhibited attempts to fully resolve the slip distribution and reconcile the total moment release. We present a new, comprehensive record of surface slip based on lidar and field investigation, documenting 162 new measurements of laterally and vertically displaced landforms for 1872 and prehistoric Owens Valley earthquakes. Our lidar analysis uses a newly developed analytical tool to measure fault slip based on cross-correlation of sublinear topographic features and to produce a uniquely shaped probability density function (PDF) for each measurement. Stacking PDFs along strike to form cumulative offset probability distribution plots (COPDs) highlights common values corresponding to single and multiple-event displacements. Lateral offsets for 1872 vary systematically from approximate to 1.0 to 6.0 m and average 3.31.1 m (2 sigma). Vertical offsets are predominantly east-down between approximate to 0.1 and 2.4 m, with a mean of 0.80.5 m. The average lateral-to-vertical ratio compiled at specific sites is approximate to 6:1. Summing displacements across subparallel, overlapping rupture traces implies a maximum of 7-11 m and net average of 4.41.5 m, corresponding to a geologic M-w approximate to 7.5 for the 1872 event. We attribute progressively higher-offset lateral COPD peaks at 7.12.0 m, 12.8 +/- 1.5 m, and 16.6 +/- 1.4 m to three earlier large surface ruptures. Evaluating cumulative displacements in context with previously dated landforms in Owens Valley suggests relatively modest rates of fault slip, averaging between approximate to 0.6 and 1.6 mm/yr (1 sigma) over the late Quaternary.

  3. Volume of Valley Networks on Mars and Its Hydrologic Implications

    Science.gov (United States)

    Luo, W.; Cang, X.; Howard, A. D.; Heo, J.

    2015-12-01

    Valley networks on Mars are river-like features that offer the best evidence for water activities in its geologic past. Previous studies have extracted valley network lines automatically from digital elevation model (DEM) data and manually from remotely sensed images. The volume of material removed by valley networks is an important parameter that could help us infer the amount of water needed to carve the valleys. A progressive black top hat (PBTH) transformation algorithm has been adapted from image processing to extract valley volume and successfully applied to simulated landform and Ma'adim Valles, Mars. However, the volume of valley network excavation on Mars has not been estimated on a global scale. In this study, the PBTH method was applied to the whole Mars to estimate this important parameter. The process was automated with Python in ArcGIS. Polygons delineating the valley associated depressions were generated by using a multi-flow direction growth method, which started with selected high point seeds on a depth grid (essentially an inverted valley) created by PBTH transformation and grew outward following multi-flow direction on the depth grid. Two published versions of valley network lines were integrated to automatically select depression polygons that represent the valleys. Some crater depressions that are connected with valleys and thus selected in the previous step were removed by using information from a crater database. Because of large distortion associated with global dataset in projected maps, the volume of each cell within a valley was calculated using the depth of the cell multiplied by the spherical area of the cell. The volumes of all the valley cells were then summed to produce the estimate of global valley excavation volume. Our initial result of this estimate was ~2.4×1014 m3. Assuming a sediment density of 2900 kg/m3, a porosity of 0.35, and a sediment load of 1.5 kg/m3, the global volume of water needed to carve the valleys was

  4. Knickpoints and Hanging Valleys of Licus Vallis, Mars

    Science.gov (United States)

    Goudge, T. A.; Fassett, C.

    2016-12-01

    Licus Vallis is a 350 km long valley system located along the dichotomy boundary on Mars. The main trunk of the valley is incised 200-700 m into the surrounding terrain. The valley heads at an outlet breach of a shallow, 30 km diameter impact crater, and is also fed by a system of tributaries incised into the plateau surrounding Licus Vallis. Many of the tributary valleys, as well as the main stem of the valley fed by the paleolake outlet, have profiles that are not smoothly graded, but rather have distinct reaches with concave downward topography. These sections are either knickpoints or hanging valleys that develop in response to changes in the effective local base level, changes in climate conditions during incision of the valley, or lithologic boundaries in the substrate. Here we present remote sensing observations from images and topography to test these competing hypotheses and further characterize the evolution of this large valley system. Slope-watershed area relationships for the tributaries and main trunk valley are used to distinguish between knickpoints and hanging valleys. Analysis of orbital images does not reveal any distinct layer above which knickpoints develop, and the elevation of knickpoints show no systematic trends that might be expected of a regional lithologic unit(s). Our preliminary results suggest that the distance of knickpoint retreat is correlated with the position of the tributary valley and not the watershed area. Downstream valleys have retreated the most, suggesting they have had the most time to adjust to lowering of the local base level associated with incision of the main valley. These results are most consistent with a wave of incision sweeping up the valley system as it adjusts to a low base level in the northern plains. This conclusion is also consistent with observations of the incision depth of Licus Vallis, which increases approximately linearly downstream. Understanding this signature of base level control on the incision

  5. Historical Geography of the Upper Tombigbee Valley.

    Science.gov (United States)

    1982-05-01

    0-0117 005 AL4AA8A IIV IN BZFI~~N$A cmkf FOR TH4I STW ~V O5-C PlO 5/4045TORICAL W5APm or T~iq LP t’ viLLEY. tuM AY t an 0 Po ot C4714(76) iL d Au rI...Archeology Upper Tombigbee Valley Cultural Resources Tombigbee River Predictive Models * A Settlement Patterns Transportation Activities cont on n xt...Tombigbee River Multi- Resource District of the Tennessee-Tombigbee Waterway in Alabama and Mississippi. THE CENTER FOR THE STUDY OF SOUTHERN HISTORY

  6. Pleistocene glaciation in the Logar Valley

    Directory of Open Access Journals (Sweden)

    Borut Stojilković

    2013-12-01

    Full Text Available The article focuses on the glacial remains from the time of the last glacial maximum in the Logar Valley in the Kamnik-Savinja Alps. The purpose of the work is to reinterpret the findings written so far and the geomorphologic remains from the time of the Pleistocene glaciation and to prepare a new proposal of the circumference of the last glacial maximum in this area. The numerical analysis was based on the findings gained with field work. According to the findings, the maximum glacier extent was drawn and a three-dimensional reconstruction of the topography of the surface was created.

  7. Afforestation for improving valley urban air quality

    OpenAIRE

    Chu, Peter C.; Chen, Y.C.; Lu, S.H.

    2005-01-01

    Air Quality Management at Urban, Regional, and Global Scales, Third International Symposium on Air Quality Management Lanzhou is one of the major cities in northwest China and the capital of Gansu Province and located at a narrow (2-8 km width), long (40-km), NW-SE oriented valley basin (elevation: 1,500- 1,600-m) with the Tibetan plateau in the west, Baita mountain (above 1,700-m elevation) in the north, and the Gaolan mountain in the south. Due to topographic and meteorol...

  8. Neuroimaging Features of San Luis Valley Syndrome

    Directory of Open Access Journals (Sweden)

    Matthew T. Whitehead

    2015-01-01

    Full Text Available A 14-month-old Hispanic female with a history of double-outlet right ventricle and developmental delay in the setting of recombinant chromosome 8 syndrome was referred for neurologic imaging. Brain MR revealed multiple abnormalities primarily affecting midline structures, including commissural dysgenesis, vermian and brainstem hypoplasia/dysplasia, an interhypothalamic adhesion, and an epidermoid between the frontal lobes that enlarged over time. Spine MR demonstrated hypoplastic C1 and C2 posterior elements, scoliosis, and a borderline low conus medullaris position. Presented herein is the first illustration of neuroimaging findings from a patient with San Luis Valley syndrome.

  9. The uncanny valley in games and animation

    CERN Document Server

    Tinwell, Angela

    2014-01-01

    Advances in technology have enabled animators and video game designers to design increasingly realistic, human-like characters in animation and games. Although it was intended that this increased realism would allow viewers to appreciate the emotional state of characters, research has shown that audiences often have a negative reaction as the human likeness of a character increases. This phenomenon, known as the Uncanny Valley, has become a benchmark for measuring if a character is believably realistic and authentically human like. This book is an essential guide on how to overcome the Uncanny

  10. Deep sea study takes a new approach

    Science.gov (United States)

    Robigou, Véronique; Ballard, Robert D.

    The rapidly evolving technology of remotely operated vehicles (ROV) is revolutionizing the exploration and study of deepwater environments. In 1991, the JASON/MEDEA ROV system exhibited its high-resolution imaging capabilities in the rugged hydrothermal environment of the Endeavour Segment, northern Juan de Fuca Ridge [Delaney et al., 1991; Sempéré et al., 1991]. In 1992, the Canadian Remotely Operated Platform for Ocean Science (ROPOS) successfully sampled hydrothermal vents along the Juan de Fuca Ridge and recovered data from an Ocean Drilling Program borehole in Middle Valley, northern Juan de Fuca Ridge [Embley and Franklin, 1993]. In 1993, a 21-day expedition to the Guaymas Basin, Gulf of California, Mexico, went a step further, combining ROV and manned-submersible assets to maximize the effectiveness of both vehicles for scientific use and ultimately demonstrating a completely new approach to deep-sea research.

  11. Variability of three-dimensional sea breeze structure in southern France: observations and evaluation of empirical scaling laws

    Directory of Open Access Journals (Sweden)

    P. Drobinski

    2006-08-01

    Full Text Available Sea-breeze dynamics in southern France is investigated using an airborne Doppler lidar, a meteorological surface station network and radiosoundings, in the framework of the ESCOMPTE experiment conducted during summer 2001 in order to evaluate the role of thermal circulations on pollutant transport and ventilation. The airborne Doppler lidar WIND contributed to three-dimensional (3-D mapping of the sea breeze circulation in an unprecedented way. The data allow access to the onshore and offshore sea breeze extents (xsb, and to the sea breeze depth (zsb and intensity (usb. They also show that the return flow of the sea breeze circulation is very seldom seen in this area due to (i the presence of a systematic non zero background wind, and (ii the 3-D structure of the sea breeze caused by the complex coastline shape and topography. A thorough analysis is conducted on the impact of the two main valleys (Rhône and Durance valleys affecting the sea breeze circulation in the area. Finally, this dataset also allows an evaluation of the existing scaling laws used to derive the sea breeze intensity, depth and horizontal extent. The main results of this study are that (i latitude, cumulative heating and surface friction are key parameters of the sea breeze dynamics; (ii in presence of strong synoptic flow, all scaling laws fail in predicting the sea breeze characteristics (the sea breeze depth, however being the most accurately predicted; and (iii the ratio zsb/usb is approximately constant in the sea breeze flow.

  12. Oscillating Nocturnal Slope Flow in a Coastal Valley

    DEFF Research Database (Denmark)

    Gryning, Sven-Erik; Larsen, Søren Ejling; Mahrt, Larry

    1985-01-01

    over the sloping valley floor was studied during a special observing campaign. A downslope gravity flow interacts with even colder surface air at the valley floor. The latter originates as cold marine air or previous drainage of cold air. Regular oscillations which appear to be trapped, terrain...

  13. 27 CFR 9.208 - Snake River Valley.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Snake River Valley. 9.208... Snake River Valley. (a) Name. The name of the viticultural area described in this section is “Snake River Valley”. For purposes of part 4 of this chapter, “Snake River Valley” is a term of viticultural...

  14. Rift Valley Fever Outbreak in Livestock, Mozambique, 2014

    Science.gov (United States)

    Coetzee, Peter; Mubemba, Benjamin; Nhambirre, Ofélia; Neves, Luis; Coetzer, J.A.W.; Venter, Estelle H.

    2016-01-01

    In early 2014, abortions and death of ruminants were reported on farms in Maputo and Gaza Provinces, Mozambique. Serologic analysis and quantitative and conventional reverse transcription PCR confirmed the presence of Rift Valley fever virus. The viruses belonged to lineage C, which is prevalent among Rift Valley fever viruses in southern Africa. PMID:27869589

  15. Some Environmental Issues of Inland Valleys: A Case Study | Asiam ...

    African Journals Online (AJOL)

    The study concluded that inland valleys can be real environmental liability because produce from such valleys can be polluted and hence can be a source of social conflict particularly when they fringe mineral concessions as the adverse impacts could be unfortunately attributed to mining activity and similar land uses.

  16. Characterization of inland-valleys for smallholder dairy production in ...

    African Journals Online (AJOL)

    A two-level (village or town, household level) characterization of inland-valley areas was undertaken in order to assess the potentials and constraints associated with inland-valleys agriculture production in a croplivestock system in 3 west african countries (Côte d'Ivoire, Mali and Nigeria). User groups and opinion leaders in ...

  17. Groundwater recharge on east side soils of the Salinas Valley

    Science.gov (United States)

    After four years of drought, groundwater levels in the Salinas Valley are at historically low levels which threaten to adversely affect farming in the Salinas Valley. Given the prospect of a strong El Niño this coming winter, it seems prudent to plan to capture as much of the rainfall as possible to...

  18. Valley Fever: Danger Lurking in a Dust Cloud

    Science.gov (United States)

    Johnson, Larry; Gaab, Erin M.; Sanchez, Javier; Bui, Phuong Q.; Nobile, Clarissa J.; Hoyer, Katrina K.; Peterson, Michael W.; Ojcius, David M.

    2014-01-01

    Coccidioides immitis and Coccidioides posadasii contribute to the development of Valley Fever. The ability of these fungal pathogens to evade the host immune system creates difficulty in recognition and treatment of this debilitating infection. In this review, we describe the current knowledge of Valley Fever and approaches to improve prevention, detection, and treatment. PMID:25038397

  19. Cache valley virus in a patient diagnosed with aseptic meningitis.

    Science.gov (United States)

    Nguyen, Nang L; Zhao, Guoyan; Hull, Rene; Shelly, Mark A; Wong, Susan J; Wu, Guang; St George, Kirsten; Wang, David; Menegus, Marilyn A

    2013-06-01

    Cache Valley virus was initially isolated from mosquitoes and had been linked to central nervous system-associated diseases. A case of Cache Valley virus infection is described. The virus was cultured from a patient's cerebrospinal fluid and identified with real-time reverse transcription-PCR and sequencing, which also yielded the complete viral coding sequences.

  20. 36 CFR 7.26 - Death Valley National Monument.

    Science.gov (United States)

    2010-07-01

    ... Monument. 7.26 Section 7.26 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.26 Death Valley National Monument. (a) Mining. Mining in Death Valley National Monument is subject to the following regulations, which are...

  1. A plateau-valley separation method for multifunctional surfaces characterization

    DEFF Research Database (Denmark)

    Godi, Alessandro; Kühle, A.; De Chiffre, Leonardo

    2012-01-01

    method based on the separation between the plateau and valley regions has been developed. After properly determining a threshold between plateaus and valleys, the two regions are divided in two distinct profiles, which can be studied separately according to the specific function....

  2. Stream valleys and the coast, a reconnaissance soil-landscape analysis

    Science.gov (United States)

    van den Ancker, J. A. M.; Jungerius, P. D.

    2012-04-01

    The Council of Earth Sciences of the KNAW, the Royal Dutch Academy of Art and Sciences, started in 2008 a working group to discuss the low awareness of Dutch geoheritage and the operationalization of the geodiversity concept for modern sustainable spatial planning. More than forty earth scientists participated in the workgroup. Both authors of this poster were part of the organizing committee. The development of a new planning tool, based on the seven soil functions of the EU Soil Directive (2006) was proposed for a modern multi-functional and sustainable approach towards spatial planning. For reconnaissance purposes, two simplified examples were developed to illustrate the possibilities of the approach. The coastal example became part of the report, the stream valley example was never published. Both examples are presented in a short cross-table format on this poster. The Dutch stream valleys first were divided into five valley types according to present land-use and management. Next, it was recorded how each valley type performed on each of the seven EU soil functions. The results show that the majority of the stream valleys, probably more than 90 %, are mono-functional and directed at high agricultural production, which has an adverse effect on all the other soil functions in the area (and areas and waters outside the valley area studied). Along the coast the importance of the beach as a sea defence buffer and an economic tourism asset clearly showed. This is of course nothing new, but in spatial planning the economic role of tourism and especially the important role of the beach in sea defence are normally overlooked. The cross-tables of the EU soil functions show to be a good and simple tool to promote insight and discussion towards a more sustainable and multi-functional landuse. The KNAW report was presented to the Minister of the Environment in 2009, with the recommendation that the approach needed further development. Due to political shifts and government

  3. Hoopa Valley Small Scale Hydroelectric Feasibility Project

    Energy Technology Data Exchange (ETDEWEB)

    Curtis Miller

    2009-03-22

    This study considered assessing the feasibility of developing small scale hydro-electric power from seven major tributaries within the Hoopa Valley Indian Reservation of Northern California (http://www.hoopa-nsn.gov/). This study pursued the assessment of seven major tributaries of the Reservation that flow into the Trinity River. The feasibility of hydropower on the Hoopa Valley Indian Reservation has real potential for development and many alternative options for project locations, designs, operations and financing. In order to realize this opportunity further will require at least 2-3 years of intense data collection focusing on stream flow measurements at multiple locations in order to quantify real power potential. This also includes on the ground stream gradient surveys, road access planning and grid connectivity to PG&E for sale of electricity. Imperative to this effort is the need for negotiations between the Hoopa Tribal Council and PG&E to take place in order to finalize the power rate the Tribe will receive through any wholesale agreement that utilizes the alternative energy generated on the Reservation.

  4. Salts in the dry valleys of Antartica

    Science.gov (United States)

    Gibson, E. K., Jr.; Presley, B. J.; Hatfield, J.

    1984-01-01

    The Dry Valleys of Antarctica are examples of polar deserts which are rare geological features on the Earth. Such deserts typically have high salinities associated with their closed-basin waters and on many surficial materials throughout them. In order to examine the possible sources for the salts observed in association with the soils in the Dry Valleys. The chloride and bromide concentrations of the water leachates from 58 soils and core samples were measured. The Cl/Br ratio for seawater is 289 and ratios measured for most of the 58 soils studied (greater than 85% of the soils studied) was larger than the seawater ratio (ratios typically were greater than 1000 and ranged up to 50,000). The enrichment in Cl relative to Br is strong evidence that the alts present within the soils were derived from seawater during ordinary evaporation processes, and not from the deposition of Cl and Br from aerosols or from rock weathering as has often been suggested.

  5. Geddes, Zoos and the Valley Section

    Directory of Open Access Journals (Sweden)

    Catherine Thompson

    2004-12-01

    Full Text Available The development of Edinburgh Zoological Garden was a pioneering example of the modern approach to animal display, placing animals in naturalistic settings that demanded innovative landscape design. The concept for Edinburgh Zoo, opened in 1913, was devised by Patrick Geddes and developed in collaboration with Frank C Mears and Geddes's daughter, Norah. This paper draws on Welter's (2002 important study of Geddes's vision of the city and on Geddes biographies, as well as on original archive material, to explore aspects of Geddes's vision for landscape architecture in the early twentieth century. The paper discusses Geddes's contribution to contemporary design and planning theory through the concept of the valley section, which comes to an understanding of the global through the local and in turn inspires a vision of the universal. Geddes was influenced by Hagenbeck's design for his zoo, near Hamburg, and by the New York Zoological Park, in developing displays for Edinburgh zoo that attempted to show animal behaviour as it would be in its natural habitat. The work of the German evolutionary biologist, Ernst Haeckel, further inspired Geddes to conceptualise the design as one where, just as ontogeny recapitulates phylogeny, so human civilisation might be recapitulated. He developed a three-dimensional expression of his hypothetical 'valley section' as a model for interaction between life and the environment. The zoo 'within' a city becomes a model for the ideal city, a city 'within' its region, reflecting the highest attainment of human development, yet still linked to the most primitive of origins.

  6. A Three-Dimensional Seismic Model of the Dead Sea Plate Boundary From Active Source Data

    Science.gov (United States)

    Flores, C. H.; ten Brink, U. S.

    2007-12-01

    The Dead Sea fault system is a north-south striking left-lateral shear zone separating the African and Arabian tectonic plates. The southern part of the plate boundary is located within the Dead Sea valley. The valley, much of it below sea level, is surrounded by highlands on both sides, and contains subsurface sedimentary basins, including the large (~150 km long) a deep (6-8 km) Dead Sea basin. A wide-angle seismic reflection and refraction experiment was carried out in the Dead Sea Region in October 2004 to study the deep structure of the plate boundary. The experiment consisted of two perpendicular profiles a 280-km long profile along the valley and the international border between Jordan, Israel and the Palestinian Territories, and a 250 km long profile from Gaza strip to eastern Jordan across the Dead Sea basin. Modeling of the West-East line shows a low velocity zone extending to a depth of 18 km below the basin, which includes >6 km of "syn-rift" sediments (ten Brink et al., GRL, 2006). The lower crust and Moho are not perturbed. The uplift surrounding the Dead Sea Transform also appears to be an upper crustal phenomenon. The shear deformation, associated with the transform plate boundary motion appears, on the other hand, to cut throughout the entire crust (Ibid.). Two-dimensional modeling of the South-North line is more complex due to the fact that sedimentary basins do not occupy the entire width of the valley hence some sources and some receivers are located within the basins whereas others are located outside. This heterogeneous near-surface structure explains why a simple 2-D velocity model does not fit the observed travel times from all shots. Therefore, we are using 3-D travel-time tomography to model the heterogeneous near-surface and deeper structure of the Dead Sea. Preliminary models indicate that some ray-paths from sources near the basin use the edges of the basin as a wave-guide and generate earlier than expected arrivals at receivers near

  7. Geology and water resources of Owens Valley, California

    Science.gov (United States)

    Hollett, Kenneth J.; Danskin, Wesley R.; McCaffrey, William F.; Walti, Caryl L.

    1991-01-01

    Owens Valley, a long, narrow valley located along the east flank of the Sierra Nevada in east-central California, is the main source of water for the city of Los Angeles. The city diverts most of the surface water in the valley into the Owens River-Los Angeles Aqueduct system, which transports the water more than 200 miles south to areas of distribution and use. Additionally, ground water is pumped or flows from wells to supplement the surface-water diversions to the river-aqueduct system. Pumpage from wells needed to supplement water export has increased since 1970, when a second aqueduct was put into service, and local concerns have been expressed that the increased pumpage may have had a detrimental effect on the environment and the indigenous alkaline scrub and meadow plant communities in the valley. The scrub and meadow communities depend on soil moisture derived from precipitation and the unconfined part of a multilayered aquifer system. This report, which describes the hydrogeology of the aquifer system and the water resources of the valley, is one in a series designed to (1) evaluate the effects that groundwater pumping has on scrub and meadow communities and (2) appraise alternative strategies to mitigate any adverse effects caused by, pumping. Two principal topographic features are the surface expression of the geologic framework--the high, prominent mountains on the east and west sides of the valley and the long, narrow intermountain valley floor. The mountains are composed of sedimentary, granitic, and metamorphic rocks, mantled in part by volcanic rocks as well as by glacial, talus, and fluvial deposits. The valley floor is underlain by valley fill that consists of unconsolidated to moderately consolidated alluvial fan, transition-zone, glacial and talus, and fluvial and lacustrine deposits. The valley fill also includes interlayered recent volcanic flows and pyroclastic rocks. The bedrock surface beneath the valley fill is a narrow, steep-sided graben

  8. Four newly recorded species of Dryopteridaceae from Kashmir valley, India

    Directory of Open Access Journals (Sweden)

    SHAKOOR AHMAD MIR

    2014-04-01

    Full Text Available Mir SA, Mishra AK, Reshi ZA, Sharma MP. 2014. Four newly recorded species of Dryopteridaceae from Kashmir valley, India. Biodiversitas 15: 6-11. Habitat diversity, elevation, cloud cover, rainfall, seasonal and temperature variations have created many ideal sites for the luxuriant growth of pteridophytes in the Kashmir valley, yet all the regions of the valley have not been surveyed. In Kashmir valley the family Dryopteridaceae is represented by 31 species. During the recent extensive field surveys of Shopian district four more species viz., Dryopteris caroli-hopei Fraser-Jenkins, Dryopteris blanfordii subsp. nigrosquamosa (Ching Fraser-Jenkins, Dryopteris pulvinulifera (Bedd. Kuntze and Polystichum Nepalense (Spreng C. Chr. have been recorded for the first time from the valley. The taxonomic description, synonyms, distribution and photographs of each species are given in this article.

  9. Detection of valley polarization in graphene by a superconducting contact.

    Science.gov (United States)

    Akhmerov, A R; Beenakker, C W J

    2007-04-13

    Because the valleys in the band structure of graphene are related by time-reversal symmetry, electrons from one valley are reflected as holes from the other valley at the junction with a superconductor. We show how this Andreev reflection can be used to detect the valley polarization of edge states produced by a magnetic field. In the absence of intervalley relaxation, the conductance GNS=(2e2/h)(1-cosTheta) of the junction on the lowest quantum Hall plateau is entirely determined by the angle Theta between the valley isospins of the edge states approaching and leaving the superconductor. If the superconductor covers a single edge, Theta=0 and no current can enter the superconductor. A measurement of GNS then determines the intervalley relaxation time.

  10. Salish Sea Genetics - Salish Sea genetic inventory

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Salish Sea comprises most of the Puget Sound water area. Marine species are generally assemblages of discrete populations occupying various ecological niches....

  11. Fracture controls on valley persistence: the Cairngorm Granite pluton, Scotland

    Science.gov (United States)

    Hall, A. M.; Gillespie, M. R.

    2017-09-01

    Valleys are remarkably persistent features in many different tectonic settings, but the reasons for this persistence are rarely explored. Here, we examine the structural controls on valleys in the Cairngorms Mountains, Scotland, part of the passive margin of the eastern North Atlantic. We consider valleys at three scales: straths, glens and headwater valleys. The structural controls on valleys in and around the Cairngorm Granite pluton were examined on satellite and aerial photographs and by field survey. Topographic lineaments, including valleys, show no consistent orientation with joint sets or with sheets of microgranite and pegmatitic granite. In this granite landscape, jointing is not a first-order control on valley development. Instead, glens and headwater valleys align closely to quartz veins and linear alteration zones (LAZs). LAZs are zones of weakness in the granite pluton in which late-stage hydrothermal alteration and hydro-fracturing have greatly reduced rock mass strength and increased permeability. LAZs, which can be kilometres long and >700 m deep, are the dominant controls on the orientation of valleys in the Cairngorms. LAZs formed in the roof zone of the granite intrusion. Although the Cairngorm pluton was unroofed soon after emplacement, the presence of Old Red Sandstone (ORS) outliers in the terrain to the north and east indicates that the lower relief of the sub-ORS basement surface has been lowered by 1 km of vertical erosion and for 400 Myr. This valley persistence is a combined product of regionally low rates of basement exhumation and of the existence of LAZs in the Cairngorm pluton and sub-parallel Caledonide fractures in the surrounding terrain with depths that exceed 1 km.

  12. Groundwater salinity influenced by Holocene seawater trapped in incised valleys in the Red River delta plain

    Science.gov (United States)

    Larsen, Flemming; Tran, Long Vu; van Hoang, Hoan; Tran, Luu Thi; Christiansen, Anders Vest; Pham, Nhan Quy

    2017-04-01

    Salty and brackish groundwater has been observed at least 100 km inland in some aquifers contained within Quaternary delta plains. This phenomenon limits access to fresh groundwater resources, particularly in the densely populated deltas of Southeast Asia. However, the causes of inland salinity are unclear. Here we present borehole and geophysical data that show that in the Red River delta plain of Vietnam, salty and brackish groundwater primarily occurs in incised valleys that were formed during sea-level lowstands during the Pleistocene. During the mid-Holocene, these valleys were filled with fine-grained marine deposits containing trapped seawater. We conduct groundwater flow simulations that show that the age, thickness, and permeability of the marine sediments are the primary controls on the leaching of salty porewater into the freshwater aquifer. We find that salty groundwater originating from this trapped seawater is still present in Holocene-aged sediments with low permeability, and affects groundwater salinity in adjacent aquifers. In contrast, trapped seawater from all Pleistocene-aged sediments has been leached. We identify a number of brackish to saline delta aquifers elsewhere in Asia and throughout the world that have a similar sedimentary history, and thus are likely to be influenced by this leaching process.

  13. Intensified dust storm activity and Valley fever infection in the southwestern United States

    Science.gov (United States)

    Tong, Daniel Q.; Wang, Julian X. L.; Gill, Thomas E.; Lei, Hang; Wang, Binyu

    2017-05-01

    Climate models have consistently projected a drying trend in the southwestern United States, aiding speculation of increasing dust storms in this region. Long-term climatology is essential to documenting the dust trend and its response to climate variability. We have reconstructed long-term dust climatology in the western United States, based on a comprehensive dust identification method and continuous aerosol observations from the Interagency Monitoring of Protected Visual Environments (IMPROVE) network. We report here direct evidence of rapid intensification of dust storm activity over American deserts in the past decades (1988-2011), in contrast to reported decreasing trends in Asia and Africa. The frequency of windblown dust storms has increased 240% from 1990s to 2000s. This dust trend is associated with large-scale variations of sea surface temperature in the Pacific Ocean, with the strongest correlation with the Pacific Decadal Oscillation. We further investigate the relationship between dust and Valley fever, a fast-rising infectious disease caused by inhaling soil-dwelling fungus (Coccidioides immitis and C. posadasii) in the southwestern United States. The frequency of dust storms is found to be correlated with Valley fever incidences, with a coefficient (r) comparable to or stronger than that with other factors believed to control the disease in two endemic centers (Maricopa and Pima County, Arizona).

  14. Benthos of the Gorda Ridge axial valley (NE Pacific Ocean): Taxonomic composition and trends in distribution

    Science.gov (United States)

    Carey, A. G.; Stein, D. L.; Rona, P. L.

    Distribution and relative abundance of invertebrate mega-epifauna and benthic fishes were studied in the Gorda Ridge central rift valley off southern Oregon and northern California, USA. Faunal distribution and relative abundance were correlated with location, geological setting, substrate type, and depth. Bottom photographs and videotapes were from 1985-1986 cruises by the US Geological Survey and the US National Oceanic and Atmospheric Administration. Voucher specimens were collected by rock dredge, fish trap, and the Deep Submergence Vehicle (DSV) Sea Cliff. Location rather than substrate appears to have more effect on the overall taxonomic composition of the mega-epifauna in the northern and southern parts of the rift valley. Within each location, substrate type, i.e. soft sediments and rock outcrops, and percentage cover of these substrates appear to influence the existing faunal composition. Characteristic fauna are associated with each substrate type, e.g. crinoids, gorgonians and sponges (Demospongiae) on rocky surfaces. In the southern sediment-filled Escanaba Trough, deposit-feeding organisms, particularly ophiuroids, asteroids and holothuroids, are interspersed with stalked suspension feeders, such as hexactinellid sponges and pennatulids. Epifaunal community structure in the northern and southern sectors differs, even on similar substrate combinations. Except for the ubiquitous macrourids, fish species distributions may be correlated with substrate type. Abundant particulate material in the bottom water layer probably accounts for large concentrations of suspension and detritus feeding epibenthos.

  15. Assessing Ecotourism Potential of Traditional Wooden Architecture in Rural Areas: The Case of Papart Valley

    Directory of Open Access Journals (Sweden)

    Taner Okan

    2016-09-01

    Full Text Available The aim of this study is to reveal the resource values that the rural areas host, and with a very disciplined approach, to discuss opportunities to benefit from those values in terms of ecotourism practices specific to Papart Valley. As a first step in this study, we took an inventory of natural and cultural assets of Papart Valley in Eastern Black Sea Region, Artvin province. Then, a Strengths, Weaknesses, Opportunities and Threats (SWOT analysis was conducted with the participation of all stakeholders and the current situation was analyzed in terms of ecotourism practices. In light of SWOT results, along with observed natural resource assets in the region, the traditional wooden houses were seen to have potential in terms of ecotourism and it was detected that there were a large number of wooden homes and home plans suitable for both the settlement of the local people and accommodation of guests. On the other hand, it was determined that there was a lack of information for sufficient protection and care of wooden houses, and despite their potential, there was a lack of regulations and positive attitudes towards accomodation businesses in traditional wooden houses. In order to eliminate these deficiencies, proposals for the protection of traditional building stock were developed, by first determining the causes of material degradation in the wooden houses. Also, to emphasize the worth and importance of these structures, dendrochronology studies were conducted in order to determine the antiquity of the structures and potentially to make them more attractive for eco-tourism.

  16. Water resources of Parowan Valley, Iron County, Utah

    Science.gov (United States)

    Marston, Thomas M.

    2017-08-29

    Parowan Valley, in Iron County, Utah, covers about 160 square miles west of the Red Cliffs and includes the towns of Parowan, Paragonah, and Summit. The valley is a structural depression formed by northwest-trending faults and is, essentially, a closed surface-water basin although a small part of the valley at the southwestern end drains into the adjacent Cedar Valley. Groundwater occurs in and has been developed mainly from the unconsolidated basin-fill aquifer. Long-term downward trends in groundwater levels have been documented by the U.S. Geological Survey (USGS) since the mid-1950s. The water resources of Parowan Valley were assessed during 2012 to 2014 with an emphasis on refining the understanding of the groundwater and surface-water systems and updating the groundwater budget.Surface-water discharge of five perennial mountain streams that enter Parowan Valley was measured from 2013 to 2014. The total annual surface-water discharge of the five streams during 2013 to 2014 was about 18,000 acre-feet (acre-ft) compared to the average annual streamflow of about 22,000 acre-ft from USGS streamgages operated on the three largest of these streams from the 1940s to the 1980s. The largest stream, Parowan Creek, contributes more than 50 percent of the annual surface-water discharge to the valley, with smaller amounts contributed by Red, Summit, Little, and Cottonwood Creeks.Average annual recharge to the Parowan Valley groundwater system was estimated to be about 25,000 acre-ft from 1994 to 2013. Nearly all recharge occurs as direct infiltration of snowmelt and rainfall on the Markagunt Plateau east of the valley. Smaller amounts of recharge occur as infiltration of streamflow and unconsumed irrigation water near the east side of the valley on alluvial fans associated with mountain streams at the foot of the Red Cliffs. Subsurface flow from the mountain block to the east of the valley is a significant source of groundwater recharge to the basin-fill aquifer

  17. Geothermal Resource Verification for Air Force Bases,

    Science.gov (United States)

    1981-06-01

    680OF (3600 C) in the Salton Sea, California, and the nearby Cerro Prieto region of Mexico. Liquid water can exist underground in nature to a maxi...northwest Mexico’s Cerro Prieto field and southcentral California’s Imperial Valley area [banwell (1970)]. The Baca field in New Mexico’s Jemez Mountains...AO-AIOQ bA SANDI NA IONCAL L AB NURU NNI 1/ GEOTHERMAL RESOURCE VER IFIC A FR AIR FORCE RASES, 1W UCJUN 81 P f GRANT DE-AC04-TAiDOpOos WACLASSIFIED

  18. Waves in the seas

    Digital Repository Service at National Institute of Oceanography (India)

    Varkey, M.J.

    of component waves of various periods and heights. This is the most commonly used theory for practical applications like design of ships, oil rigs and coastal structures such as jetties, ports, and sea walls. This theory also provides sufficient intellectual... of wind waves in the sea is a wide and interesting field with ap- plications in marine exploration ac- tivities, underwater pipe laying, pol- lution control, ports and shipping in- volving billions of dollars worth of transactions. Not all sea waves look...

  19. Lead in Sea Otters

    OpenAIRE

    Simth D.R.; Flegal A.R.; Estes J.A:

    1991-01-01

    As yet there is no direct evidence that environmental pollutants affect sea otter populations. However, this may be from lack of looking. The first steps in these investigations are to measure levels of potential environmental contaminants in sea otters, determine whether these levels vary among populations, and compare the findings with those from other mustelids/otters for which there is a known or suspected impact. Our approach is to compare measurements between Alaska, where sea otter pop...

  20. SEA in Southern Africa

    CSIR Research Space (South Africa)

    Audouin, M

    2011-01-01

    Full Text Available advocated by SEACAM (Audouin et al, 2003). Some examples of processes broadly reflecting the principles of SEA are provided in Box 9.1. These examples show that SEA tends to be undertaken as part of other processes, such as integrated land-use planning... Development Challenge Rural Development Programme, SEA for the central Namib Uranium Rush and SEA of the Karas Land Use Plan. References Audouin, M., Govender, K. and Ramasar, V. (2003) Guidelines for the Strategic Environmental Assessment, prepared...

  1. SEA and planning

    DEFF Research Database (Denmark)

    Stoeglehner, G.; Brown, A.L.; Kørnøv, Lone

    2009-01-01

    As the field of strategic environmental assessment (SEA) has matured, the focus has moved from the development of legislation, guidelines and methodologies towards improving the effectiveness of SEA. Measuring and of course achieving effectiveness is both complex and challenging. This paper......, and the relationship of the SEA to the planning activity itself. This paper focuses on the influence that planners have in these implementation processes, postulating the hypothesis that these are key players in achieving effectiveness in SEA. Based upon implementation theory and empirical experience, the paper...

  2. An epidemiological model of Rift Valley fever

    Directory of Open Access Journals (Sweden)

    Nicole P. Leahy

    2007-08-01

    Full Text Available We present and explore a novel mathematical model of the epidemiology of Rift Valley Fever (RVF. RVF is an Old World, mosquito-borne disease affecting both livestock and humans. The model is an ordinary differential equation model for two populations of mosquito species, those that can transmit vertically and those that cannot, and for one livestock population. We analyze the model to find the stability of the disease-free equlibrium and test which model parameters affect this stability most significantly. This model is the basis for future research into the predication of future outbreaks in the Old World and the assessment of the threat of introduction into the New World.

  3. Rift Valley Fever, Sudan, 2007 and 2010

    Science.gov (United States)

    Aradaib, Imadeldin E.; Erickson, Bobbie R.; Elageb, Rehab M.; Khristova, Marina L.; Carroll, Serena A.; Elkhidir, Isam M.; Karsany, Mubarak E.; Karrar, AbdelRahim E.; Elbashir, Mustafa I.

    2013-01-01

    To elucidate whether Rift Valley fever virus (RVFV) diversity in Sudan resulted from multiple introductions or from acquired changes over time from 1 introduction event, we generated complete genome sequences from RVFV strains detected during the 2007 and 2010 outbreaks. Phylogenetic analyses of small, medium, and large RNA segment sequences indicated several genetic RVFV variants were circulating in Sudan, which all grouped into Kenya-1 or Kenya-2 sublineages from the 2006–2008 eastern Africa epizootic. Bayesian analysis of sequence differences estimated that diversity among the 2007 and 2010 Sudan RVFV variants shared a most recent common ancestor circa 1996. The data suggest multiple introductions of RVFV into Sudan as part of sweeping epizootics from eastern Africa. The sequences indicate recent movement of RVFV and support the need for surveillance to recognize when and where RVFV circulates between epidemics, which can make data from prediction tools easier to interpret and preventive measures easier to direct toward high-risk areas. PMID:23347790

  4. Direct measurement of exciton valley coherence in monolayer WSe2

    KAUST Repository

    Hao, Kai

    2016-02-29

    In crystals, energy band extrema in momentum space can be identified by a valley index. The internal quantum degree of freedom associated with valley pseudospin indices can act as a useful information carrier, analogous to electronic charge or spin. Interest in valleytronics has been revived in recent years following the discovery of atomically thin materials such as graphene and transition metal dichalcogenides. However, the valley coherence time—a crucial quantity for valley pseudospin manipulation—is difficult to directly probe. In this work, we use two-dimensional coherent spectroscopy to resonantly generate and detect valley coherence of excitons (Coulomb-bound electron–hole pairs) in monolayer WSe2 (refs ,). The imposed valley coherence persists for approximately one hundred femtoseconds. We propose that the electron–hole exchange interaction provides an important decoherence mechanism in addition to exciton population recombination. This work provides critical insight into the requirements and strategies for optical manipulation of the valley pseudospin for future valleytronics applications.

  5. Origin and evolution of valleys on Martian volcanoes

    Energy Technology Data Exchange (ETDEWEB)

    Gulick, V.C.; Baker, V.R. (Univ. of Arizona, Tucson (USA))

    1990-08-30

    Morphological analyses of six Martian volcanoes, Ceraunius Tholus, Hecates Tholus, Alba Patera, Hadriaca Patera, Apollinaris Patera, and Tyrrhena Patera, indicate that fluvial processes were the dominant influence in the initiation and subsequent development of many dissecting valleys. Lava processes and possibly volcanic density flows were also important as valley-forming processes. Fluvial valleys are especially well developed on Alba Patera, Ceraunius Tholus, and Hecates Tholus. These valleys are inset into the surrounding landscape. They formed in regions of subdued lava flow morphology, contain tributaries, and tend to widen slightly in the downstream direction. Lava channels on Alba Patera are located on the crest of lava flows and have a discontinuous, irregular surface morphology, and distributary patterns. These channels sometimes narrow toward their termini. Possible volcanic density flow channels are located on the northern flank of Ceraunius Tholus. Valleys dissecting Apollinaris Patera, Hadriaca Patera, and Tyrrhena Patera appear to have a complex evolution, probably a mixed fluvial and lava origin. They are inset into a subdued (possibly mantled) surface, lack tributaries, and either have fairly constant widths or widen slightly downvalley. Valleys surrounding the caldera of Apollinaris appear to have formed by fluvial and possibly by volcanic density flow processes, while those on the Apollinaris fan structure may have a mixed lava and fluvial origin. Valleys on Tyrrhena have broad flat floors and theater heads, which have been extensively enlarged, probably by sapping.

  6. Topological valley transport at bilayer graphene domain walls.

    Science.gov (United States)

    Ju, Long; Shi, Zhiwen; Nair, Nityan; Lv, Yinchuan; Jin, Chenhao; Velasco, Jairo; Ojeda-Aristizabal, Claudia; Bechtel, Hans A; Martin, Michael C; Zettl, Alex; Analytis, James; Wang, Feng

    2015-04-30

    Electron valley, a degree of freedom that is analogous to spin, can lead to novel topological phases in bilayer graphene. A tunable bandgap can be induced in bilayer graphene by an external electric field, and such gapped bilayer graphene is predicted to be a topological insulating phase protected by no-valley mixing symmetry, featuring quantum valley Hall effects and chiral edge states. Observation of such chiral edge states, however, is challenging because inter-valley scattering is induced by atomic-scale defects at real bilayer graphene edges. Recent theoretical work has shown that domain walls between AB- and BA-stacked bilayer graphene can support protected chiral edge states of quantum valley Hall insulators. Here we report an experimental observation of ballistic (that is, with no scattering of electrons) conducting channels at bilayer graphene domain walls. We employ near-field infrared nanometre-scale microscopy (nanoscopy) to image in situ bilayer graphene layer-stacking domain walls on device substrates, and we fabricate dual-gated field effect transistors based on the domain walls. Unlike single-domain bilayer graphene, which shows gapped insulating behaviour under a vertical electrical field, bilayer graphene domain walls feature one-dimensional valley-polarized conducting channels with a ballistic length of about 400 nanometres at 4 kelvin. Such topologically protected one-dimensional chiral states at bilayer graphene domain walls open up opportunities for exploring unique topological phases and valley physics in graphene.

  7. Geothermal hydrology of Warner Valley, Oregon: a reconnaissance study

    Energy Technology Data Exchange (ETDEWEB)

    Sammel, E.A.; Craig, R.W.

    1981-01-01

    Warner Valley and its southern extension, Coleman Valley, are two of several high-desert valleys in the Basin and Range province of south-central Oregon that contain thermal waters. At least 20 thermal springs, defined as having temperatures of 20/sup 0/C or more, issue from Tertiary basaltic flows and tuffs in and near the valleys. Many shallow wells also produce thermal waters. The highest measured temperature is 127/sup 0/C, reported from a well known as Crump geyser, at a depth of 200 meters. The hottest spring, located near Crump geyser, has a surface temperature of 78/sup 0/C. The occurrence of these thermal waters is closely related to faults and fault intersections in the graben and horst structure of the valleys. Chemical analyses show that the thermal waters are of two types: sodium chloride and sodium bicarbonate waters. Chemical indicators show that the geothermal system is a hot-water rather than a vapor-dominated system. Conductive heat flow in areas of the valley unaffected by hydrothermal convection is probably about 75 milliwatts per square meter. The normal thermal gradient in valley-fill dpeosits in these areas may be about 40/sup 0/C per kilometer. Geothermometers and mixing models indicate that temperatures of equilibration are at least 170/sup 0/C for the thermal components of the hotter waters. The size and location of geothermal reservoirs are unknown.

  8. Functional ecology of an Antarctic Dry Valley

    Science.gov (United States)

    Chan, Yuki; Van Nostrand, Joy D.; Zhou, Jizhong; Pointing, Stephen B.

    2013-01-01

    The McMurdo Dry Valleys are the largest ice-free region in Antarctica and are critically at risk from climate change. The terrestrial landscape is dominated by oligotrophic mineral soils and extensive exposed rocky surfaces where biota are largely restricted to microbial communities, although their ability to perform the majority of geobiological processes has remained largely uncharacterized. Here, we identified functional traits that drive microbial survival and community assembly, using a metagenomic approach with GeoChip-based functional gene arrays to establish metabolic capabilities in communities inhabiting soil and rock surface niches in McKelvey Valley. Major pathways in primary metabolism were identified, indicating significant plasticity in autotrophic, heterotrophic, and diazotrophic strategies supporting microbial communities. This represents a major advance beyond biodiversity surveys in that we have now identified how putative functional ecology drives microbial community assembly. Significant differences were apparent between open soil, hypolithic, chasmoendolithic, and cryptoendolithic communities. A suite of previously unappreciated Antarctic microbial stress response pathways, thermal, osmotic, and nutrient limitation responses were identified and related to environmental stressors, offering tangible clues to the mechanisms behind the enduring success of microorganisms in this seemingly inhospitable terrain. Rocky substrates exposed to larger fluctuations in environmental stress supported greater functional diversity in stress-response pathways than soils. Soils comprised a unique reservoir of genes involved in transformation of organic hydrocarbons and lignin-like degradative pathways. This has major implications for the evolutionary origin of the organisms, turnover of recalcitrant substrates in Antarctic soils, and predicting future responses to anthropogenic pollution. PMID:23671121

  9. Functional ecology of an Antarctic Dry Valley.

    Science.gov (United States)

    Chan, Yuki; Van Nostrand, Joy D; Zhou, Jizhong; Pointing, Stephen B; Farrell, Roberta L

    2013-05-28

    The McMurdo Dry Valleys are the largest ice-free region in Antarctica and are critically at risk from climate change. The terrestrial landscape is dominated by oligotrophic mineral soils and extensive exposed rocky surfaces where biota are largely restricted to microbial communities, although their ability to perform the majority of geobiological processes has remained largely uncharacterized. Here, we identified functional traits that drive microbial survival and community assembly, using a metagenomic approach with GeoChip-based functional gene arrays to establish metabolic capabilities in communities inhabiting soil and rock surface niches in McKelvey Valley. Major pathways in primary metabolism were identified, indicating significant plasticity in autotrophic, heterotrophic, and diazotrophic strategies supporting microbial communities. This represents a major advance beyond biodiversity surveys in that we have now identified how putative functional ecology drives microbial community assembly. Significant differences were apparent between open soil, hypolithic, chasmoendolithic, and cryptoendolithic communities. A suite of previously unappreciated Antarctic microbial stress response pathways, thermal, osmotic, and nutrient limitation responses were identified and related to environmental stressors, offering tangible clues to the mechanisms behind the enduring success of microorganisms in this seemingly inhospitable terrain. Rocky substrates exposed to larger fluctuations in environmental stress supported greater functional diversity in stress-response pathways than soils. Soils comprised a unique reservoir of genes involved in transformation of organic hydrocarbons and lignin-like degradative pathways. This has major implications for the evolutionary origin of the organisms, turnover of recalcitrant substrates in Antarctic soils, and predicting future responses to anthropogenic pollution.

  10. Pelagic sea snakes dehydrate at sea.

    Science.gov (United States)

    Lillywhite, Harvey B; Sheehy, Coleman M; Brischoux, François; Grech, Alana

    2014-05-07

    Secondarily marine vertebrates are thought to live independently of fresh water. Here, we demonstrate a paradigm shift for the widely distributed pelagic sea snake, Hydrophis (Pelamis) platurus, which dehydrates at sea and spends a significant part of its life in a dehydrated state corresponding to seasonal drought. Snakes that are captured following prolonged periods without rainfall have lower body water content, lower body condition and increased tendencies to drink fresh water than do snakes that are captured following seasonal periods of high rainfall. These animals do not drink seawater and must rehydrate by drinking from a freshwater lens that forms on the ocean surface during heavy precipitation. The new data based on field studies indicate unequivocally that this marine vertebrate dehydrates at sea where individuals may live in a dehydrated state for possibly six to seven months at a time. This information provides new insights for understanding water requirements of sea snakes, reasons for recent declines and extinctions of sea snakes and more accurate prediction for how changing patterns of precipitation might affect these and other secondarily marine vertebrates living in tropical oceans.

  11. Pelagic sea snakes dehydrate at sea

    Science.gov (United States)

    Lillywhite, Harvey B.; Sheehy, Coleman M.; Brischoux, François; Grech, Alana

    2014-01-01

    Secondarily marine vertebrates are thought to live independently of fresh water. Here, we demonstrate a paradigm shift for the widely distributed pelagic sea snake, Hydrophis (Pelamis) platurus, which dehydrates at sea and spends a significant part of its life in a dehydrated state corresponding to seasonal drought. Snakes that are captured following prolonged periods without rainfall have lower body water content, lower body condition and increased tendencies to drink fresh water than do snakes that are captured following seasonal periods of high rainfall. These animals do not drink seawater and must rehydrate by drinking from a freshwater lens that forms on the ocean surface during heavy precipitation. The new data based on field studies indicate unequivocally that this marine vertebrate dehydrates at sea where individuals may live in a dehydrated state for possibly six to seven months at a time. This information provides new insights for understanding water requirements of sea snakes, reasons for recent declines and extinctions of sea snakes and more accurate prediction for how changing patterns of precipitation might affect these and other secondarily marine vertebrates living in tropical oceans. PMID:24648228

  12. Groundwater availability of the Central Valley Aquifer, California

    Science.gov (United States)

    Faunt, Claudia C.

    2009-01-01

    California's Central Valley covers about 20,000 square miles and is one of the most productive agricultural regions in the world. More than 250 different crops are grown in the Central Valley with an estimated value of $17 billion per year. This irrigated agriculture relies heavily on surface-water diversions and groundwater pumpage. Approximately one-sixth of the Nation's irrigated land is in the Central Valley, and about one-fifth of the Nation's groundwater demand is supplied from its aquifers. The Central Valley also is rapidly becoming an important area for California's expanding urban population. Since 1980, the population of the Central Valley has nearly doubled from 2 million to 3.8 million people. The Census Bureau projects that the Central Valley's population will increase to 6 million people by 2020. This surge in population has increased the competition for water resources within the Central Valley and statewide, which likely will be exacerbated by anticipated reductions in deliveries of Colorado River water to southern California. In response to this competition for water, a number of water-related issues have gained prominence: conservation of agricultural land, conjunctive use, artificial recharge, hydrologic implications of land-use change, and effects of climate variability. To provide information to stakeholders addressing these issues, the USGS Groundwater Resources Program made a detailed assessment of groundwater availability of the Central Valley aquifer system, that includes: (1) the present status of groundwater resources; (2) how these resources have changed over time; and (3) tools to assess system responses to stresses from future human uses and climate variability and change. This effort builds on previous investigations, such as the USGS Central Valley Regional Aquifer System and Analysis (CV-RASA) project and several other groundwater studies in the Valley completed by Federal, State and local agencies at differing scales. The

  13. Near-surface heat flow in Saline Valley, California

    Energy Technology Data Exchange (ETDEWEB)

    Mase, C.W.; Galanis, S.P. Jr.; Munroe, R.J.

    1979-01-01

    With the exception of values from one borehole drilled at Palm Spring and three boreholes drilled around Saline Valley dry lake, eight new heatflow values in Saline Valley, California, are within or somewhat below the range one would expect for this region of the Basin and Range heat-flow province. The lack of recent volcanism in the area and the apparently normal Basin and Range heat flow suggest that geothermal systems within the valley are stable stationary phases supported by high regional heat flow and forced convection.

  14. Valley-selective topologically ordered states in irradiated bilayer graphene

    Science.gov (United States)

    Qu, Chunlei; Zhang, Chuanwei; Zhang, Fan

    2018-01-01

    Gapless bilayer graphene is susceptible to a variety of spontaneously gapped states. As predicted by theory and observed by experiment, the ground state is, however, topologically trivial, because a valley-independent gap is energetically favorable. Here, we show that under the application of interlayer electric field and circularly polarized light, one valley can be selected to exhibit the original interaction instability while the other is frozen out. Tuning this Floquet system stabilizes multiple competing topologically ordered states, distinguishable by edge transport and circular dichroism. Notably, quantized charge, spin, and valley Hall conductivities coexist in one stabilized state.

  15. Holocene alluvial fills in the South Loup Valley, Nebraska

    Science.gov (United States)

    May, David W.

    1989-07-01

    Four Holocene alluvial fills are present in Nebraska's South Loup River valley. Fill IV, the oldest and thickest, was deposited between 10,200 and 4800 14C yr B.P.; Fill III has an age of about 3000 14C yr B.P.; Fill II is younger than 2100 and older than 900 14C yr B.P.; and Fill I is younger than 900 14C yr B.P. Regional contemporaneity of valley alluviation in the eastcentral Great Plains suggests that climate has controlled long-term sediment storage in the South Loup River valley.

  16. VALMET: a valley air pollution model. Final report. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Whiteman, C.D.; Allwine, K.J.

    1985-04-01

    An air quality model is described for predicting air pollution concentrations in deep mountain valleys arising from nocturnal down-valley transport and diffusion of an elevated pollutant plume, and the fumigation of the plume on the valley floor and sidewalls after sunrise. Included is a technical description of the model, a discussion of the model's applications, the required model inputs, sample calculations and model outputs, and a full listing of the FORTRAN computer program. 55 refs., 27 figs., 6 tabs.

  17. Pliocene and Pleistocene geologic and climatic evolution in the San Luis Valley of south-central Colorado

    Science.gov (United States)

    Rogers, K.L.; Larson, E.E.; Smith, G.; Katzman, D.; Smith, G.R.; Cerling, T.; Wang, Y.; Baker, R.G.; Lohmann, K.C.; Repenning, C.A.; Patterson, P.; Mackie, G.

    1992-01-01

    Sediments of the Alamosa Formation spanning the upper part of the Gauss and most of the Matuyama Chrons were recovered by coring in the high (2300 m) San Luis Valley of south-central Colorado. The study site is located at the northern end of the Rio Grande rift. Lithologic changes in the core sediments provide evidence of events leading to integration of the San Luis drainage basin into the Rio Grande. The section, which includes the Huckleberry Ridge Ash (2.02 Ma) and spans the entire Matuyama Chron, contains pollen, and invertebrate and vertebrate fossils. Stable isotope analyses of inorganic and biogenic carbonate taken over most of the core indicate substantially warmer temperatures than occur today in the San Luis Valley. At the end of the Olduvai Subchron, summer precipitation decreased, summer pan evaporation increased, and temperatures increased slightly compared to the earlier climate represented in the core. By the end of the Jaramillo Subchron, however, cold/wet and warm/dry cycles become evident and continue into the cold/wet regime associated with the deep-sea oxygen-isotope Stage 22 glaciation previously determined from outcrops at the same locality. Correspondence between the Hansen Bluff climatic record and the deep-sea oxygen-isotope record (oxygen-isotope stages from about 110-18) is apparent, indicating that climate at Hansen Bluff was responding to global climatic changes. ?? 1992.

  18. Sea surface temperatures and salinities from platforms in the Barents Sea, Sea of Japan, North Atlantic Ocean, Philippine Sea, Red Sea, and the South China Sea (Nan Hai) from 1896-1950 (NODC Accession 0000506)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Surface temperatures and salinities were collected in the Barents Sea, Sea of Japan, North Atlantic Ocean, Philippine Sea, Red Sea, and South China Sea (Nan Hai)...

  19. Geomorphology of outflow part Batova river valley

    Directory of Open Access Journals (Sweden)

    Vulcheva-Georgieva Ivalena

    2017-03-01

    Full Text Available Firths are geomoiphological and hydrological sites typical for flat, neutral coast of no tidal sea basins. There in the greatest extend is preserved the geological column of the correlative Pleistocene- Holocene sediments. They make possible to reveal the Quaternary evolution of the contact zone „land-sea“. Firths are one of the most reliable indicators for the Quaternary Earth crust movements.

  20. White Sea - Russia

    Science.gov (United States)

    2002-01-01

    At bottom center of this true-color Moderate Resolution Imaging Spectroradiometer (MODIS) image from April 13, 2001, the White Sea in western Russia is becoming free of ice in its southern extent. Meanwhile, the blue-green waters along the coast of the peninsula jutting out into the Barents Sea to the northeast could be due to a phytoplankton bloom.

  1. Sea Anemone: Investigations.

    Science.gov (United States)

    Hunt, John D.

    1982-01-01

    Several investigations can be undertaken with live sea anemones. A sea anemone's feeding response, fighting power, color, and symbiotic relationships to other invertebrates (such as a marine hermit crab) can be investigated in the high school classroom. Background information and laboratory procedures are provided. (Author/JN)

  2. Dilemmas in SEA application

    DEFF Research Database (Denmark)

    Lyhne, Ivar

    in the implementation of SEA in the sector, and they concern, e.g., strategic choices in transmission network development and ministerial choices on location of energy production units. The paper outlines the roots of the dilemmas as well as their implications for timing and content of SEA. The verdict is that we (in...

  3. California's Central Valley Groundwater Study: A Powerful New Tool to Assess Water Resources in California's Central Valley

    Science.gov (United States)

    Faunt, Claudia C.; Hanson, Randall T.; Belitz, Kenneth; Rogers, Laurel

    2009-01-01

    Competition for water resources is growing throughout California, particularly in the Central Valley. Since 1980, the Central Valley's population has nearly doubled to 3.8 million people. It is expected to increase to 6 million by 2020. Statewide population growth, anticipated reductions in Colorado River water deliveries, drought, and the ecological crisis in the Sacramento-San Joaquin Delta have created an intense demand for water. Tools and information can be used to help manage the Central Valley aquifer system, an important State and national resource.

  4. Black Sea in Bloom

    Science.gov (United States)

    2002-01-01

    This true-color image shows bright, turquoise-colored swirls across the surface of the Black Sea, signifying the presence of a large phytoplankton bloom. Scientists have observed similar blooms recurring annually, roughly this same time of year. The Sea of Azov, which is the smaller body of water located just north of the Black Sea in this image, also shows a high level of biological activity currently ongoing. The brownish pixels in the Azov are probably sediments carried in from high waters upstream. This scene was acquired by the Sea-viewing Wide Field-of-view Sensor (SeaWiFS), flying aboard the OrbView-2 satellite, on May 4, 2002. According to the Black Sea Environment Programme's Marine Hydrophysical Institute, the Black Sea is 'one of the marine areas of the world most damaged by human activities.' The coastal zone around these Eastern European inland water bodies is densely populated-supporting a permanent population of roughly 16 million people and another 4 million tourists each year. Six countries border with the Black Sea, including Ukraine to the north, Russia and Georgia to the east, Turkey to the south, and Bulgaria and Romania to the west. Because it is isolated from the world's oceans, and because there is an extensive drainage network of rivers that empty into it, the Black Sea has a unique and delicate water balance which is very important for supporting its marine ecosystem. Of particular concern to scientists is the salinity, water level, and nutrient levels of the Black Sea's waters, all of which are, unfortunately, being impacted by human activities. Within the last three decades the combination of increased nutrient loads from human sources together with pollution and over-harvesting of fisheries has resulted in a sharp decline in water quality. Scientists from each of the Black Sea's bordering nations are currently working together to study the issues and formulate a joint, international strategy for saving this unique marine ecosystem

  5. IOMASA SEA ICE DEVELOPMENTS

    DEFF Research Database (Denmark)

    Andersen, Søren; Tonboe, Rasmus; Heygster, Georg

    2005-01-01

    Sensitivity studies show that the radiometer ice concentration estimate can be biased by +10% by anomalous atmospheric emissivity and -20% by anomalous ice surface emissivity. The aim of the sea ice activities in EU 5th FP project IOMASA is to improve sea ice concentration estimates at higher...... spatial resolution. The project is in the process of facilitating an ice concentration observing system through validation and a better understanding of the microwave radiative transfer of the sea ice and overlying snow layers. By use of a novel modelling approach, it is possible to better detect...... and determine the circumstances that may lead to anomalous sea ice concentration retrieval as well as to assess and possibly minimize the sensitivities of the retrieval system. Through an active partnership with the SAF on Ocean and Sea Ice, a prototype system will be implemented as an experimental product...

  6. Bird Use of Imperial Valley Crops [ds427

    Data.gov (United States)

    California Department of Resources — Agriculture crops in the Imperial Valley of California provide valuable habitat for many resident and migratory birds and are a very important component of the...

  7. Canaan Valley National Wildlife Refuge Common Dragonflies and Damselflies

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Canaan Valley NWR is cooperating with the West Virginia Division of Natural Resources, Natural Heritage Program to inventory dragonflies and damselflies in an...

  8. Comparison of access to medicines between Klang Valley and East ...

    African Journals Online (AJOL)

    income of USD1/person/day) between urbanised Klang Valley and rural East Coast of Peninsular Malaysia. Methods: A semi-structured interview was conducted with caregivers to determine demographics, access to medicines, knowledge, ...

  9. Anuran Call Survey Summary 2006 Canaan Valley National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Anuran call surveys were conducted at Canaan Valley National Wildlife Refuge in April-June 2006 using the protocol developed by the North American Amphibian...

  10. Fishery Management Plan: Minnesota Valley National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Minnesota Valley National Wildlife Refuge (NWR) contains a limited fishery resource. Hogback Ponds, Round Lake, Bituminous Pond, and Blick Estate Stream have fishery...

  11. Law Enforcement Plan: Minnesota Valley National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Minnesota Valley NWR Law Enforcement Plan clarifies U.S. Fish and Wildlife enforcement policies as they apply to the Refuge. It provides information about...

  12. NPP Tropical Forest: Magdalena Valley, Colombia, 1970-1971

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: Biomass, litterfall, and nutrient content of above-ground vegetation and soil for a tropical seasonal evergreen forest at Magdalena Valley, Columbia,...

  13. Networking With Landscape: Local Initiatives in an Italian Alpine Valley

    National Research Council Canada - National Science Library

    Giorgio De Ros; Astrid Mazzola

    2012-01-01

    ...? To increase our understanding of these issues, an analysis was carried out by using the theoretical framework of the sociology of translation on 8 landscape-based initiatives in an Italian Alpine valley...

  14. Rock glacier inventory, Printse Valley, Valais, Switzerland, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — The Printse Valley is a 16-km-long north-orientated basin. The south-part (summits at 300 m asl) is glacierized. The intermediate sector, more continental, is very...

  15. Spin-valley splitting of electron beam in graphene

    Directory of Open Access Journals (Sweden)

    Yu Song

    2016-11-01

    Full Text Available We study spatial separation of the four degenerate spin-valley components of an electron beam in a EuO-induced and top-gated ferromagnetic/pristine/strained graphene structure. We show that, in a full resonant tunneling regime for all beam components, the formation of standing waves can lead sudden phase jumps ∼−π and giant lateral Goos-Hänchen shifts as large as the transverse beam width, while the interplay of the spin and valley imaginary wave vectors in the modulated regions can lead differences of resonant angles for the four spin-valley flavors, manifesting a spin-valley beam splitting effect. The splitting effect is found to be controllable by the gating and strain.

  16. A Statistical Model of Rift Valley Fever Activity in Egypt

    National Research Council Canada - National Science Library

    John M. Drake; Ali N. Hassan; John C. Beier

    2013-01-01

    Rift Valley fever (RVF) is a viral disease of animals and humans and a global public health concern due to its ecological plasticity, adaptivity, and potential for spread to countries with a temperate climate...

  17. Rappahannock River Valley National Wildlife Refuge: Comprehensive Conservation Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) was written to guide management on Rappahannock River Valley NWR for the next 15 years. This plan outlines the Refuge...

  18. Vernal Pool Complexes - Central Valley, 1989-1998 [ds36

    Data.gov (United States)

    California Department of Resources — This Arc/Info coverage is a polygon layer of vernal pool complexes greater than 40 acres in size for 29 counties throughout the greater Central Valley, and some...

  19. Groundwater discharge area for Diamond Valley, Central Nevada, 1968

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset represents "phreatophyte areas" mapped as part of an analysis of irrigation pumping in Diamond Valley, Nevada published in 1968. The data were digitized...

  20. Fire Management Plan Rappahannock River Valley National Wildlife Refuge 2009

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This plan for the Rappahannock River Valley National Wildlife Refuge will provide guidance on a wide range of fire management activities including preparedness,...

  1. Willamette Valley - Invasive Species Management with Volunteers 2010

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Volunteers worked with staff to survey for and treat 17 different invasive species within the Willamette Valley Refuges (Ankeny, Baskett Slough and William L....

  2. Stakeholder Evaluation for Canaan Valley National Wildlife Refuge : Completion Report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report provides a summary of results for the stakeholder evaluation conducted for Canaan Valley National Wildlife Refuge in winter 2006–2007. The purpose of...

  3. Willamette Valley - Invasive Species Management with Volunteers 2009

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Volunteers worked with staff to map and control invasive species within the Willamette Valley National Wildlife Refuge Complex refuges (William L. Finley, Ankeny,...

  4. San Joaquin Valley Aerosol Health Effects Research Center (SAHERC)

    Data.gov (United States)

    Federal Laboratory Consortium — At the San Joaquin Valley Aerosol Health Effects Center, located at the University of California-Davis, researchers will investigate the properties of particles that...

  5. Minnesota Valley National Wildlife Refuge annual narrative: Fiscal year 1997

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Minnesota Valley National Wildlife Refuge outlines Refuge accomplishments during the 1997 fiscal year. The report begins with an...

  6. Trip report (12-13 September 1995) - Canaan Valley NWR

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This reports describes recommendations for management practices at Canaan Valley National Wildlife Refuge. Topics include the following: deer herd management,...

  7. Minnesota Valley National Wildlife Refuge: Master Plan Amendment No. 1

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Master Plan developed for Minnesota Valley National Wildlife Refuge proposed that a refuge administration office and maintenance facility be located on an upland...

  8. Trip Report (November 29 - December 1, 2005) - Canaan Valley NWR

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Report describes suggestions for management alternatives to the Canaan Valley NWR. The major issues, or impediments to habitat management, that Sepik and Laskowski...

  9. Avian botulism in the southern San Joaquin valley 1970

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A joint effort of the Department of Fish and' Game and the U. S. Bureau of Sport Fisheries and Wildlife contained botulism losses in the southern San Joaquin Valley...

  10. The Trail Inventory of Coachella Valley NWR [Cycle 2

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The purpose of this report is to create a baseline inventory of all non-motorized trails on Coachella Valley National Wildlife Refuge. Trails in this inventory are...

  11. Steelhead Critical Habitat, Central Valley - NOAA [ds123

    Data.gov (United States)

    California Department of Resources — This layer depicts areas designated for Steelhead Critical Habitat as well as habitat type and quality in the California Central Valley Evolutionary Significant Unit...

  12. Chinook Critical Habitat, Central Valley - NOAA [ds125

    Data.gov (United States)

    California Department of Resources — This layer depicts areas designated for Chinook Critical Habitat as well as habitat type and quality in the Central Valley Spring-run Evolutionary Significant Unit...

  13. Stillwater Marsh and Lahontan Valley Wetlands Literature Review

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A review of known literature on Lahontan Valley marshlands was made by The Nature Conservancy in preparation for the Stillwater Water Management Analysis Scoping...

  14. Factors influencing immunisation coverage in Mathare Valley, Nairobi

    African Journals Online (AJOL)

    : Cross section destrictive study. Setting: Mathare valley slums in Central district of Nairobi, Kenya. Subjects: Seven hundred and twelve children aged 12-23 months. Results: Access to immunisation services was excellent at 95.6%. However ...

  15. Fire Management Plan Rappahannock River Valley National Wildlife Refuge 2009

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This plan for Rappahannock River Valley National Wildlife Refuge will provide guidance on a wide range of fire management activities including preparedness,...

  16. Adapting to Climate Change in Peru's Mantaro Valley | IDRC ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    The Mantaro Valley in central Peru is highly vulnerable to extreme weather events, such as droughts, floods, and frost. According to recent projections, this vulnerability will increase in coming years due to climate change.

  17. Wildlife Inventory Plan: Minnesota Valley National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The goals for this Wildlife Inventory Plan for Minnesota Valley NWR are: (1) to provide as good a survey method as possible to estimate population levels of key...

  18. Willamette Valley - Invasive Species Management with Volunteers 2012

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Volunteers worked with refuge staff to survey for and treat invasive species on the Willamette Valley Refuges (Ankeny, Baskett Slough and WL Finley NWR). False brome...

  19. An Introduction to the Black Sea Ecology

    Science.gov (United States)

    2001-01-01

    Balearic ( Iberian ) Sea, Ligurian Sea, Tyrrhenian Sea, Adriatic Sea, Ionic Sea, Aegean Sea, Sea of Marmara, and Levantine Sea. In its turn, in some...sheep-dog and other domestic dogs belong to one biological species that was raised 10–15,000 years ago from the wild species of wolf (Саnis lupus). The

  20. Geology and geomorphology of Bear Lake Valley and upper Bear River, Utah and Idaho

    Science.gov (United States)

    Reheis, M.C.; Laabs, B.J.C.; Kaufman, D.S.

    2009-01-01

    levels have decreased from as high as 1830 m to 1806 m above sea level since the early Pleistocene due to episodic downcutting by the Bear River. The oldest exposed lacustrine sediments in Bear Lake Valley are probably of Pliocene age. Several high-lake phases during the early and middle Pleistocene were separated by episodes of fluvial incision. Threshold incision was not constant, however, because lake highstands of as much as 8 m above bedrock threshold level resulted from aggradation and possibly landsliding at least twice during the late-middle and late Pleistocene. Abandoned stream channels within the low-lying, fault-bounded region between Bear Lake and the modern Bear River show that Bear River progressively shifted northward during the Holocene. Several factors including faulting, location of the fluvial fan, and channel migration across the fluvial fan probably interacted to produce these changes in channel position. Late Quaternary slip rates on the east Bear Lake fault zone are estimated by using the water-level history of Bear Lake, assuming little or no displacement on dated deposits on the west side of the valley. Uplifted lacustrine deposits representing Pliocene to middle Pleistocene highstands of Bear Lake on the footwall block of the east Bear Lake fault zone provide dramatic evidence of long-term slip. Slip rates during the late Pleistocene increased from north to south along the east Bear Lake fault zone, consistent with the tectonic geomorphology. In addition, slip rates on the southern section of the fault zone have apparently decreased over the past 50 k.y. Copyright ?? 2009 The Geological Society of America.

  1. Geology and ground-water resources of Ogden Valley, Utah

    Science.gov (United States)

    Leggette, R.M.; Taylor, G.H.

    1937-01-01

    Ogden Valley is a fault trough bounded on both the east and west by faults that dip toward the middle of the valley. This fault trough contains unconsolidated deposits of clay, sand, and gravel, whose thickness is more than 600 feet. These materials are stream and lake deposits and in places are well sorted and stratified. The lake sediments were laid down in a small lake that occupied Ogden Valley and that was connected with glacial Lake Bonneville at its high stage by an arm of water that occupied Ogden Canyon. During this stage of Lake Bonneville the Ogden Valley was completely filled with lake sediments up to an altitude of about 4,900 feet. These sediments include about 70 feet of clay, sand, and gravel in alternating layers, below which is a bed of varved clay whose maximum thickness is about 70 feet. This clay is continuous under the lower parts of the valley and is the confining bed that produces the artesian conditions. Below the varved clay is a deposit of silt, sand, and gravel of unknown thickness, most of which is believed to be pre-Bonneville alluvium.In most summers the streams entering Ogden Valley are diverted for irrigation, and the upper parts of their channels are generally dry during the irrigation season. Lower down in the valley seepage water appears in the channels, and below these points there is continuous flow. The flow of the Ogden River increases as it passes through Ogden Canyon. This gain in flow is believed to be derived chiefly from ground-water seepage from the canyon walls, although there is probably some groundwater underflow from Ogden Valley at the head of Ogden Canyon. Some of the gain is also due to leakage from pipe lines in the canyon.Of the 146 wells whose records are given in this report, 70 are flowing wells.

  2. Why do European companies have Innovation Hubs in Silicon Valley

    DEFF Research Database (Denmark)

    Berger, Andreas; Brem, Alexander

    2017-01-01

    Innovation hubs are gaining high attention in recent years, especially from European companies. Silicon Valley has been deemed as one of the most attractive and successful environments for establishing innovation hubs. This article highlights examples of companies from Europe that made the step t...... to California—namely, Volkswagen, Swisscom, BMW, Axel Springer, Munich Re, and Innogy SE (RWE Group). Based on these companies’ experiences, recommendations are given on how companies might approach a setup in Silicon Valley for long-term success....

  3. Seismicity related to geothermal development in Dixie Valley, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Ryall, A.S.; Vetter, U.R.

    1982-07-08

    A ten-station seismic network was operated in and around the Dixie Valley area from January 1980 to November 1981; three of these stations are still in operation. Data from the Dixie Valley network were analyzed through 30 Jun 1981, and results of analysis were compared with analysis of somewhat larger events for the period 1970-1979. The seismic cycle in the Western Great Basic, the geologic structural setting, and the instrumentation are also described.

  4. Comparison of Two Parametric Methods to Estimate Pesticide Mass Loads in California's Central Valley

    Science.gov (United States)

    Saleh, D.K.; Lorenz, D.L.; Domagalski, Joseph L.

    2011-01-01

    Mass loadings were calculated for four pesticides in two watersheds with different land uses in the Central Valley, California, by using two parametric models: (1) the Seasonal Wave model (SeaWave), in which a pulse signal is used to describe the annual cycle of pesticide occurrence in a stream, and (2) the Sine Wave model, in which first-order Fourier series sine and cosine terms are used to simulate seasonal mass loading patterns. The models were applied to data collected during water years 1997 through 2005. The pesticides modeled were carbaryl, diazinon, metolachlor, and molinate. Results from the two models show that the ability to capture seasonal variations in pesticide concentrations was affected by pesticide use patterns and the methods by which pesticides are transported to streams. Estimated seasonal loads compared well with results from previous studies for both models. Loads estimated by the two models did not differ significantly from each other, with the exceptions of carbaryl and molinate during the precipitation season, where loads were affected by application patterns and rainfall. However, in watersheds with variable and intermittent pesticide applications, the SeaWave model is more suitable for use on the basis of its robust capability of describing seasonal variation of pesticide concentrations. ?? 2010 American Water Resources Association. This article is a US Government work and is in the public domain in the USA.

  5. 3D View of Death Valley, California

    Science.gov (United States)

    2000-01-01

    This 3-D perspective view looking north over Death Valley, California, was produced by draping ASTER nighttime thermal infrared data over topographic data from the US Geological Survey. The ASTER data were acquired April 7, 2000 with the multi-spectral thermal infrared channels, and cover an area of 60 by 80 km (37 by 50 miles). Bands 13, 12, and 10 are displayed in red, green and blue respectively. The data have been computer enhanced to exaggerate the color variations that highlight differences in types of surface materials. Salt deposits on the floor of Death Valley appear in shades of yellow, green, purple, and pink, indicating presence of carbonate, sulfate, and chloride minerals. The Panamint Mtns. to the west, and the Black Mtns. to the east, are made up of sedimentary limestones, sandstones, shales, and metamorphic rocks. The bright red areas are dominated by the mineral quartz, such as is found in sandstones; green areas are limestones. In the lower center part of the image is Badwater, the lowest point in North America.Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, Calif., is the U.S. Science team leader; Moshe Pniel of JPL is the project manager. ASTER is the only high resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface.The broad spectral coverage and high spectral resolution of ASTER will provide

  6. Valley-selective optical Stark effect probed by Kerr rotation

    Science.gov (United States)

    LaMountain, Trevor; Bergeron, Hadallia; Balla, Itamar; Stanev, Teodor K.; Hersam, Mark C.; Stern, Nathaniel P.

    2018-01-01

    The ability to monitor and control distinct states is at the heart of emerging quantum technologies. The valley pseudospin in transition metal dichalcogenide (TMDC) monolayers is a promising degree of freedom for such control, with the optical Stark effect allowing for valley-selective manipulation of energy levels in WS2 and WSe2 using ultrafast optical pulses. Despite these advances, understanding of valley-sensitive optical Stark shifts in TMDCs has been limited by reflectance-based detection methods where the signal is small and prone to background effects. More sensitive polarization-based spectroscopy is required to better probe ultrafast Stark shifts for all-optical manipulation of valley energy levels. Here, we show time-resolved Kerr rotation to be a more sensitive probe of the valley-selective optical Stark effect in monolayer TMDCs. Compared to the established time-resolved reflectance methods, Kerr rotation is less sensitive to background effects. Kerr rotation provides a fivefold improvement in the signal-to-noise ratio of the Stark effect optical signal and a more precise estimate of the energy shift. This increased sensitivity allows for observation of an optical Stark shift in monolayer MoS2 that exhibits both valley and energy selectivity, demonstrating the promise of this method for investigating this effect in other layered materials and heterostructures.

  7. Assessment of Wastewater in Duhok Valley, Kurdistan Region/Iraq

    Directory of Open Access Journals (Sweden)

    Najmaldin E. Hassan

    2016-08-01

    Full Text Available In order to characterize the waste water in Duhok valley in Duhok governorate, during 25km, seven sites were selected in Duhok valley, to represent their water quality. Monthly samples were collected from the Duhok valley for the period from, April to September, 2015. The qualitative study of Duhok valley water tested, as considered one of the main sources of water pollution for Musol Lake. The physical and chemical test for water samples are taken from different locations in Duhok valley. To know the degree of pollution, and the impact of self-purification processes to improve water quality before arriving to the Mosul Lake, and the indicated results of the study a lack of dissolved oxygen in the water (DO. And high organic load values, (BOD and most of the bad qualities during water passage within the city of Duhok, while meat a significant improvement in the quality of water downstream before arriving at the dam Lake, is attributed to the effect of operations of self- purification ability of water. In spite of salinity problems and toxicity, the quality of water is suitable for irrigation crops on both sides of the valley .The all samples were tested for conductivity, TDS, pH, total hardness, chloride, alkalinity, sulfate, BOD, and phosphate, according to the standard methods.

  8. Antifan activism as a response to MTV's The Valleys

    Directory of Open Access Journals (Sweden)

    Bethan Jones

    2015-06-01

    Full Text Available MTV has launched several reality TV shows in the United Kingdom, but one, The Valleys (2012–14, about youth moving from the South Wales Valleys to Cardiff, has received much criticism. Grassroots criticism of the show arose, and a Valleys-centric campaign, The Valleys Are Here, took direct action. I adopt Jonathan Gray's definition of antifans to complicate ideas of fan activism. I utilize comments and posts made on the Valleys Are Here Twitter feed and Facebook account, as well as the organization's Web site, to examine the ways in which they encourage activism among antifans of the series. I pay particular attention to activist calls for MTV to be held accountable for its positioning of Wales and the Valleys, and to how it encourages participation among varied groups of people whose common denominator is their dislike of the series. Fan activism is not exclusive to people who consider themselves fans, and notions of fan activism can be complicated by drawing in antifans.

  9. Geothermal resource assessment of western San Luis Valley, Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Zacharakis, Ted G.; Pearl, Richard Howard; Ringrose, Charles D.

    1983-01-01

    The Colorado Geological Survey initiated and carried out a fully integrated assessment program of the geothermal resource potential of the western San Luis Valley during 1979 and 1980. The San Luis Valley is a large intermontane basin located in southcentral Colorado. While thermal springs and wells are found throughout the Valley, the only thermal waters found along the western part of the Valley are found at Shaw Warm Springs which is a relatively unused spring located approximately 6 miles (9.66 km) north of Del Norte, Colorado. The waters at Shaws Warm Spring have a temperature of 86 F (30 C), a discharge of 40 gallons per minute and contain approximately 408 mg/l of total dissolved solids. The assessment program carried out din the western San Luis Valley consisted of: soil mercury geochemical surveys; geothermal gradient drilling; and dipole-dipole electrical resistivity traverses, Schlumberger soundings, Audio-magnetotelluric surveys, telluric surveys, and time-domain electro-magnetic soundings and seismic surveys. Shaw Warm Springs appears to be the only source of thermal waters along the western side of the Valley. From the various investigations conducted the springs appear to be fault controlled and is very limited in extent. Based on best evidence presently available estimates are presented on the size and extent of Shaw Warm Springs thermal system. It is estimated that this could have an areal extent of 0.63 sq. miles (1.62 sq. km) and contain 0.0148 Q's of heat energy.

  10. Holocene evolution of a drowned melt-water valley in the Danish Wadden Sea

    DEFF Research Database (Denmark)

    Pedersen, Jørn Bjarke Torp; Svinth, Steffen; Bartholdy, Jesper

    2009-01-01

    a basal peat unit overlying sand of Weichselian age and glacio-fluvial origin. In its deepest part, the basal peat started to form around 8400 cal yr BP, and reached a thickness of up to 3.5 m. This thickness is about half of the original, when corrected for auto-compaction. The superimposed clay contains...... small (63-355 µm) red iron stains in the top and bottom units, and foraminifers of the calcareous type in the middle. The fact that iron stains and foraminifers in no cases coexist, but always exclude each other is interpreted as a result of the difference between salt-marsh facies (iron stains...

  11. The Expanded Owens Valley Solar Array

    Science.gov (United States)

    Gary, Dale E.; Hurford, G. J.; Nita, G. M.; White, S. M.; Tun, S. D.; Fleishman, G. D.; McTiernan, J. M.

    2011-05-01

    The Expanded Owens Valley Solar Array (EOVSA) is now under construction near Big Pine, CA as a solar-dedicated microwave imaging array operating in the frequency range 1-18 GHz. The solar science to be addressed focuses on the 3D structure of the solar corona (magnetic field, temperature and density), on the sudden release of energy and subsequent particle acceleration, transport and heating, and on space weather phenomena. The project will support the scientific community by providing open data access and software tools for analysis of the data, to exploit synergies with on-going solar research in other wavelengths. The New Jersey Institute of Technology (NJIT) is expanding OVSA from its previous complement of 7 antennas to a total of 15 by adding 8 new antennas, and will reinvest in the existing infrastructure by replacing the existing control systems, signal transmission, and signal processing with modern, far more capable and reliable systems based on new technology developed for the Frequency Agile Solar Radiotelescope (FASR). The project will be completed in time to provide solar-dedicated observations during the upcoming solar maximum in 2013 and beyond. We provide an update on current status and our preparations for exploiting the data through modeling and data analysis tools. This research is supported by NSF grants AST-0908344, and AGS-0961867 and NASA grant NNX10AF27G to New Jersey Institute of Technology.

  12. Calibrating Treasure Valley Groundwater Model using MODFLOW

    Science.gov (United States)

    Hernandez, J.; Tan, K.

    2016-12-01

    In Idaho, groundwater plays an especially important role in the state. According to the Idaho Department of Environmental Quality, groundwater supplies 95% of the state's drinking water (2011). The USGS estimates that Idaho withdraws 117 million cubic meters (95,000 acre-feet) per year from groundwater sources for domestic usage which includes drinking water. The same report from the USGS also estimates that Idaho withdraws 5,140 million cubic meters (4,170,000 acre-feet) per year from groundwater sources for irrigation usage. Quantifying and managing that resource and estimating groundwater levels in the future is important for a variety of socio-economic reasons. As the population within the Treasure Valley continues to grow, the demand of clean usable groundwater increases. The objective of this study was to develop and calibrate a groundwater model with the purpose of understanding short- and long-term effects of existing and alternative land use scenarios on groundwater changes. Hydrologic simulations were done using the MODFLOW-2000 model. The model was calibrated for predevelopment period by reproducing and comparing groundwater levels of the years before 1925 using steady state boundary conditions representing no change in the land use. Depending on the reliability of the groundwater source, the economic growth of the area can be constrained or allowed to flourish. Mismanagement of the groundwater source can impact its sustainability, quality and could hamper development by increasing operation and maintenance costs. Proper water management is critical because groundwater is such a limited resource.

  13. Fungal Biodiversity in the Alpine Tarfala Valley.

    Science.gov (United States)

    Coleine, Claudia; Selbmann, Laura; Ventura, Stefano; D'Acqui, Luigi Paolo; Onofri, Silvano; Zucconi, Laura

    2015-10-10

    Biological soil crusts (BSCs) are distributed worldwide in all semiarid and arid lands, where they play a determinant role in element cycling and soil development. Although much work has concentrated on BSC microbial communities, free-living fungi have been hitherto largely overlooked. The aim of this study was to examine the fungal biodiversity, by cultural-dependent and cultural-independent approaches, in thirteen samples of Arctic BSCs collected at different sites in the Alpine Tarfala Valley, located on the slopes of Kebnekaise, the highest mountain in northern Scandinavia. Isolated fungi were identified by both microscopic observation and molecular approaches. Data revealed that the fungal assemblage composition was homogeneous among the BSCs analyzed, with low biodiversity and the presence of a few dominant species; the majority of fungi isolated belonged to the Ascomycota, and Cryptococcus gilvescens and Pezoloma ericae were the most frequently-recorded species. Ecological considerations for the species involved and the implication of our findings for future fungal research in BSCs are put forward.

  14. Fungal Biodiversity in the Alpine Tarfala Valley

    Directory of Open Access Journals (Sweden)

    Claudia Coleine

    2015-10-01

    Full Text Available Biological soil crusts (BSCs are distributed worldwide in all semiarid and arid lands, where they play a determinant role in element cycling and soil development. Although much work has concentrated on BSC microbial communities, free-living fungi have been hitherto largely overlooked. The aim of this study was to examine the fungal biodiversity, by cultural-dependent and cultural-independent approaches, in thirteen samples of Arctic BSCs collected at different sites in the Alpine Tarfala Valley, located on the slopes of Kebnekaise, the highest mountain in northern Scandinavia. Isolated fungi were identified by both microscopic observation and molecular approaches. Data revealed that the fungal assemblage composition was homogeneous among the BSCs analyzed, with low biodiversity and the presence of a few dominant species; the majority of fungi isolated belonged to the Ascomycota, and Cryptococcus gilvescens and Pezoloma ericae were the most frequently-recorded species. Ecological considerations for the species involved and the implication of our findings for future fungal research in BSCs are put forward.

  15. Tennessee Valley Region: a year 2000 profile

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-06-01

    A study was undertaken to determine the potential radiological implications of nuclear facilities in the combined watersheds of the Tennessee and Cumberland rivers, an area covering portions of 7 states of varied topography. The regional population in 1970 was about 4.6 million and is expected to increase to about 7 million by the year 2000. A 1973 projection estimated the installed electric generating capacity of the region to increase from a 1970 value of 45,000 megawatts to a total of 222,000 megawatts by the year 2000. In that year, about 144,000 megawatts were projected to be nuclear plants. The profile of the Tennessee Valley Region in the year 2000, as drawn from this report, contains the essential data for calculation of the radiological dose from operation of nuclear facilities in that year. Those calculations are reported in the companion document, DOE/ET-0064/2. Specifically, Volume I establishes the parameters describing where the people live, what they eat, the activities in which they engage, and the environmental surroundings that enable an evaluation of the potential radiation dose to the population. Airborne radionuclides from nuclear facilities in this zone may enter the study area and be deposited on the ground, on growing food, and on water surfaces. Consideration was not given to waterborne radionuclides external to the study region. 17 references. (MCW)

  16. Soil formation in the Tsauchab Valley, Namibia

    Science.gov (United States)

    Eden, Marie; Bens, Oliver; Ramisch, Arne; Schwindt, Daniel; Völkel, Jörg

    2016-04-01

    The BMBF-funded project GeoArchives (Spaces) investigates soils and sediments in Southern Africa. A focus area lies on the Tsauchab Valley (Namibia), South of the Naukluft mountain range (24°26'40'' S, 16°10'40'' E). On a gently sloping alluvial fan facing East towards the river, the surface is characterized by a desert pavement covering soils used as farmland. The landscape units were mapped and the area at the lower slope of a hill was divided into three units: a rinsing surface and a gravel plain, separated by a channel. On these surfaces soil profiles were excavated. Profile description followed the German system (Bodenkundliche Kartieranleitung KA 5) and disturbed samples were taken at various depths and analysed in the lab. Undisturbed soil cores with a volume of 100 cm³ were taken just below the surface at a depth of ~1-6 cm. Lab analyses included texture and gravel content, colour, pH, electrical conductivity, carbonates, CNS, cation exchange capacity, pedogenic oxides, main and trace elements (XRF), and clay mineral distribution (XRD). Undisturbed samples were used to determine soil water retention curve, air permeability and bulk density. The profiles revealed moderately developed cambic soils rich in clay minerals and with total carbon contents ranging up to 1.8 %, bearing shrubs and after episodic rainfall a dense grass vegetation. Their genesis is discussed and interpreted in the context of the landscape and climate history of this semi-desert environment.

  17. The Role of Source Material in Basin Sedimentation, as Illustrated within Eureka Valley, Death Valley National Park, CA.

    Science.gov (United States)

    Lawson, M. J.; Yin, A.; Rhodes, E. J.

    2015-12-01

    Steep landscapes are known to provide sediment to sink regions, but often petrological factors can dominate basin sedimentation. Within Eureka Valley, in northwestern Death Valley National Park, normal faulting has exposed a steep cliff face on the western margin of the Last Chance range with four kilometers of vertical relief from the valley floor and an angle of repose of nearly 38 degrees. The cliff face is composed of Cambrian limestone and dolomite, including the Bonanza King, Carrara and Wood Canyon formations. Interacting with local normal faulting, these units preferentially break off the cliff face in coherent blocks, which result in landslide deposits rather than as finer grained material found within the basin. The valley is well known for a large sand dune, which derives its sediment from distal sources to the north, instead of from the adjacent Last Chance Range cliff face. During the Holocene, sediment is sourced primary from the northerly Willow Wash and Cucomungo canyon, a relatively small drainage (less than 80 km2) within the Sylvan Mountains. Within this drainage, the Jurassic quartz monzonite of Beer Creek is heavily fractured due to motion of the Fish Valley Lake - Death Valley fault zone. Thus, the quartz monzonite is more easily eroded than the well-consolidated limestone and dolomite that forms the Last Change Range cliff face. As well, the resultant eroded material is smaller grained, and thus more easily transported than the limestone. Consequently, this work highlights an excellent example of the strong influence that source material can have on basin sedimentation.

  18. Ozone pollution regimes modeled for a summer season in California’s San Joaquin Valley: A cluster analysis

    Science.gov (United States)

    Jin, Ling; Harley, Robert A.; Brown, Nancy J.

    2011-09-01

    This study demonstrates an application of cluster analysis to model simulation data for California's San Joaquin Valley (SJV) for the purpose of identifying meteorologically representative pollution regimes. Principal component analysis is employed to facilitate exploring and visualizing temporal variations in highly resolved gridded model data. Six regimes are clustered according to the spatial distribution of SJV 8 h ozone maxima. Meteorological effects (temperature and winds) are shown to explain the observed ozone spatial distributions in the SJV, and their relationship to those in upwind San Francisco Bay Area air basin (SFB) under certain prevailing wind flow patterns. In general, average ozone levels in the SJV increase with temperature, while their spatial distributions depend on flow regimes, especially the strength of sea breezes and upslope flows. More ventilated flow regimes, associated with stronger sea breeze and upslope flows, cause eastward transport of pollutants, increasing ozone in the southeastern SJV and decreasing it in the northwest SJV. The opposite occurs during the most stagnant conditions associated with the weakest sea breeze and upslope flows. The two most prominent relationships between the SFB and SJV were found to be associated with the most ventilated and the most stagnant conditions, respectively, indicating a strong inter-basin transport (or the lack thereof) event. Spatial representativeness of existing measurement sites and the confounding influences of emission changes on clustering results are also investigated. Existing measurement sites are able to capture ozone spatial patterns in the SFB and Sacramento Valley (SV), whereas those along the western side of the SJV are under-represented. Differences in day-of-week emissions produce minor effects on spatial ozone distributions and the clusters are largely stable under these changes.

  19. Agricultural Development, Land Change, and Livelihoods in Tanzania's Kilombero Valley

    Science.gov (United States)

    Connors, John Patrick

    The Kilombero Valley lies at the intersection of a network of protected areas that cross Tanzania. The wetlands and woodlands of the Valley, as well as the forest of surrounding mountains are abundant in biodiversity and are considered to be critical areas for conservation. This area, however, is also the home to more than a half million people, primarily poor smallholder farmers. In an effort to support the livelihoods and food security of these farmers and the larger Tanzanian population, the country has recently targeted a series of programs to increase agricultural production in the Kilombero Valley and elsewhere in the country. Bridging concepts and methods from land change science, political ecology, and sustainable livelihoods, I present an integrated assessment of the linkages between development and conservation efforts in the Kilombero Valley and the implications for food security. This dissertation uses three empirical studies to understand the process of development in the Kilombero Valley and to link the priorities and perceptions of conservation and development efforts to the material outcomes in food security and land change. The first paper of this dissertation examines the changes in land use in the Kilombero Valley between 1997 and 2014 following the privatization of agriculture and the expansion of Tanzania's Kilimo Kwanza program. Remote sensing analysis reveals a two-fold increase in agricultural area during this short time, largely at the expense of forest. Protected areas in some parts of the Valley appear to be deterring deforestation, but rapid agricultural growth, particularly surrounding a commercial rice plantation, has led to loss of extant forest and sustained habitat fragmentation. The second paper focuses examines livelihood strategies in the Valley and claims regarding the role of agrobiodiversity in food security. The results of household survey reveal no difference or lower food security among households that diversify their

  20. Simulation of the Aerosol-Atmosphere Interaction in the Dead Sea Area with COSMO-ART

    Science.gov (United States)

    Vogel, Bernhard; Bangert, Max; Kottmeier, Christoph; Rieger, Daniel; Schad, Tobias; Vogel, Heike

    2014-05-01

    The Dead Sea is a unique environment located in the Dead Sea Rift Valley. The fault system of the Dead Sea Rift Valley marks the political borders between Israel, Jordan, and Palestine. The Dead Sea region and the ambient Eastern Mediterranean coastal zone provide a natural laboratory for studying atmospheric processes ranging from the smallest scale of cloud processes to regional weather and climate. The virtual institute DESERVE is designed as a cross-disciplinary and cooperative international project of the Helmholtz Centers KIT, GFZ, and UFZ with well-established partners in Israel, Jordan and Palestine. One main focus of one of the work packages is the role of aerosols in modifying clouds and precipitation and in developing the Dead Sea haze layer as one of the most intriguing questions. The haze influences visibility, solar radiation, and evaporation and may even affect economy and health. We applied the online coupled model system COSMO-ART, which is able to treat the feedback processes between aerosol, radiation, and cloud formation, for a case study above the Dead Sea and adjacent regions. Natural aerosol like mineral dust and sea salt as well as anthropogenic primary and secondary aerosol is taken into account. Some of the observed features like the vertical double structure of the haze layer are already covered by the simulation. We found that absorbing aerosol like mineral dust causes a temperature increase in parts of the model domain. In other areas a decrease in temperature due to cirrus clouds modified by elevated dust layers is simulated.

  1. Sea Scallop Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The standardized NEFSC Sea Scallop Survey began in 1980 and has covered an area from Cape Hatteras to Georges Bank. The survey aims to determine the distribution and...

  2. Dead Sea Scrolls

    Science.gov (United States)

    1994-01-01

    A consortium of researchers from Jet Propulsion Laboratory and three other organizations used charged coupled devices (CCDs) and other imaging enhancement technology to decipher previously unreadable portions of the Dead Sea Scrolls. The technique has potentially important implications for archeology.

  3. Baltic Sea: Radionuclides

    DEFF Research Database (Denmark)

    Nielsen, Sven Poul; Lüning, Maria; Ilus, Erkki

    2010-01-01

    The most significant source of anthropogenic radioactivity in the Baltic Sea is fallout from the accident at the Chernobyl nuclear power plant in 1986. The second most important source is global fallout from atmospheric nuclear weapons tests carried out during the late 1950s and early 1960s....... Radioactivity inputs into the Baltic Sea from nuclear reprocessing plants in Western Europe have become of minor importance due to significant reduction of discharges in recent years. In terms of input of 137Cs into the Baltic Sea, Chernobyl fallout has contributed about 82% and nuclear weapons test fallout...... about 14%. For 90Sr in the Baltic Sea, input from atmospheric fallout from nuclear weapons tests has contributed about 81%, while the contribution from Chernobyl fallout was about 13%. Cesium-137 is the main indicator of Baltic seawater with respect to anthropogenic radioactivity. The highest...

  4. Baltic Sea: Radionuclides

    DEFF Research Database (Denmark)

    Nielsen, Sven Poul; Lüning, Maria; Ilus, Erkki

    2011-01-01

    The most significant source of anthropogenic radioactivity in the Baltic Sea is fallout from the accident at the Chernobyl nuclear power plant in 1986. The second most important source is global fallout from atmospheric nuclear weapons tests carried out during the late 1950s and early 1960s....... Radioactivity inputs into the Baltic Sea from nuclear reprocessing plants in Western Europe have become of minor importance due to significant reduction of discharges in recent years. In terms of input of 137Cs into the Baltic Sea, Chernobyl fallout has contributed about 82% and nuclear weapons test fallout...... about 14%. For 90Sr in the Baltic Sea, input from atmospheric fallout from nuclear weapons tests has contributed about 81%, while the contribution from Chernobyl fallout was about 13%. Cesium-137 is the main indicator of Baltic seawater with respect to anthropogenic radioactivity. The highest...

  5. Arctic Sea Level Reconstruction

    DEFF Research Database (Denmark)

    Svendsen, Peter Limkilde

    gauge record and makes the reconstruction much less prone to drifting away over time.Unfortunately, many of the Russian-sector tide gauge records end around 1990,leaving a fairly sparse record after this. This project examines the effect of introducing a subset of the altimetric dataset as “virtual tide......Reconstruction of historical Arctic sea level is very difficult due to the limited coverage and quality of tide gauge and altimetry data in the area. This thesis addresses many of these issues, and discusses strategies to help achieve a stable and plausible reconstruction of Arctic sea level from...... 1950 to today.The primary record of historical sea level, on the order of several decades to a few centuries, is tide gauges. Tide gauge records from around the world are collected in the Permanent Service for Mean Sea Level (PSMSL) database, and includes data along the Arctic coasts. A reasonable...

  6. Pollution of coastal seas

    Digital Repository Service at National Institute of Oceanography (India)

    Varkey, M.J.

    Pollution of various environments is a consequence of population growth and industrialisation. Coastal seas form part of marine environment and are very rich in minerals, crude oil fishes etc. They are also being used for disposal of wastes from...

  7. Sea Hero Quest.

    Science.gov (United States)

    2016-12-07

    Sea Hero Quest has been developed to help fight dementia. The mobile game is a collaboration between Alzheimer's Research UK and scientists from University College London and the University of East Anglia.

  8. South China Sea.

    Science.gov (United States)

    Morton, B; Blackmore, G

    2001-12-01

    The South China Sea is poorly understood in terms of its marine biota, ecology and the human impacts upon it. What is known is most often contained in reports and workshop and conference documents that are not available to the wider scientific community. The South China Sea has an area of some 3.3 million km2 and depths range from the shallowest coastal fringe to 5377 m in the Manila Trench. It is also studded with numerous islets, atolls and reefs many of which are just awash at low tide. It is largely confined within the Tropic of Cancer and, therefore, experiences a monsoonal climate being influenced by the Southwest Monsoon in summer and the Northeast Monsoon in winter. The South China Sea is a marginal sea and, therefore, largely surrounded by land. Countries that have a major influence on and claims to the sea include China, Malaysia, the Philippines and Vietnam, although Thailand, Indonesia and Taiwan have some too. The coastal fringes of the South China Sea are home to about 270 million people that have had some of the fastest developing and most vibrant economies on the globe. Consequently, anthropogenic impacts, such as over-exploitation of resources and pollution, are anticipated to be huge although, in reality, relatively little is known about them. The Indo-West Pacific biogeographic province, at the centre of which the South China Sea lies, is probably the world's most diverse shallow-water marine area. Of three major nearshore habitat types, i.e., coral reefs, mangroves and seagrasses, 45 mangrove species out of a global total of 51, most of the currently recognised 70 coral genera and 20 of 50 known seagrass species have been recorded from the South China Sea. The island groups of the South China Sea are all disputed and sovereignty is claimed over them by a number of countries. Conflicts have in recent decades arisen over them because of perceived national rights. It is perhaps because of this that so little research has been undertaken on the

  9. South China Sea

    Energy Technology Data Exchange (ETDEWEB)

    Morton, Brian [Hong Kong Univ., Swire Inst. of Marine Science, Hong Kong (China); Hong Kong Univ., Dept. of Ecology and Biodiversity, Hong Kong (China); Blackmore, Graham [Hong Kong Univ. of Science and Technology, Dept. of Biology, Hong Kong (China)

    2001-07-01

    The South China Sea is poorly understood in terms of its marine biota, ecology and the human impacts upon it. What is known is most often contained in reports and workshops and conference documents that are not available to the wider scientific community. The South China Sea has an area of some 3.3 million km{sup 2} and depths range from the shallowest coastal fringe to 5377m in the Manila Trench. It is also studded with numerous islets, atolls and reefs many of which are just awash at low tide. It is largely confined within the Tropic of Cancer and, therefore, experiences a monsoonal climate being influenced by the Southwest Monsoon in summer and the Northeast Monsoon in winter. The South China Sea is a marginal sea and, therefore, largely surrounded by land. Countries that have a major influence on and claims to the sea include China, Malaysia, the Philippines and Vietnam, although Thailand, Indonesia and Taiwan have some too. The coastal fringes of the South China Sea are home to about 270 million people that have had some of the fastest developing and most vibrant economics on the globe. Consequently, anthropogenic impacts, such as over-exploitation of resources and pollution, are anticipated to be huge although, in reality, relatively little is known about them. The Indo-West Pacific biogeographic province, at the centre of which the South China Sea lies, is probably the world's most diverse shallow-water marine area. Of three major nearshore habitat types, i.e., coral reefs, mangroves and seagrasses, 45 mangrove species out of a global total of 51, most of the currently recognised 70 coral genera and 20 of 50 known seagrass species have been recorded from the South China Sea. The island groups of the South China Sea are all disputed and sovereignty is claimed over them by a number of countries. Conflicts have in recent decades arisen over them because of perceived national rights. It is perhaps because of this that so little research has been undertaken

  10. South China Sea

    Science.gov (United States)

    Morton, Brian; Blackmore, Graham

    2001-01-01

    The South China Sea is poorly understood in terms of its marine biota, ecology and the human impacts upon it. What is known is most often contained in reports and workshop and conference documents that are not available to the wider scientific community. The South China Sea has an area of some 3.3 million km2 and depths range from the shallowest coastal fringe to 5377 m in the Manila Trench. It is also studded with numerous islets, atolls and reefs many of which are just awash at low tide. It is largely confined within the Tropic of Cancer and, therefore, experiences a monsoonal climate being influenced by the Southwest Monsoon in summer and the Northeast Monsoon in winter. The South China Sea is a marginal sea and, therefore, largely surrounded by land. Countries that have a major influence on and claims to the sea include China, Malaysia, the Philippines and Vietnam, although Thailand, Indonesia and Taiwan have some too. The coastal fringes of the South China Sea are home to about 270 million people that have had some of the fastest developing and most vibrant economies on the globe. Consequently, anthropogenic impacts, such as over-exploitation of resources and pollution, are anticipated to be huge although, in reality, relatively little is known about them. The Indo-West Pacific biogeographic province, at the centre of which the South China Sea lies, is probably the world's most diverse shallow-water marine area. Of the three major nearshore habitat types, i.e., coral reefs, mangroves and seagrasses, 45 mangrove species out of a global of 51, most of the currently recognised 70 coral genera and 20 of 50 known seagrass species have been recorded from the South China Sea. The island groups of the South China Sea are all disputed and sovereignty is claimed over them by a number of countries. Conflicts have in recent decades arisen over them because of perceived national rights. It is perhaps because of this that so little research has been undertaken on the South

  11. Lung cancer in the Kashmir valley

    Directory of Open Access Journals (Sweden)

    Koul Parvaiz

    2010-01-01

    Full Text Available Background: Lung cancer has been found to be the second commonest cancer according to a hospital-based data from Kashmir, India. However, no incidence studies are available. Objective: To ascertain the incidence of lung cancer in Kashmir. Materials and Methods: All newly histologically diagnosed cases of lung cancer seen in various hospital and private laboratories of the Kashmir valley were registered over a period of two years (January 1, 2004 to December 31, 2005. Also included were patients attending the various oncological service areas of the institute and those diagnosed from any other laboratory outside the state. The incidence rate was calculated using the January 2005 population as the reference population estimated using the census-based projected populations. Results: Four hundred and sixty-two incident cases of lung cancer were seen during the study period. The crude incidence rate, age standardized (world and truncated age adjusted (40-69 years, world incidence rates for lung cancer per 100 000 population were 4.01, 6.48 and 15.28 respectively (males 6.55, 10.09 and 23.94 respectively and females 1.19, 2.14 and 4.65. The age adjusted rates for males in district Srinagar was 19.34 per 100 000. One hundred and fifty nine (69.8% of the 221 had a history of Hukkah smoking. Conclusions: Even though Kashmir as a whole is a low incidence area for lung cancer (ASR of < 15, Srinagar district has the highest incidence of lung cancer among the males in Kashmir. The data presented is assumed to be the closest approximation to a population-based data registry and the geographical incidence maps of ICMR need appropriate updating

  12. The Evaporation Valley in the Kepler Planets

    Science.gov (United States)

    Owen, James E.; Wu, Yanqin

    2017-09-01

    A new piece of evidence supporting the photoevaporation-driven evolution model for low-mass, close-in exoplanets was recently presented by the California-Kepler Survey. The radius distribution of the Kepler planets is shown to be bimodal, with a “valley” separating two peaks at 1.3 and 2.6 R ⊕. Such an “evaporation valley” had been predicted by numerical models previously. Here, we develop a minimal model to demonstrate that this valley results from the following fact: the timescale for envelope erosion is the longest for those planets with hydrogen/helium-rich envelopes that, while only a few percent in weight, double its radius. The timescale falls for envelopes lighter than this because the planet’s radius remains largely constant for tenuous envelopes. The timescale also drops for heavier envelopes because the planet swells up faster than the addition of envelope mass. Photoevaporation therefore herds planets into either bare cores (˜1.3 R ⊕), or those with double the core’s radius (˜2.6 R ⊕). This process mostly occurs during the first 100 Myr when the stars’ high-energy fluxes are high and nearly constant. The observed radius distribution further requires the Kepler planets to be clustered around 3 M ⊕ in mass, born with H/He envelopes more than a few percent in mass, and that their cores are similar to the Earth in composition. Such envelopes must have been accreted before the dispersal of the gas disks, while the core composition indicates formation inside the ice line. Lastly, the photoevaporation model fails to account for bare planets beyond ˜30-60 days; if these planets are abundant, they may point to a significant second channel for planet formation, resembling the solar system terrestrial planets.

  13. The study of characteristics of Longitude Valley Fault derived from the dense continuous GPS array, southeastern Taiwan

    Science.gov (United States)

    Min-Chien, Tsai; Tzay-Chyn, Shin; Shui-Beih, Yu

    2016-04-01

    Taiwan is situated at the junction between the southeast-facing Ryukyu arc-trench system and the western-facing Luzon arc-Manila Trench system. The 150 km long, NNE-striking Longitudinal Valley Fault (LVF) in eastern Taiwan is an extremely active high-angle thrust fault. It bounds the Coastal Range and the Longitudinal Valley, which is considered a collision boundary between the Philippine Sea and the Eurasian plates. The Central Range is quite different geology structure from the Coastal Range. The Central Range is composed of the pre-Tertiary metamorphic basement and weakly metamorphosed Cenozoic argillite-slate series. The Coastal Range consist of Neogene andesitic volcanic units and associated turbidite sediments. The difference of those two geological provinces make LVF presents different characteristics in five different area. There are Hualien, Ruisui, Yuli, Chihshang, and Taitung area. In this study, we collect the continuous GPS data from a very dense array in the Longitudinal Valley area from 2009 to 2015 utilized to study the spatial variation of crustal motion along the LVF. With respect to Penghu station (S01R) in the Chinese continental margin, velocities for stations on the western side of the LVF (Longitudinal Valley and eastern Central Range) are 17-37 mm/yr in directions 280-312°, whereas those on the eastern side of the LVF, the Coastal Range, are 25-68 mm/yr in directions 300-325°. A major velocity discontinuity of about 20-25 mm/yr across the Longitudinal Valley is attributed to the aseismic slip along the LVF as revealed by trilateration data previously. The south of Fengping area, the velocity of Coastal Range is 30-40 mm/yr in 315-332° relative to the Central Range, while the near-fault motions are about 13-33 mm/yr in 309-336°. Various partitions on the left-lateral strike-slip and convergent components along the LVF are found. In the southern Longitudinal Valley crustal motion is mainly accommodated on the LVF and the Luyeh Fault. In

  14. Projecting future sea level

    Science.gov (United States)

    Cayan, Daniel R.; Bromirski, Peter; Hayhoe, Katharine; Tyree, Mary; Dettinger, Mike; Flick, Reinhard

    2006-01-01

    California’s coastal observations and global model projections indicate that California’s open coast and estuaries will experience increasing sea levels over the next century. Sea level rise has affected much of the coast of California, including the Southern California coast, the Central California open coast, and the San Francisco Bay and upper estuary. These trends, quantified from a small set of California tide gages, have ranged from 10–20 centimeters (cm) (3.9–7.9 inches) per century, quite similar to that estimated for global mean sea level. So far, there is little evidence that the rate of rise has accelerated, and the rate of rise at California tide gages has actually flattened since 1980, but projections suggest substantial sea level rise may occur over the next century. Climate change simulations project a substantial rate of global sea level rise over the next century due to thermal expansion as the oceans warm and runoff from melting land-based snow and ice accelerates. Sea level rise projected from the models increases with the amount of warming. Relative to sea levels in 2000, by the 2070–2099 period, sea level rise projections range from 11–54 cm (4.3–21 in) for simulations following the lower (B1) greenhouse gas (GHG) emissions scenario, from 14–61 cm (5.5–24 in) for the middle-upper (A2) emission scenario, and from 17–72 cm (6.7–28 in) for the highest (A1fi) scenario. In addition to relatively steady secular trends, sea levels along the California coast undergo shorter period variability above or below predicted tide levels and changes associated with long-term trends. These variations are caused by weather events and by seasonal to decadal climate fluctuations over the Pacific Ocean that in turn affect the Pacific coast. Highest coastal sea levels have occurred when winter storms and Pacific climate disturbances, such as El Niño, have coincided with high astronomical tides. This study considers a range of projected future

  15. Changes in extreme sea levels in the Baltic Sea

    Science.gov (United States)

    Dieterich, Christian; Gröger, Matthias; Andersson, Helén; Nerheim, Signild; Jönsson, Anette

    2016-04-01

    A newly developed shallow water model for the Baltic Sea and North Sea is presented. The model is validated by means of a comparison with hindcast simulations with observational data sets. The aim of the development is to provide and apply a modelling tool to model extreme sea levels in the Baltic Sea, Kattegat and Skagerrak. The model approach will support the direct analysis of extreme sea level observations in the past and provide the possibility to extend the statistical data base by producing very long time series or very large ensembles of coastal sea levels. This effort is intended to contribute to an assessment of risks due to storm surges and coastal flooding in the 21st century along the coast of Sweden. By using different RCP climate scenarios downscaled with a regional, coupled climate model atmospheric forcing is available to project possible changes in extreme sea levels into the future. Projected sea level rise, changes in dynamical sea level in the North East Atlantic and tidal forcing in the northern North Sea are applied as boundary condition which allows to investigate their impact on the dynamics of regional sea level variability. Initial experiments focus on the impact of model resolution, resolution in the atmospheric forcing and the amount of details necessary in the bathymetry to faithfully model coastal sea level in the Baltic Sea and North Sea.

  16. West Valley facility spent fuel handling, storage, and shipping experience

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, W.J.

    1990-11-01

    The result of a study on handling and shipping experience with spent fuel are described in this report. The study was performed by Pacific Northwest Laboratory (PNL) and was jointly sponsored by the US Department of Energy (DOE) and the Electric Power Research Institute (EPRI). The purpose of the study was to document the experience with handling and shipping of relatively old light-water reactor (LWR) fuel that has been in pool storage at the West Valley facility, which is at the Western New York Nuclear Service Center at West Valley, New York and operated by DOE. A subject of particular interest in the study was the behavior of corrosion product deposits (i.e., crud) deposits on spent LWR fuel after long-term pool storage; some evidence of crud loosening has been observed with fuel that was stored for extended periods at the West Valley facility and at other sites. Conclusions associated with the experience to date with old spent fuel that has been stored at the West Valley facility are presented. The conclusions are drawn from these subject areas: a general overview of the West Valley experience, handling of spent fuel, storing of spent fuel, rod consolidation, shipping of spent fuel, crud loosening, and visual inspection. A list of recommendations is provided. 61 refs., 4 figs., 5 tabs.

  17. Effects of valley meteorology on forest pesticide spraying

    Energy Technology Data Exchange (ETDEWEB)

    Whiteman, C.D.

    1990-04-01

    Pacific Northwest Laboratory conducted this study for the Missoula Technology and Development Center of the US Department of Agriculture's Forest Service. The purpose of the study was to summarize recent research on valley meteorology during the morning transition period and to qualitatively evaluate the effects of the evolution of valley temperature inversions and wind systems on the aerial spraying of pesticides in National Forest areas of the western United States. Aerial spraying of pesticides and herbicides in forests of the western United States is usually accomplished in the morning hour after first light, during the period known to meteorologists as the morning transition period.'' This document describes the key physical processes that occur during the morning transition period on undisturbed days and the qualitative effects of these processes on the conduct of aerial spraying operations. Since the timing of valley meteorological events may be strongly influenced by conditions that are external to the valley, such as strong upper-level winds or the influence of clouds on the receipt of solar energy in the valley, some remarks are made on the qualitative influence of these processes. Section 4 of this report suggests ways to quantify some of the physical processes to provide useful guidance for the planning and conduct of spraying operations. 12 refs., 9 figs.

  18. The environmental conditionings of the location of primeval settlements in the Wieprz River valley

    Science.gov (United States)

    Kozieł, Marcin; Kozieł, Wojciech

    2012-01-01

    The Wieprz River along the section currently occupied by the Nadwieprzański Landscape Park (NLP) constituted a convenient place of human settlement from the moment of retreat of the last ice sheet. Depending on the types of economy preferred by representatives of individual archaeological cultures, the river valley from Spiczyn to Dorohucza offered continuous access to water. This obviously gained additional importance from the moment of appearance of Neolithic cultures, particularly the Globular Amphora culture and Corded Ware culture with semi-nomadic style of life, dealing with breeding. Neolithic hunters-gatherers exploited the animal resources available in the river and its vicinity. The further role of fishing, i.e. providing a diet element or supplementation already in the conditions of agricultural-breeding economy, seems to be evidenced by findings of fishing hooks at Lusatian and Wielbark sites. Another factor affecting the location of settlements in NLP was also its close vicinity to the crops of the Rejowiec flint. According to archaeologists, this is particularly obvious in the case of the Late Palaeolithic and the turn of the Neolithic and Bronze Age. The communication function of the river could also be of importance: in the case of seasonal animal migrations of animals and hunters (Late Palaeolithic); livestock and shepherds (Globular Amphora culture and Corded Ware culture); or people alone (migration of the population of the Wielbark culture to the Red Sea). The fact that a commercial trail fragment was located along the Wieprz River is probably evidenced by the abundance of import from various parts of Europe at site 53 in Spiczyn. Fertile soils (black soils, silt-peat soils) prevailing in the valley also favoured the settlement of cultures with an agricultural-breeding model of economy, providing good conditions for horticulture. Meadows near the river could be used as pastures.

  19. Seasonal Creep on Longitudinal Valley Fault, Taiwan: Fault Hydrology before and after the 2003 Chengkung Earthquake

    Science.gov (United States)

    Randolph-Flagg, N. G.; Huang, M. H.; Lee, J. C.; Manga, M.; Mu, C. H.; Burgmann, R.

    2016-12-01

    We present hydrologic, geodetic, and seismic data on the Longitudinal Valley Fault (LVF) in eastern Taiwan- the plate boundary between the Eurasian plate and the Philippine Sea plate. Based on creepmeter data and Persistent Scatterer Interferometric Synthetic Aperture Radar (PSInSAR), most creep on the southern LVF (averaging 2 cm/yr) is seasonal with elastic strain building during the autumn/winter and released in creep events during the rainy spring/summer. Results from PSInSAR, GPS, and leveling suggest seasonal creep extends locally to > 200 m depth and we highlight the spatial distribution of this seasonal creep. The seasonality implies a relationship between hydrology (either through pore pressure diffusion or loading) and tectonic deformation. The timing of creep correlates with rain although the interannual variations in creep amplitude do not correlate with interannual changes in well levels or precipitation. This implies a more complicated coupling between hydrology and deformation within the fault zone. To understand the hydrologic process, we use a 2D poroelastic model to track pore fluid pressure changes within the fault zone to understand this seasonal behavior. We then use mud volcanoes and hot springs thermobarometers to further constrain the depth and rate of fluid flow around the Longitudinal Valley. We use these simulations to understand the fault zone hydrology when there are no significant earthquakes. Creep accelerated after the 2003 Mw 6.8 Chengkung Earthquake in SE Taiwan. Correcting for post-seismic afterslip, the amplitude of creep seasonality also increased for the three years after the earthquake suggesting a change in hydrologic properties. We compare changes in well levels and seismic velocity in the shallow crust near the LVF using ambient noise cross-correlation analysis to further understand these changes. The seasonal creep on the LVF and the dense geodetic, seismic, and hydrologic network make this a unique opportunity to probe

  20. Evaluation of model-based seasonal streamflow and water allocation forecasts for the Elqui Valley, Chile

    Science.gov (United States)

    Delorit, Justin; Cristian Gonzalez Ortuya, Edmundo; Block, Paul

    2017-09-01

    In many semi-arid regions, multisectoral demands often stress available water supplies. Such is the case in the Elqui River valley of northern Chile, which draws on a limited-capacity reservoir to allocate 25 000 water rights. Delayed infrastructure investment forces water managers to address demand-based allocation strategies, particularly in dry years, which are realized through reductions in the volume associated with each water right. Skillful season-ahead streamflow forecasts have the potential to inform managers with an indication of future conditions to guide reservoir allocations. This work evaluates season-ahead statistical prediction models of October-January (growing season) streamflow at multiple lead times associated with manager and user decision points, and links predictions with a reservoir allocation tool. Skillful results (streamflow forecasts outperform climatology) are produced for short lead times (1 September: ranked probability skill score (RPSS) of 0.31, categorical hit skill score of 61 %). At longer lead times, climatological skill exceeds forecast skill due to fewer observations of precipitation. However, coupling the 1 September statistical forecast model with a sea surface temperature phase and strength statistical model allows for equally skillful categorical streamflow forecasts to be produced for a 1 May lead, triggered for 60 % of years (1950-2015), suggesting forecasts need not be strictly deterministic to be useful for water rights holders. An early (1 May) categorical indication of expected conditions is reinforced with a deterministic forecast (1 September) as more observations of local variables become available. The reservoir allocation model is skillful at the 1 September lead (categorical hit skill score of 53 %); skill improves to 79 % when categorical allocation prediction certainty exceeds 80 %. This result implies that allocation efficiency may improve when forecasts are integrated into reservoir decision frameworks. The

  1. Mollusca, Hirudinea, and Amphibia biogeography and paleobiology in Tule Valley and adjacent regions of Bonneville Basin, western USA [draft

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Mollusk, leeches (Hirudinea), and amphibian distribution are described for Tule Valley and adjacent Snake Valley and Fish Springs Flat, Tule Valley aquatic resources...

  2. Winter sea ice export from the Laptev Sea preconditions the local summer sea ice cover

    Science.gov (United States)

    Krumpen, T.; Haas, C.; Itkin, P.

    2016-12-01

    Interannual variability and trends in sea ice export out of the Laptev Sea were investigated using a combination of observations and satellite data. The Laptev Sea shows a statistically positive trend in ice area export that is likely associated to an increase in ice drift velocity being the consequence of a thinning ice cover further north. Moreover, we could show that there is a high statistical connection of the late winter (Jan-May) sea ice export and ice formation in Laptev Sea polynyas to the summer sea ice concentration. By means of a sensitivity study using a coupled sea ice-ocean model (MITgcm), we could highlight the importance of winter sea ice processes for summer sea ice conditions in the Laptev Sea and likewise in the adjacent Siberian Seas. Years of high ice export have a thinning effect on the ice cover, which in turn preconditions early fast ice break up, pack ice melt and the occurrence of negative sea ice extent anomalies in summer. Our model simulation also indicate that observed increase in the sea ice export from the Laptev Sea is accompanied by an increase in the volume export, which is important for the Arctic sea ice budget.

  3. Preliminary hydrogeologic assessment near the boundary of the Antelope Valley and El Mirage Valley groundwater basins, California

    Science.gov (United States)

    Stamos, Christina L.; Christensen, Allen H.; Langenheim, Victoria

    2017-07-19

    The increasing demands on groundwater for water supply in desert areas in California and the western United States have resulted in the need to better understand groundwater sources, availability, and sustainability. This is true for a 650-square-mile area that encompasses the Antelope Valley, El Mirage Valley, and Upper Mojave River Valley groundwater basins, about 50 miles northeast of Los Angeles, California, in the western part of the Mojave Desert. These basins have been adjudicated to ensure that groundwater rights are allocated according to legal judgments. In an effort to assess if the boundary between the Antelope Valley and El Mirage Valley groundwater basins could be better defined, the U.S. Geological Survey began a cooperative study in 2014 with the Mojave Water Agency to better understand the hydrogeology in the area and investigate potential controls on groundwater flow and availability, including basement topography.Recharge is sporadic and primarily from small ephemeral washes and streams that originate in the San Gabriel Mountains to the south; estimates range from about 400 to 1,940 acre-feet per year. Lateral underflow from adjacent basins has been considered minor in previous studies; underflow from the Antelope Valley to the El Mirage Valley groundwater basin has been estimated to be between 100 and 1,900 acre-feet per year. Groundwater discharge is primarily from pumping, mostly by municipal supply wells. Between October 2013 and September 2014, the municipal pumpage in the Antelope Valley and El Mirage Valley groundwater basins was reported to be about 800 and 2,080 acre-feet, respectively.This study was motivated by the results from a previously completed regional gravity study, which suggested a northeast-trending subsurface basement ridge and saddle approximately 3.5 miles west of the boundary between the Antelope Valley and El Mirage Valley groundwater basins that might influence groundwater flow. To better define potential basement

  4. Perceptual discrimination difficulty and familiarity in the Uncanny Valley: more like a "Happy Valley".

    Science.gov (United States)

    Cheetham, Marcus; Suter, Pascal; Jancke, Lutz

    2014-01-01

    The Uncanny Valley Hypothesis (UVH) predicts that greater difficulty perceptually discriminating between categorically ambiguous human and humanlike characters (e.g., highly realistic robot) evokes negatively valenced (i.e., uncanny) affect. An ABX perceptual discrimination task and signal detection analysis was used to examine the profile of perceptual discrimination (PD) difficulty along the UVH' dimension of human likeness (DHL). This was represented using avatar-to-human morph continua. Rejecting the implicitly assumed profile of PD difficulty underlying the UVH' prediction, Experiment 1 showed that PD difficulty was reduced for categorically ambiguous faces but, notably, enhanced for human faces. Rejecting the UVH' predicted relationship between PD difficulty and negative affect (assessed in terms of the UVH' familiarity dimension), Experiment 2 demonstrated that greater PD difficulty correlates with more positively valenced affect. Critically, this effect was strongest for the ambiguous faces, suggesting a correlative relationship between PD difficulty and feelings of familiarity more consistent with the metaphor happy valley. This relationship is also consistent with a fluency amplification instead of the hitherto proposed hedonic fluency account of affect along the DHL. Experiment 3 found no evidence that the asymmetry in the profile of PD along the DHL is attributable to a differential processing bias (cf. other-race effect), i.e., processing avatars at a category level but human faces at an individual level. In conclusion, the present data for static faces show clear effects that, however, strongly challenge the UVH' implicitly assumed profile of PD difficulty along the DHL and the predicted relationship between this and feelings of familiarity.

  5. The Dead Sea

    Science.gov (United States)

    2006-01-01

    The Dead Sea is the lowest point on Earth at 418 meters below sea level, and also one of the saltiest bodies of water on Earth with a salinity of about 300 parts-per-thousand (nine times greater than ocean salinity). It is located on the border between Jordan and Israel, and is fed by the Jordan River. The Dead Sea is located in the Dead Sea Rift, formed as a result of the Arabian tectonic plate moving northward away from the African Plate. The mineral content of the Dead Sea is significantly different from that of ocean water, consisting of approximately 53% magnesium chloride, 37% potassium chloride and 8% sodium chloride. In the early part of the 20th century, the Dead Sea began to attract interest from chemists who deduced that the Sea was a natural deposit of potash and bromine. From the Dead Sea brine, Israel and Jordan produce 3.8 million tons potash, 200,000 tons elemental bromine, 45,000 tons caustic soda, 25, 000 tons magnesium metal, and sodium chloride. Both countries use extensive salt evaporation pans that have essentially diked the entire southern end of the Dead Sea. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining

  6. Estimating Vehicular Emission in Kathmandu Valley, Nepal

    Directory of Open Access Journals (Sweden)

    Krishna Prasad Ghimire

    2014-12-01

    Full Text Available The study estimate, the vehicular emission load for CO, CO2 , HCs, NOX, SO2, Dioxin/Furans, Particulate Matters (PM10, PM2.5, Black carbon and Organic Carbon by using emission factors and Global Warming Potentials (GWPs of the pollutants (CO2, NOX, BC and OC. For this purpose, data were collected through the video tape record (in 30 sites, questionnaire survey, field visit, and literatures review. The total estimated emission of Kathmandu Valley (KV was 7231053.12 ton/year. Of the total emission, CO2 emission was highest i.e., 91.01% followed by CO 5.03%, HC 0.96%, NOX 0.60%, PM10 0.18% and SO2 0.10%. Annually 529353.36 μg Toxic Equivalent (TEQ of Dioxin/Furan produced and directly disperse to the ambient environment. The total estimated PM2.5, BC and OC emission were 9649.40 ton/year, 1640.4 ton/year and 2894.82 ton/year. The total carbon equivalence of the combined emissions (CO2, NOX and BC for 100-years standard time horizon is 10579763.6 ton CO2-eq i.e., 2885390.07 ton carbon.CO2 alone will be responsible, for about 62% of the impacts for the next century from current emissions of CO2, NOX and BC. Of the total emission Heavy Duty Vehicles (HDV emits 50%, Light Duty Vehicles (LDV emits, 27%, 2-Wheelers emits 22% and 3-Wheeler (Tempo emits 1%. The total emission of all pollutants combined per vehicle together was estimated to be 5.46 ton/year which was estimated as 23.63, 10.35, 1.83 and 5.58 ton/year for HDV, LDV, 2-Wheelers and 3-Wheeler respectively. DOI: http://dx.doi.org/10.3126/ije.v3i4.11742      International Journal of EnvironmentVolume-3, Issue-4, Sep-Nov 2014Page: 133-146 

  7. Rivers and valleys of Pennsylvania, revisited

    Science.gov (United States)

    Morisawa, Marie

    1989-09-01

    The 1889 paper by William Morris Davis on the "Rivers and Valleys of Pennsylvania" is a landmark in the history of geomorphology. It was in this manuscript that he set forth what came to be known as the Davisian system of landscape. It is important to understand that Davis' interpretation of landforms was restricted by the geologic paradigms of his day. Uniformitarianism was strongly entrenched and Darwin's theory of evolution had become popularly accepted. The concept of the landmass Appalachia and then current theories on mountain building affected the approach that Davis took in hypothesizing the origin and development of the Folded Appalachian drainage. All of these geologic precepts influenced the formulation and explanation of his theories. In his exposition he adapted, synthesized and embellished on ideas he derived from fellow geologists such as Gilbert, Dutton, Powell, and McGee. A number of the concepts he proposed in the 1889 paper quickly became the bases for geomorphic studies by others: the cycles of river erosion and landscape evolution and the peneplain (here called base level erosion). The cycle of erosion became the model for subsequent geomorphic analyses, and peneplain hunting became a popular sport for geomorphologists. Davis' hypothesis of the origin and development of Pennsylvanian drainage stimulated subsequent discussion and further hypotheses by others. In fact, many of the later theories were refinements and/or elaborations of ideas mentioned in this paper of Davis. He proposed the origin of the drainage as consequent streams, then antecedence, superposition, headward extension of divides by piracy, erosion along lines of weaknesses (faults, easily erodible beds) through resistant ridges and normal fluvial erosion. Thus, the hypotheses of regional superposition (Johnson), extended consequents (Ruedemann), consequents and local superposition (Meyerhoff and Olmstead), the utilization of structural weaknesses in development of transverse

  8. Technical Analysis of In-Valley Drainage Management Strategies for the Western San Joaquin Valley, California

    Science.gov (United States)

    Presser, Theresa S.; Schwarzbach, Steven E.

    2008-01-01

    The western San Joaquin Valley is one of the most productive farming areas in the United States, but salt-buildup in soils and shallow groundwater aquifers threatens this area?s productivity. Elevated selenium concentrations in soils and groundwater complicate drainage management and salt disposal. In this document, we evaluate constraints on drainage management and implications of various approaches to management considered in: *the San Luis Drainage Feature Re-Evaluation (SLDFRE) Environmental Impact Statement (EIS) (about 5,000 pages of documentation, including supporting technical reports and appendices); *recent conceptual plans put forward by the San Luis Unit (SLU) contractors (i.e., the SLU Plans) (about 6 pages of documentation); *approaches recommended by the San Joaquin Valley Drainage Program (SJVDP) (1990a); and *other U.S. Geological Survey (USGS) models and analysis relevant to the western San Joaquin Valley. The alternatives developed in the SLDFRE EIS and other recently proposed drainage plans (refer to appendix A for details) differ from the strategies proposed by the San Joaquin Valley Drainage Program (1990a). The Bureau of Reclamation (USBR) in March 2007 signed a record of decision for an in-valley disposal option that would retire 194,000 acres of land, build 1,900 acres of evaporation ponds, and develop a treatment system to remove salt and selenium from drainwater. The recently proposed SLU Plans emphasize pumping drainage to the surface, storing approximately 33% in agricultural water re-use areas, treating selenium through biotechnology, enhancing the evaporation of water to concentrate salt, and identifying ultimate storage facilities for the remaining approximately 67% of waste selenium and salt. The treatment sequence of reuse, reverse osmosis, selenium bio-treatment, and enhanced solar evaporation is unprecedented and untested at the scale needed to meet plan requirements. All drainage management strategies that have been proposed

  9. Understanding the paleo environment in the Danish North Sea using 2D and 3D seismic analyses

    Science.gov (United States)

    Prins, Lasse K.; Clausen, Ole R.; Andresen, Katrine J.

    2017-04-01

    This study presents the first detailed and integrated mapping of buried Quaternary valleys, river systems and iceberg scourings from the Danish North Sea region. The mapped features coincide spatially but have very different characteristics and incision levels which allow us to constrain their relative timing and differentiate their environment of formation (subglacial, proglacial and marine). The results of the study bring new critical information regarding the paleoenvironment of the North Sea Basin during the latest Quaternary deglaciation period and our analysis provide a well-tested workflow for utilizing 2D and 3D seismic data in relation to paleogeographical reconstructions. Our analysis is based on interpretation of conventional 3D seismic and high-resolution sparker data from the Southern Danish Central Graben. The project forms part of the portfolio for the 'Danish Hydrocarbon Research and Technology Centre' and aims at building a high-resolution 3D geological-geotechnical model of the shallow subsurface by using geophysical data combined with geological and geotechnical data from shallow borings. One of the objectives is to map potential geohazards for offshore installations such as buried valleys and constrain their geotechnical properties. The central North Sea is known to have been covered by glaciers several times during the Quaternary with climate changing between arctic and boreal. Marine conditions periodically prevailed and large river systems mainly from central Europe dominated during periods of subaerial exposure. Hence, many buried erosional incisions, primarily tunnel valleys but also river systems, can be observed within the upper 200-400 meters of the Quaternary succession throughout the central North Sea region. A high-resolution mapping of the infill of the tunnel valleys and river systems have however not previously been presented. Our analysis shows that within the study area at least four generations of tunnel valley formation and

  10. Reflection Seismic Imaging of Buried Valleys, Onshore Denmark

    Science.gov (United States)

    Lykke-Andersen, H.; Jørgensen, F.; Nørmark, E.

    The steadily increasing demands for securing supplies of clean groundwater have in recent years led to the adoption of reflection seismics in the family of geophysical methods used for groundwater research in Denmark. Buried valleys- often some km wide and a few hundred metres deep - have proved to be important sites for deeply seated, well protected groundwater reservoirs. It is a well known fact that the structure of buried valleys is complicated. With their potential for generation of relatively high resolution images of depositional and tectonic structures, reflection seismics have be- come a valuable supplement to the traditional resistivity methods in the study of buried valleys. Reflection seismic is an expensive method compared to other methods in use for groundwater research; therefore, careful selection of profile locations is mandatory. A practice has developed where selection of locations are based on mapping results obtained by resistivity methods. Results obtained by dynamite and vibrator sources are presented. Experience shows that the quality of the two data types is comparable. Vertical resolution better than ca. 10 m can be obtained, but the bandwidth of data is variable. In areas where non-(water) saturated shallow sediments are present; the bandwidth may be strongly reduced. Depth penetration down to at least one km is normally obtained. The seismic data are tied to wells by means of vertical seismic profiles in exploratory wells. Results are presented to illustrate: 1) potentials and limi- tations of the method and 2) a number of valleys with different types of valley-fill and relationships with the substratum. The genesis of the valleys will be briefly discussed.

  11. Surface-Water Network for the Central Valley Hydrologic Model (CVHM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset contains the surface-water network for the Central Valley Hydrologic Model (CVHM). The Central Valley encompasses an approximate...

  12. Monthly Diversions from the Surface-Water Network of the Central Valley Hydrologic Model (CVHM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset contains the monthly diversions from the surface-water network for the Central Valley Hydrologic Model (CVHM). The Central Valley encompasses an...

  13. 76 FR 54251 - Central Valley Project Improvement Act, Water Management Plans

    Science.gov (United States)

    2011-08-31

    ... Bureau of Reclamation Central Valley Project Improvement Act, Water Management Plans AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of availability. SUMMARY: The following Water Management Plans are... Central Valley Project water conservation best management practices that shall ``develop criteria for...

  14. 75 FR 70020 - Central Valley Project Improvement Act, Water Management Plans

    Science.gov (United States)

    2010-11-16

    ... Bureau of Reclamation Central Valley Project Improvement Act, Water Management Plans AGENCY: Bureau of Reclamation, Interior ACTION: Notice of Availability. SUMMARY: The following Water Management Plans are... on Central Valley Project water conservation best management practices that shall ``* * * develop...

  15. EPA Region 1 - Map Layers for Valley ID Tool (Hosted Feature Service)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Valley Service Feature Layer hosts spatial data for EPA Region 1's Valley Identification Tool. These layers contain attribute information added by EPA R1 GIS...

  16. Grid cells used for Surface-Water Network for the Central Valley Hydrologic Model

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset contains the segment and reaches for the surface-water network by model cell for the Central Valley Hydrologic Model (CVHM). The Central Valley...

  17. Monthly Precipitation Input Data for the Central Valley Hydrologic Model (CVHM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset contains the monthly precipitation for the Central Valley Hydrologic Model (CVHM). The Central Valley encompasses an approximate 50,000...

  18. Monthly inflows to the surface-water network for the Central Valley Hydrologic Model (CVHM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset contains the monthly inflows to the surface-water network for the Central Valley Hydrologic Model (CVHM). The Central Valley encompasses an...

  19. Streamflow-gain- and streamflow-loss data for streamgages in the Central Valley Hydrologic Model

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset contains 61 sets of annual streamflow gains and losses between 1961 and 1977 along Central Valley surface-water network for the Central Valley...

  20. Location of 24 extensometers used to measure compaction in the Central Valley

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset describes the location of 21 extensometers used for observations of subsidence in the Central Valley Hydrologic Model (CVHM). The Central Valley...

  1. Virtual wells used for pumpage for the Central Valley Hydrologic Model (CVHM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Abstract: This digital dataset contains the virtual wells used for pumpage for the Central Valley Hydrologic Model (CVHM). The Central Valley encompasses an...

  2. West Valley Demonstration Project Annual Site Environmental Report Calendar Year 2004

    Energy Technology Data Exchange (ETDEWEB)

    West Valley Nuclear Services Company (WVNSCO) and URS Group, Inc.

    2005-09-30

    Annual Site Environmental Report for the West Valley Demonstration Project (WVDP) for Calendar Year 2004. The report summarizes the environmental protection program at the West Valley Demonstration Project for CY 2004.

  3. Inflow Locations and Magnitude Input Files to the Central Valley Hydrologic Model (CVHM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset contains the name and location for the inflows to the surface-water network for the Central Valley Hydrologic Model (CVHM). The Central Valley...

  4. Giant and tunable valley degeneracy splitting in MoTe2

    Science.gov (United States)

    Li, Xiao; Qi, Jingshan; Niu, Qian; Feng, Ji

    Valleys in monolayer transition-metal dichalcogenides seamlessly connect two basic carriers of quantum information, namely, the electron spin and photon helicity. Lifting the valley degeneracy is an attractive route to achieve further optoelectronic manipulations. However, the magnetic field only creates a very small valley splitting. We propose a strategy to create giant valley splitting by the proximity-induced Zeeman effect. Our first principles calculations of monolayer MoTe2 on a EuO substrate show that valley splitting over 300 meV can be generated. Interband transition energies become valley dependent, leading to selective spin-photon coupling by optical frequency tuning. The valley splitting is also continuously tunable by rotating the substrate magnetization. The giant and tunable valley splitting adds a different dimension to the exploration of unique optoelectronic devices based on magneto-optical coupling and magnetoelectric coupling.

  5. How Silicon Valley Journalists Talk about: Independence in Innovation Coverage

    DEFF Research Database (Denmark)

    Mogensen, Kirsten; Nordfors, David

    2010-01-01

    Silicon Valley has become known for innovations that have led to substantial changes for citizens around the world. In 1960s’-80s’ the innovation had to do with computers and electronics, 1990s-00s’ it was on Internet and Web services. Since the later part of the 00’s, clean tech has emerged......-structured interviews with journalists who cover the innovation economy in Silicon Valley, the paper seeks to understand the professional challenges the network structure create for journalists and the strategies they apply. Comparing the results with previous research in journalism norms, this study suggests...

  6. Summary Robert Noyce and the invention of Silicon Valley

    CERN Document Server

    2014-01-01

    This work offers a summary of the book "THE MAN BEHIND THE MICROCHIP: Robert Noyce and the Invention of Silicon Valley""by Leslie Berlin.The Man behind the Microchip is Leslie Berlin's first book. This author is project historian for the Silicon Valley Archives, a division of the Stanford University Department of Special Collections. This book tells the story of a giant of the high-tech industry: the multimillionaire Bob Noyce. This co-founder of Fairchild Semiconductor and Intel co-invented the integrated circuit which became the electronic heart of every modern computer, automobile, advance

  7. Hydrogeology of the carbonate rocks of the Lebanon Valley, Pennsylvania

    Science.gov (United States)

    Meisler, Harold

    1963-01-01

    The Lebanon Valley, which is part of the Great Valley in southeastern Pennsylvania, is underlain by carbonate rocks in the southern part and by shale in the northern part. The carbonate rocks consist of alternating beds of limestone and dolomite of Cambrian and Ordovician age. Although the beds generally dip to the south, progressively younger beds crop out to the north, because the rocks are overturned. The stratigraphic units, from oldest to youngest, are: the Buffalo Springs Formation, Snitz Creek, Schaefferstown, Millbach, and Richland Formations of the Conococheague Group; the Stonehenge, Rickenbach, Epler, and Ontelaunee Formations of the Beekmantown Group; and the Annville, Myerstown, and Hershey Limestones.

  8. Vitrification facility at the West Valley Demonstration Project

    Energy Technology Data Exchange (ETDEWEB)

    DesCamp, V.A.; McMahon, C.L.

    1996-07-01

    This report is a description of the West Valley Demonstration Project`s vitrification facilities from the establishment of the West Valley, NY site as a federal and state cooperative project to the completion of all activities necessary to begin solidification of radioactive waste into glass by vitrification. Topics discussed in this report include the Project`s background, high-level radioactive waste consolidation, vitrification process and component testing, facilities design and construction, waste/glass recipe development, integrated facility testing, and readiness activities for radioactive waste processing.

  9. Valley fill in the Roswell-Artesia area, New Mexico

    Science.gov (United States)

    Lyford, Forest P.

    1973-01-01

    Drill samples from 225 water and oil wells in an area 70 miles long and 20 miles wide in the Roswell-Artesia area, southeastern New Mexico were examined. A thickness map and a saturated thickness map of the valley-fill sediments were constructed. Maximum depth of valley fill is about 300 feet in large closed depressions near Roswell, Hagerman, and Artesia. The depressions were formed by the solution of carbonates and evaporites that underlie the fill. Maximum saturated thickness is about 250 feet in depressions near Hagerman and Artesia and about 300 feet in a depression near Roswell.

  10. West Valley Demonstration Project site environmental report, calendar year 1997

    Energy Technology Data Exchange (ETDEWEB)

    None

    1998-06-01

    This report represents a single, comprehensive source of off-site and on-site environmental monitoring data collected during 1997 by environmental monitoring personnel for the West Valley Demonstration Project (WVDP), West Valley, New York. The environmental monitoring program and results are discussed in the body of this report. The monitoring data are presented in the appendices. The data collected provide an historical record of radionuclide and radiation levels from natural and manmade sources in the survey area and document the quality of the groundwater on and around the WVDP and the quality of the air and water discharged by the WVDP.

  11. West Valley Demonstration Project site environmental report calendar year 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-06-01

    This report represents a single, comprehensive source of off-site and on-site environmental monitoring data collected during 1998 by environmental monitoring personnel for the West Valley Demonstration Project (WVDP), West Valley, New York. The environmental monitoring program and results are discussed in the body of this report. The monitoring data are presented in the appendices. The data collected provide an historical record of radionuclide and radiation levels from natural and manmade sources in the survey area and document the quality of the groundwater on and around the WVDP and the quality of the air and water discharged by the WVDP.

  12. West Valley Demonstration Project site environmental report, calendar year 1999

    Energy Technology Data Exchange (ETDEWEB)

    None Available

    2000-06-01

    This report represents a single, comprehensive source of off-site and on-site environmental monitoring data collected during 1999 by environmental monitoring personnel for the West Valley Demonstration Project (WVDP), West Valley, New York. The environmental monitoring program and results are discussed in the body of this report. The monitoring data are presented in the appendices. The data collected provide an historical record of radionuclide and radiation levels from natural and manmade sources in the survey area and document the quality of the groundwater on and around the WVDP and the quality of the air and water discharged by the WVDP.

  13. A skin test survey of valley fever in Tijuana, Mexico.

    Science.gov (United States)

    Fredrich, B E

    1989-01-01

    Results of a study of the prevalence of valley fever among 1128 residents of Tijuana, Baja California are presented. Children from primary and middle schools (n = 497) and adults from technical institutes and maquiladoras (assembly plants) were tested for reaction to both spherulin and coccidioidin during 1985-1986, and they completed a questionnaire containing 23 variables on their socio-environment. Place of residence was mapped. The population sampled is largely middle class. Discriminant analysis indicates the distribution of positive cases is not clustered, nor can it be correlated with geomorphic factors such as mesa tops, canyons, or valley bottoms.

  14. Inca expansion and parasitism in the lluta valley: preliminary data.

    Science.gov (United States)

    Santoro, Calogero; Vinton, Sheila Dorsey; Reinhard, Karl J

    2003-01-01

    Assessing the impact of cultural change on parasitism has been a central goal in archaeoparasitology. The influence of civilization and the development of empires on parasitism has not been evaluated. Presented here is a preliminary analysis of the change in human parasitism associated with the Inca conquest of the Lluta Valley in Northern Chile. Changes in parasite prevalence are described. It can be seen that the change in life imposed on the inhabitants of the Lluta Valley by the Incas caused an increase in parasitism.

  15. Mediterranean, our sea

    Science.gov (United States)

    Markaki, Foteini

    2017-04-01

    My school (1o EPAL Ymittos -Athens, Greece) is a technical school of secondary education and throughout this school year being drafted a program of environmental education. The main theme is the Mediterranean Sea, the biggest closed sea extending between three continents. Topics studied: 1. Biodiversity and the risks threat. 2. The geophysics that characterize (earthquakes, volcanoes explosions, etc). 3. The Mediterranean Sea as environment anthropogenesis, a mosaic of other cultures and even place current notions of social phenomena (refugees). Pedagogical Objectives: Cognitive/Enviromental: 1. To investigate and understand the biodiversity of the Mediterranean Sea and the risks to threaten and phenomena that characterize. 2. To understand the position of the Mediterranean Sea in the land and the role of the historical, cultural and social human environment. 3. To come in contact with texts literary, social, articles on the Mediterranean. Psychomotor: 1. To work together and collect information for the Mediterranean Sea. 2. Experiential approach to the natural environment. 3. Develop critical thinking. 4. Undertake responsibilities for the presentation of the program. Emotional: 1. To feel joy from participation in the program. 2. Being sensitized and configure attitudes and actions of respect towards the environment. Methodology implementation: Teamwork. Interdisciplinary - holistic to dissemination of program recordings to courses curriculum. Study in the field. Gathering information from newspapers, magazines, internet, maps, and photographs. Experiential method- Project. Assessment methods and self-assessment. Fields of courses: Greek language- History- Biology- Chemistry- Technology Dissemination of results: Make a page of social media (facebook), a blog, enhancing environmental awareness via video, make an electronic poster.

  16. Mapping the late Quaternary evolution of the lower Mississippi Valley

    Science.gov (United States)

    Haugerud, R. A.; Simon, K. M.; James, T. S.

    2013-12-01

    The lower Mississippi Valley (LMV) extends from Cape Girardeau to Natchez and from Little Rock to Memphis. Extensive Quaternary terraces within the LMV have been considered to reflect downstream changes in base level (global sea level) and (or) upstream changes in water and sediment input because of glaciation. We suggest that the first-order control on terrace development was glacial-isostatic adjustment (GIA). Observed variation in heights of Quaternary alluvial surfaces at Memphis is 50 m (Rittenour et al., 2007). GIA modeling by Clark et al. (1994) predicted vertical displacement of as much as 130 m at Memphis over the last 18,000 years. ICE-5G models predict smaller displacement and reinforce the viability of GIA as the primary cause of LMV aggradation and incision. Existing analyses of LMV terraces are built on geomorphic maps by Saucier and colleagues (1974, 1994; Autin et al., 1991) that were interpreted from aerial photographs and inch-to-the-mile contour maps. Geomorphic mapping from high-resolution DEMs is more accurate, more rapid, and more reproducible than mapping from aerial photography and intermediate-resolution contours. Working from lidar DEMs (1-5 m XY resolution) and the 10 m National Elevation Dataset (NED) DEM largely derived from 1:24,000 scale contours, Haugerud is mapping the geomorphology of the LMV at ~1:500,000 scale. Goals are to explore the GIA-terrace hypothesis and improve the geomorphic and stratigraphic context for studies of New Madrid seismicity. Mapping leads to several observations: 1. The Holocene floodplain of the Mississippi River onlaps older surfaces. The river appears to be filling a hole created by collapse of the Laurentide forebulge. Continued filling of this accommodation space will, barring human intervention, enable the river to abandon its course through Thebes Gap in favor of a lower-elevation route through Oran Gap. 2. Within Holocene meander belts, younger levee crests are higher than older levee crests. The

  17. A didactical geological path in Val Rosandra valley (Trieste - Italy)

    Science.gov (United States)

    Godini, E.

    2012-04-01

    Introduction: the presented field work is aimed to involve a group of 15-17 years old students in building a simplified geomorphological and geological model of Val Rosandra valley, by means of guided observations and data collection. The didactical path may be changed according to age, skills or particular needs of students and meteorological conditions; at best, 4-5 hours are needed for the complete field trip. Some ideas about sedimentary rocks, folding and faulting, and the principle of superposition could be useful as pre-concepts, but "could" also be learnt during the experience. Organization: students will be divided into small groups (3-4 students each), possibly with different roles within the group (topographer, photographer, draftsman, geologist, geomorphologist,…). Needed materials for each group: notebook, paper, pencil, rubber, photo camera, ruler, compass, scale 10.000 topographic map, stratigraphic chart, altimeter, diluted hydrochloric acid. Observation points: 1. Bagnoli spring, marl outcrop 2. Bagnoli village, towards the "heart-shaped quarry" 3. By the river, in the lower part of the valley 4. Moccò lookout 5. Marl outcrop, from Moccò to the old railway 6. From the old railway, above the valley 7. By the river, in the upper part of the valley The field work: at first, students will be guided to observe and take notes of the main morphological characteristics, so that the different "observation points" will be drawn on the map, with the help of compass. An easily recognizable system of faults cuts the valley; a "V" profile is visible in the lower part of the valley (a small amount of sediment is present), while a calcareous gorge is evident in the upper valley, where there are no sediments (observation points 3, 4, 6 and 7). The morphology is asymmetric, due to the different arrangement of strata in the left and right side of the valley: right side shows big "steps" (horizontal arrangement of strata), left side is rich in slopes (tilted

  18. Seasonal change of steric sea level in the GIN seas

    Science.gov (United States)

    Li, Lei; Wang, Huijuan; Sun, Ruili

    2011-03-01

    The Greenland Sea, Iceland Sea, and Norwegian Sea (GIN seas) form the main channel connecting the Arctic Ocean with other Oceans, where significant water and energy exchange take place, and play an important role in global climate change. In this study steric sea level, associated with temperature and salinity, in the GIN seas is examined based on analysis of the monthly temperature and salinity fields from Polar science center Hydrographic Climatology (PHC3.0). A method proposed by Tabata et al. is used to calculate steric sea level, in which, steric sea level change due to thermal expansion and haline contraction is termed as the thermosteric component (TC) and the halosteric component (SC), recpectively. Total steric sea level (TSSL) change is the sum of TC and SC. The study shows that SC is making more contributions than TC to the seasonal change of TSSL in the Greenland Sea, whereas TC contributes more in the Norwegian and the Iceland Seas. Annual variation of TSSL is larger than 50 mm over most regions of the GIN Seas, and can be larger than 200 mm at some locations such as 308 mm at 76.5°N, 12.5°E and 246 mm at 77.5°N, 17.5°W.

  19. Phosphorus dynamics in the Black Sea and Baltic Sea

    NARCIS (Netherlands)

    Dijkstra, N.

    2017-01-01

    The dynamics of the key nutrient phosphorus (P) in hypoxic and anoxic marine basins are still incompletely understood. This thesis focuses on the cycling of P in two of such basins: the Baltic Sea and the Black Sea. Water column particulates and sediments from the deep basin of the Black Sea were

  20. 76 FR 31009 - BNSF Railway Company-Trackage Rights Exemption-Yellowstone Valley Railroad, Inc.

    Science.gov (United States)

    2011-05-27

    ... Surface Transportation Board BNSF Railway Company--Trackage Rights Exemption--Yellowstone Valley Railroad, Inc. Yellowstone Valley Railroad, Inc. (YVRR) has agreed to grant, pursuant to a prospective written..., Yellowstone Valley Railroad, Inc.--Discontinuance Exemption--in Richland and Dawson Counties, Montana, in...

  1. 78 FR 34127 - Notice of Inventory Completion: Coachella Valley History Museum, Indio, CA

    Science.gov (United States)

    2013-06-06

    ... National Park Service Notice of Inventory Completion: Coachella Valley History Museum, Indio, CA AGENCY: National Park Service, Interior. ACTION: Notice. SUMMARY: The Coachella Valley History Museum has completed... funerary objects should submit a written request to the Coachella Valley History Museum. If no additional...

  2. 76 FR 38572 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

    Science.gov (United States)

    2011-07-01

    ... taking direct final action to approve revisions to the Antelope Valley Air Quality Management District... Valley Air Quality Management District (AVAQMD) and submitted by the California Air Resources Board (CARB... AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, Antelope Valley Air Quality...

  3. 78 FR 59840 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

    Science.gov (United States)

    2013-09-30

    ... of plan. * * * * * (c) * * * (428) * * * (i) * * * (B) Antelope Valley Air Quality Management...) * * * (i) * * * (B) Antelope Valley Air Quality Management District. (1) Rule 431.1, ``Sulfur Content of... AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, Antelope Valley Air Quality...

  4. 78 FR 45114 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

    Science.gov (United States)

    2013-07-26

    ... proposing to approve revisions to the Antelope Valley Air Quality Management District (AVAQMD) portion of... Rule 431.1 was actually for the South Coast Air Quality Management District (SCAQMD). The Antelope... Antelope Valley amended or rescinded the rule. On January 1, 2002, Antelope Valley Air Quality Management...

  5. 75 FR 17756 - Blackstone River Valley National Heritage Corridor Commission: Notice of Meeting

    Science.gov (United States)

    2010-04-07

    ... Office of the Secretary Blackstone River Valley National Heritage Corridor Commission: Notice of Meeting... the John H. Chafee Blackstone River Valley National Heritage Corridor Commission will be held on..., Executive Director, John H. Chafee, Blackstone River Valley National Heritage Corridor Commission, One Depot...

  6. 75 FR 64741 - Blackstone River Valley National Heritage Corridor Commission: Notice of Meeting

    Science.gov (United States)

    2010-10-20

    ... Office of the Secretary Blackstone River Valley National Heritage Corridor Commission: Notice of Meeting... the John H. Chafee Blackstone River Valley National Heritage Corridor Commission will be held on... the meeting to: Jan H. Reitsma, Executive Director, John H. Chafee, Blackstone River Valley National...

  7. 75 FR 2885 - Blackstone River Valley National Heritage Corridor Commission: Notice of Meeting

    Science.gov (United States)

    2010-01-19

    ... Office of the Secretary Blackstone River Valley National Heritage Corridor Commission: Notice of Meeting... the John H. Chafee Blackstone River Valley National Heritage Corridor Commission will be held on...: Jan H. Reitsma, Executive Director, John H. Chafee Blackstone River Valley National Heritage Corridor...

  8. 77 FR 2496 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

    Science.gov (United States)

    2012-01-18

    ... Valley Air Quality Management District (AVAQMD) and Imperial County Air Pollution Control District... AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management District and Imperial Valley Air Pollution Control District AGENCY: Environmental Protection...

  9. 77 FR 2469 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

    Science.gov (United States)

    2012-01-18

    ... to the Antelope Valley Air Quality Management District (AVAQMD) and Imperial County Air Pollution.... * * * * * (G) Antelope Valley Air Quality Management District. (1) Rule 1134, ``Stationary Gas Turbines... AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, Antelope Valley Air Quality...

  10. SEA LEVEL (TOPEX/POSEIDON)

    Data.gov (United States)

    National Aeronautics and Space Administration — Sea level rise is caused by the thermal expansion of sea water due to climate warming and widespread melting of land ice. The TOPEX/POSEIDON mission a joint...

  11. Atlantic Flyway Sea Duck Survey

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Atlantic Flyway Sea Duck Survey, conducted from 1991 to 2002 by the U.S. Fish and Wildlife Service, was established to record sea duck numbers using near shore...

  12. Is sea-level rising?

    Digital Repository Service at National Institute of Oceanography (India)

    Unnikrishnan, A.S.

    There has been considerable research on sea-level-rise caused by global warming. The various reports of the Intergovernmental Panel on Climate Change (IPCC) made assessments of observed sea level rise and future projections. Figure 1 shows a global...

  13. The Aggradational Successions of the Aniene River Valley in Rome: Age Constraints to Early Neanderthal Presence in Europe.

    Directory of Open Access Journals (Sweden)

    Fabrizio Marra

    Full Text Available We revise the chronostratigraphy of several sedimentary successions cropping out along a 5 km-long tract of the Aniene River Valley in Rome (Italy, which yielded six hominin remains previously attributed to proto- or archaic Neanderthal individuals, as well as a large number of lithic artefacts showing intermediate characteristics somewhere between the local Acheulean and Mousterian cultures. Through a method of correlation of aggradational successions with post-glacial sea-level rises, relying on a large set of published 40Ar/39Ar ages of interbedded volcanic deposits, we demonstrate that deposition of the sediments hosting the human remains spans the interval 295-220 ka. This is consistent with other well constrained ages for lithic industries recovered in England, displaying transitional features from Lower to Middle Paleolithic, suggesting the appearance of Mode 3 during the MIS 9-MIS 8 transition. Moreover, the six human bone fragments recovered in the Aniene Valley should be regarded as the most precisely dated and oldest hominin remains ascribable to Neanderthal-type individuals in Europe, discovered to date. The chronostratigraphic study presented here constitutes the groundwork for addressing re-analysis of these remains and of their associated lithic industries, in the light of their well-constrained chronological picture.

  14. The Aggradational Successions of the Aniene River Valley in Rome: Age Constraints to Early Neanderthal Presence in Europe.

    Science.gov (United States)

    Marra, Fabrizio; Ceruleo, Piero; Pandolfi, Luca; Petronio, Carmelo; Rolfo, Mario F; Salari, Leonardo

    2017-01-01

    We revise the chronostratigraphy of several sedimentary successions cropping out along a 5 km-long tract of the Aniene River Valley in Rome (Italy), which yielded six hominin remains previously attributed to proto- or archaic Neanderthal individuals, as well as a large number of lithic artefacts showing intermediate characteristics somewhere between the local Acheulean and Mousterian cultures. Through a method of correlation of aggradational successions with post-glacial sea-level rises, relying on a large set of published 40Ar/39Ar ages of interbedded volcanic deposits, we demonstrate that deposition of the sediments hosting the human remains spans the interval 295-220 ka. This is consistent with other well constrained ages for lithic industries recovered in England, displaying transitional features from Lower to Middle Paleolithic, suggesting the appearance of Mode 3 during the MIS 9-MIS 8 transition. Moreover, the six human bone fragments recovered in the Aniene Valley should be regarded as the most precisely dated and oldest hominin remains ascribable to Neanderthal-type individuals in Europe, discovered to date. The chronostratigraphic study presented here constitutes the groundwork for addressing re-analysis of these remains and of their associated lithic industries, in the light of their well-constrained chronological picture.

  15. The Aggradational Successions of the Aniene River Valley in Rome: Age Constraints to Early Neanderthal Presence in Europe

    Science.gov (United States)

    Ceruleo, Piero; Pandolfi, Luca; Petronio, Carmelo; Rolfo, Mario F.; Salari, Leonardo

    2017-01-01

    We revise the chronostratigraphy of several sedimentary successions cropping out along a 5 km-long tract of the Aniene River Valley in Rome (Italy), which yielded six hominin remains previously attributed to proto- or archaic Neanderthal individuals, as well as a large number of lithic artefacts showing intermediate characteristics somewhere between the local Acheulean and Mousterian cultures. Through a method of correlation of aggradational successions with post-glacial sea-level rises, relying on a large set of published 40Ar/39Ar ages of interbedded volcanic deposits, we demonstrate that deposition of the sediments hosting the human remains spans the interval 295–220 ka. This is consistent with other well constrained ages for lithic industries recovered in England, displaying transitional features from Lower to Middle Paleolithic, suggesting the appearance of Mode 3 during the MIS 9-MIS 8 transition. Moreover, the six human bone fragments recovered in the Aniene Valley should be regarded as the most precisely dated and oldest hominin remains ascribable to Neanderthal-type individuals in Europe, discovered to date. The chronostratigraphic study presented here constitutes the groundwork for addressing re-analysis of these remains and of their associated lithic industries, in the light of their well-constrained chronological picture. PMID:28125602

  16. CRYOGENESIS AND GEODYNAMICS OF ICING VALLEYS

    Directory of Open Access Journals (Sweden)

    V. R. Alekseyev

    2015-09-01

    Full Text Available Due to local groundwater seeping and freezing in layers that accumulate over each other and create large ice clusters on the ground surface, specific conditions of energy and mass transfer are created in the atmosphere–soil–lithosphere system. In winter, the vertical temperature distribution curve is significantly deformed due to heat emission from the water layer above the ice cover during its freezing, and a thermocline is thus formed. Deformation of the temperature curve is gradually decreasing in size downward the profile and decays at the interface of frozen and thaw rocks. Values and numbers of temperature deviations from a 'normal' value depend on heat reserves of aufeis water and the number of water seeps/discharges at a given location. The production of the thermocline alters freezing conditions for underlying ground layers and changes the mechanism of ice saturation, thus leading to formation of two-layer ice-ground complexes (IGC. IGCs are drastically different from cryogenic formations in the neighbouring sections of the river valley. Based on genetic characteristics and the ratios of components in the surface and subsurface layers, seven types of aufeis IGCs are distinguished: massive-segregation, cement-basal, layered-segregation, basal-segregation, vacuum-filtration, pressure-injection, and fissure-vein. Annual processes of surface and subsurface icing and ice ablation are accompanied by highly hazardous geodynamic phenomena, such as winter flooding, layered water freezing, soil heaving/pingo, thermokarst and thermal erosion. Combined, these processes lead to rapid and often incidental reconfigurations of the surface and subsurface runoff channels, abrupt uplifting and subsiding of the ground surface, decompaction and 'shaking-up' of seasonally freezing/thawing rocks, thereby producing exceptionally unfavourable conditions for construction and operation of engineering structures.Formation and development of river networks are

  17. CRYOGENESIS AND GEODYNAMICS OF ICING VALLEYS

    Directory of Open Access Journals (Sweden)

    V. R. Alekseyev

    2015-01-01

    Full Text Available Due to local groundwater seeping and freezing in layers that accumulate over each other and create large ice clusters on the ground surface, specific conditions of energy and mass transfer are created in the atmosphere–soil–lithosphere system. In winter, the vertical temperature distribution curve is significantly deformed due to heat emission from the water layer above the ice cover during its freezing, and a thermocline is thus formed. Deformation of the temperature curve is gradually decreasing in size downward the profile and decays at the interface of frozen and thaw rocks. Values and numbers of temperature deviations from a 'normal' value depend on heat reserves of aufeis water and the number of water seeps/discharges at a given location. The production of the thermocline alters freezing conditions for underlying ground layers and changes the mechanism of ice saturation, thus leading to formation of two-layer ice-ground complexes (IGC. IGCs are drastically different from cryogenic formations in the neighbouring sections of the river valley. Based on genetic characteristics and the ratios of components in the surface and subsurface layers, seven types of aufeis IGCs are distinguished: massive-segregation, cement-basal, layered-segregation, basal-segregation, vacuum-filtration, pressure-injection, and fissure-vein. Annual processes of surface and subsurface icing and ice ablation are accompanied by highly hazardous geodynamic phenomena, such as winter flooding, layered water freezing, soil heaving/pingo, thermokarst and thermal erosion. Combined, these processes lead to rapid and often incidental reconfigurations of the surface and subsurface runoff channels, abrupt uplifting and subsiding of the ground surface, decompaction and 'shaking-up' of seasonally freezing/thawing rocks, thereby producing exceptionally unfavourable conditions for construction and operation of engineering structures.Formation and development of river networks are

  18. Subsurface and petroleum geology of the southwestern Santa Clara Valley ("Silicon Valley"), California

    Science.gov (United States)

    Stanley, Richard G.; Jachens, Robert C.; Lillis, Paul G.; McLaughlin, Robert J.; Kvenvolden, Keith A.; Hostettler, Frances D.; McDougall, Kristin A.; Magoon, Leslie B.

    2002-01-01

    Gravity anomalies, historical records of exploratory oil wells and oil seeps, new organic-geochemical results, and new stratigraphic and structural data indicate the presence of a concealed, oil-bearing sedimentary basin beneath a highly urbanized part of the Santa Clara Valley, Calif. A conspicuous isostatic-gravity low that extends about 35 km from Palo Alto southeastward to near Los Gatos reflects an asymmetric, northwest-trending sedimentary basin comprising low-density strata, principally of Miocene age, that rest on higher-density rocks of Mesozoic and Paleogene(?) age. Both gravity and well data show that the low-density rocks thin gradually to the northeast over a distance of about 10 km. The thickest (approx 4 km thick) accumulation of low-density material occurs along the basin's steep southwestern margin, which may be controlled by buried, northeast-dipping normal faults that were active during the Miocene. Movement along these hypothetical normal faults may been contemporaneous (approx 17–14 Ma) with sedimentation and local dacitic and basaltic volcanism, possibly in response to crustal extension related to passage of the northwestward-migrating Mendocino triple junction. During the Pliocene and Quaternary, the normal faults and Miocene strata were overridden by Mesozoic rocks, including the Franciscan Complex, along northeastward-vergent reverse and thrust faults of the Berrocal, Shannon, and Monte Vista Fault zones. Movement along these fault zones was accompanied by folding and tilting of strata as young as Quaternary and by uplift of the modern Santa Cruz Mountains; the fault zones remain seismically active. We attribute the Pliocene and Quaternary reverse and thrust faulting, folding, and uplift to compression caused by local San Andreas Fault tectonics and regional transpression along the Pacific-North American Plate boundary. Near the southwestern margin of the Santa Clara Valley, as many as 20 exploratory oil wells were drilled between 1891

  19. Pediatric Burns at The Rift Valley Provincial General Hospital ...

    African Journals Online (AJOL)

    Aim To determine the etiology and outcome of pediatric burns (0-12 years). Design A retrospective study of burn victims hospitalized at the Rift Valley Provincial General Hospital, Nakuru, Kenya from April 2004 to March 2007. Method Charts of all children hospitalized for burn injury were reviewed for patient demographics, ...

  20. Pediatric Burns at The Rift Valley Provincial General Hospital ...

    African Journals Online (AJOL)

    surgical/female burn ward were eligible. On average the ward admits 680 patients a year out of which 170 pa- tients (25.7 %) are due to pediatric burns. The Hospital attracts patients mostly from low socioeconomic status. Pediatric Burns at The Rift Valley. Provincial General Hospital, Nakuru,. Kenya. Author: Oduor P.R. ...

  1. Rio Grande Valley State Park maintenance, improvements, and developments

    Science.gov (United States)

    Tony Barron

    1996-01-01

    Managing the Rio Grande Valley State Park as a valued riparian-wetland area is very important as it encourages conditions for the growth of vegetation. This growth supports a riparian community consisting of various insects, animals, birds, and fish, as well as other wildlife. Human activity in riparian areas has led to historic use patterns causing erosion, re-...

  2. A DECADE FROM THE MAJOR LAYOFFS IN THE JIU VALLEY

    Directory of Open Access Journals (Sweden)

    IOAN VALENTIN FULGER

    2011-01-01

    Full Text Available This essay is an overview of how the population of the largest coalfield of Romania Jiu Valley, the perceived major staff cuts in the mining industry, the solutions required for economic rehabilitation of the area and difficulties of everyday faced by residents of the region.

  3. Feasibility of target communities in a Dutch brook valley system

    NARCIS (Netherlands)

    Prins, AH; Bekker, RM

    As a reaction to the ongoing deterioration of nature conservation interest in The Netherlands, an offensive nature strategy was formulated in the 1990 Nature Policy Plan. In this Plan, target communities and target plant species are mentioned. For the 'Drentse A brook valley system', target

  4. Opening remarks for the Fort Valley Centennial Celebration

    Science.gov (United States)

    G. Sam Foster

    2008-01-01

    The Rocky Mountain Research Station recognizes and values the contributions of our scientists and collaborators for their work over the past century at Fort Valley Experimental Forest. With the help of our partners and collaborators, Rocky Mountain Research Station is working to improve coordination across its research Program Areas and Experimental Forests and Ranges...

  5. Opening remarks for the Fort Valley Centennial Celebration (P-53)

    Science.gov (United States)

    G. Sam Foster

    2008-01-01

    The Rocky Mountain Research Station recognizes and values the contributions of our scientists and collaborators for their work over the past century at Fort Valley Experimental Forest. With the help of our partners and collaborators, Rocky Mountain Research Station is working to improve coordination across its research Program Areas and Experimental Forests and Ranges...

  6. Valley segments, stream reaches, and channel units [Chapter 2

    Science.gov (United States)

    Peter A. Bisson; David R. Montgomery; John M. Buffington

    2006-01-01

    Valley segments, stream reaches, and channel units are three hierarchically nested subdivisions of the drainage network (Frissell et al. 1986), falling in size between landscapes and watersheds (see Chapter 1) and individual point measurements made along the stream network (Table 2.1; also see Chapters 3 and 4). These three subdivisions compose the habitat for large,...

  7. Parking Space Occupancy at Rail Stations in Klang Valley

    Directory of Open Access Journals (Sweden)

    Ho Phooi Wai

    2017-01-01

    Full Text Available The development of Klang Valley Integrated Rapid Transit system in Klang Valley, Malaysia has been quickly gaining momentum during the recent years. There will be two new MRT lines (MRT Line 1 and MRT Line 2 and one new LRT line (LRT Line 3 extended from the current integrated rail transit system by year 2020 with more than 90 new rail stations. With the substantial addition of potential rail passengers, there are doubts whether the existing Park and Ride facilities in Klang Valley are able to accommodate the future parking space demand at rail stations. This research studies the parking occupancy at various Park and Ride facilities in Klang Valley namely Taman Jaya, Asia Jaya, Taman Paramount, Taman Bahagia and Kelana Jaya by applying the non-conventional method utilizing Google Earth imageries. Results showed that the parking occupancy rate at these LRT stations were 100% or more before the commencement of LRT extension (Kelana Jaya and Ampang Lines in 2016 and in the range of 36% to 100% after the commencement of LRT extension due to the additionally built car parks and changes in parking pattern with dispersed passenger traffic.

  8. Comparison of access to medicines between Klang Valley and East ...

    African Journals Online (AJOL)

    Pharmacotherapy Group, Faculty of Pharmacy, University of Benin, Benin City, 300001 Nigeria. All rights reserved. ... available [5], suggesting that problems may exist ... access to medicines for children living in poor households in the economically contrasting areas of Klang Valley and East Coast of Peninsular. Malaysia.

  9. Forest pathology and entomology at Fort Valley Experimental Forest

    Science.gov (United States)

    Brian W. Geils

    2008-01-01

    Forest pathology and entomology have been researched at Fort Valley Experimental Forest throughout its history. The pathogens and insects of particular interest are mistletoes, decay and canker fungi, rusts, bark beetles, and various defoliators. Studies on life history, biotic interactions, impacts, and control have been published and incorporated into silvicultural...

  10. HBO-I on tour in Silicon Valley

    NARCIS (Netherlands)

    Ir. Deny Smeets; Drs. Miranda W Valkenburg

    2005-01-01

    Wat is 'hot' en wat is 'not' in de ict? Dat was 'in a nutshell' de reden voor het HBO-I om een studiereis te maken naar het Mekka voor ict'ers: Silicon Valley. Voor VS-verhoudingen een klein gebied met relatief veel belangrijke ict-bedrijven: SUN, Intel, Oracle, Hewlett-Packard. En twee van de beste

  11. A case study: Death Valley National Monument California-Nevada

    Science.gov (United States)

    Daniel Hamson; Ristau Toni

    1979-01-01

    With passage of the Mining in the Parks Act (P.L. 94-429) in 1976, the National Park Service, Department of the Interior, was given the responsibility of preparing a report to Congress outlining the environmental consequences of mining on claims within Death Valley National Monument. In addition, the Secretary of the Interior is required to formulate a recommendation...

  12. Birds of Rishi Valley, and Renewal of their Habitats

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 5; Issue 1. Birds of Rishi Valley, and Renewal of their Habitats. Mahesh Rangarajan. Book Review Volume 5 Issue 1 January 2000 pp 105-106 ... Author Affiliations. Mahesh Rangarajan1. Nehru Memorial Museum and Library, New Delhi, India.

  13. Fluoride Contamination in Drinking Water in the Rift Valley, Kenya ...

    African Journals Online (AJOL)

    A survey of the amount of Fluoride in ground, potable water in Njoro division, Nakuru district and some parts outside the division was conducted to determine the concentration of Fluoride the residents are consuming through water. This area is situated in the Great Rift Valley of East Africa, which is known to have high levels ...

  14. Pathways to High-tech Valleys and Research Triangles

    NARCIS (Netherlands)

    Hulsink, W.; Dons, H.

    2008-01-01

    Silicon Valley and the industrial districts of Italy, where shared identity, superior skills, regional specialization and trust-based networking among local firms have produced dynamic and flexible ecosystems, are inspiring examples of the successful promotion of thriving technology and business

  15. Birds of Rishi Valley, and Renewal of their Habitats

    Indian Academy of Sciences (India)

    Nehru Memorial Museum Library. New Delhi, 1993, pp. 235. At a time when environmental concerns are commonly identified with lost causes and battles fought against heavy odds, it is a delight to come across a story of hope. Rishi. Valley's is a tale of ecological renewal in more ways than one. Rayalaseema, in Andhra.

  16. A Student Government Guidebook for Evergreen Valley College.

    Science.gov (United States)

    Chavez, Mauro

    Designed to help develop informed and capable student leadership in student affairs at Evergreen Valley College (EVC), this student government guide and text for Government 91 focuses on the major leadership needs and objectives of student government within a participatory framework. After an explanation of course objectives and requirements,…

  17. An Instructional Guide for Ethnic Studies at Evergreen Valley College.

    Science.gov (United States)

    Chavez, Mauro

    Guidelines and conceptual parameters are presented for ethnic studies courses at Evergreen Valley College (EVC). Introductory material discusses the requirement that all associate degree students complete three units of ethnic studies; presents general guidelines for ethnic studies; defines "ethnic-racial minority"; and suggests criteria for…

  18. Fort Valley studies: A natural laboratory for research and education

    Science.gov (United States)

    Brian W. Geils

    2008-01-01

    Drought, wildfire, extinction, and invasive species are considered serious threats to the health of our forests. Although these issues have global connections, we most readily see their consequences locally and attempt to respond with management based on science. For 100 years, the Fort Valley Experimental Forest (FVEF) has provided educational and experimental support...

  19. Hydropluviometric variability in the low valley of the mono | Vissin ...

    African Journals Online (AJOL)

    The results show the dependence of flow and recharge from rainfall fluctuations. Keywords: Low Valley of Mono, hydropluviometric variability, impact, hydropluviometric deficits. Resume Cette recherche est consacrée à l'analyse de l'impact de la variabilité pluviométrique sur le cycle hydrologique et les ressources en eau.

  20. Appendix C: The sources of Copan Valley obsidian

    Energy Technology Data Exchange (ETDEWEB)

    Harbottle, G. [Brookhaven National Lab., Upton, NY (United States); Neff, H.; Bishop, R.L. [Smithsonian Institution, Washington, DC (United States). Conservation Analytical Lab.

    1995-05-01

    One hundred thirty-nine obsidian samples from the Copan Valley were subjected to neutron activation analysis at Brookhaven National Laboratory (BNL). Obsidian sources from Mesoamerica have been characterized by a number of different laboratories using several techniques. Over 1,800 samples from Mesoamerica have been analyzed by neutron activation at BNL. These data are now housed both at BNL and in the Smithsonian Archaeometric Research Collections and Records (SARCAR) data base. Previous statistical analysis of the Mesoamerican obsidian artifacts and source samples has produced reference groups representing many of the sources, including Ixtepeque, San Martin Jilotepeque, and El Chayal, the three sources closest to the Copan Valley and therefore most likely to be represented in the analyzed sample. As anticipated, the overwhelming majority of obsidian recovered in the Copan Valley comes from the closest source, Ixtepeque. Of the seven El Chayal specimens, four pertain to CV-43 and three pertain to CV-20. These data provide no evidence of a difference between the two localities in external obsidian exchange relations. Thus, the authors find no grounds for questioning the assumption that the minor quantities of El Chayal obsidian that reached the Copan Valley were distributed through the same channels responsible for distribution of the more common Ixtepeque obsidian.

  1. Blue and Valley Oak Seedling Establishment on California's Hardwood Rangelands

    Science.gov (United States)

    Theodore E. Adams Jr.; Peter B. Sands; William H. Weitkamp; Neil K. McDougald

    1991-01-01

    Factors contributing to poor establishment of blue oak (Quercus douglasii) and valley oak (Q. lobata) in California oak-grassland savannas were studied in a series of acorn seeding experiments initiated in 1985. Exclusion of large herbivores permitted examination of herbaceous interference and small mammal and insect depredation....

  2. Integrated management of water resources in the valley of Oued ...

    African Journals Online (AJOL)

    This study designed to analyze and evaluate the results of trend scenarios of the strategy management of water resources used in the valley of Oued-Souf, who led the region to a truly dramatic situation and almost desperate: rise of groundwater and its adverse consequences. In terms of this work, we seek a model (plan) ...

  3. Analysis of the Malaria situation in Hippo Valley Estates | Chirebvu ...

    African Journals Online (AJOL)

    ... not infected with sporozoites. The malaria control programme for Hippo Valley Estates appears to be effective in controlling malaria disease. However, some other factors could be contributing to the low malaria transmission pattern observed in the estates. The Zimbabwe Science News Volume 34(2) June 2000, pp. 34-37 ...

  4. Leishmaniases survey in the Awash Valley: The magnitude of ...

    African Journals Online (AJOL)

    Background: Both visceral and cutaneous leishmaniasis are reckoned to be endemic in Ethiopia in magnitudes of undetermined prevalence and distribution. There is considerable information pertaining to the public health importance of leishmaniases in the lower course of the Rift Valley of Ethiopia. Nevertheless, there is ...

  5. Herpetology of the American Madrean Archipelago and adjacent valleys

    Science.gov (United States)

    Lawrence L. C. Jones

    2005-01-01

    Approximately 110 species of amphibians (18 frogs and toads, and 1 salamander) and reptiles (47 snakes, 39 lizards, and 5 turtles) are known from the American Madrean Archipelago and adjacent valleys. The high diversity of the herpetofauna comes from a variety of factors, including a convergence of biotic communities representing deserts, grasslands, and mountains....

  6. Forecast and Outbreak of Rift valley fever in Sudan, 2007

    Science.gov (United States)

    Background Rift Valley fever (RVF) outbreaks occur during heavy rainfall in various sub-Saharan countries including Kenya, Somalia, and Tanzania and more recently in Saudi Arabia and Yemen. Given the wide geographic and ecological range of RVF virus, it is necessary to monitor large areas for condit...

  7. Rift Valley fever Entomology, Ecology, and Outbreak Risk Factors

    Science.gov (United States)

    Rift Valley fever (RVF) is a mosquito-borne zoonotic disease of domestic ruminants and humans in Africa. The disease is most severe in cattle, sheep, and goats, and it causes high mortality in young animals and abortion in adults. Exotic aanimal breeds from areas where RVF is not endemic tend to be ...

  8. Sound propagation from a ridge wind turbine across a valley

    Science.gov (United States)

    Van Renterghem, Timothy

    2017-04-01

    Sound propagation outdoors can be strongly affected by ground topography. The existence of hills and valleys between a source and receiver can lead to the shielding or focusing of sound waves. Such effects can result in significant variations in received sound levels. In addition, wind speed and air temperature gradients in the atmospheric boundary layer also play an important role. All of the foregoing factors can become especially important for the case of wind turbines located on a ridge overlooking a valley. Ridges are often selected for wind turbines in order to increase their energy capture potential through the wind speed-up effects often experienced in such locations. In this paper, a hybrid calculation method is presented to model such a case, relying on an analytical solution for sound diffraction around an impedance cylinder and the conformal mapping (CM) Green's function parabolic equation (GFPE) technique. The various aspects of the model have been successfully validated against alternative prediction methods. Example calculations with this hybrid analytical-CM-GFPE model show the complex sound pressure level distribution across the valley and the effect of valley ground type. The proposed method has the potential to include the effect of refraction through the inclusion of complex wind and temperature fields, although this aspect has been highly simplified in the current simulations. This article is part of the themed issue 'Wind energy in complex terrains'.

  9. Status and population of vultures in Moyar Valley, southern India

    Directory of Open Access Journals (Sweden)

    R. Venkitachalam

    2016-01-01

    Full Text Available Four species of vultures were surveyed using road transects in two parts of the Moyar Valley, three of these are Critically Endangered by IUCN criteria and one is Endangered.  The vulture study was done for the first time in Nilgiri North Forest Division and Sathyamangalam Tiger Reserve of Moyar Valley to determine the flock size in the three species of vultures and also to get a rough estimation of vultures. The results show higher flock size and higher densities in Nilgiri North Forest Division than in Sathyamangalam Tiger Reserve and the most numerous of these was the White-rumped Vulture.  There is also evidence of seasonal movements in Nilgiri North Forest Division.  These data represent the first systematic survey results from the area and demonstrate the significance of the Moyar Valley for all four Endangered vulture species, probably the main stronghold remaining in southern India.  They are White-rumped Vulture Gyps bengalensis, Indian Vulture Gyps indicus, Red-headed Vulture Sarcogyps calvus and Egyptian Vulture Neophron percnopterus.  The study recommends that immediate long-term conservation efforts should be taken to save the Critically Endangered vultures in the Moyar Valley

  10. Business plan Seed potato programmes Zambezi Valley, Mozambique

    NARCIS (Netherlands)

    Haverkort, F.; Saavedra Gonzalez, Y.R.

    2015-01-01

    This business plan has been prepared for local entrepreneurs who would like to expand/start their business portfolio and are looking for an opportunity of investment in the agricultural sector in the Zambezi Valley in Mozambique. We propose the creation of a seed potato programme for the red skinned

  11. Effective utilization of the valley bushveld | AJ | African Journal of ...

    African Journals Online (AJOL)

    The development of the arid Valley Bushveld to its full potential is discussed. Boer goats and Dorpers select forage of different quality within this veld type. In addition, Dorpers are chiefly grazers while Boer goats are browsers. The results show that more browsers can be maintained per unit area than grazers and that the ...

  12. Summertime wind climate in Yerevan: valley wind systems

    Science.gov (United States)

    Gevorgyan, Artur

    2017-03-01

    1992-2014 wind climatology analysis in Yerevan is presented with particular focus given to the summertime thermally induced valley wind systems. Persistence high winds are observed in Yerevan during July-August months when the study region is strongly affected by a heat-driven plain-plateau circulation. The local valley winds arrive in Yerevan in the evening hours, generally, from 1500 to 1800 UTC, leading to rapid enhancement of wind speeds and dramatic changes in wind direction. Valley-winds significantly impact the local climate of Yerevan, which is a densely populated city. These winds moderate evening temperatures after hot and dry weather conditions observed during summertime afternoons. On the other hand, valley winds result in significantly higher nocturnal temperatures and more frequent occurrence of warm nights (tn90p) in Yerevan due to stronger turbulent mixing of boundary layer preventing strong surface cooling and temperature drop in nighttime and morning hours. The applied WRF-ARW limited area model is able to simulate the key features of the observed spatial pattern of surface winds in Armenia associated with significant terrain channeling, wind curls, etc. By contrast, ECMWF EPS global model fails to capture mesoscale and local wind systems over Armenia. However, the results of statistical verification of surface winds in Yerevan showed that substantial biases are present in WRF 18-h wind forecasts, as well as, the temporal variability of observed surface winds is not reproduced adequately in WRF-ARW model.

  13. Factors limiting recruitment in valley and coast live oak

    Science.gov (United States)

    Claudia M. Tyler; Bruce E. Mahall; Frank W. Davis; Michael Hall

    2002-01-01

    The Santa Barbara County Oak Restoration Program was initiated in 1994 to determine the major factors limiting recruitment of valley oak (Quercus lobata) and coast live oak (Q. agrifolia). At Sedgwick Reserve in Santa Barbara County, California, we have replicated large-scale planting experiments in four different years to...

  14. Business plan Tilapia Pond Farming in the Zambezi Valley, Mozambique

    NARCIS (Netherlands)

    Brouwer, Herman; Meer, van der Magnus

    2015-01-01

    This business plan has been prepared for local entrepreneurs who would like to expand their business portfolio or to start a value chain business in the aquaculture sector in the Zambezi Valley, Mozambique.

    Freshwater aquaculture in Mozambique consists mainly of small-scale tilapia

  15. Range management research, Fort Valley Experimental Forest (P-53)

    Science.gov (United States)

    Henry A. Pearson; Warren P. Clary; Margaret M. Moore; Carolyn Hull Sieg

    2008-01-01

    Range management research at the Fort Valley Experimental Forest during the past 100 years has provided scientific knowledge for managing ponderosa pine forests and forest-range grazing lands in the Southwest. Three research timeperiods are identified: 1908 to 1950, 1950 to 1978, and 1978 to 2008. Early research (1908-1950) addressed ecological effects of livestock...

  16. pastoralist tribes in lower Omo Valley, Southwestern Ethiopia

    African Journals Online (AJOL)

    ACIPH_Admin

    Abstract. Background: Survey of intestinal parasites provides information about the burden of parasites in a community and helps in making decisions for intervention. Nevertheless, such information on the communities living in the Lower. Omo Valley is scanty. Objective: To study the prevalence of intestinal parasitosis ...

  17. Gravity Data from Newark Valley, White Pine County, Nevada

    Science.gov (United States)

    Mankinen, Edward A.; McKee, Edwin H.

    2007-01-01

    The Newark Valley area, eastern Nevada is one of thirteen major ground-water basins investigated by the BARCAS (Basin and Range Carbonate Aquifer Study) Project. Gravity data are being used to help characterize the geophysical framework of the region. Although gravity coverage was extensive over parts of the BARCAS study area, data were sparse for a number of the valleys, including the northern part of Newark Valley. We addressed this lack of data by establishing seventy new gravity stations in and around Newark Valley. All available gravity data were then evaluated to determine their reliability, prior to calculating an isostatic residual gravity map to be used for subsequent analyses. A gravity inversion method was used to calculate depths to pre-Cenozoic basement rock and estimates of maximum alluvial/volcanic fill. The enhanced gravity coverage and the incorporation of lithologic information from several deep oil and gas wells yields a view of subsurface shape of the basin and will provide information useful for the development of hydrogeologic models for the region.

  18. 36 CFR 7.17 - Cuyahoga Valley National Recreation Area.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Cuyahoga Valley National Recreation Area. 7.17 Section 7.17 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF... Recreation Area. (a) Alcoholic beverages—(1) Possession. The possession or consumption of a bottle, can, or...

  19. Martian channels and valleys - Their characteristics, distribution, and age

    Science.gov (United States)

    Carr, M. H.; Clow, G. D.

    1981-01-01

    The distribution and ages of Martian channels and valleys, which are generally believed to have been cut by running water, are examined with particular emphasis on the small branching networks referred to as runoff channels or valley networks. Valleys at latitudes from 65 deg S to 65 deg N were surveyed on Viking images at resolutions between 125 and 300 m. Almost all of the valleys are found in the old cratered terrain, in areas characterized by high elevations, low albedos and low violet/red ratios. The networks are deduced to have formed early in the history of the planet, with a formation rate declining rapidly shortly after the decline of the cratering rate 3.9 billion years ago. Two types of outflow channels are distinguished: unconfined, in which broad swaths of terrain are scoured, and confined, in which flow is restricted to discrete channels. Both types start at local sources, and have formed episodically throughout Martian history. Fretted channels, found mainly in two latitude belts characterized by relatively rapid erosion along escarpments, are explained by the lateral enlargement of other channels by mass wasting.

  20. Neotectonics of the Roer Valley Rift System, the Netherlands.

    NARCIS (Netherlands)

    Houtgast, R.F.; van Balen, R.T.

    2000-01-01

    The Roer Valley Rift System (RVRS) is located in the southern part of the Netherlands and adjacent parts of Germany and Belgium. The last rifting episode of the RVRS started in the Late Oligocene and is still ongoing. The present-day seismic activity in the rift system is part of that last rifting

  1. Early thinning experiments established by the Fort Valley Experimental Forest

    Science.gov (United States)

    Benjamin P. De Blois; Alex. J. Finkral; Andrew J. Sanchez Meador; Margaret M. Moore

    2008-01-01

    Between 1925 and 1936, the Fort Valley Experimental Forest (FVEF) scientists initiated a study to examine a series of forest thinning experiments in second growth ponderosa pine stands in Arizona and New Mexico. These early thinning plots furnished much of the early background for the development of methods used in forest management in the Southwest. The plots ranged...

  2. Fort Valley's early scientists: A legacy of distinction

    Science.gov (United States)

    Andrew J. Sanchez Meador; Susan D. Olberding

    2008-01-01

    When the Riordan brothers of Flagstaff, Arizona, asked Gifford Pinchot to determine why there was a deficit in ponderosa pine seedlings, neither party understood the historical significance of what they were setting in motion for the field of forest research. The direct result of that professional favor was the establishment of the Fort Valley Experiment Station (Fort...

  3. Fort Valley's early scientists: A legacy of distinction (P-53)

    Science.gov (United States)

    Andrew J. Sanchez Meador; Susan D. Olberding

    2008-01-01

    When the Riordan brothers of Flagstaff, Arizona asked Gifford Pinchot to determine why there was a deficit in ponderosa pine seedlings, neither party understood the historical significance of what they were setting in motion for the field of forest research. The direct result of that professional favor was the establishment of the Fort Valley Experiment Station (Fort...

  4. 1 characteristics, classification and management of inland valley ...

    African Journals Online (AJOL)

    OLUWOLE AKINNAGBE

    ABSTRACT. Inland valley bottoms (IVBs) on basement complex in sub-humid southwestern Nigeria were studied for water-table (WT) dynamics, and physical and chemical characteristics for their classification and management needs for crop production. The IVBs are generally small in size. About 64% of the.

  5. Impact of Global Climate on Rift Valley Fever Disease Outbreaks

    Science.gov (United States)

    Rift Valley fever is a viral disease of animals and humans in Africa and the Middle East that is transmitted by mosquitoes. Since the virus was first isolated in Kenya in 1930 it has caused significant impact to animal and human health and national economies, and it is of concern to the internationa...

  6. Sound propagation from a ridge wind turbine across a valley.

    Science.gov (United States)

    Van Renterghem, Timothy

    2017-04-13

    Sound propagation outdoors can be strongly affected by ground topography. The existence of hills and valleys between a source and receiver can lead to the shielding or focusing of sound waves. Such effects can result in significant variations in received sound levels. In addition, wind speed and air temperature gradients in the atmospheric boundary layer also play an important role. All of the foregoing factors can become especially important for the case of wind turbines located on a ridge overlooking a valley. Ridges are often selected for wind turbines in order to increase their energy capture potential through the wind speed-up effects often experienced in such locations. In this paper, a hybrid calculation method is presented to model such a case, relying on an analytical solution for sound diffraction around an impedance cylinder and the conformal mapping (CM) Green's function parabolic equation (GFPE) technique. The various aspects of the model have been successfully validated against alternative prediction methods. Example calculations with this hybrid analytical-CM-GFPE model show the complex sound pressure level distribution across the valley and the effect of valley ground type. The proposed method has the potential to include the effect of refraction through the inclusion of complex wind and temperature fields, although this aspect has been highly simplified in the current simulations.This article is part of the themed issue 'Wind energy in complex terrains'. © 2017 The Author(s).

  7. The Sweet Valley High Gang Goes to College.

    Science.gov (United States)

    Litton, Joyce A.

    1996-01-01

    Examines the first 14 books of the "Sweet Valley University" series. Finds that the storylines on sex send conflicting messages that make readers believe that premarital sex is not an important issue. Notes that date rape and a brief look at racism and alcohol abuse are the only serious topics addressed. (RS)

  8. Sailing New Seas

    Science.gov (United States)

    1998-03-01

    forum. The Navy needs a better forum fo r ideas . One can be built on the Internet . That job should be done now. Who among us will do it? The Navy...For coevolution to occur, diversity of ideas must be catalyzed by communication (diversity wi thout 86 Sail ing New Seas communicatio n among

  9. Sea Basing Logistiek

    Science.gov (United States)

    2007-11-01

    flexibiliteit, dynamiek en configureerbaarheid afhankelijk van de missie behoefte is wat hen aanspreekt: ’Joint Sea Base is a frame of mind, not a...en dat tijdens de sustain fase selectief gelost kan worden, is bet van belang orn voorafgaand aan de close fase stil te staan bij de manier waarop

  10. The European sea bass

    NARCIS (Netherlands)

    Cardoso, J.F.M.F.; Freitas, V.; Quilez, I.; Jouta, J.; Witte, J.IJ.; van der Veer, H.W.

    2015-01-01

    This paper analyses the population dynamics, growth and feeding ecology of Dicentrarchus labrax in order to gain a better understanding of its present role in the western Dutch Wadden Sea ecosystem. Otolith analysis showed that the population is mostly comprised of individuals aged 3–5 years old and

  11. Wadden Sea Mud

    DEFF Research Database (Denmark)

    Møller-Jensen, P.

    The present thesis deals with the transport phenomena of estuarine cohesive sediment from a laboratory and a numerical point of view. The cohesive sediment used throughout the whole process was natural mud from the Danish part of the Wadden sea, Ho Bay. In the laboratory, the work was concentrated...

  12. Solar Sea Power

    Science.gov (United States)

    Zener, Clarence

    1976-01-01

    In their preoccupation with highly complex new energy systems, scientists and statesmen may be overlooking the possibilities of Ocean Thermal Energy Conversion (OTEC). That is the view of a Carnegie-Mellon University physicist who is in the forefront of solar sea power investigation. (Author/BT)

  13. Camp Sea Lab Visit

    OpenAIRE

    2009-01-01

    Approved for public release; distribution is unlimited On Wednesday July 8th, CAVR hosted 32 eight to thirteen year olds from California State Monterey Bay’s summer Camp SEA Lab. The students had the opportunity to interact with robotic dogs, an autonomous underwater vehicle (AUV), remotely operated vehicle (ROV), and unmanned aerial vehicles (UAV).

  14. North Sea reefs

    NARCIS (Netherlands)

    Coolen, Joop Waltherus Petrus

    2017-01-01

    The objective of the research presented in this thesis was to understand the patterns of benthic biodiversity on reefs in the North Sea. To gain this understanding, I studied which species are present on natural and artificial reefs, what environmental and biotic variables influence the presence and

  15. Paleoenvironment reconstruction from channel and valley morphometry on Mars

    Science.gov (United States)

    Kereszturi, A.

    The characteristics of the channels and valleys on Mars hold information on various environmental conditions were present during their formation. This work focuses on their easily observable main morphological and morphometrical aspects from a point of view how much are they useful for paleoenvironment reconstruction. The author analyzed longitudinal and cross sectional profiles of channels and valleys at Xanthe, Margaritifer, Noachis Terra and their surroundings from MOLA data, and morphological characteristics from MOC, THEMIS and HRSC images. During the work correlations were searched between the quantitative parameters (length, width, depth, slope, volume, curvature) and the geomorphological structures (regional topography, sedimentary infill, erodible/competent bedrock, inner channels etc.). The author tried to elucidate to what extent could the channels and valleys be used for the estimation of ancient environmental parameters (erosion, paleodischarge, ice covered/ice free surfaces, cutting into bedrock, water sources and sinks etc.). Among the results concave and convex longitudinal profiles were observed at Bahram and Tyras Valles respectively, while no general trend was visible at many other valleys. Several longitudinal profiles showed signs of knickpoints and some short reaches with increasing elevation in the flow direction. The cross-sectional profiles of Tyras Valles showed more V-shaped of upper and U-shaped profiles of lower reaches, but the great variety of profiles of other channels suggests a complex relationship. Tyras Valles could be divided into upper and lower sections that probably formed at different periods and conditions. The largest observed valleys contain small, previously unnoticed inner channels. There is no correlation between the shape of cross-sectional profiles and the direction of curvature of the valley's long axis, as is found in riverbeds on the Earth, suggesting that they are probably valleys and not dry riverbeds. The

  16. The last millennia history of detrital sedimentation in the Lower Seine Valley geosystem (Normandy, NW France)

    Science.gov (United States)

    Sechi-Sapowicz, S.; Sebag, D.; Laignel, B.; Lepert, T.

    2012-04-01

    Actually, the respective role of climate and Man in the Holocene environmental changes is still debated. It is obvious that those factors are together implicated in changes in hydrological balance, soil erosion and terrigenous sedimentation. Indeed regional synthesis showed the increasing human pressure in combination to climatic variability since the Neolithic time. Thus, in Northwest Europe, increasing land use is well documented as forest clearance or alternation of deforestation and farming periods and of forest recovery episodes. In this aim, the lower valleys were particularly sensitive to changes in recent mutation and provide valuable Holocene archives to track changes in sedimentary dynamics. In this way an accentuated fine alluviation is often associated with land human activities linked to erosive processes during climatic oscillation in Northwest European valleys. In the West Paris Basin, in Normandy, France, several studies emphasized a single forcing on the Quaternary and Holocene evolution: climate changes or sea level rise or human activities in the Lower Seine Valley (LSV). Research on Holocene sequences, field, palaeoenvironnemental data and archaeological investigations from the Lower Seine Valley and tributaries result in a global vision of the erosional processes at the origin of detrital inputs and terrigenous records. Reading on those records we define three main sectors of the Lower Seine Valley: Estuarine zone, Fluvial zone and Tributaries. We define seven erosional/detrital phases directly or indirectly triggered by the increase anthropogenic pressure combined, or not, to climate change. Those phases are the key periods of changes on major terrigenous sedimentation events. During the Early Holocene climate pejoration, a deep and linear under-scour of plateaus and changes in drainage network load to the "Mesolithic detritism". Those sediments with proximal origins, were firstly recorded in the estuarine zone and after in the fluvial zone

  17. Long-term genetic stability and a high-altitude East Asian origin for the peoples of the high valleys of the Himalayan arc.

    Science.gov (United States)

    Jeong, Choongwon; Ozga, Andrew T; Witonsky, David B; Malmström, Helena; Edlund, Hanna; Hofman, Courtney A; Hagan, Richard W; Jakobsson, Mattias; Lewis, Cecil M; Aldenderfer, Mark S; Di Rienzo, Anna; Warinner, Christina

    2016-07-05

    The high-altitude transverse valleys [>3,000 m above sea level (masl)] of the Himalayan arc from Arunachal Pradesh to Ladahk were among the last habitable places permanently colonized by prehistoric humans due to the challenges of resource scarcity, cold stress, and hypoxia. The modern populations of these valleys, who share cultural and linguistic affinities with peoples found today on the Tibetan plateau, are commonly assumed to be the descendants of the earliest inhabitants of the Himalayan arc. However, this assumption has been challenged by archaeological and osteological evidence suggesting that these valleys may have been originally populated from areas other than the Tibetan plateau, including those at low elevation. To investigate the peopling and early population history of this dynamic high-altitude contact zone, we sequenced the genomes (0.04×-7.25×, mean 2.16×) and mitochondrial genomes (20.8×-1,311.0×, mean 482.1×) of eight individuals dating to three periods with distinct material culture in the Annapurna Conservation Area (ACA) of Nepal, spanning 3,150-1,250 y before present (yBP). We demonstrate that the region is characterized by long-term stability of the population genetic make-up despite marked changes in material culture. The ancient genomes, uniparental haplotypes, and high-altitude adaptive alleles suggest a high-altitude East Asian origin for prehistoric Himalayan populations.

  18. Birds of the St. Croix River valley: Minnesota and Wisconsin

    Science.gov (United States)

    Faanes, Craig A.

    1981-01-01

    The St. Croix River Valley encompasses nearly 11,550 km2 in east-central Minnesota and northwestern Wisconsin. A wide range of habitats are available for birds including upland oak, lowland deciduous, maple-basswood, lowland and upland coniferous forests, natural basin wetlands, and grasslands. Situated in the north-central region of the United States, the valley is a biological 'crossroads' for many species. Because of the mixed affinities of plant communities, the valley includes the northern and southern range limits for a number of species. Also, because the valley lies near the forest-prairie transition zone, many typical western breeding species (e.g. pintail, western meadowlark, yellow-headed blackbird) breed in proximity to typical eastern species such as tufted titmouse, eastern meadowlark, and cardinal. From 1966 to 1980, I conducted extensive surveys of avian distribution and abundance in the St. Croix River Valley. I have supplemented the results of these surveys with published and unpublished observations contributed by many ornithologists. These additional data include compilations from Christmas Bird Counts sponsored by the National Audubon Society and from the Breeding Bird Survey coordinated by the U.S. Fish and Wildlife Service. Three hundred fourteen species have been recorded in the study area; data are presented on the migration period, nesting season distribution, winter distribution, relative abundance, and habitat use of each species. Recognizing the uniqueness of the area, and its importance not only to wildlife but also to man, the U.S. Congress designated the St. Croix a National Scenic Riverway. This action provided a considerable degree of protection to lands along and directly adjacent to the river. Unfortunately, no similar legal measure exists to protect lands away from the river. With the exception of the northern quarter of the St. Croix River Valley, agricultural interests have made significant inroads into the habitat base. The

  19. Northern Sand Sea

    Science.gov (United States)

    2005-01-01

    [figure removed for brevity, see original site] Our topic for the weeks of April 4 and April 11 is dunes on Mars. We will look at the north polar sand sea and at isolated dune fields at lower latitudes. Sand seas on Earth are often called 'ergs,' an Arabic name for dune field. A sand sea differs from a dune field in two ways: 1) a sand sea has a large regional extent, and 2) the individual dunes are large in size and complex in form. This VIS image was taken at 82 degrees North latitude during Northern spring. The image is completely dominated by dunes. In sand seas, it is very common for a single type of dune to occur, and for a single predominate wind to control the alignment of the dunes. Image information: VIS instrument. Latitude 82.2, Longitude 152.5 East (207.5 West). 19 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  20. Hydrology of modern and late Holocene lakes, Death Valley, California

    Energy Technology Data Exchange (ETDEWEB)

    Grasso, D.N.

    1996-07-01

    Above-normal precipitation and surface-water runoff, which have been generally related to the cyclic recurrence of the El Nino-Southern Oscillation, have produced modern ephemeral lakes in the closed-basin Death Valley watershed. This study evaluates the regional hydroclimatic relations between precipitation, runoff, and lake transgressions in the Death Valley watershed. Recorded precipitation, runoff, and spring discharge data for the region are used in conjunction with a closed-basin, lake-water-budget equation to assess the relative contributions of water from these sources to modern lakes in Death Valley and to identify the requisite hydroclimatic changes for a late Holocene perennial lake in the valley. As part of the Yucca Mountain Site Characterization Program, an evaluation of the Quaternary regional paleoflood hydrology of the potential nuclear-waste repository site at Yucca Mountain, Nevada, was planned. The objectives of the evaluation were (1) to identify the locations and investigate the hydraulic characteristics of paleofloods and compare these with the locations and characteristics of modern floods, and (2) to evaluate the character and severity of past floods and debris flows to ascertain the potential future hazards to the potential repository during the pre-closure period (US Department of Energy, 1988). This study addresses the first of these objectives, and the second in part, by assessing and comparing the sizes, locations, and recurrence rates of modern, recorded (1962--83) floods and late Holocene paleofloods for the 8,533-mi{sup 2}, closed-basin, Death Valley watershed with its contributing drainage basins in the Yucca Mountain site area.

  1. Wintertime Atmospheric Stability and PM Variability in Valleys

    Science.gov (United States)

    Karandana Gamalathge, T. D.; Green, M.

    2016-12-01

    Air pollution has already become a global threat. Particulate Matter (PM) which is commonly known as `aerosols' plays a significant role in negatively impacting the climate and human health. PM2.5 which are particles less than aerodynamic diameter of 2.5 μm can go deeply in to human lungs and cause serious health issues. Due to trapping of pollution, people living in cities that can be considered `valleys' are subjected to higher exposure, particularly in winter when there is less dispersion due to enhanced atmospheric stability. To identify whether there are any special atmospheric conditions or geographical locations that leads to increases in PM2.5 concentrations, we have gathering radiosonde data and PM2.5 data for cities within valleys. Although radiosonde archives consist of multi-decadal data and are easily accessible, it has been a difficult task to collect air quality data. Most of the developed countries have provided public access to their data bases, but different cities have measurements in different temporal resolutions. Apart from that, valleys to be used in our work should have both atmospheric soundings and air quality monitoring stations that are close together. Despite these constraints, we have selected about 100 cities which geographically represent various valley configurations (e.g. width, depth) and are in the process of categorizing them. We are limiting our work to winter season in each city and our goal is to see whether there are globally common relationships between atmospheric stability and PM variability. Initial results for a subset of cities are presented. Keywords: PM2.5, Valleys, Radiosonde data, Atmospheric stability

  2. Nature of the Lowstand Surface on the Gulf of Cádiz Shelf and the Guadiana Incised-Valley System: Preliminary Results from the LASEA 2013 Cruise

    Science.gov (United States)

    Lobo, F.; Lebreiro, S.; Antón, L.; Delivet, S.; Espinosa, S.; Fernández-Puga, M. C.; García, M.; Ibáñez, J.; Luján, M.; Mendes, I.; Reguera, M. I.; Sevillano, P.; Sinde, C.; Van Rooij, D.; Zarandona, P.

    2014-12-01

    The LASEA 2013 cruise was executed in August 2013 in the northern margin of the Gulf of Cádiz, with the main goal of collecting data from the Guadiana River-influenced shelf, in order to: (1) study changes affecting the entire drainage basin; (2) correlate shelf unit sequences with the upper slope sedimentary record, composed dominantly of contourite deposits in specific stretches of the margin. As a first approach, attention is paid to the most obvious sedimentary manifestation of the influence of the river on the shelf domain, represented by the Guadiana incised-valley system. The database comprises both geophysical and sedimentological records. Geophysical data include multibeam bathymetry, TOPAS profiles and single-channel Sparker seismic profiles. Sedimentological data include sediment cores collected with gravity- and vibro-corer devices. The lowstand erosional surface was mapped across the shelf. The lowstand surface exhibits two clearly contrasting patterns. In the outer shelf the surface isrepresented by an erosional truncation that can be planar or irregular. The lowstand surface is much more difficult to follow in the inner shelf, due to the amalgamation of erosional surfaces and the frequent stacking of coarse-grained deposits. Incised valleys are recognized at shallow waters (20-30 m) the most significant of them is at least 1.5 km wide in the most proximal (recognized) section, decreasing seawards in width. The internal architecture of the valley exhibits the intercalation of laterally prograding sediment bodies and high-amplitude, subparallel configurations laterally related to valley margin prograding wedges. The internal facies architecture suggests a transition from relatively high-energy fluvial to proximal estuarine environment to a lower-energy estuarine depositional environment. Thus, the study of the valley extension into the shelf is expected to provide clues for the recent reorganization of the entire fluvial system, during the course of

  3. Anthropogenic Influence On Groundwater Quality In Jericho and And Adjoining Wadis (Lower Jordan Valley, Palestine)

    Science.gov (United States)

    Geyer, S.; Khayat, S.; Roediger, T.; Siebert, C.

    2008-12-01

    The Lower Jordan Valley is part of the Jordan-Dead Sea Rift. The graben is filled by sedmiments of limnological and marine origin. Towards the Dead Sea, the occurance of gipseous and salty sediments on the valley floor increase. The southern part of the Lower Jordan Valley, where the city of Jericho is situated, is an arid area (<150 mm precipitation/year), with less amount of exploitable fresh groundwater or surface water. Jericho was founded on an alluvial fan, closely to the western mountain range in front of mouth of Wadi Qilt. The fan serves as reservoir for infiltrating water from wadi runoff and groundwater from the crataceous aquifers of the western shoulder. The fan is surrounded by unsuitable aquifers of the graben, which are filled with saline water. The aim of this study, which takes place inside the multilateral SMART-project, is to understand the vulnerability of the Jericho groundwater aquifers in connection with lowering the groundwater table by overexploitation and the intensively use of pesticides Jericho and its vicinity are of most importance for the Palestinians. However, beside the about 25,000 residents, the tourism industry and the vital agriculture depend on sufficient and expoitable fresh water resources. Because the demand of water is increasing, overexpoitaion takes place. Due to over extraction of groundwater a huge depression cone is evolving during the dry season which is filled up again according to the groundwater recharge in the rainy season. Concomitantly, depression cone in the fresh water aquifers leads to an infiltration of the surrounding saltwater. The amount of saltwater which infiltrates into the freshwater resource was calculated by different stable isotope methods (d2H, d18O) and hydrochemical analyses of wellwater. The agriculture is main consumer of groundwater - over 60% of the pumped water is used for inefficient irrigation. Additionally, an intensive use of pesticides in concentrated liquid and gaseous forms for

  4. Geophysical Data from Spring Valley to Delamar Valley, East-Central Nevada

    Science.gov (United States)

    Mankinen, Edward A.; Roberts, Carter W.; McKee, Edwin H.; Chuchel, Bruce A.; Morin, Robert L.

    2007-01-01

    Cenozoic basins in eastern Nevada and western Utah constitute major ground-water recharge areas in the eastern part of the Great Basin and these were investigated to characterize the geologic framework of the region. Prior to these investigations, regional gravity coverage was variable over the region, adequate in some areas and very sparse in others. Cooperative studies described herein have established 1,447 new gravity stations in the region, providing a detailed description of density variations in the middle to upper crust. All previously available gravity data for the study area were evaluated to determine their reliability, prior to combining with our recent results and calculating an up-to-date isostatic residual gravity map of the area. A gravity inversion method was used to calculate depths to pre-Cenozoic basement rock and estimates of maximum alluvial/volcanic fill in the major valleys of the study area. The enhanced gravity coverage and the incorporation of lithologic information from several deep oil and gas wells yields a much improved view of subsurface shapes of these basins and provides insights useful for the development of hydrogeologic models for the region.

  5. Mitochondrial DNA structure in North Africa reveals a genetic discontinuity in the Nile Valley.

    Science.gov (United States)

    Fadhlaoui-Zid, Karima; Rodríguez-Botigué, Laura; Naoui, Nejib; Benammar-Elgaaied, Amel; Calafell, Francesc; Comas, David

    2011-05-01

    Human population movements in North Africa have been mostly restricted to an east-west direction due to the geographical barriers imposed by the Sahara Desert and the Mediterranean Sea. Although these barriers have not completely impeded human migrations, genetic studies have shown that an east-west genetic gradient exists. However, the lack of genetic information of certain geographical areas and the focus of some studies in parts of the North African landscape have limited the global view of the genetic pool of North African populations. To provide a global view of the North African genetic landscape and population structure, we have analyzed ∼2,300 North African mitochondrial DNA lineages (including 269 new sequences from Libya, in the first mtDNA study of the general Libyan population). Our results show a clinal distribution of certain haplogroups, some of them more frequent in Western (H, HV0, L1b, L3b, U6) or Eastern populations (L0a, R0a, N1b, I, J) that might be the result of human migrations from the Middle East, sub-Saharan Africa, and Europe. Despite this clinal pattern, a genetic discontinuity is found in the Libyan/Egyptian border, suggesting a differential gene flow in the Nile River Valley. Finally, frequency of the post-LGM subclades H1 and H3 is predominant in Libya within the H sequences, highlighting the magnitude of the LGM expansion in North Africa. Copyright © 2011 Wiley-Liss, Inc.

  6. Pleistocene environments and glacial history of the northern North Sea

    Science.gov (United States)

    Reinardy, Benedict; Hjelstuen, Berit; Petter Sejrup, Hans; Augedal, Hans; Jørstad, Arild

    2017-04-01

    Based on new geochronological and lithological data combined with analyses of 3D seismic data, the Pliocene-Pleistocene development of the central northern North Sea has been investigated. At the start of the Plio-Pleistocene Transition the study area was dominated by a deltaic, shallow marine or tidal depositional environment with sediments mainly sourced from the west with a local provenance. Directly above the base Quaternary a 60 m thick layer of mud-rich sediments of glacimarine origin were deposited at a rate of 12 cm/ka between 2-1.5 Ma and up to 80 cm/ka between 1.5 - 1.2 Ma possibly reflecting glacial ice advancing to the Norwegian coastline. The high rate of deposition in the Early Pleistocene occurred immediately before the initiation of the Norwegian Channel Ice Stream at 1.1 Ma. Following this, a large part of the sediment input from Fennoscandia seems to have been directed away from the study area to the shelf break. At the start of the Mid Pleistocene Transition (MPT), subaerial conditions allowed the formation of a >50 km long fluvial channel across the study area draining water from the east to the south west. The earliest evidence of grounded ice in the investigated area comes from mega scale glacial lineations formed during the MPT, at or just after 1.2 Ma. Following this, a regional unconformity was formed by one or more grounded ice advances across the study area possibly during or directly after the MPT and likely marks the boundary between the Early and Mid Pleistocene glacimarine sediments. The Mid to Late Pleistocene stratigraphy is dominated by glacimarine sediments and tills and is associated with multiple generations of tunnel valleys observed within the seismic data. A high shear strength till containing chalk clasts transported from the west and/or south of the study area was likely deposited during MIS6 and may have been more conducive to tunnel valley formation in comparison to lower shear strength tills deposited by later ice

  7. Retreat patterns and dynamics of the Sentralbankrenna glacial system, central Barents Sea

    Science.gov (United States)

    Esteves, Mariana; Bjarnadóttir, Lilja R.; Winsborrow, Monica C. M.; Shackleton, Calvin S.; Andreassen, Karin

    2017-08-01

    The Barents Sea Ice Sheet (BSIS) is a good palaeo-analogue for the present day West Antarctic Ice Sheet. Both were marine-based ice sheets, particularly vulnerable to ocean warming and sea-level rise. Understanding the BSIS ice dynamics and patterns of retreat since the Last Glacial Maximum (LGM) is useful in developing our knowledge of spatial and temporal variations during marine-based ice sheet retreat. While the western margins of the Barents Sea have been extensively studied, few studies have focused on the central regions, which hosted key ice stream tributaries and major ice domes and divides. Presenting a new high-resolution (5 m) bathymetric dataset, this glacial geomorphological study focuses on the Sentralbankrenna palaeo-glacial system in the central Barents Sea. A large number of grounding zone wedges, mega-scale glacial lineations and areas with tunnel valleys and palaeo-subglacial basins were identified. These form the basis for a six-stage reconstruction of ice stream retreat through deglaciation since the LGM. In reconstructing the retreat of the Sentralbankrenna Ice Stream, we document the rapid but highly spatially variable pattern of retreat of a marine-based ice sheet margin. The presence of several tunnel valleys and interconnected palaeo-subglacial basin systems indicates an abundance of meltwater, likely to have been stored and released through several discharge events, significantly influencing the ice stream margin dynamics. This study provides insight into the behaviour and dynamics of ice during the late stages of the BSIS deglaciation within the central Barents Sea, increasing our understanding of grounding line processes.

  8. Meteorological control of air pollution in a complex topography, high-altitude valley in the Tropical Andes

    Science.gov (United States)

    Jimenez Pizarro, R.; Arango, C. D.; Peña, J. A.

    2011-12-01

    About two-thirds of the Latin-American population lives on the Andes. In Colombia, 70% of the population lives at altitudes over 1 km above the sea level (ASL) on a complex topography 3 Andean mountain-chain system. Understanding and properly modeling air pollution in the Tropical Andes is thus a challenging task not just because of the complexity of horizontal and vertical transport in the Intertropical Convergence Zone but because of the strong influence of regional- and local-scale circulation phenomena. The Sogamoso Valley (5 degrees 43' N, 72 degrees 55' W, 2570 m ASL), located on the Colombian Andes Eastern Mountain Chain, is one of the most industrialized regions of Colombia. Air quality in this region is affected by a heterogeneous group of emission sources, which include truck traffic, heavy industry (including steelworks and cement), medium- and small-scale industry, and around 600 low-technology, highly polluting brick and quicklime production furnaces. 24-h average PM10 concentrations frequently double the Colombian standard (150 μg/m3). Measurements and analysis conducted in 2002 found that relatively rapid changes in the regional atmospheric circulation patterns strongly influence the Sogamoso Valley air quality, including drastic PM10 concentration variations observed during periods of fairly steady emissions. The strong linear dependence of the daily temperature variation amplitude and the maximum wind speed on the daily accumulated solar radiation suggests that air quality is ultimately determined by the synoptic activation of local and mesoscale circulation patterns and meteorological conditions, including mountain and valley winds, strong anabatic and katabatic winds from the lowlands (at both sides of the Colombian Andes Eastern Mountain Chain), channeling, and radiative cooling temperature inversion. During clear sky periods, katabatic advection of pollution from furnaces on the foothills resulted in recurrent nocturnal pollution episodes with

  9. Yellowstone and Long Valley - A Comparison of Two Restless Calderas

    Science.gov (United States)

    Hill, D. P.; Smith, R. B.

    2007-12-01

    Three large, silicic calderas in the conterminous United States have explosively erupted volumes > 300 km3 within in the last 2 million years -- Yellowstone caldera (Wyoming) Long Valley caldera (California) and the Vallez caldera (New Mexico) all located in extensional tectonic environments. All have shown varying levels of historic unrest. Pronounced unrest episodes at Yellowstone and Long Valley calderas over the past three decades stimulated extensive research on these two closely monitored calderas, and we explore some emerging similarities and differences. Yellowstone caldera is underlain by a long-lived (> 17 my) upper-mantle hot-spot that has fed a series of caldera-forming, extending to the southwest across southern Idaho to central Oregon including three caldera-forming eruptions from the Yellowstone caldera system in the last 2 my, the most recent at 600,000 ybp. It is marked by relatively low density and low seismic velocities extending to depths of at least 400 km and a regional topographic swell with elevations exceeding 2000 m. The extensive Yellowstone hydrothermal system has a thermal output of 5 GW. The most recent magmatic eruption dated at 70,000 ybp. By comparison, Long Valley caldera is underlain by a relatively modest "hot-spot", the locus of which appears to be influenced by a dilatational jog between the dextral Eastern California Shear Zone and the Walker Lane and westward delamination of the dense lithospheric root of the adjacent Sierra Nevada. The Long Valley system has fed multiple eruptions of over the past 4 my and a single caldera-forming eruption at 760,000 ybp. It is marked by a limited topographic swell but with the elevation of the caldera floor and adjacent basins comparable to the 2000-plus m elevation of the Yellowstone swell. Long Valley caldera hydrothermal system has a thermal output of 0.3 GW (including a 40 MW geothermal power plant). The most recent eruptions from the Long Valley Caldera- Mono Domes volcanic field

  10. The North Sea - A shelf sea in the Anthropocene

    Science.gov (United States)

    Emeis, Kay-Christian; van Beusekom, Justus; Callies, Ulrich; Ebinghaus, Ralf; Kannen, Andreas; Kraus, Gerd; Kröncke, Ingrid; Lenhart, Hermann; Lorkowski, Ina; Matthias, Volker; Möllmann, Christian; Pätsch, Johannes; Scharfe, Mirco; Thomas, Helmuth; Weisse, Ralf; Zorita, Eduardo

    2015-01-01

    Global and regional change clearly affects the structure and functioning of ecosystems in shelf seas. However, complex interactions within the shelf seas hinder the identification and unambiguous attribution of observed changes to drivers. These include variability in the climate system, in ocean dynamics, in biogeochemistry, and in shelf sea resource exploitation in the widest sense by societies. Observational time series are commonly too short, and resolution, integration time, and complexity of models are often insufficient to unravel natural variability from anthropogenic perturbation. The North Sea is a shelf sea of the North Atlantic and is impacted by virtually all global and regional developments. Natural variability (from interannual to multidecadal time scales) as response to forcing in the North Atlantic is overlain by global trends (sea level, temperature, acidification) and alternating phases of direct human impacts and attempts to remedy those. Human intervention started some 1000 years ago (diking and associated loss of wetlands), expanded to near-coastal parts in the industrial revolution of the mid-19th century (river management, waste disposal in rivers), and greatly accelerated in the mid-1950s (eutrophication, pollution, fisheries). The North Sea is now a heavily regulated shelf sea, yet societal goals (good environmental status versus increased uses), demands for benefits and policies diverge increasingly. Likely, the southern North Sea will be re-zoned as riparian countries dedicate increasing sea space for offshore wind energy generation - with uncertain consequences for the system's environmental status. We review available observational and model data (predominantly from the southeastern North Sea region) to identify and describe effects of natural variability, of secular changes, and of human impacts on the North Sea ecosystem, and outline developments in the next decades in response to environmental legislation, and in response to

  11. Armada puts to sea

    Energy Technology Data Exchange (ETDEWEB)

    Esau, I.

    1995-04-01

    This article describes the operational success of British Gas in exploiting the Armada gas field. Armada consists of three separate reservoirs (Fleming, Drake and Hawkins) and lies in the central North Sea. British Gas has successfully exploited this field on behalf of a group of co-venturers. This article describes the economic, technical and political difficulties faced by the company in operating this innovative method of management. (UK)

  12. Deep-sea fungi

    Digital Repository Service at National Institute of Oceanography (India)

    Raghukumar, C.; Damare, S.

    pressure of 10 MPa (73). Several species of Aspergillus showed abnonnal morphology immediately afterisola~ tion. These showed extremely long conidiophores with vesicles that were covered with long hyphae, instead of phialides or metulae or conidia... at SoC and pH 9.0 (17). In contrast, out of 22 fungi isolated from shallow \\vater, only 14% showed Iow-temperature-active protease production. The deep-sea fungi when grown under elevated pressure synthesized extracellular protease, albeit in very low...

  13. Updated glacial chronology of the South Fork Hoh River valley, Olympic Peninsula, Washington through detailed stratigraphy and OSL dating

    OpenAIRE

    Wyshnytzky, Cianna E.; Rittenour, Tammy M.; Thackray, Glenn D.

    2012-01-01

    Four glacial advances are preserved and exposed in the stratigraphy of the South Fork Hoh River valley. The oldest of these advances extended beyond the South Fork valley into the Hoh River valley. The three younger advances are preserved in the stratigraphy cut bank exposures in the valley and geomorphically by moraines and outwash plains. One of these advances represents a re-advance to the same terminal position of the previous advance and has not previously been recognized in this valley ...

  14. Case histories of West Valley spent fuel shipments: Final report

    Energy Technology Data Exchange (ETDEWEB)

    1987-01-01

    In 1983, NRC/FC initiated a study on institutional issues related to spent fuel shipments originating at the former spent fuel processing facility in West Valley, New York. FC staff viewed the shipment campaigns as a one-time opportunity to document the institutional issues that may arise with a substantial increase in spent fuel shipping activity. NRC subsequently contracted with the Aerospace Corporation for the West Valley Study. This report contains a detailed description of the events which took place prior to and during the spent fuel shipments. The report also contains a discussion of the shipment issues that arose, and presents general findings. Most of the institutional issues discussed in the report do not fall under NRC's transportation authority. The case histories provide a reference to agencies and other institutions that may be involved in future spent fuel shipping campaigns. 130 refs., 7 figs., 19 tabs.

  15. The Virtual Museum of the Tiber Valley Project

    Directory of Open Access Journals (Sweden)

    Antonia Arnoldus Huyzendveld

    2012-11-01

    Full Text Available The aim of the Virtual Museum of the Tiber Valley project is the creation of an integrated digital system for the knowledge, valorisation and communication of the cultural landscape, archaeological and naturalistic sites along the Tiber Valley, in the Sabina area between Monte Soratte and the ancient city of Lucus Feroniae (Capena. Virtual reality applications, multimedia contents, together with a web site, are under construction and they will be accessed inside the museums of the territory and in a central museum in Rome. The different stages of work will cover the building of a geo-spatial archaeological database, the reconstruction of the ancient potential landscape and the creation of virtual models of the major archaeological sites. This paper will focus on the methodologies used and on present and future results.

  16. Laboratory work in support of West Valley glass development

    Energy Technology Data Exchange (ETDEWEB)

    Bunnell, L.R.

    1988-05-01

    Over the past six years, Pacific Northwest Laboratory (PNL) has conducted several studies in support of waste glass composition development and testing of glass compositions suitable for immobilizing the nuclear wastes stored at West Valley, New York. As a result of pilot-scale testing conducted by PNL, the glass composition was changed from that originally recommended in response to changes in the waste stream, and several processing-related problems were discovered. These problems were solved, or sufficiently addressed to determine their likely effect on the glass melting operations to be conducted at West Valley. This report describes the development of the waste glass composition, WV-205, and discusses solutions to processing problems such as foaming and insoluble sludges, as well as other issues such as effects of feed variations on processing of the resulting glass. An evaluation of the WV-205 glass from a repository perspective is included in the appendix to this report.

  17. Hydrogeologic framework of the Santa Clara Valley, California

    Science.gov (United States)

    Hanson, Randall T.

    2015-01-01

    The hydrologic framework of the Santa Clara Valley in northern California was redefined on the basis of new data and a new hydrologic model. The regional groundwater flow systems can be subdivided into upper-aquifer and lower-aquifer systems that form a convergent flow system within a basin bounded by mountains and hills on three sides and discharge to pumping wells and the southern San Francisco Bay. Faults also control the flow of groundwater within the Santa Clara Valley and subdivide the aquifer system into three subregions.After decades of development and groundwater depletion that resulted in substantial land subsidence, Santa Clara Valley Water District (SCVWD) and the local water purveyors have refilled the basin through conservation and importation of water for direct use and artificial recharge. The natural flow system has been altered by extensive development with flow paths toward major well fields. Climate has not only affected the cycles of sedimentation during the glacial periods over the past million years, but interannual to interdecadal climate cycles also have affected the supply and demand components of the natural and anthropogenic inflows and outflows of water in the valley. Streamflow has been affected by development of the aquifer system and regulated flow from reservoirs, as well as conjunctive use of groundwater and surface water. Interaquifer flow through water-supply wells screened across multiple aquifers is an important component to the flow of groundwater and recapture of artificial recharge in the Santa Clara Valley. Wellbore flow and depth-dependent chemical and isotopic data indicate that flow into wells from multiple aquifers, as well as capture of artificial recharge by pumping of water-supply wells, predominantly is occurring in the upper 500 ft (152 m) of the aquifer system. Artificial recharge represents about one-half of the inflow of water into the valley for the period 1970–1999. Most subsidence is occurring below 250 ft

  18. Ambient Radon-222 Monitoring in Amargosa Valley, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    L.H. Karr; J.J. Tappen; D. Shafer; K.J. Gray

    2008-06-05

    As part of a program to characterize and baseline selected environmental parameters in the region around the proposed repository at Yucca Mountain, Nevada, ambient radon-222 monitoring was conducted in the rural community of Amargosa Valley, the community closest to the proposed repository site. Passive integrating radon monitors and a continuous radon monitoring instrument were deployed adjacent to the Community Environmental Monitoring Program (CEMP) (http://www.cemp.dri.edu/index.html) station located in the Amargosa Valley Community Center near the library. The CEMP station provided real-time ambient gamma exposure and meteorological data used to correct the integrated radon measurements as well as verify meteorological data collected by the continuous radon monitoring instrument. Additionally, different types of environmental enclosures that housed the monitors and instrument were used to determine if particular designs influenced the ambient radon measurements.

  19. Metallic iron for water treatment: leaving the valley of confusion

    Science.gov (United States)

    Makota, Susanne; Nde-Tchoupe, Arnaud I.; Mwakabona, Hezron T.; Tepong-Tsindé, Raoul; Noubactep, Chicgoua; Nassi, Achille; Njau, Karoli N.

    2017-07-01

    Researchers on metallic iron (Fe0) for environmental remediation and water treatment are walking in a valley of confusion for 25 years. This valley is characterized by the propagation of different beliefs that have resulted from a partial analysis of the Fe0/H2O system as (1) a reductive chemical reaction was considered an electrochemical one and (2) the mass balance of iron has not been really addressed. The partial analysis in turn has been undermining the scientific method while discouraging any real critical argumentation. This communication re-establishes the complex nature of the Fe0/H2O system while recalling that, finally, proper system analysis and chemical thermodynamics are the most confident ways to solve any conflicting situation in Fe0 environmental remediation.

  20. Valley blockade in a silicon double quantum dot

    Science.gov (United States)

    Perron, Justin K.; Gullans, Michael J.; Taylor, Jacob M.; Stewart, M. D.; Zimmerman, Neil M.

    2017-11-01

    Electrical transport in double quantum dots (DQDs) illuminates many interesting features of the dots' carrier states. Recent advances in silicon quantum information technologies have renewed interest in the valley states of electrons confined in silicon. Here we show measurements of dc transport through a mesa-etched silicon double quantum dot. Comparing bias triangles (i.e., regions of allowed current in DQDs) at positive and negative bias voltages we find a systematic asymmetry in the size of the bias triangles at the two bias polarities. Asymmetries of this nature are associated with blocked tunneling events due to the occupation of a metastable state. Several features of our data lead us to conclude that the states involved are not simple spin states. Rather, we develop a model based on selective filling of valley states in the DQD that is consistent with all of the qualitative features of our data.