Sample records for valley dispersion sites

  1. Dispersion of Perfluorocarbon Tracers within the Salt Lake Valley during VTMX 2000

    NASA Astrophysics Data System (ADS)

    Fast, Jerome D.; Allwine, K. Jerry; Dietz, Russell N.; Clawson, Kirk L.; Torcolini, Joel C.

    2006-06-01

    Six perfluorocarbon tracer experiments were conducted in Salt Lake City, Utah, during October 2000 as part of the Vertical Transport and Mixing (VTMX) field campaign. Four tracers were released at different sites to obtain information on dispersion during stable conditions within down-valley flow, canyon outflow, and interacting circulations in the downtown area. Some of the extensive tracer data that were collected are presented in the context of the meteorological field campaign measurements. Tracer measurements at building-top sites in the downtown area and along the lower slopes of the Wasatch Front indicated that vertical mixing processes transported material up to at least 180 m above the valley floor, although model simulations suggest that tracers were transported upward to much higher elevations. Tracer data provided evidence of downward mixing of canyon outflow, upward mixing within down-valley flow, horizontal transport above the surface stable layer, and transport within horizontal eddies produced by the interaction of canyon and down-valley flows. Although point meteorological measurements are useful in evaluating the forecasts produced by mesoscale models, the tracer data provide valuable information on how the time-varying three-dimensional mean and turbulent motions over urban and valley spatial scales affect dispersion. Although the mean tracer transport predicted by the modeling system employed in this study was qualitatively similar to the measurements, improvements are needed in the treatment of turbulent vertical mixing.

  2. Chuckwalla Valley multiple-well monitoring site, Chuckwalla Valley, Riverside County

    USGS Publications Warehouse

    Everett, Rhett

    2013-01-01

    The U.S. Geological Survey (USGS), in cooperation with the Bureau of Land Management, is evaluating the geohydrology and water availability of the Chuckwalla Valley, California. As part of this evaluation, the USGS installed the Chuckwalla Valley multiple-well monitoring site (CWV1) in the southeastern portion of the Chuckwalla Basin. Data collected at this site provide information about the geology, hydrology, geophysics, and geochemistry of the local aquifer system, thus enhancing the understanding of the geohydrologic framework of the Chuckwalla Valley. This report presents construction information for the CWV1 multiple-well monitoring site and initial geohydrologic data collected from the site.

  3. Raccoon (Procyon lotor) movements and dispersal associated with ridges and valleys of Pennsylvania: implications for rabies management.

    PubMed

    Puskas, Robert B; Fischer, Justin W; Swope, Craig B; Dunbar, Mike R; McLean, Robert G; Root, J Jeffrey

    2010-12-01

    The raccoon (Procyon lotor) continues to be a prominent terrestrial rabies reservoir in the eastern United States. Describing the dispersal and movements of these animals and determining geographic features that are natural hindrances or corridors to movements could be used to assist oral rabies vaccination efforts. The landscape of the ridge-and-valley system in Pennsylvania exhibits characteristics of both natural potential hindrances and travel corridors to the movements of wildlife. The movements of 49 raccoons were monitored throughout a ridge and two adjacent valley sites to assess their movements related to these landscape features. Results suggest that few raccoons cross the ridge we studied over the short-term and that long-distance movements of these animals are uncommon in this region. Consequently, movement corridors within the ridge were largely confined to spur valleys within the ridge system. These results may be useful in strategic oral rabies vaccination programs in Pennsylvania and other areas where natural hindrances and travel corridors to movement are identified.

  4. Corrective Action Plan for Corrective Action Unit 366: Area 11 Plutonium Valley Dispersion Sites, Nevada National Security Site, Nevada

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    None

    This Corrective Action Plan has been prepared for Corrective Action Unit (CAU) 366, Area 11 Plutonium Valley Dispersion Sites, in accordance with the Federal Facility Agreement and Consent Order (FFACO, 1996 as amended). CAU 366 consists of the following six Corrective Action Sites (CASs) located in Area 11 of the Nevada National Security Site: · CAS 11-08-01, Contaminated Waste Dump #1 · CAS 11-08-02, Contaminated Waste Dump #2 · CAS 11-23-01, Radioactively Contaminated Area A · CAS 11-23-02, Radioactively Contaminated Area B · CAS 11-23-03, Radioactively Contaminated Area C · CAS 11-23-04, Radioactively Contaminated Area D Site characterization activities weremore » performed in 2011 and 2012, and the results are presented in Appendix A of the Corrective Action Decision Document (CADD) for CAU 366 (U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office [NNSA/NSO], 2012a). The following closure alternatives were recommended in the CADD: · No further action for CAS 11-23-01 · Closure in place for CASs 11-08-01, 11-08-02, 11-23-02, 11-23-03, and 11-23-04 The scope of work required to implement the recommended closure alternatives includes the following: · Non-engineered soil covers approximately 3 feet thick will be constructed at CAS 11-08-01 over contaminated waste dump (CWD) #1 and at CAS 11-08-02 over CWD #2. · FFACO use restrictions (URs) will be implemented for the areas where the total effective dose (TED) exceeds the final action level (FAL) of 25 millirems per Occasional Use Area year (mrem/OU-yr). The FAL is based on an assumption that the future use of the site includes occasional work activities and that workers will not be assigned to the area on a regular basis. A site worker under this scenario is assumed to be on site for a maximum of 80 hours per year for 5 years. The FFACO UR boundaries will encompass the areas where a worker would be exposed to 25 millirems of radioactivity per year if they are present

  5. Site observational work plan for the UMTRA Project site at Monument Valley, Arizona

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    NONE

    1995-09-01

    The site observational work plan (SOWP) for the Monument Valley, Arizona, US Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project site is one of the first site-specific documents developed to achieve ground water compliance at the site. This SOWP applies information about the Monument Valley site to a regulatory compliance framework that identifies strategies that could be used to meet ground water compliance. The compliance framework was developed in the UMTRA Ground Water programmatic environmental impact statement (DOE, 1995). The DOE`s goal is to implement a cost-effective site strategy that complies with the US Environmental Protection Agencymore » (EPA) ground water standards and protects human health and the environment. The compliance strategy that emerges in the final version of the SOWP will assess potential environmental impacts and provide stakeholder a forum for review and comment. When the compliance strategy is acceptable, it will be detailed in a remedial action plan that will be subject to review by the state and/or tribe and concurrence by the US Nuclear Regulatory Commission (NRC). Information available for the preparation of this SOWP indicates active remediation is the most likely compliance strategy for the Monument Valley site. Additional data are needed to determine the most effective remediation technology.« less

  6. Liquefaction sites, Imperial Valley, California.

    USGS Publications Warehouse

    Youd, T.L.; Bennett, M.J.

    1983-01-01

    Sands that did and did not liquefy at two sites during the 1979 Imperial Valley, Calif., earthquake (ML = 6.6) are identified and their properties evaluated. SPT tests were used to evaluate liquefaction susceptibility. Loose fine sands in an abandoned channel liquefied and produced sand boils, ground fissures, and a lateral spread at the Heber Road sites. Evidence of liquefaction was not observed over moderately dense over-bank sand east of the channel nor over dense point-bar sand to the west. -from ASCE Publications Information

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

    USGS Publications Warehouse

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

    2011-01-01

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

  8. Site characterization at the Rabbit Valley Geophysical Performance Evaluation Range

    NASA Astrophysics Data System (ADS)

    Koppenjan, S.,; Martinez, M.

    The United States Department of Energy (US DOE) is developing a Geophysical Performance Evaluation Range (GPER) at Rabbit Valley located 30 miles west of Grand Junction, Colorado. The purpose of the range is to provide a test area for geophysical instruments and survey procedures. Assessment of equipment accuracy and resolution is accomplished through the use of static and dynamic physical models. These models include targets with fixed configurations and targets that can be re-configured to simulate specific specifications. Initial testing (1991) combined with the current tests at the Rabbit Valley GPER will establish baseline data and will provide performance criteria for the development of geophysical technologies and techniques. The US DOE's Special Technologies Laboratory (STL) staff has conducted a Ground Penetrating Radar (GPR) survey of the site with its stepped FM-CW GPR. Additionally, STL contracted several other geophysical tests. These include an airborne GPR survey incorporating a 'chirped' FM-CW GPR system and a magnetic survey with a surfaced-towed magnetometer array unit Ground-based and aerial video and still frame pictures were also acquired. STL compiled and analyzed all of the geophysical maps and created a site characterization database. This paper discusses the results of the multi-sensor geophysical studies performed at Rabbit Valley and the future plans for the site.

  9. Maja Valley and the Chryse outflow complex sites

    NASA Technical Reports Server (NTRS)

    Rice, Jim W.

    1994-01-01

    This candidate landing site is located at 19 deg N, 53.5 deg W near the mouth of a major outflow channel. Maja Valles, and two 'valley network' channel systems, Maumee and Vedra Valles. The following objectives are to be analyzed in this region: (1) origin and paleohydrology of outflow and valley network channels; (2) fan delta complex composition (the deposit located in this area is one of the few identified at the mouth s of any channels on the planet); and (3) analysis of any paleolake sediments (carbonates, evaporites). The primary objectives of the Chryse Outflow Complex region (Ares, Tiu, Mawrth, Simud, and Shalbatana Valles) would be outflow channel dynamics (paleohydrology) of five different channel systems.

  10. Site characterization at the Rabbit Valley Geophysical Performance Evaluation Range

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Koppenjan, S,; Martinez, M.

    1994-06-01

    The United States Department of Energy (US DOE) is developing a Geophysical Performance Evaluation Range (GPER) at Rabbit Valley located 30 miles west of Grand Junction, Colorado. The purpose of the range is to provide a test area for geophysical instruments and survey procedures. Assessment of equipment accuracy and resolution is accomplished through the use of static and dynamic physical models. These models include targets with fixed configurations and targets that can be re-configured to simulate specific specifications. Initial testing (1991) combined with the current tests at the Rabbit Valley GPER will establish baseline data and will provide performance criteriamore » for the development of geophysical technologies and techniques. The US DOE`s Special Technologies Laboratory (STL) staff has conducted a Ground Penetrating Radar (GPR) survey of the site with its stepped FM-CW GPR. Additionally, STL contracted several other geophysical tests. These include an airborne GPR survey incorporating a ``chirped`` FM-CW GPR system and a magnetic survey with a surfaced-towed magnetometer array unit Ground-based and aerial video and still frame pictures were also acquired. STL compiled and analyzed all of the geophysical maps and created a site characterization database. This paper discusses the results of the multi-sensor geophysical studies performed at Rabbit Valley and the future plans for the site.« less

  11. Hazardous Waste Cleanup: RBH Dispersions Incorporated in Bound Brook, New Jersey

    EPA Pesticide Factsheets

    RBH Dispersions, Inc. is located at L-5 Factory Lane in Bound Brook, New Jersey. The site is also known as the former Inmont Bound Brook facility. The site is bounded by Lehigh Valley Railroad to the north, the Port Reading Railroad to the south, and other

  12. Reconstructing late Pliocene to middle Pleistocene Death Valley lakes and river systems as a test of pupfish (Cyprinodontidae) dispersal hypotheses

    USGS Publications Warehouse

    Knott, J.R.; Machette, M.N.; Klinger, R.E.; Sarna-Wojcicki, A. M.; Liddicoat, J.C.; Tinsley, J. C.; David, B.T.; Ebbs, V.M.

    2008-01-01

    During glacial (pluvial) climatic periods, Death Valley is hypothesized to have episodically been the terminus for the Amargosa, Owens, and Mojave Rivers. Geological and biological studies have tended to support this hypothesis and a hydrological link that included the Colorado River, allowing dispersal of pupfish throughout southeastern California and western Nevada. Recent mitochondrial deoxyribonucleic acid (mtDNA) studies show a common pupfish (Cyprinodontidae) ancestry in this region with divergence beginning 3-2 Ma. We present tephrochronologic and paleomagnetic data in the context of testing the paleohydrologic connections with respect to the common collection point of the Amargosa, Owens, and Mojave Rivers in Death during successive time periods: (1) the late Pliocene to early Pleistocene (3-2 Ma), (2) early to middle Pleistocene (1.2-0.5 Ma), and (3) middle to late Pleistocene (<0.70.03 Ma; paleolakes Manly and Mojave). Using the 3.35 Ma Zabriskie Wash tuff and 3.28 Ma Nomlaki Tuff Member of the Tuscan and Tehama Formations, which are prominent marker beds in the region, we conclude that at 3-2 Ma, a narrow lake occupied the ancient Furnace Creek Basin and that Death Valley was not hydrologically connected with the Amargosa or Mojave Rivers. A paucity of data for Panamint Valley does not allow us to evaluate an Owens River connection to Death Valley ca. 3-2 Ma. Studies by others have shown that Death Valley was not hydrologically linked to the Amargosa, Owens, or Mojave Rivers from 1.2 to 0.5 Ma. We found no evidence that Lake Manly flooded back up the Mojave River to pluvial Lake Mojave between 0.18 and 0.12 Ma, although surface water flowed from the Amargosa and Owens Rivers to Death Valley at this time. There is also no evidence for a connection of the Owens, Amargosa, or Mojave Rivers to the Colorado River in the last 3-2 m.y. Therefore, the hypothesis that pupfish dispersed or were isolated in basins throughout southeastern California and western

  13. Between-Site Differences in the Scale of Dispersal and Gene Flow in Red Oak

    PubMed Central

    Moran, Emily V.; Clark, James S.

    2012-01-01

    Background Nut-bearing trees, including oaks (Quercus spp.), are considered to be highly dispersal limited, leading to concerns about their ability to colonize new sites or migrate in response to climate change. However, estimating seed dispersal is challenging in species that are secondarily dispersed by animals, and differences in disperser abundance or behavior could lead to large spatio-temporal variation in dispersal ability. Parentage and dispersal analyses combining genetic and ecological data provide accurate estimates of current dispersal, while spatial genetic structure (SGS) can shed light on past patterns of dispersal and establishment. Methodology and Principal Findings In this study, we estimate seed and pollen dispersal and parentage for two mixed-species red oak populations using a hierarchical Bayesian approach. We compare these results to those of a genetic ML parentage model. We also test whether observed patterns of SGS in three size cohorts are consistent with known site history and current dispersal patterns. We find that, while pollen dispersal is extensive at both sites, the scale of seed dispersal differs substantially. Parentage results differ between models due to additional data included in Bayesian model and differing genotyping error assumptions, but both indicate between-site dispersal differences. Patterns of SGS in large adults, small adults, and seedlings are consistent with known site history (farmed vs. selectively harvested), and with long-term differences in seed dispersal. This difference is consistent with predator/disperser satiation due to higher acorn production at the low-dispersal site. While this site-to-site variation results in substantial differences in asymptotic spread rates, dispersal for both sites is substantially lower than required to track latitudinal temperature shifts. Conclusions Animal-dispersed trees can exhibit considerable spatial variation in seed dispersal, although patterns may be surprisingly

  14. Santa Clara Valley water district multi-aquifer monitoring-well site, Coyote Creek Outdoor Classroom, San Jose, California

    USGS Publications Warehouse

    Hanson, R.T.; Newhouse, M.W.; Wentworth, C.M.; Williams, C.F.; Noce, T.E.; Bennett, M.J.

    2002-01-01

    The U.S. Geological Survey (USGS), in cooperation with the Santa Clara Valley Water District (SCVWD), has completed the first of several multiple-aquifer monitoring-well sites in the Santa Clara Valley. This site monitors ground-water levels and chemistry in the one of the major historic subsidence regions south of San Jose, California, at the Coyote Creek Outdoor Classroom (CCOC) (fig. 1) and provides additional basic information about the geology, hydrology, geochemistry, and subsidence potential of the upper- and lower-aquifer systems that is a major source of public water supply in the Santa Clara Valley. The site also serves as a science education exhibit at the outdoor classroom operated by SCVWD.

  15. Subsurface geology of a potential waste emplacement site, Salt Valley Anticline, Grand County, Utah

    USGS Publications Warehouse

    Hite, R.J.

    1977-01-01

    The Salt Valley anticline, which is located about 32 km northeast of Moab, Utah, is perhaps one of the most favorable waste emplacement sites in the Paradox basin. The site, which includes about 7.8 km 2, is highly accessible and is adjacent to a railroad. The anticline is one of a series of northwest-trending salt anticlines lying along the northeast edge of the Paradox basin. These anticlines are cored by evaporites of the Paradox Member of the Hermosa Formation of Middle Pennsylvanian age. The central core of the Salt Valley anticline forms a ridgelike mass of evaporites that has an estimated amplitude of 3,600 m. The evaporite core consists of about 87 percent halite rock, which includes some potash deposits; the remainder is black shale, silty dolomite, and anhydrite. The latter three lithologies are referred to as 'marker beds.' Using geophysical logs from drill holes on the anticline, it is possible to demonstrate that the marker beds are complexly folded and faulted. Available data concerning the geothermal gradient and heatflow at the site indicate that heat from emplaced wastes should be rapidly dissipated. Potentially exploitable resources of potash and petroleum are present at Salt Valley. Development of these resources may conflict with use of the site for waste emplacement.

  16. Dating Caral, a preceramic site in the Supe Valley on the central coast of Peru.

    PubMed

    Solis, R S; Haas, J; Creamer, W

    2001-04-27

    Radiocarbon dates from the site of Caral in the Supe Valley of Peru indicate that monumental corporate architecture, urban settlement, and irrigation agriculture began in the Americas by 4090 years before the present (2627 calibrated years B.C.) to 3640 years before the present (1977 calibrated years B.C.). Caral is located 23 kilometers inland from the Pacific coast and contains a central zone of monumental, residential, and nonresidential architecture covering an area of 65 hectares. Caral is one of 18 large preceramic sites in the Supe Valley.

  17. VALDRIFT 1.0: A valley atmospheric dispersion model with deposition

    DOE Office of Scientific and Technical Information (OSTI.GOV)

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

    1995-05-01

    VALDRIFT version 1.0 is an atmospheric transport and diffusion model for use in well-defined mountain valleys. It is designed to determine the extent of ddft from aedal pesticide spraying activities, but can also be applied to estimate the transport and diffusion of various air pollutants in valleys. The model is phenomenological -- that is, the dominant meteorological processes goveming the behavior of the valley atmosphere are formulated explicitly in the model, albeit in a highly parameterized fashion. The key meteorological processes treated are: (1) nonsteady and nonhomogeneous along-valley winds and turbulent diffusivities, (2) convective boundary layer growth, (3) inversion descent,more » (4) noctumal temperature inversion breakup, and (5) subsidence. The model is applicable under relatively cloud-free, undisturbed synoptic conditions and is configured to operate through one diumal cycle for a single valley. The inputs required are the valley topographical characteristics, pesticide release rate as a function of time and space, along-valley wind speed as a function of time and space, temperature inversion characteristics at sunrise, and sensible heat flux as a function of time following sunrise. Default values are provided for certain inputs in the absence of detailed observations. The outputs are three-dimensional air concentration and ground-level deposition fields as a function of time.« less

  18. NNSS Soils Monitoring: Plutonium Valley (CAU366) FY2012

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Miller, Julianne J.; Mizell, Steve A.; Nikolich, George

    2013-01-01

    The U.S. Department of Energy (DOE) National Nuclear Security Administration (NNSA), Nevada Site Office (NSO), Environmental Restoration Soils Activity has authorized the Desert Research Institute (DRI) to conduct field assessments of potential sediment transport of contaminated soil from Corrective Action Unit (CAU) 366, Area 11 Plutonium Valley Dispersion Sites Contamination Area (CA) during precipitation runoff events. Field measurements at the T-4 Atmospheric Test Site (CAU 370) suggest that radionuclide-contaminated soils may have migrated along a shallow ephemeral drainage that traverses the site (NNSA/NSO, 2009). (It is not entirely clear how contaminated soils got into their present location at the T-4more » Site, but flow to the channel has been redirected and the contamination does not appear to be migrating at present.) Aerial surveys in selected portions of the Nevada National Security Site (NNSS) also suggest that radionuclide-contaminated soils may be migrating along ephemeral channels in Areas 3, 8, 11, 18, and 25 (Colton, 1999). In Area 11, several low-level airborne surveys of the Plutonium Valley Dispersion Sites (CAU 366) show plumes of Americium 241 (Am-241) extending along ephemeral channels (Figure 1, marker numbers 5 and 6) below Corrective Action Site (CAS) 11-23-03 (marker number 3) and CAS 11 23-04 (marker number 4) (Colton, 1999). Plutonium Valley in Area 11 of the NNSS was selected for the study because of the aerial survey evidence suggesting downstream transport of radionuclide-contaminated soil. The aerial survey (Figure 1) shows a well defined finger of elevated radioactivity (marker number 5) extending to the southwest from the southernmost detonation site (marker number 4). This finger of contamination overlies a drainage channel mapped on the topographic base map used for presentation of the survey data suggesting surface runoff as a likely cause of the contaminated area. Additionally, instrumenting sites strongly suspected of

  19. Demonstration of Advanced Geophysics and Classification Methods on Munitions Response Sites - East Fork Valley Range Complex, Former Camp Hale

    DTIC Science & Technology

    2016-04-01

    with cores of igneous and metamorphic rocks flanked by steeply dipping sedimentary rocks . The valley floors range in elevation from about 9,310 to...Camp Hale, East Fork Valley Range Complex Munitions Response Site. This project is one in a series of projects funded by ESTCP to use advanced...Technology Certification Program ft Feet FUDS Formerly Used Defense Site GPS Global Positioning System ID Identification IMU Inertial Measurement Unit

  20. Elastic-wave propagation and site amplification in the Salt Lake Valley, Utah, from simulated normal faulting earthquakes

    USGS Publications Warehouse

    Benz, H.M.; Smith, R.B.

    1988-01-01

    The two-dimensional seismic response of the Salt Lake valley to near- and far-field earthquakes has been investigated from simulations of vertically incident plane waves and from normal-faulting earthquakes generated on the basin-bounding Wasatch fault. The plane-wave simulations were compared with observed site amplifications in the Salt Lake valley, based on seismic recordings from nuclear explosions in southern Nevada, that show 10 times greater amplification with the basin than measured values on hard-rock sites. Synthetic seismograms suggest that in the frequency band 0.3 to 1.5 Hz at least one-half the site amplitication can be attributed to the impedance contrast between the basin sediments and higher velocity basement rocks. -from Authors

  1. Archaeology Through Computational Linguistics: Inscription Statistics Predict Excavation Sites of Indus Valley Artifacts.

    PubMed

    Recchia, Gabriel L; Louwerse, Max M

    2016-11-01

    Computational techniques comparing co-occurrences of city names in texts allow the relative longitudes and latitudes of cities to be estimated algorithmically. However, these techniques have not been applied to estimate the provenance of artifacts with unknown origins. Here, we estimate the geographic origin of artifacts from the Indus Valley Civilization, applying methods commonly used in cognitive science to the Indus script. We show that these methods can accurately predict the relative locations of archeological sites on the basis of artifacts of known provenance, and we further apply these techniques to determine the most probable excavation sites of four sealings of unknown provenance. These findings suggest that inscription statistics reflect historical interactions among locations in the Indus Valley region, and they illustrate how computational methods can help localize inscribed archeological artifacts of unknown origin. The success of this method offers opportunities for the cognitive sciences in general and for computational anthropology specifically. Copyright © 2015 Cognitive Science Society, Inc.

  2. Nest-site fidelity and dispersal of Gyrfalcons estimated by noninvasive genetic sampling

    USGS Publications Warehouse

    Booms, T.L.; Talbot, S.L.; Sage, G.K.; McCaffery, B.J.; McCracken, K.G.; Schempf, P.F.

    2011-01-01

    We used feathers from adult Gyrfalcons (Falco rusticolus) molted in breeding territories and blood samples from nestlings to document nest-site fidelity and dispersal of breeding adults and juveniles at three areas 100- 350 km apart in Yukon Delta National Wildlife Refuge, Alaska, 2003-2007. We used genotypes from seven polymorphic microsatellite loci that provided a mean probability of identity of 0.91 ??10 -5. Breeding Gyrfalcons were highly faithful to study area and territory; we documented no dispersals of breeding birds among study areas and only one dispersal between territories. But their fidelity to nest sites was low; 22% of birds returned to the same nest site the following year. Distance among alternate nests within a territory averaged 750 m and was similar for both sexes. Mean tenure in a territory was 2.8 years, similar for both sexes, and distributed bimodally with peaks at 1 and 4 years. Mean annual turnover rate at the Ingakslugwat Hills (Volcanoes) study area was 20%. We detected three young that established breeding territories at distances ranging from 0 to 254 km from their natal territory, representing 2.5% apparent recruitment. Gyrfalcons in the Askinuk Mountains study area were slightly but statistically significantly differentiated genetically from those in the Volcanoes and Kilbuck Mountain study areas. These data are the first published on the nest-site fidelity, breeding dispersal, and natal dispersal of the Gyrfalcon in North America and demonstrate the utility of noninvasive genetic sampling to greatly improve our understanding of avian dispersal and its underlying mechanisms. ?? The Cooper Ornithological Society 2011.

  3. Cone penetration tests and soil borings at the Mason Road site in Green Valley, Solano County, California

    USGS Publications Warehouse

    Bennett, Michael J.; Noce, Thomas E.; Lienkaemper, James J.

    2011-01-01

    In support of a study to investigate the history of the Green Valley Fault, 13 cone penetration test soundings and 3 auger borings were made at the Mason Road site in Green Valley, Solano County, California. Three borings were made at or near two of the cone penetration test soundings. The soils are mostly clayey with a few sandy layers or lenses. Fine-grained soils range from low plasticity sandy lean clay to very plastic fat clay. Lack of stratigraphic correlation in the subsurface prevented us from determining whether any channels had been offset at this site. Because the soils are generally very clayey and few sand layers or lenses are loose, the liquefaction potential at the site is very low.

  4. Controls of Plume Dispersal at the Slow Spreading Mid-Atlantic Ridge

    NASA Astrophysics Data System (ADS)

    Walter, M.; Mertens, C.; Koehler, J.; Sueltenfuss, J.; Rhein, M.; Keir, R. S.; Schmale, O.; Schneider v. Deimling, J.; German, C. R.; Yoerger, D. R.; Baker, E. T.

    2011-12-01

    The slow-spreading Mid-Atlantic Ridges hosts a multitude of different types of hydrothermal systems. Here, we compare the fluxes and the plume dispersal at three high temperature sites located in very diverse settings at comparable depths (~3000m): The recently discovered sites Turtle Pits, and Nibelungen on the southern MAR, and the Logatchev field in the North Atlantic. Plume mapping for these sites on cruises between 2004 and 2009 consisted of CTD Towyo-, Yoyo,- and station work, including velocity profiling, as well as water sampling for analysis of trace gases (CH4, H2, 3He/4He) and metals; temperature measurements and fluid sampling at the vent sites were carried out with an ROV. The aim of this work is to gain a better understanding of how the setting of a vent site affects the dispersal of the particle plume, and what means can be used to infer possible locations of vent sites based on the hydrographic properties and plume observations, using high resolution bathymetric mapping and hydrographic information. The ultramafic-hosted Nibelungen site (8°18'S) consists of a single active smoking crater, along with several extinct smokers, which is located off-axis south of a non-transform offset. The setting is characterized by rugged topography, favorable for the generation of internal tides, internal wave breaking, and vertical mixing. Elevated mixing with turbulent diffusivities Kρ up to 0.1 m2 s-1, 3 to 4 orders of magnitude higher than open ocean values, was observed close to the vent site. The mixing as well as the flow field exhibited a strong tidal cycle; the plume dispersal is thus dominated by the fast and intermittent vertical exchange and characterized by small scale spatial and temporal variability. The Turtle Pits vent fields (4°48'S) are located on a sill in a north-south orientated rift valley. The site consists of three (known) high temperature fields: Turtle Pits, Comfortless Cove, and Red Lion. The particle plume is confined to the rift

  5. One year of tracer dispersion measurements over Washington, D.C.

    NASA Astrophysics Data System (ADS)

    Draxler, Roland R.

    Two perfluorocarbon tracers were released for 6 h from several locations about 20 km outside of Washington, D.C. at 36-h intervals for over 1 year. Continuous air samples were collected at 8-h intervals at one urban and two suburban sites, and at monthly intervals at 93 sites all over the region. Over 50 % of the 8-h samples showed no tracer concentration. However, about 20% of the samples had significant amounts of tracer, so that about 600 values under a variety of meteorological conditions are available for analysis. Although the Potomac River is only 100 m below the surrounding terrain, the tracer releases from within the river valley indicated that the tracer flow was channeled along the river valley. For tracer released away from the river valley, the tracer tended to pass aloft and not mix down into the river valley. Sequential concentration measurements frequently showed high values for extended periods after the tracer release terminated, decreasing exponentially with a half life of about 3 h. This suggests that the finite tracer plume may have a rather long upwind trailing edge toward the release point. The average rate of change in the vertical dispersion during summer and winter was found to be proportional to the 0.6 power of distance.

  6. West Valley Demonstration Project Annual Site Environmental Report Calendar Year 2011

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    none,

    2012-09-27

    The West Valley Demonstration Project (WVDP) Annual Site Environmental Report (ASER) for Calendar Year 2011. The report, prepared for the U.S. Department of Energy West Valley Demonstration Project office (DOE-WVDP), summarizes the environmental protection program at the WVDP for calendar year (CY) 2011. Monitoring and surveillance of the facilities used by the DOE are conducted to verify protection of public health and safety and the environment. The report is a key component of DOE’s effort to keep the public informed of environmental conditions at the WVDP. The quality assurance protocols applied to the environmental monitoring program ensure the validity andmore » accuracy of the monitoring data. In addition to demonstrating compliance with environmental laws, regulations, and directives, evaluation of data collected in 2011 continued to indicate that WVDP activities pose no threat to public health or safety, or to the environment.« less

  7. West Valley Demonstration Project Annual Site Environmental Report Calendar Year 2009

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    West Valley Environmental Services LLC

    2010-09-17

    The West Valley Demonstration Project (WVDP) Annual Site Environmental Report (ASER) for Calendar Year 2009. The report, prepared by the U.S. Department of Energy West Valley Demonstration Project office (DOE-WVDP), summarizes the environmental protection program at the WVDP for calendar year (CY) 2009. Monitoring and surveillance of the facilities used by the DOE are conducted to verify protection of public health and safety and the environment. The report is a key component of DOE’s effort to keep the public informed of environmental conditions at the WVDP. The quality assurance protocols applied to the environmental monitoring program by the DOE ensuremore » the validity and accuracy of the monitoring data. In addition to demonstrating compliance with environmental regulations and directives, evaluation of data collected in 2009 continued to indicate that WVDP activities pose no threat to public health or safety, or to the environment.« less

  8. West Valley Demonstration Project Annual Site Environmental Report Calendar Year 2013

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rendall, John D.; Steiner, Alison F.; Pendl, Michael P.

    2014-09-16

    West Valley Demonstration Project (WVDP) Annual Site Environmental Report (ASER) for Calendar Year 2013. The report, prepared for the U.S. Department of Energy West Valley Demonstration Project office (DOE-WVDP), summarizes the environmental protection program at the WVDP for calendar year (CY) 2013. Monitoring and surveillance of the facilities used by the DOE are conducted to verify protection of public health and safety and the environment. The report is a key component of DOE’s effort to keep the public informed of environmental conditions at the WVDP. The quality assurance protocols applied to the environmental monitoring program ensure the validity and accuracymore » of the monitoring data. In addition to demonstrating compliance with environmental laws, regulations, and directives, evaluation of data collected in 2013 continued to indicate that WVDP activities pose no threat to public health or safety, or to the environment.« less

  9. WEST VALLEY DEMONSTRATION PROJECT ANNUAL SITE ENVIRONMENTAL REPORT CALENDAR YEAR 2002

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    NONE

    2003-09-12

    This annual environmental monitoring report for the West Valley Demonstration Project (WVDP or Project) is published to inform those with interest about environmental conditions at the WVDP. In accordance with U.S. Department of Energy (DOE) Order 231.1, Environment, Safety, and Health Reporting, the report summarizes calendar year (CY) 2002 environmental monitoring data so as to describe the performance of the WVDP's environmental management system, confirm compliance with standards and regulations, and highlight important programs. In 2002, the West Valley Demonstration Project, the site of a DOE environmental cleanup activity operated by West Valley Nuclear Services Co. (WVNSCO), was in themore » final stages of stabilizing high-level radioactive waste (HLW) that remained at the site after commercial nuclear fuel reprocessing had been discontinued in the early 1970s. The Project is located in western New York State, about 30 miles south of Buffalo, within the New York State-owned Western New York Nuclear Service Center (WNYNSC). The WVDP is being conducted in cooperation with the New York State Energy Research and Development Authority (NYSERDA). Ongoing work activities at the WVDP during 2002 included: (1) completing HLW solidification and melter shutdown; (2) shipping low-level radioactive waste off-site for disposal; (3) constructing a facility where large high-activity components can be safely packaged for disposal; (4) packaging and removing spent materials from the vitrification facility; (5) preparing environmental impact statements for future activities; (6) removing as much of the waste left behind in waste tanks 8D-1 and 8D-2 as was reasonably possible; (7) removing storage racks, canisters, and debris from the fuel receiving and storage pool, decontaminating pool walls, and beginning shipment of debris for disposal; (8) ongoing decontamination in the general purpose cell and the process mechanical cell (also referred to as the head end cells); (9

  10. Seismic site characterization of an urban dedimentary basin, Livermore Valley, California: Site tesponse, basin-edge-induced surface waves, and 3D simulations

    USGS Publications Warehouse

    Hartzell, Stephen; Leeds, Alena L.; Ramirez-Guzman, Leonardo; Allen, James P.; Schmitt, Robert G.

    2016-01-01

    Thirty‐two accelerometers were deployed in the Livermore Valley, California, for approximately one year to study sedimentary basin effects. Many local and near‐regional earthquakes were recorded, including the 24 August 2014 Mw 6.0 Napa, California, earthquake. The resulting ground‐motion data set is used to quantify the seismic response of the Livermore basin, a major structural depression in the California Coast Range Province bounded by active faults. Site response is calculated by two methods: the reference‐site spectral ratio method and a source‐site spectral inversion method. Longer‐period (≥1  s) amplification factors follow the same general pattern as Bouguer gravity anomaly contours. Site response spectra are inverted for shallow shear‐wave velocity profiles, which are consistent with independent information. Frequency–wavenumber analysis is used to analyze plane‐wave propagation across the Livermore Valley and to identify basin‐edge‐induced surface waves with back azimuths different from the source back azimuth. Finite‐element simulations in a 3D velocity model of the region illustrate the generation of basin‐edge‐induced surface waves and point out strips of elevated ground velocities along the margins of the basin.

  11. The 1996-2009 borehole dilatometer installations, operation, and maintenance at sites in Long Valley Caldera, CA

    USGS Publications Warehouse

    Myren, Glenn; Johnston, Malcolm; Mueller, Robert

    2011-01-01

    High seismicity levels with accelerating uplift (under the resurgent dome) in Long Valley caldera in the eastern Sierra Nevada from 1989 to 1997, triggered upgrades to dilational strainmeters and other instrumentation installed in the early 1980's following a series of magnitude 6 earthquakes. This included two additional high-resolution borehole strainmeters and replacement of the failed strainmeter at Devil's Postpile. The purpose of the borehole-monitoring network is to monitor crustal deformation and other geophysical parameters associated with volcanic intrusions and earthquakes in the Long Valley Caldera. Additional instrumentation was added at these sites to improve the capability of providing continuous monitoring of the magma source under the resurgent dome. Sites were selected in regions of hard crystalline rock, where the expected signals from magmatic activity were calculated to be a maximum and the probability of an earthquake of magnitude 4 or greater is large. For the most part, the dilatometers were installed near existing arrays of surface tiltmeters, seismometers, level line, and GPS arrays. At each site, attempts are made to separate tectonic and volcanic signals from known noise sources in each instrument type. Each of these sites was planned to be a multi-parameter monitoring site, which included measurements of 3-component seismic velocity and acceleration, borehole strain, tilt, pore pressure and magnetic field. Using seismicity, geophysical knowledge, geologic and topographic maps, and geologists recommendations, lists of preliminary sites were chosen. Additional requirements were access, and telemetry constraints. When the final site choice was made, a permit was obtained from the U.S. Forest Service. Following this selection process, two new borehole sites were installed on the north and south side of the Long Valley Caldera in June of 1999. One site was located near Big Spring Campground to the east of Crestview. The second site was

  12. Local Population Structure and Patterns of Western Hemisphere Dispersal for Coccidioides spp., the Fungal Cause of Valley Fever.

    PubMed

    Engelthaler, David M; Roe, Chandler C; Hepp, Crystal M; Teixeira, Marcus; Driebe, Elizabeth M; Schupp, James M; Gade, Lalitha; Waddell, Victor; Komatsu, Kenneth; Arathoon, Eduardo; Logemann, Heidi; Thompson, George R; Chiller, Tom; Barker, Bridget; Keim, Paul; Litvintseva, Anastasia P

    2016-04-26

    Coccidioidomycosis (or valley fever) is a fungal disease with high morbidity and mortality that affects tens of thousands of people each year. This infection is caused by two sibling species, Coccidioides immitis and C. posadasii, which are endemic to specific arid locales throughout the Western Hemisphere, particularly the desert southwest of the United States. Recent epidemiological and population genetic data suggest that the geographic range of coccidioidomycosis is expanding, as new endemic clusters have been identified in the state of Washington, well outside the established endemic range. The genetic mechanisms and epidemiological consequences of this expansion are unknown and require better understanding of the population structure and evolutionary history of these pathogens. Here we performed multiple phylogenetic inference and population genomics analyses of 68 new and 18 previously published genomes. The results provide evidence of substantial population structure in C. posadasii and demonstrate the presence of distinct geographic clades in central and southern Arizona as well as dispersed populations in Texas, Mexico, South America, and Central America. Although a smaller number of C. immitis strains were included in the analyses, some evidence of phylogeographic structure was also detected in this species, which has been historically limited to California and Baja, Mexico. Bayesian analyses indicated that C. posadasii is the more ancient of the two species and that Arizona contains the most diverse subpopulations. We propose a southern Arizona-northern Mexico origin for C. posadasii and describe a pathway for dispersal and distribution out of this region. Coccidioidomycosis, or valley fever, is caused by the pathogenic fungi Coccidioides posadasii and C. immitis The fungal species and disease are primarily found in the American desert southwest, with spotted distribution throughout the Western Hemisphere. Initial molecular studies suggested a

  13. Water-quality assessment of the Rio Grande Valley, Colorado, New Mexico, and Texas; occurrence and distribution of selected pesticides and nutrients at selected surface-water sites in the Mesilla Valley, 1994-95

    USGS Publications Warehouse

    Healy, D.F.

    1996-01-01

    The Rio Grande Valley study unit of the U.S. Geological Survey National Water-Quality Assessment Program conducted a two-phase synoptic study of the occurrence and distribution of pesticides and nutrients in the surface water of the Mesilla Valley, New Mexico and Texas. Phase one, conducted in April-May 1994 during the high-flow irrigation season, consisted of a 6-week time- series sampling event during which 17 water-column samples were collected at 3 main-stem sites on the Rio Grande and a synoptic irrigation-run sampling event during which 19 water-column samples were collected at 7 main-stem sites, 10 drain sites, and 2 sites at the discharges of wastewater-treatment plants. Three samples are included in both the time-series and irrigation-run events. Phase two, conducted in January 1995 during the low-flow non-irrigation season, consisted of a non-irrigation synoptic sampling event during which 18 water-column samples were collected at seven main-stem sites, nine drain sites, and two sites at the discharges of wastewater-treatment plants and a bed- material sampling event during which 6 bed-material samples were collected at six sites near the mouths of drains that discharge to the Rio Grande. The 51 water-column samples were analyzed for 78 pesticides and metabolites and 8 nutrients along with other constituents. The six bed-material samples were analyzed for 21 pesticides and metabolites, gross polychlorinated biphenyls, and gross polychlorinated naphthalenes. The presence of dissolved pesticides in the surface water of the Mesilla Valley is erratic. A total of 100 detections of 17 different pesticides were detected in 44 of the water-column samples. As many as 38 percent of these detections may be attributed to pesticide use upstream from the valley or to nonagricultural pesticide use within the valley. There were 29 detections of 10 different pesticides in 17 samples during the irrigation run and 41 detections of 13 pesticides in 16 samples during the non

  14. MX Siting Investigation. Geotechnical Evaluation. Aggregate Resources Study, Lake Valley, Nevada.

    DTIC Science & Technology

    1981-02-27

    KILOMETERS Mx SITING INVESTIGATION IGURE IPARTMENT OF TNt Ag1 FORCE - GMO 2 -_ONiO NATIONAL INC. FlU It FN-TR-37-f 5 2. Aerial and ground reconnaissance...fine, or crushed rock) and potential construction use ( con - crete and/or road base). TOM. FN-TR -37-f 6 2.0 STUDY APPROACH 2.1 EXISTING DATA Collection...2 the southwestern part of Lake Valley. This formation also pro - vides Class I crushed rock aggregate material in the southern White Rock Mountains

  15. Qualitative aspects of the effectiveness of Culpeo foxes (Lycalopex culpaeus) as dispersers of Prosopis alba (Fabaceae) in a Bolivian dry valley

    NASA Astrophysics Data System (ADS)

    Maldonado, D. E.; Loayza, A. P.; Garcia, E.; Pacheco, L. F.

    2018-02-01

    Foxes disperse several plant species in arid and semi-arid environments, but their effectiveness as dispersal agents still remains unclear. In this study, we examined qualitative components of the effectiveness of L. culpaeus as a disperser of P. alba seeds in an inter-Andean dry valley of La Paz, Bolivia. Specifically, we determined seed deposition microhabitats, and the probabilities of germination, seed removal and seedling recruitment in these microhabitats. Additionally, we assessed the effect of gut-passage on P. alba germination. We collected 159 scats, which contained a total of 3402 endocarps fragments. Foxes dispersed seeds into two microhabitats: open areas and under woody vegetation, but more frequently in the former. The probability of germination did not differ between gut-passed and control seeds, but control seeds germinated faster than gut-passed ones. The likelihood of removal was greater for endocarps fragments in open microhabitats than under woody vegetation. Only a small percentage of the seeds in each microhabitat germinated, but none survived more than a week. We conclude that although the Culpeo fox can defecate intact P. alba seeds, it does not provide effective dispersal services.

  16. MX Siting Investigation. Gravity Survey - Sevier Desert Valley, Utah.

    DTIC Science & Technology

    1981-01-24

    Cheyenne, Wyoming. DMAHTC reduces the data to Simple Bouguer Anomaly (see Section A1.4, Appendix Al.0). The Defense Mapping Agency Aerospace Center...Desert Valley, Utah ......... 2 2 Topographic Setting - Sevier Desert Valley, Utah . 3 LIST OF DRAWINGS Drawing Number 1 Complete Bouguer Anomaly...gravity stations were distributed throughout the valley at an approxi- mate interval of 1.4 miles (2.3 km). Drawing 1 is a Complete Bouguer Anomaly

  17. West Valley Demonstration Project Annual Site Environmental Report (ASER) Calendar Year (2016)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Steiner, Alison F.; Pendl, Michael P.; Steiner, II, Robert E.

    West Valley Demonstration Project (WVDP) Annual Site Environmental Report (ASER) for Calendar Year 2016. The report, prepared for the U.S. Department of Energy West Valley Demonstration Project office (DOE-WVDP), summarizes the environmental protection program at the WVDP for calendar year (CY) 2016. Monitoring and surveillance of the facilities used by the DOE are conducted to verify protection of public health and safety and the environment. The report is a key component of DOE’s effort to keep the public informed of environmental conditions at the WVDP. The quality assurance protocols applied to the environmental monitoring program ensure the validity and accuracymore » of the monitoring data. In addition to demonstrating compliance with environmental laws, regulations, and directives, evaluation of data collected in 2016 continued to indicate that WVDP activities pose no threat to public health or safety, or to the environment.« less

  18. Valley polarization in bismuth

    NASA Astrophysics Data System (ADS)

    Fauque, Benoit

    2013-03-01

    The electronic structure of certain crystal lattices can contain multiple degenerate valleys for their charge carriers to occupy. The principal challenge in the development of valleytronics is to lift the valley degeneracy of charge carriers in a controlled way. In bulk semi-metallic bismuth, the Fermi surface includes three cigar-shaped electron valleys lying almost perpendicular to the high symmetry axis known as the trigonal axis. The in-plane mass anisotropy of each valley exceeds 200 as a consequence of Dirac dispersion, which drastically reduces the effective mass along two out of the three orientations. According to our recent study of angle-dependent magnetoresistance in bismuth, a flow of Dirac electrons along the trigonal axis is extremely sensitive to the orientation of in-plane magnetic field. Thus, a rotatable magnetic field can be used as a valley valve to tune the contribution of each valley to the total conductivity. As a consequence of a unique combination of high mobility and extreme mass anisotropy in bismuth, the effect is visible even at room temperature in a magnetic field of 1 T. Thus, a modest magnetic field can be used as a valley valve in bismuth. The results of our recent investigation of angle-dependent magnetoresistance in other semi-metals and doped semiconductors suggest that a rotating magnetic field can behave as a valley valve in a multi-valley system with sizeable mass anisotropy.

  19. Coastal, valley, and oasis interaction: impact on the evolution of ancient populations in the South Central Andes.

    PubMed

    Varela, Héctor H; Cocilovo, Jose A; Fuchs, María L; O'Brien, Tyler G

    2014-12-01

    The existing biocultural links are analyzed among ancient inhabitants of the Cochabamba valleys (Bolivia) from the Formative and Tiwanaku periods, coastal and inland Azapa region (Chile) from the Late Archaic to the Late periods, and the Atacama Desert oases (Chile) from the Formative period to the time of European contact. Craniometric information obtained from a sample of 565 individuals from different sites of the studied regions was evaluated using methods derived from quantitative genetics and multivariate statistical analysis techniques. It is shown that during the Formative and Tiwanaku periods inhabitants of the Cochabamba valleys maintained contact with the population of northern Chile. This contact was more fluid with the people from the interior valley of Azapa than it was with the settlers of San Pedro Atacama (SPA). An important biological affinity in the Late Period between the inhabitants of the Azapa valley and the late SPA groups is also examined. The Late-Inca Catarpe SPA sample shows a broad genetic variability shared with the majority of the groups studied. The results reaffirm the differences between the coastal and interior Azapa valley groups and strengthen the hypothesis of two pathways to populating the south central Andean area. The divergence observed among subpopulations can be explained by the spatiotemporal dispersion between them, genetic drift dispersion compensated by the action of gene flow, and cultural norms that regulate within group mating. © 2014 Wiley Periodicals, Inc.

  20. Between-Site Differences in the Scale of Dispersal and Gene Flow in Red Oak

    Treesearch

    Emily V Moran; James S. Clark

    2012-01-01

    Background: Nut-bearing trees, including oaks (Quercus spp.), are considered to be highly dispersal limited, leading to concerns about their ability to colonize new sites or migrate in response to climate change. However, estimating seed dispersal is challenging in species that are secondarily dispersed by animals, and differences in...

  1. Hydrological responses to channelization and the formation of valley plugs and shoals

    USGS Publications Warehouse

    Pierce, Aaron R.; King, Sammy L.

    2017-01-01

    Rehabilitation of floodplain systems focuses on restoring interactions between the fluvial system and floodplain, however, there is a paucity of information on the effects of valley plugs and shoals on floodplain hydrological processes. We investigated hydrologic regimes in floodplains at three valley plug sites, two shoal sites, and three unchannelized sites. Valley plug sites had altered surface and sub-surface hydrology relative to unchannelized sites, while only sub-surface hydrology was affected at shoal sites. Some of the changes were unexpected, such as reduced flood duration and flood depth in floodplains associated with valley plugs. Our results emphasize the variability associated with hydrologic processes around valley plugs and our rudimentary understanding of the effects associated with these geomorphic features. Water table levels were lower at valley plug sites compared to unchannelized sites, however, valley plug sites had a greater proportion of days when water table inundation was above mean root collar depth than both shoal and unchannelized sites as a result of lower root collar depths and higher deposition rates. This study has provided evidence that valley plugs can affect both surface and sub-surface hydrology in different ways than previously thought and illustrates the variability in hydrological responses to valley plug formation.

  2. Dispersal of emerald ash borer at outlier sites: three case studies

    Treesearch

    Deborah G. McCullough; Nathan W. Siegert; Therese M. Poland; David L. Cappaert; Ivich Fraser; David Williams

    2005-01-01

    We worked with cooperators from several state and federal agencies in 2003 and 2004 to assess dispersal of emerald ash borer (EAB), Agrilus planipennis Fairmaire, from known source points in three outlier sites. In February 2003, we felled and sampled more than 200 ash trees at an outlier site near Tipton, Michigan, where one generation of adult...

  3. West Valley Demonstration Project Annual Site Environmental Report (ASER) for Calendar Year 2014

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rendall, John D.; Steiner, Alison F.; Pendl, Michael P.

    West Valley Demonstration Project (WVDP) Annual Site Environmental Report (ASER) for Calendar Year 2014. The report, prepared for the U.S. Department of Energy West Valley Demonstration Project office (DOE-WVDP), summarizes the environmental protection program at the WVDP for calendar year (CY) 2014. Monitoring and surveillance of the facilities used by the DOE are conducted to verify protection of public health and safety and the environment. The report is a key component of DOE’s effort to keep the public informed of environmental conditions at the WVDP. The quality assurance protocols applied to the environmental monitoring program ensure the validity and accuracymore » of the monitoring data. In addition to demonstrating compliance with environmental laws, regulations, and directives, evaluation of data collected in 2014 continued to indicate that WVDP activities pose no threat to public health or safety, or to the environment.« less

  4. West Valley Demonstration Project Annual Site Environmental Report (ASER) for Calendar Year 2015

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rendall, John D.; Steiner, Alison F.; Pendl, Michael P.

    West Valley Demonstration Project (WVDP) Annual Site Environmental Report (ASER) for Calendar Year 2015. The report, prepared for the U.S. Department of Energy West Valley Demonstration Project office (DOE-WVDP), summarizes the environmental protection program at the WVDP for calendar year (CY) 2015. Monitoring and surveillance of the facilities used by the DOE are conducted to verify protection of public health and safety and the environment. The report is a key component of DOE’s effort to keep the public informed of environmental conditions at the WVDP. The quality assurance protocols applied to the environmental monitoring program ensure the validity and accuracymore » of the monitoring data. In addition to demonstrating compliance with environmental laws, regulations, and directives, evaluation of data collected in 2015 continued to indicate that WVDP activities pose no threat to public health or safety, or to the environment.« less

  5. Aquatic habitats of Canaan Valley, West Virginia: Diversity and environmental threats

    USGS Publications Warehouse

    Snyder, C.D.; Young, J.A.; Stout, B. M.

    2006-01-01

    We conducted surveys of aquatic habitats during the spring and summer of 1995 in Canaan Valley, WV, to describe the diversity of aquatic habitats in the valley and identify issues that may threaten the viability of aquatic species. We assessed physical habitat and water chemistry of 126 ponds and 82 stream sites, and related habitat characteristics to landscape variables such as geology and terrain. Based on our analyses, we found two issues likely to affect the viability of aquatic populations in the valley. The first issue was acid rain and the extent to which it potentially limits the distribution of aquatic and semi-aquatic species, particularly in headwater portions of the watershed. We estimate that nearly 46%, or 56 kilometers of stream, had pH levels that would not support survival and reproduction of Salvelinuw fontinalis (brook trout), one of the most acid-tolerant fishes in the eastern US. The second issue was the influence of Castor canadensis (beaver) activity. In the Canaan Valley State Park portion of the valley, beaver have transformed 4.7 kilometers of stream (approximately 17% of the total) to pond habitat through their dam building. This has resulted in an increase in pond habitat, a decrease in stream habitat, and a fragmented stream network (i.e., beaver ponds dispersed among stream reaches). In addition, beaver have eliminated an undetermined amount of forested riparian area through their foraging activities. Depending on the perspective, beaver-mediated changes can be viewed as positive or negative. Increases in pond habitat may increase habitat heterogeneity with consequent increases in biological diversity. In contrast, flooding associated with beaver activity may eliminate lowland wetlands and associated species, create barriers to fish dispersal, and possibly contribute to low dissolved oxygen levels in the Blackwater River. We recommend that future management strategies for the wildlife refuge be viewed in the context of these two issues

  6. Hydrogeology and simulation of groundwater flow at the Green Valley reclaimed coal refuse site near Terre Haute, Indiana

    USGS Publications Warehouse

    Bayless, E. Randall; Arihood, Leslie D.; Fowler, Kathleen K.

    2011-01-01

    The Green Valley reclaimed coal refuse site, near Terre Haute, Ind., was mined for coal from 1948 to 1963. Subsurface coal was cleaned and sorted at land surface, and waste material was deposited over the native glacial till. Approximately 2.7 million cubic yards of waste was deposited over 159 acres (92.3 hectares) in tailings ponds and gob piles. During 1993, the Indiana Department of Natural Resources, Division of Reclamation, improved the site by grading gob piles, filling tailings ponds, and covering the refuse with a layer of glacial drift. During 2008, the Division of Reclamation and U.S. Geological Survey initiated a cooperative investigation to characterize the hydrogeology of the site and construct a calibrated groundwater flow model that could be used to simulate the results of future remedial actions. In support of the modeling, a data-collection network was installed at the Green Valley site to measure weather components, geophysical properties, groundwater levels, and stream and seep flow. Results of the investigation indicate that (1) there is negligible overland flow from the site, (2) the prevailing groundwater-flow direction is from northeast to southwest, with a much smaller drainage to the northeast, (3) there is not a direct hydraulic connection between the refuse and West Little Sugar Creek, (4) about 24 percent of the groundwater recharge emerges through seeps, and water from the seeps evaporates or eventually flows to West Little Sugar Creek and the Green Valley Mine Pond, and (5) about 72 percent of groundwater recharge moves vertically downward from the coal refuse into the till and follows long, slow flow paths to eventual dischage points.

  7. Roseate Tern breeding dispersal and fidelity: Responses to two newly restored colony sites

    USGS Publications Warehouse

    Spendelow, Jeffrey A.; Monticelli, David; Nichols, James D.; Hines, James; Nisbet, Ian; Cormons, Grace; Hays, Helen; Hatch, Jeremy; Mostello, Carolyn

    2016-01-01

    We used 22 yr of capture–mark–reencounter (CMR) data collected from 1988 to 2009 on about 12,500 birds at what went from three to five coastal colony sites in Massachusetts, New York, and Connecticut, United States, to examine spatial and temporal variation in breeding dispersal/fidelity rates of adult Roseate Terns (Sterna dougallii). At the start of our study, Roseate Terns nested at only one site (Bird Island) in Buzzards Bay, Massachusetts, but two more sites in this bay (Ram and Penikese Islands) were subsequently recolonized and became incorporated into our CMR metapopulation study. We examined four major hypotheses about factors we thought might influence colony-site fidelity and movement rates in the restructured system. We found some evidence that colony-site fidelity remained higher at long-established sites compared with newer ones and that breeding dispersal was more likely to occur among nearby sites than distant ones. Sustained predation at Falkner Island, Connecticut, did not result in a sustained drop in fidelity rates of breeders. Patterns of breeding dispersal differed substantially at the two restored sites. The fidelity of Roseate Terns at Bird dropped quickly after nearby Ram was recolonized in 1994, and fidelity rates for Ram soon approached those for Bird. After an oil spill in Buzzards Bay in April 2003, hazing (deliberate disturbance) of the terns at Ram prior to the start of egg-laying resulted in lowering of fidelity at this site, a decrease in immigration from Bird, and recolonization of Penikese by Roseate Terns. Annual fidelity rates at Penikese increased somewhat several years after the initial recolonization, but they remained much lower there than at all the other sites throughout the study period. The sustained high annual rates of emigration from Penikese resulted in the eventual failure of the restoration effort there, and in 2013, no Roseate Terns nested at this site.

  8. Soils, surficial geology, and geomorphology of the Bear Creek Valley Low-Level Waste Disposal Development and Demonstration Program site

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lietzke, D.A.; Lee, S.Y.; Lambert, R.E.

    1988-04-01

    An intensive soil survey was conducted on the proposed Low-Level Waste Disposal Development and Demonstration Program site (LLWDDD) in Bear Creek Valley. Soils on the site were related to the underlying residuum and to the surficial colluvium and alluvium. Within any particular geologic formation, soils were subdivided based mostly on the degree of weathering, as reflected by saprolite weathering and morphologic features of the soils. Degree of weathering was related both to slope shape and gradient and to the joint-fracture system. Erosion classes were also used to make further subdivisions of any particular soil. Deep pits were dug in eachmore » of the major Conasauga Group formations (Pumpkin Valley, Rogersville, Maryville, and Nolichucky) for soil and saprolite characterization. Because of the widespread presence of alluvium and colluvium, which are potential sources of fill and final cover material, pits and trenches were dug to characterize the properties of these soils and to try to understand the past geomorphic history of the site. The results of the soil survey investigation indicated that the deeply weathered Pumpkin Valley residuum has good potential for the construction of tumuli or other types of belowground or aboveground burial of prepackaged compacted waste. 11 refs., 30 figs., 3 tabs.« less

  9. Hazardous Waste Cleanup: West Valley Demonstration Project USDOE in West Valley, New York

    EPA Pesticide Factsheets

    The U.S. Department of Energy's West Valley Demonstration Project is located at 10282 Rock Spring Road in West Valley, New York. This is a 167 acre, Department of Energy (DOE)-operated portion of a 3,300-acre site owned by the New York State Energy

  10. Seismic Wave Amplification in Las Vegas: Site Characterization Measurements and Response Models

    NASA Astrophysics Data System (ADS)

    Louie, J. N.; Anderson, J. G.; Luke, B.; Snelson, C.; Taylor, W.; Rodgers, A.; McCallen, D.; Tkalcic, H.; Wagoner, J.

    2004-12-01

    As part of a multidisciplinary effort to understand seismic wave amplification in Las Vegas Valley, we conducted geotechnical and seismic refraction field studies, geologic and lithologic interpretation, and geophysical model building. Frequency-dependent amplifications (site response) and peak ground motions strongly correlate with site conditions as characterized by the models. The models include basin depths and velocities, which also correlate against ground motions. Preliminary geologic models were constructed from detailed geologic and fault mapping, logs of over 500 wells penetrating greater than 200 m depth, gravity-inversion results from the USGS, and USDA soil maps. Valley-wide refraction studies we conducted in 2002 and 2003 were inverted for constraints on basin geometry, and deep basin and basement P velocities with some 3-d control to depths of 5 km. Surface-wave studies during 2002-2004 characterized more than 75 sites within the Valley for shear velocity to depths exceeding 100 m, including all the legacy sites where nuclear-blast ground motions were recorded. The SASW and refraction-microtremor surface-surveying techniques proved to provide complementary, and coordinating Rayleigh dispersion-curve data at a dozen sites. Borehole geotechnical studies at a half-dozen sites confirmed the shear-velocity profiles that we derived from surface-wave studies. We then correlated all the geotechnical data against a detailed stratigraphic model, derived from drilling logs, to create a Valley-wide model for shallow site conditions. This well-log-based model predicts site measurements better than do models based solely on geologic or soil mapping.

  11. Bottomland hardwood establishment and avian colonization of reforested sites in the Mississippi Alluvial Valley

    USGS Publications Warehouse

    Wilson, R.R.; Twedt, D.J.; Fredrickson, L.H.; King, S.L.; Kaminski, R.M.

    2005-01-01

    Reforestation of bottomland hardwood sites in the Mississippi Alluvial Valley has markedly increased in recent years, primarily due to financial incentive programs such as the Wetland Reserve Program, Partners for Wildlife Program, and state and private conservation programs. An avian conservation plan for the Mississippi Alluvial Valley proposes returning a substantial area of cropland to forested wetlands. Understanding how birds colonize reforested sites is important to assess the effectiveness of avian conservation. We evaluated establishment of woody species and assessed bird colonization on 89 reforested sites. These reforested sites were primarily planted with heavy-seeded oaks (Quercus spp.) and pecans (Carya illinoensis). Natural invasion of light-seeded species was expected to diversify these forests for wildlife and sustainable timber harvest. Planted tree species averaged 397 + 36 stems/ha-1, whereas naturally invading trees averaged 1675 + 241 stems/ha. However, naturally invading trees were shorter than planted trees and most natural invasion occurred <100 m from an existing forested edge. Even so, planted trees were relatively slow to develop vertical structure, especially when compared with tree species planted and managed for pulpwood production. Slow development of vertical structure resulted in grassland bird species, particularly dickcissel (Spiza americana) and red-winged blackbird (Agelaius phoeniceus), being the dominant avian colonizers for the first 7 years post-planting. High priority bird species (as defined by Partners in Flight), such as prothonotary warbler (Protonotaria citrea) and wood thrush (Hylocichla mustelina), were not frequently detected until stands were 15 years old. Canonical correspondence analysis revealed tree height had the greatest influence on the bird communities colonizing reforested sites. Because colonization by forest birds is dependent on tree height, we recommend inclusion of at least one fast-growing tree

  12. Estimation by capture-recapture of recruitment and dispersal over several sites

    USGS Publications Warehouse

    Lebreton, J.D.; Hines, J.E.; Pradel, R.; Nichols, J.D.; Spendelow, J.A.

    2003-01-01

    Dispersal in animal populations is intimately linked with accession to reproduction, i.e. recruitment, and population regulation. Dispersal processes are thus a key component of population dynamics to the same extent as reproduction or mortality processes. Despite the growing interest in spatial aspects of population dynamics, the methodology for estimating dispersal, in particular in relation with recruitment, is limited. In many animal populations, in particular vertebrates, the impossibility of following individuals over space and time in an exhaustive way leads to the need to frame the estimation of dispersal in the context of capture-recapture methodology. We present here a class of age-dependent multistate capture-recapture models for the simultaneous estimation of natal dispersal, breeding dispersal, and age-dependent recruitment. These models are suitable for populations in which individuals are marked at birth and then recaptured over several sites. Under simple constraints, they can be used in populations where non-breeders are not observed, as is often the case with colonial waterbirds monitored on their breeding grounds. Biological questions can be addressed by comparing models differing in structure, according to the generalized linear model philosophy broadly used in capture-recapture methodology. We illustrate the potential of this approach by an analysis of recruitment and dispersal in the roseate tern Sterna dougallii.

  13. VEGETATION CHARACTERIZATION OF THREE CONTRASTING RIPARIAN SITES, WILLAMETTE VALLEY, OR

    EPA Science Inventory

    Much of the native riparian vegetation of the Willamette Valley, Oregon, has been replaced with agricultural crops or invasive non-native plant species. Detailed information about current Willamette Valley riparian vegetation is generally lacking. Plant species composition data...

  14. Valley floor climate observations from the McMurdo dry valleys, Antarctica, 1986-2000

    USGS Publications Warehouse

    Doran, P.T.; McKay, C.P.; Clow, G.D.; Dana, G.L.; Fountain, A.G.; Nylen, T.; Lyons, W.B.

    2002-01-01

    Climate observations from the McMurdo dry valleys, East Antarctica are presented from a network of seven valley floor automatic meteorological stations during the period 1986 to 2000. Mean annual temperatures ranged from -14.8??C to -30.0??C, depending on the site and period of measurement. Mean annual relative humidity is generally highest near the coast. Mean annual wind speed increases with proximity to the polar plateau. Site-to-site variation in mean annual solar flux and PAR is due to exposure of each station and changes over time are likely related to changes in cloudiness. During the nonsummer months, strong katabatic winds are frequent at some sites and infrequent at others, creating large variation in mean annual temperature owing to the warming effect of the winds. Katabatic wind exposure appears to be controlled to a large degree by the presence of colder air in the region that collects at low points and keeps the warm less dense katabatic flow from the ground. The strong influence of katabatic winds makes prediction of relative mean annual temperature based on geographical position (elevation and distance from the coast) alone, not possible. During the summer months, onshore winds dominate and warm as they progress through the valleys creating a strong linear relationship (r2 = 0.992) of increasing potential temperature with distance from the coast (0.09??C km-1). In contrast to mean annual temperature, summer temperature lends itself quite well to model predictions, and is used to construct a statistical model for predicting summer dry valley temperatures at unmonitored sites. Copyright 2002 by the American Geophysical Union.

  15. Comparing regeneration techniques for afforesting previously farmed bottomland hardwood sites in the Lower Mississippi Alluvial Valley, USA

    Treesearch

    Brian Roy Lockhart; Bob Keeland; John McCoy; Thomas J. Dean

    2003-01-01

    A study was implemented to test site preparation methods and artificial regeneration of three oak (Quercus spp.) species on four agricultural fields in the Lower Mississippi Alluvial Valley in Louisiana, USA. Six years after establishment, few consistent differences were found in oak density between sowing acorn methods (seed drill versus broadcast...

  16. 77 FR 63873 - Johnson Controls, Inc. Including On-Site Leased Workers of Valley Staffing and AZ Quality Hudson...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-17

    ... workers of Johnson Controls, Inc., including on-site leased workers from Valley Staffing, Hudson..., Wisconsin location of Johnson Controls, Inc. The Department has determined that these workers were sufficiently under the control of the subject firm to be considered leased workers. Based on these findings...

  17. MX Siting Investigation. Gravity Survey - Big Smokey Valley, Nevada.

    DTIC Science & Technology

    1980-11-28

    Monte Cristo Range, on the south by Lone Mountain arid Tonopah, Nevada, and on the north by the T1i7 ,abhv i a7e. True area covered by this report lies...Royston Hills and Monte Cristo Range) are chiefly Tertiary tuffs, rhyolites, andesites, and basalts. Basin-fill deposits within the valley reach combined...east of Royston Hills and Monte Cristo Range. At the southern end where the valley bifurcates, faults are interpreted to be near both flanks of Lone

  18. Hydrologic effects of stress-relief fracturing in an Appalachian Valley

    USGS Publications Warehouse

    Wyrick, Granville G.; Borchers, James W.

    1981-01-01

    A hydrologic study at Twin Falls State Park, Wyoming County, West Virginia, was made to determine how fracture systems affect the occurrence and movement of ground water in a typical valley of the Appalachian Plateaus Physiographic Province. Twin Falls was selected because it is generally unaffected by factors that would complicate an analysis of the data. The study area was the Black Fork Valley at Twin Falls. The valley is about 3 miles long and 400 to 600 feet wide and is cut into massive sandstone units interbedded with thin coal and shale beds. The study was made to determine how aquifer characteristics were related to fracture systems in this valley, so that the relation could be applied to studies of other valleys. Two sites were selected for test drilling, pumping tests, and geophysical studies. One site is in the upper part of the valley, and the second is near the lower central part. At both sites, ground water occurs mainly in horizontal bedding-plane fractures under the valley floor and in nearly vertical and horizontal slump fractures along the valley wall. The aquifer is under confined conditions under the valley floor and unconfined conditions along the valley wall. The fractures pinch out under the valley walls, which form impermeable barriers. Tests of wells near the valley center indicated a change in storage coefficient as the cone of depression caused by pumping reached the confined-unconfined boundaries; the tests also indicated barrier-image effects when the cone reached the impermeable boundaries. Drawdown from pumping near the center of the valley affected water levels at both sites, indicating a hydraulic connection from the upper to the lower end of the valley. Stream gain-and-loss studies show that ground water discharges to the stream from horizontal fractures beneath Black Fork Falls, near the mouth of Black Fork. The fracture systems that constitute most of the transmissive part of the aquifer at Twin Falls are like those described as

  19. The dating and interpretation of a Mode 1 site in the Luangwa Valley, Zambia.

    PubMed

    Barham, Lawrence; Phillips, William M; Maher, Barbara A; Karloukovski, Vassil; Duller, Geoff A T; Jain, Mayank; Wintle, Ann G

    2011-05-01

    Flake based assemblages (Mode 1) comprise the earliest stone technologies known, with well-dated Oldowan sites occurring in eastern Africa between ~2.6-1.7 Ma, and in less securely dated contexts in central, southern and northern Africa. Our understanding of the spread and local development of this technology outside East Africa remains hampered by the lack of reliable numerical dating techniques applicable to non-volcanic deposits. This study applied the still relatively new technique of cosmogenic nuclide burial dating ((10)Be/(26)Al) to calculate burial ages for fluvial gravels containing Mode 1 artefacts in the Luangwa Valley, Zambia. The Manzi River, a tributary of the Luangwa River, has exposed a 4.7 m deep section of fluvial sands with discontinuous but stratified gravel layers bearing Mode 1, possibly Oldowan, artefacts in the basal layers. An unconformity divides the Manzi section, separating Mode 1 deposits from overlying gravels containing Mode 3 (Middle Stone Age) artefacts. No diagnostic Mode 2 (Acheulean) artefacts were found. Cosmogenic nuclide burial dating was attempted for the basal gravels as well as exposure ages for the upper Mode 3 gravels, but was unsuccessful. The complex depositional history of the site prevented the calculation of reliable age models. A relative chronology for the full Manzi sequence was constructed, however, from the magnetostratigraphy of the deposit (N>R>N sequence). Isothermal thermoluminescence (ITL) dating of the upper Mode 3 layers also provided consistent results (~78 ka). A coarse but chronologically coherent sequence now exists for the Manzi section with the unconformity separating probable mid- or early Pleistocene deposits below from late Pleistocene deposits above. The results suggest Mode 1 technology in the Luangwa Valley may post-date the Oldowan in eastern and southern Africa. The dating programme has contributed to a clearer understanding of the geomorphological processes that have shaped the valley and

  20. The dating and interpretation of a Mode 1 site in the Luangwa Valley, Zambia

    USGS Publications Warehouse

    Barham, L.; Phillips, W.M.; Maher, B.A.; Karloukovski, V.; Duller, G.A.T.; Jain, M.; Wintle, A.G.

    2011-01-01

    Flake based assemblages (Mode 1) comprise the earliest stone technologies known, with well-dated Oldowan sites occurring in eastern Africa between ??? 2.6-1.7 Ma, and in less securely dated contexts in central, southern and northern Africa. Our understanding of the spread and local development of this technology outside East Africa remains hampered by the lack of reliable numerical dating techniques applicable to non-volcanic deposits. This study applied the still relatively new technique of cosmogenic nuclide burial dating (10Be/26Al) to calculate burial ages for fluvial gravels containing Mode 1 artefacts in the Luangwa Valley, Zambia. The Manzi River, a tributary of the Luangwa River, has exposed a 4.7 m deep section of fluvial sands with discontinuous but stratified gravel layers bearing Mode 1, possibly Oldowan, artefacts in the basal layers. An unconformity divides the Manzi section, separating Mode 1 deposits from overlying gravels containing Mode 3 (Middle Stone Age) artefacts. No diagnostic Mode 2 (Acheulean) artefacts were found. Cosmogenic nuclide burial dating was attempted for the basal gravels as well as exposure ages for the upper Mode 3 gravels, but was unsuccessful. The complex depositional history of the site prevented the calculation of reliable age models. A relative chronology for the full Manzi sequence was constructed, however, from the magnetostratigraphy of the deposit (N>R>N sequence). Isothermal thermoluminescence (ITL) dating of the upper Mode 3 layers also provided consistent results (???78 ka). A coarse but chronologically coherent sequence now exists for the Manzi section with the unconformity separating probable mid- or early Pleistocene deposits below from late Pleistocene deposits above. The results suggest Mode 1 technology in the Luangwa Valley may post-date the Oldowan in eastern and southern Africa. The dating programme has contributed to a clearer understanding of the geomorphological processes that have shaped the valley and

  1. Seismic velocity site characterization of 10 Arizona strong-motion recording stations by spectral analysis of surface wave dispersion

    USGS Publications Warehouse

    Kayen, Robert E.; Carkin, Brad A.; Corbett, Skye C.

    2017-10-19

    Vertical one-dimensional shear wave velocity (VS) profiles are presented for strong-motion sites in Arizona for a suite of stations surrounding the Palo Verde Nuclear Generating Station. The purpose of the study is to determine the detailed site velocity profile, the average velocity in the upper 30 meters of the profile (VS30), the average velocity for the entire profile (VSZ), and the National Earthquake Hazards Reduction Program (NEHRP) site classification. The VS profiles are estimated using a non-invasive continuous-sine-wave method for gathering the dispersion characteristics of surface waves. Shear wave velocity profiles were inverted from the averaged dispersion curves using three independent methods for comparison, and the root-mean-square combined coefficient of variation (COV) of the dispersion and inversion calculations are estimated for each site.

  2. Early Holocene pecan, Carya illinoensis, in the Mississippi River Valley near Muscatine, Iowa

    USGS Publications Warehouse

    Bettis, E. Arthur; Baker, R.G.; Nations, B.K.; Benn, D.W.

    1990-01-01

    A fossil pecan, Carya illinoensis (Wang.) K. Koch, from floodplain sediments of the Mississippi River near Muscatine, Iowa, was accelerator-dated at 7280 ?? 120 yr B.P. This discovery indicates that pecan was at or near its present northern limit by that time. Carya pollen profiles from the Mississippi River Trench indicate that hickory pollen percentages were much higher in the valley than at upland locations during the early Holocene. Pecan, the hickory with the most restricted riparian habitat, is the likely candidate for producing these peaks in Carya pollen percentages. Therefore, pecan may have reached its northern limit as early as 10,300 yr B.P. Its abundance in Early Archaic archaeological sites and the co-occurrence of early Holocene Carya pollen peaks with the arrival of the Dalton artifact complex in the Upper Mississippi Valley suggest that humans may have played a role in the early dispersal of pecan. ?? 1990.

  3. Site specific solubility improvement using solid dispersions of HPMC-AS/HPC SSL--mixtures.

    PubMed

    Zecevic, Damir Elmar; Meier, Robin; Daniels, Rolf; Wagner, Karl-Gerhard

    2014-07-01

    Many upcoming drug candidates are pH-dependent poorly soluble weak bases in the pH range of the gastrointestinal tract. This often leads to a high in vivo variability and bioavailability issues. Aiming to overcome these limitations, the design of solid dispersions for site specific dissolution improvement or maintenance of a potent supersaturation over the entire gastro-intestinal pH-range, is proposed to assure a reliable drug therapy. Solid dispersions containing different ratios of Dipyridamole (DPD) or Griseofulvin (GRI) and the enteric polymer hydroxypropylmethylcellulose-acetate succinate (HPMC-AS) and the water soluble low-viscosity hydroxypropylcellulose (HPC-SSL) were prepared by hot melt extrusion (HME). The solid dispersions were evaluated for their solid state, dissolution characteristics applying a three pH-step dissolution method following an acidic to neutral pH transition and stability. The use of HPMC-AS in binary mixtures with DPD and GRI facilitated increased solubility and supersaturation at pH-controlled release of the preserved amorphous state of the dispersed drug, which even inverted the pH-dependent solubility profile of the weakly basic model drug (Dipyridamole). I.e. a potent site specific delivery system was created. With ternary solid dispersions of API, HPMC-AS and HPC-SSL, tailored release profiles with superior supersaturation over the applied pH-range could be obtained. At the same time, binary and ternary mixtures showed favorable stability properties at a temperature difference between glass transition temperature and the applied storage temperature of down to 16°C. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. A West Valley Demonstration Project Milestone - Achieving Certification to Ship Waste to the Nevada Test Site

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jackson, J. P.; Pastor, R. S.

    2002-02-28

    The West Valley Demonstration Project (WVDP) has successfully pretreated and vitrified nearly all of the 600,000 gallons of liquid high-level radioactive waste that was generated at the site of the only commercial nuclear fuel reprocessing plant to have operated in the United States. Low-level waste (LLW) generated during the course of the cleanup effort now requires disposal. Currently the WVDP only ships Class A LLW for off-site disposal. It has been shipping Class A wastes to Envirocare of Utah, Inc. since 1997. However, the WVDP may also have a future need to ship Class B and Class C waste, whichmore » Envirocare is not currently authorized to accept. The Nevada Test Site (NTS), a U.S. Department of Energy (DOE) facility, can accept all three waste classifications. The WVDP set a goal to receive certification to begin shipping Class A wastes to NTS by 2001. Formal certification/approval was granted by the DOE Nevada Operations Office on July 12, 2001. This paper discusses how the WVDP contractor, West Valley Nuclear Services Company (WVNSCO), completed the activities required to achieve NTS certification in 2001 to ship waste to its facility. The information and lessons learned provided are significant because the WVDP is the only new generator receiving certification based on an NTS audit in January 2001 that resulted in no findings and only two observations--a rating that is unparalleled in the DOE Complex.« less

  5. Experimental and Numerical Modelling of CO2 Atmospheric Dispersion in Hazardous Gas Emission Sites.

    NASA Astrophysics Data System (ADS)

    Gasparini, A.; sainz Gracia, A. S.; Grandia, F.; Bruno, J.

    2015-12-01

    Under stable atmospheric conditions and/or in presence of topographic depressions, CO2 concentrations can reach high values resulting in lethal effect to living organisms. The distribution of denser than air gases released from the underground is governed by gravity, turbulence and dispersion. Once emitted, the gas distribution is initially driven by buoyancy and a gas cloud accumulates on the ground (gravitational phase); with time the density gradient becomes less important due to dispersion or mixing and gas distribution is mainly governed by wind and atmospheric turbulence (passive dispersion phase). Natural analogues provide evidences of the impact of CO2 leakage. Dangerous CO2 concentration in atmosphere related to underground emission have been occasionally reported although the conditions favouring the persistence of such a concentration are barely studied.In this work, the dynamics of CO2 in the atmosphere after ground emission is assessed to quantify their potential risk. Two approaches have been followed: (1) direct measurement of air concentration in a natural emission site, where formation of a "CO2 lake" is common and (2) numerical atmospheric modelling. Two sites with different morphology were studied: (a) the Cañada Real site, a flat terrain in the Volcanic Field of Campo de Calatrava (Spain); (b) the Solforata di Pomezia site, a rough terrain in the Alban Hills Volcanic Region (Italy). The comparison between field data and model calculations reveal that numerical dispersion models are capable of predicting the formation of CO2 accumulation over the ground as a consequence of underground gas emission. Therefore, atmospheric modelling could be included as a valuable methodology in the risk assessment of leakage in natural degassing systems and in CCS projects. Conclusions from this work provide clues on whether leakage may be a real risk for humans and under which conditions this risk needs to be included in the risk assessment.

  6. Slash smoke dispersal over western Oregon...a case study

    Treesearch

    John D. Dell; Franklin R. Ward; Robert E. Lynott

    1970-01-01

    Smoke from slash burns in the Cascade Mountains during a 3-day period ofstable air conditions at lower elevations in October 1969 added little to existing air pollution in the Willamette Valley, in western Oregon. Aerial observations and weather data analysis determined that slash smoke dispersed eastward — away from the Valley. Studies of this type can help improve...

  7. AmeriFlux US-SdH Nebraska SandHills Dry Valley

    DOE Data Explorer

    Arkebauer, Tim J. [University of Nebraska; Billesbach, Dave [University of Nebraska

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-SdH Nebraska SandHills Dry Valley. Site Description - The Nebraska SandHills Dry Valley tower is located on public land owned by the University of Nebraska-Lincoln. The site is on a research cattle ranch where grazing primarily takes place.

  8. WIND-TUNNEL SIMULATIONS TO ASSESS DISPERSION AROUND THE WORLD TRADE CENTER SITE

    EPA Science Inventory

    A wind-tunnel study was conducted of dispersion from the site of the destroyed World Trade Center (WTC) in New York City. A scale model of lower Manhattan, including a scaled representation of the rubble pile, was constructed. The first phases of the study involved smoke visua...

  9. Hydrogeology of a drift-filled bedrock valley near Lino Lakes, Anoka County, Minnesota

    USGS Publications Warehouse

    Winter, T.C.; Pfannkuch, H.O.

    1976-01-01

    The bedrock surface of east-central Minnesota is dissected by an intricate network of valleys. Outside the bedrock valley at site B, 3 mi (4. 8 km) from site A, 100 ft (30 m) of drift overlies the bedrock surface. Observation wells were installed at the two sites to determine the vertical ground-water movement between the various aquifer units and the lateral movement between the two sites. An aquifer test of the lowest valley-fill aquifer at site A showed that the observation well completed in the same aquifer as the pumping well responded immediately; whereas a lag of about 100 min occurred between the lower valley fill and uppermost body of sand and gravel. This indicates that the hydraulic connection between these two layers is poor at the immediate site. Test results show that the lower sand-and-gravel aquifer has a transmissivity between 14,000 and 27,000 ft2/d (1,300 and 2,500 m2/d). Although the hydraulic gradient is vertically downward in the valley, much of the drift fill is poorly permeable. This suggests that the quantity of downward-percolating water reaching the lowest valley-fill aquifer is relatively small at the test site. Because valley cut through a number of bedrock aquifers in the region, they could potentially be an important avenue of contamination from land-surface waste. In addition, the vast network of bedrock valleys in the Twin Cities area might cause contaminants to disseminate rather rapidly throughout a large area.

  10. The northwestern slope valleys (NSVs) region, Mars: A prime candidate site for the future exploration of Mars

    USGS Publications Warehouse

    Dohm, J.M.; Ferris, J.C.; Barlow, N.G.; Baker, V.R.; Mahaney, W.C.; Anderson, R.C.; Hare, T.M.

    2004-01-01

    The northwestern slope valleys region is a prime candidate site for future science-driven Mars exploration because it records Noachian to Amazonian Tharsis development in a region that encapsulates (1) a diverse and temporally extensive stratigraphic record, (2) at least three distinct paleohydrologic regimes, (3) gargantuan structurally controlled flood valleys that generally correspond with gravity and magnetic anomalies, possibly marking ancient magnetized rock materials exposed by fluvial activity, (4) water enrichment, as indicated by Mars Odyssey and impact crater analyses, (5) long-lived magma and ground water/ice interactions that could be favorable for the development and sustenance of life, and (6) potential paleosol development. This region has high probability to yield significant geologic, climatic, and exobiologic information that could revolutionize our understanding of Mars. ?? 2003 Elsevier Ltd. All rights reserved.

  11. Early Holocene pecan, Carya illinoensis, in the Mississippi River Valley near Muscatine, Iowa*1

    NASA Astrophysics Data System (ADS)

    Bettis, E. Arthur; Baker, Richard G.; Nations, Brenda K.; Benn, David W.

    1990-01-01

    A fossil pecan, Carya illinoensis (Wang.) K. Koch, from floodplain sediments of the Mississippi River near Muscatine, Iowa, was accelerator-dated at 7280 ± 120 yr B.P. This discovery indicates that pecan was at or near its present northern limit by that time. Carya pollen profiles from the Mississippi River Trench indicate that hickory pollen percentages were much higher in the valley than at upland locations during the early Holocene. Pecan, the hickory with the most restricted riparian habitat, is the likely candidate for producing these peaks in Carya pollen percentages. Therefore, pecan may have reached its northern limit as early as 10,300 yr B.P. Its abundance in Early Archaic archaeological sites and the co-occurrence of early Holocene Carya pollen peaks with the arrival of the Dalton artifact complex in the Upper Mississippi Valley suggest that humans may have played a role in the early dispersal of pecan.

  12. Site and canopy characteristics associated with oak advance reproduction in mature oak-hickory forests in the ridge and valley province in Tennessee

    Treesearch

    Leslie S. Chadwell; David S. Buckley

    2003-01-01

    To investigate hypotheses regarding effects of competitors and site quality on oak regeneration, we documented site factors and oak seedling composition, size, and abundance in the Ridge and Valley Province of Tennessee. Small oak seedlings were most abundant on productive soils and mesic landform positions, whereas large oak seedlings were most abundant on less...

  13. Radioactive dispersion analysis for hypothetical nuclear power plant (NPP) candidate site in Perak state, Malaysia

    NASA Astrophysics Data System (ADS)

    Shamsuddin, Shazmeen Daniar; Basri, Nor Afifah; Omar, Nurlyana; Koh, Meng-Hock; Ramli, Ahmad Termizi; Saridan Wan Hassan, Wan Muhamad

    2017-10-01

    Malaysia is planning to build a nuclear power plant (NPP) by 2030 to diversify the national electricity supply and resources. Selection of an NPP site must consider various factors, especially nuclear safety consideration to fulfil the nuclear safety objectives. Environmental Risk Assessment Analysis is a part of safety requirements by the International Atomic Energy Agency (IAEA) prior to the NPP commissioning process. Risk Assessments Analysis (RIA) is compulsory for the NPP site evaluation. One of RIA methods are Radioactive Dispersion Analysis using probabilistic risk analysis software. It is also important to perform studies to estimate the impact to the neighbouring population in the case of a nuclear accident at the power plant. In the present work, aimed to study the impact of a hypothetical nuclear accident by simulating the dispersion pattern of radionuclides originated from a candidate site at Manjung, Perak. The work has been performed using the HotSpot Health Physics codes. Two types of radionuclides have been considered namely 137Cs and 131I. In calculations, the initial concentration of radioactive materials of Fukushima Daiichi accident data are used which are 2.06 x 1016 Bq and 1.68 x 1017 Bq respectively for the two radionuclides. The result shows that the dispersion distance obtained from both software are not the same. It shows that 137Cs and 131I can be dispersed as far as 16 km and 80 km away from the site during radiological accident respectively, reaching major towns in Perak. Using HOTSPOT, the estimated total effective dose equivalent (TEDE) for 137Cs and 131I at major towns in Perak such as Lumut and Sitiawan are 1.2 mSv and 9.9 mSv. As for Taiping, Ipoh, Kampar, and Teluk Intan the estimated TEDE is around 0.2 mSv and 1.6 mSv respectively. In conclusion, the dispersion can reach as far as 80 km from the site. However, estimated annual effective dose is not more than 1 mSv limit, which is considered acceptable in the point of view of

  14. Logs and data from trenches across and near the Green Valley Fault at the Mason Road site, Fairfield, Solano County, California, 2006-2009

    USGS Publications Warehouse

    Lienkaemper, James J.; Sickler, Robert R.; Mahan, Shannon; Brown, Johnathan; Reidy, Liam M.; Kimball, Mindy A.

    2012-01-01

    The primary purpose of this report is to provide drafted field logs of exploratory trenches excavated across the Green Valley Fault in 2007 and 2009 that show evidence for four surface rupturing earthquakes in the past one thousand years. The site location and site detail are shown on sheet 1. The trench logs are shown on sheets 1, 2, and 3. We also provide radiocarbon laboratory dates used for chronological modeling of the earthquake history. Sheets 4 and 5 show additional data obtained in 2006–2009 to document data obtained in our studies of the long-term geologic slip rate on the Green Valley Fault. However, that effort ultimately did not prove feasible and no slip rate estimate resulted.

  15. Comparison of peak discharges among sites with and without valley fills for the July 8-9, 2001 flood in the headwaters of Clear Fork, Coal River basin, mountaintop coal-mining region, southern West Virginia

    USGS Publications Warehouse

    Wiley, Jeffrey B.; Brogan, Freddie D.

    2003-01-01

    The effects of mountaintop-removal mining practices on the peak discharges of streams were investigated in six small drainage basins within a 7-square-mile area in southern West Virginia. Two of the small basins had reclaimed valley fills, one basin had reclaimed and unreclaimed valley fills, and three basins did not have valley fills. Indirect measurements of peak discharge for the flood of July 8-9, 2001, were made at six sites on streams draining the small basins. The sites without valley fills had peak discharges with 10- to 25-year recurrence intervals, indicating that rainfall intensities and totals varied among the study basins. The flood-recurrence intervals for the three basins with valley fills were determined as though the peak discharges were those from rural streams without the influence of valley fills, and ranged from less than 2 years to more than 100 years.

  16. The Chagas disease domestic transmission cycle in Guatemala: Parasite-vector switches and lack of mitochondrial co-diversification between Triatoma dimidiata and Trypanosoma cruzi subpopulations suggest non-vectorial parasite dispersal across the Motagua valley.

    PubMed

    Pennington, Pamela M; Messenger, Louisa Alexandra; Reina, Jeffrey; Juárez, José G; Lawrence, Gena G; Dotson, Ellen M; Llewellyn, Martin S; Cordón-Rosales, Celia

    2015-11-01

    Parasites transmitted by insects must adapt to their vectors and reservoirs. Chagas disease, an American zoonosis caused by Trypanosoma cruzi, is transmitted by several species of triatomines. In Central America, Triatoma dimidiata is a widely dispersed vector found in sylvatic and domestic habitats, with distinct populations across the endemic region of Guatemala. Our aim was to test the strength of association between vector and parasite genetic divergence in domestic environments. Microsatellite (MS) loci were used to characterize parasites isolated from T. dimidiata (n=112) collected in domestic environments. Moderate genetic differentiation was observed between parasites north and south of the Motagua Valley, an ancient biogeographic barrier (FST 0.138, p=0.009). Slightly reduced genotypic diversity and increased heterozygosity in the north (Allelic richness (Ar)=1.00-6.05, FIS -0.03) compared to the south (Ar=1.47-6.30, FIS 0.022) suggest either a selective or demographic process during parasite dispersal. Based on parasite genotypes and geographic distribution, 15 vector specimens and their parasite isolates were selected for mitochondrial co-diversification analysis. Genetic variability and phylogenetic congruence were determined with mitochondrial DNA sequences (10 parasite maxicircle gene fragments and triatomine ND4+CYT b). A Mantel test as well as phylogenetic, network and principal coordinates analyses supported at least three T. dimidiata haplogroups separated by geographic distance across the Motagua Valley. Maxicircle sequences showed low T. cruzi genetic variability (π nucleotide diversity 0.00098) with no evidence of co-diversification with the vector, having multiple host switches across the valley. Sylvatic Didelphis marsupialis captured across the Motagua Valley were found to be infected with T. cruzi strains sharing MS genotypes with parasites isolated from domiciliated triatomines. The current parasite distribution in domestic environments

  17. Grizzly Valley fault system, Sierra Valley, CA

    USGS Publications Warehouse

    Gold, Ryan; Stephenson, William; Odum, Jack; Briggs, Rich; Crone, Anthony; Angster, Steve

    2012-01-01

    The Grizzly Valley fault system (GVFS) strikes northwestward across Sierra Valley, California and is part of a network of active, dextral strike-slip faults in the northern Walker Lane (Figure 1). To investigate Quaternary motion across the GVFS, we analyzed high-resolution (0.25 m) airborne LiDAR data (Figure 2) in combination with six, high-resolution, P-wave, seismic-reflection profiles [Gold and others, 2012]. The 0.5- to 2.0-km-long seismic-reflection profiles were sited orthogonal to suspected tectonic lineaments identified from previous mapping and our analysis of airborne LiDAR data. To image the upper 400–700 m of subsurface stratigraphy of Sierra Valley (Figure 3), we used a 230-kg accelerated weight drop source. Geophone spacing ranged from 2 to 5 m and shots were co-located with the geophones. The profiles reveal a highly reflective, deformed basal marker that we interpret to be the top of Tertiary volcanic rocks, overlain by a 120- to 300-m-thick suite of subhorizontal reflectors we interpret as Plio-Pleistocene lacustrine deposits. Three profiles image the principle active trace of the GVFS, which is a steeply dipping fault zone that offsets the volcanic rocks and the basin fill (Figures 4 & 5).

  18. Plastic pellets as oviposition site and means of dispersal for the ocean-skater insect Halobates.

    PubMed

    Majer, A P; Vedolin, M C; Turra, A

    2012-06-01

    Microplastics are omnipresent in the oceans and generally have negative impacts on the biota. However, flotsam may increase the availability of hard substrates, which are considered a limiting resource for some oceanic species, e.g. as oviposition sites for the ocean insect Halobates. This study describes the use of plastic pellets as an oviposition site for Halobates micans and discusses possible effects on its abundance and dispersion. Inspection of egg masses on stranded particles on beaches revealed that a mean of 24% (from 0% to 62%) of the pellets bore eggs (mean of 5 and max. of 48 eggs per pellet). Most eggs (63%) contained embryos, while 37% were empty egg shells. This shows that even small plastic particles are used as oviposition site by H. micans, and that marine litter may have a positive effect over the abundance and dispersion of this species. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Seismic local site effects characterization in the Andarax River Valley (SE Spain) from ambient seismic noise

    NASA Astrophysics Data System (ADS)

    Carmona, Enrique; García-Jerez, Antonio; Luzón, Francisco; Sánchez-Martos, Francisco; Sánchez-Sesma, Francisco J.; Piña, José

    2014-05-01

    This work is focused on the characterization of seismic local effects in the Low Andarax River Valley (SE Spain). The Low Andarax River valley is located in an active seismic region, with the higher seismic hazard values in Spain. The landform is composed mainly by sedimentary materials which increase its seismic hazard due to the amplification of the seismic inputs and spectral resonances. We study seismic local effects in the Low Andarax River by analyzing the Horizontal-to-Vertical Spectral Ratio (HVSR) of ambient noise records. The noise data were recorded during two field campaigns in 2012 and 2013. There have been a total of 374 noise measurements with 15 and 30 minutes duration. The acquisition was performed with a Digital Broadband Seismometer Guralp CMG-6TD. The distance between measurements was about 200 meters, covering an area around 40 km2. There have been 6 significant peak frequencies between 0.3 Hz and 5 Hz. It was possible to find interesting areas with similar spectral peaks that coincide with zones with similar microgravimetric anomalies at the alluvial valley. It is also observed a decrease in the frequency peaks from West to East suggesting increased sediment layer. We also compute the soil models at those sites where geotechnical information is available, assuming that the seismic noise is diffuse. We invert the HVSR for these places using horizontally layered models and in the imaginary part the Green functions at the source. It is observed that the S wave velocity inverted models are consistent with the known geotechnical information obtained from drilled boreholes. We identify the elastodynamic properties of the limestone-dolomite materials with a formation of phyllites and quartzite that form the basement of the depression, and those properties of the Miocene and Pliocene detrital deposits (marls, sandy silts, sands and conglomerates) that fill the valley. These results together with the observed resonant frequencies along the Andarax

  20. The Muralla Pircada: an ancient Andean debris flow retention dam, Santa Rita B archaeological site, Chao Valley, Northern Peru

    USGS Publications Warehouse

    Brooks, William E.; Willett, Jason C.; Kent, Jonathan D.; Vasquez, Victor; Rosales, Teresa

    2005-01-01

    Debris flows caused by El Niño events, earthquakes, and glacial releases have affected northern Perú for centuries. The Muralla Pircada, a northeast-trending, 2.5 km long stone wall east of the Santa Rita B archaeological site (Moche-Chimú) in the Chao Valley, is field evidence that ancient Andeans recognized and, more importantly, attempted to mitigate the effects of debris flows. The Muralla is upstream from the site and is perpendicular to local drainages. It is 1–2 m high, up to 5 m wide, and is comprised of intentionally-placed, well-sorted, well-rounded, 20–30 cm cobbles and boulders from nearby streams. Long axes of the stones are gently inclined and parallel local drainage. Case-and-fill construction was used with smaller cobbles and pebbles used as fill. Pre-Muralla debris flows are indicated by meter-sized, angular boulders that were incorporated in-place into construction of the dam and are now exposed in breeches in the dam. Post-Muralla debris flows in the Chao Valley are indicated by meter-sized, angular boulders that now abut the retention dam.

  1. Seismic-refraction study of suspected drift-filled bedrock valleys in Ramsey County, Minnesota

    USGS Publications Warehouse

    Woodward, D.G.

    1985-01-01

    A drift-filled bedrock valley was thought to incise the St. Peter aquifer to an altitude between 770 and 800 feet above sea level at the Koppers site. The interpretation of a seismic profile just east of the Koppers site is not conclusive, but suggests that a bedrock valley may be present near the middle of the line. The interpretation of a second seismic profile across the westward extension of the same suspected valley also is not conclusive, but suggests that a bedrock valley may be present at the north end of the line. The optimal field layout for each line at the site (longer shot offsets) could not be obtained because of limited space available in the densely developed residential neighborhoods.

  2. Understanding thermal circulations and near-surface turbulence processes in a small mountain valley

    NASA Astrophysics Data System (ADS)

    Pardyjak, E.; Dupuy, F.; Durand, P.; Gunawardena, N.; Thierry, H.; Roubin, P.

    2017-12-01

    The interaction of turbulence and thermal circulations in complex terrain can be significantly different from idealized flat terrain. In particular, near-surface horizontal spatial and temporal variability of winds and thermodynamic variables can be significant event over very small spatial scales. The KASCADE (KAtabatic winds and Stability over CAdarache for Dispersion of Effluents) 2017 conducted from January through March 2017 was designed to address these issues and to ultimately improve prediction of dispersion in complex terrain, particularly during stable atmospheric conditions. We have used a relatively large number of sensors to improve our understanding of the spatial and temporal development, evolution and breakdown of topographically driven flows. KASCADE 2017 consisted of continuous observations and fourteen Intensive Observation Periods (IOPs) conducted in the Cadarache Valley located in southeastern France. The Cadarache Valley is a relatively small valley (5 km x 1 km) with modest slopes and relatively small elevation differences between the valley floor and nearby hilltops ( 100 m). During winter, winds in the valley are light and stably stratified at night leading to thermal circulations as well as complex near-surface atmospheric layering. In this presentation we present results quantifying spatial variability of thermodynamic and turbulence variables as a function of different large -scale forcing conditions (e.g., quiescent conditions, strong westerly flow, and Mistral flow). In addition, we attempt to characterize highly-regular nocturnal horizontal wind meandering and associated turbulence statistics.

  3. Numerical Simulation of Nocturnal Drainage Flows in Idealized Valley-Tributary Systems.

    NASA Astrophysics Data System (ADS)

    O'Steen, Lance B.

    2000-11-01

    Numerical simulations of nocturnal drainage flow and transport in idealized valley-tributary systems are compared with the Atmospheric Science in Complex Terrain (ASCOT) meteorological field data and tracer studies from the Brush Creek valley of western Colorado. Much of the general valley-tributary flow behavior deduced from observations is qualitatively reproduced in the numerical results. The spatially complex, unsteady nature of the tributary flow found in the field data is also seen in the simulations. Oscillations in the simulated tributary flow are similar to some field observations. However, observed oscillations in the valley flow at the mouth of the tributary could not be reproduced in the numerical results. Thus, hypotheses of strongly coupled valley-tributary flow oscillations, based on field data, cannot be supported by these simulations. Along-valley mass flux calculations based on model results for the valley-tributary system indicate an increase of 5%-10% over a valley without a tributary. Enhanced valley mass fluxes were found from 8 km above the tributary to almost the valley mouth. However, the valley mass fluxes for topography with and without a tributary were nearly equal at the valley outflow. ASCOT field data suggested a tributary mass flow contribution of 5%-15% for a Brush Creek tributary of similar drainage area to the model tributary employed here. Numerical simulations of transport in the nocturnal valley-tributary flow strongly support ASCOT tracer studies in the Pack Canyon tributary of Brush Creek. These results suggest that the valley-tributary interaction can significantly increase plume dispersion under stable conditions. Overall, the simulation results presented here indicate that simple terrain geometries are able to capture many of the salient features of drainage flow in real valley-tributary systems.

  4. Local Population Structure and Patterns of Western Hemisphere Dispersal for Coccidioides spp., the Fungal Cause of Valley Fever

    PubMed Central

    Roe, Chandler C.; Hepp, Crystal M.; Teixeira, Marcus; Driebe, Elizabeth M.; Schupp, James M.; Gade, Lalitha; Waddell, Victor; Komatsu, Kenneth; Arathoon, Eduardo; Logemann, Heidi; Thompson, George R.; Chiller, Tom; Keim, Paul; Litvintseva, Anastasia P.

    2016-01-01

    ABSTRACT Coccidioidomycosis (or valley fever) is a fungal disease with high morbidity and mortality that affects tens of thousands of people each year. This infection is caused by two sibling species, Coccidioides immitis and C. posadasii, which are endemic to specific arid locales throughout the Western Hemisphere, particularly the desert southwest of the United States. Recent epidemiological and population genetic data suggest that the geographic range of coccidioidomycosis is expanding, as new endemic clusters have been identified in the state of Washington, well outside the established endemic range. The genetic mechanisms and epidemiological consequences of this expansion are unknown and require better understanding of the population structure and evolutionary history of these pathogens. Here we performed multiple phylogenetic inference and population genomics analyses of 68 new and 18 previously published genomes. The results provide evidence of substantial population structure in C. posadasii and demonstrate the presence of distinct geographic clades in central and southern Arizona as well as dispersed populations in Texas, Mexico, South America, and Central America. Although a smaller number of C. immitis strains were included in the analyses, some evidence of phylogeographic structure was also detected in this species, which has been historically limited to California and Baja, Mexico. Bayesian analyses indicated that C. posadasii is the more ancient of the two species and that Arizona contains the most diverse subpopulations. We propose a southern Arizona-northern Mexico origin for C. posadasii and describe a pathway for dispersal and distribution out of this region. PMID:27118594

  5. Estimation of 1-D velocity models beneath strong-motion observation sites in the Kathmandu Valley using strong-motion records from moderate-sized earthquakes

    NASA Astrophysics Data System (ADS)

    Bijukchhen, Subeg M.; Takai, Nobuo; Shigefuji, Michiko; Ichiyanagi, Masayoshi; Sasatani, Tsutomu; Sugimura, Yokito

    2017-07-01

    The Himalayan collision zone experiences many seismic activities with large earthquakes occurring at certain time intervals. The damming of the proto-Bagmati River as a result of rapid mountain-building processes created a lake in the Kathmandu Valley that eventually dried out, leaving thick unconsolidated lacustrine deposits. Previous studies have shown that the sediments are 600 m thick in the center. A location in a seismically active region, and the possible amplification of seismic waves due to thick sediments, have made Kathmandu Valley seismically vulnerable. It has suffered devastation due to earthquakes several times in the past. The development of the Kathmandu Valley into the largest urban agglomerate in Nepal has exposed a large population to seismic hazards. This vulnerability was apparent during the Gorkha Earthquake (Mw7.8) on April 25, 2015, when the main shock and ensuing aftershocks claimed more than 1700 lives and nearly 13% of buildings inside the valley were completely damaged. Preparing safe and up-to-date building codes to reduce seismic risk requires a thorough study of ground motion amplification. Characterizing subsurface velocity structure is a step toward achieving that goal. We used the records from an array of strong-motion accelerometers installed by Hokkaido University and Tribhuvan University to construct 1-D velocity models of station sites by forward modeling of low-frequency S-waves. Filtered records (0.1-0.5 Hz) from one of the accelerometers installed at a rock site during a moderate-sized (mb4.9) earthquake on August 30, 2013, and three moderate-sized (Mw5.1, Mw5.1, and Mw5.5) aftershocks of the 2015 Gorkha Earthquake were used as input motion for modeling of low-frequency S-waves. We consulted available geological maps, cross-sections, and borehole data as the basis for initial models for the sediment sites. This study shows that the basin has an undulating topography and sediment sites have deposits of varying thicknesses

  6. Principal facts for gravity stations in the Elko, Steptoe Valley, Coyote Spring Valley, and Sheep Range areas, eastern and southern Nevada

    USGS Publications Warehouse

    Berger, D.L.; Schaefer, D.H.; Frick, E.A.

    1990-01-01

    Principal facts for 537 gravity stations in the carbonate-rock province of eastern and southern Nevada are tabulated and presented. The gravity data were collected in support of groundwater studies in several valleys. The study areas include the Elko area, northern Steptoe Valley, Coyote Spring Valley, and the western Sheep Range area. The data for each site include values for latitude, longitude, altitude, observed gravity, free- air anomaly, terrain correction, and Bouguer anomaly (calculated at a bedrock density of 2.67 g/cu cm. (USGS)

  7. Venturing out safely: The biogeography of Homo erectus dispersal out of Africa.

    PubMed

    Carotenuto, F; Tsikaridze, N; Rook, L; Lordkipanidze, D; Longo, Laura; Condemi, Silvana; Raia, P

    2016-06-01

    The dispersal of Homo erectus out of Africa at some 1.9 million years ago is one of the most important, crucial, and yet controversial events in human evolution. Current opinions about this episode expose the contrast between those who see H. erectus as a highly social, cooperative species seeking out new ecological opportunities to exploit, and those preferring a passive, climate driven explanation for such an event. By using geostatistics techniques and probabilistic models, we characterised the ecological context of H. erectus dispersal, from its East African origin to the colonization of Eurasia, taking into account both the presence of other large mammals and the physical characteristics of the landscape as potential factors. Our model indicated that H. erectus followed almost passively the large herbivore fauna during its dispersal. In Africa, the dispersal was statistically associated with the presence of large freshwater bodies (Rift Valley Lakes). In Eurasia, the presence of H. erectus was associated with the occurrence of geological outcrops likely yielding unconsolidated flint. During the early phase of dispersal, our model indicated that H. erectus actively avoided areas densely populated by large carnivores. This pattern weakened as H. erectus dispersed over Europe, possibly because of the decreasing presence of carnivores there plus the later acquisition of Acheulean technology. During this later phase, H. erectus was associated with limestone and shaley marl, and seems to have been selecting for high-elevation sites. While our results do not directly contradict the idea that H. erectus may have been an active hunter, they clearly point to the fact that predator avoidance may have conditioned its long-distance diffusion as it moved outside Africa. The modelled dispersal route suggests that H. erectus remained preferentially associated with low/middle latitude (i.e., comparatively warm) sites throughout its colonization history. Copyright

  8. The Las Vegas Valley Seismic Response Project: Ground Motions in Las Vegas Valley from Nuclear Explosions at the Nevada Test Site

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rodgers, A; Tkalcic, H; McCallen, D

    2005-03-18

    Between 2001-2004 the Las Vegas Seismic Response Project has sought to understand the response of Las Vegas Valley (LVV) to seismic excitation. In this study, the author report the findings of this project with an emphasis on ground motions in LVV from nuclear explosions at the Nevada Test Site (NTS). These ground motions are used to understand building structural response and damage as well as human perception. Historical nuclear explosion observations are augmented with earthquake recordings from a temporary deployment of seismometers to improve spatial coverage of LVV. The nuclear explosions were conducted between 1968 and 1989 and were recordedmore » at various sites within Las Vegas. The data from past nuclear tests were used to constrain ground motions in LVV and to gain a predictive capability of ground motions for possible future nuclear tests at NTS. Analysis of ground motion data includes peak ground motions (accelerations and velocities) and amplification of basin sites relative to hard rock sites (site response). Site response was measured with the Standard Spectral Ratios (SSR) technique relative to hard rock reference sites on the periphery of LVV. The site response curves indicate a strong basin amplification of up to a factor of ten at frequencies between 0.5-2 Hz. Amplifications are strongest in the central and northern portions of LVV, where the basin is deeper than 1 km based on the reported basin depths of Langenheim et al (2001a). They found a strong correlation between amplification and basin depth and shallow shear wave velocities. Amplification below 1 Hz is strongly controlled by slowness-averaged shear velocities to depths of 30 and 100 meters. Depth averaged shear velocities to 10 meters has modest control of amplifications between 1-3 Hz. Modeling reveals that low velocity material in the shallow layers (< 200 m) effectively controls amplification. They developed a method to scale nuclear explosion ground motion time series to sites

  9. Hydrologic Evaluation of the Jungo Area, Southern Desert Valley, Nevada

    USGS Publications Warehouse

    Lopes, Thomas J.

    2010-01-01

    RecologyTM, the primary San Francisco waste-disposal entity, is proposing to develop a Class 1 landfill near Jungo, Nevada. The proposal calls for the landfill to receive by rail about 20,000 tons of waste per week for up to 50 years. On September 22, 2009, the Interior Appropriation (S.A. 2494) was amended to require the U.S. Geological Survey to evaluate the proposed Jungo landfill site for: (1) potential water-quality impacts on nearby surface-water resources, including Rye Patch Reservoir and the Humboldt River; (2) potential impacts on municipal water resources of Winnemucca, Nevada; (3) locations and altitudes of aquifers; (4) how long it will take waste seepage from the site to contaminate local aquifers; and (5) the direction and distance that contaminated groundwater would travel at 95 and 190 years. This evaluation was based on review of existing data and information. Desert Valley is tributary to the Black Rock Desert via the Quinn River in northern Desert Valley. The Humboldt River and Rye Patch Reservoir would not be affected by surface releases from the proposed Jungo landfill site because they are in the Humboldt basin. Winnemucca, on the Humboldt River, is 30 miles east of the Jungo landfill site and in the Humboldt basin. Groundwater-flow directions indicate that subsurface flow near the proposed Jungo landfill site is toward the south-southwest. Therefore, municipal water resources of Winnemucca would not be affected by surface or subsurface releases from the proposed Jungo landfill site. Basin-fill aquifers underlie the 680-square-mile valley floor in Desert Valley. Altitudes around the proposed Jungo landfill site range from 4,162 to 4,175 feet. Depth to groundwater is fairly shallow in southern Desert Valley and is about 60 feet below land surface at the proposed Jungo landfill site. A groundwater divide exists about 7 miles north of the proposed Jungo landfill site. Groundwater north of the divide flows north towards the Quinn River. South of

  10. Groundwater sapping valleys: Experimental studies, geological controls and implications to the interpretation of valley networks on Mars

    NASA Technical Reports Server (NTRS)

    Kochel, R. Craig

    1988-01-01

    An integrated approach using experimental laboratory models, field studies of terrestrial analogs, and remote studies of terrestrial field sites were applied to the goals of understanding the nature and morphology of valley networks formed by groundwater sapping. In spite of problems with scaling, the experimental studies provide valuable insights into concepts relating to the initiation, development, and evolution of valleys by groundwater sapping. These investigations are also aimed at developing geomorphic criteria for distinguishing valleys formed by surface runoff from those formed by groundwater sapping processes. Channels that were field classified as sapping vs. runoff were successfully distinguished using statistical analysis of their respective morphologies; therefore, it may be possible to use similar techniques to interpret channel genesis on Mars. The terrestrial and flume studies provide the ground truth dataset which can be used (and will be during the present year) to help interpret the genesis of valley networks on Mars.

  11. Magnetotelluric Data, Mid Valley, Nevada Test Site, Nevada

    USGS Publications Warehouse

    Williams, Jackie M.; Wallin, Erin L.; Rodriguez, Brian D.; Lindsey, Charles R.; Sampson, Jay A.

    2007-01-01

    Introduction The United States Department of Energy (DOE) and the National Nuclear Security Administration (NNSA) at their Nevada Site Office (NSO) are addressing ground-water contamination resulting from historical underground nuclear testing through the Environmental Management (EM) program and, in particular, the Underground Test Area (UGTA) project. One issue of concern is the nature of the somewhat poorly constrained pre-Tertiary geology and its effects on ground-water flow. Ground-water modelers would like to know more about the hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Rainier Mesa/Shoshone Mountain Corrective Action Unit (CAU). During 2003, the U.S. Geological Survey (USGS), in cooperation with the DOE and NNSA-NSO, collected and processed data at the Nevada Test Site in and near Yucca Flat (YF) to help define the character, thickness, and lateral extent of the pre-Tertiary confining units. We collected 51 magnetotelluric (MT) and audio-magnetotelluric (AMT), stations for that research. In early 2005 we extended that research with 26 additional MT data stations, located on and near Rainier Mesa and Shoshone Mountain (RM-SM). The new stations extended the area of the hydrogeologic study previously conducted in Yucca Flat. This work was done to help refine what is known about the character, thickness, and lateral extent of pre-Tertiary confining units. In particular, a major goal was to define the upper clastic confining unit (UCCU). The UCCU is comprised of late Devonian to Mississippian siliciclastic rocks assigned to the Eleana Formation and Chainman Shale. The UCCU underlies the Yucca Flat area and extends westward towards Shoshone Mountain, southward to Buckboard Mesa, and northward to Rainier Mesa. Late in 2005 we collected another 14 MT stations in Mid Valley and in northern Yucca Flat basin. That work was done to better determine the extent and thickness of the UCCU near

  12. Advanced seismic imaging of overdeepened alpine valleys

    NASA Astrophysics Data System (ADS)

    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

  13. The Passy-2015 field experiment: wintertime atmospheric dynamics and air quality in a narrow alpine valley

    NASA Astrophysics Data System (ADS)

    Paci, Alexandre; Staquet, Chantal

    2016-04-01

    Wintertime anticyclonic conditions lead to the formation of persistent stable boundary layers which may induce severe air pollution episodes in urban or industrialized area, particularly in mountain regions. The Arve river valley in the Northern Alps is very sensitive to this phenomenon, in particular close to the city of Passy (Haute-Savoie), 20 km down valley past Chamonix. This place is indeed one of the worst place in France regarding air quality, the concentration of fine particles and Benzo(a)pyrene (a carcinogenic organic compound) regularly exceeding the EU legal admissible level during winter. Besides air quality measurements, such as the ones presently carried in the area by the local air quality agency Air Rhône-Alpes or in the DECOMBIO project led by LGGE, it is crucial to improve our knowledge of the atmospheric boundary layer dynamics and processes at the valley scale under these persistent stable conditions in order to improve our understanding on how it drives pollutant dispersion. These issues motivated the Passy-2015 field experiment which took place during the winter 2014-2015. A relatively large set-up of instruments was deployed on a main measurement site in the valley center and on four other satellite sites. It includes several remote sensing instruments, a surface flux station, a 10 m instrumented tower, a large aperture scintillometer, a fog monitoring station among others. Most of the instruments were present from early January to the end of February. During two intensive observation periods, 6-14 February and 17-20 February, the instrumental set-up was completed on the main site with high frequency radio-soundings (up to one per 1h30), a tethered balloon, a remote controlled drone quadcopter and a sodar. The field campaign, the instruments, the meteorological situations observed and preliminary results will be presented. This field experiment is part of the Passy project funded by ADEME through the French national programme LEFE/INSU and

  14. Meteorology drives ambient air quality in a valley: a case of Sukinda chromite mine, one among the ten most polluted areas in the world.

    PubMed

    Mishra, Soumya Ranjan; Pradhan, Rudra Pratap; Prusty, B Anjan Kumar; Sahu, Sanjat Kumar

    2016-07-01

    The ambient air quality (AAQ) assessment was undertaken in Sukinda Valley, the chromite hub of India. The possible correlations of meteorological variables with different air quality parameters (PM10, PM2.5, SO2, NO2 and CO) were examined. Being the fourth most polluted area in the globe, Sukinda Valley has always been under attention of researchers, for hexavalent chromium contamination of water. The monitoring was carried out from December 2013 through May 2014 at six strategic locations in the residential and commercial areas around the mining cluster of Sukinda Valley considering the guidelines of Central Pollution Control Board (CPCB). In addition, meteorological parameters viz., temperature, relative humidity, wind speed, wind direction and rainfall, were also monitored. The air quality data were subjected to a general linear model (GLM) coupled with one-way analysis of variance (ANOVA) test for testing the significant difference in the concentration of various parameters among seasons and stations. Further, a two-tailed Pearson's correlation test helped in understanding the influence of meteorological parameters on dispersion of pollutants in the area. All the monitored air quality parameters varied significantly among the monitoring stations suggesting (i) the distance of sampling location to the mine site and other allied activities, (ii) landscape features and topography and (iii) meteorological parameters to be the forcing functions. The area was highly polluted with particulate matters, and in most of the cases, the PM level exceeded the National Ambient Air Quality Standards (NAAQS). The meteorological parameters seemed to play a major role in the dispersion of pollutants around the mine clusters. The role of wind direction, wind speed and temperature was apparent in dispersion of the particulate matters from their source of generation to the surrounding residential and commercial areas of the mine.

  15. Transport of particle pollution into the Maipo Valley: winter 2015 campaign results

    NASA Astrophysics Data System (ADS)

    Huneeus, Nicolás; Mazzeo, Andrea; Ordóñez, César; Donoso, Nicolás; Gallardo, Laura; Molina, Luisa; Moreno, Valeria; Muñoz, Ricardo; Orfanoz, Andrea; Vizcarra, Aldo

    2016-04-01

    Each winter, Santiago (33° 27'S, 70° 40'W) the capital of Chile with a population of about 7 million people, experiences episodes with particulate matter (PM) concentrations larger than allowed by Chilean environmental regulations. Transport and residential heating largely dominate emissions prior to and during these episodes. Important impact of black carbon (BC) on the cryosphere has been documented in other parts of the world associated with urban pollution. In order to explore if BC from Santiago has the potential to reach the Andean cryosphere during the aforementioned episodes, a one week-long campaign was conducted in Santiago and the Maipo Valley between 18th and 25th of July 2015 when the air quality conditions of the city reached twice the critical levels (pre-emergency in Chilean regulations). Measurements were carried out at three sites: downtown Santiago, the entrance of the valley (and outskirts of Santiago) and 12 km inside the Maipo Valley. At each of these sites both surface and vertically distributed measurements were conducted. A meteorological station measuring standard meteorological parameters and an E-Sampler measuring PM10 concentrations were installed at each site. In addition, a tethered balloon equipped with a sonde and a mini-aethalometer was used in each site to measure vertical profiles of standard meteorological parameters and BC concentrations, respectively. The tethered balloon was raised every three hours up to a maximum of 1000 meters above ground level, whenever meteorological conditions allowed. In general, the BC concentrations inside the valley, both at the surface and in the vertical, were dominated by emissions within the valley and BC was limited to shallow layers above the ground. However, on both days with critical air quality levels, winds blowing from the city and deeper BC layers were observed inside the valley. Furthermore, during these days observations at the entrance of the valley and those taken inside were

  16. TL dating of pottery fragments from four archaeological sites in Taquari Valley, Brazil

    NASA Astrophysics Data System (ADS)

    Cano, Nilo F.; Machado, Neli T. G.; Gennari, Roseli F.; Rocca, Rene R.; Munita, Casimiro S.; Watanabe, Shigueo

    2012-12-01

    Sixty-three pottery fragments from four archaeological sites, numbered RST110, RST101, RST114 and RST114, in the Taquari Valley, vicinity of the city of Lajeado, Rio Grande do Sul state, southern Brazil, have been dated by the thermoluminescence method. Some of them from RST110 and RST101 are as old as 1400-1200 years, whereas those from RST114 and RST107 are younger than 800 years. This result indicates that RST101 and RST110 were peopled earlier than RST114 and RST107. The recent dates found are 302, 295 and 146 years and they are possible, since the first German immigrants who arrived in this region encountered Tupi-Guarani Indians still living there. One interesting result refers to the glow curves of quartz grains RST110, RST101 and RST114 that differ from the glow curves of RST107 quartz grains.

  17. Fretted Terrain Valley in Coloe Fossae Region

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Figure 1 Click on image for larger version

    The image in figure 1 shows lineated valley fill in one of a series of enclosed, intersecting troughs known as Coloe (Choloe) Fossae. Lineated valley fill consists of rows of material in valley centers that are parallel to the valley walls. It is probably made of ice-rich material and boulders that are left behind when the ice-rich material sublimates. Very distinct rows can be seen near the south (bottom) wall of the valley. Lineated valley fill is thought to result from mass wasting (downslope movement) of ice-rich material from valley walls towards their centers. It is commonly found in valleys near the crustal dichotomy that separates the two hemispheres of Mars. The valley shown here joins four other valleys with lineated fill near the top left corner of this image. Their juncture is a topographic low, suggesting that the lineated valley fill from the different valleys may be flowing or creeping towards the low area (movement towards the upper left of the image). The valley walls appear smooth at first glance but are seen to be speckled with small craters several meters in diameter at HiRISE resolution (see contrast-enhanced subimage). This indicates that at least some of the wall material has been stable to mass wasting for some period of time. Also seen on the valley wall are elongated features shaped like teardrops. These are most likely slightly older craters that have been degraded due to potentially recent downhill creep. It is unknown whether the valley walls are shedding material today. The subimage is approximately 140 x 400 m (450 x 1280 ft).

    Image PSP_001372_2160 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on November 11, 2006. The complete image is centered at 35.5 degrees latitude, 56.8 degrees East longitude. The range to the target site was 290.3 km (181

  18. Limnology of the Green Lakes Valley: Phytoplankton ecology and dissolved organic matter biogeochemistry at a long-term ecological research site

    USGS Publications Warehouse

    Miller, Matthew P.; McKnight, Diane M.

    2015-01-01

    Background: Surface waters are the lowest points in the landscape, and therefore serve as excellent integrators and indicators of changes taking place in the surrounding terrestrial and atmospheric environment.Aims: Here we synthesise the findings of limnological studies conducted during the past 15 years in streams and lakes in the Green Lakes Valley, which is part of the Niwot Ridge Long-term Ecological Research (LTER) Site.Methods: The importance of these studies is discussed in the context of aquatic ecosystems as indicators, integrators, and regulators of environmental change. Specifically, investigations into climatic, hydrologic, and nutrient controls on present-day phytoplankton, and historical diatom, community composition in the alpine lake, Green Lake 4, are reviewed. In addition, studies of spatial and temporal patterns in dissolved organic matter (DOM) biogeochemistry and reactive transport modelling that have taken place in the Green Lakes Valley are highlighted.Results and conclusions: The findings of these studies identify specific shifts in algal community composition and DOM biogeochemistry that are indicative of changing environmental conditions and provide a framework for detecting future environmental change in the Green Lakes Valley and in other alpine watersheds. Moreover, the studies summarised here demonstrate the importance of long-term monitoring programmes such as the LTER programme.

  19. Geologic, water-chemistry, and hydrologic data from multiple-well monitoring sites and selected water-supply wells in the Santa Clara Valley, California, 1999-2003

    USGS Publications Warehouse

    Newhouse, M.W.; Hanson, R.T.; Wentworth, C.M.; Everett, Rhett; Williams, C.F.; Tinsley, J.C.; Noce, T.E.; Carkin, B.A.

    2004-01-01

    To better identify the three-dimensional geohydrologic framework of the Santa Clara Valley, lithologic, geologic, geophysical, geomechanical, hydraulic, and water-chemistry data were collected from eight ground-water multiple-well monitoring sites constructed in Santa Clara County, California, as part of a series of cooperative studies between the U.S. Geological Survey and the Santa Clara Valley Water District. The data are being used to update and improve the three-dimensional geohydrologic framework of the basin and to address issues related to water supply, water chemistry, sequence stratigraphy, geology, and geological hazards. This report represents a compilation of data collected from 1999 to 2003, including location and design of the monitoring sites, cone penetrometer borings, geologic logs, lithologic logs, geophysical logs, core analysis, water-chemistry analysis, ground-water-level measurements, and hydraulic and geomechanical properties from wells and core samples. Exploratory cone penetrometer borings taken in the upper 17 to 130 feet at six of the monitoring sites identified the base of Holocene as no deeper than 75 feet in the central confined area and no deeper than 35 feet in the southern unconfined areas of the valley. Generalized lithologic characterization from the monitoring sites indicates about four to six different aquifer units separated by relatively fine-grained units occur within the alluvial deposits shallower than 860 feet deep. Analysis of geophysical logs indicates that coarse-grained units varied in thickness between 10 and 25 feet in the southeastern unconfined area of the valley and between 50 and 200 feet in the south-central and southwestern areas of the valley. Deviations from temperature-gradient logs indicate that the majority of horizontal ground-water flow occurs above a depth of 775 feet in the south central and above 510 feet in the southeastern areas of the valley. Bulk physical properties from more than 1,150 feet of

  20. Pumpernickel Valley Geothermal Project Thermal Gradient Wells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Z. Adam Szybinski

    2006-01-01

    , PVTG-1, -2, -3, and -4, and all four encountered geothermal fluids. The holes provided valuable water geochemistry, supporting the geothermometry results obtained from the hot springs and Magma well. The temperature data gathered from all the wells clearly indicates the presence of a major plume of thermal water centered on the Pumpernickel Valley fault, and suggests that the main plume is controlled, at least in part, by flow from this fault system. The temperature data also defines the geothermal resource with gradients >100oC/km, which covers an area a minimum of 8 km2. Structural blocks, down dropped with respect to the Pumpernickel Valley fault, may define an immediate reservoir. The geothermal system almost certainly continues beyond the recently drilled holes and might be open to the east and south, whereas the heat source responsible for the temperatures associated with this plume has not been intersected and must be at a depth greater than 920 meters (depth of the deepest well – Magma well). The geological and structural setting and other characteristics of the Pumpernickel Valley geothermal project area are markedly similar to the portions of the nearby Dixie Valley geothermal field. These similarities include, among others, the numerous, unexposed en echelon faults and large-scale pull-apart structure, which in Dixie Valley may host part of the geothermal field. The Pumpernickel Valley project area, for the majority of which Nevada Geothermal Power Company has geothermal rights, represents a geothermal site with a potential for the discovery of a relatively high temperature reservoir suitable for electric power production. Among locations not previously identified as having high geothermal potential, Pumpernickel Valley has been ranked as one of four sites with the highest potential for electrical power production in Nevada (Shevenell and Garside, 2003). Richards and Blackwell (2002) estimated the total heat loss and the preliminary production capacity for

  1. Transboundary Contributions To Surface Ozone In California's Central Valley

    NASA Astrophysics Data System (ADS)

    Post, A.; Faloona, I. C.; Conley, S. A.; Lighthall, D.

    2014-12-01

    Rising concern over the impacts of exogenous air pollution in California's Central Valley has prompted the establishment of a coastal, high altitude monitoring site at the Chews Ridge Observatory (1550 m) approximately 30 km east of Point Sur in Monterey County, under the auspices of the Monterey Institute for Research in Astronomy. Two and a half years of continuous ozone data are presented in the context of long-range transport and its potential impact on surface air quality in the San Joaquin Valley (SJV). Past attempts to quantify the impact of transboundary ozone on surface levels have relied on uncertain model estimates, or have been limited to weekly ozonesonde data. Here, we present an observationally derived quantification of the contribution of free tropospheric ozone to surface sites in the San Joaquin Valley throughout three ozone seasons (June through September, 2012-2014). The diurnal ozone patterns at Chews Ridge, and their correlations with ozone aloft over the Valley, have been presented previously. Furthermore, reanalysis data of geopotential heights indicate consistent flow from Chews Ridge to the East, directly over the SJV. In a related airborne project we quantify the vertical exchange, or entrainment, rate over the Southern SJV from a series of focused flights measuring ozone concentrations during peak photochemical hours in conjunction with local meteorological data to quantify an ozone budget for the area. By applying the entrainment rates observed in that study here we are able to quantify the seasonal contributions of free tropospheric ozone measured at Chews Ridge to surface sites in the San Joaquin Valley, and compare prior model estimates to our observationally derived values.

  2. An evaluation of the regional acid deposition model surface module for ozone uptake at three sites in the San Joaquin Valley of California

    NASA Technical Reports Server (NTRS)

    Massman, W. J.; Pederson, J.; Delany, A.; Grantz, D.; Hertog, G. Den; Neumann, H. H.; Oncley, S. P.; Pearson, R., Jr.; Shaw, R. H.

    1994-01-01

    Plants and soils act as major sinks for the destruction of tropospheric ozone, especially during daylight hours when plant stomata open and are thought to provide the dominant pathway for the uptake of ozone. The present study, part of the California Ozone Deposition Experiment, compares predictions of the regional acid deposition model ozone surface conductance module with surface conductance data derived from eddy covariance measurements of ozone flux taken at a grape, a cotton, and a grassland site in the San Joaquin Valley of California during the summer of 1991. Results indicate that the model (which was developed to provide long-term large-area estimates for the eastern United States) significantly overpredicts the surface conductance at all times of the day for at least two important types of plant cover of the San Joaquin Valley and that it incorrectly partitions the ozone flux between transpiring and nontranspiring components of the surface at the third site. Consequently, the model either overpredicts or inaccurately represents the observed deposition velocities. Other results indicate that the presence of dew does not reduce the rate of ozone deposition, contradicting to model assumptions, and that model assumptions involving the dependency of stomata upon environmental temperature are unnecessary. The effects of measurement errors and biases, arising from the presence of the roughness sublayer and possible photochemical reactions, are also discussed. A simpler model for ozone surface deposition (at least for the San Joaquin Valley) is proposed and evaluated.

  3. Water-Quality Data for Selected Stream Sites in Bridgeport Valley, Mono County, California, April 2000 to June 2003

    USGS Publications Warehouse

    Rockwell, Gerald L.; Honeywell, Paul D.

    2004-01-01

    The U.S. Geological Survey, in cooperation with the California Regional Water Quality Control Board, Lahonton Region, carried out a water-quality data collection program of selected streams in and near Bridgeport Valley, California, during April 2000 to June 2003. These data were collected to provide information used by the California Regional Water Quality Control Board to develop total maximum daily load standards. Field measurements of streamflow, barometric pressure, dissolved oxygen, pH, specific conductance, and water temperature were made at 15 sites located on 6 streams. Water samples were analyzed for nutrients, major ions, turbidity, fecal coliform, fecal streptococci, and suspended sediment. Field data, turbidity, nutrient, major ion, and sediment concentrations and fecal coliform and fecal streptococci densities are given in tables for each site. Field blank data are also presented in a table.

  4. Debris flow occurrence and sediment persistence, Upper Colorado River Valley, CO

    USGS Publications Warehouse

    Grimsley, Kyle J; Rathburn, Sara L.; Friedman, Jonathan M.; Mangano, Joseph F.

    2016-01-01

    Debris flow magnitudes and frequencies are compared across the Upper Colorado River valley to assess influences on debris flow occurrence and to evaluate valley geometry effects on sediment persistence. Dendrochronology, field mapping, and aerial photographic analysis are used to evaluate whether a 19th century earthen, water-conveyance ditch has altered the regime of debris flow occurrence in the Colorado River headwaters. Identifying any shifts in disturbance processes or changes in magnitudes and frequencies of occurrence is fundamental to establishing the historical range of variability (HRV) at the site. We found no substantial difference in frequency of debris flows cataloged at eleven sites of deposition between the east (8) and west (11) sides of the Colorado River valley over the last century, but four of the five largest debris flows originated on the west side of the valley in association with the earthen ditch, while the fifth is on a steep hillslope of hydrothermally altered rock on the east side. These results suggest that the ditch has altered the regime of debris flow activity in the Colorado River headwaters as compared to HRV by increasing the frequency of debris flows large enough to reach the Colorado River valley. Valley confinement is a dominant control on response to debris flows, influencing volumes of aggradation and persistence of debris flow deposits. Large, frequent debris flows, exceeding HRV, create persistent effects due to valley geometry and geomorphic setting conducive to sediment storage that are easily delineated by valley confinement ratios which are useful to land managers.

  5. Debris Flow Occurrence and Sediment Persistence, Upper Colorado River Valley, CO

    NASA Astrophysics Data System (ADS)

    Grimsley, K. J.; Rathburn, S. L.; Friedman, J. M.; Mangano, J. F.

    2016-07-01

    Debris flow magnitudes and frequencies are compared across the Upper Colorado River valley to assess influences on debris flow occurrence and to evaluate valley geometry effects on sediment persistence. Dendrochronology, field mapping, and aerial photographic analysis are used to evaluate whether a 19th century earthen, water-conveyance ditch has altered the regime of debris flow occurrence in the Colorado River headwaters. Identifying any shifts in disturbance processes or changes in magnitudes and frequencies of occurrence is fundamental to establishing the historical range of variability (HRV) at the site. We found no substantial difference in frequency of debris flows cataloged at eleven sites of deposition between the east (8) and west (11) sides of the Colorado River valley over the last century, but four of the five largest debris flows originated on the west side of the valley in association with the earthen ditch, while the fifth is on a steep hillslope of hydrothermally altered rock on the east side. These results suggest that the ditch has altered the regime of debris flow activity in the Colorado River headwaters as compared to HRV by increasing the frequency of debris flows large enough to reach the Colorado River valley. Valley confinement is a dominant control on response to debris flows, influencing volumes of aggradation and persistence of debris flow deposits. Large, frequent debris flows, exceeding HRV, create persistent effects due to valley geometry and geomorphic setting conducive to sediment storage that are easily delineated by valley confinement ratios which are useful to land managers.

  6. Debris Flow Occurrence and Sediment Persistence, Upper Colorado River Valley, CO.

    PubMed

    Grimsley, K J; Rathburn, S L; Friedman, J M; Mangano, J F

    2016-07-01

    Debris flow magnitudes and frequencies are compared across the Upper Colorado River valley to assess influences on debris flow occurrence and to evaluate valley geometry effects on sediment persistence. Dendrochronology, field mapping, and aerial photographic analysis are used to evaluate whether a 19th century earthen, water-conveyance ditch has altered the regime of debris flow occurrence in the Colorado River headwaters. Identifying any shifts in disturbance processes or changes in magnitudes and frequencies of occurrence is fundamental to establishing the historical range of variability (HRV) at the site. We found no substantial difference in frequency of debris flows cataloged at eleven sites of deposition between the east (8) and west (11) sides of the Colorado River valley over the last century, but four of the five largest debris flows originated on the west side of the valley in association with the earthen ditch, while the fifth is on a steep hillslope of hydrothermally altered rock on the east side. These results suggest that the ditch has altered the regime of debris flow activity in the Colorado River headwaters as compared to HRV by increasing the frequency of debris flows large enough to reach the Colorado River valley. Valley confinement is a dominant control on response to debris flows, influencing volumes of aggradation and persistence of debris flow deposits. Large, frequent debris flows, exceeding HRV, create persistent effects due to valley geometry and geomorphic setting conducive to sediment storage that are easily delineated by valley confinement ratios which are useful to land managers.

  7. Assessment of AVIRIS data from vegetated sites in the Owens Valley, California

    NASA Technical Reports Server (NTRS)

    Rock, B. N.; Elvidge, Christopher D.; Defeo, N. J.

    1988-01-01

    Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data were acquired from the Bishop, CA area, located at the northern end of the Owens Valley, on July 30, 1987. Radiometrically-corrected AVIRIS data were flat-field corrected, and spectral curves produced and analyzed for pixels taken from both native and cultivated vegetation sites, using the JPS SPAM software program and PC-based spreadsheet programs. Analyses focussed on the chlorophyll well and red edge portions of the spectral curves. Results include the following: AVIRIS spectral data are acquired at sufficient spectral resolution to allow detection of blue shifts of both the chlorophyll well and red edge in moisture-stressed vegetation when compared with non-stressed vegetation; a normalization of selected parameters (chlorophyll well and near infrared shoulder) may be used to emphasize the shift in red edge position; and the presence of the red edge in AVIRIS spectral curves may be useful in detecting small amounts (20 to 30 pct cover) of semi-arid and arid vegetation ground cover. A discussion of possible causes of AVIRIS red edge shifts in respsonse to stress is presented.

  8. Magnetotelluric Data, Mid Valley, Nevada Test Site, Nevada.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jackie M. Williams; Erin L. Wallin; Brian D. Rodriguez

    2007-08-15

    The United States Department of Energy (DOE) and the National Nuclear Security Administration (NNSA) at their Nevada Site Office (NSO) are addressing ground-water contamination resulting from historical underground nuclear testing through the Environmental Management (EM) program and, in particular, the Underground Test Area (UGTA) project. One issue of concern is the nature of the somewhat poorly constrained pre-Tertiary geology and its effects on ground-water flow. Ground-water modelers would like to know more about the hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Rainier Mesa/Shoshone Mountain Corrective Action Unit (CAU) (Bechtel Nevada, 2006).more » During 2003, the U.S. Geological Survey (USGS), in cooperation with the DOE and NNSA-NSO, collected and processed data at the Nevada Test Site in and near Yucca Flat (YF) to help define the character, thickness, and lateral extent of the pre-tertiary confining units. We collected 51 magnetotelluric (MT) and audio-magnetotelluric (AMT), stations for that research (Williams and others, 2005a, 2005b, 2005c, 2005d, 2005e, 2005f). In early 2005 we extended that research with 26 additional MT data stations (Williams and others, 2006), located on and near Rainier Mesa and Shoshone Mountain (RM-SM). The new stations extended the area of the hydrogeologic study previously conducted in Yucca Flat. This work was done to help refine what is known about the character, thickness, and lateral extent of pre-Tertiary confining units. In particular, a major goal was to define the upper clastic confining unit (UCCU). The UCCU is comprised of late Devonian to Mississippian siliciclastic rocks assigned to the Eleana Formation and Chainman Shale. The UCCU underlies the Yucca Flat area and extends westward towards Shoshone Mountain, southward to Buckboard Mesa, and northward to Rainier Mesa. Late in 2005 we collected another 14 MT stations in Mid Valley and

  9. Comparisons of shear-wave slowness in the Santa Clara Valley, California using blind interpretations of data from invasive and noninvasive methods

    USGS Publications Warehouse

    Boore, D.M.; Asten, M.W.

    2008-01-01

    Many groups contributed to a blind interpretation exercise for the determination of shear-wave slowness beneath the Santa Clara Valley. The methods included invasive methods in deep boreholes as well as noninvasive methods using active and passive sources, at six sites within the valley (with most investigations being conducted at a pair of closely spaced sites near the center of the valley). Although significant variability exists between the models, the slownesses from the various methods are similar enough that linear site amplifications estimated in several ways are generally within 20% of one another. The methods were able to derive slownesses that increase systematically with distance from the valley edge, corresponding to a tendency for the sites to be underlain by finer-grained materials away from the valley edge. This variation is in agreement with measurements made in the boreholes at the sites.

  10. Earth-observing satellite intercomparison using the Radiometric Calibration Test Site at Railroad Valley

    NASA Astrophysics Data System (ADS)

    Czapla-Myers, Jeffrey; McCorkel, Joel; Anderson, Nikolaus; Biggar, Stuart

    2018-01-01

    This paper describes the current ground-based calibration results of Landsat 7 Enhanced Thematic Mapper Plus (ETM+), Landsat 8 Operational Land Imager (OLI), Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS), Suomi National Polar orbiting Partnership Visible Infrared Imaging Radiometer Suite (VIIRS), and Sentinel-2A Multispectral Instrument (MSI), using an automated suite of instruments located at Railroad Valley, Nevada, USA. The period of this study is 2012 to 2016 for MODIS, VIIRS, and ETM+, 2013 to 2016 for OLI, and 2015 to 2016 for MSI. The current results show that all sensors agree with the Radiometric Calibration Test Site (RadCaTS) to within ±5% in the solar-reflective regime, except for one band on VIIRS that is within ±6%. In the case of ETM+ and OLI, the agreement is within ±3%, and, in the case of MODIS, the agreement is within ±3.5%. MSI agrees with RadCaTS to within ±4.5% in all applicable bands.

  11. Variability of site response in Seattle, Washington

    USGS Publications Warehouse

    Hartzell, S.; Carver, D.; Cranswick, E.; Frankel, A.

    2000-01-01

    Ground motion from local earthquakes and the SHIPS (Seismic Hazards Investigation in Puget Sound) experiment is used to estimate site amplification factors in Seattle. Earthquake and SHIPS records are analyzed by two methods: (1) spectral ratios relative to a nearby site on Tertiary sandstone, and (2) a source/site spectral inversion technique. Our results show site amplifications between 3 and 4 below 5 Hz for West Seattle relative to Tertiary rock. These values are approximately 30% lower than amplification in the Duwamish Valley on artificial fill, but significantly higher than the calculated range of 2 to 2.5 below 5 Hz for the till-covered hills east of downtown Seattle. Although spectral amplitudes are only 30% higher in the Duwamish Valley compared to West Seattle, the duration of long-period ground motion is significantly greater on the artificial fill sites. Using a three-dimensional displacement response spectrum measure that includes the effects of ground-motion duration, values in the Duwamish Valley are 2 to 3 times greater than West Seattle. These calculations and estimates of site response as a function of receiver azimuth point out the importance of trapped surface-wave energy within the shallow, low-velocity, sedimentary layers of the Duwamish Valley. One-dimensional velocity models yield spectral amplification factors close to the observations for till sites east of downtown Seattle and the Duwamish Valley, but underpredict amplifications by a factor of 2 in West Seattle. A two-dimensional finite-difference model does equally well for the till sites and the Duwamish Valley and also yields duration estimates consistent with the observations for the Duwamish Valley. The two-dimensional model, however, still underpredicts amplification in West Seattle by up to a factor of 2. This discrepancy is attributed to 3D effects, including basin-edge-induced surface waves and basin-geometry-focusing effects, caused by the proximity of the Seattle thrust fault

  12. Death Valley California as seen from STS-59

    NASA Image and Video Library

    1994-04-13

    STS059-86-059 (9-20 April 1994) --- This oblique handheld Hasselblad 70mm photo shows Death Valley, near California's border with Nevada. The valley -- the central feature of Death Valley National Monument -- extends north to south for some 140 miles (225 kilometers). Hemmed in to the east by the Amargosa Range and to the west by the Panamints, its width varies from 5 to 15 miles (8 to 24 kilometers). Using Spaceborne Imaging Radar (SIR-C) and X-band Synthetic Aperture Radar (X-SAR) onboard the Space Shuttle Endeavour, the crew was able to record a great deal of data on this and other sites, as part of NASA's Mission to Planet Earth.

  13. Climatology of atmospheric PM10 concentration in the Po Valley

    NASA Astrophysics Data System (ADS)

    Bigi, A.; Ghermandi, G.

    2014-01-01

    The limits to atmospheric pollutant concentration set by the European Commission provide a challenging target for the municipalities in the Po Valley, because of the characteristic climatic conditions and high population density of this region. In order to assess climatology and trends in the concentration of atmospheric particles in the Po Valley, a dataset of PM10 data from 41 sites across the Po Valley have been analysed, including both traffic and background sites (either urban, suburban or rural). Of these 41 sites, 18 with 10 yr or longer record have been analysed for long term trend in de-seasonalized monthly means, in annual quantiles and in monthly frequency distribution. A widespread significant decreasing trend has been observed at most sites, up to few percent per year, by Generalised Least Square and Theil-Sen method. All 41 sites have been tested for significant weekly periodicity by Kruskal-Wallis test for mean anomalies and by Wilcoxon test for weekend effect magnitude. A significant weekly periodicity has been observed for most PM10 series, particularly in summer and ascribed mainly to anthropic particulate emissions. A cluster analysis has been applied in order to highlight stations sharing similar pollution conditions over the reference period. Five clusters have been found, two gathering the metropolitan areas of Torino and Milano and their respective nearby sites and the other three clusters gathering north-east, north-west and central Po Valley sites respectively. Finally the observed trends in atmospheric PM10 have been compared to trends in provincial emissions of particulates and PM precursors, and analysed along with data on vehicular fleet age, composition and fuel sales. Significant basin-wide drop in emissions occurred for gaseous pollutants, contrarily to emissions of PM10 and PM2.5, whose drop resulted low and restricted to few provinces. It is not clear whether the decrease for only gaseous emissions is sufficient to explain the

  14. Subsurface Salts in Antarctic Dry Valley Soils

    NASA Technical Reports Server (NTRS)

    Englert, P.; Bishop, J. L.; Gibson, E. K.; Koeberl, C.

    2013-01-01

    The distribution of water-soluble ions, major and minor elements, and other parameters were examined to determine the extent and effects of chemical weathering on cold desert soils. Patterns at the study sites support theories of multiple salt forming processes, including marine aerosols and chemical weathering of mafic minerals. Periodic solar-mediated ionization of atmospheric nitrogen might also produce high nitrate concentrations found in older sediments. Chemical weathering, however, was the major contributor of salts in Antarctic Dry Valleys. The Antarctic Dry Valleys represent a unique analog for Mars, as they are extremely cold and dry desert environments. Similarities in the climate, surface geology, and chemical properties of the Dry Valleys to that of Mars imply the possible presence of these soil formation mechanisms on Mars, other planets and icy satellites.

  15. The Valley Forge Encampment: Epic on the Schuylkill.

    ERIC Educational Resources Information Center

    Trussell, John B. B., Jr.

    Valley Forge, outside Philadelphia (Pennsylvania), has long been recognized as the site of a great victory of the human spirit. Eleven thousand men including Blacks and Indians resided there during the winter of 1777-78 and triumphed over cold, starvation, nakedness, disease, and uncertainty. The encampment site was unprepared for the tattered,…

  16. Strong ground motion in the Kathmandu Valley during the 2015 Gorkha, Nepal, earthquake

    NASA Astrophysics Data System (ADS)

    Takai, Nobuo; Shigefuji, Michiko; Rajaure, Sudhir; Bijukchhen, Subeg; Ichiyanagi, Masayoshi; Dhital, Megh Raj; Sasatani, Tsutomu

    2016-01-01

    On 25 April 2015, a large earthquake of Mw 7.8 occurred along the Main Himalayan Thrust fault in central Nepal. It was caused by a collision of the Indian Plate beneath the Eurasian Plate. The epicenter was near the Gorkha region, 80 km northwest of Kathmandu, and the rupture propagated toward east from the epicentral region passing through the sediment-filled Kathmandu Valley. This event resulted in over 8000 fatalities, mostly in Kathmandu and the adjacent districts. We succeeded in observing strong ground motions at our four observation sites (one rock site and three sedimentary sites) in the Kathmandu Valley during this devastating earthquake. While the observed peak ground acceleration values were smaller than the predicted ones that were derived from the use of a ground motion prediction equation, the observed peak ground velocity values were slightly larger than the predicted ones. The ground velocities observed at the rock site (KTP) showed a simple velocity pulse, resulting in monotonic-step displacements associated with the permanent tectonic offset. The vertical ground velocities observed at the sedimentary sites had the same pulse motions that were observed at the rock site. In contrast, the horizontal ground velocities as well as accelerations observed at three sedimentary sites showed long duration with conspicuous long-period oscillations, due to the valley response. The horizontal valley response was characterized by large amplification (about 10) and prolonged oscillations. However, the predominant period and envelope shape of their oscillations differed from site to site, indicating a complicated basin structure. Finally, on the basis of the velocity response spectra, we show that the horizontal long-period oscillations on the sedimentary sites had enough destructive power to damage high-rise buildings with natural periods of 3 to 5 s.

  17. A comparison of avian communities and habitat characteristics in floodplain forests associated with valley plugs and unchannelized streams

    USGS Publications Warehouse

    Pierce, Aaron R.; King, Sammy L.

    2011-01-01

    Channelization of streams associated with floodplain forested wetlands has occurred extensively throughout the world and specifically in the southeastern United States. Channelization of fluvial systems alters the hydrologic and sedimentation processes that sustain these systems. In western Tennessee, channelization and past land-use practices have caused drastic geomorphic and hydrologic changes, resulting in altered habitat conditions that may affect avian communities. The objective of this study was to determine if there were differences in avian communities utilizing floodplain forests along unchannelized streams compared to channelized streams with valley plugs, areas where sediment has completely filled the channel. During point count surveys, 58 bird species were observed at unchannelized sites and 60 species were observed at valley plug sites. Species associated with baldcypress-tupelo (Taxodium-Nyssa) swamps (e.g. Great Egret (Ardea albus) and Black-crowned Night Heron (Nycticorax nycticorax)) and mature hardwood forests with open midstories (e.g. Eastern Wood-Pewee (Contopus virens), Yellow-throated Vireo (Vireo flavifrons), Cerulean Warbler (Dendroica cerulea) and Scarlet Tanager (Piranga olivacea)) were either only found at unchannelized sites or were more abundant at unchannelized sites. Conversely, species associated with open and early successional habitats (e.g. Tree Swallow (Tachycineta bicolor), Northern Mockingbird (Mimus polyglottos) and Blue Grosbeak (Passerina caerulea)) were either only found at valley plug sites or were more abundant at valley plug sites. Results of habitat modelling suggest that the habitat characteristics of floodplain forests at unchannelized sites are more suitable for Neotropical migrant bird species of conservation concern in the region than at valley plug sites. This study, in combination with previous research, demonstrates the ecological impacts of valley plugs span across abiotic and biotic processes and tropic

  18. Extinction of water plants in the Hula Valley: Evidence for climate change.

    PubMed

    Melamed, Yoel; Kislev, Mordechai; Weiss, Ehud; Simchoni, Orit

    2011-04-01

    We describe two events of water plant extinction in the Hula Valley, northern Israel: the ancient, natural extinction of 3 out of 14 extinct species at Gesher Benot Ya'aqov, which occurred some 800-700 k.yr., and an anthropogenic, near contemporary extinction of seven species in the artificial drainage of the Hula Lake in the 1950s. We conclude that the considerable fraction of water plants that disappeared from the Hula Valley in the Early-Middle Pleistocene was the result of habitat desiccation and not global warming. Thus, there is evidence that the hominins who lived in the Hula Valley inhabited a comparatively dry place. The disappearance of water plant species was partially the result of reduced seed dispersal by birds (ornitochory) as a result of the shrinkage of water bodies and their number along the Rift Valley. We suggest that the disappearance of a group of rare, local water plants can be used as an indicator of climate drying and impacts on the local vegetation. Copyright © 2010 Elsevier Ltd. All rights reserved.

  19. Climate controls on valley fever incidence in Kern County, California

    NASA Astrophysics Data System (ADS)

    Zender, Charles S.; Talamantes, Jorge

    2006-01-01

    Coccidiodomycosis (valley fever) is a systemic infection caused by inhalation of airborne spores from Coccidioides immitis, a soil-dwelling fungus found in the southwestern United States, parts of Mexico, and Central and South America. Dust storms help disperse C. immitis so risk factors for valley fever include conditions favorable for fungal growth (moist, warm soil) and for aeolian soil erosion (dry soil and strong winds). Here, we analyze and inter-compare the seasonal and inter-annual behavior of valley fever incidence and climate risk factors for the period 1980-2002 in Kern County, California, the US county with highest reported incidence. We find weak but statistically significant links between disease incidence and antecedent climate conditions. Precipitation anomalies 8 and 20 months antecedent explain only up to 4% of monthly variability in subsequent valley fever incidence during the 23 year period tested. This is consistent with previous studies suggesting that C. immitis tolerates hot, dry periods better than competing soil organisms and, as a result, thrives during wet periods following droughts. Furthermore, the relatively small correlation with climate suggests that the causes of valley fever in Kern County could be largely anthropogenic. Seasonal climate predictors of valley fever in Kern County are similar to, but much weaker than, those in Arizona, where previous studies find precipitation explains up to 75% of incidence. Causes for this discrepancy are not yet understood. Higher resolution temporal and spatial monitoring of soil conditions could improve our understanding of climatic antecedents of severe epidemics.

  20. Spin- and valley-polarized one-way Klein tunneling in photonic topological insulators.

    PubMed

    Ni, Xiang; Purtseladze, David; Smirnova, Daria A; Slobozhanyuk, Alexey; Alù, Andrea; Khanikaev, Alexander B

    2018-05-01

    Recent advances in condensed matter physics have shown that the spin degree of freedom of electrons can be efficiently exploited in the emergent field of spintronics, offering unique opportunities for efficient data transfer, computing, and storage ( 1 - 3 ). These concepts have been inspiring analogous approaches in photonics, where the manipulation of an artificially engineered pseudospin degree of freedom can be enabled by synthetic gauge fields acting on light ( 4 - 6 ). The ability to control these degrees of freedom significantly expands the landscape of available optical responses, which may revolutionize optical computing and the basic means of controlling light in photonic devices across the entire electromagnetic spectrum. We demonstrate a new class of photonic systems, described by effective Hamiltonians in which competing synthetic gauge fields, engineered in pseudospin, chirality/sublattice, and valley subspaces, result in bandgap opening at one of the valleys, whereas the other valley exhibits Dirac-like conical dispersion. We show that this effective response has marked implications on photon transport, among which are as follows: (i) a robust pseudospin- and valley-polarized one-way Klein tunneling and (ii) topological edge states that coexist within the Dirac continuum for opposite valley and pseudospin polarizations. These phenomena offer new ways to control light in photonics, in particular, for on-chip optical isolation, filtering, and wave-division multiplexing by selective action on their pseudospin and valley degrees of freedom.

  1. Simulation of tracer dispersion from elevated and surface releases in complex terrain

    NASA Astrophysics Data System (ADS)

    Hernández, J. F.; Cremades, L.; Baldasano, J. M.

    A new version of an advanced mesoscale dispersion modeling system for simulating passive air pollutant dispersion in the real atmospheric planetary boundary layer (PBL), is presented. The system comprises a diagnostic mass-consistent meteorological model and a Lagrangian particle dispersion model (LADISMO). The former version of LADISMO, developed according to Zannetti (Air pollution modelling, 1990), was based on the Monte Carlo technique and included calculation of higher-order moments of vertical random forcing for convective conditions. Its ability to simulate complex flow dispersion has been stated in a previous paper (Hernández et al. 1995, Atmospheric Environment, 29A, 1331-1341). The new version follows Thomson's scheme (1984, Q. Jl Roy. Met. Soc.110, 1107-1120). It is also based on Langevin equation and follows the ideas given by Brusasca et al. (1992, Atmospheric Environment26A, 707-723) and Anfossi et al. (1992, Nuovo Cemento 15c, 139-158). The model is used to simulate the dispersion and predict the ground level concentration (g.l.c.) of a tracer (SF 6) released from both an elevated source ( case a) and a ground level source ( case b) in a highly complex mountainous terrain during neutral and synoptically dominated conditions ( case a) and light and apparently stable conditions ( case b). The last case is considered as being a specially difficult task to simulate. In fact, few works have reported situations with valley drainage flows in complex terrains and real stable atmospheric conditions with weak winds. The model assumes that nearly calm situations associated to strong stability and air stagnation, make the lowest layers of PBL poorly diffusive (Brusasca et al., 1992, Atmospheric Environment26A, 707-723). Model results are verified against experimental data from Guardo-90 tracer experiments, an intensive field campaign conducted in the Carrion river valley (Northern Spain) to study atmospheric diffusion within a steep walled valley in mountainous

  2. Hematology and plasma biochemistry values for the giant garter snake (Thamnophis gigas) and valley garter snake (Thamnophis sirtalis fitchi) in the Central Valley of California.

    PubMed

    Wack, Raymund F; Hansen, Eric; Small, Marilyn; Poppenga, Robert; Bunn, David; Johnson, Christine K

    2012-04-01

    Hematology and plasma biochemistry parameters are useful in the assessment and management of threatened and endangered species. Although reference ranges are readily available for many mammalian species, reference ranges for snakes are lacking for most species. We determined hematology and plasma biochemistry reference ranges for giant garter snakes (Thamnophis gigas) and valley garter snakes (Thamnophis sirtalis fitchi) living in four management areas in the Central Valley of California. White blood cell, heterophil, lymphocyte, and azurophil counts in giant garter snakes were approximately twice the values of valley garter snakes. Statistically significant differences in aspartate aminotransferase, globulin, and potassium between the two species did not appear clinically significant. No significant differences were found in the measured parameters between male and female giant garter snakes. Some differences were found among collection sites. These reference ranges provide baseline data for comparisons over time and between collection sites.

  3. Temporal and geographic patterns of kinship structure in common dolphins (Delphinus delphis) suggest site fidelity and female-biased long-distance dispersal.

    PubMed

    Ball, Laura; Shreves, Kypher; Pilot, Małgorzata; Moura, André E

    2017-01-01

    Social structure plays a crucial role in determining a species' dispersal patterns and genetic structure. Cetaceans show a diversity of social and mating systems, but their effects on dispersal and genetic structure are not well known, in part because of technical difficulties in obtaining robust observational data. Here, we combine genetic profiling and GIS analysis to identify patterns of kin distribution over time and space, to infer mating structure and dispersal patterns in short-beaked common dolphins ( Delphinus delphis ). This species is highly social, and exhibits weak spatial genetic structure in the Northeast Atlantic and Mediterranean Sea, thought to result from fluid social structure and low levels of site fidelity. We found that although sampled groups were not composed of closely related individuals, close kin were frequently found in the same geographic location over several years. Our results suggest that common dolphin exhibits some level of site fidelity, which could be explained by foraging for temporally varying prey resource in areas familiar to individuals. Dispersal from natal area likely involves long-distance movements of females, as males are found more frequently than females in the same locations as their close kin. Long-distance dispersal may explain the near panmixia observed in this species. By analysing individuals sampled in the same geographic location over multiple years, we avoid caveats associated with divergence-based methods of inferring sex-biased dispersal. We thus provide a unique perspective on this species' social structure and dispersal behaviour, and how it relates to the observed low levels of population genetic structure in European waters. Movement patterns and social interactions are aspects of wild animal's behaviour important for understanding their ecology. However, tracking these behaviours directly can be very challenging in wide-ranging species such as whales and dolphins. In this study, we used genetic

  4. Glade Valley School: 1909-1985.

    ERIC Educational Resources Information Center

    Dickson, Kay Reita

    This book is a comprehensive history of the Glade Valley School in Allegheny County, North Carolina. It is filled with letters, newspaper reports, first-hand accounts, and photographs that trace the lives of its students and faculty back to opening day in January 1911. The school's site was chosen in 1909 and was deemed favorable because it was…

  5. The geochemistry of groundwater resources in the Jordan Valley: The impact of the Rift Valley brines

    USGS Publications Warehouse

    Farber, E.; Vengosh, A.; Gavrieli, I.; Marie, Amarisa; Bullen, T.D.; Mayer, B.; Polak, A.; Shavit, U.

    2007-01-01

    The chemical composition of groundwater in the Jordan Valley, along the section between the Sea of Galilee and the Dead Sea, is investigated in order to evaluate the origin of the groundwater resources and, in particular, to elucidate the role of deep brines on the chemical composition of the regional groundwater resources in the Jordan Valley. Samples were collected from shallow groundwater in research boreholes on two sites in the northern and southern parts of the Jordan Valley, adjacent to the Jordan River. Data is also compiled from previous published studies. Geochemical data (e.g., Br/Cl, Na/Cl and SO4/Cl ratios) and B, O, Sr and S isotopic compositions are used to define groundwater groups, to map their distribution in the Jordan valley, and to evaluate their origin. The combined geochemical tools enabled the delineation of three major sources of solutes that differentially affect the quality of groundwater in the Jordan Valley: (1) flow and mixing with hypersaline brines with high Br/Cl (>2 ?? 10-3) and low Na/Cl (<0.8) ratios; (2) dissolution of highly soluble salts (e.g., halite, gypsum) in the host sediments resulting in typically lower Br/Cl signal (<2 ?? 10-3); and (3) recharge of anthropogenic effluents, primarily derived from evaporated agricultural return flow that has interacted (e.g., base-exchange reactions) with the overlying soil. It is shown that shallow saline groundwaters influenced by brine mixing exhibit a north-south variation in their Br/Cl and Na/Cl ratios. This chemical trend was observed also in hypersaline brines in the Jordan valley, which suggests a local mixing process between the water bodies. ?? 2007 Elsevier Ltd. All rights reserved.

  6. Deep Resistivity Structure of Mid Valley, Nevada Test Site, Nevada

    USGS Publications Warehouse

    Wallin, Erin L.; Rodriguez, Brian D.; Williams, Jackie M.

    2009-01-01

    -Tertiary confining units. In particular, a major goal was to define the extent of the upper clastic confining unit (UCCU). The UCCU is composed of late Devonian to Mississippian siliciclastic rocks assigned to the Eleana Formation and Chainman Shale (National Security Technologies, 2007). The UCCU underlies the Yucca Flat area and extends southwestward toward Shoshone Mountain, westward toward Buckboard Mesa, and northwestward toward Rainier Mesa. Late in 2005 we collected data at an additional 14 MT stations in Mid Valley, CP Hills, and northern Yucca Flat. That work was done to better determine the extent and thickness of the UCCU near the boundary between the southeastern RM-SM CAU and the southwestern YF CAU, and also in the northern YF CAU. The MT data have been released in a separate U.S. Geological Survey report (Williams and others, 2007). The Nevada Test Site magnetotelluric data interpretation presented in this report includes the results of detailed two-dimensional (2-D) resistivity modeling for each profile and inferences on the three-dimensional (3-D) character of the geology within the region.

  7. Flow structure and turbulence characteristics of the daytime atmosphere in a steep and narrow Alpine valley

    NASA Astrophysics Data System (ADS)

    Weigel, Andreas P.; Rotach, Mathias W.

    2004-10-01

    Aircraft measurements, radio soundings and sonic data--obtained during the MAP-Riviera field campaign in autumn 1999 in southern Switzerland--are used to investigate the flow structure, temperature profiles and turbulence characteristics of the atmosphere in a steep and narrow Alpine valley under convective conditions. On all predominantly sunny days of the intensive observation periods, a pronounced valley-wind system develops. In the southern half of the valley, the daily up-valley winds have a jet-like structure and are shifted towards the eastern slope. These up-valley winds advect potentially colder air, a process which appears to be balanced by vertical warm air advection from above. The profiles of potential temperature show that, with the onset of up-valley winds, the mixed layer consistently stops growing or--on days with very strong up-valley winds--even stabilizes almost throughout the entire valley atmosphere. This is probably due to a pronounced secondary circulation in the southern part of the valley, which induces advection of warm air from above. The secondary circulation appears to be a consequence of sharp curvature in the along-valley topography. Turbulence variables are calculated from flight legs in the along-valley direction. Turbulent kinetic energy (TKE) scales surprisingly well (i) if a TKE criterion (TKE > 0.5 m2s-2) is employed as a definition of the boundary layer height and (ii) if the 'surface fluxes'--which exhibit a substantial spatial variability--from the slope sites are used rather than those from directly beneath the profile considered. Significant site-to-site differences in incoming solar radiation seem to be the reason for this characteristic behaviour. Profiles of momentum flux--scaled with a surface friction velocity--reveal more scatter than the TKE profiles, but still show a consistent behaviour. A surprisingly strong shear in the cross-valley direction can be observed and is probably a result of the secondary circulation.

  8. Mechanisms Responsible for the Observed Thermodynamic Structure in a Convective Boundary Layer Over the Hudson Valley of New York State

    NASA Astrophysics Data System (ADS)

    Freedman, Jeffrey M.; Fitzjarrald, David R.

    2017-02-01

    We examine cases of a regional elevated mixed layer (EML) observed during the Hudson Valley Ambient Meteorology Study (HVAMS) conducted in New York State, USA in 2003. Previously observed EMLs referred to topographic domains on scales of 105 -106 km2 . Here, we present observational evidence of the mechanisms responsible for the development and maintenance of regional EMLs overlying a valley-based convective boundary layer (CBL) on much smaller spatial scales (<5000 km2) . Using observations from aircraft-based, balloon-based, and surface-based platforms deployed during the HVAMS, we show that cross-valley horizontal advection, along-valley channelling, and fog-induced cold-air pooling are responsible for the formation and maintenance of the EML and valley-CBL coupling over New York State's Hudson Valley. The upper layer stability of the overlying EML constrains growth of the valley CBL, and this has important implications for air dispersion, aviation interests, and fog forecasting.

  9. Statistical modeling of valley fever data in Kern County, California

    NASA Astrophysics Data System (ADS)

    Talamantes, Jorge; Behseta, Sam; Zender, Charles S.

    2007-03-01

    Coccidioidomycosis (valley fever) is a fungal infection found in the southwestern US, northern Mexico, and some places in Central and South America. The fungus that causes it ( Coccidioides immitis) is normally soil-dwelling but, if disturbed, becomes air-borne and infects the host when its spores are inhaled. It is thus natural to surmise that weather conditions that foster the growth and dispersal of the fungus must have an effect on the number of cases in the endemic areas. We present here an attempt at the modeling of valley fever incidence in Kern County, California, by the implementation of a generalized auto regressive moving average (GARMA) model. We show that the number of valley fever cases can be predicted mainly by considering only the previous history of incidence rates in the county. The inclusion of weather-related time sequences improves the model only to a relatively minor extent. This suggests that fluctuations of incidence rates (about a seasonally varying background value) are related to biological and/or anthropogenic reasons, and not so much to weather anomalies.

  10. Boxer blurring the lines in Ward Valley debate

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Newman, P.

    1994-04-05

    This article concerns the controversy over the siting of Ward Valley, a proposed low-level nuclear waste depository in California. The author contends that certain politicians and environmental groups have misrepresented the facts in their opposition to the site. In particular, an accusation about withholding information about the amount of Pu-239 to be stored at the site is false, since that information is available in the public record. Other misrepresentations are presented and discussed.

  11. Quaternary Geochronology, Paleontology, and Archaeology of the Upper San Pedro River Valley, Sonora, Mexico

    NASA Astrophysics Data System (ADS)

    Gaines, E. P.

    2013-12-01

    This poster presents the results of multi-disciplinary investigations of the preservation and extent of Quaternary fossil-bearing strata in the San Pedro River Valley in Sonora, Mexico. Geologic deposits in the portions of the San Pedro Valley in southern Arizona contain one of the best late Cenozoic fossil records known in North America and the best record of early humans and extinct mammals on the continent. The basin in the U.S. is one of the type locations for the Blancan Land Mammal Age. Hemiphilian and Irvingtonian fossils are common. Rancholabrean remains are widespread. Strata in the valley adjacent to the international border with Mexico have yielded the densest concentration of archaeological mammoth-kill sites known in the western hemisphere. Despite more than 60 years of research in the U.S., however, and the fact that over one third of the San Pedro River lies south of the international boundary, little has been known about the late Cenozoic geology of the valley in Mexico. The study reported here utilized extensive field survey, archaeological documentation, paleontological excavations, stratigraphic mapping and alluvial geochronology to determine the nature and extent of Quaternary fossil-bearing deposits in the portions of the San Pedro Valley in Sonora, Mexico. The results demonstrate that the Plio-Pleistocene fossil -bearing formations known from the valley in Arizona extend into the uppermost reaches of the valley in Mexico. Several new fossil sites were discovered that yielded the remains of Camelids, Equus, Mammuthus, and other Proboscidean species. Late Pleistocene archaeological remains were found on the surface of the surrounding uplands. AMS radiocarbon dating demonstrates the widespread preservation of middle- to late- Holocene deposits. However, the late Pleistocene deposits that contain the archaeological mammoth-kill sites in Arizona are absent in the valley in Mexico, and are now known to be restricted to relatively small portions of

  12. Spin- and valley-polarized one-way Klein tunneling in photonic topological insulators

    PubMed Central

    Slobozhanyuk, Alexey

    2018-01-01

    Recent advances in condensed matter physics have shown that the spin degree of freedom of electrons can be efficiently exploited in the emergent field of spintronics, offering unique opportunities for efficient data transfer, computing, and storage (1–3). These concepts have been inspiring analogous approaches in photonics, where the manipulation of an artificially engineered pseudospin degree of freedom can be enabled by synthetic gauge fields acting on light (4–6). The ability to control these degrees of freedom significantly expands the landscape of available optical responses, which may revolutionize optical computing and the basic means of controlling light in photonic devices across the entire electromagnetic spectrum. We demonstrate a new class of photonic systems, described by effective Hamiltonians in which competing synthetic gauge fields, engineered in pseudospin, chirality/sublattice, and valley subspaces, result in bandgap opening at one of the valleys, whereas the other valley exhibits Dirac-like conical dispersion. We show that this effective response has marked implications on photon transport, among which are as follows: (i) a robust pseudospin- and valley-polarized one-way Klein tunneling and (ii) topological edge states that coexist within the Dirac continuum for opposite valley and pseudospin polarizations. These phenomena offer new ways to control light in photonics, in particular, for on-chip optical isolation, filtering, and wave-division multiplexing by selective action on their pseudospin and valley degrees of freedom. PMID:29756032

  13. GPS measurements of strain accumulation across the Imperial Valley, California: 1986-1989

    NASA Technical Reports Server (NTRS)

    Larsen, Shawn; Reilinger, Robert

    1989-01-01

    The Global Positioning System (GPS) data collected in southern California from 1986 to 1989 indicate considerable strain accumulation across the Imperial Valley. Displacements are computed at 29 stations in and near the valley from 1986 to 1988, and at 11 sites from 1988 to 1989. The earlier measurements indicate 5.9 +/- 1.0 cm/yr right-lateral differential velocity across the valley, although the data are heavily influenced by the 1987 Superstition Hills earthquake sequence. Some measurements, especially the east-trending displacements, are suspects for large errors. The 1988 to 1989 GPS displacements are best modeled by 5.2 +/- 0.9 cm/yr of valley crossing deformation, but rates calculated from conventional geodetic measurements (3.4 to 4.3 cm/yr) fit the data nearly as well. There is evidence from GPS and Very Long Base Interferometry (VLBI) observations that the present slip rate along the southern San Andreas fault is smaller than the long-term geologic estimate, suggesting a lower earthquake potential than is currently assumed. Correspondingly, a higher earthquake potential is indicated for the San Jacinto fault. The Imperial Valley GPS sites form part of a 183 station network in southern California and northern Baja California, which spans a cross-section of the North American-Pacific plate boundary.

  14. Enhanced dispersion of epicardial activation-recovery intervals at sites of histological inhomogeneity during regional cardiac ischaemia and reperfusion

    PubMed Central

    Gottwald, E; Gottwald, M; Dhein, S

    1998-01-01

    Objective—To examine how epicardial activation and repolarisation patterns change in the course of ischaemia, and how these changes are related to the underlying histological structures.
Methods—Langendorff perfused isolated rabbit hearts were submitted to 30 minutes of left anterior descending coronary artery occlusion followed by 30 minutes of reperfusion. A 256 channel epicardial map was plotted during the various experimental phases. Activation time points were determined as t(dU/dtmin) and repolarisation time points as t(dU/dtmax). From these data the local activation-recovery interval (ARI), its dispersion (SD of ARI), and the geometry of the activation spread could be analysed. After the experiments the hearts were processed histologically and the mapping data were projected onto histological slides.
Results—There was elevation of the ST segment within the occluded area, which recovered during reperfusion. Within this area, ARI was significantly shortened and its dispersion was maximally enhanced. The enhancement of dispersion was pronounced at sites of histological inhomogeneity like fat, connective tissue, or vessels. There was also a change in the preferential direction of activation spread within the occluded zone with a marked transverse propagation of the activation wavefront, whereas under normal conditions the activation followed the longitudinal fibre axis. In addition, the total activation time in the occluded area was significantly prolonged.
Conclusions—Ischaemia alters the local activation pattern with enhanced dispersion, especially at sites of histological irregularity, transverse shift of the activation waves, and a general slowing of conduction, which may explain the increased susceptibility to arrhythmia in hearts with enhanced histological irregularities—for example, an infarct or in multi-infarcted hearts, or after myocarditis. 

 Keywords: dispersion;  epicardial activation-recovery interval;  ischaemia PMID

  15. Possible Analogs for Small Valleys on Mars at the Haughton Impact Crater Site, Devon Island, Canadian High Arctic

    NASA Technical Reports Server (NTRS)

    Lee, P.; Rice, J. W., Jr.; Bunch, Theodore E.; Grieve, R. A. F.; McKay, C. P.; Schutt, J. W.; Zent, A. P.

    1999-01-01

    Small valleys are perhaps the clearest evidence for an aqueous past on Mars. While small valley formation has occurred even in Amazonian times, most small valleys on Mars are associated with the heavily cratered Noachian terrains. Martian small valleys are often cited as evidence for a putative warmer and wetter climate on Early Mars in which rain and subsequent surface runoff would have acted as significant erosional agents, but the morphology of many small valleys has at the same time been recognized as having several unusual characteristics, making their origin still enigmatic and climatic inferences from them uncertain. Meanwhile, martian climate modeling efforts have been facing difficulties over the past decades with the problem of making the early martian climate warm enough to achieve temperature above 273 K to allow rainfall and the sustained flow of liquid water at the martian surface.

  16. Geoarchaeology of Paalliq 1 Valley, Kuuvik Bay, Nunavik (Québec)

    NASA Astrophysics Data System (ADS)

    Barbel, Héloïse; Bhiry, Najat; Todisco, Dominique

    2017-04-01

    Given its cultural interest for the community of Akulivik, the Kuuvik Bay, Nunavik (Québec) presents an excellent opportunity for archaeologists, geoarchaeologists and paleo-environmentalists to study the significant archaeological and environmental features of Kuuvik Bay. In this research project, we seek to expand our knowledge of the human-environment relationship in Nunavik in the context of climate change. Our focus is on the changes in Dorset and Thule land occupation in the environmental context (especially during the winter) at the Kuuvik Bay which is located about 100 km north from Akulivik,. Intra-site and extra-site geoarchaeological studies have been performed at Structure 10 on the Kuuvik 1516 site as well as in the valley in which it is situated (Paalliq 1 Valley). Many of the multifamily subterranean sod houses recorded at the Kuuvik 1516 site were the first to be inventoried at Nunavik. They had already been observed in Labrador (Eastern Canada), but the modalities of their appearance from the 17th Century continue to be studied. Multifactorial climatic and historical factors have been identified. Our research focuses on the following question: What factors contributed to such an important gathering of archaeological structures in the same site and to the appearance of multifamily subterranean sod houses? Combining extra-site and intra-site approaches, this geoarchaeological study aims to: 1) document the geomorphological context in which the Dorset and Thule occupied the Paalliq 1 Valley, especially in relation to postglacial marine regression (as linked to isostatic rebound), 2) identify processes of cultural and natural formation (biopedologic and sedimentary), and 3) identify the eventual reuse or reorganization phases of Dorset sites by the Thule.

  17. Hydrogeologic and geochemical characterization of groundwater resources in Rush Valley, Tooele County, Utah

    USGS Publications Warehouse

    Gardner, Philip M.; Kirby, Stefan

    2011-01-01

    generally flows from the higher altitude recharge areas toward two distinct valley-bottom discharge areas: one in the vicinity of Rush Lake in northern Rush Valley and the other located west and north of Vernon. Average annual discharge from the Rush Valley groundwater basin is estimated to be about 43,000 acre-feet. Most discharge occurs as evapotranspiration in the valley lowlands, as discharge to springs and streams, and as withdrawal from wells. Subsurface discharge outflow to Tooele and Cedar Valleys makes up only a small fraction of natural discharge.Groundwater samples were collected from 25 sites (24 wells and one spring) for geochemical analysis. Dissolved-solids concentrations in water from these sites ranged from 181 to 1,590 milligrams per liter. Samples from seven wells contained arsenic concentrations that exceed the Environmental Protection Agency Maximum Contaminant Level of 10 micrograms per liter. The highest arsenic levels are found north of Vernon and in southeastern Rush Valley. Stable-isotope ratios of oxygen and deuterium, along with dissolved-gas recharge temperatures, indicate that nearly all modern groundwater is meteoric and derived from the infiltration of high altitude precipitation in the mountains. These data are consistent with recharge estimates made using a Basin Characterization Model of net infiltration that shows nearly all recharge occurring as infiltration of precipitation and snowmelt within the mountains surrounding Rush Valley. Tritium concentrations between 0.4 and 10 tritium units indicate the presence of modern (less than 60 years old) groundwater at 7 of the 25 sample sites. Apparent 3H/3He ages, calculated for six of these sites, range from 3 to 35 years. Adjusted minimum radiocarbon ages of premodern water samples range from about 1,600 to 42,000 years with samples from 11 of 13 sites being more than 11,000 years. These data help to identify areas where modern groundwater is circulating through the hydrologic system on time

  18. Riparian valley oak (Quercus lobata) forest restoration on the middle Sacramento River, California

    Treesearch

    F. Thomas Griggs; Gregory H. Golet

    2002-01-01

    In 1989 The Nature Conservancy initiated a riparian horticultural restoration program on the floodplain of the middle Sacramento River, California. At nearly all restoration sites Valley oak (Quercus lobata Nee) comprised a major component of the planting design. Valley oaks are a keystone tree species of lowland floodplain habitats in California...

  19. Simulation of Tracer Concentration Data in the Brush Creek Drainage Flow Using an Integrated Puff Model.

    NASA Astrophysics Data System (ADS)

    Rao, K. Shankar; Eckman, Richard M.; Hosker, Rayford P., Jr.

    1989-07-01

    During the 1984 ASCOT field study in Brush Creek Valley, two perfluorocarbon tracers were released into the nocturnal drainage flow at two different heights. The resulting surface concentrations were sampled at 90 sites, and vertical concentration profiles at 11 sites. These detailed tracer measurements provide a valuable dataset for developing and testing models of pollutant transport and dispersion in valleys.In this paper, we present the results of Gaussian puff model simulations of the tracer releases in Brush Creek Valley. The model was modified to account for the restricted lateral dispersion in the valley, and for the gross elevation differences between the release site and the receptors. The variable wind fields needed to transport the puffs were obtained by interpolation between wind profiles measured using tethered balloons at five along-valley sites. Direct turbulence measurements were used to estimate diffusion. Subsidence in the valley flow was included for elevated releases.Two test simulations-covering different nights, tracers, and release heights-were performed. The predicted hourly concentrations were compared with observations at 51 ground-level locations. At most sites, the predicted and observed concentrations agree within a factor of 2 to 6. For the elevated release simulation, the observed mean concentration is 40 pL/L, the predicted mean is 21 pL/L, the correlation coefficient between the observed and predicted concentrations is 0.24, and the index of agreement is 0.46. For the surface release simulation, the observed mean is 85 pL/L, and the predicted mean is 73 pL/L. The correlation coefficient is 0.23, and the index of agreement is 0.42. The results suggest that this modified puff model can be used as a practical tool for simulating pollutant transport and dispersion in deep valleys.

  20. Valley-dependent band structure and valley polarization in periodically modulated graphene

    NASA Astrophysics Data System (ADS)

    Lu, Wei-Tao

    2016-08-01

    The valley-dependent energy band and transport property of graphene under a periodic magnetic-strained field are studied, where the time-reversal symmetry is broken and the valley degeneracy is lifted. The considered superlattice is composed of two different barriers, providing more degrees of freedom for engineering the electronic structure. The electrons near the K and K' valleys are dominated by different effective superlattices. It is found that the energy bands for both valleys are symmetric with respect to ky=-(AM+ξ AS) /4 under the symmetric superlattices. More finite-energy Dirac points, more prominent collimation behavior, and new crossing points are found for K' valley. The degenerate miniband near the K valley splits into two subminibands and produces a new band gap under the asymmetric superlattices. The velocity for the K' valley is greatly renormalized compared with the K valley, and so we can achieve a finite velocity for the K valley while the velocity for the K' valley is zero. Especially, the miniband and band gap could be manipulated independently, leading to an increase of the conductance. The characteristics of the band structure are reflected in the transmission spectra. The Dirac points and the crossing points appear as pronounced peaks in transmission. A remarkable valley polarization is obtained which is robust to the disorder and can be controlled by the strain, the period, and the voltage.

  1. Human Dispersals Along the African Rift Valley in the Late Quaternary

    NASA Astrophysics Data System (ADS)

    Tryon, C. A.; Faith, J. T.; Peppe, D. J.

    2014-12-01

    Climate- and tectonic-driven environmental dynamics of the East African Rift System (EARS) during the Quaternary played an important role in the demographic history of early Homo sapiens, including expansions of modern humans across and out of Africa. Human forager population size, geographic range, and behaviors such as hunting strategies and residential mobility likely varied in response to changes in the local and regional environment. Throughout the Quaternary, floral and faunal change was linked at least in part to variations in moisture availability, temperature, and atmospheric CO2, which in addition to uplift and faulting, contributed to the expansion and contraction of a number of large lakes that served as biogeographic barriers to many taxa. This is particularly clear for the Lake Victoria basin, where biogeographic, geological, and paleontological evidence documents repeated expansion and contraction of the ranges of species in response to lake level and vegetation change. Across much of eastern Africa, the topography of the rift facilitated north-south dispersals, the timing of which may have depended in part on the expansion and contraction of the equatorial forest belt. Dispersal potential likely increased during the more arid periods of the late Quaternary, when the roles of lakes and forests as dispersal barriers was reduced and the extent of low net primary productivity dry grasslands increased, the latter requiring large home ranges for human foragers, conditions suitable for range expansions within H. sapiens.

  2. Bottom currents observed in and around a submarine valley on the continental slope of the northern South China Sea

    NASA Astrophysics Data System (ADS)

    Wu, Lunyu; Xiong, Xuejun; Li, Xiaolong; Shi, Maochong; Guo, Yongqing; Chen, Liang

    2016-12-01

    Bottom currents at about 1000 m depth in and around a submarine valley on the continental slope of the northern South China Sea were studied by a 14-month long experiment from July 2013 to September 2014. The observations reveal that bottom currents are strongly influenced by the topography, being along valley axis or isobaths. Power density spectrum analysis shows that all the currents have significant peaks at diurnal and semi-diurnal frequencies. Diurnal energy is dominant at the open slope site, which is consistent with many previous studies. However, at the site inside the valley the semi-diurnal energy dominates, although the distance between the two sites of observation is quite small (11 km) compared to a typical horizontal first-mode internal tide wavelength (200 km). We found this phenomenon is caused by the focusing of internal waves of certain frequencies in the valley. The inertial peak is found only at the open slope site in the first deployment but missing at the inside valley site and the rest of the deployments. Monthly averaged residual currents reveal that the near-bottom currents on the slope flow southwestward throughout the year except in August and September, 2013, from which we speculate that this is a result of the interaction between a mesoscale eddy and the canyon/sag topography. Currents inside the valley within about 10 mab basically flow along slope and in the layers above the 10 mab the currents are northwestward, that is, from the deep ocean to the shelf. The monthly mean current vectors manifest an Ekman layer-like vertical structure at both sites, which rotate counter-clockwise looking from above.

  3. Changes in biodiversity and ecosystem function downstream from mountaintop removal and valley fill coal mining

    EPA Science Inventory

    Mountaintop removal and valley fill coal mining has altered the physicochemical landscape of the Central Appalachian region in the U.S. Increased specific conductance and levels of component ions downstream from valley fill sites are toxic to aquatic life and can negatively impa...

  4. Are seed and dispersal characteristics of plants capable of predicting colonization of post-mining sites?

    PubMed

    Horáčková, Martina; Řehounková, Klára; Prach, Karel

    2016-07-01

    Seed characteristics play an important role in the colonization and subsequent persistence of species during succession in disturbed sites and thus may contribute to being able to predict restoration success. In the present study, we investigated how various seed characteristics participated in 11 spontaneous successional series running in different mining sites (spoil heaps, extracted sand and sand-gravel pits, extracted peatlands, and stone quarries) in the Czech Republic, Central Europe. Using 1864 samples from 1- to 100-years-old successional stages, we tested whether species optimum along the succession gradient could be predicted using 10 basic species traits connected with diaspores and dispersal. Seed longevity, diaspore mass, endozoochory, and autochory appeared to be the best predictors. The results indicate that seed characteristics can predict to a certain degree spontaneous vegetation succession, i.e., passive restoration, in the mining sites. A screening of species available in the given landscape (regional and local species pools) may help to identify those species which would potentially colonize the disturbed sites. Extensive databases of species traits, nowadays available for the Central European flora, enable such screening.

  5. Geology of the Thaumasia region, Mars: Plateau development, valley origins, and magmatic evolution

    USGS Publications Warehouse

    Dohm, J.M.; Tanaka, K.L.

    1999-01-01

    We have constructed the complex geologic history of the Thaumasia region of Mars on the basis of detailed geologic mapping and relative-age dating of rock units and structure. The Thaumasia plateau dominates the region and consists of high lava plains partly surrounded by rugged highlands, mostly of Noachian and Hesperian age. Long-lived faulting centered near Syria Planum and at lesser sites produced radiating narrow grabens during the Noachian through Early Amazonian and concentric wrinkle ridges during the Late Noachian and Early Hesperian. Fault activity peaked during the Noachian and waned substantially during Late Hesperian and Amazonian time. Volcanism on the Thaumasia plateau was particularly active in comparison with other martian cratered highlands, resulting in fourteen volcanoes and numerous outcrops of smooth, ridged, and lobate plains materials. A particularly extensive set of overlapping lava-flow units was emplaced sequentially from Thaumasia Planum to Syria Planum, spanning from the Late Noachian to the Late Hesperian; lobate flows succeeded smooth flow at the beginning of the Late Hesperian. Deep crustal intrusion and a thickened, buoyant crust may have caused the uplift of the plateau during the Noachian and Early Hesperian, resulting in outward-verging fold-and-thrust plateau margins. This structural style appears similar to that of the young ranges of the Rocky Mountains in the western U.S. Within the plateau, several sites of volcanotectonic activity and valley erosion may be underlain by large and perhaps long-lived magmatic intrusions. One such site occurs at the headland of Warrego Valles. Here, at least two episodes of valley dissection from the Noachian to Early Hesperian occurred during the formation of two nearby rift systems. The site also is a locus of intersection for regional narrow grabens during the Late Noachian and Early Hesperian. However, at the site, such faults diverge or terminate, which suggests that a resistant body of

  6. ANALYSIS OF LOTIC MACROINVERTEBRATE ASSEMBLAGES IN CALIFORNIA'S CENTRAL VALLEY

    EPA Science Inventory

    Using multivariate and cluster analyses, we examined the relaitonships between chemical and physical characteristics and macroinvertebrate assemblages at sites sampled by R-EMAP in California's Central Valley. By contrasting results where community structure was summarized as met...

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

    USGS Publications Warehouse

    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.

  8. Geohydrology of the Antelope Valley Area, California and design for a ground-water-quality monitoring network

    USGS Publications Warehouse

    Duell, L.F.

    1987-01-01

    A basinwide ideal network and an actual network were designed to identify ambient groundwater quality, trends in groundwater quality, and degree of threat from potential pollution sources in Antelope Valley, California. In general, throughout the valley groundwater quality has remained unchanged, and no specific trends are apparent. The main source of groundwater for the valley is generally suitable for domestic, irrigation, and most industrial uses. Water quality data for selected constituents of some network wells and surface-water sites are presented. The ideal network of 77 sites was selected on the basis of site-specific criteria, geohydrology, and current land use (agricultural, residential, and industrial). These sites were used as a guide in the design of the actual network consisting of 44 existing wells. Wells are currently being monitored and were selected whenever possible because of budgetary constraints. Of the remaining ideal sites, 20 have existing wells not part of a current water quality network, and 13 are locations where no wells exist. The methodology used for the selection of sites, constituents monitored, and frequency of analysis will enable network users to make appropriate future changes to the monitoring network. (USGS)

  9. Earthquake Hazard Class Mapping by Parcel in Las Vegas Valley

    NASA Astrophysics Data System (ADS)

    Pancha, A.; Pullammanappallil, S.; Louie, J. N.; Hellmer, W. K.

    2011-12-01

    Clark County, Nevada completed the very first effort in the United States to map earthquake hazard class systematically through an entire urban area. The map is used in development and disaster response planning, in addition to its direct use for building code implementation and enforcement. The County contracted with the Nevada System of Higher Education to classify about 500 square miles including urban Las Vegas Valley, and exurban areas considered for future development. The Parcel Map includes over 10,000 surface-wave array measurements accomplished over three years using Optim's SeisOpt° ReMi measurement and processing techniques adapted for large scale data. These array measurements classify individual parcels on the NEHRP hazard scale. Parallel "blind" tests were conducted at 93 randomly selected sites. The rms difference between the Vs30 values yielded by the blind data and analyses and the Parcel Map analyses is 4.92%. Only six of the blind-test sites showed a difference with a magnitude greater than 10%. We describe a "C+" Class for sites with Class B average velocities but soft surface soil. The measured Parcel Map shows a clearly definable C+ to C boundary on the west side of the Valley. The C to D boundary is much more complex. Using the parcel map in computing shaking in the Valley for scenario earthquakes is crucial for obtaining realistic predictions of ground motions.

  10. Enhanced air dispersion modelling at a typical Chinese nuclear power plant site: Coupling RIMPUFF with two advanced diagnostic wind models.

    PubMed

    Liu, Yun; Li, Hong; Sun, Sida; Fang, Sheng

    2017-09-01

    An enhanced air dispersion modelling scheme is proposed to cope with the building layout and complex terrain of a typical Chinese nuclear power plant (NPP) site. In this modelling, the California Meteorological Model (CALMET) and the Stationary Wind Fit and Turbulence (SWIFT) are coupled with the Risø Mesoscale PUFF model (RIMPUFF) for refined wind field calculation. The near-field diffusion coefficient correction scheme of the Atmospheric Relative Concentrations in the Building Wakes Computer Code (ARCON96) is adopted to characterize dispersion in building arrays. The proposed method is evaluated by a wind tunnel experiment that replicates the typical Chinese NPP site. For both wind speed/direction and air concentration, the enhanced modelling predictions agree well with the observations. The fraction of the predictions within a factor of 2 and 5 of observations exceeds 55% and 82% respectively in the building area and the complex terrain area. This demonstrates the feasibility of the new enhanced modelling for typical Chinese NPP sites. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Plutonium Particle Migration in the Shallow Vadose Zone: The Nevada Test Site as an Analog Site

    NASA Astrophysics Data System (ADS)

    Hunt, J. R.; Smith, D. K.

    2004-12-01

    The upper meter of the vadose zone in desert environments is the horizon where wastes have been released and human exposure is determined through dermal, inhalation, and food uptake pathways. This region is also characterized by numerous coupled processes that determine contaminant transport, including precipitation infiltration, evapotranspiration, daily and annual temperature cycling, dust resuspension, animal burrowing, and geochemical weathering reactions. While there is considerable interest in colloidal transport of minerals, pathogenic organisms, and contaminants in the vadose zone, there are limited field sites where the actual occurrence of contaminant migration can be quantified over the appropriate spatial and temporal scales of interest. At the US Department of Energy Nevada Test Site, there have been numerous releases of radionuclides since the 1950's that have become field-scale tracer tests. One series of tests was the four safety shots conducted in an alluvial valley of Area 11 in the 1950's. These experiments tested the ability of nuclear materials to survive chemical explosions without initiating fission reactions. Four above-ground tests were conducted and they released plutonium and uranium on the desert valley floor with only one of the tests undergoing some fission. Shortly after the tests, the sites were surveyed for radionuclide distribution on the land surface using aerial surveys and with depth. Additional studies were conducted in the 1970's to better understand the fate of plutonium in the desert that included studies of depth distribution and dust resuspension. More recently, plutonium particle distribution in the soil profile was detected using autoradiography. The results to date demonstrate the vertical migration of plutonium particles to depths in excess of 30 cm in this arid vadose zone. While plutonium migration at the Nevada Test Site has been and continues to be a concern, these field experiments have become analog sites for the

  12. Community Response to Concentrating Solar Power in the San Luis Valley: October 9, 2008 - March 31, 2010

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Farhar, B. C.; Hunter, L. M.; Kirkland, T. M.

    2010-06-01

    This report is about the social acceptance of utility-scale concentrating solar power (CSP) plants in the San Luis Valley, approximately 200 miles southwest of Denver, Colorado. The research focused on social factors that may facilitate and impede the adoption and implementation of CSP. During the winter of 2008-2009, interviews were conducted with a purposive sample of 25 CSP-related stakeholders inside and outside the Valley. Interviews focused on the perceived advantages and disadvantages of siting a hypothetical 100-MW CSP facility in the Valley, the level of community support and opposition to CSP development, and related issues, such as transmission. State policymore » recommendations based on the findings include developing education programs for Valley residents, integrating Valley decision makers into an energy-water-land group, providing training for Valley decision makers, offering workforce training, evaluating models of taxation, and forming landholder energy associations. In addition, the SLV could become a laboratory for new approaches to CSP facility and transmission siting decision-making. The author recommends that outside stakeholders address community concerns and engage Valley residents in CSP decisions. Engaging the residents in CSP and transmission decisions, the author says, should take parallel significance with the investment in solar technology.« less

  13. Fort Valley Experimental Forest-A Century of Research 1908-2008

    Treesearch

    Susan D. Olberding; Margaret M. Moore

    2008-01-01

    One hundred years ago, the USFS began its forest research program in a two-room cabin near Flagstaff, Arizona, with one staff person, Gustaf A. Pearson. The site became known as the Fort Valley Experiment Station and was the first in a national network of research sites developed to address uncertainties regarding the rehabilitation and conservation for forest and...

  14. Minimum Input Techniques for Valley Oak Restocking

    Treesearch

    Elizabeth A. Bernhardt; Tedmund J. Swiecki

    1991-01-01

    We set up experiments at four locations in northern California to demonstrate minimum input techniques for restocking valley oak, Quercus lobata. Overall emergence of acorns planted in 1989 ranged from 47 to 61 percent. Use of supplemental irrigation had a significant positive effect on seedling growth at two of three sites. Mulch, of organic...

  15. MX Siting Investigation. Gravity Survey - Southern Snake Valley (Ferguson Desert), Utah.

    DTIC Science & Technology

    1980-03-28

    Topographic Center (DMAHTC), head- quartered in Cheyenne, Wyoming. DMAHTC reduces the data to Simple Bouguer Anomaly (see Section A1.4, Appendix Al.0...Valley, Utah . . . . . ......... . . . . . 3 3 Complete Bouguer Anomaly Contours 4 Interpreted Gravity Profile SE-3,4 5 Interpreted Gravity Profile SE...observations and reduced them to Simple Bouguer Anomalies (SBA) for each station as described in Appendix Al.0. Up to three levels of terrain corrections were

  16. Characterization of the Atmospheric Boundary Layer Over Aburrá Valley Region (Colombia) Using Remote Sensing and Radiosonde Data

    NASA Astrophysics Data System (ADS)

    Herrera, L.; Hoyos Ortiz, C. D.

    2017-12-01

    The spatio-temporal evolution of the Atmospheric Boundary Layer (ABL) in the Aburrá Valley, a narrow highly complex mountainous terrain located in the Colombian Andes, is studied using different datasets including radiosonde and remote sensors from the meteorological network of the Aburrá Valley Early Warning System. Different techniques are developed in order to estimate Mixed Layer Height (MLH) based on variance of the ceilometer backscattering profiles. The Medellín metropolitan area, home of 4.5 million people, is located on the base and the hills of the valley. The generally large aerosol load within the valley from anthropogenic emissions allows the use of ceilometer retrievals of the MLH, especially under stable atmospheric conditions (late at night and early in the morning). Convective atmospheres, however, favor the aerosol dispersion which in turns increases the uncertainty associated with the estimation of the Convective Boundary Layer using ceilometer retrievals. A multi-sensor technique is also developed based on Richardson Number estimations using a Radar Wind Profiler combined with a Microwave Radiometer. Results of this technique seem to be more accurate thorough the diurnal cycle. ABL retrievals are available from October 2014 to April 2017. The diurnal cycle of the ABL exhibits monomodal behavior, highly influenced by the evolution of the potential temperature profile, and the turbulent fluxes near the surface. On the other hand, the backscattering diurnal cycle presents a bimodal structure, showing that the amount of aerosol particles at the lower troposphere is strongly influenced by anthropogenic emissions, dispersion conditioned by topography and by the ABL dynamics, conditioning the available vertical height for the pollutants to interact and disperse. Nevertheless, the amount, distribution or type of atmospheric aerosols does not appear to have a first order influence on the MLH variations or evolution. Results also show that intra

  17. Characterization of the Atmospheric Boundary Layer Over Aburrá Valley Region (Colombia) Using Remote Sensing and Radiosonde Data

    NASA Astrophysics Data System (ADS)

    Harlow, R. C.; Blockley, E. W.; Brooks, I. M.; Essery, R.; Milton, S.; Renfrew, I.; Vosper, S.

    2016-12-01

    The spatio-temporal evolution of the Atmospheric Boundary Layer (ABL) in the Aburrá Valley, a narrow highly complex mountainous terrain located in the Colombian Andes, is studied using different datasets including radiosonde and remote sensors from the meteorological network of the Aburrá Valley Early Warning System. Different techniques are developed in order to estimate Mixed Layer Height (MLH) based on variance of the ceilometer backscattering profiles. The Medellín metropolitan area, home of 4.5 million people, is located on the base and the hills of the valley. The generally large aerosol load within the valley from anthropogenic emissions allows the use of ceilometer retrievals of the MLH, especially under stable atmospheric conditions (late at night and early in the morning). Convective atmospheres, however, favor the aerosol dispersion which in turns increases the uncertainty associated with the estimation of the Convective Boundary Layer using ceilometer retrievals. A multi-sensor technique is also developed based on Richardson Number estimations using a Radar Wind Profiler combined with a Microwave Radiometer. Results of this technique seem to be more accurate thorough the diurnal cycle. ABL retrievals are available from October 2014 to April 2017. The diurnal cycle of the ABL exhibits monomodal behavior, highly influenced by the evolution of the potential temperature profile, and the turbulent fluxes near the surface. On the other hand, the backscattering diurnal cycle presents a bimodal structure, showing that the amount of aerosol particles at the lower troposphere is strongly influenced by anthropogenic emissions, dispersion conditioned by topography and by the ABL dynamics, conditioning the available vertical height for the pollutants to interact and disperse. Nevertheless, the amount, distribution or type of atmospheric aerosols does not appear to have a first order influence on the MLH variations or evolution. Results also show that intra

  18. Understanding Particulate Matter Dynamics in the San Joaquin Valley during DISCOVER-AQ, 2013

    NASA Astrophysics Data System (ADS)

    Prabhakar, G.; Zhang, X.; Kim, H.; Parworth, C.; Pusede, S. E.; Wooldridge, P. J.; Cohen, R. C.; Zhang, Q.; Cappa, C. D.

    2015-12-01

    Air quality in the California San Joaquin Valley (SJV) during winter continues to be the worst in the state, failing EPA's 24-hour standard for particulate matter. Despite our improved understanding of the sources of particulate matter (PM) in the valley, air-quality models are unable to predict PM concentrations accurately. We aim to characterize periods of high particulate matter concentrations in the San Joaquin Valley based on ground and airborne measurements of aerosols and gaseous pollutants, during the DISCOVER-AQ campaign, 2013. A highly instrumented aircraft flew across the SJV making three transects in a repeatable pattern, with vertical spirals over select locations. The aircraft measurements were complemented by ground measurements at these locations, with extensive chemically-speciated measurements at a ground "supersite" at Fresno. Hence, the campaign provided a comprehensive three-dimensional view of the particulate and gaseous pollutants around the valley. The vertical profiles over the different sites indicate significant variability in the concentrations and vertical distribution of PM around the valley, which are most likely driven by differences in the combined effects of emissions, chemistry and boundary layer dynamics at each site. The observations suggest that nighttime PM is dominated by surface emissions of PM from residential fuel combustion, while early morning PM is strongly influenced by mixing of low-level, above-surface, nitrate-rich layers formed from dark chemistry overnight to the surface.

  19. Rock Stripes Pattern in Mars' 'Perseverance Valley'

    NASA Image and Video Library

    2018-02-15

    Textured rows on the ground in this portion of "Perseverance Valley" are under investigation by NASA's Mars Exploration Rover Opportunity, which used its Navigation Camera (Navcam) to take the component images of this downhill-looking scene. The rover took this image on Jan. 4, 2018, during the 4,958th Martian day, or sol, of its work on Mars, looking downhill from a position about one-third of the way down the valley. Perseverance Valley descends the inboard slope of the western rim of Endeavour Crater. A view on the same sol with the rover's front Hazard Avoidance Camera includes ground even closer to the rover at this site. Opportunity was still working close by as it reached the mission's Sol 5,000 (Feb. 16, 2018). In the portion of the valley seen here, soil and gravel have been shaped into a striped pattern in the foreground and partially bury outcrops visible in the midfield. The long dimensions of the stripes are approximately aligned with the downhill direction. The striped pattern resembles a type of feature on Earth (such as on Hawaii's Mauna Kea) that is caused by repeated cycles of freezing and thawing, though other possible origins are also under consideration for the pattern in Perseverance Valley. The view is spans from north on the left to east-southeast on the right. For scale, the foreground rock clump in the lower right is about 11 inches (28 centimeters) in width. https://photojournal.jpl.nasa.gov/catalog/PIA22217

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

    USGS Publications Warehouse

    Marston, Thomas M.

    2017-08-29

    . Groundwater flows from the high-altitude recharge areas downward toward the basin-fill aquifer in Parowan Valley. Almost all groundwater discharge occurs as withdrawals from irrigation wells in the valley with a small amount of discharge from phreatophytic evapotranspiration. Subsurface groundwater discharge to Cedar Valley is likely minimal. Withdrawals from wells during 2013 were about 32,000 acre-ft. The estimated withdrawals from wells from 1994 to 2013 have ranged from 22,000 to 39,000 acre-ft per year. Declining water levels are an indication of the estimated average annual decrease in groundwater storage of 15,000 acre-ft from 1994 to 2013.Groundwater and surface-water samples were collected from 46 sites in Parowan Valley and Cedar Valley near the town of Enoch during June 2013. Groundwater samples from 34 wells were submitted for geochemical analysis. The total dissolved-solids concentration in water from these wells ranged from 142 to 886 milligrams per liter. Results of stable isotope analysis of oxygen and deuterium from groundwater and surface-water samples indicate that most of the groundwater in Parowan Valley and in Cedar Valley near Enoch is similar in isotopic composition to water from mountain streams, which reflects meteoric water recharged in high-altitude areas east of the valley. In addition, results of stable isotope analysis of a subset of samples from wells located near Little Salt Lake may indicate recharge of precipitation that occurred during cooler climatic conditions of the Pleistocene Epoch.

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

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-05

    ... Valley Warm Springs Management Plan/Environmental Impact Statement, Death Valley National Park, Inyo... an Environmental Impact Statement for the Saline Valley Warm Springs Management Plan, Death Valley... analysis process for the Saline Valley Warm Springs Management Plan for Death Valley [[Page 33238...

  2. Hydrogeological Interpretation of Candidate Origin Sites for Martian Meteorite ALH84001

    NASA Technical Reports Server (NTRS)

    Gulick, Virginia C.; McKay, Chris; Cuzzi, Jeffrey N. (Technical Monitor)

    1996-01-01

    Barlow (this meeting) has identified two potential source craters for the martian meteorite ALH84001. The craters are at 11.7 deg S, 243.3 deg W (Mare Tyrrhenum site) and 14.0 deg S, 343.5 deg W (Sinus Sabaeus site). As noted by Barlow, both craters lie in the heavily cratered terrain (HCT) and are adjacent to fluvial valleys, Here I explore the fluvial history of these areas based upon the surrounding valley morphology. The most prominent valley network at the Sabaeus site is Evros Vallis. This wide, flat-floored valley is approximately 600 km long with an average width of 2.5 km and a depth of 220 m. The eroded volume of the entire Evros network is approximately 6 x 10(exp 11) cc. This is typical for networks located in the heavily cratered terrain (e.g. Warrego and Parana Valles). Evros is also an isolated valley system. No similar networks are found in the surrounding terrain. Thus it is unlikely that Evros formed as a result of widespread rainfall. A localized water source, such as discharge of a hydrothermal system or localized melting of snowfall, seems more consistent Previous modeling has demonstrated that only hydrothermal systems associated with high permeability subsurfaces can discharge sufficient water to form a valley network. The bulk of the discharge from such systems is consequently low temperature, slightly heated water Precipitation of calcium carbonate by low temperature fluids is consistent with most interpretations of the geochemistry of ALH84001. Available imagery at the Tyrrhenum site is of lesser quality. While eroded units of the HCT are nearby, there are no comparable well developed valley networks at this site. Erosion is instead manifested predominantly as gullies on slopes. This style of erosion suggests that water was not present at this site for the length of time as at the more integrated Sabaeus site. The superposition of fluidized ejecta blankets suggests however that ground water or ground ice was still present at this locality

  3. Application of airborne remote sensing to the ancient Pompeii site

    NASA Astrophysics Data System (ADS)

    Vitiello, Fausto; Giordano, Antonio; Borfecchia, Flavio; Martini, Sandro; De Cecco, Luigi

    1996-12-01

    The ancient Pompeii site is in the Sarno Valley, an area of about 400 km2 in the South of Italy near Naples, that was utilized by man since old time (thousands of years ago). Actually the valley is under critical environmental conditions because of the relevant industrial development. ENEA is conducting various studies and research in the valley. ENEA is employing historical research, ground campaigns, cartography and up-to-date airborne multispectral remote sensing technologies to make a geographical information system. Airborne remote sensing technologies are very suitable for situations as that of the Sarno Valley. The paper describes the archaeological application of the research in progress as regarding the ancient site of Pompeii and its fluvial port.

  4. 27 CFR 9.57 - Green Valley of Russian River Valley.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Green Valley of Russian River Valley. 9.57 Section 9.57 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.57 Green Valley of Russian River...

  5. 27 CFR 9.57 - Green Valley of Russian River Valley.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Green Valley of Russian River Valley. 9.57 Section 9.57 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.57 Green Valley of Russian River...

  6. 27 CFR 9.57 - Green Valley of Russian River Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Green Valley of Russian River Valley. 9.57 Section 9.57 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.57 Green Valley of Russian River...

  7. 27 CFR 9.57 - Green Valley of Russian River Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Green Valley of Russian River Valley. 9.57 Section 9.57 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.57 Green Valley of Russian River...

  8. 27 CFR 9.57 - Green Valley of Russian River Valley.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Green Valley of Russian River Valley. 9.57 Section 9.57 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.57 Green Valley of Russian River...

  9. Selenium bioaccumulation in fish exposed to coal ash at the Tennessee Valley Authority Kingston spill site.

    PubMed

    Mathews, Teresa J; Fortner, Allison M; Jett, R Trent; Morris, Jesse; Gable, Jennifer; Peterson, Mark J; Carriker, Neil

    2014-10-01

    In December 2008, 4.1 million cubic meters of coal ash were released into the Emory and Clinch Rivers by the Tennessee Valley Authority Kingston Fossil Plant. Coal ash contains several contaminants, including the bioaccumulative metalloid selenium (Se). Because Se is predominantly accumulated in aquatic organisms through dietary rather than aqueous exposure, tissue-based toxicity thresholds for Se are currently being considered. The proposed threshold concentrations range between 4 μg/g and 9 μg/g Se (dry wt.) in whole body fish, with a proposed fillet threshold of 11.8 μg/g. In the present study, the authors examined the spatial and temporal trends in Se bioaccumulation and examined the relationship between the Se content in fillets and in whole bodies of fish collected around the Kingston spill site to determine whether Se bioaccumulation was a significant concern at the ash spill site. Whereas Se concentrations in fish (whole bodies and fillets) were elevated at sampling locations affected by the Kingston ash spill relative to reference locations, concentrations do not appear to be above risk thresholds and have not been increasing over the 5-yr period since the spill. These findings are not only relevant to guiding the human health and ecological risk assessments at the Kingston ash spill site, but because of current national discussions on appropriate guidelines for Se in fish as well for the disposal of coal combustion wastes, the results are also relevant to the general understanding of Se bioaccumulation in contaminated water bodies. © 2014 SETAC.

  10. A Summary interpretation of geologic, hydrologic, and geophysical data for Yucca Valley, Nevada test site, Nye County, Nevada

    USGS Publications Warehouse

    Wilmarth, Verl Richard; Healey, D.L.; Clebsch, Alfred; Winograd, I.J.; Zietz, Isadore; Oliver, H.W.

    1959-01-01

    This report summarizes an interpretation of the geology of Yucca Valley to depths of about 2,300 feet below the surface, the characteristics features of ground water in Yucca and Frenchman Valleys, and the seismic, gravity, and magnetic data for these valleys. Compilation of data, preparation of illustrations, and writing of the report were completed during the period December 26, 1958 to January 10, 1959. Some of the general conclusions must be considered as tentative until more data are available. This work was done by the U.S. Geological Survey on behalf of Albuquerque Operations Office, U.S. Atomic Energy Commission.

  11. Geohydrology of the Unconsolidated Valley-Fill Aquifer in the Meads Creek Valley, Schuyler and Steuben Counties, New York

    USGS Publications Warehouse

    Miller, Todd S.; Bugliosi, Edward F.; Reddy, James E.

    2008-01-01

    The Meads Creek valley encompasses 70 square miles of predominantly forested uplands in the upper Susquehanna River drainage basin. The valley, which was listed as a Priority Waterbody by the New York State Department of Environmental Conservation in 2004, is prone to periodic flooding, mostly in its downstream end, where development is occurring most rapidly. Hydraulic characteristics of the unconsolidated valley-fill aquifer were evaluated, and seepage rates in losing and gaining tributaries were calculated or estimated, in an effort to delineate the aquifer geometry and identify the factors that contribute to flooding. Results indicated that (1) Meads Creek gained about 61 cubic feet of flow per second (about 6.0 cubic feet per second per mile of stream channel) from ground-water discharge and inflow from tributaries in its 10.2-mile reach between the northernmost and southernmost measurement sites; (2) major tributaries in the northern part of the valley are not significant sources of recharge to the aquifer; and (3) major tributaries in the central and southern part of the valley provide recharge to the aquifer. The ground-water portion of streamflow in Meads Creek (excluding tributary inflow) was 11.3 cubic feet per second (ft3/s) in the central part of the valley and 17.2 ft3/s in the southern part - a total of 28.5 ft3/s. Ground-water levels were measured in 29 wells finished in unconfined deposits for construction of a potentiometric-surface map to depict directions of ground-water flow within the valley. In general, ground water flows from the edges of the valley toward Meads Creek and ultimately discharges to it. The horizontal hydraulic gradient for the entire 12-mile-long aquifer averages about 30 feet per mile, whereas the gradient in the southern fourth of the valley averages about half that - about 17 feet per mile. A water budget for the aquifer indicated that 28 percent of recharge was derived from precipitation that falls on the aquifer, 32

  12. Sex-biased dispersal of young Western Screech-owls (Otus kennicottii) in southwestern Idaho

    Treesearch

    Ethan Ellsworth; James R. Belthoff

    1997-01-01

    We examined dispersal distance of young Western Screech-owls (Otus kennicottii) from nest sites to overwintering sites in relation to two hypotheses for sex-biased dispersal. Overall, young Screech-owls (N = 31) dispersed an average of 10.6 ± 1.8 km to overwintering sites, and females (14.7 ± 2.5 km; N = 13) dispersed farther than...

  13. Great Valley Riparian Habitats and the National Registry of Natural Landmarks

    Treesearch

    Robert F. Holland; Cynthia L. Roye

    1989-01-01

    The National Registry of Natural Landmarks is a program established by the National Park Service that seeks to recognize nationally significant examples of the Nation's natural history. Nearly 100 Great Valley riparian sites were evaluated using Park Service criteria. Three sites illustrative of the range of this biotic theme were recommended to the National Park...

  14. Viking landing sites

    NASA Technical Reports Server (NTRS)

    Panagakos, N.

    1973-01-01

    A valley near the mouth of the 20,000-foot-deep Martian Grand Canyon has been chosen by NASA as the site of its first automated landing on the planet Mars. The landing site for the second mission of the 1975-76 Viking spacecraft will probably be an area about 1,000 miles northeast of the first site, where the likelihood of water increases the chances of finding evidence of life.

  15. Three-dimensional geological modelling of anthropogenic deposits at small urban sites: a case study from Sheepcote Valley, Brighton, UK.

    PubMed

    Tame, C; Cundy, A B; Royse, K R; Smith, M; Moles, N R

    2013-11-15

    Improvements in computing speed and capacity and the increasing collection and digitisation of geological data now allow geoscientists to produce meaningful 3D spatial models of the shallow subsurface in many large urban areas, to predict ground conditions and reduce risk and uncertainty in urban planning. It is not yet clear how useful this 3D modelling approach is at smaller urban scales, where poorly characterised anthropogenic deposits (artificial/made ground and fill) form the dominant subsurface material and where the availability of borehole and other geological data is less comprehensive. This is important as it is these smaller urban sites, with complex site history, which frequently form the focus of urban regeneration and redevelopment schemes. This paper examines the extent to which the 3D modelling approach previously utilised at large urban scales can be extended to smaller less well-characterised urban sites, using a historic landfill site in Sheepcote Valley, Brighton, UK as a case study. Two 3D models were generated and compared using GSI3D™ software, one using borehole data only, one combining borehole data with local geological maps and results from a desk study (involving collation of available site data, including ground contour plans). These models clearly delimit the overall subsurface geology at the site, and allow visualisation and modelling of the anthropogenic deposits present. Shallow geophysical data collected from the site partially validate the 3D modelled data, and can improve GSI3D™ outputs where boundaries of anthropogenic deposits may not be clearly defined by surface, contour or borehole data. Attribution of geotechnical and geochemical properties to the 3D model is problematic without intrusive investigations and sampling. However, combining available borehole data, shallow geophysical methods and site histories may allow attribution of generic fill properties, and consequent reduction of urban development risk and

  16. A Hierarchical Network Approach for Modeling Rift Valley Fever Epidemics with Applications in North America

    PubMed Central

    Xue, Ling; Cohnstaedt, Lee W.; Scott, H. Morgan; Scoglio, Caterina

    2013-01-01

    Rift Valley fever is a vector-borne zoonotic disease which causes high morbidity and mortality in livestock. In the event Rift Valley fever virus is introduced to the United States or other non-endemic areas, understanding the potential patterns of spread and the areas at risk based on disease vectors and hosts will be vital for developing mitigation strategies. Presented here is a general network-based mathematical model of Rift Valley fever. Given a lack of empirical data on disease vector species and their vector competence, this discrete time epidemic model uses stochastic parameters following several PERT distributions to model the dynamic interactions between hosts and likely North American mosquito vectors in dispersed geographic areas. Spatial effects and climate factors are also addressed in the model. The model is applied to a large directed asymmetric network of 3,621 nodes based on actual farms to examine a hypothetical introduction to some counties of Texas, an important ranching area in the United States of America. The nodes of the networks represent livestock farms, livestock markets, and feedlots, and the links represent cattle movements and mosquito diffusion between different nodes. Cattle and mosquito (Aedes and Culex) populations are treated with different contact networks to assess virus propagation. Rift Valley fever virus spread is assessed under various initial infection conditions (infected mosquito eggs, adults or cattle). A surprising trend is fewer initial infectious organisms result in a longer delay before a larger and more prolonged outbreak. The delay is likely caused by a lack of herd immunity while the infection expands geographically before becoming an epidemic involving many dispersed farms and animals almost simultaneously. Cattle movement between farms is a large driver of virus expansion, thus quarantines can be efficient mitigation strategy to prevent further geographic spread. PMID:23667453

  17. A hierarchical network approach for modeling Rift Valley fever epidemics with applications in North America.

    PubMed

    Xue, Ling; Cohnstaedt, Lee W; Scott, H Morgan; Scoglio, Caterina

    2013-01-01

    Rift Valley fever is a vector-borne zoonotic disease which causes high morbidity and mortality in livestock. In the event Rift Valley fever virus is introduced to the United States or other non-endemic areas, understanding the potential patterns of spread and the areas at risk based on disease vectors and hosts will be vital for developing mitigation strategies. Presented here is a general network-based mathematical model of Rift Valley fever. Given a lack of empirical data on disease vector species and their vector competence, this discrete time epidemic model uses stochastic parameters following several PERT distributions to model the dynamic interactions between hosts and likely North American mosquito vectors in dispersed geographic areas. Spatial effects and climate factors are also addressed in the model. The model is applied to a large directed asymmetric network of 3,621 nodes based on actual farms to examine a hypothetical introduction to some counties of Texas, an important ranching area in the United States of America. The nodes of the networks represent livestock farms, livestock markets, and feedlots, and the links represent cattle movements and mosquito diffusion between different nodes. Cattle and mosquito (Aedes and Culex) populations are treated with different contact networks to assess virus propagation. Rift Valley fever virus spread is assessed under various initial infection conditions (infected mosquito eggs, adults or cattle). A surprising trend is fewer initial infectious organisms result in a longer delay before a larger and more prolonged outbreak. The delay is likely caused by a lack of herd immunity while the infection expands geographically before becoming an epidemic involving many dispersed farms and animals almost simultaneously. Cattle movement between farms is a large driver of virus expansion, thus quarantines can be efficient mitigation strategy to prevent further geographic spread.

  18. Field studies of transport and dispersion of atmospheric tracers in nocturnal drainage flows

    Treesearch

    Paul H. Gudiksen; Gilbert J. Ferber; Malcolm M. Fowler; Wynn L. Eberhard; Michael A. Fosberg; William R. Knuth

    1984-01-01

    A series of tracer experiments were carried out as part of the Atmospheric Studies in Complex Terrain (ASCOT) program to evaluate pollutant transport and dispersion characteristics of nocturnal drainage flows within a valley in northern California. The results indicate that the degree of interaction of the drainage flows with the larger scale regional flows are...

  19. Morphology of large valleys on Hawaii - Evidence for groundwater sapping and comparisons with Martian valleys

    NASA Technical Reports Server (NTRS)

    Kochel, R. Craig; Piper, Jonathan F.

    1986-01-01

    Morphometric data on the runoff and sapping valleys on the slopes of Hawaii and Molokai in Hawaii are analyzed. The analysis reveals a clear distinction between the runoff valleys and sapping valleys. The Hawaiian sapping valleys are characterized by: (1) steep valley walls and flat floors, (2) amphitheater heads, (3) low drainage density, (4) paucity of downstream tributaries, (5) low frequency of up-dip tributaries, and (6) structural and stratigraphic control on valley patterns. The characteristics of the Hawaiian sapping valleys are compared to Martian valleys and experimental systems, and good correlation between the data is detected. Flume experiments were also conducted to study the evolution of sapping valleys in response to variable structure and stratigraphy.

  20. Atomically dispersed metal sites in MOF-based materials for electrocatalytic and photocatalytic energy conversion.

    PubMed

    Liang, Zibin; Qu, Chong; Xia, Dingguo; Zou, Ruqiang; Xu, Qiang

    2018-02-19

    Metal sites play an essential role for both electrocatalytic and photocatalytic energy conversion applications. The highly ordered arrangements of the organic linkers and metal nodes and the well-defined pore structures of metal-organic frameworks (MOFs) make them ideal substrates to support atomically dispersed metal sites (ADMSs) located in their metal nodes, linkers, and pores. Besides, porous carbon materials doped with ADMSs can be derived from these ADMS-incorporated MOF precursors through controlled treatments. These ADMSs incorporated in pristine MOFs and MOF-derived carbon materials possess unique merits over the molecular or the bulk metal-based catalysts, bridging the gap between homogeneous and heterogeneous catalysts for energy conversion applications. In this review, recent progress and perspective of design and incorporation of ADMSs in pristine MOFs and MOF-derived materials for energy conversion applications are highlighted, which will hopefully promote further developments of advanced MOF-based catalysts in foreseeable future. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Beaver assisted river valley formation

    USGS Publications Warehouse

    Westbrook, Cherie 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.

  2. Report on the Threatened Valley Elderberry Longhorn Beetle and its Elderberry Food Plant at the Lawrence Livermore National Laboratory--Site 300

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Arnold, Ph.D., R A; Woollett, J

    2004-11-16

    This report describes the results of an entomological survey in 2002 to determine the presence of the federally-listed, threatened Valley Elderberry Longhorn Beetle or ''VELB'' (Desmocerus culifornicus dimorphus: Coleoptera, Cerambycidae) and its elderberry food plant (Sumbucus mexicana: Caprifoliaceae) on the Lawrence Livermore National Laboratory's (LLNL) Experimental Test Site, known as Site 300. In addition, an area located immediately southeast of Site 300, which is owned and managed by the California Department of Fish and Game (CDFG), but secured by LLNL, was also included in this survey. This report will refer to the survey areas as the LLNL-Site 300 and themore » CDFG site. The 2002 survey included mapping the locations of elderberry plants that were observed using a global positioning system (GPS) to obtain positional coordinates for every elderberry plant at Site 300. In addition, observations of VELB adults and signs of their infestation on elderberry plants were also mapped using GPS technology. LLNL requested information on the VELB and its elderberry food plants to update earlier information that had been collected in 1991 (Arnold 1991) as part of the 1992 EIS/EIR for continued operation of LLNL. No VELB adults were observed as part of this prior survey. The findings of the 2002 survey reported herein will be used by LLNL as it updates the expected 2004 Environmental Impact Statement for ongoing operations at LLNL, including Site 300.« less

  3. Central Avra Valley Storage and Recovery Project (CAVSARP) Site, Tucson, Arizona: Floodwater and Soil Moisture Investigations with Extraterrestrial Applications

    NASA Technical Reports Server (NTRS)

    Rucker, D. F.; Dohm, J. M.; Ferre, T. P. A.; Ip, Felipe; Baker, V. R.; Davies, A. G.; Castano, R.; Chien, S.; Doggett, T. C.

    2004-01-01

    Planetary geologists, geomorphologists, and hydrologists have hypothesized that Mars is a dynamic, water-enriched planet since the Mariner and Viking missions based on geologic, geomorphic, and topographic information. Recent acquisition of Gamma Ray and Neutron Spectrometer information has added further credence to this hypothesis. A unique investigation is underway to work towards being able to successfully map the extent and depth of water on Mars. Researchers from the University of Arizona and members of the Autonomous Sciencecraft Experiment (ASE) have been compiling multiple layers of information in time and space at the Central Avra Valley Storage and Recovery Project (CAVSARP) site, Tucson, Arizona, for eventual comparative analysis. This information has been acquired from a variety of observational/scientific platforms in controlled conditions. CAVSARP facility:

  4. Three years of hillslope sediment yields following the Valley Complex fires, western Montana

    Treesearch

    Peter R. Robichaud; Joseph W. Wagenbrenner; Robert E. Brown; Kevin M. Spigel

    2009-01-01

    The 2000 Bitterroot Valley wildfires provided an opportunity to measure post-fire effects and recovery rates. We established 24 small (0.01 ha [0.02 acre]) plots in four high-severity burn sites. We measured sediment yields at each site with silt fences. We also measured rainfall characteristics, soil water repellency, vegetative cover, and other site characteristics....

  5. ASSESSING TRANSBOUNDARY INFLUENCES IN THE LOWER RIO GRANDE VALLEY

    EPA Science Inventory

    The Lower Rio Grande Valley Transboundary Air Pollution Project (TAPP) was a U.S.-Mexico Border XXI Program project to assess transboundary air pollution in and near Brownsville, Texas. The study used a three-site air monitoring network very close to the border to capture the d...

  6. The dark side of the tradition: the polluting effect of Epiphany folk fires in the eastern Po Valley (Italy).

    PubMed

    Masiol, Mauro; Formenton, Gianni; Giraldo, Giorgia; Pasqualetto, Alberto; Tieppo, Paulo; Pavoni, Bruno

    2014-03-01

    In the Veneto Region (Po Valley, Northeastern Italy) on the eve of Epiphany, an important religious celebration, during the night between January 5th and 6th thousands of folk fires traditionally burn wooden material. The object of this study is to characterize the 2013 episode, by monitoring the effects on the air quality in the region's lowlands. The daily concentrations of PM2.5 and PM10 exceeded 250 and 300 μg m(-3), respectively and the PM10 hourly values were above 600 μg m(-3) in many sites. The levels of total carbon, major inorganic ions, polycyclic aromatic hydrocarbons and biomass burning tracers (levoglucosan and K(+)) were measured in 84 samples of PM10 and 38 of PM2.5 collected at 32 sites between January 4th and 7th. Total carbon ranged from 11 μg m(-3) before the pollution episode to 131 μg m(-3) a day afterwards, K(+) from 0.6 to 5.1μg m(-3), benzo(a)pyrene from 2 to 23 ng m(-3), and levoglucosan from 0.5 to 8.3 μg m(-3). The dispersion of the particulate matter was traced by analyzing the levels of PM10 and PM2.5 in 133 and 51 sites, respectively, in the Veneto and neighboring regions. In addition to biomass burning the formation of secondary inorganic aerosol was revealed to be a key factor on a multivariate statistical data processing. By providing direct information on the effects of an intense and widespread biomass burning episode in the Po Valley, this study also enables some general considerations on biomass burning practices. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Diversity of micro-fungi in an Antarctic dry valley

    NASA Technical Reports Server (NTRS)

    Baublis, J. A.; Wharton, R. A. Jr; Volz, P. A.; Wharton RA, J. r. (Principal Investigator)

    1991-01-01

    The fungal microflora of a dry valley in Southern Victoria Land near McMurdo Sound, Antarctica, was investigated. Samples were collected from introduced objects such as a mummified penguin and spent chewing tobacco in addition to the sparse soil found in rock fissures, isolated moss colonies, shoreline deposit materials, CaCO3 precipitates, and microbial mat debris obtained from the frozen surface of the lake in the basin of Taylor Valley. Using conventional media and techniques, all collection sites yielded populations of yeasts and filamentous fungi. Water samples and live microbial mats from beneath the lake ice yielded species of fungi along with an abundance of bacteria.

  8. M’zab Valley, Algeria

    NASA Image and Video Library

    2017-12-08

    NASA image acquired Feb. 9, 2011 Less than 5 percent of Algeria’s land surface is suitable for growing crops, and most precipitation falls on the Atlas Mountains along the coast. Inland, dust-laden winds blow over rocky plains and sand seas. However, in north central Algeria—off the tip of Grand Erg Occidental and about 450 kilometers (280 miles) south of Algiers—lies a serpentine stretch of vegetation. It is the M’zab Valley, filled with palm groves and dotted with centuries-old settlements. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA’s Terra satellite captured this image of M’zab Valley on February 9, 2011. ASTER combines infrared, red, and green wavelengths of light. Bare rock ranges in color from beige to peach. Buildings and paved surfaces appear gray. Vegetation is red, and brighter shades of red indicate more robust vegetation. This oasis results from water that is otherwise in short supply in the Sahara Desert, thanks to the valley’s approximately 3,000 wells. Chemical analysis of Algerian aquifers, as well studies of topography in Algeria and Tunisia, suggest this region experienced a cooler climate in the late Pleistocene, and potentially heavy monsoon rains earlier in the Holocene. The M’zab region shows evidence of meandering rivers and pinnate drainage patterns. The vegetation lining M’zab Valley highlights this old river valley’s contours. Cool summer temperatures and monsoon rains had long since retreated from the region by eleventh century, but this valley nevertheless supported the establishment of multiple fortified settlements, or ksours. Between 1012 A.D. and 1350 A.D., locals established the ksours of El-Atteuf, Bounoura, Melika, Ghardaïa, and Beni-Isguen. Collectively these cities are now a United Nations Educational, Scientific, and Cultural Organization (UNESCO) World Heritage site. NASA Earth Observatory image by Robert Simmon and Jesse Allen, using data from the GSFC

  9. Dispersal Timing: Emigration of Insects Living in Patchy Environments.

    PubMed

    Lakovic, Milica; Poethke, Hans-Joachim; Hovestadt, Thomas

    2015-01-01

    Dispersal is a life-history trait affecting dynamics and persistence of populations; it evolves under various known selective pressures. Theoretical studies on dispersal typically assume 'natal dispersal', where individuals emigrate right after birth. But emigration may also occur during a later moment within a reproductive season ('breeding dispersal'). For example, some female butterflies first deposit eggs in their natal patch before migrating to other site(s) to continue egg-laying there. How breeding compared to natal dispersal influences the evolution of dispersal has not been explored. To close this gap we used an individual-based simulation approach to analyze (i) the evolution of timing of breeding dispersal in annual organisms, (ii) its influence on dispersal (compared to natal dispersal). Furthermore, we tested (iii) its performance in direct evolutionary contest with individuals following a natal dispersal strategy. Our results show that evolution should typically result in lower dispersal under breeding dispersal, especially when costs of dispersal are low and population size is small. By distributing offspring evenly across two patches, breeding dispersal allows reducing direct sibling competition in the next generation whereas natal dispersal can only reduce trans-generational kin competition by producing highly dispersive offspring in each generation. The added benefit of breeding dispersal is most prominent in patches with small population sizes. Finally, the evolutionary contests show that a breeding dispersal strategy would universally out-compete natal dispersal.

  10. Properties of Noise Cross Correlation Functions Obtained from a Distributed Acoustic Sensing (DAS) Array at Garner Valley, California

    NASA Astrophysics Data System (ADS)

    Zeng, X.; Lancelle, C.; Thurber, C. H.; Fratta, D.; Wang, H. F.; Chalari, A.; Clarke, A.

    2015-12-01

    The field test of Distributed Acoustic Sensing (DAS) conducted at Garner Valley, California on September 11-12, 2013 provided a continuous overnight record of ambient noise. The DAS array recorded ground motions every one meter of optical cable that was arranged approximately in the shape of a rectangle with dimensions of 160 m by 80 m. The long dimension of the array was adjacent to a state highway. Three hours of record were used to compute noise cross-correlation functions (NCFs) in one-minute windows. The trace from each sensor channel was pre-processed by downsampling to 200 Hz, followed by normalization in the time-domain and bandpass filtering between 2 and 20 Hz (Bensen et al., 2007). The one-minute NCFs were then stacked using the time-frequency domain phase-weighted stacking method (Schimmel & Gallart, 2007). The NCFs between channels were asymmetrical reflecting the direction of traffic noise. The group velocities were found using the frequency-time analysis method. The energy was concentrated between 5 and 15 Hz, which falls into the typical traffic noise frequency band. The resulting velocities were between 100 and 300 m/s for frequencies between 10 and 20 Hz, which are in the same range as described in the results for surface-wave dispersion obtained using an active source for the same site (Lancelle et al., 2015). The group velocity starts to decrease for frequencies greater than ~10 Hz, which was expected on the basis of a previous shear-wave velocity model (Steidl et al., 1996). Then, the phase velocity was calculated using the multichannel analysis of surface wave technique (MASW - Park et al., 1999) with 114 NCFs spaced one meter apart. The resulting dispersion curve between 5 and 15 Hz gave phase velocities that ranged from approximately 170 m/s at 15 Hz to 250 m/s at 5 Hz. These results are consistent with other results of active-source DAS and seismometer records obtained at the Garner Valley site (e.g., Stokoe et al. 2004). This analysis is

  11. Valley Fever (Coccidioidomycosis) Statistics

    MedlinePlus

    ... Valley fever may be under-recognized. 2 , 3 Public health surveillance for Valley fever Valley fever is reportable ... MMWR) . Check with your local, state, or territorial public health department for more information about disease reporting requirements ...

  12. Conserving archaeological sites as biological and historical resources in the Gulf of Mexico: the effects of crude oil and dispersant on the biodiversity and corrosion potential of shipwreck bacterial biofilms

    NASA Astrophysics Data System (ADS)

    Salerno, J. L.; Little, B.; Lee, J.; Ray, R.; Hamdan, L. J.

    2016-02-01

    There are more than 2,000 documented shipwrecks in the Gulf of Mexico. Historic shipwrecks are invaluable cultural resources, but also serve as artificial reefs, enhancing biodiversity in the deep sea. Oil and gas-related activities have the potential to impact shipwreck sites. An estimated 30% of the oil from the Deepwater Horizon spill was deposited in the deep-sea, in areas that contain shipwrecks. We conducted field and laboratory experiments to determine if crude oil, dispersed oil, and/or dispersant affect the community composition, metabolic function, and/or corrosion potential of microorganisms inhabiting shipwrecks. Platforms containing carbon steel coupons (CSC) (n = 34 per platform) were placed at impacted and non-impacted shipwrecks or into four experimental microcosm tanks. After a 2-week acclimation period, tanks were treated with crude oil and/or dispersant or received no treatment. CSC and seawater (SW) samples for bacterial genetic analysis were collected bi-weekly (at 16 wks for field samples). Proteobacteria dominated field and lab CSC bacterial communities (77-97% of sequences). Field CSC bacterial communities differed at each wreck site (P = 0.001), with oil-impacted sites differing from control sites. Lab CSC bacterial communities differed between all treatment groups (P = 0.005) and changed over the course of the experiment (P = 0.001). CSC bacterial species richness, diversity, and dominance increased with time across all treatments indicating the recruitment and establishment of microbial biofilms on CSCs. SW bacterial communities differed between treatment groups (P = 0.001), with the dispersant treatment being most dissimilar from all other treatments (P < 0.01), and changed over time (P = 0.001). Oil- and oil/dispersant-treated CSCs exhibited higher corrosion compared to dispersant and control treatments. These findings indicate that exposure to oil and/or dispersant may alter bacterial community composition and corrosion potential.

  13. Understanding the behavior of carbon dioxide and surface energy fluxes in semiarid Salt Lake Valley, Utah, USA

    NASA Astrophysics Data System (ADS)

    Ramamurthy, Prathap

    This dissertation reports the findings from the Salt Lake Valley flux study. The Salt Lake Valley flux study was designed to improve our understanding of the complex land-atmosphere interactions in urban areas. The flux study used the eddy covariance technique to quantify carbon dioxide and surface energy budget in the semiarid Salt Lake Valley. Apart from quantifying fluxes, the study has also added new insight into the nature of turbulent scalar transport in urban areas and has addressed some of the complications in using Eddy Covariance technique in urban areas. As part of this experiment, eddy fluxes of CO2 and surface energy fluxes were measured at two sites, with distinct urban landforms; One site was located in a suburban neighborhood with substantial vegetative cover, prototypical of many residential neighborhoods in the valley. The other CO2 site was in a preurban surrounding that resembled the Salt Lake Valley before it was urbanized. The two sites were intentionally chosen to illustrate the impact of urbanization on CO 2 and surface energy flux cycles. Results indicate that the suburban site acted as a sink of CO2 during the midday period due to photosynthesis and acted as a source of CO2 during the evening and nighttime periods. The vegetative cover around the suburban site also had a significant impact on the surface energy fluxes. Contribution from latent heat flux was substantially high at the suburban site during the summer months compared to sensible heat. The turbulence investigation found that the general behavior of turbulence was very much influenced by local factors and the statistics did not always obey Monin-Obukhov Similarity parameters. This investigation also found that the scalar (co)spectra observed at the suburban site were characterized by multiple peaks and were different compared to (co)spectra reported over forest and crop canopies. The study also observed multiscale CO2 transport at the suburban site during the convective period

  14. Fort Valley Experimental Forest-A Century of Research 1908-2008 (P-53)

    Treesearch

    Susan D. Olberding; Margaret M. Moore

    2008-01-01

    One hundred years ago, the USFS began its forest research program in a two-room cabin near Flagstaff, Arizona, with one staff person, Gustaf A. Pearson. The site became known as the Fort Valley Experiment Station and was the first in a national network of research sites developed to address uncertainties regarding the rehabilitation and conservation for forest and...

  15. Desert Test Site Uniformity Analysis

    NASA Technical Reports Server (NTRS)

    Kerola, Dana X.; Bruegge, Carol J.

    2009-01-01

    Desert test sites such as Railroad Valley (RRV) Nevada, Egypt-1, and Libya-4 are commonly targeted to assess the on-orbit radiometric performance of sensors. Railroad Valley is used for vicarious calibration experiments, where a field-team makes ground measurements to produce accurate estimates of top-of-atmosphere (TOA) radiances. The Sahara desert test sites are not instrumented, but provide a stable target that can be used for sensor cross-comparisons, or for stability monitoring of a single sensor. These sites are of interest to NASA's Atmospheric Carbon Observation from Space (ACOS) and JAXA's Greenhouse Gas Observation SATellite (GOSAT) programs. This study assesses the utility of these three test sites to the ACOS and GOSAT calibration teams. To simulate errors in sensor-measured radiance with pointing errors, simulated data have been created using MODIS Aqua data. MODIS data are further utilized to validate the campaign data acquired from June 22 through July 5, 2009. The first GOSAT vicarious calibration experiment was conducted during this timeframe.

  16. Water-quality data from ground- and surface-water sites near concentrated animal feeding operations (CAFOs) and non-CAFOs in the Shenandoah Valley and eastern shore of Virginia, January-February, 2004

    USGS Publications Warehouse

    Rice, Karen C.; Monti, Michele M.; Ettinger, Matthew R.

    2005-01-01

    Concentrated animal feeding operations (CAFOs) result from the consolidation of small farms with animals into larger operations, leading to a higher density of animals per unit of land on CAFOs than on small farms. The density of animals and subsequent concentration of animal wastes potentially can cause contamination of nearby ground and surface waters. This report summarizes water-quality data collected from agricultural sites in the Shenandoah Valley and Eastern Shore of Virginia. Five sites, three non-CAFO and two dairy-operation CAFO sites, were sampled in the Shenandoah Valley. Four sites, one non-CAFO and three poultry-operation CAFO sites were sampled on the Eastern Shore. All samples were collected during January and February 2004. Water samples were analyzed for the following parameters and constituents: temperature, specific conductance, pH, and dissolved oxygen; concentrations of the indicator organisms Escherichia coli (E. coli) and enterococci; bacterial isolates of E. coli, enterococci, Salmonella spp., and Campylobacter spp.; sensitivity to antibiotics of E. coli, enterococci, and Salmonella spp.; arsenic, cadmium, chromium3+, copper, nickel, and mercury; hardness, biological oxygen demand, nitrate, nitrite, ammonia, ortho-phosphate, total Kjeldahl nitrogen, chemical oxygen demand, total organic carbon, and dissolved organic carbon; and 45 dissolved organic compounds, which included a suite of antibiotic compounds.Data are presented in tables 5-21 and results of analyses of replicate samples are presented in tables 22-28. A summary of the data in tables 5-8 and 18-21 is included in the report.

  17. Klein tunneling and electron optics in Dirac-Weyl fermion systems with tilted energy dispersion

    NASA Astrophysics Data System (ADS)

    Nguyen, V. Hung; Charlier, J.-C.

    2018-06-01

    The transport properties of relativisticlike fermions have been extensively studied in solid-state systems with isotropic energy dispersions. Recently, several two-dimensional and three-dimensional Dirac-Weyl (DW) materials exhibiting tilted energy dispersions around their DW cones have been explored. Here, we demonstrate that such a tilt character could induce drastically different transport phenomena, compared to the isotropic-dispersion cases. Indeed, the Klein tunneling of DW fermions of opposite chiralities is predicted to appear along two separated oblique directions. In addition, valley filtering and beam splitting effects are easily tailored by dopant engineering techniques whereas the refraction of electron waves at a (p -n )-doped interface is dramatically modified by the tilt, thus paving the way for emerging applications in electron optics and valleytronics.

  18. Feds deed Ward Valley site

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    NONE

    1995-06-12

    This article is a review of the efforts to site a low-level waste repository in California. To resolve a long-running dispute, the US Government has agreed to deed to the state 1000 acres of land in the Mohave Desert. It was noted that environmentalists are unhappy with this action, and it was also noted by the prime contractor (US Ecology) that the facility can be finished six to nine months after the legal challenges are finished.

  19. Study on evaluation methods for Rayleigh wave dispersion characteristic

    USGS Publications Warehouse

    Shi, L.; Tao, X.; Kayen, R.; Shi, H.; Yan, S.

    2005-01-01

    The evaluation of Rayleigh wave dispersion characteristic is the key step for detecting S-wave velocity structure. By comparing the dispersion curves directly with the spectra analysis of surface waves (SASW) method, rather than comparing the S-wave velocity structure, the validity and precision of microtremor-array method (MAM) can be evaluated more objectively. The results from the China - US joint surface wave investigation in 26 sites in Tangshan, China, show that the MAM has the same precision with SASW method in 83% of the 26 sites. The MAM is valid for Rayleigh wave dispersion characteristic testing and has great application potentiality for site S-wave velocity structure detection.

  20. Long-term trend and variability of atmospheric PM10 concentration in the Po Valley

    NASA Astrophysics Data System (ADS)

    Bigi, A.; Ghermandi, G.

    2014-05-01

    The limits to atmospheric pollutant concentration set by the European Commission provide a challenging target for the municipalities in the Po Valley, because of the characteristic climatic conditions and high population density of this region. In order to assess climatology and trends in the concentration of atmospheric particles in the Po Valley, a data set of PM10 data from 41 sites across the Po Valley have been analysed, including both traffic and background sites (either urban, suburban or rural). Of these 41 sites, 18 with 10 yr or longer record have been analysed for long-term trend in deseasonalized monthly means, in annual quantiles and in monthly frequency distribution. A widespread significant decreasing trend has been observed at most sites, up to a few percent per year, by a generalized least squares and Theil-Sen method. All 41 sites have been tested for significant weekly periodicity by Kruskal-Wallis test for mean anomalies and by Wilcoxon test for weekend effect magnitude. A significant weekly periodicity has been observed for most PM10 series, particularly in summer and ascribed mainly to anthropic particulate emissions. A cluster analysis has been applied in order to highlight stations sharing similar pollution conditions over the reference period. Five clusters have been found, two encompassing the metropolitan areas of Turin and Milan and their respective nearby sites and the other three clusters gathering northeast, northwest and central Po Valley sites respectively. Finally, the observed trends in atmospheric PM10 have been compared to trends in provincial emissions of particulates and PM precursors, and analysed along with data on vehicular fleet age, composition and fuel sales. A significant basin-wide drop in emissions occurred for gaseous pollutants, contrarily to emissions of PM10 and PM2.5, whose drop was low and restricted to a few provinces. It is not clear whether the decrease for only gaseous emissions is sufficient to explain the

  1. Delineation of the Pahute Mesa–Oasis Valley groundwater basin, Nevada

    USGS Publications Warehouse

    Fenelon, Joseph M.; Halford, Keith J.; Moreo, Michael T.

    2016-01-22

    This report delineates the Pahute Mesa–Oasis Valley (PMOV) groundwater basin, where recharge occurs, moves downgradient, and discharges to Oasis Valley, Nevada. About 5,900 acre-feet of water discharges annually from Oasis Valley, an area of springs and seeps near the town of Beatty in southern Nevada. Radionuclides in groundwater beneath Pahute Mesa, an area of historical underground nuclear testing at the Nevada National Security Site, are believed to be migrating toward Oasis Valley. Delineating the boundary of the PMOV groundwater basin is necessary to adequately assess the potential for transport of radionuclides from Pahute Mesa to Oasis Valley.The PMOV contributing area is defined based on regional water-level contours, geologic controls, and knowledge of adjacent flow systems. The viability of this area as the contributing area to Oasis Valley and the absence of significant interbasin flow between the PMOV groundwater basin and adjacent basins are shown regionally and locally. Regional constraints on the location of the contributing area boundary and on the absence of interbasin groundwater flow are shown by balancing groundwater discharges in the PMOV groundwater basin and adjacent basins against available water from precipitation. Internal consistency for the delineated contributing area is shown by matching measured water levels, groundwater discharges, and transmissivities with simulated results from a single-layer, steady-state, groundwater-flow model. An alternative basin boundary extending farther north than the final boundary was rejected based on a poor chloride mass balance and a large imbalance in the northern area between preferred and simulated recharge.

  2. Estimation of salt loads for the Dolores River in the Paradox Valley, Colorado, 1980–2015

    USGS Publications Warehouse

    Mast, M. Alisa

    2017-07-13

    Regression models that relate total dissolved solids (TDS) concentrations to specific conductance were used to estimate salt loads for two sites on the Dolores River in the Paradox Valley in western Colorado. The salt-load estimates will be used by the Bureau of Reclamation to evaluate salt loading to the river coming from the Paradox Valley and the effect of the Paradox Valley Unit (PVU), a project designed to reduce the salinity of the Colorado River. A second-order polynomial provided the best fit of the discrete data for both sites on the river. The largest bias occurred in samples with elevated sulfate concentrations (greater than 500 milligrams per liter), which were associated with short-duration runoff events in late summer and fall. Comparison of regression models from a period of time before operation began at the PVU and three periods after operation began suggests the relation between TDS and specific conductance has not changed over time. Net salt gain through the Paradox Valley was estimated as the TDS load at the downstream site minus the load at the upstream site. The mean annual salt gain was 137,900 tons per year prior to operation of the PVU (1980–1993) and 43,300 tons per year after the PVU began operation (1997–2015). The difference in annual salt gain in the river between the pre-PVU and post-PVU periods was 94,600 tons per year, which represents a nearly 70 percent reduction in salt loading to the river.

  3. Optical manipulation of valley pseudospin

    DOE PAGES

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

    2016-09-19

    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,more » remained out of reach. In this paper, 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 WSe 2 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. Finally, this study unveils the possibility of generation, manipulation, and detection of the valley pseudospin by coupling to photons.« less

  4. Near Fault Strong Ground Motion Records in the Kathmandu Valley during the 2015 Gorkha Nepal Earthquake

    NASA Astrophysics Data System (ADS)

    Takai, N.; Shigefuji, M.; Rajaure, S.; Bijukchhen, S.; Ichiyanagi, M.; Dhital, M. R.; Sasatani, T.

    2015-12-01

    Kathmandu is the capital of Nepal and is located in the Kathmandu Valley, which is formed by soft lake sediments of Plio-Pleistocene origin. Large earthquakes in the past have caused significant damage as the seismic waves were amplified in the soft sediments. To understand the site effect of the valley structure, we installed continuous recording accelerometers in four different parts of the valley. Four stations were installed along a west-to-east profile of the valley at KTP (Kirtipur; hill top), TVU (Kirtipur; hill side), PTN (Patan) and THM (Thimi). On 25 April 2015, a large interplate earthquake Mw 7.8 occurred in the Himalayan Range of Nepal. The focal area estimated was about 200 km long and 150 km wide, with a large slip area under the Kathmandu Valley where our strong motion observation stations were installed. The strong ground motions were observed during this large damaging earthquake. The maximum horizontal peak ground acceleration at the rock site was 271 cm s-2, and the maximum horizontal peak ground velocity at the sediment sites reached 112 cm s-1. We compared these values with the empirical attenuation formula for strong ground motions. We found the peak accelerations were smaller and the peak velocities were approximately the same as the predicted values. The rock site KTP motions are less affected by site amplification and were analysed further. The horizontal components were rotated to the fault normal (N205E) and fault parallel (N115E) directions using the USGS fault model. The velocity waveforms at KTP showed about 5 s triangular pulses on the N205E and the up-down components; however the N115E component was not a triangular pulse but one cycle sinusoidal wave. The velocity waveforms at KTP were integrated to derive the displacement waveforms. The derived displacements at KTP are characterized by a monotonic step on the N205E normal and up-down components. The displacement waveforms of KTP show permanent displacements of 130 cm in the fault

  5. Investigation of water quality and aquatic-community structure in Village and Valley Creeks, City of Birmingham, Jefferson County, Alabama, 2000-01

    USGS Publications Warehouse

    McPherson, Ann K.; Abrahamsen, Thomas A.; Journey, Celeste A.

    2002-01-01

    The U.S. Geological Survey conducted a 16-month investigation of water quality, aquatic-community structure, bed sediment, and fish tissue in Village and Valley Creeks, two urban streams that drain areas of highly intensive residential, commercial, and industrial land use in Birmingham, Alabama. Water-quality data were collected between February 2000 and March 2001 at four sites on Village Creek, three sites on Valley Creek, and at two reference sites near Birmingham?Fivemile Creek and Little Cahaba River, both of which drain less-urbanized areas. Stream samples were analyzed for major ions, nutrients, fecal bacteria, trace and major elements, pesticides, and selected organic constituents. Bed-sediment and fish-tissue samples were analyzed for trace and major elements, pesticides, polychlorinated biphenyls, and additional organic compounds. Aquatic-community structure was evaluated by conducting one survey of the fish community and in-stream habitat and two surveys of the benthic-invertebrate community. Bed-sediment and fish-tissue samples, benthic-invertebrates, and habitat data were collected between June 2000 and October 2000 at six of the nine water-quality sites; fish communities were evaluated in April and May 2001 at the six sites where habitat and benthic-invertebrate data were collected. The occurrence and distribution of chemical constituents in the water column and bed sediment provided an initial assessment of water quality in the streams. The structure of the aquatic communities, the physical condition of the fish, and the chemical analyses of fish tissue provided an indication of the cumulative effects of water quality on the aquatic biota. Water chemistry was similar at all sites, characterized by strong calcium-bicarbonate component and magnesium components. Median concentrations of total nitrogen and total phosphorus were highest at the headwaters of Valley Creek and lowest at the reference site on Fivemile Creek. In Village Creek, median

  6. 76 FR 2711 - Cinram Distribution, LLC, a Subsidiary of Cinram International, Simi Valley Distribution Center...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-14

    ... Workers From Labor Ready Southwest, Inc. and Select Remedy Staffing Services, Simi Valley, CA; Amended..., include on-site leased workers from Labor Ready Southwest, Inc., and Select Remedy Staffing Services, Simi... Cinram International, including on-site leased workers from Labor Ready Southwest, Inc., and Select...

  7. Subsurface valleys and geoarcheology of the Eastern Sahara revealed by shuttle radar

    USGS Publications Warehouse

    McCauley, J.F.; Schaber, G.G.; Breed, C.S.; Grolier, M.J.; Haynes, C.V.; Issawi, B.; Elachi, C.; Blom, R.

    1982-01-01

    The shuttle imaging radar (SIR-A) carried on the space shuttle Columbia in November 1981 penetrated the extremely dry Selima Sand Sheet, dunes, and drift sand of the eastern Sahara, revealing previously unknown buried valleys, geologic structures, and possible Stone Age occupation sites. Radar responses from bedrock and gravel surfaces beneath windblown sand several centimeters to possibly meters thick delineate sand- and alluvium-filled valleys, some nearly as wide as the Nile Valley and perhaps as old as middle Tertiary. The nov-vanished maijor river systems that carved these large valleys probably accomplished most of the erosional stripping of this extraordinarily flat, hyperarid region. Underfit and incised dry wadis, many superimposed on the large valleys, represent erosion by intermittent running water, probably during Quaternary pluvials. Stone Age artifacts associated with soils in the alluvium suggest that areas near the wadis may have been sites of early human occupation. The presence of old drainage networks beneath the sand sheet provides a geologic explanation for the locations of many playas and present-day oases which have been centers of episodic human habitation. Radar penetration of dry sand and soils varies with the wavelength of the incident signals (24 centimeters for the SIR-A system), incidence angle, and the electrical properties of the materials, which are largely determined by moisture content. The calculated depth of radar penetration of dry sand and granules, based on laboratory measurements of the electrical properties of samples from the Selima Sand Sheet, is at least 5 meters. Recent (September 1982) field studies in Egypt verified SIR-A signal penetration depths of at least 1 meter in the Selima Sand Sheet and in drift sand and 2 or more meters in sand dunes. Copyright ?? 1982 AAAS.

  8. Deformation of ``Villafranchian'' lacustrine sediments in the Chisone Valley (Western Alps, Italy)

    NASA Astrophysics Data System (ADS)

    Collo, Giovanni; Giardino, Marco

    1997-09-01

    The Chisone Valley is located in the internal NW Alps, in the Pinerolese District, an area characterized by present low to medium seismicity. Fine-grained sediments (sand, silt and clay with interbedded gravel) crop out in the lower Chisone Valley: they were first interpreted as glaciolacustrine deposits, and then as a lacustrine infilling of the valley floor probably due to differential uplifting of the valley mouth. Review of this data, together with new field and palynological observations, lead us to refer the lacustrine deposits to approximately the Lower Pleistocene (Villafranchian). In many outcrops, the lacustrine deposits show strong soft-sediment deformation such as convolute laminations, water-escape structures and disrupted beds, some of them associated with folds and faults (cm to dm in size); only two sites show metric to decametric folds and faults trending E-W and N-S. Detailed structural analysis conducted along a recently exposed section (Rio Gran Dubbione site) shows several soft-sediment deformation features on the limbs of mesoscale folds. Because of their intimate structural association, the origin of these minor structures seems to be connected to synsedimentary activity on reverse and normal faults (m to dm in size) affecting the lacustrine deposits in the same locality. Soft-sediment deformation features can be interpreted as possible paleoseismites. If so, the present seismicity of the Pinerolese District, which is the major area of such activity in NW Italy, cannot be considered an isolated episode in the geological evolution of the region; even if there is no supporting evidence for continuous seismicity, the deformations in the lacustrine sediments of the Chisone Valley testify to Early Pleistocene seismic activity, probably related to the recent tectonic evolution of the internal side of the NW Alps.

  9. Site restoration: Estimation of attributable costs from plutonium-dispersal accidents

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chanin, D.I.; Murfin, W.B.

    1996-05-01

    A nuclear weapons accident is an extremely unlikely event due to the extensive care taken in operations. However, under some hypothetical accident conditions, plutonium might be dispersed to the environment. This would result in costs being incurred by the government to remediate the site and compensate for losses. This study is a multi-disciplinary evaluation of the potential scope of the post-accident response that includes technical factors, current and proposed legal requirements and constraints, as well as social/political factors that could influence decision making. The study provides parameters that can be used to assess economic costs for accidents postulated to occurmore » in urban areas, Midwest farmland, Western rangeland, and forest. Per-area remediation costs have been estimated, using industry-standard methods, for both expedited and extended remediation. Expedited remediation costs have been evaluated for highways, airports, and urban areas. Extended remediation costs have been evaluated for all land uses except highways and airports. The inclusion of cost estimates in risk assessments, together with the conventional estimation of doses and health effects, allows a fuller understanding of the post-accident environment. The insights obtained can be used to minimize economic risks by evaluation of operational and design alternatives, and through development of improved capabilities for accident response.« less

  10. Merging seismic and MT in Garden Valley, Nevada

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Telleen, K.E.

    1986-04-01

    In the northern part of Garden Valley, Nevada, a 1978 regional seismic program encountered a large area of poor to no-reflection data. Surface geology suggested that a large high structure might underlie the valley floor, and that shallowly buried basalts were causing the poor data. The implied strongly layered structure of electrical resistivity - resistive basalt on conductive Tertiary clastics on resistive paleozoic carbonates - formed an ideal theater for the magnetotelluric method. In 1984, Conoco acquired 48 magnetotelluric sites on about a half-mile grid. These data supported the presence of a buried high block in the Paleozoic rocks andmore » allowed confident mapping of its outlines. In addition, the magnetotelluric survey showed a thin, shallowly buried resistor coextensive with the seismic no-reflection area. In 1985, a high-effort repeat of the earlier no-reflection seismic line confirmed the high block, improved the fault interpretation, and provided weak guidance on the depth of the targeted Paleozoic rocks. Because Garden Valley's Paleozoic stratigraphy differs negligibly from that at nearby Grant Canyon field, the high block constitutes an attractive prospect - possibly the first one found in Nevada due largely to magnetotelluric surveying.« less

  11. Hinners Point Above Floor of Marathon Valley on Mars

    NASA Image and Video Library

    2015-09-25

    This Martian scene shows contrasting textures and colors of "Hinners Point," at the northern edge of "Marathon Valley," and swirling reddish zones on the valley floor to the left. The view combines six frames taken by the panoramic camera (Pancam) on NASA's Mars Exploration Rover Opportunity on Aug. 14, 2015, during the 4,108th Martian day, or sol, of the rover's work on Mars. The summit takes its informal name as a tribute to Noel Hinners (1935-2014). For NASA's Apollo program, Hinners played important roles in selection of landing sites on the moon and scientific training of astronauts. He then served as NASA associate administrator for space science, director of the Smithsonian National Air and Space Museum, director of NASA's Goddard Space Flight Center, NASA chief scientist and associate deputy administrator of NASA. Subsequent to responsibility for the Viking Mars missions while at NASA, he spent the latter part of his career as vice president for flight systems at Lockheed Martin, where he had responsibility for the company's roles in development and operation of NASA's Mars Global Surveyor, Mars Reconnaissance Orbiter, Mars Odyssey, Phoenix Mars Lander, Stardust and Genesis missions. Marathon Valley cuts generally east-west through the western rim of Endeavour Crater. The valley's name refers to the distance Opportunity drove from its 2004 landing site to arrival at this location in 2014. The valley was a high-priority destination for the rover mission because observations from orbit detected clay minerals there. Dark rocks on Hinners Point show a pattern dipping downward toward the interior of Endeavour, to the right from this viewing angle. The strong dip may have resulted from the violence of the impact event that excavated the crater. Brighter rocks make up the valley floor. The reddish zones there may be areas where water has altered composition. Inspections by Opportunity have found compositions there are higher in silica and lower in iron than the

  12. Selenium and other elements in juvenile striped bass from the San Joaquin Valley and San Francisco Estuary, California

    USGS Publications Warehouse

    Saiki, Michael K.; Palawski, Donald U.

    1990-01-01

    Concentrations of selenium and other trace elements were determined in 55 whole body samples of juvenile anadromous striped bass (Morone saxatilis) from the San Joaquin Valley and San Francisco Estuary, California. The fish (≤1 yr old—the predominant life stage in the San Joaquin Valley) were collected in September–December 1986 from 19 sites in the Valley and 3 sites in the Estuary, and analyzed for the following elements: aluminum (Al), arsenic (As), boron (B), barium (Ba), beryllium (Be), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), mercury (Hg), magnesium (Mg), molybdenum (Mo), nickel (Ni), lead (Pb), selenium (Se), strontium (Sr), vanadium (V), and zinc (Zn). When compared to concentrations in whole freshwater fish measured by surveys from other waters, a few samples contained higher levels, of As, Cd, Cu, Pb, and Se. The median concentrations of Al, As, Cu, Fe, Mg, Se, and Sr also differed significantly (P⩽0.05) among sites. However, only Se concentrations were highest (up to 7.9 μg/g dry weight) in samples from Valley sites exposed to agricultural subsurface (tile) drainwater; concentrations were lower in samples collected elsewhere. Water quality variables—especially those strongly influenced by tile drainwater (conductivity, total dissolved solids, total alkalinity, and total hardness)—were also significantly correlated (P⩽0.05) with Se concentrations in fish. Selenium concentrations in striped bass from the Estuary were only one-fourth to one-half the concentrations measured in the most contaminated fish from the San Joaquin River.

  13. NNSS Soils Monitoring: Plutonium Valley (CAU 366) FY2016

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nikolich, George; Mizell, Steve; McCurdy, Greg

    2017-10-01

    Desert Research Institute (DRI) is conducting a field assessment of the potential for contaminated soil transport from the Plutonium Valley Contamination Area (CA) as a result of wind transport and storm runoff in support of National Nuclear Security Administration (NNSA) efforts to complete regulatory closure of the contamination areas. The DRI work is intended to confirm the likely mechanism(s) of transport and determine the meteorological conditions that might cause movement of contaminated soils. The emphasis of the work is on collecting sediment transported by channelized storm runoff at the Plutonium Valley investigation sites. These data will inform closure plans thatmore » are being developed, which will facilitate the appropriate closure design and post-closure monitoring.« less

  14. Assessment of surface water quality of inland valleys for cropping in SW Nigeria

    NASA Astrophysics Data System (ADS)

    Aboyeji, O. S.; Ogunkoya, O. O.

    2017-05-01

    Inland valley agro-ecosystems which are a category of wetlands have potential for sustainable crop production relative to uplands. A major challenge to their utilisation in the study area is their heterogeneity in hydrology, morphology, soil types and agro-economy. The study assessed the surface water quality of three typologies of the agro-ecosystems—amphitheatre-like valley-heads (Am), valley-side (VS), and low depression (LD)—for cropping. Surface water of six sites were sampled during the wet and dry seasons. The physicochemical properties and metal concentrations of the samples were analysed. Descriptive statistics and water quality indices were used to assess the suitability of the waters of the agro-ecosystems for cropping. Results showed that the valleys have neutral to slightly alkaline waters. Values of physicochemical parameters are generally within the acceptable range for cropping. The concentration of major cations varied across the inland valley types, but exhibited similar characteristics within each valley. The dominance of the major cations is in the order of Na > Ca > K > Mg. ANOVA results indicated that there is no significant difference in the concentration of heavy metals across the valleys ( F = 2.044, p = 0.138, α = 0.05). Generally, most of the physicochemical parameters and trace metals have low concentrations and are non-toxic to plants. Values of water quality indices (sodium adsorption ratio, soluble sodium percentage, total dissolved solids and permeability index) indicated that the concentrations of minerals in waters across the valley typologies are generally within permissible limits for cropping.

  15. Sacramento Valley, CA, USA

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The Sacramento Valley (40.5N, 121.5W) of California is the northern extension of the Central Valley, main agriculture region of the state. Hundreds of truck farms, vineyards and orchards can be seen throughout the length and breadth of the valley which was reclaimed from the desert by means of intensive and extensive irrigation projects.

  16. LOWER RIO GRANDE VALLEY TRANSBOUNDARY AIR POLLUTION PROJECT (TAPP) (MAIN REPORT)

    EPA Science Inventory

    The purpose of the Lower Rio Grande Valley Transboundary Air Pollution Project (TAPP) was to obtain air quality data for a full year at three border monitoring sites to assess anthropogenic and biogenic emission impacts and transboundary air pollution transport in the Lower Rio...

  17. Nonlinear optical selection rule based on valley-exciton locking in monolayer ws 2

    DOE PAGES

    Xiao, Jun; Ye, Ziliang; Wang, Ying; ...

    2015-12-18

    Optical selection rules fundamentally determine the optical transitions between energy states in a variety of physical systems, from hydrogen atoms to bulk crystals such as gallium arsenide. These rules are important for optoelectronic applications such as lasers, energy-dispersive X-ray spectroscopy, and quantum computation. Recently, single-layer transition metal dichalcogenides have been found to exhibit valleys in momentum space with nontrivial Berry curvature and excitons with large binding energy. However, there has been little study of how the unique valley degree of freedom combined with the strong excitonic effect influences the nonlinear optical excitation. Here in this paper, we report the discoverymore » of nonlinear optical selection rules in monolayer WS 2, an important candidate for visible 2D optoelectronics because of its high quantum yield and large direct bandgap. We experimentally demonstrated this principle for second-harmonic generation and two-photon luminescence (TPL). Moreover, the circularly polarized TPL and the study of its dynamics evince a sub-ps interexciton relaxation (2p → 1s). The discovery of this new optical selection rule in a valleytronic 2D system not only considerably enhances knowledge in this area but also establishes a foundation for the control of optical transitions that will be crucial for valley optoelectronic device applications such as 2D valley-polarized THz sources with 2p-1s transitions, optical switches, and coherent control for quantum computing.« less

  18. Relating fish health and reproductive metrics to contaminant bioaccumulation at the Tennessee Valley Authority Kingston coal ash spill site.

    PubMed

    Pracheil, Brenda M; Marshall Adams, S; Bevelhimer, Mark S; Fortner, Allison M; Greeley, Mark S; Murphy, Cheryl A; Mathews, Teresa J; Peterson, Mark J

    2016-08-01

    A 4.1 million m(3) coal ash release into the Emory and Clinch rivers in December 2008 at the Tennessee Valley Authority's Kingston Fossil Plant in east Tennessee, USA, prompted a long-term, large-scale biological monitoring effort to determine if there are chronic effects of this spill on resident biota. Because of the magnitude of the ash spill and the potential for exposure to coal ash-associated contaminants [e.g., selenium (Se), arsenic (As), and mercury (Hg)] which are bioaccumulative and may present human and ecological risks, an integrative, bioindicator approach was used. Three species of fish were monitored-bluegill (Lepomis macrochirus), redear sunfish (L. microlophus), and largemouth bass (Micropterus salmoides)-at ash-affected and reference sites annually for 5 years following the spill. On the same individual fish, contaminant burdens were measured in various tissues, blood chemistry parameters as metrics of fish health, and various condition and reproduction indices. A multivariate statistical approach was then used to evaluate relationships between contaminant bioaccumulation and fish metrics to assess the chronic, sub-lethal effects of exposure to the complex mixture of coal ash-associated contaminants at and around the ash spill site. This study suggests that while fish tissue concentrations of some ash-associated contaminants are elevated at the spill site, there was no consistent evidence of compromised fish health linked with the spill. Further, although relationships between elevated fillet burdens of ash-associated contaminants and some fish metrics were found, these relationships were not indicative of exposure to coal ash or spill sites. The present study adds to the weight of evidence from prior studies suggesting that fish populations have not incurred significant biological effects from spilled ash at this site: findings that are relevant to the current national discussions on the safe disposal of coal ash waste.

  19. Effectiveness of the Solar Panels in the Castro Valley Unified School District Based on Projected Amount of Energy to be Produced

    NASA Astrophysics Data System (ADS)

    Sparks, J. R.; Palmer, T. C.; Siegel, A. P.

    2014-12-01

    In recent years Americans have warmed to the idea of installing solar panels to their homes and businesses. These panels help reduce the cost of receiving energy from power plants that lose a lot of energy in transportation. These power plants provide energy by burning gas or coal producing emissions that add to the growing problem of pollution and global warming. In 2010 the Castro Valley Unified School District decided to add solar panels to Canyon Middle School, Castro Valley High School, and Castro Valley Adult School. We researched whether the solar panels reached their projected amount of energy (74%) for the sites where the panels were placed. The solar panels at all three sites were found to exceed these projected amounts. The solar panels at each site produce a little over 74% for the each school.

  20. Why We Are Not Google: Lessons from a Library Web Site Usability Study

    ERIC Educational Resources Information Center

    Swanson, Troy A.; Green, Jeremy

    2011-01-01

    In the Fall of 2009, the Moraine Valley Community College Library, using guidelines developed by Jakob Nielsen, conducted a usability study to determine how students were using the library Web site and to inform the redesign of the Web site. The authors found that Moraine Valley's current gateway design was a more effective access point to library…

  1. A Progressive Black Top Hat Transformation Algorithm for Estimating Valley Volumes from DEM Data

    NASA Astrophysics Data System (ADS)

    Luo, W.; Pingel, T.; Heo, J.; Howard, A. D.

    2013-12-01

    The amount of valley incision and valley volume are important parameters in geomorphology and hydrology research, because they are related to the amount erosion (and thus the volume of sediments) and the amount of water needed to create the valley. This is not only the case for terrestrial research but also for planetary research as such figuring out how much water was on Mars. With readily available digital elevation model (DEM) data, the Black Top Hat (BTH) transformation, an image processing technique for extracting dark features on a variable background, has been applied to DEM data to extract valley depth and estimate valley volume. However, previous studies typically use one single structuring element size for extracting the valley feature and one single threshold value for removing noise, resulting in some finer features such as tributaries not being extracted and underestimation of valley volume. Inspired by similar algorithms used in LiDAR data analysis to separate above ground features and bare earth topography, here we propose a progressive BTH (PBTH) transformation algorithm, where the structuring elements size is progressively increased to extract valleys of different orders. In addition, a slope based threshold was introduced to automatically adjust the threshold values for structuring elements with different sizes. Connectivity and shape parameters of the masked regions were used to keep the long linear valleys while removing other smaller non-connected regions. Preliminary application of the PBTH to Grand Canyon and two sites on Mars has produced promising results. More testing and fine-tuning is in progress. The ultimate goal of the project is to apply the algorithm to estimate the volume of valley networks on Mars and the volume of water needed to form the valleys we observe today and thus infer the nature of the hydrologic cycle on early Mars. The project is funded by NASA's Mars Data Analysis program.

  2. A newly developed dispersal metric indicates the succession of benthic invertebrates in restored rivers.

    PubMed

    Li, Fengqing; Sundermann, Andrea; Stoll, Stefan; Haase, Peter

    2016-11-01

    Dispersal capacity plays a fundamental role in the riverine benthic invertebrate colonization of new habitats that emerges following flash floods or restoration. However, an appropriate measure of dispersal capacity for benthic invertebrates is still lacking. The dispersal of benthic invertebrates occurs mainly during the aquatic (larval) and aerial (adult) life stages, and the dispersal of each stage can be further subdivided into active and passive modes. Based on these four possible dispersal modes, we first developed a metric (which is very similar to the well-known and widely used saprobic index) to estimate the dispersal capacity for 802 benthic invertebrate taxa by incorporating a weight for each mode. Second, we tested this metric using benthic invertebrate community data from a) 23 large restored river sites with substantial improvements of river bottom habitats dating back 1 to 10years, b) 23 unrestored sites very close to the restored sites, and c) 298 adjacent surrounding sites (mean±standard deviation: 13.0±9.5 per site) within a distance of up to 5km for each restored site in the low mountain and lowland areas of Germany. We hypothesize that our metric will reflect the temporal succession process of benthic invertebrate communities colonizing the restored sites, whereas no temporal changes are expected in the unrestored and surrounding sites. By applying our metric to these three river treatment categories, we found that the average dispersal capacity of benthic invertebrate communities in the restored sites significantly decreased in the early years following restoration, whereas there were no changes in either the unrestored or the surrounding sites. After all taxa had been divided into quartiles representing weak to strong dispersers, this pattern became even more obvious; strong dispersers colonized the restored sites during the first year after restoration and then significantly decreased over time, whereas weak dispersers continued to increase

  3. Natal dispersal in the cooperatively breeding Acorn Woodpecker

    USGS Publications Warehouse

    Koenig, Walter D.; Hooge, P.N.; Stanback, M.T.; Haydock, J.

    2000-01-01

    Dispersal data are inevitably biased toward short-distance events, often highly so. We illustrate this problem using our long-term study of Acorn Woodpeckers (Melanerpes formicivorus) in central coastal California. Estimating the proportion of birds disappearing from the study area and correcting for detectability within the maximum observable distance are the first steps toward achieving a realistic estimate of dispersal distributions. Unfortunately, there is generally no objective way to determine the fates of birds not accounted for by these procedures, much less estimating the distances they may have moved. Estimated mean and root-mean-square dispersal distances range from 0.22-2.90 km for males and 0.53-9.57 km for females depending on what assumptions and corrections are made. Three field methods used to help correct for bias beyond the limits of normal study areas include surveying alternative study sites, expanding the study site (super study sites), and radio-tracking dispersers within a population. All of these methods have their limitations or can only be used in special cases. New technologies may help alleviate this problem in the near future. Until then, we urge caution in interpreting observed dispersal data from all but the most isolated of avian populations.

  4. Miscellaneous High-Resolution Seismic Imaging Investigations in Salt Lake and Utah Valleys for Earthquake Hazards

    USGS Publications Warehouse

    Stephenson, W.J.; Williams, R.A.; Odum, J.K.; Worley, D.M.

    2007-01-01

    Introduction In support of earthquake hazards and ground motion studies by researchers at the Utah Geological Survey, University of Utah, Utah State University, Brigham Young University, and San Diego State University, the U.S. Geological Survey Geologic Hazards Team Intermountain West Project conducted three high-resolution seismic imaging investigations along the Wasatch Front between September 2003 and September 2005. These three investigations include: (1) a proof-of-concept P-wave minivib reflection imaging profile in south-central Salt Lake Valley, (2) a series of seven deep (as deep as 400 m) S-wave reflection/refraction soundings using an S-wave minivib in both Salt Lake and Utah Valleys, and (3) an S-wave (and P-wave) investigation to 30 m at four sites in Utah Valley and at two previously investigated S-wave (Vs) minivib sites. In addition, we present results from a previously unpublished downhole S-wave investigation conducted at four sites in Utah Valley. The locations for each of these investigations are shown in figure 1. Coordinates for the investigation sites are listed in Table 1. With the exception of the P-wave common mid-point (CMP) reflection profile, whose end points are listed, these coordinates are for the midpoint of each velocity sounding. Vs30 and Vs100, also shown in Table 1, are defined as the average shear-wave velocities to depths of 30 and 100 m, respectively, and details of their calculation can be found in Stephenson and others (2005). The information from these studies will be incorporated into components of the urban hazards maps along the Wasatch Front being developed by the U.S. Geological Survey, Utah Geological Survey, and numerous collaborating research institutions.

  5. Seed dispersal in fens

    USGS Publications Warehouse

    Middleton, B.; Van Diggelen, R.; Jensen, K.

    2006-01-01

    Question: How does seed dispersal reduce fen isolation and contribute to biodiversity? Location: European and North American fens. Methods: This paper reviews the literature on seed dispersal to fens. Results: Landscape fragmentation may reduce dispersal opportunities thereby isolating fens and reducing genetic exchange. Species in fragmented wetlands may have lower reproductive success, which can lead to biodiversity loss. While fens may have always been relatively isolated from each other, they have become increasingly fragmented in modern times within agricultural and urban landscapes in both Europe and North America. Dispersal by water, animals and wind has been hampered by changes related to development in landscapes surrounding fens. Because the seeds of certain species are long-lived in the seed bank, frequent episodes of dispersal are not always necessary to maintain the biodiversity of fens. However, of particular concern to restoration is that some dominant species, such as the tussock sedge Carex stricta, may not disperse readily between fens. Conclusions: Knowledge of seed dispersal can be used to maintain and restore the biodiversity of fens in fragmented landscapes. Given that development has fragmented landscapes and that this situation is not likely to change, the dispersal of seeds might be enhanced by moving hay or cattle from fens to damaged sites, or by reestablishing lost hydrological connections. ?? IAVS; Opulus Press.

  6. Scaling the Morphology of Sapping and Pressurized Groundwater Experiments to Martian Valleys

    NASA Astrophysics Data System (ADS)

    Marra, W. A.; Kleinhans, M. G.

    2013-12-01

    . Groundwater flow piracy of multiple valleys within one system are characterized by equal ratios of width and length development, a property that is absent in case of a local groundwater source which does not induce flow piracy. In case of pressurized groundwater release, the sediment surface in the source area fractured and pits developed due to high groundwater pressure. The resulting valley head consisted of feather-shaped converging flow features. Scaling of the non-fluvial features that relate to groundwater pressure is possible by using hydrological modelling of groundwater pressure and geophysical modelling of the behaviour of the material under such pressures. Our results on sapping valley formation, combined with insights from multiple terrestrial sites of similar valleys contribute to the discussion of some enigmatic valleys on Mars. We provide several quantitative morphological measures, which directly relate to the formative process, which is valuable in linking morphology to the formative process. Our results on pressurized groundwater release prove a long-standing hypothesis on the formation on some of the largest valleys observed in our solar system. In both cases, the insights in the formative processes enable us to quantify the amount of water required for the formation of groundwater-induced Martian valleys.

  7. Superfund Record of Decision (EPA Region 9): San Fernando Valley Area 2, operable unit 2, Los Angeles County, CA, June 1993

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Not Available

    1993-06-01

    This decision document presents the selected remedial action for the Glendale North Operable Unit, San Fernando Valley Area 2 Superfund site. The remedy involves groundwater extraction and treatment for the shallow aquifer system in the Glendale area of the San Fernando Valley.

  8. Superfund Record of Decision (EPA Region 9): San Fernando Valley Area 2, operable unit 3, Los Angeles County, CA, June 1993

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Not Available

    1993-06-01

    This decision document presents the selected remedial action for the Glendale South Operable Unit, San Fernando Valley Area 2 Superfund site. The remedy involves groundwater extraction and treatment for the shallow aquifer system in the Glendale area of the San Fernando Valley.

  9. 75 FR 61174 - Warner Valley Comprehensive Site Plan, Final Environmental Impact Statement, Lassen Volcanic...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-04

    ... Warner Valley fen and wetland areas; (3) Removal or repair of Dream Lake Dam and restoration of... project planning area. This area includes Dream Lake Dam, built in 1932 by Alex Sifford, which impounds an... built the 10 structures which now form the core of Drakesbad Guest Ranch Historic District (both Dream...

  10. Environmental heterogeneity, dispersal mode, and co-occurrence in stream macroinvertebrates

    PubMed Central

    Heino, Jani

    2013-01-01

    Both environmental heterogeneity and mode of dispersal may affect species co-occurrence in metacommunities. Aquatic invertebrates were sampled in 20–30 streams in each of three drainage basins, differing considerably in environmental heterogeneity. Each drainage basin was further divided into two equally sized sets of sites, again differing profoundly in environmental heterogeneity. Benthic invertebrate data were divided into three groups of taxa based on overland dispersal modes: passive dispersers with aquatic adults, passive dispersers with terrestrial winged adults, and active dispersers with terrestrial winged adults. The co-occurrence of taxa in each dispersal mode group, drainage basin, and heterogeneity site subset was measured using the C-score and its standardized effect size. The probability of finding high levels of species segregation tended to increase with environmental heterogeneity across the drainage basins. These patterns were, however, contingent on both dispersal mode and drainage basin. It thus appears that environmental heterogeneity and dispersal mode interact in affecting co-occurrence in metacommunities, with passive dispersers with aquatic adults showing random patterns irrespective of environmental heterogeneity, and active dispersers with terrestrial winged adults showing increasing segregation with increasing environmental heterogeneity. PMID:23467653

  11. Sacramento Valley, CA, USA

    NASA Image and Video Library

    1973-06-22

    SL2-04-179 (22 June 1973) --- The Sacramento Valley (40.5N, 121.5W) of California is the northern extension of the Central Valley, main agriculture region of the state. Hundreds of truck farms, vineyards and orchards can be seen throughout the length and breadth of the valley which was reclaimed from the desert by means of intensive and extensive irrigation projects. Photo credit: NASA

  12. MX Siting Investigation Geotechnical Evaluation Verification Study - Cave Valley, Nevada. Volume I. Synthesis.

    DTIC Science & Technology

    1981-10-26

    areas of non- rippable materials may be encountered throughout the northwestern portion of the valley. Laboratory test results and field observations...non- rippable at shallow depths, thereby classifying them in this instance as areas of rock and/or shallow rock. When this occurs, these areas may...OCCUR- Rock is defined as any earth material which is not rippable RING WITHIN 50 FEET 015m) AND by conventional excavation methods. Where available

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

    NASA Astrophysics Data System (ADS)

    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.

  14. Atomically dispersed Ni(i) as the active site for electrochemical CO2 reduction

    NASA Astrophysics Data System (ADS)

    Yang, Hong Bin; Hung, Sung-Fu; Liu, Song; Yuan, Kaidi; Miao, Shu; Zhang, Liping; Huang, Xiang; Wang, Hsin-Yi; Cai, Weizheng; Chen, Rong; Gao, Jiajian; Yang, Xiaofeng; Chen, Wei; Huang, Yanqiang; Chen, Hao Ming; Li, Chang Ming; Zhang, Tao; Liu, Bin

    2018-02-01

    Electrochemical reduction of CO2 to chemical fuel offers a promising strategy for managing the global carbon balance, but presents challenges for chemistry due to the lack of effective electrocatalyst. Here we report atomically dispersed nickel on nitrogenated graphene as an efficient and durable electrocatalyst for CO2 reduction. Based on operando X-ray absorption and photoelectron spectroscopy measurements, the monovalent Ni(i) atomic center with a d9 electronic configuration was identified as the catalytically active site. The single-Ni-atom catalyst exhibits high intrinsic CO2 reduction activity, reaching a specific current of 350 A gcatalyst-1 and turnover frequency of 14,800 h-1 at a mild overpotential of 0.61 V for CO conversion with 97% Faradaic efficiency. The catalyst maintained 98% of its initial activity after 100 h of continuous reaction at CO formation current densities as high as 22 mA cm-2.

  15. Dry Valleys, Antarctica

    NASA Image and Video Library

    2009-11-02

    The McMurdo Dry Valleys are a row of valleys west of McMurdo Sound, Antarctica. They are so named because of their extremely low humidity and lack of snow and ice cover. This image was acquired December 8, 2002 by NASA Terra spacecraft.

  16. Superfund Record of Decision (EPA Region 9): North Hollywood/Burbank Well Field Area 1, San Fernando Valley Site, California (first remedial action), September 1987. Final report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Not Available

    1987-09-24

    The North Hollywood - Burbank Well Field (NHBWF) is located within the San Fernando Valley Ground Water basin, which can provide drinking water for approximately 500,000 people residing in the San Fernando Valley and Los Angeles. In 1980 TCE and PCE were discovered in 25% of DWP's wells. In July 1981, DWP and the Southern California Association of Governments began a two-year study funded by EPA. The study revealed the occurrence of ground-water contamination plume patterns that are spreading toward the southeast. The primary contaminant of concern to the ground-water is TCE with PCE and other VOCs present. The selectedmore » remedial action for the site is ground-water pump and treatment using aeration and granular-activated-carbon - air-filtering units, with discharge to the DWP Pumping Station for chlorination and distribution. Spent carbon will be removed and replaced with fresh carbon, with the spent carbon scheduled either for disposal or regeneration. The estimated capital cost for this remedial action is $2,192,895 with present worth OandM of $2,284,105.« less

  17. An aeromagnetic survey in the Valley of Ten Thousand Smokes, Alaska. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Anma, K.

    1971-01-01

    Geologic and magnetic studies of the Katmai area have further demonstrated the close relationship between the Katmai Caldera, Novarupta plug, and the pyroclastic flows in the Valley of Ten Thousand Smokes. The magnetic fields observed appear to be associated with the thickness of the pyroclastic flow and the different rock units within it for lower flight levels, and also the contrast between the valley fill and the rock units at the Valley margins. Consistent magnetic anomalies are associated with the larger fumarole lines, which were presumably sites of large scale activity, while the smaller fumaroles are not usually seen in the aeromagnetic map. A possible correlation between low positive anomalies and nuee ardente deposits was revealed by the aeromagnetic survey, but was not strong. A ground survey was also carried out in several parts of the Valley with a view to detailed delineation of the magnetic signatures of the pyroclastic flow, as an aid to interpreting the aeromagnetic date.

  18. Agricultural Influences on Cache Valley, Utah Air Quality During a Wintertime Inversion Episode

    NASA Astrophysics Data System (ADS)

    Silva, P. J.

    2017-12-01

    Several of northern Utah's intermountain valleys are classified as non-attainment for fine particulate matter. Past data indicate that ammonium nitrate is the major contributor to fine particles and that the gas phase ammonia concentrations are among the highest in the United States. During the 2017 Utah Winter Fine Particulate Study, USDA brought a suite of online and real-time measurement methods to sample particulate matter and potential gaseous precursors from agricultural emissions in the Cache Valley. Instruments were co-located at the State of Utah monitoring site in Smithfield, Utah from January 21st through February 12th, 2017. A Scanning mobility particle sizer (SMPS) and aerodynamic particle sizer (APS) acquired size distributions of particles from 10 nm - 10 μm in 5-min intervals. A URG ambient ion monitor (AIM) gave hourly concentrations for gas and particulate ions and a Chromatotec Trsmedor gas chromatograph obtained 10 minute measurements of gaseous sulfur species. High ammonia concentrations were detected at the Smithfield site with concentrations above 100 ppb at times, indicating a significant influence from agriculture at the sampling site. Ammonia is not the only agricultural emission elevated in Cache Valley during winter, as reduced sulfur gas concentrations of up to 20 ppb were also detected. Dimethylsulfide was the major sulfur-containing gaseous species. Analysis indicates that particle growth and particle nucleation events were both observed by the SMPS. Relationships between gas and particulate concentrations and correlations between the two will be discussed.

  19. Ground-water conditions in southern Utah Valley and Goshen Valley, Utah

    USGS Publications Warehouse

    Cordova, R.M.

    1970-01-01

    The investigation of ground-water conditions in southern Utah Valley and Goshen Valley, Utah, was made by the U. S. Geological Survey as part of a cooperative program with the Utah Department of Natural Resources, Division of Water Rights, to investigate the water resources of the State. The purposes of the investigation were to (1) determine the occurrence, recharge, discharge, movement, storage, chemical quality, and availability of ground water; (2) appraise the effects of increased withdrawal of water from wells; and (3) evaluate the effect of the Central Utah Project on the ground-water reservoir and the water supply of Utah Lake.This report presents a description of the aquifer system in the two valleys, a detailed description of the ground-water resources, and conclusions about potential development and its effect on the hydrologic conditions in the valleys. Two supplementary reports are products of the investigation. A basic-data release (Cordova, 1969) contains most of the basic data collected for the investigation, including well characteristics, drillers' logs, water levels, pumpage from wells, chemical analyses of ground and surface waters, and discharge of selected springs, drains, and streams. An interpretive report (Cordova and Mower, 1967) contains the results of a large-scale aquifer test in southern Utah Valley.

  20. Interpretive geologic cross sections for the Death Valley regional flow system and surrounding areas, Nevada and California

    USGS Publications Warehouse

    Sweetkind, D.S.; Dickerson, R.P.; Blakely, R.J.; Denning, Paul

    2001-01-01

    This report presents a network of 28 geologic cross sections that portray subsurface geologic relations within the Death Valley regional ground-water system, a ground-water basin that encompasses a 3? x 3? area (approximately 70,000 km2) in southern Nevada and eastern California. The cross sections transect that part of the southern Great Basin that includes Death Valley, the Nevada Test Site, and the potential high-level nuclear waste underground repository at Yucca Mountain. The specific geometric relationships portrayed on the cross sections are discussed in the context of four general sub-regions that have stratigraphic similarities and general consistency of structural style: (1) the Nevada Test Site vicinity; (2) the Spring Mountains, Pahrump Valley and Amargosa Desert region; (3) the Death Valley region; and (4) the area east of the Nevada Test Site. The subsurface geologic interpretations portrayed on the cross sections are based on an integration of existing geologic maps, measured stratigraphic sections, published cross sections, well data, and geophysical data and interpretations. The estimated top of pre-Cenozoic rocks in the cross sections is based on inversion of gravity data, but the deeper parts of the sections are based on geologic conceptual models and are more speculative. The region transected by the cross sections includes part of the southern Basin and Range Province, the northwest-trending Walker Lane belt, the Death Valley region, and the northern Mojave Desert. The region is structurally complex, where a locally thick Tertiary volcanic and sedimentary section unconformably overlies previously deformed Proterozoic through Paleozoic rocks. All of these rocks have been deformed by complex Neogene ex-tensional normal and strike-slip faults. These cross sections form a three-dimensional network that portrays the interpreted stratigraphic and structural relations in the region; the sections form part of the geologic framework that will be

  1. Ground-water quality in east-central Idaho valleys

    USGS Publications Warehouse

    Parliman, D.J.

    1982-01-01

    From May through November 1978, water quality, geologic, and hydrologic data were collected for 108 wells in the Lemhi, Pahsimeroi, Salman River (Stanley to Salmon), Big Lost River, and Little Lost River valleys in east-central Idaho. Data were assembled to define, on a reconnaissance level, water-quality conditions in major aquifers and to develop an understanding of factors that affected conditions in 1978 and could affect future ground-water quality. Water-quality characteristics determined include specific conductance, pH, water temperature, major dissolved cations, major dissolved anions, and coliform bacteria. Concentrations of hardness, nitrite plus nitrate, coliform bacteria, dissolved solids, sulfate, chloride, fluoride , iron, calcium, magnesium, sodium, potassium or bicarbonate exceed public drinking water regulation limits or were anomalously high in some water samples. Highly mineralized ground water probably is due to the natural composition of the aquifers and not to surface contamination. Concentrations of coliform bacteria that exceed public drinking water limits and anomalously high dissolved nitrite-plus-nitrite concentrations are from 15- to 20-year old irrigation wells in heavily irrigated or more densely populated areas of the valleys. Ground-water quality and quantity in most of the study area are sufficient to meet current (1978) population and economic demands. Ground water in all valleys is characterized by significant concentrations of calcium, magnesium, and bicarbonate plus carbonate ions. Variations in the general trend of ground-water composition (especially in the Lemhi Valley) probably are most directly related to variability in aquifer lithology and proximity of sampling site to source of recharge. (USGS)

  2. Mapping Ecosystem Services in the Jordan Valley, Jordan

    NASA Astrophysics Data System (ADS)

    Luz, Ana; Marques, Ana; Ribeiro, Inês; Alho, Maria; Catarina Afonso, Ana; Almeida, Erika; Branquinho, Cristina; Talozi, Samer; Pinho, Pedro

    2016-04-01

    In the last decade researchers started using ecosystem services as a new framework to understand the relationships between environment and society. Habitat quality and water quality are related with ecosystem services regulation and maintenance, or even provision. According to the Common International Classification of Ecosystem Services (CICES) both habitat quality and water quality are associated with lifecycle maintenance, habitat and gene pool protection, and water conditions, among others. As there is increased pressure on habitats and rivers especially for agricultural development, mapping and evaluating habitat and water quality has important implications for resource management and conservation, as well as for rural development. Here, we model and map habitat and water quality in the Jordan Valley, Jordan. In this study, we aim to identify and analyse ecosystem services both through 1) habitat quality and 2) water quality modelling using InVest, an integrated valuation of ecosystem services and tradeoffs. The data used in this study mainly includes the LULC, Jordan River watershed and main threats and pollutants in the study area, such as agriculture, industry, fish farms and urbanization. Results suggest a higher pressure on natural habitats in the Northern region of the Jordan Valley, where industry is dominant. Agriculture is present along the Jordan Valley and limits the few natural forested areas. Further, water pollution is mainly concentrated in disposal sites due to the low flow of the Jordan River. Our results can help to identify areas where natural resources and water resource management is most needed in the Jordan Valley. Acknowledgements: Transbasin FP7 project

  3. Design and experimental observation of valley-Hall edge states in diatomic-graphene-like elastic waveguides

    NASA Astrophysics Data System (ADS)

    Zhu, Hongfei; Liu, Ting-Wei; Semperlotti, Fabio

    2018-05-01

    We report on the design and experimental validation of a two-dimensional phononic elastic waveguide exhibiting topological valley-Hall edge states. The lattice structure of the waveguide is inspired by diatomic graphene, and it is imprinted in an initially flat plate by means of geometric indentations. The indentations are distributed according to a hexagonal lattice structure which guarantees the existence of Dirac dispersion at the boundary of the Brillouin zone. Starting from this basic material, domain walls capable of supporting edge states can be obtained by contrasting waveguides having broken space-inversion symmetry (SIS) achieved by using local resonant elements. Our theoretical study shows that such material maps into the acoustic analog of the quantum valley-Hall effect, while numerical and experimental results confirm the existence of protected edge states traveling along the walls of topologically distinct domains.

  4. Hinners Point Above Floor of Marathon Valley on Mars Enhanced Color

    NASA Image and Video Library

    2015-09-25

    This Martian scene shows contrasting textures and colors of "Hinners Point," at the northern edge of "Marathon Valley," and swirling reddish zones on the valley floor to the left. In this version of the image, the landscape is presented in enhanced color to make differences in surface materials more easily visible. The summit takes its informal name as a tribute to Noel Hinners (1935-2014). For NASA's Apollo program, Hinners played important roles in selection of landing sites on the moon and scientific training of astronauts. He then served as NASA associate administrator for space science, director of the Smithsonian National Air and Space Museum, director of NASA's Goddard Space Flight Center, NASA chief scientist and associate deputy administrator of NASA. Subsequent to responsibility for the Viking Mars missions while at NASA, he spent the latter part of his career as vice president for flight systems at Lockheed Martin, where he had responsibility for the company's roles in development and operation of NASA's Mars Global Surveyor, Mars Reconnaissance Orbiter, Mars Odyssey, Phoenix Mars Lander, Stardust and Genesis missions. Marathon Valley cuts generally east-west through the western rim of Endeavour Crater. The valley's name refers to the distance Opportunity drove from its 2004 landing site to arrival at this location in 2014. The valley was a high-priority destination for the rover mission because observations from orbit detected clay minerals there. Dark rocks on Hinners Point show a pattern dipping downward toward the interior of Endeavour, to the right from this viewing angle. The strong dip may have resulted from the violence of the impact event that excavated the crater. Brighter rocks make up the valley floor. The reddish zones there may be areas where water has altered composition. Inspections by Opportunity have found compositions there are higher in silica and lower in iron than the typical composition of rocks on Endeavour's rim. The scene spans

  5. Seed dispersal at alpine treeline: long distance dispersal maintains alpine treelines

    NASA Astrophysics Data System (ADS)

    Johnson, J. S.; Gaddis, K. D.; Cairns, D. M.; Krutovsky, K.

    2016-12-01

    Alpine treelines are expected to advance to higher elevations in conjunction with global warming. Nevertheless, the importance of reproductive method and seed dispersal distances at the alpine treeline ecotone remains unresolved. We address two research questions at mountain hemlock treelines on the Kenai Peninsula, Alaska: (1) What is the primary mode of reproduction, and (2) are recruits derived from local treeline populations or are they arriving from more distant seed sources? We addressed our research questions by exhaustively sampling mountain hemlock individuals along a single mountain slope and then genotyped DNA single nucleotide polymorphisms using a genotyping by sequencing approach (ddRAD Seq). First we assessed mode of reproduction by determining the proportion of sampled individuals with identical multilocus genotypes that are the product of clonal reproduction. Second, we used a categorical allocation based parentage analysis to identify parent-offspring pairs, so that the proportion of treeline reproduction events could be quantified spatially and dispersal distance measured. We identified sexual reproduction as the primary mode of reproduction at our study site. Seedling establishment was characterized by extensive cryptic seed dispersal and gene flow into the ecotone. The average dispersal distance was 73 meters with long distance dispersal identified as dispersal occurring at distances greater than 450 meters. We show that production of seeds within the alpine treeline ecotone is not a necessary requirement for treelines to advance to higher elevations in response to climate change. The extensive cryptic seed dispersal and gene flow into the alpine treeline ecotone is likely sufficient to propel the ecotone higher under more favorable climate.

  6. The effects of site, supplemental food, and age on survivorship of Carolina Chickadees and implications for dispersal through- riparian corridors

    USGS Publications Warehouse

    Doherty, P.F.; Grubb, T.G.

    2000-01-01

    Few studies have examined survivorship of animals in forest fragments differing in size, and none has used appropriate mark-recapture analysis techniques taking into account probability of recapture. Using Program MARK, a flexible mark-recapture software package, we estimated annual survival rates of Carolina Chickadees over a 5-yr period in a fragmented landscape in Ohio. The probability of survival was related to site (riparian woodland or woodlot area) and increased with the presence of supplemental food. While there was little evidence for an age difference in apparent survival in woodlots, young birds appeared to survive less well in forested river corridors. This last result was quite likely due, at least in part, to age-specific dispersal, suggesting that river corridors function as important dispersal routes for young birds.

  7. Analysis of Mining-induced Valley Closure Movements

    NASA Astrophysics Data System (ADS)

    Zhang, C.; Mitra, R.; Oh, J.; Hebblewhite, B.

    2016-05-01

    Valley closure movements have been observed for decades in Australia and overseas when underground mining occurred beneath or in close proximity to valleys and other forms of irregular topographies. Valley closure is defined as the inward movements of the valley sides towards the valley centreline. Due to the complexity of the local geology and the interplay between several geological, topographical and mining factors, the underlying mechanisms that actually cause this behaviour are not completely understood. A comprehensive programme of numerical modelling investigations has been carried out to further evaluate and quantify the influence of a number of these mining and geological factors and their inter-relationships. The factors investigated in this paper include longwall positional factors, horizontal stress, panel width, depth of cover and geological structures around the valley. It is found that mining in a series passing beneath the valley dramatically increases valley closure, and mining parallel to valley induces much more closure than other mining orientations. The redistribution of horizontal stress and influence of mining activity have also been recognised as important factors promoting valley closure, and the effect of geological structure around the valley is found to be relatively small. This paper provides further insight into both the valley closure mechanisms and how these mechanisms should be considered in valley closure prediction models.

  8. The Inter-Valley Soil Comparative Survey: the ecology of Dry Valley edaphic microbial communities

    PubMed Central

    Lee, Charles K; Barbier, Béatrice A; Bottos, Eric M; McDonald, Ian R; Cary, Stephen Craig

    2012-01-01

    Recent applications of molecular genetics to edaphic microbial communities of the McMurdo Dry Valleys and elsewhere have rejected a long-held belief that Antarctic soils contain extremely limited microbial diversity. The Inter-Valley Soil Comparative Survey aims to elucidate the factors shaping these unique microbial communities and their biogeography by integrating molecular genetic approaches with biogeochemical analyses. Although the microbial communities of Dry Valley soils may be complex, there is little doubt that the ecosystem's food web is relatively simple, and evidence suggests that physicochemical conditions may have the dominant role in shaping microbial communities. To examine this hypothesis, bacterial communities from representative soil samples collected in four geographically disparate Dry Valleys were analyzed using molecular genetic tools, including pyrosequencing of 16S rRNA gene PCR amplicons. Results show that the four communities are structurally and phylogenetically distinct, and possess significantly different levels of diversity. Strikingly, only 2 of 214 phylotypes were found in all four valleys, challenging a widespread assumption that the microbiota of the Dry Valleys is composed of a few cosmopolitan species. Analysis of soil geochemical properties indicated that salt content, alongside altitude and Cu2+, was significantly correlated with differences in microbial communities. Our results indicate that the microbial ecology of Dry Valley soils is highly localized and that physicochemical factors potentially have major roles in shaping the microbiology of ice-free areas of Antarctica. These findings hint at links between Dry Valley glacial geomorphology and microbial ecology, and raise previously unrecognized issues related to environmental management of this unique ecosystem. PMID:22170424

  9. 27 CFR 9.132 - Rogue Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Rogue Valley. 9.132... Rogue Valley. (a) Name. The name of the viticultural area described in this section is “Rouge Valley.” (b) Approved map. The appropriate map for determining the boundaries of the Rogue Valley viticultural...

  10. Soil-plant abstract of heavy metals in Pb-Zn mining sites from Alcudia Valley (South Spain)

    NASA Astrophysics Data System (ADS)

    López-Berdonces, Miguel; Higueras, Pablo; Esbrí, Jose Maria; González-Corrochano, Beatríz; García-Noguero, Eva Mª; Martínez-Coronado, Alba; Fernandez-Calderón, Sergio; García-Noguero, Carolina

    2013-04-01

    Soil-plant transfer of heavy metals in Pb-Zn mining sites from Alcudia Valley (South Spain). Authors: Miguel A. López-Berdonces¹; Pablo Higueras¹; Jose María Esbrí¹; Beatriz González-Corrochano¹; Eva Mª García- Noguero¹; Alba Martínez Coronado¹; Sergio Fernández-Calderón¹; Carolina García-Noguero¹ ¹Instituto de Geología Aplicada, Universidad Castilla la Mancha, Pza. Manuel Meca, 1. 13400 Almadén, Spain. Alcudia Valley is a vast territory recently declared Natural Park, located in South of Spain. It is an area rich in mineral deposits of Zn and Pb and mining exists since the first millennium BC., having its highest ore production between mid-nineteenth century and the middle of the twentieth. This area has been selected because has more than 120 abandoned mines without remediation actions, with dumps and tailings with high contents of zinc and lead sulfides, and Cu, Ag, Cd, As, Sb in minor concentrations. In this study we determinate the transfer rate of these metals from soils to plants represented by oak leaves (Quercus ilex), because this specie is common within the selected area. To evaluate the soil-plant transfer were studied the correlation of contents, total and extractable, in soil-leaves. Extractable fraction was done by for different methods in water, EPA 1312 sulfuric acid: nitric acid 60:40 v., Ammonium Acetate and EDTA. To establish the correlation between heavy metals from soils to plants is necessary to know the contents of these and bioavailable content in soil. Three areas (S. Quintín, Romanilla, Bombita) were selected, taking 24 samples of soils and leaves. Analyzed leaves by XRF showed that Mn, Pb, Zn and Mo in S.Quintin and Romanilla, Mn, Pb in Bombita, exceeded the toxicity threshold. The same samples analyzed by ICP show us the toxicity threshold is exceeded Pb, Zn and Hg in S.Quintin, and Pb in Romanilla. The heavy metal content in leaves compared between two techniques analytical gives an acceptable correlation Zn - Pb

  11. Ant-mediated seed dispersal in a warmed world

    PubMed Central

    Patterson, Courtney M.; Rodriguez-Cabal, Mariano A.; Ribbons, Relena R.; Dunn, Robert R.; Sanders, Nathan J.

    2014-01-01

    Climate change affects communities both directly and indirectly via changes in interspecific interactions. One such interaction that may be altered under climate change is the ant-plant seed dispersal mutualism common in deciduous forests of eastern North America. As climatic warming alters the abundance and activity levels of ants, the potential exists for shifts in rates of ant-mediated seed dispersal. We used an experimental temperature manipulation at two sites in the eastern US (Harvard Forest in Massachusetts and Duke Forest in North Carolina) to examine the potential impacts of climatic warming on overall rates of seed dispersal (using Asarum canadense seeds) as well as species-specific rates of seed dispersal at the Duke Forest site. We also examined the relationship between ant critical thermal maxima (CTmax) and the mean seed removal temperature for each ant species. We found that seed removal rates did not change as a result of experimental warming at either study site, nor were there any changes in species-specific rates of seed dispersal. There was, however, a positive relationship between CTmax and mean seed removal temperature, whereby species with higher CTmax removed more seeds at hotter temperatures. The temperature at which seeds were removed was influenced by experimental warming as well as diurnal and day-to-day fluctuations in temperature. Taken together, our results suggest that while temperature may play a role in regulating seed removal by ants, ant plant seed-dispersal mutualisms may be more robust to climate change than currently assumed. PMID:24688863

  12. Seasonal and diurnal variations of methane and carbon dioxide in the highly polluted Kathmandu Valley, Nepal

    NASA Astrophysics Data System (ADS)

    Mahata, Khadak; Panday, Arnico; Rupakheti, Maheswar; Lawrence, Mark

    2016-04-01

    Anthropogenic emissions of carbon dioxide and methane - key greenhouse gases (GHGs) - are primary causes of global warming and resultant impacts. The atmospheric warming is more pronounced and likely to cause more serious damage in vulnerable areas such as the Hindukush-Karakorum-Himalayan region (HKH). The HKH region is a data gap region according to the 5th Assessment report of the intergovernmental panel on climate change (IPCC). In order to understand the mixing ratios and variability of the key GHGs in the foothills of the Central Himalaya, we carried out continuous measurements of CO2, CH4, CO, and water vapor at Bode (an urban site in the Kathmandu valley, Nepal) for a year (March 2013 - Feb 2014), and again at Bode and at Chanban (a background outside the Valley) for 3 months (July 15 - Oct 3, 2015), with two state-of-the-art cavity ring-down instruments (Picarro G2401). The measurements were carried out as a part of the international air pollution measurement campaign: SusKat- ABC (Sustainable atmosphere for the Kathmandu Valley - Atmospheric Brown Clouds). The annual average CO2 and CH4 concentrations at Bode were 419 ± 24 and 2.192 ± 0.224 ppm, respectively, which are notably higher than those observed at the background site at Mauna Loa Observatory in the same period. The CO2concentration at Bode was high during the pre-monsoon period and low during the monsoon, while CH4 was high in winter and lower during the pre-monsoon period. The monthly CO2concentration was highest in April. Forest fires and agro-waste burning in the region, and the local emissions in the Kathmandu valley were the main sources of the high CO2 in the pre-monsoon period. CH4 showed a maximum in September due to additional emissions from paddy fields. Seasonally, winter has the highest CH4 concentration which is due to brick production, which is a seasonal activity, and other local sources combined with the shallow mixing layer height in winter. The diurnal pattern of CO2 and CH4

  13. Wintertime Ambient Ammonia Concentrations in Northern Utah's Urban Valleys

    NASA Astrophysics Data System (ADS)

    Hammond, I. A.; Martin, R. S.; Silva, P.; Baasandorj, M.

    2017-12-01

    Many of the population centers in northern Utah are currently classified as non-attainment or serious non-attainment, Wasatch Front, for PM2.5 and previous studies have shown ammonium nitrate to often be the largest contributor to the particulate mass. Furthermore, measurements have shown several of the Wasatch Front cities and Cache Valley (UT/ID) consistently recorded some of the highest ambient ammonia (NH3) concentrations in the continental United States. As a part of the multi-organization 2017 Utah Winter Fine Particulate Study real-time NH3 concentrations were monitored in the Cache Valley at the Logan, UT site, collocated at an EPA sampling trailer near the Utah State University (USU) campus. A Picarro model G2508 was to used collect 5-sec averaged concentrations of NH3, carbon dioxide (CO2), and methane (CH4) from January 16th to February 14th, 2017. Parts of three inversion events, wherein the PM2.5 concentrations approached or exceeded the National Ambient Air Quality Standards, were captured during the sampling period, including a 10-day event from January 25th to February 4th. Concentrations of all three of the observed species showed significant accumulation during the events, with NH3 concentrations ranging from below the detection limit (<0.5 ppb) to >70 ppb. Preliminary analysis suggested the temporal NH3 changes tracked the increase in PM2.5 throughout the inversion events; however, a one-day period of NH3 depletion during the main inversion event was observed while PM2.5 continued to increase. Additionally, a network of passive NH3 samplers (Ogawa Model 3300) were arrayed at 25 sites throughout the Cache Valley and at 11 sites located along the Wasatch Front. These networks sampled for three 7-day periods, during the same study time frame. Ion chromatographic (IC) analyses of the sample pads are not yet finalized; however, preliminary results show concentrations in the tens of ppb and seemingly spatially correlate with previous studies showing

  14. The Effects of Mountaintop Mines and Valley Fills on Aquatic ...

    EPA Pesticide Factsheets

    EPA announced the availability of the final report, The Effects of Mountaintop Mines and Valley Fills on Aquatic Ecosystems of the Central Appalachian Coalfields. This report assesses the state of the science on the environmental impacts of mountaintop mines and valley fills (MTM-VF) on streams in the central Appalachian coalfields. These coalfields cover about 48,000 square kilometers (122 million acres) in West Virginia, Kentucky, Virginia and Tennessee, USA. Our reviews focused on the impacts on mountaintop removal coal mining, which as its name suggests, involves removing all or some portion of the top of a mountain or ridge to expose and mine one or more coal seams. The excess overburden is disposed of in constructed fills in small valleys or hollows adjacent to the mining site. Our conclusions, based on evidence from the peer-reviewed literature and from the U.S. Environmental Protection Agency's Programmatic Environmental Impact Statement released in 2005, are that mountaintop mines and valley fills lead directly to five principal alterations of stream ecosystems: springs and ephemeral, intermittent and perennial streams are permanently lost with the removal of the mountain and from burial under fill, concentrations of major chemical ions are persistently elevated downstream, degraded water quality reaches levels that are acutely lethal to organisms in standard aquatic toxicity tests, selenium concentrations are elevated, reaching concentrations t

  15. Appraisal of the water resources of Death Valley, California-Nevada

    USGS Publications Warehouse

    Miller, Glenn Allen

    1977-01-01

    The hydrologic system in Death Valley is probably in a steady-state condition--that is, recharge and discharge are equal, and net changes in the quantity of ground water in storage are not occurring. Recharge to ground water in the valley is derived from interbasin underflow and from local precipitation. The two sources may be of the same magnitude. Ground water beneath the valley moves toward the lowest area, a 200-square-mile saltpan, much of which is underlain by rock salt and other saline minerals, probably to depths of hundreds of feet or even more than 1,000 feet. Some water discharges from the saltpan by evaportranspiration. Water beneath the valley floor, excluding the saltpan, typically contains between 3,000 and 5,000 milligrams per liter of dissolved solids. Water from most springs and seeps in the mountains contains a few hundred to several hundred milligrams per liter of dissolved solids. Water from large springs that probably discharge from interbasin flow systems typically contains between 500 and 1,000 milligrams per liter dissolved solids. Present sites of intensive use by man are supplied by springs, with the exception of the Stovepipe Wells Hotel area. Potential sources of supply for this area include (1) Emigrant Spring area, (2) Cottonwood Spring, and (3) northern Mesquite Flat. (Woodard-USGS)

  16. Hydrologic and hydraulic analyses at Akin Branch and Cayce Valley Branch, Columbia, Tennessee

    USGS Publications Warehouse

    Outlaw, George S.

    1993-01-01

    The U.S. Geological Survey, in cooperation with the City of Columbia, Tennessee, conducted hydrologic and hydraulic analyses at Akin Branch and Cayce Valley Branch in the Little Bigby Creek watershed, Columbia, Tennessee, from 1990 through 1991. Results of the analyses can be used by city planners in the development of plans to replace several deteriorating and inadequate drainage structures. Akin Branch and Cayce Valley Branch drain small watersheds of 1.69 and 1.04 square miles, respectively. Flood discharges for 5-, lo-, and 25-year recurrence-interval storm events were calculated at the stream mouths using flood-frequency relations developed for use at small urban streams in Tennessee. For each stream, flood discharges at locations upstream from the mouth were calculated by subdividing the watershed and assigning a percentage of the discharge at the mouth, based on drainage area, to each subarea. Flood profiles for the selected recurrence-interval flood discharges were simulated for Akin Branch and Cayce Valley Branch for existing conditions and conditions that might exist if drainage improvements such as larger culverts and bridges and channel improvements are constructed. The results of the simulations were used to predict changes in flood elevations that might result from such drainage improvements. Analyses indicate that reductions in existing flood elevations of as much as 2.1 feet for the 5-year flood at some sites on Akin Branch and as much as 3.8 feet for the 5-year flood at some sites on Cayce Valley Branch might be expected with the drainage improvements.

  17. Ground-water modeling of the Death Valley Region, Nevada and California

    USGS Publications Warehouse

    Belcher, W.R.; Faunt, C.C.; Sweetkind, D.S.; Blainey, J.B.; San Juan, C. A.; Laczniak, R.J.; Hill, M.C.

    2006-01-01

    The Death Valley regional ground-water flow system (DVRFS) of southern Nevada and eastern California covers an area of about 100,000 square kilometers and contains very complex geology and hydrology. Using a computer model to represent the complex system, the U.S. Geological Survey simulated ground-water flow in the Death Valley region for use with U.S. Department of Energy projects in southern Nevada. The model was created to help address contaminant cleanup activities associated with the underground nuclear testing conducted from 1951 to 1992 at the Nevada Test Site and to support the licensing process for the proposed geologic repository for high-level nuclear waste at Yucca Mountain, Nevada.

  18. Basin-floor Lake Bonneville stratigraphic section as revealed in paleoseismic trenches at the Baileys Lake site, West Valley fault zone, Utah

    USGS Publications Warehouse

    Hylland, Michael D.; DuRoss, Christopher B.; McDonald, Greg N.; Olig, Susan S.; Oviatt, Charles G.; Mahan, Shannon; Crone, Anthony J.; Personius, Stephen

    2012-01-01

     Recent paleoseismic trenching on the Granger fault of the West Valley fault zone in Salt Lake County, Utah, exposed a nearly complete section of late Pleistocene Lake Bonneville deposits, and highlights challenges related to accurate interpretation of basin-floor stratigraphy in the absence of numerical age constraints. We used radiocarbon and luminescence dating as well as ostracode biostratigraphy to provide chronostratigraphic control on the Lake Bonneville section exposed at the Baileys Lake trench site. The fault trenches exposed folded and faulted pre- to post- Bonneville sediments, including about 0.7 m of pre-Bonneville wetland/fluvial-marsh deposits, a nearly complete Bonneville section 2.5–4.0 m thick, and 0.4–1.0 m of post-Bonneville deposits consisting primarily of loess with minor scarp-derived colluvium. The relatively thin Bonneville section compares favorably with basin-floor Bonneville sections documented in boreholes and seismic reflection profiles beneath Great Salt Lake. Distinctive features of the Bonneville section at the Baileys Lake site include a sequence of turbidites in the upper part of the Bonneville transgressive deposits, evidence for an earthquake during Provo-shoreline time that disturbed lake-bottom sediments and destroyed any stratigraphic signature of the Bonneville Flood, tufa deposition associated with Gilbert-phase shoreline transgression, and stratigraphic evidence for two Gilbert transgressions across the site.

  19. Hydrogeology and water quality of the West Valley Creek Basin, Chester County, Pennsylvania

    USGS Publications Warehouse

    Senior, Lisa A.; Sloto, Ronald A.; Reif, Andrew G.

    1997-01-01

    .5 inches in 1990 and 13.7 inches in 1991. Ground-water quality in the basin reflects differences in lithology and has been affected by human activities. Ground water in the carbonate rocks is naturally hard, has a near neutral pH, and contains more dissolved solids and less dissolved iron, manganese, and radon-222 than ground water in the noncarbonate rocks, which is soft, with moderately acidic to acidic pH. Regional contamination by chloride and nitrate and local contamination by organic compounds and metals was detected. Natural background concentrations are estimated to be about 1 milligram per liter for nitrate as nitrogen and less than 3 milligrams per liter for chloride. Ground water in unsewered areas and agricultural areas of the basin has median concentrations of nitrate that are greater than those in ground water from other areas; septic system effluent and fertilizer are probable sources of elevated nitrate. Water samples from wells in urbanized areas contain greater concentrations of chloride than samples from wells in residential areas; road salt is the probable source of elevated chloride. Organic solvents, especially trichloroethylene, were detected in 30 percent of the wells sampled in the urbanized carbonate valley. Most of the organic solvents and some of the metals in ground water were detected near old industrial sites.Base-flow stream quality of West Valley Creek was determined at 15 sites from monthly sampling for 1 year. Differences in stream quality reflect differences in lithology, land use, and point sources in tributary subbasins and mainstem reaches. The chemical composition of base flow in the mainstem is dominated by ground-water discharge from carbonate rocks. Elevated concentrations of nitrate (greater than 3 milligrams per liter as nitrogen) in base flow were measured in a tributary draining agricultural land and in a tributary draining an unsewered residential area. Elevated concentrations of phosphate (greater than 0.5 milligrams per

  20. Luminescence dating of anthropogenic features of the San Luis Valley, Colorado: from stone huts to stone walls

    USGS Publications Warehouse

    Mahan, Shannon; Donlan, Rebecca A.; Kardos, Barbara Maat

    2015-01-01

    The Snake Nest Wall site and the Crestone Stone Huts are in the northern San Luis Valley, Colorado, and provide a unique opportunity to date high-altitude archeological sites of unknown age and origin using optically stimulated luminescence (OSL). We sampled sediment underlying foundation stones of these structures to establish a chronological framework for each site's construction. OSL dating of the quartz grains directly under the Snake Nest Wall suggest that the stones and, therefore, the structure was most recently emplaced between 1855 and 1890 A.D. Dating of the sediment beneath the Crestone Stone Huts suggests the construction time of these huts is between 1860 and 1890 A.D. Analysis of the equivalent dose (DE) dispersion of the OSL samples at Snake Nest Wall and the Crestone Huts shows that the majority of sediments were fully bleached prior to deposition and the low scatter suggests that short-term or shallow alluvial processes were the dominant transport for sediments. In both cases, the OSL ages show that the construction was during very recent historical times, although it is likely that the Snake Nest Wall was rebuilt in the late 19th century. Further study is warranted at the Snake Nest Wall since it shows signs of greater antiquity and a continued presence of human use. The Crestone Huts are shown to be a product of railroad building during the boomtown days of Lucky and Crestone.

  1. Hydrogeologic framework and estimates of groundwater storage for the Hualapai Valley, Detrital Valley, and Sacramento Valley basins, Mohave County, Arizona

    USGS Publications Warehouse

    Truini, Margot; Beard, L. Sue; Kennedy, Jeffrey; Anning, Dave W.

    2013-01-01

    We have investigated the hydrogeology of the Hualapai Valley, Detrital Valley, and Sacramento Valley basins of Mohave County in northwestern Arizona to develop a better understanding of groundwater storage within the basin fill aquifers. In our investigation we used geologic maps, well-log data, and geophysical surveys to delineate the sedimentary textures and lithology of the basin fill. We used gravity data to construct a basin geometry model that defines smaller subbasins within the larger basins, and airborne transient-electromagnetic modeled results along with well-log lithology data to infer the subsurface distribution of basin fill within the subbasins. Hydrogeologic units (HGUs) are delineated within the subbasins on the basis of the inferred lithology of saturated basin fill. We used the extent and size of HGUs to estimate groundwater storage to depths of 400 meters (m) below land surface (bls). The basin geometry model for the Hualapai Valley basin consists of three subbasins: the Kingman, Hualapai, and southern Gregg subbasins. In the Kingman subbasin, which is estimated to be 1,200 m deep, saturated basin fill consists of a mixture of fine- to coarse-grained sedimentary deposits. The Hualapai subbasin, which is the largest of the subbasins, contains a thick halite body from about 400 m to about 4,300 m bls. Saturated basin fill overlying the salt body consists predominately of fine-grained older playa deposits. In the southern Gregg subbasin, which is estimated to be 1,400 m deep, saturated basin fill is interpreted to consist primarily of fine- to coarse-grained sedimentary deposits. Groundwater storage to 400 m bls in the Hualapai Valley basin is estimated to be 14.1 cubic kilometers (km3). The basin geometry model for the Detrital Valley basin consists of three subbasins: northern Detrital, central Detrital, and southern Detrital subbasins. The northern and central Detrital subbasins are characterized by a predominance of playa evaporite and fine

  2. 31 flavors to 50 shades of grey: battling Phytophthoras in native habitats managed by the Santa Clara Valley Water District

    Treesearch

    Janet Hillman; Tedmund J. Swiecki; Elizabeth A. Bernhardt; Heather K. Mehl; Tyler B. Bourret; David Rizzo

    2017-01-01

    The Santa Clara Valley Water District (District) is a wholesale water supplier for 1.8 million people in Santa Clara County, California. Capital, water utility, and stream maintenance projects result in extensive, long-term mitigation requirements in riparian, wetland, and upland habitats throughout the county. In 2014, several restoration sites on the valley floor and...

  3. Dispersion in deep polar firn driven by synoptic-scale surface pressure variability

    NASA Astrophysics Data System (ADS)

    Buizert, Christo; Severinghaus, Jeffrey P.

    2016-09-01

    Commonly, three mechanisms of firn air transport are distinguished: molecular diffusion, advection, and near-surface convective mixing. Here we identify and describe a fourth mechanism, namely dispersion driven by synoptic-scale surface pressure variability (or barometric pumping). We use published gas chromatography experiments on firn samples to derive the along-flow dispersivity of firn, and combine this dispersivity with a dynamical air pressure propagation model forced by surface air pressure time series to estimate the magnitude of dispersive mixing in the firn. We show that dispersion dominates mixing within the firn lock-in zone. Trace gas concentrations measured in firn air samples from various polar sites confirm that dispersive mixing occurs. Including dispersive mixing in a firn air transport model suggests that our theoretical estimates have the correct order of magnitude, yet may overestimate the true dispersion. We further show that strong barometric pumping, such as at the Law Dome site, may reduce the gravitational enrichment of δ15N-N2 and other tracers below gravitational equilibrium, questioning the traditional definition of the lock-in depth as the depth where δ15N enrichment ceases. Last, we propose that 86Kr excess may act as a proxy for past synoptic activity (or paleo-storminess) at the site.

  4. Data network, collection, and analysis in the Diamond Valley flow system, central Nevada

    USGS Publications Warehouse

    Knochenmus, Lari A.; Berger, David L.; Moreo, Michael T.; Smith, J. LaRue

    2011-01-01

    Future groundwater development and its effect on future municipal, irrigation, and alternative energy uses in the Diamond Valley flow system are of concern for officials in Eureka County, Nevada. To provide a better understanding of the groundwater resources, the U.S. Geological Survey, in cooperation with Eureka County, commenced a multi-phase study of the Diamond Valley flow system in 2005. Groundwater development primarily in southern Diamond Valley has resulted in water-level declines since the 1960s ranging from less than 5 to 100 feet. Groundwater resources in the Diamond Valley flow system outside of southern Diamond Valley have been relatively undeveloped. Data collected during phase 2 of the study (2006-09) included micrometeorological data at 4 evapotranspiration stations, 3 located in natural vegetation and 1 located in an agricultural field; groundwater levels in 95 wells; water-quality constituents in aquifers and springs at 21 locations; lithologic information from 7 recently drilled wells; and geophysical logs from 3 well sites. This report describes what was accomplished during phase 2 of the study, provides the data collected, and presents the approaches to strengthen relations between evapotranspiration rates measured at micrometeorological stations and spatially distributed groundwater discharge. This report also presents the approach to improve delineation of areas of groundwater discharge and describes the current methodology used to improve the accuracy of spatially distributed groundwater discharge rates in the Diamond Valley flow system.

  5. MX Siting Investigation. Water Resources Program. Volume II. Review Draft, Water Appropriations Hearing Presentation and Support Documentation, Dry Lake Valley, Nevada.

    DTIC Science & Technology

    1981-09-30

    will be required to de - liver the 651 gpm (41 l/s) needed for peak water use at the LSC. The existing Air Force test well at 3S-64E-12ca has been pumped...Valley is probably over 10,000 feet (3048 m) thick in the central part of the valley and is composed of alluvial fan, fluvial, playa , srl lacustrine...VALLEY T3.NSmIP STATION T E𔃾P SP. or SS. SILICA C AL C IU4 ACG. E5SILJ4 SCDIU I QANSA-SECT 5 6 C1 Ŕ VQ %;,. DES C CONE PH SOLIDS (5102) CA V$ A% 1 IN/6

  6. Fretted Terrain Valleys

    NASA Technical Reports Server (NTRS)

    2004-01-01

    30 October 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows shallow tributary valleys in the Ismenius Lacus fretted terrain region of northern Arabia Terra. These valleys exhibit a variety of typical fretted terrain valley wall and floor textures, including a lineated, pitted material somewhat reminiscent of the surface of a brain. Origins for these features are still being debated within the Mars science community; there are no clear analogs to these landforms on Earth. This image is located near 39.9oN, 332.1oW. The picture covers an area about 3 km (1.9 mi) wide. Sunlight illuminates the scene from the lower left.

  7. Dispersal, movements and site fidelity of post-fledging King Eiders Somateria spectabilis and their attendant females

    USGS Publications Warehouse

    Bentzen, Rebecca L.; Powell, Abby N.

    2015-01-01

    Post-fledging dispersal and site fidelity are poorly understood, particularly for sea ducks that spend the majority of their annual cycle at sea. This is the first description of movements and their timing for first-year (juvenile) and second-year (subadult) King Eiders Somateria spectabilis in relation to their attendant females. We fitted satellite transmitters that operated for 2 years to 63 hatch-year birds and 17 attendant females at breeding areas in northern Alaska in 2006–2009. Our goals were to describe the spatio-temporal distribution of pre-breeding individuals and adult females that had been successful breeders. We also examined fidelity to wing moulting and wintering areas as well as natal philopatry. Juveniles did not appear to follow attendant adults, although they did winter in the same three general wintering areas, suggesting that genetic inheritance and social factors may have roles in the initial migration from the breeding area. Additionally, juveniles were more variable in the timing and duration of migration, moved longer distances during the winter, and were less faithful to moulting and wintering areas than adults, indicating that individual exploration and acquired navigational memory played a role in subsequent migrations. Most (75%) subadult females returned to natal areas, probably prospecting for future nesting sites, whereas subadult males were widely dispersed at sea. Timing and duration of moult migration and wing moult of adult females that were presumed to be successful breeders differed from those of unsuccessful breeders due to the extended time that the former spent on the breeding grounds. Temporal and spatial segregation of post-fledging King Eiders from adults has direct management implications in terms of resource development and population dynamics.

  8. Overview of Reclamation's geothermal program in Imperial Valley, California

    NASA Technical Reports Server (NTRS)

    Fulcher, M. K.

    1974-01-01

    The Bureau of Reclamation is presently involved in a unique Geothermal Resource Development Program in Imperial Valley, California. The main purpose of the investigations is to determine the feasibility of providing a source of fresh water through desalting geothermal fluids stored in the aquifers underlying the valley. Significant progress in this research and development stage to date includes extensive geophysical investigations and the drilling of five geothermal wells on the Mesa anomaly. Four of the wells are for production and monitoring the anomaly, and one will be used for reinjection of waste brines from the desalting units. Two desalting units, a multistage flash unit and a vertical tube evaporator unit, have been erected at the East Mesa test site. The units have been operated on shakedown and continuous runs and have produced substantial quantities of high-quality water.

  9. Testing of the Prototype Mars Drill and Sample Acquisition System in the Mars Analog Site of the Antarctica's Dry Valleys

    NASA Astrophysics Data System (ADS)

    Zacny, K.; Paulsen, G.; McKay, C.; Glass, B. J.; Marinova, M.; Davila, A. F.; Pollard, W. H.; Jackson, A.

    2011-12-01

    We report on the testing of the one meter class prototype Mars drill and cuttings sampling system, called the IceBreaker in the Dry Valleys of Antarctica. The drill consists of a rotary-percussive drill head, a sampling auger with a bit at the end having an integrated temperature sensor, a Z-stage for advancing the auger into the ground, and a sampling station for moving the augered ice shavings or soil cuttings into a sample cup. In November/December of 2010, the IceBreaker drill was tested in the Uni-versity Valley (within the Beacon Valley region of the Antarctic Dry Valleys). University Valley is a good analog to the Northern Polar Regions of Mars because a layer of dry soil lies on top of either ice-cemeted ground or massive ice (depending on the location within the valley). That is exactly what the 2007 Phoenix mission discovered on Mars. The drill demonstrated drilling in ice-cemented ground and in massive ice at the 1-1-100-100 level; that is the drill reached 1 meter in 1 hour with 100 Watts of power and 100 Newton Weight on Bit. This corresponds to an average energy of 100 Whr. At the same time, the bit temperature measured by the bit thermocouple did not exceed more than 10 °C above the formation temperature. The temperature also never exceeded freezing, which minimizes chances of getting stuck and also of altering the materials that are being sampled and analyzed. The samples in the forms of cuttings were acquired every 10 cm intervals into sterile bags. These tests have shown that drilling on Mars, in ice cemented ground with limited power, energy and Weight on Bit, and collecting samples in discrete depth intervals is possible within the given mass, power, and energy levels of a Phoenix-size lander and within the duration of a Phoenix-like mission.

  10. Atmospheric transport of organophosphate pesticides from California's Central Valley to the Sierra Nevada Mountains

    USGS Publications Warehouse

    Zabik, John M.; Seiber, James N.

    1993-01-01

    Atmospheric transport of organophosphate pesticides from California's Central Valley to the Sierra Nevada mountains was assessed by collecting air- and wet-deposition samples during December, January, February, and March, 1990 to 1991. Large-scale spraying of these pesticides occurs during December and January to control insect infestations in valley orchards. Sampling sites were placed at 114- (base of the foothills), 533-, and 1920-m elevations. Samples acquired at these sites contained chlorpyrifos [phosphorothioic acid; 0,0-diethyl 0-(3,5,6-trichloro-2-pyridinyl) ester], parathion [phosphorothioic acid, 0-0-diethylo-(4-nitrophenyl) ester], diazinon {phosphorothioic acid, 0,0-diethyl 0-[6-methyl-2-(1-methylethyl)-4-pyrimidinyl] ester} diazinonoxon {phosphoric acid, 0,0-diethyl 0-[6-methyl-2-(1-methylethyl)-4-pyrimidinyl] ester}, and paraoxon [phosphoric acid, 0,0-diethyl 0-(4-nitrophenyl) ester] in both air and wet deposition samples. Air concentrations of chloropyrifos, diazinon and parathion ranged from 13 to 13 000 pg/m3 at the base of the foothills. At 533-m air concentrations were below the limit of quantification (1.4 pg/m3) to 83 pg/m3 and at 1920 m concentrations were below the limit of quantification. Concentrations in wet deposition varied with distance and elevation from the Central Valley. Rainwater concentrations at the base of the foot hills ranged from 16 to 7600 pg/mL. At 533-m rain and snow water concentrations ranged from below the limit of quantification (1.3 pg/mL) to 140 pg/mL and at 1920 m concentrations ranged from below the limit of quantification to 48 pg/mL. These findings indicate that atmospheric transport of pesticides applied in the valley to the Sierra Nevada mountains is occurring, but the levels decrease as distance and elevation increase from the valley floor.

  11. Observations of Air Quality at the Edge of Kathmandu, Nepal, and the Diurnal Cycle of Air Pollution In and Around the Kathmandu Valley

    NASA Astrophysics Data System (ADS)

    Panday, A. K.; Prinn, R. G.; Regmi, R. P.

    2006-12-01

    The Kathmandu Valley is a bowl-shaped basin in the Nepal Himalaya, with a rapidly growing city surrounded by rice fields and steep terraced and forested mountain slopes. The valley's air quality is influenced by urban and rural emissions, nocturnal pooling of cold air, slope winds, and a daily exchange of air through mountain passes. To understand these processes and to inform air pollution policy in Nepal, we have carried out the most comprehensive study of air pollution in Nepal to date. During the 9-month dry season of 2004-2005, we carried out continuous measurements every minute of carbon monoxide, ozone, PM10, wind speed, wind direction, solar radiation, temperature, and humidity on the eastern edge of Kathmandu city, at a site that daily received air from both the city and rural areas. We recorded the diurnal cycle of the vertical temperature structure and stability with temperature loggers on towers and mountains. A sodar measured the mixed layer height and upper-level winds. 24-hour simultaneous bag sampling campaigns on mountain peaks, passes, the rural valley, and within the city provided glimpses of the spatial patterns of the diurnal cycle of CO -- a useful tracer of anthropogenic emissions. We measured winds on mountain passes and ozone on mountain peaks. At our main measurement site we found a daily-recurring pattern of CO and PM10, with an afternoon low showing rural background levels, even though the arriving air had traversed the city. This was followed by an evening peak starting at sunset, a second low late at night, and a morning peak enhanced by re-circulation. Pollutants emitted in the valley only traveled out of the valley between the late morning and sunset. During winter months, rush hour was outside of this period, enhancing the morning and evening peaks. Within the city, ozone dropped to zero at night. At mid-day we observed an ozone peak enhanced by photochemical production when the air mass that had been stagnant over the city swept

  12. Induced dynamic nonlinear ground response at Gamer Valley, California

    USGS Publications Warehouse

    Lawrence, Z.; Bodin, P.; Langston, C.A.; Pearce, F.; Gomberg, J.; Johnson, P.A.; Menq, F.-Y.; Brackman, T.

    2008-01-01

    We present results from a prototype experiment in which we actively induce, observe, and quantify in situ nonlinear sediment response in the near surface. This experiment was part of a suite of experiments conducted during August 2004 in Garner Valley, California, using a large mobile shaker truck from the Network for Earthquake Engineering Simulation (NEES) facility. We deployed a dense accelerometer array within meters of the mobile shaker truck to replicate a controlled, laboratory-style soil dynamics experiment in order to observe wave-amplitude-dependent sediment properties. Ground motion exceeding 1g acceleration was produced near the shaker truck. The wave field was dominated by Rayleigh surface waves and ground motions were strong enough to produce observable nonlinear changes in wave velocity. We found that as the force load of the shaker increased, the Rayleigh-wave phase velocity decreased by as much as ???30% at the highest frequencies used (up to 30 Hz). Phase velocity dispersion curves were inverted for S-wave velocity as a function of depth using a simple isotropic elastic model to estimate the depth dependence of changes to the velocity structure. The greatest change in velocity occurred nearest the surface, within the upper 4 m. These estimated S-wave velocity values were used with estimates of surface strain to compare with laboratory-based shear modulus reduction measurements from the same site. Our results suggest that it may be possible to characterize nonlinear soil properties in situ using a noninvasive field technique.

  13. Geologic history of the Yosemite Valley

    USGS Publications Warehouse

    Matthes, Francois E.

    1930-01-01

    Projection of the longitudinal profiles of these hanging valleys forward to the axis of the Merced Canyon shows that they are closely accordant in height. Their profiles indicate a series of points on a former profile of the Merced with respect to which the side streams had graded their courses prior to the last uplift. This old profile can be extended upward into the glaciated part of the Merced Canyon above El Portal and even into the profoundly glaciated Yosemite Valley, accordant points being furnished by a number of hanging side valleys (due allowance being made for glacial erosion suffered by those valleys). However, not all the hanging valleys of the Yosemite region are accordant with this set. Several of them, including the upland valley of Yosemite Creek, constitute a separate set indicating another old profile of the Merced at a level 600 to 1,000 feet higher than the first. Others, including the hanging gulch of lower Bridalveil Creek, point to an old profile of the Merced about 1,200 feet lower than the first. There are thus three distinct sets of hanging valleys produced in three cycles of stream erosion. The valleys of the upper set, like those of the middle set, were left hanging as a result of rapid trenching by the Merced induced by an uplift of the range, there having been two such uplifts. Only the valleys of the lower set hang because of glacial deepening and widening of the Yosemite Valley, the cycle in which they were cut having been interrupted by the advent of the Pleistocene glaciers. They consequently indicate the preglacial depth of the Yosemite Valley. That depth, measured from the brow of El Capitan, was about 2,400 feet; measured from the rim at Glacier Point it was about 2,000 feet.

  14. AIR DISPERSION MODELING AT THE WASTE ISOLATION PILOT PLANT

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rucker, D.F.

    2000-08-01

    One concern at the Waste Isolation Pilot Plant (WIPP) is the amount of alpha-emitting radionuclides or hazardous chemicals that can become airborne at the facility and reach the Exclusive Use Area boundary as the result of a release from the Waste Handling Building (WHB) or from the underground during waste emplacement operations. The WIPP Safety Analysis Report (SAR), WIPP RCRA Permit, and WIPP Emergency Preparedness Hazards Assessments include air dispersion calculations to address this issue. Meteorological conditions at the WIPP facility will dictate direction, speed, and dilution of a contaminant plume of respirable material due to chronic releases or duringmore » an accident. Due to the paucity of meteorological information at the WIPP site prior to September 1996, the Department of Energy (DOE) reports had to rely largely on unqualified climatic data from the site and neighboring Carlsbad, which is situated approximately 40 km (26 miles) to the west of the site. This report examines the validity of the DOE air dispersion calculations using new meteorological data measured and collected at the WIPP site since September 1996. The air dispersion calculations in this report include both chronic and acute releases. Chronic release calculations were conducted with the EPA-approved code, CAP88PC and the calculations showed that in order for a violation of 40 CFR61 (NESHAPS) to occur, approximately 15 mCi/yr of 239Pu would have to be released from the exhaust stack or from the WHB. This is an extremely high value. Hence, it is unlikely that NESHAPS would be violated. A site-specific air dispersion coefficient was evaluated for comparison with that used in acute dose calculations. The calculations presented in Section 3.2 and 3.3 show that one could expect a slightly less dispersive plume (larger air dispersion coefficient) given greater confidence in the meteorological data, i.e. 95% worst case meteorological conditions. Calculations show that dispersion will

  15. Mars: Periglacial Morphology and Implications for Future Landing Sites

    NASA Technical Reports Server (NTRS)

    Heldmann, Jennifer L.; Schurmeier, Lauren; McKay, Christopher; Davila, Alfonso; Stoker, Carol; Marinova, Margarita; Wilhelm, Mary Beth

    2015-01-01

    At the Mars Phoenix landing site and in much of the Martian northern plains, there is ice-cemented ground beneath a layer of dry permafrost. Unlike most permafrost on Earth, though, this ice is not liquid at any time of year. However, in past epochs at higher obliquity the surface conditions during summer may have resulted in warmer conditions and possible melting. This situation indicates that the ice-cemented ground in the north polar plains is likely to be a candidate for the most recently habitable place on Mars as near-surface ice likely provided adequate water activity approximately 5 Myr ago. The high elevation Dry Valleys of Antarctica provide the best analog on Earth of Martian ground ice. These locations are the only places on Earth where ice-cemented ground is found beneath dry permafrost. The Dry Valleys are a hyper-arid polar desert environment and in locations above 1500 m elevation, such as University Valley, air temperatures do not exceed 0 C. Thus, similarly to Mars, liquid water is largely absent here and instead the hydrologic cycle is dominated by frozen ice and vapor phase processes such as sublimation. These conditions make the high elevation Dry Valleys a key Mars analog location where periglacial processes and geomorphic features can be studied in situ. This talk will focus on studies of University Valley as a Mars analog for periglacial morphology and ice stability. We will review a landing site selection study encompassing this information gleaned from the Antarctic terrestrial analog studies plus Mars spacecraft data analysis to identify candidate landing sites for a future mission to search for life on Mars.

  16. Post-Fledging Dispersal of King Penguins (Aptenodytes patagonicus) from Two Breeding Sites in the South Atlantic

    PubMed Central

    Pütz, Klemens; Trathan, Phil N.; Pedrana, Julieta; Collins, Martin A.; Poncet, Sally; Lüthi, Benno

    2014-01-01

    Most studies concerning the foraging ecology of marine vertebrates are limited to breeding adults, although other life history stages might comprise half the total population. For penguins, little is known about juvenile dispersal, a period when individuals may be susceptible to increased mortality given their naïve foraging behaviour. Therefore, we used satellite telemetry to study king penguin fledglings (n = 18) from two sites in the Southwest Atlantic in December 2007. The two sites differed with respect to climate and proximity to the Antarctic Polar Front (APF), a key oceanographic feature generally thought to be important for king penguin foraging success. Accordingly, birds from both sites foraged predominantly in the vicinity of the APF. Eight king penguins were tracked for periods greater than 120 days; seven of these (three from the Falkland Islands and four from South Georgia) migrated into the Pacific. Only one bird from the Falkland Islands moved into the Indian Ocean, visiting the northern limit of the winter pack-ice. Three others from the Falkland Islands migrated to the eastern coast of Tierra del Fuego before travelling south. Derived tracking parameters describing their migratory behaviour showed no significant differences between sites. Nevertheless, generalized linear habitat modelling revealed that juveniles from the Falkland Islands spent more time in comparatively shallow waters with low sea surface temperature, sea surface height and chlorophyll variability. Birds from South Georgia spent more time in deeper waters with low sea surface temperature and sea surface height, but high concentrations of chlorophyll. Our results indicate that inexperienced king penguins, irrespective of the location of their natal site in relation to the position of the APF, develop their foraging skills progressively over time, including specific adaptations to the environment around their prospective breeding site. PMID:24828545

  17. Post-fledging dispersal of king penguins (Aptenodytes patagonicus) from two breeding sites in the South Atlantic.

    PubMed

    Pütz, Klemens; Trathan, Phil N; Pedrana, Julieta; Collins, Martin A; Poncet, Sally; Lüthi, Benno

    2014-01-01

    Most studies concerning the foraging ecology of marine vertebrates are limited to breeding adults, although other life history stages might comprise half the total population. For penguins, little is known about juvenile dispersal, a period when individuals may be susceptible to increased mortality given their naïve foraging behaviour. Therefore, we used satellite telemetry to study king penguin fledglings (n = 18) from two sites in the Southwest Atlantic in December 2007. The two sites differed with respect to climate and proximity to the Antarctic Polar Front (APF), a key oceanographic feature generally thought to be important for king penguin foraging success. Accordingly, birds from both sites foraged predominantly in the vicinity of the APF. Eight king penguins were tracked for periods greater than 120 days; seven of these (three from the Falkland Islands and four from South Georgia) migrated into the Pacific. Only one bird from the Falkland Islands moved into the Indian Ocean, visiting the northern limit of the winter pack-ice. Three others from the Falkland Islands migrated to the eastern coast of Tierra del Fuego before travelling south. Derived tracking parameters describing their migratory behaviour showed no significant differences between sites. Nevertheless, generalized linear habitat modelling revealed that juveniles from the Falkland Islands spent more time in comparatively shallow waters with low sea surface temperature, sea surface height and chlorophyll variability. Birds from South Georgia spent more time in deeper waters with low sea surface temperature and sea surface height, but high concentrations of chlorophyll. Our results indicate that inexperienced king penguins, irrespective of the location of their natal site in relation to the position of the APF, develop their foraging skills progressively over time, including specific adaptations to the environment around their prospective breeding site.

  18. 76 FR 22746 - Conecuh Valley Railway, LLC-Acquisition and Operation Exemption-Conecuh Valley Railroad Co., Inc.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-22

    ... Railway, LLC--Acquisition and Operation Exemption--Conecuh Valley Railroad Co., Inc. Conecuh Valley Railway, LLC (CVR), a noncarrier, has filed a verified notice of exemption under 49 CFR 1150.31 to acquire from Conecuh Valley Railroad Co., Inc. (COEH), and to operate [[Page 22747

  19. The conservation physiology of seed dispersal

    PubMed Central

    Ruxton, Graeme D.; Schaefer, H. Martin

    2012-01-01

    At a time when plant species are experiencing increasing challenges from climate change, land-use change, harvesting and invasive species, dispersal has become a very important aspect of plant conservation. Seed dispersal by animals is particularly important because some animals disperse seeds to suitable sites in a directed fashion. Our review has two aims: (i) to highlight the various ways plant dispersal by animals can be affected by current anthropogenic change and (ii) to show the important role of plant and (particularly) animal physiology in shaping seed–dispersal interactions. We argue that large-bodied seed dispersers may be particularly important for plant conservation because seed dispersal of large-seeded plants is often more specialized and because large-bodied animals are targeted by human exploitation and have smaller population sizes. We further argue that more specialized seed-dispersal systems on island ecosystems might be particularly at risk from climate change both owing to small population sizes involved but also owing to the likely thermal specialization, particularly on tropical islands. More generally, the inherent vulnerability of seed-dispersal mutualisms to disruption driven by environmental change (as well as their ubiquity) demands that we continue to improve our understanding of their conservation physiology. PMID:22566677

  20. Death Valley, California

    NASA Image and Video Library

    1994-04-11

    . Death Valley is also one of the primary calibration sites for SIR-C/X-SAR. The bright dots near the center of the image are corner reflectors that have been set-up to calibrate the radar as the Shuttle passes overhead. Thirty triangular-shaped reflectors (they look like aluminum pyramids) have been deployed by the calibration team from JPL over a 40 kilometer by 40 kilometer area in and around Death Valley. The calibration team will also deploy transponders (electronic reflectors) and recievers to measure the radar signals from SIR-C/X-SAR on the ground. Spaceborne Imaging Radar-C and X-Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth (MTPE). The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-Band (24 cm), C-Band (6 cm), and X-Band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was develpoed by NASA's Jet Propulsion Laboratory (JPL). X-SAR was developed by the Dornire and Alenia Spazio Companies for the German Space Agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian Space Agency, Agenzia Spaziale Italiana (ASI). JPL Photo ID: P-43883

  1. Female dispersal, social organization, and infanticide in langurs: are they linked to human disturbance?

    PubMed

    Sterck, E H

    1998-01-01

    Female dispersal in gregarious animals can involve the desertion of a site, desertion of a social group, or both. Group desertion may be related to inbreeding avoidance. Group fidelity may result from cooperation among females in a group. Site fidelity will be more likely when food can be monopolized and when the population density is close to habitat saturation. The degree of habitat saturation was approximated with a measure of human disturbance. The influence of these various factors on the incidence of female dispersal was investigated for langur populations using data from the literature. The results suggest that female dispersal in langurs involved site desertion, not group desertion. The incidence of female dispersal may affect the social organization of langurs. I propose that when females do not disperse, male takeovers prevail, whereas in populations where female dispersal regularly occurs bisexual groups are disbanded or new groups are formed, a process I call female split-merger. Male takeover is thought to occur when site fidelity is high, female split-merger when site fidelity is low. These processes were indeed found to occur in these circumstances. The dispersal of females might prevent infanticide, whereas male takeover might promote it. Indeed, in studies with male takeover, more infants fell victim to infanticide than in studies with female split-merger. Therefore, female dispersal in langurs is an effective female counterstrategy to infanticide. The factor that had the most profound effect on female dispersal, social organization, and infanticide was habitat saturation. Habitat saturation was measured as the degree of human disturbance, and its influence on the behavior of langurs is probably of relatively recent date. This may lead to an evolutionary transient situation and may explain the discrepancy between current socioecological theories and the behavior of langurs in populations lacking female dispersal.

  2. Simulation And Forecasting of Daily Pm10 Concentrations Using Autoregressive Models In Kagithane Creek Valley, Istanbul

    NASA Astrophysics Data System (ADS)

    Ağaç, Kübra; Koçak, Kasım; Deniz, Ali

    2015-04-01

    A time series approach using autoregressive model (AR), moving average model (MA) and seasonal autoregressive integrated moving average model (SARIMA) were used in this study to simulate and forecast daily PM10 concentrations in Kagithane Creek Valley, Istanbul. Hourly PM10 concentrations have been measured in Kagithane Creek Valley between 2010 and 2014 periods. Bosphorus divides the city in two parts as European and Asian parts. The historical part of the city takes place in Golden Horn. Our study area Kagithane Creek Valley is connected with this historical part. The study area is highly polluted because of its topographical structure and industrial activities. Also population density is extremely high in this site. The dispersion conditions are highly poor in this creek valley so it is necessary to calculate PM10 levels for air quality and human health. For given period there were some missing PM10 concentration values so to make an accurate calculations and to obtain exact results gap filling method was applied by Singular Spectrum Analysis (SSA). SSA is a new and efficient method for gap filling and it is an state-of-art modeling. SSA-MTM Toolkit was used for our study. SSA is considered as a noise reduction algorithm because it decomposes an original time series to trend (if exists), oscillatory and noise components by way of a singular value decomposition. The basic SSA algorithm has stages of decomposition and reconstruction. For given period daily and monthly PM10 concentrations were calculated and episodic periods are determined. Long term and short term PM10 concentrations were analyzed according to European Union (EU) standards. For simulation and forecasting of high level PM10 concentrations, meteorological data (wind speed, pressure and temperature) were used to see the relationship between daily PM10 concentrations. Fast Fourier Transformation (FFT) was also applied to the data to see the periodicity and according to these periods models were built

  3. Energy Balance, Evapo-transpiration and Dew deposition in the Dead Sea Valley

    NASA Astrophysics Data System (ADS)

    Metzger, Jutta; Corsmeier, Ulrich

    2016-04-01

    The Dead Sea is a unique place on earth. It is a terminal hypersaline lake, located at the lowest point on earth with a lake level of currently -429 m above mean sea level (amsl). It is located in a transition zone of semiarid to arid climate conditions, which makes it highly sensible to climate change (Alpert1997, Smiatek2011). The Virtual Institute DEad SEa Research Venue (DESERVE) is an international project funded by the German Helmholtz Association and was established to study coupled atmospheric hydrological, and lithospheric processes in the changing environment of the Dead Sea. At the moment the most prominent environmental change is the lake level decline of approximately 1 m / year due to anthropogenic interferences (Gertman, 2002). This leads to noticeable changes in the fractions of the existing terrestrial surfaces - water, bare soil and vegetated areas - in the valley. Thus, the partitioning of the net radiation in the valley changes as well. To thoroughly study the atmospheric and hydrological processes in the Dead Sea valley, which are driven by the energy balance components, sound data of the energy fluxes of the different surfaces are necessary. Before DESERVE no long-term monitoring network simultaneously measuring the energy balance components of the different surfaces in the Dead Sea valley was available. Therefore, three energy balance stations were installed at three characteristic sites at the coast-line, over bare soil, and within vegetation, measuring all energy balance components by using the eddy covariance method. The results show, that the partitioning of the energy into sensible and latent heat flux on a diurnal scale is totally different at the three sites. This results in gradients between the sites, which are e.g. responsible for the typical diurnal wind systems at the Dead Sea. Furthermore, driving forces of evapo-transpiration at the sites were identified and a detailed analysis of the daily evaporation and dew deposition rates

  4. Ground-water quality and geochemistry of Las Vegas Valley, Clark County, Nevada, 1981-83; implementation of a monitoring network

    USGS Publications Warehouse

    Dettinger, M.D.

    1987-01-01

    As a result of rapid urban growth in Las Vegas Valley, rates of water use and wastewater disposal have grown rapidly during the last 25 years. Concern has developed over the potential water quality effects of this growth. The deep percolation of wastewater and irrigation return flow (much of which originates as imported water from Lake Mead), along with severe overdraft conditions in the principal aquifers of the valley, could combine to pose a long-term threat to groundwater quality. The quantitative investigations of groundwater quality and geochemical conditions in the valley necessary to address these concerns would include the establishment of data collection networks on a valley-wide scale that differ substantially from existing networks. The valley-wide networks would have a uniform areal distribution of sampling sites, would sample from all major depth zones, and would entail repeated sampling from each site. With these criteria in mind, 40 wells were chosen for inclusion in a demonstration monitoring network. Groundwater in the northern half of the valley generally contains 200 to 400 mg/L of dissolved solids, and is dominated by calcium, magnesium , and bicarbonate ions, reflecting a chemical equilibrium between the groundwater and the dominantly carbonate rocks in the aquifers of this area. The intermediate to deep groundwater in the southern half of the valley is of poorer quality (containing 700 to 1,500 mg/L of dissolved solids) and is dominated by calcium, magnesium, sulfate, and bicarbonate ions, reflecting the occurrence of other rock types including evaporite minerals among the still-dominant carbonate rocks in the aquifers of this part of the valley. The poorest quality groundwater in the valley is generally in the lowland parts of the valley in the first few feet beneath the water table, where dissolved solids concentrations range from 2,000 to > 7,000 mg/L , and probably reflects the effects of evaporite dissolution, secondary recharge, and

  5. Larval fish dispersal in a coral-reef seascape.

    PubMed

    Almany, Glenn R; Planes, Serge; Thorrold, Simon R; Berumen, Michael L; Bode, Michael; Saenz-Agudelo, Pablo; Bonin, Mary C; Frisch, Ashley J; Harrison, Hugo B; Messmer, Vanessa; Nanninga, Gerrit B; Priest, Mark A; Srinivasan, Maya; Sinclair-Taylor, Tane; Williamson, David H; Jones, Geoffrey P

    2017-05-08

    Larval dispersal is a critical yet enigmatic process in the persistence and productivity of marine metapopulations. Empirical data on larval dispersal remain scarce, hindering the use of spatial management tools in efforts to sustain ocean biodiversity and fisheries. Here we document dispersal among subpopulations of clownfish (Amphiprion percula) and butterflyfish (Chaetodon vagabundus) from eight sites across a large seascape (10,000 km 2 ) in Papua New Guinea across 2 years. Dispersal of clownfish was consistent between years, with mean observed dispersal distances of 15 km and 10 km in 2009 and 2011, respectively. A Laplacian statistical distribution (the dispersal kernel) predicted a mean dispersal distance of 13-19 km, with 90% of settlement occurring within 31-43 km. Mean dispersal distances were considerably greater (43-64 km) for butterflyfish, with kernels declining only gradually from spawning locations. We demonstrate that dispersal can be measured on spatial scales sufficient to inform the design of and test the performance of marine reserve networks.

  6. Topological Valley Currents in Gapped Dirac Materials

    NASA Astrophysics Data System (ADS)

    Lensky, Yuri D.; Song, Justin C. W.; Samutpraphoot, Polnop; Levitov, Leonid S.

    2015-06-01

    Gapped 2D Dirac materials, in which inversion symmetry is broken by a gap-opening perturbation, feature a unique valley transport regime. Topological valley currents in such materials are dominated by bulk currents produced by electronic states just beneath the gap rather than by edge modes. The system ground state hosts dissipationless persistent valley currents existing even when topologically protected edge modes are absent. Valley currents induced by an external bias are characterized by a quantized half-integer valley Hall conductivity. The undergap currents dominate magnetization and the charge Hall effect in a light-induced valley-polarized state.

  7. Field Surveys, IOC Valleys. Volume III, Part II. Cultural Resources Survey, Pine and Wah Wah Valleys, Utah.

    DTIC Science & Technology

    1981-08-01

    valleys are typical of the Basin and Range Province, characterized by parallel, north-south trending mountain ranges, separated by hydrologically closed... basins . Pine and Wah Wah valleys each have hardpan-playas in their lowest areas. State Highway 21 runs roughly northwest-southeast through both val...have been important for prehis- toric and historic use of the area. Pine Valley: Pine and Wah Wah valleys are closed alluvial basins . The central part

  8. Characterization of a 21-Story Reinforced Building in the Valley of Mexico Using MEMS Accelerometers.

    NASA Astrophysics Data System (ADS)

    Husker, A. L.; Dominguez, L. A.; Becerril, A.; Espejo, L.; Cochran, E. S.

    2014-12-01

    Low cost MEMS accelerometers are becoming increasingly higher resolution making them useful in strong motion studies. Here we present a building response analysis in the lakebed zone of the Valley of Mexico. The Valley of Mexico represents one of the highest seismic risk locations in the world and incorporates Mexico City and part of Mexico State. More than 20 million people live there and it is the political and economic center of Mexico. In addition the valley has very high site effects with amplifications 100 - 500 times that of sites outside of the basin (Singh et al., 1988; Singh et al., 1995). We instrumented a 21-story building with MEMS accelerometers as part of the Quake Catcher Network or Red Atrapa Sismos as it is called in Mexico. The building known as the Centro Cultural de Tlateloco is located in an important historical and political area as well as a zone with some of the highest amplifications in the Valley of Mexico that had some of the worst destruction after the 1985 M8.1 Michoacan earthquake. During the earthquake most of the buildings that failed were between 7 - 18 stories tall. The peak accelerations near Tlateloco were at periods of 2 seconds. Since the earthquake the building has been retrofitted with N-S crossing supports to help withstand another earthquake. We present the measurements of frequencies and amplifications between floors for the length of the building.

  9. Site response, shallow shear-wave velocity, and wave propagation at the San Jose, California, dense seismic array

    USGS Publications Warehouse

    Hartzell, S.; Carver, D.; Williams, R.A.; Harmsen, S.; Zerva, A.

    2003-01-01

    Ground-motion records from a 52-element dense seismic array near San Jose, California, are analyzed to obtain site response, shallow shear-wave velocity, and plane-wave propagation characteristics. The array, located on the eastern side of the Santa Clara Valley south of the San Francisco Bay, is sited over the Evergreen basin, a 7-km-deep depression with Miocene and younger deposits. Site response values below 4 Hz are up to a factor of 2 greater when larger, regional records are included in the analysis, due to strong surface-wave development within the Santa Clara Valley. The pattern of site amplification is the same, however, with local or regional events. Site amplification increases away from the eastern edge of the Santa Clara Valley, reaching a maximum over the western edge of the Evergreen basin, where the pre-Cenozoic basement shallows rapidly. Amplification then decreases further to the west. This pattern may be caused by lower shallow shear-wave velocities and thicker Quaternary deposits further from the edge of the Santa Clara Valley and generation/trapping of surface waves above the shallowing basement of the western Evergreen basin. Shear-wave velocities from the inversion of site response spectra based on smaller, local earthquakes compare well with those obtained independently from our seismic reflection/refraction measurements. Velocities from the inversion of site spectra that include larger, regional records do not compare well with these measurements. A mix of local and regional events, however, is appropriate for determination of site response to be used in seismic hazard evaluation, since large damaging events would excite both body and surface waves with a wide range in ray parameters. Frequency-wavenumber, plane-wave analysis is used to determine the backazimuth and apparent velocity of coherent phases at the array. Conventional, high-resolution, and multiple signal characterization f-k power spectra and stacked slowness power spectra are

  10. Long Duration of Ground Motion in the Paradigmatic Valley of Mexico

    PubMed Central

    Cruz-Atienza, V. M.; Tago, J.; Sanabria-Gómez, J. D.; Chaljub, E.; Etienne, V.; Virieux, J.; Quintanar, L.

    2016-01-01

    Built-up on top of ancient lake deposits, Mexico City experiences some of the largest seismic site effects worldwide. Besides the extreme amplification of seismic waves, duration of intense ground motion from large subduction earthquakes exceeds three minutes in the lake-bed zone of the basin, where hundreds of buildings collapsed or were seriously damaged during the magnitude 8.0 Michoacán earthquake in 1985. Different mechanisms contribute to the long lasting motions, such as the regional dispersion and multiple-scattering of the incoming wavefield from the coast, more than 300 km away the city. By means of high performance computational modeling we show that, despite the highly dissipative basin deposits, seismic energy can propagate long distances in the deep structure of the valley, promoting also a large elongation of motion. Our simulations reveal that the seismic response of the basin is dominated by surface-waves overtones, and that this mechanism increases the duration of ground motion by more than 170% and 290% of the incoming wavefield duration at 0.5 and 0.3 Hz, respectively, which are two frequencies with the largest observed amplification. This conclusion contradicts what has been previously stated from observational and modeling investigations, where the basin itself has been discarded as a preponderant factor promoting long and devastating shaking in Mexico City. PMID:27934934

  11. Long Duration of Ground Motion in the Paradigmatic Valley of Mexico

    NASA Astrophysics Data System (ADS)

    Cruz-Atienza, V. M.; Tago, J.; Sanabria-Gómez, J. D.; Chaljub, E.; Etienne, V.; Virieux, J.; Quintanar, L.

    2016-12-01

    Built-up on top of ancient lake deposits, Mexico City experiences some of the largest seismic site effects worldwide. Besides the extreme amplification of seismic waves, duration of intense ground motion from large subduction earthquakes exceeds three minutes in the lake-bed zone of the basin, where hundreds of buildings collapsed or were seriously damaged during the magnitude 8.0 Michoacán earthquake in 1985. Different mechanisms contribute to the long lasting motions, such as the regional dispersion and multiple-scattering of the incoming wavefield from the coast, more than 300 km away the city. By means of high performance computational modeling we show that, despite the highly dissipative basin deposits, seismic energy can propagate long distances in the deep structure of the valley, promoting also a large elongation of motion. Our simulations reveal that the seismic response of the basin is dominated by surface-waves overtones, and that this mechanism increases the duration of ground motion by more than 170% and 290% of the incoming wavefield duration at 0.5 and 0.3 Hz, respectively, which are two frequencies with the largest observed amplification. This conclusion contradicts what has been previously stated from observational and modeling investigations, where the basin itself has been discarded as a preponderant factor promoting long and devastating shaking in Mexico City.

  12. Long Duration of Ground Motion in the Paradigmatic Valley of Mexico.

    PubMed

    Cruz-Atienza, V M; Tago, J; Sanabria-Gómez, J D; Chaljub, E; Etienne, V; Virieux, J; Quintanar, L

    2016-12-09

    Built-up on top of ancient lake deposits, Mexico City experiences some of the largest seismic site effects worldwide. Besides the extreme amplification of seismic waves, duration of intense ground motion from large subduction earthquakes exceeds three minutes in the lake-bed zone of the basin, where hundreds of buildings collapsed or were seriously damaged during the magnitude 8.0 Michoacán earthquake in 1985. Different mechanisms contribute to the long lasting motions, such as the regional dispersion and multiple-scattering of the incoming wavefield from the coast, more than 300 km away the city. By means of high performance computational modeling we show that, despite the highly dissipative basin deposits, seismic energy can propagate long distances in the deep structure of the valley, promoting also a large elongation of motion. Our simulations reveal that the seismic response of the basin is dominated by surface-waves overtones, and that this mechanism increases the duration of ground motion by more than 170% and 290% of the incoming wavefield duration at 0.5 and 0.3 Hz, respectively, which are two frequencies with the largest observed amplification. This conclusion contradicts what has been previously stated from observational and modeling investigations, where the basin itself has been discarded as a preponderant factor promoting long and devastating shaking in Mexico City.

  13. Dispersal and survival of a polygynandrous passerine

    USGS Publications Warehouse

    Craig, Heather R.; Kendall, Steve J.; Wild, Teri C.; Powell, Abby N.

    2015-01-01

    Although sex biases in survival and dispersal are thought to be linked to avian mating systems, little is known about these demographic patterns in less common mating strategies such as polygynandry. We investigated breeding-site fidelity, natal philopatry, and apparent survival of the polygynandrous Smith's Longspur (Calcarius pictus) over a 7-yr period at 2 areas in Alaska's Brooks Range. We used capture–recapture histories of 243 color-banded adults and 431 juveniles to estimate annual survival and determined dispersal patterns from 34 adults that were found breeding within the study areas over multiple years. Most adults (88%) returned to nest in the same breeding neighborhood as in previous years; mean dispersal distance was 300.9 ± 74.2 m and did not differ between sexes. Juveniles exhibited low natal philopatry; only 4% of banded hatch-year birds were resighted as adults during subsequent years. Those that did return dispersed, on average, 1,674.4 ± 465.8 m from their natal nests (n = 6). Model-averaged survival estimates indicated that annual survival of adult females (50–58%) was only slightly lower than that of males (60–63%); juvenile survival was 41% but was paired with a low (13%) encounter probability. We attribute the lack of sex bias in adult dispersal to this species' polygynandrous mating strategy. Within this system, there are multiple mates within a breeding neighborhood. We argue that natural selection may favor females that remain on the same, familiar breeding site, because they do not have to disperse to a new area to find a suitable mate. Dispersal among breeding populations most likely occurs by juveniles returning as adults. Our findings support hypotheses that suggest a relationship between dispersal and mating strategy and provide some of the first insight into the demographic patterns of a polygynandrous passerine.

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

    Treesearch

    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...

  15. Graphene Nanobubbles as Valley Filters and Beam Splitters

    NASA Astrophysics Data System (ADS)

    Settnes, Mikkel; Power, Stephen R.; Brandbyge, Mads; Jauho, Antti-Pekka

    2016-12-01

    The energy band structure of graphene has two inequivalent valleys at the K and K' points of the Brillouin zone. The possibility to manipulate this valley degree of freedom defines the field of valleytronics, the valley analogue of spintronics. A key requirement for valleytronic devices is the ability to break the valley degeneracy by filtering and spatially splitting valleys to generate valley polarized currents. Here, we suggest a way to obtain valley polarization using strain-induced inhomogeneous pseudomagnetic fields (PMFs) that act oppositely on the two valleys. Notably, the suggested method does not involve external magnetic fields, or magnetic materials, unlike previous proposals. In our proposal the strain is due to experimentally feasible nanobubbles, whose associated PMFs lead to different real space trajectories for K and K' electrons, thus allowing the two valleys to be addressed individually. In this way, graphene nanobubbles can be exploited in both valley filtering and valley splitting devices, and our simulations reveal that a number of different functionalities are possible depending on the deformation field.

  16. Regional-scale input of dispersed and discrete volcanic ash to the Izu-Bonin and Mariana subduction zones

    NASA Astrophysics Data System (ADS)

    Scudder, Rachel P.; Murray, Richard W.; Schindlbeck, Julie C.; Kutterolf, Steffen; Hauff, Folkmar; McKinley, Claire C.

    2014-11-01

    We have geochemically and statistically characterized bulk marine sediment and ash layers at Ocean Drilling Program Site 1149 (Izu-Bonin Arc) and Deep Sea Drilling Project Site 52 (Mariana Arc), and have quantified that multiple dispersed ash sources collectively comprise ˜30-35% of the hemipelagic sediment mass entering the Izu-Bonin-Mariana subduction system. Multivariate statistical analyses indicate that the bulk sediment at Site 1149 is a mixture of Chinese Loess, a second compositionally distinct eolian source, a dispersed mafic ash, and a dispersed felsic ash. We interpret the source of these ashes as, respectively, being basalt from the Izu-Bonin Front Arc (IBFA) and rhyolite from the Honshu Arc. Sr-, Nd-, and Pb isotopic analyses of the bulk sediment are consistent with the chemical/statistical-based interpretations. Comparison of the mass accumulation rate of the dispersed ash component to discrete ash layer parameters (thickness, sedimentation rate, and number of layers) suggests that eruption frequency, rather than eruption size, drives the dispersed ash record. At Site 52, the geochemistry and statistical modeling indicates that Chinese Loess, IBFA, dispersed BNN (boninite from Izu-Bonin), and a dispersed felsic ash of unknown origin are the sources. At Site 1149, the ash layers and the dispersed ash are compositionally coupled, whereas at Site 52 they are decoupled in that there are no boninite layers, yet boninite is dispersed within the sediment. Changes in the volcanic and eolian inputs through time indicate strong arc-related and climate-related controls.

  17. Zeolite Formation and Weathering Processes in Dry Valleys of Antartica: Martian Analogs

    NASA Technical Reports Server (NTRS)

    Gibson, E. K., Jr.; Wentworth, S. J.; McKay, D. S.; Socki, R. A.

    2004-01-01

    Terrestrial weathering processes in cold-desert climates such as the Dry Valleys of Antarctica may provide an excellent analog to chemical weathering and diagenesis of soils on Mars. Detailed studies of soil development and the chemical and mineralogical alterations occurring within soil columns in Wright Valley, Antarctica show incredible complexity in the upper meter of soil. Previous workers noted the ice-free Dry Valleys are the best terrestrial approximations to contemporary Mars. Images returned from the Pathfinder and Spirit landers show similarities to surfaces observed within the Dry Valleys. Similarities to Mars that exist in these valleys are: mean temperatures always below freezing (-20 C), no rainfall, sparse snowfall-rapidly removed by sublimation, desiccating winds, diurnal freeze-thaw cycles (even during daylight hours), low humidity, oxidative environment, relatively high solar radiation and low magnetic fields . The Dry Valley soils contain irregular distributions and low abundances of soil microorganisms that are somewhat unusual on Earth. Physical processes-such as sand abrasion-are dominant mechanisms of rock weathering in Antarctica. However, chemical weathering is also an important process even in such extreme climates. For example, ionic migration occurs even in frozen soils along liquid films on individual soil particles. It has also been shown that water with liquid-like properties is present in soils at temperatures on the order of approx.-80 C and it has been observed that the percentage of oxidized iron increases with increasing soil age and enrichments in oxidized iron occurs toward the surface. The presence of evaporates is evident and appear similar to "evaporite sites" within the Pathfinder and Spirit sites. Evaporites indicate ionic migration and chemical activity even in the permanently frozen zone. The presence of evaporates indicates that chemical weathering of rocks and possibly soils has been active. Authogenic zeolites have

  18. 77 FR 6586 - GE Oil & Gas Operations, LLC Including On-Site Leased Workers From Adecco, Argus Technical, Inc...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-08

    ..., LLC Including On-Site Leased Workers From Adecco, Argus Technical, Inc., Fox Valley Metrology URS Corp... the certification for workers of the subject firm. New information shows that workers leased from Fox... from Fox Valley Metrology, URS Corp. and CompuCom working on-site at the Oshkosh, Wisconsin location of...

  19. A preliminary investigation of the variables affecting the distribution of giant gartersnakes (Thamnophis gigas) in the Sacramento Valley, California

    USGS Publications Warehouse

    Halstead, Brian J.; Skalos, Shannon M.; Casazza, Michael L.; Wylie, Glenn D.

    2015-09-30

    Giant gartersnakes (Thamnophis gigas) comprise a species of rare, semi-aquatic snake precinctive to the Central Valley of California. Because of the loss of more than 90% of their natural habitat, giant gartersnakes are listed as Threatened by the United States and California endangered species acts. Little is known, however, about the distribution of giant gartersnakes in the Sacramento Valley, which is where most extant populations occur. We conducted detection-nondetection surveys for giant gartersnakes throughout the rice-growing regions of the Sacramento Valley, and used occupancy models to examine evidence for the effects of landscape-scale GIS-derived variables, local habitat and vegetation composition, and prey communities on patterns of giant gartersnake occurrence. Although our results are based on a relatively small sample of sites, we found that distance to historic marsh, relative fish count, and an interaction of distance to historic marsh with proportion of habitat composed of submerged vegetation were important variables for explaining occupancy of giant gartersnakes. In particular, giant gartersnakes were more likely to occur closer to historic marsh and where relatively fewer fish were captured in traps. At locations in or near historic marsh, giant gartersnakes were more likely to occur in areas with less submerged vegetation, but this relationship was reversed (and more uncertain) at sites distant from historic marsh. Additional research with a larger sample of sites would further elucidate the distribution of giant gartersnakes in the Sacramento Valley.

  20. Infilling and flooding of the Mekong River incised valley during deglacial sea-level rise

    NASA Astrophysics Data System (ADS)

    Tjallingii, Rik; Stattegger, Karl; Wetzel, Andreas; Van Phach, Phung

    2010-06-01

    The abrupt transition from fluvial to marine deposition of incised-valley-fill sediments retrieved from the southeast Vietnamese shelf, accurately records the postglacial transgression after 14 ka before present (BP). Valley-filling sediments consist of fluvial mud, whereas sedimentation after the transgression is characterized by shallow-marine carbonate sands. This change in sediment composition is accurately marked in high-resolution X-ray fluorescence (XRF) core scanning records. Rapid aggradation of fluvial sediments at the river mouth nearly completely filled the Mekong incised valley prior to flooding. However, accumulation rates strongly reduced in the valley after the river-mouth system flooded and stepped back. This also affected the sediment supply to deeper parts of the southeast Vietnamese shelf. Comparison of the Mekong valley-filling with the East Asian sea-level history of sub- and inter-tidal sediment records shows that the transgressive surface preserved in the incised-valley-fill records is a robust sea-level indicator. The valley was nearly completely filled with fluvial sediments between 13.0 and 9.5 ka BP when sea-level rose rather constantly with approximately 10 mm/yr, as indicated by the East Asian sea-level record. At shallower parts of the shelf, significant sediment reworking and the establishment of estuarine conditions at the final stage of infilling complicates accurate dating of the transgressive surface. Nevertheless, incised-valley-fill records and land-based drill sites indicate a vast and rapid flooding of the shelf from the location of the modern Vietnamese coastline to the Cambodian lowlands between 9.5 ka and 8.5 ka BP. Fast flooding of this part of the shelf is related with the low shelf gradient and a strong acceleration of the East Asian sea-level rise from 34 to 9 meter below modern sea level (mbsl) corresponding to the sea-level jump of melt water pulse (MWP) 1C.

  1. Pattern of ground deformation in Kathmandu valley during 2015 Gorkha Earthquake, central Nepal

    NASA Astrophysics Data System (ADS)

    Ghimire, S.; Dwivedi, S. K.; Acharya, K. K.

    2016-12-01

    The 25th April 2015 Gorkha Earthquake (Mw=7.8) epicentered at Barpak along with thousands of aftershocks released seismic moment nearly equivalent to an 8.0 Magnitude earthquake rupturing a 150km long fault segment. Although Kathmandu valley was supposed to be severely devastated by such major earthquake, post earthquake scenario is completely different. The observed destruction is far less than anticipated as well as the spatial pattern is different than expected. This work focuses on the behavior of Kathmandu valley sediments during the strong shaking by the 2015 Gorkha Earthquake. For this purpose spatial pattern of destruction is analyzed at heavily destructed sites. To understand characteristics of subsurface soil 2D-MASW survey was carried out using a 24-channel seismograph system. An accellerogram recorded by Nepal Seismological Center was analyzed to characterize the strong ground motion. The Kathmandu valley comprises fluvio-lacustrine deposit with gravel, sand, silt and clay along with few exposures of basement rocks within the sediments. The observations show systematic repetition of destruction at an average interval of 2.5km mostly in sand, silt and clay dominated formations. Results of 2D-MASW show the sites of destruction are characterized by static deformation of soil (liquefaction and southerly dipping cracks). Spectral analysis of the accelerogram indicates maximum power associated with frequency of 1.0Hz. The result of this study explains the observed spatial pattern of destruction in Kathmandu valley. This is correlated with the seismic energy associated with the frequency of 1Hz, which generates an average wavelength of 2.5km with an average S-wave velocity of 2.5km/s. The cumulative effect of dominant frequency and associated wavelength resulted in static deformation of surface soil layers at an average interval of 2.5km. This phenomenon clearly describes the reason for different scenario than that was anticipated in Kathmandu valley.

  2. Monitoring of heavy flooding by orbital remote sensing: The example of the Doce river valley. [Doce River Valley, Brazil

    NASA Technical Reports Server (NTRS)

    Dejesusparada, N. (Principal Investigator); Novo, E. M. L. D.; Dossantos, A. P.

    1981-01-01

    The application of temporal LANDSAT data to study floods was verified, and the natural features responsible for this phenomenon were surveyed using the Doce river valley as a test site, because of the catastrophic (1978-1979) flood. Data from LANDSAT images and CCT's were used. Geomorphical mapping evaluated morphostructural features. Seven and nine classes of water surfaces for dry and rainy seasons were analyzed. The magnitude of the changes from preflood to postflood stage are estimated. The single Pixel program was applied to correlate the drainage basin characteristics to the grey level of LANDSAT data.

  3. Seasonal Variability of PM2.5, BC, and PM2.5 Chemical Characteristics at Busy Roadways in Kathmandu Valley, Nepal

    NASA Astrophysics Data System (ADS)

    Shakya, K. M.; Rupakheti, M.; Peltier, R.

    2016-12-01

    Kathmandu valley located in the foothills of Himalaya in Nepal suffers from serious air pollution problems. Near-roadway PM2.5 and BC were measured at six sites in the Kathmandu valley using a portable scattering nephelometer (pDR-1500, Thermo Inc., US) and a microaethalometer (Aeth Labs, US), respectively. 37 mm polytetrafluoroethylene filter samples were analyzed by a laboratory-based X-ray fluorescence (XRF) spectrometer (QUANT'X, Thermo Inc., US) for elements, with subsequent filter extraction in deionized water followed by ion chromatography (ICS-1100, Thermo Inc., US) for water-soluble ions. PM2.5 concentrations at six different locations in the Kathmandu Valley, Nepal showed distinct seasonal variability. There was a reduction of 57-74% in PM2.5 levels during the monsoonal period (July 20 - August 22, 2014) compared to the drier winter season (February 16 - April 4, 2014). Daily means of PM2.5 were 124.76 and 45.92 μg/m3 during winter and monsoon, respectively. BC concentrations, however, were marginally reduced during the monsoon (13.46 μgC/m3) compared to that in winter (16.74 μgC/m3). Four sites located along a busy commercial ring road had higher PM2.5 levels than the two sites located inside the ring road. Chemical analysis of 24 hour PM2.5 filter samples shows dust and traffic sources as the most important PM emission source at these locations. Silica, calcium, aluminum, and iron were the most abundant elements during both winter and monsoon, with the total concentrations of 12.13 and 8.85 μg/m3, respectively. Coefficient of divergence calculated from the four main sites resulted in more heterogeneity for chemical species compared to PM2.5 and BC. This suggests though PM2.5 and BC levels might be similar in the valley, their emission sources and production might differ across the valley. Our findings provide important insights on physical and chemical characteristics of particulate matter and its sources, which will be useful in designing

  4. Geohydrology and Water Quality of the Valley-Fill Aquifer System in the Upper Sixmile Creek and West Branch Owego Creek Valleys in the Town of Caroline, Tompkins County, New York

    USGS Publications Warehouse

    Miller, Todd S.

    2009-01-01

    , a school, and several farms and small businesses. Most groundwater that is withdrawn from pumped wells is returned to the groundwater system via septic systems. Groundwater in the upper and basal confined aquifers in the upper Sixmile Creek valley is under artesian conditions everywhere except where the water discharges to springs along bluffs in the western end of the Sixmile Creek valley. Principal sources of recharge to the confined aquifers are (1) the sides of the valley where the confined aquifers may extend up along the flank of the bedrock valley wall and crop out at land surface or are overlain and in contact with surficial coarse-grained deltaic and fluvial sediments that provide a pathway through which direct precipitation and seepage losses from tributary streams can reach the buried aquifers, or (2) where the buried aquifers are isolated and receive recharge only from adjacent fine-grained sediment and bedrock. The base-flow and runoff components of total streamflow at two streamgages, Sixmile Creek at Brooktondale and Sixmile Creek at Bethel Grove, were calculated using hydrograph-separation techniques from 2003 to 2007 discharge records. Base flow constituted 64 and 56 percent of the total annual flow at the Brooktondale and Bethel Grove streamgages, respectively. Water-quality samples were collected from 2003 to 2005, with 10 surface-water samples collected seasonally during base-flow conditions at the Sixmile Creek at Brooktondale streamgage, and 12 samples were collected during base-flow conditions at several selected tributaries from 2004 to 2005. The predominant cation detected in the surface-water samples was calcium, but moderate amounts of magnesium, silica, and sodium were also detected; the major anions were bicarbonate, chloride, and sulfate. Sodium and chloride concentrations were relatively low in all samples but increased downstream from the Sixmile Creek sampling site at Six Hundred Road near Slaterville Springs, NY, to B

  5. The Long Valley Caldera GIS database

    USGS Publications Warehouse

    Battaglia, Maurizio; Williams, M.J.; Venezky, D.Y.; Hill, D.P.; Langbein, J.O.; Farrar, C.D.; Howle, J.F.; Sneed, M.; Segall, P.

    2003-01-01

    This database provides an overview of the studies being conducted by the Long Valley Observatory in eastern California from 1975 to 2001. The database includes geologic, monitoring, and topographic datasets related to Long Valley caldera. The CD-ROM contains a scan of the original geologic map of the Long Valley region by R. Bailey. Real-time data of the current activity of the caldera (including earthquakes, ground deformation and the release of volcanic gas), information about volcanic hazards and the USGS response plan are available online at the Long Valley observatory web page (http://lvo.wr.usgs.gov). If you have any comments or questions about this database, please contact the Scientist in Charge of the Long Valley observatory.

  6. A model for long-distance dispersal of boll weevils (Coleoptera: Curculionidae)

    NASA Astrophysics Data System (ADS)

    Westbrook, John K.; Eyster, Ritchie S.; Allen, Charles T.

    2011-07-01

    The boll weevil, Anthonomus grandis (Boheman), has been a major insect pest of cotton production in the US, accounting for yield losses and control costs on the order of several billion US dollars since the introduction of the pest in 1892. Boll weevil eradication programs have eliminated reproducing populations in nearly 94%, and progressed toward eradication within the remaining 6%, of cotton production areas. However, the ability of weevils to disperse and reinfest eradicated zones threatens to undermine the previous investment toward eradication of this pest. In this study, the HYSPLIT atmospheric dispersion model was used to simulate daily wind-aided dispersal of weevils from the Lower Rio Grande Valley (LRGV) of southern Texas and northeastern Mexico. Simulated weevil dispersal was compared with weekly capture of weevils in pheromone traps along highway trap lines between the LRGV and the South Texas / Winter Garden zone of the Texas Boll Weevil Eradication Program. A logistic regression model was fit to the probability of capturing at least one weevil in individual pheromone traps relative to specific values of simulated weevil dispersal, which resulted in 60.4% concordance, 21.3% discordance, and 18.3% ties in estimating captures and non-captures. During the first full year of active eradication with widespread insecticide applications in 2006, the dispersal model accurately estimated 71.8%, erroneously estimated 12.5%, and tied 15.7% of capture and non-capture events. Model simulations provide a temporal risk assessment over large areas of weevil reinfestation resulting from dispersal by prevailing winds. Eradication program managers can use the model risk assessment information to effectively schedule and target enhanced trapping, crop scouting, and insecticide applications.

  7. A model for long-distance dispersal of boll weevils (Coleoptera: Curculionidae).

    PubMed

    Westbrook, John K; Eyster, Ritchie S; Allen, Charles T

    2011-07-01

    The boll weevil, Anthonomus grandis (Boheman), has been a major insect pest of cotton production in the US, accounting for yield losses and control costs on the order of several billion US dollars since the introduction of the pest in 1892. Boll weevil eradication programs have eliminated reproducing populations in nearly 94%, and progressed toward eradication within the remaining 6%, of cotton production areas. However, the ability of weevils to disperse and reinfest eradicated zones threatens to undermine the previous investment toward eradication of this pest. In this study, the HYSPLIT atmospheric dispersion model was used to simulate daily wind-aided dispersal of weevils from the Lower Rio Grande Valley (LRGV) of southern Texas and northeastern Mexico. Simulated weevil dispersal was compared with weekly capture of weevils in pheromone traps along highway trap lines between the LRGV and the South Texas/Winter Garden zone of the Texas Boll Weevil Eradication Program. A logistic regression model was fit to the probability of capturing at least one weevil in individual pheromone traps relative to specific values of simulated weevil dispersal, which resulted in 60.4% concordance, 21.3% discordance, and 18.3% ties in estimating captures and non-captures. During the first full year of active eradication with widespread insecticide applications in 2006, the dispersal model accurately estimated 71.8%, erroneously estimated 12.5%, and tied 15.7% of capture and non-capture events. Model simulations provide a temporal risk assessment over large areas of weevil reinfestation resulting from dispersal by prevailing winds. Eradication program managers can use the model risk assessment information to effectively schedule and target enhanced trapping, crop scouting, and insecticide applications.

  8. Analyzing tree cores to detect petroleum hydrocarbon-contaminated groundwater at a former landfill site in the community of Happy Valley-Goose Bay, eastern Canadian subarctic.

    PubMed

    Fonkwe, Merline L D; Trapp, Stefan

    2016-08-01

    This research examines the feasibility of analyzing tree cores to detect benzene, toluene, ethylbenzene, and m, p, o-xylene (BTEX) compounds and methyl tertiary-butyl ether (MTBE) in groundwater in eastern Canada subarctic environments, using a former landfill site in the remote community of Happy Valley-Goose Bay, Labrador. Petroleum hydrocarbon contamination at the landfill site is the result of environmentally unsound pre-1990s disposal of households and industrial solid wastes. Tree cores were taken from trembling aspen, black spruce, and white birch and analyzed by headspace-gas chromatography-mass spectrometry. BTEX compounds were detected in tree cores, corroborating known groundwater contamination. A zone of anomalously high concentrations of total BTEX constituents was identified and recommended for monitoring by groundwater wells. Tree cores collected outside the landfill site at a local control area suggest the migration of contaminants off-site. Tree species exhibit different concentrations of BTEX constituents, indicating selective uptake and accumulation. Toluene in wood exhibited the highest concentrations, which may also be due to endogenous production. Meanwhile, MTBE was not found in the tree cores and is considered to be absent in the groundwater. The results demonstrate that tree-core analysis can be useful for detecting anomalous concentrations of petroleum hydrocarbons, such as BTEX compounds, in subarctic sites with shallow unconfined aquifers and permeable soils. This method can therefore aid in the proper management of contamination during landfill operations and after site closures.

  9. Fuel regulation in inland navigation: reduced soil black carbon and PAH deposition in river valleys

    NASA Astrophysics Data System (ADS)

    Bläsing, M.; Schwark, L.; Amelung, W.; Lehndorff, E.

    2016-12-01

    Inland navigation (IN) is of increasing importance in the transport sector. Most inland waterways and inland ports are located in/near urban regions; hence many people are exposed to emissions from IN. However, its contribution to environmental quality is not yet known. Accordingly, we aimed at identifying IN emissions in the environment, and investigating consequences of the S-reduction in ship diesel (EU regulation 2009/30/EC) on IN emissions. To do so, topsoil samples were taken from vineyards in valley transects (perpendicular to rivers) at two German inland waterways (Rhine, Moselle) and one ship-free reference valley (Ahr) and analyzed for polycyclic aromatic hydrocarbons (PAHs) and black carbon (BC). To elucidate the effect of fuel regulation (effective since 2011), samplings were performed from 2010 to 2013. Additionally, the potential dispersal of IN emissions was simulated by a Lagrangian stochastic model. Before regulating the S-content of ship diesel by the EU directive soil samples indicated a clear impact of IN emissions on BC and PAH deposits, in at least 200 and 350 m distance to the Moselle and Rhine river, respectively. IN emissions accounted for approximately 30% of total soil BC. However, soils along waterways comprised only slightly more BC than soils in the ship-free Ahr Valley, with BC contents comparable to rural to suburban European soils. Contents of PAHs in river valleys compared to remote to urban pollution load. In the course of the fuel regulation, BC and PAH deposits in soil were reduced within three years by 30-60%, respectively. Also the quality of emissions changed to higher shares of low molecular weight PAHs and smaller proportions of soot-BC, indicating less deposition of IN emissions. The impact of the fuel regulation was more obvious at the Rhine Valley than at the Moselle Valley, likely because of higher ship traffic volume at the former. Overall, fuel regulation was effective in reducing IN emissions along inland waterways.

  10. Bottomland Forests in the Lower Mississippi Alluvial Valley associated with the endangered Lindera melissifolia

    Treesearch

    Tracy S. Hawkins; Daniel A. Skojac; Brian R. Lockhart; Theodor D. Leininger; Margaret S. Devall; Nathan M. Shiff

    2009-01-01

    Forest canopy and subcanopy data were collected from and compared amongfive disjunct bottomland hardwood forests in the Lower Mississippi Alluvial Valley, each withknown occurrence of a population of the federally endangered shrub Lindera melissifolia. Allstudy sites are cut-over forests, underlain by...

  11. Modelling the Crust beneath the Kashmir valley in Northwestern Himalaya

    NASA Astrophysics Data System (ADS)

    Mir, R. R.; Parvez, I. A.; Gaur, V. K.; A.; Chandra, R.; Romshoo, S. A.

    2015-12-01

    We investigate the crustal structure beneath five broadband seismic stations in the NW-SE trendingoval shaped Kashmir valley sandwiched between the Zanskar and the Pir Panjal ranges of thenorthwestern Himalaya. Three of these sites were located along the southwestern edge of the valley andthe other two adjoined the southeastern. Receiver Functions (RFs) at these sites were calculated usingthe iterative time domain deconvolution method and jointly inverted with surface wave dispersiondata to estimate the shear wave velocity structure beneath each station. To further test the results ofinversion, we applied forward modelling by dividing the crust beneath each station into 4-6homogeneous, isotropic layers. Moho depths were separately calculated at different piercing pointsfrom the inversion of only a few stacked receiver functions of high quality around each piercing point.These uncertainties were further reduced to ±2 km by trial forward modelling as Moho depths werevaried over a range of ±6 km in steps of 2 km and the synthetic receiver functions matched with theinverted ones. The final values were also found to be close to those independently estimated using theH-K stacks. The Moho depths on the eastern edge of the valley and at piercing points in itssouthwestern half are close to 55 km, but increase to about 58 km on the eastern edge, suggesting thathere, as in the central and Nepal Himalaya, the Indian plate dips northeastwards beneath the Himalaya.We also calculated the Vp/Vs ratio beneath these 5 stations which were found to lie between 1.7 and1.76, yielding a Poisson's ratio of ~0.25 which is characteristic of a felsic composition.

  12. 27 CFR 9.78 - Ohio River Valley.

    Code of Federal Regulations, 2010 CFR

    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...

  13. Valley dependent transport in graphene L junction

    NASA Astrophysics Data System (ADS)

    Chan, K. S.

    2018-05-01

    We studied the valley dependent transport in graphene L junctions connecting an armchair lead and a zigzag lead. The junction can be used in valleytronic devices and circuits. Electrons injected from the armchair lead into the junction is not valley polarized, but they can become valley polarized in the zigzag lead. There are Fermi energies, where the current in the zigzag lead is highly valley polarized and the junction is an efficient generator of valley polarized current. The features of the valley polarized current depend sensitively on the widths of the two leads, as well as the number of dimers in the armchair lead, because this number has a sensitive effect on the band structure of the armchair lead. When an external potential is applied to the junction, the energy range with high valley polarization is enlarged enhancing its function as a generator of highly valley polarized current. The scaling behavior found in other graphene devices is also found in L junctions, which means that the results presented here can be extended to junctions with larger dimensions after appropriate scaling of the energy.

  14. Rift Valley fever.

    PubMed

    Paweska, J T

    2015-08-01

    Rift Valley fever (RVF) is a mosquito-borne zoonotic viral disease affecting domestic and wild ruminants, camels and humans. The causative agent of RVF, the RVF virus (RVFV), has the capacity to cause large and severe outbreaks in animal and human populations and to cross significant natural geographic barriers. Rift Valley fever is usually inapparent in non-pregnant adult animals, but pregnant animals and newborns can be severely affected; outbreaks are characterised by a sudden onset of abortions and high neonatal mortality. The majority of human infections are subclinical or associated with moderate to severe, non-fatal, febrile illness, but some patients may develop a haemorrhagic syndrome and/or ocular and neurological lesions. In both animals and humans, the primary site of RVFV replication and tissue pathology is the liver. Outbreaks of RVF are associated with persistent high rainfalls leading to massive flooding and the emergence of large numbers of competent mosquito vectors that transmit the virus to a wide range of susceptible vertebrate species. Outbreaks of RVF have devastating economic effects on countries for which animal trade constitutes the main source of national revenue. The propensity of the virus to spread into new territories and re-emerge in traditionally endemic regions, where it causes large outbreaks in human and animal populations, presents a formidable challenge for public and veterinary health authorities. The presence of competent mosquito vectors in RVF-free countries, the wide range of mammals susceptible to the virus, altering land use, the global changes in climate, and increased animal trade and travel are some of the factors which might contribute to international spread of RVF.

  15. Abundance and sexual size dimorphism of the giant gartersnake (Thamnophis gigas) in the Sacramento valley of California

    USGS Publications Warehouse

    Wylie, G.D.; Casazza, Michael L.; Gregory, C.J.; Halstead, B.J.

    2010-01-01

    The Giant Gartersnake (Thamnophis gigas) is restricted to wetlands of the Central Valley of California. Because of wetland loss in this region, the Giant Gartersnake is both federally and state listed as threatened. We conducted markrecapture studies of four populations of the Giant Gartersnake in the Sacramento Valley (northern Central Valley), California, to obtain baseline data on abundance and density to assist in recovery planning for this species. We sampled habitats that ranged from natural, unmanaged marsh to constructed managed marshes and habitats associated with rice agriculture. Giant Gartersnake density in a natural wetland (1.90 individuals/ha) was an order of magnitude greater than in a managed wetland subject to active season drying (0.17 individuals/ha). Sex ratios at all sites were not different from 1 1, and females were longer and heavier than males. Females had greater body condition than males, and individuals at the least disturbed sites had significantly greater body condition than individuals at the managed wetland. The few remaining natural wetlands in the Central Valley are important, productive habitat for the Giant Gartersnake, and should be conserved and protected. Wetlands constructed and restored for the Giant Gartersnake should be modeled after the permanent, shallow wetlands representative of historic Giant Gartersnake habitat. ?? 2010 Society for the Study of Amphibians and Reptiles.

  16. Down in the Valley.

    ERIC Educational Resources Information Center

    Salter, Linda Graef

    1999-01-01

    Describes the partnerships formed by West Valley Mission Community College District (California) with its surrounding Silicon Valley business community in an effort to benefit workforce development. Asserts that community colleges are uniquely positioned to provide a lifelong education that will yield a skilled workforce to meet the needs of…

  17. Introduced birds incompletely replace seed dispersal by a native frugivore

    PubMed Central

    Pejchar, Liba

    2015-01-01

    The widespread loss of native species and the introduction of non-native species has important consequences for island ecosystems. Non-native species may or may not functionally replace the role of native species in ecological processes such as seed dispersal. Although the majority of Hawaii's native plants require bird-mediated seed dispersal, only one native frugivore, Omao (Myadestes obscurus), persists in sufficient numbers to fill this functional role. Omao are restricted to less than half their original range, but two introduced frugivores are abundant throughout Hawaii. Given large-scale extinctions on islands, it is important to understand whether introduced birds serve as functional replacements or whether the absence of native frugivores alters plant communities. To assess seed dispersal by native and introduced birds, seed rain, vegetation characteristics, bird diet, density and habitat use were measured at three sites with Omao and three sites without Omao on Hawaii Island. The diet of native and introduced birds overlapped substantially, but Omao dispersed a variety of native species (n = 6) relatively evenly. In contrast, introduced birds dispersed an invasive species and fewer native species (n = 4), and >90 % of seeds dispersed by introduced birds were from two ubiquitous small-seeded species. Seed rain was significantly greater and more species rich at sites with Omao. These findings suggest that patterns of seed dispersal are altered following the local extinction of a native island frugivore. To more directly evaluate the relative roles of native and introduced frugivores in ecological processes, future studies could include reintroducing Omao to a suitable habitat within its historic range, or novel introductions to nearby islands where closely related species are now extinct. In an era of widespread extinction and invasion of island ecosystems, understanding the consequences of novel animal assemblages for processes like seed dispersal will be

  18. Site Response and Basin Waves in the Sacramento–San Joaquin Delta, California

    USGS Publications Warehouse

    Fletcher, Jon Peter B.; Boatwright, John

    2013-01-01

    The Sacramento–San Joaquin Delta is an inland delta at the western extent of the Central Valley. Levees were built around swampy islands starting after the Civil War to reclaim these lands for farming. Various studies show that these levees could fail in concert from shaking from a major local or regional earthquake resulting in salty water from the San Francisco Bay contaminating the water in the Delta. We installed seismographs around the Delta and on levees to assess the contribution of site response to the seismic hazard of the levees. Cone penetrometer testing shows that the upper 10 s of meters of soil in the Delta have shear‐wave velocities of about 200  m/s, which would give a strong site response. Seismographs were sited following two strategies: pairs of stations to compare the response of the levees to nearby sites, and a more regional deployment in the Delta. Site response was determined in two different ways: a traditional spectral ratio (TSR) approach of S waves using station BDM of the Berkeley Digital Seismic Net as a reference site, and using SH/SV ratios of noise (or Nakamura’s method). Both estimates usually agree in spectral character for stations whose response is dominated by a resonant peak, but the most obvious peaks in the SH/SV ratios usually are about two‐thirds as large as the main peaks in the TSRs. Levee sites typically have large narrow resonances in the site response function compared to sites in the farmland of the Delta. These resonances, at a frequency of about 1–3 Hz, have amplitudes of about 15 with TSR and 10–12 with Nakamura’s method. Sites on farmland in the Delta also have amplifications, but these are typically broader and not as resonant in appearance. Late (slow) Rayleigh waves were recorded at stations in the Delta, have a dominant period of about one second, and are highly monochromatic. Results from a three‐station array at the Holland Marina suggest that they have a phase velocity of about

  19. Geological Carbon Sequestration in the Ohio River Valley: An Evaluation of Possible Target Formations

    NASA Astrophysics Data System (ADS)

    Dalton, T. A.; Daniels, J. J.

    2009-12-01

    The development of geological carbon sequestration within the Ohio River Valley is of major interest to the national electricity and coal industries because the Valley is home to a heavy concentration of coal-burning electricity generation plants and the infrastructure is impossible to eliminate in the short-term. It has been determined by Ohio's politicians and citizenry that the continued use of coal in this region until alternative energy supplies are available will be necessary over the next few years. Geologic sequestration is the only possible means of keeping the CO2 out of the atmosphere in the region. The cost of the sequestration effort greatly decreases CO2 emissions by sequestering CO2 directly on site of these plants, or by minimizing the distance between fossil-fueled generation and sequestration (i.e., by eliminating the cost of transportation of supercritical CO2 from plant to sequestration site). Thus, the practicality of CO2 geologic sequestration within the Ohio River Valley is central to the development of such a commercial effort. Though extensive work has been done by the Regional Partnerships of the DOE/NETL in the characterization of general areas for carbon sequestration throughout the nation, few projects have narrowed their focus into a single geologic region in order to evaluate the sites of greatest commercial potential. As an undergraduate of the Earth Sciences at Ohio State, I have engaged in thorough research to obtain a detailed understanding of the geology of the Ohio River Valley and its potential for commercial-scale carbon sequestration. Through this research, I have been able to offer an estimate of the areas of greatest interest for CO2 geologic sequestration. This research has involved petrological, mineralogical, geochemical, and geophysical analyses of four major reservoir formations within Ohio—the Rose Run, the Copper Ridge, the Clinton, and the Oriskany—along with an evaluation of the possible effects of injection

  20. Mars Exploration Rovers Landing Dispersion Analysis

    NASA Technical Reports Server (NTRS)

    Knocke, Philip C.; Wawrzyniak, Geoffrey G.; Kennedy, Brian M.; Desai, Prasun N.; Parker, TImothy J.; Golombek, Matthew P.; Duxbury, Thomas C.; Kass, David M.

    2004-01-01

    Landing dispersion estimates for the Mars Exploration Rover missions were key elements in the site targeting process and in the evaluation of landing risk. This paper addresses the process and results of the landing dispersion analyses performed for both Spirit and Opportunity. The several contributors to landing dispersions (navigation and atmospheric uncertainties, spacecraft modeling, winds, and margins) are discussed, as are the analysis tools used. JPL's MarsLS program, a MATLAB-based landing dispersion visualization and statistical analysis tool, was used to calculate the probability of landing within hazardous areas. By convolving this with the probability of landing within flight system limits (in-spec landing) for each hazard area, a single overall measure of landing risk was calculated for each landing ellipse. In-spec probability contours were also generated, allowing a more synoptic view of site risks, illustrating the sensitivity to changes in landing location, and quantifying the possible consequences of anomalies such as incomplete maneuvers. Data and products required to support these analyses are described, including the landing footprints calculated by NASA Langley's POST program and JPL's AEPL program, cartographically registered base maps and hazard maps, and flight system estimates of in-spec landing probabilities for each hazard terrain type. Various factors encountered during operations, including evolving navigation estimates and changing atmospheric models, are discussed and final landing points are compared with approach estimates.

  1. The development and adaption of early agriculture in Huanghe River Valley, China

    NASA Astrophysics Data System (ADS)

    Li, X.

    2017-12-01

    The expanding and developing of agriculture are the basic of population growth, the expansions of material cultures and civilization. The Huanghe River valley, as the origin center of millet agriculture, lies between the heartlands of wheat and rice, which gestates the flourishing Neolithic culture based on agriculture. Recent work using botanical remains has greatly expanded the knowledge concerning early agriculture. Here, we report the new progress on the development and adaption of early agriculture in Huanghe River valley and the surrounding areas. Based on the analysis of phytolith from 13 sites in middle reaches of Huanghe River and the survey of crop seeds from 5 sites in Guanzhong Basin, the rice have been cultivated around 7600 cal BP in semi-humid regions dominated by rain-fed agriculture. The mixed agriculture of common millet, foxtail millet, and rice continued to exist between 7600-3500 BP. In semi-arid region of Huanghe River valley, the agriculture was dominated by the production of common and foxtail millet and 3 major changes have taken place around 6500 BP, 5500 BP, and 4000 BP during Neolithic. The cultivating ratio of common and foxtail millet was adjusted by farmer for adapting the climate changes during Holocene. Approximately 5000 yr BP, the rain-fed agriculture continues to break geographical boundaries to expand to west and southwest from Huanghe River valley. Millet agriculture appeared in southern Ganshu and north eastern Tibetan Plateau. The common and foxtail millet spread to the arid-area of Hexi corridor, a major crossroad of the famous Silk Road, around 4500 yr BP. Wheat was added as a new crop to the existing millet based agricultural systems around 4100-4000 cal yr BP in Hexi corridor. Between 3800 and 3400 cal yr BP, the proportion of wheat and barley in agriculture was up to 90%,which have replaced the local millet and become the main crops. And now, some new evidences of wheat agriculture from NW Xijiang have been obtained and

  2. Hazardous Waste Cleanup: Western New York Nuclear Service Center in West Valley, New York

    EPA Pesticide Factsheets

    This 3,300-acre site is located at 10282 Rock Springs Road in Ashford, New York and owned by New York State Energy Research & Development Authority (NYSERDA). A 167-acre portion is operated by the U.S. Department of Energy (See “West Valley Demonstration

  3. Rift Valley Fever Virus

    USDA-ARS?s Scientific Manuscript database

    Rift Valley fever virus (RVFV) is a mosquito-transmitted virus or arbovirus that is endemic in sub-Saharan Africa. In the last decade, Rift Valley fever (RVF) outbreaks have resulted in loss of human and animal life, as well as had significant economic impact. The disease in livestock is primarily a...

  4. Evaluation of the Location and Recency of Faulting Near Prospective Surface Facilities in Midway Valley, Nye County, Nevada

    USGS Publications Warehouse

    Swan, F.H.; Wesling, J.R.; Angell, M.M.; Thomas, A.P.; Whitney, J.W.; Gibson, J.D.

    2001-01-01

    Evaluation of surface faulting that may pose a hazard to prospective surface facilities is an important element of the tectonic studies for the potential Yucca Mountain high-level radioactive waste repository in southwestern Nevada. For this purpose, a program of detailed geologic mapping and trenching was done to obtain surface and near-surface geologic data that are essential for determining the location and recency of faults at a prospective surface-facilities site located east of Exile Hill in Midway Valley, near the eastern base of Yucca Mountain. The dominant tectonic features in the Midway Valley area are the north- to northeast-trending, west-dipping normal faults that bound the Midway Valley structural block-the Bow Ridge fault on the west side of Exile Hill and the Paint-brush Canyon fault on the east side of the valley. Trenching of Quaternary sediments has exposed evidence of displacements, which demonstrate that these block-bounding faults repeatedly ruptured the surface during the middle to late Quaternary. Geologic mapping, subsurface borehole and geophysical data, and the results of trenching activities indicate the presence of north- to northeast-trending faults and northwest-trending faults in Tertiary volcanic rocks beneath alluvial and colluvial sediments near the prospective surface-facilities site. North to northeast-trending faults include the Exile Hill fault along the eastern base of Exile Hill and faults to the east beneath the surficial deposits of Midway Valley. These faults have no geomorphic expression, but two north- to northeast-trending zones of fractures exposed in excavated profiles of middle to late Pleistocene deposits at the prospective surface-facilities site appear to be associated with these faults. Northwest-trending faults include the West Portal and East Portal faults, but no disruption of Quaternary deposits by these faults is evident. The western zone of fractures is associated with the Exile Hill fault. The eastern

  5. Landing Site Dispersion Analysis and Statistical Assessment for the Mars Phoenix Lander

    NASA Technical Reports Server (NTRS)

    Bonfiglio, Eugene P.; Adams, Douglas; Craig, Lynn; Spencer, David A.; Strauss, William; Seelos, Frank P.; Seelos, Kimberly D.; Arvidson, Ray; Heet, Tabatha

    2008-01-01

    The Mars Phoenix Lander launched on August 4, 2007 and successfully landed on Mars 10 months later on May 25, 2008. Landing ellipse predicts and hazard maps were key in selecting safe surface targets for Phoenix. Hazard maps were based on terrain slopes, geomorphology maps and automated rock counts of MRO's High Resolution Imaging Science Experiment (HiRISE) images. The expected landing dispersion which led to the selection of Phoenix's surface target is discussed as well as the actual landing dispersion predicts determined during operations in the weeks, days, and hours before landing. A statistical assessment of these dispersions is performed, comparing the actual landing-safety probabilities to criteria levied by the project. Also discussed are applications for this statistical analysis which were used by the Phoenix project. These include using the statistical analysis used to verify the effectiveness of a pre-planned maneuver menu and calculating the probability of future maneuvers.

  6. Documentation of the Santa Clara Valley regional ground-water/surface-water flow model, Santa Clara Valley, California

    USGS Publications Warehouse

    Hanson, R.T.; Li, Zhen; Faunt, C.C.

    2004-01-01

    into upper- and lower-aquifer systems. Ground-water inflow occurs as natural recharge in the form of streamflow infiltration and areal infiltration of precipitation along stream channels, artificial recharge from infiltration of imported water at recharge ponds and along selected stream channels, and leakage along selected transmission pipelines. Ground-water outflow occurs as evapotranspiration, stream base flow, discharge through pumpage from wells, and subsurface flow to the San Francisco Bay. The geohydrologic framework of the regional ground-water flow system was represented as six model layers. The hydraulic properties were redefined on the basis of cell-based lithologic properties that were delineated in terms of aggregate thicknesses of coarse-grained, fine-grained, and mixed textural categories. The regional aquifer systems also are dissected by several laterally extensive faults that may form at least partial barriers to the lateral flow of ground water. The spatial extent of the ground-water flow model was extended and refined to cover the entire Santa Clara Valley, including the Evergreen subregion. The temporal discretization was refined and the period of simulation was extended to 197099. The model was upgraded to MODFLOW-2000 (MF2K) and was calibrated to fit historical ground-water levels, streamflow, and land subsidence for the period 197099. The revised model slightly overestimates measured water levels with an root-mean-square error of -7.34 feet. The streamflow generally shows a good match on gaged creeks and rivers for flows greater than 1.2 cubic feet per second. The revised model also fits the measured deformation at the borehole extensometer site located near San Jose within 16 to 27 percent and the extensometer site near Sunnyvale within 3 percent of the maximum measured seasonal deformation for the deepest extensometers. The total ground-water inflow and outflow of about 225,500 acre-feet per

  7. An evaluation of Skylab (EREP) remote sensing techniques applied to investigation of crustal structure. [Death Valley and Greenwater Valley (CA)

    NASA Technical Reports Server (NTRS)

    Bechtold, I. C. (Principal Investigator)

    1974-01-01

    The author has identified the following significant results. A study of Greenwater Valley indicates that the valley is bounded on the north and east by faults, on the south by a basement high, and on the west by the dip slope of the black mountains, movement of ground water from the valley is thus Movement of ground water from the valley is thus restricted, indicating the valley is a potential water reservoir.

  8. Valley-selective Landau-Zener oscillations in semi-Dirac p -n junctions

    NASA Astrophysics Data System (ADS)

    Saha, K.; Nandkishore, R.; Parameswaran, S. A.

    2017-07-01

    We study transport across p -n junctions of gapped two-dimensional semi-Dirac materials: nodal semimetals whose energy bands disperse quadratically and linearly along distinct crystal axes. The resulting electronic properties—relevant to materials such as TiO2/VO2 multilayers and α -(BEDT-TTF)2I3 salts—continuously interpolate between those of mono- and bilayer graphene as a function of propagation angle. We demonstrate that tunneling across the junction depends on the orientation of the tunnel barrier relative to the crystalline axes, leading to strongly nonmonotonic current-voltage characteristics, including negative differential conductance in some regimes. In multivalley systems, these features provide a natural route to engineering valley-selective transport.

  9. Directed seed dispersal of Piper by Carollia perspicillata and its effect on understory plant diversity and folivory.

    PubMed

    Salazar, Diego; Kelm, Detlev H; Salazar, Diego

    2013-11-01

    Directed dispersal occurs when seeds are differentially deposited to sites where offspring survivorship is higher than at randomly chosen sites. Traditionally, characteristics of the dispersal target sites that could increase survivorship of the dispersed plants are thought to be intrinsic to the sites. If directed dispersal is constant over extended periods of time, however, it is likely that nonrandom patterns of dispersal could modify the ecological characteristics of the target site in ways that could increase survivorship and fitness of the dispersed plants. Here we report patterns of Piper diversity (richness, equitability, and similarity) and Piper folivory within plots near natural or artificial roosts of Carollia perspicillata vs. similar plots without bat roosts. Plots with bat roosts, both natural and artificial, had significantly higher Piper species diversity. Additionally, we found that plots with a higher Piper species diversity showed less specialist folivory, higher generalist folivory, and lower total herbivore leaf damage than plots with low Piper diversity. Finally, plots with bat roosts also showed less specialist folivory, lower generalist folivory, and lower total folivory when compared to plots without roosts. We propose that long-lasting nonrandom patterns of seed dispersal can change the local ecological characteristics of target sites via changes in plant diversity, and that these changes are likely to reduce the local rates of folivory and, therefore, increase seed and adult plant survivorship.

  10. Factors influencing poststocking dispersal of razorback sucker

    USGS Publications Warehouse

    Mueller, G.A.; Marsh, P.C.; Foster, D.; Ulibarri, M.; Burke, T.

    2003-01-01

    Efforts to reintroduce razorback suckers Xyrauchen texanus to specific river reaches have been plagued by downstream drift and poor survival, which have been attributed to stress, disorientation, predation, and poor conditioning. Poststocking dispersal of eight test groups (15 fish each) of razorback suckers was examined for 28 d with telemetry equipment. Fish were released in three different locations in the Colorado River basin of Utah, Arizona, and Nevada: (1) a 65,000-ha reservoir, (2) a small (<1-ha) backwater, and (3) a large (30-ha) backwater on the mainstem river. At each location, subgroups were released immediately (reference) or held to acclimate them to the site (3–7 d) before release. Two of four subgroups for the large-backwater test were preconditioned to flow. Dispersal from the stocking sites was rapid and declined with time for all tests, as fish appeared to seek and find cover. Downstream drift was most pronounced (x = 69.5 km) from the small backwater and significantly (Kruskal–Wallis test, P < 0.01) greater than either the reservoir (x = 3.7 km) or large-backwater sites (x = 7.7 km). Site-acclimation tests were inconclusive, but downstream movement was significantly (Wilcoxon two-sample test, Z = −2.298, P < 0.01) less for fish preconditioned to flow (x = 1.9 km) compared with pond-reared fish (x = 7.7 km). We concluded that poststocking dispersal may decrease if razorback suckers are preconditioned to flow.

  11. Panorama Above 'Perseverance Valley' (Enhanced Color)

    NASA Image and Video Library

    2017-07-20

    Toward the right side of this enhanced-color scene is a broad notch in the crest of the western rim of Endeavour Crater. Wheel tracks in that area were left by NASA's Mars Exploration Rover Opportunity as it observed "Perseverance Valley" from above in the spring of 2017. The valley is a major destination for the rover's extended mission. It descends out of sight on the inner slope of the rim, extending down and eastward from that notch. Opportunity's panoramic camera (Pancam) took the component images for this view from a position outside the crater during the span of June 7 to June 19, 2017, sols 4753 to 4765 of the rover's work on Mars. This scene includes features that might have been ancient channels from water, ice or wind moving toward the notch in the rim, which might have been a spillway. Perseverance Valley, just on the other side, was likely carved by action of some fluid, such as water, water-lubricated debris, or wind. The mission is investigating to learn more about that process from evidence in place. The panorama spans about three-fourths of a full-circle view, from southeastward on the left, through westward in the middle, to northeastward on the right. High points visible on the rim of Endeavour Crater include "Winnemucca" on the left and "Cape Tribulation" on the right. Winnemucca is part of the "Cape Byron" portion of the crater rim. The horizon at far right extends across the floor of Endeavour Crater, which is about 14 miles (22 kilometers) in diameter. Opportunity has been investigating sites on and near the western rim of Endeavour since 2011, following seven years of exploring smaller craters after its 2004 landing. This view merges exposures taken through three of the Pancam's color filters, centered on wavelengths of 753 nanometers (near-infrared), 535 nanometers (green) and 432 nanometers (violet). Color is enhanced in this version to make differences in surface materials more easily visible. The rover team calls this the "Sprained Ankle

  12. Panorama Above 'Perseverance Valley' on Mars

    NASA Image and Video Library

    2017-07-20

    Toward the right side of this enhanced-color scene is a broad notch in the crest of the western rim of Endeavour Crater. Wheel tracks in that area were left by NASA's Mars Exploration Rover Opportunity as it observed "Perseverance Valley" from above in the spring of 2017. The valley is a major destination for the rover's extended mission. It descends out of sight on the inner slope of the rim, extending down and eastward from that notch. Opportunity's panoramic camera (Pancam) took the component images for this view from a position outside the crater during the span of June 7 to June 19, 2017, sols 4753 to 4765 of the rover's work on Mars. This scene includes features that might have been ancient channels from water, ice or wind moving toward the notch in the rim, which might have been a spillway. Perseverance Valley, just on the other side, was likely carved by action of some fluid, such as water, water-lubricated debris, or wind. The mission is investigating to learn more about that process from evidence in place. The panorama spans about three-fourths of a full-circle view, from southeastward on the left, through westward in the middle, to northeastward on the right. High points visible on the rim of Endeavour Crater include "Winnemucca" on the left and "Cape Tribulation" on the right. Winnemucca is part of the "Cape Byron" portion of the crater rim. The horizon at far right extends across the floor of Endeavour Crater, which is about 14 miles (22 kilometers) in diameter. Opportunity has been investigating sites on and near the western rim of Endeavour since 2011, following seven years of exploring smaller craters after its 2004 landing. This view merges exposures taken through three of the Pancam's color filters, centered on wavelengths of 753 nanometers (near-infrared), 535 nanometers (green) and 432 nanometers (violet). Color is enhanced in this version to make differences in surface materials more easily visible. The rover team calls this the "Sprained Ankle

  13. Geophysical studies in the vicinity of Blue Mountain and Pumpernickel Valley near Winnemucca, north-central Nevada

    USGS Publications Warehouse

    Ponce, David A.

    2012-01-01

    From May 2008 to September 2009, the U.S. Geological Survey (USGS) collected data from more than 660 gravity stations, 100 line-km of truck-towed magnetometer traverses, and 260 physical-property sites in the vicinity of Blue Mountain and Pumpernickel Valley, northern Nevada (fig. 1). Gravity, magnetic, and physical-property data were collected to study regional crustal structures as an aid to understanding the geologic framework of the Blue Mountain and Pumpernickel Valley areas, which in general, have implications for mineral- and geothermal-resource investigations throughout the Great Basin.

  14. Primary state formation in the Viru Valley, north coast of Peru.

    PubMed

    Millaire, Jean-François

    2010-04-06

    The origins of urban life and functioning states are two of the most fascinating research problems in anthropological archeology and a topic that has intrigued generations of scholars working on the Peruvian north coast. In this region, Andeanists have documented the rise of Moche as a dominant culture during the first millennium A.D., and the emergence of urban life and stately institutions at this society's principal center. Although there is a broad consensus that Moche represents an archaic state, it is still unclear whether it is an example of primary state formation or a case of a second-generation state. To document this question, archaeological excavations were recently carried out at the Gallinazo Group site in the Virú Valley. Results from a radiocarbon dating program indicate that a functioning state probably emerged in this valley during the second century B.C., possibly preceding Moche by a few centuries. These results necessarily raise question regarding the nature of state development on the north coast of Peru and, in particular, whether there was a single center of state development in this region or multiple sites where similar conditions and processes led to the parallel emergence of functioning states.

  15. 27 CFR 9.154 - Chiles Valley.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Chiles Valley. (a) Name. The name of the viticultural area described in this section is “Chiles Valley... viticultural area are four 1:24,000 Scale U.S.G.S. topography maps. They are titled: (1) St. Helena, CA 1960 photorevised 1980; (2) Rutherford, CA 1951 photorevised 1968; (3) Chiles Valley, CA 1958 photorevised 1980; (4...

  16. High-resolution seismic reflection/refraction imaging from Interstate 10 to Cherry Valley Boulevard, Cherry Valley, Riverside County, California: implications for water resources and earthquake hazards

    USGS Publications Warehouse

    Gandhok, G.; Catchings, R.D.; Goldman, M.R.; Horta, E.; Rymer, M.J.; Martin, P.; Christensen, A.

    1999-01-01

    recharging program based on injection wells. However, at an existing surface recharge site, surface recharge of the aquifer was limited by the presence of clayrich layers that impede the downward percolation of the surface water. In boreholes, these clay-rich layers were found to extend from the near surface to about 50 m depth. If practical, the SGWD desired to relocate the recharge ponds to another location within the Cherry Valley–Beaumont area. This required that sites be found where the clay-rich layers were absent. The SGWD elected to explore for such sites by employing a combination of drilling and seismic techniques. A number of near-surface faults have been suggested in the Cherry Valley-Beaumont area (Figure 1b). However, there may be additional unmapped faults that underlie the alluvial valley of San Gorgonio Pass. Because faults are known to act as barriers to lateral groundwater flow in alluvial groundwater systems, mapped and unmapped subsurface faults in the Cherry Valley-Beaumont area would likely influence groundwater flow and the lateral distribution of recharged water. These same faults may pose a significant hazard to the local desert communities and to greater areas of southern California due to the presence of lifelines (water, electrical, gas, transportation, etc.) that extend through San Gorgonio Pass to larger urban areas. The three principal goals of the seismic investigation presented in this report were to laterally map the subsurface stratigraphic horizons, locate faults that may act as barriers to groundwater flow, and measure velocities of shallow sediments that may give rise to amplified shaking during major earthquakes.

  17. Meter-Scale Characteristics of Martian Channels and Valleys

    USGS Publications Warehouse

    Carr, M.H.; Malin, M.C.

    2000-01-01

    Mars Global Surveyor images, with resolutions as high as 1.5 m pixel, enable characterization of martian channels and valleys at resolutions one to two orders of magnitude better than was previously possible. A major surprise is the near-absence of valleys a few hundred meters wide and narrower. The almost complete absence of fine-scale valleys could be due to lack of precipitation, destruction of small valleys by erosion, or dominance of infiltration over surface runoff. V-shaped valleys with a central channel, such as Nanedi Vallis, provide compelling evidence for sustained or episodic flow of water across the surface. Larger valleys appear to have formed not by headward erosion as a consequence of groundwater sapping but by erosion from water sources upstream of the observed sections. The freshest appearing valleys have triangular cross sections, with talus from opposing walls meeting at the center of the valley. The relations suggest that the width of the valleys is controlled by the depth of incision and the angle of repose of the walls. The flat floors of less fresh-appearing valleys result primarily from later eolian fill. Several discontinuous valleys and lines of craters suggest massive subsurface solution or erosion. The climatic implications of the new images will remain obscure until the cause for the scarcity of fine-scale dissection is better understood. ?? 2000 Academic Press.

  18. Education Outreach Associated with Technology Transfer in a Colonia of South Texas: Green Valley Farms Science and Space Club for Middle School Aged Children in Green Valley Farms, San Benito, Texas

    NASA Technical Reports Server (NTRS)

    Potess, Marla D.; Rainwater, Ken; Muirhead, Dean

    2004-01-01

    Texas colonias are unincorporated subdivisions characterized by inadequate water and wastewater infrastructure, inadequate drainage and road infrastructure, substandard housing, and poverty. Since 1989 the Texas Legislature has implemented policies to halt further development of colonias and to address water and wastewater infrastructure needs in existing and new colonias along the border with Mexico. Government programs and non-government and private organization projects aim to address these infrastructure needs. Texas Tech University's Water Resources Center demonstrated the use of alternative on-site wastewater treatment in the Green Valley Farms colonia, San Benito, Texas. The work in Green Valley Farms was a component of a NASA-funded project entitled Evaluation of NASA's Advanced Life Support Integrated Water Recovery System for Non-Optimal Conditions and Terrestrial Applications. Two households within the colonia are demonstration sites for constructed wetlands. A colonia resident and activist identified educational opportunities for colonia children as a primary goal for many colonia residents. Colonia parents view education as the door to opportunity and escape from poverty for their children. The educational outreach component of the project in Green Valley Farms was a Science and Space Club for middle-school age students. Involved parents, schoolteachers, and school administrators enthusiastically supported the monthly club meetings and activities. Each month, students participated in interactive learning experiences about water use and reuse in space and on earth. Activities increased knowledge and interest in water resource issues and in science and engineering fields. The Institute for the Development and Enrichment of Advanced Learners (IDEAL) at Texas Tech University provided full scholarships for five students from Green Valley Farms to attend the Shake Hands With Your Future camp at Texas Tech University in June 2003. The educational outreach

  19. Recursive stochastic effects in valley hybrid inflation

    NASA Astrophysics Data System (ADS)

    Levasseur, Laurence Perreault; Vennin, Vincent; Brandenberger, Robert

    2013-10-01

    Hybrid inflation is a two-field model where inflation ends because of a tachyonic instability, the duration of which is determined by stochastic effects and has important observational implications. Making use of the recursive approach to the stochastic formalism presented in [L. P. Levasseur, preceding article, Phys. Rev. D 88, 083537 (2013)], these effects are consistently computed. Through an analysis of backreaction, this method is shown to converge in the valley but points toward an (expected) instability in the waterfall. It is further shown that the quasistationarity of the auxiliary field distribution breaks down in the case of a short-lived waterfall. We find that the typical dispersion of the waterfall field at the critical point is then diminished, thus increasing the duration of the waterfall phase and jeopardizing the possibility of a short transition. Finally, we find that stochastic effects worsen the blue tilt of the curvature perturbations by an O(1) factor when compared with the usual slow-roll contribution.

  20. Catchment Dispersion Mechanisms in an Urban Context

    NASA Astrophysics Data System (ADS)

    Gironas, J. A.; Mejia, A.; Rossel, F.; Rinaldo, A.; Rodriguez, F.

    2014-12-01

    Dispersion mechanisms have been examined in-depth in natural catchments in previous studies. However, these dispersion mechanisms have been studied little in urban catchments, where artificial transport elements and morphological arrangements are expected to modify travel times and mobilize excess rainfall from spatially distributed impervious sites. Thus, these features can modify the variance of the catchment's travel times and hence the total dispersion. This work quantifies the dispersion mechanisms in an urban catchment using the theory of transport by travel times as represented by the Urban Morpho-climatic Instantaneous Unit Hydrograph (U-McIUH) model. This model computes travel times based on kinematic wave theory and accounts explicitly for the path heterogeneities and altered connectivity patterns characteristic of an urban drainage network. The analysis is illustrated using the Aubinière urban catchment (France) as a case study. We found that kinematic dispersion is dominant for small rainfall intensities, whereas geomorphologic dispersion becomes more dominant for larger intensities. The total dispersion scales with the drainage area in a power law fashion. The kinematic dispersion is dominant across spatial scales up to a threshold of approximately 2-3 km2, after which the geomorphologic dispersion becomes more dominant. Overall, overland flow is responsible for most of the dispersion, while conduits tend to counteract the increase of the geomorphologic dispersion with a negative kinematic dispersion. Further studies with other catchments are needed to assess whether the latter is a general feature of urban drainage networks.

  1. Raptor ecology of Raft River Valley, Idaho

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Thurow, T.L.; White, C.M.; Howard, R.P.

    1980-09-01

    Raptor data were gathered in the 988-km/sup 2/ Raft River Valley in southcentral Idaho while conducting a tolerance study on the nesting Ferruginous Hawk (Buteo regalis) near the Department of Energy's Raft River Geothermal Site. Prior research from 1972 to 1977 on the nesting activity of the Ferruginous Hawk population provided a historical information base. These data are combined with new Ferruginous Hawk data collected between 1978 and 1980 to give a continuous 9-year breeding survey. Information on the distribution, density, and production of the other raptor species found in the study area during 1978 and 1979 is also provided.

  2. Land subsidence in the San Joaquin Valley, California, as of 1980

    USGS Publications Warehouse

    Ireland, R.L.; Poland, J.F.; Riley, F.S.

    1982-01-01

    Land subsidence due to ground-water overdraft in the San Joaquin Valley began in the mid-1920 's and continued at alarming rates until surface was imported through major canals and aqueducts in the 1950 's and late 1960's. In areas where surface water replaced withdrawal of ground-water, water levels in the confined system rose sharply and subsidence slowed. In the late 1960 's and early 1970 's water levels in wells recovered to levels of the 1940 's and 1950 's throughout most of the western and southern parts of the Valley, in response to the importation of surface water through the California aqueduct. During the 1976-77 drought data collected at water-level and extensometer sites showed the effect of heavy demand on the ground-water resevoir. With the ' water of compaction ' gone, artesian head declined 10 to 20 times as fast as during the first cycle of long-term drawdown that ended in the late 1960's. In the 1978-79 water levels recovered to or above the 1976 pre-drought levels. The report suggests continued monitoring of land subsidence in the San Joaquin Valley. (USGS)

  3. Dynamic deformations of shallow sediments in the Valley of Mexico, Part II: Single-station estimates

    USGS Publications Warehouse

    Singh, S.K.; Santoyo, M.; Bodin, P.; Gomberg, J.

    1997-01-01

    We develop simple relations to estimate dynamic displacement gradients (and hence the strains and rotations) during earthquakes in the lake-bed zone of the Valley of Mexico, where the presence of low-velocity, high-water content clays in the uppermost layers cause dramatic amplification of seismic waves and large strains. The study uses results from a companion article (Bodin et al., 1997) in which the data from an array at Roma, a lake-bed site, were analyzed to obtain displacement gradients. In this article, we find that the deformations at other lake-bed sites may differ from those at Roma by a factor of 2 to 3. More accurate estimates of the dominant components of the deformation at an individual instrumented lake-bed site may be obtained from the maximum horizontal velocity and displacement, ??max and umax, at the surface. The maximum surface strain ??max is related to ??max by ??max = ??max/C, with C ??? 0.6 km/sec. From the analysis of data from sites equipped with surface and borehole sensors, we find that the vertical gradient of peak horizontal displacement (??umax/??z) computed from sensors at 0 and 30 m equals (umax)z = 0/??z, ??z = 30 m, within a factor of 1.5. This is the largest gradient component, and the latter simple relation permits its estimation from surface records alone. The observed profiles of umax versus depth suggest a larger gradient in some depth range of 10 to 20 m, in agreement with synthetic calculations presented in Bodin et al. (1997). From the free-field recordings of the 19 September 1985 Michoacan earthquake, we estimate a maximum surface strain, ??max, between 0.05% and 0.11%, and a lower bound for the peak vertical gradient (??umax/??z) between 0.3% and 1.3%. This implies that (1) the extensive failure of water pipe joints during the Michoacan earthquake in the valley occurred at axial strains of about 0.1%, not 0.38% as previously reported, and (2) the clays of the valley behave almost linearly even at shear strain of about 1

  4. Microscopic Identification of Prokaryotes in Modern and Ancient Halite, Saline Valley and Death Valley, California

    NASA Astrophysics Data System (ADS)

    Schubert, Brian A.; Lowenstein, Tim K.; Timofeeff, Michael N.

    2009-06-01

    Primary fluid inclusions in halite crystallized in Saline Valley, California, in 1980, 2004-2005, and 2007, contain rod- and coccoid-shaped microparticles the same size and morphology as archaea and bacteria living in modern brines. Primary fluid inclusions from a well-dated (0-100,000 years), 90 m long salt core from Badwater Basin, Death Valley, California, also contain microparticles, here interpreted as halophilic and halotolerant prokaryotes. Prokaryotes are distinguished from crystals on the basis of morphology, optical properties (birefringence), and uniformity of size. Electron micrographs of microparticles from filtered modern brine (Saline Valley), dissolved modern halite crystals (Saline Valley), and dissolved ancient halite crystals (Death Valley) support in situ microscopic observations that prokaryotes are present in fluid inclusions in ancient halite. In the Death Valley salt core, prokaryotes in fluid inclusions occur almost exclusively in halite precipitated in perennial saline lakes 10,000 to 35,000 years ago. This suggests that trapping and preservation of prokaryotes in fluid inclusions is influenced by the surface environment in which the halite originally precipitated. In all cases, prokaryotes in fluid inclusions in halite from the Death Valley salt core are miniaturized (<1 μm diameter cocci, <2.5 μm long, very rare rod shapes), which supports interpretations that the prokaryotes are indigenous to the halite and starvation survival may be the normal response of some prokaryotes to entrapment in fluid inclusions for millennia. These results reinforce the view that fluid inclusions in halite and possibly other evaporites are important repositories of microbial life and should be carefully examined in the search for ancient microorganisms on Earth, Mars, and elsewhere in the Solar System.

  5. Valley Vortex States in Sonic Crystals

    NASA Astrophysics Data System (ADS)

    Lu, Jiuyang; Qiu, Chunyin; Ke, Manzhu; Liu, Zhengyou

    2016-03-01

    Valleytronics is quickly emerging as an exciting field in fundamental and applied research. In this Letter, we study the acoustic version of valley states in sonic crystals and reveal a vortex nature of such states. In addition to the selection rules established for exciting valley polarized states, a mimicked valley Hall effect of sound is proposed further. The extraordinary chirality of valley vortex states, detectable in experiments, may open a new possibility in sound manipulations. This is appealing to scalar acoustics that lacks a spin degree of freedom inherently. In addition, the valley selection enables a handy way to create vortex matter in acoustics, in which the vortex chirality can be controlled flexibly. Potential applications can be anticipated with the exotic interaction of acoustic vortices with matter, such as to trigger the rotation of the trapped microparticles without contact.

  6. Adenovirus infection in savanna chimpanzees (Pan troglodytes schweinfurthii) in the Issa Valley, Tanzania.

    PubMed

    Dadáková, Eva; Brožová, Kristýna; Piel, Alex K; Stewart, Fiona A; Modrý, David; Celer, Vladimír; Hrazdilová, Kristýna

    2018-01-01

    Adenoviruses are a widespread cause of diverse human infections with recently confirmed zoonotic roots in African great apes. We focused on savanna-dwelling chimpanzees in the Issa Valley (Tanzania), which differ from those from forested sites in many aspects of behavior and ecology. PCR targeting the DNA polymerase gene detected AdV in 36.7% (69/188) of fecal samples. We detected five groups of strains belonging to the species Human mastadenovirus E and two distinct groups within the species Human mastadenovirus C based on partial hexon sequence. All detected AdVs from the Issa Valley are related to those from nearby Mahale and Gombe National Parks, suggesting chimpanzee movements and pathogen transmission.

  7. Statecraft and expansionary dynamics: A Virú outpost at Huaca Prieta, Chicama Valley, Peru

    PubMed Central

    Millaire, Jean-François; Prieto, Gabriel; Surette, Flannery; Redmond, Elsa M.; Spencer, Charles S.

    2016-01-01

    Interpolity interaction and regional control were central features of all early state societies, taking the form of trade—embedded in political processes to varying degrees—or interregional conquest strategies meant to expand the polity’s control or influence over neighboring territories. Cross-cultural analyses of early statecraft suggest that territorial expansion was an integral part of the process of primary state formation, closely associated with the delegation of authority to subordinate administrators and the construction of core outposts of the state in foreign territories. We report here on a potential case of a core outpost, associated with the early Virú state, at the site of Huaca Prieta in the Chicama Valley, located 75 km north of the Virú state heartland on the north coast of Peru. This site is discussed in the context of other possible Virú outposts in the Moche Valley, Pampa La Cruz, and Huaca Las Estrellas, and as part of a broader reflection on expansionary dynamics and statecraft. PMID:27671633

  8. Statecraft and expansionary dynamics: A Virú outpost at Huaca Prieta, Chicama Valley, Peru.

    PubMed

    Millaire, Jean-François; Prieto, Gabriel; Surette, Flannery; Redmond, Elsa M; Spencer, Charles S

    2016-10-11

    Interpolity interaction and regional control were central features of all early state societies, taking the form of trade-embedded in political processes to varying degrees-or interregional conquest strategies meant to expand the polity's control or influence over neighboring territories. Cross-cultural analyses of early statecraft suggest that territorial expansion was an integral part of the process of primary state formation, closely associated with the delegation of authority to subordinate administrators and the construction of core outposts of the state in foreign territories. We report here on a potential case of a core outpost, associated with the early Virú state, at the site of Huaca Prieta in the Chicama Valley, located 75 km north of the Virú state heartland on the north coast of Peru. This site is discussed in the context of other possible Virú outposts in the Moche Valley, Pampa La Cruz, and Huaca Las Estrellas, and as part of a broader reflection on expansionary dynamics and statecraft.

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

    PubMed

    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.

  10. The Effects of Mountaintop Mines and Valley Fills on Aquatic ...

    EPA Pesticide Factsheets

    This report assesses the state of the science on the environmental impacts of mountaintop mines and valley fills (MTM-VF) on streams in the Central Appalachian Coalfields. Our review focused on the aquatic impacts of mountaintop removal coal mining, which, as its name suggests, involves removing all or some portion of the top of a mountain or ridge to expose and mine one or more coal seams. The excess overburden is disposed of in constructed fills in small valleys or hollows adjacent to the mining site. MTM-VF lead directly to five principal alterations of stream ecosystems: (1) springs, intermittent streams, and small perennial streams are permanently lost with the removal of the mountain and from burial under fill, (2) concentrations of major chemical ions are persistently elevated downstream, (3) degraded water quality reaches levels that are acutely lethal to standard laboratory test organisms, (4) selenium concentrations are elevated, reaching concentrations that have caused toxic effects in fish and birds and (5) macroinvertebrate and fish communities are consistently and significantly degraded. This report assesses the state of the science on the environmental impacts of Mountaintop Mines and Valley Fills (MTM-VF) on streams in the Central Appalachian Coalfields. The draft report will be externally peer reviewed by EPA's Science Advisory Board in early 2010.

  11. Seasonal Growth Patterns of Blue and Valley Oak Seedlings Established on Foothill Rangelands

    Treesearch

    Douglas D. McCreary

    1991-01-01

    Blue (Quercus douglasii Hook. & Am.) and valley (Quercus lobata Née) oak seedlings were planted on a foothill rangeland site in 1987 and 1988. Both species were watered their first year but received no irrigation thereafter. They were evaluated during each subsequent spring and summer for survival, weekly height growth and...

  12. Surface texture analysis of southern Tuli Basin sediments: Implications for Limpopo Valley geoarchaeological contexts

    NASA Astrophysics Data System (ADS)

    Le Baron, Joel C.; Grab, Stefan W.; Kuman, Kathleen

    2011-03-01

    The Hackthorne 1 site (southern Tuli Basin, South Africa) is situated on a sand-covered plateau adjacent to the Limpopo River Valley. Although the site is well known for its Stone Age archaeology, the past environmental contexts (particularly sedimentological/geomorphological) are not well known. We examine the Hackthorne sand grain surface textures, so as to provide some insight on the site specific and regional depositional history. Quartz sands at Hackthorne were collected from surface sands and from underlying weathered calcrete. SEM analysis was performed on sand grains, through which several mechanical and chemical microtextures were identified. Microtextures typical of fluvial environments were found only on grains derived from the plateau calcrete host sediment, whilst the surface sands exhibited only textures associated with aeolian environments. The results indicate that the calcrete host sediment is composed of alluvium, and that the surface sands mantling the Hackthorne Plateau are not deflated from the alluvial deposits in the Limpopo Valley, but may rather be derived from distant aeolian sources. The deposition of aeolian sands is consistent with OSL dates which place sand deposition, or remobilization, at 23 and 15 kya, periods in southern Africa associated with increased aridity.

  13. Wetland survey of the X-10 Bethel Valley and Melton Valley groundwater operable units at Oak Ridge National Labortory Oak Ridge, Tennessee

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rosensteel, B.A.

    1996-03-01

    Executive Order 11990, Protection of Wetlands, (May 24, 1977) requires that federal agencies avoid, to the extent possible, adverse impacts associated with the destruction and modification of wetlands and that they avoid direct and indirect support of wetlands development when there is a practicable alternative. In accordance with Department of Energy (DOE) Regulations for Compliance with Floodplains and Wetlands Environmental Review Requirements (Subpart B, 10 CFR 1022.11), surveys for wetland presence or absence were conducted in both the Melton Valley and the Bethel Valley Groundwater Operable Units (GWOU) on the DOE Oak Ridge Reservation (ORR) from October 1994 through Septembermore » 1995. As required by the Energy and Water Development Appropriations Act of 1992, wetlands were identified using the criteria and methods set forth in the Wetlands Delineation Manual (Army Corps of Engineers, 1987). Wetlands were identified during field surveys that examined and documented vegetation, soils, and hydrologic evidence. Most of the wetland boundary locations and wetland sizes are approximate. Boundaries of wetlands in Waste Area Grouping (WAG) 2 and on the former proposed site of the Advanced Neutron Source in the upper Melton Branch watershed were located by civil survey during previous wetland surveys; thus, the boundary locations and areal sizes in these areas are accurate. The wetlands were classified according to the system developed by Cowardin et al. (1979) for wetland and deepwater habitats of the United States. A total of 215 individual wetland areas ranging in size from 0.002 ha to 9.97 ha were identified in the Bethel Valley and Melton Valley GWOUs. The wetlands are classified as palustrine forested broad-leaved deciduous (PFO1), palustrine scrub-shrub broad-leaved deciduous (PSS1), and palustrine persistent emergent (PEM1).« less

  14. Optical tuning of electronic valleys (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Sie, Edbert J.; Gedik, Nuh

    2017-02-01

    Monolayer transition-metal dichalcogenides such as MoS2 and WS2 are prime examples of atomically thin semiconducting crystals that exhibit remarkable electronic and optical properties. They have a pair of valleys that can serve as a new electronic degree of freedom, and these valleys obey optical selection rules with circularly polarized light. Here, we discuss how ultrafast laser pulses can be used to tune their energy levels in a controllable valley-selective manner. The energy tunability is extremely large, comparable to what would be obtained using a hundred Tesla of magnetic field. We will also show that such valley tunability can be performed while we effectively manipulate the valley selection rules. Finally, we will explore the prospect of using this technique through photoemission spectroscopy to create a new phase of matter called a valley Floquet topological insulator.

  15. Investigation of Water Quality and Aquatic-Community Structure in Village and Valley Creeks, City of Birmingham, Jefferson County, Alabama 2000-01

    NASA Astrophysics Data System (ADS)

    McPherson, A. K.

    2002-12-01

    The U.S. Geological Survey conducted a 16-month investigation of water quality, aquatic-community structure, bed sediment, and fish tissue in Village and Valley Creeks, two urban streams that drain areas of residential, commercial, and industrial land use in Birmingham, Alabama. Water-quality data were collected between February 2000 and March 2001 at four sites on Village Creek, three sites on Valley Creek, and at two reference sites near Birmingham, Fivemile Creek and Little Cahaba River, that drain less urbanized areas. The occurrence and distribution of chemical constituents in the water column and bed sediment provided an initial assessment of water quality in the streams. Aquatic-community structure, physical condition of fish, and analysis of fish tissue provided an indication of the cumulative effects of the water quality on the aquatic biota. Degraded water quality was seen at the more urbanized sites on Village and Valley Creeks. Elevated concentrations of nutrients, bacteria, trace elements, and organic contaminants were detected in the water column. Trace-element priority pollutants, pesticides, and other organic compounds were detected in higher concentrations in bed sediment and fish tissue at the Village and Valley Creek sites than at the reference site. The richness and density of the fish and benthic-invertebrate communities indicate that the integrity of the aquatic communities in Village and Valley Creeks is poor in comparison to that observed at the two reference sites. Correlations between land use and aquatic-community structure, water quality, bed sediment, and fish tissue were observed. The abundance of mayflies and the number of EPT (ephemeroptera, plecoptera, tricoptera) taxa were negatively correlated with industrial land use. The abundance of midges (an indicator of poor water quality) was positively correlated with industrial land use; the percentage of mosquitofishes (a tolerant species) was positively correlated with commercial land

  16. Martian oceans, valleys and climate

    USGS Publications Warehouse

    Carr, M.H.

    2000-01-01

    The new Mars Global Surveyor altimetry shows that the heavily cratered southern hemisphere of Mars is 5 km higher that the sparely cratered plains of the northern hemisphere. Previous suggestions that oceans formerly occupied that northern plains as evidenced by shorelines are partly supported by the new data. A previously identified outer boundary has a wide range of elevations and is unlikely to be a shoreline but an inner contact with a narrow range of elevations is a more likely candidate. No shorelines are visible in the newly acquired, 2.5 metre/pixel imaging. Newly imaged valleys provide strong support for sustained or episodic flow of water across the Martian surface. A major surprise, however, is the near absence of valleys less than 100 m across. Martian valleys seemingly do not divide into ever smaller valleys as terrestrial valleys commonly do. This could be due to lack of precipitation or lack of surface runoff because of high infiltration rates. High erosion rates and supports warm climates and presence of large bodies of water during heavy bombardment. The climate history and fate of the water after heavy bombardment remain cotroversial.

  17. Estimating soil matric potential in Owens Valley, California

    USGS Publications Warehouse

    Sorenson, Stephen K.; Miller, R.F.; Welch, M.R.; Groeneveld, D.P.; Branson, F.A.

    1988-01-01

    Much of the floor of the Owens Valley, California, is covered with alkaline scrub and alkaline meadow plant communities, whose existence is dependent partly on precipitation and partly on water infiltrated into the rooting zone from the shallow water table. The extent to which these plant communities are capable of adapting to and surviving fluctuations in the water table depends on physiological adaptations of the plants and on the water content, matric potential characteristics of the soils. Two methods were used to estimate soil matric potential in test sites in Owens Valley. The first was the filter-paper method, which uses water content of filter papers equilibrated to water content of soil samples taken with a hand auger. The other method of estimating soil matric potential was a modeling approach based on data from this and previous investigations. These data indicate that the base 10 logarithm of soil matric potential is a linear function of gravimetric soil water content for a particular soil. Estimates of soil water characteristic curves were made at two sites by averaging the gravimetric soil water content and soil matric potential values from multiple samples at 0.1 m depths derived by using the hand auger and filter paper method and entering these values in the soil water model. The characteristic curves then were used to estimate soil matric potential from estimates of volumetric soil water content derived from neutron-probe readings. Evaluation of the modeling technique at two study sites indicated that estimates of soil matric potential within 0.5 pF units of the soil matric potential value derived by using the filter paper method could be obtained 90 to 95% of the time in soils where water content was less than field capacity. The greatest errors occurred at depths where there was a distinct transition between soils of different textures. (Lantz-PTT)

  18. Specters of Waste in India's "Silicon Valley": The Underside of Bangalore's Hi-Tech Economy

    ERIC Educational Resources Information Center

    Narayanareddy, Rajyashree

    2011-01-01

    The southern Indian city of Bangalore is extolled as India's "Silicon Valley," emerging over the past decade as a premier site for capital flows into India's Information Technology (IT) sector. In the dominant narrative of globalization Bangalore is lauded as an aspiring "global city" that attracts sizeable quantities of…

  19. Knickpoints and Hanging Valleys of Licus Vallis, Mars

    NASA Astrophysics Data System (ADS)

    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

  20. Analysis of a commercial small unmanned airborne system (sUAS) in support of the Radiometric Calibration Test Site (RadCaTS) at Railroad Valley

    NASA Astrophysics Data System (ADS)

    Czapla-Myers, Jeffrey S.; Anderson, Nikolaus J.

    2017-09-01

    The Radiometric Calibration Test Site (RadCaTS) is an automated facility developed by the Remote Sensing Group (RSG) at the University of Arizona to provide radiometric calibration data for airborne and satellite sensors. RadCaTS uses stationary ground-viewing radiometers (GVRs) to spatially sample the surface reflectance of the site. The number and location of the GVRs is based on previous spatial, spectral, and temporal analyses of Railroad Valley. With the increase in high-resolution satellite sensors, there is renewed interest in examining the spatial uniformity the 1-km2 RadCaTS area at scales smaller than a typical 30-m sensor. RadCaTS is one of the four instrumented sites currently in the CEOS WGCV Radiometric Calibration Network (RadCalNet), which aims to harmonize the post-launch radiometric calibration of satellite sensors through the use of a global network of automated calibration sites. A better understanding of the RadCaTS spatial uniformity as a function of pixel size will also benefit the RadCalNet work. RSG has recently acquired a commercially-available small unmanned airborne system (sUAS) system, with which preliminary spatial homogeneity measurements of the 1-km2 RadCaTS area were made. This work describes an initial assessment of the airborne platform and integrated camera for spatial studies of RadCaTS using data that were collected in 2016 and 2017.

  1. Trench Logs and Scarp Data from an Investigation of the Steens Fault Zone, Bog Hot Valley and Pueblo Valley, Humboldt County, Nevada

    USGS Publications Warehouse

    Personius, Stephen F.; Crone, Anthony J.; Machette, Michael N.; Kyung, Jai Bok; Cisneros, Hector; Lidke, David J.; Mahan, Shannon

    2006-01-01

    Introduction: This report contains field and laboratory data from a study of the Steens fault zone near Denio, Nev. The 200-km-long Steens fault zone forms the longest, most topographically prominent fault-bounded escarpment in the Basin and Range of southern Oregon and northern Nevada. The down-to-the-east normal fault is marked by Holocene fault scarps along nearly half its length, including the southern one-third of the fault from the vicinity of Pueblo Mountain in southern Oregon to the southern margin of Bog Hot Valley (BHV) southwest of Denio, Nev. We studied this section of the fault to better constrain late Quaternary slip rates, which we hope to compare to deformation rates derived from a recently established geodetic network in the region (Hammond and Thatcher, 2005). We excavated a trench in May 2003 across one of a series of right-stepping fault scarps that extend south from the southern end of the Pueblo Mountains and traverse the floor of Bog Hot Valley, about 4 km south of Nevada State Highway 140. This site was chosen because of the presence of well-preserved fault scarps, their development on lacustrine deposits thought to be suitable for luminescence dating, and the proximity of two geodetic stations that straddle the fault zone. We excavated a second trench in the southern BHV, but the fault zone in this trench collapsed during excavation and thus no information about fault history was documented from this site. We also excavated a soil pit on a lacustrine barrier bar in the southern Pueblo Valley (PV) to better constrain the age of lacustrine deposits exposed in the trench. The purpose of this report is to present photomosaics and trench logs, scarp profiles and slip data, soils data, luminescence and radiocarbon ages, and unit descriptions obtained during this investigation. We do not attempt to use the data presented herein to construct a paleoseismic history of this part of the Steens fault zone; that history will be the subject of a future

  2. Roles of survival and dispersal in reintroduction success of Griffon vulture (Gyps fulvus).

    PubMed

    Le Gouar, Pascaline; Robert, Alexandre; Choisy, Jean-Pierre; Henriquet, Sylvain; Lecuyer, Philippe; Tessier, Christian; Sarrazin, François

    2008-06-01

    The success of reintroduction programs greatly depends on the amount of mortality and dispersal of the released individuals. Although local environmental pressures are likely to play an important role in these processes, they have rarely been investigated because of the lack of spatial replicates of reintroduction. In the present study, we analyzed a 25-year data set encompassing 272 individuals released in five reintroduction programs of Griffon Vultures (Gyps fulvus) in France to examine the respective roles of survival and dispersal in program successes and failures. We use recent developments in multi-strata capture-recapture models to take into account tag loss in survival estimates and to consider and estimate dispersal among release areas. We also examined the effects of sex, age, time, area, and release status on survival, and we tested whether dispersal patterns among release areas were consistent with habitat selection theories. Results indicated that the survival of released adults was reduced during the first year after release, with no difference between sexes. Taking into account local observations only, we found that early survival rates varied across sites. However when we distinguished dispersal from mortality, early survival rates became equal across release sites. It thus appears that among reintroduction programs difference in failure and success was due to differential dispersal among release sites. We revealed asymmetrical patterns of dispersal due to conspecific attraction: dispersers selected the closest and the largest population. We showed that mortality can be homogeneous from one program to another while, on the contrary, dispersal is highly dependent on the matrix of established populations. Dispersal behavior is thus of major interest for metapopulation restoration and should be taken into account in planning reintroduction designs.

  3. Ground-water quality and geochemistry in Carson and Eagle Valleys, western Nevada and eastern California

    USGS Publications Warehouse

    Welch, Alan H.

    1994-01-01

    Aquifers in Carson and Eagle Valleys are an important source of water for human consumption and agriculture. Concentrations of major constituents in water from the principal aquifers on the west sides of Carson and Eagle Valleys appear to be a result of natural geochemical reactions with minerals derived primarily from plutonic rocks. In general, water from principal aquifers is acceptable for drinking when compared with current (1993) Nevada State drinking-water maximum contaminant level standards. Water was collected and analyzed for all inorganic constituents for which primary or secondary drinking-water standards have been established. About 3 percent of these sites had con- stituents that exceeded one or more primary or secondary drinking-water standards have been established. About 3 percent of these sites had con- stituents that exceeded one or more primary standards and water at about 10 percent of the sites had at least one constituent that surpassed a secondary standard. Arsenic exceeded the standard in water at less than 1 percent of the principal aquifer sites; nitrate surpassed its standard in water at 3 percent of 93 sites. Water from wells in the principal aquifer with high concentrations of nitrate was in areas where septic systems are used; these concentrations indicate that contamination may be entering the wells. Concentrations of naturally occurring radionuclides in water from the principal aquifers, exceed the proposed Federal standards for some constituents, but were not found t be above current (1993) State standards. The uranium concen- trations exceeded the proposed 20 micrograms per liter Federal standard at 10 percent of the sites. Of the sites analyzed for all of the inorganic constituents with primary standards plus uranium, 15 percent exceed one or more established standards. If the proposed 20 micrograms per liter standard for uranium is applied to the sampled sites, then 23 percent would exceed the standard for uranium or some other

  4. Bioindicators from Mosquitofish (Gambusia affinis) Sampled from the Imperial Valley in Southern California

    USGS Publications Warehouse

    Jenkins, Jill A.; Draugelis-Dale, Rassa O.

    2006-01-01

    The Sonny Bono Salton Sea National Wildlife Refuge (SSNWR) is located 64 km north of the Mexican border at the southern end of the Salton Sea in California's Imperial Valley. Freshwater ponds and managed habitats at the SSNWR, Calipatria, Calif. are supplied with Colorado River water that carries compounds from upstream sources. Components include municipal and industrial discharges, agricultural drainage, and sewage plant inputs. Aquatic animals in these ecosystems are continuously exposed to multiple constituents, several of which have been demonstrated to be associated with hormonal disturbances. We investigated possible endocrine impacts to fish in the Imperial Valley, Calif., by addressing the null hypothesis that aquatic species in impacted sites did not exhibit evidence of endocrine disruption as compared with those from nonimpacted sites. The results presented are intended to provide managers with science-based information and interpretations about the condition of the animals in their ecosystems for the minimization of potential adverse effects to trust fish and wildlife resources and for the maximization of available water resources.

  5. Magnetic control of valley pseudospin in monolayer WSe 2

    DOE PAGES

    Aivazian, G.; Gong, Zhirui; Jones, Aaron M.; ...

    2015-01-26

    Local energy extrema of the bands in momentum space, or valleys, can endow electrons in solids with pseudo-spin in addition to real spin 1-5. In transition metal dichalcogenides this valley pseudo-spin, like real spin, is associated with a magnetic moment1,6 which underlies the valley-dependent circular dichroism 6 that allows optical generation of valley polarization 7-9, intervalley quantum coherence 10, and the valley Hall effect 11. However, magnetic manipulation of valley pseudospin via this magnetic moment 12-13, analogous to what is possible with real spin, has not been shown before. Here we report observation of the valley Zeeman splitting and magneticmore » tuning of polarization and coherence of the excitonic valley pseudospin, by performing polarization-resolved magneto-photoluminescence on monolayer WSe 2. Our measurements reveal both the atomic orbital and lattice contributions to the valley orbital magnetic moment; demonstrate the deviation of the band edges in the valleys from an exact massive Dirac fermion model; and reveal a striking difference between the magnetic responses of neutral and charged valley excitons which is explained by renormalization of the excitonic spectrum due to strong exchange interactions.« less

  6. Spin and valley filter across line defect in silicene

    NASA Astrophysics Data System (ADS)

    Wang, Sake; Ren, Chongdan; Li, Yunfang; Tian, Hongyu; Lu, Weitao; Sun, Minglei

    2018-05-01

    We propose a new scheme to achieve an effective spin/valley filter in silicene with extended line defect on the basis of spin–valley coupling due to the intrinsic spin-orbit coupling (SOC). The transmission coefficient of the spin/valley states is seriously affected by the SOC. When a perpendicular magnetic field is applied on one side of the line defect, one valley state will experience backscattering, but the other valley will not; this leads to high valley polarization in all transmission directions. Moreover, the spin/valley polarization can be enhanced to 96% with the aid of a perpendicular electric field.

  7. Debris Flow Process and Climate Controls on Steepland Valley Form and Evolution

    NASA Astrophysics Data System (ADS)

    Struble, W.; Roering, J. J.

    2017-12-01

    In unglaciated mountain ranges, steepland bedrock valleys often dominate relief structure and dictate landscape response to perturbations in tectonics or climate; drainage divides have been shown to be dynamic and drainage capture is common. Landscape evolution models often use the stream power model to simulate morphologic changes, but steepland valley networks exhibit trends that deviate from predictions of this model. The prevalence of debris flows in steep channels has motivated approaches that account for commonly observed curvature of slope-area data at small drainage areas. Debris flow deposits correspond with observed curvature in slope-area data, wherein slope increases slowly as drainage area decreases; debris flow incision is implied upstream of deposits. In addition, shallow landslides and in-channel sediment entrainment in humid and arid regions, respectively, have been identified as likely debris flow triggering mechanisms, but the extent to which they set the slope of steep channels is unclear. While an untested model exists for humid landscape debris flows, field observations and models are lacking for regions with lower mean annual precipitation. The Oregon Coastal Ranges are an ideal humid setting for observing how shallow landslide-initiated debris flows abrade channel beds and/or drive exposure-driven weathering. Preliminary field observations in the Lost River Range and the eastern Sierra Nevada - semi-arid and unglaciated environments - suggest that debris flows are pervasive in steep reaches. Evidence for fluvial incision is lacking and the presence of downstream debris flow deposits and a curved morphologic signature in slope-area space suggests stream power models are insufficient for predicting and interpreting landscape dynamics. Investigation of debris flow processes in both humid and arid sites such as these seeks to identify the linkage between sediment transport and the characteristic form of steepland valleys. Bedrock weathering

  8. Dispersal of Engineered Male Aedes aegypti Mosquitoes.

    PubMed

    Winskill, Peter; Carvalho, Danilo O; Capurro, Margareth L; Alphey, Luke; Donnelly, Christl A; McKemey, Andrew R

    2015-11-01

    Aedes aegypti, the principal vector of dengue fever, have been genetically engineered for use in a sterile insect control programme. To improve our understanding of the dispersal ecology of mosquitoes and to inform appropriate release strategies of 'genetically sterile' male Aedes aegypti detailed knowledge of the dispersal ability of the released insects is needed. The dispersal ability of released 'genetically sterile' male Aedes aegypti at a field site in Brazil has been estimated. Dispersal kernels embedded within a generalized linear model framework were used to analyse data collected from three large scale mark release recapture studies. The methodology has been applied to previously published dispersal data to compare the dispersal ability of 'genetically sterile' male Aedes aegypti in contrasting environments. We parameterised dispersal kernels and estimated the mean distance travelled for insects in Brazil: 52.8 m (95% CI: 49.9 m, 56.8 m) and Malaysia: 58.0 m (95% CI: 51.1 m, 71.0 m). Our results provide specific, detailed estimates of the dispersal characteristics of released 'genetically sterile' male Aedes aegypti in the field. The comparative analysis indicates that despite differing environments and recapture rates, key features of the insects' dispersal kernels are conserved across the two studies. The results can be used to inform both risk assessments and release programmes using 'genetically sterile' male Aedes aegypti.

  9. One hour of catastrophic landscape change in the upper Rhine River valley 9400 years ago

    NASA Astrophysics Data System (ADS)

    Clague, John; von Poschinger, Andreas; Calhoun, Nancy

    2017-04-01

    The Flims rockslide, which happened about 9400 years ago in the eastern Swiss Alps, is the largest postglacial terrestrial landslide in Europe. The landslide and the huge secondary mass flow it induced completely changed the floor and lower slopes of the Vorderrhein valley over a distance of several tens of kilometres, probably in one hour or less. The landslide began with the sudden detachment of 10-12 km3 of Jurassic and Cretaceous limestone from the north wall of the Vorderrhein valley. The detached rock mass rapidly fragmented as it accelerated and then struck the Rhein valley floor and the opposing valley wall. Tongues of debris traveled up and down the Vorderrhein. The impact liquefied approximately 1 km3 of valley-fill sediments, mainly fluvial and deltaic gravel and sand. The liquefied sediment moved as a slurry - the Bonaduz gravel - tens of kilometres downvalley from the impact site, carrying huge fragments of rockslide debris that became stranded on the valley floor, forming hills termed 'tumas'. Part of the flow was deflected by a cross-valley barrier and flowed 16 km up the Hinterrhein valley (the main tributary of the Vorderrhein), carrying tumas with it. Bonaduz gravel is >65 m thick and fines upward from massive sandy cobble gravel at its base to silty sand at its top. Sedimentologic and geomorphic evidence indicates that the liquefied sediment was transported as a hyperconcentated flow, possibly above a basal carpet of coarse diamictic sediment that behaved as a debris flow. The large amount of water involved in the Bonaduz flow indicates that at least part of the Flims rockslide entered a former lake in Vorderrhein valley. The rockslide debris impounded the Vorderrhein and formed Lake Ilanz, which persisted for decades or longer before the dam was breached in series of outburst floods. These floods further changed the valley floor below the downstream limit of the landslide. Today, Vorderrhein flows in a spectacular 8-km-long gorge incised up to

  10. Hydrologic and geologic characteristics of the Yucca Mountain site relevant to the performance of a potential repository: Day 1, Las Vegas, Nevada to Pahrump, Nevada: Stop 6A. Keane Wonder Spring and regional groundwater flow in the Death Valley region

    USGS Publications Warehouse

    Steinkampf, W.C.

    2000-01-01

    Yucca Mountain, located ~100 mi northwest of Las Vegas, Nevada, has been designated by Congress as a site to be characterized for a potential mined geologic repository for high-level radioactive waste. This field trip will examine the regional geologic and hydrologic setting for Yucca Mountain, as well as specific results of the site characterization program, The first day focuses on the regional seeing with emphasis on current and paleo hydrology, which are both of critical concern for predicting future performance of a potential repository. Morning stops will be in southern Nevada and afternoon stops will be in Death Valley. The second day will be spent at Yucca Mountain. The filed trip will visit the underground testing sites in the "Exploratory Studies Facility" and the "Busted Butte Unsaturated Zone Transport Field Test" plus several surface-based testing sites. Much of the work at the site has concentrated on studies of the unsaturated zone, and element of the hydrologic system that historically has received little attention. Discussions during the second day will comprise selected topics of Yucca Mountain geology, mic hazard in the Yucca Mountain area. Evening discussions will address modeling of regional groundwater flow, the geology and hydrology of Yucca Mountain to the performance of a potential repository. Day 3 will examine the geologic framework and hydrology of the Pahute Mesa-Oasis Valley Groundwater Basin and then will continue to Reno via Hawthorne, Nevada and the Walker Lake area.

  11. Water-quality assessment of the Rio Grande Valley, Colorado, New Mexico, and Texas; summary and analysis of water-quality data for the basic-fixed-site network, 1993-95

    USGS Publications Warehouse

    Healy, D.F.

    1997-01-01

    The Rio Grande Valley study unit of the U.S. Geological Survey National Water-Quality Assessment Program collected monthly water- quality samples at a network of surface-water sites from April 1993 through September 1995. This basic-fixed-site network consisted of nine main-stem sites on the Rio Grande, five sites on tributaries of the Rio Grande, two sites on streams in the Rio Grande Valley study unit that are not directly tributary to the Rio Grande, and one site on a conveyance channel. During each monthly sampling, field properties were measured and samples were collected for the analysis of dissolved solids, major constituents, nutrients, selected trace elements, and suspended-sediment concentrations. During selected samplings, supplemental samples were collected for the analysis of additional trace elements, organic carbon, and/or pesticides. Spatial variations of dissolved-solids, major-constituent, and nutrient data were analyzed. The report presents summary statistics for the monthly water-quality data by sampling site and background information on the drainage basin upstream from each site. Regression equations are presented that relate dissolved-solids, major-constituent, and nutrient concentrations to streamflow, selected field properties, and time. Median instantaneous streamflow at each basic-fixed site ranged from 1.4 to 1,380 cubic feet per second. Median specific conductance at each basic-fixed site ranged from 84 to 1,680 microsiemens per centimeter at 25 degrees Celsius, and median pH values ranged from 7.8 to 8.5. The water sampled at the basic-fixed sites generally was well oxygenated and had a median dissolved-oxygen percent of saturation range from 89 to 108. With the exception of Rio Grande above mouth of Trinchera Creek, near Lasauses, Colorado, dissolved-solids concentrations in the main stem of the Rio Grande generally increased in a downstream direction. This increase is from natural sources such as ground-water inflow and

  12. Validation of EO-1 Hyperion and Advanced Land Imager Using the Radiometric Calibration Test Site at Railroad Valley, Nevada

    NASA Technical Reports Server (NTRS)

    Czapla-Myers, Jeffrey; Ong, Lawrence; Thome, Kurtis; McCorkel, Joel

    2015-01-01

    The Earth-Observing One (EO-1) satellite was launched in 2000. Radiometric calibration of Hyperion and the Advanced Land Imager (ALI) has been performed throughout the mission lifetime using various techniques that include ground-based vicarious calibration, pseudo-invariant calibration sites, and also the moon. The EO-1 mission is nearing its useful lifetime, and this work seeks to validate the radiometric calibration of Hyperion and ALI from 2013 until the satellite is decommissioned. Hyperion and ALI have been routinely collecting data at the automated Radiometric Calibration Test Site [RadCaTS/Railroad Valley (RRV)] since launch. In support of this study, the frequency of the acquisitions at RadCaTS has been significantly increased since 2013, which provides an opportunity to analyze the radiometric stability and accuracy during the final stages of the EO-1 mission. The analysis of Hyperion and ALI is performed using a suite of ground instrumentation that measures the atmosphere and surface throughout the day. The final product is an estimate of the top-of-atmosphere (TOA) spectral radiance, which is compared to Hyperion and ALI radiances. The results show that Hyperion agrees with the RadCaTS predictions to within 5% in the visible and near-infrared (VNIR) and to within 10% in the shortwave infrared (SWIR). The 2013-2014 ALI results show agreement to within 6% in the VNIR and 7.5% in the SWIR bands. A cross comparison between ALI and the Operational Land Imager (OLI) using RadCaTS as a transfer source shows agreement of 3%-6% during the period of 2013-2014.

  13. Revisiting Pearson's climate and forest type studies on the Fort Valley Experimental Forest

    Treesearch

    Joseph E. Crouse; Margaret M. Moore; Peter Fule

    2008-01-01

    Five weather station sites were established in 1916 by Fort Valley personnel along an elevational gradient from the Experimental Station to near the top of the San Francisco Peaks to investigate the factors that controlled and limited forest types. The stations were located in the ponderosa pine, Douglas-fir, limber pine, Engelmann spruce, and Engelmann spruce/...

  14. Use of Optical and Imaging Techniques for Inspection of Off-Line Joule-Heated Melter at the West Valley Demonstration Project

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Plodinec, M. J.; Jang, P-R; Long, Z.

    2003-02-25

    The West Valley melter has been taken out of service. Its design is the direct ancestor of the current melter design for the Hanford Waste Treatment Plant. Over its eight years of service, the West Valley melter has endured many of the same challenges that the Hanford melter will encounter with feeds that are similar to many of the Hanford double shell tank wastes. Thus, inspection of the West Valley melter prior to its disposal could provide valuable--even crucial--information to the designers of the melters to be used at the Hanford Site, particularly if quantitative information can be obtained. Themore » objective of Mississippi State University's Diagnostic Instrumentation and Analysis Laboratory's (DIAL) efforts is to develop, fabricate, and deploy inspection tools for the West Valley melter that will (i) be remotely operable in the West Valley process cell; (ii) provide quantitative information on melter refractory wear and deposits on the refractory; and (iii) indicate areas of heterogeneity (e.g., deposits) requiring more detailed characterization. A collaborative arrangement has been established with the West Valley Demonstration Project (WVDP) to inspect their melter.« less

  15. 27 CFR 9.36 - McDowell Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ....” (b) Approved maps. The appropriate map for determining the boundaries of the McDowell Valley... and the ridge line (highest elevation line) between the McDowell Creek Valley and the Dooley Creek Valley. (3) Then southeasterly along the ridge line (highest elevation line) to the intersection of the...

  16. 27 CFR 9.36 - McDowell Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ....” (b) Approved maps. The appropriate map for determining the boundaries of the McDowell Valley... and the ridge line (highest elevation line) between the McDowell Creek Valley and the Dooley Creek Valley. (3) Then southeasterly along the ridge line (highest elevation line) to the intersection of the...

  17. Evaluation of proposed precipitation mechanisms for Mississippi Valley-type deposits

    USGS Publications Warehouse

    Spirakis, C.S.; Heyl, A.V.

    1996-01-01

    The mechanism of precipitation is an important aspect of any genetic model for Mississippi Valley-type deposits. Yet most of the precipitation mechanisms for minerals in the Mississippi Valley-type association have serious flaws. Solution mixing would require an unlikely series of solutions to account for the various minerals in the ores, and it does not account for the universal occurrence of organic matter in the ores nor for the oxidation state of sulfur in pyrite in the ores. Sulfate reduction addresses some of these problems, but is inconsistent with kinetic data and could not be reversed to account for the oscillations between precipitation and dissolution of sulfide minerals in the ores. Carbon dioxide effervescence does not address the precipitation of most minerals in the ores, and all of the evidence for effervescence may be explained in other ways. Cooling of the mineralizing solution could precipitate many minerals, but fluid inclusion data suggest that, in many deposits, the solution did not cool significantly as any particular stage formed. A credible genetic model also must explain why all of the minerals precipitated at the same sites; any combination of the above mechanisms which suggests that unrelated mechanisms occurred at the same sites by coincidence is unlikely. The most reasonable scenario is that a hot, thiosulfate-bearing mineralizing solution reacted in various ways with organic matter at the sites of mineralization to precipitate the ore minerals. The organic matter acted as a reductant, source of carbon dioxide, source of organic acids, and a substrate for bacterial metabolism of thiosulfate in various stages of mineralization. Thus organic matter links all stages of the mineralization to the same sites. ?? 1995 Elsevier Science B.V.

  18. Using Acceleration Records as Diffuse Fields for Tomography of the Valley of Mexico City: Synthetic Results

    NASA Astrophysics Data System (ADS)

    Baena, M.; Perton, M.; Molina-Villegas, J. C.; Sanchez-Sesma, F. J.

    2013-12-01

    In order to improve the understanding of the seismic response of Mexico City Valley, we have proposed to perform a tomography study of the seismic wave velocities. For that purpose, we used a collection of acceleration seismograms (corresponding to earthquakes with magnitudes ranging from 4.5 to 8.1 and various epicentral distances to the City) recorded since 1985 in 83 stations distributed across the Valley. The H/V spectral ratios (obtained from average autocorrelations) strongly suggest these movements belong to a 3D generalized diffuse field. Thus, we interpret that cross-correlations between the signals of station pairs are proportional to the imaginary part of the corresponding Green function. Finally, the dispersion curves are constructed from the Green function which lead to the tomography. Other tomographies have already been made around the world using either the seismic coda or seismic noise. We used instead the ensemble of many earthquakes from distant sources that have undergone multiple scattering by the heterogeneities of the Earth and assume the wave fields are equipartitioned. The purpose of the present study is to describe the different steps of the data processing by using synthetic models. The wave propagation within an alluvial basin is simulated using the Indirect Boundary Element Method (IBEM) in 2D configuration for the propagation of P and SV waves. The theoretical Green function for a station pair is obtained by placing a unit force at one station and a receiver at the other. The valley illumination is composed by incoming waves which are simulated using distant independent sources and several diffractors. Data process is validated by the correct retrieval the theoretical Green function. We present here the in-plane Green function for the P-SV case and show the dispersion curves constructed from the cross-correlations compared with analytic results for a layer over a half-space. ACKNOWLEDGEMENTS. This study is partially supported by AXA

  19. Valley Near Nilus Chaos

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-504, 5 October 2003

    This August 2003 Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a valley near Nilus Chaos, around 25.2oN, 80.3oW. The scene has a uniform albedo, indicating that all of the landforms are probably mantled by fine, bright dust. Dark streaks on the valley walls indicate places where recent dust avalanches have occurred. The ripple-like dune features on the valley floor were formed by wind, but today they are inactive and covered with dust. A few craters, created by impacting debris, have formed on the dunes, again attesting to their inactivity in the modern martian environment. The image covers an area 3 km (1.9 mi) wide; it is illuminated by sunlight from the lower left.

  20. Hydrologic and geochemical monitoring in Long Valley Caldera, Mono County, California, 1985

    USGS Publications Warehouse

    Farrar, C.D.; Sorey, M.L.; Rojstaczer, S.A.; Janik, C.J.; Winnett, T.L.; Clark, M.D.

    1987-01-01

    Hydrologic and geochemical monitoring, to detect changes caused by magmatic and tectonic processes in the Long Valley caldera has continued through 1985. The monitoring included the collection of the following types of data: chemical and isotopic composition of water and gases from springs, wells, and steam vents; temperatures in wells, springs, and steam vents; flow rates of springs and streams; water levels in wells; and barometric pressure and precipitation at several sites. In addition, reservoir temperatures for the geothermal system were estimated from computations based on chemical geothermometers applied to fluid samples from wells and springs. Estimates of thermal water discharged from springs were made on the basis of boron and chloride fluxes in surface waters for selected sites in the Casa Diablo area and along the Mammoth-Hot Creek drainage. These data are presented in tables and graphs. The Long Valley area was relatively quiescent throughout 1985 in terms of geodetic changes and seismic activity. As a consequence , the hydrologic system varied mainly in response to seasonal influences of temperature, atmospheric pressure, and precipitation. However, spring flows near Casa Diablo were influenced by pumping at the geothermal production well field nearby. (Author 's abstract)

  1. 27 CFR 9.194 - San Antonio Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... significance. (b) Approved Maps. The appropriate maps for determining the boundary of the San Antonio Valley...) Hames Valley, California, 1949, photorevised 1978; (2) Tierra Redonda Mountain, California, 1949... southeast corner of section 14, T23S, R9E, on the Hames Valley map; (2) From the beginning point, proceed...

  2. Tunable valley polarization by a gate voltage when an electron tunnels through multiple line defects in graphene.

    PubMed

    Liu, Zhe; Jiang, Liwei; Zheng, Yisong

    2015-02-04

    By means of an appropriate wave function connection condition, we study the electronic structure of a line defect superlattice of graphene with the Dirac equation method. We obtain the analytical dispersion relation, which can simulate well the tight-binding numerical result about the band structure of the superlattice. Then, we generalize this theoretical method to study the electronic transmission through a potential barrier where multiple line defects are periodically patterned. We find that there exists a critical incident angle which restricts the electronic transmission through multiple line defects within a specific incident angle range. The critical angle depends sensitively on the potential barrier height, which can be modulated by a gate voltage. As a result, non-trivial transmissions of K and K' valley electrons are restricted, respectively, in two distinct ranges of the incident angle. Our theoretical result demonstrates that a gate voltage can act as a feasible measure to tune the valley polarization when electrons tunnel through multiple line defects.

  3. Tree-ring growth patterns and climatic signals along a vertical transect of larch sites in the Simplon and Rhône Valleys (Switzerland)

    NASA Astrophysics Data System (ADS)

    Riechelmann, Dana F. C.; Esper, Jan

    2017-04-01

    State-of-the-art millennial long temperature reconstructions from the European Alps integrate wood samples of Larix decidua Mill. from the Lötschental and Simplon regions in Switzerland (Büntgen et al., 2005; 2006). Some of the oldest samples that enable the extension of the time-series back into the first millennium AD are obtained from old buildings in Simplon Village, through the precise location of these samples and the elevation of sampling sites remain unknown. We here evaluate the growth characteristics of larch tree-ring width data along a vertical transect in the Simplon and Rhône valleys. 330 trees from nine sites in 985, 1100, 1400, 1575, 1710, 1712, 1900, 2020, and 2150 m asl have been sampled and analysed for their climate signals. The results indicate a stronger temperature signal in the tree-ring width with increasing elevation. The lower the sites the more a drought signal is imprinted in the ring width data. The intermediate site at 1400 m asl does not show any pronounced climate signal. A comparison of growth patterns of living-tree sites with samples from the historical buildings in Simplon Village (Riechelmann et al., 2013) indicates the construction timber to origin from intermediate to higher elevations. We therefore do not expect strong temperature signal from these timbers. References: Büntgen, U., Esper, J., Frank, D.C., Nicolussi, K., Schmidhalter, M., 2005. A 1052-year tree-ring proxy for Alpine summer temperatures. Climate Dynamics 25: 141-153. Büntgen, U., Frank, D.C., Nievergelt, D., Esper J., 2006. Summer temperature variations in the European Alps, A.D. 755-2004. Journal of Climate 19: 5606-5623. Riechelmann, D.F.C., Schmidhalter, M., Büntgen, U., Esper, J., 2013. Extending a high-elevation larch ring width chronology from the Simplon region in the Swiss Alps over the past millenium. TRACE 11:103-108.

  4. Audiomagnetotelluric investigation of Snake Valley, eastern Nevada and western Utah

    USGS Publications Warehouse

    McPhee, Darcy K.; Pari, Keith; Baird, Frank

    2009-01-01

    As support for an exploratory well-drilling and hydraulic-testing program, AMT data were collected using a Geometrics Stratagem EH4 system along four profiles that extend roughly east-west from the southern Snake Range into Snake Valley. The profiles range from 3 to 5 kilometers in length, and station spacing was 200 to 400 meters. Two-dimensional inverse models were computed using the data from the transverse-electric (TE), transverse-magnetic (TM), and combined (TE+TM) mode using a conjugate gradient, finite-difference method. Interpretation of the 2-D AMT models defines several faults, some of which may influence ground-water flow in the basins, as well as identify underlying Paleozoic carbonate and clastic rocks and the thickness of basin-fill sediments. These AMT data and models, coupled with the geologic mapping and other surface geophysical methods, form the basis for identifying potential well sites and defining the subsurface structures and stratigraphy within Snake Valley.

  5. Morning Transition Tracer Experiments in a Deep Narrow Valley.

    NASA Astrophysics Data System (ADS)

    Whiteman, C. David

    1989-07-01

    Three sulfur hexafluoride atmospheric tracer experiments were conducted during the post-sunrise temperature inversion breakup period in the deep, narrow Brush Creek Valley of Colorado. Experiments were conducted under clear, undisturbed weather conditions.A continuous elevated tracer plume was produced along the axis of the valley before sunrise and the behavior of the plume during the inversion breakup period was detected down-valley from the release point using an array of radio-controlled sequential bag samplers, a vertical SF6 profiling system carried on a tethered balloon, two portable gas chromatographs operated on a sidewall of the valley, and a continuous real-time SF6 monitor operated from a research aircraft. Supporting meteorological data came primarily from tethered balloon profilers. The nocturnal elevated plume was carried and diffused in down-valley flows. After sunrise, convective boundary layers grew upward from the sunlit valley surfaces, fumigating the elevated plume onto the valley floor and sidewalls. Upslope flow developed in the growing convective boundary layers, carrying fumigated SF6 up the sidewalls and causing a compensating subsidence over the valley center. High post-sunrise SF6 concentrations were experienced on the northeast-facing sidewall of the northwest-southeast oriented valley as a result of cross-valley flow, which developed due to differential solar heating of the sidewalls. Reversal of the down-valley wind system brought air with lower SF6 concentrations into the lower valley.

  6. Mapping the Palaeo-Piniada Valley, Central Greece, Based on Systematic Microtremor Analyses

    NASA Astrophysics Data System (ADS)

    Mantovani, A.; Valkaniotis, S.; Rapti, D.; Caputo, R.

    2018-03-01

    The application of seismic noise-based techniques has become particularly popular in the last decades, as they are not invasive and do not require large teams or expensive equipments. The Horizontal to Vertical Spectral Ratio (HVSR) is commonly used not only in seismic microzoning studies as far as from noise recording constraining the fundamental resonant frequency, but it is also possible to infer the depth of the bedrock knowing the average shear wave velocity of the overlying sedimentary cover, or viceversa (i.e. resonance equation). For the purposes of the present research, more than 300 single-station noise measurements were carried out across the Piniada Valley (Central Greece), along and between several transects planned roughly perpendicular to the mean valley trend. To understand the palaeogeographic and tectonic evolution of this area, we needed an estimation of the geometry at depth of the bedrock underlying the fluvial deposits of the present-day Pinios River. As a result, for each measured site, we calculated the depth of the bedrock and, afterwards, such values were opportunely interpolated for obtaining a 3D model of the palaeo-Piniada Valley documenting for the first time the recent (Late Quaternary) inversion of the topographic gradient.

  7. The Central Valley Hydrologic Model

    NASA Astrophysics Data System (ADS)

    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

  8. 14 CFR 420.21 - Launch site location review-launch site boundary.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Launch site location review-launch site boundary. 420.21 Section 420.21 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION... the debris dispersion radius of the largest launch vehicle type and weight class proposed for the...

  9. 14 CFR 420.21 - Launch site location review-launch site boundary.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Launch site location review-launch site boundary. 420.21 Section 420.21 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION... the debris dispersion radius of the largest launch vehicle type and weight class proposed for the...

  10. 14 CFR 420.21 - Launch site location review-launch site boundary.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Launch site location review-launch site boundary. 420.21 Section 420.21 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION... the debris dispersion radius of the largest launch vehicle type and weight class proposed for the...

  11. 14 CFR 420.21 - Launch site location review-launch site boundary.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Launch site location review-launch site boundary. 420.21 Section 420.21 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION... the debris dispersion radius of the largest launch vehicle type and weight class proposed for the...

  12. 14 CFR 420.21 - Launch site location review-launch site boundary.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Launch site location review-launch site boundary. 420.21 Section 420.21 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION... the debris dispersion radius of the largest launch vehicle type and weight class proposed for the...

  13. NV PFA - Steptoe Valley

    DOE Data Explorer

    Jim Faulds

    2015-10-29

    All datasets and products specific to the Steptoe Valley model area. Includes a packed ArcMap project (.mpk), individually zipped shapefiles, and a file geodatabase for the northern Steptoe Valley area; a GeoSoft Oasis montaj project containing GM-SYS 2D gravity profiles along the trace of our seismic reflection lines; a 3D model in EarthVision; spreadsheet of links to published maps; and spreadsheets of well data.

  14. 27 CFR 9.27 - Lime Kiln Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Lime Kiln Valley. 9.27... OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.27 Lime Kiln Valley. (a) Name. The name of the viticultural area described in this section is “Lime Kiln Valley...

  15. Anthropogenic disturbance reduces seed-dispersal services for myrmecochorous plants in the Brazilian Caatinga.

    PubMed

    Leal, Laura C; Andersen, Alan N; Leal, Inara R

    2014-01-01

    Anthropogenic disturbance can have important indirect effects on ecosystems by disrupting species interactions. Here we examine the effects of anthropogenic disturbance on distance dispersal by ants for the diaspores of myrmecochorous Euphorbiaceae in Brazilian Caatinga. Rates of diaspore removal and distances removed of Croton sonderianus and Jatropha mollissima were observed at 24 sites ranging from low to very high disturbance (primarily grazing by livestock, hunting and firewood collection). Despite a large number of seed-disperser ant species, there were only two species providing high-quality distance-dispersal services, Dinoponera quadriceps (40% of all observed seed removals) and Ectatomma muticum (33%). D. quadriceps was responsible for 97% of all removals >2 m, and 100% of all removals >5 m. Removal rates did not vary with disturbance for C. sonderianus (small elaiosome), but declined with increasing disturbance for J. mollissima (large elaiosome). The number of removals by Ectatomma was highest at intermediate levels of disturbance, whereas those by Dinoponera decreased systematically with increasing levels of disturbance. Mean dispersal distance was four times higher at sites experiencing low disturbance, where removals >5 m represented a third of all removal events, compared with very highly disturbed sites, where no removals >5 m were observed. Despite high overall diversity there is very limited functional redundancy in disperser ant species, resulting in low disperser resilience in relation to disturbance. This is likely to have important implications for recruitment by myrmecochorous plants, and therefore on vegetation composition and structure, at sites subject to high anthropogenic disturbance.

  16. Valley Pearl’ table grape

    USDA-ARS?s Scientific Manuscript database

    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...

  17. Extraction of Martian valley networks from digital topography

    NASA Technical Reports Server (NTRS)

    Stepinski, T. F.; Collier, M. L.

    2004-01-01

    We have developed a novel method for delineating valley networks on Mars. The valleys are inferred from digital topography by an autonomous computer algorithm as drainage networks, instead of being manually mapped from images. Individual drainage basins are precisely defined and reconstructed to restore flow continuity disrupted by craters. Drainage networks are extracted from their underlying basins using the contributing area threshold method. We demonstrate that such drainage networks coincide with mapped valley networks verifying that valley networks are indeed drainage systems. Our procedure is capable of delineating and analyzing valley networks with unparalleled speed and consistency. We have applied this method to 28 Noachian locations on Mars exhibiting prominent valley networks. All extracted networks have a planar morphology similar to that of terrestrial river networks. They are characterized by a drainage density of approx.0.1/km, low in comparison to the drainage density of terrestrial river networks. Slopes of "streams" in Martian valley networks decrease downstream at a slower rate than slopes of streams in terrestrial river networks. This analysis, based on a sizable data set of valley networks, reveals that although valley networks have some features pointing to their origin by precipitation-fed runoff erosion, their quantitative characteristics suggest that precipitation intensity and/or longevity of past pluvial climate were inadequate to develop mature drainage basins on Mars.

  18. Analysis of the effects of meteorology on aircraft exhaust dispersion and deposition using a Lagrangian particle model.

    PubMed

    Pecorari, Eliana; Mantovani, Alice; Franceschini, Chiara; Bassano, Davide; Palmeri, Luca; Rampazzo, Giancarlo

    2016-01-15

    The risk of air quality degradation is of considerable concern particularly for those airports that are located near urban areas. The ability to quantitatively predict the effects of air pollutants originated by airport operations is important for assessing air quality and the related impacts on human health. Current emission regulations have focused on local air quality in the proximity of airports. However, an integrated study should consider the effects of meteorological events, at both regional and local level, that can affect the dispersion and the deposition of exhausts. Rigorous scientific studies and extensive experimental data could contribute to the analysis of the impacts of airports expansion plans. This paper is focused on the analysis of the effects of meteorology on aircraft emission for the Marco Polo Airport in Venice. This is the most important international airport in the eastern part of the Po' Valley, one of the most polluted area in Europe. Air pollution is exacerbated by meteorology that is a combination of large and local scale effects that do not allow significant dispersion. Moreover, the airport is located near Venice, a city of noteworthy cultural and architectural relevance, and nearby the lagoon that hosts several areas of outstanding ecological importance at European level (Natura 2000 sites). Dispersion and deposit of the main aircraft exhausts (NOx, HC and CO) have been evaluated by using a Lagrangian particle model. Spatial and temporal aircraft exhaust dispersion has been analyzed for LTO cycle. Aircraft taxiing resulted to be the most impacting aircraft operation especially for the airport working area and its surroundings, however occasionally peaks may be observed even at high altitudes when cruise mode starts. Mixing height can affect concentrations more significantly than the concentrations in the exhausts themselves. An increase of HC and CO concentrations (15-50%) has been observed during specific meteorological events

  19. Westwards and northwards dispersal of Triosteum himalayanum (Caprifoliaceae) from the Hengduan Mountains region based on chloroplast DNA phylogeography.

    PubMed

    Liu, Hai-Rui; Gao, Qing-Bo; Zhang, Fa-Qi; Khan, Gulzar; Chen, Shi-Long

    2018-01-01

    The varying topography and environment that resulted from paleoorogeny and climate fluctuations of the Himalaya-Hengduan Mountains (HHM) areas had a considerable impact on the evolution of biota during the Quaternary. To understand the phylogeographic pattern and historical dynamics of Triosteum himalayanum (Caprifoliaceae), we sequenced three chloroplast DNA fragments ( rbcL-accD , rps15-ycf1 , and trnH-psbA ) from 238 individuals representing 20 populations. Nineteen haplotypes (H1-H19) were identified based on 23 single-site mutations and eight indels. Most haplotypes were restricted to a single population or neighboring populations. Analysis of molecular variance revealed that variations among populations were much higher than that within populations for the overall gene pool, as well as for the East Himalayan group (EH group) and the North Hengduan group (NHM group), but not for the Hengduan Mountains group (HM group). Ecoregions representing relatively high genetic diversity or high frequencies of private haplotypes were discovered, suggesting that this alpine herbaceous plant underwent enhanced allopatric divergence in isolated and fragmented locations during the Quaternary glaciations. The current phylogeographic structure of T. himalayanum might be due to heterogeneous habitats and Quaternary climatic oscillations. Based on the phylogeographic structure of T. himalayanum populations, the phylogenetic relationship of identified haplotypes and palaeodistributional reconstruction, we postulated both westwards and northwards expansion from the HM group for this species. The westwards dispersal corridor could be long, narrow mountain areas and/or the Yarlung Zangbo Valley, while the northwards movement path could be south-north oriented mountains and low-elevation valleys.

  20. Dynamics of Katabatic Winds in Colorado' Brush Creek Valley.

    NASA Astrophysics Data System (ADS)

    Vergeiner, I.; Dreiseitl, E.; Whiteman, C. David

    1987-01-01

    A method is proposed to evaluate the coupled mass, momentum and thermal energy budget equations for a deep valley under two-dimensional, steady-state flow conditions. The method requires the temperature, down- valley wind and valley width fields to be approximated by simple analytical functions. The vertical velocity field is calculated using the mass continuity equation. Advection terms in the momentum and energy equations are then calculated using finite differences computed on a vertical two-dimensional grid that runs down the valley's axis. The pressure gradient term in the momentum equation is calculated from the temperature field by means of the hydrostatic equation. The friction term is then calculated as a residual in the xmomentum equation, and the diabatic cooling term is calculated as a residual in the thermal energy budget equation.The method is applied to data from an 8-km-long segment of Colorado's; Brush Creek Valley on the night of 30-31 July 1982. Pressure decreased with distance down the peak on horizontal surfaces, with peak horizontal pressure gradients of 0.04 hPa km1. The valley mass budget indicated that subsidence was required in the valley to support calculated mean along-valley mass flux divergence. Peak subsidence rates on the order of 0.10 m s1 were calculated. Subsiding motions in the valley produced negative vertical down-valley momentum fluxes in the upper valley atmosphere, but produced positive down-valley momentum fluxes below the level of the jet. Friction, calculated as a residual in the x momentum equation, was negative, as expected on physical grounds. and attained reasonable quantitative values.The strong subsidence field in the stable valley atmosphere produced subsidence warming that was only partly counteracted by down-valley cold air advection. Strong diabatic cooling was therefore required in order to account for the weak net cooling of the valley atmosphere during the nighttime period when tethered balloon observations

  1. Hesperian-aged Valleys on Martian Volcanoes: Snowmelt, Drainage, and Erosion on Ceraunius Tholus

    NASA Astrophysics Data System (ADS)

    Fassett, C. I.; Head, J. W.

    2006-12-01

    Most valley networks on Mars appear to have been formed during the Noachian. However, there are a few locations where valleys incise younger surfaces, including the Hesperian-aged volcanoes Ceraunius Tholus and Hecates Tholus (Gulick and Baker, 1990). Both of these volcanoes are characterized by numerous small radial valleys on their flanks (widths <~500 m). Ceraunius Tholus also has a set of large canyons on its north flank that appear qualitatively different from the smaller features (width ~2 km). The largest of these canyons originates near the lowest part of the caldera, continues 40 km down the north flank, and debauches into Rahe Crater (an oblique impact crater) where it formed a depositional fan. We have been exploring the origin of these relatively young valley features to help constrain valley formation mechanism on Mars. Recent study of climate change on Mars suggests that many low-latitude regions (especially large volcanic edifices) were periodically the sites of snow accumulation, likely triggered by variations in spin-axis/orbital parameters. As with earlier work on Hecates Tholus (Fassett and Head, 2006), numerical modeling suggests that conductive cooling from intrusions of plausible geometry within Ceraunius Tholus would provide sufficient surface heat flux to melt snowpack of a few hundred meters in thickness on these volcanoes. We interpret this process to have formed the radial valleys. Due to the geometry of the summit, meltwater would also have accumulated in the summit caldera, forming a caldera lake of significant volume. It appears that catastrophic drainage of this summit caldera lake may have formed the large canyons, in a manner most akin to terrestrial jökulhaups. The hypothesis that these canyons formed fluvially is supported by comes from the similarity in the volume of material removed from the valley and found in its depositional fan (both ~20 km3), consistent with its formation by a mechanism that was predominantly erosional

  2. Growth Predictions for Tree Species Planted on Marginal Soybean Lands in the Lower Mississippi Valley

    Treesearch

    J.W. Groninger; W.M. Aust; M. Miwa; John A. Stanturf

    2000-01-01

    The establishment of bottomland hardwood forest stands and riparian buffers on frequently-flooded soybean (Glycine max.) lands in the Lower Mississippi Valley represents a tremendous opporunity to prvide both economic and environmental benefits to the region. Selecting appropriate sites for reestablishing tree cover, accurately predicting the productivity of planted...

  3. Chemistry and Mineralogy of Antarctica Dry Valley Soils: Implications for Mars

    NASA Technical Reports Server (NTRS)

    Quinn, J. E.; Golden, D. C.; Graff, T. G.; Ming, D. W.; Morris, R. V.; Douglas, S.; Kounaves, S. P.; McKay, C. P.; Tamppari, L, K.; Smith, P. H.; hide

    2011-01-01

    The Antarctic Dry Valleys (ADV) comprise the largest ice-free region of Antarctica. Precipitation almost always occurs as snow, relative humidity is frequently low, and mean annual temperatures are about -20 C. The ADV soils have previously been categorized into three soil moisture regimes: subxerous, xerous and ultraxerous, based on elevation and climate influences. The subxerous regime is predominately a coastal zone soil, and has the highest average temperature and precipitation, while the ultraxerous regime occurs at high elevation (>1000 m) and have very low temperature and precipitation. The amounts and types of salts present in the soils vary between regions. The nature, origin and significance of salts in the ADV have been previously investigated. Substantial work has focused on soil formation in the ADVs, however, little work has focused on the mineralogy of secondary alteration phases. The dominant weathering process in the ADV region is physical weathering, however, chemical weathering has been well documented. The objective of this study was to characterize the chemistry and mineralogy, including the alteration mineralogy, of soils from two sites, a subxerous soil in Taylor Valley, and an ultraxerous soil in University Valley. The style of aqueous alteration in the ADVs may have implications for pedogenic processes on Mars.

  4. Radioactive cesium isotope ratios as a tool for determining dispersal and re-dispersal mechanisms downwind from the Nevada Nuclear Security Site.

    PubMed

    Snyder, Darin C; Delmore, James E; Tranter, Troy; Mann, Nick R; Abbott, Michael L; Olson, John E

    2012-08-01

    Fractionation of the two longer-lived radioactive cesium isotopes ((135)Cs and (137)Cs) produced by above ground nuclear tests have been measured and used to clarify the dispersal mechanisms of cesium deposited in the area between the Nevada Nuclear Security Site and Lake Mead in the southwestern United States. Fractionation of these isotopes is due to the 135-decay chain requiring several days to completely decay to (135)Cs, and the 137-decay chain less than one hour decay to (137)Cs. Since the Cs precursors are gases, iodine and xenon, the (135)Cs plume was deposited farther downwind than the (137)Cs plume. Sediment core samples were obtained from the Las Vegas arm of Lake Mead, sub-sampled and analyzed for (135)Cs/(137)Cs ratios by thermal ionization mass spectrometry. The layers proved to have nearly identical highly fractionated isotope ratios. This information is consistent with a model where the cesium was initially deposited onto the land area draining into Lake Mead and the composite from all of the above ground shots subsequently washed onto Lake Mead by high intensity rain and wind storms producing a layering of Cs activity, where each layer is a portion of the composite. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Dispersal Patterns of Coastal Fish: Implications for Designing Networks of Marine Protected Areas

    PubMed Central

    Di Franco, Antonio; Gillanders, Bronwyn M.; De Benedetto, Giuseppe; Pennetta, Antonio; De Leo, Giulio A.; Guidetti, Paolo

    2012-01-01

    Information about dispersal scales of fish at various life history stages is critical for successful design of networks of marine protected areas, but is lacking for most species and regions. Otolith chemistry provides an opportunity to investigate dispersal patterns at a number of life history stages. Our aim was to assess patterns of larval and post-settlement (i.e. between settlement and recruitment) dispersal at two different spatial scales in a Mediterranean coastal fish (i.e. white sea bream, Diplodus sargus sargus) using otolith chemistry. At a large spatial scale (∼200 km) we investigated natal origin of fish and at a smaller scale (∼30 km) we assessed “site fidelity” (i.e. post-settlement dispersal until recruitment). Larvae dispersed from three spawning areas, and a single spawning area supplied post-settlers (proxy of larval supply) to sites spread from 100 to 200 km of coastline. Post-settlement dispersal occurred within the scale examined of ∼30 km, although about a third of post-settlers were recruits in the same sites where they settled. Connectivity was recorded both from a MPA to unprotected areas and vice versa. The approach adopted in the present study provides some of the first quantitative evidence of dispersal at both larval and post-settlement stages of a key species in Mediterranean rocky reefs. Similar data taken from a number of species are needed to effectively design both single marine protected areas and networks of marine protected areas. PMID:22355388

  6. Victor Valley College Agreement between the Victor Valley Community College District and the Victor Valley College California Teachers Association Chapter 1170. July 1989 - June 1992.

    ERIC Educational Resources Information Center

    Victor Valley Community Coll. District, Victorville, CA.

    The collective bargaining agreement between the Victor Valley College Board of Trustees and the Victor Valley College California Teachers Association/National Education Association is presented. This contract, covering the period from July 1989 through June 1992, deals with the following topics: bargaining agent recognition; district and…

  7. Valley spin polarization of Tl/Si(111)

    NASA Astrophysics Data System (ADS)

    Stolwijk, Sebastian D.; Schmidt, Anke B.; Sakamoto, Kazuyuki; Krüger, Peter; Donath, Markus

    2017-11-01

    The metal/semiconductor hybrid system Tl/Si(111)-(1 ×1 ) exhibits a unique Tl-derived surface state with remarkable properties. It lies within the silicon band gap and forms spin-momentum-locked valleys close to the Fermi energy at the K ¯ and K¯' points. These valleys are completely spin polarized with opposite spin orientation at K ¯ and K¯' and show a giant spin splitting of more than 0.5 eV. We present a detailed preparation study of the surface system and demonstrate that the electronic valleys are extremely robust, surviving exposure to 100 L hydrogen and 500 L oxygen. We investigate the influence of additional Tl atoms on the spin-polarized valleys. By combining photoemission and inverse photoemission, we prove the existence of fully spin-polarized valleys crossing the Fermi level. Moreover, these metallic valleys carry opposite Berry curvature at K ¯ and K¯', very similar to WSe2, promising a large spin Hall effect. Thus, Tl/Si(111)-(1 ×1 ) possesses all necessary key properties for spintronic applications.

  8. Electrical valley filtering in transition metal dichalcogenides

    NASA Astrophysics Data System (ADS)

    Hsieh, Tzu-Chi; Chou, Mei-Yin; Wu, Yu-Shu

    2018-03-01

    This work investigates the feasibility of electrical valley filtering for holes in transition metal dichalcogenides. We look specifically into the scheme that utilizes a potential barrier to produce valley-dependent tunneling rates, and perform the study with both a k .p -based analytic method and a recursive Green's function-based numerical method. The study yields the transmission coefficient as a function of incident energy and transverse wave vector, for holes going through lateral quantum barriers oriented in either armchair or zigzag directions, in both homogeneous and heterogeneous systems. The main findings are the following: (1) The tunneling current valley polarization increases with increasing barrier width or height; (2) both the valley-orbit interaction and band structure warping contribute to valley-dependent tunneling, with the former contribution being manifest in structures with asymmetric potential barriers, and the latter being orientation dependent and reaching maximum for transmission in the armchair direction; and (3) for transmission ˜0.1 , a tunneling current valley polarization of the order of 10 % can be achieved.

  9. Observation of valley-dependent beams in photonic graphene.

    PubMed

    Deng, Fusheng; Sun, Yong; Wang, Xiao; Xue, Rui; Li, Yuan; Jiang, Haitao; Shi, Yunlong; Chang, Kai; Chen, Hong

    2014-09-22

    Valley-dependent propagation of light in an artificial photonic hexagonal lattice, akin to electrons in graphene, is investigated in microwave regime. Both numerical and experimental results show that the valley degeneracy in the photonic graphene is broken when the frequency is away from the Dirac point. The peculiar anisotropic wave transport property due to distinct valleys is analyzed using the equifrequency contours. More interestingly, the valley-dependent self-collimation and beam splitting phenomena are experimentally demonstrated with the armchair and zigzag interfaces, respectively. Our results confirm that there are two inequivalent Dirac points that lead to two distinct valleys in photonic graphene, which could be used to control the flow of light and might be used to carry information in valley polarized beam splitter, collimator or guiding device.

  10. Relationship between selenium body burdens and tissue concentrations in fish exposed to coal ash at the Tennessee Valley Authority Kingston spill site

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mathews, Teresa J; Fortner, Allison M; Jett, Robert T

    2014-01-01

    In December 2008, 4.1 million m3 of coal ash were released into the Emory and Clinch Rivers by the Tennessee Valley Authority (TVA) Kingston Fossil Plant. Coal ash contains several contaminants, including the bioaccumulative metalloid selenium (Se). Because Se is predominantly accumulated in aquatic organisms through dietary, rather than aqueous exposure, tissue-based toxicity thresholds for Se are currently being considered. The proposed threshold concentrations range between 4-9 g/g Se (dry wt.) in whole body fish, with a proposed fillet threshold of 11.8 g/g. In the present study we examined the spatial and temporal trends in Se bioaccumulation and examined themore » relationship between the Se content in fillets and in whole bodies of fish collected around the Kingston spill site to determine whether Se bioaccumulation was a significant concern at the ash spill site. While Se concentrations in fish (whole bodies and fillets) were elevated at sampling locations affected by the Kingston ash spill relative to reference locations, concentrations do not appear to be above risk thresholds and have not been increasing over the five year period since the spill. Our results are not only relevant to guiding the human health and ecological risk assessments at the Kingston ash spill site, but because of current national discussions on appropriate guidelines for Se in fish as well for the disposal of coal combustion wastes, our results are also relevant to the general understanding of Se bioaccumulation in contaminated water bodies.« less

  11. 27 CFR 9.58 - Carmel Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ....” (b) Approved maps. The approved maps for determining the boundary of the Carmel Valley viticultural... Ridge, Calif., dated 1956; and (5) Rana Creek, Calif., dated 1956. (c) Boundary. The Carmel Valley...

  12. 27 CFR 9.58 - Carmel Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ....” (b) Approved maps. The approved maps for determining the boundary of the Carmel Valley viticultural... Ridge, Calif., dated 1956; and (5) Rana Creek, Calif., dated 1956. (c) Boundary. The Carmel Valley...

  13. Optical manipulation of valley pseduospin in 2D semiconductors

    NASA Astrophysics Data System (ADS)

    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.

  14. Opportunity, Geologic and Structural Context of Aqueous Alteration in Noachian Outcrops, Marathon Valley and Rim and Endeavour Crater

    NASA Technical Reports Server (NTRS)

    Crumpler, L. S.; Arvidson, R. E.; Mittlefehldt, D. W.; Jolliff, B. L.; Farrand, W. H.; Fox, V.; Golombek, M. P.

    2016-01-01

    In its 12th year of exploration and 1600 sols since arrival at the rim of the 22 km-diameter Noachian Endeavour impact crater, Mars Exploration Rover Opportunity traversed from the summit of the western rim segment "Cape Tribulation" to "Marathon Valley", a shallow trough dissecting the rim and the site of strong orbital detection of smectites. In situ analysis of the exposures within Marathon Valley is establishing some of the geologic and geochemical controls on the aqueous alteration responsible for smectite detection known to occur in crater rims throughout Noachian terrains of Mars.

  15. Suggestions for a Silvicultural Prescription for Cerulean Warblers in the Lower Mississippi Alluvial Valley

    Treesearch

    Paul B. Hamel

    2005-01-01

    Conservation of species with high Partners in Flight concern scores may require active habitat management. Cerulean Warbler (Dendroica cerulea) occurs at low numbers in the Lower Mississippi Alluvial Valley in the western part of its breeding range. A study of the breeding ecology of the species was initiated in 1992 on three sites there....

  16. The Prehistory and Paleoenvironment of Hominy Creek Valley. 1979 Field Season,

    DTIC Science & Technology

    1982-01-01

    study of Hiominy Creek Valley (Henry, 1977a:1-5). The program focuses on the definition of adaptive strate- gies throughout the prehistoric occupation...area of the shelter is estimated 75m 2 with approximately one-fifth of this area covered by rockfall . The cellng is generally level with a height...greater rates of deposition than fewer numbers Gi occupants. These open floodplain sites may LW -98- well have represented alternative encampments to the

  17. Origin of the Valley Networks On Mars: A Hydrological Perspective

    NASA Technical Reports Server (NTRS)

    Gulick, Virginia C.

    2000-01-01

    The geomorphology of the Martian valley networks is examined from a hydrological perspective for their compatibility with an origin by rainfall, globally higher heat flow, and localized hydrothermal systems. Comparison of morphology and spatial distribution of valleys on geologic surfaces with terrestrial fluvial valleys suggests that most Martian valleys are probably not indicative of a rainfall origin, nor are they indicative of formation by an early global uniformly higher heat flow. In general, valleys are not uniformly distributed within geologic surface units as are terrestrial fluvial valleys. Valleys tend to form either as isolated systems or in clusters on a geologic surface unit leaving large expanses of the unit virtually untouched by erosion. With the exception of fluvial valleys on some volcanoes, most Martian valleys exhibit a sapping morphology and do not appear to have formed along with those that exhibit a runoff morphology. In contrast, terrestrial sapping valleys form from and along with runoff valleys. The isolated or clustered distribution of valleys suggests localized water sources were important in drainage development. Persistent ground-water outflow driven by localized, but vigorous hydrothermal circulation associated with magmatism, volcanism, impacts, or tectonism is, however, consistent with valley morphology and distribution. Snowfall from sublimating ice-covered lakes or seas may have provided an atmospheric water source for the formation of some valleys in regions where the surface is easily eroded and where localized geothermal/hydrothermal activity is sufficient to melt accumulated snowpacks.

  18. EPA Region 1 - Valley Depth in Meters

    EPA Pesticide Factsheets

    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 (USGS, 30m) by finding the local average elevation, subtracting the actual elevation from the average, and selecting areas where the actual elevation was below the average. The landscape was sampled at seven scales (circles of 1, 2, 4, 7, 11, 16, and 22 km radius) to take into account the diversity of valley shapes and sizes. Areas selected in at least four scales were designated as valleys.

  19. Estimated ground-water discharge by evapotranspiration from Death Valley, California, 1997-2001

    USGS Publications Warehouse

    DeMeo, Guy A.; Laczniak, Randell J.; Boyd, Robert A.; Smith, J. LaRue; Nylund, Walter E.

    2003-01-01

    The U.S. Geological Survey, in cooperation with the National Park Service and Inyo County, Calif., collected field data from 1997 through 2001 to accurately estimate the amount of annual ground-water discharge by evapotranspiration (ET) from the floor of Death Valley, California. Multispectral satellite-imagery and National Wetlands Inventory data are used to delineate evaporative ground-water discharge areas on the Death Valley floor. These areas are divided into five general units where ground-water discharge from ET is considered to be significant. Based upon similarities in soil type, soil moisture, vegetation type, and vegetation density; the ET units are salt-encrusted playa (21,287 acres), bare-soil playa (75,922 acres), low-density vegetation (6,625 acres), moderate-density vegetation (5,019 acres), and high-density vegetation (1,522 acres). Annual ET was computed for ET units with micrometeorological data which were continuously measured at six instrumented sites. Total ET was determined at sites that were chosen for their soil- and vegetated-surface conditions, which include salt-encrusted playa (extensive salt encrustation) 0.17 feet per year, bare-soil playa (silt and salt encrustation) 0.21 feet per year, pickleweed (pickleweed plants, low-density vegetation) 0.60 feet per year, Eagle Borax (arrowweed plants and salt grass, moderate-density vegetation) 1.99 feet per year, Mesquite Flat (mesquite trees, high-density vegetation) 2.86 feet per year, and Mesquite Flat mixed grasses (mixed meadow grasses, high-density vegetation) 3.90 feet per year. Precipitation, flooding, and ground-water discharge satisfy ET demand in Death Valley. Ground-water discharge is estimated by deducting local precipitation and flooding from cumulative ET estimates. Discharge rates from ET units were not estimated directly because the range of vegetation units far exceeded the five specific vegetation units that were measured. The rate of annual ground-water discharge by ET for

  20. Candidate Mars Surveyor Landing Sites Near Apollinaris Patera

    NASA Astrophysics Data System (ADS)

    Gulick, Virginia C.

    1999-06-01

    Regions near Apollinaris Patera are proposed for consideration as Mars Surveyor landing sites. Gulick (1998) proposed this region at the First Mars Surveyor Landing Site workshop; Bulmer and Gregg (1998) provided additional support. Apollinaris Patera is situated on the highlands/lowlands boundary at 8.5S, 186W. The volcano itself has been mapped as Hesperian in age. The regions surrounding Apollinaris show evidence for volcanism, volcano-ice interactions, and erosion by water. Numerous valleys modified by fluvial processes dissect a large fan structure emanating from the southern flank of the volcano. Sapping valleys have formed along the southern terminus of the fan structure. Regions near Apollinaris Patera provide a unique opportunity to sample outcrop lithologies ranging from highland Noachian basement rocks, to Hesperian aged lava flows, channel and flood plain materials, to Amazonian volcanic, ash and channel deposits.

  1. Candidate Mars Surveyor Landing Sites Near Apollinaris Patera

    NASA Technical Reports Server (NTRS)

    Gulick, Virginia C.

    1999-01-01

    Regions near Apollinaris Patera are proposed for consideration as Mars Surveyor landing sites. Gulick (1998) proposed this region at the First Mars Surveyor Landing Site workshop; Bulmer and Gregg (1998) provided additional support. Apollinaris Patera is situated on the highlands/lowlands boundary at 8.5S, 186W. The volcano itself has been mapped as Hesperian in age. The regions surrounding Apollinaris show evidence for volcanism, volcano-ice interactions, and erosion by water. Numerous valleys modified by fluvial processes dissect a large fan structure emanating from the southern flank of the volcano. Sapping valleys have formed along the southern terminus of the fan structure. Regions near Apollinaris Patera provide a unique opportunity to sample outcrop lithologies ranging from highland Noachian basement rocks, to Hesperian aged lava flows, channel and flood plain materials, to Amazonian volcanic, ash and channel deposits.

  2. Christmas Valley Renewable Energy Assessment

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Del Mar, Robert

    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 landmore » 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« less

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

    USGS Publications Warehouse

    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. Surface slip during large Owens Valley earthquakes

    NASA Astrophysics Data System (ADS)

    Haddon, E. K.; Amos, C. B.; Zielke, O.; Jayko, A. S.; Bürgmann, R.

    2016-06-01

    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 ˜1.0 to 6.0 m and average 3.3 ± 1.1 m (2σ). Vertical offsets are predominantly east-down between ˜0.1 and 2.4 m, with a mean of 0.8 ± 0.5 m. The average lateral-to-vertical ratio compiled at specific sites is ˜6:1. Summing displacements across subparallel, overlapping rupture traces implies a maximum of 7-11 m and net average of 4.4 ± 1.5 m, corresponding to a geologic Mw ˜7.5 for the 1872 event. We attribute progressively higher-offset lateral COPD peaks at 7.1 ± 2.0 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 ˜0.6 and 1.6 mm/yr (1σ) over the late Quaternary.

  5. Surface slip during large Owens Valley earthquakes

    USGS Publications Warehouse

    Haddon, E.K.; Amos, C.B.; Zielke, O.; Jayko, Angela S.; Burgmann, R.

    2016-01-01

    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 ∼1.0 to 6.0 m and average 3.3 ± 1.1 m (2σ). Vertical offsets are predominantly east-down between ∼0.1 and 2.4 m, with a mean of 0.8 ± 0.5 m. The average lateral-to-vertical ratio compiled at specific sites is ∼6:1. Summing displacements across subparallel, overlapping rupture traces implies a maximum of 7–11 m and net average of 4.4 ± 1.5 m, corresponding to a geologic Mw ∼7.5 for the 1872 event. We attribute progressively higher-offset lateral COPD peaks at 7.1 ± 2.0 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 ∼0.6 and 1.6 mm/yr (1σ) over the late Quaternary.

  6. Measurements and Modeling of Turbulent Fluxes during Persistent Cold Air Pool Events in Salt Lake Valley, Utah

    NASA Astrophysics Data System (ADS)

    Ivey, C. E.; Sun, X.; Holmes, H.

    2017-12-01

    Land surface processes are important in meteorology and climate research since they control the partitioning of surface energy and water exchange at the earth's surface. The surface layer is coupled to the planetary boundary layer (PBL) by surface fluxes, which serve as sinks or sources of energy, moisture, momentum, and atmospheric pollutants. Quantifying the surface heat and momentum fluxes at the land-atmosphere interface, especially for different surface land cover types, is important because they can further influence the atmospheric dynamics, vertical mixing, and transport processes that impact local, regional, and global climate. A cold air pool (CAP) forms when a topographic depression (i.e., valley) fills with cold air, where the air in the stagnant layer is colder than the air aloft. Insufficient surface heating, which is not able to sufficiently erode the temperature inversion that forms during the nighttime stable boundary layer, can lead to the formation of persistent CAPs during wintertime. These persistent CAPs can last for days, or even weeks, and are associated with increased air pollution concentrations. Thus, realistic simulations of the land-atmosphere exchange are meaningful to achieve improved predictions of the accumulation, transport, and dispersion of air pollution concentrations. The focus of this presentation is on observations and modeling results using turbulence data collected in Salt Lake Valley, Utah during the 2010-2011 wintertime Persistent Cold Air Pool Study (PCAPS). Turbulent fluxes and the surface energy balance over seven land use types are quantified. The urban site has an energy balance ratio (EBR) larger than one (1.276). Negative Bowen ratio (-0.070) is found at the cropland site. In addition to turbulence observations, half-hourly WRF simulated net radiation, latent heat, sensible heat, ground heat fluxes during one persistent CAP event are evaluated using the PCAPS observations. The results show that sensible and latent

  7. Interpretation of magnetotelluric measurements over an electrically dispersive one-dimensional earth

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Patella, D.

    1987-01-01

    Frequency dispersion of electromagnetic parameters of earth materials has been widely documented in recent years. It is claimed that magnetotellurics (MT)may be significantly affected by dispersion. This paper studies the MT plane-wave interpretative problem for a one-dimensional earth characterized by the presence of dispersive layers. The theoretical properties of the MT field under the dispersion hypothesis, and the main features of the dispersion phenomenon are synthetically reviewed. The examination of previously published MT curve responses over some models of dispersive earth section shows that ambiguity can arise when interpreting MT data with no other source of information. Thus it maybemore » almost impossible to distinguish between the response of a dispersive section and an equally probable dispersion-free section. The dispersion magnetotelluric (DMT) method is proposed as a means to resolve the ambiguity. The DMT method is based on the execution, at the same site, of an MT sounding and of an always dispersion-free dc geoelectric deep sounding.« less

  8. Control of Exciton Valley Coherence in Transition Metal Dichalcogenide Monolayers

    NASA Astrophysics Data System (ADS)

    Wang, Gang

    Current research on Transition Metal Dichalcogenide (TMD) Monolayers is stimulated by their strong light-matter interaction and the possibility to use the valley index in addition to spin as an information carrier. The direct gap interband transitions in TMD monolayers are governed by chiral optical selection rules. Determined by laser helicity, optical transitions in either the K+ or K- valley in momentum space are induced. Very recently the optical generation of valley polarization and valley coherence (coherent superposition of valley states) have been reported. In this work we go a step further by discussing the coherent manipulation of valley states. Linearly polarized laser excitation prepares a coherent superposition of valley states. We demonstrate the control of the exciton valley coherence in monolayer WSe2 by tuning the applied magnetic field perpendicular to the monolayer plane. The induced valley Zeeman splitting between K+ and K- results in a change of the oscillation frequency of the superposition of the valley states, which corresponds to a rotation of the exciton valley pseudo-spin. We show rotation of this coherent superposition of valley states by angles as large as 30 degrees in applied fields up to 9T and discuss valley coherence in other TMD monolayer materials. This exciton valley coherence control on ps time scale could be an important step towards complete control of qubits based on the valley degree of freedom. In collaboration with X. Marie, T. Amand, C. Robert, F. Cadiz, P. Renucci, B. Urbaszek (Université de Toulouse, INSA-CNRS-UPS, LPCNO, France), B. L. Liu (Institute of Physics, Chinese Academy of Sciences, China) and we acknowledge ERC Grant No. 306719.

  9. Geology and water resources of Owens Valley, California

    USGS Publications Warehouse

    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

  10. EXAMINATION OF HABITAT USE AND DISPERSAL OF EXOTIC BULLFROGS AND THEIR POTENTIAL IMPACT ON NATIVE AMPHIBIAN COMMUNITIES IN THE WILLAMETTE VALLEY, OREGON

    EPA Science Inventory

    Bullfrogs (Rana catesbeiana) are exotic in the west and have been implicated in the decline of western pond turtles and native ranids. Habitat alterations that favor bullfrogs have enhanced populations, particularly in agricultural areas such as the Willamette Valley. I will pres...

  11. Hydrology of the Melton Valley radioactive-waste burial grounds at Oak Ridge National Laboratory, Tennessee

    USGS Publications Warehouse

    Webster, D.A.; Bradley, Michael W.

    1988-01-01

    Burial grounds 4, 5, and 6 of the Melton Valley Radioactive-waste Burial Grounds, Oak Ridge, TN, were used sequentially from 1951 to the present for the disposal of solid, low level radioactive waste by burial in shallow trenches and auger holes. Abundant rainfall, a generally thin unsaturated zone, geologic media of inherently low permeability, and the operational practices employed have contributed to partial saturation of the buried waste, leaching of radionuclides, and transport of dissolved matter from the burial areas. Two primary methods of movement of wastes from these sites are transport in groundwater, and the overflow of fluid in trenches and subsequent flow across land surface. Whiteoak Creek and its tributaries receive all overland flow from trench spillage, surface runoff from each site, and discharge of groundwater from the regolith of each site. Potentiometric data, locally, indicate that this drainage system also receives groundwater discharges from the bedrock of burial ground 5. By projection of the bedrock flow patterns characteristic of this site to other areas of Melton Valley, it is inferred that discharges from the bedrock underlying burial grounds 4 and 6 also is to the Whiteoak Creek drainage system. The differences in potentiometric heads and a comparatively thin saturated zone in bedrock do not favor the development of deep flow through bedrock from one river system to another. (USGS)

  12. Evidence for fish dispersal from spatial analysis of stream network topology

    USGS Publications Warehouse

    Hitt, N.P.; Angermeier, P.L.

    2008-01-01

    Developing spatially explicit conservation strategies for stream fishes requires an understanding of the spatial structure of dispersal within stream networks. We explored spatial patterns of stream fish dispersal by evaluating how the size and proximity of connected streams (i.e., stream network topology) explained variation in fish assemblage structure and how this relationship varied with local stream size. We used data from the US Environmental Protection Agency's Environmental Monitoring and Assessment Program in wadeable streams of the Mid-Atlantic Highlands region (n = 308 sites). We quantified stream network topology with a continuous analysis based on the rate of downstream flow accumulation from sites and with a discrete analysis based on the presence of mainstem river confluences (i.e., basin area >250 km2) within 20 fluvial km (fkm) from sites. Continuous variation in stream network topology was related to local species richness within a distance of ???10 fkm, suggesting an influence of fish dispersal within this spatial grain. This effect was explained largely by catostomid species, cyprinid species, and riverine species, but was not explained by zoogeographic regions, ecoregions, sampling period, or spatial autocorrelation. Sites near mainstem river confluences supported greater species richness and abundance of catostomid, cyprinid, and ictalurid fishes than did sites >20 fkm from such confluences. Assemblages at sites on the smallest streams were not related to stream network topology, consistent with the hypothesis that local stream size regulates the influence of regional dispersal. These results demonstrate that the size and proximity of connected streams influence the spatial distribution of fish and suggest that these influences can be incorporated into the designs of stream bioassessments and reserves to enhance management efficacy. ?? 2008 by The North American Benthological Society.

  13. Sensitivity Tests Between Vs30 and Detailed Shear Wave Profiles Using 1D and 3D Site Response Analysis, Las Vegas Valley

    NASA Astrophysics Data System (ADS)

    West, Loyd Travis

    Site characterization is an essential aspect of hazard analysis and the time-averaged shear-wave velocity to 30 m depth "Vs30" for site-class has become a critical parameter in site-specific and probabilistic hazard analysis. Yet, the general applicability of Vs30 can be ambiguous and much debate and research surround its application. In 2007, in part to mitigate the uncertainty associated with the use of Vs30 in Las Vegas Valley, the Clark County Building Department (CCBD) in collaboration with the Nevada System of Higher Education (NSHE) embarked on an endeavor to map Vs30 using a geophysical methods approach for a site-class microzonation map of over 500 square miles (1500 km2) in southern Nevada. The resulting dataset, described by Pancha et al. (2017), contains over 10,700 1D shear-wave-velocity-depth profiles (SWVP) that constitute a rich database of 3D shear-wave velocity structure that is both laterally and vertical heterogenous. This study capitalizes on the uniquely detailed and spatially dense CCBD database to carry out sensitivity tests on the detailed shear-wave-velocity-profiles and the Vs30 utilizing 1D and 3D site-response approaches. Sensitivity tests are derived from the 1D oscillator response of a single-degree-of-freedom-oscillator and from 3D finite-difference deterministic simulations up to 15 Hz frequency using similar model parameters. Results demonstrate that the detailed SWVP are amplifying ground motions by roughly 50% over the simple Vs30 models, above 4.6 Hz frequency. Numerical simulations also depict significant lateral resonance, focusing, and scattering from seismic energy attributed to the 3D small-scale heterogeneities of the shear-wave-velocity profiles that result in a 70% increase in peak ground velocity. Additionally, PGV ratio maps clearly establish that the increased amplification from the detailed SWVPs is consistent throughout the model space. As a corollary, this study demonstrates the use of finite-differencing numerical

  14. Initial vegetation species and senescience/stress indicator mapping in the San Luis Valley, Colorado using imaging spectrometer data

    NASA Technical Reports Server (NTRS)

    Clark, Roger N.; King, Trude V. V.; Ager, Cathy; Swayze, Gregg A.

    1995-01-01

    We analyzed AVIRIS data obtained over agricultural areas in the San Luis Valley of Colorado. The data were acquired on September 3, 1993. A combined method of radiative transfer modeling and ground calibration site reflectance was used to correct the flight data to surface reflectance. This method, called Radiative Transfer Ground Calibration, or RTGC, corrects for variable water vapor in the atmosphere and produces spectra free of artifacts with spectral channel to channel noise approaching the signal to noise of the raw data. The calibration site soil samples were obtained on the day of the overflight and measured on our laboratory spectrometer. The site was near the center of the AVIRIS scene and the spectra of the soil is spectrally bland, especially in the region of the chlorophyll absorption in the visible portion of the spectrum. The center of the scene is located at approximately 106 deg 03' longitude, 37 deg 23' latitude, and the scene covers about 92 square kilometers. This scene is one of 28 in the area for a general project to study the Summitville abandoned mine site, located in the mountains west of the San Luis Valley, and its effects on the surrounding environment.

  15. Geology of the north end of the Salt Valley Anticline, Grand County, Utah

    USGS Publications Warehouse

    Gard, Leonard Meade

    1976-01-01

    This report describes the geology and hydrology of a portion of the Salt Valley anticline lying north of Moab, Utah, that is being studied as a potential site for underground storage of nuclear waste in salt. Selection of this area was based on recommendations made in an earlier appraisal of the potential of Paradox basin salt deposits for such use. Part of sec. 5, T. 23 S., R. 20 E. has been selected as a site for subsurface investigation as a potential repository for radioactive waste. This site has easy access to transportation, is on public land, is isolated from human habitation, is not visible from Arches National Park, and the salt body lies within about 800 feet (244 m) of the surface. Further exploration should include investigation of possible ground water in the caprock and physical exploration of the salt body to identify a thick bed of salt for use as a storage zone that can be isolated from the shaly interbeds that possibly contain quantities of hydrocarbons. Salt Valley anticline, a northwest-trending diapiric structure, consists of Mesozoic sedimentary rocks arched over a thick core of salt of the Paradox Member of the Middle Pennsylvanian Hermosa Formation. Salt began to migrate to form and/or develop this structure shortly after it was deposited, probably in response to faulting. This migration caused upwelling of the salt creating a linear positive area. This positive area, in turn, caused increased deposition of sediments in adjacent areas which further enhanced salt migration. Not until late Jurassic time had flowage of the salt slowed sufficiently to allow sediments of the Morrison and younger formations to be deposited across the salt welt. A thick cap of insoluble residue was formed on top of the salt diapir as a result of salt dissolution through time. The crest of the anticline is breached; it collapsed in two stages during the Tertiary Period. The first stage was graben collapse during the early Tertiary; the second stage occurred after

  16. Seed dispersal by specialist versus generalist foragers: the plant's perspective

    USGS Publications Warehouse

    Larson, D.L.

    1996-01-01

    I examined the seed dispersal ecology of the stem parasitic plant, desert mistletoe (Phoradendron californicum, Viscaceae), with the objectives of (1) determining the relative effectiveness of specialist and generalist foragers for seed dispersal, (2) determining the extent to which desert mistletoe fruiting characteristics correspond to those predicted for plants attracting specialist versus generalist foragers, and (3) examining the potential consequences of the observed dispersal strategy for mistletoe reproduction. Three species of birds, phainopepla, Gila woodpecker, and northern mockingbird, fed on desert mistletoe at my study site. The specialist, phainopepla, was the most abundant and the most likely to perch in host species, where defecated seeds had a greater probability of lodging in a site suitable for establishment. Gila woodpeckers, although abundant, spent little time in host plants, thus dooming most of the seeds they consumed. Mockingbirds may disperse a small number of seeds, but were abundant enough to consume only a small portion of the available fruits. As expected for plants attracting specialist frugivores, mistletoes produced fruits throughout the 6-month season in which phainopeplas reside in the Sonoran desert. Contrary to expectation, numbers of fruits produced far exceeded the amount that could be consumed by the frugivores at my study site. Fruit crop size was positively related to absolute fruit removal, but not to proportional removal at the scale of the entire study site. However, crop size was positively related to proportional removal within the neighborhood of mistletoes occupying an individual host tree. Frugivores were attracted to infected hosts, host attractiveness increased, although proportional removal of fruit declined, with number of female mistletoes. The observed dispersal ecology of desert mistletoe suggests the likelihood of increasingly clumped distributions of mistletoe plants, as more and more seeds are deposited

  17. Relationships of field habitat measurements, visual habitat indices, and land cover to benthic macroinvertebrates in urbanized streams of the Santa Clara Valley, California

    USGS Publications Warehouse

    Fend, S.V.; Carter, J.L.; Kearns, F.R.

    2005-01-01

    We evaluated several approaches for measuring natural and anthropogenic habitat characteristics to predict benthic macroinvertebrate assemblages over a range of urban intensity at 85 stream sites in the Santa Clara Valley, California. Land cover was summarized as percentage urban land cover and impervious area within upstream buffers and the upstream subwatersheds. Field measurements characterized water chemistry, channel slope, sediment, and riparian canopy. In . addition to applying the visual-based habitat assessment in U.S. Environmental Protection Agency's rapid bioassessment protocol, we developed a simplified urban habitat assessment index based on turbidity, fine sediment deposition, riparian condition, and channel modification. Natural and anthropogenic habitat variables covaried along longitudinal stream gradients and were highly correlated with elevation. At the scale of the entire watershed, benthic macroinvertebrate measures were equally correlated with variables expressing natural gradients and urbanization effects. When natural gradients were reduced by partitioning sites into ecoregion subsection groupings, habitat variables most highly correlated with macroinvertebrate measures differed between upland and valley floor site groups. Among the valley floor sites, channel slope and physical modification of channel and riparian habitats appeared more important than upstream land cover or water quality in determining macroinvertebrate richness and ordination scores. Among upland sites, effects of upstream reservoir releases on habitat quality appeared important. Rapid habitat evaluation methods appeared to be an effective method for describing habitat features important to benthic macroinvertebrates when adapted for the region and the disturbance of interest. ?? 2005 by the American Fisheries Society.

  18. Refining the Subseafloor Circulation Model of the Middle Valley Hydrothermal System Using Fluid Geochemistry

    NASA Astrophysics Data System (ADS)

    Inderbitzen, K. E.; Wheat, C. G.; Baker, P. A.; Fisher, A. T.

    2014-12-01

    Currently, fluid circulation patterns and the evolution of rock/fluid compositions as circulation occurs in subseafloor hydrothermal systems are poorly constrained. Sedimented spreading centers provide a unique opportunity to study subsurface flow because sediment acts as an insulating blanket that traps heat from the cooling magma body and limits: (a) potential flow paths for seawater to recharge the aquifer in permeable upper basaltic basement and (b) points of altered fluid egress. This also allows for a range of thermal and geochemical gradients to exist near the sediment-water interface. Models of fluid circulation patterns in this type of hydrologic setting have been generated (eg. Stein and Fisher, 2001); however fluid chemistry datasets have not previously been used to test the model's viability. We address this issue by integrating the existing circulation model with fluid compositional data collected from sediment pore waters and high temperature hydrothermal vents located in Middle Valley on the Juan de Fuca Ridge. Middle Valley hosts a variety of hydrologic regimes: including areas of fluid recharge (Site 855), active venting (Site 858/1036; Dead Dog vent field), recent venting (Site 856/1035; Bent Hill Massive Sulfide deposit) and a section of heavily sedimented basement located between recharge and discharge sites (Site 857). We will present new results based on thermal and geochemical data from the area of active venting (Sites 858 and 1036), that was collected during Ocean Drilling Program Legs 139 and 169 and a subsequent heat flow/gravity coring effort. These results illuminate fine scale controls on secondary recharge and fluid flow within the sediment section at Site 858/1036. The current status of high temperature vents in this area (based on observations made in July, 2014) will also be outlined.

  19. Land use investigations in the central valley and central coastal test sites, California

    NASA Technical Reports Server (NTRS)

    Estes, J. E.

    1973-01-01

    The Geography Remote Sensing Unit (GRSU) at the University of California, Santa Barbara is responsible for investigations with ERTS-1 data in the Central Coastal Zone and West Side of the San Joaquin Valley. The nature of investigative effort involves the inventory, monitoring, and assessment of the natural and cultural resources of the two areas. Land use, agriculture, vegetation, landforms, geology, and hydrology are the principal subjects for attention. These parameters are the key indicators of the dynamically changing character of the areas. Monitoring of these parameters with ERTS-1 data will provide the techniques and methodologies required to generate the information needed by federal, state, county, and local agencies to assess change-related phenomena and plan for management and development.

  20. Hydrology of the Little Androscoggin River Valley aquifer, Oxford County, Maine

    USGS Publications Warehouse

    Morrissey, D.J.

    1983-01-01

    The Little Androscoggin River valley aquifer, a 15-square-mile sand and gravel valley-fill aquifer in southwestern Maine, is the source of water for the towns of Norway, Oxford, and South Paris. Estimated inflows to the aquifer during the 1981 water year were 16.4 cubic feet per second from precipitation directly on the aquifer, 11.2 cubic feet per second from till covered uplands adjacent to the aquifer, and 1.4 cubic feet per second from surface-water leakage. Outflows from the aquifer were 26.7 cubic feet per second to surface water and 2.3 cubic feet per second to wells. A finite-difference ground-water flow model was used to simulate conditions observed in the aquifer during 1981. Model conditions observed in the aquifer during 1981. Model simulations indicate that a 50 percent reduction of average 1981 recharge to the aquifer would cause water level declines of up to 20 feet in some areas. Model simulations of increased pumping at a high yield well in the northern part of the aquifer indicate that resulting changes in the water table will not be sufficient to intercept groundwater contaminated by a sludge disposal site. Water in the aquifer is low in dissolved solids (average for 38 samples was 67 mg/L), slightly acidic and soft. Ground-water contamination has occurred near a sludge-disposal site and in the vicinity of a sanitary landfill. Dissolved solids in ground water near the sludge disposal site were as much as ten times greater than average background values for the aquifer. (USGS)

  1. Observation of valley-selective microwave transport in photonic crystals

    NASA Astrophysics Data System (ADS)

    Ye, Liping; Yang, Yuting; Hong Hang, Zhi; Qiu, Chunyin; Liu, Zhengyou

    2017-12-01

    Recently, the discrete valley degree of freedom has attracted extensive attention in condensed matter physics. Here, we present an experimental observation of the intriguing valley transport for microwaves in photonic crystals, including the bulk valley transport and the valley-projected edge modes along the interface separating different photonic insulating phases. For both cases, valley-selective excitations are realized by a point-like chiral source located at proper locations inside the samples. Our results are promising for exploring unprecedented routes to manipulate microwaves.

  2. Preliminary Results from VOC measurements in the Lower Fraser Valley in July/Aug 2012

    NASA Astrophysics Data System (ADS)

    Schiller, C. L.; Jones, K.; Vingarzan, R.; Leaitch, R.; Macdonald, A.; Osthoff, H. D.; Reid, K.

    2012-12-01

    In July/August 2012, a pilot study looking at the effect of ClNO2 production on the ozone concentrations in the lower Fraser valley near Abbotsford, BC was conducted. The lower Fraser valley in British Columbia Canada has some of the highest ozone concentrations and visibility issues in Canada. Abbotsford is located approximately 80 kms east of Vancouver, BC and approximately 30 kms from the ocean. The site was located in a largely agricultural area with fruit farms (raspberries and blueberries) and poultry barns predominating. During the study biogenic and anthropogenic VOCs were measured in situ using a GCMS/FID with hourly samples. Particle composition was measured using an ACSM and size distribution using an SMPS. Preliminary results from the study will be discussed.

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

    USGS Publications Warehouse

    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. Distribution and space use of seed-dispersing rodents in central Pyrenees: implications for genetic diversity, conservation and plant recruitment.

    PubMed

    Urgoiti, Jon; Muñoz, Alberto; Espelta, Josep Maria; Bonal, Raúl

    2018-01-09

    The function and conservation of many forest ecosystems depend on the distribution and diversity of the community of rodents that consume and disperse seeds. The habitat preferences and interactions are especially relevant in alpine systems where such granivorous rodents reach the southernmost limit of their distribution and are especially sensitive to global warming. We analysed the community of granivorous rodents in the Pyrenees, one of the southernmost mountain ranges of Europe. Rodent species were identified by DNA with particular attention to the Apodemus species, which are prominent seed-dispersing rodents in Europe. We confirmed for the first time the presence of the yellow-necked mouse, Apodemus flavicollis, in central Pyrenees, a typical Eurosiberian species that reaches its southernmost distribution limit in this area. We also found the wood mouse, A. sylvaticus, a related species more tolerant to Mediterranean environments. Both rodents were spatially segregated by altitude. A. sylvaticus was rare at high altitudes, which might cause the genetic differentiation between populations of the different valleys reported here. We also found other seed consumers like dormice, Elyomis quercinus, and voles, Myodes glareolus, with marked habitat preferences. We suggest that population isolation among valleys may increase the genetic diversity of rodents, like A. sylvaticus. We also highlight the potential threat that global warming may represent for species linked to high-altitude refuges at the southern edge of its distribution, like A. flavicollis. Finally, we discuss how this threat may have a dimension in the conservation of alpine forests dispersed by these rodent populations. This article is protected by copyright. All rights reserved.

  5. Relating streamflow characteristics to specialized insectivores in the Tennessee River Valley: a regional approach

    USGS Publications Warehouse

    Knight, Rodney R.; Gregory, M. Brian; Wales, Amy K.

    2008-01-01

    Analysis of hydrologic time series and fish community data across the Tennessee River Valley identified three hydrologic metrics essential to habitat suitability and food availability for insectivorous fish communities in streams of the Tennessee River Valley: constancy (flow stability or temporal invariance), frequency of moderate flooding (frequency of habitat disturbance), and rate of streamflow recession. Initial datasets included 1100 fish community sites and 300 streamgages. Reduction of these datasets to sites with coexisting data yielded 33 sites with streamflow and fish community data for analysis. Identification of critical hydrologic metrics was completed using a multivariate correlation procedure that maximizes the rank correlation between the hydrologic metrics and fish community resemblance matrices. Quantile regression was used to define thresholds of potential ranges of insectivore scores for given values of the hydrologic metrics. Increased values of constancy and insectivore scores were positively correlated. Constancy of streamflow maintains wetted perimeter, which is important for providing habitat for fish spawning and increased surface area for invertebrate colonization and reproduction. Site scores for insectivorous fish increased as the frequency of moderate flooding (3 times the median annual streamflow) decreased, suggesting that insectivorous fish communities respond positively to less frequent disturbance and a more stable habitat. Increased streamflow recession rates were associated with decreased insectivore scores. Increased streamflow recession can strand fish in pools and other areas that are disconnected from flowing water and remove invertebrates as food sources that were suspended during high-streamflow events.

  6. Afforestation of marginal agricultural land in the lower Mississippi River Alluvial Valley, U.S.A.

    Treesearch

    John A. Stanturf; Callie J. Schweitzer; Emile S. Gardiner

    1998-01-01

    Afforestation of marginal agricultural land in the Lower Mississippi Alluvial Valley (LMAV) relies on native species, planted mostly in single-species plantations. Hard mast species such as oak and pecan are favored for their value to wildlife, especially on public land. Successful afforestation requires an understanding of site variation within floodplains and...

  7. 27 CFR 9.90 - Willamette Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) “Roseburg,” Location Diagram NL 10-2, 1958 (revised 1970). (c) Boundaries. The Willamette Valley... valleys of Little River, Mosby Creek, Sharps Creek and Lost Creek to the intersection of R1W/R1E and State...

  8. Strong Motion Network of Medellín and Aburrá Valley: technical advances, seismicity records and micro-earthquake monitoring

    NASA Astrophysics Data System (ADS)

    Posada, G.; Trujillo, J. C., Sr.; Hoyos, C.; Monsalve, G.

    2017-12-01

    The tectonics setting of Colombia is determined by the interaction of Nazca, Caribbean and South American plates, together with the Panama-Choco block collision, which makes a seismically active region. Regional seismic monitoring is carried out by the National Seismological Network of Colombia and the Accelerometer National Network of Colombia. Both networks calculate locations, magnitudes, depths and accelerations, and other seismic parameters. The Medellín - Aburra Valley is located in the Northern segment of the Central Cordillera of Colombia, and according to the Colombian technical seismic norm (NSR-10), is a region of intermediate hazard, because of the proximity to seismic sources of the Valley. Seismic monitoring in the Aburra Valley began in 1996 with an accelerometer network which consisted of 38 instruments. Currently, the network consists of 26 stations and is run by the Early Warning System of Medellin and Aburra Valley (SIATA). The technical advances have allowed the real-time communication since a year ago, currently with 10 stations; post-earthquake data is processed through operationally near-real-time, obtaining quick results in terms of location, acceleration, spectrum response and Fourier analysis; this information is displayed at the SIATA web site. The strong motion database is composed by 280 earthquakes; this information is the basis for the estimation of seismic hazards and risk for the region. A basic statistical analysis of the main information was carried out, including the total recorded events per station, natural frequency, maximum accelerations, depths and magnitudes, which allowed us to identify the main seismic sources, and some seismic site parameters. With the idea of a more complete seismic monitoring and in order to identify seismic sources beneath the Valley, we are in the process of installing 10 low-cost shake seismometers for micro-earthquake monitoring. There is no historical record of earthquakes with a magnitude

  9. Dispersal constraints for stream invertebrates: setting realistic timescales for biodiversity restoration.

    PubMed

    Parkyn, Stephanie M; Smith, Brian J

    2011-09-01

    Biodiversity goals are becoming increasingly important in stream restoration. Typical models of stream restoration are based on the assumption that if habitat is restored then species will return and ecological processes will re-establish. However, a range of constraints at different scales can affect restoration success. Much of the research in stream restoration ecology has focused on habitat constraints, namely the in-stream and riparian conditions required to restore biota. Dispersal constraints are also integral to determining the timescales, trajectory and potential endpoints of a restored ecosystem. Dispersal is both a means of organism recolonization of restored sites and a vital ecological process that maintains viable populations. We review knowledge of dispersal pathways and explore the factors influencing stream invertebrate dispersal. From empirical and modeling studies of restoration in warm-temperate zones of New Zealand, we make predictions about the timescales of stream ecological restoration under differing levels of dispersal constraints. This process of constraints identification and timescale prediction is proposed as a practical step for resource managers to prioritize and appropriately monitor restoration sites and highlights that in some instances, natural recolonization and achievement of biodiversity goals may not occur.

  10. Dispersal Constraints for Stream Invertebrates: Setting Realistic Timescales for Biodiversity Restoration

    NASA Astrophysics Data System (ADS)

    Parkyn, Stephanie M.; Smith, Brian J.

    2011-09-01

    Biodiversity goals are becoming increasingly important in stream restoration. Typical models of stream restoration are based on the assumption that if habitat is restored then species will return and ecological processes will re-establish. However, a range of constraints at different scales can affect restoration success. Much of the research in stream restoration ecology has focused on habitat constraints, namely the in-stream and riparian conditions required to restore biota. Dispersal constraints are also integral to determining the timescales, trajectory and potential endpoints of a restored ecosystem. Dispersal is both a means of organism recolonization of restored sites and a vital ecological process that maintains viable populations. We review knowledge of dispersal pathways and explore the factors influencing stream invertebrate dispersal. From empirical and modeling studies of restoration in warm-temperate zones of New Zealand, we make predictions about the timescales of stream ecological restoration under differing levels of dispersal constraints. This process of constraints identification and timescale prediction is proposed as a practical step for resource managers to prioritize and appropriately monitor restoration sites and highlights that in some instances, natural recolonization and achievement of biodiversity goals may not occur.

  11. Valley photonic crystals for control of spin and topology

    NASA Astrophysics Data System (ADS)

    Dong, Jian-Wen; Chen, Xiao-Dong; Zhu, Hanyu; Wang, Yuan; Zhang, Xiang

    2017-03-01

    Photonic crystals offer unprecedented opportunity for light manipulation and applications in optical communication and sensing. Exploration of topology in photonic crystals and metamaterials with non-zero gauge field has inspired a number of intriguing optical phenomena such as one-way transport and Weyl points. Recently, a new degree of freedom, valley, has been demonstrated in two-dimensional materials. Here, we propose a concept of valley photonic crystals with electromagnetic duality symmetry but broken inversion symmetry. We observe photonic valley Hall effect originating from valley-dependent spin-split bulk bands, even in topologically trivial photonic crystals. Valley-spin locking behaviour results in selective net spin flow inside bulk valley photonic crystals. We also show the independent control of valley and topology in a single system that has been long pursued in electronic systems, resulting in topologically-protected flat edge states. Valley photonic crystals not only offer a route towards the observation of non-trivial states, but also open the way for device applications in integrated photonics and information processing using spin-dependent transportation.

  12. A review of empirical evidence on different uncanny valley hypotheses: support for perceptual mismatch as one road to the valley of eeriness

    PubMed Central

    Kätsyri, Jari; Förger, Klaus; Mäkäräinen, Meeri; Takala, Tapio

    2015-01-01

    The uncanny valley hypothesis, proposed already in the 1970s, suggests that almost but not fully humanlike artificial characters will trigger a profound sense of unease. This hypothesis has become widely acknowledged both in the popular media and scientific research. Surprisingly, empirical evidence for the hypothesis has remained inconsistent. In the present article, we reinterpret the original uncanny valley hypothesis and review empirical evidence for different theoretically motivated uncanny valley hypotheses. The uncanny valley could be understood as the naïve claim that any kind of human-likeness manipulation will lead to experienced negative affinity at close-to-realistic levels. More recent hypotheses have suggested that the uncanny valley would be caused by artificial–human categorization difficulty or by a perceptual mismatch between artificial and human features. Original formulation also suggested that movement would modulate the uncanny valley. The reviewed empirical literature failed to provide consistent support for the naïve uncanny valley hypothesis or the modulatory effects of movement. Results on the categorization difficulty hypothesis were still too scarce to allow drawing firm conclusions. In contrast, good support was found for the perceptual mismatch hypothesis. Taken together, the present review findings suggest that the uncanny valley exists only under specific conditions. More research is still needed to pinpoint the exact conditions under which the uncanny valley phenomenon manifests itself. PMID:25914661

  13. Extensive dispersal of Roanoke logperch (Percina rex) inferred from genetic marker data

    USGS Publications Warehouse

    Roberts, James H.; Angermeier, Paul; Hallerman, Eric M.

    2016-01-01

    The dispersal ecology of most stream fishes is poorly characterised, complicating conservation efforts for these species. We used microsatellite DNA marker data to characterise dispersal patterns and effective population size (Ne) for a population of Roanoke logperchPercina rex, an endangered darter (Percidae). Juveniles and candidate parents were sampled for 2 years at sites throughout the Roanoke River watershed. Dispersal was inferred via genetic assignment tests (ATs), pedigree reconstruction (PR) and estimation of lifetime dispersal distance under a genetic isolation-by-distance model. Estimates of Ne varied from 105 to 1218 individuals, depending on the estimation method. Based on PR, polygamy was frequent in parents of both sexes, with individuals spawning with an average of 2.4 mates. The sample contained 61 half-sibling pairs, but only one parent–offspring pair and no full-sib pairs, which limited our ability to discriminate natal dispersal of juveniles from breeding dispersal of their parents between spawning events. Nonetheless, all methods indicated extensive dispersal. The AT indicated unrestricted dispersal among sites ≤15 km apart, while siblings inferred by the PR were captured an average of 14 km and up to 55 km apart. Model-based estimates of median lifetime dispersal distance (6–24 km, depending on assumptions) bracketed AT and PR estimates, indicating that widely dispersed individuals do, on average, contribute to gene flow. Extensive dispersal of P. rex suggests that darters and other small benthic stream fishes may be unexpectedly mobile. Monitoring and management activities for such populations should encompass entire watersheds to fully capture population dynamics.

  14. Lateral spread hazard mapping of the northern Salt Lake Valley, Utah, for a M7.0 scenario earthquake

    USGS Publications Warehouse

    Olsen, M.J.; Bartlett, S.F.; Solomon, B.J.

    2007-01-01

    This paper describes the methodology used to develop a lateral spread-displacement hazard map for northern Salt Lake Valley, Utah, using a scenario M7.0 earthquake occurring on the Salt Lake City segment of the Wasatch fault. The mapping effort is supported by a substantial amount of geotechnical, geologic, and topographic data compiled for the Salt Lake Valley, Utah. ArcGIS?? routines created for the mapping project then input this information to perform site-specific lateral spread analyses using methods developed by Bartlett and Youd (1992) and Youd et al. (2002) at individual borehole locations. The distributions of predicted lateral spread displacements from the boreholes located spatially within a geologic unit were subsequently used to map the hazard for that particular unit. The mapped displacement zones consist of low hazard (0-0.1 m), moderate hazard (0.1-0.3 m), high hazard (0.3-1.0 m), and very high hazard (> 1.0 m). As expected, the produced map shows the highest hazard in the alluvial deposits at the center of the valley and in sandy deposits close to the fault. This mapping effort is currently being applied to the southern part of the Salt Lake Valley, Utah, and probabilistic maps are being developed for the entire valley. ?? 2007, Earthquake Engineering Research Institute.

  15. Mars Exploration Program 2007 Phoenix landing site selection and characteristics

    USGS Publications Warehouse

    Arvidson, R.; Adams, D.; Bonfiglio, G.; Christensen, P.; Cull, S.; Golombek, M.; Guinn, J.; Guinness, E.; Heet, T.; Kirk, R.; Knudson, A.; Malin, M.; Mellon, M.; McEwen, A.; Mushkin, A.; Parker, T.; Seelos, F.; Seelos, K.; Smith, P.; Spencer, D.; Stein, T.; Tamppari, L.

    2009-01-01

    To ensure a successful touchdown and subsequent surface operations, the Mars Exploration Program 2007 Phoenix Lander must land within 65?? to 72?? north latitude, at an elevation less than -3.5 km. The landing site must have relatively low wind velocities and rock and slope distributions similar to or more benign than those found at the Viking Lander 2 site. Also, the site must have a soil cover of at least several centimeters over ice or icy soil to meet science objectives of evaluating the environmental and habitability implications of past and current near-polar environments. The most challenging aspects of site selection were the extensive rock fields associated with crater rims and ejecta deposits and the centers of polygons associated with patterned ground. An extensive acquisition campaign of Odyssey Thermal Emission Imaging Spectrometer predawn thermal IR images, together with ???0.31 m/pixel Mars Reconnaissance Orbiter High Resolution Imaging Science Experiment images was implemented to find regions with acceptable rock populations and to support Monte Carlo landing simulations. The chosen site is located at 68.16?? north latitude, 233.35?? east longitude (areocentric), within a ???50 km wide (N-S) by ???300 km long (E-W) valley of relatively rock-free plains. Surfaces within the eastern portion of the valley are differentially eroded ejecta deposits from the relatively recent ???10-km-wide Heimdall crater and have fewer rocks than plains on the western portion of the valley. All surfaces exhibit polygonal ground, which is associated with fracture of icy soils, and are predicted to have only several centimeters of poorly sorted basaltic sand and dust over icy soil deposits. Copyright 2008 by the American Geophysical Union.

  16. Dispersion, controlled dispersion, and three applications

    NASA Astrophysics Data System (ADS)

    Bradshaw, Douglas H.

    Causality dictates that all physical media must be dispersive. (We will call a medium dispersive if its refractive index varies with frequency.) Ordinarily, strong dispersion is accompanied either by strong absorption or strong gain. However, over the past 15 years several groups have demonstrated that it is possible to have media that are both strongly dispersive and roughly transparent for some finite bandwidth. In these media, group and phase velocities may differ from each other by many orders of magnitude and even by sign. Relationships and intuitive models that are satisfactory when it is reasonable to neglect dispersion may then fail dramatically. In this dissertation we analyze three such cases of failure. Before looking at the specific cases, we review some basic ideas relating to dispersion. We review some of the geometric meanings of group velocity, touch on the relationship between group velocity and causality, and give some examples of techniques by which the group velocity may be manipulated. We describe the interplay between group velocity and energy density for non-absorbing dispersive media. We discuss the ideas of temporary absorption and emission as dictated by an instantaneous spectrum. We then apply these concepts in three specific areas. First, non-dispersive formulations for the momentum of light in a medium must be adjusted to account for dispersion. For over 100 years, there has been a gradual discussion of the proper form for the per-photon momentum. Two forms, each of which has experimental relevance in a 'dispersionless' medium, are the Abraham momentum, and the Minkowski momentum. If h is the angular frequency, n is the refractive index, h is Planck's constant, and c is the speed of light, then these reduce in a dispersionless medium to per-photon momenta of ho/(nc), and nho/c respectively. A simple generalization of the two momenta to dispersive media entails multiplying each per-photon momentum by n/ng, where ng is the group

  17. Gravity survey of Dixie Valley, west-central Nevada

    USGS Publications Warehouse

    Schaefer, Donald H.

    1983-01-01

    Dixie Valley, a northeast-trending structural trough typical of valleys in the Basin and Range Province, is filled with a maximum of about 10,000 feet of alluvial and lacustrine deposits , as estimated from residual-gravity measurements obtained in this study. On the basis of gravity measurements at 300 stations on nine east-west profiles, the gravity residuals reach a maximum of 30 milligals near the south-central part of the valley. Results from a three-dimensional inversion model indicate that the central depression of the valley is offset to the west of the geographic axis. This offset is probably due to major faulting along the west side of the valley adjacent to the Stillwater Range. Comparison of depths to bedrock obtained during this study and depths obtained from a previous seismic-refraction study indicates a reasonably good correlation. A heterogeneous distribution of densities within the valley-fill deposits would account for differing depths determined by the two methods. (USGS)

  18. Examination of climatological wind patterns and simulated pollen dispersion in a complex island environment

    NASA Astrophysics Data System (ADS)

    Viner, Brian J.; Arritt, Raymond W.; Westgate, Mark E.

    2017-08-01

    Complex terrain creates small-scale circulations which affect pollen dispersion but may be missed by meteorological observing networks and coarse-grid meteorological models. On volcanic islands, these circulations result from differing rates of surface heating between land and sea as well as rugged terrain. We simulated the transport of bentgrass, ryegrass, and maize pollen from 30 sources within the agricultural regions of the Hawaiian island Kaua'i during climatological conditions spanning season conditions and the La Niña, El Niño, and neutral phases of the El Niño-Southern Oscillation. Both pollen size and source location had major effects on predicted dispersion over and near the island. Three patterns of pollen dispersion were identified in response to prevailing wind conditions: southwest winds transported pollen inland, funneling pollen grains through valleys; east winds transported pollen over the ocean, with dispersive tails for the smallest pollen grains following the mean wind and extending as far as the island of Ni'ihau 35 km away; and northeast winds moved pollen inland counter to the prevailing flow due to a sea breeze circulation that formed over the source region. These results are the first to predict the interactions between complex island terrain and local climatology on grass pollen dispersion. They demonstrate how numerical modeling can provide guidance for field trials by illustrating the common flow regimes present in complex terrain, allowing field trials to focus on areas where successful sampling is more likely to occur.

  19. Rates of Eolian Rock Abrasion in the Ice-Free Valleys, Antarctica

    NASA Astrophysics Data System (ADS)

    Hallet, B.; Malin, M. C.; Sletten, R. S.

    2016-12-01

    Eolian abrasion is a principal surface process in dry regions of Earth and Mars and there is evidence for wind processes active on Venus and Titan. Rock abrasion also has practical significance in diverse fields ranging from preservation of cultural material (artifacts, monuments) to damage of solar panels and windshields in arid regions. Despite its scientific and practical importance, and there have ben only few studies that define rates of rock abrasion quantitatively under natural conditions. Herein we report abrasion rates that have been exceptionally well characterized through a unique long-term (30+-year) field experiment in the ice-free McMurdo Dry Valleys, Antarctica. In 1983 and 1984, over 5000 rock targets of several lithologies (25.4 mm-diameter and 5 mm-thick disks of dolerite, basalt, tuff and sandstone) were installed at five heights (7,14, 21, 35, and 70 cm) facing the 4 cardinal directions at 10 locations (one additional site contains fewer targets). Sequential collections of rock targets exposed to abrasion enable definition of mass loss after 1, 5, 10, 30 and 31 years of exposure; the latter were retrieved during the 2014-2015 season. The abrasion rates generally show striking consistency for each lithology at any site; the multiple targets permit definition of intrinsic differences in mass loss. The rates vary considerably from site to site owing to differences in availability of transportable sediment, wind regime, and surface roughness, and at each site, owing to target orientation relative to the dominant winds and, secondarily, to height above the ground. For the hardest targets, basalt and dolerite, mass loss in 30+ years ranged from essentially zero at some sites to 1/3 of the deployed mass (2.59 g; equivalent to a rock thickness >1.8 mm) where abrasion was most active (Site 7, Central Wright Valley). The tuff targets showed the greatest mass loss, and in many cases were entirely abraded away by the end of the experiment.Current work is

  20. Trend in Air Quality of Kathmandu Valley: A Satellite, Observation and Modelling Perspective

    NASA Astrophysics Data System (ADS)

    Mahapatra, P. S.; Praveen, P. S.; Adhikary, B.; Panday, A. K.; Putero, D.; Bonasoni, P.

    2016-12-01

    Kathmandu (floor area of 340 km2) in Nepal is considered to be a `hot spot' of urban air pollution in South Asia. Its structure as a flat basin surrounded by tall mountains provides a unique case study for analyzing pollution trapped by topography. Only a very small number of cities with similar features have been studied extensively including Mexico and Santiago-de-Chile. This study presents the trend in satellite derived Aerosol Optical Depth (AOD) from MODIS AQUA and TERRA (3x3km, Level 2) over Kathmandu from 2000 to 2015. Trend analysis of AOD shows 35% increase during the study period. Determination of the background pollution would reveal the contribution of only Kathmandu Valley for the observation period. For this, AOD at 1340m altitude outside Kathmandu, but nearby areas were considered as background. This analysis was further supported by investigating AOD at different heights around Kathmandu as well as determining AOD from CALIPSO vertical profiles. These analysis suggest that background AOD contributed 30% in winter and 60% in summer to Kathmandu Valley's observed AOD. Thereafter the background AOD was subtracted from total Kathmandu AOD to determine contribution of only Kathmandu Valley's AOD. Trend analysis of only Kathmandu Valley AOD (subtracting background AOD) suggested an increase of 50% during the study period. Further analysis of Kathmandu's visibility and AOD suggest profound role of background AOD on decreasing visibility. In-situ Black Carbon (BC) mass concentration measurements (BC being used as a proxy for surface observations) at two sites within Kathmandu valley have been analyzed. Kathmandu valley lacks long term trends of ambient air quality measurement data. Therefore, surface observations would be coupled with satellite measurements for understanding the urban air pollution scenario. Modelling studies to estimate the contribution of background pollution to Kathmandu's own pollution as well as the weekend effect on air quality will

  1. Napa Valley Community College District and Napa Valley College Faculty Association/CTA/NEA 1988-89 Agreement.

    ERIC Educational Resources Information Center

    Napa Valley Community Coll. District, Napa, CA.

    The collective bargaining agreement between the Board of Trustees of the Napa Valley Community College District and the Napa Valley College Faculty Association/California Teachers Association/National Education Association is presented. This contract, in effect from June 1988 through July 1989, deals with the following topics: bargaining agent…

  2. Staphylococcus aureus biofilms: recent developments in biofilm dispersal.

    PubMed

    Lister, Jessica L; Horswill, Alexander R

    2014-01-01

    Staphylococcus aureus is a major cause of nosocomial and community-acquired infections and represents a significant burden on the healthcare system. S. aureus attachment to medical implants and host tissue, and the establishment of a mature biofilm, play an important role in the persistence of chronic infections. The formation of a biofilm, and encasement of cells in a polymer-based matrix, decreases the susceptibility to antimicrobials and immune defenses, making these infections difficult to eradicate. During infection, dispersal of cells from the biofilm can result in spread to secondary sites and worsening of the infection. In this review, we discuss the current understanding of the pathways behind biofilm dispersal in S. aureus, with a focus on enzymatic and newly described broad-spectrum dispersal mechanisms. Additionally, we explore potential applications of dispersal in the treatment of biofilm-mediated infections.

  3. Channels and valleys on Mars

    NASA Technical Reports Server (NTRS)

    Baker, V. R.

    1983-01-01

    Tentative conclusions about the origins of channels and valleys on Mars based on the consensus of investigators who have studied the problem are presented. The morphology of outflow channels is described in detail, and the morphology, distribution, and genesis of Martian valleys are addressed. Secondary modification of channels and valleys by mass-wasting phenomena, eolian processes, cratering, and mantling by lava flows is discussed. The physics of the flows needed to account for the immense volumes of Martian outflow channels is considered in detail, including the possible influence of debris flows and mudflows, glaciers, and ice sheets. It is concluded that Mars once probably possessed an atmosphere with higher temperatures and pressures than at present which played an essential role in an active hydrological cycle.

  4. 36 CFR 7.26 - Death Valley National Monument.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Death Valley National... 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...

  5. NNSS Soils Monitoring: Plutonium Valley (CAU 366) FY2015

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nikolich, George; Mizell, Steve; McCurdy, Greg

    Desert Research Institute (DRI) is conducting a field assessment of the potential for contaminated soil transport from the Plutonium Valley Contamination Area (CA) as a result of wind transport and storm runoff in support of National Nuclear Security Administration (NNSA) efforts to complete regulatory closure of the contamination areas. The DRI work is intended to confirm the likely mechanism(s) of transport and determine the meteorological conditions that might cause movement of contaminated soils. The emphasis of the work is on collecting sediment transported by channelized storm runoff at the Plutonium Valley investigation sites. These data will inform closure plans thatmore » are being developed, which will facilitate the appropriate closure design and post-closure monitoring. In 2011, DRI installed two meteorological monitoring stations south (station #1) and north (station #2) of the Plutonium Valley CA and a runoff sediment sampling station within the CA. Temperature, wind speed, wind direction, relative humidity, precipitation, solar radiation, barometric pressure, soil temperature, and airborne particulate concentration are collected at both meteorological stations. The maximum, minimum, and average or total (as appropriate) for each of these parameters are recorded for each 10-minute interval. The sediment sampling station includes an automatically activated ISCO sampling pump with collection bottles for suspended sediment, which is activated when sufficient flow is present in the channel, and passive traps for bedload material that is transported down the channel during runoff events. This report presents data collected from these stations during fiscal year (FY) 2015.« less

  6. Primary State Formation in the Virú Valley, North Coast of Peru

    PubMed Central

    Millaire, Jean-François

    2010-01-01

    The origins of urban life and functioning states are two of the most fascinating research problems in anthropological archeology and a topic that has intrigued generations of scholars working on the Peruvian north coast. In this region, Andeanists have documented the rise of Moche as a dominant culture during the first millennium A.D., and the emergence of urban life and stately institutions at this society’s principal center. Although there is a broad consensus that Moche represents an archaic state, it is still unclear whether it is an example of primary state formation or a case of a second-generation state. To document this question, archaeological excavations were recently carried out at the Gallinazo Group site in the Virú Valley. Results from a radiocarbon dating program indicate that a functioning state probably emerged in this valley during the second century B.C., possibly preceding Moche by a few centuries. These results necessarily raise question regarding the nature of state development on the north coast of Peru and, in particular, whether there was a single center of state development in this region or multiple sites where similar conditions and processes led to the parallel emergence of functioning states. PMID:20308574

  7. Total carbon and nitrogen in mineral soil after 26 years of prescribed fire: Long Valley and Fort Valley Experimental Forests

    Treesearch

    Daniel G. Neary; Sally M. Haase; Steven T. Overby

    2008-01-01

    Prescribed fire was introduced to high density ponderosa pine stands at Fort Valley and Long Valley Experimental Forests in 1976. This paper reports on mineral soil total carbon (C) and nitrogen (N) at Long Valley. Total soil C and N levels were highly variable and exhibited an increasing, but inconsistent, concentration trend related to burn interval. Total N ranged...

  8. Establishing a range-wide provenance test in valley oak (Quercus lobata Née) at two California sites

    Treesearch

    Annette Delfino-Mix; Jessica W. Wright; Paul F. Gugger; Christina Liang; Victoria L. Sork

    2015-01-01

    We present the methods used to establish a provenance test in valley oak, Quercus lobata. Nearly 11,000 acorns were planted and 88 percent of those germinated. The resulting seedlings were measured after 1 and 2 years of growth, and were outplanted in the field in the winter of 2014-2015. This test represents a long-term resource for both research...

  9. Broadening our approaches to studying dispersal in raptors

    USGS Publications Warehouse

    Morrison, J.L.; Wood, P.B.

    2009-01-01

    Dispersal is a behavioral process having consequences for individual fitness and population dynamics. Recent advances in technology have spawned new theoretical examinations and empirical studies of the dispersal process in birds, providing opportunities for examining how this information may be applied to studies of the dispersal process in raptors. Many raptors are the focus of conservation efforts; thus, reliable data on all aspects of a species' population dynamics, including dispersal distances, movement rates, and mortality rates of dispersers, are required for population viability analyses that are increasingly used to inform management. Here, we address emerging issues and novel approaches used in the study of avian dispersal, and provide suggestions to consider when developing and implementing studies of dispersal in raptors. Clarifying study objectives is essential for selection of an appropriate methodology and sample size needed to obtain accurate estimates of movement distances and rates. Identifying an appropriate study-area size will allow investigators to avoid underestimating population connectivity and important population parameters. Because nomadic individuals of some species use temporary settling areas or home ranges before breeding, identification of these areas is critical for conservation efforts focusing on habitats other than breeding sites. Study designs for investigating raptor dispersal also should include analysis of environmental and social factors influencing dispersal, to improve our understanding of condition-dependent dispersal strategies. Finally, we propose a terminology for use in describing the variety of movements associated with dispersal behavior in raptors, and we suggest this terminology could be used consistently to facilitate comparisons among studies. ?? 2009 The Raptor Research Foundation, Inc.

  10. Valley-polarized quantum transport generated by gauge fields in graphene

    NASA Astrophysics Data System (ADS)

    Settnes, Mikkel; Garcia, Jose H.; Roche, Stephan

    2017-09-01

    We report on the possibility to simultaneously generate in graphene a bulk valley-polarized dissipative transport and a quantum valley Hall effect by combining strain-induced gauge fields and real magnetic fields. Such unique phenomenon results from a ‘resonance/anti-resonance’ effect driven by the superposition/cancellation of superimposed gauge fields which differently affect time reversal symmetry. The onset of a valley-polarized Hall current concomitant to a dissipative valley-polarized current flow in the opposite valley is revealed by a {{e}2}/h Hall conductivity plateau. We employ efficient linear scaling Kubo transport methods combined with a valley projection scheme to access valley-dependent conductivities and show that the results are robust against disorder.

  11. Extensive deep-sea dispersal of postlarval shrimp from a hydrothermal vent

    NASA Astrophysics Data System (ADS)

    Herring, P. J.; Dixon, D. R.

    1998-12-01

    Hydrothermal vent fields on the Mid-Atlantic Ridge (MAR) are small (no more than 0.1-1.0 km 2) and widely spaced (a reported average of one field per 175 km between 11°N and 40°N). Their faunas are similar and usually dominated by shrimp of the family Bresiliidae. Little is known about the way these animals (and other members of the vent fauna) disperse and colonize new vents. Vent shrimp juveniles have been taken close to certain vent sites, and in midwater, but their larvae and postlarvae have not been captured. We report here that bresiliid shrimp postlarvae are very widely dispersed around the Broken Spur vent field and extend into the next MAR segment and the Atlantis Fracture Zone beyond. The populations show density gradients declining both vertically and horizontally from the vent site, in contrast to the overall pelagic biomass. This is the furthest recorded dispersal (>100 km) of identified larvae from a hydrothermal vent and is sufficient to give them access to adjacent vent fields and thus the scope for colonising new sites.

  12. Groundwater availability of the Central Valley Aquifer, California

    USGS Publications Warehouse

    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. Valley-selective optical Stark effect in monolayer WS2

    NASA Astrophysics Data System (ADS)

    Gedik, Nuh

    Monolayer semiconducting transition-metal dichalcogenides (TMDs) have a pair of valleys that, by time-reversal symmetry, are energetically degenerate. Lifting the valley degeneracy in these materials is of great interest because it would allow for valley specific band engineering and offer additional control in valleytronic applications. In this talk, I will show that circularly polarized light, which breaks time-reversal symmetry, can be used to lift the valley degeneracy by means of the optical Stark effect. We demonstrate that this effect is capable of raising the exciton level in monolayer TMD WS2 by as much as 18 meV in a controllable valley-selective manner. The resulting energy shift is extremely large, comparable to the shift that would be obtained using a very high magnetic field (approximately 100 Tesla). These results offer a novel way to control valley degree of freedom, and may provide a means to realize new valley-selective Floquet topological state of matter.

  14. Selected examples of dispersal of arthropods associated with agricultural crop and animal production

    NASA Technical Reports Server (NTRS)

    Henneberry, T. J.

    1979-01-01

    The economic importance of arthropods in agricultural production systems and the possibilities of using dispersal behavior to develop and manipulate control are examined. Examples of long and short distance dispersal of economic insect pests and beneficial species from cool season host reservoirs and overwintering sites are presented. Significant dispersal of these species often occurring during crop and animal production is discussed.

  15. Archaeohydrological studies in the Sárvíz valley (Hungary) using high-resolution LiDAR data

    NASA Astrophysics Data System (ADS)

    Pacskó, Vivien; Székely, Balázs; Stibrányi, Máté; Koma, Zsófia

    2015-04-01

    The central area of the Pannonian basin encompasses mostly low-relief areas. Its south-western part, the southern Transdanubian hilly areas have characteristic NNW-SSE directional pattern. One of the largest valleys is a conspicuously straight valley section of the River Sárvíz between Székesfehérvár and Szekszárd. The river collects the waters of eastern Bakony Mountains takes its rise in Sárrét, in its natural condition originally a marshland, and flows into the river Sió towards the River Danube. The studied valley section is characterised by low relief, in the west it is bordered by a scarp with incised tributaries whereas the eastern side is less sharp. Its hydrological characteristics was artificially changed to due to river regulation in the 19th century in order to change the swampy character of the valley that was previously typical earlier (Sárvíz means muddy water). The area shows various settlement remains since the Neolithic, and characteristic spatial patterns have been found in ages of archaeological features and settlement sites, we assumed that the settlement pattern might have been influenced by the various water levels. To prove the changes in hydrological setting we can also use medieval written sources which makes us able to identify some of the former lakes and watercourse segments of the river at a surprising detail. Consequently, this research is aimed to detect the original features and the paleohydrological changes by collecting data on archaeological site locations and compare them to the fine elevation pattern of the sites. In order to derive the elevations of the identified sites LiDAR data acquisition has been carried out in the framework of the EUFAR project supported by the European Union. The weather conditions were not optimal for the measurements, so we paid special attention to the processing of the resulting point cloud to create a high-resolution, high-accuracy digital terrain model (DTM). The data have been

  16. Estimating Strain Accumulation in the New Madrid and Wabash Valley Seismic Zones

    NASA Astrophysics Data System (ADS)

    Craig, T. J.; Calais, E.

    2014-12-01

    The mechanical behaviour -- and hence earthquake potential -- of faults in continental interiors is a question of critical importance for the resultant seismic hazard, but no consensus has yet been reached on this controversial topic. The debate has focused on the central and eastern United States, in particular the New Madrid Seismic Zone, struck by three magnitude 7 or greater earthquakes in 1811--1812, and to a lesser extent the Wabash Valley Seismic Zone just to the north. A key aspect of this issue is the rate at which strain is currently accruing on those faults in the plate interior, a quantity that remains debated. Understanding if the present-day strain rates indicate sufficient motion to account for the historical and paleoseismological earthquakes by steady-state fault behaviour, or if strain accumulation is time-dependent in this area, is critical for investigating the causative process driving this seismicity in the plate interior, and how regional strain reflects the interplay between stresses arising from different geological processes. Here we address this issue with an analysis of up to 14 years of continuous GPS data from a network of 200 sites in the central United States centred on the New Madrid and Wabash Valley seismic zones. We find that high-quality sites in these regions show motions that are consistently within the 95% confidence limit of zero deformation relative to a rigid background. These results place an upper bound on regional strain accrual of 0.2 mm/yr and 0.5 mm/yr in the New Madrid and Wabash Valley Seismic Zones, respectively. These results, together with increasing evidence for temporal clustering and spatial migration of earthquake sequences in continental interiors, indicate that either tectonic loading rates or fault properties vary with time in the NMSZ and possibly plate-wide.

  17. Guidelines for model calibration and application to flow simulation in the Death Valley regional groundwater system

    USGS Publications Warehouse

    Hill, M.C.; D'Agnese, F. A.; Faunt, C.C.

    2000-01-01

    Fourteen guidelines are described which are intended to produce calibrated groundwater models likely to represent the associated real systems more accurately than typically used methods. The 14 guidelines are discussed in the context of the calibration of a regional groundwater flow model of the Death Valley region in the southwestern United States. This groundwater flow system contains two sites of national significance from which the subsurface transport of contaminants could be or is of concern: Yucca Mountain, which is the potential site of the United States high-level nuclear-waste disposal; and the Nevada Test Site, which contains a number of underground nuclear-testing locations. This application of the guidelines demonstrates how they may be used for model calibration and evaluation, and also to direct further model development and data collection.Fourteen guidelines are described which are intended to produce calibrated groundwater models likely to represent the associated real systems more accurately than typically used methods. The 14 guidelines are discussed in the context of the calibration of a regional groundwater flow model of the Death Valley region in the southwestern United States. This groundwater flow system contains two sites of national significance from which the subsurface transport of contaminants could be or is of concern: Yucca Mountain, which is the potential site of the United States high-level nuclear-waste disposal; and the Nevada Test Site, which contains a number of underground nuclear-testing locations. This application of the guidelines demonstrates how they may be used for model calibration and evaluation, and also to direct further model development and data collection.

  18. Groundwater quality in the Santa Clara River Valley, California

    USGS Publications Warehouse

    Burton, Carmen A.; Landon, Matthew K.; Belitz, Kenneth

    2011-01-01

    The Santa Clara River Valley (SCRV) study unit is located in Los Angeles and Ventura Counties, California, and is bounded by the Santa Monica, San Gabriel, Topatopa, and Santa Ynez Mountains, and the Pacific Ocean. The 460-square-mile study unit includes eight groundwater basins: Ojai Valley, Upper Ojai Valley, Ventura River Valley, Santa Clara River Valley, Pleasant Valley, Arroyo Santa Rosa Valley, Las Posas Valley, and Simi Valley (California Department of Water Resources, 2003; Montrella and Belitz, 2009). The SCRV study unit has hot, dry summers and cool, moist winters. Average annual rainfall ranges from 12 to 28 inches. The study unit is drained by the Ventura and Santa Clara Rivers, and Calleguas Creek. The primary aquifer system in the Ventura River Valley, Ojai Valley, Upper Ojai Valley, and Simi Valley basins is largely unconfined alluvium. The primary aquifer system in the remaining groundwater basins mainly consists of unconfined sands and gravels in the upper portion and partially confined marine and nonmarine deposits in the lower portion. The primary aquifer system in the SCRV study unit is defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health (CDPH) database. Public-supply wells typically are completed in the primary aquifer system to depths of 200 to 1,100 feet below land surface (bls). The wells contain solid casing reaching from the land surface to a depth of about 60-700 feet, and are perforated below the solid casing to allow water into the well. Water quality in the primary aquifer system may differ from the water in the shallower and deeper parts of the aquifer. Land use in the study unit is approximately 40 percent (%) natural (primarily shrubs, grassland, and wetlands), 37% agricultural, and 23% urban. The primary crops are citrus, avocados, alfalfa, pasture, strawberries, and dry beans. The largest urban areas in the study unit are the cities of

  19. The Salzach Valley overdeeping: A most precise bedrock model of a major alpine glacial basin

    NASA Astrophysics Data System (ADS)

    Pomper, Johannes; Salcher, Bernhard; Eichkitz, Christoph

    2016-04-01

    sedimentary succession, representing multiple cycles of massive gravels and lacustrine fines, indicate that the valley was not fully excavated during the last glacial coverage at the LGM. Through its model accuracy related to a comprehensive geodatabase and a relatively homogenous rock erodibility, the Salzach Valley overdeepening might be a highly suitable testing site for future numerical simulations.

  20. Catalyst Architecture for Stable Single Atom Dispersion Enables Site-Specific Spectroscopic and Reactivity Measurements of CO Adsorbed to Pt Atoms, Oxidized Pt Clusters, and Metallic Pt Clusters on TiO2.

    PubMed

    DeRita, Leo; Dai, Sheng; Lopez-Zepeda, Kimberly; Pham, Nicholas; Graham, George W; Pan, Xiaoqing; Christopher, Phillip

    2017-10-11

    Oxide-supported precious metal nanoparticles are widely used industrial catalysts. Due to expense and rarity, developing synthetic protocols that reduce precious metal nanoparticle size and stabilize dispersed species is essential. Supported atomically dispersed, single precious metal atoms represent the most efficient metal utilization geometry, although debate regarding the catalytic activity of supported single precious atom species has arisen from difficulty in synthesizing homogeneous and stable single atom dispersions, and a lack of site-specific characterization approaches. We propose a catalyst architecture and characterization approach to overcome these limitations, by depositing ∼1 precious metal atom per support particle and characterizing structures by correlating scanning transmission electron microscopy imaging and CO probe molecule infrared spectroscopy. This is demonstrated for Pt supported on anatase TiO 2 . In these structures, isolated Pt atoms, Pt iso , remain stable through various conditions, and spectroscopic evidence suggests Pt iso species exist in homogeneous local environments. Comparing Pt iso to ∼1 nm preoxidized (Pt ox ) and prereduced (Pt metal ) Pt clusters on TiO 2 , we identify unique spectroscopic signatures of CO bound to each site and find CO adsorption energy is ordered: Pt iso ≪ Pt metal < Pt ox . Pt iso species exhibited a 2-fold greater turnover frequency for CO oxidation than 1 nm Pt metal clusters but share an identical reaction mechanism. We propose the active catalytic sites are cationic interfacial Pt atoms bonded to TiO 2 and that Pt iso exhibits optimal reactivity because every atom is exposed for catalysis and forms an interfacial site with TiO 2 . This approach should be generally useful for studying the behavior of supported precious metal atoms.

  1. Bird use of reforestation sites: Influence of location and vertical structure

    USGS Publications Warehouse

    Twedt, Daniel J.; Cooper, Robert

    2005-01-01

    In the Lower Mississippi Valley, more than 300,000 acres of agricultural land have been reforested in the last 10 years. Planning decisions on how and where to restore forest are complex and usually reflect landowner objectives. However, initial planning decisions may have a large influence on the value of restored stands for birds and other wildlife.Reforestation of small, isolated tracts will likely result in mature forests where reproductive output of breeding birds does not compensate for adult mortality (sink habitats). This may be due to factors such as lower reproductive success near edges (edge effects), insufficient area of habitat to attract colonizing birds (area effects), or restricted population mixing and mating opportunities because of limited dispersal among tracts (isolation effects).Conversely, reforestation adjacent to existing forest increases contiguous forest area and provides areas buffered from agricultural or urban habitats (interior forest core).Bottomland reforestation has historically focused on planting relatively slow-growing tree species, particularly oaks (Quercus spp.). Thus, restoration sites are often dominated by grasses and forbs for up to a decade after tree planting. Grassland birds are the first birds to colonize reforested sites. However, abundance and productivity of grassland birds is generally poor on sites associated with woody vegetation, such as sites adjacent to mature forest.As woody vegetation develops on reforested sites, birds preferring shrub-scrub habitat displace grassland species (Twedt et al. 2002) (fig. 1). Planting faster-growing trees compresses the time for colonization by shrub-scrub birds and the increased vertical stature of these trees attracts forest birds (Twedt and Portwood 1996). Additionally, planting next to existing mature forests creates transitional edges that reduce the detrimental effects of abrupt forest-agriculture interfaces.

  2. Population genetic evidence for sex-specific dispersal in an inbred social spider.

    PubMed

    Smith, Deborah R; Su, Yong-Chao; Berger-Tal, Reut; Lubin, Yael

    2016-08-01

    Dispersal in most group-living species ensures gene flow among groups, but in cooperative social spiders, juvenile dispersal is suppressed and colonies are highly inbred. It has been suggested that such inbred sociality is advantageous in the short term, but likely to lead to extinction or reduced speciation rates in the long run. In this situation, very low levels of dispersal and gene flow among colonies may have unusually important impacts on fitness and persistence of social spiders. We investigated sex-specific differences in dispersal and gene flow among colonies, as reflected in the genetic structure within colonies and populations of the African social spider Stegodyphus dumicola Pocock, 1898 (Eresidae). We used DNA fingerprinting and mtDNA sequence data along with spatial mapping of colonies to compare male and female patterns of relatedness within and among colonies at three study sites. Samples were collected during and shortly after the mating season to detect sex-specific dispersal. Distribution of mtDNA haplotypes was consistent with proliferation of social nests by budding and medium- to long-distance dispersal by ballooning females. Analysis of molecular variance and spatial autocorrelation analyses of AFLPs showed high levels of genetic similarity within colonies, and STRUCTURE analyses revealed that the number of source populations contributing to colonies ranged from one to three. We also showed significant evidence of male dispersal among colonies at one site. These results support the hypothesis that in social spiders, genetic cohesion among populations is maintained by long-distance dispersal of female colony founders. Genetic diversity within colonies is maintained by colony initiation by multiple dispersing females, and adult male dispersal over short distances. Male dispersal may be particularly important in maintaining gene flow among colonies in local populations.

  3. Revisiting Pearson's climate and forest type studies on the Fort Valley Experimental Forest (P-53)

    Treesearch

    Joseph E. Crouse; Margaret M. Moore; Peter Z. Fule

    2008-01-01

    Five weather station sites were established in 1916 by Fort Valley personnel along an elevational gradient from the Experimental Station to near the top of the San Francisco Peaks to investigate the factors that controlled and limited forest types. The stations were located in the ponderosa pine, Douglas-fir, limber pine, Engelmann spruce, and Engelmann spruce/...

  4. Effect of Acorn Planting Depth on Depredation, Emergence, and Survival of Valley and Blue Oak

    Treesearch

    William D. Tietje; Sherryl L. Nives; Jennifer A. Honig; William H. Weitkamp

    1991-01-01

    During 1989 in east-central San Luis Obispo County, California, we studied the relationship of valley oak (Quercus lobata) and blue oak (Q. douglasii) acorn planting depth and number of acorns per planting site to acorn depredation, seedling emergence, survival, and height. Acorns were planted at three depths (1.3, 5.1, and 10.2 cm...

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

    USGS Publications Warehouse

    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.

  6. Impact of atmospheric boundary layer depth variability and wind reversal on the diurnal variability of aerosol concentration at a valley site.

    PubMed

    Pal, S; Lee, T R; Phelps, S; De Wekker, S F J

    2014-10-15

    The development of the atmospheric boundary layer (ABL) plays a key role in affecting the variability of atmospheric constituents such as aerosols, greenhouse gases, water vapor, and ozone. In general, the concentration of any tracers within the ABL varies due to the changes in the mixing volume (i.e. ABL depth). In this study, we investigate the impact on the near-surface aerosol concentration in a valley site of 1) the boundary layer dilution due to vertical mixing and 2) changes in the wind patterns. We use a data set obtained during a 10-day field campaign in which a number of remote sensing and in-situ instruments were deployed, including a ground-based aerosol lidar system for monitoring of the ABL top height (zi), a particle counter to determine the number concentration of aerosol particles at eight different size ranges, and tower-based standard meteorological instruments. Results show a clearly visible decreasing trend of the mean daytime zi from 2900 m AGL (above ground level) to 2200 m AGL during a three-day period which resulted in increased near-surface pollutant concentrations. An inverse relationship exists between the zi and the fine fraction (0.3-0.7 μm) accumulation mode particles (AMP) on some days due to the dilution effect in a well-mixed ABL. These days are characterized by the absence of daytime upvalley winds and the presence of northwesterly synoptic-driven winds. In contrast, on the days with an onset of an upvalley wind circulation after the morning transition, the wind-driven local transport mechanism outweighs the ABL-dilution effect in determining the variability of AMP concentration. The interplay between the ABL depth evolution and the onset of the upvalley wind during the morning transition period significantly governs the air quality in a valley and could be an important component in the studies of mountain meteorology and air quality. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Bibliography of literature pertaining to Long Valley Caldera and associated volcanic fields

    USGS Publications Warehouse

    Ewert, John W.; Harpel, Christopher J.; Brooks, Suzanna K.; Marcaida, Mae

    2011-01-01

    define the beginning of the Brunhes Chron and helps constrain the Brunhes-Matuyama boundary. The Bishop ash, which was dispersed as far east as Nebraska, Kansas, and Texas, provides an important tephrostratigraphic marker throughout the Western United States. The obsidian domes of both the Mono and Inyo Craters, which were produced by rhyolitic eruptions in the past 40,000 years, have been well studied, including extensive scientific drilling through the domes. Exploratory drilling to 3-km depth on the resurgent dome and subsequent instrumentation of the Long Valley Exploratory Well (LVEW) have led to a number of important new insights. Scientific drilling also has been done within the Casa Diablo geothermal field, which, aside from drilling, has been commercially developed and is currently feeding 40 MW of power into the Southern California Edison grid. Studies in all the above-mentioned volcanic fields have contributed to the extensive scientific literature published on the Long Valley region. Although most of this scientific literature has been published since 1970, a significant amount of historical literature extends backward to the late 1800s. The purpose of this bibliography is to compile references pertaining to the Long Valley region from all time periods and all Earth science fields into a single listing, thus providing an easily accessible guide to the published literature for current and future researchers.

  8. Prevalence and distribution of pox-like lesions, avian malaria, and mosquito vectors in Kipahulu valley, Haleakala National Park, Hawai'i, USA

    USGS Publications Warehouse

    Aruch, Samuel; Atkinson, Carter T.; Savage, Amy F.; LaPointe, Dennis

    2007-01-01

    We determined prevalence and altitudinal distribution of introduced avian malarial infections (Plasmodium relictum) and pox-like lesions (Avipoxvirus) in forest birds from Kīpahulu Valley, Haleakalā National Park, on the island of Maui, and we identified primary larval habitat for the mosquito vector of this disease. This intensively managed wilderness area and scientific reserve is one of the most pristine areas of native forest remaining in the state of Hawai‘i, and it will become increasingly important as a site for restoration and recovery of endangered forest birds. Overall prevalence of malarial infections in the valley was 8% (11/133) in native species and 4% (4/101) in nonnative passerines; prevalence was lower than reported for comparable elevations and habitats elsewhere in the state. Infections occurred primarily in ‘Apapane (Himatione sanguinea) and Hawai‘i ‘Amakihi (Hemignathus virens) at elevations below 1,400 m. Pox-like lesions were detected in only two Hawai‘i ‘Amakihi (2%; 2/94) at elevations below 950 m. We did not detect malaria or pox in birds caught at 1,400 m in upper reaches of the valley. Adult mosquitoes (Culex quinquefasciatus) were captured at four sites at elevations of 640, 760, 915, and 975 m, respectively. Culex quinquefasciatus larvae were found only in rock holes along intermittent tributaries of the two largest streams in the valley, but not in standing surface water, pig wallows, ground pools, tree cavities, and tree fern cavities. Mosquito populations in the valley are low, and they are probably influenced by periods of high rainfall that flush stream systems.

  9. Large-Scale Land Development, Fugitive Dust, and Increased Coccidioidomycosis Incidence in the Antelope Valley of California, 1999-2014.

    PubMed

    Colson, Aaron J; Vredenburgh, Larry; Guevara, Ramon E; Rangel, Natalia P; Kloock, Carl T; Lauer, Antje

    2017-06-01

    Ongoing large-scale land development for renewable energy projects in the Antelope Valley, located in the Western Mojave Desert, has been blamed for increased fugitive dust emissions and coccidioidomycosis incidence among the general public in recent years. Soil samples were collected at six sites that were destined for solar farm construction and were analyzed for the presence of the soil-borne fungal pathogen Coccidioides immitis which is endemic to many areas of central and southern California. We used a modified culture-independent nested PCR approach to identify the pathogen in all soil samples and also compared the sampling sites in regard to soil physical and chemical parameters, degree of disturbance, and vegetation. Our results indicated the presence of C. immitis at four of the six sites, predominantly in non-disturbed soils of the Pond-Oban complex, which are characterized by an elevated pH and salt bush communities, but also in grassland characterized by different soil parameters and covered with native and non-native annuals. Overall, we were able to detect the pathogen in 40% of the soil samples (n = 42). Incidence of coccidioidomycosis in the Antelope Valley was positively correlated with land use and particulate matter in the air (PM10) (Pearson correlation coefficient >0.5). With the predicted population growth and ongoing large-scale disturbance of soil in the Antelope Valley in coming years, incidence of coccidioidomycosis will likely further increase if policy makers and land developers continue to ignore the risk of grading land without implementing long-term dust mitigation plans in Environmental Impact Reports.

  10. Geology of the Greenwater Range, and the dawn of Death Valley, California—Field guide for the Death Valley Natural History Conference, 2013

    USGS Publications Warehouse

    Calzia, J.P.; Rämö, O.T.; Jachens, Robert; Smith, Eugene; Knott, Jeffrey

    2016-05-02

    Much has been written about the age and formation of Death Valley, but that is one—if not the last—chapter in the fascinating geologic history of this area. Igneous and sedimentary rocks in the Greenwater Range, one mountain range east of Death Valley, tell an earlier story that overlaps with the formation of Death Valley proper. This early story has been told by scientists who have studied these rocks for many years and continue to do so. This field guide was prepared for the first Death Valley Natural History Conference and provides an overview of the geology of the Greenwater Range and the early history (10–0 Ma) of Death Valley.

  11. Variation in Time of Flowering and Seed Dispersal of Eastern Cottonwood In the Lower Mississippi Valley

    Treesearch

    Robert E. Farmer

    1966-01-01

    Flowering of Populus deItoides Bartr. occurred from early March to early April; differences between trees within stands accounted for 98 percent of the significant variation in dates. High correlation (r = .91 to .96) between 1963 and 1964 dates of individual trees indicated that trees within stands flower in a predictable sequence. Seed dispersal...

  12. 27 CFR 9.191 - Ramona Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Ramona Valley. 9.191 Section 9.191 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT...) Borrego Valley, California, 1982 edition; and (2) El Cajon, California, 1979 edition. (c) Boundary. The...

  13. 27 CFR 9.191 - Ramona Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Ramona Valley. 9.191 Section 9.191 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT...) Borrego Valley, California, 1982 edition; and (2) El Cajon, California, 1979 edition. (c) Boundary. The...

  14. A Quantitative Analysis of the Fretted Terrain Valleys, Arabia Terra, Mars

    NASA Astrophysics Data System (ADS)

    Mason, Kelsey Anne

    Fretted terrain describes regions on Mars with low-lying, flat valleys separated by steep cliffs that often form polygonal-shaped mesas. The fretted terrain valleys have a morphology distinct from other valleys found on Mars, and their unknown origin may hold insights into critical questions about Mars' tectonic, magmatic, and hydrologic history. Current hypothesis for the formation of the fretted terrain include fracturing as well as hydrological flow processes such as fluvial or glacial erosion. The region for this study is located in eastern Arabia Terra and is the type-location for fretted terrain. By qualitatively and quantitatively documenting the planform, or map-view, valley geometries and orientations throughout the fretted terrain, this study better constrains the origin of the valleys. Valleys were mapped using automated routines in ArcGIS including the D8 flow direction algorithm. Valleys were then grouped geographically into basins and also by Strahler order. The valleys were then segmented every 50 km and the azimuth of each segment was calculated. The resulting valley azimuths were analyzed using rose diagrams to quantitatively describe the planform geometries of the valleys. Qualitatively, the majority of basins were found to have rectangular valley geometries. The downslope direction was calculated for each basin, and it was compared to the corresponding valley azimuths. The basins with rectangular valley geometries had valleys with an azimuth mode nearly parallel to the downslope direction and another azimuth mode perpendicular to the downslope direction. The valley azimuth mode parallel to the downslope direction is attributed to hydrological flow processes while the mode perpendicular to the downslope direction is attributed to fracturing related to the formation or existence of the Mars global dichotomy boundary.

  15. The potential impact of green agendas on historic river landscapes: Numerical modelling of multiple weir removal in the Derwent Valley Mills world heritage site, UK

    NASA Astrophysics Data System (ADS)

    Howard, A. J.; Coulthard, T. J.; Knight, D.

    2017-09-01

    The exploitation of river systems for power and navigation has commonly been achieved through the installation of a variety of in-channel obstacles of which weirs in Britain are amongst the most common. In the UK, the historic value of many of these features is recognised by planning designations and protection more commonly associated with historic buildings and other major monuments. Their construction, particularly in the north and west of Britain, has often been associated with industries such as textiles, chemicals, and mining, which have polluted waterways with heavy metals and other contaminants. The construction of weirs altered local channel gradients resulting in sedimentation upstream with the potential as well for elevated levels of contamination in sediments deposited there. For centuries these weirs have remained largely undisturbed, but as a result of the growth in hydropower and the drive to improve water quality under the European Union's Water Framework Directive, these structures are under increasing pressure to be modified or removed altogether. At present, weir modifications appear to be considered largely on an individual basis, with little focus on the wider impacts this might have on valley floor environments. Using a numerical modelling approach, this paper simulates the removal of major weirs along a 24-km stretch of the river Derwent, Derbyshire, UK, designated as a UNESCO World Heritage Site. The results suggest that although removal would not result in significant changes to the valley morphology, localised erosion would occur upstream of structures as the river readjusts its base level to new boundary conditions. Modelling indicates that sediment would also be evacuated away from the study area. In the context of the Derwent valley, this raises the potential for the remobilisation of contaminants (legacy sediments) within the wider floodplain system, which could have detrimental, long-term health and environmental implications for the

  16. Dynamics of valley pseudospin in single-layer WSe2. Inter-valley scattering mediated by electron-phonon interaction

    NASA Astrophysics Data System (ADS)

    Molina-Sanchez, Alejandro; Sangalli, Davide; Wirtz, Ludger; Marini, Andrea

    In a time-dependent Kerr experiment a circularly polarized laser field is used to selectively populate the K+/- electronic valleys of single-layer WSe2. This carrier population corresponds to a finite pseudospin polarization that dictates the valleytronic properties of WSe2, but whose decay mechanism still remains largely debated. Time-dependent Kerr experiments provide an accurate way to visualize the pseudospin dynamics by measuring the rotation of a linearly polarized probe pulse applied after a circularly polarized and short pump pulse. We present here a clear, accurate and parameter-free description of the valley pseudospin dynamics in single-layer WSe2. By using an ab-initio approach we solve unambiguously the long standing debate about the dominant mechanism that drives the valley depolarization. Our results are in excellent agreement with recent time-dependent Kerr experiments. The decay dynamics and peculiar temperature dependence is explained in terms of electron phonon mediated processes that induce spin-flip inter-valley transitions.

  17. Can non-breeding be a cost of breeding dispersal?

    USGS Publications Warehouse

    Danchin, E.; Cam, E.

    2002-01-01

    Breeding habitat selection and dispersal are crucial processes that affect many components of fitness. Breeding dispersal entails costs, one of which has been neglected: dispersing animals may miss breeding opportunities because breeding dispersal requires finding a new nesting site and mate, two time- and energy-consuming activities. Dispersers are expected to be prone to non-breeding. We used the kittiwake (Rissa tridactyla) to test whether breeding dispersal influences breeding probability. Breeding probability was associated with dispersal, in that both were negatively influenced by private information (previous individual reproductive success) and public information (average reproductive success of conspecifics) about patch quality. Furthermore, the probability of skipping breeding was 1.7 times higher in birds that settled in a new patch relative to those that remained on the same patch. Finally, non-breeders that resumed breeding were 4.4 times more likely to disperse than birds that bred in successive years. Although private information may influence breeding probability directly, the link between breeding probability and public information may be indirect, through the influence of public information on breeding dispersal, non-breeding thus being a cost of dispersal. These results support the hypothesis that dispersal may result in not being able to breed. More generally, non-breeding (which can be interpreted as an extreme form of breeding failure) may reveal costs of various previous activities. Because monitoring the non-breeding portion of a population is difficult, non-breeders have been neglected in many studies of reproduction trade-offs.

  18. Factors affecting dispersion of backcountry campsites

    Treesearch

    Lance Kirkpatrick Canon; Steven Adler; Raymond E. Leonard

    1979-01-01

    A study using observational and survey techniques found that no backcountry users fully complied with rules designed to promote campsite dispersion and to avoid recurrent use of particular sites. Users perceived hiking/camping in general, and movement away from established trails in particular, as involving an element of risk. They indicated that convenience was an...

  19. M-X Environmental Technical Report. Alternative Potential Operating Base Locations, Coyote Spring Valley.

    DTIC Science & Technology

    1980-12-22

    necessary and identify by block number) MX Coyote Spring, Nevada Siting Analysis Nevada Environnental Report 20. ABSTRACT (Continue on reverse side If...necessary and Identify by block number) The area of analysis (AO) for the Coyote Spring Valley operating base option includes both Clark and Lincoln...counties, and is located in the southern portion of the designated region of influence. Las Vegas and the surrounding suburbs are the major settlements and

  20. Scaling relationships and concavity of small valley networks on Mars

    NASA Astrophysics Data System (ADS)

    Penido, Julita C.; Fassett, Caleb I.; Som, Sanjoy M.

    2013-01-01

    Valley networks are widely interpreted as the preserved erosional record of water flowing across the martian surface. The manner in which valley morphometric properties scale with drainage area has been widely examined on Earth. Earlier studies assessing these properties on Mars have suggested that martian valleys are morphometrically distinct from those on Earth. However, these earlier measurements were generally made on large valley systems because of the limited topographic data available. In this study, we determine the scaling properties of valley networks at smaller scales than have been previously assessed, using digital elevation models from the High Resolution Stereo Camera (HRSC). We find a Hack's law exponent of 0.74, larger than on Earth, and our measurements also reveal that individual small valleys have concave up, concave down, and quasi-linear longitudinal profiles, consistent with earlier studies of dissected terrain on Mars. However, for many valleys, widths are observed to increase downstream similarly to how they scale in terrestrial channels. The similarities and differences between valley networks on Mars and Earth are consistent with the idea that valleys on Mars are comparatively immature, and precipitation was a likely mechanism for delivering water to these networks.