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Sample records for arroyo pergamino provincia

  1. VIEW OF ARROYO SECO CHANNEL PEDESTRIAN FOOTBRIDGE LOCATED IN ARROYO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF ARROYO SECO CHANNEL PEDESTRIAN FOOTBRIDGE LOCATED IN ARROYO SECO PARK, JUST SOUTH OF AVENUE 60 BRIDGE OVER THE ARROYO SECO PARKWAY. THIS BRIDGE WAS THE FIRST PRESTRESSED CONCRETE BRIDGE ERECTED WEST OF THE MISSISSIPPI WHEN IT WAS HOISTED INTO PLACE IN 1951. LOOKING 26°NNE - Arroyo Seco Channel Pedestrian Bridge, Spanning Arroyo Seco Channel south of Avenue 60, Arroyo Seco Park, Los Angeles, Los Angeles County, CA

  2. ARROYO SECO ROADLESS AREA, CALIFORNIA.

    USGS Publications Warehouse

    Powell, Robert E.; Gabby, Peter N.

    1984-01-01

    Situated in the southwestern San Gabriel Mountains in Los Angeles County, California, the Arroyo Seco Roadless Area encompasses about 8 sq mi within the Angeles National Forest. On the basis of geologic mapping, a geochemical stream-sediment survey, and a survey of mines, quarries, and prospects, the area has a probable resource potential for small gold occurrences in the southern part of the area. Sand, gravel, and stone suitable for construction materials are found in the roadless area. Because of their regional association with gold mineralization, the thin and poorly exposed mafic dikes in the Echo Granite, the Mount Lowe Granodiorite, and the Precambrian gneiss in and around the roadless area offer the most promising avenue for additional study of the resource potential of the area.

  3. ARROYO SECO PARKWAY SOUTHBOUND LANES AND EXIT RAMP TO ORANGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ARROYO SECO PARKWAY SOUTHBOUND LANES AND EXIT RAMP TO ORANGE GROVE AVENUE. ORANGE GROVE AVENUE BRIDGE IN REAR. LOOKING 278°W - Arroyo Seco Parkway, Orange Grove Avenue Bridge, Milepost 30.59, Los Angeles, Los Angeles County, CA

  4. 12. VIEW OF ARROYO SECO CHANNEL SEEN FROM SAN FERNANDO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. VIEW OF ARROYO SECO CHANNEL SEEN FROM SAN FERNANDO BRIDGE. NOTE VIADUCTS AND TUNNEL PORTAL AT REAR. LOOKING 234°SW. - Arroyo Seco Parkway, Figueroa Street Viaduct, Spanning Los Angeles River, Los Angeles, Los Angeles County, CA

  5. Processes of arroyo filling in northern New Mexico, USA

    USGS Publications Warehouse

    Friedman, Jonathan M.; Vincent, Kirk R.; Griffin, Eleanor R.; Scott, Michael L.; Shafroth, Patrick B.; Auble, Gregor T.

    2015-01-01

    We documented arroyo evolution at the tree, trench, and arroyo scales along the lower Rio Puerco and Chaco Wash in northern New Mexico, USA. We excavated 29 buried living woody plants and used burial signatures in their annual rings to date stratigraphy in four trenches across the arroyos. Then, we reconstructed the history of arroyo evolution by combining trench data with arroyo-scale information from aerial imagery, light detection and ranging (LiDAR), longitudinal profiles, and repeat surveys of cross sections. Burial signatures in annual rings of salt cedar and willow dated sedimentary beds greater than 30 cm thick with annual precision. Along both arroyos, incision occurred until the 1930s in association with extreme high flows, and subsequent filling involved vegetation development, channel narrowing, increased sinuosity, and finally vertical aggradation. A strongly depositional sediment transport regime interacted with floodplain shrubs to produce a characteristic narrow, trapezoidal channel. The 55 km study reach along the Rio Puerco demonstrated upstream progression of arroyo widening and filling, but not of arroyo incision, channel narrowing, or floodplain vegetation development. We conclude that the occurrence of upstream progression within large basins like the Rio Puerco makes precise synchrony across basins impossible. Arroyo wall retreat is now mostly limited to locations where meanders impinge on the arroyo wall, forming hairpin bends, for which entry to and exit from the wall are stationary. Average annual sediment storage within the Rio Puerco study reach between 1955 and 2005 was 4.8 × 105 t/yr, 16% of the average annual suspended sediment yield, and 24% of the long-term bedrock denudation rate. At this rate, the arroyo would fill in 310 yr.

  6. 1. ARROYO SECO FREEWAY SOUTHBOUND AT FAIR OAKS ON RAMP. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. ARROYO SECO FREEWAY SOUTHBOUND AT FAIR OAKS ON RAMP. ABANDONED RAILROAD TRESTLE AND FREMONT AVENUE BRIDGE AT REAR. LOOKING 268°W. - Arroyo Seco Parkway, Fair Oaks Avenue Bridge, Milepost 31.17, Los Angeles, Los Angeles County, CA

  7. 8. ARROYO SECO PARKWAY AND NORTH SIDE OF YORK BOULEVARD ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. ARROYO SECO PARKWAY AND NORTH SIDE OF YORK BOULEVARD BRIDGE. NOTE SUPER ELEVATED CURVES AND GRADE SEPARATION OF NORTH AND SOUTHBOUND LANES. LOOKING 196"S. - Arroyo Seco Parkway, York Boulevard Bridge, Milepost 29.50, Los Angeles, Los Angeles County, CA

  8. ARROYO SECO PARKWAY SOUTHBOUND LANES AND EXIT RAMP TO ORANGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ARROYO SECO PARKWAY SOUTHBOUND LANES AND EXIT RAMP TO ORANGE GROVE AVENUE. ORANGE GROVE AVENUE BRIDGE IN REAR. NOTE IRRIGATION AND DRAINAGE FEATURES AT RIGHT. LOOKING 248°WSW - Arroyo Seco Parkway, Orange Grove Avenue Bridge, Milepost 30.59, Los Angeles, Los Angeles County, CA

  9. 6. VIEW FROM AVENUE 26 BRIDGE OF ARROYO SECO PARKWAY. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. VIEW FROM AVENUE 26 BRIDGE OF ARROYO SECO PARKWAY. NOTE CHANGE IN ELEVATION OF SOUTHBOUND LANES TO MEET GRADE FOR ELYSIAN PARK ROAD CUT. INTERSTATE I-5 IN CENTER REAR. LOOKING 232°SW. - Arroyo Seco Parkway, Avenue 26 Bridge, Milepost 25.91, Los Angeles, Los Angeles County, CA

  10. 33 CFR 117.951 - Arroyo Colorado River.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Arroyo Colorado River. 117.951 Section 117.951 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.951 Arroyo Colorado River. The draw of...

  11. 33 CFR 117.951 - Arroyo Colorado River.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Arroyo Colorado River. 117.951 Section 117.951 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.951 Arroyo Colorado River. The draw of...

  12. 33 CFR 117.951 - Arroyo Colorado River.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Arroyo Colorado River. 117.951 Section 117.951 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.951 Arroyo Colorado River. The draw of...

  13. 33 CFR 117.951 - Arroyo Colorado River.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Arroyo Colorado River. 117.951 Section 117.951 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.951 Arroyo Colorado River. The draw of...

  14. 33 CFR 117.951 - Arroyo Colorado River.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Arroyo Colorado River. 117.951 Section 117.951 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Texas § 117.951 Arroyo Colorado River. The draw of...

  15. Tucson's Santa Cruz River and the Arroyo Legacy

    NASA Astrophysics Data System (ADS)

    Betancourt, Julio Luis

    1990-01-01

    Between 1865 and 1915, arroyos developed in the southwestern United States across diverse hydrological, ecological and cultural settings. That they developed simultaneously has encouraged the search for a common cause --some phenomenon that was equally widespread and synchronous. There are few southwestern streams for which we have even a qualitative understanding of timelines and processes involved in initiation and extension of historic arroyos. Tucson's Santa Cruz River, often cited in the arroyo literature, offers a unique opportunity to chronicle the arroyo legacy and evaluate its causes. The present study reconstructs both the physical and cultural circumstances of channel entrenchment along the Santa Cruz River. Primary data include newspaper accounts, notes and plants of General Land Office surveys, eyewitness accounts, legal depositions, and repeat photography. On the Santa Cruz River, arroyo initiation and extension happened during relatively wet decades associated with frequent warm episodes in the tropical Pacific (El Nino conditions). Intensified El Nino activity during the period 1864-1891 may be symptomatic of long-term climatic change, perhaps indicative of global warming and destabilization of Pacific climate at the end of the Little Ice Age. During this period all but one of the years registering more than three days with rain exceeding 2.54 cm (1 in) in Tucson were El Nino events. The one exception was the summer of 1890, when the central equatorial Pacific was relatively cold but when prevailing low-surface pressures and low -level winds nevertheless steered tropical moisture from the west coast of Mexico into southern Arizona. In the twentieth century, catastrophic channel widening was caused by floods during El Nino events in 1905, 1915, 1977 and 1983. The Santa Cruz River arroyo formed when climatic conditions heightened the probabilities for occurrence of large floods in southern Arizona. Inadequate engineering of ditches that resulted in

  16. 27 CFR 9.129 - Arroyo Grande Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Arroyo Grande Valley. 9.129 Section 9.129 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas §...

  17. Chronostratigraphy of Kitchen Corral Wash, southern UT: Insights into Arroyo Aggradation and Entrenchment Events

    NASA Astrophysics Data System (ADS)

    Huff, W.; Rittenour, T. M.

    2012-12-01

    Fluvial systems in the semiarid southwestern United States are sensitive to Holocene climate change, as partly evidenced by entrenched, steep-walled arroyo channels throughout the region. Kitchen Corral Wash (KCW), a tributary of the Paria River in southern Utah, has experienced both historic and prehistoric (Holocene) episodes of arroyo cutting and filling. During the most recent arroyo-cutting event (~1880-1920 AD), KCW and other regional drainages were entrenched up to 30m into their fine-grained alluvial fill, leaving former floodplains perched above new channel bottoms. Alluvial sediments preserved within the exposed arroyos walls record largely aggradational sequences interrupted by periods of incision. Although arroyo entrenchment and aggradation processes have been studied for over a century, exact causes of arroyo cutting are still not fully understood. Hereford (2002) argued that arroyo dynamics are climatically driven based on near-synchronous timing of entrenchment in drainages from southern Utah and the surrounding region. However, recent results from KCW and nearby drainages suggest a more complex pattern. While previous studies have attempted to constrain the timing of arroyo cut-fill events in KCW, poor age control has limited results. In order to better understand the timing of arroyo events, this study aims to update and improve the arroyo cut-fill chronology from KCW by using detailed alluvial stratigraphic descriptions and age control from optically stimulated luminescence (OSL) and AMS radiocarbon dating. Preliminary results are based on twelve study sites, each exposing a number of cut-fill cycles in the arroyo-wall stratigraphy, and suggest at least four arroyo cycles over the last 4 ka. Forthcoming AMS and OSL results will be used to test hypotheses related to climatic forcing of arroyo dynamics by comparing the chronology from KCW to regional chronologies.

  18. Corrective measures evaluation report for Tijeras Arroyo groundwater.

    SciTech Connect

    Witt, Johnathan L; Orr, Brennon R.; Dettmers, Dana L.; Hall, Kevin A.; Howard, M. Hope

    2005-08-01

    This Corrective Measures Evaluation report was prepared as directed by a Compliance Order on Consent issued by the New Mexico Environment Department to document the process of selecting the preferred remedial alternative for Tijeras Arroyo Groundwater. Supporting information includes background concerning the site conditions and potential receptors and an overview of work performed during the Corrective Measures Evaluation. The evaluation of remedial alternatives included identifying and describing four remedial alternatives, an overview of the evaluation criteria and approach, comparing remedial alternatives to the criteria, and selecting the preferred remedial alternative. As a result of the Corrective Measures Evaluation, monitored natural attenuation of the contaminants of concern (trichloroethene and nitrate) is the preferred remedial alternative for implementation as the corrective measure for Tijeras Arroyo Groundwater. Design criteria to meet cleanup goals and objectives and the corrective measures implementation schedule for the preferred remedial alternative are also presented.

  19. 13. ARROYO SECO PARKWAY SEEN FROM DEBS PARK (APPROXIMATELY 34° ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. ARROYO SECO PARKWAY SEEN FROM DEBS PARK (APPROXIMATELY 34° 7' BY 118° 11' ON USGS LOS ANGELES QUADRANGLE). AVENUE 60 BRIDGE AT CENTER. LOOKING 240° WSW. - Arroyo Seco Parkway, Los Angeles to Pasadena, Los Angeles, Los Angeles County, CA

  20. 75 FR 37358 - Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for the Arroyo Toad

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-29

    ... (74 FR 52612) proposed rule incorporates new information on the distribution of arroyo toads that... FR 52612), including the changes to and considerations regarding proposed revised critical habitat in... critical habitat designation (74 FR 52612)). (16) Whether the conservation needs of the arroyo toad can...

  1. ARROYO SECO PARKWAY SOUTHBOUND LANES AND AT&SF RAILROAD OVERCROSSING. NOTE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ARROYO SECO PARKWAY SOUTHBOUND LANES AND AT&SF RAILROAD OVERCROSSING. NOTE GRADE CHANGE BETWEEN NORTH AND SOUTHBOUND LANES IN SUPER-ELEVATED CURVE. LOOKING 56°NE - Atchison, Topeka & Santa Fe Railroad Bridge, Spanning Arroyo Seco Parkway at parkway milepost 29.03, Los Angeles, Los Angeles County, CA

  2. Infiltration and quality of water for two arroyo channels, Albuquerque, New Mexico, 1988-92

    USGS Publications Warehouse

    Thomas, Carole L.

    1995-01-01

    Selected reaches of Grant Line Arroyo and Tijeras Arroyo in Albuquerque, New Mexico, were studied to collect information about the amount and quality of infiltration through arroyo channels. Infiltration rate was calculated for selected reaches of Grant Line Arroyo and Tijeras Arroyo based on instantaneous streamflow-loss volumes, wetted channel area, and instantaneous evaporation rates measured during 1988-92. Infiltration rates at Grant Line Arroyo ranged from 0.0 to 0.6 foot per day, and at Tijeras Arroyo from 2.28 to 30 feet per day. The evaporation rate ranged from one-tenth of 1 percent to 2 percent of the infiltration rate. Infiltration rates differed with the location of the reach isolated for measurement and with the time of day of the infiltration-rate measurement. Differences in intrinsic permeability of the sediments may be the most important factor affecting spatial variations in infiltration. The most important factor affecting temporal variations in infiltration may be the temperature of the water and sediment where infiltration occurs. Annual evaporation rates were greatest over saturated stream sediments and ranged from 802 to 1,025 millimeters per year or from 31.57 to 40.35 inches per year. Annual evaporation rates were least over unsaturated, unvegetated soil and ranged from 174 to 291 millimeters per year or from 6.85 to 11.46 inches per year. Annual evapotranspiration rates over grasses or shrubs or both were about one-half the rates over saturated stream sediments. Rates were similar for Grant Line and Tijeras Arroyos. The land- surface vegetation, availability of water at the land surface, availability of energy to enable a change of state from water to vapor, existence of a vapor concentration gradient, and a turbulent atmosphere to carry the vapor away may be the factors that determine the amount of evaporation and evapotranspiration. Water in Grant Line Arroyo and Tijeras Arroyo met U. S. Environmental Protection Agency drinking

  3. Corrective measures evaluation work plan : Tijeras Arroyo Groundwater : revision 0.

    SciTech Connect

    Wymore, Ryan A.; Collins, Sue S.; Skelly, Michael Francis; Koelsch, Michael C.

    2004-12-01

    This document, which is prepared as directed by the Compliance Order on Consent (COOC) issued by the New Mexico Environment Department, outlines a process to evaluate remedial alternatives to identify a corrective measure for the Sandia National Laboratories Tijeras Arroyo Groundwater (TAG). The COOC provides guidance for implementation of a Corrective Measures Evaluation (CME) for TAG. This Work Plan documents an initial screening of remedial technologies and presents a list of possible remedial alternatives for those technologies that passed the screening. This Work Plan outlines the methods for evaluating these remedial alternatives and describes possible site-specific evaluation activities necessary to estimate remedy effectiveness and cost. These methods will be reported in the CME Report. This Work Plan outlines the CME Report, including key components and a description of the corrective measures process.

  4. Sediment dynamics through space and time in the lower Rio Puerco arroyo, New Mexico

    NASA Astrophysics Data System (ADS)

    Griffin, E. R.; Friedman, J. M.; Vincent, K. R.

    2014-12-01

    The dynamics of riverine erosion and sediment transport can be episodic, spatially and temporally non-uniform, and strongly scale dependent. Identifying the events and processes that control these sediment dynamics requires precise measurements, but overcoming spatial and temporal variability requires observations over large distances and long times. Addressing this challenge, therefore, requires integration of data collection efforts at point, cross-section, reach, and whole-river scales. From the mid-1800s to about the 1930s, extreme high flows caused incision along the Rio Puerco, an ephemeral tributary of the Rio Grande located in semi-arid north-central New Mexico. The incision created an arroyo within the 1 to 2 km wide alluvial valley that by 1927 was an average of 118 m wide and 8.5 m deep. In the early 1900s, sediment transported from the Rio Puerco into the Rio Grande contributed to widespread flooding along the Rio Grande and concerns about filling of Elephant Butte Reservoir, located 100 km downstream. We reconstructed the history of arroyo evolution in a 55 km long segment of the lower Rio Puerco by combining data from 3 trenches excavated across the arroyo bottom with arroyo-scale information from aerial imagery, aerial light detection and ranging (LiDAR) data, longitudinal profiles, and repeat surveys of cross sections. We then examined changes through time since 1927 in arroyo width, depth, volume, morphology, and vegetation. A transition to filling after the 1930s involved vegetation development, channel narrowing, increased sinuosity, and finally vertical aggradation. This strongly depositional sediment transport regime interacted with floodplain shrubs to produce a characteristic narrow, trapezoidal channel. Our study reach demonstrated upstream progression of arroyo widening and filling, but not of arroyo incision, channel narrowing, or floodplain vegetation development. Since the 1970s, arroyo wall retreat has been mostly limited to locations

  5. Holocene Arroyo Records in Southern Utah: A balance between Climate Forcing and Geomorphic Thresholds

    NASA Astrophysics Data System (ADS)

    Rittenour, T. M.

    2012-12-01

    Around the turn of the last century (~1880±30 AD) semi-arid river systems in southern Utah and throughout the southwest US began to incise into their fine-grained valley fills and form deep, vertical-walled arroyos (up to +30m). Multiple hypotheses have been proposed to explain this nearly instantaneous historical arroyo cutting event, ranging from poor-land use to climate change and intrinsic geomorphic processes. However, exposed stratigraphy along arroyo walls has revealed evidence for multiple Holocene cut-fill events, excluding human disturbance as a potential cause and suggesting cyclic or episodic forces at play. Recent compilation of fluvial chronologies from southern Utah and the surrounding region suggests two episodes of near synchronous arroyo cutting during the last millennia, evoking climate forcing (Hereford, 2002). However, updated and extended chronostratigraphic reconstructions suggest a more complex temporal and spatial pattern. Research goals are to better understand the balance between climate forcing and geomorphic thresholds in these dynamic arroyo systems. New AMS radiocarbon and single-grain OSL chronologies combined with detailed alluvial stratigraphy from four adjoining catchments in southern Utah are presented. Study catchments (Escalante River, Kitchen Corral Wash, Johnson Wash and Kanab Creek) are all characterized by steep topographic gradients, high sediment production from local bedrock, and high seasonality and inter-annual variability due to influences of ENSO and monsoonal precipitation. Results suggest up to six late Holocene arroyo cut-fill sequences, with up to three entrenchment events in the last millennia in some catchments. While historic arroyo incision was near synchronous in the study catchments (~1880-1909 AD), correlations between the number and timing of past entrenchment events is not clear, suggesting the importance of catchment-specific geomorphic thresholds. Climate-related changes in hydrology are also

  6. Managing Floods and Resources at the Arroyo Las Positas

    SciTech Connect

    Sanchez, L; Van Hattem, M; Mathews, S

    2002-03-05

    Engineers and water resource professionals are challenged with protecting facilities from flood events within environmental resource protection, regulatory, and economic constraints. One case in point is the Arroyo Las Positas (ALP), an intermittent stream that traverses the Lawrence Livermore National Laboratory (LLNL) in Livermore, California. Increased runoff from post-drought rainfall, upstream development, and new perennial discharges from LLNL activities have resulted in increased dry weather flows and wetland vegetation. These new conditions have recently begun to provide improved habitat for the federally threatened California red-legged frog (Rana aurora draytonii; CRLF), but the additional vegetation diminishes the channel's drainage capacity and increases flood risk. When LLNL proposed to re-grade the channel to reestablish the 100-year flood capacity, traditional dredging practices were no longer being advocated by environmental regulatory agencies. LLNL therefore designed a desilting maintenance plan to protect LLNL facility areas from flooding, while minimizing impacts to wetland resources and habitat. The result was a combination of structural upland improvements and the ALP Five Year Maintenance Plan (Maintenance Plan), which includes phased desilting in segments so that the entire ALP is desilted after five years. A unique feature of the Maintenance Plan is the variable length of the segments designed to minimize LLNL's impact on CRLF movement. State and federal permits also added monitoring requirements and additional constraints on desilting activities. Two years into the Maintenance Plan, LLNL is examining the lessons learned on the cost-effectiveness of these maintenance measures and restrictions and reevaluating the direction of future maintenance activities.

  7. Streamflow, Infiltration, and Recharge in Arroyo Hondo, New Mexico

    USGS Publications Warehouse

    Moore, Stephanie J.

    2007-01-01

    Infiltration events in channels that flow only sporadically produce focused recharge to the Tesuque aquifer in the Espa?ola Basin. The current study examined the quantity and timing of streamflow and associated infiltration in Arroyo Hondo, an unregulated mountain-front stream that enters the basin from the western slope of the Sangre de Cristo Mountains. Traditional methods of stream gaging were combined with environmental-tracer based methods to provide the estimates. The study was conducted during a three-year period, October 1999?October 2002. The period was characterized by generally low precipitation and runoff. Summer monsoonal rains produced four brief periods of streamflow in water year 2000, only three of which extended beyond the mountain front, and negligible runoff in subsequent years. The largest peak flow during summer monsoon events was 0.59 cubic meters per second. Snowmelt was the main contributor to annual streamflow. Snowmelt produced more cumulative flow downstream from the mountain front during the study period than summer monsoonal rains. The presence or absence of streamflow downstream of the mountain front was determined by interpretation of streambed thermographs. Infiltration rates were estimated by numerical modeling of transient vertical streambed temperature profiles. Snowmelt extended throughout the instrumented reach during the spring of 2001. Flow was recorded at a station two kilometers downstream from the mountain front for six consecutive days in March. Inverse modeling of this event indicated an average infiltration rate of 1.4 meters per day at this location. For the entire study reach, the estimated total annual volume of infiltration ranged from 17,100 to 246,000 m3 during water years 2000 and 2001. During water year 2002, due to severe drought, streamflow and streambed infiltration in the study reach were both zero.

  8. Effects of piping irrigation laterals on selenium and salt loads, Montrose Arroyo Basin, western Colorado

    USGS Publications Warehouse

    Butler, D.L.

    2001-01-01

    Selenium and salinity are water-quality issues in the Upper Colorado River Basin. Certain water bodies in the lower Gunnison River Basin, including the lower Gunnison River and the Uncompahgre River, exceed the State standard for selenium of 5 micrograms per liter. Remediation methods to reduce selenium and salt loading in the lower Gunnison River Basin were examined. A demonstration project in Montrose Arroyo, located in the Uncompahgre River Basin near Montrose, was done during 1998-2000 to determine the effects on selenium and salt loads in Montrose Arroyo from replacing 8.5 miles of open-ditch irrigation laterals with 7.5 miles of pipe. The participants in the project were the National Irrigation Water Quality Program, the Colorado River Basin Salinity Control Program, the Uncompahgre Valley Water Users Association, and the U.S. Geological Survey. The placing of five laterals in pipe significantly decreased selenium loads in Montrose Arroyo. The selenium load at the outflow monitoring site was about 194 pounds per year less (28-percent decrease) in the period after the laterals were placed in pipe. More than 90 percent of the decrease in selenium load was attributed to a decrease in ground-water load. Salt loads also decreased because of the lateral project, but by a smaller percentage than the selenium loads. The salt load at the outflow site on Montrose Arroyo was about 1,980 tons per year less in the post-project period than in the pre-project period. All of the effects of the demonstration project on selenium and salt loads probably were not measured by this study because some of the lateral leakage that was eliminated had not necessarily discharged to Montrose Arroyo upstream from the monitoring sites. A greater decrease in selenium loads relative to salt loads may have been partially the result of decreases in selenium concentrations in ground water in some areas.

  9. Correction of locality records for the endangered arroyo toad (Anaxyrus californicus) from the desert region of southern California

    USGS Publications Warehouse

    Ervin, Edward L.; Beaman, Kent R.; Fisher, Robert N.

    2013-01-01

    The recovery strategy for an endangered species requires accurate knowledge of its distribution and geographic range. Although the best available information is used when developing a recovery plan, uncertainty often remains in regard to a species actual geographic extent. The arroyo toad (Anaxyrus californicus) occurs almost exclusively in coastal drainages, from Monterey County, California, south into northwestern Baja California, Mexico. Through field reconnaissance and the study of preserved museum specimens we determined that the four reported populations of the arroyo toad from the Sonoran Desert region of Riverside, San Diego, and Imperial counties, California are in error. Two additional sites in the Sonoran Desert are discussed regarding the possibility that the arroyo toad occurs there. We recommend the continued scrutiny of arroyo toad records to maintain a high level of accuracy of its distribution and geographic extent.

  10. Evaluation of Arroyo Channel Restoration Efforts using Hydrological Modeling: Rancho San Bernardino, Sonora, MX

    NASA Astrophysics Data System (ADS)

    Jemison, N. E.; DeLong, S.; Henderson, W. M.; Adams, J.

    2012-12-01

    In the drylands of the southwestern U.S. and northwestern Mexico, historical river channel incision (arroyo cutting) has led to the destruction of riparian ecological systems and cieñega wetlands in many locations. Along Silver Creek on the Arizona-Sonora border, the Cuenca Los Ojos Foundation has been installing rock gabions and concrete and earthen berms with a goal of slowing flash floods, raising groundwater levels, and refilling arroyo channels with sediment in an area that changed from a broad, perennially wet cieñega to a narrow sand- and gravel-dominated arroyo channel with an average depth of ~6 m. The engineering efforts hope to restore desert wetlands, regrow riparian vegetation, and promote sediment deposition along the arroyo floor. Hydrological modeling allows us to predict how rare flood events interact with the restoration efforts and may guide future approaches to dryland ecological restoration. This modeling is complemented by detailed topographic surveying and use of streamflow sensors to monitor hydrological processes in the restoration project. We evaluate the inundation associated with model 10-, 50-, 100-, 500-, and 1,000-year floods through the study area using FLO-2D and HEC-RAS modeling environments in order to evaluate the possibility of returning surface inundation to the former cieñega surface. According to HEC-RAS model predictions, given current channel configuration, it would require a 500-year flood to overtop the channel banks and reinundate the cieñega (now terrace) surface, though the 100-year flood may lead to limited terrace surface inundation. Based on our models, 10-year floods were ~2 m from overtopping the arroyo walls, 50-year floods came ~1.5 m from overtopping the arroyos, 100-year floods were ~1.2 m from overtopping, and 500- and 1,000-year floods at least partially inundated the cieñega surface. The current topography of Silver Creek does not allow for frequent flooding of the former cieñega; model predictions

  11. Streamflow, Infiltration, and Ground-Water Recharge at Abo Arroyo, New Mexico

    USGS Publications Warehouse

    Stewart-Deaker, Amy E.; Stonestrom, David A.; Moore, Stephanie J.

    2007-01-01

    Abo Arroyo, an ephemeral tributary to the Rio Grande, rises in the largest upland catchment on the eastern side of the Middle Rio Grande Basin (MRGB). The 30-kilometer reach of channel between the mountain front and its confluence with the Rio Grande is incised into basin-fill sediments and separated from the regional water table by an unsaturated zone that reaches 120 meters thick. The MRGB portion of the arroyo is dry except for brief flows generated by runoff from the upland catchment. Though brief, ephemeral flows provide a substantial fraction of ground-water recharge in the southeastern portion of the MRGB. Previous estimates of average annual recharge from Abo Arroyo range from 1.3 to 21 million cubic meters. The current study examined the timing, location, and amount of channel infiltration using streamflow data and environmental tracers during a four-year period (water years 1997?2000). A streamflow-gaging station (?gage?) was installed in a bedrock-controlled reach near the catchment outlet to provide high-frequency data on runoff entering the basin. Streamflow at the gage, an approximate bound on potential tributary recharge to the basin, ranged from 0.8 to 15 million cubic meters per year. Storm-generated runoff produced about 98 percent of the flow in the wettest year and 80 percent of the flow in the driest year. Nearly all flows that enter the MRGB arise from monsoonal storms in July through October. A newly developed streambed temperature method indicated the presence and duration of ephemeral flows downstream of the gage. During the monsoon season, abrupt downward shifts in streambed temperatures and suppressed diurnal ranges provided generally clear indications of flow. Streambed temperatures during winter showed that snowmelt is also effective in generating channel infiltration. Controlled infiltration experiments in dry arroyo sediments indicated that most ephemeral flow is lost to seepage before reaching the Rio Grande. Streambed temperature

  12. Final Report for the Arroyo Las Positas Maintenance Impact Study, Lawrence Livermore National Laboratory

    SciTech Connect

    van Hattem, M; Paterson, L

    2006-01-12

    In 2000, the Lawrence Livermore National Laboratory's (LLNL) Environmental Protection Department, in coordination with Plant Engineering (PE), began dredging sections of the Arroyo Las Positas (ALP) to alleviate concerns about flooding of sensitive facilities within the mainsite of Lawrence Livermore National Laboratory. In order to reduce potential impacts on the federally threatened California red-legged frog (Rana aurora draytonii), LLNL proposed to dredge sections of the ALP in a ''checkerboard pattern'', resulting in a mosaic of open water habitat and vegetated sections (Figure 1). The Arroyo Las Positas Management Plan (Plan) was coordinated with both state and federal agencies including the U.S. Fish and Wildlife Service (USFWS), California Department of Fish and Game (CDF&G), San Francisco Regional Water Quality Control Board (SFRWQCB), and the Army Corp of Engineers (ACOE). Water Discharge Requirements (WDRs) were issued for this project on December 30, 1999 (Order No. 99-086) by the SFRWQCB. Provision 19 of the WDRs outlined a five-year (2000 through 2004) Maintenance Impact Study (MIS) that LLNL began in coordination with dredging work that was conducted as part of the Arroyo Las Positas Management Plan. Provision 20 of these WDRs requires LLNL to submit a final report of the results of the Maintenance Impact Study for this project to the SFRWQCB. The purpose of this report is to present the results of the Maintenance Impact Study for Arroyo Las Positas and meet the requirements of Provision 20. A description of the annual monitoring included in this Maintenance Impact Study is included in the methods section of this report. Initially the Plan called for dredging the entire length of the Arroyo Las Positas (approximately 6,981 linear feet) over a 5-year period to minimize temporal impacts on the California red-legged frog. Dredging occurred in 2000 ({approx}1,300 ft.), 2001 ({approx}800 ft.), and 2002 ({approx}1,200 ft.), which constituted approximately

  13. Holocene landscape change, anthropogenic land-use change and arroyo formation on southwestern Santa Cruz Island, California

    NASA Astrophysics Data System (ADS)

    Perroy, R.; Bookhagen, B.; Chadwick, O.; Howarth, J.

    2011-12-01

    In this study, we untangle the relative importance of climatic, tectonic, and anthropogenic drivers as triggers of arroyo formation and geomorphic change for a small watershed on southwestern Santa Cruz Island, off the central California coast. Within the Pozo watershed, historic arroyo incision occurred contemporaneously with arroyo incision across many of the world's dryland regions. Unlike many of these other sites, Pozo contains a dateable record that allows quantification of aggradation rates from the mid-to-late Holocene to the 20th century. Basin-wide environmental changes were assessed using a combination of cosmogenic radionuclide inventories, midden and marine-shell deposits, relict soil properties, airborne and ground-based lidar data, ranching artifacts, and historic written records. Shortly after the introduction of grazing animals in the mid-nineteenth century, localized aggradation rates on the Pozo floodplain increased by two orders of magnitude from 0.4 mm/yr to ~25 mm/yr. Accelerated aggradation was followed by arroyo formation ca. 1878 and rapid expansion of the incipient gully network, the lateral extent of which has been largely maintained since 1929. Basin-averaged erosion rates from cosmogenic radionuclide measurements indicate that pre-settlement rates were <0.08 mm/yr, while lidar-derived measurements of historic gully erosion produce estimates almost two orders of magnitude higher (~4 mm/yr). Measurements since 2005 indicate that the active channel of the Pozo basin is aggrading. We argue that accelerated aggradation due to overgrazing set the stage for arroyo formation in Pozo watershed between 1875 and 1886. This period coincides with an unusually large rainstorm event in 1878 that further facilitated arroyo formation.

  14. Habitat use and movement of the endangered Arroyo Toad (Anaxyrus californicus) in coastal southern California

    USGS Publications Warehouse

    Gallegos, Elizabeth; Lyren, Lisa M.; Lovich, Robert E.; Mitrovich, Milan J.; Fisher, Robert N.

    2011-01-01

    Information on the habitat use and movement patterns of Arroyo Toads (Anaxyrus californicus) is limited. The temporal and spatial characteristics of terrestrial habitat use, especially as it relates to upland use in coastal areas of the species' range, are poorly understood. We present analyses of radiotelemetry data from 40 individual adult toads tracked at a single site in coastal southern California from March through November of 2004. We quantify adult Arroyo Toad habitat use and movements and interpret results in the context of their life history. We show concentrated activity by both male and female toads along stream terraces during and after breeding, and, although our fall sample size is low, the continued presence of adult toads in the floodplain through the late fall. Adult toads used open sandy flats with sparse vegetation. Home-range size and movement frequency varied as a function of body mass. Observed spatial patterns of movement and habitat use both during and outside of the breeding period as well as available climatological data suggest that overwintering of toads in floodplain habitats of near-coastal areas of southern California may be more common than previously considered. If adult toads are not migrating out of the floodplain at the close of the breeding season but instead overwinter on stream terraces in near-coastal areas, then current management practices that assume toad absence from floodplain habitats may be leaving adult toads over-wintering on stream terraces vulnerable to human disturbance during a time of year when Arroyo Toad mortality is potentially highest.

  15. Habitat use and movement of the endangered Arroyo Toad (Anaxyrus californicus) in coastal southern California

    USGS Publications Warehouse

    Mitrovich, M.J.; Gallegos, E.A.; Lyren, L.M.; Lovich, R.E.; Fisher, R.N.

    2011-01-01

    Information on the habitat use and movement patterns of Arroyo Toads (Anaxyrus californicus) is limited. The temporal and spatial characteristics of terrestrial habitat use, especially as it relates to upland use in coastal areas of the species' range, are poorly understood. We present analyses of radiotelemetry data from 40 individual adult toads tracked at a single site in coastal southern California from March through November of 2004. We quantify adult Arroyo Toad habitat use and movements and interpret results in the context of their life history. We show concentrated activity by both male and female toads along stream terraces during and after breeding, and, although our fall sample size is low, the continued presence of adult toads in the floodplain through the late fall. Adult toads used open sandy flats with sparse vegetation. Home-range size and movement frequency varied as a function of body mass. Observed spatial patterns of movement and habitat use both during and outside of the breeding period as well as available climatological data suggest that overwintering of toads in floodplain habitats of near-coastal areas of southern California may be more common than previously considered. If adult toads are not migrating out of the floodplain at the close of the breeding season but instead overwinter on stream terraces in near-coastal areas, then current management practices that assume toad absence from floodplain habitats may be leaving adult toads over-wintering on stream terraces vulnerable to human disturbance during a time of year when Arroyo Toad mortality is potentially highest. ?? 2011 Society for the Study of Amphibians and Reptiles.

  16. Managing the Arroyo Seco for Flood Prevention, Erosion Control, Waterway and Habitat Restoration

    SciTech Connect

    Sanchez, L; Wang, C; Laurant, J

    2003-02-06

    One of the most important tasks for a site facility manager is to ensure that appropriate channel erosion controls are applied to on-site drainage channels. These erosion controls must minimize risks to the public and structures. Water and sediment loads commonly originate from off-site sources and many of the traditional reactionary measures (installing rip-rap or some other form of bed or bank armor) simply transfer or delay the problem. State and federal agency requirements further complicate the management solution. One case in point is the Arroyo Seco, an intermittent stream that runs along the southwest corner of the Lawrence Livermore National Laboratory (LLNL) in Livermore, California. In 2001, LLNL contracted Questa Engineering Corporation to conduct hydraulic, geomorphic, and biological investigations and to prepare an alternatives and constraints analysis. From these investigations, LLNL has selected a water management plan that encompasses overall flood prevention, erosion control, and waterway and habitat restoration and enhancement elements. The most unique aspect of the Arroyo Seco management plan is its use of non-traditional and biotechnical techniques.

  17. Cardiovascular Surgery Residency Program: Training Coronary Anastomosis Using the Arroyo Simulator and UNIFESP Models

    PubMed Central

    Maluf, Miguel Angel; Gomes, Walter José; Bras, Ademir Massarico; de Araújo, Thiago Cavalcante Vila Nova; Mota, André Lupp; Cardoso, Caio Cesar; Coutinho, Rafael Viana dos S.

    2015-01-01

    OBJECTIVE Engage the UNIFESP Cardiovascular Surgery residents in coronary anastomosis, assess their skills and certify results, using the Arroyo Anastomosis Simulator and UNIFESP surgical models. METHODS First to 6th year residents attended a weekly program of technical training in coronary anastomosis, using 4 simulation models: 1. Arroyo simulator; 2. Dummy with a plastic heart; 3. Dummy with a bovine heart; and 4. Dummy with a beating pig heart. The assessment test was comprised of 10 items, using a scale from 1 to 5 points in each of them, creating a global score of 50 points maximum. RESULTS The technical performance of the candidate showed improvement in all items, especially manual skill and technical progress, critical sense of the work performed, confidence in the procedure and reduction of the time needed to perform the anastomosis after 12 weeks practice. In response to the multiplicity of factors that currently influence the cardiovascular surgeon training, there have been combined efforts to reform the practices of surgical medical training. CONCLUSION 1 - The four models of simulators offer a considerable contribution to the field of cardiovascular surgery, improving the skill and dexterity of the surgeon in training. 2 - Residents have shown interest in training and cooperate in the development of innovative procedures for surgical medical training in the art. PMID:26735604

  18. Arroyo Mocho Boulder Removal Project: Lawrence Livermore National Laboratory Hetch Hetchy Pump Station

    SciTech Connect

    Burkholder, L; Kato, T; Van Hattem, M

    2007-06-28

    The purpose of this biological assessment is to review the proposed Arroyo Mocho Boulder Removal Project in sufficient detail to determine to what extent the proposed action may affect any of the threatened, endangered, proposed, or sensitive species and designated or proposed critical habitats listed below. In addition, the following information is provided to comply with statutory requirements to use the best scientific and commercial information available when assessing the risks posed to listed and/or proposed species and designated and/or proposed critical habitat by proposed federal actions. This biological assessment is prepared in accordance with legal requirements set forth under regulations implementing Section 7 of the Endangered Species Act (50 CFR 402; 16 U.S.C 1536 (c)). It is our desire for the Arroyo Mocho Boulder Removal Project to receive incidental take coverage for listed species and critical habitat within the greater project area by means of amending the previous formal Section 7 consultation (1-1-04-F-0086) conducted a few hundred meters downstream by Lawrence Livermore National Laboratory (LLNL) in 2002. All conservation measures, terms and conditions, and reporting requirements from the previous Biological Opinion (1-1-04-F-0086) have been adopted for this Biological Assessment and/or amendment.

  19. Rates of sediment supply to arroyos from upland erosion determined using in situ produced cosmogenic 10Be and 26Al

    USGS Publications Warehouse

    Clapp, Erik M.; Bierman, Paul R.; Nichols, Kyle K.; Pavich, Milan; Caffee, Marc A.

    2001-01-01

    Using 10Be and 26Al measured in sediment and bedrock, we quantify rates of upland erosion and sediment supply to a small basin in northwestern New Mexico. This and many other similar basins in the southwestern United States have been affected by cycles of arroyo incision and backfilling several times in the past few millennia. The sediment generation (275 ± 65 g m−2 yr−1) and bedrock equivalent lowering rates (102 ± 24 m myr−1) we determine are sufficient to support at least three arroyo cycles in the past 3,000 years, consistent with rates calculated from a physical sediment budget within the basin and regional rates determined using other techniques. Nuclide concentrations measured in different sediment sources and reservoirs suggest that the arroyo is a good spatial and temporal integrator of sediment and associated nuclide concentrations from throughout the basin, that the basin is in steady-state, and that nuclide concentration is independent of sediment grain size. Differences between nuclide concentrations measured in sediment sources and reservoirs reflect sediment residence times and indicate that subcolluvial bedrock weathering on hillslopes supplies more sediment to the basin than erosion of exposed bedrock.

  20. Sediment discharge in the Upper Arroyo Grande and Santa Rita Creek basins, San Luis Obispo County, California

    USGS Publications Warehouse

    Knott, J.M.

    1976-01-01

    Sediment data collected in the upper Arroyo Grande and Santa Rita Creek basins, San Luis Obispo County, California, during the 1968-73 water years were analyzed to determine total sediment discharge at four stations in the basins. Water discharge and total sediment discharge at these stations, representative of the 1943-72 period, were estimated from long-term flow data for nearby gaging stations and water-sediment discharge relations determined for the 1968-73 water years. Most of the total annual sediment discharge at each station occurs during a few days each year. The quantity of sediment transported in a single day often accounts for more than 40 percent of the total annual sediment discharge. Estimated sediment discharge for the upper Arroyo Grande and Santa Rita Creek basins during the 1943-72 water years averaged 53,000 tons and 23,000 tons per year. Long-term sediment deposition in Lopez Reservoir, which is in the southern part of the upper Arroyo Grande basin, was estimated to be 35 acre-feet per year. (Woodard-USGS)

  1. Shallow Structure of the Eagle Rock and Raymond Faults in Arroyo Seco, Los Angeles County, California

    NASA Astrophysics Data System (ADS)

    Scheirer, D. S.; Rymer, M. J.; Catchings, R. D.; Goldman, M.; Fuis, G.

    2012-12-01

    To understand the location, dip, and possible structural connection of the Eagle Rock and Raymond faults in Pasadena and South Pasadena, California, we acquired and analyzed high-resolution seismic reflection and refraction data, as well as gravity observations, along the floor of the Arroyo Seco. The studies were conducted to aid in understanding the seismic hazards of these faults in this urban setting. Seismic reflection and refraction data, including both P-wave and S-wave records, were collected along two profiles, a 1.2-km-long northern profile crossing the Eagle Rock fault, and a 450-m-long southern profile crossing the Raymond fault. Seismic sources were Betsy-Seisgun shots, accelerated weight drops, and repeated sledge-hammer impacts, which were recorded on multi-channel seismograph systems connected to vertical- and horizontal-component geophones spaced at a 5-m interval. Gravity data were collected along a single ~3-km-long profile coincident with and extending beyond and between the two seismic profiles, with stations spaced every 25-m near the fault traces and at greater intervals farther from the fault traces. We carefully accounted for the gravity effects of the adjacent concrete drainage channel and of the walls of the arroyo, to generate gravity anomalies that reflect sub-surface density contrasts across the Eagle Rock and Raymond faults. Seismic reflection image quality is compromised by the highly-deformed Miocene strata offset by these faults. However, reflection and especially refraction results indicate that both the Eagle Rock and Raymond faults consist of multiple, steeply-north-dipping fault strands. P- and S-wave seismic tomography results of the uppermost 50-100 m yield velocity variations that can be converted to probable density variations, and thus be included in the gravity anomaly analysis. The gravity anomalies predicted from the velocity variations account for less than one-third of the anomalies observed across the faults

  2. Characterization of salinity and selenium loading and land-use change in Montrose Arroyo, western Colorado, from 1992 to 2010

    USGS Publications Warehouse

    Moore, Jennifer L.

    2011-01-01

    Salinity and selenium are naturally occurring and perva-sive in the lower Gunnison River Basin of Colorado, includ-ing the watershed of Montrose Arroyo. Although some of the salinity and selenium loading in the Montrose Arroyo study area is from natural sources, additional loading has resulted from the introduction of intensive irrigation in the water-shed. With increasing land-use change and the conversion from irrigated agricultural to urban land, land managers and stakeholders need information about the long-term effects of land-use change on salinity and selenium loading. In response to the need to advance salinity and selenium science, the U.S. Geological Survey, in cooperation with the Bureau of Reclamation, Colorado River Basin Salinity Control Forum, and Colorado River Water Conservation District, developed a study to characterize salinity and selenium loading and how salinity and selenium sources may relate to land-use change in Montrose Arroyo. This report characterizes changes in salinity and selenium loading to Montrose Arroyo from March 1992 to February 2010 and the magnitude of land-use change between unirrigated desert, irrigated agricultural, and urban land-use/land-cover types, and discusses how the respective loads may relate to land-use change. Montrose Arroyo is an approximately 8-square-mile watershed in Montrose County in western Colorado. Salinity and selenium were studied in Montrose Arroyo in a 2001 study as part of a salinity- and selenium-control lateral project. The robust nature of the historical dataset indicated that Montrose Arroyo was a prime watershed for a follow-up study. Two sites from the 2001 study were used to monitor salinity and selenium loads in Montrose Arroyo in the follow-up study. Over the period of 2 water years and respective irrigation seasons (2008-2010), 27 water-quality samples were collected and streamflow measurements were made at the historical sites MA2 and MA4. Salinity and selenium concen-trations, loads

  3. Anastomosing channels and arroyo development on the Nogoa River, Central Queensland, Australia

    NASA Astrophysics Data System (ADS)

    Finlayson, B. L.; Brizga, S. O.

    1993-05-01

    It is widely accepted that European settlement in Australia has had a major impact on river channels. For many parts of Australia records are available which permit the history of channel changes to be reconstructed over most of the post-settlement period. In this paper the history of changes on part of the Nogoa River in Central Queensland is described from the first European contact until the present. The river channel at this site has changed from an anastomosing pattern to a single large channel (arroyo). There is evidence to suggest that such changes have occurred also in the past but an unusual feature of the present incision phase is that incision is synchronous throughout the region. This may have been triggered by the introduction of cattle which naturally congregate in the moister valley bottoms in this otherwise dry environment. The changes observed here reflect those reported for the semiarid regions of the USA. A linking factor appears to be hydrological behaviour characterised by high levels of variability in the annual flood series, which appears to render such streams more sensitive to disturbance than those with less variable flood behaviour.

  4. Arroyo channel head evolution in a flash-flood-dominated discontinuous ephemeral stream system

    USGS Publications Warehouse

    DeLong, Stephen B.; Johnson, Joel P.L.; Whipple, Kelin X.

    2014-01-01

    We study whether arroyo channel head retreat in dryland discontinuous ephemeral streams is driven by surface runoff, seepage erosion, mass wasting, or some combination of these hydrogeomorphic processes. We monitored precipitation, overland flow, soil moisture, and headcut migration over several seasonal cycles at two adjacent rangeland channel heads in southern Arizona. Erosion occurred by headward retreat of vertical to overhanging faces, driven dominantly by surface runoff. No evidence exists for erosion caused by shallow-groundwater–related processes, even though similar theater-headed morphologies are sometimes attributed to seepage erosion by emerging groundwater. At our field site, vertical variation in soil shear strength influenced the persistence of the characteristic theater-head form. The dominant processes of erosion included removal of grains and soil aggregates during even very shallow (1–3 cm) overland flow events by runoff on vertical to overhanging channel headwalls, plunge-pool erosion during higher-discharge runoff events, immediate postrunoff wet mass wasting, and minor intra-event dry mass wasting on soil tension fractures developing subparallel to the headwall. Multiple stepwise linear regression indicates that the migration rate is most strongly correlated with flow duration and total precipitation and is poorly correlated with peak flow depth or time-integrated flow depth. The studied channel heads migrated upslope with a self-similar morphologic form under a wide range of hydrological conditions, and the most powerful flash floods were not always responsible for the largest changes in landscape form in this environment. 

  5. Adaptive Optics: Arroyo Simulation Tool and Deformable Mirror Actuation Using Golay Cells

    NASA Technical Reports Server (NTRS)

    Lint, Adam S.

    2005-01-01

    The Arroyo C++ libraries, written by Caltech post-doc student Matthew Britton, have the ability to simulate optical systems and atmospheric signal interference. This program was chosen for use in an end-to-end simulation model of a laser communication system because it is freely distributed and has the ability to be controlled by a remote system or "smart agent." Proposed operation of this program by a smart agent has been demonstrated, and the results show it to be a suitable simulation tool. Deformable mirrors, as a part of modern adaptive optics systems, may contain thousands of tiny, independently controlled actuators used to modify the shape of the mirror. Each actuator is connected to two wires, creating a cumbersome and expensive device. Recently, an alternative actuation method that uses gas-filled tubes known as Golay cells has been explored. Golay cells, operated by infrared lasers instead of electricity, would replace the actuator system thereby creating a more compact deformable mirror. The operation of Golay cells and their ability to move a deformable mirror in excess of the required 20 microns has been demonstrated. Experimentation has shown them to be extremely sensitive to pressure and temperature, making them ideal for use in a controlled environment.

  6. Performance of building materials under load stresses: the case of Arroyo Meaques Bridge in Madrid, Spain

    NASA Astrophysics Data System (ADS)

    Mencías, David; Gomez-Heras, Miguel; Lopez-Gonzalez, Laura

    2015-04-01

    In most masonry structures analyzed by limit state models, it is not possible to determine where thrust lines are located or stress fields are defined. This is because very small modifications of the geometry can modify considerably a stress situation. Moreover, structural safety of this kind of construction is mainly established by equilibrium, and structural analysis is based on this premise. However, from the point of view of a stress model, the thrust line can be approximately positioned (either graphically or by analytical methods) only from a geometrical description and material properties and, therefore, determine the amount of stresses that masonry undergoes. This research tries to provide the relationship between geometry and thrust line analysis, applied to the 17th century Arroyo Meaques Bridge. This is a brick and stone bridge, located at the southwest edge of Casa de Campo in Madrid (Spain) and it actually sets up the limit of the municipality of Madrid. The bridge was designed by architect Francesco Sabatini as a part of a set of improvements of Madrid city center. Starting from a geometrical surveying and photogrammetric restitution, a 3-dimension CAD model is performed, in which all geometrical conditions are collected. At the same time, elastic properties, compactness and strength of bricks were determined by means of non-destructive techniques, such as Schmidt hammer and ultrasound pulse velocity. All this information is uploaded to a GIS and 2D maps are generated. Brick physical properties were compared to previously done thrust line analysis to understand the relationship between maximum stresses and brick performance. This technique may be a starting point for more specific analysis, once possible failure mechanisms are identified and can be a very simple method to identify how it can affect any geometrical changes. Research funded by Geomateriales 2 S2013/MIT-2914, CEI Moncloa (UPM, UCM, CSIC) through a PICATA contract and the foundation

  7. "War on Terror" Is a Curative: Recontextualization and Political Myth-Making in Gloria Macapagal-Arroyo's 2002-2004 State of the Nation Addresses

    ERIC Educational Resources Information Center

    Navera, Gene Segarra

    2011-01-01

    The article examines the State of the Nation addresses (SONA) delivered by Philippine President Gloria Macapagal-Arroyo (2001-2010) from 2002-2004, during which time she actively invoked the need to engage in the U.S. government-led "global war on terror." It specifically investigates how these presidential speeches recontextualized the war on…

  8. Channel and hillslope processes revisited in the Arroyo de los Frijoles watershed near Santa Fe, New Mexico

    USGS Publications Warehouse

    Gellis, Allen C.; Emmett, William W.; Leopold, Luna B.

    2005-01-01

    Many of the original study sites were relocated and surveyed in the mid-1990's to determine subsequent channel and hillslope changes and to determine whether trends of channel and hillslope aggradation and degradation that were evident in the 1950's and 1960's have continued. In general, the net change in channel geometry has been small over the last 30n40 years. The average change in cross-sectional area of 32 resurveyed cross sections was erosion of 0.27 square meter, which equates to a 4-percent increase in cross-sectional area. The average net change in thalweg elevation for 51 resurveyed cross sections was degradation of 0.04 meter. Unpublished data (1964n68) from the scour chains showed that 371 chains had an average scour of 0.14 (+/-) 0.14 meter and that 372 chains showed an average fill of 0.13 + 0.11 meter. Scour, found in the original study (1958n64) to be proportional to the square root of discharge, was confirmed with the addition of unpublished data (1964?68). The observed channel changes have no consistent trend, compared either to results observed in the original 1966 study or to distance from the watershed divide. The conclusion drawn in the original study was that most channels were aggrading; the resurvey showed that aggradation did not continue. An increase in housing and population in the Arroyo de los Frijoles watershed since the 1950's has led to more roads. Channel degradation is most noticeable at road crossings. The greatest degradation of the main channel Arroyo de los Frijoles, 1.53 meters, and the greatest aggradation, 0.38 meter, occur downstream and upstream, respectively, from a culvert in a dirt road. Periods of high average annual rainfall intensity reported for Santa Fe for 1853?80 immediately preceded late 19th century arroyo incision, and another period of high-intensity rainfall began in 1967. This may indicate that climatic factors are again favorable for arroyo incision in this part of New Mexico; data from this resurvey

  9. Assessing the Impacts of Climate and Land Use Change on Streamflow and Nutrient Loading in the Arroyo Colorado Watershed in Southern Texas

    NASA Astrophysics Data System (ADS)

    Osidele, O.; Sun, A.; Green, R.

    2011-12-01

    Based on results of the Second National Climate Assessment reported in 2009, the U.S. Global Change Research Program projects temperatures in southern Texas will increase 5 to 8° F by the end of the 21st century, with larger changes occurring under scenarios of higher greenhouse gas emissions. Temperature increases in summer are projected to be larger than in winter. Although drier conditions are expected in the region, sea-level rise, extreme rainfall events, and associated storm surges are projected to occur more frequently because of the likely increase in intensity of hurricanes and tropical storms in the Gulf of Mexico. The range of possible responses to climate change is attributable to a combination of characteristics at global, regional, and local scales. The risk of flooding and catastrophic infrastructure damage due to global climate phenomena has been incorporated into local climate adaptation plans for many low-lying areas and communities in the Gulf Coast region of southern Texas. However, because this region is dominated by irrigated agriculture and the population is projected to double by 2050, it is important to examine how climate change will affect water resources and environmental quality. The purpose of this study is to investigate the potential hydrologic and water quality impacts of projected climate change, land use change, and population change scenarios in the headwaters of the Arroyo Colorado. The results of this work will provide content for a web-based, collaborative geospatial decision support system being developed to support environmental management in the Arroyo Colorado Watershed. Presently, land use in the Arroyo Colorado Watershed is more than 50 percent agricultural and almost 25 percent residential with varying levels of urbanization. As a result, flow in the Arroyo Colorado is sustained primarily by discharge from municipal wastewater treatment facilities, irrigation return flows, and urban storm runoff. In this study

  10. Petrography and geochemistry of the Arroyo de la Virgen and Isla Mala plutons, southern Uruguay: Early proterozoic tectonic implications

    NASA Astrophysics Data System (ADS)

    Preciozzi, F.; Bourne, J. H.

    1992-10-01

    The Arroyo de la Virgen pluton (AVP) and the Isla Mala pluton (IMP) are relatively small zoned intrusions of Early Proterozoic age. Radiometric age determinations suggest that the IMP is a composite pluton. The composition of the AVP ranges from granodiorite to leucogranite, whereas that of the IMP ranges from hornblendite to leucogranite. Both intrusions feature hornblende (with relict clinopyroxene cores) and biotite as mafic minerals. Muscovite and garnet are present in the most evolved members of each suite. Development of secondary chlorite, epidote, and sericite is common. Quartz typically has undulose extinction. The plutons are massive except near the margins of the intrusion. Both intrusions feature a calc-alkaline chemistry, have peraluminous indices of approximately 1.0, and were emplaced at relatively high levels in the crust. Application of several tectonic discriminant diagrams suggests that the IMP formed in an active continental-margin type of tectonic environment, whereas the AVP is a subalkaline, post-orogenic pluton. The ages of the IMP leucogranite and the AVP are similar (2290 and 2225 Ma, respectively). The age of the IMP leucogranite represents the minimum reliable age of the principal metamorphic event in southern Uruguay. A number of small dikes were emplaced into both intrusions approximately 300 million years later and represent a distinct phase of intrusive activity in the region.

  11. Potential-Field and Seismic Reflection/Refraction Studies of the Eagle Rock and Raymond Faults in Arroyo Seco, Los Angeles County, California

    NASA Astrophysics Data System (ADS)

    Scheirer, D. S.; Rymer, M. J.; Catchings, R. D.; Goldman, M.; Fuis, G. S.

    2010-12-01

    In August 2007, we acquired high-resolution gravity and seismic reflection and refraction data across the Eagle Rock and Raymond faults in the Arroyo Seco, located in Pasadena and South Pasadena, California. The studies were conducted to aid in understanding the seismic hazards of these faults in this urban setting, specifically to detect and determine the location of all faults passing through the area and to characterize their dip and possible structural connections. Gravity data were collected along a single ~3-km-long profile, with stations spaced every 25-m close to the fault traces and at greater intervals away from the fault traces. Gravity station elevations from Real-Time Kinematic GPS solutions, along with careful accounting for the gravity effects of the adjacent concrete drainage channel and of the walls of the arroyo, allow for the calculation of gravity anomalies that reflect sub-surface density contrasts across the Eagle Rock and Raymond faults. Seismic reflection and refraction data, including both P-wave and S-wave records, were collected along two profiles, a northern one crossing the Eagle Rock fault with a length of 1200 m, and a southern one crossing the Raymond fault with a length of 450 m. The seismic profiles coincided with the longer gravity profile along the floor of the Arroyo Seco. Seismic sources included Betsy-Seisgun shots, accelerated weight drops, and repeated sledge hammer impacts, and receivers were geophones spaced at a 5-m interval. S-waves were generated and recorded at a subset of sites on each of the seismic lines. Seismic reflection and refraction images indicate that both the Eagle Rock and Raymond faults are comprised of multiple, steeply-dipping fault strands. P- and S-wave seismic tomography of the uppermost 50-100 m show velocity variations that can be converted to likely density variations, which can in turn be subtracted from the density variation needed by the gravity anomaly analysis. This process of stripping off

  12. Sedimentology and stratigraphy of the Palisades, Lower Comanche, and Arroyo Grande areas of the Colorado River Corridor, Grand Canyon, Arizona

    USGS Publications Warehouse

    Draut, Amy E.; Rubin, David M.; Dierker, Jennifer L.; Fairley, Helen C.; Griffiths, Ronald E.; Hazel, Joseph E., Jr.; Hunter, Ralph E.; Kohl, Keith; Leap, Lisa M.; Nials, Fred L.; Topping, David J.; Yeatts, Michael

    2005-01-01

    This report analyzes various depositional environments in three archaeologically significant areas of the Colorado River corridor in Grand Canyon. Archaeological features are built on and buried by fluvial, aeolian, and locally derived sediment, representing a complex interaction between geologic and cultural history. These analyses provide a basis for determining the potential influence of Glen Canyon Dam operations on selected archaeological sites and thus for guiding dam operations in order to facilitate preservation of cultural resources. This report presents initial results of a joint effort between geologists and archaeologists to evaluate the significance of various depositional processes and environments in the prehistoric formation and modern preservation of archaeological sites along the Colorado River corridor in Grand Canyon National Park. Stratigraphic investigations of the Palisades, Lower Comanche, and Arroyo Grande areas of Grand Canyon yield detailed information regarding the sedimentary history at these locations. Reconstruction of past depositional settings is critical to a thorough understanding of the geomorphic and stratigraphic evolution of these three archaeologically significant areas. This examination of past sedimentary environments allows the relative significance of fluvial, aeolian, debris-fan, and slope-wash sedimentary deposits to be identified at each site. In general the proportion of fluvial sediment (number and thickness of flood deposits) is shown to decrease away from the river, and locally derived sediment becomes more significant. Flood sequences often occur as 'couplets' that contain a fluvial deposit overlain by an interflood unit that reflects reworking of fluvial sediment at the land surface by wind and local runoff. Archaeological features are built on and buried by sediment of various depositional environments, implying a complex interaction between geologic and cultural history. Such field analysis, which combines

  13. Neural network prediction of carbonate lithofacies from well logs, Big Bow and Sand Arroyo Creek fields, Southwest Kansas

    USGS Publications Warehouse

    Qi, L.; Carr, T.R.

    2006-01-01

    In the Hugoton Embayment of southwestern Kansas, St. Louis Limestone reservoirs have relatively low recovery efficiencies, attributed to the heterogeneous nature of the oolitic deposits. This study establishes quantitative relationships between digital well logs and core description data, and applies these relationships in a probabilistic sense to predict lithofacies in 90 uncored wells across the Big Bow and Sand Arroyo Creek fields. In 10 wells, a single hidden-layer neural network based on digital well logs and core described lithofacies of the limestone depositional texture was used to train and establish a non-linear relationship between lithofacies assignments from detailed core descriptions and selected log curves. Neural network models were optimized by selecting six predictor variables and automated cross-validation with neural network parameters and then used to predict lithofacies on the whole data set of the 2023 half-foot intervals from the 10 cored wells with the selected network size of 35 and a damping parameter of 0.01. Predicted lithofacies results compared to actual lithofacies displays absolute accuracies of 70.37-90.82%. Incorporating adjoining lithofacies, within-one lithofacies improves accuracy slightly (93.72%). Digital logs from uncored wells were batch processed to predict lithofacies and probabilities related to each lithofacies at half-foot resolution corresponding to log units. The results were used to construct interpolated cross-sections and useful depositional patterns of St. Louis lithofacies were illustrated, e.g., the concentration of oolitic deposits (including lithofacies 5 and 6) along local highs and the relative dominance of quartz-rich carbonate grainstone (lithofacies 1) in the zones A and B of the St. Louis Limestone. Neural network techniques are applicable to other complex reservoirs, in which facies geometry and distribution are the key factors controlling heterogeneity and distribution of rock properties. Future work

  14. Paleoenvironmental reconstruction for the lower Pliocene Arroyo Piedras section (Tubará - Colombia): Implications for the Magdalena River - paleodelta’s dynamic

    NASA Astrophysics Data System (ADS)

    Molinares, C. E.; Martinez, J. I.; Fiorini, F.; Escobar, J.; Jaramillo, C.

    2012-11-01

    The Magdalena river transports one of the largest load of sediments per basin area in the world. Its delta position has changed several times over the Neogene. The Arroyo Piedras Section (169 m) in northern Colombia, contains part of the record of the Late Miocene to Early Pliocene evolution of the Magdalena paleodelta. The section was described and sampled for sedimentological and micropaleontological analyses. Based on lithofacies and benthic foraminifera content, the section was divided in three segments, and the upper segment was dated as Early Pliocene using planktonic foraminifera. The lower segment suggests siliciclastic sedimentation in a proximal prodelta/delta plain transitional environment. The intermediate segment suggests sedimentation in a lagoon and/or coastal swamp environment, whereas the upper segment is interpreted as the result of a transgression and subsequent deposition at the foreshore/upper shoreface environment, with a considerable decrease of terrigenous input. The decrease of sediment delivery to the delta produced by permanent El Niño-like conditions coupled with autocyclic processes could explain the transgressive pattern observed in the Arroyo de Piedras section during the Early Pliocene.

  15. Arroyo el Mimbral, Mexico, K/T unit: Origin as debris flow/turbidite, not a tsunami deposit

    NASA Technical Reports Server (NTRS)

    Bohor, Bruce F.; Betterton, William J.

    1993-01-01

    Coarse, spherule-bearing, elastic units have been discovered at 10 marine sites that span the K/T boundary in northeastern Mexico. We examined one of the best exposed sites in Arroyo el Mimbral, northwest of Tampico. The Mimbral outcrop displays a layered elastic unit up to 3 m thick enclosed by marly limestones of the Mendez (Latest Maastrichian) and Velasco (Earliest Danian) Formations. At its thickest point, this channelized elastic unit is comprised of 3 subunits: (1) a basal, poorly-sorted, ungraded calcareous spherule bed 1 m thick containing relict impact glass and shocked mineral grains, (2) a massive set of laminated calcite-cemented sandstones up to 2 m thick with plant debris at its base, (3) capped by a thin (up to 20 cm) set of rippled sandstone layers separated by silty mudstone drapes containing a small (921 pg/g) iridium anomaly. This tripartite elastic unit is conformably overlain by marls of the Velasco Formation. We also visited the La Lajilla site east of Ciudad Victoria; its stratigraphy is similar to Mimbral's, but its elastic beds are thinner and less extensive laterally. The Mimbral elastic unit has been interpreted previously as being deposited by a megawave or tsunami produced by an asteroid impact on nearby Yucatan (Chicxulub crater). However, a presumed 400-m paleodepth of water at the Mimbral site, channeling of the spherule subunit into the underlying Mendez Formation marls, and the overtopping of the basal, spherule-bearing subunit by the laminated sandstone subunit, all suggest a combined debris flow/turbidite origin for this elastic unit similar to that proposed for Upper Pleistocene sand/silt beds occurring elsewhere in the Gulf of Mexico. In this latter model, the sediment source region for the elastic unit is the lower continental shelf and slope escarpment. For the K/T unit at Mimbral, we propose that thick ejecta blanket deposits composed mostly of spherules were rapidly loaded onto the lower shelf and slope from an impact

  16. Mineralogical, IR-spectral and geochemical monitoring of hydrothermal alteration in a deformed and metamorphosed Jurassic VMS deposit at Arroyo Rojo, Tierra del Fuego, Argentina

    NASA Astrophysics Data System (ADS)

    Biel, C.; Subías, I.; Acevedo, R. D.; Yusta, I.; Velasco, F.

    2012-04-01

    The Arroyo Rojo Zn-Pb-Cu volcanogenic massive sulfide deposit is the main deposit of the Fin del Mundo District in the Fuegian Andes, Argentina. This deposit is hosted by a Middle Jurassic volcanic and volcanoclastic sequence forming the Lemaire Formation. The latter consists, from the base up, of the following: rhyolitic and dacitic porphyritic rocks, ignimbrite, tuff, and flow. It is underlain by a pre-Jurassic basement and overlain by the hyaloclastic andesites of the Yahgán Formation. The Arroyo Rojo consists of stacked lenticular lenses that are associated with disseminated mineralization in both the footwall and the hanging wall. The internal structure of the ore lenses is marked by the occurrence of massive, semi-massive and banded facies, along with stringer and brecciated zones and minor ore disseminations. The mineral assemblage comprises mainly pyrite and sphalerite, with minor amounts of galena and chalcopyrite and rare pyrrhotite, arsenopyrite, tetrahedrite and bournonite. The ores and the volcanic host rocks have metamorphosed to greenschist facies and were overprinted by a penetrative tectonic foliation, which led to the development of mylonitic, and cataclastic textures, recrystallization and remobilization. Primary depositional characteristics and regional and hydrothermal alteration patterns were preserved despite deformation and metamorphism. Therefore, primary banding was preserved between facies boundaries. In addition, some remnants of magmatic origin are recognizable in preserved phenocrysts and volcaniclastic phenoclasts. Most of the volcanic and volcaniclastic rocks of the host sequence show a rhyolitic to rhyo-dacitic composition. Regional seafloor alteration, characterized by the presence of clinozoisite, Fe-chlorite and titanite, along with quartz and albite, is partially obliterated by hydrothermal alteration. The hydrothermal alteration is stratabound with the following assemblages, which developed from the base to top: (1) Quartz

  17. Arroyo del Vizcaíno, Uruguay: a fossil-rich 30-ka-old megafaunal locality with cut-marked bones

    PubMed Central

    Fariña, Richard A.; Tambusso, P. Sebastián; Varela, Luciano; Czerwonogora, Ada; Di Giacomo, Mariana; Musso, Marcos; Bracco, Roberto; Gascue, Andrés

    2014-01-01

    Human–megafauna interaction in the Americas has great scientific and ethical interest because of its implications on Pleistocene extinction. The Arroyo del Vizcaíno site near Sauce, Uruguay has already yielded over 1000 bones belonging to at least 27 individuals, mostly of the giant sloth Lestodon. The assemblage shows some taphonomic features suggestive of human presence, such as a mortality profile dominated by prime adults and little evidence of major fluvial transport. In addition, several bones present deep, asymmetrical, microstriated, sharp and shouldered marks similar to those produced by human stone tools. A few possible lithic elements have also been collected, one of which has the shape of a scraper and micropolish consistent with usage on dry hide. However, the radiocarbon age of the site is unexpectedly old (between 27 and 30 thousand years ago), and thus may be important for understanding the timing of the peopling of America. PMID:24258717

  18. Arroyo del Vizcaíno, Uruguay: a fossil-rich 30-ka-old megafaunal locality with cut-marked bones.

    PubMed

    Fariña, Richard A; Tambusso, P Sebastián; Varela, Luciano; Czerwonogora, Ada; Di Giacomo, Mariana; Musso, Marcos; Bracco, Roberto; Gascue, Andrés

    2014-01-01

    Human-megafauna interaction in the Americas has great scientific and ethical interest because of its implications on Pleistocene extinction. The Arroyo del Vizcaíno site near Sauce, Uruguay has already yielded over 1000 bones belonging to at least 27 individuals, mostly of the giant sloth Lestodon. The assemblage shows some taphonomic features suggestive of human presence, such as a mortality profile dominated by prime adults and little evidence of major fluvial transport. In addition, several bones present deep, asymmetrical, microstriated, sharp and shouldered marks similar to those produced by human stone tools. A few possible lithic elements have also been collected, one of which has the shape of a scraper and micropolish consistent with usage on dry hide. However, the radiocarbon age of the site is unexpectedly old (between 27 and 30 thousand years ago), and thus may be important for understanding the timing of the peopling of America. PMID:24258717

  19. Using cosmogenic nuclides to contrast rates of erosion and sediment yield in a semi-arid, arroyo-dominated landscape, Rio Puerco Basin, New Mexico

    USGS Publications Warehouse

    Bierman, P.R.; Reuter, J.M.; Pavich, M.; Gellis, A.C.; Caffee, M.W.; Larsen, J.

    2005-01-01

    Analysis of in-situ-produced 10Be and 26Al in 52 fluvial sediment samples shows that millennial-scale rates of erosion vary widely (7 to 366 m Ma-1) through the lithologically and topographically complex Rio Puerco Basin of northern New Mexico. Using isotopic analysis of both headwater and downstream samples, we determined that the semi-arid, Rio Puerco Basin is eroding, on average, about 100 m Ma-1. This rapid rate of erosion is consistent with estimates made using other techniques and is likely to result from a combination of easily eroded lithologies, sparse vegetation, and monsoon-dominated rainfall. Data from 331 stream water samples collected by the US Geological Survey between 1960 and 1995 are consistent with basin-wide, average chemical denudation rates of only about 1??4 m Ma-1; thus, the erosion rates we calculate may be considered rates of sediment generation because physical weathering accounts for almost 99 per cent of mass loss. The isotopic data reveal that sediment is generally well mixed downstream with the area-weighted average sediment generation rate for 16 headwater samples (234 ton km-2 a-1 for basin area 170 to 1169 km2) matching well that estimated from a single sample collected far downstream (238 ton km-2 a-1, basin area = 14 225 km2). A series of 15 samples, collected from an arroyo wall and representing deposition through the late Holocene, indicates that 10Be concentration in sediment delivered by the fluvial system has not changed appreciably over the last 1200 years despite at least two cycles of arroyo cutting and filling. Other samples (n = 21) were collected along the drainage network. Rio Puerco erosion rates scale directly with a variety of metrics describing vegetation, precipitation, and rock erodibility. Using the headwater basins for calibration, the erosion rates for both the downstream samples and also the data set as a whole, are best modelled by considering a combination of relief and vegetation metrics, both of which co

  20. Migration of As, Hg, Pb, and Zn in arroyo sediments from a semiarid coastal system influenced by the abandoned gold mining district at El Triunfo, Baja California Sur, Mexico.

    PubMed

    Marmolejo-Rodríguez, Ana Judith; Sánchez-Martínez, Martha Alicia; Romero-Guadarrama, Juan Armando; Sánchez-González, Alberto; Magallanes-Ordóñez, Víctor René

    2011-08-01

    Extensive waste deposits (tailings) and ash from the ignition oven of the abandoned gold mine of mining district El Triunfo (MD-ET) in Baja California Sur, Mexico have released trace elements into the sediments of the Hondo-Las Gallinas-El Carrizal arroyo, which connects to the Pacific Ocean through an evaporitic basin. Migration of these elements through the arroyo is mainly caused by winds or tropical hurricanes that occur sporadically during the summer and cause the otherwise dry arroyo to overflow. To evaluate the concentration and distribution of the elements As, Hg, Pb, and Zn along the 48 km arroyo, surface sediments were collected from 26 sites, ranging from close to the MD-ET to the mouth of the arroyo at the Pacific Ocean. Concentrations in tailings and ash were for As 8890 and 505 000 mg kg(-1); for Hg 0.336 and 54.9 mg kg(-1); for Pb 92,700 and 19,300 mg kg(-1); and for Zn 49,600 and 1380 mg kg(-1). The average of the Normalized Enrichment Factor (Av-NEF) in surface sediments, calculated using background levels, indicates that the sediments are severely contaminated with As and Zn (Av-NEF = 22), Pb (Av-NEF = 24) and with a moderate contamination of Hg (Av-NEF = 7.5). The anthropogenic influence of those elements is reflected in the arroyo sediments as far as 18 km away from the MD-ET, whereas the samples closest to the discharge into the Pacific Ocean show a natural to moderate enrichment for As and Zn and low or no enrichment for Hg and Pb. A principal components analysis identified four principal components that explained 90% of the total variance. Factor 1 was characterized by a high positive contribution of the anthropogenic source elements, especially As, Pb, and Zn (37%), whereas Factor 2 was strongly correlated with the oxy-hydroxides of Fe and Mn (27%). Factor 3 was correlated with Li (16%) and Factor 4 with Al (10%), which indicates more than one source of lithogenic composition, though they played a minor role in the distribution of the

  1. Magnetostratigraphy and Paleomagnetism of the Plio-Pleistocene Arroyo Diablo and Borrego Formations in the Borrego Badlands, western Salton Trough, CA

    NASA Astrophysics Data System (ADS)

    Housen, B. A.; Dorsey, R. J.

    2010-12-01

    We report results obtained from a stratigraphic and paleomagnetic study of Plio-Pleistocene sedimentary rocks in the Borrego Badlands, E of Borrego Springs, CA. The Borrego Badlands are bordered by dextral strike slip faults of the San Jacinto fault zone (Clark fault to the NE, Coyote Creek fault to the SW), and is also cut by several NE-striking sinistral faults (linked antithetically to the Coyote Creek and Clark faults), the largest of which is the Inspiration Point fault. Our work focuses on deposits of the Palm Spring Group, including Pliocene fluvial/deltaic sandstones of the Arroyo Diablo Formation and Plio-Pleistocene lacustrine mudstones of the Borrego Formation. We collected a suite of 54 paleomagnetic sample sites from a 2500 m thick section of the Borrego Badlands (3rd Wash, Hills of the Moon Wash, and Rainbow Wash), from the upper part of the Arroyo Diablo Formation to the contact between the Borrego Formation and overlying Ocotillo Formation. This section is correlated to the upper Borrego and Ocotillo formations in Beckman Wash, located NW of here on the NW side of the Inspiration Point fault, allowing us to use the previous magnetostratigraphy of Lutz et al (2006) as a tie point for this section. Sample sites were spaced at 15 to 100 m, and 5 to 8 samples were collected from each site. Samples were thermally demagnetized using steps from 80 to 690 C, and two magnetization components were observed from 53 of the sites. A total of 49 sites had well-defined second-removed components and site mean directions that were robust (k>10). The combined mean of these 49 sites is D = 35, I = 41, α95 = 7.5. We identify 8 polarity zones in this section, ranging from near the base of the Gauss magnetochron to the upper part of the Matuyama chron, including the Mammoth, Kaena, and Olduvai subchrons. The contact between the Arroyo Diablo and Borrego formations is estimated to be ~2.9 Ma. Sediment-accumulation rates are relatively rapid and vary between 0.7 and 1

  2. Can erosion control structures in large dryland arroyo channels lead to resilient riparian and cienega restoration? Observations from LiDAR, monitoring and modeling at Rancho San Bernardino, Sonora, MX

    NASA Astrophysics Data System (ADS)

    DeLong, S.; Henderson, W. M.

    2012-12-01

    The use of erosion control structures to mitigate or even reverse erosion and to restore ecological function along dryland channels (arroyos and gullies) has led to a long list of both successful and failed restoration efforts. We propose that successful implementation of "engineering" approaches to fluvial restoration that include in-channel control structures require either a quantitative approach to design (by scientists and engineers), or intimate on-the-ground knowledge, local observation, and a commitment to adapt and maintain restoration efforts in response to landscape change (by local land managers), or both. We further propose that the biophysical interactions among engineering, sedimentation, flood hydrology and vegetation reestablishment are what determine resilience to destructive extreme events that commonly cause erosion control structure failure. Our insights come from comprehensive monitoring of a remarkable experiment underway at Ranch San Bernardino, Sonora, MX. At this site, private landowners are working to restore ecosystem function to riparian corridors and former cieñega wetlands using cessation of grazing; vegetation planting; upland grass restoration; large scale rock gabions (up to 100 m wide) to encourage local sediment deposition and water storage; and large earthen berms (up to 900 m wide) with cement spillways that form reservoirs that fill rapidly with water and sediment. Well-planned and managed erosion control structures have been used elsewhere successfully in smaller gully networks, but we are unaware of a comparable attempt to use gabions and berms for the sole purpose of ecological restoration along >10 km of arroyo channels draining watersheds on the order of ~400 km2 and larger. We present an approach to monitoring the efficacy of arroyo channel restoration using terrestrial and airborne LiDAR, remote sensing, streamflow monitoring, shallow groundwater monitoring, hydrological modeling and field observation. Our methods

  3. Geological, hydrological, and biological issues related to the proposed development of a park at the confluence of the Los Angeles River and the Arroyo Seco, Los Angeles County, California

    USGS Publications Warehouse

    Land, Michael; Trenham, Peter C.; Ponti, Daniel J.; Reichard, Eric G.; Tinsley, John C., III; Warrick, Jonathan A.; Meyer, Robert W.

    2005-01-01

    A new park is being considered for the confluence of the Los Angeles River and the Arroyo Seco in Los Angeles County, California. Components of the park development may include creation of a temporary lake on the Los Angeles River, removal of channel lining along part of the Arroyo Seco, restoration of native plants, creation of walking paths, and building of facilities such as a boat ramp and a visitor center. This report, prepared in cooperation with the Mountains Recreation and Conservancy Authority, delineates the geological, hydrological, and biological issues that may have an impact on the park development or result from development at the confluence, and identifies a set a tasks to help address these science issues. Geologic issues of concern relate to surface faulting, earthquake ground motions, liquefaction, landsliding, and induced seismicity. Hydrologic issues of concern relate to the hydraulics and water quality of both surface water and ground water. Biological issues of concern include colonization-extinction dynamics, wildlife corridors, wildlife reintroduction, non-native species, ecotoxicology, and restoration of local habitat and ecology. Potential tasks include (1) basic data collection and follow-up monitoring, and (2) statistical and probabilistic analyses and simulation modeling of the seismic, hydraulic, and ecological processes that may have the greatest impact on the park. The science issues and associated tasks delineated for the proposed confluence park will also have transfer value for river restoration in other urban settings.

  4. TENDENCIA DE LA TUBERCULOSIS EN LA REGIÓN SANITARIA V DE LA PROVINCIA DE BUENOS AIRES, AÑOS 2000–2011

    PubMed Central

    CHIRICO, CRISTINA; SANJURJO, MYRIAM; IRIBARREN, SARAH; APPENDINO, ANDREA; ZERBINI, ELSA; ETCHEVARRIA, MIRTA

    2016-01-01

    El objetivo del presente trabajo fue analizar la situación epidemiológica de la tuberculosis (TB) en la Región Sanitaria V (RSV), provincia de Buenos Aires. El estudio de tendencia permitió conocer un valor promedio de las variaciones de la tasa de incidencia (TI), calculadas por regresión lineal simple y expresadas como variación anual promedio (VAP). Se analizaron el número de casos notificados y TI por 100 000 habitantes de todas las formas de TB, los casos de TB pulmonar (TBP) y TBP confirmados por bacteriología, total casos por grupos de edad: 0 – 14; 15 – 29 y mayores de 64 años, entre el 1° de enero de 2000 al 31 de diciembre de 2011. La declinación de la TI fue menor al 5% para todas las formas de TB e inferior en las TBP confirmadas bacteriológicamente. Los casos de TBP y TI más elevadas, se concentraron en el grupo de 15 a 29 años, con tendencia estable o ligeramente ascendente de la TI en la TBP bacilífera. El mismo comportamiento presentaron los casos de TBP infantil con confirmación bacteriológica. La mayor velocidad de descenso en la TI de la TBP se produjo en este grupo de edad, mientras que en mayores de 64 años, el descenso fue sostenido en el tiempo. La TB persiste como un riesgo de salud en la RSV, con casos en edades jóvenes, por lo que sigue siendo necesario fortalecer el control de la TB en esta región. PMID:26117604

  5. [Salmonella: its incidence in waters of the Zaimán arroyo].

    PubMed

    Benassi, F O; Martínez Vázquez, F; Eiguer, T

    1983-01-01

    The present work is the initial stage of a project to determine the causes and degree of pollution of the Zaiman creek waters, which flow through wide suburban areas of Posadas, Argentina. The research was focused on the presence of Salmonella serotypes, pathogenic microorganisms probably responsible for most waterborne disease outbreaks. In addition, the N.M.P./100 ml (Most Probable Number) of total coliform organisms was determined in samples collected from points near cold storage plant and slaughterhouse, both to show the pollution effect of industrial discharges. So far, 35 sampling operations have been carried out in representative geographic points. The methodology for Salmonella consisted in applying concentration technics for waterborne pathogens, followed by an enrichment procedure performed by incubating samples in Dulcitol Selenite and Tetrathionate (Muller-Kauffman) broths at 41.5 degrees C during 25 hours. Typical, well-isolated Salmonella-like colonies were obtained by streaking duplicate plates of E.M.B. Agar (Eosin Methylene Blue), Brilliant Green Agar and Bismuth Sulphite Agar. Suspected colonies were classified by 10 biochemical reactions and further verified by serological identification, performed at the National Institute of Microbiology "Carlos Malbrán". The methodology followed for the determination of total coliforms was the one described in the American Water Standards. Salmonella serotypes were isolated in 46% of the examined samples. Isolation efficiency of culture media is shown. First isolations of Salmonella abaetetuba and S. saphra are reported. Most serotypes were isolated from sampling points down-stream from the industrial plant. Zaimán creek waters were classified as No 4 of W.H.O (World Health Organization) stream waters classification, except during heavy rain periods in which they ranked as No 3. PMID:6336566

  6. 76 FR 7245 - Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for the Arroyo Toad

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-09

    ..., 1994 (59 FR 64859); the final critical habitat rule published in the Federal Register on February 7, 2001 (66 FR 9414); the final revised critical habitat rule published in the Federal Register on April 13, 2005 (70 FR 19562); and the proposed revised critical habitat rule published in the...

  7. Chemical quality of sediment cores from the Laguna Madre, Laguna Atascosa and Arroyo Colorado, Texas

    USGS Publications Warehouse

    Van Metre, Peter C.

    1999-01-01

    Many contaminants introduced into the environment by human activities are hydrophobic, meaning they are relatively insoluble in water and, thus, are associated primarily with sediments. These contaminants include the organochlorine pesticides DOT and chlordane, polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) from industrial facilities and urban areas, and heavy metals such as arsenic, lead, mercury, and zinc. Understanding the occurrence of these contaminants in the environment requires sampling the sediments where the contaminants might be detected.

  8. Evaluation of Background Concentrations of Contaminants in an Unusual Desert Arroyo Near a Uranium Mill Tailings Disposal Cell - 12260

    SciTech Connect

    Bush, Richard P.; Morrison, Stan J.

    2012-07-01

    The U.S. Department of Energy (DOE) Office of Legacy Management (LM) manages 27 sites that have groundwater containing uranium concentrations above background levels. The distal portions of the plumes merge into background groundwater that can have 50 μg/L or more uranium. Distinguishing background from site-related uranium is often problematic, but it is critical to determining if remediation is warranted, establishing appropriate remediation goals, and evaluating disposal cell performance. In particular, groundwater at disposal cells located on the upper Cretaceous Mancos Shale may have relatively high background concentrations of uranium. Elevated concentrations of nitrate, selenium, and sulfate accompany the uranium. LM used geologic analogs and uranium isotopic signatures to distinguish background groundwater from groundwater contaminated by a former uranium processing site. The same suite of contaminants is present in groundwater near former uranium processing sites and in groundwater seeps emanating from the Mancos Shale over a broad area. The concentrations of these contaminants in Many Devils Wash, located near LM's Shiprock disposal cell, are similar to those in samples collected from many Mancos seeps, including two analog sites that are 8 to 11 km from the disposal cell. Samples collected from Many Devils Wash and the analog sites have high AR values (about 2.0)-in contrast, groundwater samples collected near the tailings disposal cell have AR values near 1.0. These chemical signatures raise questions about the origin of the contamination seeping into Many Devils Wash. (authors)

  9. Characterization of streamflow, salinity, and selenium loading and land-use change in Montrose Arroyo, western Colorado, from 1992 to 2013

    USGS Publications Warehouse

    Richards, Rodney J.; Moore, Jennifer L.

    2015-01-01

    Land use was characterized for 1992, 2002, and 2009 for site MA3. The common land-use change in the MA3 subwatershed was a conversion from previously irrigated agricultural land to urban land use. The MA3 subwatershed had 124 acres of irrigated land use converted to urban land use and 27.1 acres of unirrigated desert converted to urban land use from 1992 to 2009. Consistent with findings in previous land-use change reports, salinity and dissolved-selenium loading at site MA3 showed significant decreases as irrigated land was converted to urban land use.

  10. Water Resources Data for California, Water Year 1987. Volume 2. Pacific Slope Basins from Arroyo Grande to Oregon State Line Except Central Valley

    USGS Publications Warehouse

    Anderson, S.; Markham, K.L.; Shelton, W.F.; Trujillo, L.F.

    1988-01-01

    Water resources data for the 1987 water year for California consist of records of stage, discharge, and water quality of streams; stage and contents in lakes and reservoirs; and water levels and water. quality in wells. Volume 2 contains discharge records for 123 gaging stations; stage and contents for 7 lakes and reservoirs; and water quality for 29 stations. Also included are 1 partial-record station and 24 water-quality partial-record stations, These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in California.

  11. Water Resources Data for California, Water Year 1984; Volume 2. Pacific Slope Basins from Arroyo Grande to Oregon State Line except Central Valley

    USGS Publications Warehouse

    Anderson, S.; Markham, K.L.; Piro, V.; Shelton, W.F.; Grillo, D.A.

    1985-01-01

    Water resources data for the 1984 water year for California consists of records of stage, discharge, and water quality of streams; stage and contents in lakes and reservoirs; and water levels and water quality in wells. Volume 2 contains discharge records for 132 gaging stations; stage and contents for 18 lakes and reservoirs; water quality for 11 stations; water levels for 9 observation wells. Also included are 2 low-flow partial-record stations and 19 water-quality partial-record stations. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in California.

  12. Water Resources Data, California, Water Year 1990. Volume 2. Pacific Slope Basins from Arroyo Grande to Oregon State Line except Central Valley

    USGS Publications Warehouse

    Shelton, W.F.; Trujillo, L.F.; Markham, K.L.; Palmer, J.R.

    1991-01-01

    Water resources data for the 1990 water year for. California consist of records of stage, discharge, and water quality of streams; stage and contents in lakes and reservoirs; and water levels and water quality in wells. Volume 2 contains discharge records for 125 streamflow-gaging stations and 1 low-flow partial-record station; stage and contents for 7 lakes and reservoirs; precipitation records for 4 stations; and water-quality records for 29 streamflow-gaging stations and 10 water-quality partial-record stations. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in California.

  13. Water Resources Data for California, Water Year 1988. Volume 2. Pacific Slope Basins from Arroyo Grande to Oregon State Line Except Central Valley

    USGS Publications Warehouse

    Markham, K.L.; Palmer, J.R.; Shelton, W.F.; Trujillo, L.F.

    1989-01-01

    Water resources data for the 1988 water year for California consist of records of stage, discharge, and water quality of streams; stage and contents in lakes and reservoirs; and water levels and water quality in wells. Volume 2 contains discharge records for 123 gaging stations; stage and contents for 7 lakes and reservoirs; and water quality for 38 stations. Also included is l low-flow partial-record station and 22 water-quality partial-record stations. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in California.

  14. Water Resources Data for California, Water Year 1983 Volume 2. Pacific Slope Basins from Arroyo Grande to Oregon State Line except Central Valley

    USGS Publications Warehouse

    Anderson, S.; Markham, K.L.; Piro, V.; Shelton, W.F.; Grillo, D.A.

    1985-01-01

    Hater resources data for the 1983 water year for California consists of records of stage, discharge, and water quality of streams; stage and contents in lakes and reservoirs; and water levels and water quality in wells. Volume 2 contains discharge records for 145 gaging stations; stage and contents for 19 lakes and reservoirs; water quality for 17 stations; water levels for 67 observation wells. Also included are 2 low-flow partial-record stations and 18 water-quality partial-record stations. These data represent that part of the National Hater Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in California.

  15. Water Resources Data, California, Water Year 1989. Volume 2. Pacific Slope Basins from Arroyo Grande to Oregon State Line except Central Valley

    USGS Publications Warehouse

    Palmer, J.R.; Shelton, W.F.; Trujillo, L.F.; Markham, K.L.

    1990-01-01

    Water resources data for the 1989 water year for California consist of records of stage, discharge, and water. quality of streams; stage and contents in lakes and reservoirs; and water levels and water quality in wells. Volume 2 contains discharge records for 127 gaging stations, stage and contents for 7 lakes and reservoir and water quality for 32 stations. Also included is 1 low-flow partial-record station and 22 waterquality partial-record stations. These data represent that part of the National Water Data System operated by the u.s. Geological Survey and cooperating State and Federal agencies in California.

  16. Water Resources Data for California, Water Year 1985. Volume 2. Pacific Slope Basins from Arroyo Grande to Oregon State Line except Central Valley

    USGS Publications Warehouse

    Anderson, S.; Markham, K.L.; Trujillo, L.F.; Shelton, W.F.; Grillo, D.A.

    1987-01-01

    Water resources data for the 1985 water year for California consists of records of stage, discharge, and water quality of streams; and stage and contents in lakes and reservoirs; and water levels and water quality in wells. Volume 2 contains discharge records for 133 gaging stations; stage and contents for 9 lakes and reservoirs; and water quality for 34 stations. Also included are 3 low-flow partial-record stations and 1 water-quality partial-record stations. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in California.

  17. Water Resources Data for California, Water Year 1986. Volume 2. Pacific Slope Basins from Arroyo Grande to Oregon State Line except Central Valley

    USGS Publications Warehouse

    Anderson, S.; Markham, K.L.; Shelton, W.F.; Trujillo, L.F.; Grillo, D.A.

    1988-01-01

    Water resources data for the 1986 water year for California consist of records of stage, discharge, and water quality of streams; stage and contents in lakes and reservoirs; and water levels and water quality in wells. Volume 2 contains discharge records for 132 gaging stations; stage and contents for 11 lakes and reservoirs; and water quality for 32 stations. Also included are 4 partial-record stations and 24 water-quality partial-record stations. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in California.

  18. Water Resources Data for California, Water Year 1982, Volume 2. Pacific Slope Basins from Arroyo Grande to Oregon State Line except Central Valley

    USGS Publications Warehouse

    Markham, K.L.; Piro, V.; Shelton, W.F.; Weston, M.W., Jr.

    1984-01-01

    Water resources data for the 1982 water year for California consists of records of stage, discharge, and water quality of streams; stage and contents in lakes and reservoirs; and water levels and water quality in wells. Volume 2 contains discharge records for 153 gaging stations; stage and contents for 12 lakes and. reservoirs; water quality for 19 stations; water levels for 73 observation wells. Also included are 1 low-flow partial-record station and 13 water-quality partial-record stations. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in California.

  19. CONTEXTUAL VIEW FROM HOTEL; HAMILTON BUNGALOW IN FOREGROUND; BUNGALOW NO. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    CONTEXTUAL VIEW FROM HOTEL; HAMILTON BUNGALOW IN FOREGROUND; BUNGALOW NO. 3 DIRECTLY BEHIND; HINDS & CONNER AND "A" BUNGALOWS IN REAR. VISTA DEL ARROYO HOTEL ON RIGHT - Vista del Arroyo Hotel, 125 South Grand Avenue, Pasadena, Los Angeles County, CA

  20. Constraining the Paleogene of South America: Magnetostratigraphy and paleoclimate proxy records from Cerro Bayo (Provincia de Salta, Argentina)

    NASA Astrophysics Data System (ADS)

    Hyland, E.; Cotton, J. M.; Sheldon, N. D.

    2012-12-01

    Records of rapid climatic and ecological shifts in the past are crucial for understanding global systems and for predicting future impacts of climate change. Transient and broad scale hyperthermal events during the Paleogene, such as the Paleocene-Eocene Thermal Maximum (PETM) and Early Eocene Climatic Optimum (EECO), have been studied extensively through both marine records and a significant terrestrial record from North America. Despite this, little evidence exists from the climatic and ecological histories of other major landmasses, which limits the effectiveness of global climate response predictions. Here we present an integrated paleoenvironmental reconstruction of the early Paleogene from a site in central South America (Cerro Bayo, Argentina), including a new magnetostratigraphic age model, pedological and sedimentological interpretation, whole rock geochemical climate proxies, isotopic environmental proxies, and microfloral assemblages. Cerro Bayo is a 235-meter terrestrial section that exposes the Tunal, Mealla, and Maiz Gordo Formations, and based on magnetostratigraphic interpolation spans roughly 58—50 Mya, including both the PETM and EECO events. These formations are composed primarily of reddish sandstone and siltstone, much of which exhibits features characteristic of a moderate degree of pedogenesis (i.e., Inceptisols and Alfisols). High-resolution climate proxies derived from paleosol geochemical compositions highlight rapid increases in mean annual temperature (>5°C) and precipitation (>300 mm yr-1) during the PETM, as well as more gradual increasing temperature and precipitation trends leading up to the EECO. Carbon isotope stratigraphy through the section also indicates a sizable negative excursion (~4‰) during the PETM, and generally positive isotopic trends during the early Eocene. Phytolith biostratigraphy also details changes in local vegetation composition during climatic events that corresponds to similar patterns seen in terrestrial records from North America. Based on this integrated record from central South America it is likely that temperate latitudes in both hemispheres experienced similar magnitude and expression of climatic and ecological changes as a result of hyperthermal events (PETM, EECO) in the early Paleogene.

  1. 6. PART 3 OF 3 PART PANORAMA WITH NOS. CA265J4 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. PART 3 OF 3 PART PANORAMA WITH NOS. CA-265-J-4 AND CA-265-J-5 OF FIGUEROA STREET AND LOS ANGELES RIVER VIADUCTS. NOTE ARROYO SECO CHANNEL ENTERING LOS ANGELES RIVER UNDER RAILROAD TRESTLE AT RIGHT. LOOKING 268°W. - Arroyo Seco Parkway, Figueroa Street Viaduct, Spanning Los Angeles River, Los Angeles, Los Angeles County, CA

  2. 12. DETAIL VIEW OF STRUCTURE, FROM BELOW. VIEW OF THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. DETAIL VIEW OF STRUCTURE, FROM BELOW. VIEW OF THE PARKER-MAYBERRY BRIDGE AND PART OF THE STRUCTURE OF THE COLORADO STREET BRIDGE, SEEN FROM THE ARROYO SECO BELOW THE COLORADO STREET BRIDGE - Colorado Street Bridge, Spanning Arroyo Seco at Colorado Boulevard, Pasadena, Los Angeles County, CA

  3. Stream capture and piracy recorded by provenance in fluvial fan strata

    NASA Astrophysics Data System (ADS)

    Mikesell, Leslie R.; Weissmann, Gary S.; Karachewski, John A.

    2010-03-01

    Stream capture and piracy in tectonically active regions have been described in geomorphic systems worldwide; however, few studies show the influence stream capture has on the rock record. We present an analysis of fluvial fan stratigraphy that developed as a result of multiple stream capture events, building a complex stratigraphic succession beneath the Lawrence Livermore National Laboratory (LLNL), California. The LLNL site is located in the southeast portion of the tectonically active Livermore Basin, a transpressional basin in the California Coast Ranges. Geomorphic evidence for this stream capture include: (1) the Arroyo Seco enters the basin from the south through an uplifted fault block, (2) south of this fault block lies an abandoned Arroyo Seco fluvial fan, (3) north of the fault block, in the Livermore Basin, Arroyo Seco built a 7-km 2 fluvial fan, apparently forcing the Arroyo Las Positas, a smaller stream that enters the basin from the east, northward around the Arroyo Seco fan, and (4) a knickpoint exists near the point of capture on Arroyo Seco. Stratigraphic evidence reflecting this shift in the Arroyo Seco position into the Livermore Basin was evaluated through a provenance study of 215 gravel units from 34 boreholes spaced evenly over the 2.6 km 2 LLNL site. The Arroyo Seco derives its sediment from both the Jurassic-Cretaceous Franciscan Assemblage and the Altamont Hills (which are comprised of Mesozoic Great Valley Group and Tertiary continental sediments). The Arroyo Las Positas drains only the Altamont Hills and thus lacks the Franciscan Assemblage-derived clasts. The origin of the individual gravel units was determined by the percentage of Franciscan Assemblage indicator pebbles (red chert, green chert and blueschist) in the samples. Through this analysis, we determined that high-percentage Franciscan Assemblage-derived clasts were present below a depth of approximately 35 m below the surface, low-percentage Franciscan Assemblage

  4. Methylmercury poisoning

    MedlinePlus

    ... Rusyniak DE, Arroyo A, Froberg B, Furbee B. Heavy metals. In: Vincent J-L, Abraham E, Moore FA, ... 2011:chap 178. Velez LI, O'Connell EJ. Heavy metals. In: Marx JA, Hockberger RS, Walls RM, et ...

  5. Merbromin poisoning

    MedlinePlus

    ... Poisoning and Drug Overdose . 4th ed. Philadelphia, PA: Elsevier Saunders; 2007:chap 71. Linakis JG, Skarbek-Borowska S. ... Poisoning and Drug Overdose . 4th ed. Philadelphia, PA: Elsevier Saunders; 2007:chap 18. Rusyniak DE, Arroyo A, ...

  6. 40 CFR 81.355 - Puerto Rico.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Adjuntas Municipio Aguada Municipio Aguadilla Municipio Aguas Buenas Municipio Aibonito Municipio Anasco... Aguada Municipio Aguadilla Municipio Aguas Buenas Municipio Aibonito Municipio Anasco Municipio Arecibo... Municipio Aguas Buenas Municipio Aibonito Municipio Añasco Municipio Arecibo Municipio Arroyo...

  7. 40 CFR 81.355 - Puerto Rico.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Adjuntas Municipio Aguada Municipio Aguadilla Municipio Aguas Buenas Municipio Aibonito Municipio Anasco... Aguada Municipio Aguadilla Municipio Aguas Buenas Municipio Aibonito Municipio Anasco Municipio Arecibo... Municipio Aguas Buenas Municipio Aibonito Municipio Añasco Municipio Arecibo Municipio Arroyo...

  8. 22. Photocopy of photograph (original print at Gage Canal Company ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. Photocopy of photograph (original print at Gage Canal Company Office), photographer and date unknown. 'FLUME NO. 9, 'GAGE CANAL SYSTEM,' RIVERSIDE, CAL.' VIEW OF FLUME OVER TEQUESQUITE ARROYO. - California Citrus Heritage Recording Project, Riverside, Riverside County, CA

  9. Depths of channels in the area of the San Juan Basin Regional Uranium Study, New Mexico, Colorado, Arizona, and Utah

    USGS Publications Warehouse

    Cooley, Maurice E.

    1979-01-01

    During December 1977 and January 1978 about 280 measurements were made of the depths of channels (arroyos) more than 6 feet deep in the San Juan Basin area. More than half of the measurements were made at sites where channel depths had been previously measured Between 1964 and 1969. Some channels in the western part of the basin had Been re-measured in 1969 and in 1971. The principal areas Being dissected by arroyos are near highlands along the margins of the Basin and in uplands in the northeastern part of the Basin. The most severe dissection by arroyos and the deepest arroyos--commonly Between 40 and 60 feet deep--are in the southeastern part of the Basin. Dissection By arroyos is least in the central part of the Basin near the Chaco River where most arroyos are less than 10 feet deep. Elsewhere, moderate dissection predominates with most arroyos Between 12 and 40 feet deep. Comparison of measurements made from 1964-71 with those made in 1977-78 shows that more channels in the western San Juan Basin were filling than were downcutting. Downcutting or filling was generally less than 2 feet. About two-fifths of the sites measured showed less than half a foot of downcutting or filling. Maximum downcutting was 4 feet along the Rio San Jose in the southeastern part of the basin. Maximum filling of 7 feet was along the Chaco River at the Chaco Canyon National Monument. Along ii other streams elsewhere in the western part of the basin, channels were filled 3 to 4.5 feet. The few measurements made in the southeastern San Juan Basin indicate that since 1964 downcutting has predominated over filling. Large floods during the summer of 1977 caused some change in channel depths in the southwestern part of the San Juan Basin. Some of the channels appeared to have been filled during the years prior to the cutting that occurred from the 1977 floods. At other places, flood flows aggraded (filled) channels. The rate of erosion and arroyo formation in the entire San Juan Basin is

  10. Relaciones hidrogeologicas y medioambientales entre el mar mediterraneo, El saladar y el acuifero de agua amarga (provincia de alicante). Incidencia de las explotaciones de las desaladoras de alicante I Y II Y medidas correctoras

    NASA Astrophysics Data System (ADS)

    Manteca, Ivan Alhama

    The Agua Amarga coastal aquifer, located in the south of Alicante province, has been subjected to successive anthropogenic actions: salt works activity (1925-1975) and water withdrawal to supply the Alicante I and II desalination plants (since 2003). These interventions have influenced the salinity and the flow regime. Due to the existence of a salt marsh of ecological interest linked to the aquifer, the 'Mancomunidad de los Canales del Taibilla' (agency responsible for the desalination plants) designed a piezometric network for monitoring piezometry and electrical conductivity (in operation since May 2008). Soil humidity and piezometrics levels have been recovered by means of a seawater pouring programme over the salt marsh (since December 2009),which represents the third anthropic intervention. In this memoria, we investigate the Agua Amarga coastal aquifer to develop a physical conceptual model. Firstly, the study area is characterized in relation to climatology, geology, geomorphology and hydrogeology, using published information, describing, in addition, the desalination plants catchment system. Next, based on hydrogeological studies prior to the start up of the desalination plants, the aquifer is characterized: type, lithology, hydraulic parameters, thickness, surface extension, etc. Water quantity relating to rainfall, water withdrawal and pourings over the salt marsh, have been integrated in conjunction with data from monthly piezometric campaigns. In adittion, in order to gain insight into the groundwater mixing processes, chemical and isotope analyses were carried out on meteoric water and groundwater samples taken at different locations. The results were used to elaborate a conceptual physical model and a water budget. As an extension tool to understand processes and assess aquifer management, a 3-D fluid-flow and solute-transport model is designed with SEAWAT. Also, the 2-D physical characterization of scenarios with seawater intrusion and salt flats is presented. Finally, after describing ecological values of the salt marsh, the effect of the seawater pouring programme on aquifer piezometry and salinity is studied, assessing the possibility of applying this pilot scheme to other scenarios.

  11. Simulation of regional-scale groundwater flow in the Azul River basin, Buenos Aires Province, Argentina

    NASA Astrophysics Data System (ADS)

    Varni, Marcelo R.; Usunoff, Eduardo J.

    , suggérant ainsi que la description par le modèle des relations rivière-nappe est correcte. Resumen Se ha utilizado el modelo MODFLOW, del Servicio Geológico de los Estados Unidos, para simular el flujo de agua subterránea en la cuenca del arroyo del Azul, Provincia de Buenos Aires, Argentina, con el objeto de evaluar el modelo hidrogeológico conceptual. Los niveles hidráulicos simulados ajustan satisfactoriamente con los niveles observados. Los resultados de la simulación indican que: (1) la recarga no es uniforme, sino que puede caracterizarse con tres zonas en las que sus valores decrecen en la medida en que decrece la pendiente, que guarda similitud con la distribución de suelos y características geomorfológicas y (2) la evapotranspiración sería mayor que la estimada en estudios previos, en los que se utilizó el método de Thornthwaite-Mather. La evapotranspiración estimada mediante la presente simulación concuerda con resultados de varios estudios independientes en la región. Respecto de la relación acuífero-río, existe un muy buen ajuste entre los aportes del acuífero al río simulados y los valores históricos de caudal base.

  12. Late Glacial-Holocene climatic transition record at the Argentinian Andean piedmont between 33-34° S

    NASA Astrophysics Data System (ADS)

    Mehl, A. E.; Zárate, M. A.

    2013-10-01

    The Arroyo La Estacada (~33°28' S, 69°02' W), eastern Andean piedmont of Argentina, cuts through an extensive piedmont aggradational unit composed of a dominant late Pleistocene-early Holocene (LP-EH) alluvial sequence including several paleosols. The arroyo sedimentary record exhibits a paleosol developed affecting the topmost part of likely Lateglacial aeolian deposits aggraded into a floodplain environment by the end of the late Pleistocene. The paleosol shows variable grade of development in the outcrops along the arroyo probably in relation to fluvial valley paleotopography. Organic matter humification, carbonate accumulation and redox processes were the dominant processes associated with paleosol formation. By the early Holocene, when the formation of the paleosol ended, alluvial aggradation renewed and a higher frequency of flooding events could have affected the arroyo's floodplain environment. A period of relative landscape stability in the Arroyo La Estacada basin is inferred from the paleosol developed by the LP-EH transition in response to a climatic amelioration in the Andes cordillera piedmont after the Late Glacial arid conditions. The renewal of early Holocene alluvial aggradation was probably influenced by the South American Monsoon and resulted in a change in the sedimentary dynamics of the arroyo. The analyzed Late Glacial-Holocene alluvial record of the Andean piedmont constitutes a suitable record of the LP-EH climatic transition at the extra Andean region of Argentina. It is in agreement with regional paleoclimatic evidence along the southern tip of the South American continent, where other sedimentary sequences record similar late Quaternary paleoenvironmental changes over both fluvial and interfluvial areas.

  13. 6. SITE OVERVIEW. PART 1 OF 6 PART PANORAMA WITH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. SITE OVERVIEW. PART 1 OF 6 PART PANORAMA WITH NOS. CA-265-7 TO CA-265-11. ARROYO SECO PARKWAY AS SEEN FROM RADIO TOWER HILL (APPROXIMATELY 34° 5' BY 118° 12'30" ON USGS LOS ANGELES QUADRANGLE). PART 1 SHOWS GRAND VIEW POINT AT RIGHT REAR (LOCATION OF CAMERA POSITION FOR PHOTOGRAPHS NOS. 265-1 TO CA-265-5) AND FIGUEROA VIADUCT OVERCROSSING; DOWNTOWN LOS ANGELES IS AT LEFT REAR. LOOKING 234° SW. - Arroyo Seco Parkway, Los Angeles to Pasadena, Los Angeles, Los Angeles County, CA

  14. 4. PART 1 OF 3 PART PANORAMA WITH NOS. CA265J5 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. PART 1 OF 3 PART PANORAMA WITH NOS. CA-265-J-5 AND CA-265-J-6 OF FIGUEROA STREET AND LOS ANGELES RIVER VIADUCTS. NOTE TUNNEL NO.1 NORTH PORTAL AT LEFT REAR. LOOKING 268°W. - Arroyo Seco Parkway, Figueroa Street Viaduct, Spanning Los Angeles River, Los Angeles, Los Angeles County, CA

  15. 12. FIGUEROA STREET TUNNEL NO.1, SOUTH PORTAL.SEEN FROM ABOVE NORTH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. FIGUEROA STREET TUNNEL NO.1, SOUTH PORTAL.SEEN FROM ABOVE NORTH PORTAL OF TUNNEL NO. 2. LOOKING 140N. - Figueroa Street Tunnels, Mileposts 24.90, 25.14, 25.28, & 25.37 on Arroyo Seco Parkway, Los Angeles, Los Angeles County, CA

  16. 8. FIGUEROA STREET TUNNEL NO. 2, SOUTH PORTAL SEEN FROM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. FIGUEROA STREET TUNNEL NO. 2, SOUTH PORTAL SEEN FROM ABOVE NORTH PORTAL OF TUNNEL NO. 3. LOOKING 12°N. - Figueroa Street Tunnels, Mileposts 24.90, 25.14, 25.28, & 25.37 on Arroyo Seco Parkway, Los Angeles, Los Angeles County, CA

  17. 9. DETAIL VIEW OF DESIGN ELEMENT ON TUNNEL NO. 2, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. DETAIL VIEW OF DESIGN ELEMENT ON TUNNEL NO. 2, SOUTH PORTAL. LOOKING 60° ENE. - Figueroa Street Tunnels, Mileposts 24.90, 25.14, 25.28, & 25.37 on Arroyo Seco Parkway, Los Angeles, Los Angeles County, CA

  18. Effects of Soldiers' Deployment on Children's Academic Performance and Behavioral Health. Monograph

    ERIC Educational Resources Information Center

    Richardson, Amy; Chandra, Anita; Martin, Laurie T.; Setodji, Claude Messan; Hallmark, Bryan W.; Campbell, Nancy F.; Hawkins, Stacy; Grady, Patrick

    2011-01-01

    Long and frequent deployments, with short dwell times in between, have placed stresses on Army children and families already challenged by frequent moves and parental absences. RAND Arroyo Center was asked by the Army to examine the effects of parental deployments on children's academic performance as well as their emotional and behavioral…

  19. 7. FIGUEROA STREET TUNNELS NO. 1 & 2, SOUTH PORTALS. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. FIGUEROA STREET TUNNELS NO. 1 & 2, SOUTH PORTALS. SEEN FROM PARK ROW. LOOKING 8°N. - Figueroa Street Tunnels, Mileposts 24.90, 25.14, 25.28, & 25.37 on Arroyo Seco Parkway, Los Angeles, Los Angeles County, CA

  20. 9. Photocopy of photograph (original print at Riverside Library, Local ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. Photocopy of photograph (original print at Riverside Library, Local History Collection), photographer unknown, October 1916. FORMER 'VICTORIA BRIDGE' (HOWE DECK TRUSS SUPPORTED BY TRESTLE) LOOKING SOUTHWEST, SHOWING STREETCAR AND THATCH-ROOFED, CANTILEVERED PEDESTRIAN PLATFORM - Victoria Bridge, Spanning Tequesquite Arroyo, Riverside, Riverside County, CA

  1. Surface and groundwater quality in the northeastern region of Buenos Aires Province, Argentina

    NASA Astrophysics Data System (ADS)

    Galindo, G.; Sainato, C.; Dapeña, C.; Fernández-Turiel, J. L.; Gimeno, D.; Pomposiello, M. C.; Panarello, H. O.

    2007-04-01

    This work studies the water quality of the Pergamino-Arrecifes River zone in the Rolling Pampa, northeast Buenos Aires Province, Argentina. Temperature, pH, specific conductivity, Na, K, Mg, Ca, SO42-, Cl -, HCO3-, NO3-, Si, Ag, Al, As, B, Ba, Be, Br, Cd, Co, Cr, Cu, Fe, Hg, Li, Mn, Mo, Ni, P, Pb, Se, Tl, U, V, Zn, and the environmental stable δ18O and δ2H isotope ratios were determined in 18 sampling stations. Natural and anthropogenic features influence surface and groundwater quality. Point pollution sources (septic wells and other domestic and farming effluents) increase the nitrate concentration. The values of pH, NO3-, Al, As, B, Fe, and Mn exceed the respective Argentine reference thresholds in different sampling stations for human drinking water; B, Mo, U, and V for irrigation; and V and Zn for cattle consumption.

  2. Survey of Radionuclide Distributions Resulting from the Church Rock, New Mexico, Uranium Mill Tailings Pond Dam Failure

    SciTech Connect

    Weimer, W. C.; Kinnison, R. R.; Reeves, J. H.

    1981-12-01

    An intensive site survey and on-site analysis program were conducted to evaluate the distribution of four radionucliGes in the general vicinity of Gallup, New Mexico, subsequent to the accidental breach of a uranium mill tailings pond dam and the release of a large quantity of tailings pond materials. The objective of this work was to determine the distribution and concentration levels of {sup 210}Pb, {sup 226}Ra, {sup 230}Th, and {sup 238}U in the arroyo that is immediately adjacent to the uranium tailings pond (pipeline arroyo) and in the Rio Puerco arroyo into which the pipeline arroyo drains. An intensive survey between the United Nuclear Corporation (UNC) Church Rock Mill site and the New Mexico-Arizona state border was performed. Sampling locations were established at approximately 500-ft intervals along the arroyo. During the weeks of September 24 through October 5, 1979, a series of samples was collected from alternate sampling locations along the arroyo. The purpose of this collection of samples and their subsequent analysis was to provide an immediate evaluation of the extent and the levels of radioactive contamination. The data obtained from this extensive survey were then compared to action levels which had been proposed by the Nuclear Regulatory Commission and were adapted by the New Mexico Environmental Improvement Division (NMEID) for {sup 230}Th and {sup 226}Ra concentrations that would require site cleanup. The Pacific Northwest Laboratory/Nuclear Regulatory Commission mobile laboratory van was on-site at the UNC Church Rock Mill from September 22, 1979, through December 13, 1979, and was manned by one or more PNL personnel for all but four weeks of this time period. Approximately 1200 samples associated with the Rio Puerco survey were analyzed 1n the laboratory. An additional 1200 samples related to the Rio Puerco cleanup operations which the United Nuclear Corporation was conducting were analyzed on-site in the mobile laboratory. The purpose of

  3. Late Pleistocene and Holocene environmental and climatic conditions in the eastern Andean piedmont of Mendoza (33°-34°S, Argentina)

    NASA Astrophysics Data System (ADS)

    Mehl, A. E.; Zárate, M. A.

    2012-08-01

    The main goal of this paper is to analyze the late Quaternary alluvial record of the Andean piedmont between 33° and 34°S (Mendoza, Argentina) reconstructing the prevailing paleoenvironmental conditions and discussing their regional significance. The analysis was carried out along the outcrops of Arroyo La Estacada and its tributary Arroyo Anchayuyo, complementary sections were described at Arroyo Grande and Arroyo Yaucha. The sedimentological, stratigraphical and geochronological (radiocarbon and OSL dating) results as well as the paleoenvironmental interpretation are presented and discussed on the basis of the geomorphological units identified at the piedmont fluvial systems. Late Quaternary deposits of Arroyo La Estacada compose three main geomorphological units consisting of an extensive aggradational plain, a fill terrace and the present floodplain -which is not analyzed in this contribution-. At the aggradational plain a distal alluvial fan lithofacial association was determined, mainly related to overbank sheet fluid overflows and probably temporary inactive channels of sandy-like braided streams between ˜50 ka BP and the early Holocene. The mid-late Holocene fining upward alluvial sequence of the fill terrace corresponds to a sinuous fluvial system lithofacial association. The mid-to late Holocene alluvial sequence exposed at Arroyo Grande banks shows a fining upward sequence probably related to a sinuous fluvial system lithofacial association. Finally, in the Arroyo Yaucha the upper and lower terraces analyzed in this study record a Late Glacial and Holocene fining upward alluvial sequence of a sinuous fluvial system lithofacial association. The late Pleistocene - early Holocene dynamic of the Andean piedmont documents an interval of alluvial aggradation characterized by the occurrence of sandy systems similar to braided rivers in the distal fan environments. The mid-late Holocene is marked by aggradation in sinuous fluvial systems and by two major

  4. Precise Dating of Flood-Plain Stratigraphy Using Changes in Tree-Ring Anatomy Following Burial

    NASA Astrophysics Data System (ADS)

    Friedman, J. M.; Shafroth, P. B.; Vincent, K. R.; Scott, M. L.; Auble, G. T.

    2001-12-01

    Determination of sediment deposition rates from stratigraphy is typically limited by a scarcity of chronological information. We present a method for precise dating of sedimentary beds based on the change in anatomy of tree rings upon burial. When stems of tamarisk (Tamarix ramosissima)and sandbar willow (Salix exigua) are buried, subsequent annual rings in the buried portions become narrower and vessels within the rings become larger. Observation of these changes can be combined with tree ring counts to determine the year of deposition of sedimentary beds that are at least 10 cm thick. Using a backhoe we dug trenches across the flood plain at three locations along the arroyo of the Rio Puerco, New Mexico. At each cross section we prepared a detailed stratigraphic description and excavated several tamarisks to depths as great as 5 meters. From each excavated tree we cut and sanded 10-50 slabs for tree-ring analysis. We cross-dated slabs within and between plants and used the burial signature in the tree rings to date all sedimentary beds in the stratigraphic profile near each plant. We then used the trench stratigraphy to convert depths of sediment deposition around individual trees to areas of deposition in the cross section. In the lower Rio Puerco introduction of tamarisk in 1926 occurred just prior to the beginning of channel narrowing and arroyo filling. Thus the tamarisks record a process of channel change to which they may have contributed. Aggradation has not been synchronous along the lower arroyo. For example, near Highway 6 and Belen, the flood plain has aggraded more than 2 m since 1970, while there has been little aggradation downstream at Bernardo. Much of the sediment deposition in levies at Highway 6 occurred during a flood in 1988. Future work will document longitudinal variation in the arroyo so that we can convert areas of sediment deposition in cross sections to volumes in the arroyo.

  5. Sediment Budgets the 'Old Fashioned' way for two Subbasins of the Rio Puerco, Central New Mexico

    NASA Astrophysics Data System (ADS)

    Pavich, M. J.; Gellis, A. C.; Clark, I.; Ellwein, A. L.; Aby, S.

    2005-12-01

    A sediment budget was constructed for two subbasins of the Rio Puerco watershed, Volcano Hill Wash (9.30 km2) and Arroyo Chavez (2.28 km2), using data collected from 1995 through 1998. The subbasins were selected based on differences in land use. Arroyo Chavez was considered more degraded than Volcano Hill Wash, the latter of which received a grazing management award. The grazing density in the Arroyo Chavez watershed was higher (7.3 animals per 100 hectares) than in the Volcano Hill Wash watershed (1.0 animals per 100 hectares). A gas pipeline and numerous dirt roads are located within the Arroyo Chavez subbasin; neither are present within the Volcano Hill Wash subbasin. The 'old fashioned' sediment budget refers to the approach that was used--determining the total sediment leaving a basin and accounting for that sediment with a variety of field-based, labor intensive techniques. A sediment station with an automatic suspended-sediment sampler was installed at the mouth of each stream to quantify the amount of sediment leaving the subbasins. Upland erosion was measured using erosion pins and sediment traps. Channel erosion was measured using surveyed channel cross sections, bank pins, and scour chains. Aeolian dust deposition was measured with dust traps. Each subbasin was divided into geomorphic surfaces using aerial photographs and field descriptions of soils, slopes, and vegetation cover. In Volcano Hill Wash subbasin, five geomorphic surfaces were delineated: mesa, steep colluvial slopes, alluvium/ colluvium, eolian/alluvium, and the alluvial valley floor. In the Arroyo Chavez subbasin, seven geomorphic surfaces were delineated: mesa, steep colluvial slopes, moderate sloping hillslopes, gently sloping hillslopes, alluvial fans, well-vegetated alluvial valley floor, and a sparsely vegetated alluvial valley floor. Upland erosion and channel erosion rates were summed for each geomorphic surface using a geographical information system (GIS). Results indicate that

  6. Antibodies to Tacaribe Serocomplex Viruses (Family Arenaviridae, Genus Arenavirus) in Cricetid Rodents from New Mexico, Texas, and Mexico

    PubMed Central

    Milazzo, Mary L.; Barragán-Gomez, Artemio; Hanson, John Delton; Estrada-Franco, Jose G.; Arellano, Elizabeth; González-Cózatl, Francisco X.; Fernández-Salas, Ildefonso; Ramirez-Aguilar, Francisco; Rogers, Duke S.; Bradley, Robert D.

    2010-01-01

    Abstract Blood samples from 4893 cricetid rodents were tested for antibody (immunoglobulin G) to Whitewater Arroyo virus and Amaparí virus to extend our knowledge of the natural host range and geographical distribution of Tacaribe serocomplex viruses in North America. Antibodies to arenaviruses were found in northern pygmy mice (Baiomys taylori), woodrats (Neotoma spp.), northern grasshopper mice (Onychomys leucogaster), oryzomys (Oryzomys spp.), deermice (Megadontomys nelsoni and Peromyscus spp.), harvest mice (Reithrodontomys spp.), and cotton rats (Sigmodon spp.) captured in New Mexico, Texas, or Mexico. Comparison of endpoint antibody titers to Whitewater Arroyo virus and Amaparí virus in individual blood samples indicated that the Tacaribe complex viruses enzootic in Texas and Mexico are antigenically diverse. PMID:20795917

  7. Integrating multiple distribution models to guide conservation efforts of an endangered toad

    USGS Publications Warehouse

    Treglia, Michael L.; Fisher, Robert N.; Fitzgerald, Lee A.

    2015-01-01

    Species distribution models are used for numerous purposes such as predicting changes in species’ ranges and identifying biodiversity hotspots. Although implications of distribution models for conservation are often implicit, few studies use these tools explicitly to inform conservation efforts. Herein, we illustrate how multiple distribution models developed using distinct sets of environmental variables can be integrated to aid in identification sites for use in conservation. We focus on the endangered arroyo toad (Anaxyrus californicus), which relies on open, sandy streams and surrounding floodplains in southern California, USA, and northern Baja California, Mexico. Declines of the species are largely attributed to habitat degradation associated with vegetation encroachment, invasive predators, and altered hydrologic regimes. We had three main goals: 1) develop a model of potential habitat for arroyo toads, based on long-term environmental variables and all available locality data; 2) develop a model of the species’ current habitat by incorporating recent remotely-sensed variables and only using recent locality data; and 3) integrate results of both models to identify sites that may be employed in conservation efforts. We used a machine learning technique, Random Forests, to develop the models, focused on riparian zones in southern California. We identified 14.37% and 10.50% of our study area as potential and current habitat for the arroyo toad, respectively. Generally, inclusion of remotely-sensed variables reduced modeled suitability of sites, thus many areas modeled as potential habitat were not modeled as current habitat. We propose such sites could be made suitable for arroyo toads through active management, increasing current habitat by up to 67.02%. Our general approach can be employed to guide conservation efforts of virtually any species with sufficient data necessary to develop appropriate distribution models.

  8. Modern sediment yield compared to geologic rates of sediment production in a semi-arid basin, New Mexico: Assessing the human impact

    USGS Publications Warehouse

    Gellis, A.C.; Pavich, M.J.; Bierman, P.R.; Clapp, E.M.; Ellevein, A.; Aby, S.

    2004-01-01

    In the semi-arid Arroyo Chavez basin of New Mexico, a 2.28 km2 sub-basin of the Rio Puerco, we contrasted short-term rates (3 years) of sediment yield measured with sediment traps and dams with long-term, geologic rates (???10 000 years) of sediment production measured using 10Be. Examination of erosion rates at different time-scales provides the opportunity to contrast the human impact on erosion with background or geologic rates of sediment production. Arroyo Chavez is grazed and we were interested in whether differences in erosion rates observed at the two time-scales are due to grazing. The geologic rate of sediment production, 0-27 kg m-2 a -1 is similar to the modern sediment yields measured for geomorphic surfaces including colluvial slopes, gently sloping hillslopes, and the mesa top which ranged from 0.12 to 1.03 kg m -2 a-1. The differences between modern sediment yield and geologic rates of sediment production were most noticeable for the alluvial valley floor, which had modern sediment yields as high as 3.35 kg m-2 a-1. The hydraulic state of the arroyo determines whether the alluvial valley floor is aggrading or degrading. Arroyo Chavez is incised and the alluvial valley floor is gullied and piped and is a source of sediment. The alluvial valley floor is also the portion of the basin most modified by human disturbance including grazing and gas pipeline activity, both of which serve to increase erosion rates. ?? 2004 John Wiley and Sons, Ltd.

  9. 13. DETAIL VIEW OF BRIDGE, LOOKING SOUTH FROM ROADWAY. DETAIL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. DETAIL VIEW OF BRIDGE, LOOKING SOUTH FROM ROADWAY. DETAIL VIEW OF THE PIERS AND LIGHTING FIXTURES ON THE COLORADO STREET BRIDGE. THIS VIEW SHOWS A PORTION OF THE BRIDGE ALONG THE SOUTH SIDE OF THE ROADWAY. EACH FIXTURE ALSO ORIGINALLY HAD FOUR ADDITIONAL GLOBES, WHICH EXTENDED FROM THE COLUMN BELOW THE MAIN GLOBE. THE 'REFUGE' SEATING AREAS ARE ORIGINAL, WHILE THE RAILING IS A LATER ADDITION. - Colorado Street Bridge, Spanning Arroyo Seco at Colorado Boulevard, Pasadena, Los Angeles County, CA

  10. Unconventional petroleum resources in California

    SciTech Connect

    Hallmark, F.O.

    1980-09-01

    The distribution, physical characteristics, and potential of some of the more significant unconventional deposits in California are described in this report: diatomaceous oil shale in southern San Joaquin Valley and Casmalia area-Santa Barbara County; oil and tar sands in Oxnard oil field, Arroyo Grande, Santa Maria Valley, Sisquoc area, Salinas Valley, Richfield tar sand; and minor deposits in Santa Cruz County, Point Arena area-Mendocino County, and McKittrick tar sands. (DLC)

  11. Integrating Multiple Distribution Models to Guide Conservation Efforts of an Endangered Toad

    PubMed Central

    Treglia, Michael L.; Fisher, Robert N.; Fitzgerald, Lee A.

    2015-01-01

    Species distribution models are used for numerous purposes such as predicting changes in species’ ranges and identifying biodiversity hotspots. Although implications of distribution models for conservation are often implicit, few studies use these tools explicitly to inform conservation efforts. Herein, we illustrate how multiple distribution models developed using distinct sets of environmental variables can be integrated to aid in identification sites for use in conservation. We focus on the endangered arroyo toad (Anaxyrus californicus), which relies on open, sandy streams and surrounding floodplains in southern California, USA, and northern Baja California, Mexico. Declines of the species are largely attributed to habitat degradation associated with vegetation encroachment, invasive predators, and altered hydrologic regimes. We had three main goals: 1) develop a model of potential habitat for arroyo toads, based on long-term environmental variables and all available locality data; 2) develop a model of the species’ current habitat by incorporating recent remotely-sensed variables and only using recent locality data; and 3) integrate results of both models to identify sites that may be employed in conservation efforts. We used a machine learning technique, Random Forests, to develop the models, focused on riparian zones in southern California. We identified 14.37% and 10.50% of our study area as potential and current habitat for the arroyo toad, respectively. Generally, inclusion of remotely-sensed variables reduced modeled suitability of sites, thus many areas modeled as potential habitat were not modeled as current habitat. We propose such sites could be made suitable for arroyo toads through active management, increasing current habitat by up to 67.02%. Our general approach can be employed to guide conservation efforts of virtually any species with sufficient data necessary to develop appropriate distribution models. PMID:26125634

  12. Integrating Multiple Distribution Models to Guide Conservation Efforts of an Endangered Toad.

    PubMed

    Treglia, Michael L; Fisher, Robert N; Fitzgerald, Lee A

    2015-01-01

    Species distribution models are used for numerous purposes such as predicting changes in species' ranges and identifying biodiversity hotspots. Although implications of distribution models for conservation are often implicit, few studies use these tools explicitly to inform conservation efforts. Herein, we illustrate how multiple distribution models developed using distinct sets of environmental variables can be integrated to aid in identification sites for use in conservation. We focus on the endangered arroyo toad (Anaxyrus californicus), which relies on open, sandy streams and surrounding floodplains in southern California, USA, and northern Baja California, Mexico. Declines of the species are largely attributed to habitat degradation associated with vegetation encroachment, invasive predators, and altered hydrologic regimes. We had three main goals: 1) develop a model of potential habitat for arroyo toads, based on long-term environmental variables and all available locality data; 2) develop a model of the species' current habitat by incorporating recent remotely-sensed variables and only using recent locality data; and 3) integrate results of both models to identify sites that may be employed in conservation efforts. We used a machine learning technique, Random Forests, to develop the models, focused on riparian zones in southern California. We identified 14.37% and 10.50% of our study area as potential and current habitat for the arroyo toad, respectively. Generally, inclusion of remotely-sensed variables reduced modeled suitability of sites, thus many areas modeled as potential habitat were not modeled as current habitat. We propose such sites could be made suitable for arroyo toads through active management, increasing current habitat by up to 67.02%. Our general approach can be employed to guide conservation efforts of virtually any species with sufficient data necessary to develop appropriate distribution models. PMID:26125634

  13. Oligosarcus amome (Ostariophysi: Characidae), a new species from the río Uruguay basin, Misiones, Argentina.

    PubMed

    Almirón, Adriana; Casciotta, Jorge; Piálek, Lubomír; Doubnerová, Klára; Říčan, Oldřich

    2015-01-01

    Oligosarcus amome is described from tributaries of the arroyo Yabotí-Guazú, río Uruguay basin, Misiones Province, Argentina. This new species can be distinguished from all its congeners by the following combination of characters: presence of two conspicuous series of teeth on premaxilla bearing pentacuspidate teeth in the outer series. Oligosarcus amome is the sister taxon of all remaining analyzed species of the genus excepting O. itau.  PMID:25662145

  14. Status of the California Red-legged Frog (Rana draytonii) in the State of Baja California, México

    USGS Publications Warehouse

    Peralta-Garcia, Anny; Hellingsworth, Bradford D.; Richmond, Jonathan Q.; Valdez-Villavicencio, Jorge H.; Ruiz-Campos, Gorgonio; Fisher, Robert N.; Cruz-Hernandez, Pedro; Galina-Tessaro, Patricia

    2016-01-01

    The California Red-legged Frog (Rana draytonii) is a threatened species in the United States that has undergone population declines, especially in southern California. Due to the lack of information on the status of Mexican populations, we surveyed for the presence of R. draytonii in Baja California and assessed possible threats to population persistence. Our study area extended from the U.S.-Mexican border to the southern end of the distribution of the species in the Sierra San Pedro Mártir. We found R. draytonii at six of 15 historical sites, none at five proxy sites (i.e., alternative sites chosen because the historical record lacked precise locality data), and four at 24 additional sites. The 10 occupied sites are within three watersheds in the Sierra San Pedro Mártir (two sites at Arroyo San Rafael, two sites at Arroyo San Telmo, and six sites at Arroyo Santo Domingo). We did not detect R. draytonii at 60% of historical sites, including the highest elevation site at La Encantada and multiple low-elevation coastal drainages, suggesting the species has declined in Baja California. The threats we noted most frequently were presence of exotic aquatic animal species, water diversion, and cattle grazing. Management of remaining populations and local education is needed to prevent further declines.

  15. Channel evolution and hydrologic variations in the Colorado River basin: Factors influencing sediment and salt loads

    USGS Publications Warehouse

    Gellis, A.; Hereford, R.; Schumm, S.A.; Hayes, B.R.

    1991-01-01

    Suspended-sediment and dissolved-solid (salt) loads decreased after the early 1940s in the Colorado Plateau portion of the Colorado River basin, although discharge of major rivers - the Colorado, Green and San Juan - did not change significantly. This decline followed a period of high sediment yield caused by arroyo cutting. Reduced sediment loads have previously been explained by a change in sediment sampling procedures or changes in climate, land-use and conservation practices. More recent work has revealed that both decreased sediment production and sediment storage in channels of tributary basins produced the decline of sediment and salt loads. Sediment production and sediment storage are important components of incised-channel evolution, which involves sequential channel deepening, widening and finally floodplain formation. Accordingly, the widespread arroyo incision of the late nineteenth century resulted initially in high sediment loads. Since then, loads have decreased as incised channels (arroyos) have stabilized and begun to aggrade. However, during the 1940s, a period of low peak discharges permitted vegetational colonization of the valley floors, which further reduced sediment loads and promoted channel stabilization. This explanation is supported by experimental studies and field observations. Both geomorphic and hydrologic factors contributed to sediment storage and decreased sediment and salt loads in the upper Colorado River basin. ?? 1991.

  16. Application of ERTS-1 imagery to detecting and mapping modern erosion features, and to monitoring erosional changes, in southern Arizona

    NASA Technical Reports Server (NTRS)

    Morrison, R. B. (Principal Investigator); Cooley, M. E.

    1973-01-01

    The author has identified the following significant results. ERTS-1 multispectral images have been used, without additional data, to prepare three maps at 1:1 million scale of the 18,000 sq. mi. project area: (1) modern (post-1890 A. D.) arroyos and channels; (2) types of stream channels; and (3) potential erodibility of soils; surficial deposits, and bedrock. Also completed was the collection and compilation of ground truth geologic, soil, and hydrologic data. Field studies to obtain ground control for the photointerpretive mapping include: (1) measurements, at many sites, of the depth, width, and channel characteristics of arroyos and gullies, and cross profiles of stream channels, flood plains, and Holocene terraces; and (2) stratigraphic measurements of the Holocene alluvial deposits. Significant conclusions from these extensive stratigraphic studies are: Slow deposition of sediment was the dominant process on stream lowlands throughout the project area for at least 2000 years prior to 1890 A.D. The deposition was broken by only two relatively brief and minor erosional episodes of regional importance, when channels no more than a third of the depth of modern channels were cut. The modern erosion has produced within about 80 years substantially more and larger arroyos than any erosion episode during the last 2000 years, and the end is not in sight.

  17. Application of ERTS-1 imagery to detecting and mapping modern erosion features, and to monitoring erosional changes, in southern Arizona

    NASA Technical Reports Server (NTRS)

    Morrison, R. B.; Cooley, M. E.

    1973-01-01

    The author has identified the following significant results. The red MSS band 5 gives the sharpest definition of modern arroyos. On the best images, modern arroy0s can be distinguished as narrow as 150 to 200 feet in reaches where their contrast with adjacent areas is only moderate, and as narrow as 60 to 75 feet where their contrast is high. Both the red and infrared bands show differences is soils and vegetation. In the late fall and winter imagery, band 7 generally is the most useful for mapping the areas of the more erodible soils. A map at 1:1,000,000 scale has been prepared that shows all the arroyos within the 17,000 square mile study area that have been identified from ERTS-1 images. Also, from U-2 color infrared airphotos, a 1:125,000 scale map has been made of a 50 mile reach along San Simon Wash, in southeastern Arizona. This map shows not only the arroyo channels and narrow flood plains that have developed since 1890, but also areas within a few miles of the wash that are severely guilled, severely sheet-eroded, and moderately sheet-eroded. Two important effects of the third largest recorded flood of the upper Gila River also have been determined from the ERTS-1 images. The inundated area is best displayed on band 7, and the areas of severe sand/gravel erosion/deposition show best on band 5.

  18. Structural reinterpretation of the Ajo mining district, Pima County, Arizona, based on paleomagnetic and geochronologic studies.

    USGS Publications Warehouse

    Hagstrum, J.T.; Cox, D.P.; Miller, R.J.

    1987-01-01

    The Ajo mining district of southern Arizona is divided into two main structural blocks by the Gibson Arroyo fault. The eastern Camelback Mountain block contains the Late Cretaceous-early Tertiary porphyry copper deposit which has been previously thought to be associated with the displaced apex of a large intrusion exposed by deeper erosion in the western Cardigan Peak block. However, unpublished U-Pb data support a mid-Tertiary age for the western intrusion. The following sequence of mid-Tertiary events in the district are indicated: 1) emplacement of the western intrusion, 2) movement along the Gibson Arroyo fault, 3) unroofing and perhaps tilting of the pluton approx 70o to the south along with the Camelback Mountain block, 4) syntectonic depositions of the Locomotive Fanglomerate and the Ajo Volcanics, 5) continued uplift and tilting to the south totaling 40o to 60o, 6) intrusion of the youngest dikes with attendant alteration and remagnetization of the host rocks, and 7) minor (?) oblique movement along the Gibson Arroyo fault.-from Authors

  19. Effect of Conversion from Natural Grassland to Arable Land on Soil Carbon Reserve in the Argentinean Rolling Pampas

    NASA Astrophysics Data System (ADS)

    Andriulo, A. E.; Irizar, A. B.; Mary, B.; Wilson, M. G.

    2012-04-01

    The evaluation of the effect of land use change on accumulation of soil organic carbon (SOC) requires reliable data obtained from georeferenced sites with land use history records. The purpose of this study was to evaluate long term changes in the reserves of SOC in a typical Argiudol of the Pergamino series after the introduction of agriculture. Measures of soil organic carbon concentration and bulk density of Ap and A12 horizons were carried out in three sites of the Pergamino County (N of Buenos Aires province): a reference field with untilled pristine soil (33° 57' S; 60° 34' W), a field with 31 years (1980-2011) of agriculture (31Y) located next to the former, and a third field (33° 46' S; 60° 37' W) with 80 years (1910/1990) of agriculture (80Y). 31Y has been under continuous soybean cultivation with conventional tillage (CT) that consists of moldboard plow or double disk harrowing. At 80K the cultivation sequence was: 44 years of corn + 9 years of flax + 2 years of wheat + 17 years of wheat/soybean double cropping + 1 year of lentil; mostly under CT, some years under chisel plow during the 70's and a few years under zero tillage in soybean after wheat sown with conventional tillage during the 80's. Before the introduction of mechanical harvesting (1947) crop residues were burnt as well as the wheat stubble during the conventional double cropping period (1970-1980). Soil texture (23±1% clay, with predominance of illite) and field slopes (<0.5%) were similar in the three sites. Nitrogen and phosphorus fertilization rates were minimal due to the low crop response. The results are expressed in Mg ha-1 for an A soil horizon mass of 2500 Mg ha-1. The introduction of agriculture decreased SOC stock: 31Y varied from 68.3 to 40.1 Mg ha-1 (41.3% loss) and 80Y from 68.3 to 47.2 Mg ha-1 (30% loss). The SOC loss was the result of the mineralization of a large amount labile SOC present in the pristine soil and low annual additions of carbon issued from crop residue

  20. Characterization of selenium in the lower Gunnison River basin, Colorado, 1988-2000

    USGS Publications Warehouse

    Butler, David L.; Leib, Kenneth J.

    2002-01-01

    Selenium concentrations in certain water bodies in the lower Gunnison River Basin, including the lower Gunnison River and lower Uncompahgre River, have exceeded the Colorado water-quality standard of 5 micrograms per liter for selenium. A task force was formed in 1998 that consists of various government agencies, private irrigation companies, and local residents to address the selenium concerns in the lower Gunnison River Basin. The task force, working with the National Irrigation Water Quality Program, needed more detailed information on selenium loading in the basin to develop viable alternatives for remediating selenium in the lower Gunnison River Basin. In 1999-2000, the U.S. Geological Survey collected selenium data for tributaries of the Gunnison River downstream from the North Fork of the Gunnison and in the North Fork Basin. The largest selenium load in a tributary stream was in the Uncompahgre River, which accounted for about 38 percent of the selenium load in the Gunnison River at Whitewater. The North Fork of the Gunnison River accounted for about 7 percent of the selenium load in the Gunnison River. Two tributaries east of Delta, Sunflower Drain and Bonafide Ditch, consist primarily of irrigation return flows and were other major selenium sources to the Gunnison River. Some tributaries in the lower North Fork Basin had selenium concentrations exceeding 5 micrograms per liter. Except for several streams draining the Uncompahgre Plateau, many tributaries to the Gunnison River downstream from the North Fork had selenium concentrations exceeding 5 micrograms per liter. Except during occasional rain and snowmelt events, selenium loading from nonirrigated desert areas was minimal. Detailed characterization studies were done in 1999-2000 on Cedar Creek and Loutzenhizer Arroyo, which contribute the largest tributary selenium loads to the Uncompahgre River. Selenium concentrations in Cedar Creek downstream from Miguel Road ranged from 12 to 28 micrograms per

  1. A semiparametric multivariate and multisite weather generator

    NASA Astrophysics Data System (ADS)

    Apipattanavis, Somkiat; Podestá, Guillermo; Rajagopalan, Balaji; Katz, Richard W.

    2007-11-01

    We propose a semiparametric multivariate weather generator with greater ability to reproduce the historical statistics, especially the wet and dry spells. The proposed approach has two steps: (1) a Markov Chain for generating the precipitation state (i.e., no rain, rain, or heavy rain), and (2) a k-nearest neighbor (k-NN) bootstrap resampler for generating the multivariate weather variables. The Markov Chain captures the spell statistics while the k-NN bootstrap captures the distributional and lag-dependence statistics of the weather variables. Traditional k-NN generators tend to under-simulate the wet and dry spells that are keys to watershed and agricultural modeling for water planning and management; hence the motivation for this research. We demonstrate the utility of the proposed approach and its improvement over the traditional k-NN approach through an application to daily weather data from Pergamino in the Pampas region of Argentina. We show the applicability of the proposed framework in simulating weather scenarios conditional on the seasonal climate forecast and also at multiple sites in the Pampas region.

  2. Detection of different South American hantaviruses.

    PubMed

    Guterres, Alexandro; de Oliveira, Renata Carvalho; Fernandes, Jorlan; Schrago, Carlos Guerra; de Lemos, Elba Regina Sampaio

    2015-12-01

    Hantaviruses are the etiologic agents of Hemorrhagic Fever with Renal Syndrome (HFRS) in Old World, and Hantavirus Pulmonary Syndrome (HPS)/Hantavirus Cardiopulmonary Syndrome (HCPS), in the New World. Serological methods are the most common approach used for laboratory diagnosis of HCPS, however theses methods do not allow the characterization of viral genotypes. The polymerase chain reaction (PCR) has been extensively used for diagnosis of viral infections, including those caused by hantaviruses, enabling detection of few target sequence copies in the sample. However, most studies proposed methods of PCR with species-specific primers. This study developed a simple and reliable diagnostic system by RT-PCR for different hantavirus detection. Using new primers set, we evaluated human and rodent hantavirus positive samples of various regions from Brazil. Besides, we performed computational analyzes to evaluate the detection of other South American hantaviruses. The diagnostic system by PCR proved to be a sensible and simple assay, allowing amplification of Juquitiba virus, Araraquara virus, Laguna Negra virus, Rio Mamore virus and Jabora virus, beyond of the possibility of the detecting Andes, Anajatuba, Bermejo, Choclo, Cano Delgadito, Lechiguanas, Maciel, Oran, Pergamino and Rio Mearim viruses. The primers sets designed in this study can detect hantaviruses from almost all known genetics lineages in Brazil and from others South America countries and also increases the possibility to detect new hantaviruses. These primers could easily be used both in diagnosis of suspected hantavirus infections in humans and also in studies with animals reservoirs. PMID:26220480

  3. Phylogenetic and Geographical relationships of Hantavirus Strains in Eastern and Western Paraguay

    PubMed Central

    Chu, Yong-Kyu; Milligan, Brook; Owen, Robert D.; Goodin, Douglas G.; Jonsson, Colleen B.

    2009-01-01

    Recently, we reported the discovery of several potential rodent reservoirs of hantaviruses in western (Holochilus chacarius) and eastern Paraguay (Akodon montensis, Oligoryzomys chacoensis, and O. nigripes). Comparisons of the hantavirus S- and M-segments amplified from these four rodents revealed significant differences from each another and from other South American hantaviruses. The ALP strain from the semiarid Chaco ecoregion clustered with Leguna Negra and Rio Mamore (LN/RM), whereas the BMJ-ÑEB strain from the more humid lower Chaco ecoregion formed a clade with Oran and Bermejo. The other two strains, AAI and IP37/38, were distinct from known hantaviruses. With respect to the S-segment sequence, AAI from eastern Paraguay formed a clade with ALP/LN/RM, but its M-segment clustered with Pergamino and Maciel, suggesting a possible reassortment. AAI was found in areas experiencing rapid land cover fragmentation and change within the Interior Atlantic Forest. IP37/38 did not show any strong association with any of the known hantavirus strains. PMID:17172380

  4. Effects of Riparian Vegetation on Topographic Change During a Large Flood Event, Rio Puerco, New Mexico

    NASA Astrophysics Data System (ADS)

    Perignon, M. C.; Tucker, G. E.; Griffin, E. R.; Friedman, J. M.

    2012-12-01

    The nature and pattern of vegetation on floodplains strongly affect the morphological changes that result from large floods by increasing drag and steering the flow through the landscape. Quantifying those changes is only possible through the use of high-resolution, multi-temporal topographic datasets. In 2003, herbicides were sprayed on a section of the Rio Puerco, New Mexico, killing the tamarisk and sandbar willow on the floodplain and banks. A large flood in 2006 caused extensive erosion along the devegetated zone, widening the channel and eroding the floodplain. We use lidar differencing to quantify the topographic change that occurred along a 12-km reach of the arroyo immediately downstream of the sprayed section. We show that the pattern of deposition on the floodplain can be explained as the sum of two signals: the sediment concentration (which depends on the distance downstream of the sprayed reach), and local vegetation density. The presence of dense vegetation on the landscape, regardless of size or species, increases deposition by imparting a drag on the flow and reducing the boundary shear stress on the sediment surface. The spatial variability of sediment depth correlates with the size and spacing of stems: thick, widely spaced tamarisk trunks are associated with high variability in the depth of sedimentation, while dense but thin tamarisk and sandbar willow stems correlate with sheet-like deposits. Away from the influence of the sediment source, the erosion of the arroyo walls balances the deposition rate on the floodplain, resulting in widespread, uniform aggradation of the arroyo bottom.

  5. Application of ERTS-1 multispectral imagery to monitoring the present episode of accelerated erosion in southern Arizona

    NASA Technical Reports Server (NTRS)

    Morrison, R. B.; Cooley, M. E.

    1973-01-01

    An episode of accelerated arroyo-cutting and sheet erosion commenced about 1890 in southern Arizona, following several thousand years of generally sluggish erosion. For a 17,000-square-mile study area, ERTS-1 images, supplemented by ultrahigh-altitude (U-2 and RB-57) airphotos, are proving effective for producing the first comprehensive maps showing the distribution and seriousness of the post-1890 erosion features, for monitoring new erosion changes, and for assessing the effectiveness of ameliorative measures. Such data are essential for understanding and controlling the accelerated erosion, a key environmental problem in this region.

  6. KT boundary impact glasses from the Gulf of Mexico region

    NASA Technical Reports Server (NTRS)

    Claeys, Philippe; Alvarez, Walter; Smit, Jan; Hildebrand, A. R.; Montanari, Alessandro

    1993-01-01

    Cretaceous-Tertiary boundary (KTB) tektite glasses occur at several sites around the Gulf of Mexico. Contrary to rumor among KTB workers, glass fragments have been found by several researchers in the base of the spherule bed at Arroyo el Mimbral in NE Mexico. The presence of green, red, and transparent glass fragments at Mimbral only, demonstrates that the Mimbral glass is not a laboratory contamination by Beloc glass. The chemistry and ages of the glass are consistent with an origin from the Chixculub impact crater in Yucatan. No evidence supports a volcanic origin for the KTB glasses. A discussion of tektite glass from the KT boundary is presented.

  7. Response to Esteve-Gassent et al.: flaB sequences obtained from Texas PCR products are identical to the positive control strain Borrelia burgdorferi B31.

    PubMed

    Norris, Steven J; Barbour, Alan G; Fish, Durland; Diuk-Wasser, Maria A

    2015-01-01

    Feria-Arroyo et al. had reported previously that, based on PCR analysis, 45% of Ixodes scapularis ticks collected in Texas and Mexico were infected with the Lyme disease spirochete Borrelia burgdorferi (Parasit. Vectors 2014, 7:199). However, our analyses of their initial data (Parasit. Vectors 2014, 7:467) and a recent response by Esteve-Gassent et al. (Parasit. Vectors 2015, 8:129) provide evidence that the positive PCR results obtained from both ribosomal RNA intergenic sequences and the flagellin gene flaB are highly likely due to contamination by the B. burgdorferi B31 positive control strain. PMID:26050617

  8. Characterization of nickel and vanadium compounds in tar sand bitumen by petroporphyrin quantitation and size exclusion chromatography coupled with element specific detection

    SciTech Connect

    Reynolds, J.G.; Jones, E.L.; Bennett, J.A.; Biggs, W.R.

    1988-02-01

    Previously, we have examined the Ni and V in heavy crude oils, residua, and processed products by several metal speciation techniques to ascertain molecular structure and processing behavior. Two classes of metal compounds were found/--/metallopetroporphyrins and metallo-nonporphyrins/--/each having unique reactivity during processing. In efforts to better understand the binding of metals in the oil medium, we have now examined Ni and V in tar sand bitumens. The bitumen was solvent extracted from the sand matrix and was separated by column chromatography to quantitate petroporphyrin content. The petroporphyrin contents ranged from virtually none to over 36% of the total metals. Asphalt Ridge (Utah) has primarily Ni petroporphyrins; Big Clifty (Kentucky) and Athabasca (Canada) have primarily V petroporphyrins; Arroyo Grande and McKittrick (California) have roughly equal amounts of both types; and Sunnyside (Utah) has virtually none of either. Size characteristic profiles (SEC-HPLC-ICP) were generated for the extracted bitumens. The profiles are generally bimodal in shape and resemble several different specific heavy crude oils and residua. For examples, Arroyo Grande and McKittrick appear to be similar to Kern River (California) 650/degree/F+ residuum, while Athabasca resembles Morichal (Venezuela) 650/degree/F+ residuum. These results will be discussed in terms of generalized profile and petroporphyrin behavior. 23 refs., 3 figs., 3 tabs.

  9. Elevated DDE and toxaphene residues in fishes and birds reflect local contamination in the lower Rio Grande Valley, Texas

    USGS Publications Warehouse

    White, D.H.; Mitchell, C.A.; Kennedy, H.D.; Krynitsky, A.J.; Ribick, M.A.

    1983-01-01

    A potential organochlorine pesticide problem was identified near Mission, Texas, by the National Pesticide Monitoring Program. Fish samples from this site have consistently contained elevated levels of DDE since 1968. Surveys were made in 1976, 1978, and 1979 to determine the extent of organochlorine pesticide contamination in fishes and birds of the area. Freshwater fishes of the Arroyo Colorado, a major waterway traversing the lower Rio Grande Valley, were highly contaminated with DDE and toxaphene residues compared to samples from other areas in the Valley; both DDE and toxaphene ranged up to 31.5 ppm wet weight in whole-fish composite samples. In addition, median DDE residues in fish-eating bird carcasses from this area ranged up to 34 ppm wet weight, and 81 ppm in individual specimens. The levels of contaminants detected in fishes and birds were within, or above, the range producing adverse effects in certain species. The major sources of contamination to the Arroyo Colorado system likely stem from past and present use of persistent pesticides on surrounding croplands, and possibly from an abandoned pesticide plant at Mission, Texas.

  10. Assessment of gully-control structures in the Rio Nutria watershed, Zuni reservation, New Mexico

    USGS Publications Warehouse

    Gellis, Allen C.; Cheama, Andres; Laahty, Vanissa; Lalio, Sheldon

    1995-01-01

    During the latter part of the 19th century and the early part of the 20th century, a major cycle of erosion, arroyo cutting, and gullying occurred in the southwestern United States. Since this erosion cycle began, many projects to control erosion, such as the Civilian Conservation Corps projects in the 1930s, were initiated. However, in the Southwestern United States few studies have documented the effect of these structures in reducing erosion or their effect on gully systems. As part of a watershed rehabilitation project on the Zuni Reservation, New Mexico, 47 structures made either of earth or rocks and 23 rock and brush structures were assessed. Sixty percent of the 47 earth or rock structures have breached and relative to dam height, 65 percent of 47 structures are more than 50 percent silted. Of the 23 rock and brush structures, 22 percent have breached or are close to breaching. Reasons for breaching of all structural types may be piping, scour immediately below the structures, large runoff and large drainage area, poor maintenance, headcutting, and active arroyo deepening and widening. In most cases, documentation does not exist on structure design, the specific purpose for a structure, or when these structures were built.

  11. Ediacaran in Uruguay: Facts and controversies

    NASA Astrophysics Data System (ADS)

    Aubet, Natalie R.; Pecoits, Ernesto; Heaman, Larry M.; Veroslavsky, Gerardo; Gingras, Murray K.; Konhauser, Kurt O.

    2014-11-01

    The Ediacaran of Uruguay has been regarded as containing a significant geological and paleontological record, which would make these successions critical to unraveling diverse aspects regarding the assembly of southwestern Gondwana and to understanding the conditions surrounding the rise of animal life in a period punctuated by drastic paleoenvironmental changes. However, a review of currently available data leads to the conclusion that, although variable, the stratigraphy, distribution and age of these units remain ambiguous. The same is true for existing basin models and tectonic evolution, which show different and sometimes contradicting supporting evidence. Here, we propose that the Ediacaran record consists of the Maldonado Group (Playa Hermosa, Las Ventanas and San Carlos formations), and the Tacuarí, Barriga Negra, Rocha and Sierra de Aguirre formations. The Arroyo del Soldado Group (Yerbal, Polanco Limestones and Cerro Espuelitas formations) and the Arroyo de la Pedrera Group (Piedras de Afilar and Cerro Victoria formations) were likely deposited between 700 and 1000 Ma. The best available radiometric age constraints indicate intense magmatic-tectonic activity occurred between 600 and 560 Ma, incompatible with previous models suggesting a stable, Atlantic-type passive margin on this portion of southwestern Gondwana. Further research is needed in order to firmly establish a consistent litho- and chronostratigraphic framework; particularly, before attempting any regional or global correlation, and inferences on global paleoenvironmental and paleobiological events.

  12. Fish faunas from the Late Jurassic (Tithonian) Vaca Muerta Formation of Argentina: One of the most important Jurassic marine ichthyofaunas of Gondwana

    NASA Astrophysics Data System (ADS)

    Gouiric-Cavalli, Soledad; Cione, Alberto Luis

    2015-11-01

    The marine deposits of the Vaca Muerta Formation (Tithonian-Berriasian) houses one of the most diverse Late Jurassic ichthyofaunas of Gondwana. However, most of the specimens remain undescribed. Jurassic fishes have been recovered from several localities at Neuquén Province (i.e., Picún Leufú, Plaza Huincul, Cerro Lotena, Portada Las Lajas, Los Catutos, and Arroyo Covunco) but also from Mendoza Province (i.e., La Valenciana, Los Molles, and Arroyo del Cajón Grande). Presently, the fish fauna of Los Catutos, near Zapala city (Neuquén Province), has yielded the highest number of specimens, which are taxonomically and morphologically diverse. At Los Catutos locality, the Vaca Muerta Formation is represented by the Los Catutos Member, which is considered the only lithographic limestones known in the Southern Hemisphere. Here, we review the Tithonian fish faunas from the Vaca Muerta Formation. During Late Jurassic times, the actual Argentinian territory could have been a morphological diversification center, at least for some actinopterygian groups. The apparently lower species diversity recorded in marine Jurassic ichthyofaunas of Argentina (and some Gondwanan countries) in comparison with Chilean and European fish faunas could be related to the fish paleontological research history in Gondwana and the low number of detailed studies of most of specimens recorded.

  13. Elevated DDE and toxaphene residues in fishes and birds reflect local contamination in the lower Rio Grande valley Texas USA

    USGS Publications Warehouse

    White, D.H.; Mitchell, C.A.; Kennedy, H.R.; Krynitsky, A.J.; Ribick, M.A.

    1983-01-01

    A potential organochlorine pesticide problem was identified near Mission, Texas, by the National Park Monitoring Program. Fish samples from this site have consistently contained elevated levels of DDE since 1968. Surveys were made in 1976, 1978, and 1979 to determine the extent of organochlorine pesticide contamination in fishes and birds of the area. Freshwater fishes of Arroyo Colorado, a major waterway traversing the lower Rio Grande Valley, were highly contaminated with DDE and toxaphene residues compared to samples from other areas in the Valley; both DDE and toxaphene ranged up to 31.5 ppm wet wt in whole-fish composite samples. Median DDE residues in fish-eating bird carcasses from this area ranged up to 34 ppm wet wt, and 81 ppm in individual specimens. The levels of contaminants detected in fishes and birds were within, or above, the range producing adverse effects in certain species. The major sources of contamination to the Arroyo Colorado system likely stem from past and present use of persistent pesticides on surrounding croplands, and possibly from an abandoned pesticide plant at Mission, Texas.

  14. Population Dynamics of an Insect Herbivore over 32 Years are Driven by Precipitation and Host-Plant Effects: Testing Model Predictions.

    PubMed

    Price, Peter W; Hunter, Mark D

    2015-06-01

    The interaction between the arroyo willow, Salix lasiolepis Bentham, and its specialist herbivore, the arroyo willow stem-galling sawfly, Euura lasiolepis Smith (Hymenoptera: Tenthredinidae), was studied for 32 yr in Flagstaff, AZ, emphasizing a mechanistic understanding of insect population dynamics. Long-term weather records were evaluated to provide a climatic context for this study. Previously, predictive models of sawfly dynamics were developed from estimates of sawfly gall density made between 1981 and 2002; one model each for drier and wetter sites. Predictor variables in these models included winter precipitation and the Palmer Drought Severity Index, which impact the willow growth, with strong bottom-up effects on sawflies. We now evaluate original model predictions of sawfly population dynamics using new data (from 2003-2012). Additionally, willow resources were evaluated in 1986 and in 2012, using as criteria clone area, shoot density, and shoot length. The dry site model accounted for 40% of gall population density variation between 2003 and 2012 (69% over the 32 yr), providing strong support for the bottom-up, mechanistic hypothesis that water supply to willow hosts impacts sawfly populations. The current drying trend stressed willow clones: in drier sites, willow resources declined and gall density decreased by 98%. The wet site model accounted for 23% of variation in gall population density between 2003 and 2012 (48% over 30 yr), consistent with less water limitation. Nonetheless, gall populations were reduced by 72%. PMID:26313951

  15. Channel-changing processes on the Santa Cruz River, Pima County, Arizona, 1936-86

    USGS Publications Warehouse

    Parker, John T.C.

    1990-01-01

    Lateral channel change on the mainly ephemeral Santa Cruz River, Pima County, Arizona, causes damage and has spawned costly efforts to control bank erosion. Aerial photographs, historical data, and field observations are used to document the history of channel change since 1936. Variability in the nature and degree of channel change over time and space is shown. Three major channel change processes are: (1) migration by bank erosion during meander migration or initiation; (2) avulsion by overbank flooding and flood plain incision; (3) widening by erosion of low, cohesionless banks during floods and arroyo widening by undercutting and mass wasting of deeply incised vertical walls. The first process generally is a product of low to moderate flows or waning high flows; the others result mainly from higher flows, though sensitive arroyo walls may erode during relatively low flows. Channel morphology, bank resistance, and hydrology are factors determining the dominant channel-changing process on a particular reach of the river. Present river morphology reflects high flows since the 1960's.

  16. Fluvial system response to late Pleistocene-Holocene sea-level change on Santa Rosa Island, Channel Islands National Park, California

    NASA Astrophysics Data System (ADS)

    Schumann, R. Randall; Pigati, Jeffrey S.; McGeehin, John P.

    2016-09-01

    Santa Rosa Island (SRI) is one of four east-west aligned islands forming the northern Channel Islands chain, and one of the five islands in Channel Islands National Park, California, USA. The island setting provides an unparalleled environment in which to record the response of fluvial systems to major changes of sea level. Many of the larger streams on the island occupy broad valleys that have been filled with alluvium and later incised to form steep- to vertical-walled arroyos, leaving a relict floodplain as much as 12-14 m above the present channel. The period of falling sea level between the end of the last interglacial highstand at ~ 80 ka and the last glacial lowstand at ~ 21 ka was marked by erosion and incision in the uplands and by deposition of alluvial sediment on the exposed marine shelf. Sea level rose relatively rapidly following the last glacial lowstand of - 106 m, triggering a shift from an erosional to a depositional sedimentary regime. Accumulation of sediment occurred first through vertical and lateral accretion in broad, shallow channels on the shelf. Channel avulsion and delta sedimentation produced widespread deposition, creating lobes or wedges of sediment distributed across relatively large areas of the shelf during the latest Pleistocene. Backfilling of valleys onshore (landward of present sea level) appears to have progressed in a more orderly and predictable fashion throughout the Holocene primarily because the streams were confined to their valleys. Vertical aggradation locally reduced stream gradients, causing frequent overbank flooding and lateral channel shift by meandering and/or avulsion. Local channel gradient and morphology, short-term climate variations, and intrinsic controls also affected the timing and magnitudes of these cut, fill, and flood events, and are reflected in the thickness and spacing of the episodic alluvial sequences. Floodplain aggradation within the valleys continued until at least 500 years ago, followed by

  17. A field guide for the assessment of erosion, sediment transport, and deposition in incised channels of the southwestern United States

    USGS Publications Warehouse

    Parker, John T.C.

    2000-01-01

    Deeply incised channels, commonly called arroyos, are a typical feature of the dry alluvium-filled valleys of the southwestern United States. Unlike many geological processes that operate over millions of years, the formation of many miles of arroyos is one that took place in a little more than a century. Most arroyos in the region began to form in the late 19th century. Because dry landscapes change so quickly, they present society with special problems. Rapid expansion of channels by headcut migration, deepening, and widening causes loss of productive agricultural and commercial lands and threatens infrastructure such as roads, bridges, and buildings. High rates of sedimentation shorten the life of reservoirs, clog culverts, and fill stream channels to the extent that they can no longer contain streamflow within their banks. This report presents an explanation of erosional and depositional processes in desert landscapes, especially those characterized by incised channels, for the use of those who use, manage, and live on such lands. The basic principles of erosion, sediment transport, and deposition are presented including the formation of sediment, the forces that erode and transport it, the forces that resist its erosion and transport, and the conditions that cause it to be deposited. The peculiarities of sedimentation processes in the Southwest include the infrequent and variable precipitation, the geological setting, and the sparseness of vegetation. A classification system for incised channels that is intended for users who do not necessarily have a background in fluvial hydrology has been developed and is presented in this report. The classification system is intended to enable a user to classify a reach of channel quickly on the basis of field observations. The system is based on the shape and condition of channels and on the sedimentation processes that are predominantly responsible for those conditions. Because those processes are controlled by

  18. Fluvial system response to late Pleistocene-Holocene sea-level change on Santa Rosa Island, Channel Islands National Park, California

    USGS Publications Warehouse

    Schumann, R. Randall; Pigati, Jeffery S.; McGeehin, John P.

    2016-01-01

    Santa Rosa Island (SRI) is one of four east-west aligned islands forming the northern Channel Islands chain, and one of the five islands in Channel Islands National Park, California, USA. The island setting provides an unparalleled environment in which to record the response of fluvial systems to major changes of sea level. Many of the larger streams on the island occupy broad valleys that have been filled with alluvium and later incised to form steep- to vertical-walled arroyos, leaving a relict floodplain as much as 12–14 m above the present channel. The period of falling sea level between the end of the last interglacial highstand at ~ 80 ka and the last glacial lowstand at ~ 21 ka was marked by erosion and incision in the uplands and by deposition of alluvial sediment on the exposed marine shelf. Sea level rose relatively rapidly following the last glacial lowstand of − 106 m, triggering a shift from an erosional to a depositional sedimentary regime. Accumulation of sediment occurred first through vertical and lateral accretion in broad, shallow channels on the shelf. Channel avulsion and delta sedimentation produced widespread deposition, creating lobes or wedges of sediment distributed across relatively large areas of the shelf during the latest Pleistocene. Backfilling of valleys onshore (landward of present sea level) appears to have progressed in a more orderly and predictable fashion throughout the Holocene primarily because the streams were confined to their valleys. Vertical aggradation locally reduced stream gradients, causing frequent overbank flooding and lateral channel shift by meandering and/or avulsion. Local channel gradient and morphology, short-term climate variations, and intrinsic controls also affected the timing and magnitudes of these cut, fill, and flood events, and are reflected in the thickness and spacing of the episodic alluvial sequences. Floodplain aggradation within the valleys continued until at least 500 years ago

  19. Livermore Big Trees Park Soil Survey

    SciTech Connect

    McConachie, W.A.; Failor, R.A.

    1995-01-01

    Lawrence Livermore National Laboratory (LLNL) will sample and analyze soil in the Big Trees Park area in Livermore, California, to determine if the initial level of plutonium (Pu) in a soil sample taken by the U.S. Environmental Protection Agency (EPA) in September 1993 can be confirmed. Nineteen samples will be collected and analyzed: 4 in the area where the initial EPA sample was taken, 2 in the nearby Arroyo Seco, 12 in scattered uncovered soil areas in the park and nearby school, and 1 from the sandbox of a nearby apartment complex. Two quality control (QC) samples (field duplicates of the preceding samples) win also be collected and analyzed. This document briefly describes the purpose behind the sampling, the sampling rationale, and the methodology.

  20. Field based analysis of sediment entrainment in two high gradient streams located in Alpine and Andine environments

    NASA Astrophysics Data System (ADS)

    Mao, Luca; Uyttendaele, Geertrui Paula; Iroumé, Andrés; Lenzi, Mario Aristide

    2008-01-01

    This paper presents an analysis of critical thresholds for bedload transport based on field measurements conducted in two small, high gradient streams: the Rio Cordon (Italian Alps) and the Tres Arroyos (Chilean Andes). The threshold of incipient motion was identified by using marked particles displacement and both flood and flow competence approaches. The findings are expressed in terms of Shields parameter, dimensionless discharge, and specific stream power, and are used to identify the effects of relative grain size, relative depth, and bedform resistance. Overall, particle entrainment tends to be size selective, rather than exhibiting equal mobility, and the high values of dimensionless critical shear stress observed at both study sites confirm the additional roughness effects of step-pool morphologies that are very effective in reducing the bed shear stress and causing an apparent increase in critical shear stress.

  1. Preliminary Geophysical Characterization of a CO2-Driven Geyser in the Rio Grande Rift, New Mexico

    NASA Astrophysics Data System (ADS)

    Feucht, D. W.; Jensen, K. J.; Kelly, C.; Ryan, J. C.; Ferriz, H.; Kanjorski, N.; Ferguson, J. F.; McPhee, D. K.; Pellerin, L.

    2009-12-01

    As part of the Summer of Applied Geophysical Experience (SAGE) a preliminary geophysical investigation was conducted in the vicinity of a cold CO2-driven geyser located at Chimayó, NM, along the eastern margin of the Rio Grand Rift. This geyser is of interest as a possible analog for CO2 leakage from deep saline-aquifer carbon sequestration projects. Observed water chemistry variations can be explained by mixing of a CO2-rich, high salinity brine rising into, and mixing with a shallow freshwater aquifer. Several large, basin bounding faults and numerous smaller normal faults cut the area of the well and may constitute the necessary conduit for the deep water. Geophysical methods were used to characterize the subsurface properties at the Chimayó geyser as well as regional structures that may influence groundwater flow in the area. Shallow transient electromagnetic (TEM) data and capactively-coupled resistivity (CCR) data were acquired in close proximity to the geyser. The CCR shows a near-surface resistive feature, possibly hematite-cemented Tesuque formation sediment, in close proximity to the geyser. A shallow, highly conductive layer delineated through modeling of the TEM data is postulated to be a fluid consistent with high levels of Total Dissolved Solid (TDS) content. The well is located almost directly on the Roberts fault, which is antithetic to the basin bounding Chimayó fault 1.5 km to the east. Previously published hydrogeochemical studies associate this fault with high CO2 and TDS water along its strike. Deeper sounding TEM and audiomagnetotelluric (AMT) data were acquired along the Alamo Arroyo, 3 km to the southwest of the well. The Kelley Federal #1 Well located in this arroyo provides deep stratigraphic control to Pennsylvanian carbonate basement at 740 m. Tesuque formation conglomeritic alluvial fan deposits occur between 230 and 708 m and are overlain by finer grained basin floor deposits. The deep, coarse grained unit is thought to be a good

  2. A California Multidisciplinary Juvenile Court: Serving Sexually Exploited and At-Risk Youth.

    PubMed

    Liles, Brandi D; Blacker, Dawn M; Landini, Jenny L; Urquiza, Anthony J

    2016-01-01

    Research suggests that 90% of youth in the juvenile justice system have experienced at least one traumatic event (Arroyo, ). One such traumatic event is the commercialized sexual exploitation of children and youth (CSEC). Over the past decade, governmental organizations and community agencies have recognized that the sexual exploitation of children is a significant problem in the United States. In California alone, human trafficking task forces have identified 1200 youth as victims of sexual exploitation from 2010 to 2012 (Walker, ). Youth who have experienced sexual exploitation often become involved in the juvenile justice system and present with unique challenges and needs. This article reviews recent public policy and community responses related to the needs of CSEC youth involved in the juvenile justice system. A case example from Sacramento, CA, is used to illustrate the key components, innovations, multidisciplinary collaborations, and challenges of creating a specialized court. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27117605

  3. Three new species and one new record of Campylaimus (Diplopeltidae, Nematoda) from Argentine coasts (Buenos Aires and Santa Cruz, Argentina).

    PubMed

    Villares, Gabriela; Martelli, Antonela; Russo, Virginia Lo; Pastor, Catalina

    2013-01-01

    Two new Campylaimus species from Arroyo Pareja, Buenos Aires province and one new species and one new record of Campylaimus from Puerto San Julián, Chubut province are described. The three species are characterized by the shape of the copulatory apparatus of the male and the presence of precloacal papillae. Campylaimus bonariensis sp. nov. has slender and arcuate spicules, with well-developed cephalization at the proximal end, tubular gubernaculum and three precloacal papillae; Campylaimus arcuatus sp. nov. has curved spicules, with well-developed cephalization at the proximal end, gubernaculum with dorso-caudally directed apophysis and five precloacal papillae; Campylaimus patagonicus sp. nov. has slender and arcuate spicules without proximal cephalization, gubernaculum with dorso-caudally directed apophysis and two precloacal papillae. An emended diagnosis of the genus Campylaimus and an identification key to species based on male characters are given. PMID:24698903

  4. The California Storm of January 1862

    NASA Astrophysics Data System (ADS)

    Engstrom, Wayne N.

    1996-09-01

    The greatest storm in the written history of California struck the region in the winter of 1861-1862. The unusual weather began on Christmas Eve, 1861, and persisted for some 45 days as a series of middle-latitude cyclones made landfall along the California coast. Episodes of very cold and very warm temperatures occurred both during the storm and in the spring of 1862 as meridional flow prevailed. Heavy precipitation swelled the Santa Ana River to more than triple the highest estimated discharge in this century. High water levels in coastal streams between Los Angeles and San Diego persisted into the spring. Lakes were created in the Los Angeles Basin and the Mojave Desert. Arroyos were cut. Sediments from the flood may be preserved in offshore basins.

  5. Multivariate Statistical Analysis of Water Chemistry in Evaluating the Origin of Contamination in Many Devils Wash, Shiprock, New Mexico

    SciTech Connect

    None, None

    2012-12-31

    This report evaluates the chemistry of seep water occurring in three desert drainages near Shiprock, New Mexico: Many Devils Wash, Salt Creek Wash, and Eagle Nest Arroyo. Through the use of geochemical plotting tools and multivariate statistical analysis techniques, analytical results of samples collected from the three drainages are compared with the groundwater chemistry at a former uranium mill in the Shiprock area (the Shiprock site), managed by the U.S. Department of Energy Office of Legacy Management. The objective of this study was to determine, based on the water chemistry of the samples, if statistically significant patterns or groupings are apparent between the sample populations and, if so, whether there are any reasonable explanations for those groupings.

  6. Transmission of an arenavirus in white-throated woodrats (Neotoma albigula), southeastern Colorado, 1995-1999.

    PubMed Central

    Calisher, C. H.; Nabity, S.; Root, J. J.; Fulhorst, C. F.; Beaty, B. J.

    2001-01-01

    From 1995 to 1999, we conducted longitudinal studies of white- throated woodrats (Neotoma albigula) in southeastern Colorado. Forty-five (42.9%) of 105 female and 15 (26.8%) of 56 male N. albigula had antibodies against Whitewater Arroyo virus (WWAV). Sixteen female and three male N. albigula seroconverted during the study period, most of them during July-November, when population densities are highest. Analyses of longevity data, minimum numbers alive and infected, movements, and weight data suggest that the dominant mode of WWAV transmission among white-throated woodrats in Colorado is direct contact. WWAV was recently reported to cause fatal infection in humans. Our findings will lead to better assessment of the public health threat posed by infected woodrats and may be useful in predicting periods of increased risk for human infection. PMID:11384515

  7. Survey of subsurface treatment technologies for environmental restoration sites at Sandia National Laboratories, New Mexico.

    SciTech Connect

    McGrath, Lucas K.; Ho, Clifford Kuofei; Wright, Jerome L.

    2003-08-01

    This report provides a survey of remediation and treatment technologies for contaminants of concern at environmental restoration (ER) sites at Sandia National Laboratories, New Mexico. The sites that were evaluated include the Tijeras Arroyo Groundwater, Technical Area V, and Canyons sites. The primary contaminants of concern at these sites include trichloroethylene (TCE), tetrachloroethylene (PCE), and nitrate in groundwater. Due to the low contaminant concentrations (close to regulatory limits) and significant depths to groundwater ({approx}500 feet) at these sites, few in-situ remediation technologies are applicable. The most applicable treatment technologies include monitored natural attenuation and enhanced bioremediation/denitrification to reduce the concentrations of TCE, PCE, and nitrate in the groundwater. Stripping technologies to remove chlorinated solvents and other volatile organic compounds from the vadose zone can also be implemented, if needed.

  8. Revisions to the stratigraphic nomenclature of the Abiquiu Formation, Abiquiu and contiguous areas, north-central New Mexico

    USGS Publications Warehouse

    Maldonado, Florian; Kelley, Shari A.

    2009-01-01

    Stratigraphic studies and geologic mapping on the Abiquiu 7.5-min quadrangle have led to revision of the stratigraphic nomenclature for the Oligocene to Miocene Abiquiu Formation in north-central New Mexico. The Abiquiu Formation had previously been defined to include informal upper, middle (Pedernal chert member), and lower members. The basement-derived conglomeratic lower member in the northern Jemez Mountains and Abiquiu embayment is here redefined. We propose removing the "lower member" from the Abiquiu Formation because provenance of these coarse sediments is dramatically different than the volcaniclastic strata of the "upper member." Furthermore, we propose that the term "lower member of the Abiquiu Formation" be replaced with an existing unit name, the Ritito Conglomerate of Barker (1958), and that the name Abiquiu Formation be restricted to the volcaniclastic succession. The lower part of the Ritito Conglomerate in Arroyo del Cobre on the Abiquiu quadrangle is 47 m (155 ft) thick and is composed of arkosic conglomeratic beds interbedded with arkosic sands and siltstones. Clasts include, in descending order of abundance, Proterozoic quartzite, granite, metavolcanic rocks, quartz, schist, and gneiss and a trace of Mesozoic sandstone and Paleozoic chert. Clasts are predominantly of pebble and cobble size but range from granule to boulder size. Paleocurrent data collected in the Arroyo del Cobre area indicate that the Ritito Conglomerate was deposited by a south-flowing river system during the Oligocene, eroding Laramide highlands such as the Tusas Mountains to the northeast, which contain predominantly Proterozoic rocks. This depositional setting has also been suggested by previous workers. The middle member or Pedernal chert member is present both at the top of the Ritito Conglomerate and as lenses within the lower part of the Abiquiu Formation. This post-depositional diagenetic chert remains an informal unit called the Pedernal chert.

  9. Dating floodplain sediments using tree-ring response to burial

    USGS Publications Warehouse

    Friedman, J.M.; Vincent, K.R.; Shafroth, P.B.

    2005-01-01

    Floodplain sediments can be dated precisely based on the change in anatomy of tree rings upon burial. When a stem of tamarisk (Tamarix ramosissima) or sandbar willow (Salix exigua) is buried, subsequent annual rings in the buried section resemble the rings of roots: rings become narrower, vessels within the rings become larger, and transitions between rings become less distinct. We combined observations of these changes with tree-ring counts to determine the year of deposition of sedimentary beds exposed in a 150-m-long trench across the floodplain of the Rio Puerco, a rapidly filling arroyo in New Mexico. This method reliably dated most beds thicker than about 30 cm to within a year of deposition. Floodplain aggradation rates varied dramatically through time and space. Sediment deposition was mostly limited to brief overbank flows occurring every few years. The most rapid deposition occurred on channel-margin levees, which migrated laterally during channel narrowing. At the decadal timescale, the cross-section-average sediment deposition rate was steady, but there was a shift in the spatial pattern of deposition in the 1980s. From 1936 to 1986, sediment deposition occurred by channel narrowing, with little change in elevation of the thalweg. After 1986 sediment deposition occurred by vertical aggradation. From 1936 to 2000 about 27 per cent of the arroyo cross-section filled with sediment. The rate of filling from 1962 to 2000 was 0-8 vertical m/decade or 85 m2/decade. Published in 2005 by John Wiley & Sons, Ltd.

  10. Valley-fill alluviation during the Little Ice Age (ca. A.D. 1400-1880), Paria River basin and southern Colorado Plateau, United States

    USGS Publications Warehouse

    Hereford, R.

    2002-01-01

    Valley-fill alluvium deposited from ca. A.D. 1400 to 1880 is widespread in tributaries of the Paria River and is largely coincident with the Little Ice Age epoch of global climate variability. Previous work showed that alluvium of this age is a mappable stratigraphic unit in many of the larger alluvial valleys of the southern Colorado Plateau. The alluvium is bounded by two disconformities resulting from prehistoric and historic arroyo cutting at ca. A.D. 1200-1400 and 1860-1910, respectively. The fill forms a terrace in the axial valleys of major through-flowing streams. This terrace and underlying deposits are continuous and interfinger with sediment in numerous small tributary valleys that head at the base of hillslopes of sparsely vegetated, weakly consolidated bedrock, suggesting that eroded bedrock was an important source of alluvium along with in-channel and other sources. Paleoclimatic and high-resolution paleoflood studies indicate that valley-fill alluviation occured during a long-term decrease in the frequency of large, destructive floods. Aggradation of the valleys ended about A.D. 1880, if not two decades earlier, with the beginning of historic arroyo cutting. This shift from deposition to valley entrenchment near the close of the Little Ice Age generally coincided with the beginning of an episode of the largest floods in the preceding 400-500 yr, which was probably caused by an increased recurrence and intensity of flood-producing El Nin??o events beginning at ca. A.D. 1870.

  11. Conversion to drip irrigated agriculture may offset historic anthropogenic and wildfire contributions to sediment production.

    PubMed

    Gray, A B; Pasternack, G B; Watson, E B; Goñi, M A; Hatten, J A; Warrick, J A

    2016-06-15

    This study is an investigation into the roles of wildfire and changing agricultural practices in controlling the inter-decadal scale trends of suspended sediment production from semi-arid mountainous rivers. In the test case, a decreasing trend in suspended sediment concentrations was found in the lower Salinas River, California between 1967 and 2011. Event to decadal scale patterns in sediment production in the Salinas River have been found to be largely controlled by antecedent hydrologic conditions. Decreasing suspended sediment concentrations over the last 15years of the record departed from those expected from climatic/hydrologic forcing. Sediment production from the mountainous headwaters of the central California Coast Ranges is known to be dominated by the interaction of wildfire and large rainfall/runoff events, including the Arroyo Seco, an ~700km(2) subbasin of the Salinas River. However, the decreasing trend in Salinas River suspended sediment concentrations run contrary to increases in the watershed's effective burn area over time. The sediment source area of the Salinas River is an order of magnitude larger than that of the Arroyo Seco, and includes a more complicated mosaic of land cover and land use. The departure from hydrologic forcings on suspended sediment concentration patterns was found to coincide with a rapid conversion of irrigation practices from sprinkler and furrow to subsurface drip irrigation. Changes in agricultural operations appear to have decreased sediment supply to the Salinas River over the late 20th to early 21st centuries, obscuring the influence of wildfire on suspended sediment production. PMID:26974570

  12. Abundance and Morphological Effects of Large Woody Debris in Forested Basins of Southern Andes

    NASA Astrophysics Data System (ADS)

    Andreoli, A.; Comiti, F.; Lenzi, M. A.

    2006-12-01

    The Southern Andes mountain range represents an ideal location for studying large woody debris (LWD) in streams draining forested basins thanks to the presence of both pristine and managed woodland, and to the general low level of human alteration of stream corridors. However, no published investigations have been performed so far in such a large region. The investigated sites of this research are three basins (9-13 km2 drainage area, third-order channels) covered by Nothofagus forests: two of them are located in the Southern Chilean Andes (the Tres Arroyos in the Malalcahuello National Reserve and the Rio Toro within the Malleco Natural Reserve) and one basin lies in the Argentinean Tierra del Fuego (the Buena Esperanza basin, near the city of Ushuaia). Measured LWD were all wood pieces larger than 10 cm in diameter and 1 m in length, both in the active channel and in the adjacent active floodplain. Pieces forming log jams were all measured and the geometrical dimensions of jams were taken. Jam type was defined based on Abbe and Montgomery (2003) classification. Sediment stored behind log-steps and valley jams was evaluated approximating the sediment accumulated to a solid wedge whose geometrical dimensions were measured. Additional information relative to each LWD piece were recorded during the field survey: type (log, rootwad, log with rootwads attached), orientation to flow, origin (floated, bank erosion, landslide, natural mortality, harvest residuals) and position (log-step, in-channel, channel-bridging, channel margins, bankfull edge). In the Tres Arroyos, the average LWD volume stored within the bankfull channel is 710 m3 ha-1. The average number of pieces is 1,004 per hectare of bankfull channel area. Log-steps represent about 22% of all steps, whereas the elevation loss due to LWD (log-steps and valley jams) results in 27% loss of the total stream potential energy. About 1,600 m3 of sediment (assuming a porosity of 20%) is stored in the main channel

  13. Pasadena, California Anaglyph with Aerial Photo Overlay

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This anaglyph shows NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California. Red-blue glasses are required to see the 3-D effect. The surrounding residential areas of La Canada-Flintridge (to the left) and Altadena/Pasadena (to the right) are also shown. JPL is located at the base of the San Gabriel Mountains, an actively growing mountain range, seen towards the top of the image. The large canyon coming out of the mountains (top to bottom of image) is the Arroyo Seco, which is a major drainage channel for the mountains. Sand and gravel removal operations in the lower part of the arroyo (bottom of image) are removing debris brought down by flood and mudflow events. Old landslide scars (lobe-shaped features) are seen in the arroyo, evidence that living near steep canyon slopes in tectonically active areas can be hazardous. The data can also be utilized by recreational users such as hikers enjoying the natural beauty of these rugged mountains.

    This anaglyph was generated using topographic data from the Shuttle Radar Topography Mission to create two differing perspectives of a single image, one perspective for each eye. The detailed aerial image was provided by U. S. Geological Survey digital orthophotography. Each point in the image is shifted slightly, depending on its elevation. When viewed through special glasses, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and cover the right eye with a blue filter.

    The Shuttle Radar Topography Mission (SRTM), launched on February 11,2000, uses the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. The mission is designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, an additional C-band imaging antenna

  14. Large wood storage, longitudinal distribution and mobility in channel segments of four mountain rivers, Chile

    NASA Astrophysics Data System (ADS)

    Iroume, A.; Mao, L.; Andreoli, A.; Ulloa, H.

    2013-12-01

    In Chile, besides an anecdotal reference to in-stream wood by Vidal Gormaz (1875), the first report on LW is the one by Andreoli et al. (2007). Since then, more abundant research has developed, focusing mainly on morphologic and hydraulic functions (Comiti et al., 2008; Mao et al., 2008, 2010; Iroumé at al., 2010, 2011; Ulloa et al., 2011), and also on the ecology of low order channels (Vera et al., 2012). Large wood storage, longitudinal distribution and mobility have been studied for several periods in channel segments of four mountain catchments (Pichún, El Toro, Tres Arroyos and Vuelta de Zorra) in southern Chile. The surveyed segments were divided into individual reaches, and the length of each reach was calculated using a laser distance meter and mean individual reach bankfull width and depth were obtained by averaging measurements in cross-sections. All wood pieces found within the bankfull channel more than 10 cm in diameter and 1 m in length were measured and their position was referenced to natural elements and to numbered wooden stakes indicating every reach limit. Several of these wood elements were tagged to study LW mobilization. A 1.54 km-long segment divided into 17 individual reaches was first surveyed in the Tres Arroyos during March-April 2005, and then re-surveyed in November 2008 when the study segment was extended to a total length of 2.07 km with the addition of 5 new individual reaches. Pichún, El Toro and Vuelta de Zorra were first surveyed from November 2008 to February 2009. The length of the channel segments is 1.0 (12 reaches), 2.2 (17 reaches) and 1.56 km (16 reaches) for Pichún, El Toro and Vuelta de Zorra, respectively. These segments have been re-surveyed after every winter rainy season to study LW recruitment and mobility. Using the area of the bankfull channel as reference, total LW volume was 54 m3/ha in Pichún, 202 m3/ha in El Toro, 1449 m3/ha for Tres Arroyos and 109 m3/ha for Vuelta de Zorra. The LW travel distance and

  15. Rock magnetic characterization of faulted sediments with associated magnetic anomalies in the Albuquerque Basin, Rio Grande rift, New Mexico

    USGS Publications Warehouse

    Hudson, M.R.; Grauch, V.J.S.; Minor, S.A.

    2008-01-01

    Variations in rock magnetic properties are responsible for the many linear, short-wavelength, low-amplitude magnetic anomalies that are spatially associated with faults that cut Neogene basin sediments in the Rio Grande rift, including the San Ysidro normal fault, which is well exposed in the northern part of the Albuquerque Basin. Magnetic-susceptibility measurements from 310 sites distributed through a 1200-m-thick composite section of rift-filling sediments of the Santa Fe Group and prerift Eocene and Cretaceous sedimentary rocks document large variations of magnetic properties juxtaposed by the San Ysidro fault. Mean volume magnetic susceptibilities generally increase upsection through eight map units: from 1.7 to 2.2E-4 in the prerift Eocene and Cretaceous rocks to 9.9E-4-1.2E-3 in three members of the Miocene Zia Formation of the Santa Fe Group to 1.5E-3-3.5E-3 in three members of the Miocene-Pleistocene Arroyo Ojito Formation of the Santa Fe Group. Rock magnetic measurements and petrography indicate that the amount of detrital magnetite and its variable oxidation to maghemite and hematite within the Santa Fe Group sediments are the predominant controls of their magnetic property variations. Magnetic susceptibility increases progressively with sediment grain size within the members of the Arroyo Ojito Formation (deposited in fluvial environments) but within members of the Zia Formation (deposited in mostly eolian environments) reaches highest values in fine to medium sands. Partial oxidation of detrital magnetite is spatially associated with calcite cementation in the Santa Fe Group. Both oxidation and cementation probably reflect past flow of groundwater through permeable zones. Magnetic models for geologic cross sections that incorporate mean magnetic susceptibilities for the different stratigraphic units mimic the aeromagnetic profiles across the San Ysidro fault and demonstrate that the stratigraphic level of dominant magnetic contrast changes with

  16. Emergency Assessment of Postfire Debris-Flow Hazards for the 2009 Station Fire, San Gabriel Mountains, Southern California

    USGS Publications Warehouse

    Cannon, Susan H.; Gartner, Joseph E.; Rupert, Michael G.; Michael, John A.; Staley, Dennis M.; Worstell, Bruce B.

    2009-01-01

    This report presents an emergency assessment of potential debris-flow hazards from basins burned by the 2009 Station fire in Los Angeles County, southern California. Statistical-empirical models developed for postfire debris flows are used to estimate the probability and volume of debris-flow production from 678 drainage basins within the burned area and to generate maps of areas that may be inundated along the San Gabriel mountain front by the estimated volume of material. Debris-flow probabilities and volumes are estimated as combined functions of different measures of basin burned extent, gradient, and material properties in response to both a 3-hour-duration, 1-year-recurrence thunderstorm and to a 12-hour-duration, 2-year recurrence storm. Debris-flow inundation areas are mapped for scenarios where all sediment-retention basins are empty and where the basins are all completely full. This assessment provides critical information for issuing warnings, locating and designing mitigation measures, and planning evacuation timing and routes within the first two winters following the fire. Tributary basins that drain into Pacoima Canyon, Big Tujunga Canyon, Arroyo Seco, West Fork of the San Gabriel River, and Devils Canyon were identified as having probabilities of debris-flow occurrence greater than 80 percent, the potential to produce debris flows with volumes greater than 100,000 m3, and the highest Combined Relative Debris-Flow Hazard Ranking in response to both storms. The predicted high probability and large magnitude of the response to such short-recurrence storms indicates the potential for significant debris-flow impacts to any buildings, roads, bridges, culverts, and reservoirs located both within these drainages and downstream from the burned area. These areas will require appropriate debris-flow mitigation and warning efforts. Probabilities of debris-flow occurrence greater than 80 percent, debris-flow volumes between 10,000 and 100,000 m3, and high

  17. Human and Host Species Transferrin Receptor 1 Use by North American Arenaviruses

    PubMed Central

    Zong, Min; Fofana, Isabel

    2014-01-01

    ABSTRACT At least five New World (NW) arenaviruses cause hemorrhagic fevers in South America. These pathogenic clade B viruses, as well as nonpathogenic arenaviruses of the same clade, use transferrin receptor 1 (TfR1) of their host species to enter cells. Pathogenic viruses are distinguished from closely related nonpathogenic ones by their additional ability to utilize human TfR1 (hTfR1). Here, we investigate the receptor usage of North American arenaviruses, whose entry proteins share greatest similarity with those of the clade B viruses. We show that all six North American arenaviruses investigated utilize host species TfR1 orthologs and present evidence consistent with arenavirus-mediated selection pressure on the TfR1 of the North American arenavirus host species. Notably, one of these viruses, AV96010151, closely related to the prototype Whitewater Arroyo virus (WWAV), entered cells using hTfR1, consistent with a role for a WWAV-like virus in three fatal human infections whose causative agent has not been identified. In addition, modest changes were sufficient to convert hTfR1 into a functional receptor for most of these viruses, suggesting that a minor alteration in virus entry protein may allow these viruses to use hTfR1. Our data establish TfR1 as a cellular receptor for North American arenaviruses, highlight an “arms race” between these viruses and their host species, support the association of North American arenavirus with fatal human infections, and suggest that these viruses have a higher potential to emerge and cause human diseases than has previously been appreciated. IMPORTANCE hTfR1 use is a key determinant for a NW arenavirus to cause hemorrhagic fevers in humans. All known pathogenic NW arenaviruses are transmitted in South America by their host rodents. North American arenaviruses are generally considered nonpathogenic, but some of these viruses have been tentatively implicated in human fatalities. We show that these North American

  18. Late Quaternary Offset of Alluvial Fan Surfaces along the Central Sierra Madre Fault, Southern California

    NASA Astrophysics Data System (ADS)

    Hanson, A.; Burgette, R. J.; Scharer, K. M.; Midttun, N. C.

    2015-12-01

    The Sierra Madre fault (SMF) is an east-west trending reverse fault system along the southern flank of the San Gabriel Mountains near Los Angeles, California. The ~140 km long SMF is separated into four segments, we focus on the multi-stranded, ~60 km long Central Sierra Madre fault (CSMF; W118.3-W117.7) as it lacks a well-characterized long-term geologic slip rate. We combine 1-m lidar DEM with geologic and geomorphic mapping to correlate alluvial fan surfaces along strike and across the fault strands in order to derive fault slip rates that cross the CSMF. We have refined mapping on two sets of terraces described by Crook et al. (1987) and references therein: a flight of Q3 surfaces (after nomenclature of Crook et al., 1987; McFadden, 1982) in Arroyo Seco with distinct terraces ~30 m, ~40 m, ~50 m, and ~55 m above the modern stream and in Pickens Canyon divided a Q3 and Q2 surface, with heights that are ~35 m and ~25 m above the modern stream respectively. Relative degree of clast weathering and soil development is consistent with geomorphic relationships; for example, hues of 7.5 YR to 10 YR are typical of Q3, while hues of 10 YR to 2.5 Y are typical of Q2. A scarp in the Q3 surface at Arroyo Seco has a vertical offset of ~16 m and a scarp in the Q3 at Pickens Canyon has a vertical offset of ~14 m, while the Q2 surface is not faulted. Our Quaternary dating strategy is focused on dating suites of terraces offset along CSMF scarps in order to provide broader stratigraphic context for the cosmogenic radionuclide and luminescence dating. We will present (pending) cosmogenic radionuclide depth profiles from the Q3 surfaces. A better-constrained slip rate for the CSMF will improve earthquake hazard assessment for the Los Angeles area and help clarify the tectonic role of the SMF in the broader plate boundary system. Additionally, the fan chronology will provide information about the timing of alluvial fan aggradation and incision in the western Transverse Ranges.

  19. Delineating incised stream sediment sources within a San Francisco Bay tributary basin

    NASA Astrophysics Data System (ADS)

    Bigelow, Paul; Benda, Lee; Pearce, Sarah

    2016-07-01

    Erosion and sedimentation pose ubiquitous problems for land and watershed managers, requiring delineation of sediment sources and sinks across landscapes. However, the technical complexity of many spatially explicit erosion models precludes their use by practitioners. To address this critical gap, we demonstrate a contemporary use of applied geomorphometry through a straightforward GIS analysis of sediment sources in the San Francisco Bay Area in California, USA, designed to support erosion reduction strategies. Using 2 m lidar digital elevation models, we delineated the entire river network in the Arroyo Mocho watershed (573 km2) at the scale of ˜ 30 m segments and identified incised landforms using a combination of hillslope gradient and planform curvature. Chronic erosion to the channel network was estimated based on these topographic attributes and the size of vegetation, and calibrated to sediment gage data, providing a spatially explicit estimate of sediment yield from incised channels across the basin. Rates of erosion were summarized downstream through the channel network, revealing patterns of sediment supply at the reach scale. Erosion and sediment supply were also aggregated to subbasins, allowing comparative analyses at the scale of tributaries. The erosion patterns delineated using this approach provide land use planners with a robust framework to design erosion reduction strategies. More broadly, the study demonstrates a modern analysis of important geomorphic processes affected by land use that is easily applied by agencies to solve common problems in watersheds, improving the integration between science and environmental management.

  20. Co-occurrence of mylodontid sloths and insights on their potential distributions during the late Pleistocene

    NASA Astrophysics Data System (ADS)

    Varela, Luciano; Fariña, Richard A.

    2016-01-01

    Species distribution models (SDMs) for the last interglacial (LIG), the global last glacial maximum (LGM) and the Holocene climatic optimum (HCO) were generated for three extinct South American Pleistocene mylodontid giant sloths, Glossotherium robustum, Lestodon armatus and Mylodon darwinii. They are recorded co-occurring in some localities including Arroyo del Vizcaíno site (AdV) in Uruguay. Co-occurrence records were studied based on the overlap of their generated areas of potential distributions, and compared with the available biome reconstructions of South America during the LGM to analyze their distribution patterns, ecological requirements and possible interactions between them. Our results suggest that these sloths could have co-existed mainly in the Chaco-Paraná Basin and the plains in the Río de la Plata area. Areas of high suitability were observed for submerged parts of the continental shelf that were exposed during the LGM showing an overall increase in potential habitat compared to the LIG and HCO. This suggests that there was a drastic reduction in total available areas of preferred habitat at the end of the Pleistocene. The co-occurrence of these sloths at the AdV site suggests the presence of vegetation indicative of mainly open, cold to temperate habitats but with mixed patches typical of humid climates.

  1. Assessing the importance of four sandfly species (Diptera: Psychodidae) as vectors of Leishmania mexicana in Campeche, Mexico.

    PubMed

    Pech-May, A; Peraza-Herrera, G; Moo-Llanes, D A; Escobedo-Ortegón, J; Berzunza-Cruz, M; Becker-Fauser, I; Montes DE Oca-Aguilar, A C; Rebollar-Téllez, E A

    2016-09-01

    Localized cutaneous leishmaniasis represents a public health problem in many areas of Mexico, especially in the Yucatan Peninsula. An understanding of vector ecology and bionomics is of great importance in evaluations of the transmission dynamics of Leishmania parasites. A field study was conducted in the county of Calakmul, state of Campeche, during the period from November 2006 to March 2007. Phlebotomine sandfly vectors were sampled using Centers for Disease Control light traps, baited Disney traps and Shannon traps. A total of 3374 specimens were captured in the two villages of Once de Mayo (93.8%) and Arroyo Negro (6.1%). In Once de Mayo, the most abundant species were Psathyromyia shannoni, Lutzomyia cruciata, Bichromomyia olmeca olmeca and Psychodopygus panamensis (all: Diptera: Psychodidae). The Shannon trap was by far the most efficient method of collection. The infection rate, as determined by Leishmania mexicana-specific polymerase chain reaction, was 0.3% in Once de Mayo and infected sandflies included Psy. panamensis, B. o. olmeca and Psa. shannoni. There were significant differences in human biting rates across sandfly species and month of sampling. Ecological niche modelling analyses showed an overall overlap of 39.1% for the four species in the whole state of Campeche. In addition, the finding of nine vector-reservoir pairs indicates a potential interaction. The roles of the various sandfly vectors in Calakmul are discussed. PMID:27040367

  2. Trace elements and organic compounds associated with riverbed sediments in the Rio Grande/Rio Bravo basin, Mexico and Texas

    USGS Publications Warehouse

    Lee, R.W.; Wilson, J.T.

    1997-01-01

    In 1991, the Texas Natural Resource Conservation Commission (TNRCC) was mandated by the Texas Clean Rivers Act (Senate Bill 818) to assess water quality of rivers in Texas. Recent efforts to collect information for the assessment of water quality in the Rio Grande/Rio Bravo Basin have involved Federal agencies on both sides of the 1,248-mile U.S.-Mexico border?U.S. Environmental Protection Agency, U.S. Geological Survey (USGS), Secretaria de Desarollo Social (Secretary for Social Development, Mexico), National Water Commission of Mexico, and International Boundary and Water Commission?as well as State and local agencies in a spirit of international cooperation. Substantial efforts have been made to gather data needed to determine the quality of water and ecological status of the Rio Grande/Rio Bravo, especially at sites along the border (fig. 1). The purpose of this report is to assess selected historical data of trace elements and organic compounds in riverbed sediments of the Rio Grande/Rio Bravo, and of the Pecos River and the Arroyo Colorado in Texas.

  3. Elevation changes in the central transverse ranges near Ventura, California

    USGS Publications Warehouse

    Buchanan-Banks, J. M.; Castle, R.O.; Ziony, J.I.

    1975-01-01

    Profiles of elevation changes developed from repeated levelings in the east-trending Transverse Ranges near Ventura, California, reveal three general types of vertical movements: 1. (1) broadly defined regional tilting; 2. (2) sharply defined differential movements across recently active faults; and 3. (3) differential subsidence centering on producing oil fields. Down-to-the-southeast tilting is evident in profiles along the coast this sense of movement, however, is the inverse of that that may have prevailed during late Pleistocene time. Profiles along lines extending north and northwest from Ventura show prominent inflections formed by up-to-the-north differential movements that coincide roughly with the Red Mountain fault; this fault is a north-dipping reverse fault that displaces a Holocene(?) soil zone and along which scarps and sag ponds are preserved. A similar inflection coincides with the Padre Juan fault; post-Pleistocene activity on the Padre Juan, however, is uniquely indicated by the geodetic data. Contemporary integrity of the structural block extending northward from the Red Mountain fault is suggested by the apparent absence of differential movements across the Munson Creek, Tule Creek, Santa Ynez, and Arroyo Parida faults since at least 1934. Subsidence is recognized over both the Ventura and Rincon oil fields; although maximum subsidence has not been recorded in either case, 277 mm of differential subsidence was measured within the Ventura field between 1934 and 1968. ?? 1975.

  4. Using a watershed-based approach to manage and protect water resources in the Bear Canyon Watershed, Albuquerque, New Mexico

    SciTech Connect

    Roth, F.J.

    1995-12-31

    Depending upon how people use land in a watershed, whether it be farming, livestock grazing, timber harvesting, mining, urbanization, or even recreation, all have significant impacts on the water moving through that watershed. This paper will focus on the urban watershed and how stormwater runoff from urbanization affects erosion, sedimentation, and water quality. It also will explore the potential of a watershed as the basis for managing and protecting water resources. Watershed-based management offers a clear look at how land-use changes affect not only water quality but also erosion and sedimentation; in addition, this approach develops preventive strategies to restore those affected water and land resources. The preventive strategies the author uses for this watershed can be applied to other New Mexico urban watersheds. This paper is divided into three parts. The first part shows how past and present land-use activities affect erosion, sedimentation, and water quality in the Bear Canyon arroyo system. The second part provides solutions to the problems of soil erosion and stormwater pollution in the urban areas through government intervention. The third part discusses how Best Management Practices (BMPs) can be used to limit or reduce stormwater pollution in residential and industrial areas.

  5. Diversity among Tacaribe Serocomplex Viruses (Family Arenaviridae) Associated with the Southern Plains Woodrat (Neotoma micropus)

    PubMed Central

    Cajimat, Maria N. B.; Milazzo, Mary Louise; Mauldin, Matthew R.; Bradley, Robert D.; Fulhorst, Charles F.

    2014-01-01

    The southern plains woodrat (Neotoma micropus) is the principal host of Catarina virus in southern Texas and a natural host of other North American Tacaribe serocomplex viruses. The objectives of this study were to increase our knowledge of the genetic diversity among Tacaribe serocomplex viruses associated with N. micropus and to define better the natural host relationships of these viruses. Pairwise comparisons of complete glycoprotein precursor gene sequences and complete nucleocapsid protein gene sequences revealed a high level of genetic diversity among Tacaribe serocomplex viruses associated with N. micropus in western Oklahoma, southern New Mexico, and northern and southern Texas. Collectively, the results of Bayesian analyses of nucleotide sequences and pairwise comparisons of amino acid sequences confirmed that the arenaviruses associated with N. micropus in Oklahoma and New Mexico should be included in the Whitewater Arroyo species complex, and indicated that that the arenaviruses associated with N. micropus in northern Texas are strains of a novel arenaviral species – tentatively named “Middle Pease River virus”. Together, the results of assays for arenavirus and assays for anti-arenavirus antibody in 54 southern plains woodrats and 325 other rodents captured at 2 localities suggested that the southern plains woodrat is the principal host of Middle Pease River virus in northern Texas. PMID:24161346

  6. Coeval Ar-40/Ar-39 ages of 65.0 million years ago from Chicxulub crater melt rock and Cretaceous-Tertiary boundary tektites

    NASA Technical Reports Server (NTRS)

    Swisher, Carl C., III; Grajales-Nishimura, Jose M.; Montanari, Alessandro; Margolis, Stanley V.; Claeys, Philippe; Alvarez, Walter; Renne, Paul; Cedillo-Pardo, Esteban; Maurrasse, Florentin J.-M. R.; Curtis, Garniss H.

    1992-01-01

    Ar-40/Ar-39 dating of drill-core samples of a glassy melt rock recovered from beneath a massive impact breccia contained with the 180-kilometer subsurface Chicxulub crater yields well-behaved incremental heating spectra with a mean plateau age of 64.98 +/- 0.05 million years ago (Ma). The glassy melt rock of andesitic composition was obtained from core 9 (1390 to 1393 meters) in the Chicxulub 1 well. The age of the melt rock is virtually indistinguishable from Ar-40/Ar-39 ages obtained on tektite glass from Beloc, Haiti, and Arroyo el Mimbral, northeastern Mexico, of 65.01 +/- 0.08 Ma (mean plateau age for Beloc) and 65.07 +/- 0.10 Ma (mean total fusion age for both sites). The Ar-40/Ar-39 ages, in conjunction with geochemical and petrological similarities, strengthen the suggestion that the Chicxulub structure is the source for the Haitian and Mexican tektites and is a viable candidate for the Cretaceous-Tertiary boundary impact site.

  7. Coeval 40Ar/39Ar Ages of 65.0 Million Years Ago from Chicxulub Crater Melt Rock and Cretaceous-Tertiary Boundary Tektites.

    PubMed

    Swisher, C C; Grajales-Nishimura, J M; Montanari, A; Margolis, S V; Claeys, P; Alvarez, W; Renne, P; Cedillo-Pardoa, E; Maurrasse, F J; Curtis, G H; Smit, J; McWilliams, M O

    1992-08-14

    (40)Ar/(39)Ar dating of drill core samples of a glassy melt rock recovered from beneath a massive impact breccia contained within the 180-kilometer subsurface Chicxulub crater in Yucatán, Mexico, has yielded well-behaved incremental heating spectra with a mean plateau age of 64.98 +/- 0.05 million years ago (Ma). The glassy melt rock of andesitic composition was obtained from core 9 (1390 to 1393 meters) in the Chicxulub 1 well. The age of the melt rock is virtually indistinguishable from (40)Ar/(39)Ar ages obtained on tektite glass from Beloc, Haiti, and Arroyo el Mimbral, northeastern Mexico, of 65.01 +/- 0.08 Ma (mean plateau age for Beloc) and 65.07 +/- 0.10 Ma (mean total fusion age for both sites). The (40)Ar/(39)Ar ages, in conjunction with geochemical and petrological similarities, strengthen the recent suggestion that the Chicxulub structure is the source for the Haitian and Mexican tektites and is a viable candidate for the Cretaceous-Tertiary boundary impact site. PMID:17789640

  8. Landscapes of Santa Rosa Island, Channel Islands National Park, California

    USGS Publications Warehouse

    Schumann, R. Randall; Minor, Scott A.; Muhs, Daniel R.; Pigati, Jeffery S.

    2014-01-01

    Santa Rosa Island (SRI) is the second-largest of the California Channel Islands. It is one of 4 east–west aligned islands forming the northern Channel Islands chain, and one of the 5 islands in Channel Islands National Park. The landforms, and collections of landforms called landscapes, of Santa Rosa Island have been created by tectonic uplift and faulting, rising and falling sea level, landslides, erosion and deposition, floods, and droughts. Landscape features, and areas delineating groups of related features on Santa Rosa Island, are mapped, classified, and described in this paper. Notable landscapes on the island include beaches, coastal plains formed on marine terraces, sand dunes, and sand sheets. In this study, the inland physiography has been classified into 4 areas based on relief and degree of fluvial dissection. Most of the larger streams on the island occupy broad valleys that have been filled with alluvium and later incised to form steep- to vertical-walled arroyos, or barrancas, leaving a relict floodplain above the present channel. A better understanding of the processes and mechanisms that created these landscapes enhances visitors’ enjoyment of their surroundings and contributes to improving land and resource management strategies in order to optimize and balance the multiple goals of conservation, preservation, restoration, and visitor experience.

  9. Early Holocene human remains from the Argentinean Pampas: additional evidence for distinctive cranial morphology of early South Americans.

    PubMed

    Pucciarelli, Héctor M; Perez, S Ivan; Politis, Gustavo G

    2010-10-01

    The cranial morphology of Early Holocene American human samples is characterized by a long and narrow cranial vault, whereas more recent samples exhibit a shorter and wider cranial vault. Two hypotheses have been proposed to account for the morphological differences between early and late-American samples: (a) the migratory hypothesis that suggests that the morphological variation between early and late American samples was the result of a variable number of migratory waves; and (b) the local diversification hypothesis, that is, the morphological differences between early and late American samples were mainly generated by local, random (genetic drift), and nonrandom factors (selection and phenotypic plasticity). We present the first craniometric study of three early skulls from the Argentinean Pampas, dated ∼8,000 cal. years BP (Arroyo Seco 2, Chocorí, and La Tigra), and one associated with mega-faunal remains (Fontezuelas skull). In addition, we studied several Late Holocene samples. We show that the skulls from the Argentinean Pampas are morphologically similar to other Early Holocene American skulls (i.e., Lagoa Santa from Brazil, Tequendama, Checua, and Aguazuque from Colombia, Lauricocha from Peru, and early Mexicans) that exhibit long and narrow cranial vaults. These samples differ from the Late Holocene American samples that exhibit a shorter and wider cranial vault. Our results underscore the important differences in cranial morphology between early and late-American samples. However, we emphasize the need for further studies to discuss alternative hypotheses regarding such differences. PMID:20623674

  10. The church, the state and women's bodies in the context of religious fundamentalism in the Philippines.

    PubMed

    Ruiz Austria, Carolina S

    2004-11-01

    After almost 500 years of Spanish colonial rule, Canon law and laws of Spanish origin continue to dominate Philippine family, civil and penal law. Most if not all of these laws place serious limitations on the realisation of women's sexual and reproductive rights. Since 2002, the current president, Gloria Mocapagal Arroyo, has increasingly substituted church dogma for state policy, i.e. revoking the reproductive health and family planning policies of her predecessor, rejecting all modern contraceptive methods as forms of abortion, limiting government support for family planning to providing natural methods to married couples, and restricting access to emergency contraception. This article reflects on which advocacy methods will best serve the goals of sexual and reproductive rights when conservative church interests dominate state policy, as is currently the case in the Philippines. Religious fundamentalists, at one and the some time, argue for religious accommodation of their views by the state on the grounds of religious freedom but refuse to entertain, let alone accommodate, a plurality of views on women's sexuality. Thus, it is not enough to base a case in support of sexual and reproductive rights on the separation of church and state since, even though the State claims it is secular, it still manages to impose restrictions and control over women's bodies. PMID:15626200

  11. Effects of the catastrophic flood of December 1966, north rim area, eastern Grand Canyon, Arizona

    USGS Publications Warehouse

    Cooley, Maurice E.; Aldridge, B.N.; Euler, Robert C.

    1977-01-01

    Precipitation from the unusual storm of December 1966 was concentrated on highlands in northern Arizona, southwestern Utah , southern Nevada, and south-central California and caused widely scattered major floods in the four States. In Arizona the largest amount of precipitation was in the north rim area of eastern Grand Canyon, where about 14 inches was measured. The largest flows occurred along Bright Angel Creek and the MilK Creek-Dragon Creek part of the Crystal Creek drainage basin. The maximum effects of the flood were along Milk Creek-Dragon Creek, where a mudflow caused extensive channel modification. Floods that occurred in the Bright Angel and Crystal Creek basins have a recurrence interval of only once in several centuries. The streamflow that resulted from the storm on the Kaibab Plateau caused considerable local scouring and deepening of channels, including some renewed arroyo cutting. The most catastrophic effects of the 1966 floods were caused by two mudflows that extended from the edge of the Kaibab Plateau along Dragon Creek in the Crystal Creek basin and Lava Creek in the Chuar Creek basin to the Colorado River. More than 10 other large mudflows occurred in Nankoweap, Kwagunt, Crystal, and Shinumo Creek basins. About 80 large debris slides left conspicuous scars in the amphitheaters at the heads of the side gorges, and at least 10 small slides occurred on the Kaibab Plateau. (Woodard-USGS)

  12. Rainfall, runoff, and water-quality data for the urban storm-water program in the Albuquerque, New Mexico, metropolitan area, water year 2004

    USGS Publications Warehouse

    Kelly, Todd; Romero, Orlando; Jimenez, Mike

    2006-01-01

    Urbanization has dramatically increased precipitation runoff to the system of drainage channels and natural stream channels in the Albuquerque, New Mexico, metropolitan area. Rainfall and runoff data are important for planning and designing future storm-water conveyance channels in newly developing areas. Storm-water quality also is monitored in accordance with the National Pollutant Discharge Elimination System mandated by the U.S. Environmental Protection Agency. The Albuquerque Metropolitan Arroyo Flood Control Authority, the City of Albuquerque, and the U.S. Geological Survey began a cooperative program to collect hydrologic data to assist in assessing the quality and quantity of surface-water resources in the Albuquerque area. This report presents water-quality, streamflow, and rainfall data collected from October 1, 2003, to September 30, 2004 (water year 2004). Also provided is a station analysis for each of the 18 streamflow-gaging sites and 39 rainfall-gaging sites, which includes a description of monitoring equipment, problems associated with data collection during the year, and other information used to compute streamflow discharges or rainfall records. A hydrographic comparison shows the effects that the largest drainage channel in the metropolitan area, the North Floodway Channel, has on total flow in the Rio Grande.

  13. Ecotoxicity in the Reconquista River, province of Buenos Aires, Argentina: a preliminary study.

    PubMed Central

    Herkovits, J; Perez-Coll, C S; Herkovits, F D

    1996-01-01

    The Reconquista River in Argentina is considered a "supercritical" river basin due to environmental degradation. Within its valley of 1.547 km2, there are more than 3 million inhabitants and 12,000 industries. Using early-life-stage toxicity tests with Bufo arenarum embryos (the most sensitive of three native species), we determined the water quality at six sampling stations of the river valley and expressed the results as acute and chronic toxicity units. Along most of the river, the toxicity was higher than the allowable level of whole industrial effluent toxicity recommended by U.S. EPA. In a tributary stream, Arroyo Moron, the water was about 10 times more toxic than the criteria maximum concentration (CMC) recommended by U.S. EPA for industrial effluents. Similar degradation of the water quality was found taking as a reference value an upstream sampling station. In all places where the water quality was worse than the CMC, no macroorganisms were found, and in one of these places, a large number of dead fishes was observed. Our study points out that amphibian early-life-stage toxicity tests could be appropriate for assessing water contamination and water quality, which is essential for diagnosis, protection of environmental services, monitoring, and restoration purposes. Images Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. PMID:8820587

  14. A water-resources data network evaluation for Monterey County, California; Phase 1; South county

    USGS Publications Warehouse

    Showalter, P.K.; Hord, S.H.

    1986-01-01

    An evaluation made of rainfall, surface water, groundwater, and water quality monitoring networks in Salinas River basin in southern Monterey County, California, proposed all long-term rain gages be continued for extending short-term records and suggested the installation of two additional recording gages. Eight new storage rain gages were suggested at midaltitudes of east and west sides of Salinas Valley where few data are available. The evaluation revealed some short-term gaging stations could be discontinued because of good regression relations between them and the long-term stations Arroyo Seco near Soledad. Of 16 stations selected for the proposed network, 4 are new recording stations, 6 are new nonrecording streamflow and water quality sampling sites, 5 are existing stations, and the last is a station operated from 1969 to 1976; also included are water quality sampling stations on Lakes Nacimiento and San Antonio. The proposed groundwater network was developed from information on geology, geohydrology, and groundwater quality, high priority objectives for groundwater network, and consideration for providing good areal coverage of levels and water quality. Of 145 sites selected, 86 are existing monitoring wells. (USGS)

  15. A Multivalent and Cross-Protective Vaccine Strategy against Arenaviruses Associated with Human Disease

    PubMed Central

    Kotturi, Maya F.; Botten, Jason; Sidney, John; Bui, Huynh-Hoa; Giancola, Lori; Maybeno, Matt; Babin, Josie; Oseroff, Carla; Pasquetto, Valerie; Greenbaum, Jason A.; Peters, Bjoern; Ting, Joey; Do, Danh; Vang, Lo; Alexander, Jeff; Grey, Howard; Buchmeier, Michael J.; Sette, Alessandro

    2009-01-01

    Arenaviruses are the causative pathogens of severe hemorrhagic fever and aseptic meningitis in humans, for which no licensed vaccines are currently available. Pathogen heterogeneity within the Arenaviridae family poses a significant challenge for vaccine development. The main hypothesis we tested in the present study was whether it is possible to design a universal vaccine strategy capable of inducing simultaneous HLA-restricted CD8+ T cell responses against 7 pathogenic arenaviruses (including the lymphocytic choriomeningitis, Lassa, Guanarito, Junin, Machupo, Sabia, and Whitewater Arroyo viruses), either through the identification of widely conserved epitopes, or by the identification of a collection of epitopes derived from multiple arenavirus species. By inoculating HLA transgenic mice with a panel of recombinant vaccinia viruses (rVACVs) expressing the different arenavirus proteins, we identified 10 HLA-A02 and 10 HLA-A03-restricted epitopes that are naturally processed in human antigen-presenting cells. For some of these epitopes we were able to demonstrate cross-reactive CD8+ T cell responses, further increasing the coverage afforded by the epitope set against each different arenavirus species. Importantly, we showed that immunization of HLA transgenic mice with an epitope cocktail generated simultaneous CD8+ T cell responses against all 7 arenaviruses, and protected mice against challenge with rVACVs expressing either Old or New World arenavirus glycoproteins. In conclusion, the set of identified epitopes allows broad, non-ethnically biased coverage of all 7 viral species targeted by our studies. PMID:20019801

  16. Public opinion and interest group positions on open-space issues in Albuquerque, New Mexico, USA: Implications for resource management

    NASA Astrophysics Data System (ADS)

    Tannery, Thomas Allan

    1987-07-01

    The purpose of this research was to elicit and compare the open-space preferences of citizens and openspace experts in Albuquerque, New Mexico, USA. A randomly selected sample of 492 citizens and 35 open-space experts participated in a telephone survey during May 5 18, 1986. The following hypothesis was tested and used as a guideline for the study: HO1: There is no significant difference between respondents' status and preference for open space in Albuquerque, New Mexico. The hypothesis was rejected. Findings confirmed respondents' status affected preference for open space. Of the eight issues on which the citizen and expert groups were compared, five recorded significant differences in response profiles. The open-space expert group was significantly more supportive of using open space to accommodate offroad vehicle facilities, wildlife preserves, a citywide recreational trail, and a trail system along the arroyos and city ditches. The citizen sample was significantly more supportive of using open space to accommodate overnight camping facilities. Both groups equally supported using open space to accommodate an outdoor amphitheater, outdoor education facilities, and rafting, kayaking, and canoeing facilities. The finding indicated that expert preferences did not represent an aggregate of citizen preferences for managing open-space resources. Understanding both expert and citizen positions will facilitate decision-making processes and help resolve environmental disputes.

  17. Presence of Oxyodontherium (Macraucheniidae, Litopterna) in the Río Quinto Formation, San Luis (Argentina)

    NASA Astrophysics Data System (ADS)

    Cerdeño, Esperanza; Chiesa, Jorge; Ojeda, Guillermo

    2008-03-01

    This paper deals with the new mammal remains from the Río Quinto Formation, found at the Arroyo La Petra locality (San Luis, Argentina). They consist of an incomplete skull and two mandibular fragments of a macraucheniid, both with milk dentition and M1/m1 erupting, corresponding to a very young individual. Morfometrical characteristics of the specimens allow their identification as Oxyodontherium zeballosi and provide the first cranial data for this species. The holotype of this species is considered a juvenile individual. We maintain a conservative position in maintaining O. zeballosi as a valid species though based on juvenile specimens. However, a full systematic revision of the Family Macraucheniidae is needed to verify the validity and phylogenetic relationships of the taxa included in it. The identification of O. zeballosi indicates a late Miocene age for the fossiliferous level, which implies a cronoestratigraphic extension of the Río Quinto Formation, thus far considered as Pliocene in age. In addition, the presence of Oxyodontherium in San Luis Province increases the geographical distribution of this macrauchenid, whose record previously was limited to Miocene outcrops of the Paraná River (Entre Ríos Province). Its presence in the Mio-Pliocene beds of Uruguay is very doubtful because it is based on a metapodial.

  18. Application of ERTS-1 imagery to detecting and mapping modern erosion features and to monitoring erosional changes, in southern Arizona

    NASA Technical Reports Server (NTRS)

    Morrison, R. B. (Principal Investigator); Cooley, M. E.

    1973-01-01

    The author has identified the following significant results. The chief results during the reporting period were three 1:1,000,000 scale maps made from one ERTS-1 frame (1085-17330, 16 October 1972) showing: (1) the three most important types of materials in terms of the modern erosion problem: the readily erodible soils, gravel piedmonts and basin-fill areas, and consolidated rocks; (2) alluvial fans (dissected and relatively undissected); and (3) (as an additional bonus) linear structural features. Eight key areas (small parts of the whole study area) were selected for detailed study, and mapping was started in two of them, by interpretation of ultrahigh (U-2 and RB-57) airphotos, supplemented by field studies. In these areas detailed mapping was done not only on the modern erosion phenomena (arroyos, gullies, modern flood plains and terraces, and areas of sheet erosion and deposition), but also other features pertinent to the erosion problem, such as slope-local relief, landforms rock units, soil particle size and erodibility, and classes of vegetative cover.

  19. Uranium-series ages of marine terraces, La Paz Peninsula, Baja California Sur, Mexico

    USGS Publications Warehouse

    Sirkin, L.; Szabo, B. J.; Padilla, G.A.; Pedrin, S.A.; Diaz, E.R.

    1990-01-01

    Uranium-series dating of coral samples from raised marine terrace deposits between 1.5 and 10 m above sea level in the La Paz Peninsula area, Baja California Sur, yielded ages between 123 ka and 138 ka that are in agreement with previously reported results. The stratigraphy and ages of marine units near the El Coyote Arroyo indicate the presence of two high stands of the sea during the last interglacial or oxygen isotope substage 5e at about 140 ka and 123 ka. Accepting 5 m for the sea level during the last interglacial transgression, we calculate average uplift rates for the marine terraces of about ???70 mm/ka and 40 mm/ka. These slow rates of uplift indicate a relative stability of the La Paz peninsula area for the past 140 000 years. In contrast, areas of Baja California affected by major faultf experienced higher rates of uplift. Rockwell et al. (1987) reported vertical uplift rates of 180 to 300 mm/ka at Punta Banda within the Aqua Blanea fault zone in northern Baja California. ?? 1990 Springer-Verlag.

  20. Remote sensing and hydrologic modeling of arid watersheds: A scale analysis: Progress report

    SciTech Connect

    Not Available

    1988-01-01

    The ultimate goal of this multiyear research effort is to model long-term (10/sup 2/--10/sup 4/ yrs), cut and fill cycles in arid region fluvial systems (arroyos). Historic and geologic (late Quaternary) data bases indicate that arid region fluvial systems have oscillated between periods of pronounced aggradation and degradation. This cyclic behavior has affected both water and sediment discharge from arid watersheds as well as ecosystem habitats along hillslopes and valley bottoms. One of the primary causes that has been proposed for this cyclic activity is climatic change for gradual (glacial-interglacial) and catastrophic (volcanic eruptions, el Nino) rates of climatic change on a global scale. The immediate goal of this multiyear research effort is to modify existing numeric hydrologic models (SPUR, KINEROS) which utilize as input multilayered, co-registered remotely sensed data for the prediction of surface hydrology and sediment erosion, transport and deposition in arid region watersheds. It is hypothesized that different types of co-registered, remotely sensed data including digital elevation data sets (DEDS), multispectral scanner (TM, SPOT), and thermal infrared multispectral scanner (TIMS) can be used in conjunction with limited ground truth data to predict values of input parameters for numeric watershed hydrology models and thus to compute watershed hydrologic and sedimentologic characteristics.

  1. Survey of aquatic macroinvertebrates and amphibians at Wupatki National Monument, Arizona, USA: An evaluation of selected factors affecting species richness in ephemeral pools

    USGS Publications Warehouse

    Graham, T.B.

    2002-01-01

    Ephemeral aquatic habitats in Wupatki National Monument vary from naturally formed pools in arroyos over 5000 years old, to constructed catchment basins with ages estimated at 60-1000+ years old, and borrow pits and stock ponds 30-60 years old. The different ages of these pools provide different histories of colonization by amphibians and aquatic invertebrates, especially temporary pool specialists such as spadefoot toads and branchiopod crustaceans. Ten pools of five different origins and ages were surveyed in August and/or September 1997 for aquatic organisms; a total of 13 surveys were conducted. Twenty-two taxa were found, with the number of species in a pool during any survey ranging from one to 10. Species composition of the communities changed from one sampling date to the next within individual pools. Community structure is an amalgam of species with different dispersal mechanisms that are influenced by different pool characteristics. Age appears to have little effect overall, but may have influenced branchiopod presence/absence. Distance to permanent water, frequency of disturbance, and current pool size were correlated with presence/absence of some species.

  2. Last glacial maximum environments in northwestern Patagonia revealed by fossil small mammals

    NASA Astrophysics Data System (ADS)

    Tammone, Mauro N.; Hajduk, Adan; Arias, Pablo; Teta, Pablo; Lacey, Eileen A.; Pardiñas, Ulyses F. J.

    2014-07-01

    Comparisons of historical and modern assemblages of mammals can yield important insights into patterns and processes of environmental change. Here, we present the first analyses of small mammal assemblages present in northern Patagonia during the last glacial maximum (LGM). Using remains obtained from owl pellets excavated from an archeological cave site (Arroyo Corral I, levels VII-V, carbon dates of 22,400-21,530 cal yr BP), we generate estimates of the minimum number of individuals for all species detected; these estimates, in turn are used to determine relative species abundances. Comparisons of these data with similar analyses of small mammal remains obtained from a second archeological site (ACoII, levels IV-V, carbon dates of 10,010-9220 cal yr BP) as well as from modern owl pellets reveal pronounced changes in relative species abundance since the LGM. In particular, Euneomys chinchilloides and Ctenomys sociabilis - the predominant species during the LGM - declined markedly, suggesting a change from open, bare habitat punctuated by patches of wet meadows and shrubs to the more densely vegetated mosaic of ecotone habitats found in this region today. These data provide important new insights into the environmental changes that have occurred in northern Patagonia over the last 20,000 years.

  3. Gas and oil fired package boilers 20,000 - 50,000 lb/hr

    SciTech Connect

    Day, L.K.

    1996-11-01

    Gas and oil fired package boilers rated at 20,000-50,000 lb/hr are discussed. The fleet consists of approximately 75 units, divided into two basic groups: (1) mobile boiler rooms - these consist of van mounted firetube boilers from 100-350 hp, complete with feedwater systems and water treatment equipment; and (2) trailer-mounted boilers - these consist of {open_quotes}O{close_quotes} type watertube boilers from 24,000 - 120,000 lb/hr, specially designed and mounted on highway legal lowboy trailers for mobility. Other products include new and reconditioned skid-mounted package boilers up to 150,000 lb/hr, turnkey {open_quotes}fast track{close_quotes} steam plants, and custom designed mobile or transportable steam plants for sale or lease. One of the earlier introductions into low NOx technology was a new equipment sale to Union Oil in Arroyo Grande, CA in 1983. A 100,000 lb/hr custom designed boiler with side wall NOx ports and low excess air burner to meet 80 ppm on natural gas was supplied. With the enactment of 40ppm low NOx mandates in Southern California in 2987, it was necessary to quickly retrofit the rental fleet and to work closely with boiler and burner manufacturers to meet the new standards.

  4. Microbial source tracking in a coastal California watershed reveals canines as controllable sources of fecal contamination.

    PubMed

    Ervin, Jared S; Van De Werfhorst, Laurie C; Murray, Jill L S; Holden, Patricia A

    2014-08-19

    Elevated levels of fecal indicator bacteria (FIB), including Escherichia coli and enterococci, trigger coastal beach advisories and signal public health risks. Solving FIB pollution in suburban coastal watersheds is challenging, as there are many potential sources. The Arroyo Burro watershed in Santa Barbara, CA is an example, with its popular, but chronically FIB-contaminated beach. To address, a microbial source tracking study was performed. Surface waters were sampled over 2 years, FIB were quantified, and DNA was analyzed for host-associated fecal markers. Surf zone FIB were only elevated when the coastal lagoon was discharging. Among the fecal sources into the lagoon, including upstream human sources and coastal birds, canines were the most important. Canine sources included input via upstream creek water, which decreased after creek-side residences were educated about proper pet waste disposal, and direct inputs to the lagoon and surf zone, where dog waste could have been tidally exchanged with the lagoon. Based on this study, canine waste can be an influential, yet controllable, fecal source to suburban coastal beaches. PMID:25055204

  5. 87Sr/86Sr sourcing of ponderosa pine used in Anasazi great house construction at Chaco Canyon, New Mexico

    USGS Publications Warehouse

    Reynolds, Amanda C.; Betancourt, Julio L.; Quade, Jay; Patchett, P. Jonathan; Dean, Jeffery S.; Stein, John

    2005-01-01

    Previous analysis of 87Sr/86Sr ratios shows that 10th through 12th century Chaco Canyon was provisioned with plant materials that came from more than 75 km away. This includes (1) corn (Zea mays) grown on the eastern flanks of the Chuska Mountains and floodplain of the San Juan River to the west and north, and (2) spruce (Picea sp.) and fir (Abies sp.) beams from the crest of the Chuska and San Mateo Mountains to the west and south. Here, we extend 87Sr/86Sr analysis to ponderosa pine (Pinus ponderosa) prevalent in the architectural timber at three of the Chacoan great houses (Pueblo Bonito, Chetro Ketl, Pueblo del Arroyo). Like the architectural spruce and fir, much of the ponderosa matches the 87Sr/86Sr ratios of living trees in the Chuska Mountains. Many of the architectural ponderosa, however, have similar ratios to living trees in the La Plata and San Juan Mountains to the north and Lobo Mesa/Hosta Butte to the south. There are no systematic patterns in spruce/fir or ponderosa provenance by great house or time, suggesting the use of stockpiles from a few preferred sources. The multiple and distant sources for food and timber, now based on hundreds of isotopic values from modern and archeological samples, confirm conventional wisdom about the geographic scope of the larger Chacoan system. The complexity of this procurement warns against simple generalizations based on just one species, a single class of botanical artifact, or a few isotopic values.

  6. Unravelling past flash flood activity in a forested mountain catchment of the Spanish Central System

    NASA Astrophysics Data System (ADS)

    Ballesteros-Cánovas, Juan A.; Rodríguez-Morata, Clara; Garófano-Gómez, Virginia; Rubiales, Juan M.; Sánchez-Salguero, Raúl; Stoffel, Markus

    2015-10-01

    Flash floods represent one of the most common natural hazards in mountain catchments, and are frequent in Mediterranean environments. As a result of the widespread lack of reliable data on past events, the understanding of their spatio-temporal occurrence and their climatic triggers remains rather limited. Here, we present a dendrogeomorphic reconstruction of past flash flood activity in the Arroyo de los Puentes stream (Sierra de Guadarrama, Spanish Central System). We analyze a total of 287 increment cores from 178 disturbed Scots pine trees (Pinus sylvestris L.) which yielded indications on 212 growth disturbances related to past flash flood impact. In combination with local archives, meteorological data, annual forest management records and highly-resolved terrestrial data (i.e., LiDAR data and aerial imagery), the dendrogeomorphic time series allowed dating 25 flash floods over the last three centuries, with a major event leaving an intense geomorphic footprint throughout the catchment in 1936. The analysis of meteorological records suggests that the rainfall thresholds of flash floods vary with the seasonality of events. Dated flash floods in the 20th century were primarily related with synoptic troughs owing to the arrival of air masses from north and west on the Iberian Peninsula during negative indices of the North Atlantic Oscillation. The results of this study contribute considerably to a better understanding of hazards related with hydrogeomorphic processes in central Spain in general and in the Sierra de Guadarrama National Park in particular.

  7. 1994 Baseline biological studies for the Device Assembly Facility at the Nevada Test Site

    SciTech Connect

    Townsend, Y.E.; Woodward, B.D.; Hunter, R.B.; Greger, P.D.; Saethre, M.B.

    1995-02-01

    This report describes environmental work performed at the Device Assembly Facility (DAF) in 1994 by the Basic Environmental Monitoring and Compliance Program (BECAMP). The DAF is located near the Mojave-Great Basin desert transition zone 27 km north of Mercury. The area immediately around the DAF building complex is a gentle slope cut by 1 to 3 m deep arroyos, and occupied by transitional vegetation. In 1994, construction activities were largely limited to work inside the perimeter fence. The DAF was still in a preoperational mode in 1994, and no nuclear materials were present. The DAF facilities were being occupied so there was water in the sewage settling pond, and the roads and lights were in use. Sampling activities in 1994 represent the first year in the proposed monitoring scheme. The proposed biological monitoring plan gives detailed experimental protocols. Plant, lizard, tortoise, small mammal, and bird surveys were performed in 1994. The authors briefly outline procedures employed in 1994. Studies performed on each taxon are reviewed separately then summarized in a concluding section.

  8. Surface ages and rates of erosion at the Calico Archaeological Site in the Mojave Desert, Southern California

    NASA Astrophysics Data System (ADS)

    Owen, Lewis A.; Davis, Teresa; Caffee, Marc W.; Budinger, Fred; Nash, David

    2011-01-01

    Erosion rates and surface exposure ages were determined at the Calico Archaeological Site in the Calico Hills of the Mojave Desert, California, using 10Be terrestrial cosmogenic nuclides (TCN) methods. The Calico Hills are composed of Miocene lacustrine deposits of the Barstow Formation and fanglomerates/debris flows of the Pleistocene Yermo Deposits. These deposits are highly denuded and dissected by arroyos that have surfaces armored with chert. Surface erosion rates based on cosmogenic 10Be concentrations in stream sediments range from 19 to 39 m/Ma, with an average of 30.5 ± 6.2 m/Ma. Surface boulders have 10Be TCN ages that range from 27 ka to 198 ka, reflecting significant erosion of the Calico Hills. The oldest boulder age (197 ± 20 ka) places a minimum limit on the age of Yermo deposits. Depth profile ages at four locations within the study area have minimum ages that range from 31 to 84 ka and erosion rate-corrected surface exposure ages ranging from 43 to 139 ka. These surface exposure ages support the view that the surfaces in Yermo deposits formed during the Late Pleistocene to latest Middle Pleistocene. This chronology has important implications for interpreting the context of possible artifacts/geofacts at the site that might provide evidence for early human occupation of North America, and for reconstructing paleoenvironment change and landscape evolution in the region.

  9. Beetles that live with ants (Carabidae, Pseudomorphini, Pseudomorpha Kirby, 1825): A revision of the santarita species group

    PubMed Central

    Erwin, Terry L.; Amundson, Lauren M.

    2013-01-01

    Abstract The Western Hemisphere genus Pseudomorpha Kirby 1825 was last revised by Notman in 1925 based on only a few known species (22) and paltry few specimens (73); other authors have added an additional six species represented by 53 additional specimens since 1925. Baehr (1997) assigned three species from Australia to this genus, albeit in a new subgenus, Austropseudomorpha Baehr 1997. A recent study of collections from throughout the Americas (1757 specimens) has revealed numerous new species that can be arrayed across 19 species groups based on a suite of attributes, some used by Notman and others newly discovered. A taxonomic revision of the species contained in one of these species groups, santarita, is provided herein, as well as a distributional synopsis of the remaining 18 species groups. New species described herein are as follows, each with its type locality: Pseudomorpha huachineras p. n., Arroyo El Cocono, Sierra Huachinera, Sonora, México; P. patagonia sp. n., Madera Canyon, Santa Rita Mountains, Arizona; P.penablanca sp. n., Peña Blanca Lake, Arizona; P. pima sp. n., Madera Canyon (lower), Santa Rita Mountains, Arizona; P. santacruz sp. n., Madera Canyon, Santa Rita Mountains, Arizona; and P. santarita sp. n., Santa Rita Ranch, Santa Rita Mountains, Arizona. PMID:24363599

  10. Direct, immunological and molecular techniques for a fasciolosis survey in a rural area of San Luis, Argentina.

    PubMed

    Carnevale, Silvana; Cabrera, Marta Graciela; Cucher, Marcela Alejandra; di Risio, Cecilia Alicia; Malandrini, Jorge Bruno; Kamenetzky, Laura; Alazraqui, Marcio; Etchart, Cristina Beatriz; Pantano, María Laura; Velásquez, Jorge Néstor

    2013-10-01

    Fasciolosis is a zoonosis caused by the trematode Fasciola hepatica, prevalent in cattle, that is actually emerging as a cause of disease in humans. The goal of this work was to describe the characteristics of fasciolosis in arroyo El Juncal region, La Toma, San Luis province, Argentina. In order to get this objective, a transversal, quantitative study was carried out by a fieldwork that allowed the collection of data, human, animal, and environmental samples. The materials were processed by direct, immunological and/or molecular diagnostic techniques. According to the geographical characteristics and in presence of all the definitive and intermediate hosts, reservoirs, and sources of infection, it was possible to describe the persistence of fasciolosis in the area. The prevalence was 11.90 % in humans (by serology), 5.26 % in cattle (by coprological analysis) and 61.76 % in snails (by PCR). The situation that was found for this area indicates that any measure of intervention for the control of this zoonosis should be adopted by multidisciplinary teams. PMID:24431579

  11. Austrian-Hungarian Astronomical Observatories Run by the Society of Jesus at the Time of the 18th Century Venus Transits

    NASA Astrophysics Data System (ADS)

    Posch, Thomas; Aspaas, Per Pippin; Bazso, Akos; Mueller, Isolde

    2013-05-01

    The Venus transit in June 1761 was the first one to be observed on a truly international scale: almost 250 astronomers followed this rare celestial event (e.g. Wulff 2012, p. 115), and at least 130 published successful observations of it (Aspaas 2012, p. 423). The present paper deals with the astronomical observatories built by the Society of Jesus in its eighteenth century "Provincia Austriae", at which the 1761 transit could be observed. Five Jesuit observatories are being presented in this context: three in today's Austria, namely, two in Vienna and one in Graz; one in Trnava in today's Slovakia and one in Cluj in today's Romania. Thereafter, we briefly examine which of these observatories submitted any Venus transit observations for publication in the appendix to Maximilian Hell's "Ephemerides astronomicae ad meridianum Vindobonensem" for the year 1762.

  12. The Observatory-Camping: a place of posible apprenticeship to the education and popularization of the Astronomy

    NASA Astrophysics Data System (ADS)

    Navone, H. D.; Gastaud, C.; Pattini, N.; Aquilano, R.

    The development of Astronomy in the Educations area presents limitations as: poor equipment, trouble in managing space and time, difficulty to make experiences. The sky contaminations in the city, because of the luminosity, make the astronomical observation just impossible. But, the formal education has a wonderful media for the Astronomy: camping; this activity is very close to physical education. The proposal is the transformation of camping in "observatory-camping", to introduce astronomical concepts by the exploration of the sky. The methodology for this job is the observation of the sky by the eyes, first, and then making use of binoculars and a telescope, far from urban centres. Finally, this experience has place in the Planta de Campamentos N° 7502 (Máximo Paz, Santa Fe), which belongs to Ministerio de Educación de la Provincia de Santa Fe. FULL TEXT IN SPANISH

  13. Redescription of Gyropus parvus (Ewing, 1924) (Insecta: Phthiraptera: Amblycera: Gyropidae) from tucos-tucos (Rodentia: Ctenomyidae: Ctenomys ) in Patagonia, Argentina.

    PubMed

    Martino, N S; Romero, M D; Castro, D C

    2010-02-01

    A detailed redescription of Gyropus parvus (Insecta: Phthiraptera: Amblycera: Gyropidae) is given based on specimens collected from the type host, Ctenomys colburni Allen 1903 , and the type locality, Estancia Huanuluán, Provincia de Rio Negro, Argentina. We expand and provide new chaetotaxy. New scanning electron microscopy images showing microstructural details of adults and eggs of G. parvus obtained from topotype specimens are included. Sexual dimorphism was mainly shown by differences in body size and abdominal chaetotaxy, with females being 17.5% larger than males and with more setae in each cluster. Significant differences between males and females were also observed in sternal plate measurements. Features described here show homogeneity within type host population. This information contributes to our knowledge of intra- and inter-specific variability for parasite populations. Our investigation constitutes the first collection of G. parvus from the type host and locality since it was described. PMID:19747015

  14. Critical Dynamics in Quenched 2D Atomic Gases

    NASA Astrophysics Data System (ADS)

    Larcher, F.; Dalfovo, F.; Proukakis, N. P.

    2016-05-01

    Non-equilibrium dynamics across phase transitions is a subject of intense investigations in diverse physical systems. One of the key issues concerns the validity of the Kibble-Zurek (KZ) scaling law for spontaneous defect creation. The KZ mechanism has been recently studied in cold atoms experiments. Interesting open questions arise in the case of 2D systems, due to the distinct nature of the Berezinskii-Kosterlitz-Thouless (BKT) transition. Our studies rely on the stochastic Gross-Pitaevskii equation. We perform systematic numerical simulations of the spontaneous emergence and subsequent dynamics of vortices in a uniform 2D Bose gas, which is quenched across the BKT phase transition in a controlled manner, focusing on dynamical scaling and KZ-type effects. By varying the transverse confinement, we also look at the extent to which such features can be seen in current experiments. Financial support from EPSRC and Provincia Autonoma di Trento.

  15. Chapman Conference on Sediment Transport Processes in Estuaries

    NASA Astrophysics Data System (ADS)

    Perillo, Gerardo M. E.; Lavelle, J. William

    During the week of June 13-17, 1988, 72 sediment transport researchers “aggregated” at the Universidad Nacional del Sur in Bahfa Blanca, Argentina, to participate in an AGU Chapman Conference on Sediment Transport Processes in Estuaries. The main goals of the meeting were to discuss recent advances in estuarine science, to appraise promising future research directions, and to develop contacts and establish working relationships between Latin American and non-Latin- American estuarine researchers. The meeting drew participants from Argentina, Brazil, Chile, Uruguay, Venezuela, the U.S., Canada, Britain, France, the Federal Republic of Germany, The Netherlands, and South Africa. Meeting cosponsors were UNESCO, Secretaria de Ciencía y Técnica, Consejo Nacional de Investigaciones Cientificas y Técnicas, Comision de Investigaciones Cientificas de la Provincia de Buenos Aires, Universidad del Sur, Municipalidad de Bahia Blanca, Asociaciôn Argentina de Geofisicos y Geodestas (AGU sister organization), and the Instituto Argentino de Oceanografia (IADO).

  16. Rock magnetic characteristics of faulted sediments with magnetic anomalies: A case study from the Albuquerque Basin, Rio Grande Rift, New Mexico (Invited)

    NASA Astrophysics Data System (ADS)

    Hudson, M. R.; Grauch, V. J.

    2009-12-01

    High-resolution airborne surveys in the Rio Grande rift have documented abundant short-wavelength, low-amplitude magnetic anomalies generated at faults within basin sediments. We present a rock magnetic study bearing on the source of a10-20-nT linear anomaly over the San Ysidro normal fault, which is well exposed in outcrop in the northern part of the Albuquerque Basin. Magnetic susceptibility (MS) values (SI vol) from 310 sites distributed through a 1200-m-thick composite section of rift-filling sediments of Santa Fe Group and pre-rift sedimentary rocks juxtaposed by the San Ysidro fault have lognormal distributions with well-defined means. These averages generally increase up section through eight map units: from 1.7E-4 to 2.2E-4 in the pre-rift Cretaceous and Eocene rocks, from 9.9E-4 to 1.2E-3 in three units of the Miocene Zia and Cerro Conejo Formations of the Santa Fe Group, and from 1.5E-3 to 3.5E-3 in three units of the Miocene-Pliocene Arroyo Ojito and Ceja Formations of the Santa Fe Group. Remanent magnetization is not important; Koenigsberger ratios are less than 0.3 for Santa Fe Group samples. Rock magnetic parameters (e.g., ARM/MS and S ratios) and petrography indicate that detrital magnetite content and its variable oxidation to maghemite and hematite are the predominant controls of magnetic property variations within the Santa Fe Group sediments. Magnetite is present in rounded detrital grains (including both homogeneous and subdivided types) and as fine inclusions in volcanic rock fragments. Santa Fe Group sediments with highest magnetic susceptibility have greatest magnetic-grain size as indicated by lowest ARM/MS ratios. Magnetic susceptibility increases progressively with sediment grain size to pebbly sand within the fluvial Arroyo Ojito Formation. In contrast, MS reaches highest values in fine to medium sands in eolian Zia Formation. Partial oxidation of detrital magnetite and resultant lower MS is spatially associated with calcite cementation

  17. Assessment of Longitudinal Variability in Channel Geometry and Bed Gradient Over an 81-km Reach of the Rio Puerco, New Mexico

    NASA Astrophysics Data System (ADS)

    Griffin, E. R.; Vincent, K. R.; Friedman, J. M.; Kean, J. W.

    2002-12-01

    Beginning in the 1880's, the Rio Puerco, New Mexico incised an arroyo more than 300 km long, 10 m deep, and 200 m wide. Downstream sections of the arroyo have been aggrading since the 1930s, but the relative influences of climatic fluctuations, exotic species invasion, and land management are unclear. As part of an effort to model flow and sediment transport for the lower 81 kilometers (50 miles) of the Rio Puerco, we measured the longitudinal profile and channel cross-sections, and we derived channel information from a sequence of large-scale aerial photographs. Large-scale (1:5,000) aerial photographs of the 81-km reach were merged in a GIS dataset, and channel top width and radius of curvature were determined for a dense set of points along the channel centerline. Average bankfull width in bends is only slightly greater than the average width in straight reaches, and the variability in width is also slightly greater in bends. Changes in reach-averaged channel top width in relatively straight reaches were found to be related to specific geomorphic features affecting bed gradient, including a recent bend cutoff and the mouth of a major tributary. The observed changes in width lead to subdivision of the river into four internally consistent reaches. A longitudinal thalweg profile was measured using a differential GPS to survey points every 40 m along the entire 81-km reach. About 2,000 points were measured with vertical and horizontal accuracy within 3 cm. Forty-nine channel cross-sections were also surveyed in both bends and straight reaches, distributed over the length of the system. Frequency relations for channel widths measured from photographs and in the field indicate the field measurements constitute a representative sample of the channel. Photographic widths can be used to predict reach-averaged channel geometry after removing a small bias in width determined from the photographs. High water marks (silt lines) for three recent flows were traced the entire

  18. Environmental contaminants and biomarker responses in fish from the Rio Grande and its U.S. tributaries: spatial and temporal trends.

    PubMed

    Schmitt, Christopher J; Hinck, Jo Ellen; Blazer, Vicki S; Denslow, Nancy D; Dethloff, Gail M; Bartish, Timothy M; Coyle, James J; Tillitt, Donald E

    2005-11-01

    We collected, examined, and analyzed 368 fish of seven species from 10 sites on rivers of the Rio Grande Basin (RGB) during late 1997 and early 1998 to document temporal and geographic trends in the concentrations of accumulative contaminants and to assess contaminant effects on the fish. Sites were located on the mainstem of the Rio Grande and on the Arroyo Colorado and Pecos River in Texas (TX), New Mexico (NM), and Colorado. Common carp (Cyprinus carpio) and largemouth bass (Micropterus salmoides) were the targeted species. Fish were examined in the field for internal and external visible gross lesions, selected organs were weighed to compute ponderal and organosomatic indices, and samples of tissues and fluids were obtained and preserved for analysis of fish health and reproductive biomarkers. Whole fish from each station were composited by species and gender and analyzed for organochlorine chemical residues and elemental contaminants using instrumental methods, and for 2,3,7,8-tetrachloro dibenzo-p-dioxin-like activity (TCDD-EQ) using the H4IIE rat hepatoma cell bioassay. Overall, fish from lower RGB stations contained greater concentrations of organochlorine pesticide residues and appeared to be less healthy than those from sites in the central and upper parts of the basin, as indicated by a general gradient of residue concentrations and biomarker responses. A minimal number of altered biomarkers and few or no elevated contaminant concentrations were noted in fish from the upper RGB. The exception was elevated concentrations [up to 0.46 microg/g wet-weight (ww)] of total mercury (Hg) in predatory species from the Rio Grande at Elephant Butte Reservoir, NM, a condition documented in previous studies. Arsenic (As) and selenium (Se) concentrations were greatest in fish from sites in the central RGB; Se concentrations in fish from the Pecos River at Red Bluff Lake, TX and from the Rio Grande at Langtry, TX and Amistad International Reservoir, TX exceeded

  19. Environmental contaminants and biomarker responses in fish from the Rio Grande and its U.S. tributaries: Spatial and temporal trends

    USGS Publications Warehouse

    Schmitt, C.J.; Hinck, J.E.; Blazer, V.S.; Denslow, N.D.; Dethloff, G.M.; Bartish, T.M.; Coyle, J.J.; Tillitt, D.E.

    2005-01-01

    We collected, examined, and analyzed 368 fish of seven species from 10 sites on rivers of the Rio Grande Basin (RGB) during late 1997 and early 1998 to document temporal and geographic trends in the concentrations of accumulative contaminants and to assess contaminant effects on the fish. Sites were located on the mainstem of the Rio Grande and on the Arroyo Colorado and Pecos River in Texas (TX), New Mexico (NM), and Colorado. Common carp (Cyprinus carpio) and largemouth bass (Micropterus salmoides) were the targeted species. Fish were examined in the field for internal and external visible gross lesions, selected organs were weighed to compute ponderal and organosomatic indices, and samples of tissues and fluids were obtained and preserved for analysis of fish health and reproductive biomarkers. Whole fish from each station were composited by species and gender and analyzed for organochlorine chemical residues and elemental contaminants using instrumental methods, and for 2,3,7,8-tetrachloro dibenzo-p-dioxin-like activity (TCDD-EQ) using the H4IIE rat hepatoma cell bioassay. Overall, fish from lower RGB stations contained greater concentrations of organochlorine pesticide residues and appeared to be less healthy than those from sites in the central and upper parts of the basin, as indicated by a general gradient of residue concentrations and biomarker responses. A minimal number of altered biomarkers and few or no elevated contaminant concentrations were noted in fish from the upper RGB. The exception was elevated concentrations [up to 0.46 ??g/g wet-weight (ww)] of total mercury (Hg) in predatory species from the Rio Grande at Elephant Butte Reservoir, NM, a condition documented in previous studies. Arsenic (As) and selenium (Se) concentrations were greatest in fish from sites in the central RGB; Se concentrations in fish from the Pecos River at Red Bluff Lake, TX and from the Rio Grande at Langtry, TX and Amistad International Reservoir, TX exceeded published

  20. Effects of Varying Shrub Density on Erosion and Deposition During a Large Flood, Rio Puerco, New Mexico

    NASA Astrophysics Data System (ADS)

    Griffin, E. R.; Friedman, J. M.; Vincent, K. R.

    2010-12-01

    A large flood in August 2006 following saltcedar control efforts along a 12-km segment of the Rio Puerco provided an opportunity to measure the effects of varying shrub density on down-valley flood flow and sediment transport. Post-flood field observations in two 3-km long arroyo segments, one in the sprayed reach and one downstream from the sprayed reach, indicate the density and distribution of woody vegetation had a substantial effect on locations and magnitudes of sediment erosion and deposition. In the reach sprayed with herbicide three years before the flood, in which dense woody stems covered only about 30% of the pre-flood (2005) floodplain, average channel width increased by 63% during the flood. Downstream from the sprayed reach, where both pre-and post-flood shrubs covered 50% of the floodplain, erosion was limited to sites where flood flow through sharp bends undercut the arroyo wall. Flow and suspended sediment transport were computed for two 500-m-long floodplain segments, one in the sprayed reach and one downstream from the sprayed reach. Large volumes of fine-grain sediment (fine to very fine sand and silt) were available for transport during the flood in both reaches. In the reach sprayed with herbicide, dense canopy (dominantly saltcedar; Tamarix spp.) remained only within 10-m-wide linear bands oriented along the present or former channel and in isolated, small shrubs scattered about the floodplain. Downstream from the sprayed reach, adjacent shrub bands were closely spaced, with canopies touching in many areas. Mature saltcedar along the Rio Puerco have rigid, dense stems more than 2 m high, whereas floodplain flow depths during the August 2006 event were on the order of 1 m. Drag on the stems was computed using the average stem density (average stem diameter divided by average stem spacing squared) determined from a large number of measurements along the Rio Puerco, 0.35 m-1 (Friedman and others, unpublished data, 2004). Computations of flow

  1. Analysis of Dissolved Selenium Loading from Surface Water and Groundwater to Sweitzer Lake, Colorado, 2006-07

    USGS Publications Warehouse

    Thomas, Judith C.

    2009-01-01

    Elevated selenium concentrations in streams are a water-quality concern in western Colorado. Sweitzer Lake was placed on the State 303(d) list as impaired with respect to dissolved selenium. In Colorado, the Water Quality Control Division of the Colorado Department of Public Health and Environment is required to develop total maximum daily loads of selenium for the 303(d) list segments. The U.S. Geological survey, in cooperation with the Colorado Department of Public Health and Environment, summarized selenium loading from surface water and ground water to Sweitzer Lake to support the total maximum daily loads development process. Surface-water and groundwater data were collected to quantify selenium concentrations and loads to Sweitzer Lake from October 2006 to October 2007. These data were used to determine the amount of selenium load (pounds annually) that would need to be reduced for the contributing sources (surface water and groundwater) to meet the State chronic aquatic-life standard of 4.6 micrograms per liter for dissolved selenium, herein referred to as 'a load reduction.' Selenium concentration data were also compared to the State acute aquatic-life standard of 18.4 micrograms per liter for dissolved selenium. Both surface-water and groundwater-quality samples collected during this study were found to exceed the chronic standard. Surface-water quantity and quality data were collected at Garnet Canal Diversion and Diversion Drain. Groundwater flux data were collected at 10 seepage-meter sires in Sweitzer Lake, and groundwater-quality data were collected at a groundwater seep and inferred from a January 2007 sample collected at Garnet Canal Diversion. Selenium concentrations and loads were greater at Garnet Canal Diversion than those observed at Diversion Drain. Approximately one-third of Garnet Canal Diversion-s Streamflow originates from Loutzenhizer Arroyo. Selenium concentrations observed during previous studies at Loutzenhizer Arroyo indicate high

  2. Urban development under extreme hydrologic and weather conditions for El Paso-Juarez: Recommendations resulting from hydrologic modeling, GIS, and remote sensing analyses

    NASA Astrophysics Data System (ADS)

    Barud-Zubillaga, Alberto

    During the 2006 El Paso-Juarez flood there were many concerns regarding the capability of the existing stormwater system to handle 50- and 100-year flood events in El Paso, Texas and Juarez, Mexico area. Moreover in 2008, a considerable wet year from the normal 223 mm of annual precipitation for El Paso demonstrated that the area could very well received large amounts of precipitation at localized areas in short periods of time, representing a great flood threat to residents living in areas prone to flood. Some climate change projections for the area are exactly what had occurred over the last two decades; an increased number of torrential rainstorms over smaller concentrated pieces of land separated by longer years of drought between rainstorms. This study consisted in three projects focused on three critical regions within the El Paso-Juarez area that were greatly affected by the 2006 Flood. The goal was to identify if natural arroyos or the existent built stormwater system, could properly managed the projected precipitation patterns. The three projects described in this dissertation touch on the following points: (a) the importance of a reliable precipitation model that could accurately describes precipitation patterns in the region under extreme drought and wet climates conditions; (b) differences in land use/land cover characteristics as factors promoting or disrupting the possibility for flooding, and (c) limitations and capabilities of existent stormwater systems and natural arroyos as means to control flooding. Conclusions and recommendations are shown below, which apply not only to each particular project, but also to all study areas and similar areas in the El Paso-Juarez region. Urbanization can improve or worsen a pre-existing natural stormwater system if built under its required capacity. Such capacity should be calculated considering extreme weather conditions, based on a denser network of precipitation stations to capture the various microclimates

  3. The role of fluvial geomorphic analysis and historical ecology in support of flood control channel management in the Livermore Valley, California

    NASA Astrophysics Data System (ADS)

    Beagle, J. R.; Pearce, S.; Stanford, B.; McKee, L. J.; Grossinger, R. M.

    2011-12-01

    Julie Beagle, Sarah Pearce, Bronwen Stanford, Lester McKee, Robin Grossinger Flood control, city, and county managers are under increasing pressure to include improved habitat and water quality function, in addition to normal flood control function, to operating procedures for flood channels. Obtaining permits for routine maintenance, such as sediment removal, is now more challenging unless management agencies can demonstrate high level understanding of modern channel processes in the context of historical ecosystem functions. To address this issue, San Francisco Estuary Institute has been working with local agencies throughout the Bay Area to measure and understand sediment supply, the causes and rates of sedimentation in facilities, the impacts of maintenance activities to habitat and species of interest, and to identify mitigation opportunities within the context of historical watershed functions. Ongoing research in the Alameda Creek watershed provides an example of the intersection between historical ecology and modern geomorphic analysis as a developed approach for informing local resource management decisions. Zone 7 Water Agency, in the northern area of the Alameda Creek watershed, maintains 37 miles of channels that receive and convey urban drainage from Livermore, Dublin, and Pleasanton, California; and runoff and eroded sediment from the watersheds of Arroyo Mocho, Arroyo Las Positas and tributaries to the north (~220 sq mi). In the last three decades, population has doubled, accompanied by changing land uses in Livermore Valley. As a result, the flow of sediment and water has evolved such that, in some reaches, a combination of loss of capacity from sedimentation coupled with increased peak flows has led to channels that may not pass design flows. Previous sediment budget work by SFEI showed that the majority of sediment supply to the Alameda Flood Control Channel on the San Francisco Bay margin is supplied from the northern tributaries. SFEI's wider

  4. Geologic investigation :an update of subsurface geology on Kirtland Air Force Base, New Mexico.

    SciTech Connect

    Van Hart, Dirk

    2003-06-01

    The objective of this investigation was to generate a revised geologic model of Kirtland Air Force Base (KAFB) incorporating the geological and geophysical data produced since the Site-Wide Hydrogeologic Characterization Project (SWHC) of 1994 and 1995. Although this report has certain stand-alone characteristics, it is intended to complement the previous work and to serve as a status report as of late 2002. In the eastern portion of KAFB (Lurance Canyon and the Hubbell bench), of primary interest is the elevation to which bedrock is buried under a thin cap of alluvium. Elevation maps of the bedrock top reveal the paleodrainage that allows for the interpretation of the area's erosional history. The western portion of KAFB consists of the eastern part of the Albuquerque basin where bedrock is deeply buried under Santa Fe Group alluvium. In this area, the configuration of the down-to-the-west, basin-bounding Sandia and West Sandia faults is of primary interest. New geological and geophysical data and the reinterpretation of old data help to redefine the location and magnitude of these elements. Additional interests in this area are the internal stratigraphy and structure of the Santa Fe Group. Recent data collected from new monitoring wells in the area have led to a geologic characterization of the perched Tijeras Arroyo Groundwater system and have refined the known limits of the Ancestral Rio Grande fluvial sediments within the Santa Fe Group. Both the reinterpretation of the existing data and a review of the regional geology have shown that a segment of the boundary between the eastern and western portions of KAFB is a complicated early Tertiary (Laramide) wrench-fault system, the Tijeras/Explosive Ordnance Disposal Area/Hubbell Spring system. A portion of this fault zone is occupied by a coeval ''pull-apart'' basin filled with early Tertiary conglomerates, whose exposures form the ''Travertine Hills''.

  5. Comprehensive Representation of Hydrologic and Geomorphic Process Coupling in Numerical Models: Internal Dynamics and Basin Evolution

    NASA Astrophysics Data System (ADS)

    Istanbulluoglu, E.; Vivoni, E. R.; Ivanov, V. Y.; Bras, R. L.

    2005-12-01

    Landscape morphology has an important control on the spatial and temporal organization of basin hydrologic response to climate forcing, affecting soil moisture redistribution as well as vegetation function. On the other hand, erosion, driven by hydrology and modulated by vegetation, produces landforms over geologic time scales that reflect characteristic signatures of the dominant land forming process. Responding to extreme climate events or anthropogenic disturbances of the land surface, infrequent but rapid forms of erosion (e.g., arroyo development, landsliding) can modify topography such that basin hydrology is significantly influenced. Despite significant advances in both hydrologic and geomorphic modeling over the past two decades, the dynamic interactions between basin hydrology, geomorphology and terrestrial ecology are not adequately captured in current model frameworks. In order to investigate hydrologic-geomorphic-ecologic interactions at the basin scale we present initial efforts in integrating the CHILD landscape evolution model (Tucker et al. 2001) with the tRIBS hydrology model (Ivanov et al. 2004), both developed in a common software environment. In this talk, we present preliminary results of the numerical modeling of the coupled evolution of basin hydro-geomorphic response and resulting landscape morphology in two sets of examples. First, we discuss the long-term evolution of both the hydrologic response and the resulting basin morphology from an initially uplifted plateau. In the second set of modeling experiments, we implement changes in climate and land-use to an existing topography and compare basin hydrologic response to the model results when landscape form is fixed (e.g. no coupling between hydrology and geomorphology). Model results stress the importance of internal basin dynamics, including runoff generation mechanisms and hydrologic states, in shaping hydrologic response as well as the importance of employing comprehensive

  6. Real-time Polymerase Chain Reaction Analysis of Sewage Samples to Determine Oral Polio Vaccine Circulation Duration and Mutation After Mexican National Immunization Weeks

    PubMed Central

    Troy, Stephanie B.; Ferreyra-Reyes, Leticia; Canizales-Quintero, Sergio; Huang, ChunHong; Lee, Yu-Jin; Báez-Saldaña, Renata; Ferreira-Guerrero, Elizabeth; García-García, Lourdes; Maldonado, Yvonne

    2012-01-01

    Background. Oral polio vaccine (OPV) can mutate and cause outbreaks of paralytic poliomyelitis with prolonged replication. After poliovirus eradication, global use of inactivated polio vaccine (IPV) may be needed until all OPV stops circulating. Mexico, where children receive routine IPV but where OPV is given only during biannual national immunization weeks (NIWs), provides a natural setting to study duration of OPV circulation in a community primarily vaccinated with IPV. Methods. One-liter sewage samples from four separate arroyos (creeks) near Orizaba, Mexico, were collected monthly for 12 months. Concentrated sewage underwent RNA extraction, reverse transcription, and real-time polymerase chain reaction (PCR) to detect OPV serotypes 1, 2, and 3 and their variants containing the serotype-specific point mutation in the 5′ untranslated region associated with neurovirulence. Results. OPV was detected 3, 4, 5, and 7 months after the May 2010 NIW, but was not detected at 6 or 8 months. A second and third NIW occurred in February 2011 and May 2011, and OPV was detected in the sewage monthly after both of these NIW through July 2011 when collection stopped. The OPV detected was primarily serotype 2 and predominantly contained the point mutations in the 5′ untranslated region associated with increased neurovirulence. Conclusions. OPV was detected in sewage as late as 7 months after an NIW in a Mexican community primarily vaccinated with IPV, but was not detected at 8 months, suggesting that OPV circulation may have ceased. These data suggest that in communities with high vaccination rates, 1 or 2 years of IPV administration after OPV cessation could be sufficient to prevent outbreaks of paralytic poliomyelitis from vaccine-derived strains. PMID:23667738

  7. The effects of wildfire on the sediment yield of a coastal California watershed

    USGS Publications Warehouse

    Warrick, J.A.; Hatten, J.A.; Pasternack, G.B.; Gray, A.B.; Goni, M.A.; Wheatcroft, R.A.

    2012-01-01

    The occurrence of two wildfires separated by 31 yr in the chaparral-dominated Arroyo Seco watershed (293 km) of California provides a unique opportunity to evaluate the effects of wildfire on suspended-sediment yield. Here, we compile discharge and suspended-sediment sampling data from before and after the fires and show that the effects of the postfire responses differed markedly. The 1977 Marble Cone wildfire was followed by an exceptionally wet winter, which resulted in concentrations and fluxes of both fine and coarse suspended sediment that were ˜35 times greater than average (sediment yield during the 1978 water year was 11,000 t/km2/yr). We suggest that the combined 1977–1978 fire and flood had a recurrence interval of greater than 1000 yr. In contrast, the 2008 Basin Complex wildfire was followed by a drier than normal year, and although suspended-sediment fluxes and concentrations were significantly elevated compared to those expected for unburned conditions, the sediment yield during the 2009 water year was less than 1% of the post–Marble Cone wildfire yield. After the first postfire winters, sediment concentrations and yield decreased with time toward prefire relationships and continued to have significant rainfall dependence. We hypothesize that the differences in sediment yield were related to precipitation-enhanced hillslope erosion processes, such as rilling and mass movements. The millennial-scale effects of wildfire on sediment yield were explored further using Monte Carlo simulations, and these analyses suggest that infrequent wildfires followed by floods increase long-term suspended-sediment fluxes markedly. Thus, we suggest that the current approach of estimating sediment yield from sediment rating curves and discharge data—without including periodic perturbations from wildfires—may grossly underestimate actual sediment yields.

  8. Testing the effects of an introduced palm on a riparian invertebrate community in southern California.

    PubMed

    Talley, Theresa Sinicrope; Nguyen, Kim-Chi; Nguyen, Anthony

    2012-01-01

    Despite the iconic association of palms with semi-arid regions, most are introduced and can invade natural areas. Along the San Diego River (San Diego, California, USA), the introduced Canary Island date palm (Phoenix canariensis) forms dense patches among native riparian shrubs like arroyo willow (Salix lasiolepis). The structural differences between the palm and native shrubs are visually obvious, but little is known about palm's effects on the ecosystem. We tested for the effects of the palm on a riparian invertebrate community in June 2011 by comparing the faunal and environmental variables associated with palm and willow canopies, trunks and ground beneath each species. The palm invertebrate community had lower abundance and diversity, fewer taxa feeding on the host (e.g., specialized hemipterans), and more taxa likely using only the plant's physical structure (e.g., web-builders, oak moths, willow hemipterans). There were no observed effects on the ground-dwelling fauna. Faunal differences were due to the physical and trophic changes associated with palm presence, namely increased canopy density, unpalatable leaves, trunk rugosity, and litter accumulations. Palm presence and resulting community shifts may have further ecosystem-level effects through alteration of physical properties, food, and structural resources. These results were consistent with a recent study of invasive palm effects on desert spring arthropods, illustrating that effects may be relatively generalizable. Since spread of the palm is largely localized, but effects are dramatic where it does occur, we recommend combining our results with several further investigations in order to prioritize management decisions. PMID:22879991

  9. The International Congress of Mechanical Engineering and Agricultural Sciences - CIIMCA 2013

    NASA Astrophysics Data System (ADS)

    Remolina-Millán, Aduljay; Hernández-Arroyo, Emil

    2014-06-01

    The organizing committee of The International Congress of Mechanical Engineering and Agricultural Sciences - CIIMCA 2013 - are pleased to present CIIMCA-2013: the first international conference focused on subjects of materials science, mechanical engineering and renewable energy organized by Mechanical Engineering Faculty of the ''Universidad Pontificia Bolivariana'' in Bucaramanga, Colombia. This conference aims to be a place to produce discussions on whole topics of the congress, between the scientists of Colombia and the world. We strongly believe that knowledge is fundamental to the development of our countries. For that reason this multidisciplinary conference is looking forward to integrate engineering, agricultural science and nanoscience and nanotechnology to produce a synergy of this area of knowledge and to achieve scientific and technological developments. Agriculture is a very important topic for our conference; in Colombia, agricultural science needs more attention from the scientific community and the government. In the Faculty of Mechanical Engineering we are beginning to work on these issues to produce knowledge and improve the conditions in our country. The CIIMCA conference is a great opportunity to create interpersonal relationships and networks between scientists around the world. The interaction between scientists is very important in the process of the construction of knowledge. The general chairman encourages and invites you to make friends, relationships and participate strongly in the symposia and all program activities. PhD Aduljay Remolina-Millán Principal Chairman, International Mechanical Engineering and Agricultural Sciences Congress - CIIMCA Msc Emil Hernández-Arroyo Principal Chairman, International Mechanical Engineering and Agricultural Sciences Congress - CIIMCA Conference photograph Conference photograph 'Universidad Pontificia Bolivariana seccional Bucaramanga' host of the first International Mechanical Engineering and

  10. Adaptation of microalgae to a gradient of continuous petroleum contamination.

    PubMed

    Carrera-Martinez, Daniel; Mateos-Sanz, Aranzazu; Lopez-Rodas, Victoria; Costas, Eduardo

    2011-01-25

    In order to study adaptation of microalgae to petroleum contamination, we have examined an environmental stress gradient by crude oil contamination in the Arroyo Minero River (AMR), Argentina. Underground crude oil has constantly leaked out since 1915 as a consequence of test drilling for possible petroleum exploitation. Numerous microalgae species proliferated in AMR upstream of the crude oil spill. In contrast, only four microalgal species were detected in the crude oil spill area. Species richness increases again downstream. Microalgae biomass in the crude oil spill area is dominated by a mesophile species, Scenedesmus sp. Effects of oil samples from AMR spill on photosynthetic performance and growth were studied using laboratory cultures of two Scenedesmus sp. strains. One strain (Se-co) was isolated from the crude oil spill area. The other strain (Se-pr) was isolated from a pristine area without petroleum contamination. Crude oil has undetectable effects on Se-co strain. In contrast crude oil rapidly destroys Se-pr strain. However, Se-pr strain can adapt to low doses of petroleum (≤ 3% v/v total hydrocarbons/water) by means of physiological acclimatization. In contrast, only rare crude oil-resistant mutants are able to grow under high levels of crude oil (≥ 10% v/v total hydrocarbons/water). These crude oil-resistant mutants have arisen through rare spontaneous mutations that occur prior to crude oil exposure. Species richness in different areas of AMR is closely connected to the kind of mechanism (genetic adaptation vs. physiological acclimatization) that allows adaptation. Resistant-mutants are enough to assure the survival of microalgal species under catastrophic crude oil spill. PMID:21216344

  11. Modern sedimentation patterns in Laguna de Medina, Southern Spain, derived from lake surface and soil samples

    NASA Astrophysics Data System (ADS)

    van ´t Hoff, Jasmijn; Schröder, Tabea; Reicherter, Klaus; Held, Peter; Melles, Martin

    2016-04-01

    In September 2014 and March 2015, a 25.66 m long sediment core (Co1313) was retrieved from the centre of Laguna de Medina, a small endorheic salt lake in Cádiz, SW Spain. This record covers the last 9.000 years, thus providing an unique archive for Holocene climatic and environmental changes with extraordinary high temporal resolution. For a better understanding of the palaeoenvironmental proxies to be analysed on the sediment core, the modern processes of sediment formation in the lake and its catchment under known environmental conditions were investigated on a set of 46 lake sediment surface samples and 32 soil surface sediment samples from the lake and the close surroundings, respectively. These samples were analysed for bulk mineralogy (XRD), chemical composition (XRF), grain-size distribution (laser scanner), and carbonate, total organic carbon (TOC), nitrogen (TN) and sulphur (TS) contents (elemental analyser). Based on the mineralogical, geochemical and granulometrical data, the lake can be divided into four zones. The northern shore is characterized by particularly high quartz contents and coarse grain sizes. This reflects input from ancient terraces of the Guadalete River that are exposed in that area. The southern shore is characterised by high calcite contents due to sediment supply from the Cretaceous ´Capas rojaś, a series of Subbetic deep-water marl- and limestones. The southeastern and to a lesser extend the northwestern shores show particularly high dolomite contents, reflecting the Triassic dolomites outcroping in the southeastern catchment. The southeastern shore furthermore is also influenced by strong terrestrial input of the Triassic Keuper facies from the most important inlet, Arroyo Fuente Bermeja, as reflected by high contents of Ti, K, Al, Fe, Rb in the lake sediments. The last zone comprises only a small part of the western shore and is characterized by a relatively high gypsum amount. This does not reflect the geology in the catchment

  12. Marked spatial gradient in the topographic evolution of the Andes spanning the Chilean flat-slab transition: evidence from stable isotope paleoaltimetry and zircon double dating

    NASA Astrophysics Data System (ADS)

    Hoke, G. D.; McPhillips, D. F.; Giambiagi, L.; Garzione, C. N.; Mahoney, J. B.; Strecker, M. R.

    2015-12-01

    The major changes in the subduction angle of the Nazca plate are often hypothesized to have important consequences for the tectonic evolution of the Andes. Temporal and spatial patterns of topographic growth and exhumation are indicators that should help elucidate any linkages to subduction angle. Here, we combine observations from stable isotope paleoaltimetry with detrital zircon double dating between 30 and 35°S to demonstrate a consistent increase in surface and rock uplift in the Andes south of 32°S. The stable isotope data are from Miocene pedogenic carbonates collected from seven different basin sequences spanning different tectonic and topographic positions in the range. Paleoelevations between 1 km and 1.9 km are calculated using modern local isotope-elevation gradients along with carbonate-formation temperatures determined from clumped isotope studies in modern soils. Present day, low elevation foreland localities were at their present elevations during the Miocene, while three of the intermontane basins experienced up to 2 km of surface uplift between the end of deposition during the late Miocene and present. Detrital zircon (U-Th-Sm)/He and U-Pb double dating in three modern drainage basins (Tunuyán, Arroyo Grande and Río de los Patos) reveals clear Miocene exhumation signals south of the flat slab with no recent exhumation apparent at 32°S. The exhumation pattern is consistent with paleoaltimetry results. Interestingly, the maximum inferred surface uplift is greatest where the crust is thinnest, and the timing of the observed changes in elevation and exhumation has not been linked to any documented episodes of large-magnitude crustal shortening in the eastern half of the range. The spatial pattern of surface uplift and exhumation seems to mimic the Pampean flat slab's geometry, however, it could be equally well explained by eastward migration of a crustal root via ductile deformation in the lower crust and is not related to flat-slab subduction.

  13. UMTRA project water sampling and analysis plan, Mexican Hat, Utah

    SciTech Connect

    Not Available

    1994-04-01

    The Mexican Hat, Utah, Uranium Mill Tailings Remedial Action (UMTRA) Project site is a former uranium mill that is undergoing surface remediation in the form of on-site tailings stabilization. Contaminated surface materials from the Monument Valley, Arizona, UMTRA Project site have been transported to the Mexican Hat site and are being consolidated with the Mexican Hat tailings. The scheduled completion of the tailings disposal cell is August 1995. Water is found in two geologic units at the site: the Halgaito Shale Formation and the Honaker Trail Formation. The tailings rest on the Halgaito Shale, and water contained in that unit is a result of milling activities and, to a lesser extent, water released from the tailings from compaction during remedial action construction of the disposal cell. Water in the Halgaito Shale flows through fractures and discharges at seeps along nearby arroyos. Flow from the seeps will diminish as water drains from the unit. Ground water in the lower unit, the Honaker Trail Formation, is protected from contamination by an upward hydraulic gradient. There are no nearby water supply wells because of widespread poor background ground water quality and quantity, and the San Juan River shows no impacts from the site. This water sampling and analysis plan (WSAP) recommends sampling six seeps and one upgradient monitor well compared in the Honaker Trail Formation. Samples will be taken in April 1994 (representative of high group water levels) and September 1994 (representative of low ground water levels). Analyses will be performed on filtered samples for plume indicator parameters.

  14. Geostatistical three-dimensional modeling of oolite shoals, St. Louis Limestone, southwest Kansas

    USGS Publications Warehouse

    Qi, L.; Carr, T.R.; Goldstein, R.H.

    2007-01-01

    In the Hugoton embayment of southwestern Kansas, reservoirs composed of relatively thin (<4 m; <13.1 ft) oolitic deposits within the St. Louis Limestone have produced more than 300 million bbl of oil. The geometry and distribution of oolitic deposits control the heterogeneity of the reservoirs, resulting in exploration challenges and relatively low recovery. Geostatistical three-dimensional (3-D) models were constructed to quantify the geometry and spatial distribution of oolitic reservoirs, and the continuity of flow units within Big Bow and Sand Arroyo Creek fields. Lithofacies in uncored wells were predicted from digital logs using a neural network. The tilting effect from the Laramide orogeny was removed to construct restored structural surfaces at the time of deposition. Well data and structural maps were integrated to build 3-D models of oolitic reservoirs using stochastic simulations with geometry data. Three-dimensional models provide insights into the distribution, the external and internal geometry of oolitic deposits, and the sedimentologic processes that generated reservoir intervals. The structural highs and general structural trend had a significant impact on the distribution and orientation of the oolitic complexes. The depositional pattern and connectivity analysis suggest an overall aggradation of shallow-marine deposits during pulses of relative sea level rise followed by deepening near the top of the St. Louis Limestone. Cemented oolitic deposits were modeled as barriers and baffles and tend to concentrate at the edge of oolitic complexes. Spatial distribution of porous oolitic deposits controls the internal geometry of rock properties. Integrated geostatistical modeling methods can be applicable to other complex carbonate or siliciclastic reservoirs in shallow-marine settings. Copyright ?? 2007. The American Association of Petroleum Geologists. All rights reserved.

  15. Mobilization of selenium from the Mancos Shale and associated soils in the lower Uncompahgre River Basin, Colorado

    USGS Publications Warehouse

    Mast, M. Alisa; Mills, Taylor J.; Paschke, Suzanne S.; Keith, Gabrielle; Linard, Joshua I.

    2014-01-01

    This study investigates processes controlling mobilization of selenium in the lower part of the Uncompahgre River Basin in western Colorado. Selenium occurs naturally in the underlying Mancos Shale and is leached to groundwater and surface water by limited natural runoff, agricultural and domestic irrigation, and leakage from irrigation canals. Soil and sediment samples from the study area were tested using sequential extractions to identify the forms of selenium present in solid phases. Selenium speciation was characterized for nonirrigated and irrigated soils from an agricultural site and sediments from a wetland formed by a leaking canal. In nonirrigated areas, selenium was present in highly soluble sodium salts and gypsum. In irrigated soils, soluble forms of selenium were depleted and most selenium was associated with organic matter that was stable under near-surface weathering conditions. Laboratory leaching experiments and geochemical modeling confirm that selenium primarily is released to groundwater and surface water by dissolution of highly soluble selenium-bearing salts and gypsum present in soils and bedrock. Rates of selenium dissolution determined from column leachate experiments indicate that selenium is released most rapidly when water is applied to previously nonirrigated soils and sediment. High concentrations of extractable nitrate also were found in nonirrigated soils and bedrock that appear to be partially derived from weathered organic matter from the shale rather than from agricultural sources. Once selenium is mobilized, dissolved nitrate derived from natural sources appears to inhibit the reduction of dissolved selenium leading to elevated concentrations of selenium in groundwater. A conceptual model of selenium weathering is presented and used to explain seasonal variations in the surface-water chemistry of Loutzenhizer Arroyo, a major tributary contributor of selenium to the lower Uncompahgre River.

  16. DDE mercury, and selenium in Biota, sediments, and water of the Rio Grande-Rio Bravo Basin, 1965-1995.

    PubMed

    Mora, M A; Wainwright, S E

    1998-01-01

    An assessment of contaminant stressors on biota of the Rio Grande was conducted to identify relevant contaminant issues, assess exposure and ecological effects, identify data gaps, and determine potential risks. Most contaminant data were from studies conducted during 1965-1995 in the Lower Rio Grande, on the Texas side of the river, within a 100-km boundary from Falcon Dam to the mouth. Contaminants most frequently reported were organochlorine compounds (OCs) and trace elements. The number of records for OCs and trace elements was at least twofold greater for fish than for birds, mammals, or reptiles. Of the OCs, p,p'-DDE was the most commonly reported. Among the trace elements, Hg was one of the most frequently reported; however, Se, As, Pb, Cu, and Zn were also common. The highest concentrations of OCs and trace elements were reported predominantly from Lower Rio Grande Valley locations, with approximately 68% of the highest values detected from Falcon Dam to the mouth of the river. Twenty-six (20%) of the locations with maximum concentrations corresponded to portions of Llano Grande Lake and the Arroyo Colorado. Recent analyses of birds and fish indicate that levels of DDE are currently much lower than in the 1970s or 1980s in Rio Grande wildlife. This apparent decline does not apply to Hg and Se levels in birds and fish, which have remained more or less constant, but may have increased over the years in some locations. Hg was of particular concern because of high levels found recently in addled eggs of aplomado falcons and in their potential prey. Hg was elevated in fish from the Big Bend area. Also, Se in fish sampled in 1993 and 1994 was near or above the threshold for potential effects in fish-eating wildlife. Future investigations should evaluate the potential impacts of Hg and Se on aquatic and terrestrial species from selected sites of concern. PMID:9751032

  17. Chronostratigraphy of Holocene alluvium in eastern Grand Canyon: Correlatable terraces or local paleoflood sequences?

    NASA Astrophysics Data System (ADS)

    Tainer, E. M.; Pederson, J. L.; Rittenour, T. M.; O'Brien, G. R.

    2008-12-01

    Understanding the nature of Colorado River deposits in Grand Canyon will help reveal how the river responds to changes in its Colorado Plateau tributaries and Rocky Mountain headwaters. This study focuses on Holocene alluvial deposits associated with archaeological sites excavated near Ninemile Draw in Glen Canyon and at Tanner Bar in eastern Grand Canyon. We are testing two previously-developed models of deposition. Hereford (1996) suggested that Holocene alluvial deposits in Grand Canyon are a series of inset aggradational packages that correlate to valley fills and arroyo cutting cycles identified in tributaries on the Colorado Plateau, and they should be laterally correlatable throughout the river corridor. An alternate hypothesis is that the alluvial packages record paleoflood sequences along the Colorado River with no change in river grade during the Holocene. In this model, deposition is preserved more randomly and varies by location because of differences in local hydrologic geometry. Three detailed stratigraphic columns of terrace deposits and several stratigraphic panels of archaeological trenches with facies interpretations have been used to reconstruct a high-resolution alluvial history of these locations. Optically stimulated luminescence (OSL) and radiocarbon dating methods were used at both locations with consistent results. At both sites, stratigraphy includes multiple depositional facies of both mainstem and locally-source material. Deposits consist of several sequences bound by unconformities. Ninemile Draw stratigraphy indicates three such sequences. At Tanner Bar, ages spanning the entire Holocene also reveal at least two distinct periods of deposition. Overall, the alluvium is composed of at least six discrete alluvial packages located at overlapping heights above river level throughout the canyon. Therefore, ages of the deposits cannot be distinguished by terrace level. The two oldest packages dated are early to middle Holocene, older than any

  18. Tektite-bearing, deep-water clastic unit at the Cretaceous-Tertiary boundary in northeastern Mexico

    SciTech Connect

    Smit, J. ); Montanari, A.; Swinburne, N.H.M.; Alvarez, W. ); Hildebrand, A.R. ); Margolis, S.V.; Claeys, P. ); Lowrie, W. ); Asaro, F. )

    1992-02-01

    The hypothesis of Cretaceous-Tertiary (K-T) boundary impact on Yucatan, Mexico, predicts that nearby sites should show evidence of proximal impact ejecta and disturbance by giant waves. An outcrop along the Arroyo el Mimbral in northeastern Mexico contains a layered clastic unit up to 3 m thick that interrupts a biostratigraphically complete pelagic-marl sequence deposited at more than 400 m water depth. The marls were found to be unsuitable for determining magnetostratigraphy, but foraminiferal biostratigraphy places the clastic unit precisely at the K-T boundary. The authors interpret this clastic unit as the deposit of a megawave or tsunami produced by an extraterrestrial impact. The clastic unit comprises three main subunits. (1) The basal 'spherule bed' contains glass in the form of tektites and microtektites, glass spherules replaced by chlorite-smectite and calcite, and quartz grains showing probable shock features. This bed is interpreted as a channelized deposit of proximal ejecta. (2) A set of lenticular, massive, graded 'laminated beds' contains intraclasts can abundant plant debris, and may the result of megawave backwash that carried coarse debris from shallow parts of the continental margin into deeper water. (3) At the top, several thin 'ripple beds' composed of fine sand are separated by clay drapes; they are interpreted as deposits of oscillating currents, perhaps a seiche. An iridium anomaly (921 {plus minus} 23 pg/g) is observed at the top of the ripple beds. Their observations at the Mimbral locality support the hypothesis of a K-T impact on nearby Yucatan.

  19. Tektite-bearing, deep-water clastic unit at the Cretaceous-Tertiary boundary in northeastern Mexico.

    PubMed

    Smit, J; Montanari, A; Swinburne, N H; Alvarez, W; Hildebrand, A R; Margolis, S V; Claeys, P; Lowrie, W; Asaro, F

    1992-02-01

    The hypothesis of Cretaceous-Tertiary (K-T) boundary impact on Yucatán, Mexico, predicts that nearby sites should show evidence of proximal impact ejecta and disturbance by giant waves. An outcrop along the Arroyo el Mimbral in northeastern Mexico contains a layered clastic unit up to 3 m thick that interrupts a biostratigraphically complete pelagic-marl sequence deposited at more than 400 m water depth. The marls were found to be unsuitable for determining magnetostratigraphy, but foraminiferal biostratigraphy places the clastic unit precisely at the K-T boundary. We interpret this clastic unit as the deposit of a megawave or tsunami produced by an extraterrestrial impact. The clastic unit comprises three main subunits. (1) The basal "spherule bed" contains glass in the form of tektites and microtektites, glass spherules replaced by chlorite-smectite and calcite, and quartz grains showing probable shock features. This bed is interpreted as a channelized deposit of proximal ejecta. (2) A set of lenticular, massive, graded "laminated beds" contains intraclasts and abundant plant debris, and may be the result of megawave backwash that carried coarse debris from shallow parts of the continental margin into deeper water. (3) At the top, several thin "ripple beds" composed of fine sand are separated by clay drapes; they are interpreted as deposits of oscillating currents, perhaps a seiche. An iridium anomaly (921 +/- 23 pg/g) is observed at the top of the ripple beds. Our observations at the Mimbral locality support the hypothesis of a K-T impact on nearby Yucatán. PMID:11537752

  20. Tektite-bearing, deep-water clastic unit at the Cretaceous-Tertiary boundary in northeastern Mexico

    NASA Technical Reports Server (NTRS)

    Smit, J.; Montanari, A.; Swinburne, N. H.; Alvarez, W.; Hildebrand, A. R.; Margolis, S. V.; Claeys, P.; Lowrie, W.; Asaro, F.

    1992-01-01

    The hypothesis of Cretaceous-Tertiary (K-T) boundary impact on Yucatan, Mexico, predicts that nearby sites should show evidence of proximal impact ejecta and disturbance by giant waves. An outcrop along the Arroyo el Mimbral in northeastern Mexico contains a layered clastic unit up to 3 m thick that interrupts a biostratigraphically complete pelagic-marl sequence deposited at more than 400 m water depth. The marls were found to be unsuitable for determining magnetostratigraphy, but foraminiferal biostratigraphy places the clastic unit precisely at the K-T boundary. We interpret this clastic unit as the deposit of a megawave or tsunami produced by an extraterrestrial impact. The clastic unit comprises three main subunits. (1) The basal "spherule bed" contains glass in the form of tektites and microtektites, glass spherules replaced by chlorite-smectite and calcite, and quartz grains showing probable shock features. This bed is interpreted as a channelized deposit of proximal ejecta. (2) A set of lenticular, massive, graded "laminated beds" contains intraclasts and abundant plant debris, and may be the result of megawave backwash that carried coarse debris from shallow parts of the continental margin into deeper water. (3) At the top, several thin "ripple beds" composed of fine sand are separated by clay drapes; they are interpreted as deposits of oscillating currents, perhaps a seiche. An iridium anomaly (921 +/- 23 pg/g) is observed at the top of the ripple beds. Our observations at the Mimbral locality support the hypothesis of a K-T impact on nearby Yucatan.

  1. Removing hexavalent chromium from subsurface waters with anion-exchange resin

    SciTech Connect

    Torres, R.A.

    1995-06-01

    Some subsurface waters at Lawrence Livermore National Laboratory (LLNL) are contaminated with volatile organic compounds (VOCs). Hexavalent chromium, Cr(VI), is also present in the ground water; however, the source of the Cr(VI) may be natural. The Cr(VI) still must be treated if brought to the surface because its concentration exceeds discharge standards. We are planning facilities for removing the VOCs and Cr(VI) to a level below the discharge standards. The planned treatment includes the following steps: (1) Pumping the water to the surface facility. (2) Purging the VOCs with air and absorbing them on activated carbon. The VOCs in LLNL`s subsurface waters are primarily chlorinated organic solvents, such as dichloroethylene (DCE), trichloroethylene (TCE), perchloroethylene (PCE), and chloroform (CHCl{sub 3}). Contamination levels range from tens to thousands of parts per billion. (3) Filtering the water. (4) Passing the water through anion-exchange resin to remove the Cr. The Cr in LLNL subsurface waters occurs almost entirely as Cr(VI), which exists as the chromate anion, CrO{sub 4}{sup 2-}, at environmental pH. Cr levels range from tens to hundreds of parts per billion. (5) Discharging the treated water into the local arroyos. The relevant discharge criteria are 5 ppb total VOCs, 11 ppb Cr(VI), and pH between 6.5 and 8.5, inclusive. This report describes laboratory experiments undertaken to learn how the proposed treatment facility can be expected to operate. The laboratory results are expected to supply vendors with the detailed performance specifications needed to prepare bids on the Cr removal portion of the treatment facility. The treatment facility is expected to process 60 gallons per minute (gpm) of water by stripping VOCs with 720 standard cubic feet per minute (scfm) of air and removing Cr(VI) with 60 ft{sup 3} of resin.

  2. Aquatic assemblages of the highly urbanized Santa Ana River Basin, California

    USGS Publications Warehouse

    Brown, L.R.; Burton, C.A.; Belitz, K.

    2005-01-01

    We assessed the structure of periphyton, benthic macroinvertebrate, and fish assemblages and their associations with environmental variables at 17 sites on streams of the highly urbanized Santa Ana River basin in Southern California. All assemblages exhibited strong differences between highly urbanized sites in the valley and the least-impacted sites at the transition between the valley and undeveloped mountains. Results within the urbanized area differed among taxa. Periphyton assemblages were dominated by diatoms (>75% of total taxa). Periphyton assemblages within the urbanized area were not associated with any of the measured environmental variables, suggesting that structure of urban periphyton assemblages might be highly dependent on colonization dynamics. The number of Ephemeroptera, Trichoptera, and Plecoptera (EPT) taxa included in macroinvertebrate assemblages ranged from 0 to 6 at urbanized sites. Benthic macroinvertebrate assemblages had significant correlations with several environmental variables within the urban area, suggesting that stream size and permanence were important determinants of distribution among the species able to survive conditions in urban streams. Only 4 of 16 fish species collected were native to the drainage. Fish assemblages of urbanized sites included two native species, arroyo chub Gila orcuttii and Santa Ana sucker Catostomus santaanae, at sites that were intermediate in coefficient of variation of bank-full width, depth, bed substrate, and water temperature. Alien species dominated urbanized sites with lesser or greater values for these variables. These results suggest that urban streams can be structured to enhance populations of native fishes. Continued study of urban streams in the Santa Ana River basin and elsewhere will contribute to the basic understanding of ecological principles and help preserve the maximum ecological value of streams in highly urbanized areas.

  3. The restructuring of the Environmental Restoration Program at Los Alamos National Laboratory

    SciTech Connect

    Jansen, J.

    1995-09-01

    The Los Alamos National Laboratory (Laboratory) has supported this country through 50 years of research and development primarily in the area of nuclear weapons and energy. As a result of the Laboratory`s activities, contamination of the environment occurred. The cleanup of contaminated areas and the prevention of further contamination has become an important part of the Laboratory`s new mission: the reduction of the nuclear danger. The cleanup of the Laboratory is somewhat unique. It is a very large site. It includes 43 square miles of Laboratory land that will continue to be in industrial use or under institutional control for decades or centuries to come. It also includes about 25 square miles of former Laboratory land that has been converted to residential use, the Los Alamos townsite. The unusual topography and hydrogeology of the site was shaped during the last million years through the eruption of a huge volcano and the ensuing erosion of the tuff-basalt plateau into 19 canyons and associated finger-like mesas. During the early phase of the Environmental Restoration (ER) Program, 2,100 sites were identified as potential release sites. Sites range from a few hundred square feet to a few acres in area. Contamination depths range from a few to 100 feet. Typical contaminants are chemicals, heavy metals, radioactive constituents, and high explosives. Of greatest concern are surface contamination, migration of the contaminants along the surface into creeks and arroyos of the canyons and ultimately into the Rio Grande, and migration through the earth into the drinking water aquifers.

  4. Evidence for community structure and habitat partitioning in coastal dune stiletto flies at the Guadalupe-Nipomo dunes system, California

    PubMed Central

    Holston, Kevin C.

    2005-01-01

    This study provides empirical evidence for habitat selection by North American species of stiletto flies (Diptera: Therevidae), based on local distributions of adults and immatures, and the first hypothesis of community assemblages proposed for a stiletto fly community. Sites at three localities within the Guadalupe-Nipomo dune system were sampled for stiletto flies in 1997 and 2001 by sifting sand, malaise trapping, and hand netting. Nine species were collected from four ecological zones and three intermediate ecological zones: Acrosathe novella (Coquillett), Brachylinga baccata (Loew), Nebritus powelli (Webb and Irwin), Ozodiceromyia sp., Pherocera sp., Tabudamima melanophleba (Loew), Thereva comata Loew, Thereva elizabethae Holston and Irwin, and Thereva fucata Loew. Species associations of adults and larvae with habitats and ecological zones were consistent among sites, suggesting that local distributions of coastal dune stiletto fly species are influenced by differences in habitat selection. In habitats dominated by the arroyo willow,Salix lasiolepsis, stiletto fly larvae of three species were collected in local sympatry, demonstrating that S. lasiolepsis stands along stabilized dune ridges can provide an intermediate ecological zone linking active dune and riparian habitat in the Guadalupe-Nipomo dune system. Sites dominated by European beach grass, Ammophilia arenaria, blue gum, Eucalyptus globulus, and Monterey cypress, Cupressus macrocarpa, are considered unsuitable for stiletto flies, which emphasizes the importance of terrestrial habitats with native vegetation for stiletto fly species. The local distributions of stiletto fly species at the Guadalupe-Nipomo dune system allow the community to be divided into three assemblages; active dune, pioneer scrub, and scrub-riparian. These assemblages may be applicable to other coastal dune stiletto fly communities, and may have particular relevance to stiletto fly species collected in European coastal dunes. The

  5. Evidence for community structure and habitat partitioning in coastal dune stiletto flies at the Guadalupe-Nipomo dunes system, California.

    PubMed

    Holston, Kevin C

    2005-01-01

    This study provides empirical evidence for habitat selection by North American species of stiletto flies (Diptera: Therevidae), based on local distributions of adults and immatures, and the first hypothesis of community assemblages proposed for a stiletto fly community. Sites at three localities within the Guadalupe-Nipomo dune system were sampled for stiletto flies in 1997 and 2001 by sifting sand, malaise trapping, and hand netting. Nine species were collected from four ecological zones and three intermediate ecological zones: Acrosathe novella (Coquillett), Brachylinga baccata (Loew), Nebritus powelli (Webb and Irwin), Ozodiceromyia sp., Pherocera sp., Tabudamima melanophleba (Loew), Thereva comata Loew, Thereva elizabethae Holston and Irwin, and Thereva fucata Loew. Species associations of adults and larvae with habitats and ecological zones were consistent among sites, suggesting that local distributions of coastal dune stiletto fly species are influenced by differences in habitat selection. In habitats dominated by the arroyo willow,Salix lasiolepsis, stiletto fly larvae of three species were collected in local sympatry, demonstrating that S. lasiolepsis stands along stabilized dune ridges can provide an intermediate ecological zone linking active dune and riparian habitat in the Guadalupe-Nipomo dune system. Sites dominated by European beach grass, Ammophilia arenaria, blue gum, Eucalyptus globulus, and Monterey cypress, Cupressus macrocarpa, are considered unsuitable for stiletto flies, which emphasizes the importance of terrestrial habitats with native vegetation for stiletto fly species. The local distributions of stiletto fly species at the Guadalupe-Nipomo dune system allow the community to be divided into three assemblages; active dune, pioneer scrub, and scrub-riparian. These assemblages may be applicable to other coastal dune stiletto fly communities, and may have particular relevance to stiletto fly species collected in European coastal dunes. The

  6. Groundwater-Quality Survey of the South Coast Aquifer of Puerto Rico, April 2 through May 30, 2007

    USGS Publications Warehouse

    Rodriguez, Jose M.; Gómez-Gómez, Fernando

    2009-01-01

    The increased potential for variability of groundwater quality in the South Coast aquifer of Puerto Rico due to saline water encroachment from the Caribbean Sea and from deep parts of the aquifer has become a major concern of water planners and managers. In an effort to determine the extent and sources of this encroachment, the U.S. Geological Survey (USGS) and the Puerto Rico Department of Natural and Environmental Resources conducted a synoptic groundwater-quality survey from April 2 through May 30, 2007, for the South Coast aquifer between Ponce and Arroyo (fig. 1). Groundwater resources in this aquifer extend 150 square miles in south-central Puerto Rico and provide an estimated 44.2 million gallons per day (Mgal/d) or about 61 percent of the total water needs. This amount includes: 15.3 Mgal/d for irrigation, 27.4 Mgal/d for public supply, and 1.5 Mgal/d for industrial and other uses (W.L. Molina-Rivera, U.S. Geological Survey, written commun., 2007). Since 1980 when most of the south coastal plain was intensively cultivated for sugarcane, total groundwater withdrawals have declined about 32 Mgal/d with the greatest decline occurring in irrigation (37.2 Mgal/d) and the greatest increase occurring in public supply (5.5 Mgal/d). Although withdrawals have declined substantially, a major concern is that aquifer recharge provided by irrigation return flow from surface-water irrigation canals has essentially dropped to zero because of the large-scale implementation of groundwater drip irrigation systems.

  7. Eleventh workshop on geothermal reservoir engineering: Proceedings

    SciTech Connect

    Ramey, H.J. Jr.; Kruger, P.; Miller, F.G.; Horne, R.N.; Brigham, W.E.; Counsil, J.R.

    1986-01-23

    The Eleventh Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 21-23, 1986. The attendance was up compared to previous years, with 144 registered participants. Ten foreign countries were represented: Canada, England, France, Iceland, Indonesia, Italy, Japan, Mexico, New Zealand and Turkey. There were 38 technical presentations at the Workshop which are published as papers in this Proceedings volume. Six technical papers not presented at the Workshop are also published and one presentation is not published. In addition to these 45 technical presentations or papers, the introductory address was given by J. E. Mock from the Department of Energy. The Workshop Banquet speaker was Jim Combs of Geothermal Resources International, Inc. We thank him for his presentation on GEO geothermal developments at The Geysers. The chairmen of the technical sessions made an important contribution to the Workshop. Other than Stanford faculty members they included: M. Gulati, E. Iglesias, A. Moench, S. Prestwich, and K. Pruess. The Workshop was organized by the Stanford Geothermal Program faculty, staff, and students. We would like to thank J.W. Cook, J.R. Hartford, M.C. King, A.E. Osugi, P. Pettit, J. Arroyo, J. Thorne, and T.A. Ramey for their valued help with the meeting arrangements and preparing the Proceedings. We also owe great thanks to our students who arranged and operated the audio-visual equipment. The Eleventh Workshop was supported by the Geothermal Technology Division of the U.S. Department of Energy through Contract DE-AS03-80SF11459. We deeply appreciate this continued support. January 1986 H.J. Ramey, Jr. P. Kruger R.N. Horne W.E. Brigham F.G. Miller J.R. Counsil

  8. Historical evolution of the drainage network at the basin scale using aerial orthophotography in Southern Spain

    NASA Astrophysics Data System (ADS)

    Castillo, Carlos; Mora, Jose; Gómez, Jose Alfonso

    2013-04-01

    Soil management has major implications on the drainage systems in agricultural catchments. Management practices, such as ploughing the gully perimeter and gully filling, remove the vegetation and natural features associated with natural streams contributing to the landscape simplification and accelerating erosion processes. This study evaluated the temporal evolution of several key parameters of the drainage network at the Arroyo Galapagares basin over a period of six decades, from a set of existing orthophotographies, since the first available (1956) to the present (2011). The area of the catchment is 80 km2, being representative of the Campiña, a rolling landscape covered by field crops on mostly Vertisol soils, in Southern Spain. The complete drainage network of the basin was digitized, defining the thalweg and the perimeter of the channels. Since the distinction between the actual channel surface and surrounding weed-covered surface is not reliable by means of merely orthophotography inspection, the limits between the field crops and the drainage network surface provided a measure of the magnitude of non-cultivated areas. Using the digitization results, the temporal variation of three parameters were assessed: network length, channel sinuosity and non-cultivated surface. The results of this analysis showed that a significant reduction of sinuosity occurred during the study period, as well as temporary decreases in the network length as a consequence of land levelling and gully filling. Moreover, a sustained growth of non-cultivated areas was observed at the upstream gullies (low-level order streams) due to the intensification of gully erosion, especially during the last decade.

  9. Geoarchaeological investigations at the Winger site: A Late Paleoindian bison bonebed in Southwestern Kansas, U.S.A

    USGS Publications Warehouse

    Mandel, R.D.; Hofman, J.L.

    2003-01-01

    The Winger site is a deeply buried Late Paleoindian bison bonebed in a playa basin on the High Plains of midcontinental North America. The site is one of few stratified, Late Paleoindian bison kills recorded in the region. The bonebed is exposed in the bank of an intermittent stream that cut into the edge of the playa basin. Avocational archaeologists excavated a small portion of the exposed bonebed in the early 1970s and reported flakes in association with the skeletal remains. Limited reinvestigations of the site were undertaken in 2001, and a monthlong excavation was conducted in 2002 to assess the stratigraphy, geochronology, and archaeology. The bonebed is 35 ni long in a buried soil developed in fine-grained basin fill overlain by early Holocene alluvium (arroyo fill). Recent alluvium overlies a soil developed in the early Holocene alluvium, and modern deposits of eolian sand 2 to to < 35 cm thick mantle the site area. Artifacts found at the site include two Allen points and a flake tool discovered in the bone bed, and a biface and Allen point fragment in disturbed bonebed deposits. Excavation of 9 m2 of the bone bed revealed some fully articulated skeletons, and taphonomic observations suggest some of the bison collapsed while standing in a playa or pond margin setting. The remains of at least six bison are represented in the excavated sample from 2002, but many more animals are represented in the bonebed. A 14C age of ca. 9000 yr B.P. was determined on collagen from bison rib fragments. This age is consistent with the diagnostic artifacts found at Winger. ?? 2003 Wiley Periodicals, Inc.

  10. Field guide to Cretaceous-tertiary boundary sections in northeastern Mexico

    NASA Technical Reports Server (NTRS)

    Keller, Gerta; Stinnesbeck, Wolfgang; Adatte, Thierry; Macleod, Norman; Lowe, Donald R.

    1994-01-01

    This guide was prepared for the field trip to the KT elastic sequence of northeastern Mexico, 5-8 February 1994, in conjunction with the Conference on New Developments Regarding the KT Event and Other Catastrophes in Earth History, held in Houston, Texas. The four-day excursion offers an invaluable opportunity to visit three key outcrops: Arroyo El Mimbral, La Lajilla, and El Pinon. These and other outcrops of this sequence have recently been interpreted as tsunami deposits produced by the meteorite impact event that produced the 200 to 300-km Chicxulub basin in Yucatan, and distributed ejecta around the world approximately 65 m.y. ago that today is recorded as a thin clay layer found at the K/T boundary. The impact tsunami interpretation for these rocks has not gone unchallenged, and others examining the outcrops arrive at quite different conclusions: not tsunami deposits but turbidites; not KT at all but 'upper Cretaceous.' Indeed, it is in hopes of resolving this debate through field discussion, outcrop evaluation, and sampling that led the organizers of the conference to sanction this field trip. This field guide provides participants with background information on the KT clastic sequence outcrops and is divided into two sections. The first section provides regional and logistical context for the outcrops and a description of the clastic sequence. The second section presents three representative interpretations of the outcrops by their advocates. There is clearly no way that these models can be reconciled and so two, if not all three, must be fundamentally wrong. Readers of this guide should keep in mind that many basic outcrop observations that these models are based upon remain unresolved. While great measures were taken to ensure that the information in the description section was as objective as possible, many observations are rooted in interpretations and the emphasis placed on certain observations depends to some degree upon the perspective of the author.

  11. Preferential flow in fissured sediments in desert soils related to radioactive waste disposal

    SciTech Connect

    Scanlon, B.R.; Raney, J.A. . Bureau of Economic Geology)

    1992-01-01

    Unsaturated flow in fissured sediments in the Chihuahuan Desert of Texas was examined to determine if these features act as preferred pathways for water and solute transport. Fissures are surface features, or gulleys, that are underlain by fractures filled with sediment derived from surrounding areas. Hydraulic and chemical approaches were used to investigate unsaturated flow processes beneath and adjacent to fissures, and the results were compared with data from surrounding geomorphic systems such as arroyos, ephemeral streams, and interstreams. Typically, high water potentials in surficial sediments result from infiltration of recent precipitation. Below this surficial zone of high water potentials lies a zone of low water potentials that is much thinner beneath the fissure than in adjacent sediments or in sediments beneath ephemeral streams and interstreams. Maximum chloride concentrations in profiles in the near-surface fissured sediments were much lower than those measured in all other geomorphic systems. The corresponding moisture velocities in the fissured sediments ranged from 10 to 70 mm/yr. A tracer experiment demonstrated higher downward water and solute transport in the fracture fill beneath the fissure relative to adjacent sediments. Numerical simulations of the tracer experiment with the computer code TRACR3D reproduced the overall shape of the tracer plume. Sensitivity analyses demonstrated that the tracer plume is most sensitive to spatial variability in soil texture and the corresponding hydraulic parameters. The results from this study suggest that sediments in the fissured area act as preferred pathways in the shallow subsurface because surface runoff is concentrated in the fissures and because underlying fractures and cavities provide avenues for moisture and solute transport.

  12. Sources of groundwater nitrate revealed using residence time and isotope methods

    SciTech Connect

    Moore, K B; Ekwurzel, B; Esser, B K; Hudson, G B; Moran, J E

    2004-10-07

    Nitrate concentrations approaching and greater than the maximum contaminant level (MCL) are impairing the viability of many groundwater basins as drinking water sources. Nitrate isotope data are effective in determining contaminant sources, especially when combined with other isotopic tracers such as stable isotopes of water and tritium-helium ages to give insight into the routes and timing of nitrate inputs to the flow system. This combination of techniques is demonstrated in Livermore, CA, where it is determined that low nitrate reclaimed wastewater predominates in the northwest, while two flowpaths with distinct nitrate sources originate in the southeast. Along the eastern flowpath, {delta}{sup 15}N values greater than 10{per_thousand} indicate that animal waste is the primary source. Diminishing concentrations over time suggest that contamination results from historical land use practices. The other flowpath begins in an area where rapid recharge, primarily of low-nitrate imported water (identified by stable isotopes of water and a tritium-helium residence time of less than 1 year), mobilizes a significant local nitrate source, bringing groundwater concentrations up to 53 mg NO{sub 3} L{sup -1}. In this area, artificial recharge of imported water via local arroyos increases the flux of nitrate to the regional aquifer. The low {delta}{sup 15}N value (3.1{per_thousand}) in this location implicates synthetic fertilizer. In addition to these anthropogenic sources, natural nitrate background levels between 15 and 20 mg NO{sub 3} L{sup -1} are found in deep wells with residence times greater than 50 years.

  13. Climate scenarios for the American Southwest in the next century

    SciTech Connect

    Diaz, H.F.

    1995-12-31

    The climate of the Southwest US is governed by two separate large-scale regimes during the course of the year. In the winter half-year, disturbances in the westerlies supply 40--80% of the annual total precipitation in the region. The precipitation is associated with frontal systems sweeping from the west and north through the area, and with the development of upper level troughs and occasional cutoff lows in the upper atmosphere. During the summer half-year, and particularly during the months of July--September, a monsoonal-type circulation system develops along western Mexico and extends into the desert areas of the US Southwest producing locally heavy thunderstorms and floods. In early fall, eastern Pacific hurricanes, occasionally recurving to the north and east across northwestern Mexico, can also produce widespread rains and locally severe flooding in the region. With regards to future changes in climate forced by increasing atmospheric greenhouse-gas concentrations, the question arises, as to whether the annual precipitation in the region will be more affected by changes in the winter-time regime, that is, through a modification of the polar jet stream and associated extratropical cyclone tracks, or whether an increase in the summer monsoon system will, at least in part, make up for a potential winter decline in precipitation. An increase in convective summer-season rainfall will also be accompanied by enhanced soil erosion, arroyo cutting, greater sediment loads in the region`s streams, and other problems. Climatic changes resulting from the enhanced greenhouse effect will be superimposed on a rich spectrum of naturally occurring climatic variability at the relevant time scales that are of interest here, namely, decadal to century fluctuations.

  14. Pre- and post-fire pollutant loads in an urban fringe watershed in Southern California.

    PubMed

    Burke, M P; Hogue, T S; Kinoshita, A M; Barco, J; Wessel, C; Stein, E D

    2013-12-01

    Post-fire runoff has the potential to be a large source of contaminants to downstream areas. However, the magnitude of this effect in urban fringe watersheds adjacent to large sources of airborne contaminants is not well documented. The current study investigates the impacts of wildfire on stormwater contaminant loading from the upper Arroyo Seco watershed, burned in 2009. This watershed is adjacent to the Greater Los Angeles, CA, USA area and has not burned in over 60 years. Consequently, it acts as a sink for regional urban pollutants and presents an opportunity to study the impacts of wildfire. Pre- and post-fire storm samples were collected and analyzed for basic cations, trace metals, and total suspended solids. The loss of vegetation and changes in soil properties from the fire greatly increased the magnitude of storm runoff, resulting in sediment-laden floods carrying high concentrations of particulate-bound constituents. Post-fire concentrations and loads were up to three orders of magnitude greater than pre-fire values for many trace metals, including lead and cadmium. A shift was also observed in the timing of chemical delivery, where maximum suspended sediment, trace metal, and cation concentrations coincided with, rather than preceded, peak discharge in the post-fire runoff, amplifying the fire's impacts on mass loading. The results emphasize the importance of sediment delivery as a primary mechanism for post-fire contaminant transport and suggest that traditional management practices that focus on treating only the early portion of storm runoff may be less effective following wildfire. We also advocate that watersheds impacted by regional urban pollutants have the potential to pose significant risk for downstream communities and ecosystems after fire. PMID:23912423

  15. Supplement analysis for Greenville Gate access to Kirschbaum Field at Lawrence Livermore National Laboratory

    SciTech Connect

    1997-12-05

    The National Ignition Facility (NIF) Program proposes to provide additional access to the Kirschbaum Field construction laydown area. This additional access would alleviate traffic congestion at the East Gate entrance to Lawrence Livermore National Laboratory (LLNL) from Greenville Road during periods of heavy construction for the NIF. The new access would be located along the northeastern boundary of LLNL, about 305 m (1,000 ft) north of the East Gate entrance. The access road would extend from Greenville Road to the Kirschbaum Field construction laydown area and would traverse an existing storm water drainage channel. Two culverts, side by side, and a compacted road base would be installed across the channel. The security fence that runs parallel to Greenville Road would be modified to accommodate this new entrance and a vehicle gate would be installed at the entrance of Kirschbaum Field. The exiting shoulder along Greenville Road would be converted into a new turn lane for trucks entering the new gate. This analysis evaluates the impacts of constructing the Kirschbaum Field bridge and access gate at a different location than was analyzed in the NIF Project specific Analysis in the Final Programmatic environmental Impact Statement for Stockpile Stewardship and Management (SS and M PEIS) published in September 1996 (DOE/EIS-0236) and the Record of Decision published on December 19, 1996. Issues of concern addressed in this supplement analysis include potential impacts to wetlands downstream of the access bridge, potential impacts to the California red-legged frog (Rana aurora draytonii) listed as threatened on the federal listing pursuant to the Endangered Species Act of 1974, and potential impacts on the 100-yr floodplain along the Arroyo Las Positas.

  16. 87Sr/86Sr sourcing of ponderosa pine used in Anasazi great house construction at Chaco Canyon, New Mexico

    USGS Publications Warehouse

    Reynolds, A.C.; Betancourt, J.L.; Quade, Jay; Patchett, P.J.; Dean, J.S.; Stein, J.

    2005-01-01

    Previous analysis of 87Sr/86Sr ratios shows that 10th through 12th century Chaco Canyon was provisioned with plant materials that came from more than 75 km away. This includes (1) corn (Zea mays) grown on the eastern flanks of the Chuska Mountains and floodplain of the San Juan River to the west and north, and (2) spruce (Picea sp.) and fir (Abies sp.) beams from the crest of the Chuska and San Mateo Mountains to the west and south. Here, we extend 87Sr/86Sr analysis to ponderosa pine (Pinus ponderosa) prevalent in the architectural timber at three of the Chacoan great houses (Pueblo Bonito, Chetro Ketl, Pueblo del Arroyo). Like the architectural spruce and fir, much of the ponderosa matches the 87Sr/86Sr ratios of living trees in the Chuska Mountains. Many of the architectural ponderosa, however, have similar ratios to living trees in the La Plata and San Juan Mountains to the north and Lobo Mesa/Hosta Butte to the south. There are no systematic patterns in spruce/fir or ponderosa provenance by great house or time, suggesting the use of stockpiles from a few preferred sources. The multiple and distant sources for food and timber, now based on hundreds of isotopic values from modern and archeological samples, confirm conventional wisdom about the geographic scope of the larger Chacoan system. The complexity of this procurement warns against simple generalizations based on just one species, a single class of botanical artifact, or a few isotopic values. ?? 2005 Elsevier Ltd. All rights reserved.

  17. An investigation on generalization ability of artificial neural networks and M5 model tree in modeling reference evapotranspiration

    NASA Astrophysics Data System (ADS)

    Kisi, Ozgur; Kilic, Yasin

    2015-08-01

    The generalization ability of artificial neural networks (ANNs) and M5 model tree (M5Tree) in modeling reference evapotranspiration (ET 0 ) is investigated in this study. Daily climatic data, average temperature, solar radiation, wind speed, and relative humidity from six different stations operated by California Irrigation Management Information System (CIMIS) located in two different regions of the USA were used in the applications. King-City Oasis Rd., Arroyo Seco, and Salinas North stations are located in San Joaquin region, and San Luis Obispo, Santa Monica, and Santa Barbara stations are located in the Southern region. In the first part of the study, the ANN and M5Tree models were used for estimating ET 0 of six stations and results were compared with the empirical methods. The ANN and M5Tree models were found to be better than the empirical models. In the second part of the study, the ANN and M5Tree models obtained from one station were tested using the data from the other two stations for each region. ANN models performed better than the CIMIS Penman, Hargreaves, Ritchie, and Turc models in two stations while the M5Tree models generally showed better accuracy than the corresponding empirical models in all stations. In the third part of the study, the ANN and M5Tree models were calibrated using three stations located in San Joaquin region and tested using the data from the other three stations located in the Southern region. Four-input ANN and M5Tree models performed better than the CIMIS Penman in only one station while the two-input ANN models were found to be better than the Hargreaves, Ritchie, and Turc models in two stations.

  18. Ground-water surface-water interactions and long-term change in riverine riparian vegetation in the southwestern United States

    USGS Publications Warehouse

    Webb, R.H.; Leake, S.A.

    2006-01-01

    Riverine riparian vegetation has changed throughout the southwestern United States, prompting concern about losses of habitat and biodiversity. Woody riparian vegetation grows in a variety of geomorphic settings ranging from bedrock-lined channels to perennial streams crossing deep alluvium and is dependent on interaction between ground-water and surface-water resources. Historically, few reaches in Arizona, southern Utah, or eastern California below 1530 m elevation had closed gallery forests of cottonwood and willow; instead, many alluvial reaches that now support riparian gallery forests once had marshy grasslands and most bedrock canyons were essentially barren. Repeat photography using more than 3000 historical images of rivers indicates that riparian vegetation has increased over much of the region. These increases appear to be related to several factors, notably the reduction in beaver populations by trappers in the 19th century, downcutting of arroyos that drained alluvial aquifers between 1880 and 1910, the frequent recurrence of winter floods during discrete periods of the 20th century, an increased growing season, and stable ground-water levels. Reductions in riparian vegetation result from agricultural clearing, excessive ground-water use, complete flow diversion, and impoundment of reservoirs. Elimination of riparian vegetation occurs either where high ground-water use lowers the water table below the rooting depth of riparian species, where base flow is completely diverted, or both. We illustrate regional changes using case histories of the San Pedro and Santa Cruz Rivers, which are adjacent watersheds in southern Arizona with long histories of water development and different trajectories of change in riparian vegetation.

  19. Evaluating dryland ecological and river restoration using repeat LiDAR and hydrological monitoring

    NASA Astrophysics Data System (ADS)

    Henderson, W. M.; DeLong, S.

    2012-12-01

    Recent improvements in the collection of multitemporal, high-resolution topographic data such as Light Detection and Ranging (LiDAR) have done a great deal to increase our ability to quantify the details of landscape change. Both Terrestrial Laser Scanning (TLS) and Airborne Laser Swath Mapping (ALSM) can be used to easily assess how Earth surface processes affect landscape form to a level of precision that was previously more difficult to attain. A comprehensive approach using ALSM, TLS-TLS comparison, and hydrological monitoring is being used to assess the effectiveness of a large scale ecological and river restoration effort by the Cuenca los Ojos Foundation at San Bernardino Ranch near Agua Prieta, Sonora, Mexico. In the study area, historical arroyo cutting and changes in land use led to the abandonment of a ciénega wetland and resulted in widespread ecological destruction. The current land managers have employed engineering methods in order to restore stream and ciénega ecology, including the installation of large rock gabions, earthen berms, and concrete spillways along channels. Our goal is to test the hypothesis that the use of dam and gabion structures leads to stream aggradation, flash flood dampening, and ultimately, increased available water and reestablishment of historic wetland plant and animal communities. We present results from LiDAR change detection that includes 2007-2011 ALSM to TLS change, and several 2011-2012 TLS-TLS comparisons. We also present results from streamflow monitoring, field observation, and monitoring of shallow groundwater and soil moisture conditions. Preliminary results show that channel aggradation occurs rapidly upstream of engineered structures. However, the apparent dampening of sediment transport by the structures leads to less aggradation and even incision immediately downstream of structures. Peak flood flows are decreased by the reservoirs formed behind large earthen berms. After several years of water retention

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

    USGS Publications Warehouse

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

    2013-01-01

    utilized Santa Barbara coastal zone, including Arroyo Burro Beach Park, Leadbetter Beach, East Beach, and “Butterfly Beach.” There are ongoing coastal erosion problems associated with both development and natural processes; between 1933–1934 and 1998, cliff erosion in the map area occurred at rates of about 0.1 to 1 m/yr, the largest amount (63 m) occurring at Arroyo Burro in the western part of the map area. In addition, development of the Santa Barbara Harbor, which began in 1928, lead to shoaling west of the harbor as the initial breakwater trapped sand, as well as to coastal erosion east of the harbor. Since 1959, annual harbor dredging has mitigated at least some of the downcoast erosion problems. The Offshore of Santa Barbara map area lies in the central part of the Santa Barbara littoral cell, which is characterized by littoral drift to the east-southeast. Drift rates have been estimated to be about 400,000 tons/yr at Santa Barbara Harbor. Sediment supply to the western and central parts of the littoral cell, including the map area, is largely from relatively small transverse coastal watersheds. Within the map area, these coastal watersheds include (from east to west) San Ysidro Creek, Oak Creek, Montecito Creek, Sycamore Creek, Mission Creek, Arroyo Burro, and Atascadero Creek. The Ventura and Santa Clara Rivers, the mouths of which are about 40 to 50 km southeast of Santa Barbara, are much larger sediment sources. Still farther east, eastward-moving sediment in the littoral cell is trapped by Hueneme and Mugu Canyons and then transported to the deep-water Santa Monica Basin. The offshore part of the map area consists of a relatively flat and shallow continental shelf, which dips gently seaward (about 0.4° to 0.8°) so that water depths at the 3-nautical-mile limit of California’s State Waters are about 45 m in the east and about 75 m in the west. This part of the Santa Barbara Channel is relatively well protected from large Pacific swells from the north

  1. Geology and ground-water hydrology of the Mokelumne area, California

    USGS Publications Warehouse

    Piper, A.M.; Gale, H.S.; Thomas, H.E.; Robinson, T.W.

    1939-01-01

    The Mokelumne River basin of central California comprises portions of the California Trough and the Sierra Nevada section of the Pacific Mountain system. The California Trough is divisible into four subsections-the Delta tidal plain, the Victor alluvial plain, tlie river flood plains and channels, and the Arroyo Seco dissected pediment. These four subsections comprise the land forms produced by the Mokelumne River and other streams since the Sierra Nevada attained its present height in the Pleistocene epoch. The Victor alluvial plain rises eastward from the Delta plain and abuts on the dissected Arroyo Seco pediment; in the Mokelumne area it is 12 to 16 miles wide and slopes between 5 and 8 feet in a mile. It includes relatively extensive tracts that are intensively cultivated and irrigated with water pumped from wells. The Victor plain has been compounded of overlapping alluvial fans along the western base of the Sierra Nevada. It is prolonged eastward into the pediment by tongues of alluvium along several of the present streams; thus it seems likely that the present stream pattern in the eastern part of the area has been fixed since dissection of the pediment began. Three of the four major streams-the Mokelumne and Cosumnes Rivers and Dry Creek-traverse the Victor plain in trenches which are 15 to 40 feet deep at the heads of their respective alluvial fans but which die out toward the west. The floors of these trenches, the historic flood plains, are from 100 yards to a mile wide. The exceptional major stream, which has not entrenched itself, is the Calaveras River. The Arroyo Seco pediment, which lies east of the Victor plain, was initially at least 8 to 15 miles wide and lay along the western foot of the Sierra Nevada entirely .across the Mokelumne area. Its numerous remnants decline 15 to 35 feet in a mile toward the west. The Sierra Nevada section adjoins and lies east of the California Trough. Its major ridge crests define a volcanic plain whose westward

  2. Hydrodynamic characteristics of the western Doñana Region (area of El Abalario), Huelva, Spain

    NASA Astrophysics Data System (ADS)

    Trick, Thomas; Custodio, Emilio

    The Doñana region, in southwestern Spain, comprises a large and important nature reserve, the wetlands of which are affected by human activity. Planting of an extensive eucalyptus forest in the 1950s and, more recently, the use of aquifers for irrigation and water supply for some coastal tourist resorts, have altered the natural groundwater-flow system. The area of the study is the western sector of the region, called El Abalario, which is a gentle topographic elevation between the Atlantic coast and La Rocina Creek (Arroyo de la Rocina). Underneath a variable layer of eolian sands with high dunes near the coast, thick Plio-Quaternary detritic strata, mostly fine silica sands, overlie marls. Near the base there is a variable, deltaic-origin layer of coarse sands and gravels. The dome-shaped water table, inside the sands, is close to the surface everywhere except beneath the dune belt, and small, temporary, shallow lagoons are numerous. The coarse sand and gravel layer conditions groundwater flow and behaves as a semiconfined layer between sands. A cross section through the area was simulated with a model to check the validity of the conceptual groundwater-flow pattern and its sensitivity to the hydraulic parameters. The model was calibrated using parameter values obtained by pumping tests and multilevel piezometric data, and checked against the estimated groundwater discharge into La Rocina Creek. Groundwater flows peripherally to the sea coast, to La Rocina Creek, or directly east and southeastward into the Doñana marshlands, in the Guadalquivir River delta. The average net aquifer recharge rate was calculated to be between 100 and 200 mm year-1 for the area covered by brush, but is remarkably lower in the areas of eucalyptus trees. The transient-state model shows that recharge varies spatially and is not clearly proportional to annual precipitation. Phreatic evapotranspiration plays an important role in decreasing the net value of aquifer recharge to

  3. Evidence for dextral transtensional development of the Rio Grande rift, from the Bear Mountains and the Lucero uplift, central New Mexico

    SciTech Connect

    Hayden, S.N. . Dept. of Geology)

    1993-04-01

    Dextral faulting of late Eocene age associated with latest Laramide deformation has been noted for some time along the margins of, and adjacent to, the Rio Grande rift (RGr) in central NM. Recent mapping of the Hell's Mesa (HM) fault zone in the Bear Mountains and of the Comanche/Santa Fe fault zone along the western margin of the RGr at the Lucero uplift has constrained dextral deformation to extend into the Miocene, at least, and possibly into the Pliocene. The HM fault zone forms the eastern margin of the Mulligan Gulch graben between the Bear and Gallinas Mountains to the west. The main ridge of the Bear Mountains is structurally down-dropped by the HM fault and is part of the graben. This ridge is a topographic high, composed of interbedded rhyolitic ash-flow tuffs and basaltic andesite flows of the Oligocene to early Miocene Mogollon-Datil volcanic field, faulted against Eocene sediments of the Baca Formation, and Eocene to early Oligocene volcanic and volcaniclastic rocks of the Datil Group. The western margin of the RGr in the Albuquerque basin along the Lucero uplift, defined by the Comanche fault zone is structurally continuous with portions of the HM fault zone that make a right overstep through the down-dropped Navajo gap area at the southwest corner of the basin. The Comanche fault zone shows dextral-oblique shear geometry along an anastomosing zone of faulting up to 1 km wide. This zone has been intruded by hypabyssal basaltic rocks that have yielded a whole-rock K-Ar date of 27.1 Ma. In the Carrizo Arroyo (CA) area, slickenside lineations on these dikes show a strong dextral component of movement similar to that of the HM zone. The Santa Fe fault is a reverse fault for some distance north of CA. Motion on this fault has disrupted coarse sediments that contain clasts of the ca. 4.0 Ma Carrizo Mesa basalt. These observations are interpreted to indicate that dextral deformation has persisted at least through the earliest stage of extension.

  4. The Strontium Fingerprint and Footprint: Using 87Sr/86Sr to Find the Sources and Range of Architectural Timber Acquisition of Great House Construction at Chaco Canyon, New Mexico

    NASA Astrophysics Data System (ADS)

    English, N. B.; Reynolds, A. C.; Quade, J.; Betancourt, J. L.

    2006-12-01

    We describe the spatial and temporal patterns of timber acquisition by great house builders in Chaco Canyon, New Mexico. The 87Sr/86Sr ratios from annually-dated, architectural logs in 10^{th} to 12^{th} century structures are compared to the 87Sr/86Sr of modern tree stands from the surrounding mountains. Although not a stable isotope system, the long half-life of the 87Sr parent (87Rb, t1/2 = 48.8 Ga) yields a stable isotope system on the timescales used to determine the geographic origin of ecosystem resources. The small mass difference among strontium's isotopes eliminates measurable biologic or kinetic fractionation at earth surface conditions. Strontium tracer studies, however, do require distinct end-member ratios to be feasible. Strontium isotopes, alone or in combination with other isotopes, provide a simple way to study and trace the geographic origin of ecosystem resources. Over the 150 km-wide Chaco Basin, 87Sr/86Sr ratios of modern trees range from 0.7055 to 0.7192. 87Sr/86Sr ratios from this and other studies show that during great house construction Chaco Canyon was provisioned with plant materials that came from more than 75 km away in all directions. This includes (1) corn (Zea mays) grown on the eastern flanks of the Chuska Mountains and floodplain of the San Juan River to the west and north, (2) spruce (Picea sp.) and fir (Abies sp.) architectural beams from the high crests of the Chuska and San Mateo Mountains to the west and south, and (3) ponderosa pine (Pinus ponderosa) from the low slopes of the La Platas and San Juan Mountains to the north, the San Pedro Mountains to the east, the Chuska and San Mateo Mountains and nearby mesas. There are no systematic patterns in spruce/fir or ponderosa provenance by great house (Pueblo Bonito, Chetro Ketl, Pueblo del Arroyo) or by time, suggesting the use of stockpiles from a few preferred sources from the beginning of large scale construction in or around Chaco Canyon. This is contrary to the view that

  5. Characterization and evaluation of channel and hillslope erosion on the Zuni Indian Reservation, New Mexico, 1992-95

    USGS Publications Warehouse

    Gellis, A.C.

    1998-01-01

    Like many areas of the southwestern United States, the Zuni Indian Reservation, New Mexico, has high rates of erosion, ranging from 95 to greater than 1,430 cubic meters per square kilometer per year. Erosion on the Zuni Indian Reservation includes channel erosion (arroyo incision and channel widening) and hillslope (sheetwash) erosion. The U.S. Geological Survey conducted a 3-year (1992-95) study on channel erosion and hillslope erosion in the portion of the Rio Nutria watershed that drains entirely within the Zuni Indian Reservation. Results of the study can be used by the Zuni Tribe to develop a plan for watershed rehabilitation. Channel changes, gully growth, headcuts, and changes in dirt roads over time were examined to characterize and evaluate channel erosion in the Rio Nutria watershed. Channel cross-sectional changes included width, depth, width-to-depth ratio, area, and geometry. Relative rates of gully growth, headcuts, and changes in dirt roads over time were examined using aerial photographs. Results of resurveys conducted between 1992 and 1994 of 85 channel cross sections indicated aggradation of 72 percent of cross sections in three subbasins of the Rio Nutria watershed. Forty-eight percent of resurveyed cross sections showed an increase in cross-sectional area and erosion; nine of these are in tributaries. Some channels (43 percent) aggraded and increased in cross-sectional area. This increase in cross- sectional area is due mostly to widening. Channel widening is a more pervasive form of erosion than channel scour on the Zuni Indian Reservation. The tops of channels widened in 67 percent and the bottoms of channels widened in 44 percent of resurveyed cross sections. Narrow, deep triangular channels are more erosive than rectangular cross sections. Five land-cover types--three sites on mixed-grass pasture, two sites on sites on unchained pi?on and juniper, one site on sagebrush, one site on ponderosa pine, and two sites on chained pi?on and juniper

  6. A revised burial dose estimation procedure for optical dating of youngand modern-age sediments

    USGS Publications Warehouse

    Arnold, L.J.; Roberts, R.G.; Galbraith, R.F.; DeLong, S.B.

    2009-01-01

    The presence of genuinely zero-age or near-zero-age grains in modern-age and very young samples poses a problem for many existing burial dose estimation procedures used in optical (optically stimulated luminescence, OSL) dating. This difficulty currently necessitates consideration of relatively simplistic and statistically inferior age models. In this study, we investigate the potential for using modified versions of the statistical age models of Galbraith et??al. [Galbraith, R.F., Roberts, R.G., Laslett, G.M., Yoshida, H., Olley, J.M., 1999. Optical dating of single and multiple grains of quartz from Jinmium rock shelter, northern Australia: Part I, experimental design and statistical models. Archaeometry 41, 339-364.] to provide reliable equivalent dose (De) estimates for young and modern-age samples that display negative, zero or near-zero De estimates. For this purpose, we have revised the original versions of the central and minimum age models, which are based on log-transformed De values, so that they can be applied to un-logged De estimates and their associated absolute standard errors. The suitability of these 'un-logged' age models is tested using a series of known-age fluvial samples deposited within two arroyo systems from the American Southwest. The un-logged age models provide accurate burial doses and final OSL ages for roughly three-quarters of the total number of samples considered in this study. Sensitivity tests reveal that the un-logged versions of the central and minimum age models are capable of producing accurate burial dose estimates for modern-age and very young (<350??yr) fluvial samples that contain (i) more than 20% of well-bleached grains in their De distributions, or (ii) smaller sub-populations of well-bleached grains for which the De values are known with high precision. Our results indicate that the original (log-transformed) versions of the central and minimum age models are still preferable for most routine dating applications

  7. Alkaline magmatism in the Amambay area, NE Paraguay: The Cerro Sarambí complex

    NASA Astrophysics Data System (ADS)

    Gomes, C. B.; Velázquez, V. F.; Azzone, R. G.; Paula, G. S.

    2011-07-01

    The Early Cretaceous alkaline magmatism in the northeastern region of Paraguay (Amambay Province) is represented by stocks, plugs, dikes, and dike swarms emplaced into Carboniferous to Triassic-Jurassic sediments and Precambrian rocks. This magmatism is tectonically related to the Ponta Porã Arch, a NE-trending structural feature, and has the Cerro Sarambí and Cerro Chiriguelo carbonatite complexes as its most significant expressions. Other alkaline occurrences found in the area are the Cerro Guazú and the small bodies of Cerro Apuá, Arroyo Gasory, Cerro Jhú, Cerro Tayay, and Cerro Teyú. The alkaline rocks comprise ultramafic-mafic, syenitic, and carbonatitic petrographic associations in addition to lithologies of variable composition and texture occurring as dikes; fenites are described in both carbonatite complexes. Alkali feldspar and clinopyroxene, ranging from diopside to aegirine, are the most abundant minerals, with feldspathoids (nepheline, analcime), biotite, and subordinate Ti-rich garnet; minor constituents are Fe-Ti oxides and cancrinite as the main alteration product from nepheline. Chemically, the Amambay silicate rocks are potassic to highly potassic and have miaskitic affinity, with the non-cumulate intrusive types concentrated mainly in the saturated to undersaturated areas in silica syenitic fields. Fine-grained rocks are also of syenitic affiliation or represent more mafic varieties. The carbonatitic rocks consist dominantly of calciocarbonatites. Variation diagrams plotting major and trace elements vs. SiO 2 concentration for the Cerro Sarambí rocks show positive correlations for Al 2O 3, K 2O, and Rb, and negative ones for TiO 2, MgO, Fe 2O 3, CaO, P 2O 5, and Sr, indicating that fractional crystallization played an important role in the formation of the complex. Incompatible elements normalized to primitive mantle display positive spikes for Rb, La, Pb, Sr, and Sm, and negative for Nb-Ta, P, and Ti, as these negative anomalies are

  8. Satellite-Based Investigations of the Transition from an Oceanic to Continental Transform Margin

    NASA Technical Reports Server (NTRS)

    Miller, M. Meghan

    1998-01-01

    Detailed characterization of neotectonics evolution of the Valle de San Felipe and Arroyo Grande regions in northern Baja California. Reoccupied GEOMEX GPS sites, and occupied a regional GPS (Global Positioning System) network. The Baja California peninsula in Mexico offers a unique setting for studying the kinematic evolution of a complex, active strike-slip/rift plate boundary. We are currently conducting remote sensing, geologic, and geodetic studies of this boundary. The combined data sets will yield instantaneous and time integrated views of its evolution. This proposal solicits renewed funding from NASA to support remote sensing and geologic studies. During the late Cenozoic, Baja California has been the locus of changing fault geometry that has accommodated components of the relative motion between the North America and Pacific plates. Contemporary slip between the two plates occurs in a broad zone that encompasses much of southern California and the Baja California Peninsula. The transfer of slip across this zone in southern California is relatively well understood. South of the border, the geometry and role of specific faults and structural provinces in transferring plate margin deformation across the peninsula is enigmatic. Results We use Landsat Thematic Mapper imagery of the Baja California Peninsula to identify recent and active faults, and then conduct field studies that characterize the temporal and spatial structural evolution of the plate margin. These data address questions concerning the neotectonic development of the Gulf of California, the Baja California Peninsula, and their role in evolution of the post-Miocene Pacific - North American plate boundary. Moreover, these studies provide constraints on the geometry of active faults, allowing more exact understanding of the results of ongoing NASA-supported geodetic experiments. In addition, anticipated publication of the TM scenes will provide a widely available geological data base for relatively

  9. High spatial resolution geochemistry and textural characteristics of 'microtektite' glass spherules in proximal Cretaceous-Paleogene sections: Insights into glass alteration patterns and precursor melt lithologies

    NASA Astrophysics Data System (ADS)

    Belza, Joke; Goderis, Steven; Smit, Jan; Vanhaecke, Frank; Baert, Kitty; Terryn, Herman; Claeys, Philippe

    2015-03-01

    Using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), we have conducted spatially resolved trace element analysis on fresh, unaltered microtektite glasses linked to the Cretaceous-Paleogene (K-Pg) boundary Chicxulub crater and on their surrounding alteration phases. This unique approach offers the opportunity to study in situ and at high spatial resolution both the mixing of different target lithologies and the variation of the major and trace element budget during the alteration process. In addition, two-dimensional element distribution maps reveal important geochemical information beyond the capabilities of single spot laser drilling. Glasses from two localities in opposite quadrants from the source crater were studied. At the Beloc locality (Haiti), the glass population is dominated by the presence of yellow high-Ca glass and black andesitic glass formed by admixture of carbonate/dolomite/anhydrite platform lithologies with crystalline basement. These glasses alter according to the well-established hydration-palagonitization model postulated for mafic volcanic glasses. REEs become progressively leached from the glass to below the detection limit for the applied spot size, while immobile Zr, Hf, Nb, and Ta passively accumulate in the process exhibiting both inter-element ratios and absolute concentrations similar to those for the original glass. In contrast, The Arroyo El Mimbral locality (NE Mexico) is characterized by abundant green glass fragments high in Si, Al and alkalis, and low in Mg, Ca, Fe. Low Si black glass is less abundant though similar in composition to the black glass variety at Beloc. The alteration pattern of high-Si, Al green glass at the Mimbral locality is more complex, including numerous competing reaction processes (ion-exchange, hydration, dissolution, and secondary mineral precipitation) generally controlled by the pH and composition of the surrounding fluid. All green, high-Si, Al glasses are hydrated and

  10. Single Mutation in the Flavivirus Envelope Protein Hinge Region Increases Neurovirulence for Mice and Monkeys but Decreases Viscerotropism for Monkeys: Relevance to Development and Safety Testing of Live, Attenuated Vaccines

    PubMed Central

    Monath, Thomas P.; Arroyo, Juan; Levenbook, Inessa; Zhang, Zhen-Xi; Catalan, John; Draper, Ken; Guirakhoo, Farshad

    2002-01-01

    A chimeric yellow fever (YF) virus/Japanese encephalitis (JE) virus vaccine (ChimeriVax-JE) was constructed by insertion of the prM-E genes from the attenuated JE virus SA14-14-2 vaccine strain into a full-length cDNA clone of YF 17D virus. Passage in fetal rhesus lung (FRhL) cells led to the emergence of a small-plaque virus containing a single Met→Lys amino acid mutation at E279, reverting this residue from the SA14-14-2 to the wild-type amino acid. A similar virus was also constructed by site-directed mutagenesis (J. Arroyo, F. Guirakhoo, S. Fenner, Z.-X. Zhang, T. P. Monath, and T. J. Chambers, J. Virol. 75:934-942, 2001). The E279 mutation is located in a beta-sheet in the hinge region of the E protein that is responsible for a pH-dependent conformational change during virus penetration from the endosome into the cytoplasm of the infected cell. In independent transfection-passage studies with FRhL or Vero cells, mutations appeared most frequently in hinge 4 (bounded by amino acids E266 to E284), reflecting genomic instability in this functionally important region. The E279 reversion caused a significant increase in neurovirulence as determined by the 50% lethal dose and survival distribution in suckling mice and by histopathology in rhesus monkeys. Based on sensitivity and comparability of results with those for monkeys, the suckling mouse is an appropriate host for safety testing of flavivirus vaccine candidates for neurotropism. After intracerebral inoculation, the E279 Lys virus was restricted with respect to extraneural replication in monkeys, as viremia and antibody levels (markers of viscerotropism) were significantly reduced compared to those for the E279 Met virus. These results are consistent with the observation that empirically derived vaccines developed by mouse brain passage of dengue and YF viruses have increased neurovirulence for mice but reduced viscerotropism for humans. PMID:11799188