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Sample records for age reservoirs west

  1. 5. EASTSIDE RESERVOIR, LOOKING WEST. WEST DAM UNDER CONSTRUCTION, QUARRIES ...

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

    5. EASTSIDE RESERVOIR, LOOKING WEST. WEST DAM UNDER CONSTRUCTION, QUARRIES TO LEFT MIDDLE GROUND OF PICTURE. - Eastside Reservoir, Diamond & Domenigoni Valleys, southwest of Hemet, Hemet, Riverside County, CA

  2. INTEGRATED OUTCROP AND SUBSURFACE STUDIES OF THE INTERWELL ENVIRONMENT OF CARBONATE RESERVOIRS: CLEAR FORK (LEONARDIAN-AGE) RESERVOIRS, WEST TEXAS AND NEW MEXICO

    SciTech Connect

    F. Jerry Lucia

    2002-01-31

    This is the final report of the project ''Integrated Outcrop and Subsurface Studies of the Interwell Environment of Carbonate Reservoirs: Clear Fork (Leonardian-Age) Reservoirs, West Texas and New Mexico'', Department of Energy contract no. DE-AC26-98BC15105 and is the third in a series of similar projects funded jointly by the U.S. Department of Energy and The University of Texas at Austin, Bureau of Economic Geology, Reservoir Characterization Research Laboratory for Carbonates. All three projects focus on the integration of outcrop and subsurface data for the purpose of developing improved methods for modeling petrophysical properties in the interwell environment. The first project, funded by contract no. DE-AC22-89BC14470, was a study of San Andres outcrops in the Algerita Escarpment, Guadalupe Mountains, Texas and New Mexico, and the Seminole San Andres reservoir, Permian Basin. This study established the basic concepts for constructing a reservoir model using sequence-stratigraphic principles and rock-fabric, petrophysical relationships. The second project, funded by contract no. DE-AC22-93BC14895, was a study of Grayburg outcrops in the Brokeoff Mountains, New Mexico, and the South Cowden Grayburg reservoir, Permian Basin. This study developed a sequence-stratigraphic succession for the Grayburg and improved methods for locating remaining hydrocarbons in carbonate ramp reservoirs. The current study is of the Clear Fork Group in Apache Canyon, Sierra Diablo Mountains, West Texas, and the South Wasson Clear Fork reservoir, Permian Basin. The focus was on scales of heterogeneity, imaging high- and low-permeability layers, and the impact of fractures on reservoir performance. In this study (1) the Clear Fork cycle stratigraphy is defined, (2) important scales of petrophysical variability are confirmed, (3) a unique rock-fabric, petrophysical relationship is defined, (4) a porosity method for correlating high-frequency cycles and defining rock-fabric flow layers

  3. 2. EASTSIDE RESERVOIR UNDER CONSTRUCTION LOOKING WEST WITH EAST DAM ...

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

    2. EASTSIDE RESERVOIR UNDER CONSTRUCTION LOOKING WEST WITH EAST DAM IN MIDDLE GROUND, WEST DAM IN DISTANCE. - Eastside Reservoir, Diamond & Domenigoni Valleys, southwest of Hemet, Hemet, Riverside County, CA

  4. Integrated Outcrop and Subsurface Studies of the Interwell Environment of Carbonate Reservoirs: Clear Fork (Leonaradian Age) Reservoirs, West Texas and New Mexico

    SciTech Connect

    Lucia, F. Jerry; Jennings, Jr., James W.

    2001-05-08

    A preliminary reservoir model was constructed for the Lower Clear Fork of the South Wasson Clear Fork reservoir. The model was constructed by calibrating high-frequency cycles observed in cores to the porosity log. The rock fabrics mostly fall in petrophysical class 1, and cross plots of porosity and water saturation could not be used to identify rock fabrics. Data from two limestone fields and one dolostone field were presented to support the contention that grain-dominated fabrics have higher porosity than mud-dominated fabrics do and that this difference is retained when the limestone is dolomitized.

  5. INTEGRATED OUTCROP AND SUBSURFACE STUDIES OF THE INTERWELL ENVIRONMENT OF CARBONATE RESERVOIRS: CLEAR FORK (LEONARADIAN AGE) RESERVOIRS, WEST TEXAS AND NEW MEXICO

    SciTech Connect

    James W. Jennings, Jr.; F. Jerry Lucia

    2001-10-01

    Petrophysical heterogeneity in the South Wasson Clear Fork (SWCF) reservoir and other shallow-water platform carbonates in the Permian Basin and elsewhere is composed of a large-scale stratigraphically controlled component and a small-scale poorly correlated component. The large-scale variability exists as a flow-unit scale petrophysical layering that is laterally persistent at interwell scales and produces highly stratified reservoir behavior. Capturing the rate-enhancing effect of the small-scale variability requires carefully controlled averaging procedures at four levels of scaleup. Porosity can be easily scaled using arithmetic averaging procedures. Permeability, however, requires carefully controlled power-averaging procedures. Effective permeability is increased at every scaleup level.

  6. Integrated Outcrop and Subsurface Studies of the Interwell Environment of Carbonate Reservoirs: Clear Fork (Leonaradian Age) Reservoirs, West Texas and New Mexico, Semi-Annual

    SciTech Connect

    Ruppel, Stephen C.; Jennings, James W.; Laubach, Stephen E.

    2001-11-29

    Outcrop studies include stratigraphic and petrophysical analysis. Analysis of the detailed sequence- and cycle-scale architecture of the Clear Fork reservoir-equivalent outcrops in Apache Canyon is nearly complete. This work reveals two high-frequency transgressive-regressive sequences (HFS) in the lower Clear Fork composite depositional sequence and three HFS in the basal middle Clear Fork composite depositional sequence. A 1,800-ft transect of 1-inch-diameter samples was collected from one cycle at the Apache Canyon outcrop. The transect was sampled with 5-ft spacing, but there were some gaps due to cover and cliff, resulting in 181 samples. Permeability, porosity, and grain density were measured, and the spatial statistics are being analyzed geostatistically.

  7. VIEW LOOKING WEST. THE SOUTH END OF SETTLING RESERVOIR NO. ...

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

    VIEW LOOKING WEST. THE SOUTH END OF SETTLING RESERVOIR NO. 3 AND JONES STREET ARE AT THE LEFT. SETTLING RESERVOIRS NO. 1 AND NO. 2 ARE AT THE FAR CENTER. THE SOUTHEAST CORNER OF SETTLING RESERVOIR NO. 3 IS AT THE BOTTOM. - Yuma Main Street Water Treatment Plant, Jones Street at foot of Main Street, Yuma, Yuma County, AZ

  8. VIEW LOOKING WEST TOWARD RESERVOIR HILL. THE SPRR HOTEL WAS ...

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

    VIEW LOOKING WEST TOWARD RESERVOIR HILL. THE SPRR HOTEL WAS LOCATED IN THE STRIPED AREA AT THE BOTTOM OF THE IMAGE, AND THE TRACK RAN BETWEEN THE HILL AND THE HOTEL. - Southern Pacific Railroad Water Settling Reservoir, Yuma Crossing, south bank of Colorado River at foot of Madison Avenue, Yuma, Yuma County, AZ

  9. Paleokarst, karst related diagenesis and reservoir development: Examples from Ordovician-Devonian age strata of west Texas and the Mid-continent

    SciTech Connect

    Candelaria, M.P.; Reed, C.L.

    1992-01-01

    This publication served as a guidebook for a Permian Basin Section-SEPM field trip to examine exposures of paleokarst in lower Paleozoic platform carbonates of West Texas and New Mexico. Included are road logs for the field trips and a collection of eighteen papers and abstracts that focus on various aspects of paleokarst in shallow-water carbonates including: (1) recognition and classification of karst-related textures in outcrop and the subsurface; (2) sequence stratigraphic analysis of karsted platforms; (3) diagenetic products of karstification; and (4) production characteristics of karst reservoirs. Collectively, these papers provide excellent documentation of sedimentary fabrics and diagenetic products associated with paleokarst development resulting from regional exposure of Cambro-Ordovician and Siluro-Devonian carbonates of the Great American Bank.'' The major value of this volume lies in the integration of a variety of approaches for examining processes and products related to karstification. These include the use of core, outcrop, well logs, and computer modeling to better understand paleokarst development and preservation. Some of the more interesting articles are highlighted below.

  10. VIEW LOOKING SOUTHEAST TOWARD WEST SIDE OF SETTLING RESERVOIR NO. ...

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

    VIEW LOOKING SOUTHEAST TOWARD WEST SIDE OF SETTLING RESERVOIR NO. 1. THE BLAISDELL SLOW SAND FILTER WASHING MACHINE IS SEEN AT THE LEFT. MAIN STREET IS IN THE FOREGROUND. - Yuma Main Street Water Treatment Plant, Jones Street at foot of Main Street, Yuma, Yuma County, AZ

  11. 91. FAIRMONT RESERVOIR, LOOKING WEST/NORTHWEST Los Angeles Aqueduct, From ...

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

    91. FAIRMONT RESERVOIR, LOOKING WEST/NORTHWEST - Los Angeles Aqueduct, From Lee Vining Intake (Mammoth Lakes) to Van Norman Reservoir Complex (San Fernando Valley), Los Angeles, Los Angeles County, CA

  12. Does reservoir host mortality enhance transmission of West Nile virus?

    PubMed Central

    Foppa, Ivo M; Spielman, Andrew

    2007-01-01

    Background Since its 1999 emergence in New York City, West Nile virus (WNV) has become the most important and widespread cause of mosquito-transmitted disease in North America. Its sweeping spread from the Atlantic to the Pacific coast was accompanied by widespread mortality among wild birds, especially corvids. Only sporadic avian mortality had previously been associated with this infection in the Old World. Here, we examine the possibility that reservoir host mortality may intensify transmission, both by concentrating vector mosquitoes on remaining hosts and by preventing the accumulation of "herd immunity". Results Inspection of the Ross-Macdonald expression of the basic reproductive number (R0) suggests that this quantity may increase with reservoir host mortality. Computer simulation confirms this finding and indicates that the level of virulence is positively associated with the numbers of infectious mosquitoes by the end of the epizootic. The presence of reservoir incompetent hosts in even moderate numbers largely eliminated the transmission-enhancing effect of host mortality. Local host die-off may prevent mosquitoes to "waste" infectious blood meals on immune host and may thus facilitate perpetuation and spread of transmission. Conclusion Under certain conditions, host mortality may enhance transmission of WNV and similarly maintained arboviruses and thus facilitate their emergence and spread. The validity of the assumptions upon which this argument is built need to be empirically examined. PMID:17498307

  13. Recognition and significance of parasequences and parasequence sets in Leonard carbonate reservoirs, west Texas

    SciTech Connect

    Ruppel, S.C. )

    1991-03-01

    Although hydrocarbon production from reservoirs of Leonardian age is sizable (cumulative production from the Leonardian on the Central Basin Platform (CBP) alone totals 1.4 billion bbls), recovery efficiencies from these restricted, shallow-water platform carbonate deposits are among the lowest in west Texas, averaging only about 19%. Detailed examination of the Leonard section in the Dollarhide and Monahans fields on the CBP indicates that poor recovery from these reservoirs is a function of extreme vertical heterogeneity produced by high-order oscillations of relative sea level. The Leonard sequence is composed of thin (1- to 2-m thick), upward-shallowing parasequences, each of which is marked at its base by a prominent marine flooding surface. Parasequences are, in turn, packaged into 15- to 20-m parasequence set defined by variations in parasequence facies stacking patterns. Reservoir porosity is typically preferentially developed in very thin (less than 1 m) zones of grain-rich subtidal facies within parasequences, although porosity may also be encountered in capping tidal-flat deposits. Because these facies display distinct pore and permeability characteristics, with subtidal facies usually exhibiting the highest permeabilities, development of accurate reservoir models for simulation and exploitation depends on the ability to distinguish and map these deposits. Recognition and correlation of parasequences and parasequence stacking patterns in parasequence sets provide a powerful tool for more accurate mapping of facies and attendant porosity development and facilitate development of improved models necessary for efficient exploitation of these highly heterogeneous reservoirs.

  14. Functional age as an indicator of reservoir senescence

    USGS Publications Warehouse

    Miranda, Leandro E.; Krogman, R. M.

    2015-01-01

    It has been conjectured that reservoirs differ in the rate at which they manifest senescence, but no attempt has been made to find an indicator of senescence that performs better than chronological age. We assembled an indicator of functional age by creating a multimetric scale consisting of 10 metrics descriptive of reservoir environments that were expected to change directionally with reservoir senescence. In a sample of 1,022 U.S. reservoirs, chronological age was not correlated with functional age. Functional age was directly related to percentage of cultivated land in the catchment and inversely related to reservoir depth. Moreover, aspects of reservoir fishing quality and fish population characteristics were related to functional age. A multimetric scale to indicate reservoir functional age presents the possibility for management intervention from multiple angles. If a reservoir is functionally aging at an accelerated rate, action may be taken to remedy the conditions contributing most to functional age. Intervention to reduce scores of selected metrics in the scale can potentially reduce the rate of senescence and increase the life expectancy of the reservoir. This leads to the intriguing implication that steps can be taken to reduce functional age and actually make the reservoir grow younger.

  15. Bazhen Fm matured reservoir evaluation (West Siberia, Russia)

    NASA Astrophysics Data System (ADS)

    Parnachev, S.; Skripkin, A.; Baranov, V.; Zakharov, S.

    2015-02-01

    The depletion of the traditional sources of hydrocarbons leads to the situation when the biggest players of the oil and gas production market turn to unconventional reserves. Commercial shale oil and gas production levels in the USA have largely determined world prospects for oil and gas industry development. Russia takes one of the leading place in the world in terms of shale oil resources. The main source rock of the West Siberia, the biggest oil and gas basin in Russia under development, the Bazhen Fm and its stratigraphic and lithologic analogs, is located in the territory of over 1,000,000 square kilometers. Provided it has similar key properties (organic carbon content, porosity, permeability) with the deposits of the Bakken Fm and Green River Fm, USA, it is still extremely poorly described with laboratory methods. We have performed the laboratory analysis of core samples from a well drilled in Bazhen Fm deposits with matured organic matter (Tmax>435 °C). It was demonstrated the applicability of the improved steady-state gas flow method to evaluate the permeability of nanopermeable rocks. The role of natural fracturing in forming voids was determided that allows regarding potential Bazhen Fm reservoirs as systems with dual porosity and dual permeability.

  16. Karst-controlled reservoir heterogeneity in Ellenburger group carbonates of west Texas: Reply

    SciTech Connect

    Kerans, C. )

    1990-07-01

    A reply to a comment made on Kerans' paper (AAGP Bull. 1988) by S.J. Mazzullo is presented. The author takes exception that Mazzullo's contention that he left out important types of hydrocarbon reservoirs in the Permian basin of west Texas and points out that his original intention was to model karst-controlled reservoir rocks only.

  17. Geological control on the reservoir characteristics of Olkaria West Geothermal Field, Kenya

    SciTech Connect

    Omenda, Peter A.

    1994-01-20

    The reservoir of the West Olkaria Geothermal Field is hosted within tuffs and the reservoir fluid is characterized by higher concentrations of reservoir CO{sub 2} (10,000-100,000 mg/kg) but lower chloride concentrations of about 200 mg/kg than the East and North East Fields. The West Field is in the outflow and main recharge area of the Olkaria geothermal system. Permeability is generally low in the West Field and its distribution is strongly controlled by the structures. Fault zones show higher permeability with wells drilled within the structures havin larger total mass outputs. However, N-S and NW-SE faults are mainly channels for cold water downflow into the reservoir. Well feeder zones occur mostly at lava-tuff contacts; within fractured lava flows and at the contacts of intrusives and host rocks.

  18. Nutrient budget for Saguling Reservoir, West Java, Indonesia.

    PubMed

    Hart, Barry T; van Dok, Wendy; Djuangsih, Nani

    2002-04-01

    A preliminary nutrient budget for Saguling Reservoir is reported as a first attempt to quantify the behaviour of nutrients entering this reservoir. This work is part of a larger Indonesia-Australia collaborative research and training project, involving Padjadjaran University and Monash University, established to study nutrient dynamics in Saguling Reservoir. Saguling Reservoir, the first of a chain of three large reservoirs (Saguling, Cirata and Jatilahur), built on the Citarum River in central Java, was completed in 1985. It has already become highly polluted, particularly with domestic and industrial effluent (organic matter, nutrients, heavy metals) from the urban areas of Bandung (population 2 million). The reservoir experiences major water quality problems, including excessive growths of floating plants, toxic cyanobacterial blooms and regular fish-kills. The work reported in this paper shows that Saguling receives a very large nutrient load from the city of Bandung and because of this, is highly eutrophic. It is unlikely that the water quality of Saguling will improve until a substantial part of Bandung is sewered and adequate discharge controls are placed on the many industries in the region upstream of the reservoir.

  19. The aging of America's reservoirs: In-reservoir and downstream physical changes and habitat implications

    USGS Publications Warehouse

    Juracek, Kyle E.

    2015-01-01

    Reservoirs are important for various purposes including flood control, water supply, power generation, and recreation. The aging of America's reservoirs and progressive loss of water storage capacity resulting from ongoing sedimentation, coupled with increasing societal needs, will cause the social, economic, environmental, and political importance of reservoirs to continually increase. The short- and medium-term (<50 years) environmental consequences of reservoir construction and operation are well known and include an altered flow regime, lost connectivity (longitudinal, floodplain), an altered sediment regime, substrate compositional change, and downstream channel degradation. In general, reservoir-related changes have had adverse consequences for the natural ecosystem. Longer term (>50 years) environmental changes as reservoirs enter “old” age are less understood. Additional research is needed to help guide the future management of aging reservoir systems and support the difficult decisions that will have to be made. Important research directions include assessment of climate change effects on aging and determination of ecosystem response to ongoing aging and various management actions that may be taken with the intent of minimizing or reversing the physical effects of aging.

  20. Reservoir characterization of a Permian Giant: Yates Field, West Texas

    SciTech Connect

    Tinker, S.W.; Mruk, D.H.

    1995-06-01

    The Yates Field reservoir characterization project provided the geologic framework, data, and tools that support the ongoing reservoir management of Yates Field. Geologic and engineering data from 1800 wells with digital log data, 23,000 feet of quantified core analysis and description, and six decades of production data, were integrated, analyzed, and displayed in a format which could be used for field evaluation, management, and simulation. The Yates Field reservoir characterization products include: quantified, standardized, digital core descriptions for 118 cores in the field; 2-D digital cross section through every well in the field; 2-D structure and isochore maps for major and internal marker horizons, net and gross reservoir maps, net and gross shale maps, secondary calcite distribution maps, cave distribution maps, and fracture distribution maps; a 6.8 million cell 3-D geologic model of the complete reservoir that includes log, core, and production data. The reservoir characterization project resulted in a quantified description of the heterogeneous matrix and fracture network in Yates Field. It is the efficient, ongoing management of this classic dual-porosity system that has stabilized production from this sixty-eight year old, 4.2 billion barrel field.

  1. Geoscience/engineering characterization of the interwell environment in carbonate reservoirs based on outcrop analogs, Permian Basin, West Texas and New Mexico - petrophysical characterization of the South Cowden Grayburg Reservoir, Ector County, Texas. Final report

    SciTech Connect

    Lucia, F.J.

    1997-06-01

    Reservoir performance of the South Cowden Grayburg field suggests that only 21 percent of the original oil in place has been recovered. The purpose of this study is to construct a realistic reservoir model to be used to predict the location of the remaining mobile oil. Construction of reservoir models for fluid-flow simulation of carbonate reservoirs is difficult because they typically have complicated and unpredictable permeability patterns. Much of the difficulty results from the degree to which diagenetic overprinting masks depositional textures and patterns. For example, the task of constructing a reservoir model of a limestone reservoir that has undergone only cementation and compaction is easier than constructing a model of a karsted reservoir that has undergone cavern formation and collapse as well as cementation and compaction. The Permian-age carbonate-ramp reservoirs in the Permian Basin, West Texas and New Mexico, are typically anhydritic dolomitized limestone. Because the dolomitization occurred soon after deposition, depositional fabrics and patterns are often retained, and a reservoir model can be constructed using depositional concepts. Recent studies of the San Andres outcrop in the Guadalupe Mountains and the Seminole San Andres reservoir in the Permian Basin illustrate how depositional fabrics and patterns can be used to construct a reservoir model when depositional features are retained.

  2. Application of advanced reservoir characterization, simulation and production optimization strategies to maximize recovery in slope and basin clastic reservoirs, West Texas (Delaware Basin). Annual report

    SciTech Connect

    Dutton, S.P.; Asquith, G.B.; Barton, M.D.; Cole, A.G.; Gogas, J.; Malik, M.A.; Clift, S.J.; Guzman, J.I.

    1997-11-01

    The objective of this project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost-effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. This project involves reservoir characterization of two Late Permian slope and basin clastic reservoirs in the Delaware Basin, West Texas, followed by a field demonstration in one of the fields. The fields being investigated are Geraldine Ford and Ford West fields in Reeves and Culberson Counties, Texas. Project objectives are divided into two major phases, reservoir characterization and implementation. The objectives of the reservoir characterization phase of the project were to provide a detailed understanding of the architecture and heterogeneity of the two fields, the Ford Geraldine unit and Ford West field. Reservoir characterization utilized 3-D seismic data, high-resolution sequence stratigraphy, subsurface field studies, outcrop characterization, and other techniques. Once reservoir characterized was completed, a pilot area of approximately 1 mi{sup 2} at the northern end of the Ford Geraldine unit was chosen for reservoir simulation. This report summarizes the results of the second year of reservoir characterization.

  3. Unconformity structures controlling stratigraphic reservoirs in the north-west margin of Junggar basin, North-west China

    NASA Astrophysics Data System (ADS)

    Wu, Kongyou; Paton, Douglas; Zha, Ming

    2013-03-01

    Tectonic movements formed several unconformities in the north-west margin of the Junggar basin. Based on data of outcrop, core, and samples, the unconformity is a structural body whose formation associates with weathering, leaching, and onlap. At the same time, the structural body may be divided into three layers, including upper layer, mid layer, and lower layer. The upper layer with good primary porosity serves as the hydrocarbon migration system, and also accumulates the hydrocarbon. The mid layer with compactness and ductility can play a role as cap rock, the strength of which increases with depth. The lower layer with good secondary porosity due to weathering and leaching can form the stratigraphic truncation traps. A typical stratigraphic reservoir lying in the unconformity between the Jurassic and Triassic in the north-west margin of the Junggar basin was meticulously analyzed in order to reveal the key controlling factors. The results showed that the hydrocarbon distribution in the stratigraphic onlap reservoirs was controlled by the onlap line, the hydrocarbon distribution in the stratigraphic truncation reservoirs was confined by the truncation line, and the mid layer acted as the key sealing rock. So a conclusion was drawn that "two lines (onlap line and truncation line) and a body (unconformity structural body)" control the formation and distribution of stratigraphic reservoirs.

  4. Effects of climate variations and soil conservation on sedimentation of a west-central Oklahoma reservoir

    USDA-ARS?s Scientific Manuscript database

    During the second half of the 20th century, extensive soil conservation practices were implemented on the Fort Cobb Reservoir watershed in West-Central Oklahoma. Sediment and flow observations were made on major tributaries in 1943-1950 (pre-conservation time period), and again in 2004-2008 (post-co...

  5. 3-D Monarch reservoir modelling as a development tool: West Salym field, Western Siberia, Russia

    SciTech Connect

    Ainsworth, R.B.; Van Kuyk, A.; Van Lieshout, J.

    1996-12-31

    The Salym fields are located in the central part of the West Siberia basin. The basin developed during the Triassic and contains an almost complete stratigraphic succession from the Jurassic to the Quaternary. The main oil reserves in the Salym fields are located in the Lower Cretaceous proprading deltaic complex. The principal reservoir section in the West Salym field is interpreted as marginal marine. Shoreface, mouthbar, fluvial channel and crevasse-splay subenvironments are recognised. Due to this range of depositional environments and average (exploration) well spacing of 5 km, 3-D modelling of depositional geometries is essential to determine the reservoir architecture and reservoir property trends prior to full-scale field development.

  6. 3-D Monarch reservoir modelling as a development tool: West Salym field, Western Siberia, Russia

    SciTech Connect

    Ainsworth, R.B.; Van Kuyk, A.; Van Lieshout, J. )

    1996-01-01

    The Salym fields are located in the central part of the West Siberia basin. The basin developed during the Triassic and contains an almost complete stratigraphic succession from the Jurassic to the Quaternary. The main oil reserves in the Salym fields are located in the Lower Cretaceous proprading deltaic complex. The principal reservoir section in the West Salym field is interpreted as marginal marine. Shoreface, mouthbar, fluvial channel and crevasse-splay subenvironments are recognised. Due to this range of depositional environments and average (exploration) well spacing of 5 km, 3-D modelling of depositional geometries is essential to determine the reservoir architecture and reservoir property trends prior to full-scale field development.

  7. Marine radiocarbon reservoir age simulations for the past 50000 years

    NASA Astrophysics Data System (ADS)

    Butzin, Martin; Köhler, Peter; Lohmann, Gerrit

    2016-04-01

    We present simulations of marine radiocarbon reservoir ages using the ocean general circulation model LSG-HAMOCC2s, and evaluate the results with Marine13 raw data records. Our model considers various climatic background states. Radiocarbon cycle boundary conditions are atmospheric Δ14C values according to IntCal13, a recent atmospheric CO2 reconstruction, and spatially variable concentrations of dissolved inorganic carbon derived from marine carbon cycle simulations. Our model reasonably agrees with glacial marine Δ14C records but indicates reservoir ages varying with time, different to the invariant reservoir age corrections applied to the observations and to Marine13. Modelled global-mean reservoir ages are in the range 400-800 years compared to the invariant Marine13 value of 405 years. Self-consistent simulations involving the Cariaco Basin record (which is the most continuous marine record contributing to IntCal13 for periods prior to about 30 kyears) amplify the temporal reservoir age variability with global-mean values of about 350-850 years, and improve the agreement with Δ14C observations in some areas.

  8. Characterization of diagenetically altered carbonate reservoirs, South Cowden Grayburg Reservoir, West Texas

    SciTech Connect

    Lucia, F.J.; Ruppel, S.C.

    1996-12-31

    Much of the difficulty in constructing carbonate reservoir models for fluid-flow simulation results from diagenetic overprinting of depositional permeability patterns. In the South Cowden field, diagenetic effects result in (1) low porosity and permeability in the western and northern areas due to reduction of porosity by means of dolomitization and post-dolomitization compaction, (2) elimination of the petrophysical effects of depositional texture resulting from changes in particle size due to dolomitization, and (3) creation of a touching-vug pore system due to anhydrite dissolution. The extent of anhydrite alteration can be mapped to show three distinct diagenetic areas: those dominated by unaltered, altered, or dissolved anhydrite. Each alteration type has a unique acoustic-porosity transform that can be used to map the diagenetic areas and to calculate porosity when only acoustic logs are available. A single porosity-permeability transform characterizes the areas having unaltered and altered anhydrite, and the depositional stratigraphy is useful in constructing a reservoir model. A more favorable transform characterizes the area of dissolved anhydrite, and depositional stratigraphy is not useful in constructing a reservoir model because of the large effect of the diagenetic overprint.

  9. Environmental Factors Affecting Mercury in Camp Far West Reservoir, California, 2001-03

    USGS Publications Warehouse

    Alpers, Charles N.; Stewart, A. Robin; Saiki, Michael K.; Marvin-DiPasquale, Mark C.; Topping, Brent R.; Rider, Kelly M.; Gallanthine, Steven K.; Kester, Cynthia A.; Rye, Robert O.; Antweiler, Ronald C.; De Wild, John F.

    2008-01-01

    This report documents water quality in Camp Far West Reservoir from October 2001 through August 2003. The reservoir, located at approximately 300 feet above sea level in the foothills of the northwestern Sierra Nevada, California, is a monomictic lake characterized by extreme drawdown in the late summer and fall. Thermal stratification in summer and fall is coupled with anoxic conditions in the hypolimnion. Water-quality sampling was done at approximately 3-month intervals on eight occasions at several stations in the reservoir, including a group of three stations along a flow path in the reservoir: an upstream station in the Bear River arm (principal tributary), a mid-reservoir station in the thalweg (prereservoir river channel), and a station in the deepest part of the reservoir, in the thalweg near Camp Far West Dam. Stations in other tributary arms of the reservoir included those in the Rock Creek arm of the reservoir, a relatively low-flow tributary, and the Dairy Farm arm, a small tributary that receives acidic, metal-rich drainage seasonally from the inactive Dairy Farm Mine, which produced copper, zinc, and gold from underground workings and a surface pit. Several water-quality constituents varied significantly by season at all sampling stations, including major cations and anions, total mercury (filtered and unfiltered samples), nitrogen (ammonia plus organic), and total phosphorus. A strong seasonal signal also was observed for the sulfurisotope composition of aqueous sulfate from filtered water. Although there were some spatial differences in water quality, the seasonal variations were more profound. Concentrations of total mercury (filtered and unfiltered water) were highest during fall and winter; these concentrations decreased at most stations during spring and summer. Anoxic conditions developed in deep parts of the reservoir during summer and fall in association with thermal stratification. The highest concentrations of methylmercury in unfiltered

  10. Small reservoirs in the West African savanna: Usage, monitoring and impact (Invited)

    NASA Astrophysics Data System (ADS)

    Van De Giesen, N.; Liebe, J. R.; Annor, F.; Andreini, M.

    2013-12-01

    The West African savanna is dotted with thousands of small reservoirs. These reservoirs were primarily built for irrigation purposes, supplying supplementary irrigation in the rainy season and full irrigation in the dry season. Some reservoirs were specifically constructed for watering cattle. Most reservoirs, however, now fulfill a multitude of functions in addition to irrigation and cattle watering, such as fishing, bathing, household water, supply of construction materials, and recreation. In the framework of the Small Reservoirs Project (www.smallreservoirs.org), extensive research has been undertaken over the past ten years that addresses the functioning of these reservoirs and the development of new monitoring methods. This presentation will give a general overview of our findings with respect to history, usage, and hydrological impact of small reservoirs in West Africa. In general, no comprehensive databases are available to local and national governments that contain all reservoirs and their attributes. Remote sensing, therefore, offers an interesting alternative to produce inventories of small reservoirs in a cost effective way. The most straightforward application is the mapping of small reservoirs with the aid of optical satellite images. Open water tends to stand out clearly from its surroundings in such images, allowing for relatively accurate determination of the location and surface area of the reservoirs. An important early discovery was that within a given geomorphological region, there is a very good correlation between surface area and storage volume. Once this correlation is established through a small sub-sample of the reservoirs, all volumes can be calculated on the basis of surfaces as determined through remote sensing. In turn, this opens up the opportunity to monitor water storage over the year by means of satellite images. Optical images are usually not available during large parts of the year due to cloud cover. This holds especially true

  11. Origin of reservoir compartmentalization in Lower Ordovician Karstic Dolostones, Ellenburger Group, West Texas

    SciTech Connect

    Kerans, C.

    1988-01-01

    Ellenburger Group reservoirs constitute a major play in the Permian basin of west Texas, with over 1.4 billion bbl cumulative production through 1985. These reservoirs typically have been developed by assuming homogeneous fracture-related pore system. Examination of core, log, and production data demonstrates that most Ellenburger reservoirs are characterized by pronounced vertical and lateral heterogeneities created by post-Ellenburger karst development. Vertical reservoir compartmentalization in the Ellenburger evolved from development of a laterally extensive cave system between 100 and 300 ft beneath the original land surface. Caves were filled by relatively impermeable siliciclastics from the overlying Simpson Group, effectively isolating permeable cave-roof breccias (uppermost Ellenburger) from collapse breccias deposited on cave floors prior to shale infill. Lateral compartmentalization of Ellenburger reservoirs originated by localized collapse of the cave system both during karst formation and after burial. In the Shafter Lake field, lateral compartmentalization is the result of a 200-ft vertical collapse during deposition of Simpson Group sands. Abrupt lateral discontinuities in the Big Lake and Glasco fields may represent similar collapse-related features, such as are spectacularly displayed in Ellenburger-equivalent outcrops of the Franklin Mountains. An estimated 750 million bbl of remaining mobile oil, in addition to conventional reserves, occurs in this mature but complexly compartmentalized play. Considering this paleokarst model will aid in further exploitation of Ellenburger reservoirs.

  12. Assessing sedimentation issues within aging flood-control reservoirs

    USDA-ARS?s Scientific Manuscript database

    Flood control reservoirs designed and built by federal agencies have been extremely effective in reducing the ravages of floods nationwide. Yet some structures are being removed for a variety of reasons, while other structures are aging rapidly and require either rehabilitation or decommissioning. ...

  13. Spatiotemporal associations of reservoir nutrient characteristics and the invasive, harmful alga Prymnesium parvum in West Texas

    USGS Publications Warehouse

    VanLandeghem, Matthew M.; Farooqi, Mukhtar; Southard, Greg M.; Patino, Reynaldo

    2015-01-01

    Golden alga (Prymnesium parvum) is a harmful alga that has caused ecological and economic harm in freshwater and marine systems worldwide. In inland systems of North America, toxic blooms have nearly eliminated fish populations in some systems. Modifying nutrient profiles through alterations to land or water use may be a viable alternative for golden alga control in reservoirs. The main objective of this study was to improve our understanding of the nutrient dynamics that influence golden alga bloom formation and toxicity in west Texas reservoirs. We examined eight sites in the Upper Colorado River basin, Texas: three impacted reservoirs that have experienced repeated golden alga blooms; two reference reservoirs where golden alga is present but nontoxic; and three confluence sites downstream of the impacted and reference sites. Total, inorganic, and organic nitrogen and phosphorus and their ratios were quantified monthly along with golden alga abundance and ichthyotoxicity between December 2010 and July 2011. Blooms persisted for several months at the impacted sites, which were characterized by high organic nitrogen and low inorganic nitrogen. At impacted sites, abundance was positively associated with inorganic phosphorus and bloom termination coincided with increases in inorganic nitrogen and decreases in inorganic phosphorus in late spring. Management of both inorganic and organic forms of nutrients may create conditions in reservoirs unfavorable to golden alga.

  14. Reservoir Characterization around Geothermal Field, West Java, Indonesia Derived from 4-D Seismic Tomography

    NASA Astrophysics Data System (ADS)

    Verdhora Ry, Rexha; Nugraha, A. D.

    2016-01-01

    Observation of micro-seismic events induced by intensive geothermal exploitation in a particular geothermal field, located in West Java region, Indonesia was used to detect the fracture and permeability zone. Using local monitoring seismometer network, tomographic inversions were conducted for the three-dimensional Vp, Vs, and Vp/Vs structure of the reservoir for January - December 2007, January - December 2008, and January - December 2009. First, hypocenters location was relocated using joint hypocenter determination (JHD) method in purpose to estimate best location. Then, seismic tomographic inversions were conducted using delay time tomography for dataset of every year respectively. The travel times passing through the three-dimensional velocity model were calculated using ray tracing pseudo-bending method. Norm and gradient damping were added to constrain blocks without ray and to produce smooth solution model. The inversion algorithm was developed in Matlab environment. Our tomographic inversion results from 3-years of observations indicate the presence of low Vp, low Vs, and low Vp/Vs ratio at depths of about 1 - 3 km below sea level. These features were interpreted may be related to steam-saturated rock in the reservoir area of this geothermal field. The locations of the reservoir area were supported by the data of well- trajectory, where the zones of high Vp/Vs were observed around the injection wells and the zones of low Vp/Vs were observed around the production wells. The extensive low Vp/Vs anomaly that occupies the reservoir is getting stronger during the 3-years study period. This is probably attributed to depletion of pore liquid water in the reservoir and replacement with steam. Continuous monitoring of Vp, Vs, and Vp/Vs is an effective tool for geothermal reservoir characterization and depletion monitoring and can potentially provide information in parts of the reservoir which have not been drilled.

  15. An interdisciplinary approach to reservoir management: The Malu Field, West Niger Delta, Nigeria

    SciTech Connect

    Patterson, B.A.; Bluhm, C.T.; Adokpaye, E.U.

    1995-08-01

    The Malu Field is 175 kilometers southeast of Lagos, offshore Nigeria. The field was discovered in 1967 and brought on stream in 1971. Peak production reached 31,300 barrels per day in 1972. Twenty-six wells have been drilled in the thirty-six square kilometer size field. In 1990 original-oil-in-place was estimated at 345 million barrels with cumulative production of 109 million barrels and an estimated 40 million barrels of remaining reserves. The Main Field review was initiated in 1994 to resolve structural and production inconsistencies and therefore improve reservoir performance. The tools used include reprocessed three-dimensional seismic, oil chemistry (primarily gas chromatography), and production data. The complexly faulted field is subdivided into seven different fault blocks. Growth faults generally trend northwest to southeast and are downthrown to the west. Twenty-five different hydrocarbon-bearing sands have been identified within the field. These sands are separated into sixty-three different reservoirs by the series of southeast trending growth faults. Most sands are laterally continuous within mapped fault blocks except in east Malu. Cross-fault communication of oils occurs among several of the shallow reservoirs in west Malu allowing wells to deplete unintended horizons. In addition, three of the dual string completions are producing oil only from only the upper sands. The integration of seismic, oil chemistry, and production data allows more efficient management of production by providing accurate structure maps, reserve estimates, drainage pathways, and justification for workovers and future development drilling.

  16. Application of Advanced Reservoir Characterization, Simulation, and Production Optimization Strategies to Maximize Recovery in Slope and Basin Clastic Reservoirs, West Texas (Delaware Basin), Class III

    SciTech Connect

    Dutton, Shirley P.; Flanders, William A.

    2001-11-04

    The objective of this Class III project was demonstrate that reservoir characterization and enhanced oil recovery (EOR) by CO2 flood can increase production from slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico. Phase 1 of the project, reservoir characterization, focused on Geraldine Ford and East Ford fields, which are Delaware Mountain Group fields that produce from the upper Bell Canyon Formation (Ramsey sandstone). The demonstration phase of the project was a CO2 flood conducted in East Ford field, which is operated by Orla Petco, Inc., as the East Ford unit.

  17. Karst-controlled reservoir heterogeneity in Ellenburger group carbonates of west Texas: Discussion

    SciTech Connect

    Mazzullo, S.J. )

    1990-07-01

    A discussion is presented on a paper by Charles Kerans (AAPG Bull. 1988). The paper dealt with karst-associated porosity and hydrocarbon reservoir heterogenity in Ellengurger (Lower Ordovician) carbonates in the Permian basin of west Texas. The purpose of this paper is not to dispute the model presented by Kerans, but instead to present some alternative models of reservoir occurrence that are not considered in his paper and that are also widely applicable to the Ellenburger and correlative strata in the Mid-Continent. The discussion is based on regional lithostratigraphy and subsurface mapping studies of the Ellenburger in the southern Midland basin, specifically in Irion, Reagan, Crockett, Schleicher, and Sterling counties (Texas).

  18. Application of advanced reservoir characterization, simulation, and production optimization strategies to maximize recovery in slope and basin clastic reservoirs, West Texas (Delaware Basin). Technical progress report

    SciTech Connect

    Dutton, S.P.

    1996-04-30

    The objective of this project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. Project objectives are divided into two major phases. The objectives of the reservoir characterization phase of the project are to provide a detailed understanding of the architecture and heterogeneity of two fields, the Ford Geraldine unit and Ford West field, which produce from the Bell Canyon and Cherry Canyon Formations, respectively, of the Delaware Mountain Group and to compare Bell Canyon and Cherry Canyon reservoirs. Reservoir characterization will utilize 3-D seismic data, high-resolution sequence stratigraphy, subsurface field studies, outcrop characterization, and other techniques. One the reservoir-characterization study of both field is completed, a pilot area of approximately 1 mi{sup 2} in one of the fields will be chosen for reservoir simulation. The objectives of the implementation phase of the project are to: (1) apply the knowledge gained from reservoir characterization and simulation studies to increase recovery from the pilot area; (2) demonstrate that economically significant unrecovered oil remains in geologically resolvable untapped compartments; and (3) test the accuracy of reservoir characterization and flow simulation as predictive tools in resource preservation of mature fields. A geologically designed, enhanced recovery program (CO{sub 2} flood, waterflood, or polymer flood) and well-completion program will be developed, and one to three infill well will be drilled and cored. Technical progress is summarized for: geophysical characterization; reservoir characterization; outcrop characterization; and producibility problem characterization.

  19. Sediment-water interactions affecting dissolved-mercury distributions in Camp Far West Reservoir, California

    USGS Publications Warehouse

    Kuwabara, James S.; Alpers, Charles N.; Marvin-DiPasquale, Mark; Topping, Brent R.; Carter, James L.; Stewart, A. Robin; Fend, Steven V.; Parcheso, Francis; Moon, Gerald E.; Krabbenhoft, David P.

    2003-01-01

    Field and laboratory studies were conducted in April and November 2002 to provide the first direct measurements of the benthic flux of dissolved (0.2-micrometer filtered) mercury species (total and methylated forms) between the bottom sediment and water column at three sampling locations within Camp Far West Reservoir, California: one near the Bear River inlet to the reservoir, a second at a mid-reservoir site of comparable depth to the inlet site, and the third at the deepest position in the reservoir near the dam (herein referred to as the inlet, midreservoir and near-dam sites, respectively; Background, Fig. 1). Because of interest in the effects of historic hydraulic mining and ore processing in the Sierra Nevada foothills just upstream of the reservoir, dissolved-mercury species and predominant ligands that often control the mercury speciation (represented by dissolved organic carbon, and sulfides) were the solutes of primary interest. Benthic flux, sometimes referred to as internal recycling, represents the transport of dissolved chemical species between the water column and the underlying sediment. Because of the affinity of mercury to adsorb onto particle surfaces and to form insoluble precipitates (particularly with sulfides), the mass transport of mercury in mining-affected watersheds is typically particle dominated. As these enriched particles accumulate at depositional sites such as reservoirs, benthic processes facilitate the repartitioning, transformation, and transport of mercury in dissolved, biologically reactive forms (dissolved methylmercury being the most bioavailable for trophic transfer). These are the forms of mercury examined in this study. In contrast to typical scientific manuscripts, this report is formatted in a pyramid-like structure to serve the needs of diverse groups who may be interested in reviewing or acquiring information at various levels of technical detail (Appendix 1). The report enables quick transitions between the initial

  20. Assessing Sedimentation Issues Within Aging Flood Control Reservoirs in Oklahoma

    NASA Astrophysics Data System (ADS)

    Bennet, Sean J.; Cooper, Charles M.; Ritchie, Jerry C.; Dunbar, John A.; Allen, Peter M.; Caldwell, Larry W.; McGee, Thomas M.

    2002-10-01

    Since 1948, the USDA-NRCS has constructed nearly 11,000 flood control dams across the United States, and many of the reservoirs are rapidly filling with sediment. To rehabilitate these structures, the impounded sediment must be assessed to determine the volume of accumulated sediment and the potential hazard this sediment may pose if reintroduced to the environment. An assessment of sedimentation issues within two reservoirs, Sugar Creek No. 12, Hinton, Oklahoma, and Sergeant Major No. 4, Cheyenne, Oklahoma, is presented. Sediment cores obtained using a vibracoring system were composed of alternating layers of gravel, sand, silt, and clay. Stratigraphic analysis coupled with 137Cs dating techniques enabled the discrimination of pre-construction sediment from post-construction deposition. An acoustic profiling system was unencumbered by the relatively shallow water depth at Sugar Creek No. 12 and the seismic horizons agreed well with the sediment core data. Total sediment volume determined from the acoustic survey and the sediment core data for comparable areas differed by only 1.4 percent. The seismic profiling system worked well in the relatively deeper lake of Sergeant Major No. 4 and showed good correspondence to the collected core data. Detailed chemical analyses showed that overall sediment quality was good at both locations and that chemical composition was spatially invariant. Implementation of these techniques will aid action agencies such as the USDA-NRCS in their assessment and effective management of aging flood control reservoirs.

  1. Reservoir geology and paleoenvironmental reconstruction of Yates Formation, Central Basin Platform, West Texas

    SciTech Connect

    Casavant, R.R.

    1988-01-01

    Computer slice maps and proprietary three-dimensional interactive graphics were used to reconstruct the paleodeposition and to map reservoir variations within the Yates Formation of west Texas. The prolific Yates Formation is a major reservoir in the North Ward Estes field, Ward County, Texas. The Upper Permian (Guadalupian) Yates Formation is an overall regressive shallowing-upward package containing variable sequences of subtidal, intertidal, and supratidal strata. Sediment types include various siliciclastics mixed with sabkha-type carbonates and evaporites. The types of rocks and their structures indicate that these sediments were deposited in a prograding tidal flat-lagoonal setting located behind a shelf margin edge on the western flank of the positive Central Basin platform during the Guadalupian. The cyclic nature of the Yates is largely the result of lagoonal expansion and construction that caused environmental belts on both sides of the lagoon to converge and diverge. These rapid migrations of facies coupled with diagenetic processes created the heterogeneities that characterize this large reservoir.

  2. Accumulation of heavy metals in freshwater fish in cage aquaculture at Cirata Reservoir, West Java, Indonesia.

    PubMed

    Salami, Indah Rachmatiah Siti; Rahmawati, Suphia; Sutarto, Ratri Indri Hapsari; Jaya, Pinilih Marendra

    2008-10-01

    Freshwater fish demand in West Java is supported by cage aquaculture in reservoirs. Cirata Reservoir is one of three cascading hydropower reservoirs built along the Citarum River that receives domestic and industrial wastes. Water pollution by heavy metals, such as copper and lead, increases the health risk of humans who consume the fish. The study was aimed to evaluate the concentration of copper and lead in fish, specifically on Cyprinus carpio, that are widely cultivated in the Cirata Reservoir. Two sizes of fish were collected from five sampling points around floating-cage area. The liver of the fish was found to contain the highest copper level, followed by gills, skin, and muscle. In contrast, lead was also high in the liver, followed by skin, gills, and the muscle, but the copper concentration found in the tissues studied was much higher (31.111 +/- 17.911 mg/kg dry wt) than the lead content (0.290 +/- 0.346 mg/kg dry wt). The concentration of metals in smaller fish was always higher than than that in bigger fish. The metals content was also compared to those in fish exposed in a semistatic laboratory-scale study using Oreochromis niloticus. After 28 days exposure with 0.01 mg Cu/L, fish accumulated 21.53 mg Cu/kg dry wt, whereas for Pb exposure of 0.016 mg/L, fish accumulated up to 7 mg/kg dry wt. However, estimates of Cu and Pb intake from C. carpio consumption were still below the average daily intake (ADI) limit. This study suggested that monitoring of water quality and heavy metals in cultured fish is important in protecting human health.

  3. Application of Advanced Reservoir Characterization, Simulation, and Production Optimization Strategies to Maximize Recovery in Slope and Basin Clastic Reservoirs, West Texas (Delaware Basin), Class III

    SciTech Connect

    Dutton, Shirley P.; Flanders, William A.; Mendez, Daniel L.

    2001-05-08

    The objective of this Class 3 project was demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstone's of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost effective way to recover oil more economically through geologically based field development. This project was focused on East Ford field, a Delaware Mountain Group field that produced from the upper Bell Canyon Formation (Ramsey sandstone). The field, discovered in 9160, is operated by Oral Petco, Inc., as the East Ford unit. A CO2 flood was being conducted in the unit, and this flood is the Phase 2 demonstration for the project.

  4. Application of advanced reservoir characterization, simulation, and production optimization strategies to maximize recovery in slope and basin clastic reservoirs, West Texas (Delaware Basin), Class III

    SciTech Connect

    Dutton, Shirley P.; Flanders, William A.; Zirczy, Helena H.

    2000-05-24

    The objective of this Class 3 project was to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. Phase 1 of the project, reservoir characterization, was completed this year, and Phase 2 began. The project is focused on East Ford field, a representative Delaware Mountain Group field that produces from the upper Bell Canyon Formation (Ramsey sandstone). The field, discovered in 1960, is operated by Oral Petco, Inc., as the East Ford unit. A CO{sub 2} flood is being conducted in the unit, and this flood is the Phase 2 demonstration for the project.

  5. Application of Advanced Reservoir Characterization, Simulation, and Production Optimization Strategies to Maximize Recovery in Slope and Basin Clastic Reservoirs, West Texas (Delaware Basin)

    SciTech Connect

    Dutton, S.P.; Flanders, W.A.; Guzman, J.I.; Zirczy, H.

    1999-06-08

    The objective of this Class III project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost-effective way to recover a higher percentage of the original oil in place through geologically based field development. This year the project focused on reservoir characterization of the East Ford unit, a representative Delaware Mountain Group field that produces from the upper Bell Canyon Formation (Ramsey Sandstone). The field, discovered in 1960, is operated by Orla Petco, Inc., as the East Ford unit; it contained an estimated 19.8 million barrels (MMbbl) of original oil in place. Petrophysical characterization of the East Ford unit was accomplished by integrating core and log data and quantifying petrophysical properties from wireline logs. Most methods of petrophysical analysis that had been developed during an earlier study of the Ford Geraldine unit were successfully transferred to the East Ford unit. The approach that was used to interpret water saturation from resistivity logs, however, had to be modified because in some East Ford wells the log-calculated water saturation was too high and inconsistent with observations made during the actual production. Log-porosity to core-porosity transforms and core-porosity to core-permeability transforms were derived from the East Ford reservoir. The petrophysical data were used to map porosity, permeability, net pay, water saturation, mobil-oil saturation, and other reservoir properties.

  6. Predicting the natural state of fractured carbonate reservoirs: An Andector Field, West Texas test of a 3-D RTM simulator

    SciTech Connect

    Tuncay, K.; Romer, S.; Ortoleva, P.; Hoak, T.; Sundberg, K.

    1998-12-31

    The power of the reaction, transport, mechanical (RTM) modeling approach is that it directly uses the laws of geochemistry and geophysics to extrapolate fracture and other characteristics from the borehole or surface to the reservoir interior. The objectives of this facet of the project were to refine and test the viability of the basin/reservoir forward modeling approach to address fractured reservoir in E and P problems. The study attempts to resolve the following issues: role of fracturing and timing on present day location and characteristics; clarifying the roles and interplay of flexure dynamics, changing rock rheological properties, fluid pressuring and tectonic/thermal histories on present day reservoir location and characteristics; and test the integrated RTM modeling/geological data approach on a carbonate reservoir. Sedimentary, thermal and tectonic data from Andector Field, West Texas, were used as input to the RTM basin/reservoir simulator to predict its preproduction state. The results were compared with data from producing reservoirs to test the RTM modeling approach. The effects of production on the state of the field are discussed in a companion report. The authors draw the following conclusions: RTM modeling is an important new tool in fractured reservoir E and P analysis; the strong coupling of RTM processes and the geometric and tensorial complexity of fluid flow and stresses require the type of fully coupled, 3-D RTM model for fracture analysis as pioneered in this project; flexure analysis cannot predict key aspects of fractured reservoir location and characteristics; fracture history over the lifetime of a basin is required to understand the timing of petroleum expulsion and migration and the retention properties of putative reservoirs.

  7. Changes in the radiocarbon reservoir age in Lake Xingyun, Southwestern China during the Holocene.

    PubMed

    Zhou, Aifeng; He, Yuxin; Wu, Duo; Zhang, Xiaonan; Zhang, Can; Liu, Zhonghui; Yu, Junqing

    2015-01-01

    Chronology is a necessary component of paleoclimatology. Radiocarbon dating plays a central role in determining the ages of geological samples younger than ca. 50 ka BP. However, there are many limitations for its application, including radiocarbon reservoir effects, which may cause incorrect chronology in many lakes. Here we demonstrate temporal changes in the radiocarbon reservoir age of Lake Xingyun, Southwestern China, where radiocarbon ages based on bulk organic matter have been reported in previous studies. Our new radiocarbon ages, determined from terrestrial plant macrofossils suggest that the radiocarbon reservoir age changed from 960 to 2200 years during the last 8500 cal a BP years. These changes to the reservoir effect were associated with inputs from either pre-aged organic carbon or 14C-depleted hard water in Lake Xingyun caused by hydrological change in the lake system. The radiocarbon reservoir age may in return be a good indicator for the carbon source in lake ecosystems and depositional environment.

  8. Changes in the Radiocarbon Reservoir Age in Lake Xingyun, Southwestern China during the Holocene

    PubMed Central

    Zhou, Aifeng; He, Yuxin; Wu, Duo; Zhang, Xiaonan; Zhang, Can; Liu, Zhonghui; Yu, Junqing

    2015-01-01

    Chronology is a necessary component of paleoclimatology. Radiocarbon dating plays a central role in determining the ages of geological samples younger than ca. 50 ka BP. However, there are many limitations for its application, including radiocarbon reservoir effects, which may cause incorrect chronology in many lakes. Here we demonstrate temporal changes in the radiocarbon reservoir age of Lake Xingyun, Southwestern China, where radiocarbon ages based on bulk organic matter have been reported in previous studies. Our new radiocarbon ages, determined from terrestrial plant macrofossils suggest that the radiocarbon reservoir age changed from 960 to 2200 years during the last 8500 cal a BP years. These changes to the reservoir effect were associated with inputs from either pre-aged organic carbon or 14C-depleted hard water in Lake Xingyun caused by hydrological change in the lake system. The radiocarbon reservoir age may in return be a good indicator for the carbon source in lake ecosystems and depositional environment. PMID:25815508

  9. North Atlantic circulation and reservoir age changes over the past 41,000 years

    NASA Astrophysics Data System (ADS)

    Stern, Joseph V.; Lisiecki, Lorraine E.

    2013-07-01

    on the timing of Atlantic meridional overturning circulation (AMOC) changes during the last deglaciation are fundamental to understanding the climate's rapid response to insolation forcing. However, uncertainty about high-latitude North Atlantic (HLNA) radiocarbon reservoir ages has previously precluded robust age model development for this critical region. HLNA reservoir ages also serve as a proxy for AMOC strength. We present regionally averaged HLNA reservoir ages for 0 to 41 thousand years before the present (kyr BP) based on over 500 radiocarbon dates from 33 North Atlantic cores. An early deglacial increase to >1000 14C yr reservoir ages between 18.5 and 16.5 kyr BP suggests reduced AMOC before peak Heinrich Stadial 1 (HS1) ice-rafted debris (IRD). A rapid decrease in reservoir ages coincident with the IRD maximum at 16 kyr BP indicates strong stratification of the upper water column caused by massive freshwater release.

  10. Monitoring Reservoirs Using MERIS And LANDSAT Fused Images : A Case Study Of Polyfitos Reservoir - West Macedonia - Greece

    NASA Astrophysics Data System (ADS)

    Stefouli, M.; Charou, E.; Vasileiou, E.; Stathopoulos, N.; Perrakis, A.

    2012-04-01

    Research and monitoring is essential to assess baseline conditions in reservoirs and their watershed and provide necessary information to guide decision-makers. Erosion and degradation of mountainous areas can lead to gradual aggradation of reservoirs reducing their lifetime. Collected measurements and observations have to be communicated to the managers of the reservoirs so as to achieve a common / comprehensive management of a large watershed and reservoir system. At this point Remote Sensing could help as the remotely sensed data are repeatedly and readily available to the end users. Aliakmon is the longest river in Greece, it's length is about 297 km and the surface of the river basin is 9.210 km2.The flow of the river starts from Northwest of Greece and ends in Thermaikos Gulf. The riverbed is not natural throughout the entire route, because constructed dams restrict water and create artificial lakes, such as lake of Polyfitos, that prevent flooding. This lake is used as reservoir, for covering irrigational water needs and the water is used to produce energy from the hydroelectric plant of Public Power Corporation-PPC. The catchment basin of Polyfitos' reservoir covers an area of 847.76 km2. Soil erosion - degradation in the mountainous watershed of streams of Polyfitos reservoir is taking place. It has been estimated that an annual volume of sediments reaching the reservoir is of the order of 244 m3. Geomatic based techniques are used in processing multiple data of the study area. A data inventory was formulated after the acquisition of topographic maps, compilation of geological and hydro-geological maps, compilation of digital elevation model for the area of interest based on satellite data and available maps. It also includes the acquisition of various hydro-meteorological data when available. On the basis of available maps and satellite data, digital elevation models are used in order to delineate the basic sub-catchments of the Polyfytos basin as well as

  11. Application of Advanced Reservoir Characterization, Simulation, and Production Optimization Strategies to Maximize Recovery in Slope and Basin Clastic Reservoirs, West Texas (Delaware Basin)

    SciTech Connect

    Andrew G. Cole; George B. Asquith; Jose I. Guzman; Mark D. Barton; Mohammad A. Malik; Shirley P. Dutton; Sigrid J. Clift

    1998-04-01

    The objective of this Class III project is to demonstrate that detailed reservoir characterization of clastic reservoirs in basinal sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost-effective way to recover more of the original oil in place by strategic infill-well placement and geologically based enhanced oil recovery. The study focused on the Ford Geraldine unit, which produces from the upper Bell Canyon Formation (Ramsey sandstone). Reservoirs in this and other Delaware Mountain Group fields have low producibility (average recovery <14 percent of the original oil in place) because of a high degree of vertical and lateral heterogeneity caused by depositional processes and post-depositional diagenetic modification. Outcrop analogs were studied to better interpret the depositional processes that formed the reservoirs at the Ford Geraldine unit and to determine the dimensions of reservoir sandstone bodies. Facies relationships and bedding architecture within a single genetic unit exposed in outcrop in Culberson County, Texas, suggest that the sandstones were deposited in a system of channels and levees with attached lobes that initially prograded basinward, aggraded, and then turned around and stepped back toward the shelf. Channel sandstones are 10 to 60 ft thick and 300 to 3,000 ft wide. The flanking levees have a wedge-shaped geometry and are composed of interbedded sandstone and siltstone; thickness varies from 3 to 20 ft and length from several hundred to several thousands of feet. The lobe sandstones are broad lens-shaped bodies; thicknesses range up to 30 ft with aspect ratios (width/thickness) of 100 to 10,000. Lobe sandstones may be interstratified with laminated siltstones.

  12. Improving estimates of surface water radiocarbon reservoir ages in the northeastern Atlantic Ocean.

    NASA Astrophysics Data System (ADS)

    Greenop, Rosanna; Burke, Andrea; Rae, James; Austin, William; Reimer, Paula; Blaauw, Maarten; Crocker, Anya; Chalk, Thomas; Barker, Stephen; Knutz, Paul; Hall, Ian

    2016-04-01

    Radiocarbon measurements from foraminifera in marine sediment cores are widely used to constrain age models and the timing of paleoceanographic events, as well as past changes in ocean circulation and carbon cycling. However, the use of radiocarbon for both dating and palaeoceanographic applications is limited in sediment cores by a lack of knowledge about the surface ocean radiocarbon reservoir age and how it varies in both space and time. Typically, to convert a planktic radiocarbon age into a calendar age, an assumed constant reservoir age is applied. However, there is mounting evidence to suggest that this assumption of constant reservoir age through time is an oversimplification, particularly for the high latitude oceans during the cold climates of the last glacial and deglacial periods. Here we present new high-resolution radiocarbon records together with tephra tie points and 230-thorium (230Th) constrained sedimentation rates to improve estimates of radiocarbon reservoir age in the Northeast Atlantic Ocean. In addition we will explore the impact of the new reservoir ages for both the age models of the cores studied, as well as the palaeoceanographic implications of these reservoir age changes during intervals of rapid climate change over the past 40,000 years.

  13. Mediterranean Sea surface radiocarbon reservoir age changes since the last glacial maximum.

    PubMed

    Siani, G; Paterne, M; Michel, E; Sulpizio, R; Sbrana, A; Arnold, M; Haddad, G

    2001-11-30

    Sea surface reservoir ages must be known to establish a common chronological framework for marine, continental, and cryospheric paleoproxies, and are crucial for understanding ocean-continent climatic relationships and the paleoventilation of the ocean. Radiocarbon dates of planktonic foraminifera and tephra contemporaneously deposited over Mediterranean marine and terrestrial regions reveal that the reservoir ages were similar to the modern one (approximately 400 years) during most of the past 18,000 carbon-14 years. However, reservoir ages increased by a factor of 2 at the beginning of the last deglaciation. This is attributed to changes of the North Atlantic thermohaline circulation during the massive ice discharge event Heinrich 1.

  14. Glacial-Age Dust Provenance in West Antarctica

    NASA Astrophysics Data System (ADS)

    Borunda, A.; Winckler, G.; Goldstein, S. L.; Kaplan, M. R.

    2015-12-01

    Antarctic ice cores contain insoluble dust particles that may have been transported for thousands of miles, from distal continental sources, before being deposited on the ice sheet and incorporated into the ice core record. Knowing the dust sources, and observing how those sources have changed over time, informs our understanding of regional climate conditions in the potential source areas, as well as informing our reconstructions of atmospheric transport between the sources and the poles. Patagonia has been identified as a key dust source to East Antarctica during Ice Age climates; however, the dust sources to West Antarctica during these times have remained unknown. We present radiogenic isotope (Sr, Nd, Pb isotopes) and trace element data of the insoluble dust extracted from 15 WAIS Divide ice core and 4 Byrd ice core samples between ~40ky and the end of the Last Glacial Maximum, and combine these with a novel set of observations on potential sources of dust from around the Pacific sector of the polar Southern Hemisphere. We use these geochemical tools to identify, in a multi-dimensional view, the source(s) of dust to West Antarctica. We also identify the sources of dust across two millennial-scale climate events. The data indicate that Patagonia was a dominant source of dust for West Antarctica during glacial periods, highlighting the importance of southern South America as a dust source for broad swaths of the polar and sub-polar Southern Hemisphere.

  15. Reservoir Characterization of Upper Devonian Gordon Sandstone, Jacksonburg, Stringtown Oil Field, Northwestern West Virginia

    SciTech Connect

    Ameri, S.; Aminian, K.; Avary, K.L.; Bilgesu, H.I.; Hohn, M.E.; McDowell, R.R.; Patchen, D.L.

    2002-05-21

    This report gives results of efforts to determine electrofacies from logs; measure permeability in outcrop to study very fine-scale trends; find the correlation between permeability measured by the minipermeameter and in core plugs, define porosity-permeability flow units; and run the BOAST III reservoir simulator using the flow units defined for the Gordon reservoir.

  16. Late Cretaceous Turbidite Reservoirs Along the Equatorial West African Margin: An Industry Perspective on Source-to-Sink Relationships

    NASA Astrophysics Data System (ADS)

    Wilson, Jonathan; Kohlmann, Fabian; Nicoll, Graeme

    2017-04-01

    The source-to-sink mindset provides an important framework for the exploration geologist. It enables an integrated understanding of hinterland and basin, and can lead to subsurface risk mitigation, particularly with respect to predicting reservoir location and quality. Despite the numerous benefits associated with source-to-sink analysis, such studies are time-consuming to generate, encompassing a large array of disciplines and data, and are not routinely performed within the hydrocarbon industry. The discovery of several significant hydrocarbon fields along the equatorial West African margin has been followed by a series of expensive failures throughout the last decade associated with reservoir quality/presence. This paper discusses a case study focused on the equatorial West African margin, demonstrating how three well-known but effective approaches can be integrated to reconstruct source-to-sink relationships in an ancient sedimentary system, helping de-risk exploration efforts. The first step is to characterize the hinterland. To do this, detailed information was collected for two separate but interlinked datasets—mineral deposits and hard rock geochronology. Combined, these two datasets allow an understanding of the timing and nature of an areas tectonic evolution to be easily developed. The data can be used alongside stratigraphic data and geodynamic information from a plate tectonic model to reconstruct topography and bathymetry of the earth at different episodes of geological time. Paleo digital elevation models (PDEMs) give a first-order approximation of hinterland topography and therefore allow possible sediment source areas to be identified and potential sediment transport pathways to be visualized by means of the digital reconstruction of paleo-drainage networks and their attendant watersheds. This integrated global dataset of hinterland geochronology provides useful "source" information complemented by "sink" information contained within a detrital

  17. Measuring and predicting reservoir heterogeneity in complex deposystems: The fluvial-deltaic Big Injun sandstone in West Virginia

    SciTech Connect

    Patchen, D.G.; Hohn, M.E.; Aminian, K.; Donaldson, A.; Shumaker, R.; Wilson, T.

    1993-04-01

    The purpose of this research is to develop techniques to measure and predict heterogeneities in oil reservoirs that are the products of complex deposystems. The unit chosen for study is the Lower Mississippian Big Injun sandstone, a prolific oil producer (nearly 60 fields) in West Virginia. This research effort has been designed and is being implemented as an integrated effort involving stratigraphy, structural geology, petrology, seismic study, petroleum engineering, modeling and geostatistics. Sandstone bodies are being mapped within their regional depositional systems, and then sandstone bodies are being classified in a scheme of relative heterogeneity to determine heterogeneity across depositional systems. Facies changes are being mapped within given reservoirs, and the environments of deposition responsible for each facies are being interpreted to predict the inherent relative heterogeneity of each facies. Structural variations will be correlated both with production, where the availability of production data will permit, and with variations in geologic and engineering parameters that affect production. A reliable seismic model of the Big Injun reservoirs in Granny Creek field is being developed to help interpret physical heterogeneity in that field. Pore types are being described and related to permeability, fluid flow and diagenesis, and petrographic data are being integrated with facies and depositional environments to develop a technique to use diagenesis as a predictive tool in future reservoir development. Another objective in the Big Injun study is to determine the effect of heterogeneity on fluid flow and efficient hydrocarbon recovery in order to improve reservoir management. Graphical methods will be applied to Big Injun production data and new geostatistical methods will be developed to detect regional trends in heterogeneity.

  18. Measuring and predicting reservoir heterogeneity in complex deposystems. The fluvial-deltaic Big Injun Sandstone in West Virginia. Final report, September 20, 1991--October 31, 1993

    SciTech Connect

    Hohn, M.E.; Patchen, D.G.; Heald, M.; Aminian, K.; Donaldson, A.; Shumaker, R.; Wilson, T.

    1994-05-01

    Non-uniform composition and permeability of a reservoir, commonly referred to as reservoir heterogeneity, is recognized as a major factor in the efficient recovery of oil during primary production and enhanced recovery operations. Heterogeneities are present at various scales and are caused by various factors, including folding and faulting, fractures, diagenesis and depositional environments. Thus, a reservoir consists of a complex flow system, or series of flow systems, dependent on lithology, sandstone genesis, and structural and thermal history. Ultimately, however, fundamental flow units are controlled by the distribution and type of depositional environments. Reservoir heterogeneity is difficult to measure and predict, especially in more complex reservoirs such as fluvial-deltaic sandstones. The Appalachian Oil and Natural Gas Research Consortium (AONGRC), a partnership of Appalachian basin state geological surveys in Kentucky, Ohio, Pennsylvania, and West Virginia, and West Virginia University, studied the Lower Mississippian Big Injun sandstone in West Virginia. The Big Injun research was multidisciplinary and designed to measure and map heterogeneity in existing fields and undrilled areas. The main goal was to develop an understanding of the reservoir sufficient to predict, in a given reservoir, optimum drilling locations versus high-risk locations for infill, outpost, or deeper-pool tests.

  19. Reservoir Characterization of Upper Devonian Gordon Sandstone, Jacksonburg, Stringtown Oil Field, Northwestern West Virginia

    SciTech Connect

    Ameri, S.; Aminian, K.; Avary, K.L.; Bilgesu, H.I.; Hohn, M.E.; McDowell, R.R.; Patchen, D.L.

    2002-05-21

    The purpose of this work was to establish relationships among permeability, geophysical and other data by integrating geologic, geophysical and engineering data into an interdisciplinary quantification of reservoir heterogeneity as it relates to production.

  20. Karst-controlled reservoir heterogeneity in Ellenburger group carbonates of west Texas

    SciTech Connect

    Kerans, C.

    1988-10-01

    Petroleum production from restricted shelf carbonates of the Lower Ordovician Ellenburger group is commonly considered to have been a result of a pervasive, relatively homogeneous tectonic fracture system within the reservoir rock. However, regional facies and diagenetic (paleokarst) studies of Ellenburger strata, based on cores and wireline logs, have demonstrated that significant reservoir compartmentalization was caused by karst modification in the upper part of the unit. 19 figures.

  1. Size of age-0 crappies (Pomoxis spp.) relative to reservoir habitats and water levels

    USGS Publications Warehouse

    Kaczka, Levi J.; Miranda, Leandro E.

    2014-01-01

    Variable year-class strength is common in crappie Pomoxis spp. populations in many reservoirs, yet the mechanisms behind this variability are poorly understood. Size-dependent mortality of age-0 fishes has long been recognized in the population ecology literature; however, investigations about the effects of environmental factors on age-0 crappie size are lacking. The objective of this study was to determine if differences existed in total length of age-0 crappies between embayment and floodplain habitats in reservoirs, while accounting for potential confounding effects of water level and crappie species. To this end, we examined size of age-0 crappies in four flood-control reservoirs in northwest Mississippi over 4years. Age-0 crappies inhabiting uplake floodplain habitats grew to a larger size than fish in downlake embayments, but this trend depended on species, length of time a reservoir was dewatered in the months preceding spawning, and reservoir water level in the months following spawning. The results from our study indicate that water-level management may focus not only on allowing access to quality nursery habitat, but that alternating water levels on a multiyear schedule could increase the quality of degraded littoral habitats.

  2. Holocene reservoir age corrections for the Norwegian Sea based on cold-water corals

    NASA Astrophysics Data System (ADS)

    Andersson Dahl, Carin; Linge, Henriette; Ascough, Philippa; Fietske, Jan; Telford, Richard

    2010-05-01

    There is an offset in 14C age in organisms that lived contemporaneously in the atmosphere relative to those that lived in other carbon reservoirs, such as the ocean. Information about this offset, or reservoir age, R(t), is needed to accurately calibrate marine 14C dates. Although the reservoir age of the ocean is not constant, difficulties in reconstruction the temporal changes in R(t) through time often result in the use of a constant reservoir age correction based on the pre-industrial estimate. This makes detailed comparisons between different archives difficult. Holocene cold-water corals are abundant on the Norwegian shelf and can be dated independently using two different radiometric dating method. The reservoir age correction (?R) of surface ocean waters in the eastern Norwegian Sea was determined for two Holocene periods (9763-9262 and 3097-365 cal. BP) using paired U/Th and AMS 14C dating of nineteen samples of the cold-water coral Lophelia pertusa. Assessment of Holocene ?R values show that early Holocene ?R values are higher compared to the late Holocene. In addition, there also appears to be a trend of increasing ?R values for the past 3000 years BP in the eastern Norwegian Sea. Comparisons to ?R values from the British Isles point towards that there is a latitudinal dependence in ?R in the North Atlantic realm.

  3. Associations between water physicochemistry and Prymnesium parvum presence, abundance, and toxicity in west Texas reservoirs

    USGS Publications Warehouse

    VanLandeghem, Matthew M.; Farooqi, Mukhtar; Southard, Greg M.; Patino, Reynaldo

    2015-01-01

    Toxic blooms of golden alga (Prymnesium parvum) have caused substantial ecological and economic harm in freshwater and marine systems throughout the world. In North America, toxic blooms have impacted freshwater systems including large reservoirs. Management of water chemistry is one proposed option for golden alga control in these systems. The main objective of this study was to assess physicochemical characteristics of water that influence golden alga presence, abundance, and toxicity in the Upper Colorado River basin (UCR) in Texas. The UCR contains reservoirs that have experienced repeated blooms and other reservoirs where golden alga is present but has not been toxic. We quantified golden alga abundance (hemocytometer counts), ichthyotoxicity (bioassay), and water chemistry (surface grab samples) at three impacted reservoirs on the Colorado River; two reference reservoirs on the Concho River; and three sites at the confluence of these rivers. Sampling occurred monthly from January 2010 to July 2011. Impacted sites were characterized by higher specific conductance, calcium and magnesium hardness, and fluoride than reference and confluence sites. At impacted sites, golden alga abundance and toxicity were positively associated with salinity-related variables and blooms peaked at ~10°C and generally did not occur above 20°C. Overall, these findings suggest management of land and water use to reduce hardness or salinity could produce unfavorable conditions for golden alga.

  4. Application of advanced reservoir characterization, simulation, and production optimization strategies to maximize recovery in slope and basin clastic reservoirs, West Texas (Delaware Basin). Quarterly report, April 1,1996 - June 30, 1996

    SciTech Connect

    Dutton, S.P.

    1996-07-01

    The objective of this project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. Project objectives are divided into two major phases. The objectives of the reservoir characterization phase of the project are to provide a detailed understanding of the architecture and heterogeneity of two fields, the Ford Geraldine unit and Ford West field, which produce from the Bell Canyon and Cherry Canyon Formations, respectively, of the Delaware Mountain Group and to compare Bell Canyon and Cherry Canyon reservoirs. Reservoir characterization will utilize 3-D seismic data, high-resolution sequence stratigraphy, subsurface field studies, outcrop characterization, and other techniques. Once the reservoir- characterization study of both fields is completed, a pilot area of approximately 1 mi{sup 2} in one of the fields will be chosen for reservoir simulation. The objectives of the implementation phase of the project are to (1) apply the knowledge gained from reservoir characterization and simulation studies to increase recovery from the pilot area, (2) demonstrate that economically significant unrecovered oil remains in geologically resolvable untapped compartments, and (3) test the accuracy of reservoir characterization and flow simulation as predictive tools in resource preservation of mature fields. A geologically designed, enhanced-recovery program (CO{sub 2} flood, waterflood, or polymer flood) and well-completion program will be developed, and one to three infill wells will be drilled and cored. Progress to date is summarized for reservoir characterization.

  5. Application of advanced reservoir characterization, simulation, and production optimization strategies to maximize recovery in slope and basin clastic reservoirs, West Texas (Delaware Basin). Quarterly report, October 1 - December 31, 1996

    SciTech Connect

    Dutton, S.P.

    1997-01-01

    The objective of this project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. Project objectives are divided into two major phases. The objectives of the reservoir characterization phase of the project are to provide a detailed understanding of the architecture and heterogeneity of two fields, the Ford Geraldine unit and Ford West field, which produce from the Bell Canyon and Cherry Canyon Formations, respectively, of the Delaware Mountain Group and to compare Bell Canyon and Cherry Canyon reservoirs. Reservoir characterization will utilize 3-D seismic data, high-resolution sequence stratigraphy, subsurface field studies, outcrop characterization, and other techniques. Once the reservoir-characterization study of both fields is completed, a pilot area of approximately 1 mi{sup 2} in one of the fields will be chosen for reservoir simulation. The objectives of the implementation phase of the project are to (1) apply the knowledge gained from reservoir characterization and simulation studies to increase recovery from the pilot area, (2) demonstrate that economically significant unrecovered oil remains in geologically resolvable untapped compartments, and (3) test the accuracy of reservoir characterization and flow simulation as predictive tools in resource preservation of mature fields. A geologically designed, enhanced-recovery program (CO{sub 2} flood, waterflood, or polymer flood) and well-completion program will be developed, and one to three infill wells will be drilled and cored. Technical progress is summarized for: geophysical characterization; reservoir characterization; outcrop characterization; and recovery technology identification and analysis.

  6. RESERVOIR CHARACTERIZATION OF UPPER DEVONIAN GORDON SANDSTONE, JACKSONBURG STRINGTOWN OIL FIELD, NORTHWESTERN WEST VIRGINIA

    SciTech Connect

    S. Ameri; K. Aminian; K.L. Avary; H.I. Bilgesu; M.E. Hohn; R.R. McDowell; D.L. Matchen

    2001-07-01

    The Jacksonburg-Stringtown oil field contained an estimated 88,500,000 barrels of oil in place, of which approximately 20,000,000 barrels were produced during primary recovery operations. A gas injection project, initiated in 1934, and a pilot waterflood, begun in 1981, yielded additional production from limited portions of the field. The pilot was successful enough to warrant development of a full-scale waterflood in 1990, involving approximately 8,900 acres in three units, with a target of 1,500 barrels of oil per acre recovery. Historical patterns of drilling and development within the field suggests that the Gordon reservoir is heterogeneous, and that detailed reservoir characterization is necessary for understanding well performance and addressing problems observed by the operators. The purpose of this work is to establish relationships among permeability, geophysical and other data by integrating geologic, geophysical and engineering data into an interdisciplinary quantification of reservoir heterogeneity as it relates to production. Conventional stratigraphic correlation and core description shows that the Gordon sandstone is composed of three parasequences, formed along the Late Devonian shoreline of the Appalachian Basin. The parasequences comprise five lithofacies, of which one includes reservoir sandstones. Pay sandstones were found to have permeabilities in core ranging from 10 to 200 mD, whereas non-pay sandstones have permeabilities ranging from below the level of instrumental detection to 5 mD; Conglomeratic zones could take on the permeability characteristics of enclosing materials, or could exhibit extremely low values in pay sandstone and high values in non-pay or low permeability pay sandstone. Four electrofacies based on a linear combination of density and scaled gamma ray best matched correlations made independently based on visual comparison of geophysical logs. Electrofacies 4 with relatively high permeability (mean value > 45 mD) was

  7. Increased reservoir ages and poorly ventilated deep waters inferred in the glacial Eastern Equatorial Pacific

    PubMed Central

    de la Fuente, Maria; Skinner, Luke; Calvo, Eva; Pelejero, Carles; Cacho, Isabel

    2015-01-01

    Consistent evidence for a poorly ventilated deep Pacific Ocean that could have released its radiocarbon-depleted carbon stock to the atmosphere during the last deglaciation has long been sought. Such evidence remains lacking, in part due to a paucity of surface reservoir age reconstructions required for accurate deep-ocean ventilation age estimates. Here we combine new radiocarbon data from the Eastern Equatorial Pacific (EEP) with chronostratigraphic calendar age constraints to estimate shallow sub-surface reservoir age variability, and thus provide estimates of deep-ocean ventilation ages. Both shallow- and deep-water ventilation ages drop across the last deglaciation, consistent with similar reconstructions from the South Pacific and Southern Ocean. The observed regional fingerprint linking the Southern Ocean and the EEP is consistent with a dominant southern source for EEP thermocline waters and suggests relatively invariant ocean interior transport pathways but significantly reduced air–sea gas exchange in the glacial southern high latitudes. PMID:26137976

  8. Backwaters in the upper reaches of reservoirs produce high densities of age-0 crappies

    USGS Publications Warehouse

    Dagel, Jonah D.; Miranda, Leandro E.

    2012-01-01

    Reservoir backwaters are aquatic habitats in floodplains of reservoir tributaries that are permanently or periodically flooded by the reservoir. Like many reservoir arms, backwaters are commonly shallow, littoral habitats, but they differ from arms in various respects, including their support of primarily wetland plant assemblages that are tolerant to flooding. Elsewhere, the reservoir floods mainly upland plants that are less tolerant to flooding, producing a band of barren shoreline along the fluctuation zone. We investigated differences in relative abundance of age-0 crappies Pomoxis spp. in backwaters and arms of widely fluctuating flood control reservoirs, examined the effect of water level, and estimated the likelihood and timing with which these habitats are flooded annually. Higher catch rates of age-0 crappies were obtained in backwater habitats than in arm habitats. When inundated during the crappie spawning season, backwaters provided vegetated habitat at lower water levels than arms. Backwaters flooded earlier than arms and remained flooded longer to provide prolonged nursery habitat. Whereas vegetated habitat was inundated almost yearly in backwaters and arms, inundation that was timed to the onset of spawning occurred less regularly. Because of differences in water elevation, vegetated habitats were flooded in time for crappie spawning about every other year in backwaters but only every third year in arms. Recruitment of age-0 crappies was inversely correlated with high water levels during the months preceding the spawning period, perhaps because early flooding degraded the vegetation. Our results suggest that water levels may be managed during late winter and spring to regularly flood wetland vegetation communities in backwaters; however, water levels should be maintained at or below normal pool and should only irregularly flood upland vegetation in reservoir arms to promote the preservation of such vegetation. Furthermore, management efforts to

  9. Application of advanced reservoir characterization, simulation, and production optimization strategies to maximize recovery in slope and basin clastic reservoirs, West Texas (Delaware Basin). Quarterly report, July 1 - September 30, 1996

    SciTech Connect

    Dutton, S.P.

    1996-10-01

    The objective of this project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. Project objectives are divided into two major phases. The objectives of the reservoir characterization phase of the project are to provide a detailed understanding of the architecture and heterogeneity of two fields, the Ford Geraldine unit and Ford West field, which produce from the Bell Canyon and Cherry Canyon Formations, respectively, of the Delaware Mountain Group and to compare Bell Canyon and Cherry Canyon reservoirs. Reservoir characterization will utilize 3-D seismic data, high-resolution sequence stratigraphy, subsurface field studies, outcrop characterization, and other techniques. Once the reservoir- characterization study of both fields is completed, a pilot area of approximately 1 mi{sup 2} in one of the fields will be chosen for reservoir simulation. The objectives of the implementation phase of the project are to (1) apply the knowledge gained from reservoir characterization and simulation studies to increase recovery from the pilot area, (2) demonstrate that economically significant unrecovered oil remains in geologically resolvable untapped compartments, and (3) test the accuracy of reservoir characterization and flow simulation as predictive tools in resource preservation of mature fields. A geologically designed, enhanced-recovery program (CO{sup 2} flood, waterflood, or polymer flood) and well-completion program will be developed, and one to three infill wells will be drilled and cored. Accomplishments for this past quarter are discussed.

  10. Modern Tasman Sea surface reservoir ages from deep-sea black corals

    NASA Astrophysics Data System (ADS)

    Komugabe, Aimée F.; Fallon, Stewart J.; Thresher, Ronald E.; Eggins, Stephen M.

    2014-01-01

    Marine reservoir ages are a key element in calculating and constraining uncertainty in radiocarbon age estimates and are also essential to better understand regional ocean circulation. In this study, we present a new method to reconstruct long-term, high-resolution sea surface reservoir ages based on analysis of the organic skeleton of deep-sea (560 m) black coral (Anthozoa, Antipatharia). Our results confirm that antipatharians are extremely slow growing (typical radial growth rate for a South Pacific specimen around 0.03 mm/yr). Coupled uranium series and radiocarbon measurements were made on black coral collected live from the Norfolk Ridge (north Tasman Sea) to provide the first modern reservoir ages for this region. At the Norfolk Ridge, the average reservoir age between 1790 AD and 1900 AD was ∼330 years. This was followed by a steep decrease over time of about 70 years to 1950 AD (our most modern value). This indicates an increase in surface ocean ventilation of water masses in this region. These results are consistent with observational studies for the early twentieth century, which suggest significant changes in regional circulation of the southwest pacific.

  11. Fisheries and Limnological Studies on West Point Reservoir, Alabama-Georgia. Phase V.

    DTIC Science & Technology

    1984-12-01

    Usually blue-green algal communities are dominated by Oscillatoria angustissima in West Point Lake. However, this year a different alga, Spirulina ...different alga, Spirulina laxa, dominated samples at several stations during the summer (Table 7). Chlorophyll 60. Chlorophyll values measured on a volume

  12. Porosity evolution in reservoir sandstones in the West-Central San Joaquin basin, California

    SciTech Connect

    Horton, R.A. Jr.; McCullough, P.T.; Houghton, B.D.; Pennell, D.A.; Dunwoody, J.A. III; Menzie, R.J. Jr.

    1995-04-01

    Miocene reservoir sands (feldspathic and lithic arenites) in central San Joaquin basin oil fields show similar trends in porosity development despite differences in depositional environment, pore-fluid chemistry, and burial history. Burial and tectonic compaction caused grain rotation, deformation of altered lithics, and extensive fracturing of brittle grains, thereby eliminating most primary porosity. Diagenetic fluids, infiltrating along fractures in grains, reacted with freshly exposed mineral surfaces causing extensive leaching of framework components. All major grain types were affected but preferential removal of feldspars and lithics resulted in changes in QFL ratios. With continued compaction angular remnants of partially disolved grains were rotated and rearranged while secondary intergranular and moldic porosity collapsed to form secondary intergranular porosity. This resulted in reservoir sands that are less well sorted, more angular, and mineralogically more mature than they were at deposition. Such changes appear to widespread in the San Joaquin basin and may be more important than is generally acknowledged.

  13. Using Ground-Penetrating Radar to Estimate Sediment Accumulation in a Reservoir: Ball Mountain Dam, West River, Vermont

    NASA Astrophysics Data System (ADS)

    Kasprak, A.; Arcone, S. A.; Dade, W. B.; Finnegan, D. C.; Magilligan, F. J.; Renshaw, C. E.

    2008-12-01

    Numerous dams exist throughout the Upper Connecticut River watershed, having profound effects on regional sediment budgets for the past 50+ years. We use ground-penetrating radar (GPR) to investigate sediment deposition by the West River into an impoundment reservoir located in southern Vermont, with the aim of determining the watershed-scale sediment budget and examining regional denudation rates. The reservoir has a storage capacity of ~104,000,000 cubic meters and was created in 1961 as a consequence of the construction of Ball Mountain Dam in Jamaica, Vermont. A total of 33 GPR reflection profiles were obtained with a 200-MHz radar antenna towed in a raft behind a boat, with 19 additional 100 MHz profiles obtained along exposed shorelines at minimal water level. Preliminary analyses indicate vertical sediment deposition varies greatly based on location; some areas of the impoundment show almost no overlying sediment, while others have received 5 meters of deposition or more. Minimal sediment accumulation is apparent on both the flat bed located along the centerline of the impoundment and on steeply-inclined submerged bedrock faces. Maximum deposition appears to be occurring along shallow-dipping subaqueous slopes near the edges of the reservoir. On-going work includes continued interpretation of GPR records, ground-truthing of those records through sediment coring, and calculation of sediment accumulation rates. In addition to defining the watershed-scale sediment budget over a decadal time scale, results may help guide policy-making regarding the upkeep and potential removal of dams in the region.

  14. Low reservoir ages for the surface ocean from mid-Holocene Florida corals

    USGS Publications Warehouse

    Druffel, E.R.M.; Robinson, L.F.; Griffin, S.; Halley, R.B.; Southon, J.R.; Adkins, J.F.

    2008-01-01

    The 14C reservoir age of the surface ocean was determined for two Holocene periods (4908-4955 and 3008-3066 calendar (cal) B.P.) using U/Th-dated corals from Biscayne National Park, Florida, United States. We found that the average reservoir ages for these two time periods (294 ?? 33 and 291 ?? 27 years, respectively) were lower than the average value between A.D. 1600 and 1900 (390 ?? 60 years) from corals. It appears that the surface ocean was closer to isotopic equilibrium with CO2 in the atmosphere during these two time periods than it was during recent times. Seasonal ??18O measurements from the younger coral are similar to modern values, suggesting that mixing with open ocean waters was indeed occurring during this coral's lifetime. Likely explanations for the lower reservoir age include increased stratification of the surface ocean or increased ??14C values of subsurface waters that mix into the surface. Our results imply that a more correct reservoir age correction for radiocarbon measurements of marine samples in this location from the time periods ???3040 and ???4930 cal years B.P. is ???292 ?? 30 years, less than the canonical value of 404 ?? 20 years. Copyright 2008 by the American Geophysical Union.

  15. Fracture system influence on the reservoirs rock formation of Ordovician-Devonian carbonates in West Siberia tectonic depression

    NASA Astrophysics Data System (ADS)

    Koveshnikov, A. E.; Nesterova, A. C.; Dolgaya, T. F.

    2016-09-01

    During the Paleozoic period from the beginning of the Cambrian to the end of the Carboniferous in the boundaries of the West Siberia tectonic depression there occurred the sea, where the carbonate platforms were formed by the limestones accumulation. All the area at the end of the Carboniferous period was turned to land. Resulting from Gertsynskaya folding in the times of Permian - Triassic the formed deposits were folded and denudated to a considerable extent. Besides, the reservoir rocks of the crust of weathering including redeposited one, were formed as a result of hypergenesis, during the continental stand of the area in the near-surface zone. A new geological prospecting unit has been suggested which underlies these crusts of weathering and formed during fracture tectonic processes with hydrothermal-metasomatic limestones reworking and the processes of hydrothermal leaching and dolomitization. So, in the carbonate platforms the system of fissure zones related to tectonic disturbance was formed. This has a dendrite profile where the series of tangential, more thinned fractures deviate from the stem and finish in pores and caverns. The carbonate platforms formation in the West Siberia tectonic depression has been analyzed, their dynamics and gradual increasing from the minimal in Ordovician and Silurian to maximal at the end of the Late Devonian has been shown.

  16. Fisheries and Limnological Studies on West Point Reservoir, Alabama-Georgia. Phase IV.

    DTIC Science & Technology

    1984-05-01

    is the most important sport fishery on the lake as measured by total directed effort. The striped-white bass hybrid fishery is developing as... develop in West Point Lake during the late summer of 1980. 2. Limnological data collected during the period of 1 October 1979 through 30 September 1980...disappeared from the creel. 15. The striped-white bass hybrid fishery is developing as additional fish are stocked each year by Georgia’s Department of Natural

  17. Numerical simulation of the impacts of water level variation on water age in Dahuofang Reservoir

    NASA Astrophysics Data System (ADS)

    Li, Xinwen; Shen, Yongming

    2015-06-01

    The transport timescales were investigated in response to water level variation under different constant flow rates in Dahuofang Reservoir. The concept of water age was applied to quantify the transport timescales. A three-dimensional hydrodynamic model was developed based on the Environmental Fluid Dynamics Code (EFDC). The model was calibrated for water surface elevation and temperature profiles from April 1, 2008 to October 31, 2008. Comparisons of observed and modeled data showed that the model reproduced the water level fluctuation and thermal stratification during warm season and vertical mixing during cold season fairly well. The calibrated model was then applied to investigate the response of water age to water level changes in Dahuofang Reservoir. Model results showed that water age increases from confluence toward dam zone. In the vertical direction, the water age is relatively uniform at upstream and stratifies further downstream, with a larger value at bottom layer than at surface layer. Comparisons demonstrated that water level variation has a significant impact on transport timescales in the reservoir. The impact of water level drawdown on water age is stronger at bottom layer than at surface layer. Under high flow conditions, the water age decreases 0-20 days at surface layer and 15-25 days at bottom layer. Under mean flow conditions, the water age decreases 20-30 days at surface layer and 30-50 days at bottom layer. Furthermore, the impact is minor in the upstream and increases further downstream. The vertical stratification of water age weakens as the water level decreases. This study provides a numerical tool to quantify the transport timescale in Dahuofang Reservoir and supports adaptive management of regional water resources by local authorities.

  18. Do predators influence the distribution of age-0 kokanee in a Colorado Reservoir?

    USGS Publications Warehouse

    Hardiman, J.M.; Johnson, B.M.; Martinez, P.J.

    2004-01-01

    Seasonal changes in reservoir conditions such as productivity, light, and temperature create spatiotemporal variation in habitat that may segregate or aggregate predators and prey, producing implications for the distribution, growth, and survival of fishes. We used hydroacoustics to document the diel vertical distribution of age-0 kokanee Oncorhynchus nerka relative to environmental gradients at Blue Mesa Reservoir, Colorado, during May-August of 2002. Temperature, light, and zooplankton density profiles were examined relative to foraging conditions for kokanee and their primary predator, lake trout Salvelinus namaycush. Age-0 kokanee displayed large diel vertical migrations in May despite the lack of an energetic advantage before reservoir stratification. Age-0 kokanee minimized near-surface foraging at this time, perhaps to avoid predation by visual predators, such as lake trout, in the well-lit surface waters. Strong reservoir stratification in midsummer appeared to provide a thermal refuge from lake trout that the kokanee exploited. By August vertical migrations were shallow and most kokanee remained in the epilimnion throughout the day. Although the energetic implications of the late-summer strategy are unclear, it appears that kokanee were responding to changes in their predator environment. A robust model for kokanee diel vertical migration across a range of systems should include a predator avoidance component.

  19. Chemical and isotopic heterogeneity in the Yellowstone magma reservoir revealed through sub-crystal-scale zircon age, trace-element, and Hf-isotopic analyses

    NASA Astrophysics Data System (ADS)

    Stelten, M. E.; Cooper, K. M.; Vazquez, J. A.; Barfod, G. H.; Yin, Q.; Wimpenny, J.

    2012-12-01

    The Yellowstone Plateau (USA) hosts one of the largest Quaternary magmatic systems in the world, with caldera forming eruptions at ~2.1 Ma, ~1.3 Ma, and ~0.64 Ma, as well as numerous intracaldera and extracaldera eruptions between caldera-forming events. The most recent eruptive episode at Yellowstone caldera produced the intracaldera Central Plateau Member (CPM) of the Plateau Rhyolite, which erupted intermittently between ~170-70 ka with a cumulative volume ≥600 km3, approaching the volume of rhyolite erupted during the caldera-forming eruptions. Thus, the CPM rhyolites provide snapshots of a large silicic magmatic system though time. In this study we examine the degree of compositional heterogeneity in the Yellowstone magma reservoir by comparing SHRIMP age, SHRIMP trace element, and LA-MC-ICPMS Hf-isotopic data for zircons hosted in five CPM rhyolites. The CPM rhyolites included in this study are: 1) the Solfatara Plateau flow (SPF) and Hayden Valley flow (HVF), which erupted ca. 103 ka from the east side of Yellowstone caldera, 2) the West Yellowstone flow (WYF), which erupted ca. 114 ka from the west side of the caldera, and 3) the Pitchstone Plateau flow (PPF) and Grants Pass flow (GPF), which erupted from the west side of the caldera ca. 75 ka. Linking the age, trace-element, and Hf-isotopic compositions of zones within individual zircons provides a robust method for recognizing distinct crystal populations within the CPM rhyolites and tracking the chemical evolution of the magma reservoir through time. Comparing crystal populations in coeval rhyolites erupted from different parts of the caldera allows for assessment of whether the entire reservoir hosts similar crystal populations at a given time and thus provides insight into the degree of compositional heterogeneity within the magma reservoir. Zircons hosted in the SPF, HVF, and WYF have cores with ages that vary from near eruption age to 200 ka and display a wide range in trace-element and Hf

  20. Age, carbon content and climatic stability of West Siberian peatlands

    NASA Astrophysics Data System (ADS)

    MacDonald, G.; Frey, K. E.; Sheng, Y.; Peugh, S.; Velichko, A.; Kremenetski, K.; Borisova, O.; Forster, R. R.

    2001-12-01

    The West Siberian Lowland (WSL) is the world's largest high-latitude wetland, with a 1.8 X 106 km2 forest-palustrine zone covering nearly 2/3 of western Siberia. Over half of this area consists of peatlands, which since the early Holocene have sequestered atmospheric carbon in the form of undecomposed plant matter. The total carbon pool of the WSL has been roughly estimated at ~215 Pg C, suggesting that nearly one-tenth of the world's soil carbon pool lies stored in these peatlands. The region has recently attracted attention from the global change community, owing to recent studies elsewhere that suggest CO2 and methane exchange from peatlands may change dramatically under a warming climate. Since 1999 an international team of scientists from UCLA, The Russian Academy of Sciences, Tomsk State University and the University of Utah, has conducted a major field and satellite remote sensing study of the role of WSL peatlands in the global carbon cycle. Central to the study is the extraction of peat cores throughout the region, from which peatland age and carbon content are determined from thermal analysis and radiocarbon dating. After successful summer field campaigns in 1999, 2000 and 2001 we have collected nearly 100 cores, as well as thousands of other measurements and samples of peat depth, surface moisture, botany, water geochemistry, river sediment load and land surface cover. The scope and scale of these data are unprecedented in the region. Numerous satellite images of the area have also been compiled, including 150 m MSU-SK visible/near-infrared imagery from the Russian RESURS-01 platform since 1994, ERS synthetic aperture radar and scatterometer products since 1991, DMSP SSM/I passive microwave data since 1987, and 52 Landsat MSS scenes acquired in 1973. These satellite datasets are now being combined with point field observations to determine the Holocene evolution, total carbon content, desiccation susceptibility and contemporary wetness variability of the

  1. 14C Marine Reservoir Age 14.2 to 12.8 kyr cal BP

    NASA Astrophysics Data System (ADS)

    Kromer, B.; Friedrich, M.; Hughen, K. A.; Kaiser, F. K.

    2001-12-01

    We constructed several floating pine tree-ring chronologies from sites in Eastern and Southern Germany, Switzerland and Northern Italy, dated by 14C to the Late Glacial [Friedrich et al., 2001]. While still floating they cannot be used to determine the magnitude of the marine 14C reservoir age, but as the tree-ring time scale is annual, decadal 14C analyses of these chronologies allow to check if the 14C reservoir age of the tropical warm pool was constant in time, by comparing high-precision (+- 25 yr) tree-ring based 14C series to the high-resolution marine 14C data set obtained from the Cariaco basin [Hughen et al., 2000]. For the time interval between 14.2 and 13.2 k cal BP the marine reservoir age appears to have been essentially constant, with variations of 100 yr or less. Furthermore, a hemisphere-wide cooling event (G1d in the GRIP ice core, grey-scale minimum in the Cariaco varves) is seen, within the 14C time window defined by the Cariaco data set and our tree-ring 14C analyses, to occur as a drastic growth reduction in the European tree-ring sections. Using this event as an anchor, we can determine the magnitude of the marine reservoir age over the common time interval. Between 14.2 and 13.9 k our tree-ring based 14C data confirm the value of ca. 420 yr marine reservoir age. However, during the final two centuries prior to the YD the marine reservoir age of the tropical warm pool increases to ca. 600 yr. Based on carbon cycle models we discuss the implications of our findings in terms of solar and oceanic forcing of the radiocarbon budgets. Friedrich, M., B. Kromer, K.F. Kaiser, M. Spurk, K.A. Hughen, and S.J. Johnsen, High resolution climate signals in the Boelling/Alleroed Interstadial as reflected in European tree-ring chronologies compared to marine varves and ice-core records., Quaternary Science Reviews, Vol. 20 (11), 1223-1232, 2001. Hughen, K.A., J.R. Southon, S.J. Lehman, and J.T. Overpeck, Synchronous Radiocarbon and Climate Shifts During the

  2. Aging Reservoirs in a Changing Climate: Examining Storage Loss of Large Reservoirs and Variability of Sedimentation Rate in a Dominant Cropland Region

    NASA Astrophysics Data System (ADS)

    Rahmani, V.; Kastens, J.; deNoyelles, F.; Huggins, D.; Martinko, E.

    2015-12-01

    Dam construction has multiple environmental and hydrological consequences including impacts on upstream and downstream ecosystems, water chemistry, and streamflow. Behind the dam the reservoir can trap sediment from the stream and fill over time. With increasing population and drinking and irrigation water demands, particularly in the areas that have highly variable weather and extended drought periods such as the United States Great Plains, reservoir sedimentation escalates water management concerns. Under nearly all projected climate change scenarios we expect that reservoir water storage and management will come under intense scrutiny because of the extensive use of interstate river compacts in the Great Plains. In the state of Kansas, located in the Great Plains, bathymetric surveys have been completed during the last decade for many major lakes by the Kansas Biological Survey, Kansas Water Office, and the U.S. Army Corps of Engineers. In this paper, we studied the spatial and temporal changes of reservoir characteristics including sedimentation yield, depletion rate, and storage capacity loss for 24 federally-operated reservoirs in Kansas. These reservoirs have an average age of about 50 years and collectively have lost approximately 15% of their original capacity, with the highest annual observed single-reservoir depletion rate of 0.84% and sedimentation yield of 1,685 m3 km-2 yr-1.

  3. Regional and economic geology of Pennsylvanian age coal beds of West Virginia

    USGS Publications Warehouse

    Repine, T.E.; Blake, B.M.; Ashton, K.C.; Fedorko, N.; Keiser, A.F.; Loud, E.I.; Smith, C.J.; McClelland, S.W.; McColloch, G.H.

    1993-01-01

    West Virginia is the only place in the United States where an entire section of Pennsylvanian age (Upper Carboniferous) strata can be seen. These strata occur within a wedge of rock that thins to the north and west from the southeastern part of the State. The progressive north-northwesterly termination of older Pennsylvanian geologic units beneath younger ones prominently outlines the center of the Appalachian basin of West Virginia. Over most of West Virginia, Lower and/or Middle Pennsylvanian strata unconformably overly Upper Mississippian (Lower Carboniferous) strata. Sediment deposition was accomplished by a complex system of deltas prograding north and west from an eastern and southeastern source area. More than 100 named coal beds occur within the Lower, Middle, and Upper Pennsylvanian rocks of West Virginia and at least 60 of these have been or are currently being mined commercially. Collectively, these coal beds account for original in-ground coal resources of almost 106.1??109 t (117??109 tons). West Virginia ranks fourth in the United States in demonstrated coal reserves. In 1988, West Virginia produced 131.4??106 t (144.9??106 T) of coal, third highest in the United States. Of this annual production, 75% was from underground mines. In 1988, West Virginia led the nation in the number of longwall mining sections currently in place. West Virginia's low-volatile coal beds are known worldwide as important metallurgical-grade coals, while the higher-volatile coal beds are utilized primarily for steam production. ?? 1993.

  4. Transit times and age distributions for reservoir models represented as nonlinear non-autonomuous systems

    NASA Astrophysics Data System (ADS)

    Müller, Markus; Meztler, Holger; Glatt, Anna; Sierra, Carlos

    2016-04-01

    We present theoretical methods to compute dynamic residence and transit time distributions for non-autonomous systems of pools governed by coupled nonlinear differential equations. Although transit time and age distributions have been used to describe reservoir models for a long time, a closer look to their assumptions reveals two major restrictions of generality in previous studies. First, the systems are assumed to be in equilibrium; and second, the equations under consideration are assumed to be linear. While both these assumptions greatly ease the computation and interpretation of transit time and age distributions they are not applicable to a wide range of problems. Moreover, the transfer of previous results learned from linear systems in steady state to the more complex nonlinear non-autonomous systems that do not even need to have equilibria, can be dangerously misleading. Fortunately the topic of time dependent age and transit time distributions has received some attention recently in hydrology, we aim to compute these distributions for systems of multiple reservoirs. We will discuss how storage selection functions can augment the information represented in an ODE system describing a system of reservoirs. We will present analytical and numerical algorithms and a Monte Carlo simulator to compute solutions for system transit time and age distributions for system-wide storage selection functions including the most simple, but important case of well mixed pools.

  5. Stromatolite laminae (Lagoa Vermelha, Brasil) as archives for reservoir age changes

    NASA Astrophysics Data System (ADS)

    Bruggmann, Sylvie; Vasconcelos, Crisogono; Hajdas, Irka

    2016-04-01

    As laminated biogenic or abiogenic sedimentary structures [1], stromatolites record environmental changes along growth profiles, revealing possible changes in reservoir ages due to input of older carbon. A modern stromatolite sample was collected in Lagoa Vermelha (100 km east of Rio de Janeiro, Brasil) an area known for upwelling of South Atlantic Central Water (SACW). 34 samples from a transect cutting the lamination were collected with a hand-driller for standard geochemistry and 14C AMS analyses. Shells collected in 2015 were analysed for estimation of the present-day reservoir age. 14C ages of laminae and the reservoir age were used to apply the age-depth model to the stromatolite transect with the OxCal depositional model (Marine13 calibration curve; [2]). Small-scale changes in the composition of laminae report environmental changes, e.g. upwelling. The well-laminated middle part (laminated boundstone; ca. 4cm) of the stromatolite transect was found to have grown in a short time period of less than 100 years (1163-1210 14C y BP), with four excursions towards older 14C ages (ca. 1200 14C y BP). To detect possible changes of marine 14C, calendar years assuming a stable modern reservoir age were used to simulate atmospheric 14C ages with the southern hemisphere IntCal13 atmospheric calibration curve [3]. The offset between the measured and simulated 14C ages indicates a variability of the reservoir age between -99 and 268 14C y with highest reservoir correction found for the layers with indication of environmental changes (e.g. upwelling). Thus, this simulation confirms the occurrence of older carbon and points out the sensitivity of stromatolites for changing reservoir ages. [1] M.A. Semikhatov, C.D. Gebelein, P. Cloud, S.M. Awramik, W.C. Benmore (1979). Stromatolite morphogenesis - progress and problems. Canadian Journal of Earth Sciences, 19:992-1015. [2] P.J. Reimer, E. Bard, A. Bayliss, J. W. Beck, P. G. Blackwell, C. Bronk Ramsey, C. E. Buck, H. Cheng, R

  6. Predicting the downstream impact of ensembles of small reservoirs with special reference to the Volta Basin, West Africa

    NASA Astrophysics Data System (ADS)

    van de Giesen, N.; Andreini, M.; Liebe, J.; Steenhuis, T.; Huber-Lee, A.

    2005-12-01

    After a strong reduction in investments in water infrastructure in Sub-Saharan Africa, we now see a revival and increased interest to start water-related projects. The global political willingness to work towards the UN millennium goals are an important driver behind this recent development. Large scale irrigation projects, such as were constructed at tremendous costs in the 1970's and early 1980's, are no longer seen as the way forward. Instead, the construction of a large number of small, village-level irrigation schemes is thought to be a more effective way to improve food production. Such small schemes would fit better in existing and functioning governance structures. An important question now becomes what the cumulative (downstream) impact is of a large number of small irrigation projects, especially when they threaten to deplete transboundary water resources. The Volta Basin in West Africa is a transboundary river catchment, divided over six countries. Of these six countries, upstream Burkina Faso and downstream Ghana are the most important and cover 43% and 42% of the basin, respectively. In Burkina Faso (and also North Ghana), small reservoirs and associated irrigation schemes are already an important means to improve the livelihoods of the rural population. In fact, over two thousand such schemes have already been constructed in Burkina Faso and further construction is to be expected in the light of the UN millennium goals. The cumulative impact of these schemes would affect the Akosombo Reservoir, one of the largest manmade lakes in the world and an important motor behind the economic development in (South) Ghana. This presentation will put forward an analytical framework that allows for the impact assessment of (large) ensembles of small reservoirs. It will be shown that despite their relatively low water use efficiencies, the overall impact remains low compared to the impact of large dams. The tools developed can be used in similar settings elsewhere

  7. Origin of micro-rhombic calcite matrix within Cretaceous reservoir rock, West Stuart City Trend, Texas

    NASA Astrophysics Data System (ADS)

    Perkins, Ronald D.

    1989-07-01

    Cores from four wells from the West Stuart City Trend in La Salle and Webb Counties, Texas, were analyzed to define depositional and diagenetic facies and to determine factors controlling porosity distribution. In all, 1187 ft (362 m) of core and 220 thin sections were examined in detail and supplemented by SEM analyses of fractured surfaces and plastic casts of pore systems. A comparison of lithofacies and ecologic facies to permeability and porosity values compiled from core data revealed that zones with permeabilities greater than 0.1 md and porosities of at least 6% were associated with rudistid grainstones cemented by isopachous, submarine cement and packstones with a finely crystalline rhombic calcite matrix. Isotopic and trace element analyses of both isopachous submarine cements and micro-rhombic matrix suggest a common origin. The precursor to the micro-rhombic calcite is believed to have been peloidal, high-magnesian calcite. This internal marine sediment may be analogous to the peloidal fabrics that have been reported from Holocene and Pleistocene carbonates. Diagenetic equilibration of both submarine cements and peloidal infill is believed to have occurred during burial either in marine pore waters at elevated temperatures or in restricted flow, phreatic freshwaters.

  8. [Some notes on methods of age estimation: an attempt in a Sundanese village, West Java].

    PubMed

    Igarashi, T

    1982-09-01

    This study is concerned with the problem of age misstatement in Indonesia. The author first presents an analysis of age data that were collected directly from the population of a Sundanese village in West Java and that indicate the extent of the problem. Various approaches used to estimate age and the problems associated with their use are then described. (summary in ENG)

  9. Fracture characterization and discrimination criteria for karst and tectonic fractures in the Ellenburger Group, West Texas: Implications for reservoir and exploration models

    SciTech Connect

    Hoak, T.E. |; Sundberg, K.R.; Deyhim, P.; Ortoleva, P.

    1998-12-31

    In the Ellenburger Group fractured dolomite reservoirs of West Texas, it is extremely difficult to distinguish between multiple phases of karst-related fracturing, modifications to the karst system during burial, and overprinting tectonic fractures. From the analyses of drill core, the authors developed criteria to distinguish between karst and tectonic fractures. In addition, they have applied these criteria within the context of a detailed diagenetic cement history that allows them to further refine the fracture genesis and chronology. In these analyses, the authors evaluated the relationships between fracture intensity, morphologic attributes, host lithology, fracture cement, and oil-staining. From this analysis, they have been able to characterize variations in Ellenburger tectonic fracture intensity by separating these fractures from karst-related features. In general, the majority of fracturing in the Ellenburger is caused by karst-related fracturing although a considerable percentage is caused by tectonism. These findings underscore the importance of considering the complete geologic evolution of a karst reservoir during exploration and field development programs. The authors have been able to more precisely define the spatial significance of the fracture data sets by use of oriented core from Andector Field. They have also demonstrated the importance of these results for exploration and reservoir development programs in West Texas, and the potential to extrapolate these results around the globe. Given the historic interest in the large hydrocarbon reserves in West Texas carbonate reservoirs, results of this study will have tremendous implications for exploration and production strategies targeting vuggy, fractured carbonate systems not only in West Texas, but throughout the globe.

  10. Application of advanced reservoir characterization, simulation, and production optimization strategies to maximize recovery in slope and basin clastic reservoirs, west Texas (Delaware Basin). Annual progress report, March 31, 1995--March 31, 1996

    SciTech Connect

    Dutton, S.P.; Hovorka, S.D.; Cole, A.G.

    1996-08-01

    The objective of this Class III project is to demonstrate that detailed reservoir characterization of clastic reservoirs in basinal sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost-effective way to recover more of the original oil in place by strategic infill-well placement and geologically based field development. Reservoirs in the Delaware Mountain Group have low producibility (average recovery <14 percent of the original oil in place) because of a high degree of vertical and lateral heterogeneity caused by depositional processes and post-depositional diagenetic modification. Detailed correlations of the Ramsey sandstone reservoirs in Geraldine Ford field suggest that lateral sandstone continuity is less than interpreted by previous studies. The degree of lateral heterogeneity in the reservoir sandstones suggests that they were deposited by eolian-derived turbidites. According to the eolian-derived turbidite model, sand dunes migrated across the exposed shelf to the shelf break during sea-level lowstands and provided well sorted sand for turbidity currents or grain flows into the deep basin.

  11. Investigating the influence of regional climate and oceanography on marine radiocarbon reservoir ages in southwest New Zealand

    NASA Astrophysics Data System (ADS)

    Hinojosa, Jessica L.; Moy, Christopher M.; Prior, Christine A.; Eglinton, Timothy I.; McIntyre, Cameron P.; Stirling, Claudine H.; Wilson, Gary S.

    2015-12-01

    The New Zealand fjords are located at a latitude where distinct oceanic and atmospheric fronts separate carbon reservoirs of varying residence time. The marine radiocarbon reservoir age in this region is likely to deviate from the global average reservoir age over space and time as frontal boundaries migrate north and south. Here we present new estimates of modern radiocarbon reservoir age using the radiocarbon content of bivalve shells collected live before 1950. Multiple measurements from hydrographically distinct sites support the use of a ΔR, defined as the regional offset between measured and modeled marine radiocarbon reservoir age, of 59 ± 35 years for the New Zealand fjords. We also assess the radiocarbon content of bulk surface sediments throughout the fjord region. Sediment with a higher proportion of marine organic carbon has relatively less radiocarbon than more terrestrial sediment, suggesting a short residence time of organic carbon on land before deposition in the fjords. Additionally, we constrain reservoir age variability throughout the Holocene using coeval terrestrial and marine macrofossils. Although our modern results suggest spatial consistency in ΔR throughout the fjords, large deviations from the global average marine radiocarbon reservoir age exist in the paleo record. We find four ancient ΔR values, extending back to ˜10.2 cal kyr BP, to be negative or near zero. A likely cause of younger radiocarbon reservoir ages at select intervals throughout the Holocene is the increased influence of the Southern Hemisphere westerly winds, which cause extreme precipitation in the region that delivers terrestrial carbon, enriched in radiocarbon, to fjord basins. However, bivalve depth habitat may also influence radiocarbon content due to a stratified water column containing distinct carbon pools. This work highlights the need for thorough assessment of local radiocarbon cycling in similar regions of dynamic ocean/atmosphere frontal zones

  12. Deep Pacific ventilation ages during the last deglaciation: Evaluating the influence of diffusive mixing and source region reservoir age

    NASA Astrophysics Data System (ADS)

    Lund, David C.

    2013-11-01

    Enhanced ventilation of the deep ocean during the last deglaciation may have caused the rise in atmospheric carbon dioxide that drove Earth's climate from a glacial to interglacial state. Recent results based on the projection age method, however, suggest the ventilation rate of the deep Pacific slowed during the deglaciation, opposite the expected pattern (Lund et al., 2011). Because the projection age method does not account for tracer diffusion (Adkins and Boyle, 1997) it can yield spurious results and therefore requires validation with alternative techniques. Here ventilation ages are determined using the transit-time equilibration-time distribution (TTD-ETD) method which explicitly accounts for diffusive mixing in the ocean interior (DeVries and Primeau, 2010). The overall time history of deep Pacific TTD-ETD and projection ages is very similar; both show a 1000-yr increase in ventilation age during Heinrich Stadial 1 (HS1; 14.5-17.5 kyr BP) and a 500-yr increase during the Younger Dryas (YD). The similarity is due in part to the use of projection age error estimates that take into account uncertainty in both calendar age and benthic 14C age. Centennial-scale offsets between the TTD-ETD and projection ages are due primarily to the different approaches used to estimate surface ocean radiocarbon content. Both the TTD-ETD and projection age results imply that the ventilation rate of the deep Pacific decreased during the deglaciation, opposite the pattern expected if Southern Ocean upwelling and enhanced meridional overturning drove outgassing of CO2 from the abyss. Variations in surface water reservoir age could cause an apparent shift in deep Pacific ventilation age but existing proxy records from the Southern Ocean appear to be inconsistent with such a driver.

  13. Centuries of marine radiocarbon reservoir age variation within archaeological Mesodesma Donacium shells from Southern Peru

    USGS Publications Warehouse

    Jones, K.B.; Hodgins, G.W.L.; Etayo-Cadavid, M. F.; Andrus, C.F.T.; Sandweiss, D.H.

    2010-01-01

    Mollusk shells provide brief (<5 yr per shell) records of past marine conditions, including marine radiocarbon reservoir age (R) and upwelling. We report 21 14C ages and R calculations on small (~2 mg) samples from 2 Mesodesma donacium (surf clam) shells. These shells were excavated from a semi-subterranean house floor stratum 14C dated to 7625 ?? 35 BP at site QJ-280, Quebrada Jaguay, southern Peru. The ranges in marine 14C ages (and thus R) from the 2 shells are 530 and 170 14C yr; R from individual aragonite samples spans 130 ?? 60 to 730 ?? 170 14C yr. This intrashell 14C variability suggests that 14C dating of small (time-slice much less than 1 yr) marine samples from a variable-R (i.e. variable-upwelling) environment may introduce centuries of chronometric uncertainty. ?? 2010 by the Arizona Board of Regents on behalf of the University of Arizona.

  14. From the pore scale to reservoir scale: Lithohydraulic flow unit characterization of a shallow shelf carbonate reservoir, North Robertson Unit, West Texas

    SciTech Connect

    Vessell, R.K.; Davies, D.K. )

    1996-01-01

    This paper presents the results of integrated geological-petrophysical reservoir characterization performed as part of the US Department of Energy Class II reservoir program. Petrographic image analysis, using a specially equipped SEM, allowed for the identification of 8 petrophysical rock types at the North Robertson Unit. Detailed log analysis resulted in the development of algorithms for the log-based identification of these rock types in 109 wells. Porosity was related to permeability for each Rock Type: thus permeability is determined from well log data. Evaluation of porosity, permeability, Sw and HPV distribution has allowed for the identification of 12 lithohydraulic flow units. These flow units have been mapped across the unit. The technique allows for the development of log-based reservoir models that are simulator-ready. The results of this study have application to all heterogeneous, shallow shelf carbonate reservoirs, they demonstrate that large fields can be successfully characterized using few cores and emphasize the importance of integrated geological-engineering analysis in reservoir characterization.

  15. From the pore scale to reservoir scale: Lithohydraulic flow unit characterization of a shallow shelf carbonate reservoir, North Robertson Unit, West Texas

    SciTech Connect

    Vessell, R.K.; Davies, D.K.

    1996-12-31

    This paper presents the results of integrated geological-petrophysical reservoir characterization performed as part of the US Department of Energy Class II reservoir program. Petrographic image analysis, using a specially equipped SEM, allowed for the identification of 8 petrophysical rock types at the North Robertson Unit. Detailed log analysis resulted in the development of algorithms for the log-based identification of these rock types in 109 wells. Porosity was related to permeability for each Rock Type: thus permeability is determined from well log data. Evaluation of porosity, permeability, Sw and HPV distribution has allowed for the identification of 12 lithohydraulic flow units. These flow units have been mapped across the unit. The technique allows for the development of log-based reservoir models that are simulator-ready. The results of this study have application to all heterogeneous, shallow shelf carbonate reservoirs, they demonstrate that large fields can be successfully characterized using few cores and emphasize the importance of integrated geological-engineering analysis in reservoir characterization.

  16. Marine radiocarbon reservoir age simulations for the past 50,000 years

    NASA Astrophysics Data System (ADS)

    Butzin, M.; Köhler, P.; Lohmann, G.

    2017-08-01

    Radiocarbon (14C) dating calibration for the last glacial period largely relies on cross-dated marine 14C records. However, marine reservoirs are isotopically depleted with respect to the atmosphere and therefore have to be corrected by the Marine Radiocarbon Ages of surface waters (MRAs), whose temporal variabilities are largely unknown. Here we present simulations of the spatial and temporal variability in MRAs using a three-dimensional ocean circulation model covering the past 50,000 years. Our simulations are compared to reconstructions of past surface ocean Δ14C. Running the model with different climatic boundary conditions, we find that low-latitude to midlatitude MRAs have varied between 400 and 1200 14C years, with values of about 780 14C years at the Last Glacial Maximum. Reservoir ages exceeding 2000 14C years are simulated in the polar oceans. Our simulation results can be used as first-order approximation of the MRA variability in future radiocarbon calibration efforts.

  17. Spatial distribution of Hydrocarbon Reservoirs in the West Korea Bay Basin in the northern part of the Yellow Sea, estimated by 3D gravity forward modeling

    NASA Astrophysics Data System (ADS)

    Choi, Sungchan; Ryu, In-Chang; Götze, H.-J.; Chae, Y.

    2016-10-01

    Although an amount of hydrocarbon has been discovered in the West Korea Bay Basin (WKBB), located in the North Korean offshore area, geophysical investigations associated with these hydrocarbon reservoirs are not permitted because of the current geopolitical situation. Interpretation of satellite- derived potential field data can be alternatively used to image the three-dimensional (3D) density distribution in the sedimentary basin associated with hydrocarbon deposits. We interpreted the TRIDENT satellite-derived gravity field data to provide detailed insights into the spatial distribution of sedimentary density structures in the WKBB. We used 3D forward density modeling for the interpretation that incorporated constraints from existing geological and geophysical information. The gravity data interpretation and the 3D forward modeling showed that there are two modeled areas in the central subbasin that are characterized by very low density structures, with a maximum density of about 2000 kg/m3, indicating some type of hydrocarbon reservoir. One of the anticipated hydrocarbon reservoirs is located in the southern part of the central subbasin with a volume of about 250 km3 at a depth of about 3000 m in the Cretaceous/Jurassic layer. The other hydrocarbon reservoir should exist in the northern part of the central subbasin, with an average volume of about 300 km3 at a depth of about 2500 m.

  18. Spatial distribution of hydrocarbon reservoirs in the West Korea Bay Basin in the northern part of the Yellow Sea, estimated by 3-D gravity forward modelling

    NASA Astrophysics Data System (ADS)

    Choi, Sungchan; Ryu, In-Chang; Götze, H.-J.; Chae, Y.

    2017-01-01

    Although an amount of hydrocarbon has been discovered in the West Korea Bay Basin (WKBB), located in the North Korean offshore area, geophysical investigations associated with these hydrocarbon reservoirs are not permitted because of the current geopolitical situation. Interpretation of satellite-derived potential field data can be alternatively used to image the 3-D density distribution in the sedimentary basin associated with hydrocarbon deposits. We interpreted the TRIDENT satellite-derived gravity field data to provide detailed insights into the spatial distribution of sedimentary density structures in the WKBB. We used 3-D forward density modelling for the interpretation that incorporated constraints from existing geological and geophysical information. The gravity data interpretation and the 3-D forward modelling showed that there are two modelled areas in the central subbasin that are characterized by very low density structures, with a maximum density of about 2000 kg m-3, indicating some type of hydrocarbon reservoir. One of the anticipated hydrocarbon reservoirs is located in the southern part of the central subbasin with a volume of about 250 km3 at a depth of about 3000 m in the Cretaceous/Jurassic layer. The other hydrocarbon reservoir should exist in the northern part of the central subbasin, with an average volume of about 300 km3 at a depth of about 2500 m.

  19. Copper avoidance and mortality of juvenile brown trout (Salmo trutta) in tests with copper-sulfate-treated water from West Branch Reservoir, Putnam County, New York

    USGS Publications Warehouse

    Baldigo, Barry P.; Baudanza, T.P.

    2001-01-01

    Copper-avoidance tests and acute-toxicity (mortality) tests on hatchery-reared, young-of- the-year brown trout (salmo trutta) were conducted with water from West Branch Reservoir to assess the avoidance response to copper sulfate treatment, which is used occasionally by New York City Department of Environmental Protection to decrease phytoplankton populations in the reservoir. Avoidance-test results indicate that juvenile brown trout tend to avoid dissolved copper concentrations greater than about 55 ?g/L (micrograms per liter), which is the approximate avoidance-response threshold. The mean net avoidance response of brown trout to dissolved copper concentrations of 70 and 100 ?g/L, and possibly 80 ?g/L, was significantly different (at a = 0.1) from the mean net avoidance response of fish to control (untreated) water and to treated water at most other tested concentrations. Mortality-test results indicate that the 96-hr median lethal concentration (LC50) of dissolved copper was 61.5 ?g/L. All (100 percent) of the brown trout died at a dissolved copper concentration of 85 ?g/L, many died at concentrations of 62 ?g/L and 70 ?g/L, and none died in the control waters (7 ?g/L) or at concentrations of 10, 20, or 45 ?g/L. The estimated concentration of dissolved copper that caused fish mortality (threshold) was 53.5 ?g/L, virtually equivalent to the avoidance-response threshold. Additional factors that could affect the copper-avoidance and mortality response of individual brown trout and their populations in West Branch Reservoir include seasonal variations in certain water-quality parameters, copper-treatment regimes, natural fish distributions during treatment, and increased tolerance due to acclimation. These warrant additional study before the findings from this study can be used to predict the effects that copper sulfate treatments have on resident fish populations in New York City reservoirs.

  20. Age and Educational Selectivity among Migration and Human Capital Flows in the West.

    ERIC Educational Resources Information Center

    Evenson, James A.

    This paper quantifies and analyzes the total flows of human capital moving in and out of the West over time as a result of interregional migration. Particular emphasis is placed on analyzing the "age-education" interaction effect of migration on flows of human capital. Migration was highly selective of the young and/or highly educated…

  1. Age structure and expansion of pinon-juniper woodlands: a regional perspective in the Intermountain West

    Treesearch

    Richard F. Miller; Robin J. Tausch; E. Durant McArthur; Dustin D. Johnson; Stewart C. Sanderson

    2008-01-01

    Numerous studies have documented the expansion of woodlands in the Intermountain West; however, few have compared the chronology of expansion for woodlands across different geographic regions or determined the mix and extent of presettlement stands. We evaluated tree age structure and establishment for six woodlands in four ecological provinces in the central and...

  2. Determination of radiocarbon reservoir age of Lake Van by mineral magnetic and geochemical analysis

    NASA Astrophysics Data System (ADS)

    Makaroglu, Ozlem; Namik Cagatay, M.; Pesonen, Lauri J.; Orbay, Naci

    2017-04-01

    Lake Van is the largest soda lake in the world, located on the east Anatolian Plateau in Turkey. Its varved sediments provide an excellent archive of high-resolution paleoclimate record for the Near East. Varve counting and radiocarbon methods are therefore important dating techniques for investigating the Lake Van sedimentary paleoclimate record. In here we present detailed magnetic and geochemical record of Lake Van. We have studied 4.56 m (core VP0801) and 4.70 m (core VP0807) long cores recovered from 80 m and 65 m water depths located in SE and SW of Lake Van, respectively. Here, we have benefited from magnetic properties with associated remanent magnetization of the sediments from Lake Van to correlate the cores which contain of tephra layers. The cores cover the last 8.4 ka and lithologically include three laminated sedimentary units. From top to the bottom, the units were dated 4.2 ka BP-present, 5.4-4.2 ka BP and older than 5.4 ka BP. We identified tephra layers previously dated by varve counting, and used the varve ages to obtain age models for the cores. We also obtained a total of eight Accelerator Mass Spectrometry (AMS) 14C dates from total organic carbon (TOC) in the two cores, close to the tephra layers. Comparison of the varve ages of the AMS 14C dated samples with their corresponding AMS 14C dates indicates large differences, suggesting significant reservoir ages that range from 2.8 to 2.5 ka for 3.0-2.4 varve ka BP and from 2.8 to 3.3 ka for 8.0-5.9 varve ka BP. The results suggest that the reservoir age of the organic matter increases with the varve age of the sediments. This increase is mainly related to the rate of supply of "dead" carbon from the old carbonate rocks in the watershed of Lake Van, which was relatively higher during 8.4-5.9 ka than during 3.0-2.4 ka BP because of the higher atmospheric precipitation and higher rate of biochemical weathering during the former period.

  3. Age structure and mortality of walleyes in Kansas reservoirs: Use of mortality caps to establish realistic management objectives

    USGS Publications Warehouse

    Quist, M.C.; Stephen, J.L.; Guy, C.S.; Schultz, R.D.

    2004-01-01

    Age structure, total annual mortality, and mortality caps (maximum mortality thresholds established by managers) were investigated for walleye Sander vitreus (formerly Stizostedion vitreum) populations sampled from eight Kansas reservoirs during 1991-1999. We assessed age structure by examining the relative frequency of different ages in the population; total annual mortality of age-2 and older walleyes was estimated by use of a weighted catch curve. To evaluate the utility of mortality caps, we modeled threshold values of mortality by varying growth rates and management objectives. Estimated mortality thresholds were then compared with observed growth and mortality rates. The maximum age of walleyes varied from 5 to 11 years across reservoirs. Age structure was dominated (???72%) by walleyes age 3 and younger in all reservoirs, corresponding to ages that were not yet vulnerable to harvest. Total annual mortality rates varied from 40.7% to 59.5% across reservoirs and averaged 51.1% overall (SE = 2.3). Analysis of mortality caps indicated that a management objective of 500 mm for the mean length of walleyes harvested by anglers was realistic for all reservoirs with a 457-mm minimum length limit but not for those with a 381-mm minimum length limit. For a 500-mm mean length objective to be realized for reservoirs with a 381-mm length limit, managers must either reduce mortality rates (e.g., through restrictive harvest regulations) or increase growth of walleyes. When the assumed objective was to maintain the mean length of harvested walleyes at current levels, the observed annual mortality rates were below the mortality cap for all reservoirs except one. Mortality caps also provided insight on management objectives expressed in terms of proportional stock density (PSD). Results indicated that a PSD objective of 20-40 was realistic for most reservoirs. This study provides important walleye mortality information that can be used for monitoring or for inclusion into

  4. Geoscience/engineering characterization of the interwell environment in carbonate reservoirs based on outcrop analogs, Permian Basin, West Texas and New Mexico--waterflood performance analysis for the South Cowden Grayburg Reservoir, Ector County, Texas. Final report

    SciTech Connect

    Jennings, J.W. Jr.

    1997-05-01

    A reservoir engineering study was conducted of waterflood performance in the South Cowden field, an Upper Permian Grayburg reservoir on the Central Basin Platform in West Texas. The study was undertaken to understand the historically poor waterflood performance, evaluate three techniques for incorporating petrophysical measurements and geological interpretation into heterogeneous reservoir models, and identify issues in heterogeneity modeling and fluid-flow scaleup that require further research. The approach included analysis of relative permeability data, analysis of injection and production data, heterogeneity modeling, and waterflood simulation. The poor South Cowden waterflood recovery is due, in part, to completion of wells in only the top half of the formation. Recompletion of wells through the entire formation is estimated to improve recovery in ten years by 6 percent of the original oil in place in some areas of the field. A direct three-dimensional stochastic approach to heterogeneity modeling produced the best fit to waterflood performance and injectivity, but a more conventional model based on smooth mapping of layer-averaged properties was almost as good. The results reaffirm the importance of large-scale heterogeneities in waterflood modeling but demonstrate only a slight advantage for stochastic modeling at this scale. All the flow simulations required a reduction to the measured whole-core k{sub v}/k{sub h} to explain waterflood behavior, suggesting the presence of barriers to vertical flow not explicitly accounted for in any of the heterogeneity models. They also required modifications to the measured steady-state relative permeabilities, suggesting the importance of small-scale heterogeneities and scaleup. Vertical flow barriers, small-scale heterogeneity modeling, and relative permeability scaleup require additional research for waterflood performance prediction in reservoirs like South Cowden.

  5. MULTIDISCIPLINARY IMAGING OF ROCK PROPERTIES IN CARBONATE RESERVOIRS FOR FLOW-UNIT TARGETING

    SciTech Connect

    Stephen C. Ruppel

    2005-02-01

    Despite declining production rates, existing reservoirs in the US contain large quantities of remaining oil and gas that constitute a huge target for improved diagnosis and imaging of reservoir properties. The resource target is especially large in carbonate reservoirs, where conventional data and methodologies are normally insufficient to resolve critical scales of reservoir heterogeneity. The objectives of the research described in this report were to develop and test such methodologies for improved imaging, measurement, modeling, and prediction of reservoir properties in carbonate hydrocarbon reservoirs. The focus of the study is the Permian-age Fullerton Clear Fork reservoir of the Permian Basin of West Texas. This reservoir is an especially appropriate choice considering (a) the Permian Basin is the largest oil-bearing basin in the US, and (b) as a play, Clear Fork reservoirs have exhibited the lowest recovery efficiencies of all carbonate reservoirs in the Permian Basin.

  6. Large spatial variations in coastal 14C reservoir age - a case study from the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Lougheed, B. C.; Filipsson, H. L.; Snowball, I.

    2013-05-01

    Coastal locations are highly influenced by input from freshwater river runoff, including sources of terrestrial carbon, which can be expected to modify the 14C reservoir age, or R (t), associated with marine water. In this Baltic Sea case study, pre-bomb museum collection mollusc shells of known calendar age, from 30 locations across a strategic salinity transect of the Baltic Sea, were analysed for 14C, δ13C and δ18O. R (t) was calculated for all 30 locations. Seven locations, of which six are within close proximity of the coast, were found to have relatively higher R (t) values, indicative of hard-water effects. Whenever possible, the Macoma genus of mollusc was selected from the museum collections, in order to exclude species specific reservoir age effects as much as possible. When the Macoma samples are exclusively considered, and samples from hard-water locations excluded, a statistically significant correlation between Macoma R (t) and average salinity is found, indicating a two end-member linear mixing model between 14Cmarine and 14Crunoff. A map of Baltic Sea Macoma aragonite R (t) for the late 19th and early 20th centuries is produced. Such a map can provide an estimate for contemporary Baltic Sea Macoma R (t), although one must exercise caution when applying such estimates back in time or to 14C dates obtained from different sample material. A statistically significant correlation is found between δ18Oaragonite and Macoma R (t), suggesting that δ18Oaragonite can be used to estimate Macoma palaeo-R (t), due to the δ18Oaragonite signal being dominated by the salinity gradient of the Baltic Sea. A slightly increased correlation can be expected when δ18Oaragonite is corrected for temperature fractionation effects. The results of this Baltic Sea case study, which show that R (t) is affected by hydrographic conditions and local carbon inputs, have important consequences for other coastal and estuarine locations, where R (t) is also likely to significantly

  7. Relation of Chlorofluorocarbon Ground-Water Age Dates to Water Quality in Aquifers of West Virginia

    USGS Publications Warehouse

    ,; Kurt, J.; Kozar, Mark D.

    2007-01-01

    The average apparent age of ground water in fractured-bedrock aquifers in West Virginia was determined using chlorofluorocarbon (CFC) dating methods. Since the introduction of CFC gases as refrigerants in the late 1930s, atmospheric concentrations have increased until production ceased in the mid-1990s. CFC dating methods are based on production records that date to the early 1940s, and the preservation of atmospheric CFC concentrations in ground water at the time of recharge. As part of the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) and Ambient Ground-Water Monitoring Network (AGN) programs in West Virginia from 1997 to 2005, 80 samples from the Appalachian Plateaus Physiographic Province, 27 samples from the Valley and Ridge Physiographic Province, and 5 samples from the Ohio River alluvial aquifers were collected to estimate ground-water ages in aquifers of West Virginia. Apparent CFC ages of water samples from West Virginia aquifers ranged from 5.8 to 56 years. In the Appalachian Plateaus, topographically driven ground-water flow is evident from apparent ages of water samples from hilltop, hillside, and valley settings (median apparent ages of 12, 14, and 25 years, respectively). Topographic setting was the only factor that was found to be related to apparent ground-water age in the Plateaus at the scale of this study. Similar relations were not found in Valley and Ridge aquifers, indicating that other factors such as bedding or geologic structure may serve larger roles in controlling ground-water flow in that physiographic province. Degradation of CFCs was common in samples collected from methanogenic/anoxic aquifers in the Appalachian Plateaus and suboxic to anoxic aquifers in the Valley and Ridge. CFC contamination was most common in Ohio River alluvial aquifers and carbonate units of the Valley and Ridge, indicating that these highly transmissive surficial aquifers are the most vulnerable to water-quality degradation and may

  8. [Age and growth of Oreochromis aureus (Pisces: Cichlidae) in Sanalona Reservoir, Sinaloa, Mexico].

    PubMed

    Beltrán-Alvarez, Rigoberto; Sánchez-Palacios, Jesús; Valdez, Guadalupe L; Ortega-Salas, Armando A

    2010-03-01

    Oreochromis aureus is an important fishing resource in this reservoir but little biological information is available for management purposes. To study its age and growth in the site, we obtained samples using gill nets of six mesh sizes, and collecting fish from commercial catches, on a bimonthly basis, from November 2006 to September 2007. Total length (Lt), total weight (Pt), sex and gonadosomatic maturity were analyzed. Age determination was done by readings of scale growth marks, and its validation was made by the marginal and gonadosomatic index. A total of 384 fish were collected. Length and weight varied from 125 to 345 mm and from 40 to 671 g, respectively. Growth in length and weight are described by the following von Bertalanffy equations: Lt=416 [1-e(-0.3682)(t+0.4975)] and Pt=1323 [1-e(-0.3682(t+0.4975)](3.0652). Two growth marks per year were registered, these were associated to metabolic and environmental factors like reproduction and temperature.

  9. The west-wide ponderosa pine levels-of-growing-stock study at age 40

    Treesearch

    William W. Oliver

    2005-01-01

    In the 1960s a series of levels-of-growing-stock studies was established in young, even-aged stands throughout the range of ponderosa pine in the western United States. Using a common study plan, installations were begun in the Black Hills of South Dakota, eastern and central Oregon, the Coconino Plateau of Arizona and the west slope of the Sierra Nevada in California...

  10. West Virginia Adolescents' Health Risk Behaviors: Differences by Gender, Age, Grade Level, and Level of Rurality.

    ERIC Educational Resources Information Center

    Meehan, Merrill L.; And Others

    In 1990, the Youth Risk Behavior Survey (YRBS) was completed by a random sample of 1,448 West Virginia public-school students in grades 9-12. The sample was 51 percent male and 89 percent white. About 71 percent of subjects were aged 15-17; 39 percent were in the ninth grade. The YRBS covered behaviors producing vehicle-related or other injuries,…

  11. South side of reservoir with buildings 20 and 21 in ...

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

    South side of reservoir with buildings 20 and 21 in background - Fitzsimons General Hospital, Water Reservoir, West Bushnell Avenue, South side, 150 feet West of intersection of West Bushnell Avenue & South First Street, Aurora, Adams County, CO

  12. Roof of reservoir from southeast corner with buildings 20 and ...

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

    Roof of reservoir from southeast corner with buildings 20 and 21 in background - Fitzsimons General Hospital, Water Reservoir, West Bushnell Avenue, South side, 150 feet West of intersection of West Bushnell Avenue & South First Street, Aurora, Adams County, CO

  13. Age at Virologic Control Influences Peripheral Blood HIV Reservoir Size and Serostatus in Perinatally-Infected Adolescents

    PubMed Central

    Persaud, Deborah; Patel, Kunjal; Karalius, Brad; Rainwater-Lovett, Kaitlin; Ziemniak, Carrie; Ellis, Angela; Chen, Ya Hui; Richman, Douglas; Siberry, George K.; Van Dyke, Russell B.; Burchett, Sandra; Seage, George R.; Luzuriaga, Katherine

    2014-01-01

    Importance Combination antiretroviral therapy (cART) initiated within several weeks of HIV infection in adults limits proviral reservoirs that preclude HIV cure. Biomarkers of restricted proviral reservoirs may aid in the monitoring of HIV remission or cure. Objectives To quantify peripheral blood proviral reservoir size in perinatally HIV-infected adolescents and to identify correlates of limited proviral reservoirs. Design, Setting, and Participants A cross-sectional study including 144 perinatally HIV-infected (PHIV+) youth (median age: 14.3 years), enrolled in the US-based Pediatric HIV/AIDS Cohort Study, on durable (median: 10.2 years) cART, stratified by age at virologic control. Main Outcome and Measures The primary endpoint was peripheral blood mononuclear cell (PBMC) proviral load following virologic control at different ages. Correlations between proviral load and markers of active HIV production (HIV-specific antibodies, 2-long terminal repeat (2-LTR) circles), and markers of immune activation and inflammation were also assessed. Results Proviral reservoir size was markedly reduced in the PHIV+ youth who achieved virologic control by age 1 year (4.2 [interquartile range, 2.6-8 6] copies per 1 million PBMCs) compared to those who achieved virologic control between 1-5 years of age (19.4 [interquartile range, 5.5-99.8] copies per 1 million PBMCs) or after age 5 years (−(70.7 [interquartile range, 23.2-209.4] copies per 1 million PBMCs; P < .00l). A proviral burden <10 copies/million PBMCs was measured in 11 (79%), 20 (40%), and 13 (18%) participants with virologic control at ages <1 year, 1-5 years, and >5 years, respectively (p<0.001). Lower proviral load was associated with undetectable 2-LTR circles (p<0.001) and HIV negative or indeterminate serostatus (p<0.001), but not with concentrations of soluble immune activation markers CD14 and CD163. Conclusions and Relevance Early effective cART along with prolonged virologic suppression after perinatal HIV

  14. Copper avoidance and mortality of juvenile brown trout (Salmo trutta) in tests with copper-sulfate-treated water from West Branch Reservoir, Putnam County, New York

    USGS Publications Warehouse

    Baldigo, Barry P.; Baudanza, T.P.

    2001-01-01

    Copper-avoidance tests and acute-toxicity (mortality) tests on hatchery-reared, young-of- the-year brown trout (salmo trutta) were conducted with water from West Branch Reservoir to assess the avoidance response to copper sulfate treatment, which is used occasionally by New York City Department of Environmental Protection to decrease phytoplankton populations in the reservoir. Avoidance-test results indicate that juvenile brown trout tend to avoid dissolved copper concentrations greater than about 55 μg/L (micrograms per liter), which is the approximate avoidance-response threshold. The mean net avoidance response of brown trout to dissolved copper concentrations of 70 and 100 μg/L, and possibly 80 μg/L, was significantly different (at α= 0.1) from the mean net avoidance response of fish to control (untreated) water and to treated water at most other tested concentrations. Mortality-test results indicate that the 96-hr median lethal concentration (LC50) of dissolved copper was 61.5 μg/L. All (100 percent) of the brown trout died at a dissolved copper concentration of 85 μg/L, many died at concentrations of 62 μg/L and 70 μg/L, and none died in the control waters (7 μg/L) or at concentrations of 10, 20, or 45 μg/L. The estimated concentration of dissolved copper that caused fish mortality (threshold) was 53.5 μg/L, virtually equivalent to the avoidance-response threshold.Additional factors that could affect the copper-avoidance and mortality response of individual brown trout and their populations in West Branch Reservoir include seasonal variations in certain water-quality parameters, copper-treatment regimes, natural fish distributions during treatment, and increased tolerance due to acclimation. These warrant additional study before the findings from this study can be used to predict the effects that copper sulfate treatments have on resident fish populations in New York City reservoirs.

  15. Sm-Nd age of the Fiskenaesset Anorthosite Complex, West Greenland

    NASA Technical Reports Server (NTRS)

    Ashwal, Lewis D.; Goldstein, Steven J.; Jacobsen, Stein B.; Myers, John S.; Kalsbeek, Feiko

    1989-01-01

    A Sm-Nd isotopic study on samples from the Fiskenaesset Anorthosite Complex in West Greenland was conducted to estimate the age of crystallization of the complex. A five-point isochron, including data for whole-rock samples of anorthosite, metagabbro, metaperidotite, and separates of calcic plagioclase and mafic matrix from a coarse megacrystic leucogabbro, corresponds to an age of 2.86 + or - 0.05 Ga, with initial sigma(Nd) of +2.9 + or - 0.4. This implies a relatively short time interval, on the order of 70 Ma, during which anorthosite formation, tonalite emplacement, and high-grade metamorphism took place.

  16. Exploring the Spatio-Temporal Dynamics of Reservoir Hosts, Vectors, and Human Hosts of West Nile Virus: A Review of the Recent Literature

    PubMed Central

    Ozdenerol, Esra; Taff, Gregory N.; Akkus, Cem

    2013-01-01

    Over the last two decades West Nile Virus (WNV) has been responsible for significant disease outbreaks in humans and animals in many parts of the World. Its extremely rapid global diffusion argues for a better understanding of its geographic extent. The purpose of this inquiry was to explore spatio-temporal patterns of WNV using geospatial technologies to study populations of the reservoir hosts, vectors, and human hosts, in addition to the spatio-temporal interactions among these populations. Review of the recent literature on spatial WNV disease risk modeling led to the conclusion that numerous environmental factors might be critical for its dissemination. New Geographic Information Systems (GIS)-based studies are monitoring occurrence at the macro-level, and helping pinpoint areas of occurrence at the micro-level, where geographically-targeted, species-specific control measures are sometimes taken and more sophisticated methods of surveillance have been used. PMID:24284356

  17. Exploring the spatio-temporal dynamics of reservoir hosts, vectors, and human hosts of West Nile virus: a review of the recent literature.

    PubMed

    Ozdenerol, Esra; Taff, Gregory N; Akkus, Cem

    2013-10-25

    Over the last two decades West Nile Virus (WNV) has been responsible for significant disease outbreaks in humans and animals in many parts of the World. Its extremely rapid global diffusion argues for a better understanding of its geographic extent. The purpose of this inquiry was to explore spatio-temporal patterns of WNV using geospatial technologies to study populations of the reservoir hosts, vectors, and human hosts, in addition to the spatio-temporal interactions among these populations. Review of the recent literature on spatial WNV disease risk modeling led to the conclusion that numerous environmental factors might be critical for its dissemination. New Geographic Information Systems (GIS)-based studies are monitoring occurrence at the macro-level, and helping pinpoint areas of occurrence at the micro-level, where geographically-targeted, species-specific control measures are sometimes taken and more sophisticated methods of surveillance have been used.

  18. Geological aspects of drilling horizontal wells in steam flood reservoirs, west side, southern San Joaquin Valley, California

    SciTech Connect

    Crough, D.D.; Holman, M.L.; Sande, J.J. )

    1994-04-01

    Shell Western E P Inc. has drilled 11 horizontal wells in four mature steam floods in the Coalinga, South Belridge, and Midway-Sunset fields. Two medium radius wells are producing from the Pliocene Etchegoin Formation in Coalinga. One medium radius well is producing from the Pleistocene Tulare Formation in South Belridge field. Three short radius and five medium radius wells are producing from the upper Miocene, Sub-Hoyt and Potter sands in Midway-Sunset field. Horizontal wells at the base of these reservoirs and/or structurally downdip near the oil-water contact are ideally suited to take advantage of the gravity drainage production mechanism. Reservoir studies and production experience have shown these horizontal wells should increase reserves, improve recovery efficiency, improve the oil-steam ratio, and improve project profitability. Geological considerations of targeting the wells vary between fields because of the different depositional environments and resulting reservoir characteristics. The thin sands and semicontinuous shales in the Tulare Formation and the Etchegoin Formation require strict structural control on the top and base of the target sand. In the Sub-Hoyt and Potter sands, irregularities of the oil-water contact and sand and shale discontinuities must be understood. Logging and measurement while drilling provide geosteering capability in medium radius wells. Teamwork between all engineering disciplines and drilling and producing operations has been critical to horizontal well success.

  19. Heterogeneity of fluvial-deltaic reservoirs in the Appalachian basin: A case study from a Lower Mississippian oil field in central West Virginia

    SciTech Connect

    Hohn, M.E.; McDowell, R.R.; Matchen, D.L.

    1997-06-01

    Since discovery in 1924, Granny Creek field in central West Virginia has experienced several periods of renewed drilling for oil in a fluvial-deltaic sandstone in the Lower Mississippian Price Formation. Depositional and diagenetic features leading to reservoir heterogeneity include highly variable grain size, thin shale and siltstone beds, and zones containing large quantities of calcite, siderite, or quartz cement. Electrofacies defined through cluster analysis of wireline log responses corresponded approximately to facies observed in core. Three-dimensional models of porosity computed from density logs showed that zones of relatively high porosity were discontinuous across the field. The regression of core permeability on core porosity is statistically significant, and differs for each electrofacies. Zones of high permeability estimated from porosity and electrofacies tend to be discontinuous and aligned roughly north-south. Cumulative oil production varies considerably between adjacent wells, and corresponds very poorly with trends in porosity and permeability. Original oil in place, estimated for each well from reservoir thickness, porosity, water saturation, and an assumed value for drainage radius, is highly variable in the southern part of the field, which is characterized by relatively complex interfingering of electrofacies and similar variability in porosity and permeability.

  20. Age and tectonic evolution of the northwest corner of the West Philippine Basin

    NASA Astrophysics Data System (ADS)

    Doo, Wen-Bin; Hsu, Shu-Kun; Yeh, Yi-Ching; Tsai, Ching-Hui; Chang, Ching-Ming

    2015-09-01

    To understand the tectonic characteristics and age of the northwestern part of the West Philippine Basin (WPB), multi-beam bathymetry and geomagnetic data have been collected and analyzed. The seafloor morphology obviously shows NW-SE trending seafloor fabrics and NE-SW trending fracture zones, indicating a NE-SW seafloor spreading direction. An overlapping spreading center near 22°20'N and 125°E is identified. Besides, numerous seamounts indicate an excess supply of magma during or after the oceanic crust formation. A V-shaped seamount chain near 21°52'N and 124°26'E indicates a southeastward magma propagation and also indicates the location of the seafloor spreading ridge. On the basis of the newly collected geomagnetic data, the magnetic anomaly shows NW-SE trending magnetic lineations. Both bathymetry and geomagnetic data reveal NE-SW seafloor spreading features between the Gagua Ridge and the Luzon Okinawa fracture zone (LOFZ). Our magnetic age modeling indicates that the age of the northwestern corner of the WPB west of the LOFZ is between 47.5 to 54 Ma (without including overlapping spreading center), which is linked to the first spreading phase of the WPB to the east of the LOFZ. In addition, the age of the Huatung Basin is identified to be between 33 to 42 Ma, which is similar to the second spreading phase of the WPB.

  1. Attitude toward menopause and aging: a study on postmenopausal women of West Bengal.

    PubMed

    Dasgupta, Doyel; Ray, Subha

    2013-01-01

    We examined the attitude of postmenopausal women toward menopause and aging with respect to sociodemographic variables and postmenopausal years. Four hundred and eighty postmenopausal women representing Bengali-speaking Hindu ethnic group of West Bengal, India were interviewed about their attitude toward menopause and aging. Information on sociodemographic and reproductive characteristics and menopausal symptoms were also collected. The participants were categorized into four groups based on postmenopausal years (Group 1: ≤2; Group 2: >2 to ≤5; Group 3: >5 to ≤8; and Group 4: >8). The attitude did not differ significantly among different groups, but it differed significantly when compared for residential status and per capita monthly household expenditure (pooled groups), for residential and educational status (Groups 3 and 4), and per capita monthly household expenditure (Group 3). Hierarchical linear regression (stepwise) shows per capita monthly expenditure, age at menopause, years after menopause, and menopausal symptoms (irritability and inability to hold urine) significantly predict attitude.

  2. Age and condition of juvenile catostomids in Clear Lake Reservoir, California

    USGS Publications Warehouse

    Burdick, Summer M.; Rasmussen, Josh

    2013-01-01

    Although infrequent recruitment of new individuals into the adult spawning populations of Lost River suckers (Deltistes luxatus) and shortnose suckers (Chasmistes brevirostris) limits recovery of these species in Upper Klamath Lake, it is not clear that populations are recruitment limited in Clear Lake Reservoir (hereafter Clear Lake). Specifically, some evidence indicates that shortnose suckers may regularly recruit to the adult spawning population in Clear Lake. Therefore, a study of early life history patterns and recruitment dynamics in Clear Lake may lead to a better understanding of what is limiting recovery of suckers in both lakes. Adult suckers in Clear Lake migrate up Willow Creek and its tributaries to spawn in some years, but low flow in Willow Creek may inhibit spawning migrations in other years. It is unclear whether spawning is successful, larvae survive, or how frequently juveniles persist to adulthood. Environmental variables associated with successful spawning or young-of-year survival have not been identified, and early life history for these populations is poorly understood. The U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service, initiated a study in 2011 to better understand juvenile sucker life history in Clear Lake, and to identify constraints in the early life history that may limit recruitment to the adult spawning populations. The relative weights of shortnose suckers from Clear Lake and Upper Klamath Lake were compared to examine differences in condition. However, it is unclear whether the disparity in relative weights between the populations reflects differences in condition, phenotype, or both. Approximately 80 percent of juvenile suckers in Clear Lake are shortnose suckers with some morphologic features similar to Klamath largescale suckers (Catostomus snyderi), whereas juvenile suckers in Upper Klamath Lake can be clearly classified as either shortnose or Lost River suckers. The presence of juvenile suckers

  3. Toxicity identification and high-efficiency treatment of aging chemical industrial wastewater from the Hangu Reservoir, China.

    PubMed

    Li, Wei; Hua, Tao; Zhou, Qixing; Zhang, Shuguang; Rong, Weiying

    2011-01-01

    The Hangu Reservoir, located in Binhai New Area, Tianjin, China, receives mixed wastewater from a chemical industrial park. The aging chemical industrial wastewater is less biodegradable and contains complex hazardous substances, thus having an adverse effect on local ecological service function of the reservoir and on local economic and social development. In this study, key toxicants in the aging chemical industrial wastewater from the Hangu Reservoir were systematically identified by the toxicity identification evaluations (TIEs), and the treatment efficiency of the aging chemical industrial wastewater was examined and optimized by a municipal wastewater treatment process simulated in a laboratory. According to the TIE results using and wheat seeds as tested organisms, Cl, Cu, Pb, and Zn were identified as key toxicants in the aging chemical industrial wastewater, with concentrations of 7349.11, 0.01, 0.07, and 0.07 mg L, respectively, which were confirmed by subsequent spiking approaches. Based on the TIE results, the aging chemical industrial wastewater could be classified as high-salinity wastewater. The co-treatment of the aging chemical industrial wastewater and municipal wastewater may be an effective and low-cost method. The treatment efficiency of the mixed wastewater increased with an increase in the volume ratio of municipal wastewater to aging chemical industrial wastewater. When the volume ratio was 10:1, the best removal efficiencies of chemical oxygen demand, total N, and total P were up to 85.1, 89.3, and 96.5%, respectively, whereas the toxicity unit of the treated wastewater was reduced to 0.50.

  4. Age and provenance of Triassic to Cenozoic sediments of West and Central Sarawak, Malaysia

    NASA Astrophysics Data System (ADS)

    Breitfeld, H. Tim; Galin, Thomson; Hall, Robert

    2015-04-01

    Sarawak is located on the northern edge of Sundaland in NW Borneo. West and Central Sarawak include parts of the Kuching and Sibu Zones. These contain remnants of several sedimentary basins with ages from Triassic to Cenozoic. New light mineral, heavy mineral and U-Pb detrital zircon ages show differences in provenance reflecting the tectonic evolution of the region. The oldest clastic sediments are Triassic (Sadong Formation and its deep marine equivalent Kuching Formation). They were sourced by a Triassic (Carnian to Norian) volcanic arc and reworked Paleoproterozoic detritus derived from Cathaysialand. The Upper Jurassic to Cretaceous Pedawan Formation is interpreted as forearc basin fill with distinctive zircon populations indicating subduction beneath present-day West Sarawak which initiated in the Late Jurassic. Subsequent subduction until the early Late Cretaceous formed the Schwaner Mountains magmatic arc. After collision of SW Borneo and other microcontinental fragments with Sundaland in the early Late Cretaceous, deep marine sedimentation (Pedawan Formation) ceased, and there was uplift forming the regional Pedawan-Kayan unconformity. Two episodes of extension followed and were responsible for basin development on land in West Sarawak from the latest Cretaceous onwards, probably in a pull-apart setting. The first episode is associated with sediments of the Kayan Group, deposited in the Latest Cretaceous (Maastrichtian) to Eocene, and the second episode with Upper Eocene sediments of the Ketungau Basin. Zircon ages indicate volcanic activity throughout the Early Cenozoic in NW Borneo, and inherited zircon ages indicate reworking of Triassic and Cretaceous rocks. A large deep marine basin, the Rajang Basin, was north of the Lupar Line Fault in Central Sarawak (Sibu Zone) from the Late Cretaceous to the Late Eocene. Zircons from sediments of the Rajang Basin indicate they have similar ages and provenance to contemporaneous terrestrial sediments of the Kayan

  5. Seasonal gonadal development and age-related maturity patterns of introduced pumpkinseed (Lepomis gibbosus Linnaeus, 1758) in a heated thermal reservoir and an adjacent river reach.

    PubMed

    Valente, E; Masson, G; Maul, A; Fox, M G; Meyer, A; Pihan, J C

    2016-05-01

    Testis and ovarian maturation status, maturity profile and gonado-somatic index (GSI) were assessed in pumpkinseed (Lepomis gibbosus) collected from Mirgenbach, a cooling-water reservoir associated with a nuclear power plant, and from the River Moselle 7km downstream of the reservoir's thermal outflow. Histological investigation indicated that in both sexes, gonadal development of pumpkinseed in the heated reservoir was more advanced than in the cooler Moselle River throughout the breeding season. The histological maturity profile of reservoir males ranked by the advancement of sperm cells was highly correlated with its GSI (rs=0.73, P<0.001). GSI of females in the reservoir increased with the stage at maturity, but GSI was not significantly correlated with total length, age or growth rate of the individual. All sampled individuals of both sexes were mature at age 1 in the heated reservoir, whereas 48% of age 1 males and 57% of age 1 females were not mature in the river. GSI patterns suggest that males in the reservoir adopted one of two reproductive strategies (nesters or cuckolders), whereas no small males with large enough testes to be considered cuckolders were apparent in the river. The warm thermal regime of Mirgenbach Reservoir led to precocial maturity, early season reproduction, and the greater prevalence of apparent cuckolder males than would normally occur in this climatic zone. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Study of the mixing and ageing of polluted plumes from major West Africa cities

    NASA Astrophysics Data System (ADS)

    Tocquer, Flore; Mari, Céline; Leriche, Maud; Dacciwa Team

    2017-04-01

    Massive economic and population growth, fast urbanization in megacities along the Guinea Coast, would triple anthropogenic emissions by 2030 (Knippertz et al., 2015). Impacts of the rapid increase of atmospheric pollutants on weather and climate in this region are largely unstudied due to a lack of observations. The DACCIWA (Dynamics-aerosol-chemistry-cloud interactions in West Africa) project carried out an important airborne measurements campaign in June-July 2016 together with ground-based observations in urban and remote sites. Urban and industrial, biogenic dominated environment, dust and biomass burning air masses, ship plumes and flaring emissions were sampled successfully. The goal of this work is to investigate the transport and ageing of anthropogenic emissions from major West African megacities during boreal summer. For this purpose, the coupled atmosphere-chemistry mesoscale model Méso-NH was run at kilometric scale and results were compared with in-situ meteorological and chemical data. The study focuses on 06-07-08 July 2016. Three research aircrafts operated over the coastal region sampling downwind pollution from Lomé and Accra and biogenic emissions further inland. Preliminary simulation results will be presented to understand the mixing between and ageing of cities plumes during the post-onset period of the campaign.

  7. Space-geodetic evidence of shallow magma reservoirs in the West-Sunda arc; Insights from global data compilation on what controls magma ascent in volcanic arcs

    NASA Astrophysics Data System (ADS)

    Chaussard, E.; Amelung, F.

    2011-12-01

    A large proportion of the world's population lives on or near active volcanoes. Ground deformation measurements are key observations for volcano monitoring not only because they allow identification of precursory uplift caused by ascent of new magma towards the surface but also because volcanic hazard assessment relies on interpretations of geodetic data in terms of depth of magma accumulation. Here we conducted a global survey of the West-Sunda volcanic arc using differential InSAR combined with SBAS-time series analysis covering an area of about 500 000 km2 on the islands of Sumatra, Java and Bali. The compiled ground velocity map reveals the background level of activity of the 84 volcanic centers of the West-Sunda arc. We identified uplift at 6 volcanic centers and subsidence at 2 edifices. Interestingly, 3 of the 6 uplifting centers erupted after the time period of our survey, suggesting that edifice inflation is a precursor of eruptions. Elastic half-space models of the measured deformation give quantitative estimates of the depths of the magmatic sources and reveal that the sources of inflation are located at shallow depths, less than 3km under the sea level. To interpret these results from a global point of view we compiled data of magma chamber depths in volcanic arcs. Because magma primarily rises by buoyancy forces, in the absence of exterior stress, magma chambers are expected to develop at the level of neutral buoyancy, where magma first encounters a crustal density similar to its density, typically between 5 and 10km for Andesitic volcanoes [Ryan, 1987]. Magma chambers around these depths are found in most volcanic arcs, such as the Central Andes [Pritchard, 2004; Pritchard and Simons, 2004]. However, some volcanic arcs present in addition to magma chambers at these levels, shallower reservoirs, above 4km depth. It is the case in the Aleutian arc, the Costa-Rican arc and, from our survey, the West-Sunda arc [Lu et al., 2002; Lu, 2007; Alvarado et al

  8. Surface exposure dating of Little Ice Age ice cap advances on Disko Island, West Greenland

    NASA Astrophysics Data System (ADS)

    Lane, Timothy; Jomelli, Vincent; Rinterknecht, Vincent; Brunstein, Daniel; Schimmelpfennig, Irene; Swingedouw, Didier; Favier, Vincent; Masson-Delmotte, Valerie

    2015-04-01

    Little Ice Age (LIA: 1200-1920 AD) glacier advances in Greenland often form the most extensive positions of Greenland Ice Sheet (GrIS) ice cap and margins since the Early Holocene. Across Greenland these advances are commonly represented by un-vegetated moraines, usually within 1-5 km of the present ice margin. However, chronological constraints on glacier advances during this period are sparse, meaning that GrIS and ice cap behavior and advance/retreat chronology remains poorly understood during this period. At present the majority of ages are based on historical accounts, ice core data, and radiocarbon ages from proglacial threshold lakes. However, developments in the accuracy and precision of surface exposure methods allow dating of LIA moraine boulders, permitting an opportunity to better understand of ice dynamics during this period. Geomorphological mapping and surface exposure dating (36Cl) were used to interpret moraine deposits from the Lyngmarksbræen on Disko Island, West Greenland. A Positive Degree Day (PDD) model was used to estimate Equilibrium Line Altitude (ELA) and mass balance changes for two distinct paleo-glacial extents. Three moraines (M1, M2, and M3) were mapped in the field, and sampled for 36Cl surface exposure dating. The outermost moraine (M1) was of clearly different morphology to the inner moraines, and present only in small fragments. M2 and M3 were distinct arcuate termino-lateral moraines within 50 m of one another, 1.5 km from the present ice margin. The weighted average of four 36Cl ages from M1 returned an early Holocene age of 8.4 ± 0.6 ka. M2 (four samples) returned an age of 0.57 ± 0.04 ka (1441 AD) and M3 (four samples) returned an age of 0.28 ± 0.02 ka (1732 AD). These surface exposure ages represent the first robustly dated Greenlandic ice cap moraine sequence from the LIA. The two periods of ice cap advance and marginal stabilisation are similar to recorded periods of LIA GrIS advance in west Greenland, constrained

  9. Impact of age of rubber (Hevea brasiliensis) plantation on earthworm communities of West Tripura (India).

    PubMed

    Chaudhuri, P S; Bhattacharjee, Subhalaxmi; Dey, Animesh; Chattopadhyay, Sharmila; Bhattacharya, Dipto

    2013-01-01

    A comparative analysis of earthworm communities was carried out in the rubber plantations (Hevea brasiliensis) of different age groups in West Tripura to understand the impact of such exotic and monoculture plantation in biodiversity conservation. Earthworm communities were studied on monthly basis over a period of one year (2006-2007) in the 3, 10, 14, 20 and 25 year-old plantations. Among twelve earthworm species collected from the studied sites, six species belonged to Octochaetidae [Eutyphoeus assomensis Stephenson, Eutyphoeus comillahnus Michaelsen, Lennogaster chittagongensis (Stephensen), Octochaetona beatrix Gates, Dichogaster offinis Michaelsen, Lennogaster yeicus (Stephensen)], two species each to Megascolecidae [Metaphire houlleti (Perrier), Konchurio sp. 1] and Moniligastridae [Drowida nepalensis Michaelsen, Drawida papillifer papillifer Stephenson], one species each to Glossoscolecidae [Pontoscolex corethrurus (Muller)] and Ocnerodrilidae [Gordiodrilus elegans Beddard]. Exotic species P corethrurus, M. houlleti and native peregrine species like D. nepolensis and D. papillifer papillifer were distributed in all the age groups of plantation, while other species showed restricted distribution. P. corethrurus contributed more than 60% biomass and 70% density of earthworm communities in rubber plantation. With aging of rubber plantations both the densities and biomasses of earthworms increased. High contents of polyphenol, flavonoid and lignin in the litters of 3 and 10 year-old-rubber plantations through their effects on food intake, probably resulted to low biomass values of earthworms in those age groups of plantation. With further increase in the age of plantations beyond 10 years, polyphenol, flavonoid and lignin contents decreased. Accordingly the biomass of earthworms increased with increase in the age of plantation. Soil moisture increased with increase in the age of plantation and there was a good positive correlation between soil moisture and

  10. Refined modeling and 14C plateau tuning reveal consistent patterns of glacial and deglacial 14C reservoir ages of surface waters in low-latitude Atlantic

    NASA Astrophysics Data System (ADS)

    Balmer, Sven; Sarnthein, Michael; Mudelsee, Manfred; Grootes, Pieter M.

    2016-08-01

    Modeling studies predict that changes in radiocarbon (14C) reservoir ages of surface waters during the last deglacial episode will reflect changes in both atmospheric 14C concentration and ocean circulation including the Atlantic Meridional Overturning Circulation. Tests of these models require the availability of accurate 14C reservoir ages in well-dated late Quaternary time series. We here test two models using plateau-tuned 14C time series in multiple well-placed sediment core age-depth sequences throughout the lower latitudes of the Atlantic Ocean. 14C age plateau tuning in glacial and deglacial sequences provides accurate calendar year ages that differ by as much as 500-2500 years from those based on assumed global reservoir ages around 400 years. This study demonstrates increases in local Atlantic surface reservoir ages of up to 1000 years during the Last Glacial Maximum, ages that reflect stronger trades off Benguela and summer winds off southern Brazil. By contrast, surface water reservoir ages remained close to zero in the Cariaco Basin in the southern Caribbean due to lagoon-style isolation and persistently strong atmospheric CO2 exchange. Later, during the early deglacial (16 ka) reservoir ages decreased to a minimum of 170-420 14C years throughout the South Atlantic, likely in response to the rapid rise in atmospheric pCO2 and Antarctic temperatures occurring then. Changes in magnitude and geographic distribution of 14C reservoir ages of peak glacial and deglacial surface waters deviate from the results of Franke et al. (2008) but are generally consistent with those of the more advanced ocean circulation model of Butzin et al. (2012).

  11. Ochoan (upper Permian) stratigraphy and age determinations, southeastern New Mexico and west Texas

    SciTech Connect

    Lucas, S.G. ); Anderson, O.R. )

    1994-03-01

    Upper Permian strata, which are the stratotype of the Ochoan State (Series), have an extensive subsurface distribution and limited outcrop area in southeastern New Mexico and west Texas. The oldest strata are alternating laminae of anhydrite and calcite of the Castile Formation and are as much as 700 m thick. The closely related and overlying Salado Formation is a much as 600 m thick and is mostly halite and argillaceous halite with minor anhydrite. The overlying Rustler Formation is as much as 150 m thick and consists of anhydrite, red silty shale and magnesian limestone. Overlying red beds are the Quartermaster Formation (Dewey Lake Formation is a synonym, as is the term Pierce Canyon red beds), which is as much as 106 m thick and consist of fine sandstones, siltstones, and minor gypsum. The Castile rests disconformably on the Capitanian (middle Permian) Lamar Limestone Member of the Bell Canyon Formation and its equivalent, the Tansill Formation of the Artesia Group. Counting of Castile-Salado laminae and their posited relationship to astronomical cycles suggests that Castile-Salado deposition took only 200,000-300,000 yr. Limited assemblages of brachiopods and conodonts from the Rustler Formation indicate a Late Permian age, but are no more precise age indicators. A small assemblage of bivalves, K-Ar ages and magnetostratigraphy indicate a late Permian age for the Quartermaster Formation. There is no evidence to support a Triassic age assignment for the Quarter-master; it is disconformably overlain by the Upper Triassic (Carnian) Chinle group. Most workers us the Ochoan as a Late Permian Stage-Age, although its typical strata generally lack good age indicators and may represent relatively short and sporadic intervals of the Late Permian. We prefer recognition of the Ochoan as a lithostratigraphic unit (group) without regional or global geochronologial significance.

  12. Optimal water resources management and system benefit for the Marcellus shale-gas reservoir in Pennsylvania and West Virginia

    NASA Astrophysics Data System (ADS)

    Cheng, Xi; He, Li; Lu, Hongwei; Chen, Yizhong; Ren, Lixia

    2016-09-01

    A major concern associated with current shale-gas extraction is high consumption of water resources. However, decision-making problems regarding water consumption and shale-gas extraction have not yet been solved through systematic approaches. This study develops a new bilevel optimization problem based on goals at two different levels: minimization of water demands at the lower level and maximization of system benefit at the upper level. The model is used to solve a real-world case across Pennsylvania and West Virginia. Results show that surface water would be the largest contributor to gas production (with over 80.00% from 2015 to 2030) and groundwater occupies for the least proportion (with less than 2.00% from 2015 to 2030) in both districts over the planning span. Comparative analysis between the proposed model and conventional single-level models indicates that the bilevel model could provide coordinated schemes to comprehensively attain the goals from both water resources authorities and energy sectors. Sensitivity analysis shows that the change of water use of per unit gas production (WU) has significant effects upon system benefit, gas production and pollutants (i.e., barium, chloride and bromide) discharge, but not significantly changes water demands.

  13. Depositional and diagenetic controls on porosity permeability and oil production in McFarland/Magutex (Queen) reservoirs, Andrews County, west Texas

    SciTech Connect

    Holtz, M.H. )

    1991-03-01

    The McFarland/Magutex Queen reservoir complex lies along the northeastern edge of the Central basin platform in the west Texas Permian basin and produces oil from the Permian Queen Formation. Current production from this complex totals 42 million stock-tank barrels (MMSTB) of an estimated 219 MMSTB of original oil in place, with an estimated 90 MMSTB of remaining mobile oil (RMO). The gross pay interval contains two parasequences consisting of progradational, 30-ft-thick, upward-shoaling facies packages. Facies include shoreface, mixed tidal channel and intertidal flat, and supratidal. Elongate shoreface facies are characterized by poorly consolidated, massive to thinly laminated sandstones. The supratidal facies, which act as permeability barriers, are characterized by algal-laminated dolostone and nodular, laminated, and massive anhydrite containing halite and gypsum pseudomorphs. Highest production and the largest amount of the 90 MMSTB of RMO is associated with the shoreface and tidal-channel facies. Bulk pore volume storage capacity and permeability are also highest within these two facies. Sandstones are arkosic, containing anhydrite and dolomite cements. Accessory minerals are clays, authigenic feldspar, and dolomite. Three main pore types are recognized: interparticle, moldic and intraconstituent, and micropores. Moldic and intraconstituent porosity is associated with leached feldspars and anhydrite cement dissolution. Microporosity is associated with syndepositional, grain-coating corrensite, dissolution-enhanced feldspar cleavage planes, and authigenic multifaceted dolomite. Microporosity derived from clays and dolomite is formed preferentially in tidal-channel and intertidal flat facies.

  14. [Age of maturity in alpine herbaceous perennials, the North-West Caucasus].

    PubMed

    Kipkeev, A M; Onipchenko, V G; Tekeev, D K; Érkenova, M A; Salpagarova, F S

    2014-01-01

    Sod transplantation experiment was carried out for 24 years in alpine communities, Teberda Reserve, the North-West Caucasus, Russia. Age of maturity (AOM) was estimated as a period between first registra- tion of a species on.a permanent plot and flowering shoot appearance. Mean species AOM varied from 2.3 years (Antennaria dioica with clonal propagation) to 13.7 years for Taraxacum stevenii (non-clonal plant). General gradient of alpine plant traits and population strategies was determined. It represents a continuum ranging from ruderal--stress-tolerants (shorter AOM, clonality, shorter leaf life span, low rate of mycorrhizal infection, low regrowth ability, low generative shoot number, low specific leaf area and leaf nitrogen content) to competitor--stress-tolerants (longer AOM, longer leaf life span, higher rate of mycorrhizal infection, higher regrowth ability, high generative shoot number, high specific leaf area and leaf nitrogen content).

  15. Climate hazards, adaptation and "resilience" of societies (early Little Ice Age, west of France).

    NASA Astrophysics Data System (ADS)

    Athimon, Emmanuelle; Maanan, Mohamed

    2016-04-01

    Over the past ten to fifteen years, climate hazards and adaptation have received more attention due to the current climate change. Climate historians have gathered strong evidence that the world's climate has evolved over the past millennium and one of the most significant changes took place during the Little Ice Age. Recently, a set of questions has emerged: what were the effects of the Little Ice Age on human's societies? How did humans adapt to these climate changes? How did they react to extreme weather-related events? Using examples of climate hazards from the West of France during the beginning of the Little Ice Age (xivth-xviith centuries) such as storms, flooding, drought, harsh winters, the poster aims at showing how the past societies can constitute a source of inspiration for present ones. Through schemas, this research exposes the system's rebound capacity, points out the importance of the historical depth in research on human's adaptation and resilience and shows the value of integrating a historical approach. It reveals that History contributes to the knowledge of the relationship between societies and climate hazards. Data on climate hazards and adaptation of societies stem from historical sources such as chronicles, diaries, books of accounts, records of cities repairs. To protect themselves and their goods, medieval and modern societies had developed specific skills, practices and strategies. From the xivth to the xviiith century, there is an increase of defense by dikes in the low Loire, as for example the construction of those amongst Longué and Ponts-de-Cé between the early xivth century and 1407. The French kingdom's authorities also tried increasingly to provide technical, material, logistical and fiscal support: for instance, during the winter 1564-1565, several bridges have been destroyed by a river flooding in Nantes. The King Charles IX then offered to people of Nantes part of the funds from taxes on the main activities such as the

  16. Age constraints of the Wassa and Benso mesothermal gold deposits, Ashanti Belt, Ghana, West Africa

    NASA Astrophysics Data System (ADS)

    Parra-Avila, Luis A.; Bourassa, Yan; Miller, John; Perrouty, Stéphane; Fiorentini, Marco L.; Campbell McCuaig, T.

    2015-12-01

    The Ashanti Belt in Ghana hosts numerous multi-million ounce gold deposits and is one of the most richly gold endowed Paleoproterozoic belts of the West African Craton. This work shows that the Wassa mineralized intrusion is part of the Sefwi Group. This unit at Wassa is strongly magnetic and show a distinctly high response in regional magnetic data sets compared to other units of equivalent age within the belt. The unit is inferred to be a lateral extension of an exposed fragment of what defines the substrate to the Tarkwa Basin sediments. The Wassa deposit, located in the eastern limb of the belt, is hosted within mafic to intermediate volcanic flows that are interbedded with minor horizons of volcaniclastics, clastic sediments. The clastic sediments include wackes and magnetite rich sedimentary layers, presumably derived from banded iron formations. The previously described sequence is intruded by syn-volcanic mafic intrusives and felsic porphyries rocks that are all part of the Birimian stratigraphy. Two new key SHRIMP II U-Pb ages were determined as part of this study: a new age of 2191 ± 6 Ma was determined on magmatic zircon grains of the Wassa porphyry host rock, which now represents the oldest known felsic intrusion hosting gold mineralization in the Ashanti Belt region. The Benso gold deposit system, which is located in the eastern limb of the Ashanti Belt approximately 38 km southwest of Wassa is hosted within a series of volcanic units intruded by mafic to intermediate units. A SHRIMP II U-Pb age of 2157 ± 5 Ma was determined from magmatic zircons obtained from a granodiorite of the G-Zone of the Benso deposit. This granodiorite is the main host rock for gold mineralization and thus the age provides an upper constraint for mineral emplacement. The newly determined ages provide an upper constraint for the gold mineralization within this region of the Ashanti Belt. They also support recent structural studies that have interpreted that the Wassa

  17. The silent burden of anemia in school age children: a community based study in West Bengal.

    PubMed

    Gupta, Soma; Taraphdar, Pranita; Roy, Tapobrata Guha; Haldar, Dibakar; Dey, Sujit Kumar; Purkait, Bulbul

    2012-01-01

    Under nutrition and anemia are common co-morbidities in school age children. Due to transition in dietary habits in developing countries, a paradoxical finding of coexistence of anemia and normal/over nutrition is also a cause of concern. > T o assess the nutritional status and prevalence of anemia among school age children (6 - 16 years) residing in rural and urban areas of a district of West Bengal and also to find out the association between weight status, measured as Body Mass Index(BMI) and anemia. Age, height & weight were measured in 86 rural and 86 urban school age (6 -16 years) children in rural and urban field practice areas of Midnapore Medical College. Their blood was estimated for haemoglobin concentration. Overall prevalence of anemia was 80.2%, and not significantly different between the rural (83.7%) and urban (76.7%) participants and across the genders both in rural (86.4% versus 80.9%) and urban (85.7% versus 72.4%) areas. Thinness was observed to be higher in urban area (48.8% versus 41.9%). However, severe thinness was higher in rural area (18.5% versus 13.9%). Significantly, higher proportion of boys revealed severely low BMI compared to girls in both rural (33.3% versus 4.5%) and urban (17.2% versus 7.1%) areas with no significant differences between the prevalence of anemia across the grades of underweight and normal nutritional status. Poor nutritional status and anemia are still, taking heavy toll and new program strategies are needed, particularly those that improve the overall nutrition status of children.

  18. Age and nature of Triassic magmatism in the Netoni Intrusive Complex, West Papua, Indonesia

    NASA Astrophysics Data System (ADS)

    Webb, Max; White, Lloyd T.

    2016-12-01

    We report field observations together with petrological, geochemical and geochronological data from granitoids of the Netoni Intrusive Complex of West Papua. Until now, our knowledge of the timing of granitic magmatism in this region has been limited to a wide range of ages (241-6.7 Ma) obtained from K-Ar measurements of hornblende, biotite and plagioclase, primarily from samples of river detritus. We collected in situ samples along several traverses into the intrusive complex to: (1) develop a better understanding of the lithologies within the intrusive complex; and (2) determine the timing of magmatism using U-Pb dating of zircon. We also dated zircons from two river sand samples to identify other potential pulses of magmatism that may have been missed due to a sampling bias. The zircons extracted from the river sands yield age spectra similar to those obtained from the in situ samples. The combined data demonstrate that magmatism in the Netoni Intrusive Complex occurred between 248 Ma and 213 Ma. The petrological and geochemical data indicate that the granitoids were most likely emplaced in an ocean-continent (Andean style) subduction setting. This builds on previous work which suggests that a magmatic belt extended along eastern Gondwana (now New Guinea and eastern Australia) throughout much of the Paleozoic. The volcanic ejecta that were produced along this arc and the subsequent erosion of the mountain chain are a potential source of detritus for Triassic and younger sedimentary rocks in New Guinea, eastern Indonesia and north/northwestern Australia.

  19. Lu-Hf total-rock age for the Amitsoq gneisses, West Greenland

    NASA Technical Reports Server (NTRS)

    Pettingill, H. S.; Patchett, P. J.

    1981-01-01

    Lu-Hf total-rock data for the Amitsoq gneisses of West Greenland yield an age of 3.55 + or - 0.22 billion years, based on the decay constant for Lu-176 of 1.96 x 10 to the -11th/year, and an initial Hf-176/Hf-177 ratio of 0.280482 + or - 33. The result is in good agreement with Rb-Sr total-rock and U-Pb zircon ages. In spite of severe metamorphism of the area at 2.9 billion years, zircons from two of the samples have remained on the total-rock line, and define points close to the initial Hf ratio. The initial Hf-176/Hf-177 lies close to a chondritic Hf isotopic evolution curve from 4.55 billion years to present. This is consistent with the igneous precursors to the Amitsoq gneisses having been derived from the mantle at or shortly before 3.6 billion years. Anomalous relationships between Hf concentration and the Lu-176/Hf-177 ratio may suggest that trace element abundances in the Amitsoq gneisses are partly controlled by processes related to metamorphism.

  20. Effects of uneven-aged and diameter-limit management on West Virginia tree and wood quality

    Treesearch

    Michael C. Wiemann; Thomas M. Schuler; John E. Baumgras

    2004-01-01

    Uneven-aged and diameter-limit management were compared with an unmanaged control on the Fernow Experimental Forest near Parsons, West Virginia, to determine how treatment affects the quality of red oak (Quercus rubra L.), sugar maple (Acer saccharum Marsh.), and yellow-poplar (Liriodendron tulipifera L.). Periodic harvests slightly increased stem lean, which often...

  1. Holocene radiocarbon-dated sites in northeastern Siberia: issues of temporal frequency, reservoir age, and human-nature interaction.

    PubMed

    Kuzmin, Yaroslav V

    2010-01-01

    The existing corpus of data on radiocarbon dates for Holocene sites in Northeastern Siberia was used as proxy to reconstruct the chronology of human occupation of the region. The problem of reservoir age correction in the Bering Sea region complicated this task and this issue needs to be solved in order to obtain more reliable age determinations for coastal archaeological sites. Using a chronology built after excluding the questionable dates from the database, the major patterns of human population dynamics and their possible correlation with climatic fluctuations were examined. No direct relationship appears to exist between these two processes. Additional archaeological and paleo environmental work needs to be carried out in this region of the North.

  2. Geoscience/Engineering Characterization of the Interwell Environment in Carbonate Reservoirs Based on Outcrop Analogs, Permian Basin, West Texas and New Mexico.

    SciTech Connect

    Lucia, F.J.; Kerans, C.

    1997-05-29

    The objective of this project is to investigate styles of reservoir heterogeneity found in low permeability pelleted wackestone/packstone facies and mixed carbonate/clastic facies found in Permian Basin reservoirs by studying similar facies found in Permian Basin reservoirs by studying similar facies exposed in the Guadalupe Mountains. Specific objectives for the outcrop study include construction of a stratigraphic framework, petrophysical quantification of the framework, and testing the outcrop reservoir model for effects of reservoir heterogeneity on production performance. Specific objectives for the subsurface study parallel objectives for the outcrop study.

  3. The Potential Impact of Increased Phosphorus Loads in Lakes Acting as Heavy Metal Reservoirs: A case study from west-central Indiana

    NASA Astrophysics Data System (ADS)

    McLennan, D. A.; Latimer, J. C.; Smith, E.; Stone, J.

    2015-12-01

    Green Valley Lake is a designated state fishing area in west-central Indiana. Prior to this designation, the lake was a water supply reservoir for the adjacent and now abandoned Green Valley Coal Mine (Operating from 1948-1963). The Green Valley Coal Mine property continues to produce excess acidity despite reclamation efforts. The former mine property and the lake are connected by a channel that discharges acidic drainage directly into Green Valley Lake. To evaluate temporal variability in metal and phosphorus (P) geochemistry, two short cores were collected in spring 2014 (38cm) and spring 2015 (39cm). Metal concentrations were determined by a hand-held X-ray fluorescence analyzer after the samples had been dried and crushed. Approximately 20% of these metal concentrations will be verified by ICP-OES following extraction in 50% aqua regia. Detailed P geochemistry was determined using a sequential extraction technique (SEDEX). The sediments in Green Valley Lake are characterized by heavy metal concentrations that are elevated above typical background levels. These metals tend to be concentrated near the sediment water interface, often 3-5 times greater than the average concentration for the rest of the core, which suggests that they are diagenetically mobile and possibly diffusing out of the sediments under dysoxic to anoxic conditions and returning to the sediments under oxic conditions. Total sedimentary P averages 57 umol/g, but oscillates between 20 - 110 umol/g. The most dramatic shift in the detailed P geochemistry is the significant reduction of mineral P at 15 cm and the increasing importance of oxide-associated and adsorbed P upcore. Diatom assemblages suggest that the lake has become increasingly more eutrophic over time. As nutrient loads continue to increase, the oxygen depleted zone may expand impacting fish populations and changing water geochemistry significantly, in particular, mobilizing heavy metals.

  4. 14C age determination for human bones during the Yayoi period - the calibration ambiguity around 2400 BP and the marine reservoir effect

    NASA Astrophysics Data System (ADS)

    Mihara, S.; Miyamoto, K.; Nakamura, T.; Koike, H.

    2004-08-01

    14C ages for Japanese prehistoric samples from the Latest Jomon period to the early Yayoi period have a calibration ambiguity for dates around 2400 BP. It is also necessary to correct for the marine reservoir effect on 14C ages of human bone samples from people who consumed marine food as a protein source. The Ohtomo site in western Japan, is a cemetery site used from the end of the Latest Jomon period to the Kofun period, provide a useful archaeological chronology. Human bones found in dolmen burials, jar burials and cist burials. In this study, we determined the 14C ages of human bone samples and calculated the marine reservoir effect, using diet analysis based on carbon and nitrogen stable isotopes. Diet analysis showed that these people obtained from 40% to 60% of their protein from marine sources. Their 14C ages with calibration and marine reservoir correction were serially matched with the archaeological chronology.

  5. Variability of 14C reservoir age and air-sea flux of CO2 in the Peru-Chile upwelling region during the past 12,000 years

    NASA Astrophysics Data System (ADS)

    Carré, Matthieu; Jackson, Donald; Maldonado, Antonio; Chase, Brian M.; Sachs, Julian P.

    2016-01-01

    The variability of radiocarbon marine reservoir age through time and space limits the accuracy of chronologies in marine paleo-environmental archives. We report here new radiocarbon reservoir ages (ΔR) from the central coast of Chile ( 32°S) for the Holocene period and compare these values to existing reservoir age reconstructions from southern Peru and northern Chile. Late Holocene ΔR values show little variability from central Chile to Peru. Prior to 6000 cal yr BP, however, ΔR values were markedly increased in southern Peru and northern Chile, while similar or slightly lower-than-modern ΔR values were observed in central Chile. This extended dataset suggests that the early Holocene was characterized by a substantial increase in the latitudinal gradient of marine reservoir age between central and northern Chile. This change in the marine reservoir ages indicates that the early Holocene air-sea flux of CO2 could have been up to five times more intense than in the late Holocene in the Peruvian upwelling, while slightly reduced in central Chile. Our results show that oceanic circulation changes in the Humboldt system during the Holocene have substantially modified the air-sea carbon flux in this region.

  6. Magmas, Mushes and Mobility: Thermal Histories of Magma Reservoirs from Combined U-Series and Diffusion Ages

    NASA Astrophysics Data System (ADS)

    Cooper, K. M.; Rubin, A. E.; Schrecengost, K.; Kent, A. J.; Huber, C.

    2014-12-01

    The thermal conditions of magma storage control many aspects of the dynamics of a magma reservoir system. For example, the temperature of magma storage directly relates to the crystallinity, and magmas stored at relatively low temperatures in a crystal mush (more than 40-50% crystalline) must be remobilized (e.g., by heating) before they can be erupted. A better understanding of the duration of magma storage at largely-liquid vs. largely-solid conditions is thus critical to understanding crustal magmatic processes such as magma mixing and for quantifying the hazard potential of a given volcano. Although mineral thermometry reflects the conditions of crystal growth or equilibration, these may not correspond to the thermal conditions of crystal storage. The duration of crystal storage at high temperatures can be quantified by comparing U-series crystal ages with the time scales over which disequilibrium trace-element profiles in the same crystals would be erased by diffusion. In the case of Mount Hood, OR, such a comparison for the two most recent eruptions shows that <12% of the total lifetime of plagioclase crystals (minimum 21 kyr) was spent at temperatures high enough that the magma would be easily mobilized. Partial data sets for other systems suggest such behavior is common, although the diffusion and U-series ages in these cases are from different samples and may not be directly comparable. We will present preliminary data combining U-series dating and diffusion timescales on the same samples for other volcanic systems (e.g., Lassen Volcanic Center, Mount St. Helens, Okataina Volcanic Center, New Zealand). Combining these data with numerical models offers additional insights into the controls on the conditions of storage. In addition, extension of this approach to combining U-Th ages with time scales of Li diffusion in zircon offers a promising new method to quantify thermal histories of silicic reservoir systems.

  7. Water-power resources in upper Carson River basin, California-Nevada, A discussion of potential development of power and reservoir sites on east and west forks, Carson River

    USGS Publications Warehouse

    Pumphrey, Harold L.

    1955-01-01

    West Fork Carson River offers the best opportunity for power development in the Carson River basin. The Hope Valley reservoir site could be developed to provide adequate storage regulation and concentration of fall would permit utilization of 1,400 feet of head in 51h miles below the clam site, or 1,900 feet of head in about 972 miles below the dam site; however, the average annual runoff susceptible of development is only about 70,000 acre-feet which limits the power that could be developed continuously in an average year with regulation to about 8,700 kilowatts utilizing 1,400 feet of head, or 12,000 kilowatts utilizing 1,900 feet of head. The method and degree of development will be determined to large extent by the method devised to supplement regulated flows from the Hope Valley reservoir to supply the water already appropriated for irrigation. If the Hope Valley site and the Watasheamu site on East Fork Carson River were developed coordinately water could be transferred to the West Fork for distribution through canals leading from that stream thus satisfying the deficiency due to regulation at Hope Valley and release of stored water on a power schedule. This would permit utilization of the entire 1,900 feet of fall. Independent development of the West Fork for optimum power production would require re-regulation of releases from Hope Valley reservoir and storage of a considerable part of the fall and winter flow for use during the irrigation season. Adequate storage capacity is apparently not available on the West Fork below Hope Valley; but offstream storage may be available in Diamond Valley which could be utilized by diversion from the West Fork near Woodfords. This would limit the utilization of the stream for power purposes to the development of the 1,400 feet of head between the Hope Valley dam site and Wood fords. In a year of average discharge East Fork Carson River and three of its principal tributaries could be developed to produce about 13

  8. Radiocarbon profiles of the NW Pacific from the LGM and deglaciation: Evaluating ventilation metrics and the effect of uncertain surface reservoir ages

    NASA Astrophysics Data System (ADS)

    Cook, Mea S.; Keigwin, Lloyd D.

    2015-03-01

    During the last deglaciation, the ventilation of the subarctic Pacific is hypothesized to have changed dramatically, including the rejuvenation of a poorly ventilated abyssal water mass that filled the deep ocean, and fluctuations in the strength of North Pacific intermediate and deep water formation at millennial timescales. Foraminiferal radiocarbon reconstructions of past ventilation changes in the Pacific are valuable but are hampered by poor carbonate preservation, low sediment accumulation rates, bias from bioturbation, and poorly constrained past surface reservoir age. In this study, we present paired benthic-planktonic radiocarbon measurements from the Okhotsk Sea and Emperor Seamounts. We take advantage of large contemporaneous peaks in benthic abundances from the last glacial maximum, Bolling-Allerod (BA), and early Holocene to produce time slices of radiocarbon from 1 to 4 km water depth. We explore the impact of uncertain surface reservoir age and evaluate several approaches to quantifying past ocean radiocarbon distribution using our NW Pacific data and a compilation of published data from the North Pacific. Both the calendar age and the absolute value of an ocean radiocarbon estimate depend on the assumed surface reservoir age. But for a time slice from a small geographical area with radiocarbon-independent stratigraphic correlation between cores, the shape of a water column profile is independent of surface reservoir age. The NW Pacific profiles are similar in shape to the compilation profiles for the entire North Pacific, which suggests that deglacial surface reservoir age changes across the N Pacific did not diverge dramatically across the areas sampled. The Last Glacial Maximum (LGM) profile >2 km spans a wide range of values, ranging from values similar to today to lower than today. However, by the BA the profile has a similar shape to today. Ultimately, local surface reservoir ages, end-member water mass composition, and mixing ratios must each

  9. Environmental effects of western coal surface mining. Part V: Age and growth of walleyes and saugers in the Tongue River Reservoir, Montana, 1975-77. Final report

    SciTech Connect

    Riggs, V.L.; Gregory, R.W.

    1980-03-01

    A study was conducted between 1975-1977 on the populations of walleye (Stizostedion vitreum) and sauger (Stizostedion canadense) in the Tongue River Reservoir, in southeastern Montana. The Tongue River Reservoir is the recipient of mine water effluents from the Decker Mine, the largest surface coal mine in the western United States. The objective of the study was to determine possible impacts of the mine on the walleye and sauger populations in the reservoir, and to provide data against which future comparisons can be made. These species were chosen because they are two of the most important game fishes in the reservoir. The age and growth of 640 walleyes and 546 saugers were determined from collections made in gill nets, trap nets, and by electrofishing.

  10. Geoscience/Engineering Characterization of the Interwell Environment in Carbonate Reservoirs Based on Outcrop Analogs, Permian Basin, West Texas and New Mexico.

    SciTech Connect

    Lucia, F.J.; Kerans, C.

    1996-12-31

    The objective of this project is to investigate styles of reservoir heterogeneity found in low permeability pelleted wackestone/packstone facies and mixed carbonate/clastic facies found in Permian Basin reservoirs by studying similar facies exposed in the Guadalupe Mountains. Specific objectives for the outcrop study include construction of a stratigraphic framework, petrophysical quantification of the framework, and testing the outcrop reservoir model for effects of reservoir heterogeneity on production performance. Specific objectives for the subsurface study parallel objectives for the outcrop study.

  11. The Mean Age of Mantle and Crustal Reservoirs for the Planet Mars

    NASA Technical Reports Server (NTRS)

    Jacobsen, S. B.; Yin Q-Z.

    2002-01-01

    Based on all available isotopic and trace element data for SNCs we obtain a mean age of formation of the crust on Mars of 3.4 +/- .6 Ga. Additional information is contained in the original extended abstract.

  12. Test of Continental Drift by Comparison of Radiometric Ages: A pre-drift reconstruction shows matching geologic age provinces in West Africa and Northern Brazil.

    PubMed

    Hurley, P M; Rand, J R; Pinson, W H; Fairbairn, H W; de Almeida, F F; Melcher, G C; Cordani, U G; Kawashita, K; Vandoros, P

    1967-08-04

    1) The distribution of age values obtained by potassium-argon determinations and whole-rock rubidium-strontium determinations appears to be almost identical for West African rocks of the pervasive Eburnean Orogenic Cycle and basement rocks at opposite locations in South America. 2) There is also a close correlation, with respect to potassium-argon age determinations on micas, rubidium-strontium determinations on total-rock samples, and the extent to which these two sets of values differ, between rocks of the Pan-African Orogenic Cycle and rocks of the Caririan Orogenic Cycle in Brazil, where these two groups of rocks lie opposite each other in the two continents. 3) When Africa and South America are "fitted together," the sharply defined boundary between the Eburnean and the Pan-African age provinces in West Africa strikes directly toward the corresponding age boundary in northeast Brazil. 4) The transition from the 550-million-year Pan-African age province to the 2000-million-year age province in the Congo Craton in Cameroun-Gabon is matched in the rocks near the corresponding part of the east coast of Brazil. However the geological and age data are insufficient to do more than suggest the possibility of another age-boundary correlation here. 5) The evidence reported here supports the hypothesis of continental drift.

  13. Reservoir sedimentology

    SciTech Connect

    Tillman, R.W.; Weber, K.J.

    1987-01-01

    Collection of papers focuses on sedimentology of siliclastic sandstone and carbonate reservoirs. Shows how detailed sedimentologic descriptions, when combined with engineering and other subsurface geologic techniques, yield reservoir models useful for reservoir management during field development and secondary and tertiary EOR. Sections cover marine sandstone and carbonate reservoirs; shoreline, deltaic, and fluvial reservoirs; and eolian reservoirs. References follow each paper.

  14. Influence of the Little Ice Age on the biological structure of lakes in South West Greenland

    NASA Astrophysics Data System (ADS)

    McGowan, S.; Hogan, E. J.; Jones, V.; Anderson, N. J.; Simpson, G.

    2013-12-01

    Arctic lakes are considered to be particularly sensitive to environmental change, with biological remains in lake sediment records being interpreted as reflecting climate forcing. However the influence that differences in catchment properties and lake morphometries have on the sedimentary record is rarely considered. We investigated sediment cores from three lakes located close to the inland ice sheet margin in the Kangerlussuaq area of South West Greenland but within a few kilometres of one another. This regional replication allowed for direct comparisons of biological change in lakes exposed to identical environmental pressures (cooling, increased wind speeds) over the past c.2000 years. Sedimentary pigments were used as a proxy for whole-lake production and to investigate differences in phytoplankton community structure whilst fossil diatom assemblages were studied to determine differences in ecological responses during this time. We noted several major effects of the Little Ice Age cooling (LIA, c. 1400-1850AD). The organic content of sediments in all three lakes declined, and this effect was most pronounced in lakes closest to the inland ice sheet margin, which suggests that aeolian inputs derived from the glacial outwash plains (sandurs), and wind-scouring of the thin catchment soils by strong katabatic winds associated with the regional cooling might have both contributed to this sedimentary change. During the LIA total algal production (as indicated by chlorophyll and carotenoid pigments) was lower in all three lakes, most likely because of extended ice-cover and shorter growing seasons, and the ratio of planktonic: benthic diatom taxa increased, possibly because of lower light availability or fertilization from loess material. Despite this coherence in lake response to the LIA, diatom community composition changes in individual lakes differed, reflecting individual lake morphometry and catchment characteristics. These findings highlight the importance of

  15. Geoscience/Engineering Characterization of the Interwell Environment in Carbonate Reservoirs Based on Outcrop Analogs, Permian Basin, West Texas and New Mexico.

    SciTech Connect

    Lucia, Jerry F.; Kerans, Charles

    1997-05-29

    The objective of this project is to investigate styles of reservoir heterogeneity found in low permeability pelleted wackestone/packstone facies and mixed carbonate/clastic facies found in Permian Basin reservoirs by studying similar facies exposed in the Guadalupe Mountains. Specific objectives for the outcrop study include construction of a stratigraphic framework, petrophysical quantification of the framework, and testing the outcrop reservoir model for effects of reservoir heterogeneity on production performance. Specific objectives for the subsurface study parallel objectives for the outcrop study. Subsurface Activities - We continue to prepare two final reports that summarize research results of the South Cowden Field study. One report summarizes results of the petrophysical characterization research, and one summarizes results of the fluid-flow modeling research. Outcrop Activities - We also continue to prepare the final report, which summarizes the research results of the Grayburg outcrop reservoir study.

  16. Geoscience/Engineering Characterization of the Interwell Environment in Carbonate Reservoirs Based on Outcrop Analogs, Permian Basin, West Texas and New Mexico.

    SciTech Connect

    Lucia, Jerry F.; Kerans, Charles

    1997-05-19

    The objective of this project is to investigate styles of reservoir heterogeneity found in low permeability pelleted wackestone/packstone facies and mixed carbonate/clastic facies found in Permian Basin reservoirs by studying similar facies exposed in the Guadalupe Mountains. Specific objectives for the outcrop study include construction of a stratigraphic framework, petrophysical quantification of the framework, and testing the outcrop reservoir model for effects of reservoir heterogeneity on production performance. Specific objectives for the subsurface study parallel objectives for the outcrop study. Subsurface Activities - We continue to prepare two final reports that summarize research results of the South Cowden Field study. One report summarizes results of the petrophysical characterization research, and one summarizes results of the fluid-flow modeling research. Outcrop Activities - We also continue to prepare the final report, which summarizes the research results of the Grayburg outcrop reservoir study.

  17. Age Dating Fluvial Sediment Storage Reservoirs to Construct Sediment Waiting Time Distributions

    NASA Astrophysics Data System (ADS)

    Skalak, K.; Pizzuto, J. E.; Benthem, A.; Karwan, D. L.; Mahan, S.

    2015-12-01

    Suspended sediment transport is an important geomorphic process that can often control the transport of nutrients and contaminants. The time a particle spends in storage remains a critical knowledge gap in understanding particle trajectories through landscapes. We dated floodplain deposits in South River, VA, using fallout radionuclides (Pb-210, Cs-137), optically stimulated luminescence (OSL), and radiocarbon dating to determine sediment ages and construct sediment waiting time distributions. We have a total of 14 age dates in two eroding banks. We combine these age dates with a well-constrained history of mercury concentrations on suspended sediment in the river from an industrial release. Ages from fallout radionuclides document sedimentation from the early 1900s to the present, and agree with the history of mercury contamination. OSL dates span approximately 200 to 17,000 years old. We performed a standard Weibull analysis of nonexceedance to construct a waiting time distribution of floodplain sediment for the South River. The mean waiting time for floodplain sediment is 2930 years, while the median is approximately 710 years. When the floodplain waiting time distribution is combined with the waiting time distribution for in-channel sediment storage (available from previous studies), the mean waiting time shifts to approximately 680 years, suggesting that quantifying sediment waiting times for both channel and floodplain storage is critical in advancing knowledge of particle trajectories through watersheds.

  18. Determinants of suboptimal complementary feeding practices among children aged 6-23 months in four anglophone West African countries.

    PubMed

    Issaka, Abukari I; Agho, Kingsley E; Page, Andrew N; Burns, Penelope L; Stevens, Garry J; Dibley, Michael J

    2015-10-01

    Suboptimal complementary feeding practices have a detrimental impact on a child's growth, health and development in the first two years of life. They lead to child malnutrition, which contributes to the high prevalence of stunting (38%) and underweight (28%) reported for children <5 years of age in Sub-Saharan Africa. This study analysed complementary feeding practices in four anglophone West African countries (Ghana, Liberia, Nigeria and Sierra Leone) using the most recent Demographic and Health Surveys. The study covered 12 623 children aged 6-23 months from four anglophone West African countries (Ghana: 822 children: Liberia: 1458 children, Nigeria: 8786 children and Sierra Leone: 1557 children). Four complementary feeding indicators were examined against a set of individual-, household- and community-level factors, using multiple regression analysis. Multivariate analyses found that lack of post-natal contacts with health workers, maternal illiteracy and geographical region were common determinants of delayed introduction of solid, semi-solid or soft foods across all four countries. Predictors for minimum dietary diversity, minimum meal frequency and minimum acceptable diet included children aged 6-11 months, administrative/geographical region, poorer household income and limited access to media. The authors recommend that the four anglophone West African countries studied should prioritise efforts to improve complementary feeding practices in order to reduce child morbidity and mortality. Interventional studies on complementary feeding should target those from poor and illiterate households. © 2015 John Wiley & Sons Ltd.

  19. Pre-bomb marine reservoir ages in the western north Pacific: Preliminary result on Kyoto University collection

    NASA Astrophysics Data System (ADS)

    Yoneda, Minoru; Kitagawa, Hiroyuki; van der Plicht, Johannes; Uchida, Masao; Tanaka, Atsushi; Uehiro, Takashi; Shibata, Yasuyuki; Morita, Masatoshi; Ohno, Terufumi

    2000-10-01

    The calibration of radiocarbon dates on marine materials involves a global marine calibration with regional corrections. The marine reservoir ages in the Western North Pacific have not been discussed, while it is quite important to determine the timing of palaeo-environmental changes as well as archaeological interpretation around this region. The lack of adequate collection of the pre-bomb shell from western north Pacific was the biggest problem. Recently we had a chance to examine specimens from an old shell collection stored in Kyoto University, including shell specimens from Japan, Korea, Taiwan and the Micronesia of 1920s and 1930s. We explored the possibility for usage of specimen without clear evidence of live collection by measuring 30 apparent radiocarbon ages of pre-bomb mollusk shells from 18 sites in Western North Pacific. The preliminary results showed several discrepancies with previously reported results and with each other. We have to carefully select the shell specimen that has biological signs such as articulating fulcrum. In order to exploit this big resource of pre-bomb shell collection, the new technique to distinguish fossils from live collected samples should be developed by using chemical and physical methods.

  20. Growth and mortality of age-0 northern squawfish, Ptychocheilus oregonensis, rearing in shoreline habitats of the Columbia River Reservoir

    USGS Publications Warehouse

    Barfoot, C.A.; Gadomski, D.M.; Wertheimer, R.H.

    1999-01-01

    We investigated growth and mortality of age-0 northern squawfish during early rearing in shallow shoreline habitats. Larvae and juveniles (n=22914) were collected by weekly seining at three sample sites in the upper John Day Reservoir, Columbia River, during June through early September 1994–1996. Using a length-based ageing method, it was estimated that the exponential growth rate (G) for a common growth stanza (10–28 mm standard length SL) was significantly higher in 1994 (G=0.047) than in 1996 (G=0.037). Growth rate in 1995 could not be estimated, but was probably intermediate between 1994 and 1996 based on mean standard lengths of fish collected at the end of each sampling season (46.3, 40.0, and 32.0 mm SL in 1994, 1995, and 1996, respectively). For many fish species, variations in early growth can influence survival through size-selective mortality processes. Consistent with this possibility, our estimates of instantaneous mortality rates (Z) demonstrated that larvae and juveniles had significantly higher mortality in 1996 than in 1994 (Z=0.103 in 1994, versus Z=0.138 in 1996). Enhanced growth and lower mortality in 1994 were associated with a number of interrelated environmental conditions – comparatively low flows and turbidities, abundant instream vegetative cover, and high near-shore water temperatures.

  1. Brain Development and the Education of Children from Birth to Age Three. West Virginia KIDS COUNT Data Book: 1997 County Profiles of Child Well-Being.

    ERIC Educational Resources Information Center

    West Virginia Kids Count Fund, Charleston.

    This sixth annual edition of the West Virginia Kids Count data book examines county and statewide trends in the well-being of West Virginia's children, focusing on brain development and educational initiatives for children from birth to 3 years of age. The statistical portrait is based on 11 well-being indicators: (1) percent low birthweight…

  2. WestPro: a computer program for simulating uneven-aged Douglas-fir stand growth and yield in the Pacific Northwest.

    Treesearch

    Rebecca Ralston; Joseph Buongiorno; Benedict Schulte; Jeremy. Fried

    2003-01-01

    WestPro is an add-in program designed to work with Microsoft Excel to simulate the growth of uneven-aged Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stands in the Pacific Northwest region of the United States. Given the initial stand state, defined as the number of softwood and hardwood trees per acre by diameter class, WestPro predicts the...

  3. Upper Intermediate Water Reservoir Ages in the Northeastern Atlantic During the Past 11000 Years: New Evidence for Mid Holocene Freshening of the North Atlantic

    NASA Astrophysics Data System (ADS)

    Frank, N.; Paterne, M.; Blamart, D.; Colin, C.; Tisnerat-Laborde, N.; van Weering, T.; Henriet, J.

    2006-12-01

    Deep-water corals such as Lophelia pertusa and Madrepora occulata construct reef like structures along the slopes of Rockall Trough and within the Porcupine Seabight between 500 and 1000m depth, so called carbonate mounds. The hydrography is complex, with upper intermediate and surface water originating in the temperate North Atlantic and water masses from the sub-polar gyre and Labrador Sea circulating at depth within the Rockall Trough. Moreover, Norwegian Sea deep-water returns southward over the sill close to Rosemary Bank and move along the western slope of Rockall Bank. In addition, strong winter mixing of up to 1000m depth causes a significant contribution of surface water at depth and vise versa. Sediment coring on carbonate mounds and subsequent U series dating of coral skeletons has revealed up to 5m thick Holocene coral reef structures. Combined U series and 14C dating on those corals allows reconstructing upper intermediate water reservoir ages almost continuously for the entire Holocene. Here we present a compilation of 40 reservoir ages from western Rockall Bank and Porcupine Seabight that span from 400 years PB to ~11000 years BP representing water masses between 610 and 750m depth. Reservoir ages vary remarkably between as low as 150 years to up to 800 years throughout the Holocene. Variable reservoir ages are recorded at the beginning of the Holocene having mean values of about 450-500 years. The Mid-Holocene warm phase between 8500 and 6000 years BP revealed stunningly small and constant reservoir ages of about 200±150 years indicating extremely well ventilated upper intermediate waters. Than reservoir ages rise towards values as high as 700 years and drop down again to about 500 years at 4000 years BP. During the past 4000 years reservoir ages remain far more stable at 450- 500 years. Such changes in upper intermediate water ventilation agree with changes in Northern Hemisphere climate and oceanography recorded by other sedimentary proxies such

  4. Integrated Outcrop and Subsurface Studies of the Interwell Environment of Carbonate Reservoirs: Clear Fork (Leonaradian Age) Reservoirs, West Texas and New Mexico

    SciTech Connect

    Lucia, F.J.; Ruppel, S.C.

    2001-02-01

    Characterization of cycle and facies architecture on lower Clear Fork and lowermost upper Clear Fork equivalent outcrops in Apache Canyon of Sierra Diablo was complete. The focus of detailed study in Apache Canyon has been the upper Clear Fork section because this interval contains the productive interval in South Wasson field, the preliminary subsurface study area. Parts of three high-frequency sequences (HFS), each 60 to 100 ft thick, are present on the south wall of Apache Canyon. HFS's display an upper-deepening or backstepping pattern associated with longer-term sea level rise. Each HFS is composed of upward-shallowing cycles whose thickness, facies composition, and continuity vary within and between HFS's.

  5. Hydrologic controls on Congo River particulate organic carbon source and reservoir age

    NASA Astrophysics Data System (ADS)

    Hemingway, J. D.; Schefuß, E.; Spencer, R. G.; Dinga, B. J.; Eglinton, T. I.; McIntyre, C.; Galy, V.

    2016-12-01

    Tropical rivers are a major source of organic matter (OM) to the coastal ocean and play a large role in the global carbon cycle. As such, it is critical to understand the sources, sinks, and transformations of OM during fluvial transit over seasonal and inter-annual timescales. Here we present dissolved organic carbon (DOC) concentrations, particulate OM (POM) composition (δ13C, δ15N, ∆14C, N/C), and glycerol dialkyl glycerol tetraether (GDGT) biomarker distributions from a 34-month time-series near the mouth of the Congo River. An end-member mixing model based on δ13C and N/C indicates that exported POM is consistently dominated by C3 tropical rainforest soil inputs, with increasing contributions by C3 tropical plant vegetation and decreasing contributions by autochthonous phytoplankton at high discharge. Calculated ∆14C values of the C3-soil end member reveal significant and variable pre-aging prior to export, especially during the year 2011 when southern-hemisphere discharge reached record lows (mean = -176‰, standard deviation = 93‰). In contrast, ∆14C values were stable near -50‰ between January and June 2013 when southern-hemisphere discharge was highest. These results indicate that headwater POM is diluted and/or overprinted by pre-aged soils during transit through the Cuvette Congolaise swamp forest, while left-bank tributaries export significantly less pre-aged material. GDGT distributions are in agreement, as the methylation and cyclization of branched tetraethers and the GDGT-0/crenarchaeol ratio reflect a significant incorporation of compounds produced in permanently inundated Cuvette Congolaise swamp-forest soils when discharge through this region is high, especially in 2011. This study provides a mechanistic link between hydrology and carbon cycling in the world's second largest tropical river and suggests that, if recent observed decreases in springtime precipitation over the Congo basin persist, future hydrologic conditions will

  6. Attitudes toward Wife Beating among Palestinian Women of Reproductive Age from Three Cities in West Bank

    ERIC Educational Resources Information Center

    Dhaher, Enas A.; Mikolajczyk, Rafael T.; Maxwell, Annette E.; Kramer, Alexander

    2010-01-01

    A total of 450 women were interviewed in Mother and Child Health Care Centers in three cities in West Bank, Palestine, to assess attitudes toward wife beating. Overall, women perceived wife beating to be justified if a wife insults her husband (59%), if she disobeys her husband (49%), if she neglects her children (37%), if she goes out without…

  7. Tracing and age-dating injected groundwater of the west basin barrier project, Los Angeles, CA

    SciTech Connect

    Davisson, M L; Eaton, Gp; Hudson, G B; Koester, C

    1999-03-26

    This preliminary report summarizes results from isotopic data recently generated on water collected for the West Basin Municipal Water District (WBMWD). Samples comprised monitoring and production wells up to 3.5 miles form the injection barrier, in addition to barrier product and blend water.

  8. Attitudes toward Wife Beating among Palestinian Women of Reproductive Age from Three Cities in West Bank

    ERIC Educational Resources Information Center

    Dhaher, Enas A.; Mikolajczyk, Rafael T.; Maxwell, Annette E.; Kramer, Alexander

    2010-01-01

    A total of 450 women were interviewed in Mother and Child Health Care Centers in three cities in West Bank, Palestine, to assess attitudes toward wife beating. Overall, women perceived wife beating to be justified if a wife insults her husband (59%), if she disobeys her husband (49%), if she neglects her children (37%), if she goes out without…

  9. Historical reconstruction of storms in the West of France in the early Little Ice Age.

    NASA Astrophysics Data System (ADS)

    Athimon, Emmanuelle; Maanan, Mohamed

    2016-04-01

    This research offers to : 1) identify, as accurately as possible, the storms and the coastal flooding in the early Little Ice Age, 2) expose their impacts on the environment and populations, 3) query the « resilience » and adaptation of medieval and modern coastal societies in the West of France by presenting their perceptions and reactions. The space-time frame of the study is located in France, from Brittany to Gascony, between the xivth and the xvith century. Sensitive and brittle, this area is regularly battered by violent winds. It also undergoes episodic sea flooding that can cause ruptures of balance. Hence, the historical reconstruction and analysis of storms and coastal flooding in a long period appear fundamental. A thorough knowledge of past meteo-marine hazards allows to recreate a link with the territory, particularly through the (re)construction of an effective memory of these phenomena. This process is essential however difficult because of many documentary gaps. They are due to historical contingencies such as wars, French Revolution, or archival disasters like the fire of the Chamber of Accounts in Paris in 1737. Many limits must also be taken into account and discussed as inaccurate dates, exaggerated or undervalued descriptions, strict spatial demarcation almost impossible to achieve for the xivth-xvith centuries. Furthermore, during this period, no death toll, material and economic balance was done after a climate disaster. Yet, many historical records - especially narrative sources, books of accounts or cities repairs - expose the impacts of storms and marine submersion on agriculture, environment, infrastructures, etc. For instance, a violent storm hit the coast on June 24th 1452. It washed away part of the roof of a castle on Noirmoutier island and knocked down the bell towers of two churches in Angers. Storms and sea flooding have affected activities, constructions and populations' lives. They have therefore forced societies to adapt

  10. The western Mediterranean basin as an aged aerosols reservoir. Insights from an old-fashioned but efficient radiotracer

    NASA Astrophysics Data System (ADS)

    Brattich, E.; Hernández-Ceballos, M. A.; Orza, J. A. G.; Bolívar, J. P.; Tositti, L.

    2016-09-01

    The long-term contemporary 210Pb time series acquired during the period 2004-2011 at two distant sites of different altitude in the Mediterranean basin, El Arenosillo (40 m a.s.l. in southwestern Spain) and Mt. Cimone (2165 m a.s.l. in northern Italy), are analyzed and compared. Besides being considered a tracer of continental air masses, 210Pb radionuclide is also a proxy of fine stable aerosol. For this reason, the measurements of PM10 mass concentrations collected at the same time and the corresponding 210Pb/PM10 ratio at the two sites are considered to gain better insights into the origin and size of the particles. Three statistical trajectory methods are applied to identify and characterize the 210Pb source regions at the two sites. The three methods yield similar outcomes in the source identification, which strengthens the robustness of our results. In addition to the importance of the transport from areas of continental Europe, this study highlights the relevant role of the Mediterranean Sea as a major 210Pb reservoir layer associated to the aged air masses that accumulate in the western Mediterranean basin. The analysis of the sources points out the significant influence of northern Africa to 210Pb increases at both sites as well, even though the most intensive episodes are not of Saharan origin.

  11. New constraints on the age and evolution of the Wishbone Ridge, southwest Pacific Cretaceous microplates, and Zealandia West Antarctica breakup

    NASA Astrophysics Data System (ADS)

    Mortimer, N.; Hoernle, K.; Hauff, F.; Palin, J. M.; Dunlap, W. J.; Werner, R.; Faure, K.

    2006-03-01

    We present analytical results from four dredge locations across the eastern Zealandia continental margin and adjacent ocean crust. The 115 Ma dacites dredged from the West Wishbone Ridge (WWR) are isotopically primitive, weakly adakitic, slab-derived lavas. The 97 Ma A-type granites and a basalt from the easternmost Chatham Rise enlarge the known area of postsubduction Gondwana magmatism. Amphibolite-grade schists from a fault block south of the Chatham Rise provide a critical bridge between the Zealandia and West Antarctica belts of Jurassic Cretaceous accretionary prism rocks. The new recognition of the WWR as a remnant of a 115 Ma intraoceanic subduction system means that previous hypotheses of the WWR as a fracture zone or spreading ridge require modification. The dacite ages constrain the start of Osbourn Trough spreading, which caused breakup of the Hikurangi-Manihiki igneous plateau, to before 115 Ma. We speculate that, after 115 Ma, the WWR was rifted by an intraoceanic spreading center that developed along its southeast side. Impingement of this spreading center against the Gondwana margin led to widespread 95 100 Ma postsubduction magmatism, variable lithospheric stretching, and ultimately continental splitting of Zealandia and West Antarctica across basement trends.

  12. Association between age at antiretroviral therapy initiation and 24-month immune response in HIV-infected children in West Africa

    PubMed Central

    Desmonde, Sophie; Dicko, Fatoumata; Koueta, Fla; Eboua, Tanoh; Balestre, Eric; Amani-Bosse, Clarisse; Aka, Edmond A.; Lawson-Evi, Koko; Amorissani-Folquet, Madeleine; Kouakou, Kouadio; Koumakpai, Siriatou; Renner, Lorna; Sy, Haby Signaté; Valériane, Leroy

    2014-01-01

    Objective We describe the association between age at antiretroviral therapy (ART) initiation and 24-month CD4+ cell response in West African HIV-infected children. Methods All HIV-infected children from the IeDEA paediatric West African cohort, initiating ART, with at least two CD4+ cell count measurements, including one at ART initiation (baseline) were included. CD4+ cell gain on ART was estimated using a multivariable linear mixed model adjusted for baseline variables: age, CD4+ cell count, sex, first-line ART regimen. Kaplan-Meier survival curves and a Cox proportional hazards regression model compared immune recovery for age within 24 months post-ART. Results Of the 4808 children initiated on ART, 3014 were enrol led at a median age of 5.6 years; 61.2% were immunodeficient. After 12 months, children at least 4 years at baseline had significantly lower CD4+ cell gains compared with children less than 2 years, the reference group (P < 0.001). However, by 24 months, we observed higher CD4+cell gain in children who initiated ART between 3 and 4 years compared with those less than 2 years (P < 0.001). The 24-month CD4+ cell gain was also strongest in immunodeficient children at baseline. Among these children, 75% reached immune recovery: 12-month rates were significantly highest in all those aged 2–5 years at ART initiation compared with those less than 2 years. Beyond 12 months on ART, immune recovery was significantly lower in children initiated more than 5 years (adjusted hazard ratio: 0.69, 95% confidence interval: 0.56–0.86). Conclusion These results suggest that both the initiation of ART at the earliest age less than 5 years and before any severe immunodeficiency is needed for improving 24-month immune recovery on ART. PMID:24804858

  13. Ageing, social class and common mental disorders: longitudinal evidence from three cohorts in the West of Scotland.

    PubMed

    Green, M J; Benzeval, M

    2011-03-01

    Understanding how common mental disorders such as anxiety and depression vary with socio-economic circumstances as people age can help to identify key intervention points. However, much research treats these conditions as a single disorder when they differ significantly in terms of their disease burden. This paper examines the socio-economic pattern of anxiety and depression separately and longitudinally to develop a better understanding of their disease burden for key social groups at different ages. The Twenty-07 Study has followed 4510 respondents from three cohorts in the West of Scotland for 20 years and 3846 respondents had valid data for these analyses. Hierarchical repeated-measures models were used to investigate the relationship between age, social class and the prevalence of anxiety and depression over time measured as scores of 8 or more out of 21 on the relevant subscale of the Hospital Anxiety and Depression Scale (HADS). Social class differences in anxiety and depression widened with age. For anxiety there was a nonlinear decrease in prevalence with age, decreasing more slowly for those from manual classes compared to non-manual, whereas for depression there was a non-linear increase in prevalence with age, increasing more quickly for those from manual classes compared to non-manual. This relationship is robust to cohort, period and attrition effects. The more burdensome disorder of depression occurs more frequently at ages where socio-economic inequalities in mental health are greatest, representing a 'double jeopardy' for older people from a manual class.

  14. New K-Ar ages for calculating end-of-shield extrusion rates at West Maui volcano, Hawaiian island chain

    USGS Publications Warehouse

    Sherrod, D.R.; Murai, T.; Tagami, Takahiro

    2007-01-01

    Thirty-seven new K-Ar ages from West Maui volcano, Hawai'i, are used to define the waning stages of shield growth and a brief episode of postshield volcanism. All but two samples from shield-stage strata have reversed polarity magnetization, so conceivably the exposed shield is not much older than the Olduvai Normal-Polarity subchron, or about 1.8 Ma. The oldest ages obtained are in the range 1.9-2.1 Ma but have large analytical error. Shield volcanism ended about 1.35 Ma, and postshield volcanism followed soon thereafter, persisting until about 1.2 Ma. Exposed shield-stage strata were emplaced at a rate of about 0.001 km3 per year, a rate smaller than historic Hawaiian magmatic rates by a factor of 100. Stratigraphic accumulation rates are similar to those measured previously at Wai'anae volcano (O'ahu) or the upper part of the Mauna Kea shield sequence (Hilo drill core, Hawai'i). These rates diminish sharply during the final 0.3-0.5 m.y. of the shield stage. Hawaiian shield volcanoes begin waning well before their last 0.5 m.y. of life, then end quickly, geologically speaking, if West Maui is representative. ?? Springer-Verlag 2006.

  15. Tree diameter a poor indicator of age in West Virginia hardwoods

    Treesearch

    Carter B. Gibbs

    1963-01-01

    Foresters generally recognize that diameter growth, height growth, sprouting vigor, and seed production are partially related to age; so age often has an important bearing upon silvicultural decisions. But unless past stand histories are fully known, the ages of hardwood trees can be determined only by increment borings, which not only require excessive time but also...

  16. Influence of the microencapsulated pheromone from aged infusion as an oviposition medium of the West Nile virus vector Culex pipiens.

    PubMed

    Michaelakis, Antonios; Mihou, Anastasia P; Koliopoulos, George; Couladouros, Elias A

    2009-04-01

    The main tendency for the control of West Nile virus vectors, without the presence of disease, is to perform integrated programs minimizing chemicals by using environmentally friendly substances which act as oviposition attractants such as oviposition pheromones and infusions. This is the first time that an aged infusion is combined with aged pheromone (microencapsulated). Initially, three common plants in Greece were evaluated as a potential oviposition medium: Oxalis pes-carpae, Jasminum polyanthum, and Avena barbata. All revealed an excellent oviposition attractancy which was more than 80%. O. pes-carpae was used for further investigation and attractancy over time was also studied. Finally, the combination of the synthetic pheromone (6-acetoxy-5-hexadecanolide) with the O. pes-carpae infusion revealed a synergistic effect only for the first day. This project was a first detection for the potential use of microencapsulated synthetic pheromone with infusion and results are discussed.

  17. Modeling the impact of a hydropower reservoir on the habitat of a megaherbivore in the Black Volta Basin in Ghana, West Africa

    NASA Astrophysics Data System (ADS)

    Manful, Desmond

    2010-05-01

    The Black Volta watershed is approximately 134 000 km2 in size at the gauge at Bamboi. It is part of the main 414 000 km2 Volta system. The Volta river was dammed at Akosombo in 1965 resulting in the largest man-made lake in the world, the Volta Lake. The Bui dam is a new 400 MW scheme currently under development on the Black Volta River in the Bui national park in Ghana. The reservoir created by the Bui barrage is expected to impact (through inundation) the habitat of two species of hippos know to exist in the park, the Hippopotamus amphibius and the Choeropsis liberiensis. Computer-based models present a unique opportunity to assess quantitatively the impact of the new reservoir on the habitat of the target species in this case the H. amphibious. Until this undertaking, there were very few studies documenting the habitat of the H. amphibious let alone model it. The work and subsequent presentation will show the development of a habitat model for the Hippopotamus amphibius. The Habitat Information retrieval Program based on Streamflow Analysis, in short HIPStrA, is a one dimensional (1D) in-stream, spatially explicit hybrid construct that combines physico-chemical evidence and expert knowledge to forecast river habitat suitability (Hs) for the Hippopotamus amphibius. The version of the model presented is specifically developed to assess the impact of a reservoir created by a hydroelectric dam on potential dwelling areas in the Bui gorge for hippos. Accordingly, this version of HIPStrA simulates a special reservoir suitability index (Rsi), a metric that captures the "hippo friendliness" of any lake or reservoir. The impact of measured and simulated flood events as well as low flows, representing extreme events is also assessed. Recommendations are made for the operating rules of the reservoir in the post-construction phase of the dam. A great deal of work has been done on the effects of stream flow changes on fish especially salmonids. Very little work however has

  18. Age-Dependent Cell Trafficking Defects in Draining Lymph Nodes Impair Adaptive Immunity and Control of West Nile Virus Infection

    PubMed Central

    Richner, Justin M.; Gmyrek, Grzegorz B.; Govero, Jennifer; Tu, Yizheng; van der Windt, Gerritje J. W.; Metcalf, Talibah U.; Haddad, Elias K.; Textor, Johannes; Miller, Mark J.; Diamond, Michael S.

    2015-01-01

    Impaired immune responses in the elderly lead to reduced vaccine efficacy and increased susceptibility to viral infections. Although several groups have documented age-dependent defects in adaptive immune priming, the deficits that occur prior to antigen encounter remain largely unexplored. Herein, we identify novel mechanisms for compromised adaptive immunity that occurs with aging in the context of infection with West Nile virus (WNV), an encephalitic flavivirus that preferentially causes disease in the elderly. An impaired IgM and IgG response and enhanced vulnerability to WNV infection during aging was linked to delayed germinal center formation in the draining lymph node (DLN). Adoptive transfer studies and two-photon intravital microscopy revealed a decreased trafficking capacity of donor naïve CD4+ T cells from old mice, which manifested as impaired T cell diapedesis at high endothelial venules and reduced cell motility within DLN prior to antigen encounter. Furthermore, leukocyte accumulation in the DLN within the first few days of WNV infection or antigen-adjuvant administration was diminished more generally in old mice and associated with a second aging-related defect in local cytokine and chemokine production. Thus, age-dependent cell-intrinsic and environmental defects in the DLN result in delayed immune cell recruitment and antigen recognition. These deficits compromise priming of early adaptive immune responses and likely contribute to the susceptibility of old animals to acute WNV infection. PMID:26204259

  19. Age-Dependent Cell Trafficking Defects in Draining Lymph Nodes Impair Adaptive Immunity and Control of West Nile Virus Infection.

    PubMed

    Richner, Justin M; Gmyrek, Grzegorz B; Govero, Jennifer; Tu, Yizheng; van der Windt, Gerritje J W; Metcalf, Talibah U; Haddad, Elias K; Textor, Johannes; Miller, Mark J; Diamond, Michael S

    2015-07-01

    Impaired immune responses in the elderly lead to reduced vaccine efficacy and increased susceptibility to viral infections. Although several groups have documented age-dependent defects in adaptive immune priming, the deficits that occur prior to antigen encounter remain largely unexplored. Herein, we identify novel mechanisms for compromised adaptive immunity that occurs with aging in the context of infection with West Nile virus (WNV), an encephalitic flavivirus that preferentially causes disease in the elderly. An impaired IgM and IgG response and enhanced vulnerability to WNV infection during aging was linked to delayed germinal center formation in the draining lymph node (DLN). Adoptive transfer studies and two-photon intravital microscopy revealed a decreased trafficking capacity of donor naïve CD4+ T cells from old mice, which manifested as impaired T cell diapedesis at high endothelial venules and reduced cell motility within DLN prior to antigen encounter. Furthermore, leukocyte accumulation in the DLN within the first few days of WNV infection or antigen-adjuvant administration was diminished more generally in old mice and associated with a second aging-related defect in local cytokine and chemokine production. Thus, age-dependent cell-intrinsic and environmental defects in the DLN result in delayed immune cell recruitment and antigen recognition. These deficits compromise priming of early adaptive immune responses and likely contribute to the susceptibility of old animals to acute WNV infection.

  20. Risk correlates of diarrhea in children under 5 years of age in slums of bankura, west bengal.

    PubMed

    Gupta, Avisek; Sarker, Gautam; Rout, Arup Jyoti; Mondal, Tanushree; Pal, Ranabir

    2015-01-01

    Diarrheal diseases are an important cause of mortality and morbidity globally in children under 5 years of age. To find the prevalence and risk factors of diarrhea among children under 5 years. A population-based analytical cross-sectional study was conducted in the urban slums of Bankura, West Bengal on the prevalence of diarrhea and feeding practices, nutrition, and immunization among 152 children under 5 years (69 males and 83 females). Overall prevalence of diarrhea was 22.36%; 21.73% males and 22.89% females were affected with diarrhea. There were 57.69% diarrhea cases in children of 7-12 months age group, followed by 25.71% in those of 13-24 months age group; with increasing age, the prevalence of diarrhea gradually decreased. Diarrhea was noted to be 20.33% in exclusively breastfed children and 31.57% in children who were breastfed for less than 6 months. In bottle-fed children, the frequency of diarrhea was 26.08%. The prevalence of diarrhea was 21.83% in completely immunized children and 30% in partially immunized children. Risk of diarrhea was 19.80% in normal participants and 27.45% in undernourished children. The present study identified a high prevalence of diarrhea in children under the age of 5 years. Findings of the study also revealed the demographic features, feeding practices, immunization practices, and nutritional status as risk factors of diarrhea, which can be tackled by effective education of the community.

  1. 4. AERIAL VIEW OF GENE WASH RESERVOIR AND GENE CAMP ...

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

    4. AERIAL VIEW OF GENE WASH RESERVOIR AND GENE CAMP LOOKING SOUTHWEST. DAM AND SPILLWAY VISIBLE IN BOTTOM OF PHOTO. - Gene Wash Reservoir & Dam, 2 miles west of Parker Dam, Parker Dam, San Bernardino County, CA

  2. VIEW OF SEGMENT OF DIKE CREATING UPPER TUMALO RESERVOIR FROM ...

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

    VIEW OF SEGMENT OF DIKE CREATING UPPER TUMALO RESERVOIR FROM TUMALO RESERVOIR. LOOKING EAST/SOUTHEAST - Tumalo Irrigation District, Tumalo Project, West of Deschutes River, Tumalo, Deschutes County, OR

  3. 14. VIEW OF AREA TO BE INUNDATED FOR EASTSIDE RESERVOIR, ...

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

    14. VIEW OF AREA TO BE INUNDATED FOR EASTSIDE RESERVOIR, LOOKING SOUTHEAST FROM OBSERVATORY HILL AT NORTH END OF WEST DAM. - Eastside Reservoir, Diamond & Domenigoni Valleys, southwest of Hemet, Hemet, Riverside County, CA

  4. 11. 'Y' CONNECTOR TO PICACHO RESERVOIR ON MAIN CANAL. VIEW ...

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

    11. 'Y' CONNECTOR TO PICACHO RESERVOIR ON MAIN CANAL. VIEW LOOKING WEST FROM MAIN CANAL - San Carlos Irrigation Project, Marin Canal, Amhurst-Hayden Dam to Picacho Reservoir, Coolidge, Pinal County, AZ

  5. 37. JL photographer, summer 1978, general view of Fairmount Reservoir ...

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

    37. JL photographer, summer 1978, general view of Fairmount Reservoir (constructed 1880s; an open reservoir for the Baldwin filtration plant. - Division Avenue Pumping Station & Filtration Plant, West 45th Street and Division Avenue, Cleveland, Cuyahoga County, OH

  6. The Dora-Maira Unit (Italian Cottian Alps): a reservoir of ornamental stones locally and worldwide employed since Roman age

    NASA Astrophysics Data System (ADS)

    Borghi, Alessandro; Cadoppi, Paola; Antonella Dino, Giovanna

    2015-04-01

    The Dora-Maira is a geological unit belonging to the Penninic Domain of the Western Alps (NW Italy), which covers over 1000 km2 from the Susa to the Maira valleys, in the inner part of the Cottian Alps. It consists of different superposed complexes made of micaschists, fine-grained gneisses, quartzites, impure and dolomitic marbles, metabasites and various types of orthogneisses deriving from metamorphic transformation, during alpine orogeny, of a Palaeozoic upper continental crust and its Mesozoic carbonate cover. Thanks to the presence of different varieties of rocks, the Dora-Maira Unit can be considered as a reservoir of ornamental stones, locally employed, since Roman age, for military and religious buildings. Furthermore, these materials were used in Piedmont region for the construction of important historical palaces (17th and 18th centuries). Several varieties of gneisses, quartzites and marbles, exploited in the past and up to now, come from the Paleozoic basement. The most famous variety of gneiss is the so called "Luserna stone", a leucocratic gneiss characterized by a mylonitic fabric deriving from highly differentiated granitoids of Permian age. The first traces of Luserna Stone exploitation arise to the medieval age in the Pellice Valley). This material was widely employed in Turin, from Savoia kingdom period up to know. The very peculiar and precious application of Luserna stone were: Royal Palace and Venaria Reale Palace, Mole Antonelliana. Recently, it has been employed for the construction of Turin Metro stations (launched in 2006). Other varieties of orthogneisses, not yet exploited, are: Borgone and Vaie Stones, Villarfocchiardo and Cumiana Stones. They were used for the realization of the columns characterising the façade of several churches in Turin and in the piers of different bridges over the Po River. Another gneiss variety, with dioritic composition, is the Malanaggio Stone employed in the Fenestrelle Fortress. As for the palaeozoic

  7. The impact of climate and reservoirs on longitudinal riverine carbon fluxes from two major watersheds in the Central and Intermontane West

    USGS Publications Warehouse

    Stackpoole, Sarah M.; Stets, Edward G.; Striegl, Robert G.

    2014-01-01

    A nested sampling network on the Colorado (CR) and Missouri Rivers (MR) provided data to assess impacts of large-scale reservoir systems and climate on carbon export. The Load Estimator (LOADEST) model was used to estimate both dissolved inorganic and organic carbon (DIC and DOC) fluxes for a total of 22 sites along the main stems of the CR and MR. Both the upper CR and MR DIC and DOC fluxes increased longitudinally, but the lower CR fluxes decreased while the lower MRs continued to increase. We examined multiple factors through space and time that help explain these flux patterns. Seasonal variability in precipitation and temperature, along with site-level concentration versus discharge relationships proved to be significant factors explaining much of the difference among sites located below reservoirs as compared to sites located in more free-flowing segments of the river. The characterization of variability in carbon exports over space and time provides a basis for understanding carbon cycling and transport within river basins affected by large reservoir systems, particular in arid-to semi-arid ecosystems.

  8. Seasonal variations in fish delta13C and delta15N in two West African reservoirs, Sélingué and Manantali (Mali): modifications of trophic links in relation to water level.

    PubMed

    Perga, Marie-Elodie; Arfi, Robert; Gerdeaux, Daniel

    2005-06-01

    Most regions in the tropics undergo high seasonal precipitation that produces cyclic patterns of riverine discharge, resulting in periods characterized by low and high water levels. Many chemical and bio-logical factors are affected by this hydrologic seasonality, and it therefore appeared to be very likely that aquatic food webs would also differ during the low and high water periods. Available carbon sources for fish are thought to be less varied during low water periods, but flooding during high water periods could bring fish into contact with a greater abundance and diversity of food sources such as terrestrial plants or the biofilms that grow on submerged terrestrial plants. At low water levels, higher fish densities may lead to more piscivory and less omnivory when compared with the high water periods. Therefore, trophic links within the fish communities may then be modified by water level changes in tropical reservoirs. To address this prediction, we performed stable isotope analyses of the most common species in Sélingué and Manantali, two large reservoirs in Mali (West Africa). Allochthonous and littoral carbon sources were shown to support fish production to a significant extent, even during low water periods. However, the allochthonous or littoral carbon contributions that sustained the top-predators production were indeed greater during the high water periods as expected. The expected higher omnivory in the high water period might have shortened the food chain when compared with the low water period. Some carnivorous fish species were shown to feed at lower trophic levels during high water periods in both reservoirs, but this was not a general pattern. Flooding did not, therefore, necessarily result in a shorter food chain when water levels were high.

  9. Why Are Middle-Aged People so Depressed? Evidence from West Germany

    ERIC Educational Resources Information Center

    Brockmann, Hilke

    2010-01-01

    Does happiness vary with age? The evidence is inconclusive. Some studies show happiness to increase with age (Diener et al. 1999; Argyle 2001). Others hold that the association is U-shaped with either highest depression rates (Mroczek and Christian 1998; Blanchflower and Oswald 2008) or highest happiness levels occurring during middle age…

  10. Why Are Middle-Aged People so Depressed? Evidence from West Germany

    ERIC Educational Resources Information Center

    Brockmann, Hilke

    2010-01-01

    Does happiness vary with age? The evidence is inconclusive. Some studies show happiness to increase with age (Diener et al. 1999; Argyle 2001). Others hold that the association is U-shaped with either highest depression rates (Mroczek and Christian 1998; Blanchflower and Oswald 2008) or highest happiness levels occurring during middle age…

  11. SMC west halo: a slice of the galaxy that is being tidally stripped?. Star clusters trace age and metallicity gradients

    NASA Astrophysics Data System (ADS)

    Dias, B.; Kerber, L.; Barbuy, B.; Bica, E.; Ortolani, S.

    2016-06-01

    Context. The evolution and structure of the Magellanic Clouds is currently under debate. The classical scenario in which both the Large and Small Magellanic Clouds (LMC, SMC) are orbiting the Milky Way has been challenged by an alternative in which the LMC and SMC are in their first close passage to our Galaxy. The clouds are close enough to us to allow spatially resolved observation of their stars, and detailed studies of stellar populations in the galaxies are expected to be able to constrain the proposed scenarios. In particular, the west halo (WH) of the SMC was recently characterized with radial trends in age and metallicity that indicate tidal disruption. Aims: We intend to increase the sample of star clusters in the west halo of the SMC with homogeneous age, metallicity, and distance derivations to allow a better determination of age and metallicity gradients in this region. Positions are compared with the orbital plane of the SMC from models. Methods: Comparisons of observed and synthetic V(B-V) colour-magnitude diagrams were used to derive age, metallicity, distance, and reddening for star clusters in the SMC west halo. Observations were carried out using the 4.1 m SOAR telescope. Photometric completeness was determined through artificial star tests, and the members were selected by statistical comparison with a control field. Results: We derived an age of 1.23 ± 0.07 Gyr and [Fe/H] = -0.87 ± 0.07 for the reference cluster NGC 152, compatible with literature parameters. Age and metallicity gradients are confirmed in the WH: 2.6 ± 0.6 Gyr/° and -0.19 ± 0.09 dex/°, respectively. The age-metallicity relation for the WH has a low dispersion in metallicity and is compatible with a burst model of chemical enrichment. All WH clusters seem to follow the same stellar distribution predicted by dynamical models, with the exception of AM-3, which should belong to the counter-bridge. Brück 6 is the youngest cluster in our sample. It is only 130 ± 40 Myr old and

  12. Geostatistical Model-Based Estimates of Schistosomiasis Prevalence among Individuals Aged ≤20 Years in West Africa

    PubMed Central

    Schur, Nadine; Hürlimann, Eveline; Garba, Amadou; Traoré, Mamadou S.; Ndir, Omar; Ratard, Raoult C.; Tchuem Tchuenté, Louis-Albert; Kristensen, Thomas K.; Utzinger, Jürg; Vounatsou, Penelope

    2011-01-01

    Background Schistosomiasis is a water-based disease that is believed to affect over 200 million people with an estimated 97% of the infections concentrated in Africa. However, these statistics are largely based on population re-adjusted data originally published by Utroska and colleagues more than 20 years ago. Hence, these estimates are outdated due to large-scale preventive chemotherapy programs, improved sanitation, water resources development and management, among other reasons. For planning, coordination, and evaluation of control activities, it is essential to possess reliable schistosomiasis prevalence maps. Methodology We analyzed survey data compiled on a newly established open-access global neglected tropical diseases database (i) to create smooth empirical prevalence maps for Schistosoma mansoni and S. haematobium for individuals aged ≤20 years in West Africa, including Cameroon, and (ii) to derive country-specific prevalence estimates. We used Bayesian geostatistical models based on environmental predictors to take into account potential clustering due to common spatially structured exposures. Prediction at unobserved locations was facilitated by joint kriging. Principal Findings Our models revealed that 50.8 million individuals aged ≤20 years in West Africa are infected with either S. mansoni, or S. haematobium, or both species concurrently. The country prevalence estimates ranged between 0.5% (The Gambia) and 37.1% (Liberia) for S. mansoni, and between 17.6% (The Gambia) and 51.6% (Sierra Leone) for S. haematobium. We observed that the combined prevalence for both schistosome species is two-fold lower in Gambia than previously reported, while we found an almost two-fold higher estimate for Liberia (58.3%) than reported before (30.0%). Our predictions are likely to overestimate overall country prevalence, since modeling was based on children and adolescents up to the age of 20 years who are at highest risk of infection. Conclusion/Significance We

  13. Evidence for the survival of the oldest terrestrial mantle reservoir.

    PubMed

    Jackson, Matthew G; Carlson, Richard W; Kurz, Mark D; Kempton, Pamela D; Francis, Don; Blusztajn, Jerzy

    2010-08-12

    Helium is a powerful tracer of primitive material in Earth's mantle. Extremely high (3)He/(4)He ratios in some ocean-island basalts suggest the presence of relatively undegassed and undifferentiated material preserved in Earth's mantle. However, terrestrial lavas with high (3)He/(4)He ratios have never been observed to host the primitive lead-isotopic compositions that are required for an early (roughly 4.5 Gyr ago) formation age. Here we show that Cenozoic-era Baffin Island and West Greenland lavas, previously found to host the highest terrestrial-mantle (3)He/(4)He ratios, exhibit primitive lead-isotope ratios that are consistent with an ancient mantle source age of 4.55-4.45 Gyr. The Baffin Island and West Greenland lavas also exhibit (143)Nd/(144)Nd ratios similar to values recently proposed for an early-formed (roughly 4.5 Gyr ago) terrestrial mantle reservoir. The combined helium-, lead- and Nd-isotopic compositions in Baffin Island and West Greenland lavas therefore suggest that their source is the most ancient accessible reservoir in the Earth's mantle, and it may be parental to all mantle reservoirs that give rise to modern volcanism.

  14. [Sociodemographic factors associated with incomplete immunization of children aged 12 to 59 months in six West African countries].

    PubMed

    Douba, Alfred; Aka, Lepri Bernadin Nicaise; Yao, Gnissan Henri Auguste; Zengbe-Acray, Pétronille; Akani, Bangaman Christian; Konan, N Guessan

    2015-01-01

    Every year, thousands of children worldwide remain unimmunized or partially immunized, especially in developing countries. It therefore appears important to examine soda-demographic factors associated with incomplete immunization of children in West Africa. The present cross-sectional study examined factors associated with incomplete immunization of children aged 12 to 59 months in Cote d'lvoire, Ghana, Burkina Faso, Mali, Guinea, and Liberia, based on Demographic and Health Surveys data. The findings of the study showed that birth at home, absence of access of mothers to media, no religion, poverty, and illiteracy were associated with incomplete immunization of children. Health officials should take these immunization status predictors into account when making policies and immunization strategies in countries included in this study in order to achieve immunization coverage targets.

  15. [Sociodemographic factors associated with incomplete immunization or children aged 12 to 59 months in six West African countries].

    PubMed

    Douba, Alfred; Aka, Lepri Bernadin Nicaise; Yao, Gnissan Henri Auguste; Zengbe-Acray, Pétronille; Akani, Bangaman Christian; Konan, N Guessan

    2015-01-01

    Every year, thousands of children in the world remain unimmunized or partially immunized, especially in developing countries. It therefore appears important to examine sociodemographic factors associated with incomplete immunization of children in West Africa. This cross-sectional study examined factors associated with incomplete immunization of children aged 12 to 59 months in Côte d'Ivoire, Ghana, Burkina Faso, Mali, Guinea, and Liberia based on Demographic and Health Survey data. The findings of the study showed that birth at home, mothers with no access to media, no religion, poverty, and illiteracy were associated with incomplete immunization of children. Health officials should take these immunization status predictors into account when developing policies and immunization strategies in countries included in this study in order to achieve immunization coverage targets.

  16. The Volta Basin Water Allocation System: assessing the impact of small-scale reservoir development on the water resources of the Volta basin, West Africa

    NASA Astrophysics Data System (ADS)

    Leemhuis, C.; Jung, G.; Kasei, R.; Liebe, J.

    2009-08-01

    In the Volta Basin, infrastructure watershed development with respect to the impact of climate conditions is hotly debated due to the lack of adequate tools to model the consequences of such development. There is an ongoing debate on the impact of further development of small and medium scale reservoirs on the water level of Lake Volta, which is essential for hydropower generation at the Akosombo power plant. The GLOWA Volta Project (GVP) has developed a Volta Basin Water Allocation System (VB-WAS), a decision support tool that allows assessing the impact of infrastructure development in the basin on the availability of current and future water resources, given the current or future climate conditions. The simulated historic and future discharge time series of the joint climate-hydrological modeling approach (MM5/WaSiM-ETH) serve as input data for a river basin management model (MIKE BASIN). MIKE BASIN uses a network approach, and allows fast simulations of water allocation and of the consequences of different development scenarios on the available water resources. The impact of the expansion of small and medium scale reservoirs on the stored volume of Lake Volta has been quantified and assessed in comparison with the impact of climate variability on the water resources of the basin.

  17. Reservoir limnology

    SciTech Connect

    Thornton, K.W.; Kimmel, B.L.; Payne, F.E.

    1990-01-01

    This book addresses reservoirs as unique ecological systems and presents research indicating that reservoirs fall into two or three highly concatenated, interactive ecological systems ranging from riverine to lacustrine or hybrid systems. Includes some controversial concepts about the limnology of reservoirs.

  18. Determinants of suboptimal complementary feeding practices among children aged 6-23 months in seven francophone West African countries.

    PubMed

    Issaka, Abukari I; Agho, Kingsley E; Page, Andrew N; Burns, Penelope L; Stevens, Garry J; Dibley, Michael J

    2015-10-01

    Suboptimal complementary feeding practices play a crucial role in the health and development of children. The objective of this research paper was to identify factors associated with suboptimal complementary feeding practices among children aged 6-23 months in seven francophone West African countries, namely, Benin, Burkina Faso, Cote d'Ivoire, Guinea, Mali, Niger and Senegal. This study covered 22 376 children aged 6-23 months from the seven countries surveyed (Benin: 3732 children; Burkina Faso: 4205 children; Cote d'Ivoire: 2109 children, Guinea: 1944 children, Mali: 3798 children, Niger: 3451 children and Senegal: 3137 children). The most recent Demographic and Health Survey datasets of the various countries were used as data sources. A set of individual-, household- and community-level factors were used to examine the four complementary feeding indicators. Multivariate analysis revealed that the youngest age bracket (6-11 months) of children, administrative/geographical region, mother's limited or non-access to the mass media, mothers' lack of contact with a health facility, rural residence, poor households and non-working mothers were the main factors associated with suboptimal complementary feeding in the countries surveyed. Our findings highlight the need to consider broader social, cultural and economic factors when designing child nutritional interventions. © 2015 John Wiley & Sons Ltd.

  19. Chemical signatures of aged Pacific marine air: Mixed layer and free troposphere as measured during PEM-West A

    NASA Astrophysics Data System (ADS)

    Gregory, G. L.; Bachmeier, A. S.; Blake, D. R.; Heikes, B. G.; Thornton, D. C.; Bandy, A. R.; Bradshaw, J. D.; Kondo, Y.

    1996-01-01

    The Pacific Ocean is one of the few remaining regions of the northern hemisphere that is relatively free of direct anthropogenic emissions. However, long-range transport of air pollutants is beginning to have a significant impact on the atmosphere over the Pacific. In September and October 1991, NASA conducted the Pacific Exploratory Mission-West A expedition to study the atmospheric chemistry and background budgets of key atmospheric trace species. Aircraft sampling centered on the northern Pacific, 0° to 40°N and 115° to 180°E. The paper summarizes the chemical signature of relatively well-aged Pacific marine air (residence time ≥10 days over the ocean). The chemical signatures show that marine air is not always devoid of continental influences. Aged marine air which circulates around the semipermanent subtropical anticyclone located off the Asian continent is influenced by infusion of continental air with anthropogenic emissions. The infusion occurs as the result of Asian outflow swept off the continent behind eastward moving cold fronts. When compared to aged marine air with a more southerly pathway, this infusion results in enhancements in the mixing ratio of many anthropogenic/continental species and typically those with lifetimes of weeks in the free troposphere. Less enhancement is seen for the short-lived species with lifetimes of a few days as infused continental emissions are depleted during transport (about a week) around the semipermanent subtropical high.

  20. Age, growth and fall diet of channel catfish in Cheat Lake, West Virginia

    USGS Publications Warehouse

    Hilling, Corbin D.; Welsh, Stuart A.; Smith, Dustin M.

    2016-01-01

    Acidification has historically impaired Cheat Lake's fish community, but recent mitigation efforts within the Cheat River watershed have improved water quality and species richness. Presently, channel catfish Ictalurus punctatus are abundant and attain desirable sizes for anglers. We evaluated the age, growth, and fall diet of the population. We collected a sample of 155 channel catfish from Cheat Lake from 5 August to 4 December 2014, a subset of which we aged (n = 148) using lapillus otoliths. We fit four growth models (von Bertalanffy, logistic, Gompertz, and power) to length-at-age data and compared models using an information theoretic approach. We collected fall diets from 55 fish sampled from 13 October to 4 December 2014. Total lengths of individuals in the sample ranged from 154 to 721 mm and ages ranged from 2 to 19 y. We AICc-selected the von Bertalanffy growth model as the best approximating model, and the power and Gompertz models also had considerable support. Diets were numerically dominated by Diptera larvae, specifically Chironomidae and Chaoboridae, while 39% of stomachs contained terrestrial food items. This study provides baseline data for management of Cheat Lake's channel catfish population. Further, this study fills a knowledge gap in the scientific literature on channel catfish, because few previously published studies have examined the population ecology of channel catfish in the Central Appalachian region.

  1. Significance of zircon U-Pb ages from the Pescadero felsite, west-central California coast ranges

    USGS Publications Warehouse

    McLaughlin, Robert J.; Moore, Diane E.; ,; Martens, UWE C.; Clark, J.C.

    2011-01-01

    Weathered felsite is associated with the late Campanian–Maastrichtian Pigeon Point Formation near Pescadero, California. Poorly exposed, its age and correlation are uncertain. Is it part of the Pigeon Point section west of the San Gregorio–Hosgri fault? Does it rest on Nacimiento block basement? Is it dextrally offset from the Oligocene Cambria Felsite, ∼185 km to the southeast? Why is a calc-alkaline hypabyssal igneous rock intrusive into the outboard accretionary prism? To address these questions, we analyzed 43 oscillatory-zoned zircon crystals from three incipiently recrystallized pumpellyite ± prehnite ± laumontite-bearing Pescadero felsite samples by sensitive high-resolution ion microprobe–reverse geometry (SHRIMP-RG) and laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) techniques. Thirty-three zircons gave late Mesozoic U-Pb ages, with single-grain values ranging from 81 to 167 Ma; ten have pre-Mesozoic, chiefly Proterozoic ages. A group of the four youngest Pescadero zircons yielded an apparent maximum igneous age of ca. 86–90 Ma. Reflecting broad age scatter and presence of partly digested sandstone inclusions, we interpret the rest of the zircons (perhaps all) as xenocrysts. Twenty-three zircons were separated and analyzed from two samples of the similar Cambria Felsite, yielding a unimodal 27 Ma U-Pb age. Clearly, the origin of the Upper Oligocene Cambria Felsite is different from that of the Upper Cretaceous Pescadero felsite; these rocks are not correlated, and do not constrain displacement along the San Gregorio–Hosgri fault. Peak ages differ slightly, but relative probability curves for Mesozoic and pre-Mesozoic Pescadero zircons compare well, for example, with abundant U-Pb age data for detrital zircons from Franciscan metaclastic strata ∼100 km to the east in the Diablo Range–San Francisco Bay area, San Joaquin Great Valley Group turbidites, Upper Cretaceous Nacimiento block Franciscan strata, and Upper

  2. 8. WEST DAM, LOOKING DUE NORTH OVER TOP OF WEST ...

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

    8. WEST DAM, LOOKING DUE NORTH OVER TOP OF WEST DAM, SHOWING RELATIONSHIP BETWEEN OUTLET TO RIGHT OF DAM, NEW PUMP PLANT BUILDING AND CANAL TO LEFT OF DAM. - Eastside Reservoir, Diamond & Domenigoni Valleys, southwest of Hemet, Hemet, Riverside County, CA

  3. Relatively benign sickle-cell anaemia in 60 patients aged over 30 in the West Indies.

    PubMed

    Serjeant, G R; Richards, R; Barbor, P R; Milner, P F

    1968-07-13

    A study in Jamaica of 60 patients with sickle-cell anaemia over the age of 30 years showed that most of them were in full-time employment. Pains in the bones or joints, leg ulceration, and jaundice were the most frequent types of presentation, but only two patients had a haemoglobin level consistently below 6 g./ 100 ml. Most of the patients were well developed and of average height, and, though the development of secondary sexual characteristics was delayed, there was an average of 2.6 pregnancies per patient. These findings suggest that the course is more benign than has been realized.

  4. The age of infection with varicella-zoster virus in St Lucia, West Indies.

    PubMed Central

    Garnett, G. P.; Cox, M. J.; Bundy, D. A.; Didier, J. M.; St Catharine, J.

    1993-01-01

    Sera from an age-stratified sample of 1810 people from the Caribbean island of St Lucia were tested for antibodies against varicella-zoster virus. The results indicate that very few infections occur in childhood, which agrees with clinical survey data from other tropical countries, but contrasts with the observed high case rate in children in temperate countries. The alternative hypotheses which may explain these results are discussed, and it is suggested that high ambient temperatures interfere with the transmission of the virus. Irrespective of the cause, the pattern of varicella incidence observed has important implications for any vaccination policy adopted in tropical countries. PMID:8386097

  5. Using an independent geochronology based on palaeomagnetic secular variation (PSV) and atmospheric Pb deposition to date Baltic Sea sediments and infer 14C reservoir age

    NASA Astrophysics Data System (ADS)

    Lougheed, Bryan C.; Snowball, Ian; Moros, Matthias; Kabel, Karoline; Muscheler, Raimund; Virtasalo, Joonas J.; Wacker, Lukas

    2012-05-01

    Dating of sediment cores from the Baltic Sea has proven to be difficult due to uncertainties surrounding the 14C reservoir age and a scarcity of macrofossils suitable for dating. Here we present the results of multiple dating methods carried out on cores in the Gotland Deep area of the Baltic Sea. Particular emphasis is placed on the Littorina stage (8 ka ago to the present) of the Baltic Sea and possible changes in the 14C reservoir age of our dated samples. Three geochronological methods are used. Firstly, palaeomagnetic secular variations (PSV) are reconstructed, whereby ages are transferred to PSV features through comparison with varved lake sediment based PSV records. Secondly, lead (Pb) content and stable isotope analysis are used to identify past peaks in anthropogenic atmospheric Pb pollution. Lastly, 14C determinations were carried out on benthic foraminifera (Elphidium spec.) samples from the brackish Littorina stage of the Baltic Sea. Determinations carried out on smaller samples (as low as 4 μg C) employed an experimental, state-of-the-art method involving the direct measurement of CO2 from samples by a gas ion source without the need for a graphitisation step - the first time this method has been performed on foraminifera in an applied study. The PSV chronology, based on the uppermost Littorina stage sediments, produced ten age constraints between 6.29 and 1.29 cal ka BP, and the Pb depositional analysis produced two age constraints associated with the Medieval pollution peak. Analysis of PSV data shows that adequate directional data can be derived from both the present Littorina saline phase muds and Baltic Ice Lake stage varved glacial sediments. Ferrimagnetic iron sulphides, most likely authigenic greigite (Fe3S4), present in the intermediate Ancylus Lake freshwater stage sediments acquire a gyroremanent magnetisation during static alternating field (AF) demagnetisation, preventing the identification of a primary natural remanent magnetisation for

  6. Prevalence of anaemia and associated factors among children below five years of age in Cape Verde, West Africa.

    PubMed

    Semedo, Rosa M L; Santos, Marta M A S; Baião, Mirian R; Luiz, Ronir R; da Veiga, Gloria V

    2014-12-01

    This study estimated the prevalence of anaemia and associated factors in a probability sample of 993 chil- dren aged 6-59 months in Cape Verde, West Africa. Odds ratio (OR) and 95% confidence interval (95% CI) were estimated from a hierarchical model for multiple analysis to assess the association between anaemia and explanatory variables. The prevalence of anaemia was 51.8% (95% CI 47.7-55.8). Children who resided within poor household conditions (OR 1.99; 95% CI 1.06-3.71) were below 24 months of age (OR 3.23; 95% CI 2.03-5.15) and recently experienced diarrhoea (OR 1.58; 95% CI 0.99-2.50) were at high risk of anaemia. Anaemia should be considered a serious public-health concern in Cape Verde, mainly for chil- dren below 24 months. Further, special consideration should be given to children who have experienced recent diarrhoea and belong to families residing in poor household conditions.

  7. Prevalence of Anaemia and Associated Factors among Children below Five Years of Age in Cape Verde, West Africa

    PubMed Central

    Semedo, Rosa M.L.; Santos, Marta M.A.S.; Baião, Mirian R.; Luiz, Ronir R.

    2014-01-01

    ABSTRACT This study estimated the prevalence of anaemia and associated factors in a probability sample of 993 children aged 6-59 months in Cape Verde, West Africa. Odds ratio (OR) and 95% confidence interval (95% CI) were estimated from a hierarchical model for multiple analysis to assess the association between anaemia and explanatory variables. The prevalence of anaemia was 51.8% (95% CI 47.7-55.8). Children who resided within poor household conditions (OR 1.99; 95% CI 1.06-3.71) were below 24 months of age (OR 3.23; 95% CI 2.03-5.15) and recently experienced diarrhoea (OR 1.58; 95% CI 0.99-2.50) were at high risk of anaemia. Anaemia should be considered a serious public-health concern in Cape Verde, mainly for children below 24 months. Further, special consideration should be given to children who have experienced recent diarrhoea and belong to families residing in poor household conditions. PMID:25895198

  8. Lithology, age and structure of early proterozoic greenstone belts, West African shield

    NASA Technical Reports Server (NTRS)

    Attoh, K.

    1986-01-01

    Lithologic and chemical data have been compiled for belts in the Proterozoic terrane. Available stratigraphic information from geologic maps of these areas indicate that a typical sequence is comprised of predominately mafic lava flows (basalt-andesite) at the base, which are overlain by felsic volcanic rocks including pyroclastic rocks and lavas. Lithostratigraphic data indicate the volcanic succession is 6-8 km thick. This is followed by 3-4 km of basaltic lava flows which are locally pillowed, the top of the unit is marked by a distinctive manganese formation (MF) consisting of Mn-Fe rich cherts up to 200 m thick. The youngest volcanic unit consists of mafic tuffs and breccia with a distinctive fragmental texture. Of about 100 chemical analyses reported calc-alkaline rocks constitute 55% and tholeiites 45%. Quartz-normative basalt constitutes 99% of the rock type in the tholeiitic suite. In the calc-alkaline suite, 9% of the analyses is basalt, 45% andesite and the rest is dacite and rhyodacite. The available data lead to the conclusion that the minimum age for the volcanic activity must be between 2200 and 2100 million years. It is significant that Archean ages have not been reported from any of the volcanic belts (1-10).

  9. West Nile virus monitoring in migrating and resident water birds in Iran: are common coots the main reservoirs of the virus in wetlands?

    PubMed

    Fereidouni, Sasan R; Ziegler, Ute; Linke, Sonja; Niedrig, Matthias; Modirrousta, Hossein; Hoffmann, Bernd; Groschup, Martin H

    2011-10-01

    A molecular and serological study was carried out to determine the West Nile virus (WNV) status in different species of wild water birds. From 2003 to 2007, samples were collected from 519 birds representing 26 different species in Iran. Out of 519 serum samples tested for WNV antibodies, 78 (15%) were positive when tested using virus neutralization and immunofluorescence. Antibodies of WNV were detected in 71 out of 131 common coot (Fulica atra) samples. In comparison, only 7 out of 388 birds that were belonged to 25 other species of water birds revealed positive results. For most Anatidae species, no positive duck in serological tests was found. Further, no WNV viral RNA-positive samples were found in this study. Results of this investigation provide important information about the prevalence of WNV in wild water birds in Iran and indicate the potential role and importance of common coots in ecology of WNVs.

  10. 20 years of intensive uneven-aged management: Effect on Growth, Yield, and Species Composition in Two hardwood Stands in West Virginia

    Treesearch

    George R., Jr. Trimble; George R. Trimble

    1970-01-01

    In 1948 a study of uneven-aged forest management, with individual tree-selection cuttings, was begun on two 31-acre stands of Appalachian hardwoods in West Virginia. Now, after 20 years, these stands are beginning to show how this kind of management affects growth, yield, and species composition.

  11. Age and Construction of Little Ambergris Cay Bedrock Rim, Southeastern Caicos Platform, British West Indies

    NASA Astrophysics Data System (ADS)

    Orzechowski, E. A.; Strauss, J. V.; Knoll, A. H.; Fischer, W. W.; Cantine, M.; Metcalfe, K.; Quinn, D. P.; Stein, N.; Gomes, M. L.; Grotzinger, H. M.; Lingappa, U.; O'Reilly, S. S.; Riedman, L. A.; Trower, L.; Grotzinger, J. P.

    2016-12-01

    The Caicos Platform's interior-platform ooid shoals and patch reef environments are unique modern examples of grain-rich carbonate settings. In July 2016, the Agouron Institute's Advanced Geobiology field course conducted a detailed study of Little Ambergris Cay, in the southeastern sector of the platform. The cay is fringed by a topographically high rim formed of amalgamated ridges of partially lithified fossiliferous grainstone and rudstone (i.e. beachrock conglomerate), that protects an interior basin dominated by microbial mats and mangroves. Tidal channels exchanging open platform waters with the interior basin breach the rim locally. We sampled and mapped the rim (using differential GPS) in order to examine its age, sedimentological characteristics, and faunal composition. Strata up to 2 meters above the present-day high tide mark form the rim, characterized by several carbonate lithofacies, including oolites with keystone vugs, high-angle trough cross bedding, seaward-dipping low angle stratification, bioturbation and fossiliferous lags, and rudstones composed of imbricated beachrock boulders. We interpret these facies as an upper shoreface to foreshore depositional setting dominated by local storm and eolian deposits. A distinct fossiliferous rudstone facies is dominated by mytilid bivalves, as well as Eustrombus, Conus, Oliva, and vermetid gastropods. X-ray powder diffraction analyses on fossil shells reveal both shells with pristine aragonite and shells with evidence of secondary calcite. Radiometric analyses of pristine aragonite material provide additional age constraints on these deposits. Understanding the formation of Little Ambergris Cay's bedrock deposits will provide important context for the island's geological history and geomorphology, aiding in our understanding of modern analogues for ancient interior platform depositional environments.

  12. Radiocarbon content of pre-bomb marine mollusks and variations in the 14C Reservoir age for coastal areas of the Barents and Kara Seas, Russia

    NASA Astrophysics Data System (ADS)

    Forman, Steven L.; Polyak, Leonid

    Fourteen mollusks, collected alive between 1900 and 1945 from the Russian Barents and Kara seas, were analyzed by AMS 14C dating to evaluate variations in the 14C marine reservoir for arctic coastal sites, which is important for correcting ages in paleoenvironmental time-series and advancing understanding of the exchange of carbon. The 14C ages on the mollusks reveal a range of marine reservoir values (R(t)) from 159 14C yr to 764 14C yr. The oldest R(t) values of 764 to 620 14C yr are for the bivalve Portlandia arctica, which often inhabit cold and low salinity waters and muddy substrates. The depleted 14C content for this bivalve reflects possibly the incorporation of old carbon from freshwater inputs and/or the consumption of old organic matter from the underlying sediments and pore waters. Other mollusks with sessile habitats and pelagic food sources gave significantly lower R(t) values between 159 and 344 14C yr. The youngest R(t) values indicate enrichment in 14C and may partially reflect enhanced transfer of 14C-enriched CO2 from the atmosphere to the ocean surface with wind-generated wave agitation. This study underscores that a variety of processes can lead to variable 14C depletion and enrichment of surface waters yielding a ca. 600 year age span for contemporaneous arctic mollusks. There may be added uncertainty in the 14C reservoir correction for deposit-feeder species such as Portlandia sp. and perhaps for certain benthic foraminifera (e.g. Nonion labradoricum) because these taxa often incorporate old organic matter from the substrate. A reservoir correction of ≥700 years may be more appropriate for infaunal, deposit-eater species, particularly in glacier-dominated environments. Mollusks and foraminifera with sessile habits and pelagic food sources should be selected preferentially for 14C dating, because their shells may more closely reflect the 14C content of the global-ocean mixed layer.

  13. Collection, analysis, and age-dating of sediment cores from 56 U.S. lakes and reservoirs sampled by the U.S. Geological Survey, 1992-2001

    USGS Publications Warehouse

    Van Metre, Peter; Wilson, Jennifer T.; Fuller, Christopher C.; Callender, Edward; Mahler, Barbara J.

    2004-01-01

    The U.S. Geological Survey Reconstructed Trends National Synthesis study collected sediment cores from 56 lakes and reservoirs between 1992 and 2001 across the United States. Most of the sampling was conducted as part of the National Water-Quality Assessment (NAWQA) Program. The primary objective of the study was to determine trends in particle-associated contaminants in response to urbanization; 47 of the 56 lakes are in or near one of 20 U.S. cities. Sampling was done with gravity, piston, and box corers from boats and push cores from boats or by wading, depending on the depth of water and thickness of sediment being sampled. Chemical analyses included major and trace elements, organochlorine pesticides, polychlorinated biphenyls, polycyclic aromatic hydrocarbons, cesium-137, and lead-210. Age-dating of the cores was done on the basis of radionuclide analyses and the position of the pre-reservoir land surface in the reservoir and, in a few cases, other chemical or lithologic depth-date markers. Dates were assigned in many cores on the basis of assumed constant mass accumulation between known depth-date markers. Dates assigned were supported using a variety of other date markers including first occurrence and peak concentrations of DDT and polychlorinated biphenyls and peak concentration of lead. A qualitative rating was assigned to each core on the basis of professional judgment to indicate the reliability of age assignments. A total of 122 cores were collected from the 56 lakes and age dates were assigned to 113 of them, representing 54 of the 56 lakes. Seventy-four of the 122 cores (61 percent) received a good rating for the assigned age dates, 28 cores (23 percent) a fair rating, and 11 cores (9 percent) a poor rating; nine cores (7 percent) had no dates assigned. An analysis of the influence of environmental factors on the apparent quality of age-dating of the cores concluded that the most important factor was the mass accumulation rate (MAR) of sediment: the

  14. Collection, analysis, and age-dating of sediment cores from 56 U.S. lakes and reservoirs sampled by the U.S. Geological Survey, 1992-2001

    USGS Publications Warehouse

    Van Metre, Peter; Wilson, Jennifer T.; Fuller, Christopher C.; Callender, Edward; Mahler, Barbara J.

    2004-01-01

    The U.S. Geological Survey Reconstructed Trends National Synthesis study collected sediment cores from 56 lakes and reservoirs between 1992 and 2001 across the United States. Most of the sampling was conducted as part of the National Water-Quality Assessment (NAWQA) Program. The primary objective of the study was to determine trends in particle-associated contaminants in response to urbanization; 47 of the 56 lakes are in or near one of 20 U.S. cities. Sampling was done with gravity, piston, and box corers from boats and push cores from boats or by wading, depending on the depth of water and thickness of sediment being sampled. Chemical analyses included major and trace elements, organochlorine pesticides, polychlorinated biphenyls, polycyclic aromatic hydrocarbons, cesium-137, and lead-210. Age-dating of the cores was done on the basis of radionuclide analyses and the position of the pre-reservoir land surface in the reservoir and, in a few cases, other chemical or lithologic depth-date markers. Dates were assigned in many cores on the basis of assumed constant mass accumulation between known depth-date markers. Dates assigned were supported using a variety of other date markers including first occurrence and peak concentrations of DDT and polychlorinated biphenyls and peak concentration of lead. A qualitative rating was assigned to each core on the basis of professional judgment to indicate the reliability of age assignments. A total of 122 cores were collected from the 56 lakes and age dates were assigned to 113 of them, representing 54 of the 56 lakes. Seventy-four of the 122 cores (61 percent) received a good rating for the assigned age dates, 28 cores (23 percent) a fair rating, and 11 cores (9 percent) a poor rating; nine cores (7 percent) had no dates assigned. An analysis of the influence of environmental factors on the apparent quality of age-dating of the cores concluded that the most important factor was the mass accumulation rate (MAR) of sediment: the

  15. Climate variations, soil conservation and reservoir sedimentation

    USDA-ARS?s Scientific Manuscript database

    The integrated effects of soil conservation and a wetter climate on reservoir sedimentation were investigated for the Fort Cobb Reservoir watershed in west-central Oklahoma. A 12% wetter climate since the mid-1980s led to an increase in soil erosion and downstream sediment yield that offset the redu...

  16. The West African Mauritanid metamorphic suite of Proterozoic age in the subsurface of peninsular Florida and environs

    SciTech Connect

    Winston, G.O.

    1993-03-01

    A high and low-grade Gondwanan metamorphic terrane is revealed by 14 wells in Florida and environs. Two high-grade metamorphics (gneiss and schist) are located in central Florida and are probably Early Proterozoic in age. The 12 other wells contain low-grade metamorphic suites, principally composed of inter-bedded argillites, acid volcanics and quartzites belonging to the Mauritanid sequence of West Africa. These suites are present in south Georgia, north Florida and offshore; a 3,975-foot section was penetrated in one well. These widespread metamorphic rocks are probably the terrane into which the Cambrian Osceola granite of central Florida was intruded. The two grades of metamorphics represent Early and Late Proterozoic episodes of sedimentation, each followed by metamorphism and erosion. Lower Ordovician to Devonian sediments were deposited on this terrane in southern Georgia and northern Florida. In the Early Jurassic, volcanics completely covered southern Florida, concealing the nature of the old underlying surface. Younger Mesozoic sediments eventually buried the entire Pre-Cambrian-Lower Jurassic terrane.

  17. Hair chemical element contents and influence factors of reproductive-age women in the West Ujimqin Banner, Inner Mongolia, China.

    PubMed

    Zhou, Shanshan; Yuan, Haodong; Ma, Xiaoling; Liu, Ying

    2017-01-01

    Women have an increased risk for chemical element deficiencies during reproductive age, particularly due to higher chemical element requirements and poor diets. Twenty-one chemical elements (Al, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Pb, Se, Si, Sn, Sr, Ti, V and Zn) in hair samples, which were collected from 71 non-pregnant and 236 pregnant women living in the West Ujimqin Banner, central Inner Mongolia, China, were measured, and the environment, dietary habits and ethnic group influence factors associated with the biomarker were analyzed. The results indicated that the average values of the chemical element contents from hair were greatly different compared to those from other areas, especially the Al, Cd, Pb, Ca and Sr contents. There was no significant difference among the three ethnicities for any element except Mn and Ti in non-pregnant women. Compared to non-pregnant women, in the first trimester group, the levels of nine chemical elements (Ba, Cd, Cu, Pb, Se, Si, Sn and Ti) decreased, while the others increased, and the contents of all of the chemical elements decreased in the second trimester group, while in the third trimester, there was a slight increase. Three chemical elements (Cu, Mn and Zn) displayed a synergistic correlation between each other in the third trimester group, which may protect the placenta from some oxidant damage. The high levels of Cd and Pb in hair likely originate from house renovations and traffic pollution. This study provided basic and useful information on the levels of chemical elements in reproductive-age women, and the results of this study are helpful to control the contents and improve the health of pregnant and non-pregnant women.

  18. 10Be dating reveals early-middle Holocene age of the Drygalski Moraines in central West Greenland

    NASA Astrophysics Data System (ADS)

    Cronauer, Sandra L.; Briner, Jason P.; Kelley, Samuel E.; Zimmerman, Susan R. H.; Morlighem, Mathieu

    2016-09-01

    We reconstruct the history of the Greenland Ice Sheet margin on the Nuussuaq Peninsula in central West Greenland through the Holocene using lake sediment analysis and cosmogenic 10Be exposure dating of the prominent Drygalski Moraines. Erratics perched on bedrock outboard of the Drygalski Moraines constrain local deglaciation to ∼9.9 ± 0.6 ka (n = 2). Three Drygalski Moraine crests yield mean 10Be ages of 8.6 ± 0.4 ka (n = 2), 8.5 ± 0.2 ka (n = 3), and 7.6 ± 0.1 ka (n = 2) from outer to inner. Perched erratics between the inner two moraines average 7.8 ± 0.1 ka (n = 2) and are consistent with the moraine ages. Sediments from a proglacial lake with a catchment area extending an estimated 2 km beneath (inland of) the present ice sheet terminus constrain an ice sheet minimum extent from 5.4 ka to 0.6 ka. The moraine chronology paired with the lake sediment stratigraphy reveals that the ice margin likely remained within ∼2 km of its present position from ∼9.9 to 5.4 ka. This unexpected early Holocene stability, preceded by rapid ice retreat and followed by minimum ice extent between ∼5.4 and 0.6 ka, contrasts with many records of early Holocene warmth and the Northern Hemisphere summer insolation maximum. We suggest ice margin stability may instead be tied to adjacent ocean temperatures, which reached an optimum in the middle Holocene.

  19. Seismic Determination of Reservoir Heterogeneity: Application to the Characterization of Heavy Oil Reservoirs

    SciTech Connect

    Imhof, Matthias G.; Castle, James W.

    2003-03-12

    The objective of the project was to examine how seismic and geologic data could be used to improve characterization of small-scale heterogeneity and their parameterization in reservoir models. The study was performed at West Coalinga Field in California.

  20. 9. SOUTH END OF GENE PUMPING STATION LOOKING WEST WITH ...

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

    9. SOUTH END OF GENE PUMPING STATION LOOKING WEST WITH DELIVERY LINES IN BACKGROUND. - Gene Pump Plant, South of Gene Wash Reservoir, 2 miles west of Whitsett Pump Plant, Parker Dam, San Bernardino County, CA

  1. Deglacial 14C plateau suites recalibrated by Suigetsu atmospheric 14C record - Revised 14C reservoir ages from three ocean basins corroborate extreme surface water variations

    NASA Astrophysics Data System (ADS)

    Sarnthein, M.; Balmer, S.; Grootes, P. M.

    2013-12-01

    Radiocarbon (14C) reservoir/ventilation ages (Δ14C) provide unique insights into the dynamics of ocean water masses over LGM and deglacial times. The 14C plateau-tuning technique enables us to derive both an absolute chronology for marine sediment records and a high-resolution record of changing Δ14C values for deglacial surface and deep waters (Sarnthein et al., 2007; AGU Monogr. 173, 175). We designate as 14C plateau a sediment section in the age-depth profile with several almost constant planktic 14C ages - variation less than ×100 to ×300 yr - which form a plateau-shaped scatter band that extends over ~5 to 50 and up to 200 cm in sediment cores with sedimentation rates of >10 cm/ky. Previously, a suite of >15 plateau boundary ages were calibrated to a joint reference record of U/Th-dated 14C time series measured on coral samples, the Cariaco sediment record, and speleothems (Fairbanks et al., 2005, QSR 24; Hughen et al., 2006, QSR 25; Beck et al., 2001, Science 292). We now used the varve-counted atmospheric 14C record of Lake Suigetsu (Ramsey et al., 2012, Science 338, 370) to recalibrate the boundary ages and average ages of 14C plateaus and apply the amended plateau-tuning technique to a dozen Δ14C records from the Atlantic and Indo-Pacific. Main results are: (1) The Suigetsu atmospheric 14C record reflects all 14C plateaus, their internal structures and relative length previously identified, but implies a rise in the average plateau age by <200 14C yr during the LGM, >700 yr at its end, and <200 yr in the Bølling-Allerød. (2) Based on different 14C ages of coeval atmospheric and planktic 14C plateaus surface water Δ14C may have temporarily dropped to an equivalent of 200 yr in low-latitude stratified waters, such as off northwestern South America, and in turn reached values corresponding to an age difference of >2500 14C yr in stratified subpolar regions and upwelled waters such as in the South China Sea, values that differ significantly from a

  2. Associated terrestrial and marine fossils in the late-glacial Presumpscot Formation, southern Maine, USA, and the marine reservoir effect on radiocarbon ages

    USGS Publications Warehouse

    Thompson, W.B.; Griggs, C.B.; Miller, N.G.; Nelson, R.E.; Weddle, T.K.; Kilian, T.M.

    2011-01-01

    Excavations in the late-glacial Presumpscot Formation at Portland, Maine, uncovered tree remains and other terrestrial organics associated with marine invertebrate shells in a landslide deposit. Buds of Populus balsamifera (balsam poplar) occurred with twigs of Picea glauca (white spruce) in the Presumpscot clay. Tree rings in Picea logs indicate that the trees all died during winter dormancy in the same year. Ring widths show patterns of variation indicating responses to environmental changes. Fossil mosses and insects represent a variety of species and wet to dry microsites. The late-glacial environment at the site was similar to that of today's Maine coast. Radiocarbon ages of 14 tree samples are 11,907??31 to 11,650??5014C yr BP. Wiggle matching of dated tree-ring segments to radiocarbon calibration data sets dates the landslide occurrence at ca. 13,520+95/??20calyr BP. Ages of shells juxtaposed with the logs are 12,850??6514C yr BP (Mytilus edulis) and 12,800??5514C yr BP (Balanus sp.), indicating a marine reservoir age of about 1000yr. Using this value to correct previously published radiocarbon ages reduces the discrepancy between the Maine deglaciation chronology and the varve-based chronology elsewhere in New England. ?? 2011 University of Washington.

  3. West Hackberry Tertiary Project

    SciTech Connect

    Kenneth Haley; Travis Gillham; Demetrios Yannimaras

    1999-03-31

    The West Hackberry Tertiary Project is a field test of the concept that air injection can be combined with the Double Displacement Process to produce a tertiary recovery process that is both low cost and economic at current oil prices. The Double Displacement Process is the gas displacement of a water invaded oil column for the purpose of recovering tertiary oil by gravity drainage. In reservoirs with pronounced bed dip such as those found in West Hackberry and other Gulf Coast salt dome fields, reservoir performance has shown that gravity drainage recoveries average 80% to 90% of the original oil in place while waterdrive recoveries average 50% to 60% of the original oil in place. The target for tertiary oil recovery in the Double Displacement Process is the incremental oil between the 50% to 60% waterdrive recoveries and the 80% to 90% gravity drainage recoveries. In previous field tests, the Double Displacement Process has proven successful in generating tertiary oil recovery. The use of air injection in this process combines the benefits of air's low cost and universal accessibility with the potential for accelerated oil recovery from the combustion process. If successful, this project will demonstrate that utilizing air injection in the Double Displacement Process will result in an economically viable tertiary process in reservoirs (such as Gulf Coast salt dome reservoirs) where any other tertiary process is presently uneconomic. Air injection on the West Hank began in November of 1994. Although West Flank air injection has increased reservoir pressure by 500 pounds per square inch (psi), production response has not yet occurred. The gas cap on the West Flank has not expanded sufficiently to push the oil rim down to the nearest down structure well. Cumulative injection to date is 1.6 BCF, only approximately 50% of the projected volume required to establish oil production response. Additional air injection is required to further expand the gas cap and thereby

  4. The influence of theory on the formation of the infirmary during antiquity and the Middle Ages in the West

    PubMed Central

    Drampalos, Efstathios; Stogiannos, Vasileios; Psyllakis, Panagiotis; Sadiq, Mohammad; Michos, Ioannis

    2014-01-01

    The modern infirmary is the evolutional product of the dialectic interface between medical theories at each time and the outcome of their application in clinical practice. The infirmary as we know it today did not exist during antiquity, but the different precursors of the modern hospital emerged as a result of the interaction between medical theory and practice. During antiquity the Hippocratic work decisively contributed to the creation of the Asklipieion, an institution with predetermined structure created to heal diseases. Later in antiquity new types of infirmaries appeared along with the evolution of private practice for physicians. Establishment of the first modern hospitals was an outstanding contribution of Islamic medicine during reign of the Islamic Empire. Although there was little progress in the development of medical theory in medieval West, evolution of the infirmary continued and was mostly influenced by Christian religion and charity. In Constantinople large medieval infirmaries were built, but patient care was frequently offered in monasteries by clergymen. Later on medicine and treatment of diseases were taken over by physicians and taught in universities, and medical theory continued on its course of evolution. It is obvious that the modern infirmary is not only a place for treating diseases, but rather the upshot of a series of advancements in science, the relations between people or even countries, and the way humanity perceives its nature and the future. Our research is focused on the interactive relationship between the evolution of medical theory and the infirmary as an institution during antiquity and the Middle Ages with particular emphasis on the Western World. PMID:26587201

  5. WestProPlus: a stochastic spreadsheet program for the management of all-aged Douglas-fir–hemlock forests in the Pacific Northwest.

    Treesearch

    Jingjing Liang; Joseph Buongiorno; Robert A. Monserud

    2006-01-01

    WestProPlus is an add-in program developed to work with Microsoft Excel to simulate the growth and management of all-aged Douglas-fir–western hemlock (Pseudotsuga menziesii (Mirb.) Franco–Tsuga heterophylla (Raf.) Sarg.) stands in Oregon and Washington. Its built-in growth model was calibrated from 2,706 permanent plots in the...

  6. MtDNA Haplogroup A10 Lineages in Bronze Age Samples Suggest That Ancient Autochthonous Human Groups Contributed to the Specificity of the Indigenous West Siberian Population.

    PubMed

    Pilipenko, Aleksandr S; Trapezov, Rostislav O; Zhuravlev, Anton A; Molodin, Vyacheslav I; Romaschenko, Aida G

    2015-01-01

    The craniometric specificity of the indigenous West Siberian human populations cannot be completely explained by the genetic interactions of the western and eastern Eurasian groups recorded in the archaeology of the area from the beginning of the 2nd millennium BC. Anthropologists have proposed another probable explanation: contribution to the genetic structure of West Siberian indigenous populations by ancient human groups, which separated from western and eastern Eurasian populations before the final formation of their phenotypic and genetic features and evolved independently in the region over a long period of time. This hypothesis remains untested. From the genetic point of view, it could be confirmed by the presence in the gene pool of indigenous populations of autochthonous components that evolved in the region over long time periods. The detection of such components, particularly in the mtDNA gene pool, is crucial for further clarification of early regional genetic history. We present the results of analysis of mtDNA samples (n = 10) belonging to the A10 haplogroup, from Bronze Age populations of West Siberian forest-steppe (V-I millennium BC), that were identified in a screening study of a large diachronic sample (n = 96). A10 lineages, which are very rare in modern Eurasian populations, were found in all the Bronze Age groups under study. Data on the A10 lineages' phylogeny and phylogeography in ancient West Siberian and modern Eurasian populations suggest that A10 haplogroup underwent a long-term evolution in West Siberia or arose there autochthonously; thus, the presence of A10 lineages indicates the possible contribution of early autochthonous human groups to the genetic specificity of modern populations, in addition to contributions of later interactions of western and eastern Eurasian populations.

  7. MtDNA Haplogroup A10 Lineages in Bronze Age Samples Suggest That Ancient Autochthonous Human Groups Contributed to the Specificity of the Indigenous West Siberian Population

    PubMed Central

    Pilipenko, Aleksandr S.; Trapezov, Rostislav O.; Zhuravlev, Anton A.; Molodin, Vyacheslav I.; Romaschenko, Aida G.

    2015-01-01

    Background The craniometric specificity of the indigenous West Siberian human populations cannot be completely explained by the genetic interactions of the western and eastern Eurasian groups recorded in the archaeology of the area from the beginning of the 2nd millennium BC. Anthropologists have proposed another probable explanation: contribution to the genetic structure of West Siberian indigenous populations by ancient human groups, which separated from western and eastern Eurasian populations before the final formation of their phenotypic and genetic features and evolved independently in the region over a long period of time. This hypothesis remains untested. From the genetic point of view, it could be confirmed by the presence in the gene pool of indigenous populations of autochthonous components that evolved in the region over long time periods. The detection of such components, particularly in the mtDNA gene pool, is crucial for further clarification of early regional genetic history. Results and Conclusion We present the results of analysis of mtDNA samples (n = 10) belonging to the A10 haplogroup, from Bronze Age populations of West Siberian forest-steppe (V—I millennium BC), that were identified in a screening study of a large diachronic sample (n = 96). A10 lineages, which are very rare in modern Eurasian populations, were found in all the Bronze Age groups under study. Data on the A10 lineages’ phylogeny and phylogeography in ancient West Siberian and modern Eurasian populations suggest that A10 haplogroup underwent a long-term evolution in West Siberia or arose there autochthonously; thus, the presence of A10 lineages indicates the possible contribution of early autochthonous human groups to the genetic specificity of modern populations, in addition to contributions of later interactions of western and eastern Eurasian populations. PMID:25950581

  8. Carbonate petroleum reservoirs

    SciTech Connect

    Roehl, P.O.; Choquette, P.W.

    1985-01-01

    This book presents papers on the geology of petroleum deposits. Topics considered include diagenesis, porosity, dolomite reservoirs, deposition, reservoir rock, reefs, morphology, fracture-controlled production, Cenozoic reservoirs, Mesozoic reservoirs, and Paleozoic reservoirs.

  9. [Relationships between soil nutrient contents and soil enzyme activities in Pinus massoniana stands with different ages in Three Gorges Reservoir Area].

    PubMed

    Ge, Xiao-Gai; Xiao, Wen-Fa; Zeng, Li-Xiong; Huang, Zhi-Lin; Huang, Ling-Ling; Tan, Ben-Wang

    2012-02-01

    Based on the measurements of soil nutrient contents and enzyme activities and the canonical correspondence analysis (CCA), this paper studied the relationships between soil nutrient contents and soil enzyme activities in different age Pinus massoniana stands in Three Gorges Reservoir Area. Among the test stands, mature stand had the highest contents of organic matter, total nitrogen, ammonium nitrogen, and available phosphorus in 0-20 cm soil layer, followed by middle-aged stand, and nearly-mature stand. With the increase of the stand age, soil invertase activity increased after an initial decrease, cellulase and polyphenoloxidase activities decreased gradually, while urease and peroxidase activities decreased after an initial increase. CCA analysis showed that the effects of the main soil parameters on the soil enzyme activities in the stands ranked in the sequence of total nitrogen > organic matter > pH > bulk density > ammonium nitrogen > available phosphorus. Soil invertase activity had significant positive correlations with soil organic matter, total nitrogen, and total phosphorus, while soil peroxidase activity significantly negatively correlated with soil organic matter, total nitrogen, total phosphorus, and bulk density. The soil was rich in main nutrients, invertase activity was relatively high, while peroxidase activity was relatively low. The activities of soil invertase, cellulase and peroxidase could be used as the good biological indicators in evaluating soil quality and fertility.

  10. Implications of S1 tephra findings in Dead Sea and Tayma palaeolake sediments for marine reservoir age estimation and palaeoclimate synchronisation

    NASA Astrophysics Data System (ADS)

    Neugebauer, Ina; Wulf, Sabine; Schwab, Markus J.; Serb, Johanna; Plessen, Birgit; Appelt, Oona; Brauer, Achim

    2017-08-01

    Here we report on the first findings of a cryptotephra in the Holocene lacustrine sediment records of the Dead Sea and Tayma palaeolake (NW Arabian Peninsula). The major element glass composition of this rhyolitic tephra is identical to the distal 'S1' tephra layer identified in the Yammoûneh palaeolake (Lebanon), in a marine sediment record from the SE Levantine basin and in the Sodmein Cave archaeological site in Egypt. The S1 tephra corresponds to the early Holocene 'Dikkartın' dome eruption of the Erciyes Dağ volcano in central Anatolia (Turkey) and has been dated in the marine record at 8830 ± 140 cal yr BP. We present new age estimates of the S1 tephra based on radiocarbon dating of terrestrial plant remains and pollen concentrates revealing ages of 8939 ± 83 cal yr BP in the Dead Sea sediments and 9041 ± 254 cal yr BP in Tayma. The precise date from the Dead Sea allows refining the early Holocene marine reservoir age in the SE Levantine Sea to ca. 320 ± 50 years. Synchronisation of marine and terrestrial palaeoclimate records in the eastern Mediterranean region using the S1 tephra further suggests a time-transgressive expansion of the early Holocene humid period.

  11. Seismic estimation of porosity in the Permian San Andres carbonate reservoir, Welch Field, Dawson, County, Texas

    SciTech Connect

    Watts, G.P.; Hinterlong, G.D. )

    1996-01-01

    OXY and the DOE Are partners in a advanced technology demonstration project at OXY's West Welch Unit. Production is from a low permeability San Andres reservoir of Permian age similar to many shallow shelf carbonate reservoirs in the Permian Basin. The project involves the construction of a detailed geological model for numerical simulation to design and then conduct a CO[sub 2] flood of the reservoir. Depositional textures of the reservoir rock are highly variable from diagenesis, mostly anhydritic cementing, creating a highly complex pore system. Identification of the interwell reservoir continuity and flow units present the greatest challenge to the reservoir description. A 1993 vintage 3-D seismic survey with a bin spacing of 110[prime] by 165[prime] has been used to assist with the interwell reservoir description. The structure definition at the top and base of the reservoir have been accurately mapped with respect to the well data. Core and well log measurements of porosity, permeability and water saturation were computed and summed across the seismic reservoir interval. Measurements of amplitude, frequency and phase within the 3-D volume were summed across the reservoir interval. All seismic attributes were sampled to the wells and compared through scatterplots to the well log and core measurements. Excellent correlation between three seismic attributes and porosity has been documented. A deterministic method has been used to estimate porosity values at each seismic bin location. The method uses the seismic measurements to shape the geology between the wells while maintaining agreement with the well data at the well locations.

  12. Seismic estimation of porosity in the Permian San Andres carbonate reservoir, Welch Field, Dawson, County, Texas

    SciTech Connect

    Watts, G.P.; Hinterlong, G.D.

    1996-12-31

    OXY and the DOE Are partners in a advanced technology demonstration project at OXY`s West Welch Unit. Production is from a low permeability San Andres reservoir of Permian age similar to many shallow shelf carbonate reservoirs in the Permian Basin. The project involves the construction of a detailed geological model for numerical simulation to design and then conduct a CO{sub 2} flood of the reservoir. Depositional textures of the reservoir rock are highly variable from diagenesis, mostly anhydritic cementing, creating a highly complex pore system. Identification of the interwell reservoir continuity and flow units present the greatest challenge to the reservoir description. A 1993 vintage 3-D seismic survey with a bin spacing of 110{prime} by 165{prime} has been used to assist with the interwell reservoir description. The structure definition at the top and base of the reservoir have been accurately mapped with respect to the well data. Core and well log measurements of porosity, permeability and water saturation were computed and summed across the seismic reservoir interval. Measurements of amplitude, frequency and phase within the 3-D volume were summed across the reservoir interval. All seismic attributes were sampled to the wells and compared through scatterplots to the well log and core measurements. Excellent correlation between three seismic attributes and porosity has been documented. A deterministic method has been used to estimate porosity values at each seismic bin location. The method uses the seismic measurements to shape the geology between the wells while maintaining agreement with the well data at the well locations.

  13. The 3.6 ka Aniakchak tephra in the Arctic Ocean: a constraint on the Holocene radiocarbon reservoir age in the Chukchi Sea

    NASA Astrophysics Data System (ADS)

    Pearce, Christof; Varhelyi, Aron; Wastegård, Stefan; Muschitiello, Francesco; Barrientos, Natalia; O'Regan, Matt; Cronin, Thomas M.; Gemery, Laura; Semiletov, Igor; Backman, Jan; Jakobsson, Martin

    2017-04-01

    The caldera-forming eruption of the Aniakchak volcano in the Aleutian Range on the Alaskan Peninsula at 3.6 cal kyr BP was one of the largest Holocene eruptions worldwide. The resulting ash is found as a visible sediment layer in several Alaskan sites and as a cryptotephra on Newfoundland and Greenland. This large geographic distribution, combined with the fact that the eruption is relatively well constrained in time using radiocarbon dating of lake sediments and annual layer counts in ice cores, makes it an excellent stratigraphic marker for dating and correlating mid-late Holocene sediment and paleoclimate records. This study presents the outcome of a targeted search for the Aniakchak tephra in a marine sediment core from the Arctic Ocean, namely Core SWERUS-L2-2-PC1 (2PC), raised from 57 m water depth in Herald Canyon, western Chukchi Sea. High concentrations of tephra shards, with a geochemical signature matching that of Aniakchak ash, were observed across a more than 1.5 m long sediment sequence. Since the primary input of volcanic ash is through atmospheric transport, and assuming that bioturbation can account for mixing up to ca. 10 cm of the marine sediment deposited at the coring site, the broad signal is interpreted as sustained reworking at the sediment source input. The isochron is therefore placed at the base of the sudden increase in tephra concentrations rather than at the maximum concentration. This interpretation of major reworking is strengthened by analysis of grain size distribution which points to ice rafting as an important secondary transport mechanism of volcanic ash. Combined with radiocarbon dates on mollusks in the same sediment core, the volcanic marker is used to calculate a marine radiocarbon reservoir age offset ΔR = 477 ± 60 years. This relatively high value may be explained by the major influence of typically carbon-old Pacific waters, and it agrees well with recent estimates of ΔR along the northwest Alaskan coast

  14. 87Sr/86Sr as a quantitative geochemical proxy for 14C reservoir age in dynamic, brackish waters: assessing applicability and quantifying uncertainties.

    NASA Astrophysics Data System (ADS)

    Lougheed, Bryan; van der Lubbe, Jeroen; Davies, Gareth

    2016-04-01

    Accurate geochronologies are crucial for reconstructing the sensitivity of brackish and estuarine environments to rapidly changing past external impacts. A common geochronological method used for such studies is radiocarbon (14C) dating, but its application in brackish environments is severely limited by an inability to quantify spatiotemporal variations in 14C reservoir age, or R(t), due to dynamic interplay between river runoff and marine water. Additionally, old carbon effects and species-specific behavioural processes also influence 14C ages. Using the world's largest brackish water body (the estuarine Baltic Sea) as a test-bed, combined with a comprehensive approach that objectively excludes both old carbon and species-specific effects, we demonstrate that it is possible to use 87Sr/86Sr ratios to quantify R(t) in ubiquitous mollusc shell material, leading to almost one order of magnitude increase in Baltic Sea 14C geochronological precision over the current state-of-the-art. We propose that this novel proxy method can be developed for other brackish water bodies worldwide, thereby improving geochronological control in these climate sensitive, near-coastal environments.

  15. 87Sr/86Sr as a quantitative geochemical proxy for 14C reservoir age in dynamic, brackish waters: Assessing applicability and quantifying uncertainties

    NASA Astrophysics Data System (ADS)

    Lougheed, Bryan C.; Lubbe, H. J. L.; Davies, Gareth R.

    2016-01-01

    Accurate geochronologies are crucial for reconstructing the sensitivity of brackish and estuarine environments to dynamic external impacts of the past. Radiocarbon (14C) dating is commonly used for palaeoclimate studies, but its application in brackish environments is severely limited by an inability to quantify spatiotemporal variations in 14C reservoir age, or R(t), due to dynamic interplay between river runoff and marine water. Additionally, old carbon effects and species-specific behavioral processes also influence 14C ages. Using the world's largest brackish water body (the estuarine Baltic Sea) as a test bed, combined with a comprehensive approach that objectively excludes both old carbon (using GIS) and species-specific 14C effects, we demonstrate the use of 87Sr/86Sr ratios for quantifying R(t) in ubiquitous mollusc shell material, leading to almost an order of magnitude increase in Baltic Sea 14C geochronological precision over the current state of the art. We propose that similar proxy methods can be developed for other brackish water bodies worldwide.

  16. Improving 14C dating precision in dynamic, brackish waters by one order of magnitude: 87Sr/86Sr isotopes as a quantitative proxy for 14C reservoir age.

    NASA Astrophysics Data System (ADS)

    Lougheed, B.; Davies, G.; Filipsson, H. L.; van der Lubbe, J.; Snowball, I.

    2016-12-01

    Accurate geochronologies are crucial for reconstructing the sensitivity of brackish and estuarine environments to external impacts. A common geochronological method used for such studies is radiocarbon (14C) dating, but its application in brackish environments is severely limited by an inability to quantify spatiotemporal variations in 14C reservoir age, or R(t), due to dynamic interplay between river runoff and marine water in these environments. Additionally, old carbon effects and species-specific behavioural processes also influence 14C ages. Using the world's largest brackish water body (the estuarine Baltic Sea) as a test-bed, combined with a comprehensive approach that objectively excludes both old carbon and species-specific effects, we demonstrate that it is possible to use 87Sr/86Sr ratios to quantify R(t) in ubiquitous mollusc shell material, leading to an almost one order of magnitude increase in Baltic Sea 14C geochronological precision over the current state-of-the-art. We propose that this novel proxy method can be developed for other brackish water bodies worldwide, thereby improving geochronological control in these climate sensitive, near-coastal environments.

  17. Rates of litter decomposition and soil respiration in relation to soil temperature and water in different-aged Pinus massoniana forests in the Three Gorges Reservoir Area, China.

    PubMed

    Xiao, Wenfa; Ge, Xiaogai; Zeng, Lixiong; Huang, Zhilin; Lei, Jingpin; Zhou, Benzhi; Li, Maihe

    2014-01-01

    To better understand the soil carbon dynamics and cycling in terrestrial ecosystems in response to environmental changes, we studied soil respiration, litter decomposition, and their relations to soil temperature and soil water content for 18-months (Aug. 2010-Jan. 2012) in three different-aged Pinus massoniana forests in the Three Gorges Reservoir Area, China. Across the experimental period, the mean total soil respiration and litter respiration were 1.94 and 0.81, 2.00 and 0.60, 2.19 and 0.71 µmol CO2 m(-2) s(-1), and the litter dry mass remaining was 57.6%, 56.2% and 61.3% in the 20-, 30-, and 46-year-old forests, respectively. We found that the temporal variations of soil respiration and litter decomposition rates can be well explained by soil temperature at 5 cm depth. Both the total soil respiration and litter respiration were significantly positively correlated with the litter decomposition rates. The mean contribution of the litter respiration to the total soil respiration was 31.0%-45.9% for the three different-aged forests. The present study found that the total soil respiration was not significantly affected by forest age when P. masonniana stands exceed a certain age (e.g. >20 years old), but it increased significantly with increased soil temperature. Hence, forest management strategies need to protect the understory vegetation to limit soil warming, in order to reduce the CO2 emission under the currently rapid global warming. The contribution of litter decomposition to the total soil respiration varies across spatial and temporal scales. This indicates the need for separate consideration of soil and litter respiration when assessing the climate impacts on forest carbon cycling.

  18. Rates of Litter Decomposition and Soil Respiration in Relation to Soil Temperature and Water in Different-Aged Pinus massoniana Forests in the Three Gorges Reservoir Area, China

    PubMed Central

    Zeng, Lixiong; Huang, Zhilin; Lei, Jingpin; Zhou, Benzhi; Li, Maihe

    2014-01-01

    To better understand the soil carbon dynamics and cycling in terrestrial ecosystems in response to environmental changes, we studied soil respiration, litter decomposition, and their relations to soil temperature and soil water content for 18-months (Aug. 2010–Jan. 2012) in three different-aged Pinus massoniana forests in the Three Gorges Reservoir Area, China. Across the experimental period, the mean total soil respiration and litter respiration were 1.94 and 0.81, 2.00 and 0.60, 2.19 and 0.71 µmol CO2 m−2 s−1, and the litter dry mass remaining was 57.6%, 56.2% and 61.3% in the 20-, 30-, and 46-year-old forests, respectively. We found that the temporal variations of soil respiration and litter decomposition rates can be well explained by soil temperature at 5 cm depth. Both the total soil respiration and litter respiration were significantly positively correlated with the litter decomposition rates. The mean contribution of the litter respiration to the total soil respiration was 31.0%–45.9% for the three different-aged forests. The present study found that the total soil respiration was not significantly affected by forest age when P. masonniana stands exceed a certain age (e.g. >20 years old), but it increased significantly with increased soil temperature. Hence, forest management strategies need to protect the understory vegetation to limit soil warming, in order to reduce the CO2 emission under the currently rapid global warming. The contribution of litter decomposition to the total soil respiration varies across spatial and temporal scales. This indicates the need for separate consideration of soil and litter respiration when assessing the climate impacts on forest carbon cycling. PMID:25004164

  19. Relationships Between Bird Communities and Forest Age, Structure, Species Composition and Fragmentation in the West Gulf Coastal Plain

    Treesearch

    Richard N. Conner; James G. Dickson

    1997-01-01

    Bird communities of the West Gulf Coastal Plain are strongly influenced by the stage of forest succession, species composition of understory and overstory vegetation, and forest structure. Alteration of plant communities through forest management and natural disturbances typically does not eliminate birds as a fauna1 group from the area affected, but will replace some...

  20. 40Ar-39Ar ages of bentonite beds in the upper part of the Yazoo Formation (Upper Eocene), west-central Mississippi

    USGS Publications Warehouse

    Obradovich, J.D.; Dockery, D. T.; Swisher, C. C.

    1993-01-01

    Bentonite beds recorded from both outcrops and cores in the upper Eocene Yazoo Formation offer opportunities to date the uppermost Eocene of this region and to provide information on the age of the Eocene/Oligocene boundary. This report gives radiometric age dates for three bentonites sampled from the upper Yazoo Formation. Two bentonites are from outcrops near Satartia in western Mississippi and one is from a core hole at Society Ridge in west-central Mississippi. The upper bentonite at Satartia was studied independently at two laboratories using different techniques but with the same results, an age of 34.3 Ma (million years). Results from the Society Ridge bentonite gave the same age. -from Authors

  1. Geoscience/engineering characterization of the interwell environment in carbonate reservoirs based on outcrop analogs, Permian Basin, West Texas and New Mexico. Quarterly technical progress report, April 1, 1995--June 1, 1995

    SciTech Connect

    Lucia, F.J.; Kerans, C.

    1995-09-01

    The objective of this project is to investigate styles of reservoir heterogeneity that occur in low permeability pelleted wackestone/packstone facies and mixed carbonate/clastic facies found in Permian Basin reservoirs by studying similar facies exposed in the Guadalupe mountains. Specific objectives for the outcrop study include construction of a stratigraphic framework, petrophysical quantification of the framework, and testing the outcrop reservoir model for effects of reservoir heterogeneity on production performance. Specific objectives for the subsurface study parallel objectives for the outcrop study. Technical progress is reported for outcrop activities and subsurface activities.

  2. Geoscience/engineering characterization of the interwell environment in carbonate reservoirs based on outcrop analogs, Permian Basin, West Texas and New Mexico. Quarterly report, January 1--April 30, 1996

    SciTech Connect

    Lucia, F.J.; Kerans, C.

    1996-04-30

    The objective of this project is to investigate styles of reservoir heterogeneity found in low-permeability pelleted wackestone/packstone facies and mixed carbonate/clastic facies found in Permian Basin reservoirs by studying similar facies exposed in the Guadalupe Mountains. Specific objectives for the outcrop study include construction of a stratigraphic framework, petrophysical quantification of the framework, and testing the outcrop reservoir model for effects of reservoir heterogeneity on production performance. Specific objectives for the subsurface study parallel objectives for the outcrop study.

  3. TRITIUM RESERVOIR STRUCTURAL PERFORMANCE PREDICTION

    SciTech Connect

    Lam, P.S.; Morgan, M.J

    2005-11-10

    The burst test is used to assess the material performance of tritium reservoirs in the surveillance program in which reservoirs have been in service for extended periods of time. A materials system model and finite element procedure were developed under a Savannah River Site Plant-Directed Research and Development (PDRD) program to predict the structural response under a full range of loading and aged material conditions of the reservoir. The results show that the predicted burst pressure and volume ductility are in good agreement with the actual burst test results for the unexposed units. The material tensile properties used in the calculations were obtained from a curved tensile specimen harvested from a companion reservoir by Electric Discharge Machining (EDM). In the absence of exposed and aged material tensile data, literature data were used for demonstrating the methodology in terms of the helium-3 concentration in the metal and the depth of penetration in the reservoir sidewall. It can be shown that the volume ductility decreases significantly with the presence of tritium and its decay product, helium-3, in the metal, as was observed in the laboratory-controlled burst tests. The model and analytical procedure provides a predictive tool for reservoir structural integrity under aging conditions. It is recommended that benchmark tests and analysis for aged materials be performed. The methodology can be augmented to predict performance for reservoir with flaws.

  4. Evidence that the Migration of the Northern Subpopulation of Pacific Sardine (Sardinops sagax) off the West Coast of the United States Is Age-Based

    PubMed Central

    2016-01-01

    Analysis of fish movements has been an important area of study for fisheries ecology and population dynamics for decades. Pacific sardine, Sardinops sagax, along the west coast of the United States exhibit a well-defined large-scale seasonal migration. Larger and older fish are found in the northern reaches of their range during summer and contract to southerly offshore areas for spawning during spring. Because of the close correlation between fish size and age it has not yet been determined if movements are size- or age-based. Measuring spatial changes in the age structure conditioned on individual lengths was used to determine the roles of age versus length in the seasonal migration. S. sagax have a pattern of increasing age-at-length with seasonal northward movements and offshore movements for spawning. The pattern of increasing age-at-length with distance from the origin eliminates a solely length-based process of movement and supports age-based movement. Patterns in the size and age when fish first show migratory behaviors, coupled with the patterns observed during the spawning season, support a hypothesis that migratory behaviors are linked to age-based ontogenetic changes associated with maturation. PMID:27851805

  5. Millennial-scale variability in the local radiocarbon reservoir age of the Florida Keys reef tract during the Holocene

    NASA Astrophysics Data System (ADS)

    Ashe, E.; Toth, L. T.; Cheng, H.; Edwards, R. L.; Richey, J. N.

    2016-12-01

    The oceanic passage between the Florida Keys and Cuba, known as the Straits of Florida, provides a critical connection between the tropics and northern Atlantic. Changes in the character of water masses transported through this region may ultimately have important impacts on high-latitude climate variability. Although recent studies have documented significant changes in the density of regional surface waters over millennial timescales, little is known about the contribution of local- to regional-scale changes in circulation to surface-water variability. Local variability in the radiocarbon age, ΔR, of surface waters can be used to trace changes in local water-column mixing and/or changes in regional source water over a variety of spatial and temporal scales. We reconstructed "snapshots" of ΔR variability across the Florida Keys reef tract during the last 10,000 years by dating 68 unaltered corals collected from Holocene reef cores with both U-series and radiocarbon techniques. We combined the snapshots of ΔR into a semi-empirical model to develop a robust statistical reconstruction of millennial-scale variability in ΔR on the Florida Keys reef tract. Our model demonstrates that ΔR varied significantly during the Holocene, with relatively high values during the early Holocene and around 3000 years BP and relatively low values around 7000 years BP and at present. We compare the trends in ΔR to existing paleoceanographic reconstructions to evaluate the relative contribution of local upwelling versus changes in source water to the region as a whole in driving local radiocarbon variability, and discuss the importance of these results to our understanding of regional-scale oceanographic and climatic variability during the Holocene. We also discuss the implications of our results for radiocarbon dating of marine samples from south Florida and present a model of ΔR versus 14C age that can be used to improve the accuracy of radiocarbon calibrations from this region.

  6. West Hackberry Tertiary Project

    SciTech Connect

    Gillham, Travis; Yannimaras, Demetrios

    1999-11-03

    The West Hackberry Tertiary Project is a field test of the concept that air injection can generate tertiary oil recovery through the Double Displacement Process. The Double Displacement Process is the gas displacement of a water invaded oil column for the purpose of recovering tertiary oil through gravity drainage. The novel aspect of this project is the use of air as the injection fluid. In Gulf Coast oil reservoirs with pronounced bed dip, reservoir performance has shown that gravity drainage recoveries average 80% to 90% of the original oil in place while water drive recoveries average 50% to 60% of the original oil in place. The target for tertiary oil recovery with the Double Displacement Process is the incremental oil between the 50% to 60% water drive recoveries and the 80% to 90% gravity drainage recoveries. The use of air injection in this process combines the benefits of air's low cost and universal accessibility with the potential for improved oil recovery resulting from spontaneous in situ combustion. If successful, this project will demonstrate that utilizing air injection in the Double Displacement Process will result in an economically viable tertiary process in many Gulf Coast oil reservoirs where other tertiary processes are presently uneconomic. The West Hackberry Tertiary Project receives matching funds from the United States Department of Energy (DOE) as part of the DOE's Class 1 Program for the development of advance recovery technologies in fluvial dominated deltaic reservoirs. In addition, the Petroleum Engineering Department at Louisiana State University (LSU) provides independent study and technology transfer.

  7. Use of 210Pb and 137Cs to simultaneously constrain ages and sources of post-dam sediments in the Cordeaux reservoir, Sydney, Australia.

    PubMed

    Simms, Ava D; Woodroffe, Colin; Jones, Brian G; Heijnis, Henk; Mann, Rob A; Harrison, Jennifer

    2008-07-01

    Environmental radionuclides can be employed as tracers of sediment movement and delivery to water bodies such as lakes and reservoirs. The chronologies of sediments that have accumulated in the Cordeaux reservoir in Sydney, Australia, were determined by the rate of change of (210)Pb(ex) with depth and indicate slow accretion in the reservoir. The ratio of enrichment of radionuclides in sediment cores to (210)Pb(ex) and (137)Cs concentrations in a reference soil sample within the Cordeaux catchment indicates that the dominant source of sediment in the Cordeaux reservoir is surface erosion (detachment and removal of sediment at depths less than 30 cm). However, in the Kembla Creek arm of the reservoir a mixture of sources was detected and includes sheet and rill erosion together with sub-soil contributions. Implications for the utility of these radionuclide sedimentation assessments, especially where samples are limited, are that well-constrained chronologies and sources of soil erosion are facilitated.

  8. Open-System Magma Reservoir Affects Gas Segregation, Vesiculation, Fragmentation and Lava/Pyroclast Dispersal During the 1.2 km-deep 2007-2010 Submarine Eruption at West Mata Volcano

    NASA Astrophysics Data System (ADS)

    Rubin, K. H.; Clague, D. A.; Embley, R. W.; Hellebrand, E.; Soule, S. A.; Resing, J.

    2014-12-01

    West Mata, a small, active rear-arc volcano in the NE Lau Basin, erupts crystal and gas rich boninite magma. Eruptions were observed at the summit (1.2 km water depth) during 5 ROV Jason dives in 2009 (the deepest erupting submarine volcano observed to date). Subsequent ROV and ship-based bathymetric mapping revealed that a pit crater formed and the summit eruption ceased in 2010, with roughly simultaneous eruptions along the SW rift zone. During the summit eruption, a combination of water depth, H2O-CO2-rich and high crystallinity magma, a split in the conduit to feed two vent sites, and waxing/waning magma supply led to a range of effusive/explosive eruption styles and volcanic deposit types. The 2-3 vent Hades cluster and the lone Prometheus vent had different eruption characteristics. Petrographic, petrologic and geochemical studies of erupted products indicate a change in magma composition in time and space over a period of 3.5 yrs, suggesting a small, open-system magma reservoir within the volcano. Prometheus (1174m depth) produced mostly pyroclastic material during our observations (e.g., highly vesicular glowing fluidal ejecta that cooled in the water column and rounded recycled dense clasts), but sampling and 210Po radiometric dating show that several months prior pillowed lava flows, subsequently covered with cm-sized pyroclasts, had flowed >50m from the vent. In contrast, vents at Hades (1200m depth) cycled between lava production and vigorous degassing, 10-20m high fire fountains and bursts of glowing lava-skinned bubbles, the products of which froze/broke in the water column, forming unstable cones of spatter and scoria near the vents. We hypothesize that bubbles collapse rather than form lava balloons because of skin brittleness (from high crystal content) and hydrostatic pressure. Clast settling times and patterns suggest >100m water column rise height for 10+ cm-sized fragments. Pillow flows were also observed to be issuing from the base of the

  9. [Education, birth cohort, and marriage age: a comparative analysis of marriage age in West Germany, East Germany, and the United States].

    PubMed

    Bruderl, J; Diekmann, A

    1994-02-01

    "This paper investigates how education influences marriage behavior in three countries: the United States, West Germany, and former East Germany. Following family economics we postulate that for women a longer education decreases marriage rates both during education (institutional effect) and after the degree has been obtained (human capital effect). For men family economics predicts the delaying institutional effect, too, but the human capital effect is expected to increase marriage rates. Further considerations lead to the additional hypothesis that for younger birth cohorts these sex differences should attenuate.... For the United States and West Germany the observed marriage patterns confirm our hypotheses for the most part. For East Germany, however, we observe different marriage patterns. This was expected because the institutional context in this former socialist country was a very different one." (SUMMARY IN ENG)

  10. Building the 3-D jugsaw puzzle: Applications of sequence stratigraphy to 3-D reservoir characterization, Permian basin

    SciTech Connect

    Tinker, S.W.

    1996-04-01

    Reservoir characterization involves the quantification, integration, reduction, and analysis of geological, petrophysical, seismic, and engineering data. This is no small task. A principal goal of reservoir characterization is to derive a spatial understanding of interwell heterogeneity. Traditionally, geologic attempts to characterize interwell heterogeneity have been done using hand-drawn or computer-generated two-dimensional (2-D) maps and cross sections. Results can be improved dramatically using three-dimensional (3-D) interpretation and analysis techniques. Three-dimensional reservoir characterization requires the same input data used in 2-D approaches, and the cost is equal to, and commonly lower than, traditional 2-D methods. The product of 3-D reservoir characterization is a 3-D reservoir model. The language used to communicate the results of a 3-D reservoir model is visualization; i.e., visual images of numerical data. All of the available log and core data in a model area are incorporated in a 3-D model, but the data are depicted as colored cells rather than as log traces. The integrity of the 3-D reservoir model is largely a function of the stratigraphic framework. Interpreting the correct stratigraphic framework for a subsurface reservoir is the most difficult and creative part of the 3-D modeling process. Sequence and seismic stratigraphic interpretation provide the best stratigraphic framework for 3-D reservoir modeling. The purpose of this paper is to discuss the pro- cess of 3-D deterministic reservoir modeling and to illustrate the advantages of using a sequence stratigraphic framework in 3-D modeling. Mixed carbonate and siliciclastic sediment outcrop and subsurface examples from the Permian basin of west Texas and New Mexico will be used as examples, but the concepts and techniques can be applied to reservoirs of any age.

  11. Strange old worlds: socio-critical reports about old-age experiences in West German print media (1970s-1990s).

    PubMed

    Streubel, Christiane

    2011-01-01

    This article examines West German images of old age and the elderly in a period when this increasingly became a topical issue. Between the 1970s and the 1990s, the elderly were the subject of socio-critical reports in leading political magazines like Der Spiegel, Die Zeit and Stern. In these specific journalistic formats, the media entered unfamiliar places like old people's homes, the elderly's private apartments or tea dances for senior citizens. By analysing the language used in such media reports, this article shows continuity and change in attitudes towards the elderly, explores the impact of the new old-age model 'the young at heart', and the relevance of gender and generational ascriptions. In doing so, this article uncovers the recent historical context of current social debates about old age.

  12. /sup 40/Ar//sup 39/Ar age of detrital muscovite within Lower Ordovician sandstone in the coastal plain basement of Florida: implications for west African terrane linkages

    SciTech Connect

    Dallmeyer, R.D.

    1987-11-01

    Detrital muscovite was concentrated from a core of Lower Ordovician sandstone recovered from 1282 m in the Sun Oil Company, H.T. Parker No.1 well, Marion County, Florida. The concentrate records a /sup 40/Ar//sup 39/Ar plateau age of 504.1 +/- 2.1 Ma. The Paleozoic sedimentary section penetrated in this well is part of an extensive subsurface Lower Ordovician-Middle Devonian sedimentary succession characterized by Gondwanan paleontological affinities. The succession has been correlated with sequences of similar age in the Bove Basin of west Africa which unconformably overlie metamorphic units of the Bassaride and Rokelide orogens in Senegal and Guinea. Muscovite within these metamorphic rocks records ca. 500-510 Ma postmetamorphic /sup 40/Ar//sup 39/Ar cooling ages and was likely a proximal source for the lower Paleozoic clastic detritus represented in the pre-Mesozoic sedimentary sequences beneath the southeastern US coastal plain.

  13. Sedimentation and sustainability of western American reservoirs

    NASA Astrophysics Data System (ADS)

    Graf, William L.; Wohl, Ellen; Sinha, Tushar; Sabo, John L.

    2010-12-01

    Reservoirs are sustainable only as long as they offer sufficient water storage space to achieve their design objectives. Life expectancy related to sedimentation is a measure of reservoir sustainability. We used data from the Army Corps of Engineers, U.S. Bureau of Reclamation, and U.S. Geological Survey (Reservoir Sedimentation Survey Information System II (RESIS II)) to explore the sustainability of American reservoirs. Sustainability varied by region, with the longest life expectancies in New England and the Tennessee Valley and the shortest in the interior west. In the Missouri and Colorado River basins, sedimentation and rates of loss of reservoir storage capacity were highly variable in time and space. In the Missouri River Basin, the larger reservoirs had the longest life expectancies, with some exceeding 1000 years, while smaller reservoirs in the basin had the shortest life expectancies. In the Colorado River Basin at the site of Glen Canyon Dam, sediment inflow varied with time, declining by half beginning in 1942 because of hydroclimate and upstream geomorphic changes. Because of these changes, the estimated life expectancy of Lake Powell increased from 300 to 700 years. Future surprise changes in sedimentation delivery and reservoir filling area are expected. Even though large western reservoirs were built within a limited period, their demise will not be synchronous because of varying sedimentation rates. Popular literature has incorrectly emphasized the possibility of rapid, synchronous loss of reservoir storage capacity and underestimated the sustainability of the water control infrastructure.

  14. The Longitudinal Course of Insomnia Symptoms: Inequalities by Sex and Occupational Class Among Two Different Age Cohorts Followed for 20 Years in the West of Scotland

    PubMed Central

    Green, Michael J.; Espie, Colin A.; Hunt, Kate; Benzeval, Michaela

    2012-01-01

    Study Objectives: The natural history of insomnia symptomatology is poorly understood. Cross-sectional associations have been demonstrated among socioeconomic disadvantage, female sex, and poor sleep but it is unclear how these social factors predict patterns of insomnia symptoms over time. The aim of this article is to describe longitudinal patterns of insomnia symptoms as people age and investigate how they vary by sex and occupational class. Design: A prospective cohort study with 20 yr of follow-up from 1987 to 1988. Setting: West of Scotland. Participants: One cohort approximately 36 yr of age at baseline aging to 57 yr (n = 1,444), and another aging from approximately 56 to 76 yr (n = 1,551). Interventions: N/A. Measurements and Results: At approximately 5-yr intervals, respondents self-reported trouble initiating and maintaining sleep. Latent class analysis identified 4 main sleep patterns: a healthy pattern with little sleeping trouble across the 20 yr; an episodic pattern, characterized by trouble maintaining sleep; a chronic pattern with trouble maintaining and initiating sleep throughout the study; and a pattern where symptoms developed during the 20-yr follow-up. Chronic patterns were more likely in the older cohort than the younger one, for women than men in the older cohort, and for those from a manual rather than a nonmanual occupational class in both cohorts. In the middle-aged cohort a developing pattern was more likely for women than men. Conclusions: Chronic symptoms, characterized by both trouble maintaining and initiating sleep, are patterned by social factors. Citation: Green MJ; Espie CA; Hunt K; Benzeval M. The longitudinal course of insomnia symptoms: inequalities by sex and occupational class among two different age cohorts followed for 20 years in the west of Scotland. SLEEP 2012;35(6):815-823. PMID:22654201

  15. Question of Ages of Cenozoic Volcanic Centers Inferred Beneath the West Antarctic Ice Sheet (WAIS) in the West Antarctic Rift System (WR) from Coincident Aeromagnetic and Radar Ice Sounding Surveys

    NASA Astrophysics Data System (ADS)

    Behrendt, J. C.; Finn, C. A.; Blankenship, D. D.

    2007-12-01

    The recently acquired radar ice sounding surveys (Holt, et al., 2006) extending the 1990s Central West Antarctica (CWA) aerogeophysical survey to the Amundsen and Bellingshausen sea coasts allows us to revise a thought experiment reported by Behrendt et al., 1991 from very limited bed elevation data. Were the ice of the WAIS flowing through the WR to be compressed to the density of crustal rock, almost all of the area beneath the WAIS would be at or above sea level, much >1 km elevation. There are only about 10-20% of the very deep areas (such as the Bentley subglacial trench and the Byrd Subglacial Basin) filled with 3-4-km thick ice that would be well below sea level. The age of the 5-7-km high rift shoulder bounding the asymmetric WR from northern Victoria Land through the Horlick Mountains (where it diverges from the Transantarctic Mountains) to the Ellsworth Mountains has been reported as old as Cretaceous. Volcanic exposures associated with the West Antarctic rift system in the present WAIS area extend at least to 34 Ma and the West Antarctic ice sheet has flowed through the rift possibly as far back in time as 25 Ma. Active volcanism has been reported for the WR at only a few widely scattered locations, so speculations about present volcanic activity beneath the WAIS are quite uncertain, and it is probably quite rare. The Central West Antarctic aeromagnetic and radar ice sounding survey carried out in the 1990s revealed about 1000 "volcanic centers" characterized by 100-1000 nT shallow source magnetic anomalies, at least 400 of which have associated bed topography. About 80% of these show relief <200 m and have been interpreted as smoothed off as they were erupted (injected) into the moving WAIS. Several kilometer-thick highly magnetic sources are required to fit these anomalies requiring high remanent magnetizations in the present field direction. We interpreted these sources as subvolcanic intrusions which must be younger than about 100 Ma because the

  16. FILTERED WATER RESERVOIR, LOOKING NORTHWEST. A CORNER OF THE NEW ...

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

    FILTERED WATER RESERVOIR, LOOKING NORTHWEST. A CORNER OF THE NEW PUMPING STATION IS VISIBLE AT RIGHT. - Division Avenue Pumping Station & Filtration Plant, West 45th Street and Division Avenue, Cleveland, Cuyahoga County, OH

  17. 39. JL photographer, summer 1978, view of covered reservoir at ...

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

    39. JL photographer, summer 1978, view of covered reservoir at Baldwin filtration plant. - Division Avenue Pumping Station & Filtration Plant, West 45th Street and Division Avenue, Cleveland, Cuyahoga County, OH

  18. Stunting, underweight and wasting among Integrated Child Development Services (ICDS) scheme children aged 3-5 years of Chapra, Nadia District, West Bengal, India.

    PubMed

    Bose, Kaushik; Biswas, Sadaruddin; Bisai, Samiran; Ganguli, Sanjib; Khatun, Argina; Mukhopadhyay, Ashish; Bhadra, Mithu

    2007-07-01

    This study investigated age and sex variations in height and weight, levels of stunting, underweight and wasting among 533 (254 boys; 279 girls) 3- to 5-year-old rural children of Bengalee ethnicity at 11 Integrated Child Development Services centres of Nadia District, West Bengal, India. Height-for-age, weight-for-age and weight-for-height < -2 z-scores were used to evaluate stunting, underweight and wasting, respectively, following the National Center for Health Statistics (NCHS) Guidelines. Results revealed that boys were significantly heavier than girls at age 3 years. Significant age differences existed in mean height and weight in both sexes. Mean z-scores of height-for-age, weight-for-age and weight-for-height were lower than those of NCHS for both sexes at all ages. The overall (age and sex combined) rates of stunting, underweight and wasting were 23.9%, 31.0% and 9.4%, respectively. The rate of underweight and wasting was higher among girls (underweight = 35.1%, wasting = 12.2%) compared with boys (underweight = 26.5%, wasting = 6.3%). In general, the frequency of stunting increased with increasing age in both sexes. Based on the World Health Organization classification of severity of malnutrition, the overall prevalence of underweight was very high (>or=30%). The prevalence rates of stunting (20-29%) and wasting (5-9%) were medium. In conclusion, the nutritional status of the subjects is unsatisfactory. There is scope for improvement in the form of enhanced supplementary nutrition.

  19. Changing profile of joint disorders with age: findings from a postal survey of the population of Calderdale, West Yorkshire, United Kingdom.

    PubMed Central

    Badley, E M; Tennant, A

    1992-01-01

    A survey of the age-sex specific prevalence of joint problems in a population and associated features such as disablement and use of treatment was carried out in 1986 in Calderdale, West Yorkshire, United Kingdom. A postal questionnaire was sent to 25,168 households; 87% were returned, representing households containing 42,826 people aged 16 years and over. Positive answers to a question about pain, swelling, or stiffness in the joints, neck, or back were given by 10,246 subjects, 24% of the population aged 16 years and older, of whom 6181 (60.3%) were women. The rate of reporting of joint problems increased markedly with age, from 5% for subjects aged 16-24 years to 54% for those aged 85 years and older. The joint sites most often reported as affected were the knee and the back, with a frequency in the population of about 10%. The increase in joint problems with age was accompanied by an increase in reported morning stiffness of more than half an hour, taking drugs, and disability, but not in reporting seeing a specialist for these conditions. Of those aged 85 years and older who reported joint problems, most also had difficulty or dependence in activities of daily living. The increasing prevalence of joint problems with age has implications for the provision of care, both in the community and in hospitals, especially in view of the aging of the population as a whole. The planning of health services for those with rheumatic disorders needs to take into account the high incidence of joint problems in the population. PMID:1533506

  20. The incidence, age at diagnosis of breast cancer in the Iraqi Kurdish population and comparison to some other countries of Middle-East and West.

    PubMed

    Molah Karim, Sherko Abdullah; Ali Ghalib, Hawar Hasan; Mohammed, Sangar Abdullah; Fattah, Fattah Hama Rahim

    2015-01-01

    Studies on breast cancer among Iraqi Kurdish are limited. The incidence of breast cancer is lower, more common in younger age and a significant proportion of cases occur in premenopausal women. The aims of this study are to estimate the age-standardized incidence rate, age-specific rates and their comparison with some countries of Middle-East and West, and clarify the association of family history and premenopausal status with breast cancer. This retrospective case control study was conducted in Sulaimanyah governorate (North of Iraq). Data were collected regarding demographical profile of 536 patients who were registered in Hewa Hematology and Oncology Hospital during 2011-2013, and 496 age-matched controls. There were 536 cases of breast cancer, 526 of them were female. The age range was 20-82 years. The mean age at diagnosis was 49.42±11.66 years compared to control 46.7±10.2 (p˂0.001, 95% CI: 1.7-3.7). The age-standardized rate was 17.9/100,000 Kurdish women population/year. Five year age-specific rates show the peak incidence for the age group 45-49 years (79.3/100,000). A significant percentage of patients were premenopausal at the time of diagnosis, which is account 55.52% of cases compared to control 59.67% (p=0.53). About 13.49% of cases have family history of breast cancer compared to control 3.2% (p=0.02). Among Kurdish people in Iraq, the incidence of breast cancer is less than Middle-East and Western countries with higher incidence in younger age group than western society, but similar to Middle-East countries. More than half of Kurdish women with breast cancer are premenopausal. Copyright © 2014 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

  1. U.K. reservoir spurs environmental studies

    NASA Astrophysics Data System (ADS)

    Cole, John A.

    The South West Water Authority is building a new river regulating reservoir to meet growing demands for water supplies in the Plymouth and Bideford areas of Devon, England. The new reservoir impounds the river Wolf within the Tamar catchment (see figure). The Tamar and its tributaries are prime fishing rivers rich in sea trout and Atlantic salmon. Construction of the Roadford dam began early in 1987, and by 1990 a reservoir capable of storing 37×106 m3 will be created. Releases from the reservoir will regulate the low flows of the river Tamar, from which water will be pumped near its tidal limit at Gunnislake, to water treatment plants supplying Plymouth. Additionally, reservoir water will be pumped over the divide to the river Torridge, thus permitting increased abstraction from the latter catchment.

  2. Proterozoic to Mesozoic evolution of North-West Africa and Peri-Gondwana microplates: Detrital zircon ages from Morocco and Canada

    NASA Astrophysics Data System (ADS)

    Marzoli, Andrea; Davies, Joshua H. F. L.; Youbi, Nasrrddine; Merle, Renaud; Dal Corso, Jacopo; Dunkley, Daniel J.; Fioretti, Anna Maria; Bellieni, Giuliano; Medina, Fida; Wotzlaw, Jörn-Frederik; McHone, Greg; Font, Eric; Bensalah, Mohamed Khalil

    2017-05-01

    The complex history of assemblage and disruption of continental plates surrounding the Atlantic Ocean is in part recorded by the distribution of detrital zircon ages entrained in continental sedimentary strata from Morocco (Central High Atlas and Argana basins) and Canada (Grand Manan Island, New Brunswick). Here we investigate detrital zircon from the latest Triassic (ca. 202 Ma) sedimentary strata directly underlying lava flows of the Central Atlantic magmatic province or interlayered within them. SHRIMP (Sensitive High-Resolution Ion MicroProbe) and LA-ICP-MS (Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry) U-Pb ages for zircon range from Paleozoic to Archean with a dominant Neoproterozoic peak, and significant amounts of ca. 2 Ga zircon. These ages suggest a prevailing West African (Gondwanan) provenance at all sampling sites. Notably, the Paleoproterozoic zircon population is particularly abundant in central Morocco, north of the High Atlas chain, suggesting the presence of Eburnean-aged rocks in this part of the country, which is consistent with recent geochronologic data from outcropping rocks. Minor amounts of late Mesoproterozoic and early Neoproterozoic zircon ages (ca. 1.1-0.9 Ga) in Moroccan samples are more difficult to interpret. A provenance from Avalonia or Amazonia, as proposed by previous studies is not supported by the age distributions observed here. An involvement of more distal source regions, possibly located in north-eastern Africa (Arabian Nubian Shield) would instead be possible. Paleozoic zircon ages are abundant in the Canadian sample, pointing to a significant contribution from Hercynian aged source rocks. Such a signal is nearly absent in the Moroccan samples, suggesting that zircon-bearing Hercynian granitic rocks of the Moroccan Meseta block were not yet outcropping at ca. 200 Ma. The only Moroccan samples that yield Paleozoic zircon ages are those interlayered within the CAMP lavas, suggesting an increased dismantling

  3. Comparison of the Rowe–Kahn Model of Successful Aging With Self-rated Health and Life Satisfaction: The West of Scotland Twenty-07 Prospective Cohort Study

    PubMed Central

    Whitley, Elise; Popham, Frank; Benzeval, Michaela

    2016-01-01

    Purpose of the Study: With increasing longevity in industrialized populations, there is growing interest in what defines “successful aging” (SA). Various SA measures have been proposed but no consensus has been reached and many have been criticized for not representing the views and priorities of older people. We consider whether the Rowe–Kahn SA model captures older individual’s perceptions of their own health and aging. Methods: Using two cohorts of 886 and 483 men and women from the West of Scotland Twenty-07 Study, aged around 57 and 76, respectively, we explored associations between Rowe–Kahn SA dimensions (absence of disease/disability; good physical/cognitive functioning; good interpersonal/productive social engagement) and four aspects of self-rated health and satisfaction (current general health; health for age; satisfaction with health; satisfaction with life). Results: Respondents’ self-rated health and satisfaction was generally good but few had all six Rowe–Kahn dimensions positive, the conventional definition of SA. All individual positive SA dimensions were associated with better self-rated health and satisfaction. This was consistent across age, gender, manual/nonmanual occupations, and personality. The prevalence of good self-rated health and satisfaction increased with increasing numbers of positive SA dimensions. Implications: The Rowe–Kahn model provides a functional definition of SA. Future work on ageing should include all Rowe–Kahn dimensions and consider SA as a continuum. PMID:26970606

  4. The relationship of age, body mass index and waist circumference with blood pressure in Bengalee Hindu male jute mill workers of Belur, West Bengal, India.

    PubMed

    Bose, Kaushik; Ghosh, Arnab; Roy, Sabyasachi; Gangopadhyay, Somnath

    2005-06-01

    A cross-sectional study of 150 adult Bengalee Hindu male jute mill workers of Belur, a suburb of Kolkata, West Bengal, India, was undertaken to study the relationship of age, body mass index (BMI) and waist circumference (WC) with systolic (SBP), diastolic (DBP) and mean arterial (MAP) blood pressure. The mean age and the BMI of the subjects were 40.7 years (S.D. = 15.2) and 23.2 kg/m2 (S.D. = 3.2), respectively. The mean SBP, DBP and MAP were 124.7 mmHg (S.D. = 7.8), 81.5 mmHg (S.D. = 5.7) and 95.9 mmHg (S.D. = 6.1), respectively. Age had similar significant (p < 0.001) correlations with BMI and WC. Age and WC were significantly correlated (p < 0.001) with all the three blood pressure variables. In general, the correlations of BMI with SBP (r = 0.24, p < 0.01), DBP (r = 0.15, n.s.) and MAP (r = 0.19, p < 0.05) were weaker. Age controlled multiple regression analyses demonstrated that BMI did not have a significant effect of any blood pressure variable. However, WC had a significant impact (p < 0.0001) on SBP (t = 7.068), DBP (t = 5.190) and MAP (t = 6.387), even after adjusting for the effect of age. Moreover, even after age adjustment, percent variations in SBP (20.7%), DBP (12.5%) and MAP (17.2%) explained by WC were high. This significant impact (p < 0.0001) of WC on SBP (t = 9.426), DBP (t = 8.349) and MAP (t = 9.642) remained even after controlling for the combined effects of age and BMI.

  5. Geoscience/engineering characterization of the interwell environment in carbonate reservoirs based on outcrop analogs, Permian Basin, West Texas and New Mexico-stratigraphic hierarchy and cycle stacking facies distribution, and interwell-scale heterogeneity: Grayburg Formation, New Mexico. Final report

    SciTech Connect

    Barnaby, R.J.; Ward, W.B.; Jennings, J.W. Jr.

    1997-06-01

    The Grayburg Formation (middle Guadalupian) is a major producing interval in the Permian Basin and has yielded more than 2.5 billion barrels of oil in West Texas. Grayburg reservoirs have produced, on average, less than 30 percent of their original oil in place and are undergoing secondary and tertiary recovery. Efficient design of such enhanced recovery programs dictates improved geological models to better understand and predict reservoir heterogeneity imposed by depositional and diagenetic controls. The Grayburg records mixed carbonate-siliciclastic sedimentation on shallow-water platforms that rimmed the Delaware and Midland Basins. Grayburg outcrops in the Guadalupe and Brokeoff Mountains region on the northwest margin of the Delaware Basin present an opportunity to construct a detailed, three-dimensional image of the stratigraphic and facies architecture. This model can be applied towards improved description and characterization of heterogeneity in analogous Grayburg reservoirs. Four orders of stratigraphic hierarchy are recognized in the Grayburg Formation. The Grayburg represents a long-term composite sequence composed of four high-frequency sequences (HFS 1-4). Each HFS contains several composite cycles comprising two or more cycles that define intermediate-scale transgressive-regressive successions. Cycles are the smallest scale upward-shoaling vertical facies successions that can be recognized and correlated across various facies tracts. Cycles thus form the basis for establishing the detailed chronostratigraphic correlations needed to delineate facies heterogeneity.

  6. Preliminary Vertical Slip Rate for the West Tahoe Fault from six new Cosmogenic 10Be Exposure Ages of Late Pleistocene Glacial Moraines at Cascade Lake, Lake Tahoe, California

    NASA Astrophysics Data System (ADS)

    Pierce, I. K. D.; Wesnousky, S. G.; Kent, G. M.; Owen, L. A.

    2015-12-01

    The West Tahoe Fault is the primary range bounding fault of the Sierra Nevada at the latitude of Lake Tahoe. It is a N-NW striking, east dipping normal fault that has a pronounced onshore quaternary scarp extending from highway 50 southwest of Meyers, CA to Emerald Bay. At Cascade Lake, the fault cuts and progressively offsets late Pleistocene right lateral moraines. The fault vertically offsets the previously mapped Tahoe moraine ~83 m and the Tioga moraine ~23 m, measured from lidar data. Seventeen samples were collected for 10Be cosmogenic age analysis from boulders on both the hanging and footwalls of the fault along the crests of these moraines.We report here the initial analysis of 6 of these boulders and currently await processing of the remainder. The 10Be exposure ages of 3 boulders each on the younger Tioga and older Tahoe moraines range from 12.7 +/- 1.6 to 20.7 +/- 3.3 ka and 13.3 +/- 2.1 to 72.5 +/- 8.8 ka, respectively. Using the oldest ages as minima, these preliminary results suggest that the slip rate has averaged ~1 mm/yr since the penultimate glaciation, in accord with estimates of previous workers, and place additional bounds on the age of glaciation in the Lake Tahoe basin. The Last Glacial Maxima and penultimate glaciation near Lake Tahoe thus appear to coincide with the Tioga and Tahoe II glaciations of the Eastern Sierra.

  7. Geochemical characteristics and U-Pb zircon LA-ICPMS ages of granitoids from the Pan-African Dahomeyide orogen, West Africa

    NASA Astrophysics Data System (ADS)

    Attoh, Kodjopa; Samson, Scott; Agbossoumondé, Yao; Nude, Prosper M.; Morgan, Jennifer

    2013-03-01

    The Dahomeyide orogen in southeastern Ghana and adjoining parts of Togo and Benin records the suture of West African craton (WAC) into northwest Gondwana. The suture zone is characterized by distinctive high-pressure mafic rocks that mark the collision of WAC with exotic blocks to the east. Granitoids to the east of the suture zone, which are postulated to be juvenile crust representing the arc terrane that formed during subduction and oceanic closure, were investigated. We compiled a map of granitoid gneisses in Ghana, Togo, and Benin which allows us to distinguish between two main rock types: (1) migmatitic gneisses with biotite as the dominant mafic mineral and (2) dioritic gneiss characterized by hornblende as the main mafic mineral and with occasional garnet. These rocks types are separated by a shear zone inferred to be a splay of Kandi shear zone, a segment of the Trans-Saharan shear zone that extends for ∼2500 km from the Sahara to the Gulf of Guinea. The granitoids are characterized by I-type signatures, display variable amounts of LREE enrichment, Eu depletion and Sr/Y ratios that are consistent with a subduction origin. The migmatitic gneiss unit, within a zone of highly strained granitoids (straight gneiss) that forms a sliver just east of the suture zone, yielded U-Pb zircon ages ranging from 615 to 589 Ma. This age range is similar to the metamorphic crystallization age of the suture zone rocks. The zircons analyzed display concentric zoning (in CL images) and are inferred to be magmatic. On the other hand, zircon separates from the dioritic gneiss, with grains also showing igneous zoning in CL images, yielded U-Pb zircon crystallization ages ranging from 2.19 to 2.14 Ga. These are the first U-Pb zircon ages to document Paleoproterozoic rocks in the postulated juvenile terrane, west of the Kandi fault zone. Nd model ages of rocks in the suture zone are also consistent with the existence of widespread involvement of older crust in the Pan

  8. Mineralogy, textures, and relative age relationships of massive sulfide ore in the West Shasta district, California ( USA).

    USGS Publications Warehouse

    Howe, S.S.

    1985-01-01

    The Devonian massive sulfide orebodies of the West Shasta district in N California are composed primarily of pyrite, with lesser amounts of other sulfide and gangue minerals. Examination of polished thin sections of more than 100 samples from the Mammoth, Shasta King, Early Bird, Balaklala, Keystone, and Iron Mountain mines suggests that mineralization may be divided into 6 paragenetic stages, the last 5 each separated by an episode of deformation: 1) precipitation of fine-grained, locally colloform and framboidal pyrite and sphalerite; 2) deposition of fine-grained arsenopyrite and coarse-grained pyrite; 3) penetration and local replacement of sulfide minerals of stages 1 and 2 along growth zones and fractures by chalcopyrite, sphalerite, galena, tennantite, pyrrhotite, bornite, and idaite; 4) recrystallization and remobilization of existing minerals; 5) deposition of quartz, white mica, chlorite, and calcite; and 6) formation of bornite, digenite, chalcocite, and covellite during supergene enrichment of several orebodies at the Iron Mountain mine. Mineralogic and textural evidence do not support a second major episode of massive sulfide mineralization during the Permian. -from Author

  9. Geochemistry, strontium isotope data, and potassium-argon ages of the andesite-rhyolite association in the Padang area, West Sumatra

    USGS Publications Warehouse

    Leo, G.W.; Hedge, C.E.; Marvin, R.F.

    1980-01-01

    Quaternary volcanoes in the Padang area on the west coast of Sumatra have produced two-pyroxene, calc-alkaline andesite and volumetrically subordinate rhyolitic and andesitic ash-flow tuffs. A sequence of andesite (pre-caldera), rhyolitic tuff and andesitic tuff, in decreasing order of age, is related to Maninjau caldera. Andesite compositions range from 55.0 to 61.2% SiO2 and from 1.13 to 2.05% K2O. Six K-Ar whole-rock age determinations on andesites show a range of 0.27 ?? 0.12 to 0.83 ?? 0.42 m.y.; a single determination on the rhyolitic ashflow tuff gave 0.28 ?? 0.12 m.y. Eight 57Sr/26Sr ratios on andesites and rhyolite tuff west of the Semangko fault zone are in the range 0.7056 - 0.7066. These ratios are higher than those elsewhere in the Sunda arc but are comparable to the Taupo volcanic zone of New Zealand and calc-alkaline volcanics of continental margins. An 87Sr/86Sr ratio of 0.7048 on G. Sirabungan east of the Semangko fault is similar to an earlier determination on nearby G. Marapi (0.7047), and agrees with 87Sr/86Sr ratios in the rest of the Sunda arc. The reason for this distribution of 87Sr/86Sr ratios is unknown. The high 87Sr/86Sr ratios are tentatively regarded to reflect a crustal source for the andesites, while moderately fractionated REE patterns with pronounced negative Eu anomalies suggest a residue enriched in plagioclase with hornblende and/or pyroxenes. Generation of associated andesite and rhyolite could have been caused by hydrous fractional melting of andesite or volcanogenic sediments under adiabatic decompression. ?? 1980.

  10. High-boiling arenes of Paleozoic petroleum of West Siberia

    SciTech Connect

    Golovko, A.K.; Kam'yanov, V.F.; Korobitsina, L.L.; Kurakolova, E.A.; Rusinova, G.V.; Petrov, Al. A.

    1984-01-01

    A number of petroleum deposits have been found recently in the southern regions of West Siberia, in carbonate reservoirs of the Paleozoic age; certain aspects of increasing petroleum output in the field are related to these deposits. The general characteristics of Paleozoic petroleums of West Siberia are fairly varied, these petroleums usually have lower sulfur and resin contents but contain more was than petroleums from the Mesozoic deposits in the upper strata. No detailed study has so far, apparently, been carried out of the hydrocarbon composition of higher fractions of Paleozoic petroleums of the regio using physico-chemical methods. Accordingly, the composition of aromatic components of medium and high-boiling petroleum distillates of the Maloich deposit are examined since these are one of the first Paleozoic deposits put to industrial use.

  11. Application of Reservoir Characterization and Advanced Technology to Improve Recovery and Economics in a Lower Quality Shallow Shelf Carbonate Reservoir, Class II

    SciTech Connect

    Hickman, T. Scott; Justice, James J.; Egg, Rebecca

    2001-08-07

    The Oxy operated Class 2 Project at West Welch Project is designed to demonstrate how the use of advanced technology can improve the economics of miscible CO2 injection projects in lower quality Shallow Shelf Carbonate reservoirs. The research and design phase (Budget Period 1) primarily involved advanced reservoir demonstration characterization. The current demonstration phase (Budget Period 2) is the implementation of the reservoir management plan for an optimum miscible CO2 flood design based on the reservoir characterization.

  12. basement reservoir geometry and properties

    NASA Astrophysics Data System (ADS)

    Walter, bastien; Geraud, yves; Diraison, marc

    2017-04-01

    Basement reservoirs are nowadays frequently investigated for deep-seated fluid resources (e.g. geothermal energy, groundwater, hydrocarbons). The term 'basement' generally refers to crystalline and metamorphic formations, where matrix porosity is negligible in fresh basement rocks. Geothermal production of such unconventional reservoirs is controlled by brittle structures and altered rock matrix, resulting of a combination of different tectonic, hydrothermal or weathering phenomena. This work aims to characterize the petro-structural and petrophysical properties of two basement surface analogue case studies in geological extensive setting (the Albert Lake rift in Uganda; the Ifni proximal margin of the South West Morocco Atlantic coast). Different datasets, using field structural study, geophysical acquisition and laboratory petrophysical measurements, were integrated to describe the multi-scale geometry of the porous network of such fractured and weathered basement formations. This study points out the multi-scale distribution of all the features constituting the reservoir, over ten orders of magnitude from the pluri-kilometric scale of the major tectonics structures to the infra-millimetric scale of the secondary micro-porosity of fractured and weathered basements units. Major fault zones, with relatively thick and impermeable fault core structures, control the 'compartmentalization' of the reservoir by dividing it into several structural blocks. The analysis of these fault zones highlights the necessity for the basement reservoirs to be characterized by a highly connected fault and fracture system, where structure intersections represent the main fluid drainage areas between and within the reservoir's structural blocks. The suitable fluid storage areas in these reservoirs correspond to the damage zone of all the fault structures developed during the tectonic evolution of the basement and the weathered units of the basement roof developed during pre

  13. Distribution, lithology and ages of late Cenozoic volcanism on the eastern margin of the Great Basin, West-Central Utah

    SciTech Connect

    Nash, W.P.

    1986-01-01

    The eastern margin of the Basin and Range province in central Utah is the locus of late Cenozoic volcanic activity and has witnessed several volcanic episodes within the last three million years. The Twin Peaks volcanic center became active 2.7 m.y. ago producing rhyodacite and rhyolite from a shallow silicic magma body accompanied by voluminous eruptions of basalt. Between about 1 and 0.3 m.y. ago there were eruptions of high silica rhyolite from a deep-seated magma source beneath the Mineral Mountains together with primitive and strongly fractionated mafic magmas of the Cove Fort subprovince. Within this volcanic area are two localities, Roosevelt Hot Springs and Sulfurdale, which have high temperature waters at or near the surface. To the north in the Black Rock Desert, volcanism extended from 1.5 m.y to only several hundred years ago. The activity was dominated by basaltic eruptions, but the area contains the youngest known rhyolite body in Utah (0.4 m.y.). Volcanic vents are located along major crustal discontinuities in the Black Rock Desert, along ring fracture systems at Twin Peaks, and are aligned along trends of north-south normal faulting in the Mineral Mountains and Cove Fort areas. The localization of volcanism is consistent with high strain rates on a regional scale associated with extension of the Basin and Range. The variety of lithologies observed is consistent with a model of fundamentally basaltic magmatism which augments melting in the lower crust to produce silicic magmas. The majority of the mafic magmas that reach the surface are modified by fractionation with the most primitive varieties erupted to the west.

  14. The Association of Age and Gender with Risk Factors of Noncommunicable Diseases among Employees in West of Iran

    PubMed Central

    Khademi, Nahid; Babanejad, Mehran; Asadmobini, Atefeh; Karim, Hossein

    2017-01-01

    Background: The relationships that age and gender share with risk factors (RFs) of noncommunicable diseases (NCDs) were assessed among a large-scale employ in Western Iran. Methods: In this epidemiologic cross-sectional study, 7129 employees from Kermanshah Province were assessed using a census method in 2012. Data on RFs of NCD were collected using a standard questionnaire. Demographic information, diet, physical activity, tobacco use, and history of hypertension, history of diabetes, cardiovascular diseases, osteoporosis, and cancer were studied. Results: The proportion of ≥5 servings of fruits and vegetables consumption per day was lower in higher ages (P = 0.001), and this proportion was greater in females than males (72.1% vs. 47.8%; P < 0.0001). Tobacco use was more in higher ages and was higher among males than females (13.3% vs. 0.6%; P < 0.0001). Overweight and obesity prevalence increased in higher ages and was more prominent among males than females (67.8% vs. 55.3%; P < 0.0001). Overall, the prevalence of having 3–5 RFs was greater among those with ≥55 years and among males than females (20.4% vs. 6.6%; P < 0.0001). Conclusions: The prevalence of major RFs of NCDs was greater among older persons and male participants. More preventive programs such as health education on employees of Kermanshah are recommended. PMID:28299033

  15. Mapping the risk of anaemia in preschool-age children: the contribution of malnutrition, malaria, and helminth infections in West Africa.

    PubMed

    Magalhães, Ricardo J Soares; Clements, Archie C A

    2011-06-01

    Childhood anaemia is considered a severe public health problem in most countries of sub-Saharan Africa. We investigated the geographical distribution of prevalence of anaemia and mean haemoglobin concentration (Hb) in children aged 1-4 y (preschool children) in West Africa. The aim was to estimate the geographical risk profile of anaemia accounting for malnutrition, malaria, and helminth infections, the risk of anaemia attributable to these factors, and the number of anaemia cases in preschool children for 2011. National cross-sectional household-based demographic health surveys were conducted in 7,147 children aged 1-4 y in Burkina Faso, Ghana, and Mali in 2003-2006. Bayesian geostatistical models were developed to predict the geographical distribution of mean Hb and anaemia risk, adjusting for the nutritional status of preschool children, the location of their residence, predicted Plasmodium falciparum parasite rate in the 2- to 10-y age group (Pf PR(2-10)), and predicted prevalence of Schistosoma haematobium and hookworm infections. In the four countries, prevalence of mild, moderate, and severe anaemia was 21%, 66%, and 13% in Burkina Faso; 28%, 65%, and 7% in Ghana, and 26%, 62%, and 12% in Mali. The mean Hb was lowest in Burkina Faso (89 g/l), in males (93 g/l), and for children 1-2 y (88 g/l). In West Africa, severe malnutrition, Pf PR(2-10), and biological synergisms between S. haematobium and hookworm infections were significantly associated with anaemia risk; an estimated 36.8%, 14.9%, 3.7%, 4.2%, and 0.9% of anaemia cases could be averted by treating malnutrition, malaria, S. haematobium infections, hookworm infections, and S. haematobium/hookworm coinfections, respectively. A large spatial cluster of low mean Hb (<80 g/l) and maximal risk of anaemia (>95%) was predicted for an area shared by Burkina Faso and Mali. We estimate that in 2011, approximately 6.7 million children aged 1-4 y are anaemic in the three study countries. By mapping the distribution

  16. Mapping the Risk of Anaemia in Preschool-Age Children: The Contribution of Malnutrition, Malaria, and Helminth Infections in West Africa

    PubMed Central

    Soares Magalhães, Ricardo J.; Clements, Archie C. A.

    2011-01-01

    Background Childhood anaemia is considered a severe public health problem in most countries of sub-Saharan Africa. We investigated the geographical distribution of prevalence of anaemia and mean haemoglobin concentration (Hb) in children aged 1–4 y (preschool children) in West Africa. The aim was to estimate the geographical risk profile of anaemia accounting for malnutrition, malaria, and helminth infections, the risk of anaemia attributable to these factors, and the number of anaemia cases in preschool children for 2011. Methods and Findings National cross-sectional household-based demographic health surveys were conducted in 7,147 children aged 1–4 y in Burkina Faso, Ghana, and Mali in 2003–2006. Bayesian geostatistical models were developed to predict the geographical distribution of mean Hb and anaemia risk, adjusting for the nutritional status of preschool children, the location of their residence, predicted Plasmodium falciparum parasite rate in the 2- to 10-y age group (Pf PR2–10), and predicted prevalence of Schistosoma haematobium and hookworm infections. In the four countries, prevalence of mild, moderate, and severe anaemia was 21%, 66%, and 13% in Burkina Faso; 28%, 65%, and 7% in Ghana, and 26%, 62%, and 12% in Mali. The mean Hb was lowest in Burkina Faso (89 g/l), in males (93 g/l), and for children 1–2 y (88 g/l). In West Africa, severe malnutrition, Pf PR2–10, and biological synergisms between S. haematobium and hookworm infections were significantly associated with anaemia risk; an estimated 36.8%, 14.9%, 3.7%, 4.2%, and 0.9% of anaemia cases could be averted by treating malnutrition, malaria, S. haematobium infections, hookworm infections, and S. haematobium/hookworm coinfections, respectively. A large spatial cluster of low mean Hb (<80 g/l) and maximal risk of anaemia (>95%) was predicted for an area shared by Burkina Faso and Mali. We estimate that in 2011, approximately 6.7 million children aged 1–4 y are anaemic in the three

  17. Zircon U-Pb age of the Pescadero felsite: A late Cretaceous igneous event in the forearc, west-central California Coast Ranges

    USGS Publications Warehouse

    Ernst, W.G.; Martens, U.C.; McLaughlin, R.J.; Clark, J.C.; Moore, Diane E.

    2011-01-01

    Weathered felsite is associated with the late Campanian-Maastrichtian Pigeon Point Formation near Pescadero, California. Poorly exposed, its age and correlation are uncertain. Is it part of the Pigeon Point section west of the San Gregorio-Hosgri fault? Does it rest on Nacimiento block basement? Is it dextrally offset from the Oligocene Cambria Felsite, ~185 km to the southeast? Why is a calc-alkaline hypabyssal igneous rock intrusive into the outboard accretionary prism? To address these questions, we analyzed 43 oscillatory-zoned zircon crystals from three incipiently recrystallized pumpellyite ?? prehnite ?? laumontite-bearing Pescadero felsite samples by sensitive high-resolution ion microprobe-reverse geometry (SHRIMPRG) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) techniques. Thirty-three zircons gave late Mesozoic U-Pb ages, with single-grain values ranging from 81 to 167 Ma; ten have pre-Mesozoic, chiefl y Proterozoic ages. A group of the four youngest Pescadero zircons yielded an apparent maximum igneous age of ca. 86-90 Ma. Refl ecting broad age scatter and presence of partly digested sandstone inclusions, we interpret the rest of the zircons (perhaps all) as xenocrysts. Twenty-three zircons were separated and analyzed from two samples of the similar Cambria Felsite, yielding a unimodal 27 Ma U-Pb age. Clearly, the origin of the Upper Oligocene Cambria Felsite is different from that of the Upper Cretaceous Pescadero felsite; these rocks are not correlated, and do not constrain displacement along the San Gregorio-Hosgri fault. Peak ages differ slightly, but relative probability curves for Mesozoic and pre-Mesozoic Pescadero zircons compare well, for example, with abundant U-Pb age data for detrital zircons from Franciscan metaclastic strata ~100 km to the east in the Diablo Range- San Francisco Bay area, San Joaquin Great Valley Group turbidites, Upper Cretaceous Nacimiento block Franciscan strata, and Upper Cretaceous

  18. Application of integrated reservoir management and reservoir characterization to optimize infill drilling

    SciTech Connect

    1997-04-01

    This project has used a multi-disciplinary approach employing geology, geophysics, and engineering to conduct advanced reservoir characterization and management activities to design and implement an optimized infill drilling program at the North Robertson (Clearfork) Unit in Gaines County, Texas. The activities during the first Budget Period consisted of developing an integrated reservoir description from geological, engineering, and geostatistical studies, and using this description for reservoir flow simulation. Specific reservoir management activities were identified and tested. The geologically targeted infill drilling program currently being implemented is a result of this work. A significant contribution of this project is to demonstrate the use of cost-effective reservoir characterization and management tools that will be helpful to both independent and major operators for the optimal development of heterogeneous, low permeability shallow-shelf carbonate (SSC) reservoirs. The techniques that are outlined for the formulation of an integrated reservoir description apply to all oil and gas reservoirs, but are specifically tailored for use in the heterogeneous, low permeability carbonate reservoirs of West Texas.

  19. Aging, culture, and memory for socially meaningful item-context associations: an East-West cross-cultural comparison study.

    PubMed

    Yang, Lixia; Li, Juan; Spaniol, Julia; Hasher, Lynn; Wilkinson, Andrea J; Yu, Jing; Niu, Yanan

    2013-01-01

    Research suggests that people in Eastern interdependent cultures process information more holistically and attend more to contextual information than do people in Western independent cultures. The current study examined the effects of culture and age on memory for socially meaningful item-context associations in 71 Canadians of Western European descent (35 young and 36 older) and 72 native Chinese citizens (36 young and 36 older). All participants completed two blocks of context memory tasks. During encoding, participants rated pictures of familiar objects. In one block, objects were rated either for their meaningfulness in the independent living context or their typicality in daily life. In the other block, objects were rated for their meaningfulness in the context of fostering relationships with others or for their typicality in daily life. The encoding in each block was followed by a recognition test in which participants identified pictures and their associated contexts. The results showed that Chinese outperformed Canadians in context memory, though both culture groups showed similar age-related deficits in item and context memory. The results suggest that Chinese are at an advantage in memory for socially meaningful item-context associations, an advantage that continues from young adulthood into old age.

  20. Aging, Culture, and Memory for Socially Meaningful Item-Context Associations: An East-West Cross-Cultural Comparison Study

    PubMed Central

    Yang, Lixia; Li, Juan; Spaniol, Julia; Hasher, Lynn; Wilkinson, Andrea J.; Yu, Jing; Niu, Yanan

    2013-01-01

    Research suggests that people in Eastern interdependent cultures process information more holistically and attend more to contextual information than do people in Western independent cultures. The current study examined the effects of culture and age on memory for socially meaningful item-context associations in 71 Canadians of Western European descent (35 young and 36 older) and 72 native Chinese citizens (36 young and 36 older). All participants completed two blocks of context memory tasks. During encoding, participants rated pictures of familiar objects. In one block, objects were rated either for their meaningfulness in the independent living context or their typicality in daily life. In the other block, objects were rated for their meaningfulness in the context of fostering relationships with others or for their typicality in daily life. The encoding in each block was followed by a recognition test in which participants identified pictures and their associated contexts. The results showed that Chinese outperformed Canadians in context memory, though both culture groups showed similar age-related deficits in item and context memory. The results suggest that Chinese are at an advantage in memory for socially meaningful item-context associations, an advantage that continues from young adulthood into old age. PMID:23593288

  1. Lung Transfer Factor in Middle Aged Asymptomatic Male Smokers of a City from West India: A Cross-Sectional Study

    PubMed Central

    Gadhavi, Bhakti P.; Mehta, Hemant B.; Shah, Chinmay J.; Gokhale, Pradnya A.; Makwana, Amit H.

    2016-01-01

    Introduction Smoking is an increasingly popular indulgence in India. Assessment by routine spirometry falls short of direct functional parameter like Diffusion Lung Capacity (DLC), also known as lung transfer factor (LTF). Aim To measure LTF amongst middle aged male smokers and to study various correlates for it. Materials and Methods Total of 45 asymptomatic male current smokers were enrolled for this cross-sectional study conducted at pulmonary function testing lab of Physiology Department of our college. Smoking history was evaluated and smoking index was defined by product of number smoked per day and years smoked. We used instrument Ultima PFX of Medgraphic Company. After pre syringe calibration LTF was measured by Methane mixture using protocols of ATS. Parameters measured were Dlco-uncorrected, corrected and normalized to VA (alveolar volume). Results were compared for statistical significance and significance was set as p <0.05. Results In case group of 45(25 bidi and 20 cigarette smokers) mean age was 30 years, mean duration was 8 years, mean smoking index was 60. We found small insignificant decline in actual LTF values than predicted which was not significantly different between bidi and cigarette smokers. Duration, age and intensity of smoking were negatively and significantly correlated with LTF value while anthropometric parameters were not. Conclusion Smoking adversely affects LTF in young asymptomatic current male smoker that further declines with severity of smoking and with duration regardless of type of smoking. With years to come, these alterations can largely be prevented by smoking cessation, at least theoretically. PMID:27134864

  2. Colonization history and clonal richness of asexual Daphnia in periglacial habitats of contrasting age in West Greenland.

    PubMed

    Haileselasie, Tsegazeabe H; Mergeay, Joachim; Weider, Lawrence J; Jeppesen, Erik; De Meester, Luc

    2016-07-01

    Due to climate change, Arctic ice sheets are retreating. This leads to the formation of numerous new periglacial ponds and lakes, which are being colonized by planktonic organisms such as the water flea Daphnia. This system provides unique opportunities to test genotype colonization dynamics and the genetic assemblage of populations. Here, we studied clonal richness of the Daphnia pulex species complex in novel periglacial habitats created by glacial retreat in the Jakobshavn Isbrae area of western Greenland. Along a 10 km transect, we surveyed 73 periglacial habitats out of which 61 were colonized by Daphnia pulex. Hence, for our analysis, we used 21 ponds and 40 lakes in two clusters of habitats differing in age (estimated <50 years vs. >150 years). We tested the expectation that genetic diversity would be low in recently formed (i.e. young), small habitats, but would increase with increasing age and size. We identified a total of 42 genetically distinct clones belonging to two obligately asexual species of the D. pulex species complex: D. middendorffiana and the much more abundant D. pulicaria. While regional clonal richness was high, most clones were rare: 16 clones were restricted to a single habitat and the five most widespread clones accounted for 68% of all individuals sampled. On average, 3·2 clones (range: 1-12) coexisted in a given pond or lake. There was no relationship between clonal richness and habitat size when we controlled for habitat age. Whereas clonal richness was statistically higher in the cluster of older habitats when compared with the cluster of younger ponds and lakes, most young habitats were colonized by multiple genotypes. Our data suggest that newly formed (periglacial) ponds and lakes are colonized within decades by multiple genotypes via multiple colonization events, even in the smallest of our study systems (4 m(2) ). © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society.

  3. Birthweight by gestational age and its effect on perinatal mortality in white and in Punjabi births: experience at a district general hospital in West London 1967-1975.

    PubMed

    Dawson, I; Golder, R Y; Jonas, E G

    1982-11-01

    At Hillingdon Hospital in West London two main ethnic groups: 'UK' (i.e. white European) and 'Indian' (i.e. Punjabi) account for the bulk of obstetric work load. Birthweight by gestational age graphs were calculated for some 6000 Indian and 18000 UK infants born between 1967 and 1975 inclusive. A mean weight difference at term favoured UK male babies by 240 g and UK female babies by 230 g. Though the crude perinatal results in the two populations were not significantly different, the perinatal mortality of infants less than 2500 g in birthweight was lower in the Indian than the UK population, particularly in the 1500-2400 g group. This is attributed to a levelling off in intrauterine growth from 36 to 37 weeks gestation onwards in Indian compared with UK pregnancies, so that they were more mature than UK births of the same weight. However light-for-dates births, defined as birthweights below the 10th centile of weight-for-gestational age on their own ethnic and sex specific standards pose problems, irrespective of ethnic background.

  4. Assessment of iodine and non-iodine deficiency hypothyroidism in women of reproductive ages in the sub-Himalayan plains of West Bengal.

    PubMed

    Ray, Arabinda; Biswas, Utpal; Mukherjee, Ashoke; Sarker, Krishna Chandra; Samajdar, Kausik; Mukherjee, Gautam

    2009-01-01

    Indian women of reproductive age groups commonly suffer from hypothyroidism which may be due to iodine or non iodine deficiency causes. This study was undertaken with a view to ascertain the leading cause of hypothyroidism in women of reproductive age group residing in the sub-Himalayan plain areas of Darjeeling district of West Bengal. Serum TSH, T4, T3 and Urinary Iodine Excretion (UIE) levels were measured in 101 non pregnant women. Our results reveal that among 37.62% (n=38) of bio-chemically established hypothyroid women; majority 76.32% (n=29) are suffering from iodine deficiency and the rest 23.68% (n=9) have Hypothyroidism due to other causes. Moreover, iodine deficiency persists among 57.42% (n=58) of the women in our study. We conclude that iodine deficiency disorders are still a major problem in this region and hypothyroidism due to iodine deficiency is more prevalent than the non iodine deficiency causes. Hence lacunae in the iodine supplementation process needs to be reviewed.

  5. Dawsonite occurrences related to the age and origin of CO2 influx in sandstone reservoirs: A case study in the Songliao Basin, NE China

    NASA Astrophysics Data System (ADS)

    Li, Fulai; Li, Wenshuai; Yu, Zhichao; Liu, Na; Yang, Huidong; Liu, Li

    2017-01-01

    Dawsonite is often associated with CO2-rich gas reservoirs, and it is regarded as a "trace mineral" for recording migration and accumulation of CO2. Following accepted petrological, mineralogical, and geochemical principles, we used several methods (described herein) to study the Cretaceous dawsonite-bearing sandstone reservoirs in the Songliao Basin, China. We used the ideas of "sequencing" and "timing" to verify the influx stages of CO2 and hydrocarbons, dividing their influx sequence pattern and building a CO2-influx timeframe. First, we determined the stable isotopic ratios of dawsonite and CO2 in gas and oil reservoirs, and found that the CO2 in? dawsonite is of a mantle-derived magma origin. Second, we differentiated an early/late-stage oil and gas influx and a midmantle source influx through the study of diagenetic paragenetic sequences, formation water, and fluid inclusions in the dawsonite-bearing sandstones. Combining burial/thermal-history curves and illite K-Ar dates from the study area, we determined that the early-stage oil and gas influx, late oil and gas influx, and medium CO2 influx occurred at 85-58.8 Ma, 41-20 Ma, and 58.8-41 Ma (Paleocene and Eocene), respectively. Finally, we observed a coupling relationship between CO2 influx and Shuangliao volcanic activities and material compositions, as constrained by volcanic activity history in the basin since the Late Cretaceous.

  6. The habitat of petroleum in the Brazilian marginal and west African basins: A biological marker investigation

    SciTech Connect

    Mello, M.R.; Soldan, A.L. ); Maxwell, J.R. ); Figueira, J. )

    1990-05-01

    A geochemical and biological marker investigation of a variety of oils from offshore Brazil and west Africa, ranging in age from Lower Cretaceous to Tertiary, has been done, with the following aims: (1) assessing the depositional environment of source rocks, (2) correlating the reservoired oils, (3) comparing the Brazilian oils with their west African counterparts. The approach was based in stable isotope data; bulk, elemental, and hydrous pyrolysis results; and molecular studies involving quantitative geological marker investigations of alkanes using GC-MS and GC-MS-MS. The results reveal similarities between groups of oils from each side of the Atlantic and suggest an origin from source rocks deposited in five types of depositional environment: lacustrine fresh water, lacustrine saline water, marine evaporitic/carbonate, restricted marine anoxic, and marine deltaic. In west Africa, the Upper Cretaceous marine anoxic succession (Cenomanian-Santonian) appears to be a major oil producer, but in Brazil it is generally immature. The Brazilian offshore oils have arisen mainly from the pre-salt sequence, whereas the African oils show a balance between origins from the pre-salt and marine sequences. The integration of the geochemical and geological data indicate that new frontiers of hydrocarbon exploration in the west African basins must consider the Tertiary reservoirs in the offshore area of Niger Delta, the reservoirs of the rift sequences in the shallow-water areas of south Gabon, Congo, and Cuanza basins, and the reservoirs from the drift sequences (post-salt) in the deep-water areas of Gabon, Congo Cabinda, and Cuanza basins.

  7. 13. VIEW TO WEST. DETAIL, WEST PIER, WEST APPROACH SPAN, ...

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

    13. VIEW TO WEST. DETAIL, WEST PIER, WEST APPROACH SPAN, LOCKING GEAR AT WEST END OF SWING SPAN. (photographed from boat) - Gianella Bridge, Spanning Sacramento River at State Highway 32, Hamilton City, Glenn County, CA

  8. 41. VIEW FROM END OF FLUME, LOOKING WEST, SHOWING OVERFLOW ...

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

    41. VIEW FROM END OF FLUME, LOOKING WEST, SHOWING OVERFLOW CHUTE ON RIGHT (PARALLEL TO FLUME), RESERVOIR EMBANKMENT IN BACKGROUND, AND HOOKS ON END OF RAILING FOR SPILLBOARDS - Electron Hydroelectric Project, Along Puyallup River, Electron, Pierce County, WA

  9. 46. VIEW, LOOKING WEST FROM DETERIORATED END OF FLUME AT ...

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

    46. VIEW, LOOKING WEST FROM DETERIORATED END OF FLUME AT RESERVOIR'S EAST EDGE, SHOWING DREDGE IN LEFT BACKGROUND, SIDE VIEW OF FOREBAY SHED ON RIGHT - Electron Hydroelectric Project, Along Puyallup River, Electron, Pierce County, WA

  10. VIEW TO WEST FROM AIRFIELD APRON, SHOWING BASE OPERATIONS CONTROL ...

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

    VIEW TO WEST FROM AIRFIELD APRON, SHOWING BASE OPERATIONS CONTROL TOWER (FACILITY NO. 365), AND RESERVOIR HILL BEYOND Hangar NO. 9, AT RIGHT - Hamilton Field, East of Nave Drive, Novato, Marin County, CA

  11. 5. Typical plankcovered flume. View looks west near Luna de ...

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

    5. Typical plank-covered flume. View looks west near Luna de Miel Street. - Lake Hodges Flume, Along San Dieguito River between Lake Hodges & San Dieguito Reservoir, Rancho Santa Fe, San Diego County, CA

  12. 76. PINETREE SIPHON, SECOND AQUEDUCT IN FOREGROUND LOOKING WEST ...

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

    76. PINETREE SIPHON, SECOND AQUEDUCT IN FOREGROUND LOOKING WEST - Los Angeles Aqueduct, From Lee Vining Intake (Mammoth Lakes) to Van Norman Reservoir Complex (San Fernando Valley), Los Angeles, Los Angeles County, CA

  13. 20. Detail, looking west, beneath Trestle 4, showing the metal ...

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

    20. Detail, looking west, beneath Trestle 4, showing the metal flume channel, and the sediment clean-out valve. - Lake Hodges Flume, Along San Dieguito River between Lake Hodges & San Dieguito Reservoir, Rancho Santa Fe, San Diego County, CA

  14. Cosmogenic 10Be ages from the Meirs and Garwood Valleys, Denton Hills, West Antarctica, suggest an absence in LGM Ice Sheet expansion.

    NASA Astrophysics Data System (ADS)

    Fink, David; Joy, Kurt; Storey, Bryan

    2014-05-01

    It has been hypothesised that during interglacials, thinning of the Ross Ice Shelf allowed a more open water environment with increased local precipitation. This resulted in outlet glaciers, which drain the Transantarctic Mountains and fed by the East Antarctic Ice Sheet, advancing during moist warmer periods, apparently out of phase with colder arid dry periods. Significantly the ice core record during these warm periods also shows increased accumulation continent wide The geomorphology of the Denton Hills in the Royal Society Range, West Antarctica, is a result of Miocene fluvial incision reworked by subsequent glacial advances throughout the Quaternary. The Garwood and Miers glacial valleys drain ice across the Denton Hills into the Shelf, and should thus show maximum extent during interstadials. To understand the chronology of late Quaternary glaciations, 15 granitic boulders from terminal moraines were sampled for 10Be and 26Al cosmogenic dating. Obtaining reliable exposure ages of erratics within moraines that represent timing of deposition (i.e. glacial advances) is problematic in polar regions, where glacial activity is principally controlled by ice sheet dynamics. Recycling of previously exposed debris, uncertainty in provenance of glacially transported boulders and a lack of a post-depositional hydrologic process to remove previously exposed material from a valley system, leads to ambiguities in multiple exposure ages from a single coeval glacial landform. More importantly, cold-based ice advance can leave a landform unmodified resulting in young erratics deposited on bedrock that shows weathering and/or inconsistent age-altitude relationships. Primarily, inheritance becomes a difficulty in qualifying exposure ages from polar regions. Preliminary results from the Garwood and Miers Valleys indicate that glaciers in the Denton Hills had begun to retreat from their last maximum positions no later than 23-37 ka, and thus the local last glacial maximum

  15. Style and age of late Oligocene-early Miocene deformation in the southern Stillwater Range, west central Nevada: Paleomagnetism, geochronology, and field relations

    USGS Publications Warehouse

    Hudson, Mark R.; John, David A.; Conrad, James E.; McKee, Edwin H.

    2000-01-01

    Paleomagnetic and geochronologic data combined with geologic mapping tightly restrict the timing and character of a late Oligocene to early Miocene episode of large magnitude extension in the southern Stillwater Range and adjacent regions of west central Nevada. The southern Stillwater Range was the site of an Oligocene to early Miocene volcanic center comprising (1) 28.3 to 24.3 Ma intracaldera ash flow tuffs, lava flows, and subjacent plutons associated with three calderas, (2) 24.8 to 20.7 Ma postcaldera silicic dikes and domes, and (3) unconformably overlying 15.3 to 13.0 Ma dacite to basalt lava flows, plugs, and dikes. The caldera-related tuffs, lava flows, and plutons were tilted 60°-70° either west or east during the initial period of Cenozoic deformation that accommodated over 100% extension. Directions of remanent magnetization obtained from these extrusive and intrusive, caldera-related rocks are strongly deflected from an expected Miocene direction in senses appropriate for their tilt. A mean direction for these rocks after tilt correction, however, suggests that they were also affected by a moderate (33.4° ± 11.8°) component of counterclockwise vertical axis rotation. Paleomagnetic data indicate that the episode of large tilting occurred during emplacement of 24.8 to 20.7 Ma postcaldera dikes and domes. In detail, an apparent decrease in rotation with decreasing age of individual, isotopically dated bodies of the postcaldera group indicates that most tilting occurred between 24.4 and 24.2 Ma. The onset of tilting immediately following after the final caldera eruptions suggests that the magmatism and deformation were linked. Deformation was not driven by magma buoyancy, however, because tilting equally affected the caldera systems of different ages, including their plutonic roots. It is more likely that regional extension was focused in the southern Stillwater Range due to magmatic warming and reduction of tensile strength of the brittle crust

  16. A hospital led promotion campaign aimed to increase bicycle helmet wearing among children aged 11–15 living in West Berkshire 1992–98

    PubMed Central

    Lee, A.; Mann, N.; Takriti, R.

    2000-01-01

    Objectives—To evaluate the effect of a bicycle helmet promotion campaign on helmet wearing among cyclists less than 16 years of age from 1992–98. Setting—Reading, West Berkshire, UK. Methods—A hospital led bicycle helmet promotion campaign targeted at 5–15 year olds. The campaign focused on education with active involvement of the children, parents, schools, and safety organisations. Local media and children's celebrities raised the profile of the campaign and a low cost helmet purchase scheme was also set up. A self administered questionnaire survey of 3000, 11–15 year olds was carried out over the period of the campaign. A control group of 3000 teenagers was obtained from a neighbouring area without a helmet campaign. Accident and emergency (A&E) figures were obtained from the local hospital within the campaign area on all children aged under 16 years, attending with bicycle injuries. Unfortunately, no figures were available from the A&E department in the control area. Results—Self reported helmet use among 11–15 years olds living in the campaign area increased from 11% at the start of the campaign to 31% after five years (p<0.001), with no change in the control group. Hospital casualty figures in the campaign area for cycle related head injuries in the under 16 years age group, fell from 112.5/100 000 to 60.8/100 000 (from 21.6% of all cycle injuries to 11.7%; p<0.005). Conclusions—This hospital led community bicycle helmet promotion campaign directed at young people showed an increase in the number of children reporting that they "always" wore their helmet while cycling. There was a significantly higher rate of helmet wearing than in the control area, and a significant reduction in head injuries. PMID:10875675

  17. A hospital led promotion campaign aimed to increase bicycle helmet wearing among children aged 11-15 living in West Berkshire 1992-98.

    PubMed

    Lee, A J; Mann, N P; Takriti, R

    2000-06-01

    To evaluate the effect of a bicycle helmet promotion campaign on helmet wearing among cyclists less than 16 years of age from 1992-98. Reading, West Berkshire, UK. A hospital led bicycle helmet promotion campaign targeted at 5-15 year olds. The campaign focused on education with active involvement of the children, parents, schools, and safety organisations. Local media and children's celebrities raised the profile of the campaign and a low cost helmet purchase scheme was also set up. A self administered questionnaire survey of 3,000, 11-15 year olds was carried out over the period of the campaign. A control group of 3,000 teenagers was obtained from a neighbouring area without a helmet campaign. Accident and emergency (A&E) figures were obtained from the local hospital within the campaign area on all children aged under 16 years, attending with bicycle injuries. Unfortunately, no figures were available from the A&E department in the control area. Self reported helmet use among 11-15 years olds living in the campaign area increased from 11% at the start of the campaign to 31% after five years (p<0.001), with no change in the control group. Hospital casualty figures in the campaign area for cycle related head injuries in the under 16 years age group, fell from 112.5/100,000 to 60.8/100,000 (from 21.6% of all cycle injuries to 11.7%; p<0.005). This hospital led community bicycle helmet promotion campaign directed at young people showed an increase in the number of children reporting that they "always" wore their helmet while cycling. There was a significantly higher rate of helmet wearing than in the control area, and a significant reduction in head injuries.

  18. Seasonal variation in the nutritional status of children aged 6 to 60 months in a resettlement village in West Timor.

    PubMed

    Miller, Jacqueline; Ritchie, Brett; Tran, Cuong; Beggs, Sean; Lada, Christina Olly; Whetter, Kathryn; Cobiac, Lynne

    2013-01-01

    Childhood malnutrition remains a public health issue in Indonesia with a national prevalence of wasting of 13% and stunting of 36%. In rural areas nutritional status depends on local agriculture and may fluctuate in relation to harvest time. The aim of this study was to characterise seasonal variations in nutritional status in two resettlement villages in the Oesao district, Nusa Tenggara Timur. A cross sectional study was conducted in a convenience sample of children after the wet season (March). Children aged 6 to 60 months were assessed for nutritional status using anthropometric and biochemical measures. A subset of these children was re-assessed for anthropometry after the dry season (November). Weight-for-height z scores improved significantly from mean±SD of -1.7± 0.9 in March to -1.3±0.9 in November (p<0.001). There was no significant change in height between seasons. Prevalence of wasting, (weight-for-height z score <-2), was 42% in March and 19% in November (p<0.001). However, stunting rates increased significantly from 42% in March to 45% in November (p<0.001). Thirty six per cent of children were anaemic (Hb level <11 mg/100 mL), 68% were vitamin A deficient (plasma vitamin A level <0.8 μmol/L) and 50% were zinc deficient (plasma zinc <9.94 μmol/L). All children except one were positive for intestinal parasites. These data indicate seasonal changes in anthropometry with inconsistent effects depending on the anthropometric index measured. Wasting and stunting were higher than the national average, alongside high rates of anaemia, zinc and vitamin A deficiencies.

  19. Characterization of oil and gas reservoir heterogeneity

    SciTech Connect

    Not Available

    1991-01-01

    The objective of the cooperative research program is to characterize Alaskan reservoirs in terms of their reserves, physical and chemical properties, geologic configuration and structure, and the development potential. The tasks completed during this period include: (1) geologic reservoir description of Endicott Field; (2) petrographic characterization of core samples taken from selected stratigraphic horizons of the West Sak and Ugnu (Brookian) wells; (3) development of a polydispersed thermodynamic model for predicting asphaltene equilibria and asphaltene precipitation from crude oil-solvent mixtures, and (4) preliminary geologic description of the Milne Point Unit.

  20. New 40Ar-39Ar ages for Basalts From the West Siberian Basin and Links With the Siberian Flood Basalt Province

    NASA Astrophysics Data System (ADS)

    Reichow, M. K.; Saunders, A. D.; White, R. V.; Pringle, M. S.; Al'Mukhamedov, A. I.; Medvedev, A. Y.

    2001-12-01

    The Siberian Traps represent the world's largest subaerial flood basalt province, and may be responsible for the Permo-Triassic mass extinction at 250 Ma (e.g., Campbell et al. 1992 Science 258, 1760). The total extent of the Traps, and whether or not the volcanism is a contributor to the Permo-Triassic mass extinction, are both still matters of debate. Basaltic and gabbroic rocks occur throughout the West Siberian Basin (WSB), but are covered by a thick succession of Mesozoic and Cenozoic sediments, unlike the more accessible Traps on the Siberian craton to the east. We have obtained material from three deep industrial boreholes (Hohryakovskaya, Permyakovskaya, Van Eganskaya), and show that basalts and gabbros from the WSB have ages indistinguishable from the Traps to the east. 40Ar-39Ar dating of plagioclase (from basalts) and phlogopite (from a gabbro) separates from 6 samples from three boreholes give ages of 249.3 to 250.5 Ma (plagioclase) and 253.4 Ma (phlogopite) (relative to GA1550 biotite at 98.79 Ma). The results are obtained by step heating and the apparent plateau ages include more than 90 percent of the total argon released. Two sigma errors are better than 1.0 Ma for 5 of the samples. Normalised to the same standard, these ages are in good agreement with ages obtained for the Siberian Traps (250 Ma: Renne and Basu 1991 Science 253, 176). On the basis of major and trace element data, the basalts from the WSB show affinities with the Nadezhinsky suite (Noril'sk area), which is known to immediately precede the main pulse of volcanism that extruded over large areas of the craton. Limited recovery from the boreholes indicates that the basalts were erupted subaerially or possibly into shallow water (e.g. presence of abundant, large amygdales). Lava flows are at least 20 m thick, indicating voluminous eruptions. The results from the Ar-Ar dating and chemical analysis emphasise a clear correlation between basalts from the WSB and the Siberian Traps. This

  1. West Antarctic Ice Sheet Retreat in the Eastern Ross Sea Concomitant with Meltwater Pulse-1a and -1b Using New Foraminiferal Radiocarbon Ages.

    NASA Astrophysics Data System (ADS)

    DeCesare, M.; Bart, P. J.; Majewski, W.; Rosenheim, B. E.

    2016-12-01

    The timing of Antarctic Ice Sheet retreat and its contribution to post-Last Glacial Maximum global mean sea-level rise remains controversial partly due to the paucity of reliable deglacial chronologies from proximal Antarctic marine basins. Here we present new foraminiferal radiocarbon dates acquired during expedition NBP1502B from the Whales Deep paleo-ice stream trough in the eastern Ross Sea, Antarctica. These 14C ages, tightly constrained by core sedimentology and geomorphic interpretations, show that the West Antarctic Ice Sheet (WAIS) retreated from outer continental shelf in two distinct steps. The first deglacial step occurred by 14,700 ±400 years ago when the WAIS began its retreat from the continental shelf edge to a middle-shelf position 40 km inland. In other words, the first phase of retreat was concomitant with Meltwater Pulse-1a (MWP-1a). This short-distance grounding-line translation suggests that a negligible amount of sea-level-equivalent ice volume was returned to the global ocean from this sector of the WAIS. The second retreat phase occurred at 11,500 ±300 years ago, when the WAIS grounding line abruptly shifted >200 km from the middle shelf to a position south of the modern calving front, concomitant with MWP-1b. This larger-volume ablation event requires that the Whales Deep sector of the WAIS contributed significantly more sea-level-equivalent ice volume during MWP-1b compared to that released during MWP-1a.

  2. National Program for Inspection of Non-Federal Dams. Putnamville Reservoir Dam and Dikes (DAM (MA 00745), East Dike (MA 01297), West Dike (MA 00744), Ipswich River Basin, Danvers, Massachusetts. Phase I Inspection Report.

    DTIC Science & Technology

    1981-08-01

    AND DIKES ii I U The measures outlined above and in Section 7 should be implemented by the Ow-ner within a period of one year after receipt of this...pool: 79.8 79.8 79.8 (5) Full flood control pool: N/A N/A N/A (6) Spillway crest: 79.8 II /A N/A (7) Design surcharge (1977 design) : 80.6 N/A N/A (8...RESERVOIR DAM AND DIKES 9 II I SECTION 2 ENGINEERING DATA 2.1 General. The engineering data available for this Phase I inspection includes as-built

  3. Increases in hepatitis C virus infection related to injection drug use among persons aged ≤30 years - Kentucky, Tennessee, Virginia, and West Virginia, 2006-2012.

    PubMed

    Zibbell, Jon E; Iqbal, Kashif; Patel, Rajiv C; Suryaprasad, Anil; Sanders, Kathy J; Moore-Moravian, Loretta; Serrecchia, Jamie; Blankenship, Steven; Ward, John W; Holtzman, Deborah

    2015-05-08

    Hepatitis C virus (HCV) infection is the most common blood-borne infection in the United States, with approximately three million persons living with current infection. Percutaneous exposure to contaminated blood is the most efficient mode of transmission, and in the United States, injection drug use (IDU) is the primary risk factor for infection. State surveillance reports from the period 2006-2012 reveal a nationwide increase in reported cases of acute HCV infection, with the largest increases occurring east of the Mississippi River, particularly among states in central Appalachia. Demographic and behavioral data accompanying these reports show young persons (aged ≤30 years) from nonurban areas contributed to the majority of cases, with about 73% citing IDU as a principal risk factor. To better understand the increase in acute cases of HCV infection and its correlation to IDU, CDC examined surveillance data for acute case reports in conjunction with analyzing drug treatment admissions data from the Treatment Episode Data Set-Admissions (TEDS-A) among persons aged ≤30 years in four states (Kentucky, Tennessee, Virginia, and West Virginia) for the period 2006-2012. During this period, significant increases in cases of acute HCV infection were found among persons in both urban and nonurban areas, with a substantially higher incidence observed each year among persons residing in nonurban areas. During the same period, the proportion of treatment admissions for opioid dependency increased 21.1% in the four states, with a significant increase in the proportion of persons admitted who identified injecting as their main route of drug administration (an increase of 12.6%). Taken together, these increases indicate a geographic intersection among opioid abuse, drug injecting, and HCV infection in central Appalachia and underscore the need for integrated health services in substance abuse treatment settings to prevent HCV infection and ensure that those who are infected

  4. Status of Norris Reservoir

    SciTech Connect

    Not Available

    1990-09-01

    This is one in a series of reports prepared by the Tennessee Valley Authority (TVA) for those interested in the conditions of TVA reservoirs. This overview of Norris Reservoir summarizes reservoir and watershed characteristics, reservoir uses, conditions that impair reservoir uses, water quality and aquatic biological conditions, and activities of reservoir management agencies. This information was extracted from the most up-to-date publications and data available, and from interviews with water resource professionals in various federal, state, and local agencies, and in public and private water supply and wastewater treatment facilities. 14 refs., 3 figs.

  5. Mesozoic to Cenozoic U-Pb zircon ages from Graham Land, West Antarctica: the magmatic evolution of the Antarctic Peninsula batholith

    NASA Astrophysics Data System (ADS)

    Bastias, Joaquin; Spikings, Richard; Ulianov, Alex; Schaltegger, Urs; Grunow, Anne; Hervé, Francisco

    2017-04-01

    The plutonic rocks of the Antarctic Peninsula form one of the major intrusive bodies located along the circum-Pacific rim. Spanning ages of ˜240 to 9 Ma and emplaced over 1300 km long and 200 km wide along Graham and Palmer Land, these rocks represents a key unit to understand the magmatic and tectonic evolution of the Antarctic Peninsula. In the north, the plutons intrude Paleozoic- Mesozoic low-grade meta-sedimentary rocks, and intrudes schists and ortho- and paragneisses with Triassic to Carboniferous metamorphic ages, further south. The origin of the arc of Antarctic Peninsula has been in dispute since the interpretation of Vaughan and Storey (2000) who suggested that these plutonic rocks are part of an allochthonous arc, contradicting the traditional interpretation that these rocks are autochthonous and are part of the continental arc which formed along the southern margin of Gondwana (Suarez, 1976). We will address the magmatic and tectonic evolution of the Antarctic Peninsula by providing crystallization ages (zircon U-Pb and hornblende 40Ar/39Ar) of the main plutonic units, together with the characterization of the tectonic environment within which magmatism was occurring (geochemical studies and isotopic tracing). We present 45 LA-ICP-MS U-Pb (zircon) and 4 40Ar/39Ar (hornblende) dates of plutons and dikes from the west coast of the northern Antarctic Peninsula and the South Shetland Islands. Their geochemical composition shows affinities with calc-alkaline, supra-subduction zone rocks (Pearce et al., 1984). The U-Pb zircon ages range between ˜160 Ma (Stonington Island) to ˜9 Ma (Cornwallis Island), with a peak in the Early Cretaceous (Albian and Aptian). Upper Jurassic to Eocene intrusions were emplaced in a constant, approximately stationary position. Magmatism displaced ˜50km westwards during the Miocene, which is currently exposed on Watkin Island (˜22 Ma), Snodgrass Island (˜19 Ma), Litchfield Island (˜19 Ma) and Cornwallis Island (˜26 Ma

  6. Vaccine coverage and determinants of incomplete vaccination in children aged 12-23 months in Dschang, West Region, Cameroon: a cross-sectional survey during a polio outbreak.

    PubMed

    Russo, Gianluca; Miglietta, Alessandro; Pezzotti, Patrizio; Biguioh, Rodrigue Mabvouna; Bouting Mayaka, Georges; Sobze, Martin Sanou; Stefanelli, Paola; Vullo, Vincenzo; Rezza, Giovanni

    2015-07-10

    Inadequate immunization coverage with increased risk of vaccine preventable diseases outbreaks remains a problem in Africa. Moreover, different factors contribute to incomplete vaccination status. This study was performed in Dschang (West Region, Cameroon), during the polio outbreak occurred in October 2013, in order to estimate the immunization coverage among children aged 12-23 months, to identify determinants for incomplete vaccination status and to assess the risk of poliovirus spread in the study population. A cross-sectional household survey was conducted in November-December 2013, using the WHO two-stage sampling design. An interviewer-administered questionnaire was used to obtain information from consenting parents of children aged 12-23 months. Vaccination coverage was assessed by vaccination card and parents' recall. Chi-square test and multilevel logistic regression model were used to identify the determinants of incomplete immunization status. Statistical significance was set at p < 0.05. Overall, 3248 households were visited and 502 children were enrolled. Complete immunization coverage was 85.9% and 84.5%, according to card plus parents' recall and card only, respectively. All children had received at least one routine vaccination, the OPV-3 (Oral Polio Vaccine) coverage was >90%, and 73.4% children completed the recommended vaccinations before 1-year of age. In the final multilevel logistic regression model, factors significantly associated with incomplete immunization status were: retention of immunization card (AOR: 7.89; 95% CI: 1.08-57.37), lower mothers' utilization of antenatal care (ANC) services (AOR:1.25; 95% CI: 1.07-63.75), being the ≥ 3(rd) born child in the family (AOR: 425.4; 95% CI: 9.6-18,808), younger mothers' age (AOR: 49.55; 95% CI: 1.59-1544), parents' negative attitude towards immunization (AOR: 20.2; 95% CI: 1.46-278.9), and poorer parents' exposure to information on vaccination (AOR: 28.07; 95 % CI: 2.26-348.1). Longer

  7. APPLICATION OF RESERVOIR CHARACTERIZATION AND ADVANCED TECHNOLOGY TO IMPROVE RECOVERY AND ECONOMICS IN A LOWER QUALITY SHALLOW SHELF SANANDRES RESERVOIR

    SciTech Connect

    Unknown

    2003-01-15

    The Class 2 Project at West Welch was designed to demonstrate the use of advanced technologies to enhance the economics of improved oil recovery (IOR) projects in lower quality Shallow Shelf Carbonate (SSC) reservoirs, resulting in recovery of additional oil that would otherwise be left in the reservoir at project abandonment. Accurate reservoir description is critical to the effective evaluation and efficient design of IOR projects in the heterogeneous SSC reservoirs. Therefore, the majority of Budget Period 1 was devoted to reservoir characterization. Technologies being demonstrated include: (1) Advanced petrophysics; (2) Three-dimensional (3-D) seismic; (3) Crosswell bore tomography; (4) Advanced reservoir simulation; (5) Carbon dioxide (CO{sub 2}) stimulation treatments; (6) Hydraulic fracturing design and monitoring; (7) Mobility control agents.

  8. A West African Link

    ERIC Educational Resources Information Center

    Cook, Angela; Davies, Penny

    2003-01-01

    The authors visited Ghana in West Africa to strengthen a link established the previous year as part of Channel 4's "On the Line" project. The initial link established in 1999/2000 was between an all-age special school in Enfield and a similar school in Accra. Over the course of that year further partnerships were created between five UK…

  9. A West African Link

    ERIC Educational Resources Information Center

    Cook, Angela; Davies, Penny

    2003-01-01

    The authors visited Ghana in West Africa to strengthen a link established the previous year as part of Channel 4's "On the Line" project. The initial link established in 1999/2000 was between an all-age special school in Enfield and a similar school in Accra. Over the course of that year further partnerships were created between five UK…

  10. Age of Volcanism of the Wolverine Volcanic Center, West-Central Yukon Territory, Canada and its Implications for the History of Yukon River

    NASA Astrophysics Data System (ADS)

    Jackson, L. E.; Huscroft, C. A.; Ward, B. C.; Villeneuve, M.

    2008-12-01

    New Ar-Ar ages determined on the Wolverine Creek volcanic center (WC) establishes a middle Pliocene initiation of volcanism for the Fort Selkirk Volcanic Group (FSVG), Fort Selkirk area, west-central Yukon, Canada. WC was active between 4.34±0.06 and 2.98±0.05 Ma. Lava flows repeatedly descended Wolverine Creek valley and flowed into the Yukon River Valley (YRV) during the eruptive life of WC. The total thickness of WC lava flows in YRV decreases in a northward direction and the overall elevation of the surface of the highest flow at any point descends northward as well. Total thickness is up to 100 m in the canyon of Wolverine Creek with a surface elevation of approximately 550 m a.s.l. WC lava flows extend to the confluence of Yukon River with Pelly River 7 km north of the Wolverine Creek confluence with YRV. The lava fill has a total thickness of about 80 m at this northern limit with a surface elevation of 520 m a.s.l. The youngest flow there is dated at 3.05±0.07 Ma. The flows in this area show a general upward compositional change from basanite to alkali olivine basalt which is characteristic of WC. The thinning of the flows and decrease in elevation in a northward direction in YRV is consistent with the contemporary flow direction of Yukon River. Furthermore, the WC flows presumably extended farther down YRV (north and west) prior to erosional truncation. In contrast, lava flows are absent south (up contemporary flow of Yukon River) from the confluence of Wolverine Creek with YRV. This is consistent with the pattern of quenching that would be expected for any lava flow that enters YRV from Wolverine Creek and encounters a north-flowing Yukon River. This pattern is similar to those of lava flows from the younger Pelly and Black Creek FSVG eruptive centers immediately downstream of the Yukon River-Pelly River confluence. Similar asymmetries in lava flows that entered river canyons have been reported by others in the western Grand Canyon and for the 200 year

  11. Permian {open_quotes}Wolfcamp{close_quotes} limestone reservoirs: Powell Ranch field, Eastern Midland Basin

    SciTech Connect

    Montgomery, S.L.

    1996-09-01

    Deep-water carbonate channel reservoirs form important oil reservoirs along the toe of the Eastern Shelf of the Permian basin in west Texas. In northwestern Glasscock County, these `Wolfcamp` reservoirs are Leonardian (Early Permian) in age and define high-energy channels incised into surrounding carbonate detritus and basinal shale. Porous grain-flow material filling these channels, along with encasing detritus, was derived from the shallow shelf located six miles to the east. Reservoirs are in packstone and grainstone facies and have significant interparticle and moldic porosity. Relevant exploration began in the 1960s, but expanded slowly thereafter due to lack of success caused by complex patterns of channel occurrence. Results of a three-dimensional (3-D) seismic survey conducted in 1990 have greatly enhanced the identification and mapping of productive channels in the Powell Ranch field complex. Wells in this complex are capable of flowing 400-1200 bbl of oil per day, and have reserves ranging from 0.2 to 1.3 MBO. The new 3-D data have improved the relevant geologic model and dramatically increased rates of drilling success. Application of such data to this setting offers a potential model for other parts of the Permian basin.

  12. SACROC Unit CO{sub 2} flood: Multidisciplinary team improves reservoir management and decreases operating costs

    SciTech Connect

    Hawkins, J.T.; Benvegnu, A.J.; Wingate, T.P.; McKamie, J.D.; Pickard, C.D.; Altum, J.T.

    1996-08-01

    The SACROC Unit of the Kelly-Snyder field is located in the Midland basin. The Midland basin is the eastern most of the Permian Basins of west Texas. This field is the largest of the many prolific, Late Pennsylvanian age carbonate buildups that comprise the Horseshoe Atoll. The field, discovered in 1948, encompasses 50,000 acres and contained an estimated original oil in place of 2.8 billion bbl. Waterflooding operations began in 1954 and CO{sub 2} flooding began in 1972. Cumulative recovery has been more than 1.2 billion bbl. The field contains approximately 1,600 wells with about 400 active producers and 240 active injectors. Recent changes implemented by the team have significantly improved operational efficiency at the unit. In addition, recent geologic investigations have finally began to unravel the complex stratigraphy of the reservoir. In 1992, the economic viability of the SACROC Unit was somewhat uncertain. At that time, a multidisciplinary team was formed to improve operational efficiencies and reservoir performance. Better understanding of reservoir geology from detailed biostratigraphic analysis provided the framework to make effective changes. This paper discusses operational efficiency and reservoir exploitation projects implemented by the team.

  13. Large reservoirs: Chapter 17

    USGS Publications Warehouse

    Miranda, Leandro E.; Bettoli, Phillip William

    2010-01-01

    Large impoundments, defined as those with surface area of 200 ha or greater, are relatively new aquatic ecosystems in the global landscape. They represent important economic and environmental resources that provide benefits such as flood control, hydropower generation, navigation, water supply, commercial and recreational fisheries, and various other recreational and esthetic values. Construction of large impoundments was initially driven by economic needs, and ecological consequences received little consideration. However, in recent decades environmental issues have come to the forefront. In the closing decades of the 20th century societal values began to shift, especially in the developed world. Society is no longer willing to accept environmental damage as an inevitable consequence of human development, and it is now recognized that continued environmental degradation is unsustainable. Consequently, construction of large reservoirs has virtually stopped in North America. Nevertheless, in other parts of the world construction of large reservoirs continues. The emergence of systematic reservoir management in the early 20th century was guided by concepts developed for natural lakes (Miranda 1996). However, we now recognize that reservoirs are different and that reservoirs are not independent aquatic systems inasmuch as they are connected to upstream rivers and streams, the downstream river, other reservoirs in the basin, and the watershed. Reservoir systems exhibit longitudinal patterns both within and among reservoirs. Reservoirs are typically arranged sequentially as elements of an interacting network, filter water collected throughout their watersheds, and form a mosaic of predictable patterns. Traditional approaches to fisheries management such as stocking, regulating harvest, and in-lake habitat management do not always produce desired effects in reservoirs. As a result, managers may expend resources with little benefit to either fish or fishing. Some locally

  14. [Population density, age distribution and urbanisation as factors influencing the frequency of home visits--an analysis for Mecklenburg-West Pomerania].

    PubMed

    Heymann, R; Weitmann, K; Weiss, S; Thierfelder, D; Flessa, S; Hoffmann, W

    2009-07-01

    This study examines and compares the frequency of home visits by general practitioners in regions with a lower population density and regions with a higher population density. The discussion centres on the hypothesis whether the number of home visits in rural and remote areas with a low population density is, in fact, higher than in urbanised areas with a higher population density. The average age of the population has been considered in both cases. The communities of Mecklenburg West-Pomerania were aggregated into postal code regions. The analysis is based on these postal code regions. The average frequency of home visits per 100 inhabitants/km2 has been calculated via a bivariate, linear regression model with the population density and the average age for the postal code region as independent variables. The results are based on billing data of the year 2006 as provided by the Association of Statutory Health Insurance Physicians of Mecklenburg-Western Pomerania. In a second step a variable which clustered the postal codes of urbanised areas was added to a multivariate model. The hypothesis of a negative correlation between the frequency of home visits and the population density of the areas examined cannot be confirmed for Mecklenburg-Western Pomerania. Following the dichotomisation of the postal code regions into sparsely and densely populated areas, only the very sparsely populated postal code regions (less than 100 inhabitants/km2) show a tendency towards a higher frequency of home visits. Overall, the frequency of home visits in sparsely populated postal code regions is 28.9% higher than in the densely populated postal code regions (more than 100 inhabitants/km2), although the number of general practitioners is approximately the same in both groups. In part this association seems to be confirmed by a positive correlation between the average age in the individual postal code regions and the number of home visits carried out in the area. As calculated on the

  15. Fracturing high-permeability reservoirs increases productivity

    SciTech Connect

    Dusterhoft, R.G. ); Chapman, B.J. )

    1994-06-20

    Hydraulic fracturing of high-permeability reservoirs has increased long-term hydrocarbon production and reduced sand production in many areas of the world. A key element is the reduction of near well bore drawdown during production. Drawdown, the difference between reservoir and production pressures, is the driving force for flow into the well bore. As drawdown increases because of higher production rates or depletion, formation instability may cause fines and sand to migrate into the well bore region. A greater well bore radius reduces both radial velocity and drawdown. Fracturing beyond the well bore region effectively bypasses the damaged zone, increasing the effective radius of the well bore and enabling higher flow rates with lower drawdown pressures. In essence, the reservoir energy is used more efficiently because the conductive proppant bed bypasses the near well bore restrictions. The paper discusses candidate well selection; proppant selection; sand control; minifrac procedures; spurt losses; fracture design; equipment; case histories in West Africa and offshore Louisiana.

  16. Association between dietary patterns and low bone mineral density among adults aged 50 years and above: findings from the North West Adelaide Health Study (NWAHS).

    PubMed

    Melaku, Yohannes Adama; Gill, Tiffany K; Adams, Robert; Shi, Zumin

    2016-10-01

    Studies on the association between dietary patterns and bone mineral density (BMD) have reported inconsistent findings. Data from the North West Adelaide Health Study, a population-based cohort study undertaken in Australia, were used to assess this association among adults aged 50 years and above. In this specific study, 1182 adults (545 males, 45·9 %) had dietary data collected using a FFQ and also had BMD measurements taken using dual-energy X-ray absorptiometry. Factor analysis with principal component method was applied to ascertain dietary patterns. Two distinct dietary patterns were identified. Pattern 1 ('prudent pattern') was characterised by high intake of fruits, vegetables, sugar, nut-based milk, fish, legumes and high-fibre bread. In contrast, pattern 2 ('Western pattern') was characterised by high levels of processed and red meat, snacks, takeaway foods, jam, beer, soft drinks, white bread, poultry, potato with fat, high-fat dairy products and eggs. Compared with the study participants in the first tertile (T1, lowest consumption) of the prudent pattern, participants in the third tertile (T3) had a lower prevalence of low BMD (prevalence ratio (PR)=0·52; 95 % CI 0·33, 0·83) after adjusting for socio-demographic, lifestyle and behavioural characteristics, chronic conditions and energy intake. Participants in T3 of the Western pattern had a higher prevalence of low BMD (PR=1·68; 95 % CI 1·02, 2·77) compared with those in T1. In contrast to the Western diet, a dietary pattern characterised by high intake of fruits, vegetables and dairy products is positively associated with BMD.

  17. Stream, Lake, and Reservoir Management.

    PubMed

    Dai, Jingjing; Mei, Ying; Chang, Chein-Chi

    2017-10-01

    This review on stream, lake, and reservoir management covers selected 2016 publications on the focus of the following sections: Stream, lake, and reservoir management • Water quality of stream, lake, and reservoirReservoir operations • Models of stream, lake, and reservoir • Remediation and restoration of stream, lake, and reservoir • Biota of stream, lake, and reservoir • Climate effect of stream, lake, and reservoir.

  18. Structural geology of Swift reservoir culmination, Sawtooth Range, Montana

    SciTech Connect

    Singdahlsen, D.S.

    1984-07-01

    Northwest-trending, thrusted and folded rocks of Paleozoic and Mesozoic age comprise the Sawtooth Range of northwestern Montana. The Sawtooth Range is a part of the northern disturbed belt and is characterized by thin-skinned deformation. Stratigraphy plays an important role in the location and character of the various thrust sheets. Major decollement surfaces include the Upper Cambrian, the top of the Devonian, and several horizons within the Mississippian. In the Swift Reservoir area, a broad culmination exposes Cambrian through Cretaceous strata in a series of imbricately stacked, west-dipping thrust sheets. The structural configuration of the culmination appears to be a compound duplex zone with structures north and south of Swift Reservoir dipping away from the culmination. Mapping of the culmination reveals vertical stacking of thrust sheets, and a lateral ramp that forms the southern boundary of the duplex. A structural high in the basement may have resulted in ramping of the thrust sheets and formation of the culmination. Deformation within the thrust sheets is controlled by structural position and by ductility contrasts between the stratigraphic units. Deformation varies widely, ranging from tight overturned folds in the Cambrian units to broad open folds and fractures within the Mississippian. Because of the variation in lithology and ductility, the most intense deformation is observed within the Cambrian units. This deformation is characterized by overturning of folds in the direction of thrust transport, and the development of small-scale kink folds, cleavage, pencil structures, and boundinage.

  19. Status of Cherokee Reservoir

    SciTech Connect

    Not Available

    1990-08-01

    This is the first in a series of reports prepared by Tennessee Valley Authority (TVA) for those interested in the conditions of TVA reservoirs. This overviews of Cherokee Reservoir summarizes reservoir and watershed characteristics, reservoir uses and use impairments, water quality and aquatic biological conditions, and activities of reservoir management agencies. This information was extracted from the most current reports, publications, and data available, and interviews with water resource professionals in various Federal, state, and local agencies and in public and private water supply and wastewater treatment facilities. 11 refs., 4 figs., 1 tab.

  20. Status of Wheeler Reservoir

    SciTech Connect

    Not Available

    1990-09-01

    This is one in a series of status reports prepared by the Tennessee Valley Authority (TVA) for those interested in the conditions of TVA reservoirs. This overview of Wheeler Reservoir summarizes reservoir purposes and operation, reservoir and watershed characteristics, reservoir uses and use impairments, and water quality and aquatic biological conditions. The information presented here is from the most recent reports, publications, and original data available. If no recent data were available, historical data were summarized. If data were completely lacking, environmental professionals with special knowledge of the resource were interviewed. 12 refs., 2 figs.

  1. Geology of the Roswell artesian basin, New Mexico, and its relation to the Hondo Reservoir and Effect on artesian aquifer storage of flood water in Hondo Reservoir

    USGS Publications Warehouse

    Bean, Robert T.; Theis, Charles V.

    1949-01-01

    In the Roswell Basin in southeastern New Mexico artesian water is produced from cavernous zones in the carbonate rocks of the San Andres formation and the lower part of the Chalk Bluff formation, both of Permian age. The Hondo Reservoir, 9 miles west-southwest of Roswell, was completed by the U. S. Bureau of Reclamation in 1907, to store waters of the Rio Hondo for irrigation. The project was not successful, as the impounded water escaped rapidly through holes in the gypsum and limestone of the San Andres formation constituting its floor. Of 27,000 acre~feet that entered the reservoir between 1908 and 1913, only 1,100 acre-feet was drawn Ollt for use, the remainder escaping through the floor of the reservoir. Since 1939, plans have been drawn up by the State Engineer and by Federal agencies to utilize the reservoir to protect Roswell from floods. It has also been suggested that water from the Pecos River might be diverted into underground storage through the reservoir. Sinkholes in the Roswell Basin are largely clustered in areas where gypsum occurs in the bedrock. Collapse of strata is due to solution of underlying rock commonly containing gypsum. Domes occur in gypsiferous strata near Salt Creek. The Bottomless Lakes, sinkhole lakes in the escarpment on the east side of the Pecos, are believed to have developed in north-south hinge-line fractures opened when the westernmost beds in the escarpment collapsed. Collapse was due to solution and removal of gypsiferous rock by artesian water which now fills the lakes.

  2. Demand for long acting and permanent contraceptive methods and associated factors among married women of reproductive age group in Debre Markos Town, North West Ethiopia

    PubMed Central

    2014-01-01

    Background Ethiopia is the second most populous country in sub Saharan Africa with high total fertility rate, and high maternal and child mortality rates. In sub Saharan African countries, including Ethiopia, even though studies show that demand for contraception is high, the practice is low. Particularly, in Ethiopia, despite the fact that practices on long acting and permanent methods are believed to be low, there are limited evidences on the real magnitude of demand for the methods. Methods To assess demand for long acting and permanent contraceptive methods and associated factors among married women of reproductive age group in Debre Markos town, Amhara Regional State, North West Ethiopia, A community based cross sectional study was conducted, from April 08–19, 2012. Systematic sampling technique was used to select 523 study participants. Pre tested structured Amharic version questionnaire was used to collect the data through interview. Both bivariate and multiple logistic regressions were used to identify associated factors. Results Among 519 respondents, 323 (62.2%) were using modern family planning (FP) methods in which 101 (19.5%) were using long acting and permanent contraceptive methods (LAPMs). Among all respondents, 171 (32.9%) had unmet need for LAPMs. The total demand for LAPMs was 272 (52.4%) of which 37.1% were satisfied and 62.9% unsatisfied demand. Being in the older age group (40-44 years) [AOR = 2.8; 95% CI:1.12, 9.55], having no desire for more child [AOR = 20.37; 95% CI:9.28, 44.72], desire to have a child after 2 years [AOR = 6.4; 95%CI:3.04,13.47], not ever heard of modern FP [AOR = 5.73; 95% CI:1.26, 25.91], not ever using of modern FP [AOR = 1.89; 95% CI:1.01, 3.55] and having no spousal discussion in the last six month [AOR = 1.642, 95% CI: 1.049, 2.57) were some of the factors significantly associated with demand for LAPMs. Conclusions Demand and unmet need for LAPMs were high in the study area. Therefore

  3. Demand for long acting and permanent contraceptive methods and associated factors among married women of reproductive age group in Debre Markos Town, North West Ethiopia.

    PubMed

    Bulto, Gizachew Abdissa; Zewdie, Tatek Abate; Beyen, Teresa Kisi

    2014-03-13

    Ethiopia is the second most populous country in sub Saharan Africa with high total fertility rate, and high maternal and child mortality rates. In sub Saharan African countries, including Ethiopia, even though studies show that demand for contraception is high, the practice is low. Particularly, in Ethiopia, despite the fact that practices on long acting and permanent methods are believed to be low, there are limited evidences on the real magnitude of demand for the methods. To assess demand for long acting and permanent contraceptive methods and associated factors among married women of reproductive age group in Debre Markos town, Amhara Regional State, North West Ethiopia, A community based cross sectional study was conducted, from April 08-19, 2012. Systematic sampling technique was used to select 523 study participants. Pre tested structured Amharic version questionnaire was used to collect the data through interview. Both bivariate and multiple logistic regressions were used to identify associated factors. Among 519 respondents, 323 (62.2%) were using modern family planning (FP) methods in which 101 (19.5%) were using long acting and permanent contraceptive methods (LAPMs). Among all respondents, 171 (32.9%) had unmet need for LAPMs. The total demand for LAPMs was 272 (52.4%) of which 37.1% were satisfied and 62.9% unsatisfied demand. Being in the older age group (40-44 years) [AOR = 2.8; 95% CI:1.12, 9.55], having no desire for more child [AOR = 20.37; 95% CI:9.28, 44.72], desire to have a child after 2 years [AOR = 6.4; 95%CI:3.04,13.47], not ever heard of modern FP [AOR = 5.73; 95% CI:1.26, 25.91], not ever using of modern FP [AOR = 1.89; 95% CI:1.01, 3.55] and having no spousal discussion in the last six month [AOR = 1.642, 95% CI: 1.049, 2.57) were some of the factors significantly associated with demand for LAPMs. Demand and unmet need for LAPMs were high in the study area. Therefore raising awareness of the community

  4. An index of reservoir habitat impairment

    USGS Publications Warehouse

    Miranda, L.E.; Hunt, K.M.

    2011-01-01

    Fish habitat impairment resulting from natural and anthropogenic watershed and in-lake processes has in many cases reduced the ability of reservoirs to sustain native fish assemblages and fisheries quality. Rehabilitation of impaired reservoirs is hindered by the lack of a method suitable for scoring impairment status. To address this limitation, an index of reservoir habitat impairment (IRHI) was developed by merging 14 metrics descriptive of common impairment sources, with each metric scored from 0 (no impairment) to 5 (high impairment) by fisheries scientists with local knowledge. With a plausible range of 5 to 25, distribution of the IRHI scores ranged from 5 to 23 over 482 randomly selected reservoirs dispersed throughout the USA. The IRHI reflected five impairment factors including siltation, structural habitat, eutrophication, water regime, and aquatic plants. The factors were weakly related to key reservoir characteristics including reservoir area, depth, age, and usetype, suggesting that common reservoir descriptors are poor predictors of fish habitat impairment. The IRHI is rapid and inexpensive to calculate, provides an easily understood measure of the overall habitat impairment, allows comparison of reservoirs and therefore prioritization of restoration activities, and may be used to track restoration progress. The major limitation of the IRHI is its reliance on unstandardized professional judgment rather than standardized empirical measurements. ?? 2010 US Government.

  5. Marine radiocarbon reservoir age variation in Donax obesulus shells from northern Peru: late Holocene evidence for extended El Niño

    USGS Publications Warehouse

    Etayo-Cadavid, Miguel F.; Andrus, C. Fred T.; Jones, Kevin B.; Hodgins, Gregory W. L.; Sandweiss, Daniel H.; Uceda-Castillo, Sandiago; Quilter, Jeffrey

    2013-01-01

    For at least 6 m.y., El Niño events have posed the greatest environmental risk on the Peruvian coast. A better understanding of El Niño is essential for predicting future risk and growth in this tropical desert. To achieve this we analyzed archaeological and modern pre-bomb shells from the surf clam Donax for the radiocarbon reservoir effect (ΔR) to characterize late Holocene coastal upwelling conditions in northern Peru (8°14′S). Mean ΔR values from these shells suggest that modern upwelling conditions in this region were likely established between A.D. 539 and A.D. 1578. Our radiocarbon data suggest that upwelling conditions ca. A.D. 539 were less intense than those in modern times. The observed coastal water enrichment in 14C may be consequence of frequent strong El Niño events or extended El Niño–like conditions. These ΔR-inferred marine conditions are in agreement with proposed extended El Niño activity in proxy and archaeological records of ca. A.D. 475–530. Extended El Niño conditions have been linked to political destabilization, societal transformation, and collapse of the Moche civilization in northern Peru. A return to such conditions would have significant impacts on the dense population of this region today and in the near future.

  6. Reservoir rehabilitations: Seeking the Fountain of Youth

    USGS Publications Warehouse

    Pegg, Mark A.; Pope, Kevin L.; Powell, L.A.; Turek, Kelly C.; Spurgeon, Jonathan J.; Stewart, Nathaniel T.; Hogberg, Nick P.; Porath, Mark T.

    2017-01-01

    Aging of reservoirs alters the functions, and associated services, of these systems through time. The goal of habitat rehabilitation is often to alter the trajectory of the aging process such that the duration of the desired state is prolonged. There are two important characteristics in alteration of the trajectory—the amplitude relative to current state and the subsequent rate of change, or aging—that ultimately determine the duration of extension for the desired state. Rehabilitation processes largely fall into three main categories: fish community manipulation, water quality manipulation, and physical habitat manipulation. We can slow aging of reservoirs through carefully implemented management actions, perhaps even turning back the hands of time, but we cannot stop aging. We call for new, innovative perspectives that incorporate an understanding of aging processes in all steps of rehabilitation of reservoirs, especially in planning and assessing.

  7. Dolomite reservoirs: Porosity evolution and reservoir characteristics

    SciTech Connect

    Sun, S.Q.

    1995-02-01

    Systematic analyses of the published record of dolomite reservoirs worldwide reveal that the majority of hydrocarbon-producing dolomite reservoirs occurs in (1) peritidal-dominated carbonate, (2) subtidal carbonate associated with evaporitic tidal flat/lagoon, (3) subtidal carbonate associated with basinal evaporite, and (4) nonevaporitic carbonate sequence associated with topographic high/unconformity, platform-margin buildup or fault/fracture. Reservoir characteristics vary greatly from one dolomite type to another depending upon the original sediment fabric, the mechanism by which dolomite was formed, and the extent to which early formed dolomite was modified by post-dolomitization diagenetic processes (e.g., karstification, fracturing, and burial corrosion). This paper discusses the origin of dolomite porosity and demonstrates the porosity evolution and reservoir characteristics of different dolomite types.

  8. Environmental factors regulating the recruitment of walleye Sander vitreus and white bass Morone chrysops in irrigation reservoirs

    USGS Publications Warehouse

    DeBoer, Jason A.; Pope, Kevin L.; Koupal, Keith D.

    2013-01-01

    Understanding the environmental factors that regulate fish recruitment is essential for effective management of fisheries. Generally, first-year survival, and therefore recruitment, is inherently less consistent in systems with high intra- and interannual variability. Irrigation reservoirs display sporadic patterns of annual drawdown, which can pose a substantial challenge to recruitment of fishes. We developed species-specific models using an 18-year data set compiled from state and federal agencies to investigate variables that regulate the recruitment of walleye Sander vitreus and white bass Morone chrysops in irrigation reservoirs in south-west Nebraska, USA. The candidate model set for walleye included only abiotic variables (water-level elevation, minimum daily air temperature during winter prior to hatching, annual precipitation, spring warming rate and May reservoir discharge), and the candidate model set for white bass included primarily biotic variables (catch per unit effort (CPUE) of black crappie Pomoxis nigromaculatus, CPUE of age-0 walleye, CPUE of bluegill Lepomis macrochirus and CPUE of age-3 and older white bass), each of which had a greater relative importance than the single abiotic variable (minimum daily air temperature during winter after hatching). Our findings improve the understanding of the recruitment of fishes in irrigation reservoirs and the relative roles of abiotic and biotic factors.

  9. Detection of West Nile virus in wild birds in Tana River and Garissa Counties, Kenya.

    PubMed

    Nyamwaya, Doris; Wang'ondu, Virginia; Amimo, Joshua; Michuki, George; Ogugo, Moses; Ontiri, Enoch; Sang, Rosemary; Lindahl, Johanna; Grace, Delia; Bett, Bernard

    2016-11-23

    West Nile fever virus is a zoonotic arboviral infection maintained in a sylvatic cycle involving mosquito vectors and birds. It is one the arboviruses whose geographical range is expanding because of climate and land use changes that enhance the densities of mosquitoes and promote mosquito-bird-human interactions. We carried out a survey to determine the reservoirs of WNV among wild birds in Tana River and Garissa counties, Kenya. Blood samples were obtained from 361 randomly trapped wild birds. Using real-time polymerase chain reaction (PCR), all samples were screened for WNV using gene specific primer sets amplifying a portion of the E region of the genome encoding the envelope protein. Sixty five (65) out of 361 birds screened tested positive for WNV on real-time PCR assay. Sequencing of the selected positive samples reveals that the isolated WNV were most closely related to strains isolated from China (2011). A regression analysis indicated that sampling location influenced the occurrence of WNV while species, age, weight and sex of the birds did not have any effect. This study provides baseline information on the existing circulation of WNV in this region among wild bird reservoirs that could spill over to the human population and points to the need for implementation of surveillance programs to map the distribution of the virus among reservoirs. Awareness creation about West Nile fever in this region is important to improve its detection and management.

  10. Indiana continent catheterizable urinary reservoir.

    PubMed

    Castillo, O A; Aranguren, G; Campos-Juanatey, F

    2014-01-01

    Radical pelvic surgery requires continent or incontinent urinary diversion. There are many techniques, but the orthotopic neobladder is the most used. A continent catheterizable urinary reservoir is sometimes a good alternative when this derivation is not possible or not indicated. This paper has aimed to present our experience with the Indiana pouch continent urinary reservoir. The series is made up of 85 patients, 66 women and 19 men, with a mean age of 56 years (31-77 years). Variables analyzed were operating time, estimated blood loss, transfusion rate, hospital stay and peri-operatory complications. The main indication in 49 cases was resolution of complications related to the treatment of cervical cancer. Average operation time was 110.5 minutes (range 80-130 minutes). Mean blood loss was 450 cc (100-1000 cc). Immediate postoperative complications, all of which were treated medically, occurred in 16 patients (18.85%). One patient suffered anastomotic leakage. Hospital stay was 19 days (range 5-60 days) and there was no mortality in the series. Late complications occurred in 26 patients (32%), these being ureteral anastomotic stenosis in 11 cases, cutaneous stoma stenosis in 9 cases and reservoir stones in 6 cases. The Indiana continent catheterizable urinary reservoir is a valid option for the treatment of both urological and gynecological malignancies as well as for the management of pelvic morbidity related to the treatment of pelvic cancers. Copyright © 2013 AEU. Published by Elsevier Espana. All rights reserved.

  11. Reservoir simulation and geochemical study of Cerro Prieto I wells

    SciTech Connect

    Lippmann, M.J. ); Truesdell, A.H. )

    1990-03-01

    Combined reservoir simulation and geochemical data analysis are used to investigate the effects of recharge and other reservoir processes occurring in the western part of the Cerro Prieto, Mexico, geothermal field (i.e., Cerro Prieto I area). Enthalpy-based temperatures and bottomhole temperatures are calculated based on simplified models of the system, considering different reservoir boundary conditions and zones of contrasting initial temperatures and reservoir properties. By matching the computed trends with geothermometer-based temperature and enthalpy histories of producing wells, the main processes active in the western area of Cerro Prieto are identified. This part of the geothermal system is strongly influenced by nearby groundwater aquifers; cooler waters readily recharge the reservoirs. In response to exploitation, the natural influx of cold water into the shallower alpha reservoir is mainly from the west and down Fault L, while the recharge to the deeper beta reservoir in this part of the field, seems to be only lateral, from the west and possibly south. 11 refs., 12 figs.

  12. Horizons West.

    ERIC Educational Resources Information Center

    Kitses, Jim

    The western is the most popular and enduring of Hollywood forms. It is one embodiment of a traditional theme in American culture: the West as both Garden of natural dignity and innocence and also as treacherous Desert resisting the gradual sweep of agrarian progress and community values. Westerns have in common: a) history, America's past; b)…

  13. Horizons West.

    ERIC Educational Resources Information Center

    Kitses, Jim

    The western is the most popular and enduring of Hollywood forms. It is one embodiment of a traditional theme in American culture: the West as both Garden of natural dignity and innocence and also as treacherous Desert resisting the gradual sweep of agrarian progress and community values. Westerns have in common: a) history, America's past; b)…

  14. Application of integrated reservoir management and reservoir characterization to optimize infill drilling. Annual report, June 13, 1994--June 12, 1995

    SciTech Connect

    Pande, P.K.

    1996-11-01

    This project has used a multi-disciplinary approach employing geology, geophysics, and engineering to conduct advanced reservoir characterization and management activities to design and implement an optimized infill drilling program at the North Robertson (Clearfork) Unit in Gaines County, Texas. The activities during the first Budget Period have consisted of developing an integrated reservoir description from geological, engineering, and geostatistical studies, and using this description for reservoir flow simulation. Specific reservoir management activities are being identified and tested. The geologically targeted infill drilling program will be implemented using the results of this work. A significant contribution of this project is to demonstrate the use of cost-effective reservoir characterization and management tools that will be helpful to both independent and major operators for the optimal development of heterogeneous, low permeability shallow-shelf carbonate (SSC) reservoirs. The techniques that are outlined for the formulation of an integrated reservoir description apply to all oil and gas reservoirs, but are specifically tailored for use in the heterogeneous, low permeability carbonate reservoirs of West Texas.

  15. Geothermal reservoir technology

    SciTech Connect

    Lippmann, M.J.

    1985-09-01

    A status report on Lawrence Berkeley Laboratory's Reservoir Technology projects under DOE's Hydrothermal Research Subprogram is presented. During FY 1985 significant accomplishments were made in developing and evaluating methods for (1) describing geothermal systems and processes; (2) predicting reservoir changes; (3) mapping faults and fractures; and (4) field data analysis. In addition, LBL assisted DOE in establishing the research needs of the geothermal industry in the area of Reservoir Technology. 15 refs., 5 figs.

  16. Application of Integrated Reservoir Management and Reservoir Characterization to Optimize Infill Drillings. Annual technical progress report, June 13, 1996 to June 12, 1998

    SciTech Connect

    Nevans, Jerry W.; Blasingame, Tom; Doublet, Louis; Kelkar, Mohan; Freeman, George; Callard, Jeff; Moore, David; Davies, David; Vessell, Richard; Pregger, Brian; Dixon, Bill

    1999-04-27

    Infill drilling of wells on a uniform spacing, without regard to reservoir performance and characterization, does not optimize reservoir development because it fails to account for the complex nature of reservoir heterogeneities present in many low permeability reservoirs, and carbonate reservoirs in particular. New and emerging technologies, such as geostatistical modeling, rigorous decline curve analysis, reservoir rock typing, and special core analysis can be used to develop a 3-D simulation model for prediction of infill locations. Other technologies, such as inter-well injection tracers and magnetic flow conditioners, can also aid in the efficient evaluation and operation of both injection and producing wells. The purpose of this project was to demonstrate useful and cost effective methods of exploitation of the shallow shelf carbonate reservoirs of the Permian Basin located in West Texas.

  17. Middle Jurassic incised valley fill (eolian/estuarine) and nearshore marine petroleum reservoirs, Powder River basin

    SciTech Connect

    Ahlbrandt, T.S.; Fox, J.E.

    1997-07-01

    Paleovalleys incised into the Triassic Spearfish Formation (Chugwater equivalent) are filled with a vertical sequence of eolian, estuarine, and marine sandstones of the Middle Jurassic (Bathonian age) Canyon Springs Sandstone Member of the Sundance Formation. An outcrop exemplifying this is located at Red Canyon in the southern Black Hills, Fall River County, South Dakota. These paleovalleys locally have more than 300 ft of relief and are as much as several miles wide. Because they slope in a westerly direction, and Jurassic seas transgressed into the area from the west there was greater marine-influence and more stratigraphic complexity in the subsurface, to the west, as compared to the Black Hills outcrops. In the subsurface two distinctive reservoir sandstone beds within the Canyon Springs Sandstone Member fill the paleovalleys. These are the eolian lower Canyon Springs unit (LCS) and the estuarine upper Canyon Springs unit (UCS), separated by the marine {open_quotes}Limestone Marker{close_quotes} and estuarine {open_quotes}Brown Shale{close_quotes}. The LCS and UCS contain significant proven hydrocarbon reservoirs in Wyoming (about 500 MMBO in-place in 9 fields, 188 MMBO produced through 1993) and are prospective in western South Dakota, western Nebraska and northern Colorado. Also prospective is the Callovian-age Hulett Sandstone Member which consists of multiple prograding shoreface to foreshore parasequences, as interpreted from the Red Canyon locality. Petrographic, outcrop and subsurface studies demonstrate the viability of both the Canyon Springs Sandstone and Hulett Sandstone members as superior hydrocarbon reservoirs in both stratigraphic and structural traps. Examples of fields with hydrocarbon production from the Canyon Springs in paleovalleys include Lance Creek field (56 MMBO produced) and the more recently discovered Red Bird field (300 MBO produced), both in Niobrara County, Wyoming.

  18. A neglected requirement for optimizing treatment of age-related osteoporosis: Replenishing the skeleton's base reservoir with net base-producing diets.

    PubMed

    Sebastian, Anthony; Frassetto, Lynda A

    2016-06-01

    Osteoporosis is a disorder of bone in which the mass of the bone is reduced and the bone's architecture at the microscopic level is disordered. Together those abnormalities predispose affected individuals to experience fractures despite only minimal trauma (i.e., fragility fractures). Age related osteoporosis is a common type of osteoporosis that occurs with aging in both men and women usually beginning after the age of peak bone mass. Research has found that the disorder can be partially reversed by reducing the net amount of acid that is produced when consuming typical Western diets. However, the amelioration that results has not been so dramatic or so consistent that physicians have adopted the procedure as part of the standard treatment for age-related osteoporosis. We propose that reducing the net acid load from the diet is not sufficient to reverse age related osteoporosis because it fails to supply base needed to restore the large amount of base in bone that had been lost by reacting with the net acid load of the diet that had been consumed for years or decades. Reducing the net acid load from the diet might be expected to have little ameliorative effect or merely slow the progression of the disorder. We hypothesize that both to restore osteoporotic bone to, or nearly to, its pre-disease state, as well as to eliminate the risk of fragility fractures, requires consuming diets that produce net amounts of base to restore the base lost from years to decades of consuming diets that produce net amounts of acid. We hypothesize also that the excess base and attendant subclinical metabolic alkalosis will both stimulate the cellular process of bone formation and suppress the cellular process of bone resorption, and thereby implement the restorative process. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Aging

    PubMed Central

    Park, Dong Choon

    2013-01-01

    Aging is initiated based on genetic and environmental factors that operate from the time of birth of organisms. Aging induces physiological phenomena such as reduction of cell counts, deterioration of tissue proteins, tissue atrophy, a decrease of the metabolic rate, reduction of body fluids, and calcium metabolism abnormalities, with final progression onto pathological aging. Despite the efforts from many researchers, the progression and the mechanisms of aging are not clearly understood yet. Therefore, the authors would like to introduce several theories which have gained attentions among the published theories up to date; genetic program theory, wear-and-tear theory, telomere theory, endocrine theory, DNA damage hypothesis, error catastrophe theory, the rate of living theory, mitochondrial theory, and free radical theory. Although there have been many studies that have tried to prevent aging and prolong life, here we introduce a couple of theories which have been proven more or less; food, exercise, and diet restriction. PMID:24653904

  20. SEISMIC DETERMINATION OF RESERVOIR HETEROGENEITY: APPLICATION TO THE CHARACTERIZATION OF HEAVY OIL RESERVOIRS

    SciTech Connect

    Matthias G. Imhof; James W. Castle

    2005-02-01

    The objective of the project was to examine how seismic and geologic data can be used to improve characterization of small-scale heterogeneity and their parameterization in reservoir models. The study focused on West Coalinga Field in California. The project initially attempted to build reservoir models based on different geologic and geophysical data independently using different tools, then to compare the results, and ultimately to integrate them all. Throughout the project, however, we learned that this strategy was impractical because the different data and model are complementary instead of competitive. For the complex Coalinga field, we found that a thorough understanding of the reservoir evolution through geologic times provides the necessary framework which ultimately allows integration of the different data and techniques.

  1. SEISMIC DETERMINATION OF RESERVOIR HETEROGENEITY: APPLICATION TO THE CHARACTERIZATION OF HEAVY OIL RESERVOIRS

    SciTech Connect

    Matthias G. Imhof; James W. Castle

    2005-02-01

    The objective of the project was to examine how seismic and geologic data can be used to improve characterization of small-scale heterogeneity and their parameterization in reservoir models. The study focused on West Coalinga Field in California. The project initially attempted to build reservoir models based on different geologic and geophysical data independently using different tools, then to compare the results, and ultimately to integrate them all. We learned, however, that this strategy was impractical. The different data and tools need to be integrated from the beginning because they are all interrelated. This report describes a new approach to geostatistical modeling and presents an integration of geology and geophysics to explain the formation of the complex Coalinga reservoir.

  2. Conservation and sediment yield on the Fort Cobb reservoir watershed

    USDA-ARS?s Scientific Manuscript database

    Prior to about 1950, conservation practices on the Fort Cobb Reservoir watershed in West-Central Oklahoma were few and mostly demonstration type projects. Extensive soil conservation measures were implemented in the second half of the 20th century. Fortuitously, the U.S. Geological Survey collecte...

  3. Impacts of climate and land use change on reservoir sedimentation

    USDA-ARS?s Scientific Manuscript database

    Impacts of evolving climate and implementation of upstream soil conservation measures on sedimentation of the Fort Cobb Reservoir in West-Central Oklahoma are investigated. Conservation practices before the 1950s were few. Between 1950 and 2008, extensive soil conservation measures were implemented...

  4. 33 CFR 211.81 - Reservoir areas.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) Kanopolis Reservoir Area, Kansas. (h) Arkabutla Reservoir Area, Mississippi. (i) Enid Reservoir Area... Reservoir, Oklahoma. Reconveyance of Land or Interests Therein Acquired for Grapevine, Garza-Little Elm...

  5. 95. BOUQUET RESERVOIR LOOKING UP VALLEY TO RESERVOIR LOOKING EAST ...

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

    95. BOUQUET RESERVOIR LOOKING UP VALLEY TO RESERVOIR LOOKING EAST - Los Angeles Aqueduct, From Lee Vining Intake (Mammoth Lakes) to Van Norman Reservoir Complex (San Fernando Valley), Los Angeles, Los Angeles County, CA

  6. Reservoir model for Hillsboro gas storage field management

    USGS Publications Warehouse

    Udegbunam, Emmanuel O.; Kemppainen, Curt; Morgan, Jim; ,

    1995-01-01

    A 3-dimensional reservoir model is used to understand the behavior of the Hillsboro Gas Storage Field and to investigate the field's performance under various future development. Twenty-two years of the gas storage reservoir history, comprising the initial gas bubble development and seasonal gas injection and production cycles, are examined with a full-field, gas water, reservoir simulation model. The results suggest that the gas-water front is already in the vicinity of the west observation well that increasing the field's total gas-in-place volume would cause gas to migrate beyond the east, north and west observation well. They also suggest that storage enlargement through gas injection into the lower layers may not prevent gas migration. Moreover, the results suggest that the addition of strategically-located new wells would boost the simulated gas deliverabilities.

  7. EXPLOITATION AND OPTIMIZATION OF RESERVOIR PERFORMANCE IN HUNTON FORMATION, OKLAHOMA

    SciTech Connect

    Mohan Kelkar

    2002-03-31

    The West Carney Field in Lincoln County, Oklahoma is one of few newly discovered oil fields in Oklahoma. Although profitable, the field exhibits several unusual characteristics. These include decreasing water-oil ratios, decreasing gas-oil ratios, decreasing bottomhole pressures during shut-ins in some wells, and transient behavior for water production in many wells. This report explains the unusual characteristics of West Carney Field based on detailed geological and engineering analyses. We propose a geological history that explains the presence of mobile water and oil in the reservoir. The combination of matrix and fractures in the reservoir explains the reservoir's flow behavior. We confirm our hypothesis by matching observed performance with a simulated model and develop procedures for correlating core data to log data so that the analysis can be extended to other, similar fields where the core coverage may be limited.

  8. Boone Reservoir bacteriological assessment

    SciTech Connect

    Crouch, H.A.

    1990-03-01

    Since 1984, the bacteriological water quality of Boone Reservoir has improved. The actual reservoir pool consistently meets State bacteriological criteria for fecal coliform. Areas of the reservoir that remain impacted by high fecal coliform densities are the riverine portions upstream from SFHRM 35 on the South Fork Holston arm and WRM 13 on the Watauga River am of the reservoir. Improvements have resulted from a combined effort of water resource agencies, local municipalities, and private citizens. Both TVA and the TDHE have conducted monitoring programs over the last six years to assess the condition of the reservoir. Wastewater treatment facility improvements have been made by the cities of Bristol, Tennessee and Virginia, Bluff City, Elizabethton, and Johnson City to increase treatment efficiency and thereby improve Boone Reservoir water quality. Storm runoff events were correlated with elevated fecal coliform measurements in the Boone River watershed, with the greatest impact observed on the Watauga River arm and in the upper portion of the South Fork Holston River arm of the reservoir. Storm events increased the occurrence of wastewater bypasses from the Elizabethton STP and are primarily responsible for the high fecal coliform counts on the Watauga arm. However, nonpoint sources of pollution including animal waste and effluent from malfunctioning septic tank systems may also have a significant impact on Boone Reservoir water quality.

  9. Reservoir Inflation Schedule

    SciTech Connect

    Ponden, Raymond F.

    1991-11-22

    Inflation of the reservoir is to begin on Friday afternoon, November 22 and continue through mid day on Monday, November 25. Inflation of the reservoir shall be accomplished by using only injection pump, HP-2. NOTE: Under no circumstances should injection pump, HP-1 be operated.

  10. Geothermal reservoir engineering research

    NASA Technical Reports Server (NTRS)

    Ramey, H. J., Jr.; Kruger, P.; Brigham, W. E.; London, A. L.

    1974-01-01

    The Stanford University research program on the study of stimulation and reservoir engineering of geothermal resources commenced as an interdisciplinary program in September, 1972. The broad objectives of this program have been: (1) the development of experimental and computational data to evaluate the optimum performance of fracture-stimulated geothermal reservoirs; (2) the development of a geothermal reservoir model to evaluate important thermophysical, hydrodynamic, and chemical parameters based on fluid-energy-volume balances as part of standard reservoir engineering practice; and (3) the construction of a laboratory model of an explosion-produced chimney to obtain experimental data on the processes of in-place boiling, moving flash fronts, and two-phase flow in porous and fractured hydrothermal reservoirs.

  11. EXPLOITATION AND OPTIMIZATION OF RESERVOIR PERFORMANCE IN HUNTON FORMATION, OKLAHOMA

    SciTech Connect

    Mohan Kelkar

    2003-04-01

    West Carney Field produces from Hunton Formation. All the wells produce oil, water and gas. The main objective of this study is to understand the unique behavior observed in the field. This behavior includes: (1) Decrease in WOR over time; (2) Decrease in GOR at initial stages; (3) High decline rates of oil and gas; and (4) strong hydrodynamic connectivity between wells. This report specifically addresses two issues relevant to our understanding of the West Carney reservoir. By using core and log data as well as fluorescence information, we demonstrate that our hypothesis of how the reservoir is formed is consistent with these observations. Namely, oil migrated in water wet reservoir, over time, oil changed the wettability of some part of the reservoir, oil eventually leaked to upper formations prompting re-introduction of water into reservoir. Because of change in wettability, different pore size distributions responded differently to water influx. This hypothesis is consistent with fluorescence and porosity data, as we explain it in this quarterly report. The second issue deals with how to best calculate connected oil volume in the reservoir. The log data does not necessarily provide us with relevant information regarding oil in place. However, we have developed a new material balance technique to calculate the connected oil volume based on observed pressure and production data. By using the technique to four different fields producing from Hunton formation, we demonstrate that the technique can be successfully applied to calculate the connected oil in place.

  12. Environmental flows in the context of small reservoirs in Ghana

    NASA Astrophysics Data System (ADS)

    Gao, Y.; Kirshen, P.; Vogel, R.; Walker, P.

    2009-04-01

    Modification of rivers by dams reduces the magnitude and frequency of floods, and impacts the entire flow regime. In many cases, these modifications have adversely affected the ecological and hydrological integrity of the watershed as well as impacting food security and livelihood choices of the local community. There is now an increasing consensus that modification to river flows needs to be balanced with maintenance of essential water-dependent ecological services. Many small multi-purpose reservoirs have been built in West Africa, where rainfall is highly variable, and droughts and flash floods are frequent. These small reservoirs are an important source of water for domestic use, livestock watering, small-scale irrigation and other beneficial uses in rural communities. The small reservoirs are hydrologically linked by their associated stream network. The reservoirs alter the hydrology of the streams and the groundwater resources within the region. When an individual reservoir is considered, alteration to the entire watershed is usually not significant. However, when considered as a system, together the small reservoirs store a significant quantity of water and influence downstream flows. The small reservoirs have rarely been considered as a system, thus little consideration has been given to their collective impact on the natural environment and livelihoods of the local population in the long term. Furthermore, the impact is difficult to quantify given the diffuse nature of the small reservoirs. Therefore, a comprehensive environmental flow assessment is needed to investigate the effect of the small reservoirs as a system on the watershed, and appropriate water policy should be formulated to implement the finding from the assessment. Our project is specifically aimed at addressing this topic. We will present a case study conducted in the Upper East Region of Ghana and will discuss the findings on the hydrological, ecological and socio-economic implications of

  13. West Africa

    NASA Technical Reports Server (NTRS)

    2002-01-01

    With its vast expanses of sand, framed by mountain ranges and exposed rock, northwestern Africa makes a pretty picture when viewed from above. This image was acquired by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra spacecraft. The Canary Islands can be seen on the left side of the image just off Africa's Atlantic shore. The light brown expanse running through the northern two thirds of the image is the Sahara Desert. The desert runs up against the dark brown Haut Atlas mountain range of Morocco in the northwest, the Atlantic Ocean to the west and the semi-arid (light brown pixels) Sahelian region in the South. The Sahara, however, isn't staying put. Since the 1960s, the desert has been expanding into the Sahelian region at a rate of up to 6 kilometers per year. In the 1980s this desert expansion, combined with over cultivation of the Sahel, caused a major famine across west Africa. Over the summer months, strong winds pick up sands from the Sahara and blow them across the Atlantic as far west as North America, causing air pollution in Miami and damaging coral reefs in the Bahamas and the Florida Keys. The white outlines on the map represent country borders. Starting at the top-most portion of the map and working clockwise, the countries shown are Morocco, Western Sahara, Mauritania, Senegal, Mali, Burkina Fasso, Nigeria, Mali (again), and Algeria. Image by Reto Stockli, Robert Simmon, and Brian Montgomery, NASA Earth Observatory, based on data from MODIS

  14. Carboniferous and older carbonate rocks: Lithofacies, extent, and reservoir quality: Chapter CC in The oil and gas resource potential of the Arctic National Wildlife Refuge 1002 area, Alaska

    USGS Publications Warehouse

    Dumoulin, Julie A.

    1999-01-01

    Carboniferous and older carbonate rocks are potential hydrocarbon reservoir facies for four plays in the 1002 area of the Arctic National Wildlife Refuge. These rocks include several units in the pre-Carboniferous basement and the Carboniferous Lisburne Group. Data from exploratory wells west of the 1002 area, outcrops south of the 1002 area, seismic lines, and well logs are synthesized herein to infer carbonate lithofacies, extent, and reservoir character beneath the northeastern Arctic coastal plain.A chiefly shallow-water basement carbonate succession of Late Proterozoic through Early Devonian age (Katakturuk Dolomite, Nanook Limestone, and Mount Copleston Limestone) is interpreted to be present beneath much of the south-central 1002 area; it reaches 3,700 m thick in outcrop and is the primary reservoir for the Deformed Franklinian Play. A more heterogeneous lithologic assemblage of uncertain age forms basement in the northwestern part of the 1002 area; well data define three subunits that contain carbonate intervals 5- 50 m thick. These strata are prospective reservoirs for the Undeformed Franklinian Play and could also be reservoirs for the Niguanak- Aurora Play. Regional lithologic correlations suggest a Cambrian-Late Proterozoic(?) age for subunits one and two, and a slightly younger, later Cambrian-Silurian age for subunit three. Seismic and well data indicate that subunit one overlies subunit two and is overlain by subunit three. The Mississippian and Pennsylvanian Lisburne Group, a predominantly carbonate platform succession as much as 1 km thick, is projected beneath the southernmost part of the 1002 area and is a potential reservoir for the Ellesmerian Thrust-belt and Niguanak-Aurora Plays.Carbonate rocks in the 1002 area probably retain little primary porosity but may have locally well developed secondary porosity. Measured reservoir parameters in basement carbonate strata are low (porosity generally ≤ 5%; permeability ≤ 0.2 md) but drill

  15. Single-well evaluation program for micellar/polymer recovery, Main and 99 West Pools, West Coyote field, California

    SciTech Connect

    Holland, K.M.; Porter, L.T.

    1983-01-01

    The Main and 99 West pools of the West Coyote field were selected as promising candidates for a micellar-polymer recovery project. Waterfloods initiated in 1961 are nearing their economic limit, with a current watered-oil ratio of 45. Well No. MC 374 was drilled in a water-out portion of the Main and 99 West reservoirs to accomplish an evaluation program with the following objectives: (1) provide data for an improved geologic model; (2) estimate current oil in place; and (3) determine the effectiveness of micellar-polymer chemicals in displacing residual oil. Well No. MC 374 was extensively cored and logged to provide the necessary geologic and reservoir data. A multi-well interference test was conducted to confirm reservoir continuity near the test well. Displacement tests were run in 2 intervals with micellar-polymer chemicals. 13 references.

  16. Perspective, environmental view looking from the intersection of West Lanvale ...

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

    Perspective, environmental view looking from the intersection of West Lanvale Street and North Carrollton Avenue - Reformed Episcopal Church of the Rock of Ages, 1210 West Lanvale Street, Baltimore, Independent City, MD

  17. Reservoir Temperature Estimator

    SciTech Connect

    Palmer, Carl D.

    2014-12-08

    The Reservoir Temperature Estimator (RTEst) is a program that can be used to estimate deep geothermal reservoir temperature and chemical parameters such as CO2 fugacity based on the water chemistry of shallower, cooler reservoir fluids. This code uses the plugin features provided in The Geochemist's Workbench (Bethke and Yeakel, 2011) and interfaces with the model-independent parameter estimation code Pest (Doherty, 2005) to provide for optimization of the estimated parameters based on the minimization of the weighted sum of squares of a set of saturation indexes from a user-provided mineral assemblage.

  18. APPLICATION OF RESERVOIR CHARACTERIZATION AND ADVANCED TECHNOLOGY TO IMPROVE RECOVERY AND ECONOMICS IN A LOWER QUALITY SHALLOW SHELF SAN ANDRES RESERVOIR

    SciTech Connect

    T. Scott Hickman; James J. Justice

    2001-06-16

    The Class 2 Project at West Welch was designed to demonstrate the use of advanced technologies to enhance the economics of improved oil recovery (IOR) projects in lower quality Shallow Shelf Carbonate (SSC) reservoirs, resulting in recovery of additional oil that would otherwise be left in the reservoir at project abandonment. Accurate reservoir description is critical to the effective evaluation and efficient design of IOR projects in the heterogeneous SSC reservoirs. Therefore, the majority of Budget Period 1 was devoted to reservoir characterization. Technologies being demonstrated include: (1) Advanced petrophysics; (2) Three-dimensional (3-D) seismic; (3) Crosswell bore tomography; (4) Advanced reservoir simulation; (5) Carbon dioxide (CO{sub 2}) stimulation treatments; (6) Hydraulic fracturing design and monitoring; and (7) Mobility control agents.

  19. APPLICATION OF RESERVOIR CHARACTERIZATION AND ADVANCED TECHNOLOGY TO IMPROVE RECOVERY AND ECONOMICS IN A LOWER QUALITY SHALLOW SHELF SAN ANDRES RESERVOIR

    SciTech Connect

    T. Scott Hickman

    2003-01-17

    The Class 2 Project at West Welch was designed to demonstrate the use of advanced technologies to enhance the economics of improved oil recovery (IOR) projects in lower quality Shallow Shelf Carbonate (SSC) reservoirs, resulting in recovery of additional oil that would otherwise be left in the reservoir at project abandonment. Accurate reservoir description is critical to the effective evaluation and efficient design of IOR projects in the heterogeneous SSC reservoirs. Therefore, the majority of Budget Period 1 was devoted to reservoir characterization. Technologies being demonstrated include: (1) Advanced petrophysics; (2) Three-dimensional (3-D) seismic; (3) Crosswell bore tomography; (4) Advanced reservoir simulation; (5) Carbon dioxide (CO{sub 2}) stimulation treatments; (6) Hydraulic fracturing design and monitoring; and (7) Mobility control agents.

  20. APPLICATION OF RESERVOIR CHARACTERIZATION AND ADVANCED TECHNOLOGY TO IMPROVE RECOVERY AND ECONOMICS IN A LOWER QUALITY SHALLOW SHELF SAN ANDRES RESERVOIR

    SciTech Connect

    T. Scott Hickman; James J. Justice

    2001-12-11

    The Class 2 Project at West Welch was designed to demonstrate the use of advanced technologies to enhance the economics of improved oil recovery (IOR) projects in lower quality Shallow Shelf Carbonate (SSC) reservoirs, resulting in recovery of additional oil that would otherwise be left in the reservoir at project abandonment. Accurate reservoir description is critical to the effective evaluation and efficient design of IOR projects in the heterogeneous SSC reservoirs. Therefore, the majority of Budget Period 1 was devoted to reservoir characterization. Technologies being demonstrated include: (1) Advanced petrophysics; (2) Three-dimensional (3-D) seismic; (3) Crosswell bore tomography; (4) Advanced reservoir simulation; (5) Carbon dioxide (CO{sub 2}) stimulation treatments; (6) Hydraulic fracturing design and monitoring; and (7) Mobility control agents.

  1. APPLICATION OF RESERVOIR CHARACTERIZATION AND ADVANCED TECHNOLOGY TO IMPROVE RECOVERY AND ECONOMICS IN A LOWER QUALITY SHALLOW SHELF SAN ANDRES RESERVOIR

    SciTech Connect

    T. Scott Hickman; James J. Justice

    2001-08-10

    The Class 2 Project at West Welch was designed to demonstrate the use of advanced technologies to enhance the economics of improved oil recovery (IOR) projects in lower quality Shallow Shelf Carbonate (SSC) reservoirs, resulting in recovery of additional oil that would otherwise be left in the reservoir at project abandonment. Accurate reservoir description is critical to the effective evaluation and efficient design of IOR projects in the heterogeneous SSC reservoirs. Therefore, the majority of Budget Period 1 was devoted to reservoir characterization. Technologies being demonstrated include: (1) Advanced petrophysics; (2) Three-dimensional (3-D) seismic; (3) Crosswell bore tomography; (4) Advanced reservoir simulation; (5) Carbon dioxide (CO{sub 2}) stimulation treatments; (6) Hydraulic fracturing design and monitoring; and (7) Mobility control agents.

  2. APPLICATION OF RESERVOIR CHARACTERIZATION AND ADVANCED TECHNOLOGY TO IMPROVE RECOVERY AND ECONOMICS IN A LOWER QUALITY SHALLOW SHELF SAN ANDRES RESERVOIR

    SciTech Connect

    Raj Kumar; Keith Brown; T. Scott Hickman; James J. Justice

    2000-04-27

    The Class 2 Project at West Welch was designed to demonstrate the use of advanced technologies to enhance the economics of improved oil recovery (IOR) projects in lower quality Shallow Shelf Carbonate (SSC) reservoirs, resulting in recovery of additional oil that would otherwise be left in the reservoir at project abandonment. Accurate reservoir description is critical to the effective evaluation and efficient design of IOR projects in the heterogeneous SSC reservoirs. Therefore, the majority of Budget Period 1 was devoted to reservoir characterization. Technologies being demonstrated include: (1) Advanced petrophysics; (2) Three-dimensional (3-D) seismic; (3) Crosswell bore tomography; (4) Advanced reservoir simulation; (5) Carbon dioxide (CO{sub 2}) stimulation treatments; (6) Hydraulic fracturing design and monitoring; and (7) Mobility control agents.

  3. Reservoir characterization of Pennsylvanian sandstone reservoirs. Final report

    SciTech Connect

    Kelkar, M.

    1995-02-01

    This final report summarizes the progress during the three years of a project on Reservoir Characterization of Pennsylvanian Sandstone Reservoirs. The report is divided into three sections: (i) reservoir description; (ii) scale-up procedures; (iii) outcrop investigation. The first section describes the methods by which a reservoir can be described in three dimensions. The next step in reservoir description is to scale up reservoir properties for flow simulation. The second section addresses the issue of scale-up of reservoir properties once the spatial descriptions of properties are created. The last section describes the investigation of an outcrop.

  4. Fingerprinting Persistent Turbidity in Sheep Creek Reservoir, Owhyee, Nevada

    NASA Astrophysics Data System (ADS)

    Ransom, R. N.; Hooper, R. L.; Kerner, D.; Nicols, S.

    2007-12-01

    Sheep Creek Reservoir near Owyhee, NV is historically a quality rainbow trout fishery. Persistent high-turbidity has been an issue since a major storm event in 2005 resulted in surface water runoff into the Reservoir. The high turbidity is adversely impacting the quality of the fishery. Initial turbidity measurements in 2005 were upwards of 80NTU and these numbers have only decreased to 30NTU over the past two summers. Field parameters indicate the turbidity is associated with high total suspended solids (TSS) and not algae. Five water samples collected from around the reservoir during June, 2007 indicated uniform TSS values in the range of 5 to 12mg/L and oriented powder x-ray diffraction(XRD) and transmission electron microscopy(TEM) analyses of suspended sediment shows very uniform suspended particulate mineralogy including smectite, mixed layer illite/smectite (I/S), discrete illite, lesser amounts of kaolin, sub-micron quartz and feldspar. Diatoms represent a ubiquitous but minor component of the suspended solids. Six soil samples collected from possible source areas around the reservoir were analyzed using both XRD and TEM to see if a source area for the suspended solids could be unambiguously identified. Soils on the east side of the reservoir contain smectite and mixed layer I/S but very little of the other clays. The less than 2 micron size fraction from soils collected from a playa on the topographic bench immediately to the west of the reservoir show a mineralogic finger-print essentially identical to the current suspended sediment. The suspended sediment probably originates on the bench to the west of the reservoir and cascades into the reservoir over the topographic break during extreme storm events. The topographic relief, short travel distance and lack of a suitable vegetated buffer zone to the west are all consistent with a primary persistent suspended sediment source from the west. Identification of the sediment source allows for design of a cost

  5. Geysers reservoir studies

    SciTech Connect

    Bodvarsson, G.S.; Lippmann, M.J.; Pruess, K. )

    1993-01-01

    Lawrence Berkeley Laboratory is conducting several research projects related to issues of interest to The Geysers operators, including those that deal with understanding the nature of vapor-dominated systems, measuring or inferring reservoir processes and parameters, and studying the effects of liquid injection. All of these topics are directly or indirectly relevant to the development of reservoir strategies aimed at stabilizing or increasing production rates of non-corrosive steam, low in non-condensable gases. Three reservoir engineering studies are described in some detail, that is: (a) Modeling studies of heat transfer and phase distribution in two-phase geothermal reservoirs; (b) Numerical modeling studies of Geysers injection experiments; and (c) Development of a dual-porosity model to calculate mass flow between rock matrix blocks and neighboring fractures.

  6. Potential Mammalian Filovirus Reservoirs

    PubMed Central

    Carroll, Darin S.; Mills, James N.; Johnson, Karl M.

    2004-01-01

    Ebola and Marburg viruses are maintained in unknown reservoir species; spillover into human populations results in occasional human cases or epidemics. We attempted to narrow the list of possibilities regarding the identity of those reservoir species. We made a series of explicit assumptions about the reservoir: it is a mammal; it supports persistent, largely asymptomatic filovirus infections; its range subsumes that of its associated filovirus; it has coevolved with the virus; it is of small body size; and it is not a species that is commensal with humans. Under these assumptions, we developed priority lists of mammal clades that coincide distributionally with filovirus outbreak distributions and compared these lists with those mammal taxa that have been tested for filovirus infection in previous epidemiologic studies. Studying the remainder of these taxa may be a fruitful avenue for pursuing the identity of natural reservoirs of filoviruses. PMID:15663841

  7. Uneven-aged management after a half-century of research on the Forest Service Fernow Experimental Forest in West Virgina

    Treesearch

    Thomas M. Schuler

    2014-01-01

    Uneven-age management in forestry refers to a system of management that periodically selects individual trees or small groups of trees for harvest. In general, the concept of uneven-age management entails the sustained yield of forest products while maintaining continuous forest cover. In North America, interest in uneven-age management grew in the second half of the...

  8. Geothermal reservoir simulation

    NASA Technical Reports Server (NTRS)

    Mercer, J. W., Jr.; Faust, C.; Pinder, G. F.

    1974-01-01

    The prediction of long-term geothermal reservoir performance and the environmental impact of exploiting this resource are two important problems associated with the utilization of geothermal energy for power production. Our research effort addresses these problems through numerical simulation. Computer codes based on the solution of partial-differential equations using finite-element techniques are being prepared to simulate multiphase energy transport, energy transport in fractured porous reservoirs, well bore phenomena, and subsidence.

  9. Session: Reservoir Technology

    SciTech Connect

    Renner, Joel L.; Bodvarsson, Gudmundur S.; Wannamaker, Philip E.; Horne, Roland N.; Shook, G. Michael

    1992-01-01

    This session at the Geothermal Energy Program Review X: Geothermal Energy and the Utility Market consisted of five papers: ''Reservoir Technology'' by Joel L. Renner; ''LBL Research on the Geysers: Conceptual Models, Simulation and Monitoring Studies'' by Gudmundur S. Bodvarsson; ''Geothermal Geophysical Research in Electrical Methods at UURI'' by Philip E. Wannamaker; ''Optimizing Reinjection Strategy at Palinpinon, Philippines Based on Chloride Data'' by Roland N. Horne; ''TETRAD Reservoir Simulation'' by G. Michael Shook

  10. Selenium biogeochemistry in reservoirs

    SciTech Connect

    Cutter, G.A. . Dept. of Oceanography)

    1991-05-01

    Three reservoirs (Belews and Hyco in North Carolina and Philpott in Virginia) were sampled over a three-year period by Old Dominion University. Two additional reservoirs (Martin and Murval in Texas) were sampled by Battelle Pacific Northwest Laboratory. Total dissolved selenium, selenite, selenate, Se({minus}II+0), and organic selenide were determined in water samples from the lakes, their primary water inputs, and their outflows. Selenium speciation was also determined in suspended particulate matter, sediments, and plankton. Concentrations of total dissolved selenium are highest in reservoirs associated with power plants, and within these systems selenite is the dominant form of dissolved selenium. In control reservoirs (Philpott and Murval), Se({minus}II+0) is the predominant form of dissolved selenium. Within the sediments, elemental selenium and organic selenides are the dominant forms of particulate selenium. These speciation patterns can be attributed to the primary sources of selenium to the reservoirs (runoff into the control reservoirs and effluents from fly ash ponds into the power plant reservoirs) and to the biogeochemical processing of selenium within the reservoirs. The concentration and speciation of selenium in freshwater depends on selenium source (runoff and effluents), internal cycling in the water column (biotic uptake and regeneration, redox transformations), and output via sedimentation and water outflow. A non-steady state, geochemical computer model was developed to simulate this cycle and to allow predictions of how selenium concentration and speciation would change with time when a variable (e.g., ash pond input) was altered. 29 refs., 51 figs., 4 tabs.

  11. Andrew integrated reservoir description

    SciTech Connect

    Todd, S.P.

    1996-12-31

    The Andrew field is an oil and gas accumulation in Palaeocene deep marine sands in the Central North Sea. It is currently being developed with mainly horizontal oil producers. Because of the field`s relatively small reserves (mean 118 mmbbls), the performance of each of the 10 or so horizontal wells is highly important. Reservoir description work at sanction time concentrated on supporting the case that the field could be developed commercially with the minimum number of wells. The present Integrated Reservoir Description (IRD) is focussed on delivering the next level of detail that will impact the understanding of the local reservoir architecture and dynamic performance of each well. Highlights of Andrew IRD Include: (1) Use of a Reservoir Uncertainty Statement (RUS) developed at sanction time to focus the descriptive effort of both asset, support and contract petrotechnical staff, (2) High resolution biostratigraphic correlation to support confident zonation of the reservoir, (3) Detailed sedimentological analysis of the core including the use of dipmeter to interpret channel/sheet architecture to provide new insights into reservoir heterogeneity; (4) Integrated petrographical and petrophysical investigation of the controls on Sw-Height and relative permeability of water; (5) Fluids description using oil geochemistry and Residual Salt Analysis Sr isotope studies. Andrew IRD has highlighted several important risks to well performance, including the influence of more heterolithic intervals on gas breakthrough and the controls on water coning exerted by suppressed water relative permeability in the transition zone.

  12. Andrew integrated reservoir description

    SciTech Connect

    Todd, S.P.

    1996-01-01

    The Andrew field is an oil and gas accumulation in Palaeocene deep marine sands in the Central North Sea. It is currently being developed with mainly horizontal oil producers. Because of the field's relatively small reserves (mean 118 mmbbls), the performance of each of the 10 or so horizontal wells is highly important. Reservoir description work at sanction time concentrated on supporting the case that the field could be developed commercially with the minimum number of wells. The present Integrated Reservoir Description (IRD) is focussed on delivering the next level of detail that will impact the understanding of the local reservoir architecture and dynamic performance of each well. Highlights of Andrew IRD Include: (1) Use of a Reservoir Uncertainty Statement (RUS) developed at sanction time to focus the descriptive effort of both asset, support and contract petrotechnical staff, (2) High resolution biostratigraphic correlation to support confident zonation of the reservoir, (3) Detailed sedimentological analysis of the core including the use of dipmeter to interpret channel/sheet architecture to provide new insights into reservoir heterogeneity; (4) Integrated petrographical and petrophysical investigation of the controls on Sw-Height and relative permeability of water; (5) Fluids description using oil geochemistry and Residual Salt Analysis Sr isotope studies. Andrew IRD has highlighted several important risks to well performance, including the influence of more heterolithic intervals on gas breakthrough and the controls on water coning exerted by suppressed water relative permeability in the transition zone.

  13. The Tiwi geothermal reservoir: Geology, geochemistry, and response to production

    SciTech Connect

    Hoagland, J.R.; Bodell, J.M. )

    1990-06-01

    The Tiwi geothermal field is located on the Bicol Peninsula of Southern Luzon in the Philippines. The field is associated with the extinct Quaternary stratovolcano Mt. Malinao, one of a chain of volcanos formed as a result of crustal subduction along the Philippine Trench to the east. The geothermal reservoir is contained within a sequence of interlayered andesite flows and pyroclastic deposits that unconformably overlie a basement complex of marine sediments, metamorphic, and intrusive rocks. In its initial state, the Tiwi reservoir was an overpressured liquid-filled system containing near-neutral sodium chloride water at temperatures exceeding 260{degree}C. The reservoir is partially sealed at its top and sides by hydrothermal argillic alteration products and calcite deposition. Isolated portions of the reservoir contain a corrosive acid chloride-sulfate water associated with a distinctive advanced argillic mineral assemblage. Withdrawal of fluid for electricity generation has caused widespread boiling in the reservoir and the formation of steam zones. The resultant solids deposition in wellbores and near-wellbore formation has been mitigated by a combination of mechanical and chemical well stimulation. Mass withdrawal from the reservoir has also caused invasion of cold groundwater into the reservoir through former fluid outflow channels. During 1983-1987, several wells were flooded with cold water and ceased flowing. In response, PGI moved development drilling west to largely unaffected areas and undertook recompletion and stimulation programs. These programs effectively halted the decline in generation by 1988.

  14. [West Nile virus infection].

    PubMed

    Pérez Ruiz, Mercedes; Gámez, Sara Sanbonmatsu; Clavero, Miguel Angel Jiménez

    2011-12-01

    West Nile virus (WNV) is an arbovirus usually transmitted by mosquitoes. The main reservoirs are birds, although the virus may infect several vertebrate species, such as horses and humans. Up to 80% of human infections are asymptomatic. The most frequent clinical presentation is febrile illness, and neuroinvasive disease can occur in less than 1% of cases. Spain is considered a high-risk area for the emergence of WNV due to its climate and the passage of migratory birds from Africa (where the virus is endemic). These birds nest surrounding wetlands where populations of possible vectors for the virus are abundant. Diagnosis of human neurological infections can be made by detection of IgM in serum and/or cerebrospinal fluid samples, demonstration of a four-fold increase in IgG antibodies between acute-phase and convalescent-phase serum samples, or by detection of viral genome by reverse transcription-polymerase chain reaction (especially useful in transplant recipients). Since WNV is a biosafety level 3 agent, techniques that involve cell culture are restricted to laboratories with this level of biosafety, such as reference laboratories. The National Program for the Surveillance of WNV Encephalitis allows the detection of virus circulation among birds and vectors in areas especially favorable for the virus, such as wetlands, and provides information for evaluation of the risk of disease in horses and humans.

  15. Paonia Reservoir Sediment Management

    NASA Astrophysics Data System (ADS)

    Kimbrel, S.; Collins, K.; Williams, C.

    2014-12-01

    Paonia Dam and Reservoir are located on Muddy Creek, a tributary of the North Fork Gunnison River in western Colorado. Since dam closure in 1962, the 2002 survey estimates an annual sedimentation rate of 153,000 m3/y, resulting in a 25% loss of total reservoir capacity. Long before sediment levels completely fill the reservoir, the outlet works have recently plugged with sediment and debris, adversely impacting operations, and emphasizing the urgency of formulating an effective sediment management plan. Starting in 2010-2011, operations were changed to lower the reservoir and flush sediment through the outlet works in early spring before filling the pool for irrigation. Even though the flushing strategy through the long, narrow reservoir (~5 km long and 0.3 km wide) has prevented outlet works plugging, a long term plan is needed to manage inflowing and deposited sediment more efficiently. Reclamation's Sedimentation and River Hydraulics Group is leading an effort to study the past and current sediment issues at Paonia Dam and Reservoir, evaluate feasible sediment management alternatives, and formulate a plan for future operations and monitoring. The study is building on previously collected data and the existing knowledge base to develop a comprehensive, sustainable sediment management plan. The study is being executed in three phases: Phase 1 consisted of an initial site visit to map and sample existing reservoir bottom sediments, a preliminary site evaluation upstream and downstream of the dam, and establishment of time-lapse photo sites and taking initial ground-based photos. Phase 2 includes a bathymetric survey of entire reservoir and 11 km of the river downstream of the dam, continuous suspended sediment monitoring upstream and downstream of the reservoir, and collection of additional core samples of reservoir bottom sediments. Phase 3 involves the evaluation of current and past operations and sediment management practices, evaluate feasible sediment

  16. WEST ELK WILDERNESS, COLORADO.

    USGS Publications Warehouse

    Gaskill, D.L.; Meeves, H.C.

    1984-01-01

    Mineral surveys of the West Elk Wilderness and adjacent areas were conducted and included geologic mapping, geochemical sampling, geophysical studies, and an investigation of mines and prospects. Areas with substantiated mineral-resource potential for bituminous coal with 75 million tons of demonstrated reserves and areas with probable mineral-resource potential for base and precious metals associated with igneous intrusions of Tertiary age were identified in this study. There is little promise for the discovery of oil and gas resources in the area.

  17. Technically recoverable Devonian shale gas in West Virginia

    SciTech Connect

    Kuuskraa, V.A.; Wicks, D.E.

    1984-12-01

    This report evaluates the natural gas potential of the Devonian Age shales of West Virginia. For this, the study: (1) compiles the latest geological and reservoir data to establish the gas in-place; (2) analyzes and models the dominant gas production mechanisms; and (3) examines alternative well stimulation and production strategies for most efficiently recovering the in-place gas. The major findings of the study include the following: (1) The technically recoverable gas from Devonian shale (Huron, Rhinestreet, and Marcellus intervals) in West Virginia is estimated to range from 11 to 44 trillion cubic feet. (2) The Devonian shales in this state entail great geological diversity; the highly fractured, permeable shales in the southwest respond well to traditional development practices while the deep, tight shales in the eastern and northern parts of the state will require new, larger scale well stimulation technology. (3) Beyond the currently developed Huron and Rhinestreet shale intervals, the Marcellus shale offers a third attractive gas zone, particularly in the north central portion of the state. 21 references, 53 figures, 27 tables.

  18. Mid-continent natural gas reservoirs and plays

    SciTech Connect

    Bebout, D.G. )

    1993-09-01

    Natural gas reservoirs of the mid-continent states of Oklahoma, Kansas, and Arkansas (northern part) have produced 103 trillion cubic ft (tcf) of natural gas. Oklahoma has produced the most, having a cumulative production of 71 tcf. The major reservoirs (those that have produced more than 10 billion ft[sup 3]) have been identified and organized into 28 plays based on geologic age, lithology, and depositional environment. The Atlas of Major Midcontinent Gas Reservoirs, published in 1993, provides the documentation for these plays. This atlas was a collaborative effort of the Gas Research Institute; Bureau of Economic Geology. The University of Texas at Austin; Arkansas Geological Commission; Kansas Geological survey; and Oklahoma Geological Survey. Total cumulative production for 530 major reservoirs is 66 tcf associated and nonassociated gas. Oklahoma has the highest production with 39 tcf from 390 major reservoirs, followed by Kansas with 26 tcf from 105 major reservoirs. Most of the mid-continent production is from Pennsylvanian (46%) and Permian (41%) reservoirs; Mississippian reservoirs account for 10% production, and lower Paleozoic reservoirs, 3%. The largest play by far is the Wolfcampian Shallow Shelf Carbonate-Hugoton Embayment play with 25 tcf cumulative production, most of which is from the Hugoton and Panoma fields in Kansas and Guymon-Hugoton gas area in Oklahoma. A total of 53% of the mid-continent gas production is from dolostone and limestone reservoirs; 39% is from sandstone reservoirs. The remaining 8% is from chert conglomerate and granite-wash reservoirs. Geologically based plays established from the distribution of major gas reservoirs provide important support for the extension of productive trends, application of new resource technology to more efficient field development, and further exploration in the mid-continent region.

  19. Middle Jurassic incised valley fill (eolian/estuarine) and nearshore marine petroleum reservoirs, Powder River Basin

    USGS Publications Warehouse

    Ahlbrandt, T.S.; Fox, J.E.

    1997-01-01

    Paleovalleys incised into the Triassic Spearfish Formation (Chugwater equivalent) are filled with a vertical sequence of eolian, estuarine, and marine sandstones of the Middle Jurassic (Bathonian age) Canyon Springs Sandstone Member of the Sundance Formation. An outcrop exemplifying this is located at Red Canyon in the southern Black Hills, Fall River County, South Dakota. These paleovalleys locally have more than 300 ft of relief and are as much as several miles wide. Because they slope in a westerly direction, and Jurassic seas transgressed into the area from the west there was greater marine-influence and more stratigraphic complexity in the subsurface, to the west, as compared to the Black Hills outcrops. In the subsurface two distinctive reservoir sandstone beds within the Canyon Springs Sandstone Member fill the paleovalleys. These are the eolian lower Canyon Springs unit (LCS) and the estuarine upper Canyon Springs unit (UCS), separated by the marine "Limestone Marker" and estuarine "Brown Shale". The LCS and UCS contain significant proven hydrocarbon reservoirs in Wyoming (about 500 MMBO in-place in 9 fields, 188 MMBO produced through 1993) and are prospective in western South Dakota, western Nebraska and northern Colorado. Also prospective is the Callovian-age Hulett Sandstone Member which consists of multiple prograding shoreface to foreshore parasequences, as interpreted from the Red Canyon locality. Petrographic, outcrop and subsurface studies demonstrate the viability of both the Canyon Springs Sandstone and Hulett Sandstone members as superior hydrocarbon reservoirs in both stratigraphic and structural traps. Examples of fields with hydrocarbon production from the Canyon Springs in paleovalleys include Lance Creek field (56 MMBO produced) and the more recently discovered Red Bird field (300 MBO produced), both in Niobrara County, Wyoming. At Red Bird field the primary exploration target was the Pennsylvanian "Leo sands" of the Minnelusa Formation, and

  20. Improved marine reservoir age estimation and palaeoclimate synchronisation of the early Holocene Levantine/NW-Arabian region based on identification of the S1 tephra in Dead Sea and Tayma palaeolake sediments

    NASA Astrophysics Data System (ADS)

    Neugebauer, Ina; Wulf, Sabine; Schwab, Markus J.; Serb, Johanna; Plessen, Birgit; Appelt, Oona; Brauer, Achim

    2017-04-01

    Due to a lack of tephras identified in marine and terrestrial palaeoclimate records from the Levantine-Arabian area, this region is still not sufficiently connected to the eastern Mediterranean tephrostratigraphical lattice. Here we report on the first finding of cryptotephra in the Holocene lacustrine sediment records of the Dead Sea and the Tayma palaeolake (NW Arabian Peninsula). The major elemental chemistry of the rhyolitic glass shards proves this tephra identical to the distal 'S1 tephra' identified in the Yammoûneh palaeolake, Lebanon (Develle et al, 2009), in a marine sediment record from the SE Levantine basin (Hamann et al., 2010) and in the Sodmein Cave archaeological site in Egypt (Barton et al., 2015). The 'S1 tephra', most likely corresponding to the early Holocene 'Dikkartın' dome eruption of the Erciyes Daǧ volcano in central Anatolia, Turkey, has been dated in the marine record at 8830 ± 140 cal yr BP. We present new age estimates of the 'S1 tephra' based on radiocarbon dating of terrestrial plant remains (Migowski et al., 2004) and pollen concentrates (Dinies et al., 2015), which reveal modelled ages of 8939 ± 83 cal yr BP in the Dead Sea sediments and 9041 ± 254 cal yr BP in Tayma. This allows the estimation of an early Holocene marine reservoir age of ca. 320 years in the SE Levantine Sea. The timing of the volcanic eruption during the early Holocene humid period, which led to the formation of sapropel S1 in the Mediterranean Sea, and the identification of the 'S1 tephra' more than 1200 km to the south are crucial for the synchronisation of marine and terrestrial palaeoclimate records in the eastern Mediterranean region. References: Barton et al., 2015. The role of cryptotephra in refining the chronology of Late Pleistocene human evolution and cultural change in North Africa. Quaternary Sci. Rev. 118, 151-169. Develle et al., 2009. Early Holocene volcanic ash fallout in the Yammoûneh lacustrine basin (Lebanon): Tephrochronological

  1. Effect of Age at Antiretroviral Therapy Initiation on Catch-Up Growth within the First 24 Months among HIV-Infected Children in the IeDEA West African Pediatric Cohort

    PubMed Central

    Jesson, Julie; Koumakpaï, Sikiratou; Diagne, Ndeye R.; Amorissani-Folquet, Madeleine; Kouéta, Fla; Aka, Addi; Lawson-Evi, Koko; Dicko, Fatoumata; Kouakou, Kouadio; Pety, Touré; Renner, Lorna; Eboua, Tanoh; Coffie, Patrick A.; Desmonde, Sophie; Leroy, Valériane

    2015-01-01

    Background We described malnutrition and the effect of age at antiretroviral therapy (ART) initiation on catch-up growth over 24 months among HIV-infected children enrolled in the IeDEA West African paediatric cohort (pWADA). Methods Malnutrition was defined at ART initiation (baseline) by a Z-score <-2 SD, according to three anthropometric indicators: Weight-for-age (WAZ) for underweight, Height-for-age (HAZ) for stunting, and Weight-for-Height/BMI-for-age (WHZ/BAZ) for wasting. Kaplan-Meier estimates for catch-up growth (Z-score ≥-2 SD) on ART, adjusted for gender, immunodeficiency and malnutrition at ART initiation, ART regimen, time period and country, were compared by age at ART initiation. Cox proportional hazards regression models determined predictors of catch-up growth on ART over 24 months. Results Between 2001 and 2012, 2004 HIV-infected children < 10 years of age were included. At ART initiation, 51% were underweight, 48% were stunted and 33% were wasted. The 24-month adjusted estimates for catch-up growth were 69% (95% confidence interval [CI]: 57;80), 61% (95%CI: 47;70), and 90% (95%CI: 76;95) for WAZ, HAZ, and WHZ/BAZ, respectively. Adjusted catch-up growth was more likely for children <5 years of age at ART initiation compared to children ≥5 years for WAZ, HAZ (P<0.001), and for WHZ/BAZ (P = 0.026). Conclusions Malnutrition among these children is an additional burden that has to be urgently managed. Despite a significant growth improvement after 24 months on ART, especially in children <5 years, a substantial proportion of children still never achieved catch-up growth. Nutritional care should be part of the global healthcare of HIV-infected children in sub-Saharan Africa. PMID:25955835

  2. Effect of Age at Antiretroviral Therapy Initiation on Catch-up Growth Within the First 24 Months Among HIV-infected Children in the IeDEA West African Pediatric Cohort.

    PubMed

    Jesson, Julie; Koumakpaï, Sikiratou; Diagne, Ndeye R; Amorissani-Folquet, Madeleine; Kouéta, Fla; Aka, Addi; Lawson-Evi, Koko; Dicko, Fatoumata; Kouakou, Kouadio; Pety, Touré; Renner, Lorna; Eboua, Tanoh; Coffie, Patrick A; Desmonde, Sophie; Leroy, Valériane

    2015-07-01

    We described malnutrition and the effect of age at antiretroviral therapy (ART) initiation on catch-up growth over 24 months among HIV-infected children enrolled in the International epidemiologic Databases to Evaluate Aids West African paediatric cohort. Malnutrition was defined at ART initiation (baseline) by a Z score <-2 standard deviations, according to 3 anthropometric indicators: weight-for-age (WAZ) for underweight, height-for-age (HAZ) for stunting and weight-for-height/BMI-for-age (WHZ/BAZ) for wasting. Kaplan-Meier estimates for catch-up growth (Z score ≥-2 standard deviations) on ART, adjusted for gender, immunodeficiency and malnutrition at ART initiation, ART regimen, time period and country, were compared by age at ART initiation. Cox proportional hazards regression models determined predictors of catch-up growth on ART over 24 months. Between 2001 and 2012, 2004 HIV-infected children <10 years of age were included. At ART initiation, 51% were underweight, 48% were stunted and 33% were wasted. The 24-month adjusted estimates for catch-up growth were 69% [95% confidence interval (CI): 57-80], 61% (95% CI: 47-70) and 90% (95% CI: 76-95) for WAZ, HAZ and WHZ/BAZ, respectively. Adjusted catch-up growth was more likely for children <5 years of age at ART initiation compared with children ≥5 years for WAZ, HAZ (P < 0.001) and WHZ/BAZ (P = 0.026). Malnutrition among these children is an additional burden that has to be urgently managed. Despite a significant growth improvement after 24 months on ART, especially in children <5 years, a substantial proportion of children still never achieved catch-up growth. Nutritional care should be part of the global healthcare of HIV-infected children in sub-Saharan Africa.

  3. Optoelectronic Reservoir Computing

    PubMed Central

    Paquot, Y.; Duport, F.; Smerieri, A.; Dambre, J.; Schrauwen, B.; Haelterman, M.; Massar, S.

    2012-01-01

    Reservoir computing is a recently introduced, highly efficient bio-inspired approach for processing time dependent data. The basic scheme of reservoir computing consists of a non linear recurrent dynamical system coupled to a single input layer and a single output layer. Within these constraints many implementations are possible. Here we report an optoelectronic implementation of reservoir computing based on a recently proposed architecture consisting of a single non linear node and a delay line. Our implementation is sufficiently fast for real time information processing. We illustrate its performance on tasks of practical importance such as nonlinear channel equalization and speech recognition, and obtain results comparable to state of the art digital implementations. PMID:22371825

  4. Conference on Dynamics of Cholinergic Function: Acetylcholine in Health, Disease and Aging Held at Oglebay Park, West Virginia on 31 October-4 November 1983.

    DTIC Science & Technology

    1984-04-01

    altering behavioral function. Con- ceivably lecithin, or a combination of Ch and some other agents (e.g. piracetam ?) might have a more definitive effect on...of experi- mental and clinical situations, of which piracetam is the prototype, have been named nootropic drugs (Giurgea C. Actualit~s Pharmacol. 25...115, 1972), The observations that piracetam induces a small decrease - in hippocampal ACh in aged rats (Bartus, R.T. et al., Neurobiol. Aging 2, 105

  5. Predictive Factors of Regular Physical Activity among Middle-Aged Women in the West of Iran, Hamadan: Application of PRECEDE Model.

    PubMed

    Emdadi, Shohreh; Hazavehie, Seyed Mohammad Mehdi; Soltanian, Alireza; Bashirian, Saeed; Heidari Moghadam, Rashid

    2015-01-01

    Regular physical activity is important for midlife women. Models and theories help better understanding this behavior among middle-aged women and better planning for change behavior in target group. This study aimed to investigate predictive factors of regular physical activity among middle-aged women based on PRECEDE model as a theoretical framework. This descriptive-analytical study was performed on 866 middle-aged women of Hamadan City western Iran, recruited with a proportional stratified sampling method in 2015. The participants completed a self-administered questionnaire including questions on demographic characteristics and PRECEDE model constructs and IPAQ questionnaire. Data were then analyzed by SPSS-16 and AMOS-16 using the Pearson correlation test and the pathway analysis method. Overall, 57% of middle-aged women were inactive (light level) or not sufficiently active. With SEM (Structural Equation Modeling) analysis, knowledge b=0.84, P<0.001, attitude b=0.799, P<0.001, self-efficacy b=0.633, P<0.001 as predisposing factor and social support as reinforcing factor b=0.2, P<0.001 were the most important predictors for physical activity among middle-aged women in Hamadan. The framework of the PRECEDE model is useful in understanding regular physical activity among middle-aged women. Furthermore, results showed the importance of predisposing and reinforcing factors when planning educational interventions.

  6. Reviving Abandoned Reservoirs with High-Pressure Air Injection: Application in a Fractured and Karsted Dolomite Reservoir

    SciTech Connect

    Robert Loucks; Stephen C. Ruppel; Dembla Dhiraj; Julia Gale; Jon Holder; Jeff Kane; Jon Olson; John A. Jackson; Katherine G. Jackson

    2006-09-30

    Despite declining production rates, existing reservoirs in the United States contain vast volumes of remaining oil that is not being effectively recovered. This oil resource constitutes a huge target for the development and application of modern, cost-effective technologies for producing oil. Chief among the barriers to the recovery of this oil are the high costs of designing and implementing conventional advanced recovery technologies in these mature, in many cases pressure-depleted, reservoirs. An additional, increasingly significant barrier is the lack of vital technical expertise necessary for the application of these technologies. This lack of expertise is especially notable among the small operators and independents that operate many of these mature, yet oil-rich, reservoirs. We addressed these barriers to more effective oil recovery by developing, testing, applying, and documenting an innovative technology that can be used by even the smallest operator to significantly increase the flow of oil from mature U.S. reservoirs. The Bureau of Economic Geology and Goldrus Producing Company assembled a multidisciplinary team of geoscientists and engineers to evaluate the applicability of high-pressure air injection (HPAI) in revitalizing a nearly abandoned carbonate reservoir in the Permian Basin of West Texas. The Permian Basin, the largest oil-bearing basin in North America, contains more than 70 billion barrels of remaining oil in place and is an ideal venue to validate this technology. We have demonstrated the potential of HPAI for oil-recovery improvement in preliminary laboratory tests and a reservoir pilot project. To more completely test the technology, this project emphasized detailed characterization of reservoir properties, which were integrated to access the effectiveness and economics of HPAI. The characterization phase of the project utilized geoscientists and petroleum engineers from the Bureau of Economic Geology and the Department of Petroleum

  7. Manicouagin Reservoir of Canada

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Recorded by the Space Shuttle Atlantis STS-110 mission, this is a photograph of the ice- covered Manicouagin Reservoir located in the Canadian Shield of Quebec Province in Eastern Canada, partially obscured by low clouds. This reservoir marks the site of an impact crater, 60 miles (100 kilometers) wide, which according to geologists was formed 212 million years ago when a meteorite crashed into this area. Over millions of years, the crater has been worn down by glaciers and other erosional processes. The Space Shuttle Orbiter Atlantis, STS-110 mission, was launched April 8, 2002 and returned to Earth April 19, 2002.

  8. Greenhouse Gas Emissions from Reservoir Water Surfaces: A ...

    EPA Pesticide Factsheets

    Collectively, reservoirs are an important anthropogenic source of greenhouse gases (GHGs) to the atmosphere. Attempts to model reservoir GHG fluxes, however, have been limited by inconsistencies in methodological approaches and data availability. An increase in the number of published reservoir GHG flux estimates during the last 15 years warrants a comprehensive analysis of the magnitude and potential controls on these fluxes. Here we synthesize worldwide reservoir CH4, CO2, and N2O emission data and estimate that GHG emissions from reservoirs account for 80.2 Tmol CO2 equivalents yr-1, thus constituting approximately 5% of anthropogenic radiative forcing. The majority (93%) of these emissions are from CH4, and mainly in the form of bubbles. While age and latitude have historically been linked to reservoir GHG emissions, we found that factors related to reservoir nutrient status and rainfall were better predictors. In particular, nutrient-rich eutrophic reservoirs were found to have an order of magnitude higher per-area CH4 fluxes, on average, than their nutrient-poor oligotrophic counterparts. Therefore, management measures to reduce reservoir eutrophication may result in an important co-benefit, the reduction of GHG emissions to the atmosphere. Greenhouse gas emissions (GHG)

  9. 40. VIEW, LOOKING WEST, OF TOP OF FLUME NEAR FOREBAY, ...

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

    40. VIEW, LOOKING WEST, OF TOP OF FLUME NEAR FOREBAY, SHOWING LUMBER SHED, TWO TRACKS, CRANEWAY SHED IN BACKGROUND, RESERVOIR TO LEFT, RIGHT TO YARDS AND FACILITIES, AND OVERFLOW SPILLWAY ON LOWER RIGHT - Electron Hydroelectric Project, Along Puyallup River, Electron, Pierce County, WA

  10. 8. VIEW LOOKING NORTH OF WEST BOILER ROOM LUDOWICI TILE ...

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

    8. VIEW LOOKING NORTH OF WEST BOILER ROOM LUDOWICI TILE ROOF. TWO 600,00 GALLON RESERVOIRS FOR BOILER FEED WATER ARE ON THE LEFT CENTER OF THE PHOTOGRAPH. - New York, New Haven & Hartford Railroad, Cos Cob Power Plant, Sound Shore Drive, Greenwich, Fairfield County, CT

  11. 5. Aerial view west, Adams Dam Road bottom center, State ...

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

    5. Aerial view west, Adams Dam Road bottom center, State Route 100 center, duck pond and reservoir center, State Route 100 center right, State Route 92 below center right, Brandywine Creek State Park center bottom. - Winterthur Farms, Intersection State Routes 92 & 100, Intersection State Routes 92 & 100, Winterthur, New Castle County, DE

  12. Sands of West Gondwana: An archive of secular magmatism and plate interactions — A case study from the Cambro-Ordovician section of the Tassili Ouan Ahaggar (Algerian Sahara) using U-Pb-LA-ICP-MS detrital zircon ages

    NASA Astrophysics Data System (ADS)

    Linnemann, Ulf; Ouzegane, Khadidja; Drareni, Amar; Hofmann, Mandy; Becker, Sindy; Gärtner, Andreas; Sagawe, Anja

    2011-04-01

    Enormous masses of highly mature quartz sands were deposited in Western Gondwana during the Cambrian-Ordovician time, and provide a wide range of information concerning magmatic events through time, provenance, paleoclimate, and basin history. We present a provenance study based on 630 U-Pb (LA-ICP-MS) ages of detrital zircon from the latest Cambrian to Ordovician siliciclastic rocks of the Tassili Ouan Ahaggar basin situated in the Algerian Sahara. Most authors suggest local sources only for the sandstones. Instead, we demonstrate that the detritus is derived from different cratons and terranes which contributed to the deposition of a Cambrian-Ordovician overstep sequence covering western and northern Africa. Most zircon ages (61.0%) fall in the range of ~ 540 to 740 Ma and are interpreted to have been derived from Pan-African orogenic belts such as the Trans-Saharan Belt of NW Africa and previously from the Brazila belt of South America. Other potential sources for this zircon population are terranes of Cadomian affinity situated marginal to West Africa. The second-largest zircon population (20.2%) is 2.0 to 2.2 Ga, and is attributed to sources in the West African craton, such as the Birimian basement and the Eburnean orogenic belt, with possible partial input from the Amazonian craton. A zircon population of 7.1% yields Mesoproterozoic and early Paleoproterozoic ages in the range of ~ 1.3 to ~ 1.8 Ga and was probably derived from source rocks outside of the West African basement, the Tuareg shield and other adjoining areas. The Amazonian craton is a potential source region. A population of 6.7% of all zircon ages scatter from ~ 750 Ma to ~ 980 Ma and may reflect input from latest stages of the formation of Rodinia and its subsequent dispersal. A smaller population (3.2%) of zircon ages lie between ~ 2.3 and 2.65 Ga, and may be derived from late Paleoproterozoic to early Archaean rocks from the West African craton and possibly from Amazonia. Less than 1% of all

  13. Application of Reservoir Characterization and Advanced Technology to Improve Recovery and Economics in a Lower Quality Shallow Shelf San Andres Reservoir.

    SciTech Connect

    Taylor, A.R.; Hickman, T.S.; Justice, J.J.

    1997-07-30

    The Oxy West Welch Project is designed to demonstrate how the use of advanced technology can improve the economics of miscible CO{sub 2} injection projects in lower quality shallow shelf carbonate reservoirs. The research and development phase (Budget Period 1) primarily involved advance and reservoir characterization. The current demonstration phase (Budget Period 2) will implement the reservoir management plan for an optimum miscible CO{sub 2} flood design based on the reservoir characterization. Although Budget Period I officially ended 12/31/96, reservoir characterization and optimum flood design has continued into the first part of Budget Period 2. Specifically, the geologic model was enhanced by integration of the 3-D seismic interpretations. This resulted in improved history match by the simulator and more accurate predictions of flood performance on which to base the project design. The majority of the project design work has been completed, material specifications provided and bids solicited. Preparation of the demonstration area is well underway.

  14. Reservoir stability studies

    SciTech Connect

    Doherty, T.J.

    1981-07-01

    The objective of the reservoir stability studies project is to develop stability criteria for large underground reservoirs in salt domes, hard rock caverns, and porous rock structures for air storage in utility applications. Because reservoir stability was deemed crucial to commercialization of compressed air energy storage (CAES) systems this project has received major emphasis in the early phases of the overall CAES program. A long term plan, including state-of-the-art assessment, numerical model development and experimental studies culminating in field research, as necessary, was formulated. This plan, initiated in 1977, has been completed during FY-1981 to the stage of specific experimental studies and field research. Activities within this project during FY-1981 have included completion of site specific geotechnical design evaluations using methodologies developed to assess hard rock cavern stability, implementation of in-mine research to evaluate numerical and laboratory study conclusions on the response of domal salt, and preparation of integrated laboratory and field study facilities to assess developed predictive methods and determine in situ response of a porous media reservoir to air injection. The major activity in the project has been the field study component of the porous media studies. Accomplishments there have included completion of exploration, permitting and leasing, operation contractor selection and negotiation, and initiation of procurement and construction for an FY-1982 test initiation. A major program milestone, drilling of the injection withdrawal well for this test, was completed ahead of schedule.

  15. Applying reservoir characterization technology

    SciTech Connect

    Lake, L.W.

    1994-12-31

    While reservoir characterization is an old discipline, only within the last 10 years have engineers and scientists been able to make quantitative descriptions, due mostly to improvements in high-resolution computational power, sophisticated graphics, and geostatistics. This paper summarizes what has been learned during the past decade by using these technologies.

  16. Reinjection into geothermal reservoirs

    SciTech Connect

    Bodvarsson, G.S.; Stefansson, V.

    1987-08-01

    Reinjection of geothermal wastewater is practiced as a means of disposal and for reservoir pressure support. Various aspects of reinjection are discussed, both in terms of theoretical studies as well as specific field examples. The discussion focuses on the major effects of reinjection, including pressure maintenance and chemical and thermal effects. (ACR)

  17. Reservoir assessment of the Nubian sandstone reservoir in South Central Gulf of Suez, Egypt

    NASA Astrophysics Data System (ADS)

    El-Gendy, Nader; Barakat, Moataz; Abdallah, Hamed

    2017-05-01

    The Gulf of Suez is considered as one of the most important petroleum provinces in Egypt and contains the Saqqara and Edfu oil fields located in the South Central portion of the Gulf of Suez. The Nubian sandstone reservoir in the Gulf of Suez basin is well known for its great capability to store and produce large volumes of hydrocarbons. The Nubian sandstone overlies basement rocks throughout most of the Gulf of Suez region. It consists of a sequence of sandstones and shales of Paleozoic to Cretaceous age. The Nubian sandstone intersected in most wells has excellent reservoir characteristics. Its porosity is controlled by sedimentation style and diagenesis. The cementation materials are mainly kaolinite and quartz overgrowths. The permeability of the Nubian sandstone is mainly controlled by grain size, sorting, porosity and clay content especially kaolinite and decreases with increase of kaolinite. The permeability of the Nubian Sandstone is evaluated using the Nuclear Magnetic Resonance (NMR technology) and formation pressure data in addition to the conventional logs and the results were calibrated using core data. In this work, the Nubian sandstone was investigated and evaluated using complete suites of conventional and advanced logging techniques to understand its reservoir characteristics which have impact on economics of oil recovery. The Nubian reservoir has a complicated wettability nature which affects the petrophysical evaluation and reservoir productivity. So, understanding the reservoir wettability is very important for managing well performance, productivity and oil recovery.

  18. Integration of Remotely-Sensed Geobotanical and Structural Methods for Hydrocarbon Exploration in West-Central West Virginia

    SciTech Connect

    1997-01-26

    This report covers the first of the two years covered in the DOE grant to investigate structural and geobotanical features of hydrocarbon reservoirs in western West Virginia. The reader is referred to the three previous Quarterly reports for greater detail on tasks originally described in those reports. The progress of the project will be discussed with reference to the tasks identified for the project.

  19. West Nile virus ecology in a tropical ecosystem in Guatemala.

    PubMed

    Morales-Betoulle, Maria E; Komar, Nicholas; Panella, Nicholas A; Alvarez, Danilo; López, María R; Betoulle, Jean-Luc; Sosa, Silvia M; Müller, María L; Kilpatrick, A Marm; Lanciotti, Robert S; Johnson, Barbara W; Powers, Ann M; Cordón-Rosales, Celia

    2013-01-01

    West Nile virus ecology has yet to be rigorously investigated in the Caribbean Basin. We identified a transmission focus in Puerto Barrios, Guatemala, and established systematic monitoring of avian abundance and infection, seroconversions in domestic poultry, and viral infections in mosquitoes. West Nile virus transmission was detected annually between May and October from 2005 to 2008. High temperature and low rainfall enhanced the probability of chicken seroconversions, which occurred in both urban and rural sites. West Nile virus was isolated from Culex quinquefasciatus and to a lesser extent, from Culex mollis/Culex inflictus, but not from the most abundant Culex mosquito, Culex nigripalpus. A calculation that combined avian abundance, seroprevalence, and vertebrate reservoir competence suggested that great-tailed grackle (Quiscalus mexicanus) is the major amplifying host in this ecosystem. West Nile virus transmission reached moderate levels in sentinel chickens during 2007, but less than that observed during outbreaks of human disease attributed to West Nile virus in the United States.

  20. REVIVING ABANDONED RESERVOIRS WITH HIGH-PRESSURE AIR INJECTION: APPLICATION IN A FRACTURED AND KARSTED DOLOMITE RESERVOIR

    SciTech Connect

    Robert Loucks; Steve Ruppel; Julia Gale; Jon Holder; Jon Olsen; Deanna Combs; Dhiraj Dembla; Leonel Gomez

    2003-06-01

    The Bureau of Economic Geology and Goldrus Producing Company have assembled a multidisciplinary team of geoscientists and engineers to evaluate the applicability of high-pressure air injection (HPAI) in revitalizing a nearly abandoned carbonate reservoir in the Permian Basin of West Texas. The characterization phase of the project is utilizing geoscientists and petroleum engineers from the bureau of Economic Geology and the Department of Petroleum Engineering (both at The University of Texas at Austin) to define the controls on fluid flow in the reservoir as a basis for developing a reservoir model. This model will be used to define a field deployment plant that Goldrus, a small independent oil company, will implement by drilling both vertical and horizontal wells during the demonstration phase of the project. Additional reservoir data are being gathered during the demonstration phase to improve the accuracy of the reservoir model. The results of the demonstration are being closely monitored to provide a basis for improving the design of the HPAI field deployment plan. The results of the reservoir characterization field demonstration and monitoring program will be documented and widely disseminated to facilitate adoption of this technology by oil operators in the Permian Basin and elsewhere in the US.

  1. Uneven-aged silviculture and management in the eastern United States: Proceedings of an In-Service Workshop; Morgantown, West Virginia; July 15-17, 1975

    Treesearch

    Warren T. Doolittle; A. P. Mustain; Carter B. Gibbs; David. A. Marquis; Barton M. Blum; Carl H. Tubbs; W. B. Leak; S. F. Gingrich; H. Clay Smith; Paul S. DeBald; LaMont G. Engle; Robert E. Phares

    1975-01-01

    The workshop, summarized in this Proceedings, represented a joint effort by personnel from Research, National Forest System, and State and Private Forestry, to review the state-of-the-art knowledge about the applicability of uneven-aged silviculture and management in the eastern United States. One major objective of this review was to develop a much better mutual...

  2. Annual Technical Progress Report - West Hackberry Tertiary Project

    SciTech Connect

    Allen Fornea; Bruce Cerveny; Travis H. Gillham

    1997-09-30

    The West Hackberry Tertiary Project is a field test of the concept that air injection can be combined with the Double Displacement Process to produce a tertiary recovery process that is both low cost and economic at current oil prices. The Double Displacement Process is the gas displacement of a water invaded oil column for the purpose of recovering tertiary oil by gravity drainage. In reservoirs with pronounced bed dip such as those found in West Hackberry and other Gulf Coast salt dome fields, reservoir performance has shown that gravity drainage recoveries average 80% to 90% of the original oil in place while waterdrive recoveries average 50% to 60% of the original oil in place. The target for tertiary oil recovery in the Double Displacement Process is the incremental oil between the 50% to 60% waterdrive recoveries and the 80% to 90% gravity drainage recoveries. Air injection on the west flank began in November of 1994. Although west flank air injection has increased reservoir pressure by 500 pounds per square inch (psi), production response has not yet occurred. The gas cap on the west flank has not expanded sufficiently to push the oil rim down to the nearest downstructure well.

  3. Dynamic-reservoir lubricating device

    NASA Technical Reports Server (NTRS)

    Ficken, W. H.; Schulien, H. E.

    1968-01-01

    Dynamic-reservoir lubricating device supplies controlled amounts of lubricating oil to ball bearings during operation of the bearings. The dynamic reservoir lubricating device includes a rotating reservoir nut, a hollow cylinder filled with lubricating oil, flow restrictors and a ball bearing retainer.

  4. Structural style of the Cuyo-Bolsones basin complex of west-central Argentina

    SciTech Connect

    Gollop, I.G. )

    1991-03-01

    The Cuyo-Bolsones basin complex is part of a mosaic of basinal features that lie in the eastern Andean foreland. Sedimentary section ranges from Ordovician to Tertiary in age with the main petroleum source and reservoir potential in Carboniferous to Triassic clastics. Thick conglomerate units and widespread unconformities of both Permo-Carboniferous and Triassic age as well as localized volcanics indicate several periods of violent tectonic activity during late Paleozoic to early Mesozoic times. Triassic and older sediments are affected by normal faulting which in basins directly south extends up into the Lower Cretaceous. In the Cuyo-Bolsones basinal area, however this ancient tensional regime is entirely overprinted by relatively recent thrusting. This thrusting is late Tertiary in age, generally from east to west with very substantial relief. These thrust sheets are cut in places by later northeast-southwest strike-slip fault zones producing some localized flower structures. Nearly all the oil discovered in the Cuyo basin is produced from Triassic clastic reservoirs in compressional anticlines related to this thrusting. The major thrusts are well defined seismically, and seismic interpretations fit easily on balanced sections.

  5. Vertical stacking of reservoirs in Silurian carbonates of Appalachian basin

    SciTech Connect

    Smosna, R.; Conrad, J.M.; Maxwell, T.C.

    1988-08-01

    The distribution of modern reefs and oolites is controlled to a large degree by sea-floor topography. Likewise, paleotopographic highs in the Silurian Lockport Dolomite and underlying Keefer Sandstone provided optimum sites for the deposition of boundstone and grainstone reservoir facies. The Keefer Sandstone in western West Virginia was deposited as a series of subtidal sand waves with a relief of a few meters. During initial Lockport sedimentation, the turbulence, water chemistry, and light intensity were most favorable in shallow water over the Keefer sand waves, encouraging growth of coral-stromatoporoid patch reefs. Skeletal banks in the upper Lockport of eastern Kentucky also were established over topographic highs of earlier Lockport mounds. In a similar fashion, the upper Lockport of West Virginia was deposited as oolitic shoals that formed atop exposed mud mounds in the middle member. A slight rise of sea level created the agitated subtidal environment above the now-submerged mud mounds, and oolite bars developed. The reef, skeletal-bank, and oolite facies of the Lockport, and the Keefer Sandstone, are all petroleum reservoirs. Carbonate reservoirs can be identified in the subsurface by thicks on isopach maps, by their clean gamma-ray signature, and by a relatively high log porosity. Based on these criteria, seven potential fairways have been mapped in Kentucky. Because the distribution of buildups was greatly influenced by that of their predecessors, five of the fairways contain vertically stacked reservoir facies. These are particularly attractive because they can be drilled as multistory targets.

  6. Application of high-resolution depositional modeling to reservoir characterisation

    SciTech Connect

    Keyu, L.; Paterson, L.

    1995-08-01

    As hydrocarbon producing basins and fields become more intensely developed, conventional stratigraphic analysis methods can sometimes no longer meet the resolution required by petroleum geologists and engineers. High-resolution depositional modeling provides a quantitative alternative to the conventional approach of sequence stratigraphic analysis. A computer program, SEDPAK, which was designed primarily according to the basic premise of the sequence stratigraphic concept, was here used to conduct high-resolution simulations for two sedimentary sequences. One is a Pliocene to Recent shelf margin sediment sequence of the offshore Sydney Basin continental shelf, Australia; the other is the Early Cretaceous (Aptian) Windalia Sand reservoir of the Barrow Island Field, North West Shelf, Australia. In both instances, the simulations have well mimicked the variations of the sedimentary facies temporally and spatially in fine detail with each time step representing 10 ka and a vertical resolution of one meter. The reservoir heterogeneities and the observed cyclicity in the Windalia Sand were particularly well documented by the SEDPAK simulation using a locally derived sealevel curve. The simulation result suggested that high-frequency sealevel variations ?associated with Milankovitch cyclicity were probably the primary cause that controlled the reservoir heterogeneities of the Windalia Sand. This finding provides a working model for the Cretaceous coeval reservoirs in the North West Shelf, Australia.

  7. Geology, tephrochronology, radiometric ages, and cross sections of the Mark West Springs 7.5 degree quadrangle, Sonoma and Napa counties, California

    USGS Publications Warehouse

    McLaughlin, R.J.; Sarna-Wojicki, A. M.; Fleck, R.J.; Wright, W.H.; Levin, V.R.G.; Valin, Z.C.

    2004-01-01

    This geologic map database and cross sections presents new geologic mapping by the authors in addition to new radiometric ages and tephrochronology of volcanic rock units. The map database depicts the general distribution of bedrock and surficial deposits in the mapped area and provides a context for interpreting the evolution of active faults in the region. Together with the accompanying PDF file (SIM2858-pamphlet.pdf), it provides current information on the geologic structure and stratigraphy of the area covered. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The scale of the source maps limits the spatial resolution (scale) of the database to 1:24,000 or smaller.

  8. Geochemistry and the Sm-Nd model age of sedimentary rocks from the lower horizon of the cover in the northeastern part of the West Siberian Platform

    NASA Astrophysics Data System (ADS)

    Ivanov, K. S.; Ronkin, Yu. L.; Erokhin, Yu. V.; Pogromskaya, O. E.

    2017-07-01

    The pre-Jurassic basement and lower (Jurassic) horizons of the sedimentary cover in Hole Borovaya 6 were studied. Analysis of rare and rare-earth elements shows that Jurassic sedimentary rocks were most likely formed at the expense of erosion and mixing of heterogeneous materials, namely acid sources of the Siberian Platform and Triassic riftogenic basaltoids. The variations of 147Sm/144Nd (0.1076-0.1250) and 143Nd/144Nd (0.512202-0.512437), as well as the Sm-Nd model ages of Jurassic sediments (1146-1362 Ma), provide certain evidence for participation of the Mesoproterozoic substrate in the formation of the rocks studied. The Sm-Nd model age of pre-Jurassic rocks (1281 Ma) is Mesoproterozoic as well. The Precambrian crystalline basement of the Siberian Platform is a likely source of these sedimentary rocks.

  9. Surrogate Reservoir Model

    NASA Astrophysics Data System (ADS)

    Mohaghegh, Shahab

    2010-05-01

    Surrogate Reservoir Model (SRM) is new solution for fast track, comprehensive reservoir analysis (solving both direct and inverse problems) using existing reservoir simulation models. SRM is defined as a replica of the full field reservoir simulation model that runs and provides accurate results in real-time (one simulation run takes only a fraction of a second). SRM mimics the capabilities of a full field model with high accuracy. Reservoir simulation is the industry standard for reservoir management. It is used in all phases of field development in the oil and gas industry. The routine of simulation studies calls for integration of static and dynamic measurements into the reservoir model. Full field reservoir simulation models have become the major source of information for analysis, prediction and decision making. Large prolific fields usually go through several versions (updates) of their model. Each new version usually is a major improvement over the previous version. The updated model includes the latest available information incorporated along with adjustments that usually are the result of single-well or multi-well history matching. As the number of reservoir layers (thickness of the formations) increases, the number of cells representing the model approaches several millions. As the reservoir models grow in size, so does the time that is required for each run. Schemes such as grid computing and parallel processing helps to a certain degree but do not provide the required speed for tasks such as: field development strategies using comprehensive reservoir analysis, solving the inverse problem for injection/production optimization, quantifying uncertainties associated with the geological model and real-time optimization and decision making. These types of analyses require hundreds or thousands of runs. Furthermore, with the new push for smart fields in the oil/gas industry that is a natural growth of smart completion and smart wells, the need for real time

  10. sup 40 Ar/ sup 39 Ar polyorogenic mineral age record within the southern Mauritanide orogen (M'Bout-Bakel region) West Africa

    SciTech Connect

    Dallmeyer, R.D. ); Lecorche, J.P. )

    1990-12-01

    The southern Mauritanide orogen exposed between M'Bout and Bakel is characterized by several internally imbricated, polydeformed, and variably metamorphosed infrastructural allochthons. {sup 40}Ar/{sup 39}Ar incremental-release ages recorded by hornblende within undeformed granodiorite of the Guidimakha Complex suggest post-magmatic cooling through appropriate argon closure temperatures at approx 670 Ma. {sup 40}Ar/{sup 39}Ar ages recorded by muscovite within lithologic elements of both the Guidimakha Complex and the Diala-Bouanze Series suggest initial regional metamorphism (associated with Pan-African I orogenesis) was following by cooling through muscovite argon closure temperatures between approx 600 and 620 Ma. Slight rejuvenation of muscovite argon systems occurred locally between approx 325 and 350 Ma. Muscovite and whole-rock slate/phyllite argon systems within metavolcanic and metavolcaniclastic components of the infrastructural calc-alkaline igneous complex (easternmost sectors of the M'Bout Series) record {sup 40}Ar/{sup 39}Ar plateau age of approx 300 to 320 Ma. Muscovite and whole-rock slate/phyllite argon systems within westernmost portions of the study area (western portions of the M'Bout Series) record {sup 40}Ar/{sup 39}Ar plateau ages of approx 267 to 312 Ma. All foreland units within the M'Bout-Bakel area were affected by post-Emsian folding. Effects of this tectonic activity are widespread throughout the parautochthon and western metamorphic sequences. These effects include emplacement of suprastructural ( ) allochthons and local reactivation of older thrust faults within infrastructural units.

  11. Missed opportunities of inclusion in a cohort of HIV-infected children to initiate antiretroviral treatment before the age of two in West Africa, 2011 to 2013

    PubMed Central

    Dahourou, Désiré L; Amorissani-Folquet, Madeleine; Coulibaly, Malik; Avit-Edi, Divine; Meda, Nicolas; Timite-Konan, Marguerite; Arendt, Vic; Ye, Diarra; Amani-Bosse, Clarisse; Salamon, Roger; Lepage, Philippe; Leroy, Valériane

    2016-01-01

    Introduction The World Health Organization (WHO) 2010 guidelines recommended to treat all HIV-infected children less than two years of age. We described the inclusion process and its correlates of HIV-infected children initiated on early antiretroviral therapy (EART) at less than two years of age in Abidjan, Côte d'Ivoire, and Ouagadougou, Burkina Faso. Methods All children with HIV-1 infection confirmed with a DNA PCR test of a blood sample, aged less than two years, living at a distance less than two hours from the centres and whose parents (or mother if she was the only legal guardian or the legal caregiver if parents were not alive) agreed to participate in the MONOD ANRS 12206 project were included in a cohort to receive EART based on lopinavir/r. We used logistic regression to identify correlates of inclusion. Results Among the 217 children screened and referred to the MONOD centres, 161 (74%) were included and initiated on EART. The main reasons of non-inclusion were fear of father's refusal (48%), mortality (24%), false-positive HIV infection test (16%) and other ineligibility reasons (12%). Having previously disclosed the child's and mother's HIV status to the father (adjusted odds ratio (aOR): 3.20; 95% confidence interval (95% CI): 1.55 to 6.69) and being older than 12 months (aOR: 2.05; 95% CI: 1.02 to 4.12) were correlates of EART initiation. At EART initiation, the median age was 13.5 months, 70% had reached WHO Stage 3/4 and 57% had a severe immune deficiency. Conclusions Fear of stigmatization by the father and early competing mortality were the major reasons for missed opportunities of EART initiation. There is an urgent need to involve fathers in the care of their HIV-exposed children and to promote early infant diagnosis to improve their future access to EART and survival. PMID:27015798

  12. Reservoirs in the United States

    USGS Publications Warehouse

    Thomas, N.O.; Harbeck, G. Earl

    1956-01-01

    Reservoir storage facilities in the United States play an important part in the national economy. Storage facilities have enabled the country to utilize to a much fuller extent one of the most valuable natural resources: water. During recent years the construction of reservoirs has continued at a high rate. This report shows the status of these facilities on January 1, 1954, and describes briefly some of the reasons for growth of reservoir facilities in the United States. Descriptive data are given for reservoirs having a capacity of 5, 000 acre-feet or more and for natural lakes having a usable capacity of 5,000 acre-feet or more. Included are reservoirs and lakes completed as of January 1, 1954, and reservoirs under construction on that date. The total number of such reservoirs and lakes is 1, 300. A descriptive list of reservoirs in the United States was first published by the United States Geological Survey in March 1948. That report, Geological Survey Circular 23, entitled Reservoirs in the United States, included reservoirs completed as of January 1, 1947. Since January 1, 1947, reservoirs representing a total usable capacity of 115,000,000 acre-feet, or an increase of 71 percent, have been constructed or are under construction. Data about these new reservoirs are presented herein, and the data shown for reservoirs constructed before 1947 have been corrected on the basis of the latest available survey to determine reservoir capacity. The total usable capacity of reservoirs and lakes included in this compilation amounts to 278, 120, 000 acre-feet, and the corresponding surface area totals 11, 046, 000 acres.

  13. 7. DETAIL VIEW OF WEST SIDE OF WEST BRIDGE ABUTMENT ...

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

    7. DETAIL VIEW OF WEST SIDE OF WEST BRIDGE ABUTMENT AND UNKNOWN STRUCTURE FROM BELOW, FACING NORTHWEST - West Branch Bridge, South Carolina Road S-569 spanning West Branch of Pacolet River, Pacolet, Spartanburg County, SC

  14. Cosmogenic exposure age evidence for rapid Laurentide deglaciation of the Katahdin area, west-central Maine, USA, 16 to 15 ka

    NASA Astrophysics Data System (ADS)

    Davis, P. Thompson; Bierman, Paul R.; Corbett, Lee B.; Finkel, Robert C.

    2015-05-01

    Katahdin, the highest peak in Maine and part of the second highest mountain range in New England, provides an opportunity to assess the timing and style of continental ice sheet surface lowering during deglaciation. We collected 14 samples from boulders on the adjacent Basin Ponds moraine, from bedrock and boulders on the upper part of the mountain, and from boulders in the surrounding area to estimate the age at which they were exposed by deglaciation of the Laurentide Ice Sheet. Measurements of in situ produced 10Be, which are consistent with measurements of 26Al, indicate that the Katahdin edifice became exposed from under ice by 15.3 ± 2.1 ka (n = 6), an age indistinguishable from the adjacent Basin Ponds moraine (16.1 ± 1.2 ka, n = 5). A boulder in the lowlands several km south of the moraine dates to 14.5 ± 0.8 ka, and a boulder deposited at Pineo Ridge, about 170 km SE of Katahdin, dates to 17.5 ± 1.1 ka. These data show that samples collected over an elevation range of 1.6 km and a distance of >170 km all have exposure ages that are indistinguishable within uncertainties. Together these data suggest that the Laurentide Ice Sheet surface dropped rapidly and the ice sheet margin retreated quickly across Maine between about 16 and 15 ka, perhaps influenced by calving of the marine-based ice sheet in the St. Lawrence Lowlands to the north and the Penobscot basin to the south.

  15. Quantification of Libby Reservoir Water Levels Needed to Maintain or Enhance Reservoir Fisheries, 1988-1996 Methods and Data Summary.

    SciTech Connect

    Dalbey, Steven Ray

    1998-03-01

    The Libby Reservoir study is part of the Northwest Power Planning Council's resident fish and wildlife program. The program was mandated by the Northwest Planning Act of 1980, and is responsible for mitigating for damages to fish and wildlife caused by hydroelectric development in the Columbia River Basin. The objective of Phase I of the project (1983 through 1987) was to maintain or enhance the Libby Reservoir fishery by quantifying seasonal water levels and developing ecologically sound operational guidelines. The objective of Phase II of the project (1988 through 1996) was to determine the biological effects of reservoir operations combined with biotic changes associated with an aging reservoir. This report summarizes the data collected from Libby Reservoir during 1988 through 1996.

  16. Potential methane reservoirs beneath Antarctica.

    PubMed

    Wadham, J L; Arndt, S; Tulaczyk, S; Stibal, M; Tranter, M; Telling, J; Lis, G P; Lawson, E; Ridgwell, A; Dubnick, A; Sharp, M J; Anesio, A M; Butler, C E H

    2012-08-30

    Once thought to be devoid of life, the ice-covered parts of Antarctica are now known to be a reservoir of metabolically active microbial cells and organic carbon. The potential for methanogenic archaea to support the degradation of organic carbon to methane beneath the ice, however, has not yet been evaluated. Large sedimentary basins containing marine sequences up to 14 kilometres thick and an estimated 21,000 petagrams (1 Pg equals 10(15) g) of organic carbon are buried beneath the Antarctic Ice Sheet. No data exist for rates of methanogenesis in sub-Antarctic marine sediments. Here we present experimental data from other subglacial environments that demonstrate the potential for overridden organic matter beneath glacial systems to produce methane. We also numerically simulate the accumulation of methane in Antarctic sedimentary basins using an established one-dimensional hydrate model and show that pressure/temperature conditions favour methane hydrate formation down to sediment depths of about 300 metres in West Antarctica and 700 metres in East Antarctica. Our results demonstrate the potential for methane hydrate accumulation in Antarctic sedimentary basins, where the total inventory depends on rates of organic carbon degradation and conditions at the ice-sheet bed. We calculate that the sub-Antarctic hydrate inventory could be of the same order of magnitude as that of recent estimates made for Arctic permafrost. Our findings suggest that the Antarctic Ice Sheet may be a neglected but important component of the global methane budget, with the potential to act as a positive feedback on climate warming during ice-sheet wastage.

  17. Status of Blue Ridge Reservoir

    SciTech Connect

    Not Available

    1990-09-01

    This is one in a series of reports prepared by the Tennessee Valley Authority (TVA) for those interested in the conditions of TVA reservoirs. This overview of Blue Ridge Reservoir summarizes reservoir and watershed characteristics, reservoir uses and use impairments, water quality and aquatic biological conditions, and activities of reservoir management agencies. This information was extracted from the most current reports and data available, as well as interview with water resource professionals in various federal, state, and local agencies. Blue Ridge Reservoir is a single-purpose hydropower generating project. When consistent with this primary objective, the reservoir is also operated to benefit secondary objectives including water quality, recreation, fish and aquatic habitat, development of shoreline, aesthetic quality, and other public and private uses that support overall regional economic growth and development. 8 refs., 1 fig.

  18. West Nile virus

    MedlinePlus

    ... believe West Nile virus is spread when a mosquito bites an infected bird and then bites a ... avoid getting West Nile virus infection after a mosquito bite. People in good health generally do not ...

  19. West Nile Virus and wildlife

    USGS Publications Warehouse

    Marra, P.P.; Griffing, S.; Caffrey, C.; Kilpatrick, A.M.; McLean, R.; Brand, C.; Saito, E.; Dupuis, A.P.; Kramer, Laura; Novak, R.

    2004-01-01

    West Nile virus (WNV) has spread rapidly across North America, resulting in human deaths and in the deaths of untold numbers of birds, mammals, and reptiles. The virus has reached Central America and the Caribbean and may spread to Hawaii and South America. Although tens of thousands of birds have died, and studies of some bird species show local declines, few regionwide declines can be attributed to WNV. Predicting future impacts of WNV on wildlife, and pinpointing what drives epidemics, will require substantial additional research into host susceptibility, reservoir competency, and linkages between climate, mosquitoes, and disease. Such work will entail a collaborative effort between scientists in governmental research groups, in surveillance and control programs, and in nongovernmental organizations. West Nile virus was not the first, and it will not be the last, exotic disease to be introduced to the New World. Its spread in North America highlights the need to strengthen animal monitoring programs and to integrate them with research on disease ecology.

  20. Interactive reservoir simulation

    SciTech Connect

    Regtien, J.M.M. Por, G.J.A.; Stiphout, M.T. van; Vlugt, F.F. van der

    1995-12-31

    Shell`s new Modular Reservoir Simulator (MoReS) has been equipped with a comprehensive and versatile user interface called FrontEnd. Apart from providing a user-friendly environment for interactive reservoir simulation, FrontEnd serves a software platform for other dynamic simulation and reservoir-engineering applications. It offers to all supported applications a common user interface, enables the re-use of code and reduces overall maintenance and support costs associated with the embedded applications. Because of its features, FrontEnd facilitates the transfer of research results in the form of operational software to end users. When coupled with MoReS, FrontEnd can be used for pre- and post-processing and interactive simulation. The pre-processing options allow data to be inputted by means of various OSF/Motif widgets containing a spreadsheet, text editors, dialogues and graphical input. The display of the input data as well as the post-processing of all simulation results is made possible by a variety of user-defined plot of tabular (e.g. timestep summary) and array (simulation grid) data. During a simulation user-defined plots can be displayed and edited, allowing a close inspection of the results as they are being calculated. FrontEnd has been equipped with a powerful input command language, which gives the batch user as much flexibility and control over the input as the interactive user.

  1. Hydrogeology of the West Branch Delaware River basin, Delaware County, New York

    USGS Publications Warehouse

    Reynolds, Richard J.

    2013-01-01

    In 2009, the U.S. Geological Survey, in cooperation with the New York State Department of Environmental Conservation, began a study of the hydrogeology of the West Branch Delaware River (Cannonsville Reservoir) watershed. There has been recent interest by energy companies in developing the natural gas reserves that are trapped within the Marcellus Shale, which is part of the Hamilton Group of Devonian age that underlies all the West Branch Delaware River Basin. Knowing the extent and thickness of stratified-drift (sand and gravel) aquifers within this basin can help State and Federal regulatory agencies evaluate any effects on these aquifers that gas-well drilling might produce. This report describes the hydrogeology of the 455-square-mile basin in the southwestern Catskill Mountain region of southeastern New York and includes a detailed surficial geologic map of the basin. Analysis of surficial geologic data indicates that the most widespread surficial geologic unit within the basin is till, which is present as deposits of ablation till in major stream valleys and as thick deposits of lodgment till that fill upland basins. Till and colluvium (remobilized till) cover about 89 percent of the West Branch Delaware River Basin, whereas stratified drift (outwash and ice-contact deposits) and alluvium account for 8.9 percent. The Cannonsville Reservoir occupies about 1.9 percent of the basin area. Large areas of outwash and ice-contact deposits occupy the West Branch Delaware River valley along its entire length. These deposits form a stratified-drift aquifer that ranges in thickness from 40 to 50 feet (ft) in the upper West Branch Delaware River valley, from 70 to 140 ft in the middle West Branch Delaware River valley, and from 60 to 70 ft in the lower West Branch Delaware River valley. The gas-bearing Marcellus Shale underlies the entire West Branch Delaware River Basin and ranges in thickness from 600 to 650 ft along the northern divide of the basin to 750 ft thick

  2. Potential Impacts of Leakage from Black Rock Reservoir on the Hanford Site Unconfined Aquifer: Initial Hypothetical Simulations of Flow and Contaminant Transport - Errata

    SciTech Connect

    Freedman, Vicky L.

    2007-04-30

    Errata for report documenting initial scoping calculations investigating the potential impacts on the Hanford unconfined aquifer resulting from leakage from the proposed Black Rock Reservoir to the west. These calculations were performed for the U.S. Bureau of Reclamation.

  3. America's Historic West.

    ERIC Educational Resources Information Center

    Beardsley, Donna A.

    Settlers who pushed west over the Great Divide to the shores of the Pacific Ocean found the American West to be an expanse of extreme differences in time, topography, and ways of life. This paper elaborates on several historic sites in the American West. The purpose of the paper is to introduce a series of places to the students and teachers of…

  4. Radiocarbon Content of Intermediate Waters off West Sumatra During the Last 45,000 Years

    NASA Astrophysics Data System (ADS)

    De Pol-Holz, R.; Mohtadi, M.; Southon, J. R.

    2014-12-01

    Radiocarbon content of intermediate waters originating from the Southern Ocean is held as a likely smoking gun of the events that triggered the atmospheric CO2 rise and its radiocarbon decline during the last glacial-interglacial transition. Late Glacial depleted radiocarbon water masses have been found at intermediate depths off the coast of Baja California, the Galapagos, the Arabian Sea, but not unequivocally elsewhere. Knowing the route of the old water is therefore central for the required mechanistic linkage of Southern Ocean processes and the atmospheric response. A common approach to search for the old water reservoir is the radiocarbon difference between planktonic and benthic foraminifera or 'apparent ventilation age'. Caveats of this approach are due to the fact that it relies strongly on the knowledge of the surface water reservoir age. In this study, we present a high-resolution radiocarbon difference between surface and intermediate depth waters off west Sumatra in the attempt to elucidate a possible route of the old water from its hypothetical source in the high latitudes near Antarctica on its way to the lower latitude sites where it has been observed. Samples come from core SO189-39KL (0°47'S, 99°55'E, 517 m), a 1350 cm hemipelagic sedimentary sequence that spans the last 45,000 years. Radiocarbon determinations were made at centennial time resolution on both planktonic and benthic species. Calibration of the planktonic radiocarbon as age control points allowed us to infer the Δ14C of the intermediate waters. Our results show that throughout the LGM and the entire deglaciation, radiocarbon content of intermediate depths in the area remained with an almost constant age difference with the contemporaneous atmosphere. Unless we have grossly underestimated the local planktonic reservoir age, our results discard this area as a probable route for the spreading of the old water along its way to northern latitudes. In light of recent evidence from the

  5. A postal survey of data in general practice on the prevalence of Acquired Brain Injury (ABI) in patients aged 18-65 in one county in the west of Ireland.

    PubMed

    Finnerty, Fionnuala; Glynn, Liam; Dineen, Brendan; Colfer, Finbarr; Macfarlane, Anne

    2009-05-19

    Very little is known about the prevalence of acquired brain injury (ABI) in Ireland. ABI prevalence has previously been obtained from Belgian general practitioners using a postal survey. We attempted to ascertain the prevalence of ABI in County Mayo through a postal survey of all general practitioners in the county.The specific objectives of this project were to:1. identify whether general practitioners are a. aware of patients with ABI aged 18-65 in their practices b. able to provide prevalence data on ABI in patients aged 18-65 c. able to provide data on age, gender and patient diagnosis 2. analyse prevalence of ABI from any available data from general practitioners. A pilot postal survey was performed initially in order to assess the feasibility of the study. It was established that general practitioners did have the necessary information required to complete the questionnaire. A main postal survey was then undertaken. A postal questionnaire was administered to all general practices in County Mayo in the west of Ireland (n = 59). The response rate was 32.2% (n = 19). General practitioners who replied on behalf of their practice could provide data on patient age, gender and diagnosis. In the nineteen practices, there were 57 patients with ABI. The age-specific prevalence of ABI in the area surveyed was estimated at 183.7 per 100,000. The mean patient population per practice was 2,833 (SD = 950). There were found to be significantly more patients with ABI in rural areas than urban areas (p = 0.006). There were also significant differences in the ages of patients in the different ABI categories. Patients whose ABI was of traumatic origin were significantly younger than those patients with ABI of haemorrhagic origin (p = 0.002). Although this is a small-scale study, we have ascertained that general practitioners do have data on patients with ABI. Also, some prevalence data now exist where none was available before. These can be used to form the basis of a more

  6. Changes in thermodynamic conditions of the Ahuachapan reservoir due to production and injection

    SciTech Connect

    Steingrimsson, B.; Bodvarsson, G.S. ); Cuellar, G.; Escobar, C. )

    1989-01-01

    Since large-scale exploitation of the Ahuachanpan reservoir began in 1975 with the commencement of the first 30 MW{sub e} unit, large changes in the reservoir thermodynamic condition have occurred. Drawdowns up to 15 bars have developed in the production field and significant temperature changes have been observed. In most cases temperatures have declined due to boiling in the reservoir stimulated by the pressure drawdown; cooling due to reinjection of spent geothermal fluids has also been observed. There are indications of a cold fluid recharge to the reservoir from the west and north. Increasing temperatures in the southeast corner of the wellfield show that significant recharge of hot fluids to the wellfield comes from the southeast; they also indicate that the recharge rate has increased with time as the pressure declines in the reservoir. 8 refs., 13 figs.

  7. Contribution of stable isotopes and age dating tools to the understanding of pesticide transfer into surface and ground-waters in Martinique (French West Indies)

    NASA Astrophysics Data System (ADS)

    Gourcy, Laurence; Arnaud, Luc; Baran, Nicole; Petelet-Giraud, Emmanuelle

    2013-04-01

    In Martinique, chlordecone, a synthetic chlorinated organic compound has mainly been used as an insecticide for banana farming up to 1993. The intrinsic characteristic of this contaminant makes it still quite abundant in soil, surface and groundwater. Since 2004 and the implementation of the Water Framework Directive the concentration of chlordecone in groundwater has been monitored regularly (two to four times / year) at different points of the island by the ODE (Office de l'Eau). Previous study (Gourcy et al. 2009, Arnaud et al. 2012) showed that variations of pesticides concentrations in groundwater are temporally strong and not always easy to correlate to climate, geological or hydrogeological context. The objective of the present study was to explore new investigation ways to identify, in a specific site and for high sampling frequency possible pathways of chlordecone into surface and ground-waters. A major sampling campaign was carried out in December 2011 including 12 surface and groundwater points located in Chalvet and Chez Lélène wells watersheds. Besides, monthly or weekly samples were taken at these two groundwater monitoring wells and the Falaise river up to August 2012. Major dissolved ions, δ18O, δ2H, chlordecone concentrations were determined for all samples. CFC-11, CFC-12, CFC-113 and SF6 analyses were performed for groundwater for apparent age estimation. Punctual or cumulative rainfalls were sampled at Chalvet (30 m NGM) and Aileron (800 m NGM) for stable isotopes determination. The isotope data are indicating a deuterium excess higher for surface water, groundwater and rainfall collected at high altitude vs. samples corresponding to lowest altitudes. This data can therefore be used to estimate the average altitude of recharge area of groundwater. This altitude of recharge, between 30 and 350m corresponds to the altitude of banana growing ; it is therefore in accordance with the presence of chlordecone in soils. This information is also

  8. West Hackberry Tertiary Project, Class I

    SciTech Connect

    Haley, Kenneth A.; Gillham, Travis H.; Yannimaras, Demetrios

    2002-03-04

    The West Hackberry Tertiary Project is a field test of the concept that air injection can generate tertiary oil recovery through the Double Displacement Process. The Double Displacement Process is the gas displacement of a water invaded oil column for the purpose of recovering tertiary oil through gravity drainage. The novel aspect of this project is the use of air as the injection fluid. In Gulf Coast oil reservoirs with pronounced bed dip, reservoir performance has shown that gravity drainage recoveries average 80% to 90% of the original oil in place while water drive recoveries average 50% to 60% of the original oil in place. The target for tertiary oil recovery with the Double Displacement Process is the incremental oil between the 50% to 60% water drive recoveries and the 80% to 90% gravity drainage recoveries.

  9. Improving the knowledge of pesticide and nitrate transfer processes using age-dating tools (CFC, SF6, 3H) in a volcanic island (Martinique, French West Indies).

    PubMed

    Gourcy, Laurence; Baran, Nicole; Vittecoq, Benoit

    2009-09-01

    Numerous successful examples of CFC and SF(6) groundwater dating applications were recently published. However the proposed CFC/SF(6) method needs various hydrodynamic parameters that are not always available. In order to predict groundwater-quality trends in areas where the hydrogeological context is poorly known, a dating method using tritium, CFC and SF(6) was successfully implemented in Martinique. Hydrogeological understanding is limited in this volcanic island where groundwater contamination by pesticides and nitrate has been recently proven in various areas. A negative correlation was observed between nitrate concentrations and groundwater ages while pesticide contamination showed a more complex schema. Consequently the presence of old groundwater clearly explained the absence or low pesticide and nitrate concentrations in some areas. However a possible degradation of the water quality is to be feared in the future. In view of the relatively long transfer times and the complexity of the remobilization processes of solutes, the expected effects of any modifications in the use of fertilizers, or of changes in pesticide-use legislation, would take a long time to become apparent.

  10. Clay cortex in epikarst forms as an indicator of age and morphogenesis-case studies from Lublin-Volhynia chalkland (East Poland, West Ukraine)

    NASA Astrophysics Data System (ADS)

    Dobrowolski, Radosław; Mroczek, Przemysław

    2015-10-01

    Clay cortex from the contact zone between the host rock (chalk) and infilling deposits were examined in paleokarst forms (pockets, pipes, and dolines of different age) from the Lublin-Volhynia chalk karst region. In light of the sedimentological and micromorphological analyses, it seems possible to work out a model as the basis for genetic and stratigraphic discussions. (1) Dolines with the Paleogene or Neogene mineral infills are characterized by (a) homogeneous, residual type of massive clay gradually passing into the chalk monolith, and at the same time (b) relatively thick weathered zone. (2) Pipes with glacigenic mineral infill from the Saalian Glacial are characterized by (a) sharp contact between host rock and clay, (b) narrow weathering zone of chalk, (c) diffuse nature of the contact zone between residual clay and mineral infill, and (d) contamination of clay by clastic material. (3) Pockets with glacigenic mineral infill and traces of the Weichselian periglacial transformation are characterized by (a) strong contamination of chalk by quartz grains, (b) diffuse transition between clay and infill: from clayey matrix with single quartz grains (at the contact with chalk) to clayey coatings and intergranular bridges (in the infill), (c) intensive weathering (cracking) of mineral grains in the infill.

  11. The pink topaz-bearing calcite, quartz, white mica veins from Ghundao Hill (North West Frontier Province, Pakistan): K/Ar age, stable isotope and REE data

    NASA Astrophysics Data System (ADS)

    Morteani, G.; Voropaev, A.

    2007-01-01

    In the area of the Ghundao Hill (Northern Frontier Province, Pakistan) an orange-yellow to cherry-red topaz is found in calcite, quartz, white mica veins crosscutting the schistosity of probably Silurian to Devonian gray limestones. Topaz with such a range of colours is traded as Imperial Topaz. Low fluorine contents of about 15 wt.%, oxygen isotope thermometry, K/Ar age determination on white mica, fluid inclusion data and mineral textures indicate that the topaz from Ghundao Hill crystallized at temperatures of about 230 °C during the Eocene Himalayan tectonothermal event and not from a late to postmagmatic granite-related fluid. The pink Topaz from Ghundao Hill shares the coexistence with carbonates, low fluorine content and a crystallization at low temperature and pressure during a regional tectonothermal event with the Imperial Topaz from Ouro Preto (Brazil) and from the Sanarka/Kamenka rivers (South Urals, Russia). The efficiency of topaz to remove fluorine from fluids at low temperature explains how topaz can be formed from metamorphic fluids that are typically poor in fluorine. High CO2 activity produced in the fluids by metamorphic decarbonatisation reactions and Al buffering by white mica prevented fluorination of carbonates stabilising topaz relative to fluorite.

  12. Carbonate facies and stratigraphic framework of middle Magdalena (middle Pennsylvanian), Hueco Mountains, west Texas

    SciTech Connect

    Lambert, L.L.; Stanton, R.J. Jr.

    1988-01-01

    The middle Magdalena of the Hueco Mountains, west Texas, is best exposed in the vicinity of Pow Wow Canyon, particularly along the western scarp of the range. It can be divided into two major depositional sequences, the lowermost of which consists predominantly of alternating bank, interbank, and shoal deposits of Atokan age. These banks are low-relief accumulations of Donezella, with coeval slackwater skeletal wackestones and interbedded deposits of foraminiferal sands. A prominent zone of intertonguing Chaetetes biostromes punctuates the middle part of this sequence. The Desmoinesian sequence begins as a series of rubbly limestones in association with abundant silicified plant remains and is interpreted as a set of paleosols. These are overlain by argillaceous, low-diversity wackestones and packstones of lagoonal origin, followed by carbonates of more open-marine circulation with abundant corals and other stenotypic fossils. In turn, these deposits are succeeded by a sequence of phylloid algal banks that increase in resistance upward to where they represent strata of the upper Magdalena. At this locality, however, the upper Magdalena is very thin because it is truncated by the pre-Hueco unconformity which, so prominent at the head of the canyon, can now be traced to the western scarp. These deposits are directly analogous to subsurface reservoir facies of the same age on the opposite side of the Diablo uplift in the Permian basin and thus provide an opportunity to generate reservoir models based on extensive outcrop exposure.

  13. Giant gas field of northern West Siberia

    SciTech Connect

    Grace, J.D.; Hart, G.F.

    1986-06-01

    The 66 fields discovered since the 1960s in the northern West Siberian basin contain at least 22 trillion m/sup 3/ (777 tcf) of proved gas, almost one-third of the world's reserves. Half of these fields are giants (> 85 billion m/sup 3/ or 3000 bcf of reserves). These include the largest and second-largest gas fields in the world-Urengoy (8.099 trillion m/sup 3/ or 286 tcf of gas) and Yamburg (4.81 trillion m/sup 3/ or 170 tcf of gas)-as well as most of the other ten largest gas fields in the world. The West Siberian basin occupies a 3.4-million km/sup 2/ (1.31-million mi/sup 2/) arctic lowland immediately east of the Ural Mountains, extending north under the Kara Sea. It is a composite basin, with Mesozoic-Cenozoic basin fill on top of a Paleozoic basin that overlies a crystalline Archean-Proterozoic framework. The productive zones in the northern basin are principally in the Neocomian section (at an average depth of 2800m or 9200 ft) and the Cenomanian section (at an average depth of 2800 m or 9200 ft) and the Cenomanian section (at an average depth of 1100 m or 3600 ft). The former contains reservoirs with gas, condensate, and oil; the latter contains two-thirds of the region's gas. Gas in Cenomanian reservoirs is almost pure methane. Hydrocarbons in Neocomian reservoirs were generated by thermal maturation of sapropelic organic matter contained principally in the Tithonian Bazhenov shale. Methane in the Cenomanian section appears to be a combination of thermogenic gas from the Bazhenov Suite (or deeper) and biogenic gas generated in the Cenomanian section itself, although workers disagree over how much gas came from each source. Continental glaciation during the Pleistocene may have been important in concentrating the methane in Cenomanian reservoirs.

  14. Timing and tectonic implications of the Pan-African Bangangte syenomonzonite, West Cameroon: Constraints from in-situ zircon U-Pb age and Hf-O isotopes

    NASA Astrophysics Data System (ADS)

    Tchouankoue, Jean Pierre; Li, Xian-Hua; Belnoun, Rose Noel Ngo; Mouafo, Lucas; Ferreira, Valderez Pinto

    2016-12-01

    The Bangangte pluton is a SW-NE elongated (5 × 20 km) massif located in the southeastern part of the Pan-African North Equatorial Fold Belt in Cameroon, consisting of two units with dominant monzonites in the south and syenites in the north. SIMS U-Pb zircon dating yields consistent emplacement ages of 585 ± 4 Ma and 583 ± 4 Ma for the southern unit and the northern unit, respectively. The Bangangte rocks display typical shoshonitic compositions characterized by Na2O + K2O > 5 wt%, K2O/Na2O ∼2, enrichment in LILE and LREE, but depletion in HFSE. Rocks from both units have similar O-Hf isotopes, with the monzonite zircons from the southern unit showing slightly higher δ18O (7.0 ± 0.4‰) but lower εHf(t) (-15.3 ± 1.4) value than the syenite zircons from southern unit (δ18O = 6.0 ± 0.4‰; εHf(t) = -14.0 ± 2.0). They were generated by partial melting of an enriched mantle source metasomatized by previous subduction processes, accompanied by crystal fractionation of pyroxene, Ti-Fe oxides and apatite, as well as crustal contamination to varying degrees. These rocks display a transitional geochemical feature of the subduction-related and within-plate shoshonites, suggesting that they were most likely emplaced in a post-collisional setting at the waning stage of the Pan-African orogeny.

  15. Spiculitic chert reservoir in Glick Field, South-Central Kansas

    SciTech Connect

    Rogers, J.P.; Longman, M.W.; Lloyd, R.M.

    1995-01-01

    Glick Field, located in Kiowa and Comanche counties of southern Kansas, was discovered in 1957 and has produced more than 362 BCF from Mississippian Osage chert, commonly referred to as the {open_quotes}Chat.{close_quotes} Other {open_quotes}CHAT{close_quotes} reservoirs in Kansas and Oklahoma produce mainly from mixed chert and dolomite beneath the pre-Pennsylvanian unconformity, but Glick Field`s reservoir is dominated by chert containing abundant sponge spicules. Glick Field is a stratigraphic trap with production ending where the spiculitic facies pinches out into tight limestones to the south and west which provide a lateral seal. Additionally, updip, to the northeast, the productive facies is truncated by the unconformity. Reworked chert conglomerates overlying the spiculitic reservoir at the unconformity also produce some gas. The spiculitic chert forming the reservoir was desposited below storm wavebase and grades laterally in all directions into echinoderm and brachiopod-rich skeletal wackestones and lime mudstones. Even where completely silicified, these associated limestone are tight. Thus, the reservoir is an in situ oval-shaped complex of internally brecciated sponge mats and bioherms capped in part by the chert conglomerate. The spiculitic chert contains up to 50% porosity in molds after sponge spicules, matrix micropores and vugs are connected in part by fracture and breccia porosity. Distribution of the sponge bioherms which form the reservoir facies was partly controlled by a subtle change on the shallow Mississippian carbonate shelf from clean skeletal limestones southward into shaly (and probably more anoxic) carbonates known locally as the {open_quotes}Cowley Facies.{close_quotes} The sponge bioherms formed most commonly just updip from this boundary, which can be mapped across southern Kansas. Thus, lithologic mapping provides a potential exploration tool with which to find other stratigraphically trapped spiculitic reservoirs in the area.

  16. Wild snakes harbor West Nile virus.

    PubMed

    Dahlin, C R; Hughes, D F; Meshaka, W E; Coleman, C; Henning, J D

    2016-12-01

    West Nile virus (WNV) has a complex eco-epidemiology with birds acting as reservoirs and hosts for the virus. Less well understood is the role of reptiles, especially in wild populations. The goal of our study was to determine whether a wild population of snakes in Pennsylvania harbored WNV. Six species of snakes were orally sampled in the summer of 2013 and were tested for the presence of WNV viral RNA using RT-PCR. Two Eastern Garter Snakes, Thamnophis sirtalis sirtalis tested positive for viral RNA (2/123, 1.62%). These results indicate a possible role for snakes in the complex transmission cycle of WNV.

  17. Advances in photonic reservoir computing

    NASA Astrophysics Data System (ADS)

    Van der Sande, Guy; Brunner, Daniel; Soriano, Miguel C.

    2017-05-01

    We review a novel paradigm that has emerged in analogue neuromorphic optical computing. The goal is to implement a reservoir computer in optics, where information is encoded in the intensity and phase of the optical field. Reservoir computing is a bio-inspired approach especially suited for processing time-dependent information. The reservoir's complex and high-dimensional transient response to the input signal is capable of universal computation. The reservoir does not need to be trained, which makes it very well suited for optics. As such, much of the promise of photonic reservoirs lies in their minimal hardware requirements, a tremendous advantage over other hardware-intensive neural network models. We review the two main approaches to optical reservoir computing: networks implemented with multiple discrete optical nodes and the continuous system of a single nonlinear device coupled to delayed feedback.

  18. Fractured petroleum reservoirs

    SciTech Connect

    Firoozabadi, A.; Chang, E.; Tang, G.Q.

    2000-01-10

    Total compressibility in a fractured reservoir is estimated using the pressure response due to gravitational potential variations. Both the moon and the sun gravitational potentials are accounted for using the full expression by inclusion of longer-period components. The semi-diurnal and diurnal pressure data show substantial long-term variations. The gravitational potential also contains the same variation trend; the ratio between the potential and pressure has a fairly uniform value over successive cycles. The computed total compressibility is also fairly constant and independent of the cycle. Results show the effects of the time interval over which the pressure measurements are performed as well as the location.

  19. Calderas and magma reservoirs

    NASA Astrophysics Data System (ADS)

    Cashman, Katharine V.; Giordano, Guido

    2014-11-01

    Large caldera-forming eruptions have long been a focus of both petrological and volcanological studies; petrologists have used the eruptive products to probe conditions of magma storage (and thus processes that drive magma evolution), while volcanologists have used them to study the conditions under which large volumes of magma are transported to, and emplaced on, the Earth's surface. Traditionally, both groups have worked on the assumption that eruptible magma is stored within a single long-lived melt body. Over the past decade, however, advances in analytical techniques have provided new views of magma storage regions, many of which provide evidence of multiple melt lenses feeding a single eruption, and/or rapid pre-eruptive assembly of large volumes of melt. These new petrological views of magmatic systems have not yet been fully integrated into volcanological perspectives of caldera-forming eruptions. Here we explore the implications of complex magma reservoir configurations for eruption dynamics and caldera formation. We first examine mafic systems, where stacked-sill models have long been invoked but which rarely produce explosive eruptions. An exception is the 2010 eruption of Eyjafjallajökull volcano, Iceland, where seismic and petrologic data show that multiple sills at different depths fed a multi-phase (explosive and effusive) eruption. Extension of this concept to larger mafic caldera-forming systems suggests a mechanism to explain many of their unusual features, including their protracted explosivity, spatially variable compositions and pronounced intra-eruptive pauses. We then review studies of more common intermediate and silicic caldera-forming systems to examine inferred conditions of magma storage, time scales of melt accumulation, eruption triggers, eruption dynamics and caldera collapse. By compiling data from large and small, and crystal-rich and crystal-poor, events, we compare eruptions that are well explained by simple evacuation of a zoned

  20. Reservoir management cost-cutting

    SciTech Connect

    Gulati, M.S.

    1996-12-31

    This article by Mohinder S. Gulati, Chief Engineer, Unocal Geothermal Operations, discusses cost cutting in geothermal reservoir management. The reservoir engineer or geoscientist can make a big difference in the economical outcome of a project by improving well performance and thus making geothermal energy more competitive in the energy marketplace. Bringing plants online in less time and proving resources to reduce the cycle time are some of the ways to reduce reservoir management costs discussed in this article.

  1. Encapsulated microsensors for reservoir interrogation

    SciTech Connect

    Scott, Eddie Elmer; Aines, Roger D.; Spadaccini, Christopher M.

    2016-03-08

    In one general embodiment, a system includes at least one microsensor configured to detect one or more conditions of a fluidic medium of a reservoir; and a receptacle, wherein the receptacle encapsulates the at least one microsensor. In another general embodiment, a method include injecting the encapsulated at least one microsensor as recited above into a fluidic medium of a reservoir; and detecting one or more conditions of the fluidic medium of the reservoir.

  2. Application of Reservoir Characterization and Advanced Technology to Improve Recovery and Economics in a Lower Quality Shallow Shelf Carbonate Reservoir

    SciTech Connect

    Rebecca Egg

    2002-09-30

    The OXY-operated Class 2 Project at West Welch is designed to demonstrate how the use of advanced technology can improve the economics of miscible CO{sub 2} injection projects in lower quality Shallow Shelf Carbonate reservoirs. The research and design phase (Budget Period 1) primarily involved advanced reservoir characterization. The current demonstration phase (Budget Period 2) is the implementation of the reservoir management plan for an optimum miscible CO{sub 2} flood design based on the reservoir characterization. Although Budget Period 1 for the Project officially ended 12/31/96, reservoir characterization and simulation work continued during the Budget Period 2. During the fifth and sixth annual reporting periods (8/3/98-8/2/00) covered by this report, work continued on interpretation of the cross well seismic data to create porosity and permeability profiles which were distributed into the reservoir geostatistically. The initial interwell seismic CO{sub 2} monitor survey was conducted, the acquired data processed and interpretation started. Only limited well work and facility construction was conducted in the project area. The CO{sub 2} injection initiated in October 1997 was continued, although the operator had to modify the operating plan in response to low injection rates, well performance and changes in CO{sub 2} supply. CO{sub 2} injection was focused in a smaller area to increase the reservoir processing rate. By the end of the reporting period three producers had shown sustained oil rate increases and ten wells had experienced gas (CO{sub 2}) breakthrough.

  3. Improved Methodology for Estimating Recovery Factor of Carbonate Reservoirs Using Geological Parameters

    NASA Astrophysics Data System (ADS)

    Park, E.; Lee, M.; Keehm, Y.; Kwon, Y. K.

    2014-12-01

    Carbonate reservoirs are highly complicated and heterogeneous than typical sandstone reservoirs, because of their depositional and diagenetic complexity. Therefore estimating the prospectiveness in an early stage of reservoir development is not an easy task. Typically we use an empirical equation, which calculates recovery factor (RF) for this assessment. Since the equation was created with reservoir parameters (porosity, water saturation, permeability, viscosity, pressure, etc.) from sandstone reservoirs, the applicability to carbonate reservoirs is questionable. We compiled 97 carbonate reservoirs and created a database with reservoir properties, geological information, and production data. First, we applied the existing empirical equation to our data and the results were disappointing: the predicted RF's was far off from actual values and correlation was also poor. We then modified the equation by adding geological parameters, such as play type, reservoir age, reservoir type, porosity type, trap information. The new equation was modelled by determining the coefficient of each parameter using least-square minimizing scheme. The modified equation estimated the recovery factor much better and more reliably. We think that the additional geological information is essential for accurate assessment of carbonate reservoirs in early stage of development, since the carbonate reservoirs show high variability and complexity by depositional and diagenetic changes. Acknowledgements: This research was supported by the Basic Research Project of the Korea Institute of Geoscience and Mineral Resources (KIGAM) funded by the Ministry of Trade, Industry and Energy of Korea (GP2012-029).

  4. All-optical reservoir computing.

    PubMed

    Duport, François; Schneider, Bendix; Smerieri, Anteo; Haelterman, Marc; Massar, Serge

    2012-09-24

    Reservoir Computing is a novel computing paradigm that uses a nonlinear recurrent dynamical system to carry out information processing. Recent electronic and optoelectronic Reservoir Computers based on an architecture with a single nonlinear node and a delay loop have shown performance on standardized tasks comparable to state-of-the-art digital implementations. Here we report an all-optical implementation of a Reservoir Computer, made of off-the-shelf components for optical telecommunications. It uses the saturation of a semiconductor optical amplifier as nonlinearity. The present work shows that, within the Reservoir Computing paradigm, all-optical computing with state-of-the-art performance is possible.

  5. U-Pb LA-ICP-MS detrital zircon ages from the Cambrian of Al Qarqaf Arch, central-western Libya: Provenance of the West Gondwanan sand sea at the dawn of the early Palaeozoic

    NASA Astrophysics Data System (ADS)

    Altumi, Muftah Mahmud; Elicki, Olaf; Linnemann, Ulf; Hofmann, Mandy; Sagawe, Anja; Gärtner, Andreas

    2013-03-01

    Detrital zircons from various stratigraphic levels of the sandstone-dominated Cambrian Hasawnah Formation of the Al Qarqaf Arch type area (central-western Libya, Saharan Metacraton area) were geochronologically investigated for the first time by LA-ICP-MS techniques for U, Th, and Pb isotopes. Of 720 analyzed grains, 329 were concordant. Of the total, about 60% of the U-Pb zircon ages are Neoproterozoic and earliest Cambrian and cluster at c. 700-680, 670-650, 615-610, 590, 570-560, and c. 540-525 Ma. These zircon populations are interpreted as detrital material derived from the Pan-African and possibly to a smaller proportion from the Cadomian orogen situated marginal to northwestern Gondwana. A few slightly older Neoproterozoic ages (c. 950-750 Ma) point to rifting events related to the dispersal of the Rodinia supercontinent. A minority of zircons became formed during the configuration of Rodinia and cluster around the Mesoproterozoic-Neoproterozoic boundary (1039 ± 11, 1006 ± 12 and 993 ± 13 Ma). Further, some early Mesoproterozoic zircon ages had been found (1592 ± 39 and 1475 ± 20 Ma). The potential source area for the Mesoproterozoic zircons is interpreted to have been far distant from the Al Qarqaf Arch, probably concealed within the Arabian-Nubian Shield or situated in Chad, or in the Congo and Tanzania cratons. There is still no evidence for the existence of massive Mesoproterozoic crust in the Saharan Metacraton area. A considerable proportion (28%) of zircons represents Palaeoproterozoic populations at c. 2.4-2.3 Ga, and c. 2.2-1.6 Ga. Less than 5% of all zircons are Archaean in age (c. 3.4-3.25 Ga, c. 2.95-2.7 Ga, c. 2.6-2.5 Ga). A potential source area for Palaeoproterozoic and Archaean zircon grains is the West African Craton and the western part of the Saharan Metacraton. The best candidates for the main source region for the sandstones of the Hasawnah Formation in the Al Qarqaf Arch type area are the Neoproterozoic-early Cambrian orogens of

  6. Calderas and magma reservoirs

    NASA Astrophysics Data System (ADS)

    Cashman, Katharine; Giordano, Guido

    2015-04-01

    Large caldera-forming eruptions have long been a focus of both petrological and volcanological studies; traditionally, both have assumed that eruptible magma is stored within a single long-lived melt body. Over the past decade, however, advances in analytical techniques have provided new views of magma storage regions, many of which provide evidence of multiple melt lenses feeding a single eruption, and/or rapid pre-eruptive assembly of large volumes of melt. These new petrological views of magmatic systems have not yet been fully integrated into volcanological perspectives of caldera-forming eruptions. We discuss the implications of syn-eruptive melt extraction from complex, rather than simple, reservoirs and its potential control over eruption size and style, and caldera collapse timing and style. Implications extend to monitoring of volcanic unrest and eruption progress under conditions where successive melt lenses may be tapped. We conclude that emerging views of complex magma reservoir configurations provide exciting opportunities for re-examining volcanological concepts of caldera-forming systems

  7. Carbon Dioxide Emissions from Reservoirs in the Lower Jordan Watershed

    PubMed Central

    Alshboul, Zeyad; Lorke, Andreas

    2015-01-01

    We have analyzed monthly hydrological, meteorological and water quality data from three irrigation and drinking water reservoirs in the lower Jordan River basin and estimated the atmospheric emission rates of CO2. The data were collected between 2006 and 2013 and show that the reservoirs, which differ in size and age, were net sources of CO2. The estimated surface fluxes were comparable in magnitude to those reported for hydroelectric reservoirs in the tropical and sub-tropical zones. Highest emission rates were observed for a newly established reservoir, which was initially filled during the sampling period. In the two older reservoirs, CO2 partial pressures and fluxes were significantly decreasing during the observation period, which could be related to simultaneously occurring temporal trends in water residence time and chemical composition of the water. The results indicate a strong influence of water and reservoir management (e.g. water consumption) on CO2 emission rates, which is affected by the increasing anthropogenic pressure on the limited water resources in the study area. The low wind speed and relatively high pH favored chemical enhancement of the CO2 gas exchange at the reservoir surfaces, which caused on average a four-fold enhancement of the fluxes. A sensitivity analysis indicates that the uncertainty of the estimated fluxes is, besides pH, mainly affected by the poorly resolved wind speed and resulting uncertainty of the chemical enhancement factor. PMID:26588241

  8. The reservoir model: a differential equation model of psychological regulation.

    PubMed

    Deboeck, Pascal R; Bergeman, C S

    2013-06-01

    Differential equation models can be used to describe the relationships between the current state of a system of constructs (e.g., stress) and how those constructs are changing (e.g., based on variable-like experiences). The following article describes a differential equation model based on the concept of a reservoir. With a physical reservoir, such as one for water, the level of the liquid in the reservoir at any time depends on the contributions to the reservoir (inputs) and the amount of liquid removed from the reservoir (outputs). This reservoir model might be useful for constructs such as stress, where events might "add up" over time (e.g., life stressors, inputs), but individuals simultaneously take action to "blow off steam" (e.g., engage coping resources, outputs). The reservoir model can provide descriptive statistics of the inputs that contribute to the "height" (level) of a construct and a parameter that describes a person's ability to dissipate the construct. After discussing the model, we describe a method of fitting the model as a structural equation model using latent differential equation modeling and latent distribution modeling. A simulation study is presented to examine recovery of the input distribution and output parameter. The model is then applied to the daily self-reports of negative affect and stress from a sample of older adults from the Notre Dame Longitudinal Study on Aging.

  9. Carbon Dioxide Emissions from Reservoirs in the Lower Jordan Watershed.

    PubMed

    Alshboul, Zeyad; Lorke, Andreas

    2015-01-01

    We have analyzed monthly hydrological, meteorological and water quality data from three irrigation and drinking water reservoirs in the lower Jordan River basin and estimated the atmospheric emission rates of CO2. The data were collected between 2006 and 2013 and show that the reservoirs, which differ in size and age, were net sources of CO2. The estimated surface fluxes were comparable in magnitude to those reported for hydroelectric reservoirs in the tropical and sub-tropical zones. Highest emission rates were observed for a newly established reservoir, which was initially filled during the sampling period. In the two older reservoirs, CO2 partial pressures and fluxes were significantly decreasing during the observation period, which could be related to simultaneously occurring temporal trends in water residence time and chemical composition of the water. The results indicate a strong influence of water and reservoir management (e.g. water consumption) on CO2 emission rates, which is affected by the increasing anthropogenic pressure on the limited water resources in the study area. The low wind speed and relatively high pH favored chemical enhancement of the CO2 gas exchange at the reservoir surfaces, which caused on average a four-fold enhancement of the fluxes. A sensitivity analysis indicates that the uncertainty of the estimated fluxes is, besides pH, mainly affected by the poorly resolved wind speed and resulting uncertainty of the chemical enhancement factor.

  10. Identification and quantification of fracture behavior through reservoir simulation

    SciTech Connect

    Cline, S. |

    1995-08-01

    This study demonstrated the use of reservoir simulation as a tool for quantifying and describing the relative significance of fracture and matrix flow units to overall reservoir storage capacity and transmissibility in a field development example. A high matrix porosity Pennsylvanian age sandstone oil reservoir, that is currently undergoing the early stages of secondary recovery by waterflood, was studied. Unexpected early water breakthrough indicated the presence of a high directional permeability fracture system superimposed on the high porosity matrix system. To further understand the reservoir behavior, improve field performance and to quantify the relative contributions of fracture and matrix units to permeability and storage capacity, a reservoir simulation and characterization project was initiated. Well test, well log, tracer and geologic data were integrated into the simulation project. The integrated study indicated that the fractures exhibited high directional permeability but low storage capacity relative to the matrix portion of the reservoir. Although fractures heavily influenced overall fluid flow behavior, they did not contain large storage capacity. The system had a low calculated fracture intensity index. Reservoir simulation enabled the quantification of the relative importance of the two flow systems which in turn had a large impact on total reserves estimates and production forecasting. Simulation results indicated a need to realign injector and producer patterns which improved production rates and ultimate recovery.

  11. Reservoir Modeling for Production Management

    SciTech Connect

    Brown, Donald W.

    1989-03-21

    For both petroleum and geothermal resources, many of the reservoirs are fracture dominated--rather than matrix-permeability controlled. For such reservoirs, a knowledge of the pressure-dependent permeability of the interconnected system of natural joints (i.e., pre-existing fractures) is critical to the efficient exploitation of the resource through proper pressure management. Our experience and that reported by others indicates that a reduction in the reservoir pressure sometimes leads to an overall reduction in production rate due to the ''pinching off'' of the joint network, rather than the anticipated increase in production rate. This effect occurs not just in the vicinity of the wellbore, where proppants are sometimes employed, but throughout much of the reservoir region. This follows from the fact that under certain circumstances, the decline in fracture permeability (or conductivity) with decreasing reservoir pressure exceeds the far-field reservoir ''drainage'' flow rate increase due to the increased pressure gradient. Further, a knowledge of the pressure-dependent joint permeability could aid in designing more appropriate secondary recovery strategies in petroleum reservoirs or reinjection procedures for geothermal reservoirs.

  12. An improved reservoir oxide cathode

    NASA Astrophysics Data System (ADS)

    Wang, Xiaoxia; Liao, Xianheng; Luo, Jirun; Zhao, Qinglan

    2005-09-01

    A new type of reservoir oxide cathode has been developed in IECAS. The emission characteristics of the cathode are tested. The results show the new cathode has higher emission current density and better resistance to poisoning at same operating condition compared with those of conventional reservoir oxide cathode.

  13. HEC Activities in Reservoir Analysis.

    DTIC Science & Technology

    1980-06-01

    June 1979. Now, HEC-5, "Simulation of Flood Con- trol and Conservation Systems," (9) is our primary reservoir simulation program. Since its June release...are being incorporated into the reservoir simulation model HEC-5. The objective is to provide a computer program and methodology for total water

  14. Meandering stream reservoirs

    SciTech Connect

    Richardson, J.G.; Sangree, J.B.; Sneider, R.M.

    1987-12-01

    Braided stream deposits, described in a previous article in this series, and meandering stream deposits commonly are excellent reservoirs. Meandering high-sinuousity channels are found on flat alluvial plains with slopes less than 1 1/2/sup 0/ (0.026 rad). These rivers have wide ranges of discharges from low-water flow to flood stage. Two main processes are responsible for development of sand bodies. These are point-bar deposits left by channel migration, and oxbow-lake deposits left in loops of the river course abandoned when the stream cuts a new course during flooding. Extremely high floods spill over the banks and deposit sheets of very fine sand, silt, and clay onto the flood plain.

  15. FRACTURED PETROLEUM RESERVOIRS

    SciTech Connect

    Abbas Firoozabadi

    1999-06-11

    The four chapters that are described in this report cover a variety of subjects that not only give insight into the understanding of multiphase flow in fractured porous media, but they provide also major contribution towards the understanding of flow processes with in-situ phase formation. In the following, a summary of all the chapters will be provided. Chapter I addresses issues related to water injection in water-wet fractured porous media. There are two parts in this chapter. Part I covers extensive set of measurements for water injection in water-wet fractured porous media. Both single matrix block and multiple matrix blocks tests are covered. There are two major findings from these experiments: (1) co-current imbibition can be more efficient than counter-current imbibition due to lower residual oil saturation and higher oil mobility, and (2) tight fractured porous media can be more efficient than a permeable porous media when subjected to water injection. These findings are directly related to the type of tests one can perform in the laboratory and to decide on the fate of water injection in fractured reservoirs. Part II of Chapter I presents modeling of water injection in water-wet fractured media by modifying the Buckley-Leverett Theory. A major element of the new model is the multiplication of the transfer flux by the fractured saturation with a power of 1/2. This simple model can account for both co-current and counter-current imbibition and computationally it is very efficient. It can be orders of magnitude faster than a conventional dual-porosity model. Part II also presents the results of water injection tests in very tight rocks of some 0.01 md permeability. Oil recovery from water imbibition tests from such at tight rock can be as high as 25 percent. Chapter II discusses solution gas-drive for cold production from heavy-oil reservoirs. The impetus for this work is the study of new gas phase formation from in-situ process which can be significantly

  16. Tertiary carbonate reservoirs in Indonesia

    SciTech Connect

    Nayoan, G.A.S.; Arpandi; Siregar, M.

    1981-01-01

    Hydrocarbon production from Tertiary carbonate reservoirs accounted for ca. 10% of daily Indonesian production at the beginning of 1978. Environmentally, the reservoirs appear as parts of reef complexes and high-energy carbonate deposits within basinal areas situated mainly in the back arc of the archipelago. Good porosities of the reservoirs are represented by vugular/moldic and intergranular porosity types. The reservoirs are capable of producing prolific amounts of hydrocarbons: production tests in Salawati-Irian Jaya reaches maximum values of 32,000 bpd, and in Arun-North Sumatra tests recorded 200 MMCF gas/day. Significant hydrocarbon accumulations are related to good reservoir rocks in carbonates deposited as patch reefs, pinnacle reefs, and platform complexes. Exploration efforts expand continuously within carbonate formations which are extensive horizontally as well as vertically in the Tertiary stratigraphic column.

  17. Stochastic thermodynamics with information reservoirs

    NASA Astrophysics Data System (ADS)

    Barato, Andre C.; Seifert, Udo

    2014-10-01

    We generalize stochastic thermodynamics to include information reservoirs. Such information reservoirs, which can be modeled as a sequence of bits, modify the second law. For example, work extraction from a system in contact with a single heat bath becomes possible if the system also interacts with an information reservoir. We obtain an inequality, and the corresponding fluctuation theorem, generalizing the standard entropy production of stochastic thermodynamics. From this inequality we can derive an information processing entropy production, which gives the second law in the presence of information reservoirs. We also develop a systematic linear response theory for information processing machines. For a unicyclic machine powered by an information reservoir, the efficiency at maximum power can deviate from the standard value of 1 /2 . For the case where energy is consumed to erase the tape, the efficiency at maximum erasure rate is found to be 1 /2 .

  18. Prevalence of head lice and hygiene practices among women over twelve years of age in Sindh, Balochistan, and North West Frontier Province: National Health Survey of Pakistan, 1990-1994

    PubMed Central

    2011-01-01

    Background Head lice infestation is an infection of the scalp and skin which causes blood loss, discomfort, and social and psychological distress with the possibility of secondary bacterial infections occurring at scratch sites. In Pakistan, although some small scale studies have been conducted to investigate prevalence of head lice in school children and the general population, no population based estimates have been reported. The National Health Survey of Pakistan (NHSP 1990 - 94) was a nationally representative health examination survey of the Pakistani population. The NHSP is the first population based household survey to collect data on the prevalence of head lice in adult women in Pakistan. In this paper we use data from the NHSP to present an epidemiological profile of personal hygiene practices and head lice infestation among women aged 12 years or older in three provinces of Pakistan; Balochistan, Sindh and North West Frontier Province (NWFP). Results Overall about 7% women aged 12 years and older suffered from head lice infestation. Multivariable logistic regression analysis identified factors independently associated with presence of head lice. Age less than 16 years and crowding at home were associated with higher infestation-rates. The impact of household socio-economic status on infestation rates among women was different in urban and rural settings; urban women with low socio-economic status were more vulnerable than similar women in rural settings. Bathing infrequently in summer was associated with higher prevalence rates only in Sindh, possibly due to the fact that among the three provinces Sindh has a hotter and more humid summer. Conclusions The results of our analysis of NHSP indicate high levels of head lice infestation among girls and women in the three Provinces. The epidemiological profile of hygienic practices of women indicated that NWFP and Balochistan as compared to Sindh, and rural as compared to urban areas were less developed with

  19. Prevalence of head lice and hygiene practices among women over twelve years of age in Sindh, Balochistan, and North West Frontier Province: National Health Survey of Pakistan, 1990-1994.

    PubMed

    Mahmud, Sadia; Pappas, Gregory; Hadden, Wilbur C

    2011-02-02

    Head lice infestation is an infection of the scalp and skin which causes blood loss, discomfort, and social and psychological distress with the possibility of secondary bacterial infections occurring at scratch sites. In Pakistan, although some small scale studies have been conducted to investigate prevalence of head lice in school children and the general population, no population based estimates have been reported. The National Health Survey of Pakistan (NHSP 1990 - 94) was a nationally representative health examination survey of the Pakistani population. The NHSP is the first population based household survey to collect data on the prevalence of head lice in adult women in Pakistan. In this paper we use data from the NHSP to present an epidemiological profile of personal hygiene practices and head lice infestation among women aged 12 years or older in three provinces of Pakistan; Balochistan, Sindh and North West Frontier Province (NWFP). Overall about 7% women aged 12 years and older suffered from head lice infestation. Multivariable logistic regression analysis identified factors independently associated with presence of head lice. Age less than 16 years and crowding at home were associated with higher infestation-rates. The impact of household socio-economic status on infestation rates among women was different in urban and rural settings; urban women with low socio-economic status were more vulnerable than similar women in rural settings. Bathing infrequently in summer was associated with higher prevalence rates only in Sindh, possibly due to the fact that among the three provinces Sindh has a hotter and more humid summer. The results of our analysis of NHSP indicate high levels of head lice infestation among girls and women in the three Provinces. The epidemiological profile of hygienic practices of women indicated that NWFP and Balochistan as compared to Sindh, and rural as compared to urban areas were less developed with respect to access to water supply

  20. Water resources review: Ocoee reservoirs, 1990

    SciTech Connect

    Cox, J.P.

    1990-08-01

    Tennessee Valley Authority (TVA) is preparing a series of reports to make technical information on individual TVA reservoirs readily accessible. These reports provide a summary of reservoir purpose and operation; physical characteristics of the reservoir and watershed; water quality conditions; aquatic biological conditions; and designated, actual and potential uses of the reservoir and impairments of those use. This reservoir status report addressed the three Ocoee Reservoirs in Polk County, Tennessee.

  1. Collapsible sheath fluid reservoirs for flow cytometers

    DOEpatents

    Mark, Graham A.

    2000-01-01

    The present invention is a container in the form of a single housing for holding fluid, including a first collapsible reservoir having a first valve. The first reservoir initially contains a volume of fluid. The container also includes a second reservoir, initially empty (or substantially empty), expandable to a second volume. The second reservoir has a second valve. As the volume of said first reservoir decreases, the volume of the second reservoir proportionally increases.

  2. 13. VIEW OF BRIDGE, LOOKING WEST FROM THE WEST TOWER ...

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

    13. VIEW OF BRIDGE, LOOKING WEST FROM THE WEST TOWER TO THE MAIN SUSPENSION CABLE WEST ANCHORAGE. February 1987 - Verde River Sheep Bridge, Spanning Verde River (Tonto National Forest), Cave Creek, Maricopa County, AZ

  3. 7. CLOSER OBLIQUE VIEW OF WEST TRUSS AND WEST SIDE ...

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

    7. CLOSER OBLIQUE VIEW OF WEST TRUSS AND WEST SIDE OF SOUTH ABUTMENT; VIEW TO NORTHEAST. - Mitchell's Mill Bridge, Spanning Winter's Run on Carrs Mill Road, west of Bel Air, Bel Air, Harford County, MD

  4. 110. WEST CHESTNUT STREET PAPTIST CHURCH AT 1725 WEST CHESTNUT ...

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

    110. WEST CHESTNUT STREET PAPTIST CHURCH AT 1725 WEST CHESTNUT STREET, WEST SIDE - Russell Neighborhood, Bounded by Congress & Esquire Alley, Fifteenth & Twenty-first Streets, Louisville, Jefferson County, KY

  5. 300. VACANT LOTS BETWEEN WEST MADISON ALLEY AND WEST CHESTNUT ...

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

    300. VACANT LOTS BETWEEN WEST MADISON ALLEY AND WEST CHESTNUT STREET, TOWARD WEST - Russell Neighborhood, Bounded by Congress & Esquire Alley, Fifteenth & Twenty-first Streets, Louisville, Jefferson County, KY

  6. Analysis of real-time reservoir monitoring : reservoirs, strategies, & modeling.

    SciTech Connect

    Mani, Seethambal S.; van Bloemen Waanders, Bart Gustaaf; Cooper, Scott Patrick; Jakaboski, Blake Elaine; Normann, Randy Allen; Jennings, Jim; Gilbert, Bob; Lake, Larry W.; Weiss, Chester Joseph; Lorenz, John Clay; Elbring, Gregory Jay; Wheeler, Mary Fanett; Thomas, Sunil G.; Rightley, Michael J.; Rodriguez, Adolfo; Klie, Hector; Banchs, Rafael; Nunez, Emilio J.; Jablonowski, Chris

    2006-11-01

    The project objective was to detail better ways to assess and exploit intelligent oil and gas field information through improved modeling, sensor technology, and process control to increase ultimate recovery of domestic hydrocarbons. To meet this objective we investigated the use of permanent downhole sensors systems (Smart Wells) whose data is fed real-time into computational reservoir models that are integrated with optimized production control systems. The project utilized a three-pronged approach (1) a value of information analysis to address the economic advantages, (2) reservoir simulation modeling and control optimization to prove the capability, and (3) evaluation of new generation sensor packaging to survive the borehole environment for long periods of time. The Value of Information (VOI) decision tree method was developed and used to assess the economic advantage of using the proposed technology; the VOI demonstrated the increased subsurface resolution through additional sensor data. Our findings show that the VOI studies are a practical means of ascertaining the value associated with a technology, in this case application of sensors to production. The procedure acknowledges the uncertainty in predictions but nevertheless assigns monetary value to the predictions. The best aspect of the procedure is that it builds consensus within interdisciplinary teams The reservoir simulation and modeling aspect of the project was developed to show the capability of exploiting sensor information both for reservoir characterization and to optimize control of the production system. Our findings indicate history matching is improved as more information is added to the objective function, clearly indicating that sensor information can help in reducing the uncertainty associated with reservoir characterization. Additional findings and approaches used are described in detail within the report. The next generation sensors aspect of the project evaluated sensors and packaging

  7. Prevalence and factors associated with unmet need for family planning among the currently married reproductive age women in Shire-Enda- Slassie, Northern West of Tigray, Ethiopia 2015: a community based cross-sectional study.

    PubMed

    Gebre, Gelawdiwos; Birhan, Nigussie; Gebreslasie, Kahsay

    2016-01-01

    Unmet family planning is one of the common causes for low contraceptive prevalence rate in developing countries including Ethiopia. Thus, this study designed to assess the prevalence and associated factors of unmet need in Shire Endaslassie town, Northern west of Tigray, Ethiopia. A community based cross sectional study design was employed. Multistage sampling technique was employed and data were collected using a semi-structured questionnaire by interviewer administered technique. Questionnaires were reviewed and checked for completeness, accuracy and consistency. Reviewed data were entered to Epi info 7 and analyzed by SPSS version 20 statistical software. Variables with P-value of less than 0.2 in bivariate analyses were entered for multivariate analysis and AOR at 95% CI with p-value of less than 0.05 were considered as significant variables. The overall unmet need for family planning in the study area was 109(21.4%). 74(14.5%) for spacing and 35(6.9%) for limiting. Age group of 35-39 and >=40 (AOR= 2.7,95%CI:1.1,6.5), (AOR = 2.65, 95%CI:1.10, 6.40) respectively, decided numbers of desired children more than five (AOR = O.48, 95%CI: 0.28, 0.80), discussions of client with heath care providers (AOR = 6.32, 95%CI: 2.56, 15.58), previous use of modern family planning (AOR = 2.29, 95%CI, 1.20, 4.34) were significantly associated with unmet need for family planning. Unmet need for family planning in the study area was high, so continuous discussion on modern family planning with community health workers and encouraging of women to decide desired numbers of children of less than five in general are better to be strengthened.

  8. Data requirements and acquisition for reservoir characterization

    SciTech Connect

    Jackson, S.; Chang, Ming Ming; Tham, Min.

    1993-03-01

    This report outlines the types of data, data sources and measurement tools required for effective reservoir characterization, the data required for specific enhanced oil recovery (EOR) processes, and a discussion on the determination of the optimum data density for reservoir characterization and reservoir modeling. The two basic sources of data for reservoir characterization are data from the specific reservoir and data from analog reservoirs, outcrops, and modern environments. Reservoir data can be divided into three broad categories: (1) rock properties (the container) and (2) fluid properties (the contents) and (3)interaction between reservoir rock and fluid. Both static and dynamic measurements are required.

  9. EXPLOITATION AND OPTIMIZATION OF RESERVOIR PERFORMANCE IN HUNTON FORMATION, OKLAHOMA

    SciTech Connect

    Mohan Kelkar

    2005-02-01

    Hunton formation in Oklahoma has displayed some unique production characteristics. These include high initial water-oil and gas-oil ratios, decline in those ratios over time and temporary increase in gas-oil ratio during pressure build up. The formation also displays highly complex geology, but surprising hydrodynamic continuity. This report addresses three key issues related specifically to West Carney Hunton field and, in general, to any other Hunton formation exhibiting similar behavior: (1) What is the primary mechanism by which oil and gas is produced from the field? (2) How can the knowledge gained from studying the existing fields can be extended to other fields which have the potential to produce? (3) What can be done to improve the performance of this reservoir? We have developed a comprehensive model to explain the behavior of the reservoir. By using available production, geological, core and log data, we are able to develop a reservoir model which explains the production behavior in the reservoir. Using easily available information, such as log data, we have established the parameters needed for a field to be economically successful. We provide guidelines in terms of what to look for in a new field and how to develop it. Finally, through laboratory experiments, we show that surfactants can be used to improve the hydrocarbons recovery from the field. In addition, injection of CO{sub 2} or natural gas also will help us recover additional oil from the field.

  10. Bats as 'special' reservoirs for emerging zoonotic pathogens.

    PubMed

    Brook, Cara E; Dobson, Andrew P

    2015-03-01

    The ongoing West African Ebola epidemic highlights a recurring trend in the zoonotic emergence of virulent pathogens likely to come from bat reservoirs that has caused epidemiologists to ask 'Are bats special reservoirs for emerging zoonotic pathogens?' We collate evidence from the past decade to delineate mitochondrial mechanisms of bat physiology that have evolved to mitigate oxidative stress incurred during metabolically costly activities such as flight. We further describe how such mechanisms might have generated pleiotropic effects responsible for tumor mitigation and pathogen control in bat hosts. These synergisms may enable 'special' tolerance of intracellular pathogens in bat hosts; paradoxically, this may leave them more susceptible to immunopathological morbidity when attempting to clear extracellular infections such as 'white-nose syndrome' (WNS). Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Geochemical assessment of metals and dioxin in sediment from the San Carlos Reservoir and the Gila, San Carlos, and San Francisco Rivers, Arizona

    USGS Publications Warehouse

    Church, Stanley E.; Choate, LaDonna M.; Marot, Marci E.; Fey, David L.; Adams, Monique; Briggs, Paul H.; Brown, Zoe Ann

    2005-01-01

    In October 2004, we sampled stream-bed sediment, terrace sediment, and sediment from the San Carlos Reservoir to determine the spatial and chronological variation of six potentially toxic metals-Cu, Pb, Zn, Cd, As, and Hg. Water levels in the San Carlos Reservoir were at a 20-year low at an elevation of 2,409 ft (734.3 m). Four cores were taken from the reservoir: one from the San Carlos River arm, one from the Gila River arm, and two from the San Carlos Reservoir just west of the Pinal County line. Radioisotope chronometry (7Be, 137Cs, and 210Pb) conducted on sediment from the reservoir cores provides a good chronological record back to 1959. Chronology prior to that, during the 1950s, is based on our interpretation of the 137Cs anomaly in reservoir cores. During and prior to the 1950s, the reservoir was dry and sediment-accumulation rates were irregular; age control based on radioisotope data was not possible. We recovered sediment at the base of one 4-m-long core that may date back to the late 1930s. The sedimentological record contains two discrete events, one about 1978-83 and one about 1957, where the Cu concentration in reservoir sediment exceeded recommended sediment quality guidelines and should have had an effect on sensitive aquatic and benthic organisms. Concentrations of Zn determined in sediment deposited during the 1957(?) event also exceeded recommended sediment quality guidelines. Concentration data for Cu from the four cores clearly indicate that the source of this material was upstream on the Gila River. Lead isotope data, coupled with the geochemical data from a 2M HCl-1 percent H2O2 leach of selected sediment samples, show two discrete populations of data. One represents the dominant sediment load derived from the Safford Valley, and a second reflects sediment derived from the San Francisco River. The Cu concentration spikes in the reservoir cores have chemical and Pb isotope signatures that indicate that deposits in a porphyry copper deposit

  12. Geologic controls on reservoir properties in gas-bearing middle and Upper Devonian rocks, southern Appalachian basin

    SciTech Connect

    Vessell, R.K.; Davies, D.K.

    1988-08-01

    Porosities and permeabilities have been measured for a wide range of nonfractured Devonian lithologies in 23 wells from southeastern Ohio, eastern Kentucky, West Virginia, and Virginia. These reservoir properties can be related directly to the geometry of the pore system. Pore geometry, in turn, is a function of rock lithology and mineralogy. Despite the lithologic complexity of the Devonian sequence, reservoir quality can be related to a small number of differing pore geometries.

  13. Hydromechanics of Reservoir Induced Seismicity

    NASA Astrophysics Data System (ADS)

    Dura-Gomez, Inmaculada

    Data from five reservoirs were analyzed to investigate the various factors and possible pore pressure thresholds associated with Reservoir Induced Seismicity (RIS). Data was obtained from the following reservoirs: Koyna and Warna Reservoirs in India, Itoiz Reservoir in the western Pyrenees, Spain, and Jocassee and Monticello Reservoirs in South Carolina, U.S.A. Koyna Reservoir is one out of four reservoirs in the world where M≥6.0 induced earthquakes have occurred, whereas Warna Reservoir accounts for one out of ten cases with 5.0≤M≤5.9 induced earthquakes. Induced seismicity in the Koyna-Warna region is associated with annual filling cycles in the two reservoirs, large water level changes (30 to 45 m) and the presence of regional scale fractures. The Koyna-Warna case includes 19 M≥5.0 earthquakes at non-repeating hypocenters. The calculation of excess pore pressures associated with these earthquakes suggests values >300 kPa or >600 kPa, before or after 1993 respectively. The need for larger pore pressures from 1993 suggests that M≥5 earthquakes were induced on stronger faults in the region. The exceedance of the previous water level maxima (stress memory) is the most important, although not determining factor in inducing these M≥5.0 earthquakes. Itoiz Reservoir is one of twenty nine reservoirs with 4.0≤M≤4.9 induced earthquakes. The analysis of the RIS associated with the Itoiz Reservoir impoundment, between January 2004 and the end of 2008, shows that that pore pressures diffuse away from Itoiz Reservoir through the carbonate megabreccia systems of the Early to Middle Eocene Hecho Group, and a series of near-vertical thrust faults above the gently dipping Gavarnie thrust. Excess diffused pore pressures destabilize saturated critically stressed seismogenic fractures where RIS takes place. In particular, M≥3.0 earthquakes in the region are associated with excess pore pressures of the order of 100 to 200 kPa. Jocassee and Monticello Reservoirs in

  14. [West Nile fever].

    PubMed

    Takasaki, Tomohiko

    2005-12-01

    West Nile virus was first detected in North America in 1999 and has spread throughout the United States and Canada and into Mexico and the Caribbean. The cases of encephalitis in New York were diagnosed as Saint Louis encephalitis which was endemic in the North America. However, dead crows and dead flamingo were found around the same time in New York. American birds seldom die by Saint Louis encephalitis virus infection. According to viral isolation and sequencing of the genome, the causative agent of unknown encephalitis was West Nile virus which was a member of Flaviviridae which cause fever, meningitis and encephalitis. West Nile virus is still active in North America in summer season, 1999 -2005. CDC enlightens people how to protect themselves and their community from West Nile virus. There are some reports that West Nile viral infections were occurred by blood transfusion, biologic products from blood and organ transfusion.

  15. Operation of TVA reservoirs. Annual report, 1981

    SciTech Connect

    Not Available

    1984-09-01

    This report describes the operation of TVA, ALCOA, and Cumberland Basin reservoirs that were scheduled daily by Reservoir Operations Branch personnel during calendar year 1981. These include all TVA reservoirs, eight reservoirs in the Cumberland River Basin owned by the US Army, Corps of Engineers, and six reservoirs in the Tennessee River Basin owned by ALCOA. In addition, storage and flow computations include Walters Reservoir, operated by Carolina Power and Light Company; and Woods Reservoir, operated by the US Air Force. Plates are included in this report tabulating daily elevations, storage volumes, and/or average discharges for 48 reservoirs for 1981. Additional plates are included for the daily average flow in Barkley Canal, monthly and annual emptyings and water use at each lock in the Tennessee River Basin, monthly and annual capacity factors at each TVA scheduled hydro plant, combined monthly and annual storage and flows (in inches) for reservoirs above Chickamauga and Kentucky Dams, and a summary of Reservoir Operations. Tables of monthly and annual storages and flows (in inches) for the principal Tennessee River Basin tributary projects are included at the end of their respective annual operations summary. Individual plotting of midnight reservoir elevations during calendar year 1981 are included for the principal tributary storage reservoirs and Normandy Reservoir. Group charts are included showing midnight reservoir elevations for other tributary reservoirs, the Tennessee River reservoirs, and the principal Cumberland Basin reservoirs.

  16. Operation of TVA reservoirs: annual 1980

    SciTech Connect

    Not Available

    1983-10-01

    This report describes the operation of TVA, ALCOA, and Cumberland Basin reservoirs that were scheduled daily by Reservoir Operations Branch personnel during calendar year 1980. These include all TVA reservoirs, eight reservoirs in the Cumberland River Basin owned by the US Army, Corps of Engineers, and six reservoirs in the Tennessee River Basin owned by ALCOA. In addition, storage and flow computations include Walters Reservoir, operated by Carolina Power and Light Company; and Woods Reservoir, operated by the US Air Force. Plates are included in this report tabulating daily elevations, storage volumes, and/or average discharges for 48 reservoirs for 1980. Additional plates are included for the daily average flow in Barkley Canal, monthly and annual emptyings and water use at each lock in the Tennessee River Basin, monthly and annual capacity factors at each TVA scheduled hydro plant, combined monthly and annual storage and flows (in inches) for reservoirs above Chickamauga and Kentucky Dams, and a summary of Reservoir Operations. Tables of monthly and annual storage and flows (in inches) for the principal Tennessee River Basin tributary projects are included at the end of their respective annual operations summary. Individual plottings of midnight reservoir elevations are included for the principal tributary storage reservoirs and Normandy Reservoir. Group charts are included showing midnight reservoir elevations for other tributary reservoirs, the Tennessee River reservoirs, and the principal Cumberland Basin reservoirs.

  17. GeoPowering the west.

    SciTech Connect

    Hill, Roger Ray

    2004-09-01

    The U.S. Department of Energy's (DOE's) GeoPowering the West (GPW) program works with the U.S. geothermal industry, power companies, industrial and residential consumers, and federal, state, and local officials to provide technical and institutional support and limited, cost-shared funding to state-level activities. By demonstrating the benefits of geothermal energy, GPW increases state and regional awareness of opportunities to enhance local economies and strengthen our nation's energy security while minimizing environmental impact. By identifying barriers to development and working with others to eliminate them, GPW helps a state or region create a regulatory and economic environment that is more favorable for geothermal and other renewable energy development. Electricity is produced using expanding steam or very hot water from the underground reservoir to spin a conventional turbine-generator. Geothermal power plants operate at high capacity factors (70-100%), with availability factors typically greater than 95%. Geothermal plants are among the cleanest sources of electric power available. Direct use applications directly pipe hot water from geothermal resources to provide heat for industrial processes, crop drying, greenhouses, aquaculture, recreation, sidewalk snow-melting, and buildings. Geothermal district heating systems supply heat to multiple buildings through a network of pipes carrying the hot geothermal water.

  18. Geothermal Reservoir Dynamics - TOUGHREACT

    SciTech Connect

    Pruess, Karsten; Xu, Tianfu; Shan, Chao; Zhang, Yingqi; Wu,Yu-Shu; Sonnenthal, Eric; Spycher, Nicolas; Rutqvist, Jonny; Zhang,Guoxiang; Kennedy, Mack

    2005-03-15

    This project has been active for several years and has focused on developing, enhancing and applying mathematical modeling capabilities for fractured geothermal systems. The emphasis of our work has recently shifted towards enhanced geothermal systems (EGS) and hot dry rock (HDR), and FY05 is the first year that the DOE-AOP actually lists this project under Enhanced Geothermal Systems. Our overall purpose is to develop new engineering tools and a better understanding of the coupling between fluid flow, heat transfer, chemical reactions, and rock-mechanical deformation, to demonstrate new EGS technology through field applications, and to make technical information and computer programs available for field applications. The objectives of this project are to: (1) Improve fundamental understanding and engineering methods for geothermal systems, primarily focusing on EGS and HDR systems and on critical issues in geothermal systems that are difficult to produce. (2) Improve techniques for characterizing reservoir conditions and processes through new modeling and monitoring techniques based on ''active'' tracers and coupled processes. (3) Improve techniques for targeting injection towards specific engineering objectives, including maintaining and controlling injectivity, controlling non-condensable and corrosive gases, avoiding scale formation, and optimizing energy recovery. Seek opportunities for field testing and applying new technologies, and work with industrial partners and other research organizations.

  19. Age and morphodynamics of a sandy beach fronted by a macrotidal mud flat along the west coast of Korea: a lateral headland bypass model for beach-dune formation

    NASA Astrophysics Data System (ADS)

    Chang, Tae Soo; Hong, Seok Hwi; Chun, Seung Soo; Choi, Jeong-Heon

    2016-11-01

    The Dasari beach-dune system fronted by an intertidal mud flat is a typical example of numerous small beaches found both in embayments and along the open macrotidal west coast of Korea. The beach is frequently exposed to energetic wave action at high tide in winter. Although this coastal dune-sandy beach-intertidal mud flat system has previously been described, its origin and morphodynamic behavior has to date not been firmly established. To clarify these issues, elevation profiles and surficial sediment samples were collected seasonally along five monitoring transects across the tidal flat. In addition, box-cores as well as vibro- and drill-cores were acquired along the middle transect. Optically stimulated luminescence (OSL) and 14C- AMS (accelerator mass spectrometry) dating methods were applied to determine the age of the tidal flat, the beach and the dune deposits. The results show that Dasari beach is topographically composed of two distinct morphological and sedimentological sectors, comprising a high-tide sandy beach that merges seaward into an extensive low-tide tidal flat composed of mud. The transition between the two sectors is marked by a sharp break in slope and change in internal sedimentary structures. At the boundary, the subtle shoreward fining trend in mean grain size on the intertidal flat switches to a pronounced shoreward coarsening trend. Near the transition, mixing between the beach sand and the mud is observed. Another striking feature is a seasonal rotation of the beach system centered on the middle sector, with the northern sector eroding in winter and accreting in summer, and the southern sector accreting in winter and eroding in summer. The spatial grain-size pattern reveals that the beach is fed from the neighboring beach in the north by lateral headland bypassing, rather than onshore transport across the tidal flat, the intermittent lateral supply of sand explaining the seasonal rotation of the beach. Stratigraphically, the beach

  20. Age and morphodynamics of a sandy beach fronted by a macrotidal mud flat along the west coast of Korea: a lateral headland bypass model for beach-dune formation

    NASA Astrophysics Data System (ADS)

    Chang, Tae Soo; Hong, Seok Hwi; Chun, Seung Soo; Choi, Jeong-Heon

    2017-08-01

    The Dasari beach-dune system fronted by an intertidal mud flat is a typical example of numerous small beaches found both in embayments and along the open macrotidal west coast of Korea. The beach is frequently exposed to energetic wave action at high tide in winter. Although this coastal dune-sandy beach-intertidal mud flat system has previously been described, its origin and morphodynamic behavior has to date not been firmly established. To clarify these issues, elevation profiles and surficial sediment samples were collected seasonally along five monitoring transects across the tidal flat. In addition, box-cores as well as vibro- and drill-cores were acquired along the middle transect. Optically stimulated luminescence (OSL) and 14C- AMS (accelerator mass spectrometry) dating methods were applied to determine the age of the tidal flat, the beach and the dune deposits. The results show that Dasari beach is topographically composed of two distinct morphological and sedimentological sectors, comprising a high-tide sandy beach that merges seaward into an extensive low-tide tidal flat composed of mud. The transition between the two sectors is marked by a sharp break in slope and change in internal sedimentary structures. At the boundary, the subtle shoreward fining trend in mean grain size on the intertidal flat switches to a pronounced shoreward coarsening trend. Near the transition, mixing between the beach sand and the mud is observed. Another striking feature is a seasonal rotation of the beach system centered on the middle sector, with the northern sector eroding in winter and accreting in summer, and the southern sector accreting in winter and eroding in summer. The spatial grain-size pattern reveals that the beach is fed from the neighboring beach in the north by lateral headland bypassing, rather than onshore transport across the tidal flat, the intermittent lateral supply of sand explaining the seasonal rotation of the beach. Stratigraphically, the beach

  1. Source of oils in Gulf Coast Cenozoic reservoirs

    SciTech Connect

    Curtis, D.M. )

    1989-09-01

    Many Gulf Coast geologists have assumed that shales interbedded with or adjacent to the reservoir sandstones are source rocks for oils in Cenozoic reservoirs, but few source-rock quality shales have been identified in Cenozoic strata. Reservoirs and their associated shales are in thermally immature and organic-poor intervals. Based on geothermal gradient, age, and depth, it can be shown that thermally mature source rocks should be present in older slope shales beneath each producing trend. Assumptions regarding the source rock potential of the interbedded thermally immature shales derive from the fact that hydrocarbons migrated into traps soon after burial of the reservoir (early migration). Early migration from the source rock was therefore also assumed (shallow burial, early migration model). Review of the geochemical requirements for a source rock shows that geochemical constraints demand late migration from the source rock after many thousands of feet of burial (deep burial, late migration model). Geological and geochemical concepts are compatible, however, if migration out of the source rock was late (long after deposition and deep burial of the source rock) but migration into the reservoir was early (soon after shallow burial of the reservoir and trap system).

  2. Functional wettability in carbonate reservoirs

    DOE PAGES

    Brady, Patrick V.; Thyne, Geoffrey

    2016-10-11

    Oil adsorbs to carbonate reservoirs indirectly through a relatively thick separating water layer, and directly to the surface through a relatively thin intervening water layer. Whereas directly sorbed oil desorbs slowly and incompletely in response to changes in reservoir conditions, indirectly sorbed oil can be rapidly desorbed by changing the chemistry of the separating water layer. The additional recovery might be as much as 30% original oil in place (OOIP) above the ~30% OOIP recovered from carbonates through reservoir depressurization (primary production) and viscous displacement (waterflooding). Electrostatic adhesive forces are the dominant control over carbonate reservoir wettability. A surface complexationmore » model that quantifies electrostatic adhesion accurately predicts oil recovery trends for carbonates. Furthermore, the approach should therefore be useful for estimating initial wettability and designing fluids that improve oil recovery.« less

  3. Functional wettability in carbonate reservoirs

    SciTech Connect

    Brady, Patrick V.; Thyne, Geoffrey

    2016-10-11

    Oil adsorbs to carbonate reservoirs indirectly through a relatively thick separating water layer, and directly to the surface through a relatively thin intervening water layer. Whereas directly sorbed oil desorbs slowly and incompletely in response to changes in reservoir conditions, indirectly sorbed oil can be rapidly desorbed by changing the chemistry of the separating water layer. The additional recovery might be as much as 30% original oil in place (OOIP) above the ~30% OOIP recovered from carbonates through reservoir depressurization (primary production) and viscous displacement (waterflooding). Electrostatic adhesive forces are the dominant control over carbonate reservoir wettability. A surface complexation model that quantifies electrostatic adhesion accurately predicts oil recovery trends for carbonates. Furthermore, the approach should therefore be useful for estimating initial wettability and designing fluids that improve oil recovery.

  4. Fully analogue photonic reservoir computer.

    PubMed

    Duport, François; Smerieri, Anteo; Akrout, Akram; Haelterman, Marc; Massar, Serge

    2016-03-03

    Introduced a decade ago, reservoir computing is an efficient approach for signal processing. State of the art capabilities have already been demonstrated with both computer simulations and physical implementations. If photonic reservoir computing appears to be promising a solution for ultrafast nontrivial computing, all the implementations presented up to now require digital pre or post processing, which prevents them from exploiting their full potential, in particular in terms of processing speed. We address here the possibility to get rid simultaneously of both digital pre and post processing. The standalone fully analogue reservoir computer resulting from our endeavour is compared to previous experiments and only exhibits rather limited degradation of performances. Our experiment constitutes a proof of concept for standalone physical reservoir computers.

  5. Reservoir computing on the hypersphere

    NASA Astrophysics Data System (ADS)

    Andrecut, M.

    Reservoir Computing (RC) refers to a Recurrent Neural Network (RNNs) framework, frequently used for sequence learning and time series prediction. The RC system consists of a random fixed-weight RNN (the input-hidden reservoir layer) and a classifier (the hidden-output readout layer). Here, we focus on the sequence learning problem, and we explore a different approach to RC. More specifically, we remove the nonlinear neural activation function, and we consider an orthogonal reservoir acting on normalized states on the unit hypersphere. Surprisingly, our numerical results show that the system’s memory capacity exceeds the dimensionality of the reservoir, which is the upper bound for the typical RC approach based on Echo State Networks (ESNs). We also show how the proposed system can be applied to symmetric cryptography problems, and we include a numerical implementation.

  6. Reservoir evaporation in Texas, USA

    NASA Astrophysics Data System (ADS)

    Wurbs, Ralph A.; Ayala, Rolando A.

    2014-03-01

    The role of reservoir surface evaporation in river/reservoir water budgets and water management is explored using a modeling system that combines historical natural hydrology with current conditions of water resources development and management. The long-term mean evaporation from the 3415 reservoirs in the Texas water rights permit system is estimated to be 7.53 billion m3/year, which is equivalent to 61% of total agricultural or 126% of total municipal water use in the state during the year 2010. Evaporation varies with the hydrologic conditions governing reservoir surface areas and evaporation rates. Annual statewide total evaporation volumes associated with exceedance probabilities of 75%, 50%, and 25% are 7.07, 7.47, and 7.95 billion m3/year, respectively. Impacts of evaporation are greatest during extended severe droughts that govern water supply capabilities.

  7. Fully analogue photonic reservoir computer

    PubMed Central

    Duport, François; Smerieri, Anteo; Akrout, Akram; Haelterman, Marc; Massar, Serge

    2016-01-01

    Introduced a decade ago, reservoir computing is an efficient approach for signal processing. State of the art capabilities have already been demonstrated with both computer simulations and physical implementations. If photonic reservoir computing appears to be promising a solution for ultrafast nontrivial computing, all the implementations presented up to now require digital pre or post processing, which prevents them from exploiting their full potential, in particular in terms of processing speed. We address here the possibility to get rid simultaneously of both digital pre and post processing. The standalone fully analogue reservoir computer resulting from our endeavour is compared to previous experiments and only exhibits rather limited degradation of performances. Our experiment constitutes a proof of concept for standalone physical reservoir computers. PMID:26935166

  8. Cascade Reservoirs Floodwater Resources Utilization

    NASA Astrophysics Data System (ADS)

    Wang, Y.

    2015-12-01

    A reasonable floodwater resources utilization method is put forward by dynamic controlling of cascade reservoirs flood control limited level in this paper. According to the probability distribution of the beginning time of the first flood and the ending time of the final flood from July to September, the Fuzzy Statistic Analysis was used to divide the main flood season. By fitting the flood season membership functions of each period, the cascade reservoirs flood control limited water level for each period were computed according to the characteristic data of reservoirs. In terms of the benefit maximization and risk minimum principle, the reasonable combination of flood control limited water level of cascade reservoirs was put forward.

  9. Functional wettability in carbonate reservoirs

    SciTech Connect

    Brady, Patrick V.; Thyne, Geoffrey

    2016-10-11

    Oil adsorbs to carbonate reservoirs indirectly through a relatively thick separating water layer, and directly to the surface through a relatively thin intervening water layer. Whereas directly sorbed oil desorbs slowly and incompletely in response to changes in reservoir conditions, indirectly sorbed oil can be rapidly desorbed by changing the chemistry of the separating water layer. The additional recovery might be as much as 30% original oil in place (OOIP) above the ~30% OOIP recovered from carbonates through reservoir depressurization (primary production) and viscous displacement (waterflooding). Electrostatic adhesive forces are the dominant control over carbonate reservoir wettability. A surface complexation model that quantifies electr