Sample records for range colorado plateau

  1. Quaternary volcanism in the Colorado Plateau-Basin and Range transition zone: Zuni-Bandera and nearby volcanic fields (United States)

    Cascadden, Tracey Elaine

    Early (ca. 700 ka) voluminous tholeiites in the Zuni-Bandera volcanic field (ZBVF) were followed by smaller volume alkalic, transitional and tholeiitic basalts, intermittently erupted from ca. 200 ka through 3 ka. In some cases, lavas of different chemical characteristics were erupted from the same vent, or from contemporaneous clusters of vents. El Calderon cinder cone erupted magmas derived from two different sources. Early alkalic eruptions, derived from a depleted (asthenospheric) source, were followed by more voluminous tholeiitic flows derived from an enriched (lithospheric) source. The tholeiite flow erupted at ca. 80 ka during a high-amplitude excursion (possibly an aborted reversal) of the geomagnetic field, as indicated by a paleomagnetic direction with declination = 271sp° , inclination = -17sp° (N = 10, alphasb{95}=4.4sp° ,\\ kappa = 124). This tholeiite has higher Ksb2O, TiOsb2, MgO, Co, Nb, Sr, Zr and LREE contents than other ZBVF tholeiites. The Candelaria Cluster comprises four volcanoes, within a four kmsp2 area, that erupted alkalic and transitional lavas from an asthenospheric source and tholeiitic lavas from a lithospheric source. Lavas from all four vents record moderate-amplitude paleomagnetic secular variation (declination = 32sp° , inclination = 56sp° , N = 17, alphasb{95}=2.8sp° ,\\ kappa = 189) indicating eruption within a very short time span, conceivably less than 100 years. The ZBVF is located within the Basin and Range/Rio Grande rift - Colorado Plateau transition zone, where extension has thinned the crust and lithosphere with respect to the Colorado Plateau but not as much as in the more highly-extended Basin and Range. Contemporaneous eruption of magmas from different mantle sources is consistent with a model in which transition zone alkalic magmas are generated at the boundary between upwelling depleted asthenosphere and residual enriched lithosphere, and tholeiitic magmas are derived from the lithosphere. The lack of

  2. Colorado Plateau Rapid Ecoregion Assessment Data Catalog (United States)

    Bureau of Land Management, Department of the Interior — Datasets used in the analysis of the Colorado Plateau (COP) Rapid Ecoregion Assessment (REA).They can be downloaded via a layer package (lpk, similar to a zip file...

  3. The Colorado Plateau IV: shaping conservation through science and management (United States)

    Wakeling, Brian F.; Sisk, Thomas D.; van Riper, Charles


    Roughly centered on the Four Corners region of the southwestern United States, the Colorado Plateau covers some 130,000 square miles of sparsely vegetated plateaus, mesas, canyons, arches, and cliffs in Arizona, Utah, Colorado, and New Mexico. With elevations ranging from 3,000 to 14,000 feet, the natural systems found within the plateau are dramatically varied, from desert to alpine conditions. This book focuses on the integration of science and resource management issues in this unique and highly varied environment. Broken into three subsections, this volume addresses conservation biology, biophysical resources, and inventory and monitoring concerns. The chapters range in content, addressing conservation issues–past, present, and future–on the Colorado Plateau, measurement of human impacts on resources, grazing and wildland-urban interfaces, and tools and methods for monitoring habitats and species. An informative read for people interested in the conservation and natural history of the region, the book will also serve as a valuable reference for those people engaged in the management of cultural and biological resources of the Colorado Plateau, as well as scientists interested in methods and tools for land and resource management throughout the West.

  4. Deep mantle forces and the uplift of the Colorado Plateau

    Energy Technology Data Exchange (ETDEWEB)

    Moucha, R; Forte, A M; Rowley, D B; Mitrovica, J X; Simmons, N A; Grand, S P


    Since the advent of plate tectonics, it has been speculated that the northern extension of the East Pacific Rise, specifically its mantle source, has been over-ridden by the North American Plate in the last 30 Myrs. Consequently, it has also been postulated that the opening of the Gulf of California, the extension in the Basin and Range province, and the uplift of the Colorado Plateau are the resulting continental expressions of the over-ridden mantle source of the East Pacific Rise. However, only qualitative models based solely on surface observations and heuristic, simplified conceptions of mantle convection have been used in support or against this hypothesis. We introduce a quantitative model of mantle convection that reconstructs the detailed motion of a warm mantle upwelling over the last 30 Myrs and its relative advance towards the interior of the southwestern USA. The onset and evolution of the crustal uplift in the central Basin and Range province and the Colorado Plateau is determined by tracking the topographic swell due to this mantle upwelling through time. We show that (1) the extension and magmatism in the central Basin and Range province between 25 and 10 Ma coincides with the reconstructed past position of this focused upwelling, and (2) the southwestern portion of the Colorado Plateau experienced significant uplift between 10 Ma and 5 Ma that progressed towards the northeastern portion of the plateau. These uplift estimates are consistent with a young, ca. 6 Ma, Grand Canyon model and the recent commencement of mafic magmatism.

  5. Removal of pinyon-juniper woodlands on the Colorado Plateau (United States)

    Michael Peters; Neil S. Cobb


    (Please note, this is an abstract only) Pinyon-Juniper (PJ) woodland is the 3rd largest vegetation type in the United States, covering 35.5% of the Colorado Plateau, it is the largest vegetation type administered by the Bureau of Land Management (BLM) on the Colorado Plateau. These woodlands have been increasing dramatically in density and extent over the last 100...

  6. Dendroclimatic reconstructions for the southern Colorado plateau

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    Dean, J.S.; Funkhouser, G.S. [Univ. of Arizona, Tucson, AZ (United States)


    A geographical network of climate sensitive tree-ring chronologies consisting of 25 archaeological sequences and two bristlecone pine series provides the basis for high resolution reconstructions of low and high frequency climatic variability on the southern Colorado Plateau over the last 1,500 years. Qualitative and quantitative dendroclimatic analyses of these data produce annual retrodictions of yearly and seasonal precipitation and summer Palmer Drought Severity Indices for each station and reconstructions of regional scale patterns in climatic variability. These reconstructions provide detailed information on climatic fluctuations that affected biotic and human populations as well as long-term baseline data for evaluating present-day climate and estimating future climatic trends. When integrated with other measures of past environmental variability, these reconstructions specify periods of favorable and unfavorable environmental conditions that would have affected past human populations of the region. The severest degradation, which occurred between A.D. 1250 and 1450, probably was causally related to numerous cultural changes that occurred at the end of the l3th century including the Anasazi abandonment of the Four Comers area. Projecting environmental patterns that characterized the last two millennia into the future indicates potential hazards to long term uranium mill waste disposal and containment and the potential and limitations of environmental restoration.

  7. Discovery of cryptic Armillaria solidipes genotypes within the Colorado Plateau (United States)

    J. W. Hanna; N. B. Klopfenstein; M. -S. Kim; S. M. Ashiglar; A. L. Ross-Davis; G. I. McDonald


    Armillaria solidipes (= A. ostoyae) is a root-disease pathogen that causes severe losses in growth and productivity of forest trees throughout the Northern Hemisphere. This species is genetically diverse with variable disease activities across different regions of the world. In North America, A. solidipes in the Colorado Plateau exists in drier habitats and causes more...

  8. Uplift of the Colorado Plateau due to lithosphere attenuation during Laramide low-angle subduction (United States)

    Spencer, J.E.


    The Colorado Plateau is blanketed by Phanerozoic marine and nonmarine strata as young as Cretaceous that are now exposed at elevations of about 2 km. Crustal thickening due to magmatism and horizontal crustal shortening was far less than necessary to cause this uplift, which is commonly attributed to the consequences of mantle lithosphere thinning and heating. The Colorado Plateau and the midcontinent region around Iowa consist of Precambrian bedrock overlain by a similar amount of Paleozoic platformal strata, and thus both regions once had similar lithospheric buoyancy. Mesozoic sedimentation increased the crustal thickness and lithospheric buoyancy of the Colorado Plateau relative to the midcontinent region. Backstripping calculations yield elevation without these sediments and lead to a calculated elevation difference between the two areas of about 1200 m, which represents unexplained plateau uplift. Review of constraints on uplift timing finds little support for a late Cenozoic uplift age and allows early to middle Cenozoic uplift, which is consistent with uplift mechanisms related to low-angle subduction that ended in the middle Cenozoic. Finite element heat flow calculations of low-angle subduction and lithosphere attenuation, using a range of initial lithosphere thicknesses and degree of attenuation, indicate that required uplift can result from tectonic removal of about 120 km of mantle lithosphere from an initially 200-km-thick lithosphere. This allows for partial preservation of North American mantle lithosphere with its distinctive isotopic signature in some late Cenozoic volcanic rocks and is consistent with normal Pn velocities in the uppermost mantle beneath the plateau.

  9. The Colorado Plateau V: research, environmental planning, and management for collaborative conservation (United States)

    Villarreal, Miguel L.; van Riper, Carena J.; Johnson, Matthew J.; van Riper, Charles


    Roughly centered on the Four Corners region of the southwestern United States, the Colorado Plateau covers some 130,000 square miles of sparsely vegetated plateaus, mesas, canyons, arches, and cliffs in Arizona, Utah, Colorado, and New Mexico. With elevations ranging from 3,000 to 14,000 feet, the natural systems found within the plateau are dramatically varied, from desert to alpine conditions. This volume, the fifth from the University of Arizona Press and the tenth overall, focuses on adaptation of resource management and conservation to climate change and water scarcity, protecting biodiversity through restructured energy policies, ensuring wildlife habitat connectivity across barriers, building effective conservation networks, and exploring new opportunities for education and leadership in conservation science. An informative read for people interested in the conservation and natural history of the region, the book will also serve as a valuable reference for those people engaged in the management of cultural and biological resources of the Colorado Plateau, as well as scientists interested in methods and tools for land and resource management throughout the West.

  10. Summary of the mineralogy of the Colorado Plateau uranium ores (United States)

    Weeks, Alice D.; Coleman, Robert Griffin; Thompson, Mary E.


    In the Colorado Plateau uranium has been produced chiefly from very shallow mines in carnotite ores (oxidized vanadiferous uranium ores) until recent deeper mining penetrated black unoxidized ores in water-saturated rocks and extensive exploration has discovered many deposits of low to nonvanadiferous ores. The uranium ores include a wide range from highly vanadiferous and from as much as one percent to a trace of copper, and contain a small amount of iron and traces of lead, zinc, molybdenum, cobalt, nickel, silver, manganese, and other metals. Recent investigation indicates that the carnotite ores have been derived by progressive oxidation of primary (unoxidized) black ores that contain low-valent uranium and vanadium oxides and silicates. The uranium minerals, uraninite and coffinite, are associated with coalified wood or other carbonaceous material. The vanadium minerals, chiefly montroseite, roscoelite, and other vanadium silicates, occur in the interstices of the sandstone and in siltstone and clay pellets as well as associated with fossil wood. Calcite, dolomite, barite and minor amounts of sulfides, arsenides, and selenides occur in the unoxidized ore. Partially oxidized vanadiferous ore is blue black, purplish brown, or greenish black in contrast to the black or dark gray unoxidized ore. Vanadium combines with uranium to form rauvite. The excess vanadium is present in corvusite, fernandinite, melanovanadite and many other quadrivalent and quinquevalent vanadium minerals as well as in vanadium silicates. Pyrite and part or all of the calcite are replaced by iron oxides and gypsum. In oxidized vanadiferous uranium ores the uranium is fixed in the relatively insoluble minerals carnotite and tyuyamunite, and the excess vanadium commonly combines with one or more of the following: calcium, sodium, potassium, magnesium, aluminum, iron, copper, manganese, or barium, or rarely it forms the hydrated pentoxide. The relatively stable vanadium silicates are little

  11. Deep electrical structure of the Colorado Plateau as determined from magnetotelluric measurements (United States)

    Pedersen, Jens; Hermance, John F.


    Magnetotelluric measurements made on the Colorado Plateau near Farmington, New Mexico, characterize the province as consisting of conductive surficial sediments underlain by a more resistive crystalline crust down to about 28 km. Beneath this zone the average resistivity is anomalously low (13 ohm m) down to at least 130 km. On the other hand, seismic evidence indicates a crustal thickness of approximately 40 km for the interior of the plateau, with lower than normal velocities in the upper mantle. The two sets of measurements are compatible providing an electrical transition zone is present in the lower crust separating a highly resistive upper crust from more conductive mantle material below 40-km depth. Constraints on the allowable upper mantle resistivity values, when combined with the theoretical analysis of Shankland and Waff on the effects of partial melt concentrations, suggest that the bulk resistivity of the mantle is being influenced by the presence of a small degree of partial melt (a few percent by volume). Temperature estimates associated with the allowable resistivity variations lie within the range 1100°-1200°C at 50-km depth and yield a geothermal gradient over the same depth interval of 3°-4°C/km or less. A comparison with electrical data that are available in the surrounding tectonic provinces indicates that the upper mantle beneath the Colorado Plateau has resistivities at least as low as those for the Basin and Range, Rio Grande rift, and Great Plains and may in fact be substantially more conducting than any of these surrounding tectonic provinces.

  12. The role of lower-crustal hydration in the tectonic evolution of the Colorado Plateau (United States)

    Porter, Ryan; Hoisch, Thomas; Holt, William E.


    Geologists have long debated the timing and mechanism for uplift of the Colorado Plateau with numerous hypotheses proposed to explain each. We use surface wave tomography to examine the lithospheric structure of the Colorado Plateau and surrounding regions and combine these data with thermodynamic modeling to better constrain lower crustal composition, water content, and density. Our results show that about 15% ( 290 m) of the modern plateau elevation can be supported isostatically by hydration of the lower crust, which reduces the overall density of the lithosphere. Hydration of the Colorado Plateau lithosphere likely occurred due to dewatering of the Farallon slab during flat-slab subduction. Subsequent warming and extension have likely further reduced the density of the crust along the plateau margins by as much as 110 kg/m3. This is likely a result of extension encroaching into the plateau and small-scale convection occurring within the mantle surrounding the plateau, and may help explain the high topography on the margins of the plateau.

  13. Sensitivity of the Colorado Plateau to Change: Climate, Ecosystems, and Society

    Directory of Open Access Journals (Sweden)

    Susan Schwinning


    Full Text Available The Colorado Plateau is located in the interior, dry end of two moisture trajectories coming from opposite directions, which have made this region a target for unusual climate fluctuations. A multi-decadal drought event some 850 years ago may have eliminated maize cultivation by the first human settlers of the Colorado Plateau, the Fremont and Anasazi people, and contributed to the abandonment of their settlements. Even today, ranching and farming are vulnerable to drought and struggle to persist. The recent use of the Colorado Plateau primarily as rangeland has made this region less tolerant to drought due to unprecedented levels of surface disturbances that destroy biological crusts, reduce soil carbon and nitrogen stocks, and increase rates of soil erosion. The most recent drought of 2002 demonstrated the vulnerability of the Colorado Plateau in its currently depleted state and the associated costs to the local economies. New climate predictions for the southwestern United States include the possibility of a long-term shift to warmer, more arid conditions, punctuated by megadroughts not seen since medieval times. It remains to be seen whether the present-day extractive industries, aided by external subsidies, can persist in a climate regime that apparently exceeded the adaptive capacities of the Colorado Plateau's prehistoric agriculturalists.

  14. Oligocene Laccoliths on the Colorado Plateau: A Key to Understanding Cenozoic Rock Cooling and Exhumation (United States)

    Murray, K. E.; Reiners, P. W.; Thomson, S. N.


    The Colorado Plateau is an exceptional region of high elevation, extensive canyonlands, and minor crustal deformation in the North American Cordillera. Numerous low-temperature thermochronology studies have attempted to constrain the timing and rate(s) at which this enigmatic Cenozoic landscape developed. However, such studies have struggled to robustly interpret the thermal histories of the Plateau's rocks because most contain detrital crystals with diverse time-temperature histories that are partially reset, which confounds efforts to see clear thermochronologic signals of Cenozoic erosion. To overcome this challenge, we targeted sample collection from places on the Plateau where rock thermal histories were reset by Oligocene magmatism: the thermal aureoles of laccolith-cored Henry, La Sal, and Abajo mountains. There, shallow plutons (i.e., laccoliths) heated the late Paleozoic and Mesozoic sedimentary rocks ca. 26 Ma, locally resetting apatite fission track and (U-Th)/He ages so they record subsequent Miocene-Quaternary cooling. Sandstone samples from each mountain range yield single-crystal apatite He ages that vary with effective U concentration (eU). In these key samples, minimum He ages are ~5 Ma with eU 60 ppm. We model and interpret these age-eU patterns together with (1) stratigraphic constraints, (2) the timing of magmatic heating constrained by zircon U/Pb laccolith geochronology, and (3) the extent of resetting temperatures >100 ˚C by apatite fission track analysis. Results require prolonged sample residence in the apatite He partial retention zone (40-60 ˚C) from 25 to 1 km/Myr in parts of the Henry and Abajo mountains. The Plio-Pleistocene was a time of change both regionally and globally, as Colorado River base level dropped with its final integration through the Grand Canyon ca. 5.3 Ma and global climate cooling possibly enhanced erosion rates on the Plateau's high-relief mountain ranges. Ongoing work evaluates the relationship between the

  15. On the brink of change: plant responses to climate on the Colorado Plateau (United States)

    Munson, Seth M.; Belnap, Jayne; Schelz, Charles D.; Moran, Mary; Carolin, Tara W.


    The intensification of aridity due to anthropogenic climate change in the southwestern U.S. is likely to have a large impact on the growth and survival of plant species that may already be vulnerable to water stress. To make accurate predictions of plant responses to climate change, it is essential to determine the long-term dynamics of plant species associated with past climate conditions. Here we show how the plant species and functional types across a wide range of environmental conditions in Colorado Plateau national parks have changed with climate variability over the last twenty years. During this time, regional mean annual temperature increased by 0.18°C per year from 1989–1995, 0.06°C per year from 1995–2003, declined by 0.14°C from 2003–2008, and there was high interannual variability in precipitation. Non-metric multidimensional scaling of plant species at long-term monitoring sites indicated five distinct plant communities. In many of the communities, canopy cover of perennial plants was sensitive to mean annual temperature occurring in the previous year, whereas canopy cover of annual plants responded to cool season precipitation. In the perennial grasslands, there was an overall decline of C3 perennial grasses, no change of C4 perennial grasses, and an increase of shrubs with increasing temperature. In the shrublands, shrubs generally showed no change or slightly increased with increasing temperature. However, certain shrub species declined where soil and physical characteristics of a site limited water availability. In the higher elevation woodlands, Juniperus osteosperma and shrub canopy cover increased with increasing temperature, while Pinus edulis at the highest elevation sites was unresponsive to interannual temperature variability. These results from well-protected national parks highlight the importance of temperature to plant responses in a water-limited region and suggest that projected increases in aridity are likely to promote

  16. Market perceptions and opportunities for native plant production on the southern Colorado Plateau (United States)

    Donna L. Peppin; Peter Z. Fule; Janet C. Lynn; Anne L. Mottek-Lucas; Carolyn Hull Sieg


    Increases in revegetation activities have created a large demand for locally adapted native plant materials (NPM) in the southwestern United States. Currently, there is a minimal supply of local genotypes to meet this demand. We investigated the potential for the initiation of a native plant market in the southern Colorado Plateau. Through a literature search,...

  17. Dust emissions from unpaved roads on the Colorado Plateau (United States)

    Duniway, M.; Flagg, C.; Belnap, J.


    On the Colorado Plateau, elevated levels of aeolian dust have become a major land management and policy concern due to its influence on climate, weather, terrestrial ecosystem dynamics, landscape development and fertility, melting of snow and ice, air quality, and human health. Most desert soil surfaces are stabilized by plants, rocks, and/or physical or biological soil crusts, but once disturbed, sediment production from these surfaces can increase dramatically. Road development and use is a common surface disturbing activity in the region. The extent and density of roads and road networks is rapidly increasing due to continued energy exploration, infrastructure development, and off-highway recreation activities. Though it is well known that unpaved roads produce dust, the relative contribution of dust from existing roads or the implications of future road development to regional dust loading is unknown. To address this need, we have initiated a multifaceted research effort to evaluating dust emissions from unpaved roads regionally. At 34 sites arranged across various road surfaces and soil textures in southeastern Utah, we are: 1) monitoring dust emissions, local wind conditions, and vehicle traffic and 2) evaluating fugitive dust potential using a portable wind tunnel and measuring road characteristics that affect dust production. We will then 3) develop a GIS-based model that integrates results from 1 & 2 to estimate potential dust contributions from current and future scenarios of regional road development. Passive, horizontal sediment traps were installed at three distances downwind from the road edge. One control trap was placed upwind of the samplers to account for local, non-road dust emissions. An electronic vehicle counter and anemometer were also installed at monitoring sites. Dust samples were collected every three months at fixed heights, 15 cm up to 100 cm above the soil surface, from March 2010 to the present. Threshold friction velocities (TFV

  18. Coal fields and outlines of coal-bearing strata in the Colorado Plateau coal assessment study area (cpcf*g) (United States)

    U.S. Geological Survey, Department of the Interior — These are shapefiles and ARC/INFO coverages of coal fields and coal-bearing formations in the Colorado Plateau. These GIS layers were created by combining numerous...

  19. Coal-mine production history from 1984 through 1995 in the Colorado Plateau coal assessment study area (cpmphg) (United States)

    U.S. Geological Survey, Department of the Interior — This is a point coverage containing 12 years (1984 through 1995) of coal mining history in the Colorado Plateau coal assessment study area. This layer was derived...

  20. Dryland feedbacks to climatic change: Results from a climate manipulation experiment on the Colorado Plateau (United States)

    Reed, S.; Belnap, J.; Ferrenberg, S.; Wertin, T. M.; Darrouzet-Nardi, A.; Tucker, C.; Rutherford, W. A.


    Arid and semiarid ecosystems cover ~40% of Earth's terrestrial surface and make up ~35% of the U.S., yet we know surprisingly little about how climate change will affect these widespread landscapes. Like many dryland regions, the Colorado Plateau in the southwestern U.S. is predicted to experience climate change as elevated temperature and altered timing and amount of annual precipitation. We are using a long-term (>10 yr) factorial warming and supplemental rainfall experiment on the Colorado Plateau to explore how predicted changes in climate will affect vascular plant and biological soil crust community composition, biogeochemical cycling, and energy balance (biocrusts are a surface soil community of moss, lichen, and cyanobacteria that can make up as much as 70% of the living cover in drylands). While some of the responses we have observed were expected, many of the results are surprising. For example, we documented biocrust community composition shifts in response to altered climate that were significantly faster and more dramatic than considered likely for these soil communities that typically change over decadal and centennial timescales. Further, while we continue to observe important climate change effects on carbon cycling - including reduced net photosynthesis in vascular plants, increased CO2 losses from biocrust soils during some seasons, and changes to the interactions between water and carbon cycles - we have also found marked treatment effects on the albedo and spectral signatures of dryland soils. In addition to demonstrating the effects of these treatments, the strong relationships we observed in our experiments between biota and climate provide a quantitative framework for improving our representation of dryland responses to climate change. In this talk we will cover a range of datasets that, taken together, show: (1) large climate-driven changes to dryland biogeochemical cycling may be the result of both effects on existing communities, as well

  1. The Boulder Creek Batholith, Front Range, Colorado (United States)

    Gable, Dolores J.


    The Boulder Creek batholith is the best known of several large Precambrian batholiths of similar rock composition that crop out across central Colorado. The rocks in the batholith belong to the calc-alkaline series and range in composition from granodiorite through quartz diorite (tonalite) to gneissic aplite. Two rock types dominate': the Boulder Creek Granodiorite, the major rock unit, and a more leucocratic and slightly younger unit herein named Twin Spruce Quartz Monzonite. Besides mafic inclusions, which occur mainly in hornblende-bearing phases of the Boulder Creek Granodiorite, there are cogenetic older and younger lenses, dikes, and small plutons of hornblende diorite, hornblendite, gabbro, and pyroxenite. Pyroxenite is not found in the batholith. The Boulder Creek Granodiorite in the batholith represents essentially two contemporaneous magmas, a northern body occurring in the Gold Hill and Boulder quadrangles and a larger southern body exposed in the Blackhawk and the greater parts of the Tungsten and Eldorado Springs quadrangles. The two bodies are chemically and mineralogically distinct. The northern body is richer in CaO and poorer in K2O, is more mafic, and has a larger percentage of plagioclase than the southern body. A crude sequence of rock types occurs from west to east in the batholith accompanied by a change in plagioclase composition from calcic plagioclase on the west to sodic on the east. Ore minerals tend to decrease, and the ratio potassium feldspar:plagioclase increases inward from the western contact of the batholith, indicating that the Boulder Creek batholith is similar to granodiorite batholiths the world over. Emplacement of the Boulder Creek batholith was contemporaneous with plastic deformation and high-grade regional metamorphism that folded the country rock and the batholith contact along west-northwest and north-northwest axes. Also, smaller satellitic granodiorite bodies tend to conform to the trends of foliation and fold axes in

  2. Study of radioactive equilibrium in Carnotite ores of the Colorado Plateau (United States)

    Stieff, L.R.; Girhard, M.N.; Stern, T.W.


    The purpose of this study was to determine the age of Colorado Plateau carnotite. In addition to quantitative analyses of uranium and lead, the radium-uranium equilibrium of each sample was studied. Of the 12 samples studied, 10 are deficient in radium. If a minimum age of 130 million years is chosen for the enclosing sediments, 11 samples are deficient in lead. This deficiency may be explained by (1) leaching of lead or (2) assuming too great an age. Three samples, chosen for lead-isotope analysis, have Pb207/Pb206

  3. Documented quaternary climate change on the Colorado Plateau: 40,000 YR B.P.-present

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    Agenbroad, L.D.; Mead, J.I. [Northern Arizona Univ., Flagstaff, AZ (United States)


    Ten years of interdisciplinary research on the Colorado Plateau have produced numerous, complimentary data sets documenting environmental change over the past 40,000 years. Radiocarbon controlled chronologies allow the correlation of multiple data sets, providing an increasingly broad spectrum of environmental changes within this interval. Data sets include documentation of the presence of extinct fauna; discovery and analyses of dung deposits from extinct Pleistocene fauna; packrat midden studies; insect analyses; snail analyses; and alluvial chronologies. The results presented will be considered preliminary, as we have on-going field and laboratory studies.

  4. Membership in voluntary organizations on the Colorado Plateau: A reexamination of the technical information quandary (United States)

    Cline, K.; Lamb, B.L.


    Many scholars note the increasing desire of the public to be involved in the policy process. Others observe, however, that public participation in governance is declining. One possible explanation for this is that people do not know the technical and scientific language that is frequently used in these decision processes. Citizens simply lack the information to participate in a meaningful way. This is what is known as the “technical information quandary” (i.e., how citizen desires for increased participation can be balanced against the increasingly technical nature of public policy). Research on public participation suggests membership in voluntary associations or organizations is positively associated with higher levels of technical policy knowledge. Recreation management on the Colorado Plateau provides an excellent opportunity to examine the relationship between membership in voluntary organizations and the level of policy knowledge. In 1998, we surveyed the public living on the Colorado Plateau to ascertain their level of knowledge of technical terms and their level of participation in voluntary organizations. We found that a variety of factors were related to people's membership in these organizations. In particular, our findings indicate that those with higher levels of knowledge were significantly more likely to be members of voluntary organizations and that this knowledge was most likely to come from the organizations. These findings have important implications for environmental managers, as well as for the voluntary organizations themselves.

  5. Sources of the elements in the sandstone-type uranium deposits of the Colorado Plateau (United States)

    Shoemaker, Eugene M.; Newman, W.L.; Miesch, A.T.


    Sandstone-type uranium deposits of the Colorado Plateau are epigenetic. Certain elements have been added locally to the sandstone host to form the deposits; the added fraction of each element in the deposits is call extrinsic to distinguish it from the part present in the original unmineralized host. The principal extrinsic components, in their approximate order of abundance, are vanadium, iron magnesium, uranium, sulfur, arsenic, copper, lead, molbedenum, selenium, cobalt, and nickel. At lest six possible sources of the extrinsic components of the uranium deposits may be considered reasonably likely: 1) the sandstone beds enclosing the uranium deposits, 2) the marine Mancos shales of Cretaceous ages, 3) bentonitic shales of Jurassic and Triassic age, 4) petroliferous rocks of Pennsylvanian age, 5) Precambrian crystalline rocks underlying the Colorado Plateau, and 6) magmatic reservoirs of latest Cretaceous or Tertiary age. If the major source of some of the elements of external to the sandstone beds enclosing the deposits, it is likely that several sources have contributed to some if not most of the extrinsic components and that the importance of the various sources differs from one component to the next. Precambrian crystalline rocks are considered the most likely major source of the extrinsic uranium in the deposits.

  6. Characterization and possible origins of isolated douglas fir stands on the Colorado Plateau

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    Spence, J.R. [National Park Service, Page, AZ (United States)


    The floristic composition of several isolated stands of Pseudotsuga menziesii on the Colorado Plateau is compared. All occurred between 1700-2000 meters, which was about 300-500 meters below typical lower limits for the species. Most stands showed evidence of reproduction and recruitment. A small widespread group of species existed that was common to all stands, but beta diversity was high. A preliminary analysis of possible origins of the stands suggested that they are relictual from the late Wisconsin or early Holocene. Bird-dispersed species were less prevalent than expected compared with existing high elevation conifer forests. These stands represent important resources for Quaternary research, but are extremely vulnerable to human-caused disturbances. It is recommended that they be provided protection from disturbance through appropriate management activities of the various land management agencies.

  7. Modeling the cliff retreat response to base-level change in layered rocks, Colorado Plateau, USA (United States)

    Ward, D.; Sheehan, C.


    The retreat of cliffs is an important mode of erosion in layered rocks of variable strength. For example, the iconic Colorado Plateau landscapes of Grand Canyon, Canyonlands, and Monument Valley owe their unique forms to this process. These landscapes are the end result of incision by trunk streams followed by cliff retreat. Local interactions between stochastic rockfall and first-order channels draining a cliff regulate the cliff retreat response to a base-level fall. However, nonlinear transport dynamics, steep slopes, and variable rock strength challenge the modeling of landscape evolution in these settings. Here, we employ structure-from-motion photogrammetry to generate high-resolution DTMs of a natural experiment site on the Colorado Plateau. The site features a simple, sandstone-over-shale stratigraphy with a continuous gradient in cliffband height and evidence for an ongoing transient response to base level fall. The terrain data inform a high-resolution (dx=5 m), 2D numerical model of cliffband erosion. The model simulates the interaction of three primary processes: fluvial erosion and sediment transport; hillslope transport of regolith, including shallow landsliding; and rockfall from resistant units. Crucially, the model allows us to modify stratigraphy arbitrarily to examine the landscape response to parameters such as thickness, spacing, and dip of resistant units. Results indicate that the contrast in fluvial erodibility sets the pattern of emergence of cliffs as a resistant layer is exhumed, while the difference in weathering rates across rock types sets the rate at which cliffs emerge. Once rockfall begins, erosion rates are modified by the thickness of the resistant layer, which sets the volume of rockfall debris reaching the channels below the cliff. The modeling highlights the need for process-based understanding of the conditions for cliff failure by rockfall and redistribution of the debris in very steep, rapidly-eroding landscapes.

  8. Nitrogen Eutrophication on the Colorado Plateau: Using Biological Indicators to Detect Nutrient Enrichment in the Grand Canyon Region (United States)

    Kenkel, J. A.; Johnson, N.; Hultine, K. R.; Sesnie, S.; Sisk, T.


    Human activities have more than doubled the availability of biologically reactive forms of nitrogen (N) since the industrial and agricultural revolutions. Though N is an important plant nutrient, increased deposition initiates a cascade of deleterious effects including ecosystem acidification, biodiversity loss, and increased smog and haze. Atmospheric pollution continues to threaten the air quality of the 16 Class 1 Wilderness areas on the Colorado Plateau, including Grand Canyon National Park (GCNP). However, the ecological impacts of N deposition in these historically N-limited, nutrient sensitive arid regions, are little- known. Here, we report baseline atmospheric and terrestrial responses to anthropogenic N deposition derived from vehicular exhaust in GCNP and long-range deposition from a local coal-fired power plant, the Navajo Generating Station (NGS). We used passive air samplers, natural abundance δ15N stable isotope analysis, and nutrient analysis to observe N patterns in air, soils, and pinyon pine (Pinus edulis) foliage. In GCNP, samples were collected from ten sites over an eight-month period in areas of projected low to high vehicular N deposition (i.e. distance from primary roadways). On the Paria Plateau, northeast of GCNP and in close proximity to the NGS, samples were collected along a distance gradient from the NGS, across the Plateau. In both study areas, atmospheric deposition, as well as soil and pine- needle nutrient concentrations show significant negative relationships with increased distance from N-source (p<0.05). In heavily trafficked sites of GCNP, atmospheric nitrogen oxides (NOx) were 65% lower at 30m compared to the roadside. Likewise, on the Paria, NOx were 54% lower at 50km compared to 25km from NGS (p<0.01; R2 =0.87, for GCNP and the Paria, respectively). In GCNP, soil δ15N, and pinyon needle δ15N decrease significantly 30m from the roadside (18%, F= 4.07, p<0.05; 40%, F=4.34, p<0.05). On the Paria Plateau, soil δ15N, C

  9. Screening for contaminants of emerging concern in Northern Colorado Plateau Network waters: 2015 surface-water data (United States)

    Weissinger, R; Battaglin, William A.; Bradley, Paul M.


    In 2015, as part of an on-going screening program for contaminants of emerging concern (CECs) in conjunction with the Environmental Protection Agency (EPA) Region 8, surface waters at 18 locations in or near seven national park units within the Northern Colorado Plateau Network (NCPN) were sampled for pesticides and pesticide degradation products, pharmaceuticals and personal care products, hormones, organic-wastewater-indictor chemicals, and nutrients. Most sites were sampled in spring (May or June) and fall (September).


    Olsen, P. E.; Kent, D. V.; Mundil, R.; Irmis, R.; Geissman, J. W.; Martz, J.; Parker, W.


    The proposed Colorado Plateau Coring Project (CPCP) is an interdisciplinary, multi-institutional coring project designed to recover continuous core through mostly continental strata spanning ~100 million years of the Triassic and Jurassic. Its principal purpose is to tie the incredibly rich faunas, floras, and environmental record of this interval to a rigorously developed timescale and thus to biotic, environmental, and tectonic events at a global-scale. The overall strategy involves 3 long cores (~1000 m) and 2 shorter cores (300-500 m) intended to recover the full expression of the critical early Mesozoic transitions in clear superposition. The cores would span from the base of the Moenkopi to the top of the Morrison formations with sufficient overlap to splice the sections together without gaps and assess lateral facies variations, thickness changes, and stratigraphic completeness. The initial phase of the CPCP, currently under review, is a ~500 m core at Petrified Forest National Park (PFNP) that will recover virtually the entire pre-Owl Rock Mb. of the Late Triassic age Chinle and underlying Early-Middle Triassic age Moenkopi formations. Despite excellent outcrop and a long and distinguished history of study, striking ambiguities exist in local correlation, the temporal duration and resolution of biotic events, global correlations, and the paleolatitudinal position of the region that prevent tests of major competing climatic, biotic, and tectonic hypotheses of global significance. For example, correlations of existing paleomagnetic polarity data for the Chinle of PFNP (1) with the Newark basin astronomically tuned geomagnetic polarity timescale are consistent with new U-Pb dates from reworked volcanics in the Chinle, and result in three sets of implied hypotheses. First, most or all of the Chinle Fm. is Norian and younger in age (< ~ 220 Ma). Second, the supposed Carnian-Norian boundary in the Chinle is actually a late middle Norian extinction that may

  11. Polysaccharide Degradation Capability of Actinomycetales Soil Isolates from a Semiarid Grassland of the Colorado Plateau. (United States)

    Yeager, Chris M; Gallegos-Graves, La Verne; Dunbar, John; Hesse, Cedar N; Daligault, Hajnalka; Kuske, Cheryl R


    Among the bacteria, members of the order Actinomycetales are considered quintessential degraders of complex polysaccharides in soils. However, studies examining complex polysaccharide degradation by Actinomycetales (other than Streptomyces spp.) in soils are limited. Here, we examine the lignocellulolytic and chitinolytic potential of 112 Actinomycetales strains, encompassing 13 families, isolated from a semiarid grassland of the Colorado Plateau in Utah. Members of the Streptomycetaceae , Pseudonocardiaceae , Micromonosporaceae , and Promicromonosporaceae families exhibited robust activity against carboxymethyl cellulose, xylan, chitin, and pectin substrates (except for low/no pectinase activity by the Micromonosporaceae ). When incubated in a hydrated mixture of blended Stipa and Hilaria grass biomass over a 5-week period, Streptomyces and Saccharothrix (a member of the Pseudonocardiaceae ) isolates produced high levels of extracellular enzyme activity, such as endo- and exocellulase, glucosidase, endo- and exoxylosidase, and arabinofuranosidase. These characteristics make them well suited to degrade the cellulose and hemicellulose components of grass cell walls. On the basis of the polysaccharide degradation profiles of the isolates, relative abundance of Actinomycetales sequences in 16S rRNA gene surveys of Colorado Plateau soils, and analysis of genes coding for polysaccharide-degrading enzymes among 237 Actinomycetales genomes in the CAZy database and 5 genomes from our isolates, we posit that Streptomyces spp. and select members of the Pseudonocardiaceae and Micromonosporaceae likely play an important role in the degradation of hemicellulose, cellulose, and chitin substances in dryland soils. IMPORTANCE Shifts in the relative abundance of Actinomycetales taxa have been observed in soil microbial community surveys during large, manipulated climate change field studies. However, our limited understanding of the ecophysiology of diverse Actinomycetales taxa in


    Energy Technology Data Exchange (ETDEWEB)

    R.G. Allis; J. Moore; S. White


    The six coal-fired power plants located in the Colorado Plateau and southern Rocky Mountain region of the U.S. produce 100 million tons of CO{sub 2} per year. Thick sequences of collocated sedimentary rocks represent potential sites for sequestration of the CO{sub 2}. Field and laboratory investigations of naturally occurring CO{sub 2}-reservoirs are being conducted to determine the characteristics of potential seal and reservoir units and the extent of the interactions that occur between the host rocks and the CO{sub 2} charged fluids. The results are being incorporated into a series of two-dimensional numerical models that represent the major chemical and physical processes induced by injection. During reporting period covered here (March 30 to June 30, 2003), the main achievements were: Presentation of three papers at the Second Annual Conference on Carbon Sequestration (May 5-8, Alexandria, Virginia); Presentation of a poster at the American Association of Petroleum Geologists meeting; Co-PI organized and chaired a special session on Geologic Carbon Dioxide Sequestration at the American Association of Petroleum Geologists annual convention in Salt Lake City (May 12-15).

  13. Responses of wind erosion to climate-induced vegetation changes on the Colorado Plateau (United States)

    Munson, Seth M.; Belnap, Jayne; Okin, Gregory S.


    Projected increases in aridity throughout the southwestern United States due to anthropogenic climate change will likely cause reductions in perennial vegetation cover, which leaves soil surfaces exposed to erosion. Accelerated rates of dust emission from wind erosion have large implications for ecosystems and human well-being, yet there is poor understanding of the sources and magnitude of dust emission in a hotter and drier climate. Here we use a two-stage approach to compare the susceptibility of grasslands and three different shrublands to wind erosion on the Colorado Plateau and demonstrate how climate can indirectly moderate the magnitude of aeolian sediment flux through different responses of dominant plants in these communities. First, using results from 20 y of vegetation monitoring, we found perennial grass cover in grasslands declined with increasing mean annual temperature in the previous year, whereas shrub cover in shrublands either showed no change or declined as temperature increased, depending on the species. Second, we used these vegetation monitoring results and measurements of soil stability as inputs into a field-validated wind erosion model and found that declines in perennial vegetation cover coupled with disturbance to biological soil crust resulted in an exponential increase in modeled aeolian sediment flux. Thus the effects of increased temperature on perennial plant cover and the correlation of declining plant cover with increased aeolian flux strongly suggest that sustained drought conditions across the southwest will accelerate the likelihood of dust production in the future on disturbed soil surfaces.

  14. Quantifying methane emissions and sources in the Colorado Front Range (United States)

    Hughes, S.; Townsend-Small, A.; Schroeder, J.; Blake, N. J.; Blake, D. R.


    Methane is a powerful greenhouse gas and is relatively constant throughout the atmosphere, at 1.8 ppmv. This value, however, is increasing primarily due to anthropogenic sources, including agriculture and natural gas extraction. Here we present atmospheric methane fluxes measured during the Front Range Air Pollution and Photochemistry Experiment (FRAPPE) in July - August 2014 in the Colorado Front Range on the NCAR C-130. During this campaign 775 advanced whole air samples (AWAS) were collected onboard the aircraft and 248 samples were collected on the ground in order to quantify and evaluate air pollution sources. Methane concentrations were measured continuously aboard the aircraft using cavity ringdown spectroscopy. Major sources of methane in this region are oil and natural gas extraction and distribution, landfills, and cattle feed lots. In order to assess the impact of methane emissions on this area, methane flux was evaluated by comparing upwind and downwind concentrations where significant enhancements were observed downwind. We also present information from other hydrocarbons measured in canisters to attribute methane emissions to urban, agricultural, and oil and gas sources. The state of Colorado recently enacted legislation to reduce emissions of hydrocarbons from oil and gas facilities and our measurements will provide a preliminary estimate of whether these regulations are effective.

  15. Wildfire risk transmission in the Colorado Front Range, USA. (United States)

    Haas, Jessica R; Calkin, David E; Thompson, Matthew P


    Wildfires are a global phenomenon that in some circumstances can result in human casualties, economic loss, and ecosystem service degradation. In this article we spatially identify wildfire risk transmission pathways and locate the areas of highest exposure of human populations to wildland fires under severe, but not uncommon, weather events. We quantify varying levels of exposure in terms of population potentially affected and tie the exposure back to the spatial source of the risk for the Front Range of Colorado, USA. We use probabilistic fire simulation modeling to address where fire ignitions are most likely to cause the highest impact to human communities, and to explore the role that various landowners play in that transmission of risk. Our results indicated that, given an ignition and the right fire weather conditions, large areas along the Front Range in Colorado could be exposed to wildfires with high potential to impact human populations, and that overall private ignitions have the potential to impact more people than federal ignitions. These results can be used to identify high-priority areas for wildfire risk mitigation using various mitigation tools. © 2014 Society for Risk Analysis Published 2014. This article is a U.S. government work and is in the public domain for the USA.

  16. Absolute stress measurements at the rangely anticline, Northwestern Colorado (United States)

    de la Cruz, R. V.; Raleigh, C.B.


    Five different methods of measuring absolute state of stress in rocks in situ were used at sites near Rangely, Colorado, and the results compared. For near-surface measurements, overcoring of the borehole-deformation gage is the most convenient and rapid means of obtaining reliable values for the magnitude and direction of the state of stress in rocks in situ. The magnitudes and directions of the principal stresses are compared to the geologic features of the different areas of measurement. The in situ stresses are consistent in orientation with the stress direction inferred from the earthquake focal-plane solutions and existing joint patterns but inconsistent with stress directions likely to have produced the Rangely anticline. ?? 1972.

  17. Apatite 4He/3He thermochronometry evidence for an ancient Grand Canyon, Colorado Plateau, USA (United States)

    Flowers, R. M.; Farley, K. A.


    The very existence of Grand Canyon inspires questions about why canyons are carved, how drainage systems and landscapes evolve, and how these processes relate to the elevation gain of plateaus. Yet when and why Grand Canyon was carved have been extraordinarily controversial for more than 150 years. Over the last several decades, the dominant view for the origin of the canyon is one of rapid incision at 5-6 Ma, when detritus derived from the upstream reaches of the Colorado River system appeared in Grand Wash Trough at the Colorado River's western exit from the Colorado Plateau. The absence of such diagnostic deposits prior to 6 Ma has been used to argue that Grand Canyon was not yet excavated (e.g., Karlstrom et al., 2008). However, a variety of data hint at a more ancient age for part or all of the canyon, and it has been proposed that a smaller drainage basin in largely carbonate lithologies could explain the absence of pre-6 Ma Colorado River clastics in Grand Wash Trough even if a significant Grand Canyon were present. Most recently, apatite (U-Th)/He (AHe) thermochronometry data from western Grand Canyon were used to infer excavation of this area to within several hundred meters of its modern depth by ca. 70 Ma (Wernicke, 2011), an interpretation in direct conflict with the young canyon model. The unexpected implications of the initial Grand Canyon AHe work motivated the apatite 4He/3He and U-Th zonation study presented here. Apatite 4He/3He thermochronometry provides information about the spatial distribution of radiogenic 4He in an apatite crystal that can better constrain a sample's cooling history. A key premise of AHe and 4He/3He spectra interpretation is that the He kinetic model used is accurate. We first investigate whether differing 4He/3He spectra for apatites of variable AHe date, radiation damage, and U-Th zonation from eastern Grand Canyon yield mutually consistent thermal history results using the RDAAM kinetic model, which must be true if the

  18. Reactive Multiphase behavior of CO2 in Saline Aquifers beneath the Colorado Plateau

    Energy Technology Data Exchange (ETDEWEB)

    R. G. Allis; J. Moore; S. White


    Gas reservoirs developed within the Colorado Plateau and Southern Rocky Mountains region are natural laboratories for studying the factors that promote long-term storage of CO{sub 2}. They also provide sites for storing additional CO{sub 2} if it can be separated from the flue gases of coal-fired power plants in this part of the U.S.A. These natural reservoirs are developed primarily in sandstones and dolomites; shales, mudstones and anhydrite form seals. In many fields, stacked reservoirs are present, indicating that the gas has migrated up through the section. There are also geologically young travertine deposits at the surface, and CO{sub 2}-charged groundwater and springs in the vicinity of known CO{sub 2} occurrences. These near-surface geological and hydrological features also provide examples of the environmental effects of leakage of CO{sub 2} from reservoirs, and justify further study. During reporting period covered here (the second quarter of Year 2 of the project, i.e. January 1-March 31, 2002), the main achievements were: (1) Field trips to the central Utah and eastern Arizona travertine areas to collect data and water samples to support study of surface CO{sub 2}-rich fluid leakage in these two areas. (2) Partial completion of a manuscript on natural analogues CO{sub 2} leakage from subsurface reservoirs. The remaining section on the chemistry of the fluids is in progress. (3) Improvements to CHEMTOUGH code to incorporate kinetic effects on reaction progress. (4) Submission of two abstracts (based on the above work) to the topical session at the upcoming GSA meeting in Denver titled ''Experimental, Field, and Modeling Studies of Geological Carbon Sequestration''. (5) Submission of paper to upcoming GGHT-6 conference in Kyoto. Co-PI S. White will attend this conference, and will also be involved in three other papers.

  19. Riparian ecosystem consequences of water redistribution along the Colorado Front Range (United States)

    John D. Wiener; Kathleen A. Dwire; Susan K. Skagen; Robert R. Crifasi; David Yates


    Water has shaped the American West. Nowhere is this more evident than along the Front Range of Colorado. At the west end of the famous Great Plains rainfall gradient, the Front Range extends most of the length of Colorado and is one of the fastest growing metropolitan regions in the nation. Annual precipitation along the Front Range averages about 16 inches, and...

  20. The Colorado Front Range Ecosystem Management Research Project: Accomplishments to date (United States)

    Brian Kent; Wayne D. Shepperd; Deborah J. Shields


    This article briefly describes the goals and objectives for the Colorado Front Range Ecosystem Management Project (FREM). Research under this project has addressed both biophysical and human dimensions problems relating to ecosystem management in the Colorado Front Range. Results of completed work are described, and the status of the ongoing demonstration project at...

  1. Spatial and Temporal Variability of Fugitive Dust Flux from Colorado Plateau Landscapes (United States)

    Flagg, C.; Neff, J.; Reynolds, R. L.; Belnap, J.


    C. Flagg, J.C. Neff, R.L. Reynolds, J. Belnap Aeolian dust can influence nutrient availability, soil fertility, plant interactions, and water-holding capacity. Vegetation, ground cover, land-use, and climate patterns affect dust flux in different ways. Measuring dust emission and deposition can reveal spatial and temporal patterns of dust flux, informing geologic, atmospheric, and ecological models, as well as elucidating important controls over dust emission. Previous studies have documented the effects of these characteristics on dust flux in several arid and semi-arid areas, but, to date, few have focused on Colorado Plateau landscapes. We have developed a network of 108 horizontal dust collectors spanning numerous types of ecosystems, soil types, land-use histories, and geologic bedrock and settings covering about 4400 square km across southeastern Utah. The sample archive dates to early 2008 and is currently the largest known record of fugitive dust emission for the southwestern United States. Every 3-4 months, samples were collected from the sediment traps at heights of 15 cm to one meter. Line transects were established at each collection site to measure vegetation cover, collect soil samples, and estimate surface-soil stability. Dust-flux patterns were calculated on total sediment collected over the sampling period, normalized to the size of the sediment trap and number of days in a sampling period (reported as grams m-2 day-1). Dust flux peaked during the spring months in all plant-community types, likely due to higher surface wind speeds typical of this season. Pinyon-Juniper woodland, perennial grassland, Artemisia tridentata shrubland, Coleogyne ramosissima shrubland, and Atriplex spp. shrubland averaged 6, 6.4, 11.1, 101.4, 138.1 g m-2 d-1 respectively during the spring. Dust flux was lowest during the winter period when surface wind speeds are commonly low, and snow periodically covers the soil. Pinyon-Juniper woodland, perennial grassland, Artemisia

  2. The noble gas geochemistry of natural CO 2 gas reservoirs from the Colorado Plateau and Rocky Mountain provinces, USA (United States)

    Gilfillan, Stuart M. V.; Ballentine, Chris J.; Holland, Greg; Blagburn, Dave; Lollar, Barbara Sherwood; Stevens, Scott; Schoell, Martin; Cassidy, Martin


    Identification of the source of CO 2 in natural reservoirs and development of physical models to account for the migration and interaction of this CO 2 with the groundwater is essential for developing a quantitative understanding of the long term storage potential of CO 2 in the subsurface. We present the results of 57 noble gas determinations in CO 2 rich fields (>82%) from three natural reservoirs to the east of the Colorado Plateau uplift province, USA (Bravo Dome, NM., Sheep Mountain, CO. and McCallum Dome, CO.), and from two reservoirs from within the uplift area (St. John's Dome, AZ., and McElmo Dome, CO.). We demonstrate that all fields have CO 2/ 3He ratios consistent with a dominantly magmatic source. The most recent volcanics in the province date from 8 to 10 ka and are associated with the Bravo Dome field. The oldest magmatic activity dates from 42 to 70 Ma and is associated with the McElmo Dome field, located in the tectonically stable centre of the Colorado Plateau: CO 2 can be stored within the subsurface on a millennia timescale. The manner and extent of contact of the CO 2 phase with the groundwater system is a critical parameter in using these systems as natural analogues for geological storage of anthropogenic CO 2. We show that coherent fractionation of groundwater 20Ne/ 36Ar with crustal radiogenic noble gases ( 4He, 21Ne, 40Ar) is explained by a two stage re-dissolution model: Stage 1: Magmatic CO 2 injection into the groundwater system strips dissolved air-derived noble gases (ASW) and accumulated crustal/radiogenic noble gas by CO 2/water phase partitioning. The CO 2 containing the groundwater stripped gases provides the first reservoir fluid charge. Subsequent charges of CO 2 provide no more ASW or crustal noble gases, and serve only to dilute the original ASW and crustal noble gas rich CO 2. Reservoir scale preservation of concentration gradients in ASW-derived noble gases thus provide CO 2 filling direction. This is seen in the Bravo Dome

  3. Diazotrophic Community Structure and Function in Two Successional Stages of Biological Soil Crusts from the Colorado Plateau and Chihuahuan Desert (United States)

    Yeager, C.M.; Kornosky, J.L.; Housman, D.C.; Grote, E.E.; Belnap, J.; Kuske, C.R.


    The objective of this study was to characterize the community structure and activity of N2-fixing microorganisms in mature and poorly developed biological soil crusts from both the Colorado Plateau and Chihuahuan Desert. Nitrogenase activity was approximately 10 and 2.5 times higher in mature crusts than in poorly developed crusts at the Colorado Plateau site and Chihuahuan Desert site, respectively. Analysis of nifH sequences by clone sequencing and the terminal restriction fragment length polymorphism technique indicated that the crust diazotrophic community was 80 to 90% heterocystous cyanobacteria most closely related to Nostoc spp. and that the composition of N2-fixing species did not vary significantly between the poorly developed and mature crusts at either site. In contrast, the abundance of nifH sequences was approximately 7.5 times greater (per microgram of total DNA) in mature crusts than in poorly developed crusts at a given site as measured by quantitative PCR. 16S rRNA gene clone sequencing and microscopic analysis of the cyanobacterial community within both crust types demonstrated a transition from a Microcoleus vaginatus-dominated, poorly developed crust to mature crusts harboring a greater percentage of Nostoc and Scytonema spp. We hypothesize that ecological factors, such as soil instability and water stress, may constrain the growth of N2-fixing microorganisms at our study sites and that the transition to a mature, nitrogen-producing crust initially requires bioengineering of the surface microenvironment by Microcoleus vaginatus.

  4. Beyond Colorado's Front Range - A new look at Laramide basin subsidence, sedimentation, and deformation in north-central Colorado (United States)

    Cole, James C.; Trexler, James H.; Cashman, Patricia H.; Miller, Ian M.; Shroba, Ralph R.; Cosca, Michael A.; Workman, Jeremiah B.


    This field trip highlights recent research into the Laramide uplift, erosion, and sedimentation on the western side of the northern Colorado Front Range. The Laramide history of the North Park?Middle Park basin (designated the Colorado Headwaters Basin in this paper) is distinctly different from that of the Denver basin on the eastern flank of the range. The Denver basin stratigraphy records the transition from Late Cretaceous marine shale to recessional shoreline sandstones to continental, fluvial, marsh, and coal mires environments, followed by orogenic sediments that span the K-T boundary. Upper Cretaceous and Paleogene strata in the Denver basin consist of two mega-fan complexes that are separated by a 9 million-year interval of erosion/non-deposition between about 63 and 54 Ma. In contrast, the marine shale unit on the western flank of the Front Range was deeply eroded over most of the area of the Colorado Headwaters Basin (approximately one km removed) prior to any orogenic sediment accumulation. New 40Ar-39Ar ages indicate the oldest sediments on the western flank of the Front Range were as young as about 61 Ma. They comprise the Windy Gap Volcanic Member of the Middle Park Formation, which consists of coarse, immature volcanic conglomerates derived from nearby alkalic-mafic volcanic edifices that were forming at about 65?61 Ma. Clasts of Proterozoic granite, pegmatite, and gneiss (eroded from the uplifted core of the Front Range) seem to arrive in the Colorado Headwaters Basin at different times in different places, but they become dominant in arkosic sandstones and conglomerates about one km above the base of the Colorado Headwaters Basin section. Paleocurrent trends suggest the southern end of the Colorado Headwaters Basin was structurally closed because all fluvial deposits show a northward component of transport. Lacustrine depositional environments are indicated by various sedimentological features in several sections within the >3 km of sediment

  5. Middle to late cenozoic magmatism of the southeastern Colorado plateau and central Rio Grande rift (New Mexico and Arizona, U.S.A.) : a model for continental rifting (United States)

    Baldridge, W.S.; Perry, F.V.; Vaniman, D.T.; Nealey, L.D.; Leavy, B.D.; Laughlin, A.W.; Kyle, P.; Bartov, Y.; Steinitz, G.; Gladney, E.S.


    The region of the present Rio Grande rift and southeastern Colorado Plateau underwent lithospheric extension during middle to late Cenozoic deformation affecting the entire southwestern U.S. Lithospheric mantle was disrupted, and in many regions displaced or replaced by asthenospheric mantle at depths from which basaltic magmas were derived and erupted to the surface. Study of the igneous rocks erupted or intruded during this deformation yields insights into processes of magmatism associated with extension of continental lithosphere. Magmatic rocks associated with an early (late Oligocene-early Miocene) ductile phase of extension are dominantly basaltic andesites and related, calc-alkaline intermediate to silicic derivative rocks. Mafic magmas were probably derived from isotopically "enriched" lithospheric mantle. Igneous rocks associated with a later (middle Miocene-Holocene), more brittle phase of extension include widespread basaltic rocks and localized central volcanoes of intermediate to silicic composition. Isotopic compositions of mafic rocks, which include both tholeiitic and alkalic basalts, correlate strongly with tectonic setting and lithospheric structure. Basalts erupted in areas of greatest crustal extension, such as the central and southern rift and Basin and Range province, were derived from isotopically "depleted" (correlated with "asthenospheric") mantle. Also, isotopic compositions of Pliocene to Holocene basalts are slightly more depleted than those of Miocene basalts, suggesting that subcrustal lithospheric mantle was thinned during late Miocene extension. Intermediate rocks of the central volcanoes formed by a complex combination of processes, probably dominated by fractional crystallization and by assimilation of upper and lower crust in isolated, small magma chambers. The petrologic, geochemical, and isotopic data are compatible with a model, derived first from geophysical data, whereby lithosphere is thinned beneath the central rift and

  6. Digital geospatial datasets in support of hydrologic investigations of the Colorado Front Range Infrastructure Resources Project (United States)

    U.S. Geological Survey, Department of the Interior — The U.S. Geological Survey developed this dataset as part of the Colorado Front Range Infrastructure Resources Project (FRIRP). One goal of the FRIRP was to provide...

  7. Dynamic uplift and erosion history of the Colorado Plateau: New insights from a SW-NE thermochronologic transect (United States)

    Robert, X.; Reiners, P.; Whipple, K. X.; Moucha, R.; Forte, A.


    The Colorado Plateau (CP), Paleozoic and Mesozoic sediments overlapped by Jurassic to Upper Cretaceous marine sediments is uplifted nowadays at ~1.9 km mean elevation with extremely limited crustal shortening. Deep buoyancy-driven dynamics are sometimes proposed to explain part of this uplift, but the lack of critical data and the inherently non-observable convective mantle contribute to a lack of consensus on the forces that are responsible for such features. Given recent advances in the dynamic interpretations of tomographic density variations in the mantle, [Moucha et al., 2009] simulate realistic 3D mantle convection in response to the observed mantle heterogeneity, and predict back- and forward in time the evolution of mantle flow, and thus mantle-driven dynamic surface uplift and/or subsidence. This 30 Ma retrodictions of mantle convection model carries intriguing implications for the post-Laramide evolution of the Grand Canyon (GC), the Colorado River (CR) and Lake Bidahochi that may help reconcile numerous geologic, geomorphic, and low-temperature thermochronologic data. Our analysis of the CR profile inferred from the dynamic uplift retrodictions suggests 3 major events in the post-Laramide evolution of the CP. (1) 30 to 15 Ma: Regular and homogeneous uplift (300 to 400 m) throughout the whole plateau with potential incision of the western GC with Grand Wash Cliffs tectonic relief development ~18 Ma. (2) ~15 to ~8 Ma: further uplift concentrated in the SW CP, tilting the plateau back to the E and possibly ponding the upper CR, plausibly explaining the formation of Lake Bidahochi (~190 m of observed lake sediments) and sustaining the incision of western GC. (3) ~8 to 0 Ma: NE migration of the wave of uplift, tilting the southwestern CP back to the W. It coincides with (and may have triggered) hypothesized Lake Bidahochi spillover that may have caused the dramatic post-6Ma incision of the GC. We also obtained single-grains apatite (U

  8. Presumed Multiple Metasomatism underneath the Colorado Plateau; Decoding from Chemistry and Inclusion/Lamella Mineralogy of Diverse Garnets from the Garnet Ridge, Northern Arizona (United States)

    Sato, Y.; Ogasawara, Y.


    Various garnets containing the information on mantle petrology and related metasomatism occur at the Garnet Ridge, Colorado Plateau. The origins of garnets range from deep mantle to shallow continental crust. These garnets were delivered by kimberlitic diatreme of 30 Ma (Smith et al. 2004). We have classified the garnets into 10 groups (A to J, see figure) by naked eye observation, major chemistry, minor Na-Ti-P, inclusion/lamella mineralogy. Among them, groups A to D are of mantle origin, E to G of subducted oceanic crust origin, and H to J of continental crust origin. We summarized results as in the followings. A: Cr and pyrope-rich garnet has Cr2O3(0.8-6.3 wt.%) and inclusions of Ol, Cpx, Opx, Ti-Chu/Chn and carbonates, indicating carbonated garnet lherzolites as host. Cr contents negatively correlates with Na-Ti-P contents and occurrence of exsolved Rt, Ilm and crichtonite. This indicates Cr-rich end-member is the most "primitive" mantle garnet before metasomatism. B: Pyrope-rich reddish brown garnet of peridotitic origins was subdivided into 4 subgroups (B1 to B4, see figure). Compositional range in Ca-Mg-Fe triangle expands to Fe-rich side from group A. Exsolved Na-bearing amphibole and inclusions of Ap, carbonates and fluid were identified. These indicate metasomatism of group A. C: Garnet megacryst is coarse-grained garnet (2-10 cm across) with crystal faces. This garnet has wide chemical variation plotted in the center area of Ca-Mg-Fe triangle. D: Garnet aggregate has similar chemistry of group C and is composed of several grains. Grain boundaries of garnet were recognized by Rt, Ilm and other minerals and oscillatory zonings of Ca, Mg, Fe and Na-Ti-P. Fluid inclusions of groups C and D suggest these garnets might crystalized from fluid. E: Garnet in eclogite and F: Garnet in metasomatized eclogite are xenolith samples (the Fallaron Plate origin?). Aggregate of Zo+Ab contained in group E indicates decomposed precursor lawsonite inclusion. G: Quartz

  9. Mining the Colorado Plateau: the Story of Calamity Mesa 1910-19


    Godfrey, Lisa Pitcher


    This thesis was written to outline the history of five stone houses, which have survived almost a century of mining activity. The houses are located on a barren mesa, called Calamity, in southwestern Colorado. This work was funded by the Bureau of Land Management, Department of the Interior, in order to explore the possibility of designating this site as a National Historic Site. Men and women lived and worked on this and the surrounding mesas for most of the twentieth century. The lives o...

  10. Late Quaternary eolian dust in surficial deposits of a Colorado Plateau grassland: Controls on distribution and ecologic effects (United States)

    Reynolds, R.L.; Reheis, M.C.; Neff, J.C.; Goldstein, H.; Yount, J.


    In a semi-arid, upland setting on the Colorado Plateau that is underlain by nutrient-poor Paleozoic eolian sandstone, alternating episodes of dune activity and soil formation during the late Pleistocene and Holocene have produced dominantly sandy deposits that support grass and shrub communities. These deposits also contain eolian dust, especially in paleosols. Eolian dust in these deposits is indicated by several mineralogic and chemical disparities with local bedrock, but it is most readily shown by the abundance of titaniferous magnetite in the sandy deposits that is absent in local bedrock. Magnetite and some potential plant nutrients (especially, P, K, Na, Mn, and Zn) covary positively with depth (3-4 m) in dune-crest and dune-swale settings. Magnetite abundance also correlates strongly and positively with abundances of other elements (e.g., Ti, Li, As, Th, La, and Sc) that are geochemically stable in these environments. Soil-property variations with depth can be ascribed to three primary factors: (1) shifts in local geomorphic setting; (2) accumulation of relatively high amounts of atmospheric mineral dust inputs during periods of land-surface stability; and (3) variations in dust flux and composition that are likely related to changes in dust-source regions. Shifts in geomorphic setting are revealed by large variations in soil texture and are also expressed by changes in soil chemical and magnetic properties. Variable dust inputs are indicated by both changes in dust flux and changes in relations among magnetic, chemical, and textural properties. The largest of these changes is found in sediment that spans late Pleistocene to early Holocene time. Increased dust inputs to the central Colorado Plateau during this period may have been related to desiccation and shrinkage of large lakes from about 12 to 8 ka in western North America that exposed vast surfaces capable of emitting dust. Soil properties that result from variable dust accumulation and redistribution

  11. Three distinct clades of cultured heterocystous cyanobacteria constitute the dominant N2-fixing members of biological soil crusts of the Colorado Plateau, USA (United States)

    Yeager, C.M.; Kornosky, J.L.; Morgan, R.E.; Cain, E.C.; Garcia-Pichel, F.; Housman, D.C.; Belnap, J.; Kuske, C.R.


    The identity of the numerically dominant N2-fixing bacteria in biological soil crusts of the Colorado Plateau region and two outlying areas was determined using multiple approaches, to link the environmental diversity of nifH gene sequences to cultured bacterial isolates from the regions. Of the nifH sequence-types detected in soil crusts of the Colorado Plateau, 89% (421/473) were most closely related to nifH signature sequences from cyanobacteria of the order Nostocales. N2-fixing cyanobacterial strains were cultured from crusts and their morphotypes, 16S rRNA gene and nifH gene sequences were characterized. The numerically dominant diazotrophs in the Colorado Plateau crusts fell within three clades of heterocystous cyanobacteria. Two clades are well-represented by phylogenetically and morphologically coherent strains, corresponding to the descriptions of Nostoc commune and Scytonema hyalinum, which are widely recognized as important N2-fixing components of soil crusts. A third, previously-overlooked clade was represented by a phylogenetically coherent but morphologically diverse group of strains that encompass the morphogenera Tolypothrix and Spirirestis. Many of the strains in each of these groups contained at least two nifH copies that represent different clusters in the nifH environmental survey. ?? 2007 Federation of European Microbiological Societies.

  12. Disturbance impacts on understory plant communities of the Colorado Front Range (United States)

    Paula J. Fornwalt


    Pinus ponderosa - Pseudotsuga menziesii (ponderosa pine - Douglas-fir) forests of the Colorado Front Range have experienced a range of disturbances since they were settled by European-Americans approximately 150 years ago, including settlement-era logging and domestic grazing, and more recently, wildfire. In this dissertation, I...

  13. Carbon and nitrogen fixation differ between successional stages of biological soil crusts in the Colorado Plateau and Chihuahuan Desert (United States)

    Housman, D.C.; Powers, H.H.; Collins, A.D.; Belnap, J.


    Biological soil crusts (cyanobacteria, mosses and lichens collectively) perform essential ecosystem services, including carbon (C) and nitrogen (N) fixation. Climate and land-use change are converting later successional soil crusts to early successional soil crusts with lower C and N fixation rates. To quantify the effect of such conversions on C and N dynamics in desert ecosystems we seasonally measured diurnal fixation rates in different biological soil crusts. We classified plots on the Colorado Plateau (Canyonlands) and Chihuahuan Desert (Jornada) as early (Microcoleus) or later successional (Nostoc/Scytonema or Placidium/Collema) and measured photosynthesis (Pn), nitrogenase activity (NA), and chlorophyll fluorescence (Fv/Fm) on metabolically active (moist) soil crusts. Later successional crusts typically had greater Pn, averaging 1.2-1.3-fold higher daily C fixation in Canyonlands and 2.4-2.8-fold higher in the Jornada. Later successional crusts also had greater NA, averaging 1.3-7.5-fold higher daily N fixation in Canyonlands and 1.3-25.0-fold higher in the Jornada. Mean daily Fv/Fm was also greater in later successional Canyonlands crusts during winter, and Jornada crusts during all seasons except summer. Together these findings indicate conversion of soil crusts back to early successional stages results in large reductions of C and N inputs into these ecosystems.

  14. Disturbance automated reference toolset (DART): Assessing patterns in ecological recovery from energy development on the Colorado Plateau (United States)

    Nauman, Travis; Duniway, Michael C.; Villarreal, Miguel; Poitras, Travis


    A new disturbance automated reference toolset (DART) was developed to monitor human land surface impacts using soil-type and ecological context. DART identifies reference areas with similar soils, topography, and geology; and compares the disturbance condition to the reference area condition using a quantile-based approach based on a satellite vegetation index. DART was able to represent 26–55% of variation of relative differences in bare ground and 26–41% of variation in total foliar cover when comparing sites with nearby ecological reference areas using the Soil Adjusted Total Vegetation Index (SATVI). Assessment of ecological recovery at oil and gas pads on the Colorado Plateau with DART revealed that more than half of well-pads were below the 25th percentile of reference areas. Machine learning trend analysis of poorly recovering well-pads (quantile < 0.23) had out-of-bag error rates between 37 and 40% indicating moderate association with environmental and management variables hypothesized to influence recovery. Well-pads in grasslands (median quantile [MQ] = 13%), blackbrush (Coleogyne ramosissima) shrublands (MQ = 18%), arid canyon complexes (MQ = 18%), warmer areas with more summer-dominated precipitation, and state administered areas (MQ = 12%) had low recovery rates. Results showcase the usefulness of DART for assessing discrete surface land disturbances, and highlight the need for more targeted rehabilitation efforts at oil and gas well-pads in the arid southwest US.

  15. Geophysical study of the crust and upper mantle beneath the central Rio Grande rift and adjacent Great Plains and Colorado Plateau

    Energy Technology Data Exchange (ETDEWEB)

    Ander, M.E.


    As part of the national hot dry rock (HDR) geothermal program conducted by Los Alamos Scientific Laboratory, a regional deep magnetotelluric (MT) survey of Arizona and New Mexico was performed. The main objective of the MT project was to produce a regional geoelectric contour map of the pervasive deep electrical conductor within the crust and/or upper mantle beneath the Colorado Plateau, Basin and Range Province, and Rio Grande rift. Three MT profiles cross the Jemez lineament. Preliminary one-dimensional analysis of the data suggest the lineament is associated with anomalously high electrical conductivity very shallow in the crust. An MT/audiomagnetotelluric (AMT) study of a 161 km/sup 2/ HDR prospect was performed on the Zuni Indian Reservation, New Mexico. Two-dimensional gravity modeling of a 700-km gravity profile at 34/sup 0/30'N latitude was used to study the crust and upper mantle beneath the Rio Grande rift. Several models of each of three consecutive layers were produced using all available geologic and geophysical constraints. Two short-wavelength anomalies along the gravity profile were analyzed using linear optimization techniques.

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

    Dorsey, R. J.


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

  17. The Geologic Story of Colorado's Sangre de Cristo Range (United States)

    Lindsey, David A.


    There is no record of the beginning of time in the Sangre de Cristo Range. Almost 3 billion years of Earth history are missing, but the rest is on spectacular display in this rugged mountain landscape. This is the geologic story of the Sangre de Cristo Range.

  18. Forest biomass and tree planting for fossil fuel offsets in the Colorado Front Range (United States)

    Mike A. Battaglia; Kellen Nelson; Dan Kashian; Michael G. Ryan


    This study estimates the amount of carbon available for removal in fuel reduction and reforestation treatments in montane forests of the Colorado Front Range based on site productivity, pre-treatment basal area, and planting density. Thinning dense stands will yield the greatest offsets for biomass fuel. However, this will also yield the greatest carbon losses, if the...

  19. The Colorado Plateau Coring Project: A Continuous Cored Non-Marine Record of Early Mesozoic Environmental and Biotic Change (United States)

    Irmis, Randall; Olsen, Paul; Geissman, John; Gehrels, George; Kent, Dennis; Mundil, Roland; Rasmussen, Cornelia; Giesler, Dominique; Schaller, Morgan; Kürschner, Wolfram; Parker, William; Buhedma, Hesham


    The early Mesozoic is a critical time in earth history that saw the origin of modern ecosystems set against the back-drop of mass extinction and sudden climate events in a greenhouse world. Non-marine sedimentary strata in western North America preserve a rich archive of low latitude terrestrial ecosystem and environmental change during this time. Unfortunately, frequent lateral facies changes, discontinuous outcrops, and a lack of robust geochronologic constraints make lithostratigraphic and chronostratigraphic correlation difficult, and thus prevent full integration of these paleoenvironmental and paleontologic data into a regional and global context. The Colorado Plateau Coring Project (CPCP) seeks to remedy this situation by recovering a continuous cored record of early Mesozoic sedimentary rocks from the Colorado Plateau of the western United States. CPCP Phase 1 was initiated in 2013, with NSF- and ICDP-funded drilling of Triassic units in Petrified Forest National Park, northern Arizona, U.S.A. This phase recovered a 520 m core (1A) from the northern part of the park, and a 240 m core (2B) from the southern end of the park, comprising the entire Lower-Middle Triassic Moenkopi Formation, and most of the Upper Triassic Chinle Formation. Since the conclusion of drilling, the cores have been CT scanned at the University of Texas - Austin, and split, imaged, and scanned (e.g., XRF, gamma, and magnetic susceptibility) at the University of Minnesota LacCore facility. Subsequently, at the Rutgers University Core Repository, core 1A was comprehensively sampled for paleomagnetism, zircon geochronology, petrography, palynology, and soil carbonate stable isotopes. LA-ICPMS U-Pb zircon analyses are largely complete, and CA-TIMS U-Pb zircon, paleomagnetic, petrographic, and stable isotope analyses are on-going. Initial results reveal numerous horizons with a high proportion of Late Triassic-aged primary volcanic zircons, the age of which appears to be a close

  20. Modelling the Impact of Climate Change on Soil Water Availability and Plant Community Shifts in the Colorado Plateau (United States)

    Thomas, A.; Gill, R. A.


    Climate change with an accompanying decrease in soil moisture is expected to have a significant impact on the sensitive, water-limited ecosystems of America's southwestern deserts. Already, studies have documented shifts in the distributions of competing grasses and shrubs in this region, potentially altering ecosystem function. Of particular interest is the loss of desert grasses and the expansion of desert shrubs over the past three decades. The objective of this work is to use a process-based hydrological model to extrapolate site-level measurements to assess trends in soil moisture availability that may impact plant communities in the Colorado Plateau and surrounding regions. The model, SOILWAT, simulates the daily movement of water through plant and soil layers, incorporating precipitation, interception, evaporation, infiltration between soil layers, and absorption and transpiration by plants, as well as physical site characteristics. We applied SOILWAT to 50 sites that were stratified through the northern, central, and southern regions of Ephedra viridis. We focused on E. viridis because it has displaced desert grasses in plot-scale studies. The model was driven using spatially interpolated daily weather data from the PRISM climate model over a 34-year period. We found that across all years, average soil water content in the sandy soil of the region was higher in soil layers 40-60 cm deep than in the top 20 cm, and highest in the deepest layers down to 100 cm. The consistently higher margin of water in deeper layers may indicate the vulnerability of shallow-rooted grass to increasing evaporation and an advantage to deeply-rooted shrubs such as Ephedra.

  1. Pillow basalts of the Angayucham terrane: oceanic plateau and island crust accreted to the Brooks Range (United States)

    Pallister, J.S.; Budahn, J.R.; Murchey, B.L.


    The Angayucham Mountains (north margin of the Yukon-Koyukuk province) are made up of an imbricate stack of four to eight east-west trending, steeply dipping, fault slabs composed of Paleozoic, Middle to Late Triassic, and Early Jurassic oceanic upper crustal rocks. Field relations and geochemical characteristics of the basaltic rocks suggest that the fault slabs were derived from an oceanic plateau or island setting and were emplaced onto the Brooks Range continental margin. The basalts are variably metamorphosed to prehnite-pumpellyite and low-greenschist facies. Major element analyses suggest that many are hypersthene-normative olivine tholeiites. The Triassic and Jurassic basalts are geochemically most akin to modern oceanic plateau and island basalts. Field evidence also favors an oceanic plateau or island setting. The great composite thickness of pillow basalt probably resulted from obduction faulting, but the lack of fault slabs of gabbro or peridotite suggests that obduction faults did not penetrate below oceanic layer 2, a likely occurrence if layer 2 were anomalously thick, as in the vicinity of an oceanic island. -from Authors

  2. Thermobarometry in a migmatitic terrane, northern Front Range, Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Munn, B.J.; Tracy, R.J. (Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States))


    Thermobarometric techniques were applied to migmatized rocks from the Cache La Poudre River Canyon. The dominant pelitic assemblage is grt-bt-sil-qz-pl-kfs; stromatic migmatites are abundant. The area was sampled for grt-bearing pelites and amphibolites suitable for grt-bt or grt-hb thermometry and grt-sil-pl-qz or gt-hb-pl-qz barometry. In these texturally complex rocks, garnets exhibit varying degrees of resorption with embayed edges and highly irregular crystal outlines. Garnet compositional maps show complex retrograde zoning with distinct Mn-enriched rims. Analytical points near the rims but inside the retrograde Mn-enriched zone represent compositions as close as possible to those formed at peak conditions, based on the premise that resorption of garnet during retrogression produces rims which are enriched in Mn and Fe. Compositional maps and detailed traverses were used to interpret prograde and retrograde zoning in each garnet to choose points most representative of the peak composition. The authors P-T calculations used these garnet points with matrix bt, hb and pl. Thermobarometeric calculations from outcrops in the eastern part of the canyon yield a peak T of 725 [+-] 50 C and a peak P of 7 [+-] 0.5 kbar. The higher temperature and pressure reported here are consistent with observed phase equilibria and the migmatized nature of the area, and reflect the complicated metamorphic history of the Front Range. Andalusite previously identified in this area is localized in occurrence and retrograde in origin, and is probably related to 1.4 Ga granitic plutonism or to an episode of post-peak deformation; cordierite is typically associated with andalusite in this area (Abbott, 1970). Thus far, neither cordierite nor andalusite has been observed in any of their samples from the Poudre canyon, providing evidence for higher peak P. Therefore, peak metamorphism occurred at about 7 kbar; retrograde metamorphism occurred at lower P during decompression.

  3. Reference section for the Minturn Formation (Middle Pennsylvanian), northern Sangre de Cristo Range, Custer County, Colorado (United States)

    Lindsey, D.A.; Clark, R.F.; Soulliere, S.J.


    This reference section of the Middle Pennsylvanian Minturn Formation was measured in the northern Sangre de Cristo Range; the section provides a basis for comparison with the type Minturn and with possibly equivalent strata elsewhere in southern Colorado. The name "Minturn" was first applied to strata of Middle Pennsylvanian age near the town of Minturn in central Colorado (Tweto, 1949, p. 194-228; Tweto and Lovering, 1977, p. 33–53), about 180 km north of the section described, and has been extended to strata of approximately the same age that contain marine limestones in the northern Sangre de Cristo Range (Brill, 1952; Bolyard, 1959; Scott and Taylor, 1974). The Minturn reference section continues upward into the principal reference section of the overlying Pennsylvanian and Permian Sangre de Cristo Formation (Lindsey and Schaefer, 1984), and these two sections together provide a continuous record of upper Paleozoic strata in the northern Sangre de Cristo Range.

  4. Response of biological soil crust diazotrophs to season, altered summer precipitation, and year-round increased temperature in an arid grassland of the Colorado Plateau, USA (United States)

    Yeager, Chris M.; Kuske, Cheryl R.; Carney, Travis D.; Johnson, Shannon L.; Ticknor, Lawrence O.; Belnap, Jayne


    Biological soil crusts (biocrusts), which supply significant amounts of fixed nitrogen into terrestrial ecosystems worldwide (~33Tg y-1), are likely to respond to changes in temperature and precipitation associated with climate change. Using nifH gene-based surveys, we explored variation in the diazotrophic community of biocrusts of the Colorado Plateau, USA in response to season (autumn vs. spring), as well as field manipulations that increased the frequency of small volume precipitation events and year-round soil temperature. Abundance of nifH genes in biocrusts ranged from 3×106 to 1×8 g-1 soil, and nifH from heterocystous cyanobacteria closely related to Scytonema hyalinum, Spirirestis rafaelensis, and Nostoc commune comprised >98% of the total. Although there was no apparent seasonal effect on total nifH gene abundance in the biocrusts, T-RFLP analysis revealed a strong seasonal pattern in nifH composition. Spirirestis nifH abundance was estimated to oscillate 1 to >2 orders of magnitude between autumn (low) and spring (high). A year-round increase of soil temperature (2–3°C) had little effect on the diazotroph community structure over 2 years. Altered summer precipitation had little impact on diazotroph community structure over the first 1.5years of the study, when natural background patterns across years and seasons superseded any treatment effects. However, after the second summer of treatments, nifH abundance was 2.6-fold lower in biocrusts receiving altered precipitation. Heterocystous cyanobacteria were apparently more resilient to altered precipitation than other cyanobacteria. The results demonstrate that diazotrophic community composition of biocrusts in this semi-arid grassland undergoes strong seasonal shifts and that the abundance of its dominant members decreased in response to more frequent, small volume precipitation events.

  5. Response of biological soil crust diazotrophs to season, altered summer precipitation and year-round increased temperature in an arid grassland of the Colorado Plateau, USA

    Directory of Open Access Journals (Sweden)

    Chris M Yeager


    Full Text Available Biological soil crusts (biocrusts, which supply significant amounts of fixed nitrogen into terrestrial ecosystems worldwide (~33 Tg y-1, are likely to respond to changes in temperature and precipitation associated with climate change. Using nifH gene-based surveys, we explored variation in the diazotrophic community of biocrusts of the Colorado Plateau, USA in response to season (autumn vs. spring, as well as field manipulations that increased the frequency of small-volume precipitation events and year-round soil temperature. Abundance of nifH genes in biocrusts ranged from 3x106 – 1x108 g-1 soil, and nifH from heterocystous cyanobacteria closely related to Scytonema hyalinum, Spirirestis rafaelensis, and Nostoc commune comprised > 98% of the total. Although there was no apparent seasonal effect on total nifH gene abundance in the biocrusts, T-RFLP analysis revealed a strong seasonal pattern in nifH composition. Spirirestis nifH abundance was estimated to oscillate 1 to >2 orders of magnitude between autumn (low and spring (high. A year-round increase of soil temperature (2 − 3 °C had little effect on the diazotroph community structure over 2 years. Altered summer precipitation had little impact on diazotroph community structure over the first 1.5 years of the study, when natural background patterns across years and seasons superseded any treatment effects. However, after the second summer of treatments, nifH abundance was 2.6 fold lower in biocrusts receiving altered precipitation. Heterocystous cyanobacteria were apparently more resilient to altered precipitation than other cyanobacteria. The results demonstrate that diazotrophic community composition of biocrusts in this semi-arid grassland undergoes strong seasonal shifts and that the abundance of its dominant members decreased in response to more frequent, small-volume precipitation events.

  6. Colorado

    Directory of Open Access Journals (Sweden)

    Gerardo Rodríguez Quiroz


    Full Text Available La conservación de la biodiversidad cuenta, entre sus principales mecanismos de intervención, con las áreas naturales protegidas. En el alto Golfo de California (AGC se ubica la Reser-va de la Biosfera del Alto Golfo de California y Delta del Río Colorado, en la que subsisten especies de alto valor económico, así como especies en peligro de extinción. Este último factor justificó el establecimiento de la reserva. El estudio analiza la efectividad de la Reserva del Alto Golfo como mecanismo de protección de los recursos naturales, en particular de las que están en riesgo de desaparecer, así como de comprobar si los pescadores han mejorado sus condiciones de vida tras la operación de esa área natural. La exploración se llevó a cabo mediante la aplicación de una encuesta a los pescadores. Se sugiere que es indispensable un gran esfuerzo, de autoridades y grupos organizados, para encontrar soluciones al manejo de la Reserva, a fin fijar un programa que permita la recuperación de las especies en peligro de extinción, elevar la calidad de vida de los pescadores y con ello garantizar un equilibrio entre la conservación y la sustentabilidad de la pesca y de los pescadores en el Alto Golfo de California.

  7. The Potential for Long-Term Impacts of Extreme Events in the Front Range of Colorado (United States)

    Losleben, M. V.; Caine, N.; Flanagan, C.; McKnight, D.; Monson, R.


    Extreme climatic events can trigger a cascade of events, or cause a step function change, in environmental systems that changes the balance of one or more environmental systems, such as bio-, geo-, hydro-, or chemical. They occur at all spatial, temporal, and intensity scales, some easily measurable, others more difficult. Moreover, not all extreme events have lasting environmental impacts. Whether they foreset the environmental clock or not is dependent on the particular system sensitivity in the geographic area of interest, as well as the type of event. Obviously, sufficient environmental data are necessary to detect and evaluate the potential of an extreme event to cause long-term change, and data scarcity is often a problem in the mountains of the western US. We look at the available data for five extreme events affecting the Front Range of the Colorado Rocky Mountains, and find a range of effects, suggesting that Front Range systems are more sensitive to drought than excessive moisture, and to events of longer duration. The events are defined by the surface climatic parameters of snow, rain, or temperature, and characterized by their synoptic atmospheric circulation pattern. Factors assessing the environmental impact include net ecosystem carbon dioxide exchange, alpine lake algal populations and hydrologic residence times, rock glacier temperatures, snowpack, and reservoir storage. The events are the April 15-16, 1921 record U.S. 24-hour snowfall at Silver Lake, CO, the 1981-86 upper elevation cold period in central Colorado and southern Wyoming, an anomalously high April and May 1995 snowfall, the 2002 drought, and the March 17-19, 2003 anomalously high snowfall in the South Platte and Arkansas River basins of Colorado.

  8. The Inception of the Colorado Plateau Coring Project: Filling the Triassic Geochronologic Gap and Providing a Continuous Record of Continental Environmental Change in Western Equatorial Pangea (United States)

    Geissman, J. W.; Olsen, P. E.; Kent, D. V.; Irmis, R. B.; Gehrels, G. E.; Mundil, R.; Parker, W.; Bachmann, G. H.; Kurschner, W. M.; Sha, J.


    The Triassic Period was punctuated by two of the largest Phanerozoic mass-extinctions and witnessed the evolution of elements of the modern biota and the advent of the age of dinosaurs. A rich archive of biotic and environmental changes on land for the early Mesozoic is on the Colorado Plateau, which despite over 100 years of study still remains poorly calibrated in time and poorly registered to other global records. Over 15 years ago, a diverse team of scientists began to develop the concept of a multi-phase, long term Colorado Plateau Coring Project (CPCP). Planning involved two major meetings (DOSECC/NSFICDP supported in Fall, 2007, St. George, UT; and International Continental Drilling Program (ICDP) supported in Spring, 2009, Albuquerque, NM). The National Park Service embraced the concept of Phase One drilling at Petrified Forest National Park (PFNP) in northern Arizona, which exposes one of the most famous and best studied successions of the continental Triassic on Earth, and the Phase One target was decided. Most drilling operation costs were secured from ICDP in Summer, 2010. In late 2013, following more recent NSF support, the research team, utilizing Ruen Drilling Inc., drilled a continuous ~530 m core (60o plunge) through the entire section of Triassic strata (Chinle and Moenkopi fms.) in the north end and a ~240 m core (75o plunge) in lower Chinle and all Moenkopi strata at the south end of the PFNP. Our continuous sampling will place this record in a reliable quantitative and exportable time scale, as a reference section in which magnetostratigraphic, geochronologic, environmental, and paleontologic data are registered to a common thickness scale with unambiguous superposition using pristine samples. The cores are being scanned at the High Resolution X-ray Computed Tomography Facility at UT Austin. They will be transported to the LacCore National Lacustrine Core Facility at U Minnesota, where they will be split, imaged, and scanned for several

  9. Factors controlling streambed coverage of Didymosphenia geminata in two regulated streams in the Colorado Front Range


    Miller, Matthew P; McKnight, Diane M.; Cullis, James D.; Greene, Alicia; Vietti, Kristin; Liptzin, Daniel


    Didymosphenia geminata is a stalk-forming freshwater diatom which was historically found primarily in oligotrophic lakes and streams, but has recently become a nuisance species in many lotic systems worldwide. In the last 5–8 years, D. geminata has become established in Boulder Creek and South Boulder Creek, two regulated montane streams in the Front Range of the Colorado Rocky Mountains. Factors that may influence the growth of D. geminata were monitored during the summer of 2006. D. geminat...

  10. Principles and practices for the restoration of ponderosa pine and dry mixed-conifer forests of the Colorado Front Range (United States)

    Robert N. Addington; Gregory H. Aplet; Mike A. Battaglia; Jennifer S. Briggs; Peter M. Brown; Antony S. Cheng; Yvette Dickinson; Jonas A. Feinstein; Kristen A. Pelz; Claudia M. Regan; Jim Thinnes; Rick Truex; Paula J. Fornwalt; Benjamin Gannon; Chad W. Julian; Jeffrey L. Underhill; Brett Wolk


    Wildfires have become larger and more severe over the past several decades on Colorado’s Front Range, catalyzing greater investments in forest management intended to mitigate wildfire risks. The complex ecological, social, and political context of the Front Range, however, makes forest management challenging, especially where multiple management goals including forest...

  11. Great Basin cold desert shrublands and the Desert Experimental Range (United States)

    Stanley G. Kitchen; Stephanie L. Carlson


    The Great Basin is a vast, internally drained region of the Western United States, bounded by the Sierra Nevada and southern Cascade Mountain ranges to the west and the Wasatch Mountains and western rim of the Colorado Plateau to the east. Although less discrete, northern and southern boundaries are generally defined by the drainages of the Columbia and Colorado Rivers...

  12. New insights into debris-flow hazards from an extraordinary event in the Colorado Front Range (United States)

    Coe, Jeffrey A.; Kean, Jason W.; Godt, Jonathan W.; Baum, Rex L.; Jones, Eric S.; Gochis, David; Anderson, Gregory S


    Rainfall on 9–13 September 2013 triggered at least 1,138 debris flows in a 3430 km2 area of the Colorado Front Range. The historical record reveals that the occurrence of these flows over such a large area in the interior of North America is highly unusual. Rainfall that triggered the debris flows began after ~75 mm of antecedent rain had fallen, a relatively low amount compared to other parts of the United States. Most flows were triggered in response to two intense rainfall periods, one 12.5-hour-long period on 11–12 September, and one 8-hour-long period on 12 September. The maximum 10 min. intensities during these periods were 67 and 39 mm/hr. Ninety-five percent of flows initiated in canyons and on hogbacks at elevations lower than a widespread erosion surface of low slope and relief (25°), predominantly south- and east-facing slopes with upslope contributing areas 3300 m2. Areal concentrations of debris flows revealed that colluvial soils formed on sedimentary rocks were more susceptible to flows than soils on crystalline rocks. This event should serve as an alert to government authorities, emergency responders, and residents in the Front Range and other interior continental areas with steep slopes. Widespread debris flows in these areas occur infrequently but may pose a greater risk than in areas with shorter return periods, because the public is typically unprepared for them.

  13. Potential human impacts of overlapping land-use and climate in a sensitive dryland: a case study of the Colorado Plateau, USA (United States)

    Copeland, Stella; Bradford, John B.; Duniway, Michael C.; Schuster, Rudy


    Climate and land-use interactions are likely to affect future environmental and socioeconomic conditions in drylands, which tend to be limited by water resources and prone to land degradation. We characterized the potential for interactions between land-use types and land-use and climate change in a model dryland system, the Colorado Plateau, a region with a history of climatic variability and land-use change. We analyzed the spatial and temporal trends in aridification, land-use, and recreation at the county and 10 km2 grid scales. Our results show that oil and gas development and recreation may interact due to increasing trends and overlapping areas of high intensity. Projections suggest that aridification will impact all vegetation classes, with some of the highest proportional change in the south-east. The results suggest that the rate of change and spatial pattern of land-use in the future may differ from past patterns in land-use scale and intensity.

  14. Insights into Focused Fluid Conduit Formation from Comparing Seismic Chimneys and Pipes with Field Observations of Fluid Flow Manifestations in the Colorado Plateau (United States)

    Karstens, J.; Berndt, C.


    The understanding of focused fluid flow in sedimentary basins builds on field geological observations and the interpretation of reflection seismic data, where fluid conduits manifest as anomalous amplitude patterns known as seismic chimneys or pipes. Seismic data is the most effective method for the analysis of entire fluid flow systems by constraining subsurface geometries, fluid accumulations and permeability barriers, but seismic data cannot provide information about the internal architecture, interaction with the bedrock and flow processes due to its coarse resolution. Field geological investigations of fluid conduit outcrops are capable of filling observation gaps on a sub-seismic scale and help constrain formation dynamics as well as hydraulic properties of fluid conduits and the bedrock. Here, we show that it is possible to correlate specific amplitude patterns of seismic chimneys with field observation of focused fluid conduits from the Colorado Plateau. The migrating fluids (gas, water, fluidized sediment) and their formation dynamics, which can be associated with different types of conduits (fractures, fluidizations, injections), result in distinguishable seismic signatures. These constrains improve the qualitative interpretation of seismic chimneys by adding information about migration and formation characteristics. A further integration of field geological and seismic investigation of focused fluid flow structures may help to quantify their hydraulic properties and how these evolve with time, which has important implications for the hydrocarbon prospection and the subsurface storage of wastewater and CO2.

  15. Position of the Triassic-Jurassic boundary and timing of the end-Triassic extinctions on land: Data from the Moenave Formation on the southern Colorado Plateau, USA (United States)

    Lucas, S.G.; Tanner, L.H.; Donohoo-Hurley, L.; Geissman, J.W.; Kozur, H.W.; Heckert, A.B.; Weems, R.E.


    Strata of the Moenave Formation on and adjacent to the southern Colorado Plateau in Utah-Arizona, U.S.A., represent one of the best known and most stratigraphically continuous, complete and fossiliferous terrestrial sections across the Triassic-Jurassic boundary. We present a synthesis of new biostratigraphic and magnetostratigraphic data collected from across the Moenave Formation outcrop belt, which extends from the St. George area in southwestern Utah to the Tuba City area in northern Arizona. These data include palynomorphs, conchostracans and vertebrate fossils (including footprints) and a composite polarity record based on four overlapping magnetostratigraphic sections. Placement of the Triassic-Jurassic boundary in strata of the Moenave Formation has long been imprecise and debatable, but these new data (especially the conchostracans) allow us to place the Triassic-Jurassic boundary relatively precisely in the middle part of the Whitmore Point Member of the Moenave Formation, stratigraphically well above the highest occurrence of crurotarsan body fossils or footprints. Correlation to marine sections based on this placement indicates that major terrestrial vertebrate extinctions preceded marine extinctions across the Triassic-Jurassic boundary and therefore were likely unrelated to the Central Atlantic Magmatic Province (CAMP) volcanism. ?? 2011 Elsevier B.V.

  16. Alpine debris flows triggered by a 28 July 1999 thunderstorm in the central Front Range, Colorado (United States)

    Godt, Jonathan W.; Coe, Jeffrey A.


    On 28 July 1999, about 480 alpine debris flows were triggered by an afternoon thunderstorm along the Continental Divide in Clear Creek and Summit counties in the central Front Range of Colorado. The thunderstorm produced about 43 mm of rain in 4 h, 35 mm of which fell in the first 2 h. Several debris flows triggered by the storm impacted Interstate Highway 70, U.S. Highway 6, and the Arapahoe Basin ski area. We mapped the debris flows from color aerial photography and inspected many of them in the field. Three processes initiated debris flows. The first process initiated 11% of the debris flows and involved the mobilization of shallow landslides in thick, often well vegetated, colluvium. The second process, which was responsible for 79% of the flows, was the transport of material eroded from steep unvegetated hillslopes via a system of coalescing rills. The third, which has been termed the "firehose effect," initiated 10% of the debris flows and occurred where overland flow became concentrated in steep bedrock channels and scoured debris from talus deposits and the heads of debris fans. These three processes initiated high on steep hillsides (> 30°) in catchments with small contributing areas (material along their paths.

  17. Wildfire impacts on soil-water retention in the Colorado Front Range, United States (United States)

    Ebel, Brian A.


    This work examined the plot-scale differences in soil-water retention caused by wildfire in the area of the 2010 Fourmile Canyon Fire in the Colorado Front Range, United States. We measured soil-water retention curves on intact cores and repacked samples, soil particle-size distributions, and organic matter content. Estimates were also made of plant-available water based on the soil-water retention curves. Parameters for use in soil-hydraulic property models were estimated; these parameters can be used in unsaturated flow modeling for comparing burned and unburned watersheds. The primary driver for measured differences in soil-water retention in burned and unburned soils was organic matter content and not soil-particle size distribution. The tendency for unburned south-facing soils to have greater organic matter content than unburned north-facing soils in this field area may explain why unburned south-facing soils had greater soil-water retention than unburned north-facing soils. Our results suggest that high-severity wildfire can “homogenize” soil-water retention across the landscape by erasing soil-water retention differences resulting from organic matter content, which for this site may be affected by slope aspect. This homogenization could have important implications for ecohydrology and plant succession/recovery in burned areas, which could be a factor in dictating the window of vulnerability of the landscape to flash floods and erosion that are a common consequence of wildfire.

  18. Metagenomic profiling of historic Colorado Front Range flood impact on distribution of riverine antibiotic resistance genes (United States)

    Garner, Emily; Wallace, Joshua S.; Argoty, Gustavo Arango; Wilkinson, Caitlin; Fahrenfeld, Nicole; Heath, Lenwood S.; Zhang, Liqing; Arabi, Mazdak; Aga, Diana S.; Pruden, Amy


    Record-breaking floods in September 2013 caused massive damage to homes and infrastructure across the Colorado Front Range and heavily impacted the Cache La Poudre River watershed. Given the unique nature of this watershed as a test-bed for tracking environmental pathways of antibiotic resistance gene (ARG) dissemination, we sought to determine the impact of extreme flooding on ARG reservoirs in river water and sediment. We utilized high-throughput DNA sequencing to obtain metagenomic profiles of ARGs before and after flooding, and investigated 23 antibiotics and 14 metals as putative selective agents during post-flood recovery. With 277 ARG subtypes identified across samples, total bulk water ARGs decreased following the flood but recovered to near pre-flood abundances by ten months post-flood at both a pristine site and at a site historically heavily influenced by wastewater treatment plants and animal feeding operations. Network analysis of de novo assembled sequencing reads into 52,556 scaffolds identified ARGs likely located on mobile genetic elements, with up to 11 ARGs per plasmid-associated scaffold. Bulk water bacterial phylogeny correlated with ARG profiles while sediment phylogeny varied along the river’s anthropogenic gradient. This rare flood afforded the opportunity to gain deeper insight into factors influencing the spread of ARGs in watersheds.

  19. Vertical Profiles of Ammonia in the Colorado Front Range: Impacts of Source Region and Meteorology (United States)

    Tevlin, A.; Kaushik, A.; Noone, D. C.; Ortega, J. V.; Smith, J. N.; Brophy, P.; Kirkland, J.; Link, M. F.; Farmer, D. K.; Wolfe, D. E.; Dube, W. P.; McDuffie, E. E.; Brown, S. S.; Zaragoza, J.; Fischer, E. V.; Murphy, J. G.


    Atmospheric ammonia plays an important role in aerosol particle formation and growth, as well as in nitrogen deposition to sensitive ecosystems. However, significant uncertainties are associated with the distribution and strength of emission sources, and many of the processes that control its atmospheric fate are not fully understood. The high density of agricultural and urban sources located in close proximity to more pristine mountainous areas to the west make the Colorado Front Range a unique area for studying atmospheric ammonia. The meteorology of the region, where heavy monsoon rains can be followed by rapid evaporation, can also impact surface-atmosphere partitioning of ammonia. As part of the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ), vertical profiles of ammonia were measured throughout the boundary layer aboard a moveable platform on the 300 m Boulder Atmospheric Observatory (BAO) tower. Changes in ammonia concentration and its vertical structure were driven not only by changes in wind direction and estimated source region, but also by fluctuations in surface and atmosphere water content. For example, large increases in atmospheric ammonia mixing ratios were observed following rain events. This may be explained by surface-atmosphere exchange of wet-deposited ammonia associated with rapid evaporation following the event, and likely impacts particle formation. This may also play a role in transport from ammonia-rich agricultural areas towards the mountainous regions to the west during periods of upslope flow. The vertical ammonia concentration gradients observed throughout the structured early morning boundary layer also provide insight into the possible causes of early morning spikes in ammonia - a phenomenon that has been well-documented in many other locations. A box model was used to assess the relative importance of surface emissions due to the evaporation of morning dew versus entrainment of ammonia-rich air from above the

  20. Stream power framework for predicting geomorphic change: The 2013 Colorado Front Range flood (United States)

    Yochum, Steven E.; Sholtes, Joel S.; Scott, Julian A.; Bledsoe, Brian P.


    The Colorado Front Range flood of September 2013 induced a diverse range of geomorphic changes along numerous stream corridors, providing an opportunity to assess responses to a large flood in a semiarid landscape. We defined six classes of geomorphic change related to peak unit stream power and valley confinement for 531 stream reaches over 226 km, spanning a gradient of channel scales and slope. Geomorphic change was generally driven by erosion of channel margins in confined reaches and by a combination of deposition and erosion in unconfined reaches. The magnitude of geomorphic change typically increased with unit stream power (ω), with greater responses observed in unconfined channels. Cumulative logit modeling indicated that total stream power or unit stream power, unit stream power gradient, and valley confinement are significant predictors of geomorphic response for this flood event. Based on this dataset, thresholds for geomorphic adjustment were defined. For channel slopes 230 W/m2 (16 lb/ft-s; at least 10% of the investigated sites experienced substantial channel widening) and a credible potential for avulsions, braiding, and loss of adjacent road embankments associated with ω > 480 W/m2 (33 lb/ft-s; at least 10% of the investigated sites experienced such geomorphic change). Infrequent to numerous eroded banks were very likely with ω > 700 W/m2 (48 lb/ft-s), with substantial channel widening or major geomorphic change shifting from credible to likely. Importantly, in reaches where there were large reductions in ω as the valley form shifted from confined to relatively unconfined, large amounts of deposition-induced, reach-scale geomorphic change occurred in some locations at relatively low ω. Additionally, alluvial channels with slopes > 3% had greater resistance to geomorphic change, likely caused by armoring by larger bed material and increased flow resistance from enhanced bedforms. Finally, we describe how these results can potentially be used by

  1. Ground water occurrence and contributions to streamflow in an alpine catchment, Colorado Front Range (United States)

    Clow, D.W.; Schrott, L.; Webb, R.; Campbell, D.H.; Torizzo, A.O.; Dornblaser, M.


    Ground water occurrence, movement, and its contribution to streamflow were investigated in Loch Vale, an alpine catchment in the Front Range of the Colorado Rocky Mountains. Hydrogeomorphologic mapping, seismic refraction measurements, and porosity and permeability estimates indicate that talus slopes are the primary ground water reservoir, with a maximum storage capacity that is equal to, or greater than, total annual discharge from the basin (5.4 ± 0.8 × 106 m3). Although snowmelt and glacial melt provide the majority of annual water flux to the basin, tracer tests and gauging along a stream transect indicate that ground water flowing from talus can account for ≥75% of streamflow during storms and the winter base flow period. The discharge response of talus springs to storms and snowmelt reflects rapid transmittal of water through coarse debris at the talus surface and slower release of water from finer-grained sediments at depth.Ice stored in permafrost (including rock glaciers) is the second largest ground water reservoir in Loch Vale; it represents a significant, but seldom recognized, ground water reservoir in alpine terrain. Mean annual air temperatures are sufficiently cold to support permafrost above 3460 m; however, air temperatures have increased 1.1° to 1.4°C since the early 1990s, consistent with long-term (1976–2000) increases in air temperature measured at other high-elevation sites in the Front Range, European Alps, and Peruvian Andes. If other climatic factors remain constant, the increase in air temperatures at Loch Vale is sufficient to increase the lower elevational limit of permafrost by 150 to 190 m. Although this could cause a short-term increase in streamflow, it may ultimately result in decreased flow in the future.

  2. Aerosol optical extinction during the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ) 2014 summertime field campaign, Colorado, USA

    National Research Council Canada - National Science Library

    Justin H Dingle; Eric C Apel; Teresa L Campos; Alan J Hills; Rebecca S Hornbrook; Denise D Montzka; John B Nowak; Joseph R Roscioli


      Summertime aerosol optical extinction (βext) was measured in the Colorado Front Range and Denver metropolitan area as part of the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ...

  3. Integrating soils and geomorphology in mountains - An example from the Front Range of Colorado (United States)

    Birkeland, P.W.; Shroba, R.R.; Burns, S.F.; Price, A.B.; Tonkin, P.J.


    Soil distribution in high mountains reflects the impact of several soil-forming factors. Soil geomorphologists use key pedological properties to estimate ages of Quaternary deposits of various depositional environments, estimate long-term stability and instability of landscapes, and make inferences on past climatic change. Once the influence of the soil-forming factors is known, soils can be used to help interpret some aspects of landscape evolution that otherwise might go undetected. The Front Range of Colorado rises from the plains of the Colorado Piedmont at about 1700 m past a widespread, dissected Tertiary erosion surface between 2300 and 2800 m up to an alpine Continental Divide at 3600 to over 4000 m. Pleistocene valley glaciers reached the western edge of the erosion surface. Parent rocks are broadly uniform (granitic and gneissic). Climate varies from 46 cm mean annual precipitation (MAP) and 11 ??C mean annual temperature (MAT) in the plains to 102 cm and -4 ??C, respectively, near the range crest. Vegetation follows climate with grassland in the plains, forest in the mountains, and tundra above 3450 m. Soils reflect the bioclimatic transect from plains to divide: A/Bw or Bt/Bk or K (grassland) to A/E/Bw or Bt/C (forest) to A/Bw/C (tundra). Corresponding soil pH values decrease from 8 to less than 5 with increasing elevation. The pedogenic clay minerals dominant in each major vegetation zone are: smectite (grassland), vermiculite (forest), and 1.0-1.8 nm mixed-layer clays (tundra). Within the lower forested zone, the topographic factor (aspect) results in more leached, colder soils, with relatively thin O horizons, well-expressed E horizons and Bt horizons (Alfisols) on N-facing slopes, whereas soils with thicker A horizons, less developed or no E horizons, and Bw or Bt horizons (Mollisols) are more common on S-facing slopes. The topographic factor in the tundra results in soil patterns as a consequence of wind-redistributed snow and the amount of time it

  4. Natural hazard understanding in the middle schools of the Colorado Front Range

    Energy Technology Data Exchange (ETDEWEB)

    Grogger, P.K. [Univ. of Colorado, Colorado Springs, CO (United States). Dept. of Geology


    The best form of mitigation is not to put one`s self in a position that mitigation is required. For the last five years the University of Colorado`s Department of Geology has teamed with local school districts to implement an understanding of natural hazards. By working with middle school students the dangers and possible mitigation of North America are learned at an early age. Over the years, the knowledge gained by these communities citizens will hopefully help lessen the dangers from natural hazards society faces. Education of the general public about natural hazards needs to be addressed by the professional societies studying and developing answers to natural hazards problems. By working with school children this process of educating the general public starts early in the education system and will bear fruit many years in the future. This paper describes the course that is being given to students in Colorado.

  5. WATER SPOTTERS: Water, energy, isotopes and experiential learning in the Colorado Front Range (United States)

    Noone, D. C.; Berkelhammer, M. B.; Raudzens Bailey, A.; Buhr, S. M.; Smith, L. K.


    Providing students with tangible examples of the two-way interaction between human society and the climate system is a pressing challenge. Water is at the core of many issues in environmental change from local to global scales. In climate research, there are significant uncertainties in the role water plays in the climate system. "Water" can also act as a central theme that provides opportunities for science education at all levels. WATER SPOTTERS takes advantage of the prominent agricultural landscape of the region, which is a poignant example of how society influences the climate through irrigation, evaporation/transpiration and run-off and whose productivity is influenced by the climate system. Both natural grasslands and alpine ecosystems in the surrounding regions serve as examples of the native landscape. The centerpiece of this project is a 300m tower that is fully implemented with gas sampling lines and micrometeorological equipment to study the energy and water budgets of the region. Middle Schools that surround this site, many of which exist in visual contact with the tall tower, are provided with meteorological stations, which provide rainfall rates, temperature, humidity and radiation data. In coordination with the St Vrain Valley School District MESA (Math Engineering Science Achievement) program, students collect rain water samples that are analyzed and used as a core component of the research goals. The students use the weather stations as a way to directly explore their local climatology and provide data that is needed in research. We present an overview of the curriculum goals and associated physical infrastructure designed for middle school students in the Colorado Front Range to explore their local water cycle using water isotopes. The fixed infrastructure at the schools and tall tower are supplemented by mobile instruments such as an automated precipitation collector and snowflake photography system, which both fulfill science needs and provide

  6. Field, model, and computer simulation study of some aspects of the origin and distribution of Colorado Plateau-type uranium deposits (United States)

    Ethridge, F.G.; Sunada, D.K.; Tyler, Noel; Andrews, Sarah


    Numerous hypotheses have been proposed to account for the nature and distribution of tabular uranium and vanadium-uranium deposits of the Colorado Plateau. In one of these hypotheses it is suggested that the deposits resulted from geochemical reactions at the interface between a relatively stagnant groundwater solution and a dynamic, ore-carrying groundwater solution which permeated the host sandstones (Shawe, 1956; Granger, et al., 1961; Granger, 1968, 1976; and Granger and Warren, 1979). The study described here was designed to investigate some aspects of this hypothesis, particularly the nature of fluid flow in sands and sandstones, the nature and distribution of deposits, and the relations between the deposits and the host sandstones. The investigation, which was divided into three phases, involved physical model, field, and computer simulation studies. During the initial phase of the investigation, physical model studies were conducted in porous-media flumes. These studies verified the fact that humic acid precipitates could form at the interface between a humic acid solution and a potassium aluminum sulfate solution and that the nature and distribution of these precipitates were related to flow phenomena and to the nature and distribution of the host porous-media. During the second phase of the investigation field studies of permeability and porosity patterns in Holocene stream deposits were investigated and the data obtained were used to design more realistic porous media models. These model studies, which simulated actual stream deposits, demonstrated that precipitates possess many characteristics, in terms of their nature and relation to host sandstones, that are similar to ore deposits of the Colorado Plateau. The final phase of the investigation involved field studies of actual deposits, additional model studies in a large indoor flume, and computer simulation studies. The field investigations provided an up-to-date interpretation of the depositional

  7. Predispersal home range shift of an ocelot Leopardus pardalis (Carnivora: Felidae on Barro Colorado Island, Panama

    Directory of Open Access Journals (Sweden)

    Rafael Mares


    Full Text Available Home range shifts prior to natal dispersal have been rarely documented, yet the events that lead a subadult to abandon a portion of its home range and venture into unfamiliar territories, before eventually setting off to look for a site to reproduce, are probably related to the causes of dispersal itself. Here, we used a combination of manual radio-tracking and an Automated Radio Telemetry System to continuously study the movements of a subadult male ocelot (Leopardus pardalis, a solitary carnivore with sex-biased dispersal, on Barro Colorado Island, Panama, for 18 months from May 2003 through October 2004. The subadult ocelot’s parents were also radio-tracked to record possible parent-offspring interactions within their home ranges. At the age of ca. 21 months the subadult gradually began to shift its natal home range, establishing a new one used until the end of the study, in an area that had previously been used by another dispersing subadult male. Only three parent-offspring interactions were recorded during the four months around the time the range-shift occurred. The apparent peaceful nature of these encounters, along with the slow transition out of a portion of his natal home range, suggest the subadult was not evicted from his natal area by his parents. The timing of the shift, along with the subadult’s increase in weight into the weight range of adult ocelots four months after establishing the new territory, suggests that predispersal home range shifts could act as a low risk and opportunistic strategy for reaching adult size, while minimizing competition with parents and siblings, in preparation for an eventual dispersal into a new breeding territory. Rev. Biol. Trop. 56 (2: 779-787. Epub 2008 June 30.Los desplazamientos del ámbito hogareño de mamíferos subadultos previos a la dispersión natal rara vez han sido documentados. Sin embargo, los eventos que llevan a un animal subadulto a abandonar una parte de su ámbito natal

  8. C3 and C4 plant responses to increased temperatures and altered monsoonal precipitation in a cool desert on the Colorado Plateau, USA (United States)

    Wertin, Timothy M.; Reed, Sasha C.; Belnap, Jayne


    Dryland ecosystems represent >40 % of the terrestrial landscape and support over two billion people; consequently, it is vital to understand how drylands will respond to climatic change. However, while arid and semiarid ecosystems commonly experience extremely hot and dry conditions, our understanding of how further temperature increases or altered precipitation will affect dryland plant communities remains poor. To address this question, we assessed plant physiology and growth at a long-term (7-year) climate experiment on the Colorado Plateau, USA, where the community is a mix of shallow-rooted C3 and C4 grasses and deep-rooted C4 shrubs. The experiment maintained elevated-temperature treatments (+2 or +4 °C) in combination with altered summer monsoonal precipitation (+small frequent precipitation events or +large infrequent events). Increased temperature negatively affected photosynthesis and growth of the C3 and C4 grasses, but effects varied in their timing: +4 °C treatments negatively affected the C3 grass early in the growing season of both years, while the negative effects of temperature on the C4 grass were seen in the +2 and +4 °C treatments, but only during the late growing season of the drier year. Increased summer precipitation did not affect photosynthesis or biomass for any species, either in the year the precipitation was applied or the following year. Although previous research suggests dryland plants, and C4 grasses in particular, may respond positively to elevated temperature, our findings from a cool desert show marked declines in C3 and C4 photosynthesis and growth, with temperature effects dependent on the degree of warming and growing-season precipitation.

  9. Recovery of small pile burn scars in conifer forests of the Colorado Front Range (United States)

    Charles C. Rhoades; Paula J. Fornwalt; Mark W. Paschke; Amber Shanklin; Jayne L. Jonas


    The ecological consequences of slash pile burning are a concern for land managers charged with maintaining forest soil productivity and native plant diversity. Fuel reduction and forest health management projects have created nearly 150,000 slash piles scheduled for burning on US Forest Service land in northern Colorado. The vast majority of these are small piles (

  10. Higher measured than modeled ozone production at increased NOx levels in the Colorado Front Range (United States)

    Baier, Bianca C.; Brune, William H.; Miller, David O.; Blake, Donald; Long, Russell; Wisthaler, Armin; Cantrell, Christopher; Fried, Alan; Heikes, Brian; Brown, Steven; McDuffie, Erin; Flocke, Frank; Apel, Eric; Kaser, Lisa; Weinheimer, Andrew


    Chemical models must correctly calculate the ozone formation rate, P(O3), to accurately predict ozone levels and to test mitigation strategies. However, air quality models can have large uncertainties in P(O3) calculations, which can create uncertainties in ozone forecasts, especially during the summertime when P(O3) is high. One way to test mechanisms is to compare modeled P(O3) to direct measurements. During summer 2014, the Measurement of Ozone Production Sensor (MOPS) directly measured net P(O3) in Golden, CO, approximately 25 km west of Denver along the Colorado Front Range. Net P(O3) was compared to rates calculated by a photochemical box model that was constrained by measurements of other chemical species and that used a lumped chemical mechanism and a more explicit one. Median observed P(O3) was up to a factor of 2 higher than that modeled during early morning hours when nitric oxide (NO) levels were high and was similar to modeled P(O3) for the rest of the day. While all interferences and offsets in this new method are not fully understood, simulations of these possible uncertainties cannot explain the observed P(O3) behavior. Modeled and measured P(O3) and peroxy radical (HO2 and RO2) discrepancies observed here are similar to those presented in prior studies. While a missing atmospheric organic peroxy radical source from volatile organic compounds co-emitted with NO could be one plausible solution to the P(O3) discrepancy, such a source has not been identified and does not fully explain the peroxy radical model-data mismatch. If the MOPS accurately depicts atmospheric P(O3), then these results would imply that P(O3) in Golden, CO, would be NOx-sensitive for more of the day than what is calculated by models, extending the NOx-sensitive P(O3) regime from the afternoon further into the morning. These results could affect ozone reduction strategies for the region surrounding Golden and possibly other areas that do not comply with national ozone regulations

  11. Higher measured than modeled ozone production at increased NOx levels in the Colorado Front Range

    Directory of Open Access Journals (Sweden)

    B. C. Baier


    Full Text Available Chemical models must correctly calculate the ozone formation rate, P(O3, to accurately predict ozone levels and to test mitigation strategies. However, air quality models can have large uncertainties in P(O3 calculations, which can create uncertainties in ozone forecasts, especially during the summertime when P(O3 is high. One way to test mechanisms is to compare modeled P(O3 to direct measurements. During summer 2014, the Measurement of Ozone Production Sensor (MOPS directly measured net P(O3 in Golden, CO, approximately 25 km west of Denver along the Colorado Front Range. Net P(O3 was compared to rates calculated by a photochemical box model that was constrained by measurements of other chemical species and that used a lumped chemical mechanism and a more explicit one. Median observed P(O3 was up to a factor of 2 higher than that modeled during early morning hours when nitric oxide (NO levels were high and was similar to modeled P(O3 for the rest of the day. While all interferences and offsets in this new method are not fully understood, simulations of these possible uncertainties cannot explain the observed P(O3 behavior. Modeled and measured P(O3 and peroxy radical (HO2 and RO2 discrepancies observed here are similar to those presented in prior studies. While a missing atmospheric organic peroxy radical source from volatile organic compounds co-emitted with NO could be one plausible solution to the P(O3 discrepancy, such a source has not been identified and does not fully explain the peroxy radical model–data mismatch. If the MOPS accurately depicts atmospheric P(O3, then these results would imply that P(O3 in Golden, CO, would be NOx-sensitive for more of the day than what is calculated by models, extending the NOx-sensitive P(O3 regime from the afternoon further into the morning. These results could affect ozone reduction strategies for the region surrounding Golden and possibly other areas that do not comply with national ozone

  12. Fuel and stand characteristics in p. pine infested with mountain pine beetle, Ips beetle, and southwestern dwarf mistletoe in Colorado's Northern Front Range (United States)

    Jennifer G. Klutsch; Russell D. Beam; William R. Jacobi; Jose F. Negron


    In the ponderosa pine forests of the northern Front Range of Colorado, downed woody debris amounts, fuel arrangement, and stand characteristics were assessed in areas infested with southwestern dwarf mistletoe (Arceuthobium vaginatum subsp. cryptopodum), mountain pine beetle (Dendroctonus ponderosae) and

  13. Fuel loads and simulated fire behavior in "old-stage" beetle-infested ponderosa pine of the Colorado Plateau (United States)

    E. Matthew Hansen; Morris C. Johnson; Barbara J. Bentz; James C. Vandygriff; A. Steven. Munson


    Recent bark beetle outbreaks in western North America have led to concerns regarding changes in fuel profiles and associated changes in fire behavior. Data are lacking for a range of infestation severities and time since outbreak, especially for relatively arid cover types. We surveyed fuel loads and simulated fire behavior for ponderosa pine stands of the...

  14. Quantifying the Contribution of Thermally Driven Recirculation to a High-Ozone Event Along the Colorado Front Range Using Lidar (United States)

    Sullivan, John T.; McGee, Thomas J.; Langford, Andrew O.; Alvarez, Raul J., II; Senff, Christoph; Reddy, Patrick J.; Thompson, Anne M.; Twigg, Laurence W.; Sumnicht, Grant K.; Lee, Pius; hide


    A high-ozone (O3) pollution episode was observed on 22 July 2014 during the concurrent Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) and Front Range Air Pollution and Photochemistry Experiment (FRAPPE) campaigns in northern Colorado. Surface O3 monitors at three regulatory sites exceeded the Environmental Protection Agency (EPA) 2008 National Ambient Air Quality Standard (NAAQS) daily maximum 8h average (MDA8) of 75ppbv. To further characterize the polluted air mass and assess transport throughout the event, measurements are presented from O3 and wind profilers, O3-sondes, aircraft, and surface-monitoring sites. Observations indicate that thermally driven upslope flow was established throughout the Colorado Front Range during the pollution episode. As the thermally driven flow persisted throughout the day, O3 concentrations increased and affected high-elevation Rocky Mountain sites. These observations, coupled with modeling analyses, demonstrate a westerly return flow of polluted air aloft, indicating that the mountain-plains solenoid circulation was established and impacted surface conditions within the Front Range.

  15. Rock Geochemistry and Mineralogy from Fault Zones and Polymetallic Fault Veins of the Central Front Range, Colorado (United States)

    Caine, Jonathan S.; Bove, Dana J.


    During the 2004 to 2008 field seasons, approximately 200 hand samples of fault and polymetallic vein-related rocks were collected for geochemical and mineralogical analyses. The samples were collected by the U.S. Geological Survey as part of the Evolution of Brittle Structures Task under the Central Colorado Assessment Project (CCAP) of the Mineral Resources Program ( The purpose of this work has been to characterize the relation between epithermal, polymetallic mineral deposits, paleostress, and the geological structures that hosted fluid flow and localization of the deposits. The data in this report will be used to document and better understand the processes that control epithermal mineral-deposit formation by attempting to relate the geochemistry of the primary structures that hosted hydrothermal fluid flow to their heat and fluid sources. This includes processes from the scale of the structures themselves to the far field scale, inclusive of the intrusive bodies that have been thought to be the sources for the hydrothermal fluid flow. The data presented in this report are part of a larger assessment effort on public lands. The larger study area spans the region of the southern Rocky Mountains in Colorado from the Wyoming to New Mexico borders and from the eastern boundary of the Front Range to approximately the longitude of Vail and Leadville, Colorado. Although the study area has had an extensive history of geological mapping, the mapping has resulted in a number of hypotheses that are still in their infancy of being tested. For example, the proximity of polymetallic veins to intrusive bodies has been thought to reflect a genetic relation between the two features; however, this idea has not been well tested with geochemical indicators. Recent knowledge regarding the coupled nature of stress, strain, fluid flow, and geochemistry warrant new investigations and approaches to test a variety of

  16. Impact of diurnal temperature range on mortality in a high plateau area in southwest China: A time series analysis. (United States)

    Ding, Zan; Guo, Pi; Xie, Fang; Chu, Huifang; Li, Kun; Pu, Jingbo; Pang, Shaojie; Dong, Hongli; Liu, Yahui; Pi, Fuhua; Zhang, Qingying


    Diurnal temperature range (DTR) is an important meteorological indicator that reflects weather stability and is associated with global climate change and urbanization. Previous studies have explored the effect of DTR on human health in coastal cities with small daily temperature variations, but we have little evidence for high plateau regions where large DTRs usually occur. Using daily mortality data (2007-2013), we conducted a time-series analysis to assess the effect of DTR on daily mortality in Yuxi, a high plateau city in southwest China. Poisson regression with distributed lag non-linear model was used to estimate DTR effects on daily mortality, controlling for daily mean temperature, relative humidity, sunshine duration, wind speed, atmospheric pressure, day of the week, and seasonal and long-term trends. The cumulative effects of DTR were J-shaped curves for non-accidental, cardiorespiratory and cardiovascular mortality, with a U-shaped curve for respiratory mortality. Risk assessments showed strong monotonic increases in mortality starting at a DTR of approximately 16 °C. The relative risk of non-accidental morality with extreme high DTR at lag 0 and 0-21 days was 1.03 (95% confidence interval: 0.95-1.11) and 1.33 (0.94-1.89), respectively. The risk of mortality with extreme high DTR was greater for males and age DTR on mortality was non-linear, with high DTR associated with increased mortality. A DTR of 16 °C may be a cut-off point for mortality prognosis and has implications for developing intervention strategies to address high DTR exposure. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. The influence of vegetation cover on debris-flow density during an extreme rainfall in the northern Colorado Front Range (United States)

    Rengers, Francis; McGuire, Luke; Coe, Jeffrey A.; Kean, Jason W.; Baum, Rex L.; Staley, Dennis M.; Godt, Jonathan W.


    We explored regional influences on debris-flow initiation throughout the Colorado Front Range (Colorado, USA) by exploiting a unique data set of more than 1100 debris flows that initiated during a 5 day rainstorm in 2013. Using geospatial data, we examined the influence of rain, hillslope angle, hillslope aspect, and vegetation density on debris-flow initiation. In particular we used a greenness index to differentiate areas of high tree density from grass and bare soil. The data demonstrated an overwhelming propensity for debris-flow initiation on south-facing hillslopes. However, when the debris-flow density was analyzed with respect to total rainfall and greenness we found that most debris flows occurred in areas of high rainfall and low tree density, regardless of hillslope aspect. These results indicate that present-day tree density exerts a stronger influence on debris-flow initiation locations than aspect-driven variations in soil and bedrock properties that developed over longer time scales.

  18. Entomological studies along the Colorado Front Range during a period of intense West Nile virus activity. (United States)

    Bolling, B G; Moore, C G; Anderson, S L; Blair, C D; Beaty, B J


    To better understand the ecology of West Nile virus transmission in Northern Colorado, field studies were conducted in Larimer and Weld counties from September 2003 through March 2005. During summer studies, 18,540 adult mosquitoes were collected using light traps and gravid traps. West Nile virus RNA was detected in 24 of the 2,140 mosquito pools tested throughout the study area in 2003 and 2004. Culex tarsalis had the highest minimum infection rate (MIR) in both 2003 (MIR = 34.48) and in 2004 (MIR = 8.74). During winter studies, 9,391 adult mosquitoes were collected by aspirator from various overwintering sites including bridges and storm drains. The most frequently collected species was Culex pipiens. West Nile virus was not detected in our overwintering collections. The relationship between spring adult emergence and temperature inside and outside overwintering sites is described. Species composition of collections as well as the spatial and temporal distribution of West Nile virus detections are presented.

  19. The Relative Importance of HNO3 and RONO2 as NOX Sinks in the Colorado Front Range (United States)

    Sparks, T.; Ebben, C. J.; Wooldridge, P. J.; Cohen, R. C.


    NOX (NO + NO2) is a regulated pollutant, primarily emitted from combustion processes, that contributes to the formation of ground level ozone. The lifetime of NOX in the atmosphere, and therefore its contribution to ozone production, is controlled by the loss of NOX to various sinks, primarily HNO3 and RONO2. As NOX concentrations in urban areas decrease due to regulation, the relative importance of these NOX sinks shifts from HNO3 being the dominant sink to RONO2 becoming more significant. Using measurements from the DISCOVER-AQ and FRAPPE campaigns from the summer of 2014, we examine the relative importance of HNO3 and RONO2 as NOX sinks and their relation to NOX concentration in the Colorado Front Range.

  20. Climate Drives Episodic Conifer Establishment after Fire in Dry Ponderosa Pine Forests of the Colorado Front Range, USA

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    Monica T. Rother


    Full Text Available In recent years, warming climate and increased fire activity have raised concern about post-fire recovery of western U.S. forests. We assessed relationships between climate variability and tree establishment after fire in dry ponderosa pine forests of the Colorado Front Range. We harvested and aged over 400 post-fire juvenile ponderosa pine (Pinus ponderosa and Douglas-fir (Pseudotsuga menziesii trees using an improved tree-ring based approach that yielded annually-resolved dates and then assessed relationships between climate variability and pulses of tree establishment. We found that tree establishment was largely concentrated in years of above-average moisture availability in the growing season, including higher amounts of precipitation and more positive values of the Palmer Drought Severity Index. Under continued climate change, drier conditions associated with warming temperatures may limit forest recovery after fire, which could result in lower stand densities or shifts to non-forested vegetation in some areas.

  1. Links between N deposition and nitrate export from a high-elevation watershed in the Colorado Front Range (United States)

    Mast, M. Alisa; Clow, David W.; Baron, Jill S.; Wetherbee, Gregory A.


    Long-term patterns of stream nitrate export and atmospheric N deposition were evaluated over three decades in Loch Vale, a high-elevation watershed in the Colorado Front Range. Stream nitrate concentrations increased in the early 1990s, peaked in the mid-2000s, and have since declined by over 40%, coincident with trends in nitrogen oxide emissions over the past decade. Similarities in the timing and magnitude of N deposition provide evidence that stream chemistry is responding to changes in atmospheric deposition. The response to deposition was complicated by a drought in the early 2000s that enhanced N export for several years. Other possible explanations, including forest disturbance, snow depth, or permafrost melting, could not explain patterns in N export. Our results show that stream chemistry responds rapidly to changes in N deposition in high-elevation watersheds, similar to the response observed to changes in sulfur deposition.

  2. Hydrochemical responses to climate change in high-elevation catchments of the Colorado Front Range. (Invited) (United States)

    Williams, M. W.


    Potential climate impacts on the hydrochemistry of two seasonally snow covered catchments is evaluated using 24 years of data from the Niwot Ridge Long Term Ecological Research Site, Colorado. At the larger (220 ha), higher elevation (3570 m) GL4 catchment annual discharge did not change significantly based on nonparametric trend testing. However, October streaflow volumes and groundwater storage did increase, despite drought conditions near the end of the record in 2000-2004. In contrast, at the smaller (8 ha), lower elevation (3400 m) MART catchment, annual discharge decreased significantly over the study period with the most substantial changes in July-September. The study period was separated into "wet", "normal", and "dry" years based on the 75th and 25th quartiles of annual precipitation. Results indicate that MART is particularly sensitive to changes in precipitation with dry years exhibiting decreased snowmelt peak flows, earlier snowmelt timing, decreased annual discharge, and reduced late-season flows. GL4 was less susceptible to changes in precipitation and surprisingly late-season flow volumes (Sept.-Oct.) were not significantly different between wet, normal, and dry conditions. Surprisingly, during dry years both the concentrations and annual fluxes of Ca2+ and SO42- increased in the outflow of GL4, but not at the Martinelli catchment. These changes in hydrochemistry were particularly pronounced during the low-flow period. Streamwater chemistry in GL4 during drought years resembled that of permafrost, suggesting augmented flow during the fall due to permafrost melt. This study shows that seasonally snow covered catchments are particularly sensitive to changes in climate, but the hydrochemical response may depend on landscape characteristics.

  3. Mineralization and other geologic factors related to the Morrison Formation in particular the northern two-thirds of the Colorado Plateau region; basic data and factor-analysis results (United States)

    Cadigan, Robert Allen


    A vanadium-mercury mineralization factor and five other significant geologic factors were determined by multivariate factor analysis of data for Morrison Formation rock samples from the Colorado Plateau region. The data presented in the report were obtained from an agglomeration of 876 samples which yielded a correlation matrix of 44 variables. The variables consisted of geochemical, petrographic, and geographic location parameters. Mineralization factor scores demonstrate the relative intensity of mineralization in rock samples collected in and around uranium-vanadium ore deposits. The factors affecting composition and texture of the rocks identified from the analysis are: (1) metalliferous mudstones; (2) interstitial carbonate cements; (3) competing sources of different composition; (4) heavy mineral sources; (5) vanadium mineralization; and (6) regional and stratigraphic sampling bias.

  4. Climate impacts on the hydrology of high elevation catchments, Colorado Front Range (United States)

    Williams, M.; Hill, K.; Caine, N.; Janke, J.


    Potential climate impacts on the hydrology of two seasonally snow covered catchments is evaluated using 24 years of data from Niwot Ridge Long Term Ecological Research Site, Colorado. At the larger (220 ha), higher elevation (3570 m) GL4 catchment annual discharge did not change significantly based on nonparametric trend testing. However, October streamflow volumes and groundwater storage did increase, despite drought conditions near the end of the record in 2000-2004. In contrast, at the smaller (8 ha), lower elevation (3400 m) MART catchment, annual discharge decreased significantly over the study period with the most substantial changes in July-September. The study period was separated into "wet", "normal", and "dry" years based on the 75th and 25th quartiles of annual precipitation. Results indicate that MART is particularly sensitive to changes in precipitation with dry years exhibiting decreased snowmelt peak flows, earlier snowmelt timing, decreased annual discharge, and reduced late-season flows. GL4 was less susceptible to changes in precipitation and surprisingly late-season flow volumes (Sept.-Oct.) were not significantly different between wet, normal, and dry conditions. Glacial melt from the Arikaree glacier may account for up to 43% of the increase in late-season flows based on ablation measurements. We downscaled a regional permafrost model based on topoclimatic variables to assess whether subsurface ice within permafrost and rock glaciers could account for the remaining deficiency. Results suggest that with only 1° C of warming over 1/3 of permafrost area would be lost. Over the study period mean annual minimum temperatures increased by 0.6° decade-1, with the some of most prominent increases occurring in July (1.5° C decade-1). Additionally, limited ground temperature measurements at an active rock glacier indicate a 1° C increase over the past decade. This suggests that the source of late-season streamflow at GL4 has shifted towards permafrost

  5. Heating, cooling, and uplift during Tertiary time, northern Sangre de Cristo Range, Colorado ( USA). (United States)

    Lindsay, D.A.; Andriessen, P.A.M.; Wardlaw, B.R.


    Paleozoic sedimentary rocks in a wide area of the northern Sangre de Cristo Range show effects of heating during Tertiary time. Heating is tentatively interpreted as a response to burial during Laramide folding and thrusting and also to high heat flow during Rio Grande rifting. Fission-track ages of apatite across a section of the range show that rocks cooled abruptly below 120oC, the blocking temperature for apatite, approx 19 Ma ago. Cooling was probably in response to rapid uplift and erosion of the northern Sangre de Cristo Range during early Rio Grande rifting.-from Authors

  6. Douglas-fir tussock moth- and Douglas-fir beetle-caused mortality in a ponderosa pine/Douglas-fir forest in the Colorado Front Range, USA (United States)

    Jose F. Negron; Ann M. Lynch; Willis C. Schaupp; Vladimir Bocharnikov


    An outbreak of the Douglas-fir tussock moth, Orgyia pseudotsugata McDunnough, occurred in the South Platte River drainage on the Pike-San Isabel National Forest in the Colorado Front Range attacking Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco. Stocking levels, species composition, and tree size in heavily and lightly defoliated stands were similar. Douglas-fir...

  7. Potential Areas of Future Oil and Gas Development, Greater Wattenberg Area, Front Range of Colorado (friogdevu) (United States)

    U.S. Geological Survey, Department of the Interior — The potential for oil and gas development in the greater Wattenberg area (GWA), which lies near the Front Range between Denver and Greeley, Colo., in the Denver...

  8. Source characterization of volatile organic compounds in the Colorado Northern Front Range Metropolitan Area during spring and summer 2015 (United States)

    Abeleira, A.; Pollack, I. B.; Sive, B.; Zhou, Y.; Fischer, E. V.; Farmer, D. K.


    Hourly measurements of 46 volatile organic compounds (VOCs) from the Boulder Atmospheric Observatory in Erie, CO, were collected over 16 weeks in spring and summer 2015. Average VOC reactivity (1.2 s-1 in spring and 2.4 s-1 in summer) was lower than most other U.S. urban sites. Positive matrix factorization analysis identified five VOC factors in the spring, corresponding to sources from (1) long-lived oil and natural gas (ONG-long lived), (2) short-lived oil and natural gas (ONG-short lived), (3) traffic, (4) background, and (5) secondary chemical production. In the summer, an additional biogenic factor was dominated by isoprene. While ONG-related VOCs were the single largest contributor (40-60%) to the calculated VOC reactivity with hydroxyl radicals (OH) throughout the morning in both spring and summer, the biogenic factor substantially enhanced afternoon and evening (2-10 P.M. local time) VOC reactivity (average of 21%; maxima of 49% of VOC reactivity) during summertime. These results contrast with a previous summer 2012 campaign which showed that biogenics contributed only 8% of VOC reactivity on average. The interannual differences suggest that the role of biogenic VOCs in the Colorado Northern Front Range Metropolitan Area (NFRMA) varies with environmental conditions such as drought stress. Overall, the NFRMA was more strongly influenced by ONG sources of VOCs than other urban and suburban regions in the U.S.

  9. The occurrence of alpine permafrost in the Front Range of Colorado (United States)

    Janke, Jason R.


    Permafrost distribution, or ground that remains frozen for at least 2 years, has been modeled using a combination of Geographic Information System (GIS) techniques, Digital Elevation Model (DEM) variables, and land cover in alpine regions of the world. In the Front Range, however, no such empirical models have been developed, and field data are restricted in spatial extent, but rock glaciers are in abundance. Here, I present a probabilistic logistic regression model that is based on topoclimatic information (elevation and aspect) for rock glaciers derived from U.S. Geological Survey (USGS) 10-m DEMs. Classes of land cover, obtained from an Enhanced Thematic Mapper Plus (ETM+) image classification, were assigned weights and were then multiplied by the regression results to refine estimates. The effectiveness of the model was evaluated by comparing mean probability scores with rock glacier activity categories, Mean Annual Air Temperature (MAAT) from climatic stations on Niwot Ridge, and Bottom Temperature of winter Snow (BTS) measurements, while a Monte Carlo simulation was used to detect uncertainty associated with the original DEM. Permafrost scores >50% covered about 8.9% (242 km 2) of the study area (2722 km 2) with the highest scores clustered around Longs and Rowe Peaks. Permafrost locations showed a strong correlation with rock glacier activity classes, the -1.0 °C MAAT isotherm, and BTS measurements less than -3.0 °C. The uncertainty analysis revealed that slight global differences exist between the original and error prone DEM; however, local variations in aspect caused the most uncertainty. These results indicate that the model accurately represents regional distribution of permafrost. Therefore, topoclimatic information from rock glaciers and land cover, when combined with an uncertainty analysis, can effectively be used to map the occurrence of Front Range permafrost, providing an imperative tool for cartographers, planners, and geocryologists.

  10. Groundwater-quality data in the Cascade Range and Modoc Plateau study unit, 2010-Results from the California GAMA Program (United States)

    Shelton, Jennifer L.; Fram, Miranda S.; Belitz, Kenneth


    Groundwater quality in the 39,000-square-kilometer Cascade Range and Modoc Plateau (CAMP) study unit was investigated by the U.S. Geological Survey (USGS) from July through October 2010, as part of the California State Water Resources Control Board (SWRCB) Groundwater Ambient Monitoring and Assessment (GAMA) Program’s Priority Basin Project (PBP). The GAMA PBP was developed in response to the California Groundwater Quality Monitoring Act of 2001 and is being conducted in collaboration with the SWRCB and Lawrence Livermore National Laboratory (LLNL). The CAMP study unit is the thirty-second study unit to be sampled as part of the GAMA PBP. The GAMA CAMP study was designed to provide a spatially unbiased assessment of untreated-groundwater quality in the primary aquifer system and to facilitate statistically consistent comparisons of untreated-groundwater quality throughout California. The primary aquifer system is defined as that part of the aquifer corresponding to the open or screened intervals of wells listed in the California Department of Public Health (CDPH) database for the CAMP study unit. The quality of groundwater in shallow or deep water-bearing zones may differ from the quality of groundwater in the primary aquifer system; shallow groundwater may be more vulnerable to surficial contamination. In the CAMP study unit, groundwater samples were collected from 90 wells and springs in 6 study areas (Sacramento Valley Eastside, Honey Lake Valley, Cascade Range and Modoc Plateau Low Use Basins, Shasta Valley and Mount Shasta Volcanic Area, Quaternary Volcanic Areas, and Tertiary Volcanic Areas) in Butte, Lassen, Modoc, Plumas, Shasta, Siskiyou, and Tehama Counties. Wells and springs were selected by using a spatially distributed, randomized grid-based method to provide statistical representation of the study unit (grid wells). Groundwater samples were analyzed for field water-quality indicators, organic constituents, perchlorate, inorganic constituents

  11. The effect of entrainment through atmospheric boundary layer growth on observed and modeled surface ozone in the Colorado Front Range (United States)

    Kaser, L.; Patton, E. G.; Pfister, G. G.; Weinheimer, A. J.; Montzka, D. D.; Flocke, F.; Thompson, A. M.; Stauffer, R. M.; Halliday, H. S.


    Ozone concentrations at the Earth's surface are controlled by meteorological and chemical processes and are a function of advection, entrainment, deposition, and net chemical production/loss. The relative contributions of these processes vary in time and space. Understanding the relative importance of these processes controlling surface ozone concentrations is an essential component for designing effective regulatory strategies. Here we focus on the diurnal cycle of entrainment through atmospheric boundary layer (ABL) growth in the Colorado Front Range. Aircraft soundings and surface observations collected in July/August 2014 during the DISCOVER-AQ/FRAPPÉ (Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality/Front Range Air Pollution and Photochemistry Éxperiment) campaigns and equivalent data simulated by a regional chemical transport model are analyzed. Entrainment through ABL growth is most important in the early morning, fumigating the surface at a rate of 5 ppbv/h. The fumigation effect weakens near noon and changes sign to become a small dilution effect in the afternoon on the order of -1 ppbv/h. The chemical transport model WRF-Chem (Weather Research and Forecasting Model with chemistry) underestimates ozone at all altitudes during this study on the order of 10-15 ppbv. The entrainment through ABL growth is overestimated by the model in the order of 0.6-0.8 ppbv/h. This results from differences in boundary layer growth in the morning and ozone concentration jump across the ABL top in the afternoon. This implicates stronger modeled fumigation in the morning and weaker modeled dilution after 11:00 LT.

  12. The Colorado River (United States)


    This Moderate-resolution Imaging Spectroradiometer (MODIS) true-color image shows the passage of the Colorado River through several southwestern states. The river begins, in this image, in Utah at the far upper right, where Lake Powell is visible as dark pixels surrounded by the salmon-colored rocks of the Colorado Plateau. The Colorado flows southwest through Glen Canyon, to the Glen Canyon Dam, on the Utah-Arizona border. From there it flows south into Arizona, and then turns sharply west where the Grand Canyon of the Colorado cuts through the mountains. The Colorado flows west to the Arizona-Nevada (upper left) border, where it is dammed again, this time by the Hoover Dam. The dark-colored pixels surrounding the bend in the river are Lake Mead. The river flows south along the border of first Nevada and Arizona and then California and Arizona. The Colorado River, which begins in Rocky Mountain National Park in Colorado, empties into the Gulf of California, seen at the bottom center of this image.

  13. Status and understanding of groundwater quality in the Cascade Range and Modoc Plateau study unit, 2010: California GAMA Priority Basin Project (United States)

    Fram, Miranda S.; Shelton, Jennifer L.


    Groundwater quality in the Cascade Range and Modoc Plateau study unit was investigated as part of the California State Water Resources Control Board’s Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project. The study was designed to provide a statistically unbiased assessment of untreated groundwater quality in the primary aquifer system. The depth of the primary aquifer system for the Cascade Range and Modoc Plateau study unit was delineated by the depths of the screened or open intervals of wells in the State of California’s database of public-supply wells. Two types of assessments were made: a status assessment that described the current quality of the groundwater resource, and an understanding assessment that made evaluations of relations between groundwater quality and potential explanatory factors representing characteristics of the primary aquifer system. The assessments characterize the quality of untreated groundwater, not the quality of treated drinking water delivered to consumers by water distributors.

  14. Multi-Temporal Independent Component Analysis and Landsat 8 for Delineating Maximum Extent of the 2013 Colorado Front Range Flood

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    Stephen M. Chignell


    Full Text Available Maximum flood extent—a key data need for disaster response and mitigation—is rarely quantified due to storm-related cloud cover and the low temporal resolution of optical sensors. While change detection approaches can circumvent these issues through the identification of inundated land and soil from post-flood imagery, their accuracy can suffer in the narrow and complex channels of increasingly developed and heterogeneous floodplains. This study explored the utility of the Operational Land Imager (OLI and Independent Component Analysis (ICA for addressing these challenges in the unprecedented 2013 Flood along the Colorado Front Range, USA. Pre- and post-flood images were composited and transformed with an ICA to identify change classes. Flooded pixels were extracted using image segmentation, and the resulting flood layer was refined with cloud and irrigated agricultural masks derived from the ICA. Visual assessment against aerial orthophotography showed close agreement with high water marks and scoured riverbanks, and a pixel-to-pixel validation with WorldView-2 imagery captured near peak flow yielded an overall accuracy of 87% and Kappa of 0.73. Additional tests showed a twofold increase in flood class accuracy over the commonly used modified normalized water index. The approach was able to simultaneously distinguish flood-related water and soil moisture from pre-existing water bodies and other spectrally similar classes within the narrow and braided channels of the study site. This was accomplished without the use of post-processing smoothing operations, enabling the important preservation of nuanced inundation patterns. Although flooding beneath moderate and sparse riparian vegetation canopy was captured, dense vegetation cover and paved regions of the floodplain were main sources of omission error, and commission errors occurred primarily in pixels of mixed land use and along the flood edge. Nevertheless, the unsupervised nature of ICA

  15. Geology of Precambrian rocks and isotope geochemistry of shear zones in the Big Narrows area, northern Front Range, Colorado (United States)

    Abbott, Jeffrey T.


    Rocks within the Big Narrows and Poudre Park quadrangles located in the northern Front Range of Colorado are Precambrian metasedimentary and metaigneous schists and gneisses and plutonic igneous rocks. These are locally mantled by extensive late Tertiary and Quaternary fluvial gravels. The southern boundary of the Log Cabin batholith lies within the area studied. A detailed chronology of polyphase deformation, metamorphism and plutonism has been established. Early isoclinal folding (F1) was followed by a major period of plastic deformation (F2), sillimanite-microcline grade regional metamorphism, migmatization and synkinematic Boulder Creek granodiorite plutonism (1.7 b.y.). Macroscopic doubly plunging antiformal and synformal structures were developed. P-T conditions at the peak of metamorphism were probably about 670?C and 4.5 Kb. Water pressures may locally have differed from load pressures. The 1.4 b.y. Silver Plume granite plutonism was post kinematic and on the basis of petrographic and field criteria can be divided into three facies. Emplacement was by forcible injection and assimilation. Microscopic and mesoscopic folds which postdate the formation of the characteristic mineral phases during the 1.7 b.y. metamorphism are correlated with the emplacement of the Silver Plume Log Cabin batholith. Extensive retrograde metamorphism was associated with this event. A major period of mylonitization postdates Silver Plume plutonism and produced large E-W and NE trending shear zones. A detailed study of the Rb/Sr isotope geochemistry of the layered mylonites demonstrated that the mylonitization and associated re- crystallization homogenized the Rb87/Sr 86 ratios. Whole-rock dating techniques applied to the layered mylonites indicate a probable age of 1.2 b.y. Petrographic studies suggest that the mylonitization-recrystallization process produced hornfels facies assemblages in the adjacent metasediments. Minor Laramide faulting, mineralization and igneous activity

  16. Evaluation of thrusting and folding of the Deadman Creek Thrust Fault, Sangre de Cristo range, Saguache County, Colorado (United States)

    Weigel, Jacob F., II

    The Deadman Creek Thrust Fault was mapped in a structural window on the west side of the Sangre de Cristo Range. The study area, located in southern Colorado, is a two square mile area halfway between the town of Crestone and the Great Sand Dunes National Park. The Deadman Creek Thrust Fault is the center of this study because it delineates the fold structure in the structural window. The fault is a northeast-directed low-angle thrust folded by subsequent additional compression. This study was directed at understanding the motion of the Deadman Creek Thrust Fault as affected by subsequent folding, and the driving mechanism behind the folding of the Pole Creek Anticline as part of a broader study of Laramide thrust faulting in the range. This study aids in the interpretation of the geologic structure of the San Luis Valley, which is being studied by staff of the United States Geological Survey (USGS), to understand Rio Grande Rift basin evolution by focusing on rift and pre-rift tectonic activity. It also provides a geologic interpretation for the Saguache County Forest Service, Great Sand Dunes National Park, and its visitors. The Sangre de Cristo Mountain Range has undergone tectonic events in the Proterozoic, Pennsylvanian (Ancestral Rocky Mountains), Cretaceous-Tertiary (Laramide Orogeny) and mid-Tertiary (Rio Grande Rift). During the Laramide Orogeny the Deadman Creek Thrust Fault emplaced Proterozoic gneiss over Paleozoic sedimentary rocks and Proterozoic granodiorite in the area. Continued deformation resulted in folding of the fault to form the Pole Creek Anticline. The direction of motion of both the fault and fold is northeastward. A self-consistent net of cross-sections and stereonet plots generated from existing and new field data show that the anticline is an overturned isoclinal fold in Pole Creek Canyon, which shows an increasing inter-limb angle and a more vertical axial surface northwestward toward Deadman Creek Canyon. Southwest-directed apparent

  17. Log for Joint SEPM-Colorado Scientific Society field trip, September 20-21, 1986: late Paleozoic sedimentation and Laramide tectonics of the Sangre de Cristo Range, from Westcliffe to Crestone, Colorado (United States)

    Lindsey, David A.


    This trip will cross the northern Sangre de Cristo Range, from Westcliffe to Crestone, Colorado, by way of the Hermit Pass Road and the Rito Alto pack trail (Fig. 1 below; road and trail shown on Fig. 2). The traverse is designed to give the geologist a sample of the structure and stratigraphy of this part of the range. Emphasis will be on the relationship between the horst of the Sangre de Cristo Range and adjacent down-dropped valleys, on the Laramide thrusted structure of the range, and on the stratigraphy and depositional environments of Pennsylvanian and Permian sedimentary rocks in the range.The northern Sangre de Cristo Range is composed mostly of Early and Middle Proterozoic crystalline rocks and Paleozoic clastic sedimentary rocks (see geologic map, Fig. 2). Proterozoic rocks, mostly gneiss and quartz monzonite, are overlain on the west side of the range by about 100 m of early Paleozoic quartzite, dolomite, limestone, and shale. Early Paleozoic rocks are in turn unconformably overlain by Pennsylvanian and Permian clastic rocks. Southeast of the range, in Huerfano Park, Paleozoic rocks are overlain by Jurassic and Cretaceous rocks of the Raton basin.

  18. The Relative Roles of RONO2 and HNO3 as Sinks of NOX in the Denver Metropolitan Region and Colorado's Front Range (United States)

    Sparks, T.; Ebben, C. J.; Wooldridge, P. J.; Cohen, R. C.


    Measurements of HNO3, total RONO2, NOX, and other relevant species, acquired during the DISCOVER-AQ and FRAPPE field campaigns in the Northern Front Range of Colorado during July-August 2014, are used to assess our understanding of the relative roles of RONO2 and HNO3 formation as sinks of NOX. Although HNO3 production was dominant in the region, RONO2 production was often of order 1/3 of the NOX sink. As NOX emissions decrease, our results indicate RONO2­ chemistry will be increasingly important to descriptions of the chemistry in the region.

  19. Environmental Impact Analysis Process. Draft Environmental Assessment. SAC Low-Altitude Flight Operations at the Airburst Range, Colorado (United States)


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  20. Uinta Arch Project: investigations of uranium potential in Precambrian X and older metasedimentary rocks in the Unita and Wasatch ranges, Utah and Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Graff, P.J.; Sears, J.W.; Holden, G.S.


    This study is part of the United States Department of Energy's National Uranium Resource Evaluation Program to understand the geologic setting, amount, and availability of uranium resources within the boundaries of the United States. The systematic study of Precambrian quartz-pebble conglomerates and areas that may contain such conglomerates is an integral part of DOE's resource evaluation program, because deposits of world-wide importance occur in such terrains in Canada and South Africa, and because terrains similar to those producing uranium from quartz-pebble conglomerates exist elsewhere in the United States. Because of the ready availability of Tertiary sandstone and Colorado Plateau-type uranium deposits, large areas of Precambrian rocks in the US have not been fully assessed for uranium potential. Thus, the Uinta Arch Project was undertaken to assess the favorability of Precambrian metasedimentary rocks in northern Utah for deposits of uranium in Precambrian quartz-pebble conglomerates. Rocks of interest to this study are the thick, clastic sequences within the Uinta Arch that are considered to be of Early Proterozoic age. The Uinta Arch area is known to contain rocks which generally fit the lithologic characteristics that are understood to limit the occurrence of Precambrian fossil placers. However, detailed geology of these rocks and their exact fit to the model described for uraniferous conglomerates was not known. The primary goal of the Uinta Arch Project was to determine how well these Precambrian rocks resemble known deposits and to describe the favorability of placer uranium deposits.

  1. Comparison of the Long-Range Climate Memory in Outgoing Longwave Radiation over the Tibetan Plateau and the Indian Monsoon Region

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    Zhongping Shen


    Full Text Available Based on the detrended fluctuation analysis (DFA method, scaling behaviors of the daily outgoing longwave radiation (OLR from 1979 to 2015 over the Tibetan Plateau (TP and the Indian Monsoon Region (IMR are analyzed. The results show that there is long-term memory for the OLR time series over the TP and IMR. The long-range memory behaviors of OLR over TP are stronger than those over IMR. The averaged values of the scaling exponents over TP and IMR are 0.71 and 0.64; the maximum values in the two regions are 0.81 and 0.75; the minimum values are 0.59 and 0.58. The maximum frequency counts for scaling exponents occur in the range of 0.625 and 0.675 both in TP and in IMR. The spatial distribution of the scaling exponents of the OLR sequence is closely related to the conditions of climatic high cloud cover in the two areas. The high cloud cover over TP is obviously less than that of IMR. In addition, the scaling behaviors of OLR over TP and IMR are caused by the fractal characteristics of time series, which is further proved by randomly disrupting the time series to remove trends and correlation.

  2. Aspect-dependent soil saturation and insight into debris-flow initiation during extreme rainfall in the Colorado Front Range (United States)

    Ebel, Brian A.; Rengers, Francis K.; Tucker, Gregory E.


    Hydrologic processes during extreme rainfall events are poorly characterized because of the rarity of measurements. Improved understanding of hydrologic controls on natural hazards is needed because of the potential for substantial risk during extreme precipitation events. We present field measurements of the degree of soil saturation and estimates of available soil-water storage during the September 2013 Colorado extreme rainfall event at burned (wildfire in 2010) and unburned hillslopes with north- and south-facing slope aspects. Soil saturation was more strongly correlated with slope aspect than with recent fire history; south-facing hillslopes became fully saturated while north-facing hillslopes did not. Our results suggest multiple explanations for why aspect-dependent hydrologic controls favor saturation development on south-facing slopes, causing reductions in effective stress and triggering of slope failures during extreme rainfall. Aspect-dependent hydrologic behavior may result from (1) a larger gravel and stone fraction, and hence lower soil-water storage capacity, on south-facing slopes, and (2) lower weathered-bedrock permeability on south-facing slopes, because of lower tree density and associated deep roots penetrating bedrock as well as less intense weathering, inhibiting soil drainage.

  3. VOC Measurements in the Northern Colorado Front Range Metropolitan Area: Investigating the Impact of Oil and Natural Gas Emissions on O3 Production (United States)

    Abeleira, A.; Farmer, D.; Fischer, E. V.; Pollack, I. B.; Zaragoza, J.


    Authors: Ilana Pollock1,2, Jake Zaragoza2, Emily V. Fischer2, Delphine K. Farmer11. Department of Chemistry, Colorado State University, Fort Collins, CO 2. Department of Atmospheric Science, Colorado State University, Fort Collins, CO During summer months, the Northern Front Range Metropolitan Area (NFRMA) of Colorado consistently violates the 75 ppbv 8-hour EPA National Ambient Air Quality Standard (NAAQS) for ambient ozone (O3), despite continued reduction in anthropogenic emissions. The region has been deemed an O3 non-attainment zone since 2008. Ground-level O3 is produced from photochemical catalytic cycles involving OH radicals, volatile organic compounds (VOCs), and NOx (NO + NO2). VOC emissions in the NFRMA are dominated by anthropogenic sources and influenced by biogenic and agricultural sources, while NOx emissions are mainly from automobile exhaust. A growing concern in the region is the role of oil and natural gas (ONG) on VOC concentrations and the potential for O3 production. Increases in local VOC emissions will likely cause subsequent increase in local O3 concentrations as PO3 increases in a region that is already affected by high O3episodes. As a part of the SONGNEX 2015 (Shale Oil and Natural Gas Nexus) campaign, we measured a broad suite of speciated VOCs during two 8-week deployments (March-May 2015, July-September 2015) at the Boulder Atmospheric Observatory in Erie, CO. VOC measurements were made with a custom-online multichannel gas chromatography system (50+ compounds hourly), along with measurements of O3, SO2, NOx, NOy, PAN, CO, CO2, and CH4. We use these data to investigate the role of different VOC sources, and ONG in particular, in contributing to VOC reactivity and thus instantaneous O3 production. Preliminary analysis of the Spring VOC data indicates that VOC reactivity is dominated by light alkanes typical of ONG emissions - specifically propane, consistent with previous winter-time studies. We will use the observed temperature

  4. Changes in ozone and precursors during two aged wildfire smoke events in the Colorado Front Range in summer 2015

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    J. Lindaas


    Full Text Available The relative importance of wildfire smoke for air quality over the western US is expected to increase as the climate warms and anthropogenic emissions decline. We report on in situ measurements of ozone (O3, a suite of volatile organic compounds (VOCs, and reactive oxidized nitrogen species collected during summer 2015 at the Boulder Atmospheric Observatory (BAO in Erie, CO. Aged wildfire smoke impacted BAO during two distinct time periods during summer 2015: 6–10 July and 16–30 August. The smoke was transported from the Pacific Northwest and Canada across much of the continental US. Carbon monoxide and particulate matter increased during the smoke-impacted periods, along with peroxyacyl nitrates and several VOCs that have atmospheric lifetimes longer than the transport timescale of the smoke. During the August smoke-impacted period, nitrogen dioxide was also elevated during the morning and evening compared to the smoke-free periods. There were nine empirically defined high-O3 days during our study period at BAO, and two of these days were smoke impacted. We examined the relationship between O3 and temperature at BAO and found that for a given temperature, O3 mixing ratios were greater (∼ 10 ppbv during the smoke-impacted periods. Enhancements in O3 during the August smoke-impacted period were also observed at two long-term monitoring sites in Colorado: Rocky Mountain National Park and the Arapahoe National Wildlife Refuge near Walden, CO. Our data provide a new case study of how aged wildfire smoke can influence atmospheric composition at an urban site, and how smoke can contribute to increased O3 abundances across an urban–rural gradient.

  5. Changes in ozone and precursors during two aged wildfire smoke events in the Colorado Front Range in summer 2015 (United States)

    Lindaas, Jakob; Farmer, Delphine K.; Pollack, Ilana B.; Abeleira, Andrew; Flocke, Frank; Roscioli, Rob; Herndon, Scott; Fischer, Emily V.


    The relative importance of wildfire smoke for air quality over the western US is expected to increase as the climate warms and anthropogenic emissions decline. We report on in situ measurements of ozone (O3), a suite of volatile organic compounds (VOCs), and reactive oxidized nitrogen species collected during summer 2015 at the Boulder Atmospheric Observatory (BAO) in Erie, CO. Aged wildfire smoke impacted BAO during two distinct time periods during summer 2015: 6-10 July and 16-30 August. The smoke was transported from the Pacific Northwest and Canada across much of the continental US. Carbon monoxide and particulate matter increased during the smoke-impacted periods, along with peroxyacyl nitrates and several VOCs that have atmospheric lifetimes longer than the transport timescale of the smoke. During the August smoke-impacted period, nitrogen dioxide was also elevated during the morning and evening compared to the smoke-free periods. There were nine empirically defined high-O3 days during our study period at BAO, and two of these days were smoke impacted. We examined the relationship between O3 and temperature at BAO and found that for a given temperature, O3 mixing ratios were greater (˜ 10 ppbv) during the smoke-impacted periods. Enhancements in O3 during the August smoke-impacted period were also observed at two long-term monitoring sites in Colorado: Rocky Mountain National Park and the Arapahoe National Wildlife Refuge near Walden, CO. Our data provide a new case study of how aged wildfire smoke can influence atmospheric composition at an urban site, and how smoke can contribute to increased O3 abundances across an urban-rural gradient.

  6. Chloroplast DNA Phylogeography Reveals Repeated Range Expansion in a Widespread Aquatic Herb Hippuris vulgaris in the Qinghai-Tibetan Plateau and Adjacent Areas (United States)

    Sun, Shan-Shan; Gituru, Robert Wahiti; Wang, Qing-Feng


    Background The Qinghai-Tibetan Plateau (QTP) is one of the most extensive habitats for alpine plants in the world. Climatic oscillations during the Quaternary ice age had a dramatic effect on species ranges on the QTP and the adjacent areas. However, how the distribution ranges of aquatic plant species shifted on the QTP in response to Quaternary climatic changes remains almost unknown. Methodology and Principal Findings We studied the phylogeography and demographic history of the widespread aquatic herb Hippuris vulgaris from the QTP and adjacent areas. Our sampling included 385 individuals from 47 natural populations of H. vulgaris. Using sequences from four chloroplast DNA (cpDNA) non-coding regions, we distinguished eight different cpDNA haplotypes. From the cpDNA variation in H. vulgaris, we found a very high level of population differentiation (GST = 0.819) but the phylogeographical structure remained obscure (NST = 0.853>GST = 0.819, P>0.05). Phylogenetic analyses revealed two main cpDNA haplotype lineages. The split between these two haplotype groups can be dated back to the mid-to-late Pleistocene (ca. 0.480 Myr). Mismatch distribution analyses showed that each of these had experienced a recent range expansion. These two expansions (ca. 0.12 and 0.17 Myr) might have begun from the different refugees before the Last Glacial Maximum (LGM). Conclusions/Significance This study initiates a research on the phylogeography of aquatic herbs in the QTP and for the first time sheds light on the response of an alpine aquatic seed plant species in the QTP to Quaternary climate oscillations. PMID:23565290

  7. An Integrated Geophysical and Geological Investigation of the Transition Zone between the Colorado Plateau, Rio Grande Rift and Basin and Range Provinces: Arizona and New Mexico (United States)


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  8. Surface ozone in the Colorado northern Front Range and the influence of oil and gas development during FRAPPE/DISCOVER-AQ in summer 2014

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    L. C. Cheadle


    Full Text Available High mixing ratios of ozone (O3 in the northern Front Range (NFR of Colorado are not limited to the urban Denver area but were also observed in rural areas where oil and gas activity is the primary source of O3 precursors. On individual days, oil and gas O3 precursors can contribute in excess of 30 ppb to O3 growth and can lead to exceedances of the EPA O3 National Ambient Air Quality Standard. Data used in this study were gathered from continuous surface O3 monitors for June–August 2013–2015 as well as additional flask measurements and mobile laboratories that were part of the FRAPPE/DISCOVER-AQ field campaign of July–August 2014. Overall observed O3 levels during the summer of 2014 were lower than in 2013, likely due to cooler and damper weather than an average summer. This study determined the median hourly surface O3 mixing ratio in the NFR on summer days with limited photochemical production to be approximately 45–55 ppb. Mobile laboratory and flask data collected on three days provide representative case studies of different O3 formation environments in and around Greeley, Colorado. Observations of several gases (including methane, ethane, CO, nitrous oxide along with O3 are used to identify sources of O3 precursor emissions. A July 23 survey demonstrated low O3 (45–60 ppb while August 3 and August 13 surveys recorded O3 levels of 75–80 ppb or more. August 3 exemplifies influence of moderate urban and high oil and gas O3 precursor emissions. August 13 demonstrates high oil and gas emissions, low agricultural emissions, and CO measurements that were well correlated with ethane from oil and gas, suggesting an oil and gas related activity as a NOx and O3 precursor source. Low isoprene levels indicated that they were not a significant contributor to O3 precursors measured during the case studies.

  9. ;Inverted; zircon and apatite (U-Th)/He dates from the Front Range, Colorado: High-damage zircon as a low-temperature (<50 °C) thermochronometer (United States)

    Johnson, Joshua E.; Flowers, Rebecca M.; Baird, Graham B.; Mahan, Kevin H.


    Zircon (U-Th)/He (ZHe) data were acquired for 23 Proterozoic basement samples from an E-W transect through the Colorado Front Range to evaluate whether metamict zircons yield sensible (U-Th)/He data patterns and useful thermal history information. The 112 ZHe dates vary from 147 to 7 Ma, define positive and negative date-eU correlations, and are younger than titanite (U-Th)/He dates that range from 976 to 614 Ma. At moderate to high alpha dose of 1018-1019 α /g, zircons from the range core yield Laramide (52.5 ± 9.6 Ma) dates, whereas those within ∼15 km of the range front yield Miocene (21.6 ± 7.7 Ma) results. The He dates for the high alpha dose zircons are reproducible within each sample suite despite their visibly metamict character. The ∼20 Ma range front ZHe dates are younger than apatite (U-Th)/He (AHe) dates (66.5 ± 9.6 Ma) and published apatite fission-track data (65-45 Ma) for the same and nearby samples. Thermal history simulations can reproduce the first-order range front date-eU patterns and ZHe-AHe date inversion, but the high-damage zircons are more He retentive than predicted by the zircon damage He kinetic model. The ∼20 Ma ZHe dates may be explained by reheating from hydrothermal fluids along range front faults. The results demonstrate the promise of using He data for high-damage zircons to detect low-temperature (<50 °C) events within and below the temperature sensitivity of the AHe system.

  10. Spongiform encephalopathy in free-ranging mule deer (Odocoileus hemionus), white-tailed deer (Odocoileus virginianus) and Rocky Mountain elk (Cervus elaphus nelsoni) in northcentral Colorado. (United States)

    Spraker, T R; Miller, M W; Williams, E S; Getzy, D M; Adrian, W J; Schoonveld, G G; Spowart, R A; O'Rourke, K I; Miller, J M; Merz, P A


    Between March 1981 and June 1995, a neurological disease characterized histologically by spongiform encephalopathy was diagnosed in 49 free-ranging cervids from northcentral Colorado (USA). Mule deer (Odocoileus hemionus) were the primary species affected and accounted for 41 (84%) of the 49 cases, but six Rocky Mountain elk (Cervus elaphus nelsoni) and two white-tailed deer (Odocoileus virginianus) were also affected. Clinical signs included emaciation, excessive salivation, behavioral changes, ataxia, and weakness. Emaciation with total loss of subcutaneous and abdominal adipose tissue and serous atrophy of remaining fat depots were the only consistent gross findings. Spongiform encephalopathy characterized by microcavitation of gray matter, intraneuronal vacuolation and neuronal degeneration was observed microscopically in all cases. Scrapie-associated prion protein or an antigenically indistinguishable protein was demonstrated in brains from 26 affected animals, 10 using an immunohistochemical staining procedure, nine using electron microscopy, and seven using Western blot. Clinical signs, gross and microscopic lesions and ancillary test findings in affected deer and elk were indistinguishable from those reported in chronic wasting disease of captive cervids. Prevalence estimates, transmissibility, host range, distribution, origins, and management implications of spongiform encephalopathy in free-ranging deer and elk remain undetermined.

  11. On the contrasting decadal changes of diurnal surface temperature range between the Tibetan Plateau and southeastern China during the 1980s-2000s (United States)

    Yang, Yang; Ren, Rongcai


    The diurnal surface temperature range (DTR) has become significantly smaller over the Tibetan Plateau (TP) but larger in southeastern China, despite the daily mean surface temperature having increased steadily in both areas during recent decades. Based on ERA-Interim reanalysis data covering 1979-2012, this study shows that the weakened DTR over TP is caused by stronger warming of daily minimum surface temperature (Tmin) and a weak cooling of the daily maximum surface temperature (Tmax); meanwhile, the enhanced DTR over southeastern China is mainly associated with a relatively stronger/weaker warming of Tmax/Tmin. A further quantitative analysis of DTR changes through a process-based decomposition method—the Coupled Surface-Atmosphere Climate Feedback Response Analysis Method (CFRAM)—indicates that changes in radiative processes are mainly responsible for the decreased DTR over the TP. In particular, the increased low-level cloud cover tends to induce the radiative cooling/warming during daytime/nighttime, and the increased water vapor helps to decrease the DTR through the stronger radiative warming during nighttime than daytime. Contributions from the changes in all radiative processes (over -2°C) are compensated for by those from the stronger decreased surface sensible heat flux during daytime than during nighttime (approximately 2.5°C), but are co-contributed by the changes in atmospheric dynamics (approximately -0.4°C) and the stronger increased latent heat flux during daytime (approximately -0.8°C). In contrast, the increased DTR over southeastern China is mainly contributed by the changes in cloud, water vapor and atmospheric dynamics. The changes in surface heat fluxes have resulted in a decrease in DTR over southeastern China.

  12. Summer-fall home-range fidelity of female elk in northwestern Colorado: Implications for aspen management (United States)

    April M. Brough; R. Justin DeRose; Mary M. Conner; James N. Long


    Understanding the degree of spatial fidelity exhibited by individuals within a species increases our ability to manage for desired future outcomes. Elk (Cervus elaphus) is a closely managed species in the Western US, but there is little research evaluating their summer home-range fidelity. Elk summer-fall homeranges overlap considerably with aspen (Populus tremuloides...

  13. Watershed management problems and opportunities for the Colorado Front Range ponderosa pine zone: The status of our knowledge (United States)

    Howard L. Gary


    The east flank of the Continental Divide consists largely of open timber stands and grasslands. Soils erode easily after abuse. Precipitation ranges from 15 to 20 inches, about two-thirds from high-intensity storms from April to September. Guidelines are provided for maintaining satisfactorv watershed conditions. The 3- to 5-inch water yields are comparatively small in...

  14. Investigation of the influence of transport from oil and natural gas regions on elevated ozone levels in the northern Colorado front range. (United States)

    Evans, Jason M; Helmig, Detlev


    The Northern Colorado Front Range (NCFR) has been in exceedance of the ozone National Ambient Air Quality Standard (NAAQS) since 2004, which has led to much debate over the sources of ozone precursors to the region, as this area is home to both the Denver, CO, metropolitan area and the Denver-Julesburg Basin, which has experienced rapid growth of oil and natural gas (O&NG) operations and associated emissions. Several recent studies have reported elevated levels of atmospheric volatile organic compounds (VOCs) as a result of O&NG emissions and the potential for significant ozone production from these emissions, despite implementation of stricter O&NG VOC emissions regulations in 2008. Approximately 88% of 1-hr elevated ozone events (>75 ppbv) occur during June-August, indicating that elevated ozone levels are driven by regional photochemistry. Analyses of surface ozone and wind observations from two sites, namely, South Boulder and the Boulder Atmospheric Observatory, both near Boulder, CO, show a preponderance of elevated ozone events associated with east-to-west airflow from regions with O&NG operations in the N-ESE, and a relatively minor contribution of transport from the Denver Metropolitan area to the SE-S. Transport from upwind areas associated with abundant O&NG operations accounts for on the order of 65% (mean for both sites) of 1-hr averaged elevated ozone levels, while the Denver urban corridor accounts for 9%. These correlations contribute to mounting evidence that air transport from areas with O&NG operation has a significant impact on ozone and air quality in the NCFR. This article builds on several previous pieces of research that implied significant contributions from oil and natural gas emissions on ozone production in the Northern Colorado Front Range. By correlating increased ozone events with transport analyses we show that there is a high abundance of transport events with elevated ozone originating from the Denver-Julesburg oil and natural gas

  15. Climate and tectonic variability during Late Quaternary in western fringe of Tibetan Plateau: case study from Trans-Himalayan ranges of Ladakh, NW India (United States)

    Phartiyal, B.


    The climate system plays an important role in the geomorphological dynamics of a region. The cold, arid, high altitude, tectonically active areas of Ladakh (India) in Trans Himalaya, western Tibetan Plateau is none exception. Noticeable change in the landscape with a shift from fluvial to lacustrine regime at 10000 yrs BP forming big open valley lakes occupying the present day river valleys is attributed to the early Holocene northward advancement of the mean latitudinal position of the summer ITCZ causing wetter conditions in this dry area. The glaciers of the Ladakh range are almost depleted and the northern range glaciers show andrastic retreat in the Quaternary time. Lakes were studied using multi-proxies, to record centennial and decadal scale climatic variability. Spatial and temporal setting of Spituk palaeolake (12600-240 cal yrs BP) along Indus River, was analyzed using multi proxies. The lake that extended for 40-50 km covering an area of 106 km2, was formed after Older Dryas as a result of river blockage by precipitation induced debris flow and seismicity. Two lake phases between 12600-9000 and 5500-3200 cal yrs BP show stable lake conditions and have synchronous relationship between high variation in monsoon intensity, high δ18O values in the Guliya core, rise in temperature and high solar insolation. High magnetic susceptibility and clay content along with diversified diatom and other freshwater algae and land derived organic matter are indicative of fresh water supply leading to high lake level from 4700 yr BP onwards in the present pro-glacial lakes studied. The multi-proxy data provides evidence of much higher and stable lake level during 3700 yr BP and 3000 yr BP onwards due to high water supply in these lake. It is in contrast to the records of weak ISM conditions and low lake level in rest of the part of Indian peninsula during the period. The study also suggests strong western disturbance activity during 4800-3000 yr BP leading to high lake

  16. Aerosol optical extinction during the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ) 2014 summertime field campaign, Colorado, USA (United States)

    Dingle, Justin H.; Vu, Kennedy; Bahreini, Roya; Apel, Eric C.; Campos, Teresa L.; Flocke, Frank; Fried, Alan; Herndon, Scott; Hills, Alan J.; Hornbrook, Rebecca S.; Huey, Greg; Kaser, Lisa; Montzka, Denise D.; Nowak, John B.; Reeves, Mike; Richter, Dirk; Roscioli, Joseph R.; Shertz, Stephen; Stell, Meghan; Tanner, David; Tyndall, Geoff; Walega, James; Weibring, Petter; Weinheimer, Andrew


    Summertime aerosol optical extinction (βext) was measured in the Colorado Front Range and Denver metropolitan area as part of the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ) campaign during July-August 2014. An Aerodyne cavity attenuated phase shift particle light extinction monitor (CAPS-PMex) was deployed to measure βext (at average relative humidity of 20 ± 7 %) of submicron aerosols at λ = 632 nm at 1 Hz. Data from a suite of gas-phase instrumentation were used to interpret βext behavior in various categories of air masses and sources. Extinction enhancement ratios relative to CO (Δβext / ΔCO) were higher in aged urban air masses compared to fresh air masses by ˜ 50 %. The resulting increase in Δβext / ΔCO for highly aged air masses was accompanied by formation of secondary organic aerosols (SOAs). In addition, the impacts of aerosol composition on βext in air masses under the influence of urban, natural oil and gas operations (O&G), and agriculture and livestock operations were evaluated. Estimated non-refractory mass extinction efficiency (MEE) values for different air mass types ranged from 1.51 to 2.27 m2 g-1, with the minimum and maximum values observed in urban and agriculture-influenced air masses, respectively. The mass distribution for organic, nitrate, and sulfate aerosols presented distinct profiles in different air mass types. During 11-12 August, regional influence of a biomass burning event was observed, increasing the background βext and estimated MEE values in the Front Range.

  17. Aerosol optical extinction during the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ 2014 summertime field campaign, Colorado, USA

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    J. H. Dingle


    Full Text Available Summertime aerosol optical extinction (βext was measured in the Colorado Front Range and Denver metropolitan area as part of the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ campaign during July–August 2014. An Aerodyne cavity attenuated phase shift particle light extinction monitor (CAPS-PMex was deployed to measure βext (at average relative humidity of 20 ± 7 % of submicron aerosols at λ = 632 nm at 1 Hz. Data from a suite of gas-phase instrumentation were used to interpret βext behavior in various categories of air masses and sources. Extinction enhancement ratios relative to CO (Δβext ∕ ΔCO were higher in aged urban air masses compared to fresh air masses by  ∼  50 %. The resulting increase in Δβext ∕ ΔCO for highly aged air masses was accompanied by formation of secondary organic aerosols (SOAs. In addition, the impacts of aerosol composition on βext in air masses under the influence of urban, natural oil and gas operations (O&G, and agriculture and livestock operations were evaluated. Estimated non-refractory mass extinction efficiency (MEE values for different air mass types ranged from 1.51 to 2.27 m2 g−1, with the minimum and maximum values observed in urban and agriculture-influenced air masses, respectively. The mass distribution for organic, nitrate, and sulfate aerosols presented distinct profiles in different air mass types. During 11–12 August, regional influence of a biomass burning event was observed, increasing the background βext and estimated MEE values in the Front Range.

  18. Northward range expansion requires synchronization of both overwintering behaviour and physiology with photoperiod in the invasive Colorado potato beetle (Leptinotarsa decemlineata). (United States)

    Lehmann, Philipp; Lyytinen, Anne; Piiroinen, Saija; Lindström, Leena


    Photoperiodic phenological adaptations are prevalent in many organisms living in seasonal environments. As both photoperiod and growth season length change with latitude, species undergoing latitudinal range expansion often need to synchronize their life cycle with a changing photoperiod and growth season length. Since adaptive synchronization often involves a large number of time-consuming genetic changes, behavioural plasticity might be a faster way to adjust to novel conditions. We compared behavioural and physiological traits in overwintering (diapause) preparation in three latitudinally different European Colorado potato beetle (Leptinotarsa decemlineata) populations reared under two photoperiods. Our aim was to study whether behavioural plasticity could play a role in rapid range expansion into seasonal environments. Our results show that while burrowing into the soil occurred in the southernmost studied population also under a non-diapause-inducing long photoperiod, the storage lipid content of these beetles was very low compared to the northern populations. However, similar behavioural plasticity was not found in the northern populations. Furthermore, the strongest suppression of energy metabolism was seen in pre-diapause beetles from the northernmost population. These results could indicate accelerated diapause preparation and possibly energetic adjustments due to temporal constraints imposed by a shorter, northern, growth season. Our results indicate that behavioural plasticity in burrowing may have facilitated initial range expansion of L. decemlineata in Europe. However, long-term persistence at high latitudes has required synchronization of burrowing behaviour with physiological traits. The results underline that eco-physiological life-history traits of insects, such as diapause, should be included in studies on range expansion.

  19. Assessing the role of large wood entrained in the 2013 Colorado Front Range flood in ongoing channel response and reservoir management (United States)

    Bennett, Georgina; Rathburn, Sara; Ryan, Sandra; Wohl, Ellen; Blair, Aaron


    Considerable quantities of large wood (LW) may be entrained during floods with long lasting impacts on channel morphology, sediment and LW export, and downstream reservoir management. Here we present an analysis of LW entrained by an extensive flood in Colorado, USA. Over a 5 day period commencing 9th September 2013, up to 450 mm of rain, or ~1000% of the monthly average, fell in catchments spanning a 100-km-wide swath of the Colorado Front Range resulting in major flooding. Catchment response was dramatic, with reports of 100s - 1000s of years of erosion, destruction of infrastructure and homes, and sediment and LW loading within reservoirs. One heavily impacted catchment is the North St Vrain, draining 250km2 of the South Platte drainage basin. In addition to widespread channel enlargement, remote imagery reveals hundreds of landslides that delivered sediment and LW to the channel and ultimately to Ralph Price Reservoir, which provides municipal water to Longmont. The City of Longmont facilitated the removal of ~1050 m3 of wood deposited at the reservoir inlet by the flood but the potential for continued movement of large wood in the catchment presents an on-going concern for reservoir management. In collaboration with the City of Longmont, our objectives are (1) to quantify the volume of wood entrained by the flood and still stored along the channel, (2) characterize the size and distribution of LW deposits and (3) determine their role in ongoing catchment flood response and recovery. We utilize freely available pre and post flood NAIP 4-band imagery to calculate a normalized differential vegetation index (NDVI) difference map with which we calculate the area of vegetation entrained by the flood. We combine this with field assessments and a map of vegetation type automatically classified from optical satellite imagery to estimate the total flood-entrained volume of wood. Preliminary testing of 'stream selfies' - structure from motion imaging of LW deposits using

  20. Douglas-Fir Tussock Moth- and Douglas-Fir Beetle-Caused Mortality in a Ponderosa Pine/Douglas-Fir Forest in the Colorado Front Range, USA

    Directory of Open Access Journals (Sweden)

    José F. Negrón


    Full Text Available An outbreak of the Douglas-fir tussock moth, Orgyia pseudotsugata McDunnough, occurred in the South Platte River drainage on the Pike-San Isabel National Forest in the Colorado Front Range attacking Douglas-fir, Pseudotsuga menziesii (Mirb. Franco. Stocking levels, species composition, and tree size in heavily and lightly defoliated stands were similar. Douglas-fir tussock moth defoliation resulted in significant Douglas-fir mortality in the heavily defoliated stands, leading to a change in dominance to ponderosa pine, Pinus ponderosa Lawson. Douglas-fir beetle, Dendroctonus pseudotsuqae Hopkins, populations increased following the defoliation event but caused less mortality, and did not differ between heavily and lightly defoliated stands. Douglas-fir tussock moth-related mortality was greatest in trees less than 15 cm dbh (diameter at 1.4 m above the ground that grew in suppressed and intermediate canopy positions. Douglas-fir beetle-related mortality was greatest in trees larger than 15 cm dbh that grew in the dominant and co-dominant crown positions. Although both insects utilize Douglas-fir as its primary host, stand response to infestation is different. The extensive outbreak of the Douglas-fir tussock moth followed by Douglas-fir beetle activity may be associated with a legacy of increased host type growing in overstocked conditions as a result of fire exclusion.

  1. U-Pb ages and geochemistry of zircon from Proterozoic plutons of the Sawatch and Mosquito ranges, Colorado, U.S.A.: Implications for crustal growth of the central Colorado province (United States)

    Moscati, Richard J.; Premo, Wayne R.; Dewitt, Ed; Wooden, Joseph L.


    A broad study of zircons from plutonic rocks of the Sawatch and Mosquito ranges of west-central Colorado (U.S.A.) was undertaken to significantly refine the magmatic chronology and chemistry of this under-studied region of the Colorado province. This region was chosen because it lies just to the north of the suspected arc-related Gunnison-Salida volcano-plutonic terrane, which has been the subject of many recent investigations—and whose origin is still debated. Our new results provide important insights into the processes active during Proterozoic crustal evolution in this region, and they have important ramifications for broader-scope crustal evolution models for southwestern North America.Twenty-four new U-Pb ages and sequentially acquired rare-earth element (REE), U, Th, and Hf contents of zircon have been determined using the sensitive high-resolution ion microprobe-reverse geometry (SHRIMP-RG). These zircon geochemistry data, in conjunction with whole-rock major- and trace-element data, provide important insights into zircon crystallization and melt fractionation, and they help to further constrain the tectonic environment of magma generation.Our detailed zircon and whole-rock data support the following three interpretations:(1) The Roosevelt Granite in the southern Sawatch Range was the oldest rock dated at 1,766 ± 7 Ma, and it intruded various metavolcanic and metasedimentary rocks. Geochemistry of both whole-rock and zircon supports the contention that this granite was produced in a magmatic arc environment and, therefore, is likely an extension of the older Dubois Greenstone Belt of the Gunnison Igneous Complex (GIC) and the Needle Mountains (1,770–1,755 Ma). Rocks of the younger Cochetopa succession of the GIC, the Salida Greenstone Belt, and the Sangre de Cristo Mountains (1,740–1,725 Ma) were not found in the Sawatch and Mosquito ranges. This observation strongly suggests that the northern edge of the Gunnison-Salida arc terrane underlies the

  2. Gopher eskers, mounds, and stonelines: Evidence of the annual to centennial impacts of gophers in the montane meadows of Colorado's Front Range (United States)

    Winchell, E. W.; Lombardi, E. M.; Marquez, J. A.; Doak, D. F.; Anderson, R. S.


    Within the critical zone on montane hillslopes of Colorado's Front Range, qualitative observations suggest that gophers not only dominate the modern meadow geomorphic rates, but are involved in a geomorphic-ecological feedback system that governs meadow migration on decadal-millennial time scales. Our observations suggest that gopher intensity and location is pertinent to forest/meadow (FM) dynamics. Field mapping of gopher activity as the snow melts in the spring revealed that subnivean tubes ("eskers") are tightly clustered at the FM boundary while mounds generated over the remainder of the summer are concentrated strictly in the meadows. This suggests that gophers spend the winter months at the FM interface and spend the warmer seasons within the meadows. We hypothesize that variations in snow depth drive this spatial-temporal pattern of gopher activity; deeper snow near the FM boundary provides greater insulation, as near-surface ground temperatures in the wind-scoured meadow centers are colder. This motivates our initiation of monitoring and modeling of near-surface temperature across a FM pair. Numerical modeling supports qualitative observations that the following geomorphic-ecological processes are active: seedling establishment and damage, gopher tunneling and resulting mound generation, mound material transport driven by ungulate trampling, vegetative lock-down of mound material, and resulting changes in the soil depth of the landscape. This year's observations suggest that we must add to this mix the annual cycle of the gopher activity. Finally, probing and soil pits within the meadows reveal that on longer timescales gopher activity leads to the development of a well-mixed upper soil layer that is sharply bounded below by high concentrations of large stones ("stone lines") within the glacial till substrate of the hillslopes. The mean diameter of mound surface grains is half that of clasts comprising the stone lines. This motivates documentation of soil

  3. Petrology of arkosic sandstones, Pennsylvanian Minturn Formation and Pennsylvanian and Permian Sangre de Cristo Formation, Sangre de Cristo Range, Colorado - data and preliminary interpretations (United States)

    Lindsey, D.A.


    This report describes the mineral and chemical composition of immature, arkosic sandstones of the Pennsylvanian Minturn and Pennsylvanian and Permian Sangre de Cristo Formations, which were derived from the Ancestral Rocky Mountains. Located in the Sangre de Cristo Range of southern Colorado, the Minturn and Sangre de Cristo Formations contain some of the most immature, sodic arkoses shed from the Ancestral Rocky Mountains. The Minturn Formation was deposited as fan deltas in marine and alluvial environments; the Sangre de Cristo Formation was deposited as alluvial fans. Arkoses of the Minturn and Sangre de Cristo Formations are matrix-rich and thus may be properly considered arkosic wackes in the terminology of Gilbert (Williams and others, 1954). In general, potassium feldspar and plagioclase are subequal in abundance. Arkose of the Sangre de Cristo Formation is consistently plagioclase-rich; arkose from the Minturn Formation is more variable. Quartz and feldspar grains are accompanied by a few percent rock fragments, consisting mostly of intermediate to granitic plutonic rocks, gneiss, and schist. All of the rock fragments seen in sandstone are present in interbedded conglomerate, consistent with derivation from a Precambrian terrane of gneiss and plutonic rocks much like that exposed in the present Sangre de Cristo Range. Comparison of mineral and major oxide abundances reveals a strong association of detrital quartz with SiO2, all other detrital minerals (totaled) with Al2O3, potassium feldspar plus mica with K2O, and plagioclase with Na2O. Thus, major oxide content is a good predictor of detrital mineralogy, although contributions from matrix and cement make these relationships less than perfect. Detrital minerals and major oxides tend to form inverse relationships that reflect mixtures of varying quantities of minerals; when one mineral is abundant, the abundance of others declines by dilution. In arkose of the Minturn and Sangre de Cristo Formations, the

  4. Use of cosmogenic 35S for comparing ages of water from three alpine-subalpine basins in the Colorado Front Range (United States)

    Sueker, J.K.; Turk, J.T.; Michel, R.L.


    High-elevation basins in Colorado are a major source of water for the central and western United States; however, acidic deposition may affect the quality of this water. Water that is retained in a basin for a longer period of time may be less impacted by acidic deposition. Sulfur-35 (35S), a short-lived isotope of sulfur (t( 1/2 ) = 87 days), is useful for studying short-time scale hydrologic processes in basins where biological influences and water/rock interactions are minimal. When sulfate response in a basin is conservative, the age of water may be assumed to be that of the dissolved sulfate in it. Three alpine-subalpine basins on granitic terrain in Colorado were investigated to determine the influence of basin morphology on the residence time of water in the basins. Fern and Spruce Creek basins are glaciated and accumulate deep snowpacks during the winter. These basins have hydrologic and chemical characteristics typical of systems with rapid hydrologic response times. The age of sulfate leaving these basins, determined from the activity of 35S, averages around 200 days. In contrast, Boulder Brook basin has broad, gentle slopes and an extensive cover of surficial debris. Its area above treeline, about one-half of the basin, is blown free of snow during the winter. Variations in flow and solute concentrations in Boulder Brook are quite small compared to Fern and Spruce Creeks. After peak snowmelt, sulfate in Boulder Brook is about 200 days older than sulfate in Fern and Spruce Creeks. This indicates a substantial source of older sulfate (lacking 35S) that is probably provided from water stored in pore spaces of surficial debris in Boulder Brook basin.

  5. Geologic map of Colorado National Monument and adjacent areas, Mesa County, Colorado (United States)

    Scott, Robert B.; Harding, Anne E.; Hood, William C.; Cole, Rex D.; Livaccari, Richard F.; Johnson, James B.; Shroba, Ralph R.; Dickerson, Robert P.


    New 1:24,000-scale geologic mapping in the Colorado National Monument Quadrangle and adjacent areas, in support of the USGS Western Colorado I-70 Corridor Cooperative Geologic Mapping Project, provides new interpretations of and data for the stratigraphy, structure, geologic hazards in the area from the Colorado River in Grand Valley onto the Uncompahgre Plateau. The plateau drops abruptly along northwest-trending structures toward the northeast 800 m to the Redlands area and the Colorado River in Grand Valley. In addition to common alluvial and colluvial deposits, surficial deposits include Holocene and late Pleistocene charcoal-bearing valley-fill deposits, late to middle Pleistocene river-gravel terrace deposits, Holocene to middle Pleistocene younger, intermediate, and old fan-alluvium deposits, late to middle Pleistocene local gravel deposits, Holocene to late Pleistocene rock-fall deposits, Holocene to middle Pleistocene young and old landslide deposits, Holocene to late Pleistocene sheetwash deposits and eolian deposits, and Holocene Cienga-type deposits. Only the lowest part of the Upper Cretaceous Mancos Shale is exposed in the map area near the Colorado River. The Upper and Lower? Cretaceous Dakota Formation and the Lower Cretaceous Burro Canyon Formation form resistant dipslopes in the Grand Valley and a prominent ridge on the plateau. Less resistant strata of the Upper Jurassic Morrison Formation consisting of the Brushy Basin, Salt Wash, and Tidwell Members form slopes on the plateau and low areas below the mountain front of the plateau. The Middle Jurassic Wanakah Formation nomenclature replaces the previously used Summerville Formation. Because an upper part of the Middle Jurassic Entrada Formation is not obviously correlated with strata found elsewhere, it is therefore not formally named; however, the lower rounded cliff former Slickrock Member is clearly present. The Lower Jurassic silica-cemented Kayenta Formation forms the cap rock for the Lower

  6. Colorado amethyst. (United States)

    Michalski, T.C.


    Of the 20 or so amethyst localities reported in Colorado, four are described in some detail and comments are given on their geology. The Crystal Hill mine, near La Garita, Saguache County, contains rock crystal (long slender prisms with small rhombohedral terminations) and pale lavender amethyst (generally Unaweep Canyon south of Grand Junction in Mesa County. Pale to very dark amethyst occurs as crystals dominated by large rhombohedra and small prisms (approx 1 in. across). At Red Feather Lakes, Larimer County, amethyst crystals are medium to dark purple and have prism and rhombohedral faces nearly equally developed; some are doubly terminated. -R.S.M.

  7. Water temperature and baseflow discharge of streams throughout the range of Rio Grande cutthroat trout in Colorado and New Mexico—2010 and 2011 (United States)

    Zeigler, Matthew P.; Todd, Andrew S.; Caldwell, Colleen A.


    This study characterized the thermal regime in a number of Colorado and New Mexico streams that contain populations of Rio Grande cutthroat trout (Oncorhynchus clarkii virginalis) and had no previous record of continual temperature records. When compared to Colorado’s water temperature criteria (Cold Tier 1), a portion of these populations appeared to be at risk from elevated stream temperatures, as indicated by exceedance of both acute (17–22 percent) and chronic (2–9 percent) water quality metrics. Summer water temperature profiles recorded at sites within current Rio Grande cutthroat trout habitat indicated that although the majority of currently occupied conservation streams have temperatures that fall well below these biologically based acute and chronic thermal thresholds, several sites may be at or approaching water temperatures considered stressful to cutthroat trout. Further, water temperatures should be considered in decisions regarding the current and future thermal suitability of potential Rio Grande cutthroat trout restoration sites. Additionally, baseflow discharge sampling indicated that a majority of the sampled stream segments containing Rio Grande cutthroat trout have flows less than 1.0 cubic feet per second (cfs) in both 2010 (74 percent) and 2011 (77 percent). The relative drought sensitivity of these low baseflow streams containing Rio Grande cutthroat trout could be further evaluated to assess their probable sustainability under possible future drought conditions.

  8. Living with wildfire in Colorado (United States)

    Patricia A. Champ; Nicholas Flores; Hannah Brenkert-Smith


    In this presentation, we describe results of a survey to homeowners living in wildfire-prone areas of two counties along the Front Range of the Rocky Mountains in Colorado. The survey was designed to elicit information on homeowners' experience with wildfire, perceptions of wildfire risk on their property and neighboring properties, mitigation efforts undertaken...

  9. CRevolution 2—Origin and evolution of the Colorado River system, workshop abstracts (United States)

    Beard, L. Sue; Karlstrom, Karl E.; Young, Richard A.; Billingsley, George H.


    A 2010 Colorado River symposium, held in Flagstaff, Arizona, involved 70 participants who engaged in intense debate about the origin and evolution of the Colorado River system. This symposium, built upon two previous decadal scientific meetings, focused on forging scientific consensus, where possible, while articulating continued controversies regarding the Cenozoic evolution of the Colorado River System and the landscapes of the Colorado Plateau-Rocky Mountain region that it drains. New developments involved hypotheses that Neogene mantle flow is driving plateau tilting and differential uplift and new and controversial hypotheses for the pre-6 Ma presence and evolution of ancestral rivers that may be important in the history and birth of the present Colorado River. There is a consensus that plateau tilt and uplift models must be tested with multidisciplinary studies involving differential incision studies and additional geochronology and thermochronology to determine the relative importance of tectonic and geomorphic forces that shape the spectacular landscapes of the Colorado Plateau, Arizona and region. In addition to the scientific goals, the meeting participants emphasized the iconic status of Grand Canyon for geosciences and the importance of good communication between the research community, the geoscience education/interpretation community, the public, and the media. Building on a century-long tradition, this region still provides a globally important natural laboratory for studies of the interactions of erosion and tectonism in shaping the landscape of elevated plateaus.

  10. Stratigraphic sections, depositional environments, and metal content of the upper part of the Middle Pennsylvanian Minturn Formation, Northern Sangre De Cristo Range, Custer and Saguache counties, Colorado (United States)

    Clark, R.F.; Walz, D.M.


    The calcareous upper part of the 2,000-meter-thick Middle Pennsylvanian Minturn Formation (Lindsey and others, 1985) in the northern Sangre de Cristo Range is a key stratigraphic interval for correlating rocks and mapping the structure of the range. The stratigraphy of this complex and heretofore poorly known interval is reported here in order to provide a basis for correlation among the structural blocks in the range. Inferred depositional environments of the upper part of the Minturn Formation are described briefly.


    Energy Technology Data Exchange (ETDEWEB)

    Knoff, E.N.; Peterson, R.S.


    Through QuarkNet, students across the country have access to cosmic ray detectors in their high school classrooms. These detectors operate using a scintillator material and a photomultiplier tube (PMT). A data acquisition (DAQ) board counts cosmic ray hits from the counters. Through an online e-Lab, students can analyze and share their data. In order to collect viable data, the PMTs should operate at their plateau voltages. In these plateau ranges, the number of counts per minute remains relatively constant with small changes in PMT voltage. We sought to plateau the counters in the test array and to clarify the plateauing procedure itself. In order to most effectively plateau the counters, the counters should be stacked and programmed to record the number of coincident hits as well as their singles rates. We also changed the threshold value that a signal must exceed in order to record a hit and replateaued the counters. For counter 1, counter 2, and counter 3, we found plateau voltages around 1V. The singles rate plateau was very small, while the coincidence plateau was very long. The plateau voltages corresponded to a singles rate of 700–850 counts per minute. We found very little effect of changing the threshold voltages. Our chosen plateau voltages produced good performance studies on the e-Lab. Keeping in mind the nature of the experiments conducted by the high school students, we recommend a streamlined plateauing process. Because changing the threshold did not drastically affect the plateau voltage or the performance study, students should choose a threshold value, construct plateau graphs, and analyze their data using a performance study. Even if the counters operate slightly off their plateau voltage, they should deliver good performance studies and return reliable results.

  12. Plan for the uniform mapping of earth resources and environmental complexes from Skylab imagery. Assessment of natural vegetation, environmental, and crop analogs. [Sierra-Lahontan, Colorado Plateau, Louisiana coastal plain, and Northern Great Valley, California (United States)

    Poulton, C. E. (Principal Investigator); Welch, R. I.


    The author has identified the following significant results. For interpreting a wide range of natural vegetation analogs, S-190A color infrared and the ERTS-1 color composite were consistently more useful than were conventional color or black and white photos. Color infrared was superior for five vegetation analogs while color was superior for only three. The errors in identification appeared to associate more with black and white single band images than with multiband color. For rice crop analogs, spectral and spatial discriminations both contribute to the usefulness of images for data collection. Tests and subjective analyses conducted in this study indicated that the spectral bands exploited in color infrared film were the most useful for agricultural crop analysis. Accuracy of crop identification on any single date of Skylab images was less than that of multidate analysis due to differences in crop calendar, cultural practices used, rice variety, planting date, planting method, water use, fertilization, disease, or mechanical problems.

  13. Analysis of Basin-Range Coupling Mechanisms during Epeirogenetic Uplift - A Case Study of Tectonic Coupling in the Songpan-Ganzi Plateau-Longmen Mountain-Sichuan Basin Region (United States)

    Ying, Danlin; Li, Ying


    The tectonodynamic evolution of the Songpan-Ganzi Plateau-Longmen Mountain-Sichuan basin region has been analyzed in this paper. The result suggested that the region had experienced principal four stages of evolution. The evolution was beginning with crystalline basement and folded basement formation in the pre-Sinian, then the cartonmarine sedimentary basin from the Sinian to the Middle Triassic was followed by uplift and stretching of the land from the Late Triassic to the Middle Jurassic, and finally compressive orogenesis since the Late Jurassic was happened. To understand the uplift and stretching of the land from the Late Triassic to the Middle Jurassic, a physical modeling experiment was conducted. It was confirmed that a tectonic plateau-ramp-basin geomorphology pattern developed during this period, caused by the wide difference in uplift between the Songpan-Ganzi Plateau and the Sichuan Basin. In the plateau region, the tectonic dynamic environment of uplift and stretching of the land (trailing edge extension) had appeared, which was accompany with the extensional structure styles such as normal faults and graben-horst structures. On the slope between the plateau and the basin, a bedding shear geodynamic environment was formed, and compressive slumped overthrust structure was found for the sliddown of decollement layers under the force of gravity. In the basin, compressive tectonic dynamic environment had emerged, which leaded to a compressive structure, such as thrust faults, overturned folds, and fault-related folds.

  14. Tibial Plateau Fractures

    DEFF Research Database (Denmark)

    Elsøe, Rasmus

    This PhD thesis reported an incidence of tibial plateau fractures of 10.3/100,000/year in a complete Danish regional population. The results reported that patients treated for a lateral tibial plateau fracture with bone tamp reduction and percutaneous screw fixation achieved a satisfactory level...... with only the subgroup Sport significantly below the age matched reference population. The thesis reports a level of health related quality of life (Eq5d) and disability (KOOS) significantly below established reference populations for patients with bicondylar tibial plateau fracture treated with a ring...... fixator, both during treatment and at 19 months following injury. In general, the thesis demonstrates that the treatment of tibial plateau fractures are challenging and that some disabilities following these fractures must be expected. Moreover, the need for further research in the area, both with regard...

  15. Measured sections and discussion of the main turbidite member, Middle Pennsylvanian Minturn Formation, northern Sangre de Cristo Range, Custer and Saguache counties, Colorado (United States)

    Soulliere, S.J.; DeAngelis, B.L.; Lindsey, D.A.


    Turbidites are sediments deposited by turbid density currents. The turbidites described here are interpreted as prodelta deposits that formed in front of fan deltas and alluvial fans during the uplift of the ancestral Rocky Mountains in Pennsylvanian time. Laterally extensive, lenticular sand bodies deposited by turbidity flows crop out in the Middle Pennsylvanian Minturn Formation in the northern Sangre de Crísto Range, Custer and Saguache Counties, Colo. (figs. 1, 2). One of the turbidite-bearing intervals, informally designated the "main turbidite member," lies 90.6 m above the base of the Minturn; it reaches 150 m in thickness and extends more than 13 km along strike. The internal stratigraphy and sedimentary structures of the main turbidite member are described from the measured sections presented here.

  16. Insights into the crustal structure and magmatic evolution of the High and Western Plateau of the Manihiki Plateau, Central Pacific (United States)

    Hochmuth, Katharina; Gohl, Karsten; Uenzelmann-Neben, Gabriele


    The Manihiki Plateau is a Large Igneous Province (LIP) located in the Central Pacific. It is assumed, that the formation of the Manihiki Plateau took place during the early Cretaceous in multiple volcanic stages as part of the "Super-LIP" Ontong-Java-Nui. The plateau consists of several sub-plateaus of which the Western Plateau und High Plateau are the largest. In addressing the plateau's magmatic evolutionary history, one of the key questions is whether all sub-plateaus experienced the same magmatic history or if distinct phases of igneous or tectonic processes led to its fragmentation. During the RV Sonne cruise SO-224 in 2012; we collected two deep crustal seismic refraction/wide-angle reflection lines, crossing the two main sub-plateaus. Modeling of P- and S-wave phases reveals the different crustal nature of both sub-plateaus. On the High Plateau, the 20 km thick crust is divided into four seismic units, interpreted to range from basaltic composition in the uppermost crust to peridotitic composition in the middle and lower crust. The Western Plateau on the other hand shows multiple rift structures and no indications of basalt flows. With a maximum of 17 km crustal thickness, the Western Plateau is also thinner than the High Plateau. The upper basement layers show relatively low P-wave velocities (3.0 - 5.0 km/s), which infers that on the Western Plateau these layers consist of volcanoclastic and carbonatic rocks rather than basaltic flow units. Later volcanic stages may be restricted to the High Plateau with a possible eastward trend in the center of volcanic activity. Extensive secondary volcanism does not seem to have occurred on the Western Plateau, and its later deformation is mainly caused by tectonic extension and rifting.

  17. Colorado Plateau Rapid Ecoregion Assessment Indicators: Natural Vegetation Fragmentation (United States)

    Bureau of Land Management, Department of the Interior — This dataset presents measures of landscape fragmentation calculated by FRAGSTATS at 4KM and HUC5 reporting unit levels. Fragmentation integrates the influence of...

  18. Experimental Design Plant and Soil Measurement Data, Colorado Plateau, 2011 (United States)

    U.S. Geological Survey, Department of the Interior — These plant and soil data were collected by Timothy M. Wertin and Sasha C. Reed in the spring, summer, and fall of 2011 at a climate manipulation experiment site...

  19. A native plant development program for the Colorado Plateau (United States)

    Stephen B. Monsen


    (Please note, this is an abstract only) Revegetation programs instigated in the Intermountain West have relied on the use of introduced perennial grasses, with attention focused upon improving the agronomic and forage attributes of these species. Currently, a wide number of site adapted native species are required to restore the extensive disturbances throughout the...

  20. Apparent field safety of a raccoon poxvirus-vectored plague vaccine in free-ranging prairie dogs (Cynomys spp.), Colorado, USA. (United States)

    Tripp, Daniel W; Rocke, Tonie E; Streich, Sean P; Abbott, Rachel C; Osorio, Jorge E; Miller, Michael W


    Prairie dogs (Cynomys spp.) suffer high rates of mortality from plague. An oral sylvatic plague vaccine using the raccoon poxvirus vector (designated RCN-F1/V307) has been developed for prairie dogs. This vaccine is incorporated into palatable bait along with rhodamine B as a biomarker. We conducted trials in August and September 2012 to demonstrate uptake and apparent safety of the RCN-F1/V307 vaccine in two prairie dog species under field conditions. Free-ranging prairie dogs and other associated small rodents readily consumed vaccine-laden baits during field trials with no apparent adverse effects; most sampled prairie dogs (90%) and associated small rodents (78%) had consumed baits. Visual counts of prairie dogs and their burrows revealed no evidence of prairie dog decline after vaccine exposure. No vaccine-related morbidity, mortality, or gross or microscopic lesions were observed. Poxviruses were not isolated from any animal sampled prior to bait distribution or on sites that received placebo baits. We isolated RCN-F1/V307 from 17 prairie dogs and two deer mice (Peromyscus maniculatus) captured on sites where vaccine-laden baits were distributed. Based on these findings, studies examining the utility and effectiveness of oral vaccination to prevent plague-induced mortality in prairie dogs and associated species are underway.

  1. Apparent field safety of a raccoon poxvirus-vectored plague vaccine in free-ranging prairie dogs (Cynomys spp.), Colorado, USA (United States)

    Tripp, Daniel W.; Rocke, Tonie E.; Streich, Sean P.; Abbott, Rachel C.; Osorio, Jorge E.; Miller, Michael W.


    Prairie dogs (Cynomys spp.) suffer high rates of mortality from plague. An oral sylvatic plague vaccine using the raccoon poxvirus vector (designated RCN-F1/V307) has been developed for prairie dogs. This vaccine is incorporated into palatable bait along with rhodamine B as a biomarker. We conducted trials in August and September 2012 to demonstrate uptake and apparent safety of the RCN-F1/V307 vaccine in two prairie dog species under field conditions. Free-ranging prairie dogs and other associated small rodents readily consumed vaccine-laden baits during field trials with no apparent adverse effects; most sampled prairie dogs (90%) and associated small rodents (78%) had consumed baits. Visual counts of prairie dogs and their burrows revealed no evidence of prairie dog decline after vaccine exposure. No vaccine-related morbidity, mortality, or gross or microscopic lesions were observed. Poxviruses were not isolated from any animal sampled prior to bait distribution or on sites that received placebo baits. We isolated RCN-F1/V307 from 17 prairie dogs and two deer mice (Peromyscus maniculatus) captured on sites where vaccine-laden baits were distributed. Based on these findings, studies examining the utility and effectiveness of oral vaccination to prevent plague-induced mortality in prairie dogs and associated species are underway.

  2. Radioactive mineral occurences of Colorado and bibliography. [2500 citations in bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Nelson-Moore, J.L.; Collins, D.B.; Hornbaker, A.L.


    This two-part report provides an essentially complete listing of radioactive occurrences in Colorado, with a comprehensive bibliography and bibliographic cross-indexes. Part 1 lists approximately 3000 known radioactive occurrences with their locations and brief accounts of the geology, mineralogy, radioactivity, host rock, production data, and source of data for each. The occurrences are classified by host rock and plotted on U.S. Geological Survey 1/sup 0/ x 2/sup 0/ topographic quadrangle maps with a special 1 : 100,000-scale base map for the Uravan mineral belt. Part 2 contains the bibliography of approximately 2500 citations on radioactive mineral occurrences in the state, with cross-indexes by county, host rock, and the special categories of ''Front Range,'' ''Colorado Plateau,'' and ''thorium.'' The term ''occurrence'' as used in this report is defined as any site where the concentration of uranium or thorium is at least 0.01% or where the range of radioactivity is greater than twice the background radioactivity. All citations and occurrence data are stored on computer diskettes for easy retrieval, correction, and updating.

  3. Radiative plateau inflation

    CERN Document Server

    Ballesteros, Guillermo


    We describe how monomial chaotic inflation becomes compatible with the latest CMB data thanks to radiative corrections producing a plateau. The interactions of the inflation with other fields, required for reheating, can flatten the potential and moderate the production of primordial gravitational waves, keeping these below the current upper bound. We show that the appearance of a plateau requires that the inflaton couples to fermions and to another scalar or a gauge group. We give concrete examples of minimal particle physics models leading to plateaus for quadratic and quartic chaotic inflation. We also provide a three-parameter model-independent description of radiatively corrected inflation that is amenable to CMB analyses.

  4. Plateau's Problem: What's Next


    Harrison, Jenny; Pugh, Harrison


    Plateau's problem is not a single conjecture or theorem, but rather an abstract framework, encompassing a number of different problems in several related areas of mathematics. In its most general form, Plateau's problem is to find an element of a given collection \\(\\cal{C} \\) of "surfaces" specified by some boundary constraint, which minimizes, or is a critical point of, a given "area" function \\(F:\\cal{C}\\to \\R \\). In addition, one should also show that any such element satisfies some sort o...

  5. Plateau Indian Ways with Words (United States)

    Monroe, Barbara


    The indigenous rhetoric of the Plateau Indians continues to exert a discursive influence on student writing in reservation schools today. Plateau students score low on state-mandated tests and on college writing assignments, in large part because the pervasive personalization of Plateau rhetoric runs counter to the depersonalization of academic…

  6. Birds and mammals of Manitou Experimental Forest, Colorado (United States)

    Meredith J. Morris; Vincent H. Reld; Richard E. Pillmore; Mary C. Hammer


    Seasonal occurrence, relative abundance, and habitat preference are listed for 90 bird and 41 mammal species that can be found at Manitou Experimental Forest. An annotated list is given also for an additional 70 casual or accidental bird species. Manitou Experimental Forest is located near Colorado Springs in the montane zone of the Colorado Front Range.

  7. How Evapotranspiration And Deep Percolation Impact The Precipitation-Runoff Response, Aquifer Recharge, And Linked Nutrient-Water Cycling At The Subalpine Como Creek Drainage In The Colorado Front Range (United States)

    Zeliff, M. M.; Williams, M. W.; Cowie, R. M.; Burns, S.


    Here we evaluate how evapotranspiration (ET) and deep percolation (DP) impact the precipitation-runoff response, aquifer recharge, and linked nutrient-water cycling at the 664-ha sub-alpine Como Creek drainage in the Colorado Front Range. ET is measured continuously using eddy covariance, soil moisture (SM) is measured using 2-m vertical sensor arrays, groundwater (GW) by a series of piezometers, and precipitation (P) is measured daily along with snow-water equivalent (SWE). From 2004 to 2009, annual P averaged 813 mm and ET averaged 590 mm, with ET thus representing 72.5% of annual P. Using multiple linear regression analysis, discharge (Q) was found to be modeled reasonably well with the independent variables of ET (p ground water system and subsequent precipitation does little to contribute to streamflow for the current year, but serves to offset ET, which may explain the decrease in Q with increasing P. Newly installed piezometers (12, at depths ranging from 5 to 30 m) provide evidence that this portion of the basin is largely a loosing reach during snowmelt, with GW in the piezometers increasing 5-7 m. After peak snowmelt however, the reach starts gaining again with piezometer levels dropping. Time series plots reveal a strong relationship between SWE and Q with larger SWE often resulting in larger Q. Thus, surface-groundwater interactions are tightly coupled during snowmelt, with snowmelt first replenishing the subsurface water deficit before contributing to discharge. The deepest two piezometers (18 and 29 m) were not showing any significant water level declines by early August 2011, suggesting that water loss to DP is a potential important component of the water balance in the Como Creek catchment. Wet precipitation chemistry from the National Atmospheric Deposition Program monitors in the basin show that atmospheric deposition of inorganic nitrogen has increased several-fold in the last 25 years. However, in contrast to higher-elevation catchments, which

  8. 78 FR 50095 - Notice of Inventory Completion: History Colorado, Formerly Colorado Historical Society, Denver, CO (United States)


    ... Mountain Reservation, Colorado, New Mexico & Utah may proceed. History Colorado is responsible for... National Park Service Notice of Inventory Completion: History Colorado, Formerly Colorado Historical Society, Denver, CO AGENCY: National Park Service, Interior. ACTION: Notice. ] SUMMARY: History Colorado...

  9. BLM Colorado Grazing Pastures (United States)

    Department of the Interior — Shapefile Format –This polygon feature class represents the spatial extent and boundaries for BLM Colorado Grazing Pastures. A grazing pasture is simply a subset of...

  10. BLM Colorado Grazing Pastures (United States)

    Department of the Interior — KMZ File Format –This polygon feature class represents the spatial extent and boundaries for BLM Colorado Grazing Pastures. A grazing pasture is simply a subset of a...

  11. The instrumental climate history of southwestern Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Doesken, N.J.; McKee, T.B. [Colorado State Univ., Fort Collins, CO (United States)


    Instrumental observations of the climate of southwestern Colorado date back to about 1880. Climatic conditions since the late 19th century will be described with emphasis on temperatures, temperature ranges and observed precipitation. Typical seasonal patterns of temperature and precipitation will be shown, and variations and apparent trends over time will be discussed. Drought characteristics will be described based on a standardized precipitation index developed for Colorado. Finally, brief comments on the challenge of collecting accurate and consistent long-term data will be given.

  12. Colorado statewide historic bridge inventory. (United States)


    The purpose of the Colorado statewide historic bridge inventory was to document and evaluate the National : Register of Historic Places eligibility all on-system highway bridges and grade separation structures built in : Colorado between 1959 and 196...

  13. Introduction: CRevolution 2: origin and evolution of the Colorado River System II (United States)

    Karlstrom, Karl E.; Beard, L. Sue; House, P. Kyle; Young, Richard A.; Aslan, Andres; Billingsley, George; Pederson, Joel


    A 2010 Colorado River symposium held in Flagstaff, Arizona, in May 2010, had 70 participants who engaged in intense debate about the origin and evolution of the Colorado River system. This symposium, built on two previous decadal scientific meetings, focused on forging scientific consensus where possible, while also articulating continued controversies regarding the Cenozoic evolution of the Colorado River System and the landscapes of the Colorado Plateau–Rocky Mountain region that it drains. New developments involved hypotheses that Neogene mantle flow is driving plateau tilting and differential uplift, with consensus that multidisciplinary studies involving differential incision studies and additional geochronology and thermochronology are needed to test the relative importance of tectonic and geomorphic forcings in shaping the spectacular landscapes of the Colorado Plateau region. In addition to the scientific goals, the meeting participants emphasized the iconic status of Grand Canyon for geosciences, and the importance of good communication between the research community, the geoscience education/interpretation community, the public, and the media. Building on a century-long tradition, this region still provides a globally important natural laboratory for studies of the interactions of erosion and tectonism in the shaping landscape of elevated plateaus.

  14. Asbestos in Colorado Schools. (United States)

    Baldwin, Cynthia A.

    This study determined, by means of a random sample, how many of Colorado's public schools have asbestos materials and estimated the potential risk of exposure presented by these materials. Forty-one schools were surveyed. Bulk samples of possible asbestos materials were collected and analyzed using the K-squared Asbestos Screening Test to…

  15. Understanding uncertainties in future Colorado River streamflow (United States)

    Julie A. Vano,; Bradley Udall,; Cayan, Daniel; Jonathan T Overpeck,; Brekke, Levi D.; Das, Tapash; Hartmann, Holly C.; Hidalgo, Hugo G.; Hoerling, Martin P; McCabe, Gregory J.; Morino, Kiyomi; Webb, Robert S.; Werner, Kevin; Lettenmaier, Dennis P.


    The Colorado River is the primary water source for more than 30 million people in the United States and Mexico. Recent studies that project streamf low changes in the Colorado River all project annual declines, but the magnitude of the projected decreases range from less than 10% to 45% by the mid-twenty-first century. To understand these differences, we address the questions the management community has raised: Why is there such a wide range of projections of impacts of future climate change on Colorado River streamflow, and how should this uncertainty be interpreted? We identify four major sources of disparities among studies that arise from both methodological and model differences. In order of importance, these are differences in 1) the global climate models (GCMs) and emission scenarios used; 2) the ability of land surface and atmospheric models to simulate properly the high-elevation runoff source areas; 3) the sensitivities of land surface hydrology models to precipitation and temperature changes; and 4) the methods used to statistically downscale GCM scenarios. In accounting for these differences, there is substantial evidence across studies that future Colorado River streamflow will be reduced under the current trajectories of anthropogenic greenhouse gas emissions because of a combination of strong temperature-induced runoff curtailment and reduced annual precipitation. Reconstructions of preinstrumental streamflows provide additional insights; the greatest risk to Colorado River streamf lows is a multidecadal drought, like that observed in paleoreconstructions, exacerbated by a steady reduction in flows due to climate change. This could result in decades of sustained streamflows much lower than have been observed in the ~100 years of instrumental record.


    Energy Technology Data Exchange (ETDEWEB)




  17. Operative results of closed tibial plateau fractures

    Directory of Open Access Journals (Sweden)

    Mathur Hitin


    Full Text Available Background: Management of tibial plateau fractures remains challenging because of their number, variety and associated soft tissue injuries that further augment their complexity. Comparison of operative results in recent reports has been difficult due to a lack of standard fracture classification scheme and uniform standardized objective criteria for evaluating results. Methods: Between August 1998 to December 2002, 27 closed tibial plateau fractures were treated operatively using methods and principles advocated by AO/ASIF and followed up for an average of 35.74 months (range 24-68 months. Fractures were classified according to Schatzker′s staging system and results evaluated using Rasmussen′s 30-point clinical grading system and Rasmussen′s radiological evaluation of the knee at a minimum follow up of 2 years. Results: Type II was the most common fracture type (9 cases followed by type I (6 cases. There were 37% excellent and 51.85% good functional results with only 3 patients having unacceptable results. The mean Rasmussen′s functional score was 25.062 (range 15-30. Minimal fixation in comminuted or depressed fractures as compared to rigid fixation was the cause of unacceptable results. Loss of knee range of motion in a few cases was attributed to delayed knee mobilization in these cases. Using Rasmussen′s radiological grading, 2 patients had excellent results and 81.48 % patients had good results. Only 3 patients had poor radiological results. The mean Rasmussen′s radiological score was 15.33 (range 10-18. Moreover, clinical evaluation did not correlate with the follow up radiograph. Conclusion: Anatomic reduction and rigid internal fixation followed by early knee motion and partial weight bearing during bone healing are the cornerstones in the treatment of tibial plateau fractures. Standard fracture classification, uniform reporting and evaluating criteria, along with detailed analysis of uniform treatment methods, has helped us

  18. Colorado's hydrothermal resource base: an assessment

    Energy Technology Data Exchange (ETDEWEB)

    Pearl, R.H.


    As part of its effort to more accurately describe the nations geothrmal resource potential, the US Department of Energy/Division of Geothermal Energy contracted with the Colorado Geological survey to appraise the hydrothermal (hot water) geothermal resources of Colorado. Part of this effort required that the amount of energy that could possibly be contained in the various hydrothermal systems in Colorado be estimated. The findings of that assessment are presented. To make these estimates the geothermometer reservoir temperatures estimated by Barrett and Pearl (1978) were used. In addition, the possible reservoir size and extent were estimated and used. This assessment shows that the total energy content of the thermal systems in Colorado could range from 4.872 x 10{sup 15} BTU's to 13.2386 x 10{sup 15} BTU's.

  19. Colorado Geothermal Commercialization Program

    Energy Technology Data Exchange (ETDEWEB)

    Healy, F.C.


    Chaffee County, located in central Colorado, has immense potential for geothermal development. This report has been prepared to assist residents and developers in and outside the area to develop the hydrothermal resources of the county. Data has been collected and interpreted from numerous sources in order to introduce a general description of the area, estimate energy requirements, describe the resources and postulate a development plan. Electric power generation and direct heat application potential for the region are described.

  20. Determining geometric links between glaciers and lakes on the Tibetan plateau

    NARCIS (Netherlands)

    Phan Hien, V.; Lindenbergh, R.C.; Menenti, M.


    The Tibetan plateau and surrounding mountain ranges contain the largest amount of ice outside the polar region. The Tibetan plateau also contains more than one thousand lakes and is the origin of a large part of the water resources of South and East Asia, the most densely populated regions on earth.

  1. Hydrogeology of the Coconino Plateau and adjacent areas, Coconino and Yavapai Counties, Arizona (United States)

    Bills, Donald J.; Flynn, Marilyn E.; Monroe, Stephen A.


    Two large, regional ground-water flow systems occur in the Coconino Plateau and adjacent areas: the C aquifer and the Redwall-Muav aquifer. The C aquifer occurs mainly in the eastern and southern parts of the 10,300-square-mile Coconino Plateau study area, and the Redwall-Muav aquifer underlies the entire study area. The C aquifer is a water-table aquifer for most of its occurrence with depths to water that range from a few hundred feet to more than 1,500 feet. In the western part of the Coconino Plateau study area, the C aquifer is dry except for small localized perched water-bearing zones decoupled from the C aquifer to the east. The Redwall-Muav aquifer underlies the C aquifer and ranges from at least 3,000 feet below land surface in the western part of the Coconino Plateau study area to more than 3,200 feet below land surface in the eastern part of the study area. The Redwall-Muav aquifer is a confined aquifer for most of its occurrence with hydraulic heads of several hundred to more than 500 feet above the top of the aquifer in the western part of the study area and more than 2,000 feet above the top of the aquifer in the eastern part of the study area near Flagstaff. In the eastern and northeast parts of the area, the C aquifer and the Redwall-Muav aquifer are in partial hydraulic connection through faults and other fractures. The water discharging from the two aquifers on the Coconino Plateau study area is generally of good quality for most intended uses. Water from sites in the lower Little Colorado River Canyon had high concentrations of most trace elements relative to other springs, rivers, and streams in the study area. Concentrations of barium, arsenic, uranium, and lead, and gross alpha radioactivity were greater than U.S. Environmental Protection Agency Maximum Contaminant Levels for drinking water at some sites. Ground water discharging to most springs, streams, and wells on the Coconino Plateau and in adjacent areas is a calcium magnesium

  2. Medial tibial plateau morphology and stress fracture location: A magnetic resonance imaging study. (United States)

    Yukata, Kiminori; Yamanaka, Issei; Ueda, Yuzuru; Nakai, Sho; Ogasa, Hiroyoshi; Oishi, Yosuke; Hamawaki, Jun-Ichi


    To determine the location of medial tibial plateau stress fractures and its relationship with tibial plateau morphology using magnetic resonance imaging (MRI). A retrospective review of patients with a diagnosis of stress fracture of the medial tibial plateau was performed for a 5-year period. Fourteen patients [three female and 11 male, with an average age of 36.4 years (range, 15-50 years)], who underwent knee MRI, were included. The appearance of the tibial plateau stress fracture and the geometry of the tibial plateau were reviewed and measured on MRI. Thirteen of 14 stress fractures were linear, and one of them stellated on MRI images. The location of fractures was classified into three types. Three fractures were located anteromedially (AM type), six posteromedially (PM type), and five posteriorly (P type) at the medial tibial plateau. In addition, tibial posterior slope at the medial tibial plateau tended to be larger when the fracture was located more posteriorly on MRI. We found that MRI showed three different localizations of medial tibial plateau stress fractures, which were associated with tibial posterior slope at the medial tibial plateau.

  3. Nitrogen loss from windblown agricultural soils in the Columbia Plateau (United States)

    Wind erosion of agricultural soils can degrade both air quality and soil productivity in the Columbia Plateau of the Pacific Northwest United States. Soils in the region contain fine particles that, when suspended, are highly susceptible to long range transport in the atmosphere. Nitrogen (N) associ...

  4. Moho offset across the northern margin of the tibetan plateau (United States)

    Zhu; Helmberger


    Anomalous double-pulse teleseismic P-wave arrivals were observed at one station near the northern margin of the Tibetan Plateau. The azimuthal dependence of the waveform distortion and its absence at nearby stations indicated that the distortion was produced by receiver-side crustal heterogeneity. Modeling of the three-component data revealed a 15- to 20-kilometer Moho offset that occurs over a narrow lateral range of less than 5 kilometers. This east-west-striking offset separates the thick Tibetan Plateau crust from the Qaidam Basin crust. Such a sharp crustal thickness change implies a weak Tibetan Plateau crust that thickens vertically in response to penetration by India from the south and to blockage caused by a strong Qaidam Basin crust to the north.

  5. Therapeutical Management of the Tibial Plateau Fractures

    Directory of Open Access Journals (Sweden)

    Obada B.


    Full Text Available The study was aimed to identify the role of surgical treatment of tibial plateau fractures, its functional outcome and complications. Demographic data for the patients and details of current clinical and radiological follow-up findings were obtained to assess range of motion, clinical stability, alignment of the knee, and posttraumatic arthrosis (Kellgren/Lawrence score. 64 cases of tibial plateau fractures treated by different surgical methods and variuos implants type were studied from 2013 to 2015 and followed-up for minimum period of 6 months. The systematisation of the casuitry was made using Schatzker and AO classifications. The treatment methods consist of: percutaneous cannulated cancellous screws, ORIF with buttress plate with or without bone grafting, locking or nonlocking plates, external fixator. As complications we found: redepression 4 case, malunion 2 cases, knee stiffness 9, wound dehiscence in 1 cases and non-union or infection in none of our cases. The average flexion of the injured knee was significantly lower in comparison with the contralateral side (124.9°/135.2°. Knee stability did not differ statistically significantly. There were no signs of posttraumatic arthrosis in 45% of cases, mild signs in 30%, clear signs in 18%, and severe signs in 7%. As conclusion we found that surgical management of tibial plateau fractures will give excellent anatomical reduction and rigid fixation to restore articular congruity, facilitate early motion and reduce arthrosis risk and hence to achieve optimal knee function. The choice of optimal surgical methods, proper approach and implant is made in relation to fracture type according Schatzker and AO classification.

  6. Lateral tibial plateau autograft in revision surgery for failed medial unicompartmental knee arthroplasty. (United States)

    Cerciello, Simone; Morris, Brent Joseph; Lustig, Sebastien; Visonà, Enrico; Cerciello, Giuliano; Corona, Katia; Neyret, Philippe


    Revision surgery for failed unicompartmental knee arthroplasty (UKA) with bone loss is challenging. Several options are available including cement augmentation, metal augmentation, and bone grafting. The aim of the present study was to describe a surgical technique for lateral tibial plateau autografting and report mid-term outcomes. Eleven consecutive patients (median age 69.5 years) affected by posteromedial tibial plateau collapse after medial UKA were enrolled in the present study. The delay between UKA and revision surgery was 21 months (range 15-36 months). All patients were revised with a cemented posterior-stabilized implant, with a tibial stem. Medial tibial plateau bone loss was treated with an autologous lateral tibial plateau bone graft secured with two absorbable screws. All patients were evaluated with the Oxford Knee Score (OKS), visual analogue scale for pain (VAS), and complete radiographic evaluation. At a median follow-up of 60 months (range 36-84 months), the OKS improved from 21.5 (range 16-26) to 34.5 (range 30-40) (p plateau bone autograft is an alternative to metal wedge or cement augments in the treatment of medial plateau collapse after UKA. Primary fixation of the tibial plateau autograft can be achieved with absorbable screws and a tibial-stemmed implant. Further comparative studies with a larger series may be helpful to draw definitive conclusions. Case series, Level IV.

  7. Colorado State Capitol Geothermal project

    Energy Technology Data Exchange (ETDEWEB)

    Shepherd, Lance [Colorado Department of Personnel and Adminstration, Denver, CO (United States)


    Colorado State Capitol Geothermal Project - Final report is redacted due to space constraints. This project was an innovative large-scale ground-source heat pump (GSHP) project at the Colorado State Capitol in Denver, Colorado. The project employed two large wells on the property. One for pulling water from the aquifer, and another for returning the water to the aquifer, after performing the heat exchange. The two wells can work in either direction. Heat extracted/added to the water via a heat exchanger is used to perform space conditioning in the building.

  8. Colorado wetlands initiative : 1997-2000 : Protecting Colorado's wetlands resource (United States)

    US Fish and Wildlife Service, Department of the Interior — The Colorado Wetlands Initiative is an endeavor to protect wetlands and wetland-dependent wildlife through the use of voluntary, incentive-based mechanisms. It is a...

  9. Smoke from Colorado Wildfires (United States)


    The Hayman fire, situated about 65 kilometers southwest of Denver, Colorado, is the largest fire ever recorded in that state. The amount and distribution of smoke from the Hayman fire and from the Ponil Complex fires south of the New Mexico-Colorado border are portrayed in these views from the Multi-angle Imaging SpectroRadiometer (MISR). The images were captured on June 9, 2002, on the second day of the Hayman fire, when only about 13 percent of the total 137,000 acres eventually consumed had been scorched.The image at top-left was acquired by MISR's most oblique (70-degree) forward-viewing camera, and the view at bottom-left was captured by MISR's 26-degree forward-viewing camera. Both left-hand panels are 'false color' views, utilizing near-infrared, red, and blue spectral bands displayed as red, green and blue respectively. With this spectral combination, highly vegetated areas appear red. At top right is a map of aerosol optical depth. This map utilizes the capability of the oblique view angles to measure the abundance of particles in the atmosphere. Haze distributed across the eastern part of the state is indicated by a large number of green pixels, and areas where no retrieval occurred are shown in dark grey. The more oblique perspective utilized within the top panels enhances the appearance of smoke and reveals the haze. In the lower left-hand panel the view is closer to nadir (downward-looking). Here the smoke plumes appear more compact and the haze across eastern Colorado is not detected. The lower right-hand panel is a stereoscopically derived height field that echoes the compact shape of the smoke plumes in the near-nadir image. Results indicate that the smoke plumes reached altitudes of a few kilometers above the surface terrain, or about the same height as the small clouds that appear orange along the bottom edge to the left of center.Data used in these visualizations were generated as part of operational processing at the Atmospheric Sciences Data

  10. Water chemistry of Rocky Mountain Front Range aquatic ecosystems (United States)

    Robert C. Musselman; Laura Hudnell; Mark W. Williams; Richard A. Sommerfeld


    A study of the water chemistry of Colorado Rocky Mountain Front Range alpine/subalpine lakes and streams in wilderness ecosystems was conducted during the summer of 1995 by the USDA Forest Service Arapaho and Roosevelt National Forests and Rocky Mountain Forest and Range Experiment Station, and the University of Colorado Institute of Alpine and Arctic Research. Data...

  11. BLM Colorado Oil Shale Leases (United States)

    Department of the Interior — KMZ File Format –This data set contains the Oil Shale Leases for the State of Colorado, derived from Legal Land Descriptions (LLD) contained in the US Bureau of Land...

  12. Colorados asutati rohelise ehituse toetusprogramm

    Index Scriptorium Estoniae


    USA Colorado osariigi rohelised arhitektid ja projekteerijad asutasid koos ehitusfirmadega programmi "Ehita rohelist Coloradot", mille raames pakutakse rohelise maja või korteri ehitamise väljaõpet

  13. BLM Colorado Surface Management Agency (United States)

    Department of the Interior — Shapefile Format – Illustratation of the surface management agency for lands within the state of Colorado. Formerly called land status. This data set is a result of...

  14. The Pajarito Plateau: A bibliography (United States)

    Mathien, Frances Joan; Steen, Charlie R.; Allen, Craig D.


    This bibliography is the result of two initially independent projects. As the consulting archaeologist at Los Alamos National Laboratory (LANL), Charlie R. Steen collected entries at the suggestion of the staff of the Environmental Surveillance Group of the Health, Safety, and Environmental Division, HSE-8. The primary purpose was to aid the staff in evaluating cultural resources on LANL lands. In addition to works that related to the archaeology and history of the area, Steen included notations of a few books and articles in other fields such as geology and natural history. It was hoped that they also would be of value to other organizations and to students of past human activities on the Pajarito Plateau.At the same time, the National Park Service (NPS) was planning a major survey of Bandelier National Monument (BNM). As part of this plan, the author was asked to prepare a background document that described research previously carried out in the area, including an annotated bibliography. Although the survey would be limited to the park boundaries, the larger Pajarito Plateau is a more logical study area from physiographic, environmental, and cultural perspectives; hence the focus was on this larger region. Mathien (1986) also included some references to natural resources studies, particularly those initiated by NPS within Bandelier National Monument.Both bibliographies were made available to Colleen Olinger and Beverly Larson of the Health and Environmental Services Group at Los Alamos. They realized that while neither was complete, each included entries missing from the other. Larson suggested the two bibliographies be combined. (At this time, Craig Allen was studying the landscape of the Jemez Mountains [Allen 1984c, 1989]. His investigations included much detailed information on natural resource studies and were added in 1991 and 1992.)To limit the scope of their work, Steen and Mathien had chosen their parameter: the Pajarito Plateau. Geographically, the

  15. The Pajarito Plateau: a bibliography (United States)

    Mathien, Frances Joan; Steen, Charlie R.; Allen, Craig D.


    This bibliography is the result of two initially independent projects. As the consulting archaeologist at Los Alamos National Laboratory (LANL), Charlie R. Steen collected entries at the suggestion of the staff of the Environmental Surveillance Group of the Health, Safety, and Environmental Division, HSE-8. The primary purpose was to aid the staff in evaluating cultural resources on LANL lands. In addition to works that related to the archaeology and history of the area, Steen included notations of a few books and articles in other fields such as geology and natural history. It was hoped that they also would be of value to other organizations and to students of past human activities on the Pajarito Plateau.At the same time, the National Park Service (NPS) was planning a major survey of Bandelier National Monument (BNM). As part of this plan, the author was asked to prepare a background document that described research previously carried out in the area, including an annotated bibliography. Although the survey would be limited to the park boundaries, the larger Pajarito Plateau is a more logical study area from physiographic, environmental, and cultural perspectives; hence the focus was on this larger region. Mathien (1986) also included some references to natural resources studies, particularly those initiated by NPS within Bandelier National Monument.Both bibliographies were made available to Colleen Olinger and Beverly Larson of the Health and Environmental Services Group at Los Alamos. They realized that while neither was complete, each included entries missing from the other. Larson suggested the two bibliographies be combined. (At this time, Craig Allen was studying the landscape of the Jemez Mountains [Allen 1984c, 1989]. His investigations included much detailed information on natural resource studies and were added in 1991 and 1992.)To limit the scope of their work, Steen and Mathien had chosen their parameter: the Pajarito Plateau. Geographically, the

  16. Systeemomschrijving “Plateau 2.0”


    Hoofs, Anita


    En varkenshok met plateau is een hok waarin varkens vrij beschikken over twee verblijfsniveaus, één op de begane grond en één op het plateau. Varkens kunnen gemakkelijk het plateau op - en aflopen via een trap. Bij toepassing van een plateau, dat voldoet aan de systeemomschrijving, mag het beschikbare vloeroppervlak van het plateau als beschikbaar vloeroppervlak meegerekend worden.

  17. 78 FR 19296 - Notice of Inventory Completion: History Colorado, formerly Colorado Historical Society, Denver, CO (United States)


    ... Reservation, Colorado, New Mexico & Utah agreed to accept disposition of the human remains. In 2006, History... National Park Service Notice of Inventory Completion: History Colorado, formerly Colorado Historical Society, Denver, CO AGENCY: National Park Service, Interior. ACTION: Notice. SUMMARY: History Colorado...

  18. Giant plateau in the THz Faraday angle in gated Bi2Se3


    Jenkins, Gregory S.; Sushkov, Andrei B.; Schmadel, Don C.; Kim, M. -H.; Brahlek, Matthew; Bansal, Namrata; Oh, Seongshik; Drew, H. Dennis


    We report gated terahertz Faraday angle measurements on epitaxial Bi2Se3 thin films capped with In2Se3. A plateau is observed in the real part of the Faraday angle at an onset gate voltage corresponding to no band bending at the surface which persists into accumulation. The plateau is two orders of magnitude flatter than the step size expected from a single Landau Level in the low frequency limit, quantized in units of the fine structure constant. At 8 T, the plateau extends over a range of g...

  19. The Colorado Adoption Project. (United States)

    Rhea, Sally-Ann; Bricker, Josh B; Wadsworth, Sally J; Corley, Robin P


    This paper describes the Colorado Adoption Project (CAP), an ongoing genetically informative longitudinal study of behavioral development. We describe the features of the adoption design used in CAP, and discuss how this type of design uses data from both parent-offspring and related- versus unrelated-sibling comparisons to estimate the importance of genetic and shared environmental influences for resemblance among family members. The paper provides an overview of CAP's history, how subjects were ascertained, recruited, and retained, and the domains of assessment that have been explored since the CAP's initiation in 1975. Findings from some representative papers that make use of data from CAP participants illustrate the study's multifaceted nature as a parent-offspring and sibling behavioral genetic study, a study that parallels a complimentary twin study, a longitudinal study of development, a source of subjects for molecular genetic investigation, and a study of the outcomes of the adoption process itself. As subjects assessed first at age 1 approach age 40, we hope the CAP will establish itself as the first prospective adoption study of lifespan development.

  20. Anatomy of a Mountain Range. (United States)

    Chew, Berkeley


    Provides written tour of Colorado Rockies along San Juan Skyway in which the geological features and formation of the mountain range is explored. Discusses evidence of geologic forces and products such as plate tectonic movement and the Ancestral Rockies; subduction and the Laramide Orogeny; volcanism and calderas; erosion, faulting, land…


    Johnson, Bruce R.; Ellis, Clarence E.


    Mineral surveys were undertaken of a wilderness study area which includes most of the Sangre de Cristo Range of south-central Colorado. Four areas of probable mineral-resource potential for gold, silver, and base metals lie along a northwest structural trend which follows the western margin of the range north of the Great Sand Dunes National Monument and crosses the range south of the monument. An area of probable mineral-resource potential for similar minerals plus tungsten has been identified east of Blanca Peak at the extreme southern end of the study area. Another area of probable mineral-resource potential includes molybdenum mineralization associated with the Rito Alto stock. A small area of probable geothermal resource potential exists on the west side of the area around the Valley View Hot Springs. There is little promise for the occurrence of oil and gas resources.

  2. Landsat Thematic Mapper Image Mosaic of Colorado (United States)

    Cole, Christopher J.; Noble, Suzanne M.; Blauer, Steven L.; Friesen, Beverly A.; Bauer, Mark A.


    The U.S. Geological Survey (USGS) Rocky Mountain Geographic Science Center (RMGSC) produced a seamless, cloud-minimized remotely-sensed image spanning the State of Colorado. Multiple orthorectified Landsat 5 Thematic Mapper (TM) scenes collected during 2006-2008 were spectrally normalized via reflectance transformation and linear regression based upon pseudo-invariant features (PIFS) following the removal of clouds. Individual Landsat scenes were then mosaicked to form a six-band image composite spanning the visible to shortwave infrared spectrum. This image mosaic, presented here, will also be used to create a conifer health classification for Colorado in Scientific Investigations Map 3103. An archive of past and current Landsat imagery exists and is available to the scientific community (, but significant pre-processing was required to produce a statewide mosaic from this information. Much of the data contained perennial cloud cover that complicated analysis and classification efforts. Existing Landsat mosaic products, typically three band image composites, did not include the full suite of multispectral information necessary to produce this assessment, and were derived using data collected in 2001 or earlier. A six-band image mosaic covering Colorado was produced. This mosaic includes blue (band 1), green (band 2), red (band 3), near infrared (band 4), and shortwave infrared information (bands 5 and 7). The image composite shown here displays three of the Landsat bands (7, 4, and 2), which are sensitive to the shortwave infrared, near infrared, and green ranges of the electromagnetic spectrum. Vegetation appears green in this image, while water looks black, and unforested areas appear pink. The lines that may be visible in the on-screen version of the PDF are an artifact of the export methods used to create this file. The file should be viewed at 150 percent zoom or greater for optimum viewing.

  3. FY 1978-79 Zero-Base Budget Review. The Colorado State System of Community and Junior Colleges: A Summary. (United States)

    Tollefson, Terrence A.

    Two reports are presented in this document prepared for the Colorado State Legislature. The first, a zero-base budget review, presents a summary of the characteristics of the student population served by Colorado's 11 junior colleges. The summary includes statistics on age range, state of residence, gender, ethnic background, types of financial…

  4. Into Tibet: An Early Pliocene Dispersal of Fossil Zokor (Rodentia: Spalacidae) from Mongolian Plateau to the Hinterland of Tibetan Plateau. (United States)

    Li, Qiang; Wang, Xiaoming


    This paper reports the fossil zokors (Myospalacinae) collected from the lower Pliocene (~4.4 Ma) of Zanda Basin, southwestern Tibet, which is the first record in the hinterland of Tibetan Plateau within the Himalayan Range. Materials include 29 isolated molars belonging to Prosiphneus eriksoni (Schlosser, 1924) by having characters including large size, highly fused roots, upper molars of orthomegodont type, m1 anterior cap small and centrally located, and first pair of m1 reentrants on opposing sides, high crowns, and high value of dentine tract parameters. Based on the cladistics analysis, all seven species of Prosiphneus and P. eriksoni of Zanda form a monophyletic clade. P. eriksoni from Zanda, on the other hand, is nearly the terminal taxon of this clade. The appearance of P. eriksoni in Zanda represents a significant dispersal in the early Pliocene from its center of origin in north China and Mongolian Plateau, possibly via the Hol Xil-Qiangtang hinterland in northern Tibet. The fast evolving zokors are highly adapted to open terrains at a time when regional climates had become increasingly drier in the desert zones north of Tibetan Plateau during the late Miocene to Pliocene. The occurrence of this zokor in Tibet thus suggests a rather open steppe environment. Based on fossils of large mammals, we have formulated an "out of Tibet" hypothesis that suggests earlier and more primitive large mammals from the Pliocene of Tibet giving rise to the Ice Age megafauna. However, fossil records for large mammals are still too poor to evaluate whether they have evolved from lineages endemic to the Tibetan Plateau or were immigrants from outside. The superior record of small mammals is in a better position to address this question. With relatively dense age intervals and numerous localities in much of northern Asia, fossil zokors provide the first example of an "into Tibet" scenario--earlier and more primitive taxa originated from outside of the Tibetan Plateau and the

  5. Diagnosis and Treatment of Anterior Tibial Plateau Fracture-Dislocation: A Case Series and Literature Review. (United States)

    Wu, Kai; Huang, Jianhua; Lin, Jian; Wang, Qiugen


    Anterior tibial plateau fracture is fairly common. This study was aimed at introducing a type of severe anterior tibial plateau fracture (anterior tibial plateau fracture-dislocation) and evaluating its clinical characteristics and treatment strategies. In this study, 18 patients with severe anterior tibial plateau fracture (study group) were enrolled between November 2006 and August 2014, and their data were compared with those of 21 patients treated for normal Schatzker type VI tibial plateau fracture (control group) between January 2010 and August 2014. At the last follow-up, bony union had been achieved in both groups. The incidence of ligament injury was higher in the case of anterior tibial plateau fracture than control group. The average range of motion in the study group was 0.56 to 109 degrees, while that in the control group was 1.81 to 117 degrees. The average Hospital for Special Surgery scores and Lysholm scores in the study group were significantly lower than those in the control group. Further, the incidence of postoperative complications and reduction loss were higher for anterior tibial plateau fracture cases than for normal Schatzker type VI fracture. Our findings also showed a significantly higher rate (22.2%) of popliteal artery injury in the study group than in the control group. Anterior tibial plateau fracture-dislocation is a special type of Schatzker type VI fracture with very low incidence and most commonly characterized by the anterior subsidence of the tibial component, irreducible dislocation of the knee joint, and varying degrees of neurovascular and knee-joint peripheral ligaments injuries, as well as high incidence of complications during fixation surgery. The treatment of anterior tibial plateau fracture-dislocation is challenging even for experienced surgeons. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  6. Tibial Plateau Fracture Characteristics: Computed Tomography Mapping of Lateral, Medial, and Bicondylar Fractures. (United States)

    Molenaars, Rik J; Mellema, Jos J; Doornberg, Job N; Kloen, Peter


    Computed tomography (CT) is seen as a useful diagnostic modality in preoperative planning for tibial plateau fractures. The purpose of this study was to characterize patterns of tibial plateau fractures with use of CT mapping. We hypothesized that CT mapping of fractures of the tibial plateau would reveal recurrent patterns of fragments and fracture lines, including patterns that do not fit into Schatzker's original classification. One hundred and twenty-seven tibial plateau fractures were retrospectively included in this study. Fracture lines and zones of comminution were graphically superimposed onto an axial template of an intact subarticular tibial plateau to identify major patterns of fracture and comminution. This fracture map of the tibial plateau was subsequently divided into lateral (Schatzker types I, II, and III), medial (Schatzker type IV), and bicondylar (Schatzker types V and VI) fracture maps. This study included seventy-three female and fifty-four male patients (average age, forty-seven years [range, seventeen to ninety-one years]) with a tibial plateau fracture. Sixty-four of the fractures were Schatzker type I, II, or III; fifteen were Schatzker type IV; and forty-eight were Schatzker type V or VI. Analysis of the fracture maps suggested patterns in the Schatzker type-IV, V, and VI fractures beyond those described in Schatzker's original classification. The maps of the 127 fractures revealed four recurrent major fracture features: the lateral split fragment (A), found in 75%; the posteromedial fragment (B), seen in 43%; the tibial tubercle fragment (C), seen in 16%; and a zone of comminution that included the tibial spine and frequently extended to the lateral condyle (D), seen in 28%. Tibial plateau fracture maps show recurrent patterns of fracture lines, revealing four major fracture characteristics. An understanding of these recurrent features of tibial plateau fractures can aid surgeons during diagnosis, preoperative planning, and execution of

  7. Prehistoric human settling on the Tibetan Plateau (United States)

    Chen, Fahu; Zhang, Dongju; Dong, Guanghui


    When and where did human first settle down on the Tibetan Plateau is under hot debate among archaeologist, anthropologists, geneticist and paleo-geographers. Based on systematic archaeological, chronological and archaeo-botanical studies of 53 sites in Northeastern Tibetan Plateau, we propose that agriculture facilitated human permanent settlement on the Tibetan Plateau initially since 5200 years ago below 2500 masl and since 3600 years ago up to around 4000 masl, possibly assisted by domesticated animals (Chen et al. 2015). By studying hand- and footprints in Chusang, Meyer et al. (2016) argue that hunter-gatherers permanently occupied central Tibetan Plateau in early Holocene without the help of agriculture. However, we think the limited hand- and footprints evidence found in Chusang could indicate no more than prehistoric hunter-gatherers presence on the remote central Tibetan Plateau in the early Holocene. In addition, by reviewing all the published archaeological data, we propose that human migrated to the Tibetan Plateau from the last Deglacial period to late Holocene mainly from North China via Yellow River valley and its tributary valleys in the Northeastern Tibetan Plateau (NETP). This migration is constituted of four stages (Upper Paleolithic, Epi-Paleolithic, Neolithic and Bronze Age) when human adapted to the high altitude environment and climate change with different strategies and techniques. Particularly, the prevail of microlithic technology in North China provoked hunter-gatherers' first visit to the NETP in relatively ameliorated last Deglacial period, and the the quick development of millet farming and subsequent mixed barley-wheat farming and sheep herding facilitated farmers and herders permanently settled in Tibetan Plateau, even above 3000 masl, during mid- and late Holocene. References: Chen et al., 2015. Agriculture facilitated permanent human occupation of the Tibetan Plateau after 3600 BP. Science, 347: 248-250. Meyer et al., 2016

  8. Residential Energy Efficiency Potential: Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Eric J [National Renewable Energy Laboratory (NREL), Golden, CO (United States)


    Energy used by Colorado single-family homes that can be saved through cost-effective improvements. Prepared by Eric Wilson and Noel Merket, NREL, and Erin Boyd, U.S. Department of Energy Office of Energy Policy and Systems Analysis.




  10. Why Colorado Is Testing Teachers. (United States)

    Frazier, Calvin M.


    Colorado now requires applicants for teaching certificates to pass a basic skills test in spelling, English language usage, and mathematics and to demonstrate acceptable speaking ability. Student teachers must also complete this screening. Applicants have four chances to complete the test. (MLF)

  11. Observation of the Zero Hall Plateau in a Quantum Anomalous Hall Insulator

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Yang; Feng, Xiao; Ou, Yunbo; Wang, Jing; Liu, Chang; Zhang, Liguo; Zhao, Dongyang; Jiang, Gaoyuan; Zhang, Shou-Cheng; He, Ke; Ma, Xucun; Xue, Qi-Kun; Wang, Yayu


    We report experimental investigations on the quantum phase transition between the two opposite Hall plateaus of a quantum anomalous Hall insulator. We observe a well-defined plateau with zero Hall conductivity over a range of magnetic field around coercivity when the magnetization reverses. The features of the zero Hall plateau are shown to be closely related to that of the quantum anomalous Hall effect, but its temperature evolution exhibits a significant difference from the network model for a conventional quantum Hall plateau transition. We propose that the chiral edge states residing at the magnetic domain boundaries, which are unique to a quantum anomalous Hall insulator, are responsible for the novel features of the zero Hall plateau.

  12. Giant plateau in the terahertz Faraday angle in gated Bi2Se3 (United States)

    Jenkins, Gregory S.; Sushkov, Andrei B.; Schmadel, Don C.; Kim, M.-H.; Brahlek, Matthew; Bansal, Namrata; Oh, Seongshik; Drew, H. Dennis


    We report gated terahertz Faraday angle measurements on epitaxial Bi2Se3 thin films capped with In2Se3. A plateau is observed in the real part of the Faraday angle at an onset gate voltage corresponding to no band bending at the surface, which persists into accumulation. The plateau is two orders of magnitude flatter than the step size expected from a single Landau level in the low-frequency limit, quantized in units of the fine structure constant. At 8 T, the plateau extends over a range of gate voltage that spans an electron density greater than 14 times the quantum flux density. Both the imaginary part of the Faraday angle and transmission measurements indicate dissipative off-axis and longitudinal conductivity channels associated with the plateau.

  13. Hydrology of area 53, Northern Great Plains and Rocky Mountain coal provinces, Colorado, Wyoming, and Utah (United States)

    Driver, N.E.; Norris, J.M.; Kuhn, Gerhard; ,


    Hydrologic information and analysis are needed to aid in decisions to lease Federally owned coal and for the preparation of the necessary Environmental Assessments and Impact Study Reports. This need has become even more critical with the enactment of the Surface Mining Control and Reclamation Act of 1977 (Public Law 95-87). This report, one in a series of nationwide coal province reports, presents information thematically by describing single hydrologic topics through the use of brief texts and accompanying maps, graphs, or other illustrations. The report broadly characterizes the hydrology of Area 53 in northwestern Colorado, south-central Wyoming, and northeastern Utah. The report area, located primarily in the Wyoming Basin and Colorado Plateau physiographic provinces, consists of 14,650 square miles of diverse geology, topography, and climate. This diversity results in contrasting hydrologic characteristics. The two major rivers, the Yampa and the White Rivers, originate in humid granitic and basaltic mountains, then flow over sedimentary rocks underlying semiarid basins to their respective confluences with the Green River. Altitudes range from 4,800 to greater than 12,000 feet above sea level. Annual precipitation in the mountains, as much as 60 inches, is generally in the form of snow. Snowmelt produces most streamflow. Precipitation in the lower altitude sedimentary basins, ranging from 8 to 16 inches, is generally insufficient to sustain streamflow; therefore, most streams originating in the basins (where most of the streams in coal-mining areas originate) are ephemeral. Streamflow quality is best in the mountains where dissolved-solids concentrations generally are small. As streams flow across the sedimentary basins, mineral dissolution from the sedimentary rocks and irrigation water with high mineral content increase the dissolved-solids concentrations in a downstream direction. Due to the semiarid climate of the basins, soils are not adequately leached

  14. Depth to Coal Mining in the Colorado Front Range (frimndpthu) (United States)

    U.S. Geological Survey, Department of the Interior — This file is a digital polygon representation of the depth to (overburden above) abandoned underground coal mines in the Boulder-Weld coal field, Denver Basin,...

  15. Wildfire risk transmission in the Colorado Front Range, USA (United States)

    Jessica R. Haas; David E. Calkin; Matthew P. Thompson


    Wildfires are a global phenomenon that in some circumstances can result in human casualties, economic loss, and ecosystem service degradation. In this article we spatially identify wildfire risk transmission pathways and locate the areas of highest exposure of human populations to wildland fires under severe, but not uncommon, weather events. We quantify varying levels...

  16. USGS Interactive Map of the Colorado Front Range Infrastructure Resources (United States)

    U.S. Geological Survey, Department of the Interior — Infrastructure, such as roads, airports, water and energy transmission and distribution facilities, sewage treatment plants, and many other facilities, is vital to...

  17. Ammonia sources, transport, and deposition in northern Colorado (United States)

    Collett, J. L., Jr.; Benedict, K. B.; Li, Y.; Shao, Y.; Wentworth, G.; Sullivan, A.; Evanoski-Cole, A. R.; Bangs, E.; Murphy, J. G.; Schichtel, B. A.


    Expanded measurements of ammonia in northern Colorado are providing new insight into ammonia sources in the region, their spatial variability, and their contributions to reactive nitrogen deposition in sensitive regions such as Rocky Mountain National Park (RMNP). Regional ammonia concentrations have been examined through a combination of a passive ammonia monitoring network, through mobile measurements, and through an east-west transect of real-time ammonia monitors stretching from the agricultural source region of NE Colorado through the Rocky Mountain foothills west of the Front Range urban corridor, to Rocky Mountain National Park. Several years of ammonia observations in NE Colorado reveal considerable concentration variability, with the highest concentrations observed near animal feeding observations. Multi-year concentration increases have been observed at some locations and significant decreases at other locations, but most sites exhibit no significant long-term trends. Ammonia concentrations in RMNP are strongly influenced by episodic transport from ammonia-rich NE Colorado, but an imprtant influence is also observed from wildfire emissions. Local recylcing of boundary layer ammonia through formation and evaporation of dew also exerts a strong influence on local concentrations, a phenomenon that has received little prior attention.

  18. Systeemomschrijving “Plateau 2.0”

    NARCIS (Netherlands)

    Hoofs, Anita


    En varkenshok met plateau is een hok waarin varkens vrij beschikken over twee verblijfsniveaus, één op de begane grond en één op het plateau. Varkens kunnen gemakkelijk het plateau op - en aflopen via een trap. Bij toepassing van een plateau, dat voldoet aan de systeemomschrijving, mag het

  19. Colorado Desert Vegetation (United States)

    California Department of Resources — CDF-FRAP compiled the 'best available' land cover data into a single data layer, to support the various analyses required for the 2002 Forest and Range Assessment....

  20. The Colorado Lightning Mapping Array (United States)

    Rison, W.; Krehbiel, P. R.; Thomas, R. J.; Rodeheffer, D.; Fuchs, B.


    A fifteen station Lightning Mapping Array (LMA) was installed in northern Colorado in the spring of 2012. While the driving force for the array was to produce 3-dimensional lightning data to support the Deep Convective Clouds and Chemistry (DC3) Experiment (Barth, this conference), data from the array are being used for several other projects. These include: electrification studies in conjunction with the CSU CHILL radar (Lang et al, this conference); observations of the parent lightning discharges of sprites (Lyons et al, this conference); trying to detect upward discharges triggered by wind turbines, characterizing conditions in which aircraft flying through clouds produce discharges which can be detected by the LMA, and other opportunities, such as observations of lightning in pyrocumulus clouds produced by the High Park Fire west of Fort Collins, CO. All the COLMA stations are solar-powered, and use broadband cellular modems for data communications. This makes the stations completely self-contained and autonomous, allowing a station to be installed anywhere a cellular signal is available. Because most of the stations were installed well away from anthropogenic noise sources, the COLMA is very sensitive. This is evidenced by the numerous plane tracks detected in its the vicinity. The diameter, D, of the COLMA is about 100 km, significantly larger than other LMAs. Because the error in the radial distance r is proportional to (r/D)2, and the error in the altitude z is proportional to (z/D)2, the larger array diameter greatly expands the usable range of the COLMA. The COLMA is able to detect and characterize lighting flashes to a distance of about 350 km from the array center. In addition to a web-based display (, geo-referenced images are produced and updated at one-minute intervals. These geo-referenced images can be used to overlay the real-time lightning data on Google Earth and other mapping software. These displays were used by the DC3

  1. Bicondylar tibial plateau fracture after posterior cruciate ligament reconstruction. (United States)

    Griesser, Michael J; McCoy, Brett W; Hussain, Waqas M; Saluan, Paul


    The authors present a report of a bicondylar tibial plateau fracture in an adolescent athlete after posterior cruciate ligament (PCL) reconstruction. The procedure was performed via arthroscopic transtibial PCL reconstruction with quadrupled semi-tendinosus and gracilis autograft. The patient recovered uneventfully postoperatively and was able to participate in high-level sports activity, such as baseball and track, with no limitations, no subjective complaints, and no episodes of instability. He continued to be asymptomatic up to 3.5 years postoperatively. Almost 4 years postoperatively, the patient reinjured the left knee during recreational noncontact football and was seen emergently. Plain radiographs, magnetic resonance image scan, and computed tomography scan at the time of injury showed a bicondylar tibial plateau fracture with intra-articular involvement. Operative intervention was undertaken for open reduction and internal fixation of the bicondylar tibial plateau fracture. A plate was placed along the medial aspect of the tibia with locking and nonlocking screws, and the joint line was restored appropriately. The patient recovered uneventfully and at the most recent follow-up had full active and passive range of motion, had no subjective or objective evidence of instability, and had returned to full activity with no restrictions. The patient had no history of multiple fractures or any medical or pharmacologic history that predisposed him to decreased bone density. This case shows a unique possible complication after transtibial PCL reconstruction in an adolescent patient. Copyright 2015, SLACK Incorporated.

  2. Soil Erosion Study on the Chinese Loess Plateau (United States)

    Hu, Yaxian; Guo, Shengli; Kuhn, Nikolaus


    The Chinese Loess Plateau, because of its highly erodible loess soils and hilly topography, has been extensively studied by soil scientists and geomorphologists. As a research hotspot, there are five national-level field stations across the Loess Plateau, with hundreds of erosion plots set up with various sizes, lengths, slope angles and vegetation covers. In addition, huge indoor rain simulation facilities exist in in different institutes which can provide rainfall simulations under a wide range of controlled conditions. Consequently, national-level restoration projects have achieved tremendous improvements in curbing soil erosion and improving regional agro-ecosystem, mostly by afforestation and soil rehabilitation. However, when implementing the advanced techniques and models that have been widely applied in the rest of the world, there are often regional considerations, which demand new approaches to overcome. One example are the unintentional impacts of restoration efforts, such as the establishment of apple orchards. Over 20 years, they have caused an increase in soil erodibility and lowered local ground water levels. Neither before the introduction of this landscape rehabilitation technique, nor now, has the impact of intensive fruit production been systematically studied, despite lending itself to systematic experiments. The lack of research is attributed to the general idea that trees protect soils and improve environmental services. This presentation identifies several such specific regional environmental issues associated with soil erosion on the Loess Plateau and discusses strategies to avoid missing important research questions.

  3. An Innovative Intra-articular Osteotomy in the Treatment of Posterolateral Tibial Plateau Fracture Malunion. (United States)

    Wang, Yukai; Luo, Congfeng; Hu, Chengfang; Sun, Hui; Zhan, Yu


    Posterolateral tibial plateau fractures are not uncommon and the diagnosis can be easily missed. The treatment is technically demanding, which can easily lead to malunion of the posterolateral tibial plateau fracture. Here, we describe an innovative intra-articular osteotomy for the treatment of posterolateral tibial plateau fracture malunion. From 2010 through 2012, 13 patients with a posterolateral tibial plateau fracture malunion were treated in our trauma center. The patients were referred because of instability or knee pain. The instability was confirmed by physical examinations preoperatively. The depression malunion and lower limb alignment were evaluated on X-rays and computed tomography scans. All posterolateral tibial plateau fracture malunions were treated with an innovative intra-articular osteotomy via an extended anterolateral approach. The mean follow-up was 19.6 months (range, 14-28 months). The posterolateral osteotomy healed at an average of 15.1 weeks. The depression malunion was corrected in all patients, which was from 15.4 mm preoperatively to 3.3 mm at 12 months postoperatively. The average Lysholm, Knee Society Score, and visual analog scale scores were 91.7, 92.5, and 0.5, respectively. No loss of reduction, nonunion, or wound infection was observed. An innovative intra-articular osteotomy via an extended anterolateral approach is an effective treatment for posterolateral tibial plateau fracture malunion. The treatment achieved satisfactory functional results and knee stability restoration. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  4. Inflammatory cytokine response is greater in acute tibial plafond fractures than acute tibial plateau fractures. (United States)

    Haller, Justin M; Marchand, Lucas; Rothberg, David L; Kubiak, Erik N; Higgins, Thomas F


    The purpose of the study was to compare the inflammatory cytokine and matrix metalloproteinase (MMP) concentrations in synovial fluid after acute plafond fracture with acute tibial plateau fracture. Between December 2011 and August 2014, we prospectively enrolled patients with acute tibial plateau and plafond fractures. Synovial fluid aspirations were obtained from injured and uninjured joints. The concentrations of IL-1β, IL-1RA, IL-6, IL-8, IL-10, MCP-1, TNF-α, MMP-1, -3, -9, -10, -12, and -13 were quantified using multiplex assays. A Bonferroni correction was used so that the adjusted alpha level for significance was p plateau fractures and 19 plafond fractures. Mean patient age was 42 years (range, 20-60) and 64% were male patients. There were 24 low-energy (OTA 41B) plateau fractures and eight low-energy (OTA 43B) plafond fractures. There were 21 high-energy (6 OTA 41B3 and 15 OTA 41C) plateau fractures and 11 high-energy (OTA43C) plafond fractures. All cytokines and MMPs except MMP-13 were significantly elevated in plafond fractures compared to uninjured ankles. When comparing acutely injured joints, IL-8 (p plateau fractures. Concentrations of IL-1RA (p = 0.008) and MCP-1 (p = 0.005) were higher in plafond fractures, and MMP-10 (p = 0.01) was higher in plateau fractures, but these differences did not reach significance. In conclusion, several cytokines and MMPs were significantly elevated in acute plafond fractures as compared to acute tibial plateau fractures. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  5. 78 FR 72700 - Notice of Inventory Completion: History Colorado, formerly Colorado Historical Society, Denver, CO (United States)


    ... and the Pueblo of Taos, New Mexico, were invited to consult but did not participate. History and... National Park Service Notice of Inventory Completion: History Colorado, formerly Colorado Historical Society, Denver, CO AGENCY: National Park Service, Interior. ACTION: Notice. SUMMARY: History Colorado has...

  6. Los 'Colorados': Etnohistoria y Toponimia

    NARCIS (Netherlands)

    Gómez-Rendón, J.


    Los "colorados" comprendían varios grupos étnicos emparentados etnolingüísticamente que ocupaban el piedemonte andino occidental desde El Carchi hasta Bolívar así como las tierras bajas del Pacífico en los sistemas hidrográficos de los ríos Esmeraldas y Guayas. Aunque la ocupación "colorada" de

  7. Academia del Aire, Colorado (USA

    Directory of Open Access Journals (Sweden)

    Arquitectos, Skidmore, Ownings y Merrill


    Full Text Available Este bello complejo arquitectónico, de depuradas y modernas líneas de amplio y pródigo programa, está situado en una dilatada meseta natural, al pie mismo de la majestuosa orografía de las Montañas Rocosas, a unos trece kilómetros de las maravillosas cascadas de Colorado Springs.

  8. Corrections to holographic entanglement plateau (United States)

    Chen, Bin; Li, Zhibin; Zhang, Jia-ju


    We investigate the robustness of the Araki-Lieb inequality in a two-dimensional (2D) conformal field theory (CFT) on torus. The inequality requires that Δ S = S( L) - | S( L - ℓ) - S( ℓ)| is nonnegative, where S( L) is the thermal entropy and S( L - ℓ), S( ℓ) are the entanglement entropies. Holographically there is an entanglement plateau in the BTZ black hole background, which means that there exists a critical length such that when ℓ ≤ ℓ c the inequality saturates Δ S =0. In thermal AdS background, the holographic entanglement entropy leads to Δ S = 0 for arbitrary ℓ. We compute the next-to-leading order contributions to Δ S in the large central charge CFT at both high and low temperatures. In both cases we show that Δ S is strictly positive except for ℓ = 0 or ℓ = L. This turns out to be true for any 2D CFT. In calculating the single interval entanglement entropy in a thermal state, we develop new techniques to simplify the computation. At a high temperature, we ignore the finite size correction such that the problem is related to the entanglement entropy of double intervals on a complex plane. As a result, we show that the leading contribution from a primary module takes a universal form. At a low temperature, we show that the leading thermal correction to the entanglement entropy from a primary module does not take a universal form, depending on the details of the theory.

  9. Colorado Plateau Rapid Ecoregion Assessment Conservation Elements - Terrestrial Species: Burrowing Owl (United States)

    Bureau of Land Management, Department of the Interior — This map shows the potential current distribution of burrowing owl, in the context of current and near-term terrestrial intactness and long-term potential for...

  10. Colorado Plateau Rapid Ecoregion Assessment Conservation Elements - Terrestrial Species: Greater Sage-Grouse Limiting Factors (United States)

    Bureau of Land Management, Department of the Interior — This map presents limiting factors for Greater Sage-grouse for an area in the northern part of the ecoregion. This was used for the sage-grouse insert in the final...

  11. Colorado Plateau Rapid Ecoregion Assessment Conservation Elements - Terrestrial Species: Gunnison Sage-Grouse (United States)

    Bureau of Land Management, Department of the Interior — This map shows the potential current distribution of Gunnison sage-grouse, in the context of current and near-term terrestrial intactness and long-term potential for...

  12. Colorado Plateau Rapid Ecoregion Assessment Conservation Elements - Terrestrial Species: Greater Sage-Grouse (United States)

    Bureau of Land Management, Department of the Interior — This map shows the potential current distribution of Greater Sage-grouse, in the context of current and near-term terrestrial intactness and long-term potential for...

  13. 78 FR 13373 - Notice of Availability of the Colorado Plateau Rapid Ecoregional Assessment (United States)


    ... stakeholders to consider in resource planning and decision-making processes, such as Resource Management Plans... to contact the above individuals during business hours. The FIRS is available 24 hours a day, 7 days... normal business hours. SUPPLEMENTARY INFORMATION: This notice announces the availability of the first REA...

  14. Utah lotus: North American legume for rangeland revegetation in southern Great Basin and Colorado Plateau (United States)

    Utah lotus (Lotus utahensis Ottley) is a North American leguminous forb that may hold promise for rangeland revegetation in the western USA for diversifying planting mixtures, attracting pollinators, providing high quality forage, and expanding habitats for insects needed by sage grouse chicks. We ...

  15. Comparative diversity and composition of cyanobacteria in three predominate soil crusts of the Colorado Plateau (United States)

    Redfield, Elizabeth; Barns, Susan M.; Belnap, Jayne; Daane, Lori L.; Kuske, Cheryl R.


    Terminal restriction fragment length polymorphism (TRF or T-RFLP) analysis and 16S rDNA sequence analysis from clone libraries were used to examine cyanobacterial diversity in three types of predominant soil crusts in an arid grassland. Total DNA was extracted from cyanobacteria-, lichen-, or moss-dominated crusts that represent different successional stages in crust development, and which contribute different amounts of carbon and nitrogen into the ecosystem. Cyanobacterial 16S rRNA genes were amplified by PCR using cyanobacteria-specific 16S rDNA primers. Both TRF and clone sequence analyses indicated that the cyanobacterial crust type is dominated by strains of Microcoleus vaginatus, but also contains other cyanobacterial genera. In the moss crust, M. vaginatus-related sequences were also the most abundant types, together with sequences from moss chloroplasts. In contrast, sequences obtained from the lichen crust were surprisingly diverse, representing numerous genera, but including only two from M. vaginatus relatives. By obtaining clone sequence information, we were able to infer the composition of many peaks observed in TRF profiles, and all peaks predicted for clone sequences were observed in TRF analysis. This study provides the first TRF analysis of biological soil crusts and the first DNA-based comparison of cyanobacterial diversity between lichen-, cyano- and moss-dominated crusts. Results indicate that for this phylogenetic group, TRF analysis, in conjunction with limited sequence analysis, can provide accurate information about the composition and relative abundance of cyanobacterial types in soil crust communities.

  16. Colorado Plateau Rapid Ecoregion Assessment Conservation Elements - White-Tailed Prairie Dog (United States)

    Bureau of Land Management, Department of the Interior — This map shows the potential current distribution of white-tailed prairie dog, in the context of current and near-term terrestrial intactness and long-term potential...

  17. Colorado Plateau Rapid Ecoregion Assessment Terrestrial Intactness and Potential For Change (United States)

    Bureau of Land Management, Department of the Interior — This map shows current and near-term terrestrial intactness, as well as long term potential for development and climate change. These datasets are the results of a...

  18. Colorado Plateau Rapid Ecoregion Assessment Terrestrial Intactness and Potential For Change (HUC5) (United States)

    Bureau of Land Management, Department of the Interior — This map shows current and near-term terrestrial intactness, as well as long term potential for development and climate change. These datasets are the results of a...

  19. Survey of literature relating to energy development in Utah's Colorado Plateau

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, A.


    This study examines various energy resources in Utah including oil impregnated rocks (oil shale and oil sand deposits), geothermal, coal, uranium, oil and natural gas in terms of the following dimensions: resurce potential and location; resource technology, development and production status; resource development requirements; potential environmental and socio-economic impacts; and transportation tradeoffs. The advantages of minemouth power plants in comparison to combined cycle or hybrid power plants are also examined. Annotative bibliographies of the energy resources are presented in the appendices. Specific topics summarized in these annotative bibliographies include: economics, environmental impacts, water requirements, production technology, and siting requirements.

  20. Correlation of upper Triassic strata between southern Colorado Plateau and southern High Plains, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Lucas, S.G. (New Mexico Museum of Natural History, Albuquerque (USA))


    Almost 600 m of Upper Triassic strata are exposed in the Hagan basin. They pertain to the basal Agua Zarca member of the Chinle Formation (as much as 80 m), overlain by about 500 m of mud-rock-dominated red beds of the Petrified Forest Member of the Chinle Formation. The top of the Triassic section here is the 5.5-24 m-thick Correo Sandstone Bed of Chinle Formation, which is disconformably overlain by the medial silty member of the Middle Jurassic Entrada Sandstone. At Lamy, approximately 370 m of Upper Triassic strata represent the westernmost outcrops of the Triassic section typical of the Tucumcari basin. This Triassic section consists of about 140 m of Santa Rosa Formation (divisible into three members) overlain by a mud-rock-dominated section (Chinle Formation) split by a medial sandy interval, the Cuervo member (Trujillo Formation of the Palo Duro basin). The youngest Triassic strata near Lamy are rhythmically bedded sediments of the Redonda Member. Based on lithologic similarity, stratigraphic position, and limited paleontological data, the central New Mexico Upper Triassic strata support for the following correlations (from west to east): (1) Shinarump = Agua Zarca = Santa Rosa; (2) lower Petrified Forest = lower shale member of the Chinle = Tecovas; (3) Sonsela = Poleo = Cuervo = Trujillo; (4) upper Petrified Forest = upper shale member of the Chinle; and (5) Owl Rock = Redonda = Correo. These correlations reflect homotaxis of sedimentary cycles across a broad region of the southern Western Interior during the Late Triassic.

  1. Applying threshold concepts to conservation management of dryland ecosystems: Case studies on the Colorado Plateau (United States)

    Bowker, Matthew A.; Miller, Mark E.; Garman, Steven L.; Belote, Travis; Guntenspergen, Glenn R.


    Ecosystems may occupy functionally distinct alternative states, some of which are more or less desirable from a management standpoint. Transitions from state to state are usually associated with a particular trigger or sequence of triggers, such as the addition or subtraction of a disturbance. Transitions are often not linear, rather it is common to see an abrupt transition come about even though the trigger increases only incrementally; these are examples of threshold behaviors. An ideal monitoring program, such as the National Park Service’s Inventory and Monitoring Program, would quantify triggers, and be able to inform managers when measurements of a trigger are approaching a threshold so that management action can avoid an unwanted state transition. Unfortunately, both triggers and the threshold points at which state transitions occur are generally only partially known. Using case studies, we advance a general procedure to help identify triggers and estimate where threshold dynamics may occur. Our procedure is as follows: (1) Operationally define the ecosystem type being considered; we suggest that the ecological site concept of the Natural Resource Conservation Service is a useful system, (2) Using all available a priori knowledge to develop a state-and-transition model (STM), which defines possible ecosystem states, plausible transitions among them and likely triggers, (3) Validate the STM by verifying the existence of its states to the greatest degree possible, (4) Use the STM model to identify transitions and triggers likely to be detectable by a monitoring program, and estimate to the greatest degree possible the value of a measurable indicator of a trigger at the point that a state transition is imminent (tipping point), and values that may indicate when management intervention should be considered (assessment points). We illustrate two different methods for attaining these goals using a data-rich case study in Canyonlands National Park, and a data-poor case study in Wupatki National Monument. In the data-rich case, STMs are validated and revised, and tipping and assessment points are estimated using statistical analysis of data. In the data-poor case, we develop an iterative expert opinion survey approach to validate the degree of confidence in an STM, revise the model, identify lack of confidence in specific model components, and create reasonable first approximations of tipping and assessment points, which can later be refined when more data are available. Our goal should be to develop the best set of models possible given the level of information available to support decisions, which is often not much. The approach presented here offers a flexible means of achieving this goal, and determining specific research areas in need of study.

  2. Understanding a rapid transition in subistence regimes on the Tibetan Plateau (United States)

    DAlpoim Guedes, J. A.


    Moving agriculture into the highlands of the Tibetan Plateau, was a challenging process. Short growing seasons, cold winters and spring frost mean that the Tibetan plateau presented considerable challenges to the movement of domesticates into this region. In this paper, we describe the creation and employment of crop niche models aimed at outlining the constraints associated with practicing a range of different crops on the Tibetan plateau and in the foothills of the Himalayas. These models contribute to explaining a profound change in both settlement patterns and in subsistence regimes on the Eastern Tibetan Plateau when a shift from a millet-based agriculture to wheat and barley based agro-pastoralism took place c. 2000 cal. BC. Using a model that predicts the changing distribution of crop niches across the area, we examine the role that changes in ancient climate could have played in the reversal of subsistence practices in this area. We argue that cooling temperatures at the end of the Holocene climatic optimum made it impossible for early farmers on the margins of the Tibetan Plateau to continue growing millets. It was only when two frost tolerant crops: wheat and barley arrived on the Plateau that agriculture was able to once again become implanted in select river valleys of the Plateau. We also identify the little ice age as a period that likely had a substantial impact on Tibetan agriculture. Using a range of different projected scenarios of climate change, we ask what insights earlier and warmer periods of time may hold for informing new subsistence strategies on the roof of the world.

  3. Shear wave anisotropy beneath the Tibetan Plateau (United States)

    McNamara, Daniel E.; Owens, Thomas J.; Silver, Paul G.; Wu, Frances T.


    Eleven broadband digital seismic stations were deployed across the central Tibetan Plateau in the first extensive passive-source experiment attempted within the Tibetan Plateau. One year of recording resulted in 186 event-station pairs which we analyze to determine the characteristics of shear wave splitting in the upper mantle beneath the array. Measurements of the fast polarization direction (phi) and delay time (delta-t) for SKS and direct S arrivals reveal systematic variations along the north-south oriented array. In the north central region of the plateau, very large delay times are observed at three stations, the largest of which is BUDO with delta-t = 2.4 s. However, at TUNL, which is off the northern edge of the plateau and 110 km from BUDO, and at sites in the south central plateau, delta-t decreases by nearly a factor of 3. We also observe a systematic rotation of phi from about 45 deg (NE) to 90 deg (E-W) from south to north along the array. A previously identified zone of inefficient Sn propagation correlates well with our region of large delta-t observations. The large delay times suggest that a relatively high number of anisotropic crystals are preferentially alligned within the mantle-lid, beneath the north central portion of the Tibetan Plateau. In most cases, fast polarization directions appear to be parallel to surface geologic features suggesting as much as 200 km of the upper mantle has been involved in the collisional deformation that has produced the Tibetan Plateau.

  4. The Permian–Triassic transition in Colorado (United States)

    Hagadorn, James S.; Whitely, Karen R.; Lahey, Bonita L.; Henderson, Charles M.; Holm-Denoma, Christopher S.


    The Lykins Formation and its equivalents in Colorado are a stratigraphically poorly constrained suite of redbeds and intercalated stromatolitic carbonates, which is hypothesized to span the Permian-Triassic boundary. Herein we present a preliminary detrital zircon geochronology, new fossil occurrences, and δ13C chemostratigraphy for exposures along the Front Range and in southeastern Colorado, to refine understanding of the unit's age and depositional history.Detrital zircons from the uppermost Lykins Formation and an overlying eolianite consist of a complex and highly diverse primary and multi-cycle grain population transported from Laurentian and Gondwanan terranes, potentially both by wind and water. Youngest concordant zircons do not rule out deposition of the uppermost Lykins Formation during a portion of Early Triassic time. Conodonts from the lower Lykins Formation require Middle Permian (Guadalupian) deposition. Conodont alteration indices of 1 indicate the unit has a shallow burial history and is amenable to paleomagnetic inquiry. Conodonts, together with other vertebrate, invertebrate, microfossil, and trace fossils, suggest a very shallow to emergent marine origin for the unit's most substantial carbonates, and hint at a marine origin for the unit's intercalated gypsum-anhydrite members. Chemostratigraphy corroborates field evidence of emergence and karst development capping certain units, like the Forelle Limestone Member of the Lykins Formation, where potential sequence boundaries appear to be punctuated by a short-lived meteoric signature.Results presented here are a progress report of ongoing work in these successions. This field trip consists of a brief tour through exposures of the Lykins Formation, in which we will examine well-known localities as well as view new ones for which we seek insights.

  5. Cost effectiveness of the 1993 Model Energy Code in Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Lucas, R.G.


    This report documents an analysis of the cost effectiveness of the Council of American Building Officials` 1993 Model Energy Code (MEC) building thermal-envelope requirements for single-family homes in Colorado. The goal of this analysis was to compare the cost effectiveness of the 1993 MEC to current construction practice in Colorado based on an objective methodology that determined the total life-cycle cost associated with complying with the 1993 MEC. This analysis was performed for the range of Colorado climates. The costs and benefits of complying with the 1993 NIEC were estimated from the consumer`s perspective. The time when the homeowner realizes net cash savings (net positive cash flow) for homes built in accordance with the 1993 MEC was estimated to vary from 0.9 year in Steamboat Springs to 2.4 years in Denver. Compliance with the 1993 MEC was estimated to increase first costs by $1190 to $2274, resulting in an incremental down payment increase of $119 to $227 (at 10% down). The net present value of all costs and benefits to the home buyer, accounting for the mortgage and taxes, varied from a savings of $1772 in Springfield to a savings of $6614 in Steamboat Springs. The ratio of benefits to costs ranged from 2.3 in Denver to 3.8 in Steamboat Springs.

  6. New Exploration of Kerguelen Plateau Margins (United States)

    Vially, R.; Roest, W. R.; Loubrieu, B.; Courreges, E.; Lecomte, J.; Patriat, M.; Pierre, D.; Schaming, M.; Schmitz, J.


    France ratified the United Nations Convention on the Law of the Sea in 1996, and has since undertaken an ambitious program of bathymetric and seismic data acquisition (EXTRAPLAC Program) to support claims for the extension of the legal continental shelf, in accordance with Article 76 of this convention. For this purpose, three oceanographic surveys took place on board of the R/V Marion Dufresne II on the Kerguelen Plateau, in Southern Indian Ocean: MD137-Kergueplac1 (February 2004), MD150-Kergueplac2 (October 2005) and MD165-Kergueplac3 (January 2008), operated by the French Polar Institute. Thus, more than 20 000 km of multibeam bathymetric, magnetic and gravimetric profiles, and almost 6 000 km of seismic profiles where acquired during a total of 62 days of survey in the study area. Ifremer's "rapid seismic" system was used, comprised of 4 guns and a 24 trace digital streamer, operated at speeds up to 10 knots. In addition to its use for the Extraplac Program, the data set issued from these surveys gives the opportunity to improve our knowledge of the structure of the Kerguelen Plateau and more particularly of its complex margins. In this poster, we will show the high resolution bathymetry (200 m) data set, that allows us to specify the irregular morphology of the sea floor in the north Kerguelen Plateau, characterised by ridges and volcanoes chains, radial to the plateau, that intersect the oceanic basin on the NE edge of the Kerguelen Plateau. We will also show magnetic and gravity data, which help us to understand the setting up of the oceanic plateau and the kinematics reconstructions. The seismic profiles show that the acoustic basement of the plateau is not much tectonised, and displays a very smooth texture, clearly contrasting it from typical oceanic basement. Both along the edge of the plateau as in the abyssal plain, sediments have variable thicknesses. The sediments on the margin of the plateau are up to 1200 meters thick and display irregular

  7. Colorado School Health Education Survey 1992. Report. (United States)

    Utah Univ., Salt Lake City. Health Education Dept.

    This report summarizes and interprets the results of the 1992 Colorado School Health Education Survey, which targets public secondary schools with grades 7 through 12. Results provide a basic sketch of the extent of HIV (Human Immunodeficiency Virus) prevention and health education being implemented in Colorado's secondary schools. The survey,…

  8. High School Athletics: A Colorado Story. (United States)

    Yaffe, Elaine


    Considers the costs and benefits of high school sports programs as typified by those in Colorado Springs (Colorado), informally assessing the attitudes of players, coaches, parents, and district administrators concerning the role of athletics in the educational setting and in the community at large. (PGD)

  9. 78 FR 52600 - Colorado Disaster # CO-00054 (United States)


    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Colorado Disaster CO-00054 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a notice of an Administrative declaration of a disaster for the State of Colorado dated 08/14...

  10. 78 FR 55770 - Colorado Disaster #CO-00062 (United States)


    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Colorado Disaster CO-00062 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a notice of an Administrative declaration of a disaster for the State of Colorado dated 08/30...

  11. 75 FR 60151 - Colorado Disaster # CO-00033 (United States)


    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Colorado Disaster CO-00033 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a notice of an Administrative declaration of a disaster for the State of COLORADO dated 09/23...

  12. 77 FR 48197 - Colorado Disaster #CO-00046 (United States)


    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Colorado Disaster CO-00046 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a notice of an Administrative declaration of a disaster for the State of Colorado dated 08/07...

  13. 78 FR 57923 - Colorado Disaster #CO-00065 (United States)


    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Colorado Disaster CO-00065 AGENCY: Small Business Administration. ACTION: Notice. SUMMARY: This is a Notice of the Presidential declaration of a major disaster for the State of Colorado (FEMA-4145-DR...

  14. Libraries in Colorado: MedlinePlus (United States)

    ... JavaScript. Aurora University of Colorado-Anschutz Medical Campus Interlibrary Loan/DocDel Mail Stop A003 Health Sciences Library 12950 ... 2171 Pueblo Colorado State University-Pueblo University Library Interlibrary Loan Dept. 2200 Bonforte Blvd. Pueblo, CO 81001-4901 ...

  15. Conservation status of Colorado River cutthroat trout (United States)

    Michael K. Young; R. Nick Schmal; Thomas W. Kohley; Victoria G. Leonard


    Though biologists recognize that populations of Colorado River cutthroat trout have declined, the magnitude of the loss remains unquantified. We obtained information from state and federal biologists and from state databases to determine the current distribution and status of populations of Colorado River cutthroat trout. Recent population extinctions have been...

  16. Assessing Vulnerability under Uncertainty in the Colorado River Basin: The Colorado River Basin Water Supply and Demand Study (United States)

    Jerla, C.; Adams, P.; Butler, A.; Nowak, K.; Prairie, J. R.


    Spanning parts of the seven states, of Arizona, California, Colorado, New Mexico, Nevada, Utah, and Wyoming, the Colorado River is one of the most critical sources of water in the western United States. Colorado River allocations exceed the long-term supply and since the 1950s, there have been a number of years when the annual water use in the Colorado River Basin exceeded the yield. The Basin is entering its second decade of drought conditions which brings challenges that will only be compounded if projections of climate change are realized. It was against this backdrop that the Colorado River Basin Water Supply and Demand Study was conducted. The Study's objectives are to define current and future imbalances in the Basin over the next 50 years and to develop and analyze adaptation and mitigation strategies to resolve those imbalances. Long-term planning in the Basin involves the integration of uncertainty with respect to a changing climate and other uncertainties such as future demand and how policies may be modified to adapt to changing reliability. The Study adopted a scenario planning approach to address this uncertainty in which thousands of scenarios were developed to encompass a wide range of plausible future water supply and demand conditions. Using Reclamation's long-term planning model, the Colorado River Simulation System, the reliability of the system to meet Basin resource needs under these future conditions was projected both with and without additional future adaptation strategies in place. System reliability metrics were developed in order to define system vulnerabilities, the conditions that lead to those vulnerabilities, and sign posts to indicate if the system is approaching a vulnerable state. Options and strategies that reduce these vulnerabilities and improve system reliability were explored through the development of portfolios. Four portfolios, each with different management strategies, were analyzed to assess their effectiveness at

  17. Reconciling the Isabella Anomaly with Lithosphere Delamination and Basin & Range Extension (United States)

    Straub, J.; Hu, J.; Zhou, Q.; Liu, L.


    The Isabella anomaly is a high-seismic velocity region located below the Sierra Nevada, and its presence has been explained through lithosphere delamination occurring within the past 10-15 Ma and an accreted oceanic micro-plate. Both the lack of consensus on the origin of this high velocity structure and its relation to putative lithospheric delamination and surface uplift requires more careful geodynamic studies. While earlier models of lithosphere delamination neglected the nearby subduction, we attempt to explain this anomaly in the context of delamination related to the subducted slab of the Farallon plate. We design a two-dimensional high-resolution model that extends from the west coast of the United States to the Colorado Plateau, including both the Sierra Nevada and Basin and Range regions. The Basin and Range experienced accelerated extension towards the northwest since 15 Ma, resulting in a topographical pattern with alternating subsidence and uplift; the mechanisms for both the deformation and topography of the region are presently debated. Preliminary results from our 2-D slab-lithosphere interaction model indicate that the foundering of an earlier accreted Farallon slab causes the surface to uplift and the overriding plate to extend. The model can potentially reproduce the main tectonic characteristics of the region, offering new insights on the evolution of the lithosphere-mantle system.

  18. Incision history of Glenwood Canyon, Colorado, USA, from the uranium-series analyses of water-table speleothems

    Directory of Open Access Journals (Sweden)

    Victor J. Polyak


    Full Text Available Uranium-series analyses of water-table-type speleothems from Glenwood Cavern and “cavelets” near the town of Glenwood Springs, Colorado, USA, yield incision rates of the Colorado River in Glenwood Canyon for the last ~1.4 My. The incision rates, calculated from dating cave mammillary and cave folia calcite situated 65 and 90 m above the Colorado River, are 174 ± 30 m/My for the last 0.46 My and 144 ± 30 m/My for the last 0.62 My, respectively. These are consistent with incision rates determined from nearby volcanic deposits. In contrast, δ234U model ages (1.39 ± 0.25 My; 1.36 ± 0.25 My; and 1.72 ± 0.25 My from three different samples of mammillary-like subaqueous crust collected from Glenwood Cavern, 375 m above the Colorado River, yield incision rates of 271 +58/-41 m/My, 277 +61/-42 m/ My, and 218 +36/-27 m/My. These data suggest a relatively fast incision rate between roughly 3 and 1 Ma. The onset of Pleistocene glaciation may have influenced this rate by increasing precipitation on the Colorado Plateau starting at 2.5 Ma. Slowing of incision just before 0.6 Ma could be related to the change in frequency of glacial cycles from 40 to 100 kyr in the middle Pleistocene. This interpretation would suggest that the cutting power of the Colorado River prior to 3 Ma was smaller. An alternative interpretation involving tectonic activity would invoke an episode of fast uplift in the Glenwood Canyon region from 3 to 1 Ma.

  19. Selenium impacts on razorback sucker, Colorado: Colorado River: III. Larvae (United States)

    Hamilton, S.J.; Holley, K.M.; Buhl, K.J.; Bullard, F.A.


    Razorback sucker (Xyrauchen texanus) larvae from adults exposed to selenium at three sites near Grand Junction, Colorado, for 9 months were used in a 30-day waterborne and dietary selenium study. Selenium concentrations in water averaged brine shrimp, 5.6 ??g/g in zooplankton from Horsethief east wetland, 20 ??g/g in zooplankton from Adobe Creek, and 39 ??g/g in zooplankton from North Pond. The lowest survival occurred in larvae fed zooplankton rather than brine shrimp. Survival of larvae at Adobe Creek and North Pond was lower in site water than in reference water. Survival of brood stock larvae was higher than Horsethief larvae even though they received the same water and dietary treatments. Arsenic concentrations in brine shrimp may have resulted in an antagonistic interaction with selenium and reduced adverse effects in larvae. Deformities in larvae from North Pond were similar to those reported for selenium-induced teratogenic deformities in other fish species. Selenium concentrations of ???4.6 ??g/g in food resulted in rapid mortality of larvae from Horsethief, Adobe Creek, and North Pond, and suggested that selenium toxicity in the Colorado River could limit recovery of this endangered fish.

  20. Østre Svartisen plateau icefield: changes in geomorphological and sedimentological signature in response to climate change (United States)

    Boston, Clare; Lovell, Harold; Weber, Paul; Chandler, Benjamin


    Plateau icefields constitute important independent ice dispersal centres both during past glacial periods and in present-day glacial environments. However, their imprint on the landscape is variable, owing to their polythermal nature: the distributions of warm- and cold-based ice, which can also change over time in response to climate fluctuations, leave behind starkly contrasting landform-sediment assemblages. This had led to difficulties in identifying plateau icefields in the Quaternary record due to the paucity of glacial geomorphological and sedimentological evidence for cold-based plateau ice. However, greater understanding of modern plateau icefield landsystems in areas such as Iceland and Norway in recent years has resulted in a number of former icefields being recognised in Britain (e.g. in Dartmoor, the Lake District, Southern Uplands and Monadhliath). In this contribution, we expand the range of modern analogues by investigating the geomorphological and sedimentological signature of Østre Svartisen, an Arctic plateau icefield in Norway, and discuss temporal variations in glacier dynamics and processes of sediment deposition in response to climate warming since the Little Ice Age (c.1750). This evidence helps to refine our understanding of plateau icefield signatures and aid identification of potential loci of former plateau icefield glaciation.

  1. Fractures of the tibial plateau involve similar energies as the tibial pilon but greater articular surface involvement. (United States)

    Dibbern, Kevin; Kempton, Laurence B; Higgins, Thomas F; Morshed, Saam; McKinley, Todd O; Marsh, J Lawrence; Anderson, Donald D


    Patients with tibial pilon fractures have a higher incidence of post-traumatic osteoarthritis than those with fractures of the tibial plateau. This may indicate that pilon fractures present a greater mechanical insult to the joint than do plateau fractures. We tested the hypothesis that fracture energy and articular fracture edge length, two independent indicators of severity, are higher in pilon than plateau fractures. We also evaluated whether clinical fracture classification systems accurately reflect severity. Seventy-five tibial plateau fractures and 52 tibial pilon fractures from a multi-institutional study were selected to span the spectrum of severity. Fracture severity measures were calculated using objective CT-based image analysis methods. The ranges of fracture energies measured for tibial plateau and pilon fractures were 3.2-33.2 Joules (J) and 3.6-32.2 J, respectively, and articular fracture edge lengths were 68.0-493.0 mm and 56.1-288.6 mm, respectively. There were no differences in the fracture energies between the two fracture types, but plateau fractures had greater articular fracture edge lengths (p plateau compared to the tibial pilon. The substantial overlap of severity measures between different fracture classes may well have confounded prior clinical studies relying on fracture classification as a surrogate for severity. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:618-624, 2017. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  2. Peopling the Tibetan plateau: insights from archaeology. (United States)

    Aldenderfer, Mark


    Recent studies of the genome of modern Tibetans have revealed the existence of genes thought to provide an adaptive advantage for life at high elevation. Extrapolating from this discovery, some researchers now argue that a Tibetan-Han split occurred no more than 2750 yr ago. This date is implausible, and in this paper I review the archaeological data from the Tibetan plateau as one means by which to examine the veracity of this assertion. Following a review of the general state of knowledge of Tibetan prehistory, which is unfortunately only at its beginnings, I first examine the data that speak to the initial peopling of the plateau and assess the evidence that traces of their presence can be seen in modern Tibetans today. Although the data are sparse, both archaeology and genetics suggest that the plateau was occupied in the Late Pleistocene, perhaps as early as 30,000 yr ago, and that these early peoples have left a genetic signature in modern Tibetans. I then turn to the evidence for later migrations and focus on the question of the timing of the establishment of permanent settled villages on the plateau. Three areas of the plateau-northeastern Qinghai, extreme eastern Tibet, and the Yarlung Tsangpo valley-have evidence of permanent settlements dating from ca. 6500, 5900, and 3750 yr ago, respectively. These data are not consonant with the 2750 yr ago date for the split and suggest at a minimum that the plateau has been occupied substantially longer and, further, that multiple migrations at different times and from different places have created a complex mosaic of population history. © Mary Ann Liebert, Inc.

  3. Plateau iris secondary to iridociliary cysts. (United States)

    Vila-Arteaga, J; Díaz-Céspedes, R A; Suriano, M M


    We present a case of plateau iris and glaucoma due to multiple unilateral iridociliary cysts. The patient was treated with iridotomy Nd: YAG laser and 360° iridoplasty, without achieving pressure control. Phacoemulsification improved the hypertension. Dynamic gonioscopy and OCT of the anterior chamber was also performed before and after treatment. Iridociliary cysts are a benign condition that can cause iris plateau configuration, and can produce a difficult to treat ocular hypertension. Cystotomy, peripheral iridoplasty, and other treatments have been proposed. Copyright © 2014 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.

  4. Plateau-insulator transition in graphene

    Energy Technology Data Exchange (ETDEWEB)

    Amado, M; Diez, E; Caridad, J M [Laboratorio de Bajas Temperaturas, Universidad de Salamanca, E-37008 Salamanca (Spain); Lopez-Romero, D [CT-ISOM, Universidad Politecnica de Madrid, E-28040 Madrid (Spain); Rossella, F; Dionigi, F; Bellani, V [Dipartimento di Fisica ' A Volta' and CNISM, Universita degli studi di Pavia, I-27100 Pavia (Italy); Maude, D K, E-mail: marioam@fis.ucm.e [Laboratoire National des Champs Magnetiques Intenses, F-38042 Grenoble (France)


    We investigate the quantum Hall effect (QHE) in a graphene sample with Hall-bar geometry close to the Dirac point at high magnetic fields up to 28 T. We have discovered a plateau-insulator quantum phase transition passing from the last plateau for the integer QHE in graphene to an insulator regime {nu}=-2{yields}{nu}=0. The analysis of the temperature dependence of the longitudinal resistance gives a value for the critical exponent associated with the transition equal to {kappa}=0.58{+-}0.03.

  5. Energy Smart Colorado, Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Gitchell, John M. [Program Administrator; Palmer, Adam L. [Program Manager


    Energy Smart Colorado is an energy efficiency program established in 2011 in the central mountain region of Colorado. The program was funded through a grant of $4.9 million, awarded in August 2010 by the U.S. Department of Energy’s Better Buildings Program. As primary grant recipient, Eagle County coordinated program activities, managed the budget, and reported results. Eagle County staff worked closely with local community education and outreach partner Eagle Valley Alliance for Sustainability (now Walking Mountains Science Center) to engage residents in the program. Sub-recipients Pitkin County and Gunnison County assigned local implementation of the program in their regions to their respective community efficiency organizations, Community Office for Resource Efficiency (CORE) in Pitkin County, and Office for Resource Efficiency (ORE) in Gunnison County. Utility partners contributed $166,600 to support Home Energy Assessments for their customers. Program staff opened Energy Resource Centers, engaged a network of qualified contractors, developed a work-flow, an enrollment website, a loan program, and a data management system to track results.

  6. Electrographic Correlates of Plateau Waves in Patients With Leptomeningeal Metastases. (United States)

    Gold, C A; Odom, N; Srinivasan, S; Schaff, L; Haggiagi, A; Odia, Yazmín


    We describe video electroencephalography (video-EEG) correlates of transient neurological attacks due to plateau waves-paroxysmal elevations in intracranial pressure-in patients with leptomeningeal metastases. We identified 3 patients with leptomeningeal metastases, intracranial hypertension, and transient neurological attacks captured on video-EEG without evidence of seizures or epileptiform activity. We identified all clinical events on video and reviewed the corresponding EEG data for evidence of abnormalities. All 3 patients had mild to moderate slowing and 2 had frontal intermittent rhythmic delta activity during background EEG recording. There were 33 clinical events recorded and stereotyped for each patient. All 33 events were associated with an increase in delta range slowing of ≥30% compared to the background. This abnormality started ≤2 minutes before the onset of clinical symptoms and persisted for minutes after clinical resolution. This study is the first to carefully describe the electrographic correlates of transient neurological attacks due to plateau waves in patients with leptomeningeal metastasis. Clinical attacks were consistently associated with a possible EEG signature of diffuse delta range slowing. Future studies can validate the sensitivity and specificity of these EEG changes as a prognostic and/or response biomarker in patients with leptomeningeal metastases with or without intracranial hypertension.

  7. Along-strike topographic variation of Qinghai Nanshan and its significance for landscape evolution in the northeastern Tibetan Plateau (United States)

    Su, Qi; Xie, Hong; Yuan, Dao-Yang; Zhang, Hui-Ping


    Cenozoic basins and ranges constitute the high topography of the northeastern Tibetan Plateau which is derived from the Indo-Asian collision. The geomorphological characteristics of the ranges provide direct insight into the uplift processes which are responsible for the patterns of the ranges and the growth of the northeastern Tibetan Plateau. This study analyzed the geomorphological features of Qinghai Nanshan (one of the youngest ranges within the northeastern Tibetan Plateau), including elevation, slope distribution and the channel steepness index. Topographic analysis revealed that elevations and slopes in western and central portions of Qinghai Nanshan were higher than those in the eastern portion, whereas the channel steepness index revealed a step-growth mode from west to east. Considering the topographic features, the lateral gradient of precipitation (increasing from west to east) and the lithology distribution, it is concluded that the geomorphological features of Qinghai Nanshan are influenced mainly by tectonic activities and reflect the growth pattern and/or the tectonic setting of the range. Comparing with previous studies, it is shown that the formation mechanism of Qinghai Nanshan follows a middle-to-sides growth pattern. Furthermore, the degree of inclination of the erosion surface distributed on the northern flank of the range suggests that Qinghai Nanshan is controlled jointly by the listric Qinghai Nanshan thrust fault and the influences from the Elashan and Riyueshan dextral strike slip faults. In addition, the northeastern Tibetan Plateau exhibits an outside-in growth process, which might reflect the northeastward growth of the entire northeastern Tibetan Plateau.

  8. USGS Colorado Water Science Center bookmark (United States)



    The U.S. Geological Survey Colorado Water Science Center conducts its water-resources activities primarily in Colorado in cooperation with more than 125 different entities. These activities include extensive data-collection efforts and studies of streamflow, water quality, and groundwater to address many specific issues of concern to Colorado water-management entities and citizens. The collected data are provided in the National Water Information System, and study results are documented in reports and information served on the Internet.

  9. The Hubble Flow of Plateau Inflation

    NARCIS (Netherlands)

    Coone, Dries; Roest, Diederik; Vennin, Vincent


    In the absence of CMB precision measurements, a Taylor expansion has often been invoked to parametrize the Hubble flow function during inflation. The standard "horizon flow" procedure implicitly relies on this assumption. However, the recent Planck results indicate a strong preference for plateau

  10. Tectonostratigraphic evolution of Falkland (Malvinas) Plateau

    Energy Technology Data Exchange (ETDEWEB)

    Snavely, P.D. III


    The Falkland (a.k.a. Malvinas) Plateau, offshore southern Argentina, came into being as the result of the Late Jurassic-Early Cretaceous breakup of west Gondwanaland and the opening of the South Atlantic. As the trailing edge of the South American plate, this continental salient has periodically interacted with the African, Antarctic, Scotia, and Nazca plates, recording the complex history of Mesozoic and Cenozoic plate reorganization in the Southern Hemisphere. The pelagic depositional setting of the plateau following its separation from Africa has resulted in the accumulation of a relatively thin post-rift sedimentary section. This has allowed not only local penetration of the lower Mesozoic section by borehole but also seismic resolution of the pre- and syn-rift strata beyond that generally obtainable from the thick marine basins of the Argentine or South African continental shelves. These subsurface data have been used to compile a relatively complete depositional and tectonic history for the Falkland Plateau which may be applied, by analogy, to sedimentary basins of similar age along the circum-Gondwana perimeter. Three principal tectonic events appear to have influenced the type and orientation of structures and the distribution of stratal patterns presently observed on the Falkland Plateau. These are (1) a Permo-Triassic compressional event (Cape orogeny) that resulted in the formation of a fold-belt running from northwest Argentina through South Africa and across the Falkland Plateau to Antarctica, (2) the two-stage breakup of the Gondwana supercontinent from Late Triassic to Early Cretaceous time, and (3) the Tertiary opening of the Drake Passage and the formation of the Scotia Sea.

  11. Genetic diversity and sex-bias dispersal of plateau pika in Tibetan plateau. (United States)

    Zhang, Liangzhi; Qu, Jiapeng; Li, Kexin; Li, Wenjing; Yang, Min; Zhang, Yanming


    Dispersal is an important aspect in organism's life history which could influence the rate and outcome of evolution of organism. Plateau pika is the keystone species in community of grasslands in Tibetan Plateau. In this study, we combine genetic and field data to character the population genetic pattern and dispersal dynamics in plateau pika (Ochotona curzoniae). Totally, 1,352 individual samples were collected, and 10 microsatellite loci were analyzed. Results revealed that plateau pika possessed high genetic diversity and inbreeding coefficient in a fine-scale population. Dispersal distance is short and restricted in about 20 m. An effective sex-biased dispersal strategy is employed by plateau pika: males disperse in breeding period for mating while females do it after reproduction for offspring and resource. Inbreeding avoiding was shown as the common driving force of dispersal, together with the other two factors, environment and resource. In addition, natal dispersal is female biased. More detailed genetic analyzes are needed to confirm the role of inbreeding avoidance and resource competition as ultimate cause of dispersal patterns in plateau pika.

  12. The Altiplano-Puna Plateau as an Analog for Mars (United States)

    de Silva, S. L.; Byrnes, J. M.; Crown, D. A.; Zimbelman, J. R.; Jimenez, N.; Bills, B. G.


    The Altiplano-Puna Plateau of the Central Andes of Bolivia has experienced a climatic and geologic evolution that has resulted in an enticing array of potential Martian analog geologic environments and features. Elevated ~3 ? 4km above the adjacent Atacama desert, the Altiplano-Puna is the highest plateau in the world associated with extensive volcanism; it is second only to Tibet in height and extent. The high elevation adds extreme cold, wind, and lower atmospheric pressure to a hyper-arid climate making this region a compelling analog environment for Mars. The plateau is dominated by the Altiplano basin, which developed as a major intermontane basin since at least 25Ma. This is flanked by major volcanic provinces to the east and south. To the south is the Altiplano-Puna Volcanic Complex (APVC) where regionally extensive ignimbrite sheets and associated eruptive centers are amongst the largest known volcanic features in the world. The region has proven to be an excellent natural laboratory for remote sensing and field-based studies of volcanism. The extreme cold, wind, and the wide diurnal temperature range, results in geomorphic expressions dominated by physical weathering and aeolian erosion. These factors make this region one of the premier analog environments for Martian features like Amazonis Planitia, and Hadriaca, Alba, and Tyrrhena paterae, as well as the enigmatic Medusa Fossae Formation (MFF) materials. Large ignimbrite shields, are prominent features of volcanic geology of the plateau and are the subject of an ongoing terrestrial analog study for the MFF. The Altiplano basin preserves a long Pleistocene lake history recorded in a well-preserved lake shore geomorphology consisting of both erosional and depositional features. These features are easily identified and studied in the field and on remotely sensed images and may lend valuable insight into the debate over putative paleoshorelines in the northern plains of Mars. Throughout the basin are several

  13. Colorado River Mile System, Tenths of Miles (United States)

    U.S. Geological Survey, Department of the Interior — This coverage contains points representing tenth of miles in the GCMRC river mile system. The points fall along the centerline of the Colorado River from Glen Canyon...

  14. Notes and comments on Colorado Refuges (United States)

    US Fish and Wildlife Service, Department of the Interior — This report is a summary of actual management actions, and plant community responses on Colorado refuges during 1992. It is part of the moist-soil expert system...

  15. BLM Colorado Oil and Gas Leases (Dissolved) (United States)

    Department of the Interior — KMZ File Format –This data is one feature type that is a part of a set consisting of six shapefiles pertaining to energy development and production in Colorado. The...

  16. BLM Colorado Oil and Gas Leases (Dissolved) (United States)

    Department of the Interior — Shapefile Format –This data is one feature type that is a part of a set consisting of six shapefiles pertaining to energy development and production in Colorado. The...

  17. BLM Colorado Oil & Gas Geophysical Permits (Dissolved) (United States)

    Department of the Interior — Shapefile Format –This data is one feature type that is a part of a set consisting of six shapefiles pertaining to energy development and production in Colorado. The...

  18. Approaches to local climate action in Colorado (United States)

    Huang, Y. D.


    Though climate change is a global problem, the impacts are felt on the local scale; it follows that the solutions must come at the local level. Fortunately, many cities and municipalities are implementing climate mitigation (or climate action) policies and programs. However, they face many procedural and institutional barriers to their efforts, such of lack of expertise or data, limited human and financial resources, and lack of community engagement (Krause 2011). To address the first obstacle, thirteen in-depth case studies were done of successful model practices ("best practices") of climate action programs carried out by various cities, counties, and organizations in Colorado, and one outside Colorado, and developed into "how-to guides" for other municipalities to use. Research was conducted by reading documents (e.g. annual reports, community guides, city websites), email correspondence with program managers and city officials, and via phone interviews. The information gathered was then compiled into a series of reports containing a narrative description of the initiative; an overview of the plan elements (target audience and goals); implementation strategies and any indicators of success to date (e.g. GHG emissions reductions, cost savings); and the adoption or approval process, as well as community engagement efforts and marketing or messaging strategies. The types of programs covered were energy action plans, energy efficiency programs, renewable energy programs, and transportation and land use programs. Between the thirteen case studies, there was a range of approaches to implementing local climate action programs, examined along two dimensions: focus on climate change (whether it was direct/explicit or indirect/implicit) and extent of government authority. This benchmarking exercise affirmed the conventional wisdom propounded by Pitt (2010), that peer pressure (that is, the presence of neighboring jurisdictions with climate initiatives), the level of

  19. Outcome evaluation of staged treatment for bicondylar tibial plateau fractures. (United States)

    Giordano, Vincenzo; do Amaral, Ney Pecegueiro; Koch, Hilton A; E Albuquerque, Rodrigo Pires; de Souza, Felipe Serrão; Dos Santos Neto, José Félix


    The universal accepted strategy for treating high-energy tibial plateau fractures remains a topic of ongoing debate. The challenge for the practicing orthopaedic trauma surgeon is to provide anatomical articular fracture reduction, with successfully managing the complex soft-tissue injury that is commonly present at patient admission. The primary aim of the actual study was to evaluate the results of a staged protocol for the treatment of high-energy bicondylar tibial plateau fractures. The secondary aim was to describe the technique used for the definitive fixation of this complex fracture pattern. Thirty patients with unstable high-energy closed bicondylar tibial plateau fractures (17 Schatzker V and 13 Schatzker VI) were managed. There were 24 men (80%) and six women (20%). All of them were skeletally mature with their age ranging from 19 to 67 years (mean of 33.1±3.4 years). Treatment involved a two-stage procedure with appropriate emergency care, preoperative planning, and definitive fixation. Initial treatment, named 'damage control on complex articular fracture elements', consisted on temporary bridging external fixation. Definitive treatment was delayed in a mean of 10 days (ranging from seven to 13 days) and was performed when the soft-tissue conditioning demonstrated either complete or almost complete remission of the inflammatory reaction due to the 'first hit'. Conventional implants were used in the 30 patients. All patients were evaluated clinically and radiographically. Twenty-six (86.7%) patients had a moderate level of activity, three (10%) patients had a very light level of activity, and one (3.3%) patient was unable to have any kind of work activity and is currently supported by the Brazilian Welfare. Using the visual analog scale mean pain score was 30 (ranging from 10 to 60); even the patient with the workers' compensation had no severe pain. All patients except three have no difficulty with stairs, giving way, locking, swelling, and squatting

  20. Colorado Better Buildings Project. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Strife, Susie [Boulder County, Boulder, CO (United States); Yancey, Lea [Boulder County, Boulder, CO (United States)


    advisors and across local governments and local service vendors. A portion of the BetterBuildings grant went to the Metro Mayors Caucus (MMC) who worked in partnership with the Denver Regional Council of Governments (DRCOG) to conduct a series of 10 energy efficiency workshops for local government officials and other interested parties. The workshops helped showcase lessons learned on energy efficiency and helped guide other local governments in the establishment of similar programs. The workshops covered a wide range of energy efficiency and renewable energy topics such as clean energy finance, social mobilization and communications, specific case studies of Colorado towns, energy efficiency codes, net zero buildings and solar power. Since the programs launched in January 2011, these communities have collectively spurred economic investments in energy efficiency, achieved greater than 5:1 leveraging of grant funds, saved energy and reduced greenhouse gas emissions, provided trainings for a robust local energy contractor network, and proved out viable and replicable program models that local utilities and other communities are adopting, with long lasting market transformation.

  1. Hydrogeology of the Markagunt Plateau, Southwestern Utah (United States)

    Spangler, Lawrence E.


    The Markagunt Plateau, in southwestern Utah, lies at an altitude of about 9,500 feet and is capped primarily by Quaternary-age basalt that overlies Eocene-age freshwater limestone of the Claron Formation. Over large parts of the Markagunt Plateau, dissolution of the Claron limestone and subsequent collapse of the overlying basalt have produced a terrain characterized by sinkholes as much as 1,000 feet across and 100 feet deep. Numerous large springs discharge from the basalt and underlying limestone on the plateau, including Mammoth Spring, one of the largest springs in Utah, with a discharge that can exceed 300 cubic feet per second. Discharge from Mammoth Spring is from the Claron Formation; however, recharge to the spring largely takes place by both focused and diffuse infiltration through the basalt that caps the limestone. Results of dye tracing to Mammoth Spring indicate that recharge originates largely southwest of the spring outside of the Mammoth Creek watershed, as well as from losing reaches along Mammoth Creek. Maximum groundwater travel time to the spring from dye-tracer tests during the snowmelt runoff period was about 1 week. Specific conductance and water temperature data from the spring show an inverse relation to discharge during snowmelt runoff and rainfall events, also indicating short groundwater residence times. Results of major-ion analyses for samples collected from Mammoth and other springs on the plateau indicate calcium-bicarbonate type water containing low (less than 200 mg/L) dissolved-solids concentrations. Investigations in the Navajo Lake area along the southern margin of the plateau have shown that water losing to sinkholes bifurcates and discharges to both Cascade and Duck Creek Springs, which subsequently flow into the Virgin and Sevier River basins, respectively. Groundwater travel times to these springs, on the basis of dye tracing, were about 8.5 and 53 hours, respectively. Similarly, groundwater travel time from Duck Creek

  2. Unintentional Pediatric Exposures to Marijuana in Colorado, 2009-2015. (United States)

    Wang, George Sam; Le Lait, Marie-Claire; Deakyne, Sara J; Bronstein, Alvin C; Bajaj, Lalit; Roosevelt, Genie


    As of 2015, almost half of US states allow medical marijuana, and 4 states allow recreational marijuana. To our knowledge, the effect of recreational marijuana on the pediatric population has not been evaluated. To compare the incidence of pediatric marijuana exposures evaluated at a children's hospital and regional poison center (RPC) in Colorado before and after recreational marijuana legalization and to compare population rate trends of RPC cases for marijuana exposures with the rest of the United States. Retrospective cohort study of hospital admissions and RPC cases between January 1, 2009, and December 31, 2015, at Children's Hospital Colorado, Aurora, a tertiary care children's hospital. Participants included patients 0 to 9 years of age evaluated at the hospital's emergency department, urgent care centers, or inpatient unit and RPC cases from Colorado for single-substance marijuana exposures. Marijuana. Marijuana exposure visits and RPC cases, marijuana source and type, clinical effects, scenarios, disposition, and length of stay. Eighty-one patients were evaluated at the children's hospital, and Colorado's RPC received 163 marijuana exposure cases between January 1, 2009, and December 31, 2015, for children younger than 10 years of age. The median age of children's hospital visits was 2.4 years (IQR, 1.4-3.4); 25 were girls (40%) . The median age of RPC marijuana exposures was 2 years (IQR, 1.3-4.0), and 85 patients were girls (52%). The mean rate of marijuana-related visits to the children's hospital increased from 1.2 per 100 000 population 2 years prior to legalization to 2.3 per 100,000 population 2 years after legalization (P = .02). Known marijuana products involved in the exposure included 30 infused edibles (48%). Median length of stay was 11 hours (interquartile range [IQR], 6-19) and 26 hours (IQR, 19-38) for admitted patients. Annual RPC pediatric marijuana cases increased more than 5-fold from 2009 (9) to 2015 (47). Colorado had an

  3. Genetic variation and phylogenetic relationships of the ectomycorrhizal Floccularia luteovirens on the Qinghai-Tibet Plateau. (United States)

    Xing, Rui; Gao, Qing-Bo; Zhang, Fa-Qi; Fu, Peng-Cheng; Wang, Jiu-Li; Yan, Hui-Ying; Chen, Shi-Long


    Floccularia luteovirens, as an ectomycorrhizal fungus, is widely distributed in the Qinghai-Tibet Plateau. As an edible fungus, it is famous for its unique flavor. Former studies mainly focus on the chemical composition and genetic structure of this species. However, the phylogenetic relationship between genotypes remains unknown. In this study, the genetic variation and phylogenetic relationship between the genotypes of F. luteovirens in Qinghai-Tibet Plateau was estimated through the analysis on two protein-coding genes (rpb1 and ef-1α) from 398 individuals collected from 24 wild populations. The sample covered the entire range of this species during all the growth seasons from 2011 to 2015. 13 genotypes were detected and moderate genetic diversity was revealed. Based on the results of network analysis, the maximum likelihood (ML), maximum parsimony (MP), and Bayesian inference (BI) analyses, the genotypes H-1, H-4, H-6, H-8, H-10, and H-11 were grouped into one clade. Additionally, a relatively higher genotype diversity (average h value is 0.722) and unique genotypes in the northeast edge of Qinghai- Tibet plateau have been found, combined with the results of mismatch analysis and neutrality tests indicated that Southeast Qinghai-Tibet plateau was a refuge for F. luteovirens during the historical geological or climatic events (uplifting of the Qinghai-Tibet Plateau or Last Glacial Maximum). Furthermore, the present distribution of the species on the Qinghai-Tibet plateau has resulted from the recent population expansion. Our findings provide a foundation for the future study of the evolutionary history and the speciation of this species.

  4. Debris flow occurrence and sediment persistence, Upper Colorado River Valley, CO (United States)

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


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

  5. Debris Flow Occurrence and Sediment Persistence, Upper Colorado River Valley, CO. (United States)

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


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

  6. Climate processes on the antarctic plateau

    Energy Technology Data Exchange (ETDEWEB)

    Warren, S.G.; Harder, S.L.; Brandt, R.E. (Univ. of Washington, Seattle, WA (United States))


    Experiments on the climate processes on the antarctic plateau, begun at the South Pole in the 1990-91 summer season and carried out during the full year December 1991 to December 1992 are summarized in the article. Experiments discussed include the following: Effect of sastrugi on bidirectional reflectance of snow; temperatures in the near-surface snow; atmospheric longwave radiation spectrum; Air snow exchange processes; sampling of falling and surface snow; air sampling; blowing and drifting snow. 8 refs.

  7. Impact of the model resolution on the simulation of elevation-dependent warming in the Tibetan Plateau-Himalayas, Greater Alpine Region, and Rocky mountains (United States)

    Palazzi, Elisa; Mortarini, Luca; Terzago, Silvia; von Hardenberg, Jost


    The enhancement of warming rates with elevation, the so-called elevation-dependent warming (EDW), is one of the clearest regional expressions of global warming. Real sentinels of climate and environmental changes, mountains have experienced more rapid and intense warming rates in the recent decades, leading to serious impacts on mountain ecosystems and downstream societies, some of which are already occurring. In this study we use the historical and scenario simulations of one state-of-the-art global climate model, the EC-Earth GCM, run at five different spatial resolutions, from ˜125 km to ˜16 km, to explore the existence, characteristics and driving mechanisms of EDW in three different mountain regions of the world - the Colorado Rocky Mountains, the Greater Alpine Region and the Tibetan Plateau-Himalayas. The aim of this study is twofold: to investigate the impact (if any) of increasing model resolution on the representation of EDW and to highlight possible differences in this phenomenon and its driving mechanisms in different mountain regions of the northern hemisphere. Preliminary results indicate that autumn (September to November) is the only season in which EDW is simulated by the model in both the maximum and the minimum temperature, in all three regions and across all model resolutions. Regional differences emerge in the other seasons: for example, the Tibetan Plateau-Himalayas is the only area in which EDW is detected in winter. As for the analysis of EDW drivers, we identify albedo and downward longwave radiation as being the most important variables for EDW, in all three areas considered and in all seasons. Further these results are robust to changes in model resolution, even though a clearer signal is associated with finer resolutions. We finally use the highest resolution EC-Earth simulations available (˜16 km) to identify what areas, within the three considered mountain ranges, are expected to undergo a significant reduction of snow or ice cover

  8. The Influence of Arctic Oscillation and ENSO on Snow Cover Days on Qinghai-Tibetan Plateau (United States)

    Xiao, Tiangui; Wang, Chao; Jia, Lha; Du, Jun; Chen, Qianwen


    Based on Qinghai-Tibetan Plateau Snow data, index of NINO sea temperature anomaly, and AO index. The influence from Arctic Oscillation and ENSO to days of snow cover in plateau was studied, and the main conclusions are as follows: 1. Both AO index and NINO index are positively correlated with days of snow cover in plateau, and the correlation coefficients are 0.59, 0.41 respectively (both passed the significant test at0.01 level). There is a positively correlation between NINO index and western plateau, and passed the significant test. But to the eastern plateau, it is uncorrelated. 2. The average of snow cover days in whole plateau is 8.79 d, during 1964-2013. The maximum value of snow cover days is 41.38 d in Nielamu, and the minimum lesser than 1 d in Haiyan. When the AO at positive anomaly, the snow cover days is higher, and the maximum value up to 48.8d at Jiani. At in negative anomaly of AO, the snow cover day is lower. There is a positively correlation between AO and snow cover days. 3. When the AO at positive anomaly with El Nino, the maximum value of snow cover days up to 54.25 d. Influence of AO and El Nino, the snow cover days is higher. When the AO at positive anomaly with La Nina, the maximum value of snow cover days is 46.3 d, and it is lower than the maximum value which is under AO at positive anomaly period. When the AO at negative anomaly whit El Nino, the value range of snow cover days is 0.007-42.86 d. Due to the Influence of El Nino, the value snow cover days is higher, but with smaller region. When the AO at negative anomaly whit La Nina, the snow cover days is lower in whole plateau. the snow cover days was directly affected by AO and ENSO, and the first is more effective than the latter. Key words: AO; ENSO; Qinghai-Tibetan Plateau; snow cover days Acknowledgements This study was supported by National Natural Science Foundation of China Fund Project (91337215, 41575066), National Key Basic Research Program (2013CB733206), Special Fund for

  9. Geologic map of the Frisco quadrangle, Summit County, Colorado (United States)

    Kellogg, Karl S.; Bartos, Paul J.; Williams, Cindy L.


    New 1:24,000-scale geologic mapping along the Interstate-70 urban corridor in western Colorado, in support of the USGS Central Region State/USGS Cooperative Geologic Mapping Project, is contributing to a more complete understanding of the stratigraphy, structure, tectonic evolution, and hazard potential of this rapidly developing region. The 1:24,000-scale Frisco quadrangle is near the headwaters of the Blue River and straddles features of the Blue River graben (Kellogg, K.S., 1999, Neogene basins of the northern Rio Grande rift?partitioning and asymmetry inherited from Laramide and older uplifts: Tectonophysics, v. 305, p. 141-152.), part of the northernmost reaches of the Rio Grande rift, a major late Oligocene to recent zone of extension that extends from Colorado to Mexico. The Williams Range thrust fault, the western structural margin of the Colorado Front Range, cuts the northeastern corner of the quadrangle. The oldest rocks in the quadrangle underlie the Tenmile Range and include biotite-sillimanite schist and gneiss, amphibolite, and migmatite that are intruded by granite inferred to be part of the 1,667-1,750 Ma Routt Plutonic Suite (Tweto, Ogden, 1987, Rock units of the Precambrian- basement in Colorado: U.S. Geological Survey Professional Paper 1321-A, 54 p.). The oldest sedimentary unit is the Pennsylvanian Maroon Formation, a sequence of red sandstone, conglomerate, and interbedded shale. The thickest sequence of sedimentary rocks is Cretaceous in age and includes at least 500 m of the Upper Cretaceous Pierre Shale. The sedimentary rocks are intruded by sills and dikes of dacite porphyry sills of Swan Mountain, dated at 44 Ma (Marvin, R.F., Mehnert, H.H., Naeser, C.W., and Zartman, R.E., 1989, U.S. Geological Survey radiometric ages, compilation ?C??Part five?Colorado, Montana, Utah, and Wyoming: Isochron/West, no. 53, p. 14-19. Simmons, E.C., and Hedge, C.E., 1978, Minor-element and Sr-isotope geochemistry of Tertiary stocks, Colorado mineral belt

  10. Ecological Integrity Assessment for Colorado Wetlands, Field Manual (United States)

    US Fish and Wildlife Service, Department of the Interior — A quick reviewed survey protocol framework developed by the Colorado Natural Heritage program on performing an Ecological Integrity Assessment (EIA) for Colorado...

  11. Modeling of Dust Levels Associated with Potential Utility-Scale Solar Development in the San Luis Valley-Taos Plateau Study Area

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Y. -S. [Argonne National Lab. (ANL), Argonne, IL (United States); Kotamarthi, R. [Argonne National Lab. (ANL), Argonne, IL (United States); Hartmann, H. M. [Argonne National Lab. (ANL), Argonne, IL (United States); Patton, T. [Argonne National Lab. (ANL), Argonne, IL (United States); Finster, M. [Argonne National Lab. (ANL), Argonne, IL (United States)


    The San Luis Valley (SLV)–Taos Plateau study area in south-central Colorado and north-central New Mexico is a large alpine valley surrounded by mountains with an area of approximately 6,263,000 acres (25,345 km2) (Figure ES.1-1). This area receives ample sunshine throughout the year, making it an ideal location for solar energy generation, and there are currently five photovoltaic facilities operating on private lands in the SLV, ranging in capacity from 1 to 30 megawatt (MW). In 2012 the Bureau of Land Management (BLM) launched its Solar Energy Program, which included the identification of four solar energy zones (SEZs) in the SLV totaling 16,308 acres (66 km2), as well as over 50,000 (202 km2) acres of other BLM-administered lands potentially available for application for solar development. The SEZ areas, named Antonito Southeast, De Tilla Gulch, Fourmile East, and Los Mogotes East, were defined by the BLM as areas well-suited for utility-scale (i.e., larger than 20 MW) production of solar energy where solar energy development would be prioritized (BLM 2012). Nonetheless, it was recognized that solar development in the SEZs would result in some unavoidable adverse impacts, and so the BLM initiated a solar regional mitigation strategy (SRMS) study for three of the SEZs (BLM and Argonne 2016). The SRMS is designed to identify residual impacts of solar development in the SEZs (that is, those that cannot be avoided or minimized onsite), identify those residual impacts that warrant compensatory mitigation when considering the regional status and trends of the resources, identify appropriate regional compensatory mitigation locations and actions to address those residual impacts, and recommend appropriate fees to implement those compensatory mitigation measures.

  12. Treatment of complex tibial plateau fractures using Ilizarov technique. (United States)

    Lalić, Ivica; Daraboš, Nikica; Stanković, Milan; Gojković, Zoran; Obradović, Mirko; Marić, Dušan


    Complex tibial plateau fractures are most commonly caused by high-energy trauma and they are often associated with severe soft tissue injuries that can frequently result in severe complications. Ilizarov external circular fixation is an ideal method of treatment for high- energy fractures of the tibial plateau when extensive soft tissue dissection and internal fixation are contraindicated. Our research included 50 consecutive patients and clinical features of the patients were evaluated during the follow up period using the following instruments: Gustillo-Anderson, Sc- hatzker and Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/ OTA) classification methods. Bony results were evaluated using the Association of the Study and Application of the Method ofIlizarov (ASAMI) protocol. The mean functional recovery scores were obtained by the modified functional evaluation system of Karlstrom-Olerud. All fractures healed successfully. Circular fixators could be removed without anesthesia for type IV fractures at 16 weeks (range 12-21) and for type V-VI at 18 weeks (range 15-26) after the operation. According to ASA- MI bone results, there were 39 (78%) excellent, 7 (14%) good, 3 (6%) fair results and 1 (2%) poor result. Analysis of data obtained by the Karlstrom-Olerud functional evaluation system in this study yielded a mean value of 24.7 after six months, which implies recovery. Functional recovery at 12 months after surgery revealed satisfactory recovery with a mean value of 27.7, whereas the mean sco- re of 29.8 recorded at the last evaluation suggested good functional status. The treatment of patients with open and closed multiple intra-articular fractures of proximal tibia applying Ilizarov apparatus showed good functional outcome, which had positive impact on our patients' quality of life.

  13. Chemical erosion and hydrologic budget for the Susure karst plateau

    Directory of Open Access Journals (Sweden)

    Nikić Zoran


    Full Text Available The karst plateau of Susure, about 4.5 km2 in surface area, is situated on the Jadovnik eastern offset, western Serbia. The plateau is a morphologic unit higher 15 m to 30 m than the surrounding terrain. The unit consists of crushed and karstified Middle Triassic limestones. Numerous hydrogeological and geomorphologic features of the plateau are attractive for visitors in this economically underdeveloped country. Rocks building up the surrounding terrain are largely peridotites. Surface streams flow neither into nor off the plateau. Atmospheric precipitations discharge to evapotanspiration and filtration underground. More than eighteen constant springs at the limestone/peridotite tectonic contact drain fracture aquifers on the karst plateau border. Measured precipitations and springflows were the input and output data for accounting water budget of an aquifer of Middle Triassic limestones in the Susure plateau.

  14. Assessing Orographic Variability in Glacial Thickness Changes at the Tibetan Plateau Using ICESat Laser Altimetry

    Directory of Open Access Journals (Sweden)

    Vu Hien Phan


    Full Text Available Monitoring glacier changes is essential for estimating the water mass balance of the Tibetan Plateau. In this study, we exploit ICESat laser altimetry data in combination with the SRTM DEM and the GLIMS glacier mask to estimate trends in change in glacial thickness between 2003 and 2009 on the whole Tibetan Plateau. Considering acquisition conditions of ICESat measurements and terrain surface characteristics, annual glacier elevation trends were estimated for 15 different settings with respect to terrain slope and roughness. In the end, we only included ICESat elevations acquired over terrain with a slope below 20° and a roughness at the footprint scale below 15 m. With this setting, 90 glaciated areas could be distinguished. The results show that most of observed glaciated areas on the Tibetan Plateau are thinning, except for some glaciers in the northwest. In general, glacier elevations on the whole Tibetan Plateau decreased at an average rate of -0.17±  0.47 m per year (m a-1 between 2003 and 2009, taking together glaciers of any size, distribution, and location of the observed glaciated area. Both rate and rate error estimates are obtained by accumulating results from individual regions using least squares techniques. Our results notably show that trends in glacier thickness change indeed strongly depend on the relative position in a mountain range.

  15. Seismic imaging of a mid-lithospheric discontinuity beneath Ontong Java Plateau (United States)

    Tharimena, Saikiran; Rychert, Catherine A.; Harmon, Nicholas


    Ontong Java Plateau (OJP) is a huge, completely submerged volcanic edifice that is hypothesized to have formed during large plume melting events ∼90 and 120 My ago. It is currently resisting subduction into the North Solomon trench. The size and buoyancy of the plateau along with its history of plume melting and current interaction with a subduction zone are all similar to the characteristics and hypothesized mechanisms of continent formation. However, the plateau is remote, and enigmatic, and its proto-continent potential is debated. We use SS precursors to image seismic discontinuity structure beneath Ontong Java Plateau. We image a velocity increase with depth at 28 ± 4 km consistent with the Moho. In addition, we image velocity decreases at 80 ± 5 km and 282 ± 7 km depth. Discontinuities at 60-100 km depth are frequently observed both beneath the oceans and the continents. However, the discontinuity at 282 km is anomalous in comparison to surrounding oceanic regions; in the context of previous results it may suggest a thick viscous root beneath OJP. If such a root exists, then the discontinuity at 80 km bears some similarity to the mid-lithospheric discontinuities (MLDs) observed beneath continents. One possibility is that plume melting events, similar to that which formed OJP, may cause discontinuities in the MLD depth range. Plume-plate interaction could be a mechanism for MLD formation in some continents in the Archean prior to the onset of subduction.

  16. Hydrogeology - MO 2014 Thermoclines Springfield Plateau Aquifer (SHP) (United States)

    NSGIC State | GIS Inventory — Springfield Plateau aquifer thermo cline correlates the temperature data throughout the state in the upper Mississippian Subsystem, from the Ste. Genevieve Limestone...

  17. Desirable forest structures for a restored Front Range (United States)

    Yvette L. Dickinson; Rob Addington; Greg Aplet; Mike Babler; Mike Battaglia; Peter Brown; Tony Cheng; Casey Cooley; Dick Edwards; Jonas Feinstein; Paula Fornwalt; Hal Gibbs; Megan Matonis; Kristen Pelz; Claudia Regan


    As part of the federal Collaborative Forest Landscape Restoration Program administered by the US Forest Service, the Colorado Front Range Collaborative Forest Landscape Restoration Project (FR-CFLRP, a collaborative effort of the Front Range Roundtable1 and the US Forest Service) is required to define desired conditions for lower montane ponderosa pine (Pinus ponderosa...

  18. Observational facts of sustained departure plateau vortexes (United States)

    Yu, Shuhua; Gao, Wenliang; Peng, Jun; Xiao, Yuhua


    By using the twice-daily atmospheric observation data from 1998 to 2012, station rainfall data, Tropical Rainfall Measure Mission (TRMM) data, as well as the plateau vortex and shear line year book, characteristics of the sustained departure plateau vortexes (SDPVs) are analyzed. Some new useful observational facts and understanding are obtained about the SDPV activities. The following results are obtained. (1) The active period of SDPVs is from June to August, most in July, unlike that of the unsustained departure plateau vortexes (UDPVs), which have same occurrence frequencies in the three summer months. (2) The SDPVs, generated mainly in the Qumalai neighborhood and situated in a sheared surrounding, move eastward or northeastward, while the UDPVs are mainly led by the upper-level trough, and move eastward or southeastward. (3) The SDPVs influence wide areas of China, even far to the Korean Peninsula, Japan, and Vietnam. (4) The SDPVs change their intensities and properties on the way to the east. Most of them become stronger and produce downpour or sustained regional rainstorms to the south of Yellow River. (5) The longer the SDPV sustains, the more baroclinity it has. (6) When an SDPV moves into the sea, its central pressure descends and rainfall increases in all probability. (7) An SDPV might spin over the bend of the Yellow River when there exists a tropical cyclone in the East China Sea. It could also move oppositely to a landed tropical low pressure originated from the sea to the east of Taiwan or from the South China Sea.

  19. Colorado's clean energy choices

    Energy Technology Data Exchange (ETDEWEB)

    Strawn, N.; Jones, J.


    The daily choices made as consumers affect the environment and the economy. Based on the state of today's technology and economics, Colorado consumers can include energy efficiency and renewable energy into many aspects of their lives. These choices include where they obtain electricity, how they use energy at home, and how they transport themselves from one place to another. In addition to outlining how they can use clean energy, Colorado's Clean Energy Choices gives consumers contacts and links to Web sites for where to get more information.

  20. Middle Pleistocene infill of Tibetan Plateau margin rivers, Zanskar, India (United States)

    Munack, Henry; Blöthe, Jan; Korup, Oliver; Fülöp, Réka-Hajnalka; Codilean, Alexandru T.; Fink, David


    The Indus, one of Asia's premier rivers, drains the NW Himalaya and the Transhimalayan ranges that fringe the western Tibetan Plateau margin. There, upstream of the western Himalayan syntaxis, river valleys alternate between deeply incised bedrock gorges and broad alluviated reaches, while average denudation rates decrease by an order of magnitude towards the Tibetan Plateau margin to rates of ~10 mm ka-1. Vast fill terrace staircases, the highest of them located up to 400 m above current river level, and intercalated lake sediments indicate alternating phases of incision and aggradation within the region, underlining the high landform preservation potential in the rain shadow of the High Himalaya. However, despite a broad interest in a better understanding of mechanisms that modulate plateau erosion, age constraints on the generation of these impressive features are sparse, though indicate mainly Pleistocene formation ages. We present new age constraints from the More Plains section in the headwaters of the Zanskar River, a major tributary to the upper Indus. The vast sedimentary successions of the More Plains originally belonged to a former endorheic basin that has been tapped by the Zanskar River, today revealing exposures of >250 m of sedimentary fill that continues to smother a previously dissected alpine headwater landscape. We combine 10Be surface exposure dating and catchment-averaged denudation rates, morphometric analysis and field observation to constrain the late Quaternary history of this section. Analysis of a 10Be depth profile on top of the More Plains, together with the dating of nearby amalgamated surface samples, indicate a surface exposure of ~170 +/- 20 ka such that deposition of this valley fill ceased during a Middle Pleistocene cold stage (MIS 6). Using GIS-based algorithms we estimate that ~3.6 km3 was removed from this section by fluvial erosion, requiring a specific sediment yield of >130 t km-2 yr-1 averaged over the past 170 ka. This

  1. Traveltime characteristics of Gore Creek and Black Gore Creek, upper Colorado River basin, Colorado (United States)

    Gurdak, Jason J.; Spahr, Norman E.; Szmajter, Richard J.


    In the Rocky Mountains of Colorado, major highways are often constructed in stream valleys. In the event of a vehicular accident involving hazardous materials, the close proximity of highways to the streams increases the risk of contamination entering the streams. Recent population growth has contributed to increased traffic volume along Colorado highways and has resulted in increased movement of hazardous materials, particularly along Interstate 70. Gore Creek and its major tributary, Black Gore Creek, are vulnerable to such contamination from vehicular accidents along Interstate 70. Gore Creek, major tributary of the Eagle River, drains approximately 102 square miles, some of which has recently undergone significant urban development. The headwaters of Gore Creek originate in the Gore Range in the eastern part of the Gore Creek watershed. Gore Creek flows west to the Eagle River. Beginning at the watershed boundary on Vail Pass, southeast of Vail Ski Resort, Interstate 70 parallels Black Gore Creek and then closely follows Gore Creek the entire length of the watershed. Interstate 70 crosses Gore Creek and tributaries 20 times in the watershed. In the event of a vehicular accident involving a contaminant spill into Gore Creek or Black Gore Creek, a stepwise procedure has been developed for water-resource managers to estimate traveltimes of the leading edge and peak concentration of a conservative contaminant. An example calculating estimated traveltimes for a hypothetical contaminant release in Black Gore Creek is provided. Traveltime measurements were made during May and September along Black Gore Creek and Gore Creek from just downstream from the Black Lakes to the confluence with the Eagle River to account for seasonal variability in stream discharge. Fluorometric dye injection of rhodamine WT and downstream dye detection by fluorometry were used to measure traveltime characteristics of Gore Creek and Black Gore Creek. During the May traveltime measurements

  2. Final Evaluation Report for Colorado [City] Bilingual Education Program, Colorado [City] Independent School District, Colorado City, Texas. (United States)

    Simmons, Raymond S.

    The final evaluation report for the Colorado City Bilingual Education Program is presented in this paper. The project was directed to kindergarten children from low-income disadvantaged homes; of 63 participants, 53 were Spanish-speaking children and 10 were monolingual English-speaking children. Project staff consisted of a bilingual teacher, a…

  3. 76 FR 17444 - Notice of Inventory Completion: Colorado Historical Society (History Colorado), Denver, CO (United States)


    ... Ruin had multiple owners, including private citizens and the State of New Mexico. It is not known if... with the human remains should contact Bridget Ambler, Curator of Material Culture, Colorado Historical...

  4. Progenitors of low-luminosity Type II-Plateau supernovae (United States)

    Lisakov, Sergey M.; Dessart, Luc; Hillier, D. John; Waldman, Roni; Livne, Eli


    The progenitors of low-luminosity Type II-Plateau supernovae (SNe II-P) are believed to be red supergiant (RSG) stars, but there is much disparity in the literature concerning their mass at core collapse and therefore on the main sequence. Here, we model the SN radiation arising from the low-energy explosion of RSG stars of 12, 25 and 27 M⊙ on the main sequence and formed through single star evolution. Despite the narrow range in ejecta kinetic energy (2.5-4.2 × 1050 erg) in our model set, the SN observables from our three models are significantly distinct, reflecting the differences in progenitor structure (e.g. surface radius, H-rich envelope mass and He-core mass). Our higher mass RSG stars give rise to Type II SNe that tend to have bluer colours at early times, a shorter photospheric phase, and a faster declining V-band light curve (LC) more typical of Type II-linear SNe, in conflict with the LC plateau observed for low-luminosity SNe II. The complete fallback of the CO core in the low-energy explosions of our high-mass RSG stars prevents the ejection of any 56Ni (nor any core O or Si), in contrast to low-luminosity SNe II-P, which eject at least 0.001 M⊙ of 56Ni. In contrast to observations, Type II SN models from higher mass RSGs tend to show an H α absorption that remains broad at late times (due to a larger velocity at the base of the H-rich envelope). In agreement with the analyses of pre-explosion photometry, we conclude that low-luminosity SNe II-P likely arise from low-mass rather than high-mass RSG stars.

  5. IODP Expedition 324: Ocean Drilling at Shatsky Rise Gives Clues about Oceanic Plateau Formation

    Directory of Open Access Journals (Sweden)

    Jörg Geldmacher


    Full Text Available Integrated Ocean Drilling Program (IODP Expedition 324 cored Shatsky Rise at five sites (U1346–U1350 to study processes of oceanic plateau formation and evolution. Site penetrations ranged from 191.8 m to 324.1 m with coring of 52.6 m to 172.7 m into igneous basement at four of the sites. Average recovery in basement was 38.7%–67.4%. Cored igneous sections consist mainly of variably evolved tholeiiticbasalts emplaced as pillows or massive flows. Massive flows are thickest and make up the largest percentage of section on the largest and oldest volcano, late Jurassic age Tamu Massif; thus, it may have formed at high effusion rates. Such massive flows are characteristic of flood basalts, and similar flows were cored at Ontong Java Plateau. Indeed, the similarity of igneous sections at Site U1347 with that cored on Ontong Java Plateau implies similar volcanic styles for these two plateaus. On younger, smaller Shatsky Rise volcanoes, pillow flows are common and massive flows thinner andfewer, which might mean volcanism waned with time. Cored sediments from summit sites contain fossils and structures implying shallow water depths or emergence at the time of eruption and normal subsidence since. Summit sites also show pervasive alteration that could be due to high fluid fluxes. A thick section of volcaniclastics cored on Tamu Massif suggests that shallow, explosive submarine volcanism played a significant role in the geologic development of the plateau summit. Expedition 324 results imply that Shatsky Risebegan with massive eruptions forming a huge volcano and that subsequent eruptions waned in intensity, forming volcanoes that are large, but which did not erupt with unusually high effusionrates. Similarities of cored sections on Tamu Massif with those ofOntong Java Plateau indicate that these oceanic plateaus formed insimilar fashion.

  6. Surgical Management of Tibial Plateau Fractures With 3.5 mm Simple Plates. (United States)

    Bagherifard, Abolfazl; Jabalameli, Mahmoud; Hadi, Hosseinali; Rahbar, Mohammad; Minator Sajjadi, Mohammadreza; Jahansouz, Ali; Karimi Heris, Hossein


    Tibial plateau fractures can be successfully fixed utilizing 3.5 mm locking plates. However, there are some disadvantages to using these plates. In the current prospective study, we investigated the outcome of treating different types of tibial plateau fractures with 3.5 mm simple plates which, to our knowledge, has not been evaluated in previous studies. Between 2011 and 2013, 32 patients aged 40 ± 0.2 years underwent open reduction and internal fixation for tibial plateau fractures with 3.5 mm simple plates. The patients were followed for 16.14 ± 2.1 months. At each patient's final visit, the articular surface depression, medial proximal tibial angle, and slope angle were measured and compared with measurements taken early after the operation. The functional outcomes were measured with the WOMAC and Lysholm knee scores. The mean union time was 13 ± 1.2 weeks. The mean knee range of motion was 116.8° ± 3.3°. The mean WOMAC and Lysholm scores were 83.5 ± 1.8 and 76.8 ± 1.6, respectively. On the early postoperative and final X-rays, 87.5% and 84% of patients, respectively, had acceptable reduction. Medial proximal tibial and slope angles did not change significantly by the last visit. No patient was found to have complications related to the type of plate. In this case series study, the fixation of different types of tibial plateau fractures with 3.5 mm simple non-locking and non-precontoured plates was associated with acceptable clinical, functional, and radiographic outcomes. Based on the advantages and costs of these plates, the authors recommend using 3.5 mm simple plates for different types of tibial plateau fractures.

  7. Colorado State University: A Midscale Market Solar Customer Case Study

    Energy Technology Data Exchange (ETDEWEB)

    Holm, Alison [National Renewable Energy Lab. (NREL), Golden, CO (United States); Chernyakhovskiy, Ilya [National Renewable Energy Lab. (NREL), Golden, CO (United States)


    Despite substantial increases in solar photovoltaic (PV) deployment between 2005 and 2015, a large untapped market for solar PV deployment still exists in midscale market investments by universities. Recent estimates show that if all universities in the United States installed enough solar PV to meet 25% of their annual electricity consumption, this would cumulatively result in just over 16 gigawatts (GW) of additional installed PV capacity. Within this context, midscale market projects - loosely defined as solar PV installations ranging from 100 kilowatts (kW) to 2 megawatts (MW), but more broadly representing installations not captured in the residential or utility-scale sectors - could be an attractive option for universities. This case study focuses on one university solar customer, Colorado State University (CSU), to provide a detailed example of the challenges, solutions, and opportunities associated with university solar power procurement. Between 2009 and 2015, a combined 6,754 kW of both ground-mounted and rooftop solar PV was installed across multiple CSU campuses in Fort Collins, Colorado. This case study highlights CSU's decision-making process, campus engagement strategies, and relationships with state, local, and utility partners, which have culminated in significant on-campus PV deployment.

  8. Technical progress report. [Nuclear Physics Lab. , Univ. of Colorado

    Energy Technology Data Exchange (ETDEWEB)


    This report summarizes the work carried out at the Nuclear Physics Laboratory of the University of Colorado during the period November 1, 1977 to November 1, 1978, under Contract EY-76-C-02-0535.A002 between the University of Colorado and the United States Department of Energy. The research activities of the Laboratory spanned a broad range of interests over the past year. Numerous topics in charged-particle spectroscopy and reaction studies, neutron time-of-flight measurements, and gamma-ray investigations performed at the cyclotron laboratory are covered in this report. In addition, several items in intermediate energy nuclear physics as studied at Los Alamos and Indiana University by members of the Laboratory are reported. The efforts in nuclear theory include studies in nuclear reaction mechanisms and pion scattering as related to the experimental program. Information is also included on apparatus and facility development, cyclotron operation, outside users, publications, and reports. Separate abstracts were written for thirty items in this report having significant amounts of data. (RWR)

  9. The Colorado River in the Grand Canyon. (United States)

    Speece, Susan


    An assessment of the water quality of the Colorado River in the Grand Canyon was made, using the following parameters: dissolved oxygen, water temperature, hydrogen ion concentration, total dissolved solids, turbidity, and ammonium/nitrogen levels. These parameters were used to provide some clue as to the "wellness" and stability of the…

  10. Insects associated with ponderosa pine in Colorado (United States)

    Robert E. Stevens; J. Wayne Brewer; David A. Leatherman


    Ponderosa pine serves as a host for a wide variety of insects. Many of these, including all the particularly destructive ones in Colorado, are discussed in this report. Included are a key to the major insect groups, an annotated list of the major groups, a glossary, and a list of references.

  11. Denver, Colorado: Solar in Action (Brochure)

    Energy Technology Data Exchange (ETDEWEB)


    This brochure provides an overview of the challenges and successes of Denver, Colorado, a 2008 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  12. 78 FR 61441 - Colorado Disaster #CO-00066 (United States)


    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Colorado Disaster CO-00066 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a Notice of the Presidential declaration of a major disaster for Public Assistance Only for the...

  13. Effectiveness of the AHEC Concept in Colorado. (United States)

    Krugman, Richard D.; And Others


    Colorado's area health education program, the SEARCH program, designed to alleviate the maldistribution of health manpower, is described. It recruits new professionals to underserved areas through student/resident rotations and retains those professionals already there by providing accessible continuing education. (Author/MLW)

  14. Besnoitiosis in rodents from Colorado. [Parasitic infestations

    Energy Technology Data Exchange (ETDEWEB)

    Dagle, G E; Winsor, T F; Adee, R R


    Parasitic cysts of Besnoitia jellisoni (coccidia) were found in rodents (Peromyscus maniculatus and Spermophilus tridecemlineatus) trapped in Eastern Colorado. The parasite was associated with a granulomatous inflammatory reaction in the lungs of each rodent and was disseminated in several organs from one Peromyscus. The ultrastructural appearance of the merozoites and the cyst wall formed by the host cell were studied.

  15. KidsCount in Colorado! 1998. (United States)

    Staberg, Christine

    This Kids Count report examines statewide and county trends in the well-being of Colorado's children. The statistical portrait is based on 12 indicators of well-being: (1) infant mortality; (2) low birth weight births; (3) immunizations; (4) child poverty; (5) early prenatal care; (6) child abuse deaths; (7) health insurance; (8) paternity…

  16. KidsCount in Colorado! 1999. (United States)

    Staberg, Christine

    This Kids Count report examines statewide and county trends in the well-being of Colorado's children. The statistical portrait is based on 12 indicators of well-being: (1) infant mortality; (2) low birth weight births; (3) immunizations; (4) child poverty; (5) early prenatal care; (6) child abuse deaths; (7) health insurance; (8) paternity…

  17. Colorado Center for Astrodynamics Research (CCAR) (United States)

    Emery, William


    Viewgraphs on the Colorado Center for Astrodynamics Research (CCAR) are presented. Topics covered include: EOSDIS testbed: an Advanced Very High Resolution Radiometer (AVHRR) data system for snowpack and vegetation studies; satellite data processing software; satellite data analysis activities; mass storage systems; wide area network connections; and remote access.

  18. Feeding stimulants for the colorado beetle

    NARCIS (Netherlands)

    Ritter, F.J.


    Potato leaf extract was fractionated and the fractions obtained were tested for their activity as feeding stimulants for Colorado beetle larvae. Also leaves and leaf extracts of different kinds of plants, as well as a number of known pure compounds and mixtures of them, were tested for this

  19. The quest for peace in Nigeria's Plateau | Odubajo | Africa Insight

    African Journals Online (AJOL)

    Jos, the capital of Plateau State, was the centre of attraction for locals and foreigners alike, as a consequence of its moderate weather, cosmopolitan outlook and tendency for accommodating diversity. For over a decade, however, Jos and various parts of rural Plateau State became theatres of war. The incessant violent ...

  20. Orbital measurements among the ethnic groups of Plateau State ...

    African Journals Online (AJOL)

    The aim of this study is to provide a baseline measurements of these orbital parameters for plateau state indigenes of various ethnic groups and to compare with other studies in Nigeria and other countries. The subjects used in this study were 213 medical students of Plateau state studying at University of Jos. Out of the four ...

  1. Plateau Waves of Intracranial Pressure and Multimodal Brain Monitoring. (United States)

    Dias, Celeste; Maia, Isabel; Cerejo, Antonio; Smielewski, Peter; Paiva, José-Artur; Czosnyka, Marek


    The aim of this study was to describe multimodal brain monitoring characteristics during plateau waves of intracranial pressure (ICP) in patients with head injury, using ICM+ software for continuous recording. Plateau waves consist of an abrupt elevation of ICP above 40 mmHg for 5-20 min. This is a prospective observational study of patients with head injury who were admitted to a neurocritical care unit and who developed plateau waves. We analyzed 59 plateau waves that occurred in 8 of 18 patients (44 %). At the top of plateau waves arterial blood pressure remained almost constant, but cerebral perfusion pressure, cerebral blood flow, brain tissue oxygenation, and cerebral oximetry decreased. After plateau waves, patients with a previously better autoregulation status developed hyperemia, demonstrated by an increase in cerebral blood flow and brain oxygenation. Pressure and oxygen cerebrovascular reactivity indexes (pressure reactivity index and ORxshort) increased significantly during the plateau wave as a sign of disruption of autoregulation. Bedside multimodal brain monitoring is important to characterize increases in ICP and give differential diagnoses of plateau waves, as management of this phenomenon differs from that of regular ICP.

  2. Users Satisfaction with Library and Information Service in Plateau ...

    African Journals Online (AJOL)

    The study investigated Users Satisfaction with Library and Information Service in Plateau State Special Education Institution. Survey research method was adopted for the study and the population of the study consists of staff and students of the special educational institutions in Plateau State. The three selected institutions ...

  3. A stable isotope record of orographic precipitation and continental evaporation across the Central Anatolian Plateau (United States)

    Schemmel, Fabian; Mikes, Tamas; Rojay, Bora; Mulch, Andreas


    The Central Anatolian Plateau (CAP) in central Turkey, much like its larger counterparts in Tibet or the Andes, has a clear influence on regional atmospheric circulations and thus creates a distinct pattern of orographic rainout and rainshadow. Reconstructing these patterns over geological time is a major challenge for understanding the interplay of tectonic and Earth surface processes and their subsequent impact on atmospheric circulation and regional hydrology and ultimately on changes in biodiversity and ecosystems over time. Here we present the first large-scale characterization of hydrogen (δD) and oxygen (δ18O) stable isotopes in precipitation from more than 480 spring and surface water samples from the CAP as well as its northern (Pontic Mts.) and southern (Taurus Mts.) margins. The aim of this study is to quantify the influence of orographic rainout and secondary evaporation on the stable isotopic composition of these meteoric waters and further to establish a robust first-order isotopic template against which continental paleoclimate proxy data can be interpreted. The CAP is bordered by two E-W trending mountain ranges: the Pontic Mountains at the Black Sea coast and the Taurus Mountains at the Mediterranean coast that both serve as major orographic barriers to the transport of moisture, hence developing semi-humid climatic conditions on their windward flanks and arid conditions over the plateau interior. Differences in δD and δ18O values on the northern and southern plateau margins indicate different source regions and are in agreement with observed air parcel trajectories. The orographic rainout on the windward flanks of the Pontic Mountains exhibits isotopic lapse rates of -19 ‰/km for δD and -2.6 ‰/km for δ18O whereas the lapse rates of the Taurus Mountains are slightly higher with -20 ‰/km for δD and -2.9 ‰/km for δ18O across an elevation range of nearly 3000 m. The δD and δ18O values immediate lee of both mountain ranges attain the

  4. Parhelic-like circle from light scattering in Plateau borders

    Energy Technology Data Exchange (ETDEWEB)

    Tufaile, A., E-mail:; Tufaile, A.P.B.


    We are reporting a new simple optical element to generate halos. We have observed interesting patterns of light scattering in Plateau borders in foams. In analogy to the atmospheric phenomena known as parhelic circle, sun dogs, and sun pillars, we have named the features of the patterns observed as parlaseric circle, laser dogs, and laser pillars. The triangular symmetry of the Plateau borders is analogous to the hexagonal symmetry of ice crystals which produce these atmospheric phenomena. Working with one Plateau border at a time, we have observed wave optics phenomena that are not perceived in the atmospheric phenomena, such as diffraction and interference. - Highlights: • We obtained halo formation from light scattering in a Plateau border using an experiment. • We explained halo formation using geometrical theory of diffraction. • An optical element based on a Plateau border is proposed. • We compared some aspects of the parhelic circle with the parlaseric circle.

  5. Correlation of parameters on preoperative CT images with intra-articular soft-tissue injuries in acute tibial plateau fractures: A review of 132 patients receiving ARIF. (United States)

    Tang, Hao-Che; Chen, I-Jung; Yeh, Yu-Cheng; Weng, Chun-Jui; Chang, Shih-Sheng; Chen, Alvin Chao-Yu; Chan, Yi-Sheng


    Tibial plateau fractures often occur in conjunction with soft-tissue injuries of knees. The hypothesis of this study is that parameters of CT imaging can predict intra-articular soft-tissue injuries. Patients who underwent arthroscopically assisted reduction and internal fixation (ARIF) for acute tibial plateau fractures performed by a single orthopedic surgeon between 2005 and 2015 were included in this retrospective study. Patients with concomitant ipsilateral femoral fractures, who had received revision surgery or who had undergone index surgery more than 30days from the event were excluded. We measured lateral plateau depression and widening, medial plateau depression and displacement, and column involvement observed on preoperative CT scans. Intra-articular soft-tissue injuries were diagnosed based on findings from knee arthroscopy. The correlation of imaging parameters with soft-tissue injuries was analyzed by the area under a receiver operating characteristic (AUROC) curve and multivariate logistic regression. One-hundred and thirty-two patients were enrolled in the study. The average age was 45.7±13.1 years (range: 18-75 years). Lateral tibial plateau depressions >11mm were significantly associated with increased risk of lateral meniscus tears (p=0.001). However, there was no significant threshold of lateral tibial plateau widening that could be used to predict lateral meniscus tear. Greater risk of anterior cruciate ligament (ACL) avulsion fracture was observed in younger patients, patients with high-energy-pattern tibial plateau fractures, patients with fractures involving anteromedial or posterolateral columns, and patients with medial tibial plateau displacement >3mm (pplateau depression and column involvement on preoperative CT scans can help predict a higher risk of lateral meniscus tear and ACL avulsion fracture respectively in patients with acute tibial plateau fractures. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Streamflow gains and losses in the Colorado River in northwestern Burnet and southeastern San Saba Counties, Texas (United States)

    Braun, Christopher L.; Grzyb, Scott D.


    In October 2012, the U.S. Geological Survey (USGS), in cooperation with the Central Texas Groundwater Conservation District, began an assessment to better understand if and where groundwater from the Ellenburger-San Saba aquifer is discharging to the Colorado River, and if and where Colorado River streamflow is recharging the Ellenburger-San Saba aquifer in the study area. Discharge measurements were made to determine if different reaches of the Colorado River in northwestern Burnet and southeastern San Saba Counties are gaining or losing streamflow, the locations and quantities of gains and losses, and whether the gains and losses can be attributed to interaction between the river and the Ellenbuger-San Saba aquifer. To assess streamflow gains and losses, two sets of synoptic gain-loss discharge measurements representing different streamflow conditions were completed. In the first gain-loss streamflow survey during December 3–6, 2012 (hereinafter the fall 2012 gain-loss survey), discharge measurements were made at low-flow conditions ranging from about 30 to 60 cubic feet per second (ft3/s) at seven locations along the Colorado River. In the second gain-loss streamflow survey during May 31–June 1, 2014 (hereinafter the spring 2014 gain-loss survey), discharge measurements were made at high-flow conditions ranging from about 660 to 900 ft3/s at 12 locations along the Colorado River.

  7. Evaluation of fecal contamination by human and ruminant sources in upper Fountain Creek, Colorado, 2007-2008, by using multiple lines of evidence: (United States)

    Stoeckel, Donald


    Fountain Creek is a high-gradient stream on the Front Range of the Rocky Mountains in Colorado. The headwaters of Fountain Creek drain Pikes Peak, a major destination for tourism. Fountain Creek is a drinking-water source for the City of Colorado Springs, Colorado, and is used for irrigation, recreation, and other purposes between Colorado Springs and the confluence with the Arkansas River at Pueblo, Colorado. In 2008, Fountain Creek was placed on the Colorado 303(d) list of impaired streams because of fecal contamination. Colorado uses a 30-day geometric mean standard of 126 Escherichia coli per 100 milliliters as its management goal for recreational waters. The objective of this study was to identify major sources of Escherichia coli in upper Fountain Creek during exceedances of the State recreational water standard. To meet this objective, a new approach was developed and tested that uses genetic marker analysis for microbial source tracking, along with other information, to evaluate potential contributions of fecal contamination from various sources.

  8. Loess Plateau storage of Northeastern Tibetan Plateau-derived Yellow River sediment. (United States)

    Nie, Junsheng; Stevens, Thomas; Rittner, Martin; Stockli, Daniel; Garzanti, Eduardo; Limonta, Mara; Bird, Anna; Andò, Sergio; Vermeesch, Pieter; Saylor, Joel; Lu, Huayu; Breecker, Daniel; Hu, Xiaofei; Liu, Shanpin; Resentini, Alberto; Vezzoli, Giovanni; Peng, Wenbin; Carter, Andrew; Ji, Shunchuan; Pan, Baotian


    Marine accumulations of terrigenous sediment are widely assumed to accurately record climatic- and tectonic-controlled mountain denudation and play an important role in understanding late Cenozoic mountain uplift and global cooling. Underpinning this is the assumption that the majority of sediment eroded from hinterland orogenic belts is transported to and ultimately stored in marine basins with little lag between erosion and deposition. Here we use a detailed and multi-technique sedimentary provenance dataset from the Yellow River to show that substantial amounts of sediment eroded from Northeast Tibet and carried by the river's upper reach are stored in the Chinese Loess Plateau and the western Mu Us desert. This finding revises our understanding of the origin of the Chinese Loess Plateau and provides a potential solution for mismatches between late Cenozoic terrestrial sedimentation and marine geochemistry records, as well as between global CO2 and erosion records.

  9. Plateau inflation in SUGRA-MSSM

    Directory of Open Access Journals (Sweden)

    Girish Kumar Chakravarty


    Full Text Available We explored a Higgs inflationary scenario in the SUGRA embedding of the MSSM in Einstein frame where the inflaton is contained in the SU(2 Higgs doublet. We include all higher order non-renormalizable terms to the MSSM superpotential and an appropriate Kähler potential which can provide slow-roll inflaton potential in the D-flat direction. In this model, a plateau-like inflation potential can be obtained if the imaginary part of the neutral Higgs acts as the inflaton. The inflationary predictions of this model are consistent with the latest CMB observations. The model represents a successful Higgs inflation scenario in the context of Supergravity and it is compatible with Minimal Supersymmetric extension of the Standard Model.

  10. Water vapour flux patterns and precipitation at Sierra de Guadarrama mountain range (Spain)

    National Research Council Canada - National Science Library

    Durán, L; Rodríguez‐Fonseca, B; Yagüe, C; Sánchez, E


    .... Sierra de Guadarrama is a part of the Iberian Peninsula Central System (Spain), a mountain range located in the center of an extensive plateau, dominated by a continental Mediterranean climate but under a strong Atlantic influence...

  11. A longitudinal survey of African animal trypanosomiasis in domestic cattle on the Jos Plateau, Nigeria: prevalence, distribution and risk factors. (United States)

    Majekodunmi, Ayodele O; Fajinmi, Akinyemi; Dongkum, Charles; Picozzi, Kim; Thrusfield, Michael V; Welburn, Susan C


    Trypanosomiasis is a widespread disease of livestock in Nigeria and a major constraint to the rural economy. The Jos Plateau, Nigeria was free from tsetse flies and the trypanosomes they transmit due to its high altitude and the absence of animal trypanosomiasis attracted large numbers of cattle-keeping pastoralists to inhabit the plateau. The Jos Plateau now plays a significant role in the national cattle industry, accommodating approximately 7% of the national herd and supporting 300,000 pastoralists and over one million cattle. However, during the past two decades tsetse flies have invaded the Jos Plateau and animal trypanosomiasis has become a significant problem for livestock keepers. In 2008 a longitudinal two-stage cluster survey on the Jos Plateau. Cattle were sampled in the dry, early wet and late wet seasons. Parasite identification was undertaken using species-specific polymerase chain reactions to determine the prevalence and distribution bovine trypanosomiasis. Logistic regression was performed to determine risk factors for disease. The prevalence of bovine trypanosomiasis (Trypanosoma brucei brucei, Trypanosoma congolense savannah, Trypanosoma vivax) across the Jos Plateau was found to be high at 46.8% (39.0 - 54.5%) and significant, seasonal variation was observed between the dry season and the end of the wet season. T. b. brucei was observed at a prevalence of 3.2% (1% - 5.5%); T. congolense at 27.7% (21.8% - 33.6%) and T. vivax at 26.7% (18.2% - 35.3%). High individual variation was observed in trypanosomiasis prevalence between individual villages on the Plateau, ranging from 8.8% to 95.6%. Altitude was found to be a significant risk factor for trypanosomiasis whilst migration also influenced risk for animal trypanosomiasis. Trypanosomiasis is now endemic on the Jos Plateau showing high prevalence in cattle and is influenced by seasonality, altitude and migration practices. Attempts to successfully control animal trypanosomiasis on the Plateau

  12. Behavioral mechanisms of male sterilization on plateau pika in the Qinghai-Tibet plateau. (United States)

    Liu, Ming; Qu, Jiapeng; Wang, Zengli; Wang, Yan-Ling; Zhang, Yanming; Zhang, Zhibin


    Fertility control is an alternative non-lethal method in the management of rodents. Previous modeling suggests that the efficacy of male sterilization depends on mating systems of animals, but behavioral mechanisms of male sterilization have not been investigated. Here we investigated the behavioral mechanism of the sterilant quinestrol in reducing the fertility of plateau pika (Ochotona curzoniae) inhabiting the Qinghai-Tibet plateau. Male pikas treated with quinestrol showed reduced aggression compared to control males, but they showed significantly higher levels of territorial behavior such as long-calls and long-chases. Levels of long-call and long-chase were negatively correlated with the number of newborn pikas in the family. Single-baiting of quinestrol effectively sterilized male pikas and reduced the pregnancy rate of female pikas; this was likely achieved by increased territorial behavior of sterilized pikas which resulted in unsuccessful invasions by fertile adult male pikas. Our study reveals a novel behavioral mechanism, increased territoriality in sterilized males, in the fertility control of plateau pikas. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. Taos Plateau Volcanic Project: A Vehicle for Integration of Concepts in Igneous Petrology (United States)

    Henry, D.; Dutrow, B.


    Integrating concepts of igneous petrology is generally a challenge, but can be effective in the context of a project based on actual field, geochemical and geochronological data. The final lab project in the igneous portion of petrology involves a series of volcanic and associated rock samples that were collected from the Taos Plateau Volcanic Field, New Mexico, USA. Samples were collected over an area of several tens of km2 throughout the Plateau and represent a spatially and temporally correlated rock suite related to continental rifting. Rift-related magmatism encompasses much of the diversity of terrestrial magma types. Compositions of mafic magmas range from tholeiite to some of the most silica-undersaturated magmas found on the continents. Large effusive eruptions from fissures are typical of some rifts, whereas others may be dominated by central vent cones or even silicic caldera complexes. The injection of mantle-derived magma in extending crust may have a profound effect on the rheology of the crust and, therefore, the style of deformation associated with extension. Most of these aspects of rift volcanism and a wide range of mafic to silicic magma compositions are represented in the Rio Grande rift and the volcanic rocks of the Taos Plateau. In addition, much published data exists for whole rock and trace element geochemistry as well as geochronology. Rock samples and associated information are presented so that the student must integrate multiple lines of evidence, petrographic, petrologic, geochemical and geochronological data in a geospatial framework, to establish a geologic history of the region. The student must also draw on skills learned in mineralogy and structural geology furthering core geoscience education. Subsequent to the petrology course, the students visit the Taos Plateau Volcanic Field during their required field camp, thus reinforcing the linkage between the classroom setting and geologic reality.


    Directory of Open Access Journals (Sweden)



    Full Text Available BACKGROUND: Tremendous advance in mechanization and fastness of travel have been accompanied by steep increase in number and severity of fractures and those of tibial plateau are no exception. Knee being one of the major weight bearing joints of the body, fractures around it will be of paramount importance. AIM OF STUDY: This study is to analyze the functional outcome of CRIF or ORIF with or without bone grafting in tibial plateau fractures in adults. MATERIALS AND METHODS: 30 cases of tibial plateau fractures treated by various modalities were studied from 1 - 8 - 2012 to 31 - 1 - 2014 at our institution and followed for a minimum of 6 months. Fractures were evaluated using Modified Rasmussen’s Clinical, Radiological grading system. RESULTS : The selected patients were evaluated thoroughly and after the relevant investigations, were taken for surgery. The fractures were classified as per the SCHATZKER’S types and operated accordingly with CRIF with Percutaneous cannulated cancellous screws, ORIF with buttress plate/LCP with or without bone grafting. Immobilization of fractures continued for 3 weeks by POP slab. Early range of motion was then started. Weight bearing up to 6 - 8 weeks was not allowed. The full weight bearing deferred until 12 weeks or complete fracture union . The knee range of motion was excellent to very good, gait and weight bearing after complete union was satisfactory, knee stiffness in 3 cases , wound dehiscence and infection in 1 case and non - union in none of our cases was noted. CONCLUSION: Functional outcome is better in operatively treated tibial plateau fractures in adults, because it gives excellent anatomical reduction and rigid fixation to restore articular congruity and early motion thereby preventing knee stiffness.

  15. Deciphering Paria and Little Colorado River flood regimes and their significance in multi-objective adaptive management strategies for Colorado River resources in Grand Canyon (United States)

    Jain, S.; Topping, D. J.; Melis, T. S.


    Planning and decision processes in the Glen Canyon Dam Adaptive Management Program (GCDAMP) strive to balance numerous, often competing, objectives, such as, water supply, hydropower generation, low flow maintenance, sandbars, recreational trout angling, endangered native fish, whitewater rafting, and other sociocultural resources of Glen Canyon National Recreation Area and Grand Canyon National Park. In this context, use of monitored and predictive information on warm-season Paria River floods (JUL-OCT, at point-to-regional scales) has been identified as lead information for a new 10-year long controlled flooding experiment (termed the High-Flow Experiment Protocol) intended to determine management options for rebuilding and maintaining sandbars below Glen Canyon Dam; an adaptive strategy that can potentially facilitate improved planning and dam operations. In this work, we focus on a key concern identified by the GCDAMP, related to the timing and volume of warm season tributary sand input from the Paria River into the Colorado River in Grand Canyon National Park. The Little Colorado River is an important secondary source of sand inputs to Grand Canyon, but its lower segment is also critical spawning habitat for the endangered humpback chub. Fish biologists have reported increased abundance of chub juveniles in this key tributary in summers following cool-season flooding (DEC-FEB), but little is known about chub spawning substrates and behavior or the role that flood frequency in this tributary may play in native fish population dynamics in Grand Canyon. Episodic and intraseasonal variations (with links to equatorial and sub-tropical Pacific sea surface temperature variability) in southwest hydroclimatology are investigated to understand the magnitude, timing and spatial scales of warm- and cool-season floods from these two important tributaries of the semi-arid Colorado Plateau. Coupled variations of floods (magnitude and timing) from these rivers are also

  16. 75 FR 23288 - Notice of Public Meeting, Southwest Colorado Resource Advisory Council Meeting (United States)


    ... will be held on June 4, 2010, in Dolores, Colorado; August 13, 2010, in Gunnison, Colorado; and October... 184, Dolores, Colorado 81323; August 13, 2010, at the Holiday Inn Express at 910 E. Tomichi, Gunnison...

  17. Stratigraphic evidence for the role of lake spillover in the inception of the lower Colorado River in southern Nevada and western Arizona (United States)

    House, P.K.; Pearthree, P.A.; Perkins, M.E.


    Late Miocene and early Pliocene sediments exposed along the lower Colorado River near Laughlin, Nevada, contain evidence that establishment of this reach of the river after 5.6 Ma involved flooding from lake spillover through a bedrock divide between Cottonwood Valley to the north and Mohave Valley to the south. Lacustrine marls interfingered with and conformably overlying a sequence of post-5.6 Ma finegrained valley-fill deposits record an early phase of intermittent lacustrine inundation restricted to Cottonwood Valley. Limestone, mud, sand, and minor gravel of the Bouse Formation were subsequently deposited above an unconformity. At the north end of Mohave Valley, a coarse-grained, lithologically distinct fluvial conglomerate separates subaerial, locally derived fan deposits from subaqueous deposits of the Bouse Formation. We interpret this key unit as evidence for overtopping and catastrophic breaching of the paleodivide immediately before deep lacustrine inundation of both valleys. Exposures in both valleys reveal a substantial erosional unconformity that records drainage of the lake and predates the arrival of sediment of the through-going Colorado River. Subsequent river aggradation culminated in the Pliocene between 4.1 and 3.3 Ma. The stratigraphic associations and timing of this drainage transition are consistent with geochemical evidence linking lacustrine conditions to the early Colorado River, the timings of drainage integration and canyon incision on the Colorado Plateau, the arrival of Colorado River sand at its terminus in the Salton Trough, and a downstream-directed mode of river integration common in areas of crustal extension. ?? 2008 The Geological Society of America.

  18. Butane Hash Oil Burns Associated with Marijuana Liberalization in Colorado. (United States)

    Bell, Cameron; Slim, Jessica; Flaten, Hanna K; Lindberg, Gordon; Arek, Wiktor; Monte, Andrew A


    Butane hash oil (BHO), also known as "amber," "dab," "glass," "honey," "shatter," or "wax," is a potent marijuana concentrate, containing up to 90 % tetrahydrocannabinol (THC). BHO is easily manufactured using highly volatile butane as a solvent. Our objective was to characterize hydrocarbon burns associated with BHO manufacture in Colorado. This was a cross-sectional study utilizing the National Burn Repository to capture all hydrocarbon burns reported to the local burn center from January 1st, 2008, through August 31st, 2014. We abstracted demographic and clinical variables from medical records for patients admitted for hydrocarbon burns associated with butane hash oil extraction. Twenty-nine cases of BHO burns were admitted to the local burn center during the study period. Zero cases presented prior to medical liberalization, 19 (61.3 %) during medical liberalization (Oct 2009-Dec 2013), and 12 (38.7 %) in 2014 since legalization. The majority of cases were Caucasian (72.4 %) males (89.7 %). Median age was 26 (range 15-58). The median total-body-surface-area (TBSA) burn size was 10 % (TBSA range 1-90 %). Median length of hospital admission was 10 days. Six required intubation for airway protection (21 %). Nineteen required skin grafting, eight wound care only, one required surgical fracture repair, and one required surgical debridement. Hydrocarbon burns associated with hash oil production have increased since the liberalization of marijuana policy in Colorado. A combination of public health messaging, standardization of manufacturing processes, and worker safety regulations are needed to decrease the risks associated with BHO production.

  19. Geology of the Thaumasia region, Mars: Plateau development, valley origins, and magmatic evolution (United States)

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


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

  20. Rehabilitation potential and practices of Colorado oil shale lands

    Energy Technology Data Exchange (ETDEWEB)

    Sims, P.L.; Redente, E.F.


    Considering the problems associated with rehabilitating oil shale disturbed lands in Colorado, a research grant was awarded to Colorado State University by US ERDA. The goal of this research program is to define the rehabilitation potential and practices of Colorado Oil Shale lands. Rehabilitation guidelines are presently being formulated through the study of long-term fertility requirements, soil microorganism dynamics and activity, rate and direction of secondary plant succession, and selection and improvement of plant materials.

  1. Energy research in Colorado higher education

    Energy Technology Data Exchange (ETDEWEB)


    This report catalogues the externally sponsored energy-related research currently being pursued in Colorado's state-supported research universities.This inventory of energy-related academic research demonstrates the extent, variety, nature, and degree of financial support of energy research in the state academic research community. Projects are briefly described, their principal investigator named, and the origin and amount of outside funding detailed.

  2. Green pricing: A Colorado case study

    Energy Technology Data Exchange (ETDEWEB)

    Blank, E.; Udall, J.R.


    A model program for green pricing targeted primarily at large customers is proposed in this paper. The program would create a partnership between a local community group, a renewables advocacy group, and several Colorado utilities. The first part of the paper summarizes pertinent background issues, including utility experience with green pricing programs. The rest of the paper outlines the program proposal, focusing primarily on organizational structure.

  3. Colorado K-12 & School Choice Survey: What Do Voters Say about K-12 Education? Polling Paper No. 26 (United States)

    DiPerna, Paul


    The purpose of the "Colorado K-12 & School Choice Survey" is to measure public opinion on, and in some cases awareness or knowledge of, a range of K-12 education topics and school choice reforms. A total of 601 telephone interviews were completed from August 29 to September 16, 2015, with questions on the direction of K-12 education,…

  4. A model species for agricultural pest genomics: the genome of the Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae) (United States)

    The Colorado potato beetle, Leptinotarsa decemlineata Say, is one of the most challenging agricultural pests to manage and has shown a spectacular ability to rapidly adapt to a broad range of solanaceaeous (nightshade/potato) plants, variable climate during its global invasion, and, most notably, an...

  5. Map, directory, and statistics of permitted Colorado coal mines, 1983. [Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Rushworth, P.; Kelso, B.S.; Ladwig, L.R.


    This directory is an update and revision of Map Series 15 published in 1981. The purpose of the publication is to provide insight into the Colorado coal industry. This report presents geologic, production and location data for permitted Colorado coal mines. Additional information was obtained by contacting individual mine personnel via mail and telephone. Mine information is presented for active, interim and reclamation permits. Exploration mines are not included due to restriction of access to these Mined Land Reclamation Division files. The accompanying map locates mines and lists them by county, coal mine name and parent company. Production data are tabulated by portal by the Colorado Division of Mines. Mines are plotted on the map by common permit area, but split out by portal in the text. A permit area may contain more than one portal, however, a permit area is not necessarily contiguous. The information contained in this report is the best available at the time of writing, August 1, 1983.

  6. Annual suspended-sediment loads in the Colorado River near Cisco, Utah, 1930-82 (United States)

    Thompson, K.R.


    The Colorado River upstream of gaging station 09180500 near Cisco, Utah, drains about 24,100 square miles in Utah and Colorado. Altitudes in the basin range from 12,480 feet near the headwaters to 4,090 feet at station 09180500. The average annual precipitation for 1894-1982 near the station was 7.94 inches. The average annual precipitation near the headwaters often exceeds 50 inches. Rocks ranging in age from Precambrian to Holocene are exposed in the drainage basin upstream from station 09180500. Shale, limestone, siltstone, mudstone, and sandstone probably are the most easily eroded rocks in the basin, and they contribute large quantities of sediment to the Colorado River. During 1930-82, the U.S. Geological Survey collected records of fluvial sediment at station 09180500. Based on these records, the mean annual suspended-sediment load was 11,390,000 tone, ranging from 2,038,000 tons in water year 1981 to 35,700,000 tons in water year 1938. The minimum daily load of 14 tons was on August 22, 1960, and the maximum daily load of 2,790,000 tons was on October 14, 1941. (USGS)

  7. Ti-bearing aenigmatite from Djinga Tadorgal (Adamawa plateau ...

    African Journals Online (AJOL)

    Ti-bearing aenigmatite from Djinga Tadorgal (Adamawa plateau) and Sao Tomé (Cameroon Line) phonolites: geochemical implications and application of the QUILF thermobarometer for the crystallization conditions.

  8. Coccidioidomycosis in Chicken Pullets in Jos, Plateau State, Nigeria ...

    African Journals Online (AJOL)

    Coccidioidomycosis in Chicken Pullets in Jos, Plateau State, Nigeria: A Case Report. AR Jambalang, IN Ogo, JO Ibu, M Gisilanbe, W Bertu, L Jwander, B Benjamin, S Chukwukere, Y Nasir, N Sanda, A Benshak, GOA Agada, M Kubo ...

  9. Strontium isotope evidence for a highly mobile population on the Pamir Plateau 2500 years ago (United States)

    Wang, Xueye; Tang, Zihua; Wu, Jing; Wu, Xinhua; Wu, Yiqun; Zhou, Xinying


    Archeological researches have proposed arguments for human mobility and long-distance trading over the Eurasia before the Silk Roads. Here we utilize biologically available strontium isotope analysis to assess the extent of pre-Silk Road population movements and cultural communications across the Asian interior. From an early Iron Age cemetery (ca. 2500 yr B.P.) on the eastern Pamir Plateau, mean 87Sr/86Sr ratios from 34 individuals display considerable isotopic variability, and 10 individuals are distinguished as migrants based on the local strontium isotope range of 0.710296-0.710572 defined by 12 ovicaprine bones. Comparison of the proportion (10/34) with the regional census data completed in 1909 A.D. (3% non-locals) suggests a highly migratory behavior on the plateau 2500 years ago. Furthermore, exotic mortuary objects, such as silk fabrics from eastern China and angular harp originated from the Near East, clearly demonstrate an interaction between different cultures on the plateau before the establishment of the Silk Road.

  10. Colorado Plateau Rapid Ecoregion Assessment Change Agents - Development - Current, Near-Term, and Long-Term Potential High Landscape Development (United States)

    Bureau of Land Management, Department of the Interior — This map shows areas of high current, near-term, and long-term potential landscape development, based on factors such as urban areas, agriculture, roads, and energy...

  11. The Colorado Plateau Coring Project (CPCP): A Continuous Cored Record of Triassic Continental Environmental Change in Western North America (United States)

    Olsen, P. E.; Geissman, J. W.; Gehrels, G. E.; Irmis, R. B.; Kent, D. V.; Mundil, R.; Parker, W.; Sha, J.; Molina-Garza, R. S.; Kuerschner, W.; Bachmann, G. H.; Schaller, M. F.; Zakharova, N. V.; Colbert, M.


    The Triassic Period (251.9-201.3 Ma) is bound by two of the Earth's largest mass extinctions, suffered several giant bolide impacts and eruption of 3 large igneous provinces, and witnessed evolution of the main components of modern tetrapod communities, and yet has sparse geochronological calibration. To bridge this gap, NSF- and ICDP-funded coring of Phase 1 of the CPCP finished in 12/2013 with the recovery of two major cores (1A, 518m and 2B, 253m; 31km apart) from opposites sides of Petrified Forest National Park spanning nearly the entire Triassic sequence (Chinle & Moenkopi fms) with many U-Pb datable levels (1,2,3) and a recoverable paleomagnetic polarity record (4). The cores will provide a U-Pb and paleomagnetic exportable time scale and sedimentary and geochemical proxies with undoubted superposition testing the motivating hypotheses of: 1) the accuracy of orbitally-paced cyclicity of the Newark APTS (5); 2) apparent climate trends as a function of drift through climate belts (6) and atmospheric CO2 (7); 3) the temporal link between the mid-Late Triassic biotic turnover and the ~100 km Manicouagan impact (1); and 4) the delayed ecological dominance of dinosaurs coupled to climate-driven provinciality (1,8). For orientation, the cores were drilled using a azimuth-tracking device, deviated 30° and 15° from vertical to the SE and S, and CT-scanned. The unprecedented sedimentological and stratigraphic detail visible in the CT-scans, and geophysical logs, plus the ~100% recovery promises successful tests of the motivating hypotheses and provide a superbly detailed reference section for this key episode in Earth system history. 1, Irmis+,2011, EPSL 309:258; 2, Ramazani+, 2011, GSA Bull. 123:2142; 3, Ramazani+, 2014, AJS 314:981; 4, Steiner & Lucas, 2000, JGR B 105:25791; 5, Kent & Olsen, 1999, JGR 104(B6):12831-12841; 6, Kent and Tauxe, 2005, Science 307:240-244; 7, Schaller+, 2012, EPSL 323-324:27-39; 8, Kent +, 2014, PNAS 111:7958-7963.

  12. Colorado Plateau Rapid Ecoregion Assessment Management Question E2: Where are the areas with potential to change from wildfire? (United States)

    Bureau of Land Management, Department of the Interior — This map shows current, near-term, and long-term estimates of fire occurrence potential due to human and natural causes. These estimates were developed using a...

  13. Preventing regime shifts on the Colorado Plateau: Application of ecological threshold concepts to land management decision making (United States)

    Investigating the mechanisms responsible for ecological thresholds is essential to understanding processes leading to ecosystem regime shifts. Dryland ecosystems are especially prone to threshold behavior wherein stressor-mediated alteration of patterns and processes can shift systems to alternative...

  14. Effects of tibial plateau angle and spacer thickness applied during in vitro canine total knee replacement on three-dimensional kinematics and collateral ligament strain. (United States)

    Baker, Katherine M; Foutz, Timothy L; Johnsen, Kyle J; Budsberg, Steven C


    To quantify the 3-D kinematics and collateral ligament strain of stifle joints in cadaveric canine limbs before and after cranial cruciate ligament transection followed by total knee replacement (TKR) involving various tibial plateau angles and spacer thicknesses. 6 hemi-pelvises collected from clinically normal nonchondrodystrophic dogs (weight range, 25 to 35 kg). Hemi-pelvises were mounted on a modified Oxford knee rig that allowed 6 degrees of freedom of the stifle joint but prevented mechanical movement of the hip and tarsal joints. Kinematics and collateral ligament strain were measured continuously while stifle joints were flexed. Data were again collected after cranial cruciate ligament transection and TKR with combinations of 3 plateau angles (0°, 4°, and 8°) and spacer thicknesses (5, 7, and 9 mm). Presurgical (ie, normal) stifle joint rotations were comparable to those previously documented for live dogs. After TKR, kinematics recorded for the 8°, 5-mm implant most closely resembled those of unaltered stifle joints. Decreasing the plateau angle and increasing spacer thickness altered stifle joint adduction, internal rotation, and medial translation. Medial collateral ligament strain was minimal in unaltered stifle joints and was unaffected by TKR. Lateral collateral ligament strain decreased with steeper plateau angles but returned to a presurgical level at the flattest plateau angle. Among the constructs tested, greatest normalization of canine stifle joint kinematics in vitro was achieved with the steepest plateau angle paired with the thinnest spacer. Furthermore, results indicated that strain to the collateral ligaments was not negatively affected by TKR.

  15. Economic impact study of the Uranium Mill Tailings Remedial Action project in Colorado: Colorado state fiscal year 1995

    Energy Technology Data Exchange (ETDEWEB)



    This Colorado economic impact study summarizes employment and economic benefits to the state from activities associated with the Uranium Mill Tailings Remedial Action (UMTRA) Project during Colorado state fiscal year (FY) 1995 (1 July 1994 through 30 June 1995). To capture employment information, a questionnaire was distributed to subcontractor employees at the active UMTRA Project sites of Grand Junction, Gunnison, Maybell, Naturita, Rifle, and Slick Rock, Colorado. Economic data were requested from the Remedial Action Contractor (RAC), the Technical Assistance Contractor (TAC) and the US Department of Energy (DOE). The most significant benefits associated with the UMTRA Project in Colorado are summarized.

  16. Economic impact study of the Uranium Mill Tailings Remedial Action Project in Colorado: Colorado state fiscal year 1993

    Energy Technology Data Exchange (ETDEWEB)


    The Colorado economic impact study summarizes employment and economic benefits to the state from activities associated with the Uranium Mill Tailings Remedial Action (UMTRA) Project during Colorado state fiscal year 1993 (July 1, 1992, through June 30, 1993). To capture employment benefits, a questionnaire was distributed to subcontractor employees at the active UMTRA Project sites of Grand Junction, Rifle, and Gunnison, Colorado. An estimated 52 percent of the employees working on the UMTRA Project responded to this information request. Economic data were requested from each site prime subcontractor, as well as from the Remedial Action Contractor. The most significant benefits associated with the UMTRA Project in Colorado are summarized.

  17. Surface Wave Attenuation in the Tibetan Plateau from Ambient Noise (United States)


    AFRL-RV-PS- TR-2015-0150 AFRL-RV-PS- TR-2015-0150 SURFACE WAVE ATTENUATION IN THE TIBETAN PLATEAU FROM AMBIENT NOISE University of Illinois at...DATES COVERED (From - To) 01 May 2012 to 31 Aug 2015 4. TITLE AND SUBTITLE Surface Wave Attenuation in the Tibetan Plateau from Ambient Noise 5a...extract amplitude information from the empirical Green functions (EGF) derived from ambient noise correlations and to map the attenuation of the

  18. Return to sport following tibial plateau fractures: A systematic review


    Robertson, Greg A J; Wong, Seng J; Wood, Alexander M.


    AIM To systemically review all studies reporting return to sport following tibial plateau fracture, in order to provide information on return rates and times to sport, and to assess variations in sporting outcome for different treatment methods. METHODS A systematic search of CINAHAL, Cochrane, EMBASE, Google Scholar, MEDLINE, PEDro, Scopus, SPORTDiscus and Web of Science was performed in January 2017 using the keywords ?tibial?, ?plateau?, ?fractures?, ?knee?, ?athletes?, ?sports?, ?non-oper...

  19. Climate change and its impacts on vegetation distribution and net primary productivity of the alpine ecosystem in the Qinghai-Tibetan Plateau. (United States)

    Gao, Qingzhu; Guo, Yaqi; Xu, Hongmei; Ganjurjav, Hasbagen; Li, Yue; Wan, Yunfan; Qin, Xiaobo; Ma, Xin; Liu, Shuo


    Changes in climate have caused impacts on ecosystems on all continents scale, and climate change is also projected to be a stressor on most ecosystems even at the rate of low- to medium-range warming scenarios. Alpine ecosystem in the Qinghai-Tibetan Plateau is vulnerable to climate change. To quantify the climate change impacts on alpine ecosystems, we simulated the vegetation distribution and net primary production in the Qinghai-Tibetan Plateau for three future periods (2020s, 2050s and 2080s) using climate projection for RCPs (Representative Concentration Pathways) RCP4.5 and RCP8.5 scenarios. The modified Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ model) was parameter and test to make it applicable to the Qinghai-Tibetan Plateau. Climate projections that were applied to LPJ model in the Qinghai-Tibetan Plateau showed trends toward warmer and wetter conditions. Results based on climate projections indicated changes from 1.3°C to 4.2°C in annual temperature and changes from 2% to 5% in annual precipitation. The main impacts on vegetation distribution was increase in the area of forests and shrubs, decrease in alpine meadows which mainly replaced by shrubs which dominated the eastern plateau, and expanding in alpine steppes to the northwest dominated the western and northern plateau. The NPP was projected to increase by 79% and 134% under the RCP4.5 and RCP8.5. The projected NPP generally increased about 200gC·m(-2)·yr(-1) in most parts of the plateau with a gradual increase from the eastern to the western region of the Qinghai-Tibetan Plateau at the end of this century. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Investigations of the gravity profile below the Tibetan plateau (United States)

    Shen, W. B.; Han, J. C.


    Scientists pay great attention to the structure and dynamics of the Tibetan plateau due to the fact that it is a natural experiment site for geoscience studies. The gravity profiles below the Tibetan plateau with successive high-accuracy play more and more significant role in studying the structure and evolution of the Tibetan plateau. This study focuses on determining the inner gravity field of the Tibetan plateau until to the depth of D and interpret possible mechanism of the gravity profile below the Tibetan plateau, especially reinvestigating the isostasy problem (Pratt hypothesis and Airy hypothesis). The inner gravity field below the Tibetan plateau is determined based on a simple technique (i.e. a combination of Newtonian integral, downward continuation of gravity field, and "remove-restore" scheme) and the following datasets: the external Earth gravitational model EGM2008 and the digital topographic model DTM2006.0 released by NGA (National Geospatial-Intelligence Agency, USA), and the crust density distribution model CRUST2.0 released by NGS (National Geological Survey, USA). This study is supported by Natural Science Foundation China (grant No.40974015; No.41174011).

  1. A retrospective study of tibial plateau translation following tibial plateau levelling osteotomy stabilisation using three different plate types. (United States)

    Woodbridge, N; Corr, S A; Grierson, J; Arthurs, G


    To retrospectively evaluate mediolateral translation of the proximal tibial segment (tibial plateau) after tibial plateau levelling osteotomy (TPLO), stabilised with three types of plate. Pre- and postoperative radiographs of 79 dogs that had TPLO surgery using three different types of plates were reviewed. Two plate types incorporated non-locking screws: Slocum (22 cases) and Orthomed Delta (33 cases) plates. The third plate type incorporated locking screws: Synthes TPLO Locking Compression Plate (LCP) (24 cases). The radiographs were viewed by three Diplomate surgeons who were blinded to the type of implant used. Medial or lateral translation of the proximal tibial plateau relative to the tibial diaphysis was assessed and measured at the lateral tibial cortex at the osteotomy site. Mean lateral translation of the tibial plateau was significantly greater when using the Synthes TPLO LCP with locking screws (+2.1 mm) compared to the non-locking Slocum (+0.4 mm) or Orthomed Delta (0.0 mm) plates. The use of the Synthes TPLO LCP will maintain a malalignment of the tibial plateau. Accurate alignment of the tibial plateau must be ensured prior to application of the Synthes TPLO LCP.

  2. Colorado Fathers' Resource Guide = Guia de Recursos para los Padres en Colorado. (United States)

    Colorado Foundation for Families and Children, Denver.

    Developed through the Colorado Fatherhood Connection, this guide, in English- and Spanish-language versions, provides suggestions and resources for fathers as well as tips on discipline, communication, and activities fathers can do with their children. Topics addressed in the guide include characteristics of responsible fatherhood, characteristics…

  3. Electric Vehicles in Colorado: Anticipating Consumer Demand for Direct Current Fast Charging

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Eric W. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rames, Clement L. [National Renewable Energy Laboratory (NREL), Golden, CO (United States)


    To support the State of Colorado in planning for growth in direct current fast charging (DCFC) for electric vehicles, the National Renewable Energy Laboratory (NREL) has partnered with the Regional Air Quality Council (RAQC) and the Colorado Department of Transportation (CDOT) to analyze a number of DCFC investment scenarios. NREL analyzed existing electric vehicle registration data from IHS Markit (IHS) to highlight early trends in the electric vehicle market, which were compared with sales forecasts predicting large growth in the Colorado electric vehicle market. Electric vehicle forecasts were then used to develop future DCFC scenarios to be evaluated in a simulation environment to estimate consumer benefits of the hypothetical DCFC networks in terms of increased driving range and electric vehicle miles traveled (eVMT). Simulated utilization of the hypothetical DCFC networks was analyzed for geographic trends, particularly for correlations with vehicle electric range. Finally, a subset of simulations is presented for consumers with potentially inconsistent access to charging at their home location and presumably greater reliance on public DCFC infrastructure.

  4. Climatology of extreme daily precipitation in Colorado and its diverse spatial and seasonal variability (United States)

    Mahoney, Kelly M.; Ralph, F. Martin; Walter, Klaus; Doesken, Nolan; Dettinger, Michael; Gottas, Daniel; Coleman, Timothy; White, Allen


    The climatology of Colorado’s historical extreme precipitation events shows a remarkable degree of seasonal and regional variability. Analysis of the largest historical daily precipitation totals at COOP stations across Colorado by season indicates that the largest recorded daily precipitation totals have ranged from less than 60 mm day−1 in some areas to more than 250 mm day−1 in others. East of the Continental Divide, winter events are rarely among the top 10 events at a given site, but spring events dominate in and near the foothills; summer events are most common across the lower-elevation eastern plains, while fall events are most typical for the lower elevations west of the Divide. The seasonal signal in Colorado’s central mountains is complex; high-elevation intense precipitation events have occurred in all months of the year, including summer, when precipitation is more likely to be liquid (as opposed to snow), which poses more of an instantaneous flood risk. Notably, the historic Colorado Front Range daily rainfall totals that contributed to the damaging floods in September 2013 occurred outside of that region’s typical season for most extreme precipitation (spring–summer). That event and many others highlight the fact that extreme precipitation in Colorado has occurred historically during all seasons and at all elevations, emphasizing a year-round statewide risk.

  5. Colorado Air Quality Control Regulations and Ambient Air Quality Standards. (United States)

    Colorado State Dept. of Health, Denver. Div. of Air Pollution Control.

    Regulations and standards relative to air quality control in Colorado are defined in this publication. Presented first are definitions of terms, a statement of intent, and general provisions applicable to all emission control regulations adopted by the Colorado Air Pollution Control Commission. Following this, three regulations are enumerated: (1)…

  6. 76 FR 72437 - Minor Boundary Revision at Colorado National Monument (United States)


    ...-72438] [FR Doc No: 2011-30167] DEPARTMENT OF THE INTERIOR National Park Service Minor Boundary Revision at Colorado National Monument AGENCY: National Park Service, Interior. ACTION: Notification of... of Colorado National Monument is modified to include an additional two and forty-five hundredths (2...

  7. Updated estimates of long-term average dissolved-solids loading in streams and rivers of the Upper Colorado River Basin (United States)

    Tillman, Fred D; Anning, David W.


    The Colorado River and its tributaries supply water to more than 35 million people in the United States and 3 million people in Mexico, irrigating over 4.5 million acres of farmland, and annually generating about 12 billion kilowatt hours of hydroelectric power. The Upper Colorado River Basin, part of the Colorado River Basin, encompasses more than 110,000 mi2 and is the source of much of more than 9 million tons of dissolved solids that annually flows past the Hoover Dam. High dissolved-solids concentrations in the river are the cause of substantial economic damages to users, primarily in reduced agricultural crop yields and corrosion, with damages estimated to be greater than 300 million dollars annually. In 1974, the Colorado River Basin Salinity Control Act created the Colorado River Basin Salinity Control Program to investigate and implement a broad range of salinity control measures. A 2009 study by the U.S. Geological Survey, supported by the Salinity Control Program, used the Spatially Referenced Regressions on Watershed Attributes surface-water quality model to examine dissolved-solids supply and transport within the Upper Colorado River Basin. Dissolved-solids loads developed for 218 monitoring sites were used to calibrate the 2009 Upper Colorado River Basin Spatially Referenced Regressions on Watershed Attributes dissolved-solids model. This study updates and develops new dissolved-solids loading estimates for 323 Upper Colorado River Basin monitoring sites using streamflow and dissolved-solids concentration data through 2012, to support a planned Spatially Referenced Regressions on Watershed Attributes modeling effort that will investigate the contributions to dissolved-solids loads from irrigation and rangeland practices.

  8. DUID prevalence in Colorado's DUI citations. (United States)

    Wood, Ed; Salomonsen-Sautel, Stacy


    There are limited studies that measure the prevalence of driving under the influence of drugs (DUID) based upon impairment measures because most prevalence studies are based on drug tests. The aim of this study was to provide the first estimate of DUID prevalence in Colorado using data collected by Colorado law enforcement officers in vehicular homicide (VH) and vehicular assault (VA) cases, and reported in court records. The four research questions of this study were answered by completing independent t-tests or Mann-Whitney U tests, Pearson chi-square analyses or Fisher's exact tests, and Kruskal-Wallis tests. Seventy percent (119 out of 170) of the cases involved alcohol only and 30% (51 out of 170) involved drugs. Of the latter cases, 32 cases involved a combination of alcohol and drugs and 19 cases identified drugs only, with no alcohol. Marijuana was the most commonly cited drug (23 cases); however, it was the sole impairing substance identified in only three cases. Polydrug use was very common among DUID cases, which makes it difficult to identify which drug or drugs caused the impairment responsible for the Driving Under the Influence citation. This study revealed tha (a) drugged driving is a frequent cause of DUI citations in cases charged with VH or VA; (b) that polydrug use, rather than marijuana, is the most common cause of drugged driving in Colorado; and (c) that current warrant procedures render blood test results meaningless in cases of marijuana-impairment. States should collect and analyze DUID data to ensure legislators focus on the right DUID problems to improve biological testing for drugs, adopt more appropriate roadside testing, and enact stronger DUID laws to protect the public. Copyright © 2016 Elsevier Ltd and National Safety Council. All rights reserved.

  9. Development of industrial minerals in Colorado (United States)

    Arbogast, Belinda F.; Knepper, Daniel H.; Langer, William H.; Cappa, James A.; Keller, John W.; Widmann, Beth L.; Ellefsen, Karl J.; Klein, Terry L.; Lucius, Jeffrey E.; Dersch, John S.


    Technology and engineering have helped make mining safer and cleaner for both humans and the environment. Inevitably, mineral development entails costs as well as benefits. Developing a mine is an environmental, engineering, and planning challenge that must conform to many Federal, State, and local regulations. Community collaboration, creative design, and best management practices of sustainability and biodiversity can be positive indicators for the mining industry. A better understanding of aesthetics, culture, economics, geology, climate, vegetation and wildlife, topography, historical significance, and regional land planning is important in resolving land-use issues and managing mineral resources wisely. Ultimately, the consuming public makes choices about product use (including water, food, highways, housing, and thousands of other items) that influence operations of the mineral industry. Land planners, resource managers, earth scientists, designers, and public groups have a responsibility to consider sound scientific information, society's needs, and community appeals in making smart decisions concerning resource use and how complex landscapes should change. An effort to provide comprehensive geosciences data for land management agencies in central Colorado was undertaken in 2003 by scientists of the U.S. Geological Survey and the Colorado Geological Survey. This effort, the Central Colorado Assessment Project, addressed a variety of land-use issues: an understanding of the availability of industrial and metallic rocks and minerals, the geochemical and environmental effects of historic mining activity on surface water and groundwater, and the geologic controls on the availability and quality of groundwater. The USDA Forest Service and other land management agencies have the opportunity to contribute to the sustainable management of natural aggregate and other mineral resources through the identification and selective development of mineral resources and the

  10. Phylogeographic investigation and ecological niche modelling of the endemic frog species Nanorana pleskei revealed multiple refugia in the eastern Tibetan Plateau. (United States)

    Wang, Bin; Xie, Feng; Li, Jiannan; Wang, Gang; Li, Cheng; Jiang, Jianping


    The largest plateau Tibetan Plateau supplied an excellent opportunity to investigate the influence of the Pleistocene events on the high-elevation species. To test for the alternative hypotheses of Pleistocene glacial refugia, we used partial sequences of two mitochondrial genes and one nuclear gene to examine the phylogeographic patterns of the endemic frog species Nanorana pleskei across its known range in the eastern Tibetan Plateau, and conducted species distribution modelling (SDM) to explore changes of its distribution range through current and paleo periods. In all data sets, the species was divided into lineage north occupying open plateau platform and lineage south colonizing the mountainous plateau. The divergence of two major clades was estimated at the early Pleistocene. In mtDNA, lineage north contained northeastern and northwestern sublineages, and lineage south had two overlapping-distributed sublineages. Different lineages possessed distinct demographic characteristics, i.e., subdivision in the northeastern sublineage, historical bottleneck effects and recent expansions in the northwestern sublineage and the southeastern sublineage. SDMs depicted that stable suitable habitats had existed in the upper-middle streams of the Yellow River, Dadu River, Jinsha River and Yalong River. These regions were also recognized as the ancestral areas of different lineages. In conclusion, Nanorana pleskei lineages have probably experienced long-term separations. Stable suitable habitats existing in upper-middle streams of major rivers on the eastern Tibetan Plateau and distinct demographic dynamics of different lineages indicated that the lineages possessed independent evolutionary processes in multiple glacial refugia. The findings verified the profound effects of Pleistocene climatic fluctuations on the plateau endemic species.

  11. Phylogeographic investigation and ecological niche modelling of the endemic frog species Nanorana pleskei revealed multiple refugia in the eastern Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Bin Wang


    Full Text Available The largest plateau Tibetan Plateau supplied an excellent opportunity to investigate the influence of the Pleistocene events on the high-elevation species. To test for the alternative hypotheses of Pleistocene glacial refugia, we used partial sequences of two mitochondrial genes and one nuclear gene to examine the phylogeographic patterns of the endemic frog species Nanorana pleskei across its known range in the eastern Tibetan Plateau, and conducted species distribution modelling (SDM to explore changes of its distribution range through current and paleo periods. In all data sets, the species was divided into lineage north occupying open plateau platform and lineage south colonizing the mountainous plateau. The divergence of two major clades was estimated at the early Pleistocene. In mtDNA, lineage north contained northeastern and northwestern sublineages, and lineage south had two overlapping-distributed sublineages. Different lineages possessed distinct demographic characteristics, i.e., subdivision in the northeastern sublineage, historical bottleneck effects and recent expansions in the northwestern sublineage and the southeastern sublineage. SDMs depicted that stable suitable habitats had existed in the upper-middle streams of the Yellow River, Dadu River, Jinsha River and Yalong River. These regions were also recognized as the ancestral areas of different lineages. In conclusion, Nanorana pleskei lineages have probably experienced long-term separations. Stable suitable habitats existing in upper-middle streams of major rivers on the eastern Tibetan Plateau and distinct demographic dynamics of different lineages indicated that the lineages possessed independent evolutionary processes in multiple glacial refugia. The findings verified the profound effects of Pleistocene climatic fluctuations on the plateau endemic species.

  12. Aftershock Decay Rates in the Iranian Plateau (United States)

    Ommi, S.; Zafarani, H.; Zare, M.


    Motivated by the desire to have more information following the occurrence of damaging events, the main purpose of this article is to study aftershock sequence parameters in the Iranian plateau. To this end, the catalogue of the Iranian earthquakes between 2002 to the end of 2013 has been collected and homogenized among which 15 earthquakes have been selected to study their aftershock decay rates. For different tectonic provinces, the completeness magnitudes ( M c) of the earthquake catalogue have been calculated in different time intervals. Also, the M c variability in spatial and temporal windows has been determined for each selected event. For major Iranian earthquakes, catalogue of aftershocks has been collected thanks to three declustering methods: first, the classical windowing method of Gardner and Knopoff (Bull Seismol Soc Am 64:1363-1367, 1974); second, a modified version of this using spatial windowing based on the Wells and Coppersmith (Bull Seismol Soc Am 84:974-1002, 1994) relations; and third, the Burkhard and Grünthal (Swiss J Geosci 102:149-188, 2009) scheme. Effects of the temporal windows also have been investigated using the time periods of 1 month, 100 days, and 1 year in the declustering method of Gardner and Knopoff (Bull Seismol Soc Am 64:1363-1367, 1974). In the next step, the modified Omori law coefficients have been calculated for the 15 selected earthquakes. The calibrated regional generic model describing the temporal and magnitude distribution of aftershocks is of interest for time-dependent seismic hazard forecasts. The regional characteristics of the aftershock decay rates have been studied for the selected Iranian earthquakes in the Alborz, Zagros and Central Iran regions considering their different seismotectonics regimes. However, due to the lack of sufficient data, no results have been reported for the Kopeh-Dagh and Makran seismotectonic regions.

  13. Soil temperature change on the Tibetan Plateau (United States)

    Zhu, F.; Cuo, L.; Zhang, Y.; Luo, J. J.


    Increased radiative forcing has resulted in the global warming that includes the warming in air and soil over the past decades. The warming at the Earth's surface propagates or conducts downward into the ground and modifies the ambient ground thermal regime. In addition to the surface radiation that directly heats the soil, the other soil heat fluxes associated with atmospheric circulations of various scales are important mechanisms as well. The quantification of the causal relationships between the radiation, large scale atmospheric circulations and soil temperature change in the upper few meters on the Tibetan Plateau (TP) is the objective of this study. Daily soil temperature data during 1980-2013 at various depths from surface down to 3.2 m depth at 88 stations located on the TP obtained from China Meteorological Administration are used to investigate the changes in soil temperature. After the quality control, the Mann-Kendall trend, EOF and regression analyses are applied to analyze the soil temperature and radiation data. The Mann-Kendall test shows that soil temperature at layers above 3.2-m-depth increases from 1980 to 2013 at most stations on the TP, although the warming rate varies among stations. Time series of the EOF analysis shows that a hiatus in the soil temperature warming has occurred since 2004 on the TP, which is several years behind the hiatus of the global warming but is similar to the air temperature change on the TP. Besides, we do not find a clear phase delay from the surface to the 3.2m level. Net surface solar radiation, long wave radiation that partly reflects the greenhouse gases forcing, latent and sensible heat fluxes are examined to understand the underlying mechanisms for the distinct warming of the soil on the TP. Contributions of the atmospheric circulation changes, induced by either internal variability or external forcing or both of the two factors, are also examined. The above analysis results will be presented at the

  14. Extended Anterolateral Approach for Complex Lateral Tibial Plateau Fractures. (United States)

    Kfuri, Mauricio; Schatzker, Joseph; Castiglia, Marcello Teixeira; Giordano, Vincenzo; Fogagnolo, Fabricio; Stannard, James P


    Complex fractures of the lateral tibial plateau may extend to the posterior rim of the knee and to the tibial spines. Displaced fractures of the posterolateral corner of the tibial plateau may result in joint incongruity and instability, especially with the knee in flexion. Anatomical reduction of the joint surface and containment of the tibial rim are the primary goals of the treatment in such cases. Dedicated surgical approaches including dissection of the peroneal nerve, sometimes in association with an osteotomy of the fibular head are typically used to address these injuries. Some techniques require special positioning of the patient on the operative table. Anatomical studies of the knee allowed us to conclude that an osteotomy of the lateral epicondyle of the femur may be a natural extension of the standard anterolateral approach to the tibial plateau. The main advantage of this approach is the broad exposure of the lateral joint surface, allowing its anatomical reduction. It does not violate the proximal tibiofibular joint or pose a risk to the peroneal nerve. The main limitation is the lack of visualization of the posterior metaphysis of the tibia, preventing the application of a buttress plate parallel to the plane of fracture split. To overcome this limitation, we describe a method to support the posterior tibial plateau rim, in cases of bicondylar tibial plateau fractures, combining the extended anterolateral with the posteromedial approach. For selected cases, with a significant compromise of the posterolateral and anterolateral quadrants of the tibial plateau, including the tibial spines, the extended anterolateral approach may be complemented by a planned detachment of the anterior horn of the lateral meniscus. In such variant, a complete exposure of the entire surface of the lateral tibial plateau and tibial spines is achievable, assuring optimal conditions for an anatomical reduction of the articular surface. Thieme Medical Publishers 333 Seventh

  15. Rawhide Energy Station, Fort Collins, Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Peltier, R.


    The staff of Platte River Power Authority's Rawhide Energy Station have been racking up operating stats and an environmental performance record that is the envy of other plant managers. In the past decade Rawhide has enjoyed an equivalent availability factor in the mid to high 90s and an average capacity factor approaching 90%. Still not content with this performance, Rawhide invested in new technology and equipment upgrades to further optimise performance, reduce emissions, and keep cost competitive. The Energy Station includes four GE France 7EA natural gas-fired turbines totalling 260 MW and a 274 MW coal-fired unit located in northeastern Colorado. 7 figs.

  16. The Change in the area of various land covers on the Tibetan Plateau during 1957-2015 (United States)

    Cuo, Lan; Zhang, Yongxin


    With average elevation of 4000 m and area of 2.5×106 km2, Tibetan Plateau hosts various fragile ecosystems such as perennial alpine meadow, perennial alpine steppe, temperate evergreen needleleaf trees, temperate deciduous trees, temperate shrub grassland, and barely vegetated desert. Perennial alpine meadow and steppe are the two dominant vegetation types on the heartland of the plateau. MODIS Leaf Area Index (LAI) ranges from 0 to 2 in most part of the plateau. With climate change, these ecosystems are expected to undergo alteration. This study uses a dynamic vegetation model - Lund-Potsdam-Jena (LPJ) to investigate the change of the barely vegetated area and other vegetation types caused by climate change during 1957-2015 on the Tibetan Plateau. Model simulated foliage projective coverage (FPC) and plant functional types (PFTs) are selected for the investigation. The model is evaluated first using both field surveyed land cover map and MODIS LAI images. Long term trends of vegetation FPC is examined. Decadal variations of vegetated and barely vegetated land are compared. The impacts of extreme precipitation, air temperature and CO2 on the expansion and contraction of barely vegetated and vegetated areas are shown. The study will identify the dominant climate factors in affecting the desert area in the region.

  17. A decadal satellite analysis of the origins and impacts of smoke in Colorado

    Directory of Open Access Journals (Sweden)

    M. Val Martin


    Full Text Available We analyze the record of aerosol optical depth (AOD measured by the MODerate resolution Imaging Spectroradiometer (MODIS aboard the Terra satellite in combination with surface PM2.5 to investigate the impact of fires on aerosol loading and air quality over Colorado from 2000 to 2012, and to evaluate the contribution of local versus transported smoke. Fire smoke contributed significantly to the AOD levels observed over Colorado. During the worst fire seasons of 2002 and 2012, average MODIS AOD over the Colorado Front Range corridor were 20–50% larger than the other 11 yr studied. Surface PM2.5 was also unusually elevated during fire events and concentrations were in many occasions above the daily National Ambient Air Quality Standard (35 μg m−3 and even reached locally unhealthy levels (> 100 μg m−3 over populated areas during the 2012 High Park fire and the 2002 Hayman fire. Over the 13 yr examined, long-range transport of smoke from northwestern US and even California (> 1500 km distance occurred often and affected AOD and surface PM2.5. During most of the transport events, MODIS AOD and surface PM2.5 were reasonable correlated (r2 = 0.2–0.9, indicating that smoke subsided into the Colorado boundary layer and reached surface levels. However, that is not always the case since at least one event of AOD enhancement was disconnected from the surface (r22.5 levels. Observed plume heights from the Multi-angle Imaging SpectroRadiometer (MISR satellite instrument and vertical aerosol profiles measured by the space-based Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP showed a complex vertical distribution of smoke emitted by the High Park fire in 2012. Smoke was detected from a range of 1.5 to 7.5 km altitude at the fire origin and from ground levels to 12.3 km altitude far away from the source. The variability of smoke altitude as well as the local meteorology were key in determining the aerosol loading and air quality over the

  18. Cenozoic incision history of the Little Colorado River and its role in carving Grand Canyon (United States)

    Karlstrom, K. E.


    Multi-stage incision/denudation history for the southwestern Colorado Plateau involved: carving of 70-30 Ma Laramide paleotopography controlled by strike valleys at the base of retreating cliffs, 25-15 Ma incision of an East Kaibab paleovalley that cut to about half the modern depth of eastern Grand Canyon, and 5-6 Ma integration of the Colorado River (CR) through Grand Canyon. A synthesis of Little Colorado River (LCR) incision history informs aspects of each episode. Refined evidence for the first two episodes is from new thermochronology modeling that shows post-Laramide NE cliff retreat and a 35-25 Ma LCR paleovalley that flowed NW across the Kaibab uplift. Next was 16-14 Ma playa/ marsh deposition of Lower Bidahochi Formation, 13-8 Ma non-deposition, and 6-8 fluvial upper Bidahochi Formation with base level defined by Hopi Buttes maars. Little denudation in the LCR valley from 16 to 6 Ma is documented by similar elevations of 16 and 6 Ma paleo baselevels. The third pulse of regional incision/denudation was associated with integration of the CR across the Vermillion Cliffs after 5-6 Ma. Earliest integration reoccupied the East Kaibab paleocanyon, inferred from thermochronology to have been at ~1500-1700 m elevation at 15 Ma. Topographically inverted dated basalt mesas in the LCR headwater region show steady incision of 43 m/Ma since 6 Ma. New 2 Ma sanidine ages for Crooked Ridge and Blue Point ash show ~100 m/Ma differential incision across the LCR knickpoint over the last ~ 2 Ma: ~400 m (~200 m/Ma) at the confluence, 400-500 m (200-250 m/Ma) at the projected confluence of Crooked Ridge and the LCR, 220 m (110 m/Ma) for topographically inverted basalt mesas in LCR tributaries in the central reaches, and 116-204 m (61-43 m/Ma) in the headwaters. Headwater uplift of the Rocky Mountains likely facilitated CR integration; post-2 Ma differential incision in the LCR may reflect a combination of regional mantle-driven epeirogenic uplift and additional mantle

  19. Drivers of annual to decadal streamflow variability in the lower Colorado River Basin (United States)

    Lambeth-Beagles, R. S.; Troch, P. A.


    The Colorado River is the main water supply to the southwest region. As demand reaches the limit of supply in the southwest it becomes increasingly important to understand the dynamics of streamflow in the Colorado River and in particular the tributaries to the lower Colorado River. Climate change may pose an additional threat to the already-scarce water supply in the southwest. Due to the narrowing margin for error, water managers are keen on extending their ability to predict streamflow volumes on a mid-range to decadal scale. Before a predictive streamflow model can be developed, an understanding of the physical drivers of annual to decadal streamflow variability in the lower Colorado River Basin is needed. This research addresses this need by applying multiple statistical methods to identify trends, patterns and relationships present in streamflow, precipitation and temperature over the past century in four contributing watersheds to the lower Colorado River. The four watersheds selected were the Paria, Little Colorado, Virgin/Muddy, and Bill Williams. Time series data over a common period from 1906-2007 for streamflow, precipitation and temperature were used for the initial analysis. Through statistical analysis the following questions were addressed: 1) are there observable trends and patterns in these variables during the past century and 2) if there are trends or patterns, how are they related to each other? The Mann-Kendall test was used to identify trends in the three variables. Assumptions regarding autocorrelation and persistence in the data were taken into consideration. Kendall’s tau-b test was used to establish association between any found trends in the data. Initial results suggest there are two primary processes occurring. First, statistical analysis reveals significant upward trends in temperatures and downward trends in streamflow. However, there appears to be no trend in precipitation data. These trends in streamflow and temperature speak to

  20. Simulating the potential effects of climate change in two Colorado basins and at two Colorado ski areas (United States)

    Battaglin, W.; Hay, L.; Markstrom, S.


    The mountainous areas of Colorado are used for tourism and recreation, and they provide water storage and supply for municipalities, industries, and agriculture. Recent studies suggest that water supply and tourist industries such as skiing are at risk from climate change. In this study, a distributed-parameter watershed model, the Precipitation-Runoff Modeling System (PRMS), is used to identify the potential effects of future climate on hydrologic conditions for two Colorado basins, the East River at Almont and the Yampa River at Steamboat Springs, and at the subbasin scale for two ski areas within those basins. Climate-change input files for PRMS were generated by modifying daily PRMS precipitation and temperature inputs with mean monthly climate-change fields of precipitation and temperature derived from five general circulation model (GCM) simulations using one current and three future carbon emission scenarios. All GCM simulations of mean daily minimum and maximum air temperature for the East and Yampa River basins indicate a relatively steady increase of up to several degrees Celsius from baseline conditions by 2094. GCM simulations of precipitation in the two basins indicate little change or trend in precipitation, but there is a large range associated with these projections. PRMS projections of basin mean daily streamflow vary by scenario but indicate a central tendency toward slight decreases, with a large range associated with these projections. Decreases in water content or changes in the spatial extent of snowpack in the East and Yampa River basins are important because of potential adverse effects on water supply and recreational activities. PRMS projections of each future scenario indicate a central tendency for decreases in basin mean snow-covered area and snowpack water equivalent, with the range in the projected decreases increasing with time. However, when examined on a monthly basis, the projected decreases are most dramatic during fall and

  1. Status, ecology, and conservation of the Himalayan griffon Gyps himalayensis (Aves, Accipitridae) in the Tibetan plateau. (United States)

    Lu, Xin; Ke, Dianhua; Zeng, Xianhai; Gong, Guohong; Ci, Ren


    The dramatic population crashes of 3 species of Gyps vulture have raised concerns about the status of their lesser-known congeners. Among these is the Himalayan griffon, G. himalayensis, an iconic vulture of the Tibetan plateau. The continued existence of this scavenger has not only ecological but also cultural implications because of their unique role in the centuries-old sky burial tradition that is followed by nearly 5 million Tibetan people. A lack of baseline information of the Himalayan griffon limits our ability to take conservation measures. The presented data, which were collected during 1996 and 2004 to 2007, indicate that this species is still widespread throughout the plateau and has not experienced a major population decline, likely as a result of protection by Tibetan Buddhism and limited disturbances from human activities largely due to the remoteness of the plateau. Both site and road counts showed that open meadow habitats had the highest griffon abundance, followed by alpine shrub and forest habitats. Estimates based on road transect counts showed that 229,339 Himalayan griffons (+/- 40,447) occupy the 2.5 million km2 Tibetan plateau. In contrast, the maximum carrying capacity of the plateau, on the basis of the total biomass of potential food resources, is 507,996 griffons, with meadow habitats accounting for about 76% of the total population. Griffons depend largely on livestock carcasses for food and forage in groups averaging 5.5 (range 1-100) individuals. Domestic yaks provide about 64% of the griffons' diet, while wild ungulates and human corpses provide 1% and 2%, respectively. Compared with its lowland congeners, this, the only high-elevation Gyps species, had both low population density and small group size, a likely response to the harsh environmental conditions. Although griffon abundance appears relatively stable in their fairly pristine environment, precautionary measures, including investigation of threats, monitoring of population

  2. 75 FR 59707 - Public Service Company of Colorado; Notice of Rate Election (United States)


    ... Energy Regulatory Commission Public Service Company of Colorado; Notice of Rate Election September 21, 2010. Take notice that on September 17, 2010, Public Service Company of Colorado (PSCo) filed a Rate... intrastate service on file with the Colorado Public Utilities Commission (Colorado PUC). Any person desiring...

  3. Gravitational salt tectonics above a rising basement plateau offshore Algeria (United States)

    Gaullier, Virginie; Vendeville, Bruno C.; Besème, Grégoire; Legoux, Gaetan; Déverchère, Jacques; Lymer, Gaël


    Seismic data (survey "MARADJA 1", 2003) offshore the Algerian coast have imaged an unexpected deformation pattern of the Messinian salt (Mobile Unit; MU) and its sedimentary overburden (Messinian Upper Unit and Plio-Quaternary) above an actively rising plateau in the subsalt basement. From a geodynamic point of view, the region is undergoing crustal convergence, as attested by the Boumerdes earthquake (2003, magnitude 6.8). The rise of this plateau, forming a 3D promontory restricted to the area offshore Algiers, is associated with that geodynamic setting. The seismic profiles show several subsalt thrusts (Domzig et al. 2006). The data provided additional information on the deformation of the Messinian mobile evaporitic unit and its Plio-Quaternary overburden. Margin-perpendicular profiles show mostly compressional features (anticlines and synclines) that had little activity during Messinian times, then grew more during Plio-Quaternary times. A few normal faults are also present, but are not accompanied by salt rise. By contrast, margin-parallel profiles clearly show that extensional, reactive salt diapiric ridges (symptomatic with their triangular shape in cross section) formed early, as early as the time of deposition of the Messinian Upper Unit, as recorded by fan-shaped strata. These ridges have recorded E-W, thin-skinned gravity gliding above the Messinian salt, as a response to the rise of the basement plateau. We tested this hypothesis using two analogue models, one where we assumed that the rise of the plateau started after Messinian times (initially tabular salt across the entire region), the second model assumed that the plateau had already risen partially as the Messininan Mobile Unit was deposited (salt initially thinner above the plateau than in the adjacent regions). In both experiments, the rise of the plateau generated preferential E-W extension above the salt, combined with N-S shortening. Extension was caused by gravity gliding of the salt from

  4. Stable isotope tracers of water vapor sources in the Atacama Desert, Northern Chile: a pilot study on the Chajnantor Plateau (United States)

    Samuels, K. E.; Galewsky, J.; Sharp, Z. D.; Rella, C.; Ward, D.


    Subtropical deserts form in response to the interaction of large-scale processes, including atmospheric circulation and oceanic currents, with local features like topography. The degree to which each of these factors controls desert formation and the anticipated impacts of variations in each as climate changes, however, are poorly understood. Stable isotope compositions of water vapor in desert air can help to distinguish between moisture sources and processes that control aridity. The Atacama Desert, located in northern Chile between latitudes 23S and 27S, provides a natural laboratory in which to test the degree to which water vapor isotopologues enable the distinction between processes that control humidity, including the Hadley Circulation, the cold Humboldt Current off the coast of Chile, and the orographic effect of the Andes, in this subtropical desert. Water vapor isotopologues and concentrations were measured in real time using a cavity-ringdown spectrometer deployed on the Chajnantor Plateau over a three-week period from mid-July early August 2010. The elevation of the Plateau, 5000 m amsl (~550 hPa), places it above the boundary layer, allowing the evaluation of the Rayleigh fractionation model from the coast inland. Values reported by the instrument were verified with air samples taken at the coast and the Plateau, which were analyzed on an MAT-252 mass spectrometer. Water vapor concentrations and δD values varied spatially and temporally. Water vapor concentrations on the Plateau ranged from 200 to 3664 ppmv with a mean value of 536 ppmv. In contrast, water vapor concentrations at the coast were approximately 10000 ppmv, and at Yungay, 60 km inland, water vapor concentrations ranged from 1300 to 2000 ppmv from morning to evening. δD values on the Plateau ranged from -526‰ to -100‰ with a mean value of 290‰ with enriched values correlated to periods with higher water vapor concentrations. There are no strong diurnal variations in water vapor

  5. Range expansion of the Mandarin Duck Aix galericulata (Aves: Anseriformes: Anatidae to the Lena River catchment, Siberia

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    Victor G. Degtyarev


    Full Text Available Recently the Mandarin Duck Aix galericulata was observed beyond its known range of 60°N as pairs, individuals and small flocks along the upper and middle reaches of the Aldan River and its tributaries from spring to late autumn. Pairs and solitary males (all probably vagrant were also recorded as far North as 61°-63°N. This species encounters appropriate habitats within the  Prilenskoe Plateau,  the Aldanskoe High Plateau, and the Yudomo-Mayiskoe High Plateau  in the Lena River catchment, and can potentially breed within the extended range if the number in the Amur River basin increases.

  6. Spontaneous collapse of the tibial plateau: radiological staging

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    Carpintero, P.; Leon, F.; Zafra, M. [University Hospital ' ' Reina Sofia' ' , Orthopaedic Department, Cordoba (Spain); Montero, R.; Carreto, A. [University Hospital ' ' Reina Sofia' ' , Radiology Department, Cordoba (Spain)


    This paper proposes a radiological staging system for necrosis of the tibial plateau, similar to those already developed for the hip and the medial femoral condyle. We retrospectively studied the clinical case histories and radiographic findings of 14 patients (15 affected knees) with histologically proven osteonecrosis of the tibial plateau. Stage I was marked by normal radiograph, but increased uptake in bone scan and subchondral areas of abnormal marrow signal intensity in magnetic resonance imaging (MRI), as reported in other osteonecrosis sites. Stage II was characterised by cystic and sclerotic changes, and stage III fracture of the medial rim of the medial tibial plateau and tibial plateau collapse were present. Stage IV was marked by joint narrowing. These changes appeared earlier and were more pronounced when there was genu varum/valgum or involvement of the lateral tibial plateau. The radiological evolution of the disease appears to follow a four-stage course over a period of roughly one year from the onset of symptoms. (orig.)

  7. Verçenik Plateau Alternative Tourism and Recreational Activities

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    Full Text Available In the last century working life become easier and result of this increased people free time, after that interest of tourism activities wide spread all over. Plateau tourism or highland places are not first choices of the tourism activities but plateau rec reation will give an application for potential activity place. Turkey have unmatched nature and rich environmental resources will able to give any kind of tourism activities. In that context city of Rize took place in Black Sea region with different capabi lities, one of the source areas that make up tourism and recreational activities. This research intended for Vercenik Plateau take place 60 km away from Camlihemsin district center and will determine potential tourism and recreational application. Research is based on field observation and studies. This information obtained as a result ofthis evaluationbeing associated toliterature data and that information determined which exercise can be done in the field. Vercenik Plateau; with pristine environment and ru ral locations, the fresh water supplies, unique flora for city of Rize has high recreational capacities.As a result of study; Vercenik Plateau has natural features with the great potential of the alternative tourism as it is suitable for areas but not asse ss enough potential tourism and recreational activities without prior review has been observed.

  8. Seismic wave speed structure of the Ontong Java Plateau (United States)

    Covellone, Brian M.; Savage, Brian; Shen, Yang


    The Ontong Java Plateau (OJP) represents the result of a significant event in the Earth's geologic history. Limited geophysical and geochemical data, as well as the plateau's relative isolation in the Pacific ocean, have made interpretation of the modern day geologic structure and its 120 Ma formation history difficult. Here we present the highest resolution image to date of the wave speed structure of the OJP region. We use a data set that combines Rayleigh waves extracted from both ambient noise and earthquake waveforms and an iterative finite-frequency tomography methodology. The combination of datasets allow us to best exploit the limited station distribution in the Pacific and image wave speed structures between 35 km and 300 km into the Earth. We image a region of fast shear wave speeds, greater than 4.75 km/s, that extends to greater than 100 km beneath the plateau. The wave speeds are similar to as observed in cratonic environments and are consistent with a compositional anomaly that resulted from the residuum of eclogite entrainment during the plateau's formation. The combination of our imaged wave speed structure and previous geochemical work suggest that a surfacing plume head entrained eclogite from the deep mantle and accounts for the anomalous buoyancy characteristics of the plateau and observed fast wave speeds.

  9. Fraturas do planalto tibial Tibial plateau fractures

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    Maurício Kfuri Júnior


    Full Text Available As fraturas do planalto tibial são lesões articulares cujos princípios de tratamento envolvem a redução anatômica da superfície articular e a restauração funcional do eixo mecânico do membro inferior. Contribuem para a tomada de decisões no tratamento dessas fraturas o perfil do paciente, as condições do envelope de tecidos moles, a existência de outros traumatismos associados e a infraestrutura disponível para abordagens cirúrgicas. Para as fraturas de alta energia, o tratamento estagiado, seguindo o princípio do controle de danos, tem como prioridade a manutenção do alinhamento do membro enquanto se aguarda a resolução das más condições de tecidos moles. Já nos traumas de baixa energia, desde que os tecidos moles não sejam um fator adverso, o tratamento deve ser realizado em tempo único, com osteossíntese definitiva. Fixação estável e movimento precoce são variáveis diretamente relacionadas com os melhores prognósticos. Desenvolvimentos recentes, como os implantes com estabilidade angular, substitutos ósseos e imagens tridimensionais para controle intraoperatório, deverão contribuir para cirurgias menos invasivas e melhores resultados.Tibial plateau fractures are joint lesions that require anatomical reduction of joint surface and functional restoration of mechanical axis of a lower limb. Patient profile, soft tissue conditions, presence of associated injuries and the available infrastructure for the treatment all contribute to the decision making about the best treatment for these fractures. High-energy fractures are usually approached in a staged manner respecting the principle of damage control, and are primarily targeted to maintain limb alignment while the resolution unfavorable soft tissue conditions is pending. Low-energy trauma can be managed on a single-stage basis, provided soft tissues are not an adverse factor, with open reduction and internal f-ixation. Stable fixation and early painless joint

  10. Water soluble organic aerosols in the Colorado Rocky Mountains, USA: composition, sources and optical properties (United States)

    Xie, Mingjie; Mladenov, Natalie; Williams, Mark W.; Neff, Jason C.; Wasswa, Joseph; Hannigan, Michael P.


    Atmospheric aerosols have been shown to be an important input of organic carbon and nutrients to alpine watersheds and influence biogeochemical processes in these remote settings. For many remote, high elevation watersheds, direct evidence of the sources of water soluble organic aerosols and their chemical and optical characteristics is lacking. Here, we show that the concentration of water soluble organic carbon (WSOC) in the total suspended particulate (TSP) load at a high elevation site in the Colorado Rocky Mountains was strongly correlated with UV absorbance at 254 nm (Abs254, r = 0.88 p 90% of OC on average. According to source apportionment analysis, biomass burning had the highest contribution (50.3%) to average WSOC concentration; SOA formation and motor vehicle emissions dominated the contribution to WSOC in the summer. The source apportionment and backward trajectory analysis results supported the notion that both wildfire and Colorado Front Range pollution sources contribute to the summertime OC peaks observed in wet deposition at high elevation sites in the Colorado Rocky Mountains. These findings have important implications for water quality in remote, high-elevation, mountain catchments considered to be our pristine reference sites.

  11. Transport of pollutants from cow feedlots in eastern Colorado into Rocky Mountain alpine lakes (United States)

    Pina, A.; Denning, S.; Schumacher, R. S.


    Concentrated Animal Feeding Operations (CAFOs), also called factory farms, are known for raising tens of millions head of livestock including cows (beef and dairy), swine, and poultry. With as many as 250 head of cattle per acre, a United States Department of Agriculture's (USDA) Agricultural Research Service (ARS) report showed beef cattle from CAFOs in the United States produce as much as 24.1 million tons of manure annually. Gases released from cow manure include methane (CH4), nitrous oxide (N2O), hydrogen sulfide (H2S), and ammonia (NH3). During boreal summers Colorado experiences fewer synoptic weather systems, allowing the diurnal cycle to exert greater control of meteorological events along the mountain-plains interface. Anabatic, or upslope winds induced by the diurnal cycle, contribute largely to the transport of gases and particulates from feedlots in eastern Colorado into the Rocky Mountains, presenting a potential harm to natural alpine ecosystems. This study focuses on locating the source of transport of gases from feedlots along the eastern Front Range of Colorado into alpine lakes of the Rocky Mountains. Source regions are approximated using backward time simulation of a Lagrangian Transport model.

  12. Predictors of osteoarthritis following operative treatment of medial tibial plateau fractures. (United States)

    Parkkinen, Markus; Lindahl, Jan; Mäkinen, Tatu J; Koskinen, Seppo K; Mustonen, Antti; Madanat, Rami


    To determine factors influencing the development of posttraumatic osteoarthritis (OA) following medial tibial plateau fractures and to evaluate concomitant injuries associated with these fractures. A chart review of patients with operatively treated medial tibial plateau fractures admitted to our Level I trauma centre from 2002 to 2008 was performed. Of 63 patients, 41 participated in a clinical and radiographic examination. The mean age was 47 years (range 16-78) and the mean follow-up time was 7.6 (range 4.7-11.7) years. All patients had preoperative computed tomography (CT) scans and postoperative radiographs. At the end of follow-up, standing radiographs, mechanical axis, and CT scans were evaluated. Of the 41 patients, 24 had no or mild (Kellgren-Lawrence grade 0-2) OA and 17 had severe (grade 3-4) OA. Initial articular depression measured from preoperative CT scans was a significant predictor of OA (median 1.8mm vs 4.5mm, p=0.009). Fracture line extension to the lateral plateau (p=0.68) or fracture comminution (p=0.21) had no effect on the development of posttraumatic OA, nor did articular depression at the end of follow-up (p=0.68) measured from CT scans. Mechanical axis >4° of varus and ≥2mm articular depression or step-off were associated with worse WOMAC pain scores, but did not affect other functional outcome scores. Six patients (10%) had permanent peroneal nerve dysfunction. Ten patients (16%) required LCL reconstruction and nine (14%) ACL avulsions were treated at the time of fracture stabilisation. The amount of articular depression measured from preoperative CT scans seems to predict the development of posttraumatic OA, probably reflecting the severity of chondral injury at the time of fracture. Restoration of mechanical axis and articular congruence are important in achieving a good clinical outcome. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Fukushima nuclear accident recorded in Tibetan Plateau snow pits.

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    Ninglian Wang

    Full Text Available The β radioactivity of snow-pit samples collected in the spring of 2011 on four Tibetan Plateau glaciers demonstrate a remarkable peak in each snow pit profile, with peaks about ten to tens of times higher than background levels. The timing of these peaks suggests that the high radioactivity resulted from the Fukushima nuclear accident that occurred on March 11, 2011 in eastern Japan. Fallout monitoring studies demonstrate that this radioactive material was transported by the westerlies across the middle latitudes of the Northern Hemisphere. The depth of the peak β radioactivity in each snow pit compared with observational precipitation records, suggests that the radioactive fallout reached the Tibetan Plateau and was deposited on glacier surfaces in late March 2011, or approximately 20 days after the nuclear accident. The radioactive fallout existed in the atmosphere over the Tibetan Plateau for about one month.

  14. An avifaunal case study of a plateau from Goa, India: an eye opener for conservation of plateau ecosystems

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    Minal Desai


    Full Text Available The lateritic plateaux typical of the midlands between the Western Ghats and the coastal plains of the Arabian Sea are known to be a unique ecosystem with a sizeable endemic flora. However, there is a total lack of studies on the faunal diversity of these plateaux, which are currently experiencing enormous anthropogenic pressures. We conducted a year-long study on the avifauna of the Taleigao Plateau, Goa. The Taleigao Plateau harbours 114 species of birds, accounting for 37% of the avifaunal diversity of the state. The resident bird population did not vary significantly through the seasons. Among the migrant birds, Rosy Starling Sturnus roseus was particularly partial to the plateau. Besides, five species of larks, grassland specialists were also recorded on the plateau. However, the absence of forest birds like the Malabar Pied Hornbill and the Indian Grey Hornbill (recorded earlier and the predominance of habitat generalists like the House Crow and the Jungle Myna seemed to be the offshoot of heavy anthropogenic pressures on the plateau. It is recommended that at least some plateaux in the belt deserve to be protected from the impact of unsustainable developmental process

  15. The impacts of the summer plateau monsoon over the Tibetan Plateau on the rainfall in the Tarim Basin, China (United States)

    Zhao, Yong; Huang, Anning; Zhou, Yang; Yang, Qing


    The impacts of the summer plateau monsoon (PM) over the Tibetan Plateau on summer rainfall over the Tarim Basin in northwest China are investigated, based on the observed rainfall data at 34 stations and the NCEP/NCAR reanalysis data during 1961 to 2007. Results showed that the PM is well correlated to the summer rainfall over the Tarim Basin. Process analysis shows that strong PM corresponds to an anomalous cyclone over the Tibetan Plateau in the middle troposphere and an anomalous anticyclone in the upper troposphere over northwest part of Tibetan Plateau. They result in cold air moving from high latitudes into Central Asia over the western part of Tibetan Plateau. The concurrences of the cooling in the middle-upper troposphere over Central Asia leads to an anomalous cyclone over Central Asia at 500 hPa and the anomalous descending motions prevailing over the cooling region. Associated with this anomaly, there are enhanced southerly winds and corresponding ascending motion over the Tarim Basin located in the east of the cooling region. These processes lead to more summer rainfall over the Tarim Basin.

  16. Focal Mechanism Determination and Propagation Characteristics of High-frequency S-waves on the Tibetan Plateau, (United States)


    However, at frequencies above 3 Hz, the amplitudes vary strongly from station to station (Figure 3b). For example BUDO and AMDO are at similar distance...ranges, but BUDO is located in the north-central plateau where high attenuation of high-frequency Sn were observed (Ni and Barazangi, 1983...Correspondingly, the high frequency amplitude at BUDO are much smaller than at AMDO. Same is true for station TUNL compared with SANG. To characterize the

  17. Soil Moisture and Temperature Measuring Networks in the Tibetan Plateau and Their Hydrological Applications (United States)

    Yang, Kun; Chen, Yingying; Qin, Jun; Lu, Hui


    Multi-sphere interactions over the Tibetan Plateau directly impact its surrounding climate and environment at a variety of spatiotemporal scales. Remote sensing and modeling are expected to provide hydro-meteorological data needed for these process studies, but in situ observations are required to support their calibration and validation. For this purpose, we have established two networks on the Tibetan Plateau to measure densely two state variables (soil moisture and temperature) and four soil depths (0 5, 10, 20, and 40 cm). The experimental area is characterized by low biomass, high soil moisture dynamic range, and typical freeze-thaw cycle. As auxiliary parameters of these networks, soil texture and soil organic carbon content are measured at each station to support further studies. In order to guarantee continuous and high-quality data, tremendous efforts have been made to protect the data logger from soil water intrusion, to calibrate soil moisture sensors, and to upscale the point measurements. One soil moisture network is located in a semi-humid area in central Tibetan Plateau (Naqu), which consists of 56 stations with their elevation varying over 4470 4950 m and covers three spatial scales (1.0, 0.3, 0.1 degree). The other is located in a semi-arid area in southern Tibetan Plateau (Pali), which consists of 25 stations and covers an area of 0.25 degree. The spatiotemporal characteristics of the former network were analyzed, and a new spatial upscaling method was developed to obtain the regional mean soil moisture truth from the point measurements. Our networks meet the requirement for evaluating a variety of soil moisture products, developing new algorithms, and analyzing soil moisture scaling. Three applications with the network data are presented in this paper. 1. Evaluation of Current remote sensing and LSM products. The in situ data have been used to evaluate AMSR-E, AMSR2, SMOS and SMAP products and four modeled outputs by the Global Land Data

  18. An ecosystem services framework for multidisciplinary research in the Colorado River headwaters (United States)

    Semmens, D.J.; Briggs, J.S.; Martin, D.A.


    A rapidly spreading Mountain Pine Beetle epidemic is killing lodgepole pine forest in the Rocky Mountains, causing landscape change on a massive scale. Approximately 1.5 million acres of lodgepoledominated forest is already dead or dying in Colorado, the infestation is still spreading rapidly, and it is expected that in excess of 90 percent of all lodgepole forest will ultimately be killed. Drought conditions combined with dramatically reduced foliar moisture content due to stress or mortality from Mountain Pine Beetle have combined to elevate the probability of large fires throughout the Colorado River headwaters. Large numbers of homes in the wildland-urban interface, an extensive water supply infrastructure, and a local economy driven largely by recreational tourism make the potential costs associated with such a fire very large. Any assessment of fire risk for strategic planning of pre-fire management actions must consider these and a host of other important socioeconomic benefits derived from the Rocky Mountain Lodgepole Pine Forest ecosystem. This paper presents a plan to focus U.S. Geological Survey (USGS) multidisciplinary fire/beetle-related research in the Colorado River headwaters within a framework that integrates a wide variety of discipline-specific research to assess and value the full range of ecosystem services provided by the Rocky Mountain Lodgepole Pine Forest ecosystem. Baseline, unburned conditions will be compared with a hypothetical, fully burned scenario to (a) identify where services would be most severely impacted, and (b) quantify potential economic losses. Collaboration with the U.S. Forest Service will further yield a distributed model of fire probability that can be used in combination with the ecosystem service valuation to develop comprehensive, distributed maps of fire risk in the Upper Colorado River Basin. These maps will be intended for use by stakeholders as a strategic planning tool for pre-fire management activities and can

  19. Understanding the formation of the Ontong Java Plateau through joint ambient noise earthquake tomography and laboratory modeling (United States)

    Covellone, B. M.; Szwaja, S.; Savage, B. K.; Shen, Y.; Kincaid, C. R.


    Current knowledge of the Ontong Java Plateau (OJP) comes from a broad range of research disciplines. Despite decades of work, numerous hypotheses on the origin of the OJP do not fully address all of the geophysical and geochemical observations. A more complete image of the current lower crust and upper mantle seismic structure beneath the plateau will provide a link between the plateau's 120 Ma complex history and it's formation. We investigate the anomalous wave speed structure underlying the OJP using an iterative, full-waveform, joint ambient noise and earthquake tomography approach. A 3-dimensional wave speed model is determined from ambient noise data at periods between 25 and 200 seconds. Data from over 100 earthquakes, recorded between 1990 and 2012, are then added to the inversion to improve data coverage and model resolution. The combination of datasets allows us to best exploit the limited station distribution in the Pacific, resulting in resolution better than 5-degrees beneath the plateau and extending to depths greater than 350 km. To improve our sense of expected deformation patterns for sub-plateau mantle through geologic time, a set of laboratory models were run where OJP residuum viscosity is changed relative to the ambient fluid. Models focus on the interaction between OJP residuum and the rollback-driven flow associated with passage of the Tonga subduction system to the south. Model results show dramatic thinning and extraction of the southern portion of sub-OJP fluid due to subduction induced torroidal flows. Significant distortion of the sub-OJP material over roughly the last 40 Ma is predicted in cases where residuum is either stronger or weaker than ambient fluid. The results of this work confirm an anomalously slow mantle beneath the OJP extending to depths greater than 300 km and provide high-resolution images constraining the magnitude and dimensions of wave speed anomalies that can be used to determine thermal and compositional variations

  20. Reduced convergence within the Tibetan Plateau by 26 Ma? (United States)

    Meng, Jun; Coe, Robert S.; Wang, Chengshan; Gilder, Stuart A.; Zhao, Xixi; Liu, Hao; Li, Yalin; Ma, Pengfei; Shi, Kai; Li, Shuai


    Understanding the dynamics of double-thickening and uplifting of the Tibetan crust requires constraints on the magnitude and timing of crustal shortening. New elongation/inclination (E/I)-corrected paleomagnetic data from 26-22 Ma sediments indicate that the latitude of southern Tibet in the early Miocene was 31.1/-6.8/+5.2°N, not significantly different from today. This implies that the southern margin of Asia, which was at 21-24°N latitude from the Late Cretaceous to the early Eocene, advanced 8-10° northward between the early Eocene and the latest Oligocene. Our results therefore suggest that at least 900-1100 km of continental shortening and significant regional uplift of the plateau occurred between the early Eocene and late Oligocene. Our results suggest that N-S intra-Asian convergence was considerably reduced around 26 Ma, corresponding to a transition from compression to extension within the Tibetan Plateau.type="synopsis">type="main">Plain Language SummaryTwo critical questions involving the geodynamic evolution of the Tibetan plateau are (i) when did a compression-dominated tectonic regime change to an extension-dominated tectonic regime on the plateau and (ii) how does this timing correlate with double thickening of the crust? Here we provide paleomagnetic evidence for the timing, magnitude, and partitioning of intra-Asian convergence. Our results imply a first-order constraint of 900-1100 km north-south shortening concentrated within the interval from 53 to 26 Ma. This suggests that a fundamental change at 26 Ma occurred in the geodynamics of the Tibetan Plateau marked by a reduction in large-scale convergence and compressive deformation. The implication is that significant regional uplift of the proto-Tibetan Plateau occurred within the 55-26 Ma interval. The paleolatitude, paleoclimate, and topography of south central Tibet seen at present were likely established around 26 Ma.

  1. Transport in the plateau regime in a tokamak pedestal (United States)

    Seol, J.; Shaing, K. C.


    In a tokamak H-mode, a strong E × B flow shear is generated during the L-H transition. Turbulence in a pedestal is suppressed significantly by this E × B flow shear. In this case, neoclassical transport may become important. The neoclassical fluxes are calculated in the plateau regime with the parallel plasma flow using their kinetic definitions. In an axisymmetric tokamak, the neoclassical particles fluxes can be decomposed into the banana-plateau flux and the Pfirsch-Schlüter flux. The banana-plateau particle flux is driven by the parallel viscous force and the Pfirsch-Schlüter flux by the poloidal variation of the friction force. The combined quantity of the radial electric field and the parallel flow is determined by the flux surface averaged parallel momentum balance equation rather than requiring the ambipolarity of the total particle fluxes. In this process, the Pfirsch-Schlüter flux does not appear in the flux surface averaged parallel momentum equation. Only the banana-plateau flux is used to determine the parallel flow in the form of the flux surface averaged parallel viscosity. The heat flux, obtained using the solution of the parallel momentum balance equation, decreases exponentially in the presence of sonic Mp without any enhancement over that in the standard neoclassical theory. Here, Mp is a combination of the poloidal E × B flow and the parallel mass flow. The neoclassical bootstrap current in the plateau regime is presented. It indicates that the neoclassical bootstrap current also is related only to the banana-plateau fluxes. Finally, transport fluxes are calculated when Mp is large enough to make the parallel electron viscosity comparable with the parallel ion viscosity. It is found that the bootstrap current has a finite value regardless of the magnitude of Mp.

  2. Internal Plateau in Short GRBs and Quark Stars (United States)

    Li, Ang

    I summarize our recent calculations on quark stars (QSs), for the purpose of explaining some short gamma-ray bursts characterized by internal plateau in their early X-ray afterglow. According to the present plateau sample, the QS central engine model is demonstrated to more preferred than the original neutron star (NS) one. New QS equation of states (PMQS1, PMQS2, PMQS3) are then proposed, respecting fully the observed burst data and the mass distribution of the Galactic NS-NS systems.

  3. Seismology Across the Northeastern Edge of the Tibetan Plateau (United States)

    Zhao, W.; Brown, L.; Wu, Z.; Klemperer, S. L.; Shi, D.; Mechie, J.; Su, H.; Tilmann, F.; Karplus, M. S.; Makovsky, Y.


    On 12 May, a great earthquake (Ms = 8.0) on the Longmenshan thrust fault rumbled through China's Sichuan province, killing more than 69,000 people and injuring 374,000. The Longmenshan thrust is part of the eastern border of the Tibetan Plateau, but it is not the plateau's only restless margin. An even larger earthquake (Ms = 8.1) on the Kunlun fault shook northeastern Tibet in 2001, fortunately in a sparsely populated area. These massive quakes underscore the importance of understanding the tectonic response of Asia to collision by India.

  4. Fractional Quantum Hall Plateau Transitions and Composite Fermi Liquids (United States)

    Cho, Gil Young; Moon, Eun-Gook; Fradkin, Eduardo

    We will investigate relationship between the fractional quantum Hall plateau transition from Laughlin state at ν =1/2 n + 1 to a trivial insulator, and composite Fermi liquid at ν =1/2 (2 n + 1) . We use the recently-developed quantum field theoretic technique, 3d dualities, in combinations with the coupled-wire descriptions for quantum Hall states. We will show that we can also access various other phases, including non-abelian paired states at ν =1/2 (2 n + 1) , from the plateau transition. This work is supported by the Brain Korea 21 PLUS Project of Korea Government and KAIST start-up funding (GYC & EGM).

  5. Conifer health classification for Colorado, 2008 (United States)

    Cole, Christopher J.; Noble, Suzanne M.; Blauer, Steven L.; Friesen, Beverly A.; Curry, Stacy E.; Bauer, Mark A.


    Colorado has undergone substantial changes in forests due to urbanization, wildfires, insect-caused tree mortality, and other human and environmental factors. The U.S. Geological Survey Rocky Mountain Geographic Science Center evaluated and developed a methodology for applying remotely-sensed imagery for assessing conifer health in Colorado. Two classes were identified for the purposes of this study: healthy and unhealthy (for example, an area the size of a 30- x 30-m pixel with 20 percent or greater visibly dead trees was defined as ?unhealthy?). Medium-resolution Landsat 5 Thematic Mapper imagery were collected. The normalized, reflectance-converted, cloud-filled Landsat scenes were merged to form a statewide image mosaic, and a Normalized Difference Vegetation Index (NDVI) and Renormalized Difference Infrared Index (RDII) were derived. A supervised maximum likelihood classification was done using the Landsat multispectral bands, the NDVI, the RDII, and 30-m U.S. Geological Survey National Elevation Dataset (NED). The classification was constrained to pixels identified in the updated landcover dataset as coniferous or mixed coniferous/deciduous vegetation. The statewide results were merged with a separate health assessment of Grand County, Colo., produced in late 2008. Sampling and validation was done by collecting field data and high-resolution imagery. The 86 percent overall classification accuracy attained in this study suggests that the data and methods used successfully characterized conifer conditions within Colorado. Although forest conditions for Lodgepole Pine (Pinus contorta) are easily characterized, classification uncertainty exists between healthy/unhealthy Ponderosa Pine (Pinus ponderosa), Pi?on (Pinus edulis), and Juniper (Juniperus sp.) vegetation. Some underestimation of conifer mortality in Summit County is likely, where recent (2008) cloud-free imagery was unavailable. These classification uncertainties are primarily due to the spatial and

  6. Flooding in the South Platte River and Fountain Creek Basins in eastern Colorado, September 9–18, 2013 (United States)

    Kimbrough, Robert A.; Holmes, Robert R.


    On September 9, 2013, rain began to fall in eastern Colorado as a large low-pressure system pulled plumes of tropical moisture northward from the Pacific Ocean and the Gulf of Mexico. By September 16, 2013, as much as 12 to 20 inches of rain had fallen in the foothills of the Front Range of the Southern Rocky Mountains and adjacent plains near Colorado Springs, Colorado, north to the Colorado-Wyoming border. The rain caused major flooding during September 9–18, 2013, in a large part of the South Platte River Basin and in the Fountain Creek Basin. The floods resulted in several fatalities, more than 31,000 damaged or destroyed structures, and an estimated 3 billion dollars in damages. The U.S. Geological Survey (USGS) documented peak stage, streamflow, or both from the flood event for 80 sites located on selected rivers and streams in the South Platte River and Fountain Creek Basins and on the Platte River in Nebraska. The majority of flood-peak streamflows occurred on September 12 or 13, 2013, coinciding with the period of maximum rainfall. The flood resulted in new record peak streamflows at 17 streamgages having at least 10 years of record; 13 in the South Platte River Basin and 4 in the Fountain Creek Basin.

  7. Determination of selenium in fish from designated critical habitat in the Gunnison River, Colorado, March through October, 2012 (United States)

    May, Thomas W.; Walther, Michael J.


    This report presents results for the summer 2012 sam-pling of muscle plugs from common carp (Cyprinus carpio), bonytail chub (Gila elegans), Colorado pikeminnow (Ptycho-cheilus lucius), and razorback suckers (Xyrauchen texanus) inhabiting critical habitat in the Gunnison River in western Colorado. Total selenium in fish muscle plugs was determinedby instrumental neutron activation analysis. Total selenium concentrations (range and mean ± standard deviation) in micrograms per gram dry weight were 6.0 to 10.7, 8.8 ± 1.3 for common carp; 2.9 to 8.7, 5.6 ± 2.4 for Colorado pikemin-now; and 1.4 to 7.3, 3.4 ± 2.7 for razorback sucker. The selenium concentration for one bonytail chub sample was 0.8 micrograms per gram dry weight. Selenium concentrations in muscle plugs from 1 Colorado pikeminnow and 12 common carp exceeded the 8 micrograms per gram dry weight toxicity guideline for selenium in fish muscle tissue.

  8. Prediction of suspended-sediment concentrations at selected sites in the Fountain Creek watershed, Colorado, 2008-09 (United States)

    Stogner, Sr., Robert W.; Nelson, Jonathan M.; McDonald, Richard R.; Kinzel, Paul J.; Mau, David P.


    In 2008, the U.S. Geological Survey (USGS), in cooperation with Pikes Peak Area Council of Governments, Colorado Water Conservation Board, Colorado Springs City Engineering, and the Lower Arkansas Valley Water Conservancy District, began a small-scale pilot study to evaluate the effectiveness of the use of a computational model of streamflow and suspended-sediment transport for predicting suspended-sediment concentrations and loads in the Fountain Creek watershed in Colorado. Increased erosion and sedimentation damage have been identified by the Fountain Creek Watershed Plan as key problems within the watershed. A recommendation in the Fountain Creek Watershed plan for management of the basin is to establish measurable criteria to determine if progress in reducing erosion and sedimentation damage is being made. The major objective of this study was to test a computational method to predict local suspended-sediment loads at two sites with different geomorphic characteristics in order to evaluate the feasibility of using such an approach to predict local suspended-sediment loads throughout the entire watershed. Detailed topographic surveys, particle-size data, and suspended-sediment samples were collected at two gaged sites: Monument Creek above Woodmen Road at Colorado Springs, Colorado (USGS gage 07103970), and Sand Creek above mouth at Colorado Springs, Colorado (USGS gage 07105600). These data were used to construct three-dimensional computational models of relatively short channel reaches at each site. The streamflow component of these models predicted a spatially distributed field of water-surface elevation, water velocity, and bed shear stress for a range of stream discharges. Using the model predictions, along with measured particle sizes, the sediment-transport component of the model predicted the suspended-sediment concentration throughout the reach of interest. These computed concentrations were used with predicted flow patterns and channel morphology to

  9. Probability and volume of potential postwildfire debris flows in the 2012 Waldo Canyon Burn Area near Colorado Springs, Colorado (United States)

    Verdin, Kristine L.; Dupree, Jean A.; Elliott, John G.


    This report presents a preliminary emergency assessment of the debris-flow hazards from drainage basins burned by the 2012 Waldo Canyon fire near Colorado Springs in El Paso County, Colorado. Empirical models derived from statistical evaluation of data collected from recently burned basins throughout the intermountain western United States were used to estimate the probability of debris-flow occurrence and potential volume of debris flows along the drainage network of the burned area and to estimate the same for 22 selected drainage basins along U.S. Highway 24 and the perimeter of the burned area. Input data for the models included topographic parameters, soil characteristics, burn severity, and rainfall totals and intensities for a (1) 2-year-recurrence, 1-hour-duration rainfall, referred to as a 2-year storm (29 millimeters); (2) 10-year-recurrence, 1-hour-duration rainfall, referred to as a 10-year storm (42 millimeters); and (3) 25-year-recurrence, 1-hour-duration rainfall, referred to as a 25-year storm (48 millimeters). Estimated debris-flow probabilities at the pour points of the the drainage basins of interest ranged from less than 1 to 54 percent in response to the 2-year storm; from less than 1 to 74 percent in response to the 10-year storm; and from less than 1 to 82 percent in response to the 25-year storm. Basins and drainage networks with the highest probabilities tended to be those on the southern and southeastern edge of the burn area where soils have relatively high clay contents and gradients are steep. Nine of the 22 drainage basins of interest have greater than a 40-percent probability of producing a debris flow in response to the 10-year storm. Estimated debris-flow volumes for all rainfalls modeled range from a low of 1,500 cubic meters to a high of greater than 100,000 cubic meters. Estimated debris-flow volumes increase with basin size and distance along the drainage network, but some smaller drainages were also predicted to produce

  10. Environmental geology of the Summitville mine, Colorado (United States)

    Gray, John E.; Coolbaugh, Mark F.; Plumlee, Geoffrey S.; Atkinson, William W.


    Although altered and mineralized rocks at Summitville mine in Colorado contain minimal amount of sulfide minerals, acid mine problems existed primarily because of the pervasive alteration of the surrounding rocks, through hydrothermal process, to highly siliceous and argillized rocks that are incapable of buffering acidic waters during weathering. The problems are compounded by the continued exposure of altered and mineralized rocks in open pit, heap leach pad and waste piles to oxygenated waters. Inadequate subsurface structural control and underground mine workings also greatly affect water quality and the location of acid mine drainage output. It is expected that with these initial results, geological studies on constrained acid-generation from ore and altered rocks will be pursued.

  11. An overview of Colorado tick fever. (United States)

    Emmons, R W


    Certain features of Colorado tick fever (CTF) virus and the disease it causes may be relevant to studies on bluetongue virus (BTV), or other orbiviruses. Rapid and easy detection of viral antigen in infected tissues and peripheral blood cells by immunofluorescence staining facilitate diagnosis of the disease. The prolonged (3-4 months) viremia is due to persistent intracellular infection, particularly of erythrocytes, in which the virus is protected from antibody or other host defense mechanisms. This results in more efficient maintenance of the virus cycle in nature, but might lead to adverse effects in the human host. Clues to understanding chronic viral infections or viral immunosuppression might be gained by further research on CTF and other orbiviruses.

  12. US hydropower resource assessment for Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Francfort, J.E.


    The US Department of Energy is developing an estimate of the hydropower development potential in this country. Hydropower Evaluation Software (HES) is a computer model that was developed by the Idaho National Engineering Laboratory for this purpose. HES measures the potential hydropower resources available in the United States, using uniform criteria for measurement. The software was developed and tested using hydropower information and data provided by the Southwestern Power Administration. It is a dBASE, menu-driven software application. HES allows the personal computer user to assign environmental attributes to potential hydropower sites, calculate development suitability factors for each site based on the environmental attributes present, and generate reports based on these suitability factors. This report details the resource assessment results for the State of Colorado.

  13. Ponnequin Wind Energy Project Weld County, Colorado

    Energy Technology Data Exchange (ETDEWEB)



    The purpose of this environmental assessment (EA) is to provide the U.S. Department of Energy (DOE) and the public with information on potential environmental impacts associated with the development of the Ponnequin Wind Energy Project in Colorado. This EA and public comments received on it will be used in DOE`s deliberations on whether to release funding for the project. This document provides a detailed description of the proposed project and an assessment of potential impacts associated with its construction and operations. Resources and conditions considered in the analysis include streams; wetlands; floodplains; water quality; soils; vegetation; air quality; socioeconomic conditions; energy resources; noise; transportation; cultural resources; visual and land use resources; public health and safety; wildlife; threatened, endangered, and candidate species; and cumulative impacts. The analysis found that the project would have minimal impacts on these resources and conditions, and would not create impacts that exceed the significance criteria defined in this document. 90 refs., 5 figs.

  14. The Federal Administrative Maximum Penitentiary, Florence, Colorado. (United States)

    Coid, J W


    Policies for the control of dangerous and disruptive prisoners in European penal institutions depend upon social regimes managed by prison staff. These contrast with certain US regimes where there is increasing use of the incapacitation approach. This paper describes an incapacitation regime developed in the US Federal Administrative Maximum Penitentiary (ADX), Florence, Colorado which is complemented by an architectural design minimizing contact between prisoners and staff. This is reported to have been highly effective in controlling violent and predatory behaviour, escapes, drug-taking, and the influence of members of criminal gangs and notorious prisoners transferred to the ADX. Despite a shift of policy from therapeutic intervention towards deterrence of problem behaviour in prisons in some European countries, such as the UK, it is unlikely that such a regime would be acceptable in Europe.

  15. Occupation and suicide: Colorado, 2004-2006. (United States)

    Stallones, Lorann; Doenges, Timothy; Dik, Bryan J; Valley, Morgan A


    Occupation has been identified as a risk factor for suicide. Changes in work environments over time suggest occupations at high risk of suicide may also change. Therefore, periodic examination of suicide by occupation is warranted. The purpose of this article is to describe suicide rates by occupation, sex, and means used in Colorado for the period 2004-2006. To provide information useful in designing suicide prevention programs, the methods used in suicide across occupational groups also are examined. Data from the Colorado Violent Death Reporting System (COVDRS) were obtained for suicides that occurred between 2004 and 2006. Denominators to calculate rates by age, sex, and race used are from the 2000 US Census of the Population data. Men had higher suicide rates than women in all occupation categories except computers and mathematics. Among men, those in farming, fishing, and forestry (475.6 per 100,000) had the highest age-adjusted suicide rates. Among women, workers with the highest suicide rates were in construction and extraction (134.3 per 100,000). The examination of lethal means showed that workers in farming, fishing, and forestry had higher rates of suicide by firearms (50.18 per 100,000) compared with other workers. Healthcare practitioners and technicians had the highest rate of suicide by poisoning (14.25 per 100,000). Workers involved in construction and extraction (26.43 per 100,000) had higher rates of suicide by hanging, suffocation, or strangling. Significant differences in means of suicide were seen by occupation, which could guide future suicide prevention interventions that may decrease work-related suicide risks. Copyright © 2013 Wiley Periodicals, Inc.

  16. BLM Colorado Oil and Gas Storage Agreements (Dissolve) (United States)

    Department of the Interior — KMZ File Format –This data is one feature type that is a part of a set consisting of six shapefiles pertaining to energy development and production in Colorado. The...

  17. 78 FR 29321 - Colorado Recreation Resource Advisory Committee Meeting (United States)


    ... East Maroon Wilderness Portal, West Maroon Wilderness Portal and Maroon Lake on the White River... Advisory Committee Web site at: . DATES: The meeting will be...

  18. University of Colorado Students Join Pros in Covering Columbine Incident. (United States)

    Litherland, Chip


    Describes the experiences and feelings of a university photojournalist as he covered the shootings at Columbine High School in Littleton, Colorado. Notes the onslaught of the media presence and the overwhelming emotion he witnessed. (RS)

  19. Colorado River Sewer System Joint Venture to Upgrade Wastewater System (United States)

    SAN FRANCISCO -Today, the Colorado River Sewer System Joint Venture, located in Parker, Ariz. entered into an agreement with the EPA to upgrade their wastewater treatment system to meet stringent water quality standards. The cost of the upgrade is ap

  20. Mean-annual erosion potential for Colorado and New Mexico (United States)

    U.S. Geological Survey, Department of the Interior — The U.S. Geological Survey Data Series provides raster data representing an estimate of the mean-annual erosion potential of a 30-meter raster cell in Colorado and...

  1. BLM Colorado Oil and Gas Communitization Agreements (Dissolve) (United States)

    Department of the Interior — Shapefile Format –This data is one feature type that is a part of a set consisting of six shapefiles pertaining to energy development and production in Colorado. The...

  2. Mahogany Ledge Digital Line Outcrop of the Piceance Basin, Colorado (United States)

    U.S. Geological Survey, Department of the Interior — The Mahogany ledge outcrop was needed to limit resource calculations in the Piceance Basin, Colorado as part of a 2009 National Oil Shale Assessment.

  3. Excellence in Veterinary Medicine at Colorado State University (United States)

    Tietz, William J.


    Colorado State University has developed a strong interdisciplinary faculty that provides the entire university with graduate and undergraduate instruction in the basic biomedical sciences--anatomy, physiology, and microbiology--in addition to instruction in the professional curriculum. (LBH)

  4. Corbiculae fluminea as a bioindicator on the Lower Colorado River (United States)

    US Fish and Wildlife Service, Department of the Interior — Tissue samples from Asiatic clam (Corbimla fluminea) from the lower Colorado River were analyzed for trace element concentrations. Selenium and arsenic were elevated...

  5. Final Critical Habitat for the Little Colorado spinedace (Lepidomeda vittata) (United States)

    US Fish and Wildlife Service, Department of the Interior — provide the user with a general idea of areas where final critical habitat for Little Colorado spinedace (Lepidomeda vittata) occur based on the description provided...

  6. Final Critical Habitat for the Colorado pikeminnow (Ptychocheilus lucius) (United States)

    US Fish and Wildlife Service, Department of the Interior — To provide the user with a general idea of areas where final critical habitat for Colorado pikeminnow (Ptychocheilus lucius) occur based on the description provided...

  7. Assessment of Concrete Pavement Texturing Methodologies in Colorado (United States)


    This report presents information and data produced by the Colorado Department of Transportations : (CDOTs) long-term study of Portland cement concrete pavement (PCCP) textures used within the state. : The information includes vehicle accident, ...

  8. NPDES Permit for Leadville National Fish Hatchery in Colorado (United States)

    Under National Pollutant Discharge Elimination System permit number CO-0000582, the U.S. Department of the Interior, Fish and Wildlife Service is authorized to discharge from its Leadville National Fish Hatchery wastewater treatment facility in Colorado.

  9. NPDES Permit for Hotchkiss National Fish Hatchery in Colorado (United States)

    The U.S. Department of the Interior, Fish and Wildlife Service is authorized to discharge from outfalls at its Hotchkiss National Fish Hatchery wastewater treatment facility to the North Fork of the Gunnison River in Delta County, Colorado.

  10. BLM Colorado Oil and Gas Communitization Agreements (Dissolve) (United States)

    Department of the Interior — KMZ File Format –This data is one feature type that is a part of a set consisting of six shapefiles pertaining to energy development and production in Colorado. The...

  11. Foam drainage on the microscale - II. Imaging flow through single Plateau borders

    NARCIS (Netherlands)

    Koehler, S.A.; Hilgenfeldt, Sascha; Weeks, E.R.; Stone, H.A.


    The liquid in foam forms an interconnected network, which is composed of Plateau borders, nodes, and films. One of the dominant pathways for foam drainage is flow through Plateau borders, and we use confocal microscopy to obtain experimental results for the flow fields inside individual Plateau

  12. lateritic weathering of granite-gneiss in obudu plateau, south ...

    African Journals Online (AJOL)


    This paper reports the chemical, mineralogical and textural changes involved in the lateritization of granite-gneiss in. Obudu plateau and establishes that the susceptibility of constituent minerals to lateritic weathering is in the sequence; feldspar, Hornblende, Biotite, Quartz. Most of the chemical constituents of the basement ...

  13. Mapping risk of plague in Qinghai-Tibetan Plateau, China. (United States)

    Qian, Quan; Zhao, Jian; Fang, Liqun; Zhou, Hang; Zhang, Wenyi; Wei, Lan; Yang, Hong; Yin, Wenwu; Cao, Wuchun; Li, Qun


    Qinghai-Tibetan Plateau of China is known to be the plague endemic region where marmot (Marmota himalayana) is the primary host. Human plague cases are relatively low incidence but high mortality, which presents unique surveillance and public health challenges, because early detection through surveillance may not always be feasible and infrequent clinical cases may be misdiagnosed. Based on plague surveillance data and environmental variables, Maxent was applied to model the presence probability of plague host. 75% occurrence points were randomly selected for training model, and the rest 25% points were used for model test and validation. Maxent model performance was measured as test gain and test AUC. The optimal probability cut-off value was chosen by maximizing training sensitivity and specificity simultaneously. We used field surveillance data in an ecological niche modeling (ENM) framework to depict spatial distribution of natural foci of plague in Qinghai-Tibetan Plateau. Most human-inhabited areas at risk of exposure to enzootic plague are distributed in the east and south of the Plateau. Elevation, temperature of land surface and normalized difference vegetation index play a large part in determining the distribution of the enzootic plague. This study provided a more detailed view of spatial pattern of enzootic plague and human-inhabited areas at risk of plague. The maps could help public health authorities decide where to perform plague surveillance and take preventive measures in Qinghai-Tibetan Plateau.

  14. Predictors of Male Condom Utilization in Plateau State, Nigeria ...

    African Journals Online (AJOL)

    This study aimed to assess the condom utilization and predictors of condom use among male respondents in Plateau State. Methodology: An analysis of secondary data of the 2013 Nigeria Demographic Health Survey dataset was done. Data were collected through a cross‑sectional study using multistage cluster sampling ...

  15. Finite plateau in spectral gap of polychromatic constrained random networks (United States)

    Avetisov, V.; Gorsky, A.; Nechaev, S.; Valba, O.


    We consider critical behavior in the ensemble of polychromatic Erdős-Rényi networks and regular random graphs, where network vertices are painted in different colors. The links can be randomly removed and added to the network subject to the condition of the vertex degree conservation. In these constrained graphs we run the Metropolis procedure, which favors the connected unicolor triads of nodes. Changing the chemical potential, μ , of such triads, for some wide region of μ , we find the formation of a finite plateau in the number of intercolor links, which exactly matches the finite plateau in the network algebraic connectivity (the value of the first nonvanishing eigenvalue of the Laplacian matrix, λ2). We claim that at the plateau the spontaneously broken Z2 symmetry is restored by the mechanism of modes collectivization in clusters of different colors. The phenomena of a finite plateau formation holds also for polychromatic networks with M ≥2 colors. The behavior of polychromatic networks is analyzed via the spectral properties of their adjacency and Laplacian matrices.

  16. Protozoan Diversity in a productive fishpond of a tropical plateau ...

    African Journals Online (AJOL)

    A survey of the Protozoan species diversity in a productive fishpond of the Jos Plateau, Nigeria was investigated at 7 day interval over a period of 11 months. Samples were collected from water column and sediment. Protozoans were found to compose of the flagellates sarcodines and cilliates. There was a significant ...

  17. Outcome of cataract surgeries in Plateau State, Nigeria | Odugbo ...

    African Journals Online (AJOL)

    Aim: To evaluate the outcome of cataract surgeries in terms of restoration of visual function in the operated eye in Plateau State, Nigeria. Method: Four centres were selected using stratified random sampling technique. Consecutive patients, who had cataract extraction from 1st October 2002 - 31st March 2003, were ...

  18. Common Leg Aliment Of Poultry In Plateau State, Nigeria | Ogbe ...

    African Journals Online (AJOL)

    ... cockerels 17(18.68 %), guinea fowls 15(39.47 %) and ostriches2(5.26 %). Curled toes, mange, Newcastle disease, Mareks disease and Clostridia infections resulting in leg ailments were also observed. Keywords: Leg ailments, Poultry, Implication, Plateau State Animal Research International Vol. 1 (3) 2004 pp. 208-211 ...

  19. The structure of foam cells: isotropic plateau polyhedra

    NARCIS (Netherlands)

    Hilgenfeldt, Sascha; Kraynik, A.M.; Reinelt, D.A.; Sullivan, J.M.


    A mean-field theory for the geometry and diffusive growth rate of soap bubbles in dry 3D foams is presented. Idealized foam cells called isotropic Plateau polyhedra (IPPs), with F identical spherical-cap faces, are introduced. The geometric properties (e.g., surface area S, curvature R, edge length

  20. Eddy formation around South West Mascarene Plateau (Indian Ocean)

    African Journals Online (AJOL)

    Acoustic Doppler Current Profiler (ADCP) measurements undertaken through the hydrographic survey by RRS Charles Darwin in June-July 2002. They described these current systems as a 'northern and southern core', with the northern core passing through the Plateau in between Saya de Malha and. Nazareth Banks ...

  1. Regional Wave Propagation in and around the Tibetan Plateau, (United States)


    displays. The path to AMDO does not enter the north- ern plateau anomalous zone, while the paths to WNDO, ERDO, and BUDO represent increasing At BUDO , the Sn waveform is essentially a broad step, significantly different from the more pulse-like Pn waveform. This difference is consistent

  2. Prevalence of snakebites in Taraba and Plateau States of Nigeria ...

    African Journals Online (AJOL)

    This study was undertaken to outline the epidemiological profile of snakebites in the middle belt region of Nigeria, using Plateau and Taraba States as a case study. Records of 917 cases of snakebites from eight secondary health facilities, spread across the two states were collected retrospectively, covering January 1999 ...

  3. Lateritic weathering of granite-gneiss in Obudu Plateau, south ...

    African Journals Online (AJOL)

    Obudu Plateau (Latitudes 60 30`N, 6045`N and Longitudes 9015`E, 10000`E) is a basement Horst bordered in the East by the Cameroun volcanic line, both of which form the Bamenda massif. This is a zone of migmatite-gneissschist complex with subordinate occurrence of amphibolites, charnockites and minor intrusive of ...

  4. Farmers' reason for going into poultry production in Plateau state ...

    African Journals Online (AJOL)

    Those in poultry production have reasons for going into the business. This study aimed at investigating the effect of the reasons for going into poultry production on the profit of poultry farmers in Plateau State. Random sampling technique was used to select 60 respondents from 4 Local Government Areas of the state.

  5. Is there seasonality in deliveries on the Plateau? | Daru | Tropical ...

    African Journals Online (AJOL)

    Objective- To determine if there are seasonal variations in delivery rates in JUTH, Jos, Plateau state, Nigeria Material and Methods- This is a retrospective descriptive study carried out in JUTH, Jos, Nigeria. The monthly delivery records from 1985-2011 (26 years) were extracted from the labour ward delivery record.

  6. Shade tolerance of selected afforestation species on Loess Plateau, China (United States)

    Naijiang Wang; Yong Wang; Callie J. Schweitzer


    To select tree and vegetation species for afforestation on Loess Plateau of China, we tested the shade tolerance of nine tree and one vine species. We planted 3-year-old seedlings in the greenhouse of the Seedling Nursery at Northwest Agriculture and Forest University in China.

  7. Testicular torsion on the Jos Plateau | Ugwu | West African Journal ...

    African Journals Online (AJOL)

    Testicular pain, retraction and scrotal swelling were the most common presenting complaints. The highest incidence 65%) occurred between November and February when the weather on the Jos plateau is coldest. At surgery, 34 (60%) patients were found to have associated congenital anomalies; in 22 (39%) patients, the ...

  8. Sensitivity of LUCC on the Surface Temperature of Tibetan Plateau (United States)

    Qi, W.; Deng, X.; Wu, F.


    The Tibetan Plateau has an important effect on the ecological security in China, even in Asia, which makes the region become the hot spot in recently research. Under the joint influence of global change and human activities, ecosystem destabilizing and the increasing pressure on resources and environment emerge on the Tibetan Plateau, but the potential spatial sensitivity of land use and land cover changes(LUCC) on surface temperature has not been quantitatively analyzed. This study analyzed the mainly types of LUCC, urbanization, grassland degradation, deforestation on Tibetan Plateau along with Representative Concentration Pathways (RCPs) of the Intergovernmental Panel on Climate Change (IPCC). The LUCC in recent decades was first quantitatively analyzed in this study to give the basic fact with a significant increase in temperatures, reduced precipitation and increased evaporation. This study focused on the future spatio-temporal heterogeneity of the temperature and precipitation. Finally, the influencing factors with LUCC on Tibetan Plateau were simulated with the Weather Research and Forecasting (WRF) model, and the sensitivity of different land use types was spatially analyzed with Singular Value Decomposition (SVD). The results indicate that the large-area alpine grassland plays a more important role in alleviating global warming than other vegetation types do. The changes of the landscape structure resulting from the urban expansion play a significant role in intensifying regional temperature increase. In addition, the effects of LUCC on monthly average temperature change would vary from month to month with obviously spatial heterogeneity.

  9. Geochemistry of Schists of Northwest Obudu Plateau, Southeastern ...

    African Journals Online (AJOL)

    Precambrian, highly foliated, fine – medium grained schists, which comprise migmatitic schist (MS), quartz mica schist (QMS), biotite mica schist (BMS) and hornblende biotite schist (HBS) constitute important lithological unit in Northwest Obudu Plateau. The schists are associated with gneisses, amphibolites and ...

  10. Checklist of Phytoplankton of Shendam Reserviour in Plateau State ...

    African Journals Online (AJOL)

    A qualitative study of phytoplankton flora was carried out in Shendam reservoir, Plateau state of Nigeria. Seventy one species were recorded indicating a fairly low species number when compared to other Nigerian waters. The major groups of phytoplankton found were chlorophyceae, bacilliarophyceae, cyanophyceae and ...

  11. An attempt to understand the observed plateau of the magnetization ...

    Indian Academy of Sciences (India)

    The next-nearest-neighbour (NNN) effect in tetranuclear iron(II) complexes of thiacalixarene macrocycles using the isotropic Heisenberg model has been investigated in order to understand its effects on the observed plateau of magnetization. Although NNN effect is generally very weak in these kinds of systems, it was ...

  12. Rainfall Erosivity Factor for Uasin Gishu Plateau, Kenya | Kariaga ...

    African Journals Online (AJOL)

    Runoff plots were established on bare soil classified as Dystric Nitosols (Typic Rhodudults) at Moi University Main Campus, on Uasin Gishu Plateau, Kenya. The objective of the study was to determine the best erosivity factor for the area. This was found to be EI30, defined as the product of the rainstorm's kinetic energy and ...

  13. New transhumance in the Mahafaly Plateau region in Madagascar

    African Journals Online (AJOL)

    ). ... Elle. ARTICLE The cattle raiders leave us no choice: New transhumance in the Mahafaly Plateau region in. Madagascar. Johanna F. ...... during fifteen years' captivity on that island. T. Fisher Unwin ...

  14. Excessive afforestation and soil drying on China's Loess Plateau (United States)

    Zhang, Shulei; Yang, Dawen


    Afforestation and deforestation are human disturbances to vegetation, which have profound impacts on regional eco-hydrological processes, the water and carbon cycles, and consequently, ecosystem sustainability. Since 1999, large scale revegetation has been carried out across China's Loess Plateau following the "Grain-to-Green Program" implemented by the Chinese government. This revegetation, particularly with forest, has caused negative eco-hydrological consequences, including streamflow decline and soil drying. Here, we have used "ecosystem optimality theory" and satellite observations, to assess the water balance under the climate-defined optimal and actual vegetation cover during 1982-2010 and its responses to future climate change (2011-2050) over the Loess Plateau. Results show that the current vegetation cover (0.48 on average) has already exceeded the climate-defined optimal cover (0.43 on average) in the most recent decade, especially in the middle-to-east Loess Plateau, indicating that it is the widespread over-planting, which is primarily responsible for soil drying in the area. In addition, both the optimal vegetation cover and soil moisture tend to decrease under future climate scenarios. Our findings suggest that further revegetation on the Loess Plateau should be applied with caution. To maintain a sustainable eco-hydrological environment in the region, a revegetation threshold should be urgently set, to limit future planting.

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

    DEFF Research Database (Denmark)

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


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

  16. A Younger Dryas plateau icefield in the Monadhliath, Scotland, and implications for regional palaeoclimate (United States)

    Boston, Clare M.; Lukas, Sven; Carr, Simon J.


    A record of Younger Dryas glaciation in Scotland is well established. However, the role of the Monadhliath, a significant plateau area extending over 840 km2 in central Scotland, has never been investigated systematically. We present the first systematic glacial geomorphological mapping across the whole region, which has led to the identification of hitherto-unrecorded glacial and associated landforms. The spatial distribution of these landforms indicates that the last phase of glaciation in the area was that of a local plateau icefield. In addition, a clear morphostratigraphical signature provides a strong indication that the icefield dates to the Younger Dryas (12.9-11.7 ka), which is supported by numerical ages in the southeast of the study area. Based on the geomorphological evidence and 2D glacier surface profile modelling, a 280 km2 icefield is reconstructed. A novel approach is introduced to quantify plateau icefield thickness for equilibrium line altitude (ELA) and palaeoprecipitation calculations, resulting in greater overall data confidence compared to traditional reconstruction methods. The ELA for the whole icefield is calculated to be 714 ± 25 m, whilst the ELAs of individual outlet glaciers range from 560 m in the west to 816 m in the east, demonstrating a significant W-E precipitation gradient across the region during the Younger Dryas. These ELAs compare well with those calculated for Younger Dryas ice masses reconstructed in neighbouring regions and are in good agreement with overall precipitation patterns suggested for Scotland during this time. Whilst the total amount of precipitation calculated from these ELAs is highly dependent on the method used, irrespective of this, the study suggests a more arid Younger Dryas climate in the region compared to the present day.

  17. Adjusting the M8 algorithm to earthquake prediction in the Iranian plateau (United States)

    Mojarab, Masoud; Memarian, Hossein; Zare, Mehdi; Kossobokov, Vladimir


    Earthquake prediction is one of the challenging problems of seismology. The present study intended to setup a routine prediction of major earthquakes in the Iranian plateau using a modification of the intermediate-term middle-range algorithm M8, in which original version has demonstrated high performance in a real-time Global Test over the last two decades. An investigation of earthquake catalog covering the entire the Iranian plateau through 2012 has shown that a modification of the M8 algorithm, adjusted for a rather low level of earthquake occurrence reported in the region, is capable for targeting magnitude 7.5+ events. The occurrence of the April 16, 2013, M7.7 Saravan and the September 24, 2013, M7.7 Awaran earthquakes at the time of writing this paper (14 months before Saravan earthquake occurrence) confirmed the results of investigation and demonstrated the need for further studies in this region. Earlier tests, M8 application in all over the Iran, showed that the 2013 Saravan and Awaran earthquakes may precede a great earthquake with magnitude 8+ in Makran region. To verify this statement, the algorithm M8 was applied once again on an updated catalog to September 2013. The result indicated that although the study region recently experienced two magnitude 7.5+ earthquakes, it remains prone to a major earthquake. The present study confirms the applicability of M8 algorithm for predicting earthquakes in the Iranian plateau and establishes an opportunity for a routine monitoring of seismic activity aimed at prediction of the largest earthquakes that can play a significant role in mitigation of damages due to natural hazard.

  18. Functional outcome of Schatzker type V and VI tibial plateau fractures treated with dual plates

    Directory of Open Access Journals (Sweden)

    G Thiruvengita Prasad


    Full Text Available Background: Dual plate fixation in comminuted bicondylar tibial plateau fractures remains controversial. Open reduction and internal fixation, specifically through compromised soft tissues, has historically been associated with major wound complications. Alternate methods of treatment have been described, each with its own merits and demerits. We performed a retrospective study to evaluate the functional outcome of lateral and medial plate fixation of Schatzker type V and VI fractures through an anterolateral approach, and a medial minimally invasive approach or a posteromedial approach. Materials and Methods: We treated 46 tibial plateau fractures Schatzker type V and VI with lateral and medial plates through an anterolateral approach and a medial minimal invasive approach over an 8 years period. Six patients were lost to followup. Radiographs in two planes were taken in all cases. Immediate postoperative radiographs were assessed for quality of reduction and fixation. The functional outcome was evaluated according to the Oxford Knee Score criteria on followup. Results: Forty patients (33 men and 7 women who completed the followup were included in the study. There were 20 Schatzker type V fractures and 20 Schatzker type VI fractures. The mean duration of followup was 4 years (range 1-8 years. All patients had a satisfactory articular reduction defined as ≤2 mm step-off or gap as assessed on followup. All patients had a good coronal and sagittal plane alignment, and articular width as assessed on supine X-rays of the knee in the anteroposterior (AP and lateral views. The functional outcome, as assessed by the Oxford Knee Score, was excellent in 30 patients and good in 10 patients. All patients returned to their pre-injury level of activity and employment. There were no instances of deep infection. Conclusions: Dual plate fixation of severe bicondylar tibial plateau fractures is an excellent treatment option as it provides rigid fixation and

  19. Long Range Materials Research (United States)


    electrolyses at potentials corresponding to the first cathodic wave yielded deposits of Nb--Ce compounds. Electrolyses under . V^ l!\\I3ddnD 127. the Nb-stripping process. Electrolyses at potentials corresponding tc the plateau between the two cathodic waves resulted in verv thin adherent...voltammo- grams of lower germanium concentrations revealed only one step on the first cathodic potential, see Fig. 6. Constant potential electrolyses

  20. Colorado Homeowner Preferences on Energy and Environmental Policy

    Energy Technology Data Exchange (ETDEWEB)

    Farhar, B. C.; Coburn, T. C.


    This survey inquiring into Colorado homeowners' preferences on energy and environmental policy shows that more-affluent, married Colorado single-family homeowners are somewhat favorable to utility restructuring; want to see green power developed; prefer to share the costs broadly by various means; are willing to pay slightly higher electricity rates to develop renewable sources of electricity; and believe that utility customers don't have enough choice in their electric service today.

  1. Methane in Cretaceous and Paleocene coals of western Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Tremain, C.M.; Boreck, D.L.; Kelso,B.S.


    Western Colorado is the site of coal, oil, and natural gas development in three principal areas: the San Juan River, the Unita, and the Green River regions. Evidence is accumulating that some of the coals in these regions both act as a source and potential reservoir for natural gas (methane). This paper details some of the evidence and describes work being done by the Colorado Geological Survey to estimate methane resources of these regions. (JMT)

  2. A Study about the Influence of Plateau Shear Line on Abnormal Precipitation in the Area to the East of the Tibetan Plateau (United States)

    Xiao, T.; Wang, L.; Jia, L.; Chen, Y.


    Based on the activity characteristics of 571 Tibetan plateau shear line processes in 1998-2013, this paper studies the difference of circulation feature between the plateau shear line which has and has not moved out of the plateau area, and the relationship between it and plateau atmospheric low-frequency signal transmission,water vapor channel, energy transmission and conversion due to the influence of eastward-moving of plateau shear line on abnormal precipitation in Sichuan Basin. (1) The 571 plateau shear lines include 519 transverse shear lines and 52 vertical shear lines, of which 92 shear lines move out of the plateau area.Composite analysis discovered that the circulation feature of two-through and one-ridge type is in favor of moving-out of transverse plateau shear lines; the multiple fluctuations circulation type are in favor of moving-out of vertical plateau shear lines. Deepening of Baikal deep trough, weakening of high ridge before the deep trough, weakening of East Asia deep trough, invasion of warm advection and positive vorticity advection, western extension of subtropical high and reinforcement of south Asia high are all in favor of reinforcement and moving-out of vertical plateau shear lines. The Butterworth band-pass filtering signal shows that the plateau shear lines mainly appear in the place near peaks and troughs with zonal wind oscillatory for 30-60d. (2) By using HYSPLIT backward trajectory model to track the water vapor transmission path of precipitation in Sichuan Basin which is formed by eastward-moving of transverse plateau shear lines and vertical plateau shear lines, it shows that the influence of transverse plateau shear lines on the basin is from two water vapor channels,the influence of vertical plateau shear lines is from a channel. Plateau shear lines are different in water vapor convergence and and divergence and trajectory in different phases and at different altitudes. (3)the wave-packet propagation diagnosis shows that

  3. Colorado Yule Marble; building stone of the Lincoln Memorial (United States)

    McGee, Elaine S.


    The Colorado Yule marble, quarried in Marble, Colo., is a very pure white marble, and it has been widely acclaimed for its quality and purity. This marble has been used for many prominent buildings; one of the most notable is the Lincoln Memorial in Washington, D.C., built nearly 80 years ago. Although most of the marble in the memorial appears to be in very good condition, some of the stones have developed pronounced surficial roughness and show a significant loss of carved details and rounded edges compared with adjacent stones. Because adjacent blocks of marble receive nearly identical exposure to weathering agents that cause deterioration of the marble, it seems very likely that this pronounced difference in durability of adjacent stones arises from some inherent characteristic of the marble. The Colorado Yule marble is a nearly pure calcite marble with minor inclusions of mica, quartz, and feldspar. Compositions of the calcite and the inclusion phases in the marble are typical for those phases. The calcite grains that compose the marble are irregularly shaped and range from 100 to 600 micrometers in diameter. The texture of the marble is even, with a slight preferred directional elongation that is visible when the marble is cut in certain directions. Physical tests of the marble show that its strength is comparable to that of other marbles typically used in buildings. Variations in the durability of the marble, like those seen at the Lincoln Memorial, are not related to variations in calcite composition or to the presence of inclusions in the marble. Most likely, the variations arise from differences in the calcite grain boundaries and the degree to which the grains interlock with one another. Weak grain boundaries that permit water or solutions to penetrate into the marble and dissolve the calcite grains at their edges cause the marble to disaggregate or ?sugar.? Subtle differences in texture that occur in the marble from various parts of the quarry probably

  4. Marijuana use and associated motives in Colorado university students. (United States)

    Phillips, Kristina T; Lalonde, Trent L; Phillips, Michael M; Schneider, Maryia M


    Marijuana is the most commonly used illicit drug among college students, with heavy use leading to negative outcomes. Use of marijuana for medical and recreational purposes in select U.S. states has been controversial, with concerns surrounding increased prevalence rates and harm. The current exploratory study aimed to assess marijuana use in college students in Colorado, demographic differences in frequency of use, and motives for using. College students (N = 300; 61% female) were recruited through introductory psychology courses and completed a series of questionnaires and a marijuana urine screen. Almost three-fourths of the sample reported lifetime use of marijuana. Sixty-five percent used marijuana within the last year and 29% tested positive on the urine screen. Hurdle Poisson regression models with a subset of participants (n = 117) showed non-Greek and freshman status were associated with increased number of days participants used marijuana in the last month. Problem marijuana use was positively associated with a range of motives-of note-motives focused on coping, boredom, alcohol, and food. Prevalence rates of marijuana use were high in this sample of college students in a state with legal recreational marijuana use. Particular students (eg, students who use marijuana to cope) may be at higher risk for problem marijuana use. Developing effective, tailored interventions for university students is warranted. (Am J Addict 2017;XX:1-8). Copyright © 2017 American Academy of Addiction Psychiatry.

  5. Environmental sampling for Salmonella spp. in Colorado animal shelters. (United States)

    Steneroden, K K; Hill, A E; Salman, M D


    Salmonella enterica is an important zoonotic agent and nosocomial infections and epidemics have occurred in animal facilities. The objective of this study was to estimate the prevalence of Salmonella in the environment in animal shelters. From 12 to 25 samples were taken from each shelter to represent environmental contamination. Samples were collected from surfaces in areas used by animals and in public access areas including animal receiving rooms, kennels, paediatric wards, treatment, visitation rooms, isolation, euthanasia, outdoor runs and play areas, reception rooms, animal transport vehicles, offices, break rooms and restrooms. Samples were tested for Salmonella and compared within shelters to identify high- and low-risk areas; and between shelters to identify differences in environmental contamination by geographical location, infection control policies, and shelter size characteristics. Twenty-eight per cent of sampled Colorado shelters had environmental Salmonella contamination. Two regions in the eastern 1/3 of the state had prevalences of 30% and 100%. Within-shelter sample prevalence ranged from 0 to 100%. Results of this study indicate that animal shelters can be frequently contaminated with Salmonella spp., a variety of Salmonella species may be present, contamination can be widespread within a facility and recovered isolates may harbour antibiotic resistance The findings from this study may influence and help focus educational policy on issues of infection control and zoonotic disease awareness in animal shelters. © 2010 Blackwell Verlag GmbH.

  6. Anvil Points oil shale tailings management in Rifle, Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Rudy, R.; Galli LaBerge, C.; McClurg, J. [Ecology and Environment Inc., Lancaster, NY (United States); Walsh Integrated, Lachine, PQ (Canada)


    This presentation summarized the oil shale tailings management program used at the Anvil Points mining site in Colorado. Decommissioning and reclamation of the site occurred between 1984 and 1986. The geology of the region is comprised of Tertiary bedrock sedimentary formations and Quaternary formations on the surface. Oil shales mined at the facility are from the Eocene Green River formation. While the site lies within big game winter ranges, the areas around the shale pile supports are not a significant nesting or feeding habitat for wildlife. No sensitive plants are located on the waste shale pile. The program currently includes revegetation test plots and the reclamation of an area where heating oil storage tanks were located. The dumping area is currently being monitored, and geophysical surveys are being conducted. Documents produced by mining activities are also being reviewed. Results of the study to date have indicated the presence of asbestos-containing materials, significant physical hazards, and significant cultural resources. An engineering evaluation and cost analysis has demonstrated that arsenic, beryllium, and iron exceed established soil screening levels. It was concluded that off-site removal actions will be conducted to prevent or reduce human exposure to the metals of concern. tabs., figs.

  7. Geology of the Cerro Summit quadrangle, Montrose County, Colorado (United States)

    Dickinson, Robert G.


    The Cerro Summit quadrangle covers 58 square miles of dissected plateau on the south flank of the Gunnison uplift in southwestern Colorado. It lies east of the Uncompahgre River valley and south of the Black Canyon of the Gunnison River. Rocks dip gently in most of the quadrangle, but they are locally upturned and faulted on the margin of the Gunnison uplift and are intensely deformed in the core of the uplift. The rocks exposed are of Precambrian, late Mesozoic, and Cenozoic age. Precambrian rocks include metasedimentary schist and gneiss, granitic pegmatite, and olivine gabbro. The oldest Mesozoic rocks exposed are continental, fresh-water, and lagoonal deposits in the Late Jurassic Entrada Sandstone, Wanakah Formation, and Morrison Formation. Channel-fill deposits that unconformably overlie the Jurassic rocks are possibly the Burro Canyon Formation of Early Cretaceous age. Upper Cretaceous rocks include marine and nearshore deposits of the Dakota Sandstone, Mancos Shale, and Pictured Cliffs Sandstone, and the fresh- and brackish-water sandstone, shale, and coal of the Fruitland Formation. Rocks of Late Cretaceous age that crop out in the adjacent Cimarron Ridge area may also have been deposited in this quadrangle but are now eroded; these rocks include the nonmarine Kirtland Shale and an unnamed volcanic conglomerate and tuff breccia. Nine faunal zones in the Mancos Shale help to establish the correct correlation of units in the Upper Cretaceous. The Pictured Cliffs Sandstone, Fruitland Formation, and Kirtland Shale of the Cerro Summit area have been mapped by some geologists as the Mesaverde Formation. Fossils indicate that the rocks are younger than the type Mesaverde. The unnamed volcanic rocks represent major volcanism in nearby areas. A Late Cretaceous (Maestrichtian) age for the volcanism is indicated by palynological evidence and an isotopic age of approximately 66 million years. Middle Tertiary rocks are conglomerate and tuff breccia. Upper Tertiary or

  8. Economic impact study of the Uranium Mill Tailings Remedial Action Project in Colorado: Colorado State fiscal year 1994. Revision 1

    Energy Technology Data Exchange (ETDEWEB)


    The Colorado economic impact study summarizes employment and economic benefits to the state from activities associated with the Uranium Mill Tailings Remedial Action (UMTRA) Project during Colorado state fiscal year 1994 (1 July 1993 through 30 June 1994). To capture employment information, a questionnaire was distributed to subcontractor employees at the active UMTRA Project sites of Grand Junction, Naturita, Gunnison, and Rifle, Colorado. Economic data were requested from each site prime subcontractor, as well as from the Remedial Action Contractor. Information on wages, taxes, and subcontract expenditures in combination with estimates and economic multipliers is used to estimate the dollar economic benefits to Colorado during the state fiscal year. Finally, the fiscal year 1994 estimates are compared to fiscal year 1993 employment and economic information.

  9. Early Cenozoic Multiple Thrust in the Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Zhenhan Wu


    Full Text Available Recently completed regional geological mapping at a scale of 1 : 250,000 or larger across all of the Tibetan Plateau coupled with deep seismic surveys reveals for the first time a comprehensive depiction of the major early Cenozoic thrust systems resulting from the northward subduction of the Indian Continental Plate. These systems define a series of overlapping north-dipping thrust sheets that thickened the Tibetan crust and lead to the rise of the plateau. The few south-dipping thrusts present apparently developed within a sheet when the back moved faster than the toe. Many of the thrusts are shown to extend to the middle-lower crustal depths by seismic data. The regional thrust systems are the Main Central, Renbu-Zedong, Gangdese, Central Gangdese, North Gangdese, Bangoin-Nujiang, Qiangtang, Hohxil, and South Kunlun Thrusts. The minimal southward displacements of the South Kunlun, Hohxil, South Qiangtang, and Central Gangdese Thrusts are estimated to be 30 km, 25 km, 150 km and 50 km, respectively. Deep thrusting began in the Himalaya-Tibetan region soon after India-Eurasia continental collision and led to crustal thickening and subsequent uplift of the Tibetan Plateau during Late Eocene-Early Miocene when the systems were mainly active. The major thrust systems ceased moving in Early Miocene and many were soon covered by lacustrine strata. This activity succeeded in the late Cenozoic to crustal extension and strike-slip movement in the central Tibetan Plateau. The revelation of the full array of the early Cenozoic thrust systems provides a much more complete understanding of the tectonic framework of the Tibetan Plateau.

  10. Greenhouse gases emissions in rivers of the Tibetan Plateau. (United States)

    Qu, Bin; Aho, Kelly Sue; Li, Chaoliu; Kang, Shichang; Sillanpää, Mika; Yan, Fangping; Raymond, Peter A


    Greenhouse gases (GHGs) emissions from streams are important to regional biogeochemical budgets. This study is one of the first to incorporate stream GHGs (CO 2 , CH 4 and N 2 O) concentrations and emissions in rivers of the Tibetan Plateau. With one-time sampling from 32 sites in rivers of the plateau, we found that most of the rivers were supersaturated with CO 2 , CH 4 and N 2 O during the study period. Medians of partial pressures of CO 2 (pCO 2 ), pCH 4 and pN 2 O were presented 864 μatm, 6.3 μatm, and 0.25 μatm respectively. Based on a scaling model of the flux of gas, the calculated fluxes of CO 2 , CH 4 and N 2 O (3,452 mg-C m 2 d -1 , 26.7 mg-C m 2 d -1 and 0.18 mg-N m 2 d -1 , respectively) in rivers of the Tibetan Plateau were found comparable with most other rivers in the world; and it was revealed that the evasion rates of CO 2 and CH 4 in tributaries of the rivers of the plateau were higher than those in the mainstream despite its high altitude. Furthermore, concentrations of GHGs in the studied rivers were related to dissolved carbon and nitrogen, indicating that riverine dissolved components could be used to scale GHGs envision in rivers of the Tibetan Plateau.

  11. A Regional Approach to Wildlife Monitoring Related to Energy Exploration and Development in Colorado (United States)

    Kotliar, Natasha B.; Bowen, Zachary H.; Ouren, Douglas S.; Farmer, Adrian H.


    : White River, Glenwood Springs, Kremmling, Grand Junction, and Little Snake. The overall study area was selected to encompass the primary distribution of sagebrush and greater sage-grouse (Centrocercus urophasianus) in Colorado and to provide a larger context for evaluating priority management issues of the White River and Glenwood Springs Field Offices. Within the study area, we selected an additional scale of analysis: the Roan Plateau, an area of increased energy development. We focused our demonstration project on the primary objectives identified by the BLM and other stakeholders: (1) How do we evaluate the cumulative effects of energy development and mitigation activities on species of management interest or concern? (2) How can cumulative effects, including direct and indirect effects, be quantified relative to natural variation? (3) How can we implement compliance and effectiveness monitoring to determine whether lease stipulations are met and restoration/mitigation goals are achieved? We targeted greater sage-grouse because this species was identified as a monitoring priority for the White River Field Office. We also evaluated landscape-level indices to address fragmentation resulting from surface disturbance. The primary purpose of this exercise was to highlight the types of analyses and approaches that could be used to evaluate energy development in an application of the three-phase framework. We provide examples of Phase I products that can be used to guide the refinement of management objectives, development of adaptive management and research frameworks, and planning activities in Phase II. Finally, we report on the BLM's National Sage-Grouse Habitat Conservation Strategy as an example of Phase III activities. The development of an effective monitoring program is a daunting task, and will be difficult to implement by the BLM independently due to the current work load of staff. However, the scientific expertise and experience for developing cr

  12. Phylogeography of Cephalotaxus oliveri (Cephalotaxaceae) in relation to habitat heterogeneity, physical barriers and the uplift of the Yungui Plateau. (United States)

    Wang, C B; Wang, T; Su, Y J


    Habitat heterogeneity, physical barriers, and the uplift of the Yungui Plateau were found to deeply affect the phylogeographic pattern and evolutionary history of Cephalotaxus oliveri, a perennial conifer endemic to China. In this study, we explored the phylogeography using three chloroplast sequences (trnL-trnF, trnT-trnD and atpB-rbcL) in 22 natural populations of C. oliveri distributed throughout its range. The Yungui Plateau populations of C. oliveri were revealed to origin ca. 9.15Ma by molecular clock estimation, which is consistent with rapid uplift of the Qinghai-Tibetan Plateau (QTP) ca. 8-10Ma. Additionally, geological effects of the Yungui Plateau were suggested to promote the rapid intra-specific differentiation of C. oliveri in the Pliocene and Early Pleistocene. The relatively low level of genetic diversity (h=0.719, θ=1.17×10(-3)) and high population differentiation (NST=0.771 and GST=0.642) implied restricted gene flow among populations, which was confirmed by the Nested Clade Analysis (NCA). Mismatch distribution and haplotypes network provided evidences of recent demographic population expansion. Furthermore, the statistical dispersal-vicariance analysis indicated that the center of origin was in Central China. The comparison of haplotype distribution patterns indicated that the regions of HNHPS and HBLD were the potential refugia during the Pleistocene ice ages. Our results highlighted that habitat heterogeneity and physical barriers presenting in a species range can predict genetic patterns. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Three Dimensional Lithospheric Electrical Structure of the Tibetan Plateau as Revealed by SinoProbe Long Period Magnetotelluric Array Data (United States)

    Wei, Wenbo; Zhang, Letian; Jin, Sheng; Ye, Gaofeng; Jing, Jianen; Dong, Hao; Xie, Chengliang; Yin, Yaotian


    The on-going continent-continent collision between the Indian and Eurasian plates since 55 Ma has created the spectacular topography of the Tibetan plateau. However, many first order questions remain to be answered as to the mechanisms behind this young orogenic process. Under the auspices of the SinoProbe Project, a three dimensional (3-D) Magnetotelluric (MT) array have been deployed on the Tibetan Plateau from 2010 to 2013 to better understand this orogeny. By the end of 2013, 1099 MT stations have been completed, including 102 combined broadband MT (BBMT) and long period MT (LMT) stations. In this study, MT data of these 102 combined stations have been used to investigate the deep lithospheric electrical structure of the Tibetan Plateau. MT impedances within the period range of 10 - 50000 s were extracted to be used for 3-D inversions with the ModEM code using the standard NLCG algorithm. The resulting lithospheric electrical structure of the Tibetan Plateau shows a distinct pattern of strong variation not only vertically, but also horizontally. Conductors are found to be widespread in the middle to lower crust. But their geometries are quite complex, and not obviously consistent with the hypothesis of continuous eastward channel flow. Instead, most crustal conductors in central and southern Tibet display a pattern of N-S extension. In the depth range of the upper mantle, two more conductive regions can be identified in the southern Qiangtang Terrane and in the central Lhasa Terrane. Resistor associated with the underthrust Inidan plate can be traced beneath the Bangong-Nujiang suture in western Tibet, but only beneath the central Lhasa terrane in central Tibet. * This work was jointly supported by the grants from Project SinoProbe-01 and National Natural Science Foundation of China (41404060).

  14. [Latitudinal Changes in Plant Stoichiometric and Soil C, N, P Stoichiometry in Loess Plateau]. (United States)

    Li, Ting; Deng, Qiang; Yuan, Zhi-you; Jiao, Feng


    Field investigations and sampling were conducted in Loess Plateau, including Fu County, Ganquan County, Ansai County, Jingbian County and Hengshan County and Yuyang District. Our objective was to examine changes of leaf and soil stoichiometry characteristics along latitudinal gradient in Loess Plateau, and to provide references for the prediction of soil nutrient status of the ecosystem and constraints of plant nutrition elements in Loess Plateau. The results showed that (1) Across the 35.95 degrees-38.36 degrees N latitude gradient, leaf C, N and P stoichiometry were ranging from 336.95 to 477.38 mg x g(-1) for C, from 18.09 to 33.173 mg x g(-1) for N and from 1.07 to 1.73 mg x g(-1) for P, the arithmetic means were 442.9 mg x g(-1), 25.79 mg x g(-1) and 1.37 mg x g(-1), separately, the variation coefficients were 11.9%, 17.4% and 13.3%. There were obvious correlation between leaf C, N, P and latitude, leaf C, C : N ratio and C: P ratio significantly decreased with the increasing latitude, while leaf N and P significantly increased with the increasing latitude. The relationship between N: P ratio and latitude was not significant. (2) The content of soil organic C and soil total N decreased with increasing latitude and soil layer. In contrast, with the increase of latitude, soil P increased and then decreased. In the 0-10 cm, 10-20 cm soil layers, soil C: N ratio did not change significantly with latitude, while in the 20-40 cm layer, C: N ratio decreased obviously, but soil C: P and N: P ratios decreased with the increasing latitude in all soil layers. (3) Leaf C, C: N and C: P ratios were correlated to soil organic C, soil total N and soil total P in all soil layers, leaf N and P were correlated to soil organic C and soil total N, while leaf N: P ratio was not correlated to soil organic C, soil total N and soil total P. There was a certain correlation between the leaf C, N, P and latitude, however, the correlations between leaf and soil C, N, P were inconsistent

  15. Understorey plant community dynamics following a large, mixed severity wildfire in a Pinus ponderosa-Pseudotsuga menziesii forest, Colorado, USA (United States)

    Paula J. Fornwalt; Merrill R. Kaufman


    In 2002, the Hayman Fire burned across 55 800 ha of Colorado Front Range P. ponderosa-P. menziesii forest. Also burned in the fire were 20 upland and five riparian plots within a 400-ha study area. These plots had been surveyed for understorey plant composition and cover 5-6 yrs prior. We re-measured all plots annually from 2003 to 2007, 1-5 yrs post-fire. Changes in...

  16. Shiga Toxin-Producing Escherichia coli in Plateau Pika (Ochotona curzoniae on the Qinghai-Tibetan Plateau, China

    Directory of Open Access Journals (Sweden)

    Xiangning eBAI


    Full Text Available Shiga toxin-producing Escherichia coli (STEC are an emerging group of zoonotic pathogens. Ruminants are the natural reservoir of STEC. In this study we determined the prevalence and characteristics of the STEC in plateau pika (Ochotona curzoniae on the Qinghai-Tibetan Plateau, China. A total of 1116 pika samples, including 294 intestinal contents samples, 317 fecal samples, and 505 intestinal contents samples, were collected from May to August in the years 2012, 2013 and 2015, respectively. Twenty-one samples (1.88% yielded at least one STEC isolate; in total, 22 STEC isolates were recovered. Thirteen different O serogroups and 14 serotypes were identified. One stx1 subtype (stx1a and three stx2 subtypes (stx2a, stx2b and stx2d were present in the STEC isolates. Fifteen, fourteen and three STEC isolates harbored the virulence genes ehxA, subA, and astA, respectively. Adherence-associated genes iha and saa were respectively present in 72.73% and 68.18% of the STEC isolates. Twenty antibiotics were active against all the STEC isolates; all strains were resistant to penicillin G, and some to cephalothin or streptomycin. The 22 STEC isolates were divided into 16 PFGE patterns and 12 sequence types. Plateau pikas may play a role in the ongoing circulation of STEC in the Qinghai-Tibetan plateau. This study provides the first report on STEC in plateau pikas and new information about STEC reservoirs in wildlife. Based on the serotypes, virulence gene profiles and MLST analysis, the majority of these pika STECs may pose a low public health risk.

  17. The biogeography of soil archaeal communities on the eastern Tibetan Plateau (United States)

    Shi, Yu; Adams, Jonathan M.; Ni, Yingying; Yang, Teng; Jing, Xin; Chen, Litong; He, Jin-Sheng; Chu, Haiyan


    The biogeographical distribution of soil bacterial communities has been widely investigated. However, there has been little study of the biogeography of soil archaeal communities on a regional scale. Here, using high-throughput sequencing, we characterized the archaeal communities of 94 soil samples across the eastern Tibetan Plateau. Thaumarchaeota was the predominant archael phylum in all the soils, and Halobacteria was dominant only in dry soils. Archaeal community composition was significantly correlated with soil moisture content and C:N ratio, and archaeal phylotype richness was negatively correlated with soil moisture content (r = -0.47, P < 0.01). Spatial distance, a potential measure of the legacy effect of evolutionary and dispersal factors, was less important than measured environmental factors in determining the broad scale archaeal community pattern. These results indicate that soil moisture and C:N ratio are the key factors structuring soil archaeal communities on the eastern Tibetan Plateau. Our findings suggest that archaeal communities have adjusted their distributions rapidly enough to reach range equilibrium in relation to past environmental changes e.g. in water availability and soil nutrient status. This responsiveness may allow better prediction of future responses of soil archaea to environmental change in these sensitive ecosystems.

  18. Microplastic pollution of lakeshore sediments from remote lakes in Tibet plateau, China. (United States)

    Zhang, Kai; Su, Jing; Xiong, Xiong; Wu, Xiang; Wu, Chenxi; Liu, Jiantong


    Tibetan Plateau is known as the world's third pole, which is characterized by a low population density with very limited human activities. Tibetan Plateau possesses the greatest numbers of high-altitude inland lakes in the world. However, no information is currently available on the characteristic of microplastic pollution in those lakes within this remote area. In this work, lakeshore sediments from four lakes within the Siling Co basin in northern Tibet were sampled and examined for microplastics (Microplastics were detected in six out of seven sampling sites with abundances ranging from 8 ± 14 to 563 ± 1219 items/m(2). Riverine input might have contributed to the high abundance of microplastics observed in this remote area. Morphological features suggest that microplastics are derived from the breakdown of daily used plastic products. Polyethylene, polypropylene, polystyrene, polyethylene terephthalate, and polyvinyl chloride were identified from the microplastic samples using laser Raman spectroscopy, and oxidative and mechanical weathering textures were observed on the surface of microplastics using scanning electron microscope. These results demonstrate the presence of microplastics even for inland lakes in remote areas under very low human impact, and microplastic pollution can be a global issue. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Quadrant Dynamic with Automatic Plateau Limit Histogram Equalization for Image Enhancement

    Directory of Open Access Journals (Sweden)

    P. Jagatheeswari


    Full Text Available The fundamental and important preprocessing stage in image processing is the image contrast enhancement technique. Histogram equalization is an effective contrast enhancement technique. In this paper, a histogram equalization based technique called quadrant dynamic with automatic plateau limit histogram equalization (QDAPLHE is introduced. In this method, a hybrid of dynamic and clipped histogram equalization methods are used to increase the brightness preservation and to reduce the overenhancement. Initially, the proposed QDAPLHE algorithm passes the input image through a median filter to remove the noises present in the image. Then the histogram of the filtered image is divided into four subhistograms while maintaining second separated point as the mean brightness. Then the clipping process is implemented by calculating automatically the plateau limit as the clipped level. The clipped portion of the histogram is modified to reduce the loss of image intensity value. Finally the clipped portion is redistributed uniformly to the entire dynamic range and the conventional histogram equalization is executed in each subhistogram independently. Based on the qualitative and the quantitative analysis, the QDAPLHE method outperforms some existing methods in literature.

  20. Heat flow in the Ozark Plateau, Arkansas and Missouri: relationship to groundwater flow (United States)

    Meert, Joseph G.; Smith, Douglas L.; Fishkin, Len


    Heat flow values were calculated from direct measurements of temperature and thermal conductivity at thirteen sites in the Arkansas-Missouri Ozark Plateau region. These thirteen values are augmented by 101 estimates of heat flow, based on thermal conductivity measurements and temperature gradients extrapolated from bottom-hole temperatures. The regional heat flow profile ranges from 9 mW m -2 to over 80 mW m -2, but at least two distinct thermal regimes have been identified. Seven new heat flow determinations are combined with three previously published values for the St. Francois Mountains (SFM), a Precambrian exposure of granitic and rhyolitic basement rocks, average 47 mW m -2. Radioactive heat production of 76 samples of the exposed rocks in the SFM averages 2.4 μW m -2 and a typical continental basement contribution of 14 mW m -2 is implied. Conversely, the sedimentary rock sequence of the plateau is characterized by an anomalously low heat flow, averaging approximately 27 mW m -2. Groundwater transmissivity values that are based on data from 153 wells in deep regional aquifers demonstrate an inverse relationship to the observed heat flow patterns. The areas of high transmissivity that correspond to areas of low total heat flux suggest that the non-conservative vertical heat flow within the Ozark sedimentary sequence can be attributed to the effects of groundwater flow.

  1. Plateau-patella angle in evaluation of patellar height after total knee arthroplasty. (United States)

    Robin, Brett N; Ellington, Matthew D; Jupiter, Daniel C; Allen, Bryce C


    The plateau-patella angle (PPA) has been proposed as a new and simpler method to describe patellar height. This method has not been used or validated in knees following total knee arthroplasty (TKA). A modified PPA (mPPA) was developed for use in this population. The method was validated by determining the interobserver and intraobserver reliability of the technique in 50 consecutive patients compared to three well-described methods of describing patellar height after TKA. Three observers then evaluated the mPPA of 297 post-operative radiographs to describe a normal range after TKA for a given technique and implant. The interobserver reliability was the highest for the mPPA compared to the other methods. The mean mPPA for the entire cohort was 21.06, 20.49, and 19.94 for the three observers. The modified plateau-patella angle is a reliable way to evaluate patellar height in patients who have undergone total knee arthroplasty. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. [Soluble organic carbon in plant litters on Loess Plateau: content and biodegradability]. (United States)

    Wang, Chun-yang; Zhou, Jian-bin; Xia, Zhi-min; Chen, Xing-li


    The litters of eight plant species from the Loess Plateau were cut into pieces with 2 mm and 1 cm in size, and extracted with distilled water and 0.01 mol x L(-1) CaCl2 to determine the soluble organic carbon (SOC) content. In the meantime, a 7-day indoor incubation test was conducted at (25 +/- 3) degrees C to investigate their biodegradability. The SOC content and the ratio of SOC to total carbon (SOC/TC) in the litters were 18.20-156.82 g x kg(-1) and 4.21%-32.84%, respectively. Shrub litter had a slightly higher SOC content than tree litter, while grass litter had the lowest SOC content. After 7-day incubation, the biodegradation rate of SOC in the plant litters ranged from 44.5% to 80.6% (62.9% on average), and decreased in the order of shrub > tree > grass. By the end of the incubation, the proportion of soluble organic matter in solution had a significant increasing trend, which was related to the rapid biodegradation of labile composition in the litters. The higher content and higher biodegradation rate of SOC in plant litters might play important roles in nutrient cycling and energy flow during the vegetation restoration on Loess Plateau.

  3. Evapotranspiration Trend and Its Relationship with Precipitation over the Loess Plateau during the Last Three Decades

    Directory of Open Access Journals (Sweden)

    Zesu Yang


    Full Text Available There have been few studies conducted on the changes in actual ET over the Loess Plateau, due to the lack of reliable ET data. Based on ET data simulated by the Community Land Model, the present study analyzed the changes in ET over the Loess Plateau. The results showed the domain-average ET to have decreased in the past 31 years, at a rate of 0.78 mm year−1. ET fluctuated much more strongly in the 1990s than in the 1980s and 2000s, and, apart from in autumn, ET decreased in all seasons. In particular, ET in summer comprised about half of the annual ET trend and had the sharpest trend, dominating the interannual decline. ET also decreased more sharply in the semiarid than semihumid regions. The declining trend of ET was attributed to declining precipitation and air humidity. Locally, the ET trend was closely related to local mean annual precipitation: in areas with precipitation less than 400 mm, ET showed a decreasing trend; in areas with precipitation larger than 600 mm, ET showed an increasing trend; and in areas with precipitation in the range of 400–600 mm could be classified as a transitional zone.

  4. Elementary particle physics and high energy phenomena. [Dept. of Physics, Univ. of Colorado, Boulder, Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Barker, A.R.; Cumalat, J.P.; De Alwis, S.P.; DeGrand, T.A.; Ford, W.T.; Mahanthappa, K.T.; Nauenberg, U.; Rankin, P.; Smith, J.G.


    Experimental and theoretical high-energy physics programs at the University of Colorado are reported. Areas of concentration include the following: study of the properties of the Z[sup 0] with the SLD detector; fixed-target K-decay experiments; the R D program for the muon system: the SDC detector; high-energy photoproduction of states containing heavy quarks; electron--positron physics with the CLEO II detector at CESR; lattice QCD; and spin models and dynamically triangulated random surfaces. 24 figs., 2 tabs., 117 refs.

  5. Active shortening and intermontane basin formation in the central Puna Plateau: Salar de Pocitos, NW Argentina (24°37'S, 67°03'W) (United States)

    Strecker, Manfred; Bookhagen, Bodo; Freymark, Jessica; Pingel, Heiko; Alonso, Ricardo N.


    Similar to other Cenozoic orogenic plateaus, extensional tectonics associated with mafic volcanism typifies the Altiplano-Puna of the southern Central Andes, while the flanks of the plateau and adjacent foreland areas experience shortening. Extensional tectonism in the plateau region since the late Miocene has been explained with delamination of lithospheric mantle. However, new evidence for protracted basin-wide shortening in the Salar de Pocitos region in the south-central Puna documents that the kinematic changeover from shortening to extension is highly diachronous. In this study we assess the deformation and geomorphic history of the Salar de Pocitos region using DGPS surveys, CRN dating of deformed pediment surfaces, and U/Pb dating of volcanic ash horizons in deformed strata. With average elevations of about 3.7 km the Altiplano-Puna is a first-order morphotectonic province of the southern central Andes and constitutes the world's second largest orogenic plateau. With few exceptions the Andean plateau consists of internally drained, partly coalesced sedimentary basins that are mainly bordered by reverse-fault bounded ranges, 5 to 6 km high. While there are many unifying plateau characteristics in the Altiplano (north) and Puna (south), including internal drainage, semi-arid to arid climate and associated deposition of evaporites, there are notable differences between both plateau sectors. In contrast to the vast Altiplano basin of Bolivia, the Argentine Puna comprises numerous, smaller and partly coalesced basins that reflect continued comparmentalization by the combined effects of tectonism and volcanic activity. The N-S oriented Salar de Pocitos basin is the vestige of a formerly contiguous sedimentary basin within the Puna interior. Unlike many other basins in this region it is bordered by the limb of an anticline developed in Tertiary sedimentary rocks on the west, while the eastern border is a reverse-faulted range front. To the north and south the

  6. Puente Río Colorado - Costa Rica

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    Kulka, F.


    Full Text Available The Colorado River bridge is located in a 95 m deep canyon, with a 122 m span. To choose the type of bridge, it has been endeavoured to use the largest possible number of national building materials which, together with the difficulty of reaching the site, meant that a series of classical solutions had to be rejected. That of an arch bridge was adopted, with a reversed support on prestressed cables, on which the road passes. The system is based on the hanging bridge principle, but with the rolling track resting on the cables, instead of hanging from them. There is a first cover, made up of prefabricated components, on the cables, which strengthens the bridge's stability. This cover supports three portal-columns, the pillars of the final roadway. The cables were prestressed from the heads of the two sloping pillars. The two side spans were designed with prefabricated T girders.El puente Río Colorado está situado en un cañón de 95 m de profundidad, salvando una luz de 122 m. Para la elección del tipo de puente se ha procurado emplear el mayor número posible de materiales de construcción nacionales, lo que, unido a la dificultad de acceso a la obra, hizo que se rechazaran una serie de soluciones clásicas. Se adoptó la de un puente-arco con un soporte invertido sobre cables pretensados, encima del cual descansa la calzada. El sistema está basado en los principios del puente colgante, pero apoyando el camino de rodadura en los cables, en lugar de colgarlo de ellos. Sobre los cables existe una primera cubierta, integrada por elementos prefabricados, que refuerza la estabilidad del puente. Esta cubierta soporta tres pórticos-columna, pilares de la calzada definitiva. El pretensado de los cables se realizó desde las cabezas de dos pilares inclinados. Los dos vanos laterales se proyectaron con vigas en T prefabricadas.

  7. Persistence of Carbonate Platform Environments in Central Mexico during the Oceanic Anoxic Event 2: impact of the Carribean Plateau? (United States)

    Bomou, Brahimsamba; Adatte, Thierry; Föllmi, Karl; Arnaud-Vanneau, Annie; Fleitmann, Dominik


    The Cenomanian-Turonian Oceanic Anoxic Event 2 is described as an interruption of normal pelagic sediment deposition by several distinct intervals of widespread oceanic anoxia (Schlanger & Jenkyns, 1976; Jenkyns, 1980; Arthur et al., 1990) characterized by black shales deposition coinciding with a positive shift in carbon isotope excursion. Some authors show a relationship between OAEs and massive volcanic events associated with the emplacement of large igneous provinces (LIPs) and sea floor spreading at mid-ocean ridges (Kuroda et al., 2007; Snow et al., 2005). High metal abundance anomalies recorded in pelagic sections (e.g. Pueblo, Colorado) coincide with the massive volcanism that built the Carribean plateau (around 93-94 Ma), associated with the onset of OAE 2 (Snow et al., 2005). Mort et al., (2007) demonstrate that the onset of the OAE 2 was triggered by a short-lived but significant increase in phosphorus burial. The bottom waters became anoxic and switched from being a P sink to a P source, sustaining the productivity in a positive feedback loop. However, the behaviour of phosphorus and trace metals at larger scale, in different paleogeography and paleodepht is still poorly known. The Axaxacualco and Baranca el Cañon sections, located at the Guerrero-Morelos carbonate platform in southern Mexico exhibit a fully correlateable d13C curves. In the distal part of the carbonate platform at Axaxacualco, the maximum d13C positive excursion coincides with oligotrophic carbonate platform environments supported by low concentrations in P and characterized by abundant and diversified benthic microfauna and rudists. The impact of OAE appears may be more significant in the proximal part of the carbonate platform at Barranca, characterized by the deposition of thick laminated microbialites indicative of mesotrophic conditions. The Morelos Carbonate platform with oligotrophic to mesotrophic conditions was persistent throughout the entire OAE2 in Central Mexico despite

  8. Exploring the undulating plateau: the future of global oil supply. (United States)

    Jackson, Peter M; Smith, Leta K


    In this paper, we analyse the factors that will influence long-term oil supply and describe the future form of the global oil supply profile as an 'undulating plateau' rather than an irreversible, short-term peak or an ever upward trend of increasing production. The ultimate transition from a world of relatively plentiful and cheap oil to one of tight supply and high cost will be slow and challenging. An understanding of the signposts for the future path of supply and the drivers of that profile will be critical to managing the transition. The ultimate form of the global supply curve may well be dictated by demand evolution rather than a limited resource endowment in the longer term. Several factors will probably control future global oil supply. We believe that the scale of global oil resource will not constitute a physical supply limit for at least the next two or three decades. However, all categories of oil resources are already more expensive to develop than in the past, requiring high oil prices to stimulate supply growth. Lower rates of oil demand growth relative to economic growth, combined with more challenging supply growth, will probably lead to an undulating plateau sometime after 2040, with demand from non-Organization for Economic Cooperation and Development states continuing to dominate. Upstream investment requirements and oil price volatility will increase towards and beyond the undulating production plateau. In this new world, high oil prices will induce demand destruction, fuel substitution and ever increasing energy efficiency. As we discuss below, the fundamental differences between the IHS Cambridge Energy Research Associates' (IHS CERA) view of the future of oil supply and many peak oil supply models are the timing of the onset of a dramatic slowdown in the rate of growth of supply and the existence or otherwise of a production plateau. We do not dispute that supply will plateau and eventually fall; the question is when, how and at what price

  9. High pre-industrial and modern Tibetan Plateau fire activity (United States)

    Kehrwald, N. M.; Li, Q.; Wang, N.; Zennaro, P.; Zangrando, R.; Barbante, C.


    The South Asian brown cloud created from a mix of biomass burning and fossil fuel aerosols is warming the atmosphere between 5000 to 7000 meters above sea level (m asl) along the southern slope of the Himalaya. The extent to which this atmospheric brown cloud is transported up and over the 7000 to 8000 m asl ridge of the Himalaya and northward across the Tibetan Plateau is unknown. Intense Eastern Asian industry and associated coal burning may also export fossil fuel burning products to the Tibetan Plateau. In addition, local cooking, agricultural and natural fires emit combustion products that alter atmospheric chemistry and are deposited on glacier surfaces. It is essential to differentiate between the effects of fossil fuel and biomass burning across the Tibetan Plateau to determine if combustion products affect glacier surfaces and, by extension, glacier volume. The specific biomarker levoglucosan can only be produced by biomass burning at temperatures of 300°C or higher and is trapped and preserved in glaciers across the globe. This specificity may allow the possibility of differentiating between fossil fuel and biomass burning contributions when comparing levoglucosan concentrations with more general ice core combustion proxies such as black carbon. Here, we present a biomass burning record from the entire 164 m Muztag ice core (36.35°N; 87.17°E; 5780 m asl) and from a southwest to northeast transect of snow pits across the Tibetan Plateau. Multiple total organic carbon and dissolved organic carbon surface samples demonstrate organic carbon concentrations at or near detection limits. However, these samples have high levoglucosan concentrations suggesting that the biomass burning recorded in these sites may be from a regional rather than local source. The Tibetan Plateau levoglucosan concentrations are surprisingly substantially greater than Kilimanjaro levoglucosan concentrations, where Kilimanjaro is located in a relatively similar low-latitude high

  10. [The pathogenic ecology research on plague in Qinghai plateau]. (United States)

    Dai, Rui-xia; Wei, Bai-qing; Li, Cun-xiang; Xiong, Hao-ming; Yang, Xiao-yan; Fan, Wei; Qi, Mei-ying; Jin, Juan; Wei, Rong-jie; Feng, Jian-ping; Jin, Xing; Wang, Zu-yun


    To study the pathogenic ecology characteristics of plague in Qinghai plateau. Applied molecular biology techniques, conventional technologies and geographic information system (GIS) to study phenotypic traits, plasmid spectrum, genotype, infected host and media spectrum etc.of 952 Yersinia pestis strains in Qinghai plateau plague foci, which were separated from different host and media in different regions during 1954 to 2012. The ecotypes of these strains were Qingzang plateau (91.49%, 871/952),Qilian mountain (6.41%, 61/952) and Microtus fuscus (1.26%, 12/952).83.6% (796/952) of these strains contained all the 4 virulence factors (Fr1, Pesticin1,Virulence antigen, and Pigmentation), 93.26% (367/392) were velogenic strains confirmed by virulence test.725 Yersinia pestis strains were separated from Qinghai plateau plague foci carried 9 kinds of plasmid, among which 713 strains from Marmot himalayan plague foci carried 9 kinds of plasmid, the Mr were 6×10(6), 7×10(6), 23×10(6), 27×10(6), 30×10(6), 45×10(6), 52×10(6), 65×10(6) and 92×10(6) respectively. 12 Yersinia pestis strains were separated from Microtus fuscus plague foci carried only 3 kinds of plasmid, the Mr were 6×10(6), 45×10(6), 65×10(6). Meanwhile, the strains carrying large plasmid (52×10(6), 65×10(6) and 92×10(6)) were only distributed in particular geographical location, which had the category property. The research also confirmed that 841 Yersinia pestis strains from two kinds of plague foci in Qinghai plateau had 11 genomovars. The strains of Marmot himalayan plague foci were given priority to genomovar 5 and 8, amounted to 611 strains, genomovar 8 accounted for 56.00% (471/841), genomovar 5 accounted for 23.07% (194/841). Besides, 3 new genomovars, including new 1(62 strains), new 2(52 strains), new 3(48 strains) were newly founded, and 12 strains of Microtus fuscus plague foci were genomovar 14. The main host and media of Qinghai plateau plague foci directly affected the spatial

  11. University of Colorado, Nuclear Physics Laboratory technical progress report, November 1, 1978-October 31, 1979. Report NPL-845. [Nuclear Physics Lab. , Univ. of Colorado

    Energy Technology Data Exchange (ETDEWEB)


    This report summarizes work carried out at the Nuclear Physics Laboratory of the University of Colorado from November 1, 1978 to October 31, 1979, under contract EY-76-C-02-0535.A003 between the University of Colorado and the United States Department of Energy. Experimental studies of light ion-induced reactions were performed with the AVF cyclotron, which continues each year to produce beams of yet higher quality. Charged-particle studies continued to emphasize use of the high-resolution spectrometer system, but some return to broad-range spectroscopic studies using solid state detectors also occurred. Neutron time-of-flight experiments used 9-meter and 30-meter flight paths. Neutron-gamma ray coincidence studies developed into a new and promising field. The new PDP 11/34 data acquisition system was of great value in allowing such multiparameter experiments. Smaller programs in nuclear astrophysics, plasma diagnostic development, and medical physics were also undertaken. Research activities based at other accelerators grew. Studies of future directions for light-ion accelerators, including work on intense pulsed ion sources, orbit dynamics, and storage rings, were greatly enlarged. 19 of the articles in this report were abstracted and indexed individually. Lists of publications and personnel conclude this report. (RWR)

  12. Evidence for an abrupt climatic reversal during the Last Interglacial on the northeast Qinghai-Tibetan Plateau

    NARCIS (Netherlands)

    Lu, H.; Vandenberghe, J.; Miao, X.; Tan, H.; Ma, H.


    Climatic change over Qinghai-Tibetan Plateau is controlled by alternation of the plateau summer and winter monsoon circulation, which is triggered by thermodynamic and kinetic effects of the high plateau morphology. Loess-paleosol sequences in northeast Qinghai-Tibetan Plateau are investigated to

  13. Vegetation map of the greater Denver area, Front Range urban corridor, Colorado (United States)

    Marr, J.W.; Boyd, W.S.


    Vegetation is one of our most valuable renewable resources; it is the primary producer of organic matter on which all nongreen organisms are dependent for energy, construction materials, aesthetic enjoyment, and other necessities of life. In order to secure the greatest possible returns from the utilization of the different types of vegetation, people need to know what species are present, the ecological processes in which they are involved, and the ways in which they are arranged in the landscape. This vegetation map is designed to help persons in a wide variety of activities to secure that information.

  14. Rehabilitating slash pile burn scars in upper montane forests of the Colorado Front Range (United States)

    Paula J. Fornwalt; Charles C. Rhoades


    Slash pile burning is widely conducted by land managers to dispose of unwanted woody fuels, yet this practice typically has undesirable ecological impacts. Simple rehabilitation treatments may be effective at ameliorating some of the negative impacts of pile burning on plants and soils. Here, we investigated: (1) the impacts of slash pile burning on soil nitrogen and...

  15. Hedonic valuation with translating amenities: Mountain Pine Beetles and host trees in the Colorado Front Range (United States)

    Jed Cohen; Christine E. Blinn; Kevin J. Boyle; Tom Holmes; Klaus Moeltner


    In hedonic valuation studies the policy-relevant environmental quality attribute of interest is often costly to measure, especially under pronounced spatial and temporal variability. However, in many cases this attribute affects home prices and consumer preferences solely through its impact on a readily observable, spatially delineated, and time-invariant feature of...

  16. Historical (1860) forest structure in ponderosa pine forests of the northern Front Range, Colorado (United States)

    Peter M. Brown; Michael A. Battaglia; Paula J. Fornwalt; Benjamin Gannon; Laurie S. Huckaby; Chad Julian; Antony S. Cheng


    Management of many dry conifer forests in western North America is focused on promoting resilience to future wildfires, climate change, and land use impacts through restoration of historical patterns of forest structure and disturbance processes. Historical structural data provide models for past resilient conditions that inform the design of silvicultural treatments...

  17. Birth outcomes in Colorado's undocumented immigrant population

    Directory of Open Access Journals (Sweden)

    Battaglia Catherine


    Full Text Available Abstract Background The birth outcomes of undocumented women have not been systematically studied on a large scale. The growing number of undocumented women giving birth in the United States has important implications for clinical care and public health policy. The objective of this study was to describe birth outcomes of undocumented immigrants in Colorado. Methods Retrospective descriptive study of singleton births to 5961 undocumented women using birth certificate data for 1998–1999. Results Undocumented mothers were younger, less educated, and more likely to be single. They had higher rates of anemia, were less likely to gain enough weight, and less likely to receive early prenatal care. They were much less likely to use alcohol or tobacco. Undocumented women had a lower rate of low birth weight (5.3% v 6.5%, P Conclusion Undocumented women have lower rates of preterm delivery and low birth weight infants, but higher rates of pregnancy related risk factors. Higher prevalence of some risk factors which are amenable to medical intervention reveals the need for improved prenatal care in this group.

  18. Preliminary Site Characterization Report, Rulsion Site, Colorado

    Energy Technology Data Exchange (ETDEWEB)



    This report is a summary of environmental information gathered during a review of the documents pertaining to Project Rulison and interviews with personnel who worked on the project. Project Rulison was part of Operation Plowshare (a program designed to explore peaceful uses for nuclear devices). The project consisted of detonating a 43-kiloton nuclear device on September 10, 1969, in western Colorado to stimulate natural gas production. Following the detonation, a reentry well was drilled and several gas production tests were conducted. The reentry well was shut-in after the last gas production test and was held in standby condition until the general cleanup was undertaken in 1972. A final cleanup was conducted after the emplacement and testing wells were plugged in 1976. However, some surface radiologic contamination resulted from decontamination of the drilling equipment and fallout from the gas flaring during drilling operations. With the exception of the drilling effluent pond, all surface contamination at the Rulison Site was removed during the cleanup operations. All mudpits and other excavations were backfilled, and both upper and lower drilling pads were leveled and dressed. This report provides information regarding known or suspected areas of contamination, previous cleanup activities, analytical results, a review of the regulatory status, the site`s physical environment, and future recommendations for Project Ruhson. Based on this research, several potential areas of contamination have been identified. These include the drilling effluent pond and mudpits used during drilling operations. In addition, contamination could migrate in the gas horizon.

  19. Cost-Effectiveness Analysis of the Residential Provisions of the 2015 IECC for Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Mendon, Vrushali V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zhao, Mingjie [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Taylor, Zachary T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Poehlman, Eric A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)


    The 2015 IECC provides cost-effective savings for residential buildings in Colorado. Moving to the 2015 IECC from the 2009 IECC base code is cost-effective for residential buildings in all climate zones in Colorado.

  20. Good Days on the Trail, 1938-1942: Film Footage of the Rocky Mountains, Colorado (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This film documents student hiking trips conducted by the University of Colorado at Boulder in the Rocky Mountains, Colorado, USA during the summers of 1938-1942....