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Sample records for alaskan yukon river

  1. Spatial variability and landscape controls of near-surface permafrost within the Alaskan Yukon River Basin

    Science.gov (United States)

    Pastick, Neal J.; Jorgenson, M. Torre; Wylie, Bruce K.; Rose, Joshua R.; Rigge, Matthew; Walvoord, Michelle A.

    2014-01-01

    The distribution of permafrost is important to understand because of permafrost's influence on high-latitude ecosystem structure and functions. Moreover, near-surface (defined here as within 1 m of the Earth's surface) permafrost is particularly susceptible to a warming climate and is generally poorly mapped at regional scales. Subsequently, our objectives were to (1) develop the first-known binary and probabilistic maps of near-surface permafrost distributions at a 30 m resolution in the Alaskan Yukon River Basin by employing decision tree models, field measurements, and remotely sensed and mapped biophysical data; (2) evaluate the relative contribution of 39 biophysical variables used in the models; and (3) assess the landscape-scale factors controlling spatial variations in permafrost extent. Areas estimated to be present and absent of near-surface permafrost occupy approximately 46% and 45% of the Alaskan Yukon River Basin, respectively; masked areas (e.g., water and developed) account for the remaining 9% of the landscape. Strong predictors of near-surface permafrost include climatic indices, land cover, topography, and Landsat 7 Enhanced Thematic Mapper Plus spectral information. Our quantitative modeling approach enabled us to generate regional near-surface permafrost maps and provide essential information for resource managers and modelers to better understand near-surface permafrost distribution and how it relates to environmental factors and conditions.

  2. Distribution and landscape controls of organic layer thickness and carbon within the Alaskan Yukon River Basin

    Science.gov (United States)

    Pastick, Neal J.; Rigge, Matthew B.; Wylie, Bruce K.; Jorgenson, M. Torre; Rose, Joshua R.; Johnson, Kristofer D.; Ji, Lei

    2014-01-01

    Understanding of the organic layer thickness (OLT) and organic layer carbon (OLC) stocks in subarctic ecosystems is critical due to their importance in the global carbon cycle. Moreover, post-fire OLT provides an indicator of long-term successional trajectories and permafrost susceptibility to thaw. To these ends, we 1) mapped OLT and associated uncertainty at 30 m resolution in the Yukon River Basin (YRB), Alaska, employing decision tree models linking remotely sensed imagery with field and ancillary data, 2) converted OLT to OLC using a non-linear regression, 3) evaluate landscape controls on OLT and OLC, and 4) quantified the post-fire recovery of OLT and OLC. Areas of shallow (2 = 0.68; OLC: R2 = 0.66), where an average of 16 cm OLT and 5.3 kg/m2 OLC were consumed by fires. Strong predictors of OLT included climate, topography, near-surface permafrost distributions, soil wetness, and spectral information. Our modeling approach enabled us to produce regional maps of OLT and OLC, which will be useful in understanding risks and feedbacks associated with fires and climate feedbacks.

  3. Impacts of Soil Temperature and Moisture Change on Soil Carbon Dynamics in the Alaskan Yukon River Basin - From the Perspective of Vertical Distribution

    Science.gov (United States)

    Tao, B.; Liu, S.; Tan, Z.; Tieszen, L.; Hansen, M.

    2008-12-01

    Boreal ecosystems are experiencing rapid climate change and land surface disturbances (e.g., fires and insect outbreaks), which have triggered substantial changes in ecosystem structure and functions, biogeochemical cycle, and land surface processes. These changes in turn have major implications to the changes of regional and climate systems. There is an urgent need to develop robust process-based land surface modeling systems that can simulate the responses of many poorly understood but fast-changing soil processes in the region. In this study, we improved the soil physics module in the Erosion-Deposition-Carbon Model (EDCM), mainly following the algorithms in the Integrated BIosphere Simulator (IBIS), to simulate historical and future changes of soil temperature, moisture, active layer thickness, permafrost depth, and their impacts on organic layer and soil carbon dynamics from two boreal forest sites in the Alaskan Yukon River Basin. We used a multi-snow-soil-layer model structure to represent the vertical profiles of soil properties and processes. Our results showed more soil carbon emission than the single-soil-layer models predicted under future climate change scenarios. A multi-soil-layer model has to be used in the northern high latitudes to predict the fate of deep soil organic matter, organic layer thickness, and degradation of permafrost. At the site scale, major uncertainties for model development and characterization of the responses of vegetation and soils to future climate change include vegetation succession, transitional vegetation rooting depth change, root mortality, and fire intensity and frequency. Additional intensive site studies and remote sensing research have to be conducted to address some of the uncertainties in order to apply the model at the regional scale.

  4. An integrated Dissolved Organic Carbon Dynamics Model (DOCDM 1.0): model development and a case study in the Alaskan Yukon River Basin

    Science.gov (United States)

    Lu, X.; Zhuang, Q.

    2015-12-01

    Quantitative understanding of the variation in dissolved organic carbon (DOC) is important to studying the terrestrial ecosystem carbon cycle. This study presents a process-based, dissolved organic carbon dynamics model (DOCDM 1.0) that couples the soil heat conduction, water flow, DOC production, mineralization and transport in both surface and subsurface of soil profile to quantify DOC dynamics in boreal terrestrial ecosystems. The model is first evaluated and then applied for a watershed in Alaska to investigate its DOC production and transport. We find that 42 and 27 % of precipitation infiltrates to soils in 2004, a warmer year, and in 1976, a colder year, respectively. Under warming conditions, DOC transported via overland flow does not show the expected decrease trend while the overland DOC yield shows a 4 % increase. The horizontal subsurface flow only accounts for 1-2 % of total water flux, but transports 30-50 % of DOC into rivers. Water flush due to water infiltration controls DOC transport. Snowmelt plays a noticeable role in DOC flush-out and DOC transport significantly depends on flowpaths in the study region. High soil temperature stimulates DOC production. The overland DOC export does not necessarily follow the DOC downward trend in surface water transport. Overall, this study shows that DOC export behavior is complex under changing temperature and hydrological conditions in cold-region watersheds. To adequately quantify DOC dynamics in northern high latitudes, more DOC and hydrological data are needed to better parameterize and test the developed model before extrapolating it to the region.

  5. AFSC/ABL: Movements of Yukon River Chinook salmon

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Upriver movements were determined for Chinook salmon Oncorhynchus tshawytscha returning to the Yukon River, a large, relatively pristine river basin. A total of...

  6. Carbon dioxide and methane emissions from the Yukon River system

    Science.gov (United States)

    Striegl, Rob; Dornblaser, Mark M.; McDonald, Cory P.; Rover, Jennifer R.; Stets, Edward G.

    2012-01-01

    Carbon dioxide (CO2) and methane (CH4) emissions are important, but poorly quantified, components of riverine carbon (C) budgets. This is largely because the data needed for gas flux calculations are sparse and are spatially and temporally variable. Additionally, the importance of C gas emissions relative to lateral C exports is not well known because gaseous and aqueous fluxes are not commonly measured on the same rivers. We couple measurements of aqueous CO2 and CH4 partial pressures (pCO2, pCH4) and flux across the water-air interface with gas transfer models to calculate subbasin distributions of gas flux density. We then combine those flux densities with remote and direct observations of stream and river water surface area and ice duration, to calculate C gas emissions from flowing waters throughout the Yukon River basin. CO2emissions were 7.68 Tg C yr−1 (95% CI: 5.84 −10.46), averaging 750 g C m−2 yr−1 normalized to water surface area, and 9.0 g C m−2 yr−1 normalized to river basin area. River CH4 emissions totaled 55 Gg C yr−1 or 0.7% of the total mass of C emitted as CO2 plus CH4 and ∼6.4% of their combined radiative forcing. When combined with lateral inorganic plus organic C exports to below head of tide, C gas emissions comprised 50% of total C exported by the Yukon River and its tributaries. River CO2 and CH4 derive from multiple sources, including groundwater, surface water runoff, carbonate equilibrium reactions, and benthic and water column microbial processing of organic C. The exact role of each of these processes is not yet quantified in the overall river C budget.

  7. Multidecadal increases in the Yukon River Basin of chemical fluxes as indicators of changing flowpaths, groundwater, and permafrost

    Science.gov (United States)

    Toohey, R. C.; Herman-Mercer, N. M.; Schuster, P. F.; Mutter, E. A.; Koch, J. C.

    2016-12-01

    The Yukon River Basin, underlain by discontinuous permafrost, has experienced a warming climate over the last century that has altered air temperature, precipitation, and permafrost. We investigated a water chemistry database from 1982 to 2014 for the Yukon River and its major tributary, the Tanana River. Significant increases of Ca, Mg, and Na annual flux were found in both rivers. Additionally, SO4 and P annual flux increased in the Yukon River. No annual trends were observed for dissolved organic carbon (DOC) from 2001 to 2014. In the Yukon River, Mg and SO4 flux increased throughout the year, while some of the most positive trends for Ca, Mg, Na, SO4, and P flux occurred during the fall and winter months. Both rivers exhibited positive monthly DOC flux trends for summer (Yukon River) and winter (Tanana River). These trends suggest increased active layer expansion, weathering, and sulfide oxidation due to permafrost degradation throughout the Yukon River Basin.

  8. Mercury interferes with endogenous antioxidant levels in Yukon River subsistence-fed sled dogs

    Science.gov (United States)

    Dunlap, Kriya L.; Reynolds, Arleigh J.; Gerlach, S. Craig; Duffy, Lawrence K.

    2011-10-01

    Before adopting modern corn-and-grain-based western processed diets, circumpolar people had a high fat and protein subsistence diet and exhibited a low incidence of obesity, diabetes and cardiovascular disease. Some health benefits are attributable to a subsistence diet that is rich in omega-3 fatty acids and antioxidants. Pollution, both global and local, is a threat to wild foods, as it introduces contaminants into the food system. Northern indigenous people and their sled dogs are exposed to a variety of contaminants, including mercury, that accumulate in the fish and game that they consume. The sled dogs in Alaskan villages are maintained on the same subsistence foods as their human counterparts, primarily salmon, and therefore they can be used as a food systems model for researching the impact of changes in dietary components. In this study, the antioxidant status and mercury levels were measured for village sled dogs along the Yukon River. A reference kennel, maintained on a nutritionally balanced commercial diet, was also measured for comparison. Total antioxidant status was inversely correlated with the external stressor mercury.

  9. Bryophytes from the area drained by the Peel and Mackenzie Rivers, Yukon and Northwest Territories, Canada

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report is on bryophytes from the area drained by the Peel and Mackenzie rivers in the Yukon territory of Canada. The distribution and general ecology of 263...

  10. Geochemistry of yukon and copper river tributaries, Alaska

    Science.gov (United States)

    Carney, M.; Ellis, A.; Bullen, T.; Langman, J.

    2009-01-01

    Alaska is already beginning to be affected by changes in global climate which make it a good location to study the feedback effects between climate, the water cycle and the carbon cycle. Using river dissolved elements and Sr isotopes we examine changes and/or differences in chemical weathering between watersheds in predominantly permafrost areas and glacial watersheds. Tributaries of the Tanana, Yukon, Nenana and Copper rivers were sampled during the early snow melt in late May and the late permafrost/glacial melt period in September of 2007. Waters are predominantly CaHCO3-/SO4 which is typical of glaciated terrains. 87Sr/86Sr isotopes indicate three potential end-members, young basalts, radiogenic silicates and marine carbonates. The results are consistent with weathering observed in glaciated regions with trace calcites and salts dominating the dissolved load; however we have evidence for silicate weathering. Results also indicate that permafrost watersheds experience more progressive silicate weathering than glacial watersheds. ??2009 ASCE.

  11. A Yukon River Basin Landsat Mosaic for Assessing Environmental Change

    Science.gov (United States)

    Bouchard, M. A.; Dwyer, J. L.; Granneman, B.

    2009-12-01

    Landsat data from the Global Land Survey (GLS) dataset for year 2000 was mosaicked to form a Yukon River Basin image map that is referenced to a geodetic base. It was produced from 66 Landsat-7 Enhanced Thematic Mapper Plus (ETM+) images collected from 1999-2002. Two products were created: (1) a geographically referenced database containing all seven of the spectral bands for the individual scenes and (2) a 3-band (shortwave infrared, near-infrared, and green - 7,4,2) radiometrically normalized shaded relief image map using the U.S. Geological Survey National Elevation Dataset and Canadian Digital Elevation Data from Natural Resources Canada. The science data product will facilitate studies to map the extent of snow, ice and surface water at a basin-wide scale. Focused studies on snow/ice transitions for selected glaciers will be conducted in order to establish accumulation ratios for use in future monitoring. The mosaic also shows the complex patterns of wildfires in the interior forests and the diversity of ecosystems throughout the basin. The shaded relief product image mosaic is a reference map for reconnaissance studies as well as a geographic framework within which to spatially integrate project-wide data and information.

  12. Ecology of invasive Melilotus albus on Alaskan glacial river floodplains

    Science.gov (United States)

    Conn, Jeff S.; Werdin-Pfisterer, Nancy R.; Beattie, Katherine L.; Densmore, Roseann V.

    2011-01-01

    Melilotus albus (white sweetclover) has invaded Alaskan glacial river floodplains. We measured cover and density of plant species and environmental variables along transects perpendicular to the Nenana, Matanuska, and Stikine Rivers to study interactions between M. albus and other plant species and to characterize the environment where it establishes. Melilotus albus was a pioneer species on recently disturbed sites and did not persist into closed canopy forests. The relationships between M. albus cover and density and other species were site-specific.Melilotus albus was negatively correlated with native species Elaeagnus commutata at the Nenana River, but not at the Matanuska River. Melilotus albus was positively correlated with the exotic species Crepis tectorumand Taraxacum officinale at the Matanuska River and T. officinale on the upper Stikine River. However, the high density of M. albus at a lower Stikine River site was negatively correlated with T. officinale and several native species including Lathyrus japonicus var. maritimus and Salix alaxensis. Glacial river floodplains in Alaska are highly disturbed and are corridors for exotic plant species movement. Melilotus albus at moderate to low densities may facilitate establishment of exotic species, but at high densities can reduce the cover and density of both exotic and native species.

  13. Middle to Late Pleistocene ice extents, tephrochronology and paleoenvironments of the White River area, southwest Yukon

    Science.gov (United States)

    Turner, Derek G.; Ward, Brent C.; Bond, Jeffrey D.; Jensen, Britta J. L.; Froese, Duane G.; Telka, Alice M.; Zazula, Grant D.; Bigelow, Nancy H.

    2013-09-01

    Sedimentary deposits from two Middle to Late Pleistocene glaciations and intervening non-glacial intervals exposed along the White River in southwest Yukon, Canada, provide a record of environmental change for much of the past 200 000 years. The study sites are beyond the Marine Isotope stage (MIS) 2 glacial limit, near the maximum regional extent of Pleistocene glaciation. Non-glacial deposits include up to 25 m of loess, peat and gravel with paleosols, pollen, plant and insect macrofossils, large mammal fossils and tephra beds. Finite and non-finite radiocarbon dates, and twelve different tephra beds constrain the chronology of these deposits. Tills correlated to MIS 4 and 6 represent the penultimate and maximum Pleistocene glacial limits, respectively. The proximity of these glacial limits to each other, compared to limits in central Yukon, suggests precipitation conditions were more consistent in southwest Yukon than in central Yukon during the Pleistocene. Conditions in MIS 5e and 5a are recorded by two boreal forest beds, separated by a shrub birch tundra, that indicate environments as warm or warmer than present. A dry, treeless steppe-tundra, dominated by Artemisia frigida, upland grasses and forbs existed during the transition from late MIS 3 to early MIS 2. These glacial and non-glacial deposits constrain the glacial limits and paleoenvironments during the Middle to Late Pleistocene in southwest Yukon.

  14. Asbestos investigations in fish and wildlife in the upper Yukon River region, Alaska 1977-1982: Summary

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — High Concentrations of asbestos were first discovered in the upper Yukon River near Eagle, Alaska in the summer of 1977 by Fish and Wildlife Service Biologists....

  15. Yukon Delta and Togiak National Wildlife Refuges Comprehensive Conservation Plan, Environmental Impact Statement, Wilderness Review, and Wild River Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is the Final Comprehensive Conservation Plan, Environmental Impact Statement, Wilderness Review, and Wild River Plan (CCP/EIS/WR/WRP) for the Yukon...

  16. Spectacled Eiders (Somateria fischeri) capture and resight records, Kashunuk River, Yukon-Kuskokwim Delta, Alaska, 1995-2002

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Data set containing capture and band resight data associated with marked Spectacled Eiders, observed near the Kashunuk River, within the Yukon-Kuskokwim Delta, Alaska.

  17. Pleistocene vertebrates of the Yukon Territory

    Science.gov (United States)

    Harington, C. R.

    2011-08-01

    Unglaciated parts of the Yukon constitute one of the most important areas in North America for yielding Pleistocene vertebrate fossils. Nearly 30 vertebrate faunal localities are reviewed spanning a period of about 1.6 Ma (million years ago) to the close of the Pleistocene some 10 000 BP (radiocarbon years before present, taken as 1950). The vertebrate fossils represent at least 8 species of fishes, 1 amphibian, 41 species of birds and 83 species of mammals. Dominant among the large mammals are: steppe bison ( Bison priscus), horse ( Equus sp.), woolly mammoth ( Mammuthus primigenius), and caribou ( Rangifer tarandus) - signature species of the Mammoth Steppe fauna ( Fig. 1), which was widespread from the British Isles, through northern Europe, and Siberia to Alaska, Yukon and adjacent Northwest Territories. The Yukon faunas extend from Herschel Island in the north to Revenue Creek in the south and from the Alaskan border in the west to Ketza River in the east. The Yukon holds evidence of the earliest-known people in North America. Artifacts made from bison, mammoth and caribou bones from Bluefish Caves, Old Crow Basin and Dawson City areas show that people had a substantial knowledge of making and using bone tools at least by 25 000 BP, and possibly as early as 40 000 BP. A suggested chronological sequence of Yukon Pleistocene vertebrates ( Table 1) facilitates comparison of selected faunas and indicates the known duration of various taxa.

  18. Using a Genetic mixture model to study Phenotypic traits: Differential fecundity among Yukon river Chinook Salmon

    Science.gov (United States)

    Bromaghin, J.F.; Evenson, D.F.; McLain, T.H.; Flannery, B.G.

    2011-01-01

    Fecundity is a vital population characteristic that is directly linked to the productivity of fish populations. Historic data from Yukon River (Alaska) Chinook salmon Oncorhynchus tshawytscha suggest that length-adjusted fecundity differs among populations within the drainage and either is temporally variable or has declined. Yukon River Chinook salmon have been harvested in large-mesh gill-net fisheries for decades, and a decline in fecundity was considered a potential evolutionary response to size-selective exploitation. The implications for fishery conservation and management led us to further investigate the fecundity of Yukon River Chinook salmon populations. Matched observations of fecundity, length, and genotype were collected from a sample of adult females captured from the multipopulation spawning migration near the mouth of the Yukon River in 2008. These data were modeled by using a new mixture model, which was developed by extending the conditional maximum likelihood mixture model that is commonly used to estimate the composition of multipopulation mixtures based on genetic data. The new model facilitates maximum likelihood estimation of stock-specific fecundity parameters without first using individual assignment to a putative population of origin, thus avoiding potential biases caused by assignment error.The hypothesis that fecundity of Chinook salmon has declined was not supported; this result implies that fecundity exhibits high interannual variability. However, length-adjusted fecundity estimates decreased as migratory distance increased, and fecundity was more strongly dependent on fish size for populations spawning in the middle and upper portions of the drainage. These findings provide insights into potential constraints on reproductive investment imposed by long migrations and warrant consideration in fisheries management and conservation. The new mixture model extends the utility of genetic markers to new applications and can be easily adapted

  19. Influences of glacial melt and permafrost thaw on the age of dissolved organic carbon in the Yukon River basin

    Science.gov (United States)

    Aiken, George R.; Spencer, Robert G.M.; Striegl, Rob; Schuster, Paul F.; Raymond, Peter A.

    2016-01-01

    Responses of near-surface permafrost and glacial ice to climate change are of particular significance for understanding long-term effects on global carbon cycling and carbon export by high-latitude northern rivers. Here we report Δ14C-dissolved organic carbon (DOC) values and dissolved organic matter optical data for the Yukon River, 15 tributaries of the Yukon River, glacial meltwater, and groundwater and soil water end-member sources draining to the Yukon River, with the goal of assessing mobilization of aged DOC within the watershed. Ancient DOC was associated with glacial meltwater and groundwater sources. In contrast, DOC from watersheds dominated by peat soils and underlain by permafrost was typically enriched in Δ14C indicating that degradation of ancient carbon stores is currently not occurring at large enough scales to quantitatively influence bulk DOC exports from those landscapes. On an annual basis, DOC exported was predominantly modern during the spring period throughout the Yukon River basin and became older through summer-fall and winter periods, suggesting that contributions of older DOC from soils, glacial meltwaters, and groundwater are significant during these months. Our data indicate that rapidly receding glaciers and increasing groundwater inputs will likely result in greater contributions of older DOC in the Yukon River and its tributaries in coming decades.

  20. Juvenile Chinook Salmon abundance in the northern Bering Sea: Implications for future returns and fisheries in the Yukon River

    Science.gov (United States)

    Murphy, James M.; Howard, Kathrine G.; Gann, Jeanette C.; Cieciel, Kristin C.; Templin, William D.; Guthrie, Charles M.

    2017-01-01

    Juvenile Chinook Salmon (Oncorhynchus tshawytscha) abundance in the northern Bering Sea is used to provide insight into future returns and fisheries in the Yukon River. The status of Yukon River Chinook Salmon is of concern due to recent production declines and subsequent closures of commercial, sport, and personal use fisheries, and severe restrictions on subsistence fisheries in the Yukon River. Surface trawl catch data, mixed layer depth adjustments, and genetic stock mixtures are used to estimate juvenile abundance for the Canadian-origin stock group from the Yukon River. Abundance ranged from a low of 0.62 million in 2012 to a high of 2.58 million in 2013 with an overall average of 1.5 million from 2003 to 2015. Although abundance estimates indicate that average survival is relatively low (average of 5.2%), juvenile abundance was significantly correlated (r=0.87, p=0.005) with adult returns, indicating that much of the variability in survival occurs during early life-history stages (freshwater and initial marine). Juvenile abundance in the northern Bering Sea has increased since 2013 due to an increase in early life-history survival (average juveniles-per-spawner increased from 29 to 59). The increase in juvenile abundance is projected to produce larger runs and increased subsistence fishing opportunities for Chinook Salmon in the Yukon River as early as 2016.

  1. Environmental contaminants in fish and their associated risk to piscivorous wildlife in the Yukon River Basin, Alaska

    Science.gov (United States)

    Hinck, J.E.; Schmitt, C.J.; Echols, K.R.; May, T.W.; Orazio, C.E.; Tillitt, D.E.

    2006-01-01

    Organochlorine chemical residues and elemental contaminants were measured in northern pike (Esox lucius), longnose sucker (Catostomus catostomus), and burbot (Lota lota) from 10 sites in the Yukon River Basin (YRB) during 2002. Contaminant concentrations were compared to historical YRB data and to toxicity thresholds for fish and piscivorous wildlife from the scientific literature. A risk analysis was conducted to screen for potential hazards to piscivorous wildlife for contaminants that exceeded literature-based toxicity thresholds. Concentrations of total DDT (sum of p,p???-homologs; 1.09-13.6 ng/g), total chlordane (0.67-7.5 ng/g), dieldrin (growth and reproduction in YRB fish. Concentrations of mercury (0.08-0.65 ??g/g), selenium (0.23-0.85 ??g/g), and zinc (11-56 ??g/g) exceeded toxicity thresholds in one or more samples and were included in the risk analysis for piscivorous wildlife. No effect hazard concentrations (NEHCs) and low effect hazard concentrations (LEHCs), derived from literature-based toxicity reference values and avian and mammalian life history parameters, were calculated for mercury, selenium, and zinc. Mercury concentrations in YRB fish exceeded the NEHCs for all bird and small mammal models, which indicated that mercury concentrations in fish may represent a risk to piscivorous wildlife throughout the YRB. Low risk to piscivorous wildlife was associated with selenium and zinc concentrations in YRB fish. Selenium and zinc concentrations exceeded the NEHCs and LEHCs for only the small bird model. These results indicate that mercury should continue to be monitored and assessed in Alaskan fish and wildlife. ?? 2006 Springer Science+Business Media, Inc.

  2. Strategic needs of water on the Yukon: an interdisciplinary approach to studying hydrology and climate change in the Lower Yukon River Basin

    Science.gov (United States)

    Herman-Mercer, Nicole M.; Schuster, Paul F.

    2014-01-01

    Strategic Needs of Water on the Yukon (SNOWY) is an interdisciplinary research project funded by the National Science Foundation (NSF; http://www.nsf.gov/). The SNOWY team is made up of a diverse group of researchers from different backgrounds and organizations. This partnership between scientists from different disciplines (hydrology, geography, and social science), government agencies, nonprofit organizations, universities, and Lower Yukon River Basin (LYRB) and Yukon-Kuskokwim (YK) Delta communities provided an opportunity to study the effects of climate change using a holistic approach. The Arctic and Subarctic are experiencing environmental change at a rate faster than the rest of the world, and the lack of historical baseline data in these often remote locations makes understanding and predicting regional climate change difficult. This project focused on collecting data to fill in these gaps by using both quantitative and qualitative methodologies to tell the story of environmental change in this region as told by the physical data and the people who rely on this landscape.

  3. Biomonitoring of Environmental Status and Trends (BEST) Program: Environmental contaminants and their effects on fish in the Yukon River Basin

    Science.gov (United States)

    Hinck, Jo Ellen; Bartish, Timothy M.; Blazer, Vicki; Denslow, Nancy D.; Gross, Tim S.; Myers, Mark S.; Anderson, Patrick J.; Orazio, Carl E.; Tillitt, Donald E.

    2004-01-01

    This project collected, examined, and analyzed 217 fish representing three species at 10 stations in the U.S. portion of the Yukon River Basin (YRB) from May to October 2002. Four sampling sites were located on the Yukon River; two were located on the Porcupine River, and one site was on each of the Ray, Tanana, Tolavana, and Innoko Rivers. Norther pike (Esox lucius), longnose sucker (Catostomus catostomus), and burbot (Lota lota) were weighed and measured, and examined in the field for external and internal lesions, and liver, spleen, and gonads were weighed to compute somatic indices. Selected tissues and fluids were collected and preserved for analysis of fish health and reproductive biomarkers. Composite samples of whole fish from each station were grouped by species and gender and analyzed for organochlorines and elemental contaminants and for dioxin-like activity using H4IIE rat hepatoma cell bioassay.

  4. Biodegradability of dissolved organic carbon in the Yukon River and its tributaries: Seasonality and importance of inorganic nitrogen

    Science.gov (United States)

    Wickland, Kimberly P.; Aiken, George R.; Butler, Kenna; Dornblaser, Mark M.; RGM Spencer,; Striegl, Rob

    2012-01-01

    Northern high-latitude rivers transport large amounts of terrestrially derived dissolved organic matter (DOM) from boreal and arctic ecosystems to coastal areas and oceans. Current knowledge of the biodegradability of DOM in these rivers is limited, particularly for large rivers discharging to the Arctic Ocean. We conducted a seasonally comprehensive study of biodegradable dissolved organic carbon (BDOC) dynamics in the Yukon River and two of its tributaries in Alaska, USA. Distinct seasonal patterns of BDOC, consistent across a wide range of watershed size, indicate BDOC is transported year-round. Relative biodegradability (%BDOC) was greatest during winter, and decreased into spring and summer. Due to large seasonal differences in DOC concentration, the greatest concentrations of BDOC (mg C L−1) occurred during spring freshet, followed by winter and summer. While chemical composition of DOM was an important driver of BDOC, the overriding control of BDOC was mineral nutrient availability due to wide shifts in carbon (C) and nitrogen (N) stoichiometry across seasons. We calculated seasonal and annual loads of BDOC exported by the Yukon River by applying measured BDOC concentrations to daily water discharge values, and also by applying an empirical correlation between %BDOC and the ratio of DOC to dissolved inorganic N (DIN) to total DOC loads. The Yukon River exports ∼0.2 Tg C yr−1 as BDOC that is decomposable within 28 days. This corresponds to 12–18% of the total annual DOC export. Furthermore, we calculate that the six largest arctic rivers, including the Yukon River, collectively export ∼2.3 Tg C yr−1 as BDOC to the Arctic Ocean.

  5. Waterfowl populations and production within the impoundment area of the proposed dam at Rampart on the Yukon River, Alaska: Progress report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Investigations to determine the feasibility of a multi-purpose dam in Rampart Canyon of the Yukon River were authorized by Congress in 1959. Construction of the...

  6. Airborne Imaging in the Yukon River Basin to Characterize SWOT Mission Phenomenology

    Science.gov (United States)

    Moller, D.; Pavelsky, T.; Arvesen, J. C.

    2015-12-01

    Remote sensing offers intriguing tools to track Arctic hydrology, but current techniques are largely limited to tracking either inundation or water surface elevation only. For the first time, the proposed Surface Water Ocean Topography (SWOT) satellite mission will provide regular, simultaneous observations of inundation extent and water level from space. SWOT is unique and distinct from precursor altimetry missions in some notable regards: 1) 100km+ of swath will provide complete ocean coverage, 2) in addition to the ocean product, land surface water will be mapped for storage measurement and discharge estimation and 3) Ka-band single-pass interferometry will produce the height measurements introducing a new measurement technique. This new approach introduces additional algorithmic, characterization and calibration/validation needs for which the Ka-band SWOT Phenomenology Airborne Radar (KaSPAR) was developed. In May 2015, AirSWOT (comprised of KaSPAR and a color infrared (CIR) high resolution aerial camera) was part of an intensive field campaign including observations of inundation extent and water level and in situ hydrologic measurements in two rivers and 20 lakes within the Yukon River Basin, Alaska. One goal is to explore the fundamental phenomenology of the SWOT measurement. This includes assessment of the effects of vegetation layover and attenuation, wind roughening and classification. Further KaSPAR-derived inundation extent will to be validated using a combination of ground surveys and coregistered CIR imagery. Ultimately, by combining measurements of changing inundation extent and water level between two collection dates, it will be possible to validate lake water storage variations against storage changes computed from in situ water levels and inundation area derived from AirSWOT. Our paper summarizes the campaign, the airborne and in situ measurements and presents some initial KaSPAR and CIR imagery from the Yukon flats region.

  7. Northern Watershed Change, Modeled Permafrost Temperatures in the Yukon River Watershed

    Science.gov (United States)

    Bryan, R.; Hinzman, L. D.

    2009-12-01

    Changes in the terrestrial hydrologic cycle in northern watersheds can be seen through permafrost warming. Furthermore, vegetation shifts occur with climate changes coupled with permafrost degradation. Permafrost warming is resultant from warming air temperatures and the collection of buffers between the atmosphere and the cryosphere: the active layer, snow, and vegetation. Our modeling methods combine a meteorological model with a permafrost temperature model in 1 km2 resolution in the 847,642 km2 Yukon River Watershed. The MicroMet model is a quasi-physically based model developed in 2006 by Liston & Elder to spatially interpolate irregularly spaced point meteorological data using known temperature-elevation, wind-topography, humidity-cloudiness, and radiation-cloud-topography relationships. We call on 1997-2007 data from 104 Integrated Surface Data meteorological stations and 100 grid points in a 5 best models ensemble A1B 2090-2100 projection. The Temperature at the Top of the Permafrost (TTOP) model is a numerical model for estimating the thermal state of permafrost. This model is attributed to Smith & Riseborough, 1996. TTOP relates more readily available near surface temperatures to temperatures at the depth of seasonal variation using user-defined landcover n-factors (to relate air temperature to soil surface temperature) and soil thermal conductivities (to simulate the propagation of heat through the active layer). TTOP simulates warm top of the permafrost temperatures for high soil thermal conductivity, land cover with high n-factor, and a high number of thawing degree-days/ year. Here we compare the present and future thermal stability of permafrost in the Yukon River Watershed.

  8. Estimating aboveground biomass in the boreal forests of the Yukon River Basin, Alaska

    Science.gov (United States)

    Ji, L.; Wylie, B. K.; Nossov, D.; Peterson, B.; Waldrop, M. P.; McFarland, J.; Alexander, H. D.; Mack, M. C.; Rover, J. A.; Chen, X.

    2011-12-01

    Quantification of aboveground biomass (AGB) in Alaska's boreal forests is essential to accurately evaluate terrestrial carbon stocks and dynamics in northern high-latitude ecosystems. However, regional AGB datasets with spatially detailed information (1 m tall), which were converted to plot-level AGB using allometric equations. We acquired Landsat Enhanced Thematic Mapper Plus (ETM+) images from the Web Enabled Landsat Data (WELD) that provides multi-date composites of top-of-atmosphere reflectance and brightness temperature for Alaska. From the WELD images, we generated a three-year (2008 - 2010) image composite for the Yukon River Basin using a series of compositing criteria including non-saturation, non-cloudiness, maximal normalize difference vegetation index (NDVI), and maximal brightness temperature. Airborne lidar datasets were acquired for two sub-regions in the central basin in 2009, which were converted to vegetation height datasets using the bare-earth digital surface model (DSM) and the first-return DSM. We created a multiple regression model in which the response variable was the field-observed AGB and the predictor variables were Landsat-derived reflectance, brightness temperature, and spectral vegetation indices including NDVI, soil adjusted vegetation index (SAVI), enhanced vegetation index (EVI), normalized difference infrared index (NDII), and normalized difference water index (NDWI). Principal component analysis was incorporated in the regression model to remedy the multicollinearity problems caused by high correlations between predictor variables. The model fitted the observed data well with an R-square of 0.62, mean absolute error of 29.1 Mg/ha, and mean bias error of 3.9 Mg/ha. By applying this model to the Landsat mosaic, we generated a 30-m AGB map for the boreal forests in the Yukon River Basin. Validation of the Landsat-derived AGB using the lidar dataset indicated a significant correlation between the AGB estimates and the lidar

  9. Seasonal Variability in Dissolved Organic Matter Quantity and Composition from the Yukon River Basin

    Science.gov (United States)

    Spencer, R. G.; Aiken, G. R.; Wickland, K. P.; Striegl, R. G.; Hernes, P. J.

    2007-12-01

    The Yukon River basin (YRB) is one of the largest in North America draining an area of 855 x 103 km2 in northwestern Canada and central Alaska and is a major source of terrigenous organic matter to the eastern Bering Sea and Arctic Ocean. The Yukon is also a relatively pristine catchment draining a vast area of taiga that is exceptionally susceptible to climatic change. Dissolved organic matter (DOM) plays a fundamental role in ecosystem biogeochemistry and is ubiquitous in aquatic systems. Samples were collected over a five year period from 2001 to 2005 from a number of locations and at different points in the hydrologic regime throughout the YRB. Sample locations represented different locations on the mainstream of the Yukon River, as well as tributaries ranging from organic rich black waters draining permafrost impacted watersheds to those dominated by glacial melt waters and groundwater. Dissolved organic carbon (DOC) concentrations were observed to vary greatly from 1.5 to 26.1 mgCL-1 depending on source waters and time of year. Specific UV absorbance at 254 nm (SUVA) was also determined and ranged from to 1.3 to 4 highlighting the range in dissolved aromatic carbon content from different sources within the YRB. The hydrophobic acid (HPOA) fraction of the DOM was isolated from samples by XAD-8 resin adsorption for further investigation of DOM composition. The HPOA fraction represented 32 to 57 % of the total DOC for the range of samples studied. SUVA values from the HPOA fraction were higher than the unfractionated water samples (2.5 to 4.4) indicating a higher aromatic content for the HPOA fractions relative to the unfractionated DOM. However, the HPOA SUVA showed a good correlation to the unfractionated water samples SUVA (r2 = 0.84, pgymnosperms and woody and non-woody vascular plant materials, respectively. In addition, acid to aldehyde ratios of vanillyl and syringyl phenols can indicate the degree of oxidation and have been shown to increase with

  10. Spatially explicit estimation of aboveground boreal forest biomass in the Yukon River Basin, Alaska

    Science.gov (United States)

    Ji, Lei; Wylie, Bruce K.; Brown, Dana R. N.; Peterson, Birgit E.; Alexander, Heather D.; Mack, Michelle C.; Rover, Jennifer R.; Waldrop, Mark P.; McFarland, Jack W.; Chen, Xuexia; Pastick, Neal J.

    2015-01-01

    Quantification of aboveground biomass (AGB) in Alaska’s boreal forest is essential to the accurate evaluation of terrestrial carbon stocks and dynamics in northern high-latitude ecosystems. Our goal was to map AGB at 30 m resolution for the boreal forest in the Yukon River Basin of Alaska using Landsat data and ground measurements. We acquired Landsat images to generate a 3-year (2008–2010) composite of top-of-atmosphere reflectance for six bands as well as the brightness temperature (BT). We constructed a multiple regression model using field-observed AGB and Landsat-derived reflectance, BT, and vegetation indices. A basin-wide boreal forest AGB map at 30 m resolution was generated by applying the regression model to the Landsat composite. The fivefold cross-validation with field measurements had a mean absolute error (MAE) of 25.7 Mg ha−1 (relative MAE 47.5%) and a mean bias error (MBE) of 4.3 Mg ha−1(relative MBE 7.9%). The boreal forest AGB product was compared with lidar-based vegetation height data; the comparison indicated that there was a significant correlation between the two data sets.

  11. Indigenous observations of climate change in the Lower Yukon River Basin, Alaska

    Science.gov (United States)

    Herman-Mercer, Nicole M.; Schuster, Paul F.; Maracle, Karonhiakt'tie

    2011-01-01

    Natural science climate change studies have led to an overwhelming amount of evidence that the Arctic and Subarctic are among the world's first locations to begin experiencing climate change. Indigenous knowledge of northern regions is a valuable resource to assess the effects of climate change on the people and the landscape. Most studies, however, have focused on coastal Arctic and Subarctic communities with relatively little focus on inland communities. This paper relates the findings from fieldwork conducted in the Lower Yukon River Basin of Alaska in the spring of 2009. Semi-structured interviews were conducted with hunters and elders in the villages of St. Mary's and Pitka's Point, Alaska to document observations of climate change. This study assumes that scientific findings and indigenous knowledge are complementary and seeks to overcome the false dichotomy that these two ways of knowing are in opposition. The observed changes in the climate communicated by the hunters and elders of St. Mary's and Pitka's Point, Alaska are impacting the community in ways ranging from subsistence (shifting flora and fauna patterns), concerns about safety (unpredictable weather patterns and dangerous ice conditions), and a changing resource base (increased reliance on fossil fuels). Here we attempt to address the challenges of integrating these two ways of knowing while relating indigenous observations as described by elders and hunters of the study area to those described by scientific literature.

  12. Observations and Impacts of Permafrost Thaw in the Lower Yukon River Basin and Yukon Delta Region: the Importance of Local Knowledge

    Science.gov (United States)

    Herman-Mercer, N. M.; Elder, K.; Toohey, R.; Mutter, E. A.

    2015-12-01

    In regions of the arctic and subarctic baseline measurements of permafrost dynamics are lacking and scientific research can be especially expensive when remote sensing techniques are utilized. This research demonstrated the importance of local observations, a powerful tool for understanding landscape change, such as permafrost dynamics. Fifty-five interviews were recently conducted with community members in four villages of the lower Yukon River Basin and Yukon Delta to understand local environmental and landscape changes and the impacts these changes may be having on the lives and livelihoods of these communities. The interviews were semi-structured and focused on many climate and landscape change factors including knowledge of permafrost in their community or the surrounding landscape. All positive respondents stated that they believe the permafrost is thawing. The research revealed that residents of the arctic and subarctic interact with permafrost in a variety of ways. Some people utilize permafrost to store food resources and have found that they have to dig deeper presently than in their youth in order to find ground cold enough. Others are involved in digging graves and report encountering easier excavation in recent years. Subsistence hunters and gatherers travel long distances by snowmobile and boat, and have noticed slumping ground, eroding river banks and coast lines, as well as land that seems to be rising. Finally, all residents of the arctic and subarctic interact with permafrost in terms of the stability of their homes and other infrastructure. Many interview participants complained of their houses leaning and needing more frequent adjustment than in the past. Indigenous residents of the arctic and subarctic have intimate relationships with their landscape owing to their subsistence lifestyle and are also connected to the landscape of the past through the teachings of their elders. Further, arctic and subarctic communities will sustain the majority

  13. Biomarkers of contaminant exposure in northern pike (Esox lucius) from the Yukon River Basin, Alaska

    Science.gov (United States)

    Hinck, J.E.; Blazer, V.S.; Denslow, N.D.; Myers, M.S.; Gross, T.S.; Tillitt, D.E.

    2007-01-01

    As part of a larger investigation, northern pike (n = 158; Esox lucius) were collected from ten sites in the Yukon River Basin (YRB), Alaska, to document biomarkers and their correlations with organochlorine pesticide (total p,p'-DDT, total chlordane, dieldrin, and toxaphene), total polychlorinated biphenyls (PCBs), and elemental contaminant (arsenic, cadmium, copper, lead, total mercury, selenium, and zinc) concentrations. A suite of biomarkers including somatic indices, hepatic 7-ethoxyresorufin O-deethylase (EROD) activity, vitellogenin concentrations, steroid hormone (17B- ustradiol and 16-kebtestosteront) concentrations, splenic macrophage aggregates (MAs), oocyte atresia, and other microscopic anomalies in various tissues were documented in YRB pike. Mean condition factor (0.50 to 0.68), hepatosomatic index (1.00% to 3.56%), and splenosomatic index (0.09% to 0.18%) were not anomalous at any site nor correlated with any contaminant concentration. Mean EROD activity (0.71 to 17.51 pmol/min/mg protein) was similar to basal activity levels previously measured in pike and was positively correlated with selenium concentrations (r = 0.88, P 63 ng/g), and MA-% values in female pike (0.24% to 0.54%) were lower than in male pike (0.32% to 0.75%) at similar PCB concentrations. Greater numbers of MAs were found as zinc concentrations increased in YRB female pike, but it is unlikely that this is a causative relationship. Histological abnormalities observed in gill, liver, spleen, and kidney tissues were not likely a result of contaminant exposure but provide information on the general health of YRB pike. The most common histologic anomalies were parasitic infestations in various organs and developing nephrons and nephrocalcinosis in posterior kidney tissues. Overall, few biomarker responses in YRB pike were correlated with chemical contaminant concentrations, and YRB pike generally appeared to be healthy with no site having multiple anomalous biomarker responses. ?? 2007

  14. Partitioning energy flux using climate record and remote sensing data across the Yukon River Basin, Alaska

    Science.gov (United States)

    Huang, S.; Dahal, D.; Singh, R. K.; Young, C. J.; Tieszen, L. L.; Liu, S.

    2011-12-01

    The Yukon River Basin (YRB) in Alaska is located in high latitudes and underlain by intermittent permafrost, but it is experiencing rapid warming and creating feedback to the climate system. Fire, ecological succession, and climate are interactively affecting YRB ecosystem functions (e.g., primary production, microbial activities, and greenhouse gas emissions) where solar energy transfer processes are critical. Energy flux at some specific locations was investigated; however, variations over landscape level are not well understood. To fully understand the ecosystem dynamics associated with disturbance and climate change, it is important to divide the landscape net radiation (Rn) into three components: latent energy required for evapotranspiration (LE), soil heat flux conducted into the ground (G), and sensible heat flux convected to the air (H). MODerate Resolution Imaging Spectroradiometer (MODIS) products (NDVI, surface temperature, albedo, and emissivity) and hourly weather measurements from 2002-2004 were collected. We developed an energy balance partitioning model that considers the impacts of terrain, vegetation, and climate. A spatial analysis tool was also developed for satellite-based energy balance computation based on the algorithm of "Mapping Evapotranspiration at high Resolution with Internalized Calibration (METRIC)." We computed time series intra- and inter-annual products of LE, G, and H. We have been validating the products using flux tower measurements. Landscape-level products of Rn, LE, G, and H allow us to analyze the spatio-temporal variation of energy flux in the land-atmosphere system. Initial results show that i) landscape heterogeneity in terms of vegetation, elevation, and climate has great effect on the pattern of solar energy partitioning, ii) fire disturbance significantly affects energy flux partitioning. Key words: energy flux, evapotranspiration, flux tower, METRIC, MODIS

  15. Source water controls on the character and origin of dissolved organic matter in streams of the Yukon River basin, Alaska

    Science.gov (United States)

    O'Donnell, Jonathan A.; Aiken, George R.; Kane, Evan S.; Jones, Jeremy B.

    2010-01-01

    Climate warming and permafrost degradation at high latitudes will likely impact watershed hydrology, and consequently, alter the concentration and character of dissolved organic carbon (DOC) in northern rivers. We examined seasonal variation of DOC chemistry in 16 streams of the Yukon River basin, Alaska. Our primary objective was to evaluate the relationship between source water (shallow versus deep groundwater flow paths) and DOC chemical composition. Using base cation chemistry and principal component analysis, we observed high contributions of deep groundwater to glacial and clearwater streams, whereas blackwater streams received larger contributions from shallow groundwater sources. DOC concentration and specific ultraviolet absorbance peaked during spring snowmelt in all streams, and were consistently higher in blackwater streams than in glacial and clearwater streams. The hydrophobic acid fraction of DOC dominated across all streams and seasons, comprising between 35% and 56% of total DOC. The hydrophilic acid fraction of DOC was more prominent in glacial (23% ± 3%) and clearwater streams (19% ± 1%) than in blackwater streams (16% ± 1%), and was enriched during winter base flow (29% ± 1%) relative to snowmelt and summer base flow. We observed that an increase in the contribution of deep groundwater to streamflow resulted in decreased DOC concentration, aromaticity, and DOC-to-dissolved organic nitrogen ratio, and an increase in the proportion of hydrophilic acids relative to hydrophobic acids. Our findings suggest that future permafrost degradation and higher contributions of groundwater to streamflow may result in a higher fraction of labile DOM in streams of the Yukon basin.

  16. Warming in the Yukon River Basin is Likely to Release Substantial Amounts of Soil Organic Carbon

    Science.gov (United States)

    Juday, G. P.; Huntington, T. G.

    2005-12-01

    In recent decades the Yukon River Basin (YRB) in northwestern Canada and central Alaska has experienced a substantial warming trend resulting in a variety of geophysical and biological responses. Climatologic measurements consistent with rapid warming in the YRB during the last several decades of the 20th century include surface air temperature (especially daily minima), number of frost-free days, and the number of very warm days. During the 20th century daily maxima in the warm season in the YRB have increased only weakly, and modest autumn cooling occurred. Indirect indicators of warming include shrinkage in lake area, decreases in glacier mass, increased fire frequency and annual area burned, and changes in permafrost thickness and permafrost temperature. Changes in tree growth rates and susceptibility to pests have been related to warming and drying in interior Alaska. Oral histories of Alaska Natives have also revealed many other warming related changes in the YRB. If ongoing warming trends continue there is a concern that large stores of soil organic carbon (SOC) will be at risk for release to the atmosphere through heterotrophic decomposition. Warming tends to accelerate microbial decomposition at a faster rate than net primary productivity. One of the most important effects of warming in the YRB is likely to be its influence on the hydrologic and cryospheric regimes. Warming may be accompanied by soil drying and lowering of the water table in wetlands and lakes exposing more SOC to aerobic decomposition. A substantial portion of the YRB is underlain by permafrost that thaws to a variable depth (active layer) each summer. Increasing the thickness of the active layer exposes more SOC to microbial decomposition. Increasing the burned area results in direct SOC losses by oxidation during the fire and decreases albedo that warms surface soils and increases the thickness of the active layer. Warming and increasing length of the growing season increases seasonal

  17. Biomarkers of contaminant exposure in Northern Pike (Esox lucius) from the Yukon River Basin, Alaska.

    Science.gov (United States)

    Hinck, J E; Blazer, V S; Denslow, N D; Myers, M S; Gross, T S; Tillitt, D E

    2007-05-01

    As part of a larger investigation, northern pike (n = 158; Esox lucius) were collected from ten sites in the Yukon River Basin (YRB), Alaska, to document biomarkers and their correlations with organochlorine pesticide (total p,p'-DDT, total chlordane, dieldrin, and toxaphene), total polychlorinated biphenyls (PCBs), and elemental contaminant (arsenic, cadmium, copper, lead, total mercury, selenium, and zinc) concentrations. A suite of biomarkers including somatic indices, hepatic 7-ethoxyresorufin O-deethylase (EROD) activity, vitellogenin concentrations, steroid hormone (17B- ustradiol and 16-kebtestosteront) concentrations, splenic macrophage aggregates (MAs), oocyte atresia, and other microscopic anomalies in various tissues were documented in YRB pike. Mean condition factor (0.50 to 0.68), hepatosomatic index (1.00% to 3.56%), and splenosomatic index (0.09% to 0.18%) were not anomalous at any site nor correlated with any contaminant concentration. Mean EROD activity (0.71 to 17.51 pmol/min/mg protein) was similar to basal activity levels previously measured in pike and was positively correlated with selenium concentrations (r = 0.88, P pike were not correlated with any contaminant, but vitellogenin concentrations >0.01 mg/mL in male pike from multiple sites indicated exposure to estrogenic compounds. Mean steroid hormone concentrations and percent oocyte atresia were not anomalous in pike from any YRB site. Few site differences were significant for mean MA density (1.86 to 6.42 MA/mm(2)), size (812 to 1481 microm(2)), and tissue occupied (MA-%; 0.24% to 0.75%). A linear regression between MA-% and total PCBs was significant, although PCB concentrations were generally low in YRB pike (pike (0.24% to 0.54%) were lower than in male pike (0.32% to 0.75%) at similar PCB concentrations. Greater numbers of MAs were found as zinc concentrations increased in YRB female pike, but it is unlikely that this is a causative relationship. Histological abnormalities observed in

  18. Nitrogen cycling processes and microbial community composition in bed sediments in the Yukon River at Pilot Station

    Science.gov (United States)

    Repert, Deborah A.; Underwood, Jennifer C.; Smith, Richard L.; Song, Bongkeun

    2014-01-01

    Information on the contribution of nitrogen (N)-cycling processes in bed sediments to river nutrient fluxes in large northern latitude river systems is limited. This study examined the relationship between N-cycling processes in bed sediments and N speciation and loading in the Yukon River near its mouth at the Bering Sea. We conducted laboratory bioassays to measure N-cycling processes in sediment samples collected over distinct water cycle seasons. In conjunction, the microbial community composition in the bed sediments using genes involved in N-cycling (narG, napA, nosZ, and amoA) and 16S rRNA gene pyrosequences was examined. Temporal variation was observed in net N mineralization, nitrate uptake, and denitrification rate potentials and correlated strongly with sediment carbon (C) and extractable N content and microbial community composition rather than with river water nutrient concentrations. The C content of the bed sediment was notably impacted by the spring flood, ranging from 1.1% in the midst of an ice-jam to 0.1% immediately after ice-out, suggesting a buildup of organic material (OM) prior to scouring of the bed sediments during ice break up. The dominant members of the microbial community that explained differences in N-processing rates belonged to the genera Crenothrix,Flavobacterium, and the family of Comamonadaceae. Our results suggest that biogeochemical processing rates in the bed sediments appear to be more coupled to hydrology, nutrient availability in the sediments, and microbial community composition rather than river nutrient concentrations at Pilot Station.

  19. The Intersection of Environmental Variability, Policy, and Human Values: International Treaties, Yukon River Salmon, and Food Security in a Changing Arctic (Invited)

    Science.gov (United States)

    Gerlach, S.; Loring, P. A.; Murray, M. S.

    2009-12-01

    2009 was a particularly devastating year for rural communities of the Yukon River in Alaska. For a number of reasons, including annual variability in Chinook and Chum salmon runs, imperfect monitoring and information, “best practices” management decisions by regulatory agencies, and international treaty obligations related to conservation and total allowable catch allocation, the smokehouses and freezers of many Alaska Native families, particularly those in up-river communities in the Yukon Flats region, are empty; a problem that has prompted Alaska’s Governor Sean Parnell to ask the US Federal Government to declare a disaster. However, depending on whom you ask, this year’s management of these resources, which provide food security and enable self-reliance in rural communities, may be evaluated as a failure or as a success. How can we reconcile an institutional assessment that claims success as defined in terms of internationally-agreed upon conservation and escapement goals, with the negative economic and health impacts on communities? We use this case to illustrate how the whole Yukon River watershed and drainage, including Alaska and Canada, provides an elegant, geographic context for the discussion and analysis of the human dimensions of environmental change and regional sustainability. Policymakers have arguably gone to great lengths to reconcile competing ‘uses’ of the Yukon River, including commercial and subsistence uses as well as conservation goals, but while managers continue to strive to be ‘adaptive learners’ in their approach to balancing these goals, the impacts on rural communities are immediate and cumulative, synergistic, temporally and spatially scaled, and directly related to rural livelihoods, community health, well-being and sustainability. The cost of this ‘adaptive’ process may be too high, both for the ecosystem and for the people who live there. Are we asking too much of the Yukon River? Are we asking too much of the

  20. Utilizing chromophoric dissolved organic matter measurements to derive export and reactivity of dissolved organic carbon exported to the Arctic Ocean: A case study of the Yukon River, Alaska

    Science.gov (United States)

    Spencer, R.G.M.; Aiken, G.R.; Butler, K.D.; Dornblaser, M.M.; Striegl, R.G.; Hernes, P.J.

    2009-01-01

    The quality and quantity of dissolved organic matter (DOM) exported by Arctic rivers is known to vary with hydrology and this exported material plays a fundamental role in the biogeochemical cycling of carbon at high latitudes. We highlight the potential of optical measurements to examine DOM quality across the hydrograph in Arctic rivers. Furthermore, we establish chromophoric DOM (CDOM) relationships to dissolved organic carbon (DOC) and lignin phenols in the Yukon River and model DOC and lignin loads from CDOM measurements, the former in excellent agreement with long-term DOC monitoring data. Intensive sampling across the historically under-sampled spring flush period highlights the importance of this time for total export of DOC and particularly lignin. Calculated riverine DOC loads to the Arctic Ocean show an increase from previous estimates, especially when new higher discharge data are incorporated. Increased DOC loads indicate decreased residence times for terrigenous DOM in the Arctic Ocean with important implications for the reactivity and export of this material to the Atlantic Ocean. Citation: Spencer, R. G. M., G. R. Aiken, K. D. Butler, M. M. Dornblaser, R. G. Striegl, and P. J. Hernes (2009), Utilizing chromophoric dissolved organic matter measurements to derive export and reactivity of dissolved organic carbon exported to the Arctic Ocean: A case study of the Yukon River, Alaska, Geophys. Res. Lett., 36, L06401, doi:10.1029/ 2008GL036831. Copyright 2009 by the American Geophysical Union.

  1. Uranium isotopes (U-234/U-238) in rivers of the Yukon Basin (Alaska and Canada) as an aid in identifying water sources, with implications for monitoring hydrologic change in arctic regions

    Science.gov (United States)

    Kraemer, Thomas F.; Brabets, Timothy P.

    2012-01-01

    The ability to detect hydrologic variation in large arctic river systems is of major importance in understanding and predicting effects of climate change in high-latitude environments. Monitoring uranium isotopes (234U and 238U) in river water of the Yukon River Basin of Alaska and northwestern Canada (2001–2005) has enhanced the ability to identify water sources to rivers, as well as detect flow changes that have occurred over the 5-year study. Uranium isotopic data for the Yukon River and major tributaries (the Porcupine and Tanana rivers) identify several sources that contribute to river flow, including: deep groundwater, seasonally frozen river-valley alluvium groundwater, and high-elevation glacial melt water. The main-stem Yukon River exhibits patterns of uranium isotopic variation at several locations that reflect input from ice melt and shallow groundwater in the spring, as well as a multi-year pattern of increased variability in timing and relative amount of water supplied from higher elevations within the basin. Results of this study demonstrate both the utility of uranium isotopes in revealing sources of water in large river systems and of incorporating uranium isotope analysis in long-term monitoring of arctic river systems that attempt to assess the effects of climate change.

  2. Assessment of boreal forest historical C dynamics in Yukon River Basin: relative roles of warming and fire regime change

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Fengming [ORNL; Yi, Shuhua [Cold and Arid Regions Environmental and Engineering Research Institute, CAS; McGuire, A. David [University of Alaska; Johnson, Kristopher D [University of Alaska, Fairbanks; Liang, Jingjing [University of Alaska, Fairbanks; Harden, Jennifer [USGS, Menlo Park, CA; Kasischke, Eric S. [University of Maryland, College Park; Kurz, Werner [Canadian Forest Service

    2012-01-01

    Carbon (C) dynamics of boreal forest ecosystems have substantial implications for efforts to mitigate the rise of atmospheric CO2 and may be substantially influenced by warming and changing wildfire regimes. In this study we applied a large-scale ecosystem model that included dynamics of organic soil horizons and soil organic matter characteristics of multiple pools to assess forest C stock changes of the Yukon River Basin (YRB) in Alaska, USA, and Canada from 1960 through 2006, a period characterized by substantial climate warming and increases in wildfire. The model was calibrated for major forests with data from long-term research sites and evaluated using a forest inventory database. The regional assessment indicates that forest vegetation C storage increased by 46 Tg C, but that total soil C storage did not change appreciably during this period. However, further analysis suggests that C has been continuously lost from the mineral soil horizon since warming began in the 1970s, but has increased in the amorphous organic soil horizon. Based on a factorial experiment, soil C stocks would have increased by 158 Tg C if the YRB had not undergone warming and changes in fire regime. The analysis also identified that warming and changes in fire regime were approximately equivalent in their effects on soil C storage, and interactions between these two suggests that the loss of organic horizon thickness associated with increases in wildfire made deeper soil C stocks more vulnerable to loss via decomposition. Subbasin analyses indicate that C stock changes were primarily sensitive to the fraction of burned forest area within each subbasin and that boreal forest ecosystems in the YRB are currently transitioning from being sinks to sources at ;0.7% annual area burned. We conclude that it is important for international mitigation efforts focused on controlling atmospheric CO2 to consider how climate warming and changes in fire regime may concurrently affect the CO2 sink

  3. Novel insights from NMR spectroscopy into seasonal changes in the composition of dissolved organic matter exported to the Bering Sea by the Yukon River

    Science.gov (United States)

    Cao, Xiaoyan; Aiken, George R.; Spencer, Robert G. M.; Butler, Kenna D.; Mao, Jingdong; Schmidt-Rohr, Klaus

    2016-01-01

    Seasonal (spring freshet, summer–autumn, and winter) variability in the chemical composition of dissolved organic matter (DOM) from the Yukon River was determined using advanced one- and two-dimensional (2D) solid-state NMR spectroscopy, coupled with isotopic measurements and UV–visible spectroscopy. Analyses were performed on two major DOM fractions, the hydrophobic organic acid (HPOA) and transphilic organic acid (TPIA) fractions obtained using XAD resins. Together these two fractions comprised 64–74% of the total DOM. Carboxyl-rich alicyclic molecules (CRAM) accounted for the majority of carbon atoms in the HPOA (63–77%) and TPIA (54–78%) samples, and more so in winter and summer than in spring samples. 2D and selective NMR data revealed association of abundant nonprotonated O-alkyl and quaternary alkyl C (OCnp, OCnpO and Cq, 13–17% of HPOA and 15–20% of TPIA) and isolated O–CH structures with CRAM, which were not recognized in previous studies. Spectral editing and 2D NMR allowed for the discrimination of carbohydrate-like O-alkyl C from non-carbohydrate O-alkyl C. Whereas two spring freshet TPIA samples contained carbohydrate clusters such as carboxylated carbohydrates (16% and 26%), TPIA samples from other seasons or HPOA samples mostly had small amounts (<8%) of sugar rings dispersed in a nonpolar alkyl environment. Though nonprotonated aromatic C represented the largest fraction of aromatic C in all HPOA/TPIA isolates, only a small fraction (∼5% in HPOA and 3% in TPIA) was possibly associated with dissolved black carbon. Our results imply a relatively stable portion of DOM exported by the Yukon River across different seasons, due to the predominance of CRAM and their associated nonprotonated C–O and O–C–O structures, and elevated reactivity (bio- and photo-lability) of spring DOM due to the presence of terrestrial inputs enriched in carbohydrates and aromatic structures.

  4. Educational Psychology in Yukon

    Science.gov (United States)

    Bradford, Charlene T.; Kroeker, Sharon D. L.

    2016-01-01

    Directly employed by the territorial government, Yukon's educational psychologists are moving away from "refer-test-place" services by actively clarifying a broader scope of practice within a non-categorical model of special education services. Yukon's educational psychologists provide a variety of services, such as consultation,…

  5. Novel insights from NMR spectroscopy into seasonal changes in the composition of dissolved organic matter exported to the Bering Sea by the Yukon River

    Science.gov (United States)

    Cao, Xiaoyan; Aiken, George R.; Spencer, Robert G. M.; Butler, Kenna; Mao, Jingdong; Schmidt-Rohr, Klaus

    2016-05-01

    Seasonal (spring freshet, summer-autumn, and winter) variability in the chemical composition of dissolved organic matter (DOM) from the Yukon River was determined using advanced one- and two-dimensional (2D) solid-state NMR spectroscopy, coupled with isotopic measurements and UV-visible spectroscopy. Analyses were performed on two major DOM fractions, the hydrophobic organic acid (HPOA) and transphilic organic acid (TPIA) fractions obtained using XAD resins. Together these two fractions comprised 64-74% of the total DOM. Carboxyl-rich alicyclic molecules (CRAM) accounted for the majority of carbon atoms in the HPOA (63-77%) and TPIA (54-78%) samples, and more so in winter and summer than in spring samples. 2D and selective NMR data revealed association of abundant nonprotonated O-alkyl and quaternary alkyl C (OCnp, OCnpO and Cq, 13-17% of HPOA and 15-20% of TPIA) and isolated O-CH structures with CRAM, which were not recognized in previous studies. Spectral editing and 2D NMR allowed for the discrimination of carbohydrate-like O-alkyl C from non-carbohydrate O-alkyl C. Whereas two spring freshet TPIA samples contained carbohydrate clusters such as carboxylated carbohydrates (16% and 26%), TPIA samples from other seasons or HPOA samples mostly had small amounts (structures, and elevated reactivity (bio- and photo-lability) of spring DOM due to the presence of terrestrial inputs enriched in carbohydrates and aromatic structures.

  6. Reconstructing satellite images to quantify spatially explicit land surface change caused by fires and succession: A demonstration in the Yukon River Basin of interior Alaska

    Science.gov (United States)

    Huang, Shengli; Jin, Suming; Dahal, Devendra; Chen, Xuexia; Young, Claudia; Liu, Heping; Liu, Shuguang

    2013-05-01

    Land surface change caused by fires and succession is confounded by many site-specific factors and requires further study. The objective of this study was to reveal the spatially explicit land surface change by minimizing the confounding factors of weather variability, seasonal offset, topography, land cover, and drainage. In a pilot study of the Yukon River Basin of interior Alaska, we retrieved Normalized Difference Vegetation Index (NDVI), albedo, and land surface temperature (LST) from a postfire Landsat image acquired on August 5th, 2004. With a Landsat reference image acquired on June 26th, 1986, we reconstructed NDVI, albedo, and LST of 1987-2004 fire scars for August 5th, 2004, assuming that these fires had not occurred. The difference between actual postfire and assuming-no-fire scenarios depicted the fires and succession impact. Our results demonstrated the following: (1) NDVI showed an immediate decrease after burning but gradually recovered to prefire levels in the following years, in which burn severity might play an important role during this process; (2) Albedo showed an immediate decrease after burning but then recovered and became higher than prefire levels; and (3) Most fires caused surface warming, but cooler surfaces did exist; time-since-fire affected the prefire and postfire LST difference but no absolute trend could be found. Our approach provided spatially explicit land surface change rather than average condition, enabling a better understanding of fires and succession impact on ecological consequences at the pixel level.

  7. Aerial videography of brant colonies on Yukon Delta NWR in 1995

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Aerial surveys at five black brant colonies on the Yukon-Kuskokwim Delta--KokechikBay (KB), Tutakoke River (TR), Kigigak Island (KI), Baird Inlet Island (BI), and a...

  8. Aerial videography of brant colonies on Yukon Delta NWR in 2001

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Aerial surveys at five black brant colonies on the Yukon-Kuskokwim Delta--Kokechik Bay (KB), Tutakoke River (TR), Kigigak Island (KI), Baird Inlet Island (BI), and a...

  9. Communicating Risk and Cultivating Resilience in Rural Alaskan Communities: A Multi-Disciplinary Approach to Flood Mitigation

    Science.gov (United States)

    Kontar, Y. Y.

    2014-12-01

    The increasing extent and vulnerability of technologically advanced society together with aspects of global climate change intensifies the frequency and severity of natural disasters. Every year, communities around the world face the devastating consequences of hazardous events, including loss of life, property and infrastructure damage, and environmental decline. Environmentally sound strategies have to be developed to minimize these consequences. However, hazard-prone areas differ geographically, climatically, and culturally. There is no a one-size-fits-all solution. Thus, it is crucial that future decision-makers not only know the conditions that make some natural Earth processes hazardous to people, but also understand how people perceive and adjust to potential natural hazards in their regions. In May 2013, an ice jam caused major flooding in Galena, a remote village in interior Alaska. Within two days, flooding destroyed nearly the entire region's infrastructure, and displaced over 400 residents. Almost a year later, a significant part of Galena's population was still evacuated in Fairbanks and other neighboring towns. The rebuilding holdup reflected the federal government's reluctance to spend millions of dollars an the area that may be destroyed again by the next flood. Massive floods inundated towns along the Yukon River before (e.g., Eagle in 2009 and Holycross in 1975), but people return to refurbish and again inhabit the same territories. Rivers have a significant importance to Alaskan rural communities. Not only do rivers provide food, drink, transportation, and in some cases arable land and irrigation, but they also carry cultural significance for the Native Alaskan people. The Galena case study provides a revealing example of challenges of communicating with and educating the public and policy makers about natural hazards.

  10. Wandering gravel-bed rivers and high-constructive stable channel sandy fluvial systems in the Ross River area, Yukon Territory, Canada

    Directory of Open Access Journals (Sweden)

    Darrel G.F. Long

    2011-07-01

    Gravel-dominated strata, inter-bedded with, and overlying coal-bearing units, are interpreted as deposits of wandering gravel-bed rivers, with sinuosity approaching 1.4. In most exposures they appear to be dominated by massive and thin planar-bedded granule to small pebble conglomerates, which would traditionally be interpreted as sheet-flood or longitudinal bar deposits of a high-gradient braided stream or alluvial fan. Architectural analysis of exposures in an open-pit shows that the predominance of flat bedding is an artefact of the geometry of the roadside exposures. In the pit the conglomerates are dominated by large scale cross stratification on a scale of 1–5.5 m. These appear to have developed as downstream and lateral accretion elements on side-bars and on in-channel bars in water depths of 2–12 m. Stacking of strata on domed 3rd order surfaces suggests development of longitudinal in-channel bar complexes similar to those observed in parts of the modern Rhône River system. Mudstone preserved in some of the channels reflects intervals of channel abandonment or avulsion. Minimum channel width is from 70 to 450 m.

  11. Relationships between ecosystem metabolism, benthic macroinvertebrate densities, and environmental variables in a sub-arctic Alaskan river

    Science.gov (United States)

    Benson, Emily R.; Wipfli, Mark S.; Clapcott, Joanne E.; Hughes, Nicholas F.

    2013-01-01

    Relationships between environmental variables, ecosystem metabolism, and benthos are not well understood in sub-arctic ecosystems. The goal of this study was to investigate environmental drivers of river ecosystem metabolism and macroinvertebrate density in a sub-arctic river. We estimated primary production and respiration rates, sampled benthic macroinvertebrates, and monitored light intensity, discharge rate, and nutrient concentrations in the Chena River, interior Alaska, over two summers. We employed Random Forests models to identify predictor variables for metabolism rates and benthic macroinvertebrate density and biomass, and calculated Spearman correlations between in-stream nutrient levels and metabolism rates. Models indicated that discharge and length of time between high water events were the most important factors measured for predicting metabolism rates. Discharge was the most important variable for predicting benthic macroinvertebrate density and biomass. Primary production rate peaked at intermediate discharge, respiration rate was lowest at the greatest time since last high water event, and benthic macroinvertebrate density was lowest at high discharge rates. The ratio of dissolved inorganic nitrogen to soluble reactive phosphorus ranged from 27:1 to 172:1. We found that discharge plays a key role in regulating stream ecosystem metabolism, but that low phosphorous levels also likely limit primary production in this sub-arctic stream.

  12. History of Yukon first nations art

    NARCIS (Netherlands)

    Kampen, Ukjese van

    2012-01-01

    The thesis argues that contrary to the present opinion in the Yukon that there was little or no early Yukon First Nations art, there was in fact an established First Nations artistic tradition in the Yukon before the coming of the white man and also into the early contact years. It is also the gener

  13. Fort Yukon, Chalkyitsik, & Venetie Biomass Boiler Feasibility Study

    Energy Technology Data Exchange (ETDEWEB)

    Greg Koontz, ME William A. Wall, PhD

    2009-03-31

    The Council of Athabascan Tribal Governments (CATG) is a consortium of ten Gwich'in and Koyukon Athabascan tribes settled in 10 remote villages and are linked by the Yukon River System. The CATG mission is to maintain the Yukon Flats region as Indian Country by asserting traditional rights and taking responsibility for developing tribal technical capacity to manage the land and resources. It is the intent of CATG to explore and develop all opportunities for a renewable and self-sufficient energy program for each of the villages. CATG envisions utilization of forest resources both for construction and energy as one of the best long-term strategies for integrating the economic goals for the region as well as supporting the cultural and social issues. The intent for this feasibility project is to focus specifically on biomass utilization for heat, first, and for future electrical generation within the region, second. An initial determination has already been made regarding the importance of wood energy as a primary source of renewable energy to displace diesel fuel in the Yukon Flats region. A desktop study of other potential renewable resources was conducted in 2006.

  14. Ice break-up and snow-melt as spring indices of reproductive effort and population size of Pacific brant at the Kashunuk River, Yukon-Kuskokwim Delta, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Yukon-Kuskokwim Delta (YKD) is the most southerly (60° to 62°N) and the only sub-Arctic breeding area of Pacific brant (Branta bemicla nigricans) supporting an...

  15. An Alaskan legend

    Science.gov (United States)

    Mann, H.; Blodgett, R.B.

    2009-01-01

    Jack Lee is a prominent personality, an Alaskan individualist and a skeptic worthy of remembrance if for no other reason than being inextricably associated with the catastrophic Katmai eruption in 1912. Jack remains a provocative reminder of Alaska's pre-1958 drilling and was quite possibly the earliest observer (excepting natives and possibly Russians) of the oil seeps in the area now encompassed by the Becharof National Wildlife Refuge. His observation of the impressive live oil seeps in the Ugashik and Becharof Lakes area, and his subsequent involvement in the early drilling entirely consumed his future interests. He is a firm believer that individualism and suspicion are powerful tools when forced to reconsider alternatives to readily accepted interpretations of modern exploration results. His individualism and sometimes annoying, but thought-provoking skepticism remains useful in any field where clich??s provide safe guards from new concepts.

  16. Alaska Yukon : Waterfowl Breeding Population Survey

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Alaska-Yukon was again blessed with a generally widespread, early spring break-up in the interior and on the North Slope with perhaps a more normal spring phenology...

  17. Cackling Canada goose nesting populations, Yukon Delta

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Number of potential territories, number of cackling Canada Goose nests, and percent occupancy of available territories from CCG plots on the Yukon Delta National...

  18. Alaskan North Slope petroleum systems

    Science.gov (United States)

    Magoon, L.B.; Lillis, P.G.; Bird, K.J.; Lampe, C.; Peters, K.E.

    2003-01-01

    Six North Slope petroleum systems are identified, described, and mapped using oil-to-oil and oil-to-source rock correlations, pods of active source rock, and overburden rock packages. To map these systems, we assumed that: a) petroleum source rocks contain 3.2 wt. % organic carbon (TOC); b) immature oil-prone source rocks have hydrogen indices (HI) >300 (mg HC/gm TOC); c) the top and bottom of the petroleum (oil plus gas) window occur at vitrinite reflectance values of 0.6 and 1.0% Ro, respectively; and d) most hydrocarbons are expelled within the petroleum window. The six petroleum systems we have identified and mapped are: a) a southern system involving the Kuna-Lisburne source rock unit that was active during the Late Jurassic and Early Cretaceous; b) two western systems involving source rock in the Kingak-Blankenship, and GRZ-lower Torok source rock units that were active during the Albian; and c) three eastern systems involving the Shublik-Otuk, Hue Shale and Canning source rock units that were active during the Cenozoic. The GRZ-lower Torok in the west is correlative with the Hue Shale to the east. Four overburden rock packages controlled the time of expulsion and gross geometry of migration paths: a) a southern package of Early Cretaceous and older rocks structurally-thickened by early Brooks Range thrusting; b) a western package of Early Cretaceous rocks that filled the western part of the foreland basin; c) an eastern package of Late Cretaceous and Paleogene rocks that filled the eastern part of the foreland basin; and d) an offshore deltaic package of Neogene rocks deposited by the Colville, Canning, and Mackenzie rivers. This petroleum system poster is part of a series of Northern Alaska posters on modeling. The poster in this session by Saltus and Bird present gridded maps for the greater Northern Alaskan onshore and offshore that are used in the 3D modeling poster by Lampe and others. Posters on source rock units are by Keller and Bird as well as

  19. Martian and Ionian Analogs of Permafrost-Volcano Interactions in Alaskan Permafrost

    Science.gov (United States)

    Kargel, J. S.; Beget, J. E.; Skinner, J. A.; Wessels, R.

    2005-12-01

    Volcanic landforms in Alaskan lowland permafrost exhibit several unique morphological attributes, as described in a companion AGU abstract (Beget et al.). These features include (1) giant maar sizes (in Bering Land Bridge National Preserve) an order of magnitude larger than common in non-permafrost terrains, (2) composite volcanic forms produced by repeated maar-forming explosions (the novel Ingakslugwat-type volcano in Yukon Delta), and (3) super-inflated lava flows with marginal thermokarst pits (Lost Jim flow, Imuruk Lake Volcanic Field, Bering Land Bridge area). We have identified on Mars, in areas not indicating glaciation, several landforms and on Io an active volcanic process that might be analogs of these in Alaska. On Mars, within and near Elysium (Galaxias Fossae and Hrad Vallis region) multiple crater-like depressions occur with other volcanic features. Their characteristics suggest that the depressions are maars. The composite structures suggest similarities to Ingakslugwat volcanoes. Possible analogs of giant oversize maars also have been identified on Mars. In addition to surface gravitational differences between Earth and Mars, it seems likely that volatile composition is a key aspect controlling the explosivity and sizes of maars on both planets. In Alaska, we suspect that volcanic interactions with methane clathrate hydrate-rich permafrost tends to yield larger maar sizes than with ice-rich permafrost or ground water. This working hypothesis fits well with observations that the giant maars formed during the climatically coldest periods (Beget et al., 2005, this conference). During those periods, permafrost was thick, strong, and unpunctured by lakes and rivers, and so it could have trapped clathrate-forming gases. During interglacials, thinner permafrost and the widespread occurrence of thaw lakes and surface streams may cause the permafrost to be ineffective in confining ascending gases, and so clathrates were absent or not abundant, and volcanic

  20. Value of Alaskan wetlands for waterfowl: Draft

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Few studies have focused specifically on use of Alaskan wetlands by waterfowl and only two of these have been published. However, substantial information on the...

  1. Permafrost response to last interglacial warming: field evidence from non-glaciated Yukon and Alaska

    Science.gov (United States)

    Reyes, Alberto V.; Froese, Duane G.; Jensen, Britta J. L.

    2010-11-01

    We present stratigraphic observations from three sites in eastern Beringia - Ch'ijee's Bluff in northern Yukon and nearby exposures on the Old Crow River, the Palisades on the Yukon River in Alaska, and placer mining exposures at Thistle Creek in west-central Yukon - which provide insight into the response of permafrost to regional warming during the last interglaciation. Chronology is based on the presence of Old Crow tephra, an important regional stratigraphic marker that dates to late Marine Isotope Stage 6, supplemented by paleoecology and non-finite 14C ages on wood-rich organic silts. Old Crow tephra overlies several relict ice wedges at the Palisades and Thistle Creek, indicating that permafrost at these sites did not thaw completely during the last interglaciation. Prominent deposits of last interglacial wood-rich organic silt are present at multiple sites in eastern Beringia, and probably represent accumulations of reworked forest vegetation due to thaw slumping or deposition into thermokarst ponds or depressions. Consistent stratigraphic relations between these deposits, Old Crow tephra, and ice wedge pseudomorphs at our three study sites, and at least six other sites in eastern Beringia, suggest that thaw of shallow permafrost was widespread during the last interglaciation. Limited stratigraphic evidence suggests that thaw was probably on the order of meters, rather than 10s of meters. The ubiquity of shallow permafrost degradation during the last interglaciation suggests that current ground warming may foreshadow widespread near-surface thaw under even modest future warming scenarios. However, the persistence of relict pre-last interglacial ice wedges highlights the potential for the regional antiquity of discontinuous permafrost, and provides compelling field evidence for the long-term resilience of deep permafrost during sustained periods of warmer-than-present climate.

  2. Yukon Delta National Wildlife Refuge : Narrative Report : Calendar Year 1986

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Delta National Wildlife Refuge outlines Refuge accomplishments during the 1986 calendar year. The report begins with a summary...

  3. Yukon Delta National Wildlife Refuge : Narrative Report : Calendar Year 1987

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Delta National Wildlife Refuge outlines Refuge accomplishments during the 1987 calendar year. The report begins with a summary...

  4. Yukon Delta National Wildlife Refuge : Narrative Report : Calendar Year 1989

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Delta National Wildlife Refuge outlines Refuge accomplishments during the 1989 calendar year. The report begins with a summary...

  5. Yukon Delta National Wildlife Refuge : Narrative Report : Calendar Year 2002

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Delta National Wildlife Refuge outlines Refuge accomplishments during the 2002 calendar year. The report begins with a summary...

  6. Yukon Delta National Wildlife Refuge : Narrative Report : Calendar Year 2001

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Delta National Wildlife Refuge outlines Refuge accomplishments during the 2001 calendar year. The report begins with a summary...

  7. Yukon Delta National Wildlife Refuge : Narrative Report : Calendar Year 1997

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Delta National Wildlife Refuge outlines Refuge accomplishments during the 1997 calendar year. The report begins with a summary...

  8. Yukon Delta National Wildlife Refuge : Narrative Report : Calendar Year 1982

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Delta, Nunivak National Wildlife Refuge outlines Refuge accomplishments during the 1982 calendar year. The report begins with...

  9. Yukon Flats National Wildlife Refuge : Narrative Report : Calendar Year 1991

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Flats National Wildlife Refuge outlines Refuge accomplishments during the 1991 calendar year. The report begins with a summary...

  10. Yukon Flats National Wildlife Refuge : Narrative Report : Calendar Year 1998

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Flats National Wildlife Refuge outlines Refuge accomplishments during the 1998 calendar year. The report begins with a summary...

  11. Yukon Flats National Wildlife Refuge : Narrative Report : Calendar Year 1992

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Flats National Wildlife Refuge outlines Refuge accomplishments during the 1992 calendar year. The report begins with a summary...

  12. Yukon Flats National Wildlife Refuge : Narrative Report : Calendar Year 1990

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Flats National Wildlife Refuge outlines Refuge accomplishments during the 1990 calendar year. The report begins with a summary...

  13. Yukon Flats National Wildlife Refuge : Narrative Report : Calendar Year 1997

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Flats National Wildlife Refuge outlines Refuge accomplishments during the 1997 calendar year. The report begins with a summary...

  14. Yukon Flats National Wildlife Refuge : Narrative Report : Calendar Year 1993

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Flats National Wildlife Refuge outlines Refuge accomplishments during the 1993 calendar year. The report begins with a summary...

  15. Yukon Flats National Wildlife Refuge : Narrative Report : Calendar Year 1996

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Flats National Wildlife Refuge outlines Refuge accomplishments during the 1996 calendar year. The report begins with a summary...

  16. Yukon Flats National Wildlife Refuge : Narrative Report : Calendar Year 2001

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Flats National Wildlife Refuge outlines Refuge accomplishments during the 2001 calendar year. The report begins with a summary...

  17. Yukon Flats National Wildlife Refuge : Narrative Report : Calendar Year 2000

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Flats National Wildlife Refuge outlines Refuge accomplishments during the 2000 calendar year. The report begins with a summary...

  18. Yukon Flats National Wildlife Refuge : Narrative Report : Calendar Year 1994

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Flats National Wildlife Refuge outlines Refuge accomplishments during the 1994 calendar year. The report begins with a summary...

  19. Yukon Delta National Wildlife Refuge : Narrative Report : Calendar Year 1999

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Delta National Wildlife Refuge outlines Refuge accomplishments during the 1999 calendar year. The report begins with a summary...

  20. Yukon Delta National Wildlife Refuge : Narrative Report : Calendar Year 1983

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Delta National Wildlife Refuge outlines Refuge accomplishments during the 1983 calendar year. The report begins with a summary...

  1. Yukon Delta National Wildlife Refuge : Narrative Report : Calendar Year 1992

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Delta National Wildlife Refuge outlines Refuge accomplishments during the 1992 calendar year. The report begins with a summary...

  2. Yukon Flats National Wildlife Refuge Fishery. Management Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Yukon Flats National Wildlife Refuge Fishery Management Plan (Fishery Plan) provides comprehensive management direction to insure that fish species and habitats...

  3. Yukon Flats National Wildlife Refuge : Narrative Report : Calendar Year 1983

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Flats National Wildlife Refuge outlines Refuge accomplishments during the 1983 calendar year. The report begins with a summary...

  4. Yukon Flats National Wildlife Refuge : Narrative Report : Calendar Year 1989

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Flats National Wildlife Refuge outlines Refuge accomplishments during the 1989 calendar year. The report begins with a summary...

  5. Yukon Flats National Wildlife Refuge : Narrative Report : Calendar Year 1987

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Flats National Wildlife Refuge outlines Refuge accomplishments during the 1987 calendar year. The report begins with a summary...

  6. Yukon Flats National Wildlife Refuge : Narrative Report : Calendar Year 1984

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Flats National Wildlife Refuge outlines Refuge accomplishments during the 1984 calendar year. The report begins with a summary...

  7. Yukon Flats National Wildlife Refuge : Narrative Report : Calendar Year 1988

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Flats National Wildlife Refuge outlines Refuge accomplishments during the 1988 calendar year. The report begins with a summary...

  8. Yukon Flats National Wildlife Refuge : Narrative Report : Calendar Year 1985

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Flats National Wildlife Refuge outlines Refuge accomplishments during the 1985 calendar year. The report begins with a summary...

  9. Yukon Flats National Wildlife Refuge : Narrative Report : Calendar Year 1986

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Flats National Wildlife Refuge outlines Refuge accomplishments during the 1986 calendar year. The report begins with a summary...

  10. Yukon Delta National Wildlife Refuge : Narrative Report : Calendar Year 1995

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Delta National Wildlife Refuge outlines Refuge accomplishments during the 1995 calendar year. The report begins with a summary...

  11. Yukon Flats National Wildlife Refuge : Narrative Report : Calendar Year 1981

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Flats National Wildlife Refuge outlines Refuge accomplishments during the 1981 calendar year. The report begins with a...

  12. Yukon Flats National Wildlife Refuge : Narrative Report : Calendar Year 1982

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Flats National Wildlife Refuge outlines Refuge accomplishments during the 1982 calendar year. The report begins with a...

  13. Yukon Delta National Wildlife Refuge : Narrative Report : Calendar Year 1996

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Delta National Wildlife Refuge outlines Refuge accomplishments during the 1996 calendar year. The report begins with a summary...

  14. Migratory Bird Avian Influenza Sampling; Yukon Kuskokwim Delta, Alaska, 2015

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Data set containing avian influenza sampling information for spring and summer waterbirds on the Yukon Kuskokwim Delta, 2015. Data contains sample ID, species common...

  15. Yukon Delta National Wildlife Refuge : Narrative Report : Calendar Year 2000

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Delta National Wildlife Refuge outlines Refuge accomplishments during the 2000 calendar year. The report begins with a summary...

  16. The status of peregrine falcons and other raptors along the Porcupine River, Alaska, 1981: Final report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In 1979, the U.S. Fish and Wildlife Service initiated a banding project on the Yukon, Porcupine, and Colville rivers where high concentrations of peregrines are...

  17. Spectacled eider (Somateria fischeri) nest records Kashunuk River and Kigigak Island, Alaska, 1991-2004

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Data set containing nest records for Spectacled Eiders near the Kashunuk River and on Kigigak Island, within the Yukon-Kuskokwim Delta, Alaska. Nests were visited...

  18. The status of Rangifer tarandus caribou in Yukon, Canada

    Directory of Open Access Journals (Sweden)

    R. Farnell

    1998-03-01

    Full Text Available This paper summarizes the population trends as well as research and management programs for woodland caribou {Rangifer tarandus caribou in Yukon. Most herds are stable although not all are counted regularly and systematic monitoring of herds remains an essential need. Over the past decade the Southern Lakes, Aishihik, and Finlayson herds have been well studied and provide valuable models for guiding Yukon management programs. Over harvest and the spread of agriculture, forestry and mining are ongoing human activities are of concern to caribou managers.

  19. Cliff nesting raptors of the Kisaralik River, western Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — For three consecutive years (1977 - 79), about 79 km (49 mi) of Alaskan river canyons were surveyed for raptors by helicopter. Occupation of eight breeding...

  20. Offshore oil in the alaskan arctic.

    Science.gov (United States)

    Weeks, W F; Weller, G

    1984-07-27

    Oil and gas deposits in the Alaskan Arctic are estimated to contain up to 40 percent of the remaining undiscovered crude oil and oil-equivalent nature gas within U.S. jurisdiction. Most (65 to 70 percent) of these estimated reserves are believed to occur offshore beneath the shallow, ice-covered seas, of the Alaskan continental shelf. Offshore recovery operations for such areas are far from routine, with the primary problems associated with the presence of ice. Some problems that must be resolved if efficient, cost-effective, environmentally safe, year-round offshore production is to be achieved include the accurate estimation of ice forces on offshore structures, the proper placement of pipelines beneath ice-produced gouges in the sea floor, and the cleanup of oil spills in pack ice areas.

  1. Degradation and Local Survival of Permafrost Through the Last Interglaciation in Interior Alaska and Yukon Territory

    Science.gov (United States)

    Reyes, A. V.; Froese, D. G.; Jensen, B. J.

    2006-12-01

    Permafrost in northern North America is warming, and recent modeling efforts have predicted the widespread disappearance of permafrost through much of the northern hemisphere over the next century. However, little is known of the impacts of past sustained warm intervals on permafrost dynamics, antiquity, and distribution due to difficulties in establishing reliable chronologies. Permafrost thus remains the last element of the Arctic cryosphere for which there is poor understanding of its adaptability to past warmer-than-present climate. Here we present observations from three sites in the region of interior Alaska and Yukon Territory that remained ice-free during Plio-Pleistocene glaciations, which collectively demonstrate the variable nature of the response of permafrost to warming during the last interglaciation. Chronology for all sites is based on identification of Old Crow tephra (OCt; 140±10 ka) by glass major element composition. Throughout the study region, OCt is consistently associated with organic-rich sediments that represent the last interglaciation on the basis of pollen, insect, and macrofossil assemblages. At the Palisades site on the Yukon River, 250 km west of Fairbanks, OCt is 1.5-3.5 m below thick (>1m) organic-rich silts and peats that are locally rich in beaver-chewed wood and large wood stumps, some of which are in growth position. In contrast, placer mining at Thistle Creek in central Yukon Territory exposes a dramatic thaw unconformity that is presumably related to local, but incomplete, permafrost degradation during the last interglaciation. In upslope positions at Thistle Creek, OCt is incorporated into a steeply dipping, 30 cm thick, organic-rich silt horizon that truncates at least one intact, relict ice wedge. The steeply dipping organic- rich horizon grades downslope into organic-rich silt with dense accumulations of wood fragments, including tree stems up to 2 m long. Evidence for similar permafrost degradation during the last

  2. Alaskan Haida Stories of Language Growth and Regeneration

    Science.gov (United States)

    Breinig, Jeane

    2006-01-01

    In this article, the author talks about the decline of fluent Alaskan Haida speakers. She features her mother's story as an example of why the Haida language is "on the brink." English language fluency as a tool for Indigenous survival is common to Native peoples, as is the desire to see languages flourish again. Alaskan Haidas…

  3. Inconsistency in precipitation measurements across Alaska and Yukon border

    Directory of Open Access Journals (Sweden)

    L. Scaff

    2015-07-01

    Full Text Available This study quantifies the inconsistency in gauge precipitation observations across the border of Alaska and Yukon. It analyses the precipitation measurements by the national standard gauges (NWS 8-in gauge and Nipher gauge, and the bias-corrected data to account for wind effect on the gauge catch, wetting loss and trace events. The bias corrections show a significant amount of errors in the gauge records due to the windy and cold environment in the northern areas of Alaska and Yukon. Monthly corrections increase solid precipitation by 135 % in January, 20 % for July at the Barter Island in Alaska, and about 31 % for January and 4 % for July at the Yukon stations. Regression analyses of the monthly precipitation data show a stronger correlation for the warm months (mainly rainfall than for cold month (mainly snowfall between the station pairs, and small changes in the precipitation relationship due to the bias corrections. Double mass curves also indicate changes in the cumulative precipitation over the study periods. This change leads to a smaller and inverted precipitation gradient across the border, representing a significant modification in the precipitation pattern over the northern region. Overall, this study discovers significant inconsistency in the precipitation measurements across the US and Canada border. This discontinuity is greater for snowfall than for rainfall, as gauge snowfall observations have large errors in the windy and cold conditions. This result will certainly impact regional, particularly cross borders, climate and hydrology investigations.

  4. Sufentanil citrate immobilization of Alaskan moose calves.

    Science.gov (United States)

    Kreeger, Terry J; Kellie, Kalin A

    2012-10-01

    Free-ranging Alaskan moose calves (Alces alces gigas) were immobilized with 0.12 mg/kg sufentanil (S; n=16), 0.12 mg/kg sufentanil plus 0.27 mg/kg xylazine (SX; n=11), or 0.007 mg/kg carfentanil plus 0.36 mg/kg xylazine (CX; n=13). Immobilants were antagonized with 1.2 mg/kg naltrexone (S) or 1.2 mg/kg naltrexone plus 2.4 mg/kg tolazoline (SX, CX). There were no differences in induction (P ≥ 0.29) or processing (P ≥ 0.44) times between groups. Moose given either S or SX had significantly shorter recovery times than moose given CX (P=0.001) and recovery times from S were shorter than from SX (P=0.02). Oxygen saturation values for all groups averaged 85 ± 8%, but were significantly higher (P=0.048) for CX (89 ± 7%) than for S (82 ± 8%). Based on these data, sufentanil at 0.1 mg/kg or sufentanil at 0.1 mg/kg plus xylazine at 0.25 mg/kg could provide effective remote immobilization for Alaskan moose calves and could be substituted for carfentanil or thiafentanil should the need arise.

  5. Juggling Educational Ends: Non-Indigenous Yukon Principals and the Policy Challenges that They Face

    Science.gov (United States)

    Blakesley, Simon

    2012-01-01

    This article reports on a 2008 study of non-indigenous principals working in indigenous Yukon contexts. It examines the policy contexts in which Yukon principals are embedded, giving attention to how they address the tensions that exist as a result of operating at the intersections of multiple policy levels. The application of critical ethnography…

  6. EarthScope Transportable Array (TA) Plans for Deployment in Alaska and Yukon

    Science.gov (United States)

    Hafner, K.; Busby, R. W.; Woodward, R.; Frassetto, A.

    2012-12-01

    The USArray portion of the National Science Foundation (NSF)-funded EarthScope project has been rolling across the continental United States from west to east since its construction began in October 2003. The Transportable Array (TA) element of Earthscope / USArray is a large deployment of 400 high quality broadband seismographs that is operated by the Incorporated Research Institutions for Seismology (IRIS) Consortium. The TA will reach the last installation in the eastern US in September 2013, after installing and operating 1678 stations. Following this ten-year deployment across the contiguous 48 US states and southernmost Canada the EarthScope USArray is expected to move to Alaska in 2014, contingent on a renewal proposal for the period FY14-FY18. The plan is to cover Alaska and parts of the Yukon Territory with approximately 300 stations at an 85 km grid-like spacing. The TA station grid will include about 35 existing seismic stations in Alaska. The NSF is currently supporting preparatory work to develop station design and communication concepts appropriate for the variable Alaska conditions. The siting of stations has been a focus of planning to-date, particularly the coordination with existing Alaskan seismic and GPS stations as well as Canadian stations. There is considerable interest in at least some of the stations becoming permanent assets to the existing station operators. We are also working on developing potential collaborative efforts with NOAA and other federal agencies, as well as groups conducting permafrost studies in the Arctic. We describe the station design, including modifications for long-term power and telemetry in remote regions. We have been testing sensor emplacement techniques that can be used across Alaska, particularly in regions of tundra underlain by permafrost, that will yield low horizontal noise at long periods. Results from several test stations are presented and the technique to emplace sensors is discussed. Feedback and

  7. Carbon cycle uncertainty in the Alaskan Arctic

    Directory of Open Access Journals (Sweden)

    J. B. Fisher

    2014-02-01

    Full Text Available Climate change is leading to a disproportionately large warming in the high northern latitudes, but the magnitude and sign of the future carbon balance of the Arctic are highly uncertain. Using 40 terrestrial biosphere models for Alaska, we provide a baseline of terrestrial carbon cycle structural and parametric uncertainty, defined as the multi-model standard deviation (σ against the mean (x for each quantity. Mean annual uncertainty (σ/x was largest for net ecosystem exchange (NEE (−0.01± 0.19 kg C m−2 yr−1, then net primary production (NPP (0.14 ± 0.33 kg C m−2 yr−1, autotrophic respiration (Ra (0.09 ± 0.20 kg C m−2 yr−1, gross primary production (GPP (0.22 ± 0.50 kg C m−2 yr−1, ecosystem respiration (Re (0.23 ± 0.38 kg C m−2 yr−1, CH4 flux (2.52 ± 4.02 g CH4 m−2 yr−1, heterotrophic respiration (Rh (0.14 ± 0.20 kg C m−2 yr−1, and soil carbon (14.0± 9.2 kg C m−2. The spatial patterns in regional carbon stocks and fluxes varied widely with some models showing NEE for Alaska as a strong carbon sink, others as a strong carbon source, while still others as carbon neutral. Additionally, a feedback (i.e., sensitivity analysis was conducted of 20th century NEE to CO2 fertilization (β and climate (γ, which showed that uncertainty in γ was 2x larger than that of β, with neither indicating that the Alaskan Arctic is shifting towards a certain net carbon sink or source. Finally, AmeriFlux data are used at two sites in the Alaskan Arctic to evaluate the regional patterns; observed seasonal NEE was captured within multi-model uncertainty. This assessment of carbon cycle uncertainties may be used as a baseline for the improvement of experimental and modeling activities, as well as a reference for future trajectories in carbon cycling with climate change in the Alaskan Arctic.

  8. Development of Alaskan gas hydrate resources

    Energy Technology Data Exchange (ETDEWEB)

    Kamath, V.A.; Sharma, G.D.; Patil, S.L.

    1991-06-01

    The research undertaken in this project pertains to study of various techniques for production of natural gas from Alaskan gas hydrates such as, depressurization, injection of hot water, steam, brine, methanol and ethylene glycol solutions through experimental investigation of decomposition characteristics of hydrate cores. An experimental study has been conducted to measure the effective gas permeability changes as hydrates form in the sandpack and the results have been used to determine the reduction in the effective gas permeability of the sandpack as a function of hydrate saturation. A user friendly, interactive, menu-driven, numerical difference simulator has been developed to model the dissociation of natural gas hydrates in porous media with variable thermal properties. A numerical, finite element simulator has been developed to model the dissociation of hydrates during hot water injection process.

  9. U-Pb zircon and geochemical evidence for bimodal mid-Paleozoic magmatism and syngenetic base-metal mineralization in the Yukon-Tanana terrane, Alaska

    Science.gov (United States)

    Dusel-Bacon, C.; Wooden, J.L.; Hopkins, M.J.

    2004-01-01

    New SHRIMP (sensitive, high-resolution ion microprobe) U-Pb zircon ages and trace element geochemical data for mafic and felsic metaigneous rocks of the pericratonic Yukon-Tanana terrane in east-central Alaska help define the tectonic setting of mid-Paleozoic magmatism and syngenetic hydrothermal Zn-Pb-Ag mineralization along the ancient Pacific margin of North America. We compare data from similar greenschist-facies sequences of bimodal volcanic and subvolcanic rocks associated with carbonaceous and siliciclastic marine sedimentary rocks, in the Wood River area of the Alaska Range and the Salcha River area of the Yukon-Tanana Upland, and from amphibolite-facies augen gneiss and mafic gneiss (amphibolite) in the Goodpaster River area of the upland. Allowing for analytical uncertainties, igneous crystallization age ranges of 376-353 Ma, 378-346 Ma, and 374-358 Ma are indicated by 13 new SHRIMP U-Pb dates for the Wood River, Salcha River, and Goodpaster River areas, respectively. Bimodal magmatism is indicated by Late Devonian crystallization ages for both augen gneiss (371 ?? 3 and 362 ?? 4 Ma) and associated orthoamphibolite (369 ?? 3 Ma) in the upland and by stratigraphic interleaving of mafic and felsic rocks in the Alaska Range. Metabasites in all three study areas have elevated HFSE (high field strength element) and REE (rare earth element) contents indicative of generation in a within-plate (extensional) tectonic setting. Within-plate trace element signatures also are indicated for peralkaline metarhyolites that host the largest volcanogenic massive sulfide deposits of the Bonnifield district in the Wood River area and for metarhyolite tuff interlayered with the carbonaceous Nasina assemblage, which hosts sedimentary exhalative sulfide occurrences in the Salcha River area. Most of the other felsic metaigneous samples from the Alaska Range and the Yukon-Tanana Upland have geochemical signatures that are similar to those of both average upper continental crust

  10. New porcellioidean gastropods from early Devonian of Royal Creek area, Yukon Territory, Canada, with notes on their early phylogeny

    Science.gov (United States)

    Fryda, J.; Blodgett, R.B.; Lenz, A.C.; Manda, S.

    2008-01-01

    This paper presents a description of new gastropods belonging to the superfamily Porcellioidea (Vetigastropoda) from the richly diverse Lower Devonian gastropod fauna of the Road River Formation in the Royal Creek area, Yukon Territory. This fauna belongs to Western Canada Province of the Old World Realm. The Pragian species Porcellia (Porcellia) yukonensis n. sp. and Porcellia (Paraporcellia) sp. represent the oldest presently known members of subgenera Porcellia (Porcellia) and Porcellia (Paraporcellia). Their simple shell ornamentation fits well with an earlier described evolutionary trend in shell morphology of the Porcellinae. Late Pragian to early Emsian Perryconcha pulchra n. gen. and n. sp. is the first member of the Porcellioidea bearing a row of tremata on adult teleoconch whorls. The occurrence of this shell feature in the Porcellioidea is additional evidence that the evolution of the apertural slit was much more complicated than has been proposed in classical models of Paleozoic gastropod evolution. Copyright ?? 2008, The Paleontological Society.

  11. The Current Tectonics of the Yukon and Adjacent Area

    Science.gov (United States)

    Hyndman, R. D.; Leonard, L. J.

    2014-12-01

    The current tectonics across the Yukon and adjacent areas of western Northwest Territories (NWT) and northern British Columbia appear to be driven primarily by the Yakutat Terrane collision, an "indenter" in the corner of the Gulf of Alaska. GPS data show 1-10 mm/yr northward and eastward, decreasing inland. The rates from earthquake statistics are similar although there are important discrepancies. The eastern Cordillera earthquake mechanisms are mainly thrust in the Mackenzie Mountains of southwestern NWT where the Cordillera upper crust is overthrusting the craton. To the north, the mechanisms are mainly strike-slip in the Richardson Mountains that appear to lie along the edge of the craton. The deformation appears to be limited to the hot and weak Cordillera with the strong craton providing an irregular eastern boundary. For example, there is an eastward bow in the craton edge and the deformation in the Mackenzie Mountains. On the Beaufort Sea margin in the region of the Mackenzie Delta there appears to be a type of "subduction zone" with the continent very slowly overthrusting the oceanic plate, a process that has continued since at least the Cretaceous. A northward moving continental margin block is bounded by left lateral faulting in the west (Canning Displacement Zone of eastern Alaska) and right lateral faulting in the east (Richardson Mountains in eastern Yukon). There is almost no seismicity on this thrust belt but as for some other subduction zones such as Cascadia there is the potential for very infrequent great earthquakes.

  12. Eastern Denali Fault Slip Rate and Paleoseismic History, Kluane Lake Area, Yukon Territory, Canada

    Science.gov (United States)

    Seitz, G. J.; Haeussler, P. J.; Crone, A. J.; Lipovsky, P.; Schwartz, D. P.

    2008-12-01

    In 2002, the central part of the dextral-slip Denali fault (DF) system generated a M 7.9 earthquake in central Alaska. This rupture included the section of the Denali fault with the highest measured late Pleistocene slip rate, of 12.1±1.7 mm/yr, and the Totschunda fault, with a slip rate of 6.0±1.2 mm/yr. Immediately east of the Denali-Totschunda fault juncture, the slip rate on the eastern Denali fault (EDF) decreases to 8.4±2.2 mm/yr. We present observations of Holocene fault activity on the Yukon part of the EDF (Shakwak segment), which is located about 280 km southeast of the Denali-Totschunda intersection in the vicinity of Kluane Lake. Aerial reconnaissance in 2007, from the Denali-Totschunda fault juncture to the Kluane Lake region revealed a nearly continuously identifiable fault trace, which is occasionally obscured where it is subparallel to glacial landforms. In addition to geomorphic features associated with strike-slip faults, such as shutter ridges and sag ponds, the fault is commonly expressed by a chain of elongate mounds, likely tectonic pushups, 20-70 m in length, 10-50 m wide, and locally up to 10 m high. These appear to have formed by shortening between en echelon left-stepping fault strands that developed in layered glacial sediments. At one location (61°18'30.12" N, 139°01'02.54"W) we measured on the ground a channel offset of 20-25 m. An aerial view showed that other channels in the vicinity, as well as the margins of two mounds, were offset by similar amounts. These channels likely developed after deglaciation 10-12 ka. Using this age and the offset yields a slip-rate range of 1.7-2.5 mm/yr, a minimum value but one that may be close to the actual rate. However, because of uncertainties in age relations between construction of the uplift mounds and channel incision the offset could be younger and we estimate an upper limit of about 5 mm/yr. Adjacent to and south of the Duke River, an approximately 2-km-long section of the fault is

  13. Yukon Flats National Wildlife Refuge: Comprehensive Conservation Plan, Environmental Impact Statement, and Wilderness Review

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is the final Comprehensive Conservation Plan (CCP), Environmental Impact Statement (EIS), and Wilderness Review (WR) for the Yukon Flats National...

  14. Yukon's green power initiative and support for wind

    Energy Technology Data Exchange (ETDEWEB)

    Sinclair, D. [Yukon Development Corp., Whitehorse, YK (Canada)

    2002-07-01

    Yukon's green power initiative is aimed at increasing the production and sale of small-scale renewable energy to meet the requirements of communities and industry while reducing greenhouse gas emissions. The territorial government has created a 10 year, $5 million investment fund including wind research and development. The objective is to replace diesel production and reduce emissions, provide consumers with green power options and improve the cost-effectiveness and long-term competitiveness. Targeted measures led by the Yukon Energy Corporation include: a commercial scale wind installation at Haeckel Hill near Whitehorse; a community wind resource assessment program; pilot and demonstration projects; technical capacity building; and, joint ventures with Yukon First Nations. The utility is providing leadership by allowing access to electricity markets through the generation of franchises and by providing flexible financing through corporate investment led by Yukon Development Corporation. 1 fig.

  15. Archeological investigations on the Yukon-Kuskokwim Delta, S. W. Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is a report on the archeological investigation on the Yukon-Kuskokwim Delta. This report specifically examines the native people's cultural heritage. The...

  16. An evaluation of goose productivity on the Yukon Delta NWR, Alaska: A summary report, 1984

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Ten field crews documented the nesting chronology, sources and magnitude of predation, and productivity of arctic nesting geese on the Yukon-Kuskokwim delta from...

  17. Population structure and productivity of whistling swans on the Yukon-Kuskokwim Delta, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Observations on the Yukon - Delta whistling swan population were recorded for the nine year period 1963 to 1971 (Lensink, 1973). Data recorded here, collected during...

  18. Yukon Flats National Wildlife Refuge: Annual narrative report: Calendar year 1995

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yukon Flats National Wildlife Refuge outlines Refuge accomplishments during the 1995 calendar year. The report begins with a...

  19. Population age composition, breeding biology and notes on the wolverine in Alaska and Yukon Territory

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report describes the population age, composition, breeding biology and notes on the wolverine in Alaska and the Yukon territory. Life history, physical...

  20. Alaska-Yukon: Waterfowl breeding pair survey: May 20 to June 14, 1977

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Breeding Population and Habitat Survey for Alaska-Yukon during 1977. The primary purpose of the survey is to provide information...

  1. Synoptic Variability of Extreme Snowfall in the St. Elias Mountains, Yukon, Canada

    OpenAIRE

    Andin, Caroline

    2015-01-01

    Glaciers of southwestern Yukon (Canada) and southeastern Alaska (USA) are presently experiencing high rates of annual mass loss. These high melt rates have mainly been investigated with respect to regional temperature trends, but comparatively little is known about how climate variations regulate snow accumulation on these glaciers. This study examines the synoptic weather patterns and air flow trajectories associated with extreme snowfall events in the central St. Elias Mountains (Yukon). Th...

  2. Factors affecting Yukon teen pregnancy decline in the mid and late 1990s.

    Science.gov (United States)

    Wackett, Jeff

    2002-11-01

    Teen pregnancy has declined throughout North America in the 1990s. In Yukon Territory, Canada, teen pregnancy in the late 1990s was almost 40% lower than in the early 1990s. This rate of decline is significantly greater than most recently reported national rates of teen pregnancy decline in Canada and United States. Identifying possible causes of the Yukon decline may help policy makers and program managers plan and implement teen pregnancy prevention strategies. Data on Yukon teen pregnancy prevention initiatives were collected through numerous discussions and interviews with Yukon service providers, teens, and the general public between 1994 and 2001. Analysis of data demonstrates that multiple new initiatives spanning many sectors were implemented in the mid and late 1990s that could have contributed to the decline in Yukon teen pregnancy. A multi-dimensional approach to teen pregnancy prevention that included researching and evaluating family planning programs and policies before, during, and after implementation, increasing access to longer-acting hormonal contraceptives, providing continuing family planning medical education to health care providers and other youth service providers, subsidization of contraceptives, delivery of innovative family planning mass media campaigns, and delivery of ongoing sexual health education programs may have significantly contributed to the decline in Yukon teen pregnancy. Collaboration among service providers across many service sectors (clinical, public health, education, First Nations, government communication and policy, grassroots) facilitated coordination of the multi-dimensional approach.

  3. Semiautomatic mapping of permafrost in the Yukon Flats, Alaska

    Science.gov (United States)

    Gulbrandsen, Mats Lundh; Minsley, Burke J.; Ball, Lyndsay B.; Hansen, Thomas Mejer

    2016-12-01

    Thawing of permafrost due to global warming can have major impacts on hydrogeological processes, climate feedback, arctic ecology, and local environments. To understand these effects and processes, it is crucial to know the distribution of permafrost. In this study we exploit the fact that airborne electromagnetic (AEM) data are sensitive to the distribution of permafrost and demonstrate how the distribution of permafrost in the Yukon Flats, Alaska, is mapped in an efficient (semiautomatic) way, using a combination of supervised and unsupervised (machine) learning algorithms, i.e., Smart Interpretation and K-means clustering. Clustering is used to sort unfrozen and frozen regions, and Smart Interpretation is used to predict the depth of permafrost based on expert interpretations. This workflow allows, for the first time, a quantitative and objective approach to efficiently map permafrost based on large amounts of AEM data.

  4. Wolf predation in the Burwash caribou herd, southwest Yukon

    Directory of Open Access Journals (Sweden)

    David A. Gauthier

    1986-06-01

    Full Text Available The role of wolf predation as a proximate mortality factor influencing caribou herd growth was assessed in the Burwash herd (400 animals in the southwest Yukon between 1980 - 1982. Ten to 14 wolves in two packs preyed primarily on caribou (Rangifer tarandus caribou and moose (Alces alces with disproportionate consumption of caribou (relative to available biomass in the rut and winter periods. Wolf predation was responsible for 72% of total annual mortality in 1980 - 1981 and 46% in 1981 - 1982. Losses due to human harvest varied between 7 to 13%. Additional limited data on climatic factors and winter forage indicated forage-climate were not major proximate mortality factors in 1980 - 1981, but that early-calving climate may have been a factor in increased calf mortality in 1982.

  5. Recent U.S. Geological Survey Studies in the Tintina Gold Province, Alaska, United States, and Yukon, Canada-Results of a 5-Year Project

    Science.gov (United States)

    Gough, Larry P.; Day, Warren C.

    2010-01-01

    This report presents summary papers of work conducted between 2002 and 2007 under a 5-year project effort funded by the U.S. Geological Survey Mineral Resources Program, formerly entitled 'Tintina Metallogenic Province: Integrated Studies on Geologic Framework, Mineral Resources, and Environmental Signatures.' As the project progressed, the informal title changed from 'Tintina Metallogenic Province' project to 'Tintina Gold Province' project, the latter being more closely aligned with the terminology used by the mineral industry. As Goldfarb and others explain in the first chapter of this report, the Tintina Gold Province is a convenient term used by the mineral exploration community for a 'region of very varied geology, gold deposit types, and resource potential'. The Tintina Gold Province encompasses roughly 150,000 square kilometers, bounded by the Kaltag-Tintina fault system on the north and the Farewell-Denali fault system on the south. It extends westward in a broad arc, some 200 km wide, from northernmost British Columbia, through the Yukon, through southeastern and central Alaska, to southwestern Alaska. The climate is subarctic and, in Alaska, includes major physiographic delineations and ecoregions such as the Yukon-Tanana Upland, Tanana-Kuskokwim Lowlands, Yukon River Lowlands, and the Kuskokwim Mountains. Although the Tintina Gold Province is historically important for some of the very first placer and lode gold discoveries in northern North America, it has recently seen resurgence in mineral exploration, development, and mining activity. This resurgence is due to both new discoveries (for example, Pogo and Donlin Creek) and to the application of modern extraction methods to previously known, but economically restrictive, low-grade, bulk-tonnage gold resources (for example, Fort Knox, Clear Creek, and Scheelite Dome). In addition, the Tintina Gold Province hosts numerous other mineral deposit types, possessing both high and low sulfide content, which

  6. Effects of the Oil Spill on Alaskan Education.

    Science.gov (United States)

    Oldaker, Lawrence Lee

    Oil-industry-produced revenues, help finance Alaskan state and local governmental services including education. Capital losses incurred by the Exxon Corporation and by commerical fisheries as a consequence of the Exxon Valdez oil spill caused an economic recession, the result being diminished financing for a number of governmental programs and…

  7. STARS (Secondary Training for Alaskan Rural Students): Mathematics. Draft Copy.

    Science.gov (United States)

    Griffin, Ned; Ostrom, Robert

    STARS (Secondary Training for Alaskan Rural Students) materials resulted from extensive rewriting of the Vocational Adult Secondary Training (VAST) materials produced by the British Columbia Department of Education, after those materials had been used with the 9th and 10th graders on Kodiak Island. Revision was done by teachers who had been using…

  8. Late Pleistocene and Holocene tephrostratigraphy of interior Alaska and Yukon: Key beds and chronologies over the past 30,000 years

    Science.gov (United States)

    Davies, Lauren J.; Jensen, Britta J. L.; Froese, Duane G.; Wallace, Kristi L.

    2016-08-01

    The Aleutian Arc-Alaska Peninsula and Wrangell volcanic field are the main source areas for tephra deposits found across Alaska and northern Canada, and increasingly, tephra from these eruptions have been found further afield in North America, Greenland, and Europe. However, there have been no broad scale reviews of the Late Pleistocene and Holocene tephrostratigraphy for this region since the 1980s, and this lack of data is hindering progress in identifying these tephra both locally and regionally. To address this gap and the variable quality of associated geochemical and chronological data, we undertake a detailed review of the latest Pleistocene to Holocene tephra found in interior Alaska and Yukon. This paper discusses nineteen tephra that have distributions beyond southwest Alaska and that have the potential to become, or already are, important regional markers. This includes three 'modern' events from the 20th century, ten with limited data availability but potentially broad distributions, and six that are widely reported in interior Alaska and Yukon. Each tephra is assessed in terms of chronology, geochemistry and distribution, with new Bayesian age estimates and geochemical data when possible. This includes new major-element geochemical data for Crater Peak 1992, Redoubt 1989-90, and two andesitic tephra from St Michael Island (Tephra D), as well as revised age estimates for Dawson tephra, Oshetna, Hayes set H, Aniakchak CFE II, and the White River Ashes, northern and eastern lobes.

  9. Characteristics of discontinuous permafrost, Southern Yukon Territory, Canada

    Science.gov (United States)

    Etzelmueller, B.; Lewkowicz, A. G.; Smith, S.

    2009-04-01

    Two-dimensional DC resistivity profiling was used to examine the characteristics of shallow permafrost at three lowland and eight mountain sites in the southern Yukon Territory. Ground temperatures from logged thermistor cables or annual manual readings were available for most of the sites. Frost table depths along the transects also helped constrain the interpretations. Ground temperatures at or close to the depth of zero annual amplitude were all warmer than -0.5°C. Interpreted permafrost depths were generally less than 10 m but reached 25 m at one location. Sites with coarse materials showed sharp transitions in resistivity values at the base of permafrost while those in fine-grained materials showed gradational boundaries, interpreted as being due to progressively increasing unfrozen moisture contents close to 0°C. There were large differences in the relative resistivity values for frozen and unfrozen ground but the absolute values for permafrost were lower than many others reported in the literature for mountain sites. The DC resistivity technique proved to be extremely useful in characterizing the distribution and continuity of frozen ground at these shallow and sensitive permafrost sites and provided a baseline data-set for monitoring future change.

  10. River

    Directory of Open Access Journals (Sweden)

    Morel Mathieu

    2016-01-01

    Full Text Available The OECD report “Boosting Resilience through Innovative Risk Governance” examines the efforts of OECD countries to prevent or reduce future disaster impacts, and highlights several key areas where improvements can be made. International collaboration is insufficiently utilised to address shocks that have increasingly global consequences. Institutional design plays a significant role in facilitating or hampering the engagement and investments of governmental and non-governmental stakeholders in disaster risk prevention and mitigation. To inform the design of “better” institutions, the OECD proposes the application of a diagnostic framework that helps governments identify institutional shortcomings and take actions to improve them. The goal of the case study on the Rhone River is to conduct an analysis of the progress, achievements and existing challenges in designing and implementing disaster risk reduction strategies through the Rhone Plan from a comparative perspective across a set of selected countries of this study, like Austria and Switzerland, will inform how to improve institutional frameworks governing risk prevention and mitigation. The case study will be used to identify examples of successful practice taking into account their specific country contexts, and analyse their potential for policy transfer.

  11. Using remotely-sensed nearshore suspended sediment as an indicator of environmental change on the Alaskan North Slope

    Science.gov (United States)

    Hobson, Anne Carrie Hickey

    The effects of climate change are increasing the vulnerability the delicate Arctic system on the North Slope of Alaska. Concurrently, oil and gas development is projected to expand across the region, the wide-scale effects of which are largely unknown in a less-resilient system. This research provides the framework for using satellite data to assess and monitor suspended sediment conditions in the nearshore Alaskan Beaufort Sea, which provide a key indicator of environmental change. Satellite monitoring of suspended sediment levels provides a cost-effective means to obtain nearly real-time, synoptic information about environmental change on the North Slope. This information can be incorporated into cumulative effects analyses and enhance their capability to assess and predict the environmental effects of oil and gas development in a changing climate. Surface reflectance data from the Moderate Resolution Imaging Spectroradiometer (MODIS) and Advanced Very High Resolution Radiometer (AVHRR) sensors were calibrated to total suspended sediment (TSS) concentrations in the Alaskan Beaufort Sea and used to construct time series of proxy TSS data for 2000--2005 and 1981--2004, respectively. These time series produced a baseline quantifying the interannual variability and 24-year trends in median annual TSS concentrations at locations in the nearshore Alaskan Beaufort Sea. Increasing trends over the analysis period were identified in the outflow areas of the Ikpikpuk, Colville, Kuparuk and Sagavanirktok Rivers, as well as in Admiralty Bay. Additionally, TSS levels in 1994 and 2000 exceeded the normal range of variability at several of the nearshore locations investigated. Different areas along the nearshore had varying TSS magnitudes and modes of variability, a function of the terrestrial and nearshore processes controlling TSS conditions at each location. An empirical model explained 65 percent of the variability in annual median TSS values using precipitation factors that

  12. Leaders' perspectives in the Yellowstone to Yukon Conservation Initiative

    Science.gov (United States)

    Mattson, D.J.; Clark, S.G.; Byrd, K.L.; Brown, S.R.; Robinson, B.

    2011-01-01

    The Yellowstone to Yukon Conservation Initiative (Y2Y) was created in 1993 to advance conservation in a 1.2 million km2 portion of the North American Rocky Mountains. We assembled 21 people with influence over Y2Y in a workshop to elucidate perspectives on challenges and solutions for this organization at a key point in its evolution, and used Q method to define four perspectives on challenges and three on solutions. Participants were differentiated by four models for effecting change-vision-based advocacy, practice-based learning, political engagement, and scientific management-with emphasis on the first three. Those with authority in Y2Y aligned with vision-based advocacy and expressed ambivalence about practice-based adaptive learning and rigorous appraisals of existing strategies. Workshop results were consistent with an apparent trend toward organizational maturation focused on stabilizing revenues, developing formal organizational arrangements, and focusing strategies. Consolidation of power in Y2Y around a long-standing formula does not bode well for the effectiveness of Y2Y. We recommend that leaders in Y2Y and similar organizations focused on large-scale conservation to create and maintain an open system-philosophically and operationally-that capitalizes on the diverse perspectives and skills of individuals who are attracted to such efforts. We also recommend that the Y2Y initiative be followed closely to harvest additional lessons for potential application to large-scale conservation efforts elsewhere. ?? Springer Science+Business Media, LLC(outside the USA).2011.

  13. Effect of permafrost thaw on the dynamics of lakes recharged by ice-jam floods: case study in Yukon Flats, Alaska

    Science.gov (United States)

    Steve M. Jepsen,; Walvoord, Michelle Ann; Voss, Clifford I.; Rover, Jennifer R.

    2015-01-01

    Large river floods are a key water source for many lakes in fluvial periglacial settings. Where permeable sediments occur, the distribution of permafrost may play an important role in the routing of floodwaters across a floodplain. This relationship is explored for lakes in the discontinuous permafrost of Yukon Flats, interior Alaska, using an analysis that integrates satellite-derived gradients in water surface elevation, knowledge of hydrogeology, and hydrologic modeling. We observed gradients in water surface elevation between neighboring lakes ranging from 0.001 to 0.004. These high gradients, despite a ubiquitous layer of continuous shallow gravel across the flats, are consistent with limited groundwater flow across lake basins resulting from the presence of permafrost. Permafrost impedes the propagation of floodwaters in the shallow subsurface and constrains transmission to “fill-and-spill” over topographic depressions (surface sills), as we observed for the Twelvemile-Buddy Lake pair following a May 2013 ice-jam flood on the Yukon River. Model results indicate that permafrost table deepening of 1–11 m in gravel, depending on watershed geometry and subsurface properties, could shift important routing of floodwater to lakes from overland flow (fill-and-spill) to shallow groundwater flow (“fill-and-seep”). Such a shift is possible in the next several hundred years of ground surface warming, and may bring about more synchronous water level changes between neighboring lakes following large flood events. This relationship offers a potentially useful tool, well-suited to remote sensing, for identifying long-term changes in shallow groundwater flow resulting from thawing of permafrost.

  14. 36 CFR 223.10 - Free use to Alaskan settlers, miners, residents, and prospectors.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Free use to Alaskan settlers, miners, residents, and prospectors. 223.10 Section 223.10 Parks, Forests, and Public Property FOREST... § 223.10 Free use to Alaskan settlers, miners, residents, and prospectors. Bona fide settlers,...

  15. Our Stories about Teaching and Learning: A Pedagogy of Consequence for Yukon First Nation Settings

    Science.gov (United States)

    Lewthwaite, Brian; Owen, Thomas; Doiron, Ashley; McMillan, Barbara; Renaud, Robert

    2013-01-01

    In this study, First Nation community members in Canada's Yukon Territory share their stories about teaching and learning, both in informal and formal settings, in an effort to identify practices that might serve teachers to be more responsive to their First Nation students. In all, 52 community members between the ages of 15 and 82 shared their…

  16. Curriculum Change and Self-Governing Agreements: A Yukon First Nation Case Study

    Science.gov (United States)

    Lewthwaite, Brian Ellis; Owen, Thomas; Doiron, Ashley

    2015-01-01

    Recent developments in Canada's Yukon Territory draw attention to how political changes have potential for accelerating practices in education that are responsive to Indigenous Peoples' cultural knowledge systems and practices. In this study, through the use of case study methodology, an account of the changes that have occurred in one First…

  17. Pleistocene Permafrost Thawing History of Alaska, the Yukon, and the Northwest Territories from U-Th Dating of Cave Speleothems

    Science.gov (United States)

    Biller, N.; Shakun, J. D.; McGee, D.; Hardt, B. F.; Ford, D.; Lauriol, B.

    2015-12-01

    Permafrost, or permanently frozen ground, is widespread in the Arctic and contains twice as much carbon as the atmosphere in the form of frozen organic matter. This carbon may be vulnerable to thaw and release to the atmosphere as methane under a warming climate, making permafrost thaw one of the potentially most significant amplifying feedbacks to anthropogenic warming. Nonetheless, permafrost can be slow to respond to warming, the short instrumental record may not adequately capture long-term trends, and the modest temperature changes of the past few millennia provide poor analogues to understand the possibility of crossing climate thresholds in the next century or beyond. One way to address this problem is to assess the stability of permafrost during previous interglacial periods of varying levels of warmth, which provide natural experiments to examine the Arctic's sensitivity to warming. Cave speleothems in the Arctic are relics of past periods of thaw that enabled meteoric water to seep into caves and deposit calcite. We employed uranium-thorium (U-Th) dating to constrain the chronology and extent of permafrost thaw in the North American Arctic during the past 600,000 years. We sampled caves from a range of permafrost zones and latitudes, including the Fishing Branch Territorial Park, Yukon (66.5°N, continuous permafrost), White Mountains National Recreation Area, Alaska (65°N, discontinuous permafrost), Yukon-Charley Rivers National Preserve, Alaska (64.5°N, discontinuous permafrost), and Nahanni National Park Reserve, Northwest Territories (62°N, discontinuous permafrost). Thirty-five samples from 30 speleothems have been analyzed at this point, with 23 samples lying beyond the U-Th dating range, and finite ages tending to cluster near Marine Isotope Stage 11 (MIS 11) within uncertainty, as well as perhaps MIS 9, 13, and 15. This preliminary dataset, coupled with a similar study in Siberia (Vaks et al., 2013), is thus suggestive of an episode of

  18. Status of northern mountain caribou (Rangifer tarandus caribou in Yukon, Canada

    Directory of Open Access Journals (Sweden)

    Troy M. Hegel

    2013-06-01

    Full Text Available Normal 0 21 false false false SV X-NONE X-NONE Caribou (Rangifer tarandus are an important ecological, cultural and economic resource in Yukon, Canada. Three caribou ecotypes occur within Yukon: Grant’s (R. t. granti, northern mountain (R. t. caribou, and boreal (R. t. caribou. Northern mountain caribou are classified as a species of special concern under Canada’s Species at Risk Act, and a national management plan for northern mountain caribou was recently completed. Twenty-six northern mountain caribou herds occur at least partially within Yukon, representing approximately 30,000 – 35,000 animals. Active monitoring of Yukon’s northern mountain caribou began in earnest in the early 1980s. To date, over 200 fall composition surveys have been carried out, over 1000 animals have been fitted with radio-collars, and nearly 40 formal population estimates have been completed. Disease and contaminant monitoring of these caribou has indicated relatively low disease prevalence and contaminant loading. Northern mountain caribou are harvested in Yukon, with an average of 230 caribou harvested per year by licensed hunters (1995 – 2012 and an unknown number by First Nation hunters. Future challenges related to caribou management and conservation in Yukon include increasing levels of industrial development primarily through mineral exploration and development, ensuring harvest of these herds is conducted sustainably given the absence of total harvest information, inter-jurisdictional management of shared herds, existing uncertainty surrounding herd distribution and delineation, and dealing with vehicle-related mortality of caribou for certain herds. Overall, the population status (i.e., trend of eight herds is known, with two increasing, two decreasing, and four stable.

  19. Nesting success of geese in the coastal tundra region of the Yukon-Kuskokwim Delta, 1985 final report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Progress was made in 1985 towards development of sampling methods to provide an unbiased estimate of annual production by geese nesting on the Yukon-Kuskokwim Delta,...

  20. Contaminant Case Report: Spectacled eider (Somateria fischeri) eggs and feathers from the Yukon-Kuskokwim Delta, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — We collected spectacled eider (Somateria fischeri) eggs and shed breast contour feathers from nests on the Yukon-Kuskokwim Delta, Alaska, in 1992 to evaluate...

  1. An evaluation based on goose nesting density of certain native land in holdings on the Yukon-Kuskokwim delta

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In the fall of 1986, inquiries were made to research biologists working on the Yukon-Kuskokwim (Y-K) Delta concerning data that might help establish the value of...

  2. Arctic geese during brood-rearing on the central Yukon-Kuskokwim Delta: Analysis of patterns of distribution: Annual report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In July 1985 two systematic aerial surveys were flown over the coastal fringe of the central Yukon-Kuskokwim Delta, Alaska, to examine the patterns of distribution...

  3. Yukon Delta National Wildlife Refuge : Land Conservation Plan : Options for the protection of fish and wildlife habitats

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This LCP explores the effects of private lands on Yukon Delta NWR resources, and provides an opportunity to discuss key refuge issues and ways the Service can work...

  4. Pre-burn small mammal survey of the Yukon Flats National Wildlife Refuge: YFNWR project report number 86-3

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Yukon Flats National Wildlife Refuge has scheduled a prescribed burn for summer 1986 in an area known as The Buttes Gap. Reestablishing fire into the northern...

  5. YFNWR project report number 85-3: Beaver food cache survey, Yukon Flats National Wildlife Refuge, Alaska: Management study

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The objective of the annual beaver food cache survey is to determine trends in the relative abundance of beaver in representative drainages within the Yukon Flats...

  6. Population size and production of geese and eiders nesting on the Yukon-Kuskokwim Delta, Alaska in 1998

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Annual assessment of nesting populations of geese on the Yukon-Kuskokwim Delta(YKD) provides information for biologists, participants in cooperative goose...

  7. Phlorotannins from Alaskan Seaweed Inhibit Carbolytic Enzyme Activity

    Directory of Open Access Journals (Sweden)

    Joshua Kellogg

    2014-10-01

    Full Text Available Global incidence of type 2 diabetes has escalated over the past few decades, necessitating a continued search for natural sources of enzyme inhibitors to offset postprandial hyperglycemia. The objective of this study was to evaluate coastal Alaskan seaweed inhibition of α-glucosidase and α-amylase, two carbolytic enzymes involved in serum glucose regulation. Of the six species initially screened, the brown seaweeds Fucus distichus and Alaria marginata possessed the strongest inhibitory effects. F. distichus fractions were potent mixed-mode inhibitors of α-glucosidase and α-amylase, with IC50 values of 0.89 and 13.9 μg/mL, respectively; significantly more efficacious than the pharmaceutical acarbose (IC50 of 112.0 and 137.8 μg/mL, respectively. The activity of F. distichus fractions was associated with phlorotannin oligomers. Normal-phase liquid chromatography-mass spectrometry (NPLC-MS was employed to characterize individual oligomers. Accurate masses and fragmentation patterns confirmed the presence of fucophloroethol structures with degrees of polymerization from 3 to 18 monomer units. These findings suggest that coastal Alaskan seaweeds are sources of α-glucosidase and α-amylase inhibitory phlorotannins, and thus have potential to limit the release of sugar from carbohydrates and thus alleviate postprandial hyperglycemia.

  8. Molecular investigations into a globally important carbon pool: Permafrost-protected carbon in Alaskan soils

    Science.gov (United States)

    Waldrop, M.P.; Wickland, K.P.; White, Rickie; Berhe, A.A.; Harden, J.W.; Romanovsky, V.E.

    2010-01-01

    The fate of carbon (C) contained within permafrost in boreal forest environments is an important consideration for the current and future carbon cycle as soils warm in northern latitudes. Currently, little is known about the microbiology or chemistry of permafrost soils that may affect its decomposition once soils thaw. We tested the hypothesis that low microbial abundances and activities in permafrost soils limit decomposition rates compared with active layer soils. We examined active layer and permafrost soils near Fairbanks, AK, the Yukon River, and the Arctic Circle. Soils were incubated in the lab under aerobic and anaerobic conditions. Gas fluxes at -5 and 5 ??C were measured to calculate temperature response quotients (Q10). The Q10 was lower in permafrost soils (average 2.7) compared with active layer soils (average 7.5). Soil nutrients, leachable dissolved organic C (DOC) quality and quantity, and nuclear magnetic resonance spectroscopy of the soils revealed that the organic matter within permafrost soils is as labile, or even more so, than surface soils. Microbial abundances (fungi, bacteria, and subgroups: methanogens and Basidiomycetes) and exoenzyme activities involved in decomposition were lower in permafrost soils compared with active layer soils, which, together with the chemical data, supports the reduced Q10 values. CH4 fluxes were correlated with methanogen abundance and the highest CH4 production came from active layer soils. These results suggest that permafrost soils have high inherent decomposability, but low microbial abundances and activities reduce the temperature sensitivity of C fluxes. Despite these inherent limitations, however, respiration per unit soil C was higher in permafrost soils compared with active layer soils, suggesting that decomposition and heterotrophic respiration may contribute to a positive feedback to warming of this eco region. Published 2010. This article is a US Government work and is in the public domain in the

  9. Drilling and Testing the DOI041A Coalbed Methane Well, Fort Yukon, Alaska

    Science.gov (United States)

    Clark, Arthur; Barker, Charles E.; Weeks, Edwin P.

    2009-01-01

    The need for affordable energy sources is acute in rural communities of Alaska where costly diesel fuel must be delivered by barge or plane for power generation. Additionally, the transport, transfer, and storage of fuel pose great difficulty in these regions. Although small-scale energy development in remote Arctic locations presents unique challenges, identifying and developing economic, local sources of energy remains a high priority for state and local government. Many areas in rural Alaska contain widespread coal resources that may contain significant amounts of coalbed methane (CBM) that, when extracted, could be used for power generation. However, in many of these areas, little is known concerning the properties that control CBM occurrence and production, including coal bed geometry, coalbed gas content and saturation, reservoir permeability and pressure, and water chemistry. Therefore, drilling and testing to collect these data are required to accurately assess the viability of CBM as a potential energy source in most locations. In 2004, the U.S. Geological Survey (USGS) and Bureau of Land Management (BLM), in cooperation with the U.S. Department of Energy (DOE), the Alaska Department of Geological and Geophysical Surveys (DGGS), the University of Alaska Fairbanks (UAF), the Doyon Native Corporation, and the village of Fort Yukon, organized and funded the drilling of a well at Fort Yukon, Alaska to test coal beds for CBM developmental potential. Fort Yukon is a town of about 600 people and is composed mostly of Gwich'in Athabascan Native Americans. It is located near the center of the Yukon Flats Basin, approximately 145 mi northeast of Fairbanks.

  10. Looking Forward: Using Scenario Modeling to Support Regional Land Use Planning in Northern Yukon, Canada

    Directory of Open Access Journals (Sweden)

    Jeff Hamm

    2011-12-01

    Full Text Available Regional land use planning provides opportunities for governments, land users, and stakeholders to consider multiple land and resource interests over large geographic areas and meaningful time periods. The broad and integrative nature of regional planning is therefore well suited to assessing the potential cumulative effects of current and future land use activity. For this reason, cumulative effects assessment models and management concepts are playing an increasingly important role in regional planning. We describe how the ALCES® landscape cumulative effects simulation model was used to explore possible outcomes of an oil and gas scenario in the Eagle Plain basin of the North Yukon Planning Region of Yukon Territory, Canada. Scenario modeling was conducted to facilitate informed discussion about key land use issues and practices, potential levels of landscape change, and possible socioeconomic benefits and environmental impacts. Modeling results supported the sustainable development and cumulative effects management recommendations of the North Yukon Regional Land Use Plan. Land use scenario modeling, as applied in this project, was found to be an effective approach for establishing sustainable development guidelines through a regional planning process.

  11. Reporting and sealing regulations for Alaskan natives, a proposed rule: Report on public attitudes

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report covers the proposed reporting and sealing regulations for Alaskan natives- a report on public attitudes. At the direction of the U.S. congress, the...

  12. Traditional use of sea otters by Alaskan natives: A literature review

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The references cited in this report leave no doubt that sea otter fur was commonly used for clothing by all Alaskan natives who lived in contact with populations of...

  13. Biocorrosive Thermophilic Microbial Communities in Alaskan North Slope Oil Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, Kathleen E.; Gieg, Lisa M.; Parisi, Victoria A.; Tanner, Ralph S.; Green Tringe, Susannah; Bristow, Jim; Suflita, Joseph M.

    2009-09-16

    Corrosion of metallic oilfield pipelines by microorganisms is a costly but poorly understood phenomenon, with standard treatment methods targeting mesophilic sulfatereducing bacteria. In assessing biocorrosion potential at an Alaskan North Slope oil field, we identified thermophilic hydrogen-using methanogens, syntrophic bacteria, peptideand amino acid-fermenting bacteria, iron reducers, sulfur/thiosulfate-reducing bacteria and sulfate-reducing archaea. These microbes can stimulate metal corrosion through production of organic acids, CO2, sulfur species, and via hydrogen oxidation and iron reduction, implicating many more types of organisms than are currently targeted. Micromolar quantities of putative anaerobic metabolites of C1-C4 n-alkanes in pipeline fluids were detected, implying that these low molecular weight hydrocarbons, routinely injected into reservoirs for oil recovery purposes, are biodegraded and provide biocorrosive microbial communities with an important source of nutrients.

  14. Development of Alaskan gas hydrate resources. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kamath, V.A.; Sharma, G.D.; Patil, S.L.

    1991-06-01

    The research undertaken in this project pertains to study of various techniques for production of natural gas from Alaskan gas hydrates such as, depressurization, injection of hot water, steam, brine, methanol and ethylene glycol solutions through experimental investigation of decomposition characteristics of hydrate cores. An experimental study has been conducted to measure the effective gas permeability changes as hydrates form in the sandpack and the results have been used to determine the reduction in the effective gas permeability of the sandpack as a function of hydrate saturation. A user friendly, interactive, menu-driven, numerical difference simulator has been developed to model the dissociation of natural gas hydrates in porous media with variable thermal properties. A numerical, finite element simulator has been developed to model the dissociation of hydrates during hot water injection process.

  15. Air-cushion tankers for Alaskan North Slope oil

    Science.gov (United States)

    Anderson, J. L.

    1973-01-01

    A concept is described for transporting oil from the Arctic to southern markets in 10,000-ton, chemically fueled air-cushion vehicles (ACV's) configured as tankers. Based on preliminary cost estimates the conceptual ACV tanker system as tailored to the transportation of Alaskan North Slope oil could deliver the oil for about the same price per barrel as the proposed trans-Alaska pipeline with only one-third of the capital investment. The report includes the description of the conceptual system and its operation; preliminary cost estimates; an appraisal of ACV tanker development; and a comparison of system costs, versatility, vulnerability, and ecological effect with those of the trans-Alaska pipeline.

  16. Report of Alaska waterfowl investigations, summer 1941, lower Yukon River, Chevak, Hooper Bay

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Investigated Hooper Bay, Chevak, Inland, Kashunuk village, areas. Covers mammals, birds, plants, vegetation, harvest and hunting, predation, marine mammals, climate,...

  17. Environmental Engineering and Ecological Baseline Investigations along the Yukon River-Prudhoe Bay Haul Road.

    Science.gov (United States)

    1980-09-01

    20 8. Generalized bedrock types encountered along the Haul Road 22 9. Vegetation classification of sites 44 10. New and interesting bryophytes and...Galbraith Lake to the Sagwon bluffs, and a sedge-meadow type on the Coastal Plain. Differentiation of this region from the Coastal Riparian habitats ...area, tamarack (Larix laric- Coastal Plain. Riparian habitats , late-lying snow- ina) can be an occasional component on wetter beds, rock outcrops and

  18. Modeling and Dynamic Monitoring of Ecosystem Performance in the Yukon River Basin

    Science.gov (United States)

    Wylie, B.K.; Zhang, L.; Ji, L.; Tieszen, L.L.; Bliss, N.B.

    2008-01-01

    Central Alaska is ecologically sensitive and experiencing stress in response to marked regional warming. Resource managers would benefit from an improved ability to monitor ecosystem processes in response to climate change, fire, insect damage, and management policies and to predict responses to future climate scenarios. We have developed a method for analyzing ecosystem performance as represented by the growing season integral of normalized difference vegetation index (NDVI), which is a measure of greenness that can be interpreted in terms of plant growth or photosynthetic activity (gross primary productivity). The approach illustrates the status and trends of ecosystem changes and separates the influences of climate and local site conditions from the influences of disturbances and land management. We emphasize the ability to quantify ecosystem processes, not simply changes in land cover, across the entire period of the remote sensing archive (Wylie and others, 2008). The method builds upon remotely sensed measures of vegetation greenness for each growing season. By itself, however, a time series of greenness often reflects annual climate variations in temperature and precipitation. Our method seeks to remove the influence of climate so that changes in underlying ecological conditions are identified and quantified. We define an 'expected ecosystem performance' to represent the greenness response expected in a particular year given the climate of that year. We distinguish 'performance anomalies' as cases where the ecosystem response is significantly different from the expected ecosystem performance. Maps of the performance anomalies (fig. 1) and trends in the anomalies give valuable information on the ecosystems for land managers and policy makers at a resolution of 1 km to 250 m.

  19. AFSC/ABL: Stock composition, timing, and spawning distribution of Yukon River Chinook salmon

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Radio telemetry was used to determine the distribution, locate spawning sites, and evaluate the tagging response of wild Chinook salmon Oncorhynchus tshawytscha...

  20. Yukon Delta National Wildlife Refuge general biological inventory, Eek River, 1985

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report is about a general biological inventory done in June and July 1985. A three-person field crew completed a general biological inventory of the Eek Rivet...

  1. Winter speed-up of ice flow at quiescent surge-type glaciers in Yukon, Canada

    Science.gov (United States)

    Furuya, M.; Abe, T.

    2013-12-01

    Glacier surge exhibits order-of-magnitude faster velocity and km-scale terminus advance during its short active phase after a long quiescent period. The observations of glacier surge are still limited, and the mechanisms of glacier surge cycle remain elusive. Moreover, with the exception of several well-examined glaciers, the glacier dynamics during their quiescent periods remains even more uncertain due to the paucity of surface velocity measurement data. Here we examined spatial-temporal changes in the ice surface velocity of surge-type glaciers in the St. Elias Mountains near the border of Alaska and Yukon during the period from December 2006 to March 2011. We applied the offset-tracking (feature-tracking) technique to the L-band synthetic aperture radar (SAR) images derived from the Japanese Advanced Land Observation Satellite (ALOS). The Chitina, Anderson, Walsh, and Logan Glaciers, the major subpolar surge-type glaciers of the Chitina River valley system, could be examined with the highest temporal resolution because of the overlap of multiple satellite tracks. We have found significant upstream accelerations from fall to winter at a number of glaciers during their quiescence. Moreover, whereas the upstream propagating summer speed-up was observed, the winter speed-up propagated from upstream to downglacier. Although the winter speed-up seems to be at odds with the well-known summer speed-up, these observations are consistent with the fragmentary but well-known fact of glacier surge that often initiates in winter, suggesting that some of the mechanisms would be valid even during quiescent phases. Ice surface velocity at mountain glaciers and ice sheets typically exhibits the greatest acceleration from spring to early summer, followed by deceleration in mid-summer to fall, and is slowest in winter. These short-term velocity changes are attributed to subglacial slip associated with water pressure changes that occur because of the seasonal variability of

  2. Brief Communication: Twelve-year cyclic surging episode at Donjek Glacier in Yukon, Canada

    Directory of Open Access Journals (Sweden)

    T. Abe

    2015-11-01

    Full Text Available Surge-type glaciers repeat their short active phase and much longer quiescent phase usually every several decades or longer, but detailed observations of the evolution cycles have been limited to a few glaciers. Here we report three surging episodes in 1989, 2001, and 2013 at Donjek Glacier in the Yukon, indicating remarkably regular and short repeat cycles of 12 years. The surging area is limited within the ~ 20 km section from the terminus, where the flow width significantly narrows than upstream, suggesting a strong control of the valley constriction on the surge dynamics.

  3. Brief Communication: Twelve-year cyclic surging episodes at Donjek Glacier in Yukon, Canada

    Science.gov (United States)

    Abe, Takahiro; Furuya, Masato; Sakakibara, Daiki

    2016-07-01

    Surge-type glaciers repeat their short active phase and their much longer quiescent phase usually every several decades or longer, but detailed observations of the evolution cycles have been limited to only a few glaciers. Here we report three surging episodes in 1989, 2001, and 2013 at Donjek Glacier in the Yukon, Canada, indicating remarkably regular and short repeat cycles of 12 years. The surging area is limited within the ˜ 20 km section from the terminus, originating in an area where the flow width significantly narrows downstream, suggesting a strong control of the valley constriction on the surge dynamics.

  4. Brief Communication: Twelve-year cyclic surging episode at Donjek Glacier in Yukon, Canada

    Science.gov (United States)

    Abe, T.; Furuya, M.; Sakakibara, D.

    2015-11-01

    Surge-type glaciers repeat their short active phase and much longer quiescent phase usually every several decades or longer, but detailed observations of the evolution cycles have been limited to a few glaciers. Here we report three surging episodes in 1989, 2001, and 2013 at Donjek Glacier in the Yukon, indicating remarkably regular and short repeat cycles of 12 years. The surging area is limited within the ~ 20 km section from the terminus, where the flow width significantly narrows than upstream, suggesting a strong control of the valley constriction on the surge dynamics.

  5. A Formal Messaging Notation for Alaskan Aviation Data

    Science.gov (United States)

    Rios, Joseph L.

    2015-01-01

    Data exchange is an increasingly important aspect of the National Airspace System. While many data communication channels have become more capable of sending and receiving data at higher throughput rates, there is still a need to use communication channels efficiently with limited throughput. The limitation can be based on technological issues, financial considerations, or both. This paper provides a complete description of several important aviation weather data in Abstract Syntax Notation format. By doing so, data providers can take advantage of Abstract Syntax Notation's ability to encode data in a highly compressed format. When data such as pilot weather reports, surface weather observations, and various weather predictions are compressed in such a manner, it allows for the efficient use of throughput-limited communication channels. This paper provides details on the Abstract Syntax Notation One (ASN.1) implementation for Alaskan aviation data, and demonstrates its use on real-world aviation weather data samples as Alaska has sparse terrestrial data infrastructure and data are often sent via relatively costly satellite channels.

  6. Leaf cuticular lipids on the Shandong and Yukon ecotypes of saltwater cress, Eutrema salsugineum, and their response to water deficiency and impact on cuticle permeability.

    Science.gov (United States)

    Xu, Xiaojing; Feng, Jinchao; Lü, Shiyou; Lohrey, Greg T; An, Huiling; Zhou, Yijun; Jenks, Matthew A

    2014-08-01

    The impact of water-deficit stress on leaf cuticular waxes and cutin monomers, and traits associated with cuticle permeability were examined in Shandong and Yukon ecotypes of Eutrema salsugineum (syn. Thellungiella salsuginea). Although Shandong exhibits glaucous leaves, and Yukon is non-glaucous, wax amounts on non-stressed Yukon leaves were 4.6-fold higher than on Shandong, due mainly to Yukon's eightfold higher wax fatty acids, especially the C22 and C24 acid homologues. Water deficit caused a 26.9% increase in total waxes on Shandong leaves, due mainly to increased C22 and C24 acids; and caused 10.2% more wax on Yukon, due mainly to an increase in wax alkanes. Total cutin monomers on non-stressed leaves of Yukon were 58.3% higher than on Shandong. Water deficit caused a 28.2% increase in total cutin monomers on Shandong, whereas total cutin monomers were not induced on Yukon. With or without stress, more abundant cuticle lipids were generally associated with lower water loss rates, lower chlorophyll efflux rates and an extended time before water deficit-induced wilting. In response to water deficit, Shandong showed elevated transcription of genes encoding elongase subunits, consistent with the higher stress induction of acids by Shandong. Yukon's higher induction of CER1 and CER3 transcripts may explain why alkanes increased most on Yukon after water deficit. Eutrema, with its diverse cuticle lipids and responsiveness, provides a valuable genetic resource for identifying new genes and alleles effecting cuticle metabolism, and lays groundwork for studies of the cuticle's role in extreme stress tolerance.

  7. A Harbour Porpoise, Phocoena phocoena (Linnaeus, 1758), from the Mackenzie River delta, Northwest Territories, Canada (Notes on Cetacea, Delphinoidea VIII)

    NARCIS (Netherlands)

    Bree, van P.J.H.; Sergeant, D.E.; Hoek, W.

    1977-01-01

    A Harbour Porpoise, Phocoena phocoena, taken from near Shallow Bay, Mackenzie River Delta, Northwest Territories (68°48’ N 136°35’ W) in July 1973 represents a range extension 800 km eastwards from the previous extreme northeastern record on the north Alaskan coast. All 12 Harbour Porpoises so far e

  8. Culturally Responsive Teaching in Yukon First Nation Settings: What Does It Look Like and What Is Its Influence?

    Science.gov (United States)

    Lewthwaite, Brian; Owen, Thomas; Doiron, Ashley; Renaud, Robert; McMillan, Barbara

    2014-01-01

    This study presents a pedagogical framework to inform culturally responsive teaching in a Yukon First Nations community. The paper describes the community-based processes used to develop the framework, and presents accounts from teachers who have used the framework to inform their teaching. Preliminary indications of the adjusted teaching…

  9. 78 FR 35957 - Notice of Intent To Prepare a Resource Management Plan for the Central Yukon Planning Area Alaska...

    Science.gov (United States)

    2013-06-14

    ... Planning Area Alaska and Associated Environmental Impact Statement AGENCY: Bureau of Land Management... on issues, planning criteria, and management questions and concerns related to the Central Yukon RMP... wildlife management. 8. The RMP will be consistent with the Bureau's H-1601-1 Land Use Planning...

  10. A genetic dissection of breed composition and performance enhancement in the Alaskan sled dog

    Directory of Open Access Journals (Sweden)

    Runstadler Jonathan

    2010-07-01

    Full Text Available Abstract Background The Alaskan sled dog offers a rare opportunity to investigate the development of a dog breed based solely on performance, rather than appearance, thus setting the breed apart from most others. Several established breeds, many of which are recognized by the American Kennel Club (AKC, have been introduced into the sled dog population to enhance racing performance. We have used molecular methods to ascertain the constitutive breeds used to develop successful sled dog lines, and in doing so, determined the breed origins of specific performance-related behaviors. One hundred and ninety-nine Alaskan sled dogs were genotyped using 96 microsatellite markers that span the canine genome. These data were compared to that from 141 similarly genotyped purebred dog breeds. Sled dogs were evaluated for breed composition based on a variety of performance phenotypes including speed, endurance and work ethic, and the data stratified based on population structure. Results We observe that the Alaskan sled dog has a unique molecular signature and that the genetic profile is sufficient for identifying dogs bred for sprint versus distance. When evaluating contributions of existing breeds we find that the Alaskan Malamute and Siberian Husky contributions are associated with enhanced endurance; Pointer and Saluki are associated with enhanced speed and the Anatolian Shepherd demonstrates a positive influence on work ethic. Conclusion We have established a genetic breed profile for the Alaskan sled dog, identified profile variance between sprint and distance dogs, and established breeds associated with enhanced performance attributes. These data set the stage for mapping studies aimed at finding genes that are associated with athletic attributes integral to the high performing Alaskan sled dog.

  11. The influence of hydrology and waterway distance on population structure of Chinook salmon Oncorhynchus tshawytscha in a large river.

    Science.gov (United States)

    Olsen, J B; Beacham, T D; Wetklo, M; Seeb, L W; Smith, C T; Flannery, B G; Wenburg, J K

    2010-04-01

    Adult Chinook salmon Oncorhynchus tshawytscha navigate in river systems using olfactory cues that may be influenced by hydrologic factors such as flow and the number, size and spatial distribution of tributaries. Thus, river hydrology may influence both homing success and the level of straying (gene flow), which in turn influences population structure. In this study, two methods of multivariate analysis were used to examine the extent to which four indicators of hydrology and waterway distance explained population structure of O. tshawytscha in the Yukon River. A partial Mantel test showed that the indicators of hydrology were positively associated with broad-scale (Yukon basin) population structure, when controlling for the influence of waterway distance. Multivariate multiple regression showed that waterway distance, supplemented with the number and flow of major drainage basins, explained more variation in broad-scale population structure than any single indicator. At an intermediate spatial scale, indicators of hydrology did not appear to influence population structure after accounting for waterway distance. These results suggest that habitat changes in the Yukon River, which alter hydrology, may influence the basin-wide pattern of population structure in O. tshawytscha. Further research is warranted on the role of hydrology in concert with waterway distance in influencing population structure in Pacific salmon.

  12. Assessing hazard risk, cost of adaptation and traditional land use activities in the context of permafrost thaw in communities in Yukon and the Northwest Territories, Canada

    Science.gov (United States)

    Benkert, B.; Perrin, A.; Calmels, F.

    2015-12-01

    Together with its partners, the Northern Climate ExChange (NCE, part of the Yukon Research Centre at Yukon College) has been mapping permafrost-related hazard risk in northern communities since 2010. By integrating geoscience and climate project data, we have developed a series of community-scale hazard risk maps. The maps depict hazard risk in stoplight colours for easy interpretation, and support community-based, future-focused adaptation planning. Communities, First Nations, consultants and local regulatory agencies have used the hazard risk maps to site small-scale infrastructure projects, guide land planning processes, and assess suitability of land development applications. However, we know that assessing risk is only one step in integrating the implications of permafrost degradation in societal responses to environmental change. To build on our permafrost hazard risk maps, we are integrating economic principles and traditional land use elements. To assess economic implications of adaptation to permafrost change, we are working with geotechnical engineers to identify adaptation options (e.g., modified building techniques, permafrost thaw mitigation approaches) that suit the risks captured by our existing hazard risk maps. We layer this with an economic analysis of the costs associated with identified adaptation options, providing end-users with a more comprehensive basis upon which to make decisions related to infrastructure. NCE researchers have also integrated traditional land use activities in assessments of permafrost thaw risk, in a project led by Jean Marie River First Nation in the Northwest Territories. Here, the implications of permafrost degradation on food security and land use priorities were assessed by layering key game and gathering areas on permafrost thaw vulnerability maps. Results indicated that close to one quarter of big and small game habitats, and close to twenty percent of key furbearer and gathering areas within the First Nation

  13. Report to the Pacific Flyway Committee on 1985-2004 Coastal Zone Yukon-Kuskokwim Delta Goose Survey of geese, swans and sandhill cranes

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Aerial surveys of geese, tundra swans and sandhill cranes were conducted in the coastal zone of the Yukon-Kuskokwim Delta (YKD) for the 20th consecutive year. The...

  14. Report to the Pacific Flyway Committee on 1985-2002 Coastal Zone Yukon-Kuskokwim Delta Goose Survey of geese, swans and sandhill cranes

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Aerial surveys of geese, tundra swans and sandhill cranes were conducted in the coastal zone of the Yukon-Kuskokwim Delta (YKD) for the 18th consecutive year. The...

  15. Waterfowl populations, production and habitat ecology on the Yukon-Kuskokwim Delta, Alaska: Population and ecology of cackling geese: Progress report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is a progress report on the waterfowl populations, production and habitat ecology on the Yukon-Kuskokwim Delta, Alaska, specifically the populations and ecology...

  16. YFNWR project report number 86-4: The feasibility of a proposed study to estimate beaver abundance on the Yukon Flats National Wildlife Refuge: Management study

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A survey was conducted for the Yukon Flats National Wildlife Refuge (YFNWR) in summer 1985 to assess the feasibility of a proposed study to estimate beaver colony...

  17. Understanding the Complex Dimensions of the Digital Divide: Lessons Learned in the Alaskan Arctic

    Science.gov (United States)

    Subramony, Deepak Prem

    2007-01-01

    An ethnographic case study of Inupiat Eskimo in the Alaskan Arctic has provided insights into the complex nature of the sociological issues surrounding equitable access to technology tools and skills, which are referred to as the digital divide. These people can overcome the digital divide if they get the basic ready access to hardware and…

  18. Using Technology To Educate Deaf and Hard of Hearing Children in Rural Alaskan General Education Settings.

    Science.gov (United States)

    Pillai, Patrick

    1999-01-01

    A survey of 79 teachers of Alaskan students with deafness found those who use instructional technology tended to be older, hold an advanced degree and secondary education certification, benefit from in-service training onsite, are connected to the Internet, and actively use the technology available at their schools. (Contains references.)…

  19. 77 FR 45921 - Alaskan Fuel Hauling as a Restricted Category Special Purpose Flight Operation

    Science.gov (United States)

    2012-08-02

    ... the Federal Register (74 FR 39242) in which the FAA proposed to specify Alaskan fuel hauling as a... Purpose Flight Operation AGENCY: Federal Aviation Administration (FAA), (DOT). ACTION: Notice of policy... submitted was, ``The transport of the fuel could be made safer by limiting the payload on each flight to...

  20. EXAMINATION OF THE FEASIBILITY FOR DEMONSTRATION AND USE OF RADIOLUMINESCENT LIGHTS FOR ALASKAN REMOTE RUNWAY LIGHTING

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, G.; Perrigo, L.; Leonard, L.; Hegdal, L

    1984-01-01

    This report examines the feasibility of radioluminescent light applications for rural Alaskan airports. The work presented in this report covers four tasks: State of the Art Evaluation of Radioluminescent Lights, Environmental, Radiological, and Regulatory Evaluations, Engineering Evaluations, and Demonstration Plan Development.

  1. Program Demand Cost Model for Alaskan Schools. 6th Edition. Revised.

    Science.gov (United States)

    Alaska State Dept. of Education, Juneau.

    The Program Demand Cost Model for Alaskan Schools (Cost Model) is a tool for use by school districts and their consultants in estimating school construction costs in the planning phase of a project. This document sets out the sixth edition of the demand-cost model, a rewrite of the whole system. The model can be used to establish a complete budget…

  2. Petroleum systems of the Alaskan North Slope: a numerical journey from source to trap

    Science.gov (United States)

    Lampe, C.; Peters, K.E.; Magoon, L.B.; Bird, K.J.; Lillis, P.G.

    2003-01-01

    The complex petroleum province of the Alaskan North Slope contains six petroleum systems (Magoon and others, this session). Source rocks for four of these systems include the Hue-gamma ray zone (Hue-GRZ), pebble shale unit, Kingak Shale, and Shublik Formation. Geochemical data for these source rocks are investigated in greater detail and provide the basis for numerical petroleum migration models.

  3. Intensive Evaluation of Satellite TV Impact on Four Alaskan Villages. Supplement to Basic ESCD Evaluation Design.

    Science.gov (United States)

    Practical Concepts, Inc., Washington, DC.

    A supplement to the final report, "Design for an Analysis and Assessment of the Education Satellite Communications Demonstration (ESCD)," this document is both: (1) a separable, sociologically oriented evaluation of the ESCD impact on Alaskan native villages; and (2) a direct extension of the work described in sections 4 and 5 in the…

  4. Alaskan glaciers: Recent observations in respect to the earthquake-advance theory

    Science.gov (United States)

    Post, A.S.

    1965-01-01

    Preliminary aerial photographic studies indicate that the Alaskan earthquake produced some rockfalls but no significant snow and ice avalanches on glaciers. No rapid, short-lived glacier advances (surges) are conclusively associated with this earthquake. Recent evidence fails to support the earthquake-advance theory of Tarr and Martin.

  5. Bioaccumulation of petroleum hydrocarbons in arctic amphipods in the oil development area of the Alaskan Beaufort Sea.

    Science.gov (United States)

    Neff, Jerry M; Durell, Gregory S

    2012-04-01

    An objective of a multiyear monitoring program, sponsored by the US Department of the Interior, Bureau of Ocean Energy Management was to examine temporal and spatial changes in chemical and biological characteristics of the Arctic marine environment resulting from offshore oil exploration and development activities in the development area of the Alaskan Beaufort Sea. To determine if petroleum hydrocarbons from offshore oil operations are entering the Beaufort Sea food web, we measured concentrations of hydrocarbons in tissues of amphipods, Anonyx nugax, sediments, Northstar crude oil, and coastal peat, collected between 1999 and 2006 throughout the development area. Mean concentrations of polycyclic aromatic hydrocarbons (PAH), saturated hydrocarbons (SHC), and sterane and triterpane petroleum biomarkers (StTr) were not significantly different in amphipods near the Northstar oil production facility, before and after it came on line in 2001, and in amphipods from elsewhere in the study area. Forensic analysis of the profiles (relative composition and concentrations) of the 3 hydrocarbon classes revealed that hydrocarbon compositions were different in amphipods, surface sediments where the amphipods were collected, Northstar crude oil, and peat from the deltas of 4 North Slope rivers. Amphipods and sediments contained a mixture of petrogenic, pyrogenic, and biogenic PAH. The SHC in amphipods were dominated by pristane derived from zooplankton, indicating that the SHC were primarily from the amphipod diet of zooplankton detritus. The petroleum biomarker StTr profiles did not resemble those in Northstar crude oil. The forensic analysis revealed that hydrocarbons in amphipod tissues were not from oil production at Northstar. Hydrocarbons in amphipod tissues were primarily from their diet and from river runoff and coastal erosion of natural diagenic and fossil terrestrial materials, including seep oils, kerogens, and peat. Offshore oil and gas exploration and development

  6. Winter speed-up of quiescent surge-type glaciers in Yukon, Canada

    Science.gov (United States)

    Abe, T.; Furuya, M.

    2015-06-01

    Glacier surges often initiate in winter, but the mechanism remains unclear in contrast to the well-known summer speed-up at normal glaciers. To better understand the mechanism, we used radar images to examine spatial-temporal changes in the ice velocity of surge-type glaciers near the border of Alaska and the Yukon, focusing on their quiescent phase. We found significant accelerations in the upstream region from autumn to winter, regardless of surging episodes. Moreover, the winter speed-up propagated from upstream to downstream. Given the absence of surface meltwater input in winter, we suggest the presence of water storage near the base that does not directly connect to the surface, yet can promote basal sliding through increased water pressure. Our findings have implications for the modelling of glacial hydrology in winter, which may help us better understand glacier dynamics.

  7. Winter speed-up of quiescent surge-type glaciers in Yukon, Canada

    Directory of Open Access Journals (Sweden)

    T. Abe

    2014-05-01

    Full Text Available Glacier surge is known to often initiate in winter, but the mechanisms remain unclear in light of the summer speed-up at normal glaciers. We examined spatial-temporal changes in the ice velocity of surge-type glaciers near the border of Alaska and Yukon, and found significant upstream accelerations from fall to winter, regardless of surging episodes. Moreover, whereas the summer speed-up was observed downstream, the winter speed-up propagated from upstream to downglacier. Given the absence of upstream surface meltwater input in winter, we speculate the presence of water storages near the base that do not directly connect to the surface but can promote basal sliding through increased water pressure as winter approaches. Our findings have implications for modeling of glacial hydrology in winter time, and its link to glacier dynamics and subglacial erosion.

  8. Cadmium, mercury and selenium concentrations in mink (Mustela vison) from Yukon, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Gamberg, Mary [Gamberg Consulting, Box 10460, Whitehorse, Yukon, Y1A 7A1 (Canada)]. E-mail: mary.gamberg@northwestel.net; Boila, Gail [Freshwater Institute, Fisheries and Oceans Canada, 501 University Crescent, Winnipeg, MB, R3T 2N6 (Canada); Stern, Gary [Freshwater Institute, Fisheries and Oceans Canada, 501 University Crescent, Winnipeg, MB, R3T 2N6 (Canada); Roach, Patrick [Department of Indian and Northern Affairs, Suite 300, 300 Main Street, Whitehorse, Yukon, Y1A 2B5 (Canada)

    2005-12-01

    Mercury (total and methyl), cadmium and selenium concentrations were measured in liver, kidney and brain tissue from mink trapped from the Yukon Territory from 2001-2002. None of these metals was found at levels of toxicological concern. Total mercury averaged 0.66, 0.92 and 0.22 {mu}g g{sup -1} in mink kidney, liver and brain tissue respectively, while methyl mercury averaged 0.77, 0.85 and 0.21 {mu}g g{sup -1} in the same tissues. Selenium averaged 2.07, 1.40 and 0.39 {mu}g g{sup -1} in mink kidney, liver and brain tissue, while cadmium was only measured in kidneys and averaged 0.22 {mu}g g{sup -1}. All element concentrations are presented on a wet weight basis. Concentrations of total mercury in all tissues were significantly higher in female than male mink, possibly reflecting proportionally greater food consumption by the smaller females. Total mercury concentrations were inversely related to the proportion of mercury present as methylmercury, and positively related to concentrations of selenium, consistent with increasing demethylation of methylmercury, and the formation of mercuric selenide as total concentrations of mercury increased. This relationship was seen most strongly in mink liver, less so in kidneys and not at all in brains where most of the mercury was maintained in the methyl form. There did not appear to be any geographical areas in which mink had obviously higher concentrations of mercury, and there was frequently a relatively large range of mercury levels found in mink from a given trapline. Mink diet may be a factor in this variation. Local environmental levels of cadmium were not reflected in cadmium concentrations in mink tissues. Mercury, cadmium and selenium do not appear to constitute environmental hazards to mink in the Yukon.

  9. A Guide to Alaskan Black Spruce Wetland Bryophytes: Species Specific to Delineation for Interior and South Central Regions

    Science.gov (United States)

    2008-06-01

    many habitats . Often mixed with other bryophytes . Similar to both P. proligera and P. annotina, but differs in the leaf base that is not decurrent...E R D C / C R R E L T N - 0 8 - 2 A Guide to Alaskan Black Spruce Wetland Bryophytes Species Specific to...SUBTITLE A Guide to Alaskan Black Spruce Wetland Bryophytes 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d

  10. Present-day strain partitioning and strain transfer across the Fairweather and Denali Faults in SW Yukon - SE Alaska

    Science.gov (United States)

    Mazzotti, S.; Marechal, A.; Elliott, J.; Freymueller, J. T.; Schmidt, M.

    2012-12-01

    In SW Yukon - SE Alaska, the present-day Pacific - North America relative motion is highly oblique to the main plate boundary, resulting in strong strain partitioning tectonics that link the Aleutian subduction to the west to Queen-Charlotte transform to the south. This transition region is also the site of present-day orogeny and accretion of the allochthonous Yakutat Terrane to the Northern Cordillera. We present results from new campaign and permanent GPS stations deployed in SW Yukon, combined with STEEP data from SE Alaska, straddling the Fairweather and Denali Faults. GPS data are processed with the NRCan PPP software to derive long-term velocities and are corrected for transient effects primarily due to Glacial Isostatic Adjustment to recent ice mass loss. In the southern region (from Yakutat, AK to Whitehorse, YK), our preferred model gives slip rates of 49.9 +/- 2.6 mm/a on the Fairweather Fault and 1.1 +/- 1.0 mm/a on the Denali Fault; i.e., over 95% the Pacific - North America strike-slip motion is accommodated on the main plate-boundary fault. However, the fault-normal component is strongly partitioned, with ~25% of the Pacific - North America convergence transferred inland, into the Yukon and Northern Cordillera. This strain transfer could explain the seismicity observed in the Mackenzie Mountains 500 - 800 km from the coast. In the northern region (from Yakutat, AK to Beaver Creek, YK), the Pacific - North America convergence is strongly partitioned, with less than ~60% accommodated on the Chugach-St. Elias Fault and the residual motion distributed between the Pamplona thrust zone to the south (~15%) and internal shortening of the St. Elias Mountains to the north (~25%), where few faults and little seismicity are observed. The new GPS data also helps address the activity and slip rate of a potential "Connector Fault" that would link the Fairweather and Totschunda Faults, bypassing the Denali Fault in SW Yukon.

  11. Coal and oil shale of Early Carboniferous age in northern Canada - significance for paleoenvironmental and paleoclimatic interpretations. [Canada - Northwest Territories and Yukon Territory

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, A.R.; Goodarzi, F.; Potter, J. (Geological Survey of Canada, Calgary, AB (Canada))

    1994-01-01

    Lower Carboniferous (Mississippian) coal beds and oil shale occur at several locations in northern Canada. In the northern Yukon Territory coal of semi-anthracite/anthracite rank occurs in the Kayak Formation in the British Mountains and at Hoidahl Dome near the headwaters of Blow River. Farther south in the Liard Basin, Northwest Territories, coals of high volatile bituminous rank occur in the Mattson Formation. In the Arctic Islands thicker beds of the Emma Fiord Formation, the oldest unit in the Sverdrup Basin, contain thin coal seams and oil shale on Devon Island, near the southern edge of the basin and on Axel Heiberg and Ellesmere islands on the north side of the basin. Organic matter in the Devon Island section is at a low maturity level (R[sub o, max] % 0.26-0.50), whereas that from Ellesmere and Axel Heiberg has reached the level of meta-anthracite. Depositional environments for these carbonaceous sediments were different. The coal-bearing Kayak strata accumulated in a coastal plain setting overlain transgressively by younger marine beds. The Mattson coal beds appear to have formed in a prograding delta, but coal and oil shale in the Emma Ford were deposited in lacustrine environments in a rift basin. These Canadian occurrences resemble penecontemporaneous deposits in Svalbard and elsewhere, adjacent to the present-day Arctic Ocean. They formed at low latitudes where conditions were favourable for the preservation of carbonaceous matter. Prior to the opening of the Arctic Ocean basin in Mesozoic times, sites on the mainland were undoubtedly closer to sites in the Arctic Islands than they are today.

  12. Clinical pathology and assessment of pathogen exposure in southern and Alaskan sea otters

    Science.gov (United States)

    Hanni, K.D.; Mazet, J.A.K.; Gulland, F.M.D.; Estes, James; Staedler, M.; Murray, M.J.; Miller, M.; Jessup, David A.

    2003-01-01

    The southern sea otter (Enhydra lutris nereis) population in California (USA) and the Alaskan sea otter (E. lutris kenyoni) population in the Aleutian Islands (USA) chain have recently declined. In order to evaluate disease as a contributing factor to the declines, health assessments of these two sea otter populations were conducted by evaluating hematologic and/or serum biochemical values and exposure to six marine and terrestrial pathogens using blood collected during ongoing studies from 1995 through 2000. Samples from 72 free-ranging Alaskan, 78 free-ranging southern, and (for pathogen exposure only) 41 debilitated southern sea otters in rehabilitation facilities were evaluated and compared to investigate regional differences. Serum chemistry and hematology values did not indicate a specific disease process as a cause for the declines. Statistically significant differences were found between free-ranging adult southern and Alaskan population mean serum levels of creatinine kinase, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, calcium, cholesterol, creatinine, glucose, phosphorous, total bilirubin, blood urea nitrogen, and sodium. These were likely due to varying parasite loads, contaminant exposures, and physiologic or nutrition statuses. No free-ranging sea otters had signs of disease at capture, and prevalences of exposure to calicivirus, Brucella spp., and Leptospira spp. were low. The high prevalence (35%) of antibodies to Toxoplasma gondii in free-ranging southern sea otters, lack of antibodies to this parasite in Alaskan sea otters, and the pathogen's propensity to cause mortality in southern sea otters suggests that this parasite may be important to sea otter population dynamics in California but not in Alaska. The evidence for exposure to pathogens of public health importance (e.g., Leptospira spp., T. gondii) in the southern sea otter population, and the nai??vete?? of both populations to other pathogens (e

  13. Twelve-year cyclic surging episode at Donjek Glacier in Yukon, Canada

    Science.gov (United States)

    Furuya, M.; Abe, T.; Sakakibara, D.

    2015-12-01

    Surge-type glaciers exhibit several-fold to orders-of-magnitude speed-up during the short active phase, resulting in km-scale terminus advance. Although there are many surge-type glaciers near the border of Alaska and the Yukon, the generation mechanisms remain uncertain because of limited and few continuous observations. To better understand the surge dynamics and predict the next event, it is essential to examine the entire surge cycles. Here we use Landsat optical imageries to reveal the long-term evolutions, and report three surging episodes at Donjek Glacier in Yukon, Canada. Using the Landsat images, we found three surging events in 1989, 2001, and 2013. In the 2001 event, the surface speed significantly increased by up to 4.5 m/d; during the quiescent phases it was ~0.5 m/d at the terminus. While the duration of active phase is about 4~5 and 2~3 year in the 2001 and 2013 events, the period in the 1989 event is unclear because of the lack of high temporal resolution data. Remarkably, the surging area is limited to the ~20-km section from the terminus instead of the entire glacier. Moreover, we examined the terminus area changes from 1975 to 2014. Although the area has been secularly decreasing probably due to the tread of global warming, it has also revealed four significant fluctuations during the nearly forty years. Comparing the speed and the area changes, the three speed-up events correspond to the terminus area fluctuations with a few time lags. It turns out that the surge event has been quite regularly repeating every twelve years. Although the behavior is rather similar to that in Svalbard glaciers in terms of maximum speed and unclear initiation season, the recurrence interval is much shorter than other nearby surges. Considering that the surge events seem to have initiated around significantly narrower area than upstream, the strong valley constriction may control the regularity as well as the twelve-year recurrence time.

  14. Long-term climate patterns in Alaskan surface temperature and precipitation and their biological consequences

    Science.gov (United States)

    Simpson, James J.; Hufford, Gary L.; Fleming, Michael D.; Berg, Jared S.; Ashton, J.B.

    2002-01-01

    Mean monthly climate maps of Alaskan surface temperature and precipitation produced by the parameter-elevation regression on independent slopes model (PRISM) were analyzed. Alaska is divided into interior and coastal zones with consistent but different climatic variability separated by a transition region; it has maximum interannual variability but low long-term mean variability. Pacific decadal oscillation (PDO)- and El Nin??o southern oscillation (ENSO)-type events influence Alaska surface temperatures weakly (1-2 ??C) statewide. PDO has a stronger influence than ENSO on precipitation but its influence is largely localized to coastal central Alaska. The strongest influence of Arctic oscillation (AO) occurs in northern and interior Alaskan precipitation. Four major ecosystems are defined. A major eco-transition zone occurs between the interior boreal forest and the coastal rainforest. Variability in insolation, surface temperature, precipitation, continentality, and seasonal changes in storm track direction explain the mapped ecosystems. Lack of westward expansion of the interior boreal forest into the western shrub tundra is influenced by the coastal marine boundary layer (enhanced cloud cover, reduced insolation, cooler surface and soil temperatures). In this context, the marine boundary layer acts in an analogous fashion to the orographic features which form the natural boundaries of other Alaskan ecosystems. Variability in precipitation may play a secondary role.

  15. Viability of the Alaskan breeding population of Steller’s eiders

    Science.gov (United States)

    Dunham, Kylee; Grand, James B.

    2016-10-11

    The U.S. Fish and Wildlife Service is tasked with setting objective and measurable criteria for delisting species or populations listed under the Endangered Species Act. Determining the acceptable threshold for extinction risk for any species or population is a challenging task, particularly when facing marked uncertainty. The Alaskan breeding population of Steller’s eiders (Polysticta stelleri) was listed as threatened under the Endangered Species Act in 1997 because of a perceived decline in abundance throughout their nesting range and geographic isolation from the Russian breeding population. Previous genetic studies and modeling efforts, however, suggest that there may be dispersal from the Russian breeding population. Additionally, evidence exists of population level nonbreeding events. Research was conducted to estimate population viability of the Alaskan breeding population of Steller’s eiders, using both an open and closed model of population process for this threatened population. Projections under a closed population model suggest this population has a 100 percent probability of extinction within 42 years. Projections under an open population model suggest that with immigration there is no probability of permanent extinction. Because of random immigration process and nonbreeding behavior, however, it is likely that this population will continue to be present in low and highly variable numbers on the breeding grounds in Alaska. Monitoring the winter population, which includes both Russian and Alaskan breeding birds, may offer a more comprehensive indication of population viability.

  16. Task 27 -- Alaskan low-rank coal-water fuel demonstration project

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-10-01

    Development of coal-water-fuel (CWF) technology has to-date been predicated on the use of high-rank bituminous coal only, and until now the high inherent moisture content of low-rank coal has precluded its use for CWF production. The unique feature of the Alaskan project is the integration of hot-water-drying (HWD) into CWF technology as a beneficiation process. Hot-water-drying is an EERC developed technology unavailable to the competition that allows the range of CWF feedstock to be extended to low-rank coals. The primary objective of the Alaskan Project, is to promote interest in the CWF marketplace by demonstrating the commercial viability of low-rank coal-water-fuel (LRCWF). While commercialization plans cannot be finalized until the implementation and results of the Alaskan LRCWF Project are known and evaluated, this report has been prepared to specifically address issues concerning business objectives for the project, and outline a market development plan for meeting those objectives.

  17. River Detection in Remotely Sensed Imagery Using Gabor Filtering and Path Opening

    Directory of Open Access Journals (Sweden)

    Kang Yang

    2015-07-01

    Full Text Available Detecting rivers from remotely sensed imagery is an initial yet important step in space-based river studies. This paper proposes an automatic approach to enhance and detect complete river networks. The main contribution of this work is the characterization of rivers according to their Gaussian-like cross-sections and longitudinal continuity. A Gabor filter was first employed to enhance river cross-sections. Rivers are better discerned from the image background after filtering but they can be easily corrupted owing to significant gray variations along river courses. Path opening, a flexible morphological operator, was then used to lengthen the river channel continuity and suppress noise. Rivers were consistently discerned from the image background after these two-step processes. Finally, a global threshold was automatically determined and applied to create binary river masks. River networks of the Yukon Basin and the Greenland Ice Sheet were successfully detected in two Landsat 8 OLI panchromatic images using the proposed method, yielding a high accuracy (~97.79%, a high true positive rate (~94.33%, and a low false positive rate (~1.76%. Furthermore, experimental tests validated the high capability of the proposed method to preserve river network continuity.

  18. Large summertime influenza A outbreak among tourists in Alaska and the Yukon Territory.

    Science.gov (United States)

    Uyeki, Timothy M; Zane, Suzanne B; Bodnar, Ulana R; Fielding, Katherine L; Buxton, Jane A; Miller, Joy M; Beller, Michael; Butler, Jay C; Fukuda, Keiji; Maloney, Susan A; Cetron, Martin S

    2003-05-01

    We investigated a large summertime outbreak of acute respiratory illness during May-September 1998 in Alaska and the Yukon Territory, Canada. Surveillance for acute respiratory illness (ARI), influenza-like illness (ILI), and pneumonia conducted at 31 hospital, clinic, and cruise ship infirmary sites identified 5361 cases of ARI (including 2864 cases of ILI [53%] and 171 cases of pneumonia [3.2%]) occurring primarily in tourists and tourism workers (from 18 and 37 countries, respectively). Influenza A viruses were isolated from 41 of 210 patients with ILI at 8 of 14 land sites and 8 of 17 cruise ship infirmaries. Twenty-two influenza isolates were antigenically characterized, and all were influenza A/Sydney/05/97-like (H3N2) viruses. No other predominant pathogens were identified. We estimated that >33,000 cases of ARI might have occurred during this protracted outbreak, which was attributed primarily to influenza A/Sydney/05/97-like (H3N2) viruses. Modern travel patterns may facilitate similar outbreaks, indicating the need for increased awareness about influenza by health care providers and travelers and the desirability of year-round influenza surveillance in some regions.

  19. Single nucleotide polymorphisms unravel hierarchical divergence and signatures of selection among Alaskan sockeye salmon (Oncorhynchus nerka populations

    Directory of Open Access Journals (Sweden)

    Habicht Christopher

    2011-02-01

    Full Text Available Abstract Background Disentangling the roles of geography and ecology driving population divergence and distinguishing adaptive from neutral evolution at the molecular level have been common goals among evolutionary and conservation biologists. Using single nucleotide polymorphism (SNP multilocus genotypes for 31 sockeye salmon (Oncorhynchus nerka populations from the Kvichak River, Alaska, we assessed the relative roles of geography (discrete boundaries or continuous distance and ecology (spawning habitat and timing driving genetic divergence in this species at varying spatial scales within the drainage. We also evaluated two outlier detection methods to characterize candidate SNPs responding to environmental selection, emphasizing which mechanism(s may maintain the genetic variation of outlier loci. Results For the entire drainage, Mantel tests suggested a greater role of geographic distance on population divergence than differences in spawn timing when each variable was correlated with pairwise genetic distances. Clustering and hierarchical analyses of molecular variance indicated that the largest genetic differentiation occurred between populations from distinct lakes or subdrainages. Within one population-rich lake, however, Mantel tests suggested a greater role of spawn timing than geographic distance on population divergence when each variable was correlated with pairwise genetic distances. Variable spawn timing among populations was linked to specific spawning habitats as revealed by principal coordinate analyses. We additionally identified two outlier SNPs located in the major histocompatibility complex (MHC class II that appeared robust to violations of demographic assumptions from an initial pool of eight candidates for selection. Conclusions First, our results suggest that geography and ecology have influenced genetic divergence between Alaskan sockeye salmon populations in a hierarchical manner depending on the spatial scale. Second

  20. Post-Triassic para-autochthoneity of the Yukon-Tanana Terrane: paleomagnetism of the Early Cretaceous Quiet Lake batholith

    Science.gov (United States)

    Symons, D. T. A.; McCausland, P. J. A.; Kawasaki, K.; Hart, C. J. R.

    2015-10-01

    Was the Yukon-Tanana Terrane (YTT), a California-sized part of south-central Yukon, an autochthonous or para-autochthonous part of northern British Columbia in the Early Cretaceous or was it part of a proposed allochthonous `Baja B.C.' continent offshore of southern California? To answer this fundamental question, a paleomagnetic study has been completed on 347 specimens from 24 sites in the 114.7 ± 1.1 Ma Quiet Lake batholith. This 1300 km2 pluton is composed mostly of massive medium-to-coarse grained biotite quartz monzonite that exhibits no evidence of either deformation or metamorphism, and that intrudes metamorphosed pre-Cretaceous basement rocks of the YTT in southern Yukon. The paleomagnetic analysis utilized thermal and alternating field step demagnetization, and saturation isothermal remanence methods. A well-defined characteristic remanent magnetization (ChRM) direction was isolated throughout the 500-585 °C temperature range at Decl. = 340.6°, Incl. = 77.4° (N = 14 sites, k = 51.2, A95 = 5.6°). The ChRM resides in magnetite with a low titanium content and is interpreted to be a primary thermoremanent magnetization. After correction for 490 km of geologically demonstrable dextral displacement on the inboard Tintina fault zone, the Quiet Lake batholith's paleopole is not significantly different at 95 per cent confidence from the co-eval 115 Ma reference paleopole for North America, giving non-significant translation and rotation estimates of 1.4° ± 5.1° (1σ) northwestwards and 10° ± 13° (1σ) clockwise, respectively. Thus, this is the first Early Cretaceous paleopole to show clearly that the YTT in Yukon is a para-autochthon that was part of North America's continental margin at that time. Further, after correction for Tintina fault displacement, the eight available Mesozoic YTT paleopoles agree closely with the North American apparent polar wander path (APWP). In contrast, the 22 paleopoles from the Intermontane Belt show the expected

  1. Energy intensive industry for Alaska. Volume I: Alaskan cost factors; market factors; survey of energy-intensive industries

    Energy Technology Data Exchange (ETDEWEB)

    Swift, W.H.; Clement, M.; Baker, E.G.; Elliot, D.C.; Jacobsen, J.J.; Powers, T.B.; Rohrmann, C.A.; Schiefelbein, G.L.

    1978-09-01

    The Alaskan and product market factors influencing industry locations in the state are discussed and a survey of the most energy intensive industries was made. Factors external to Alaska that would influence development and the cost of energy and labor in Alaska are analyzed. Industries that are likely to be drawn to Alaska because of its energy resources are analyzed in terms of: the cost of using Alaska energy resources in Alaska as opposed to the Lower 48; skill-adjusted wage and salary differentials between relevant Alaskan areas and the Lower 48; and basic plant and equipment and other operating cost differentials between relevant Alaskan areas and the Lower 48. Screening and evaluation of the aluminum metal industry, cement industry, chlor-alkali industry, lime industry, production of methanol from coal, petroleum refining, and production of petrochemicals and agrichemicals from North Slope natural gas for development are made.

  2. Population ecology of two woodland caribou herds in the southern Yukon

    Directory of Open Access Journals (Sweden)

    Richard Farnell

    1996-01-01

    Full Text Available Since the mid 1980's, the Aishihik herd of woodland caribou (Rangifer tarandus caribou declined from approximately 1500 to 583 animals. During the same period a nearby herd, the Wolf Lake Herd increased from approximately 664 to 1249 animals. This paper compares aspects of the ecology of these two herds to determine how these relationships conform to a general model of caribou population ecology described by Seip (1992. Comparisons include caribou demographic characteristics and distribution patterns, predator densities, abundance of alternate prey, human hunting and snow depth on caribou winter range. Ecological differences between herds were apparent in the ratio of prime bulls to cows, the abundance of moose (Alces alces, the occurrence of coyotes (Canis latrans, late winter snow conditions, and access to hunting. We hypothesize that the Wolf Lake herd was able to grow because wolves {Canis lupus preyed mainly on the relatively abundant moose population. A highly clumped winter caribou distribution may have further reduced the impact of wolf predation on the Wolf Lake herd. In contrast, the decline of the Aishihik herd was accompanied by a relative scarcity of moose, few prime aged caribou bulls probably due to a more liberal trophy harvest, and wider late-winter dispersion that offered wolves greater access to caribou. The decline may have been exaggerated by the peak in the snowshoe hare (Lepus americanus cycle which may have temporarily improved wolf pup survival. We suspect that moose are normally the primary prey of wolves in the Yukon and that a decline in moose eventually results in their being too scarce to offer an economical prey choice, prompting a prey switch to caribou. Results of our analyses conform incompletely to Seip's (1992 model for woodland caribou population ecology, particularly because the Wolf Lake herd prospered where moose were relatively abundant.

  3. The role of Indigenous knowledge in environmental health risk management in Yukon, Canada

    Directory of Open Access Journals (Sweden)

    Katelyn A. Friendship

    2012-07-01

    Full Text Available Objectives. This project aimed to gain better understandings of northern Indigenous risk perception related to food safety and to identify the role that Indigenous knowledge (IK plays in risk management processes to support more effective and culturally relevant benefit-risk (B-R management strategies. Study design. The project used an exploratory qualitative case study design to investigate the role and place of IK in the management of environmental contaminants exposure via consumption of traditional foods in Yukon First Nations (YFNs. Methods. Forty-one semi-directive interviews with Traditional Food Knowledge Holders and Health and Environment Decision-makers were conducted. A review and analysis of organizational documents related to past risk management events for the issue was conducted. Thematic content analysis was used to analyze transcripts and documents for key themes related to the research question. Results. There was a recognized need by all participants for better collaboration between scientists and YFN communities. YFNs have been involved in identifying and defining community concerns about past risk issues, setting a local context, and participating in communications strategies. Interviewees stressed the need to commit adequate time for building relationships, physically being in the community, and facilitating open communication. Conducting community-based projects was identified as critical for collaboration and for cooperative learning and management of these issues. Conclusions. The perception of “effective” benefit-risk management is significantly influenced by the efforts made to include local communities in the process. A set of common guiding principles within a process that brings together people and knowledge systems may provide a more effective way forward in cross-cultural, multiple knowledge system contexts for complex benefit-risk issues than a prescriptive rigid framework.

  4. Modern carbonate microbialites from an asbestos open pit pond, Yukon, Canada.

    Science.gov (United States)

    Power, I M; Wilson, S A; Dipple, G M; Southam, G

    2011-03-01

    Microbialites were discovered in an open pit pond at an abandoned asbestos mine near Clinton Creek, Yukon, Canada. These microbialites are extremely young and presumably began forming soon after the mine closed in 1978. Detailed characterization of the periphyton and microbialites using light and scanning electron microscopy was coupled with mineralogical and isotopic analyses to investigate the mechanisms by which these microbialites formed. The microbialites are columnar in form (cm scale), have an internal spherulitic fabric (mm scale), and are mostly made of aragonite, which is supersaturated in the subsaline pond water. Initial precipitation is seen as acicular aragonite crystals nucleating onto microbial biomass and detrital particles. Continued precipitation entombs benthic diatoms (e.g. Brachysira vitrea), filamentous algae (e.g. Oedogonium sp.), dinoflagellates, and cyanobacteria. The presence of phototrophs at spherulite centers strongly suggests that these microbes play an important initial role in aragonite precipitation. Substantial growth of individual spherulites occurs abiotically through periodic precipitation of aragonite that forms concentric laminations around spherulite centers while pauses in spherulite growth allow for colonization by microbes. Aragonite associated with biomass (δ(13)C = -4.6‰ VPDB) showed a (13)C-enrichment of 0.8‰ relative to aragonite exhibiting no biomass (δ(13)C = -5.4‰ VPDB), which suggests a modest removal of isotopically light dissolved inorganic carbon by phototrophs. The combination of a low sedimentation rate, high calcification rate, and low microbial growth rate appears to result in the formation of these microbialites. The formation of microbialites at an historic mine site demonstrates that an anthropogenically constructed environment can foster microbial carbonate formation.

  5. Nearshore Thermal Habitat and General Circulation Mapping in Arctic Alaskan Coasts Using Archived AVHRR Images

    Science.gov (United States)

    Prakash, A.; Engle, K.; Panda, S.; Margraf, J. F.; Underwood, T.

    2008-12-01

    At the University of Alaska Fairbanks a continuous archive of images from the Advanced Very High Resolution Radiometer (AVHRR) onboard the series of NOAA satellites is now available starting from 1993 through 2008 for large parts of the circum Arctic north. The largest temporal coverage available is for the Alaskan Arctic coasts and includes over 40000 images for the summer months. The broader objective of our study is to use this wealth of available data for mapping general sea surface temperatures and monitoring trends in changes in the sea surface temperatures in the last 15 years in the Alaskan Arctic Coastal regions. A second objective of our study is to look at near shore circulation patterns, and investigate how changes in the landcover of the adjacent lands affect the nearshore circulation patterns. This information is fundamentally important to understand and predict the dynamics of the shallow coastal habitats that in turn influence the distribution and condition of the fish populations. From the AVHRR archive we extracted all images from the months of July, August and September that covered at least 60 percent of the Arctic Alaskan coastal areas. The images that were in sensor projection were converted to map projection using the coastal boundary vector layer as a guideline for manually selecting tie points to correct for the geometry. Starting from the oldest images in our archive from 1993 we processed over 2000 AVHRR scenes which were then used to generate sea surface temperature images and NDVI images and a time series animation of changing patterns of NDVI. The prototype animation generated to demonstrate the landcover and coastal region dynamics will be further extended to cover the entire time span from 1993 through 2008.

  6. NifH- Harboring Bacterial Community Composition Across an Alaskan Permafrost Thaw Gradient

    OpenAIRE

    Christopher Ryan Penton; Caiyun Yang; Liyou Wu; Qiong Wang; Jin Zhang; Feifei Liu; Yujia Qin; Ye Deng; Hemme, Christopher L.; Tianling Zheng; Edward A.G. Schuur; James M. Tiedje; Jizhong Zhou

    2016-01-01

    Since nitrogen (N) is often limiting in permafrost soils, we investigated the N2-fixing genetic potential and the inferred taxa harboring those genes by sequencing nifH gene fragments in samples taken along a permafrost thaw gradient in an Alaskan boreal soil. Samples from minimally, moderately and extensively thawed sites were taken to a depth of 79 cm to encompass zones above and below the depth of the water table. NifH reads were translated with frameshift correction and 112,476 sequences ...

  7. A promising tool for subsurface permafrost mapping-An application of airborne geophysics from the Yukon River Basin, Alaska

    Science.gov (United States)

    Abraham, Jared

    2011-01-01

    Permafrost is a predominant physical feature of the Earth's Arctic and Subarctic clines and a major consideration encompassing ecosystem structure to infrastructure engineering and placement. Perennially frozen ground is estimated to cover about 85 percent of the state of Alaska where northern reaches are underlain with continuous permafrost and parts of interior Alaska are underlain by areas of discontinuous and (or) sporadic permafrost (fig. 1). The region of Interior Alaska, where permafrost is scattered among unfrozen ground, is a complex mosaic of terrains and habitats. Such diversity creates arrays of lakes and surface-water and groundwater patterns that continental populations of migratory waterfowl and internationally significant fisheries have adapted to over time. A road or pipeline might pass over frozen and unfrozen ground, affecting the types of materials and engineering approaches needed to sustain the infrastructure.

  8. Effects of storm surge erosion on waterfowl habitats at the Kashunuk River, Yukon-Kuskokwim Delta, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Erosion, accelerated by storm surges, resulted in a 0.11 loss of vegetation and an alteration of species composition within coastal fringe plant communities of the...

  9. Geomorphology of the lower Copper River, Alaska

    Science.gov (United States)

    Brabets, Timothy P.

    1997-01-01

    The Copper River, located in southcentral Alaska, drains an area of more than 24,000 square miles. About 30 miles above its mouth, this large river enters Miles Lake, a proglacial lake formed by the retreat of Miles Glacier. Downstream from the outlet of Miles Lake, the Copper River flows past the face of Childs Glacier before it enters a large, broad, alluvial flood plain. The Copper River Highway traverses this flood plain and in 1995, 11 bridges were located along this section of the highway. These bridges cross parts of the Copper River and in recent years, some of these bridges have sustained serious damage due to the changing course of the Copper River. Although the annual mean discharge of the lower Copper River is 57,400 cubic feet per second, most of the flow occurs during the summer months from snowmelt, rainfall, and glacial melt. Approximately every six years, an outburst flood from Van Cleve Lake, a glacier-dammed lake formed by Miles Glacier, releases approximately 1 million acre-feet of water into the Copper River. When the outflow rate from Van Cleve Lake reaches it peak, the flow of the Copper River will increase between 150,000 to 190,000 cubic feet per second. Data collected by bedload sampling and continuous seismic reflection indicated that Miles Lake traps virtually all the bedload being transported by the Copper River as it enters the lake from the north. The reservoir-like effect of Miles Lake results in the armoring of the channel of the Copper River downstream from Miles Lake, past Childs Glacier, until it reaches the alluvial flood plain. At this point, bedload transport begins again. The lower Copper River transports 69 million tons per year of suspended sediment, approximately the same quantity as the Yukon River, which drains an area of more than 300,000 square miles. By correlating concurrent flows from a long-term streamflow-gaging station on the Copper River with a short-term streamflow-gaging station at the outlet of Miles Lake

  10. Characterizing the role of hydrological processes on lake water balances in the Old Crow Flats, Yukon Territory, Canada, using water isotope tracers

    Science.gov (United States)

    Turner, Kevin W.; Wolfe, Brent B.; Edwards, Thomas W. D.

    2010-05-01

    SummaryWe employ water isotope tracers to assess hydrological processes controlling lake water balances in the Old Crow Flats (OCF) landscape, northern Yukon Territory, Canada. Fifty-six lakes were sampled in June and July 2007 and 26 of these were re-sampled in September 2007. Based on patterns of isotopic evolution in δ18O- δ2H space, calculations of input water compositions ( δI) and evaporation-to-inflow ( E/ I) ratios, and field observations we identify snowmelt-dominated, rainfall-dominated, groundwater-influenced, evaporation-dominated and drained lake types, which represent the dominant hydrological process influencing the lake water balance. These results highlight the diversity in lake water balance conditions in the OCF, which are strongly associated with landscape characteristics. Snowmelt-dominated lakes are located where more dense vegetation cover entraps snow transported by prevailing northeasterly winds. Rainfall-dominated lakes occupy areas of sparse tundra vegetation cover where less snow accumulates. Groundwater-influenced oxbow lakes are located along the floodplain of higher-order river and creek channels and receive input throughout the ice-free season from snowmelt-recharged channel fens and sub-surface flow. Only one basin became evaporation-dominated during the 2007 open-water season probably because extremely high precipitation during the preceding late summer, late winter and early spring offset vapour loss. However, rainfall-dominated lakes appear to be more susceptible to evaporative drawdown than snowmelt-dominated and groundwater-influenced lakes, and many would likely evolve to evaporation-dominated during drier summers. Drained lakes are commonly observed throughout the landscape and in most cases likely result from elevated water levels and channel erosion between waterbodies. Unusually high amounts of snowmelt and/or rainfall triggered the drainage of two lakes in early June 2007 in which overflow led to rapid erosion of

  11. Fine-scale population genetic structure in Alaskan Pacific halibut (Hippoglossus stenolepis)

    Science.gov (United States)

    2010-01-01

    Pacific halibut collected in the Aleutian Islands, Bering Sea and Gulf of Alaska were used to test the hypothesis of genetic panmixia for this species in Alaskan marine waters. Nine microsatellite loci and sequence data from the mitochondrial (mtDNA) control region were analyzed. Eighteen unique mtDNA haplotypes were found with no evidence of geographic population structure. Using nine microsatellite loci, significant heterogeneity was detected between Aleutian Island Pacific halibut and fish from the other two regions (FST range = 0.007–0.008). Significant FST values represent the first genetic evidence of divergent groups of halibut in the central and western Aleutian Archipelago. No significant genetic differences were found between Pacific halibut in the Gulf of Alaska and the Bering Sea leading to questions about factors contributing to separation of Aleutian halibut. Previous studies have reported Aleutian oceanographic conditions at deep inter-island passes leading to ecological discontinuity and unique community structure east and west of Aleutian passes. Aleutian Pacific halibut genetic structure may result from oceanographic transport mechanisms acting as partial barriers to gene flow with fish from other Alaskan waters.

  12. Parallel genetic basis for repeated evolution of armor loss in Alaskan threespine stickleback populations.

    Science.gov (United States)

    Cresko, William A; Amores, Angel; Wilson, Catherine; Murphy, Joy; Currey, Mark; Phillips, Patrick; Bell, Michael A; Kimmel, Charles B; Postlethwait, John H

    2004-04-20

    Most adaptation is thought to occur through the fixation of numerous alleles at many different loci. Consequently, the independent evolution of similar phenotypes is predicted to occur through different genetic mechanisms. The genetic basis of adaptation is still largely unknown, however, and it is unclear whether adaptation to new environments utilizes ubiquitous small-effect polygenic variation or large-effect alleles at a small number of loci. To address this question, we examined the genetic basis of bony armor loss in three freshwater populations of Alaskan threespine stickleback, Gasterosteus aculeatus, that evolved from fully armored anadromous populations in the last 14,000 years. Crosses between complete-armor and low-armor populations revealed that a single Mendelian factor governed the formation of all but the most anterior lateral plates, and another independently segregating factor largely determined pelvic armor. Genetic mapping localized the Mendelian genes to different chromosomal regions, and crosses among these same three widely separated populations showed that both bony plates and pelvic armor failed to fully complement, implicating the same Mendelian armor reduction genes. Thus, rapid and repeated armor loss in Alaskan stickleback populations appears to be occurring through the fixation of large-effect variants in the same genes.

  13. Using smooth sheets to describe groundfish habitat in Alaskan waters, with specific application to two flatfishes

    Science.gov (United States)

    Zimmermann, Mark; Reid, Jane A.; Golden, Nadine

    2016-10-01

    In this analysis we demonstrate how preferred fish habitat can be predicted and mapped for juveniles of two Alaskan groundfish species - Pacific halibut (Hippoglossus stenolepis) and flathead sole (Hippoglossoides elassodon) - at five sites (Kiliuda Bay, Izhut Bay, Port Dick, Aialik Bay, and the Barren Islands) in the central Gulf of Alaska. The method involves using geographic information system (GIS) software to extract appropriate information from National Ocean Service (NOS) smooth sheets that are available from NGDC (the National Geophysical Data Center). These smooth sheets are highly detailed charts that include more soundings, substrates, shoreline and feature information than the more commonly-known navigational charts. By bringing the information from smooth sheets into a GIS, a variety of surfaces, such as depth, slope, rugosity and mean grain size were interpolated into raster surfaces. Other measurements such as site openness, shoreline length, proportion of bay that is near shore, areas of rocky reefs and kelp beds, water volumes, surface areas and vertical cross-sections were also made in order to quantify differences between the study sites. Proper GIS processing also allows linking the smooth sheets to other data sets, such as orthographic satellite photographs, topographic maps and precipitation estimates from which watersheds and runoff can be derived. This same methodology can be applied to larger areas, taking advantage of these free data sets to describe predicted groundfish essential fish habitat (EFH) in Alaskan waters.

  14. Social Disruption and Psychological Stress in an Alaskan Fishing Community: The Impact of the Exxon Valdez Oil Spill.

    Science.gov (United States)

    Picou, J. Steven; And Others

    Technological accidents such as the Exxon Valdez oil spill in 1989 create man-made disaster situations that threaten community survival and the well-being and quality of life of community residents. This paper focuses on the social and psychological impact of the 1989 oil spill on Cordova, an isolated Alaskan community with high economic…

  15. Geology and origin of epigenetic lode gold deposits, Tintina Gold Province, Alaska and Yukon: Chapter A in Recent U.S. Geological Survey studies in the Tintina Gold Province, Alaska, United States, and Yukon, Canada--results of a 5-year project

    Science.gov (United States)

    Goldfarb, Richard J.; Marsh, Erin E.; Hart, Craig J.R.; Mair, John L.; Miller, Marti L.; Johnson, Craig; Gough, Larry P.; Day, Warren C.

    2007-01-01

    More than 50 million ounces of lode gold resources have been defined in the previous 15 years throughout accreted terranes of interior Alaska and in adjacent continental margin rocks of Yukon. The major deposits in this so-called Tintina Gold Province formed around 105 to 90 million years ago in east-central Alaska and Yukon, and around 70 million years ago in southwestern Alaska, late in the deformational history of their host rocks. All gold deposits studied to date formed from CO2

  16. Holocene ice-wedge polygon development in northern Yukon permafrost peatlands (Canada)

    Science.gov (United States)

    Fritz, Michael; Wolter, Juliane; Rudaya, Natalia; Palagushkina, Olga; Nazarova, Larisa; Obu, Jaroslav; Rethemeyer, Janet; Lantuit, Hugues; Wetterich, Sebastian

    2016-09-01

    Ice-wedge polygon (IWP) peatlands in the Arctic and Subarctic are extremely vulnerable to climatic and environmental change. We present the results of a multidisciplinary paleoenvironmental study on IWPs in the northern Yukon, Canada. High-resolution laboratory analyses were carried out on a permafrost core and the overlying seasonally thawed (active) layer, from an IWP located in a drained lake basin on Herschel Island. In relation to 14 Accelerator Mass Spectrometry (AMS) radiocarbon dates spanning the last 5000 years, we report sedimentary data including grain size distribution and biogeochemical parameters (organic carbon, nitrogen, C/N ratio, δ13C), stable water isotopes (δ18O, δD), as well as fossil pollen, plant macrofossil and diatom assemblages. Three sediment units (SUs) correspond to the main stages of deposition (1) in a thermokarst lake (SU1: 4950 to 3950 cal yrs BP), (2) during transition from lacustrine to palustrine conditions after lake drainage (SU2: 3950 to 3120 cal yrs BP), and (3) in palustrine conditions of the IWP field that developed after drainage (SU3: 3120 cal yrs BP to 2012 CE). The lacustrine phase (pre 3950 cal yrs BP) is characterized by planktonic-benthic and pioneer diatom species indicating circumneutral waters, and very few plant macrofossils. The pollen record has captured a regional signal of relatively stable vegetation composition and climate for the lacustrine stage of the record until 3950 cal yrs BP. Palustrine conditions with benthic and acidophilic diatom species characterize the peaty shallow-water environments of the low-centered IWP. The transition from lacustrine to palustrine conditions was accompanied by acidification and rapid revegetation of the lake bottom within about 100 years. Since the palustrine phase we consider the pollen record as a local vegetation proxy dominated by the plant communities growing in the IWP. Ice-wedge cracking in water-saturated sediments started immediately after lake drainage at

  17. Seismological Detection and Analysis of Recent Landslides in Alaska and the Yukon

    Science.gov (United States)

    Ekström, G.; Hansen, R. A.; Pavlis, G. L.; Lipovsky, P.

    2007-12-01

    Large landslides and avalanches generate seismic waves that can be used to detect, locate, and constrain the dynamic processes active in the slides. We have detected and located several landslide events using the Global Seismographic Network (GSN) as a long-period array. The detected events have equivalent long-period magnitudes of about M=5, while local magnitudes for these events, where available, are 2--3 magnitude units smaller. Two of the largest detected landslides are the 2005 Mount Steller (M=5.2) and the 2007 Mount Steele (M=5.2) events, located in the Pacific Coast Range in southern Alaska and the southern Yukon, respectively. In contrast to the forces active in standard earthquakes, in which seismic waves are generated as a consequence of tectonic stress drop within the Earth, landslides excite seismic waves through the time-varying forces caused by the acceleration and deceleration of a sliding mass interacting with the Earth's surface. Both the Mount Steller and the Mount Steele events involved sliding volumes of tens of millions of cubic meters of debris, vertical drops of around 2000 meters and runouts of more than 5 km. We use seismograms from several local and regional seismometers, including records from the STEEP PASSCAL array at epicentral distances as short as 10 km, to model the sliding process. We parameterize the source as a point force acting on the Earth's surface and obtain its magnitude, strike, and dip as a function of time. We observe the initial, nearly vertical, unloading force as the rock detaches from the solid Earth, a downward impulse as the mass is diverted into a horizontal trajectory at the base of the steep mountain slope, and the horizontal force corresponding to the deceleration phase as friction brings the sliding mass to a halt. Both slides have total durations of approximately 100 seconds. We find good agreement between the force histories inferred from seismograms and simple forward calculations of the dynamics of the

  18. Report to Pacific Flyway Study Committee and Waterfowl Conservation Committee on the 1985-1996 breeding ground surveys of geese, swans and sandhill cranes in the coastal zone, Yukon-Kuskokwim delta, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Aerial surveys of nesting geese, swans and sandhill cranes were conducted in the coastal zone of the Yukon-Kuskokwim Delta for the 12th consecutive year. The survey...

  19. Report to Pacific Flyway Study Committee and Waterfowl Conservation Committee on the 1985-1993 breeding ground surveys of geese and swans in the coastal zone, Yukon-Kuskokwim Delta, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Aerial surveys of geese nesting in the coastal zone of the Yukon Kuskokwim Delta were conducted for the ninth consecutive year. The population response of emperor...

  20. Report to Pacific Flyway Study Committee and Waterfowl Conservation Committee on the 1985-1991 breeding ground surveys of geese and swans in the coastal zone, Yukon-Kuskokwim Delta, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Aerial surveys of geese nesting in the coastal zone of the Yukon Kuskokwim Delta were conducted for the seventh consecutive year. The survey was flown from 6 June13...

  1. Report to the Pacific Flyway Study Committee and Waterfowl Conservation Committee on the 1985-2000 breeding ground survyes of geese, swans and sandhill cranes in the coastal zone of the Yukon-Kuskokwim Delta, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Aerial surveys of geese, tundra swans, and sandhill cranes were conducted in the coastal zone of the Yukon-Kuskokwim Delta for the 16th consecutive year. The survey...

  2. Report to Pacific Flyway Study Committee and Waterfowl Conservation Committee on the 1985-1992 breeding ground surveys of geese and swans in the coastal zone, Yukon-Kuskokwim delta, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Aerial surveys of geese nesting in the coastal zone of the Yukon-Kuskokwim Delta were conducted for the eighth consecutive year. The survey was flown from 11 - 19...

  3. Report to Pacific Flyway Study Committee and Waterfowl Conservation Committee on the 1985-1994 breeding ground surveys of geese and swans in the coastal zone, Yukon-Kuskokwim delta, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Aerial surveys of geese nesting in the coastal zone of the Yukon Kuskokwim Delta were conducted for the tenth consecutive year. The survey was flown from 2 - 10...

  4. Report to the Pacific Flyway Study Committee and Waterfowl Conservation Committee on the 1985-1999 breeding ground survyes of geese, swans and sandhill cranes in the coastal zone of the Yukon-Kuskokwim Delta, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Aerial surveys of nesting geese, tundra swans, and sandhill cranes were conducted in the coastal zone of the Yukon-Kuskokwim Delta for the 15th consecutive year. The...

  5. Report to Pacific Flyway Study Committee and Waterfowl Conservation Committee on the 1985-1995 breeding ground surveys of geese and swans in the coastal zone, Yukon-Kuskokwim Delta, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Aerial surveys of nesting geese, swans and sandhill cranes in the coastal zone of the Yukon-Kuskokwim Delta were conducted for the eleventh consecutive year. The...

  6. Genetics, recruitment, and migration patterns of Arctic Cisco (Coregonus autumnalis) in the Colville River, Alaska and Mackenzie River, Canada

    Science.gov (United States)

    Zimmerman, Christian E.; Ramey, Andy M.; Turner, S.; Mueter, Franz J.; Murphy, S.; Nielsen, Jennifer L.

    2013-01-01

    Arctic cisco Coregonus autumnalis have a complex anadromous life history, many aspects of which remain poorly understood. Some life history traits of Arctic cisco from the Colville River, Alaska, and Mackenzie River basin, Canada, were investigated using molecular genetics, harvest data, and otolith microchemistry. The Mackenzie hypothesis, which suggests that Arctic cisco found in Alaskan waters originate from the Mackenzie River system, was tested using 11 microsatellite loci and a single mitochondrial DNA gene. No genetic differentiation was found among sample collections from the Colville River and the Mackenzie River system using molecular markers (P > 0.19 in all comparisons). Model-based clustering methods also supported genetic admixture between sample collections from the Colville River and Mackenzie River basin. A reanalysis of recruitment patterns to Alaska, which included data from recent warm periods and suspected changes in atmospheric circulation patterns, still finds that recruitment is correlated to wind conditions. Otolith microchemistry (Sr/Ca ratios) confirmed repeated, annual movements of Arctic cisco between low-salinity habitats in winter and marine waters in summer.

  7. River engineering

    NARCIS (Netherlands)

    De Vries, M.

    1993-01-01

    One dimension models - basic eauations, analytical models, numberical models. One dimensional models -suspended load, roughness and resistance of river beds. Solving river problems - tools, flood mitigation, bank protection.

  8. Rethinking ``Yellowstone in Yukon'' and Baja British Columbia: Paleomagnetism of the Late Cretaceous Swede Dome stock, northern Canadian Cordillera

    Science.gov (United States)

    McCausland, P. J. A.; Symons, D. T. A.; Hart, C. J. R.

    2005-12-01

    Paleomagnetic results obtained from the 69.8 Ma Swede Dome stock, emplaced into the pericratonic Yukon Tanana Terrane (YTT) west of Dawson, Yukon, indicate a minimal northward translation of 360 ± 575 km and a clockwise rotation of 20° ± 23° with respect to North America, in accord with the displacement of 425 km along the nearby Tintina Fault. Coeval Carmacks Group volcanics in contrast have previously indicated ˜1900 km northward translation and minimal rotation and have been proposed to be a displaced manifestation of the fixed Yellowstone hot spot, thus providing an independent estimate of the Late Cretaceous paleoposition of the "Baja British Columbia" terranes of western North America. A compilation of recent mid and Late Cretaceous paleomagnetic results from the YTT and Intermontane Belt (IMB) terranes reveals that the Carmacks Group paleomagnetic result is anomalous. The YTT and IMB terranes, which form the bulk of Baja British Columbia, appear instead to have experienced <1000 km northward translation with respect to North America since 70 Ma, consistent with geological estimates of motion along plausible accommodating faults. In addition, past mobility of the Hawaii-Emperor hot spot implies that the Pacific hot spots may have experienced ˜1200 km of southward motion from 81 to 47 Ma. If so, then the paleoposition of the Yellowstone hot spot if it existed at 70 Ma would likely have produced the Carmacks magmatism ˜1000 km north of Yellowstone's current latitude, consistent with a "moderate" (<1000 km) post-70 Ma northward translation of the YTT and IMB terranes to their present position in North America.

  9. Using local knowledge, hydrological, and climate data to develop a driftwood harvest model in interior Alaska

    Science.gov (United States)

    Jones, C.; Hinzman, L. D.; Kielland, K.

    2011-12-01

    Residents of rural Alaska usually harvest driftwood from the Yukon River during two distinct periods in the summer. Typically, driftwood accompanies high flows on the Yukon River associated with spring break-up. A few weeks later, a second pulse of driftwood associated with the "2nd Rise" typically flows during early June. This study examines the nature of the differential timing of high flow events in the Yukon River to develop a model of the driftwood harvest. Many communities in interior Alaska have grown to rely upon driftwood as an important source of wood, which is used in construction and as a source of fuel. Increasingly, villages in rural Alaska are trying to lessen their dependence upon high-cost fossil fuels and other non-renewable energy sources. A number of Alaskan villages have recently installed wood chip-fired boilers to generate heat and/or electricity and additional boilers are slated to be installed in rural Alaska in the near future. These boilers are largely fed by driftwood which can be harvested cheaply and processed easily. But if the driftwood harvest is dependent upon high flows in the Yukon, how will fluctuations in river hydrology affect the efficacy and reliability of driftwood harvest? We examined this question using information from local knowledge in conjunction with U.S. census, hydrological, and climate reanalysis data sets to model the magnitude of Yukon River driftwood harvest during summer. It appears that since 1995, high flow events have decreased magnitude, but increased in frequency, compared to the period between 1977 and 1994. Based upon this observation, the annual potential driftwood harvest in Tanana since 1995 was modeled to be greater compared to the average prior to 1994. This pattern was largely driven by a change in the frequency and duration of high flow events. Thus, the availability of driftwood as an energy resource is expected to be commensurate to the recurrence of high flow events on the Yukon River.

  10. Identification of a haptoglobin-hemoglobin complex in the Alaskan Least Cisco (Coregonus sardinella).

    Science.gov (United States)

    Wahl, S M; Boger, J K; Michael, V; Duffy, L K

    1992-01-01

    The hemoglobin and a hemoglobin binding protein have been characterized in the Arctic fish (Coregonus sardinella). The evolutionary significance of the hemoglobin and plasma protein differences between fish and mammals is still unresolved. Blood samples from the Alaskan Least Cisco were separated into plasma and hemoglobin fractions and the proteins in these fractions were analyzed both by alkaline agarose gel electrophoresis, by isolelectric focusing, and by capillary electrophoresis. Staining the plasma proteins gels with o-dianisidine revealed hemoglobin containing protein complexes. A hemoglobin-containing band was observed in hemolyzed plasma which did not migrate with free hemoglobin, and is believed to be hemoglobin-haptoglobin complex. Size exclusion chromatography further characterized the hemoglobin as disassociating freely into dimers, and hemoglobin-haptoglobin complex having a molecular weight greater then 200,000 daltons.

  11. Fisheries portfolio diversification and turnover buffer Alaskan fishing communities from abrupt resource and market changes.

    Science.gov (United States)

    Cline, Timothy J; Schindler, Daniel E; Hilborn, Ray

    2017-01-16

    Abrupt shifts in natural resources and their markets are a ubiquitous challenge to human communities. Building resilient social-ecological systems requires approaches that are robust to uncertainty and to regime shifts. Harvesting diverse portfolios of natural resources and adapting portfolios in response to change could stabilize economies reliant on natural resources and their markets, both of which are prone to unpredictable shifts. Here we use fisheries catch and revenue data from Alaskan fishing communities over 34 years to test whether diversification and turnover in the composition of fishing opportunities increased economic stability during major ocean and market regime shifts in 1989. More than 85% of communities show reduced fishing revenues following these regime shifts. However, communities with the highest portfolio diversity and those that could opportunistically shift the composition of resources they harvest, experienced negligible or even positive changes in revenue. Maintaining diversity in economic opportunities and enabling turnover facilitates sustainability of communities reliant on renewable resources facing uncertain futures.

  12. Google's Geo Education Outreach: Results and Discussion of Outreach Trip to Alaskan High Schools.

    Science.gov (United States)

    Kolb, E. J.; Bailey, J.; Bishop, A.; Cain, J.; Goddard, M.; Hurowitz, K.; Kennedy, K.; Ornduff, T.; Sfraga, M.; Wernecke, J.

    2008-12-01

    The focus of Google's Geo Education outreach efforts (http://www.google.com/educators/geo.html) is on helping primary, secondary, and post-secondary educators incorporate Google Earth and Sky, Google Maps, and SketchUp into their classroom lessons. In partnership with the University of Alaska, our Geo Education team members visited several remote Alaskan high schools during a one-week period in September. At each school, we led several 40-minute hands-on learning sessions in which Google products were used by the students to investigate local geologic and environmental processes. For the teachers, we provided several resources including follow-on lesson plans, example KML-based lessons, useful URL's, and website resources that multiple users can contribute to. This talk will highlight results of the trip and discuss how educators can access and use Google's Geo Education resources.

  13. Fisheries portfolio diversification and turnover buffer Alaskan fishing communities from abrupt resource and market changes

    Science.gov (United States)

    Cline, Timothy J.; Schindler, Daniel E.; Hilborn, Ray

    2017-01-01

    Abrupt shifts in natural resources and their markets are a ubiquitous challenge to human communities. Building resilient social-ecological systems requires approaches that are robust to uncertainty and to regime shifts. Harvesting diverse portfolios of natural resources and adapting portfolios in response to change could stabilize economies reliant on natural resources and their markets, both of which are prone to unpredictable shifts. Here we use fisheries catch and revenue data from Alaskan fishing communities over 34 years to test whether diversification and turnover in the composition of fishing opportunities increased economic stability during major ocean and market regime shifts in 1989. More than 85% of communities show reduced fishing revenues following these regime shifts. However, communities with the highest portfolio diversity and those that could opportunistically shift the composition of resources they harvest, experienced negligible or even positive changes in revenue. Maintaining diversity in economic opportunities and enabling turnover facilitates sustainability of communities reliant on renewable resources facing uncertain futures. PMID:28091534

  14. Quantifying soil carbon accumulation in Alaskan terrestrial ecosystems during the last 15 000 years

    Science.gov (United States)

    Wang, Sirui; Zhuang, Qianlai; Yu, Zicheng

    2016-11-01

    Northern high latitudes contain large amounts of soil organic carbon (SOC), of which Alaskan terrestrial ecosystems account for a substantial proportion. In this study, the SOC accumulation in Alaskan terrestrial ecosystems over the last 15 000 years was simulated using a process-based biogeochemistry model for both peatland and non-peatland ecosystems. Comparable with the previous estimates of 25-70 Pg C in peatland and 13-22 Pg C in non-peatland soils within 1 m depth in Alaska using peat-core data, our model estimated a total SOC of 36-63 Pg C at present, including 27-48 Pg C in peatland soils and 9-15 Pg C in non-peatland soils. Current vegetation stored 2.5-3.7 Pg C in Alaska, with 0.3-0.6 Pg C in peatlands and 2.2-3.1 Pg C in non-peatlands. The simulated average rate of peat C accumulation was 2.3 Tg C yr-1, with a peak value of 5.1 Tg C yr-1 during the Holocene Thermal Maximum (HTM) in the early Holocene, 4-fold higher than the average rate of 1.4 Tg C yr-1 over the rest of the Holocene. The SOC accumulation slowed down, or even ceased, during the neoglacial climate cooling after the mid-Holocene, but increased again in the 20th century. The model-estimated peat depths ranged from 1.1 to 2.7 m, similar to the field-based estimate of 2.29 m for the region. We found that the changes in vegetation and their distributions were the main factors in determining the spatial variations of SOC accumulation during different time periods. Warmer summer temperature and stronger radiation seasonality, along with higher precipitation in the HTM and the 20th century, might have resulted in the extensive peatland expansion and carbon accumulation.

  15. From Natural to Design River Deltas

    Science.gov (United States)

    Giosan, Liviu

    2016-04-01

    Productive and biologically diverse, deltaic lowlands attracted humans since prehistory and may have spurred the emergence of the first urban civilizations. Deltas continued to be an important nexus for economic development across the world and are currently home for over half a billion people. But recently, under the double whammy of sea level rise and inland sediment capture behind dams, they have become the most threatened coastal landscape. Here I will address several deceptively simple questions to sketch some unexpected answers using example deltas from across the world from the Arctic to the Tropics, from the Danube to the Indus, Mississippi to Godavari and Krishna, Mackenzie to Yukon. What is a river delta? What is natural and what is not in a river delta? Are the geological and human histories of a delta important for its current management? Is maintaining a delta the same to building a new one? Can we design better deltas than Nature? These answers help us see clearly that survival of deltas in the next century depends on human intervention and is neither assured nor simple to address or universally applicable. Empirical observations on the hydrology, geology, biology and biochemistry of deltas are significantly lagging behind modeling capabilities endangering the applicability of numerical-based reconstruction solutions and need to be ramped up significantly and rapidly across the world.

  16. Sikuliqiruq: Ice dynamics of the Meade river - Arctic Alaska, from freezeup to breakup from time-series ground imagery

    Science.gov (United States)

    Beck, R.A.; Rettig, A.J.; Ivenso, C.; Eisner, Wendy R.; Hinkel, Kenneth M.; Jones, Benjamin M.; Arp, C.D.; Grosse, G.; Whiteman, D.

    2010-01-01

    Ice formation and breakup on Arctic rivers strongly influence river flow, sedimentation, river ecology, winter travel, and subsistence fishing and hunting by Alaskan Natives. We use time-series ground imagery ofthe Meade River to examine the process at high temporal and spatial resolution. Freezeup from complete liquid cover to complete ice cover ofthe Meade River at Atqasuk, Alaska in the fall of 2008 occurred in less than three days between 28 September and 2 October 2008. Breakup in 2009 occurred in less than two hours between 23:47 UTC on 23 May 2009 and 01:27 UTC on 24 May 2009. All times in UTC. Breakup in 2009 and 2010 was ofthe thermal style in contrast to the mechanical style observed in 1966 and is consistent with a warming Arctic. ?? 2010 Taylor & Francis.

  17. Developing a Child and Youth Mental Health and Addictions Framework for Yukon as a Foundation for Policy Reform: Engaging Stakeholders Through a Policy and Research Partnership

    Directory of Open Access Journals (Sweden)

    Gillian Mulvale

    2016-09-01

    Full Text Available In April 2015 the Yukon Government released a new child and youth mental health and addictions framework (CYMHAF to improve territory-wide access to basic mental health care and coordination of services for children and families. Yukon’s limited resource base and dispersed population challenges delivery of child and youth mental health and addictions services to small rural communities where needs are often high as a legacy of residential school policies. The objective of CYMHAF is to improve outcomes by identifying and capitalizing on current strengths, and reallocating existing resources to better meet the mental health needs of Yukon youth and families. Access, coordination and quality problems associated with existing services, growing public awareness of mental health issues, and a new national policy framework designed to assist provinces and territories, led Yukon policy makers to partner with researchers to capitalize on a Canadian Institutes of Health Research (CIHR strategic grant initiative. CYMHAF was based on extensive stakeholder engagement, best evidence and advice from key informants in other jurisdictions, and offers a cascading model of service delivery through which basic mental health care can be provided by existing health and human service workers in communities. These workers will be trained in child and youth mental health competencies, and will have electronic linkages and support to integrated teams of primary care providers who will be located in regional hubs once fully implemented, and to specialists in Whitehorse and out of Territory. Implementation is underway with some training of front line Health and Social Service and First Nations workers, a new mental wellness strategy for Yukon founded on CYMHAF scheduled for release in spring 2016, and may be accelerated by federal government promises of a new Health Accord and a new relationship with indigenous people.

  18. A Two-dimensional Heat Transfer Model for Atmosphere-land System in the Lake-dominated Alaskan Arctic

    Institute of Scientific and Technical Information of China (English)

    LING Feng; ZHANG Ting-jun

    2002-01-01

    Understanding lake ice growth and its sensitivity to climate change is vital to understand the thermal regime of thaw lake systems and predict their response to climate change. In this paper, a physically-based, two-dimensional, non-steady mathematical model is developed for studying the role of shallow tundra lakes in the Alaskan Arctic. Both the radiation absorption in lake water and the phasechange in permafrost are considerd in the model. The materials the model includes are snow, ice, water, unfrozen and frozen soil (peat, silt,sand and gravel). The basic inputs to the model observed mean daily air temperature and snow depth. The ability of this model to simulate lake ice growth and thickness variation, lake water temperature distribution, the thermal regime of permafrost and talik dynamics beneath lakes, and thawing rate of permafrost below and adjacent to shallow thaw lakes offers the potential to describe the effects of climate change in the Alaskan Arctic.

  19. Microbes residing in young organic rich Alaskan soils contain older carbon than those residing in old mineral high Arctic soils

    Science.gov (United States)

    Ziolkowski, L. A.; Slater, G. F.; Onstott, T. C.; Whyte, L.; Townsend-Small, A.

    2013-12-01

    Arctic soils range from very organic rich to low carbon and mineral-dominated soils. At present, we do not yet fully understand if all carbon in the Arctic is equally vulnerable to mineralization in a warmer climate. Many studies have demonstrated that ancient carbon is respired when permafrost has thawed, yet our understanding of the active layer and permafrost carbon dynamics is still emerging. In an effort to remedy this disconnect between our knowledge of surface fluxes and below ground processes, we used radiocarbon to examine the microbial carbon dynamics in soil cores from organic rich soils near Barrow, Alaska and mineral soils from the Canadian high Arctic. Specifically, we compared the microbial community using lipid biomarkers, the inputs of carbon using n-alkanes and measured the 14C of both the bulk organic carbon and of the microbial lipids. In theory, the microbial lipids (phospholipid fatty acids, PLFA) represent the viable microbial community, as these lipids are hydrolyzed quickly after cell death. Variations in the PLFA distributions suggested that different microbial communities inhabit organic rich Alaskan soils and those of the Canadian high Arctic. When the PLFA concentrations were converted to cellular concentration, they were within the same order of magnitude (1 to 5 x 108 cells/g dry soil) with slightly higher cell concentrations in the organic rich Alaskan soils. When these cellular concentrations were normalized to the organic carbon content, the Canadian high Arctic soils contained a greater proportion of microbes. Although bulk organic carbon 14C of Alaskan soils indicated more recent carbon inputs into the soil than the Canadian high Arctic soils, the 14C of the PLFA revealed the opposite. For corresponding depth horizons, microbes in Alaskan soils were consuming carbon 1000 to 1500 years older than those in the Canadian high Arctic. Differences between the 14C content of bulk organic carbon and the microbial lipids were much smaller

  20. Isolation of a complete circular virus genome sequence from an Alaskan black-capped chickadee (Poecile atricapillus) gastrointestinal tract sample.

    Science.gov (United States)

    Hanna, Zachary R.; Runckel, Charles; Fuchs, Jerome; DeRisi, Joseph L.; Mindell, David P.; Van Hemert, Caroline R.; Handel, Colleen M.; Dumbacher, John P.

    2015-01-01

    We report here the genome sequence of a circular virus isolated from samples of an Alaskan black-capped chickadee (Poecile atricapillus) gastrointestinal tract. The genome is 2,152 bp in length and is most similar (30 to 44.5% amino acid identity) to the genome sequences of other single-stranded DNA (ssDNA) circular viruses belonging to the gemycircularvirus group.

  1. Long-term change in limnology and invertebrates in Alaskan boreal wetlands

    Science.gov (United States)

    Corcoran, R.M.; Lovvorn, J.R.; Heglund, P.J.

    2009-01-01

    Climate change is more pronounced at high northern latitudes, and may be affecting the physical, chemical, and biological attributes of the abundant wetlands in boreal forests. On the Yukon Flats, located in the boreal forest of northeast Alaska, wetlands originally sampled during 1985-1989 were re-sampled for water chemistry and macroinvertebrates in summer 2001-2003. Wetlands sampled lost on average 19% surface water area between these periods. Total nitrogen and most metal cations (Na, Mg, and Ca, but not K) increased between these periods, whereas total phosphorus and chlorophyll a (Chl a) declined. These changes were greater in wetlands that had experienced more drying (decreased surface area). Compared with 1985-1989, densities of cladocerans, copepods, and ostracods in both June and August were much higher in 2002-2003, whereas densities of amphipods, gastropods, and chironomid larvae were generally lower. In comparisons among wetlands in 2002-2003 only, amphipod biomass was lower in wetlands with lower Chl a, which might help explain the decline of amphipods since the late 1980s when Chl a was higher. The decline in Chl a corresponded to greatly increased zooplankton density in June, suggesting a shift in carbon flow from scrapers and deposit-feeders to water-column grazers. Declines in benthic and epibenthic deposit-feeding invertebrates suggest important food web effects of climate change in otherwise pristine wetlands of the boreal forest. ?? 2008 Springer Science+Business Media B.V.

  2. Dissolved organic matter as an indicator of changing watersheds in northern rivers

    Science.gov (United States)

    Aiken, G.; Spencer, R.; Striegl, R.; Raymond, P. A.

    2009-12-01

    Responses of frozen soils to climate warming is of particular significance for understanding long term climate effects on global carbon cycling and carbon export by high latitude rivers. Monitoring climate effects on carbon cycling, however, is complicated by logistical and analytical challenges associated with spatially heterogeneous processes occurring over large watershed areas. Dissolved organic matter (DOM) chemistry and flux are potentially useful, albeit underutilized, indicators of watershed change. The chemical characteristics of DOM in rivers and lakes are the net result of source materials, watershed geochemistry, oxidative processes and hydrology within these systems and upstream basins. As the large reserves of organic carbon associated with frozen soils in the northern permafrost regions are mobilized by changes in soil microbial processes and hydrologic flow paths, it is anticipated that both the composition and flux of DOM will change in waters draining these soils. Here we present results that demonstrate the utility of assessing DOM composition and flux for gaining insight into processes controlling DOM in the Yukon River and its tributaries. The Yukon River Basin is a large, diverse ecosystem in northwestern Canada and central Alaska that is experiencing increasing temperatures, partial thawing of permafrost, drying of upland soils and changing wetland environments. In our analyses of this system, we have used DOM data in two ways to define carbon cycling and transport processes throughout the basin. First, analyses of chemical composition using DOM optical properties (UV-Vis absorbance, fluorescence), isotopic composition (14C), lignin phenol content and chromatographic fractionation have provided critical information related to spatial and temporal variations in DOM exported from watersheds throughout the basin that are driven by different processes. For instance, characterization data indicate that DOM currently exported from watersheds

  3. Population ecology of breeding Pacific common eiders on the Yukon-Kuskokwim Delta, Alaska

    Science.gov (United States)

    Wilson, Heather M.; Flint, Paul L.; Powell, Abby N.; Grand, J. Barry; Moral, Christine L.

    2012-01-01

    Populations of Pacific common eiders (Somateria mollissima v-nigrum) on the Yukon-Kuskokwim Delta (YKD) in western Alaska declined by 50–90% from 1957 to 1992 and then stabilized at reduced numbers from the early 1990s to the present. We investigated the underlying processes affecting their population dynamics by collection and analysis of demographic data from Pacific common eiders at 3 sites on the YKD (1991–2004) for 29 site-years. We examined variation in components of reproduction, tested hypotheses about the influence of specific ecological factors on life-history variables, and investigated their relative contributions to local population dynamics. Reproductive output was low and variable, both within and among individuals, whereas apparent survival of adult females was high and relatively invariant (0.89 ± 0.005). All reproductive parameters varied across study sites and years. Clutch initiation dates ranged from 4 May to 28 June, with peak (modal) initiation occurring on 26 May. Females at an island study site consistently initiated clutches 3–5 days earlier in each year than those on 2 mainland sites. Population variance in nest initiation date was negatively related to the peak, suggesting increased synchrony in years of delayed initiation. On average, total clutch size (laid) ranged from 4.8 to 6.6 eggs, and declined with date of nest initiation. After accounting for partial predation and non-viability of eggs, average clutch size at hatch ranged from 2.0 to 5.8 eggs. Within seasons, daily survival probability (DSP) of nests was lowest during egg-laying and late-initiation dates. Estimated nest survival varied considerably across sites and years (mean = 0.55, range: 0.06–0.92), but process variance in nest survival was relatively low (0.02, CI: 0.01–0.05), indicating that most variance was likely attributed to sampling error. We found evidence that observer effects may have reduced overall nest survival by 0.0–0.36 across site

  4. Migratory Patterns of Wild Chinook Salmon Oncorhynchus tshawytscha Returning to a Large, Free-Flowing River Basin.

    Directory of Open Access Journals (Sweden)

    John H Eiler

    Full Text Available Upriver movements were determined for Chinook salmon Oncorhynchus tshawytscha returning to the Yukon River, a large, virtually pristine river basin. These returns have declined dramatically since the late 1990s, and information is needed to better manage the run and facilitate conservation efforts. A total of 2,860 fish were radio tagged during 2002-2004. Most (97.5% of the fish tracked upriver to spawning areas displayed continual upriver movements and strong fidelity to the terminal tributaries entered. Movement rates were substantially slower for fish spawning in lower river tributaries (28-40 km d-1 compared to upper basin stocks (52-62 km d-1. Three distinct migratory patterns were observed, including a gradual decline, pronounced decline, and substantial increase in movement rate as the fish moved upriver. Stocks destined for the same region exhibited similar migratory patterns. Individual fish within a stock showed substantial variation, but tended to reflect the regional pattern. Differences between consistently faster and slower fish explained 74% of the within-stock variation, whereas relative shifts in sequential movement rates between "hares" (faster fish becoming slower and "tortoises" (slow but steady fish explained 22% of the variation. Pulses of fish moving upriver were not cohesive. Fish tagged over a 4-day period took 16 days to pass a site 872 km upriver. Movement rates were substantially faster and the percentage of atypical movements considerably less than reported in more southerly drainages, but may reflect the pristine conditions within the Yukon River, wild origins of the fish, and discrete run timing of the returns. Movement data can provide numerous insights into the status and management of salmon returns, particularly in large river drainages with widely scattered fisheries where management actions in the lower river potentially impact harvests and escapement farther upstream. However, the substantial variation

  5. Particulate organic carbon and nitrogen export from major Arctic rivers

    Science.gov (United States)

    McClelland, J. W.; Holmes, R. M.; Peterson, B. J.; Raymond, P. A.; Striegl, R. G.; Zhulidov, A. V.; Zimov, S. A.; Zimov, N.; Tank, S. E.; Spencer, R. G. M.; Staples, R.; Gurtovaya, T. Y.; Griffin, C. G.

    2016-05-01

    Northern rivers connect a land area of approximately 20.5 million km2 to the Arctic Ocean and surrounding seas. These rivers account for ~10% of global river discharge and transport massive quantities of dissolved and particulate materials that reflect watershed sources and impact biogeochemical cycling in the ocean. In this paper, multiyear data sets from a coordinated sampling program are used to characterize particulate organic carbon (POC) and particulate nitrogen (PN) export from the six largest rivers within the pan-Arctic watershed (Yenisey, Lena, Ob', Mackenzie, Yukon, Kolyma). Together, these rivers export an average of 3055 × 109 g of POC and 368 × 109 g of PN each year. Scaled up to the pan-Arctic watershed as a whole, fluvial export estimates increase to 5767 × 109 g and 695 × 109 g of POC and PN per year, respectively. POC export is substantially lower than dissolved organic carbon export by these rivers, whereas PN export is roughly equal to dissolved nitrogen export. Seasonal patterns in concentrations and source/composition indicators (C:N, δ13C, Δ14C, δ15N) are broadly similar among rivers, but distinct regional differences are also evident. For example, average radiocarbon ages of POC range from ~2000 (Ob') to ~5500 (Mackenzie) years before present. Rapid changes within the Arctic system as a consequence of global warming make it challenging to establish a contemporary baseline of fluvial export, but the results presented in this paper capture variability and quantify average conditions for nearly a decade at the beginning of the 21st century.

  6. Transcriptomic and metabolomic analysis of Yukon Thellungiella plants grown in cabinets and their natural habitat show phenotypic plasticity

    Directory of Open Access Journals (Sweden)

    Guevara David R

    2012-10-01

    Full Text Available Abstract Background Thellungiella salsuginea is an important model plant due to its natural tolerance to abiotic stresses including salt, cold, and water deficits. Microarray and metabolite profiling have shown that Thellungiella undergoes stress-responsive changes in transcript and organic solute abundance when grown under controlled environmental conditions. However, few reports assess the capacity of plants to display stress-responsive traits in natural habitats where concurrent stresses are the norm. Results To determine whether stress-responsive changes observed in cabinet-grown plants are recapitulated in the field, we analyzed leaf transcript and metabolic profiles of Thellungiella growing in its native Yukon habitat during two years of contrasting meteorological conditions. We found 673 genes showing differential expression between field and unstressed, chamber-grown plants. There were comparatively few overlaps between genes expressed under field and cabinet treatment-specific conditions. Only 20 of 99 drought-responsive genes were expressed both in the field during a year of low precipitation and in plants subjected to drought treatments in cabinets. There was also a general pattern of lower abundance among metabolites found in field plants relative to control or stress-treated plants in growth cabinets. Nutrient availability may explain some of the observed differences. For example, proline accumulated to high levels in cold and salt-stressed cabinet-grown plants but proline content was, by comparison, negligible in plants at a saline Yukon field site. We show that proline accumulated in a stress-responsive manner in Thellungiella plants salinized in growth cabinets and in salt-stressed seedlings when nitrogen was provided at 1.0 mM. In seedlings grown on 0.1 mM nitrogen medium, the proline content was low while carbohydrates increased. The relatively higher content of sugar-like compounds in field plants and seedlings on low nitrogen

  7. STUDY OF TRANSPORTATION OF GTL PRODUCTS FROM ALASKAN NORTH SLOPE (ANS) TO MARKETS

    Energy Technology Data Exchange (ETDEWEB)

    Godwin A. Chukwu, Ph.D., P.E.

    2002-09-01

    The Alaskan North Slope is one of the largest hydrocarbon reserves in the US where Gas-to-Liquids (GTL) technology can be successfully implemented. The proven and recoverable reserves of conventional natural gas in the developed and undeveloped fields in the Alaskan North Slope (ANS) are estimated to be 38 trillion standard cubic feet (TCF) and estimates of additional undiscovered gas reserves in the Arctic field range from 64 TCF to 142 TCF. Transportation of the natural gas from the remote ANS is the key issue in effective utilization of this valuable and abundance resource. The throughput of oil through the Trans Alaska Pipeline System (TAPS) has been on decline and is expected to continue to decline in future. It is projected that by the year 2015, ANS crude oil production will decline to such a level that there will be a critical need for pumping additional liquid from GTL process to provide an adequate volume for economic operation of TAPS. The pumping of GTL products through TAPS will significantly increase its economic life. Transporting GTL products from the North Slope of Alaska down to the Marine terminal at Valdez is no doubt the great challenge facing the Gas to Liquids options of utilizing the abundant natural gas resource of the North Slope. The primary purpose of this study was to evaluate and assess the economic feasibility of transporting GTL products through the TAPS. Material testing program for GTL and GTL/Crude oil blends was designed and implemented for measurement of physical properties of GTL products. The measurement and evaluation of the properties of these materials were necessary so as to access the feasibility of transporting such materials through TAPS under cold arctic conditions. Results of the tests indicated a trend of increasing yield strength with increasing wax content. GTL samples exhibited high gel strengths at temperatures as high as 20 F, which makes it difficult for cold restart following winter shutdowns. Simplified

  8. Investigating Alaskan methane and carbon dioxide fluxes using measurements from the CARVE tower

    Science.gov (United States)

    Karion, Anna; Sweeney, Colm; Miller, John B.; Andrews, Arlyn E.; Commane, Roisin; Dinardo, Steven; Henderson, John M.; Lindaas, Jacob; Lin, John C.; Luus, Kristina A.; Newberger, Tim; Tans, Pieter; Wofsy, Steven C.; Wolter, Sonja; Miller, Charles E.

    2016-04-01

    Northern high-latitude carbon sources and sinks, including those resulting from degrading permafrost, are thought to be sensitive to the rapidly warming climate. Because the near-surface atmosphere integrates surface fluxes over large ( ˜ 500-1000 km) scales, atmospheric monitoring of carbon dioxide (CO2) and methane (CH4) mole fractions in the daytime mixed layer is a promising method for detecting change in the carbon cycle throughout boreal Alaska. Here we use CO2 and CH4 measurements from a NOAA tower 17 km north of Fairbanks, AK, established as part of NASA's Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE), to investigate regional fluxes of CO2 and CH4 for 2012-2014. CARVE was designed to use aircraft and surface observations to better understand and quantify the sensitivity of Alaskan carbon fluxes to climate variability. We use high-resolution meteorological fields from the Polar Weather Research and Forecasting (WRF) model coupled with the Stochastic Time-Inverted Lagrangian Transport model (hereafter, WRF-STILT), along with the Polar Vegetation Photosynthesis and Respiration Model (PolarVPRM), to investigate fluxes of CO2 in boreal Alaska using the tower observations, which are sensitive to large areas of central Alaska. We show that simulated PolarVPRM-WRF-STILT CO2 mole fractions show remarkably good agreement with tower observations, suggesting that the WRF-STILT model represents the meteorology of the region quite well, and that the PolarVPRM flux magnitudes and spatial distribution are generally consistent with CO2 mole fractions observed at the CARVE tower. One exception to this good agreement is that during the fall of all 3 years, PolarVPRM cannot reproduce the observed CO2 respiration. Using the WRF-STILT model, we find that average CH4 fluxes in boreal Alaska are somewhat lower than flux estimates by Chang et al. (2014) over all of Alaska for May-September 2012; we also find that enhancements appear to persist during some wintertime

  9. Contested Rivers

    DEFF Research Database (Denmark)

    Gorm Hansen, Louise Lyngfeldt

    explores translocal connections through ethnographic fieldwork at a global water conference and preliminary fieldwork at chosen locations on China's Nu River. The Nu River is one of the last undammed rivers in Asia and runs through China close to the Chinese-Burmese border, then flows into the Andaman Sea...

  10. Paleomagnetic Reconstruction of Post-Paleozoic Tectonic Motions for the Intermontane and Yukon-Tanana Terranes of Baja British Columbia

    Science.gov (United States)

    Symons, D. T.; Harris, M. J.; McCausland, P. J.; Blackburn, W. H.; Hart, C. J.

    2004-05-01

    Paleopoles from 42 Mesozoic and Cenozoic rock units in the Intermontane Belt (IMB) and Yukon-Tanana (YT) terranes are deemed to be sufficiently represented paleomagnetically and well dated radiometrically to merit consideration. Unlike previous analyses based on paleoinclination only that have led to estimates up to ˜3500 Km for northward (poleward) displacement of Baja BC relative to the North American craton, the pattern of both paleoinclination and paleodeclination are used to assess the reliability of each paleopole. The analysis indicates that: 1) the YT terrane is autochthonous or parautochthonous; 2) the IMB terranes rotated steadily atop the craton by 16° ±6° between 54 Ma and the present, accomodated by extension in the south and compression in the north; 3) the IMB terranes were rotated a further 35° ±14° and translated northward by 8° ±7° (900 Km) from 102 to 54 Ma, consistent with geological estimates for the northward displacement of interior Baja BC; and, 4) the Cache Creek, Quesnel and probably Stikine terranes were part of Baja BC since Early Jurassic.

  11. Geochemistry of surface-waters in mineralized and non-mineralized areas of the Yukon-Tanana Uplands

    Science.gov (United States)

    Wang, B.; Wanty, R.B.; Vohden, J.

    2005-01-01

    The U.S. Geological Survey (USGS) and Alaska Department of Natural Resources (ADNR) are continuing investigations on element mobility in mineralized and non-mineralized areas of the Yukon-Tanana Upland in east-central Alaska. The chemistry of stream water is evaluated in the context of regional bedrock geology and geologic structure. Sampling sites were located in the Big Delta B2 quadrangle, which includes the mineralized areas of the Pogo claim block. The area is typified by steep, subarctic-alpine, boreal forest catchment basins. Samples were collected from catchments that either cross structural features and lithologic contacts, or are underlain by a single lithology. Waters are generally dilute (ion chemistry of the waters reflects a rock-dominated aqueous system. Trace-element concentrations in water are generally low; however, As and Sb are detected near mineralized areas but in most cases rapidly attenuated downstream and processes other than simple dilution are controlling the concentrations of these trace elements. There is a tendency toward increasing SO42- concentrations downstream in waters both proximal and distal to mineralized areas. More work is necessary to determine what proportion of the increase in SO42- could be derived from the oxidation of sulfide minerals as opposed to water influenced by the underlying gneissic units.

  12. Impacts of reintroduced bison on first nations people in Yukon, Canada: Finding common ground through participatory research and social learning

    Directory of Open Access Journals (Sweden)

    Douglas A Clark

    2016-01-01

    Full Text Available From 1988-1992 wood bison (Bison bison athabascae were transplanted to the southwest Yukon, inadvertently creating concerns among local First Nations about their impacts on other wildlife, habitat, and their members' traditional livelihoods. To understand these concerns we conducted a participatory impact assessment based on a multistage analysis of existing and new qualitative data. We found wood bison had since become a valued food resource, though there was a socially-determined carrying capacity for this population. Study participants desire a population large enough to sustainably harvest but avoid crossing a threshold beyond which bison may alter the regional ecosystem. An alternative problem definition emerged that focuses on how wildlife and people alike are adapting to the observed long-term changes in climate and landscape; suggesting that a wider range of acceptable policy alternatives likely exists than may have previously been thought. Collective identification of this new problem definition indicates that this specific assessment acted as a social learning process in which the participants jointly discovered new perspectives on a problem at both individual and organisational levels. Subsequent regulatory changes, based on this research, demonstrate the efficacy of participatory impact assessment for ameliorating human-wildlife conflicts.

  13. Using a community-driven approach to identify local forest and climate change priorities in Teslin, Yukon

    Directory of Open Access Journals (Sweden)

    Joleen Timko

    2015-12-01

    Full Text Available The likelihood of addressing the complex environmental, economic, and social/cultural issues associated with local climate change impacts is enhanced when collaborative partnerships with local people are established. Using a community-centered approach in the Teslin region of Canada’s Yukon Territory, we utilized our research skills to respond to local needs for information by facilitating both an internal community process to clarify traditional and local knowledge, values, and perceptions on locally identified priorities, while gathering external information to enable local people to make sound decisions. Specifically, we sought to clarify local perceptions surrounding climate change impacts on fire risk and wildlife habitat, and the potential adaptation strategies appropriate and feasible within the Teslin Tlingit Traditional Territory. This paper provides a characterization of the study region and our project team; provides background on the interview and data collection process; presents our key results; and discusses the importance of our findings and charts a way forward for our continued work with the people in the Teslin region. This approach presents an excellent opportunity to help people holistically connect a range of local values, including fire risk mitigation, habitat enhancement, economic development, and enhanced social health.

  14. Re-analysis of Alaskan benchmark glacier mass-balance data using the index method

    Science.gov (United States)

    Van Beusekom, Ashely E.; O'Nell, Shad R.; March, Rod S.; Sass, Louis C.; Cox, Leif H.

    2010-01-01

    At Gulkana and Wolverine Glaciers, designated the Alaskan benchmark glaciers, we re-analyzed and re-computed the mass balance time series from 1966 to 2009 to accomplish our goal of making more robust time series. Each glacier's data record was analyzed with the same methods. For surface processes, we estimated missing information with an improved degree-day model. Degree-day models predict ablation from the sum of daily mean temperatures and an empirical degree-day factor. We modernized the traditional degree-day model and derived new degree-day factors in an effort to match the balance time series more closely. We estimated missing yearly-site data with a new balance gradient method. These efforts showed that an additional step needed to be taken at Wolverine Glacier to adjust for non-representative index sites. As with the previously calculated mass balances, the re-analyzed balances showed a continuing trend of mass loss. We noted that the time series, and thus our estimate of the cumulative mass loss over the period of record, was very sensitive to the data input, and suggest the need to add data-collection sites and modernize our weather stations.

  15. Extent of endocrine disruption in fish of western and Alaskan National Parks

    Science.gov (United States)

    Schreck, Carl B.; Kent, Michael

    2013-01-01

    In 2008 2009, 998 fish were collected from 43 water bodies across 11 western Alaskan national parks and analyzed for reproductive abnormalities. Exposure to estrogenic substances such as pesticides can induce abnormalities like intersex. Results suggest there is a greater propensity for male intersex fish collected from parks located in the Rocky Mountains, and specifically in Rocky Mountain NP. Individual male intersex fish were also identified at Lassen Volcanic, Yosemite, and WrangellSt. Elias NPs. The preliminary finding of female intersex was determined to be a false positive. The overall goal of this project was to assess the general health of fish from eleven western national parks to infer whether health impacts may be linked to contaminant health thresholds for animal andor human health. This was accomplished by evaluating the presence of intersex fish with eggs developing in male gonads or sperm developing in female gonads using histology. In addition, endocrine disrupting compounds and other contaminants were quantified in select specimens. General histologic appearance of the gonadal tissue and spleen were observed to assess health.

  16. Cost-Optimal Pathways to 75% Fuel Reduction in Remote Alaskan Villages: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Simpkins, Travis; Cutler, Dylan; Hirsch, Brian; Olis, Dan; Anderson, Kate

    2015-10-28

    There are thousands of isolated, diesel-powered microgrids that deliver energy to remote communities around the world at very high energy costs. The Remote Communities Renewable Energy program aims to help these communities reduce their fuel consumption and lower their energy costs through the use of high penetration renewable energy. As part of this program, the REopt modeling platform for energy system integration and optimization was used to analyze cost-optimal pathways toward achieving a combined 75% reduction in diesel fuel and fuel oil consumption in a select Alaskan village. In addition to the existing diesel generator and fuel oil heating technologies, the model was able to select from among wind, battery storage, and dispatchable electric heaters to meet the electrical and thermal loads. The model results indicate that while 75% fuel reduction appears to be technically feasible it may not be economically viable at this time. When the fuel reduction target was relaxed, the results indicate that by installing high-penetration renewable energy, the community could lower their energy costs by 21% while still reducing their fuel consumption by 54%.

  17. Attitudes toward harm reduction and abstinence-only approaches to alcohol misuse among Alaskan college students

    Directory of Open Access Journals (Sweden)

    Monica C. Skewes

    2013-08-01

    Full Text Available Background. Harm reduction is a public health approach that aims to guide hazardous drinkers to change unsafe drinking and minimize alcohol-related consequences without requiring abstinence. In contrast, abstinence-based interventions are designed for people with more severe alcohol problems and they aim to eliminate consequences via complete abstinence from alcohol. Current best practices for treating college student alcohol misuse involve harm reduction strategies, but no research has been conducted examining students’ perceptions of these strategies. Objective. Understanding attitudes is critical prior to the implementation of an intervention in a new setting, particularly when attitudes may serve as barriers to treatment enrolment and retention. For this reason, we sought to examine attitudes toward contrasting alcohol misuse interventions among college students in two large public universities in the circumpolar north. Design. A web-based survey was conducted with 461 students from two public universities in Alaska. Participants completed questionnaires assessing attitudes toward alcohol treatment, current drinking behaviour, and demographic information. Results. Findings indicated that emerging adult (18–25 years old students who would be targets of future interventions (hazardous drinkers evidenced more positive attitudes toward harm reduction than abstinence-only approaches. Conclusion. This research provides support for the implementation of harm reduction intervention strategies for Alaskan college students who misuse alcohol. It is likely that harm reduction will be acceptable in this population.

  18. Children's Depression Inventory: A unidimensional factor structure for American Indian and Alaskan native youth.

    Science.gov (United States)

    Scott, Walter D; Clapp, Joshua; Mileviciute, Inga; Mousseau, Alicia

    2016-01-01

    Given that American Indian and Alaskan Native (AI/AN) youth are at increased risk for a variety of depression-related outcomes and may experience depression uniquely, the fact that the factor structure of the Children's Depression Inventory (CDI; Kovacs, 1992) is unknown for these populations represents a significant obstacle. In Study 1 with an AI youth sample, we conducted confirmatory factor analyses and failed to find support for either of the 2 predominant CDI multifactor models (Craighead, Smucker, Craighead, & Ilardi, 1998; Kovacs, 1992). In subsequent exploratory structural equation modeling, we found the most support for a unidimensional factor structure. In Study 2, using confirmatory modeling with independent AI/AN youth samples, we found further support for this unidimensional model. Finally, in Study 3, we found support across AI/AN groups varying in gender and age for measurement invariance with respect to both factor structure and factor loadings. Overall, for these AI/AN youth populations, our findings support the practice of calculating total CDI scores, and they suggest a unique construction of the depression experience.

  19. Transport of fecal bacteria by boots and vehicle tires in a rural Alaskan community.

    Science.gov (United States)

    Chambers, Molly K; Ford, Malcolm R; White, Daniel M; Barnes, David L; Schiewer, Silke

    2009-02-01

    People living without piped water and sewer can be at increased risk for diseases transmitted via the fecal-oral route. One rural Alaskan community that relies on hauling water into homes and sewage from homes was studied to determine the pathways of fecal contamination of drinking water and the human environment so that barriers can be established to protect health. Samples were tested for the fecal indicator, Escherichia coli, and the less specific indicator group, total coliforms. Shoes transported fecal contamination from outside to floor material inside buildings. Contamination in puddles on the road, in conjunction with contamination found on all-terrain vehicle (ATV) tires, supports vehicle traffic as a mechanism for transporting contamination from the dumpsite or other source areas to the rest of the community. The abundance of fecal bacteria transported around the community on shoes and ATV tires suggests that centralized measures for waste disposal as well as shoe removal in buildings could improve sanitation and health in the community.

  20. Chemical and biological assessment of two offshore drilling sites in the Alaskan Arctic.

    Science.gov (United States)

    Trefry, John H; Dunton, Kenneth H; Trocine, Robert P; Schonberg, Susan V; McTigue, Nathan D; Hersh, Eric S; McDonald, Thomas J

    2013-05-01

    A retrospective chemical and biological study was carried out in Camden Bay, Alaskan Beaufort Sea, where single exploratory oil wells were drilled at two sites more than two decades ago. Barium from discharged drilling mud was present in sediments at concentrations as high as 14%, ~200 times above background, with significantly higher concentrations of Ba, but not other metals, within 250 m of the drilling site versus reference stations. Elevated concentrations of Cr, Cu, Hg and Pb were found only at two stations within 25 m of one drilling site. Concentrations of total polycyclic aromatic hydrocarbons (TPAH) were not significantly different at reference versus drilling-site stations; however, TPAH were elevated in Ba-rich layers from naturally occurring perylene in ancient formation cuttings. Infaunal biomass and species abundance were not significantly different at reference versus drilling-site stations; infauna were less diverse at drilling-site stations. Our assessment showed that discharges from single wells within large areas caused minimal long-term, adverse impacts to the benthic ecosystem.

  1. Measuring melt and velocity of Alaskan mountain glaciers using phase-sensitive radar and differential GPS

    Science.gov (United States)

    Neuhaus, S.; Tulaczyk, S. M.

    2015-12-01

    Alaskan glaciers show some of the highest rates of retreat worldwide, contributing to sea level rise. This retreat is due to both increased velocity and increased melt. We seek to understand the role of glacial meltwater on velocity. Matanuska glacier, a land terminating glacier in Alaska, has been well-studied using traditional glaciological techniques, but new technology has emerged that allows us to measure melt and velocity more accurately. We employed high-resolution differential GPS to create surface velocity profiles across flow in the ablation zone during the summer of 2015. We also measured surface ablation using stakes and measured basal melt using phase-sensitive radar designed by the British Antarctic Survey. The positions acquired by differential GPS are obtained to a resolution of less than 0.5m, while feature tracking using time-lapse photography for the same time period yields positions with greater and more variable uncertainty. The phase-sensitive radar provides ice thinning rates. Phase-sensitive radar together with ground penetrating radar provides us with an understanding of the internal structure of the glacier. This suite of data allows us to determine the relative importance of surface melt, basal melt, and internal deformation on ice velocity in warm mountain glaciers.

  2. Hepatitis C Virus in American Indian/Alaskan Native and Aboriginal Peoples of North America

    Directory of Open Access Journals (Sweden)

    Julia Uhanova

    2012-12-01

    Full Text Available Liver diseases, such as hepatitis C virus (HCV, are “broken spirit” diseases. The prevalence of HCV infection for American Indian/Alaskan Native (AI/AN in the United States and Canadian Aboriginals varies; nonetheless, incidence rates of newly diagnosed HCV infection are typically higher relative to non-indigenous people. For AI/AN and Aboriginal peoples risk factors for the diagnosis of HCV can reflect that of the general population: predominately male, a history of injection drug use, in midlife years, with a connection with urban centers. However, the face of the indigenous HCV infected individual is becoming increasingly female and younger compared to non-indigenous counterparts. Epidemiology studies indicate that more effective clearance of acute HCV infection can occur for select Aboriginal populations, a phenomenon which may be linked to unique immune characteristics. For individuals progressing to chronic HCV infection treatment outcomes are comparable to other racial cohorts. Disease progression, however, is propelled by elevated rates of co-morbidities including type 2 diabetes and alcohol use, along with human immunodeficiency virus (HIV co-infection relative to non-indigenous patients. Historical and personal trauma has a major role in the participation of high risk behaviors and associated diseases. Although emerging treatments provide hope, combating HCV related morbidity and mortality will require interventions that address the etiology of broken spirit diseases.

  3. Increases in body weight and nutritional status of transplanted Alaskan caribou

    Directory of Open Access Journals (Sweden)

    Patrick Valkenburg

    2000-04-01

    Full Text Available Body weight and natality rate in ungulates can be useful indices to nutririon, bur they may also be influenced by genetic and climatic factors. Because caribou {Rangifer tarandus granti are distributed as discrete populations of metapopulations (i.e., herds that are usually reproductively isolated from each other for unknown periods, it is difficult to separate the influence of genetics and nutrition on body weight, especially where historical data are lacking. To help elucidate the influence of nutrition on potential variation in body weight and natality of caribou in Alaska, we reviewed data for body weight and natality in 5 populations which resulted from Transplants to previously ungrazed ranges, or to areas where reindeer and caribou had been absent for many decades. In 2 of 5 populations body weight increased significantly, and likely increased in the other 3 populations, but data were insufficient. Natality rate increased in all 5 populations, proportion of fecund yearlings was high and 3 of the 5 newly established herds increased at about the maximum biological potential for the species (lambda=1.35. In the Adak transplant, a lactating yearling was documented. These 5 transplanted populations provide additional evidence that body weight and natality rate in Alaskan caribou are sensitive to changes in population density and relatively short-term (i.e., 10 years increases in grazing pressure independenr of climate and genetics.

  4. Seabirds as a subsistence and cultural resource in two remote Alaskan communities

    Directory of Open Access Journals (Sweden)

    Rebecca C. Young

    2014-12-01

    Full Text Available Small rural Alaskan communities face many challenges surrounding rapid social and ecological change. The role of local subsistence resources may change over time because of changes in social perception, economic need, and cultural patterns of use. We look at the Bering Sea's Pribilof Islands, comprising two very small communities, and investigate the relationship between the local residents and seabirds as a natural resource. Seabirds may strengthen ties to older ways of life and have potential for future economic opportunities, or modernization may direct interest away from seabirds as a cultural and economic resource. We conducted a survey and interviews of residents of the two Pribilof Island communities, St. Paul and St. George, to assess opinions toward seabirds and harvest levels. Seabirds were generally regarded as important both to individuals and the wider community. However, current levels of subsistence harvest are low, and few people continue to actively harvest or visit seabird colonies. Respondents expressed desire for greater knowledge about seabirds and also concerns about the current economy of the islands and a lack of future development prospects. Despite the challenging economic conditions, the villages retain a strong sense of community and place value on their environment and on seabirds. Surveys indicated an interest in developing eco-tourism based around local resources, including seabirds, as a way to improve the economy.

  5. Tracking Particulate Organic Matter Characteristics in Major Arctic Rivers: Indicators of Watershed-Scale Climate Impacts

    Science.gov (United States)

    McClelland, J. W.; Griffin, C. G.; Holmes, R. M.; Peterson, B. J.; Raymond, P. A.; Spencer, R. G.; Striegl, R. G.; Tank, S. E.

    2015-12-01

    Six large rivers, including the Yukon and Mackenzie in North America and the Yenisey, Ob', Lena, and Kolyma in Eurasia, drain the majority of the watershed area surrounding the Arctic Ocean. Parallel sampling programs were initiated at downstream locations on these rivers in 2003 to improve estimates of fluvial export and track large-scale perturbations associated with climate change. Over a decade later, synthesis of water chemistry data from these ongoing sampling efforts provides an unprecedented opportunity to 1) examine similarities and differences among the major Arctic rivers, and 2) think critically about how changes in various water chemistry parameters may or may not inform us about climate change impacts. River-borne organic matter characteristics may be particularly telling because mass flux values and composition/source indicators vary with hydrology and permafrost coverage. However, separating climate impacts that occur within river corridors from those that occur beyond them may be difficult, especially when considering changes in particulate organic matter (POM) loads. Data on suspended POM yields, C:N ratios, stable isotope ratios, and radiocarbon content in the major Arctic rivers show marked spatial, seasonal, and interannual variability that is helpful for thinking about how climate change effects may manifest in the future, but it will be challenging to separate changes in POM related to bank erosion and suspension/deposition of in situ sediment stocks from changes in POM that may be linked to processes such as permafrost thaw occurring across the broader landscape.

  6. Repeat Photography of Alaskan Glaciers and Landscapes as Both Art and as a Means of Communicating Climat Change

    Science.gov (United States)

    Molnia, B. F.

    2013-12-01

    For nearly 15 years, I have used repeat photography of Alaskan glaciers and landscapes to communicate to fellow scientists, policymakers, the media, and society that Alaskan glaciers and landscapes have been experiencing significant change in response to post-Little Ice Age climate change. I began this pursuit after being contacted by a U.S. Department of the Interior senior official who requested unequivocal and unambiguous documentation that climate change was real and underway. After considering several options as to how best respond to this challenge, I decided that if a picture is worth a thousand words, then a pair of photographs, both with the same field of view, spanning a century or more, and showing dramatic differences, would speak volumes to documenting that dynamic climate change is occurring over a very broad region of Alaska. To me, understating the obvious with photographic pairs was the best mechanism to present irrefutable, unambiguous, nonjudgmental, as well as unequivocal visual documentation that climate change was both underway and real. To date, more than 150 pairs that meet these criteria have been produced. What has surprised me most is that the many of the photographs contained in the pairs present beautiful images of stark, remote landscapes that convey the majestic nature of this dynamic region with its unique topography and landscapes. Typically, over periods of just several decades, the photographed landscapes change from black and white to blue and green. White ice becomes blue water and dark rock becomes lush vegetation. Repeat photography is a technique in which a historical photograph and a modern photograph, both having the same field of view, are compared and contrasted to quantitatively and qualitatively determine their similarities and differences. I have used this technique from both ground-based photo stations and airborne platforms at Alaskan locations in Kenai Fjords National Park, Glacier Bay National Park and Preserve

  7. GIS-based identification of areas with mineral resource potential for six selected deposit groups, Bureau of Land Management Central Yukon Planning Area, Alaska

    Science.gov (United States)

    Jones, James V.; Karl, Susan M.; Labay, Keith A.; Shew, Nora B.; Granitto, Matthew; Hayes, Timothy S.; Mauk, Jeffrey L.; Schmidt, Jeanine M.; Todd, Erin; Wang, Bronwen; Werdon, Melanie B.; Yager, Douglas B.

    2015-01-01

    This study, covering the Bureau of Land Management (BLM) Central Yukon Planning Area (CYPA), Alaska, was prepared to aid BLM mineral resource management planning. Estimated mineral resource potential and certainty are mapped for six selected mineral deposit groups: (1) rare earth element (REE) deposits associated with peralkaline to carbonatitic intrusive igneous rocks, (2) placer and paleoplacer gold, (3) platinum group element (PGE) deposits associated with mafic and ultramafic intrusive igneous rocks, (4) carbonate-hosted copper deposits, (5) sandstone uranium deposits, and (6) tin-tungsten-molybdenum-fluorspar deposits associated with specialized granites. These six deposit groups include most of the strategic and critical elements of greatest interest in current exploration.

  8. Dynamics of a small surge-type glacier, St. Elias Mountains, Yukon Territory, Canada: characterization of basal motion using 1-D geophysical inversion

    OpenAIRE

    Paoli, Laetitia

    2009-01-01

    The dynamics of a small surge-type glacier are investigated as part of a study to characterize glacier response to climate in southwest Yukon Territory, Canada. DEMs of the glacier surface and bed are constructed from surface elevation and ice thickness data. Measured surface velocities are higher than expected for a surge-type glacier in its quiescent phase over the upper 3500m of the 5km-long glacier, but much lower than typical surge velocities. Flowline basal velocities are reconstructed ...

  9. Seasonal variation of upwelling in the Alaskan Beaufort Sea: Impact of sea ice cover

    Science.gov (United States)

    Schulze, Lena M.; Pickart, Robert S.

    2012-06-01

    Data from a mooring array deployed from August 2002 to September 2004 are used to characterize differences in upwelling near the shelf break in the Alaskan Beaufort Sea due to varying sea ice conditions. The record is divided into three ice seasons: open water, partial ice, and full ice. The basic response is the same in each of the seasons. Roughly 8 h after the onset of easterly winds the shelf break jet reverses, followed approximately 10 h later by upwelling of saltier water which is cold near the shelf break (Pacific Winter Water) and warm at depth (Atlantic Water). The secondary circulation at the outer shelf is, to first order, consistent with a two-dimensional Ekman balance of offshore flow in the upper layer and onshore flow at depth. There are, however, important seasonal differences in the upwelling. Overall the response is strongest in the partial ice season and weakest in the full ice season. It is believed that these differences are dictated by the degree to which wind stress is transmitted through the pack-ice, as the strength of the wind-forcing was comparable over the three seasons. An EOF-based upwelling index is constructed using information about the primary flow, secondary flow, and hydrography. The ability to predict upwelling using the wind record alone is explored, which demonstrates that 90% of easterly wind events exceeding 9.5 m s-1 drive significant upwelling. During certain periods the ice cover on the shelf became landfast, which altered the upwelling and circulation patterns near the shelf break.

  10. Deciduous Tree Species Alter Nitrogen and Phosphorus Availability in Mid-successional Alaskan Boreal Forest

    Science.gov (United States)

    Melvin, A. M.; Mack, M. C.; Johnstone, J. F.; Schuur, E. A.

    2013-12-01

    In Alaskan boreal forest, increased fire severity associated with climate change is altering successional processes and ecosystem nutrient dynamics. Fire is a common disturbance in Interior Alaska and typically burns forests dominated by black spruce (Picea mariana), a tree species associated with slow nutrient turnover and high soil organic matter accumulation rates. Historically, low severity fires have driven black spruce regeneration post-fire, thereby maintaining slow nutrient cycling rates and large soil organic matter stocks. In contrast, high severity fires consume the organic layer and can lead to the establishment of deciduous tree species on exposed mineral soil, which produce less recalcitrant leaf litter and exhibit faster nutrient cycling rates. To improve our understanding of the long-term impacts of tree species composition on nutrient cycling in boreal forest, we quantified nitrogen (N) cycling rates and estimated soil N, phosphorus (P), and base cation pools in adjacent, mid-successional stands of black spruce and Alaska paper birch (Betula neoalaskana) that established following a 1960 fire near Fairbanks, Alaska. Results indicate significantly higher net N mineralization in paper birch soils relative to black spruce for both the fibric organic layer and top 10 cm of mineral soil during 30-day and 90-day lab incubation studies. Net nitrification was significantly higher in the paper birch fibric layer after 90 days. Total soil N concentrations did not differ between paper birch and black spruce stands, however the black spruce organic layer was significantly larger than that of birch, resulting in larger organic layer N stocks (130 vs. 87 g N m2). In contrast, total P concentrations were significantly higher in the organic layer in birch forest, but the total P stocks did not differ significantly between species because of the larger mass of soil organic matter in the black spruce. These findings suggest that a shift towards greater deciduous

  11. Fort Yukon, Alaska DOE Implementation Grant Gwich'in Solar and Energy Efficiency in the Arctic Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Cadzow, Janet [Gwichyaa Zhee Gwich' in Tribal Government, Fort Yukon, AK (United States); Messier, Dave [Gwichyaa Zhee Gwich' in Tribal Government, Fort Yukon, AK (United States)

    2017-01-30

    Gwichyaa Zhee Gwich’in Tribal Government (GZGTG) applied for funding in 2014 under the U.S. Department of Energy Office of Indian Energy Deployment of Clean Energy on Tribal Lands funding opportunity. They were awarded 50% of the project costs for the construction of an 18kW, grid-tied solar PV array on the fort Yukon Tribal Hall, the construction of a 3kW solar PV array on the tribally owned greenhouse, the replacement of inefficient florescent lighting fixtures in the tribal hall to higher efficiency LED lights and the addition of blow in cellulose insulation to the attic of the tribal hall to assist with heat retention. Total DOE Funding for the project was $124,735. Total GZGTG funding for the project was $133,321 for a total project cost of $258,056. The Project was completed with 100% local labor on the tribal hall solar PV installation, the LED lighting retrofit and the insulation on the tribal hall. Based on the results at the tribal hall/office, the tribe also used their own tribal funding to retrofit the lighting in the community hall from florescent to LED lights. The resulting project was completed by the end of Sept 2016 and results have shown a decrease in fuel used at the tribal hall/office of 35% and a decrease in electric costs at the tribal hall of 68%. The total energy costs before the project were approximately $28,000 a year and the energy equivalent of 385 MMBTU/yr. After the project the total energy costs decreased to $11,200/yr. and an energy equivalent of only 242 MMBTU. This represents an overall decrease in energy use of 38%. All in all the tribe and the community regard this project as a huge success!

  12. Debris flow susceptibility mapping using a qualitative heuristic method and Flow-R along the Yukon Alaska Highway Corridor, Canada

    Science.gov (United States)

    Blais-Stevens, A.; Behnia, P.

    2016-02-01

    This research activity aimed at reducing risk to infrastructure, such as a proposed pipeline route roughly parallel to the Yukon Alaska Highway Corridor (YAHC), by filling geoscience knowledge gaps in geohazards. Hence, the Geological Survey of Canada compiled an inventory of landslides including debris flow deposits, which were subsequently used to validate two different debris flow susceptibility models. A qualitative heuristic debris flow susceptibility model was produced for the northern region of the YAHC, from Kluane Lake to the Alaska border, by integrating data layers with assigned weights and class ratings. These were slope angle, slope aspect, surficial geology, plan curvature, and proximity to drainage system. Validation of the model was carried out by calculating a success rate curve which revealed a good correlation with the susceptibility model and the debris flow deposit inventory compiled from air photos, high-resolution satellite imagery, and field verification. In addition, the quantitative Flow-R method was tested in order to define the potential source and debris flow susceptibility for the southern region of Kluane Lake, an area where documented debris flow events have blocked the highway in the past (e.g. 1988). Trial and error calculations were required for this method because there was not detailed information on the debris flows for the YAHC to allow us to define threshold values for some parameters when calculating source areas, spreading, and runout distance. Nevertheless, correlation with known documented events helped define these parameters and produce a map that captures most of the known events and displays debris flow susceptibility in other, usually smaller, steep channels that had not been previously documented.

  13. Holocene environmental change in the subarctic alpine treeline in northern British Columbia and the southern Yukon Territory, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Pisaric, M.F.J.

    2001-07-01

    Compilations of temperature data show that compared to the last several hundred years, the temperature in many parts of the world has been very high. This warmer temperature is believed to be caused by an increase in anthropogenically derived greenhouse gases. It was argued that instrumental temperature records are not adequate for assessing the impact of human activity on climate because they are very short, and a knowledge of past climatic variations is needed for longer time scales to accurately assess the natural variability of climate. Past climatic variations can also be used to see how vegetation will respond to additional warming in the coming century. This study examined the relationship between modern vegetation and pollen and stomate dispersal with particular reference to treeline dynamics and vegetation-climate relationships in the subalpine treeline in northwestern Canada. The study examined whether major vegetation assemblages can be distinguished from one another through pollen and stomate characteristics. It also investigated postglacial treeline fluctuations in the northern Rocky Mountains to see if they are driven by seasonal and latitudinal changes in distribution of solar radiation, or if they are driven by disturbance factors such as fire. Lastly, the study examined whether the twentieth century temperature increases in northeastern British Columbia and the Yukon have exceeded the natural variability of temperature in the region during the past centuries. Results suggest that climate-growth relationships are complex and the factors controlling them change with time, but it was determined that vegetation development is related to both climate change and higher fire activity. The higher temperatures in the past century most probably reflect increased levels of greenhouse gases.

  14. Permafrost Changes along the Alaska Highway Corridor, Southern Yukon, from Ground Temperature Measurements and DC Electrical Resistivity Tomography

    Science.gov (United States)

    Duguay, M. A.; Lewkowicz, A. G.; Smith, S.

    2011-12-01

    A natural gas pipeline running across permafrost terrain from Prudhoe Bay, Alaska, through Canada to US markets was first proposed more than 30 years ago. In the intervening period, mean annual air temperatures in the region have risen by 0.5-1.0°C and it is probable that the ground has also warmed. Renewed interest in the pipeline has meant that information on permafrost and geotechnical conditions within the Alaska Highway Corridor of the southern Yukon must be updated for engineering design and the assessment of environmental impacts. To accomplish this goal, results from 1977-1981 drilling and ground temperature monitoring programs within the proposed pipeline corridor were used in combination with air photo analysis to select sites potentially sensitive to climate change. The sites are distributed across the extensive and sporadic discontinuous permafrost zones over a distance of 475 km between Beaver Creek and Whitehorse. To date, 11 targeted boreholes with permafrost have been found and cased to permit renewed ground temperature monitoring. By the end of summer 2011, it is expected that another 7 will have been instrumented. Measurable temperature increases relative to the 1970s are expected, except where values were previously just below 0°C. In the latter case, if the sites are still in permafrost, latent heat effects may have substantially moderated the temperature increase. Electrical resistivity tomography surveys are also being conducted to characterize the local permafrost distribution and geotechnical conditions. These 2D resistivity profiles will be used with the ground temperatures to examine current conditions and response to climate change and vegetation disturbance.

  15. River nomads

    DEFF Research Database (Denmark)

    2016-01-01

    River nomads is a movie about people on the move. The documentary film explores the lifestyle of a group of nomadic fishermen whose mobility has been the recipe of success and troubles. Engaged in trade and travel, twice a year the river nomads form impressive convoys of majestic pirogues and set...... and liberated lifestyle and the breath-taking landscapes and vistas offered by the Niger River. River Nomads is also a personal account of the Kebbawa’s way of life and their current struggles as nomadic folk living in a world divided by borders and ruled by bureaucrats....

  16. Water Temperature Dynamics in High Arctic River Basins

    Science.gov (United States)

    Blaen, P. J.; Hannah, D. M.; Brown, L. E.; Milner, A. M.

    2012-04-01

    Despite the high sensitivity of polar regions to climate change, and the strong influence of temperature upon ecosystem processes, contemporary understanding of water temperature dynamics in Arctic river systems is limited. This research gap is addressed by exploring high-resolution water column thermal regimes for glacier-fed and non-glacial rivers at eight sites across Svalbard during the 2010 melt season. Mean water column temperatures in glacier-fed rivers (0.3 - 3.2 °C) were the lowest and most thermally-stable near the glacier terminus but increased downstream (0.7 - 2.3 °C km-1). Non-glacial rivers, where discharge was sourced primarily from snowmelt, were warmer (mean 2.9 - 5.7 °C) and more variable, indicating increased water residence times in shallow alluvial zones with increased potential for atmospheric influence. Mean summer water temperature and the magnitude of daily thermal variation were similar to those of Alaskan rivers but low at all sites when compared to alpine glacierized environments at lower latitudes. Thermal regimes were strongly correlated (pgeomorphological features (e.g. channel morphology). These results provide insight into the potential changes in high-latitude river systems in the context of projected warming in polar regions. We hypothesise warmer and more variable temperature regimes may prevail in future as the proportion of bulk discharge sourced from glacial meltwater declines and rivers undergo a progressive shift towards snow- and groundwater sources. Importantly, such changes could have implications for species diversity and abundance in benthic communities and influence rates of ecosystem functioning in high-latitude aquatic systems.

  17. Report to Pacific Flyway Study Committee and Waterfowl Conservation Committee on the 1985-1988 breeding pairs indices for geese and swans from aerial surveys of the coastal zone, Yukon Delta, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The final year of·the 4-year study to develop an aerial survey of geese nesting in the coastal zone of the Yukon Delta has been completed. Tne survey was flown from...

  18. An integrated assessment of Porcupine caribou seasonal distribution, movements, and habitat preferences for regional land use planning in northern Yukon Territory, Canada

    Directory of Open Access Journals (Sweden)

    John L. Ryder

    2007-04-01

    Full Text Available This study was undertaken to improve understanding of Porcupine caribou herd distribution, movements, and habitat preferences to assist with developing a regional land use plan for the North Yukon Planning Region, Yukon Territory. Three different methods were used to identify current and historical patterns of caribou distribution and habitat preferences within the region to prioritize conservation areas. Two of the approaches focused on incorporating information on caribou distribution and migrations from scientific and local knowledge, while the third focused on identifying and mapping habitats suitable for supporting caribou. Local knowledge dating back to the 1930s and two decades of satellite telemetry data confirmed that most of the planning region is used by the Porcupine caribou herd and highlighted areas of concentrated use. Maps of suitable winter habitat derived from expert opinion ratings of habitat use did not agree with the other information sources. The local knowledge and satellite telemetry analyses were used to identify spatially explicit priority areas for caribou conservation and the results were applied to develop conservation recommendations for a draft regional land use plan. The plan will be submitted to government approval bodies for review in the spring of 2007. The success in implementing conservation strategies for the Porcupine caribou herd will be reviewed and evaluated following adoption of a final approved plan.

  19. MACROSCOPIC RIVERS

    NARCIS (Netherlands)

    VANDENBERG, IP

    1991-01-01

    We present a mathematical model for the ''river-phenomenon'': striking concentrations of trajectories of ordinary differential equations. This model of ''macroscopic rivers'' is formulated within nonstandard analysis, and stated in terms of macroscopes and singular perturbations. For a subclass, the

  20. Use of fish hydrolysates and fishmeal by-products of the Alaskan fishing industry in diets for Pacific white shrimp (Litopenaeus vannamei)

    Science.gov (United States)

    The suitability of four fish hydrolysates and two fishmeals derived from by-products of the Alaskan fishing industry, as menhaden fishmeal replacements in shrimp diets was determined. A control diet (30% crude protein and 8.5% crude lipid) was produced with menhaden meal (13% of diet). Experimental ...

  1. Historical changes in trace metals and hydrocarbons in nearshore sediments, Alaskan Beaufort Sea, prior and subsequent to petroleum-related industrial development: Part I. Trace metals.

    Science.gov (United States)

    Naidu, A Sathy; Blanchard, Arny L; Misra, Debasmita; Trefry, John H; Dasher, Douglas H; Kelley, John J; Venkatesan, M Indira

    2012-10-01

    Concentrations of Fe, As, Ba, Cd, Cu, Cr, Pb, Mn, Ni, Sn, V and Zn in mud (drilling effluents. In Prudhoe Bay, concentration spikes of metals in ∼1988 presumably reflect enhanced metals deposition following maximum oil drilling in 1980s. In summary, the Alaskan Arctic nearshore has remained generally free of metal contamination despite petroleum-related activities in past 40 years.

  2. Apolipoprotein E isoforms 3/3 and 3/4 differentially interact with circulating stearic, palmitic, and oleic fatty acids and lipid levels in Alaskan Natives.

    Science.gov (United States)

    Castellanos-Tapia, Lyssia; López-Alvarenga, Juan Carlos; Ebbesson, Sven O E; Ebbesson, Lars O E; Tejero, M Elizabeth

    2015-04-01

    Lifestyle changes in Alaskan Natives have been related to the increase of cardiovascular disease and metabolic syndrome in the last decades. Variation of the apolipoprotein E (Apo E) genotype may contribute to the diverse response to diet in lipid metabolism and influence the association between fatty acids in plasma and risk factors for cardiovascular disease. The aim of this investigation was to analyze the interaction between Apo E isoforms and plasma fatty acids, influencing phenotypes related to metabolic diseases in Alaskan Natives. A sample of 427 adult Siberian Yupik Alaskan Natives was included. Fasting glucose, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, Apo A1, and Apo B plasma concentrations were measured using reference methods. Concentrations of 13 fatty acids in fasting plasma were analyzed by gas chromatography, and Apo E variants were identified. Analyses of covariance were conducted to identify Apo E isoform and fatty acid main effects and multiplicative interactions. The means for body mass index and age were 26 ± 5.2 and 47 ± 1.5, respectively. Significant main effects were observed for variation in Apo E and different fatty acids influencing Apo B levels, triglycerides, and total cholesterol. Significant interactions were found between Apo E isoform and selected fatty acids influencing total cholesterol, triglycerides, and Apo B concentrations. In summary, Apo E3/3 and 3/4 isoforms had significant interactions with circulating levels of stearic, palmitic, oleic fatty acids, and phenotypes of lipid metabolism in Alaskan Natives.

  3. Tissue Distribution of Polychlorinated Biphenyls and Organochlorine Pesticides and Potential Toxicity to Alaskan Northern Fur Seals Assessed Using PCBs Congener Specific Mode of Action Schemes

    Science.gov (United States)

    The concentrations of 145 polychlorinated biphenyl (PCB) congeners were measured using gas chromatography-ion trap mass spectrometry in 8 different tissues (blubber, brain, heart, kidney, liver, lung, muscle, and reproductive tissues) of 10 Alaskan northern fur seals. The mean concentrations of bot...

  4. Alaskan Superintendent Turnover: Is There a Correlation between Anticipated Turnover and the Organizational Culture of School Boards in the State of Alaska

    Science.gov (United States)

    Herbert, David M. Q.

    2012-01-01

    The purpose of this study is to determine if a particular type of school board culture is predictive of Alaskan public school superintendents' intention to leave their positions. Cameron and Quinn's four types of organizational culture--hierarchy, market, clan, and adhocracy--serve as the model for the study, which surveyed Alaska's…

  5. Detrital Zircon Geochronology of Cretaceous and Paleogene Strata Across the South-Central Alaskan Convergent Margin

    Science.gov (United States)

    Bradley, Dwight; Haeussler, Peter; O'Sullivan, Paul; Friedman, Rich; Till, Alison; Bradley, Dan; Trop, Jeff

    2009-01-01

    Talkeetna Mountains (schist of Hatcher Pass) and, immediately to the south, the northernmost sedimentary sequence of the Matanuska forearc basin (Arkose Ridge Formation). Detrital zircons from the Paleogene Arkose Ridge Formation are as young as 61 and 70 Ma; the population is dominated by a single Late Cretaceous peak at 76 Ma; the oldest zircon is 181 Ma. Sedimentological evidence clearly shows that the conglomeratic Arkose Ridge Formation was derived from the Talkeetna Mountains; our detrital zircon data support this inference. Zircons dated at ca. 90 Ma in the Arkose Ridge sample suggest that buried or unmapped plutons of this age may exist in the Talkeetnas. This is a particularly interesting age as it corresponds to the age of the supergiant Pebble gold-molybdenum-copper porphyry prospect near Iliamna and suggests a new area of prospectivity for Pebble-type deposits. The schist of Hatcher Pass, which was previously assigned a Jurassic depositional age, yielded surprisingly young Late Cretaceous detrital zircons, the youngest at 75 Ma. The probability density curve has four Cretaceous peaks from 76 to 102 Ma, a pair of Late Jurassic peaks at 155 and 166 Ma, three Early Jurassic to Late Triassic peaks at 186, 197, and 213 Ma, minor Carboniferous peaks at 303 and 346 Ma, and a minor Paleoproterozoic peak at 1828 Ma. The schist of Hatcher Pass was largely derived from Mesozoic arc sources, most likely the Wrangellia composite terrane, with some contribution from one or more older, inboard sources, probably including the Yukon-Tanana terrane. We postulate that the schist of Hatcher Pass represents metamorphosed rocks of the Valdez Group that were subducted and then exhumed along the Chugach terrane's 'backstop' during Paleogene transtension. Western Alaska Range - Six detrital zircon samples were collected from a little studied belt of turbidites in Tyonek quadrangle on strike with the Kahiltna assemblage of the central Alaska Range. Many of the sandstones ar

  6. The contribution of Alaskan, Siberian, and Canadian coastal polynas to the cold halocline layer of the Arctic Ocean

    Science.gov (United States)

    Cavalieri, Donald J.; Martin, Seelye

    1994-01-01

    Numerous Arctic Ocean circulation and geochemical studies suggest that ice growth in polynyas over the Alaskan, Siberian, and Canadian continental shelves is a source of cold, saline water which contributes to the maintenance of the Arctic Ocean halocline. The purpose of this study is to estimate for the 1978-1987 winters the contributions of Arctic coastal polynyas to the cold halocline layer of the Arctic Ocean. The study uses a combination of satellite, oceanographic, and weather data to calculate the brine fluxes from the polynyas; then an oceanic box model is used to calculate their contributions to the cold halocline layer of the Arctic Ocean. This study complements and corrects a previous study of dense water production by coastal polynyas in the Barents, Kara, and Laptev Seas.

  7. Petrology of a Neoproterozoic Alaskan-type complex from the Eastern Desert of Egypt: Implications for mantle heterogeneity

    Science.gov (United States)

    Khedr, Mohamed Zaki; Arai, Shoji

    2016-10-01

    This paper details petrological and geochemical studies of an ultramafic-mafic intrusion in the Southern Eastern Desert of Egypt. The Dahanib complex shows a concentric zonation, from dunites at the core, through chromitites, clinopyroxene-rich dunites, wehrlites, harzburgites, gabbronorites and layered gabbros, to hornblende gabbros/diorites at the rim, similar to other Alaskan-type complexes. These lithologies typically feature cumulate textures and layering. Their pyroxenes (Mg#s, 0.54-0.94) evidence Fe, Mn and Na enrichment, but Al, Cr, Mg and Ti are depleted with differentiation. Their chromian spinels have a wide range of Cr# (0.31-0.61), along with high Ti and Fe, as a result of their origin through crystal accumulation and reaction with interstitial liquids. The clinopyroxenes (Cpxs) in peridotites and gabbroic rocks, which are high in REE concentration (2-100 times chondrite), are depleted in LREE relative to HREE and are similar to Cpx crystallized from asthenospheric melts. The mineral inclusions in spinel, the chemistry of Cpx in peridotites (rich in Al, Cr, Na, Ti and ΣREE = 13.7), and the melts in equilibrium with Cpx suggest that the Neoproterozoic lithosphere were partially refertilized by trace asthenospheric melts. The early magmas were possibly enriched by Mg, Cr, Ni, Ti, V and Sr, while the evolved types were rich in Fe, Mn, Na, Li, Zr, Co and REE via crystal accumulation and the interaction with interstitial liquids. The Neoproterozoic sub-arc mantle in Egypt is chemically heterogeneous and generally low in Nb, Ta, Zr and K, due to the low solubility of HFSE in slab-derived fluids and no other external addition of these elements. The large variations in lithology and chemistry, as well as the occurrence of scattered chromitite clots in the Dahanib peridotites, are related to a continuous supply of primitive magmas and/or the reaction between interstitial liquids and early cumulus crystals during multistage fractional crystallization. The

  8. Basin-Scale Exports vs. Coastal Delivery of Carbon, Nutrients and Particulates Above and Below Arctic River Deltas

    Science.gov (United States)

    Striegl, R. G.; Tank, S. E.; Weeks, G.; Holmes, R. M.; McClelland, J. W.

    2014-12-01

    , and advance our understanding of arctic river inputs to coastal environments. We use examples from the Yukon and Mackenzie River deltas in USA and Canada to illustrate those needs.

  9. A progress report on fishery surveys along the route of the proposed Trans-Alaska Pipeline between the Yukon River and Atigun Pass during 1971

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This progress report represents a summary of findings of the field work conducted by USFWS during the summer of 1971 along the route of the proposed Trans-Alaska...

  10. Press releases, preliminary maps, and preliminary reports released by the Geologic Branch and Alaskan Branch between January 1, 1938 and January 1, 1945

    Science.gov (United States)

    Kent, Lois S.; Keroher, R.P.

    1945-01-01

    This pamphlet contains a complete list of all maps and reports issued by the Geologic Branch and Alaskan Branch of the Geological Survey whose release was announced by press notice during the period between January 1, 1938 and January 1, 1945. The Geologic Branch material was compiled by Lois S. Kent, and the Alaskan Branch material by R. P. Kerocher. It is expected that similar lists will be published annually hereafter. These reports and maps are the results of work carried out by Survey geologists on mineral deposits in the United States, Alaska, and Cuba during the war and the years immediately preceding the war. They were released in preliminary form as rapidly as possible in this period to avoid the delays necessarily attendant upon formal publication and to make the information contained in them promptly available to property owners and mine operators concerned with the production of strategic and critical mineral commodities.

  11. Non-electric applications of geothermal energy in six Alaskan towns. Final report, October 1976--November 1977. [Barrow, Huslia, Kiana, Nikolski, Nome, and Wrangell

    Energy Technology Data Exchange (ETDEWEB)

    Farquhar, J.; Grijalva, R.; Kirkwood, P.

    1977-11-01

    The potential for direct (non-electric) utilization of local-gradient geothermal energy in six Alaskan towns is summarized. A major objective of this study was to stimulate development and use of the geothermal resource provided by the earth's average thermal gradient, as opposed to the few anomalies that are typically chosen for geothermal development. Hence, six towns for study were selected as being representative of remote Alaskan conditions, rather than for their proximity to known geothermal resources. The moderate-temperature heat available almost everywhere at depths of two to four kilometers into the earth's mantle could satisfy a major portion of the nation's heating requirements--but the cost must be reduced. It is concluded that a geothermal demonstration in Nome would probably be successful and would promote this objective.

  12. A RAB3GAP1 SINE Insertion in Alaskan Huskies with Polyneuropathy, Ocular Abnormalities, and Neuronal Vacuolation (POANV Resembling Human Warburg Micro Syndrome 1 (WARBM1

    Directory of Open Access Journals (Sweden)

    Michaela Wiedmer

    2016-02-01

    Full Text Available We observed a hereditary phenotype in Alaskan Huskies that was characterized by polyneuropathy with ocular abnormalities and neuronal vacuolation (POANV. The affected dogs developed a progressive severe ataxia, which led to euthanasia between 8 and 16 months of age. The pedigrees were consistent with a monogenic autosomal recessive inheritance. We localized the causative genetic defect to a 4 Mb interval on chromosome 19 by a combined linkage and homozygosity mapping approach. Whole genome sequencing of one affected dog, an obligate carrier, and an unrelated control revealed a 218-bp SINE insertion into exon 7 of the RAB3GAP1 gene. The SINE insertion was perfectly associated with the disease phenotype in a cohort of 43 Alaskan Huskies, and it was absent from 541 control dogs of diverse other breeds. The SINE insertion induced aberrant splicing and led to a transcript with a greatly altered exon 7. RAB3GAP1 loss-of-function variants in humans cause Warburg Micro Syndrome 1 (WARBM1, which is characterized by additional developmental defects compared to canine POANV, whereas Rab3gap1-deficient mice have a much milder phenotype than either humans or dogs. Thus, the RAB3GAP1 mutant Alaskan Huskies provide an interesting intermediate phenotype that may help to better understand the function of RAB3GAP1 in development. Furthermore, the identification of the presumed causative genetic variant will enable genetic testing to avoid the nonintentional breeding of affected dogs.

  13. Controls on variations in MODIS fire radiative power in Alaskan boreal forests: implications for fire severity conditions

    Science.gov (United States)

    Barrett, Kirsten; Kasischke, Eric S.

    2013-01-01

    Fire activity in the Alaskan boreal forest, though episodic at annual and intra-annual time scales, has experienced an increase over the last several decades. Increases in burned area and fire severity are not only releasing more carbon to the atmosphere, but likely shifting vegetation composition in the region towards greater deciduous dominance and a reduction in coniferous stands. While some recent studies have addressed qualitative differences between large and small fire years in the Alaskan boreal forest, the ecological effects of a greater proportion of burning occurring during large fire years and during late season fires have not yet been examined. Some characteristics of wildfires that can be detected remotely are related to fire severity and can provide new information on spatial and temporal patterns of burning. This analysis focused on boreal wildfire intensity (fire radiative power, or FRP) contained in the Moderate Resolution Imaging Spectroradiometer (MODIS) daily active fire product from 2003 to 2010. We found that differences in FRP resulted from seasonality and intra-annual variability in fire activity levels, vegetation composition, latitudinal variation, and fire spread behavior. Our studies determined two general categories of active fire detections: new detections associated with the spread of the fire front and residual pixels in areas that had already experienced front burning. Residual pixels had a lower average FRP than front pixels, but represented a high percentage of all pixels during periods of high fire activity (large fire years, late season burning, and seasonal periods of high fire activity). As a result, the FRP from periods of high fire activity was less intense than those from periods of low fire activity. Differences related to latitude were greater than expected, with higher latitudes burning later in the season and at a higher intensity than lower latitudes. Differences in vegetation type indicate that coniferous vegetation

  14. Utilizing Colored Dissolved Organic Matter to Derive Dissolved Black Carbon Export by Arctic Rivers

    Directory of Open Access Journals (Sweden)

    Aron eStubbins

    2015-10-01

    Full Text Available Wildfires have produced black carbon (BC since land plants emerged. Condensed aromatic compounds, a form of BC, have accumulated to become a major component of the soil carbon pool. Condensed aromatics leach from soils into rivers, where they are termed dissolved black carbon (DBC. The transport of DBC by rivers to the sea is a major term in the global carbon and BC cycles. To estimate Arctic river DBC export, 25 samples collected from the six largest Arctic rivers (Kolyma, Lena, Mackenzie, Ob’, Yenisey and Yukon were analyzed for dissolved organic carbon (DOC, colored dissolved organic matter (CDOM, and DBC. A simple, linear regression between DOC and DBC indicated that DBC accounted for 8.9 ± 0.3% DOC exported by Arctic rivers. To improve upon this estimate, an optical proxy for DBC was developed based upon the linear correlation between DBC concentrations and CDOM light absorption coefficients at 254 nm (a254. Relatively easy to measure a254 values were determined for 410 Arctic river samples between 2004 and 2010. Each of these a254 values was converted to a DBC concentration based upon the linear correlation, providing an extended record of DBC concentration. The extended DBC record was coupled with daily discharge data from the six rivers to estimate riverine DBC loads using the LOADEST modeling program. The six rivers studied cover 53% of the pan-Arctic watershed and exported 1.5 ± 0.1 million tons of DBC per year. Scaling up to the full area of the pan-Arctic watershed, we estimate that Arctic rivers carry 2.8 ± 0.3 million tons of DBC from land to the Arctic Ocean each year. This equates to ~8% of Arctic river DOC export, slightly less than indicated by the simpler DBC vs DOC correlation-based estimate. Riverine discharge is predicted to increase in a warmer Arctic. DBC export was positively correlated with river runoff, suggesting that the export of soil BC to the Arctic Ocean is likely to increase as the Arctic warms.

  15. Utilizing Colored Dissolved Organic Matter to Derive Dissolved Black Carbon Export by Arctic Rivers

    Science.gov (United States)

    Stubbins, Aron; Spencer, Robert; Mann, Paul; Holmes, R.; McClelland, James; Niggemann, Jutta; Dittmar, Thorsten

    2015-10-01

    Wildfires have produced black carbon (BC) since land plants emerged. Condensed aromatic compounds, a form of BC, have accumulated to become a major component of the soil carbon pool. Condensed aromatics leach from soils into rivers, where they are termed dissolved black carbon (DBC). The transport of DBC by rivers to the sea is a major term in the global carbon and BC cycles. To estimate Arctic river DBC export, 25 samples collected from the six largest Arctic rivers (Kolyma, Lena, Mackenzie, Ob’, Yenisey and Yukon) were analyzed for dissolved organic carbon (DOC), colored dissolved organic matter (CDOM), and DBC. A simple, linear regression between DOC and DBC indicated that DBC accounted for 8.9 ± 0.3% DOC exported by Arctic rivers. To improve upon this estimate, an optical proxy for DBC was developed based upon the linear correlation between DBC concentrations and CDOM light absorption coefficients at 254 nm (a254). Relatively easy to measure a254 values were determined for 410 Arctic river samples between 2004 and 2010. Each of these a254 values was converted to a DBC concentration based upon the linear correlation, providing an extended record of DBC concentration. The extended DBC record was coupled with daily discharge data from the six rivers to estimate riverine DBC loads using the LOADEST modeling program. The six rivers studied cover 53% of the pan-Arctic watershed and exported 1.5 ± 0.1 million tons of DBC per year. Scaling up to the full area of the pan-Arctic watershed, we estimate that Arctic rivers carry 2.8 ± 0.3 million tons of DBC from land to the Arctic Ocean each year. This equates to ~8% of Arctic river DOC export, slightly less than indicated by the simpler DBC vs DOC correlation-based estimate. Riverine discharge is predicted to increase in a warmer Arctic. DBC export was positively correlated with river runoff, suggesting that the export of soil BC to the Arctic Ocean is likely to increase as the Arctic warms.

  16. Multitemporal L- and C-Band Synthetic Aperture Radar To Highlight Differences in Water Status Among Boreal Forest and Wetland Systems in the Yukon Flats, Interior Alaska

    Science.gov (United States)

    Balser, Andrew W.; Wylie, Bruce K.

    2010-01-01

    Tracking landscape-scale water status in high-latitude boreal systems is indispensible to understanding the fate of stored and sequestered carbon in a climate change scenario. Spaceborne synthetic aperture radar (SAR) imagery provides critical information for water and moisture status in Alaskan boreal environments at the landscape scale. When combined with results from optical sensor analyses, a complementary picture of vegetation, biomass, and water status emerges. Whereas L-band SAR showed better inherent capacity to map water status, C-band had much more temporal coverage in this study. Analysis through the use of L- and C-band SARs combined with Landsat Enhanced Thematic Mapper Plus (ETM+) enables landscape stratification by vegetation and by seasonal and interannual hydrology. Resultant classifications are highly relevant to biogeochemistry at the landscape scale. These results enhance our understanding of ecosystem processes relevant to carbon balance and may be scaled up to inform regional carbon flux estimates and better parameterize general circulation models (GCMs).

  17. Petrogenesis of postcollisional magmatism at Scheelite Dome, Yukon, Canada: Evidence for a lithospheric mantle source for magmas associated with intrusion-related gold systems

    Science.gov (United States)

    Mair, John L.; Farmer, G. Lang; Groves, David I.; Hart, Craig J.R.; Goldfarb, Richard J.

    2011-01-01

    The type examples for the class of deposits termed intrusion-related gold systems occur in the Tombstone-Tungsten belt of Alaska and Yukon, on the eastern side of the Tintina gold province. In this part of the northern Cordillera, extensive mid-Cretaceous postcollisional plutonism took place following the accretion of exotic terranes to the continental margin. The most cratonward of the resulting plutonic belts comprises small isolated intrusive centers, with compositionally diverse, dominantly potassic rocks, as exemplified at Scheelite Dome, located in central Yukon. Similar to other spatially and temporally related intrusive centers, the Scheelite Dome intrusions are genetically associated with intrusion-related gold deposits. Intrusions have exceptional variability, ranging from volumetrically dominant clinopyroxene-bearing monzogranites, to calc-alkaline minettes and spessartites, with an intervening range of intermediate to felsic stocks and dikes, including leucominettes, quartz monzonites, quartz monzodiorites, and granodiorites. All rock types are potassic, are strongly enriched in LILEs and LREEs, and feature high LILE/HFSE ratios. Clinopyroxene is common to all rock types and ranges from salite in felsic rocks to high Mg augite and Cr-rich diopside in lamprophyres. Less common, calcic amphibole ranges from actinolitic hornblende to pargasite. The rocks have strongly radiogenic Sr (initial 87Sr/86Sr from 0.711-0.714) and Pb isotope ratios (206Pb/204Pb from 19.2-19.7), and negative initial εNd values (-8.06 to -11.26). Whole-rock major and trace element, radiogenic isotope, and mineralogical data suggest that the felsic to intermediate rocks were derived from mafic potassic magmas sourced from the lithospheric mantle via fractional crystallization and minor assimilation of metasedimentary crust. Mainly unmodified minettes and spessartites represent the most primitive and final phases emplaced. Metasomatic enrichments in the underlying lithospheric mantle

  18. Spatial genetic structure of Long-tailed Ducks (Clangula hyemalis) among Alaskan, Canadian, and Russian breeding populations

    Science.gov (United States)

    Wilson, Robert E.; Gust, J R; Petersen, Margaret; Talbot, Sandra

    2016-01-01

    Arctic ecosystems are changing at an unprecedented rate. How Arctic species are able to respond to such environmental change is partially dependent on the connections between local and broadly distributed populations. For species like the Long-tailed Duck (Clangula hyemalis), we have limited telemetry and band-recovery information from which to infer population structure and migratory connectivity; however, genetic analyses can offer additional insights. To examine population structure in the Long-tailed Duck, we characterized variation at mtDNA control region and microsatellite loci among four breeding areas in Alaska, Canada, and Russia. We observed significant differences in the variance of mtDNA haplotype frequencies between the Yukon-Kuskokwim Delta (YKD) and the three Arctic locations (Arctic Coastal Plain in Alaska, eastern Siberia, and central Canadian Arctic). However, like most sea duck genetic assessments, our study found no evidence of population structure based on autosomal microsatellite loci. Long-tailed Ducks use multiple wintering areas where pair formation occurs with some populations using both the Pacific and Atlantic Oceans. This situation provides a greater opportunity for admixture across breeding locales, which would likely homogenize the nuclear genome even in the presence of female philopatry. The observed mtDNA differentiation was largely due to the presence of two divergent clades: (A) a clade showing signs of admixture among all breeding locales and (B) a clade primarily composed of YKD samples. We hypothesize that the pattern of mtDNA differentiation reflects some degree of philopatry to the YKD and isolation of two refugial populations with subsequent expansion and admixture. We recommend additional genetic assessments throughout the circumpolar range of Long-tailed Ducks to further quantify aspects of genetic diversity and migratory connectivity in this species.

  19. Purification of Alaskan walleye pollock (Gadus chalcogrammus) and New Zealand hoki (Macruronus novaezelandiae) liver oil using short path distillation.

    Science.gov (United States)

    Oliveira, Alex C M; Miller, Matthew R

    2014-05-22

    The beneficial health effects of a diet rich in n-3 long chain polyunsaturated fatty acids (n-3 LC-PUFA) have been extensively researched in recent years. Marine oils are an important dietary source of n-3 LC-PUFA, being especially rich in two of the most important fatty acids of this class, EPA (eicosapentaenoic acid; 20:5n-3) and DHA (docosahexaenoic acid; 22:6n-3). Oils rich in n-3 LC-PUFA are prone to oxidation that leads to loss of product quality. Alaskan pollock (Gadus chalcogrammus Pallas, 1814) and New Zealand's hoki (Macruronus novaezelandiae Hector, 1871) are the highest volume fisheries of their respective countries. Both produce large quantities of fishery byproducts, in particular crude or unrefined n-3 LC-PUFA containing oils. Presently these oils are used as ingredients for animal feed, and only limited quantities are used as human nutritional products. The aim of this research was to investigate the applicability of short path distillation for the purification of pollock and hoki oil to produce purified human-grade fish oil to meet quality specifications. Pollock and hoki oils were subjected to short path distillation and a significant decrease in free fatty acids and lipid oxidation (peroxide and para-anisidine values) products was observed. Purified oils met the Global Organization for EPA and DHA Omega-3 (GOED) standard for edible fish oils.

  20. Purification of Alaskan Walleye Pollock (Gadus chalcogrammus and New Zealand Hoki (Macruronus novaezelandiae Liver Oil Using Short Path Distillation

    Directory of Open Access Journals (Sweden)

    Alex C. M. Oliveira

    2014-05-01

    Full Text Available The beneficial health effects of a diet rich in n-3 long chain polyunsaturated fatty acids (n-3 LC-PUFA have been extensively researched in recent years. Marine oils are an important dietary source of n-3 LC-PUFA, being especially rich in two of the most important fatty acids of this class, EPA (eicosapentaenoic acid; 20:5n-3 and DHA (docosahexaenoic acid; 22:6n-3. Oils rich in n-3 LC-PUFA are prone to oxidation that leads to loss of product quality. Alaskan pollock (Gadus chalcogrammus Pallas, 1814 and New Zealand’s hoki (Macruronus novaezelandiae Hector, 1871 are the highest volume fisheries of their respective countries. Both produce large quantities of fishery byproducts, in particular crude or unrefined n-3 LC-PUFA containing oils. Presently these oils are used as ingredients for animal feed, and only limited quantities are used as human nutritional products. The aim of this research was to investigate the applicability of short path distillation for the purification of pollock and hoki oil to produce purified human-grade fish oil to meet quality specifications. Pollock and hoki oils were subjected to short path distillation and a significant decrease in free fatty acids and lipid oxidation (peroxide and para-anisidine values products was observed. Purified oils met the Global Organization for EPA and DHA Omega-3 (GOED standard for edible fish oils.

  1. Population structure of invasive Streptococcus pneumoniae isolates among Alaskan children in the conjugate vaccine era, 2001 to 2013.

    Science.gov (United States)

    Miernyk, Karen M; Bulkow, Lisa R; Case, Samantha L; Zulz, Tammy; Bruce, Michael G; Harker-Jones, Marcella; Hurlburt, Debby A; Hennessy, Thomas W; Rudolph, Karen M

    2016-10-01

    Here we describe the relationships between serotypes, genotypes, and antimicrobial susceptibility among isolates causing invasive pneumococcal disease in Alaskan children during the pneumococcal conjugate vaccine (PCV) era. From 2001 to 2013 we received 271 isolates representing 33 serotypes. The most common serotypes were 19A (29.5%, n= 80), 7F (12.5%, n= 34), 15B/C (6.3%, n= 17), and 22F (4.8%, n= 13). Multilocus sequence typing identified 11 clonal complexes (CC) and 45 singletons. Five CCs accounted for 52% (141/271) of the total: CC199 (21% [n= 57], serotypes 19A, 15B/C), CC191 (12.2% [n= 33], serotype 7F), CC172 (10.3% [n= 28], serotypes 19A, 23A, 23B), CC433 (4.4% [n= 12], serotype 22F), and CC100 (4.4% [n= 12], serotype 33F). The proportion of isolates nonsusceptible to erythromycin and tetracycline increased after 13-valent PCV use (14% [n= 30] versus 29% [n= 14]; P= 0.010) and (4% [n= 9] versus 22% [n= 11]; P< 0.001), respectively. The genetic diversity also increased after 13-valent PCV use (Simpson's diversity index =0.95 versus 0.91; P= 0.022).

  2. STARCH/PULP-FIBER BASED PACKAGING FOAMS AND CAST FILMS CONTAINING ALASKAN FISH BY-PRODUCTS (WASTE

    Directory of Open Access Journals (Sweden)

    Syed H. Imam

    2008-08-01

    Full Text Available Baked starch/pulp foams were prepared from formulations containing zero to 25 weight percent of processed Alaskan fish by-products that consisted mostly of salmon heads, pollock heads, and pollock frames (bones and associated remains produced in the filleting operation. Fish by-products thermoformed well along with starch and pulp fiber, and the foam product (panels exhibited useful mechanical properties. Foams with all three fish by-products, ranging between 10 and 15 wt%, showed the highest flexural modulus (500-770 Mpa. Above 20% fiber content, the modulus dropped considerably in all foam samples. Foam panels with pollock frames had the highest flexural modulus, at about 15% fiber content (770 Mpa. Foams with salmon heads registered the lowest modulus, at 25% concentration. Attempts were also made to cast starch-glycerol-poly (vinyl alcohol films containing 25% fish by-product (salmon heads. These films showed a tensile strength of 15 Mpa and elongation at break of 78.2%. All foams containing fish by-product degraded well in compost at ambient temperature (24oC, loosing roughly between 75-80% of their weight within 7 weeks. The films degraded at a much higher rate initially. When left in water, foams prepared without fish by-product absorbed water much more quickly and deteriorated faster, whereas, water absorption in foams with fish by-product was initially delayed and/or slowed for about 24 h. After this period, water absorption was rapid.

  3. Mechanosensory Neuron Aging: Differential Trajectories with Lifespan-Extending Alaskan Berry and Fungal Treatments in Caenorhabditis elegans

    Science.gov (United States)

    Scerbak, Courtney; Vayndorf, Elena M.; Hernandez, Alicia; McGill, Colin; Taylor, Barbara E.

    2016-01-01

    Many nutritional interventions that increase lifespan are also proposed to postpone age-related declines in motor and cognitive function. Potential sources of anti-aging compounds are the plants and fungi that have adapted to extreme environments. We studied the effects of four commonly consumed and culturally relevant Interior Alaska berry and fungus species (bog blueberry, lowbush cranberry, crowberry, and chaga) on the decline in overall health and neuron function and changes in touch receptor neuron morphology associated with aging. We observed increased wild-type Caenorhabditis elegans lifespan and improved markers of healthspan upon treatment with Alaskan blueberry, lowbush cranberry, and chaga extracts. Interestingly, although all three treatments increased lifespan, they differentially affected the development of aberrant morphologies in touch receptor neurons. Blueberry treatments decreased anterior mechanosensory neuron (ALM) aberrations (i.e., extended outgrowths and abnormal cell bodies) while lowbush cranberry treatment increased posterior mechanosensory neuron (PLM) aberrations, namely process branching. Chaga treatment both decreased ALM aberrations (i.e., extended outgrowths) and increased PLM aberrations (i.e., process branching and loops). These results support the large body of knowledge positing that there are multiple cellular strategies and mechanisms for promoting health with age. Importantly, these results also demonstrate that although an accumulation of abnormal neuron morphologies is associated with aging and decreased health, not all of these morphologies are detrimental to neuronal and organismal health. PMID:27486399

  4. Fate of carbon in Alaskan Landscapes Project: database for soils from eddy covariance tower sites, Delta Junction, AK

    Science.gov (United States)

    King, Stagg; Harden, Jennifer; Manies, Kristen L.; Munster, Jennie; White, L. Douglas

    2002-01-01

    Soils in Alaska, and in high latitude terrestrial ecosystems in general, contain significant amounts of organic carbon, most of which is believed to have accumulated since the start of the Holocene about 10 ky before present. High latitude soils are estimated to contain 30-40% of terrestrial soil carbon (Melillo et al., 1995; McGuire and Hobbie, 1997), or ~ 300-400 Gt C (Gt = 1015 g), which equals about half of the current atmospheric burden of carbon. Boreal forests in particular are estimated to have more soil carbon than any other terrestrial biome (Post et al., 1982; Chapin and Matthews, 1993). The relations among net primary production, soil carbon storage, recurrent fire disturbance, nutrients, the hydrologic cycle, permafrost and geomorphology are poorly understood in boreal forest. Fire disturbance has been suggested to play a key role in the interactions among the complex biogeochemical processes influencing carbon storage in boreal forest soils (Harden et al., 2000; Zhuang et al., 2002). There has been an observed increase in fire disturbance in North American boreal black spruce (Picea mariana) forests in recent decades (Murphy et al., 1999; Kasichke et al., 2000), concurrent with increases in Alaskan boreal and arctic surface temperatures and warming of permafrost (Osterkamp and Romanofsky, 1999). Understanding the role of fire in long term carbon storage and how recent changes in fire frequency and severity may influence future high latitude soil carbon pools is necessary for those working to understand or mitigate the effects of global climate change.

  5. A Consistent Radar Altimetry Dataset for Major World Rivers: Extraction Methods and Preliminary Data Products

    Science.gov (United States)

    Coss, S. P.; Durand, M. T.; Tuozzolo, S.; Yi, Y.; Jia, Y.; Guo, Q.; Shum, C. K.

    2015-12-01

    Our group has made several efforts to develop the systematics for processing multiple satellite mission inland altimetry data with the purpose of creating a pre-SWOT climate data record of world's rivers greater than 900m in width. The project is a component of a NASA MEaSUREs (Making Earth System Data Records for Use in Research Environments) project undertaken by UCLA, Princeton U., NASA/GSFC and Ohio State Univ. The first method developed allows for the identification of measurements that represent the target river through height filtering and is based on USGS flow data from 105 gauges on rivers with watersheds over 20,000 km2. Proximal topographic variations led to some contamination of the radar returns. We were able to identify them using the previously mentioned height filter, and correlated their frequency with near-river topographic indices. Significant efforts have also been made to detect river ice using only radar backscatter. Over 631 Landsat images were processed and given an ice cover designation then compared with measured backscatter profiles; demonstrating that isolating a one- to-one relationship between ice and backscatter will be challenging. An additional focus of the group has been automation of detecting altimeter/river intersections as well as the creation of "virtual stations" or masks for data extraction at those locations. Using RivWidth parameters to generate polygons and a raster proximity based intersection detection methods have both shown promising results for automation of this process. This project will soon be producing validated climate data records in the form of geocentric river height changes, both in terms of scale of the study area and access to previously unmonitored regions. Once established, these methods will also be applicable to the study of future satellite cycles. Preliminary river height change data products have been produced for the Mississippi, St Lawrence, Yukon, Mackenzie, and part of the Ganges

  6. The modeled effects of fire on carbon balance and vegetation abundance in Alaskan tundra

    Science.gov (United States)

    Dietze, M. C.; Davidson, C. D.; Kelly, R.; Higuera, P. E.; Hu, F.

    2012-12-01

    Arctic climate is warming at a rate disproportionately faster than the rest of the world. Changes have been observed within the tundra that are attributed to this trend, including active layer thickening, shrub land expansion, and increases in fire frequency. Whether tundra remains a global net sink of carbon could depend upon the effects of fire on vegetation, specifically concerning the speed at which vegetation reestablishes, the stimulation of growth after fire, and the changes that occur in species composition during succession. While rapid regeneration of graminoid vegetation favors the spread of this functional type in early succession, late succession appears to favor shrub vegetation at abundances greater than those observed before fire. Possible reasons for this latter observation include changes in albedo, soil insulation, and soil moisture regimes. Here we investigate the course of succession after fire disturbance within tundra ecosystems, and the mechanisms involved. A series of simulated burn experiments were conducted on the burn site left by the 2007 Anaktuvuk River fire to access the behavior of the Ecosystem Demography model v2.2 (ED2) in the simulation of fire on the tundra. The land surface sub-model within ED is modified to improve simulate permafrost through the effects of an increased soil-column depth, a peat texture class, and the effects of wind compaction and depth hoar on snow density. Parameterization is conducted through Bayesian techniques used to constrain parameter distributions based upon data from a literature survey, field measurements at Toolik Lake, Alaska, and a data assimilation over three datasets. At each step, priority was assigned to measurements that could constrain parameters that account for the greatest explained variance in model output as determined through sensitivity analysis. Following parameterization, a series of simulations were performed to gauge the suitability of the model in predicting carbon balance and

  7. Linking climate change projections for an Alaskan watershed to future coho salmon production.

    Science.gov (United States)

    Leppi, Jason C; Rinella, Daniel J; Wilson, Ryan R; Loya, Wendy M

    2014-06-01

    Climate change is predicted to dramatically change hydrologic processes across Alaska, but estimates of how these impacts will influence specific watersheds and aquatic species are lacking. Here, we linked climate, hydrology, and habitat models within a coho salmon (Oncorhynchus kisutch) population model to assess how projected climate change could affect survival at each freshwater life stage and, in turn, production of coho salmon smolts in three subwatersheds of the Chuitna (Chuit) River watershed, Alaska. Based on future climate scenarios and projections from a three-dimensional hydrology model, we simulated coho smolt production over a 20-year span at the end of the century (2080-2100). The direction (i.e., positive vs. negative) and magnitude of changes in smolt production varied substantially by climate scenario and subwatershed. Projected smolt production decreased in all three subwatersheds under the minimum air temperature and maximum precipitation scenario due to elevated peak flows and a resulting 98% reduction in egg-to-fry survival. In contrast, the maximum air temperature and minimum precipitation scenario led to an increase in smolt production in all three subwatersheds through an increase in fry survival. Other climate change scenarios led to mixed responses, with projected smolt production increasing and decreasing in different subwatersheds. Our analysis highlights the complexity inherent in predicting climate-change-related impacts to salmon populations and demonstrates that population effects may depend on interactions between the relative magnitude of hydrologic and thermal changes and their interactions with features of the local habitat.

  8. Carbon and nutrient responses to fire and climate warming in Alaskan arctic tundra

    Science.gov (United States)

    Jiang, Y.; Rastetter, E. B.; Shaver, G. R.; Rocha, A. V.; Kwiatkowski, B.; Pearce, A.; Zhuang, Q.; Mishra, U.

    2015-12-01

    Fire frequency has dramatically increased in the tundra of northern Alaska, which has major implications for the carbon budget of the region and the functioning of these ecosystems that support important wildlife species. We applied the Multiple Element Limitation (MEL) model to investigate both the short- and long-term post-fire succession of plant and soil carbon, nitrogen, and phosphorus fluxes and stocks along a burn severity gradient in the 2007 Anaktuvuk River Fire scar in northern Alaska. We compared the patterns of biomass and soil carbon, nitrogen and phosphorus recoveries with different burn severities and warming intensities. Modeling results indicated that the early regrowth of post-fire tundra vegetation was limited primarily by its canopy photosynthetic potential, rather than nutrient availability. The long-term recovery of C balance from fire disturbance is mainly determined by the internal redistribution of nutrients among ecosystem components, rather than the supply of nutrients from external sources (e.g., nitrogen deposition and fixation, phosphorus weathering). Soil organic matter is the principal source of plant-available nutrients and determines the spatial variation of vegetation biomass across the North Slope of Alaska. Across the North Slope of Alaska, we examined the effects of changes in N and P cycles on tundra C budgets under climate warming. Our results indicate that the ongoing climate warming in Arctic enhances mineralization and leads to a net transfer of nutrient from soil organic matter to vegetation, thereby stimulating tundra plant growth and increased C sequestration in the tundra ecosystems.

  9. Time-scales of assembly and thermal history of a composite felsic pluton: constraints from the Emerald Lake area, northern Canadian Cordillera, Yukon

    Science.gov (United States)

    Coulson, Ian M.; Villeneuve, Mike E.; Dipple, Gregory M.; Duncan, Robert A.; Russell, James K.; Mortensen, James K.

    2002-05-01

    Knowledge of the time-scales of emplacement and thermal history during assembly of composite felsic plutons in the shallow crust are critical to deciphering the processes of crustal growth and magma chamber development. Detailed petrological and chemical study of the mid-Cretaceous, composite Emerald Lake pluton, from the northern Canadian Cordillera, Yukon Territory, coupled with U-Pb and 40Ar/ 39Ar geochronology, indicates that this pluton was intruded as a series of magmatic pulses. Intrusion of these pulses produced a strong petrological zonation from augite syenite, hornblende quartz syenite and monzonite, to biotite granite. Our data further indicate that multiple phases were emplaced and cooled to below the mineral closure temperatures over a time-scale on the order of the resolution of the 40Ar/ 39Ar technique (˜1 Myr), and that emplacement occurred at 94.3 Ma. Simple thermal modelling and heat conduction calculations were used to further constrain the temporal relationships within the intrusion. These calculations are consistent with the geochronology and show that emplacement and cooling were complete in less than 100 kyr and probably 70±5 kyr. These results demonstrate that production, transport and emplacement of the different phases of the Emerald Lake pluton occurred essentially simultaneously, and that these processes must also have been closely related in time and space. By analogy, these results provide insights into the assembly and petrogenesis of other complex intrusions and ultimately lead to an understanding of the processes involved in crustal development.

  10. Resilience strategies in the face of short- and long-term change: out-migration and fisheries regulation in Alaskan fishing communities

    Directory of Open Access Journals (Sweden)

    Amber Himes-Cornell

    2015-06-01

    Full Text Available Historically, communities persisted in remote, isolated areas of Alaska in large part because of the abundance of marine and terrestrial resources, as well as the ability of local people to opportunistically access those resources as they became available. Species switching and the ability to shift effort away from fisheries during poor years allowed local residents to diversify their livelihoods in the face of uncertainties and ecological change. The advent of modern fisheries management, which views Alaskan fisheries as the property of all citizens of the United States, has fundamentally altered the relationship of place-based communities to fishery resources. Local access to fisheries has been particularly affected by the development of transferable fishing privileges, making it possible for fishing rights to leave place-based communities through the choices of individual community members to sell or to move away. When fishing communities in Alaska lose active fishing businesses, over time the loss of various types of community capital will follow, including human, social, cultural, technical, and financial capital. In some cases, communities are able to adapt or transform through diversification of their local economies. In other cases, no alternatives to a fishery-based economy are accessible. We have used resilience theory to explore drivers of change affecting Alaskan fishing communities. Emphasis was placed on two primary change drivers, the regulatory environment and rural out-migration, as well as their interconnections and their impacts on individuals, communities, and the larger social-ecological system. We summarized several government programs that have been implemented to support the continued participation of communities in Alaskan fisheries. In addition, we reviewed informal and private-sector efforts to generate resilience strategies that can facilitate new entry into fisheries or retain fishing businesses and fishing rights

  11. Petrogenesis of the Alaskan-type mafic-ultramafic complex in the Makkah quadrangle, western Arabian Shield, Saudi Arabia

    Science.gov (United States)

    Habtoor, Abdelmonem; Ahmed, Ahmed Hassan; Harbi, Hesham

    2016-10-01

    -rich and Fe-rich varieties. All spinel varieties in the mafic-ultramafic rocks have high Fe3 + and TiO2 contents. The estimated melt composition in equilibrium with Gabal Taftafan complex is mostly similar to that of the SSZ boninitic magmas. The Taftafan mafic-ultramafic rocks show many similarities with the Alaskan-type mafic-ultramafic complexes, including the internal zonal lithology, bulk rock geochemistry, and mineral chemistry. Thus, it is neither related to a fragment of ophiolite sequence nor to the stratiform mafic-ultramafic intrusion. The location of the Taftafan complex along a major fracture zone parallel to the suture between Jeddah and Asir terranes in addition to the aforementioned striking similarities to the Alaskan-type complexes, suggests a formation in subduction-related setting from a common hydrous mafic magma.

  12. COMPARING SEA LEVEL RESPONSE AT MONTEREY, CALIFORNIA FROM THE 1989 LOMA PRIETA EARTHQUAKE AND THE 1964 GREAT ALASKAN EARTHQUAKE

    Directory of Open Access Journals (Sweden)

    L. C. Breaker

    2009-01-01

    Full Text Available Two of the largest earthquakes to affect water levels in Monterey Bay in recent years were the Loma Prieta Earthquake (LPE of 1989 with a moment magnitude of 6.9, and the Great Alaskan Earthquake (GAE of 1964 with a moment magnitude of 9.2. In this study, we compare the sea level response of these events with a primary focus on their frequency content and how the bay affected it, itself. Singular Spectrum Analysis (SSA was employed to extract the primary frequencies associated with each event. It is not clear how or exactly where the tsunami associated with the LPE was generated, but it occurred inside the bay and most likely began to take on the characteristics of a seiche by the time it reached the tide gauge in Monterey Harbor. Results of the SSA decomposition revealed two primary periods of oscillation, 9-10 minutes, and 31-32 minutes. The first oscillation is in agreement with the range of periods for the expected natural oscillations of Monterey Harbor, and the second oscillation is consistent with a bay-wide oscillation or seiche mode. SSA decomposition of the GAE revealed several sequences of oscillations all with a period of approximately 37 minutes, which corresponds to the predicted, and previously observed, transverse mode of oscillation for Monterey Bay. In this case, it appears that this tsunami produced quarter-wave resonance within the bay consistent with its seiche-like response. Overall, the sea level responses to the LPE and GAE differed greatly, not only because of the large difference in their magnitudes but also because the driving force in one case occurred inside the bay (LPE, and in the second, outside the bay (GAE. As a result, different modes of oscillation were excited.

  13. Copper in the sea: a physical--chemical study of reservoirs, fluxes, and pathways in an Alaskan fjord

    Energy Technology Data Exchange (ETDEWEB)

    Heggie, D.T.

    1978-05-01

    Copper in the sea is derived principally from continental weathered products added to the oceans at continental boundaries; hence processes, fluxes, and pathways in estuaries control the supply of copper to the marine biosphere. From mass balances, the fluxes, sources, and sinks of copper in an Alaskan fjord were examined by utilizing fjord deep waters as an approximation to a closed chemical system. Copper was measured in the water columns and interstitial waters electroanalytically. Concentrations of soluble copper ranged between 0.14 ..mu..g l/sup -1/ and 3.13 ..mu..g l/sup -1/. Approximately 40% of total copper was associated with particulate matter in the water column. Concentrations of copper in interstitial waters varied between 1.02 and 9.98 ..mu..g l/sup -1/; maximum concentrations were always found in surface segments. Concentrations of copper on sediments were about 20 mg kg /sup -1/. Copper was removed from the water column and transported to the sediments by particulate matter; net annual removal was estimated to be between 9.6 and 14.2 ..mu..g Cu cm/sup -2/. Copper was remobilized from the solid phase(s) in surface sediments and subsequently returned to the overlying water; net annual transport across the sediment-seawater interface was estimated to be 1.9 ..mu..g Cu cm/sup -/2. Therefore, between 13 and 20% of copper removed from the water column to the sediments was returned to the water column. Remobilized copper not returned to the water column was removed from interstitial waters in the anoxic zone of sediments. Remobilization and removal processes in sediments take place in thin approx. 10 cm zone and effective rates of reactions in sediments may be one of three orders of magnitude greater than reaction rates in the water column. A hypothesis is presented for transport of copper to the sediments predominately on biogenic particles.

  14. Modeling impacts of changes in temperature and water table on C gas fluxes in an Alaskan peatland

    Science.gov (United States)

    Deng, Jia; Li, Changsheng; Frolking, Steve

    2015-07-01

    Northern peatlands have accumulated a large amount of organic carbon (C) in their thick peat profile. Climate change and associated variations in soil environments are expected to have significant impacts on the C balance of these ecosystems, but the magnitude is still highly uncertain. Verifying and understanding the influences of changes in environmental factors on C gas fluxes in biogeochemical models are essential for forecasting feedbacks between C gas fluxes and climate change. In this study, we applied a biogeochemical model, DeNitrification-DeComposition (DNDC), to assess impacts of air temperature (TA) and water table (WT) on C gas fluxes in an Alaskan peatland. DNDC was validated against field measurements of net ecosystem exchange of CO2 (NEE) and CH4 fluxes under manipulated surface soil temperature and WT conditions in a moderate rich fen. The validation demonstrates that DNDC was able to capture the observed impacts of the manipulations in soil environments on C gas fluxes. To investigate responses of C gas fluxes to changes in TA and soil water condition, we conducted a series of simulations with varying TA and WT. The results demonstrate that (1) uptake rates of CO2 at the site were reduced by either too colder or warmer temperatures and generally increased with increasing soil moisture; (2) CH4 emissions showed an increasing trend as TA increased or WT rose toward the peat surface; and (3) the site could shift from a net greenhouse gas (GHG) sink into a net GHG source under some warm and/or dry conditions. A sensitivity analysis evaluated the relative importance of TA and WT to C gas fluxes. The results indicate that both TA and WT played important roles in regulating NEE and CH4 emissions and that within the investigated ranges of the variations in TA and WT, changes in WT showed a greater impact than changes in TA on NEE, CH4 fluxes, and net C gas fluxes at the study fen.

  15. Annual patterns and budget of CO2 flux in an Alaskan arctic tussock tundra ecosystem at Atqasuk, Alaska

    Science.gov (United States)

    Oechel, W. C.; Kalhori, A. A.; Burba, G. G.; Gioli, B.

    2013-12-01

    Arctic ecosystem functioning is not only critically affected by climate change, but also has the potential for major positive feedbacks on climate. There is however relatively little information available on the role, patterns, and vulnerabilities of CO2 fluxes during the non-summer seasons. Presented here is a year-around study of CO2 fluxes in an Alaskan Arctic tussock tundra ecosystem. Also presented are key environmental controls on CO2 fluxes as well as possible impacts of likely changes in season timing. This is aided by a new empirical quantification of seasons in the Arctic based on net radiation, which can help describe seasonal responses to greenhouse gas fluxes under climate change. The fluxes were computed using standard FluxNet methodology and corrected using standard WPL density terms, adjusted for influences of instrument surface heating. The results showed that the non-summer season comprises a significant source of carbon to the atmosphere. The summer period was a net sink of 10.83 g C m-2 yr-1, while the non-summer seasons released more than four times the CO2 uptake observed in the summer, resulting in a net annual source of 37.6 g C m-2 yr-1 to the atmosphere. This shows a change in this region of the Arctic from a long-term annual sink of CO2 from the atmosphere to an annual source of CO2 from the terrestrial ecosystem and soils to the atmosphere. The results presented here demonstrate that nearly continuous observations may be required in order to accurately calculate the annual NEE of Arctic ecosystems, and to build predictive understanding that can be used to estimate, with confidence, Arctic fluxes under future conditions. Daily CO2 fluxes over the year, average daily net radiation, average daily PAR, average daily air temperature and average daily soil respiration (at -5 cm).

  16. Trace Elements in Sea Ducks of the Alaskan Arctic Coast: Patterns of Variation Among Species, Sexes, and Ages.

    Science.gov (United States)

    Miller, Micah W C; Lovvorn, James R; Matz, Angela C; Taylor, Robert J; Latty, Christopher J; Safine, David E

    2016-10-01

    Climate change and increasing industrialization in the Arctic call for the collection of reference data for assessing changes in contaminant levels. For migratory birds, measuring and interpreting changes in trace element burdens on Arctic breeding areas require insights into factors such as sex, body size, or wintering area that may modify patterns independently of local exposure. In the Alaskan Arctic, we determined levels of trace elements in liver and kidney of common eiders (Somateria mollissima) and long-tailed ducks (Clangula hyemalis) from the Prudhoe Bay oil field and of king eiders (S. spectabilis) and threatened spectacled eiders (S. fischeri) and Steller's eiders (Polystica stelleri) from near the town of Barrow. Small-bodied Steller's eiders and long-tailed ducks from different locations had similarly low levels of selenium (Se), cadmium (Cd), and copper (Cu), perhaps reflecting high mass-specific rates of metabolic depuration during long spring migrations through areas of low exposure. In larger species, Se, Cd, and Cu concentrations were higher in adults than juveniles suggesting that these elements were acquired in nonbreeding marine habitats. Adult male spectacled eiders had exceptionally high Se, Cd, and Cu compared with adult females, possibly because of depuration into eggs and longer female occupancy of nonmarine habitats. Adult female common eiders and juvenile long-tailed ducks at Prudhoe Bay had high and variable levels of Pb, potentially due to local exposure. Explanations for substantial variations in Hg levels were not apparent. Further research into reasons for differing element levels among species and sexes will help clarify the sources, pathways, and risks of exposure.

  17. Seasonal hydrology drives rapid shifts in the flux and composition of dissolved and particulate organic carbon and major and trace ions in the Fraser River, Canada

    Science.gov (United States)

    Voss, B. M.; Peucker-Ehrenbrink, B.; Eglinton, T. I.; Spencer, R. G. M.; Bulygina, E.; Galy, V.; Lamborg, C. H.; Ganguli, P. M.; Montluçon, D. B.; Marsh, S.; Gillies, S. L.; Fanslau, J.; Epp, A.; Luymes, R.

    2015-10-01

    Rapid changes in the volume and sources of discharge during the spring freshet lead to pronounced variations in biogeochemical properties in snowmelt-dominated river basins. We used daily sampling during the onset of the freshet in the Fraser River (southwestern Canada) in 2013 to identify rapid changes in the flux and composition of dissolved material, with a focus on dissolved organic matter (DOM). Previous time series sampling (at twice monthly frequency) of dissolved inorganic species in the Fraser River has revealed smooth seasonal transitions in concentrations of major ions and tracers of water and dissolved load sources between freshet and base flow periods. In contrast, daily sampling reveals a significant increase in dissolved organic carbon (DOC) concentration (200 to 550 μmol L-1) occurring over a matter of days, accompanied by a shift in DOM optical properties, indicating a transition towards higher molecular weight, more aromatic DOM composition. Comparable changes in DOM composition, but not concentration, occur at other times of year, underscoring the role of seasonal climatology in DOM cycling. A smaller data set of total and dissolved Hg concentrations also showed variability during the spring freshet period, although dissolved Hg dynamics appear to be driven by factors beyond DOM as characterized here. The time series records of DOC and particulate organic carbon (POC) concentrations indicate that the Fraser River exports 0.25-0.35 % of its annual basin net primary productivity. The snowmelt-dominated hydrology, forested land cover, and minimal reservoir impoundment of the Fraser River may influence the DOC yield of the basin, which is high relative to the nearby Columbia River and of similar magnitude to that of the Yukon River to the north. Anticipated warming and decreased snowfall due to climate changes in the region may cause an overall decrease in DOM flux from the Fraser River to the coastal ocean in coming decades

  18. Paleopole for the 69 Ma Prospector Mountain Stock: A critique of the Carmacks/"Baja BC" transport estimate for Yukon, Canada

    Science.gov (United States)

    Symons, D. T. A.; Kawasaki, K.; McCausland, P. J. A.; Hart, C. J. R.

    2016-10-01

    The 69 Ma Prospector Mountain stock is located in southwestern Yukon in the northern Canadian Cordillera. This massive monzonite-syenogranite stock is thought to be the intrusive volcanic center for the surrounding coeval Carmacks Group volcanics. Anomalous paleomagnetic data from these volcanics have provided the only evidence for the commonly posited hypothesis that the Yukon-Tanana terrane (YTT) was part of the far-travelled (1950 ± 600 km northward) "Baja BC" terrane from 70 to 50 Ma. All other geologic evidence and averaged paleomagnetic data support a northward displacement of ˜415 ± 15 km. This study provides a direct test of the Carmacks volcanics' estimate and examines the possible causes of its anomalous results. Both the stock and volcanics are unmetamorphosed and rest unconformably on metamorphosed basement rocks of the YTT. Paleomagnetic and mineral magnetic results from 17 of 19 tested sites (218 specimens) in the Prospector stock and its peripheral skarn isolated a stable thermoremanent magnetization (TRM) in magnetite or low-Ti titanomagnetite that was mostly determined on demagnetization between temperatures of 500° and 580°C. The TRM has a direction of Decl. = 8.3°, Incl. = 82.4° (N = 17, k = 71.9, α95 = 4.2°), providing a nonsignificant northwards translation estimate of 70 ± 880 km for the YTT. The normal-polarity TRM direction at Prospector Mountain provides a highly significant paleomagnetic reversals test with the reversed-polarity TRM of the 70 Ma Swede Dome stock, another volcanic center of the Carmacks Group about 190 km to the north. The test affirms to a high probability that both stocks carry primary TRMs and have not been tectonically tilted significantly since emplacement. Combining the paleopoles for these two stocks with that for the 75 Ma Mount Lorne volcanic center stock about 210 km south of Prospector Mountain yields a combined northward translation estimate of 330 ± 400 km for the YTT since ˜71 Ma. This estimate

  19. Palaeopole for the 69 Ma Prospector Mountain stock: a critique of the Carmacks/`Baja BC' transport estimate for Yukon, Canada

    Science.gov (United States)

    Symons, D. T. A.; Kawasaki, K.; McCausland, P. J. A.; Hart, C. J. R.

    2017-01-01

    The 69 Ma Prospector Mountain stock is located in southwestern Yukon in the northern Canadian Cordillera. This massive monzonite-syenogranite stock is thought to be the intrusive volcanic centre for the surrounding coeval Carmacks Group volcanics. Anomalous palaeomagnetic data from these volcanics have provided the only evidence for the commonly posited hypothesis that the Yukon-Tanana terrane (YTT) was part of the far-travelled (1950 ± 600 km northward) `Baja BC' terrane from 70 to 50 Ma. All other geologic evidence and averaged palaeomagnetic data support a northward displacement of ˜415 ± 15 km. This study provides a direct test of the Carmacks volcanics' estimate and examines the possible causes of its anomalous results. Both the stock and volcanics are unmetamorphosed and rest unconformably on metamorphosed basement rocks of the YTT. Palaeomagnetic and mineral magnetic results from 17 of 19 tested sites (218 specimens) in the Prospector stock and its peripheral skarn isolated a stable thermoremanent magnetization (TRM) in magnetite or low-Ti titanomagnetite that was mostly determined on demagnetization between temperatures of 500 and 580 °C. The TRM has a direction of Decl. = 8.3°, Incl. = 82.4° (N = 17, k = 71.9, α95 = 4.2°), providing a non-significant northwards translation estimate of 70 ± 880 km for the YTT. The normal-polarity TRM direction at Prospector Mountain provides a highly significant palaeomagnetic reversals test with the reversed-polarity TRM of the 70 Ma Swede Dome stock, another volcanic centre of the Carmacks Group about 190 km to the north. The test affirms to a high probability that both stocks carry primary TRMs and have not been tectonically tilted significantly since emplacement. Combining the palaeopoles for these two stocks with that for the 75 Ma Mount Lorne volcanic centre stock about 210 km south of Prospector Mountain yields a combined northward translation estimate of 330 ± 400 km for the YTT since ˜71 Ma. This

  20. Geochemistry of host rocks in the Howards Pass district, Yukon-Northwest Territories, Canada: implications for sedimentary environments of Zn-Pb and phosphate mineralization

    Science.gov (United States)

    Slack, John F.; Falck, Hendrik; Kelley, Karen D.; Xue, Gabriel G.

    2016-10-01

    Detailed lithogeochemical data are reported here on early Paleozoic sedimentary rocks that host the large Howards Pass stratiform Zn-Pb deposits in Yukon-Northwest Territories. Redox-sensitive trace elements (Mo, Re, V, U) and Ce anomalies in members of the Duo Lake Formation record significant environmental changes. During the deposition of lower footwall units (Pyritic siliceous and Calcareous mudstone members), bottom waters were anoxic and sulphidic, respectively; these members formed in a marginal basin that may have become increasingly restricted with time. Relative to lower members, a major environmental change is proposed for deposition of the overlying Lower cherty mudstone member, which contains phosphorite beds up to ˜0.8 m thick in the upper part, near the base of the Zn-Pb deposits. The presence of these beds, together with models for modern phosphorite formation, suggests P input from an upwelling system and phosphorite deposition in an upper slope or outer shelf setting. The overlying Active mudstone member contains stratabound to stratiform Zn-Pb deposits within black mudstone and gray calcareous mudstone. Data for unmineralized black mudstone in this member indicate deposition under diverse redox conditions from suboxic to sulphidic. Especially distinctive in this member are uniformly low ratios of light to heavy rare earth elements that are unique within the Duo Lake Formation, attributed here to the dissolution of sedimentary apatite by downward-percolating acidic metalliferous brines. Strata that overlie the Active member (Upper siliceous mudstone member) consist mainly of black mudstone with thin (0.5-1.5 cm) laminae of fine-grained apatite, recording continued deposition on an upper slope or outer shelf under predominantly suboxic bottom waters. Results of this study suggest that exploration for similar stratiform sediment-hosted Zn-Pb deposits should include the outer parts of ancient continental margins, especially at and near stratigraphic

  1. Geochemistry of host rocks in the Howards Pass district, Yukon-Northwest Territories, Canada: implications for sedimentary environments of Zn-Pb and phosphate mineralization

    Science.gov (United States)

    Slack, John F.; Falck, Hendrik; Kelley, Karen D.; Xue, Gabriel G.

    2017-01-01

    Detailed lithogeochemical data are reported here on early Paleozoic sedimentary rocks that host the large Howards Pass stratiform Zn-Pb deposits in Yukon-Northwest Territories. Redox-sensitive trace elements (Mo, Re, V, U) and Ce anomalies in members of the Duo Lake Formation record significant environmental changes. During the deposition of lower footwall units (Pyritic siliceous and Calcareous mudstone members), bottom waters were anoxic and sulphidic, respectively; these members formed in a marginal basin that may have become increasingly restricted with time. Relative to lower members, a major environmental change is proposed for deposition of the overlying Lower cherty mudstone member, which contains phosphorite beds up to ∼0.8 m thick in the upper part, near the base of the Zn-Pb deposits. The presence of these beds, together with models for modern phosphorite formation, suggests P input from an upwelling system and phosphorite deposition in an upper slope or outer shelf setting. The overlying Active mudstone member contains stratabound to stratiform Zn-Pb deposits within black mudstone and gray calcareous mudstone. Data for unmineralized black mudstone in this member indicate deposition under diverse redox conditions from suboxic to sulphidic. Especially distinctive in this member are uniformly low ratios of light to heavy rare earth elements that are unique within the Duo Lake Formation, attributed here to the dissolution of sedimentary apatite by downward-percolating acidic metalliferous brines. Strata that overlie the Active member (Upper siliceous mudstone member) consist mainly of black mudstone with thin (0.5–1.5 cm) laminae of fine-grained apatite, recording continued deposition on an upper slope or outer shelf under predominantly suboxic bottom waters. Results of this study suggest that exploration for similar stratiform sediment-hosted Zn-Pb deposits should include the outer parts of ancient continental margins, especially at and near

  2. A 1750-1999 AD Atmospheric Record of East Asian Black Carbon Emissions from the Prospector-Russell Col Ice Core, Mt. Logan, Yukon Territory

    Science.gov (United States)

    Menking, J. A.; Kaspari, S.; Osterberg, E. C.; Fisher, D.

    2012-12-01

    Black carbon (BC), an aerosol created from the incomplete combustion of fossil and biofuels, absorbs sunlight causing warming in the atmosphere and cooling at the surface. BC deposited on snow and ice reduces the surface albedo, accelerating seasonal snowmelt and glacier retreat and influencing the regional water cycle and climate. Estimates place East Asia as the top BC producer worldwide. Recent studies suggest that increases in East Asian BC related to industrialization have influenced Asian climate by altering temperatures and the timing and magnitude of precipitation. East Asian BC emissions have been estimated using fossil fuel inventories, but observational data is needed to constrain the timing and magnitude of recent BC emissions changes in order to better assess the role of BC in recent climate change. Here we present a time series of East Asian atmospheric BC that spans 1750-1999 AD that was developed using an ice core collected at the Prospector-Russell (PR) Col on Mt. Logan, Yukon Territory, Canada. The PR Col ice core is ideal for developing a record of East Asian BC emissions because the Mt. Logan summit has been shown to capture Asian emissions transported across the Pacific Ocean. The Mt. Logan record shows increases in BC concentration occurring in the early 1980's related to the recent industrialization of East Asian nations. We utilize the BC record from Mt. Logan (1) for comparison with estimated East Asian emissions inventories, and (2) to assess the role of BC in recent climate change with respect to the timing and magnitude of changes in East Asian BC emissions.

  3. Scenario-based climate change modelling for a regional permafrost probability model of the southern Yukon and northern British Columbia, Canada

    Directory of Open Access Journals (Sweden)

    P. P. Bonnaventure

    2012-10-01

    Full Text Available Scenario-based climate change modelling for equilibrium conditions was applied to a Regional Model of permafrost probability for the southern Yukon and northwestern British Columbia. Under a −1 K cooling scenario, permafrost area expands from 58% (present day of the 490 000 km2 to 76%, whereas warming scenarios of +1 K, +2 K and +5 K decrease the terrain underlain by permafrost to 38%, 24% and 9% respectively. The morphology of permafrost gain/loss under these scenarios is controlled by the Surface Lapse Rate (SLR, which varies across the region below and above treeline. The SLR is an air temperature elevation gradient that that is noticeably different across the study region. As a result of this attribute three distinct patterns of loss morphology can be identified. Areas that are more maritime exhibit SLRs characteristically similar above and below treeline resulting in low probabilities of permafrost in valley bottoms. Consequently, a loss front moves to upper elevations when warming scenarios are applied (Simple Unidirectional Spatial Loss. Areas where SLRs are gentle below treeline (but normal/negative and normal above treeline show lower permafrost probabilities with a loss front moving up mountain according to two separate SLRs (Complex Unidirectional Spatial Loss. Finally areas that display high continentally exhibit Bidirectional Spatial Loss where the loss front of lower permafrost probabilities moves up mountain above treeline and down mountain below treeline. Areas that are most affected by permafrost loss are zones with SLRs close to 0 K km−1 where permafrost is extensive, whereas the least susceptible areas to changes in MAAT are above treeline and are highly elevation dependent.

  4. River Morphology and River Channel Changes

    Institute of Scientific and Technical Information of China (English)

    CHANG Howard H

    2008-01-01

    River morphology has been a subject of great challenge to scientists and engineers who recognize that any effort with regard to river engineering must be based on a proper understanding of the morphological features involved and the responses to the imposed changes. In this paper,an overview of river morphology is presented from the geomorphic viewpoint. Included in the scope are the regime concept, river channel classification, thresholds in river morphology, and geomor-phic analysis of river responses. Analytical approach to river morphology based on the physical principles for the hydraulics of flow and sediment transport processes is also presented. The appli-cation of analytical river morphology is demonstrated by an example. Modeling is the modern tech-nique to determine both short-term and long-term river channel responses to any change in the en-vironment. The physical foundation of fluvial process-response must be applied in formatting a mathematical model. A brief introduction of the mathematical model FLUVIAL-12 is described.

  5. An Intercomparison of Semi-Eulerian and Lagrangian Based Cyclone Tracking Methods for the North Pacific and Alaskan Regions

    Science.gov (United States)

    Shippee, N. J.; Atkinson, D. E.

    2014-12-01

    The idea of considering the "end user perspective" regarding storm activity and objective tracking methods used to compile information on their behaviour is particularly important in the Alaskan region. Annually, coastal regions in the North are exposed to stormy conditions, though most impacts occur during periods where multiple storms track over the same area in a short period of time (serial cyclones) or where strong storms occur without the presence of a protective sea ice buffer. From a fixed perspective (i.e. Eulerian), a storm may be identified more by the impacts that it generates at that location (winds, sea state, erosion). From a Lagrangian (tracking) view, the intensity, duration, and characteristics of the synoptic environment may prove more relevant for understanding. The overall "effectiveness" of an objective tracking method depends on the intended use of the provided information. While pitting different methods against each other is not necessarily a fruitful exercise (Mesquita et al. 2009), the reality is that one method may better reflect the reality of storm activity and impacts to those experiencing the weather first hand. One of the more subtle points in extra-tropical cyclone tracking and comparison work is the method by which a storm is defined. Most cyclones are analyzed on MSLP fields; others define a cyclone by relative vorticity (ζ) maxima at 850 hPa (NH) and minima (SH). Storms can also be defined by wind events, or even impacts, at a location. Using counts of strong wind events at a grid point or location can account for pressure gradients both associated with storms and absent of a synoptic event. Three separate tracking algorithms are analyzed to determine the method most likely to produce a long-term homogeneous dataset that can be used to train a statistical seasonal prediction method. These methods include the Serreze algorithm, Hodges TRACK algorithm, and Atkinson algorithm. Both the Serreze and Hodges methods provide a tracking

  6. Remarkable isotopic and trace element trends in potassic through sodic Cretaceous plutons of the Yukon-Koyukuk Basin, Alaska, and the nature of the lithosphere beneath the Koyukuk terrane

    Science.gov (United States)

    Arth, Joseph G.; Criss, Robert E.; Zmuda, Clara C.; Foley, Nora K.; Patton, W. W., Jr.; Miller, T. P.

    1989-11-01

    During the period from 110 to 80 m.y. ago, a 450-km-long magmatic belt was active along the northern margin of Yukon-Koyukuk basin and on eastern Seward Peninsula. The plutons intruded Upper Jurassic(?) and Lower Cretaceous volcanic arc rocks and Cretaceous sedimentary rocks in Yukon-Koyukuk basin and Proterozoic and lower Paleozoic continental rocks in Seward Peninsula. Within Yukon-Koyukuk basin, the plutons vary in composition from calc-alkalic plutons on the east to potassic and ultrapotassic alkalic plutons on the west. Plutons within Yukon-Koyukuk basin were analyzed for trace element and isotopic compositions in order to discern their origin and the nature of the underling lithosphere. Farthest to the east, the calc-alkalic rocks of Indian Mountain pluton are largely tonalite and sodic granodiorite, and have low Rb (average 82 ppm), high Sr (>600 ppm), high chondrite-normalized (cn) Ce/Yb (16-37), low δ18O (+6.5 to +7.1), low initial 87Sr/86Sr (SIR) (0.704), and high initial 143Nd/144Nd (NIR) (0.5126). These rocks resemble those modelled elsewhere as partial melts and subsequent fractionates of basaltic or gabbroic metaigneous rocks, and may be products of melting in the deeper parts of the Late Jurassic(?) and Early Cretaceous volcanic arc. Farthest to the west, the two ultrapotassic bodies of Selawik and Inland Lake are high in Cs (up to 93 ppm), Rb (up to 997 ppm), Sr, Ba, Th, and light rare earth elements, have high (Ce/Yb)cn (30, 27), moderate to low δ18O (+8.4, +6.9), high SIR (0.712, 0.710), and moderate NIR (0.5121-0.5122). These rocks resemble rocks of Australia and elsewhere that were modelled as melts of continental mantle that had been previously enriched in large cations. This mantle may be Paleozoic or older. The farthest west alkalic pluton of Selawik Hills is largely monzonite, quartz monzonite, and granite; has moderate Rb (average 284 ppm), high Sr (>600 ppm), high (Ce/Yb)cn (15-25), moderate δ18O (+8.3 to +8.6), high SIR (0

  7. Iowa's Sovereign Meandered Rivers

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This data set depicts Iowa's Meandered Rivers. These rivers are deemed sovereign land & therefore require any person wishing to conduct construction activities...

  8. Allegheny County Major Rivers

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset contains locations of major rivers that flow through Allegheny County. These shapes have been taken from the Hydrology dataset. The Ohio River,...

  9. Illinois River NWFR HMP

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Illinois River National Wildlife and Fish Refuges Complex stretches along 124 miles of the Illinois River in west central Illinois. The Complex includes three...

  10. Qingjiang River Developer

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    THE 400-kilometer Qingjiang River, second tributary of the Yangtze River in Hubei Province, has a drainage area of 17,000 square kilometers. Its advantageous natural conditions have made it a key water power development project.

  11. Changes in Terrestrial Organic Carbon Delivery to the Colville River Delta and Adjacent Simpson's Lagoon Over the Late Holocene

    Science.gov (United States)

    Schreiner, K. M.; Bianchi, T. S.; Allison, M. A.; Miller, A. J.; Marcantonio, F.

    2012-04-01

    The Colville River in Alaska is the largest river in North America that drains only continuously permafrosted tundra, and as such provides a unique signal of historical changes in one of the world's most vulnerable areas to climate changes. Additionally, the Colville flows into Simpson's Lagoon, a shallow area of the Alaskan Beaufort coast protected by a barrier island chain, lessening the impacts of Arctic storms and ice grounding on sediment mixing. Cores collected from the Colville river delta in August of 2010 were found to be composed of muddy, organic-rich, well-laminated sediments. The 2.5 to 3 meter length of each core spans about one to two thousand years of Holocene history, including the entire Anthropocene and much of the late Holocene. Three cores were sampled for this data set, arranged latitudinally from the mouth of the Colville River east into Simpson's Lagoon. Samples were taken every 2 cm for the entire length of all cores. Bulk analyses including percent organic carbon, percent nitrogen, and stable carbon isotopic analysis were performed, and compound specific analyses including lignin-phenol and algal pigment analyses were performed. These analyses showed significant changes in carbon storage over the past one to two thousand years. There were also significant spatial differences in organic carbon inputs across the ~20km distance between the Colville mouth and the easternmost core. Lignin-phenol concentrations in surface sediments nearest to the river mouth correlated positively with reconstructed Alaskan North Slope temperatures, suggesting more terrestrial organic matter was delivered during higher temperature regimes. Molar C:N ratios and plant pigments correlated negatively and positively, respectively, with reconstructed Alaskan North Slope moisture regime, indicating greater algal inputs during wetter time periods. These data may in part be consistent with observed woody shrub encroachment and increasing expanse of permafrost lakes on the

  12. Measuring River Pollution

    Science.gov (United States)

    Ayyavoo, Gabriel

    2004-01-01

    The Don River watershed is located within Canada's most highly urbanized area--metropolitan Toronto. Many residential and commercial uses, including alterations to the river's course with bridges, have had a significant impact on the Don's fauna and flora. Pollutants have degraded the river's water quality, a situation exacerbated by the…

  13. The world-class Howard's Pass SEDEX Zn-Pb district, Selwyn Basin, Yukon. Part II: the roles of thermochemical and bacterial sulfate reduction in metal fixation

    Science.gov (United States)

    Gadd, Michael G.; Layton-Matthews, Daniel; Peter, Jan M.; Paradis, Suzanne; Jonasson, Ian R.

    2016-07-01

    The Howard's Pass district of sedimentary exhalative (SEDEX) Zn-Pb deposits is located in Yukon Territory and comprises 14 Zn-Pb deposits that contain an estimated 400.7 Mt of sulfide mineralization grading 4.5 % Zn and 1.5 % Pb. Mineralization is hosted in carbonaceous and calcareous and, to a lesser extent, siliceous mudstones. Pyrite is a minor but ubiquitous mineral in the host rocks stratigraphically above, within, and below mineralization. Petrographic analyses reveal that pyrite has a complex and protracted growth history, preserving multiple generations of pyrite within single grains. Sulfur isotope analysis of paragenetically complex pyrite by secondary ion mass spectrometry (SIMS) reveals that sulfur isotope compositions vary with textural zonation. Within the Zn-Pb deposits, framboidal pyrite is the earliest pyrite generation recognized, and this exclusively has negative δ34S values (mean = -16.6 ± 4.1 ‰; n = 55), whereas paragenetically later pyrite and galena possess positive δ34S values (mean = 29.1 ± 7.5 and 22.4 ± 3.0 ‰, n = 13 and 13, respectively). Previous studies found that sphalerite and galena mineral separates have exclusively positive δ34S values (mean = 16.8 ± 3.3 and 12.7 ± 2.8 ‰, respectively; Goodfellow and Jonasson 1986). These distinct sulfur isotope values are interpreted to reflect varying contributions of bacterially reduced seawater sulfate (negative; framboidal pyrite) and thermochemically reduced seawater sulfate and/or hydrothermal sulfate (positive; galena, sphalerite, later forms of pyrite). Textural evidence indicates that framboidal pyrite predates galena and sphalerite deposition. Collectively, the in situ and bulk sulfur isotope data are much more complex than δ34S values permitted by prevailing genetic models that invoke only biogenically reduced sulfur and coeval deposition of galena, sphalerite, and framboidal pyrite within a euxinic water column, and we present several lines of evidence that argue

  14. Substrate Geochemistry and Soil Development in Boreal Forest and Tundra Ecosystems in the Yukon-Tanana Upland and Seward Peninsula, Alaska

    Science.gov (United States)

    Gough, L.P.; Crock, J.G.; Wang, B.; Day, W.C.; Eberl, D.D.; Sanzolone, R.F.; Lamothe, P.J.

    2008-01-01

    We report on soil development as a function of bedrock type and the presence of loess in two high latitude ecosystems (boreal forest and tundra) and from two regions in Alaska?the Yukon-Tanana Upland (YTU, east-central Alaska) and the Seward Peninsula (SP, far-west coastal Alaska). This approach to the study of 'cold soils' is fundamental to the quantification of regional geochemical landscape patterns. Of the five state factors in this study, bedrock and biota (ecosystem; vegetation zone) vary whereas climate (within each area) and topography are controlled. The influence of time is assumed to be controlled, as these soils are thousands of years old (late Quaternary to Holocene). The primary minerals in soils from YTU, developed over loess and crystalline bedrock (metamorphic and intrusive), are quartz, plagioclase, and 2:1 clays; whereas in the SP, where loess and metasedimentary bedrock (schist and quartzite) predominate, they are quartz and muscovite. The A horizon of both regions is rich in peat. Examination of the ratio of mobile (K2O, CaO, and Fe2O3) to immobile (TiO2) major oxides, within each region, shows that very little difference exists in the chemical weathering of soils developed between the two ecosystems examined. Differences were observed between tundra soils developed in the two regions. These differences are most probably due to the dissimilarity in the geochemical importance of both loess and bedrock. A minimal loss of cadmium with soil depth is seen for soils developed over YTU crystalline bedrock in the boreal forest environments. This trend is related to the mobility of cadmium in these soils as well as to its biogenic cycling. Major differences were observed in the proportion of cadmium and zinc among the A, B, and C horizon material sequestered in various soil fractions as measured by sequential soil extractions. These trends followed such variables as the decrease with depth in organic matter, the change in clay minerals, and the change

  15. Biotic interactions in temporal trends (1992–2010) of organochlorine contaminants in the aquatic food web of Lake Laberge, Yukon Territory

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, M.J. [Fisheries and Oceans Canada, Freshwater Institute, 501 University Crescent, Winnipeg, Manitoba, Canada R3T 2N6 (Canada); University of Manitoba, Dept. of Soil Science, Winnipeg, Manitoba, Canada R3T 2N2 (Canada); Stern, G.A., E-mail: gary.stern@dfo-mpo.gc.ca [Fisheries and Oceans Canada, Freshwater Institute, 501 University Crescent, Winnipeg, Manitoba, Canada R3T 2N6 (Canada); Kidd, K.A. [University of New Brunswick, Canadian Rivers Institute and Department of Biology, Saint John, New Brunswick, Canada E2L 4E5 (Canada); Croft, M.V. [Fisheries and Oceans Canada, Freshwater Institute, 501 University Crescent, Winnipeg, Manitoba, Canada R3T 2N6 (Canada); Gewurtz, S.; Diamond, M. [University of Toronto, Department of Geography, Toronto, Ontario, Canada M5S 3G3 (Canada); Kinnear, L. [Northern Climate Exchange, Yukon Research Center, Yukon College, Whitehorse, Yukon Territory, Canada Y1A 5K4 (Canada); Roach, P. [Aboriginal Affairs and Northern Development Canada, Rm 415C - 300 Main St., Whitehorse, Yukon Territory, Canada Y1A 2B5 (Canada)

    2013-01-15

    Declines in 6 organochlorine (OC) contaminant groups; chlordane (CHL), DDT, HCH, toxaphene (CHB), PCB and chlorinated benzenes (CBz) were measured in biota of a sub-Arctic lake (Lake Laberge, YT) following the closure of a commercial fishery in 1991. This study examined morphological (length, weight, age), biochemical (lipid content, δ{sup 13}C, δ{sup 15}N), population and OC data for 9 fishes and zooplankton between 1993 and 2003 (2010 for lake trout) to investigate causes for the OC declines. Growth dilution was a major factor influencing the decrease of OCs in lake trout, round whitefish and possibly zooplankton most notably in the early 2000s. A decline in lipids of most fish species also contributed to OC declines, although no such change was evident for zooplankton. It is suspected that increases in fish populations or climate variations over the 1990s, may have contributed towards a shift in plankton community composition. From 1991 to 1999, CPUE increased for 7 of the fish species and declined for 2 others. Concurrently, the zooplankton community shifted from an abundance of C. scutifer in 1993 to dominance by D. pribilofensis in 2001. Nitrogen and carbon stable isotope data suggested that food web interactions for most fish species have not changed over time. Although concentrations of OCs have declined in many fishes, the “rate” of OC transfer (using slopes of log OC vs. nitrogen isotope ratios) through the food web was greater in 2001 than in 1993. Overall, the declines in OC concentrations in the fish from Lake Laberge occurred concurrently with changes in their growth, lipid, and abundance, suggesting that ecosystem responses to the closure of the fishery were in part responsible for the lower contaminants in these fishes. As a result of this study, the Yukon government rescinded the health advisory for limiting the consumption of fish from Lake Laberge. - Highlights: ► Organochlorine contaminants in a sub-Arctic lake were monitored post

  16. Cenozoic evolution of the Yakutat-North American collision zone and structural accommodation of St. Elias syntaxis exhumation, Alaska/Yukon

    Science.gov (United States)

    Falkowski, Sarah; Enkelmann, Eva; Ehlers, Todd

    2016-04-01

    Active convergent margins potentially pose multiple natural hazards to human life and infrastructure. Tectonic strain may be further focused where convergent margins are warped into broad syntaxes. However, the processes responsible for upper plate deformation in these settings are not well understood. The St. Elias syntaxis in southeast Alaska and southwest Yukon is located at the eastern corner of the Yakutat microplate, which indents into the North American Plate and subducts at a flat angle beneath Alaska. High rates of long-term glacial erosion and exhumation (>2 mm/yr) are found on the southern, coastal flanks of the St. Elias orogen, but the deepest and most rapid exhumation is focused at the St. Elias syntaxis. In this location, transform motion transitions into subduction of the wedge-shaped, oceanic plateau of the Yakutat microplate. In order to map the spatio-temporal pattern of exhumation in the Yakutat-North American collision zone, we conducted zircon and apatite fission-track analyses of predominantly detrital, sand-sized material and five bedrock samples from 47 different glacio-fluvial catchments covering an area of ~45,000 km2 around the St. Elias syntaxis. Integration of the new thermochronologic data with prior work and other geologic and geophysical observations yielded information on past terrane accretion events at the North American margin since the late Mesozoic and the evolution of exhumation at the St. Elias syntaxis in the context of the ongoing Yakutat-North American plate collision. Our results indicate a migrating focus of the most rapid exhumation from north to south and from the upper (North American Plate) to the lower (Yakutat microplate) plate in the syntaxis area over the past ~10 Myr. This migration occurred in response to a change in plate motions, increasingly thicker crust of the subducting Yakutat microplate, and changes in surface processes after glaciation began that resulted in modification of the rheology. We propose a

  17. The world-class Howard's Pass SEDEX Zn-Pb district, Selwyn Basin, Yukon. Part II: the roles of thermochemical and bacterial sulfate reduction in metal fixation

    Science.gov (United States)

    Gadd, Michael G.; Layton-Matthews, Daniel; Peter, Jan M.; Paradis, Suzanne; Jonasson, Ian R.

    2017-03-01

    The Howard's Pass district of sedimentary exhalative (SEDEX) Zn-Pb deposits is located in Yukon Territory and comprises 14 Zn-Pb deposits that contain an estimated 400.7 Mt of sulfide mineralization grading 4.5 % Zn and 1.5 % Pb. Mineralization is hosted in carbonaceous and calcareous and, to a lesser extent, siliceous mudstones. Pyrite is a minor but ubiquitous mineral in the host rocks stratigraphically above, within, and below mineralization. Petrographic analyses reveal that pyrite has a complex and protracted growth history, preserving multiple generations of pyrite within single grains. Sulfur isotope analysis of paragenetically complex pyrite by secondary ion mass spectrometry (SIMS) reveals that sulfur isotope compositions vary with textural zonation. Within the Zn-Pb deposits, framboidal pyrite is the earliest pyrite generation recognized, and this exclusively has negative δ34S values (mean = -16.6 ± 4.1 ‰; n = 55), whereas paragenetically later pyrite and galena possess positive δ34S values (mean = 29.1 ± 7.5 and 22.4 ± 3.0 ‰, n = 13 and 13, respectively). Previous studies found that sphalerite and galena mineral separates have exclusively positive δ34S values (mean = 16.8 ± 3.3 and 12.7 ± 2.8 ‰, respectively; Goodfellow and Jonasson 1986). These distinct sulfur isotope values are interpreted to reflect varying contributions of bacterially reduced seawater sulfate (negative; framboidal pyrite) and thermochemically reduced seawater sulfate and/or hydrothermal sulfate (positive; galena, sphalerite, later forms of pyrite). Textural evidence indicates that framboidal pyrite predates galena and sphalerite deposition. Collectively, the in situ and bulk sulfur isotope data are much more complex than δ34S values permitted by prevailing genetic models that invoke only biogenically reduced sulfur and coeval deposition of galena, sphalerite, and framboidal pyrite within a euxinic water column, and we present several lines of evidence that argue

  18. Re-Os systematics and age of pyrite associated with stratiform Zn-Pb mineralization in the Howards Pass district, Yukon and Northwest Territories, Canada

    Science.gov (United States)

    Kelley, Karen D.; Selby, David; Falck, Hendrik; Slack, John F.

    2016-05-01

    Stratiform Zn-Pb deposits hosted in unmetamorphosed carbonaceous and siliceous mudstones of the Ordovician to Silurian Duo Lake Formation define the Howards Pass district in Yukon Territory and Northwest Territories, western Canada. Collectively, the deposits are amongst the largest in the world, containing drill-indicated and inferred resources of 423 Mt at 4.84 % Zn and 1.59 % Pb. Sulphide textures include (a) fine-scale laminations of sphalerite, galena, and pyrite from rock; (b) layers of coarse sulphide that are structurally controlled by microfolds; and (c) veins that cut bedding and sulphide laminations. The finely interlaminated nature of sulphides with mudstone has been used as evidence for syngenetic mineralizing processes, whereas paleomagnetic data determined on coarse layered sulphides suggest a Middle Jurassic age of mineralization. Here, we present new rhenium-osmium (Re-Os) isotopic data for 12 pyrite separates obtained from 4 laminated sulphide-rich samples from the XY Central (XYC) and Don (DON) deposits and for 1 unmineralized organic-rich mudstone ˜20 m stratigraphically below the sulphide-bearing zone. Pyrite separates that lack mudstone inclusions ("pure") from the XYC deposit contain 2.2 to 4.0 ppb Re and 93.4 to 123.4 ppt Os; pure pyrite from the DON deposit is significantly more enriched in Re and Os (34-37 ppb Re; 636.8-694.9 ppt Os). The 187Re/188Os values of pure pyrite separates from the XYC and DON deposits range from 137.6 to 197 and 182.1 to 201.4, respectively. Regression of all pure pyrite Re-Os data from both deposits yields an isochron age of 442 ± 14 Ma (MSWD = 7.4) and an initial 187Os/188Os (Osi) value of 0.71 ± 0.07. The Re-Os age indicates that the early phase of pyrite precipitation (and by inference, sphalerite and galena) occurred during the early Silurian, consistent with biostratigraphic ages of the host rocks. The Osi value of ˜0.8 for earliest Silurian seawater recorded from organic-rich shale in the basal

  19. Multi-method geo- and thermochronology of glacially transported cobbles reveals the tectonic and exhumation history of the St. Elias Mountains (Alaska/Yukon)

    Science.gov (United States)

    Falkowski, Sarah; Enkelmann, Eva; Drost, Kerstin; Pfänder, Jörg; Stübner, Konstanze; Ehlers, Todd

    2016-04-01

    Multi-method dating is a powerful tool to understand tectonic processes and mountain building. In the case of inaccessible mountain regions, e.g., due to extensive glaciation, the dating of detrital material and bedrock samples from rare outcrops with geo- and thermochronologic methods is often the only applicable approach to study the timing and rates of tectonic processes. The St. Elias Mountains of southeast Alaska and southwest Yukon are an example of a heavily glaciated orogen. With the help of detrital thermochronology of sand-sized material, exhumation patterns could be mapped, though with a low spatial resolution. In contrast, geo- and thermochronology applied to glacially derived cobbles yields provenance information from cobble lithology, zircon U-Pb dating, and the entire cooling history from multiple mineral phases. Multi-grain and multi-aliquot analyses yield high-precision crystallization and cooling ages, while sand-sized detritus requires analysis of single minerals particularly resistant to weathering. We present a reconstruction of the Cenozoic tectonic and exhumation history of the St. Elias Mountains that was obtained from the analysis of 27 carefully selected and prepared cobble samples taken from two of the largest glacial catchments of the St. Elias Mountains. A total of 21 zircon U-Pb data sets as well as eight amphibole and seven biotite 40Ar/39Ar ages constrain the (maximum) formation and cooling ages, respectively, of the rocks in the source area. In addition, four zircon and six apatite (U-Th)/He ages as well as four apatite fission-track ages reveal the exhumation history of these source rocks. Integration of the cobble results with an additional three bedrock biotite 40Ar/39Ar ages and published geo- and thermochronologic data from along the St. Elias Mountains reveals details on the timing and rates of the Cenozoic tectonic evolution of the North American margin in southeast Alaska. Documented are the earliest Eocene spreading

  20. Genome-wide association analysis identifies a mutation in the thiamine transporter 2 (SLC19A3 gene associated with Alaskan Husky encephalopathy.

    Directory of Open Access Journals (Sweden)

    Karen M Vernau

    Full Text Available Alaskan Husky Encephalopathy (AHE has been previously proposed as a mitochondrial encephalopathy based on neuropathological similarities with human Leigh Syndrome (LS. We studied 11 Alaskan Husky dogs with AHE, but found no abnormalities in respiratory chain enzyme activities in muscle and liver, or mutations in mitochondrial or nuclear genes that cause LS in people. A genome wide association study was performed using eight of the affected dogs and 20 related but unaffected control AHs using the Illumina canine HD array. SLC19A3 was identified as a positional candidate gene. This gene controls the uptake of thiamine in the CNS via expression of the thiamine transporter protein THTR2. Dogs have two copies of this gene located within the candidate interval (SLC19A3.2 - 43.36-43.38 Mb and SLC19A3.1 - 43.411-43.419 Mb on chromosome 25. Expression analysis in a normal dog revealed that one of the paralogs, SLC19A3.1, was expressed in the brain and spinal cord while the other was not. Subsequent exon sequencing of SLC19A3.1 revealed a 4bp insertion and SNP in the second exon that is predicted to result in a functional protein truncation of 279 amino acids (c.624 insTTGC, c.625 C>A. All dogs with AHE were homozygous for this mutation, 15/41 healthy AH control dogs were heterozygous carriers while 26/41 normal healthy AH dogs were wild type. Furthermore, this mutation was not detected in another 187 dogs of different breeds. These results suggest that this mutation in SLC19A3.1, encoding a thiamine transporter protein, plays a critical role in the pathogenesis of AHE.

  1. Energy fluxes retrieval on an Alaskan Arctic and Sub-Arctic vegetation by means MODIS imagery and the DTD method

    Science.gov (United States)

    Cristobal, J.; Prakash, A.; Starkenburg, D. P.; Fochesatto, G. J.; Anderson, M. C.; Gens, R.; Kane, D. L.; Kustas, W.; Alfieri, J. G.

    2012-12-01

    Evapotranspiration (ET) plays a significant role in the hydrologic cycle of Arctic and Sub-Arctic basins. Surface-atmosphere exchanges due to ET are estimated from water balance computations to be about 74% of summer precipitation or 50% of annual precipitation. Even though ET is a significant component of the hydrologic cycle in this region, the bulk estimates don't accurately account for spatial and temporal variability due to vegetation type, topography, etc. (Kane and Yang, 2004). Nowadays, remote sensing is the only technology capable of providing the necessary radiometric measurements for the calculation of the ET at global scales and in a feasible economic way, especially in Arctic and Sub-Arctic Alaskan basins with a very sparse network of both meteorological and flux towers. In this work we present the implementation and validation of the Dual-Time-Difference model (Kustas et al., 2001) to retrieve energy fluxes (ET, sensible heat flux, net radiation and soil heat flux) in tundra vegetation in Arctic conditions and in a black spruce (Picea mariana) forest in Sub-Arctic conditions. In order to validate the model in tundra vegetation we used a flux tower from the Imnavait Creek sites of the Arctic Observatory Network (Euskirchen et al. 2012). In the case of the black spruce forest, on September 2011 we installed a flux tower in the University of Alaska Fairbanks north campus that includes an eddy-covariance system as well a net radiometer, air temperature probes, soil heat flux plates, soil moisture sensors and thermistors to fully estimate energy fluxes in the field (see http://www.et.alaska.edu/ for further details). Additionally, in order to upscale energy fluxes into MODIS spatial resolution, a scintillometer was also installed covering 1.2 km across the flux tower. DTD model mainly requires meteorological inputs as well as land surface temperature (LST) and leaf area index (LAI) data, both coming from satellite imagery, at two different times: after

  2. Alaskan sport fishing waters

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — As a guide to newcomers and visitors, fishery biologists have compiled a list of some of the well-known fishing waters in Alaska. The list is merely a starting point...

  3. Distribution, Abundance, Behavior, and Bioacoustics of Endangered Whales in the Alaskan Beaufort and Eastern Chukchi Seas, 1979-86.

    Science.gov (United States)

    1987-07-01

    Habitat Relationships and Behavior 70 d. Calf Sightings and Estimated Recruitment 72 Other Marine Mammals 72 a. Belukha ( Delphinapterus leucas ) 72 b...been seen in the Chukchi Sea only in 3uly. Other Marine Mammals a. Belukha, or White Whale ( Delphinapterus leucas ) There were 109 sightings of 492...physalus) whales in the St . Lawrence river (Macfarlane, 1981); and minke whales (Balaenoptera acutorostrata) off 3apan (Nishiwaki and Sasao, 1977

  4. Tracing pyrogenic carbon suspended in rivers on a global scale

    Science.gov (United States)

    Wiedemeier, Daniel B.; Haghipour, Negar; McIntyre, Cameron P.; Eglinton, Timothy I.; Schmidt, Michael W. I.

    2016-04-01

    Combustion-derived, pyrogenic carbon (PyC) is a persistent organic carbon fraction. Due to its aromatic and condensed nature (Wiedemeier et al., 2015), it is relatively resistant against chemical and biological degradation in the environment, leading to a comparatively slow turnover, which would support carbon sequestration. PyC is produced on large scales (hundreds of teragrams) in biomass burning events such as wildfires, and by combustion of fossil fuel in industry and traffic. PyC is an inherently terrestrial product and thus has predominantly been investigated in soils and the atmosphere. Much fewer studies are available about the subsequent transport of PyC to rivers and oceans. Recently, awareness has been rising about the mobility of PyC from terrestrial to marine systems and its fate in coastal and abyssal sediments was recognized (Mitra et al, 2013). It is therefore crucial to extend our knowledge about the PyC cycle by tracing PyC through all environmental compartments. By comparing its biogeochemical behavior and budgets to that of other forms of organic carbon, it will eventually be possible to elucidate PyC's total spatiotemporal contribution to carbon sequestration. In this study, we use a state-of-the-art PyC molecular marker method (Wiedemeier et al., 2013, Gierga et al., 2014) to trace quantity, quality as well as 13C and 14C signature of PyC in selected major river systems around the globe (Godavari, Yellow, Danube, Fraser, Mackenzie and Yukon river). Different size fractions of particulate suspended sediment are analyzed and compared across a north-south gradient. Previous studies suggested a distinct relationship between the 14C age of plant-derived suspended carbon and the latitude of the river system, indicating slower cycling of plant biomarkers in higher latitudes. We discuss this pattern with respect to PyC, its isotopic signature and quality and the resulting implications for the global carbon and PyC cycle. References Wiedemeier, D.B. et

  5. Using High Spatio-Temporal Optical Remote Sensing to Monitor Dissolved Organic Carbon in the Arctic River Yenisei

    Directory of Open Access Journals (Sweden)

    Pierre-Alexis Herrault

    2016-09-01

    Full Text Available In Arctic regions, a major concern is the release of carbon from melting permafrost that could greatly exceed current human carbon emissions. Arctic rivers drain these organic-rich watersheds (Ob, Lena, Yenisei, Mackenzie, Yukon but field measurements at the outlets of these great Arctic rivers are constrained by limited accessibility of sampling sites. In particular, the highest dissolved organic carbon (DOC fluxes are observed throughout the ice breakup period that occurs over a short two to three-week period in late May or early June during the snowmelt-generated peak flow. The colored fraction of dissolved organic carbon (DOC which absorbs UV and visible light is designed as chromophoric dissolved organic matter (CDOM. It is highly correlated to DOC in large arctic rivers and streams, allowing for remote sensing to monitor DOC concentrations from satellite imagery. High temporal and spatial resolutions remote sensing tools are highly relevant for the study of DOC fluxes in a large Arctic river. The high temporal resolution allows for correctly assessing this highly dynamic process, especially the spring freshet event (a few weeks in May. The high spatial resolution allows for assessing the spatial variability within the stream and quantifying DOC transfer during the ice break period when the access to the river is almost impossible. In this study, we develop a CDOM retrieval algorithm at a high spatial and a high temporal resolution in the Yenisei River. We used extensive DOC and DOM spectral absorbance datasets from 2014 and 2015. Twelve SPOT5 (Take5 and Landsat 8 (OLI images from 2014 and 2015 were examined for this investigation. Relationships between CDOM and spectral variables were explored using linear models (LM. Results demonstrated the capacity of a CDOM algorithm retrieval to monitor DOC fluxes in the Yenisei River during a whole open water season with a special focus on the peak flow period. Overall, future Sentinel2/Landsat8

  6. Yellow River, Cradle of China

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    THE Yellow River is the Mother River of China. In the hearts of the Chinese people, it is not just an ancient river measuring 4,845 kilometers long that passes through nine provinces and regions, but also a symbol. The poets say that the waterway is the image of ancient China. Thephilosophers say the river is the shadow of a dragon. The river

  7. Ice Atlas 1985 - 1986. Monongahela River, Allegheny River, Ohio River, Illinois River and Kankakee River.

    Science.gov (United States)

    1987-11-01

    V 0 1m =1 uvydae aury1,18 Belevlle oo Sufc MAPUNTS( MArea concentration MAP NITS(in 2 x 106) (%/) Oppen water 24.97 NA Solid ice cover 0.00 NA Solid...January 28, 1986 ideo Ta-pe 14 Lock and Dam #3 Pool.- Allegheny River: 1/1 / New Kensington Bridge 19- Lock and Dam #2 Pool Surface MArea

  8. "Ghost river": The Columbia

    OpenAIRE

    Gayton, D.

    2001-01-01

    Metadata only record This perspective piece examines the history and geography of the Columbia River and some current ecosystem management issues related to hydroelectric development on the river. Once the greatest salmon producer in the word, the Columbia has, according to the author, become a "ghost river," with its salmon runs reduced to remnants, and its ecological integrity hanging in the balance. The author suggests that British Columbians have much to lose, both biologically and cul...

  9. Down to the River

    DEFF Research Database (Denmark)

    Wessels, Josepha Ivanka

    2015-01-01

    Currently there is no coherent or sustainable water cooperation among the five states—Israel, Jordan, Lebanon, Palestinian territories and Syria—that share the Jordan River. Why do people not cooperate on sustainable river basin management, even if it seems the most rational course from...... to illustrate hydropolitics in praxis, because the political future of this particular area in many respects affects the sustainable future of the Jordan River Basin and the entire Levant....

  10. Investing in river health.

    Science.gov (United States)

    Bennett, J

    2002-01-01

    Rivers provide society with numerous returns. These relate to both the passive and extractive uses of the resources embodied in river environments. Some returns are manifest in the form of financial gains whilst others are non-monetary. For instance, rivers are a source of monetary income for those who harvest their fish. The water flowing in rivers is extracted for drinking and to water crops and livestock that in turn yield monetary profits. However, rivers are also the source of non-monetary values arising from biological diversity. People who use them for recreation (picnicking, swimming, boating) also receive non-monetary returns. The use of rivers to yield these returns has had negative consequences. With extraction for financial return has come diminished water quantity and quality. The result has been a diminished capacity of rivers to yield (non-extractive) environmental returns and to continue to provide extractive values. A river is like any other asset. With use, the value of an asset depreciates because its productivity declines. In order to maintain the productive capacity of their assets, managers put aside from their profits depreciation reserves that can be invested in the repair or replacement of those assets. Society now faces a situation in which its river assets have depreciated in terms of their capacity to provide monetary and non-monetary returns. An investment in river "repair" is required. But, investment means that society gives up something now in order to achieve some benefit in the future. Society thus has to grapple wih the choice between investing in river health and other investments--such as in hospitals, schools, defence etc. - as well as between investing in river health and current consumption--such as on clothes, food, cars etc. A commonly used aid for investment decision making in the public sector is benefit cost analysis. However, its usefulness in tackling the river investment problem is restricted because it requires all

  11. River Corridors (Jan 2, 2015)

    Data.gov (United States)

    Vermont Center for Geographic Information — River corridors are delineated to provide for the least erosive meandering and floodplain geometry toward which a river will evolve over time. River corridor maps...

  12. Tidal river dynamics

    NARCIS (Netherlands)

    Hoitink, A.J.F.; Jay, D.A.

    2016-01-01

    Tidal rivers are a vital and little studied nexus between physical oceanography and hydrology. It is only in the last few decades that substantial research efforts have been focused on the interactions of river discharge with tidal waves and storm surges into regions beyond the limit of salinity

  13. Reining the River

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Concerned about the effects of increasing water scarcity on economic development, China hopes a new law will save the Yellow River The first day of August marked what could be a new page in the history of China's long-suffering "mother river." That day, a regulation took effect that for the first time in histo-

  14. Reconstruction of a high-resolution late holocene arctic paleoclimate record from Colville River delta sediments.

    Energy Technology Data Exchange (ETDEWEB)

    Schreiner, Kathryn Melissa; Lowry, Thomas Stephen

    2013-10-01

    This work was partially supported by the Sandia National Laboratories, Laboratory Directed Research and Development (LDRD) fellowship program in conjunction with Texas A&M University (TAMU). The research described herein is the work of Kathryn M. Schreiner (Katie) and her advisor, Thomas S. Bianchi and represents a concise description of Katies dissertation that was submitted to the TAMU Office of Graduate Studies in May 2013 in partial fulfillment of her doctorate of philosophy degree. High Arctic permafrost soils contain a massive amount of organic carbon, accounting for twice as much carbon as what is currently stored as carbon dioxide in the atmosphere. However, with current warming trends this sink is in danger of thawing and potentially releasing large amounts of carbon as both carbon dioxide and methane into the atmosphere. It is difficult to make predictions about the future of this sink without knowing how it has reacted to past temperature and climate changes. This project investigated long term, fine scale particulate organic carbon (POC) delivery by the high-Arctic Colville River into Simpsons Lagoon in the near-shore Beaufort Sea. Modern POC was determined to be a mixture of three sources (riverine soils, coastal erosion, and marine). Downcore POC measurements were performed in a core close to the Colville River output and a core close to intense coastal erosion. Inputs of the three major sources were found to vary throughout the last two millennia, and in the Colville River core covary significantly with Alaskan temperature reconstructions.

  15. Provenance of Holocene sediment on the Chukchi-Alaskan margin based on combined diffuse spectral reflectance and quantitative X-Ray Diffraction analysis

    Science.gov (United States)

    Ortiz, J.D.; Polyak, L.; Grebmeier, J.M.; Darby, D.; Eberl, D.D.; Naidu, S.; Nof, D.

    2009-01-01

    Sediment clay and silt mineral assemblages provide an excellent means of assessing the provenance of fine-grained Arctic sediment especially when a unique mineral assemblage can be tied to specific source areas. The diffuse spectral reflectance (DSR) first derivative measurements and quantitative X-Ray Diffraction (qXRD) on a high-resolution sediment core from the continental slope north of Alaska constrain the sediment mineralogy. DSR results are augmented by measurements on several adjacent cores and compared to surface sediment samples from the northern Alaskan shelf and slope. Using Principal Component Analysis (PCA), we infer that the three leading DSR modes relate to mixtures of smectite + dolomite, illite + goethite, and chlorite + muscovite. This interpretation is consistent with the down core qXRD results. While the smectite + dolomite, and illite + goethite factors show increased variability down core, the chlorite + muscovite factor had highest positive loadings in the middle Holocene, between ca. 6.0 and 3.6??ka. Because the most likely source of the chlorite + muscovite suite in this vicinity lies in the North Pacific, we argue that the oscillations in chlorite + muscovite values likely reflect an increase in the inflow of Pacific water to the Arctic through the Bering Strait. The time interval of this event is associated in other parts of the globe with a non-linear response of the climate system to the decrease in insolation, which may be related to changes in water exchange between the Pacific and Arctic Ocean. ?? 2009 Elsevier B.V.

  16. Characterization and evaluation of washability of Alaskan coals: Fifty selected seams from various coal fields: Final technical report, September 30, 1976-February 28, 1986. [50 coal seams

    Energy Technology Data Exchange (ETDEWEB)

    Rao, P.D.

    1986-09-01

    This final report is the result of a study initiated in 1976 to obtain washability data for Alaskan coals, to supplement the efforts of the US Department of Energy in their ongoing studies on washability of US coals. Washability characteristics were determined for fifty coal samples from the Northern Alaska, Chicago Creek, Unalakleet, Nenana, Matanuska, Beluga, Yentna and Herendeen Bay coal fields. The raw coal was crushed to 1-1/2 inches, 3/8 inch, 14 mesh and 65 mesh top sizes, and float-sink separations were made at 1.30, 1.40 and 1.60 specific gravities. A limited number of samples were also crushed to 200 and 325 mesh sizes prior to float-sink testing. Samples crushed to 65 mesh top size were also separated at 1.60 specific gravity and the float and sink products were characterized for proximate and ultimate analyses, ash composition and ash fusibility. 72 refs., 79 figs., 57 tabs.

  17. Dulbi River goose survey

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A survey of white-fronted goose (Anser albifrons) and Canada goose (Branta canadensis) broods was conducted on 58 3/8 miles of the Dulbi River in Alaska. Four...

  18. Wild and Scenic Rivers

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This map layer portrays the linear federally-owned land features (i.e., national parkways, wild and scenic rivers, etc.) of the United States, Puerto Rico, and the...

  19. Mackenzie River Delta, Canada

    Science.gov (United States)

    2007-01-01

    The Mackenzie River in the Northwest Territories, Canada, with its headstreams the Peace and Finley, is the longest river in North America at 4241 km, and drains an area of 1,805,000 square km. The large marshy delta provides habitat for migrating Snow Geese, Tundra Swans, Brant, and other waterfowl. The estuary is a calving area for Beluga whales. The Mackenzie (previously the Disappointment River) was named after Alexander Mackenzie who travelled the river while trying to reach the Pacific in 1789. The image was acquired on August 4, 2005, covers an area of 55.8 x 55.8 km, and is located at 68.6 degrees north latitude, 134.7 degrees west longitude. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  20. Russian River Analysis

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is an analysis and summary of progress toward achieving the interim management objectives for the Russian River during the 1979 season. Additionally,...

  1. The Carmans River Story

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In this study, undertaken as an independent project at Bellport High School, the authors have attempted to provide a historical description of the Carmans River area...

  2. Wind River: A Wild and Scenic River Analysis: Preliminary draft

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Wind River meets the criteria for inclusion in the National Wild and Scenic Rivers System. Subject to valid existing rights, the minerals in Federal lands which...

  3. Study on the Reutilization of River Sediment

    Institute of Scientific and Technical Information of China (English)

    LIU Gui-yun; JIANG Pei-hua; XI Dan-li

    2002-01-01

    Main components and properties of river sediment are introduced. Secondary pollution of river sediments to the water quality of the river is clarified. The methods of the reutilization of river sediment are elucidated.

  4. Integrating subsistence practice and species distribution modeling: assessing invasive elodea’s potential impact on Native Alaskan subsistence of Chinook salmon and whitefish

    Science.gov (United States)

    Luizza, Matthew; Evangelista, Paul; Jarnevich, Catherine S.; West, Amanda; Stewart, Heather

    2016-01-01

    Alaska has one of the most rapidly changing climates on earth and is experiencing an accelerated rate of human disturbance, including resource extraction and transportation infrastructure development. Combined, these factors increase the state’s vulnerability to biological invasion, which can have acute negative impacts on ecological integrity and subsistence practices. Of growing concern is the spread of Alaska’s first documented freshwater aquatic invasive plant Elodea spp. (elodea). In this study, we modeled the suitable habitat of elodea using global and state-specific species occurrence records and environmental variables, in concert with an ensemble of model algorithms. Furthermore, we sought to incorporate local subsistence concerns by using Native Alaskan knowledge and available statewide subsistence harvest data to assess the potential threat posed by elodea to Chinook salmon (Oncorhynchus tshawytscha) and whitefish (Coregonus nelsonii) subsistence. State models were applied to future climate (2040–2059) using five general circulation models best suited for Alaska. Model evaluations indicated that our results had moderate to strong predictability, with area under the receiver-operating characteristic curve values above 0.80 and classification accuracies ranging from 66 to 89 %. State models provided a more robust assessment of elodea habitat suitability. These ensembles revealed different levels of management concern statewide, based on the interaction of fish subsistence patterns, known spawning and rearing sites, and elodea habitat suitability, thus highlighting regions with additional need for targeted monitoring. Our results suggest that this approach can hold great utility for invasion risk assessments and better facilitate the inclusion of local stakeholder concerns in conservation planning and management.

  5. Integrating subsistence practice and species distribution modeling: assessing invasive elodea's potential impact on Native Alaskan subsistence of Chinook salmon and whitefish

    Science.gov (United States)

    Luizza, Matthew W.; Evangelista, Paul H.; Jarnevich, Catherine S.; West, Amanda; Stewart, Heather

    2016-07-01

    Alaska has one of the most rapidly changing climates on earth and is experiencing an accelerated rate of human disturbance, including resource extraction and transportation infrastructure development. Combined, these factors increase the state's vulnerability to biological invasion, which can have acute negative impacts on ecological integrity and subsistence practices. Of growing concern is the spread of Alaska's first documented freshwater aquatic invasive plant Elodea spp. (elodea). In this study, we modeled the suitable habitat of elodea using global and state-specific species occurrence records and environmental variables, in concert with an ensemble of model algorithms. Furthermore, we sought to incorporate local subsistence concerns by using Native Alaskan knowledge and available statewide subsistence harvest data to assess the potential threat posed by elodea to Chinook salmon ( Oncorhynchus tshawytscha) and whitefish ( Coregonus nelsonii) subsistence. State models were applied to future climate (2040-2059) using five general circulation models best suited for Alaska. Model evaluations indicated that our results had moderate to strong predictability, with area under the receiver-operating characteristic curve values above 0.80 and classification accuracies ranging from 66 to 89 %. State models provided a more robust assessment of elodea habitat suitability. These ensembles revealed different levels of management concern statewide, based on the interaction of fish subsistence patterns, known spawning and rearing sites, and elodea habitat suitability, thus highlighting regions with additional need for targeted monitoring. Our results suggest that this approach can hold great utility for invasion risk assessments and better facilitate the inclusion of local stakeholder concerns in conservation planning and management.

  6. 50 CFR 226.205 - Critical habitat for Snake River sockeye salmon, Snake River fall chinook salmon, and Snake River...

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Critical habitat for Snake River sockeye salmon, Snake River fall chinook salmon, and Snake River spring/summer chinook salmon. 226.205 Section... Snake River sockeye salmon, Snake River fall chinook salmon, and Snake River spring/summer...

  7. 33 CFR 207.380 - Red Lake River, Minn.; logging regulations for portion of river above Thief River Falls.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Red Lake River, Minn.; logging regulations for portion of river above Thief River Falls. 207.380 Section 207.380 Navigation and Navigable... Red Lake River, Minn.; logging regulations for portion of river above Thief River Falls. (a)...

  8. The Nile River

    Science.gov (United States)

    2002-01-01

    This image of the northern portion of the Nile River was captured by MISR's nadir camera on January 30, 2001 (Terra orbit 5956). The Nile is the longest river in the world, extending for about 6700 kilometers from its headwaters in the highlands of eastern Africa. At the apex of the fertile Nile River Delta is the Egyptian capital city of Cairo. To the west are the Great Pyramids of Giza. North of here the Nile branches into two distributaries, the Rosetta to the west and the Damietta to the east. Also visible in this image is the Suez Canal, a shipping waterway connecting Port Said on the Mediterranean Sea with the Gulf of Suez. The Gulf is an arm of the Red Sea, and is located on the righthand side of the picture. Image credit: NASA/GSFC/LaRC/JPL, MISR Team.

  9. Sprague River Oregon Bars 1968

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the U.S....

  10. Sprague River Oregon Bars 2000

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the...

  11. Sprague River Oregon Centerline 2000

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the U.S....

  12. Sprague River Oregon Centerline 1940

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the U.S....

  13. Sprague River Oregon Water 1940

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the U.S....

  14. Sprague River Oregon Water 1968

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the U.S....

  15. Sprague River Oregon Bars 1940

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the U.S....

  16. Missouri River 1943 Compact Line

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — Flood Control, Bank Stabilization and development of a navigational channel on the Missouri River had a great impact on the river and adjacent lands. The new...

  17. Sprague River Oregon Floodplain 1968

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the U.S....

  18. Sprague River Oregon Floodplain 2000

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the...

  19. Sprague River Oregon Floodplain Boundary

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the U.S....

  20. Sprague River Oregon Centerline 2005

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the U.S....

  1. Sprague River Oregon Floodplain Centerline

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the U.S....

  2. Two Pontic rivers

    DEFF Research Database (Denmark)

    Bekker-Nielsen, Tønnes; Jensen, Marit

    2015-01-01

    The accounts of the landscape around the Iris (Yeşilirmak) and the Thermodon (Terme) given by ancient authors are diverse and often contradictory. The Periegesis of the World by Dionysius of Alexandria, a didactic poem written in the early IInd c. A.D., established an image of the two rivers...... that does not correspond to their actual characteristics. A closer study reveals that Dionysius, or possibly his source, has confused the two: the river which he describes as the Thermodon is in fact the Iris, and vice versa. This mistake was not realized by later translators (Avienus, late IVth c. A...

  3. The Gediz River fluvial archive

    NARCIS (Netherlands)

    Maddy, D.; Veldkamp, A.; Demir, T.; Gorp, van W.; Wijbrans, J.R.; Hinsbergen, van D.J.J.; Dekkers, M.J.; Schreve, D.; Schoorl, J.M.; Scaife, R.

    2016-01-01

    The Gediz River, one of the principal rivers of Western Anatolia, has an extensive Pleistocene fluvial archive that potentially offers a unique window into fluvial system behaviour on the western margins of Asia during the Quaternary. In this paper we review our work on the Quaternary Gediz River

  4. Nowitna River goose survey, 1986

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — An aerial goose survey of the upper Nowitna River and a river-floating goose brood survey of the upper Nowitna River were conducted May 27th through July 5th of...

  5. Ecological River Basin Management.

    Science.gov (United States)

    Smith, Anthony Wayne

    Addressing the Seventh American Water Resources Conference, Washington, D. C., October, 1971, Anthony Wayne Smith, President, National Parks and Conservation Association, presents an expose on how rivers should be managed by methods which restores and preserve the natural life balances of the localities and regions through which they flow. The…

  6. Hood River Production Master Plan.

    Energy Technology Data Exchange (ETDEWEB)

    O' Toole, Patty

    1991-07-01

    The Northwest Power Planning Council's 1987 Columbia River Fish and Wildlife Program authorizes the development of artificial production facilities to raise chinook salmon and steelhead for enhancement in the Hood, Umatilla, Walla Walla, Grande Ronde and Imnaha rivers and elsewhere. On February 26, 1991 the Council agreed to disaggregate Hood River from the Northeast Oregon Hatchery Project, and instead, link the Hood River Master Plan (now the Hood River Production Plan) to the Pelton Ladder Project (Pelton Ladder Master Plan 1991).

  7. Megafauna recovered from a cold hydrocarbon seep in the deep Alaskan Beaufort Sea, including a new species of Axinus (Thracidae: Bivalvia: Mollusca)

    Science.gov (United States)

    Powell, C. L.; Valentich-Scott, P.; Lorenson, T. D.; Edwards, B. D.

    2011-12-01

    Several specimens of a new species of Axinus and a single well-worn gastropod columella provisionally assigned to the genus Neptunea (Buccinidae: Gastropoda: Mollusca) were recently recovered from at least two cores, the longest of which is 5.72 m long, from a large seafloor mound, informally named the Canning Seafloor Mound (CSM). The CSM is located at 2,530 m water depth on the Alaskan Beaufort Sea slope north of Camden Bay and is a fluid explosion feature containing methane hydrate and methane-saturated sediments overlying a folded and faulted deep basin. Only two modern species of Axinus are currently known. Axinus grandis (Verrill & Smith, 1885) is a northern Atlantic species and the recently described species, A. cascadiensis Oliver and Holmes (2007), is only known from Baby Bare Seamount, Cascadia Basin, northeastern Pacific Ocean. Common fragments, single valves, and a single articulated specimen represent this new Axinus species. These shells were distributed over nearly the entire length of the primary core. All specimens show wear and (or) dissolution. The age of these specimens is unknown and no living representatives were encountered. The genus Axinus has a fossil record back to the early Eocene in England and the Paleocene and Eocene in Egypt. Biogeographically the genus appears to have originated in the Tethys Sea and became established in the Atlantic Ocean during the Eocene, spreading across the Arctic Ocean in the late Tertiary. With the opening of the Bering Strait in the latest Miocene or early Pliocene the genus Axinus migrated southwest into the northeast Pacific. Interestingly, hydrocarbon seep deposits are also present on the adjacent North Slope of Alaska in the Marsh Anticline at Carter Creek, Camden Bay. These rocks, the Nuwok beds, contain abundant Thracidae bivalve of the genus Thracia, but not Axinus, however the rocks also represent cold seep deposits. These rocks have been variously dated from Oligocene to Pliocene and the exact age

  8. Seasonality and long term trends in dissolved carbon export from large rivers to the Arctic Ocean, and potential effects on coastal ocean acidification (Invited)

    Science.gov (United States)

    Tank, S. E.; Kokelj, S. V.; Raymond, P. A.; Striegl, R. G.; McClelland, J. W.; Holmes, R. M.; Spencer, R. G.

    2013-12-01

    Large Arctic rivers show marked seasonality in constituent flux as a result of variations in flowpath throughout the yearly cycle. Here, we use measurements collected from the mouths of the six largest rivers draining to the Arctic Ocean to explore seasonal variation in dissolved inorganic and dissolved organic carbon (DIC, DOC) flux, and the effect of this flux on nearshore ocean processes. This work uses data from the Yukon and Mackenzie Rivers in North America, and the Kolyma, Lena, Yenisey, and Ob' in Siberia. Mean monthly concentrations of riverine DIC vary synchronously across all rivers, peaking under ice and reaching a low point immediately after the spring freshet. Monthly climatologies for DIC, in addition to similarly constructed climatologies for Ca2+, show that the input of riverwater universally causes aragonite to be undersaturated in riverine-influenced nearshore regions, with an effect that is greater for the Siberian coast than for western North America, and greater in the spring-winter than in the late summer and fall. Because seasonal trends and geographic variation in DOC concentration are opposite to that for DIC in these large rivers, degradation of DOC to CO2 in the nearshore Arctic should accentuate seasonal and spatial patterns in aragonite undersaturation in Arctic coastal regions. Datasets that extend DIC and DOC concentration measurements back to the early 1970's (DIC) and early 1980's (DOC) near the mouth of the Mackenzie River in the western Canadian Arctic indicate that the summertime concentration and flux of these constituents has been increasing over time in this region. While evidence from other regions of the pan-Arctic, and data gathered from smaller sub-catchment studies indicate that this trend is not universal for DOC, there is growing evidence for a consistent increase in summertime DIC flux across both time and gradients of decreasing permafrost extent. These changes, in turn, could have broad implications for both

  9. The world-class Howard's Pass SEDEX Zn-Pb district, Selwyn Basin, Yukon. Part I: trace element compositions of pyrite record input of hydrothermal, diagenetic, and metamorphic fluids to mineralization

    Science.gov (United States)

    Gadd, Michael G.; Layton-Matthews, Daniel; Peter, Jan M.; Paradis, Suzanne J.

    2016-03-01

    The Howard's Pass district, located in Yukon Territory, comprises 14 Zn-Pb sedimentary exhalative (SEDEX) deposits that collectively contain approximately 400.7 Mt grading at 4.5 % Zn and 1.5 % Pb. Sulfide mineralization is hosted in carbonaceous and calcareous to siliceous mudstones. Pyrite is a minor but ubiquitous component. Detailed petrographic analyses reveal that pyrite has a complex and protracted growth history, and multiple generations of pyrite are preserved in single grains. Combined electron probe microanalysis (EPMA) and laser ablation-inductively coupled mass plasma-mass spectrometry (LA-ICP-MS) of paragenetically complex pyrite reveal minor and trace element zonation that mimic textural features. These data provide information on the relative timing and cation content of depositional (i.e., ambient marine), hydrothermal, and metamorphic fluids. These data also identify a suite of nonore elements (Mn, As, Ag, Sb, and Tl) associated with the Zn-Pb mineralizing hydrothermal fluids. Lithogeochemical data and statistical results corroborate the microanalytical findings. These elements are associated with both syngenetic to earliest diagenetic pyrite and later diagenetic pyrite overgrowths, suggesting that SEDEX mineralization was not only the product of hydrothermal precipitates that settled on the seafloor, but also dense metalliferous brine also settled on, and percolated through, unconsolidated carbonaceous muds and precipitated metals. This genetic model is similar to that proposed for the Paleoproterozoic HYC Zn-Pb-Ag SEDEX deposit in northern Australia, and it is likely that common processes and ambient conditions led to the formation and preservation of both of these large SEDEX districts.

  10. Comparative Study of Flood Risk Management and Land Use in the Deltas of Rhine River, Yellow River and Mississippi River

    NARCIS (Netherlands)

    Huang B; Guangzhou, M.

    2007-01-01

    The Rhine River in the Netherlands, the Yellow River in China and the Mississippi River in the U.S. are three great rivers in the world. Each of them is performing a significant role in the country. The delta area for each river, in particular, is served as the centre in importance and commonly the

  11. River Mileages and Drainage Areas for Illinois Streams. Volume 2. Illinois River Basin.

    Science.gov (United States)

    1979-12-01

    FOREST 50.2 MADISON STREET RIVER FOREST 50.5 IL PT 56 RIVER FOREST 51.0 C & NW RR RIVER FOREST 51.1 LAKE STREET RIVER FOREST 51.6 CHICAGO AVENUE RIVER ... FOREST 51.9 SILVER CREEK R RIVER FOREST 53.9 DAM S35v40NoRI2E RIVER FOREST 54.2 NORTH PUEBLO AVENUE RIVER FOREST 55.1 GRAND AVENUE RIVER FOREST 55.1...USGS GAGE 05530600 AT RIVER GROVE 451 415546 O75040 RIVER

  12. River and Human Rights

    Institute of Scientific and Technical Information of China (English)

    NIE WUGANG; MENG JIA

    2011-01-01

    @@ Nothing is like a river.It seems coming from nowhere, far back into antiquity.It is originated from drops of water and converged into a long stream that flows ceaselessly.It benefits the vast expanse of land and nourishes all the living on it.It stretches and undulates,forming ponds and lakes of different depths.It is moving or motionless,overflowing with vigor and vitality.

  13. Investigation on Water Pollution of Four Rivers in Coastal Wetland of Yellow River Estuary

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The study aimed at analysing water pollution of four rivers in coastal wetland of Yellow River estuary. [Method] Taking four seriously polluted rivers (Guangli River, Shenxian Ditch, Tiao River and Chao River) in coastal wetland of Yellow River estuary as study objects, water samples were collected from the four rivers in May (dry period), August (wet period) and November (normal period) in 2009 and 2010 respectively, then pollution indices like nutritive salts, COD, chlorophyll-a, petroleum, et...

  14. Flooding on Elbe River

    Science.gov (United States)

    2002-01-01

    Heavy rains in Central Europe over the past few weeks have led to some of the worst flooding the region has witnessed in more than a century. The floods have killed more than 100 people in Germany, Russia, Austria, Hungary, and the Czech Republic and have led to as much as $20 billion in damage. This false-color image of the Elbe River and its tributaries was taken on August 20, 2002, by the Moderate Resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra satellite. The floodwaters that inundated Dresden, Germany, earlier this week have moved north. As can be seen, the river resembles a fairly large lake in the center of the image just south of the town of Wittenberg. Flooding was also bad further downriver in the towns of Maqgdeburge and Hitzacker. Roughly 20,000 people were evacuated from their homes in northern Germany. Fifty thousand troops, border police, and technical assistance workers were called in to combat the floods along with 100,000 volunteers. The floodwaters are not expected to badly affect Hamburg, which sits on the mouth of the river on the North Sea. Credit:Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  15. Tsunami Impacts in River Environments

    Science.gov (United States)

    Tolkova, E.; Tanaka, H.; Roh, M.

    2014-12-01

    The 2010 Chilean and the 2011 Tohoku tsunami events demonstrated the tsunami's ability to penetrate much farther along rivers than the ground inundation. At the same time, while tsunami impacts to the coastal areas have been subject to countless studies, little is known about tsunami propagation in rivers. Here we examine the field data and conduct numerical simulations to gain better understanding of the tsunami impacts in rivers.The evidence which motivated our study is comprised of water level measurements of the aforementioned tsunamis in multiple rivers in Japan, and the 2011 Tohoku and some other tsunamis in the Columbia River in the US. When the available tsunami observations in these very different rivers are brought together, they display remarkably similar patterns not observed on the open coast. Two phenomena were discovered in the field data. First, the phase of the river tide determines the tsunami penetration distance in a very specific way common to all rivers. Tsunami wave progressively disappears on receding tide, whereas high tide greatly facilitates the tsunami intrusion, as seen in the Figure. Second, a strong near-field tsunami causes substantial and prolonged water accumulation in lower river reaches. As the 2011 tsunami intruded rivers in Japan, the water level along rivers rose 1-2 m and stayed high for many hours, with the maximum rise occurring several km from the river mouth. The rise in the water level at some upstream gaging stations even exceeded the tsunami amplitude there.Using the numerical experiments, we attempt to identify the physics behind these effects. We will demonstrate that the nonlinear interactions among the flow components (tsunami, tide, and riverine flow) are an essential condition governing wave dynamics in tidal rivers. Understanding these interactions might explain some previous surprising observations of waves in river environments. Figure: Measurements of the 2010/02/27 tsunami along Naruse and Yoshida rivers

  16. Classification of freshwater ice conditions on the Alaskan Arctic Coastal Plain using ground penetrating radar and TerraSAR-X satellite data

    Science.gov (United States)

    Jones, Benjamin M.; Gusmeroli, Alessio; Arp, Christopher D.; Strozzi, Tazio; Grosse, Guido; Gaglioti, Benjamin V.; Whitman, Matthew S.

    2013-01-01

    Arctic freshwater ecosystems have responded rapidly to climatic changes over the last half century. Lakes and rivers are experiencing a thinning of the seasonal ice cover, which may increase potential over-wintering freshwater habitat, winter water supply for industrial withdrawal, and permafrost degradation. Here, we combined the use of ground penetrating radar (GPR) and high-resolution (HR) spotlight TerraSAR-X (TSX) satellite data (1.25 m resolution) to identify and characterize floating ice and grounded ice conditions in lakes, ponds, beaded stream pools, and an alluvial river channel. Classified ice conditions from the GPR and the TSX data showed excellent agreement: 90.6% for a predominantly floating ice lake, 99.7% for a grounded ice lake, 79.0% for a beaded stream course, and 92.1% for the alluvial river channel. A GIS-based analysis of 890 surface water features larger than 0.01 ha showed that 42% of the total surface water area potentially provided over-wintering habitat during the 2012/2013 winter. Lakes accounted for 89% of this area, whereas the alluvial river channel accounted for 10% and ponds and beaded stream pools each accounted for Arctic with increasing stressors related to climate and land use change.

  17. Red River of the North Reconnaissance Report: Park River Subbasin.

    Science.gov (United States)

    1980-12-01

    experienced a natural increase, and their inmigration rates were less than one percent. Cavalier County’s increase in population was the result of a...natural increase j and an inmigration rate of 5.4 percent. The two largest towns are Grafton and Park River, and they are both located on the Park River

  18. Sr-Isotope Composition of Feldspar: Implication for age and Evolution of Gabbros from Uralian-Alaskan Type Complexes in the Ural Mountains, Russia

    Science.gov (United States)

    Bruegmann, G. E.; Krause, J.; Pushkarev, E.

    2006-12-01

    Compared to whole-rock or bulk mineral analyses single mineral composition could reveal disequilibrium features between crystals or within individual crystals which provide important information on magma chamber processes. We applied a LA-ICPMS technique to determine Sr isotopes in plagioclase and K-feldspar of gabbroic rocks from the Nizhnii Tagil and Kytlym complexes in the Ural Mountains in Russia. These complexes are Uralian-Alaskan-type zoned mafic-ultramafic complexes, consisting of dunite, clinopyroxenite and gabbro bodies. The rock association is considered to represent a cumulate sequence of a single parental melt feeding a magma chamber system. The instruments used were a NU Plasma MC-ICPMS and a solid-state 193 and 213 nm Nd:YAG laser ablation system from New Wave. The data of the present study includes up to five spot analyses (100-120 μm spot size) of each mineral in a thin section. Baselines for analyses were measured on-peak for 20 s while flushing the sample chamber with He. About 300 to 500 isotope ratios were measured during the ablation time of 80-100 s. Raw data were exported to an external data reduction spreadsheet and corrected for interferences (Kr, Rb) and mass bias using 87Sr/^{88}Sr=0.1194. During the time of analyses we measured the Sr isotope composition of an in-house marine carbonate reference material. Its 87Sr/86Sr of 0.70923±6 (2SD) agrees within error limits with our TIMS measurements. The gabbros have porphyric textures with clinopyroxene phenocrysts in a matrix of olivine, clinopyroxene and spinel. Two gabbro types can be distinguished based on additional matrix minerals. One type of gabbro is silica saturated, contains plagioclase (An57-88) and in places orthopyroxene as matrix phases. The second gabbro type is silica undersaturated and contains in the matrix plagioclase (An29-56) and pseudoleucite, a fine grained intergrowth of nepheline and K-feldspar (Or30-81). In this gabbro plagioclase has generally higher Sr

  19. Skjern River Restoration Counterfactual

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel

    2014-01-01

    heritage. While the meanders of the Skjern River were reconstructed according to its assumed course in 1870s, the embanked canal, which was the main feature and symbol of a comprehensive cultivation project from the 1960s, was deconstructed and reduced to incomprehensible traces of the past. Not only did...... history and more openness towards constant change. In this approach the idea of palimpsest as metaphor for the cultural landscape plays an important role. Rather than being an obstacle for the restoration of nature, the historical layer following the comprehensive cultivation project from the 1960s...

  20. Taizhou Yangtze River Bridge

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Taizhou Bridge lies between Taizhou, Zhenjiang and Changzhou City in Jiangsu Province. The total length of Taizhou Bridge is 62.088 kin. The whole line is designed by freeway codes with six lanes in two directions. The wholeinvestment is 9.37 billion RMB and the planned construction duration is 5.5 years. The main bridge crossing the Yangtze River is a continuous three-pylon two-span suspension bridge with the main span of 1 080 m. The bridge system is realized for the first time and ranks first in the world until now.

  1. Stochastic Modelling of River Geometry

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Schaarup-Jensen, K.

    1996-01-01

    Numerical hydrodynamic river models are used in a large number of applications to estimate critical events for rivers. These estimates are subject to a number of uncertainties. In this paper, the problem to evaluate these estimates using probabilistic methods is considered. Stochastic models...

  2. Treasure Along the Parker River.

    Science.gov (United States)

    Fitzpatrick, Ann-Marie; And Others

    Designed so that 100 to 125 heterogeneously grouped 7th and 8th grade students and a team of 5 core teachers might experience and discover the natural and historical "treasure" in the Parker River area of Massachusetts, this interdisciplinary unit centers on a hike to Parker River (6.7 miles) and visits to a cemetery, a monument, and Old Town…

  3. Cetaceans and pinnipeds, Alaskan waters

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A tentative checklist of those species known or likely to occur in the inside waters of Southeastern Alaska or Prince William Sound and adjacent Gulf of Alaska.

  4. Observations afield on Alaskan wolves

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Widespread observations of wolves and their habits in Alaska during the period 1948-1954 generally confirm published reports of these phenomena elsewhere....

  5. Geomorphology and River Dynamics of the Lower Copper River, Alaska

    Science.gov (United States)

    Brabets, Timothy P.; Conaway, Jeffrey S.

    2009-01-01

    Located in south-central Alaska, the Copper River drains an area of more than 24,000 square miles. The average annual flow of the river near its mouth is 63,600 cubic feet per second, but is highly variable between winter and summer. In the winter, flow averages approximately 11,700 cubic feet per second, and in the summer, due to snowmelt, rainfall, and glacial melt, flow averages approximately 113,000 cubic feet per second, an order of magnitude higher. About 15 miles upstream of its mouth, the Copper River flows past the face of Childs Glacier and enters a large, broad, delta. The Copper River Highway traverses this flood plain, and in 2008, 11 bridges were located along this section of the highway. The bridges cross several parts of the Copper River and in recent years, the changing course of the river has seriously damaged some of the bridges. Analysis of aerial photography from 1991, 1996, 2002, 2006, and 2007 indicates the eastward migration of a channel of the Copper River that has resulted in damage to the Copper River Highway near Mile 43.5. Migration of another channel in the flood plain has resulted in damage to the approach of Bridge 339. As a verification of channel change, flow measurements were made at bridges along the Copper River Highway in 2005-07. Analysis of the flow measurements indicate that the total flow of the Copper River has shifted from approximately 50 percent passing through the bridges at Mile 27, near the western edge of the flood plain, and 50 percent passing through the bridges at Mile 36-37 to approximately 5 percent passing through the bridges at Mile 27 and 95 percent through the bridges at Mile 36-37 during average flow periods. The U.S. Geological Survey's Multi-Dimensional Surface-Water Modeling System was used to simulate water-surface elevation and velocity, and to compute bed shear stress at two areas where the Copper River is affecting the Copper River Highway. After calibration, the model was used to examine the

  6. Hood River Passive House

    Energy Technology Data Exchange (ETDEWEB)

    Hales, David [BA-PIRC, Spokane, WA (United States)

    2014-01-01

    The Hood River Passive Project was developed by Root Design Build of Hood River Oregon using the Passive House Planning Package (PHPP) to meet all of the requirements for certification under the European Passive House standards. The Passive House design approach has been gaining momentum among residential designers for custom homes and BEopt modeling indicates that these designs may actually exceed the goal of the U.S. Department of Energy's (DOE) Building America program to "reduce home energy use by 30%-50% (compared to 2009 energy codes for new homes). This report documents the short term test results of the Shift House and compares the results of PHPP and BEopt modeling of the project. The design includes high R-Value assemblies, extremely tight construction, high performance doors and windows, solar thermal DHW, heat recovery ventilation, moveable external shutters and a high performance ductless mini-split heat pump. Cost analysis indicates that many of the measures implemented in this project did not meet the BA standard for cost neutrality. The ductless mini-split heat pump, lighting and advanced air leakage control were the most cost effective measures. The future challenge will be to value engineer the performance levels indicated here in modeling using production based practices at a significantly lower cost.

  7. Latent resonance in tidal rivers, with applications to River Elbe

    Science.gov (United States)

    Backhaus, Jan O.

    2015-11-01

    We describe a systematic investigation of resonance in tidal rivers, and of river oscillations influenced by resonance. That is, we explore the grey-zone between absent and fully developed resonance. Data from this study are the results of a one-dimensional numerical channel model applied to a four-dimensional parameter space comprising geometry, i.e. length and depths of rivers, and varying dissipation and forcing. Similarity of real rivers and channels from parameter space is obtained with the help of a 'run-time depth'. We present a model-channel, which reproduces tidal oscillations of River Elbe in Hamburg, Germany with accuracy of a few centimetres. The parameter space contains resonant regions and regions with 'latent resonance'. The latter defines tidal oscillations that are elevated yet not in full but juvenile resonance. Dissipation reduces amplitudes of resonance while creating latent resonance. That is, energy of resonance radiates into areas in parameter space where periods of Eigen-oscillations are well separated from the period of the forcing tide. Increased forcing enhances the re-distribution of resonance in parameter space. The River Elbe is diagnosed as being in a state of anthropogenic latent resonance as a consequence of ongoing deepening by dredging. Deepening the river, in conjunction with the expected sea level rise, will inevitably cause increasing tidal ranges. As a rule of thumb, we found that 1 m deepening would cause 0.5 m increase in tidal range.

  8. River-Based Experiential Learning: the Bear River Fellows Program

    Science.gov (United States)

    Rosenberg, D. E.; Shirley, B.; Roark, M. F.

    2012-12-01

    The Department of Civil and Environmental Engineering, Outdoor Recreation, and Parks and Recreation programs at Utah State University (USU) have partnered to offer a new, unique river-based experiential learning opportunity for undergraduates called the Bear River Fellows Program. The program allows incoming freshmen Fellows to experience a river first hand during a 5-day/4-night river trip on the nearby Bear River two weeks before the start of their first Fall semester. As part of the program, Fellows will navigate the Bear River in canoes, camp along the banks, interact with local water and environmental managers, collect channel cross section, stream flow, vegetation cover, and topological complexity data, meet other incoming freshmen, interact with faculty and graduate students, develop boating and leadership skills, problem solve, and participate as full members of the trip team. Subsequently, Fellows will get paid as undergraduate researchers during their Fall and Spring Freshman semesters to analyze, synthesize, and present the field data they collect. The program is a collaborative effort between two USU academic units and the (non-academic) division of Student Services and supports a larger National Science Foundation funded environmental modelling and management project for the lower Bear River, Utah watershed. We have advertised the program via Facebook and emails to incoming USU freshmen, received 35 applications (60% women), and accepted 5 Fellows into the program (3 female and 2 male). The river trip departs August 14, 2012. The poster will overview the Bear River Fellows Program and present qualitative and preliminary outcomes emerging from the trip and Fellows' work through the Fall semester with the field data they collect. We will also undertake more rigorous and longer longitudinal quantitative evaluation of Program outcomes (for example, in problem-solving and leadership) both in Spring 2013 and in subsequent 2013 and 2014 offerings of the

  9. 75 FR 51938 - Drawbridge Operation Regulation; Taunton River, Fall River and Somerset, MA

    Science.gov (United States)

    2010-08-24

    ... River and Somerset, MA AGENCY: Coast Guard, DHS. ACTION: Final rule. SUMMARY: The Coast Guard has...) Bridge at mile 1.8, across the Taunton River between Fall River and Somerset, Massachusetts. This final..., across the Taunton River between Fall River and Somerset, Massachusetts, has a vertical clearance in...

  10. 78 FR 49918 - Drawbridge Operation Regulation; Taunton River, Fall River and Somerset, MA

    Science.gov (United States)

    2013-08-16

    ... River and Somerset, MA AGENCY: Coast Guard, DHS. ACTION: Final rule. SUMMARY: The Coast Guard has... across the Taunton River, mile 2.1, between Fall River and Somerset, Massachusetts. The bridge owner...) entitled, ``Drawbridge Operation Regulation: Taunton River, Fall River and Somerset, MA'' in the...

  11. 78 FR 62345 - Sabine River Authority of Texas; Sabine River Authority, State of Louisiana; Notice of...

    Science.gov (United States)

    2013-10-18

    ... Energy Regulatory Commission Sabine River Authority of Texas; Sabine River Authority, State of Louisiana; Notice of Authorization for Continued Project Operation On September 30 2011, the Sabine River Authority of Texas and Sabine River Authority, State of Louisiana (Sabine River Authorities), licensee(s)...

  12. 29 CFR 1917.126 - River banks.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false River banks. 1917.126 Section 1917.126 Labor Regulations...) MARINE TERMINALS Terminal Facilities § 1917.126 River banks. (a) This section applies to temporary installations or temporary operations near a river bank. (b) Where working surfaces at river banks slope...

  13. Theory and application of nonlinear river dynamics

    Institute of Scientific and Technical Information of China (English)

    Yu-chuan BAI; Zhao-yin WANG

    2014-01-01

    A theoretical model for river evolution including riverbed formation and meandering pattern formation is presented in this paper. Based on nonlinear mathematic theory, the nonlinear river dynamic theory is set up for river dynamic process. Its core content includes the stability and tropism characteristics of flow motion in river and river selves’ evolution. The stability of river dynamic process depends on the response of river selves to the external disturbance, if the disturbance and the resulting response will eventually attenuate, and the river dynamics process can be restored to new equilibrium state, the river dynamic process is known as stable;otherwise, the river dynamic process is unstable. The river dynamic process tropism refers to that the evolution tendency of river morphology after the disturbance. As an application of this theory, the dynamical stability of the constant curvature river bend is calculated for its coherent vortex disturbance and response. In addition, this paper discusses the nonlinear evolution of the river peristaltic process under a large-scale disturbance, showing the nonlinear tendency of river dynamic processes, such as river filtering and butterfly effect.

  14. Ice Jams the Ob River

    Science.gov (United States)

    2007-01-01

    Russia's Ob River flows from south to north, and each summer, it thaws in the same direction. The result is that an ice jam sits downstream from thawed portions of the river, which is laden with heavy runoff from melted snow. On June 29, 2007, the Moderate Resolution Imaging Spectroradiometer (MODIS) flying on NASA's Terra satellite captured this image of the almost completely thawed Ob River. The scene is typical for early summer. South of the ice jam, the Gulf of Ob is swollen with pent-up run-off, and upstream from that, the river is widened as well. Unable to carve through frozen land, the river has little choice but to overflow its banks. For a comparison of early summer and autumn conditions, see Flooding on the Ob River in the Earth Observatory's Natural Hazards section. Besides the annual overflow, this image captures other circumstances of early summer. Sea ice is retreating from the Kara Sea. A lingering line of snow cover snakes its way along the Ob River, to the west. And while the land is lush and green in the south, it appears barren and brown in the north. Near the mouth of the river and the Kara Sea, the land is cold-adapted tundra, with diminutive plants and a short growing season. Just as the ice plugging the river had yet to thaw in the Far North's short summer, the tundra had not yet to greened up either. In this image it still appears lifeless beige. NASA image courtesy Jeff Schmaltz, MODIS Rapid Response Team, Goddard Space Flight Center

  15. River history and tectonics.

    Science.gov (United States)

    Vita-Finzi, C

    2012-05-13

    The analysis of crustal deformation by tectonic processes has gained much from the clues offered by drainage geometry and river behaviour, while the interpretation of channel patterns and sequences benefits from information on Earth movements before or during their development. The interplay between the two strands operates at many scales: themes which have already benefited from it include the possible role of mantle plumes in the breakup of Gondwana, the Cenozoic development of drainage systems in Africa and Australia, Himalayan uplift in response to erosion, alternating episodes of uplift and subsidence in the Mississippi delta, buckling of the Indian lithospheric plate, and changes in stream pattern and sinuosity along individual alluvial channels subject to localized deformation. Developments in remote sensing, isotopic dating and numerical modelling are starting to yield quantitative analyses of such effects, to the benefit of geodymamics as well as fluvial hydrology.

  16. A River in the Desert

    Institute of Scientific and Technical Information of China (English)

    杨仲言

    1994-01-01

    The Arabian Peninsula today is a barren desert. But 6,000 yearsago, says Farouk El-Baz,a river ran through the heart of the peninsula.From the Hijaz Mountains in western Saudi Arabia, it flowed 530 milesnortheast, emptying into the Persian Gulf through a delta that coveredmost of present day Kuwait. The Kuwait River, as El-Baz has dubbedit, averaged 5 miles wide and 50 feet deep along its entire length, and itcarried gravel from the Hijaz all the way to Kuwait. "It must have been amighty river, "says El-Baz.

  17. Arctic River organic matter transport

    Science.gov (United States)

    Raymond, Peter; Gustafsson, Orjan; Vonk, Jorien; Spencer, Robert; McClelland, Jim

    2016-04-01

    Arctic Rivers have unique hydrology and biogeochemistry. They also have a large impact on the Arctic Ocean due to the large amount of riverine inflow and small ocean volume. With respect to organic matter, their influence is magnified by the large stores of soil carbon and distinct soil hydrology. Here we present a recap of what is known of Arctic River organic matter transport. We will present a summary of what is known of the ages and sources of Arctic River dissolved and particulate organic matter. We will also discuss the current status of what is known about changes in riverine organic matter export due to global change.

  18. Clinch River project: Sediment contaminants in the Lower Clinch River

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Sediment samples from three mainstem and seven tributary sites in the Clinch River Basin were analyzed for 21 organochlorine compounds, 19 metals, total volatile...

  19. Elwha River dam removal-Rebirth of a river

    Science.gov (United States)

    Duda, Jeffrey J.; Warrick, Jonathan A.; Magirl, Christopher S.

    2011-01-01

    After years of planning for the largest project of its kind, the Department of the Interior will begin removal of two dams on the Elwha River, Washington, in September 2011. For nearly 100 years, the Elwha and Glines Canyon Dams have disrupted natural processes, trapping sediment in the reservoirs and blocking fish migrations, which changed the ecology of the river downstream of the dams. All five Pacific salmon species and steelhead-historically present in large numbers-are locally extirpated or persist in critically low numbers. Upstream of the dams, more than 145 kilometers of pristine habitat, protected inside Olympic National Park, awaits the return of salmon populations. As the dams are removed during a 2-3 year project, some of the 19 million cubic meters of entrapped sediment will be carried downstream by the river in the largest controlled release of sediment into a river and marine waters in history. Understanding the changes to the river and coastal habitats, the fate of sediments, and the salmon recolonization of the Elwha River wilderness will provide useful information for society as future dam removals are considered.

  20. The Scientific Challenges of Yellow River Study

    Institute of Scientific and Technical Information of China (English)

    Liu Xiaoyan; Sun Yangbo

    2005-01-01

    @@ The Yellow River is famous for its complex and unique physical conditions which give great challenges to the river management. Based on the study and analysis of the existing problems and research progress, this paper indicated that the most significant challenges of Yellow River studies are: long term hydrological and morphological changes; the optimized hydrology and sediment conditions to maintain the healthy life of the River; and simulation of Yellow River through mathematical model and physical models.

  1. Togiak River sportfishing studies, 1984

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Nearly three thousand angler days of effort was estimated to have been spent on the Togiak River in 1984. Effort was clearly dominated by the professional guiding...

  2. Riparian Habitat - San Joaquin River

    Data.gov (United States)

    California Department of Resources — The immediate focus of this study is to identify, describe and map the extent and diversity of riparian habitats found along the main stem of the San Joaquin River,...

  3. Mississippi River Valley alluvial aquifer

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the extent of the Mississippi River Valley alluvial aquifer in the states of Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and...

  4. Umpqua River Oregon Geologic Floodplain

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Umpqua River drains 12,103 square kilometers (4,673 square miles) in southwest Oregon before flowing into the Pacific Ocean at Winchester Bay near the city of...

  5. Haw River sediment quality assessment

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report documents an evaluation of chemical contaminants in, and toxicity of, sediments collected from impoundments created by dams on the Haw River in Alamance...

  6. Upper Kenai River Cooperative Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Upper Kenai River Cooperative Plan is the product of a joint effort of the Chugach National Forest, Kenai National Wildlife Refuge, Alaska Division of Parks and...

  7. Arkansas River Water Needs Assessment

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report is on the legal elements, hydrologic analysis, objectives, and water levels related to the Arkansas River and the management of it.

  8. Bremner River, Alaska, a wild and scenic river analysis: Preliminary draft

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Bremner River possesses the values which qualify it for inclusion in the National Wild and Scenic Rivers System. The Bremner River fulfills the requirements of...

  9. 77 FR 45653 - Yakima River Basin Conservation Advisory Group; Yakima River Basin Water Enhancement Project...

    Science.gov (United States)

    2012-08-01

    ... Bureau of Reclamation Yakima River Basin Conservation Advisory Group; Yakima River Basin Water... on the structure, implementation, and oversight of the Yakima River Basin Water Conservation Program... of the Water Conservation Program, including the applicable water conservation guidelines of...

  10. Missouri River, Natural Resources Bibliography.

    Science.gov (United States)

    1997-07-01

    Dissertation Abstracts, UnCover, Agricola , and terrestrial habitats adjacent to the river resulted in a variety of bibliographies available on the Internet...106- 232. BUSINESS RESEARCH BUREAU. 1960. 16. Recreational survey of Lewis and Clark Lake and Fort Randall Reservoir. Bus. Res. Bur., 224. BURGESS RL...and 834. HORNER AND SHIFRIN I. 1987. Flood protection zoogeography of the Missouri River Valley in for Missouri Bottoms. Prepared for Business North

  11. Analysis on River Sediment Changes of the Upper Reaches of Yangtze River

    Institute of Scientific and Technical Information of China (English)

    ZHONG Xiang-hao; SHI Guo-yu; XU Quan-xi; CHEN Ze-fang; LIU Shu-zhen

    2005-01-01

    The sediment load and river sedimentation of the upper reaches of Yangtze River has been undergoing constant changes as complex landform, large mountain area and plentiful precipitation make the drainage area of Yangtze River very vulnerable to water erosion and gravity erosion. Through analyzing the hydrological and sediment load statistics recorded by major hydrological stations along Yangtze River since 1950s, and editing the accumulation graph of annual runoff volume and annual sediment load, we find out that the suspended-sediment of Yangtze river has been decreasing year by year in Wulong Hydrological Station on Wujiang River, Beibei Hydrological Station on Jialingjiang River, Lijiawan Hydrological Station on Tuojiang River and Gaochang Hydrological Station on Minjiang River, Yichang Hydrological Station, Cuntan Hydrological Station along Yangtze River mainstream share the same experience too. But the statistics obtained at Pingshan Hydrological Station on Jinshajiang River shows the sediment load there has increased. Taking ecological construction, hydraulic engineering construction and precipitation changes into consideration, the thesis analyses the causes for the sediment load decrease of Jialingjiang River, Tuojiang River, Minjiang River and Wujiang River and provides us both scientific foundation for further study of river sediment changes of the upper reaches of Yangtze River, and measures to control river sedimentation.

  12. Ecosystem Services of Rivers: The Don River (Russian Federation) and the Roanoke River (USA)

    Science.gov (United States)

    The concept of ecosystem services recognizes the services, and benefits, provided to people by ecosystems. River systems provide many services to people, including freshwater provisioning, carbon storage, fisheries, recreation, transportation, and biodiversity. Here, we review th...

  13. Valley evolution by meandering rivers

    Science.gov (United States)

    Limaye, Ajay Brian Sanjay

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

  14. PRINCIPLES OF RIVER TRAINING AND MANAGEMENT

    Institute of Scientific and Technical Information of China (English)

    Zhaoyin WANG; Shimin TIAN; Yujun YI; Guoan YU

    2007-01-01

    River regulation and river training have been performed for various purposes and negative effects have been shown in numerous cases. In some cases the negative effects are so serious that humans have to consider to "renaturalize" the regulated rivers. Only by using the strategy of integrated river management the diverse river uses and natural fluvial processes and ecological systems may be harmonized. Based on analysis of case studies and data collected from literatures this paper presents the concept of integrated river management and four principles of river training. The integrated river management comprises: 1) taking the watershed, upper stream basin including the tributaries, middle and lower reaches and the estuary as an integrated entity in the planning, design and management; and 2) mitigating or controlling the negative impacts on hydrology, erosion and sedimentation, fluvial processes, land use and river use, environment and ecology while in achieving economic benefit from water resources development, flood safety management and hydropower exploitation. River training and management should be in accordance with the four principles: 1) extending the duration of river water flowing on the continent, which may be achieved by extending the river course or reducing the flow velocity; 2) controlling various patterns of erosions and reducing the sediment transportation in the rivers; 3) increasing the diversity of habitat and enhancing the connectivity between the river and riparian waters; and 4) restoring natural landscapes.

  15. The Kipawa River versus the Tabaret River diversion projects

    Energy Technology Data Exchange (ETDEWEB)

    Karwacki, P. [Ottawa, ON (Canada)

    2003-08-01

    Hydro-Quebec wants to divert the Kipawa River in northwest Quebec from its natural streambed. While the first time visitor is likely to emphatically proclaim the Kipawa River as the most beautiful, most serene place they have ever encountered, hydro consultants and engineers, disconnected from the attractiveness of that place, are making cost/benefit recommendations that marginalize the inherent value of a free-flowing Kipawa. This paper will discuss the following points: (1) The Kipawa River has its own inherent value, which is related to the cost of simulating threatened white-water habitats in general. (2) The costs of recreating white-water habitats are more understandable through the study of man-made white-water venues. (3) The cost to recreate or simulate a threatened white-water habitat should be factored into the cost of the hydro-project feasibility. The Kipawa River's own inherent value should be factored into the cost of the Tabaret Diversion Project. (4) Methods of gaining community acceptance should be public and open: independent third-party arbitration is recommended. Use of monetary incentives to encourage public acceptance is unethical, immoral and unjustly biased against the survival of white-water habitats. (5) Recreational use of white-water habitats, like the Kipawa River are increasingly important engines of economic growth in Canada and around the world. (author)

  16. The river model of black holes

    OpenAIRE

    Hamilton, Andrew J. S.; Lisle, Jason P.

    2004-01-01

    This paper presents an under-appreciated way to conceptualize stationary black holes, which we call the river model. The river model is mathematically sound, yet simple enough that the basic picture can be understood by non-experts. %that can by understood by non-experts. In the river model, space itself flows like a river through a flat background, while objects move through the river according to the rules of special relativity. In a spherical black hole, the river of space falls into the b...

  17. Intermittent ephemeral river-breaching

    Science.gov (United States)

    Reniers, A. J.; MacMahan, J. H.; Gallagher, E. L.; Shanks, A.; Morgan, S.; Jarvis, M.; Thornton, E. B.; Brown, J.; Fujimura, A.

    2012-12-01

    In the summer of 2011 we performed a field experiment in Carmel River State Beach, CA, at a time when the intermittent natural breaching of the ephemeral Carmel River occurred due to an unusually rainy period prior to the experiment associated with El Nino. At this time the river would fill the lagoon over the period of a number of days after which a breach would occur. This allowed us to document a number of breaches with unique pre- and post-breach topographic surveys, accompanying ocean and lagoon water elevations as well as extremely high flow (4m/s) velocities in the river mouth during the breaching event. The topographic surveys were obtained with a GPS-equipped backpack mounted on a walking human and show the evolution of the river breaching with a gradually widening and deepening river channel that cuts through the pre-existing beach and berm. The beach face is qualified as a steep with an average beach slope of 1:10 with significant reflection of the incident waves (MacMahan et al., 2012). The wave directions are generally shore normal as the waves refract over the deep canyon that is located offshore of the beach. The tide is mixed semi-diurnal with a range on the order of one meter. Breaching typically occurred during the low-low tide. Grain size is highly variable along the beach with layers of alternating fine and coarse material that could clearly be observed as the river exit channel was cutting through the beach. Large rocky outcroppings buried under the beach sand are also present along certain stretches of the beach controlling the depth of the breaching channel. The changes in the water level measured within the lagoon and the ocean side allows for an estimate of the volume flux associated with the breach as function of morphology, tidal elevation and wave conditions as well as an assessment of the conditions and mechanisms of breach closure, which occurred on the time scale of O(0.5 days). Exploratory model simulations will be presented at the

  18. Tsunami Bores in Kitakami River

    Science.gov (United States)

    Tolkova, Elena; Tanaka, Hitoshi

    2016-12-01

    The 2011 Tohoku tsunami entered the Kitakami river and propagated there as a train of shock waves, recorded with a 1-min interval at water level stations at Fukuchi, Iino, and the weir 17.2 km from the mouth, where the bulk of the wave was reflected back. The records showed that each bore kept its shape and identity as it traveled a 10.9-km-path Fukuchi-Iino-weir-Iino. Shock handling based on the cross-river integrated classical shock conditions was applied to reconstruct the flow velocity time histories at the measurement sites, to estimate inflow into the river at each site, to evaluate the wave heights of incident and reflected tsunami bores near the weir, and to estimate propagation speed of the individual bores. Theoretical predictions are verified against the measurements. We discuss experiences of exercising the shock conditions with actual tsunami measurements in the Kitakami river, and test applicability of the shallow-water approximation for describing tsunami bores with heights ranging from 0.3 to 4 m in a river segment with a depth of 3-4 m.

  19. Tsunami Bores in Kitakami River

    Science.gov (United States)

    Tolkova, Elena; Tanaka, Hitoshi

    2016-07-01

    The 2011 Tohoku tsunami entered the Kitakami river and propagated there as a train of shock waves, recorded with a 1-min interval at water level stations at Fukuchi, Iino, and the weir 17.2 km from the mouth, where the bulk of the wave was reflected back. The records showed that each bore kept its shape and identity as it traveled a 10.9-km-path Fukuchi-Iino-weir-Iino. Shock handling based on the cross-river integrated classical shock conditions was applied to reconstruct the flow velocity time histories at the measurement sites, to estimate inflow into the river at each site, to evaluate the wave heights of incident and reflected tsunami bores near the weir, and to estimate propagation speed of the individual bores. Theoretical predictions are verified against the measurements. We discuss experiences of exercising the shock conditions with actual tsunami measurements in the Kitakami river, and test applicability of the shallow-water approximation for describing tsunami bores with heights ranging from 0.3 to 4 m in a river segment with a depth of 3-4 m.

  20. The River Danube: An Examination of Navigation on the River

    Science.gov (United States)

    Cooper, R. W.

    One of the definitions of Navigation that gets little attention in this Institute is (Oxford English Dictionary), and which our French friends call La Navigation. I have always found this subject fascinating, and have previously navigated the Rivers Mekong, Irrawaddy, Hooghly, Indus, Shatt-al-Arab, Savannah and RhMainKanal (RMDK) and the River Danube, a distance of approximately 4000 km. This voyage has only recently become possible with the opening of the connecting RMDK at the end of 1992, but has been made little use of because of the civil war in the former Yugoslavia.

  1. Yukon foundation studies: Summary report, 1965

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The first chum salmon was caught on May 25 and were stilling catching them on August 23 three months later. Most of the migrants passed the study area in 2 or 3...

  2. BASEMAP, CITY OF FORT YUKON, ALASKA, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — This FEMA Framework Basemap dataset comprises the seven FGDC themes of geospatial data that are used by most GIS applications: cadastral, geodetic control,...

  3. Grays River Watershed Geomorphic Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Geist, David R

    2005-04-30

    This investigation, completed for the Pacific Northwest National Laboratory (PNNL), is part of the Grays River Watershed and Biological Assessment commissioned by Bonneville Power Administration under project number 2003-013-00 to assess impacts on salmon habitat in the upper Grays River watershed and present recommendations for habitat improvement. This report presents the findings of the geomorphic assessment and is intended to support the overall PNNL project by evaluating the following: The effects of historical and current land use practices on erosion and sedimentation within the channel network The ways in which these effects have influenced the sediment budget of the upper watershed The resulting responses in the main stem Grays River upstream of State Highway 4 The past and future implications for salmon habitat.

  4. Nelson River and Hudson Bay

    Science.gov (United States)

    2002-01-01

    Rivers that empty into large bodies of water can have a significant impact on the thawing of nearshore winter ice. This true-color Moderate Resolution Imaging Spectroradiometer (MODIS) image from May 18, 2001, shows the Nelson River emptying spring runoff from the Manitoba province to the south into the southwestern corner of Canada's Hudson Bay. The warmer waters from more southern latitudes hasten melting of ice near the shore, though some still remained, perhaps because in shallow coastal waters, the ice could have been anchored to the bottom. High volumes of sediment in the runoff turned the inflow brown, and the rim of the retreating ice has taken on a dirty appearance even far to the east of the river's entrance into the Bay. The sediment would have further hastened the melting of the ice because its darker color would have absorbed more solar radiation than cleaner, whiter ice. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  5. On the modelling of river delta formation

    NARCIS (Netherlands)

    Geleynse, N.

    2013-01-01

    This thesis presents approaches to the modelling of river delta formation. In particular, it provides results of numerical stratigraphic-morphodynamic modelling of river delta formation under various environmental forcings.

  6. Sprague River Oregon Water circa 1870

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the...

  7. Sprague River Oregon Centerline South Fork 2000

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the U.S....

  8. 2010 Hudson River Shallow Water Sediment Cores

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Hudson River Shallow Water Mapping project characterizes the bottom of the Hudson River Estuary in shallow water (<3 m). The characterization includes...

  9. 2010 Hudson River Shallow Water Sediment Grabs

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Hudson River Shallow Water Mapping project characterizes the bottom of the Hudson River Estuary in shallow water (<3 m). The characterization includes...

  10. Geomorphic Analysis - Trinity River Restoration Potential

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The goal of the Trinity River project is to identify the potential positive effects of large-scale restoration actions in a 63 kilometer reach of the Trinity River...

  11. Habitat Analysis - Trinity River Restoration Potential

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The goal of the Trinity River project is to identify the potential positive effects of large-scale restoration actions in a 63 kilometer reach of the Trinity River...

  12. Sprague River Oregon Centerline South Fork 1975

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the U.S....

  13. Sprague River Oregon Centerline South Fork 1968

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the U.S....

  14. Sprague River Oregon Centerline Sycan 1940

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the U.S....

  15. Sprague River Oregon Centerline North Fork 1968

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the U.S....

  16. Sprague River Oregon Centerline North Fork 1975

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the U.S....

  17. Minnesota Wild and Scenic River Districts

    Data.gov (United States)

    Minnesota Department of Natural Resources — District boundaries for wild, scenic, and recreational rivers designated under the Minnesota State Wild and Scenic Rivers Act. Includes portions of the Minnesota...

  18. Chemical - Elwha River Dam Removal Study

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study examines the ecosystem response of the Elwha River to the removal of the Elwha River dams. We will measure the following attributes of ecosystem response:...

  19. Biological - Elwha River Dam Removal Study

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study examines the ecosystem response of the Elwha River to the removal of the Elwha River dams. We will measure the following attributes of ecosystem response:...

  20. Sprague River Oregon Centerline Sycan 1968

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the U.S....

  1. Sprague River Oregon Centerline North Fork 2000

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the U.S....

  2. Colorado River Mile System, Tenths of Miles

    Data.gov (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...

  3. Physical - Elwha River Dam Removal Study

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study examines the ecosystem response of the Elwha River to the removal of the Elwha River dams. We will measure the following attributes of ecosystem response:...

  4. Sprague River Oregon Centerline South Fork 1940

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the U.S....

  5. Yellow River Delta Faces a Historic Opportunity

    Institute of Scientific and Technical Information of China (English)

    Li Zhen

    2010-01-01

    @@ China's State Council has endorsed the Development Plan of an Efficient Eco-Economic Zone at Yellow River Delta. The plan is meant to create a more ecologically sustainable economic zone along the river delta.

  6. Yellow River Delta Faces a Historic Opportunity

    Institute of Scientific and Technical Information of China (English)

    Li Zhen

    2011-01-01

    @@ China's State Council has endorsed the Development Plan of an Efficient Eco-Economic Zone at Yellow River Delta.The plan is meant to create a more ecologically sustainable economic zone along the river delta.

  7. Global Lake and River Ice Phenology Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Global Lake and River Ice Phenology Database contains freeze and thaw/breakup dates as well as other descriptive ice cover data for 865 lakes and rivers in the...

  8. Lower Duck River Mussel Survey and Inventory

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Duck River flows 290 miles through several major ecoregions before entering the impounded main stem Tennessee River at Sycamore Landing, Tennessee, adjacent to...

  9. Russian River Ice Thickness and Duration

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set consists of river ice thickness measurements, and beginning and ending dates for river freeze-up events from fifty stations in northern Russia. The...

  10. Sprague River Oregon Centerline circa 1870

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the U.S....

  11. Sprague River Oregon Centerline Sycan circa 1870

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Sprague River drains 4090 square kilometers in south-central Oregon before flowing into the Williamson River and upper Klamath Lake. In cooperation with the U.S....

  12. ALWAYS A RIVER - SUPPLEMENTAL ENVIRONMENTAL EDUCATION CURRICULUM ON THE OHIO RIVER AND WATER GRADES K - 12

    Science.gov (United States)

    This curriculum was developed as a significant component of the project, Always a River: The Ohio River and the American Experience, a six-state collaboration devoted to exploring the historical and cultural development of the Ohio River. The Always a River project is being joint...

  13. 75 FR 32351 - Drawbridge Operation Regulation; Taunton River, Fall River and Somerset, MA

    Science.gov (United States)

    2010-06-08

    ... River and Somerset, MA AGENCY: Coast Guard, DHS. ACTION: Notice of proposed rulemaking. SUMMARY: The...) Bridge at mile 1.8, between Fall River and Somerset, Massachusetts, to help relieve the bridge owner from... Taunton River between Fall River and Somerset, Massachusetts, has a vertical clearance in the...

  14. 78 FR 31457 - Drawbridge Operation Regulation; Taunton River, Fall River and Somerset, MA

    Science.gov (United States)

    2013-05-24

    .... USCG-2013-0291] RIN 1625-AA09 Drawbridge Operation Regulation; Taunton River, Fall River and Somerset..., mile 2.1, between Fall River and Somerset, Massachusetts. The bridge owner, Massachusetts Department of... between Somerset and Fall River, Massachusetts, has a vertical clearance of 60 feet at mean high water...

  15. 76 FR 71342 - Proposed CERCLA Administrative Cost Recovery Settlement; River Forest Dry Cleaners Site, River...

    Science.gov (United States)

    2011-11-17

    ... AGENCY Proposed CERCLA Administrative Cost Recovery Settlement; River Forest Dry Cleaners Site, River... proposed administrative settlement for recovery of past response costs concerning the River Forest Dry Cleaners site in River Forest, Cook County, Illinois with the following settling party: Edward...

  16. 77 FR 23658 - Six Rivers National Forest, Gasquet Ranger District, California, The Smith River National...

    Science.gov (United States)

    2012-04-20

    ... Smith River National Recreation Area Restoration and Motorized Travel Management Project AGENCY: Forest...-pacificsouthwest-six-rivers@fs.fed.us . Please insure that ``Smith River NRA Restoration and Motorized Travel... UARs totaling 80 miles. The project encompasses the Smith River NRA and Gasquet Ranger...

  17. Kentucky River and Tributaries. Upper Kentucky River Navigation Project. Volume 2. Public Involvement Record.

    Science.gov (United States)

    1980-11-01

    River and as a child , it was one of the greatest things to see the dredge boat come up the Kentucky River. Of course, this discourages river traffic...Portat as a tourist attraction Lock 145 had been neglete during Fr’anfo’ 5 Melodye Park was a the war years and were in very bad product o the river’s

  18. Columbia River Component Data Evaluation Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    C.S. Cearlock

    2006-08-02

    The purpose of the Columbia River Component Data Compilation and Evaluation task was to compile, review, and evaluate existing information for constituents that may have been released to the Columbia River due to Hanford Site operations. Through this effort an extensive compilation of information pertaining to Hanford Site-related contaminants released to the Columbia River has been completed for almost 965 km of the river.

  19. SIRIU RESERVOIR, BUZAU RIVER (ROMANIA

    Directory of Open Access Journals (Sweden)

    Daniel Constantin DIACONU

    2008-06-01

    Full Text Available Siriu reservoir, owes it`s creation to the dam built on the river Buzau, in the town which bears the same name. The reservoir has a hydro energetic role, to diminish the maximum flow and to provide water to the localities below. The partial exploitation of the lake, began in 1984; Since that time, the initial bed of the river began to accumulate large quantities of alluvia, reducing the retention capacity of the lake, which had a volume of 125 million m3. The changes produced are determined by many topographic surveys at the bottom of the lake.

  20. Setting targets in strategies for river restoration

    NARCIS (Netherlands)

    Pedroli, G.B.M.; Blust, de G.; Looy, van K.; Rooij, van S.A.M.

    2002-01-01

    Since about 90% of the natural floodplain area of rivers in Europe has been reclaimed and now lacks river dynamics, nature rehabilitation along rivers is of crucial importance for the restoration of their natural function. Flood protection, self-purification of surface water, groundwater recharge, s

  1. 33 CFR 117.300 - Manatee River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Manatee River. 117.300 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.300 Manatee River. The draw of the CSX Railroad Bridge across the Manatee River, mile 4.5 Bradenton, operates as follows: (a) The bridge is...

  2. The science and practice of river restoration

    Science.gov (United States)

    Wohl, Ellen; Lane, Stuart N.; Wilcox, Andrew C.

    2015-08-01

    River restoration is one of the most prominent areas of applied water-resources science. From an initial focus on enhancing fish habitat or river appearance, primarily through structural modification of channel form, restoration has expanded to incorporate a wide variety of management activities designed to enhance river process and form. Restoration is conducted on headwater streams, large lowland rivers, and entire river networks in urban, agricultural, and less intensively human-altered environments. We critically examine how contemporary practitioners approach river restoration and challenges for implementing restoration, which include clearly identified objectives, holistic understanding of rivers as ecosystems, and the role of restoration as a social process. We also examine challenges for scientific understanding in river restoration. These include: how physical complexity supports biogeochemical function, stream metabolism, and stream ecosystem productivity; characterizing response curves of different river components; understanding sediment dynamics; and increasing appreciation of the importance of incorporating climate change considerations and resiliency into restoration planning. Finally, we examine changes in river restoration within the past decade, such as increasing use of stream mitigation banking; development of new tools and technologies; different types of process-based restoration; growing recognition of the importance of biological-physical feedbacks in rivers; increasing expectations of water quality improvements from restoration; and more effective communication between practitioners and river scientists.

  3. The social side of river management

    NARCIS (Netherlands)

    Groot, de W.T.; Warner, J.F.

    2011-01-01

    River management faces many challenges world-wide including climate change, flood risks and the demand for more adaptive and 'ecosystem-based' systems. Instead of raising the dikes even higher, the new adage for river managers is to give the rivers more space to drain their waters. This in turn impl

  4. 77 FR 23120 - Special Local Regulations; Lowcountry Splash Open Water Swim, Wando River and Cooper River, Mount...

    Science.gov (United States)

    2012-04-18

    ... Swim, Wando River and Cooper River, Mount Pleasant, SC AGENCY: Coast Guard, DHS. ACTION: Temporary... Wando River and Cooper River in Mount Pleasant, South Carolina during the Lowcountry Splash, a 2.4 mile... the Lowcountry Splash, a 2.4 mile open water swim in the Wando River and Cooper River along...

  5. RiverCare: towards self-sustaining multifunctional rivers

    Science.gov (United States)

    Augustijn, Denie; Schielen, Ralph; Hulscher, Suzanne

    2014-05-01

    Rivers are inherently dynamic water systems involving complex interactions among hydrodynamics, morphology and ecology. In many deltas around the world lowland rivers are intensively managed to meet objectives like safety, navigation, hydropower and water supply. With the increasing pressure of growing population and climate change it will become even more challenging to reach or maintain these objectives and probably also more demanding from a management point of view. In the meantime there is a growing awareness that rivers are natural systems and that, rather than further regulation works, the dynamic natural processes should be better utilized (or restored) to reach the multifunctional objectives. Currently many integrated river management projects are initiated all over the world, in large rivers as well as streams. Examples of large scale projects in the Netherlands are 'Room for the River' (Rhine), the 'Maaswerken' (Meuse), the Deltaprogramme and projects originating from the European Water Framework Directive (WFD). These projects include innovative measures executed never before on this scale and include for example longitudinal training dams, side channels, removal of bank protection, remeandering of streams, dredging/nourishment and floodplain rehabilitation. Although estimates have been made on the effects of these measures for many of the individual projects, the overall effects on the various management objectives remains uncertain, especially if all projects are considered in connection. For all stakeholders with vested interests in the river system it is important to know how that system evolves at intermediate and longer time scales (10 to 100 years) and what the consequences will be for the various river functions. If the total, integrated response of the system can be predicted, the system may be managed in a more effective way, making optimum use of natural processes. In this way, maintenance costs may be reduced, the system remains more natural

  6. Profiling river surface velocities and volume flow estimation with bistatic UHF RiverSonde radar

    Science.gov (United States)

    Barrick, D.; Teague, C.; Lilleboe, P.; Cheng, R.; Gartner, J.; ,

    2003-01-01

    From the velocity profiles across the river, estimates of total volume flow for the four methods were calculated based on a knowledge of the bottom depth vs position across the river. It was found that the flow comparisons for the American River were much closer, within 2% of each other among all of the methods. Sources of positional biases and anomalies in the RiverSonde measurement patterns along the river were identified and discussed.

  7. 33 CFR 165.150 - New Haven Harbor, Quinnipiac River, Mill River.

    Science.gov (United States)

    2010-07-01

    ... River, Mill River. 165.150 Section 165.150 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... New Haven Harbor, Quinnipiac River, Mill River. (a) The following is a regulated navigation area: The... 303°T to point D at the west bank of the mouth of the Mill River 41°18′05″ N, 72°54′23″ W thence...

  8. A Review of Integrated River Basin Management for Sarawak River

    Directory of Open Access Journals (Sweden)

    Kuok K. Kuok

    2011-01-01

    Full Text Available Problem statement: Sarawak River was a life-sustaining water source for the residents in Kuching City and surrounding areas. Raw water is treated at Batu Kitang Water Treatment Plant (BKWTP that supplies more than 98% of the total water production in Kuching City. The raw water supply to BKWTP is not adequate to meet the ever increasing water demand. In order to overcome this problem, four projects had been implemented along Sarawak River for managing and securing water supply to BKWTP. Approach: These four projects are construction of 1.5m height storage weir across Sungai Sarawak Kiri river channel, Kuching Barrage and Shiplock, Bengoh Dam and Kuching Centralized Wastewater Management System (KCWMS. In 2005, 1.5 m height submersible weir was constructed across Sungai Sarawak Kiri channel for increasing the safe yield that can last until year 2010. Kuching Barrage and Shiplock were commissioned in 2000 as barrier to avoid the saline intrusion reaching upper catchment. 24 telemetry stations were installed along Sarawak River for monitoring and regulating the water level. This will preserve high quality water storage at upper catchment of Sarawak River. In year 2010, Bengoh Dam was constructed to ensure adequate raw water will be supplied to BKWTP for meeting the increasing water demand from 2010-2030. This reservoir will store 144 million m3 of fresh water covering reservoir area of 8.77km2. Beyond 2030, the water supply shall not depend solely on fresh water. Results: Black and grey water in Sarawak Catchment was treated through Kuching Centralized Wastewater Management System (KCWMS and recycled for daily used. Conclusion: The treated water that comply Standard A water quality, can distribute for domestic, industrial and irrigation used in nearest future. This will reduce the water demand solely on raw water and create a sustainable living in Kuching City. Beyond 2030, a few alternatives are also proposed for conserving and

  9. Stochastic modelling of river morphodynamics

    NARCIS (Netherlands)

    Van Vuren, B.G.

    2005-01-01

    Modern river management has to reconcile a number of functions, such as protection against floods and provision of safe and efficient navigation, floodplain agriculture, ecology and recreation. Knowledge on uncertainty in fluvial processes is important to make this possible, to design effective rive

  10. Modelling river history and evolution.

    Science.gov (United States)

    Coulthard, T J; Van de Wiel, M J

    2012-05-13

    Over the last few decades, a suite of numerical models has been developed for studying river history and evolution that is almost as diverse as the subject of river history itself. A distinction can be made between landscape evolution models (LEMs), alluvial architecture models, meander models, cellular models and computational fluid dynamics models. Although these models share some similarities, there also are notable differences between them, which make them more or less suitable for simulating particular aspects of river history and evolution. LEMs embrace entire drainage basins at the price of detail; alluvial architecture models simulate sedimentary facies but oversimplify flow characteristics; and computational fluid dynamics models have to assume a fixed channel form. While all these models have helped us to predict erosion and depositional processes as well as fluvial landscape evolution, some areas of prediction are likely to remain limited and short-term owing to the often nonlinear response of fluvial systems. Nevertheless, progress in model algorithms, computing and field data capture will lead to greater integration between these approaches and thus the ability to interpret river history more comprehensively.

  11. Arctic and subarctic environmental analyses utilizing ERTS-1 imagery. [permafrost sediment transport, snow cover, ice conditions, and water runoff in Alaska

    Science.gov (United States)

    Anderson, D. M.; Mckim, H. L.; Haugen, R. K.; Gatto, L. W.; Slaughter, C. W.; Marlar, T. L. (Principal Investigator)

    1973-01-01

    The author has identified the following significant results. Physiognomic landscape features were used as geologic and vegetative indicators in preparation of a surficial geology, vegetation, and permafrost map at a scale of 1:1 million using ERTS-1 band 7 imagery. The detail from this map compared favorably with USGS maps at 1:250,000 scale. Physical boundaries mapped from ERTS-1 imagery in combination with ground truth obtained from existing small maps and other sources resulted in improved and more detailed maps of permafrost terrain and vegetation for the same area. ERTS-1 imagery provides for the first time, a means of monitoring the following regional estuarine processes: daily and periodic surface water circulation patterns; changes in the relative sediment load of rivers discharging into the inlet; and, several local patterns not recognized before, such as a clockwise back eddy offshore from Clam Gulch and a counterclockwise current north of the Forelands. Comparison of ERTS-1 and Mariner imagery has revealed that the thermokarst depressions found on the Alaskan North Slope and polygonal patterns on the Yukon River Delta are possible analogs to some Martian terrain features.

  12. Health evaluation indicator system for urban landscape rivers, case study of the Bailianjing River in Shanghai

    Science.gov (United States)

    Wang, Juan; Wang, Yue; Yang, Haizhen; Lu, Zhibo; Xu, Xiaotian

    2010-11-01

    The River Bailianjing is an iconic landscape feature known to all residents in Pudong area and running through the Shanghai Expo 2010 Park. The river and its basin was a complex living ecosystem which supports a unique variety of flora and fauna several decades ago. However, as a result of unsuccessful pollution source control, sewage and first flow of the storm water is directly coming into the river in some catchment. The water quality of the river is seriously organically polluted now. The typical organic pollutants are COD, NH3-N, TN and TP, which cause the extinction of the water plants and aquatic. Furthermore, the artificial hard river banks isolate the river course and the land, which damaged the whole ecological system totally. The nature of the River Bailianjing and its history has resulted in many government departments and authorities and non government organizations having jurisdiction and/or an interest in the river's management. As a new tool to improve river management, the river health assessment has become the major focus of ecological and environmental science. Consequently, research on river health evaluation and its development on river management are of great theoretical and practical significance. In order to evaluate the healthy status of the River Bailianjing and prepare comprehensive scientific background data for the integrated river ecological rehabilitation planning, the health evaluation indicator system for River Bailianjing is brought forward. The indicator system has three levels: the first is target layer; the second is criteria layer, including five fields: water quality characteristics, hydrology characteristics, river morphology, biological characteristics and river scenic beauty; the third is an index layer, a total of 15 specific indicators included. Fuzzy AHP method is used to evaluate the target river's health status, and five grades are set up to describe it: healthy, sub health, marginal, unhealthy and pathological. The

  13. MICROPHYTOBENTHOS IN THE SUTLA RIVER

    Directory of Open Access Journals (Sweden)

    Marija Tomec

    2009-10-01

    Full Text Available The Sutla river is a river along Croatian/Slovenian border. Its length is about 91 km, out of which 89 km in Croatia. Microphytobenthos investigations have been performed at six locations along the Sutla river on Croatian territory. Samples were collected from specific areas of characteristic habitats. Beside sample collection, basic physico–chemical parameters were measured: water temperature, pH values and quantity of water dissolved oxygen. Water temperature changed depending on air temperature and the depth of the river, ranging from 5.1ºC to 6.3ºC. pH values were between 7.77 and 8.14, and dissolved oxygen concentrations (mg/L O2 at the six locations ranged between 8.6 mg/L and 14.9 mg/L. Quantitative microphytobenthos composition comprised 87 microphythic species belonging to the systematic groups of Bacteriophyta, Cyanobacteria and Chrysophyta (Bacillariophyceae and Xanthophyceae. The most numerous group were the diatoms or Bacillariophyceae (76 species or 88.3%, with dominance of the species of the genera Achnanthes, Cocconeis, Cymbella, Gomphonema, Navicula, Nitzschia and Surirella. The group Cyanobacteria was represented with relatively small number of species (9 species or 10%, with the dominance of filamentous algae belonging to the genus Phormidium. From the total number of the determined microphytobenthic species, 73 species or 84% were indicators of saprobity. Most of them were beta–mezosaprobic indicators. Based on the indicator values of determined microphytobenthic species at six investigated locations, P–B saprobity index was in the range from 1.8 to 2.0. These values suggested that the water at the investigated part of the Sutla river belonged to the second class of Croatian Water Quality Directive.

  14. HANFORD SITE RIVER CORRIDOR CLEANUP

    Energy Technology Data Exchange (ETDEWEB)

    BAZZELL, K.D.

    2006-02-01

    In 2005, the US Department of Energy (DOE) launched the third generation of closure contracts, including the River Corridor Closure (RCC) Contract at Hanford. Over the past decade, significant progress has been made on cleaning up the river shore that bordes Hanford. However, the most important cleanup challenges lie ahead. In March 2005, DOE awarded the Hanford River Corridor Closure Contract to Washington Closure Hanford (WCH), a limited liability company owned by Washington Group International, Bechtel National and CH2M HILL. It is a single-purpose company whose goal is to safely and efficiently accelerate cleanup in the 544 km{sup 2} Hanford river corridor and reduce or eliminate future obligations to DOE for maintaining long-term stewardship over the site. The RCC Contract is a cost-plus-incentive-fee closure contract, which incentivizes the contractor to reduce cost and accelerate the schedule. At $1.9 billion and seven years, WCH has accelerated cleaning up Hanford's river corridor significantly compared to the $3.2 billion and 10 years originally estimated by the US Army Corps of Engineers. Predictable funding is one of the key features of the new contract, with funding set by contract at $183 million in fiscal year (FY) 2006 and peaking at $387 million in FY2012. Another feature of the contract allows for Washington Closure to perform up to 40% of the value of the contract and subcontract the balance. One of the major challenges in the next few years will be to identify and qualify sufficient subcontractors to meet the goal.

  15. The river model of black holes

    CERN Document Server

    Hamilton, A J S; Hamilton, Andrew J. S.; Lisle, Jason P.

    2004-01-01

    This paper presents a new way to conceptualize stationary black holes, which we call the river model. The river model is mathematically sound, yet simple enough that the basic picture can be understood by non-experts. In the river model, space itself flows like a river through a flat background, while objects move through the river according to the rules of special relativity. In a spherical black hole, the river of space falls into the black hole at the Newtonian escape velocity, hitting the speed of light at the horizon. Inside the horizon, the river flows inward faster than light, carrying everything with it. We show that the river model works also for rotating (Kerr-Newman) black holes, though with a surprising twist. As in the spherical case, the river of space can be regarded as moving through a flat background. However, the river does not spiral inward, as one might have anticipated, but rather falls inward with no azimuthal swirl at all. Instead, the river has at each point not only a velocity but als...

  16. Research on the river function regionalization

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Objectives, principles, classification system, zoning method and procedure of river function region-alization were investigated systematically based on the present status of modern river regulation and function requirement. Considering the ecosystem continuity and river function integrality, a river is suggested to be divided into five function zones: ecological protection zone, habitat restoration zone, exploitation and utilization zone, buffer zone,and transition zone, based on the developed intensity and the function characteristics of the river. In this paper, not only the five function zones were described qualitatively, but also the quantitative examination method on how to identify their function zone types was given. A double-criterion partitioning scheme was proposed according to the functional zoning diagram constructed by the evaluation of the social and ecological function of rivers. Finally, the procedures of river function regionalization were shown.

  17. The influence of hook type, angler experience, and fish size on injury rates and the duration of capture in an Alaskan catch-and-release rainbow trout fishery

    Science.gov (United States)

    Meka, J.M.

    2004-01-01

    Owing to concerns about the high incidence of past hooking injuries in Alagnak River rainbow trout Oncorhynchus mykiss, fish were captured with spin- and fly-fishing gear with barbed and barbless circle and "J" hooks to determine gear types contributing to injury. Landing and hook removal times were measured for a portion of fish captured, and the anatomical hooking location, hooking scar locations, bleeding intensity, angler experience, and fish size were recorded for all captured fish. Approximately 62% of fish captured experienced at least one new hooking injury, and 29% of fish had at least one past hooking injury. Small fish sustained higher new injury and bleeding rates, but large fish had higher past injury rates. Injury rates were higher for barbed J hooks, barbed J hooks took longer to remove, and fish caught by spin-fishing were injured more frequently than fish caught by fly-fishing. Fewer fly-fishing-caught fish were injured using circle hooks, and circle hooks tended to hook fish in only one location, generally in the jaw. Barbed J hooks were more efficient at landing fish, and J hooks were more efficient at landing fish than circle hooks. Novice anglers injured proportionally more fish than experienced anglers, primarily during hook removal. Landing time was positively correlated with fish size, and experienced anglers took longer to land fish than novices because they captured larger fish. These results suggest that a reduction in hooking injuries may be achieved by using circle hooks as an alternative to J hooks and barbless J hooks to reduce injury and handling time, yet catch efficiency for both methods would be reduced. Although fish captured with barbless J hooks and circle hooks had fewer injuries, it is important to note that each hook type also caused significant injury, and angler education is recommended to promote proper hook removal techniques.

  18. Initial river test of a monostatic RiverSonde streamflow measurement system

    Science.gov (United States)

    Teague, C.C.; Barrick, D.E.; Lilleboe, P.M.; Cheng, R.T.; ,

    2003-01-01

    A field experiment was conducted on May 7-8, 2002 using a CODAR RiverSonde UHF radar system at Vernalis, California on the San Joaquin River. The monostatic radar configuration on one bank of the river, with the antennas looking both upriver and downriver, provided very high-quality data. Estimates of both along-river and cross-river surface current were generated using several models, including one based on normal-mode analysis. Along-river surface velocities ranged from about 0.6 m/s at the river banks to about 1.0 m/s near the middle of the river. Average cross-river surface velocities were 0.02 m/s or less.

  19. Mitochondrial DNA variation in chinook salmon and chum salmon detected by restriction enzyme analysis of polymerase chain reaction products

    Science.gov (United States)

    Cronin, M.; Spearman, R.; Wilmot, R.; Patton, J.; Bickman, J.

    1993-01-01

    We analyze intraspecific mitochondrial DNA variation in chinook salmon from drainages in the Yukon River, the Kenai River, and Oregon and California rivers; and chum salmon from the Yukon River and vancouver Island, and Washington rivers. For each species, three different portions of the mtDNA molecule were amplified seperately using the polymerase chain reaction and then digested with at least 19 restrictions enzymes. Intraspecific sequence divergences between haplotypes were less than 0.01 base subsitution per nucleotide. Nine chum salmon haplotypes were identified. Yukon River chum salmon stocks displayed more haplotypes (8) occurred in all areas. Seven chinook salmon haplotypes were identified. Four haplotypes occurred in the Yukon and Kenai rviers and four occured in the Oregon/California, with only one haplotype shared between the regions. Sample sizes were too small to quantify the degree of stock seperation among drainages, but the patterns of variation that we observed suggest utility of the technique in genetic stock identification.

  20. A comparison of ringed and bearded seal diet, condition and productivity between historical (1975-1984) and recent (2003-2012) periods in the Alaskan Bering and Chukchi seas

    Science.gov (United States)

    Crawford, Justin A.; Quakenbush, Lori T.; Citta, John J.

    2015-08-01

    Reductions in summer sea ice in the Chukchi and Beaufort seas are expected to affect what has been an ice-adapted marine food web in the Pacific Arctic. To determine whether recent decreases in sea ice have affected ice-associated marine predators (i.e., ringed, Pusa hispida, and bearded seals, Erignathus barbatus) in the Bering and Chukchi seas we compared diet, body condition, growth, productivity, and the proportion of pups harvested (an index of weaning success) for seals of each species harvested by 11 Alaskan villages during two periods; a historical (1975-1984) and a recent period (2003-2012). We also examined how changes in indices of seal health may be correlated with the reduction of sea ice characteristic of the recent period. For ringed seals ⩾1 year of age, the % frequency of occurrence (%FO) of Arctic cod (Boreogadus saida), walleye pollock (Gadus chalcogramma), rainbow smelt (Osmerus mordax), and Pacific herring (Clupea pallasi) increased from the historic to the recent period, while the %FO of invertebrates decreased for both pups and seals ⩾1 year of age. For bearded seals ⩾1 year of age, the %FO of Arctic cod, pricklebacks, and flatfish increased during the recent period, while the %FO of saffron cod (Eleginus gracilis) decreased for pups. Although invertebrates did not change overall for either age class, decreases occurred in 10 of 24 specific prey categories, for bearded seals ⩾1 year of age; only echiurids increased. The %FO of gastropods and bivalves increased for pups while isopods and one species of shrimp and crab decreased in occurrence. During the recent period ringed seals grew faster, had thicker blubber, had no change in pregnancy rate, matured 2 years earlier, and a larger proportion of pups was harvested than during the historical period. Correlations with spring ice concentration showed that the growth and blubber thickness of seals ⩾1 year of age, blubber thickness of pups, and the proportion of pups in the harvest all