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Sample records for alaskan yukon river

  1. 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.

  2. Yukon River King Salmon - Ichthyophonus Pilot Study

    Science.gov (United States)

    Kocan, R.M.; Hershberger, P.K.

    2001-01-01

    When king salmon enter the Yukon River on their spawning migration in mid June, over 25% of the population are infected with Ichthyophonus. The percent of infected fish remains relatively constant until the fish pass river mile 1,319 at Dawson, Y.T., then it drops to 13% when they reach river mile 1,745 at Whitehorse, Y.T. When the sexes are examined separately, slightly more females are infected than males (29% vs 22%). The percent of fish exhibiting clinical signs (diseased) is 2-3% when they enter the river, but increases to over 20% at river mile 715 near Tanana, AK. Disease prevalence within the population remains constant at >20% until fish pass Dawson, then the percent of diseased fish drops to <9% at Whitehorse. When the sexes are examined separately, male disease prevalence is highest at Tanana (22.6%) then gradually drops to just 12.9% at Whitehorse. Females however, continue to show an increase in disease prevalence peaking at river mile 1,081 near Circle, AK, at 36.4%, then dropping to just 5.3% at Whitehorse. Data on infection and disease collected from kings at Nenana on the Tanana River more closely resembles that seen at Whitehorse than the lower and middle Yukon River.

  3. Understanding the Complexities of Communicating Management Decisions on the Subsistence Use of Yukon River Salmon

    Science.gov (United States)

    Brooks, J. F.; Trainor, S.

    2017-12-01

    Over 20,000 residents in Alaska and Yukon Territory rely upon the Yukon River to provide them harvests of Pacific salmon each year. Salmon are a highly valued food resource and the practice of salmon fishing along the Yukon is deep rooted in local cultures and traditions. Potential future impacts of climate change on the health of Yukon River salmon stocks could be significant. Collaborative managerial processes which incorporate the viewpoints of subsistence stakeholders will be crucial in enabling communities and managerial institutions to adapt and manage these impacts. However, the massive extent of the Yukon River makes it difficult for communities rich with highly localized knowledge to situate themselves within a drainage-wide context of resource availability, and to fully understand the implications that management decisions may have for their harvest. Differences in salmon availability and abundance between the upper and lower Yukon, commercial vs. subsistence fishery interests, and enforcement of the international Pacific Salmon Treaty further complicate understanding and makes the topic of salmon as a subsistence resource a highly contentious issue. A map which synthesizes the presence and absence of Pacific salmon throughout the entire Yukon River drainage was requested by both subsistence fishers and natural resource managers in Alaska in order to help facilitate productive conversations about salmon management decisions. Interviews with Alaskan stakeholders with managerial, biological, and subsistence harvest backgrounds were carried out and a literature review was conducted in order to understand what such a map should and could accomplish. During the research process, numerous data gaps concerning the distribution of salmon along the Yukon River were discovered, and insights about the complexities involved in translating science when it is situated within a charged political, economic, and cultural context were revealed. Preliminary maps depicting

  4. 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...

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

    Science.gov (United States)

    Striegl, Robert G.; 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.

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

    Science.gov (United States)

    Toohey, Ryan C; Herman-Mercer, Nicole M.; Schuster, Paul F.; Mutter, Edda A.; Koch, Joshua C.

    2016-01-01

    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.

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

    International Nuclear Information System (INIS)

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

    2011-01-01

    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.

  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. Export of Nitrogen From the Yukon River Basin to the Bering Sea

    Science.gov (United States)

    Dornblaser, M. M.; Striegl, R. G.

    2005-12-01

    The US Geological Survey measured nitrogen export from the 831,400 km2 Yukon River basin during 2001-04 as part of a five year water quality study of the Yukon River and its major tributaries. Concentrations of NO2+NO3, NH4+DON, and particulate N were measured ~6 times annually during open water and once under ice cover at three locations on the Yukon River, and on the Porcupine and Tanana Rivers. Concentration and continuous flow data were used to generate daily and annual loads of N species. NH4 concentration was generally negligible when compared to DON concentration, allowing for comparison of the relative importance of DIN vs. DON export at various watershed scales. NO2 concentration was also small compared to NO3. At Pilot Station, the last site on the Yukon before it flows into the Yukon Delta and the Bering Sea, DIN, DON, and particulate N loads averaged 19.3 × 106 kg/yr, 52.6 × 106 kg/yr, and 39.1 × 106 kg/yr, respectively. Normalized for the watershed area at Pilot Station, corresponding N yields were 1.65, 4.52, and 3.35 mmol/m2/yr. DIN yield for the Yukon at Pilot Station is substantially less than the NO3 flux reported for tropical/temperate rivers such as the Amazon, the Yangtze, and the Mississippi. DIN yield in the upper Yukon River basin is similar to that of the Mackenzie and other arctic rivers, but increases substantially downstream. This is likely due to development around Fairbanks in the Tanana River basin. When compared to other headwater basins in the upper Yukon, the Tanana basin yields about four times more DIN and two times more particulate N, while DON yields are only slightly elevated.

  10. Climate-driven effects of fire on winter habitat for caribou in the Alaskan-Yukon Arctic

    Science.gov (United States)

    Gustine, David D.; Brinkman, Todd J.; Lindgren, Michael A.; Schmidt, Jennifer I.; Rupp, T. Scott; Adams, Layne G.

    2014-01-01

    Climatic warming has direct implications for fire-dominated disturbance patterns in northern ecosystems. A transforming wildfire regime is altering plant composition and successional patterns, thus affecting the distribution and potentially the abundance of large herbivores. Caribou (Rangifer tarandus) are an important subsistence resource for communities throughout the north and a species that depends on terrestrial lichen in late-successional forests and tundra systems. Projected increases in area burned and reductions in stand ages may reduce lichen availability within caribou winter ranges. Sufficient reductions in lichen abundance could alter the capacity of these areas to support caribou populations. To assess the potential role of a changing fire regime on winter habitat for caribou, we used a simulation modeling platform, two global circulation models (GCMs), and a moderate emissions scenario to project annual fire characteristics and the resulting abundance of lichen-producing vegetation types (i.e., spruce forests and tundra >60 years old) across a modeling domain that encompassed the winter ranges of the Central Arctic and Porcupine caribou herds in the Alaskan-Yukon Arctic. Fires were less numerous and smaller in tundra compared to spruce habitats throughout the 90-year projection for both GCMs. Given the more likely climate trajectory, we projected that the Porcupine caribou herd, which winters primarily in the boreal forest, could be expected to experience a greater reduction in lichen-producing winter habitats (−21%) than the Central Arctic herd that wintered primarily in the arctic tundra (−11%). Our results suggest that caribou herds wintering in boreal forest will undergo fire-driven reductions in lichen-producing habitats that will, at a minimum, alter their distribution. Range shifts of caribou resulting from fire-driven changes to winter habitat may diminish access to caribou for rural communities that reside in fire-prone areas.

  11. Climate-driven effects of fire on winter habitat for caribou in the Alaskan-Yukon Arctic.

    Directory of Open Access Journals (Sweden)

    David D Gustine

    Full Text Available Climatic warming has direct implications for fire-dominated disturbance patterns in northern ecosystems. A transforming wildfire regime is altering plant composition and successional patterns, thus affecting the distribution and potentially the abundance of large herbivores. Caribou (Rangifer tarandus are an important subsistence resource for communities throughout the north and a species that depends on terrestrial lichen in late-successional forests and tundra systems. Projected increases in area burned and reductions in stand ages may reduce lichen availability within caribou winter ranges. Sufficient reductions in lichen abundance could alter the capacity of these areas to support caribou populations. To assess the potential role of a changing fire regime on winter habitat for caribou, we used a simulation modeling platform, two global circulation models (GCMs, and a moderate emissions scenario to project annual fire characteristics and the resulting abundance of lichen-producing vegetation types (i.e., spruce forests and tundra >60 years old across a modeling domain that encompassed the winter ranges of the Central Arctic and Porcupine caribou herds in the Alaskan-Yukon Arctic. Fires were less numerous and smaller in tundra compared to spruce habitats throughout the 90-year projection for both GCMs. Given the more likely climate trajectory, we projected that the Porcupine caribou herd, which winters primarily in the boreal forest, could be expected to experience a greater reduction in lichen-producing winter habitats (-21% than the Central Arctic herd that wintered primarily in the arctic tundra (-11%. Our results suggest that caribou herds wintering in boreal forest will undergo fire-driven reductions in lichen-producing habitats that will, at a minimum, alter their distribution. Range shifts of caribou resulting from fire-driven changes to winter habitat may diminish access to caribou for rural communities that reside in fire-prone areas.

  12. Climate-driven effects of fire on winter habitat for caribou in the Alaskan-Yukon Arctic.

    Science.gov (United States)

    Gustine, David D; Brinkman, Todd J; Lindgren, Michael A; Schmidt, Jennifer I; Rupp, T Scott; Adams, Layne G

    2014-01-01

    Climatic warming has direct implications for fire-dominated disturbance patterns in northern ecosystems. A transforming wildfire regime is altering plant composition and successional patterns, thus affecting the distribution and potentially the abundance of large herbivores. Caribou (Rangifer tarandus) are an important subsistence resource for communities throughout the north and a species that depends on terrestrial lichen in late-successional forests and tundra systems. Projected increases in area burned and reductions in stand ages may reduce lichen availability within caribou winter ranges. Sufficient reductions in lichen abundance could alter the capacity of these areas to support caribou populations. To assess the potential role of a changing fire regime on winter habitat for caribou, we used a simulation modeling platform, two global circulation models (GCMs), and a moderate emissions scenario to project annual fire characteristics and the resulting abundance of lichen-producing vegetation types (i.e., spruce forests and tundra >60 years old) across a modeling domain that encompassed the winter ranges of the Central Arctic and Porcupine caribou herds in the Alaskan-Yukon Arctic. Fires were less numerous and smaller in tundra compared to spruce habitats throughout the 90-year projection for both GCMs. Given the more likely climate trajectory, we projected that the Porcupine caribou herd, which winters primarily in the boreal forest, could be expected to experience a greater reduction in lichen-producing winter habitats (-21%) than the Central Arctic herd that wintered primarily in the arctic tundra (-11%). Our results suggest that caribou herds wintering in boreal forest will undergo fire-driven reductions in lichen-producing habitats that will, at a minimum, alter their distribution. Range shifts of caribou resulting from fire-driven changes to winter habitat may diminish access to caribou for rural communities that reside in fire-prone areas.

  13. Lidar-based biomass assessment for the Yukon River Basin

    Science.gov (United States)

    Peterson, B.; Wylie, B. K.; Stoker, J.; Nossov, D.

    2010-12-01

    Climate change is expected to have a significant impact on high-latitude forests in terms of their ability to sequester carbon as expressed as pools of standing total biomass and soil organic matter. Above ground biomass is an important driver in ecosystem process models used to assess, predict, and understand climate change impacts. Therefore, it is of compelling interest to acquire accurate assessments of current biomass levels for these high-latitude forests, a particular challenge because of their vastness and remoteness. At this time, remote sensing is the only feasible method through which to acquire such assessments. In this study, the use of lidar data for estimating shrub and tree biomass for the Yukon Flats region of Alaska’s Yukon River Basin (YRB) is demonstrated. The lidar data were acquired in the late summer and fall of 2009 as were an initial set of field sampling data collected for training and validation purposes. The 2009 field campaigns were located near Canvasback Lake and Boot Lake in the YRB. Various tallies of biomass were calculated from the field data using allometric equations (Bond-Lamberty et al. 2002, Yarie et al. 2007, Mack et al. 2008). Additional field data were also collected during two 2010 field campaigns at different locations in the Yukon Flats. Linear regressions have been developed based on field-based shrub and tree biomass and various lidar metrics of canopy height calculated for the plots (900 m^2). A multiple linear regression performed at the plot level resulted in a strong relationship (R^2=0.88) between observed and predicted biomass at the plot level. The coefficients for this regression were used to generate a shrub and tree biomass map for the entire Yukon Flats study area covered by lidar. This biomass map will be evaluated using additional field data collected in 2010 as well as other remote sensing data sources. Furthermore, additional lidar metrics (e.g. height of median energy) are being derived from the raw

  14. Behavior and reproductive success of Rock Sandpipers breeding on the Yukon-Kuskokwim River Delta, Alaska

    NARCIS (Netherlands)

    Johnson, Matthew; Conklin, J.R.; Johnson, Branden; McCaffery, Brian J.; Haig, Susan M.; Walters, Jeffrey R.

    2009-01-01

    We studied Rock Sandpiper (Calidris ptilocnemis) breeding behavior and monitored reproductive success from 1998 to 2005 on the Yukon-Kuskokwim River Delta, Alaska, USA. We banded 24 adults and monitored 45 nests. Annual return rate of adults ranged between 67 and 100%. Six pairs of Rock Sandpipers

  15. Mapping Soil Carbon in the Yukon Kuskokwim River Delta Alaska

    Science.gov (United States)

    Natali, S.; Fiske, G.; Schade, J. D.; Mann, P. J.; Holmes, R. M.; Ludwig, S.; Melton, S.; Sae-lim, N.; Jardine, L. E.; Navarro-Perez, E.

    2017-12-01

    Arctic river deltas are hotspots for carbon storage, occupying 10% of carbon stored in arctic permafrost. The Yukon Kuskokwim (YK) Delta, Alaska is located in the lower latitudinal range of the northern permafrost region in an area of relatively warm permafrost that is particularly vulnerable to warming climate. Active layer depths range from 50 cm on peat plateaus to >100 cm in wetland and aquatic ecosystems. The size of the soil organic carbon pool and vulnerability of the carbon in the YK Delta is a major unknown and is critically important as climate warming and increasing fire frequency may make this carbon vulnerable to transport to aquatic and marine systems and the atmosphere. To characterize the size and distribution of soil carbon pools in the YK Delta, we mapped the land cover of a 1910 km2 watershed located in a region of the YK Delta that was impacted by fire in 2015. The map product was the result of an unsupervised classification using the Weka K Means clustering algorithm implemented in Google's Earth Engine. Inputs to the classification were Worldview2 resolution optical imagery (1m), Arctic DEM (5m), and Sentinel 2 level 1C multispectral imagery, including NDVI, (10 m). We collected 100 soil cores (0-30 cm) from sites of different land cover and landscape position, including moist and dry peat plateaus, high and low intensity burned plateaus, fens, and drained lakes; 13 lake sediment cores (0-50 cm); and 20 surface permafrost cores (to 100 cm) from burned and unburned peat plateaus. Active layer and permafrost soils were analyzed for organic matter content, soil moisture content, and carbon and nitrogen pools (30 and 100 cm). Soil carbon content varied across the landscape; average carbon content values for lake sediments were 12% (5- 17% range), fens 26% (9-44%), unburned peat plateaus 41% (34-44%), burned peat plateaus 19% (7-34%). These values will be used to estimate soil carbon pools, which will be applied to the spatial extent of each

  16. Differences in Ichthyophonus prevalence and infection severity between upper Yukon River and Tanana River chinook salmon, Oncorhynchus tshawytscha (Walbaum), stocks.

    Science.gov (United States)

    Kocan, R; Hershberger, P

    2006-08-01

    Two genetically distinct populations of chinook salmon, Oncorhynchus tshawytscha (Walbaum), were simultaneously sampled at the confluence of the Yukon and Tanana rivers in 2003. Upper Yukon-Canadian fish had significantly higher infection prevalence as well as more severe infections (higher parasite density in heart tissue) than the lower Yukon-Tanana River fish. Both populations had migrated the same distance from the mouth of the Yukon River at the time of sampling but had significantly different distances remaining to swim before reaching their respective spawning grounds. Multiple working hypotheses are proposed to explain the differences between the two stocks: (1) the two genetically distinct populations have different inherent resistance to infection, (2) genetically influenced differences in feeding behaviour resulted in temporal and/or spatial differences in exposure, (3) physiological differences resulting from different degrees of sexual maturity influenced the course of disease, and (4) the most severely infected Tanana River fish either died en route or fatigued and were unable to complete their migration to the Tanana River, thus leaving a population of apparently healthier fish.

  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. 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.

  19. Transport of Water, Carbon, and Sediment Through the Yukon River Basin

    Science.gov (United States)

    Brabets, Timothy P.; Schuster, Paul F.

    2008-01-01

    INTRODUCTION In 2001, the U.S. Geological Survey (USGS) began a water-quality study of the Yukon River. The Yukon River Basin (YRB), which encompasses 330,000 square miles in northwestern Canada and central Alaska (fig. 1), is one of the largest and most diverse ecosystems in North America. The Yukon River is more than 1,800 miles long and is one of the last great uncontrolled rivers in the world, and is essential to the eastern Bering Sea and Chukchi Sea ecosystems, providing freshwater runoff, sediments, and nutrients (Brabets and others, 2000). Despite its remoteness, recent studies (Hinzman and others, 2005; Walvoord and Striegl, 2007) indicate the YRB is changing. These changes likely are in response to a warming trend in air temperature of 1.7i??C from 1951 to 2001 (Hartmann and Wendler, 2005). As a result of this warming trend, permafrost is thawing in the YRB, ice breakup occurs earlier on the main stem of the Yukon River and its tributaries, and timing of streamflow and movement of carbon and sediment through the basin is changing (Hinzman and others, 2005; Walvoord and Striegl, 2007). One of the most striking characteristics in the YRB is its seasonality. In the YRB, more than 75 percent of the annual streamflow runoff occurs during a five month period, May through September. This is important because streamflow determines when, where, and how much of a particular constituent will be transported. As an example, more than 95 percent of all sediment transported during an average year also occurs during this period (Brabets and others, 2000). During the other 7 months, streamflow, concentrations of sediment and other water-quality constituents are low and little or no sediment transport occurs in the Yukon River and its tributaries. Streamflow and water-quality data have been collected at more than 50 sites in the YRB (Dornblaser and Halm, 2006; Halm and Dornblaser, 2007). Five sites have been sampled more than 30 times and others have been sampled twice

  20. Impact of Ichthyophonus infection on spawning success of Yukon River Chinook salmon Oncorhynchus tshawytscha.

    Science.gov (United States)

    Hamazaki, Toshihide; Kahler, Eryn; Borba, Bonnie M; Burton, Tamara

    2013-11-06

    We examined the impacts of Ichthyophonus infection on spawning success of Yukon River Chinook salmon Oncorhynchus tshawytscha at spawning grounds of the Chena and Salcha Rivers, Alaska, USA. During the period 2005 to 2006, 1281 salmon carcasses (628 male, 652 female) were collected throughout the spawning season and from the entire spawning reaches of the Chena and Salcha Rivers. For each fish, infection status was determined by culture method and visual inspection of lesions of heart tissue as uninfected (culture negative), infected without lesions (culture positive with no visible lesions), and infected with lesions (culture positive with visible lesions), and spawning status was determined by visually inspecting the percentage of gametes remaining as full-spawned (50%). Among the 3 groups, the proportion of full-spawned (i.e. spawning success) females was lower for those infected without lesions (69%) than those uninfected (87%) and infected with lesions (86%), but this did not apply to males (uninfected 42%, infected without lesions 38%, infected with lesions 41%). At the population level, the combined (infected and uninfected) proportion of female spawning success was 86%, compared to 87% when all females were assumed uninfected. These data suggest that while Ichthyophonus infection slightly reduces spawning success of infected females, its impact on the spawning population as a whole appears minimal.

  1. The Indigenous Observation Network: Collaborative, Community-Based Monitoring in the Yukon River Basin

    Science.gov (United States)

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

    2017-12-01

    The Indigenous Observation Network (ION) is a collaborative Community-Based Monitoring (CBM) program with both permafrost and water-quality monitoring components operating in the Yukon River Basin (YRB) of Alaska and Canada. ION is jointly facilitated by the Yukon River Inter-Tribal Watershed Council (YRITWC), an indigenous non-profit organization, and the US Geological Survey (USGS), a federal agency. The YRB is the fourth largest drainage basin in North America encompassing 855,000 square kilometers in northwestern Canada and central Alaska and is essential to the ecosystems of the Bering and Chuckchi Seas. Water is also fundamental to the subsistence and culture of the 76 Tribes and First Nations that live in the YRB providing sustenance in the form of drinking water, fish, wildlife, and vegetation. Despite the ecological and cultural significance of the YRB, the remote geography of sub-Arctic and Arctic Alaska and Canada make it difficult to collect scientific data in these locations and led to a lack of baseline data characterizing this system until recently. In response to community concerns about the quality of the YR and a desire by USGS scientists to create a long term water-quality database, the USGS and YRITWC collaborated to create ION in 2005. Surface water samples are collected by trained community technicians from Tribal Environmental Programs or First Nation Lands and Resources staff from over 35 Alaska Native Tribes and First Nations that reside along the YR and/or one of the major tributaries. Samples are analyzed at USGS laboratories in Boulder, CO and results are disseminated to participating YRB communities and the general public. This presentation will focus on the factors that have enabled the longevity and success of this program over the last decade, as well as the strategies ION uses to ensure the credibility of the data collected by community members and best practices that have facilitated the collection of surface water data in remote

  2. Geomorphic Controls on Floodplain Soil Organic Carbon in the Yukon Flats, Interior Alaska, From Reach to River Basin Scales

    Science.gov (United States)

    Lininger, K. B.; Wohl, E.; Rose, J. R.

    2018-03-01

    Floodplains accumulate and store organic carbon (OC) and release OC to rivers, but studies of floodplain soil OC come from small rivers or small spatial extents on larger rivers in temperate latitudes. Warming climate is causing substantial change in geomorphic process and OC fluxes in high latitude rivers. We investigate geomorphic controls on floodplain soil OC concentrations in active-layer mineral sediment in the Yukon Flats, interior Alaska. We characterize OC along the Yukon River and four tributaries in relation to geomorphic controls at the river basin, segment, and reach scales. Average OC concentration within floodplain soil is 2.8% (median = 2.2%). Statistical analyses indicate that OC varies among river basins, among planform types along a river depending on the geomorphic unit, and among geomorphic units. OC decreases with sample depth, suggesting that most OC accumulates via autochthonous inputs from floodplain vegetation. Floodplain and river characteristics, such as grain size, soil moisture, planform, migration rate, and riverine DOC concentrations, likely influence differences among rivers. Grain size, soil moisture, and age of surface likely influence differences among geomorphic units. Mean OC concentrations vary more among geomorphic units (wetlands = 5.1% versus bars = 2.0%) than among study rivers (Dall River = 3.8% versus Teedrinjik River = 2.3%), suggesting that reach-scale geomorphic processes more strongly control the spatial distribution of OC than basin-scale processes. Investigating differences at the basin and reach scale is necessary to accurately assess the amount and distribution of floodplain soil OC, as well as the geomorphic controls on OC.

  3. 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.

  4. 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.

  5. Effects of disturbance and climate change on ecosystem performance in the Yukon River Basin boreal forest

    Science.gov (United States)

    Wylie, Bruce K.; Rigge, Matthew B.; Brisco, Brian; Mrnaghan, Kevin; Rover, Jennifer R.; Long, Jordan

    2014-01-01

    A warming climate influences boreal forest productivity, dynamics, and disturbance regimes. We used ecosystem models and 250 m satellite Normalized Difference Vegetation Index (NDVI) data averaged over the growing season (GSN) to model current, and estimate future, ecosystem performance. We modeled Expected Ecosystem Performance (EEP), or anticipated productivity, in undisturbed stands over the 2000–2008 period from a variety of abiotic data sources, using a rule-based piecewise regression tree. The EEP model was applied to a future climate ensemble A1B projection to quantify expected changes to mature boreal forest performance. Ecosystem Performance Anomalies (EPA), were identified as the residuals of the EEP and GSN relationship and represent performance departures from expected performance conditions. These performance data were used to monitor successional events following fire. Results suggested that maximum EPA occurs 30–40 years following fire, and deciduous stands generally have higher EPA than coniferous stands. Mean undisturbed EEP is projected to increase 5.6% by 2040 and 8.7% by 2070, suggesting an increased deciduous component in boreal forests. Our results contribute to the understanding of boreal forest successional dynamics and its response to climate change. This information enables informed decisions to prepare for, and adapt to, climate change in the Yukon River Basin forest.

  6. 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

  7. Assessing the accuracy of a polymerase chain reaction test for Ichthyophonus hoferi in Yukon River Chinook salmon Oncorhynchus tshawytscha.

    Science.gov (United States)

    Whipps, Christopher M; Burton, Tamara; Watral, Virginia G; St-Hilaire, Sophie; Kent, Michael L

    2006-01-30

    Ichthyophonus hoferi Plehn & Mulsow, 1911, is a cosmopolitan, protistan pathogen of marine fishes. It is prevalent in mature returning Chinook salmon Oncorhynchus tshawytscha in the Yukon River watershed, and may be associated with prespawning mortality. We developed and evaluated a polymerase chain reaction (PCR) test for I. hoferi using primers specific to the parasite's small subunit rDNA. The test has a minimum detection limit of approximately 10(-5) parasite spores per reaction and does not cross-react with the closely related salmon parasites Dermocystidium salmonis or Sphaerothecum destruens. Sensitivity and specificity of the PCR test used on somatic muscle and heart tissue for detecting infected fish were determined using 334 Chinook salmon collected from the Yukon River at 2 locations (Tanana and Emmonak) in 2003 and 2004. The true infection status of the fish was determined by testing somatic muscle, heart and kidney tissue using histological evaluation, culture, and PCR. The severity of infection was grouped into 2 categories, light and heavy infection. The probability of detecting a heavily infected fish (sensitivity of the test) was generally much higher than the probability of detecting light infection, suggesting that more than one tissue and/or method should be used to accurately detect light or early infection by I. hoferi. The probability of correctly identifying a negative fish (specificity of the test) was always greater than 94% regardless of the tissue used, infection severity, sampling site or year of collection.

  8. Recent changes in spring snowmelt timing in the Yukon River basin detected by passive microwave satellite data

    Directory of Open Access Journals (Sweden)

    K. A. Semmens

    2013-06-01

    Full Text Available Spring melt is a significant feature of high latitude snowmelt dominated drainage basins influencing hydrological and ecological processes such as snowmelt runoff and green-up. Melt duration, defined as the transition period from snowmelt onset until the end of the melt refreeze, is characterized by high diurnal amplitude variations (DAV where the snowpack is melting during the day and refreezing at night, after which the snowpack melts constantly until depletion. Determining trends for this critical period is necessary for understanding how the Arctic is changing with rising temperatures and provides a baseline from which to assess future change. To study this dynamic period, brightness temperature (Tb data from the Special Sensor Microwave Imager (SSM/I 37 V-GHz frequency from 1988 to 2010 were used to assess snowmelt timing trends for the Yukon River basin, Alaska/Canada. Annual Tb and DAV for 1434 Equal-Area Scalable Earth (EASE-Grid pixels (25 km resolution were processed to determine melt onset and melt refreeze dates from Tb and DAV thresholds previously established in the region. Temporal and spatial trends in the timing of melt onset and melt refreeze, and the duration of melt were analyzed for the 13 sub-basins of the Yukon River basin with three different time interval approaches. Results show a lengthening of the melt period for the majority of the sub-basins with a significant trend toward later end of melt refreeze after which the snowpack melts day and night leading to snow clearance, peak discharge, and green-up. Earlier melt onset trends were also found in the higher elevations and northernmost sub-basins (Porcupine, Chandalar, and Koyukuk rivers. Latitude and elevation displayed the dominant controls on melt timing variability and spring solar flux was highly correlated with melt timing in middle (∼600–1600 m elevations.

  9. Environmental Assessment for the Expansion of the Yukon Measurement and Debriefing System in the Fox and Yukon MOAs

    Science.gov (United States)

    2006-05-01

    River, Porcupine River, Chandalar River, and the upper portion of the Yukon River. The southern portion of the area is drained by the Fortymile River...physiographic features in the central 17 EA for Expansion of YMDS April2006 portion are the Porcupine Plateau and the Yukon Flats. The Yukon Flats...mile. The Fortymile caribou herd utilizes the surrounding area as its principle winter range. Since 1995, the Fortymile caribou herd has increased

  10. 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.

  11. Dissolved organic matter composition of winter flow in the Yukon River basin: Implications of permafrost thaw and increased groundwater discharge

    Science.gov (United States)

    O'Donnell, Jonathan A.; Aiken, George R.; Walvoord, Michelle Ann; Butler, Kenna D.

    2012-01-01

    Groundwater discharge to rivers has increased in recent decades across the circumpolar region and has been attributed to thawing permafrost in arctic and subarctic watersheds. Permafrost-driven changes in groundwater discharge will alter the flux of dissolved organic carbon (DOC) in rivers, yet little is known about the chemical composition and reactivity of dissolved organic matter (DOM) of groundwater in permafrost settings. Here, we characterize DOM composition of winter flow in 60 rivers and streams of the Yukon River basin to evaluate the biogeochemical consequences of enhanced groundwater discharge associated with permafrost thaw. DOC concentration of winter flow averaged 3.9 ± 0.5 mg C L−1, yet was highly variable across basins (ranging from 20 mg C L−1). In comparison to the summer-autumn period, DOM composition of winter flow had lower aromaticity (as indicated by specific ultraviolet absorbance at 254 nm, or SUVA254), lower hydrophobic acid content, and a higher proportion of hydrophilic compounds (HPI). Fluorescence spectroscopy and parallel factor analysis indicated enrichment of protein-like fluorophores in some, but not all, winter flow samples. The ratio of DOC to dissolved organic nitrogen, an indicator of DOM biodegradability, was positively correlated with SUVA254 and negatively correlated with the percentage of protein-like compounds. Using a simple two-pool mixing model, we evaluate possible changes in DOM during the summer-autumn period across a range of conditions reflecting possible increases in groundwater discharge. Across three watersheds, we consistently observed decreases in DOC concentration and SUVA254 and increases in HPI with increasing groundwater discharge. Spatial patterns in DOM composition of winter flow appear to reflect differences in the relative contributions of groundwater from suprapermafrost and subpermafrost aquifers across watersheds. Our findings call for more explicit consideration of DOC loss and stabilization

  12. 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

  13. Effect of Ichthyophonus on blood plasma chemistry of spawning Chinook salmon and their resulting offspring in a Yukon River tributary.

    Science.gov (United States)

    Floyd-Rump, T P; Horstmann-Dehn, L A; Atkinson, S; Skaugstad, C

    2017-01-24

    Ichthyophonus is a protozoan parasite of Alaska Chinook salmon Oncorhynchus tshawytscha. In this study, we determined whether spawning Chinook salmon in the Yukon River drainage exhibited a measurable stress response (i.e. elevated plasma cortisol concentrations) and detectable changes in selected blood plasma chemistry parameters when infected with Ichthyophonus. The resulting alevin were also analyzed for any differences in blood plasma chemistry caused by parental infection with Ichthyophonus. In 2010, 2011, and 2012, spawning adult Chinook salmon were collected from the Salcha River, Alaska, USA, and the prevalence of Ichthyophonus in these fish was 7.8, 6.3, and 8.3%, respectively. Fish with no clinical signs of Ichthyophonus and Ichthyophonus-positive parents were cross-fertilized to investigate potential second-generation effects as a result of Ichthyophonus infection. We found no significant difference in cortisol concentrations in blood plasma between Ichthyophonus-positive and -negative adults or between alevin from Ichthyophonus-positive and -negative parents. There were no significant differences in blood plasma parameters (e.g. alanine aminotransferase, creatine kinase, glucose) of Ichthyophonus-negative and -positive adults, with the exception of aspartate aminotransferase, which was significantly higher in plasma of Ichthyophonus-negative adults. All clinical chemistry parameters for alevin resulting from both Ichthyophonus-negative and -positive parents were not significantly different. Based on this study, which has a limited sample size and low prevalence of Ichthyophonus, offspring of Chinook salmon appear to suffer no disadvantage as a result of Ichthyophonus infection in their parents on the Salcha River.

  14. 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, Robert 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.

  15. Impacts of fire on nitrogen cycling in aquatic and terrestrial ecosystems in the Yukon-Kuskokwim River Delta, AK

    Science.gov (United States)

    Schade, J. D.; Jardine, L. E.; Bristol, E. M.; Navarro-Perez, E.; Melton, S.; Jimmie, J. A.; Natali, S.; Mann, P. J.; Holmes, R. M.

    2017-12-01

    Global climate change is having a disproportionate impact on northern high latitudes, including rapid increases in temperature, changes in precipitation, and increasing fire frequency and severity. Wildfires have been shown to strongly influence ecosystem processes through acceleration of permafrost thaw and increased nitrogen (N) availability, the effects of which may increase gaseous loss of carbon (C) to the atmosphere, increase primary production by alleviating N limitation, or both. The extent of these fire impacts has not been well-documented in the Arctic, particularly in areas of discontinuous permafrost. In 2015, the Yukon-Kuskokwim River Delta (YK Delta) in southwestern Alaska experienced the largest fire season in recorded history, providing an opportunity to study wildfire impacts on an area particularly vulnerable to permafrost thaw. Our objectives were to study the impacts of these fires on nitrogen availability in a range of land cover classes, including peat plateaus, channel fens, and aquatic ecosystems distributed across the landscapes. We sampled soils from several vegetation patches on burned and unburned peat plateaus, and soil and surface waters from fens, small ponds, and streams downslope of these sites. All water samples were filtered through GFF filters in the field. Soils were transported frozen to the Woods Hole Research Center and extracted in KCl. All water samples and extracts were analyzed for NH4 and NO3 concentrations. We found substantially higher concentrations of extractable NH4 in burned soils, but very little extractable NO3 in either burned or unburned soils. Water samples also showed higher NH4 in aquatic ecosystems in burned watersheds, but, in contrast to soils, showed relatively high NO3 concentrations, particularly in waters from lower landscape positions. Overall, aquatic ecosystems exhibited higher NO3: NH4 ratios than soil extractions, and increasing NO3: NH4 downslope. These results suggest significant export of

  16. PCR testing can be as accurate as culture for diagnosis of Ichthyophonus hoferi in Yukon River Chinook salmon Oncorhynchus tshawytscha .

    Science.gov (United States)

    Hamazaki, Toshihide; Kahler, Eryn; Borba, Bonnie M; Burton, Tamara

    2013-07-09

    We evaluated the comparability of culture and PCR tests for detecting Ichthyophonus in Yukon River Chinook salmon Oncorhynchus tshawytscha from field samples collected at 3 locations (Emmonak, Chena, and Salcha, Alaska, USA) in 2004, 2005, and 2006. Assuming diagnosis by culture as the 'true' infection status, we calculated the sensitivity (correctly identifying fish positive for Ichthyophonus), specificity (correctly identifying fish negative for Ichthyophonus), and accuracy (correctly identifying both positive and negative fish) of PCR. Regardless of sampling locations and years, sensitivity, specificity, and accuracy exceeded 90%. Estimates of infection prevalence by PCR were similar to those by culture, except for Salcha 2005, where prevalence by PCR was significantly higher than that by culture (p < 0.0001). These results show that the PCR test is comparable to the culture test for diagnosing Ichthyophonus infection.

  17. 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.

  18. 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

    2013-01-01

    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.

  19. Accumulated state assessment of the Yukon River watershed: part II quantitative effects-based analysis integrating Western science and traditional ecological knowledge.

    Science.gov (United States)

    Dubé, Monique G; Wilson, Julie E; Waterhouse, Jon

    2013-07-01

    This article is the second in a 2-part series assessing the accumulated state of the transboundary Yukon River (YR) basin in northern Canada and the United States. The determination of accumulated state based on available long-term (LT) discharge and water quality data is the first step in watershed cumulative effect assessment in the absence of sufficient biological monitoring data. Long-term trends in water quantity and quality were determined and a benchmark against which to measure change was defined for 5 major reaches along the YR for nitrate, total and dissolved organic carbon (TOC and DOC, respectively), total phosphate (TP), orthophosphate, pH, and specific conductivity. Deviations from the reference condition were identified as "hot moments" in time, nested within a reach. Significant increasing LT trends in discharge were found on the Canadian portion of the YR. There were significant LT decreases in nitrate, TOC, and TP at the Headwater reach, and significant increases in nitrate and specific conductivity at the Lower reach. Deviations from reference condition were found in all water quality variables but most notably during the ice-free period of the YR (May-Sept) and in the Lower reach. The greatest magnitudes of outliers were found during the spring freshet. This study also incorporated traditional ecological knowledge (TEK) into its assessment of accumulated state. In the summer of 2007 the YR Inter Tribal Watershed Council organized a team of people to paddle down the length of the YR as part of a "Healing Journey," where both Western Science and TEK paradigms were used. Water quality data were continuously collected and stories were shared between the team and communities along the YR. Healing Journey data were compared to the LT reference conditions and showed the summer of 2007 was abnormal compared to the LT water quality. This study showed the importance of establishing a reference condition by reach and season for key indicators of water

  20. Comparison of caribou physical characteristics from Yukon and neighboring caribou herds

    Directory of Open Access Journals (Sweden)

    David A. Gauthier

    1986-06-01

    Full Text Available Data on seven external body measurements of caribou from six woodland and two barren-ground caribou herds from Yukon, Alaska, Alberta and British Columbia were compared. Comparisons between females in the fall and winter and mature males in the fall revealed that (1 barren-ground Porcupine caribou were consistently smaller than caribou from other herds, (2 British Columbia and Alberta caribou tended to be larger than Yukon caribou, or the Alaskan caribou studied, (3 central Yukon caribou were intermediate in body size, (4 no difference was found between Yukon «mountain» and «woodland» type caribou in body size, and (5 the barren-ground Fortymile caribou were more similar in physical characteristics to Yukon woodland or mountain caribou than to those of the barren-ground Porcupine herd. These data support Banfield's (1961 view of a gradient of decreasing physical size from the northern British Columbia — Alberta herds through the Yukon mountain or woodland herds to the northern barren-ground herds.

  1. 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.

  2. 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.

  3. Remote measurement of surface-water velocity using infrared videography and PIV: a proof-of-concept for Alaskan rivers

    Science.gov (United States)

    Kinzel, Paul J.; Legleiter, Carl; Nelson, Jonathan M.; Conaway, Jeffrey S.

    2017-01-01

    Thermal cameras with high sensitivity to medium and long wavelengths can resolve features at the surface of flowing water arising from turbulent mixing. Images acquired by these cameras can be processed with particle image velocimetry (PIV) to compute surface velocities based on the displacement of thermal features as they advect with the flow. We conducted a series of field measurements to test this methodology for remote sensing of surface velocities in rivers. We positioned an infrared video camera at multiple stations across bridges that spanned five rivers in Alaska. Simultaneous non-contact measurements of surface velocity were collected with a radar gun. In situ velocity profiles were collected with Acoustic Doppler Current Profilers (ADCP). Infrared image time series were collected at a frequency of 10Hz for a one-minute duration at a number of stations spaced across each bridge. Commercial PIV software used a cross-correlation algorithm to calculate pixel displacements between successive frames, which were then scaled to produce surface velocities. A blanking distance below the ADCP prevents a direct measurement of the surface velocity. However, we estimated surface velocity from the ADCP measurements using a program that normalizes each ADCP transect and combines those normalized transects to compute a mean measurement profile. The program can fit a power law to the profile and in so doing provides a velocity index, the ratio between the depth-averaged and surface velocity. For the rivers in this study, the velocity index ranged from 0.82 – 0.92. Average radar and extrapolated ADCP surface velocities were in good agreement with average infrared PIV calculations.

  4. 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

  5. Yukon energy sector assessment 2003 : final report

    International Nuclear Information System (INIS)

    Kishchuk, P.

    2003-10-01

    A study was conducted to better understand energy issues in the Yukon. The study was based on the Yukon Energy Matrix which looks at the Yukon energy sector from the perspective of the capacity to supply various forms of energy, the markets for energy in the Yukon, and energy users. The sources of non-renewable energy in the Yukon range from natural gas, coal and oil. Renewable energy sources are also diverse and include water, biomass, wind, solar and geothermal. The main sources of electricity production in the Yukon are oil, water and wind. The link between energy and climate change has gained much attention in recent years, resulting in effective measures to conserve energy and increase energy efficiency. Coal, gas and oil are imported into the Yukon from markets in southern Alaska despite the fact that Yukon has its own vast quantities of these fossil-based forms of energy. As a result, the price of fossil-fuels consumed in the Yukon is determined in national and international markets. The absence of non-renewable energy production in the Yukon is also reflected in the lack of pipeline and rail infrastructure in the territory. The Yukon's electricity transmission grid is also very fragmented. For the purpose of this paper, energy use was categorized into the residential, commercial, industrial and transportation sectors. 19 refs., 8 tabs., 12 figs

  6. Regional, temporal, and species patterns of mercury in Alaskan seabird eggs: Mercury sources and cycling or food web effects?

    International Nuclear Information System (INIS)

    Day, Rusty D.; Roseneau, David G.; Vander Pol, Stacy S.; Hobson, Keith A.; Donard, Olivier F.X.; Pugh, Rebecca S.; Moors, Amanda J.; Becker, Paul R.

    2012-01-01

    Mercury concentration ([Hg]), δ 15 N, and δ 13 C values were measured in eggs from common murres (Uria aalge), thick-billed murres (U. lomvia), glaucous gulls (Larus hyperboreus), and glaucous-winged gulls (L. glaucescens) collected in Alaska from 1999 to 2005. [Hg] was normalized to a common trophic level using egg δ 15 N values and published Hg trophic magnification factors. Egg [Hg] was higher in murres from Gulf of Alaska, Cook Inlet, and Norton Sound regions compared to Bering Sea and Bering Strait regions, independent of trophic level. We believe the Yukon River outflow and terrestrial Hg sources on the southern Seward Peninsula are responsible for the elevated [Hg] in Norton Sound eggs. Normalizing for trophic level generally diminished or eliminated differences in [Hg] among taxa, but temporal variability was unrelated to trophic level. Normalizing murre egg [Hg] by trophic level improves the confidence in regional comparisons of Hg sources and biogeochemical cycling in Alaska. - Highlights: ► Seabird eggs used for monitoring Hg in Alaskan marine environment. ► Egg Hg concentrations normalized to common trophic level using δ 15 N. ► Geographic Hg patterns persist independent of trophic normalization. ► Trophic normalization reduces difference among taxa, but not temporal variability. ► Measuring δ 15 N and δ 13 C improve interpretation of seabird mercury monitoring data. - Normalizing mercury concentrations in seabird eggs to a common trophic level reveals that geographic patterns of mercury contamination exist in the Alaskan marine environment that are independent of food web effects.

  7. 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.

  8. Is proglacial field an important contributor to runoff in glacierized watershed? Lesson learned from a case study in Duke River watershed, Yukon, Canada.

    Science.gov (United States)

    Chesnokova, A.; Baraer, M.

    2017-12-01

    Sub-Arctic glacierized catchments are complex hydrological systems of paramount importance not only for water resources management but also for various ecosystem services. Those areas are environmentally fragile and host many climate-sensitive components of hydrological cycle. In a context of shifting from glacial to non-glacial regimes in Sub-Arctic, this study focuses on understanding hydrological role of proglacial field in runoff generation in headwaters of Duke River watershed, Canada, by comparing to that of alpine meadow (area that is not recently reworked by glacier). Duke Glacier, as many glaciers in St. Elias Mountains, is a surging glacier, and produced debris-charged dead-ice masses once the last surge has seized. In addition, such features as ice-cored moraines and taluses are found in proglacial field. Those features are hypothesised to cause high storage capacity and complex groundwater distribution systems which might affect significantly watershed hydrology. In order to estimate the contribution of different components of the alpine meadow and the proglacial field to runoff, HBCM, a multi-component distributed hydrochemical mixing model (Baraer et al., 2015) was applied. During field campaign in June 2016, 157 samples were taken from possible hydrological sources (end-members) and from main stream, and analysed for major ions, dissolved organic compounds and heavy stable water isotopes. End-members contribution was quantified based on tracer concentration at mixing points. Discharge was measured 6 km downstream from the glacier snout so that both proglacial field and alpine meadow occupy comparable areas of the catchment. Results show the difference between main water sources for the two hydrological systems: buried ice, ice-cored moraines and groundwater sources within proglacial field, and groundwater and supra-permafrost water within alpine meadow. Overall contribution of glaciers during June 2016 exceeded the contribution of the rest of the

  9. Yukon's common oil and gas regime

    International Nuclear Information System (INIS)

    Love, B.

    1998-01-01

    The Yukon's common oil and gas regime was developed in partnership with First Nations and it sets out the rules that will apply throughout the Yukon and on Yukon and First Nation lands. While separate and distinct, it conforms with and is compatible with other government systems and regimes. The major elements of the common regime include the Oil and Gas Act, regulations, policies, processes and agreements. The specific opportunities that are available in each phase of oil and gas development in the Yukon are described, with a map showing all basins, reserves and sites of current oil and gas activity. The Yukon has eight potential oil and gas basins: North Coast, Old Crow, Kandik, Eagle Plain, Peel Plateau, Bonnet Plume, Whitehorse Trough, and Liard Plateau. Only three of the eight, the Liard Plateau, Whitehorse Trough and Eagle Plain, have been explored. No wells have been drilled in several of Yukon's basins. Factors influencing economic opportunities in the Territory are also described, including: (1) international events and energy markets, (2) North American gas markets, (3) environmental factors, (4) competitiveness of the Yukon regime, and (5) the commitment of industry resources. 4 figs

  10. Investigating the ancient landscape and Cenozoic drainage development of southern Yukon (Canada), through restoration modeling of the Cordilleran-scale Tintina Fault.

    Science.gov (United States)

    Hayward, N.; Jackson, L. E.; Ryan, J. J.

    2017-12-01

    This study of southern Yukon (Canada) challenges the notion that the landscape in the long-lived, tectonically active, northern Canadian Cordillera is implicitly young. The impact of Cenozoic displacement along the continental- scale Tintina Fault on the development of the Yukon River and drainage basins of central Yukon is investigated through geophysical and hydrological modeling of digital terrain model data. Regional geological evidence suggests that the age of the planation of the Yukon plateaus is at least Late Cretaceous, rather than Neogene as previously concluded, and that there has been little penetrative deformation or net incision in the region since the late Mesozoic. The Tintina Fault has been interpreted as having experienced 430 km of dextral displacement, primarily during the Eocene. However, the alignment of river channels across the fault at specific displacements, coupled with recent seismic events and related fault activity, indicate that the fault may have moved in stages over a longer time span. Topographic restoration and hydrological models show that the drainage of the Yukon River northwestward into Alaska via the ancestral Kwikhpak River was only possible at restored displacements of up to 50-55 km on the Tintina Fault. We interpret the published drainage reversals convincingly attributed to the effects of Pliocene glaciation as an overprint on earlier Yukon River reversals or diversions attributed to tectonic displacements along the Tintina Fault. At restored fault displacements of between 230 and 430 km, our models illustrate that paleo Yukon River drainage conceivably may have flowed eastward into the Atlantic Ocean via an ancestral Liard River, which was a tributary of the paleo Bell River system. The revised drainage evolution if correct requires wide-reaching reconsideration of surficial geology deposits, the flow direction and channel geometries of the region's ancient rivers, and importantly, exploration strategies of placer gold

  11. Alaskan Commodities Irradiation Project

    International Nuclear Information System (INIS)

    Zarling, J.P.; Swanson, R.B.; Logan, R.R.

    1988-01-01

    The ninety-ninth US Congress commissioned a six-state food irradiation research and development program to evaluate the commercial potential of this technology. Hawaii, Washington, Iowa, Oklahoma and Florida as well as Alaska have participated in the national program; various food products including fishery products, red meats, tropical and citrus fruits and vegetables have been studied. The purpose of the Alaskan study was to review and evaluate those factors related to the technical and economic feasibility of an irradiator in Alaska. This options analysis study will serve as a basis for determining the state's further involvement in the development of food irradiation technology. 40 refs., 50 figs., 53 tabs

  12. Impact of Alaskan gas subsidy

    International Nuclear Information System (INIS)

    George, R.R.

    2002-01-01

    This report provides the Government of the Northwest Territories (GNWT) with an assessment of the impact of the Alaska natural gas tax credit proposed and passed in the United States Senate energy bill. In particular, Purvin and Gertz evaluated the impact of the Alaskan gas subsidy on potential Mackenzie Delta/Beaufort Sea production as well as existing and future production from other areas including Western Canada, the Rocky Mountains in the United States, and the Gulf Coast. The mechanisms through which other producing areas are affected were described and the typical volumetric impact is presented using gas models developed by Purvin and Gertz. The GNWT wants to maximize the benefits of Arctic gas development for its constituents but believes that its interests will be negatively impacted by subsidized Alaskan gas which will be applied for the period beginning in 2010. The tax credit sets a floor price of $3.25 (US)/MMBtu. Purvin and Gertz concludes that the Alaskan gas subsidy would produce a misallocation of resources and distort the continental North American natural gas market. It would encourage over investment in Alaskan gas production because the credit works as a false signal to the privileged few that divert resources from higher value activities to lower value activities. The winners of the Alaskan gas subsidy would be Alaskan producers and the Alaskan economy. The losers would be other resource owners, producers, and American taxpayers because they would finance the subsidy through a tax credit mechanism. There would be an overall loss to the economy because of sub-optimal allocation of resources. In addition, producers in existing producing areas such as the Mackenzie Delta/Beaufort Sea region would face lower market prices as a result of the subsidy, thereby reducing their investments. It was concluded that the Alaskan gas subsidy is counterproductive from the perspective of a secure continental supply of natural gas. 1 tab., 2 figs

  13. 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.

  14. The Alaskan mineral resource assessment program; background information to accompany folio of geologic and mineral resource maps of the Ambler River Quadrangle, Alaska

    Science.gov (United States)

    Mayfield, Charles F.; Tailleur, I.L.; Albert, N.R.; Ellersieck, Inyo; Grybeck, Donald; Hackett, S.W.

    1983-01-01

    The Ambler River quadrangle, consisting of 14,290 km2 (5,520 mi2) in northwest Alaska, was investigated by an interdisciplinary research team for the purpose of assessing the mineral resource potential of the quadrangle. This report provides background information for a folio of maps on the geology, reconnaissance geochemistry, aeromagnetics, Landsat imagery, and mineral resource evaluation of the quadrangle. A summary of the geologic history, radiometric dates, and fossil localities and a comprehensive bibliography are also included. The quadrangle contains jade reserves, now being mined, and potentially significant resources of copper, zinc, lead, and silver.

  15. Yukon Government climate change action plan

    International Nuclear Information System (INIS)

    2009-02-01

    This Climate Change Action Plan described the measures that are being taken by the Yukon Government to adapt to, understand, and reduce contributions to climate change. The action plan is the result of input received from more than 100 individuals and organizations and provides clear direction for a strategy that will minimize the negative impacts of climate change and provide economic, social and other environmental benefits through climate change mitigation. The Yukon government has already taken many actions that respond to climate change, such as: developing the Yukon Cold Climate Innovation Centre; supporting the Northern Climate Exchange for public education and outreach; funding community recycling depots and other groups that reduce waste generation, promote public awareness and divert solid waste; and working with provincial and territorial counterparts to enhance national building standards. The main objectives of the climate change actions are to enhance knowledge and understanding of climate change; adapt to climate change; reduce greenhouse gas emissions; and lead Yukon action in response to climate change. tabs., figs.

  16. Indians of Yukon and Northwest Territories.

    Science.gov (United States)

    Department of Indian Affairs and Northern Development, Ottawa (Ontario).

    A report is presented of the 7 American Indian tribes (Chipewyan, Yellowknife, Slave, Dogrib, Hare, Nahani, and Kutchin) of the Yukon and Northwest Territories. Described is each tribe's history, foodgathering methods, clothing, work distribution practices, social organization, and religion. A brief history of formal education among the tribes…

  17. Bird surveys at Stokes Point and Philips Bay, Yukon in 1983. No. 40

    Energy Technology Data Exchange (ETDEWEB)

    Dickson, D L; Dickson, H L; Aiudi, G M

    1988-01-01

    The distribution, abundance, and habitat preferences of birds were studied at Stokes Point, Phillips Bay and King Point in the northern Yukon in 1983. These data were gathered to assist in decisions about future development of a port to support marine drilling activities in the Beaufort Sea. Nesting bird densities at Stokes Point were similar to those found elsewhere on the Yukon Coastal Plain due to the similarity in habitat. The lagoon at Stokes Point was locally important to molting ducks. Several species occurred in higher densities at Phillips Bay than elsewhere on the Plain, mainly due to the deltas and spits created by rivers flowing into the Bay. These deltas were locally important to such species as molting non-breeding tundra swans, Canada geese, and ducks. During ground surveys in June, habitat was classified into 13 types and the nesting density for each bird species calculated for each habitat type. Overall bird densities were more than 3 times higher in lowland than in upland habitats. Passerine densities and species were highest in the tall shrub type of habitat found primarily in stream and river valleys. The Yukon Coastal Plain is an important nesting area for the stilt sandpiper, which has a limited breeding range. The Plain is also nationally important for nesting long-billed dowitchers and yellow wagtails, both fairly common in the study area but with very limited breeding distribution within Canada. The Plain is also internationally important to fall staging snow geese. 38 refs., 17 figs., 35 tabs.

  18. 75 FR 29582 - Yukon Flats National Wildlife Refuge, Fairbanks, AK

    Science.gov (United States)

    2010-05-26

    ... from climate change. Fourth, infrastructure associated with access corridors from the proposed exchange... statement (EIS) for a Proposed Land Exchange in the Yukon Flats National Wildlife Refuge (NWR, Refuge). We... this notice, we finalize the EIS process for a Proposed Land Exchange in the Yukon Flats NWR. In...

  19. Origin of last-glacial loess in the western Yukon-Tanana Upland, central Alaska, USA

    Science.gov (United States)

    Muhs, Daniel; Pigati, Jeffrey S.; Budahn, James R.; Skipp, Gary L.; Bettis, E. Arthur; Jensen, Britta

    2018-01-01

    Loess is widespread over Alaska, and its accumulation has traditionally been associated with glacial periods. Surprisingly, loess deposits securely dated to the last glacial period are rare in Alaska, and paleowind reconstructions for this time period are limited to inferences from dune orientations. We report a rare occurrence of loess deposits dating to the last glacial period, ~19 ka to ~12 ka, in the Yukon-Tanana Upland. Loess in this area is very coarse grained (abundant coarse silt), with decreases in particle size moving south of the Yukon River, implying that the drainage basin of this river was the main source. Geochemical data show, however, that the Tanana River valley to the south is also a likely distal source. The occurrence of last-glacial loess with sources to both the south and north is explained by both regional, synoptic-scale winds from the northeast and opposing katabatic winds that could have developed from expanded glaciers in both the Brooks Range to the north and the Alaska Range to the south. Based on a comparison with recent climate modeling for the last glacial period, seasonality of dust transport may also have played a role in bringing about contributions from both northern and southern sources.

  20. Assessing bear-human conflicts in the Yukon Territory

    OpenAIRE

    Lukie, Raechel Dawn

    2010-01-01

    Managing conflicts between bears and humans is vital for human safety and for the conservation of bears. This study investigated black bear (Ursus americanus) and grizzly bear (Ursus arctos) interactions with humans in 18 major communities of the Yukon Territory. I used an information theoretic approach to generate predictive models of the relative potential of bear-human interaction for the 9 conservation officer management regions in the Yukon Territory. I independently modeled interactions...

  1. Teaching in the Yukon: Exploring Teachers' Efficacy Beliefs, Stress, and Job Satisfaction in a Remote Setting

    Science.gov (United States)

    Klassen, Robert M.; Foster, Rosemary Y.; Rajani, Sukaina; Bowman, Carley

    2009-01-01

    This article presents a mixed methods examination of teachers' job beliefs in the Yukon Territory in northern Canada. In Study 1 we used questionnaires to examine job beliefs for 221 teachers from the Yukon and western Canada. Teachers' self- and collective efficacy and workload stress were lower for Yukon teachers, but levels of overall stress…

  2. Nesting ecology of tundra swans on the coastal Yukon-Kuskokwim Delta, Alaska

    Science.gov (United States)

    Babcock, C.A.; Fowler, A.C.; Ely, Craig R.

    2002-01-01

    Nesting ecology of Tundra Swans (Cygnus columbianus columbianus) was studies the Kashunuk River near Old Chevak (61A?26a??N, 165A?27a??W), on the Yukon-Kuskokwim Delta of western Alaska from 1988-2000. Annual variation in snow-melt chronology, nesting phenology, nesting density, clutch size and nest success was examined. The same area (approximately 23 kmA?) was searched each year and nests were found as early as possible in the laying period. Laying initiation dates ranged from 1-27 May and hatch dates from 12 June a?? 4 July among pairs and years of study. The peak arrival of Tundra Swans and the phenology of nest initiation and hatch were highly correlated with the progression of ice and snow melt in spring. Nest density averaged 0.71 kmA? and 89% of nesting pairs hatched at least one egg. Incubation period ranged from 26 to 33 days with a median of 30 days. Clutch size varied significantly among years, driven by a low mean value of 3.4 eggs in 1999. Clutch sizes were generally larger than found in previous investigations on the Yukon-Kuskokwim Delta, and nearly one egg larger than reported for clutches from Alaskaa??s North Slope (=70A?N). There was no indication of reduced clutch size in years of late spring snow melt, although nesting density tended to be lower.

  3. The Yukon settlement settled little enough

    Energy Technology Data Exchange (ETDEWEB)

    Sillars, L.

    1997-01-27

    Northern Cross, a small Alberta oil company has discovered the first promising petroleum prospect in the Yukon Territories in three decades. However, the company is unable to proceed with construction and production because the aboriginal community of Old Crow alleged that the project endangers the famous Porcupine Caribou Herd, has international implications, and infringes on traditional Gwitchin Indian territory. The wells in question were originally drilled in the 1960s, but abandoned due to lack of infrastructure, and ongoing negotiations with native groups. In 1993 the federal government indicated that land claim issues were settled. Northern Cross was the first company in to resume work on the wells, since the Dempster Highway, built in the meantime, makes getting the oil out a much more feasible proposition. The delay in approving Northern Cross`s application revolves around the dispute about the location of the wells,i.e. are they situated on tribal land or on Crown Land. The Department of Indian and Northern Affairs is investigating the rival claims, and promises to have a ruling within 12 months.

  4. AirSWOT Measurements of Water Surface Elevations and Hydraulic Gradients over the Yukon Flats, Alaska

    Science.gov (United States)

    Pitcher, L. H.; Pavelsky, T.; Smith, L. C.; Moller, D.; Altenau, E. H.; Lion, C.; Bertram, M.; Cooley, S. W.

    2017-12-01

    AirSWOT is an airborne, Ka-band synthetic aperture radar interferometer (InSAR) intended to quantify surface water fluxes by mapping water surface elevations (WSE). AirSWOT will also serve as a calibration/validation tool for the Surface Water and Ocean Topography (SWOT) satellite mission (scheduled for launch in 2021). The hydrology objectives for AirSWOT and SWOT are to measure WSE with accuracies sufficient to estimate hydrologic fluxes in lakes, wetlands and rivers. However, current understanding of the performance of these related though not identical instruments when applied to complex river-lake-wetland fluvial environments remains predominantly theoretical. We present AirSWOT data acquired 15-June-2015 over the Yukon Flats, Alaska, USA, together with in situ field surveys, to assess the accuracy of AirSWOT WSE measurements in lakes and rivers. We use these data to demonstrate that AirSWOT can be used to estimate large-scale hydraulic gradients across wetland complexes. Finally, we present key lessons learned from this AirSWOT analysis for consideration in future campaigns, including: maximizing swath overlap for spatial averaging to minimize uncertainty as well as orienting flight paths parallel to river flow directions to reduce along track aircraft drift for neighboring flight paths. We conclude that spatially dense AirSWOT measurements of river and lake WSEs can improve geospatial understanding of surface water hydrology and fluvial processes.

  5. Green current in gold land. The Canadian territory Yukon focuses on renewable energy sources; Gruener Strom im Goldland. Das kanadische Territorium Yukon setzt auf erneuerbare Energien

    Energy Technology Data Exchange (ETDEWEB)

    Baumann, Berthold

    2010-07-01

    The report covers information on the hydropower plant Whitehorse in the Canadian Yukon territory with the dammed Schwatka Lake. Electricity for the gold town Dawson City is supplied by the hydro power plant Mayo at the Wareham Lake. A second project Mayo B is in construction. Small villages are usually supported by diesel generators. Recently some experiments are performed using wind power, specific Yukon modification of wind power stations were developed. The Yukon Energy Corporation together with Yukon Green Power has also started photovoltaic electricity generation.

  6. Rapid changes in the level of Kluane Lake in Yukon Territory over the last millennium

    Science.gov (United States)

    Clague, John J.; Luckman, Brian H.; Van Dorp, Richard D.; Gilbert, Robert; Froese, Duane; Jensen, Britta J. L.; Reyes, Alberto V.

    2006-09-01

    The level of Kluane Lake, the largest lake in Yukon Territory, was lower than at present during most of the Holocene. The lake rose rapidly in the late seventeenth century to a level 12 m above present, drowning forest and stranding driftwood on a conspicuous high-stand beach, remnants of which are preserved at the south end of the lake. Kluane Lake fell back to near its present level by the end of the eighteenth century and has fluctuated within a range of about 3 m over the last 50 yr. The primary control on historic fluctuations in lake level is the discharge of Slims River, the largest source of water to the lake. We use tree ring and radiocarbon ages, stratigraphy and sub-bottom acoustic data to evaluate two explanations for the dramatic changes in the level of Kluane Lake. Our data support the hypothesis of Hugh Bostock, who suggested in 1969 that the maximum Little Ice Age advance of Kaskawulsh Glacier deposited large amounts of sediment in the Slims River valley and established the present course of Slims River into Kluane Lake. Bostock argued that these events caused the lake to rise and eventually overflow to the north. The overflowing waters incised the Duke River fan at the north end of Kluane Lake and lowered the lake to its present level. This study highlights the potentially dramatic impacts of climate change on regional hydrology during the Little Ice Age in glacierised mountains.

  7. 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

  8. Pre-"peak water" time in the southwest Yukon: when cryospheric changes trigger hydrological regime shifts

    Science.gov (United States)

    Baraer, M.; Chesnokova, A.; Huh, K. I.; Laperriere-Robillard, T.

    2017-12-01

    Saint-Elias Mountains host numerous cryospheric systems such as glaciers, seasonal and perennial snow cover, permafrost, aufeis, and different forms of buried ice. Those systems are very sensitive to climate changes and exhibit ongoing reduction in extent and/or changes in formation/ablation times. Because they highly influence the hydrological regimes of rivers, cryospheric changes raise concerns about consequences for regional water resources and ecosystems. The present study combines historical data analysis and hydrological modeling in order to estimate how cryospheric changes impact hydrological regimes at eight watersheds of different glacier cover (0- 30%) in the southwest Yukon. Methods combine traditional hydrograph analysis techniques and more advance techniques such as Fast Fourier Transform filters used to isolate significant trends in discharge properties from noise or climatic oscillations. Measured trends in discharge variables are connected to cryospheric changes by using a water balance / peak water model (Baraer et al., 2012), here adapted to the main cryospheric systems that characterize the southwest Yukon.Results show three distinct hydrological regimes for (1) non glacierized, (2) glacierized, and (3) major lakes hosting catchments. The studied glacierized catchments have not passed the "peak water" yet and still exhibit increases in yearly and late summer discharges and a decrease in runoff variability. All watersheds show an increase in winter discharge and a snowmelt-driven shift of yearly peak discharge toward earlier in the season. The study suggests that, in a couple of decades, water resources and dependent ecosystems will face the combined effects of (A) a shift in the contribution trend from declining perennial cryospheric systems and (B) continuing alteration of the contribution from the seasonal cryospheric systems.

  9. Engaging Alaskan Students in Cryospheric Research

    Science.gov (United States)

    Yoshikawa, K.; Sparrow, E. B.; Kopplin, M.

    2011-12-01

    The Permafrost/Active Layer Monitoring Program is an ongoing project, which builds on work begun in 2005 to establish long-term permafrost and active layer monitoring sites adjacent to schools in Alaskan communities and in the circumpolar permafrost region. Currently, there are about 200 schools in Alaska involved in the project including also Denali National Park and Preserve. The project has both scientific and outreach components. The monitoring sites collect temperature data on permafrost, and the length and depth of the active layer (the layer above the permafrost that thaws during summer and freezes again during winter). To ensure scientific integrity, the scientist installed all of the monitoring instruments and selected the sites representative of the surrounding biome and thermal conditions. This is a unique collaboration opportunity in that 1) uses scientifically accurate instruments, 2) is scientist led and supervised including instrumentation set-up and data quality check, 3)has teacher/student organized observation network, 4) increased spatial scale of monitoring sites that covers all of the Alaskan communities. Most of the monitoring sites are located in remote communities, where the majority of residents depend on a subsistence lifestyle. Changes in climate, length of seasons, and permafrost conditions directly impact natural resources and subsistence activities. Changes in permafrost conditions also affect local ecosystems and hydrological regimes, and can influence the severity of natural disasters. In addition to extending our knowledge of the arctic environment, the program involves school-age students. Several students have been using the data for their projects and have been inspired to continue their studies. The data gathered from these stations are shared with other schools and made available to the public through our web site (http://www.uaf.edu/permafrost). Also communities have increasingly become interested in this project not only as

  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. Doing business in the North (the Yukon chapter) : what are the realities one must accept?

    International Nuclear Information System (INIS)

    Austring, L.N.

    2000-01-01

    A summary of the northern style of doing business was presented with emphasis on the changing face of the North, the Yukon-British Columbia connection and the strong presence of government and the legal profession in the Yukon Territory. Until about 25 years ago, the Yukon was administered as a section of the Department of Indian Development and Northern Affairs. Since then, the federal government has been devolving its power to the Yukon government regarding oil and gas resources and this will likely happen in the near future with mineral resources. In 1993, the 14 First Nations of the Yukon signed the Umbrella Final Agreement (UFA) with the government of Canada and the Yukon dealing with land claims issues, in particular specific land selection, transfer of resources, payment of money and self-government powers. This paper also described licensing and registration requirements for anyone doing business in the Yukon. The paper provided a brief review plus the name of a person to contact, an address, web site and telephone number for the Business Corporations Act, Partnership and Business Names Act, Municipal Act, Workers Compensation Health and Safety Act, Motor Transport Act, Motor Vehicles Act and Fuel Oil Tax Act. The paper also reviewed other matters such as the Personal Property Security Act, the Workers Compensation and Occupational Health and Safety Board, the Canada Labour Code, Employment Standards Act, insurance matters, transportation matters and taxation

  12. Exchanging ideas on climate change in the Yukon

    International Nuclear Information System (INIS)

    2000-01-01

    Climate change models predict that Canada's North will receive the earliest and most extreme impacts of a changing climate. An increase in temperature could affect the Yukon economy, wildlife, traditional cultures and recreational activities. For this reason, the Northern Climate Exchange visited communities in the Yukon to exchange ideas with residents regarding observations and concerns about changes in weather and the land. The information obtained from the visits provides a better understanding of the situation and could help determine priorities for further research. The report showed that the residents are concerned about their observations, but public opinion on what do do about climate change varies among communities. While there are large amounts of local information on the subject, very little of it is documented. Very little research is available at a scale that is useful to community-level decision-making processes. This makes local observations even more valuable as they are in the best position to understand and assess their vulnerability to climate change. It was recommended that local and traditional knowledge on climate change be properly documented and that a community-based environmental monitoring strategy be developed. The final recommendation was to develop policy and decision-support tools. 3 tabs., 10 figs

  13. Mountain Permafrost in the Yukon Territory, Canada: Mapping and Modelling

    Science.gov (United States)

    Lewkowicz, A. G.; Bonnaventure, P.; Schultz, E.; Etzelmuller, B.

    2006-12-01

    The distribution and characteristics of mountain permafrost in North America are poorly known compared to lowland permafrost, and predictions of climatic change impacts are therefore subject to a higher degree of uncertainty. Recent DC resistivity soundings in association with borehole temperature information in the Yukon Territory, show the wide range of permafrost conditions that can exist at sites separated by short distances. To provide baseline information for future modelling, efforts are underway to produce a detailed map of permafrost probability in the mountains of the southern half of the Yukon Territory (60-65°N), an area greater than 200 x 103km2. The methodology is based on the Basal Temperature of Snow (BTS) technique, first developed in the European Alps. Ground surface temperatures measured at the base of snow > 80 cm thick in late winter are an indicator of permafrost presence or absence. We have used this method successfully in three study areas of about 200 km2: first, Wolf Creek basin near Whitehorse (Lewkowicz and Ednie, 2004) and now the western side of the Ruby Range adjacent to Kluane Lake, and the Haines Summit area in northwestern British Columbia. In each area, (1) we installed miniature temperature loggers at the ground surface and in the air to check on the timing of the BTS measurements; (2) we measured BTS values in the elevation zone across which permafrost was expected to become widespread; (3) we modelled the BTS spatial field using elevation (from a 30 m DEM) and potential incoming solar radiation (PISR) as the independent variables; and (4) we used logistic regression to compare the modelled BTS values with pit observations made in late-summer of the presence or absence of frozen ground. Both elevation and PISR were significant in the Wolf Creek and Ruby Range sites which have relatively continental climates and fall within the Upper Yukon-Stikine Basin climatic region (Wahl et al., 1987). For the Haines Summit area, however

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

    Directory of Open Access Journals (Sweden)

    Shawn R. Francis

    2011-12-01

    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.

  15. 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.

  16. Microphysical Properties of Alaskan Volcanic Ash

    Science.gov (United States)

    Puthukkudy, A.; Espinosa, R.; Rocha Lima, A.; Remer, L.; Colarco, P. R.; Whelley, P.; Krotkov, N. A.; Young, K.; Dubovik, O.; Wallace, K.; Martins, J. V.

    2017-12-01

    Volcanic ash has the potential to cause a variety of severe problems for human health and the environment. Therefore, effective monitoring of the dispersion and fallout from volcanic ash clouds and characterization of the aerosol particle properties are essential. One way to acquire information from volcanic clouds is through satellite remote sensing: such images have greater coverage than ground-based observations and can present a "big picture" perspective. A challenge of remote sensing is that assumptions of certain properties of the target are often a pre-requisite for making accurate and quantitative retrievals. For example, detailed information about size distribution, sphericity, and optical properties of the constituent matter is needed or must be assumed. The same kind of information is also needed for atmospheric transport models to properly simulate the dispersion and fallout of volcanic ash. Presented here is a laboratory method to determine the microphysical and optical properties of volcanic ash samples collected from two Alaskan volcanoes with markedly different compositions. Our method uses a Polarized Imaging Nephelometer (PI-Neph) and a system that re-suspends the particles in an air flow. The PI-Neph measures angular light scattering and polarization of the re-suspended particles from 3o to 175o in scattering angle, with an angular resolution of 1o . Primary measurements include phase function and polarized phase function at three wavelengths (445nm, 532nm, and 661nm). Size distribution, sphericity, and complex refractive index are retrieved indirectly from the PI-Neph measurements using the GRASP (Generalized Retrieval of Aerosol and Surface Properties) inversion algorithm. We report the results of this method applied to samples from the Mt. Okmok (2008) and Mt. Katmai (1912) volcanic eruptions. To our knowledge, this is the first time direct measurements of phase matrix elements of ash from Mt. Okmok and Mt. Katmai have been reported. Retrieved

  17. Alaska Is Our Home--Book 3: A Natural Science Handbook for Alaskan Students.

    Science.gov (United States)

    Bury, John; Bury, Susan

    The third book in a series of natural science handbooks for Alaskan students focuses on Alaskan plantlife. The first chapter, on trees, gives general information about trees and explains how to identify and locate trees in the three main Alaskan tree families: pine, willow, and birch. The second chapter, on plants, describes 14 kinds of edible…

  18. 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

    2016-01-01

    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.

  19. 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

  20. Radon in homes: The Alaskan experience

    International Nuclear Information System (INIS)

    Seifert, R.D.

    1990-01-01

    For the past four years, since radon was first found to be a concern in Alaska in 1986, the interest and awareness of radon as a special housing and health concern has continued to grow. This paper will discuss the features of a house in Alaska which would characterize it as at risk for radon, and also those efforts at mitigation which have been most effective in reducing radon under Alaskan conditions. Clearly radon must be able to enter a home in order to be a problem. Riefenstuhl and Kline (personal communication, 1988) have analyzed the conditions for radon transport from soils to home interiors very lucidly through the following scheme: four factors must exist in a house locale for it to be a radon at risk house. Two of the factors are geological in nature: (1) there must be adequate uranium and therefore ample radon to provide a source for transport; (2) there must be enough permeability in the soil to allow rapid soil gas movement to carry radon from its origin to the interior of the home within two half-lives of time (six days) or so. The other two factors are determined by the structure of the house itself and the way in which it is operated: (3) the house must have soil contact and imperfections, holes, cracks, intentional perforations which allow movement of soil gas with radon through the envelope of the basement or crawlspace; (4) there must be a lower pressure inside the house than in the soil so that soil gas flows into the house. All four of these characteristics are required to have radon be a problem. The absence of any single characteristic will eliminate radon (in general). This presents a series of options for mitigation of radon then, since elimination of any of the four characteristics will mitigate radon

  1. Impacts on the Yukon and the Mackenzie Valley

    International Nuclear Information System (INIS)

    Parker, N.; Cowan, C.

    1993-01-01

    Climate models predicting the effects of global warming due to the greenhouse effect give rough estimates of the sign and size of expected changes in temperature and precipitation. However, these models do not show what to expect from a warmer regional climate. One approach to resolve this issue is to use climate information from past years and find a year whose climate is close to what the models say will exist in the future. This approach is used to gain some understanding into what climatic warming may mean to the Yukon and Mackenzie Valley areas of Arctic Canada. The summer of 1989, one of the warmest summers on record, is studied to examine the effects of climate warming on agriculture, stream flow, glacial melting, permafrost degradation, and forest fires. Under a climate scenario in which the 1989 summer became the average, agricultural land classification would increase although moisture and soil suitability would still limit many crops. Lower-level glaciers would likely continue their rapid melt while some higher-level glaciers and snowfields might expand due to increased moisture, especially during winter. 10 refs., 5 figs., 4 tabs

  2. Decadal water quality variations at three typical basins of Mekong, Murray and Yukon

    Science.gov (United States)

    Khan, Afed U.; Jiang, Jiping; Wang, Peng

    2018-02-01

    Decadal distribution of water quality parameters is essential for surface water management. Decadal distribution analysis was conducted to assess decadal variations in water quality parameters at three typical watersheds of Murray, Mekong and Yukon. Right distribution shifts were observed for phosphorous and nitrogen parameters at the Mekong watershed monitoring sites while left shifts were noted at the Murray and Yukon monitoring sites. Nutrients pollution increases with time at the Mekong watershed while decreases at the Murray and Yukon watershed monitoring stations. The results implied that watershed located in densely populated developing area has higher risk of water quality deterioration in comparison to thinly populated developed area. The present study suggests best management practices at watershed scale to modulate water pollution.

  3. 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.

  4. Hydrology of two slopes in subarctic Yukon, Canada

    Science.gov (United States)

    Carey, Sean K.; Woo, Ming-Ko

    1999-11-01

    Two subarctic forested slopes in central Wolf Creek basin, Yukon, were studied in 1996-1997 to determine the seasonal pattern of the hydrologic processes. A south-facing slope has a dense aspen forest on silty soils with seasonal frost only and a north-facing slope has open stands of black spruce and an organic layer on top of clay sediments with permafrost. Snowmelt is advanced by approximately one month on the south-facing slope due to greater radiation receipt. Meltwater infiltrates its seasonally frozen soil with low ice content, recharging the soil moisture reservoir but yielding no lateral surface or subsurface flow. Summer evaporation depletes this recharged moisture and any additional rainfall input, at the expense of surface or subsurface flow. The north-facing slope with an ice rich substrate hinders deep percolation. Snow meltwater is impounded within the organic layer to produce surface runoff in rills and gullies, and subsurface flow along pipes and within the matrix of the organic soil. During the summer, most subsurface flows are confined to the organic layer which has hydraulic conductivities orders of magnitudes larger than the underlying boulder-clay. Evaporation on the north-facing slope declines as both the frost table and the water table descend in the summer. A water balance of the two slopes demonstrates that vertical processes of infiltration and evaporation dominate moisture exchanges on the south-facing slope, whereas the retardation of deep drainage by frost and by clayey soil on the permafrost slope promotes a strong lateral flow component, principally within the organic layer. These results have the important implication that permafrost slopes and organic horizons are the principal controls on streamflow generation in subarctic catchments.

  5. 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.

    2016-01-01

    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.

  6. Revegetation of Alaskan coal mine spoils. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, W W; Mitchell, G A; McKendrick, J D

    1980-05-23

    Activities initiated after the start of the revegetation project on Alaskan coal mine spoils on September 1, 1979 have consisted mainly of some fall plantings (dormant seedings) and soil and coal spoil samplings and analyses. Because of the late summer start for the project, only a limited amount of field work could be initiated in plant material studies. This consisted of a fall planting at the Usibelli mine site at Healy in interior Alaska. The planting was intended to test the efficacy of seeding in the frost period following the growing season, requiring the seed to remain dormant over winter and to germinate when conditions become favorable in late spring. It also was intended as a comparison of a number of different grasses. Thirty entries were seeded in three replications. Fifteen species of grasses and a clover were included in the trial. The site provided for the trial was on overburden material along a streambed. Among the entries were eight cultivars of introduced grasses, five cultivars of native Alaskan germplasm, one introduced clover cultivar, and sixteen experimental grasses mainly of Alaskan origin.

  7. Ecological investigation of Alaskan resource development

    International Nuclear Information System (INIS)

    Hanson, W.C.; Eberhardt, L.E.

    1981-01-01

    The objective of this research is to provide an integrated program for the definition of ecological consequences of resource developments in northern Alaska. Information is presented on affected populations of arctic foxes, small mammals, and tundra-nesting birds in the Prudhoe Bay oil field and along the Trans-Alaska Pipeline and haul road; findings from similar studies from the Colville River Delta and other affected habitats; field experiments to determine the sensitivity of lichen communities of the Brooks Range to sulfur dioxide concentrations likely to be encountered near pipeline pumping stations; and amounts of radionuclides from worldwide fallout in the lichen-caribou-Eskimo food chain

  8. The climate adaptation programs and activities of the Yellowstone to Yukon Conservation Initiative

    Science.gov (United States)

    Wendy L. Francis

    2011-01-01

    The Yellowstone to Yukon Conservation Initiative (Y2Y) is an innovative transboundary effort to protect biodiversity and facilitate climate adaptation by linking large protected core areas through compatible land uses on matrix lands. The Y2Y organization acts as the keeper of the Y2Y vision and implements two interconnected programs - Science and Action, and Vision...

  9. Fire history and fire management implications in the Yukon Flats National Wildlife Refuge, interior Alaska

    Science.gov (United States)

    S. A. Drury; P. J. Grissom

    2008-01-01

    We conducted this investigation in response to criticisms that the current Alaska Interagency Fire Management Plans are allowing too much of the landscape in interior Alaska to burn annually. To address this issue, we analyzed fire history patterns within the Yukon Flats National Wildlife Refuge, interior Alaska. We dated 40 fires on 27 landscape points within the...

  10. Yukon Energy Corporation annual report for the year ended December 31, 1992

    International Nuclear Information System (INIS)

    1992-01-01

    The Yukon Energy Corporation (YEC) is a subsidiary of a Crown corporation of the territorial government. It generates and distributes 89% of Yukon Territory's electric power. Installed generating capacity in 1992 was 75 MW from hydroelectric plants and 44 MW from diesel generators, for a total of 119 MW. Earnings rose 20% in 1992, from $5.9 million in 1991 to $7.1 million in 1992. The rate of return on equity was 14.8%, up from 12.4% in 1991. This increase in return on equity is due in part to a reduction in the Corporation's equity at December 31, 1992 as part of a restructuring of its capital. The Corporation invested $11.6 million in system improvements during the year. This was a continuation of a program to upgrade YEC facilities. Over $27 million has been spent over the last three years. These improvements were necessary to modernize the system and to improve power quality and reliability. The Corporation completed its 1992 Resource Plan and a hearing was held with the Yukon Utilities Board in October. The plan provided a comprehensive outline of all capital planning activities, including reconnaissance, supply-side development, and demand-side management. The major environmental concern for the Corporation continued to be the management regime at the Aishihik Lake reservoir. A second year of field studies on whitefish recruitment was undertaken by the Yukon Government's Department of Renewable Resources. Financial statements are included. 7 figs

  11. 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.

  12. Fire increases carbon fluxes from inland waters of the Yukon-Kuskokwim delta, Alaska.

    Science.gov (United States)

    Mann, P. J.; Bristol, E. M.; Dabrowski, J. S.; Jimmie, J. A.; Melton, S.; Navarro-Perez, E.; Peter, D. L.; Sae-lim, N.; Holmes, R. M.; Natali, S.; Schade, J. D.

    2017-12-01

    Climate change across high-latitude regions is expected to alter the hydrology and biogeochemistry of arctic environments, significantly impacting ecosystem C cycling and landscape scale C budgets. Fire represents one manifestation of arctic climate change with the number, extent and intensity of fires projected to increase over upcoming decades. The Yukon-Kuskokwim River Delta (YKD), Alaska, experienced unprecedented tundra fires in 2015 when more than 250 km2 underwent burn. In this study, we examined the effects of the 2015 YKD fire upon aquatic and terrestrial C fluxes, and investigated potential mechanisms causing changes to C-cycling. Field work was conducted during summer months (July-Sept) over two years, complimented with aerobic and anaerobic laboratory incubations. Burning of the terrestrial organic layer caused dramatic changes to soil moisture, the proportion of organic versus mineral soils near the land surface, and average active layer depth. Fire caused increased C fluxes (particularly CH4) from re-wet soils relative to unburnt soils, suggesting an interaction exists between fire history and soil moisture. Higher C fluxes from saturated ponds and fens across the landscape provided additional support for this theory. Pore-water chemistry in burnt catchments contained higher inorganic nutrient concentrations, specifically nitrogen, potentially driven by changing soil sorption processes and/ or infiltration rates. Organic matter delivery to inland waters within burns contained DOC of lower apparent molecular weight and aromaticity relative to unburnt waters (inferred from optical measures), and waters typically had higher temperatures, pH and dissolved mineral content. Lake and low-lying pond CO2 and CH4 emissions were consistently higher in burn catchment regions, with three to four-fold higher C emission rates. Our study indicates that fire may promote aquatic and terrestrial pathways for C loss and that these enhanced emissions may persist for years

  13. Ecological investigation of Alaskan resource development

    International Nuclear Information System (INIS)

    Hanson, W.C.; Eberhardt, L.E.

    1980-01-01

    The objective is to provide an integrated program for the definition of ecological consequences of resource developments in northern Alaska. The qualitative and quantitative results obtained describe the environmental costs incurred by petroleum resource extraction and transportation, including interaction of wildlife populations with industrial activities. This section of the Annual Report presents information on impacted populations of arctic foxes, small mammals, and tundra-nesting birds in the Prudhoe Bay oil field and along the Trans-Alaska Pipeline and haul road; findings from similar studies from the Colville River Delta and other unimpacted habitats; field experiments to determine the sensitivity of lichen communities of the Brooks Range to sulfur dioxide concentrations likely to be encountered near pipeline pumping stations; and amounts of worldwide-fallout radionuclides in the lichen-caribou-Eskimo food chain

  14. Alaskan Native High School Dropouts: A Report Prepared for Project ANNA.

    Science.gov (United States)

    Jacobson, Desa

    Presented is a summary of the Alaskan Native high school dropouts. The data collected on 180 Native Alaskan high school dropouts was taken from the regional dormitories at Nome, Kodiak, Bethel and Boarding Home programs in Anchorage, Tok, Fairbanks, Dillingham, and Ketchikan. Students who terminated for academic reasons, failed to attend school,…

  15. Circulation and water properties in the landfast ice zone of the Alaskan Beaufort Sea

    Science.gov (United States)

    Weingartner, Thomas J.; Danielson, Seth L.; Potter, Rachel A.; Trefry, John H.; Mahoney, Andy; Savoie, Mark; Irvine, Cayman; Sousa, Leandra

    2017-09-01

    Moorings, hydrography, satellite-tracked drifters, and high-frequency radar data describe the annual cycle in circulation and water properties in the landfast ice zone (LIZ) of the Alaskan Beaufort Sea. Three seasons, whose duration and characteristics are controlled by landfast ice formation and ablation, define the LIZ: ;winter;, ;break-up;, and ;open-water;. Winter begins in October with ice formation and ends in June when rivers commence discharging. Winter LIZ ice velocities are zero, under-ice currents are weak ( 5 cm s-1), and poorly correlated with winds and local sea level. The along-shore momentum balance is between along-shore pressure gradients and bottom and ice-ocean friction. Currents at the landfast ice-edge are swift ( 35 cm s-1), wind-driven, with large horizontal shears, and potentially unstable. Weak cross-shore velocities ( 1 cm s-1) imply limited exchanges between the LIZ and the outer shelf in winter. The month-long break-up season (June) begins with the spring freshet and concludes when landfast ice detaches from the bottom. Cross-shore currents increase, and the LIZ hosts shallow ( 2 m), strongly-stratified, buoyant and sediment-laden, under-ice river plumes that overlie a sharp, 1 m thick, pycnocline across which salinity increases by 30. The plume salt balance is between entrainment and cross-shore advection. Break-up is followed by the 3-month long open-water season when currents are swift (≥20 cm s-1) and predominantly wind-driven. Winter water properties are initialized by fall advection and evolve slowly due to salt rejection from ice. Fall waters and ice within the LIZ derive from local rivers, the Mackenzie and/or Chukchi shelves, and the Arctic basin.

  16. [Alaskan commodities irradiation project: An options analysis study

    International Nuclear Information System (INIS)

    Zarling, J.P.; Swanson, R.B.; Logan, R.R.

    1989-09-01

    The ninety-ninth US Congress commissioned a six-state food irradiation research and development program to evaluate the commercial potential of this technology. Hawaii, Washington, Iowa, Oklahoma and Florida as well as Alaska have participated in the national program; various food products including fishery products, red meats, tropical and citrus fruits and vegetables have been studied. The purpose of the Alaskan study was to review and evaluate those factors related to the technical and economic feasibility of an irradiator in Alaska. This options analysis study will serve as a basis for determining the state's further involvement in the development of food irradiation technology

  17. 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.

  18. Leucocytozoon simondi in Emperor Geese from the Yukon-Kuskokwim Delta in Alaska

    Science.gov (United States)

    Hollmen, T.K.; Franson, J.C.; Creekmore, L.H.; Schmutz, J.A.; Fowler, A.C.

    1998-01-01

    We surveyed Emperor Geese (Chen canagica) in western Alaska for avian hematozoa. Blood smears were collected from 134 adults and goslings in late July 1996, on their breeding grounds on the Yukon-Kuskokwim Delta. One of 134 (0.7%) Emperor Geese harbored Leucocytozoon simondi, representing a new host record for this parasite. No other hematozoa were detected. This is one of few reports of avian blood parasites from the arctic tundra.

  19. 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.

  20. Phlorotannins from Alaskan Seaweed Inhibit Carbolytic Enzyme Activity

    Science.gov (United States)

    Kellogg, Joshua; Grace, Mary H.; Lila, Mary Ann

    2014-01-01

    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. PMID:25341030

  1. Modeling and dynamic monitoring of ecosystem performance in the Yukon River Basin

    Science.gov (United States)

    Wylie, Bruce K.; Zhang, L.; Ji, Lei; Tieszen, Larry 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.

  2. 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...

  3. The effects of fire on greenhouse gas fluxes from mosses and lichen patches in the Yukon Kuskokwim Delta, AK.

    Science.gov (United States)

    Navarro-Perez, E.; Natali, S.; Schade, J. D.; Holmes, R. M.; Mann, P. J.

    2017-12-01

    Climate change has altered patterns of temperature, emissions of greenhouse gases and increased fire frequencies, especially in the Artic. Until recently, the Arctic has been a carbon (C) sink, but have begun releasing C in recent years, likely in response to warming temperatures, permafrost thaw and resulting changes in microbial processes. In addition, increases in fire frequency and intensity are changing vegetation patterns, particularly the relative importance of mosses and lichens. These changes alter soil temperatures, nutrient availability, and moisture, consequently affecting microbial processes and the release of greenhouse gases (GHG) such as N2O, CO2 and CH4. The objective of this research was to understand how recent fires in the Yukon-Kuskokwim River Delta in southwest Alaska are affecting the emission of GHGs from peat plateau soils. We hypothesized that the presence of mosses and lichen would change soil moisture and temperature, leading to changes in GHG production after fire. We also hypothesized that fire would increase soil nutrient availability, which would increase microbial process rates and GHG emissions. To test these hypotheses, we measured N2O, CH4 and CO2 fluxes from moss and lichen patches in three burned and unburned areas and collected soil cores for analyses of gravimetric soil moisture, carbon and nitrogen concentrations, and N mineralization rates. Soil temperatures were measured in the field with a thermocouple. Results demonstrated low but measurable CH4 emissions from all patches, suggesting peat plateaus in the YK Delta may be CH4 sources. In addition, CO2 emissions were higher in soils under lichen patches in burned areas than unburned controls. Finally, results suggest that burned areas have higher concentrations of extractable NH4 and NO3, and that increased N may be increasing soil respiration.

  4. Do limiting factors at Alaskan treelines shift with climatic regimes?

    International Nuclear Information System (INIS)

    Ohse, B; Jansen, F; Wilmking, M

    2012-01-01

    Trees at Alaskan treelines are assumed to be limited by temperature and to expand upslope and/or to higher latitudes with global warming. However, recent studies describe negative temperature responses and drought stress of Alaskan treeline trees in recent decades. In this study, we have analyzed the responses of treeline white spruce to temperature and precipitation according to different climatic regimes in Alaska, described as negative (cool) and positive (warm) phases of the Pacific Decadal Oscillation (PDO). We found that in three consecutive phases (positive from 1925–46, negative from 1947–76, and positive again from 1977–98), the growth responses to temperature and precipitation differed markedly. Before 1947, in a phase of warm winters and with summer temperatures being close to the century mean, the trees at most sites responded positively to summer temperature, as one would expect from treeline trees at northern high latitudes. Between 1947 and 1976, a phase of cold winters and average summers, the trees showed similar responses, but a new pattern of negative responses to the summer temperature of the year prior to growth coupled with positive responses to the precipitation in the same year emerged at some sites. As the precipitation was relatively low at those sites, we assume that drought stress might have played a role. However, the climate responses were not uniform but were modified by regional gradients (trees at northern sites responded more often to temperature than trees at southern sites) and local site conditions (forest trees responded more often to precipitation than treeline trees), possibly reflecting differences in energy and water balance across regions and sites, respectively. However, since the shift in the PDO in 1976 from a negative to a positive phase, the trees’ climate–growth responses are much less pronounced and climate seems to have lost its importance as a limiting factor for the growth of treeline white spruce. If

  5. Lessons learned in managing crowdsourced data in the Alaskan Arctic.

    Science.gov (United States)

    Mastracci, Diana

    2017-04-01

    There is perhaps no place in which the consequences of global climate change can be felt more acutely than the Arctic. However, due to lack of measurements at the high latitudes, validation processes are often problematic. Citizen science projects, co-designed together with Native communities at the interface of traditional knowledge and scientific research, could play a major role in climate change adaptation strategies by advancing knowledge of the Arctic system, strengthening inter-generational bonds and facilitating improved knowledge transfer. This presentation will present lessons learned from a pilot project in the Alaskan Arctic, in which innovative approaches were used to design climate change adaptation strategies to support young subsistence hunters in taking in-situ measurements whilst out on the sea-ice. Both the socio-cultural and hardware/software challenges presented in this presentation, could provide useful guidance for future programs that aim to integrate citizens' with scientific data in Arctic communities.

  6. The freshwater biodegradation potential of nine Alaskan oils

    International Nuclear Information System (INIS)

    Blenkinsopp, S.; Segy, G.

    1997-01-01

    Nine Alaskan representative crude oils and oil products with freshwater spill potential were collected, aged, and incubated in the presence of the standard freshwater inoculum for 28 days at 10 degrees C. Detailed analytical chemistry was performed on all samples to quantify compositional changes. All of the samples tested exhibited measurable hydrocarbon loss as a result of incubation with the freshwater inoculum. Total saturate and total n-alkane biodegradation were greatly enhanced when nutrients were present. The oil products Jet B Fuel and Diesel No. 2 appear to be more biodegradable than the Alaska North Slope and Cook Inlet crude oils tested, while the Bunker C/Diesel mixture appears to be less biodegradable than these crude oils. These results suggest that the screening procedures described here can provide useful information when applying bioremediation technology to the cleanup of selected oiled freshwater environments. 10 refs., 5 tabs., 13 figs

  7. 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.

  8. Nitrogen isotopes suggest a change in nitrogen dynamics between the Late Pleistocene and modern time in Yukon, Canada

    Science.gov (United States)

    Longstaffe, Fred J.; Zazula, Grant

    2018-01-01

    A magnificent repository of Late Pleistocene terrestrial megafauna fossils is contained in ice-rich loess deposits of Alaska and Yukon, collectively eastern Beringia. The stable carbon (δ13C) and nitrogen (δ15N) isotope compositions of bone collagen from these fossils are routinely used to determine paleodiet and reconstruct the paleoecosystem. This approach requires consideration of changes in C- and N-isotope dynamics over time and their effects on the terrestrial vegetation isotopic baseline. To test for such changes between the Late Pleistocene and modern time, we compared δ13C and δ15N for vegetation and bone collagen and structural carbonate of some modern, Yukon, arctic ground squirrels with vegetation and bones from Late Pleistocene fossil arctic ground squirrel nests preserved in Yukon loess deposits. The isotopic discrimination between arctic ground squirrel bone collagen and their diet was measured using modern samples, as were isotopic changes during plant decomposition; Over-wintering decomposition of typical vegetation following senescence resulted in a minor change (~0–1 ‰) in δ13C of modern Yukon grasses. A major change (~2–10 ‰) in δ15N was measured for decomposing Yukon grasses thinly covered by loess. As expected, the collagen-diet C-isotope discrimination measured for modern samples confirms that modern vegetation δ13C is a suitable proxy for the Late Pleistocene vegetation in Yukon Territory, after correction for the Suess effect. The N-isotope composition of vegetation from the fossil arctic ground squirrel nests, however, is determined to be ~2.8 ‰ higher than modern grasslands in the region, after correction for decomposition effects. This result suggests a change in N dynamics in this region between the Late Pleistocene and modern time. PMID:29447202

  9. 2000 Yukon North Slope conference : The challenge of change : Summary report

    International Nuclear Information System (INIS)

    2001-01-01

    The proclamation of the Inuvialuit Final Agreement (IFA) took place in 1984, and the protection of the environment of the Yukon North Slope was ensured through new mechanisms provided in the Agreement. The creation of Ivvavik National Park and Herschel Island Territorial Park resulted from section 12 of the Agreement, as well as the Wildlife Management Advisory Council (North Slope). Designated as having a special conservation regime with protection of wildlife, habitat and traditional native use, the entire Yukon North Slope is of paramount importance. Promoting discussion among native organizations, government and the private sector is one of the mandates of the new management regime, under section 12(57) of the IFA. These discussions must deal with management coordination for the North Slope. The sixth Yukon North Slope Conference was held in September 2000, and this document summarizes the proceedings. The document was based on transcripts and reports from workshops held during the conference. In some instances, the material was edited for clarification. Approximately 100 delegates represented various interests ranging from academia to wildlife conservation organizations, from government to native organizations and others. The discussions included topics as varied as oil and gas development, climate change, ecological monitoring, wildlife populations, tourism development, implementation of the IFA, environmental assessment, and protected areas. Some of the recommendations emanating from the conference touched information dissemination on climate change and ecological monitoring, the establishment of a roundtable representing all stakeholders concerning environmental assessments for oil and gas development, and continued support for natives to maintain their cultural values and traditional uses among others. figs., 5 appendices

  10. Population dynamics of Greater Scaup breeding on the Yukon-Kuskokwim Delta, Alaska

    Science.gov (United States)

    Flint, Paul L.; Grand, J. Barry; Fondell, Thomas F.; Morse, Julie A.

    2006-01-01

    Populations of greater scaup (Aythya marila) remained relatively stable during a period when populations of lesser scaup (A. affinis) have declined from historic levels. To assist in describing these differences in population trends, from 1991 through 2000, we studied the survival, nesting ecology, and productivity of greater scaup on the Yukon-Kuskokwim Delta (Y-K Delta), Alaska, to develop a model of population dynamics. We located nests, radio-marked females for renesting studies, estimated duckling survival, and leg-banded females to examine nest site fidelity and annual survival.

  11. A New Wave of Permafrost Warming in the Alaskan Interior?

    Science.gov (United States)

    Romanovsky, V. E.; Nicolsky, D.; Cable, W.; Kholodov, A. L.; Panda, S. K.

    2017-12-01

    The impact of climate warming on permafrost and the potential of climate feedbacks resulting from permafrost thawing have recently received a great deal of attention. Ground temperatures are a primary indicator of permafrost stability. Many of the research sites in our permafrost network are located along the North American Arctic Permafrost-Ecological Transect that spans all permafrost zones in Alaska. Most of the sites in Alaska show substantial warming of permafrost since the 1980s. The magnitude of warming has varied with location, but was typically from 0.5 to 3°C. However, this warming was not linear in time and not spatially uniform. In some regions this warming even may be reversed and a slight recent cooling of permafrost has been observed recently at some locations. The Interior of Alaska is one of such regions where a slight permafrost cooling was observed starting in the late 1990s that has continued through the 2000s and in the beginning of the 2010s. The cooling has followed the substantial increase in permafrost temperatures documented for the Interior during the 1980s and 1990s. Permafrost temperatures at 15 m depth increased here by 0.3 to 0.6°C between 1983 and 1996. In most locations they reached their maximum in the second half of the 1990s. Since then, the permafrost temperatures started to decrease slowly and by 2013 this decrease at some locations was as much as 0.3°C at 15 m depth. There are some indications that the warming trend in the Alaskan Interior permafrost resumed during the last four years. By 2016, new record highs for the entire period of measurements of permafrost temperatures at 15 m depth were recorded at several locations. The latest observed permafrost warming in the Interior was combined with higher than normal summer precipitations. This combination has triggered near-surface permafrost degradation in many locations with adverse consequences for the ground surface stability affecting ecosystems and infrastructure. In

  12. Modelling guided waves in the Alaskan-Aleutian subduction zone

    Science.gov (United States)

    Coulson, Sophie; Garth, Thomas; Reitbrock, Andreas

    2016-04-01

    Subduction zone guided wave arrivals from intermediate depth earthquakes (70-300 km depth) have a huge potential to tell us about the velocity structure of the subducting oceanic crust as it dehydrates at these depths. We see guided waves as the oceanic crust has a slower seismic velocity than the surrounding material, and so high frequency energy is retained and delayed in the crustal material. Lower frequency energy is not retained in this crustal waveguide and so travels at faster velocities of the surrounding material. This gives a unique observation at the surface with low frequency energy arriving before the higher frequencies. We constrain this guided wave dispersion by comparing the waveforms recorded in real subduction zones with simulated waveforms, produced using finite difference full waveform modelling techniques. This method has been used to show that hydrated minerals in the oceanic crust persist to much greater depths than accepted thermal petrological subduction zone models would suggest in Northern Japan (Garth & Rietbrock, 2014a), and South America (Garth & Rietbrock, in prep). These observations also suggest that the subducting oceanic mantle may be highly hydrated at intermediate depth by dipping normal faults (Garth & Rietbrock 2014b). We use this guided wave analysis technique to constrain the velocity structure of the down going ~45 Ma Pacific plate beneath Alaska. Dispersion analysis is primarily carried out on guided wave arrivals recorded on the Alaskan regional seismic network. Earthquake locations from global earthquake catalogues (ISC and PDE) and regional earthquake locations from the AEIC (Alaskan Earthquake Information Centre) catalogue are used to constrain the slab geometry and to identify potentially dispersive events. Dispersed arrivals are seen at stations close to the trench, with high frequency (>2 Hz) arrivals delayed by 2 - 4 seconds. This dispersion is analysed to constrain the velocity and width of the proposed waveguide

  13. Eastern Denali Fault surface trace map, eastern Alaska and Yukon, Canada

    Science.gov (United States)

    Bender, Adrian M.; Haeussler, Peter J.

    2017-05-04

    We map the 385-kilometer (km) long surface trace of the right-lateral, strike-slip Denali Fault between the Totschunda-Denali Fault intersection in Alaska, United States and the village of Haines Junction, Yukon, Canada. In Alaska, digital elevation models based on light detection and ranging and interferometric synthetic aperture radar data enabled our fault mapping at scales of 1:2,000 and 1:10,000, respectively. Lacking such resources in Yukon, we developed new structure-from-motion digital photogrammetry products from legacy aerial photos to map the fault surface trace at a scale of 1:10,000 east of the international border. The section of the fault that we map, referred to as the Eastern Denali Fault, did not rupture during the 2002 Denali Fault earthquake (moment magnitude 7.9). Seismologic, geodetic, and geomorphic evidence, along with a paleoseismic record of past ground-rupturing earthquakes, demonstrate Holocene and contemporary activity on the fault, however. This map of the Eastern Denali Fault surface trace complements other data sets by providing an openly accessible digital interpretation of the location, length, and continuity of the fault’s surface trace based on the accompanying digital topography dataset. Additionally, the digitized fault trace may provide geometric constraints useful for modeling earthquake scenarios and related seismic hazard.

  14. Environmental issues in oil and gas operations in Yukon and in the N.W.T

    International Nuclear Information System (INIS)

    MacWilliam, A.G.

    1999-01-01

    Companies planning an expansion into the two territories ought to examine the way each territory deals with potential environmental issues such as spills, releases, contaminated sites and the reclamation of land. Recent legislation has provided each territory with a certain amount of autonomy, which includes the ability to oversee environmental protection. The Yukon, in particular, has considerable freedom in addressing environmental issues relating to oil and gas activities. Both territories are subject to the input and approval of the federal government and First Nations citizens where their respective interests or lands are involved. An overview is included of the regulation of environmental matters north of the 60th parallel. Although the expansion of oil and gas companies into the two territories 'north of 60' offers new opportunities, operators must consider the potential for environmental issues such as spills, releases, site contamination and reclamation of land. In the Yukon where the government has assumed jurisdiction to regulate oil and gas resources, it is implementing a comprehensive regime to deal with environmental issues, at first, in draft form. In contrast, in the N.W.T. the federal government retains considerable control over gas and oil rights and the consequent environmental issues, and, accordingly, it is essential to be aware of federal environmental regulations for the time being

  15. Cancer incidence and risk in Alaskan natives exposed to radioactive fallout

    International Nuclear Information System (INIS)

    Stutzman, C.D.; Nelson, D.M.

    1986-01-01

    Cancer incidence in northern Alaskan villages exposed to radioactive fallout from nuclear weapons testing in the late 1950s and early 1960s was assessed using data from the Alaskan Native Tumor Registry. Previous studies have shown that cancer incidence in Alaskan natives differs from that in residents of the rest of the United States: rates of cancer of the nasopharynx and liver are higher in Alaskan native men and rates of cancer of the nasopharynx, gallbladder, cervix, and kidney are higher in Alaskan native women. Leukemia, breast cancer and bone sarcoma are the cancers most likely to result from fallout exposure in the Arctic, but the incidence of these cancers in the North Slope villages appeared to be lower than in either the entire Inuit population or the US population. The fallout radionuclides of potential health concern are cesium-137 and strontium-90, because of their abundance, long half-life, and chemical characteristics that facilitate transport through and concentration in the food chain and accumulation in sensitive tissues of the body. Radionuclide body burdens were determined in North Slope Inuit 25 years ago, because of their possible exposure to radioactive fallout via the lichen-caribou-man pathway. Cancer risk estimates have been calculated using highest average dose measurements from residents of Anaktuvuk Pass, under the assumption that peak exposure levels of the mid 1960s remained steady over the following 20 years. Worst-case estimates of expected cancer excess were calculated for leukemia, breast cancer and bone sarcoma

  16. 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

    ... DEPARTMENT OF THE INTERIOR Bureau of Land Management [LLAKF030.16100000.DO0000.LXSILCYK0000] Notice of Intent To Prepare a Resource Management Plan for the Central Yukon Planning Area Alaska and... management. 8. The RMP will be consistent with the Bureau's H-1601-1 Land Use Planning Handbook, Appendix C...

  17. Interannual variability in lower trophic levels on the Alaskan Shelf

    Science.gov (United States)

    Batten, Sonia D.; Raitsos, Dionysios E.; Danielson, Seth; Hopcroft, Russell; Coyle, Kenneth; McQuatters-Gollop, Abigail

    2018-01-01

    This study describes results from the first 16 years of the Continuous Plankton Recorder (CPR) program that has sampled the lower trophic levels (restricted to larger, hard-shelled phytoplankton and robust zooplankton taxa) on the Alaskan shelf. Sampling took place along transects from the open ocean across the shelf (to the entrance to Prince William Sound from 2000 to 2003 and into Cook Inlet from 2004 to 2015) to provide plankton abundance data, spring through autumn of each year. We document interannual variability in concentration and composition of the plankton community of the region over this time period. At least in part and through correlative relationships, this can be attributed to changes in the physical environment, particularly direct and indirect effects of temperature. For example; spring mixed layer depth is shown to influence the timing of the spring diatom peak and warmer years are biased towards smaller copepod species. A significant positive relationship between temperature, diatom abundance and zooplankton biomass existed from 2000 to 2013 but was not present in the warm years of 2014 and 2015. These results suggest that anomalous warming events, such as the "heat wave" of 2014-2015, could fundamentally influence typical lower trophic level patterns, possibly altering trophic interactions.

  18. Emissions of biogenic sulfur gases from Alaskan tundra

    Science.gov (United States)

    Hines, Mark E.; Morrison, Michael C.

    1992-01-01

    Results of sulfur emission measurements made in freshwater and marine wetlands in Alaskan tundra during the Arctic Boundary Layer Expedition 2A (ABLE 3A) in July 1988 are presented. The data indicate that this type of tundra emits very small amounts of gaseous sulfur and, when extrapolated globally, accounts for a very small percentage of the global flux of biogenic sulfur to the atmosphere. Sulfur emissions from marine sites are up to 20-fold greater than fluxes from freshwater habitats and are dominated by dimethyl sulfide (DMS). Highest emissions, with a mean of 6.0 nmol/sq m/h, occurred in water-saturated wet meadow areas. In drier upland tundra sites, highest fluxes occurred in areas inhabited by mixed vegetation and labrador tea at 3.0 nmol/sq m/h and lowest fluxes were from lichen-dominated areas at 0.9 nmol/sq m/h. DMS was the dominant gas emitted from all these sites. Emissions of DMS were highest from intertidal soils inhabited by Carex subspathacea.

  19. 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.

  20. 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

  1. 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.

  2. Exporting Alaskan North Slope crude oil: Benefits and costs

    Energy Technology Data Exchange (ETDEWEB)

    1994-06-01

    The Department of Energy study examines the effects of lifting the current prohibitions against the export of Alaskan North Slope (ANS) crude. The study concludes that permitting exports would benefit the US economy. First, lifting the ban would expand the markets in which ANS oil can be sold, thereby increasing its value. ANS oil producers, the States of California and Alaska, and some of their local governments all would benefit from increased revenues. Permitting exports also would generate new economic activity and employment in California and Alaska. The study concludes that these economic benefits would be achieved without increasing gasoline prices (either in California or in the nation as a whole). Lifting the export ban could have important implications for US maritime interests. The Merchant Marine Act of 1970 (known as the Jones Act) requires all inter-coastal shipments to be carried on vessels that are US-owned, US-crewed, and US-built. By limiting the shipment of ANS crude to US ports only, the export ban creates jobs for the seafarers and the builders of Jones Act vessels. Because the Jones Act does not apply to exports, however, lifting the ban without also changing US maritime law would jeopardize the jobs associated with the current fleet of Jones Act tankers. Therefore the report analyzes selected economic impacts of several maritime policy alternatives, including: Maintaining current law, which allows foreign tankers to carry oil where export is allowed; requiring exports of ANS crude to be carried on Jones Act vessels; and requiring exports of ANS crude to be carried on vessels that are US-owned and US-crewed, but not necessarily US-built. Under each of these options, lifting the export ban would generate economic benefits.

  3. Inorganic and organic contaminants in Alaskan shorebird eggs.

    Science.gov (United States)

    Saalfeld, David T; Matz, Angela C; McCaffery, Brian J; Johnson, Oscar W; Bruner, Phil; Lanctot, Richard B

    2016-05-01

    Many shorebird populations throughout North America are thought to be declining, with potential causes attributed to habitat loss and fragmentation, reduced prey availability, increased predation, human disturbance, and increased exposure to environmental pollutants. Shorebirds may be particularly vulnerable to contaminant exposure throughout their life cycle, as they forage primarily on invertebrates in wetlands, where many contaminants accumulate disproportionately in the sediments. Therefore, it is important to document and monitor shorebird populations thought to be at risk and assess the role that environmental contaminants may have on population declines. To investigate potential threats and provide baseline data on shorebird contaminant levels in Alaskan shorebirds, contaminant concentrations were evaluated in shorebird eggs from 16 species residing in seven geographic distinct regions of Alaska. Similar to previous studies, low levels of most inorganic and organic contaminants were found, although concentrations of several inorganic and organic contaminants were higher than those of previous studies. For example, elevated strontium levels were observed in several species, especially black oystercatcher (Haematopus bachmani) sampled in Prince William Sound, Alaska. Additionally, contaminant concentrations varied among species, with significantly higher concentrations of inorganic contaminants found in eggs of pectoral sandpiper (Calidris melanotos), semipalmated sandpiper (Calidris pusilla), black oystercatcher, and bar-tailed godwit (Limosa lapponica). Similarly, significantly higher concentrations of some organic contaminants were found in the eggs of American golden plover (Pluvialis dominica), black-bellied plover (Pluvialis squatarola), pacific golden plover (Pluvialis fulva), bar-tailed godwit, and semipalmated sandpiper. Despite these elevated levels, current concentrations of contaminants in shorebird eggs suggest that breeding environments are

  4. Hygroscopicity and composition of Alaskan Arctic CCN during April 2008

    Directory of Open Access Journals (Sweden)

    R. H. Moore

    2011-11-01

    Full Text Available We present a comprehensive characterization of cloud condensation nuclei (CCN sampled in the Alaskan Arctic during the 2008 Aerosol, Radiation, and Cloud Processes affecting Arctic Climate (ARCPAC project, a component of the POLARCAT and International Polar Year (IPY initiatives. Four distinct air mass types were sampled including a cleaner Arctic background and a relatively pristine sea ice boundary layer as well as biomass burning and anthropogenic pollution plumes. Despite differences in chemical composition, inferred aerosol hygroscopicities were fairly invariant and ranged from κ = 0.1–0.3 over the atmospherically-relevant range of water vapor supersaturations studied. Organic aerosols sampled were found to be well-oxygenated, consistent with long-range transport and aerosol aging processes. However, inferred hygroscopicities are less than would be predicted based on previous parameterizations of biogenic oxygenated organic aerosol, suggesting an upper limit on organic aerosol hygroscopicity above which κ is less sensitive to the O:C ratio. Most Arctic aerosols act as CCN above 0.1 % supersaturation, although the data suggest the presence of an externally-mixed, non-CCN-active mode comprising approximately 0–20% of the aerosol number. CCN closure was assessed using measured size distributions, bulk chemical composition, and assumed aerosol mixing states; CCN predictions tended toward overprediction, with the best agreement (±0–20 % obtained by assuming the aerosol to be externally-mixed with soluble organics. Closure also varied with CCN concentration, and the best agreement was found for CCN concentrations above 100 cm−3 with a 1.5- to 3-fold overprediction at lower concentrations.

  5. Exporting Alaskan North Slope crude oil: Benefits and costs

    International Nuclear Information System (INIS)

    1994-06-01

    The Department of Energy study examines the effects of lifting the current prohibitions against the export of Alaskan North Slope (ANS) crude. The study concludes that permitting exports would benefit the US economy. First, lifting the ban would expand the markets in which ANS oil can be sold, thereby increasing its value. ANS oil producers, the States of California and Alaska, and some of their local governments all would benefit from increased revenues. Permitting exports also would generate new economic activity and employment in California and Alaska. The study concludes that these economic benefits would be achieved without increasing gasoline prices (either in California or in the nation as a whole). Lifting the export ban could have important implications for US maritime interests. The Merchant Marine Act of 1970 (known as the Jones Act) requires all inter-coastal shipments to be carried on vessels that are US-owned, US-crewed, and US-built. By limiting the shipment of ANS crude to US ports only, the export ban creates jobs for the seafarers and the builders of Jones Act vessels. Because the Jones Act does not apply to exports, however, lifting the ban without also changing US maritime law would jeopardize the jobs associated with the current fleet of Jones Act tankers. Therefore the report analyzes selected economic impacts of several maritime policy alternatives, including: Maintaining current law, which allows foreign tankers to carry oil where export is allowed; requiring exports of ANS crude to be carried on Jones Act vessels; and requiring exports of ANS crude to be carried on vessels that are US-owned and US-crewed, but not necessarily US-built. Under each of these options, lifting the export ban would generate economic benefits

  6. Densities of breeding birds and changes in vegetation in an alaskan boreal forest following a massive disturbance by spruce beetles

    Science.gov (United States)

    Matsuoka, S.M.; Handel, C.M.; Ruthrauff, D.R.

    2001-01-01

    We examined bird and plant communities among forest stands with different levels of spruce mortality following a large outbreak of spruce beetles (Dendroctonus rufipennis (Kirby)) in the Copper River Basin, Alaska. Spruce beetles avoided stands with black spruce (Picea mariana) and selectively killed larger diameter white spruce (Picea glauca), thereby altering forest structure and increasing the dominance of black spruce in the region. Alders (Alnus sp.) and crowberry (Empetrum nigrum) were more abundant in areas with heavy spruce mortality, possibly a response to the death of overstory spruce. Grasses and herbaceous plants did not proliferate as has been recorded following outbreaks in more coastal Alaskan forests. Two species closely tied to coniferous habitats, the tree-nesting Ruby-crowned Kinglet (Regulus calendula) and the red squirrel (Tamiasciurus hudsonicus), a major nest predator, were less abundant in forest stands with high spruce mortality than in low-mortality stands. Understory-nesting birds as a group were more abundant in forest stands with high levels of spruce mortality, although the response of individual bird species to tree mortality was variable. Birds breeding in stands with high spruce mortality likely benefited reproductively from lower squirrel densities and a greater abundance of shrubs to conceal nests from predators.

  7. Renesting ecology of northern pintails on the Yukon-Kuskokwim Delta, Alaska

    Science.gov (United States)

    Grand, James B.; Flint, Paul L.

    1996-01-01

    We used radio telemetry to study renesting by wild, free-ranging Northern Pintails (Anas acuta) on the coastal Yukon-Kuskokwim Delta in 1994 and 1995. Fifty-six percent of females (n = 39) renested at least once. Propensity to renest declined among females that initiated later first nests. Renesting interval was not related to female weight, year, or initiation date of first nests. Mean interval between first and second nests was 11.4 ± 1.0 days, and mean interval between second and third nests was 11.3 ± 1.5 days. Median distance observed between first and second nest attempts was 276 m (range 33-6,098 m). Clutch size declined 2.3 ± 0.4 eggs between first and second nests. Weight of females captured on first nests in early incubation declined with nest initiation date. Our results suggest that food availability does not limit renesting ability of pintails in coastal tundra.

  8. Summary report of a workshop on establishing cumulative effects thresholds : a suggested approach for establishing cumulative effects thresholds in a Yukon context

    International Nuclear Information System (INIS)

    2003-01-01

    Increasingly, thresholds are being used as a land and cumulative effects assessment and management tool. To assist in the management of wildlife species such as woodland caribou, the Department of Indian and Northern Affairs (DIAND) Environment Directorate, Yukon sponsored a workshop to develop and use cumulative thresholds in the Yukon. The approximately 30 participants reviewed recent initiatives in the Yukon and other jurisdictions. The workshop is expected to help formulate a strategic vision for implementing cumulative effects thresholds in the Yukon. The key to success resides in building relationships with Umbrella Final Agreement (UFA) Boards, the Development Assessment Process (DAP), and the Yukon Environmental and Socio-Economic Assessment Act (YESAA). Broad support is required within an integrated resource management framework. The workshop featured discussions on current science and theory of cumulative effects thresholds. Potential data and implementation issues were also discussed. It was concluded that thresholds are useful and scientifically defensible. The threshold research results obtained in Alberta, British Columbia and the Northwest Territories are applicable to the Yukon. One of the best tools for establishing and tracking thresholds is habitat effectiveness. Effects must be monitored and tracked. Biologists must share their information with decision makers. Interagency coordination and assistance should be facilitated through the establishment of working groups. Regional land use plans should include thresholds. 7 refs.

  9. Geology and assessment of undiscovered oil and gas resources of the Yukon Flats Basin Province, 2008

    Science.gov (United States)

    Bird, Kenneth J.; Stanley, Richard G.; Moore, Thomas E.; Gautier, Donald L.

    2017-12-22

    The hydrocarbon potential of the Yukon Flats Basin Province in Central Alaska was assessed in 2004 as part of an update to the National Oil and Gas Assessment. Three assessment units (AUs) were identified and assessed using a methodology somewhat different than that of the 2008 Circum-Arctic Resource Appraisal (CARA). An important difference in the methodology of the two assessments is that the 2004 assessment specified a minimum accumulation size of 0.5 million barrels of oil equivalent (MMBOE), whereas the 2008 CARA assessment specified a minimum size of 50 MMBOE. The 2004 assessment concluded that >95 percent of the estimated mean undiscovered oil and gas resources occur in a single AU, the Tertiary Sandstone AU. This is also the only AU of the three that extends north of the Arctic Circle.For the CARA project, the number of oil and gas accumulations in the 2004 assessment of the Tertiary Sandstone AU was re-evaluated in terms of the >50-MMBOE minimum accumulation size. By this analysis, and assuming the resource to be evenly distributed across the AU, 0.23 oil fields and 1.20 gas fields larger than 50 MMBOE are expected in the part of the AU north of the Arctic Circle. The geology suggests, however, that the area north of the Arctic Circle has a lower potential for oil and gas accumulations than the area to the south where the sedimentary section is thicker, larger volumes of hydrocarbons may have been generated, and potential structural traps are probably more abundant. Because of the low potential implied for the area of the AU north of the Arctic Circle, the Yukon Flats Tertiary Sandstone AU was not quantitatively assessed for the 2008 CARA.

  10. 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.

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

    International Nuclear Information System (INIS)

    Gamberg, Mary; Boila, Gail; Stern, Gary; Roach, Patrick

    2005-01-01

    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 μg g -1 in mink kidney, liver and brain tissue respectively, while methyl mercury averaged 0.77, 0.85 and 0.21 μg g -1 in the same tissues. Selenium averaged 2.07, 1.40 and 0.39 μg g -1 in mink kidney, liver and brain tissue, while cadmium was only measured in kidneys and averaged 0.22 μg g -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

  12. 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…

  13. A study of unstable slopes in permafrost areas : Alaskan case studies used as a training tool.

    Science.gov (United States)

    2011-12-01

    This report is the companion to the PowerPoint presentation for the project A Study of Unstable Slopes in Permafrost: Alaskan Case Studies Used as a Training Tool. The objectives of this study are 1) to provide a comprehensive review of literat...

  14. Geochemical evidences of methane hydrate dissociation in Alaskan Beaufort Margin during Holocene

    Science.gov (United States)

    Uchida, M.; Rella, S.; Kubota, Y.; Kumata, H.; Mantoku, K.; Nishino, S.; Itoh, M.

    2017-12-01

    Alaskan Beaufort margin bear large abundances of sub-sea and permafrost methane hydrate[Ruppel, 2016]. During the Last Glacial, previous reported direct and indirect evidences accumulated from geochemical data from marginal sea sediment suggests that methane episodically released from hydrate trapped in the seafloor sediments[Kennett et al., 2000; Uchida et al., 2006, 2008; Cook et al, 2011]. Here we analyzed stable isotopes of foraminifera and molecular marker derived from the activity of methanotrophic bacteria from piston cores collected by the 2010 R/V Mirai cruise in Alaskan Beaufort Margin. Our data showed highly depleted 13C compositions of benthic foraminifera, suggesting indirect records of enhanced incorporation of 13C-depleted CO2 formed by methanotrophic process that use 12C-enriched methane as their main source of carbon. This is the first evidence of methane hydrate dissociation in Alaskan margin. Here we discussed timing of signals of methane dissociation with variability of sea ice and intermediate Atlantic water temperature. The dissociation of methane hydrate in the Alaskan Margin may be modulated by Atlantic warm intermediate water warming. Our results suggest that Arctic marginal regions bearing large amount methane hydrate may be a profound effect on future warming climate changes.

  15. 77 FR 45921 - Alaskan Fuel Hauling as a Restricted Category Special Purpose Flight Operation

    Science.gov (United States)

    2012-08-02

    ... operations, each aircraft used to transport fuel will be required to receive FAA certification for the... regulations. The special purpose of Alaskan fuel hauling was considered for aircraft type-certificated under... required for this special purpose. The fuel hauling system must be shown to meet the applicable...

  16. An assessment of educational needs in the Alaskan forest products industry.

    Science.gov (United States)

    Jon Thomas; Eric Hansen; Allen M. Brackley

    2005-01-01

    Major changes in federal forest policy in Alaska have resulted in a dramatic downsizing of the state's forest industry. These changes have driven efforts for economic restructuring and improved support for Alaskan communities. The University of Alaska Sitka Forest Products program at the University of Alaska Southeast is one example of efforts to better support...

  17. Implications of lifting the ban on the export of Alaskan crude oil

    Energy Technology Data Exchange (ETDEWEB)

    1990-03-26

    Present legislation effectively bans the export of crude oil produced in the United States. The ban has been in effect for years and is particularly stringent with respect to crude oil produced in Alaska, particularly on the North Slope. The Alaska crude export ban is specifically provided for in the Trans-Alaska Pipeline Authorization Act of 1973 and in other legislation. It was imposed for two reasons. The first was to reduce US dependence on imported crude oil. The Arab oil embargo had been imposed shortly before the Act was passed and a greater measure of energy independence was considered imperative at that time. The second reason was to assure that funds expended in building an Alaskan pipeline would benefit domestic users rather than simply employed to facilitate shipments to other countries. The main objective of this report is to estimate the potential impacts on crude oil prices that would result from lifting the export ban Alaskan crude oil. The report focuses on the Japanese market and the US West Coast market. Japan is the principal potential export market for Alaskan crude oil. Exports to that market would also affect the price of Alaskan crude oil as well as crude oil and product prices on the West Coast and the volume of petroleum imported in that area. 3 figs., 8 tabs.

  18. Sarcocystis arctica (Apicomplexa: Sarcocystidae): ultrastructural description and its new host record, the Alaskan wolf (Canis lupus

    Science.gov (United States)

    Sarcocystis sarcocysts are common in muscles of herbivores but are rare in muscles of carnivores. Here, we report sarcocysts in muscle of an Alaskan wolf (Canis lupus) from Alaska, USA for the first time. Sarcocysts extracted from tongue of the wolf were up to 900 µm long, slender, and appeared to h...

  19. 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

  20. Controls on Ecosystem and Root Respiration in an Alaskan Peatland

    Science.gov (United States)

    McConnell, N. A.; McGuire, A. D.; Harden, J. W.; Kane, E. S.; Turetsky, M. R.

    2010-12-01

    Boreal ecosystems cover 14% of the vegetated surface on earth and account for 25-30% of the world’s soil carbon (C), mainly due to large carbon stocks in deep peat and frozen soil layers. While peatlands have served as historical sinks of carbon, global climate change may trigger re-release of C to the atmosphere and may turn these ecosystems into net C sources. Rates of C release from a peatland are determined by regional climate and local biotic and abiotic factors such as vegetation cover, thaw depth, and peat thickness. Soil CO2 fluxes are driven by both autotrophic (plant) respiration and heterotrophic (microbial) respiration. Thus, changes in plant and microbial activity in the soil will impact CO2 emissions from peatlands. In this study, we explored environmental and vegetation controls on ecosystem respiration and root respiration in a variety of wetland sites. The study was conducted at the Alaskan Peatland Experiment (APEX; www.uoguelph.ca/APEX) sites in the Bonanza Creek Experimental Forest located 35 km southwest of Fairbanks Alaska. We measured ecosystem respiration, root respiration, and monitored a suite of environmental variables along a vegetation and soil moisture gradient including a black spruce stand with permafrost, a shrubby site with permafrost, a tussock grass site, and a herbaceous open rich fen. Within the rich fen, we have been conducting water table manipulations including a control, lowered, and raised water table treatment. In each of our sites, we measured total ecosystem respiration using static chambers and root respiration by harvesting roots from the uppermost 20 cm and placing them in a root cuvette to obtain a root flux. Ecosystem respiration (ER) on a μmol/m2/sec basis varied across sites. Water table was a significant predictor of ER at the lowered manipulation site and temperature was a strong predictor at the control site in the rich fen. Water table and temperature were both significant predictors of ER at the raised

  1. Demographic change, economic conditions, and subsistence salmon harvests in Alaska’s Arctic-Yukon-Kuskokwim region

    OpenAIRE

    Howe, E. Lance; Martin, Stephanie

    2009-01-01

    This paper addresses broad demographic and economic characteristics of the Arctic-Yukon-Kuskokwim region (AYK) of Alaska. AYK human population growth has generally been moderate over time. Because out-migration regularly exceeds in-migration, especially in the villages, population growth is mainly a product of natality. We anticipate future population growth patterns will be similar. In terms of regional characteristics, the linguistically and geographically distinct populations of the AYK re...

  2. Potential effects of ocean acidification on Alaskan corals based on calcium carbonate mineralogy composition analysis (NCEI Accession 0157223)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This archival package contains potential effects of ocean acidification on Alaskan corals based on calcium carbonate mineralogy composition analysis. Effects of...

  3. Spectral Assessment of Soil Properties: Standoff Quantification of Soil Organic Matter Content in Surface Mineral Soils and Alaskan Peat

    Science.gov (United States)

    2017-08-01

    Soil Properties Standoff Quantification of Soil Organic Matter Content in Surface Mineral Soils and Alaskan Peat En gi ne er R es ea rc h an d D...ERDC 6.2 GRE ARTEMIS STO-R DRTSPORE ERDC TR-17-9 August 2017 Spectral Assessment of Soil Properties Standoff Quantification of Soil Organic...Matter Content in Surface Mineral Soils and Alaskan Peat Stacey L. Jarvis, Karen L. Foley, Robert M. Jones, Stephen D. Newman, and Robyn A. Barbato

  4. Impact of disability and other physical health issues on academic outcomes among American Indian and Alaskan Native college students: an exploratory analysis.

    Science.gov (United States)

    Patterson Silver Wolf Adelv Unegv Waya, David A; Vanzile-Tamsen, Carol; Black, Jessica; Billiot, Shanondora M; Tovar, Molly

    2015-01-01

    This study investigated whether self-identified disabilities among American Indian and Alaskan Native college students impact academic performance and persistence to graduation and explored the differences in health and academic grades between American Indian and Alaskan Native students and students of other racial and ethnic identities using the National College Health Assessment. Findings indicate that American Indian or Alaskan Native students have significantly lower grades than White and Asian students, and American Indian and Alaskan Native women report the highest incidence of health problems of any demographic group. Exploratory results point to future research to determine the full impact of disabilities and poor health on academic success.

  5. Survival of breeding Pacific common eiders on the Yukon-Kuskokwim Delta, Alaska

    Science.gov (United States)

    Wilson, H.M.; Flint, Paul L.; Moran, Christine L.; Powell, A.N.

    2007-01-01

    Populations of Pacific common eiders (Somateria mollissima v-nigrum) breeding in Alaska, USA, have declined markedly over the past 40 years. We studied survival of adult female Pacific common eiders using capture—recapture of nesting hens at 3 sites on the Yukon-Kuskokwim Delta (YKD), Alaska from 1994 to 2004. We used data consisting of 268 recapture events from 361 uniquely marked individuals to investigate temporal, geographic, and environmental variation in adult female survival. Our results suggest apparent annual survival of adult eiders from the YKD was high (0.892, SE = 0.022) and spatially and temporally invariant (σ2 = 0.005), a pattern consistent with other long-lived marine birds. Moreover, our results suggest adult survival may be functionally fixed for Pacific common eiders, and at the present, adult survival may be relatively unresponsive to environmental or management perturbations. Our data did not support hypothesized variation in survival relative to mortality factors such as predation on breeding grounds, physiologic costs of reproduction, and wintering conditions. Although changes in adult survival likely have a large potential effect on prospective population growth, our results suggest viable management actions aimed at increasing survival may be extremely limited.

  6. Pattern-process interactions at alpine treeline in southwest Yukon, Canada

    Science.gov (United States)

    Danby, R.

    2011-12-01

    Results from an ensemble of studies conduced in southwest Yukon have uncovered a distinct "top-down/bottom-up" interaction at alpine treeline whereby terrain-induced gradients of solar radiation result in fundamental differences in plant-scale biological processes which, in turn, structure vegetation pattern at the landscape scale. Varied insolation creates differences in snow depth and timing of melt, soil temperature, and permafrost on opposing slopes that result in distinct physiological differences in white spruce (Picea glauca), the dominant treeline conifer. Measurement of young individuals indicated that secondary growth and lateral growth was significantly greater on south-facing slopes. Photosynthetic efficiency was reduced in individuals on south-facing slopes, while over-winter damage and mortality was significantly greater. Population-level processes also differed. Dendroecology and repeat photography indicated that treeline advanced on south-facing slopes during the 20th century, but that range expansion was limited on north-facing slopes. These process-related differences appear to be the mechanism for differences in treeline pattern at the landscape scale, including a higher treeline elevation and greater clustering of individuals on south-facing slopes. These results can be used to inform theory on the functional causation of treeline, rationalize differential treeline dynamics observed worldwide, and better inform predictions of future treeline dynamics.

  7. Landscape Hazards in Yukon Communities: Geological Mapping for Climate Change Adaptation Planning

    Science.gov (United States)

    Kennedy, K.; Kinnear, L.

    2010-12-01

    Climate change is considered to be a significant challenge for northern communities where the effects of increased temperature and climate variability are beginning to affect infrastructure and livelihoods (Arctic Climate Impact Assessment, 2004). Planning for and adapting to ongoing and future changes in climate will require the identification and characterization of social, economic, cultural, political and biophysical vulnerabilities. This pilot project addresses physical landscape vulnerabilities in two communities in the Yukon Territory through community-scale landscape hazard mapping and focused investigations of community permafrost conditions. Landscape hazards are identified by combining pre-existing data from public utilities and private-sector consultants with new geophysical techniques (ground penetrating radar and electrical resistivity), shallow drilling, surficial geological mapping, and permafrost characterization. Existing landscape vulnerabilities are evaluated based on their potential for hazard (low, medium or high) under current climate conditions, as well as under future climate scenarios. Detailed hazard maps and landscape characterizations for both communities will contribute to overall adaptation plans and allow for informed development, planning and mitigation of potentially threatening hazards in and around the communities.

  8. Tintina Gold Province Study, Alaska and Yukon Territory, 2002-2007

    Science.gov (United States)

    Gough, Larry P.; Day, Warren C.

    2007-01-01

    The Tintina gold province is an arc-shaped 2,000-kilometer-long metallogenic province that extends from northern British Columbia, through the Yukon Territory, and across and into southwestern Alaska. In the United States, the province remains a prime area for gold exploration and includes such large gold deposits as Pogo, Fort Knox-True North, and Donlin Creek. In recent years, gold exploration and development and mining activity have accelerated in the area. Plans have been discussed for public and private projects and infrastructures associated with development. A U.S. Geological Survey study undertaken from 2002 to 2007 provides a context for understanding why and how the mineral resources of the area were formed, why this area is so abundantly endowed, and how the environmental signatures that are characteristic of the area are related to the development of mineral resources. Characterization of natural baseline metal concentrations in the area's watersheds is necessary to address future land-use issues related to mining and/or infrastructure activities. A thorough understanding of water-rock and element-bioavailability processes will help predict the possible environmental impact of development. The five tasks of this study add to the science of defining and understanding an 'intrusion-related gold system.'

  9. Holocene Paleoceanographic Environments at the Chukchi-Alaskan Margin: Implications for Future Changes

    Science.gov (United States)

    Polyak, L.; Nam, S. I.; Dipre, G.; Kim, S. Y.; Ortiz, J. D.; Darby, D. A.

    2017-12-01

    The impacts of the North Pacific oceanic and atmospheric system on the Arctic Ocean result in accelerated sea-ice retreat and related changes in hydrography and biota in the western Arctic. Paleoclimatic records from the Pacific sector of the Arctic are key for understanding the long-term history of these interactions. As opposed to stratigraphically long but strongly compressed sediment cores recovered from the deep Arctic Ocean, sediment depocenters on the Chukchi-Alaskan margin yield continuous, medium to high resolution records formed since the last deglaciation. While early Holocene conditions were non-analogous to modern environments due to the effects of prolonged deglaciation and insufficiently high sea levels, mid to late Holocene sediments are more relevant for recent and modern climate variability. Notably, a large depocenter at the Alaskan margin has sedimentation rates estimated as high as a few millimeters per year, thus providing a decadal to near-annual resolution. This high accumulation can be explained by sediment delivery via the Alaskan Coastal Current originating from the Bering Sea and supposedly controlled by the Aleutian Low pressure center. Preliminary results from sediment cores recovering the last several centuries, along with a comparison with other paleoclimatic proxy records from the Arctic-North Pacific region, indicate a persistent role of the Aleutian Low in the Bering Strait inflow and attendant deposition. More proxy studies are underway to reconstruct the history of this circulation system and its relationship with sea ice extent. The expected results will improve our understanding of natural variability in oceanic and atmospheric conditions at the Chukchi-Alaskan margin, a critical area for modulating the Arctic climate change.

  10. 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 A.; 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 naïveté of both populations to other pathogens (e.g., morbillivirus

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

    Science.gov (United States)

    Hanni, Krista D; Mazet, Jonna A K; Gulland, Frances M D; Estes, James; Staedler, Michelle; Murray, Michael J; Miller, Melissa; Jessup, David A

    2003-10-01

    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 naïveté of both populations to other pathogens (e.g., morbillivirus

  12. 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.

  13. Trophic dynamics in marine nearshore systems of the Alaskan high arctic

    International Nuclear Information System (INIS)

    Dunton, K.H.

    1985-01-01

    This dissertation describes two ecological studies in the arctic Alaskan nearshore zone: the productivity and growth strategies of arctic kelp and the use of natural carbon isotope abundances to examine food web structure and energy flow in the marine ecosystem. Linear growth of the kelp, Laminaria solidungula is greatest in winter and early spring when nutrients are available for new tissue growth. Since over 90% of this growth occurs in complete darkness beneath a turbid ice canopy, the plant draws on stored food reserves and is in a carbon deficit during the ice covered period. Annual productivity of L. solidungula under these conditions is about 6 g C m -2 compared to about 10 g c m -2 if light penetrates the ice canopy. Carbon isotope abundances were used to assess food web structure and energy flow in the Boulder Patch, an isolated kelp bed community, and in the Alaskan Beaufort Sea fauna. Isotopic analyses of the resident fauna of the Boulder Patch revealed that kelp carbon contributes significantly to the diet of many benthic animals, including suspension feeders. Across the shelf of the Alaskan Beaufort Sea, a distinct gradient in the isotopic composition of marine zooplankton and benthic fauna was related to the intrusion of the Bering Sea water and upwelling in the eastern Beaufort Sea near Barter Island. The 13 C depletion in fauna of the eastern Beaufort Sea is presumed due to the cycling of 13 C depleted inorganic carbon into the euphotic zone

  14. 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.

  15. Population decline in the Delta caribou herd with reference to other Alaskan herds

    Directory of Open Access Journals (Sweden)

    Patrick Valkenburg et al.

    1996-01-01

    Full Text Available After growing continuously for nearly 15 years, the Delta caribou herd began to decline in 1989. Most other Interior Alaskan herds also began declining. In the Delta herd, and in other herds, the declines were caused primarily by high summer mortality of calves and increased natural mortality of adult females. Other minor causes included increased winter mortality of calves, and reduced parturition rates of 3-year-old and older females. The decline in the Delta herd also coincided with increased wolf (Canis lupus numbers, winters with deeper than normal snow, and warm summers. Mean body weight of annual samples of 10-month-old female calves was consistently low during the decline. Except in some of the smallest Interior Alaskan herds, we conclude that evidence for population regulation in Alaskan caribou is weak, and that herds are likely to fluctuate within a wide range of densities due to complex interactions of predation and weather. Unless wolf numbers are influenced by man, the size of a caribou herd in a given year is likely to be largely a function of its size during the previous population low and the number of years of favorable weather in the interim.

  16. Seasonality of the late Pleistocene Dawson tephra and exceptional preservation of a buried riparian surface in central Yukon Territory, Canada

    Science.gov (United States)

    Froese, Duane G.; Zazula, Grant D.; Reyes, Alberto V.

    2006-07-01

    The late Pleistocene Dawson tephra was deposited by one of the largest Quaternary eruptions in northwestern North America. Its distribution is known sparsely from sites near the source area in southwestern Alaska and central Yukon Territory, where more than 20 occurrences are documented in the Klondike region. Dawson tephra erupted about 25,300C yr BP, near the onset of the last glaciation, and provides a stratigraphic marker across Eastern Beringia. We report radiocarbon ages, paleobotanical data, and cryostratigraphic observations from a new Dawson tephra locale at Goldbottom Creek, in the Klondike region of Yukon Territory, which collectively indicate that the eruption occurred in the late winter or early spring. Multiple, fining-upward tephra-rich ice beds are interpreted as remnants of surface icings, which presently are common in the region during spring. A buried in situ riparian meadow, preserved below the icing and tephra, consists of abundant tufted hair grass ( Deschampsia caespitosa), with interspersed horsetails ( Equisetum cf. palustre) and mosses. Detrital plant remains and preserved in situ grass inflorescences entombed in the icing had expelled their fruits, consistent with a late season surface when the icing was active. The extraordinary thickness of Dawson tephra in central Yukon likely reflects reworking of a winter-deposited tephra by snow melt in the spring following the eruption, indicating that the primary thickness may be overestimated at valley-bottom sites. Winter deposition of the tephra may have, in part, minimized the terrestrial ecological impacts of the eruption on zonal "steppe-tundra" vegetation through the retransportation of tephra from hillslopes to the riparian areas, where the tephra became incorporated into local fluvial systems.

  17. Apatite fission-track evidence of widespread Eocene heating and exhumation in the Yukon-Tanana Upland, interior Alaska

    Science.gov (United States)

    Dusel-Bacon, C.; Murphy, J.M.

    2001-01-01

    We present an apatite fission-track (AFT) study of five plutonic rocks and seven metamorphic rocks across 310 km of the Yukon-Tanana Upland in east-central Alaska. Samples yielding ???40 Ma AFT ages and mean confined track lengths > 14 ??m with low standard deviations cooled rapidly from >120??C to 40 Ma suggest partial annealing and, therefore, lower maximum temperatures (???90-105??C). A few samples with single-grain ages of ???20 Ma apparently remained above ???50??C after initial cooling. Although the present geothermal gradient in the western Yukon-Tanana Upland is ???32??C/km, it could have been as high as 45??C/km during a widespread Eocene intraplate magmatic episode. Prior to rapid exhumation, samples with ???40 Ma AFT ages were >3.8-2.7 km deep and samples with >50 Ma AFT ages were >3.3-2.0 km deep. We calculate a 440-320 m/Ma minimum rate for exhumation of all samples during rapid cooling. Our AFT data, and data from rocks north of Fairbanks and from the Eielson deep test hole, indicate up to 3 km of post-40 Ma vertical displacement along known and inferred northeast-trending high-angle faults. The predominance of 40-50 Ma AFT ages throughout the Yukon-Tanana Upland indicates that, prior to the post-40 Ma relative uplift along some northeast-trending faults, rapid regional cooling and exhumation closely followed the Eocene extensional magmatism. We propose that Eocene magmatism and exhumation were somehow related to plate movements that produced regional-scale oroclinal rotation, northward translation of outboard terranes, major dextral strike-slip faulting, and subduction of an oceanic spreading ridge along the southern margin of Alaska.

  18. Air and Ground Surface Temperature Relations in a Mountainous Basin, Wolf Creek, Yukon Territory

    Science.gov (United States)

    Roadhouse, Emily A.

    The links between climate and permafrost are well known, but the precise nature of the relationship between air and ground temperatures remains poorly understood, particularly in complex mountain environments. Although previous studies indicate that elevation and potential incoming solar radiation (PISR) are the two leading factors contributing to the existence of permafrost at a given location, additional factors may also contribute significantly to the existence of mountain permafrost, including vegetation cover, snow accumulation and the degree to which individual mountain landscapes are prone to air temperature inversions. Current mountain permafrost models consider only elevation and aspect, and have not been able to deal with inversion effects in a systematic fashion. This thesis explores the relationship between air and ground surface temperatures and the presence of surface-based inversions at 27 sites within the Wolf Creek basin and surrounding area between 2001 and 2006, as a first step in developing an improved permafrost distribution TTOP model. The TTOP model describes the relationship between the mean annual air temperature and the temperature at the top of permafrost in terms of the surface and thermal offsets (Smith and Riseborough, 2002). Key components of this model are n-factors which relate air and ground climate by establishing the ratio between air and surface freezing (winter) and thawing (summer) degree-days, thus summarizing the surface energy balance on a seasonal basis. Here we examine (1) surface offsets and (2) freezing and thawing n-factor variability at a number of sites through altitudinal treeline in the southern Yukon. Thawing n-factors (nt) measured at individual sites remained relatively constant from one year to the next and may be related to land cover. During the winter, the insulating effect of a thick snow cover results in higher surface temperatures, while thin snow cover results in low surface temperatures more closely

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

    Science.gov (United States)

    Abraham, Jared E.

    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.

  20. Annual survival and site fidelity of northern pintails banded on the Yukon-Kuskokwim Delta, Alaska

    Science.gov (United States)

    Nicolai, Christopher A.; Flint, Paul L.; Wege, Michael L.

    2005-01-01

    We banded northern pintails (Anas acuta; n = 13,645) at a single site on the Yukon-Kuskokwim Delta (YKD), Alaska, USA, from 1990 to 2001. We used recaptures from our site in combination with hunter recoveries to model annual survival, recovery rates, and fidelity to our capture location. Most recoveries (>90%) occurred in the Pacific Flyway with 64% reported from California's Central Valley. Our top candidate models allowed survival to vary by sex but not by age or year. Estimated annual survival was 77.6% (95% CI: 73.9-81.0%) for males and 60.2% (95% CI: 53.2-67.0%) for females. Reporting rates varied by age, sex, and year; estimates for adult males exceeded those for adult females by 3.5 times. Within sexes, reporting rates of hatch-year pintails exceeded those of adults. Estimated recovery rates were considerably lower than those estimated during the 1950s-1970s for winter banded pintails (Hestbeck 1993b), but there were no differences in survival rates. This suggests that changes in harvest regulations may not have influenced annual survival in this population. The propensity of banded pintails to return to our capture site (fidelity rate) varied between sexes and was positively correlated with water conditions in prairie Canada. Our estimates of fidelity rates varied from 77.4% to 87.2% for males and 89.8% to 94.3% for females. Our fidelity estimates suggest that some level of subpopulation structuring may exist for northern pintails. Additionally, our estimates of fidelity support previous observations of northern pintails overflying poor wetland habitat conditions on the Canadian prairies.

  1. Storm-surge flooding on the Yukon-Kuskokwim Delta, Alaska

    Science.gov (United States)

    Terenzi, John; Ely, Craig R.; Jorgenson, M. Torre

    2014-01-01

    Coastal regions of Alaska are regularly affected by intense storms of ocean origin, the frequency and intensity of which are expected to increase as a result of global climate change. The Yukon-Kuskokwim Delta (YKD), situated in western Alaska on the eastern edge of the Bering Sea, is one of the largest deltaic systems in North America. Its low relief makes it especially susceptible to storm-driven flood tides and increases in sea level. Little information exists on the extent of flooding caused by storm surges in western Alaska and its effects on salinization, shoreline erosion, permafrost thaw, vegetation, wildlife, and the subsistence-based economy. In this paper, we summarize storm flooding events in the Bering Sea region of western Alaska during 1913 – 2011 and map both the extent of inland flooding caused by autumn storms on the central YKD, using Radarsat-1 and MODIS satellite imagery, and the drift lines, using high-resolution IKONOS satellite imagery and field surveys. The largest storm surges occurred in autumn and were associated with high tides and strong (> 65 km hr-1) southwest winds. Maximum inland extent of flooding from storm surges was 30.3 km in 2005, 27.4 km in 2006, and 32.3 km in 2011, with total flood area covering 47.1%, 32.5%, and 39.4% of the 6730 km2 study area, respectively. Peak stages for the 2005 and 2011 storms were 3.1 m and 3.3 m above mean sea level, respectively—almost as high as the 3.5 m amsl elevation estimated for the largest storm observed (in November 1974). Several historically abandoned village sites lie within the area of inundation of the largest flood events. With projected sea level rise, large storms are expected to become more frequent and cover larger areas, with deleterious effects on freshwater ponds, non-saline habitats, permafrost, and landscapes used by nesting birds and local people.

  2. 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. © 2011 Blackwell Publishing Ltd.

  3. Alaska/Yukon Geoid Improvement by a Data-Driven Stokes's Kernel Modification Approach

    Science.gov (United States)

    Li, Xiaopeng; Roman, Daniel R.

    2015-04-01

    Geoid modeling over Alaska of USA and Yukon Canada being a trans-national issue faces a great challenge primarily due to the inhomogeneous surface gravity data (Saleh et al, 2013) and the dynamic geology (Freymueller et al, 2008) as well as its complex geological rheology. Previous study (Roman and Li 2014) used updated satellite models (Bruinsma et al 2013) and newly acquired aerogravity data from the GRAV-D project (Smith 2007) to capture the gravity field changes in the targeting areas primarily in the middle-to-long wavelength. In CONUS, the geoid model was largely improved. However, the precision of the resulted geoid model in Alaska was still in the decimeter level, 19cm at the 32 tide bench marks and 24cm on the 202 GPS/Leveling bench marks that gives a total of 23.8cm at all of these calibrated surface control points, where the datum bias was removed. Conventional kernel modification methods in this area (Li and Wang 2011) had limited effects on improving the precision of the geoid models. To compensate the geoid miss fits, a new Stokes's kernel modification method based on a data-driven technique is presented in this study. First, the method was tested on simulated data sets (Fig. 1), where the geoid errors have been reduced by 2 orders of magnitude (Fig 2). For the real data sets, some iteration steps are required to overcome the rank deficiency problem caused by the limited control data that are irregularly distributed in the target area. For instance, after 3 iterations, the standard deviation dropped about 2.7cm (Fig 3). Modification at other critical degrees can further minimize the geoid model miss fits caused either by the gravity error or the remaining datum error in the control points.

  4. Reconstruction of fire history of the Yukon-Kuskokwim Delta, Alaska

    Science.gov (United States)

    Sae-lim, J.; Mann, P. J.; Russell, J. M.; Natali, S.; Vachula, R. S.; Schade, J. D.; Holmes, R. M.

    2017-12-01

    Wildfire is an important disturbance in Arctic ecosystems and can cause abrupt perturbations in global carbon cycling and atmospheric chemistry. Over the next few decades, arctic fire frequency, intensity and extent is projected to increase due to anthropogenic climate change, as regional air temperatures are increasing at more than twice the global average. In order to more accurately predict the anthropogenic impacts of climate change on tundra fire regimes, it is critical to have detailed knowledge of the natural frequency and extent of past wildfires. However, reliable historical records only extend back a few hundred years, whereas climatic shifts have affected fire regimes for thousands of years. In this work we analyzed a lake sediment core collected from the Yukon-Kuskokwim (YK) Delta, Alaska, a region that has recently experienced fire and is predicted to see increasing fire frequency in the near future. Our primary lake site is situated adjacent to recent burned areas, providing a `calibration' point and also attesting to the sensitivity of the sites. We used charcoal counts alongside geochemical measurements (C:N, 13C, 15N, 210Pb, X-ray fluorescence analyses of elemental chemistry) to reconstruct past fire history and ecosystem responses during the late Holocene. Average C (%C) and N concentrations (%N) in the core were 8.10 ±0.74% and 0.48 ±0.05%, resulting in C:N ratios of 16.80 ±0.74. The values are generally stable, with no obvious trend in C, N or C:N with depth; however, fluctuations in sediment composition in other nearby lake sediment cores possibly suggests shifts in lake conditions (oxic, anoxic) over time that might result from paleofires. This study provides a baseline for estimated fire return intervals in the YK Delta that will support more accurate projections of tundra fire frequencies under a changing climate.

  5. The impact of fire on nitrogen availability in the Yukon Kuskokwim Delta, Alaska

    Science.gov (United States)

    Jardine, L.; Natali, S.; Schade, J. D.; Holmes, R. M.; Mann, P. J.; Pena, H., III

    2017-12-01

    Rising temperatures and changing precipitation patterns in the Arctic are increasing the severity and frequency of fires, resulting in direct and indirect changes to permafrost ecosystems. Due to slow rates of decomposition, nitrogen (N) is a highly limiting resource in tundra. The availability of N can be substantially altered following fire as a direct result of combustion of organic matter and also due to long-term changes in ecosystem structure and function. It is critical to understand both the short- (years) and long (decades)-term effects of fire on N availability because of the role of N in arctic ecosystems. In order to better understand the availability of N following fire, we collected active layer and permafrost soil and vegetation samples from unburned, 2015 burn scars, and 1972 burn scars in peat plateau tundra in the Yukon Kuskokwim Delta, Alaska. We measured carbon (C) and nitrogen (N) concentrations and pools in plants and soils, and soil organic matter content, extractable inorganic N and potentially mineralizable N in active layer (0-30 cm) and surface permafrost (to 100 cm). We found that active layer N concentrations were significantly lower in the two-year burn, but N concentrations in the 45-year burn were comparable to that of unburned tundra. The levels of ammonium in the active layer were nearly three times higher in both the two- and in the 45-year-old burns, while extractable nitrate was low (disturbance by fire, there is still a large potential for N assimilation, nitrification, or nitrous oxide production in tundra ecosystems. These findings are especially relevant as fire regimes intensify across the Arctic, which may have long-term consequences for plant and soil communities and ecosystem C and N storage.

  6. Spatial variability of hillslope water balance, wolf creek basin, subarctic yukon

    Science.gov (United States)

    Carey, Sean K.; Woo, Ming-Ko

    2001-11-01

    A hydrological study was conducted between 1997 and 1999 in the subalpine open woodland of the Wolf Creek Basin, Yukon, to assess the interslope water balance variability. The water balance during the snowmelt and summer periods on four hillslopes revealed strong contrasts in process magnitudes and highlighted important factors including frost, vegetation, soils and microclimate that controlled vertical and lateral fluxes of water. Snow accounted for approximately half the annual water input, while differences in accumulation among hillslopes were related to interception properties of vegetation. Available energy at the snow surface controlled the melt sequence and the snow on some slopes disappeared up to two months earlier than others. Snowmelt runoff was confined to slopes with ice-rich substrates that inhibited deep percolation, with the runoff magnitude governed by the snow storage and the antecedent moisture of the desiccated organic soils prior to melt. During summer, evapotranspiration exceeded rainfall, largely sustained by water from the soil moisture reservoir recharged during the melt period. Differences in net radiation on slopes controlled the potential evapotranspiration, with the actual rates limited by the phenology of the deciduous forests and shrubs. Evapotranspiration was further suppressed on slopes where the organic soils became dry in late summer. Summer runoff was confined to slopes with porous organic layers overlying mineral soils to form a two-layer flow system: (1) quickflow in the surface organic layer and (2) slowflow in the mineral soil. Differences in the rates of flow were related to the position of the water table which may rise into the organic layer to activate quickflow. The presence of ice-rich frost and permafrost impeded vertical drainage and indirectly regulated the position of the water table. The location of the hillslope within a basin influenced recharge and discharge dynamics. Slope segments with large inflows sustained

  7. 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.

  8. Palaeomagnetism of lower cretaceous tuffs from Yukon-Kuskokwim delta region, western Alaska

    Science.gov (United States)

    Globerman, B.R.; Coe, R.S.; Hoare, J.M.; Decker, J.

    1983-01-01

    During the past decade, the prescient arguments1-3 for the allochthoneity of large portions of southern Alaska have been corroborated by detailed geological and palaeomagnetic studies in south-central Alaska 4-9 the Alaska Peninsula10, Kodiak Island11,12 and the Prince William Sound area13 (Fig. 1). These investigations have demonstrated sizeable northward displacements for rocks of late Palaeozoic, Mesozoic, and early Tertiary age in those regions, with northward motion at times culminating in collision of the allochthonous terranes against the backstop of 'nuclear' Alaska14,15. A fundamental question is which parts of Alaska underwent significantly less latitudinal translation relative to the 'stable' North American continent, thereby serving as the 'accretionary nucleus' into which the displaced 'microplates'16 were eventually incorporated17,18? Here we present new palaeomagnetic results from tuffs and associated volcaniclastic rocks of early Cretaceous age from the Yukon-Kuskokwin delta region in western Alaska. These rocks were probably overprinted during the Cretaceous long normal polarity interval, although a remagnetization event as recent as Palaeocene cannot be ruled out. This overprint direction is not appreciably discordant from the expected late Cretaceous direction for cratonal North America. The implied absence of appreciable northward displacement for this region is consistent with the general late Mesozoic-early Tertiary tectonic pattern for Alaska, based on more definitive studies: little to no poleward displacement for central Alaska, though substantially more northward drift for the 'southern Alaska terranes' (comprising Alaska Peninsula, Kodiak Island, Prince William Sound area, and Matunuska Valley) since late Cretaceous to Palaeocene time. ?? 1983 Nature Publishing Group.

  9. 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.

  10. 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

  11. Assessing the Global Extent of Rivers Observable by SWOT

    Science.gov (United States)

    Pavelsky, T.; Durand, M. T.; Andreadis, K.; Beighley, E.; Allen, G. H.; Miller, Z.

    2013-12-01

    Flow of water through rivers is among the key fluxes in the global hydrologic cycle and its knowledge would advance the understanding of flood hazards, water resources management, ecology, and climate. However, gauges providing publicly accessible measurements of river stage or discharge remain sparse in many regions. The Surface Water and Ocean Topography (SWOT) satellite mission is a joint project of NASA and the French Centre National d'Etudes Spatiales (CNES) that would provide the first high-resolution images of simultaneous terrestrial water surface height, inundation extent, and ocean surface elevation. Among SWOT's primary goals is the direct observation of variations in river water surface elevation and, where possible, estimation of river discharge from SWOT measurements. The mission science requirements specify that rivers wider than 100 m would be observed globally, with a goal of observing rivers wider than 50m. However, the extent of anticipated SWOT river observations remains fundamentally unknown because no high-resolution, global dataset of river widths exists. Here, we estimate the global extent of rivers wider than 50 m-100 m thresholds using established relationships among river width, discharge, and drainage area. We combine a global digital elevation model with in situ river discharge data to estimate the global extent of SWOT-observable rivers, and validate these estimates against satellite-derived measurements of river width in two large river basins (the Yukon and the Ohio). We then compare the extent of SWOT-observed rivers with the current publicly-available, global gauge network included in the Global Runoff Data Centre (GRDC) database to examine the impact of SWOT on the availability of river observation over continental and global scales. Results suggest that if SWOT observes 100 m wide rivers, river basins with areas greater than 50,000 km2 will commonly be measured. If SWOT could observe 50 m wide rivers, then most 10,000 km2 basins

  12. Geologic implications of topographic, gravity, and aeromagnetic data in the northern Yukon-Koyukuk province and its borderlands, Alaska

    Science.gov (United States)

    Cady, J.W.

    1989-01-01

    The northern Yukon-Koyukuk province is characterized by low elevation and high Bouguer gravity and aeromagnetic anomalies in contrast to the adjacent Brooks Range and Ruby geanticline. Using newly compiled digital topographic, gravity, and aeromagnetic maps, the province is divided into three geophysical domains. The Koyukuk domain, which is nearly equivalent to the Koyukuk lithotectonic terrane, is a horseshoe-shaped area, open to the south, of low topography, high gravity, and high-amplitude magnetic anomalies caused by an intraoceanic magmatic arc. The Angayucham and Kanuti domains are geophysical subdivisions of the Angayucham lithotectonic terrane that occur along the northern and southeastern margins of the Yukon-Koyukuk province, where oceanic rocks have been thrust over continental rocks of the Brooks Range and Ruby geanticline. The modeling supports, but does not prove, the hypothesis that the crust of the Kobuk-Koyukuk basin is 32-35 km thick, consisting of a tectonically thickened section of Cretaceous volcanic and sedimentary rocks and older oceanic crust. -from Author

  13. 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.

  14. Re-emergence of hereditary polyneuropathy in scandinavian alaskan malamute dogs-old enemy or new entity? A case series

    DEFF Research Database (Denmark)

    Jäderlund, Karin Hultin; Rohdin, Cecilia; Berendt, Mette

    2017-01-01

    A homozygous mutation has been identified in the N-myc downstream-regulated gene 1 (NDRG1) in recent cases of polyneuropathy in Alaskan malamute dogs from the Nordic countries and USA. The objective of the present study was to determine if cases diagnosed 30-40 years ago with polyneuropathy...... in the Alaskan malamute breed in Norway had the same hereditary disease as the recent cases. Fourteen historical cases and 12 recently diagnosed Alaskan malamute dogs with hereditary polyneuropathy, and their parents and littermates (n = 88) were included in this study (total n = 114). After phenotyping...... of historical and recent cases, NDRG1 genotyping was performed using DNA extracted from archived material from five Norwegian dogs affected by the disease in the late 1970s and 1980s. In addition, pedigrees were analysed. Our study concluded that historical and recent phenotypic polyneuropathy cases were...

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

    Directory of Open Access Journals (Sweden)

    Christopher Ryan Penton

    2016-11-01

    Full Text Available 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 were clustered at 5% amino acid dissimilarity resulting in 1,631 OTUs. Sample depth in relation to water table depth was correlated to differences in the NifH sequence classes. NifH sequences most closely related to group I nifH-harboring Alpha- and Beta Proteobacteria were in higher abundance above water table depth while those related to group III nifH-harboring Delta and Gamma Proteobacteria were more abundant below. The most dominant below water table depth NifH sequences, comprising 1/3 of the total, were distantly related to Verrucomicrobia-Opitutaceae. Overall, these results suggest that permafrost thaw alters the class-level composition of N2-fixing communities in the thawed soil layers and that this distinction corresponds to the depth of the water table. These nifH data were also compared to nifH sequences obtained from a study at an Alaskan taiga site, and to those of other geographically distant, non-permafrost sites. The two Alaska sites were differentiated largely by changes in relative abundances of the same OTUs, whereas the non-Alaska sites were differentiated by the lack of many Alaskan OTUs, and the presence of unique halophilic, sulfate- and iron-reducing taxa in the Alaska sites.

  16. Levoglucosan Levels in Alaskan Ice Cores as a Record of Past Wildfires

    Science.gov (United States)

    Dunham, M. E.; Osterberg, E. C.; Kehrwald, N. M.; Kennedy, J.; Ferris, D. G.

    2017-12-01

    Glaciers in southeast Alaska are significant contributors to global sea-level rise, and therefore understanding the mechanisms driving their recent mass loss is crucial for predicting future sea-level change. Fire activity in Alaska has increased dramatically during the last decade, adding a potential new source of light-absorbing organic material (soot) to the Juneau Icefield that can reduce albedo and enhance surface melt rates. The goal of this project is to create an accurate record of Alaskan wildfires to understand how Alaskan glacial mass balance is affected by the deposition of organic aerosols from wildfires. Previously, oxalate, ammonia, and potassium ion levels have been used as proxies for past wildfire activity, but these ions all have broader emission sources in addition to wildfires. Here we develop a record of past Alaskan fire events and climate from: (1) levels of a biomass burning indicator, levoglucosan, which only forms when cellulose is burned over 300 °C, (2) major ions including oxalate, ammonia, and potassium; (3) the number and size distribution of particles to quantify trace amounts of soot from wildfires; and (4) stable water isotope ratios as a proxy for past temperature in ice cores. We utilize a total of four shallow ice cores, ranging from 7 to 9 m in length, that were collected by a biogeochemistry team during the Juneau Icefield Research Program (JIRP) in 2016. Complications include our limited understanding of the conservation and degradation of levoglucosan over time or during the firnification process. We hypothesize that particle counts will be correlated with levoglucosan peaks, co-varying with wildfire frequency and temperatures over time. Based on previous work, we also expect to find correlations between levoglucosan and oxalate ion concentrations, even though oxalate ions have sources in addition to wildfire activity.

  17. Anti-infective Discorhabdins from a Deep-Water Alaskan Sponge of the Genus Latrunculia†

    Science.gov (United States)

    Na, MinKyun; Ding, Yuanqing; Wang, Bin; Tekwani, Babu L.; Schinazi, Raymond F.; Franzblau, Scott; Kelly, Michelle; Stone, Robert; Li, Xing-Cong; Ferreira, Daneel; Hamann, Mark T.

    2016-01-01

    Bioassay- and LC-MS-guided fractionation of a methanol extract from a new deep-water Alaskan sponge species of the genus Latrunculia resulted in the isolation of two new brominated pyrroloiminoquinones, dihydrodiscorhabdin B (1) and discorhabdin Y (2), along with six known pyrroloiminoquinone alkaloids, discorhabdins A (3), C (4), E (5), and L (6), dihydrodiscorhabdin C (7), and the benzene derivative 8. Compounds 3, 4, and 7 exhibited anti-HCV activity, antimalarial activity, and selective antimicrobial activity. Although compounds 3 and 7 displayed potent and selective in vitro antiprotozoal activity, Plasmodium berghei-infected mice did not respond to these metabolites due to their toxicity in vivo. PMID:20337497

  18. Anti-infective discorhabdins from a deep-water alaskan sponge of the genus Latrunculia.

    Science.gov (United States)

    Na, Minkyun; Ding, Yuanqing; Wang, Bin; Tekwani, Babu L; Schinazi, Raymond F; Franzblau, Scott; Kelly, Michelle; Stone, Robert; Li, Xing-Cong; Ferreira, Daneel; Hamann, Mark T

    2010-03-26

    Bioassay- and LC-MS-guided fractionation of a methanol extract from a new deep-water Alaskan sponge species of the genus Latrunculia resulted in the isolation of two new brominated pyrroloiminoquinones, dihydrodiscorhabdin B and discorhabdin Y (2), along with six known pyrroloiminoquinone alkaloids, discorhabdins A (3), C (4), E (5), and L (6), dihydrodiscorhabdin C (7), and the benzene derivative 8. Compounds 3, 4, and 7 exhibited anti-HCV activity, antimalarial activity, and selective antimicrobial activity. Although compounds 3 and 7 displayed potent and selective in vitro antiprotozoal activity, Plasmodium berghei-infected mice did not respond to these metabolites due to their toxicity in vivo.

  19. 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

  20. 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.

  1. Mineralogical and Geochemical Study of Titanite Associated With Copper Mineralization in the Hopper Property, Yukon Territory, Canada

    Science.gov (United States)

    Blumenthal, V. H.; Linnen, R. L.

    2009-05-01

    Copper mineralization in central Yukon is well known, but the metallogeny of the Ruby Range batholith, west of the copper belt, is poorly understood. The Hopper property, situated in the south western part of the Yukon in the Yukon-Tanana terrane, contains copper mineralization hosted by granodiorite and quartz feldspar porphyry of cal-alkaline affinity. These rock units, interpreted to be part of the Ruby Range batholith, intruded metasediments of the Ashihik Metamorphic Suite rocks. Mafic dykes cross cut the intrusion followed by aplite dykes. Small occurrences of skarn also occur in the area and some of these contain copper mineralization. The copper mineralization at the Hopper property appears to have a porphyry-type affinity. However, it is associated with a shear zone and propylitic alteration unlike other typical copper porphyry-type deposits. This raises the question whether or not the mineralization is orthomagmatic in origin, i.e., whether or not this is a true porphyry system. The main zone of mineralization is 1 kilometer long and 0.5 kilometer wide. It is characterized by disseminated chalcopyrite and pyrite, which also occur along fractures. Molybdenite mineralization was found to be associated with slickensides. Alteration minerals associated with the copper mineralization are chlorite, epidote-clinozoisite, carbonate and titanite. Chlorite and epidote-clinozoisite are concentrated in the mineralized zone, whereas an earlier potassic alteration shows a weaker spatial correlation with the mineralization. The association of the mineralization with propylitic alteration leads us to believe the mineralization is shear related, although a deeper porphyritic system may be present at depth. Two populations of titanite at the Hopper property are recognized based on their shape, size and association with other minerals. The first population, defined by a length of 100 micrometers to 1 centimeter, euhedral boundaries, and planar contacts with other magmatic

  2. 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

    2016-01-01

    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.

  3. Establishing an Alaskan birch syrup industry: Birch Syrup—It’s the Un-maple!TM

    Science.gov (United States)

    Marlene. Cameron

    2001-01-01

    Ten years ago a small group of Alaskans began commercial production of birch syrup from the sap of the paper birch, Betula papyrifera, and established an industry that is expanding in response to demand and has the potential to make a significant contribution to Alaska's economy. There are still many problems to be solved; research and...

  4. The role of windstorm exposure and yellow cedar decline on landslide susceptibility in southeast Alaskan temperate rainforests

    Science.gov (United States)

    Brian Buma; Adelaide C. Johnson

    2015-01-01

    Interactions between ecological disturbances have the potential to alter other disturbances and their associated regimes, such as the likelihood, severity, and extent of events. The influence of exposure to wind and yellow cedar decline on the landslide regime of Alaskan temperate rainforests was explored using presence-only modeling techniques. The wind regime was...

  5. Urban American Indian/Alaskan Natives Compared to Non-Indians in Out-of-Home Care

    Science.gov (United States)

    Carter, Vernon B.

    2011-01-01

    Historically, American Indian/Alaskan Native (AI/AN) children have been disproportionately represented in the foster care system. In this study, nationally representative child welfare data from October 1999 was used to compare urban AI/AN children to non-Indian children placed into out-of-home care. Compared to non-Indian children, urban AI/AN…

  6. Long-Term Effects of Otitis Media a Ten-Year Cohort Study of Alaskan Eskimo Children

    Science.gov (United States)

    Kaplan, Gary J.; And Others

    1973-01-01

    Histories of ear disease, otoscopic examinations, and audiologic, intelligence, and achievement tests were obtained from a cohort of 489 Alaskan Eskimo children, followed through the first 10 years of life, to determine whether otitis media (middle ear inflammation) deleteriously affected intellectual functioning and achievement in school.…

  7. Migratory Patterns of Chinook Salmon Oncorhynchus tshawytscha Returning to a Large, Free-flowing River Basin

    Science.gov (United States)

    Eiler, John H.; Evans, Allison N.; Schreck, Carl B.

    2015-01-01

    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

  8. Biodiversity and springtime patterns of egg production and development for parasites of the Chisana Caribou herd, Yukon Territory, Canada

    Directory of Open Access Journals (Sweden)

    Bryanne Hoar

    2009-12-01

    Full Text Available We investigated the biodiversity and springtime patterns of parasite egg/oocyst and larval production from feces and parasite development in the environment for the Chisana caribou herd in the southwest Yukon Territory, Canada from 29 March to 14 June 2006. Fecal samples from 50 adult cows that were housed in a temporary enclosure within the herd’s natural range at Boundary Lake, Yukon Territory were collected and analyzed during 5 sampling periods. A minimum of 6 parasite genera were recovered: eggs of Trichostrongylidae species (most likely Ostertagia gruehneri and Teladorsagia boreoarcticus, Marshallagia sp., Anoplocephalidae cestodes, and Skrjabinema sp.; oocysts of Eimeria spp.; and dorsal-spined first-stage protostrongylid larvae, including Parelaphostrongylus andersoni. Prevalence of Trichostrongylidae spp. eggs in fresh fecals was at or near 100% throughout the sampling period, however, the median intensity increased significantly from 8 to 34 eggs per gram (epg at the peak of calving and then decreased to 12 epg 2 weeks post-calving (P = 2.83e-07. Three plots of feces collected from these animals were established outside of the enclosure on 4 May 2006 and monitored every 10 days to investigate patterns of parasite development under natural conditions. The total number of Trichostrongylidae spp. (eggs + larvae in fecal plots did not change over time, but as the number of larvae increased, egg counts decreased. The presence of other parasite species in the fecal plots remained constant over time. This study is the first to document the parasite diversity for the Chisana caribou herd and to exam¬ine the development and survival of eggs and larvae in feces throughout the spring and early summer. Abstract in Norwegian / Sammendrag: Parasitters artssammensetning og forløp av eggproduksjon og parasittutvikling om våren hos Chisanavillreinen i Yukon, Canada I en periode fra 29. mars til 14. juni 2006 tok vi prøver fra reinmøkk og under

  9. Climatically induced floristic changes across the Eocene-Oligocene transition in the northern high latitudes, Yukon Territory, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Ridgway, K.D.; Sweet, A.R.; Cameron, A.R. [Purdue University, West Lafayette, IN (United States). Dept. of Earth and Atmospheric Sciences

    1995-06-01

    Global temperature decline associated with the Eocene-Oligocene transition resulted in extinctions of plants and animals in both marine and nonmarine environments. The extensive stratigraphic exposures, well-preserved palynological assemblages, and interbedded coal seams of the nonmarine Amphitheatre Formation, Burwash Basin, Yukon Territory, provide a comprehensive record of this transition. The formation spans a paleoclimatically significant interval otherwise poorly represented in high-latitude deposits of the northwestern Cordiller. Palynological data constrained by the chronologic and stratigraphic framework established for the Amphitheatre Formation indicate that the global temperature decline resulted in a shift from warm temperate, angiosperm-dominated to cooler temperate, gymnosperm-dominated (mainly coniferous) forest types. Petrographic compositional changes in the coals document the same plant community changes. The floristic data also indicate that, at high latitudes, there may have been a change to a wetter and less seasonal climate during the overall global cooling trend.

  10. 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.

  11. Palaeohydrology of the Southwest Yukon Territory, Canada, based on multiproxy analyses of lake sediment cores from a depth transect

    Science.gov (United States)

    Anderson, L.; Abbott, M.B.; Finney, B.P.; Edwards, M.E.

    2005-01-01

    Lake-level variations at Marcella Lake, a small, hydrologically closed lake in the southwestern Yukon Territory, document changes in effective moisture since the early Holocene. Former water levels, driven by regional palaeohydrology, were reconstructed by multiproxy analyses of sediment cores from four sites spanning shallow to deep water. Marcella Lake today is thermally stratified, being protected from wind by its position in a depression. It is alkaline and undergoes bio-induced calcification. Relative accumulations of calcium carbonate and organic matter at the sediment-water interface depend on the location of the depositional site relative to the thermocline. We relate lake-level fluctuations to down-core stratigraphic variations in composition, geochemistry, sedimentary structures and to the occurrence of unconformities in four cores based on observations of modern limnology and sedimentation processes. Twenty-four AMS radiocarbon dates on macrofossils and pollen provide the lake-level chronology. Prior to 10 000 cal. BP water levels were low, but then they rose to 3 to 4 m below modern levels. Between 7500 and 5000 cal. BP water levels were 5 to 6 m below modern but rose by 4000 cal. BP. Between 4000 and 2000 cal. BP they were higher than modern. During the last 2000 years, water levels were either near or 1 to 2 m below modern levels. Marcella Lake water-level fluctuations correspond with previously documented palaeoenvironmental and palaeoclimatic changes and provide new, independent effective moisture information. The improved geochronology and quantitative water-level estimates are a framework for more detailed studies in the southwest Yukon. ?? 2005 Edward Arnold (Publishers) Ltd.

  12. The Missing Link: the Role of Floodplain Tie Channels in Connecting Off River Water Bodies to Lowland Rivers

    Science.gov (United States)

    Rowland, J. C.; Dietrich, W. E.; Day, G.

    2005-05-01

    Along lowland river systems across the globe the exchange of water, sediment, carbon, nutrients and biota between main stem rivers and off-river water bodies (ORWB) is facilitated by the presence of stable secondary channels referred to here as tie channels. Sixty five percent of the ORWB along the middle Fly River in Papua New Guinea connect to the river through such channels. A similar percentage of the 37 ORWB located between Baton Rouge and Memphis on the lower Mississippi River at one time were linked to the river by tie or batture (as they are locally known) channels. Levee construction and other alterations aimed at flood control or navigation on the Mississippi have left only a handful of lakes connected to the river, of these, most are heavily altered by dredging or other modifications. Tie channels were also once common along major tributaries to the Mississippi, such as the Red River. In the much less disturbed Alaskan environment, tie channels are still common, especially along Birch Creek and the Koyukuk and Black rivers. Our studies on the Mississippi River, in Alaska and in Papua New Guinea indicate that tie channels possess a common channel form that is stable and self-maintaining for hundreds to possibly a thousand years. Tie channels exhibit narrow width to depth ratios (~ 5.5) and consistently scale in cross-sectional dimensions to the size of the lake into which they flow. Variations in river and lake stage drive flow bi-directionally through tie channels. A local high or sill in the bed of tie channels controls the degree and duration of connection between the river and ORWB, with many lakes becoming isolated during periods of low stage. The life-span of a tie channel depends on the rate of sediment loading to the ORWB. Our research indicates that this rate directly corresponds to the sediment loading in the main stem river. Along the Fly River, for example, a 5 to 7 fold increase in the river sediment load has resulted increases of 6 to 17

  13. 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.

  14. Seismic array processing and computational infrastructure for improved monitoring of Alaskan and Aleutian seismicity and volcanoes

    Science.gov (United States)

    Lindquist, Kent Gordon

    We constructed a near-real-time system, called Iceworm, to automate seismic data collection, processing, storage, and distribution at the Alaska Earthquake Information Center (AEIC). Phase-picking, phase association, and interprocess communication components come from Earthworm (U.S. Geological Survey). A new generic, internal format for digital data supports unified handling of data from diverse sources. A new infrastructure for applying processing algorithms to near-real-time data streams supports automated information extraction from seismic wavefields. Integration of Datascope (U. of Colorado) provides relational database management of all automated measurements, parametric information for located hypocenters, and waveform data from Iceworm. Data from 1997 yield 329 earthquakes located by both Iceworm and the AEIC. Of these, 203 have location residuals under 22 km, sufficient for hazard response. Regionalized inversions for local magnitude in Alaska yield Msb{L} calibration curves (logAsb0) that differ from the Californian Richter magnitude. The new curve is 0.2\\ Msb{L} units more attenuative than the Californian curve at 400 km for earthquakes north of the Denali fault. South of the fault, and for a region north of Cook Inlet, the difference is 0.4\\ Msb{L}. A curve for deep events differs by 0.6\\ Msb{L} at 650 km. We expand geographic coverage of Alaskan regional seismic monitoring to the Aleutians, the Bering Sea, and the entire Arctic by initiating the processing of four short-period, Alaskan seismic arrays. To show the array stations' sensitivity, we detect and locate two microearthquakes that were missed by the AEIC. An empirical study of the location sensitivity of the arrays predicts improvements over the Alaskan regional network that are shown as map-view contour plots. We verify these predictions by detecting an Msb{L} 3.2 event near Unimak Island with one array. The detection and location of four representative earthquakes illustrates the expansion

  15. Mid- to Late Holocene environmental dynamics on the Yukon Coastal Plain and Herschel Island (Canada) – evidence from polygonal peatlands and lake sediment

    OpenAIRE

    Wolter, Juliane

    2017-01-01

    The North American Arctic witnessed high-amplitude climatic change during the Early Holocene that resulted in regional-scale environmental change. These changes are well documented in the literature. The environmental impacts of moderate climatic oscillations during the Mid- to Late Holocene are less well understood, especially on the Yukon Coastal Plain, which is geographically and topographically isolated from the rest of the western Canadian Arctic. The region is currently experiencing inc...

  16. Incidence of adverse cardiac events 5 years after polymer-free sirolimus eluting stent implantation: Results from the prospective Bad Berka Yukon Choice™ registry.

    Science.gov (United States)

    Ohlow, Marc-Alexander; von Korn, Hubertus; Gunkel, Oliver; Farah, Ahmed; Fuhrmann, Joerg T; Lauer, Bernward

    2014-12-01

    Drug-eluting stents (DES) constitute a major achievement in preventing re-stenosis, concerns remain regarding the increased inflammatory responses associated with the polymers used. This analysis focuses on outcomes in patients receiving the polymer-free sirolimus-eluting stent system YUKON-Choice (Yukon-DES, Translumina, Germany). From 01/2006-09/2008 all patients receiving Yukon-DES (≥2.5 mm diameter) were prospectively enrolled in our registry. The primary endpoint was long-term major adverse cardiac events (MACE). 701 patients were included in our registry. Mean age was 65.7 ± 10 years (73% male gender, 35.5% diabetes, and 32.2% acute coronary syndrome). 76% of the lesions were of Type B2/C. Lesion length was 24.6 ± 5.2 mm and mean stent diameter was 2.8 ± 0.4 mm. A total of 511 pts (72%) underwent 6-months angiographic follow-up, target vessel revascularization was noted in 23.5%. At 5 years clinical outcomes were: cardiac death 5.8%; myocardial infarction 3.4%; and TVR 24.6%. The incidence of MACE differed significantly between "on-label" and "off-label" indications (14.8% vs. 40.8% MACE; P 1 year) ST occurred in 0.29%. Our data suggests that the implantation of the sirolimus-coated polymer-free YUKON-DES is safe and feasible with a very low incidence of ST in this real world patient cohort with high percentage of diabetes and small vessels. © 2013 Wiley Periodicals, Inc.

  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. 33 CFR 334.1280 - Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force. 334.1280 Section 334.1280 Navigation and Navigable... REGULATIONS § 334.1280 Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force. (a...

  19. 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.

  20. Drought effects on large fire activity in Canadian and Alaskan forests

    International Nuclear Information System (INIS)

    Xiao Jingfeng; Zhuang Qianlai

    2007-01-01

    Fire is the dominant disturbance in forest ecosystems across Canada and Alaska, and has important implications for forest ecosystems, terrestrial carbon dioxide emissions and the forestry industry. Large fire activity had increased in Canadian and Alaskan forests during the last four decades of the 20th century. Here we combined the Palmer Drought Severity Index and historical large fire databases to demonstrate that Canada and Alaska forest regions experienced summer drying over this time period, and drought during the fire season significantly affected forest fire activity in these regions. Climatic warming, positive geopotential height anomalies and ocean circulation patterns were spatially and temporally convolved in causing drought conditions, which in turn enhanced fuel flammability and thereby indirectly affected fire activity. Future fire regimes will likely depend on drought patterns under global climate change scenarios

  1. The opportunities and challenges of living off-grid on renewable energy in the Yukon : results of a baseline study and integrated design charrette

    International Nuclear Information System (INIS)

    Ayoub, J.

    2004-01-01

    There are over 200,000 Canadians living in more than 300 remote communities throughout Canada. Energy supply to these communities is characterized by high costs, high degree of dependence on imported fuel, a lack of local technical expertise to provide needed services, and a reliance on diesel generators for producing electricity. Costs can vary from $0.15 to $1.50 per kWh. Renewable energy technologies can be cost effective for electricity generation and for heating applications. A 4-year research and development project entitled: An Integrated Approach to Increasing the Use of Renewable Energy in Off-grid Residences in the North was developed with the aim of increasing the ratio of renewable energy to total energy use in off-grid residences by 10 per cent. The first part of the project established baseline information on renewable energy use in off-grid residences North of the 60 degree north latitude in the Yukon Territory. The Yukon Energy Solutions Centre (YESC), located in Whitehorse, was approached to participate. A survey questionnaire identifying the needs and preferences of residents in 30 off-grid dwellings in the Yukon was developed. Potential participants for renewable energy and energy efficiency audits were identified and home owners' preferences were considered along with the possibility of implementing retrofits. The design charrette was the second activity. This paper presents the results of the baseline study and the design charette and examine the path forward to advance the use of renewable energy technologies in this application sector

  2. Lithospheric Structure across the Alaskan Cordillera from Surface Waves and Receiver Functions

    Science.gov (United States)

    Ward, K. M.; Lin, F. C.

    2017-12-01

    The long awaited Transportable Array (TA) deployment in Alaska and western Canada is nearing its final deployment stage. With only one more deployment season, most of the TA station locations have been occupied and begun providing data. These TA stations combined with upgraded existing locations have provided enough high-quality data to begin investigating the crustal and upper mantle structure across the entire Alaskan Cordillera. From a tectonic standpoint, many interesting questions remain unanswered. For example, how does the transition from oceanic-oceanic subduction to continental-oceanic normal subduction to continental-oceanic "flat-slab" subduction to strike-slip conservative plate motion affect the deformation/uplift of the overriding plate and mantle geodynamic characteristics? How does the long and completed terrene accretion process partition stress/strain in the crust? On more local scales, are there any significant mid-crustal magmatic systems as observed in other sections of the American Cordillera, and if so, what is there role in uplift and crustal deformation? Our approach to investigating these questions is though surface wave imaging from ambient noise and earthquake generated sources along with Rayleigh wave ellipticity paired with Ps receiver functions. Our preliminary tomography results agree with previous studies but expand the spatial coverage showing additional detail. Our ellipticity results show a heterogeneous but spatially consistent anisotropic shallow crust. Although the complete TA data set has not yet been collected, we have jointly inverted surface waves with receiver functions for a 3-D shear-wave velocity model across the entire Alaskan Cordillera. Key features of our velocity model include a high-velocity feature in the upper mantle associated with the subducting Pacific plate that extends north of the seismicity used to contour the geometry of the slab and mid-crustal low-velocity zones associated with the active volcanics in

  3. Recent increased warming of the Alaskan marine Arctic due to midlatitude linkages

    Science.gov (United States)

    Overland, James E.; Wang, Muyin; Ballinger, Thomas J.

    2018-01-01

    Alaskan Arctic waters have participated in hemispheric-wide Arctic warming over the last two decades at over two times the rate of global warming. During 2008-13, this relative warming occurred only north of the Bering Strait and the atmospheric Arctic front that forms a north-south thermal barrier. This front separates the southeastern Bering Sea temperatures from Arctic air masses. Model projections show that future temperatures in the Chukchi and Beaufort seas continue to warm at a rate greater than the global rate, reaching a change of +4°C by 2040 relative to the 1981-2010 mean. Offshore at 74°N, climate models project the open water duration season to increase from a current average of three months to five months by 2040. These rates are occasionally enhanced by midlatitude connections. Beginning in August 2014, additional Arctic warming was initiated due to increased SST anomalies in the North Pacific and associated shifts to southerly winds over Alaska, especially in winter 2015-16. While global warming and equatorial teleconnections are implicated in North Pacific SSTs, the ending of the 2014-16 North Pacific warm event demonstrates the importance of internal, chaotic atmospheric natural variability on weather conditions in any given year. Impacts from global warming on Alaskan Arctic temperature increases and sea-ice and snow loss, with occasional North Pacific support, are projected to continue to propagate through the marine ecosystem in the foreseeable future. The ecological and societal consequences of such changes show a radical departure from the current Arctic environment.

  4. 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

  5. Charles River

    Science.gov (United States)

    Information on the efforts of the US EPA, the Commonwealth of Massachusetts, the municipalities within the Charles River Watershed and nongovernmental organizations to improve the water quality of the Charles River.

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

    Science.gov (United States)

    Guevara, David R; Champigny, Marc J; Tattersall, Ashley; Dedrick, Jeff; Wong, Chui E; Li, Yong; Labbe, Aurelie; Ping, Chien-Lu; Wang, Yanxiang; Nuin, Paulo; Golding, G Brian; McCarry, Brian E; Summers, Peter S; Moffatt, Barbara A; Weretilnyk, Elizabeth A

    2012-10-01

    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. 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 media suggests that Thellungiella shows

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

    Science.gov (United States)

    2012-01-01

    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 media suggests that

  9. 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

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

    OpenAIRE

    Syed H. Imam; Bor-Sen Chiou; Delilah Woods; Justin Shey; Gregory M. Glenn; William J. Orts; Rajnesh Narayan; Robert J. Avena-Bustillos; Tara H. McHugh; Alberto Pantoja; Peter J. Bechtel

    2008-01-01

    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 highe...

  11. 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

    treatment for North American taxa is that for the new Flora of North America bryophyte volumes, by McQueen and Andrus (2007). In Alaska, a...Note: Nomenclature used in this document follows that in current use in the Flora of North America : Mosses and the TROPICOS Moss nomenclatural...in Moss Flora of North America ) includes 20 species with two varieties in the Alaskan flora. Of these, 14 are described as occurring occasionally

  12. 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.

  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. Dental therapists linked to improved dental outcomes for Alaska Native communities in the Yukon-Kuskokwim Delta.

    Science.gov (United States)

    Chi, Donald L; Lenaker, Dane; Mancl, Lloyd; Dunbar, Matthew; Babb, Michael

    2018-01-29

    Dental Health Aide Therapists (DHATs) have been part of the dental workforce in Alaska's Yukon-Kuskokwim (YK) Delta since 2006. They are trained to provide preventive and restorative care such as filling and extractions. In this study, we evaluated community-level dental outcomes associated with DHATs. This was a secondary data analysis of Alaska Medicaid and electronic health record data for individuals in Alaska's YK Delta (2006-2015). The independent variable was the number of DHAT treatment days in each community. Child outcomes were preventive care, extractions, and general anesthesia. Adult outcomes were preventive care and extractions. We estimated Spearman partial correlation coefficients to test our hypotheses that increased DHAT treatment days would be associated with larger proportions utilizing preventive care and smaller proportions receiving extractions at the community-level. DHAT treatment days were positively associated with preventive care utilization and negatively associated with extractions for children and adults (P justice. © 2018 American Association of Public Health Dentistry.

  15. Long-wave Irradiance Measurement and Modeling during Snowmelt, a Case Study in the Yukon Territory, Canada

    Science.gov (United States)

    Sicart, J.; Essery, R.; Pomeroy, J.

    2004-12-01

    At high latitudes, long-wave radiation emitted by the atmosphere and solar radiation can provide similar amounts of energy for snowmelt due to the low solar elevation and the high albedo of snow. This paper investigates temporal and spatial variations of long-wave irradiance at the snow surface in an open sub-Arctic environment. Measurements were conducted in the Wolf Creek Research Basin, Yukon Territory, Canada (60°36'N, 134°57'W) during the springs of 2002, 2003 and 2004. The main causes of temporal variability are air temperature and cloud cover, especially in the beginning of the melting period when the atmosphere is still cold. Spatial variability was investigated through a sensitivity study to sky view factors and to temperatures of surrounding terrain. The formula of Brutsaert gives a useful estimation of the clear-sky irradiance at hourly time steps. Emission by clouds was parameterized at the daily time scale from the atmospheric attenuation of solar radiation. The inclusion of air temperature variability does not much improve the calculation of cloud emission.

  16. 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.

  17. The gas century: worldwide LNG developments may deal death blow to Alaskan pipeline dream

    International Nuclear Information System (INIS)

    Lorenz, A.

    2004-01-01

    The growing interest in liquefied natural gas (LNG), which casts doubt on the viability of the Alaska gas pipeline, and the potential impacts on Canadian gas exports to the United States are discussed. There is currently a proposal before Congress for an Alaskan LNG project, and consensus appears to be building among American energy experts and law-makers that building a multitude of LNG facilities would be more flexible and cheaper than building the proposed Alaska pipeline. As further proof of the growing popularity of LNG, U.S. industry lobbyists are said to be rapidly gaining congressional support for the idea of building eight to ten billion cubic feet per day of LNG capacity along the U. S. coast. Either development, -- LNG facilities or the Alaska pipeline -- have the potential to seriously impact Canadian natural gas exports. If the Alaska pipeline is built, the addition of five billion cubic feet per day of new gas on the market would cause gas prices to fall; if the U.S. decides to subsidize its gas industry, Canadian gas would be put at a serious disadvantage. Conversely, if the Alaskan LNG proposal were to succeed, the potential demise of the Alaska pipeline would mean the loss of about 12,000 jobs that would be created during the Canadian construction phase of the pipeline, as well as the loss of tariffs. Industry experts predict that by 2005 LNG terminals will dot the periphery of the U. S. coast line; to prepare for these eventualities, Canadian companies, such as Irving Oil, TransCanada Pipelines and EnCana are taking note, and are scrambling not to be left out of the game. As proof of the seriousness of their concern, Irving Oil is adding a Can$500 million LNG facility to its Canaport terminal on the Scotian shelf; TCPL is working to supply an LNG terminal offshore Massachusetts, and EnCana is refurbishing a Louisiana salt cavern to prepare for storage of gas delivered to the Gulf Coast

  18. 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

  19. On the Frontline: Tracking Ocean Acidification in an Alaskan Shellfish Hatchery

    Science.gov (United States)

    Evans, Wiley; Mathis, Jeremy T.; Ramsay, Jacqueline; Hetrick, Jeff

    2015-01-01

    The invasion of anthropogenic carbon dioxide (CO2) into the ocean is shifting the marine carbonate system such that saturation states of calcium carbonate (CaCO3) minerals are decreasing, and this is having a detrimental impact on early life stages of select shellfish species. The global, secular decrease in CaCO3 saturation states is occurring on top of a backdrop of large natural variability in coastal settings; progressively shifting the envelope of variability and leading to longer and more frequent exposure to adverse conditions. This is a great concern in the State of Alaska, a high-latitude setting vulnerable to rapid changes in the marine carbonate system, where an emerging shellfish industry plans major growth over the coming decades. Currently, the Alutiiq Pride Shellfish Hatchery (APSH) in Seward, Alaska is the only hatchery in the state, and produces many shellfish species with early life stages known to be sensitive to low CaCO3 saturation states. Here we present the first land-based OA measurements made in an Alaskan shellfish hatchery, and detail the trends in the saturation state of aragonite (Ωarag), the more soluble form of CaCO3, over a 10-month period in the APSH seawater supply. These data indicate the largest changes are on the seasonal time scale, with extended periods of sub-optimal Ωarag levels (Ωarag < 1.5) in winter and autumn associated with elevated water column respiration and short-lived runoff events, respectively. The data pinpoint a 5-month window of reprieve with favorable Ωarag conditions above the sub-optimal Ωarag threshold, which under predicted upper-bound CO2 emissions trajectories is estimated to close by 2040. To date, many species in production at APSH remain untested in their response to OA, and the data presented here establish the current conditions at APSH as well as provide a framework for hatchery-based measurements in Alaska. The current and expected conditions seen at APSH are essential to consider for this

  20. Quantifying Fire Impact on Alaskan Tundra from Satellite Observations and Field Measurements

    Science.gov (United States)

    Loboda, T. V.; Chen, D.; He, J.; Jenkins, L. K.

    2017-12-01

    Wildfire is a major disturbance agent in Alaskan tundra. The frequency and extent of fire events obtained from paleo, management, and satellite records may yet underestimate the scope of tundra fire impact. Field measurements, collected within the NASA's ABoVE campaign, revealed unexpectedly shallow organic soils ( 15 cm) across all sampled sites of the Noatak valley with no significant difference between recently burned and unburned sites. In typical small and medium-sized tundra burns vegetation recovers rapidly and scars are not discernable in 30 m optical satellite imagery by the end of the first post-fire season. However, field observations indicate that vegetation and subsurface characteristics within fire scars of different ages vary across the landscape. In this study we develop linkages between fire-induced changes to tundra and satellite-based observations from optical, thermal, and microwave imagers to enable extrapolation of in-situ observations to cover the full extent of Alaskan tundra. Our results show that recent ( 30 years) fire history can be reconstructed from optical observations (R2 0.65, pfire history can be determined for 4 years post fire primarily due to increased soil moisture at burned sites. Field measurements suggest that the relatively quick SAR signal dissipation results from more even distribution of surface moisture through the soil column with increases in Active Layer Thickness (ALT). Similar to previous long-term field studies we find an increase in shrub fraction and shrub height within burns over time at the landscape scale; however, the strength and significance of the relationship between shrub fraction and time since fire is governed by burn severity with more severe burns predictably (p post-fire shrub cover. Although reasonably well-correlated to each other when adjusted for topography (R2 0.35, p < 0.001), neither ALT nor soil temperature can be directly linked to optical or thermal brightness observations with acceptable

  1. Distribution of hydrocarbon-utilizing microorganisms and hydrocarbon biodegradation potentials in Alaskan continental shelf areas

    International Nuclear Information System (INIS)

    Roubal, G.; Atlas, R.M.

    1978-01-01

    Hydrocarbon-utilizing microogranisms were enumerated from Alaskan continental shelf areas by using plate counts and a new most-probable-number procedure based on mineralization of 14 C-labeled hydrocarbons. Hydrocarbon utilizers were ubiquitously distributed, with no significant overall concentration differences between sampling regions or between surface water and sediment samples. There were, however, significant seasonal differences in numbers of hydrocarbon utilizers. Distribution of hydrocarbon utilizers within Cook Inlet was positively correlated with occurrence of hydrocarbons in the environment. Hydrocarbon biodegradation potentials were measured by using 14 C-radiolabeled hydrocarbon-spiked crude oil. There was no significant correlation between numbers of hydrocarbon utilizers and hydrocarbon biodegradation potentials. The biodegradation potentials showed large seasonal variations in the Beaufort Sea, probably due to seasonal depletion of available nutrients. Non-nutrient-limited biodegradation potentials followed the order hexadecane > naphthalene >> pristane > benzanthracene. In Cook Inlet, biodegradation potentials for hexadecane and naphthalene were dependent on availability of inorganic nutrients. Biodegradation potentials for pristane and benzanthracene were restricted, probably by resistance to attack by available enzymes in the indigenous population

  2. Effects of simultaneous climate change and geomorphic evolution on thermal characteristics of a shallow Alaskan lake

    Science.gov (United States)

    Griffiths, Jennifer R.; Schindler, Daniel E.; Balistrieri, Laurie S.; Ruggerone, Gregory T.

    2011-01-01

    We used a hydrodynamics model to assess the consequences of climate warming and contemporary geomorphic evolution for thermal conditions in a large, shallow Alaskan lake. We evaluated the effects of both known climate and landscape change, including rapid outlet erosion and migration of the principal inlet stream, over the past 50 yr as well as future scenarios of geomorphic restoration. Compared to effects of air temperature during the past 50 yr, lake thermal properties showed little sensitivity to substantial (~60%) loss of lake volume, as the lake maximum depth declined from 6 m to 4 m driven by outlet erosion. The direction and magnitude of future lake thermal responses will be driven largely by the extent of inlet stream migration when it occurs simultaneously with outlet erosion. Maintaining connectivity with inlet streams had substantial effects on buffering lake thermal responses to warming climate. Failing to account for changing rates and types of geomorphic processes under continuing climate change may misidentify the primary drivers of lake thermal responses and reduce our ability to understand the consequences for aquatic organisms.

  3. Case Study on Ancestry Estimation in an Alaskan Native Family: Identity and Safeguards Against Reductionism.

    Science.gov (United States)

    Bader, Alyssa C; Malhi, Ripan S

    2015-10-01

    Understanding the complexities of ancestry-related identity is a necessary component of ethically sound research related to the genetic ancestry of modern-day communities. This is especially true when working with indigenous populations, given the legal and social implications that genetic ancestry interpretations may have in these communities. This study employs a multicomponent approach to explore the intricacies of ancestry-related identity within one extended family with members who identify as Alaskan Native. The seven participants were interviewed about their own self-identity, perceptions regarding genetic ancestry estimation, and their knowledge of oral family history. Additionally, each participant consented to having his or her genetic ancestry estimated. The researchers also surveyed ancestry-related documents, such as census records, birth certificates, and Certificates of Indian Blood. These three different perspectives-oral family history and self-identity, genetic ancestry estimation, historical and legal documentation-illustrate the complex nature of ancestry-related identity within the context of indigenous and colonial interactions in North America. While estimates of genetic ancestry broadly reflected each individual's self-reported biogeographic ancestry and supported all described and historically reported biological relationships, the estimates did not always match federally recorded blood quantum values, nor did they provide any information on relationships at the tribe or clan level. Employing a multicomponent approach and engaging study participants may help to safeguard against genetic essentialism and provide a more nuanced understanding of ancestry-related identity within a larger political, legal, and historical context.

  4. Microbial activity in Alaskan taiga soils contaminated by crude oil in 1976

    International Nuclear Information System (INIS)

    Monroe, E.M.; Lindstrom, J.E.; Brown, E.J.; Raddock, J.F.

    1995-01-01

    Biodegradation, often measured via microbial activity, includes destruction of environmental pollutants by living microorganisms and is dependent upon many physical and chemical factors. Effects of mineral nutrients and organic matter on biodegradation of Prudhoe Bay crude oil were investigated at a nineteen-year-old oil spill site in Alaskan taiga. Microcosms of two different soil types from the spill site; one undeveloped soil with forest litter and detritus (O horizon) and one more developed with lower organic content (A horizon), were treated with various nitrogen and phosphorus amendments, and incubated for up to six weeks. Each microcosm was sampled periodically and assayed for hydrocarbon mineralization potential using radiorespirometry, for total carbon dioxide respired using gas chromatography, and for numbers of hydrocarbon-degrading bacteria and heterotrophic bacteria using most probable number counting techniques. Organic matter in the O horizon soil along with combinations of mineral nutrients were found to stimulate microbial activity. No combination of mineral nutrient additions to the A horizon soil stimulated any of the parameters above those measured in control microcosms. The results of this study indicate that adding mineral nutrients and tilling the O horizon into the A horizon of subarctic soils contaminated with crude oil, would stimulate microbial activity, and therefore the biodegradation potential, ultimately increasing the rate of destruction of crude oil in these soils

  5. 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.

  6. Mutual aid in oil spill response: The Alaskan north slope model

    International Nuclear Information System (INIS)

    McKenzie, B.; Ingram, N.

    1993-01-01

    The Alaskan Arctic Region provides one of the world's most remote and challenging environments in which to mount an oil spill response. To facilitate the timeliness and appropriateness of the response, Alaska Clean Seas (ACS) and the operators of the North Slope oil fields have implemented a mutual aid concept for spill response. The concept is based upon each operator on the North Slope maintaining its own inventory of personnel [a spill response team (SRT)] and equipment that is available on short notice to respond to a spill. If the spill exceeds the responsible operator's resources, additional resources can be obtained from other operators and/or ACS through mutual aid. Individuals from diverse organizations are brought together in a mutual aid event. To allow different organizations to function effectively in a multi-organizational environment, a common management structure was required. The structure chosen for the North Slope was the incident command system (ICS). A key concern when discussing mutual aid is the provision of indemnification from liability for responders. For the North Slope, ACS and its member companies are indemnified when responding to a spill through provisions in the ACS charter and the ACS response action contract

  7. 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.

  8. Spatial distribution of mercury in southeastern Alaskan streams influenced by glaciers, wetlands, and salmon

    International Nuclear Information System (INIS)

    Nagorski, Sonia A.; Engstrom, Daniel R.; Hudson, John P.; Krabbenhoft, David P.; Hood, Eran; DeWild, John F.; Aiken, George R.

    2014-01-01

    Southeastern Alaska is a remote coastal-maritime ecosystem that is experiencing increased deposition of mercury (Hg) as well as rapid glacier loss. Here we present the results of the first reported survey of total and methyl Hg (MeHg) concentrations in regional streams and biota. Overall, streams draining large wetland areas had higher Hg concentrations in water, mayflies, and juvenile salmon than those from glacially-influenced or recently deglaciated watersheds. Filtered MeHg was positively correlated with wetland abundance. Aqueous Hg occurred predominantly in the particulate fraction of glacier streams but in the filtered fraction of wetland-rich streams. Colonization by anadromous salmon in both glacier and wetland-rich streams may be contributing additional marine-derived Hg. The spatial distribution of Hg in the range of streams presented here shows that watersheds are variably, yet fairly predictably, sensitive to atmospheric and marine inputs of Hg. -- Highlights: • We sampled 21 streams in southeastern Alaska for water, sediments, and biota. • Aqueous Hg showed significant relationships with wetlands and DOC. • Biota had higher mercury in wetland-rich streams than in glacier-fed streams. • Spawning salmon appear to contribute methylmercury to stream foodwebs. -- This original survey of mercury concentration and form in southeastern Alaskan streamwater and biota shows substantial spatial variation linked to landscape factors and salmon influence

  9. Continuously amplified warming in the Alaskan Arctic: Implications for estimating global warming hiatus

    Science.gov (United States)

    Wang, Kang; Zhang, Tingjun; Zhang, Xiangdong; Clow, Gary D.; Jafarov, Elchin E.; Overeem, Irina; Romanovsky, Vladimir; Peng, Xiaoqing; Cao, Bin

    2017-01-01

    Historically, in situ measurements have been notoriously sparse over the Arctic. As a consequence, the existing gridded data of surface air temperature (SAT) may have large biases in estimating the warming trend in this region. Using data from an expanded monitoring network with 31 stations in the Alaskan Arctic, we demonstrate that the SAT has increased by 2.19°C in this region, or at a rate of 0.23°C/decade during 1921–2015. Meanwhile, we found that the SAT warmed at 0.71°C/decade over 1998–2015, which is 2 to 3 times faster than the rate established from the gridded data sets. Focusing on the “hiatus” period 1998–2012 as identified by the Intergovernmental Panel on Climate Change (IPCC) report, the SAT has increased at 0.45°C/decade, which captures more than 90% of the regional trend for 1951–2012. We suggest that sparse in situ measurements are responsible for underestimation of the SAT change in the gridded data sets. It is likely that enhanced climate warming may also have happened in the other regions of the Arctic since the late 1990s but left undetected because of incomplete observational coverage.

  10. No Evidence of Metabolic Depression in Western Alaskan Juvenile Steller Sea Lions (Eumetopias jubatus)

    Science.gov (United States)

    Hoopes, Lisa A.; Rea, Lorrie D.; Christ, Aaron; Worthy, Graham A. J.

    2014-01-01

    Steller sea lion (Eumetopias jubatus) populations have undergone precipitous declines through their western Alaskan range over the last four decades with the leading hypothesis to explain this decline centering around changing prey quality, quantity, or availability for this species (i.e., nutritional stress hypothesis). Under chronic conditions of reduced food intake sea lions would conserve energy by limiting energy expenditures through lowering of metabolic rate known as metabolic depression. To examine the potential for nutritional stress, resting metabolic rate (RMR) and body composition were measured in free-ranging juvenile Steller sea lions (N = 91) at three distinct geographical locations (Southeast Alaska, Prince William Sound, Central Aleutian Islands) using open-flow respirometry and deuterium isotope dilution, respectively. Average sea lion RMR ranged from 6.7 to 36.2 MJ d−1 and was influenced by body mass, total body lipid, and to a lesser extent, ambient air temperature and age. Sea lion pups captured in the Aleutian Islands (region of decline) had significantly greater body mass and total body lipid stores when compared to pups from Prince William Sound (region of decline) and Southeast Alaska (stable region). Along with evidence of robust body condition in Aleutian Island pups, no definitive differences were detected in RMR between sea lions sampled between eastern and western populations that could not be accounted for by higher percent total body lipid content, suggesting that that at the time of this study, Steller sea lions were not experiencing metabolic depression in the locations studied. PMID:24416394

  11. 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%.

  12. Constraining the 2012-2014 growing season Alaskan methane budget using CARVE aircraft measurements

    Science.gov (United States)

    Hartery, S.; Chang, R. Y. W.; Commane, R.; Lindaas, J.; Miller, S. M.; Wofsy, S. C.; Karion, A.; Sweeney, C.; Miller, C. E.; Dinardo, S. J.; Steiner, N.; McDonald, K. C.; Watts, J. D.; Zona, D.; Oechel, W. C.; Kimball, J. S.; Henderson, J.; Mountain, M. E.

    2015-12-01

    Soil in northen latitudes contains rich carbon stores which have been historically preserved via permafrost within the soil bed; however, recent surface warming in these regions is allowing deeper soil layers to thaw, influencing the net carbon exchange from these areas. Due to the extreme nature of its climate, these eco-regions remain poorly understood by most global models. In this study we analyze methane fluxes from Alaska using in situ aircraft observations from the 2012-2014 Carbon in Arctic Reservoir Vulnerability Experiment (CARVE). These observations are coupled with an atmospheric particle transport model which quantitatively links surface emissions to atmospheric observations to make regional methane emission estimates. The results of this study are two-fold. First, the inter-annual variability of the methane emissions was found to be <1 Tg over the area of interest and is largely influenced by the length of time the deep soil remains unfrozen. Second, the resulting methane flux estimates and mean soil parameters were used to develop an empirical emissions model to help spatially and temporally constrain the methane exchange at the Alaskan soil surface. The empirical emissions model will provide a basis for exploring the sensitivity of methane emissions to subsurface soil temperature, soil moisture, organic carbon content, and other parameters commonly used in process-based models.

  13. 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.

  14. River nomads

    DEFF Research Database (Denmark)

    2016-01-01

    sail on the Niger River between Nigeria and Mali. Crossing villages, borders and cultures, they stop only to rest by setting up camp on riverbanks or host villages. In River Nomads, we join the nomadic Kebbawa fishermen on one of their yearly crossing, experiencing their relatively adventurous...

  15. River Piracy

    Indian Academy of Sciences (India)

    There was this highly venerated river Saraswati flowing through. Haryana, Marwar and Bahawalpur in Uttarapath and emptying itself in the Gulf ofKachchh, which has been described in glowing terms by the Rigveda. "Breaking through the mountain barrier", this "swift-flowing tempestuous river surpasses in majesty and.

  16. 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!

  17. 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.

  18. Extending airborne electromagnetic surveys for regional active layer and permafrost mapping with remote sensing and ancillary data, Yukon Flats ecoregion, central Alaska

    Science.gov (United States)

    Pastick, Neal J.; Jorgenson, M. Torre; Wylie, Bruce K.; Minsley, Burke J.; Ji, Lei; Walvoord, Michelle Ann; Smith, Bruce D.; Abraham, Jared D.; Rose, Joshua R.

    2013-01-01

    Machine-learning regression tree models were used to extrapolate airborne electromagnetic resistivity data collected along flight lines in the Yukon Flats Ecoregion, central Alaska, for regional mapping of permafrost. This method of extrapolation (r = 0.86) used subsurface resistivity, Landsat Thematic Mapper (TM) at-sensor reflectance, thermal, TM-derived spectral indices, digital elevation models and other relevant spatial data to estimate near-surface (0–2.6-m depth) resistivity at 30-m resolution. A piecewise regression model (r = 0.82) and a presence/absence decision tree classification (accuracy of 87%) were used to estimate active-layer thickness (ALT) (remote sensing and map data. At site scale, the predicted ALTs were similar to those previously observed for different vegetation types. At the landscape scale, the predicted ALTs tended to be thinner on higher-elevation loess deposits than on low-lying alluvial and sand sheet deposits of the Yukon Flats. The ALT and permafrost maps provide a baseline for future permafrost monitoring, serve as inputs for modelling hydrological and carbon cycles at local to regional scales, and offer insight into the ALT response to fire and thaw processes.

  19. 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.

  20. Connecting Alaskan Youth, Elders, and Scientists in Climate Change Research and Community Resilience

    Science.gov (United States)

    Spellman, K.; Sparrow, E.

    2017-12-01

    Integrated science, technology, engineering and math (STEM) solutions and effective, relevant learning processes are required to address the challenges that a changing climate presents to many Arctic communities. Learning that can both enhance a community's understanding and generate new knowledge about climate change impacts at both local and continental scales are needed to efficiently build the capacity to navigate these changes. The Arctic and Earth STEM Integrating GLOBE and NASA (SIGNs) program is developing a learning model to engage Alaskan rural and indigenous communities in climate change learning, research and action. Youth, elders, educators, community leaders and scientists collaborate to address a pressing local climate change concern. The program trains teams of educators and long-time community members on climate change concepts and environmental observing protocols in face-to-face or online workshops together with Arctic and NASA subject matter experts. Community teams return to their community to identify local data or information needs that align with their student's interests and the observations of local elders. They deepen their understanding of the subject through culturally responsive curriculum materials, and collaborate with a scientist to develop an investigation with their students to address the identified need. Youth make observations using GLOBE (Global Learning and Observations to Benefit the Environment) protocols that best fit the issue, analyze the data they have collected, and utilize indigenous or knowledge, and NASA data to address the issue. The use of GLOBE protocols allow for communities to engage in climate change research at both local and global scales, as over 110 nations worldwide are using these standardized protocols. Teams work to communicate their investigation results back to their community and other scientists, and apply their results to local stewardship action or climate adaptation projects. In this

  1. Linkages Among Climate, Fire, and Thermoerosion in Alaskan Tundra Over the Past Three Millennia

    Science.gov (United States)

    Chipman, M. L.; Hu, F. S.

    2017-12-01

    Amplified Arctic warming may facilitate novel tundra disturbance regimes, as suggested by recent increases in the rate and extent of thermoerosion and fires in some tundra areas. Thermoerosion and wildfire can exacerbate warming by releasing large permafrost carbon stocks, and interactions between disturbance regimes can lead to complex ecosystem feedbacks. We conducted geochemical and charcoal analyses of lake sediments from an Alaskan lake to identify thermoerosion and fire events over the past 3,000 years. Thermoerosion was inferred from lake sediments in the context of modern soil data from retrogressive thaw slumps (RTS). Magnetic susceptibility (MS), Ca:K, and Ca:Sr increased with depth in modern RTS soils and were higher on recently exposed than older slump surfaces. Peaks in bulk density, % CaCO3, Ca:K, Ca:Sr, and MS values in the sediments suggest at least 18 thermoerosion events in the Loon Lake watershed over the past 3,000 years. Charcoal analysis identifies 22 fires over the same period at this site. Temporal variability in these records suggests climate-driven responses of both thermoerosion and fire disturbance regimes, with fewer RTS episodes and fire events during the Little Ice Age than the Medieval Climate Anomaly. Moreover, RTS activity lagged behind catchment fires by 20-30 years (>90% confidence interval), implying that fires facilitated thermoerosion on decadal time scales, possibly because of prolonged active-layer deepening following fire and postfire proliferation of insulative shrub cover. These results highlight the potential for complex interactions between climate, vegetation, and tundra disturbance in response to ongoing warming.

  2. Assessing the Utility of Temporally Dynamic Terrain Indices in Alaskan Moose Resource Selection

    Science.gov (United States)

    Jennewein, J. S.; Hebblewhite, M.; Meddens, A. J.; Gilbert, S.; Vierling, L. A.; Boelman, N.; Eitel, J.

    2017-12-01

    The accelerated warming in arctic and boreal regions impacts ecosystem structure and plant species distribution, which have secondary effects on wildlife. In summer months, moose (Alces alces) are especially vulnerable to changes in the availability and quality of forage and foliage cover due to their thermoregulatory needs and high energetic demands post calving. Resource selection functions (RSFs) have been used with great success to model such tradeoffs in habitat selection. Recently, RSFs have expanded to include more dynamic representations of habitat selection through the use of time-varying covariates such as dynamic habitat indices. However, to date few studies have investigated dynamic terrain indices, which incorporate long-term, highly-dynamic meteorological data (e.g., albedo, air temperature) and their utility in modeling habitat selection. The purpose of this study is to compare two dynamic terrain indices (i.e., solar insolation and topographic wetness) to their static counterparts in Alaskan moose resource selection over a ten-year period (2008-2017). Additionally, the utility of a dynamic wind-shelter index is assessed. Three moose datasets (n=130 total), spanning a north-to-south gradient in Alaska, are analyzed independently to assess location-specific resource selection. The newly-released, high-resolution Arctic Digital Elevation Model (5m2) is used as the terrain input into both dynamic and static indices. Dynamic indices are programmed with meteorological data from the North American Regional Analysis (NARR) and NASA's Goddard Earth Sciences Data and Information Services Center (GES-DISC) databases. Static wetness and solar insolation indices are estimated using only topographic parameters (e.g., slope, aspect). Preliminary results from pilot analyses suggest that dynamic terrain indices may provide novel insights into resource selection of moose that could not be gained when using static counterparts. Future applications of such dynamic

  3. Influence of fire frequency on carbon consumption in Alaskan blackspruce forests

    Science.gov (United States)

    Hoy, E.; Kasischke, E. S.

    2014-12-01

    Increasing temperatures and drier conditions within the boreal forests of Alaska have resulted in increases in burned area and fire frequency, which alter carbon storage and emissions. In particular, analyses of satellite remote sensing data showed that >20% of the area impacted by fires in interior Alaska occurred in areas that had previously burned since 1950 (e.g., short to intermediate interval fires). Field studies showed that in immature black spruce forests ~ 35 to 55 years old organic layers experienced deep burning regardless of topographic position or seasonality of burning, factors that control depth of burning in mature black spruce forests. Here, refinements were made to a carbon consumption model to account for variations in fuel loads and fraction of carbon consumed associated with fire frequency based on quantifying burned area in recently burned sites using satellite imagery. An immature black spruce (Picea mariana) fuel type (including stands of ~0-50 years) was developed which contains new ground-layer carbon consumption values in order to more accurately account for differences between various age classes of black spruce forest. Both versions of the model were used to assess carbon consumption during 100 fire events (over 4.4 x 10^6 ha of burned area) from two recent ultra-large fire years (2004 and 2005). Using the improved model to better attribute fuel type and consumption resulted in higher ground-layer carbon consumption (4.9% in 2004 and 6.8% in 2005) than previously estimated. These adjustments in ground-layer burning resulted in total carbon consumption within 2004 and 2005 of 63.5 and 42.0 Tg of carbon, respectively. Results from this research could be incorporated into larger scale modeling efforts to better assess changes in the climate-fire-vegetation dynamics in interior Alaskan boreal forests, and to understand the impacts of these changes on carbon consumption and emissions.

  4. Using fluorescence spectroscopy to gain new insights into seasonal patterns of stream DOC concentrations in an alpine, headwater catchment underlain by discontinuous permafrost in Wolf Creek Research Basin, Yukon Territory, Canada

    Science.gov (United States)

    Shatilla, N. J.; Carey, S.; Tang, W.

    2017-12-01

    The Canadian subarctic is experiencing rapid climate warming resulting in decreased depth and duration of snowcover, decreased permafrost extent and time span of seasonal frozen ground resulting in increased active layer depth, and increased frequency and magnitude of rainfall events during the growing season. These changes challenge our conceptual models of permafrost hydrology as comparisons between recent and historical streamflow records show an emerging secondary post-freshet peak in flow in recent years along with enhanced winter flows. Long-term monitoring of Granger Creek (7.6km2), an alpine watershed underlain by discontinuous permafrost located within Wolf Creek Research Basin (176km2) in Yukon Territory, Canada provided a multi-decadal record of hydro-meteorological measurements. Granger Creek experienced warmer and wetter summers in 2015-6 compared to 2001-8, and an altered streamflow pattern with an earlier spring freshet and peak in dissolved organic carbon (DOC) concentrations. DOC concentrations post-freshet remained low at both the headwater and meso-catchment scale, which contradicts trends of increasing DOC concentrations observed in larger river systems. Hysteresis loops of sub-hourly measurements of streamflow, salinity and chromophoric dissolved organic matter (CDOM) were analyzed to provide new insights into how hydrological connectivity at the headwater scale affected the timing of solute release with supporting information from optical indices calculated from fluorescence spectroscopy. These indices provided a more nuanced view of catchment dynamics than the DOC concentrations. The composition and quality of DOM varied throughout the growing season with the delivery of older, terrestrially-derived material corresponding to high DOC concentrations at the onset of spring freshet when the catchment was initially being flushed. The origin and quality of stream DOM shifted throughout the rest of the season to newer, more easily mobilized DOM

  5. The footprint of Alaskan tundra fires during the past half-century: implications for surface properties and radiative forcing

    International Nuclear Information System (INIS)

    Rocha, Adrian V; Loranty, Michael M; Higuera, Phil E; Mack, Michelle C; Hu Fengsheng; Jones, Benjamin M; Breen, Amy L; Rastetter, Edward B; Shaver, Gus R; Goetz, Scott J

    2012-01-01

    Recent large and frequent fires above the Alaskan arctic circle have forced a reassessment of the ecological and climatological importance of fire in arctic tundra ecosystems. Here we provide a general overview of the occurrence, distribution, and ecological and climate implications of Alaskan tundra fires over the past half-century using spatially explicit climate, fire, vegetation and remote sensing datasets for Alaska. Our analyses highlight the importance of vegetation biomass and environmental conditions in regulating tundra burning, and demonstrate that most tundra ecosystems are susceptible to burn, providing the environmental conditions are right. Over the past two decades, fire perimeters above the arctic circle have increased in size and importance, especially on the North Slope, indicating that future wildfire projections should account for fire regime changes in these regions. Remote sensing data and a literature review of thaw depths indicate that tundra fires have both positive and negative implications for climatic feedbacks including a decadal increase in albedo radiative forcing immediately after a fire, a stimulation of surface greenness and a persistent long-term (>10 year) increase in thaw depth. In order to address the future impact of tundra fires on climate, a better understanding of the control of tundra fire occurrence as well as the long-term impacts on ecosystem carbon cycling will be required. (letter)

  6. A geochemical characterization of cold-water natural acid rock drainage at the Zn–Pb XY deposit, Yukon, Canada

    International Nuclear Information System (INIS)

    Gault, Kristen B.; Gammon, Paul; Fortin, Danielle

    2015-01-01

    Highlights: • Characterizes the waters and minerals of a natural acid rock drainage (ARD). • Demonstrates that cold climate ARD is mostly similar to temperate systems. • Cold-climate differences impact kinetic rates and hydrologic seasonality. • Demonstrates that thermodynamic equilibrium governs the ARD system. • Demonstrates that extraneous inputs can be detected in the system. - Abstract: Acid rock drainage (ARD) is considered to be temperature-limited due to the diminished activity of Fe(II)-oxidizing microbes at low temperatures. Nonetheless, ARD streams are present in cold climates. This study presents a geochemical characterization of a cold climate ARD creek at the Zn–Pb XY deposit in Yukon, Canada, which showed highly elevated concentrations of dissolved zinc (up to 475 mg/L). Acid rock drainage at the XY deposit is likely generated via subsurface abiotic and biotic oxidation of sulfide minerals, and then exits as seeps at the headwaters of the creek. The uppermost reaches of the creek have the lowest pH levels (pH 3.3) and highest metal concentrations, with prolific precipitation of iron-hydroxysulfate and -oxyhydroxide mineral precipitates (schwertmannite, jarosite, and goethite), present as terraced iron formations (TIFs) at one sampling location. The lower reaches of the creek show a progressive pH increase (up to pH level 4.9) which occurs due to Fe(III)- and Al-hydrolysis, the neutralizing influence of carbonate-rich strata and/or ground waters, and dilution by surface waters entering the creek. Progressive pH neutralization causes a change in precipitate mineralogy to X-ray amorphous Al-hydroxysulfates, with a composition similar to aluminite and hydrobasaluminite, and amorphous Al(OH)_3. Natural attenuation of Cd, Zn, and Pb occurred downstream from the headwater seeps, which was likely influenced by adsorption reactions involving both metal-sulfate anions and metal-sulfate ternary complexes. Generally, the concentrations of Cd, Zn, and

  7. 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 public school…

  8. Age, Gender, Biometry, Refractive Error, and the Anterior Chamber Angle among Alaskan Eskimos

    Science.gov (United States)

    Wojciechowski, Robert; Congdon, Nathan; Anninger, William; Broman, Aimee Teo

    2011-01-01

    Background The prevalence of angle-closure glaucoma (ACG) is greater for Eskimos/Inuit than it is for any other ethnic group in the world. Although it has been suggested that this prevalence may be due to a population tendency toward shallower anterior chamber angles, available evidence for other populations such as Chinese with high rates of ACG has not consistently demonstrated such a tendency. Methods A reticule, slit-lamp, and standard Goldmann one-mirror goniolens were used to make measurements in the anterior chamber (AC) angle according to a previously reported protocol for biometric gonioscopy (BG) (Ophthalmology 1999;106:2161–7). Measurements were made in all four quadrants of one eye among 133 phakic Alaskan Eskimos aged 40 years and older. Automatic refraction, dilated examination of the anterior segment and optic nerve, and A-scan measurements of AC depth, lens thickness, and axial length were also carried out for all subjects. Results Both central and peripheral AC measurements for the Eskimo subjects were significantly lower than those previously reported by us for Chinese, blacks, and whites under the identical protocol. Eskimos also seemed to have somewhat more hyperopia. There were no differences in biometric measurements between men and women in this Eskimo population. Angle measurements by BG seemed to decline more rapidly over life among Eskimos and Chinese than blacks or whites. Although there was a significant apparent decrease in AC depth, increase in lens thickness, and increase in hyperopia with age among Eskimos, all of these trends seemed to reverse in the seventh decade and beyond. Conclusions Eskimos do seem to have shallower ACs than do other racial groups. Measurements of the AC angle seem to decline more rapidly over life among Eskimos than among blacks or whites, a phenomenon also observed by us among Chinese, another group with high ACG prevalence. This apparent more rapid decline may be due to a cohort effect with higher

  9. Site-Specific Bluff Recession Rates Measured on the Alaskan Beaufort Sea Coast

    Science.gov (United States)

    Richmond, B.; Gadd, P.; Crowell, W.

    2017-12-01

    OverviewThe effects of climate change are being studied globally with coastal erosion in Arctic regions of particular concern. In support of Hilcorp Alaska's Northstar Development, short- and long-term bluff recession rates have been documented at a pipeline shore crossing located in Gwydyr Bay on the Alaskan Beaufort Sea coast. These data are presented, along with the predominant forcing mechanisms, and compared to local and regional recession rates recently published by the U.S. Geological Survey (USGS). Arctic Bluff RecessionCoastal retreat along the northern coast of Alaska occurs at two different rates: infrequent, but rapid erosion induced by strong westerly storms, and seasonal retreat related to thawing and sediment removal under more moderate wave conditions. Variability in the rate of bluff retreat is related to a number of factors, including bluff composition (ice content and sediment type), existence of a fronting beach, and wave exposure. Measured Bluff Recession at the Northstar Pipeline Shore CrossingThe location of the Northstar Development pipeline shore crossing was chosen based on analysis of historical aerial photos acquired between 1949 and 1996. Over this 47-year period, the average annualized rate of bluff retreat in the study area ranged from 1.6 to 3.0 ft/yr. Beginning in 1996, ground-based shoreline monitoring surveys have been conducted along the bluff and ten shore-perpendicular transects at the site. The rates of bluff retreat derived from the survey data have been modest, ranging from no change to 5.8 ft/yr. The monitoring surveys indicate that waves and currents erode the bluffs by direct impact only during infrequent, but strong westerly storms that promote a short-term rise in sea level (storm surge). The more prevalent easterly storms can cause set-down, or reduction in the sea level which limits direct wave impact on the bluff, thereby decreasing the potential for wave induced erosion. Comparative StudiesRecent studies conducted

  10. Brucella Antibodies in Alaskan True Seals and Eared Seals—Two Different Stories

    Directory of Open Access Journals (Sweden)

    Ingebjørg H. Nymo

    2018-01-01

    Full Text Available Brucella pinnipedialis was first isolated from true seals in 1994 and from eared seals in 2008. Although few pathological findings have been associated with infection in true seals, reproductive pathology including abortions, and the isolation of the zoonotic strain type 27 have been documented in eared seals. In this study, a Brucella enzyme-linked immunosorbent assay (ELISA and the Rose Bengal test (RBT were initially compared for 206 serum samples and a discrepancy between the tests was found. Following removal of lipids from the serum samples, ELISA results were unaltered while the agreement between the tests was improved, indicating that serum lipids affected the initial RBT outcome. For the remaining screening, we used ELISA to investigate the presence of Brucella antibodies in sera of 231 eared and 1,412 true seals from Alaskan waters sampled between 1975 and 2011. In eared seals, Brucella antibodies were found in two Steller sea lions (Eumetopias jubatus (2% and none of the 107 Northern fur seals (Callorhinus ursinus. The low seroprevalence in eared seals indicate a low level of exposure or lack of susceptibility to infection. Alternatively, mortality due to the Brucella infection may remove seropositive animals from the population. Brucella antibodies were detected in all true seal species investigated; harbor seals (Phoca vitulina (25%, spotted seals (Phoca largha (19%, ribbon seals (Histriophoca fasciata (16%, and ringed seals (Pusa hispida hispida (14%. There was a low seroprevalence among pups, a higher seroprevalence among juveniles, and a subsequent decreasing probability of seropositivity with age in harbor seals. Similar patterns were present for the other true seal species; however, solid conclusions could not be made due to sample size. This pattern is in accordance with previous reports on B. pinnipedialis infections in true seals and may suggest environmental exposure to B. pinnipedialis at the juvenile stage, with a

  11. Guideline-Concordant Cancer Care and Survival Among American Indian/Alaskan Native Patients

    Science.gov (United States)

    Javid, Sara H.; Varghese, Thomas K.; Morris, Arden M.; Porter, Michael P.; He, Hao; Buchwald, Dedra; Flum, David R.

    2014-01-01

    BACKGROUND American Indians/Alaskan Natives (AI/ANs) have the worst 5-year cancer survival of all racial/ethnic groups in the United States. Causes for this disparity are unknown. The authors of this report examined the receipt of cancer treatment among AI/AN patients compared with white patients. METHODS This was a retrospective cohort study of 338,204 patients who were diagnosed at age ≥65 years with breast, colon, lung, or prostate cancer between 1996 and 2005 in the Surveillance, Epidemiology, and End Results-Medicare database. Nationally accepted guidelines for surgical and adjuvant therapy and surveillance were selected as metrics of optimal, guideline-concordant care. Treatment analyses compared AI/ANs with matched whites. RESULTS Across cancer types, AI/ANs were less likely to receive optimal cancer treatment and were less likely to undergo surgery (P ≤ .025 for all cancers). Adjuvant therapy rates were significantly lower for AI/AN patients with breast cancer (P <.001) and colon cancer (P = .001). Rates of post-treatment surveillance also were lower among AI/ANs and were statistically significantly lower for AI/AN patients with breast cancer (P = .002) and prostate cancer (P <.001). Nonreceipt of optimal cancer treatment was associated with significantly worse survival across cancer types. Disease-specific survival for those who did not undergo surgery was significantly lower for patients with breast cancer (hazard ratio [HR], 0.62), colon cancer (HR, 0.74), prostate cancer (HR, 0.52), and lung cancer (HR, 0.36). Survival rates also were significantly lower for those patients who did not receive adjuvant therapy for breast cancer (HR, 0.56), colon cancer (HR, 0.59), or prostate cancer (HR, 0.81; all 95% confidence intervals were <1.0). CONCLUSIONS Fewer AI/AN patients than white patients received guideline-concordant cancer treatment across the 4 most common cancers. Efforts to explain these differences are critical to improving cancer care and

  12. Empirically constrained estimates of Alaskan regional Net Ecosystem Exchange of CO2, 2012-2014

    Science.gov (United States)

    Commane, R.; Lindaas, J.; Benmergui, J. S.; Luus, K. A.; Chang, R. Y. W.; Miller, S. M.; Henderson, J.; Karion, A.; Miller, J. B.; Sweeney, C.; Miller, C. E.; Lin, J. C.; Oechel, W. C.; Zona, D.; Euskirchen, E. S.; Iwata, H.; Ueyama, M.; Harazono, Y.; Veraverbeke, S.; Randerson, J. T.; Daube, B. C.; Pittman, J. V.; Wofsy, S. C.

    2015-12-01

    We present data-driven estimates of the regional net ecosystem exchange of CO2 across Alaska for three years (2012-2014) derived from CARVE (Carbon in the Arctic Reservoirs Vulnerability Experiment) aircraft measurements. Integrating optimized estimates of annual NEE, we find that the Alaskan region was a small sink of CO2 during 2012 and 2014, but a significant source of CO2 in 2013, even before including emissions from the large forest fire season during 2013. We investigate the drivers of this interannual variability, and the larger spring and fall emissions of CO2 in 2013. To determine the optimized fluxes, we couple the Polar Weather Research and Forecasting (PWRF) model with the Stochastic Time-Inverted Lagrangian Transport (STILT) model, to produce footprints of surface influence that we convolve with a remote-sensing driven model of NEE across Alaska, the Polar Vegetation Photosynthesis and Respiration Model (Polar-VPRM). For each month we calculate a spatially explicit additive flux (ΔF) by minimizing the difference between the measured profiles of the aircraft CO2 data and the modeled profiles, using a framework that combines a uniform correction at regional scales and a Bayesian inversion of residuals at smaller scales. A rigorous estimate of total uncertainty (including atmospheric transport, measurement error, etc.) was made with a combination of maximum likelihood estimation and Monte Carlo error propagation. Our optimized fluxes are consistent with other measurements on multiple spatial scales, including CO2 mixing ratios from the CARVE Tower near Fairbanks and eddy covariance flux towers in both boreal and tundra ecosystems across Alaska. For times outside the aircraft observations (Dec-April) we use the un-optimized polar-VPRM, which has shown good agreement with both tall towers and eddy flux data outside the growing season. This approach allows us to robustly estimate the annual CO2 budget for Alaska and investigate the drivers of both the

  13. First Steps to the Last Frontier: Programming Suggestions for Alaskan Adventures.

    Science.gov (United States)

    Miner, Todd

    This article provides an overview of trip programming in Alaska for those seeking a low-cost wilderness adventure. Alaska is a land of glaciers, mountains, lakes, rivers, forests, and wildlife. Safety is a major concern when traveling in Alaska. A local guide or outdoor educator can assist with safety and logistical planning. Travelers should plan…

  14. Antecedent Rivers

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 8. Antecedent Rivers - Ganga Is Older Than Himalaya. K S Valdiya. General Article Volume 1 Issue 8 August 1996 pp 55-63. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/001/08/0055-0063 ...

  15. RIVER STATE

    African Journals Online (AJOL)

    principals randomly selected from one hundred secondary schools in Cross River State. The data collected ... There was no siyriificant influerlce of gender on principals' leadership styles effectiveness. ... result of the cultural stereotyping of males and females by .... schools were single sex boys, another 10 were single sex ...

  16. Using Water Isotope Tracers to Investigate Past and Present Water Balance Conditions in the Old Crow Flats, Yukon Territory

    Science.gov (United States)

    Turner, K.; Wolfe, B. B.; Edwards, T. W.

    2010-12-01

    The Old Crow Flats (OCF), Yukon Territory, is a wetland of international significance that comprises approximately 2700 shallow thermokarst lakes. Located near the northern limit of the boreal forest, the OCF provides vital habitat for abundant wildlife including waterfowl, moose, muskrat, and the Porcupine Caribou Herd, which support the traditional lifestyle of the Vuntut Gwitchin First Nation. Thermokarst lakes, which occupy vast northern regions, are greatly influenced by climate conditions. In the OCF and other regions there have been observations of decreasing water levels and an increase in frequency of lake drainage events over recent decades. Though there is widespread concern that thermokarst landscape changes are accelerating as a result of ongoing climate change, there are few studies that have investigated current and past variability of lake water balances and climate interactions at the landscape scale. As part of a Government of Canada International Polar Year multidisciplinary project, the present and past hydrology of lakes spanning the OCF are being investigated using water isotope tracers and paleolimnological approaches. Water samples were obtained from 57 lakes three times over three ice-free seasons (2007-09) and analyzed for oxygen and hydrogen isotope composition in order to capture seasonal and interannual changes in water balance conditions. Results highlight strong diversity in the hydrology of lakes throughout the OCF. Based on patterns of isotopic evolution and calculations of input source compositions and evaporation-to-inflow ratios, we identified snowmelt-dominated, rainfall-dominated, groundwater-influenced, evaporation-dominated and drained lake types, which represent the dominant hydrological processes influencing lake water balances. Lake physical and catchment land cover characteristics influence dominant input type (rain or snow). Snowmelt-dominated catchments are large relative to lake surface areas and typically contain

  17. Distribution, stock composition and timing, and tagging response of wild Chinook Salmon returning to a large, free-flowing river basin

    Science.gov (United States)

    Eiler, John H.; Masuda, Michele; Spencer, Ted R.; Driscoll, Richard J.; Schreck, Carl B.

    2014-01-01

    Chinook Salmon Oncorhynchus tshawytscha returns to the Yukon River basin have declined dramatically since the late 1990s, and detailed information on the spawning distribution, stock structure, and stock timing is needed to better manage the run and facilitate conservation efforts. A total of 2,860 fish were radio-tagged in the lower basin during 2002–2004 and tracked upriver. Fish traveled to spawning areas throughout the basin, ranging from several hundred to over 3,000 km from the tagging site. Similar distribution patterns were observed across years, suggesting that the major components of the run were identified. Daily and seasonal composition estimates were calculated for the component stocks. The run was dominated by two regional components comprising over 70% of the return. Substantially fewer fish returned to other areas, ranging from 2% to 9% of the return, but their collective contribution was appreciable. Most regional components consisted of several principal stocks and a number of small, spatially isolated populations. Regional and stock composition estimates were similar across years even though differences in run abundance were reported, suggesting that the differences in abundance were not related to regional or stock-specific variability. Run timing was relatively compressed compared with that in rivers in the southern portion of the species’ range. Most stocks passed through the lower river over a 6-week period, ranging in duration from 16 to 38 d. Run timing was similar for middle- and upper-basin stocks, limiting the use of timing information for management. The lower-basin stocks were primarily later-run fish. Although differences were observed, there was general agreement between our composition and timing estimates and those from other assessment projects within the basin, suggesting that the telemetry-based estimates provided a plausible approximation of the return. However, the short duration of the run, complex stock structure, and

  18. Haemosporidian parasite infections in grouse and ptarmigan: Prevalence and genetic diversity of blood parasites in resident Alaskan birds

    Science.gov (United States)

    Smith, Matthew M.; Van Hemert, Caroline R.; Merizon, Richard

    2016-01-01

    Projections related to future climate warming indicate the potential for an increase in the distribution and prevalence of blood parasites in northern regions. However, baseline data are lacking for resident avian host species in Alaska. Grouse and ptarmigan occupy a diverse range of habitat types throughout the northern hemisphere and are among the most well-known and important native game birds in North America. Information regarding the prevalence and diversity of haemosporidian parasites in tetraonid species is limited, with few recent studies and an almost complete lack of genetic data. To better understand the genetic diversity of haemosporidian parasites in Alaskan tetraonids and to determine current patterns of geographic range and host specificity, we used molecular methods to screen 459 tissue samples collected from grouse and ptarmigan species across multiple regions of Alaska for infection by Leucocytozoon, Haemoproteus, and Plasmodium blood parasites. Infections were detected in 342 individuals, with overall apparent prevalence of 53% for Leucocytozoon, 21% for Haemoproteus, and 9% for Plasmodium. Parasite prevalence varied by region, with different patterns observed between species groups (grouse versus ptarmigan). Leucocytozoon was more common in ptarmigan, whereas Haemoproteus was more common in grouse. We detected Plasmodium infections in grouse only. Analysis of haemosporidian mitochondrial DNA cytochrome b sequences revealed 23 unique parasite haplotypes, several of which were identical to lineages previously detected in other avian hosts. Phylogenetic analysis showed close relationships between haplotypes from our study and those identified in Alaskan waterfowl for Haemoproteus and Plasmodium parasites. In contrast, Leucocytozoon lineages were structured strongly by host family. Our results provide some of the first genetic data for haemosporidians in grouse and ptarmigan species, and provide an initial baseline on the prevalence and diversity

  19. Mapping Deep Low Velocity Zones in Alaskan Arctic Coastal Permafrost using Seismic Surface Waves

    Science.gov (United States)

    Dou, S.; Ajo Franklin, J. B.; Dreger, D. S.

    2012-12-01

    Permafrost degradation may be an important amplifier of climate change; Thawing of near-surface sediments holds the potential of increasing greenhouse gas emissions due to microbial decomposition of preserved organic carbon. Recently, the characterization of "deep" carbon pools (several meters below the surface) in circumpolar frozen ground has increased the estimated amount of soil carbon to three times higher than what was previously thought. It is therefore potentially important to include the characteristics and processes of deeper permafrost strata (on the orders of a few to tens of meters below surface) in climate models for improving future predictions of accessible carbon and climate feedbacks. This extension is particularly relevant if deeper formations are not completely frozen and may harbor on-going microbial activity despite sub-zero temperatures. Unfortunately, the characterization of deep permafrost systems is non-trivial; logistics and drilling constraints often limit direct characterization to relatively shallow units. Geophysical measurements, either surface or airborne, are often the most effective tools for evaluating these regions. Of the available geophysical techniques, the analysis of seismic surface waves (e.g. MASW) has several unique advantages, mainly the ability to provide field-scale information with good depth resolution as well as penetration (10s to 100s of m with small portable sources). Surface wave methods are also able to resolve low velocity regions, a class of features that is difficult to characterize using traditional P-wave refraction methods. As part of the Department of Energy (DOE) Next-Generation Ecosystem Experiments (NGEE-Arctic) project, we conducted a three-day seismic field survey (May 12 - 14, 2012) at the Barrow Environmental Observatory, which is located within the Alaskan Arctic Coastal Plain. Even though permafrost at the study site is continuous, ice-rich and thick (>= 350m), our Multichannel Analysis of

  20. Antecedent Rivers

    Indian Academy of Sciences (India)

    far north of the high NandaDevi (7,817 m) - Api Nampa. (7,132 m) range of the Himadri. The Sindhu flows northwestwards, the Satluj goes west, the Karnali takes the southerly course and the Tsangpo flows east. These rivers flow through their pristine channels, carved out at the very outset about 50 to 55 m.y (million years) ...

  1. 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.

  2. Multi-Year Estimates of Regional Alaskan Net CO2 Exchange: Constraining a Remote-Sensing Based Model with Aircraft Observations

    Science.gov (United States)

    Lindaas, J.; Commane, R.; Luus, K. A.; Chang, R. Y. W.; Miller, C. E.; Dinardo, S. J.; Henderson, J.; Mountain, M. E.; Karion, A.; Sweeney, C.; Miller, J. B.; Lin, J. C.; Daube, B. C.; Pittman, J. V.; Wofsy, S. C.

    2014-12-01

    The Alaskan region has historically been a sink of atmospheric CO2, but permafrost currently stores large amounts of carbon that are vulnerable to release to the atmosphere as northern high-latitudes continue to warm faster than the global average. We use aircraft CO2 data with a remote-sensing based model driven by MODIS satellite products and validated by CO2 flux tower data to calculate average daily CO2 fluxes for the region of Alaska during the growing seasons of 2012 and 2013. Atmospheric trace gases were measured during CARVE (Carbon in Arctic Reservoirs Vulnerability Experiment) aboard the NASA Sherpa C-23 aircraft. For profiles along the flight track, we couple the Weather Research and Forecasting (WRF) model with the Stochastic Time-Inverted Lagrangian Transport (STILT) model, and convolve these footprints of surface influence with our remote-sensing based model, the Polar Vegetation Photosynthesis Respiration Model (PolarVPRM). We are able to calculate average regional fluxes for each month by minimizing the difference between the data and model column integrals. Our results provide a snapshot of the current state of regional Alaskan growing season net ecosystem exchange (NEE). We are able to begin characterizing the interannual variation in Alaskan NEE and to inform future refinements in process-based modeling that will produce better estimates of past, present, and future pan-Arctic NEE. Understanding if/when/how the Alaskan region transitions from a sink to a source of CO2 is crucial to predicting the trajectory of future climate change.

  3. 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.

  4. Comparative baseline levels of mercury, Hsp 70 and Hsp 60 in subsistence fish from the Yukon-Kuskokwim delta region of Alaska.

    Science.gov (United States)

    Duffy, L K; Scofield, E; Rodgers, T; Patton, M; Bowyer, R T

    1999-10-01

    In subsistence fish; northern pike (Esox lucius), burbot (Lota lota), whitefish (Coregonus nelsoni), grayling (Thymallus arcticus) and sheefish (Stenodus lencichthys), we determined the Hsp 60 and Hsp 70 levels in 31 samples from adult fish gills. A dot-blot analysis using antibodies to either Hsp 70 or Hsp 60 showed the average Hsp 70 concentration was 9.1 microg/mg protein, while the average Hsp 60 concentration was 147.4 microg/mg protein. Mercury levels in muscle tissue in these fish averaged 0.382 ppm. Using a subset of samples (n = 24), we determined that the major component in the muscle of Alaskan subsistence fish was methyl mercury. No correlation was observed between Hsp 60 or Hsp 70 expression in gill tissue and mercury concentrations in muscle tissue. Hsp 60 and Hsp 70 protein levels in the gills were correlated.

  5. 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.

  6. 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.

  7. River Corridor Easements

    Data.gov (United States)

    Vermont Center for Geographic Information — A River Corridor Easement (RCE) is an area of conserved land adjacent to a river or stream that was conserved to permanently protect the lateral area the river needs...

  8. Quaternary sedimentation of the Alaskan Beaufort shelf: Influence of regional tectonics, fluctuating sea levels, and glacial sediment sources

    Science.gov (United States)

    Dinter, D.A.

    1985-01-01

    The offshore stratigraphy of the Quaternary Gubik Formation of Arctic Alaska has been studied on high-resolution seismic profiles with a maximum sub-seafloor penetration of about 100 m. In general, marine transgressive subunits of the Gubik Formation are wedge-shaped on the shelf, thickening slightly seaward to the shelf break, beyond which they are offset by landslides and slumps. Beneath the eastern third of the Alaskan Beaufort shelf, active folding has created two persistent structural depressions, the Eastern and Western Wedge Terranes, in which the wedge morphology is especially well developed. The youngest transgressive marine wedge, which was deposited in such a way as to fill these depressions, leaving a generally flat present-day shelf surface, is inferred to be late Wisconsin or younger in age because it overlies a prominent disconformity interpreted to have been formed during the late Wisconsin glacial sea-level minimum. The thickness of this youngest wedge, Unit A, locally exceeds 40 m on the outer shelf, yet apparently relict gravel deposits collected from its seabed surface indicate that the depositional rate is presently quite low on the middle and outer shelf. Lithologies of the gravels are exotic to Alaska, but similar to suites exposed in the Canadian Arctic Islands. These observations suggest a depositional scenario in which the retreating Laurentide Ice Sheet shed sediment-laden icebergs from the Canadian Arctic Islands into the Arctic Ocean following the late Wisconsin glacial maximum. These bergs were then rafted westward by the Beaufort Gyre and grounded on the Alaskan shelf by northeasterly prevailing winds. Especially large numbers of bergs accumulated in the wedge terrane embayments-created as sea level rose-and melted there, filling the embayments with their sedimentary cargo. As glacial retreat slowed, depositional rates on the shelf dwindled. This mode of deposition in the Alaskan Beaufort wedge terranes may be typical of early post

  9. 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

  10. River Diversions and Shoaling

    National Research Council Canada - National Science Library

    Letter, Jr., Joseph V; Pinkard, Jr., C. F; Raphelt, Nolan K

    2008-01-01

    This Coastal and Hydraulics Engineering Technical Note describes the current knowledge of the potential impacts of river diversions on channel morphology, especially induced sedimentation in the river channel...

  11. GeoFORCE Alaska: Four-Year Field Program Brings Rural Alaskan High School Students into the STEM Pipeline

    Science.gov (United States)

    Fowell, S. J.; Rittgers, A.; Stephens, L.; Hutchinson, S.; Peters, H.; Snow, E.; Wartes, D.

    2016-12-01

    GeoFORCE Alaska is a four-year, field-based, summer geoscience program designed to raise graduation rates in rural Alaskan high schools, encourage participants to pursue college degrees, and increase the diversity of Alaska's technical workforce. Residents of predominantly Alaska Native villages holding degrees in science, technology, engineering, or math (STEM) bring valuable perspectives to decisions regarding management of cultural and natural resources. However, between 2010 and 2015 the average dropout rate for students in grades 7-12 was 8.5% per year in the North Slope School District and 7% per year in the Northwest Arctic School District. 2015 graduation rates were 70% and 75%, respectively. Statewide statistics highlight the challenge for Alaska Native students. During the 2014-2015 school year alone 37.6% of Alaska Native students dropped out of Alaskan public schools. At the college level, Alaska Native students are underrepresented in University of Alaska Fairbanks (UAF) science departments. Launched in 2012 by UAF in partnership with the longstanding University of Texas at Austin program, GeoFORCE applies the cohort model, leading the same group of high school students on geological field academies during four consecutive summers. Through a combination of active learning, teamwork, and hands-on projects at spectacular geological locations, students gain academic skills and confidence that facilitate high school and college success. To date, GeoFORCE Alaska has recruited two cohorts. 78% of these students identify as Alaska Native, reflecting community demographics. The inaugural cohort of 18 students from the North Slope Borough completed the Fourth-Year Academy in summer 2015. 94% of these students graduated from high school, at least 72% plan to attend college, and 33% will major in geoscience. A second cohort of 34 rising 9th and 10th graders entered the program in 2016. At the request of corporate sponsors, this cohort was recruited from both the

  12. Modeling Fire Severity in Black Spruce Stands in the Alaskan Boreal Forest Using Spectral and Non-Spectral Geospatial Data

    Science.gov (United States)

    Barrett, K.; Kasischke, E. S.; McGuire, A. D.; Turetsky, M. R.; Kane, E. S.

    2010-01-01

    Biomass burning in the Alaskan interior is already a major disturbance and source of carbon emissions, and is likely to increase in response to the warming and drying predicted for the future climate. In addition to quantifying changes to the spatial and temporal patterns of burned areas, observing variations in severity is the key to studying the impact of changes to the fire regime on carbon cycling, energy budgets, and post-fire succession. Remote sensing indices of fire severity have not consistently been well-correlated with in situ observations of important severity characteristics in Alaskan black spruce stands, including depth of burning of the surface organic layer. The incorporation of ancillary data such as in situ observations and GIS layers with spectral data from Landsat TM/ETM+ greatly improved efforts to map the reduction of the organic layer in burned black spruce stands. Using a regression tree approach, the R2 of the organic layer depth reduction models was 0.60 and 0.55 (pb0.01) for relative and absolute depth reduction, respectively. All of the independent variables used by the regression tree to estimate burn depth can be obtained independently of field observations. Implementation of a gradient boosting algorithm improved the R2 to 0.80 and 0.79 (pb0.01) for absolute and relative organic layer depth reduction, respectively. Independent variables used in the regression tree model of burn depth included topographic position, remote sensing indices related to soil and vegetation characteristics, timing of the fire event, and meteorological data. Post-fire organic layer depth characteristics are determined for a large (N200,000 ha) fire to identify areas that are potentially vulnerable to a shift in post-fire succession. This application showed that 12% of this fire event experienced fire severe enough to support a change in post-fire succession. We conclude that non-parametric models and ancillary data are useful in the modeling of the surface

  13. The Black Mountain tectonic zone--a reactivated northeast-trending crustal shear zone in the Yukon-Tanana Upland of east-central Alaska: Chapter D 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)

    O'Neill, J. Michael; Day, Warren C.; Alienikoff, John N.; Saltus, Richard W.; Gough, Larry P.; Day, Warren C.

    2007-01-01

    The Black Mountain tectonic zone in the YukonTanana terrane of east-central Alaska is a belt of diverse northeast-trending geologic features that can been traced across Black Mountain in the southeast corner of the Big Delta 1°×3° degree quadrangle. Geologic mapping in the larger scale B1 quadrangle of the Big Delta quadrangle, in which Black Mountain is the principal physiographic feature, has revealed a continuous zone of normal and left-lateral strikeslip high-angle faults and shear zones, some of which have late Tertiary to Quaternary displacement histories. The tectonic zone includes complexly intruded wall rocks and intermingled apophyses of the contiguous mid-Cretaceous Goodpaster and Mount Harper granodioritic plutons, mafic to intermediate composite dike swarms, precious metal mineralization, early Tertiary volcanic activity and Quaternary fault scarps. These structures define a zone as much as 6 to 13 kilometers (km) wide and more than 40 km long that can be traced diagonally across the B1 quadrangle into the adjacent Eagle 1°×3° quadrangle to the east. Recurrent activity along the tectonic zone, from at least mid-Cretaceous to Quaternary, suggests the presence of a buried, fundamental tectonic feature beneath the zone that has influenced the tectonic development of this part of the Yukon-Tanana terrane. The tectonic zone, centered on Black Mountain, lies directly above a profound northeast-trending aeromagnetic anomaly between the Denali and Tintina fault systems. The anomaly separates moderate to strongly magnetic terrane on the northwest from a huge, weakly magnetic terrane on the southeast. The tectonic zone is parallel to the similarly oriented left-lateral, strike-slip Shaw Creek fault zone 85 km to the west.

  14. Stress, coping, and well-being among the Yup'ik of the Yukon-Kuskokwim Delta: the role of enculturation and acculturation.

    Science.gov (United States)

    Wolsko, Christopher; Lardon, Cécile; Mohatt, Gerald V; Orr, Eliza

    2007-02-01

    To report on the relationships between cultural identity and stress, coping, and psychological well-being in Yup'ik communities. A quantitative self-administered questionnaire. A health and wellness survey was completed by a total of 488 Yup'ik participants (284 women and 204 men) from 6 rural villages in the Yukon-Kuskokwim Delta region. Respondents were fairly equally distributed across an age range of 14 to 94 (mean +/- SD = 38.50 +/- 17.18). Participants who reported living more of a Kass'aq way of life (greater acculturation) reported experiencing greater psychosocial stress, less happiness, and greater use of drugs and alcohol to cope with stress. Participants who reported identifying more with a traditional Yup'ik way of life reported greater happiness, more frequent use of religion and spirituality to cope with stress, and less frequent use of drugs and alcohol to cope with stress. In conjunction with previous research, the data strongly indicates that in general, Yup'ik people in the Y-K Delta tend to associate stress and negative health outcomes with the process of acculturation, and health and healing with the process of enculturation. Research that focuses on documenting the intrinsic strengths of indigenous worldviews may contribute to positive transformations in community health.

  15. 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.

  16. Aerial surveys of endangered whales in the Alaskan Chukchi and western Beaufort Seas, 1990. Final report, Oct-Nov 90

    International Nuclear Information System (INIS)

    Moore, S.E.; Clarke, J.T.

    1991-06-01

    In keeping with the National Environmental Policy Act (1969), the Marine Mammal Protection Act (1972) and the Endangered Species Act (1973), the OCS Lands Act Amendments (1978) established a management policy that included studies in OCS lease sale areas to ascertain potential environmental impacts of oil and gas development on OCS marine coastal environments. The Minerals Management Service (MMS) is the agency responsible for these studies and for the leasing of submerged Federal lands. The report summarizes the 1990 investigations of the distribution, abundance, migration, behavior and habitat relationships of endangered whales in the Alaskan Chukchi and western Beaufort Seas (hereafter, study area); 1990 was the second of a three year (1989-91) study. The Bering Sea stock of bowhead whales (Balaena mysticetus) was the principal species studied, with incidental sightings of all other marine mammals routinely recorded. The 1990 season was compromised by circumstances that restricted the availability of the survey aircraft (Grumman Goose, model G21G) to the period 26 October - 7 November; opportunistic surveys were flown in the study area from 3-25 October. In 1990, there were 14 sightings of 19 bowheads from 9-29 October; 5 whales, including 2 calves, were seen north of the study area. One gray whale, 110 belukhas and 53 polar bears were also seen. Over nine survey seasons (1982-90), there were 240 sightings of 520 bowhead whales and 148 sightings of 398 gray whales

  17. 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.

  18. 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.

  19. Using the Environmental Intelligence Framework to Address Arctic Issues: A Case Study of Alaskan Fisheries and Ocean Acidification

    Science.gov (United States)

    Mathis, J. T.; Osborne, E.; Bamzai, A. S.; Starkweather, S.

    2017-12-01

    Profound environmental change in the Arctic region is driving an urgent need for faster and more efficient knowledge creation and delivery for residents of the Arctic as well as stakeholders around the globe. The overarching issues at play include environmental stewardship, community health and cultural survival. To effectively address these issues, the Interagency Arctic Research Policy Committee (IAPRC) recently established the Environmental Intelligence Collaboration Team (EICT) that integrates observing capabilities, modelling efforts and data management. Since its inception, the EICT has been working to create pathways to environmental knowledge that sustains end-to-end integration of research across the linked steps of data integration, environmental observing, predictive modelling, assessing responsiveness to stakeholder needs and ultimately providing decision support. The EICT is currently focusing on the carbon-climate aspect of environmental knowledge and identifing specific decision-making needs to meet policy goals for topics such as carbon emissions from permafrost thaw, increasing wildfire frequency and ocean acidification. As a case study, we applied the Environmental Intelligence framework to understanding the effects of ocean acidification in southern Alaska where there are critical commercial and subsistence fisheries. The results of this work revealed that there is currently a 5-month window of optimal growing conditions at a hatchery facility for many juvenile shellfish although that window is expected to close by 2040. The outcome of this work relates directly to fisheries management decisions and identifies the need for continued Environmental Intelligence collection to monitor and mitigate ocean acidification in the Alaskan region.

  20. 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 L.

    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.

  1. A new indicator mineral methodology based on a generic Bi-Pb-Te-S mineral inclusion signature in detrital gold from porphyry and low/intermediate sulfidation epithermal environments in Yukon Territory, Canada

    Science.gov (United States)

    Chapman, R. J.; Allan, M. M.; Mortensen, J. K.; Wrighton, T. M.; Grimshaw, M. R.

    2017-12-01

    Porphyry-epithermal and orogenic gold are two of the most important styles of gold-bearing mineralization within orogenic belts. Populations of detrital gold resulting from bulk erosion of such regions may exhibit a compositional continuum wherein Ag, Cu, and Hg in the gold alloy may vary across the full range exhibited by natural gold. This paper describes a new methodology whereby orogenic and porphyry-epithermal gold may be distinguished according to the mineralogy of microscopic inclusions observed within detrital gold particles. A total of 1459 gold grains from hypogene, eluvial, and placer environments around calc-alkaline porphyry deposits in Yukon (Nucleus-Revenue, Casino, Sonora Gulch, and Cyprus-Klaza) have been characterized in terms of their alloy compositions (Au, Ag, Cu, and Hg) and their inclusion mineralogy. Despite differences in the evolution of the different magmatic hydrothermal systems, the gold exhibits a clear Bi-Pb-Te-S mineralogy in the inclusion suite, a signature which is either extremely weak or (most commonly) absent in both Yukon orogenic gold and gold from orogenic settings worldwide. Generic systematic compositional changes in ore mineralogy previously identified across the porphyry-epithermal transition have been identified in the corresponding inclusion suites observed in samples from Yukon. However, the Bi-Te association repeatedly observed in gold from the porphyry mineralization persists into the epithermal environment. Ranges of P-T-X conditions are replicated in the geological environments which define generic styles of mineralization. These parameters influence both gold alloy composition and ore mineralogy, of which inclusion suites are a manifestation. Consequently, we propose that this methodology approach can underpin a widely applicable indicator methodology based on detrital gold.

  2. 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.

  3. Disparities in Prostate, Lung, Breast, and Colorectal Cancer Survival and Comorbidity Status among Urban American Indians and Alaskan Natives.

    Science.gov (United States)

    Emerson, Marc A; Banegas, Matthew P; Chawla, Neetu; Achacoso, Ninah; Alexeeff, Stacey E; Adams, Alyce S; Habel, Laurel A

    2017-12-01

    Cancer is the second leading cause of death among American Indians and Alaskan Natives (AIAN), although cancer survival information in this population is limited, particularly among urban AIAN. In this retrospective cohort study, we compared all-cause and prostate, breast, lung, and colorectal cancer-specific mortality among AIAN ( n = 582) and non-Hispanic white (NHW; n = 82,696) enrollees of Kaiser Permanente Northern California (KPNC) diagnosed with primary invasive breast, prostate, lung, or colorectal cancer from 1997 to 2015. Tumor registry and other electronic health records provided information on sociodemographic, comorbidity, tumor, clinical, and treatment characteristics. Cox regression models were used to estimate adjusted survival curves and hazard ratios (HR) with 95% confidence intervals (CI). AIAN had a significantly higher comorbidity burden compared with NHW ( P cancer-specific mortality were significantly higher for AIAN than NHW patients with breast cancer (HR, 1.47; 95% CI, 1.13-1.92) or with prostate cancer (HR, 1.87; 95% CI, 1.14-3.06) but not for AIAN patients with lung and colorectal cancer. Despite approximately equal access to preventive services and cancer care in this setting, we found higher mortality for AIAN than NHW with some cancers, and a greater proportion of AIAN cancer patients with multiple comorbid conditions. This study provides severely needed information on the cancer experience of the 71% of AIANs who live in urban areas and access cancer care outside of the Indian Health Services, from which the vast majority of AIAN cancer information comes. Cancer Res; 77(23); 6770-6. ©2017 AACR . ©2017 American Association for Cancer Research.

  4. Periodontal disease and its connection to systemic biomarkers of cardiovascular disease in young American Indian/Alaskan natives.

    Science.gov (United States)

    Delange, Nicole; Lindsay, Suzanne; Lemus, Hector; Finlayson, Tracy L; Kelley, Scott T; Gottlieb, Roberta A

    2018-02-01

    Periodontal disease has been shown to be associated with cardiovascular disease (CVD). No known studies evaluate the relationship between periodontal disease status and biomarkers of CVD risk in the American Indian/Alaskan Native (AI/AN) population despite their disproportionately high rates of poor oral health and cardiovascular disease-related outcomes. This study compared levels of interleukin (IL)-6 and C-reactive protein (CRP) across increasing severity of periodontal disease status among younger adults between the ages of 21 and 43 years. Plasma levels of IL-6 and CRP were measured in adult participants (ages 21 to 43 years) as part of a study of periodontal disease and CVD risk among an AI/AN population in southern California (n = 59). Periodontal evaluations were performed and disease status was classified into three categories based on highest probing depth (none/mild: disease or active infection were excluded. Severe periodontitis was significantly associated with increased levels of IL-6 compared with those with none or mild periodontitis before controlling for other variables (P = 0.02), but lacked significance after controlling for sex, BMI, smoking status, and high-density lipoprotein (P = 0.09). Moderate periodontal disease was positively associated with IL-6 levels after controlling for potential confounders (P = 0.01). Periodontal status was not associated with CRP, before or after adjusting for covariates. In this otherwise healthy AI/AN adult sample, moderate periodontal disease compared with none or mild periodontal disease was associated with increased levels of IL-6. High levels of CRP found in this population warrant further research. © 2018 American Academy of Periodontology.

  5. Characterizing wild bird contact and seropositivity to highly pathogenic avian influenza A (H5N1) virus in Alaskan residents.

    Science.gov (United States)

    Reed, Carrie; Bruden, Dana; Byrd, Kathy K; Veguilla, Vic; Bruce, Michael; Hurlburt, Debby; Wang, David; Holiday, Crystal; Hancock, Kathy; Ortiz, Justin R; Klejka, Joe; Katz, Jacqueline M; Uyeki, Timothy M

    2014-09-01

    Highly pathogenic avian influenza A (HPAI) H5N1 viruses have infected poultry and wild birds on three continents with more than 600 reported human cases (59% mortality) since 2003. Wild aquatic birds are the natural reservoir for avian influenza A viruses, and migratory birds have been documented with HPAI H5N1 virus infection. Since 2005, clade 2.2 HPAI H5N1 viruses have spread from Asia to many countries. We conducted a cross-sectional seroepidemiological survey in Anchorage and western Alaska to identify possible behaviors associated with migratory bird exposure and measure seropositivity to HPAI H5N1. We enrolled rural subsistence bird hunters and their families, urban sport hunters, wildlife biologists, and a comparison group without bird contact. We interviewed participants regarding their exposures to wild birds and collected blood to perform serologic testing for antibodies against a clade 2.2 HPAI H5N1 virus strain. Hunters and wildlife biologists reported exposures to wild migratory birds that may confer risk of infection with avian influenza A viruses, although none of the 916 participants had evidence of seropositivity to HPAI H5N1. We characterized wild bird contact among Alaskans and behaviors that may influence risk of infection with avian influenza A viruses. Such knowledge can inform surveillance and risk communication surrounding HPAI H5N1 and other influenza viruses in a population with exposure to wild birds at a crossroads of intercontinental migratory flyways. © 2014 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

  6. 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.

  7. Impacts of mean annual air temperature change on a regional permafrost probability model for the southern Yukon and northern British Columbia, Canada

    Directory of Open Access Journals (Sweden)

    P. P. Bonnaventure

    2013-06-01

    Full Text Available Air temperature changes were applied to a regional model of permafrost probability under equilibrium conditions for an area of nearly 0.5 × 106 km2 in the southern Yukon and northwestern British Columbia, Canada. Associated environmental changes, including snow cover and vegetation, were not considered in the modelling. Permafrost extent increases from 58% of the area (present day: 1971–2000 to 76% under a −1 K cooling scenario, whereas warming scenarios decrease the percentage of permafrost area exponentially to 38% (+ 1 K, 24% (+ 2 K, 17% (+ 3 K, 12% (+ 4 K and 9% (+ 5 K of the area. The morphology of permafrost gain/loss under these scenarios is controlled by the surface lapse rate (SLR, i.e. air temperature elevation gradient, which varies across the region below treeline. Areas that are maritime exhibit SLRs characteristically similar above and below treeline resulting in low probabilities of permafrost in valley bottoms. When warming scenarios are applied, a loss front moves to upper elevations (simple unidirectional spatial loss. Areas where SLRs are gently negative below treeline and normal above treeline exhibit a loss front moving up-mountain at different rates according to two separate SLRs (complex unidirectional spatial loss. Areas that display high continentally exhibit bidirectional spatial loss in which the loss front moves up-mountain above treeline and down-mountain below treeline. The parts of the region most affected by changes in MAAT (mean annual air temperature have SLRs close to 0 K km−1 and extensive discontinuous permafrost, whereas the least sensitive in terms of areal loss are sites above the treeline where permafrost presence is strongly elevation dependent.

  8. Trace-element geochemistry of metabasaltic rocks from the Yukon-Tanana Upland and implications for the origin of tectonic assemblages in east-central Alaska

    Science.gov (United States)

    Dusel-Bacon, C.; Cooper, K.M.

    1999-01-01

    We present major- and trace- element geochemical data for 27 amphibolites and six greenstones from three structural packages in the Yukon-Tanana Upland of east-central Alaska: the Lake George assemblage (LG) of Devono-Mississippian augen gneiss, quartz-mica schist, quartzite, and amphibolite; the Taylor Mountain assemblage (TM) of mafic schist and gneiss, marble, quartzite, and metachert; and the Seventymile terrane of greenstone, serpentinized peridotite, and Mississippian to Late Triassic metasedimentary rocks. Most LG amphibolites have relatively high Nb, TiO2, Zr, and light rare earth element contents, indicative of an alkalic to tholeiitic, within-plate basalt origin. The within-plate affinities of the LG amphibolites suggest that their basaltic parent magmas developed in an extensional setting and support a correlation of these metamorphosed continental-margin rocks with less metamorphosed counterparts across the Tintina fault in the Selwyn Basin of the Canadian Cordillera. TM amphibolites have a tholeiitic or calc-alkalic composition, low normalized abundances of Nb and Ta relative to Th and La, and Ti/V values of the proximity of the arc and marginal basin to continental crust. The arc geochemistry of TM amphibolites is consistent with a model in which the TM assemblage includes arc rocks generated above a west-dipping subduction zone outboard of the North American continental margin in mid-Paleozoic through Triassic time. The ocean-floor or within-plate basalt geochemistry of the Seventymile greenstones supports the correlation of the Seventymile terrane with the Slide Mountain terrane in Canada and the hypothesis that these oceanic rocks originated in a basin between the continental margin and an arc to the west.

  9. Assessing risk of mercury exposure and nutritional benefits of consumption of caribou (Rangifer tarandus) in the Vuntut Gwitchin First Nation community of Old Crow, Yukon, Canada.

    Science.gov (United States)

    Schuster, Roseanne C; Gamberg, Mary; Dickson, Cindy; Chan, Hing Man

    2011-08-01

    The contamination of traditional foods with chemical pollutants is a challenge to the food security of Aboriginal Peoples. Mercury levels are generally low in terrestrial animals; however renal mercury levels have been shown to change over time in the Porcupine Caribou Herd, the principal food source for the Vuntut Gwitchin First Nation of Old Crow in Yukon, Canada. Seventy-five Porcupine Caribou muscle, sixty-three kidney and three liver samples were analyzed for total mercury. Average concentrations were 0.003, 0.360 and 0.120mg/kg wet weight total mercury for muscle, kidney and liver, respectively. Consumption data of caribou muscle, kidney and liver were collected from twenty-six adults in Vuntut Gwitchin households. Women of child-bearing age (n=5) consumed a median of 71.5g/person/day of caribou muscle and 0.0g/person/day kidney but consumed no liver; median consumptions for all other adults (women aged 40+ and all men, n=21) were 75.8, 3.2 and 2.5g/person/day for meat, kidney and liver, respectively. Median dietary exposures to total mercury from caribou tissues were estimated to be 0.138μg/kg body weight for women of child-bearing age and 0.223μg/kg body weight for other adults. Caribou tissues were found to contribute high levels of important nutrients to the diet and pose minimal health risk from mercury exposure. Copyright © 2011 Elsevier Inc. All rights reserved.

  10. 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,...

  11. Flowing with Rivers

    Science.gov (United States)

    Anderson, Heather

    2004-01-01

    This article describes a lesson in which students compare how artists have depicted rivers in paintings, using different styles, compositions, subject matter, colors, and techniques. They create a watercolor landscape that includes a river. Students can learn about rivers by studying them on site, through environmental study, and through works of…

  12. Interdisciplinary approach to hydrological hazard mitigation and disaster response and effects of climate change on the occurrence of flood severity in central Alaska

    Science.gov (United States)

    Kontar, Y. Y.; Bhatt, U. S.; Lindsey, S. D.; Plumb, E. W.; Thoman, R. L.

    2015-06-01

    In May 2013, a massive ice jam on the Yukon River caused flooding that destroyed much of the infrastructure in the Interior Alaska village of Galena and forced the long-term evacuation of nearly 70% of its residents. This case study compares the communication efforts of the out-of-state emergency response agents with those of the Alaska River Watch program, a state-operated flood preparedness and community outreach initiative. For over 50 years, the River Watch program has been fostering long-lasting, open, and reciprocal communication with flood prone communities, as well as local emergency management and tribal officials. By taking into account cultural, ethnic, and socioeconomic features of rural Alaskan communities, the River Watch program was able to establish and maintain a sense of partnership and reliable communication patterns with communities at risk. As a result, officials and residents in these communities are open to information and guidance from the River Watch during the time of a flood, and thus are poised to take prompt actions. By informing communities of existing ice conditions and flood threats on a regular basis, the River Watch provides effective mitigation efforts in terms of ice jam flood effects reduction. Although other ice jam mitigation attempts had been made throughout US and Alaskan history, the majority proved to be futile and/or cost-ineffective. Galena, along with other rural riverine Alaskan communities, has to rely primarily on disaster response and recovery strategies to withstand the shock of disasters. Significant government funds are spent on these challenging efforts and these expenses might be reduced through an improved understanding of both the physical and climatological principals behind river ice breakup and risk mitigation. This study finds that long term dialogue is critical for effective disaster response and recovery during extreme hydrological events connected to changing climate, timing of river ice breakup, and

  13. Interdisciplinary approach to hydrological hazard mitigation and disaster response and effects of climate change on the occurrence of flood severity in central Alaska

    Directory of Open Access Journals (Sweden)

    Y. Y. Kontar

    2015-06-01

    Full Text Available In May 2013, a massive ice jam on the Yukon River caused flooding that destroyed much of the infrastructure in the Interior Alaska village of Galena and forced the long-term evacuation of nearly 70% of its residents. This case study compares the communication efforts of the out-of-state emergency response agents with those of the Alaska River Watch program, a state-operated flood preparedness and community outreach initiative. For over 50 years, the River Watch program has been fostering long-lasting, open, and reciprocal communication with flood prone communities, as well as local emergency management and tribal officials. By taking into account cultural, ethnic, and socioeconomic features of rural Alaskan communities, the River Watch program was able to establish and maintain a sense of partnership and reliable communication patterns with communities at risk. As a result, officials and residents in these communities are open to information and guidance from the River Watch during the time of a flood, and thus are poised to take prompt actions. By informing communities of existing ice conditions and flood threats on a regular basis, the River Watch provides effective mitigation efforts in terms of ice jam flood effects reduction. Although other ice jam mitigation attempts had been made throughout US and Alaskan history, the majority proved to be futile and/or cost-ineffective. Galena, along with other rural riverine Alaskan communities, has to rely primarily on disaster response and recovery strategies to withstand the shock of disasters. Significant government funds are spent on these challenging efforts and these expenses might be reduced through an improved understanding of both the physical and climatological principals behind river ice breakup and risk mitigation. This study finds that long term dialogue is critical for effective disaster response and recovery during extreme hydrological events connected to changing climate, timing of

  14. Building research capacity with members of underserved American Indian/Alaskan Native communities: training in research ethics and the protection of human subjects.

    Science.gov (United States)

    Jetter, Karen M; Yarborough, Mark; Cassady, Diana L; Styne, Dennis M

    2015-05-01

    To develop a research ethics training course for American Indian/Alaskan Native health clinic staff and community researchers who would be conducting human subjects research. Community-based participatory research methods were used in facilitated discussions of research ethics centered around topics included in the Collaborative Institutional Training Initiative research ethics course. The community-based participatory research approach allowed all partners to jointly develop a research ethics training program that was relevant for American Indian/Alaskan Native communities. All community and clinic partners were able to pass the Collaborative Institutional Training Initiative course they were required to pass so that they could be certified to conduct research with human subjects on federally funded projects. In addition, the training sessions provided a foundation for increased community oversight of research. By using a collaborative process to engage community partners in research ethics discussions, rather than either an asynchronous online or a lecture/presentation format, resulted in significant mutual learning about research ethics and community concerns about research. This approach requires university researchers to invest time in learning about the communities in which they will be working prior to the training. © 2014 Society for Public Health Education.

  15. River basin administration

    Science.gov (United States)

    Management of international rivers and their basins is the focus of the Centre for Comparative Studies on (International) River Basin Administration, recently established at Delft University of Technology in the Netherlands. Water pollution, sludge, and conflicting interests in the use of water in upstream and downstream parts of a river basin will be addressed by studying groundwater and consumption of water in the whole catchment area of a river.Important aspects of river management are administrative and policy aspects. The Centre will focus on policy, law, planning, and organization, including transboundary cooperation, posing standards, integrated environmental planning on regional scale and environmental impact assessments.

  16. Sources and Reactivity of Terrestrial Organic Carbon to the Colville River Delta, Beaufort Sea, Alaska

    Science.gov (United States)

    Schreiner, K. M.; Bianchi, T. S.; Rosenheim, B. E.

    2014-12-01

    Terrestrial particulate organic carbon (tPOC) delivery to nearshore deltaic regions is an important mechanism of OC storage and burial, and continental margins worldwide account for approximately 90% of the carbon burial in the ocean. Increasing warming in the Arctic is leading to an acceleration of the hydrologic cycle, warming of permafrost, and broad shifts in vegetation. All of these changes are likely to affect the delivery, reactivity, and burial of tPOC in nearshore Arctic regions, making the Arctic an ideal place to study the effects of climate change on tPOC delivery. However, to date, most studies of tPOC delivery from North America to the Arctic Ocean have focused on large Arctic rivers like the Mackenzie and Yukon, and a significant portion of those watersheds lie in sub-Arctic latitudes, meaning that their tPOC delivery is likely not uniquely representative of the high Arctic tundra. Here, we focus on tPOC delivery by the Colville River, the largest North American river with a watershed that does not include sub-Arctic latitudes. Sediment samples from the river delta and nearby Simpson's Lagoon were taken in August of 2010 and subsequently fractionated by density, in order to study the delivery of both discrete and sediment-sorbed tPOC. Samples were analyzed for stable carbon isotopes, bulk radiocarbon, terrestrial biomarkers (including lignin-phenols, and other CuO reaction products), and aquatic biomarkers (algal pigments), and additionally a subset of the samples were analyzed by ramped pyrolysis-14C. Results show that tPOC delivery near the river mouth is sourced from coastal plain tundra, with additional delivery of tPOC from peat released into the lagoon from the seaward limit of the tundra by coastal erosion. Ramped pyrolysis-14C analysis also shows a clear differentiation between tPOC delivered by the river and tPOC delivered by coastal retreat in the lagoon. Additionally, a significant portion of the OC released by the Colville River is

  17. Comparison of snow melt properties across multiple spatial scales and landscape units in interior sub-Arctic boreal Alaskan watersheds

    Science.gov (United States)

    Bennett, K. E.; Cherry, J. E.; Hiemstra, C. A.; Bolton, W. R.

    2013-12-01

    Interior sub-Arctic Alaskan snow cover is rapidly changing and requires further study for correct parameterization in physically based models. This project undertook field studies during the 2013 snow melt season to capture snow depth, snow temperature profiles, and snow cover extent to compare with observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor at four different sites underlain by discontinuous permafrost. The 2013 melt season, which turned out to be the latest snow melt period on record, was monitored using manual field measurements (SWE, snow depth data collection), iButtons to record temperature of the snow pack, GoPro cameras to capture time lapse of the snow melt, and low level orthoimagery collected at ~1500 m using a Navion L17a plane mounted with a Nikon D3s camera. Sites were selected across a range of landscape conditions, including a north facing black spruce hill slope, a south facing birch forest, an open tundra site, and a high alpine meadow. Initial results from the adjacent north and south facing sites indicate a highly sensitive system where snow cover melts over just a few days, illustrating the importance of high resolution temporal data capture at these locations. Field observations, iButtons and GoPro cameras show that the MODIS data captures the melt conditions at the south and the north site with accuracy (2.5% and 6.5% snow cover fraction present on date of melt, respectively), but MODIS data for the north site is less variable around the melt period, owing to open conditions and sparse tree cover. However, due to the rapid melt rate trajectory, shifting the melt date estimate by a day results in a doubling of the snow cover fraction estimate observed by MODIS. This information can assist in approximating uncertainty associated with remote sensing data that is being used to populate hydrologic and snow models (the Sacramento Soil Moisture Accounting model, coupled with SNOW-17, and the Variable

  18. Impacts of climate and insect defoliators on productivity and function of trembling aspen (Populus tremuloides) in Alaskan boreal forests

    Science.gov (United States)

    Boyd, M. A.; Walker, X. J.; Rogers, B. M.; Goetz, S. J.; Wagner, D.; Mack, M. C.

    2017-12-01

    Climate change has increased tree mortality and growth decline in forested ecosystems worldwide. In response to warming and drying of the boreal forest, trembling aspen (Populus tremuloides) has experienced recent large-scale productivity declines. Although declines in productivity are thought to be primarily a result of moistures stress, infestation is another major driver of aspen decline and may interact strongly with climate. Throughout interior Alaska widespread and consistent foliar damage by the aspen epidermal leaf miner Phyllocnistis populiella has been observed concurrent with some of the warmest and driest growing seasons on record. Here we use tree ring measurements and remote sensing indices of vegetation productivity (NDVI) to study the influence of leaf miner and climate on aspen productivity and physiology in the Alaskan boreal forest, and assess if NDVI reflects variations in these ground-based measurements. We assessed ring width and tree ring stable carbon isotope (d13C) response of aspen to infestation and a climate moisture index (CMI) from 2004 - 2014. We found that when growth was negatively correlated to infestation, then it was no longer positively influenced by moisture availability during the growing season. Regardless of the radial growth response to leaf mining, tree ring d13C decreased with increasing infestation. We also found that NDVI was influenced by leaf mining and showed a positive correlation with tree ring d13C, which suggests that NDVI is reflective of changes in tree characteristics under leaf mining that influence tree ring d13C. This finding also reveals the prospect of using satellite data to monitor fluctuations in tree physiology during leaf miner infestation. Our results indicate that aspen productivity will be severely hindered during leaf miner infestation, and that infestation will inhibit the ability of aspen to respond to favorable climate conditions by increasing growth and potentially photosynthesis. This

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

    International Nuclear Information System (INIS)

    Ryan, M.J.; Stern, G.A.; Kidd, K.A.; Croft, M.V.; Gewurtz, S.; Diamond, M.; Kinnear, L.; Roach, P.

    2013-01-01

    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 13 C, δ 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

  20. 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

  1. Nitrogen and carbon isotopic dynamics of subarctic soils and plants in southern Yukon Territory and its implications for paleoecological and paleodietary studies

    Science.gov (United States)

    Longstaffe, Fred J.; Zazula, Grant; Bennett, Bruce

    2017-01-01

    We examine here the carbon and nitrogen isotopic compositions of bulk soils (8 topsoil and 7 subsoils, including two soil profiles) and five different plant parts of 79 C3 plants from two main functional groups: herbs and shrubs/subshrubs, from 18 different locations in grasslands of southern Yukon Territory, Canada (eastern shoreline of Kluane Lake and Whitehorse area). The Kluane Lake region in particular has been identified previously as an analogue for Late Pleistocene eastern Beringia. All topsoils have higher average total nitrogen δ15N and organic carbon δ13C than plants from the same sites with a positive shift occurring with depth in two soil profiles analyzed. All plants analyzed have an average whole plant δ13C of −27.5 ± 1.2 ‰ and foliar δ13C of –28.0 ± 1.3 ‰, and average whole plant δ15N of −0.3 ± 2.2 ‰ and foliar δ15N of –0.6 ± 2.7 ‰. Plants analyzed here showed relatively smaller variability in δ13C than δ15N. Their average δ13C after suitable corrections for the Suess effect should be suitable as baseline for interpreting diets of Late Pleistocene herbivores that lived in eastern Beringia. Water availability, nitrogen availability, spacial differences and intra-plant variability are important controls on δ15N of herbaceous plants in the study area. The wider range of δ15N, the more numerous factors that affect nitrogen isotopic composition and their likely differences in the past, however, limit use of the modern N isotopic baseline for vegetation in paleodietary models for such ecosystems. That said, the positive correlation between foliar δ15N and N content shown for the modern plants could support use of plant δ15N as an index for plant N content and therefore forage quality. The modern N isotopic baseline cannot be applied directly to the past, but it is prerequisite to future efforts to detect shifts in N cycling and forage quality since the Late Pleistocene through comparison with fossil plants from the same

  2. Nitrogen and carbon isotopic dynamics of subarctic soils and plants in southern Yukon Territory and its implications for paleoecological and paleodietary studies.

    Directory of Open Access Journals (Sweden)

    Farnoush Tahmasebi

    Full Text Available We examine here the carbon and nitrogen isotopic compositions of bulk soils (8 topsoil and 7 subsoils, including two soil profiles and five different plant parts of 79 C3 plants from two main functional groups: herbs and shrubs/subshrubs, from 18 different locations in grasslands of southern Yukon Territory, Canada (eastern shoreline of Kluane Lake and Whitehorse area. The Kluane Lake region in particular has been identified previously as an analogue for Late Pleistocene eastern Beringia. All topsoils have higher average total nitrogen δ15N and organic carbon δ13C than plants from the same sites with a positive shift occurring with depth in two soil profiles analyzed. All plants analyzed have an average whole plant δ13C of -27.5 ± 1.2 ‰ and foliar δ13C of -28.0 ± 1.3 ‰, and average whole plant δ15N of -0.3 ± 2.2 ‰ and foliar δ15N of -0.6 ± 2.7 ‰. Plants analyzed here showed relatively smaller variability in δ13C than δ15N. Their average δ13C after suitable corrections for the Suess effect should be suitable as baseline for interpreting diets of Late Pleistocene herbivores that lived in eastern Beringia. Water availability, nitrogen availability, spacial differences and intra-plant variability are important controls on δ15N of herbaceous plants in the study area. The wider range of δ15N, the more numerous factors that affect nitrogen isotopic composition and their likely differences in the past, however, limit use of the modern N isotopic baseline for vegetation in paleodietary models for such ecosystems. That said, the positive correlation between foliar δ15N and N content shown for the modern plants could support use of plant δ15N as an index for plant N content and therefore forage quality. The modern N isotopic baseline cannot be applied directly to the past, but it is prerequisite to future efforts to detect shifts in N cycling and forage quality since the Late Pleistocene through comparison with fossil plants from

  3. Operation of river systems. The Otra river

    International Nuclear Information System (INIS)

    Harby, A.; Vaskinn, K.A.; Wathne, M.; Heggenes, J.; Saltveit, S.J.

    1993-12-01

    The purpose of the project described in this report was to prepare an operative tool for making decisions about the operation of the power system on the river Otra (Norway) with regard to how this operation might affect the various users of the river system. Above all this affects fish, outdoor life and esthetic values. The connection between water quality and volume of discharge has been examined in a sub project. How suitable parts of the river are as habitats for trout has been simulated on a computer. From field investigation it is concluded that near the Steinfoss power station the physical conditions for trout depend on the operation of the river system. Outdoor life is not much affected downstream Vikeland. 11 refs., 22 figs., 2 tabs

  4. 76 FR 51887 - Safety Zone; Patuxent River, Patuxent River, MD

    Science.gov (United States)

    2011-08-19

    ...-AA00 Safety Zone; Patuxent River, Patuxent River, MD AGENCY: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY: The Coast Guard is establishing a temporary safety zone during the ``NAS Patuxent River... held over certain waters of the Patuxent River adjacent to Patuxent River, Maryland from September 1...

  5. Hydrology of the North Klondike River: carbon export, water balance and inter-annual climate influences within a sub-alpine permafrost catchment.

    Science.gov (United States)

    Lapp, Anthony; Clark, Ian; Macumber, Andrew; Patterson, Tim

    2017-10-01

    Arctic and sub-arctic watersheds are undergoing significant changes due to recent climate warming and degrading permafrost, engendering enhanced monitoring of arctic rivers. Smaller catchments provide understanding of discharge, solute flux and groundwater recharge at the process level that contributes to an understanding of how larger arctic watersheds are responding to climate change. The North Klondike River, located in west central Yukon, is a sub-alpine permafrost catchment, which maintains an active hydrological monitoring station with a record of >40 years. In addition to being able to monitor intra-annual variability, this data set allows for more complex analysis of streamflow records. Streamflow data, geochemistry and stable isotope data for 2014 show a groundwater-dominated system, predominantly recharged during periods of snowmelt. Radiocarbon is shown to be a valuable tracer of soil zone recharge processes and carbon sources. Winter groundwater baseflow contributes 20 % of total annual discharge, and accounts for up to 50 % of total river discharge during the spring and summer months. Although total stream discharge remains unchanged, mean annual groundwater baseflow has increased over the 40-year monitoring period. Wavelet analysis reveals a catchment that responds to El Niño and longer solar cycles, as well as climatic shifts such as the Pacific Decadal Oscillation. Dedicated to Professor Peter Fritz on the occasion of his 80th birthday.

  6. 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 the persp......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...

  7. 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

  8. 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.

  9. 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...

  10. Processes Influencing Ozone Levels in Alaskan Forest Fires Plumes during Long-Range Transport over the North Atlantic

    Science.gov (United States)

    Real, E.; Law, K. S.; Wienzierl, B.; Fiebig, M.; Petzold, A.; Wild, O.; Methven, J.; Arnold, S.; Stohl, A.; Huntrieser, H.; hide

    2006-01-01

    well reproduced by multiple model runs even if slope values are slightly underestimated suggesting small underestimation of photochemical processes. The possible impact of this biomass burning plume on O3 levels in the Europe boundary layer is also examined by running the model for a further 5 days, and comparing with data collected at surface sites, such as Jungfraujoch, which showed small O3 increases and elevated CO levels. The model predicts significant changes in O3 over this 10 days due to photochemistry but the signal is largely lost due to the effects of dilution. However, measurement in several others BB plumes over Europe show that O3 impact of Alaskan fires can be punctually significant over Europe.

  11. 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

  12. Environmental Impact Analysis Process. Draft Environmental Impact Statement Proposed Alaskan Radar System Over-the-Horizon Backscatter Radar Program

    Science.gov (United States)

    1986-08-01

    Mustela vison wolverine Gulo Kulo river otter Lutra canadensis lynx Lynx canadensis moose Alces alces caribou Rangifer tarandus Dall’s sheep Ovic dalli...tissue respiratory chain function at a power density of 5 mW/cm2 . It is unlikely that such effects would be detectable at the power densities at ground...Vulves vulpes black bear Ursus americanus grizzly bear Ursus arctos marten Martes americana ermine Mustela erminea least weasel Mustela nivalis mink

  13. Preserving the Dnipro River

    International Development Research Centre (IDRC) Digital Library (Canada)

    Humanity inherited the true sense of proportion, synergy, and harmony from the natural environment. ..... In Ukraine, the middle and lower sections of the Dnipro have a drainage ... The following large cities are located in the Dnipro basin: in Russia, .... In Kherson Oblast and in river basins of some small rivers it is as high as ...

  14. Estimation of Acoustic Particle Motion and Source Bearing Using a Drifting Hydrophone Array Near a River Current Turbine to Assess Disturbances to Fish

    Science.gov (United States)

    Murphy, Paul G.

    River hydrokinetic turbines may be an economical alternative to traditional energy sources for small communities on Alaskan rivers. However, there is concern that sound from these turbines could affect sockeye salmon (Oncorhynchus nerka), an important resource for small, subsistence based communities, commercial fisherman, and recreational anglers. The hearing sensitivity of sockeye salmon has not been quantified, but behavioral responses to sounds at frequencies less than a few hundred Hertz have been documented for Atlantic salmon (Salmo salar), and particle motion is thought to be the primary mode of stimulation. Methods of measuring acoustic particle motion are well-established, but have rarely been necessary in energetic areas, such as river and tidal current environments. In this study, the acoustic pressure in the vicinity of an operating river current turbine is measured using a freely drifting hydrophone array. Analysis of turbine sound reveals tones that vary in frequency and magnitude with turbine rotation rate, and that may sockeye salmon may sense. In addition to pressure, the vertical components of particle acceleration and velocity are estimated by calculating the finite difference of the pressure signals from the hydrophone array. A method of determining source bearing using an array of hydrophones is explored. The benefits and challenges of deploying drifting hydrophone arrays for marine renewable energy converter monitoring are discussed.

  15. Numerical modelling of river processes: flow and river bed deformation

    NARCIS (Netherlands)

    Tassi, P.A.

    2007-01-01

    The morphology of alluvial river channels is a consequence of complex interaction among a number of constituent physical processes, such as flow, sediment transport and river bed deformation. This is, an alluvial river channel is formed from its own sediment. From time to time, alluvial river

  16. Uranium in river water

    International Nuclear Information System (INIS)

    Palmer, M.R.; Edmond, J.M.

    1993-01-01

    The concentration of dissolved uranium has been determined in over 250 river waters from the Orinoco, Amazon, and Ganges basins. Uranium concentrations are largely determined by dissolution of limestones, although weathering of black shales represents an important additional source in some basins. In shield terrains the level of dissolved U is transport limited. Data from the Amazon indicate that floodplains do not represent a significant source of U in river waters. In addition, the authors have determined dissolved U levels in forty rivers from around the world and coupled these data with previous measurements to obtain an estimate for the global flux of dissolved U to the oceans. The average concentration of U in river waters is 1.3 nmol/kg, but this value is biased by very high levels observed in the Ganges-Brahmaputra and Yellow rivers. When these river systems are excluded from the budget, the global average falls to 0.78 nmol/kg. The global riverine U flux lies in the range of 3-6 x 10 7 mol/yr. The major uncertainty that restricts the accuracy of this estimate (and that of all other dissolved riverine fluxes) is the difficulty in obtaining representative samples from rivers which show large seasonal and annual variations in runoff and dissolved load

  17. Savannah River Plant environment

    International Nuclear Information System (INIS)

    Dukes, E.K.

    1984-03-01

    On June 20, 1972, the Atomic Energy Commission designated 192,323 acres of land near Aiken, SC, as the nation's first National Environmental Research Park. The designated land surrounds the Department of Energy's Savannah River Plant production complex. The site, which borders the Savannah River for 17 miles, includes swampland, pine forests, abandoned town sites, a large man-made lake for cooling water impoundment, fields, streams, and watersheds. This report is a description of the geological, hydrological, meteorological, and biological characteristics of the Savannah River Plant site and is intended as a source of information for those interested in environmental research at the site. 165 references, 68 figures, 52 tables

  18. 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.

  19. Hunting camp. River Murray

    OpenAIRE

    ? Bayliss, Charles, 1850-1897, photographer

    2003-01-01

    200 x 149 mm. A good photograph showing a group of aborigines (in European clothes) with two hunting dogs, holding spears and standing in front of rough wooden cabins; with the river in the background. Photograph unknown, possible Charles Bayliss.

  20. 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...

  1. Uranium concentrations in lake and stream waters and sediments from selected sites in the Susitna River Basin, Alaska

    International Nuclear Information System (INIS)

    Hill, D.E.

    1977-03-01

    During the summer of 1976, 141 water and 211 sediment samples were taken from 147 locations in the Susitna River basin in Alaska by the Geophysical Institute of the University of Alaska for the LASL. These samples were taken to provide preliminary information on the uranium concentrations in waters and sediments from the Susitna River basin and to test the analytical methods proposed for the NURE Hydrogeochemical and Stream Sediment Reconnaissance for uranium in Alaska. The uranium determinations resulting from the fluorometric analysis of the water samples and the delayed-neutron counting of the sediment samples are presented. The low levels of uranium in the water samples, many of which were below the detectable limit of the LASL fluorometric technique, indicate that a more sensitive analytical method is needed for the analysis of Alaskan water samples from this area. An overlay showing numbered sample locations and overlays graphically portraying the concentrations of uranium in the water and sediment samples, all at 1:250,000 scale for use with existing USGS topographic sheets, are also provided as plates

  2. [Health assessment of river ecosystem in Haihe River Basin, China].

    Science.gov (United States)

    Hao, Li-Xia; Sun, Ran-Hao; Chen, Li-Ding

    2014-10-01

    With the development of economy, the health of river ecosystem is severely threatened because of the increasing effects of human activities on river ecosystem. In this paper, the authors assessed the river ecosystem health in aspects of chemical integrity and biological integrity, using the criterion in water quality, nutrient, and benthic macroinvertebrates of 73 samples in Haihe River Basin. The research showed that the health condition of river ecosystem in Haihe River Basin was bad overall since the health situation of 72. 6% of the samples was "extremely bad". At the same time, the health situation in Haihe River Basin exhibited obvious regional gathering effect. We also found that the river water quality was closely related to human activities, and the eutrophication trend of water body was evident in Haihe River Basin. The biodiversity of the benthic animal was low and lack of clean species in the basin. The indicators such as ammonia nitrogen, total nitrogen and total phosphorus were the key factors that affected the river ecosystem health in Haihe River Basin, so the government should start to curb the deterioration of river ecosystem health by controlling these nutrients indicators. For river ecosystem health assessment, the multi-factors comprehensive evaluation method was superior to single-factor method.

  3. Endometrial cancer in Asian and American Indian/Alaskan Native women: tumor characteristics, treatment and outcome compared to non-Hispanic white women.

    Science.gov (United States)

    Mahdi, Haider; Schlick, Cary Jo; Kowk, Li-Lian; Moslemi-Kebria, Mehdi; Michener, Chad

    2014-02-01

    The objective of this study is to compare survival of Asian (AS), American Indian/Alaskan Native (AI/AN) and non-Hispanic white (NHW) women with endometrial adenocarcinoma (EC). Patients with EC were identified from the Surveillance, Epidemiology, and End Results program from 1988 to 2009. Kaplan-Meier survival methods and Cox proportional hazards regression were performed. Of the 105,083 women, 97,763 (93%) were NHW, 6699 (6.4%) were AS and 621 (0.6%) were AI/AN. AS and AI/AN were younger than NHW with mean age of 57.7 and 56.5 vs. 64.3 years (p Asian immigrants were younger than Asian natives (mean age 57 vs. 60.5 years, p Asian immigrants had better OS (HR 0.83, 95% CI 0.73-0.94, p = 0.002) and CSS (HR 0.66, 95% CI 0.54-0.80, p Asian natives. In contrast, AI/AN had worse OS (HR 1.35, 95% CI 1.15-1.59, p Asians were younger at presentation, more likely to have lymphadenectomy and had an improved outcome compared to NHW. Interestingly, Asian immigrants had more favorable outcome than Asians born in the US. Further studies are warranted to find possible explanations for such a difference. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Sulfate reduction and methane oxidation activity below the sulfate-methane transition zone in Alaskan Beaufort Sea continental margin sediments: Implications for deep sulfur cycling

    Science.gov (United States)

    Treude, Tina; Krause, Stefan; Maltby, Johanna; Dale, Andrew W.; Coffin, Richard; Hamdan, Leila J.

    2014-11-01

    Two ∼6 m long sediment cores were collected along the ∼300 m isobath on the Alaskan Beaufort Sea continental margin. Both cores showed distinct sulfate-methane transition zones (SMTZ) at 105 and 120 cm below seafloor (cmbsf). Sulfate was not completely depleted below the SMTZ but remained between 30 and 500 μM. Sulfate reduction and anaerobic oxidation of methane (AOM) determined by radiotracer incubations were active throughout the methanogenic zone. Although a mass balance could not explain the source of sulfate below the SMTZ, geochemical profiles and correlation network analyses of biotic and abiotic data suggest a cryptic sulfur cycle involving iron, manganese and barite. Inhibition experiments with molybdate and 2-bromoethanesulfonate (BES) indicated decoupling of sulfate reduction and AOM and competition between sulfate reducers and methanogens for substrates. While correlation network analyses predicted coupling of AOM to iron reduction, the addition of manganese or iron did not stimulate AOM. Since none of the classical archaeal anaerobic methanotrophs (ANME) were abundant, the involvement of unknown or unconventional phylotypes in AOM is conceivable. The resistance of AOM activity to inhibitors implies deviation from conventional enzymatic pathways. This work suggests that the classical redox cascade of electron acceptor utilization based on Gibbs energy yields does not always hold in diffusion-dominated systems, and instead biotic processes may be more strongly coupled to mineralogy.

  5. 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.

  6. Challenges to recruit and retain American Indian and Alaskan Natives into social work programs: the impact on the child welfare workforce.

    Science.gov (United States)

    Cross, Suzanne L; Day, Angelique; Gogliotti, Lucas J; Pung, Justin J

    2013-01-01

    There is a shortage of professionally trained American Indian/Alaskan Native (AI/AN) social workers available to provide services including child welfare services to tribal communities. This study used a mixed-model survey design to examine the perceptions of 47 AI/AN BSW and MSW students enrolled in social work programs across the to determine the challenges associated with recruitment and retention. The findings are supported in the literature. Findings indicate that social work academic programs have not made substantial gains in the recruitment and retention of AI/AN students over several decades. Students identified the following seven major barriers to successful recruitment and retention: (1) a lack of AI/AN professors; (2) a shortage of field placement agencies that serve AI/AN clients; (3) conflicts between students' academic obligations and responsibilities to their families and tribal communities; (4) students' feelings of cultural isolation; (5) the need for AI/AN role models and mentors; (6) a lack of understanding by universities of cultural customs and traditional values; and (7) racism. Implications for policy and practice are offered.

  7. "I get by with a little help from my friends": A case study in Holy Cross and Grayling using geographic, ethnographic, and biophysical data to tell the story of climate change effects in the lower-middle Yukon River region

    Science.gov (United States)

    Hollingsworth, T. N.; Brown, C.; Cold, H.; Brinkman, T. J.; Brown, D. N.; Verbyla, D.

    2017-12-01

    Over the last century, Alaska has warmed more than twice as rapidly as the contiguous US. Climate change in boreal Alaska has created new and undocumented vulnerabilities for rural communities. In rural areas, subsistence harvesters rely on established travel networks to access traditional hunting, fishing, and gathering areas. These routes are being affected by ecosystem disturbances, such as thermokarst and increased wildfire severity, linked to climate change. Understanding these changes requires a collaborative effort, using many different forms of data to tell a complete story. Here, we present a case study from Holy Cross and Grayling, Alaska to demonstrate the importance of cross-discipline data integration. Local subsistence users documented GPS coordinates of encountered sites of ecosystem disturbances influencing their access to subsistence areas. These knowledge holders provided the ethnographic, historical and experiential descriptions of the effects of these changes. Then, remote-sensing imagery allows us to look at how these sites change over time. Finally, we returned to collaborate with subsistence users to visit specific sites and quantify the biophysical mechanisms that describe these disturbances. In Holy Cross, we visited areas that recently burned and are undergoing rapid changes in vegetation. We describe the fire regime characteristics such as fire severity, age of site when it burned, pre-fire composition, and post-fire successional trajectory. In Grayling, we visited areas with drying water bodies and associated vegetation change. We describe the current vegetation structure and composition, looked at potential shifts in soil moisture and used repeat imagery to quantify change in water. Our case study exemplifies the power of participatory research, collaboration, and a cross-disciplinary methodology to expand our collective understanding of landscape-level climate-related changes in boreal Alaska.

  8. 33 CFR 117.734 - Navesink River (Swimming River).

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Navesink River (Swimming River). 117.734 Section 117.734 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... (Swimming River). The Oceanic Bridge, mile 4.5, shall open on signal; except that, from December 1 through...

  9. Skjern River Restoration Counterfactual

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel

    2014-01-01

    In 2003 the Skjern River Restoration Project in Denmark was awarded the prestigious Europa Nostra Prize for ‘conserving the European cultural heritage’ (Danish Nature Agency 2005). In this case, however, it seems that the conservation of one cultural heritage came at the expense of another cultural...... this massive reconstruction work, which involved moving more than 2,7 million cubic meters of earth, cause a lot of ‘dissonance’ among the local population, the resulting ‘nature’ and its dynamic processes are also constantly compromising the preferred image of the restored landscape (Clemmensen 2014......). The presentation offers insight into an on-going research and development project - Skjern River Restoration Counterfactual, which question existing trends and logics within nature restoration. The project explores how the Skjern River Delta could have been ‘restored’ with a greater sensibility for its cultural...

  10. 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...

  11. Haw River PFCs Data Set

    Data.gov (United States)

    U.S. Environmental Protection Agency — PFAS concentrations in river and drinking water in and around the Haw River in North Carolina. This dataset is associated with the following publication: Sun, M., E....

  12. 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 for ...... for river geometries are formulated and a coupling between hydraulic computational methods and numerical reliability methods is presented....

  13. 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.

    2017-01-01

    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

  14. Geomorphic classification of rivers

    Science.gov (United States)

    J. M. Buffington; D. R. Montgomery

    2013-01-01

    Over the last several decades, environmental legislation and a growing awareness of historical human disturbance to rivers worldwide (Schumm, 1977; Collins et al., 2003; Surian and Rinaldi, 2003; Nilsson et al., 2005; Chin, 2006; Walter and Merritts, 2008) have fostered unprecedented collaboration among scientists, land managers, and stakeholders to better understand,...

  15. Savannah River Technology Center

    International Nuclear Information System (INIS)

    1993-01-01

    This is a monthly progress report from the Savannah River Laboratory for the month of January 1993. It has sections with work in the areas of reactor safety, tritium processes and absorption, separations programs and wastes, environmental concerns and responses, waste management practices, and general concerns

  16. Alligator Rivers Region

    International Nuclear Information System (INIS)

    1992-01-01

    An introduction to the Alligator Rivers Region is presented. It contains general information regarding the physiography, climate, hydrology and mining of the region. The Alligator Rivers Region is within an ancient basin, the Pine Creek Geosyncline, which has an area of approximately 66000 km 2 . The Geosyncline has a history of mineral exploitation dating back to 1865, during which time 16 metals have been extracted (silver, arsenic, gold, bismuth, cadmium, cobalt, copper, iron, manganese, molybdenum, lead, tin, tantalum, uranium, tungsten, zinc). Uranium exploration in the Pine Creek Geosyncline was stimulated by the discovery in 1949 of secondary uranium mineralisation near Rum June, 70 km south-east of Darwin. This was followed by a decade of intense exploration activity resulting in the discoveries of economic uranium ore bodies at Rum Jungle and in the upper reaches of the South Alligator River Valley. All the known major uranium deposits of the East Alligator River uranium field have been discovered since 1969. The present known resources of the Geosyncline are approximately 360 000 tonnes of contained U 3 O 8 . 2 refs., 2 figs., 1 tab

  17. Discover the Nile River

    Science.gov (United States)

    Project WET Foundation, 2009

    2009-01-01

    Bordering on the Fantastic. As the longest river on earth, the Nile passes through 10 countries. Presented through a wide range of activities and a winning array of games, it's also unsurpassed at taking young minds into exploring the world of water, as well as natural and man made wonders.

  18. 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...

  19. A reassessment of North American river basin water balances in light of new estimates of mountain snow accumulation

    Science.gov (United States)

    Wrzesien, M.; Durand, M. T.; Pavelsky, T.

    2017-12-01

    The hydrologic cycle is a key component of many aspects of daily life, yet not all water cycle processes are fully understood. In particular, water storage in mountain snowpacks remains largely unknown. Previous work with a high resolution regional climate model suggests that global and continental models underestimate mountain snow accumulation, perhaps by as much as 50%. Therefore, we hypothesize that since snow water equivalent (one aspect of the water balance) is underestimated, accepted water balances for major river basins are likely wrong, particularly for mountainous river basins. Here we examine water balances for four major high latitude North American watersheds - the Columbia, Mackenzie, Nelson, and Yukon. The mountainous percentage of each basin ranges, which allows us to consider whether a bias in the water balance is affected by mountain area percentage within the watershed. For our water balance evaluation, we especially consider precipitation estimates from a variety of datasets, including models, such as WRF and MERRA, and observation-based, such as CRU and GPCP. We ask whether the precipitation datasets provide enough moisture for seasonal snow to accumulate within the basin and whether we see differences in the variability of annual and seasonal precipitation from each dataset. From our reassessment of high-latitude water balances, we aim to determine whether the current understanding is sufficient to describe all processes within the hydrologic cycle or whether datasets appear to be biased, particularly in high-elevation precipitation. Should currently-available datasets appear to be similarly biased in precipitation, as we have seen in mountain snow accumulation, we discuss the implications for the continental water budget.

  20. River water pollution condition in upper part of Brantas River and Bengawan Solo River

    Science.gov (United States)

    Roosmini, D.; Septiono, M. A.; Putri, N. E.; Shabrina, H. M.; Salami, I. R. S.; Ariesyady, H. D.

    2018-01-01

    Wastewater and solid waste from both domestic and industry have been known to give burden on river water quality. Most of river water quality problem in Indonesia has start in the upper part of river due to anthropogenic activities, due to inappropriate land use management including the poor wastewater infrastructure. Base on Upper Citarum River Water pollution problem, it is interesting to study the other main river in Java Island. Bengawan Solo River and Brantas River were chosen as the sample in this study. Parameters assessed in this study are as follows: TSS, TDS, pH, DO, and hexavalent chromium. The status of river water quality are assess using STORET method. Based on (five) parameters, STORET value showed that in Brantas River, Pagerluyung monitoring point had the worst quality relatively compared to other monitoring point in Brantas River with exceeding copper, lead and tin compared to the stream standard in East Java Provincial Regulation No. 2 in 2008. Brantas River was categorized as lightly polluted river based on monitoring period 2011-2015 in 5 monitoring points, namely Pendem, Sengguruh, Kademangan, Meritjan and Kertosono.

  1. 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.

  2. 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.

  3. River-corridor habitat dynamics, Lower Missouri River

    Science.gov (United States)

    Jacobson, Robert B.

    2010-01-01

    Intensive management of the Missouri River for navigation, flood control, and power generation has resulted in substantial physical changes to the river corridor. Historically, the Missouri River was characterized by a shifting, multithread channel and abundant unvegetated sandbars. The shifting channel provided a wide variety of hydraulic environments and large areas of connected and unconnected off-channel water bodies.Beginning in the early 1800s and continuing to the present, the channel of the Lower Missouri River (downstream from Sioux City, Iowa) has been trained into a fast, deep, single-thread channel to stabilize banks and maintain commercial navigation. Wing dikes now concentrate the flow, and revetments and levees keep the channel in place and disconnect it from the flood plain. In addition, reservoir regulation of the Missouri River upstream of Yankton, South Dakota, has substantially changed the annual hydrograph, sediment loads, temperature regime, and nutrient budgets.While changes to the Missouri River have resulted in broad social and economic benefits, they have also been associated with loss of river-corridor habitats and diminished populations of native fish and wildlife species. Today, Missouri River stakeholders are seeking ways to restore some natural ecosystem benefits of the Lower Missouri River without compromising traditional economic uses of the river and flood plain.

  4. Sapucai River Project

    International Nuclear Information System (INIS)

    Duarte, A.L.; Rosa, M.J.

    1988-01-01

    The Sapucai River Project is a gold, ilmenite, monazite and zircon alluvial deposit. It is located on Sapucai River valley in the south of Minas Gerais State. The reserves are 28.000.000 m 3 of pay bed. The production will be 1.400.000 m 3 /year and the mine's life 20 years. A cutterhead suction dredge will do the overburden removal. The pay bed will be mined with an underwater bucket-wheel dredge. The ROM will be concentrated in a washing plant. The gold will be recovered by leaching method. The other heavy minerals will be recovered by electrostatic, magnetic and gravitic methods. SAMITRI believes that it's possible to implant and operate the Project without ecological damage. (author) [pt

  5. Geomorphology and River Management

    Directory of Open Access Journals (Sweden)

    GARY BRIERLEY

    2008-01-01

    Full Text Available Engineering-dominated practices, visible in a "command and control" outlook on natural systems, have induced enormous damage to the environment. Biodiversity losses and declining provision of ecosystem services are testimony to the non-sustainable outcomes brought about by such practices. More environmentally friendly approaches that promote a harmonious relationship between human activities and nature are required. Moves towards an "ecosystem approach" to environmental management require coherent (integrative scientific guidance. Geomorphology, the study of the form of the earth, provides a landscape template with which to ground this process. This way of thinking respects the inherent diversity and complexity of natural systems. Examples of the transition toward such views in environmental practice are demonstrated by the use of science to guide river management, emphasising applications of the River Styles framework.

  6. Heat dispersion in rivers

    International Nuclear Information System (INIS)

    Shaw, T.L.

    1974-01-01

    One of the tasks of the Sonderforschungsbereich 80 is to study the dispersion of heat discharged into rivers and other bodies of water and to develop methods which permit prediction of detrimental effects caused by the heated discharges. In order to help the SFB 80 to specify this task, Dr. Shaw, lecturer of Civil Engineering at the Bristol University, conducted a literature survey on heat-dispersion studies during the two months which he spent as a visiting research fellow with the SFB 80 at the University of Karlsruhe in the summer of 1973. The following report is the outcome of this survey. It gives Dr. Shaw's assessment of the present state of knowledge - based almost exclusively on literature in the English language - and compares this with the knowledge required by river planners. The apparent discrepancy leads to suggestions for future research. Selected references as well as a representative bibliography can be found at the end of the report. (orig.) [de

  7. 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

    ... 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 chinook salmon. The following areas consisting of the water, waterway bottom, and adjacent riparian zone of...

  8. Onilahy River, Madagascar

    Science.gov (United States)

    1982-01-01

    Near the southern tip of Madagascar, the Onilahy River (23.5S, 44E) drains a near barren landscape, the result of rapid deforestation for quick profits from the lumber industry with no regard to the environmental impact. At the turn of the century, the island was a lush tropical paradise with about 90 percent of the surface forested. Now, at the close of the century, only about 10 percent of the forests remain in inaccessible rugged terrain.

  9. Charles River Crossing

    Science.gov (United States)

    2012-04-06

    duration, deck sections will be prefabricated off-site and delivered just-in-time for assembly and installation. The schedule assumes that the parts of...on one side (the side which abuts the existing bridges) there will be the appearance that the new bridges cantilever off the existing bridges. (See...many events that takes place on the Charles River such as crew racings and the “Head of the Charles”. Prefabricated off 19  ANCHORAGE GROUP, LTD

  10. AHP 45: Review: River

    Directory of Open Access Journals (Sweden)

    Phun tshogs dbang rgyal ཕུན་ཚོགས་དབང་རྒྱལ།

    2017-03-01

    Full Text Available Zon thar rgyal says that inspiration for River came with the arrival of his second child (a son, which made his daughter very uncomfortable. "At first, I just wanted to make a simple movie for children as a gift for my daughter,"6 he said during an interview in Lha sa. Later, however, the film became more elaborate with the addition of a grandfather, creating a story that embraces three generations.

  11. Columbia River pathway report

    International Nuclear Information System (INIS)

    1991-07-01

    This report summarizes the river-pathway portion of the first phase of the Hanford Environmental Dose Reconstruction (HEDR) Project. The HEDR Project is estimating radiation doses that could have been received by the public from the Department of Energy's Hanford Site, in southeastern Washington State. Phase 1 of the river-pathway dose reconstruction effort sought to determine whether dose estimates could be calculated for populations in the area from above the Hanford Site at Priest Rapids Dam to below the site at McNary Dam from January 1964 to December 1966. Of the potential sources of radionuclides from the river, fish consumption was the most important. Doses from drinking water were lower at Pasco than at Richland and lower at Kennewick than at Pasco. The median values of preliminary dose estimates calculated by HEDR are similar to independent, previously published estimates of average doses to Richland residents. Later phases of the HEDR Project will address dose estimates for periods other than 1964--1966 and for populations downstream of McNary Dam. 17 refs., 19 figs., 1 tab

  12. The river ecosystem

    International Nuclear Information System (INIS)

    Descy, J.P.; Lambinon, J.

    1984-01-01

    From the standpoint of the ecologist, a river is an ecosystem characterized by its biocoenosis, in dynamic equilibrium with the abiotic environment. This ecosystem can be envisaged at the structural level by examining its physical, chemical and biological properties, together with the relationships existing between these compartments. The biocoenotic structure of a river is relatively complex: it manifests, among other specific features, the presence of plankton communities which show marked space-time variations. The function of the river ecosystem can be approximated by a study of the relationships between the biotic and abiotic components: primary production, secondary production, recycling of organic matter, etc. Lotic environments are subject to frequent disturbance from various forms of man-made pollution: organic pollution, eutrophization, thermal pollution, mineral pollution, contamination by organic and mineral micropollutants, as well as by radionuclides, mechanical pollution and physical degradation. The biocoenotic effects of these forms of pollution may be evaluated, in particular, using biological indicators (bioindicators): these are either able to show the overall impact of the pollution on the biocoenosis or else they permit the detection and evaluation of certain pollutant forms. (author)

  13. 78 FR 28492 - Special Local Regulation; Low Country Splash, Wando River, Cooper River, and Charleston Harbor...

    Science.gov (United States)

    2013-05-15

    ...-AA08 Special Local Regulation; Low Country Splash, Wando River, Cooper River, and Charleston Harbor... establishing a special local regulation on the waters of the Wando River, Cooper River, and Charleston Harbor... rulemaking (NPRM) entitled, ``Special Local Regulation; Low Country Splash, Wando River, Cooper River, and...

  14. 78 FR 18277 - Special Local Regulation; Low Country Splash, Wando River, Cooper River, and Charleston Harbor...

    Science.gov (United States)

    2013-03-26

    ...-AA08 Special Local Regulation; Low Country Splash, Wando River, Cooper River, and Charleston Harbor... proposes to issue a special local regulation on the waters of the Wando River, Cooper River, and Charleston... Country Splash is scheduled to take place on the waters of the Wando River, Cooper River, and Charleston...

  15. Anthropogenic and natural radionuclides in caribou and muskoxen in the Western Alaskan Arctic and marine fish in the Aleutian Islands in the first half of 2000s

    International Nuclear Information System (INIS)

    Hong, Gi Hoon; Baskaran, Mark; Molaroni, Shannon Marie; Lee, Hyun-Mi; Burger, Joanna

    2011-01-01

    A number of caribou and muskoxen samples from the western Alaskan Arctic and fish samples from the Aleutian Islands were collected between 1998 and 2006 and analyzed for anthropogenic ( 90 Sr and 137 Cs) and natural radionculides ( 40 K, 210 Pb and 226 Ra), as part of the radiological assessment for the regional subsistence hunting communities in the first half of 2000s. We examined the relationship between the activities of these nuclides with the size of the fish. In caribou samples, concentration of 90 Sr in muscle was below the detection limit of 0.14 Bq kg -1 and 137 Cs concentration in bones was below the detection limit of 0.15 Bq kg -1 . 137 Cs activity varied over an order of magnitude in caribou muscle samples with an average value of 2.5 Bq/kg wet wt. Average 137 Cs activity in muskoxen muscle was found to be 9.7 Bq/kg wet wt. However, there were a little variation (less than 60%) in 210 Pb, 40 K, and 226 Ra in both muscle and bone of both caribou and muskoxen. The activities of total 210 Pb in caribou and muskox bones were found to be 1-2 orders of magnitude higher than that of parent-supported 210 Pb indicating the potential for dating of bones of terrestrial mammals (time elapsed since the death of the animal) based on the excess 210 Pb method exists. In fish muscle samples, 137 Cs activity varied from below detection limit to 154 mBq/kg wet wt. and its content increased with the size of the fish due to its transfer through the food chain. Among the seven fish species investigated, 210 Pb activities varied almost an order of magnitude; however, 40 K and 226 Ra activities varied less than a factor of two. Total annual effective dose due to 90 Sr and 137 Cs from the ingestion of those terrestrial and marine meats was estimated to be negligible (ca. 9 μSV/a) compared to the natural radionuclides present thus posing negligible radiological threat to humans. - Highlights: → Quantification of radiation dose to humans from the ingestion of fish, muskox

  16. River Restoration and Meanders

    Directory of Open Access Journals (Sweden)

    G. Mathias Kondolf

    2006-12-01

    Full Text Available Among the most visually striking river restoration projects are those that involve the creation of a new channel, often in a new alignment and generally with a form and dimensions that are different from those of the preproject channel. These channel reconstruction projects often have the objective of creating a stable, single-thread, meandering channel, even on rivers that were not historically meandering, on rivers whose sediment load and flow regime would not be consistent with such stable channels, or on already sinuous channels whose bends are not symmetrical. Such meandering channels are often specified by the Rosgen classification system, a popular restoration design approach. Although most projects of this type have not been subject to objective evaluation, completed postproject appraisals show that many of these projects failed within months or years of construction. Despite its, at best, mixed results, this classification and form-based approach continues to be popular because it is easy to apply, because it is accessible to those without formal training in fluvial geomorphology, and probably because it satisfies a deep-seated, although unrecognized, cultural preference for single-thread meandering channels. This preference is consistent with 18th-century English landscape theories, which held the serpentine form to be ideal and led to widespread construction of meandering channels on the country estates of the era. The preference for stability in restored channels seems to be widely accepted by practitioners and funders despite the fact that it is antithetical to research showing that dynamically migrating channels have the greatest ecological richness.

  17. Oceanographic studies in Harrison Bay and the Colville River Delta, Alaska, to support the development of oil spill response strategies

    International Nuclear Information System (INIS)

    Owens, E.H.; Taylor, E.; Hale, B.

    2003-01-01

    The risk of an oil spill resulting from the development of the Alpine oil field is considered to be low. The field is located on the North Slope of Alaska adjacent to the Alaskan Beaufort Sea and reaches coastal waters from the distributary channels of the Colville River Delta. The physical environmental (hydrodynamic) conditions that would affect the transport and fate of spilled oil was investigated to further reduce the risk. During the open-water season of 2001 in Harrison Bay, near shore current meters were deployed and data on weather and surface currents was analyzed. Ocean current and wind measurements were examined to evaluate the relationship between meteorology and water levels during the open-water season. The objective was to gain a better understanding of the near shore hydrodynamic processes at play in Harrison Bay, in order to plan the most appropriate spill response strategies. The results obtained indicate that surface currents within the bay adjacent to the Colville Delta are variable. They respond to wind forces as well as other possible mechanisms like estuarine circulation. The surface currents reach maximum speeds of 0.26 metre per second. For the late July-September deployment, the calculated net surface drift was a 0.02 metre per second current to the east southeast. In both Harrison Bay and Colville Delta, prevailing southwest and northeast winds, respectively, induced water level changes of more than 0.5 metre above and below the average. 7 refs., 3 tabs., 7 figs

  18. Saga of Clinch River

    International Nuclear Information System (INIS)

    Young, W.H.

    1984-01-01

    An epic struggle in the US Congress between what the author calls the forces of transcendence and the forces of experience over development of a breeder reactor for electric power generation is described in this article. The project was started by President Nixon, survived repeated attacks under President Carter, and ironically succumbed under a strong supporter, President Reagan, as a result of an unlikely coalition of conservative organizations and Republican politicians. The broader meanings of the demise of the Clinch River project are examined on several levels, examining the significance for the nation's energy future and for the nation's political future

  19. Lowland river systems - processes, form and function

    DEFF Research Database (Denmark)

    Pedersen, M. L.; Kronvang, B.; Sand-Jensen, K.

    2006-01-01

    Present day river valleys and rivers are not as dynamic and variable as they used to be. We will here describe the development and characteristics of rivers and their valleys and explain the background to the physical changes in river networks and channel forms from spring to the sea. We seek...... to answer two fundamental questions: How has anthropogenic disturbance of rivers changed the fundamental form and physical processes in river valleys? Can we use our understanding of fl uvial patterns to restore the dynamic nature of channelised rivers and drained fl oodplains in river valleys?...

  20. Energy from rivers and oceans

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This chapter discusses the role energy from rivers and oceans may have in the energy future of the US. The topics discussed in the chapter include historical aspects of using energy from rivers and oceans, hydropower assessment including resources, technology and costs, and environmental and regulatory issues, ocean thermal energy conversion including technology and costs and environmental issues, tidal power, and wave power

  1. 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.

  2. 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

  3. Columbia River water quality monitoring

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    Waste water from Hanford activities is discharged at eight points along the Hanford reach of the Columbia River. These discharges consist of backwash water from water intake screens, cooling water, river bank springs, water storage tank overflow, and fish laboratory waste water. Each discharge point is identified in an existing National Pollutant Discharge Elimination System (NPDES) permit issued by the EPA. Effluents from each of these outfalls are routinely monitored and reported by the operating contractors as required by their NPDES permits. Measurements of several Columbia River water quality parameters were conducted routinely during 1982 both upstream and downstream of the Hanford Site to monitor any effects on the river that may be attributable to Hanford discharges and to determine compliance with the Class A designation requirements. The measurements indicated that Hanford operations had a minimal, if any, impact on the quality of the Columbia River water

  4. Global relationships in river hydromorphology

    Science.gov (United States)

    Pavelsky, T.; Lion, C.; Allen, G. H.; Durand, M. T.; Schumann, G.; Beighley, E.; Yang, X.

    2017-12-01

    Since the widespread adoption of digital elevation models (DEMs) in the 1980s, most global and continental-scale analysis of river flow characteristics has been focused on measurements derived from DEMs such as drainage area, elevation, and slope. These variables (especially drainage area) have been related to other quantities of interest such as river width, depth, and velocity via empirical relationships that often take the form of power laws. More recently, a number of groups have developed more direct measurements of river location and some aspects of planform geometry from optical satellite imagery on regional, continental, and global scales. However, these satellite-derived datasets often lack many of the qualities that make DEM=derived datasets attractive, including robust network topology. Here, we present analysis of a dataset that combines the Global River Widths from Landsat (GRWL) database of river location, width, and braiding index with a river database extracted from the Shuttle Radar Topography Mission DEM and the HydroSHEDS dataset. Using these combined tools, we present a dataset that includes measurements of river width, slope, braiding index, upstream drainage area, and other variables. The dataset is available everywhere that both datasets are available, which includes all continental areas south of 60N with rivers sufficiently large to be observed with Landsat imagery. We use the dataset to examine patterns and frequencies of river form across continental and global scales as well as global relationships among variables including width, slope, and drainage area. The results demonstrate the complex relationships among different dimensions of river hydromorphology at the global scale.

  5. 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

  6. Alligator Rivers analogue project

    International Nuclear Information System (INIS)

    Duerden, P.

    1990-01-01

    Australian Nuclear Science and Technology Organization has extensively evaluated uranium ore bodies in the Alligator Rivers Uranium Province in Australia as analogues of radioactive waste repositories. The work was extended for a three-year program as an international project based on the Koongarra uranium deposit and sponsored by the OECD Nuclear Energy Agency. The technical program comprises six major sub-projects involving modelling and experimental work: modelling of radionuclide migration; hydrogeology of the Koongarra uranium deposit; uranium/thorium series disequilibria studies; groundwater and colloid studies; fission product studies; transuranic nuclide studies; an outline of the technical programs and a summary of progress in the technical sub-projects is given. This is followed by a series of technical reports which briefly describe current research tasks, and which have been separately indexed

  7. 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. This journal is © 2012 The Royal Society

  8. Robotics at Savannah River

    International Nuclear Information System (INIS)

    Byrd, J.S.

    1983-01-01

    A Robotics Technology Group was organized at the Savannah River Laboratory in August 1982. Many potential applications have been identified that will improve personnel safety, reduce operating costs, and increase productivity using modern robotics and automation. Several active projects are under way to procure robots, to develop unique techniques and systems for the site's processes, and to install the systems in the actual work environments. The projects and development programs are involved in the following general application areas: (1) glove boxes and shielded cell facilities, (2) laboratory chemical processes, (3) fabrication processes for reactor fuel assemblies, (4) sampling processes for separation areas, (5) emergency response in reactor areas, (6) fuel handling in reactor areas, and (7) remote radiation monitoring systems. A Robotics Development Laboratory has been set up for experimental and development work and for demonstration of robotic systems

  9. HYDROLOGICAL ASSESSMENTS OF SOME RIVERS IN EDO ...

    African Journals Online (AJOL)

    Highest monthly hydropower yields were recorded in September for Ovia, Ikpoba and Edion Rivers and in August for Orlie River. On annual basis, Ovia River, recorded the highest power yield of 61.619MW (suggesting that Ovia river may be suitable for a Medium hydropower scheme, 10MW-100MW) with the highest ...

  10. Assessment of river plan changes in Terengganu River using RS ...

    African Journals Online (AJOL)

    Journal of Fundamental and Applied Sciences ... The database can help in the appropriate understanding of river plan change and know ... The data collected from Geographic Information System (GIS) and Remote Sensing (RS) database.

  11. 78 FR 17087 - Special Local Regulation; New River Raft Race, New River; Fort Lauderdale, FL

    Science.gov (United States)

    2013-03-20

    ...-AA08 Special Local Regulation; New River Raft Race, New River; Fort Lauderdale, FL AGENCY: Coast Guard... on the New River in Fort Lauderdale, Florida during the Rotary Club of Fort Lauderdale New River Raft... States during the Rotary Club of Fort Lauderdale New River Raft Race. On March 23, 2013, Fort Lauderdale...

  12. 76 FR 71342 - Proposed CERCLA Administrative Cost Recovery Settlement; River Forest Dry Cleaners Site, River...

    Science.gov (United States)

    2011-11-17

    ... Settlement; River Forest Dry Cleaners Site, River Forest, Cook County, IL AGENCY: Environmental Protection... response costs concerning the River Forest Dry Cleaners site in River Forest, Cook County, Illinois with... code: C-14J, Chicago, Illinois 60604. Comments should reference the River Forest Dry Cleaners Site...

  13. Hydrological River Drought Analysis (Case Study: Lake Urmia Basin Rivers

    Directory of Open Access Journals (Sweden)

    Mohammad Nazeri Tahrudi

    2017-02-01

    Full Text Available Introduction: Drought from the hydrological viewpoint is a continuation of the meteorological drought that cause of the lack of surface water such as rivers, lakes, reservoirs and groundwater resources. This analysis, which is generally on the surface streams, reservoirs, lakes and groundwater, takes place as hydrological drought considered and studied. So the data on the quantity of flow of the rivers in this study is of fundamental importance. This data are included, level, flow, river flow is no term (5. Overall the hydrological drought studies are focused on annual discharges, maximum annual discharge or minimum discharge period. The most importance of this analysis is periodically during the course of the analysis remains a certain threshold and subthresholdrunoff volume fraction has created. In situations where water for irrigation or water of a river without any reservoir, is not adequate, the minimum flow analysis, the most important factor to be considered (4. The aim of this study is evaluatingthe statistical distributions of drought volume rivers data from the Urmia Lake’s rivers and its return period. Materials and Methods: Urmia Lake is a biggest and saltiest continued lake in Iran. The Lake Urmia basin is one of the most important basins in Iran region which is located in the North West of Iran. With an extent of 52700 square kilometers and an area equivalent to 3.21% of the total area of the country, This basin is located between the circuit of 35 degrees 40 minutes to 38 degrees 29 minutes north latitude and the meridian of 44 degrees 13 minutes to 47 degrees 53 minutes east longitude. In this study used the daily discharge data (m3s-1 of Urmia Lake Rivers. Extraction of river drought volume The drought durations were extracted from the daily discharge of 13 studied stations. The first mean year was calculated for each 365 days using the Eq 1 (14. (1 (For i=1,2,3,…,365 That Ki is aith mean year, Yijis ith day discharge in jth

  14. An Alaskan Theater Airlift Model.

    Science.gov (United States)

    1982-02-19

    entire mission is reJected. The scheduler does not attempt to optimis missions; rather, it sequentially examines each mission in order of priority...AIRDROP MISSIONS (CARGO CODES 3-6) ARE ASSUMED TO REQUIRE C EXTRA BRIEFING AND LOADING TIME. AIRDROPS REQUIRE AN C EXTRA 10 MIN AT DEST BASE FOR LINEUP ...PIGGYBACK KN ATRIDS ONTO ACFT C IF POSITION LEG NEEDED, PUT ITS DATA IN CURRENT LEG SLOTS C (Al-IS), THEN PLACE MISSION LEGS IN SEQUENTIAL LEG SLOTS C

  15. 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 landscape features such as beaded stream pools may be important because of their distribution and role in connecting other water bodies on the landscape. These findings advance techniques for detecting and knowledge associated with potential winter habitat distribution for fish and invertebrates at the local scale in a region of the Arctic with increasing stressors related to climate and land use change.

  16. Riparian Habitat - San Joaquin River

    Data.gov (United States)

    California Natural Resource Agency — 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,...

  17. 33 CFR 162.90 - White River, Arkansas Post Canal, Arkansas River, and Verdigris River between Mississippi River...

    Science.gov (United States)

    2010-07-01

    ... go adrift. Immediately after completion of the emergency mooring, the lockmaster of the first lock... of approach to unattended, normally open automatic, movable span bridges, the factor of river flow...

  18. Anastomosing Rivers are Disequilibrium Patterns

    NARCIS (Netherlands)

    Lavooi, E.; Haas, de T.; Kleinhans, M.G.; Makaske, B.; Smith, D.G.

    2010-01-01

    Anastomosing rivers have multiple interconnected channels that enclose floodbasins. Various theories have been proposed to explain this pattern, including an increased discharge conveyance and sediment transport capacity of multiple channels, or, alternatively, a tendency to avulse due to upstream

  19. Missouri River, Natural Resources Bibliography.

    Science.gov (United States)

    1997-07-01

    1971. Thermal study of the 366. CUNDAY TW, BROOKS KN. 1981. Calibrating Missouri River in North Dakota using infrared and verifying the SSARR model...in North and South 1612. SCHUELER RL, SULLIVAN JK. 1967. Quantifying Dakota using NOAA-5 infrared data. In: current and potential commercial fishery...use survey, 1984. South Dakota River. Journal of the Waterways Department of Game, Fish and Parks. Pierre, 101( WW2 ):119-33. SD. Interim report. South

  20. Continuum Model for River Networks

    Science.gov (United States)

    Giacometti, Achille; Maritan, Amos; Banavar, Jayanth R.

    1995-07-01

    The effects of erosion, avalanching, and random precipitation are captured in a simple stochastic partial differential equation for modeling the evolution of river networks. Our model leads to a self-organized structured landscape and to abstraction and piracy of the smaller tributaries as the evolution proceeds. An algebraic distribution of the average basin areas and a power law relationship between the drainage basin area and the river length are found.

  1. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Hudson River: RVRMILES (River Mile Marker Lines)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains human-use resource data for river miles along the Hudson River. Vector lines in this data set represent river mile markers. This data set...

  2. Hierarchically nested river landform sequences

    Science.gov (United States)

    Pasternack, G. B.; Weber, M. D.; Brown, R. A.; Baig, D.

    2017-12-01

    River corridors exhibit landforms nested within landforms repeatedly down spatial scales. In this study we developed, tested, and implemented a new way to create river classifications by mapping domains of fluvial processes with respect to the hierarchical organization of topographic complexity that drives fluvial dynamism. We tested this approach on flow convergence routing, a morphodynamic mechanism with different states depending on the structure of nondimensional topographic variability. Five nondimensional landform types with unique functionality (nozzle, wide bar, normal channel, constricted pool, and oversized) represent this process at any flow. When this typology is nested at base flow, bankfull, and floodprone scales it creates a system with up to 125 functional types. This shows how a single mechanism produces complex dynamism via nesting. Given the classification, we answered nine specific scientific questions to investigate the abundance, sequencing, and hierarchical nesting of these new landform types using a 35-km gravel/cobble river segment of the Yuba River in California. The nested structure of flow convergence routing landforms found in this study revealed that bankfull landforms are nested within specific floodprone valley landform types, and these types control bankfull morphodynamics during moderate to large floods. As a result, this study calls into question the prevailing theory that the bankfull channel of a gravel/cobble river is controlled by in-channel, bankfull, and/or small flood flows. Such flows are too small to initiate widespread sediment transport in a gravel/cobble river with topographic complexity.

  3. A Rejang River rash

    Directory of Open Access Journals (Sweden)

    Jean-Li Lim

    2014-04-01

    Full Text Available A 30-year-old Iban woman presented to a rural primary healthcare clinic located along the Batang Rejang in Sarawak. She had a 2-day history of rash, which started over her trunk and later spread to her face and limbs. What started out as individual erythematous maculopapular spots later coalesced to form larger raised blotches. The rash was extremely pruritic and affected her sleep, and hence her visit. The rash was preceded by high grade, persistent fever that was temporarily relieved by paracetamol. She also complained of malaise, arthralgia and myalgia. Her appetite had been poor since the onset of the fever. She lived in a long house at the edge of the jungle. Although she did not have a history of going into the jungle to forage, she went regularly to the river to wash clothes. Clinically, she appeared lethargic and had bilateral conjunctival injection. Her left anterior cervical lymph nodes were palpable. There were erythematous macules measuring 5 to 15 mm distributed over her whole body but predominantly over the chest and abdominal region (Figure 1. An unusual skin lesion was discovered at the right hypochondriac region. This lesion resembled a cigarette burn with a necrotic centre (Figure 2. There was no evidence of hepato-splenomegaly. Examination of the other systems was unremarkable. On further questioning, the patient admitted being bitten by a ‘kutu babi’ or mite 3 days before the onset of her fever.

  4. Upper Illinois River basin

    Science.gov (United States)

    Friedel, Michael J.

    1998-01-01

    During the past 25 years, industry and government made large financial investments that resulted in better water quality across the Nation; however, many water-quality concerns remain. Following a 1986 pilot project, the U.S. Geological Survey began implementation of the National Water-Quality Assessment (NAWQA) Program in 1991. This program differs from other national water-quality assessment studies in that the NAWQA integrates monitoring of surface- and ground-water quality with the study of aquatic ecosystems. The goals of the NAWQA Program are to (1) describe current water-quality conditions for a large part of the Nation's freshwater streams and aquifers (water-bearing sediments and rocks), (2) describe how water quality is changing over time, and (3) improve our understanding of the primary natural and human factors affecting water quality.The Upper Illinois River Basin National Water- Quality Assessment (NAWQA) study will increase the scientific understanding of surface- and ground-water quality and the factors that affect water quality in the basin. The study also will provide information needed by water-resource managers to implement effective water-quality management actions and evaluate long-term changes in water quality.

  5. Connectivity in river deltas

    Science.gov (United States)

    Passalacqua, P.; Hiatt, M. R.; Sendrowski, A.

    2016-12-01

    Deltas host approximately half a billion people and are rich in ecosystem diversity and economic resources. However, human-induced activities and climatic shifts are significantly impacting deltas around the world; anthropogenic disturbance, natural subsidence, and eustatic sea-level rise are major causes of threat to deltas and in many cases have compromised their safety and sustainability, putting at risk the people that live on them. In this presentation, I will introduce a framework called Delta Connectome for studying connectivity in river deltas based on different representations of a delta as a network. Here connectivity indicates both physical connectivity (how different portions of the system interact with each other) as well as conceptual (pathways of process coupling). I will explore several network representations and show how quantifying connectivity can advance our understanding of system functioning and can be used to inform coastal management and restoration. From connectivity considerations, the delta emerges as a leaky network that evolves over time and is characterized by continuous exchanges of fluxes of matter, energy, and information. I will discuss the implications of connectivity on delta functioning, land growth, and potential for nutrient removal.

  6. River rating complexity

    Science.gov (United States)

    Holmes, Robert R.

    2016-01-01

    Accuracy of streamflow data depends on the veracity of the rating model used to derive a continuous time series of discharge from the surrogate variables that can readily be collected autonomously at a streamgage. Ratings are typically represented as a simple monotonic increasing function (simple rating), meaning the discharge is a function of stage alone, however this is never truly the case unless the flow is completely uniform at all stages and in transitions from one stage to the next. For example, at some streamflow-monitoring sites the discharge on the rising limb of the hydrograph is discernably larger than the discharge at the same stage on the falling limb of the hydrograph. This is the so-called “loop rating curve” (loop rating). In many cases, these loops are quite small and variation between rising- and falling-limb discharge measurements made at the same stage are well within the accuracy of the measurements. However, certain hydraulic conditions can produce a loop that is large enough to preclude use of a monotonic rating. A detailed data campaign for the Mississippi River at St. Louis, Missouri during a multi-peaked flood over a 56-day period in 2015 demonstrates the rating complexity at this location. The shifting-control method used to deal with complexity at this site matched all measurements within 8%.

  7. Turbulent forces within river plumes affect spread

    Science.gov (United States)

    Bhattacharya, Atreyee

    2012-08-01

    When rivers drain into oceans through narrow mouths, hydraulic forces squeeze the river water into buoyant plumes that are clearly visible in satellite images. Worldwide, river plumes not only disperse freshwater, sediments, and nutrients but also spread pollutants and organisms from estuaries into the open ocean. In the United States, the Columbia River—the largest river by volume draining into the Pacific Ocean from North America—generates a plume at its mouth that transports juvenile salmon and other fish into the ocean. Clearly, the behavior and spread of river plumes, such as the Columbia River plume, affect the nation's fishing industry as well as the global economy.

  8. 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

  9. 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.

  10. Multiple sources of selenium in ancient seafloor hydrothermal systems: Compositional and Se, S, and Pb isotopic evidence from volcanic-hosted and volcanic-sediment-hosted massive sulfide deposits of the Finlayson Lake District, Yukon, Canada

    Science.gov (United States)

    Layton-Matthews, Daniel; Leybourne, Matthew I.; Peter, Jan M.; Scott, Steven D.; Cousens, Brian; Eglington, Bruce M.

    2013-09-01

    Volcanic-hosted massive sulfide (VHMS) and volcanic-sediment-hosted massive sulfide (VSHMS; i.e., hosted by both volcanic and sedimentary rocks) deposits in the Finlayson Lake District, Yukon, Canada, provide a unique opportunity to study the influence of seafloor and sub-seafloor hydrothermal processes on the formation of Se-poor (GP4F VHMS deposit; 7 ppm Se average), intermediate (Kudz Ze Kayah—KZK VHMS deposit; 200 ppm Se average), and Se-enriched (Wolverine VSHMS deposit; 1100 ppm Se average) mineralization. All three deposits are hosted by mid-Paleozoic (˜360-346 Ma) felsic volcanic rocks, but only the Wolverine deposit has voluminous coeval carbonaceous argillites (black shales) in the host rock package. Here we report the first application of Se isotope analyses to ancient seafloor mineralization and use these data, in conjunction with Pb and S isotope analyses, to better understand the source(s) and depositional process(es) of Se within VHMS and VSHMS systems. The wide range of δ82Se (-10.2‰ to 1.3‰, relative to NIST 3149), δ34S (+2.0‰ to +12.8‰ CDT), and elevated Se contents (up to 5865 ppm) within the Wolverine deposit contrast with the narrower range of δ82Se (-3.8‰ to -0.5‰), δ34S (9.8‰ to 13.0‰), and lower Se contents (200 ppm average) of the KZK deposit. The Wolverine and KZK deposits have similar sulfide depositional histories (i.e., deposition at the seafloor, with concomitant zone refining). The Se in the KZK deposit is magmatic (leaching or degassing) in origin, whereas the Wolverine deposit requires an additional large isotopically negative Se source (i.e. ˜-15‰ δ82Se). The negative δ82Se values for the Wolverine deposit are at the extreme light end for measured terrestrial samples, and the lightest observed for hypogene sulfide minerals, but are within calculated equilibrium values of δ82Se relative to NIST 3149 (˜30‰ at 25 °C between SeO4 and Se2-). We propose that the most negative Se isotope values at the

  11. 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

  12. 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.

  13. 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...

  14. 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...

  15. 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:...

  16. 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...

  17. 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...

  18. 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...

  19. Charles River Fish Contaminant Survey, April 2001

    Science.gov (United States)

    Report summarizing a biological monitoring component of the Clean Charles River 2005 initiative through the monitoring & analysis of fish within the lower Charles River basin, implemented by the EPA New England Regional Laboratory in the late fall of 1999.

  20. 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:...

  1. River restoration - Malaysian/DID perspective

    International Nuclear Information System (INIS)

    Ahmad Darus

    2006-01-01

    Initially the river improvement works in Malaysia was weighted on flood control to convey a certain design flood with the lined and channelized rivers. But in late 2003 did has makes the approaches that conservation and improvement of natural function of river, i.e. river environment and eco-system should be incorporated inside the planning and design process. Generally, river restoration will focus on four approaches that will improve water quality, which is improving the quality of stormwater entering the river, maximizing the quantity of the urban river riparian corridor, stabilizing the riverbank, and improving the habitat within the river. This paper outlined the appropriate method of enhancing impairment of water quality from human activities effluent and others effluent. (Author)

  2. Savannah River Site Environmental Implentation Plan

    International Nuclear Information System (INIS)

    1989-01-01

    This report describes the organizational responsibilities for the Savannah River Site Environmental program. Operations, Engineering and projects, Environment, safety, and health, Quality assurance, and the Savannah River Laboratory are described

  3. FLOODPLAIN REDELINEATION SUBMISSION FOR FORT YUKON AK

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — The Floodplain Mapping/Redelineation study deliverables depict and quantify the flood risks for the study area. The primary risk classifications used are the...

  4. 76 FR 25545 - Safety Zone; Blue Crab Festival Fireworks Display, Little River, Little River, SC

    Science.gov (United States)

    2011-05-05

    ...-AA00 Safety Zone; Blue Crab Festival Fireworks Display, Little River, Little River, SC AGENCY: Coast... zone on the waters of Little River in Little River, South Carolina during the Blue Crab Festival... this rule because the Coast Guard did not receive notice of the Blue Crab Festival Fireworks Display...

  5. 78 FR 41689 - Safety Zone; Skagit River Bridge, Skagit River, Mount Vernon, WA

    Science.gov (United States)

    2013-07-11

    ... submerged automobiles and floating bridge debris in the Skagit River. Following the initial response and...-AA00 Safety Zone; Skagit River Bridge, Skagit River, Mount Vernon, WA AGENCY: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY: The Coast Guard is establishing a safety zone around the Skagit River Bridge...

  6. Many rivers to cross. Cross border co-operation in river management

    NARCIS (Netherlands)

    Verwijmeren, J.A.; Wiering, M.A.

    2007-01-01

    River basin management is a key concept in contemporary water policy. Since the management of rivers is best designed and implemented at the scale of the river basin, it seems obvious that we should not confine ourselves to administrative or geographical borders. In other words, river basin

  7. 75 FR 51945 - Safety Zone; Potomac River, St. Mary's River, St. Inigoes, MD

    Science.gov (United States)

    2010-08-24

    ...-AA00 Safety Zone; Potomac River, St. Mary's River, St. Inigoes, MD AGENCY: Coast Guard, DHS. ACTION... of the St. Mary's River, a tributary of the Potomac River. This action is necessary to provide for.... Navy helicopter located near St. Inigoes, Maryland. This safety zone is intended to protect the...

  8. Geochemistry of some Brazilian rivers

    International Nuclear Information System (INIS)

    Moreira-Nordemann, L.M.

    1981-01-01

    Concentrations of the totality of the dissolved salts and sodium, calcium, potassium, magnesium, and uranium were measured in ten rivers belonging to three hydrografic basins located in Northeastern Brazil. Activity ratios U 234 /U 238 were also measured. A correlation was done between the results obtained and the geological and climatic context of these regions. Sodium is the most abundant element in the waters, except for rivers flowing in callcareous regions for which calcium is predominant. The concentrations of the major cations are function of the regional lithology whereas water salinity depends on climatic factors. (Author) [pt

  9. 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.

  10. 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

  11. The radionuclide migration model in river system

    International Nuclear Information System (INIS)

    Zhukova, O.M.; Shiryaeva, N.M.; Myshkina, M.K.; Shagalova, Eh.D.; Denisova, V.V.; Skurat, V.V.

    2001-01-01

    It was propose the model of radionuclide migration in river system based on principle of the compartmental model at hydraulically stationary and chemically equilibrium conditions of interaction of radionuclides in system water-dredge, water-sediments. Different conditions of radioactive contamination entry in river system were considered. The model was verified on the data of radiation monitoring of Iput' river

  12. 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.

  13. 33 CFR 117.1058 - Snake River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Snake River. 117.1058 Section 117... OPERATION REGULATIONS Specific Requirements Washington § 117.1058 Snake River. (a) The draw of the Burlington Northern Santa Fe railroad bridge across the Snake River at mile 1.5 between Pasco and Burbank is...

  14. River as a part of ground battlefield

    Science.gov (United States)

    Vračar, Miodrag S.; Pokrajac, Ivan; Okiljević, Predrag

    2013-05-01

    The rivers are in some circumstances part of the ground battlefield. Microseisms induced at the riverbed or ground at the river surrounding might be consequence of military activities (military ground transports, explosions, troop's activities, etc). Vibrations of those fluid-solid structures are modeled in terms of solid displacement and change of fluid pressure. This time varying fluid pressure in river, which originates from ground microseisms, is possible to detect with hydrophones. Therefore, hydroacoustic measurements in rivers enables detecting, identification and localization various types of military noisy activities at the ground as and those, which origin is in the river water (hydrodynamics of water flow, wind, waves, river vessels, etc). In this paper are presented river ambient noise measurements of the three great rivers: the Danube, the Sava and the Tisa, which flows in north part of Serbia in purpose to establish limits in detection of the ground vibrations in relatively wide frequency range from zero to 20 kHz. To confirm statement that the river is a part of ground battlefield, and that hydroacoustic noise is possible to use in detecting and analyzing ground microseisms induced by civil or military activities, some previous collected data of hydroacoustic noise measurement in the rivers are used. The data of the river ambient noise include noise induced by civil engineering activities, that ordinary take place in large cities, noise that produced ships and ambient noise of the river when human activities are significantly reduced. The poly spectral method was used in analysis such events.

  15. Role of vegetation on river bank accretion

    NARCIS (Netherlands)

    Vargas Luna, A.

    2016-01-01

    There is rising awareness of the need to include the effects of vegetation in studies dealing with the morphological response of rivers. Vegetation growth on river banks and floodplains alters the river bed topography, reduces the bank erosion rates and enhances the development of new floodplains

  16. Hydraulic characteristics of the New River in the New River Gorge National River, West Virginia

    Science.gov (United States)

    Wiley, J.B.; Appel, David H.

    1989-01-01

    Traveltime, dispersion, water-surface and streambed profiles, and cross-section data were collected for use in application of flow and solute-transport models to the New River in the New River Gorge National River, West Virginia. Dye clouds subjected to increasing and decreasing flow rates (unsteady flow) showed that increasing flows shorten the cloud and decreasing flows lengthen the cloud. After the flow rate was changed and the flow was again steady, traveltime and dispersion characteristics were determined by the new rate of flow. Seven stage/streamflow relations identified the general changes of stream geometry throughout the study reach. Channel cross sections were estimated for model input. Low water and streambed profiles were developed from surveyed water surface elevations and water depths. (USGS)

  17. 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 south...

  18. 77 FR 47331 - Regulated Navigation Area-New Haven Harbor, Quinnipiac River, Mill River, New Haven, CT; Pearl...

    Science.gov (United States)

    2012-08-08

    ...-AA11 Regulated Navigation Area--New Haven Harbor, Quinnipiac River, Mill River, New Haven, CT; Pearl... navigable waters of New Haven Harbor, Quinnipiac River and Mill River. The current RNA pertains only to the..., Quinnipiac River, and Mill River RNA. The proposed amendment would give the Captain of the Port Sector Long...

  19. 77 FR 67563 - Regulated Navigation Area-New Haven Harbor, Quinnipiac River, Mill River, New Haven, CT; Pearl...

    Science.gov (United States)

    2012-11-13

    ... 1625-AA11 Regulated Navigation Area--New Haven Harbor, Quinnipiac River, Mill River, New Haven, CT... Haven Harbor, Quinnipiac River and Mill River. The current RNA pertains only to the operation of tugs...) entitled Regulated Navigation Area--New Haven Harbor, Quinnipiac River, Mill River, New Haven, CT; Pearl...

  20. 77 FR 23120 - Special Local Regulations; Lowcountry Splash Open Water Swim, Wando River and Cooper River, Mount...

    Science.gov (United States)

    2012-04-18

    ...-AA08 Special Local Regulations; Lowcountry Splash Open Water Swim, Wando River and Cooper River, Mount... establishing special local regulations on the waters of the Wando River and Cooper River in Mount Pleasant... River and Cooper River along the shoreline of Mount Pleasant, South Carolina. The Lowcountry Splash...

  1. Conservation of South African Rivers

    CSIR Research Space (South Africa)

    O'Keeffe, JH

    1986-01-01

    Full Text Available The report presents the proceedings of a three-day workshop at Midmar Dam designed to establish a consensus view of river conservation and to provide professional conservationists, managers and planners with a set of guidelines. These indicate what...

  2. 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

  3. Rebirth of the Cheat River

    Science.gov (United States)

    The Cheat River in West Virginia is again a haven for whitewater rafting and smallmouth bass fishing after years of Clean Water Act funding and the efforts of a local non-profit group and others to control pollution from old abandoned mines.

  4. Sorting out river channel patterns

    NARCIS (Netherlands)

    Kleinhans, M.G.

    2010-01-01

    Rivers self-organize their pattern/planform through feedbacks between bars, channels, floodplain and vegetation, which emerge as a result of the basic spatial sorting process of wash load sediment and bed sediment. The balance between floodplain formation and destruction determines the width and

  5. Hydrological balance of Cauca River

    International Nuclear Information System (INIS)

    Corzo G, J.; Garcia, M.

    1992-11-01

    This thesis understand the superficial and underground hydrology of the C.c. River Basin; the purpose of this study is to obtain information related to the quantity and behavior of the water resource, in order to make the necessary recommendations for the adequate managing, the aquifer protection and thus be able to have valuable liquid

  6. River habitat assessment for ecological restoration of Wei River Basin, China.

    Science.gov (United States)

    Yang, Tao; Wang, Shuo; Li, Xiaoping; Wu, Ting; Li, Li; Chen, Jia

    2018-04-11

    As an important composition component of river ecosystems, river habitats must undergo quality assessment to potentially provide scientific basis for river ecological restoration. Substrate composition, habitat complexity, bank erosion degree, river meandering degree, human activity intensity, vegetation buffer width, water quality, and water condition were determined as indicators for river habitat assessment. The comprehensive habitat quality index (CHQI) was established for the Wei River Basin. In addition, the indicator values were determined on the basis of a field investigation at 12 national hydrological stations distributed across the Wei, Jing, and Beiluo Rivers. The analytic hierarchy process was used to determine the indicator weights and thus distinguish the relative importance of the assessment indicator system. Results indicated that the average CHQIs for the Wei, Jing, and Beiluo Rivers were 0.417, 0.508, and 0.304, respectively. The river habitat quality for the three rivers was well. As for the whole river basin, the river habitat quality for 25% of the cross section was very well, the other 25% was well, and the 50% remaining was in critical state. The river habitat quality of the Jing River was better than that of the Wei and Beiluo Rivers.

  7. Interlinking of Rivers in India: Issues & Challenges

    OpenAIRE

    MEHTA, Dharmendra; MEHTA, Naveen K.

    2013-01-01

    Abstract. The rivers in India are truly speaking not only life-line of masses but also for wild-life. The rivers play a vital role in the lives of the Indian people. The river systems help us in irrigation, potable water, cheap transportation, electricity as well as a source of livelihood for our ever increasing population. Some of the major cities of India are situated at the banks of holy rivers. Proper management of river water is the need of the hour. Indian agriculture largely d...

  8. The Amazon, measuring a mighty river

    Science.gov (United States)

    ,

    1967-01-01

    The Amazon, the world's largest river, discharges enough water into the sea each day to provide fresh water to the City of New York for over 9 years. Its flow accounts for about 15 percent of all the fresh water discharged into the oceans by all the rivers of the world. By comparison, the Amazon's flow is over 4 times that of the Congo River, the world's second largest river. And it is 10 times that of the Mississippi, the largest river on the North American Continent.

  9. HANFORD SITE RIVER CORRIDOR CLEANUP

    International Nuclear Information System (INIS)

    BAZZELL, K.D.

    2006-01-01

    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 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

  10. The impact of industries on surface water quality of River Ona and ...

    African Journals Online (AJOL)

    Samples of water from two rivers (River Ona and River Alaro) in Oluyole ... were higher in the industrial zones than those found in the upstream of both rivers. ... Key words: River Ona, River Alaro, industrial discharges, surface water quality.

  11. Savannah River Plant/Savannah River Laboratory radiation exposure report

    International Nuclear Information System (INIS)

    Rogers, C.D.; Hyman, S.D.; Keisler, L.L.; Reeder, D.F.; Jolly, L.; Spoerner, M.T.; Schramm, G.R.

    1989-01-01

    The protection of worker health and safety is of paramount concern at the Savannah River Site. Since the site is one of the largest nuclear sites in the nation, radiation safety is a key element in the protection program. This report is a compendium of the results in 1988 of the programs at the Savannah River Plant and the Savannah River Laboratory to protect the radiological health of employees. By any measure, the radiation protection performance at this site in 1988 was the best since the beginning of operations. This accomplishment was made possible by the commitment and support at all levels of the organizations to reduce radiation exposures to ALARA (As Low As Reasonably Achievable). The report provides detailed information about the radiation doses received by departments and work groups within these organizations. It also includes exposure data for recent years to allow Plant and Laboratory units to track the effectiveness of their ALARA efforts. Many of the successful practices and methods that reduced radiation exposure are described. A new goal for personnel contamination cases has been established for 1989. Only through continual and innovative efforts to minimize exposures can the goals be met. The radiation protection goals for 1989 and previous years are included in the report. 27 figs., 58 tabs

  12. Potential relationships between the river discharge and the precipitation in the Jinsha River basin, China

    Science.gov (United States)

    Wang, Gaoxu; Zeng, Xiaofan; Zhao, Na; He, Qifang; Bai, Yiran; Zhang, Ruoyu

    2018-02-01

    The relationships between the river discharge and the precipitation in the Jinsha River basin are discussed in this study. In addition, the future precipitation trend from 2011-2050 and its potential influence on the river discharge are analysed by applying the CCLM-modelled precipitation. According to the observed river discharge and precipitation, the annual river discharge at the two main hydrological stations displays good correlations with the annual precipitation in the Jinsha River basin. The predicted future precipitation tends to change similarly as the change that occurred during the observation period, whereas the monthly distributions over a year could be more uneven, which is unfavourable for water resources management.

  13. Incineration demonstration at Savannah River

    International Nuclear Information System (INIS)

    Lewandowski, K.E.; Becker, G.W.; Mersman, K.E.; Roberson, W.A.

    1983-01-01

    A full-scale incineration process for Savannah River Plant (SRP) low level beta-gamma combustible waste was demonstrated at the Savannah River Laboratory (SRL) using nonradioactive wastes. From October 1981 through September 1982, 15,700 kilograms of solid waste and 5.7 m 3 of solvent were incinerated. Emissions of off-gas components (NO/sub x/, SO 2 , CO, and particulates) were well below South Carolina state standards. Volume reductions of 20:1 for solid waste and 7:1 for Purex solvent/lime slurry were achieved. Presently, the process is being upgraded by SRP to accept radioactive wastes. During a two-year SRP demonstration, the facility will be used to incinerate slightly radioactive ( 3 ) solvent and suspect level (<1 mR/hr at 0.0254 meter) solid wastes

  14. Large-scale river regulation

    International Nuclear Information System (INIS)

    Petts, G.

    1994-01-01

    Recent concern over human impacts on the environment has tended to focus on climatic change, desertification, destruction of tropical rain forests, and pollution. Yet large-scale water projects such as dams, reservoirs, and inter-basin transfers are among the most dramatic and extensive ways in which our environment has been, and continues to be, transformed by human action. Water running to the sea is perceived as a lost resource, floods are viewed as major hazards, and wetlands are seen as wastelands. River regulation, involving the redistribution of water in time and space, is a key concept in socio-economic development. To achieve water and food security, to develop drylands, and to prevent desertification and drought are primary aims for many countries. A second key concept is ecological sustainability. Yet the ecology of rivers and their floodplains is dependent on the natural hydrological regime, and its related biochemical and geomorphological dynamics. (Author)

  15. Savannah River Plant incinerator demonstration

    International Nuclear Information System (INIS)

    Lewandowski, K.E.

    1983-01-01

    A full-scale incineration process was demonstrated at the Savannah River Laboratory (SRL) using nonradioactive waste. From October 1981 through September 1982, 15,700 kilograms of solid waste and 5.7 m 3 of solvent were incinerated. Emissions of off-gas components (NO/sub x/, SO 2 , CO, and particulates) were well below South Carolina state standards. Volume reductions of 20:1 for solid waste and 7:1 for Purex solvent/lime slurry were achieved. The process has been relocated and upgraded by the Savannah River Plant to accept low-level beta-gamma combustibles. During a two-year demonstration, the facility will incinerate slightly radioactive ( 3 ) solvent and suspect level (< 1 mR/h at 0.0254 meter) solid wastes. This demonstration will begin in early 1984

  16. Naturalness and Place in River Rehabilitation

    Directory of Open Access Journals (Sweden)

    Kirstie Fryirs

    2009-06-01

    Full Text Available An authentic approach to river rehabilitation emphasizes concerns for the natural values of a given place. As landscape considerations fashion the physical template upon which biotic associations take place, various geomorphic issues must be addressed in framing rehabilitation activities that strive to improve river health. An open-ended approach to river classification promotes applications that appreciate the values of a given river, rather than pigeonholing reality. As the geomorphic structure of some rivers is naturally simple, promoting heterogeneity as a basis for management may not always be appropriate. Efforts to protect unique attributes of river systems must be balanced with procedures that look after common features. Concerns for ecosystem functionality must relate to the behavioral regime of a given river, remembering that some rivers are inherently sensitive to disturbance. Responses to human disturbance must be viewed in relation to natural variability, recognizing how spatial relationships in a catchment, and responses to past disturbances, fashion the operation of contemporary fluxes. These fluxes, in turn, influence what is achievable in the rehabilitation of a given reach. Given the inherently adjusting and evolutionary nature of river systems, notional endpoints do not provide an appropriate basis upon which to promote concepts of naturalness and place in the rehabilitation process. These themes are drawn together to promote rehabilitation practices that relate to the natural values of each river system, in preference to applications of "cookbook" measures that build upon textbook geomorphology.

  17. Radiocesium dynamics in the Hirose River basin

    Science.gov (United States)

    Kuramoto, T.; Taniguchi, K.; Arai, H.; Onuma, S.; Onishi, Y.

    2017-12-01

    A significant amount of radiocesium was deposited in Fukushima Prefecture during the accident of Fukushima Daiichi Nuclear Power Plant. In river systems, radiocesium is transported to downstream in rivers. For the safe use of river and its water, it is needed to clarify the dynamics of radiocesium in river systems. We started the monitoring of the Hirose River from December 2015. The Hirose River is a tributary of the Abukuma River flowing into the Pacific Ocean, and its catchment is close to areas where a large amount of radiocesium was deposited. We set up nine monitoring points in the Hirose River watershed. The Water level and turbidity data are continuously observed at each monitoring point. We regularly collected about 100 liters of water at each monitoring point. Radiocesium in water samples was separated into two forms; the one is the dissolved form, and the other is the suspended particulate form. Radionuclide concentrations of radiocesium in both forms were measured by a germanium semiconductor detector. Furthermore, we applied the TODAM (Time-dependent One-dimensional Degradation And Migration) code to the Hirose River basin using the monitoring data. The objectives of the modeling are to understand a redistribution pattern of radiocesium adsorbed by sediments during flooding events and to determine the amount of radiocesium flux into the Abukuma River.

  18. Clinical cytogenetics in river buffalo

    Directory of Open Access Journals (Sweden)

    L. Zicarelli

    2011-03-01

    Full Text Available While autosomal numeric chromosome abnormalities are phenotipically visible (abnormal body conformation and easily eliminated during the normal breeding selection, sex numeric abnormalities (including the cases of free-martinism, as well as the structural chromosome aberrations, especially the balanced ones, are more tolerate by the animals (normal body conformation but are often responsible of low fertility (structural abnormalities or sterility (sex chromosome aberrations, especially in the females. Although river buffalo (Bubalus bubalis, 2n=50 chromosomes have been characterized......

  19. Chester River Study. Volume I,

    Science.gov (United States)

    1972-11-01

    of the effects of agri- i6 IA -46 cultural activities on the aquatic system. This initial feet (24 meters). The soils of the basin area are suit...to the stocks themselves. The shell crystal struc- ture modification in oysters recalls to mind the eggshell thinning in birds mentioned earlier...with figures provided by Chestertown to the mouth of the River at Love the U.S. Soil Conservation Service as of 1967 (last Point (Table VII). year of

  20. Flambeau River Biofuels Demonstration Plant

    Energy Technology Data Exchange (ETDEWEB)

    Byrne, Robert J. [Flambeau River Biofuels, Inc., Park Falls, WI (United States)

    2012-07-30

    Flambeau River BioFuels, Inc. (FRB) proposed to construct a demonstration biomass-to-liquids (BTL) biorefinery in Park Falls, Wisconsin. The biorefinery was to be co-located at the existing pulp and paper mill, Flambeau River Papers, and when in full operation would both generate renewable energy – making Flambeau River Papers the first pulp and paper mill in North America to be nearly fossil fuel free – and produce liquid fuels from abundant and renewable lignocellulosic biomass. The biorefinery would serve to validate the thermochemical pathway and economic models for BTL production using forest residuals and wood waste, providing a basis for proliferating BTL conversion technologies throughout the United States. It was a project goal to create a compelling new business model for the pulp and paper industry, and support the nation’s goal for increasing renewable fuels production and reducing its dependence on foreign oil. FRB planned to replicate this facility at other paper mills after this first demonstration scale plant was operational and had proven technical and economic feasibility.

  1. Buck Creek River Flow Analysis

    Science.gov (United States)

    Dhanapala, Yasas; George, Elizabeth; Ritter, John

    2009-04-01

    Buck Creek flowing through Springfield Ohio has a number of low-head dams currently in place that cause safety issues and sometimes make it impossible for recreational boaters to pass through. The safety issues include the back eddies created by the dams that are known as drowning machines and the hydraulic jumps. In this study we are modeling the flow of Buck Creek using topographical and flow data provided by the Geology Department of Wittenberg University. The flow is analyzed using Hydraulic Engineering Center - River Analysis System software (HEC-RAS). As the first step a model of the river near Snyder Park has been created with the current structure in place for validation purposes. Afterwards the low-head dam is replaced with four drop structures with V-notch overflow gates. The river bed is altered to reflect plunge pools after each drop structure. This analysis will provide insight to how the flow is going to behave after the changes are made. In addition a sediment transport analysis is also being conducted to provide information about the stability of these structures.

  2. Misrepresenting the Jordan River Basin

    Directory of Open Access Journals (Sweden)

    Clemens Messerschmid

    2015-06-01

    Full Text Available This article advances a critique of the UN Economic and Social Commission for West Asia’s (ESCWA’s representation of the Jordan River Basin, as contained in its recently published Inventory of Shared Water Resources in Western Asia. We argue that ESCWA’s representation of the Jordan Basin is marked by serious technical errors and a systematic bias in favour of one riparian, Israel, and against the Jordan River’s four Arab riparians. We demonstrate this in relation to ESCWA’s account of the political geography of the Jordan River Basin, which foregrounds Israel and its perspectives and narratives; in relation to hydrology, where Israel’s contribution to the basin is overstated, whilst that of Arab riparians is understated; and in relation to development and abstraction, where Israel’s transformation and use of the basin are underplayed, while Arab impacts are exaggerated. Taken together, this bundle of misrepresentations conveys the impression that it is Israel which is the main contributor to the Jordan River Basin, Arab riparians its chief exploiters. This impression is, we argue, not just false but also surprising, given that the Inventory is in the name of an organisation of Arab states. The evidence discussed here provides a striking illustration of how hegemonic hydro-political narratives are reproduced, including by actors other than basin hegemons themselves.

  3. Synchronisation and stability in river metapopulation networks.

    Science.gov (United States)

    Yeakel, J D; Moore, J W; Guimarães, P R; de Aguiar, M A M

    2014-03-01

    Spatial structure in landscapes impacts population stability. Two linked components of stability have large consequences for persistence: first, statistical stability as the lack of temporal fluctuations; second, synchronisation as an aspect of dynamic stability, which erodes metapopulation rescue effects. Here, we determine the influence of river network structure on the stability of riverine metapopulations. We introduce an approach that converts river networks to metapopulation networks, and analytically show how fluctuation magnitude is influenced by interaction structure. We show that river metapopulation complexity (in terms of branching prevalence) has nonlinear dampening effects on population fluctuations, and can also buffer against synchronisation. We conclude by showing that river transects generally increase synchronisation, while the spatial scale of interaction has nonlinear effects on synchronised dynamics. Our results indicate that this dual stability - conferred by fluctuation and synchronisation dampening - emerges from interaction structure in rivers, and this may strongly influence the persistence of river metapopulations. © 2013 John Wiley & Sons Ltd/CNRS.

  4. Geochemistry, petrography, and zircon U-Pb geochronology of Paleozoic metaigneous rocks in the Mount Veta area of east-central Alaska: implications for the evolution of the westernmost part of the Yukon-Tanana terrane

    Science.gov (United States)

    Dusel-Bacon, Cynthia; Day, Warren C.; Aleinikoff, John N.

    2013-01-01

    We report the results of new mapping, whole-rock major, minor, and trace-element geochemistry, and petrography for metaigneous rocks from the Mount Veta area in the westernmost part of the allochthonous Yukon–Tanana terrane (YTT) in east-central Alaska. These rocks include tonalitic mylonite gneiss and mafic metaigneous rocks from the Chicken metamorphic complex and the Nasina and Fortymile River assemblages. Whole-rock trace-element data from the tonalitic gneiss, whose igneous protolith was dated by SHRIMP U–Pb zircon geochronology at 332.6 ± 5.6 Ma, indicate derivation from tholeiitic arc basalt. Whole-rock analyses of the mafic rocks suggest that greenschist-facies rocks from the Chicken metamorphic complex, a mafic metavolcanic rock from the Nasina assemblage, and an amphibolite from the Fortymile River assemblage formed as island-arc tholeiite in a back-arc setting; another Nasina assemblage greenschist has MORB geochemical characteristics, and another mafic metaigneous rock from the Fortymile River assemblage has geochemical characteristics of calc-alkaline basalt. Our geochemical results imply derivation in an arc and back-arc spreading region within the allochthonous YTT crustal fragment, as previously proposed for correlative units in other parts of the terrane. We also describe the petrography and geochemistry of a newly discovered tectonic lens of Alpine-type metaharzburgite. The metaharzburgite is interpreted to be a sliver of lithospheric mantle from beneath the Seventymile ocean basin or from sub-continental mantle lithosphere of the allochthonous YTT or the western margin of Laurentia that was tectonically emplaced within crustal rocks during closure of the Seventymile ocean basin and subsequently displaced and fragmented by faults.

  5. Priority River Metrics for Urban Residents of the Santa Cruz River Watershed

    Science.gov (United States)

    Indicator selection is a persistent question in river and stream assessment and management. We employ qualitative research techniques to identify features of rivers and streams important to urban residents recruited from the general public in the Santa Cruz watershed. Interviews ...

  6. New River Dam Foundation Report. Gila River Basin: Phoenix, Arizona and Vicinity (Including New River).

    Science.gov (United States)

    1985-10-01

    further downstream before merging with the Agua Fria River. 6 Site Geology 2.08 The geological formations present within the project area consist...sampling and in- situ density testing using the sand displacement 11 or large-scale water displacement method. Dozer trenches TT82-1 and TT82-6 were excavated...underlying the valley or may, due to its pervasiveness, represent an in situ weathering product of the buried bedrock. 4.18 Because of the magnitude

  7. Flood characteristics for the New River in the New River Gorge National River, West Virginia

    Science.gov (United States)

    Wiley, J.B.; Cunningham, M.K.

    1994-01-01

    The frequency and magnitude of flooding of the New River in the New River Gorge National River was studied. A steady-state, one-dimensional flow model was applied to the study reach. Rating curves, cross sections, and Manning's roughness coefficients that were used are presented in this report. Manning's roughness coefficients were evaluated by comparing computed elevations (from application of the steady-state, one-dimensional flow model) to rated elevations at U.S. Geological Survey (USGS) streamflow-gaging stations and miscellaneous-rating sites. Manning's roughness coefficients ranged from 0.030 to 0.075 and varied with hydraulic depth. The 2-, 25-, and 100-year flood discharges were esti- mated on the basis of information from flood- insurance studies of Summers County, Fayette County, and the city of Hinton, and flood-frequency analysis of discharge records for the USGS streamflow-gaging stations at Hinton and Thurmond. The 100-year discharge ranged from 107,000 cubic feet per second at Hinton to 150,000 cubic feet per second at Fayette.

  8. Miocene-Recent sediment flux in the south-central Alaskan fore-arc basin governed by flat-slab subduction

    Science.gov (United States)

    Finzel, Emily S.; Enkelmann, Eva

    2017-04-01

    The Cook Inlet in south-central Alaska contains the early Oligocene to Recent stratigraphic record of a fore-arc basin adjacent to a shallowly subducting oceanic plateau. Our new measured stratigraphic sections and detrital zircon U-Pb geochronology and Hf isotopes from Neogene strata and modern rivers illustrate the effects of flat-slab subduction on the depositional environments, provenance, and subsidence in fore-arc sedimentary systems. During the middle Miocene, fluvial systems emerged from the eastern, western, and northern margins of the basin. The axis of maximum subsidence was near the center of the basin, suggesting equal contributions from subsidence drivers on both margins. By the late Miocene, the axis of maximum subsidence had shifted westward and fluvial systems originating on the eastern margin of the basin above the flat-slab traversed the entire width of the basin. These mud-dominated systems reflect increased sediment flux from recycling of accretionary prism strata. Fluvial systems with headwaters above the flat-slab region continued to cross the basin during Pliocene time, but a change to sandstone-dominated strata with abundant volcanogenic grains signals a reactivation of the volcanic arc. The axis of maximum basin subsidence during late Miocene to Pliocene time is parallel to the strike of the subducting slab. Our data suggest that the character and strike-orientation of the down-going slab may provide a fundamental control on the nature of depositional systems, location of dominant provenance regions, and areas of maximum subsidence in fore-arc basins.

  9. Classification of Tropical River Using Chemometrics Technique: Case Study in Pahang River, Malaysia

    International Nuclear Information System (INIS)

    Mohd Khairul Amri Kamarudin; Mohd Ekhwan Toriman; Nur Hishaam Sulaiman

    2015-01-01

    River classification is very important to know the river characteristic in study areas, where this database can help to understand the behaviour of the river. This article discusses about river classification using Chemometrics techniques in mainstream of Pahang River. Based on river survey, GIS and Remote Sensing database, the chemometric analysis techniques have been used to identify the cluster on the Pahang River using Hierarchical Agglomerative Cluster Analysis (HACA). Calibration and validation process using Discriminant Analysis (DA) has been used to confirm the HACA result. Principal Component Analysis (PCA) study to see the strong coefficient where the Pahang River has been classed. The results indicated the main of Pahang River has been classed to three main clusters as upstream, middle stream and downstream. Base on DA analysis, the calibration and validation model shows 100 % convinced. While the PCA indicates there are three variables that have a significant correlation, domination slope with R"2 0.796, L/D ratio with R"2 -0868 and sinuosity with R"2 0.557. Map of the river classification with moving class also was produced. Where the green colour considered in valley erosion zone, yellow in a low terrace of land near the channels and red colour class in flood plain and valley deposition zone. From this result, the basic information can be produced to understand the characteristics of the main Pahang River. This result is important to local authorities to make decisions according to the cluster or guidelines for future study in Pahang River, Malaysia specifically and for Tropical River generally. The research findings are important to local authorities by providing basic data as a guidelines to the integrated river management at Pahang River, and Tropical River in general. (author)

  10. Urban river design and aesthetics: A river restoration case study from the UK

    OpenAIRE

    Prior, Jonathan

    2016-01-01

    This paper analyses the restoration of an urbanized section of the River Skerne where it flows through a suburb of Darlington, England; a project which was one of the first comprehensive urban river restorations undertaken in the UK. It is shown how aesthetic values were central to the identification of the River Skerne as a site for restoration, the production of restoration objectives, and a design vision of urban river renewal via restoration. Secondly, the means by which these aesthetic v...

  11. River flow controls on tides an tide-mean water level profiles in a tidel freshwater river

    NARCIS (Netherlands)

    Sassi, M.G.; Hoitink, A.J.F.

    2013-01-01

    [1] Tidal rivers feature oscillatory and steady gradients in the water surface, controlled by interactions between river flow and tides. The river discharge attenuates the tidal motion, and tidal motion increases tidal-mean friction in the river, which may act as a barrier to the river discharge.

  12. Savannah River Laboratory monthly report, November 1991

    Energy Technology Data Exchange (ETDEWEB)

    Ferrell, J.M. (comp.)

    1991-01-01

    This document details monthly activities at the Savannah River Laboratory. Topics addressed are reactor operation; tritium facilities and production; separation operations; environmental concerns; and waste management. (FI)

  13. Savannah River Laboratory monthly report, November 1991

    Energy Technology Data Exchange (ETDEWEB)

    Ferrell, J.M. [comp.

    1991-12-31

    This document details monthly activities at the Savannah River Laboratory. Topics addressed are reactor operation; tritium facilities and production; separation operations; environmental concerns; and waste management. (FI)

  14. Savannah River Laboratory monthly report, October 1991

    Energy Technology Data Exchange (ETDEWEB)

    Ferrell, J.M. (comp.)

    1991-01-01

    This document details monthly activities at the Savannah River Laboratory. Topics addressed are reactor operation, tritium facilities and production; separations operations; environmental concerns; and waste management. (FI)

  15. Savannah River Laboratory monthly report, October 1991

    Energy Technology Data Exchange (ETDEWEB)

    Ferrell, J.M. [comp.

    1991-12-31

    This document details monthly activities at the Savannah River Laboratory. Topics addressed are reactor operation, tritium facilities and production; separations operations; environmental concerns; and waste management. (FI)

  16. VT River Restoration Data in Lamoille County

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) Documented river and riparian buffer restoration projects in Lamoille County, Vermont. Restoration includes buffer plantings (trees and shrubs),...

  17. The Columbia River System Inside Story

    Energy Technology Data Exchange (ETDEWEB)

    None

    2001-04-01

    The Columbia River is one of the greatest natural resources in the western United States. The river and its tributaries touch the lives of nearly every resident of the Pacific Northwest—from fostering world-famous Pacific salmon to supplying clean natural fuel for 50 to 65 percent of the region’s electrical generation. Since early in the 20th century, public and private agencies have labored to capture the benefits of this dynamic river. Today, dozens of major water resource projects throughout the region are fed by the waters of the Columbia Basin river system.

  18. Savannah River Laboratory monthly report, September 1991

    Energy Technology Data Exchange (ETDEWEB)

    Ferrell, J.M. (comp.)

    1991-01-01

    This document details monthly activities at the Savannah River Laboratory. Topics addressed are reactor operation, tritium facilities and production; separation operations; environmental concerns; and waste management. (FI)

  19. Savannah River Laboratory monthly report, September 1991

    Energy Technology Data Exchange (ETDEWEB)

    Ferrell, J.M. [comp.

    1991-12-31

    This document details monthly activities at the Savannah River Laboratory. Topics addressed are reactor operation, tritium facilities and production; separation operations; environmental concerns; and waste management. (FI)

  20. Bathymetric surveys of the Neosho River, Spring River, and Elk River, northeastern Oklahoma and southwestern Missouri, 2016–17

    Science.gov (United States)

    Hunter, Shelby L.; Ashworth, Chad E.; Smith, S. Jerrod

    2017-09-26

    In February 2017, the Grand River Dam Authority filed to relicense the Pensacola Hydroelectric Project with the Federal Energy Regulatory Commission. The predominant feature of the Pensacola Hydroelectric Project is Pensacola Dam, which impounds Grand Lake O’ the Cherokees (locally called Grand Lake) in northeastern Oklahoma. Identification of information gaps and assessment of project effects on stakeholders are central aspects of the Federal Energy Regulatory Commission relicensing process. Some upstream stakeholders have expressed concerns about the dynamics of sedimentation and flood flows in the transition zone between major rivers and Grand Lake O’ the Cherokees. To relicense the Pensacola Hydroelectric Project with the Federal Energy Regulatory Commission, the hydraulic models for these rivers require high-resolution bathymetric data along the river channels. In support of the Federal Energy Regulatory Commission relicensing process, the U.S. Geological Survey, in cooperation with the Grand River Dam Authority, performed bathymetric surveys of (1) the Neosho River from the Oklahoma border to the U.S. Highway 60 bridge at Twin Bridges State Park, (2) the Spring River from the Oklahoma border to the U.S. Highway 60 bridge at Twin Bridges State Park, and (3) the Elk River from Noel, Missouri, to the Oklahoma State Highway 10 bridge near Grove, Oklahoma. The Neosho River and Spring River bathymetric surveys were performed from October 26 to December 14, 2016; the Elk River bathymetric survey was performed from February 27 to March 21, 2017. Only areas inundated during those periods were surveyed.The bathymetric surveys covered a total distance of about 76 river miles and a total area of about 5 square miles. Greater than 1.4 million bathymetric-survey data points were used in the computation and interpolation of bathymetric-survey digital elevation models and derived contours at 1-foot (ft) intervals. The minimum bathymetric-survey elevation of the Neosho

  1. Comparative Research on River Basin Management in the Sagami River Basin (Japan and the Muda River Basin (Malaysia

    Directory of Open Access Journals (Sweden)

    Lay Mei Sim

    2018-05-01

    Full Text Available In the world, river basins often interwoven into two or more states or prefectures and because of that, disputes over water are common. Nevertheless, not all shared river basins are associated with water conflicts. Rivers in Japan and Malaysia play a significant role in regional economic development. They also play a significant role as water sources for industrial, domestic, agricultural, aquaculture, hydroelectric power generation, and the environment. The research aim is to determine the similarities and differences between the Sagami and Muda River Basins in order to have a better understanding of the governance needed for effectively implementing the lessons drawn from the Sagami River Basin for improving the management of the Muda River Basin in Malaysia. This research adopts qualitative and quantitative approaches. Semi-structured interviews were held with the key stakeholders from both basins and show that Japan has endeavored to present policy efforts to accommodate the innovative approaches in the management of their water resources, including the establishment of a river basin council. In Malaysia, there is little or no stakeholder involvement in the Muda River Basin, and the water resource management is not holistic and is not integrated as it should be. Besides that, there is little or no Integrated Resources Water Management, a pre-requisite for sustainable water resources. The results from this comparative study concluded that full support and participation from public stakeholders (meaning the non-government and non-private sector stakeholders is vital for achieving sustainable water use in the Muda River Basin. Integrated Water Resources Management (IWRM approaches such as the introduction of payments for ecosystems services and the development of river basin organization in the Muda River Basin should take place in the spirit of political willingness.

  2. 78 FR 36658 - Safety Zone; Delaware River Waterfront Corp. Fireworks Display, Delaware River; Camden, NJ

    Science.gov (United States)

    2013-06-19

    ... portion of the Delaware River from operating while a fireworks event is taking place. This temporary...-AA00 Safety Zone; Delaware River Waterfront Corp. Fireworks Display, Delaware River; Camden, NJ AGENCY: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY: The Coast Guard is establishing a temporary...

  3. 78 FR 22423 - Drawbridge Operation Regulations; Taunton River, Fall River and Somerset, MA

    Science.gov (United States)

    2013-04-16

    ... Operation Regulations; Taunton River, Fall River and Somerset, MA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation from regulation. SUMMARY: The Coast Guard is issuing a temporary deviation from the regulation governing the operation of the Brightman Street Bridge across the Taunton River...

  4. River-tide dynamics : Exploration of nonstationary and nonlinear tidal behavior in the Yangtze River estuary

    NARCIS (Netherlands)

    Guo, L.; Van der Wegen, M.; Jay, D.A.; Matte, P.; Wang, Z.B.; Roelvink, J.A.; He, Q.

    2015-01-01

    River-tide dynamics remain poorly understood, in part because conventional harmonic analysis (HA) does not cope effectively with nonstationary signals. To explore nonstationary behavior of river tides and the modulation effects of river discharge, this work analyzes tidal signals in the Yangtze

  5. Rivers running deep : complex flow and morphology in the Mahakam River, Indonesia

    NARCIS (Netherlands)

    Vermeulen, B.

    2014-01-01

    Rivers in tropical regions often challenge our geomorphological understanding of fluvial systems. Hairpin bends, natural scours, bifurcate meander bends, tie channels and embayments in the river bank are a few examples of features ubiquitous in tropical rivers. Existing observation techniques

  6. 76 FR 24914 - Digital River Education Services, Inc., a Division of Digital River, Inc., Including Workers...

    Science.gov (United States)

    2011-05-03

    ... Digital River Education Services acquired Journey Education Marketing (JEM) in August 2010. Some workers... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-74,975] Digital River Education Services, Inc., a Division of Digital River, Inc., Including Workers Whose Unemployment Insurance (UI...

  7. Return to the river: strategies for salmon restoration in the Columbia River Basin.

    Science.gov (United States)

    Richard N. Williams; Jack A. Standford; James A. Lichatowich; William J. Liss; Charles C. Coutant; Willis E. McConnaha; Richard R. Whitney; Phillip R. Mundy; Peter A. Bisson; Madison S. Powell

    2006-01-01

    The Columbia River today is a great "organic machine" (White 1995) that dominates the economy of the Pacific Northwest. Even though natural attributes remain—for example, salmon production in Washington State's Hanford Reach, the only unimpounded reach of the mainstem Columbia River—the Columbia and Snake River mainstems are dominated...

  8. 33 CFR 207.10 - Charles River, Mass.; dam of Charles River Basin Commission.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Charles River, Mass.; dam of Charles River Basin Commission. 207.10 Section 207.10 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.10 Charles River, Mass.; dam of...

  9. 75 FR 33690 - Safety Zone, Lights on the River Fireworks Display, Delaware River, New Hope, PA

    Science.gov (United States)

    2010-06-15

    ... scenario with potential for loss of life and property. Basis and Purpose The New Hope Chamber of Commerce... to protect life and property operating on the navigable waterways of the Delaware River in New Hope...-AA00 Safety Zone, Lights on the River Fireworks Display, Delaware River, New Hope, PA AGENCY: Coast...

  10. The Influence of Water Conservancy Projects on River Network Connectivity, A Case of Luanhe River Basin

    Science.gov (United States)

    Li, Z.; Li, C.

    2017-12-01

    Connectivity is one of the most important characteristics of a river, which is derived from the natural water cycle and determine the renewability of river water. The water conservancy project can change the connectivity of natural river networks, and directly threaten the health and stability of the river ecosystem. Based on the method of Dendritic Connectivity Index (DCI), the impacts from sluices and dams on the connectivity of river network are deeply discussed herein. DCI quantitatively evaluate the connectivity of river networks based on the number of water conservancy facilities, the connectivity of fish and geographical location. The results show that the number of water conservancy facilities and their location in the river basin have a great influence on the connectivity of the river network. With the increase of the number of sluices and dams, DCI is decreasing gradually, but its decreasing range is becoming smaller and smaller. The dam located in the middle of the river network cuts the upper and lower parts of the whole river network, and destroys the connectivity of the river network more seriously. Therefore, this method can be widely applied to the comparison of different alternatives during planning of river basins and then provide a reference for the site selection and design of the water conservancy project and facility concerned.

  11. 77 FR 23658 - Six Rivers National Forest, Gasquet Ranger District, California, The Smith River National...

    Science.gov (United States)

    2012-04-20

    ... National Forest, Gasquet Ranger District, California, The Smith River National Recreation Area [email protected] . Please insure that ``Smith River NRA Restoration and Motorized Travel Management'' occurs... UARs totaling 80 miles. The project encompasses the Smith River NRA and Gasquet Ranger District...

  12. Effects of urbanization on river morphology of the Talar River, Mazandarn Province, Iran

    NARCIS (Netherlands)

    Yousefi, Saleh; Moradi, Hamid Reza; Keesstra, Saskia; Pourghasemi, Hamid Reza; Navratil, Oldrich; Hooke, Janet

    2017-01-01

    In the present study, we investigate the effects of urbanization growth on river morphology in the downstream part of Talar River, east of Mazandaran Province, Iran. Morphological and morphometric parameters in 10 equal sub-reaches were defined along a 11.5 km reach of the Talar River after land

  13. A Journey into AlaskaWhen I went to Alaska to study humans in nature, I wrote a story to summarize my research. It follows Caleb as he goes through Alaskan wilderness. He contrasts the peaceful ways of the Tlingit. His materialistic motives clash with others. The story ends with him dying in the wild. Caleb symbolizes unrightfully using natural resources.

    Science.gov (United States)

    Hosseini, A.

    2017-12-01

    When I went to Alaska to study humanity's place in nature, I crafted a short piece of writing as a way to summarize what I learned. The story follows the path of Caleb as he goes through the Alaskan wilderness. His actions contrast heavily with the peaceful ways of Alaska's natives, the Tlingit, and his selfish, materialistic motives clash with those of others he meets. The story ends with him dying alone, succumbing to Mother Nature's defeat. Caleb represents those who utilize natural resources at their own gain, and his journey shows the same trap many others have fallen into.

  14. Sediment Size Distribution at Three Rivers with Different Types of ...

    African Journals Online (AJOL)

    ADOWIE PERE

    sediment size distribution based on land use is very crucial in river maintenance. ... a basis for river catchment management study and can be used by river management .... small. In this case, the difference between upstream and downstream ...

  15. Sewage discharges and nutrient levels in Marimba River, Zimbabwe ...

    African Journals Online (AJOL)

    Sewage discharges and nutrient levels in Marimba River, Zimbabwe. ... Population distribution, land-use, industrial activity, urban agricultural ... River, one of the major inflow rivers into the Lake Chivero, Harare city\\'s main water supply source.

  16. River classification is important for reporting ecological status and ...

    African Journals Online (AJOL)

    River classification is important for reporting ecological status and for the general ecological management of river systems by partitioning natural variability. A priori river classification by abiotic variables and validation of classifications obtained.

  17. Inputs from Indian rivers to the ocean: A synthesis

    Digital Repository Service at National Institute of Oceanography (India)

    DileepKumar, M.; George, M.D.; SenGupta, R.

    ). Fluxes of chemical substances to the Indian Ocean from these rivers are computed to a first approximation. The major ion contents are inversely proportional to the river runoff especially for the rivers entering the Arabian Sea. On an average Indian...

  18. Risk Factors for Obesity at Age 3 in Alaskan Children, Including the Role of Beverage Consumption: Results from Alaska PRAMS 2005-2006 and Its Three-Year Follow-Up Survey, CUBS, 2008-2009

    Science.gov (United States)

    Wojcicki, Janet M.; Young, Margaret B.; Perham-Hester, Katherine A.; de Schweinitz, Peter; Gessner, Bradford D.

    2015-01-01

    Background Prenatal and early life risk factors are associated with childhood obesity. Alaska Native children have one of the highest prevalences of childhood obesity of all US racial/ethnic groups. Methods Using the Pregnancy Risk Assessment Monitoring System (PRAMS) and the follow-up survey at 3 years of age (CUBS), we evaluated health, behavioral, lifestyle and nutritional variables in relation to obesity (95th percentile for body mass index (BMI)) at 3 years of age. Multivariate logistic regression modeling was conducted using Stata 12.0 to evaluate independent risk factors for obesity in non-Native and Alaska Native children. Results We found an obesity prevalence of 24.9% in all Alaskan and 42.2% in Alaska Native 3 year olds. Among Alaska Native children, obesity prevalence was highest in the Northern/Southwest part of the state (51.6%, 95%CI (42.6-60.5)). Independent predictive factors for obesity at age 3 years in Alaska non-Native children were low income (obesity (OR 2.01, 95%CI 1.01-4.01) and longer duration of breastfeeding was protective (OR 0.95, 95%CI 0.91-0.995). Among Alaska Native children, predictive factors were witnessing domestic violence/abuse as a 3 year-old (OR 2.28, 95%CI 1.17-7.60). Among obese Alaska Native children, there was an increased daily consumption of energy dense beverages in the Northern/Southwest region of the state, which may explain higher rates of obesity in this part of the state. Conclusions The high prevalence of obesity in Alaska Native children may be explained by differences in lifestyle patterns and food consumption in certain parts of the state, specifically the Northern/Southwest region, which have higher consumption of energy dense beverages. PMID:25793411

  19. Elk River Watershed - Flood Study

    Science.gov (United States)

    Barnes, C. C.; Byrne, J. M.; MacDonald, R. J.; Lewis, D.

    2014-12-01

    Flooding has the potential to cause significant impacts to economic activities as well as to disrupt or displace populations. Changing climate regimes such as extreme precipitation events increase flood vulnerability and put additional stresses on infrastructure. Potential flooding from just under 100 (2009 NPRI Reviewed Facility Data Release, Environment Canada) toxic tailings ponds located in Canada increase risk to human safety and the environment. One such geotechnical failure spilt billions of litres of toxic tailings into the Fraser River watershed, British Columbia, when a tailings pond dam breach occurred in August 2014. Damaged and washed out roadways cut access to essential services as seen by the extensive floods that occurred in Saskatchewan and Manitoba in July 2014, and in Southern Alberta in 2013. Recovery efforts from events such as these can be lengthy, and have substantial social and economic impacts both in loss of revenue and cost of repair. The objective of this study is to investigate existing conditions in the Elk River watershed and model potential future hydrological changes that can increase flood risk hazards. By analyzing existing hydrology, meteorology, land cover, land use, economic, and settlement patterns a baseline is established for existing conditions in the Elk River watershed. Coupling the Generate Earth Systems Science (GENESYS) high-resolution spatial hydrometeorological model with flood hazard analysis methodology, high-resolution flood vulnerability base line maps are created using historical climate conditions. Further work in 2015 will examine possible impacts for a range of climate change and land use change scenarios to define changes to future flood risk and vulnerability.

  20. Flood of August 24–25, 2016, Upper Iowa River and Turkey River, northeastern Iowa

    Science.gov (United States)

    Linhart, S. Mike; O'Shea, Padraic S.

    2018-02-05

    Major flooding occurred August 24–25, 2016, in the Upper Iowa River Basin and Turkey River Basin in northeastern Iowa following severe thunderstorm activity over the region. About 8 inches of rain were recorded for the 24-hour period ending at 4 p.m., August 24, at Decorah, Iowa, and about 6 inches of rain were recorded for the 24-hour period ending at 7 a.m., August 24, at Cresco, Iowa, about 14 miles northwest of Spillville, Iowa. A maximum peak-of-record discharge of 38,000 cubic feet per second in the Upper Iowa River at streamgage 05388250 Upper Iowa River near Dorchester, Iowa, occurred on August 24, 2016, with an annual exceedance-probability range of 0.2–1 percent. High-water marks were measured at six locations along the Upper Iowa River between State Highway 26 near the mouth at the Mississippi River and State Highway 76 about 3.5 miles south of Dorchester, Iowa, a distance of 15 river miles. Along the profiled reach of the Turkey River, a maximum peak-of-record discharge of 15,300 cubic feet per second at streamgage 05411600 Turkey River at Spillville, Iowa, occurred on August 24, 2016, with an annual exceedance-probability range of 1–2 percent. A maximum peak discharge of 35,700 cubic feet per second occurred on August 25, 2016, along the profiled reach of the Turkey River at streamgage 05411850 Turkey River near Eldorado, Iowa, with an annual exceedance-probability range of 0.2–1 percent. High-water marks were measured at 11 locations along the Turkey River between County Road B64 in Elgin and 220th Street, located about 4.5 miles northwest of Spillville, Iowa, a distance of 58 river miles. The high-water marks were used to develop flood profiles for the Upper Iowa River and Turkey River.

  1. Nitrogen and phosphorus in the Upper Mississippi River: Transport, processing, and effects on the river ecosystem

    Science.gov (United States)

    Houser, J.N.; Richardson, W.B.

    2010-01-01

    Existing research on nutrients (nitrogen and phosphorus) in the Upper Mississippi River (UMR) can be organized into the following categories: (1) Long-term changes in nutrient concentrations and export, and their causes; (2) Nutrient cycling within the river; (3) Spatial and temporal patterns of river nutrient concentrations; (4) Effects of elevated nutrient concentrations on the river; and (5) Actions to reduce river nutrient concentrations and flux. Nutrient concentration and flux in the Mississippi River have increased substantially over the last century because of changes in land use, climate, hydrology, and river management and engineering. As in other large floodplain rivers, rates of processes that cycle nitrogen and phosphorus in the UMR exhibit pronounced spatial and temporal heterogeneity because of the complex morphology of the river. This spatial variability in nutrient processing creates clear spatial patterns in nutrient concentrations. For example, nitrate concentrations generally are much lower in off-channel areas than in the main channel. The specifics of in-river nutrient cycling and the effects of high rates of nutrient input on UMR have been less studied than the factors affecting nutrient input to the river and transport to the Gulf of Mexico, and important questions concerning nutrient cycling in the UMR remain. Eutrophication and resulting changes in river productivity have only recently been investigated the UMR. These recent studies indicate that the high nutrient concentrations in the river may affect community composition of aquatic vegetation (e. g., the abundance of filamentous algae and duckweeds), dissolved oxygen concentrations in off-channel areas, and the abundance of cyanobacteria. Actions to reduce nutrient input to the river include changes in land-use practices, wetland restoration, and hydrological modifications to the river. Evidence suggests that most of the above methods can contribute to reducing nutrient concentration in

  2. Radio cobalt in French rivers

    International Nuclear Information System (INIS)

    Lambrechts, A.; Baudin-Jaulent, Y.

    1996-01-01

    The isotopes 58 and 60 of cobalt present in liquid wastes from nuclear plants or from fuel reprocessing plant of Marcoule are fixed in the different compartments of French rivers. The activity levels of radio-cobalt vary according to the sampled compartments nature (bryophyta > immersed plants > sediment > fish). Elsewhere, laboratory experimentations show that the contamination of fish occurs essentially from the water way rather than from food. Cobalt is mainly fixed by kidneys; muscles is no more than 30 % of the total fish activity. (author)

  3. Savannah River Site dose control

    International Nuclear Information System (INIS)

    Smith, L.S.

    1992-01-01

    Health physicists from the Brookhaven National Laboratory (BNL) visited the Savannah River Site (SRS) as one of 12 facilities operated by the Department of Energy (DOE) contractors with annual collective dose equivalents greater than 100 person-rem (100 person-cSv). Their charter was to review, evaluate and summarize as low as reasonably achievable (ALARA) techniques, methods and practices as implemented. This presentation gives an overview of the two selected ALARA practices implemented at the SRS: Administrative Exposure Limits and Goal Setting. These dose control methods are used to assure that individual and collective occupational doses are ALARA and within regulatory limits

  4. Inundation risk for embanked rivers

    Directory of Open Access Journals (Sweden)

    W. G. Strupczewski

    2013-08-01

    Full Text Available The Flood Frequency Analysis (FFA concentrates on probability distribution of peak flows of flood hydrographs. However, examination of floods that haunted and devastated the large parts of Poland lead us to revision of the views on the assessment of flood risk of Polish rivers. It turned out that flooding is caused not only by the overflow of the levee crest but also due to the prolonged exposure to high water on levees structure causing dangerous leaks and breaches that threaten their total destruction. This is because the levees are weakened by long-lasting water pressure and as a matter of fact their damage usually occurs after the culmination has passed the affected location. The probability of inundation is the total of probabilities of exceeding embankment crest by flood peak and the probability of washout of levees. Therefore, in addition to the maximum flow one should also consider the duration of high waters in a river channel. In the paper the new two-component model of flood dynamics: "Duration of high waters–Discharge Threshold–Probability of non-exceedance" (DqF, with the methodology of its parameter estimation was proposed as a completion to the classical FFA methods. Such a model can estimate the duration of stages (flows of an assumed magnitude with a given probability of exceedance. The model combined with the technical evaluation of the probability of levee breaches due to the duration (d of flow above alarm stage gives the annual probability of inundation caused by the embankment breaking. The results of theoretical investigation were illustrated by a practical example of the model implementation to the series of daily flow of the Vistula River at Szczucin. Regardless of promising results, the method of risk assessment due to prolonged exposure of levees to high water is still in its infancy despite its great cognitive potential and practical importance. Therefore, we would like to point out the need for and usefulness of

  5. The travail of River Bend

    International Nuclear Information System (INIS)

    Studness, C.M.

    1990-01-01

    This article looks at the attempts by Gulf States Utilities to get the River Bend Nuclear Plant into its rate base. The review begins with the initial filing of rate cases in Texas and Louisiana in 1986 and continues through many court cases and appeals all the way to the Texas Supreme Court. The preferred and preference shareholders now nominally control the company through election of 10 of 15 members of the company's board of directors. This case is used as an argument for deregulation in favor of competition

  6. Human impacts on river water quality- comparative research in the catchment areas of the Tone River and the Mur River-

    Science.gov (United States)

    Kogure, K.

    2013-12-01

    Human activities in river basin affect river water quality as water discharges into river with pollutant after we use it. By detecting pollutants source, pathway, and influential factor of human activities, it will be possible to consider proper river basin management. In this study, material flow analysis was done first and then nutrient emission modeling by MONERIS was conducted. So as to clarify land use contribution and climate condition, comparison of Japanese and European river basin area has been made. The model MONERIS (MOdelling Nutrient Emissions in RIver Systems; Behrendt et al., 2000) was applied to estimate the nutrient emissions in the Danube river basin by point sources and various diffuse pathways. Work for the Mur River Basin in Austria was already carried out by the Institute of Water Quality, Resources and Waste Management at the Vienna University of Technology. This study treats data collection, modelling for the Tone River in Japan, and comparative analysis for these two river basins. The estimation of the nutrient emissions was carried out for 11 different sub catchment areas covering the Tone River Basin for the time period 2000 to 2006. TN emissions into the Tone river basin were 51 kt/y. 67% was via ground water and dominant for all sub catchments. Urban area was also important emission pathway. Human effect is observed in urban structure and agricultural activity. Water supply and sewer system make urban water cycle with pipeline structure. Excess evapotranspiration in arable land is also influential in water cycle. As share of arable land is 37% and there provides agricultural products, it is thought that N emission from agricultural activity is main pollution source. Assumption case of 10% N surplus was simulated and the result was 99% identical to the actual. Even though N surplus reduction does not show drastic impact on N emission, it is of importance to reduce excess of fertilization and to encourage effective agricultural activity

  7. Hydrogeological investigations of river bed clogging at a river bank filtration site along the River Warta, Poland

    Directory of Open Access Journals (Sweden)

    Przybyłek Jan

    2017-12-01

    Full Text Available River bank filtration (RBF is a system that enriches groundwater resources by induced infiltration of river water to an aquifer. Problematic during operation of RBF systems is the deterioration of infiltration effectiveness caused by river bed clogging. This situation was observed in the Krajkowo well field which supplies fresh water to the city of Poznań (Poland during and after the long hydrological drought between the years 1989 and 1992. The present note discusses results of specific hydrogeological research which included drilling of a net of boreholes to a depth of 10 m below river bottom (for sediment sampling as well as for hydrogeological measurements, analyses of grain size distribution and relative density studies. The results obtained have allowed the recognition of the origin of the clogging processes, as well as the documentation of the clogged parts of the river bottom designated for unclogging activities.

  8. Balancing hydropower production and river bed incision in operating a run-of-river hydropower scheme along the River Po

    Science.gov (United States)

    Denaro, Simona; Dinh, Quang; Bizzi, Simone; Bernardi, Dario; Pavan, Sara; Castelletti, Andrea; Schippa, Leonardo; Soncini-Sessa, Rodolfo

    2013-04-01

    Water management through dams and reservoirs is worldwide necessary to support key human-related activities ranging from hydropower production to water allocation, and flood risk mitigation. Reservoir operations are commonly planned in order to maximize these objectives. However reservoirs strongly influence river geomorphic processes causing sediment deficit downstream, altering the flow regime, leading, often, to process of river bed incision: for instance the variations of river cross sections over few years can notably affect hydropower production, flood mitigation, water supply strategies and eco-hydrological processes of the freshwater ecosystem. The river Po (a major Italian river) has experienced severe bed incision in the last decades. For this reason infrastructure stability has been negatively affected, and capacity to derive water decreased, navigation, fishing and tourism are suffering economic damages, not to mention the impact on the environment. Our case study analyzes the management of Isola Serafini hydropower plant located on the main Po river course. The plant has a major impact to the geomorphic river processes downstream, affecting sediment supply, connectivity (stopping sediment upstream the dam) and transport capacity (altering the flow regime). Current operation policy aims at maximizing hydropower production neglecting the effects in term of geomorphic processes. A new improved policy should also consider controlling downstream river bed incision. The aim of this research is to find suitable modeling framework to identify an operating policy for Isola Serafini reservoir able to provide an optimal trade-off between these two conflicting objectives: hydropower production and river bed incision downstream. A multi-objective simulation-based optimization framework is adopted. The operating policy is parameterized as a piecewise linear function and the parameters optimized using an interactive response surface approach. Global and local

  9. Compromised Rivers: Understanding Historical Human Impacts on Rivers in the Context of Restoration

    Directory of Open Access Journals (Sweden)

    Ellen Wohl

    2005-12-01

    Full Text Available A river that preserves a simplified and attractive form may nevertheless have lost function. Loss of function in these rivers can occur because hydrologic and geomorphic processes no longer create and maintain the habitat and natural disturbance regimes necessary for ecosystem integrity. Recognition of compromised river function is particularly important in the context of river restoration, in which the public perception of a river's condition often drives the decision to undertake restoration as well as the decision about what type of restoration should be attempted. Determining the degree to which a river has been altered from its reference condition requires a knowledge of historical land use and the associated effects on rivers. Rivers of the Front Range of the Colorado Rocky Mountains in the United States are used to illustrate how historical land uses such as beaver trapping, placer mining, tie drives, flow regulation, and the construction of transportation corridors continue to affect contemporary river characteristics. Ignorance of regional land use and river history can lead to restoration that sets unrealistic goals because it is based on incorrect assumptions about a river's reference condition or about the influence of persistent land-use effects.

  10. Exploring Controls on Sinuousity, Terraces and River Capture in the Upper Dajia River, Taiwan

    Science.gov (United States)

    Belliveau, L. C.; Ouimet, W. B.; Chan, Y. C.; Byrne, T. B.

    2015-12-01

    Taiwan is one of the most tectonically active regions in the world and is prone to landslides due to steep topography, large earthquakes and frequent typhoons. Landslides often affect and alter the river valleys beneath them, producing knickpoints on longitudinal river profiles, segmenting valleys into mixed bedrock-alluvial rivers and affecting river incision for tens to thousands of years. This study investigates the origin and evolution of complex channel morphologies, terraces and river capture along a 20km stretch of the Upper Da-Jia River in the Heping area of Taiwan. Through GIS analysis and field studies, we explore controls on river channel sinuousity, terrace development and river capture in relation to tectonic and climatic forcing, rock erodibility and landslides. High channel sinuousity is proposed as the result of a coupling between bank erosion and landslides. We discuss three types of landslide-induced meanders and increased sinuousity: (a) depositional-push meanders, (b) failure-zone erosional meanders, and (c) complex-erosional meanders. We also investigate spatial variation in channel morphology (slope, width) and the distribution and heights of river terraces within the Upper Da-Jia watershed associated with periods of widespread valley filling from landslide activity. Examples of river capture provide further evidence of the dynamic interactions between river incision, landslides and associated changes in channel morphology and terrace development within steep rapidly uplift, eroding and evolving mountain belts.

  11. South Fork Holston River basin 1988 biomonitoring

    Energy Technology Data Exchange (ETDEWEB)

    Saylor, C.F.; Ahlstedt, S.A.

    1990-06-01

    There is concern over the effects of shifts in land use use practices on the aquatic fauna of streams in the South Fork Holston River basin in northwestern North Carolina and southwestern Virginia. Trout reproduction has noticeably declined in the Watauga River subbasin. The Watauga River and Elk River subbasins have been subjected to commercial and resort development. The Middle fork Holston River and the upper South Fork Holston River subbasins have been affected by agricultural and mining activities, respectively (Cox, 1986). To aid reclamation and management of the South Fork Holston basin, Tennessee Valley Authority (TVA) biologists conducted biomonitoring--including index of biotic integrity and macroinvertebrate sampling--on the Middle Fork Holston, South Fork Holston, Watauga, and Elk Rivers to assess cumulative impairment related to changes in habitat and pollutant loading in these subbasins. Biomonitoring can detect environmental degradation, help document problem areas, and assist in development of strategies for managing water quality. This report discusses the methods and materials and results of the biomonitoring of South Fork Holston River Basin. 13 refs., 5 figs., 12 tabs.

  12. Limnology of the Touw River floodplain

    CSIR Research Space (South Africa)

    Allanson, BR

    1983-12-01

    Full Text Available stream_source_info THE LIMNOLOGY OF THE TOUW RIVER FLOODPLAIN.pdf.txt stream_content_type text/plain stream_size 41 Content-Encoding ISO-8859-1 stream_name THE LIMNOLOGY OF THE TOUW RIVER FLOODPLAIN.pdf.txt Content-Type text.../plain; charset=ISO-8859-1 ...

  13. 33 CFR 117.1087 - Fox River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Fox River. 117.1087 Section 117.1087 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Wisconsin § 117.1087 Fox River. (a) The draws of the Canadian...

  14. Determination of characteristics maximal runoff Mountain Rivers

    African Journals Online (AJOL)

    Ovcharuk V and Todorova O

    Odessa State Environmental University, Ukraine. Received: 03 December 2015 / Accepted: 23 April 2016 / Published online: 01 May 2016. ABSTRACT. This article has been examined maximum runoff of the rivers of the Crimean Mountains. The rivers flow through the western and eastern part of the northern slope Crimean ...

  15. Vocal behaviour of Orange River Francolin Scleroptila ...

    African Journals Online (AJOL)

    Fieldwork to study the vocal behaviour of Orange River Francolin Scleroptilia levaillantoides was conducted on a farm in the Heidelberg district, Gauteng province, South Africa, during August 2009 to March 2011. Orange River Francolins possess a basic repertoire of seven calls and one mechanical sound. From 83 ...

  16. 33 CFR 117.385 - Snake River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Snake River. 117.385 Section 117.385 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Idaho § 117.385 Snake River. The drawspan of the U.S. 12 bridge...

  17. Advances in understanding river-groundwater interactions

    Science.gov (United States)

    Brunner, Philip; Therrien, René; Renard, Philippe; Simmons, Craig T.; Franssen, Harrie-Jan Hendricks

    2017-09-01

    River-groundwater interactions are at the core of a wide range of major contemporary challenges, including the provision of high-quality drinking water in sufficient quantities, the loss of biodiversity in river ecosystems, or the management of environmental flow regimes. This paper reviews state of the art approaches in characterizing and modeling river and groundwater interactions. Our review covers a wide range of approaches, including remote sensing to characterize the streambed, emerging methods to measure exchange fluxes between rivers and groundwater, and developments in several disciplines relevant to the river-groundwater interface. We discuss approaches for automated calibration, and real-time modeling, which improve the simulation and understanding of river-groundwater interactions. Although the integration of these various approaches and disciplines is advancing, major research gaps remain to be filled to allow more complete and quantitative integration across disciplines. New possibilities for generating realistic distributions of streambed properties, in combination with more data and novel data types, have great potential to improve our understanding and predictive capabilities for river-groundwater systems, especially in combination with the integrated simulation of the river and groundwater flow as well as calibration methods. Understanding the implications of different data types and resolution, the development of highly instrumented field sites, ongoing model development, and the ultimate integration of models and data are important future research areas. These developments are required to expand our current understanding to do justice to the complexity of natural systems.

  18. Savannah River Site Environmental Report for 1998

    Energy Technology Data Exchange (ETDEWEB)

    Arnett, M

    1999-06-09

    The mission at the Savannah River Site (SRS) is focused primarily on support of the national defense, nonproliferation, and environmental cleanup. SRS-through its prime operating contractor, Westinghouse Savannah River Company-continues to maintain a comprehensive environmental monitoring program.

  19. Climate influences on Vaal River flow

    African Journals Online (AJOL)

    2016-04-02

    Apr 2, 2016 ... enriched NW-cloud bands over the Vaal River catchment, during the flood case study of January 2010. Comparison of. (Pacific) Southern Oscillation and east Atlantic influence on Vaal River discharge reveals the former drives evaporative losses while the latter provides an advance warning of flow ...

  20. Thinking big: linking rivers to landscapes

    Science.gov (United States)

    Joan O’Callaghan; Ashley E. Steel; Kelly M. Burnett

    2012-01-01

    Exploring relationships between landscape characteristics and rivers is an emerging field, enabled by the proliferation of satellite date, advances in statistical analysis, and increased emphasis on large-scale monitoring. Landscapes features such as road networks, underlying geology, and human developments, determine the characteristics of the rivers flowing through...