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Sample records for alaskan coastal current

  1. ERTS imagery applied to Alaskan coastal problems. [surface water circulation

    NASA Technical Reports Server (NTRS)

    Wright, F. F.; Sharma, G. D.; Burbank, D. C.; Burns, J. J.

    1974-01-01

    Along the Alaska coast, surface water circulation is relatively easy to study with ERTS imagery. Highly turbid river water, sea ice, and fluvial ice have proven to be excellent tracers of the surface waters. Sea truth studies in the Gulf of Alaska, Cook Inlet, Bristol Bay, and the Bering Strait area have established the reliability of these tracers. ERTS imagery in the MSS 4 and 5 bands is particularly useful for observing lower concentrations of suspended sediment, while MSS 6 data is best for the most concentrated plumes. Ice features are most clearly seen on MSS 7 imagery; fracture patterns and the movement of specific floes can be used to map circulation in the winter when runoff is restricted, if appropriate allowance is made for wind influence. Current patterns interpreted from satellite data are only two-dimensional, but since most biological activity and pollution are concentrated near the surface, the information developed can be of direct utility. Details of Alaska inshore circulation of importance to coastal engineering, navigation, pollution studies, and fisheries development have been clarified with satellite data. ERTS has made possible the analysis of circulation in many parts of the Alaskan coast.

  2. Organic Carbon Sources in Coastal Southeast Alaskan Streams

    NASA Astrophysics Data System (ADS)

    Hood, E.; Edwards, R. T.; D'Amore, D. V.; Lange, B. J.

    2003-12-01

    Dissolved organic matter (DOM) is abundant in southeast Alaskan watersheds and plays an important role in the biological and physical processes in these aquatic systems. Nearly 30% of the land area in southeast Alaska is classified as wetlands, a large proportion of which are peatlands. Peatlands are thought to provide substantial DOM to surface waters. Another important source of carbon to streams is spawning anadromous salmon. This study examines how streamwater concentrations of DOC are influenced by 1) catchments soils and vegetation, particularly wetland extent and 2) the presence or absence of anadromous fish. Our goal is to characterize the quantity and quality of different DOM sources and to develop an understanding of how these sources influence seasonal trends in streamwater DOM in coastal freshwater systems in southeast Alaska. Surface water and well samples were collected on two contrasting streams near Juneau, Alaska: Peterson Creek, a brownwater, high-carbon stream in a wetland-dominated catchment and McGinnis Creek, a clearwater stream draining upland spruce forest and alpine tundra. Both streams have runs of pink, coho, and chum salmon from July-September. Streamwater DOC concentrations on Peterson Creek averaged 5-6 mg C L-1 during the early summer and increased to 8-12 mg C L-1 during late July and August. Streamwater DOC concentrations on McGinnis Creek were typically less than 1 mg C L-1 during the early summer but increased dramatically to 4-9 mg C L-1 during spates in August. Well samples collected upslope from the streamwater sampling sites on Peterson and McGinnis Creeks had a similar range in DOC concentrations (10-40 mg C L-1), however the wells on McGinnis Creek showed much higher seasonal variability. Our initial results suggest that the seasonal increase in DOC in both streams is primarily associated with the flushing of soluble organic carbon from catchment soils by late summer rains. However, leaching of DOC from salmon carcasses may

  3. Studies of the Northern Alaskan Coastal System: Ongoing project work and synthesis activities

    NASA Astrophysics Data System (ADS)

    Douglas, T. A.; Sturm, M.; Ashjian, C. J.; Jorgensen, T.; Oechel, W. C.; Ping, C.; Rhew, R. C.; Stieglitz, M.

    2006-12-01

    Six ongoing projects focus on a better understanding of processes occurring along the Arctic Alaskan Coast. These projects, grouped as "Studies of the Northern Alaskan Coastal System", or SNACS, combine field, laboratory, modeling and human dimensions research. They include: 1) an investigation of climate variability, ocean processes, sea ice, bowhead whales, and Inupiat subsistence whaling, 2) research on the impact of variability within the ocean and atmosphere on terrestrial fluxes of carbon dioxide, dissolved organic matter and energy, 3) an inventory and description of soil organic carbon fluxes and ground ice in the coastal environment, 4) a determination of whether arctic coastal terrestrial ecosystems are significant sources or sinks of atmospheric methyl halides, chloroform and methane, 5) development of generalized discharge- constituent relationships for arctic basins, and 6) an investigation of the processes controlling mercury deposition to the coastal system. Three broad themes unite the projects: 1) nutrient fluxes from rivers and shoreline erosion in the Arctic coastal zone, 2) impacts of cryospheric changes on the Alaskan Arctic Coast, and 3) potential rapid regime shifts controlled by atmospheric and meteorological processes that could affect the Alaskan Arctic Coast. Warming of the Arctic, particularly its impact on sea ice and nutrient transport in arctic rivers is already affecting fundamental coastal system processes. The six SNACS projects are helping to understand how these impacts will evolve and what their ramifications will be both within and outside of the Arctic.

  4. The influence of the Alaskan Gyre on the coastal circulation in the Gulf of Alaska

    NASA Technical Reports Server (NTRS)

    Heim, Paul K., II; Johnson, Mark A.; O'Brien, James J.

    1992-01-01

    The circulation of the northeast Pacific Ocean and the Gulf of Alaska is simulated by means of a reduced-gravity wind-driven model to study seasonal and interannual flow variability. The circulation in the NE Pacific is discussed emphasizing its ramifications for the physical domain, equations, and boundary conditions of the numerical model. The pseudostress fields used to drive the model are based on 20 years of data from the Comprehensive Ocean-Atmosphere Data Set and are analyzed with empirical orthogonal function analysis. The monthly stresses from 1986-89 are used to drive the model, and regional oceanographic features are reproduced including the Alaskan Gyre, Coastal Current, the Sitka eddy, and a severe cyclonic eddy. Comparisons with experimental data show that the high-resolution baroclinic model is valid and demonstrates the applicability of reduced-gravity models.

  5. Alder Expansion as a Coastal Warming Signal - Linking Coastal Alaskan Carbon to Vegetation Change with Climate

    NASA Astrophysics Data System (ADS)

    Peteet, D. M.; Nichols, J. E.; Moy, C. M.; McGeachy, A.

    2014-12-01

    Corser Bog (60.5296364oN, 145.453858oW), 21 km east of Cordova, AK is a sphagnum-dominated peatland 42 m asl. adjacent to Sheridan Glacier and the Copper River Delta. Deglaciation at 11.5 ka began with shallow pond deposition, reflecting regional warmth with the pioneers Alnus crispa subsp. sinuata, Salix, and ferns colonizing the fresh, mineral soils on the landscape. Continued early Holocene warming/melting of glaciers led to the foundation species Alnus dominance and peatland formation, surrounded by shrubs such as Rubus spectabilis, Sambucus racemosa, and wetland species such as Myrica gale and Potentilla palustris. As Sphagnum peat accumulated, the highest rates of carbon accumulation for a few centuries are represented at 50 g/m2/a, similar to short-term very high rates in the early Holocene throughout the circumboreal region but varying within the early Holocene due to development of local wet, bryophytic environments. A shift to sedge peat regionally along the South-Central Alaskan coast 7.6 - 3.7 ka is paralleled by a more evaporative, drier climate with Rhododendron groenlandicum presence, lower carbon accumulation (13 g/m2/a), and minimal macrofossil preservation, which is paralleled regionally in coastal muskegs both to the northwest and southeast and by a hiatus in a nearby lake record. A cooler, moister climate is evident in Corser Bog with the shift to Sphagnum peat at 3.7 ka, regional shifts from sedge to Sphagnum peat throughout the entire coastline from Yakutat to Girdwood, AK and the demonstration of glacial advances in the region. Alnus pollen markedly increases to 60% in the uppermost sample, indicative of a major signal for glacial recession in this region.

  6. Chemical and in vitro assessment of Alaskan coastal vegetation antioxidant capacity.

    PubMed

    Kellogg, Joshua; Lila, Mary Ann

    2013-11-20

    Alaska Native (AN) communities have utilized tidal plants and marine seaweeds as food and medicine for generations, yet the bioactive potential of these resources has not been widely examined. This study screened six species of Alaskan seaweed ( Fucus distichus , Saccharina latissima , Saccharina groenlandica , Alaria marginata , Pyropia fallax , and Ulva lactuca ) and one tidal plant ( Plantago maritima ) for antioxidant activity. Total polyphenolic content (TPC) was determined, and chemical antioxidant capacity was assessed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, ferrous ion chelating, and nitric oxide (NO) inhibition assays. In vitro inhibition of radical oxygen species (ROS) generation and NO synthesis was evaluated in a RAW 264.7 macrophage culture. Greatest TPC (557.2 μg phloroglucinol equivalents (PGE)/mg extract) was discovered in the ethyl acetate fraction of F. distichus, and highest DDPH scavenging activity was exhibited by F. distichus and S. groenlandica fractions (IC50 = 4.29-5.12 μg/mL). These results support the potential of Alaskan coastal vegetation, especially the brown algae, as natural sources of antioxidants for preventing oxidative degeneration and maintaining human health. PMID:24147955

  7. Alaskan Peninsula Cenozoic stratigraphy: stratigraphic sequences and current research

    SciTech Connect

    Allison, R.C.; Armentrout, J.M.

    1985-04-01

    Geology of the Alaska Peninsula-Island Arc and Continental Margin, by C.A. Burk, is the principal reference for stratigraphic studies on the Alaska Peninsula. Burk mapped the Phanerozoic stratigraphy and provided a geologic history and structural interpretation of the area between Wide Bay and Unimak Island. Cenozoic rocks were mapped as three unconformity-bounded sequences. Recognition of specific formations was difficult due to similarity of lithofacies, isolated outcrops, rapid facies changes, and alteration and burial by young volcanics. Consequently, megafossil assemblages were relied upon to facilitate correlations between study areas. The three unconformity-bounded Cenozoic sequences are: (1) the Paleogene Beaver Bay Group consisting of three formations: the dominantly nonmarine Tolstoi Formation, the dominantly marine Stepovak Formation, and the volcanic Meshik Formation. Current work suggests these units are at least in part coeval facies of late Paleocene through Oligocene age. (2) The Neogene Bear Lake Formation consisting of the lower Unga Conglomerate Member and an unnamed upper member. Rapid facies changes and incorrect reports of fossil occurrence have resulted in confusion of stratigraphic relationships within this sequence of middle to late Miocene age. (3) A late Neogene informally defined upper sequence consisting of interbedded marginal marine, coastal-plain, and volcanic facies. Current work suggests this sequence is Pliocene through Pleistocene in age.

  8. Modeling of Dense Water Production and Salt Transport from Alaskan Coastal Polynyas

    NASA Technical Reports Server (NTRS)

    Signorini, Sergio R.; Cavalieri, Donald J.

    2000-01-01

    The main significance of this paper is that a realistic, three-dimensional, high-resolution primitive equation model has been developed to study the effects of dense water formation in Arctic coastal polynyas. The model includes realistic ambient stratification, realistic bottom topography, and is forced by time-variant surface heat flux, surface salt flux, and time-dependent coastal flow. The salt and heat fluxes, and the surface ice drift, are derived from satellite observations (SSM/I and NSCAT sensors). The model is used to study the stratification, salt transport, and circulation in the vicinity of Barrow Canyon during the 1996/97 winter season. The coastal flow (Alaska coastal current), which is an extension of the Bering Sea throughflow, is formulated in the model using the wind-transport regression. The results show that for the 1996/97 winter the northeastward coastal current exports 13% to 26% of the salt produced by coastal polynyas upstream of Barrow Canyon in 20 to 30 days. The salt export occurs more rapidly during less persistent polynyas. The inclusion of ice-water stress in the model makes the coastal current slightly weaker and much wider due to the combined effects of surface drag and offshore Ekman transport.

  9. InSAR detects possible thaw settlement in the Alaskan Arctic Coastal Plain

    USGS Publications Warehouse

    Rykhus, R.P.; Lu, Zhiming

    2008-01-01

    Satellite interferometric synthetic aperture radar (InSAR) has proven to be an effective tool for monitoring surface deformation from volcanoes, earthquakes, landslides, and groundwater withdrawal. This paper seeks to expand the list of applications of InSAR data to include monitoring subsidence possibly associated with thaw settlement over the Alaskan Arctic Coastal Plain. To test our hypothesis that InSAR data are sufficiently sensitive to detect subsidence associated with thaw settlement, we acquired all Japanese Earth Resources Satellite-1 (JERS-1) L-band data available for the summers of 1996, 1997, and 1998 over two sites on the Alaska North Slope. The least amount of subsidence for both study sites was detected in the interferograms covering the summer of 1996 (2-3 cm), interferograms from 1997 and 1998 revealed that about 3 cm of subsidence occurred at the northern Cache One Lake site, and about 5 cm of subsidence was detected at the southern Kaparuk River site. These preliminary results illustrate the capacity of the L-band (24 cm) wavelength JERS-1 radar data to penetrate the short Arctic vegetation to monitor subsidence possibly associated with thaw settlement of the active layer and (or) other hydrologic changes over relatively large areas. ?? 2008 CASI.

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

    NASA Technical Reports Server (NTRS)

    Cavalieri, Donald J.; Martin, Seelye

    1994-01-01

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

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

    NASA Astrophysics Data System (ADS)

    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

  12. All-weather ice information system for Alaskan arctic coastal shipping

    NASA Technical Reports Server (NTRS)

    Gedney, R. T.; Jirberg, R. J.; Schertler, R. J.; Mueller, R. A.; Chase, T. L.; Kramarchuk, I.; Nagy, L. A.; Hanlon, R. A.; Mark, H.

    1977-01-01

    A near real-time ice information system designed to aid arctic coast shipping along the Alaskan North Slope is described. The system utilizes a X-band Side Looking Airborne Radar (SLAR) mounted aboard a U.S. Coast Guard HC-130B aircraft. Radar mapping procedures showing the type, areal distribution and concentration of ice cover were developed. In order to guide vessel operational movements, near real-time SLAR image data were transmitted directly from the SLAR aircraft to Barrow, Alaska and the U.S. Coast Guard icebreaker Glacier. In addition, SLAR image data were transmitted in real time to Cleveland, Ohio via the NOAA-GOES Satellite. Radar images developed in Cleveland were subsequently facsimile transmitted to the U.S. Navy's Fleet Weather Facility in Suitland, Maryland for use in ice forecasting and also as a demonstration back to Barrow via the Communications Technology Satellite.

  13. Developing New Strategies for Coping with Weather: Work in Alaskan and Canadian Coastal Communities

    NASA Astrophysics Data System (ADS)

    Atkinson, D. E.

    2014-12-01

    A changing climate is manifested at ground level through the day to day weather. For all Northern residents - community, industrial, operational and response - the need to think about the weather is ever present. Northern residents, and in particular, indigenous community residents, fully understand implications of the weather, however, a comment that has been heard more often is that old ways of knowing are not as reliable as they once were. Weather patterns seem less consistent and subject to more rapid fluctuations. Compromised traditional ways of knowing puts those who need to travel or hunt at greater risk. One response to adapt to this emerging reality is to make greater use of western sources of information, such as weather data and charts provided by NOAA's National Weather Service or Environment Canada. The federal weather agencies have very large and complex forecasting regions to cover, and so one problem is that it can be difficult to provide perfectly tailored forecasts, that cover all possible problems, right down to the very local scale in the communities. Only those affected have a complete feel for their own concerns. Thus, key to a strategy to improve the utility of available weather information is a linking of local-scale manifestations of problematic weather to the larger-scale weather patterns. This is done in two ways: by direct consultation with Northern residents, and by installation of equipment to measure parameters of interest to residents, which are not already being measured. This talk will overview projects in coastal Alaska and Canada targeting this objective. The challenge of designing and conducting interviews, and then of harvesting relevant information, will be visited using examples from the three major contexts: coastal community, industrial, and operational. Examples of how local comments can be married to weather products will be presented.

  14. Submesoscale Coastal Ocean Surface Current Variability

    NASA Astrophysics Data System (ADS)

    Shay, L. K.; Peters, H.; Cook, T.; Haus, B.; Martinez, J.

    2004-12-01

    Measurements of coastal ocean surface currents using High Frequency (HF) radars with phased array technology have revealed a broad spectrum of processes. During a series of ONR-sponsored experiments, both HF (16 and 25 MHz) and Very High Frequency (VHF: 50 MHz) radars have revealed energetic, coherent submesoscale processes that are affected by mesoscale currents. Flowing along the coast of southeastern Florida shelf (EFS), the Florida Current (FC) produces an environment of large mean vorticity with embedded, energetic mesoscale and submesocale flow features. These submesoscale features, defined here as flow features with length scales less than the internal deformation radius of 10-40 km, have been observed with an Ocean Surface Current Radar (OSCR) and Wellen Radar (WERA). These features are energetic and coherent over scales of 2 to 20 km. With amplitudes of up to 50 cm s-1, we have limited knowledge of the spectrum of processes within the submesoscale band, of their nature, interaction with other flow scales and energy cascades. Observations in radar and sun glint photos from the space shuttle also indicate that submesoscale vortices and spiral eddies on the free surface are highly nonlinear with Rossby numbers ranging from 5 f to as high as 10 f . These spiral-like images of the surface fields represent a challenge from both fluid dynamical and remote sensing viewpoints as they have a pronounced impact on the surface roughness and backscattered energy. As part of the ONR sponsored SEA-COOS program, a three-station WERA is providing near-real time mapping of the surface velocity field at ~1 km resolution over a range of 100 to 120 km. Sampling intervals range from minutes to hours to help resolve the gradients and high frequency submesoscale motions where RMS differences have been in the 6 to 10 cm s-1 range. Unlike mesoscale features, which are elongated in the along-shelf direction, submesoscale processes tend to be more isotropic with considerable cross

  15. Alaskan Voices.

    ERIC Educational Resources Information Center

    Achatz, Mary, Ed.; Caldera, Debra, Ed.; Saylor, Brian; DeGross, Denny

    This paper examines the attitudes of adults and teenagers in 10 predominantly rural Alaskan communities toward their own health and well-being and that of children and families in their community. The communities were located across the state and ranged in size from populations of under 900 to over 50,000. The proportion of Alaska Natives in the…

  16. Modeling coastal current transport in the Gulf of Maine

    NASA Astrophysics Data System (ADS)

    Hetland, Robert D.; Signell, Richard P.

    2005-09-01

    A numerical simulation of the circulation in the Gulf of Maine is compared with observations taken during the spring and summer of 1994, focusing on two distinct coastal current systems. The eastern Maine coastal current is well mixed out to approximately 50m depth, with the influence of tidal mixing extending to 100m depth. In contrast, the western Maine coastal current consists mainly of a surface-trapped plume emanating from the Kennebec River. Various methods of model/data comparison are discussed, ranging from qualitative comparisons of surface temperature and currents to quantitative measurements of model skill. In particular, one primary metric of comparison is the amount and distribution of fresh water carried within the coastal current systems. In both coastal current systems, fresh-water flux has an approximately self-similar structure so that measurements taken at a single mooring location may be extrapolated to estimate the entire along-shore fresh-water flux. This self-similar structure is shown to be internally consistent within the model, and results in good model/data comparisons. The model has more skill at predicting fresh-water flux than other point-to-point surface property comparisons in all cases except surface salinity in the western Maine coastal current. This suggests fresh-water flux is a robust feature in the model, and a suitable metric for gauging the model ability to reproduce the broad-scale transport of the Maine coastal current system.

  17. Oxygen isotopic identity of the Delaware Coastal Current

    NASA Astrophysics Data System (ADS)

    Khim, Boo-Keun; Krantz, David E.

    1996-07-01

    Results are presented and discussed from a preliminary study on the oxygen isotopic composition of coastal and inner shelf waters from the Middle Atlantic Bight between the mouths of Delaware Bay and Chesapeake Bay. The water samples were collected during the spring, April/May 1993, in conjunction with a detailed hydrographic survey of the Delaware Coastal Current. The relationship between salinity and δ18O, both of which are generally accepted conservative properties of seawater, allows identification of the fresh and saline mixing end-members for the Delaware Coastal Current. The main source of freshwater to the Delaware Coastal Current is a mixture of runoff into Delaware Bay with an estimated δ18OS = 0 composition of -7.08‰. The freshwater input is dominated by Delaware River discharge with a mean δ18O of -8.0‰ based on previous studies; there appears to be a secondary contribution of freshwater that is isotopically heavier from coastal-plain drainage. The extrapolated δ18OS = 32.35 value (-0.93‰) of the saline component implies exchange with Middle Atlantic Bight Shelf Water through along-shelf and across-shelf mixing processes. Limited data suggest that the oxygen isotopic composition of low-salinity water exiting the Chesapeake Bay mouth is discernible compared with that of the Delaware Coastal Current.

  18. A coastal current in winter: Autonomous underwater vehicle observations of the coastal current east of Cape Cod

    NASA Astrophysics Data System (ADS)

    Shcherbina, Andrey Y.; Gawarkiewicz, Glen G.

    2008-07-01

    Evolution of the coastal current structure on the shallow continental shelf east of Cape Cod was studied using autonomous underwater vehicle (AUV) surveys and moored observations during the winters of 2005 and 2006. A coastally bounded plume of relatively fresh water, characteristic of a coastal current, persisted throughout both winters despite strong mixing. Nondimensional parameter analysis classified the plume as a bottom-trapped gravity current over a moderately steep slope, placing it in the context of other buoyant coastal currents. The range of water properties within the coastal current, its spatial extent and temporal variability were characterized on the basis of the data from repeat hydrographic sections. Along-shore freshwater transport was dominated by highly variable barotropic flow driven by local wind and basin-wide pressure gradients. It eventually contributed substantially to the average southward along-shore freshwater transport, estimated at 1.1 ± 0.3 × 103 m3 s-1 in February and 1.8 ± 0.4 × 103 m3 s-1 in the first half of March 2006. The contribution of baroclinic buoyancy-driven freshwater transport was typically an order of magnitude lower during both winters. Despite the relative weakness of the baroclinic freshwater transport, the coastal current potentially had a major impact on water mass modification during the winter. Continual presence of the low-salinity plume prevented the formation of cold dense water near the coast and its export offshore. The coastal current effectively isolated the inner-shelf zone, reducing its potential role in ventilation of the intermediate layers of the Wilkinson Basin of the Gulf of Maine.

  19. Spatial and Temporal Variation in Primary Productivity (NDVI) of Coastal Alaskan Tundra: Decreased Vegetation Growth Following Earlier Snowmelt

    NASA Technical Reports Server (NTRS)

    Gamon, John A.; Huemmrich, K. Fred; Stone, Robert S.; Tweedie, Craig E.

    2015-01-01

    In the Arctic, earlier snowmelt and longer growing seasons due to warming have been hypothesized to increase vegetation productivity. Using the Normalized Difference Vegetation Index (NDVI) from both field and satellite measurements as an indicator of vegetation phenology and productivity, we monitored spatial and temporal patterns of vegetation growth for a coastal wet sedge tundra site near Barrow, Alaska over three growing seasons (2000-2002). Contrary to expectation, earlier snowmelt did not lead to increased productivity. Instead, productivity was associated primarily with precipitation and soil moisture, and secondarily with growing degree days, which, during this period, led to reduced growth in years with earlier snowmelt. Additional moisture effects on productivity and species distribution, operating over a longer time scale, were evident in spatial NDVI patterns associated with microtopography. Lower, wetter regions dominated by graminoids were more productive than higher, drier locations having a higher percentage of lichens and mosses, despite the earlier snowmelt at the more elevated sites. These results call into question the oft-stated hypothesis that earlier arctic growing seasons will lead to greater vegetation productivity. Rather, they agree with an emerging body of evidence from recent field studies indicating that early-season, local environmental conditions, notably moisture and temperature, are primary factors determining arctic vegetation productivity. For this coastal arctic site, early growing season conditions are strongly influenced by microtopography, hydrology, and regional sea ice dynamics, and may not be easily predicted from snowmelt date or seasonal average air temperatures alone. Our comparison of field to satellite NDVI also highlights the value of in-situ monitoring of actual vegetation responses using field optical sampling to obtain detailed information on surface conditions not possible from satellite observations alone.

  20. Structure and variability of the Western Maine Coastal Current

    USGS Publications Warehouse

    Churchill, J.H.; Pettigrew, N.R.; Signell, R.P.

    2005-01-01

    Analyses of CTD and moored current meter data from 1998 and 2000 reveal a number of mechanisms influencing the flow along the western coast of Maine. On occasions, the Eastern Maine Coastal Current extends into the western Gulf of Maine where it takes the form of a deep (order 100 m deep) and broad (order 20 km wide) southwestward flow with geostrophic velocities exceeding 20 cm s -1. This is not a coastally trapped flow, however. In fields of geostrophic velocity, computed from shipboard-CTD data, the core of this current is roughly centered at the 100 m isobath and its onshore edge is no closer than 10 km from the coast. Geostrophic velocity fields also reveal a relatively shallow (order 10 m deep) baroclinic flow adjacent to the coast. This flow is also directed to the southwest and appears to be principally comprised of local river discharge. Analyses of moored current meter data reveal wind-driven modulations of the coastal flow that are consistent with expectations from simple theoretical models. However, a large fraction of the near-shore current variance does not appear to be directly related to wind forcing. Sea-surface temperature imagery, combined with analysis of the moored current meter data, suggests that eddies and meanders within the coastal flow may at times dominate the near-shore current variance. ?? 2005 Elsevier Ltd. All rights reserved.

  1. Structure and variability of the Western Maine Coastal Current

    NASA Astrophysics Data System (ADS)

    Churchill, James H.; Pettigrew, Neal R.; Signell, Richard P.

    2005-09-01

    Analyses of CTD and moored current meter data from 1998 and 2000 reveal a number of mechanisms influencing the flow along the western coast of Maine. On occasions, the Eastern Maine Coastal Current extends into the western Gulf of Maine where it takes the form of a deep (order 100 m deep) and broad (order 20 km wide) southwestward flow with geostrophic velocities exceeding 20 cm s -1. This is not a coastally trapped flow, however. In fields of geostrophic velocity, computed from shipboard-CTD data, the core of this current is roughly centered at the 100 m isobath and its onshore edge is no closer than 10 km from the coast. Geostrophic velocity fields also reveal a relatively shallow (order 10 m deep) baroclinic flow adjacent to the coast. This flow is also directed to the southwest and appears to be principally comprised of local river discharge. Analyses of moored current meter data reveal wind-driven modulations of the coastal flow that are consistent with expectations from simple theoretical models. However, a large fraction of the near-shore current variance does not appear to be directly related to wind forcing. Sea-surface temperature imagery, combined with analysis of the moored current meter data, suggests that eddies and meanders within the coastal flow may at times dominate the near-shore current variance.

  2. A coastal current in winter: 2. Wind forcing and cooling of a coastal current east of Cape Cod

    NASA Astrophysics Data System (ADS)

    Shcherbina, Andrey Y.; Gawarkiewicz, Glen G.

    2008-10-01

    The combined effect of cooling and wind-driven buoyancy flux (WDBF) on a buoyant coastal current east of Cape Cod is investigated using observations and process-oriented numerical modeling. Theoretical considerations show that with the moderately strong surface density gradients observed in the Outer Cape Cod Coastal Current, WDBF can substantially exceed the buoyancy loss due to cooling, especially during intense winter storms. Evidence of deep convection associated with strong negative WDBF during downwelling-favorable winds is clearly seen in the moored observations. A simplified two-dimensional numerical model is used to illustrate the evolution of wind- and buoyancy-driven cross-shelf overturning circulation in response to surface cooling and episodic storm events. The simulation confirms that WDBF plays an important role in driving subduction of cold surface water at the offshore surface outcrop of the coastal current font. The presence of the coastal current is also shown to block onshore Ekman transport. As a result, the downwelling circulation in a cross-shore plane is predicted to have a complex multicell structure, in which exchange between the inner shelf and midshelf is restricted. The downwelling circulation has a major impact on the cross-shelf origin of cold, dense shelf waters contributing to intermediate layers of the Wilkinson Basin of the Gulf of Maine.

  3. Characterizing the Navidad current interannual variability using coastal altimetry

    NASA Astrophysics Data System (ADS)

    Le Hénaff, Matthieu; Roblou, Laurent; Bouffard, Jérôme

    2011-04-01

    In this study, the Navidad current, which flows along the northern coast of Spain in winter, is observed and characterized using coastal altimetry data over the period 1992-2002. This coastal current, marked by a strong interannual variability, is associated with eastward transport of warm waters along the shelf slope. Specific data editing and processing strategies have been applied to the along-track altimeter data, which allows us to retrieve altimetric sea level anomalies closer to the coast, with a better spatial coverage and improved quality when compared with standard altimetric products. The current variability observed upstream by in situ time series after November 1996 is well reproduced by the satellite across-track surface geostrophic current anomalies up until September 1999; this agreement degrades later in time. The combined use of satellite-derived current anomalies and sea-surface temperature anomalies allows us to develop indices of Navidad occurrences, in the first long-term, systematic survey of that current based on a multi-sensor approach. The satellite analyses confirm the previously identified Navidad occurrences in winter of 1995-1996, 1997-1998, and 2000-2001. Furthermore, a weak Navidad event was identified in winter 1996-1997. These four winters are associated with a negative North Atlantic Oscillation index in the previous fall, but the intensity of the Navidad is not correlated to the amplitude of that index.

  4. Drifter observations of the Gulf of Maine Coastal Current

    NASA Astrophysics Data System (ADS)

    Manning, J. P.; McGillicuddy, D. J., Jr.; Pettigrew, N. R.; Churchill, J. H.; Incze, L. S.

    2009-04-01

    Two-hundred and twenty seven satellite-tracked drifters were deployed in the Gulf of Maine (GoM) from 1988 to 2007, primarily during spring and summer. The archive of tracks includes over 100,000 km logged thus far. Statistics such as transit times, mean velocities, response to wind events, and preferred pathways are compiled for various areas of the coastal GoM. We compare Lagrangian flow with Eulerian estimates from nearby moorings and evaluate drifter trajectories using Ekman theory and 3-D ocean circulation models. Results indicate that the Gulf of Maine Coastal Current is a strong and persistent feature centered on the 94±23 m isobath, but that particles: (a) deviate from the seasonal-mean core fairly regularly, and are often re-entrained; (b) follow a slower (9 cm/s), less-constrained path in the western portion off the coast of Maine relative to the eastern (16 cm/s) section; and (c) can be affected by wind events and small-scale baroclinic structures. Residence times calculated for each 1/2° grid cell throughout the GoM depict some regions (Eastern Maine and Western Nova Scotia) as being relatively steady, flow-through systems, while others (Penobscot, Great South Channel) have more variable, branching pathways. Travel times for drifters that are retained within the coastal current along the entire western side of the Gulf of Maine are typically less than two months (55 days).

  5. Changing Chilean coastal currents could drive aquatic evolution

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2012-01-01

    For invertebrate and fish species that spend most of their lives in rich coastal waters rather than migrating freely throughout the open ocean, the formation of island populations and the associated risk of genetic diversity loss are threats to long-term population health. Many species cope through a spawning mechanism whereby larvae are released en masse into near-shore ocean currents, like pollen adrift in the wind. The larvae are viable in open waters from days to months, but only those that find their way back to shore can settle and develop. To increase their chances, different species' larvae often use particular swimming behaviors, for example, varying their depth in the water column throughout the day.

  6. SAR detected river mixing and coastal wave/current difusion

    NASA Astrophysics Data System (ADS)

    Diez, Margarita; Martinez-Benjamin, Juan Jose; Sekula, Emil

    2014-05-01

    The Synthetic Aperture Radar SAR is an active radar which emits its energy in the centimetre frequencies. Due to the large orbital velocity of the satellite (7.5km s-1) approximately, the path of the antenna itself may be converted as a virtual antenna of a much larger size. The SAR instrument may also be installed on a plane, or on a helicopter. The SAR backscattering depends on the roughness of the small scale surface of the ocean. When the surface is rougher (mostly due to capillary waves in the surface) the intensity of the receiving signal is stronger due to Bragg resonant dispersion [1,2] and a white zone is observed in the image when the surface is very rough. Rivers and tensioactive slicks and spills are well detected as dark areas in the ocean surface. An image selection of SAR images in order to identify coastal river plumes or oil spills of more than 1000 ERS-1/2 and RADARSAT Synthetic Aperture Radar SAR images for the test site in the NW Mediterranean seawere clasified and stored by [2,3,7] during the "Clean Seas" International project and the "Marine pollution and surface dynamics in the NW Mediterranean Sea" European Spatial Agency ESA project AO-ID C1P.2240. A geometry of gray scale ranges and boundaries of spatial dynamic surface features may contain new helpful information about the turbulent structure at different distances from the coast. Already we used multi-fractal analysis techniques to investigate man-made oil spills [3-5] We apply these techniques to the analysis of ocean surface multi-fractal features (eddies, mushroom-like currents, etc.) to understand the scale to scale transport and coastal effects. (Redondo et al. 1998)(Diez et al. 2008) [4,7]. The effect of bathymetry and local currents are important in describing the ocean surface behavior. In the NW Mediterranean the maximum eddy size agrees remarkably well with the limit imposed by the local Rossby deformation radius using the usual thermocline induced stratification, the

  7. The East Greenland Coastal Current: Structure, variability, and forcing

    NASA Astrophysics Data System (ADS)

    Sutherland, David A.; Pickart, Robert S.

    2008-07-01

    The subtidal circulation of the southeast Greenland shelf is described using a set of high-resolution hydrographic and velocity transects occupied in summer 2004. The main feature is the East Greenland Coastal Current (EGCC), a low-salinity, high-velocity jet with a wedge-shaped hydrographic structure characteristic of other surface buoyancy-driven currents. The EGCC was observed along the entire Greenland shelf south of Denmark Strait, while the transect north of the strait showed only a weak shelf flow. This observation, in conjunction with water mass considerations and other supporting evidence, suggests that the EGCC is an inner branch of the East Greenland Current (EGC) that forms south of Denmark Strait. It is argued that bathymetric steering is the most likely reason why the EGC apparently bifurcates at this location. Repeat sections occupied at Cape Farewell between 1997 and 2004 show that the alongshelf wind stress can have an influence on the structure and strength of the EGCC and EGC on timescales of 2-3 days. Accounting for the wind-induced effects, the volume transport of the combined EGCC/EGC system is roughly constant (∼2 Sv) over the study domain, from 68°N to Cape Farewell near 60°N. The corresponding freshwater transport increases by roughly 60% over this distance (59-96 mSv, referenced to a salinity of 34.8). This trend is consistent with a simple freshwater budget of the EGCC/EGC system that accounts for meltwater runoff, melting sea-ice and icebergs, and net precipitation minus evaporation.

  8. CLASSIFYING COASTAL WATERS:CURRENT NECESSITY AND HISTORICAL PERSPECTIVE

    EPA Science Inventory

    Coastal ecosystems are ecologically and commercially valuable, productive habitats that are experiencing escalating compromises of their structural and functional integrity. The Clean Water Act (USC 1972) requires identification of impaired water bodies and determination of the c...

  9. Cost of Impressed Current Cathodic Protection for Coastal Oregon Bridges

    SciTech Connect

    Holcomb, Gordon R.; Cryer, Curtis B.

    1998-07-01

    The State of Oregon is using arc-sprayed zinc coatings for anodes in impressed current cathodic protection (ICCP) systems on reinforced concrete coastal bridges. The two lowest bids for four ICCP projects were averaged and converted to 1997 dollars. The total average cost for the ICCP projects was $51.63/ft2 ($555.51/m2) of protected concrete. The cathodic protection part of the ICCP projects average $14.08/ft2 ($151.47/m2), while zinc anode installation cost an average of $7.13/ft2 ($76.67/m2). Oregon's rugged and beautiful coastline is graced with a series of historical arched bridges designed by Conde B. McCullough. McCullough is the internationally recognized architect who designed many of the Oregon Coast Highway (U.S. 101) bridges in the 1920s and 1930s. Many are listed on the National Historic Register. After the expense ($45m) and public outcry associated with the replacement of the historic Alsea Bay Bridge in Waldport, Oregon, the Oregon Department of Transportation began using impressed current cathodic protection (ICCP) to extend the service life of reinforced concrete bridges. Figure 1 visually illustrates the need for such remediation. It shows exposed rebar from underneath the Brush Creek Bridge, which is very representative of the conditions found underneath many coastal Oregon bridges. Four ICCP projects have been funded, put out for bid, and completed. The four projects, their bid closing dates, and their completion dates are the Cape Creek Bridge (1990- 1992), the Yaquina Bay Bridge south arches (1991-1995), the Depoe Bay Bridge (1993-1997), and the Yaquina Bay Bridge south approach (1995-1997). The Cape Creek, Yaquina Bay, and Depoe Bay Bridges are shown in Figs. 2-4. Other ICCP projects are underway on the Oregon coast. In the ICCP systems, arc-sprayed zinc coatings on the concrete surface are anodes that protect the steel rebar. Accelerated laboratory studies at the Albany Research Center have predicted zinc anode service lives of

  10. SAR detected river mixing and coastal wave/current difusion

    NASA Astrophysics Data System (ADS)

    Diez, Margarita; Martinez-Benjamin, Juan Jose; Sekula, Emil

    2014-05-01

    The Synthetic Aperture Radar SAR is an active radar which emits its energy in the centimetre frequencies. Due to the large orbital velocity of the satellite (7.5km s-1) approximately, the path of the antenna itself may be converted as a virtual antenna of a much larger size. The SAR instrument may also be installed on a plane, or on a helicopter. The SAR backscattering depends on the roughness of the small scale surface of the ocean. When the surface is rougher (mostly due to capillary waves in the surface) the intensity of the receiving signal is stronger due to Bragg resonant dispersion [1,2] and a white zone is observed in the image when the surface is very rough. Rivers and tensioactive slicks and spills are well detected as dark areas in the ocean surface. An image selection of SAR images in order to identify coastal river plumes or oil spills of more than 1000 ERS-1/2 and RADARSAT Synthetic Aperture Radar SAR images for the test site in the NW Mediterranean seawere clasified and stored by [2,3,7] during the "Clean Seas" International project and the "Marine pollution and surface dynamics in the NW Mediterranean Sea" European Spatial Agency ESA project AO-ID C1P.2240. A geometry of gray scale ranges and boundaries of spatial dynamic surface features may contain new helpful information about the turbulent structure at different distances from the coast. Already we used multi-fractal analysis techniques to investigate man-made oil spills [3-5] We apply these techniques to the analysis of ocean surface multi-fractal features (eddies, mushroom-like currents, etc.) to understand the scale to scale transport and coastal effects. (Redondo et al. 1998)(Diez et al. 2008) [4,7]. The effect of bathymetry and local currents are important in describing the ocean surface behavior. In the NW Mediterranean the maximum eddy size agrees remarkably well with the limit imposed by the local Rossby deformation radius using the usual thermocline induced stratification, the

  11. Current Measurements and Overwash Monitoring Using Tilt Current Meters in Three Coastal Environments

    NASA Astrophysics Data System (ADS)

    Lowell, N. S.; Sherwood, C. R.; Decarlo, T. M.; Grant, J. R.

    2014-12-01

    Tilt Current Meters (TCMs) provide accurate, cost effective measurements of near-bottom current velocities. Many studies in coastal environments require current measurements, which are frequently made with Acoustic Doppler Profilers (ADPs). ADPs are expensive, however, and may not be suitable for locations where there is significant risk of damage, loss, or theft or where a large spatial array of measurements is required. TCMs, by contrast, are smaller, less expensive, and easier to deploy. This study tested TCMs in three sites to determine their suitability for use in research applications. TCMs are based on the drag-tilt principle, where the instrument tilts in response to current. The meter consists of a buoyant float with an onboard accelerometer, three-axis tilt sensor, three-axis magnetometer (compass), and a data logger. Current measurements are derived by post processing the tilt and compass values and converting them to velocity using empirical calibration data. Large data-storage capacity (4 GB) and low power requirements allow long deployments (many months) at high sample rates (16 Hz). We demonstrate the utility of TCM current measurements on a reef at Dongsha Atoll in the South China Sea, and in Vineyard Sound off Cape Cod, where the TCM performance was evaluated against ADP measurements. We have also used the TCM to record waves during an overwash event on a Cape Cod barrier beach during a winter storm. The TCM recorded waves as they came through the overwash channel, and the data were in agreement with the water-level record used as a reference. These tests demonstrate that TCMs may be used in a variety of near shore environments and have the potential to significantly increase the density of meters in future studies were current measurements are required.

  12. Social indicators study of Alaskan Coastal Villages I. Key informant summaries. Volume 2. Schedule B regions (Bristol Bay, Kodiak, Bering Straits). Final report

    SciTech Connect

    Brelsford, T.; Fienup-Riordan, A.; Jorgensen, J.; McNabb, S.; Petrivelli, P.

    1992-08-01

    The focus of this report is on Alaska Natives--Inupiaq and Yupik Eskimos, Athabascans, and Aleuts--for two important reasons: (1) Alaska Natives are numerically dominant populations in rural areas closest to potential offshore oil development sites and (2) their economic adjustments are most vulnerable to potential impacts from such development. This report is divided into Schedules A, B, and C. Comprising Schedules A and B are the study areas originally identified by Minerals Management Service for this study (North Slope, NANA, Bering Straits, Calista, Bristol Bay, Aleutian-Pribilof Islands, and Kodiak regions). Schedule C is comprised of communities that were added subsequent to the Exxon Valdez oil spill of 1989 in the Prince William Sound and Cook Inlet regions. One aim of this study was to document the attitudes and belief systems or ideologies about quality of life and well-being in the coastal, rural portions of Alaska.

  13. Herbivory and soil moisture drive long-term patterns of vegetation structure and function in Alaskan coastal tundra: results from resampling historic exclosures at Barrow

    NASA Astrophysics Data System (ADS)

    Johnson, D. R.; Lara, M. J.; Shaver, G. R.; Tweedie, C.

    2010-12-01

    Herbivores can be strong drivers of vegetation structure whose effects often vary depending on such things as primary productivity, the species makeup and structure of plants and herbivores, and other factors. In the Arctic however, the strength and direction of these effects have been difficult to detect and often vary widely among tundra types. In the coastal tundra near Barrow Alaska, fluctuations of lemming populations have long intrigued researchers and exclosure treatments were established at various periods between the 1950’s (Naval Arctic Research Laboratory) and early 1970’s (International Biological Program). Approximately 25% of these exclosures and control plots remain intact and were resampled in 2002 and 2010. The plots provide one of the few opportunities to assess how arctic tundra might be structured and function in the absence of herbivores. Plant cover and abundance as well as biomass estimates indicated that herbivores have had varied effects among soil moisture regimes. While herbivore exclusion resulted in a decrease in vascular plant abundance and diversity in all communities, dryer sites became lichen dominated and wetter sites became moss dominant. Additionally between resampling dates, these patterns have intensified as control plot graminoid biomass has increased in wetter sites while deciduous shrub biomass has increased slightly in dryer site control plots. Exclusion also resulted in differences in functional characteristics as well. Generally across all moisture regimes, exclusion increased albedo and decreased active layer, NDVI (normalized difference vegetation index), and CO2 uptake. Drier sites showed little difference in CH4 efflux, while moist and wet sites showed significant decreases in CH4 efflux in the absence of herbivores. These results suggest that herbivores have a strong effect on ecosystem structure and function in this coastal tundra and effects have become more pronounced recently. Because theoretical

  14. Influence of river discharge and ocean currents on coastal optical properties

    NASA Astrophysics Data System (ADS)

    Cherukuru, Nagur; Brando, Vittorio E.; Schroeder, Thomas; Clementson, Lesley A.; Dekker, Arnold G.

    2014-08-01

    The variability in the optical properties of a coastal region influenced by river runoff and multiple ocean currents in a southern hemisphere setting has been studied. The study area, Tasmanian coastal waters, is influenced by subtropical currents such as the East Australian Current (EAC) and the Zeehan Current (ZC) mix with cooler sub-Antarctic water (SAW). Freshwater discharges from rivers around the island and their mixing with the ocean currents also influence Tasmanian coastal waters. This study was performed to understand the influence of hydrodynamic processes on coastal optical properties and underwater light propagation. Physical, biogeochemical and optical properties were measured in Tasmanian coastal water during the austral autumn of 2007. In this study we found that physical properties have a good correlation with optical properties indicating the role played by hydrodynamic processes in distribution of optically active substances, optical properties of the water mass and underwater light propagation. Analysis of in situ salinity and temperature confirmed the presence of relatively cooler ZC in the South-West region, a cooler mixture of the ZC and SAW in the South-East, warm and saline EAC waters along the East coast and relatively cooler and fresh Bass straight waters along the North coast. In Tasmanian coastal waters light absorption in the water column is controlled by Coloured Dissolved Organic Matter (CDOM) with regionally varying contributions from Non-Algal Particulate (NAP) matter and phytoplankton. Absorption due to CDOM and NAP show a conservative mixing behaviour indicating that these biogeochemical components were delivered by the river and diluted in the coastal water. Suspended particulate matter in Tasmanian coastal water are highly scattering in nature and the beam attenuation is mainly due to light scattering. Variability in probability of light backscattering was mainly due to varying availability of non-algal particulate matter in

  15. Wind and Current Intermittency in Coastal and Atmospheric Environments

    NASA Astrophysics Data System (ADS)

    Sekula, Emil; Martinez-Benjamin, Juan Jose; Redondo, Jose M.; Jorge, Juan; Mahjoub, Otman B.

    2015-04-01

    We study at several non-homogeneous sites, such as the coastal Mediterranean Area (Ebro Delta, Blanes) and in the iberian Plateau the wind intermittency as well as the fractal structure of the induced cloud and wave fronts. Weather data from 10 and 100m hight masts are used to calculate Local Richardson number, Monin-Obukhov length, eddy transfer coefficients, turbulent kinetic energy, turbulent intensities, friction velocities and sensible heat flux at three levels (5, 17 and 32 m) were considered. The results show how the stability at 17 and 32 m influences the turbulent transfer near the ground. The shear of wind or convection are the main mechanism to produce mixing in the surface, which is often detected in satellite images of nearby clouds or coastal features. The influence of internal gravity-waves on the atmospheric boundary-layer during strong stable stratification is quantified. atmospheric and oceanic circulation involve non-linear intermittency that account for unresolved turbulent mixing and diffusion. The most sophisticated turbulent closure models involve using structure functions of higher order [1,2]. The relationship between the intermittency of turbulence and the type of stratification for different atmospheric situations during the SABLES98 field campaign. We first show that the scaling behaviour of the velocity structure function in events such as GABLS (GEWEX Atmospheric Boundary-Layer Study)and in combined ESA SAR measurements [3-6] near the coast exhibit fractal and intermittent scaling. Near the Gulf of Lyons, vortical scaling show coupling between synoptic and rossby deformation scales [7]. [1]Mahjoub O., Redondo J.M. and Babiano A. (1998) Structure Functions in Complex Flows, Applied Scientific Research 59, 299-313. [2]Fraunie P., Berreba S. Chashechkin Y., Velasco D. and Redondo J.M. (2008)LES and laboratory experiments on the decay of grid wakes in strongly stratified flows. Il Nuovo Cimento C 31, 909-930. [3]Diez M., Bezerra M

  16. Women and Minorities in Alaskan Aviation. Alaskan Equity Publication.

    ERIC Educational Resources Information Center

    Dordan, Mary Lou; Nicholson, Deborah

    This resource guide tells the story of Alaskan women and minority aviators and those in aviation-related businesses, from the early 20th century to the present. Developed for secondary students but also suitable for younger students, the guide combines six accounts of Alaskan women and minority aviators with classroom activities centered around…

  17. The freshwater transport and dynamics of the western Maine coastal current

    NASA Astrophysics Data System (ADS)

    Geyer, W. R.; Signell, R. P.; Fong, D. A.; Wang, J.; Anderson, D. M.; Keafer, B. A.

    2004-08-01

    Observations in the Gulf of Maine, USA, were used to characterize the freshwater transport, temporal variability and dynamics of the western Maine coastal current. These observations included moored measurements, multiple hydrographic surveys, and drifter releases during April-July of 1993 and 1994. There is a strong seasonal signal in salinity and along-shore velocity of the coastal current, caused by the freshwater inputs of the rivers entering the western Gulf. Surface salinity within the coastal current during the spring freshet is typically 2 psu below ambient, and along-shore currents in the surface layer are directed southwestward at speeds of 0.10-0.20 m s -1, occasionally reaching 0.50 m s -1. The plume thickness is typically 10-20 m in water depths of 50-100 m, thus it is well isolated from the bottom over most of its areal extent. The along-coast freshwater transport within the plume varies considerably due to variations in wind stress, but on time scales of weeks to months it follows the variations of riverine input, with a time lag consistent with the advective velocity. Less than half of the transport of the coastal current is explained by the baroclinic gradient; the barotropic forcing associated with the larger-scale dynamics of the Gulf of Maine accounts for about 60% of the transport. The volume of freshwater transport in the coastal current exceeds the local riverine input of fresh water by 30%, suggesting a significant contribution of freshwater transport from the St. John River, 500 km northeastward. The measurements within the western Maine coastal current, however, indicate a significant decrease in the baroclinic transport of fresh water along the coast, with an e-folding scale of approximately 200 km.

  18. Observations of the Eastern Maine Coastal Current and its offshore extensions in 1994

    NASA Astrophysics Data System (ADS)

    Pettigrew, Neal R.; Townsend, David W.; Xue, Huijie; Wallinga, John P.; Brickley, Peter J.; Hetland, Robert D.

    1998-12-01

    Cold surface temperatures, reflecting Scotian Shelf origins and local tidal mixing, serve as a tracer of the Eastern Maine Coastal Current and its offshore extensions, which appear episodically as cold plumes erupting from the eastern Maine shelf. A cold water plume emanating from the Eastern Maine Coastal Current in May 1994 was investigated using advanced very high resolution radiometer (AVHRR) imagery, shipboard surveys of physical and biochemical properties, and satellite-tracked drifters. Evidence is presented that suggests that some of the plume waters were entrained within the cyclonic circulation over Jordan Basin, while the major portion participated in an anticyclonic eddy at the distal end of the plume. Calculations of the nitrate transported offshore by the plume show that this feature can episodically export significant quantities of nutrients from the Eastern Maine Coastal Current to offshore regions that are generally nutrient depleted during spring-summer. A series of AVHRR images is used to document the seasonal along-shelf progression of the coastal plume separation point. We speculate on potential causes and consequences of plume separation from the coastal current and suggest that this feature may be an important factor influencing the patterns and overall biological productivity of the eastern Gulf of Maine.

  19. The Coastal Boundary Layer of the Yucatan Current

    NASA Astrophysics Data System (ADS)

    Coronado, C.; Candela, J.

    2009-04-01

    High-resolution measurements of the Yucatan Current, one of the most intense western-boundary currents in the World at these latitudes, were performed by CICESE as part of its CANEK project to understand the mechanisms that transfer properties across the shelf slope. Eight shallow water and moored acoustic Doppler current profilers (ADCPs) were deployed along a transect southeast of the shallow fringing reef lagoon of Puerto Morelos, through the narrow continental shelf and down the slope of the Yucatan Channel. The dataset spans 22 months, starting in May 2006, and includes full water column current profiles. Currents were found more variable over the shelf break than on the shelf or the slope. The mean current strongly follows the bathymetry everywhere and particularly on the slope. Currents were highly depth-independent in the upper 100 m, accounting for more than 80% of the eddy kinetic energy (EKE) in this layer. The analysis suggest that the transition between deep and shallow water current regimes is driven by the coupling of the lateral boundary layer imposed by the shelf-break, and the shallow surface and bottom boundary layers originated by wind stress, tidal currents, and wind wave bottom stress.

  20. Current anthropogenic pressures on agro-ecological protected coastal wetlands.

    PubMed

    Pascual-Aguilar, Juan; Andreu, Vicente; Gimeno-García, Eugenia; Picó, Yolanda

    2015-01-15

    Coastal wetlands are areas that suffer from great pressure. Much of it is due to the rapid development of the surrounding artificial landscapes, where socio-economic factors lead to alterations in the nearby environment, affecting the quality of natural and agricultural systems. This work analyses interconnections among landscapes under the hypothesis that urban-artificial impacts could be detected on soils and waters of an agro-ecological protected area, L'Albufera de Valencia Natural Park, located in the vicinity of the City of Valencia, Spain. The methodological framework developed addresses two types of anthropogenic pressure: (1) direct, due to artificialisation of soil covers that cause soil sealing, and (2) indirect, which are related to water flows coming from urban populations through sewage and irrigation systems and which, ultimately, will be identified by the presence of emerging pharmaceutical contaminants in waters of the protected area. For soil sealing, a methodology based on temporal comparison of two digital layers for the years 1991 and 2011, applying Geographical Information Systems and landscapes metrics, was applied. To determine presence of emerging contaminants, 21 water samples within the Natural Park were analysed applying liquid chromatography tandem mass spectrometry for the detection of 17 pharmaceutical compounds. Results showed that both processes are present in the Natural Park, with a clear geographical pattern. Soil sealing and presence of pharmaceuticals are more intensive in the northern part of the study area. This is related to population density (detection of pharmaceuticals) and land cover conversion from agricultural and natural surfaces to artificial ones (soil sealing). PMID:25042415

  1. Satellite, aircraft, and drogue studies of coastal currents and pollutants

    NASA Technical Reports Server (NTRS)

    Klemas, V.; Davis, G.; Lackie, J.; Whelan, W.; Tornatore, G.

    1977-01-01

    The mounting interest in extracting oil and other resources from the continental shelf and continuing use of shelf and estuarine waters for waste disposal is creating a need for synoptic means of determining currents and monitoring pollutants in this area. A satellite-aircraft-drogue approach is described which employs remotely tracked expendable drogues together with satellite and aircraft observations of waste plumes and current tracers such as dyes or suspended sediment. Tests conducted on the continental shelf and in Delaware Bay indicate that the approach provides a cost-effective means of studying current circulation, oil-slick movement, and ocean waste dispersion under a wide range of environmental conditions.

  2. Alaskan Commodities Irradiation Project

    SciTech Connect

    Zarling, J.P.; Swanson, R.B.; Logan, R.R.; Das, D.K.; Lewis, C.E.; Workman, W.G.; Tumeo, M.A.; Hok, C.I.; Birklid, C.A.; Bennett, F.L.

    1988-12-01

    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.

  3. Mesoscale process-induced variation of the West India Coastal Current during the winter monsoon.

    PubMed

    Jineesh, V K; Muraleedharan, K R; Lix John, K; Revichandran, C; Hareesh Kumar, P V; Naveen Kumar, K R

    2015-08-01

    This manuscript presents the analysis of current meter records at Kollam and Kannur along the 20-m isobaths during November-December 2005. Currents in the coastal waters are strongly influenced by winds (both local and remote forcing), tides, propagation of coastal Kelvin and Rossby waves, etc. We hypothesize that the mesoscale (spatial scales of 10-500 km and temporal scale of 10-100 days) features in ocean are also competent to alter the characteristics of coastal currents to a large extent. Analysis of sea level anomaly from the merged altimeter data reveals the existence of a large anticyclonic eddy in the southeastern Arabian Sea during the winter monsoon. The eddy moves westward with an average speed of ∼15 km day(-1) corresponding to an increase in sea level amplitude up to 28 cm. Off southwest India, the poleward flow is along the western flank of this anticyclonic eddy and the geostrophic current completes the circulation around the eddy. The eastward component of the geostrophic current at the northern edge of the eddy is bifurcated at ∼9° N: one flowing towards north and the other towards south. Current meter records at station Kollam revealed a dominant southward current due to the bifurcated southward component. The bifurcated northward component coalesced with the poleward flow along the western flank of the anticyclonic eddy. At Kannur, a poleward flow along the coast is responsible for a predominant northward trend in the observed current pattern during the initial phase of observation. A reversal in the current direction is caused by the southward-flowing geostrophic current along the eastern flank of the subsequent anticyclonic eddy centered at 73.5° E and 13° N. The stations were located at the eastern periphery of these anticyclonic eddies, where the mesoscale features overwhelm the seasonal characteristics of the West India Coastal Current (WICC). PMID:26183151

  4. The kinematic and hydrographic structure of the Gulf of Maine Coastal Current

    USGS Publications Warehouse

    Pettigrew, N.R.; Churchill, J.H.; Janzen, C.D.; Mangum, L.J.; Signell, R.P.; Thomas, A.C.; Townsend, D.W.; Wallinga, J.P.; Xue, H.

    2005-01-01

    The Gulf of Maine Coastal Current (GMCC), which extends from southern Nova Scotia to Cape Cod Massachusetts, was investigated from 1998 to 2001 by means of extensive hydrographic surveys, current meter moorings, tracked drifters, and satellite-derived thermal imagery. The study focused on two principal branches of the GMCC, the Eastern Maine Coastal Current (EMCC) that extends along the eastern coast of Maine to Penobscot Bay, and the Western Maine Coastal Current (WMCC) that extends westward from Penobscot Bay to Massachusetts Bay. Results confirm that GMCC is primarily a pressure gradient-driven system with both principal branches increasing their transport in the spring and summer due to fresh-water inflows, and flowing southwestward against the mean wind forcing during this period. In the spring and summer the subtidal surface currents in the EMCC range from 0.15 to 0.30 ms-1 while subtidal WMCC currents range from 0.05 to 0.15 ms-1. The reduction of southwestward transport near Penobscot Bay is accomplished via an offshore veering of a variable portion of the EMCC, some of which recirculates cyclonically within the eastern Gulf of Maine. The degree of summer offshore veering, versus leakage into the WMCC, varied strongly over the three study years, from nearly complete disruption in 1998 to nearly continuous through-flow in 2000. Observations show strong seasonal and interannual variability in both the strength of the GMCC and the degree of connectivity of its principal branches. ?? 2005 Elsevier Ltd. All rights reserved.

  5. The kinematic and hydrographic structure of the Gulf of Maine Coastal Current

    NASA Astrophysics Data System (ADS)

    Pettigrew, Neal R.; Churchill, James H.; Janzen, Carol D.; Mangum, Linda J.; Signell, Richard P.; Thomas, Andrew C.; Townsend, David W.; Wallinga, John P.; Xue, Huijie

    2005-09-01

    The Gulf of Maine Coastal Current (GMCC), which extends from southern Nova Scotia to Cape Cod Massachusetts, was investigated from 1998 to 2001 by means of extensive hydrographic surveys, current meter moorings, tracked drifters, and satellite-derived thermal imagery. The study focused on two principal branches of the GMCC, the Eastern Maine Coastal Current (EMCC) that extends along the eastern coast of Maine to Penobscot Bay, and the Western Maine Coastal Current (WMCC) that extends westward from Penobscot Bay to Massachusetts Bay. Results confirm that GMCC is primarily a pressure gradient-driven system with both principal branches increasing their transport in the spring and summer due to fresh-water inflows, and flowing southwestward against the mean wind forcing during this period. In the spring and summer the subtidal surface currents in the EMCC range from 0.15 to 0.30 ms -1 while subtidal WMCC currents range from 0.05 to 0.15 ms -1. The reduction of southwestward transport near Penobscot Bay is accomplished via an offshore veering of a variable portion of the EMCC, some of which recirculates cyclonically within the eastern Gulf of Maine. The degree of summer offshore veering, versus leakage into the WMCC, varied strongly over the three study years, from nearly complete disruption in 1998 to nearly continuous through-flow in 2000. Observations show strong seasonal and interannual variability in both the strength of the GMCC and the degree of connectivity of its principal branches.

  6. Freshwater transport in the coastal buoyancy-driven current affected by variable downwelling-favorable winds

    NASA Astrophysics Data System (ADS)

    Yankovsky, A. E.; Rogers-Cotrone, J.; Maze, G.; Weingartner, T. J.

    2009-04-01

    A typical feature of coastal circulation in mid- and high latitudes is the existence of buoyancy-driven currents originating from multiple or continuous sources of fresh (or brackish) water and propagating downstream, in the direction of a Kelvin wave. The examples include the Alaska Coastal Current (ACC), the East Greenland Coastal Current, the Norwegian Coastal Current, and the coastal current in the Gulf of Maine. These systems are affected by wind forcing, and previous studies found that downwelling-favorable winds trap buoyant water near the coast, steepen the isopycnals, and enhance the downstream velocity and freshwater transport in the coastal current. In this study we present a series of numerical experiments demonstrating that under certain conditions the downwelling favorable winds reduce the downstream freshwater transport compared to no-wind conditions due to some freshwater being transported offshore. These situations include: 1. Light average wind stresses (0.025 Pa or less), especially when the wind varies alongshore. The offshore freshwater transport is eddy-driven and is enhanced in the areas of converging wind stress. Eddy generation is associated with the wind-induced deepening of a buoyant layer near the coast. When the surface boundary layer is thin under light wind, this deepening translates into an enhanced vertical shear of the alongshore current through the thermal wind balance (geostrophic shear). 2. The cyclonic atmospheric system coming ashore builds up a sea level bulge at the coast upstream from the cyclone's center. This high pressure forms a filament transporting the freshwater offshore along the upstream flank of the cyclone. We apply the Regional Ocean Modeling System (ROMS) configured as a periodic channel and forced by multiple freshwater sources in the central part of the domain, and by the downwelling-favorable wind stress, both constant and variable. In particular, a moving cyclonic atmospheric system in the gradient wind

  7. Current response to wind in the Chukchi Sea: A regional coastal upwelling event

    NASA Astrophysics Data System (ADS)

    Johnson, Walter R.

    1989-02-01

    A cruise was conducted on the NOAA ship Oceanographer in August and September 1986 in the Chukchi Sea. Four short-term moorings were instrumented with sediment traps and Aanderaa RCM4 current meters. The currents at the three moorings near the Alaskan coast indicate a reversal of the normal northeastward flow to southwestward. This reversal was produced by wind, which had begun to blow from the east-northeast at up to 4.2 m s-1. The temperature time series indicated that upwelling colder water was moving upward near the coast. The nearshore mooring had the largest amplitude variation of currents and the largest temperature variation. The amplitude of the reversal decreased offshore. The station farthest from the coast was near the ice edge and on the other side of Barrow Canyon and a subsea bank. The flow there was consistently toward the east and is only poorly related to the wind. Water mass analysis was conducted using two techniques; the first was a traditional TS diagram method, and the second was a cluster analysis on TS pairs for the surface and near-bottom waters. Based on the shapes of the TS curves and their positions on the TS diagrams, a map of the water masses was constructed. A cluster analysis was performed on the surface TS pairs from each station and separately for the bottom TS pairs. For both of these techniques, the line separating the groupings follows the temperature contours (5° at the surface and 4° at the bottom) and the bottom salinity contours (32.5 PSU).

  8. Characterisation of coastal counter-currents on the inner shelf of the Gulf of Cadiz

    NASA Astrophysics Data System (ADS)

    Garel, E.; Laiz, I.; Drago, T.; Relvas, P.

    2016-03-01

    At the Gulf of Cadiz (GoC), poleward currents leaning along the coast alternate with coastal upwelling jets of opposite direction. Here the patterns of these coastal countercurrents (CCCs) are derived from ADCP data collected during 7 deployments at a single location on the inner shelf. The multiyear (2008-2014) time-series, constituting ~ 18 months of hourly records, are further analysed together with wind data from several sources representing local and basin-scale conditions. During one deployment, temperature sensors were also installed near the mooring site to examine the vertical thermal stratification associated with periods of poleward flow. These observations indicate that the coastal circulation is mainly alongshore and barotropic. However, a baroclinic flow is often observed shortly at the time of flow inversion to poleward. CCCs develop all year-round and exclusively control the occurrence of warm coastal water during the upwelling season. On average, one poleward flow lasting 3 days was observed every week, corresponding to CCCs during ~ 40% of the time without seasonal variability. Thus, the studied region is distinct from typical upwelling systems where equatorward coastal upwelling jets largely predominate. CCCs often start to develop near the bed and are frequently associated with 2-layer cross-shore flows characteristic of downwelling conditions (offshore near the bed). In general, the action of alongshore wind stress alone does not justify the development of CCCs. The coastal circulation is best correlated and shows the highest coherence with south-eastward wind in the basin that proceeds from the rotation of southward wind at the West coast of Portugal, hence suggesting a dominant control of large-scale wind conditions. In agreement, wavelet analyses indicate that CCCs are best correlated with alongshore wind occurring in a band period characteristic of the upwelling system (8-32 days). Furthermore, in the absence of wind coastal currents tend

  9. Experimental and numerical characterization of sea-state and coastal currents close to the Giglio island.

    NASA Astrophysics Data System (ADS)

    Brandini, Carlo; Taddei, Stefano; Doronzo, Bartolomeo; Costanza, Letizia; Fattorini, Maria; Serafino, Francesco; Ludeno, Giovanni; Ciarravano, Alessandro

    2015-04-01

    The study of sub-mesoscale circulation phenomena in coastal areas is complicated by the high resolution requested for both the observation and the simulation of such currents, and by the difficulty of appropriately validating the remote sensing and the numerical data. In this work we present the results of a long period of waves and coastal currents observations, produced by the X-band radar that was implemented in 2012 at the Giglio Island, after the accident of the Costa Concordia ship. The radar installation has allowed to verify the structure of particular sea states and hydrodynamic phenomena that can be reproduced also by means of some numerical models implemented in the area: in particular, SWAN for waves prediction, and ROMS for coastal circulation . The models were configured through multiple nesting in order to reach resolutions comparable to coastal radar observations. The measurements have been validated independently through the use of drifters in experimental campaigns around the island. The complete view of the 2D spectrum, as recorded by the radar, allowed to fully characterize sea states with crossed-seas and also coastal refraction phenomena (due to the southwest sea that turns all around the island), diffracted and even reflected wave patterns (Ludeno et al., 2014). The circulation phenomena are even more complex, as they are produced by a combination of local forcing conditions and tides, and by the interaction of the large-scale circulation with the local conformation of the bathymetry and the coastline. Circulation cells have been often observed, even in the form of a double-gyre configuration, also due to the non-stationarity of the atmospheric forcing and to multiple interaction effects. In our work we attempt to reproduce some of these phenomena, which are difficult to model also for their inherent non-linearity. We have considered the use of the native ROMS algorithm for multiple nested domains, by implementing it up to 50 m resolution

  10. Influence of varying upper ocean stratification on coastal near-inertial currents

    NASA Astrophysics Data System (ADS)

    Kim, Sung Yong; Kurapov, Alexander L.; Kosro, P. Michael

    2015-12-01

    The influence of varying horizontal and vertical stratification in the upper layer (O>(10>) m) associated with riverine waters and seasonal atmospheric fluxes on coastal near-inertial currents is investigated with remotely sensed and in situ observations of surface and subsurface currents and realistic numerical model outputs off the coast of Oregon. Based on numerical simulations with and without the Columbia River (CR) during summer, the directly wind-forced near-inertial surface currents are enhanced by 30%-60% when the near-surface layer has a stratified condition due to riverine water inputs from the CR. Comparing model results without the CR for summer and winter conditions indicates that the directly wind-forced near-inertial surface current response to a unit wind forcing during summer are 20%-70% stronger than those during winter depending on the cross-shore location, which is in contrast to the seasonal patterns of both mixed-layer depth and amplitudes of near-inertial currents. The model simulations are used to examine aspects of coastal inhibition of near-inertial currents, manifested in their spatial coherence in the cross-shore direction, where the phase propagates upward over the continental shelf, bounces at the coast, and continues increasing upward offshore (toward surface) and then downward offshore at the surface, with magnitudes and length scales in the near-surface layer increasing offshore. This pattern exhibits a particularly well-organized structure during winter. Similarly, the raypaths of clockwise near-inertial internal waves are consistent with the phase propagation of coherence, showing the influence of upper layer stratification and coastal inhibition.

  11. Multiple dipole eddies in the Alaska Coastal Current detected with Landsat thematic mapper data

    NASA Technical Reports Server (NTRS)

    Ahlnas, Kristina; Royer, Thomas C.; George, Thomas H.

    1987-01-01

    Seventeen dipole eddies, including five large, well-formed ones, three second-generation eddies, and two double eddies, were observed in the Alaska Coastal Current near Kayak Island in one single scene of the Landsat thematic mapper (TM) on April 22, l985. The digital Landsat TM satellite data were computer analyzed to extract details in the near coastal circulation in the northern Gulf of Alaska. Enhancement techniques were applied to the visible and thermal IR bands. The features are evident only in the visible bands because of the ability of these bands to detect the distribution of sediments in the near surface. These eddies did not have a significant thermal signature.The sources of these sediments are the glacial streams found throughout the Gulf of Alaska coast. Eddies of this configuration and frequency have never been observed here previously. However, the oceanographic and meteorological conditions are typical for this time of year. These eddies should be important to the cross-shelf mixing processes in the Alaska Coastal Current and are an indicator that the flow here can be unstable at certain times of the year.

  12. Transport and coastal zooplankton communities in the northern California Current system

    NASA Astrophysics Data System (ADS)

    Bi, Hongsheng; Peterson, William T.; Strub, Paul T.

    2011-06-01

    Alongshore transport was estimated from the gridded AVISO altimeter data and water level data from NOAA tide gauges (1993-2010) for the northern California Current (NCC) system. The biomass of the cold neritic copepods including Calanus marshallae, Pseudocalanus mimus and Acartia longiremis (dominants in the eastern Bering Sea, coastal Gulf of Alaska, and NCC) was estimated from a 15 year time series of zooplankton samples (1996-2010) collected biweekly at a coastal station 9 km off Newport Oregon U.S.A. The alongshore currents and the biomass of the cold neritic copepods exhibit a strong seasonal pattern and fluctuate in opposite phase: positive alongshore current (from south) leads to low biomass in winter and negative alongshore current (from north) leads to high biomass in summer. When the Pacific Decadal Oscillation (PDO) is positive, i.e., warm conditions around the northeast Pacific, there is more movement of water from the south in the NCC during winter. When the PDO is negative, there is more movement of water from the north during summer. The mean biomass of cold neritic copepods was positively correlated with the survival rate of juvenile coho salmon and cumulative transport was negatively correlated with coho salmon survival, i.e., in years when a greater portion of the source waters feeding the NCC enters from the north, the greater the salmon survival. We conclude that alongshore transport manifests PDO signals and serves as a linkage between large scale forcing to local ecosystem dynamics.

  13. Lagrangian analysis of satellite-derived currents: Application to the North Western Mediterranean coastal dynamics

    NASA Astrophysics Data System (ADS)

    Bouffard, Jerome; Nencioli, Francesco; Escudier, Romain; Doglioli, Andrea Michelangelo; Petrenko, Anne A.; Pascual, Ananda; Poulain, Pierre-Marie; Elhmaidi, Dalila

    2014-03-01

    Optimal interpolation methods for improving the reconstruction of coastal dynamics from along-track satellite altimetry measurements have been recently developed over the North Western Mediterranean Sea. Maps of satellite-derived geostrophic current anomalies are generated using these methods, and added to different mean circulation fields in order to obtained absolute geostrophic currents. The resulting fields are then compared to standard AVISO products, and their accuracies are assessed with Lagrangian diagnostics. The trajectories of virtual particle clusters are simulated with a Lagrangian code either with new current fields or with the AVISO ones. The simulated trajectories are then compared to 16 in situ drifter trajectories to evaluate the performance of the different velocity fields. The comparisons show that the new current fields lead to better results than the AVISO one, especially over the shallow continental shelf of the Gulf of Lion. However, despite the use of innovative strategies, some altimetry limitations still persist in the coastal domain, where small scale processes remain sub-sampled by conventional altimetry coverage but will benefit from technological development in the near future. Some of the limitations of the Lagrangian diagnostics presently used are also analyzed, but dedicated studies will be required for future further investigations.

  14. Synergistic surface current mapping by spaceborne stereo imaging and coastal HF radar

    NASA Astrophysics Data System (ADS)

    Matthews, John Philip; Yoshikawa, Yutaka

    2012-09-01

    Well validated optical and radar methods of surface current measurement at high spatial resolution (nominally <100 m) from space can greatly advance our ability to monitor earth's oceans, coastal zones, lakes and rivers. With interest growing in optical along-track stereo techniques for surface current and wave motion determinations, questions of how to interpret such data and how to relate them to measurements made by better validated techniques arise. Here we make the first systematic appraisal of surface currents derived from along-track stereo Sun glitter (ATSSG) imagery through comparisons with simultaneous synoptic flows observed by coastal HF radars working at frequencies of 13.9 and 24.5 MHz, which return averaged currents within surface layers of roughly 1 m and 2 m depth respectively. At our Tsushima Strait (Japan) test site, we found that these two techniques provided largely compatible surface current patterns, with the main difference apparent in current strength. Within the northwest (southern) comparison region, the magnitudes of the ATSSG current vectors derived for 13 August 2006 were on average 22% (40%) higher than the corresponding vectors for the 1-m (2-m) depth radar. These results reflect near-surface vertical current structure, differences in the flow components sensed by the two techniques and disparities in instrumental performance. The vertical profile constructed here from ATSSG, HF radar and ADCP data is the first to resolve downwind drift in the upper 2 m of the open ocean. The profile e-folding depth suggests Stokes drift from waves of 10-m wavelength visible in the images.

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

    SciTech Connect

    Not Available

    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.

  16. Engaging Alaskan Students in Cryospheric Research

    NASA Astrophysics Data System (ADS)

    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

  17. Current status of coastal zone issues and management in China: a review.

    PubMed

    Cao, Wenzhi; Wong, Ming H

    2007-10-01

    This paper identifies and examines social-economic and environmental issues recently emerged in China's coastal zone. Evaluation of management scheme and progress in perspectives of coordinated legislation, institutional arrangement, public participation, capacity building, and scientific research (mainly coastal planning and functional zoning) in China's coastal zone are made. The Chinese government has made a significant effort in developing legislation for the coastal zone. Jurisdictional and zoning boundaries, and allocating use rights for coastal and marine resources have been established. State Oceanic Administration is the leading agency responsible for China's ocean policymaking and overall management of ocean and coastal affairs. A demonstrated project for integrated coastal management in Xiamen has been implemented, and is characterized as "decentralization" approach in decision-making process. In view of the above, comprehensive coastal management in China is a big challenge, facing with many difficulties. Finally, recommendations are raised for tackling these issues for China's coastal zone management. PMID:17532045

  18. The Mexican Coastal Current: A subsurface seasonal bridge that connects the tropical and subtropical Northeastern Pacific

    NASA Astrophysics Data System (ADS)

    Gómez-Valdivia, F.; Parés-Sierra, A.; Flores-Morales, A. L.

    2015-11-01

    We used a three-dimensional numerical model to analyze the seasonal variability of the coastal circulation off SW Mexico. In agreement with previous research, our model reproduced a Mexican Coastal Current (MCC) that dominates the regional poleward circulation. The modeled dynamics evidenced an energetic semiannual component that governed the subsurface seasonal variability of this poleward flow. Below the thermocline the MCC was stronger during spring and fall, when it reached subsurface seasonal-averaged velocities of ∼10 cms-1 and flowed continuously from the Gulf of Tehuantepec to the entrance of the Gulf of California. There, the subsurface MCC bifurcated in one branch that continued along the coast of mainland Mexico and a second branch that crossed the gulf and joined the California Undercurrent. Instead of the local wind, the semiannual MCC variability was induced by the transit of equatorial Kelvin waves whose upwelling (downwelling) phase propagation strengthen (weakened) the subsurface poleward circulation along the Tropical Pacific off Mexico. The MCC dynamics reported in this study accounts for the, previously reported, semiannual variability of the alongshore transport and salinity content in the southern Gulf of California. Moreover, the subsurface bridge between the MCC and the California Current System represents an external source of momentum that helps to explain the intensification of the California Undercurrent during spring and fall.

  19. A global map of suitability for coastal Vibrio cholerae under current and future climate conditions.

    PubMed

    Escobar, Luis E; Ryan, Sadie J; Stewart-Ibarra, Anna M; Finkelstein, Julia L; King, Christine A; Qiao, Huijie; Polhemus, Mark E

    2015-09-01

    Vibrio cholerae is a globally distributed water-borne pathogen that causes severe diarrheal disease and mortality, with current outbreaks as part of the seventh pandemic. Further understanding of the role of environmental factors in potential pathogen distribution and corresponding V. cholerae disease transmission over time and space is urgently needed to target surveillance of cholera and other climate and water-sensitive diseases. We used an ecological niche model (ENM) to identify environmental variables associated with V. cholerae presence in marine environments, to project a global model of V. cholerae distribution in ocean waters under current and future climate scenarios. We generated an ENM using published reports of V. cholerae in seawater and freely available remotely sensed imagery. Models indicated that factors associated with V. cholerae presence included chlorophyll-a, pH, and sea surface temperature (SST), with chlorophyll-a demonstrating the greatest explanatory power from variables selected for model calibration. We identified specific geographic areas for potential V. cholerae distribution. Coastal Bangladesh, where cholera is endemic, was found to be environmentally similar to coastal areas in Latin America. In a conservative climate change scenario, we observed a predicted increase in areas with environmental conditions suitable for V. cholerae. Findings highlight the potential for vulnerability maps to inform cholera surveillance, early warning systems, and disease prevention and control. PMID:26048558

  20. CLASSIFYING COASTAL WATERS: HISTORICAL PERSPECTIVE AND CURRENT FOCUS ON AQUATIC STRESSORS

    EPA Science Inventory

    Coastal ecosystems are ecologically and commercially productive habitats that are experiencing significant impacts associated with accelerated population growth in coastal zones. The Clean Water Act requires identification of impaired water bodies and determination of the causes ...

  1. Phlorotannins from Alaskan Seaweed Inhibit Carbolytic Enzyme Activity

    PubMed Central

    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

  2. Local scale, coastal currents influence recruitment to freshwater populations in the European eel Anguilla anguilla: a case study from the Isle of Man.

    PubMed

    Barry, J; Mcharg, K; Dodd, J A; Adams, C E

    2015-06-01

    This study examines juvenile Anguilla anguilla (<30 cm) abundance in five study catchments on the Isle of Man. Preliminary results suggest that juvenile abundance is negatively correlated with increasing coastal current speed at river mouth entry (P < 0·05). These findings indicate that at least under some circumstances, tidally driven coastal currents may influence recruitment to freshwater habitats; therefore, it is presumed that high coastal current speed at the entry to river mouths may reduce the likelihood of freshwater entry. PMID:26033294

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

    USGS Publications Warehouse

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

    2002-01-01

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

  4. Alaskan thermokarst terrain and possible Martian analog

    NASA Technical Reports Server (NTRS)

    Gatto, L. W.; Anderson, D. M.

    1975-01-01

    A first-order analog to Martian fretted terrain has been recognized on enhanced, ERTS-1 (Earth Resources Technology Satellite) imagery of Alaskan Arctic thermokarst terrain. The Alaskan analog displays flat-floored valleys and intervalley uplands characteristic of fretted terrain. The thermokarst terrain has formed in a manner similar to one of the processes postulated for the development of the Martian fretted terrain.

  5. Lagrangian observations of surface coastal flows North of 30∘S in the Humboldt Current system

    NASA Astrophysics Data System (ADS)

    Marín, Víctor H.; Delgado, Luisa E.

    2007-03-01

    We analyze the surface circulation of the coastal waters of the Humboldt Current system based on five Lagrangian satellite-tracked drifters (three launched on January 2005 and two on January 2006) deployed at 30∘S, lasting 30 and 60 days, respectively. Based on the concurrent analysis of buoy's records, sea surface temperature (SST) satellite images and local wind forcing, we propose that the coastal surface circulation between 30∘S and 23∘S can be described as a 0.2ms-1 equatorward flow. Coastal export seems to depend upon the generation of cold-water, locally forced, squirts advecting upwelling waters up to 295 km offshore. Within the nearshore zone ( <30km from the coast), near-inertial motion and alongshore changes in current direction may serve as mechanisms for enhancing water residence time.

  6. Comparative metagenome analysis of an Alaskan glacier.

    PubMed

    Choudhari, Sulbha; Lohia, Ruchi; Grigoriev, Andrey

    2014-04-01

    The temperature in the Arctic region has been increasing in the recent past accompanied by melting of its glaciers. We took a snapshot of the current microbial inhabitation of an Alaskan glacier (which can be considered as one of the simplest possible ecosystems) by using metagenomic sequencing of 16S rRNA recovered from ice/snow samples. Somewhat contrary to our expectations and earlier estimates, a rich and diverse microbial population of more than 2,500 species was revealed including several species of Archaea that has been identified for the first time in the glaciers of the Northern hemisphere. The most prominent bacterial groups found were Proteobacteria, Bacteroidetes, and Firmicutes. Firmicutes were not reported in large numbers in a previously studied Alpine glacier but were dominant in an Antarctic subglacial lake. Representatives of Cyanobacteria, Actinobacteria and Planctomycetes were among the most numerous, likely reflecting the dependence of the ecosystem on the energy obtained through photosynthesis and close links with the microbial community of the soil. Principal component analysis (PCA) of nucleotide word frequency revealed distinct sequence clusters for different taxonomic groups in the Alaskan glacier community and separate clusters for the glacial communities from other regions of the world. Comparative analysis of the community composition and bacterial diversity present in the Byron glacier in Alaska with other environments showed larger overlap with an Arctic soil than with a high Arctic lake, indicating patterns of community exchange and suggesting that these bacteria may play an important role in soil development during glacial retreat. PMID:24712530

  7. Coastal upwelling on the far eastern Agulhas Bank associated with large meanders in the Agulhas Current

    NASA Astrophysics Data System (ADS)

    Goschen, W. S.; Bornman, T. G.; Deyzel, S. H. P.; Schumann, E. H.

    2015-06-01

    Six large solitary meanders in the Agulhas Current, so-called Natal Pulses, propagated down the eastern coast of South Africa between 2009 and 2011. Their influence on the coastal waters between Port Alfred and Algoa Bay, on the far eastern Agulhas Bank, was measured by thermistor strings moored at 30-80 m bottom depths and two current metres (30 m bottom depth) located at both sides of Algoa Bay. During all events active upwelling lasting 1-3 weeks was observed over the inner shelf and in Algoa Bay. During upwelling the isotherms ascended at an average rate of 1.8 m day-1 as the cold bottom layer increased in thickness to 40-60 m, although upwelled water did not break the surface in all cases. Cold water remained in the area for a further 2-3 weeks. During three Natal Pulses the water temperatures at the outer moorings initially increased as the plume of the leading edge (crest) of the meander moved onshore. During one Natal Pulse upwelling was recorded before the warm water plume impacted the moorings. At the onset of upwelling currents switched to the southwest in the case of Bird Island and southward at the Cape Recife inner-bay site and reached a maximum speed of 80 cm s-1. During all Natal Pulses cold bottom water (10-12 °C) flooded over the 80 m bottom depth moorings as the crest of the meander moved onshore, but also around the same time the core of the Agulhas Current began to move offshore. In all cases upwelling was wide-spread.

  8. Coastal flooding and storm protection program; field verification program. Mathematical modeling of three-dimensional coastal currents and sediment dispersion: model development and application. Final report

    SciTech Connect

    Sheng, Y.P.

    1983-09-01

    A comprehensive model of Coastal currents and sediment dispersion has been formulated and applied to the Mississippi Sound and adjacent continental shelf waters. The study combines mathematical modeling of various hydrodynamic and sedimentary processes with laboratory and field experiments. Of primary importance is the development of an efficient and comprehensive three-dimensional, finite-difference model of coastal, estuarine, and lake currents (CELC3D). The model resolves currents driven by tide, wind, and density gradient. It has been applied to the Mississippi Sound, and results agree well with measured surface displacements and currents during two episodes. Rates of entrainment and deposition of the Mississippi Sound sediments have been studied in a laboratory flume. Effects of (1) bottom shear stress, (2) bed properties, (3) salinity of water, and (4) sediment type on the erodability of sediments have been examined. Results of the laboratory study have been incorporated into the bottom boundary conditions for a three-dimensional sediment dispersion model. Gravitational settling and particle size distribution of the Mississippi Sound sediments were also studied in laboratories. Bottom boundary layer dynamics and wave effect on sediment dispersion have been studied by means of a turbulent transport model and a wave model. Model simulations of sediment dispersion in the Mississippi Sound agree well available data from ship surveys.

  9. Characteristics of the Norwegian Coastal Current during Years with High Recruitment of Norwegian Spring Spawning Herring (Clupea harengus L.).

    PubMed

    Skagseth, Øystein; Slotte, Aril; Stenevik, Erling Kåre; Nash, Richard D M

    2015-01-01

    Norwegian Spring Spawning herring (NSSH) Clupea harengus L. spawn on coastal banks along the west coast of Norway. The larvae are generally transported northward in the Norwegian Coastal Current (NCC) with many individuals utilizing nursery grounds in the Barents Sea. The recruitment to this stock is highly variable with a few years having exceptionally good recruitment. The principal causes of recruitment variability of this herring population have been elusive. Here we undertake an event analysis using data between 1948 and 2010 to gain insight into the physical conditions in the NCC that coincide with years of high recruitment. In contrast to a typical year when northerly upwelling winds are prominent during spring, the years with high recruitment coincide with predominantly southwesterly winds and weak upwelling in spring and summer, which lead to an enhanced northward coastal current during the larval drift period. Also in most peak recruitment years, low-salinity anomalies are observed to propagate northward during the spring and summer. It is suggested that consistent southwesterly (downwelling) winds and propagating low-salinity anomalies, both leading to an enhanced northward transport of larvae, are important factors for elevated recruitment. At the same time, these conditions stabilize the coastal waters, possibly leading to enhanced production and improved feeding potential along the drift route to Barents Sea. Further studies on the drivers of early life history mortality can now be undertaken with a better understanding of the physical conditions that prevail during years when elevated recruitment occurs in this herring stock. PMID:26636759

  10. Characteristics of the Norwegian Coastal Current during Years with High Recruitment of Norwegian Spring Spawning Herring (Clupea harengus L.)

    PubMed Central

    Skagseth, Øystein; Slotte, Aril; Stenevik, Erling Kåre; Nash, Richard D. M.

    2015-01-01

    Norwegian Spring Spawning herring (NSSH) Clupea harengus L. spawn on coastal banks along the west coast of Norway. The larvae are generally transported northward in the Norwegian Coastal Current (NCC) with many individuals utilizing nursery grounds in the Barents Sea. The recruitment to this stock is highly variable with a few years having exceptionally good recruitment. The principal causes of recruitment variability of this herring population have been elusive. Here we undertake an event analysis using data between 1948 and 2010 to gain insight into the physical conditions in the NCC that coincide with years of high recruitment. In contrast to a typical year when northerly upwelling winds are prominent during spring, the years with high recruitment coincide with predominantly southwesterly winds and weak upwelling in spring and summer, which lead to an enhanced northward coastal current during the larval drift period. Also in most peak recruitment years, low-salinity anomalies are observed to propagate northward during the spring and summer. It is suggested that consistent southwesterly (downwelling) winds and propagating low-salinity anomalies, both leading to an enhanced northward transport of larvae, are important factors for elevated recruitment. At the same time, these conditions stabilize the coastal waters, possibly leading to enhanced production and improved feeding potential along the drift route to Barents Sea. Further studies on the drivers of early life history mortality can now be undertaken with a better understanding of the physical conditions that prevail during years when elevated recruitment occurs in this herring stock. PMID:26636759

  11. Social indicators study of Alaskan Coastal Villages I. Key informant summaries. Volume 1. Schedule a regions (North Slope, Nana, Calista, Aleutian-Pribilof). Social and economic studies. Final report

    SciTech Connect

    Brelsford, T.; Fienup-Riordan, A.; Jorgensen, J.; McNabb, S.; Petrivelli, P.

    1992-08-01

    The focus of this report is on Alaska Natives--Inupiaq and Yupik Eskimos, Athabascans, and Aleuts--for two important reasons: (1) Alaska Natives are numerically dominant populations in rural areas closest to potential offshore oil development sites and (2) their economic adjustments are most vulnerable to potential impacts from such development. This report is divided into Schedules A, B, and C. Comprising Schedules A and B are the study areas originally identified by Minerals Management Service for this study (North Slope, NANA, Bering Straits, Calista, Bristol Bay, Aleutian-Pribilof Islands, and Kodiak regions). Schedule C is comprised of communities that were added subsequent to the Exxon Valdez oil spill of 1989 in the Prince William Sound and Cook Inlet regions. One aim of this study was to document the attitudes and belief systems or ideologies about quality of life and well-being in the coastal, rural portions of Alaska.

  12. Environmental assessment of resource development in the Alaska coastal zone based on LANDSAT imagery

    NASA Technical Reports Server (NTRS)

    Belon, A. E.; Miller, J. M.; Stringer, W. J.

    1975-01-01

    LANDSAT imagery was interpreted to derive color coded maps of the physical parameters of the Alaskan coastal zone. Synoptic overviews depict sea surface circulation, sediment transport, and ice cover dimensions.

  13. Laboratory and numerical simulations of gravity-driven coastal currents: Departures from geostrophic theory

    NASA Astrophysics Data System (ADS)

    Gregorio, S. O.; Haidvogel, D. B.; Thomas, P. J.; Taskinoglu, E. S.; Skeen, A. J.

    2011-09-01

    Laboratory realizations and numerical simulations of buoyant, gravity-driven coastal plumes are summarized and compared to the inviscid geostrophic theory of Thomas and Linden (2007). The lengths, widths and velocities of the buoyant currents, as well as their internal structure and dynamics, are studied. Agreement between the laboratory and numerical experiments and the geostrophic theory is found to depend on two non-dimensional parameters which characterize, respectively, the steepness of the plumes isopycnal interface ( I) and the strength of horizontal viscous forces ( EkH, the horizontal Ekman number). In general, the numerical and laboratory experiments are in good agreement when conducted at comparable values of I and EkH. The best agreement between experiments (both laboratory and numerical) and the geostrophic theory are found for the least viscous flows, though important departures from the theoretical predictions are nonetheless found, particularly in the early development of the plume system. At elevated values of the horizontal Ekman number, laboratory and numerical experiments depart more significantly from theory, e.g., in the rate of plume movement along the coast. A simple extension to the geostrophic theory suggests that the discrepancy between the theoretical and experimental propagation speed should be proportional to the square root of the horizontal Ekman number. The numerical simulations confirm this relationship. For some combinations of the non-dimensional parameters, instabilities develop in the seaward edge of the buoyant plumes. The laboratory and numerical experiments are used together to infer the region within parameter space within which the instabilities occur. Mixing of ambient and buoyant fluids by the plume-edge instabilities is explored using the numerical results.

  14. Infragravity currents in a small ría: Estuary-amplified coastal edge waves?

    NASA Astrophysics Data System (ADS)

    Uncles, R. J.; Stephens, J. A.; Harris, C.

    2014-10-01

    Observations are presented of estuarine infragravity oscillations in a very small estuary, the Ría de Santiuste, northern Spain, that discharges into a bay. Time-scale calculations and measurements indicate that the most likely source of amplified infragravity waves within the estuary are coastal edge waves, which appear to be resonating between the headlands of the bay, and onshore-offshore seiching of waters that may be resonating between the beach and the bay's seaward limit. Infragravity waves in the estuary have a narrow, power-dominant periodicity range of 4.3-4.8 min. Generally, only very weak waves, and at other periodicities, occur within the tidal river when it is unaffected by the tide. Although infragravity water-level amplitudes are small in the tidal river, typically ˜0.01 m during high water, the corresponding velocity amplitudes are significant, typically ˜0.1 m s-1, despite the occurrence of high runoff conditions during these measurements. Within the estuary and close to the mouth, near-bed salinity shows considerable variability that is a consequence of salt wedge oscillations with periodicities that are within the range of 4.3-4.8 min. Model results for simulated neap to spring high-water water levels show that wave periodicities in the range 3.5-4.5 min correspond approximately to 3λ/4 resonances. The model also indicates that an effect of low runoff is to greatly enhance resonant behaviour within the estuary, such that water level amplitudes of 0.02 m at the mouth can produce wave currents as fast as 0.4 m s-1 within the estuary, compared with ˜0.1 m s-1 during high runoff.

  15. Intraseasonal variability of nearshore productivity in the Northern Humboldt Current System: The role of coastal trapped waves

    NASA Astrophysics Data System (ADS)

    Echevin, Vincent; Albert, Aurélie; Lévy, Marina; Graco, Michelle; Aumont, Olivier; Piétri, Alice; Garric, Gilles

    2014-02-01

    The impact of intraseasonal coastal-trapped waves on the nearshore Peru ecosystem is investigated using observations and a regional eddy-resolving physical-ecosystem coupled model. Model results show that intraseasonal variability over the period 2000-2006 represents about one fourth of the total surface chlorophyll variance and one third of the carbon export variance on the Peruvian shelf. Evidence is presented that subsurface nutrient and chlorophyll intraseasonal variability are mainly forced by the coastally trapped waves triggered by intraseasonal equatorial Kelvin waves reaching the South American coast, and propagate poleward along the Peru shore at a speed close to that of high order coastal trapped waves modes. The currents associated with the coastal waves induce an input of nutrients that triggers a subsequent phytoplankton bloom and carbon export. The impact of the local wind-forced intraseasonal variability on the ecosystem is of a similar order of magnitude to that remotely forced in the northern part of the Peru shelf on [50-90] day time scales and dominates over the entire shelf on [20-30] day time scales.

  16. Alaskan oil and gas prospects: Boom or bust

    SciTech Connect

    Woods, T.J. )

    1994-02-14

    With the exception of the Arctic Coastal Plain, the Alaskan resource potential is negligible. However, the recent Sunfish discovery in Cook Inlet suggests that significant volumes of oil remain to be found in South Alaska. And North Alaska production has remained strong over the last decade despite continued predictions of a rapid decline within 5--10 years. Alaska is largely unexplored or frontier, which introduces large uncertainty into estimates of its oil and gas prospects. Two major uncertainties that affect estimates of recoverable oil and gas in a frontier region are the distribution of hydrocarbons between oil and gas and the total volume of hydrocarbons. These uncertainties can be reduced, or at least better understood, using a macro perspective based on the Lower 48 US. While such a macro perspective cannot by itself estimate the resource base in a region, it can provide a basis from which to judge the relative conservatism or optimism of a particular estimate.

  17. Summertime coastal current reversal opposing offshore forcing and local wind near the middle east coast of Korea: Observation and dynamics

    NASA Astrophysics Data System (ADS)

    Park, Jae-Hyoung; Chang, Kyung-Il; Nam, SungHyun

    2016-07-01

    A 6 year long current measurement at a buoy station off the middle east coast of Korea reveals an equatorward reversal of coastal current in summer opposing poleward local wind stress and offshore boundary current. The current reversal extends about 40 km offshore from the coast and is concurrent with warming and freshening of water column. Estimates of the depth-averaged alongshore momentum balance suggest a major balance between the alongshore pressure gradient and the lateral friction. Sources of the pressure gradient for the summertime current reversal are identified as the alongshore buoyancy gradient driven by the wind curl gradient and the prevalence of warmer and lower salinity water in the north. Alongshore pressure gradient and velocity induced by the wind curl gradient are quantified, which yields the observed seasonal current reversal.

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

    PubMed

    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

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

    PubMed Central

    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. Circulation in the French mediterranean coastal zone near Marseilles: the influence of wind and the Northern Current

    NASA Astrophysics Data System (ADS)

    Albérola, C.; Millot, C.

    2003-04-01

    Current meters were moored for a year both in and beyond the Cassis Bay to study the dispersion of muds discharged at a depth of ˜300 m, through a pipe, a few km from the coast and at the head of a submarine canyon. The east-west orientation of the coastline and a marked orography constrain the major winds to easterlies or westerlies. Empirical orthogonal function analysis shows that both wind regimes create a significant down-wind circulation, with the latter inducing also intense upwelling. Characteristics of the Northern Current, which flows along the slope, have been defined using a fine-grid hydrological survey. A narrow continental shelf allows the Northern Current to reach often the coastal zone in the study area; thus, the overall water circulation in the embayment is westward. In winter, this current develops steep mesoscale meanders and penetrates easily through the canyon, into the bay. Hence, although the coastal circulation near Marseilles is partly down-wind, it is dependent mainly on the Northern Current (on both general and meso-scales). The mesoscale variability cannot be predicted without monitoring the Northern Current itself.

  1. Circulation in the French Mediterranean coastal zone near Marseilles: the influence of wind and the Northern Current

    NASA Astrophysics Data System (ADS)

    Albérola, C.; Millot, C.

    2003-04-01

    Current meters were moored for a year both in and beyond the Cassis Bay to study the dispersion of muds discharged at a depth of about 300 m, through a pipe, a few km from the coast and at the head of a submarine canyon. The east-west orientation of the coastline and a marked orography constrain the major winds to easterlies or westerlies. Empirical orthogonal function (EOF) analysis shows that both wind regimes create a significant down-wind circulation, with the latter inducing also intense upwelling. Characteristics of the Northern Current, which flows along the slope, have been defined using a fine-grid hydrological survey. A narrow continental shelf allows the Northern Current to reach often the coastal zone in the study area; thus, the overall water circulation in the embayment is westward. In winter, this current develops steep mesoscale meanders and penetrates easily through the canyon, into the bay. Hence, although the coastal circulation near Marseilles is partly down-wind, it is dependent mainly on the Northern Current (on both general and meso- scales). The mesoscale variability cannot be predicted without monitoring the Northern Current itself.

  2. Diffusion in coastal and harbour zones, effects of Waves,Wind and Currents

    NASA Astrophysics Data System (ADS)

    Diez, M.; Redondo, J. M.

    2009-04-01

    As there are multiple processes at different scales that produce turbulent mixing in the ocean, thus giving a large variation of horizontal eddy diffusivities, we use a direct method to evaluate the influence of different ambient parameters such as wave height and wind on coastal dispersion. Measurements of the diffusivity are made by digital processing of images taken from from video recordings of the sea surface near the coast. The use of image analysis allows to estimate both spatial and temporal characteristics of wave fields, surface circulation and mixing in the surf zone, near Wave breakers and inside Harbours. The study of near-shore dispersion [1], with the added complexity of the interaction between wave fields, longshore currents, turbulence and beach morphology, needs detailed measurements of simple mixing processes to compare the respective influences of forcings at different scales. The measurements include simultaneous time series of waves, currents, wind velocities from the studied area. Cuantitative information from the video images is accomplished using the DigImage video processing system [3], and a frame grabber. The video may be controlled by the computer, allowing, remote control of the processing. Spectral analysis on the images has also used n order to estimate dominant wave periods as well as the dispersion relations of dominant instabilities. The measurements presented here consist mostly on the comarison of difussion coeficients measured by evaluating the spread of blobs of dye (milk) as well as by measuring the separation between different buoys released at the same time. We have used a techniques, developed by Bahia(1997), Diez(1998) and Bezerra(2000)[1-3] to study turbulent diffusion by means of digital processing of images taken from remote sensing and video recordings of the sea surface. The use of image analysis allows to measure variations of several decades in horizontal diffusivity values, the comparison of the diffusivities

  3. Cardiovascular Deaths among Alaskan Natives, 1980-86.

    ERIC Educational Resources Information Center

    Middaugh, John P.

    1990-01-01

    Analyzes death certificate data to discover the number of deaths of Alaskan natives caused by cardiovascular disease. Rates from cardiovascular diseases and atherosclerosis from 1980-86 among Alaskan natives were lower than rates among other Alaskans, while death rates from other causes were higher. Discusses the possible impact of diet. (JS)

  4. Across-Shelf Transport of Bivalve Larvae: Can the Interface between a Coastal Current and Inshore Waters Act as an Ecological Barrier to Larval Dispersal?

    PubMed Central

    Tilburg, Charles E.; McCartney, Michael A.; Yund, Philip O.

    2012-01-01

    Using an integrated physical and biological approach, we examined across-shelf advection and exchange and the associated transport of bivalve larvae in the presence of a strong coastal current separated from the coast by a stratified inshore environment. We tested the hypothesis that the interface of the coastal current and inshore waters can act as an ecological barrier to across-shelf transport of larvae but can be overcome by wind- or tidally-induced transport. Our study region in the Gulf of Maine encompasses a coastal current that diverges from the coast as it moves downshelf. The region inshore of this current is home to several species that exhibit limited recruitment in spite of extensive upshelf larval sources. Analysis of surface water temperatures and wind velocities revealed episodic decreases in temperature along the coast correlated with alongshelf (but not upwelling) winds, indicating wind-forced onshore movement of the cold coastal current. Such wind-driven onshore migrations are more common along the northern portion of the study region where the coastal current is near the coast, tidal currents are strong, and wind directions are more conducive to onshore migration, but rarer further south where the interface between inshore waters and the coastal current is further offshore and suitable wind events are less common. The distribution of bivalve larvae was consistent with the physical measurements. There was little across-shelf variation in larval abundance where the current abuts the coast, indicating strong across-shelf exchange of larvae, but strong across-shelf variation in larval density where the stratified inshore waters separate the current from the coast, indicating weak across-shelf transport of larvae. Our results suggest that the interface between the coastal current and inshore waters may constitute a major ecological barrier to larval dispersal in the southern part of the region that may only be overcome by rare, strong wind

  5. The Costa Rica Coastal Current, eddies and wind forcing in the Gulf of Tehuantepec, Southern Mexican Pacific

    NASA Astrophysics Data System (ADS)

    Reyes-Hernández, Cristóbal; Ahumada-Sempoal, Miguel Ángel; Durazo, Reginaldo

    2016-02-01

    The hydrographic structure and circulation of the Southern Mexican Pacific, from August 31 to September 24 2004, when tropical atmospheric activity was at its peak, was analyzed based on AVISO absolute dynamic topography and an array of 106 CTD profiles, within an area of about 500 km×500 km between Punta Maldonado and Puerto Chiapas. The surveyed area was occupied by mesoscale anticyclonic and cyclonic eddies that determined the path of water with temperature and salinity characteristic of the Costa Rica Coastal Current. The origin of each eddy was investigated with respect to QuikSCAT wind conditions. The sequence of AVISO images and wind data showed that the largest anticyclonic eddies originated outside the Gulf of Tehuantepec through mechanisms distinct from local wind forcing, although two northerly wind events in the Gulf of Tehuantepec possibly had an influence on the smallest anticyclonic and cyclonic eddies. The relative position of each eddy allowed the flow of relatively low temperature and salinity water (the Costa Rica Coastal Current) into and throughout the Gulf of Tehuantepec, converging at about Puerto Angel with relatively high temperature and salinity water moving from the west.

  6. Helping Kids Succeed--Alaskan Style.

    ERIC Educational Resources Information Center

    Association of Alaska School Boards, Juneau.

    The purpose of this book is to serve as a tool for individuals helping to make Alaskan communities places where youth can grow up to be strong, capable, and caring. The book is built around the Search Institute's Youth Developmental Assets Framework, which is comprised of the key building blocks in youth development. The book notes 40 assets that…

  7. A comparison between laboratory and numerical simulations of gravity-driven coastal currents with a geostrophic theory

    NASA Astrophysics Data System (ADS)

    Gregorio, Sandy; Thomas, Peter; Haidvogel, Dale; Taskinoglu, Ezgi; Skeen, Andrew

    2011-11-01

    Laboratory and numerical simulations of buoyant, gravity-driven coastal currents are summarized and compared to the inviscid geostrophic theory of Thomas & Linden 2007. The lengths, widths and velocities of the buoyant currents are studied. Agreement between the laboratory and numerical experiments and the geostrophic theory is found to depend on two non-dimensional parameters which characterize, respectively, the steepness of the plumes isopycnal interface and the strength of horizontal viscous forces (quantified by the horizontal Ekman number). The best agreement between experiments (both laboratory and numerical) and the geostrophic theory are found for the least viscous flows. At elevated values of the horizontal Ekman number, laboratory and numerical experiments depart more significantly from theory. MEOM/LEGI from the 1st of October 2011.

  8. Net primary productivity, upwelling and coastal currents in the Gulf of Ulloa, Baja California, México

    NASA Astrophysics Data System (ADS)

    González-Rodríguez, E.; Trasviña-Castro, A.; Gaxiola-Castro, G.; Zamudio, L.; Cervantes-Duarte, R.

    2012-08-01

    The Gulf of Ulloa, a highly productive area off the western coast of the Baja California Peninsula, is examined for five successive years (2003-2007) by using satellite data and seasonal net primary productivity (NPP) estimates obtained from a vertical generalised production model. The results identify that northwestern winds blow parallel to the coast throughout the year. However, highest NPP occurs from March to June. During this period, an equatorward coastal current transports water from neighbouring upwelling areas to the northern Gulf of Ulloa and in combination with local upwelling, which injects nutrients into the euphotic zone, produce the observed increase in NPP. The opposite situation occurs in late summer when a warm poleward current of tropical characteristics arrives and inhibits the productivity in the whole region and generates the yearly lowest NPP levels. Our findings reveal the importance of lateral advection in the modulation of the primary productivity in this subtropical upwelling region.

  9. Alaskan North Slope petroleum systems

    USGS Publications Warehouse

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

    2003-01-01

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

  10. A pleistocene sand sea on the Alaskan arctic coastal plain

    USGS Publications Warehouse

    Carter, L.D.

    1981-01-01

    A ridge and thermokarst-basin landscape that is strikingly portrayed in Landsat winter imagery consists of large Pleistocene dunes that have been modified by younger eolian activity and thermokarst processes. This is the most extensive area of large stabilized dunes yet reported in the North American Arctic; the landscape is of particular interest because it has been proposed as a first-order analogfor martian fretted terrain. Recognition ofthe large dunes permits a new interpretation for linear and curvilinear trends visible in Landsat summer imagery.

  11. Combined use of glider, radar and altimetry data to study a coastal current in the western Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Troupin, Charles; Pascual, Ananda; Lana, Arancha; Valladeau, Guillaume; Pujol, Isabelle; Tintoré, Joaquin

    2014-05-01

    The Mediterranean Sea is characterized by a small Rossby radius of deformation, hence small structures and eddies. The Ibiza Channel, located in the Balearic Sea, is of particular importance since it controls the exchanges in the western Mediterranean Sea. In order to understand and describe the upper ocean dynamics, a multi-sensor/integrated approach was applied in the Ibiza Channel in the first days of August 2013 during the G-AltiKa mission. This approach combines: Sea-level anomaly (SLA) measurements from Saral-AltiKa track no. 16, which passed west of Ibiza island. 1-Hz and 40-Hz data were considered. Glider data obtained along the satellite track a few hours after its passage. The horizontal resolution ranges from 5 km offshore to about 1 km in the coastal area. HF radar hourly velocities on a 3 km-resolution grid that partially covers the study region (range up to 74 km offshore). Dynamic height (DH) was derived from the glider temperature and salinity profiles, while Absolute Dynamic Topography (ADT) was obtained by combining SLA and the new Mean Dynamic Topography (MDT) jointly produced by CLS and SOCIB. From DH and SLA, the cross-track velocities were derived using geostrophy relations. Different filters were applied on SLA data and different reference levels were tested for the DH computation. DH and ADT both displayed very weak variations, on the order of 2-3 cm, along the glider trajectory. The glider- and the altimetry-derived velocities exhibit the signal of a meander centered at 38.65°N and a narrow coastal current flowing northward a few kilometers off Ibiza. These computed velocities are on the order of 20 cm/s, as confirmed by the HF radar. The time separation between the passage of the satellite and the glider can explain the discrepancies observed between the two platforms. Our results highlight the promising measurements offered by SARAL/AltiKa in the coastal band. In particular, the satellite was able is able to capture the northern edge of

  12. Impacts of climate change on coastal benthic ecosystems: assessing the current risk of mortality outbreaks associated with thermal stress in NW Mediterranean coastal areas

    NASA Astrophysics Data System (ADS)

    Pairaud, Ivane Lilian; Bensoussan, Nathaniel; Garreau, Pierre; Faure, Vincent; Garrabou, Joaquim

    2014-01-01

    In the framework of climate change, the increase in ocean heat wave frequency is expected to impact marine life. Large-scale positive temperature anomalies already occurred in the northwestern Mediterranean Sea in 1999, 2003 and 2006. These anomalies were associated with mass mortality events of macrobenthic species in coastal areas (0-40 m in depth). The anomalies were particularly severe in 1999 and 2003 when thousands of kilometres of coasts and about 30 species were affected. The aim of this study was to develop a methodology to assess the current risk of mass mortality associated with temperature increase along NW Mediterranean continental coasts. A 3D regional ocean model was used to obtain the temperature conditions for the period 2001-2010, for which the model outputs were validated by comparing them with in situ observations in affected areas. The model was globally satisfactory, although extremes were underestimated and required correction. Combined with information on the thermo-tolerance of a key species (the red gorgonian P. clavata) as well as its spatial distribution, the modelled temperature conditions were then used to assess the risk of mass mortality associated with thermal stress for the first time. Most of the known areas of observed mass mortality were found using the model, although the degree of risk in certain areas was underestimated. Using climatic IPCC scenarios, the methodology could be applied to explore the impacts of expected climate change in the NW Mediterranean. This is a key issue for the development of sound management and conservation plans to protect Mediterranean marine biodiversity in the face of climate change.

  13. Projected future duration of the sea-ice-free season in the Alaskan Arctic

    NASA Astrophysics Data System (ADS)

    Wang, Muyin; Overland, James E.

    2015-08-01

    Global warming and continued reduction in sea ice cover will result in longer open water duration in the Arctic, which is important for the shipping industry, marine mammals, and other components of the regional ecosystem. In this study we assess the length of open water duration in the Alaskan Arctic over the next few decades using the set of latest coupled climate models (CMIP5). The Alaskan Arctic, including the Chukchi and the Beaufort Sea, has been a major region of summer sea ice retreat since 2007. Thirty five climate models from CMIP5 are evaluated and twelve are selected for composite projections based on their historical simulation performance. In the regions north of the Bering Strait (north of 70° N), future open-water duration shifts from a current 3-4 months to a projected near 5 months by 2040 based on the mean of the twelve selected climate models. There is considerable north-south gradient in projected durations. Open water duration is about 1 month shorter along the same latitudes in the Beaufort Sea compared with that in the Chukchi Sea. Uncertainty is generally ±1 month estimated from the range of model results. Open-water duration in the Alaskan Arctic expands quickly in these models over the next decades which will impact regional economic access and potentially alter ecosystems. Yet the northern Alaskan Arctic from January through May will remain sea ice covered into the second half of the century due to normal lack of sunlight.

  14. Poleward displacement of coastal upwelling-favorable winds in the ocean's eastern boundary currents through the 21st century

    NASA Astrophysics Data System (ADS)

    Rykaczewski, Ryan R.; Dunne, John P.; Sydeman, William J.; García-Reyes, Marisol; Black, Bryan A.; Bograd, Steven J.

    2015-08-01

    Upwelling is critical to the biological production, acidification, and deoxygenation of the ocean's major eastern boundary current ecosystems. A leading conceptual hypothesis projects that the winds that induce coastal upwelling will intensify in response to increased land-sea temperature differences associated with anthropogenic global warming. We examine this hypothesis using an ensemble of coupled, ocean-atmosphere models and find limited evidence for intensification of upwelling-favorable winds or atmospheric pressure gradients in response to increasing land-sea temperature differences. However, our analyses reveal consistent latitudinal and seasonal dependencies of projected changes in wind intensity associated with poleward migration of major atmospheric high-pressure cells. Summertime winds near poleward boundaries of climatological upwelling zones are projected to intensify, while winds near equatorward boundaries are projected to weaken. Developing a better understanding of future changes in upwelling winds is essential to identifying portions of the oceans susceptible to increased hypoxia, ocean acidification, and eutrophication under climate change.

  15. Spatiotemporal current variation of coastal-trapped waves west of the Noto Peninsula measured by using fishing boats

    NASA Astrophysics Data System (ADS)

    Fukudome, Ken-ichi; Igeta, Yosuke; Senjyu, Tomoharu; Okei, Noriyuki; Watanabe, Tatsuro

    2016-03-01

    Spatiotemporal current variations of coastal-trapped waves (CTWs) were investigated by using a current dataset obtained from daily fishing operations west of the Noto Peninsula (NTP), Japan. Cross-shore lines located in southern, middle, and northern parts of the west coast of the NTP were designed to detect characteristics of CTWs with a time interval of a few days and about 5-km resolution in the cross-shore direction. Accuracy validation by using moored current meter data and sea level data demonstrated that the established dataset expresses accurate variations with periods of several days. The generation and propagation of a CTW event associated with a low-pressure zone passing north of the study area in late May 2010 were analyzed. Along-shore currents with the coast on the right strengthened in every line simultaneously with the domination of the southerly wind, and then weakened in order from south to north simultaneously with weakening of the southerly wind. Although the along-shore currents of the CTWs linearly decreased heading offshore along the south and middle lines, these currents broadened within about 50 km from the coast along the north line, with small variations in the cross-shelf direction, with an increase in shelf width. These generation, propagation and current structure characteristics are clarified and interpreted by the characteristics of the estimated possible CTWs west of the NTP and numerical experiments, which reproduce wind-induced freely propagating CTWs. A change in the propagation characteristics and the structure of the CTWs associated with bottom topography indicates the possibility that adjustments can occur on the order of a few dozen kilometers.

  16. Flow velocities of Alaskan glaciers.

    PubMed

    Burgess, Evan W; Forster, Richard R; Larsen, Christopher F

    2013-01-01

    Our poor understanding of tidewater glacier dynamics remains the primary source of uncertainty in sea level rise projections. On the ice sheets, mass lost from tidewater calving exceeds the amount lost from surface melting. In Alaska, the magnitude of calving mass loss remains unconstrained, yet immense calving losses have been observed. With 20% of the global new-water sea level rise coming from Alaska, partitioning of mass loss sources in Alaska is needed to improve sea level rise projections. Here we present the first regionally comprehensive map of glacier flow velocities in Central Alaska. These data reveal that the majority of the regional downstream flux is constrained to only a few coastal glaciers. We find regional calving losses are 17.1 Gt a(-1), which is equivalent to 36% of the total annual mass change throughout Central Alaska. PMID:23857302

  17. Offshore oil in the Alaskan Arctic

    NASA Technical Reports Server (NTRS)

    Weeks, W. F.; Weller, G.

    1984-01-01

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

  18. Effect of coastal-trapped waves and wind on currents and transport in the Gulf of California

    NASA Astrophysics Data System (ADS)

    Gutiérrez, Manuel O.; López, Manuel; Candela, Julio; Castro, Rubén.; Mascarenhas, Affonso; Collins, Curtis A.

    2014-08-01

    Subsurface pressure (SsP) observations from stations inside and outside of the Gulf of California (GC) are used to analyze the relationship between low-frequency currents, temperature, and transport inside the GC and intraseasonal coastal-trapped waves (CTWs), which propagate poleward along the coast toward the GC. Correlation functions and coherences of SsP stations were consistent with intraseasonal CTWs splitting in two at the mouth of the gulf: one part enters the gulf, propagates around the gulf, and eventually, toward the mouth, and another part that appears to "jump" the mouth of the gulf and travels poleward along the west coast of the peninsula. The correlation and coherence estimates of SsP at Manzanillo with currents showed that downwelling CTWs generated along-gulf current anomalies toward the head of the gulf at the mainland shelf of the mouth, whereas at Ballenas Channel sill (San Lorenzo sill) these waves generated current anomalies toward the mouth near the surface (bottom). At the San Lorenzo (SL) sill, downwelling CTWs increased the near-bottom (˜400 m) temperature and reduced the bottom transport of deep, fresher, and colder water that flows toward the head of the gulf. Cross-Calibrated Multiplatform winds were used to investigate their relationship with currents. The first empirical orthogonal function of the along-gulf wind stress showed that wind blowing toward the head of the gulf generated a reduction of bottom transport toward the head of the gulf through the SL sill, and intensified surface geostrophic current fluctuations toward the head of the gulf. There was also significant correlation between inflow bottom transport and outflow surface geostrophic velocities averaged across the gulf, consistent with the exchange pattern for the Northern Gulf.

  19. NASA's Current and Next Generation Coastal Remote Sensing Missions and Coral Reef Projects.

    NASA Technical Reports Server (NTRS)

    Guild, Liane S.

    2015-01-01

    The LLILAS Faculty Research Initiative presents a two-day symposium, Caribbean Coral Reefs at Risk. This international symposium examines the current state and future of coral reef conservation efforts throughout the Caribbean from the perspective of government agencies, nongovernment organizations, and academia.

  20. Projecting the Current & Future Impact of Storm Surges on Coastal Flood Extent at Pigeon Point, South-West Tobago, through Hydrodynamic Modelling Analyses

    NASA Astrophysics Data System (ADS)

    Seenath, Avidesh; Wilson, Matthew; Miller, Keith

    2014-05-01

    Under climate change, sea levels will continue to rise and the intensity of tropical storms and hurricanes will amplify. Consequently, the incidence rate of high magnitude storm surges may increase which will enhance the probability of coastal flood events in low lying coastal communities. The purpose of this study is to determine the current and potential future areas that may be at risk of flooding from storm surges, of different magnitudes, for the low lying Pigeon Point area of south-west Tobago. The objective of this research is to develop an understanding of the extent of flooding that these events can ensue on low lying coastal areas that are widespread through the Caribbean under current and future sea level conditions. A two-dimensional hydrodynamic flood model was created for Pigeon Point using the model code LISFLOOD-FP by incorporating topographic data of the terrain and sea bed referenced to mean sea level together with tides. This was used to assess the impact of different storm surge levels on the study area. Storm surge scenarios were computed using information acquired from the Saffir-Simpson hurricane scale which provides an estimate of storm surge height based on the category of hurricane, existing projections of global sea level rise and recorded values of high tide for Pigeon Point. Results indicate that the quantity of area likely to flood, in each surge scenario, increases significantly under future projected global sea level conditions compared to current conditions. The potential implications of this on the local population, island's economy and beach geomorphology are examined. Results obtained were incorporated into a Geographic Information System (GIS) to produce current and future flood maps indicating potential inundation extent based on storm surge height to guide coastal flood management programmes in south-west Tobago. We conclude that greater focus should be placed on implementing flood mitigation measures to protect our coasts and

  1. Investigating and forecasting coastal Adriatic surface currents by using neural networks (NEURAL)

    NASA Astrophysics Data System (ADS)

    Vilibic, Ivica; Zagar, Nedjeljka; Cosoli, Simone; Dadic, Vlado; Horvath, Kristian; Ivankovic, Damir; Jesenko, Blaz; Mihanovic, Hrvoje; Sepic, Jadranka; Tudor, Martina

    2014-05-01

    We present major components of the project NEURAL (www.izor.hr/neural) funded by the Unity Through Knowledge Fund (www.ukf.hr). The project aims to investigate and to build an efficient and reliable prototype of the ocean surface current forecasting system, based on high-frequency (HF) radar measurements, numerical weather prediction (NWP) model outputs and neural network algorithms (Self-Organising Maps). The Self-Organising Maps (SOM) method, a kind of neural network algorithms that performs a nonlinear smooth mapping of high-dimensional input data into the elements of a low-dimensional array, has previously been used on historical HF radar measurements and NWP Aladin/HR wind fields, which were operational in the northern Adriatic during 2008. It was found that the SOM surface currents patterns and associated SOM surface currents and winds patterns were highly correlated, indicating the predominance of the wind-driven forcing on the measured ocean currents. Therefore, a forecasting system has been proposed, that will use operational NWP products for the Adriatic region, then search for the closest SOM solutions in wind fields and finally to forecast ocean currents by using associated SOM patterns in HF radar currents. Such a prototype forecasting system will be tested on a long and quality-checked HF radar surface currents dataset available in the northern Adriatic, where the first part of the series will be used for the training of the SOM and the second part for assessing the skill performance of the surface currents hindcast. Two NWP systems will be used on the project: (1) high-resolution non-hydrostatic research WRF-ARW model based at the Faculty of Mathematics and Physics of the University of Ljubljana, and (2) operational Aladin/HR NWP system of the Meteorological and Hydrological Service of Croatia. The prototype forecasting system will be also tested in the middle Adriatic after the collection of substantially long high-quality surface currents dataset

  2. Evidence for permafrost thaw and transport from an Alaskan North Slope watershed

    NASA Astrophysics Data System (ADS)

    Schreiner, Kathryn M.; Bianchi, Thomas S.; Rosenheim, Brad E.

    2014-05-01

    Burial of organic carbon (OC) in marine sediments is one of the most important linkages between the short-term biologic carbon cycle and the long-term geologic carbon cycle. Yet much is still unknown about the fate of terrigenous OC in marine coastal margins. Here the delivery of particulate OC (POC) to the Colville River deltaic region in the Alaskan Beaufort Sea by particulates of varying densities is studied through the use of ramped temperature pyrolysis and radiocarbon analyses. The Colville River is the largest river in North America whose watershed is underlain completely by high Arctic permafrost tundra. A variety of sources of POC are considered, including terrestrial soils, Pleistocene-aged yedoma-like sediments, coastal peat erosion, and marine POC. We provide the first evidence that riverine POC from the Colville River contains old (Pleistocene-sourced) OC, suggesting ongoing thaw and mobilization of yedoma-like permafrost OC from this northern Alaskan watershed. Additionally, much of this OC appears to be fairly labile and therefore could be readily oxidized and returned to the atmosphere.

  3. Numerical modeling investigation of radiation stress in coastal wave-current coupling

    NASA Astrophysics Data System (ADS)

    Guan, Changlong; Li, Rui

    2014-05-01

    It is believed that the radiation stress is the main driving force for nearshore wave-induced currents. So far several theoretical formulas of radiation stress have been proposed, among which the vertical structures differ considerably. A numerical wave flume (NWF) have been established on the basis of the CFD software, and applied to simulate the wave motion in various shallow water topography with different incident waves. The results from the NWF is used to analyze the features of radiation stress. It is found, that the vertical integral of the radiation stress is agreeably consistent with the well-known classical result by Longuet-Higgins and Stewart (1964), while the vertical structure of the radiation stress is discontinuous at the surface where the maximum exists, which can be better characterized with the formula by Mellor (2008). The effects of radiation stress and wave roller are implemented in a coupled SWAN-POM model, so that the coupled model is able to simulate the wave setup and wave-induced current. The numerical modeling results have been verified by the field measurements. It is shown that the modelled wave setup corresponding to various radiation stress formulas is well in agreement with the field observation. This means the modeled wave setup is dependent on the vertical integral of radiation stress rather than the vertical structure of that. In comparison with the observed current velocity and direction data, it is shown that the modeled results with Mellor's radiation stress formula plus wave roller is able to be consistent with the filed measurement well. This indicates that the modeled wave-induced current is dependent on the vertical structure of radiation stress rather than the vertical integral of that.

  4. Hydrophobicity and leakage current statistics of polymeric insulators long-term exposed to coastal contamination

    SciTech Connect

    Soerqvist, T.; Vlastos, A.E.

    1996-12-31

    The hydrophobicity of polymeric insulators is crucial for their performance. This paper reports the hydrophobicity and the peak leakage current statistics of one porcelain, two ethylene-propylene-diene monomer (EPDM) and four silicone rubber (SIR) commercially available insulators. The insulators have been energized with 130 kV rms phase-to-ground AC voltage under identical outdoor conditions for more than seven years. The results presented show that under wet and polluted conditions the hydrophilic EPDM rubber insulators develop high leakage currents and substantial arcing. During a typical salt-storm the arcing amplitude of the EPDM rubber insulators is at least twice as high as that of the porcelain insulator. The SIR insulators, on the other hand, preserve a high degree of hydrophobicity after more than seven years in service and maintain very low leakage currents. However, the results show that during heavy salt contaminated conditions a highly stressed SIR insulator can temporarily lose its hydrophobicity and thereby develop considerable surface arcing.

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

    SciTech Connect

    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.

  6. Educational Provisions for the Alaskan Natives Since 1867.

    ERIC Educational Resources Information Center

    Hopkins, Thomas Robert

    The study compiles and records the history of the administration of education for Alaskan natives since the United States purchased the territory from Russia in 1876. Chapter 1, An Overview of the Development of the Alaskan Native, covers the development of missionary and government schools, the growth and development of Native education from 1906…

  7. A short-term predictive system for surface currents from a rapidly deployed coastal HF radar network

    NASA Astrophysics Data System (ADS)

    Barrick, Donald; Fernandez, Vicente; Ferrer, Maria I.; Whelan, Chad; Breivik, Øyvind

    2012-05-01

    In order to address the need for surface trajectory forecasts following deployment of coastal HF radar systems during emergency-response situations (e.g., search and rescue, oil spill), a short-term predictive system (STPS) based on only a few hours data background is presented. First, open-modal analysis (OMA) coefficients are fitted to 1-D surface currents from all available radar stations at each time interval. OMA has the effect of applying a spatial low-pass filter to the data, fills gaps, and can extend coverage to areas where radial vectors are available from a single radar only. Then, a set of temporal modes is fitted to the time series of OMA coefficients, typically over a short 12-h trailing period. These modes include tidal and inertial harmonics, as well as constant and linear trends. This temporal model is the STPS basis for producing up to a 12-h current vector forecast from which a trajectory forecast can be derived. We show results of this method applied to data gathered during the September 2010 rapid-response demonstration in northern Norway. Forecasted coefficients, currents, and trajectories are compared with the same measured quantities, and statistics of skill are assessed employing 16 24-h data sets. Forecasted and measured kinetic variances of the OMA coefficients typically agreed to within 10-15%. In one case where errors were larger, strong wind changes are suspected and examined as the cause. Sudden wind variability is not included properly within the STPS attack we presently employ and will be a subject for future improvement.

  8. Physiological performance of an Alaskan shrub (Alnus fruticosa) in response to disease (Valsa melanodiscus) and water stress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    At northern latitudes, plants are being exposed to multiple climate-related stresses as warming temperatures push plants beyond the physiological limits of their current range. Our study focused on two stresses related to the warming and drying of the Alaskan boreal forest: drought and disease. We e...

  9. Aerobic Methane Oxidation in Alaskan Lakes Along a Latitudinal Transect

    NASA Astrophysics Data System (ADS)

    Martinez-Cruz, K. C.; Sepulveda-Jauregui, A.; Walter Anthony, K. M.; Anthony, P.; Thalasso, F.

    2013-12-01

    Karla Martinez-Cruz* **, Armando Sepulveda-Jauregui*, Katey M. Walter Anthony*, Peter Anthony*, and Frederic Thalasso**. * Water and Environmental Research Center, Institute of Northern Engineering, University of Alaska Fairbanks, Fairbanks, Alaska. ** Biotechnology and Bioengineering Department, Cinvestav, Mexico city, D. F., Mexico. Methane (CH4) is the third most important greenhouse gas in the atmosphere, after carbon dioxide and water vapor. Boreal lakes play an important role in the current global warming by contributing as much as 6% of global atmospheric CH4 sources annually. On the other hand, aerobic methane oxidation (methanotrophy) in lake water is a fundamental process in global methane cycling that reduces the amount of CH4 emissions to the atmosphere. Several environmental factors affect aerobic methane oxidation in the water column both directly and indirectly, including concentration of CH4 and O2, temperature and carbon budgets of lakes. We analyzed the potential of aerobic methane oxidation (PMO) rates in incubations of water collected from 30 Alaskan lakes along a north-south transect during winter and summer 2011. Our findings showed an effect of CH4 and O2 concentrations, temperature and yedoma thawing permafrost on PMO activity in the lake water. The highest PMO rates were observed in summer by lakes situated on thawing yedoma permafrost, most of them located in the interior of Alaska. We also estimated that 60-80% of all CH4 produced in Alaskan lakes could be taken up by methanotrophs in the lake water column, showing the significant influence of aerobic methane oxidation of boreal lakes to the global CH4 budget.

  10. Carbon cycle uncertainty in the Alaskan Arctic

    NASA Astrophysics Data System (ADS)

    Fisher, J. B.; Sikka, M.; Oechel, W. C.; Huntzinger, D. N.; Melton, J. R.; Koven, C. D.; Ahlström, A.; Arain, M. A.; Baker, I.; Chen, J. M.; Ciais, P.; Davidson, C.; Dietze, M.; El-Masri, B.; Hayes, D.; Huntingford, C.; Jain, A. K.; Levy, P. E.; Lomas, M. R.; Poulter, B.; Price, D.; Sahoo, A. K.; Schaefer, K.; Tian, H.; Tomelleri, E.; Verbeeck, H.; Viovy, N.; Wania, R.; Zeng, N.; Miller, C. E.

    2014-08-01

    Climate change is leading to a disproportionately large warming in the high northern latitudes, but the magnitude and sign of the future carbon balance of the Arctic are highly uncertain. Using 40 terrestrial biosphere models for the Alaskan Arctic from four recent model intercomparison projects - NACP (North American Carbon Program) site and regional syntheses, TRENDY (Trends in net land atmosphere carbon exchanges), and WETCHIMP (Wetland and Wetland CH4 Inter-comparison of Models Project) - we provide a baseline of terrestrial carbon cycle uncertainty, defined as the multi-model standard deviation (σ) for each quantity that follows. Mean annual absolute uncertainty was largest for soil carbon (14.0 ± 9.2 kg C m-2), then gross primary production (GPP) (0.22 ± 0.50 kg C m-2 yr-1), ecosystem respiration (Re) (0.23 ± 0.38 kg C m-2 yr-1), net primary production (NPP) (0.14 ± 0.33 kg C m-2 yr-1), autotrophic respiration (Ra) (0.09 ± 0.20 kg C m-2 yr-1), heterotrophic respiration (Rh) (0.14 ± 0.20 kg C m-2 yr-1), net ecosystem exchange (NEE) (-0.01 ± 0.19 kg C m-2 yr-1), and CH4 flux (2.52 ± 4.02 g CH4 m-2 yr-1). There were no consistent spatial patterns in the larger Alaskan Arctic and boreal regional carbon stocks and fluxes, with some models showing NEE for Alaska as a strong carbon sink, others as a strong carbon source, while still others as carbon neutral. Finally, AmeriFlux data are used at two sites in the Alaskan Arctic to evaluate the regional patterns; observed seasonal NEE was captured within multi-model uncertainty. This assessment of carbon cycle uncertainties may be used as a baseline for the improvement of experimental and modeling activities, as well as a reference for future trajectories in carbon cycling with climate change in the Alaskan Arctic and larger boreal region.

  11. Twenty-first-century warming of a large Antarctic ice-shelf cavity by a redirected coastal current.

    PubMed

    Hellmer, Hartmut H; Kauker, Frank; Timmermann, Ralph; Determann, Jürgen; Rae, Jamie

    2012-05-10

    The Antarctic ice sheet loses mass at its fringes bordering the Southern Ocean. At this boundary, warm circumpolar water can override the continental slope front, reaching the grounding line through submarine glacial troughs and causing high rates of melting at the deep ice-shelf bases. The interplay between ocean currents and continental bathymetry is therefore likely to influence future rates of ice-mass loss. Here we show that a redirection of the coastal current into the Filchner Trough and underneath the Filchner-Ronne Ice Shelf during the second half of the twenty-first century would lead to increased movement of warm waters into the deep southern ice-shelf cavity. Water temperatures in the cavity would increase by more than 2 degrees Celsius and boost average basal melting from 0.2 metres, or 82 billion tonnes, per year to almost 4 metres, or 1,600 billion tonnes, per year. Our results, which are based on the output of a coupled ice-ocean model forced by a range of atmospheric outputs from the HadCM3 climate model, suggest that the changes would be caused primarily by an increase in ocean surface stress in the southeastern Weddell Sea due to thinning of the formerly consolidated sea-ice cover. The projected ice loss at the base of the Filchner-Ronne Ice Shelf represents 80 per cent of the present Antarctic surface mass balance. Thus, the quantification of basal mass loss under changing climate conditions is important for projections regarding the dynamics of Antarctic ice streams and ice shelves, and global sea level rise. PMID:22575964

  12. Projected Duration of the Sea-Ice-Free Season in the Future Alaskan Arctic

    NASA Astrophysics Data System (ADS)

    Wang, M.; Overland, J. E.

    2014-12-01

    The change in the Arctic climate is fast and broad. Among many changes that have been observed, the reduction of sea ice coverage has been one of the most significant factors. Continued reduction in sea ice cover will probably result in longer open water duration, which is important for the shipping industry, marine mammals as well as other component of the local ecosystem. In this study we are to assess future sea ice conditions, particularly the length of open water duration in the Alaskan Arctic over the next few decades using the latest coupled climate models (CMIP5). The Alaskan Arctic, including the Chukchi and the Beaufort Sea, has been a major region of summer sea ice retreat since 2007. Based on the mean of 12 climate models, for the region north of the Bering Strait (70° N), future open-water duration may extend from a current 3-4 months to around five months by 2050. It is about one month shorter along the same latitude over the Beaufort Sea. The difference in the length of ice-free season between the north and the south will remain, but will be smaller in the 21st century compared with current condition. Open-water duration in the Alaskan Arctic expands quickly in these models over the next decades, in contrast to model under-predictions of sea ice loss for the summer minimum over the Arctic wide domain. Uncertainty is generally ±one month estimated from the range of model results. Continued increases in open-water duration over the next two decades will impact regional economic access and potentially alter ecosystems, yet we need to keep in mind that from December through May most of the northern Alaskan Arctic will remain sea ice covered into the second half of the century.

  13. Sufentanil citrate immobilization of Alaskan moose calves.

    PubMed

    Kreeger, Terry J; Kellie, Kalin A

    2012-10-01

    Free-ranging Alaskan moose calves (Alces alces gigas) were immobilized with 0.12 mg/kg sufentanil (S; n=16), 0.12 mg/kg sufentanil plus 0.27 mg/kg xylazine (SX; n=11), or 0.007 mg/kg carfentanil plus 0.36 mg/kg xylazine (CX; n=13). Immobilants were antagonized with 1.2 mg/kg naltrexone (S) or 1.2 mg/kg naltrexone plus 2.4 mg/kg tolazoline (SX, CX). There were no differences in induction (P ≥ 0.29) or processing (P ≥ 0.44) times between groups. Moose given either S or SX had significantly shorter recovery times than moose given CX (P=0.001) and recovery times from S were shorter than from SX (P=0.02). Oxygen saturation values for all groups averaged 85 ± 8%, but were significantly higher (P=0.048) for CX (89 ± 7%) than for S (82 ± 8%). Based on these data, sufentanil at 0.1 mg/kg or sufentanil at 0.1 mg/kg plus xylazine at 0.25 mg/kg could provide effective remote immobilization for Alaskan moose calves and could be substituted for carfentanil or thiafentanil should the need arise. PMID:23060515

  14. Holocene sea surface temperatures in the East African Coastal Current region and their relationship with North Atlantic climate

    NASA Astrophysics Data System (ADS)

    Kuhnert, Henning; Kuhlmann, Holger; Mohtadi, Mahyar; Pätzold, Jürgen

    2013-04-01

    The East African Coastal Current (EACC) is one of the western boundary currents of the Indian Ocean and represents the only pathway for southern water masses to enter the Arabian Sea. Today, sea surface temperatures (SST) in the western boundary currents region covary with those in large parts of the central tropical Indian Ocean. The latter play an important role in global climate by influencing the mean state of the North Atlantic Oscillation (NAO) and associated Atlantic SST anomalies (Hoerling et al., 2001). In the EACC region paleoclimate data are sparse and its Holocene temperature history is unexplored. We present data from a 5 m long sediment core retrieved off northern Tanzania where the EACC flows northward year-round. Proximity to the Pangani River mouth provides a steady sediment supply. We have reconstructed SST from Mg/Ca and stable oxygen isotope ratios (^18O) of the surface-dwelling planktonic foraminifera species Globigerinoides ruber (sensu stricto). Our record spans the time period from 9700 to 1400 years BP at an average temporal resolution of 40 years. The Holocene is characterized by a sequence of intervals representing cool, warm, cool, and intermediate SST, with boundaries at 7.8, 5.6, and 4.4 ka BP. SST anomalies relative to the series mean range from -0.6 to +0.75 ° C. This pattern strikingly resembles a Northwest Atlantic foraminiferal ^18O record (Cléroux et al., 2012), with warm Indian SST corresponding to low Atlantic foraminiferal ^18O (indicating low sea surface density). This matches the modern situation on the interdecadal time-scale, where a warm Indian Ocean leads to a shift of the NAO towards a positive mean state, which is accompanied by SST warming over much of the low- and mid-latitude western Atlantic and a displacement of the Gulf Stream path. We hypothesize that this mechanism also operates on millennial time-scales to explain the obvious similarities in the SST patterns observed in the Northwest Atlantic and western

  15. Current Land Subsidence and Sea Level Rise along the North American Coastal Region: Observations from 10-Year (2005-2014) Closely-Spaced GPS and Tide Gauge Stations

    NASA Astrophysics Data System (ADS)

    Yang, L.; Yu, J.; Kearns, T.; Wang, G.

    2014-12-01

    Strong evidence has proved that the global sea-level is now rising at an increased rate and it is projected to continue to rise. However the rise of the sea-level is not uniform around the world. The local or relative sea-level rise will be of great concern to the coastal regions. The combination of the land subsidence and global sea-level rise causes the relative sea-level to rise. Relative sea-level rise increases the risk of flooding and wetland loss problems in near coastal areas, which in turn have important economic, environmental, and human health consequences for the heavily populated and ecologically important coastal region. However the role played by the coastal land subsidence is commonly absent during the discussion of sea-level rise problems. The sea-level can be measured in two ways: satellite altimetry and tide gauges. The sea-level measured by satellite is called the geocentric sea-level that is relative to earth center and the one measured by tide gauges is called local sea-level that is relative to the land. The tide gauge measurements of the local sea-level do not distinguish between whether the water is rising or the land is subsiding. In some coastal areas, land subsidence is occurring at a higher rate than the geocentric sea-level is rising. This can have a great local effect. GPS technology has proven to be efficient and accurate for measuring and tracking absolute land elevation change. There are about 300 publically available Continuously Operating Reference GPS Stations (CORS) within 15 km from the coastal line along North America. In this study, we use publicly available long-history (> 5 years) CORS data to derive current (2005-2014) coastal subsidence in North America. Absolute coastal sea-level rise will be determined by combing the land subsidence and relative sea-level measurements. This study shows that the relative sea-level of the Alaska area appears to be falling because the land is uplifting; this study also shows that the

  16. Quantitative Index of Physical and Social Vulnerability to Current and Projected Coastal Storm Surge Flooding in New York City

    NASA Astrophysics Data System (ADS)

    Patrick, L.

    2015-12-01

    Sea-level rise throughout the 21st century will result in increased flood exposure as current flood levels are achieved more frequently and new flood levels result in more widespread inundation. To increase the resiliency of coastal communities and allow populations to respond and recover to these hazards, it is important to develop a place-based understanding of how storm surge exposure, impacts, and community vulnerability will change over time. This work uses a GIS-based methodology to develop and map a quantitative index of physical and social vulnerability for New York City populations within existing and predicted flood zones to assess overall risk at the intersection of exposure and vulnerability. This index may be used to inform decision makers about the heterogeneous landscape of community-level vulnerability in New York City. Both the physical and socio-economic impacts of flooding events are often unevenly distributed, with socially vulnerable groups most likely to experience a disproportionate share of the detrimental effects. When both physical and socio-economic vulnerability are present in combination, the risk to populations is exacerbated. The combination of social vulnerability, critical infrastructure at risk, and exposure to hazard provides a metric to rank neighborhood risk to flood hazards through a quantitative vulnerability index that characterizes site-specific levels of risk to flood hazard. Results show that a range of mitigation and hazard preparation strategies, and a variety of response and recovery assistance measures are required to address the diversity of local-level flood risks. For some locations the greatest threat is the physical exposure to floodwaters while in other areas social vulnerability compromises the ability of the community to recover from even low exposure flood events. In many locations several elements of vulnerability overlap to create a heightened overall risk to flood events. These areas may require more

  17. Identifying beach sand sources and pathways in the San Francisco Bay Coastal System through the integration of bed characteristics, geochemical tracers, current measurements, and numerical modeling

    NASA Astrophysics Data System (ADS)

    Barnard, P.; Foxgrover, A. C.; Elias, E.; Erikson, L. H.; Hein, J. R.; McGann, M. L.; Mizell, K.; Rosenbauer, R. J.; Swarzenski, P. W.; Takesue, R. K.; Wong, F. L.; Woodrow, D. L.

    2012-12-01

    A unique, multi-faceted provenance study was performed to definitively establish the primary sources, sinks, and transport pathways of beach sized-sand in the San Francisco Bay Coastal System. This integrative program is based on comprehensive surficial sediment sampling of the San Francisco Bay Coastal System, including the seabed, bay floor, area beaches, adjacent rock units, and major drainages. Analyses of sample morphometrics and biological composition (e.g., foraminifera) were then integrated with a suite of tracers including 87Sr/86Sr and 143Nd/144Nd isotopes, rare earth elements, semi-quantitative X-ray diffraction mineralogy, and heavy minerals, and with process-based numerical modeling, in situ current measurements, and bedform asymmetry, to robustly determine the provenance of beach-sized sand in the region. Cross-validating geochemical analyses, numerical modeling, physical process measurements, and proxy-based techniques (e.g., bedform asymmetry, grain size morphometrics) is proved an effective technique for confidently defining sources, pathways, and sinks of sand in complex coastal-estuarine systems. The consensus results highlight the regional impact of a sharp reduction in the primary sediment source, the Sierras, to the San Francisco Bay Coastal System over the last century in driving erosion of the bay floor, ebb-tidal delta, and the outer coast south of the Golden Gate.A) Calculated transport directions based on the integration of the provenance techniques. B) Number of techniques applied for each grid cell to determine the final transport directions.

  18. Phytoplankton community structure and nitrogen nutrition in Leeuwin Current and coastal waters off the Gascoyne region of Western Australia

    NASA Astrophysics Data System (ADS)

    Hanson, Christine E.; Waite, Anya M.; Thompson, Peter A.; Pattiaratchi, Charitha B.

    2007-04-01

    Within the coastal waters of the eastern Indian Ocean adjacent to Western Australia, we tested the hypothesis that regenerated production (and, by inference, the microbial food web) would predominate in oligotrophic Leeuwin Current (LC) and offshore (OS) surface waters. Conversely, we expected that new production would be more important within the ˜5 times more productive shelf countercurrents (Ningaloo and Capes Currents; NC&CC) and the LC&OS deep chlorophyll maximum (DCM). Phytoplankton species composition and abundance were assessed using both light microscopy and chemotaxonomic methods, and isotopic nitrogen uptake experiments ( 15NO 3-, 15NH 4+) were performed at trace (0.05 μM) and saturating (5.0 μM) levels. Phytoplankton community structure was statistically distinct between LC&OS and countercurrent regions. Picoplankton (unicellular cyanobacteria and prochlorophytes) accounted for a mean of 55-65% of pigment biomass in LC&OS waters, with haptophytes as the other primary contributor (21-32%). Conversely, within countercurrent and shelf regions, diatoms (up to 22%) and haptophytes (up to 57%) were more abundant, although cyanobacteria still played an important role (up to 40% of pigment biomass). Absolute NO 3- uptake rates for all samples ranged between 0.5 and 7.1 nmol L -1 h -1, and in countercurrent waters were not significantly different at the surface (3.0±2.1 nmol L -1 h -1; mean±SD) compared to the DCM (2.7±2.3 nmol L -1 h -1). However, in LC&OS waters, rates were significantly lower at the surface (1.2±0.7 nmol L -1 h -1) than the DCM (3.9±2.5 nmol L -1 h -1; p=0.05). These values represent conservative estimates for the region due to methodological difficulties encountered with nitrogen uptake experiments in these oligotrophic waters. In contrast with the distinct community composition between different water types, mean estimates of the f-ratio were similar across sampling depths and water types: 0.17±0.07 at the surface and 0.16±0.06 at

  19. Characteristics and petrogenesis of Alaskan-type ultramafic-gabbro intrusions, southeastern Alaska

    SciTech Connect

    Loney, R.A. ); Himmelberg, G.R. Univ. of Missouri, Columbia, MO )

    1993-04-01

    Alaskan-type ultramafic-gabbro intrusions occur along a belt that extends from Duke Island to Klukwan in southeastern Alaska and fall into two age groups, 400 to 440 Ma and 100 to 110 Ma. Most of the smaller bodies are magnetite-bearing hornblende clinopyroxenite; the larger ones consist of dunite, wehrlite, olivine clinopyroxenite, with some gabbro, in addition to hornblende clinopyroxenite and hornblendite. Textural, mineralogical, and chemical characteristics of the Alaskan-type ultramafic bodies indicate that they originated by fractional crystallization of a basaltic magma and accumulation in a crustal magma chamber. The Al[sub 2]O[sub 3] content of clinopyroxene shows a marked enrichment with differentiation, suggesting crystallization from progressively more hydrous melts like those characteristics of arc magmas. REE abundance levels and patterns are markedly similar for given rock units in all the bodies studied suggesting that all the bodies were derived by differentiation of closely similar parent magmas under near identical conditions. The exact composition of the primary melt is uncertain but the authors' preferred interpretation is that the parental magma of most Alaskan-type bodies was a subalkaline hydrous basalt. The striking similarity between the REE abundance levels and patterns of the Alaskan-type clinopyroxenites and gabbros, and the clinopyroxenite xenoliths and plutonic gabbros associated with Aleutian Island Arc volcanism, further suggests that the primary magma was probably a hydrous olivine basalt similar to the primary magma proposed for the Aleutian arc lavas. The mineral chemistry and phase equilibria of the ultramafic bodies suggest that they crystallized in magma chambers at depths greater than about 9 km. Except for the Duke Island body, which has sedimentary structures and shows evidence of ubiquitous current activity, most of the other bodies appear to have accumulated under static conditions.

  20. Carbon cycle uncertainty in the Alaskan Arctic

    NASA Astrophysics Data System (ADS)

    Fisher, J. B.; Sikka, M.; Oechel, W. C.; Huntzinger, D. N.; Melton, J. R.; Koven, C. D.; Ahlström, A.; Arain, A. M.; Baker, I.; Chen, J. M.; Ciais, P.; Davidson, C.; Dietze, M.; El-Masri, B.; Hayes, D.; Huntingford, C.; Jain, A.; Levy, P. E.; Lomas, M. R.; Poulter, B.; Price, D.; Sahoo, A. K.; Schaefer, K.; Tian, H.; Tomelleri, E.; Verbeeck, H.; Viovy, N.; Wania, R.; Zeng, N.; Miller, C. E.

    2014-02-01

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

  1. Current Status and Future Prospects for the Assessment of Marine and Coastal Ecosystem Services: A Systematic Review

    PubMed Central

    Liquete, Camino; Piroddi, Chiara; Drakou, Evangelia G.; Gurney, Leigh; Katsanevakis, Stelios; Charef, Aymen; Egoh, Benis

    2013-01-01

    Background Research on ecosystem services has grown exponentially during the last decade. Most of the studies have focused on assessing and mapping terrestrial ecosystem services highlighting a knowledge gap on marine and coastal ecosystem services (MCES) and an urgent need to assess them. Methodology/Principal Findings We reviewed and summarized existing scientific literature related to MCES with the aim of extracting and classifying indicators used to assess and map them. We found 145 papers that specifically assessed marine and coastal ecosystem services from which we extracted 476 indicators. Food provision, in particular fisheries, was the most extensively analyzed MCES while water purification and coastal protection were the most frequently studied regulating and maintenance services. Also recreation and tourism under the cultural services was relatively well assessed. We highlight knowledge gaps regarding the availability of indicators that measure the capacity, flow or benefit derived from each ecosystem service. The majority of the case studies was found in mangroves and coastal wetlands and was mainly concentrated in Europe and North America. Our systematic review highlighted the need of an improved ecosystem service classification for marine and coastal systems, which is herein proposed with definitions and links to previous classifications. Conclusions/Significance This review summarizes the state of available information related to ecosystem services associated with marine and coastal ecosystems. The cataloging of MCES indicators and the integrated classification of MCES provided in this paper establish a background that can facilitate the planning and integration of future assessments. The final goal is to establish a consistent structure and populate it with information able to support the implementation of biodiversity conservation policies. PMID:23844080

  2. Development of Alaskan gas hydrate resources

    SciTech Connect

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

    1991-06-01

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

  3. Characteristic ichthyoplankton taxa in the separation zone of the East Australian Current: Larval assemblages as tracers of coastal mixing

    NASA Astrophysics Data System (ADS)

    Syahailatua, Augy; Roughan, Moninya; Suthers, Iain M.

    2011-03-01

    Ichthyoplankton assemblages were compared between regions dominated by the oligotrophic East Australian Current (EAC) and the inner-shelf waters off southeastern Australia, to determine if the early life history of fish was related to the separation of the EAC from the coast, producing different water masses as well as characteristic taxa. Samples were collected at the surface and in sub-surface waters, at 50 and 100 m isobath stations, during two summer research voyages in November 1998 and January 1999. On both voyages the study region was characterized by coastal and EAC waters in the north (˜31°S), and in the south by topographically induced upwelling (˜31°S), associated with narrowing of the continental shelf and separation of the EAC from the coast. Among the 111 families of larval fish, we observed distinctive assemblages of ichthyoplankton associated with the two different water masses. A greater abundance of the Carangidae, Labridae, Lutjanidae, Microcanthidae, Myctophidae and Scombridae was associated with the nutrient poor EAC water mass, while the Callionymidae, Clupeidae, Platycephalidae and Sillaginidae were mostly found in the cooler and/or fresher inner-shelf water mass. We assessed these patterns with opportunistic samples from an unusual, wind-driven upwelling event in the north (˜31°S) earlier in the November voyage. The relative abundance of these 10 characteristic families distinguished this wind-driven upwelling event from the subsequent relaxation and predominance of the EAC assemblage at this location just 6 d later. Distinctive and abundant families such as larval clupeids, relative to larval carangids, could be a useful marker of inner-shelf, EAC and mixed water masses in the absence of robust hydrographic data. This and related studies indicate contrast in early life histories of Sardinops sagax and Trachurus spp., which appear to spawn respectively in the inner-shelf and outer-shelf waters. The post-flexion stages of S. sagax

  4. The Ghost in the Shell : Local and Remote Forcing of a Coastal Bivalve Inhabiting the Humboldt Current System

    NASA Astrophysics Data System (ADS)

    Gosselin, M.

    2014-12-01

    The external skeleton of mollusc bivalves, the shell, can furnish a recording of the environmental changes to which the organisms and population are exposed during their lives. The bivalve's growth is subjected to the thermocline variability; which itself is affected by environmental and climatic events. A highly variable environment such as the Humboldt current system (HCS) requires tools capable of recording its variations over a wide range of periodicities. Upwelling, Coastal trapped waves (CTWs), El Niño Southern Oscillation, and Pacific decadal oscillation events contribute to this environmental and climatic variability. The thermocline depth is modified by these different events at their own time-scales (respectively, daily to weekly, intraseasonally, interseasonally to interannually, and on a decadal scale). The thermocline variation translates into changes in Sea surface temperature (SST) and in the qualitative and quantitative productivity of phytoplankton. These two environmental factors are critical to bivalve growth.The sclerochronological (increment width) and sclerochemical (δ18O and δ13C) study consisted on the analysis of the Chilean bivalve Eurhomalea rufa, collected in 2005, as a recorder of the environmental HCS variability. The calibration step identified daily, monthly, and annual marks in the growth patterns of E. rufa. The results confirmed that the thermocline variability mainly drives the bivalve's activity and led to the establishment of a paleotemperature equation. Moreover, periodogram and wavelet analyses exposed the respective impacts of each environmental event from daily to interannual periodicities. In particular, the growth pattern of E. rufa follows SST variability at an intraseasonal periodicity (~ 60 days) which is remotely induced by CTWs. CTWs are generated by Kelvin oceanic waves, which are formed primarily by eastward equatorial Pacific winds (e.g. Shaffer et al. 1997; Montecino and Lange 2009).Sclerochronological studies

  5. Inhibition of mixed-layer deepening during winter in the northeastern Arabian Sea by the West India Coastal Current

    NASA Astrophysics Data System (ADS)

    Shankar, D.; Remya, R.; Vinayachandran, P. N.; Chatterjee, Abhisek; Behera, Ambica

    2015-10-01

    Though the deep mixed layers (MLs) that form in the northeastern Arabian Sea (NEAS) during the winter monsoon (November-February) have been attributed to convective mixing driven by dry, cool northeasterly winds from the Indian subcontinent, data show that the deepest MLs occur in the northern NEAS and the maxima of latent-heat and net heat fluxes in the southern NEAS. We use an oceanic general circulation model to show that the deep MLs in the NEAS extend up to ~20°N till the end of December, but are restricted poleward of ~22°N (~23°N) in January (February). This progressive restriction of the deep mixed layers within the NEAS is due to poleward advection of water of lower salinity by the West India Coastal Current (WICC). The deep MLs are sustained till February in the northern NEAS because convective mixing deepens the ML before the waters of lower salinity reach this region and the wind stirring and convective overturning generate sufficient turbulent energy for the ML to maintain the depth attained in January. Though the atmospheric fluxes tend to cool the ML in the southern NEAS, this cooling is countered by the warming due to horizontal advection. Likewise, the cooling due to entrainment, which continues in the southern NEAS even as the ML shallows during January-February, is almost cancelled by the warming caused by a downwelling vertical velocity field. Therefore, the SST changes very little during December-February even as the ML shallows dramatically in the southern NEAS. These deep MLs of the NEAS also preclude a strong intraseasonal response to the intraseasonal variability in the fluxes. This role of horizontal advection implies that the ML depth in the NEAS is determined by an interplay of physical processes that are forced differently. The convective mixing depends on processes that are local to the region, but the advection is due to the WICC, whose seasonal cycle is primarily forced by remote winds. By inhibiting the formation of deep MLs in

  6. A Current and Retrospective Landscape-Level C Budget for the Fluxnet-Canada Coastal British Columbia Station (Oyster River).

    NASA Astrophysics Data System (ADS)

    Trofymow, J. A.; Stinson, G.; Kurz, W.

    2006-12-01

    A retrospective carbon (C ) budget for the Fluxnet-Canada coastal BC Station (5 x 5 km Oyster River Area) for the period 1920 to 2005 was developed using the spatially-explicit version of the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3). CBM-CFS3 is an inventory-based C budget modeling tool that has been used to simulate forest C dynamics at national, regional, and operational scales. A current (circa 2000) forest inventory map for the Oyster River Area was compiled using data provided by forest companies (TimberWest and Island Timberlands). This inventory was overlaid with historic disturbance maps and orthophotographs to generate a coverage of forest cover polygons with unique disturbance histories. A 1920 timber cruise map was then used to help estimate the volume, cover type, and age of the forest in each polygon in 1920. Data were loaded into the CBM-CFS3 initialization routine and the model was then used to simulate the forest dynamics and C budget for the 85-year period. The C budget of the Oyster River Area is strongly tied to its disturbance history. In 1920, old-growth forest covered the majority of the study area and net C flux was neutral or small. In the 1930's and 40's, ground fires, clear-cut harvesting (using railroad logging), and slash burning resulted in a significant loss of biomass C and a substantial flux of C into dead organic matter, the atmosphere, and wood product pools (area net average C loss 5 - 20 Mg C/ha/yr). A gradual recovery of ecosystem C stocks followed this period of high disturbance activity but the area remained a significant C source, and did not become a net C sink until well into the 1950's. From 1960 through 1987 disturbance was minimal and the area remained a C sink (area average net uptake 2 - 6 Mg C/ha/yr). As harvesting of the second-growth forest began in the late 1980's, the C budget of the area was once again dominated by disturbances, albeit buffered by ongoing C uptake by living biomass in the

  7. Inhibition of mixed-layer deepening during winter in the northeastern Arabian Sea by the West India Coastal Current

    NASA Astrophysics Data System (ADS)

    Shankar, D.; Remya, R.; Vinayachandran, P. N.; Chatterjee, Abhisek; Behera, Ambica

    2016-08-01

    Though the deep mixed layers (MLs) that form in the northeastern Arabian Sea (NEAS) during the winter monsoon (November-February) have been attributed to convective mixing driven by dry, cool northeasterly winds from the Indian subcontinent, data show that the deepest MLs occur in the northern NEAS and the maxima of latent-heat and net heat fluxes in the southern NEAS. We use an oceanic general circulation model to show that the deep MLs in the NEAS extend up to ~20°N till the end of December, but are restricted poleward of ~22°N (~23°N) in January (February). This progressive restriction of the deep mixed layers within the NEAS is due to poleward advection of water of lower salinity by the West India Coastal Current (WICC). The deep MLs are sustained till February in the northern NEAS because convective mixing deepens the ML before the waters of lower salinity reach this region and the wind stirring and convective overturning generate sufficient turbulent energy for the ML to maintain the depth attained in January. Though the atmospheric fluxes tend to cool the ML in the southern NEAS, this cooling is countered by the warming due to horizontal advection. Likewise, the cooling due to entrainment, which continues in the southern NEAS even as the ML shallows during January-February, is almost cancelled by the warming caused by a downwelling vertical velocity field. Therefore, the SST changes very little during December-February even as the ML shallows dramatically in the southern NEAS. These deep MLs of the NEAS also preclude a strong intraseasonal response to the intraseasonal variability in the fluxes. This role of horizontal advection implies that the ML depth in the NEAS is determined by an interplay of physical processes that are forced differently. The convective mixing depends on processes that are local to the region, but the advection is due to the WICC, whose seasonal cycle is primarily forced by remote winds. By inhibiting the formation of deep MLs in

  8. Controlling the upstream conditions of a coastal current interacting with a gulf circulation by a 4D-variational data assimilation method

    NASA Astrophysics Data System (ADS)

    Taillandier, V.; Echevin, V.; Devenon, J.-L.; Mortier, L.

    2003-04-01

    The interaction of a coastal current with a shelf is studied with a 4D-variational data assimilation method (4DVAR) used here as a diagnostic tool to get a better insight in a dynamical process. We focus on the determination and the estimation of all upstream conditions able to control the intrusion of the coastal current inside the gulf. Academic representations of a density current flowing in a stratified ocean are involved during a week time window and inside an open basin embedding the shelf and its slope. This sensitivity study is based on twin experiments: they consist in the assimilation of synthetic data sets which are extracted from model solutions inside the gulf. Then, the optimal open boundary conditions given by the 4DVAR algorithm reveal the upstream parameters which control the intrusion process. Precisely in the western Mediterranean basin, intrusions of the Liguro-Provencal Current (LPC) into the Gulf of Lions have been observed. Among the relevant causes of this phenomenon, the uptstream dynamical behaviour of the LPC is especially pointed out.

  9. An extended velocity projection method for estimating the subsurface current and density structure for coastal plume regions: An application to the Chesapeake Bay outflow plume

    NASA Astrophysics Data System (ADS)

    Gangopadhyay, Avijit; Shen, Colin Y.; Marmorino, George O.; Mied, Richard P.; Lindemann, Gloria J.

    2005-07-01

    We describe a method for estimating subsurface current and density structure in a coastal region dominated by a plume from a set of surface observations of velocity and density. A detailed application of the method is shown via a case study of the Chesapeake Bay in November 1997. The proposed technique relies on developing a 'plume feature model' from theoretical models and past synoptic observational data sets, and incorporating the feature model into the previously developed velocity projection method [J. Geophys. Res. 106 (2001) 6973] to obtain subsurface current structure within the Ekman layer depth. The primary feature model parameters include the location and extent of the frontal boundary, a simplified gravity current structure, and the spatial gradient of salinity across the frontal head of the plume, which are inferred from remote sensing or minimal strategic in situ observations. For the Chesapeake Bay case study, we show how the proposed method, referred to as 'extended velocity projection', can produce estimates of plume current structure consistent with available ADCP profiles. We assess the sensitivity of the results to feature model parameters, and identify the resolution of spatial salinity gradient as being particularly important. The difference between the density-stratified estimate and the ADCP data can be used to calibrate and improve the zero-order dynamic feature model parameters. This synergistic approach with the extended velocity projection method should be applicable to other coastal plumes and possibly other shallow water features.

  10. Retrospective ecotoxicological data and current information needs for terrestrial vertebrates residing in coastal habitat of the United States.

    PubMed

    Rattner, B A; Eisenreich, K M; Golden, N H; McKernan, M A; Hothem, R L; Custer, T W

    2005-08-01

    The Contaminant Exposure and Effects-Terrestrial Vertebrates (CEE-TV) database was developed to conduct simple searches for ecotoxicological information, examine exposure trends, and identify significant data gaps. The CEE-TV database contains 16,696 data records on free-ranging amphibians, reptiles, birds, and mammals residing in estuarine and coastal habitats of the Atlantic, Gulf, and Pacific coasts, Alaska, Hawaii, and the Great Lakes. Information in the database was derived from over 1800 source documents, representing 483 unique species (about 252,000 individuals), with sample collection dates spanning from 1884 to 2003. The majority of the records contain exposure data (generally contaminant concentrations) on a limited number (n = 209) of chlorinated and brominated compounds, cholinesterase-inhibiting pesticides, economic poisons, metals, and petroleum hydrocarbons, whereas only 9.3% of the records contain biomarker or bioindicator effects data. Temporal examination of exposure data provides evidence of declining concentrations of certain organochlorine pesticides in some avian species (e.g., ospreys, Pandion haliaetus), and an apparent increase in the detection and possibly the incidence of avian die-offs related to cholinesterase-inhibiting pesticides. To identify spatial data gaps, 11,360 database records with specific sampling locations were combined with the boundaries of coastal watersheds, and National Wildlife Refuge and National Park units. Terrestrial vertebrate ecotoxicological data were lacking in 41.9% of 464 coastal watersheds in the continental United States. Recent (1990-2003) terrestrial vertebrate contaminant exposure or effects data were available for only about half of the National Wildlife Refuge and National Park units in the geographic area encompassed by the database. When these data gaps were overlaid on watersheds exhibiting serious water quality problems and/or high vulnerability to pollution, 72 coastal watersheds, and 76

  11. Coastal circulation and sediment dynamics in Hanalei Bay, Kauai. Part I: Measurements of waves, currents, temperature, salinity and turbidity : June - August, 2005

    USGS Publications Warehouse

    Storlazzi, Curt D.; Presto, M. Kathy; Logan, Joshua B.; Field, Michael E.

    2006-01-01

    Introduction: High-resolution measurements of waves, currents, water levels, temperature, salinity and turbidity were made in Hanalei Bay, northern Kauai, Hawaii, during the summer of 2005 to better understand coastal circulation and sediment dynamics in coral reef habitats. A series of bottom-mounted instrument packages were deployed in water depths of 10 m or less to collect long-term, high-resolution measurements of waves, currents, water levels, temperature, salinity and turbidity. These data were supplemented with a series of vertical instrument casts to characterize the vertical and spatial variability in water column properties within the bay. The purpose of these measurements was to collect hydrographic data to learn how waves, currents and water column properties vary spatially and temporally in an embayment that hosts a nearshore coral reef ecosystem adjacent to a major river drainage. These measurements support the ongoing process studies being conducted as part of the U.S. Geological Survey (USGS) Coastal and Marine Geology Program's Coral Reef Project; the ultimate goal is to better understand the transport mechanisms of sediment, larvae, pollutants and other particles in coral reef settings. This report, the first part in a series, describes data acquisition, processing and analysis.

  12. Using the Gulf of Maine Ocean Observing System for Preliminary Characterization of the Seasonal and Interannual Variability of the Gulf of Maine Coastal Current System

    NASA Astrophysics Data System (ADS)

    Pettigrew, N. R.

    2004-12-01

    The Gulf of Maine Ocean Observing System (GoMOOS) has been established as a sustained, comprehensive, real-time, observing system that includes an array of moored physical and optical sensors, shore based long-range CODAR for surface current mapping, numerical circulation and wave modeling, satellite observations, and web delivery of data and data products. The GoMOOS moored array presently consists of 10 solar-powered, automated buoy systems that telemeter data hourly via cellular phone, iridium, or GOES satellite transmitters. The buoys are deployed within the major bays and estuaries of the Gulf, along the Continental Shelf from Nova Scotia to Massachusetts, in the Jordan Basin, and in the Northeast Channel, which represents the only pathway of exchange with the North Atlantic at depths exceeding 100 m. The first buoys were deployed in the summer of 2001, and the system is now beginning to provide time series long enough to provide an indication of seasonal and interannual variability of the flow and physical properties of the complex and little understood Gulf of Maine Coastal Current system. Preliminary analysis suggests a strong seasonal cycle and significant interannual variability that combine to produce previously unknown reversals of the typical southwestward flow of the coastal current.

  13. 40 CFR 408.50 - Applicability; description of the remote Alaskan crab meat processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... remote Alaskan crab meat processing subcategory. 408.50 Section 408.50 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Remote Alaskan Crab Meat Processing Subcategory § 408.50 Applicability; description of the remote Alaskan crab meat processing subcategory. The provisions of this subpart...

  14. 40 CFR 408.50 - Applicability; description of the remote Alaskan crab meat processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... remote Alaskan crab meat processing subcategory. 408.50 Section 408.50 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Remote Alaskan Crab Meat Processing Subcategory § 408.50 Applicability; description of the remote Alaskan crab meat processing subcategory. The provisions of this subpart...

  15. 40 CFR 408.50 - Applicability; description of the remote Alaskan crab meat processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... remote Alaskan crab meat processing subcategory. 408.50 Section 408.50 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Remote Alaskan Crab Meat Processing Subcategory § 408.50 Applicability; description of the remote Alaskan crab meat processing subcategory. The provisions of this subpart...

  16. 40 CFR 408.50 - Applicability; description of the remote Alaskan crab meat processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... remote Alaskan crab meat processing subcategory. 408.50 Section 408.50 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Remote Alaskan Crab Meat Processing Subcategory § 408.50 Applicability; description of the remote Alaskan crab meat processing subcategory. The provisions of this subpart...

  17. 40 CFR 408.50 - Applicability; description of the remote Alaskan crab meat processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... remote Alaskan crab meat processing subcategory. 408.50 Section 408.50 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Remote Alaskan Crab Meat Processing Subcategory § 408.50 Applicability; description of the remote Alaskan crab meat processing subcategory. The provisions of this subpart...

  18. 40 CFR 408.170 - Applicability; description of the Alaskan mechanized salmon processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Alaskan mechanized salmon processing subcategory. 408.170 Section 408.170 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Mechanized Salmon Processing Subcategory § 408.170 Applicability; description of the Alaskan mechanized salmon processing subcategory. The provisions of this subpart...

  19. 40 CFR 408.170 - Applicability; description of the Alaskan mechanized salmon processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Alaskan mechanized salmon processing subcategory. 408.170 Section 408.170 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Mechanized Salmon Processing Subcategory § 408.170 Applicability; description of the Alaskan mechanized salmon processing subcategory. The provisions of this subpart...

  20. 40 CFR 408.170 - Applicability; description of the Alaskan mechanized salmon processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Alaskan mechanized salmon processing subcategory. 408.170 Section 408.170 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Mechanized Salmon Processing Subcategory § 408.170 Applicability; description of the Alaskan mechanized salmon processing subcategory. The provisions of this subpart...

  1. 40 CFR 408.170 - Applicability; description of the Alaskan mechanized salmon processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Alaskan mechanized salmon processing subcategory. 408.170 Section 408.170 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Mechanized Salmon Processing Subcategory § 408.170 Applicability; description of the Alaskan mechanized salmon processing subcategory. The provisions of this subpart...

  2. 40 CFR 408.170 - Applicability; description of the Alaskan mechanized salmon processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Alaskan mechanized salmon processing subcategory. 408.170 Section 408.170 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Mechanized Salmon Processing Subcategory § 408.170 Applicability; description of the Alaskan mechanized salmon processing subcategory. The provisions of this subpart...

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

    ERIC Educational Resources Information Center

    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…

  4. American Indian Policy Review Commission Special Joint Task Force Report on Alaskan Native Issues.

    ERIC Educational Resources Information Center

    Congress of the U.S. Washington, DC. American Indian Policy Review Commission.

    Impact of the Alaskan Native Claims Settlement Act (ANCSA) on Alaskan Natives, particularly at village levels, is the focus of a joint task force report on Alaskan Native issues. Prepared for the American Indian Policy Review Commission, the report is the work of representatives from task forces on tribal government, federal, state, and tribal…

  5. 40 CFR 408.200 - Applicability; description of the Alaskan bottom fish processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Alaskan bottom fish processing subcategory. 408.200 Section 408.200 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Bottom Fish Processing Subcategory § 408.200 Applicability; description of the Alaskan bottom fish processing subcategory. The provisions of this subpart are...

  6. 40 CFR 408.200 - Applicability; description of the Alaskan bottom fish processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Alaskan bottom fish processing subcategory. 408.200 Section 408.200 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Bottom Fish Processing Subcategory § 408.200 Applicability; description of the Alaskan bottom fish processing subcategory. The provisions of this subpart are...

  7. 40 CFR 408.160 - Applicability; description of the Alaskan hand-butchered salmon processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Alaskan hand-butchered salmon processing subcategory. 408.160 Section 408.160 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Hand-Butchered Salmon Processing Subcategory § 408.160 Applicability; description of the Alaskan hand-butchered salmon processing subcategory. The provisions of this subpart...

  8. 40 CFR 408.160 - Applicability; description of the Alaskan hand-butchered salmon processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Alaskan hand-butchered salmon processing subcategory. 408.160 Section 408.160 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Hand-Butchered Salmon Processing Subcategory § 408.160 Applicability; description of the Alaskan hand-butchered salmon processing subcategory. The provisions of this subpart...

  9. 40 CFR 408.160 - Applicability; description of the Alaskan hand-butchered salmon processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Alaskan hand-butchered salmon processing subcategory. 408.160 Section 408.160 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Hand-Butchered Salmon Processing Subcategory § 408.160 Applicability; description of the Alaskan hand-butchered salmon processing subcategory. The provisions of this subpart...

  10. 40 CFR 408.160 - Applicability; description of the Alaskan hand-butchered salmon processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Alaskan hand-butchered salmon processing subcategory. 408.160 Section 408.160 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Hand-Butchered Salmon Processing Subcategory § 408.160 Applicability; description of the Alaskan hand-butchered salmon processing subcategory. The provisions of this subpart...

  11. 40 CFR 408.160 - Applicability; description of the Alaskan hand-butchered salmon processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Alaskan hand-butchered salmon processing subcategory. 408.160 Section 408.160 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Hand-Butchered Salmon Processing Subcategory § 408.160 Applicability; description of the Alaskan hand-butchered salmon processing subcategory. The provisions of this subpart...

  12. 40 CFR 408.310 - Applicability; description of the Alaskan herring fillet processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Alaskan herring fillet processing subcategory. 408.310 Section 408.310 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Herring Fillet Processing Subcategory § 408.310 Applicability; description of the Alaskan herring fillet processing subcategory. The provisions of this subpart...

  13. 40 CFR 408.320 - Applicability; description of the non-Alaskan herring fillet processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-Alaskan herring fillet processing subcategory. 408.320 Section 408.320 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Herring Fillet Processing Subcategory § 408.320 Applicability; description of the non-Alaskan herring fillet processing subcategory. The provisions of this subpart...

  14. 40 CFR 408.320 - Applicability; description of the non-Alaskan herring fillet processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-Alaskan herring fillet processing subcategory. 408.320 Section 408.320 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Herring Fillet Processing Subcategory § 408.320 Applicability; description of the non-Alaskan herring fillet processing subcategory. The provisions of this subpart...

  15. 40 CFR 408.320 - Applicability; description of the non-Alaskan herring fillet processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-Alaskan herring fillet processing subcategory. 408.320 Section 408.320 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Herring Fillet Processing Subcategory § 408.320 Applicability; description of the non-Alaskan herring fillet processing subcategory. The provisions of this subpart...

  16. 40 CFR 408.310 - Applicability; description of the Alaskan herring fillet processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Alaskan herring fillet processing subcategory. 408.310 Section 408.310 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Herring Fillet Processing Subcategory § 408.310 Applicability; description of the Alaskan herring fillet processing subcategory. The provisions of this subpart...

  17. 40 CFR 408.310 - Applicability; description of the Alaskan herring fillet processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Alaskan herring fillet processing subcategory. 408.310 Section 408.310 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Herring Fillet Processing Subcategory § 408.310 Applicability; description of the Alaskan herring fillet processing subcategory. The provisions of this subpart...

  18. 40 CFR 408.310 - Applicability; description of the Alaskan herring fillet processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Alaskan herring fillet processing subcategory. 408.310 Section 408.310 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Herring Fillet Processing Subcategory § 408.310 Applicability; description of the Alaskan herring fillet processing subcategory. The provisions of this subpart...

  19. 40 CFR 408.320 - Applicability; description of the non-Alaskan herring fillet processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-Alaskan herring fillet processing subcategory. 408.320 Section 408.320 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Herring Fillet Processing Subcategory § 408.320 Applicability; description of the non-Alaskan herring fillet processing subcategory. The provisions of this subpart...

  20. 40 CFR 408.310 - Applicability; description of the Alaskan herring fillet processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Alaskan herring fillet processing subcategory. 408.310 Section 408.310 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Herring Fillet Processing Subcategory § 408.310 Applicability; description of the Alaskan herring fillet processing subcategory. The provisions of this subpart...

  1. 40 CFR 408.320 - Applicability; description of the non-Alaskan herring fillet processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-Alaskan herring fillet processing subcategory. 408.320 Section 408.320 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Herring Fillet Processing Subcategory § 408.320 Applicability; description of the non-Alaskan herring fillet processing subcategory. The provisions of this subpart...

  2. 40 CFR 408.90 - Applicability; description of the non-remote Alaskan shrimp processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-remote Alaskan shrimp processing subcategory. 408.90 Section 408.90 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Shrimp Processing Subcategory § 408.90 Applicability; description of the non-remote Alaskan shrimp processing subcategory. The provisions of this subpart...

  3. 40 CFR 408.100 - Applicability; description of the remote Alaskan shrimp processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... remote Alaskan shrimp processing subcategory. 408.100 Section 408.100 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Remote Alaskan Shrimp Processing Subcategory § 408.100 Applicability; description of the remote Alaskan shrimp processing subcategory. The provisions of this subpart are...

  4. 40 CFR 408.100 - Applicability; description of the remote Alaskan shrimp processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... remote Alaskan shrimp processing subcategory. 408.100 Section 408.100 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Remote Alaskan Shrimp Processing Subcategory § 408.100 Applicability; description of the remote Alaskan shrimp processing subcategory. The provisions of this subpart are...

  5. 40 CFR 408.90 - Applicability; description of the non-remote Alaskan shrimp processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-remote Alaskan shrimp processing subcategory. 408.90 Section 408.90 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Shrimp Processing Subcategory § 408.90 Applicability; description of the non-remote Alaskan shrimp processing subcategory. The provisions of this subpart...

  6. 40 CFR 408.100 - Applicability; description of the remote Alaskan shrimp processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... remote Alaskan shrimp processing subcategory. 408.100 Section 408.100 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Remote Alaskan Shrimp Processing Subcategory § 408.100 Applicability; description of the remote Alaskan shrimp processing subcategory. The provisions of this subpart are...

  7. 40 CFR 408.90 - Applicability; description of the non-remote Alaskan shrimp processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-remote Alaskan shrimp processing subcategory. 408.90 Section 408.90 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Shrimp Processing Subcategory § 408.90 Applicability; description of the non-remote Alaskan shrimp processing subcategory. The provisions of this subpart...

  8. 40 CFR 408.90 - Applicability; description of the non-remote Alaskan shrimp processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-remote Alaskan shrimp processing subcategory. 408.90 Section 408.90 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Shrimp Processing Subcategory § 408.90 Applicability; description of the non-remote Alaskan shrimp processing subcategory. The provisions of this subpart...

  9. 40 CFR 408.100 - Applicability; description of the remote Alaskan shrimp processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... remote Alaskan shrimp processing subcategory. 408.100 Section 408.100 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Remote Alaskan Shrimp Processing Subcategory § 408.100 Applicability; description of the remote Alaskan shrimp processing subcategory. The provisions of this subpart are...

  10. 40 CFR 408.90 - Applicability; description of the non-remote Alaskan shrimp processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-remote Alaskan shrimp processing subcategory. 408.90 Section 408.90 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Shrimp Processing Subcategory § 408.90 Applicability; description of the non-remote Alaskan shrimp processing subcategory. The provisions of this subpart...

  11. 40 CFR 408.100 - Applicability; description of the remote Alaskan shrimp processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... remote Alaskan shrimp processing subcategory. 408.100 Section 408.100 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Remote Alaskan Shrimp Processing Subcategory § 408.100 Applicability; description of the remote Alaskan shrimp processing subcategory. The provisions of this subpart are...

  12. 40 CFR 408.200 - Applicability; description of the Alaskan bottom fish processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Alaskan bottom fish processing subcategory. 408.200 Section 408.200 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Bottom Fish Processing Subcategory § 408.200 Applicability; description of the Alaskan bottom fish processing subcategory. The provisions of this subpart are...

  13. 40 CFR 408.200 - Applicability; description of the Alaskan bottom fish processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Alaskan bottom fish processing subcategory. 408.200 Section 408.200 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Bottom Fish Processing Subcategory § 408.200 Applicability; description of the Alaskan bottom fish processing subcategory. The provisions of this subpart are...

  14. 40 CFR 408.200 - Applicability; description of the Alaskan bottom fish processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Alaskan bottom fish processing subcategory. 408.200 Section 408.200 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Bottom Fish Processing Subcategory § 408.200 Applicability; description of the Alaskan bottom fish processing subcategory. The provisions of this subpart are...

  15. Experiences of Alaskan parents with children hospitalized for respiratory syncytial virus treatment.

    PubMed

    Yael Kopacz, Nicole; Predeger, Elizabeth; Kelley, Colleen M

    2013-01-01

    The purpose of this study was to describe the experiences of Alaskan parents with children hospitalized for the treatment of the respiratory syncytial virus (RSV). Six parents participated in a qualitative descriptive study composed of individual interviews. Using content analysis, three major themes emerged: "RSV is scary," "Lots of stress; little rest" and "At what point does it become a Bingo? He's going to the hospital." Findings provided further insight into the educational needs of the participants. Advanced practice registered nurses can translate insights provided by the participants into crucial knowledge needed for the care of families at heightened risk and currently experiencing RSV. PMID:23531460

  16. Thematic mapper study of Alaskan ophiolites

    NASA Technical Reports Server (NTRS)

    Bird, John M.

    1988-01-01

    The two principle objectives of the project Thematic Mapper Study of Alaskan Ophiolites were to further develop techniques for producing geologic maps, and to study the tectonics of the ophiolite terrains of the Brooks Range and Ruby Geanticline of northern Alaska. Ophiolites, sections of oceanic lithosphere emplaced along island arcs and continental margins, are important to the understanding of mountain belt evolution. Ophiolites also provide an opportunity to study the structural, lithologic, and geochemical characteristics of ocean lithosphere, yielding a better understanding of the processes forming lithosphere. The first part of the report is a description of the methods and results of the TM mapping and gravity modeling. The second part includes papers being prepared for publication. These papers are the following: (1) an analysis of basalt spectral variations; (2) a study of basalt geochemical variations; (3) an examination of the cooling history of the ophiolites using radiometric data; (4) an analysis of shortening produced by thrusting during the Brooks Range orogeny; and (5) a study of an ophiolite using digital aeromagnetic and topographic data. Additional papers are in preparation.

  17. Coastal circulation and sediment dynamics along West Maui, Hawaii; PART IV: measurements of waves, currents, temperature, salinity and turbidity in Honolua Bay, Northwest Maui: 2003-2004

    USGS Publications Warehouse

    Storlazzi, Curt D.; Presto, M. Kathy

    2005-01-01

    High-resolution measurements of waves, currents, water levels, temperature, salinity and turbidity were made in Honolua Bay, northwest Maui, Hawaii, during 2003 and 2004 to better understand coastal dynamics in coral reef habitats. Measurements were acquired through two different collection methods. Two hydrographic survey cruises were conducted to acquire spatially-extensive, but temporally-limited, three-dimensional measurements of currents, temperature, salinity and turbidity in the winter and summer of 2003. From mid 2003 through early 2004, a bottom-mounted instrument package was deployed in a water depth of 10 m to collect long-term, single-point high-resolution measurements of waves, currents, water levels, temperature, salinity and turbidity. The purpose of these measurements was to collect hydrographic data to learn how waves, currents and water column properties such as water temperature, salinity and turbidity vary spatially and temporally in a near-shore coral reef system adjacent to a major stream drainage. These measurements support the ongoing process studies being conducted as part of the U.S. Geological Survey (USGS) Coastal and Marine Geology Program's Coral Reef Project; the ultimate goal is to better understand the transport mechanisms of sediment, larvae, pollutants and other particles in coral reef settings. This report, the final part in a series, describes data acquisition, processing and analysis. Previous reports provided data and results on: Long-term measurements of currents, temperature, salinity and turbidity off Kahana (PART I), the spatial structure of currents, temperature, salinity and suspended sediment along West Maui (PART II), and flow and coral larvae and sediment dynamics during the 2003 summer spawning season (PART III).

  18. Coastal Circulation and Sediment Dynamics in Hanalei Bay, Kaua'i, Part IV, Measurements of Waves, Currents, Temperature, Salinity, and Turbidity, June-September 2006

    USGS Publications Warehouse

    Storlazzi, Curt D.; Presto, M. Katherine; Logan, Joshua B.; Field, Michael E.

    2008-01-01

    High-resolution measurements of waves, currents, water levels, temperature, salinity and turbidity were made in Hanalei Bay, northern Kaua'i, Hawai'i, during the summer of 2006 to better understand coastal circulation, sediment dynamics, and the potential impact of a river flood in a coral reef-lined embayment during quiescent summer conditions. A series of bottommounted instrument packages were deployed in water depths of 10 m or less to collect long-term, high-resolution measurements of waves, currents, water levels, temperature, salinity, and turbidity. These data were supplemented with a series of profiles through the water column to characterize the vertical and spatial variability in water column properties within the bay. These measurements support the ongoing process studies being conducted as part of the U.S. Geological Survey (USGS) Coastal and Marine Geology Program's Pacific Coral Reef Project; the ultimate goal is to better understand the transport mechanisms of sediment, larvae, pollutants, and other particles in coral reef settings. Information regarding the USGS study conducted in Hanalei Bay during the 2005 summer is available in Storlazzi and others (2006), Draut and others (2006) and Carr and others (2006). This report, the last part in a series, describes data acquisition, processing, and analysis for the 2006 summer data set.

  19. Spring-time distributions of migratory marine birds in the southern California Current: Oceanic eddy associations and coastal habitat hotspots over 17 years

    NASA Astrophysics Data System (ADS)

    Yen, P. P. W.; Sydeman, W. J.; Bograd, S. J.; Hyrenbach, K. D.

    2006-02-01

    We used a 17-year time series of shipboard observations to address the hypothesis that marine birds associate with persistent hydrographic features in the southern California Current System (CCS). Overall, approximately 27,000 km of ocean habitat were surveyed, averaging 1600 km per cruise. We identified mesoscale features (eddy centers and the core of the California Current), based on dynamic height anomalies, and considered habitat associations for seven migratory seabird species: black-footed albatross ( Phoebastria nigripes), Cook's petrel ( Pterodroma cookii), Leach's storm-petrel ( Oceanodroma leucorhoa), dark shearwaters (mainly sooty shearwater Puffinus griseus, with a few short-tailed shearwaters Puffinus tenuirostris), northern fulmar ( Fulmarus glacialis), red phalarope ( Phalaropus fulicaria), and red-necked phalarope ( Phalaropus lobatus). We explored associations (presence/absence and density relationships) of marine birds with mesoscale features (eddies, current jet) and metrics of primary productivity (chlorophyll a and nitrate concentrations). Mesoscale eddies were consistently identified in the study region, but were spatially and temporally variable. The resolved eddies were large-scale features associated with meanders of the equatorward-flowing California Current. Cook's petrel was found offshore with no specific habitat affinities. Black-footed albatross, red phalarope, and Leach's storm petrel were found in association with offshore eddies and/or the core of the California Current, but the functional relationship for these species varied, possibly reflecting differences in flight capabilities. The more coastal species, including the shearwaters, fulmar, and red-necked phalarope, were positively associated with proxies of primary productivity. Of the hydrographic habitats considered, the upwelling region of Point Conception appears to be an important "hotspot" of sustained primary production and marine bird concentrations. Point Conception and

  20. Clay minerals and gravels of late Pleistocene interstadial coastal sediments above the current sea level, south coast of Korea

    NASA Astrophysics Data System (ADS)

    Yang, D. Y.; Kim, J. C.; Lim, J.; Yi, S.; Nahm, W. H.; Kim, J. Y.; Han, M.

    2015-12-01

    At nowadays, the severe greenhouse effect causes rapid sea level rise around the Korea Peninsula. Paleo-climate researches have been concentrating on hydrological activities during the mid-Holocene optimum and the last interglacial period to use the paleo-analogues data in predicting the future hydrological environments. The previous studies on the late Pleistocene interstadial coastal sediments have primarily been biased towards the terraces of the east coast in the Korean Peninsula. According to the results, the last interglacial marine terraces of the east coast were existed at 18 m in elevation. Uplift rate of them was presumed to be 0.1mm/year (Choi, 2006). Also, the stratigraphy of the Quaternary coastal deposits of the Yellow Sea has been suggested by Park et al. (1998) and Lim et al. (2003). In recent, Jang et al. (2014) reported the OSL dated Eemian marine deposit along the southwest coast of Korea. However, the age-equivalent outcrops of the south coast are not discovered yet. The first outcrops of the late Pleistocene interstadial coastal sediment above the present sea level were discovered at IJin-ri site of Haenam, south coast of Korea. It would be very useful for calculating the rates of Eemian sea level rise and uplift of south coast of Korea. 62 cubic samples were collected at 6 cm intervals from the section (4.8-8.83m in elevation). Four sedimentary units, from Unit 1 to 4 in ascending order, are distinguished based on sedimentary textures and grain size distribution as follows: Unit 1 (sand, 4.8 m-5.32 m in elevation), Unit 2 (silty clay, 5.32 m-6.8 m in elevation), Unit 3 (gravelly sand, 6.8m-7.8m in elevation) and, Unit 4(sandy gravel, 7.8m-8.83m in elevation). The sediments which included rounded or semi-rounded gravels are thought to be transported from marine. Also, the assemblages of clay minerals from the sections are similar to those of Yellow Sea. It shows the possibility that the sediments originated from marine during high sea level

  1. Assessing the fidelity of surface currents from a coastal ocean model and HF radar using drifting buoys in the Middle Atlantic Bight

    NASA Astrophysics Data System (ADS)

    Kuang, Liang; Blumberg, Alan F.; Georgas, Nickitas

    2012-08-01

    The rapid expansion of urbanization along the world's coastal areas requires a more comprehensive and accurate understanding of the coastal ocean. Over the past several decades, numerical ocean circulation models have tried to provide such insight, based on our developing understanding of physical ocean processes. The systematic establishment of coastal ocean observation systems adopting cutting-edge technology, such as high frequency (HF) radar, satellite sensing, and gliders, has put such ocean model predictions to the test, by providing comprehensive observational datasets for the validation of numerical model forecasts. The New York Harbor Observing and Prediction System (NYHOPS) is a comprehensive system for understanding coastal ocean processes on the continental shelf waters of New York and New Jersey. To increase confidence in the system's ocean circulation predictions in that area, a detailed validation exercise was carried out using HF radar and Lagrangian drifter-derived surface currents from three drifters obtained between March and October 2010. During that period, the root mean square (RMS) differences of both the east-west and north-south currents between NYHOPS and HF radar were approximately 15 cm s-1. Harmonic analysis of NYHOPS and HF radar surface currents shows similar tidal ellipse parameters for the dominant M2 tide, with a mean difference of 2.4 cm s-1 in the semi-major axis and 1.4 cm s-1 in the semi-minor axis and 3° in orientation and 10° in phase. Surface currents derived independently from drifters along their trajectories showed that NYHOPS and HF radar yielded similarly accurate results. RMS errors when compared to currents derived along the trajectory of the three drifters were approximately 10 cm s-1. Overall, the analysis suggests that NYHOPS and HF radar had similar skill in estimating the currents over the continental shelf waters of the Middle Atlantic Bight during this time period. An ensemble-based set of particle tracking

  2. Currents, Water Budget and Turn-Over Time Within A Man-Made Coastal Mega-Structure: Palm Jumeirah, Southern Arabian Gulf, United Arab Emirates

    NASA Astrophysics Data System (ADS)

    Cavalcante, G.; Kjerfve, B.

    2009-05-01

    Large-scale land reclamation projects along the coastline of Dubai, United Arab Emirates (UAE), are set to expand from 45 km of natural shoreline to more than 1,500 km by 2010. The increasing scale of coastal development in Dubai has large-scale effects on water movement throughout the project area. Palm Jumeirah is the oldest, most well-developed of several man-made coastal mega-constructions in Dubai. This construction project started 6 years ago, has an overall surface area of 7.9 km2 and a footprint of 23 km2, and is connected to the coast via a 5-km long spine from the mainland to the crescent tip. We made time series observations of hydrographic properties and currents within the Palm Jumeirah Lagoon (PJL) during 29 days in April/May 2008 to examine the current flows, water budget, salt transport, and turn-over time. The currents and water flow within the PJL were quite variable, with stronger currents, greater material transports, lower water temperatures, and slightly lower salinities in areas close to the entrances where flushing is ample. Due to the shallow water depths, we found only weak vertical stratification during a tidal cycle. The lagoon system is comprised of 18 blind channels surrounded by a semi-circular open channel, which in turn is linked to the coastal waters by 4 gaps (one each on the East and West sides and two at the base of the development) in the rocky breakwater that surrounds the development. We found substantial differences in water discharge between the east and west gaps, with high discharge on average exiting the east gap and extremely low water discharge exiting the west gap. Our results indicate that the PJL is flushed unequally between the east and west sides with residence times of 1.2 and 42 days for the east and west sides of the development, respectively. Previous studies of water residence time using the DELFT3D hydrodynamics simulation modeling software did not capture this difference accurately, estimating residence

  3. Integration of bed characteristics, geochemical tracers, current measurements, and numerical modeling for assessing the provenance of beach sand in the San Francisco Bay coastal system

    USGS Publications Warehouse

    Barnard, Patrick L.; Foxgrover, Amy C.; Elias, Edwin P.L.; Erikson, Li H.; Hein, James R.; McGann, Mary; Mizell, Kira; Rosenbauer, Robert J.; Swarzenski, Peter W.; Takesue, Renee K.; Wong, Florence L.; Woodrow, Donald L.

    2013-01-01

    Over 150 million m3 of sand-sized sediment has disappeared from the central region of the San Francisco Bay Coastal System during the last half century. This enormous loss may reflect numerous anthropogenic influences, such as watershed damming, bay-fill development, aggregate mining, and dredging. The reduction in Bay sediment also appears to be linked to a reduction in sediment supply and recent widespread erosion of adjacent beaches, wetlands, and submarine environments. A unique, multi-faceted provenance study was performed to definitively establish the primary sources, sinks, and transport pathways of beach-sized sand in the region, thereby identifying the activities and processes that directly limit supply to the outer coast. This integrative program is based on comprehensive surficial sediment sampling of the San Francisco Bay Coastal System, including the seabed, Bay floor, area beaches, adjacent rock units, and major drainages. Analyses of sample morphometrics and biological composition (e.g., Foraminifera) were then integrated with a suite of tracers including 87Sr/86Sr and 143Nd/144Nd isotopes, rare earth elements, semi-quantitative X-ray diffraction mineralogy, and heavy minerals, and with process-based numerical modeling, in situ current measurements, and bedform asymmetry to robustly determine the provenance of beach-sized sand in the region.

  4. Integration of bed characteristics, geochemical tracers, current measurements, and numerical modeling for assessing the provenance of beach sand in the San Francisco Bay Coastal System

    USGS Publications Warehouse

    Barnard, Patrick L.; Foxgrover, Amy; Elias, Edwin P.L.; Erikson, Li H.; Hein, James; McGann, Mary; Mizell, Kira; Rosenbauer, Robert J.; Swarzenski, Peter W.; Takesue, Renee K.; Wong, Florence L.; Woodrow, Don

    2013-01-01

    Over 150 million m3 of sand-sized sediment has disappeared from the central region of the San Francisco Bay Coastal System during the last half century. This enormous loss may reflect numerous anthropogenic influences, such as watershed damming, bay-fill development, aggregate mining, and dredging. The reduction in Bay sediment also appears to be linked to a reduction in sediment supply and recent widespread erosion of adjacent beaches, wetlands, and submarine environments. A unique, multi-faceted provenance study was performed to definitively establish the primary sources, sinks, and transport pathways of beach-sized sand in the region, thereby identifying the activities and processes that directly limit supply to the outer coast. This integrative program is based on comprehensive surficial sediment sampling of the San Francisco Bay Coastal System, including the seabed, Bay floor, area beaches, adjacent rock units, and major drainages. Analyses of sample morphometrics and biological composition (e.g., Foraminifera) were then integrated with a suite of tracers including 87Sr/86Sr and 143Nd/144Nd isotopes, rare earth elements, semi-quantitative X-ray diffraction mineralogy, and heavy minerals, and with process-based numerical modeling, in situ current measurements, and bedform asymmetry to robustly determine the provenance of beach-sized sand in the region.

  5. Inorganic and organic contaminants in Alaskan shorebird eggs.

    PubMed

    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

  6. Standard Implications: Alaskans Reflect on a Movement To Change Teaching.

    ERIC Educational Resources Information Center

    Calkins, Annie, Ed.; Christian, Scott, Ed.

    In this anthology, rural Alaskan English teachers in the Bread Loaf Rural Teacher Network describe their experiences implementing new state education standards while continuing their commitment to learner-centered and place-based practice. The book presents narratives about teaching grounded in knowledge and understanding of students and…

  7. RESIDUAL MUTAGENICITY OF THE ALASKAN OIL SPILL ORGANICS

    EPA Science Inventory

    RESIDUAL MUTAGENICITY OF THE ALASKAN OIL SPILL ORGANICS. L.D.

    The Exxon Valdez, on March 24, 1989, spilled approximately eleven million gallons of Prudhoe Bay crude oil into the waters of Prince William Sound. Approximately 300 miles of
    contaminated beach are potential...

  8. Effects of the Oil Spill on Alaskan Education.

    ERIC Educational Resources Information Center

    Oldaker, Lawrence Lee

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

  9. Rural Alaskan Schools: Educational Specifications. Reprinted September, 1971.

    ERIC Educational Resources Information Center

    Alaska State Dept. of Education, Juneau. Office of Public Information and Publications.

    The educational specifications of facilities for rural Alaskan schools are given in this 1964 report. Alaska's 6 recognized geographic regions are briefly described with consideration to topography, climate, permafrost conditions, latitude position, and transportation difficulties which present problems in planning schools. Since the school design…

  10. Village Science: A Resource Handbook for Rural Alaskan Teachers.

    ERIC Educational Resources Information Center

    Dick, Alan

    A resource handbook for rural Alaskan teachers covers village science, to make basic science concepts relevant to the physical environment in villages. Material is intended for use as filler for weeks that come up short on science materials, to provide stimulation for students who cannot see the relevance of science in their lives, and to help…

  11. Definition of Alaskan Aviation Training Requirements. Final Report.

    ERIC Educational Resources Information Center

    Mitchell, M. K.; And Others

    Because of high accident rates and the unique conditions faced in Arctic flying, a project was conducted to develop a training program for airline pilots flying over Alaska. Data were gathered, through the critical incident method in conjunction with traditional job-analysis procedures, about how experienced Alaskan pilots learned to cope with the…

  12. A new tymovirus from a native Alaskan plant, Mertensia paniculata

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diseased plants growing at the interface of managed and natural ecosystems may provide reservoirs for spread of diverse plant viruses into domestic and native plants. Mertensia paniculata (Ait.) G. Don, family Boraginaceae, is a native Alaskan plant that is naturally distributed along roadsides, in ...

  13. Alaskan Manpower and the Petroleum-Related Workforce.

    ERIC Educational Resources Information Center

    Bland, Laurel L.

    This article, in two parts, presents information as a foundation for an integrated approach to utilization and employment of Alaskan manpower in the construction and maintenance of the trans-Alaska pipeline, and the continuing exploration and development of the petroleum fields. The four primary manpower sources for petroleum related employment in…

  14. Rural Alaskan High School Boys' and Girls' Attitudes toward Education.

    ERIC Educational Resources Information Center

    Chu, Lily; Culbertson, Jeanne

    Questionnaires were administered to 73 sophomore and senior high school students in 3 isolated rural Alaska towns (Adak, Unalaska, and Dillingham) to study the effects of socio-economic factors on rural Alaskan youth's educational aspirations and expectations. Because of a military-supported economy, Adak was a typical middle class American…

  15. STARS (Secondary Training for Alaskan Rural Students): Communications. Draft Copy.

    ERIC Educational Resources Information Center

    Griffin, Elaine; Opel, Kathleen

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

  16. SOME EFFECTS OF PETROLEUM ON NEARSHORE ALASKAN MARINE ORGANISMS

    EPA Science Inventory

    The overall objective of this project was to better understand the effects of chronic, low-level oil pollution on nearshore Alaskan marine organisms. The bivalve mollusc Macoma balthica accumulated hydrocarbons during 180 days of continuous exposure to Prudhoe Bay crude oil in fl...

  17. An improved understanding of the Alaska coastal current: The application of a bivalve growth-temperature model to reconstruct freshwater-influenced paleoenvironments

    USGS Publications Warehouse

    Hallmann, N.; Schone, B.R.; Irvine, G.V.; Burchell, M.; Cokelet, E.D.; Hilton, M.R.

    2011-01-01

    Shells of intertidal bivalve mollusks contain sub-seasonally to interannually resolved records of temperature and salinity variations in coastal settings. Such data are essential to understand changing land-sea interactions through time, specifically atmospheric (precipitation rate, glacial meltwater, river discharge) and oceanographic circulation patterns; however, independent temperature and salinity proxies are currently not available. We established a model for reconstructing daily water temperatures with an average standard error of ???1.3 ??C based on variations in the width of lunar daily growth increments of Saxidomus gigantea from southwestern Alaska, United States. Temperature explains 70% of the variability in shell growth. When used in conjunction with stable oxygen isotope data, this approach can also be used to identify changes in past seawater salinity. This study provides a better understanding of the hydrological changes related to the Alaska Coastal Current (ACC). In combination with ??18Oshell values, increment-derived temperatures were used to estimate salinity changes with an average error of 1.4 ?? 1.1 PSU. Our model was calibrated and tested with modern shells and then applied to archaeological specimens. As derived from the model, the time interval of 988-1447 cal yr BP was characterized by ???1-2 ??C colder and much drier (2-5 PSU) summers. During that time, the ACC was likely flowing much more slowly than at present. In contrast, between 599-1014 cal yr BP, the Aleutian low may have been stronger, which resulted in a 3 ??C temperature decrease during summers and 1-2 PSU fresher conditions than today; the ACC was probably flowing more quickly at that time. The shell growth-temperature model can be used to estimate seasonal to interannual salinity and temperature changes in freshwater-influenced environments through time. ?? 2011 SEPM (Society for Sedimentary Geology).

  18. Holocene coastal glaciation of Alaska

    NASA Astrophysics Data System (ADS)

    Calkin, Parker E.; Wiles, Gregory C.; Barclay, David J.

    2001-01-01

    Holocene fluctuations of the three cirque glaciers on the Seward Peninsula and five groups of tidewater- and land-terminating glaciers along the northernmost Gulf of Alaska, provide a proxy record of late Holocene climatic change. Furthermore, the movements of the coastal glaciers were relevant to late Holocene native American migration. The earliest expansion was recorded about 6850 yr BP by Hubbard Glacier at the head of Yakutat Bay in the Gulf of Alaska; however, its down-fjord advance to the bay mouth was delayed until ˜2700 BP. Similarly, expansions of the Icy Bay, Bering, and McCarty glaciers occurred near their present termini by ˜3600-3000 BP, compatible with marked cooling and precipitation increases suggested by the Alaskan pollen record. Decrease in glacier activity ˜2000 BP was succeeded by advances of Gulf coastal glaciers between 1500 and 1300 BP, correlative with early Medieval expansions across the Northern Hemisphere. A Medieval Optimum, encompassing at least a few centuries prior to AD 1200 is recognized by general retreat of land-terminating glaciers, but not of all tidewater glaciers. Little Ice Age advances of land-based glaciers, many dated with the precision of tree-ring cross-dating, were centered on the middle 13th or early 15th centuries, the middle 17th and the last half of the 19th century A.D. Strong synchrony of these events across coastal Alaska is evident.

  19. Seasonal Storminess in the North Pacific, Bering Sea, and Alaskan Regions

    NASA Astrophysics Data System (ADS)

    Shippee, N. J.; Atkinson, D. E.; Walsh, J. E.; Partain, J.; Gottschalck, J.; Marra, J.

    2012-12-01

    Annually, extra-tropical cyclones present a high impact natural hazard to the North Pacific, Bering Sea, and Alaskan regions. In these regions, extensive subsistence and commercial fishing, new oil and gas field development, tourism, growing interest in and exploitation of new commercial shipping potential, and increasing military and Coast Guard activity, all represent potential parties impacted by storms in these waters. It is of interest to many parties to begin developing capacity to provide some indication of storm activity at a monthly- to seasonal-outlook (30 to 90 days) timeframe. Using storm track data from NOAA's Climate Prediction Center for the North Pacific and Alaskan region, an experimental seasonal storminess outlook product, using eigen-based methods similar to the operational seasonal temperature and precipitation products currently produced at NOAA CPC, has been created and tested in hindcast mode using predicted states of ENSO, the Pacific Decadal Oscillation (PDO), the Pacific-North American Pattern (PNA), and the Arctic Oscillation (AO). A sample of the seasonal storminess outlook product will be shown along with a discussion of the utility of individual teleconnection patterns in the generation of the product.

  20. TRANSPORTATION ISSUES IN THE DELIVERY OF GTL PRODUCTS FROM ALASKAN NORTH SLOPE TO MARKET

    SciTech Connect

    Godwin Chukwu

    2004-01-01

    The Alaskan North Slope (ANS) is one of the largest hydrocarbon reserves in the United States 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. Because the domestic gas market in the continental United States is located thousands of miles from the ANS, transportation of the natural gas from the remote ANS to the market is the key issue in effective utilization of this valuable and abundant resource. The focus of this project is to study the operational challenges involved in transporting the gas in converted liquid (GTL) form through the existing Trans Alaska Pipeline System (TAPS). A three-year, comprehensive research program was undertaken by the Petroleum Development Laboratory, University of Alaska Fairbanks, under cooperative agreement No. DE-FC26-98FT40016 to study the feasibility of transporting GTL products through TAPS. Cold restart of TAPS following an extended winter shutdown and solids deposition in the pipeline were identified as the main transportation issues in moving GTL products through the pipeline. The scope of work in the current project (Cooperative Agreement No. DE-FC26-01NT41248) included preparation of fluid samples for the experiments to be conducted to augment the comprehensive research program.

  1. The wind-forced response on a buoyant coastal current: Observations of the western Gulf of Maine plume

    NASA Astrophysics Data System (ADS)

    Fong, D. A.; Geyer, W. R.; Signell, R. P.

    1997-08-01

    The freshwater plume in the western Gulf of Maine is being studied as part of an interdisciplinary investigation of the physical transport of a toxic alga. A field program was conducted in the springs of 1993 and 1994 to map the spatial and temporal patterns of salinity, currents and algal toxicity. The observations suggest that the plume's cross-shore structure varies markedly as a function of fluctuations in alongshore wind forcing. Consistent with Ekman drift dynamics, upwelling favorable winds spread the plume offshore, at times widening it to over 50 km in offshore extent, while downwelling favorable winds narrow the plume width to as little as 10 km. Using a simple slab model, we find qualitative agreement between the observed variations of plume width and those predicted by Ekman theory for short time scales of integration. Near surface current meters show significant correlations between cross-shore currents and alongshore wind stress, consistent with Ekman theory. Estimates of the terms in the alongshore momentum equation calculated from moored current meter arrays also indicate a dominant Ekman balance within the plume. A significant correlation between alongshore currents and winds suggests that interfacial drag may be important, although inclusion of a Raleigh drag term does not significantly improve the alongshore momentum balance.

  2. Coastal circulation and sediment dynamics in Maunalua Bay, Oahu, Hawaii, measurements of waves, currents, temperature, salinity, and turbidity; November 2008-February 2009

    USGS Publications Warehouse

    Storlazzi, Curt D.; Presto, M. Katherine; Logan, Joshua B.; Field, Michael E.

    2010-01-01

    High-resolution measurements of waves, currents, water levels, temperature, salinity and turbidity were made in Maunalua Bay, southern Oahu, Hawaii, during the 2008-2009 winter to better understand coastal circulation, water-column properties, and sediment dynamics during a range of conditions (trade winds, kona storms, relaxation of trade winds, and south swells). A series of bottom-mounted instrument packages were deployed in water depths of 20 m or less to collect long-term, high-resolution measurements of waves, currents, water levels, temperature, salinity, and turbidity. These data were supplemented with a series of profiles through the water column to characterize the vertical and spatial variability in water-column properties within the bay. These measurements support the ongoing process studies being done as part of the U.S. Geological Survey (USGS) Coastal and Marine Geology Program's Pacific Coral Reef Project; the ultimate goal of these studies is to better understand the transport mechanisms of sediment, larvae, pollutants, and other particles in coral reef settings. Project Objectives The objective of this study was to understand the temporal variations in currents, waves, tides, temperature, salinity and turbidity within a coral-lined embayment that receives periodic discharges of freshwater and sediment from multiple terrestrial sources in the Maunalua Bay. Instrument packages were deployed for a three-month period during the 2008-2009 winter and a series of vertical profiles were collected in November 2008, and again in February 2009, to characterize water-column properties within the bay. Measurements of flow and water-column properties in Maunalua Bay provided insight into the potential fate of terrestrial sediment, nutrient, or contaminant delivered to the marine environment and coral larval transport within the embayment. Such data are useful for providing baseline information for future watershed decisions and for establishing guidelines for

  3. Recent physical connections may explain weak genetic structure in western Alaskan chum salmon (Oncorhynchus keta) populations.

    PubMed

    Garvin, Michael R; Kondzela, Christine M; Martin, Patrick C; Finney, Bruce; Guyon, Jeffrey; Templin, William D; Decovich, Nick; Gilk-Baumer, Sara; Gharrett, Anthony J

    2013-07-01

    Low genetic divergence at neutral loci among populations is often the result of high levels of contemporary gene flow. Western Alaskan summer-run chum salmon (Oncorhynchus keta) populations demonstrate weak genetic structure, but invoking contemporary gene flow as the basis for the low divergence is problematic because salmon home to their natal streams and some of the populations are thousands of kilometers apart. We used genotypes from microsatellite and single nucleotide polymorphism loci to investigate alternative explanations for the current genetic structure of chum salmon populations from western Alaska. We also estimated current levels of gene flow among Kuskokwim River populations. Our results suggest that weak genetic structure is best explained by physical connections that occurred after the Holocene Thermal Maximum among the Yukon, Kuskokwim, and Nushagak drainages that allowed gene flow to occur among now distant populations. PMID:23919176

  4. Recent physical connections may explain weak genetic structure in western Alaskan chum salmon (Oncorhynchus keta) populations

    PubMed Central

    Garvin, Michael R; Kondzela, Christine M; Martin, Patrick C; Finney, Bruce; Guyon, Jeffrey; Templin, William D; DeCovich, Nick; Gilk-Baumer, Sara; Gharrett, Anthony J

    2013-01-01

    Low genetic divergence at neutral loci among populations is often the result of high levels of contemporary gene flow. Western Alaskan summer-run chum salmon (Oncorhynchus keta) populations demonstrate weak genetic structure, but invoking contemporary gene flow as the basis for the low divergence is problematic because salmon home to their natal streams and some of the populations are thousands of kilometers apart. We used genotypes from microsatellite and single nucleotide polymorphism loci to investigate alternative explanations for the current genetic structure of chum salmon populations from western Alaska. We also estimated current levels of gene flow among Kuskokwim River populations. Our results suggest that weak genetic structure is best explained by physical connections that occurred after the Holocene Thermal Maximum among the Yukon, Kuskokwim, and Nushagak drainages that allowed gene flow to occur among now distant populations. PMID:23919176

  5. Hereditary encephalomyelopathy and polyneuropathy in an Alaskan husky.

    PubMed

    Wakshlag, J J; de Lahunta, A

    2009-12-01

    An Alaskan husky puppy was examined for a neurologic disease which began at six weeks of age with generalised paresis that progressed resulting in recumbency by 18 weeks. Thoracic limbs primarily exhibited lower motor neuron signs that included distal muscle atrophy and persistent elbow and carpal flexion that resisted manual extension. Pelvic limb signs primarily exhibited upper motor neuron and general proprioceptive deficits, but also included lower motor neuron signs. Abnormal vocalisation suggested a laryngeal paresis. Histopathologic lesions included a diffuse axonopathy and secondary demyelination in the nerves of the limbs and larynx and a similar bilaterally symmetrical degeneration in the spinal cord white matter suggestive of a dying back axonopathy. In addition, a degenerative process was present in nuclei in the brain stem and cerebellum. Recognition of this disease through clinical and pathologic examination in other related Alaskan Huskies suggested an autosomal recessive inherited disorder. PMID:19954445

  6. Seasonal variation of a coastal jet in the Long Island Sound outflow region based on HF radar and Doppler current observations

    NASA Astrophysics Data System (ADS)

    Ullman, D. S.; Codiga, D. L.

    2004-07-01

    Surface current (HF radar) and velocity profile observations, obtained as part of the Front-Resolving Observational Network with Telemetry (FRONT) project over an approximately 2-year period, are used to describe the seasonal variability of a coastal jet in the Long Island Sound outflow region. The jet is observed in an area of the continental shelf where surface thermal fronts are frequently detected during both summer and winter. The current jet is coincident with a band of high summer frontal probability, and apparently arises from the interaction between Long Island Sound outflow and larger-scale alongshore currents on the shelf. The jet reaches peak strength in summer (transport of ˜0.07 Sv) and is weak or non-existent in winter. Flow is strongest near the surface and weakens with depth, with only moderate seasonal variations in the vertical shear. The relatively long data set of currents combined with historical hydrographic measurements and buoy wind observations is analyzed to examine the seasonal variability of the terms in the depth-averaged momentum balance. The depth-averaged pressure gradient is partitioned into a steric component, evaluated from the hydrography, and a non-steric component that is estimated as the residual of the computed terms in the momentum equation. The depth-averaged momentum balance is found to be approximately geostrophic in the across-shore direction. The seasonal variability in the jet arises due to the shifting balance between buoyancy-driven flow that is always downshelf but intensifies somewhat in summer and wind-driven flow which dominates in winter when wind stress becomes strongly upwelling favorable.

  7. Revegetation of Alaskan coal mine spoils. Progress report

    SciTech Connect

    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.

  8. A practical method of determining water current velocities and diffusion coefficients in coastal waters by remote sensing techniques

    NASA Technical Reports Server (NTRS)

    James, W. P.

    1971-01-01

    A simplified procedure is presented for determining water current velocities and diffusion coefficients. Dye drops which form dye patches in the receiving water are made from an aircraft. The changes in position and size of the patches are recorded from two flights over the area. The simplified data processing procedure requires only that the ground coordinates about the dye patches be determined at the time of each flight. With an automatic recording coordinatograph for measuring coordinates and a computer for processing the data, this technique provides a practical method of determining circulation patterns and mixing characteristics of large aquatic systems. This information is useful in assessing the environmental impact of waste water discharges and for industrial plant siting.

  9. An introduction to coastal geomorphology

    SciTech Connect

    Pethick, J.S.

    1984-01-01

    This book is an introduction to wave and tidally dominated coastal forms, including beaches, cliffs, dunes, estuaries, mudflats and marshlands. The book emphasises the physical mechanisms by which this variety of landforms is produced and maintained. It introduces the energy outputs - waves, currents, tides - into the coastal 'machine', examines the way in which this energy is converted into water and sediment movement, and leads to an account of coastal landform development.

  10. Coastal circulation and sediment dynamics in Pelekane and Kawaihae Bays, Hawaii--measurements of waves, currents, temperature, salinity, turbidity, and geochronology: November 2010--March 2011

    USGS Publications Warehouse

    Storlazzi, Curt D.; Field, Michael E.; Presto, M. Katherine; Swarzenski, Peter W.; Logan, Joshua B.; Reiss, Thomas E.; Elfers, Timothy C.; Cochran, Susan A.; Torresan, Michael E.; Chezar, Hank

    2012-01-01

    Coral reef communities on the Island of Hawaii have been heavily affected by the construction of Kawaihae Harbor in the 1950s and by subsequent changes in land use in the adjacent watershed. Sedimentation and other forms of land-based pollution have led to declines in water quality and coral reef health over the past two decades (Tissot, 1998). Erosion mitigation efforts are underway on land, and there is a need to evaluate the impact of these actions on the adjacent coastal ecosystem. The Kohala Center and Kohala Watershed Partnership was awarded $2.69 million from the National Oceanographic and Atmospheric Administration’s (NOAA) Restoration Center as part of the American Recovery and Reinvestment Act of 2009 to stabilize soil and improve land-use practices in the Pelekane Bay watershed. The grant allowed the Kohala Watershed Partnership to implement various upland watershed management activities to reduce land-based sources of pollution into Pelekane Bay. However, a number of questions must be answered in order to: (1) evaluate the effectiveness of the terrestrial watershed remediation efforts; (2) understand the potential of the local marine ecosystem to recover; and (3) understand the potential threat that existing mud deposits in the bay pose to adjacent, relatively pristine coral reef ecosystems. The goal of this experiment was to help address these questions and establish a framework to evaluate the success of the Kohala Watershed Partnership restoration efforts. This research program will also provide resource managers with information relevant to other watershed restoration efforts currently being planned in neighboring watersheds. This project involved an interdisciplinary team of coral reef biologists from the University of Hawaii Coral Reef Assessment and Monitoring Program, who focused on the impact of sedimentation on the biota of Pelekane Bay, and a team of geologists and oceanographers from the U.S. Geological Survey (USGS), who focused on the

  11. 40 CFR 408.60 - Applicability; description of the non-remote Alaskan whole crab and crab section processing...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-remote Alaskan whole crab and crab section processing subcategory. 408.60 Section 408.60 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Whole Crab and Crab Section Processing Subcategory § 408.60 Applicability; description of the non-remote Alaskan whole crab and crab...

  12. 40 CFR 408.70 - Applicability; description of the remote Alaskan whole crab and crab section processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... remote Alaskan whole crab and crab section processing subcategory. 408.70 Section 408.70 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Remote Alaskan Whole Crab and Crab Section Processing Subcategory § 408.70 Applicability; description of the remote Alaskan whole crab and crab section...

  13. 40 CFR 408.60 - Applicability; description of the non-remote Alaskan whole crab and crab section processing...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-remote Alaskan whole crab and crab section processing subcategory. 408.60 Section 408.60 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Whole Crab and Crab Section Processing Subcategory § 408.60 Applicability; description of the non-remote Alaskan whole crab and crab...

  14. 40 CFR 408.70 - Applicability; description of the remote Alaskan whole crab and crab section processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... remote Alaskan whole crab and crab section processing subcategory. 408.70 Section 408.70 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Remote Alaskan Whole Crab and Crab Section Processing Subcategory § 408.70 Applicability; description of the remote Alaskan whole crab and crab section...

  15. 40 CFR 408.70 - Applicability; description of the remote Alaskan whole crab and crab section processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... remote Alaskan whole crab and crab section processing subcategory. 408.70 Section 408.70 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Remote Alaskan Whole Crab and Crab Section Processing Subcategory § 408.70 Applicability; description of the remote Alaskan whole crab and crab section...

  16. 40 CFR 408.70 - Applicability; description of the remote Alaskan whole crab and crab section processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... remote Alaskan whole crab and crab section processing subcategory. 408.70 Section 408.70 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Remote Alaskan Whole Crab and Crab Section Processing Subcategory § 408.70 Applicability; description of the remote Alaskan whole crab and crab section...

  17. 40 CFR 408.60 - Applicability; description of the non-remote Alaskan whole crab and crab section processing...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-remote Alaskan whole crab and crab section processing subcategory. 408.60 Section 408.60 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Whole Crab and Crab Section Processing Subcategory § 408.60 Applicability; description of the non-remote Alaskan whole crab and crab...

  18. 40 CFR 408.70 - Applicability; description of the remote Alaskan whole crab and crab section processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... remote Alaskan whole crab and crab section processing subcategory. 408.70 Section 408.70 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Remote Alaskan Whole Crab and Crab Section Processing Subcategory § 408.70 Applicability; description of the remote Alaskan whole crab and crab section...

  19. 40 CFR 408.60 - Applicability; description of the non-remote Alaskan whole crab and crab section processing...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-remote Alaskan whole crab and crab section processing subcategory. 408.60 Section 408.60 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Whole Crab and Crab Section Processing Subcategory § 408.60 Applicability; description of the non-remote Alaskan whole crab and crab...

  20. 40 CFR 408.60 - Applicability; description of the non-remote Alaskan whole crab and crab section processing...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-remote Alaskan whole crab and crab section processing subcategory. 408.60 Section 408.60 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Whole Crab and Crab Section Processing Subcategory § 408.60 Applicability; description of the non-remote Alaskan whole crab and crab...

  1. 40 CFR 408.40 - Applicability; description of the non-remote Alaskan crab meat processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-remote Alaskan crab meat processing subcategory. 408.40 Section 408.40 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Crab Meat Processing Subcategory § 408.40 Applicability; description of the non-remote Alaskan crab meat processing subcategory. The provisions of this subpart...

  2. 40 CFR 408.40 - Applicability; description of the non-remote Alaskan crab meat processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-remote Alaskan crab meat processing subcategory. 408.40 Section 408.40 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Crab Meat Processing Subcategory § 408.40 Applicability; description of the non-remote Alaskan crab meat processing subcategory. The provisions of this subpart...

  3. 40 CFR 408.40 - Applicability; description of the non-remote Alaskan crab meat processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-remote Alaskan crab meat processing subcategory. 408.40 Section 408.40 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Crab Meat Processing Subcategory § 408.40 Applicability; description of the non-remote Alaskan crab meat processing subcategory. The provisions of this subpart...

  4. 40 CFR 408.40 - Applicability; description of the non-remote Alaskan crab meat processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-remote Alaskan crab meat processing subcategory. 408.40 Section 408.40 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Crab Meat Processing Subcategory § 408.40 Applicability; description of the non-remote Alaskan crab meat processing subcategory. The provisions of this subpart...

  5. 40 CFR 408.40 - Applicability; description of the non-remote Alaskan crab meat processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-remote Alaskan crab meat processing subcategory. 408.40 Section 408.40 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Crab Meat Processing Subcategory § 408.40 Applicability; description of the non-remote Alaskan crab meat processing subcategory. The provisions of this subpart...

  6. 25 CFR 243.11 - Are transfers of Alaskan reindeer that occurred before issuance of this part valid?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Are transfers of Alaskan reindeer that occurred before... INTERIOR FISH AND WILDLIFE REINDEER IN ALASKA § 243.11 Are transfers of Alaskan reindeer that occurred before issuance of this part valid? All transfers of live Alaskan reindeer or reindeer products that...

  7. 25 CFR 243.11 - Are transfers of Alaskan reindeer that occurred before issuance of this part valid?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Are transfers of Alaskan reindeer that occurred before... INTERIOR FISH AND WILDLIFE REINDEER IN ALASKA § 243.11 Are transfers of Alaskan reindeer that occurred before issuance of this part valid? All transfers of live Alaskan reindeer or reindeer products that...

  8. 25 CFR 243.11 - Are transfers of Alaskan reindeer that occurred before issuance of this part valid?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Are transfers of Alaskan reindeer that occurred before... INTERIOR FISH AND WILDLIFE REINDEER IN ALASKA § 243.11 Are transfers of Alaskan reindeer that occurred before issuance of this part valid? All transfers of live Alaskan reindeer or reindeer products that...

  9. 25 CFR 243.11 - Are transfers of Alaskan reindeer that occurred before issuance of this part valid?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Are transfers of Alaskan reindeer that occurred before... INTERIOR FISH AND WILDLIFE REINDEER IN ALASKA § 243.11 Are transfers of Alaskan reindeer that occurred before issuance of this part valid? All transfers of live Alaskan reindeer or reindeer products that...

  10. 25 CFR 243.11 - Are transfers of Alaskan reindeer that occurred before issuance of this part valid?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Are transfers of Alaskan reindeer that occurred before... INTERIOR FISH AND WILDLIFE REINDEER IN ALASKA § 243.11 Are transfers of Alaskan reindeer that occurred before issuance of this part valid? All transfers of live Alaskan reindeer or reindeer products that...

  11. 40 CFR 408.220 - Applicability; description of the non-Alaskan mechanized bottom fish processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-Alaskan mechanized bottom fish processing subcategory. 408.220 Section 408.220 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Mechanized Bottom Fish Processing Subcategory § 408.220 Applicability; description of the non-Alaskan mechanized bottom fish processing subcategory. The provisions...

  12. 40 CFR 408.220 - Applicability; description of the non-Alaskan mechanized bottom fish processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-Alaskan mechanized bottom fish processing subcategory. 408.220 Section 408.220 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Mechanized Bottom Fish Processing Subcategory § 408.220 Applicability; description of the non-Alaskan mechanized bottom fish processing subcategory. The provisions...

  13. 40 CFR 408.210 - Applicability; description of the non-Alaskan conventional bottom fish processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-Alaskan conventional bottom fish processing subcategory. 408.210 Section 408.210 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Conventional Bottom Fish Processing Subcategory § 408.210 Applicability; description of the non-Alaskan conventional bottom fish processing subcategory. The provisions...

  14. 40 CFR 408.210 - Applicability; description of the non-Alaskan conventional bottom fish processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-Alaskan conventional bottom fish processing subcategory. 408.210 Section 408.210 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Conventional Bottom Fish Processing Subcategory § 408.210 Applicability; description of the non-Alaskan conventional bottom fish processing subcategory. The provisions...

  15. 40 CFR 408.210 - Applicability; description of the non-Alaskan conventional bottom fish processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-Alaskan conventional bottom fish processing subcategory. 408.210 Section 408.210 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Conventional Bottom Fish Processing Subcategory § 408.210 Applicability; description of the non-Alaskan conventional bottom fish processing subcategory. The provisions...

  16. 40 CFR 408.220 - Applicability; description of the non-Alaskan mechanized bottom fish processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-Alaskan mechanized bottom fish processing subcategory. 408.220 Section 408.220 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Mechanized Bottom Fish Processing Subcategory § 408.220 Applicability; description of the non-Alaskan mechanized bottom fish processing subcategory. The provisions...

  17. 40 CFR 408.220 - Applicability; description of the non-Alaskan mechanized bottom fish processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-Alaskan mechanized bottom fish processing subcategory. 408.220 Section 408.220 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Mechanized Bottom Fish Processing Subcategory § 408.220 Applicability; description of the non-Alaskan mechanized bottom fish processing subcategory. The provisions...

  18. 40 CFR 408.210 - Applicability; description of the non-Alaskan conventional bottom fish processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-Alaskan conventional bottom fish processing subcategory. 408.210 Section 408.210 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Conventional Bottom Fish Processing Subcategory § 408.210 Applicability; description of the non-Alaskan conventional bottom fish processing subcategory. The provisions...

  19. 40 CFR 408.210 - Applicability; description of the non-Alaskan conventional bottom fish processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-Alaskan conventional bottom fish processing subcategory. 408.210 Section 408.210 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Conventional Bottom Fish Processing Subcategory § 408.210 Applicability; description of the non-Alaskan conventional bottom fish processing subcategory. The provisions...

  20. 40 CFR 408.220 - Applicability; description of the non-Alaskan mechanized bottom fish processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-Alaskan mechanized bottom fish processing subcategory. 408.220 Section 408.220 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Mechanized Bottom Fish Processing Subcategory § 408.220 Applicability; description of the non-Alaskan mechanized bottom fish processing subcategory. The provisions...

  1. An Authentic Voice in the Technocratic Wilderness: Alaskan Natives and the "Tundra Times."

    ERIC Educational Resources Information Center

    Daley, Patrick; James, Beverly

    1986-01-01

    Examines a pair of critical challenges to the cultural integrity of Alaskan Natives around 1960 as pivotal episodes in the process of native resistance to U. S. dominance. Historically evaluates the fragility of native culture in terms of the political, scientific, and economic interests expressed in the mainstream Alaskan press, particularly the…

  2. Sled Dogs, Musher Math, and More: Theme Teaching and the Alaskan Iditarod.

    ERIC Educational Resources Information Center

    Park-Seldomridge, Anne

    1995-01-01

    A teacher of upper elementary deaf students describes a multidisciplinary study unit focused on the Alaskan dogsled race, the Iditarod. Activities included studying Alaskan geography and history, following specific racers (mushers) through daily updates faxed from Alaska, writing letters to mushers, calculating math facts related to the race,…

  3. 25 CFR 243.9 - Who may inherit live Alaskan reindeer and by what means?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... provisions of 43 CFR part 4, subpart D. During the pendency of such a proceeding, the authority to assume control over the affected Alaskan reindeer pursuant to 43 CFR 4.270 may be exercised by the Alaska... 25 Indians 1 2014-04-01 2014-04-01 false Who may inherit live Alaskan reindeer and by what...

  4. 25 CFR 243.4 - Who can own or possess Alaskan reindeer?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Who can own or possess Alaskan reindeer? 243.4 Section 243.4 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE REINDEER IN ALASKA § 243.4 Who can own or possess Alaskan reindeer? (a) Only Alaska Natives, organizations of...

  5. 25 CFR 243.9 - Who may inherit live Alaskan reindeer and by what means?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... provisions of 43 CFR part 4, subpart D. During the pendency of such a proceeding, the authority to assume control over the affected Alaskan reindeer pursuant to 43 CFR 4.270 may be exercised by the Alaska... 25 Indians 1 2010-04-01 2010-04-01 false Who may inherit live Alaskan reindeer and by what...

  6. 25 CFR 243.9 - Who may inherit live Alaskan reindeer and by what means?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... provisions of 43 CFR part 4, subpart D. During the pendency of such a proceeding, the authority to assume control over the affected Alaskan reindeer pursuant to 43 CFR 4.270 may be exercised by the Alaska... 25 Indians 1 2012-04-01 2011-04-01 true Who may inherit live Alaskan reindeer and by what...

  7. 25 CFR 243.4 - Who can own or possess Alaskan reindeer?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Who can own or possess Alaskan reindeer? 243.4 Section 243.4 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE REINDEER IN ALASKA § 243.4 Who can own or possess Alaskan reindeer? (a) Only Alaska Natives, organizations of...

  8. 25 CFR 243.4 - Who can own or possess Alaskan reindeer?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Who can own or possess Alaskan reindeer? 243.4 Section 243.4 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE REINDEER IN ALASKA § 243.4 Who can own or possess Alaskan reindeer? (a) Only Alaska Natives, organizations of...

  9. 25 CFR 243.9 - Who may inherit live Alaskan reindeer and by what means?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... provisions of 43 CFR part 4, subpart D. During the pendency of such a proceeding, the authority to assume control over the affected Alaskan reindeer pursuant to 43 CFR 4.270 may be exercised by the Alaska... 25 Indians 1 2011-04-01 2011-04-01 false Who may inherit live Alaskan reindeer and by what...

  10. 25 CFR 243.4 - Who can own or possess Alaskan reindeer?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Who can own or possess Alaskan reindeer? 243.4 Section 243.4 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE REINDEER IN ALASKA § 243.4 Who can own or possess Alaskan reindeer? (a) Only Alaska Natives, organizations of...

  11. 25 CFR 243.9 - Who may inherit live Alaskan reindeer and by what means?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... provisions of 43 CFR part 4, subpart D. During the pendency of such a proceeding, the authority to assume control over the affected Alaskan reindeer pursuant to 43 CFR 4.270 may be exercised by the Alaska... 25 Indians 1 2013-04-01 2013-04-01 false Who may inherit live Alaskan reindeer and by what...

  12. 25 CFR 243.4 - Who can own or possess Alaskan reindeer?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Who can own or possess Alaskan reindeer? 243.4 Section 243.4 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE REINDEER IN ALASKA § 243.4 Who can own or possess Alaskan reindeer? (a) Only Alaska Natives, organizations of...

  13. A NATIONAL COASTAL ASSESSMENT OF COASTAL SEDIMENT CONDITION

    EPA Science Inventory

    One element of the Environmental Monitoring and Assessment Program's National Coastal Assessment is to estimate the current status, extent, changes and trends in the condition of the Nation's coastal sediments on a national basis. Based on NCA monitoring activities from 1999-2001...

  14. California coastal processes study

    NASA Technical Reports Server (NTRS)

    Pirie, D. M.; Steller, D. D.

    1974-01-01

    Preliminary findings are presented and applications derived from ERTS-1 satellite imagery of the nearshore coastal processes of the California coast. The objectives were to analyze nearshore currents, sediment transport, and estuarine and river discharges along the California coast through the use of synoptic and repetitive imagery from ERTS as well as aircraft underflights and surface data. The major conclusions are: (1) Distinct seasonal patterns for sediment transport as a function of the oceanic current systems and coastal morphology have been identified. (2) Large scale sediment plumes from intermittent streams and rivers extend offshore to previously unanticipated ranges. (3) Computer generated contouring of radiance levels from computer-compatible tapes result in charts that can be used for determination of surface and nearsurface suspended sediment distribution. (4) Flying spot scanner enhancements result in details of nearshore features. (5) Data is providing significant information for coastal planning and construction projects.

  15. (Alaskan commodities irradiation project: An options analysis study)

    SciTech Connect

    Zarling, J.P.; Swanson, R.B.; Logan, R.R.; Das, D.K.; Lewis, C.E.; Workman, W.G.; Tumeo, M.A.; Hok, C.I.; Birklind, C.A.; Bennett, F.L. . Inst. of Northern Engineering)

    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.

  16. Dietetics training for American Indians and Alaskan natives.

    PubMed

    Jackson, M Y; Cornelius, M S; Johnson, C I

    1983-07-01

    The response to training has been enthusiastic. Even in these times of limited funds, applications to attend training exceed the available space. From the first class in October 1968 through September 1982, nearly 1,300 Indian and Alaskan native hospital food service employees and employees representing tribal programs throughout the country have received training from the courses and workshops provided by the Nutrition and Dietetics Training Program. With the increasing involvement of Native Americans in their own health care programs, the need for training in foods and nutrition will continue. PMID:6863784

  17. A first step in constructing a long multi-lake paleoseismic record in Southern Alaska for revealing the recurrence rate of megathrust earthquakes along the Alaskan-Aleutian subduction zone

    NASA Astrophysics Data System (ADS)

    Praet, Nore; Moernaut, Jasper; Van Daele, Maarten; Kempf, Philipp; Haeussler, Peter; Strupler, Michael; De Batist, Marc

    2014-05-01

    On March 27, 1964, the "Good Friday" Earthquake ruptured an 800 km-long segment of the Alaskan-Aleutian megathrust, representing the largest measured earthquake in North America (Mw 9.2). Recurrence rates of such megathrust earthquakes are typically in the order of hundreds of years. The development of a reliable assessment of seismic hazards evidently requires statistically much more robust earthquake recurrence data. For this, high-quality paleoseismological records are necessary, which are able to extend the historical evidence much further back in time. The current knowledge of the paleoseismicity along the megathrust segment around Prince William Sound is inferred from records of abrupt changes in coastal elevation. Lake sediments can also produce excellent paleoseismological records. Seismically induced subaquatic landslides generate distinct resedimentation deposits that are interbedded in between the background sediments. During a reconnaissance survey in 2012, we collected short cores and high-resolution seismic data in several glacial lakes in Southern Alaska. The short gravity cores reveal a clear sedimentary imprint of the 1964 Earthquake in different sub-basins of the investigated lakes, and the seismic profiles show the presence of older mass-wasting deposits with similar large volumes. Multiple landslide deposits and associated turbidites at several stratigraphic levels imply that these deposits were also triggered by strong earthquake shaking. The length (i.e. entire Holocene) and high-resolution chronology (i.e. Pb/Cs data reveal that the core laminations represent varves) of the lacustrine record will allow to generate a unique, high-quality dataset of megathrust earthquake recurrences along the Prince William Sound segment of the Alaskan-Aleutian subduction zone. In winter of 2014, long cores (ca. 15 meters) will be taken at key locations in Skilak Lake, Eklutna Lake and possibly Kenai Lake. Analyzing and dating these sediment cores will make it

  18. Automated Mapping of Rapid Arctic Ocean Coastal Change Over Large Spans of Time and Geography

    NASA Astrophysics Data System (ADS)

    Hulslander, D.

    2012-12-01

    While climate change is global in scope, its impacts vary greatly from region to region. The dynamic Arctic Ocean coastline often shows greater sensitivity to climate change and more obvious impacts. Current longer ice-free conditions, rising sea level, thawing permafrost, and melting of larger ice bodies combine to produce extremely rapid coastal change and erosion. Anderson et al. (2009; Geology News) have measured erosion rates at sites along the Alaskan Arctic Ocean coast of 15 m per year and greater. Completely understanding coastal change in the Arctic requires mapping both current erosional regimes as well as changes in erosional rates over several decades. Studying coastal change and trends in the Arctic, however, presents several significant difficulties. The study area is enormous, with over 45,000 km of coastline; it is also one of the most remote, inaccessible, and hostile environments on Earth. Moreover, the region has little to no historical data from which to start. Thus, any study of the area must be able to construct its own baseline. Remote sensing offers the best solution given these difficulties. Spaceborne platforms allow for regular global coverage at temporal and spatial scales sufficient for mapping coastal erosion and deposition. The Landsat family of instruments (MSS, TM, and ETM) has data available as frequently as every 16 days and starting as early as 1972. The data are freely available from the USGS through earthexplorer.usgs.gov and are well calibrated both geometrically and spectrally, eliminating expensive pre-processing steps and making them analysis-ready. Finally, because manual coastline delineation of the quantity of data involved would be prohibitive in both budget and labor, an automated processing chain must be used. ENVI Feature Extraction can provide results in line with those generated by expert analysts (Hulslander, et al., 2008; GEOBIA 2008 Proceedings). Previous studies near Drew Point, Alaska have shown that feature

  19. Quantifying the historic and future distribution of fire in Alaskan tundra ecosystems

    NASA Astrophysics Data System (ADS)

    Young, A. M.; Higuera, P. E.; Duffy, P. A.

    2012-12-01

    variable in the GBM, and partial dependence plots revealed a strong non-linear relationship between the probability of fire and MeanMaxTemp, with a distinct temperature threshold of approximately 12.0 oC. Climate projections in Alaskan tundra (2021-2050) from the five GCMs was on average 2.1 oC warmer (SD = 0.3 oC) than the 1971-2000 mean. During the 1971-2000 period, 62% of tundra existed above the 12.0 oC threshold. In contrast, four of the five GCMs predicted more tundra area will exist above this same temperature threshold during the 2021-2050 period (mean=77%, min=48%, max=93%), with large increases occurring on the North Slope. Ongoing work includes applying this GBM to future climate conditions to provide quantitative estimates of future tundra burning. Our results suggest that the ecological space that currently supports tundra burning will become more common during the next century. A more flammable tundra landscape could contribute to increased land surface temperatures through feedbacks between fire, increased carbon flux from the soil to atmosphere, and decreased albedo through vegetation succession. Given the rapid environmental changes projected for the Arctic throughout the next century, it is imperative that we understand when and where fire regimes are changing, not only across Alaskan tundra but across the global tundra biome as well.

  20. Coastal Circulation and Sediment Dynamics in War-in-the-Pacific National Historical Park, Guam; measurements of waves, currents, temperature, salinity, and turbidity, June 2007-January 2008

    USGS Publications Warehouse

    Storlazzi, Curt D.; Presto, M. Katherine; Logan, Joshua B.

    2009-01-01

    Flow in and around coral reefs affects a number of physical, chemical and biologic processes that influence the health and sustainability of coral reef ecosystems. These range from the residence time of sediment and contaminants to nutrient uptake and larval retention and dispersal. As currents approach a coast they diverge to flow around reef structures, causing high horizontal and vertical shear. This can result in either the rapid advection of material in localized jets, or the retention of material in eddies that form in the lee of bathymetric features. The high complexity and diversity both within and between reefs, in conjunction with past technical restrictions, has limited our understanding of the nature of flow and the resulting flux of physical, chemical, and biologic material in these fragile ecosystems. Sediment, nutrients, and other pollutants from a variety of land-based activities adversely impact many coral reef ecosystems in the U.S. and around the world. These pollutants are transported in surface water runoff, groundwater seepage, and atmospheric fallout into coastal waters, and there is compelling evidence that the sources have increased globally as a result of human-induced changes to watersheds. In Guam, and elsewhere on U.S. high islands in the Pacific and Caribbean, significant changes in the drainage basins due to agriculture, feral grazing, fires, and urbanization have in turn altered the character and volume of land-based pollution released to coral reefs. Terrigenous sediment run-off (and the associated nutrients and contaminants often absorbed to it) and deposition on coral reefs are recognized to potentially have significant impact on coral health by blocking light and inhibiting photosynthesis, directly smothering and abrading coral, and triggering increases in macro algae. Studies that combine information on watershed, surface water- and groundwater-flow, transport and fate of sediment and other pollutants in the reef environment

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

    NASA Astrophysics Data System (ADS)

    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.

  2. Gonorrhea among drug users: an Alaskan versus a national sample.

    PubMed

    Paschane, D M; Fisher, D G; Cagle, H H; Fenaughty, A M

    1998-05-01

    The study described here investigates the replicability of gender-specific risk profiles for gonorrhea based on an Alaskan sample compared to a U.S. national sample of drug users at risk for HIV infection. The Alaska sample (interviewed at a field station in Anchorage, Alaska; N=1,049) and the national sample (interviewed at 18 sites other than Alaska; N=17,619) consisted of cocaine smokers and injection drug users not in drug treatment. A history of gonorrhea infection was self-reported and coded as ever or never. The Anchorage and national risk profile for men included the following factors: (a) history of intranasal or parenteral cocaine use, (b) being black versus nonblack, (c) being older, (d) income from illegal activity, and (e) history of amphetamine use. The Anchorage and national risk profiles for women included the following factors: (a) trading sex for money, (b) being Native American versus non-Native American, and (c) trading sex for drugs. The Anchorage model for women included perceived homelessness as a factor, but it was not retained in the national model. The extent of the replicability of these models illustrates the generalizability of Alaskan findings to other U.S. drug-using populations. The authors also discuss the implications of these findings for disease prevention. PMID:9643466

  3. Analysis of Alaskan burn severity patterns using remotely sensed data

    USGS Publications Warehouse

    Duffy, P.A.; Epting, J.; Graham, J.M.; Rupp, T.S.; McGuire, A.D.

    2007-01-01

    Wildland fire is the dominant large-scale disturbance mechanism in the Alaskan boreal forest, and it strongly influences forest structure and function. In this research, patterns of burn severity in the Alaskan boreal forest are characterised using 24 fires. First, the relationship between burn severity and area burned is quantified using a linear regression. Second, the spatial correlation of burn severity as a function of topography is modelled using a variogram analysis. Finally, the relationship between vegetation type and spatial patterns of burn severity is quantified using linear models where variograms account for spatial correlation. These results show that: 1) average burn severity increases with the natural logarithm of the area of the wildfire, 2) burn severity is more variable in topographically complex landscapes than in flat landscapes, and 3) there is a significant relationship between burn severity and vegetation type in flat landscapes but not in topographically complex landscapes. These results strengthen the argument that differential flammability of vegetation exists in some boreal landscapes of Alaska. Additionally, these results suggest that through feedbacks between vegetation and burn severity, the distribution of forest vegetation through time is likely more stable in flat terrain than it is in areas with more complex topography. ?? IAWF 2007.

  4. Reanalysis of the USGS Alaskan benchmark glacier dataset

    NASA Astrophysics Data System (ADS)

    van Beusekom, A. E.; O'Neel, S.; March, R. S.; Sass, L. C.

    2010-12-01

    Resolving the relationship between glacier surface-forcing (climate) and glacier geometry changes is accomplished through mass-balance estimates which can be made with remote sensing methods or field-based observations. The small scale of Alaskan glaciers has prevented remote sensing methods until recently, and field data are essential for validating new techniques. Field data provide the only long duration record that can be studied with respect to climate. The United States Geological Survey has maintained a 44-year mass-balance program at Alaska’s Gulkana Glacier and Wolverine Glacier. We have reanalyzed the Alaskan benchmark glaciers mass balance time series so that all data are treated similarly and systematically. Both glaciers are undergoing sustained mass loss with an increasing rate in recent years. However, the magnitude of the calculated loss depends on the number and location of the data collection sites. We explore the sensitivity of the glacier-wide balance estimates to the method of integration used on the necessarily point data. The robustness of the balance is strengthened with use of independent photogrammetric measurements.

  5. Integrated carbon budget models for the Everglades terrestrial-coastal-oceanic gradient: Current status and needs for inter-site comparisons

    USGS Publications Warehouse

    Troxler, Tiffany G.; Gaiser, Evelyn; Barr, Jordan; Fuentes, Jose D.; Jaffe, Rudolf; Childers, Daniel L.; Collado-Vides, Ligia; Rivera-Monroy, Victor H.; Castañeda-Moya, Edward; Anderson, William; Chambers, Randy; Chen, Meilian; Coronado-Molina, Carlos; Davis, Stephen E.; Engel, Victor C.; Fitz, Carl; Fourqurean, James; Frankovich, Tom; Kominoski, John; Madden, Chris; Malone, Sparkle L.; Oberbauer, Steve F.; Olivas, Paulo; Richards, Jennifer; Saunders, Colin; Schedlbauer, Jessica; Scinto, Leonard J.; Sklar, Fred; Smith, Thomas J., III; Smoak, Joseph M.; Starr, Gregory; Twilley, Robert; Whelan, Kevin

    2013-01-01

    Recent studies suggest that coastal ecosystems can bury significantly more C than tropical forests, indicating that continued coastal development and exposure to sea level rise and storms will have global biogeochemical consequences. The Florida Coastal Everglades Long Term Ecological Research (FCE LTER) site provides an excellent subtropical system for examining carbon (C) balance because of its exposure to historical changes in freshwater distribution and sea level rise and its history of significant long-term carbon-cycling studies. FCE LTER scientists used net ecosystem C balance and net ecosystem exchange data to estimate C budgets for riverine mangrove, freshwater marsh, and seagrass meadows, providing insights into the magnitude of C accumulation and lateral aquatic C transport. Rates of net C production in the riverine mangrove forest exceeded those reported for many tropical systems, including terrestrial forests, but there are considerable uncertainties around those estimates due to the high potential for gain and loss of C through aquatic fluxes. C production was approximately balanced between gain and loss in Everglades marshes; however, the contribution of periphyton increases uncertainty in these estimates. Moreover, while the approaches used for these initial estimates were informative, a resolved approach for addressing areas of uncertainty is critically needed for coastal wetland ecosystems. Once resolved, these C balance estimates, in conjunction with an understanding of drivers and key ecosystem feedbacks, can inform cross-system studies of ecosystem response to long-term changes in climate, hydrologic management, and other land use along coastlines

  6. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    SciTech Connect

    Thomas E. Williams; Keith Millheim; Buddy King

    2003-12-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the US have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project is in the second year of a three-year endeavor being sponsored by maurer Technology, noble, and Anadarko Petroleum, in partnership with the DOE. The purpose of the project is to build on previous and ongoing R and D in the area of onshore hydrate deposition. They plan to identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. They also plan to design and implement a program to safely and economically drill, core and produce gas from arctic hydrates. The current work scope is to drill and core a well on Anadarko leases in FY 2003 and 2004. They are also using an on-site core analysis laboratory to determine some of the physical characteristics of the hydrates and surrounding rock. The well is being drilled from a new Anadarko Arctic Platform that will have minimal footprint and environmental impact. They hope to correlate geology, geophysics, logs, and drilling and production data to allow reservoir models to be calibrated. Ultimately, the goal is to form an objective technical and economic evaluation of reservoir potential in Alaska.

  7. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    SciTech Connect

    Thomas E. Williams; Keith Millheim; Buddy King

    2004-03-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project is in the second year of a three-year endeavor being sponsored by Maurer Technology, Noble, and Anadarko Petroleum, in partnership with the DOE. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition. We plan to identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. We also plan to design and implement a program to safely and economically drill, core and produce gas from arctic hydrates. The current work scope is to drill and core a well on Anadarko leases in FY 2003 and 2004. We are also using an on-site core analysis laboratory to determine some of the physical characteristics of the hydrates and surrounding rock. The well is being drilled from a new Anadarko Arctic Platform that will have minimal footprint and environmental impact. We hope to correlate geology, geophysics, logs, and drilling and production data to allow reservoir models to be calibrated. Ultimately, our goal is to form an objective technical and economic evaluation of reservoir potential in Alaska.

  8. Mercury and major element snowmelt chemistry at an Alaskan Arctic coastal site

    NASA Astrophysics Data System (ADS)

    Douglas, T. A.; Prevost, R.; Sturm, M.; Blum, J. D.; Sherman, L.; Berezovskaya, S.

    2008-12-01

    Mercury is deposited to snow in Polar Regions during the late winter and early spring. This deposition is driven by photochemical reactions that involve reactive halogens and snow and ice surfaces. The Arctic also receives trace metals, sulfate and black carbon during spring time Arctic haze events. Mercury, Arctic haze metals and sulfate in Arctic snow are likely mobilized during metamorphism, melt and surface runoff in the spring. To investigate this we implemented a daily sampling campaign for mercury and major elements during spring snow melt near Barrow, Alaska in 2008. The area is underlain by continuous permafrost and there is no base flow in the winter. We focused on a small (52,000 m2) ephemeral stream watershed to quantify chemical fluxes at the microscale. Prior to the melt the snow pack was 35 cm high with a density of 0.3 g/cm3. The snow pack height was measured daily at 15 locations along two 1 kilometer long transects throughout the melt to track snow pack loss. Discharge in our micro watershed was measured using a sonic sounder above a small dam constructed in the stream bed and by quantifying flow through a PVC pipe at the dam outlet. Percolation columns began to migrate downward through the snow pack on May 26 and within two days the snow pack was isothermal. Flow in the micro watershed began as a slushy trickle on May 28 that increased to a steady flow by June 4. Peak discharge rates of slightly over 3 L/sec were measured in the late afternoons on June 7, 8 and 9. By June 9 slightly more than half the tundra surface was exposed and snow was relegated to low lying areas. The first melt water to pool at the base of the snow pack had the highest cation (sodium, potassium, magnesium, calcium, and ammonium) and anion (chloride, bromide, sulfate, nitrate, bicarbonate) concentrations of all inorganic ions measured in snow, melt water or surface runoff. These major element concentrations were 5 to 10 times higher than pre melt snow pack values. The pre-melt snow pack surface 1 cm yielded a mercury concentration of 56 ng/L with three other layers comprising the remainder of the snow pack yielding mercury concentrations between 11 and 19 ng/L. Snow melt water at the base of the snow pack on May 28 yielded initial mercury concentrations of 55 ng/L and melt water mercury values remained between 25 and 102 ng/L until June 6 when discharge began to increase markedly. As discharge increased the mercury concentrations decreased to between 10 and 25 ng/L. Taken in total, our results suggest that there is an "ionic pulse" of major elements and mercury from the snow pack during the initial stages of snow melt. Though we cannot address the bioavailability of mercury in the Arctic ecosystem during snow melt our results suggest that mercury monitoring campaigns should focus on spring melt.

  9. Recent and Holocene climate change controls on vegetation and carbon accumulation in Alaskan coastal muskegs

    NASA Astrophysics Data System (ADS)

    Peteet, Dorothy M.; Nichols, Jonathan E.; Moy, Christopher M.; McGeachy, Alicia; Perez, Max

    2016-01-01

    Pollen, spore, macrofossil and carbon data from a peatland near Cordova, Alaska, reveal insights into the climate-vegetation-carbon interactions from the initiation of the Holocene, c. the last 11.5 ka, to the present (1 ka = 1000 calibrated years before present where 0 = 1950 CE). The Holocene period is characterized by early deposition of gyttja in a pond environment with aquatics such as Nuphar polysepalum and Potamogeton, and a significant regional presence of Alnus crispa subsp. sinuata. Carbon accumulation (50 g/m2/a) was high for a short interval in the early Holocene when Sphagnum peat accumulated, but was followed by a major decline to 13 g/m2/a from 7 to 3.7 ka when Cyperaceae and ericads such as Rhododendron (formerly Ledum) groenlandicum expanded. This shift to sedge growth is representative of many peatlands throughout the south-central region of Alaska, and indicates a drier, more evaporative environment with a large decline in carbon storage. The subsequent return to Sphagnum peat after 4 ka in the Neoglacial represents a widespread shift to moister, cooler conditions, which favored a resurgence of ericads, such as Andromeda polifolia, and increased carbon accumulation rate. The sustained Alnus expansion visible in the top 10 cm of the peat profile is correlative with glacial retreat and warming of the region in the last century, and suggests this colonization will continue as temperature increases and ice melts.

  10. Vertical profiles of trapped greenhouse gases in Alaskan permafrost active layers before the spring thaw

    NASA Astrophysics Data System (ADS)

    Byun, Eunji; Yang, Ji-woong; Kim, Yongwon; Ahn, Jinho

    2015-04-01

    Seasonally frozen ground over permafrost is important in controlling annual greenhouse gas exchange between permafrost and atmosphere. Soil microbes decompose soil carbon and generate carbon dioxide and methane when they become activated. However, the actual greenhouse gas emission follows various efflux pathways. For example, seasonal freezing of the top soil layers can either restrain or press the gas emission from deeper layers. It has been reported that abrupt release of methane during spring is attributable to the emission of trapped gases that had failed to be released instantly after formation (1, 2). In order to examine the seasonally trapped greenhouse gases, we drilled five Alaskan permafrost cores before spring thaw; one from coastal tundra, two from typical boreal forests, one from area where fire occurred, and one from peat accumulated sites. Vertical profiles of carbon dioxide and methane concentrations were obtained with 5-10 cm depth intervals. We found methane peaks from two cores, indicating inhibition of methane efflux. We also analyzed organic carbon, nitrogen and water contents and compared them with the greenhouse gas profiles. We are continuing analysis for the soil temperature profiles of the sampling boreholes because the detailed temperature information might be related to microbial activity, and can be used as indirect indicators of soil water freezing and latent heat influences at some active layer depth (zero curtain effects). All the high-resolution analyses for subsurface environments may help to improve understanding greenhouse gas emission from permafrost regions. 1. Mastepanov M, et al. (2008) Large tundra methane burst during onset of freezing. Nature 456(7222):628-630. 2. Song C, et al. (2012) Large methane emission upon spring thaw from natural wetlands in the northern permafrost region. Environmental Research Letters 7(3):034009.

  11. Coastal flood management in Semarang, Indonesia

    NASA Astrophysics Data System (ADS)

    Marfai, Muh Aris; King, Lorenz

    2008-10-01

    Semarang is one of the biggest cities in Indonesia and is nowadays suffering from coastal flooding. Land subsidences, high water tide, and inadequate structural measures play important roles in the coastal inundations. Structural and non-structural methods for controlling coastal flooding including dykes, drainage systems, pump stations, polder systems, coastal-land reclamations, coastal planning and management, public education, as well as the establishment of an institutional framework for disaster management have been implemented in the Semarang coastal area. Although some improvements have been made, the current flood management system has generally failed to address a wide range of coastal inundation problems. Some improvement actions have been proposed including stakeholders involvement on the disaster mitigation. For a long period coastal management, accelerated sea level rises due to global warming should also be taken into account.

  12. Air-cushion tankers for Alaskan North Slope oil

    NASA Technical Reports Server (NTRS)

    Anderson, J. L.

    1973-01-01

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

  13. Applications of remote sensing data to the Alaskan environment

    NASA Technical Reports Server (NTRS)

    Belon, A. E.; Iller, J. M.

    1973-01-01

    The ERTS program provides a means to overcome the formidable logistic and economic costs of preparing environmental surveys of the vast and relatively unexplored regions of Alaska. There is an excellent potential in satellite remote sensing to benefit Federal, state, local, and private agencies, by providing a new synoptic data base which is necessary for the preparation of the needed surveys and the search for solutions to environmental management problems. One approach in coupling satellite data to Alaskan problems is a major program initiated by the University of Alaska and funded by NASA's Goddard Space Flight Center. This included 12 projects whose aims were to study the feasibility of applying ERTS data to the disciplines of ecology, agriculture, hydrology, wildlife management, oceanography, geology, glaciology, volcanology, and archaeology.

  14. Development of Alaskan gas hydrate resources. Final report

    SciTech Connect

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

    1991-06-01

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

  15. Ambient noise tomography across the southern Alaskan Cordillera

    NASA Astrophysics Data System (ADS)

    Ward, Kevin M.

    2015-05-01

    I present the results of an extensive data mining effort integrating 197 permanent and temporary seismic stations into a Rayleigh wave ambient noise study across southern Alaska and westernmost Canada. Principal observations of my tomography model are largely consistent with mapped geology features and previous geophysical studies while providing previously unavailable, laterally continuous details of the southern Alaskan Cordillera lithosphere. At intermediate periods, a geophysically uniform crust is observed north of the Denali Fault and is consistent with a sharp transition in crustal thickness. Under the Wrangell volcanic belt, a prominent low-phase-velocity anomaly correlates well with the lateral extent of a relative low-gravity anomaly and Neogene surface volcanics. At longer periods, a low-phase-velocity anomaly bounds the inferred eastern extent of the subducted Yakutat microplate beneath the Wrangell volcanic belt.

  16. Prediction of the weight of Alaskan pollock using image analysis.

    PubMed

    Balaban, Murat O; Chombeau, Melanie; Cırban, Dilşat; Gümüş, Bahar

    2010-10-01

    Determining the size and quality attributes of fish by machine vision is gaining acceptance and increasing use in the seafood industry. Objectivity, speed, and record keeping are advantages in using this method. The objective of this work was to develop the mathematical correlations to predict the weight of whole Alaskan Pollock (Theragra chalcogramma) based on its view area from a camera. One hundred and sixty whole Pollock were obtained fresh, within 2 d after catch from a Kodiak, Alaska, processing plant. The fish were first weighed, then placed in a light box equipped with a Nikon D200 digital camera. A reference square of known surface area was placed by the fish. The obtained image was analyzed to calculate the view area of each fish. The following equations were used to fit the view area (X) compared with weight (Y) data: linear, power, and 2nd-order polynomial. The power fit (Y = A · X(B)) gave the highest R(2) for the fit (0.99). The effect of fins and tail on the accuracy of the weight prediction using view area were evaluated. Removing fins and tails did not improve prediction accuracy. Machine vision can accurately predict the weight of whole Pollock. Practical Application: The weight of Alaskan Pollock can be predicted automatically by taking the image of the fish and using it in one of the correlations developed in this study. The removal of the fins or the fins and the tail did not increase the prediction accuracy of the method. Therefore, intact fish images should be used. PMID:21535495

  17. Linkage among Vegetation, Microbes and Methanogenic Pathways in Alaskan Peatlands

    NASA Astrophysics Data System (ADS)

    Zhang, L.; Sidelinger, W.; Shu, H.; Varner, R. K.; Hines, M. E.

    2014-12-01

    Northern wetlands are thought to account for one third of the naturally emitted CH4. However, methane production pathways in northern peatlands are poorly understood, yet are predicted to change in response to vegetation shifts due to warming. Previous studies noted that acetate conversion to methane (acetoclastic methanogenesis, AM) in northern wetlands is largely impeded and acetate accumulates, however AM tends to increase with minerotrophy. To understand methanogenic pathways and to provide linkage among pathways, we studied Alaskan wetlands in 2013 and 2014. In 2013, laboratory incubations were conducted in three peatlands representing trophic gradients from bogs to fens. During 2014, 37 different sites in Fairbanks and Anchorage were studied that represented wetlands with pH values from 3.5 to 5.5 and vegetation from primarily Sphagnum to sedges. Measurements in 2014 included vegetation composition, gases (CH4, CO2, H2, and CO), 13CH4 and 13CO2, volatile fatty acids, DOC, other electron acceptors. Further incubation studies are being conducted to decipher controls on decomposition pathways. Gene sequencing was used to characterize microbial community composition, and metagenomic and transcriptomics were conducted to describe community activity. Results showed that methanogenesis was higher in fens than bogs, but hydrogenotrophic methanogenesis (HM) was dominant at all sites. End product ratios showed that AM was occurring in fens, albeit slowly. Fermentation was an important end-point in decomposition and microbial syntrophy was weak. These data, regardless of trophic status, differed greatly from data obtained from temperate wetlands in which terminal respiratory processes were strong and C flow through syntrophy was important. Trophic status influenced C flow in the Alaskan sites, but terminal processes were weak and end product formation tended to end at primary fermentation, which dominated as the terminal step in decomposition.

  18. Arctic Coastal Erosion Modeling

    NASA Astrophysics Data System (ADS)

    Ravens, T. M.; Jones, B.; Zhang, J.; Tweedie, C. E.; Erikson, L. H.; Gibbs, A.; Richmond, B. M.

    2011-12-01

    A process-based coastal erosion/shoreline change model has been developed for Arctic coastal bluffs subject to niche erosion/block collapse. The model explicitly accounts for many environmental/geographic variables including: water temperature, water level, wave height, and bluff height. The model was originally developed for a small coastal segment near Drew Point, Beaufort Sea, Alaska. This coastal setting has experienced a dramatic increase in erosion since the early 2000's. The bluffs at this site are 3-4 m tall and consist of ice-wedge bounded blocks of fine-grained sediments cemented by ice-rich permafrost and capped with a thin organic layer. The bluffs are typically fronted by a narrow (~ 5 m wide) beach or none at all. During a storm surge, the sea contacts the base of the bluff and a niche is formed through thermal and mechanical erosion. The niche grows both vertically and laterally and eventually undermines the bluff, leading to block failure or collapse. The fallen block is then eroded both thermally and mechanically by waves and currents, which must occur before a new niche forming episode may begin. The model has been calibrated based on shoreline change data at Drew Point for two time periods: 1979-2002 and 2002-2007. Measured and modeled shoreline change rates were about 8 m/yr and 16 m/yr, for the earlier and later periods, respectively. In this paper, this work is extended to include modeling and measurement of coastal erosion at Drew Point on an annual basis for the period 2007-2010. In addition, the model is applied at three other Arctic coastal locations - Elson Lagoon, Cape Halkett, and Barter Island - where niche erosion/block collapse prevails.

  19. Evidence for the Incorporation of Terrestrial Carbon in Arctic Coastal Food Webs in the Western Beaufort Sea

    NASA Astrophysics Data System (ADS)

    Dunton, K.; Weingartner, T.; Carmack, E.

    2006-12-01

    The nearshore shelf of the Beaufort Sea is defined by extreme physical and biological gradients that have a distinctive influence on its productivity and trophic structure. Massive freshwater discharge from the Mackenzie River, along with numerous smaller rivers and streams elsewhere along the coast, produce an environment that is decidedly estuarine in character, especially in late spring and summer. Because of its low in situ productivity, allochthonous inputs of organic carbon, identifiable on the basis of isotopic values, are important to the functioning of this arctic estuarine system. Coastal erosion and river discharge are largely responsible for introducing high concentrations of suspended sediment from upland regions into the nearshore zone. The depletion in the 13C content of invertebrate and vertebrate consumers, which drops about 4-5 ppt eastward along the eastern Alaskan Beaufort Sea coast, may reflect the assimilation of this terrestrial organic matter into local food webs. Isotopic tracer studies of amphidromous fishes in the Simpson Island barrier island lagoon ecosystem revealed that terrestrial (peat) carbon may contribute as much as 30 to 50% of their total dietary requirements. On the eastern Alaska Beaufort Sea coast, carbon isotopic values of arctic cod collected in semi-enclosed lagoons were more depleted by 3-4 ppt compared to fish collected in the coastal Beaufort Sea. Calculations from isotopic mixing equations indicate cod from lagoons may derive 70% of their carbon from terrestrial sources. Nitrogen isotopic values of lagoon fish were also 4 ppt lower than coastal specimens, reflective of the lower del 15N values of terrestrial derived nitrogen (0-1.5 ppt compared to 5-7 ppt for phytoplankton). The possible role of terrestrially derived carbon to arctic estuarine food webs is especially important in view of the current warming trend in the arctic environment and the role of advective processes that transport carbon along the nearshore

  20. Coastal Upwelling.

    ERIC Educational Resources Information Center

    Clark, Steve

    1998-01-01

    Features a three-part activity designed to teach students about coastal upwelling, the upward movement of cooler, more nutrient-rich water along a coast. Activity includes a mapping exercise, a graphing exercise, and questions for analyzing the map and graph. (Author/WRM)

  1. COASTAL GUIDELINES

    EPA Science Inventory

    Resource Purpose:Developed to support effluent guidelines for the coastal subcategory of the oil and gas extraction industry. Data were used to develop environmental impacts, potential regulatory limits, and the cost of regulation.
    Legislation/Enabling Authority:...

  2. Transport of Alaskan Dust into the Gulf of Alaska and Comparison with Similar High-Latitude Dust Environments

    NASA Technical Reports Server (NTRS)

    Crusium, John; Levy, Rob; Wang, Jun; Campbell, Rob; Schroth, Andrew W.

    2012-01-01

    Transport of Alaskan dust into the Gulf of Alaska and comparison with similar high-latitude dust environments. An airborne flux of the micronutrient iron, derived from dust originating from coastal regions may be an important contributor of iron to the Gulf of Alaska's (GoA) oligotrophic waters. Dust blowing off glacier termini and dry riverbeds is a recurring phenomenon in Alaska, usually occurring in the autumn. Since previous studies assumed that dust originating in the deserts of Asia was the largest source of . airborne iron to the GoA, the budget of aeolian deposition of iron needs to be reassessed. Since late 20 I 0, our group has been monitoring dust activity using satellites over the Copper River Delta (CRD) where the most vigorous dust plumes have been observed. Since 2011, sample aerosol concentration and their composition are being collected at Middleton Island (100km off shore of CRD). This presentation will show a summary of the ongoing dust observations and compare with other similar environments (Patagonia, Iceland) by showing case studies. Common features will be highlighted

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

    USGS Publications Warehouse

    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.

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

    SciTech Connect

    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.

  5. Psychrotrophic strain of Janthinobacterium lividum from a cold Alaskan soil produces prodigiosin.

    PubMed

    Schloss, Patrick D; Allen, Heather K; Klimowicz, Amy K; Mlot, Christine; Gross, Jessica A; Savengsuksa, Sarah; McEllin, Jennifer; Clardy, Jon; Ruess, Roger W; Handelsman, Jo

    2010-09-01

    We have explored the microbial community in a nonpermafrost, cold Alaskan soil using both culture-based and culture-independent approaches. In the present study, we cultured >1000 bacterial isolates from this soil and characterized the collection of isolates phylogenetically and functionally. A screen for antibiosis identified an atypical, red-pigmented strain of Janthinobacterium lividum (strain BR01) that produced prodigiosin when grown at cool temperatures as well as strains (e.g., strain BP01) that are more typical of J. lividium, which produce a purple pigment, violacein. Both purple- and red-pigmented strains exhibited high levels of resistance to beta-lactam antibiotics. The prodigiosin pathway cloned from J. lividium BR01 was expressed in the heterologous host, Escherichia coli, and the responsible gene cluster differs from that of a well-studied prodigiosin producer, Serratia sp. J. lividum BR01 is the first example of a prodigiosin-producer among the beta-Proteobacteria. The results show that characterization of cultured organisms from previously unexplored environments can expand the current portrait of the microbial world. PMID:20626288

  6. Physical processes that enhance nutrient transport and primary productivity in the coastal and open ocean of the subarctic NE Pacific

    NASA Astrophysics Data System (ADS)

    Whitney, F. A.; Crawford, W. R.; Harrison, P. J.

    2005-03-01

    In comparison to the open ocean, several additional processes including coastal upwelling, river discharge, tidal mixing, estuarine circulation and benthic remineralization enhance nutrient supply to the surface waters of the continental shelf. In general, coastal waters become nitrate-limited during the phytoplankton growing season, whereas iron and dissolved silicate limit phytoplankton growth in the less productive oceanic waters of the Gulf of Alaska. If coastal processes supply ample amounts of macro and micro nutrients during the growing season, diatom communities dominated by species such as Skeletomema costatum, Chaetoceros spp. and Thalassiosira spp. will bloom. Growth rates of these bloom populations typically range from 0.5 to >1.5 doublings per day, which place a high demand on nutrients. Any transport of coastal waters away from the shelf will enhance productivity in oceanic waters. The general circulation of the eastern subarctic Pacific does not allow for offshore transport except in special circumstances. These include anticyclonic mesoscale eddy formation, which can export as much as 5000 km 3 of nutrient-rich waters from the shelf in a single eddy, and recirculation of waters away from southwestern Alaska due to the cyclonic circulation around the western edge of the Alaskan Gyre. Recirculation can carry nutrient-rich water from the coast to the vicinity of Ocean Station Papa (50°N, 145°W) within a few months. For both eddies and gyre recirculation, much of the water being carried into the open ocean lies below the euphotic zone. Iron enrichment occurs to a depth of at least 1000 m in the Gulf of Alaska as a result. Periods of enhanced eddy formation or recirculation may supply iron that enriches the open ocean for several years. Damming of the Columbia River and human uses of its waters have resulted in more winter and less summer discharge of fresh water and dissolved Si. Coastal currents in this area flow north in winter and south in summer

  7. Ice loss and sea level rise contribution from Alaskan glaciers

    NASA Astrophysics Data System (ADS)

    Berthier, E.; Schiefer, E.; Clarke, G. K.; Menounos, B.; Rémy, F.; Cazenave, A. A.

    2009-12-01

    Over the last 50 years, retreating glaciers and ice caps (GIC) contributed 0.5 mm/yr to SLR, and one third is believed to originate from ice masses bordering the Gulf of Alaska. However, these estimates of ice wastage in Alaska are based on methods that directly measure mass changes from a limited number of glaciers and extrapolate the results to estimate ice loss for the many thousands of others. Here, using a new glacier inventory with elevation changes derived from sequential digital elevation models (DEMs), we found that, between 1962 and 2006, Alaskan glaciers lost 41.9 ± 8.6 km**3/yr water equivalent (w.e.) and contributed 0.12 ± 0.02 mm/yr to SLR. Our ice loss is 34% lower than previous estimates. Reasons for our lower values include the higher spatial resolution of the glacier inventory used in our study and the complex pattern of ice elevation changes at the scale of individual glaciers and mountain ranges which was not resolved in earlier work. Our ice elevation changes reveal that glacier dynamics (surges, phase of the tidewater cycle, etc...) have a profound effect on the wastage of Alaska glaciers. 3D satellite view of Columbia glacier, Chugach Mountains, Alaska. (Copyright CNES 2007, Distribution Spot Image, processing E. Berthier CNRS)

  8. Emissions of biogenic sulfur gases from Alaskan tundra

    NASA Technical Reports Server (NTRS)

    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.

  9. A Formal Messaging Notation for Alaskan Aviation Data

    NASA Technical Reports Server (NTRS)

    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.

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

    USGS Publications Warehouse

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

    2011-01-01

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

  11. Quantifying seismic survey reverberation off the Alaskan North Slope.

    PubMed

    Guerra, Melania; Thode, Aaron M; Blackwell, Susanna B; Michael Macrander, A

    2011-11-01

    Shallow-water airgun survey activities off the North Slope of Alaska generate impulsive sounds that are the focus of much regulatory attention. Reverberation from repetitive airgun shots, however, can also increase background noise levels, which can decrease the detection range of nearby passive acoustic monitoring (PAM) systems. Typical acoustic metrics for impulsive signals provide no quantitative information about reverberation or its relative effect on the ambient acoustic environment. Here, two conservative metrics are defined for quantifying reverberation: a minimum level metric measures reverberation levels that exist between airgun pulse arrivals, while a reverberation metric estimates the relative magnitude of reverberation vs expected ambient levels in the hypothetical absence of airgun activity, using satellite-measured wind data. The metrics are applied to acoustic data measured by autonomous recorders in the Alaskan Beaufort Sea in 2008 and demonstrate how seismic surveys can increase the background noise over natural ambient levels by 30-45 dB within 1 km of the activity, by 10-25 dB within 15 km of the activity, and by a few dB at 128 km range. These results suggest that shallow-water reverberation would reduce the performance of nearby PAM systems when monitoring for marine mammals within a few kilometers of shallow-water seismic surveys. PMID:22087932

  12. 33 CFR 334.1290 - In Bering Sea, Shemya Island Area, Alaska; meteorological rocket launching facility, Alaskan Air...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., Alaska; meteorological rocket launching facility, Alaskan Air Command, U.S. Air Force. 334.1290 Section...; meteorological rocket launching facility, Alaskan Air Command, U.S. Air Force. (a) The danger zone. An arc of a...) Rockets will normally be launched one each day Monday through Friday between 9 a.m. and 3 p.m....

  13. 33 CFR 334.1290 - In Bering Sea, Shemya Island Area, Alaska; meteorological rocket launching facility, Alaskan Air...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., Alaska; meteorological rocket launching facility, Alaskan Air Command, U.S. Air Force. 334.1290 Section...; meteorological rocket launching facility, Alaskan Air Command, U.S. Air Force. (a) The danger zone. An arc of a...) Rockets will normally be launched one each day Monday through Friday between 9 a.m. and 3 p.m....

  14. 33 CFR 334.1290 - In Bering Sea, Shemya Island Area, Alaska; meteorological rocket launching facility, Alaskan Air...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., Alaska; meteorological rocket launching facility, Alaskan Air Command, U.S. Air Force. 334.1290 Section...; meteorological rocket launching facility, Alaskan Air Command, U.S. Air Force. (a) The danger zone. An arc of a...) Rockets will normally be launched one each day Monday through Friday between 9 a.m. and 3 p.m....

  15. 33 CFR 334.1290 - In Bering Sea, Shemya Island Area, Alaska; meteorological rocket launching facility, Alaskan Air...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., Alaska; meteorological rocket launching facility, Alaskan Air Command, U.S. Air Force. 334.1290 Section...; meteorological rocket launching facility, Alaskan Air Command, U.S. Air Force. (a) The danger zone. An arc of a...) Rockets will normally be launched one each day Monday through Friday between 9 a.m. and 3 p.m....

  16. 33 CFR 334.1290 - In Bering Sea, Shemya Island Area, Alaska; meteorological rocket launching facility, Alaskan Air...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., Alaska; meteorological rocket launching facility, Alaskan Air Command, U.S. Air Force. 334.1290 Section...; meteorological rocket launching facility, Alaskan Air Command, U.S. Air Force. (a) The danger zone. An arc of a...) Rockets will normally be launched one each day Monday through Friday between 9 a.m. and 3 p.m....

  17. 25 CFR 243.6 - Which sales or transfers of Alaskan reindeer do not require a permit?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Which sales or transfers of Alaskan reindeer do not... AND WILDLIFE REINDEER IN ALASKA § 243.6 Which sales or transfers of Alaskan reindeer do not require a... reindeer or reindeer products; and (b) Sale of transfer of live reindeer between Alaska Natives or...

  18. 25 CFR 243.6 - Which sales or transfers of Alaskan reindeer do not require a permit?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Which sales or transfers of Alaskan reindeer do not... AND WILDLIFE REINDEER IN ALASKA § 243.6 Which sales or transfers of Alaskan reindeer do not require a... reindeer or reindeer products; and (b) Sale of transfer of live reindeer between Alaska Natives or...

  19. 25 CFR 243.6 - Which sales or transfers of Alaskan reindeer do not require a permit?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Which sales or transfers of Alaskan reindeer do not... AND WILDLIFE REINDEER IN ALASKA § 243.6 Which sales or transfers of Alaskan reindeer do not require a... reindeer or reindeer products; and (b) Sale of transfer of live reindeer between Alaska Natives or...

  20. 25 CFR 243.6 - Which sales or transfers of Alaskan reindeer do not require a permit?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Which sales or transfers of Alaskan reindeer do not... AND WILDLIFE REINDEER IN ALASKA § 243.6 Which sales or transfers of Alaskan reindeer do not require a... reindeer or reindeer products; and (b) Sale of transfer of live reindeer between Alaska Natives or...

  1. 25 CFR 243.6 - Which sales or transfers of Alaskan reindeer do not require a permit?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Which sales or transfers of Alaskan reindeer do not... AND WILDLIFE REINDEER IN ALASKA § 243.6 Which sales or transfers of Alaskan reindeer do not require a... reindeer or reindeer products; and (b) Sale of transfer of live reindeer between Alaska Natives or...

  2. Ventilation of North Pacific Intermediate Waters - The role of the Alaskan Gyre

    NASA Technical Reports Server (NTRS)

    Van Scoy, Kim A.; Olson, Donald B.; Fine, Rana A.

    1991-01-01

    Hydrographic data, tritium data, and potential vorticity calculations suggest that although North Pacific Intermediate Water is formed in the northwest, the Alaskan Gyre might be an additional ventilation site. The proposed ventilation is quantified by a vertical column tritium inventory, which indicates an excess of 0.08 kg of tritium in the Alaskan Gyre. An evaluation of the energy stored in the water column and of wind and buoyancy forcing shows that during winter conditions enough energy can be pumped into the system to force 26.80 sigma(theta) to outcrop in the Alaskan Gyre. Model results suggest that relatively limited outcrops in time and space (tens of days and several hundred kilometers in diameter) can account for the excess tritium.

  3. Coastal circulation and water-column properties in the War in the Pacific National Historical Park, Guam: measurements and modeling of waves, currents, temperature, salinity, and turbidity, April-August 2012

    USGS Publications Warehouse

    Storlazzi, Curt D.; Cheriton, Olivia M.; Lescinski, Jamie M.R.; Logan, Joshua B.

    2014-01-01

    The U.S. Geological Survey (USGS) Pacific Coastal and Marine Science Center (PCMSC) initiated an investigation in the National Park Service’s (NPS) War in the Pacific National Historical Park (WAPA) to provide baseline scientific information on coastal circulation and water-column properties along west-central Guam, focusing on WAPA’s Agat Unit, as it relates to the transport and settlement of coral larvae, fish, and other marine organisms. The oceanographic data and numerical circulation modeling results from this study demonstrate that circulation in Agat Bay was strongly driven by winds and waves at longer (>1 day) timescales and by the tides at shorter (<1 day) timescales; near-surface currents in deep water were primarily controlled by the winds, whereas currents on the shallow reef flats were dominated by wave-driven motions. Water-column properties exhibited strong seasonality coupled to the shift from the trade wind to the non-trade wind season. During the dry trade-wind season, waters were cooler and more saline. When the winds shifted to a more variable pattern, waters warmed and became less saline because of a combination of increased thermal insolation from lack of wind forcing and higher rainfall. Turbidity was relatively low in Agat Bay and was similar to levels measured elsewhere along west-central Guam. The numerical circulation modeling results provide insight into the potential paths of buoyant material released from a series of locations along west-central Guam under summer non-trade wind forcing conditions that characterize coral spawning events. This information may be useful in evaluating the potential zones of influence/impact resulting from transport by surface currents of material released from these select locations.

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

    PubMed Central

    2010-01-01

    Background The Alaskan sled dog offers a rare opportunity to investigate the development of a dog breed based solely on performance, rather than appearance, thus setting the breed apart from most others. Several established breeds, many of which are recognized by the American Kennel Club (AKC), have been introduced into the sled dog population to enhance racing performance. We have used molecular methods to ascertain the constitutive breeds used to develop successful sled dog lines, and in doing so, determined the breed origins of specific performance-related behaviors. One hundred and ninety-nine Alaskan sled dogs were genotyped using 96 microsatellite markers that span the canine genome. These data were compared to that from 141 similarly genotyped purebred dog breeds. Sled dogs were evaluated for breed composition based on a variety of performance phenotypes including speed, endurance and work ethic, and the data stratified based on population structure. Results We observe that the Alaskan sled dog has a unique molecular signature and that the genetic profile is sufficient for identifying dogs bred for sprint versus distance. When evaluating contributions of existing breeds we find that the Alaskan Malamute and Siberian Husky contributions are associated with enhanced endurance; Pointer and Saluki are associated with enhanced speed and the Anatolian Shepherd demonstrates a positive influence on work ethic. Conclusion We have established a genetic breed profile for the Alaskan sled dog, identified profile variance between sprint and distance dogs, and established breeds associated with enhanced performance attributes. These data set the stage for mapping studies aimed at finding genes that are associated with athletic attributes integral to the high performing Alaskan sled dog. PMID:20649949

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

    PubMed

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

    2016-12-01

    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

  6. Coastal scale operational oceanography with structural interactions

    NASA Astrophysics Data System (ADS)

    Sánchez-Arcilla, Agustín; García León, Manuel; Gracia, Vicente; Pau Sierra, Joan; Espino, Manuel; Grifoll, Manuel

    2015-04-01

    Operational oceanography predictions are now starting to include coupled wind, wave and current fields for open ocean and shelf domains. However the same product for coastal scales, including a) the non-linearity of coastal processes, b) the effect of continental rain driven discharge and c) the interaction with coastal structures are still in an early stage of development, both for the physical and numerical aspects. In this paper we shall explore a coupled wind-wave-current model based on the COWAST system but including also the continental discharge and the effect of coastal structures, in particular shore parallel detached breakwaters. We shall apply such a pre-operational code to a test case near Barcelona, where the concept of transient coastal defences is being considered. The available in-situ and remote observations should also allow a robust calibration. The operational oceanography simulations will be used to support the activation of these transient coastal defences and therefore illustrate the challenges required by coastal scales under rapid storm development such as is commonly found in the Western Mediterranean. The benefits of applying a robust and high resolution coupled hydro-dynamic system will become apparent from the stand point of transient coastal defence deployment and risk mitigation in heavily populated coastal areas.

  7. Oregon Coastal Observing System

    NASA Astrophysics Data System (ADS)

    Kosro, M.; Allen, J. S.; Barth, J. A.; Egbert, G. D.; Huyer, A.; Smith, R. L.; Grantham, B. A.; Lubchenco, J.; Menge, B. A.

    2002-12-01

    Since 1997, a growing system of sustained coastal measurements, together with a high-resolution, data-assimilating coastal modeling program, have been used off Oregon to study the response of the coastal ocean to forcing at a range of space and time scales. The measurements include a large array of HF radars, which permit time-series mapping of the surface circulation over most of the Oregon coast; both long-term and short-term moored components, which provide time-series sampling through the water column; and repeat hydrographic, ADCP and surface drifter sampling, including the Newport Hydrographic Line (which has been sampled since the 1960s). At interannual frequencies, these measurements show changes in the alongshore circulation over the continental slope accompanying ENSO. At seasonal and storm frequencies, the strength and persistence of spatial patterns in wind-driven currents and the importance of bathymetry in steering the circulation are seen. Discovery of episodic phenomena, such as the recent finding of a hypoxic pool and associated die-off of fish and crabs on the continental shelf off Heceta Head, are made possible by repeated sampling.

  8. Quantifying and comparing size selectivity among Alaskan sockeye salmon fisheries.

    PubMed

    Kendall, Neala W; Quinn, Thomas P

    2012-04-01

    Quantifying long-term size-selective harvest patterns is necessary for understanding the potential evolutionary effects on exploited species. The comparison of fishery selection patterns on the same species subject to different gear types, in different areas, and over multi-decadal periods can reveal the factors influencing selection. In this study we quantified and compared size-selective harvest by nine Alaskan sockeye salmon (Oncorhynchus nerka) fisheries to understand overall patterns. We calculated length-specific linear selection differentials (the difference in average length of fish before vs. after fishing), which are produced by different combinations of exploitation rates and length-selectivity values, and nonlinear standardized differentials, describing disruptive selection, across all years for each fishery. Selection differentials varied among years, but larger fish were caught in 73% of years for males and 84% of years for females, leaving smaller fish to spawn. Disruptive selection was observed on female and male fish in 84% and 92% of years, respectively. Linear selection was stronger on females than males in 77% of years examined, and disruptive selection was stronger on males in 71% of years. Selection pressure was influenced by a combination of factors under and beyond management control; analyses using mixed-effects models indicated that fisheries were less size selective in years when fish were larger than average and had lower exploitation rates. The observed harvest of larger than average sockeye salmon is consistent with the hypothesis that size-selective fishing contributes to decreasing age and length at maturation trends over time, but temporal variability in selection and strong disruptive selection suggests that the overall directional pressure is weaker than is often assumed in evolutionary models. PMID:22645812

  9. Contaminants in arctic snow collected over northwest Alaskan sea ice

    USGS Publications Warehouse

    Garbarino, J.R.; Snyder-Conn, E.; Leiker, T.J.; Hoffman, G.L.

    2002-01-01

    Snow cores were collected over sea ice from four northwest Alaskan Arctic estuaries that represented the annual snowfall from the 1995-1996 season. Dissolved trace metals, major cations and anions, total mercury, and organochlorine compounds were determined and compared to concentrations in previous arctic studies. Traces (<4 nanograms per liter, ng L-1) of cis- and trans-chlordane, dimethyl 2,3,5,6-tetrachloroterephthalate, dieldrin, endosulfan II, and PCBs were detected in some samples, with endosulfan I consistently present. High chlorpyrifos concentrations (70-80 ng L-1) also were estimated at three sites. The snow was highly enriched in sulfates (69- 394 mg L-1), with high proportions of nonsea salt sulfates at three of five sites (9 of 15 samples), thus indicating possible contamination through long-distance transport and deposition of sulfate-rich atmospheric aerosols. Mercury, cadmium, chromium, molybdenum, and uranium were typically higher in the marine snow (n = 15) in relation to snow from arctic terrestrial studies, whereas cations associated with terrigenous sources, such as aluminum, frequently were lower over the sea ice. One Kasegaluk Lagoon site (Chukchi Sea) had especially high concentrations of total mercury (mean = 214 ng L-1, standard deviation = 5 ng L-1), but no methyl mercury was detected above the method detection limit (0.036 ng L-1) at any of the sites. Elevated concentrations of sulfate, mercury, and certain heavy metals might indicate mechanisms of contaminant loss from the arctic atmosphere over marine water not previously reported over land areas. Scavenging by snow, fog, or riming processes and the high content of deposited halides might facilitate the loss of such contaminants from the atmosphere. Both the mercury and chlorpyrifos concentrations merit further investigation in view of their toxicity to aquatic organisms at low concentrations.

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

    NASA Astrophysics Data System (ADS)

    Moore, R. H.; Bahreini, R.; Brock, C. A.; Froyd, K. D.; Cozic, J.; Holloway, J. S.; Middlebrook, A. M.; Murphy, D. M.; Nenes, A.

    2011-08-01

    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 relatively pristine Arctic background conditions 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. Analysis of the individual mass spectral m/z 43 and 44 peaks from an aerosol mass spectrometer show the organic aerosols sampled to be well-oxygenated, consistent with 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 aerosol 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 measurements, 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.

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

    NASA Astrophysics Data System (ADS)

    Moore, R. H.; Bahreini, R.; Brock, C. A.; Froyd, K. D.; Cozic, J.; Holloway, J. S.; Middlebrook, A. M.; Murphy, D. M.; Nenes, A.

    2011-11-01

    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.

  12. Coastal Zone Color Scanner

    NASA Technical Reports Server (NTRS)

    Johnson, B.

    1988-01-01

    The Coastal Zone Color Scanner (CZCS) spacecraft ocean color instrument is capable of measuring and mapping global ocean surface chlorophyll concentration. It is a scanning radiometer with multiband capability. With new electronics and some mechanical, and optical re-work, it probably can be made flight worthy. Some additional components of a second flight model are also available. An engineering study and further tests are necessary to determine exactly what effort is required to properly prepare the instrument for spaceflight and the nature of interfaces to prospective spacecraft. The CZCS provides operational instrument capability for monitoring of ocean productivity and currents. It could be a simple, low cost alternative to developing new instruments for ocean color imaging. Researchers have determined that with global ocean color data they can: specify quantitatively the role of oceans in the global carbon cycle and other major biogeochemical cycles; determine the magnitude and variability of annual primary production by marine phytoplankton on a global scale; understand the fate of fluvial nutrients and their possible affect on carbon budgets; elucidate the coupling mechanism between upwelling and large scale patterns in ocean basins; answer questions concerning the large scale distribution and timing of spring blooms in the global ocean; acquire a better understanding of the processes associated with mixing along the edge of eddies, coastal currents, western boundary currents, etc., and acquire global data on marine optical properties.

  13. Greater shrub dominance alters breeding habitat and food resources for migratory songbirds in Alaskan arctic tundra.

    PubMed

    Boelman, Natalie T; Gough, Laura; Wingfield, John; Goetz, Scott; Asmus, Ashley; Chmura, Helen E; Krause, Jesse S; Perez, Jonathan H; Sweet, Shannan K; Guay, Kevin C

    2015-04-01

    Climate warming is affecting the Arctic in multiple ways, including via increased dominance of deciduous shrubs. Although many studies have focused on how this vegetation shift is altering nutrient cycling and energy balance, few have explicitly considered effects on tundra fauna, such as the millions of migratory songbirds that breed in northern regions every year. To understand how increasing deciduous shrub dominance may alter breeding songbird habitat, we quantified vegetation and arthropod community characteristics in both graminoid and shrub dominated tundra. We combined measurements of preferred nest site characteristics for Lapland longspurs (Calcarius lapponicus) and Gambel's White-crowned sparrows (Zonotrichia leucophrys gambelii) with modeled predictions for the distribution of plant community types in the Alaskan arctic foothills region for the year 2050. Lapland longspur nests were found in sedge-dominated tussock tundra where shrub height does not exceed 20 cm, whereas White-crowned sparrows nested only under shrubs between 20 cm and 1 m in height, with no preference for shrub species. Shrub canopies had higher canopy-dwelling arthropod availability (i.e. small flies and spiders) but lower ground-dwelling arthropod availability (i.e. large spiders and beetles). Since flies are the birds' preferred prey, increasing shrubs may result in a net enhancement in preferred prey availability. Acknowledging the coarse resolution of existing tundra vegetation models, we predict that by 2050 there will be a northward shift in current White-crowned sparrow habitat range and a 20-60% increase in their preferred habitat extent, while Lapland longspur habitat extent will be equivalently reduced. Our findings can be used to make first approximations of future habitat change for species with similar nesting requirements. However, we contend that as exemplified by this study's findings, existing tundra modeling tools cannot yet simulate the fine-scale habitat

  14. Twenty year record of vegetation change from long-term plots in Alaskan tundra

    NASA Astrophysics Data System (ADS)

    Gould, W. A.; Mercado Díaz, J. A.

    2008-12-01

    We examined change in plant species composition at two sites in the Southern Alaska Foothills, on the north slope of the Brooks Range, over a 20-year period. Current models and experimental work with tundra vegetation have predicted an increase in shrub species and a decrease in graminoid species as a response to climatic warming. Furthermore, the warming of the Alaskan Arctic during the past 150 years has accelerated over the last three decades and is expected to increase vegetation productivity in tundra if shrubs become more abundant. Decadal change in vegetation in tundra landscapes may be both subtle and slow. Interpreting such change is complicated by spatial variation at small scales and by difficulty in understanding how point changes in species composition relate to landscape-level change in vegetation. Our approach involved resampling the same points in a series of permanent plots over a multi-year interval, using large sample sizes, and analyzing several aspects of compositional change. Our analysis was designed to look at changes in overall species' abundance over time and at relationships between species in terms of the likelihood of one species replacing another. Understanding relationships between species increases the predictive power of measures of species composition and abundance in a time series. We found significant increases in abundance of specific shrub and graminoid species, and a general increase in the extent of the canopy, with a concurrent decrease in the abundance of understory mosses. These changes, extrapolated over the broad expanse of similar vegetation in the Arctic, may have profound above and below ground effects including changes in soil properties, carbon storage and nutrient cycling, and plant community composition.

  15. Coastal circulation and potential coral-larval dispersal in Maunalua Bay, O'ahu, Hawaii—Measurements of waves, currents, temperature, and salinity, June-September 2010

    USGS Publications Warehouse

    Presto, M. Katherine; Storlazzi, Curt D.; Logan, Joshua B.; Reiss, Thomas E.; Rosenberger, Kurt J.

    2012-01-01

    This report presents a summary of fieldwork conducted in Maunalua Bay, O'ahu, Hawaii to address coral-larval dispersal and recruitment from June through September, 2010. The objectives of this study were to understand the temporal and spatial variations in currents, waves, tides, temperature, and salinity in Maunalua Bay during the summer coral-spawning season of Montipora capitata. Short-term vessel surveys and satellite-tracked drifters were deployed to measure currents during the June 2010 spawning event and to supplement the longer-term measurements of currents and water-column properties by fixed, bottom-mounted instruments deployed in Maunalua Bay. These data show that currents at the surface and just below the surface where coral larvae are found are often oriented in opposite directions due primarily to tidal and trade-winds forcing as the primary mechanisms of circulation in the bay. These data extend our understanding of coral-larvae dispersal patterns due to tidal and wind-driven currents and may be applicable to larvae of other Hawaiian corals.

  16. It Happens When We Get There. Conversations With Teachers in Alaskan Villages.

    ERIC Educational Resources Information Center

    Beers, C. David

    Developed through in-depth interviews with experienced "bush" teachers from interior Alaska, this booklet is the product of a five-day workshop in the design of vocational education curriculum materials for rural Alaskan secondary schools. The statements in this booklet represent the edited responses of experienced teachers to the following…

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

    SciTech Connect

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

    1984-01-01

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

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

    USGS Publications Warehouse

    Post, A.S.

    1965-01-01

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

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

    ERIC Educational Resources Information Center

    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…

  20. OMEGA-3 FATTY ACIDS IN SALMON PRESERVED BY NATIVE ALASKAN METHODS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Traditional Native Alaskan diets included salmon as a major source of n-3 long-chain polyunsaturated fatty acids (PUFA). However, in the last 250 years, profound changes have influenced the people of interior Alaska. Departure from ancestral dietary practices has led to a rise in obesity and Type-2 ...

  1. College Orientation Program for Alaskan Natives (COPAN Program - Education for Survival). Final Report.

    ERIC Educational Resources Information Center

    Salisbury, Lee H.

    Of the original number of Alaskan natives entering the University of Alaska from rural and urban areas, 50% drop out at the end of their freshman year, and less than 2% are likely to receive a degree at the end of 4 years. This high attrition rate is caused by poor elementary and secondary school preparation, and strong personal feelings of…

  2. AlaskaAdvantage[R] Programs Annual Report to Alaskans, Year Ending June 30, 2007

    ERIC Educational Resources Information Center

    Alaska Commission on Postsecondary Education, 2007

    2007-01-01

    Through its AlaskAdvantage[R] Programs, the Alaska Commission on Postsecondary Education promotes, supports, and provides access to postsecondary education for Alaskans and in Alaska. This publication reports on another year of success for the state's higher education assistance agency. Among the accomplishments this year to make higher…

  3. Poly(hydroxyalkanoate) Biosynthesis from Crude Alaskan Pollock (Theragra chalcogramma) Oil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Six strains of Pseudomonas were tested for their abilities to synthesize poly(hydroxyalkanoate) (PHA) polymers from crude Pollock oil, a large volume byproduct of the Alaskan fishing industry. All six strains were found to produce PHA polymers from hydrolyzed Pollock oil with productivities (P; the...

  4. Alaska Is Our Home--Book 2: A Natural Science Handbook for Alaskan Students.

    ERIC Educational Resources Information Center

    Bury, John; Bury, Susan

    A natural science resource booklet for teachers and students contains detailed materials for teaching and learning about Alaskan wildlife. Each of nine chapters provides background subject information, suggested learning activities, tear-out pages of review questions for students to answer, and supplementary notes for teachers which include…

  5. 77 FR 45921 - Alaskan Fuel Hauling as a Restricted Category Special Purpose Flight Operation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-02

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

  6. Alaskan Fish Gelatin Films: Thermal, Tensile, and Barrier Properties and Effects of Cross-linking

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gelatin was extracted from the skins of Alaska pollock (Theragra chalcogramma) and Alaska pink salmon (Oncorhynchus gorbuscha). These skins were by-products generated from the Alaskan fishing industry. Films were then cast from the fish gelatin and their thermal, tensile, water vapor permeability, o...

  7. Shaping the Landscape: A Journal of Writing by Alaskan Teachers 1992.

    ERIC Educational Resources Information Center

    Longenbaugh, Betsy, Ed.

    Intended to encourage Alaska teachers to write, to provide an honest sounding board for those submitting work, and to be a pleasure to read, this booklet presents a collection of 20 pieces of writing (short stories, poems, and life experiences) by Alaskan teachers. The pieces and their authors are as follows: "The First Haiku" (Dan Walker);…

  8. Elderly Alaskan Natives in Anchorage: A Needs-Assessment for Social Services Program Planning.

    ERIC Educational Resources Information Center

    Hines, Charles; And Others

    Eighty-five elderly Alaskan Natives living in Anchorage were interviewed to determine if their needs were being met by programs designed for the elderly on a national level. Agencies serving the elderly were also questioned. Age, sex, and ethnic background of the respondents were compared with the variables of degree of education, marital status,…

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

    ERIC Educational Resources Information Center

    Practical Concepts, Inc., Washington, DC.

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

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

    SciTech Connect

    Not Available

    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.

  11. ELECTRIC VEHICLE CONVERSIONS USING ALTERNATIVE ENERGY TO DRIVE ALASKAN RURAL COMMUNITIES

    EPA Science Inventory

    This proposal concerns sustainable transportation in rural Alaskan communities which are not part of a road or electrical network (off grid). In most off-grid communities, the road networks generally are less than 50 square miles, so transportation needs are limited. This limi...

  12. CYCLING OF DISSOLVED ELEMENTAL MERCURY IN ARCTIC ALASKAN LAKES. (R829796)

    EPA Science Inventory

    Aqueous production and water-air exchange of elemental mercury (Hg0) are important features of the environmental cycling of Hg. We investigated Hg0 cycling in ten Arctic Alaskan lakes that spanned a wide range in physicochemical characteristics. Dissolved...

  13. The Change in the Depiction of Alaskan Natives in Children's Fiction over Time.

    ERIC Educational Resources Information Center

    Epps, Dorothy Anne

    This study used content analysis to investigate the change, over time, in the depiction of Alaskan natives in children's fiction. The analysis was based on four broad categories: (1) physical traits, including physical features and types of clothing; (2) social traits, including language fluency, family associations, amount of formal education,…

  14. The nearshore western Beaufort Sea ecosystem: Circulation and importance of terrestrial carbon in arctic coastal food webs

    NASA Astrophysics Data System (ADS)

    Dunton, Kenneth H.; Weingartner, Thomas; Carmack, Eddy C.

    2006-10-01

    The nearshore shelf of the Beaufort Sea is defined by extreme physical and biological gradients that have a distinctive influence on its productivity and trophic structure. Massive freshwater discharge from the Mackenzie River, along with numerous smaller rivers and streams elsewhere along the coast, produce an environment that is decidedly estuarine in character, especially in late spring and summer. Consequently, the Beaufort coast provides a critical habitat for several species of amphidromous fishes, some of which are essential to the subsistence lifestyle of arctic native populations. Because of its low in situ productivity, allochthonous inputs of organic carbon, identifiable on the basis of isotopic composition, are important to the functioning of this arctic estuarine system. Coastal erosion and river discharge are largely responsible for introducing high concentrations of suspended sediment from upland regions into the nearshore zone. The depletion in the 13C content of invertebrate and vertebrate consumers, which drops about 4-5‰ eastward along the eastern Alaskan Beaufort Sea coast, may reflect the assimilation of this terrestrial organic matter into local food webs. In addition, the large range in 13C values of fauna collected in the eastern Beaufort (nearly 8‰) compared to the same species in the northeastern Chukchi (3‰), indicate a lower efficiency of carbon transfer between trophic levels in the eastern Beaufort. The wider spread in stable isotope values in the eastern Beaufort may also reflect a decoupling between benthic and pelagic components. Isotopic tracer studies of amphidromous fishes in the Simpson Island barrier island lagoon revealed that terrestrial (peat) carbon may contribute as much as 30-50% of their total dietary requirements. On the eastern Alaska Beaufort Sea coast, the δ13C values of arctic cod collected in semi-enclosed lagoons were more depleted, by 3-4‰, compared to fish collected in the coastal Beaufort Sea

  15. Linkages between coastal and open-ocean habitats and dynamics of Japanese stocks of chum salmon and Japanese sardine

    NASA Astrophysics Data System (ADS)

    Yatsu, Akihiko; Kaeriyama, Masahide

    2005-03-01

    Coastal-ocean-open-ocean migrations, prey-predator relations and long-term population dynamics of chum salmon ( Oncorhynchus keta) and Japanese sardine ( Sardinops melanostictus), associated with large-scale climate and oceanographic conditions, are reviewed. After early marine life in coastal waters in northern Japan, chum salmon of Japanese origin spend their first summer in the Okhotsk Sea, then move to the Western Subarctic Gyre for the first winter at sea. Thereafter, they migrate between summer feeding grounds in the Bering Sea and wintering grounds in the Alaskan Gyre for a period of usually up to four years, and finally return to their natal rivers to spawn. Carrying capacity ( K) for chum salmon at an unfished equilibrium level was estimated from a Ricker spawner-recruitment curve, and the residual carrying capacity ( RCC=(K-abundance)K-1). was positively correlated with body size at age 4, and negatively correlated with age at maturity. Marine survival of Hokkaido chum populations was affected by body size at release, but neither by Aleutian low pressure activity nor sea-surface temperature (SST) around coastal Hokkaido in spring, although there is some correlation between survival rate and coastal SST. Juveniles of the Pacific stock of Japanese sardine become broadly distributed in the Kuroshio Extension (KE) as far east as 180° longitude during spring. Adults disperse as far as the central Pacific and the southern areas of the Okhotsk Sea and Western Subarctic Gyre in years of high abundance. Somatic growth and age at maturation of sardine are density-dependent. We used catch, biomass and residuals of observed recruitment numbers from a Ricker curve (LNRR) as a measure of sardine population dynamics. LNRR was highly correlated with SST of KE in winter, which shifted in 1970 and 1988. Recent biomass and catch remain at extremely low levels due to a combination of adverse environmental conditions and intensive fishing. We suggest that Japanese

  16. Sulfur dioxide emissions from Alaskan volcanoes quantified using an ultraviolet SO_{2} camera

    NASA Astrophysics Data System (ADS)

    Kern, Christoph; Werner, Cynthia; Kelly, Peter; Brewer, Ian; Ketner, Dane; Paskievitch, John; Power, John

    2016-04-01

    several hundred t/d as well as short-term (<5 min.) variations that could provide insights into shallow degassing mechanisms at this highly active volcanic center. Our presentation will include a brief description of our SO2 camera, a system we designed and built for rapid deployment at active volcanoes, and the results of the measurements will be discussed. These results will be compared to other available monitoring data and interpreted with regard to their importance for assessing the current level of activity of these remote Alaskan volcanoes.

  17. Sinking coastal cities

    NASA Astrophysics Data System (ADS)

    Erkens, G.; Bucx, T.; Dam, R.; de Lange, G.; Lambert, J.

    2015-11-01

    In many coastal and delta cities land subsidence now exceeds absolute sea level rise up to a factor of ten. A major cause for severe land subsidence is excessive groundwater extraction related to rapid urbanization and population growth. Without action, parts of Jakarta, Ho Chi Minh City, Bangkok and numerous other coastal cities will sink below sea level. Land subsidence increases flood vulnerability (frequency, inundation depth and duration of floods), with floods causing major economic damage and loss of lives. In addition, differential land movement causes significant economic losses in the form of structural damage and high maintenance costs for (infra)structure. The total damage worldwide is estimated at billions of dollars annually. As subsidence is often spatially variable and can be caused by multiple processes, an assessment of subsidence in delta cities needs to answer questions such as: what are the main causes? What is the current subsidence rate and what are future scenarios (and interaction with other major environmental issues)? Where are the vulnerable areas? What are the impacts and risks? How can adverse impacts be mitigated or compensated for? Who is involved and responsible to act? In this study a quick-assessment of subsidence is performed on the following mega-cities: Jakarta, Ho Chi Minh City, Dhaka, New Orleans and Bangkok. Results of these case studies will be presented and compared, and a (generic) approach how to deal with subsidence in current and future subsidence-prone areas is provided.

  18. Sinking coastal cities

    NASA Astrophysics Data System (ADS)

    Erkens, Gilles; Bucx, Tom; Dam, Rien; De Lange, Ger; Lambert, John

    2014-05-01

    In many coastal and delta cities land subsidence now exceeds absolute sea level rise up to a factor of ten. Without action, parts of Jakarta, Ho Chi Minh City, Bangkok and numerous other coastal cities will sink below sea level. Land subsidence increases flood vulnerability (frequency, inundation depth and duration of floods), with floods causing major economic damage and loss of lives. In addition, differential land movement causes significant economic losses in the form of structural damage and high maintenance costs. This effects roads and transportation networks, hydraulic infrastructure - such as river embankments, sluice gates, flood barriers and pumping stations -, sewage systems, buildings and foundations. The total damage worldwide is estimated at billions of dollars annually. Excessive groundwater extraction after rapid urbanization and population growth is the main cause of severe land subsidence. In addition, coastal cities are often faced with larger natural subsidence, as they are built on thick sequences of soft soil. Because of ongoing urbanization and population growth in delta areas, in particular in coastal megacities, there is, and will be, more economic development in subsidence-prone areas. The impacts of subsidence are further exacerbated by extreme weather events (short term) and rising sea levels (long term).Consequently, detrimental impacts will increase in the near future, making it necessary to address subsidence related problems now. Subsidence is an issue that involves many policy fields, complex technical aspects and governance embedment. There is a need for an integrated approach in order to manage subsidence and to develop appropriate strategies and measures that are effective and efficient on both the short and long term. Urban (ground)water management, adaptive flood risk management and related spatial planning strategies are just examples of the options available. A major rethink is needed to deal with the 'hidden' but urgent

  19. (abstract) Seasonal Variability in Coastal Upwelling: A Comparison of Four Coastal Upwelling Sites from Space

    NASA Technical Reports Server (NTRS)

    Carr, Mary-Elena

    1996-01-01

    Coastal upwelling of subsurface nutrient-rich water occurs along the eastern boundary of the ocean basins and leads to high primary production and fish catches. In this study satellite observations are used to compare the seasonal cycle in wind forcing and in the oceanic and biological response of the major coastal upwelling regions associated with the Canary, Benguela, California, and Humboldt Currents.

  20. The Coastal Ocean Prediction Systems program: Understanding and managing our coastal ocean

    SciTech Connect

    Eden, H.F.; Mooers, C.N.K.

    1990-06-01

    The goal of COPS is to couple a program of regular observations to numerical models, through techniques of data assimilation, in order to provide a predictive capability for the US coastal ocean including the Great Lakes, estuaries, and the entire Exclusive Economic Zone (EEZ). The objectives of the program include: determining the predictability of the coastal ocean and the processes that govern the predictability; developing efficient prediction systems for the coastal ocean based on the assimilation of real-time observations into numerical models; and coupling the predictive systems for the physical behavior of the coastal ocean to predictive systems for biological, chemical, and geological processes to achieve an interdisciplinary capability. COPS will provide the basis for effective monitoring and prediction of coastal ocean conditions by optimizing the use of increased scientific understanding, improved observations, advanced computer models, and computer graphics to make the best possible estimates of sea level, currents, temperatures, salinities, and other properties of entire coastal regions.

  1. Population Connectivity and Phylogeography of a Coastal Fish, Atractoscion aequidens (Sciaenidae), across the Benguela Current Region: Evidence of an Ancient Vicariant Event

    PubMed Central

    Henriques, Romina; Potts, Warren M.; Santos, Carmen V.; Sauer, Warwick H. H.; Shaw, Paul W.

    2014-01-01

    Contemporary patterns of genetic diversity and population connectivity within species can be influenced by both historical and contemporary barriers to gene flow. In the marine environment, present day oceanographic features such as currents, fronts and upwelling systems can influence dispersal of eggs/larvae and/juveniles/adults, shaping population substructuring. The Benguela Current system in the southeastern Atlantic is one of the oldest upwelling systems in the world, and provides a unique opportunity to investigate the relative influence of contemporary and historical mechanisms shaping the evolutionary history of warm-temperate fish species. Using the genetic variation in the mitochondrial DNA Control Region and eight nuclear microsatellite DNA loci, we identified the presence of two highly divergent populations in a vagile and warm-temperate fish species, Atractoscion aequidens, across the Benguela region. The geographical distributions of the two populations, on either side of the perennial upwelling cell, suggest a strong correlation between the oceanographic features of the system and the breakdown of gene flow within this species. Genetic divergence (mtDNA φST = 0.902, microsatellite FST = 0.055: probability of genetic homogeneity for either marker = p<0.001), absence of migrants (less than 1% per generation) between populations and coalescent estimates of time since most recent common ancestor suggest that the establishment of the main oceanographic features of the system (2 million years ago), particularly the strengthening and position of the perennial upwelling cell, is the most likely mechanism behind the observed isolation. Concordance between mitochondrial and nuclear genetic markers indicates that isolation and divergence of the northern and southern Benguela populations of A. aequidens occurred deep in the past and has continued to the present day. These findings suggest that the Benguela Current system may constitute an ancient

  2. Shifting paradigms in coastal restoration: Six decades' lessons from China.

    PubMed

    Liu, Zezheng; Cui, Baoshan; He, Qiang

    2016-10-01

    With accelerating degradation of coastal environment worldwide, restoration has been elevated as a global strategy to enhance the functioning and social services of coastal ecosystems. While many developing countries suffer from intense coastal degradation, current understanding of the science and practice of their coastal restorations is extremely limited. Based on analysis of >1000 restoration projects, we provide the first synthesis of China's coastal restorations. We show that China's coastal restoration has recently entered a rapidly developing stage, with an increasing number of restoration projects carried out in multiple types of coastal ecosystems. While long-term, national-level restorations enforced by the government appear promising for some coastal ecosystems, especially mangroves, restorations of many other coastal ecosystems, such as salt marshes, seagrasses and coral reefs, have been much less implemented, likely due to under-appreciation of their ecosystem services values. Furthermore, the planning, techniques, research/assessment, and participation models underlying current restorations remain largely inadequate for restoration to effectively halt rapid coastal degradation. To promote success, we propose a framework where paradigms in current restorations from planning to implementation and assessment are transformed in multiple ways. Our study has broad implications for coastal environmental management policies and practices, and should inform sustainable development of coupled human-ocean systems in many countries. PMID:27220097

  3. Rheological conditions for emplacement of Ural-Alaskan-type ultramafic complexes

    NASA Astrophysics Data System (ADS)

    Guillou-Frottier, Laurent; Burov, Evgueni; Augé, Thierry; Gloaguen, Eric

    2014-09-01

    Ural-Alaskan- (or Alaskan-) type complexes correspond to a particular class of ultramafic intrusions that attract particular attention due to their deep mantle origin and their platinum-group element (PGE) mineralization. When defined as massifs of dunite-clinopyroxenite, only forty-six complexes are reported in the literature. These large-scale dunite pipe-like structures are rarely isolated and they even can appear in clusters. To better understand genesis of these relatively young (< 460 Ma) complexes, a worldwide compilation has been built, and three categories have been defined: single circular or elliptical bodies, twin bodies with similar shapes, and dismembered dunite bodies. PGE enrichment in Alaskan-type complexes is highest for the second category, where twin bodies are interpreted as horizontal sections of Y-shaped dunite pipes. To constrain mechanical properties of the lithosphere allowing emplacement of the Alaskan-type complexes, the forceful diapiric ascent hypothesis is investigated through numerical thermo-mechanical models. One hundred high resolution experiments accounting for realistic phase changes and softening mechanisms have been performed. The experiments show that with no rheological softening of the host rock and in case of a relatively weak ductile lower crust, the uprising magma tends to spread laterally without reaching the surface. To account for the forceful ascent of deep magmas, it is hence necessary to assume a strong lower crust rheology and strong local softening mechanisms. Besides reproducing the clustered distribution of the weakness zones representing magma pathways, these latter experiments reproduce large-scale pipe-like (cylindrical) structures, Y-shaped and funnel-shaped bodies, and laterally-shifted structures. Interestingly, zones of highest strain rates are located at the bottom parts of the inclined edges of Y-shaped and funnel-shaped bodies. The restricted age range of Alaskan-type complexes (< 460 Ma) would mean

  4. Development of perspective methods for modeling 3D currents for coastal systems in connection with environmental problems in South of France as well as South of Russia

    NASA Astrophysics Data System (ADS)

    Alexeenko, Elena; Sukhinov, Alexander; Roux, Bernard; Meule, Samuel; Chistyakov, Alexander

    2010-05-01

    Shallow water reservoirs are complex multi-parameter hydrodynamic systems. The current and the coupled processes occurring in them are spatially three-dimensional and unsteady, and have essentially nonlinear character. Therefore, the use of field experiments to analyse such a systems is extremely labor intensive and costly. Without underestimating the role of field experiments, it should be nevertheless noted that the most optimal in terms of cost and reliability of the results is an approach based on a combination of relatively inexpensive and safe field experiments and mathematical modeling of the processes under study. The present approach has several advantages with respect to the existing models. Three components of velocity vector from the full system of Navier-Stokes equations (and not on the basis of the hydrostatic approximation) and the equation of the surface elevation are calculated. In most hydrodynamic models of shallow water, the third component of the velocity vector is determined from the equations of continuity and the elevation surface level, which introduces significant error in the determination of the component. Calculation of the three components of velocity vector based on the equations of motion is a time-consuming process, so the hydrostatic approximation is used as an initial approximation for calculating the pressure. This approach greatly reduces the computing time and the costs. Also one of the advantages of the present model is an improved parameterization of the vertical turbulent exchange coefficient, on the basis of ADCP measurement data (Acoustic Doppler Current Profiler). In modern numerical models of vertical turbulent exchange, this coefficient often appears as a fitting parameter. Among the numerous approximations of the coefficient of vertical turbulent exchange, the algebraic subgrid model of Belotcerkovskii, which is based on the determination of turbulent flows as multiplications of averaged over time (correlation

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

    PubMed

    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. PMID:26151232

  6. Repertoire and classification of non-song calls in Southeast Alaskan humpback whales (Megaptera novaeangliae).

    PubMed

    Fournet, Michelle E; Szabo, Andy; Mellinger, David K

    2015-01-01

    On low-latitude breeding grounds, humpback whales produce complex and highly stereotyped songs as well as a range of non-song sounds associated with breeding behaviors. While on their Southeast Alaskan foraging grounds, humpback whales produce a range of previously unclassified non-song vocalizations. This study investigates the vocal repertoire of Southeast Alaskan humpback whales from a sample of 299 non-song vocalizations collected over a 3-month period on foraging grounds in Frederick Sound, Southeast Alaska. Three classification systems were used, including aural spectrogram analysis, statistical cluster analysis, and discriminant function analysis, to describe and classify vocalizations. A hierarchical acoustic structure was identified; vocalizations were classified into 16 individual call types nested within four vocal classes. The combined classification method shows promise for identifying variability in call stereotypy between vocal groupings and is recommended for future classification of broad vocal repertoires. PMID:25618033

  7. REPETITIVE DIGITAL NOAA-AVHRR DATA FOR ALASKAN ENGINEERING AND SCIENTIFIC APPLICATIONS.

    USGS Publications Warehouse

    Christie, William M.; Pawlowski, Robert J.; Fleming, Michael D.

    1986-01-01

    Selected digitally enhanced NOAA - Advanced Very High Resolution Radiometer (AVHRR) images taken by the NOAA 6, 7, 8 and 9 Polar Orbiting Satellites demonstrate the capability and application of repetitive low-resolution satellite data to Alaska's engineering and science community. Selected cloud-free visible and thermal infrared images are enhanced to depict distinct oceanographic and geologic processes along Alaska's west coast and adjacent seas. Included are the advance of the Bering Sea ice field, transport of Yukon River sediment into Norton Sound, and monitoring of plume trajectories from the Mount Augustine volcanic eruptions. Presented illustrations are representative of the 94 scenes in a cooperative USGS EROS/NOAA Alaskan AVHRR Digital Archive. This paper will discuss the cooperative efforts in establishing the first year data set and identifying Alaskan applications.

  8. Preliminary evidence for the involvement of budding bacteria in the origin of Alaskan placer gold

    USGS Publications Warehouse

    Watterson, J.R.

    1992-01-01

    Lacelike networks of micrometre-size filiform gold associated wtih Alaskan placer gold particles are interpreted as low-temperature pseudomorphs of a Pedomicrobium-like budding bacterium. Submicron reproductive structures (hyphae) and other morphological features similar to those of Pedomicrobium manganicum occur as detailed three-dimensional facsimiles in high purity gold in and on placer gold particles from Lillian Creek, Alaska. In a scanning electron microscope survey, the majority of gold particles at nine Alaskan placer deposits appear to include gold that has accumulated chemically at low temperatures in and on the cells of P. manganicum. Similar bacterioform gold from a Paleozoic deposit in China and from the Precambrian Witwatersrand deposit in South Africa may indicate that bacterioform gold is widespread. -Author

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

    USGS Publications Warehouse

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

    2003-01-01

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

  10. Coastal-ocean uptake of anthropogenic carbon

    NASA Astrophysics Data System (ADS)

    Bourgeois, Timothée; Orr, James C.; Resplandy, Laure; Terhaar, Jens; Ethé, Christian; Gehlen, Marion; Bopp, Laurent

    2016-07-01

    Anthropogenic changes in atmosphere-ocean and atmosphere-land CO2 fluxes have been quantified extensively, but few studies have addressed the connection between land and ocean. In this transition zone, the coastal ocean, spatial and temporal data coverage is inadequate to assess its global budget. Thus we use a global ocean biogeochemical model to assess the coastal ocean's global inventory of anthropogenic CO2 and its spatial variability. We used an intermediate resolution, eddying version of the NEMO-PISCES model (ORCA05), varying from 20 to 50 km horizontally, i.e. coarse enough to allow multiple century-scale simulations but finer than coarse-resolution models (˜ 200 km) to better resolve coastal bathymetry and complex coastal currents. Here we define the coastal zone as the continental shelf area, excluding the proximal zone. Evaluation of the simulated air-sea fluxes of total CO2 for 45 coastal regions gave a correlation coefficient R of 0.8 when compared to observation-based estimates. Simulated global uptake of anthropogenic carbon results averaged 2.3 Pg C yr-1 during the years 1993-2012, consistent with previous estimates. Yet only 0.1 Pg C yr-1 of that is absorbed by the global coastal ocean. That represents 4.5 % of the anthropogenic carbon uptake of the global ocean, less than the 7.5 % proportion of coastal-to-global-ocean surface areas. Coastal uptake is weakened due to a bottleneck in offshore transport, which is inadequate to reduce the mean anthropogenic carbon concentration of coastal waters to the mean level found in the open-ocean mixed layer.

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

    SciTech Connect

    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.

  12. Sinking Coastal Cities

    NASA Astrophysics Data System (ADS)

    Erkens, G.; Stuurman, R.; De Lange, G.; Bucx, T.; Lambert, J.

    2014-12-01

    In many coastal cities land subsidence now exceeds absolute sea level rise up to a factor of ten. Without action, parts of Jakarta, Ho Chi Minh City, Bangkok and numerous other coastal cities will continue to sink, even below sea level. The ever increasing industrial and domestic demand for water in these cities results in excessive groundwater extraction, causing severe subsidence. In addition, coastal cities are often faced with larger natural subsidence, as they are built on thick sequences of soft soil. The impacts of subsidence are further exacerbated by climate-induced sea level rise. Land subsidence results in two types damage: foremost it increases flood vulnerability (frequency, inundation depth and duration of floods), with floods causing major economic damage and loss of lives. Secondly, differential land movement causes significant economic losses in the form of structural damage and high maintenance costs of roads and transportation networks, sewage systems, buildings and foundations. The total damage worldwide is estimated at billions of dollars annually. To survey the extent of groundwater associated subsidence, we conducted a quick-assessment of subsidence in a series of mega-cities (Jakarta, Ho Chi Minh City, Dhaka, New Orleans and Bangkok). For each city research questions included: what are the main causes, how much is the current subsidence rate and what are predictions, where are the vulnerable areas, what are the impacts and risks, how can adverse impacts can be mitigated or compensated for, and what governmental bodies are involved and responsible to act? Using the assessment, this paper discusses subsidence modelling and measurement results from the selected cities. The focus is on the importance of delayed settlement after increases in hydraulic heads, the role of the subsurface composition for subsidence rates and best practice solutions for subsiding cities. For the latter, urban (ground)water management, adaptive flood risk management

  13. Scenario Planning for Coastal Adaptation

    NASA Astrophysics Data System (ADS)

    Parris, A.; Obeysekera, J.; Knuuti, K.; Moss, R. H.; Horton, R. M.; Weiss, J. L.

    2012-12-01

    Sea level rise (SLR) is a persistent environmental change observed globally for more than a century, and its expected continuation poses significant challenges to the United States (US). We summarize a process associated with the United States National Climate Assessment for identifying four scenarios of global mean sea level rise (SLR). The main finding is that global mean sea level is expected to rise no less than 0.2 meters and no more than 2.0 meters by the end of the century. Recent publications suggest that a 4 C world would result in global mean SLR towards the upper end of that range. Aside from this process, there is currently no coordinated, interagency effort in the US to identify agreed upon global mean sea level rise projections for the purpose of coastal planning, policy, and management. This is an important gap because identifying global mean SLR estimates is a critical step in assessing coastal impacts and vulnerabilities. At present, coastal managers are left to identify global SLR estimates through their own interpretation of the scientific literature or the advice of experts on an ad-hoc basis. Yet, relative SLR at over one hundred tide gages (~80%) along the US coast reflect the global trend (1.7 - 3.2 mm/yr). No widely accepted method is currently available for producing probabilistic projections of SLR at actionable scales (i.e., regional to local). The desire to have a most probable or likely outcome can lead to paralysis or inaction for coastal decision-making. Given the range of uncertainty in future global SLR, scenario planning offers an opportunity to overcome decision-making paralysis and initiate actions now that may reduce future impacts and vulnerabilities. Scenarios do not predict future changes, but describe future potential conditions in a manner that supports decision-making under uncertainty. Using multiple scenarios, none more likely than the other, encourages experts and decision makers to rehearse multiple, plausible futures

  14. Climate Change and Coastal Eutrophication

    NASA Astrophysics Data System (ADS)

    Rabalais, N. N.

    2014-12-01

    The world's climate has changed and human activities will continue to contribute to the acceleration of greenhouse gases and temperature rise. The major drivers of these changes are increased temperature, altered hydrological cycles and shifts in wind patterns that might alter coastal currents. Increasing temperatures alone have the potential to strengthen pycnoclines in estuarine and coastal waters, but lower surface salinity (e.g., from increased freshwater runoff) would be more of a factor in stratifying the water column. The combination of increased nutrient loads (from human activities) and increased freshwater discharge (from GCC) will aggravate the already high loads of nutrients from the Mississippi River to the northern Gulf of Mexico, strengthen stratification (all other factors remaining the same), and worsen the hypoxia situation. Reduced precipitation, on the other hand, would lower the amount of nutrients and water reaching the coastal zone and, perhaps, lead to oligotrophication and reduced fisheries productivity, or perhaps alleviate hypoxia. The increase or decrease in flow (whichever occurs), flux of nutrients and water temperature are likely to have important, but as yet not clearly identifiable, influences on hypoxia. In anticipation of the negative effects of global change, nutrient loadings to coastal waters need to be reduced now, so that further water quality degradation is prevented.

  15. Seasonal to interannual variability of the Pacific water boundary current in the Beaufort Sea

    NASA Astrophysics Data System (ADS)

    Brugler, Eric T.; Pickart, Robert S.; Moore, G. W. K.; Roberts, Steven; Weingartner, Thomas J.; Statscewich, Hank

    2014-09-01

    Between 2002 and 2011 a single mooring was maintained at the core of the Pacific water boundary current in the Beaufort Sea, approximately 150 km east of Pt. Barrow, Alaska. Using velocity and hydrographic data from six year-long deployments, we examine the variability of the current on seasonal to interannual timescales. The seasonal signal is characterized by enhanced values of volume, heat, and freshwater transport during the summer months associated with the presence of two summertime Pacific water masses, Alaskan Coastal Water and Chukchi Summer Water. Strikingly, over the decade the volume transport of the current has decreased by more than 80%, with comparable reductions in the heat and freshwater transports, despite the fact that the flow through Bering Strait has increased over this time period. The largest changes in the boundary current have occurred in the summer months. Using atmospheric reanalysis fields and weather station data, we demonstrate that an increase in summer easterly winds along the Beaufort slope is the primary cause for the reduction in transport. The stronger winds are due to an intensification of the summer Beaufort High and deepening of the summer Aleutian Low. Using additional mooring and shipboard data in conjunction with satellite fields, we investigate the implications of the reduction in transport of the boundary current. We argue that a significant portion of the mass and heat passing through Bering Strait in recent years has been advected out of Barrow Canyon into the interior Canada Basin - rather than entering the boundary current in the Beaufort Sea - where it is responsible for a significant portion of the increased sea ice melt in the basin.

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

    USGS Publications Warehouse

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

    2002-01-01

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

  17. Using Tree Rings, CO2 Fluxes, and Long-Term Measurements to Understand Carbon Dynamics in an Alaskan Boreal Forest

    NASA Astrophysics Data System (ADS)

    Bond-Lamberty, B. P.; Anderson, C.; Crump, A.; Stegen, J.

    2015-12-01

    Decadal and centennial processes are usually poorly constrained by data, but many opportunities exist to combine disparate data sources such as tree rings, greenhouse gas fluxes from the soil to atmosphere, and long-term tree inventories. At high northern latitudes, permafrost (and its current degradation across large scales) is presumed to exert a strong control on long-term ecosystem carbon uptake and storage. We integrate a variety of data from both Canada and Alaska, focusing on two years of observations across a permafrost gradient in a black spruce Alaskan watershed (the Caribou/Poker Creek Research Watershed ~50 km northeast of Fairbanks, AK, USA). Permafrost depth changes were strongly associated with changes in vegetation and leaf morphology, as well as soil greenhouse fluxes (0.1-2.0 μmol/m2/s, with strong spatial dependencies) and aboveground net primary production (60-550 gC/m2/yr). We use tree-ring data covering the last century to examine how tree response to climate variability changes with elevation and permafrost depth, both along small-scale transects and across the entire 104 km2 watershed. A weakness is that these results are from a single site and point in successional time; we quantify potential variability in this area using 16 years of observations from a Canadian boreal chronosequence. We emphasize that both short and long term observations and experiments, using multiple approaches, are necessary to constrain ecosystem carbon uptake and storage.

  18. Community-scale Coastal Vulnerability Mapping in Alaska: Status and Needs

    NASA Astrophysics Data System (ADS)

    Kinsman, N.; Gould, A.

    2014-12-01

    Alaska's extensive shorelines are incompletely mapped and under-instrumented to proceed with widespread assessments of coastal vulnerability. Despite this baseline data shortage, many of Alaska's coastal communities are involved in mitigation or adaptation efforts in response to natural hazards such as erosion and flooding. To provide coastal communities with the tools that are necessary to support local decision-making, the Alaska Division of Geological & Geophysical Surveys (DGGS) has undertaken focused field studies to improve quality, quantity and access to coastal datasets such as topography, nearshore bathymetry, rates of shoreline change and relevant water levels. These efforts are inclusive of both standard approaches (e.g. lidar, repeat coastal profile measurements, Digital Shoreline Analysis System assessments and fully-instrumented tide stations) as well as alternative methodologies that improve our ability to economically accomplish this work in harsh, remote areas (e.g. Structure From Motion surface models, quantification of local knowledge observations, stop-gap tidal datum conversion tools, and pressure-sensor water level networks). We present a comprehensive summary of the geographic variability of coastal dynamics and geohazard potential along the Alaska shoreline, from the erosion-prone North Slope coastline to low-lying areas in western Alaska that are at elevated risk to storm surge inundation. This work provides a graphical summary of the existing quality and spatial extent of data in Alaskan coastal communities while highlighting critical data gaps, such as high-precision elevation models, which are delaying more robust flood and erosion vulnerability mapping. By outlining ongoing work and providing examples from recent DGGS projects we will showcase some of the new vulnerability mapping tools under development for our state and also identify opportunities for necessary collaborations in the Alaska coastal zone.

  19. Stable lead isotopes evidence anthropogenic contamination in Alaskan sea otters

    SciTech Connect

    Smith, D.R.; Estes, J.A.; Flegal, A.R. ); Niemeyer, S. )

    1990-10-01

    Lead concentrations and stable isotopic compositions were measured in teeth of preindustrial and contemporary sea otters (Enhydra lutris) from Amchitka Island, AK, to determine if changes had occurred in the magnitude and source of assimilated lead. Although there was no significant difference in lead concentrations between the two groups of otters ({bar x} {plus minus} {sigma}Pb/Ca atomic = 3.6 {plus minus} 2.9 {times} 10{sup {minus}8}), differences in stable lead isotopic compositions revealed a pronounced change in the source of accumulated lead. Lead {bar x} {plus minus} 2{sigma}{sub {bar x}} in the preindustrial otters ({sup 207}Pb/{sup 206}Pb = 0.828 {plus minus} 0.006) was derived from natural deposits in the Aleutian arc, while lead in the contemporary animals ({sup 207}Pb/{sup 206}Pb = 0.856 {plus minus} 0.003) was primarily industrial lead from Asia and western Canada. The isotopic ratios demonstrate anthropogenic perturbations of the lead cycle in present-day coastal food webs and indicate that lead concentration measurements alone are inadequate in assessing the introduction and transport of contaminant lead in the environment.

  20. The Arctic Circumpolar Boundary Current

    NASA Astrophysics Data System (ADS)

    Aksenov, Yevgeny; Ivanov, Vladimir V.; Nurser, A. J. George; Bacon, Sheldon; Polyakov, Igor V.; Coward, Andrew C.; Naveira-Garabato, Alberto C.; Beszczynska-Moeller, Agnieszka

    2011-09-01

    We present high-resolution simulations and observational data as evidence of a fast current flowing along the shelf break of the Siberian and Alaskan shelves in the Arctic Ocean. Thus far, the Arctic Circumpolar Boundary Current (ACBC) has been seen as comprising two branches: the Fram Strait and Barents Sea Branches (FSB and BSB, respectively). Here we describe a new third branch, the Arctic Shelf Break Branch (ASBB). We show that the forcing mechanism for the ASBB is a combination of buoyancy loss and non-local wind, creating high pressure upstream in the Barents Sea. The potential vorticity influx through the St. Anna Trough dictates the cyclonic direction of flow of the ASBB, which is the most energetic large-scale circulation structure in the Arctic Ocean. It plays a substantial role in transporting Arctic halocline waters and exhibits a robust seasonal cycle with a summer minimum and winter maximum. The simulations show the continuity of the FSB all the way around the Arctic shelves and the uninterrupted ASBB between the St. Anna Trough and the western Fram Strait. The BSB flows continuously along the Siberian shelf as far as the Chukchi Plateau, where it partly diverges from the continental slope into the ocean interior. The Alaskan Shelf break Current (ASC) is the analog of the ASBB in the Canadian Arctic. The ASC is forced by the local winds and high upstream pressure in Bering Strait, caused by the drop in sea surface height between the Pacific and Arctic Oceans.

  1. Do ENSO and Coastal Development Enhance Coastal Burial of Terrestrial Carbon?

    PubMed

    Macreadie, Peter I; Rolph, Timothy C; Boyd, Ron; Schröder-Adams, Claudia J; Skilbeck, Charles G

    2015-01-01

    Carbon cycling on the east coast of Australia has the potential to be strongly affected by El Niño-Southern Oscillation (ENSO) intensification and coastal development (industrialization and urbanization). We performed paleoreconstructions of estuarine sediments from a seagrass-dominated estuary on the east coast of Australia (Tuggerah Lake, New South Wales) to test the hypothesis that millennial-scale ENSO intensification and European settlement in Australia have increased the transfer of organic carbon from land into coastal waters. Our data show that carbon accumulation rates within coastal sediments increased significantly during periods of maximum millennial-scale ENSO intensity ("super-ENSO") and coastal development. We suggest that ENSO and coastal development destabilize and liberate terrestrial soil carbon, which, during rainfall events (e.g., La Niña), washes into estuaries and becomes trapped and buried by coastal vegetation (seagrass in this case). Indeed, periods of high carbon burial were generally characterized as having rapid sedimentation rates, higher content of fine-grained sediments, and increased content of wood and charcoal fragments. These results, though preliminary, suggest that coastal development and ENSO intensification--both of which are predicted to increase over the coming century--can enhance capture and burial of terrestrial carbon by coastal ecosystems. These findings have important relevance for current efforts to build an understanding of terrestrial-marine carbon connectivity into global carbon budgets. PMID:26691557

  2. Do ENSO and Coastal Development Enhance Coastal Burial of Terrestrial Carbon?

    PubMed Central

    Macreadie, Peter I.; Rolph, Timothy C.; Boyd, Ron; Schröder-Adams, Claudia J.; Skilbeck, Charles G.

    2015-01-01

    Carbon cycling on the east coast of Australia has the potential to be strongly affected by El Niño-Southern Oscillation (ENSO) intensification and coastal development (industrialization and urbanization). We performed paleoreconstructions of estuarine sediments from a seagrass-dominated estuary on the east coast of Australia (Tuggerah Lake, New South Wales) to test the hypothesis that millennial-scale ENSO intensification and European settlement in Australia have increased the transfer of organic carbon from land into coastal waters. Our data show that carbon accumulation rates within coastal sediments increased significantly during periods of maximum millennial-scale ENSO intensity (“super-ENSO”) and coastal development. We suggest that ENSO and coastal development destabilize and liberate terrestrial soil carbon, which, during rainfall events (e.g., La Niña), washes into estuaries and becomes trapped and buried by coastal vegetation (seagrass in this case). Indeed, periods of high carbon burial were generally characterized as having rapid sedimentation rates, higher content of fine-grained sediments, and increased content of wood and charcoal fragments. These results, though preliminary, suggest that coastal development and ENSO intensification—both of which are predicted to increase over the coming century—can enhance capture and burial of terrestrial carbon by coastal ecosystems. These findings have important relevance for current efforts to build an understanding of terrestrial-marine carbon connectivity into global carbon budgets. PMID:26691557

  3. 33 CFR 334.1280 - Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 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....

  4. 33 CFR 334.1280 - Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 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....

  5. 33 CFR 334.1280 - Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 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....

  6. 33 CFR 334.1280 - Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 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....

  7. 33 CFR 334.1300 - Blying Sound area, Gulf of Alaska, Alaska; air-to-air gunnery practice area, Alaskan Air Command...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., Alaska; air-to-air gunnery practice area, Alaskan Air Command, U.S. Air Force. 334.1300 Section 334.1300... gunnery practice area, Alaskan Air Command, U.S. Air Force. (a) The danger zone. A rhomboidal area... Air Command, U.S. Air Force, Anchorage, Alaska, or such agencies as he may designate. (Sec. 7, 40...

  8. 33 CFR 334.1300 - Blying Sound area, Gulf of Alaska, Alaska; air-to-air gunnery practice area, Alaskan Air Command...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., Alaska; air-to-air gunnery practice area, Alaskan Air Command, U.S. Air Force. 334.1300 Section 334.1300... gunnery practice area, Alaskan Air Command, U.S. Air Force. (a) The danger zone. A rhomboidal area... Air Command, U.S. Air Force, Anchorage, Alaska, or such agencies as he may designate. (Sec. 7, 40...

  9. 33 CFR 334.1300 - Blying Sound area, Gulf of Alaska, Alaska; air-to-air gunnery practice area, Alaskan Air Command...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., Alaska; air-to-air gunnery practice area, Alaskan Air Command, U.S. Air Force. 334.1300 Section 334.1300... gunnery practice area, Alaskan Air Command, U.S. Air Force. (a) The danger zone. A rhomboidal area... Air Command, U.S. Air Force, Anchorage, Alaska, or such agencies as he may designate. (Sec. 7, 40...

  10. 33 CFR 334.1300 - Blying Sound area, Gulf of Alaska, Alaska; air-to-air gunnery practice area, Alaskan Air Command...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., Alaska; air-to-air gunnery practice area, Alaskan Air Command, U.S. Air Force. 334.1300 Section 334.1300... gunnery practice area, Alaskan Air Command, U.S. Air Force. (a) The danger zone. A rhomboidal area... Air Command, U.S. Air Force, Anchorage, Alaska, or such agencies as he may designate. (Sec. 7, 40...

  11. 33 CFR 334.1300 - Blying Sound area, Gulf of Alaska, Alaska; air-to-air gunnery practice area, Alaskan Air Command...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., Alaska; air-to-air gunnery practice area, Alaskan Air Command, U.S. Air Force. 334.1300 Section 334.1300... gunnery practice area, Alaskan Air Command, U.S. Air Force. (a) The danger zone. A rhomboidal area... Air Command, U.S. Air Force, Anchorage, Alaska, or such agencies as he may designate. (Sec. 7, 40...

  12. 33 CFR 334.1280 - Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force.

    Code of Federal Regulations, 2010 CFR

    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....

  13. Coastal erosion problem, modelling and protection

    NASA Astrophysics Data System (ADS)

    Yılmaz, Nihal; Balas, Lale; İnan, Asu

    2015-09-01

    Göksu Delta, located in the south of Silifke County of Mersin on the coastal plain formed by Göksu River, is one of the Specially Protected Areas in Turkey. Along the coastal area of the Delta, coastline changes at significant rates are observed, concentrating especially at four regions; headland of İncekum, coast of Paradeniz Lagoon, river mouth of Göksu and coast of Altınkum. The coast of Paradeniz Lagoon is suffering significantly from erosion and the consequent coastal retreating problem. Therefore, the narrow barrier beach which separates Paradeniz Lagoon from the Mediterranean Sea is getting narrower, creating a risk of uniting with the sea, thus causing the disappearance of the Lagoon. The aim of this study was to understand the coastal transport processes along the coastal area of Göksu Delta to determine the coastal sediment transport rates, and accordingly, to propose solutions to prevent the loss of coastal lands in the Delta. To this end, field measurements of currents and sediment grain sizes were carried out, and wind climate, wave climate, circulation patterns and longshore sediment transport rates were numerically modeled by HYDROTAM-3D, which is a three dimensional hydrodynamic transport model. Finally, considering its special importance as an environmentally protected region, some coastal structures of gabions were proposed as solutions against the coastal erosion problems of the Delta. The effects of proposed structures on future coastline changes were also modeled, and the coastlines predicted for the year 2017 are presented and discussed in the paper.

  14. Alaska Humans Factors Safety Study: The Southern Coastal Area

    NASA Technical Reports Server (NTRS)

    Chappell, Sheryl L.; Reynard, William (Technical Monitor)

    1995-01-01

    At the request of the Alaska Air Carriers Association, researchers from the NASA Aviation Safety Reporting System, at NASA Ames Research Center, conducted a study on aspects of safety in Alaskan Part 135 air taxi operations. An interview form on human factors safety issues was created by a representative team from the FAA-Alaska, NTSB-Alaska, NASA-ASRS, and representatives of the Alaska Air Carriers Association which was subsequently used in the interviews of pilots and managers. Because of the climate and operational differences, the study was broken into two geographical areas, the southern coastal areas and the northern portion of the state. This presentation addresses the southern coastal areas, specifically: Anchorage, Dillingham, King Salmon, Kodiak, Cold Bay, Juneau, and Ketchikan. The interview questions dealt with many of the potential pressures on pilots and managers associated with the daily air taxi operations in Alaska. The impact of the environmental factors such as the lack of available communication, navigation and weather information systems was evaluated. The results of this study will be used by government and industry working in Alaska. These findings will contribute important information on specific Alaska safety issues for eventual incorporation into training materials and policies that will help to assure the safe conduct of air taxi flights in Alaska.

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  16. Emissions of biogenic sulfur gases from Alaskan tundra

    SciTech Connect

    Hines, M.E.; Morrison, M.C.

    1992-10-30

    Fluxes of the biogenic sulfur gases carbonyl sulfide (COS), dimethyl sulfide (DMS), methyl mercaptan (MeSH), and carbon disulfide (CS{sub 2}) were determined from several freshwater and coastal marine tundra habitats using a dynamic enclosure method and gas chromatography. In the freshwater tundra sites, highest emissions, with a mean of 6.0 nmol m{sup {minus}2}h{sup {minus}1} (1.5-10) occurred in the water-saturated wet meadow areas inhabited by grasses, sedges, and Shpagnum mosses. In the drier upland tundra sites, highest fluxes occurred in areas inhabited by mixed vegetation and labrador tea at 3.0 nmol m{sup {minus}2}h{sup {minus}1} (0-8.3) and lowest fluxes were from lichen-dominated areas at 0.8 nmol m{sup {minus}2}h{sup {minus}1}. Sulfur emissions from a lake surface were also low at 0.8 nmol m{sup {minus}2}h{sup {minus}1}. Of the compounds measured, DMS was the dominant gas emitted from all of these sites. Sulfur emissions from the marine sites were up to 20-fold greater than fluxes in the freshwater habitats and were also dominated by DMS. Emissions of DMS were highest from intertidal soils inhabited by Carex subspathacea. This Carex sp. was grazed thoroughly by geese and DMS fluxes doubled when goose feces were left within the flux chamber. Emissions were much lower from other types of vegetation which were more spatially dominant. Sulfur emissions from tundra were among the lowest reported in the literature. When emission data were extrapolated to include all tundra globally, the global flux of biogenic sulfur from this biome is 2-3 x 10{sup 8} g yr{sup {minus}1}. This represents less than 0.001% of the estimated annual global flux of biogenic sulfur and <0.01% of the estimated terrestrial flux. The low emissions are attributed to the low availability of sulfate, certain hydrological characteristics of tundra, and the tendency for tundra to accumulate organic matter. 31 refs., 1 fig., 2 tabs.

  17. Emissions of biogenic sulfur gases from Alaskan tundra

    NASA Technical Reports Server (NTRS)

    Hines, Mark E.; Morrison, Michael C.

    1992-01-01

    Fluxes of the biogenic sulfur gases carbonyl sulfide (COS), dimethyl sulfide (DMS), methyl mercaptan (MeSH), and carbon disulfide (CS2) were determined for several freshwater and coastal marine tundra habitats using a dynamic enclosure method and gas chromatography. In the freshwater tundra sites, highest emissions, with a mean of 6.0 nmol/m(sup -2)H(sup -1) (1.5-10) occurred in the water-saturated wet meadow areas inhabited by grasses, sedges, and Sphagnum mosses. In the drier upland tundra sites, highest fluxes occurred in areas inhabited by mixed vegetation and labrador tea at 3.0 nmol/m(sup -2)h(sup -1) (0-8.3) and lowest fluxes were from lichen-dominated areas at 0.9 nmol/m(sup -2)h(sup -1). Sulfur emissions from a lake surface were also low at 0.8 nmol/m(sup -2)h(sup -1). Of the compounds measured, DMS was the dominant gas emitted from all of these sites. Sulfure emissions from the marine sites were up to 20-fold greater than fluxes in the freshwater habitats and were also dominated by DMS. Emissions of DMS were highest from intertidal soils inhabited by Carex subspathacea (150-250 nmol/m(sup -2)h(sup -1)). This Carex sp. was grazed thoroughly by geese and DMS fluxes doubled when goose feces were left within the flux chamber. Emissions were much lower from other types of vegetation which were more spatially dominant. Sulfure emissions from tundra were among the lowest reported in the literature. When emission data were extrapolated to include all tundra globally, the global flux of biogenic sulfur from this biome is 2-3 x 10(exp 8) g/yr. This represents less than 0.001 percent of the estimated annual global flux (approximately 50 Tg) of biogenic sulfur and less than 0.01 percent of the estimated terrestrial flux. The low emissions are attributed to the low availability of sulfate, certain hydrological characteristics of tundra, and the tendency for tundra to accumulate organic matter.

  18. NATIONAL COASTAL CONDITION REPORT III

    EPA Science Inventory

    Coastal waers in the US include estuaries, coastal wetlands, coral reefs, ,mangrove and kelp forests, seagrass meadows, and upwelling areas. Critical coastal habitats provide spawning grounds, nurseries, shelter, and food for finfish, shellfish, birds, and other wildlife. The n...

  19. Estimation of coastal density gradients

    NASA Astrophysics Data System (ADS)

    Howarth, M. J.; Palmer, M. R.; Polton, J. A.; O'Neill, C. K.

    2012-04-01

    Density gradients in coastal regions with significant freshwater input are large and variable and are a major control of nearshore circulation. However their measurement is difficult, especially where the gradients are largest close to the coast, with significant uncertainties because of a variety of factors - spatial and time scales are small, tidal currents are strong and water depths shallow. Whilst temperature measurements are relatively straightforward, measurements of salinity (the dominant control of spatial variability) can be less reliable in turbid coastal waters. Liverpool Bay has strong tidal mixing and receives fresh water principally from the Dee, Mersey, Ribble and Conwy estuaries, each with different catchment influences. Horizontal and vertical density gradients are variable both in space and time. The water column stratifies intermittently. A Coastal Observatory has been operational since 2002 with regular (quasi monthly) CTD surveys on a 9 km grid, an situ station, an instrumented ferry travelling between Birkenhead and Dublin and a shore-based HF radar system measuring surface currents and waves. These measurements are complementary, each having different space-time characteristics. For coastal gradients the ferry is particularly useful since measurements are made right from the mouth of Mersey. From measurements at the in situ site alone density gradients can only be estimated from the tidal excursion. A suite of coupled physical, wave and ecological models are run in association with these measurements. The models, here on a 1.8 km grid, enable detailed estimation of nearshore density gradients, provided appropriate river run-off data are available. Examples are presented of the density gradients estimated from the different measurements and models, together with accuracies and uncertainties, showing that systematic time series measurements within a few kilometres of the coast are a high priority. (Here gliders are an exciting prospect for

  20. A Coastal Flood Decision Support Tool for Forecast Operations in Alaska

    NASA Astrophysics Data System (ADS)

    van Breukelen, C. M.; Moore, A.; Plumb, E. W.

    2015-12-01

    ABSTRACT Coastal flooding and erosion poses a serious threat to infrastructure, livelihood, and property for communities along Alaska's northern and western coastline. While the National Weather Service Alaska Region (NWS-AR) forecasts conditions favorable for coastal flooding, an improvement can be made in communicating event impacts between NWS-AR and local residents. Scientific jargon used by NWS-AR to indicate the severity of flooding potential is often misconstrued by residents. Additionally, the coastal flood forecasting process is cumbersome and time consuming due to scattered sources of flood guidance. To alleviate these problems, a single coastal flooding decision support tool was created for the Fairbanks Weather Forecast Office to help bridge the communication gap, streamline the forecast and warning process, and take into account both the meteorological and socioeconomic systems at work during a flood event. This tool builds on previous research and data collected by the Alaska Division of Geological and Geophysical Surveys (DGGS) and the NWS-AR, using high resolution elevation data to model the impacts of storm tide rise above the mean lower low water level on five of the most at-risk communities along the Alaskan coast. Important local buildings and infrastructure are highlighted, allowing forecasters to relate the severity of the storm tide in terms of local landmarks that are familiar to residents. In this way, this decision support tool allows for a conversion from model output storm tide levels into real world impacts that are easily understood by forecasters, emergency managers, and other stakeholders, helping to build a Weather-Ready Nation. An overview of the new coastal flood decision support tool in NWS-AR forecast operations will be discussed. KEYWORDS Forecasting; coastal flooding; coastal hazards; decision support

  1. The Apparent Periodicity of Felt Reports in the Alaskan Earthquake Record

    NASA Astrophysics Data System (ADS)

    Hafner, L. A.; McNutt, S. R.

    2004-12-01

    Felt reports for Alaskan earthquakes were found to be non-uniformly distributed throughout the year. With a predominantly tourist economy, the Alaskan population nearly triples in the summer months, possibly affecting the reporting of earthquakes in the historical record. Using published felt reports from the National Earthquake Information Center and the Alaska Earthquake Information Center, the percentage of events felt each month in central mainland Alaska were tabulated and compared between the summer and winter seasons. Earthquakes were selected from January 1, 1990 to October 31, 2002, from latitudes 58 to 70 degrees N and longitudes 140 to 160 degrees W, and depths 0 to 200 km. 408 events were felt out of a total of 695 that occurred. A number of parameters, including time of day, latitude, longitude, and magnitude, were additionally compared to specify possible limiting factors within each season. While a strong seasonal effect was not found in magnitude 4.0 ML events and greater, the months of May and June were consistently found to have the highest percentage of felt events with a steep drop occurring in the month of July. We ascribe this effect to the summer melting of the top layer of frozen ground to a depth of about 1.5 meters. Additionally, smaller events from magnitude 1.0 to 4.0 ML were also examined. 396 events were felt out of a total of 7,451 that occurred. We found that small earthquakes were felt, with a significant difference, more readily during summer months than in winter. This is likely an effect of the higher summer population of tourists and greater distribution of open businesses. Together these observations suggest that the historical Alaskan earthquake record is likely biased in favor of more frequent reporting of events occurring in summer months as opposed to winter.

  2. Implications of lifting the ban on the export of Alaskan crude oil: Price and trade impacts

    SciTech Connect

    Not Available

    1990-06-26

    This study addresses the issue of the ban on exports of Alaskan crude oil. At present almost all crude oil production from Alaska must be sold in the United States, i.e., it may not be exported. This study examines the impact, mainly on the West Coast, of eliminating this export restraint. The study concentrates on two time periods. These are 1988, the most recent year for which complete data are available, and 1995, a year in which Alaskan production is projected to be substantially less than at present. This is the Energy Information Administration's (EIA's) second report on this subject. The first was released earlier in 1990. They differ principally in the years for which results are presented and in the models used to generate quantitative results. The first report was limited to 1988. The quantitative results for that year were based on use of a single region model and therefore did not take into account petroleum interactions among all areas of the world. Because of this limitation, quantitative results were limited to Alaskan crude oil prices. All other price and trade flow results were qualitative. In contrast, the present report covers both 1988 and 1995. The quantitative results are generated with use of a more comprehensive model, one which does take into account petroleum interactions among all areas of the world. The model-generated results cover both crude and product prices as well as petroleum trade flows. The quantitative results in the present report therefore supersede those in the first, although both sets are generally consistent.

  3. Earthquake triggering at alaskan volcanoes following the 3 November 2002 denali fault earthquake

    USGS Publications Warehouse

    Moran, S.C.; Power, J.A.; Stihler, S.D.; Sanchez, J.J.; Caplan-Auerbach, J.

    2004-01-01

    The 3 November 2002 Mw 7.9 Denali fault earthquake provided an excellent opportunity to investigate triggered earthquakes at Alaskan volcanoes. The Alaska Volcano Observatory operates short-period seismic networks on 24 historically active volcanoes in Alaska, 247-2159 km distant from the mainshock epicenter. We searched for evidence of triggered seismicity by examining the unfiltered waveforms for all stations in each volcano network for ???1 hr after the Mw 7.9 arrival time at each network and for significant increases in located earthquakes in the hours after the mainshock. We found compelling evidence for triggering only at the Katmai volcanic cluster (KVC, 720-755 km southwest of the epicenter), where small earthquakes with distinct P and 5 arrivals appeared within the mainshock coda at one station and a small increase in located earthquakes occurred for several hours after the mainshock. Peak dynamic stresses of ???0.1 MPa at Augustine Volcano (560 km southwest of the epicenter) are significantly lower than those recorded in Yellowstone and Utah (>3000 km southeast of the epicenter), suggesting that strong directivity effects were at least partly responsible for the lack of triggering at Alaskan volcanoes. We describe other incidents of earthquake-induced triggering in the KVC, and outline a qualitative magnitude/distance-dependent triggering threshold. We argue that triggering results from the perturbation of magmatic-hydrothermal systems in the KVC and suggest that the comparative lack of triggering at other Alaskan volcanoes could be a result of differences in the nature of magmatic-hydrothermal systems.

  4. Resilience from coastal protection.

    PubMed

    Ewing, Lesley C

    2015-10-28

    Coastal areas are important residential, commercial and industrial areas; but coastal hazards can pose significant threats to these areas. Shoreline/coastal protection elements, both built structures such as breakwaters, seawalls and revetments, as well as natural features such as beaches, reefs and wetlands, are regular features of a coastal community and are important for community safety and development. These protection structures provide a range of resilience to coastal communities. During and after disasters, they help to minimize damages and support recovery; during non-disaster times, the values from shoreline elements shift from the narrow focus on protection. Most coastal communities have limited land and resources and few can dedicate scarce resources solely for protection. Values from shore protection can and should expand to include environmental, economic and social/cultural values. This paper discusses the key aspects of shoreline protection that influence effective community resilience and protection from disasters. This paper also presents ways that the economic, environmental and social/cultural values of shore protection can be evaluated and quantified. It presents the Coastal Community Hazard Protection Resilience (CCHPR) Index for evaluating the resilience capacity to coastal communities from various protection schemes and demonstrates the use of this Index for an urban beach in San Francisco, CA, USA. PMID:26392613

  5. NATIONAL COASTAL CONDITION REPORT

    EPA Science Inventory

    The National Coastal Condition report compiles several available data sets from different agencies and areas of the country and summarizes them to present a broad baseline picture of the condition of coastal waters. Although data sets presented in this report do not cover all coa...

  6. NATIONAL COASTAL ASSESSMENT

    EPA Science Inventory

    The purpose of the National Coastal Assessment (NCA) is to estimate the status and trends of the condition of the nation's coastal resources on a state, regional and national basis. Based on NCA monitoring from 1999-2001, 100% of the nation's estuarine waters (at over 2500 locati...

  7. Coastal zone management

    NASA Technical Reports Server (NTRS)

    Tilton, E. L., III

    1975-01-01

    A panel of federal and state representatives concerned with coastal zone affairs discussed their problems in this area. In addition, several demonstrations of the application of remote sensing technology to coastal zone management were described. These demonstrations were performed by several agencies in a variety of geographical areas.

  8. Three Years of CARVE-FTS Observations of CO2, CH4, and CO in the Alaskan Arctic: Status Quo and Comparison with Satellite Measurements

    NASA Astrophysics Data System (ADS)

    Kurosu, T. P.; Miller, C. E.; Dinardo, S. J.

    2014-12-01

    The Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) is an aircraft-based Earth Venture 1 mission to study the carbon balance of the Alaskan Arctic ecosystem, with a particular focus on carbon release from melting permafrost. Operating from its base in Fairbanks, AK, the CARVE aircraft covers a range of principle flight paths in the Alaskan interior, the Yukon River valley, and the northern Alaska coast around Barrow and Dead Horse. Flight paths are chosen to maximize ecosystem variability and cover burn-recovery/regrowth sequences. CARVE observations cover the Arctic Spring/Summer/Fall seasons, with multiple flights per season and principle flight path. Science operations started in 05/2012 and are currently envisaged to continue until 2015. The CARVE suite of instruments includes flask measurements, in situ gas analyzers for CO2, CH4 and CO observations, and a three-band polarizing Fourier Transform Spectrometer (FTS) for column measurements of CO2, CH4, CO, their interfering species (e.g., H2O), and O2. The FTS covers the spectral regions of 4,200-4,900 cm-1 (CH4, CO), 5,800-6,400 cm-1 (CO2), and 12,900-13,200 cm-1 (O2), with a spectral resolution of 0.2 cm-1. Aircraft-based FTS science observations in Alaska have been performed since 23-05-2012. First-version data products from all CARVE instruments derived from observations during the 2012 campaign were publicly released earlier in 2013. The FTS has performed well during flight conditions, particularly with respect to vibration damping. We present results from FTS column observations of CO2, CH4, and CO, observed during the 2012, 2013, and 2014 campaigns, including comparisons of CARVE FTS measurements with satellite observations of CO2 from TANSO/GOSAT retrieved by JPL/ACOS, and MOPITT CO.

  9. Enhanced removal of Exxon Valdez spilled oil from Alaskan gravel by a microbial surfactant.

    PubMed

    Harvey, S; Elashvili, I; Valdes, J J; Kamely, D; Chakrabarty, A M

    1990-03-01

    Remediation efforts for the oil spill from the Exxon Valdez tanker in Alaska have focused on the use of pressurized water at high temperature to remove oil from the beaches. We have tested a biological surfactant from Pseudomonas aeruginosa for its ability to remove oil from contaminated Alaskan gravel samples under various conditions, including concentration of the surfactant, time of contact, temperature of the wash, and presence or absence of xanthan gum. The results demonstrate the ability of the microbial surfactant to release oil to a significantly greater extent (2 to 3 times) than water alone, particularly at temperatures of 30 degrees C and above. PMID:1367420

  10. First Alaskan records and a significant northern range extension for two species of Diplura (Diplura, Campodeidae)

    PubMed Central

    Sikes, Derek S.; Allen, Robert T.

    2016-01-01

    Abstract Species in the class Diplura are recorded from Alaska for the first time. Two species, Tricampa rileyi Silvestri from Dall and Prince of Wales Islands in the Alexander Archipelago of Southeast Alaska and Metriocampa allocerca Conde & Geeraert from near Quartz Lake, southeast of Fairbanks, both in the family Campodeidae, are documented based on recently collected specimens deposited in the University of Alaska Museum Insect Collection. A brief review of the history of the documentation of the Alaskan soil microarthropod fauna is provided, as well as discussion of possible glacial refugia. PMID:27047242

  11. Alaskan marine mammal tissue archival project: a project description including collection protocols

    SciTech Connect

    Becker, P.R.; Wise, S.A.; Koster, B.J.; Zeisler, R.

    1988-03-01

    The Alaskan Marine Mammal Tissue Archival Project was initiated in 1987. Although the emphasis is on the collection of tissues for analysis of contaminants that may be associated with the petroleum industry, the development of an archive of marine mammal tissues collected and stored using carefully controlled procedures provides an important resource addressing questions concerning the transport of elements and compounds (contaminants and non-contaminants) throughout the polar ecosystem. The document provides the basic information on Project objectives and management, justification for the species, tissues, and contaminants of interest, and specific instructions for collecting, handling, and storing samples.

  12. Enhanced removal of Exxon Valdez spilled oil Alaskan gravel by a microbial surfactant

    SciTech Connect

    Harvey, S.; Elashvili, I.; Valdes, J.J.; Kamely, D.; Chakrabarty, A.M. )

    1990-03-01

    Remediation efforts for the oil spill from the Exxon Valdez tanker in Alaska have focused on the use of pressurized water at high temperature to remove oil from the beaches. We have tested a biological surfactant from Pseudomonas aeruginosa for its ability to remove oil from contaminated Alaskan gravel samples under various conditions, including concentration of the surfactant, time of contact, temperature of the wash, and presence or absence of xanthan gum. The results demonstrate the ability of the microbial surfactant to release oil to a significantly greater extent (2 to 3 times) than water alone, particularly at temperatures of 30{degree}C and above.

  13. The Changing Alaskan Experience—Health Care Services and Cultural Identity

    PubMed Central

    Dixon, Mim; Myers, Wayne W.; Book, Patricia A.; Nice, Philip O.

    1983-01-01

    Before Western contact, Alaskan Native populations were self-sufficient in their health practices. Slowly, the Native health care system was replaced by a Western one which was highly effective in treating infectious diseases. As infectious diseases were brought under control by the Indian Health Service, the emergent leading health problems were related to violence, attributed in part to cultural disintegration. New types of Native health providers and new Native-controlled institutions evolved to provide culturally appropriate health and mental health services and to promote a stronger cultural identity. PMID:6666110

  14. Paleoclimatic forcing of magnetic susceptibility variations in Alaskan loess during the late Quaternary

    SciTech Connect

    Beget, J.E.; Stone, D.B.; Hawkins, D.B. )

    1990-01-01

    Visual matches and statistical tests suggest correlations between marine isotope curves, retrodictive solar insolation at lat 65{degree}N, and magnetic susceptibility profiles through late Quaternary age Alaskan loess sections. The susceptibility changes largely appear to reflect variability in magnetite content due to climatically controlled changes in wind intensity and competence. Magnetic susceptibility profiles through massive loess can provide stratigraphic context for intercalated paleosols and tephras. A prominent paleosol correlated with marine isotope stage 5 occurs several metres above the Old Crow ash in loess sections, indicating that this important tephra is older than suggested by thermoluminescence dates, and may have been deposited ca. 215 {plus minus}25 ka.

  15. Atmospheric transport and diffusion mechanisms in coastal circulation systems

    SciTech Connect

    Kaleel, R.J.; Shearer, D.L.; MacRae, B.L.

    1983-06-01

    This study defines the cyclical aspects of coastal atmospheric behavior that are important to the transport and diffusion (dispersion) of radionuclides. The report is developed around discussions of the meteorological dynamics of the cyclical and (cellular) atmospheric coastal phenomena and the atmospheric transport/diffusion mechanisms along with an assessment of the measurements accompanying both. Further, the efforts directed to modeling both the atmospheric and transport/diffusion processes are summarized and evaluated. Lastly, the review is summarized through a set of conclusions about the current level of understanding of coastal atmospheric phenomena. Recommendations are offered which identify certain aspects of local scale cyclical coastal phenomena that are important to the NRC.

  16. Coastal Awareness: A Resource Guide for Teachers in Elementary Science.

    ERIC Educational Resources Information Center

    Rasmussen, Frederick A.

    Intended to encourage elementary teachers to explore coastal ecology with their students, this guide presents background material, activity suggestions, and recommended resource materials that could be used in designing a week-long unit on Coastal Awareness. Discussed is how various physical processes such as waves, tides, and currents affect…

  17. Estuaries and coastal waters need help

    SciTech Connect

    Levenson, H.

    1987-11-01

    For years, our marine environments-estuaries, coastal waters, and the open ocean-have been used extensively by coastal communities and industries for the disposal of various wastes. Historically, marine waste disposal has been relatively cheap and has solved some short-term waste-management problems; however, its consequences include a general trend toward environmental degradation, particularly in estuaries and coastal waters. Thus, without protective measures, the next few decades will witness degradation in many estuaries and some coastal waters around the country. The extent of current degradation varies greatly around the country. Although it is difficult to ascertain cause and effect relationships, enough evidence exists to conclude that the pollutants in question include disease-causing microorganisms, oxygen-demanding substances, particulate material, metals, and organic chemicals. Two statutes form the basis of most federal regulatory efforts to combat marine pollution: the Marine Protection, Research, and Sanctuaries Act (MPRSA) and the Clean Water Act (CWA). The MPRSA regulates the dumping of wastes in coastal and open-ocean waters, whereas the CWA has jurisdiction over pipeline discharges in all marine waters, wastes dumped in estuaries, and runoff. Many people consider that the passage and implementation of these two acts and their ensuing amendments established a statutory structure sufficient to protect the nation's waters from pollution. However, these provisions have not protected some estuaries and coastal waters from degradation.

  18. Coastal Hazards: Hurricanes, Tsunamis, Coastal Erosion.

    ERIC Educational Resources Information Center

    Vandas, Steve

    1998-01-01

    Details an ocean-based lesson and provides background information on the designation of 1998 as the "Year of the Ocean" by the United Nations. Contains activities on the poster insert that can help raise student awareness of coastal-zone hazards. (DDR)

  19. Sea-ice and surface water circulation, Alaskan continental shelf

    NASA Technical Reports Server (NTRS)

    Wright, F. F.; Sharma, G. D.; Burns, J. J. (Principal Investigator)

    1973-01-01

    The author has identified the following significant results. Over 1500 water samples from surface and from standard hydrographic depths were collected during June and July 1973 from Bering Sea and Gulf of Alaska. The measurement of temperature, salinity, and productivity indicated that various distinct water masses cover the Bering Sea Shelf. The suspended load in surface waters will be correlated with the ERTS-1 imagery as it becomes available to delineate the surface water circulation. The movement of ice floes in the Bering Strait and Bering Sea indicated that movement of ice varies considerably and may depend on wind stress as well as ocean currents.

  20. Coastal erosion and accretion rates in Greece

    NASA Astrophysics Data System (ADS)

    Foteinis, Spyros; Papadopoulos, Costas; Koutsogiannaki, Irini; Synolakis, Costas

    2010-05-01

    Erosion threatens many coastal regions of Greece. Anthropogenic changes of landforms such as coastal roads built on even narrow beaches, sand mining for construction, poor design of coastal structures that interfere with sediment, and dams without sediment bypasses have significantly reduced beach widths. We present erosion rates for different beaches, some of which are in sensitive ecosystems, otherwise "protected" by local and EU ordinances. By comparing inferences of beach widths in varying intervals from 1933 to 2006, we infer that the construction of dams in Acheloos river in western Greece, built in a faraonic attempt to partially divert its flows to eastern Greece, this is responsible for up to 20m/year erosion rates observed in certain locales in the Acheloos delta. More characteristic erosion rates in the region are ~ 2m/year. By contrast, there appears rapid accretion of up to 4m/year in the beaches around the Nestos delta in northern Greece (Papadopoulos, 2009). In beaches that are not near large river deltas, erosion rates range from 0.5m/year to 1m/year. While we have not done comprehensive comparisons among coastlines with different levels of coastal development, it does appear that rapid coastal development correlates well with erosion rates. The underlying problem is the complete lack of any semblance of coastal zone management in Greece and substandard design of coastal structures, which are often sited without any measurements of waves and currents offshore (Synolakis et al, 2008). Beach maintenance remains an exotic concept for most local authorities, who invariably prefer to build hard coastal structures to "protect" versus nourish, siting lack of experience with nourishment and "environmental" concerns. In certain cases, choices are dictated by costs, the larger the cost the easier the project gets approved by regulatory authorities, hence the preference for concrete or rubble structures. We conclude that, unless urgent salvage measures are

  1. Coastal mapping handbook

    USGS Publications Warehouse

    U.S. Geological Survey; National Oceanic and Atmospheric Administration; Ellis, Melvin Y., (Edited By)

    1978-01-01

    Passage of the Coastal Zone Management Act of 1972 focused attention on the Nation's coastal land and water areas. As plans for more effective management of the coastal zone evolved, it soon became apparent that improved maps and charts of these areas were needed. This handbook was prepared with the requirements of the entire coastal community in mind, giving greatest attention to the needs of coastal zone managers and planners at the State and local levels. Its principal objective is to provide general information and guidance; it is neither a textbook nor a technical manual, but rather a primer on coastal mapping. This handbook should help planners and managers of coastal programs to determine their mapping requirements, select the best maps and charts for their particular needs, and to deal effectively with personnel who gather data and prepare maps. The sections on "Sources of Assistance and Advice" and "Product and Data Sources" should be especially useful to all involved in mapping the coastal zone. Brief summaries of the mapping efforts of several State coastal zone management programs are included. "Future outlook" discusses anticipated progress and changes in mapping procedures and techniques. Illustrations are inserted, where appropriate, to illustrate the products and equipment discussed. Because of printing restrictions, the colors in map illustrations may vary from those in the original publication. The appendixes include substantial material which also should be of interest. In addition a glossary and an index are included to provide easy and quick access to the terms and concepts used in the text. For those interested in more technical detail than is provided in this handbook, the "Selected references" will be useful. Also, the publications of the professional societies listed in appendix 4 will provide technical information in detail.

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

    USGS Publications Warehouse

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

    2014-01-01

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

  3. Preliminary study on total mercury in the common prepared subsistence foods of a rural Alaskan village.

    PubMed

    Rothschild, Roger F N; Duffy, Lawrence K

    2002-01-01

    Total mercury (THg), which includes neurotoxic methylmercury (MeHg), poses a health risk to subsistence food users in the circumpolar north. Low levels of THg, usually below 200 ng/g, have been reported in fish muscle from both returning salmon and freshwater species samples on the Kuskokwim River in southwest Alaska. Alaska subsistence users use fish all year long, with both salmon and freshwater species stored for winter usage. A recent study showed low mercury levels in the hair of villagers and suggested that in the last 25 years, MeHg exposure has remained the same or slightly decreased in the Bethel region of Alaska. Although several previous studies have measured THg in hair of Alaskan subsistence food users, few studies have looked at the THg levels in the prepared foods of rural Alaskans. Several types of subsistence foods from Napakiak, a small Yup'ik Eskimo village on the Kuskokwim River, were assessed for total mercury content. The THg levels were low, ranging from 1 ng/g to 443.8 ng/g. A trend for the dried fish to have higher concentrations than the unprocessed fish was observed. Plants, as well as raindeer and moose meats, are low in THg and not associated with dietary exposure. Our data for Napakiak show that THg levels are low enough that mercury does not pose a significant health risk; however, more detailed consumption data in western Alaska is needed. PMID:12650086

  4. Atmospheric methane sources - Alaskan tundra bogs, an alpine fen, and a subarctic boreal marsh

    NASA Technical Reports Server (NTRS)

    Sebacher, D. I.; Harriss, R. C.; Grice, S. S.; Bartlett, K. B.; Sebacher, S. M.

    1986-01-01

    Methane (CH4) flux measurements from Alaska tundra bogs, an alpine fen, and a subarctic boreal marsh were obtained at field sites ranging from Prudhoe Bay on the coast of the Arctic Ocean to the Alaskan Range south of Fairbanks during August 1984. In the tundra, average CH4 emission rates varied from 4.9 mg CH4 per sq m per day (moist tundra) to 119 mg CH4 per sq m per day (waterlogged tundra). Fluxes averaged 40 mg CH4 per sq m per day from wet tussock meadows in the Brooks Range and 289 mg Ch4 per sq m per day from an alpine fen in the Alaskan Range. The boreal marsh had an average CH4 emission rate of 106 mg CH4 per sq m per day. Significant emissions were detected in tundra areas where peat temperatures were as low as 4 C, and permafrost was only 25 cm below the ground surface. Emission rates from the 17 sites sampled were found to be logarithmically related to water levels at the sites. Extrapolation of the data to an estimate of the total annual CH4 emission from all arctic and boreal wetlands suggests that these ecosystems are a major source of atmospheric CH4 and could account for up to 23 percent of global CH4 emissions from wetlands.

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

    USGS Publications Warehouse

    2010-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

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

  7. Hurricane Ike: Observations and Analysis of Coastal Change

    USGS Publications Warehouse

    Doran, Kara S.; Plant, Nathaniel G.; Stockdon, Hilary F.; Sallenger, Asbury H.; Serafin, Katherine A.

    2009-01-01

    Understanding storm-induced coastal change and forecasting these changes require knowledge of the physical processes associated with the storm and the geomorphology of the impacted coastline. The primary physical processes of interest are the wind field, storm surge, and wave climate. Not only does wind cause direct damage to structures along the coast, but it is ultimately responsible for much of the energy that is transferred to the ocean and expressed as storm surge, mean currents, and large waves. Waves and currents are the processes most responsible for moving sediments in the coastal zone during extreme storm events. Storm surge, the rise in water level due to the wind, barometric pressure, and other factors, allows both waves and currents to attack parts of the coast not normally exposed to those processes. Coastal geomorphology, including shapes of the shoreline, beaches, and dunes, is equally important to the coastal change observed during extreme storm events. Relevant geomorphic variables include sand dune elevation, beach width, shoreline position, sediment grain size, and foreshore beach slope. These variables, in addition to hydrodynamic processes, can be used to predict coastal vulnerability to storms The U.S. Geological Survey's (USGS) National Assessment of Coastal Change Hazards Project (http://coastal.er.usgs.gov/hurricanes), strives to provide hazard information to those interested in the Nation's coastlines, including residents of coastal areas, government agencies responsible for coastal management, and coastal researchers. As part of the National Assessment, observations were collected to measure coastal changes associated with Hurricane Ike, which made landfall near Galveston, Texas, on September 13, 2008. Methods of observation included aerial photography and airborne topographic surveys. This report documents these data-collection efforts and presents qualitative and quantitative descriptions of hurricane-induced changes to the shoreline

  8. Framework for Vulnerability Assessment of Coastal Infrastructure

    NASA Astrophysics Data System (ADS)

    Obrien, P. S.; Moritz, H. R.; White, K. D.

    2015-12-01

    Coastal infrastructure can be highly vulnerable to changing climate, including increasing sea levels and altered frequency and intensity of coastal storms. Existing coastal infrastructure may be of a sufficient age that it is already experiencing noticeable impacts from global sea level rise, and require a variety of potential preparedness and resilience measures to adapt to changing climate. Methods to determine vulnerability to changing sea level and support planning of potential future adaptation measures are needed for application to projects having multiple purposes (e.g., navigation, coastal risk reduction). Here we describe a potential framework for assessing projects with several components typical of existing coastal infrastructure spanning a range of engineering disciplines (e.g., hydrology, geotechnical, structural, electrical, and mechanical). The US Army Corps of Engineers (USACE) Climate Preparedness and Resilience Register (CPRR) framework is currently under development. It takes a tiered approach as described in earlier USACE guidance (Engineer Technical Letter 1100-2-1) using the three scenarios prescribed by Engineer Regulation ER 1100-2-8162. Level 1 is a qualitative assessment defining the major sea level change-related impacts and ranks them in order of soonest occurrence. Level 2 is a quantitative evaluation that analyzes current and future performance of individual project components, including electrical, mechanical and structural components and functions using the sea level change scenarios prescribed by ER 1100-2-8162. Level 3 proposes adaptation measures per ETL 1100-2-1 and evaluates changes in sea level change-related impacts.

  9. University of Alaska Coastal Marine Institute annual report number 5, fiscal year 1998

    SciTech Connect

    Alexander, V.

    1998-12-18

    The University of Alaska Coastal Marine Institute (CMI) was created by a cooperative agreement between the University of Alaska and the Minerals Management Service (MMS) in June 1993 and the first full funding cycle began late in (federal) fiscal year 1994. CMI is pleased to present this 1998 Annual Report for studies ongoing in Oct 1997--Sep 1998. Only abstracts and study products for ongoing projects are included here. They include: An Economic Assessment of the Marine Biotechnology; Kachemak Bay Experimental and Monitoring Studies; Historical Changes in Trace Metals and Hydrocarbons in the Inner Shelf Sediments; Beaufort Sea: Prior and Subsequent to Petroleum-Related Industrial Developments; Physical-Biological Numerical Modeling on Alaskan Arctic Shelves; Defining Habitats for Juvenile Flatfishes in Southcentral Alaska; Relationship of Diet to Habitat Preferences of Juvenile Flatfishes, Phase 1; Subsistence Economies and North Slope Oil Development; Wind Field Representations and Their Effect on Shelf Circulation Models: A Case Study in the Chukchi Sea; Interaction between Marine Humic Matter and Polycyclic Aromatic Hydrocarbons in Lower Cook Inlet and Port Valdez, Alaska; Correction Factor for Ringed Seal Surveys in Northern Alaska; Feeding Ecology of Maturing Sockeye Salmon (Oncorhynchus nerka) in Nearshore Waters of the Kodiak Archipelago; and Circulation, Thermohaline Structure, and Cross-Shelf Transport in the Alaskan Beaufort Sea.

  10. American Indian/Alaskan Native Undergraduate Retention at Predominantly White Institutions: An Elaboration of Tinto's Theory of College Student Departure

    ERIC Educational Resources Information Center

    Lee, Junghee; Donlan, William; Brown, Eddie F.

    2011-01-01

    This article reports findings from a major public university sponsored study undertaken with the intention of (a) improving university understanding of factors affecting American Indian/Alaskan Native (AI/AN) undergraduates' persistence at this institution, and (b) identifying in what areas, and in what manner, this institution could improve…

  11. ENHANCEMENT OF BIODEGRADATION OF ALASKAN WEATHERED CRUDE OIL COMPONENTS BY INDIGENOUS MICROBIOTA WITH THE USE OF FERTILIZERS AND NUTRIENTS

    EPA Science Inventory

    Bench-scale biodegradability studies of the Alaskan weathered crude oil were undertaken as part of the bioremediation project for the shorelines of Prince William Sound, Alaska, contaminated by the Exxon oil spill. he purpose of the studies was to evaluate the capability of the i...

  12. TISSUE DISTRIBUTION OF PCBS AND ORGANOCHLORINE PESTICIDES IN ALASKAN NORTHERN FUR SEALS: COMPARISON OF VARIOUS CONGENER CLASSIFICATION SCHEMES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) are believed to adversely affect reproduction and cause health problems in Pinnipeds 1-4. In this study, 145 PCB congeners and OCPs were analyzed in 10 juvenile male northern fur seals, Callorhinus ursinus, collected from Alaskan...

  13. Enhancing highly unsaturated omega-3 fatty acids in phase-fed rainbow trout (Oncorhynchus mykiss) using Alaskan fish oils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this research was to investigate differences in the kinetics of fatty acids (FA) deposition in fillets of market-sized (approximately 450g) rainbow trout (Oncorhynchus mykiss) fed diets containing commercial Alaskan fish oils versus menhaden oil. Comparisons were made with FA leve...

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

    ERIC Educational Resources Information Center

    Picou, J. Steven; And Others

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

  15. Population structure over a broad spatial scale driven by nonanthropogenic factors in a wide-ranging migratory mammal, Alaskan caribou.

    PubMed

    Mager, Karen H; Colson, Kevin E; Groves, Pam; Hundertmark, Kris J

    2014-12-01

    Wide-ranging mammals face significant conservation threats, and knowledge of the spatial scale of population structure and its drivers is needed to understand processes that maintain diversity in these species. We analysed DNA from 655 Alaskan caribou (Rangifer tarandus granti) from 20 herds that vary in population size, used 19 microsatellite loci to document genetic diversity and differentiation in Alaskan caribou, and examined the extent to which genetic differentiation was associated with hypothesized drivers of population subdivision including landscape features, population size and ecotype. We found that Alaskan caribou are subdivided into two hierarchically structured clusters: one group on the Alaska Peninsula containing discrete herds and one large group on the Mainland lacking differentiation between many herds. Population size, geographic distance, migratory ecotype and the Kvichak River at the nexus of the Alaska Peninsula were associated with genetic differentiation. Contrary to previous hypotheses, small Mainland herds were often differentiated genetically from large interconnected herds nearby, and genetic drift coupled with reduced gene flow may explain this pattern. Our results raise the possibility that behaviour helps to maintain genetic differentiation between some herds of different ecotypes. Alaskan caribou show remarkably high diversity and low differentiation over a broad geographic scale. These results increase information for the conservation of caribou and other migratory mammals threatened by population reductions and landscape barriers and may be broadly applicable to understanding the spatial scale and ecological drivers of population structure in widespread species. PMID:25403098

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

    ERIC Educational Resources Information Center

    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.…

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Baked starch/pulp foams were prepared from formulations containing 0-25% (wt%) 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 wi...

  18. One-to-One in Alaska: In the Remote Alaskan Interior, Students are Reaping the Benefits of Laptop Computing

    ERIC Educational Resources Information Center

    McHale, Tom

    2007-01-01

    Each school, district, or state has a unique set of circumstances and obstacles to deal with in implementing a one-to-one laptop program. That is especially true of Denali Borough School District in Alaska. Located in the Alaskan interior, it encompasses Denali National Park (with North America's tallest mountain), covers more than 12,000 square…

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

    ERIC Educational Resources Information Center

    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…

  20. Arctic Coastal Dynamics (ACD)

    NASA Astrophysics Data System (ADS)

    Rachold, V.; Boike, J.

    2003-04-01

    Coastal dynamics directly reflecting the complicated land-ocean interactions play an important role in the balance of sediments, organic carbon and nutrients in the Arctic basin. Recent studies indicate that sediment input to the Arctic shelves resulting from erosion of ice-rich, permafrost-dominated coasts may be equal to or greater than input from river discharge. Thus, the understanding and quantification of coastal processes is critical for interpreting the geological history of the Arctic shelves. The predictions of future behavior of these coasts in response to climatic and sea level changes is an important issue because most of the human activity that occurs at high latitudes concentrates on the Arctic coastlines. As an initiative of the International Permafrost Association (IPA) the multi-disciplinary, multi-national forum Arctic Coastal Dynamics (ACD), which was recently accepted as a project of the International Arctic Sciences Committee (IASC), had been developed. The overall objective of ACD is to improve our understanding of circum-Arctic coastal dynamics as a function of environmental forcing, coastal geology and cryology and morphodynamic behavior. In particular, the project aims to: - establish the rates and magnitudes of erosion and accumulation of Arctic coasts; - develop a network of long-term monitoring sites including local community-based observational sites; - identify and undertake focused research on critical processes; - estimate the amount of sediments and organic carbon derived from coastal erosion; - refine and apply an Arctic coastal classification (includes ground-ice, permafrost, geology etc.) in digital form (GIS format); - extract and utilize existing information on relevant environmental forcing parameters (e.g. wind speed, sea level, fetch, sea ice etc.); - produce a series of thematic and derived maps (e.g. coastal classification, ground-ice, sensitivity etc.); - develop empirical models to assess the sensitivity of Arctic

  1. Stable Isotope Mapping of Alaskan Grasses and Marijuana

    NASA Astrophysics Data System (ADS)

    Booth, A. L.; Wooller, M. J.

    2008-12-01

    The spatial variation of isotope signatures in organic material is a useful forensic tool, particularly when applied to the task of tracking the production and distribution of plant-derived illicit drugs. In order to identify the likely grow-locations of drugs such as marijuana from unknown locations (i.e., confiscated during trafficking), base isotope maps are needed that include measurements of plants from known grow-locations. This task is logistically challenging in remote, large regions such as Alaska. We are therefore investigating the potential of supplementing our base (marijuana) isotope maps with data derived from other plants from known locations and with greater spatial coverage in Alaska. These currently include >150 samples of modern C3 grasses (Poaceae) as well as marijuana samples (n = 18) from known grow-locations across the state. We conducted oxygen, carbon and nitrogen stable isotope analyses of marijuana and grasses (Poaceae). Poaceae samples were obtained from the University of Alaska Fairbanks (UAF) Museum of the North herbarium collection, originally collected by field botanists from around Alaska. Results indicate that the oxygen isotopic composition of these grasses range from 10‰ to 30‰, and broadly mirror the spatial pattern of water isotopes in Alaska. Our marijuana samples were confiscated around the state of Alaska and supplied to us by the UAF Police Department. δ13C, δ15N and δ18O values exhibit geographic patterns similar to the modern grasses, but carbon and nitrogen isotopes of some marijuana plants appear to be influenced by additional factors related to indoor growing conditions (supplementary CO2 sources and the application of organic fertilizer). As well as providing a potential forensic resource, our Poaceae isotope maps could serve additional value by providing resources for studying ecosystem nutrient cycling, for tracing natural ecological processes (i.e., animal migration and food web dynamics) and providing

  2. Australian and Chinese Scientists Discuss Coastal Zone Management

    NASA Astrophysics Data System (ADS)

    Wang, Xiao Hua; Xu, Xiangmin

    2010-03-01

    Integrated Coastal Zone Management Workshop; Canberra, Australian Capital Territory, Australia, 11-14 November 2009; A 3-day workshop was held in Australia to discuss problems and issues facing coastal zones, including degradation of coastal ecosystems and the impacts of climate change such as sea level rise and changed weather patterns, and to formulate a collaborative research strategy to improve the coastal zone management (CZM) system to tackle these problems. The workshop, which brought together experts from University of New South Wales (UNSW) and Ocean University of China (OUC), highlighted the similarities in topics important to Australia and China. This workshop focused on science, policy, and the legal framework required to manage sustainable development of these coastal zones. Many parallels exist between the difficult issues facing CZM in both countries. Significant research into changes in coastal areas and their causes has been undertaken, but this research effort has not been fully reflected in coastal zone planning and management activities. Workshop participants reviewed current progress in understanding scientific, engineering, and socioeconomic processes in the coastal zones, brainstormed challenges in developing a multidisciplinary research framework capable of integrating science into coastal zone management, and identified a cross-institutional approach to addressing these issues.

  3. AN INTEGRATED COASTAL-WATERSHED MONITORING FRAMEWORK FOR ASSESSMENT

    EPA Science Inventory

    An approach for watershed classification in support of assessments, disgnosis of biological impairment, and prioritization of watershed restorations has been tested in coastal watersheds surrounding the western arm of Lake Superior and is currently being assessed for a series of ...

  4. California coastal processes study, LANDSAT 2

    NASA Technical Reports Server (NTRS)

    Pirie, D. M.; Steller, D. D. (Principal Investigator)

    1977-01-01

    The authors have identified the following significant results. By using suspended sediments as tracers, objectives were met by qualitative definition of the nearshore circulation along the entire coast of California with special study sites at Humboldt Bay, the mouth of the Russian River, San Francisco Bay, Monterey Bay, and the Santa Barbara Channel. Although LANDSAT primarily imaged fines and silts in the surface waters, the distribution of sediments allowed an examination of upwelling, convergences and coastal erosion and deposition. In Monterey Bay and Humboldt Bay, these coastal phenomena were used to trace seasonal trends in surface currents.

  5. Coastal geomorphology of arctic Alaska

    USGS Publications Warehouse

    Barnes, Peter W.; Rawlinson, Stuart E.; Reimnitz, Erk

    1988-01-01

    The treeless, tundra-plain of northern Alaska merges with the Arctic Ocean along a coastal area characterized by low tundra bluffs, and sparse coastal and delta dunes. Coastal engineering projects that aggrade or degrade permafrost will alter the geomorphology and rates of coastal processes by changing coastal stability. Similarly, projects that modify the ice environment (artificial islands) or the coastal configuration (causeways) will cause nature to readjust to the new process regime, resulting in modification of the coast. In this paper the authors describe the coastal geomorphology from Barrow to the Canadian border. In addition, they provide a general outline and extensive references of the major coastal processes operating in this environment that will be useful on coastal environments elsewhere in the Arctic.

  6. Atmospheric Forcing, Sea-Ice Interannual Variability, and Ocean Current Impacts on the Availability of Bowhead Whale Prey Near Barrow, AK

    NASA Astrophysics Data System (ADS)

    Berline, L.; Spitz, Y. H.; Maslowski, W.; Campbell, R. G.; Ashjian, C.

    2006-12-01

    The linkages between bowhead whale distributions, whale prey availability, ocean and ice processes, and atmospheric forcing and interannual environmental variability in the Northern Alaskan Coastal system near Barrow, AK are being explored through biological-physical modeling, field sampling, and retrospective analysis. Complimentary modeling approaches, based on the outputs of a pan-arctic ice-ocean model of 1/12° resolution and forced by realistic air-sea fluxes and wind stress, were employed to analyze the system response to several forcing scenarios typical of the last decade. The influence of extrinsic (Pacific) input of whale prey (euphausiids) to the region was explored. Euphausiids, an important prey of bowhead whales in the fall at Barrow, AK, must have been transported there from the Bering Sea since at present it is believed that they are not endemic. Transport experiments identified potential trajectories and transit times of euphausiids (whale prey) from Bering Strait to Barrow. For euphausiids seeded at the surface, the probability of reaching Barrow was only 1% in 1997 but 10% in 2002. Subsurface seeded euphausiids also traveled faster with the majority reaching Barrow one month earlier in 2002 than in 1997. These differences were due to stronger northward currents in 2002 than in 1997. Dye-tracer experiments identified the pathways and quantity of Pacific Water entering the Chukchi and Beaufort Seas as a proxy for biomass and nutrients. Results are discussed in the context of field observations. Future work will explore intrinsic mechanisms influencing whale prey abundance.

  7. Exposing the U.S. coastal zone

    NASA Astrophysics Data System (ADS)

    Pratson, Lincoln; Divins, David; Butler, Tanja; Metzger, Dan; Sharman, George; Steele, Mark; Berggren, Todd; Holcombe, Troy; Ramos, Ricardo

    Overdevelopment of shores and wetlands, dwindling sites on land for the disposal of human-generated waste, contamination of estuaries and nearshore sediments, the disruption of coastal-water ecosystems by dredging, and the specter of rising sea level due to anthropogenically induced global warming are but a few of the pressures humans are exerting on coastal environments around the world. In the United States, a lot is riding on the response of its coastal environments to these pressures. The majority of the U.S. population resides in the coastal states, where the country's largest cities and most popular recreation areas are located.If the United States is to sustain the health and beauty of its coastal environments, then they must be managed, not only on the federal scale, but also on the state and local scales. One of the most fundamental types of data required to conduct this management will be detailed elevation data. On land, topography dictates the flow of water and the maximum extent of flooding. Offshore, bathymetry is a major control on shallow-water ocean currents and the dissemination of sediments eroded from the continent.

  8. Coastal Rainfall Estimation using AMSR-E

    NASA Astrophysics Data System (ADS)

    McCollum, J.; Ferraro, R.

    2003-12-01

    The vast majority of microwave rainfall estimation research has been for either ocean-filled or land-filled fields of view, as the physics for both surface types are quite different. However, neither ocean-based nor land-based methods may be used for coastal pixels that contain a mixture of water and land. Current algorithms for coastal regions perform relatively poorly. We have built upon previous coastal rainfall algorithms developed for the Special Sensor Microwave/Imager (SSM/I) and TRMM Microwave Imager (TMI). Using principal component analysis, we found multi-frequency brightness temperature responses to rainfall over coastal regions, enabling us to do a more accurate rain/no-rain classification. The TMI has similar frequencies and resolutions as AMSR-E, so we could use the co-located TMI and Precipitation Radar (PR) data to determine the principal components related to rainfall. These principal components are effective in distinguishing rain from no-rain AMSR-E pixels, as we show with AMSR-E data. We include global results as well as those from the Eureka, CA, coastal radar AMSR-E validation site.

  9. Global climate change impacts on coastal ecosystems in the Gulf of Mexico: considerations for integrated coastal management

    USGS Publications Warehouse

    Day, John W.; Yáñez-Arancibia, Alejandro; Cowan, James H.; Day, Richard H.; Twilley, Robert R.; Rybczyk, John R.

    2013-01-01

    Global climate change is important in considerations of integrated coastal management in the Gulf of Mexico. This is true for a number of reasons. Climate in the Gulf spans the range from tropical to the lower part of the temperate zone. Thus, as climate warms, the tropical temperate interface, which is currently mostly offshore in the Gulf of Mexico, will increasingly move over the coastal zone of the northern and eastern parts of the Gulf. Currently, this interface is located in South Florida and around the US-Mexico border in the Texas-Tamaulipas region. Maintaining healthy coastal ecosystems is important because they will be more resistant to climate change.

  10. Wind influence on a coastal buoyant outflow

    NASA Astrophysics Data System (ADS)

    Whitney, Michael M.; Garvine, Richard W.

    2005-03-01

    This paper investigates the interplay between river discharge and winds in forcing coastal buoyant outflows. During light winds a plume influenced by the Earth's rotation will flow down shelf (in the direction of Kelvin wave propagation) as a slender buoyancy-driven coastal current. Downwelling favorable winds augment this down-shelf flow, narrow the plume, and mix the water column. Upwelling favorable winds drive currents that counter the buoyancy-driven flow, spread plume waters offshore, and rapidly mix buoyant waters. Two criteria are developed to assess the wind influence on a buoyant outflow. The wind strength index (Ws) determines whether a plume's along-shelf flow is in a wind-driven or buoyancy-driven state. Ws is the ratio of the wind-driven and buoyancy-driven along-shelf velocities. Wind influence on across-shelf plume structure is rated with a timescale (ttilt) for the isopycnal tilting caused by wind-driven Ekman circulation. These criteria are used to characterize wind influence on the Delaware Coastal Current and can be applied to other coastal buoyant outflows. The Delaware buoyant outflow is simulated for springtime high-river discharge conditions. Simulation results and Ws values reveal that the coastal current is buoyancy-driven most of the time (∣Ws∣ < 1 on average). Wind events, however, overwhelm the buoyancy-driven flow (∣Ws∣ > 1) several times during the high-discharge period. Strong upwelling events reverse the buoyant outflow; they constitute an important mechanism for transporting fresh water up shelf. Across-shelf plume structure is more sensitive to wind influence than the along-shelf flow. Values of ttilt indicate that moderate or strong winds persisting throughout a day can modify plume width significantly. Plume widening during upwelling events is accompanied by mixing that can erase the buoyant outflow.

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

    NASA Astrophysics Data System (ADS)

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

    2008-12-01

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

  12. Frequency of genes in aromatic and aliphatic hydrocarbon biodegradation pathways within bacterial populations from Alaskan sediments.

    PubMed

    Sotsky, J B; Greer, C W; Atlas, R M

    1994-11-01

    A significant proportion of the naturally occurring hydrocarbon-degrading populations within Alaskan sediments affected by the Exxon Valdez oil spill had both the xylE and alkB genes and could convert hexadecane and naphthalene to carbon dioxide; a greater proportion of the population had xylE than had alkB, reflecting the composition of the residual oil at the time of sampling; nearly equal populations with xylE alone, alkB alone, and xylE + alkB genes together were found after exposure to fresh crude oil; populations with xylE lacking alkB increased after enrichment on naphthalene. Thus, the genotypes of hydrocarbon-degrading populations reflected the composition of the hydrocarbons to which they were exposed. PMID:7804909

  13. Bowhead whale behavior in relation to seismic exploration, Alaskan Beaufort Sea, Autumn 1981. Study report (Final)

    SciTech Connect

    Fraker, M.A.; Ljungblad, D.K.; Richardson, W.J.; Van Schoik, D.R.

    1985-10-01

    Behavior of bowhead whales (Balsena mysticetus) in the eastern part of the Alaskan Beaufort Sea or near the Alaska/Yukon border was observed from a circling turbine-powered Goose aircraft on 10 dates from 12 September to 5 October 1981. On three of these dates, the whales were exposed t, noise impulses from seismic vessels 13 km or more away. Some behavioral data were acquired. In both the presence and the absence of seismic impulses, most bowheads appeared to be feeding in the water column, although slow travel and active socializing were sometimes detected. Sonobuoys detected bowhead calls both in the presence and the absence of seismic impulses. There was no clear evidence of unusual behavior in the presence of seismic impulses.

  14. Evaluation of three gears for sampling spawning populations of rainbow trout in a large Alaskan river

    USGS Publications Warehouse

    Schwanke, C.J.; Hubert, W.A.

    2004-01-01

    Alternatives to electrofishing are needed for sampling sexually mature rainbow trout Oncorhynchus mykiss during the spawning season in large Alaskan rivers. We compared hook and line, beach seining, and actively fished gill nets as sampling tools. Beach seining and active gill netting yielded similar catch rates, length frequencies, and sex ratios of sexually mature fish. Hook-and-line sampling was less effective, with a lower catch rate and selectivity for immature fish and sexually mature females. We conclude that both beach seining and active gill netting can serve as alternatives to electrofishing for sampling sexually mature rainbow trout stocks during the spawning season in large rivers with stable spring flows and spawning areas with few snags.

  15. Potential effects of oil spills and other chemical pollutants on marine mammals occurring in Alaskan waters

    SciTech Connect

    Hansen, D.J.

    1985-01-01

    The outer continental shelf report describes and assesses the potential effects of oil spills and other contaminants on marine mammals that occur in Alaskan waters, assuming that a spill or contamination occurs. The report focuses primarily on the potential direct and indirect effects of oil spills on marine mammals and addresses both short-term effects that may occur at the time of contact with oil, and long-term effects that may occur long after contact with oil. The report also briefly reviews the literature on the potential effects of other contaminants such as heavy metals and organochlorines (DDT and PCB's) on marine mammals. The assessment concludes that sea otters, polar bears, fur seals, and very young seal pups could suffer serious or lethal effects if contact with oil occurred.

  16. New evidence for the age of the Gubik Formation Alaskan North Slope

    USGS Publications Warehouse

    Repenning, C.A.

    1983-01-01

    At several Alaskan North Slope localities south of the shore of the Arctic Ocean the Gubik Formation, herein regarded as latest Pliocene and Pleistocene in age, contains a marine unit at its base. Near Ocean Point and near Teshekpuk Lake this basal unit, or the lowest exposed marine unit, of the Gubik contains unusual, relatively warm-water marine mammals. Although these mammals have poorly known fossil histories, consideration of what is known suggests that the basal marine unit near Ocean Point is of latest Pliocene age, between 2.2 and 1.7 my old, and that the marine unit near Teshekpuk Lake is probably late Pleistocene, most likely correlating with the Sangamon Interglaciation and about 120,000 yr old. ?? 1983.

  17. Alaskan oceanography

    NASA Astrophysics Data System (ADS)

    Physical oceanographers, chemists, and biologists will soon begin studying the seas around northern Alaska as part of an international effort to learn how increased fishing, oil and gas drilling, and land-based farming will affect marine life. The $2.5 million National Science Foundation (NSF)- funded study, called ISHTAR (Inner Shelf Transfer and Recycling in the Bering and Chukchi Seas), will involve scientists from the United States, Belgium, and Denmark.According to NSF, previous studies suggest that, despite a short growing season, the seas around the Bering Strait produce more plant life than most marine areas of the world. However, the source of mineral nutrients for this plant life and its destination in the food web or organic sediment is not well understood. The researchers will trace nutrients from the Yukon River and the deeper waters of the Bering Sea to the continental shelves of the Bering and Chukchi seas in an attempt to better understand what happens to land and marine organic matter when it enters this continental shelf ecosystem.

  18. Inland and coastal waters

    NASA Astrophysics Data System (ADS)

    Mouw, Colleen; Greb, Steven

    2012-09-01

    Workshop for Remote Sensing of Coastal and Inland Waters;Madison, Wisconsin, 20-22 June 2012 Coastal and inland water bodies, which have great value for recreation, food supply, commerce, transportation, and human health, have been experiencing external pressure from direct human activities and climate change. Given their societal and economic value, understanding issues of water quality, water quantity, and the impact of environmental change on the ecological and biogeochemical functioning of these water bodies is of interest to a broad range of communities. Remote sensing offers one of the most spatially and temporally comprehensive tools for observing these waters. While there has been some success with remotely observing these water bodies, many challenges still remain, including algorithm performance, atmospheric correction, the relationships between optical properties and biogeochemical parameters, sufficient spatial and spectral resolution, and a lack of uncertainty estimates over the wide range of environmental conditions encountered across these coastal and inland water bodies.

  19. NATIONAL COASTAL CONDITION REPORT II

    EPA Science Inventory

    Coastal waters in the US include estuaries, coastalwetlands, coral reefs, mangrove and kep forests, seagrass meadows, and upwelling areas. Critical coastal habitats provide spawning grounds, nurseries, shelter, and food for finfish, shellfish, birds, and other wildlife. the nat...

  20. The coastal theme of the integrated global observing strategy (IGOS)

    NASA Astrophysics Data System (ADS)

    Digiacomo, P. M.; Talaue-McManus, L.; Igos Coastal Theme Team

    A proposal for a Coastal Theme of the Integrated Global Observing Strategy (IGOS; http://www.igospartners.org/) was approved at the 10th IGOS Partners Meeting in June 2003. The goal of the IGOS Coastal Theme is to develop a strategy for integrated global observations that will provide improved understanding of earth system variability and change in the coastal zone, with a particular emphasis on propagation of change and variability across the land-sea interface. Specific objectives of the IGOS Coastal Theme are to: 1) Specify user driven requirements for in situ and remote observations (e.g., variables to be measured, appropriate time-space scales of observations, platforms/sensors to be used) of the linked terrestrial-marine-atmospheric environments of the coastal zone and the associated requirements for data management and models; 2) Evaluate current and projected observation capabilities in terms of the extent to which they meet these requirements, identifying gaps, redundancies, and activities that need to be strengthened; 3) Establish a framework to integrate observations (in situ and remote), particularly across boundaries, as time-space scales of variability differ dramatically between the terrestrial side and the marine side of the coastal zone; 4) Incorporate the approved IGOS Coral Reef Sub-Theme. In this overall context the IGOS Coastal Theme will help identify gaps in satellite observations and reduce unnecesary duplication; strengthen the linkage between in situ and space-based observations for coastal research and management applications; assist in the design and implementation of Global Observing Systems with coastal components, particularly GOOS and GTOS; stimulate building of long-term coastal data sets by identifying continuity needs; and enable improved products and services by facilitating the integration of coastal data across the land-ocean margins. A Coastal Theme Report addressing the above issues is presently being developed and will be

  1. The Coastal Theme of the Integrated Global Observing Strategy (IGOS)

    NASA Astrophysics Data System (ADS)

    Digiacomo, P. M.; Talaue-McManus, L.

    A proposal for a Coastal Theme of the Integrated Global Observing Strategy (IGOS; http://www.igospartners.org/) was approved at the 10th IGOS Partners Meeting in June 2003. The goal of the IGOS Coastal Theme is to develop a strategy for integrated global observations that will provide improved understanding of earth system variability and change in the coastal zone, with a particular emphasis on propagation of change and variability across the land-sea interface. Specific objectives of the IGOS Coastal Theme are to: 1) Specify user driven requirements for in situ and remote observations (e.g., variables to be measured, appropriate time-space scales of observations, platforms/sensors to be used) of the linked terrestrial-marine-atmospheric environments of the coastal zone and the associated requirements for data management and models; 2) Evaluate current and projected observation capabilities in terms of the extent to which they meet these requirements, identifying gaps, redundancies, and activities that need to be strengthened; 3) Establish a framework to integrate observations (in situ and remote), particularly across boundaries, as time-space scales of variability differ dramatically between the terrestrial side and the marine side of the coastal zone; 4) Incorporate the approved IGOS Coral Reef Sub-Theme. In this overall context the IGOS Coastal Theme will help identify gaps in satellite observations and reduce unnecesary duplication; strengthen the linkage between in situ and space-based observations for coastal research and management applications; assist in the design and implementation of Global Observing Systems with coastal components, particularly GOOS and GTOS; stimulate building of long-term coastal data sets by identifying continuity needs; and enable improved products and services by facilitating the integration of coastal data across the land-ocean margins. A Coastal Theme Report addressing the above issues is presently being developed and will be

  2. Coastal laws strike a balance

    SciTech Connect

    Dennison, M.S.

    1993-04-01

    Although the coastal zone comprises less than 10% of the nation`s land mass, more than 75% of the population lives within 50 miles of coastal areas. Commercial enterprises, including manufacturing facilities, industrial plants, resort hotels and marinas, are built in coastal areas along with the usual beachfront homes condominiums. These enterprises can adversely impact coastal environment through pollution-generation activities. Government regulators have sought to curtail activities that give rise to pollution.

  3. The emerging role of lidar remote sensing in coastal research and resource management

    USGS Publications Warehouse

    Brock, John C.; Purkis, Samuel J.

    2009-01-01

    Knowledge of coastal elevation is an essential requirement for resource management and scientific research. Recognizing the vast potential of lidar remote sensing in coastal studies, this Special Issue includes a collection of articles intended to represent the state-of-the-art for lidar investigations of nearshore submerged and emergent ecosystems, coastal morphodynamics, and hazards due to sea-level rise and severe storms. Some current applications for lidar remote sensing described in this Special Issue include bluegreen wavelength lidar used for submarine coastal benthic environments such as coral reef ecosystems, airborne lidar used for shoreline mapping and coastal change detection, and temporal waveform-resolving lidar used for vegetation mapping.

  4. GREATEM survey in coastal area

    NASA Astrophysics Data System (ADS)

    Abd allah, S.; Mogi, T.; Femonko, E.

    2014-12-01

    To determine the electric-resistivity structure in coastal areas, airborne electromagnetic (AEM) surveys have been used many places. These results showed AEM can reveal seawater depth, sediment thickness, and depth to bedrock. However, until now, AEM could only reveal the resistivity structure to a depth of ˜200 m in coastal areas. Conventional AEM, using an airborne inductive source limits the depth of exploration because the presence of a conductor, such as saline surface water, decreases the penetration of the AEM signal. In order to enhance the depth of exploration, we used a grounded electrical source aligned parallel to the coast line and towed a magnetic receiver in the air. The method, called grounded-electrical-source airborne transient electromagnetics, or GREATEM (Mogi et al., 1998), should enhance survey depth in coastal areas, since this method galvanically injects electric current into the ground. The method has increased the depth of exploration to 800 m in on-shore areas (Mogi et al., 2009, Ito et al. 2014). We have carried out a GREATEM survey at Kujukuri beach in central Japan, where an alluvial plain is dominated by sedimentary rocks and shallow water. Another GREATEM survey was performed at northwestern Awaji Island, where granitic rocks crop out onshore. In these studies, we faced issues how do we evaluate an effect of sea water on the data. To circumvent this problem, we used a three-dimensional (3D) electromagnetic (EM) modeling scheme based on the staggered-grid finite-difference (FD) method (Fomenko and Mogi, 2002) to study the effects of oceanic saltwater on GREATEM survey data at coastal areas. The models consisted of two adjacent layers where sea is a conductive thin sheet placed on top of a unifirm half space ( 100 Ohm-m). Then, we performed numerical forward modeling using the SFD method to generate a 3-D resistivity structure models from GREATEM field survey data at both of Kujukuri beach and the Nojima fault. As a result, we have

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  6. Placer and lode platinum-group minerals in south Kalimantan, Indonesia: evidence for derivation from Alaskan-type ultramafic intrusions

    USGS Publications Warehouse

    Zientek, M.L.

    1992-01-01

    Platinum-group minerals occur in significant proportions in placer deposits in several localities in South Kalimantan. They consist of Pt-Fe alloy that may be intergrown with or contain inclusions of Ir-Os-Ru alloy, laurite and chromite. Alluvial PGM found along Sungai Tambanio are in part derived from chromatite schlieren in dunitic bodies intruded into clinopyroxene cumulates that may be part of an Alaskan-type ultramafic complex. A chromitite schlieren in serpentinite from one of these dunitic bodies is anomalous in PGE. The chondrite-normalized PGE pattern for this rock, pan concentrates from this area, and PGM concentrates from diamond-Au-PGM placer deposits have an "M'-shaped pattern enriched in Ir and Pt that is typical of PGE-mineralization associated with Alaskan-type ultramafic complexes. -Authors

  7. Utility of a Work Process Classification System for characterizing non-fatal injuries in the Alaskan commercial fishing industry

    PubMed Central

    Syron, Laura N.; Lucas, Devin L.; Bovbjerg, Viktor E.; Bethel, Jeffrey W.; Kincl, Laurel D.

    2016-01-01

    Background The US commercial fishing industry is hazardous, as measured by mortality data. However, research on non-fatal injuries is limited. Non-fatal injuries constitute the majority of occupational injuries and can result in workers’ lowered productivity and wages, lost quality of life, and disability. In the United States, a Work Process Classification System (WPCS) has previously been applied in Alaskan freezer-trawl and freezer-longline fleets to identify causes of injuries and specific hazards, but not to other fishing fleets. Objectives This descriptive epidemiologic study aimed to explore the application and modification of the WPCS in multiple Alaskan fleets, characterize non-fatal occupational injuries in these fleets, and identify work processes that could be targeted for further investigation and future injury prevention efforts. Design Traumatic, non-fatal injuries on-board Alaskan commercial fishing vessels were identified through United States Coast Guard investigative reports. Characteristics of injuries, as well as worker characteristics, were analysed. Injuries were coded using the WPCS. Results We successfully utilized the WPCS to code non-fatal injury cases (n = 136). The most frequent main work processes associated with non-fatal injuries included: on-board trawlers, handling frozen fish and processing the catch; on-board vessels using pot/trap gear, handling the gear and shooting/setting the gear; on-board longliners, traffic on board and hauling the gear; and on-board processor vessels, processing the catch, other work with the catch, and handling frozen fish. Conclusions The study confirmed that a WPCS can be applied to multiple Alaskan fleets to identify hazardous tasks. Hazards were unique for each vessel gear type. Future injury prevention efforts should target work processes associated with the most frequent and most severe injuries. Future studies should establish time estimates for work processes in order to determine risk

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

    USGS Publications Warehouse

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

    2015-01-01

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

  9. CHAPTER 7: COASTAL ZONES.

    EPA Science Inventory

    The Mid-Atlantic's coastal areas, especially the Chesapeake Bay, Delaware Bay, and Albemarle/Pamlico Sounds (Figure 3), have important aesthetic and economic values. In Delaware, for example, Parsons and Powell (1998) estimated that $90,000 of the value of a $200,000 home along t...

  10. MANAGING COASTAL DATA

    EPA Science Inventory

    To answer broad-scale questions on environmental conditions, the Environmental Monitoring and Assessment Program (EMAP) and its partners have collected estuarine and coastal data from hundreds of stations along the coasts of the continental United States. Types of data include w...

  11. COASTAL EMAP PROJECT

    EPA Science Inventory

    Several state and federal agencies are collecting monitoring data. One of the goals of the project is to assist the states in the implementation of their statewide coastal monitoring strategy by dealing with issues of statewide data comparability and information management. The ...

  12. Model for Coastal Restoration

    SciTech Connect

    Thom, Ronald M.; Judd, Chaeli

    2007-07-27

    Successful restoration of wetland habitats depends on both our understanding of our system and our ability to characterize it. By developing a conceptual model, looking at different spatial scales and integrating diverse data streams: GIS datasets and NASA products, we were able to develop a dynamic model for site prioritization based on both qualitative and quantitative relationships found in the coastal environment.

  13. Application of remote sensors in coastal zone observations

    NASA Technical Reports Server (NTRS)

    Caillat, J. M.; Elachi, C.; Brown, W. E., Jr.

    1975-01-01

    A review of processes taking place along coastlines and their biological consideration led to the determination of the elements which are required in the study of coastal structures and which are needed for better utilization of the resources from the oceans. The processes considered include waves, currents, and their influence on the erosion of coastal structures. Biological considerations include coastal fisheries, estuaries, and tidal marshes. Various remote sensors were analyzed for the information which they can provide and sites were proposed where a general ocean-observation plan could be tested.

  14. Review of coastal-area aquifers in Africa

    NASA Astrophysics Data System (ADS)

    Steyl, G.; Dennis, I.

    2010-02-01

    The coastal aquifer systems of Africa are comprised of various geological formations. These aquifer systems consist of either folded, continental or alluvial deposits. Groundwater resource availability along the coastal areas of Africa is briefly reported and the current state of seawater intrusion has been summarized. A select number of notable examples are given to highlight the effect of saline intrusion on coastal development of cities and regional aquifers. The role of conflict resolution is briefly discussed, as well as management approaches, which include monitoring of contamination and governmental accountability. Regional cooperation is presented as a method of ensuring a sustainable water resource in an area, as well as strengthening social and political alliances.

  15. Transport and reaction of heavy metals in Alaskan fjord estuaries. Annual report, July 1, 1980-May 31, 1981

    SciTech Connect

    Burrell, D.C.

    1981-05-01

    The program investigates the potential effects of energy-related chemical pollution in Alaskan fjords. The long-term objective is to understand the chemical, physical, and biological processes responsible for the transport and reaction of heavy metals in these sub-arctic estuaries. The physical circulation and mixing processes, the nature and reactions of terrigenous organics and particulate sediment within the mixing zone, and aspects of the basin sediment oxygen, carbon and nutrient budgets in addition to study of individual metals are investigated. Mainly copper, iron and manganese are being studied since these provide information on physical-chemical processes common to, or greatly affecting, a much wider range of metals. The bulk of the Work completed section of this report refers to Resurrection Bay, a southcentral Alaskan fjord. The Work in progress reported here outlines recent investigations in Boca de Quadra, a southeast Alaskan fjord-estuary. We are here investigating deep and surface water circulation; oxygen, carbon and nutrient budgets; the compositions, reaction and flux of particulate sediment; and organic-heavy metal associations in the freshwater and in the mixing zone.

  16. Coastal hazards: hurricanes, tsunamis, coastal erosion

    USGS Publications Warehouse

    Vandas, Stephen; Mersfelder, Lynne; Farrar, Frank, (artist); France, Rigoberto Guardado, (translator); Yajimovich, Oscar Efraín González; Muñoz, Aurora R.; Rivera, María del C.

    1996-01-01

    Oceans are the largest geographic feature on the surface of the Earth, covering approximately 70% of the planet's surface. As a result, oceans have a tremendous impact on the Earth, its climate, and its inhabitants. The coast or shoreline is the boundary between ocean environments and land habitats. By the year 2025, it is estimated that approximately two-thirds of the world's population will be living within 200 kilometers of a coast. In many ways, we treat the coast just like any other type of land area, as a safe and stable place to live and play. However, coastal environments are dynamic, and they constantly change in response to natural processes and to human activities.

  17. Inter-annual variability in Alaskan net ecosystem CO2 exchange

    NASA Astrophysics Data System (ADS)

    Luus, Kristina; Lindaas, Jakob; Commane, Roisin; Euskirchen, Eugenie; Oechel, Walter; Zona, Donatella; Chang, Rachel; Kelly, Richard; Miller, Charles; Wofsy, Steven; Lin, John

    2015-04-01

    The high-latitude biospheric carbon cycle's responses to climate change are predicted to have an important role in determining future atmospheric concentrations of CO2. In response to warming soil and air temperatures, Arctic wetlands have been observed to increase rates of both soil C efflux and vegetation C uptake through photosynthesis. However, insights into the regional-scale consequences of these processes for net C uptake have been limited by the large uncertainties existing in process-based model estimates of Arctic net ecosystem CO2 exchange (NEE). The Polar Vegetation Photosynthesis and Respiration Model (PolarVPRM) instead provides data-driven, satellite-based estimates of high-latitude NEE, using a framework which specifically accounts for polar influences on NEE. PolarVPRM calculates NEE as the sum of respiration (R) and gross ecosystem exchange (GEE), where GEE refers to the light-dependent portion of NEE: NEE= -GEE + R. Meteorological inputs for PolarVPRM are provided by the North American Regional Reanalysis (NARR), and land surface inputs are acquired from the Moderate Resolution Imaging Spectroradiometer (MODIS). Growing season R is calculated from air temperature, and subnivean R is calculated according to soil temperature. GEE is calculated according to shortwave radiation, air temperature, and MODIS-derived estimates of soil moisture and vegetation biomass. Previously, model validation has indicated that PolarVPRM showed reasonably good agreement with eddy covariance observations at nine North American Arctic sites, of which three were used for calibration purposes. For this project, PolarVPRM NEE was calculated year-round across Alaska at a three-hourly temporal resolution and a spatial resolution of 1 6°×1 4° (latitude × longitude). The objective of this work was to gain insight into inter-annual variability in Alaskan NEE, R and GEE, and an understanding of which meteorological and land surface drivers account for these observed patterns

  18. Black and Brown Bear Activity at Selected Coastal Sites in Glacier Bay National Park and Preserve, Alaska: A Preliminary Assessment Using Noninvasive Procedures

    USGS Publications Warehouse

    Partridge, Steve; Smith, Tom; Lewis, Tania

    2009-01-01

    A number of efforts in recent years have sought to predict bear activity in various habitats to minimize human disturbance and bear/human conflicts. Alaskan coastal areas provide important foraging areas for bears (Ursus americanus and U. arctos), particularly following den emergence when there may be no snow-free foraging alternatives. Additionally, coastal areas provide important food items for bears throughout the year. Glacier Bay National Park and Preserve (GLBA) in southeastern Alaska has extensive coastal habitats, and the National Park Service (NPS) has been long interested in learning more about the use of these coastal habitats by bears because these same habitats receive extensive human use by park visitors, especially kayaking recreationists. This study provides insight regarding the nature and intensity of bear activity at selected coastal sites within GLBA. We achieved a clearer understanding of bear/habitat relationships within GLBA by analyzing bear activity data collected with remote cameras, bear sign mapping, scat collections, and genetic analysis of bear hair. Although we could not quantify actual levels of bear activity at study sites, agreement among measures of activity (for example, sign counts, DNA analysis, and video record) lends support to our qualitative site assessments. This work suggests that habitat evaluation, bear sign mapping, and periodic scat counts can provide a useful index of bear activity for sites of interest.

  19. Coastal ocean forecasting systems in Europe

    NASA Astrophysics Data System (ADS)

    Dugan, John

    During my tour as the liaison oceanographer at the Office of Naval Research's European branch, I conducted a focused study of coastal ocean forecasting systems. This study is of direct interest to ONR because of an increased interest in the coastal zone and to the civilian U.S. oceanographic community because of numerous problems in the coastal zone that could be alleviated with an operational forecasting system. The Europeans have a long history of excellent research and developmental work in this area. The Europeans' distinguished history in coastal ocean forecasting is due in part to their strong dependence on the sea. However, the original motivation for these systems was the recognition early in this century that weather conditions were responsible for damaging storm surges around the periphery of the North Sea and that science could predict these catastrophic floods. Forecasting systems called tide-surge prediction systems, which provide warnings of impending flood conditions, were designed and constructed and are operational in the various meteorological centers of the nations surrounding the North Sea. Over time, the services have been extended to provide forecasts of ocean waves, water depth for navigation, and currents for a large customer base. These systems now are being extended further into the three-dimensional domain that is required for management of problems associated with water quality, pollution, and aquaculture and fisheries interests.

  20. The Coastal Ocean Prediction Systems program: Understanding and managing our coastal ocean. Volume 1: Strategic summary

    SciTech Connect

    Not Available

    1990-05-15

    The proposed COPS (Coastal Ocean Prediction Systems) program is concerned with combining numerical models with observations (through data assimilation) to improve our predictive knowledge of the coastal ocean. It is oriented toward applied research and development and depends upon the continued pursuit of basic research in programs like COOP (Coastal Ocean Processes); i.e., to a significant degree it is involved with ``technology transfer`` from basic knowledge to operational and management applications. This predictive knowledge is intended to address a variety of societal problems: (1) ship routing, (2) trajectories for search and rescue operations, (3) oil spill trajectory simulations, (4) pollution assessments, (5) fisheries management guidance, (6) simulation of the coastal ocean`s response to climate variability, (7) calculation of sediment transport, (8) calculation of forces on structures, and so forth. The initial concern is with physical models and observations in order to provide a capability for the estimation of physical forces and transports in the coastal ocean. For all these applications, there are common needs for physical field estimates: waves, tides, currents, temperature, and salinity, including mixed layers, thermoclines, fronts, jets, etc. However, the intent is to work with biologists, chemists, and geologists in developing integrated multidisciplinary prediction systems as it becomes feasible to do so. From another perspective, by combining observations with models through data assimilation, a modern approach to monitoring is provided through whole-field estimation.

  1. Thermal Spray Coatings for Coastal Infrastructure

    SciTech Connect

    Holcomb, G.R.; Covino, BernardS. Jr.; Cramer, S.D.; Bullard, S.J.

    1997-11-01

    Several protection strategies for coastal infrastructure using thermal-spray technology are presented from research at the Albany Research Center. Thermal-sprayed zinc coatings for anodes in impressed current cathodic protection systems are used to extend the service lives of reinforced concrete bridges along the Oregon coast. Thermal-sprayed Ti is examined as an alternative to the consumable zinc anode. Sealed thermal-sprayed Al is examined as an alternative coating to zinc dust filled polyurethane paint for steel structures.

  2. ENERGY IN THE PACIFIC COASTAL ZONE DOES D.O.E. HAVE A ROLE?

    SciTech Connect

    Ritschard, Ronald L.; Haven, Kendall F.; Cherniss, Jennifer

    1980-09-01

    This paper addresses the energy-related acti ties in the Pacific Coastal Zone within the context of the absence of a coastal-specific energy policy. First, the present and projected coastal energy activities are described in order to establish a perspective of the importance of the coastal zone to energy development. transport, and use. Next, the state and federal decision-making processes relevant to coastal energy activities are summarized for the purpose of defining the institutional framework that has been constructed to respond to coastal energy issues. Finally, the functional areas not currently being adequately addressed are identified; and an associate role, which ensures both comprehensive evaluation and sound development of regional coastal energy resources, is defined for the DOE Office of Environment.

  3. Catalog of earthquake hypocenters at Alaskan volcanoes: January 1 through December 31, 2002

    USGS Publications Warehouse

    Dixon, James P.; Stihler, Scott D.; Power, John A.; Tytgat, Guy; Moran, Seth C.; Sánchez, John; Estes, Steve; McNutt, Stephen R.; Paskievitch, John

    2003-01-01

    The Alaska Volcano Observatory (AVO), a cooperative program of the U.S. Geological Survey, the Geophysical Institute of the University of Alaska Fairbanks, and the Alaska Division of Geological and Geophysical Surveys, has maintained seismic monitoring networks at historically active volcanoes in Alaska since 1988 (Power and others, 1993; Jolly and others, 1996; Jolly and others, 2001; Dixon and others, 2002). The primary objectives of this program are the seismic monitoring of active, potentially hazardous, Alaskan volcanoes and the investigation of seismic processes associated with active volcanism. This catalog presents the basic seismic data and changes in the seismic monitoring program for the period January 1, 2002 through December 31, 2002. Appendix G contains a list of publications pertaining to seismicity of Alaskan volcanoes based on these and previously recorded data. The AVO seismic network was used to monitor twenty-four volcanoes in real time in 2002. These include Mount Wrangell, Mount Spurr, Redoubt Volcano, Iliamna Volcano, Augustine Volcano, Katmai Volcanic Group (Snowy Mountain, Mount Griggs, Mount Katmai, Novarupta, Trident Volcano, Mount Mageik, Mount Martin), Aniakchak Crater, Mount Veniaminof, Pavlof Volcano, Mount Dutton, Isanotski Peaks, Shishaldin Volcano, Fisher Caldera, Westdahl Peak, Akutan Peak, Makushin Volcano, Great Sitkin Volcano, and Kanaga Volcano (Figure 1). Monitoring highlights in 2002 include an earthquake swarm at Great Sitkin Volcano in May-June; an earthquake swarm near Snowy Mountain in July-September; low frequency (1-3 Hz) tremor and long-period events at Mount Veniaminof in September-October and in December; and continuing volcanogenic seismic swarms at Shishaldin Volcano throughout the year. Instrumentation and data acquisition highlights in 2002 were the installation of a subnetwork on Okmok Volcano, the establishment of telemetry for the Mount Veniaminof subnetwork, and the change in the data acquisition system to

  4. Catalog of earthquake hypocenters at Alaskan volcanoes: January 1, 2000 through December 31, 2001

    USGS Publications Warehouse

    Dixon, James P.; Stihler, Scott D.; Power, John A.; Tytgat, Guy; Estes, Steve; Moran, Seth C.; Paskievitch, John; McNutt, Stephen R.

    2002-01-01

    The Alaska Volcano Observatory (AVO), a cooperative program of the U.S. Geological Survey, the Geophysical Institute of the University of Alaska Fairbanks, and the Alaska Division of Geological and Geophysical Surveys, has maintained seismic monitoring networks at potentially active volcanoes in Alaska since 1988 (Power and others, 1993; Jolly and others, 1996; Jolly and others, 2001). The primary objectives of this program are the seismic surveillance of active, potentially hazardous, Alaskan volcanoes and the investigation of seismic processes associated with active volcanism. This catalog reflects the status and evolution of the seismic monitoring program, and presents the basic seismic data for the time period January 1, 2000, through December 31, 2001. For an interpretation of these data and previously recorded data, the reader should refer to several recent articles on volcano related seismicity on Alaskan volcanoes in Appendix G. The AVO seismic network was used to monitor twenty-three volcanoes in real time in 2000-2001. These include Mount Wrangell, Mount Spurr, Redoubt Volcano, Iliamna Volcano, Augustine Volcano, Katmai Volcanic Group (Snowy Mountain, Mount Griggs, Mount Katmai, Novarupta, Trident Volcano, Mount Mageik, Mount Martin), Aniakchak Crater, Pavlof Volcano, Mount Dutton, Isanotski Peaks, Shishaldin Volcano, Fisher Caldera, Westdahl Peak, Akutan Peak, Makushin Volcano, Great Sitkin Volcano, and Kanaga Volcano (Figure 1). AVO located 1551 and 1428 earthquakes in 2000 and 2001, respectively, on and around these volcanoes. Highlights of the catalog period (Table 1) include: volcanogenic seismic swarms at Shishaldin Volcano between January and February 2000 and between May and June 2000; an eruption at Mount Cleveland between February and May 2001; episodes of possible tremor at Makushin Volcano starting March 2001 and continuing through 2001, and two earthquake swarms at Great Sitkin Volcano in 2001. This catalog includes: (1) earthquake origin

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

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

    SciTech Connect

    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

  7. Catalog of earthquake hypocenters at Alaskan volcanoes: January 1, 2000 through December 31, 2001

    USGS Publications Warehouse

    Dixon, James P.; Stihler, Scott D.; Power, John A.; Tytgat, Guy; Estes, Steve; Moran, Seth C.; Paskievitch, John; McNutt, Stephen R.

    2002-01-01

    The Alaska Volcano Observatory (AVO), a cooperative program of the U.S. Geological Survey, the Geophysical Institute of the University of Alaska Fairbanks, and the Alaska Division of Geological and Geophysical Surveys, has maintained seismic monitoring networks at potentially active volcanoes in Alaska since 1988 (Power and others, 1993; Jolly and others, 1996; Jolly and others, 2001). The primary objectives of this program are the seismic surveillance of active, potentially hazardous, Alaskan volcanoes and the investigation of seismic processes associated with active volcanism. This catalog reflects the status and evolution of the seismic monitoring program, and presents the basic seismic data for the time period January 1, 2000, through December 31, 2001. For an interpretation of these data and previously recorded data, the reader should refer to several recent articles on volcano related seismicity on Alaskan volcanoes in Appendix G.The AVO seismic network was used to monitor twenty-three volcanoes in real time in 2000-2001. These include Mount Wrangell, Mount Spurr, Redoubt Volcano, Iliamna Volcano, Augustine Volcano, Katmai Volcanic Group (Snowy Mountain, Mount Griggs, Mount Katmai, Novarupta, Trident Volcano, Mount Mageik, Mount Martin), Aniakchak Crater, Pavlof Volcano, Mount Dutton, Isanotski Peaks, Shishaldin Volcano, Fisher Caldera, Westdahl Peak, Akutan Peak, Makushin Volcano, Great Sitkin Volcano, and Kanaga Volcano (Figure 1). AVO located 1551 and 1428 earthquakes in 2000 and 2001, respectively, on and around these volcanoes.Highlights of the catalog period (Table 1) include: volcanogenic seismic swarms at Shishaldin Volcano between January and February 2000 and between May and June 2000; an eruption at Mount Cleveland between February and May 2001; episodes of possible tremor at Makushin Volcano starting March 2001 and continuing through 2001, and two earthquake swarms at Great Sitkin Volcano in 2001.This catalog includes: (1) earthquake origin times

  8. Data assimilative hindcast of the Gulf of Maine coastal circulation

    NASA Astrophysics Data System (ADS)

    He, Ruoying; McGillicuddy, Dennis J.; Lynch, Daniel R.; Smith, Keston W.; Stock, Charles A.; Manning, James P.

    2005-10-01

    A data assimilative model hindcast of the Gulf of Maine (GOM) coastal circulation during an 11 day field survey in early summer 2003 is presented. In situ observations include surface winds, coastal sea levels, and shelf hydrography as well as moored and shipboard acoustic Doppler D current profiler (ADCP) currents. The hindcast system consists of both forward and inverse models. The forward model is a three-dimensional, nonlinear finite element ocean circulation model, and the inverse models are its linearized frequency domain and time domain counterparts. The model hindcast assimilates both coastal sea levels and ADCP current measurements via the inversion for the unknown sea level open boundary conditions. Model skill is evaluated by the divergence of the observed and modeled drifter trajectories. A mean drifter divergence rate (1.78 km d-1) is found, demonstrating the utility of the inverse data assimilation modeling system in the coastal ocean setting. Model hindcast also reveals complicated hydrodynamic structures and synoptic variability in the GOM coastal circulation and their influences on coastal water material property transport. The complex bottom bathymetric setting offshore of Penobscot and Casco bays is shown to be able to generate local upwelling and downwelling that may be important in local plankton dynamics.

  9. Corrosion prevention of Oregon's reinforced coastal bridges

    SciTech Connect

    Bullard, Sophie J.; Cramer, Stephen D.; Covino, Bernard S., Jr.; Holcomb, Gordon R.; Ziomek-Moroz, Margaret; Cryer. C.B; Gallardo, M. L.

    2004-06-01

    The Oregon Department of Transportation (Oregon DOT) maintains more than 120 coastal bridges; many are reinforced concrete structures over 15 m (50 ft) in length. Twelve of these bridges are historic structures. Oregon DOT is concerned about the ongoing deterioration of these bridges, rising maintenance and repair costs, and the need to protect Oregon’s large investment in coastal bridges. Over 80,000 m2 (850,000 ft2) of coastal bridge surface have been repaired and protected from further chloride-induced corrosion damage by using conductive coating anodes. Most of the anode area is thermal-sprayed (TS) Zn. Other anode materials include TS Ti, Zn-hydrogel, and conductive carbon paint. TS Zn anodes are estimated to have a service life exceeding 25 years but exhibit increasing anode polarization with age. Catalyzed TS Ti anodes develop no significant anode polarization and have exhibited stable long-term performance over 8 years of service. Galvanic Zn-hydrogel anodes produce a stable protection current with no evidence of aging effects over 6 years of service. The conductive carbon paint anode operates at a low anode current density and consumption rate with a low rate of acidification at the anode-concrete interface, which has contributed to a stable protection current over 17 years of service.

  10. Simulating decadal coastal morphodynamics

    NASA Astrophysics Data System (ADS)

    Nicholls, Robert J.; French, Jon R.; van Maanen, Barend

    2016-03-01

    Coastal geomorphic systems provide many services of key importance to humankind, including protection from flood and erosion hazards, diverse habitats and amenity values (Agardy et al., 2005; Jones et al., 2011). However, these systems are widely undergoing degradation that can be substantially attributed to the cumulative direct and indirect effects of human interference. Declining sediment inputs and throughputs are frequently a factor driving a shift towards progressive coastal erosion (Valiela, 2006; Nicholls et al., 2007). Such sediment starved systems have reduced resilience and are further threatened by human-induced climate change, not only due to accelerated sea-level rise, but also through possible shifts in wave and surge climate (Wong et al., 2014).

  11. Coastal Research Imaging Spectrometer

    NASA Technical Reports Server (NTRS)

    Lucey, Paul G.; Williams, Timothy; Horton, Keith A.

    2002-01-01

    The Coastal Research Imaging Spectrometer (CRIS) is an airborne remote-sensing system designed specifically for research on the physical, chemical, and biological characteristics of coastal waters. The CRIS includes a visible-light hyperspectral imaging subsystem for measuring the color of water, which contains information on the biota, sediment, and nutrient contents of the water. The CRIS also includes an infrared imaging subsystem, which provides information on the temperature of the water. The combination of measurements enables investigation of biological effects of both natural and artificial flows of water from land into the ocean, including diffuse and point-source flows that may contain biological and/or chemical pollutants. Temperature is an important element of such measurements because temperature contrasts can often be used to distinguish among flows from different sources: for example, a sewage outflow could manifest itself in spectral images as a local high-temperature anomaly.

  12. Wind stress: Which formulation for coastal applications?

    NASA Astrophysics Data System (ADS)

    Brown, Jenny; Mercier, Francois; Amoudry, Laurent; Souza, Alejandro

    2013-04-01

    surface stress due to the 10 m wind components. In this coastal application a 180 m Liverpool Bay model is nested such that the tide-surge and baroclinic influence from the European Continental Shelf and more locally within the Irish Sea, forces the boundaries. The full CORE bulk formulae includes: air temperature, relative humidity, cloud cover, atmospheric pressure and surface wind stress, to represent the transfer of heat and momentum fluxes across the atmosphere-ocean boundary in addition to the inverse barometer effect. This set up along with riverine inputs allows a realistic barotropic-baroclinic simulation of the circulation within the study area. The full CORE bulk formula is initially used to represent the complete atmospheric forcing; a second simulation then replaces the wind stress parameterisation within the CORE bulk formulae with that of the Charnock parameterisation. More accurate coastal circulation is generated using the Charnock method for surface wind stress. Problems with the CORE bulk formulae are identified with offshore wind conditions. Our conclusion is that the Charnock parameterisation produces better surge and coastal wind driven currents.

  13. Coastal eutrophication as a driver of salt marsh loss.

    PubMed

    Deegan, Linda A; Johnson, David Samuel; Warren, R Scott; Peterson, Bruce J; Fleeger, John W; Fagherazzi, Sergio; Wollheim, Wilfred M

    2012-10-18

    Salt marshes are highly productive coastal wetlands that provide important ecosystem services such as storm protection for coastal cities, nutrient removal and carbon sequestration. Despite protective measures, however, worldwide losses of these ecosystems have accelerated in recent decades. Here we present data from a nine-year whole-ecosystem nutrient-enrichment experiment. Our study demonstrates that nutrient enrichment, a global problem for coastal ecosystems, can be a driver of salt marsh loss. We show that nutrient levels commonly associated with coastal eutrophication increased above-ground leaf biomass, decreased the dense, below-ground biomass of bank-stabilizing roots, and increased microbial decomposition of organic matter. Alterations in these key ecosystem properties reduced geomorphic stability, resulting in creek-bank collapse with significant areas of creek-bank marsh converted to unvegetated mud. This pattern of marsh loss parallels observations for anthropogenically nutrient-enriched marshes worldwide, with creek-edge and bay-edge marsh evolving into mudflats and wider creeks. Our work suggests that current nutrient loading rates to many coastal ecosystems have overwhelmed the capacity of marshes to remove nitrogen without deleterious effects. Projected increases in nitrogen flux to the coast, related to increased fertilizer use required to feed an expanding human population, may rapidly result in a coastal landscape with less marsh, which would reduce the capacity of coastal regions to provide important ecological and economic services. PMID:23075989

  14. Coastal Aquifer Response to Environmental Change - Implications for Future Projections

    NASA Astrophysics Data System (ADS)

    Post, V.

    2014-12-01

    Coastal aquifers are important resources for water supply, and are increasingly stressed by population increase and the growing water demand for irrigation and other uses. Concern exists that these current pressures will be compunded by the adverse impacts of future environmental change, in particular sea-level rise. Numerous studies have investigated the effect of the expected sea-level rise durring the 21st century on the salintiy distribution in coastal groundwater systems. In many of these studies, the predicted changes due to an increase in sea level are typically seen as a departure from a steady-state situation. But many other studies have provided abundant evidence that groundwater systems in coastal areas are not in equilibrium with the present-day boundary conditions, i.e., coastline configuration and climate. This is borne out by, for example, the salinity distribution of groundwater, which does not obey the classical configuration of an intruded wedge of seawater extending inland from the coastline. This paper will argue that coastal aquifers systems are in a continuous state of transition. The relevance of future environmental change within the context of long-term trends will be discussed and exemplified by case studies of coastal aquifers in different parts of the world. It will be argued that the conceptualization of coastal groundwater systems, and in particular the connection between their onshore and offshore parts, is a major source of uncertainty in studies that aim to quantify the impact of sea-level rise on coastal groundwater resources.

  15. Prioritising coastal zone management issues through fuzzy cognitive mapping approach.

    PubMed

    Meliadou, Aleka; Santoro, Francesca; Nader, Manal R; Dagher, Manale Abou; Al Indary, Shadi; Salloum, Bachir Abi

    2012-04-30

    Effective public participation is an essential component of Integrated Coastal Zone Management implementation. To promote such participation, a shared understanding of stakeholders' objectives has to be built to ultimately result in common coastal management strategies. The application of quantitative and semi-quantitative methods involving tools such as Fuzzy Cognitive Mapping is presently proposed for reaching such understanding. In this paper we apply the Fuzzy Cognitive Mapping tool to elucidate the objectives and priorities of North Lebanon's coastal productive sectors, and to formalize their coastal zone perceptions and knowledge. Then, we investigate the potential of Fuzzy Cognitive Mapping as tool for support coastal zone management. Five round table discussions were organized; one for the municipalities of the area and one for each of the main coastal productive sectors (tourism, industry, fisheries, agriculture), where the participants drew cognitive maps depicting their views. The analysis of the cognitive maps showed a large number of factors perceived as affecting the current situation of the North Lebanon coastal zone that were classified into five major categories: governance, infrastructure, environment, intersectoral interactions and sectoral initiatives. Furthermore, common problems, expectations and management objectives for all sectors were exposed. Within this context, Fuzzy Cognitive Mapping proved to be an essential tool for revealing stakeholder knowledge and perception and understanding complex relationships. PMID:22325583

  16. Aerial Photography as a Tool to Document Coastal Change Along Eroding Shorelines in Northern Alaska

    NASA Astrophysics Data System (ADS)

    Gibbs, A.; Richmond, B. M.; Nolan, M.

    2014-12-01

    Chronic and widespread coastal erosion along the northern coast of Alaska is threatening traditional lifestyles, sensitive ecosystems, energy and defense related infrastructure, and large tracts of Native Alaskan, State, and Federally managed land. Recent USGS historical shoreline position studies have documented shoreline change rates along most of northern Alaska for the period from 1947 to circa 2000. Rates vary from an erosional high of -18.6 m/yr along vulnerable bluffed coasts, to accretion up to +10.9 m/yr along prograding sand-rich coasts (average rate for entire study area is -1.4 m/yr). The historical analysis gives valuable information regarding long-term rates of change but does not provide details on the timing and processes driving the change. Oblique and vertical aerial photography contains valuable coastal information on such things as bluff failure mechanisms, presence or absence of shorefast ice, beach characteristics including erosional scarps and ice-push ridges, wrack lines produced during storm surge events, and habitat identification. Recent advances in digital photogrammetry applied to oblique aerial photography can be used to construct high quality DEMs at a relatively low cost. Repeat aerial surveys and resultant DEM construction serve as a potential monitoring tool that can be used to quantify volumetric change, and, if conducted frequently enough, provide insights into the mechanisms responsible for coastal change in the Arctic. We provide examples from a few selected sites in northern Alaska where oblique aerial photography has been used to better understand coastal change in remote and threatened areas.

  17. 76 FR 39857 - Alaska Coastal Management Program Withdrawal From the National Coastal Management Program Under...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-07

    ... National Oceanic Atmospheric Administration Alaska Coastal Management Program Withdrawal From the National Coastal Management Program Under the Coastal Zone Management Act (CZMA) AGENCY: Office of Ocean and Coastal Resource Management (OCRM), National Ocean Service (NOS), National Oceanic...

  18. Methane transport mechanisms and isotopic fractionation in emergent macrophytes of an Alaskan tundra lake

    NASA Technical Reports Server (NTRS)

    Chanton, Jeffrey P.; Martens, Christopher S.; Kelley, Cheryl A.; Crill, Patrick M.; Showers, William J.

    1992-01-01

    The stable carbon isotopic composition of methane associated with and emitted by the two dominant emergent macrophytes abundant in the many Alaskan tundra lakes, Carex rostrata and Arctophila fulva, is determined. The carbon isotopic composition of the methane was -58.6 +/- 0.5 (n=2) for Arctophila and -66.6 +/- 2.5 (n=6) for Carex. The methane emitted by these species is depleted in C-13 by 12 per mil for Arctophila and 18 per mil for Carex relative to methane withdrawn from plant stems 1-2 cm below the waterline. The results suggest more rapid transport of (C-12)H4 relative to (C-13)H4 through plants to the atmosphere. Plant stem methane concentrations ranged from 0.2 to 4.0 percent in Arctophila, with an isotopic composition of -46.1 +/- 4.3 percent (n=8). Carex stem methane concentrations ranged from 150 to 1200 ppm, with an isotopic composition of -48.3 +/- 1.4 per mil (n=3).

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

    USGS Publications Warehouse

    Griffiths, J.R.; Schindler, D.E.; Balistrieri, L.S.; Ruggerone, G.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. ?? 2011, by the American Society of Limnology and Oceanography, Inc.

  20. Establishment of a New, Cooperative ARM and AmeriFlux Site on the Alaskan North Slope

    NASA Astrophysics Data System (ADS)

    Billesbach, D. P.; Fischer, M. L.; Cook, D. R.; Torn, M. S.; Castanha, C.

    2011-12-01

    We report here on the establishment of a new research facility on the Alaskan North Slope. The experiment, located near Barrow, AK will be operated by the US Department of Energy (US DOE) as a permanent facility at the North Slope of Alaska (NSA) site of the Atmospheric Radiation Measurement (ARM) Climate Research Facility. The instrumentation at the site as well as on-going vegetation and soil measurements will also constitute the core data set for a new AmeriFlux site. Data will be made available through both the ARM and the AmeriFlux data centers. The experiment will be centered around an eddy covariance flux tower that will generated measurements of carbon dioxide, methane, water vapor, and energy fluxes. Additionally, surface radiation, meteorological, and soil instruments will provide ancillary data needed for gap filling, quality control, and climate quantification. Destructive and non-destructive sampling, according to the AmeriFlux biometric sampling protocols will quantify plant biomass, species, leaf area and nitrogen, and soil carbon stocks. Our goal is to assess both the impact that the Arctic costal region might have on the carbon cycle as well as climatic feedbacks that could affect this vulnerable ecosystem.

  1. Recent acceleration of biomass burning and carbon losses in Alaskan forests and peatlands

    USGS Publications Warehouse

    Turetsky, M.R.; Kane, E.S.; Harden, J.W.; Ottmar, R.D.; Manies, K.L.; Hoy, E.; Kasischke, E.S.

    2011-01-01

    Climate change has increased the area affected by forest fires each year in boreal North America. Increases in burned area and fire frequency are expected to stimulate boreal carbon losses. However, the impact of wildfires on carbon emissions is also affected by the severity of burning. How climate change influences the severity of biomass burning has proved difficult to assess. Here, we examined the depth of ground-layer combustion in 178 sites dominated by black spruce in Alaska, using data collected from 31 fire events between 1983 and 2005. We show that the depth of burning increased as the fire season progressed when the annual area burned was small. However, deep burning occurred throughout the fire season when the annual area burned was large. Depth of burning increased late in the fire season in upland forests, but not in peatland and permafrost sites. Simulations of wildfire-induced carbon losses from Alaskan black spruce stands over the past 60 years suggest that ground-layer combustion has accelerated regional carbon losses over the past decade, owing to increases in burn area and late-season burning. As a result, soils in these black spruce stands have become a net source of carbon to the atmosphere, with carbon emissions far exceeding decadal uptake.

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

    SciTech Connect

    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%.

  3. Possible connection between two Alaskan catastrophes occurring 25 yr apart (1964 and 1989)

    SciTech Connect

    Kvenvolden, K.A.; Carlson, P.R. ); Threlkeld, C.N.; Warden, A. )

    1993-09-01

    On March 24, 1989, the Exxon Valdez supertanker grounded on Bligh Reef, spilling North Slope crude oil into Prince William Sound, Alaska. Tracking the geochemical fate of this spilled oil has revealed, in addition to weathered products from the spill, minor oil residues on beaches from a distinctly different source. By using carbon isotopic compositions of whole-oil residues as a principal method of identification, we found that the [delta][sup +13]C values of Exxon Valdez oil (one sample) and its residues (eight samples from six islands) average [minus]29.3 0.1%. In contrast, the non-Exxon Valdez residues (15 samples from 12 localities) have an average [delta][sup 13]C value of [minus]23.8 [+-]0.1%. This tight distribution of carbon isotopic values suggestes a single event to explain the non-Exxon Valdez residues. This event likely was the Great Alaska Earthquake of March 27, 1964. This quake and the subsequent tsunami destroyed asphalt storage facilities at the old Valdez town site, spilling asphalt ([delta][sup +13]C = [minus]23.6%) into Port Valdez fjord. From there the asphalt apparently advanced south into the sound. Thus, the possible connection between two Alaskan catastrophes, separated by 25 yr, is found in the minor oil-like residues that continue to mark the two events on the beaches of Prince William Sound. 16 refs., 2 figs., 1 tab.

  4. Possible connection between two Alaskan catastrophes occurring 25 yr apart (1964 and 1989)

    NASA Astrophysics Data System (ADS)

    Kvenvolden, Keith A.; Carlson, Paul R.; Threlkeld, Charles N.; Warden, Augusta

    1993-09-01

    On March 24, 1989, the Exxon Valdez supertanker grounded on Bligh Reef, spilling North Slope crude oil into Prince William Sound, Alaska. Tracking the geochemical fate of this spilled oil has revealed, in addition to weathered products from the spill, minor oil residues on beaches from a distinctly different source. By using carbon isotopic compositions of whole-oil residues as a principal method of identification, we found that the δ13C values of Exxon Valdez oil (one sample) and its residues (eight samples from six islands) average -29.3 ±0.1‰. In contrast, the non-Exxon Valdez residues (15 samples from 12 localities) have an average δ13C value of -23.8 ±0.1‰. This tight distribution of carbon isotopic values suggests a single event to explain the non-Exxon Valdez residues. This event likely was the Great Alaska Earthquake of March 27, 1964. This quake and the subsequent tsunami destroyed asphalt storage facilities at the old Valdez town site, spilling asphalt (δ13C = -23.6‰) into Port Valdez fjord. From there the asphalt apparently advanced south into the sound. Thus, the possible connection between two Alaskan catastrophes, separated by 25 yr, is found in the minor oil- like residues that continue to mark the two events on the beaches of Prince William Sound.

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

    PubMed Central

    Rempel, Julia D.; Uhanova, Julia

    2012-01-01

    Liver diseases, such as hepatitis C virus (HCV), are “broken spirit” diseases. The prevalence of HCV infection for American Indian/Alaskan Native (AI/AN) in the United States and Canadian Aboriginals varies; nonetheless, incidence rates of newly diagnosed HCV infection are typically higher relative to non-indigenous people. For AI/AN and Aboriginal peoples risk factors for the diagnosis of HCV can reflect that of the general population: predominately male, a history of injection drug use, in midlife years, with a connection with urban centers. However, the face of the indigenous HCV infected individual is becoming increasingly female and younger compared to non-indigenous counterparts. Epidemiology studies indicate that more effective clearance of acute HCV infection can occur for select Aboriginal populations, a phenomenon which may be linked to unique immune characteristics. For individuals progressing to chronic HCV infection treatment outcomes are comparable to other racial cohorts. Disease progression, however, is propelled by elevated rates of co-morbidities including type 2 diabetes and alcohol use, along with human immunodeficiency virus (HIV) co-infection relative to non-indigenous patients. Historical and personal trauma has a major role in the participation of high risk behaviors and associated diseases. Although emerging treatments provide hope, combating HCV related morbidity and mortality will require interventions that address the etiology of broken spirit diseases. PMID:23342378

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

    USGS Publications Warehouse

    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.

  7. Depth and temperature of permafrost on the Alaskan Arctic Slope; preliminary results

    USGS Publications Warehouse

    Lachenbruch, Arthur H.; Sass, J.H.; Lawver, L.A.; Brewer, M.C.; Moses, T.H.

    1982-01-01

    As permafrost is defined by its temperature, the only way to determine its depth is to monitor the return to equilibrium of temperatures in boreholes that penetrate permafrost. Such measurements are under way in 25 wells on the Alaskan Arctic Slope; 21 are in Naval Petroleum Reserve Alaska (NPRA), and 4 are in the foothills to the east. Near-equilibrium results indicate that permafrost thickness in NPRA generally ranges between 200 and 400 m (compared to 600+ m at Prudhoe Bay); there are large local variations and no conspicuous regional trends. By contrast the long-term mean temperature of the ground surface (one factor determining permafrost depth) varies systematically from north to south in a pattern modified by the regional topography. The observed variation in permafrost temperature and depth cannot result primarily from effects of surface bodies of water or regional variations in heat flow; they are consistent, however, with expectable variations in the thermal conductivity of the sediments. It remains to be determined (with conductivity measurements) whether certain sites with anomalously high local gradients have anomalously high heat flow; if they do, they might indicate upwelling of interstitial fluids in the underlying basin sediments.

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

    PubMed

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

    2013-05-01

    A retrospective chemical and biological study was carried out in Camden Bay, Alaskan Beaufort Sea, where single exploratory oil wells were drilled at two sites more than two decades ago. Barium from discharged drilling mud was present in sediments at concentrations as high as 14%, ~200 times above background, with significantly higher concentrations of Ba, but not other metals, within 250 m of the drilling site versus reference stations. Elevated concentrations of Cr, Cu, Hg and Pb were found only at two stations within 25 m of one drilling site. Concentrations of total polycyclic aromatic hydrocarbons (TPAH) were not significantly different at reference versus drilling-site stations; however, TPAH were elevated in Ba-rich layers from naturally occurring perylene in ancient formation cuttings. Infaunal biomass and species abundance were not significantly different at reference versus drilling-site stations; infauna were less diverse at drilling-site stations. Our assessment showed that discharges from single wells within large areas caused minimal long-term, adverse impacts to the benthic ecosystem. PMID:23535013

  9. Upwelling on the continental slope of the Alaskan Beaufort Sea: Storms, ice, and oceanographic response

    NASA Astrophysics Data System (ADS)

    Pickart, Robert S.; Moore, G. W. K.; Torres, Daniel J.; Fratantoni, Paula S.; Goldsmith, Roger A.; Yang, Jiayan

    2009-01-01

    The characteristics of Pacific-born storms that cause upwelling along the Beaufort Sea continental slope, the oceanographic response, and the modulation of the response due to sea ice are investigated. In fall 2002 a mooring array located near 152°W measured 11 significant upwelling events that brought warm and salty Atlantic water to shallow depths. When comparing the storms that caused these events to other Aleutian lows that did not induce upwelling, interesting trends emerged. Upwelling occurred most frequently when storms were located in a region near the eastern end of the Aleutian Island Arc and Alaskan Peninsula. Not only were these storms deep but they generally had northward-tending trajectories. While the steering flow aloft aided this northward progression, the occurrence of lee cyclogenesis due to the orography of Alaska seems to play a role as well in expanding the meridional influence of the storms. In late fall and early winter both the intensity and frequency of the upwelling diminished significantly at the array site. It is argued that the reduction in amplitude was due to the onset of heavy pack ice, while the decreased frequency was due to two different upper-level atmospheric blocking patterns inhibiting the far field influence of the storms.

  10. Estimation of carbon emissions from wildfires in Alaskan boreal forests using AVHRR data

    SciTech Connect

    Kasischke, E.S.; French, N.H.F.; Bourgeau-Chavez, L.L )

    1993-06-01

    The objectives of this research study were to evaluate the utility of using AVHRR data for locating and measuring the areal extent of wildfires in the boreal forests of Alaska and to estimate the amount of carbon being released during these fires. Techniques were developed to using the normalized difference vegetation signature derived from AVHRR data to detect and measure the area of fires in Alaska. A model was developed to estimate the amount of biomass/carbon being stored in Alaskan boreal forests, and the amount of carbon released during fires. The AVHRR analysis resulted in detection of > 83% of all forest fires greater than 2,000 ha in size in the years 1990 and 1991. The areal estimate derived from AVHRR data were 75% of the area mapped by the Alaska Fire Service for these years. Using fire areas and locations for 1954 through 1992, it was determined that on average, 13.0 gm-C-m-2 of boreal forest area is released during fires every year. This estimate is two to six times greater than previous reported estimates. Our conclusions are that the analysis of AVHRR data represents a viable means for detecting and mapping fires in boreal regions on a global basis.

  11. Cost-Optimal Pathways to 75% Fuel Reduction in Remote Alaskan Villages

    SciTech Connect

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

    2015-08-01

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

    SciTech Connect

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

    1995-12-31

    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.

  13. Incorporating deep and shallow components of genetic structure into the management of Alaskan red king crab.

    PubMed

    Grant, William Stewart; Cheng, Wei

    2012-12-01

    Observed patterns of genetic variability among marine populations are shaped not only by contemporary levels of gene flow, but also by divergences during historical isolations. We examined variability at 15 SNP loci and in mtDNA sequences (COI, 665 bp) in red king crab from 17 localities in the North Pacific. These markers define three geographically distinct evolutionary lineages (SNPs, F(CT) = 0.054; mtDNA Φ(CT) = 0.222): (i) Okhotsk Sea-Norton Sound-Aleutian Islands, (ii) southeastern Bering Sea-western Gulf of Alaska, and (iii) Southeast Alaska. Populations in the Bering Sea and in Southeast Alaska are genetically heterogeneous, but populations in the center of the range are homogeneous. Mitochondrial DNA diversity drops from h = 0.91 in the northwestern Pacific to h = 0.24 in the Southeast Alaska. Bayesian skyline plots (BSPs) indicate postglacial population expansions, presumably from ice-age refugia. BSPs of sequences simulated under a demographic model defined by late Pleistocene temperatures failed to detect demographic variability before the last glacial maximum. These results sound a note of caution for the interpretation of BSPs. Population fragmentation in the Bering Sea and in Southeast Alaskan waters requires population management on a small geographic scale, and deep evolutionary partitions between the three geographic groups mandate regional conservation measures. PMID:23346227

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

    USGS Publications Warehouse

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

    2010-01-01

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

  15. Temperature and plant species control over litter decomposition in Alaskan tundra

    SciTech Connect

    Hobbie, S.E.

    1996-11-01

    This study compared effects of increased temperature and litter from different Alaskan tundra plant species on cycling of carbon and nitrogen through litter and soil in microcosms. Warming between 4{degrees} and 10{degrees}C significantly increased rates of soil and litter respiration, litter decomposition, litter nitrogen release, and soil net nitrogen mineralization. Thus, future warming will directly increase rates of carbon and nitrogen cycling through litter and soil in tundra. In addition, differences among species` litter in rates of decomposition, N release, and effects on soil net nitrogen mineralization were sometimes larger than differences between the two temperature treatments within a species. Thus, changes in plant community structure and composition associated with future warming will have important consequences for how elements cycle through litter and soil in tundra. In general, species within a growth form (graminoids, evergreen shrubs, deciduous shrubs, and mosses) were more similar in their effects on decomposition than were species belonging to different growth forms, with gramminoid litter having the fastest rate and litter of deciduous shrubs and mosses having the slowest rates. Differences in rates of litter decomposition were more related to carbon quality than to nitrogen concentration. Increased abundance of deciduous shrubs with future climate warming will promote carbon storage, because of their relatively large allocation to woody stems that decompose slowly. Changes in moss abundance will also have important consequences for future carbon and nitrogen cycling, since moss litter is extremely recalcitrant and has a low potential to immobilize nitrogen. 82 refs., 8 figs., 7 tabs.

  16. Alaskan Wild Berry Resources and Human Health Under the Cloud of Climate Change

    PubMed Central

    KELLOGG, JOSHUA; WANG, JINZHI; FLINT, COURTNEY; RIBNICKY, DAVID; KUHN, PETER; DE MEJIA, ELVIRA GONZÁLEZ; RASKIN, ILYA; LILA, MARY ANN

    2009-01-01

    Wild berries are integral dietary components for Alaska Native tribes and a rich source of polyphenolic metabolites that can ameliorate metabolic disorders such as obesity and diabetes. In this study, five species of wild Alaskan berries (Vaccinium ovalifolium, V. uliginosum, Rubus chamaemorus, R. spectabilis, and Empetrum nigrum) were screened for bioactivity through a community-participatory research method involving three geographically-distinct tribal communities. Compositional analysis by HPLC and LC-MS2 revealed substantial site-specific variation in anthocyanins (0.01-4.39 mg/g-FW) and proanthocyanidins (0.74-6.25 mg/g-FW), and identified A-type proanthocyanidin polymers. R. spectabilis increased expression levels of preadipocyte-factor-1 (182%), and proanthocyanidin-enriched fractions from other species reduced lipid accumulation in 3T3-L1 adipocytes. Selected extracts reduced serum glucose levels in C57bl/6j mice by up to 45%. Local observations provided robust insights into effects of climatic fluctuations on berry abundance and quality, and preliminary site-specific compositional and bioactivity differences were noted, suggesting the need to monitor this Alaska Native resource as climate shifts impact the region. PMID:20025229

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

    PubMed Central

    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

  18. Incorporating deep and shallow components of genetic structure into the management of Alaskan red king crab

    PubMed Central

    Grant, William Stewart; Cheng, Wei

    2012-01-01

    Observed patterns of genetic variability among marine populations are shaped not only by contemporary levels of gene flow, but also by divergences during historical isolations. We examined variability at 15 SNP loci and in mtDNA sequences (COI, 665 bp) in red king crab from 17 localities in the North Pacific. These markers define three geographically distinct evolutionary lineages (SNPs, FCT = 0.054; mtDNA ΦCT = 0.222): (i) Okhotsk Sea–Norton Sound–Aleutian Islands, (ii) southeastern Bering Sea–western Gulf of Alaska, and (iii) Southeast Alaska. Populations in the Bering Sea and in Southeast Alaska are genetically heterogeneous, but populations in the center of the range are homogeneous. Mitochondrial DNA diversity drops from h = 0.91 in the northwestern Pacific to h = 0.24 in the Southeast Alaska. Bayesian skyline plots (BSPs) indicate postglacial population expansions, presumably from ice-age refugia. BSPs of sequences simulated under a demographic model defined by late Pleistocene temperatures failed to detect demographic variability before the last glacial maximum. These results sound a note of caution for the interpretation of BSPs. Population fragmentation in the Bering Sea and in Southeast Alaskan waters requires population management on a small geographic scale, and deep evolutionary partitions between the three geographic groups mandate regional conservation measures. PMID:23346227

  19. Comprehensive assessment of coastal eutrophication in Taiwan and its implications for management strategy.

    PubMed

    Liu, Ta-Kang; Chen, Ping; Chen, Hou-Yu

    2015-08-15

    Due to the rapid population growth, anthropogenic activities result in agricultural, industrial, and urban diffuse runoffs that elevate the level of nutrients such as nitrogen and phosphorus in coastal waters. Currently there is no integrated analysis for coastal eutrophication in Taiwan. A comprehensive analysis of the coastal eutrophic status was performed in this study based on decade-long coastal water quality monitoring data from Taiwan's Environmental Protection Administration. A 3-tiered monitoring strategy is recommended based on the severity of the current eutrophication state. Results indicate that the most problematic area of coastal eutrophication is located in the estuary of the Donggang River (DGR) and its adjacent coastal waters, i.e., the Kao-Ping mouth (KPM) and Dapeng Bay (DPB) in south-western Taiwan. With a worsening eutrophic status, these areas demand intensive monitoring and research with higher spatial and temporal resolutions to evaluate the stresses of nutrient forcing and predict possible future responses. PMID:26070956

  20. Coastal foredune evolution: evidence for physical control

    NASA Astrophysics Data System (ADS)

    Ruggiero, P.; Zarnetske, P. L.; Mull, J.; Hacker, S.; Seabloom, E.

    2010-12-01

    Coastal dunes in the US Pacific Northwest, comprising approximately 45% of the Oregon and Washington coasts, were historically managed to maximize coastal protection through the planting of two invasive beach grass species, European beach grass (Ammophila arenaria), and American beach grass (Ammophila breviligulata). The switch in dominance from native, Elymus mollis, to invasive dune species resulted in a complete state change in coastal dune systems. Prior to the invasion of the exotic species, native dune plants formed small hillocks or short parallel ridges depending on sand supply. In contrast, the invasive beach grasses create stable foredunes, with dune ridges reaching as much as 15 to 20 meters tall which intercept sand and decrease sand supply to the back dune. Currently pressure exists to manage some of these biogeomorphic systems for ecosystem restoration rather than solely for coastal protection. To balance these competing management objectives it has become crucial to quantify the relative importance of physical versus ecological controls on coastal dune evolution over various time and space scales. In this paper we examine the remarkable evolution of the foredunes within the Columbia River Littoral Cell (CRLC) from 1988 to 2010, a time period in which quantitative topographic surveys are bracketed by quantitative ecological surveys of grass cover dominance. Most of the region’s foredunes were severely eroded during the two extraordinary winters of 1997/1998 (a major El Niño event) and 1998/1999 (a moderate La Nina event). Subsequent to these winters the beaches and foredunes have, for the most part, experienced significant seaward progradation and vertical accretion. Across the mouth of the Columbia River significant gradients exist in both the ecological (grass species dominance and density) and physical (shoreline change rates) parameters that are thought to be first order controls on coastal dune geomorphology. These gradients allow us to test