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Sample records for alaska north slope

  1. North Slope, Alaska ESI: NESTS (Nest Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for waterfowl, seabirds, gulls and terns for the North Slope of Alaska. Vector points in this data set...

  2. North Slope, Alaska ESI: FISH (Fish Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, estuarine, anadromous, and freshwater fish species for the North Slope of Alaska. Vector...

  3. North Slope, Alaska ESI: FACILITY (Facility Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains data for oil field facilities for the North Slope of Alaska. Vector points in this data set represent oil field facility locations. This data...

  4. North Slope, Alaska ESI: M_MAMMAL (Marine Mammal Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for whales, seals, walruses, and polar bears for the North Slope of Alaska. Vector polygons in this data...

  5. North Slope, Alaska ESI: T_MAMMAL (Terrestrial Mammal Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for brown bears, caribou, and muskoxen for the North Slope, Alaska. Vector polygons in this data set...

  6. Alaska North Slope regional gas hydrate production modeling forecasts

    Science.gov (United States)

    Wilson, S.J.; Hunter, R.B.; Collett, T.S.; Hancock, S.; Boswell, R.; Anderson, B.J.

    2011-01-01

    A series of gas hydrate development scenarios were created to assess the range of outcomes predicted for the possible development of the "Eileen" gas hydrate accumulation, North Slope, Alaska. Production forecasts for the "reference case" were built using the 2002 Mallik production tests, mechanistic simulation, and geologic studies conducted by the US Geological Survey. Three additional scenarios were considered: A "downside-scenario" which fails to identify viable production, an "upside-scenario" describes results that are better than expected. To capture the full range of possible outcomes and balance the downside case, an "extreme upside scenario" assumes each well is exceptionally productive.Starting with a representative type-well simulation forecasts, field development timing is applied and the sum of individual well forecasts creating the field-wide production forecast. This technique is commonly used to schedule large-scale resource plays where drilling schedules are complex and production forecasts must account for many changing parameters. The complementary forecasts of rig count, capital investment, and cash flow can be used in a pre-appraisal assessment of potential commercial viability.Since no significant gas sales are currently possible on the North Slope of Alaska, typical parameters were used to create downside, reference, and upside case forecasts that predict from 0 to 71??BM3 (2.5??tcf) of gas may be produced in 20 years and nearly 283??BM3 (10??tcf) ultimate recovery after 100 years.Outlining a range of possible outcomes enables decision makers to visualize the pace and milestones that will be required to evaluate gas hydrate resource development in the Eileen accumulation. Critical values of peak production rate, time to meaningful production volumes, and investments required to rule out a downside case are provided. Upside cases identify potential if both depressurization and thermal stimulation yield positive results. An "extreme upside

  7. Site Scientist for the North Slope of Alaska Site

    Energy Technology Data Exchange (ETDEWEB)

    Verlinde, Johannes [Pennsylvania State Univ., State College, PA (United States)

    2016-03-11

    Under this grant our team contributed scientific support to the Department of Energy Atmospheric Radiation Program’s (DOE-ARM) Infrastructure team to maintain high quality research data at the DOE-ARM North Slope of Alaska with special emphasis on the radars. Under our guidance two major field campaigns focusing on mixed-phase Arctic clouds were conducted that greatly increased the community’s understanding of the many processes working together to control the evolution of single-layer cloud mixed-phase clouds. A series of modeling and observational studies revealed that the longevity of the radiatively important liquid phase is strongly dependent on how the ice phase develops in mixed-phase clouds. A new ice microphysics parameterization was developed to capture better the natural evolution of ice particle growth in evolving environments. An ice particle scattering database was developed for all ARM radar frequencies. This database was used in a radar simulator (Doppler spectrum and polarimetric variables) to aid in the interpretation of the advanced ARM radars. At the conclusion of this project our team was poised to develop a complete radar simulator consistent with the new microphysical parameterization, taking advantage of parameterization’s advanced characterization of the ice shape and ice density.

  8. Geology and estimated recoverable gas reserves of the north slope (onshore) of Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The purpose of this report is to demonstrate that, based on known geologic conditions, estimated remaining recoverable gas reserves of the Alaska North Slope...

  9. North Slope, Alaska ESI: ESI (Environmental Sensitivity Index Shoreline Types - Lines and Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector lines and polygons representing the shoreline and coastal habitats for the North Slope of Alaska classified according to the...

  10. Economics of Alaska North Slope gas utilization options

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, C.P.; Doughty, T.C.; Hackworth, J.H.; North, W.B.; Robertson, E.P.

    1996-08-01

    The recoverable natural gas available for sale in the developed and known undeveloped fields on the Alaskan North Slope (ANS) total about 26 trillion cubic feet (TCF), including 22 TCF in the Prudhoe Bay Unit (PBU) and 3 TCF in the undeveloped Point Thomson Unit (PTU). No significant commercial use has been made of this large natural gas resource because there are no facilities in place to transport this gas to current markets. To date the economics have not been favorable to support development of a gas transportation system. However, with the declining trend in ANS oil production, interest in development of this huge gas resource is rising, making it important for the U.S. Department of Energy, industry, and the State of Alaska to evaluate and assess the options for development of this vast gas resource. The purpose of this study was to assess whether gas-to-liquids (GTL) conversion technology would be an economic alternative for the development and sale of the large, remote, and currently unmarketable ANS natural gas resource, and to compare the long term economic impact of a GTL conversion option to that of the more frequently discussed natural gas pipeline/liquefied natural gas (LNG) option. The major components of the study are: an assessment of the ANS oil and gas resources; an analysis of conversion and transportation options; a review of natural gas, LNG, and selected oil product markets; and an economic analysis of the LNG and GTL gas sales options based on publicly available input needed for assumptions of the economic variables. Uncertainties in assumptions are evaluated by determining the sensitivity of project economics to changes in baseline economic variables.

  11. Alaska North Slope Tundra Travel Model and Validation Study

    Energy Technology Data Exchange (ETDEWEB)

    Harry R. Bader; Jacynthe Guimond

    2006-03-01

    The Alaska Department of Natural Resources (DNR), Division of Mining, Land, and Water manages cross-country travel, typically associated with hydrocarbon exploration and development, on Alaska's arctic North Slope. This project is intended to provide natural resource managers with objective, quantitative data to assist decision making regarding opening of the tundra to cross-country travel. DNR designed standardized, controlled field trials, with baseline data, to investigate the relationships present between winter exploration vehicle treatments and the independent variables of ground hardness, snow depth, and snow slab thickness, as they relate to the dependent variables of active layer depth, soil moisture, and photosynthetically active radiation (a proxy for plant disturbance). Changes in the dependent variables were used as indicators of tundra disturbance. Two main tundra community types were studied: Coastal Plain (wet graminoid/moist sedge shrub) and Foothills (tussock). DNR constructed four models to address physical soil properties: two models for each main community type, one predicting change in depth of active layer and a second predicting change in soil moisture. DNR also investigated the limited potential management utility in using soil temperature, the amount of photosynthetically active radiation (PAR) absorbed by plants, and changes in microphotography as tools for the identification of disturbance in the field. DNR operated under the assumption that changes in the abiotic factors of active layer depth and soil moisture drive alteration in tundra vegetation structure and composition. Statistically significant differences in depth of active layer, soil moisture at a 15 cm depth, soil temperature at a 15 cm depth, and the absorption of photosynthetically active radiation were found among treatment cells and among treatment types. The models were unable to thoroughly investigate the interacting role between snow depth and disturbance due to a

  12. Commercial possibilities for stranded conventional gas from Alaska's North Slope

    Science.gov (United States)

    Attanasi, E.D.; Freeman, P.A.

    2014-01-01

    Stranded gas resources are defined for this study as gas resources in discrete accumulations that are not currently commercially producible, or producible at full potential, for either physical or economic reasons. Approximately 35 trillion cubic feet (TCF) of stranded gas was identified on Alaska’s North Slope. The commercialization of this resource requires facilities to transport gas to markets where sales revenue will be sufficient to offset the cost of constructing and operating a gas delivery system. With the advent of the shale gas revolution, plans for a gas pipeline to the conterminous US have been shelved (at least temporarily) and the State and resource owners are considering a liquefied natural gas (LNG) export project that targets Asian markets. This paper focuses on competitive conditions for Asian gas import markets by estimating delivered costs of competing supplies from central Asia, Russia, Indonesia, Malaysia, and Australia in the context of a range of import gas demand projections for the period from 2020 to 2040. These suppliers’ costs are based on the cost of developing, producing, and delivering to markets tranches of the nearly 600 TCF of recoverable gas from their own conventional stranded gas fields. The results of these analyses imply that Alaska’s gas exports to Asia will likely encounter substantial competitive challenges. The sustainability of Asia’s oil-indexed LNG pricing is also discussed in light of a potentially intense level of competition.

  13. Toxicity and water quality of natural waterbodies, reserve pits and selected sites at North Slope, Alaska, oilfields

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Oilfield activities on the North Slope of Alaska result in production of large amounts of wastes and fugitive dust. Surface storage and disposal of these wastes may...

  14. Economics of Undiscovered Oil and Gas in the North Slope of Alaska: Economic Update and Synthesis

    Science.gov (United States)

    Attanasi, E.D.; Freeman, P.A.

    2009-01-01

    The U.S. Geological Survey (USGS) has published assessments by geologists of undiscovered conventional oil and gas accumulations in the North Slope of Alaska; these assessments contain a set of scientifically based estimates of undiscovered, technically recoverable quantities of oil and gas in discrete oil and gas accumulations that can be produced with conventional recovery technology. The assessments do not incorporate economic factors such as recovery costs and product prices. The assessors considered undiscovered conventional oil and gas resources in four areas of the North Slope: (1) the central North Slope, (2) the National Petroleum Reserve in Alaska (NPRA), (3) the 1002 Area of the Arctic National Wildlife Refuge (ANWR), and (4) the area west of the NPRA, called in this report the 'western North Slope'. These analyses were prepared at different times with various minimum assessed oil and gas accumulation sizes and with slightly different assumptions. Results of these past studies were recently supplemented with information by the assessment geologists that allowed adjustments for uniform minimum assessed accumulation sizes and a consistent set of assumptions. The effort permitted the statistical aggregation of the assessments of the four areas composing the study area. This economic analysis is based on undiscovered assessed accumulation distributions represented by the four-area aggregation and incorporates updates of costs and technological and fiscal assumptions used in the initial economic analysis that accompanied the geologic assessment of each study area.

  15. North Slope, Alaska ESI: HYDRO (Hydrography Lines and Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector lines and polygons representing coastal hydrography used in the creation of the Environmental Sensitivity Index (ESI) for the North...

  16. 76 FR 56789 - Call for Nominations: North Slope Science Initiative, Science Technical Advisory Panel, Alaska

    Science.gov (United States)

    2011-09-14

    ... biology, biometrics, sociology, cultural anthropology, economics, ornithology, oceanography, fisheries... minimum of 5 years of work experience in Alaska in their field of expertise, preferably in the North...

  17. The North Slope of Alaska and Tourism: Potential Impacts on the Arctic National Wildlife Refuge (ANWR)

    Science.gov (United States)

    Everett, L. R.

    2004-12-01

    The hydrocarbon industry of Alaska is currently the leading producer of revenue for the Alaskan state economy. Second only to hydrocarbons is the tourism industry. Tourism has been a viable industry since the 1890's when cruises touted the beauty of glaciers and icebergs along the Alaskan coastline. This industry has seen a steady growth for the past few decades throughout the state. The North Slope of Alaska, particularly Prudhoe Bay and the National Petroleum Reserve, has long been associated with hydrocarbon development and today displays a landscape dotted with gravel drill pads, gas and oil pipelines and housing for the oil workers. While tourism is not usually considered hand in hand with the hydrocarbon industry, it has mimicked the development of hydrocarbons almost since the beginning. Today one not only sees the effects of the oil industry on the North Slope, but also the tourist industry as planes unload dozens of tourists, or tour buses and private vehicles arrive daily via the Dalton Highway. In Deadhorse, hotels that once only housed the oil workers now welcome the tourist, offering tours of the oil fields and adjacent areas and have become jumping off sites for wilderness trips. Tourism will create jobs as well as revenue. However, at present, there are few restrictions or guidelines in place that will deal with the potential impacts of increased tourism. Because of this there are many concerns about the possible impacts tourism and the infrastructure development will have on the North Slope. To list several concerns: (1) What are the impacts of increased tourism and the infrastructure development? (2) What will the impacts be on the Arctic National Wildlife Refuge (ANWR), which sits a mere 60 miles to the east of Deadhorse? (3) Will hydrocarbon development in ANWR and the associated infrastructure exacerbate potential impact by encouraging greater use of the Refuge by tourists? (4) Will tourism itself have a negative impact on this fragile

  18. Physical and Chemical Implications of Mid-Winter Pumping of Trunda Lakes - North Slope, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Hinzman, Larry D. (University of Alaska Fairbanks, Water and Environmental Research Center); Lilly, Michael R. (Geo-Watersheds Scientific); Kane, Douglas L. (University of Alaska Fairbanks, Water and Environmental Research Center); Miller, D. Dan (University of Alaska Fairbanks, Water and Environmental Research Center); Galloway, Braden K. (University of Alaska Fairbanks, Water and Environmental Research Center); Hilton, Kristie M. (Geo-Watersheds Scientific); White, Daniel M. (University of Alaska Fairbanks, Water and Environmental Research Center)

    2005-09-30

    Tundra lakes on the North Slope, Alaska, are an important resource for energy development and petroleum field operations. A majority of exploration activities, pipeline maintenance, and restoration activities take place on winter ice roads that depend on water availability at key times of the winter operating season. These same lakes provide important fisheries and ecosystem functions. In particular, overwintering habitat for fish is one important management concern. This study focused on the evaluation of winter water use in the current field operating areas to provide a better understanding of the current water use practices. It found that under the current water use practices, there were no measurable negative effects of winter pumping on the lakes studied and current water use management practices were appropriately conservative. The study did find many areas where improvements in the understanding of tundra lake hydrology and water usage would benefit industry, management agencies, and the protection of fisheries and ecosystems.

  19. Biodegradation of Alaska North Slope crude oil enhanced by commercial bioremediation agents

    Energy Technology Data Exchange (ETDEWEB)

    Aldrett, S.; Bonner, J.S.; Mills, M.A.; McDonald, T.J.; Autenrieth, R.L. [Texas A and M Univ., College Station, TX (United States). Dept. of Civil Engineering

    1996-09-01

    The biodegradation of crude oil was studied. Tests were conducted in which natural unpolluted seawater was collected and then contaminated with Alaska North Slope crude oil. The oil was weathered by heating it to 521 degrees F to remove the light-end hydrocarbons. A total of 13 different bioremediation agents were tested, each one separately. Three samples per treatment were destructively analysed for petroleum chemistry. The thirteen treatments were analyzed for oil and grease. It was found that microbial degradation of petroleum hydrocarbons was enhanced by the addition of bioremediation agents, but it was not possible to identify the intermediate products responsible for the increase of resolved petroleum hydrocarbons through time. It was suggested that caution be used when interpreting results since the protocols used to test the products were prone to uncontrollable variations. 11 refs., 5 tabs., 6 figs.

  20. Pre- and post-drill comparison of the Mount Elbert gas hydrate prospect, Alaska North Slope

    Science.gov (United States)

    Lee, M.W.; Agena, W.F.; Collett, T.S.; Inks, T.L.

    2011-01-01

    In 2006, the United States Geological Survey (USGS) completed a detailed analysis and interpretation of available 2-D and 3-D seismic data, along with seismic modeling and correlation with specially processed downhole well log data for identifying potential gas hydrate accumulations on the North Slope of Alaska. A methodology was developed for identifying sub-permafrost gas hydrate prospects within the gas hydrate stability zone in the Milne Point area. The study revealed a total of 14 gas hydrate prospects in this area.In order to validate the gas hydrate prospecting protocol of the USGS and to acquire critical reservoir data needed to develop a longer-term production testing program, a stratigraphic test well was drilled at the Mount Elbert prospect in the Milne Point area in early 2007. The drilling confirmed the presence of two prominent gas-hydrate-bearing units in the Mount Elbert prospect, and high quality well logs and core data were acquired. The post-drill results indicate pre-drill predictions of the reservoir thickness and the gas-hydrate saturations based on seismic and existing well data were 90% accurate for the upper unit (hydrate unit D) and 70% accurate for the lower unit (hydrate unit C), confirming the validity of the USGS approach to gas hydrate prospecting. The Mount Elbert prospect is the first gas hydrate accumulation on the North Slope of Alaska identified primarily on the basis of seismic attribute analysis and specially processed downhole log data. Post-drill well log data enabled a better constraint of the elastic model and the development of an improved approach to the gas hydrate prospecting using seismic attributes. ?? 2009.

  1. Alaska North Slope National Energy Strategy initiative: Analysis of five undeveloped fields

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, C.P.; Allaire, R.B.; Doughty, T.C.; Faulder, D.D.; Irving, J.S.; Jamison, H.C.; White, G.J.

    1993-05-01

    The US Department of Energy was directed in the National Energy Strategy to establish a federal interagency task force to identify specific technical and regulatory barriers to the development of five undeveloped North Slope Alaska fields and make recommendations for their resolution. The five fields are West Sak, Point Thomson, Gwydyr Bay, Seal Island/Northstar, and Sandpiper Island. Analysis of environmental, regulatory, technical, and economic information, and data relating to the development potential of the five fields leads to the following conclusions: Development of the five fields would result in an estimated total of 1,055 million barrels of oil and 4.4 trillion cubic feet of natural gas and total investment of $9.4 billion in 1992 dollars. It appears that all five of the fields will remain economically marginal developments unless there is significant improvement in world oil prices. Costs of regulatory compliance and mitigation, and costs to reduce or maintain environmental impacts at acceptable levels influence project investments and operating costs and must be considered in the development decision making process. The development of three of the fields (West Sak, Point Thomson, and Gwydyr Bay) that are marginally feasible would have an impact on North Slope production over the period from about 2000 to 2014 but cannot replace the decline in Prudhoe Bay Unit production or maintain the operation of the Trans-Alaska Pipeline System (TAPS) beyond about 2014 with the assumption that the TAPS will shut down when production declines to the range of 400 to 200 thousand barrels of oil/day. Recoverable reserves left in the ground in the currently producing fields and soon to be developed fields, Niakuk and Point McIntyre, would range from 1 billion to 500 million barrels of oil corresponding to the time period of 2008 to 2014 based on the TAPS shutdown assumption.

  2. IPY to Mark Expansion of Research Facilities on the North Slope of Alaska

    Science.gov (United States)

    Zak, B. D.; Eicken, H.; Sheehan, G. W.; Glenn, R.

    2004-12-01

    The Barrow Global Climate Change Research Facility will open to researchers on the North Slope of Alaska during the 2007-08 anniversary of the first IPY. Between 1949 and 1980, arctic researchers were very active on the North Slope and in nearby waters largely because of the Naval Arctic Research Laboratory (NARL) at Barrow. NARL provided easy access, laboratories and logistical support. NARL was closed in 1981, but particularly during this past decade, Barrow-based arctic research projects have been back on the upswing. The National Oceanic and Atmospheric Administration (NOAA) Climate Monitoring and Diagnostics Laboratory (CMDL) Barrow station was founded during the 1970s, and continues as part of NOAA's five station global network for monitoring atmospheric composition. The North Slope Borough's Department of Wildlife Management (DWM) has for the past 20 years conducted its own research. The DWM also served as logistical provider for growing numbers of arctic researchers without other logistical support. In the late 1990s, the Department of Energy Atmospheric Radiation Measurement program (ARM: DOE's principal climate change research effort) created a Cloud and Radiation Testbed on the North Slope with atmospheric instrumentation at Barrow and Atqasuk. It is now part of the ARM Climate Research Facility, a National User Facility. In response to growing researcher needs, the Barrow Arctic Science Consortium (BASC) was formed in the late 1990s as a non-profit logistical support and community coordinating organization, and received the endorsement of Ukpeagvik Inupiat Corporation (UIC), NSB and the local community college. BASC provides logistical support to National Science Foundation (NSF) researchers through a cooperative agreement, and to others on a fee for service basis. UIC also dedicated 11 square miles of its land as the Barrow Environmental Observatory (BEO), and charged BASC with management of the BEO. This land that has been used for research for more

  3. Evaluation of Gas Production Potential of Hydrate Deposits in Alaska North Slope using Reservoir Simulations

    Science.gov (United States)

    Nandanwar, M.; Anderson, B. J.

    2015-12-01

    Over the past few decades, the recognition of the importance of gas hydrates as a potential energy resource has led to more and more exploration of gas hydrate as unconventional source of energy. In 2002, U.S. Geological Survey (USGS) started an assessment to conduct a geology-based analysis of the occurrences of gas hydrates within northern Alaska. As a result of this assessment, many potential gas hydrate prospects were identified in the eastern National Petroleum Reserve Alaska (NPRA) region of Alaska North Slope (ANS) with total gas in-place of about 2 trillion cubic feet. In absence of any field test, reservoir simulation is a powerful tool to predict the behavior of the hydrate reservoir and the amount of gas that can be technically recovered using best suitable gas recovery technique. This work focuses on the advanced evaluation of the gas production potential of hydrate accumulation in Sunlight Peak - one of the promising hydrate fields in eastern NPRA region using reservoir simulations approach, as a part of the USGS gas hydrate development Life Cycle Assessment program. The main objective of this work is to develop a field scale reservoir model that fully describes the production design and the response of hydrate field. Due to the insufficient data available for this field, the distribution of the reservoir properties (such as porosity, permeability and hydrate saturation) are approximated by correlating the data from Mount Elbert hydrate field to obtain a fully heterogeneous 3D reservoir model. CMG STARS is used as a simulation tool to model multiphase, multicomponent fluid flow and heat transfer in which an equilibrium model of hydrate dissociation was used. Production of the gas from the reservoir is carried out for a period of 30 years using depressurization gas recovery technique. The results in terms of gas and water rate profiles are obtained and the response of the reservoir to pressure and temperature changes due to depressurization and hydrate

  4. ARM-ACME V: ARM Airborne Carbon Measurements V on the North Slope of Alaska Science and Implementation Plan

    Energy Technology Data Exchange (ETDEWEB)

    Biraud, S [Lawrence Berkeley National Laboratory

    2015-05-01

    Atmospheric temperatures are warming faster in the Arctic than predicted by climate models. The impact of this warming on permafrost degradation is not well understood, but it is projected to increase carbon decomposition and greenhouse gas production (CO₂ and/or CH₄) by arctic ecosystems. Airborne observations of atmospheric trace gases, aerosols, and cloud properties at the North Slope of Alaska are improving our understanding of global climate, with the goal of reducing the uncertainty in global and regional climate simulations and projections.

  5. Environmental Sensitivity Index (ESI) Atlas: Alaska - 2, Northwest Arctic - 2002, North Slope - 2005, Western - 2003, maps and geographic systems data (NODC Accession 0049913)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set comprises the Environmental Sensitivity Index (ESI) data for Northwest Arctic, North Slope, and Western Alaska. ESI data characterize estuarine...

  6. North Slope, Alaska: Source rock distribution, richness, thermal maturity, and petroleum charge

    Science.gov (United States)

    Peters, K.E.; Magoon, L.B.; Bird, K.J.; Valin, Z.C.; Keller, M.A.

    2006-01-01

    Four key marine petroleum source rock units were identified, characterized, and mapped in the subsurface to better understand the origin and distribution of petroleum on the North Slope of Alaska. These marine source rocks, from oldest to youngest, include four intervals: (1) Middle-Upper Triassic Shublik Formation, (2) basal condensed section in the Jurassic-Lower Cretaceous Kingak Shale, (3) Cretaceous pebble shale unit, and (4) Cretaceous Hue Shale. Well logs for more than 60 wells and total organic carbon (TOC) and Rock-Eval pyrolysis analyses for 1183 samples in 125 well penetrations of the source rocks were used to map the present-day thickness of each source rock and the quantity (TOC), quality (hydrogen index), and thermal maturity (Tmax) of the organic matter. Based on assumptions related to carbon mass balance and regional distributions of TOC, the present-day source rock quantity and quality maps were used to determine the extent of fractional conversion of the kerogen to petroleum and to map the original TOC (TOCo) and the original hydrogen index (HIo) prior to thermal maturation. The quantity and quality of oil-prone organic matter in Shublik Formation source rock generally exceeded that of the other units prior to thermal maturation (commonly TOCo > 4 wt.% and HIo > 600 mg hydrocarbon/g TOC), although all are likely sources for at least some petroleum on the North Slope. We used Rock-Eval and hydrous pyrolysis methods to calculate expulsion factors and petroleum charge for each of the four source rocks in the study area. Without attempting to identify the correct methods, we conclude that calculations based on Rock-Eval pyrolysis overestimate expulsion factors and petroleum charge because low pressure and rapid removal of thermally cracked products by the carrier gas retards cross-linking and pyrobitumen formation that is otherwise favored by natural burial maturation. Expulsion factors and petroleum charge based on hydrous pyrolysis may also be high

  7. Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope: Coring operations, core sedimentology, and lithostratigraphy

    Science.gov (United States)

    Rose, K.; Boswell, R.; Collett, T.

    2011-01-01

    In February 2007, BP Exploration (Alaska), the U.S. Department of Energy, and the U.S. Geological Survey completed the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well (Mount Elbert well) in the Milne Point Unit on the Alaska North Slope. The program achieved its primary goals of validating the pre-drill estimates of gas hydrate occurrence and thickness based on 3-D seismic interpretations and wireline log correlations and collecting a comprehensive suite of logging, coring, and pressure testing data. The upper section of the Mount Elbert well was drilled through the base of ice-bearing permafrost to a casing point of 594??m (1950??ft), approximately 15??m (50??ft) above the top of the targeted reservoir interval. The lower portion of the well was continuously cored from 606??m (1987??ft) to 760??m (2494??ft) and drilled to a total depth of 914??m. Ice-bearing permafrost extends to a depth of roughly 536??m and the base of gas hydrate stability is interpreted to extend to a depth of 870??m. Coring through the targeted gas hydrate bearing reservoirs was completed using a wireline-retrievable system. The coring program achieved 85% recovery of 7.6??cm (3??in) diameter core through 154??m (504??ft) of the hole. An onsite team processed the cores, collecting and preserving approximately 250 sub-samples for analyses of pore water geochemistry, microbiology, gas chemistry, petrophysical analysis, and thermal and physical properties. Eleven samples were immediately transferred to either methane-charged pressure vessels or liquid nitrogen for future study of the preserved gas hydrate. Additional offsite sampling, analyses, and detailed description of the cores were also conducted. Based on this work, one lithostratigraphic unit with eight subunits was identified across the cored interval. Subunits II and Va comprise the majority of the reservoir facies and are dominantly very fine to fine, moderately sorted, quartz, feldspar, and lithic fragment-bearing to

  8. Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope: Overview of scientific and technical program

    Science.gov (United States)

    Hunter, R.B.; Collett, T.S.; Boswell, R.; Anderson, B.J.; Digert, S.A.; Pospisil, G.; Baker, R.; Weeks, M.

    2011-01-01

    The Mount Elbert Gas Hydrate Stratigraphic Test Well was drilled within the Alaska North Slope (ANS) Milne Point Unit (MPU) from February 3 to 19, 2007. The well was conducted as part of a Cooperative Research Agreement (CRA) project co-sponsored since 2001 by BP Exploration (Alaska), Inc. (BPXA) and the U.S. Department of Energy (DOE) in collaboration with the U.S. Geological Survey (USGS) to help determine whether ANS gas hydrate can become a technically and commercially viable gas resource. Early in the effort, regional reservoir characterization and reservoir simulation modeling studies indicated that up to 0.34 trillion cubic meters (tcm; 12 trillion cubic feet, tcf) gas may be technically recoverable from 0.92 tcm (33 tcf) gas-in-place within the Eileen gas hydrate accumulation near industry infrastructure within ANS MPU, Prudhoe Bay Unit (PBU), and Kuparuk River Unit (KRU) areas. To further constrain these estimates and to enable the selection of a test site for further data acquisition, the USGS reprocessed and interpreted MPU 3D seismic data provided by BPXA to delineate 14 prospects containing significant highly-saturated gas hydrate-bearing sand reservoirs. The "Mount Elbert" site was selected to drill a stratigraphic test well to acquire a full suite of wireline log, core, and formation pressure test data. Drilling results and data interpretation confirmed pre-drill predictions and thus increased confidence in both the prospect interpretation methods and in the wider ANS gas hydrate resource estimates. The interpreted data from the Mount Elbert well provide insight into and reduce uncertainty of key gas hydrate-bearing reservoir properties, enable further refinement and validation of the numerical simulation of the production potential of both MPU and broader ANS gas hydrate resources, and help determine viability of potential field sites for future extended term production testing. Drilling and data acquisition operations demonstrated that gas hydrate

  9. A comprehensive climatology of Arctic aerosol properties on the North Slope of Alaska

    Science.gov (United States)

    Creamean, Jessie; de Boer, Gijs; Shupe, Matthew; McComiskey, Allison

    2016-04-01

    Evaluating aerosol properties has implications for the formation of Arctic clouds, resulting in impacts on cloud lifetime, precipitation processes, and radiative forcing. There are many remaining uncertainties and large discrepancies regarding modeled and observed Arctic aerosol properties, illustrating the need for more detailed observations to improve simulations of Arctic aerosol and more generally, projections of the components of the aerosol-driven processes that impact sea ice loss/gain. In particular, the sources and climatic effects of Arctic aerosol particles are severely understudied. Here, we present a comprehensive, long-term record of aerosol observations from the North Slope of Alaska baseline site at Barrow. These measurements include sub- and supermicron (up to 10 μm) total mass and number concentrations, sub- and supermicron soluble inorganic and organic ion concentrations, submicron metal concentrations, submicron particle size distributions, and sub- and supermicron absorption and scattering properties. Aerosol extinction and number concentration measurements extend back to 1976, while the remaining measurements were implemented since. Corroboration between the chemical, physical, and optical property measurements is evident during periods of overlapping observations, demonstrating the reliability of the measurements. During the Arctic Haze in the winter/spring, high concentrations of long-range transported submicron sea salt, mineral dust, industrial metals, pollution (non-sea salt sulfate, nitrate, ammonium), and biomass burning species are observed concurrent with higher concentrations of particles with sizes that span the submicron range, enhanced absorption and scattering coefficients, and largest Ångström exponents. The summer is characterized by high concentrations of small biogenic aerosols (extinction coefficients. Fall is characterized by clean conditions, with supermicron sea salt representing the dominant aerosol type supporting

  10. De-convoluting mixed crude oil in Prudhoe Bay Field, North Slope, Alaska

    Science.gov (United States)

    Peters, K.E.; Scott, Ramos L.; Zumberge, J.E.; Valin, Z.C.; Bird, K.J.

    2008-01-01

    Seventy-four crude oil samples from the Barrow arch on the North Slope of Alaska were studied to assess the relative volumetric contributions from different source rocks to the giant Prudhoe Bay Field. We applied alternating least squares to concentration data (ALS-C) for 46 biomarkers in the range C19-C35 to de-convolute mixtures of oil generated from carbonate rich Triassic Shublik Formation and clay rich Jurassic Kingak Shale and Cretaceous Hue Shale-gamma ray zone (Hue-GRZ) source rocks. ALS-C results for 23 oil samples from the prolific Ivishak Formation reservoir of the Prudhoe Bay Field indicate approximately equal contributions from Shublik Formation and Hue-GRZ source rocks (37% each), less from the Kingak Shale (26%), and little or no contribution from other source rocks. These results differ from published interpretations that most oil in the Prudhoe Bay Field originated from the Shublik Formation source rock. With few exceptions, the relative contribution of oil from the Shublik Formation decreases, while that from the Hue-GRZ increases in reservoirs along the Barrow arch from Point Barrow in the northwest to Point Thomson in the southeast (???250 miles or 400 km). The Shublik contribution also decreases to a lesser degree between fault blocks within the Ivishak pool from west to east across the Prudhoe Bay Field. ALS-C provides a robust means to calculate the relative amounts of two or more oil types in a mixture. Furthermore, ALS-C does not require that pure end member oils be identified prior to analysis or that laboratory mixtures of these oils be prepared to evaluate mixing. ALS-C of biomarkers reliably de-convolutes mixtures because the concentrations of compounds in mixtures vary as linear functions of the amount of each oil type. ALS of biomarker ratios (ALS-R) cannot be used to de-convolute mixtures because compound ratios vary as nonlinear functions of the amount of each oil type.

  11. National Assessment of Oil and Gas Project: geologic assessment of undiscovered gas hydrate resources on the North Slope, Alaska

    Science.gov (United States)

    USGS AK Gas Hydrate Assessment Team: Collett, Timothy S.; Agena, Warren F.; Lee, Myung Woong; Lewis, Kristen A.; Zyrianova, Margarita; Bird, Kenneth J.; Charpentier, Ronald R.; Cook, Troy A.; Houseknecht, David W.; Klett, Timothy R.; Pollastro, Richard M.

    2014-01-01

    Scientists with the U.S. Geological Survey have completed the first assessment of the undiscovered, technically recoverable gas hydrate resources beneath the North Slope of Alaska. This assessment indicates the existence of technically recoverable gas hydrate resources—that is, resources that can be discovered, developed, and produced using current technology. The approach used in this assessment followed standard geology-based USGS methodologies developed to assess conventional oil and gas resources. In order to use the USGS conventional assessment approach on gas hydrate resources, three-dimensional industry-acquired seismic data were analyzed. The analyses indicated that the gas hydrates on the North Slope occupy limited, discrete volumes of rock bounded by faults and downdip water contacts. This assessment approach also assumes that the resource can be produced by existing conventional technology, on the basis of limited field testing and numerical production models of gas hydrate-bearing reservoirs. The area assessed in northern Alaska extends from the National Petroleum Reserve in Alaska on the west through the Arctic National Wildlife Refuge on the east and from the Brooks Range northward to the State-Federal offshore boundary (located 3 miles north of the coastline). This area consists mostly of Federal, State, and Native lands covering 55,894 square miles. Using the standard geology-based assessment methodology, the USGS estimated that the total undiscovered technically recoverable natural-gas resources in gas hydrates in northern Alaska range between 25.2 and 157.8 trillion cubic feet, representing 95 percent and 5 percent probabilities of greater than these amounts, respectively, with a mean estimate of 85.4 trillion cubic feet.

  12. Geologic controls on gas hydrate occurrence in the Mount Elbert prospect, Alaska North Slope

    Science.gov (United States)

    Boswell, R.; Rose, K.; Collett, T.S.; Lee, M.; Winters, W.; Lewis, K.A.; Agena, W.

    2011-01-01

    Data acquired at the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well, drilled in the Milne Point area of the Alaska North Slope in February, 2007, indicates two zones of high gas hydrate saturation within the Eocene Sagavanirktok Formation. Gas hydrate is observed in two separate sand reservoirs (the D and C units), in the stratigraphically highest portions of those sands, and is not detected in non-sand lithologies. In the younger D unit, gas hydrate appears to fill much of the available reservoir space at the top of the unit. The degree of vertical fill with the D unit is closely related to the unit reservoir quality. A thick, low-permeability clay-dominated unit serves as an upper seal, whereas a subtle transition to more clay-rich, and interbedded sand, silt, and clay units is associated with the base of gas hydrate occurrence. In the underlying C unit, the reservoir is similarly capped by a clay-dominated section, with gas hydrate filling the relatively lower-quality sands at the top of the unit leaving an underlying thick section of high-reservoir quality sands devoid of gas hydrate. Evaluation of well log, core, and seismic data indicate that the gas hydrate occurs within complex combination stratigraphic/structural traps. Structural trapping is provided by a four-way fold closure augmented by a large western bounding fault. Lithologic variation is also a likely strong control on lateral extent of the reservoirs, particularly in the D unit accumulation, where gas hydrate appears to extend beyond the limits of the structural closure. Porous and permeable zones within the C unit sand are only partially charged due most likely to limited structural trapping in the reservoir lithofacies during the period of primary charging. The occurrence of the gas hydrate within the sands in the upper portions of both the C and D units and along the crest of the fold is consistent with an interpretation that these deposits are converted free gas accumulations

  13. ARM-ACME V: ARM Airborne Carbon Measurements V on the North Slope of Alaska Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Biraud, Sebastien C [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-05-01

    Atmospheric temperatures are warming faster in the Arctic than predicted by climate models. The impact of this warming on permafrost degradation is not well understood, but it is projected to increase carbon decomposition and greenhouse gas production (CO2 and/or CH4) by arctic ecosystems. Airborne observations of atmospheric trace gases, aerosols and cloud properties in North Slopes of Alaska (NSA) are improving our understanding of global climate, with the goal of reducing the uncertainty in global and regional climate simulations and projections. From June 1 through September 15, 2015, AAF deployed the G1 research aircraft and flew over the North Slope of Alaska (38 flights, 140 science flight hours), with occasional vertical profiling over Prudhoe Bay, Oliktok point, Barrow, Atqasuk, Ivotuk, and Toolik Lake. The aircraft payload included Picarro and Los Gatos Research (LGR) analyzers for continuous measurements of CO2, CH4, H2O, and CO and N2O mixing ratios, and a 12-flask sampler for analysis of carbon cycle gases (CO2, CO, CH4, N2O, 13CO2, and trace hydrocarbon species). The aircraft payload also include measurements of aerosol properties (number size distribution, total number concentration, absorption, and scattering), cloud properties (droplet and ice size information), atmospheric thermodynamic state, and solar/infrared radiation.

  14. Dinosaurs on the North Slope, Alaska: High latitude, latest cretaceous environments

    Science.gov (United States)

    Brouwers, E.M.; Clemens, W.A.; Spicer, R.A.; Ager, T.A.; Carter, L.D.; Sliter, W.V.

    1987-01-01

    Abundant skeletal remains demonstrate that lambeosaurine hadrosaurid, tyrannosaurid, and troodontid dinosaurs lived on the Alaskan North Slope during late Campanian-early Maestrichtian time (about 66 to 76 million years ago) in a deltaic environment dominated by herbaceous vegetation. The high ground terrestrial plant community was a mild- to cold-temperate forest composed of coniferous and broad leaf trees. The high paleolatitude (about 70?? to 85?? North) implies extreme seasonal variation in solar insolation, temperature, and herbivore food supply. Great distances of migration to contemporaneous evergreen floras and the presence of both juvenile and adult hadrosaurs suggest that they remained at high latitudes year-round. This challenges the hypothesis that short-term periods of darkness and temperature decrease resulting from a bolide impact caused dinosaurian extinction.

  15. Gas Production From a Cold, Stratigraphically Bounded Hydrate Deposit at the Mount Elbert Site, North Slope, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Moridis, G.J.; Silpngarmlert, S.; Reagan, M. T.; Collett, T.S.; Zhang, K.

    2009-09-01

    As part of an effort to identify suitable targets for a planned long-term field test, we investigate by means of numerical simulation the gas production potential from unit D, a stratigraphically bounded (Class 3) permafrost-associated hydrate occurrence penetrated in the ount Elbert well on North Slope, Alaska. This shallow, low-pressure deposit has high porosities, high intrinsic permeabilities and high hydrate saturations. It has a low temperature because of its proximity to the overlying permafrost. The simulation results indicate that vertical ells operating at a constant bottomhole pressure would produce at very low rates for a very long period. Horizontal wells increase gas production by almost two orders of magnitude, but production remains low. Sensitivity analysis indicates that the initial deposit temperature is y the far the most important factor determining production performance (and the most effective criterion for target selection) because it controls the sensible heat available to fuel dissociation.

  16. Distribution, richness, quality, and thermal maturity of source rock units on the North Slope of Alaska

    Science.gov (United States)

    Peters, K.E.; Bird, K.J.; Keller, M.A.; Lillis, P.G.; Magoon, L.B.

    2003-01-01

    Four source rock units on the North Slope were identified, characterized, and mapped to better understand the origin of petroleum in the area: Hue-gamma ray zone (Hue-GRZ), pebble shale unit, Kingak Shale, and Shublik Formation. Rock-Eval pyrolysis, total organic carbon analysis, and well logs were used to map the present-day thickness, organic quantity (TOC), quality (hydrogen index, HI), and thermal maturity (Tmax) of each unit. To map these units, we screened all available geochemical data for wells in the study area and assumed that the top and bottom of the oil window occur at Tmax of ~440° and 470°C, respectively. Based on several assumptions related to carbon mass balance and regional distributions of TOC, the present-day source rock quantity and quality maps were used to determine the extent of fractional conversion of the kerogen to petroleum and to map the original organic richness prior to thermal maturation.

  17. Seismic analysis of clinoform depositional sequences and shelf-margin trajectories in Lower Cretaceous (Albian) strata, Alaska North Slope

    Science.gov (United States)

    Houseknecht, D.W.; Bird, K.J.; Schenk, C.J.

    2009-01-01

    Lower Cretaceous strata beneath the Alaska North Slope include clinoform depositional sequences that filled the western Colville foreland basin and overstepped the Beaufort rift shoulder. Analysis of Albian clinoform sequences with two-dimensional (2D) seismic data resulted in the recognition of seismic facies inferred to represent lowstand, transgressive and highstand systems tracts. These are stacked to produce shelf-margin trajectories that appear in low-resolution seismic data to alternate between aggradational and progradational. Higher-resolution seismic data reveal shelf-margin trajectories that are more complex, particularly in net-aggradational areas, where three patterns commonly are observed: (1) a negative (downward) step across the sequence boundary followed by mostly aggradation in the lowstand systems tract (LST), (2) a positive (upward) step across the sequence boundary followed by mostly progradation in the LST and (3) an upward backstep across a mass-failure d??collement. These different shelf-margin trajectories are interpreted as (1) fall of relative sea level below the shelf edge, (2) fall of relative sea level to above the shelf edge and (3) mass-failure removal of shelf-margin sediment. Lowstand shelf margins mapped using these criteria are oriented north-south in the foreland basin, indicating longitudinal filling from west to east. The shelf margins turn westward in the north, where the clinoform depositional system overstepped the rift shoulder, and turn eastward in the south, suggesting progradation of depositional systems from the ancestral Brooks Range into the foredeep. Lowstand shelf-margin orientations are consistently perpendicular to clinoform-foreset-dip directions. Although the Albian clinoform sequences of the Alaska North Slope are generally similar in stratal geometry to clinoform sequences elsewhere, they are significantly thicker. Clinoform-sequence thickness ranges from 600-1000 m in the north to 1700-2000 m in the south

  18. Well log analysis to assist the interpretation of 3-D seismic data at Milne Point, north slope of Alaska

    Science.gov (United States)

    Lee, Myung W.

    2005-01-01

    In order to assess the resource potential of gas hydrate deposits in the North Slope of Alaska, 3-D seismic and well data at Milne Point were obtained from BP Exploration (Alaska), Inc. The well-log analysis has three primary purposes: (1) Estimate gas hydrate or gas saturations from the well logs; (2) predict P-wave velocity where there is no measured P-wave velocity in order to generate synthetic seismograms; and (3) edit P-wave velocities where degraded borehole conditions, such as washouts, affected the P-wave measurement significantly. Edited/predicted P-wave velocities were needed to map the gas-hydrate-bearing horizons in the complexly faulted upper part of 3-D seismic volume. The estimated gas-hydrate/gas saturations from the well logs were used to relate to seismic attributes in order to map regional distribution of gas hydrate inside the 3-D seismic grid. The P-wave velocities were predicted using the modified Biot-Gassmann theory, herein referred to as BGTL, with gas-hydrate saturations estimated from the resistivity logs, porosity, and clay volume content. The effect of gas on velocities was modeled using the classical Biot-Gassman theory (BGT) with parameters estimated from BGTL.

  19. High latitude meteoric δ18O compositions: Paleosol siderite in the Middle Cretaceous Nanushuk Formation, North Slope, Alaska

    Science.gov (United States)

    Ufnar, David F.; Ludvigson, Greg A.; Gonzalez, Luis A.; Brenner, Richard L.; Witzke, Brian J.

    2004-01-01

    Siderite-bearing pedogenic horizons of the Nanushuk Formation of the North Slope, Alaska, provide a critical high paleolatitude oxygen isotopic proxy record of paleoprecipitation, supplying important empirical data needed for paleoclimatic reconstructions and models of "greenhouse-world" precipitation rates. Siderite ??18O values were determined from four paleosol horizons in the National Petroleum Reserve Alaska (NPR-A) Grandstand # 1 Core, and the values range between -17.6??? and -14.3??? Peedee belemnite (PDB) with standard deviations generally less than 0.6??? within individual horizons. The ??13C values are much more variable, ranging from -4.6??? to +10.8??? PDB. A covariant ??18O versus ??13C trend in one horizon probably resulted from mixing between modified marine and meteoric phreatic fluids during siderite precipitation. Groundwater values calculated from siderite oxygen isotopic values and paleobotanical temperature estimates range from -23.0??? to -19.5??? standard mean ocean water (SMOW). Minor element analyses show that the siderites are impure, having enrichments in Ca, Mg, Mn, and Sr. Minor element substitutions and Mg/Fe and Mg/ (Ca + Mg) ratios also suggest the influence of marine fluids upon siderite precipitation. The pedogenic horizons are characterized by gleyed colors, rare root traces, abundant siderite, abundant organic matter, rare clay and silty clay coatings and infillings, some preservation of primary sedimentary stratification, and a lack of ferruginous oxides and mottles. The pedogenic features suggest that these were poorly drained, reducing, hydromorphic soils that developed in coal-bearing delta plain facies and are similar to modern Inceptisols. Model-derived estimates of precipitation rates for the Late Albian of the North Slope, Alaska (485-626 mm/yr), are consistent with precipitation rates necessary to maintain modern peat-forming environments. This information reinforces the mutual consistency between empirical

  20. Evaluation of Wax Deposition and Its Control During Production of Alaska North Slope Oils

    Energy Technology Data Exchange (ETDEWEB)

    Tao Zhu; Jack A. Walker; J. Liang

    2008-12-31

    Due to increasing oil demand, oil companies are moving into arctic environments and deep-water areas for oil production. In these regions of lower temperatures, wax deposits begin to form when the temperature in the wellbore falls below wax appearance temperature (WAT). This condition leads to reduced production rates and larger pressure drops. Wax problems in production wells are very costly due to production down time for removal of wax. Therefore, it is necessary to develop a solution to wax deposition. In order to develop a solution to wax deposition, it is essential to characterize the crude oil and study phase behavior properties. The main objective of this project was to characterize Alaskan North Slope crude oil and study the phase behavior, which was further used to develop a dynamic wax deposition model. This report summarizes the results of the various experimental studies. The subtasks completed during this study include measurement of density, molecular weight, viscosity, pour point, wax appearance temperature, wax content, rate of wax deposition using cold finger, compositional characterization of crude oil and wax obtained from wax content, gas-oil ratio, and phase behavior experiments including constant composition expansion and differential liberation. Also, included in this report is the development of a thermodynamic model to predict wax precipitation. From the experimental study of wax appearance temperature, it was found that wax can start to precipitate at temperatures as high as 40.6 C. The WAT obtained from cross-polar microscopy and viscometry was compared, and it was discovered that WAT from viscometry is overestimated. From the pour point experiment it was found that crude oil can cease to flow at a temperature of 12 C. From the experimental results of wax content, it is evident that the wax content in Alaskan North Slope crude oil can be as high as 28.57%. The highest gas-oil ratio for a live oil sample was observed to be 619.26 SCF

  1. Using a Neural Network to Determine the Hatch Status of the AERI at the ARM North Slope of Alaska Site

    Energy Technology Data Exchange (ETDEWEB)

    Zwink, AB; Turner, DD

    2012-03-19

    The fore-optics of the Atmospheric Emitted Radiance Interferometer (AERI) are protected by an automated hatch to prevent precipitation from fouling the instrument's scene mirror (Knuteson et al. 2004). Limit switches connected with the hatch controller provide a signal of the hatch state: open, closed, undetermined (typically associated with the hatch being between fully open or fully closed during the instrument's sky view period), or an error condition. The instrument then records the state of the hatch with the radiance data so that samples taken when the hatch is not open can be removed from any subsequent analysis. However, the hatch controller suffered a multi-year failure for the AERI located at the ARM North Slope of Alaska (NSA) Central Facility in Barrow, Alaska, from July 2006-February 2008. The failure resulted in misreporting the state of the hatch in the 'hatchOpen' field within the AERI data files. With this error there is no simple solution to translate what was reported back to the correct hatch status, thereby making it difficult for an analysis to determine when the AERI was actually viewing the sky. As only the data collected when the hatch is fully open are scientifically useful, an algorithm was developed to determine whether the hatch was open or closed based on spectral radiance data from the AERI. Determining if the hatch is open or closed in a scene with low clouds is non-trivial, as low opaque clouds may look very similar spectrally as the closed hatch. This algorithm used a backpropagation neural network; these types of neural networks have been used with increasing frequency in atmospheric science applications.

  2. Increased wetness confounds Landsat-derived NDVI trends in the central Alaska North Slope region, 1985-2011

    Science.gov (United States)

    Raynolds, Martha K.; Walker, Donald A.

    2016-08-01

    Satellite data from the circumpolar Arctic have shown increases in vegetation indices correlated to warming air temperatures (e.g. Bhatt et al 2013 Remote Sensing 5 4229-54). However, more information is needed at finer scales to relate the satellite trends to vegetation changes on the ground. We examined changes using Landsat TM and ETM+ data between 1985 and 2011 in the central Alaska North Slope region, where the vegetation and landscapes are relatively well-known and mapped. We calculated trends in the normalized difference vegetation index (NDVI) and tasseled-cap transformation indices, and related them to high-resolution aerial photographs, ground studies, and vegetation maps. Significant, mostly negative, changes in NDVI occurred in 7.3% of the area, with greater change in aquatic and barren types. Large reflectance changes due to erosion, deposition and lake drainage were evident. Oil industry-related changes such as construction of artificial islands, roads, and gravel pads were also easily identified. Regional trends showed decreases in NDVI for most vegetation types, but increases in tasseled-cap greenness (56% of study area, greatest for vegetation types with high shrub cover) and tasseled-cap wetness (11% of area), consistent with documented degradation of polygon ice wedges, indicating that increasing cover of water may be masking increases in vegetation when summarized using the water-sensitive NDVI.

  3. Experimental study of solvent-based emulsion injection to enhance heavy oil recovery in Alaska North Slope area

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, F.; Mamora, D. [Texas A and M Univ., College Station, TX (United States)

    2010-07-01

    This study examined the feasibility of using a chemical enhanced oil recovery method to overcome some of the technical challenges associated with thermal recovery in the Alaska North Slope (ANS). This paper described the second stage research of an experimental study on nano-particle and surfactant-stabilized solvent-based emulsions for the ANS area. Four successful core flood experiments were performed using heavy ANS oil. The runs included water flooding followed by emulsion flooding; and pure emulsion injection core flooding. The injection rate and core flooding temperature remained constant and only 1 PV micro-emulsion was injected after breakthrough under water flooding or emulsion flooding. Oil recovery increased by 26.4 percent from 56.2 percent original oil in place (OOIP) with waterflooding to 82.6 percent OOIP with injection of emulsion following water flooding. Oil recovery was slightly higher with pure emulsion flooding, at 85.8 percent OOIP. The study showed that low permeability generally resulted in a higher shear rate, which is favourable for in-situ emulsification and higher displacement efficiency. 11 refs., 4 tabs., 20 figs.

  4. Scientific Infrastructure To Support Manned And Unmanned Aircraft, Tethered Balloons, And Related Aerial Activities At Doe Arm Facilities On The North Slope Of Alaska

    Science.gov (United States)

    Ivey, M.; Dexheimer, D.; Hardesty, J.; Lucero, D. A.; Helsel, F.

    2015-12-01

    The U.S. Department of Energy (DOE), through its scientific user facility, the Atmospheric Radiation Measurement (ARM) facilities, provides scientific infrastructure and data to the international Arctic research community via its research sites located on the North Slope of Alaska. DOE has recently invested in improvements to facilities and infrastructure to support operations of unmanned aerial systems for science missions in the Arctic and North Slope of Alaska. A new ground facility, the Third ARM Mobile Facility, was installed at Oliktok Point Alaska in 2013. Tethered instrumented balloons were used to make measurements of clouds in the boundary layer including mixed-phase clouds. A new Special Use Airspace was granted to DOE in 2015 to support science missions in international airspace in the Arctic. Warning Area W-220 is managed by Sandia National Laboratories for DOE Office of Science/BER. W-220 was successfully used for the first time in July 2015 in conjunction with Restricted Area R-2204 and a connecting Altitude Reservation Corridor (ALTRV) to permit unmanned aircraft to operate north of Oliktok Point. Small unmanned aircraft (DataHawks) and tethered balloons were flown at Oliktok during the summer and fall of 2015. This poster will discuss how principal investigators may apply for use of these Special Use Airspaces, acquire data from the Third ARM Mobile Facility, or bring their own instrumentation for deployment at Oliktok Point, Alaska. The printed poster will include the standard DOE funding statement.

  5. C-N-P interactions control climate driven changes in regional patterns of C storage on the North Slope of Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Yueyang; Rocha, Adrian; Rastetter, Edward; Shaver, Gaius; Mishra, U.; Zhuang, Qianlai; Kwiatkowski, Bonnie

    2016-01-01

    As climate warms, changes in the carbon (C) balance of arctic tundra will play an important role in the global C balance. The C balance of tundra is tightly coupled to the nitrogen (N) and phosphorus (P) cycles because soil organic matter is the principal source of plant-available nutrients and determines the spatial variation of vegetation biomass across the North Slope of Alaska. Warming will accelerate these nutrient cycles, which should stimulate plant growth.

  6. Brood rearing ecology of king eiders on the north slope of Alaska

    Science.gov (United States)

    Phillips, Laura M.; Powell, Abby N.

    2009-01-01

    We examined King Eider (Somateria spectabilis) brood survival in the Kuparak oil field in northern Alaska in 2002 and 2003 by monitoring hens with broods using radiotelemetry. We observed complete brood loss in eight of 10 broods. Broods survived less than 2 weeks on average, and most mortality occurred within 10 days of hatch. Distance hens traveled overland did not affect brood survival. Apparent King Eider brood survival in our study area was lower than reported for eider species in other areas. We recommend future studies examine if higher densities of predators in oil fields reduces King Eider duckling survival.

  7. Vertical and Spatial Profiling of Arctic Black Carbon on the North Slope of Alaska 2015: Comparison of Model and Observation

    Science.gov (United States)

    Sedlacek, A. J., III; Feng, Y.; Biraud, S.; Springston, S. R.

    2015-12-01

    One of the major issues confronting aerosol climate simulations of the Arctic and Antarctic Cryospheres is the lack of detailed data on the vertical and spatial distribution of aerosols with which to test these models. This is due, in part, to the inherent difficulty of conducting such measurements in extreme environments. One class of under measured radiative forcing agents in the Polar Region is the absorbing aerosol - black carbon and brown carbon. In particular, vertical profile information of BC is critical in reducing uncertainty in model assessment of aerosol radiative impact at high latitudes. During the summer of 2015, a Single-Particle Soot Photometer (SP2) was deployed aboard the Department of Energy (DOE) Gultstream-1 (G-1) aircraft to measure refractory BC (rBC) concentrations as part of the DOE-sponsored ACME-V (ARM Airborne Carbon Measurements) campaign. This campaign was conducted from June through to mid-September along the North Slope of Alaska and was punctuated by vertical profiling over 5 sites (Atquasuk, Barrow, Ivotuk, Oliktok, and Toolik). In addition, measurement of CO, CO2 and CH4were also taken to provide information on the spatial and seasonal differences in GHG sources and how these sources correlate with BC. Lastly, these aerosol and gas measurements provide an important dataset to assess the representativeness of ground sites at regional scales. Comparisons between observations and a global climate model (CAM5) simulations will be agumented with a discussion on the capability of the model to capture observed monthly mean profiles of BC and stratified aerosol layers. Additionally, the ability of the SP2 to partition rBC-containing particles into nascent or aged species allows an evaluation of how well the CAM5 model captures aging of long distant transported carbonaceous aerosols. Finally model sensitivity studies will be aso be presented that investigated the relative importance of the different emission sectors to the summer Arctic

  8. Phase Behavior, Solid Organic Precipitation, and Mobility Characterization Studies in Support of Enhanced Heavy Oil Recovery on the Alaska North Slope

    Energy Technology Data Exchange (ETDEWEB)

    Shirish Patil; Abhijit Dandekar; Santanu Khataniar

    2008-12-31

    The medium-heavy oil (viscous oil) resources in the Alaska North Slope are estimated at 20 to 25 billion barrels. These oils are viscous, flow sluggishly in the formations, and are difficult to recover. Recovery of this viscous oil requires carefully designed enhanced oil recovery processes. Success of these recovery processes is critically dependent on accurate knowledge of the phase behavior and fluid properties, especially viscosity, of these oils under variety of pressure and temperature conditions. This project focused on predicting phase behavior and viscosity of viscous oils using equations of state and semi-empirical correlations. An experimental study was conducted to quantify the phase behavior and physical properties of viscous oils from the Alaska North Slope oil field. The oil samples were compositionally characterized by the simulated distillation technique. Constant composition expansion and differential liberation tests were conducted on viscous oil samples. Experiment results for phase behavior and reservoir fluid properties were used to tune the Peng-Robinson equation of state and predict the phase behavior accurately. A comprehensive literature search was carried out to compile available compositional viscosity models and their modifications, for application to heavy or viscous oils. With the help of meticulously amassed new medium-heavy oil viscosity data from experiments, a comparative study was conducted to evaluate the potential of various models. The widely used corresponding state viscosity model predictions deteriorate when applied to heavy oil systems. Hence, a semi-empirical approach (the Lindeloff model) was adopted for modeling the viscosity behavior. Based on the analysis, appropriate adjustments have been suggested: the major one is the division of the pressure-viscosity profile into three distinct regions. New modifications have improved the overall fit, including the saturated viscosities at low pressures. However, with the limited

  9. ICESat GLAS Elevation Changes and ALOS PALSAR InSAR Line-Of-Sight Changes on the Continuous Permafrost Zone of the North Slope, Alaska

    Science.gov (United States)

    Muskett, Reginald

    2016-04-01

    Measuring centimeter-scale and smaller surface changes by satellite-based systems on the periglacial terrains and permafrost zones of the northern hemisphere is an ongoing challenge. We are investigating this challenge by using data from the NASA Ice, Cloud, and land Elevation Satellite Geoscience Laser Altimeter System (ICESat GLAS) and the JAXA Advanced Land Observing Satellite Phased Array type L-band Synthetic Aperture Radar (ALOS PALSAR) on the continuous permafrost zone of the North Slope, Alaska. Using the ICESat GLAS exact-repeat profiles in the analysis of ALOS PALSAR InSAR Line-Of-Sight (LOS) changes we find evidence of volume scattering over much of the tundra vegetation covered active-layer and surface scattering from river channel/banks (deposition and erosion), from rock outcropping bluffs and ridges. Pingos, ice-cored mounds common to permafrost terrains can be used as benchmarks for assessment of LOS changes. For successful InSAR processing, topographic and tropospheric phase cannot be assumed negligible and must be removed. The presence of significant troposphere phase in short-period repeat interferograms renders stacking ill suited for the task of deriving verifiable centimeter-scale surface deformation phase and reliable LOS changes. Ref.: Muskett, R.R. (2015), ICESat GLAS Elevation Changes and ALOS PALSAR InSAR Line-Of-Sight Changes on the Continuous Permafrost Zone of the North Slope, Alaska. International Journal of Geosciences, 6 (10), 1101-1115. doi:10.4236/ijg.2015.610086 http://www.scirp.org/Journal/PaperDownload.aspx?paperID=60406

  10. Evaluation of a deposit in the vicinity of the PBU L-106 Site, North Slope, Alaska, for a potential long-term test of gas production from hydrates

    Energy Technology Data Exchange (ETDEWEB)

    Moridis, G.J.; Reagan, M.T.; Boyle, K.L.; Zhang, K.

    2010-05-01

    As part of the effort to investigate the technical feasibility of gas production from hydrate deposits, a long-term field test (lasting 18-24 months) is under consideration in a project led by the U.S. Department of Energy. We evaluate a candidate deposit involving the C-Unit in the vicinity of the PBU-L106 site in North Slope, Alaska. This deposit is stratigraphically bounded by impermeable shale top and bottom boundaries (Class 3), and is characterized by high intrinsic permeabilities, high porosity, high hydrate saturation, and a hydrostatic pressure distribution. The C-unit deposit is composed of two hydrate-bearing strata separated by a 30-ft-thick shale interlayer, and its temperatrure across its boundaries ranges between 5 and 6.5 C. We investigate by means of numerical simulation involving very fine grids the production potential of these two deposits using both vertical and horizontal wells. We also explore the sensitivity of production to key parameters such as the hydrate saturation, the formation permeability, and the permeability of the bounding shale layers. Finally, we compare the production performance of the C-Unit at the PBU-L106 site to that of the D-Unit accumulation at the Mount Elbert site, a thinner, single-layer Class 3 deposit on the North Slope of Alaska that is shallower, less-pressurized and colder (2.3-2.6 C). The results indicate that production from horizontal wells may be orders of magnitude larger than that from vertical ones. Additionally, production increases with the formation permeability, and with a decreasing permeability of the boundaries. The effect of the hydrate saturation on production is complex and depends on the time frame of production. Because of higher production, the PBU-L106 deposit appears to have an advantage as a candidate for the long-term test.

  11. Source Characterization and Temporal Variation of Methane Seepage from Thermokarst Lakes on the Alaska North Slope in Response to Arctic Climate Change

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2012-09-30

    The goals of this research were to characterize the source, magnitude and temporal variability of methane seepage from thermokarst lakes (TKL) within the Alaska North Slope gas hydrate province, assess the vulnerability of these areas to ongoing and future arctic climate change and determine if gas hydrate dissociation resulting from permafrost melting is contributing to the current lake emissions. Analyses were focused on four main lake locations referred to in this report: Lake Qalluuraq (referred to as Lake Q) and Lake Teshekpuk (both on Alaska's North Slope) and Lake Killarney and Goldstream Bill Lake (both in Alaska's interior). From analyses of gases coming from lakes in Alaska, we showed that ecological seeps are common in Alaska and they account for a larger source of atmospheric methane today than geologic subcap seeps. Emissions from the geologic source could increase with potential implications for climate warming feedbacks. Our analyses of TKL sites showing gas ebullition were complemented with geophysical surveys, providing important insight about the distribution of shallow gas in the sediments and the lake bottom manifestation of seepage (e.g., pockmarks). In Lake Q, Chirp data were limited in their capacity to image deeper sediments and did not capture the thaw bulb. The failure to capture the thaw bulb at Lake Q may in part be related to the fact that the present day lake is a remnant of an older, larger, and now-partially drained lake. These suggestions are consistent with our analyses of a dated core of sediment from the lake that shows that a wetland has been present at the site of Lake Q since approximately 12,000 thousand years ago. Chemical analyses of the core indicate that the availability of methane at the site has changed during the past and is correlated with past environmental changes (i.e. temperature and hydrology) in the Arctic. Discovery of methane seeps in Lake Teshekpuk in the northernmost part of the lake during 2009

  12. Petroleum source potential of the Lower Cretaceous mudstone succession of the NPRA and Colville Delta area, North Slope Alaska, based on sonic and resistivity logs

    Science.gov (United States)

    Keller, Margaret A.; Bird, Kenneth J.

    2003-01-01

    Resource assessment of the North Slope of Alaska by the U. S. Geological Survey includes evaluation of the petroleum source potential of Mesozoic and Cenozoic rocks using the delta log R technique (Passey and others, 1990). Porosity and resistivity logs are used in combination with thermal maturity data to produce a continuous profile of total organic carbon content in weight % (TOC). From the pattern and amount of TOC in the profile produced, the depositional setting and thus the petroleum source-rock potential (kerogen type) of the organic matter can be inferred and compared to interpretations from other data such as Rock-Eval pyrolysis. TOC profiles determined by this technique for the contiguous interval of pebble shale unit, Hue Shale (including the Gamma Ray Zone or GRZ), and lower part of the Torok Formation indicate important potential for petroleum generation in the Tunalik 1, Inigok 1, N. Inigok 1, Kuyanak 1, Texaco Colville Delta 1, Nechelik 1, and Bergschrund 1 wells of the western North Slope region. TOC profiles suggest that this interval contains both type II and III kerogens – consistent with proposed depositional models -- and is predominantly greater than 2 wt. % TOC (cut-off used for effective source potential). Average TOC for the total effective section of the pebble shale unit + Hue Shale ranges from 2.6 to 4.1 wt % TOC (values predominantly 2-8% TOC) over 192-352 ft. Source potential for the lower Torok Formation, which also has interbedded sandstone and lean mudstone, is good to negligible in these 7 wells.

  13. US North Slope gas and Asian LNG markets

    Science.gov (United States)

    Attanasi, E.D.

    1994-01-01

    Prospects for export of liquified natural gas (LNG) from Alaska's North Slope are assessed. Projected market conditions to 2010 show that new LNG capacity beyond announced expansions will be needed to meet regional demand and that supplies will probably come from outside the region. The estimated delivered costs of likely suppliers show that Alaska North Slope gas will not be competitive. The alternative North Slope gas development strategies of transport and sale to the lower 48 states and use on the North Slope for either enhanced oil recovery or conversion to liquids are examined. The alternative options require delaying development until US gas prices increase, exhaustion of certain North Slope oil fields, or advances occur in gas to liquid fuels conversion technology. ?? 1995.

  14. 77 FR 14006 - Proposed Development of the Alaska Stand Alone Gas Pipeline Project (ASAP), From the North Slope...

    Science.gov (United States)

    2012-03-08

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF DEFENSE Department of the Army, Corps of Engineers Proposed Development of the Alaska Stand Alone Gas Pipeline... January 20, 2012, issue of the Federal Register (77 FR No. 13), the U.S. Army Corps of Engineers...

  15. THE HYDRAULIC CHARACTERISTICS AND GEOCHEMISTRY OF HYPORHEIC AND PARAFLUVIAL ZONES IN ARCTIC TUNDRA STREAMS, NORTH SLOPE, ALASKA

    Science.gov (United States)

    Sodium bromide and Rhodamine WT were used as conservative tracers to examine the hydrologic characteristics of seven tundra streams in Arctic Alaska, during the summers of 1994-1996. Continuous tracer additions were conducted in seven rivers ranging from 1st to 5th order with sam...

  16. Late Mesozoic and Cenozoic thermotectonic evolution of the central Brooks Range and adjacent North Slope foreland basin, Alaska: Including fission track results from the Trans-Alaska Crustal Transect (TACT)

    Science.gov (United States)

    O'Sullivan, P. B.; Murphy, J.M.; Blythe, A.E.

    1997-01-01

    Apatite fission track data are used to evaluate the thermal and tectonic history of the central Brooks Range and the North Slope foreland basin in northern Alaska along the northern leg of the Trans-Alaska Crustal Transect (TACT). Fission track analyses of the detrital apatite grains in most sedimentary units resolve the timing of structures and denudation within the Brooks Range, ranging in scale from the entire mountain range to relatively small-scale folds and faults. Interpretation of the results indicates that rocks exposed within the central Brooks Range cooled rapidly from paleotemperatures 110?? to 50??C during discrete episodes at ???100??5 Ma, ???60??4 Ma, and ???24??3 Ma, probably in response to kilometer-scale denudation. North of the mountain front, rocks in the southern half of the foreland basin were exposed to maximum paleotemperatures 110??C in the Late Cretaceous to early Paleocene as a result of burial by Upper Jurassic and Cretaceous sedimentary rocks. Rapid cooling from these elevated paleotemperatures also occurred due to distinct episodes of kilometer-scale denudation at ???60??4 Ma, 46??3 Ma, 35??2 Ma, and ???24??3 Ma. Combined, the apatite analyses indicate that rocks exposed along the TACT line through the central Brooks Range and foreland basin experienced episodic rapid cooling throughout the Late Cretaceous and Cenozoic in response to at least three distinct kilometer-scale denudation events. Future models explaining orogenic events in northern Alaska must consider these new constraints from fission track thermochronology. Copyright 1997 by the American Geophysical Union.

  17. Gas production from a cold, stratigraphically-bounded gas hydrate deposit at the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope: Implications of uncertainties

    Science.gov (United States)

    Moridis, G.J.; Silpngarmlert, S.; Reagan, M.T.; Collett, T.; Zhang, K.

    2011-01-01

    As part of an effort to identify suitable targets for a planned long-term field test, we investigate by means of numerical simulation the gas production potential from unit D, a stratigraphically bounded (Class 3) permafrost-associated hydrate occurrence penetrated in the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well on North Slope, Alaska. This shallow, low-pressure deposit has high porosities (?? = 0.4), high intrinsic permeabilities (k = 10-12 m2) and high hydrate saturations (SH = 0.65). It has a low temperature (T = 2.3-2.6 ??C) because of its proximity to the overlying permafrost. The simulation results indicate that vertical wells operating at a constant bottomhole pressure would produce at very low rates for a very long period. Horizontal wells increase gas production by almost two orders of magnitude, but production remains low. Sensitivity analysis indicates that the initial deposit temperature is by the far the most important factor determining production performance (and the most effective criterion for target selection) because it controls the sensible heat available to fuel dissociation. Thus, a 1 ??C increase in temperature is sufficient to increase the production rate by a factor of almost 8. Production also increases with a decreasing hydrate saturation (because of a larger effective permeability for a given k), and is favored (to a lesser extent) by anisotropy. ?? 2010.

  18. On the relationship between Arctic ice clouds and polluted air masses over the north slope of Alaska in April 2008

    Directory of Open Access Journals (Sweden)

    C. Jouan

    2013-02-01

    Full Text Available Recently, two Types of Ice Clouds (TICs properties have been characterized using ISDAC airborne measurements (Alaska, April 2008. TIC-2B were characterized by fewer (<10 L−1 and larger (>110 μm ice crystals, a larger ice supersaturation (>15% and a fewer ice nuclei (IN concentration (<2 order of magnitude when compared to TIC-1/2A. It has been hypothesized that emissions of SO2 may reduce the ice nucleating properties of IN through acidification, resulting to a smaller concentration of larger ice crystals and leading to precipitation (e.g. cloud regime TIC-2B because of the reduced competition for the same available moisture.

    Here, the origin of air masses forming the ISDAC TIC-1/2A (1 April 2008 and TIC-2B (15 April 2008 is investigated using trajectory tools and satellite data. Results show that the synoptic conditions favor air masses transport from the three potentials SO2 emission areas to Alaska: eastern China and Siberia where anthropogenic and biomass burning emission respectively are produced and the volcanic region from the Kamchatka/Aleutians. Weather conditions allow the accumulation of pollutants from eastern China/Siberia over Alaska, most probably with the contribution of acid volcanic aerosol during the TIC-2B period. OMI observations reveal that SO2 concentrations in air masses forming the TIC-2B were larger than in air masses forming the TIC-1/2A. Airborne measurements show high acidity near the TIC-2B flight where humidity was low. These results strongly support the hypothesis that acidic coating on IN are at the origin of the formation of TIC-2B.

  19. Alaskan North Slope petroleum systems

    Science.gov (United States)

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

    2003-01-01

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

  20. High-resolution well-log derived dielectric properties of gas-hydrate-bearing sediments, Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope

    Science.gov (United States)

    Sun, Y.; Goldberg, D.; Collett, T.; Hunter, R.

    2011-01-01

    A dielectric logging tool, electromagnetic propagation tool (EPT), was deployed in 2007 in the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well (Mount Elbert Well), North Slope, Alaska. The measured dielectric properties in the Mount Elbert well, combined with density log measurements, result in a vertical high-resolution (cm-scale) estimate of gas hydrate saturation. Two hydrate-bearing sand reservoirs about 20 m thick were identified using the EPT log and exhibited gas-hydrate saturation estimates ranging from 45% to 85%. In hydrate-bearing zones where variation of hole size and oil-based mud invasion are minimal, EPT-based gas hydrate saturation estimates on average agree well with lower vertical resolution estimates from the nuclear magnetic resonance logs; however, saturation and porosity estimates based on EPT logs are not reliable in intervals with substantial variations in borehole diameter and oil-based invasion.EPT log interpretation reveals many thin-bedded layers at various depths, both above and below the thick continuous hydrate occurrences, which range from 30-cm to about 1-m thick. Such thin layers are not indicated in other well logs, or from the visual observation of core, with the exception of the image log recorded by the oil-base microimager. We also observe that EPT dielectric measurements can be used to accurately detect fine-scale changes in lithology and pore fluid properties of hydrate-bearing sediments where variation of hole size is minimal. EPT measurements may thus provide high-resolution in-situ hydrate saturation estimates for comparison and calibration with laboratory analysis. ?? 2010 Elsevier Ltd.

  1. RESOURCE CHARACTERIZATION AND QUANTIFICATION OF NATURAL GAS-HYDRATE AND ASSOCIATED FREE-GAS ACCUMULATIONS IN THE PRUDHOE BAY - KUPARUK RIVER AREA ON THE NORTH SLOPE OF ALASKA

    Energy Technology Data Exchange (ETDEWEB)

    Robert Hunter; Shirish Patil; Robert Casavant; Tim Collett

    2003-06-02

    Interim results are presented from the project designed to characterize, quantify, and determine the commercial feasibility of Alaska North Slope (ANS) gas-hydrate and associated free-gas resources in the Prudhoe Bay Unit (PBU), Kuparuk River Unit (KRU), and Milne Point Unit (MPU) areas. This collaborative research will provide practical input to reservoir and economic models, determine the technical feasibility of gas hydrate production, and influence future exploration and field extension of this potential ANS resource. The large magnitude of unconventional in-place gas (40-100 TCF) and conventional ANS gas commercialization evaluation creates industry-DOE alignment to assess this potential resource. This region uniquely combines known gas hydrate presence and existing production infrastructure. Many technical, economical, environmental, and safety issues require resolution before enabling gas hydrate commercial production. Gas hydrate energy resource potential has been studied for nearly three decades. However, this knowledge has not been applied to practical ANS gas hydrate resource development. ANS gas hydrate and associated free gas reservoirs are being studied to determine reservoir extent, stratigraphy, structure, continuity, quality, variability, and geophysical and petrophysical property distribution. Phase 1 will characterize reservoirs, lead to recoverable reserve and commercial potential estimates, and define procedures for gas hydrate drilling, data acquisition, completion, and production. Phases 2 and 3 will integrate well, core, log, and long-term production test data from additional wells, if justified by results from prior phases. The project could lead to future ANS gas hydrate pilot development. This project will help solve technical and economic issues to enable government and industry to make informed decisions regarding future commercialization of unconventional gas-hydrate resources.

  2. Year-round Source Contributions of Fossil Fuel and Biomass Combustion to Elemental Carbon on the North Slope Alaska Utilizing Radiocarbon Analysis

    Science.gov (United States)

    Barrett, T. E.; Gustafsson, O.; Winiger, P.; Moffett, C.; Back, J.; Sheesley, R. J.

    2015-12-01

    It is well documented that the Arctic has undergone rapid warming at an alarming rate over the past century. Black carbon (BC) affects the radiative balance of the Arctic directly and indirectly through the absorption of incoming solar radiation and by providing a source of cloud and ice condensation nuclei. Among atmospheric aerosols, BC is the most efficient absorber of light in the visible spectrum. The solar absorbing efficiency of BC is amplified when it is internally mixed with sulfates. Furthermore, BC plumes that are fossil fuel dominated have been shown to be approximately 100% more efficient warming agents than biomass burning dominated plumes. The renewal of offshore oil and gas exploration in the Arctic, specifically in the Chukchi Sea, will introduce new BC sources to the region. This study focuses on the quantification of fossil fuel and biomass combustion sources to atmospheric elemental carbon (EC) during a year-long sampling campaign in the North Slope Alaska. Samples were collected at the Department of Energy Atmospheric Radiation Measurement (ARM) climate research facility in Barrow, AK, USA. Particulate matter (PM10) samples collected from July 2012 to June 2013 were analyzed for EC and sulfate concentrations combined with radiocarbon (14C) analysis of the EC fraction. Radiocarbon analysis distinguishes fossil fuel and biomass burning contributions based on large differences in end members between fossil and contemporary carbon. To perform isotope analysis on EC, it must be separated from the organic carbon fraction of the sample. Separation was achieved by trapping evolved CO2 produced during EC combustion in a cryo-trap utilizing liquid nitrogen. Radiocarbon results show an average fossil contribution of 85% to atmospheric EC, with individual samples ranging from 47% to 95%. Source apportionment results will be combined with back trajectory (BT) analysis to assess geographic source region impacts on the EC burden in the western Arctic.

  3. Paleoenvironmental interpretation of an ancient Arctic coastal plain: Integrated paleopedology and palynology from the Late Cretaceous (Maastrichtian) Prince Creek Formation, North Slope, Alaska, USA

    Science.gov (United States)

    McCarthy, P. J.; Flaig, P. P.; Fiorillo, A. R.

    2010-12-01

    The Cretaceous (Early Maastrichtian), dinosaur-bearing Prince Creek Formation, North Slope, Alaska, records high-latitude, alluvial sedimentation and soil formation on a low-lying, coastal plain during a greenhouse phase in Earth history. This study combines outcrop observations, micromorphology, geochemistry, and palynological analyses of paleosols in order to reconstruct local paleoenvironments of weakly developed, high-latitude coastal plain soils. Sediments of the Prince Creek Fm. include quartz- and chert-rich sandstone channels, and floodplains containing organic-rich siltstone and mudstone, carbonaceous shale, coal and ashfall deposits. Vertically stacked horizons of blocky-to-platy, drab-colored mudstone and siltstone with carbonaceous root-traces and mottled aggregates alternating with sandy units indicate that the development of compound and cumulative, weakly-developed soils on floodplains alternated with overbank alluviation and deposition on crevasse splay complexes on floodplains . Soil formation occurred on levees, point bars, crevasse splays and along the margins of floodplain lakes, ponds, and swamps. Soil-forming processes were interrupted by repeated deposition of sediment on top of soil profiles by flooding of nearby channels. Alluviation is evidenced by thin (fern and moss spores, projectates, age-diagnostic Wodehouseia edmontonicola, hinterland bisaccate pollen and pollen from lowland trees, shrubs, and herbs indicate an Early Maastrichtian age for these sediments. Large and small theropods, hadrosaurs, pachycephalosaurs, and ceratopsians, as well as fishes and fossil mammals have been found as well. Paleosols are similar to modern aquic subgroups of Entisols and Inceptisols and, in more distal locations, potential acid sulfate soils. Integration of pedogenic processes and palynology suggests that these high latitude floodplains were influenced by seasonally(?) fluctuating water table levels on a coastal plain governed by a near polar light

  4. Spatial Gradients in Halogen Oxides Across the North Slope of Alaska Indicate That Halogen Activated Airmasses are Spatially Large

    Science.gov (United States)

    Simpson, W. R.; Hoenninger, G. S.; Platt, U.

    2005-12-01

    Reactive halogens are important oxidizers in the polar atmosphere during springtime. They deplete tropospheric ozone, oxidize hydrocarbons, and oxidize gas-phase mercury, causing it to deposit to the snow pack. We want to understand the mechanism by which halides in on snow/ice crystals and/or in aerosol particles are converted to reactive halogen species. This understanding can assist in prediction of mercury deposition and how that deposition depends on environmental variables like sea-ice extent and temperature. This mechanistic knowledge is particularly important in the context of a changing Arctic system. To study halogen activation, we are working in the Studies of the Northern Alaskan Coastal System (SNACS) project and here show results from 2005 including the LEADX experiment. A number of studies have implicated leads (cracks in the sea ice) as a source of halogen activation, but it is unclear if halogens are directly activated on ice surfaces at the lead (e.g. frost flowers) or if the lead is less directly involved. To address the role of leads in halogen activation, we measured bromine monoxide (BrO) using Multiple Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) at Barrow and Atqasuk, Alaska over a four-month period. The locations of these sites, either on the coast near a recurring lead in the case of Barrow, or 100km inland in the case of Atqasuk provides an ability to measure spatial gradients on the 100km length scale. In addition, the Barrow instrument was the first implementation of fully automated two dimensional MAX-DOAS where both elevation and azimuth were scanned. Because the MAX-DOAS method typically detects path-averaged BrO amounts between the instrument and a range of approximately 10km, differences in BrO between viewing azimuths allows us to determine short-length scale BrO gradients. From the 2-D MAX-DOAS observations at Barrow, we find that there are very small if any spatial gradients on the 10km length scale. From the

  5. Response of ice cover on shallow lakes of the North Slope of Alaska to contemporary climate conditions (1950–2011: radar remote sensing and numerical modeling data analysis

    Directory of Open Access Journals (Sweden)

    C. M. Surdu

    2013-07-01

    Full Text Available Air temperature and winter precipitation changes over the last five decades have impacted the timing, duration, and thickness of the ice cover on Arctic lakes as shown by recent studies. In the case of shallow tundra lakes, many of which are less than 3 m deep, warmer climate conditions could result in thinner ice covers and consequently, to a smaller fraction of lakes freezing to their bed in winter. However, these changes have not yet been comprehensively documented. The analysis of a 20 yr time series of ERS-1/2 synthetic aperture radar (SAR data and a numerical lake ice model were employed to determine the response of ice cover (thickness, freezing to the bed, and phenology on shallow lakes of the North Slope of Alaska (NSA to climate conditions over the last six decades. Analysis of available SAR data from 1991–2011, from a sub-region of the NSA near Barrow, shows a reduction in the fraction of lakes that freeze to the bed in late winter. This finding is in good agreement with the decrease in ice thickness simulated with the Canadian Lake Ice Model (CLIMo, a lower fraction of lakes frozen to the bed corresponding to a thinner ice cover. Observed changes of the ice cover show a trend toward increasing floating ice fractions from 1991 to 2011, with the greatest change occurring in April, when the grounded ice fraction declined by 22% (α = 0.01. Model results indicate a trend toward thinner ice covers by 18–22 cm (no-snow and 53% snow depth scenarios, α = 0.01 during the 1991–2011 period and by 21–38 cm (α = 0.001 from 1950–2011. The longer trend analysis (1950–2011 also shows a decrease in the ice cover duration by ∼24 days consequent to later freeze-up dates by 5.9 days (α = 0.1 and earlier break-up dates by 17.7–18.6 days (α = 0.001.

  6. The Iġnik Sikumi Field Experiment, Alaska North Slope: Design, operations, and implications for CO2−CH4 exchange in gas hydrate reservoirs

    Science.gov (United States)

    Boswell, Ray; Schoderbek, David; Collett, Timothy S.; Ohtsuki, Satoshi; White, Mark; Anderson, Brian J.

    2017-01-01

    The Iġnik Sikumi Gas Hydrate Exchange Field Experiment was conducted by ConocoPhillips in partnership with the U.S. Department of Energy, the Japan Oil, Gas and Metals National Corporation, and the U.S. Geological Survey within the Prudhoe Bay Unit on the Alaska North Slope during 2011 and 2012. The primary goals of the program were to (1) determine the feasibility of gas injection into hydrate-bearing sand reservoirs and (2) observe reservoir response upon subsequent flowback in order to assess the potential for CO2 exchange for CH4 in naturally occurring gas hydrate reservoirs. Initial modeling determined that no feasible means of injection of pure CO2 was likely, given the presence of free water in the reservoir. Laboratory and numerical modeling studies indicated that the injection of a mixture of CO2 and N2 offered the best potential for gas injection and exchange. The test featured the following primary operational phases: (1) injection of a gaseous phase mixture of CO2, N2, and chemical tracers; (2) flowback conducted at downhole pressures above the stability threshold for native CH4 hydrate; and (3) an extended (30-days) flowback at pressures near, and then below, the stability threshold of native CH4 hydrate. The test findings indicate that the formation of a range of mixed-gas hydrates resulted in a net exchange of CO2 for CH4 in the reservoir, although the complexity of the subsurface environment renders the nature, extent, and efficiency of the exchange reaction uncertain. The next steps in the evaluation of exchange technology should feature multiple well applications; however, such field test programs will require extensive preparatory experimental and numerical modeling studies and will likely be a secondary priority to further field testing of production through depressurization. Additional insights gained from the field program include the following: (1) gas hydrate destabilization is self-limiting, dispelling any notion of the potential for

  7. Gas hydrate as a proxy for contemporary climate change and shallow heat flow on the US east coast and north slope of Alaska

    Science.gov (United States)

    Phrampus, Benjamin J.

    Methane hydrates, ice-like solids that sequester large quantities of methane in their crystal structure, are stable at moderate pressures and low temperature. The methane contained within these naturally occurring deposits is typically derived from organic matter that is broken down by thermogenic or biogenic activity. Methane hydrate is found world-wide on nearly every continental margin on Earth where the thermodynamic conditions and methane gas permit the formation of hydrate. Hydrate potentially represents the largest reservoir of hydrocarbon on the planet, yet their response to evolving thermodynamic conditions are poorly understood. This dissertation is a summary of several projects that investigate the unique properties of gas hydrate, and the information we can gain from detailed analysis of these natural deposits. Gas hydrate response to contemporary warming is currently poorly understood. Determining if current or past warming trends are having direct effects on the hydrate stability regime is a region of active interest. The observed zone of hydrate stability is deduced from the current distribution of hydrate. Using current geologic and hydrologic conditions, we can compare the model-predicted zone of hydrate stability and directly compare the data with the observed stability regime. Due to the low thermal diffusivity of sediments, heat conduction is slow, thus if the thermodynamic conditions changed recently, the observed zone of stability will not have time to reach equilibrium and will appear anomalous compared with the predicted stability zone. Using this technique, combined with observations of recent changes in ocean temperatures, I identify two regions currently experiencing ocean warming induced hydrate dissociation: The U.S. East Coast (N. Atlantic) and the North Slope of Alaska (Beaufort Sea). These regions are currently experiencing hydrate dissociation due to contemporary climate forcing. Hydrates also offer unique insights into the

  8. Geochemical Monitoring Of The Gas Hydrate Production By CO2/CH4 Exchange In The Ignik Sikumi Gas Hydrate Production Test Well, Alaska North Slope

    Science.gov (United States)

    Lorenson, T. D.; Collett, T. S.; Ignik Sikumi, S.

    2012-12-01

    Hydrocarbon gases, nitrogen, carbon dioxide and water were collected from production streams at the Ignik Sikumi gas hydrate production test well (TD, 791.6 m), drilled on the Alaska North Slope. The well was drilled to test the feasibility of producing methane by carbon dioxide injection that replaces methane in the solid gas hydrate. The Ignik Sikumi well penetrated a stratigraphically-bounded prospect within the Eileen gas hydrate accumulation. Regionally, the Eileen gas hydrate accumulation overlies the more deeply buried Prudhoe Bay, Milne Point, and Kuparuk River oil fields and is restricted to the up-dip portion of a series of nearshore deltaic sandstone reservoirs in the Sagavanirktok Formation. Hydrate-bearing sandstones penetrated by Ignik Sikumi well occur in three primary horizons; an upper zone, ("E" sand, 579.7 - 597.4 m) containing 17.7 meters of gas hydrate-bearing sands, a middle zone ("D" sand, 628.2 - 648.6 m) with 20.4 m of gas hydrate-bearing sands and a lower zone ("C" sand, 678.8 - 710.8 m), containing 32 m of gas hydrate-bearing sands with neutron porosity log-interpreted average gas hydrate saturations of 58, 76 and 81% respectively. A known volume mixture of 77% nitrogen and 23% carbon dioxide was injected into an isolated section of the upper part of the "C" sand to start the test. Production flow-back part of the test occurred in three stages each followed by a period of shut-in: (1) unassisted flowback; (2) pumping above native methane gas hydrate stability conditions; and (3) pumping below the native methane gas hydrate stability conditions. Methane production occurred immediately after commencing unassisted flowback. Methane concentration increased from 0 to 40% while nitrogen and carbon dioxide concentrations decreased to 48 and 12% respectively. Pumping above the hydrate stability phase boundary produced gas with a methane concentration climbing above 80% while the carbon dioxide and nitrogen concentrations fell to 2 and 18

  9. Modeling the Injection of Carbon Dioxide and Nitrogen into a Methane Hydrate Reservoir and the Subsequent Production of Methane Gas on the North Slope of Alaska

    Science.gov (United States)

    Garapati, N.; McGuire, P. C.; Liu, Y.; Anderson, B. J.

    2012-12-01

    HydrateResSim (HRS) is an open-source finite-difference reservoir simulation code capable of simulating the behavior of gas hydrate in porous media. The original version of HRS was developed to simulate pure methane hydrates, and the relationship between equilibrium temperature and pressure is given by a simple, 1-D regression expression. In this work, we have modified HydrateResSim to allow for the formation and dissociation of gas hydrates made from gas mixtures. This modification allows one to model the ConocoPhillips Ignik Sikumi #1 field test performed in early 2012 on the Alaska North Slope. The Ignik Sikumi #1 test is the first field-based demonstration of gas production through the injection of a mixture of carbon dioxide and nitrogen gases into a methane hydrate reservoir and thereby sequestering the greenhouse gas CO2 into hydrate form. The primary change to the HRS software is the added capability of modeling a ternary mixture consisting of CH4 + CO2 + N2 instead of only one hydrate guest molecule (CH4), therefore the new software is called Mix3HydrateResSim. This Mix3HydrateResSim upgrade to the software was accomplished by adding primary variables (for the concentrations of CO2 and N2), governing equations (for the mass balances of CO2 and N2), and phase equilibrium data. The phase equilibrium data in Mix3HydrateResSim is given as an input table obtained using a statistical mechanical method developed in our research group called the cell potential method. An additional phase state describing a two-phase Gas-Hydrate (GsH) system was added to consider the possibility of converting all available free water to form hydrate with injected gas. Using Mix3HydrateResSim, a methane hydrate reservoir with coexisting pure-CH4-hydrate and aqueous phases at 7.0 MPa and 5.5°C was modeled after the conditions of the Ignik Sikumi #1 test: (i) 14-day injection of CO2 and N2 followed by (ii) 30-day production of CH4 (by depressurization of the well). During the

  10. North Slope (Wahluke Slope) expedited response action cleanup plan

    Energy Technology Data Exchange (ETDEWEB)

    1994-02-01

    The purpose of this action is to mitigate any threat to public health and the environment from hazards on the North Slope and meet the expedited response action (ERA) objective of cleanup to a degree requiring no further action. The ERA may be the final remediation of the 100-I-3 Operable Unit. A No Action record of decision (ROD) may be issued after remediation completion. The US Department of Energy (DOE) currently owns or administers approximately 140 mi{sup 2} (about 90,000 acres) of land north and east of the Columbia River (referred to as the North Slope) that is part of the Hanford Site. The North Slope, also commonly known as the Wahluke Slope, was not used for plutonium production or support facilities; it was used for military air defense of the Hanford Site and vicinity. The North Slope contained seven antiaircraft gun emplacements and three Nike-Ajax missile positions. These military positions were vacated in 1960--1961 as the defense requirements at Hanford changed. They were demolished in 1974. Prior to government control in 1943, the North Slope was homesteaded. Since the initiation of this ERA in the summer of 1992, DOE signed the modified Hanford Federal Agreement and Consent Order (Tri-Party Agreement) with the Washington Department of Ecology (Ecology) and the US Environmental Protection Agency (EPA), in which a milestone was set to complete remediation activities and a draft closeout report by October 1994. Remediation activities will make the North Slope area available for future non-DOE uses. Thirty-nine sites have undergone limited characterization to determine if significant environmental hazards exist. This plan documents the results of that characterization and evaluates the potential remediation alternatives.

  11. Air-cushion tankers for Alaskan North Slope oil

    Science.gov (United States)

    Anderson, J. L.

    1973-01-01

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

  12. Environmental Assessment for North Warning System (Alaska)

    Science.gov (United States)

    1986-11-10

    providing coverage farther to the north, and thus cannot fulfill the NWS mission, because of ionospheric interference caused by the aurora borealis (the...fish, including boreal smelt, Arctic cod, cisco, char, whitefish, grayling, fourhorn sculpin, Alaska blackfish, and ninespine stickleback, seasonally

  13. PAH data in tissues of subsistence harvested marine mammal - Determination of PAH baseline values in tissues from subsistence-harvested marine mammals on the North Slope

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Over the past 15 years, high quality marine mammal tissue and fluid samples collected by subsistence hunters in the North Slope region of Alaska have been archived...

  14. Glaciers of North America - Glaciers of Alaska

    Science.gov (United States)

    Molnia, Bruce F.

    2008-01-01

    Glaciers cover about 75,000 km2 of Alaska, about 5 percent of the State. The glaciers are situated on 11 mountain ranges, 1 large island, an island chain, and 1 archipelago and range in elevation from more than 6,000 m to below sea level. Alaska's glaciers extend geographically from the far southeast at lat 55 deg 19'N., long 130 deg 05'W., about 100 kilometers east of Ketchikan, to the far southwest at Kiska Island at lat 52 deg 05'N., long 177 deg 35'E., in the Aleutian Islands, and as far north as lat 69 deg 20'N., long 143 deg 45'W., in the Brooks Range. During the 'Little Ice Age', Alaska's glaciers expanded significantly. The total area and volume of glaciers in Alaska continue to decrease, as they have been doing since the 18th century. Of the 153 1:250,000-scale topographic maps that cover the State of Alaska, 63 sheets show glaciers. Although the number of extant glaciers has never been systematically counted and is thus unknown, the total probably is greater than 100,000. Only about 600 glaciers (about 1 percent) have been officially named by the U.S. Board on Geographic Names (BGN). There are about 60 active and former tidewater glaciers in Alaska. Within the glacierized mountain ranges of southeastern Alaska and western Canada, 205 glaciers (75 percent in Alaska) have a history of surging. In the same region, at least 53 present and 7 former large ice-dammed lakes have produced jokulhlaups (glacier-outburst floods). Ice-capped volcanoes on mainland Alaska and in the Aleutian Islands have a potential for jokulhlaups caused by subglacier volcanic and geothermal activity. Because of the size of the area covered by glaciers and the lack of large-scale maps of the glacierized areas, satellite imagery and other satellite remote-sensing data are the only practical means of monitoring regional changes in the area and volume of Alaska's glaciers in response to short- and long-term changes in the maritime and continental climates of the State. A review of the

  15. DEVELOPMENT OF SHALLOW VISCOUS OIL RESERVES IN NORTH SLOPE

    Energy Technology Data Exchange (ETDEWEB)

    Kishore K. Mohanty

    2004-12-01

    North Slope of Alaska has huge oil deposits in heavy oil reservoirs such as Ugnu, West Sak and Shrader Bluff etc. The viscosity of the last two reservoir oils vary from {approx}30 cp to {approx}3000 cp and the amount in the range of 10-20 billion barrels. High oil viscosity and low formation strength impose problems to high recovery and well productivity. Water-alternate-gas injection processes can be effective for the lower viscosity end of these deposits in West Sak and Shrader Bluff. Several gas streams are available in the North Slope containing NGL and CO{sub 2} (a greenhouse gas). The goal of this research is to develop tools to find optimum solvent, injection schedule and well-architecture for a WAG process in North Slope shallow sand viscous oil reservoirs. Coreflood, quarter 5-spot study, compositional simulation, wettability, relative permeability study and streamline-based simulation were conducted in this project. 1D compositional simulation results agree reasonably well with those of the slim tube experiments. Injection of CO{sub 2}-NGL is preferable over that of PBG-NGL. MME is sensitive to pressure (in the range of 1300-1800 psi) for the injection of PBG-NGL, but not for CO{sub 2}-NGL. Three hydrocarbon phases form in this pressure range. As the mean thickness of the adsorbed organic layer on minerals increases, the oil-water contact angle increases. The adsorbed organic films left behind after extraction of oil by common aromatic solvents used in core studies, such as toluene and decalin, are thinner than those left behind by non-aromatic solvents, such as cyclohexane. The force of adhesion for minerals aged with just the asphaltene fraction is similar to that of the whole oil implying that asphaltenes are responsible for the mixed-wettability in this reservoir. A new relative permeability model for a four-phase, mixed-wet system has been proposed. A streamline module is developed which can be incorporated in an existing finite-difference based

  16. Failure and Redemption of Multifilter Rotating Shadowband Radiometer (MFRSR/Normal Incidence Multifilter Radiometer (NIMFR Cloud Screening: Contrasting Algorithm Performance at Atmospheric Radiation Measurement (ARM North Slope of Alaska (NSA and Southern Great Plains (SGP Sites

    Directory of Open Access Journals (Sweden)

    James Barnard

    2013-09-01

    Full Text Available Well-known cloud-screening algorithms, which are designed to remove cloud-contaminated aerosol optical depths (AOD from Multifilter Rotating Shadowband Radiometer (MFRSR and Normal Incidence Multifilter Radiometer (NIMFR measurements, have exhibited excellent performance at many middle-to-low latitude sites around world. However, they may occasionally fail under challenging observational conditions, such as when the sun is low (near the horizon and when optically thin clouds with small spatial inhomogeneity occur. Such conditions have been observed quite frequently at the high-latitude Atmospheric Radiation Measurement (ARM North Slope of Alaska (NSA sites. A slightly modified cloud-screening version of the standard algorithm is proposed here with a focus on the ARM-supported MFRSR and NIMFR data. The modified version uses approximately the same techniques as the standard algorithm, but it additionally examines the magnitude of the slant-path line of sight transmittance and eliminates points when the observed magnitude is below a specified threshold. Substantial improvement of the multi-year (1999–2012 aerosol product (AOD and its Angstrom exponent is shown for the NSA sites when the modified version is applied. Moreover, this version reproduces the AOD product at the ARM Southern Great Plains (SGP site, which was originally generated by the standard cloud-screening algorithms. The proposed minor modification is easy to implement and its application to existing and future cloud-screening algorithms can be particularly beneficial for challenging observational conditions.

  17. Alaska North-South Deflections (DEFLEC96)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' x 4' surface deflection of the vertical grid for Alaska is the DEFLEC96 model. The computation used about 1.1 million terrestrial and marine gravity data...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-09-01

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

  19. North Slope Decision Support for Water Resource Planning and Management

    Energy Technology Data Exchange (ETDEWEB)

    Schnabel, William; Brumbelow, Kelly

    2013-03-31

    The objective of this project was to enhance the water resource decision-making process with respect to oil and gas exploration/production activities on Alaska’s North Slope. To this end, a web-based software tool was developed to allow stakeholders to assemble, evaluate, and communicate relevant information between and amongst themselves. The software, termed North Slope Decision Support System (NSDSS), is a visually-referenced database that provides a platform for running complex natural system, planning, and optimization models. The NSDSS design was based upon community input garnered during a series of stakeholder workshops, and the end product software is freely available to all stakeholders via the project website. The tool now resides on servers hosted by the UAF Water and Environmental Research Center, and will remain accessible and free-of-charge for all interested stakeholders. The development of the tool fostered new advances in the area of data evaluation and decision support technologies, and the finished product is envisioned to enhance water resource planning activities on Alaska’s North Slope.

  20. Lichenometric dating of slope movements, Nant Ffrancon, North Wales

    Science.gov (United States)

    Winchester, Vanessa; Chaujar, Ravinder K.

    2002-09-01

    Over the last 50 years, frequent debris flows on the oversteepened slopes crossed by the main A5 road in Nant Ffrancon, North Wales, have presented a significant traffic hazard. This study uses two approaches to lichenometry to date earlier debris flows. The first approach provides dating estimates based on size/age correlations of the lichen Rhizocarpon geographicum subspecies prospectans growing in two local churchyards. The correlations supplied a growth rate of 1.47 mm year -1 for the species over a 140-year period, with a delay before colonization of 18 years. Remeasurement of the same lichens after a 4.25-year interval confirmed the growth and colonization rates in the churchyards. The second lichenometric approach, based on population size frequency distributions with size increments dated using the churchyard growth rate, provided controls for the Nant Ffrancon study site, with peaks in Rhizocarpon population size frequency distributions correlating with debris flow dates recorded by Gwynedd Council Highways Department. Circumstantial evidence supporting adoption of the growth rate on the Nant Ffrancon slopes was also supplied by data from archival and meteorological sources. The lichenometric dating estimates suggest that these slopes have a history of periodic debris flows covering at least the last 110 years, with major flows occurring in the 1890s followed by further flows in the early decades of the twentieth century.

  1. Air issues on the north slope of Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Energy resources development on the Central Alaskan arctic coastal zone has introduced large scale fuel burning equipment to the area, resulting in the emission of...

  2. North Slope, Alaska: SOCECON (Socioeconomic Resource Points and Lines)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains data for airports (including airfields, landing strips, helipads, etc., whether they are manned or unmanned), roads, pipelines, and the...

  3. Aerial Surveys of Bowhead Whales, North Slope, Alaska.

    Science.gov (United States)

    1980-02-01

    general area were 15 to 20 belugas ( Delphinapterus leucas ). They were evenly spaced and were proceeding quite steadily in straight, regular lines on...in polynyas within the ice. In early spring, whales from this population move northward from the Bering Sea, passing St Lawrence and Diomede Islands...Harvard Univ. Press Cambridge. MA. Sergeant. D.E. and W. Hoch. 1974. Biology of bowhead Balaena mysticetus and white whale Delphinapterus leucas in

  4. Clouds and snowmelt on the north slope of Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, T.; Stamnes, K.; Bowling, S.A. [Univ. of Alaska, Fairbanks, AK (United States)

    1996-04-01

    Clouds have a large effect on the radiation field. Consequently, possible changes in cloud properties may have a very substantial impact on climate. Of all natural surfaces, seasonal snow cover has the highest surface albedo, which is one of the most important components of the climatic system. Interactions between clouds and seasonal snow cover are expected to have a significant effect on climate and its change at high latitudes. The purpose of this paper is to investigate the sensitivity of the surface cloud-radiative forcing during the period of snowmelt at high latitudes. The primary variables investigated are cloud liquid path (LWP) and droplet equivalent radius (r{sub e}). We will also examine the sensitivity of the surface radiative fluxes to cloud base height and cloud base temperature.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-09-16

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

  6. 76 FR 10388 - Notice of Public Meeting, North Slope Science Initiative-Science Technical Advisory Panel

    Science.gov (United States)

    2011-02-24

    ... decisions. This meeting will include a workshop entitled ``Science, Natural Resources, and Subsistence in... Panel through the Executive Director, North Slope Science Initiative. Each formal meeting will also have... Bureau of Land Management Notice of Public Meeting, North Slope Science Initiative--Science...

  7. Rapid movement of frozen debris-lobes: implications for permafrost degradation and slope instability in the south-central Brooks Range, Alaska

    Science.gov (United States)

    Daanen, R.P.; Grosse, G.; Darrow, M.M.; Hamilton, T.D.; Jones, Benjamin M.

    2012-01-01

    between Interior Alaska and the North Slope.

  8. Alaska Yukon : Waterfowl Breeding Population Survey

    Data.gov (United States)

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

  9. North Slope Moose Surveys Within and Adjacent to the Arctic National Wildlife Refuge, Fall 1988

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Aerial moose surveys were conducted on the north slope from the Sagavanirktok River to the Canning River during 17-19 October 1988. Two aircraft based from Galbraith...

  10. Age, distribution and style of deformation in Alaska north of 60°N: Implications for assembly of Alaska

    Science.gov (United States)

    Moore, Thomas E.; Box, Stephen E.

    2016-11-01

    The structural architecture of Alaska is the product of a complex history of deformation along both the Cordilleran and Arctic margins of North America involving oceanic plates, subduction zones and strike-slip faults and with continental elements of Laurentia, Baltica, and Siberia. We use geological constraints to assign regions of deformation to 14 time intervals and to map their distributions in Alaska. Alaska can be divided into three domains with differing deformational histories. Each domain includes a crustal fragment that originated near Early Paleozoic Baltica. The Northern domain experienced the Early Cretaceous Brookian orogeny, an oceanic arc-continent collision, followed by mid-Cretaceous extension. Early Cretaceous opening of the oceanic Canada Basin rifted the orogen from the Canadian Arctic margin, producing the bent trends of the orogen. The second (Southern) domain consists of Neoproterozoic and younger crust of the amalgamated Peninsular-Wrangellia-Alexander arc terrane and its paired Mesozoic accretionary prism facing the Pacific Ocean basin. The third (Interior) domain, situated between the first two domains and roughly bounded by the Cenozoic dextral Denali and Tintina faults, includes the large continental Yukon Composite and Farewell terranes having different Permian deformational episodes. Although a shared deformation that might mark their juxtaposition by collisional processes is unrecognized, sedimentary linkage between the two terranes and depositional overlap of the boundary with the Northern domain occurred by early Late Cretaceous. Late Late Cretaceous deformation is the first deformation shared by all three domains and correlates temporally with emplacement of the Southern domain against the remainder of Alaska. Early Cenozoic shortening is mild across interior Alaska but is significant in the Brooks Range, and correlates in time with dextral faulting, ridge subduction and counter-clockwise rotation of southern Alaska. Late Cenozoic

  11. Chemical and Microbial Characterization of North Slope Viscous Oils to Assess Viscosity Reduction and Enhanced Recovery

    Energy Technology Data Exchange (ETDEWEB)

    Shirish Patil; Abhijit Dandekar; Mary Beth Leigh

    2008-12-31

    A large proportion of Alaska North Slope (ANS) oil exists in the form of viscous deposits, which cannot be produced entirely using conventional methods. Microbially enhanced oil recovery (MEOR) is a promising approach for improving oil recovery for viscous deposits. MEOR can be achieved using either ex situ approaches such as flooding with microbial biosurfactants or injection of exogenous surfactant-producing microbes into the reservoir, or by in situ approaches such as biostimulation of indigenous surfactant-producing microbes in the oil. Experimental work was performed to analyze the potential application of MEOR to the ANS oil fields through both ex situ and in situ approaches. A microbial formulation containing a known biosurfactant-producing strain of Bacillus licheniformis was developed in order to simulate MEOR. Coreflooding experiments were performed to simulate MEOR and quantify the incremental oil recovery. Properties like viscosity, density, and chemical composition of oil were monitored to propose a mechanism for oil recovery. The microbial formulation significantly increased incremental oil recovery, and molecular biological analyses indicated that the strain survived during the shut-in period. The indigenous microflora of ANS heavy oils was investigated to characterize the microbial communities and test for surfactant producers that are potentially useful for biostimulation. Bacteria that reduce the surface tension of aqueous media were isolated from one of the five ANS oils (Milne Point) and from rock oiled by the Exxon Valdez oil spill (EVOS), and may prove valuable for ex situ MEOR strategies. The total bacterial community composition of the six different oils was evaluated using molecular genetic tools, which revealed that each oil tested possessed a unique fingerprint indicating a diverse bacterial community and varied assemblages. Collectively we have demonstrated that there is potential for in situ and ex situ MEOR of ANS oils. Future work

  12. North to Alaska: The Geostrategic Importance of the Last Frontier

    Science.gov (United States)

    2012-06-01

    Strategic Possibilities of Alaska: 1934-1935. Captain Arthur W. Vanaman, Captain Muir S. Fairchild, Lieutenant Hoyt S. Vandenberg, and Lieutenant Laurence ...Rare Earth Minerals: over 150 occurrences67 Alaska contains in-demand rare earth elements ( REE ), which are valuable strategic minerals. REEs are...webpubs/dggs/sr/text/sr065.PDF (accessed 24 April 2012). 67 Sullivan, “Testimony,” 2. 58 vehicles).”68 REEs transform crude oil into gasoline

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

    Science.gov (United States)

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

    2003-01-01

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

  14. Sedimentology and sequence stratigraphy of the Cretaceous Nanushuk, Seabee, and Tuluvak formations exposed on Umiat Mountain, north-central Alaska

    Science.gov (United States)

    Houseknecht, David W.; Schenk, Christopher J.

    2005-01-01

    Upper Cretaceous strata of the upper part of the Nanushuk Formation, the Seabee Formation, and the lower part of the Tuluvak Formation are exposed along the Colville River on the east flank of Umiat Mountain in north-central Alaska. The Ninuluk sandstone, which is the uppermost unit of the Nanushuk Formation, displays a vertical succession of facies indicative of deposition in an upward-deepening estuarine through shoreface setting. A marine-flooding surface lies between the Ninuluk sandstone and organic-rich shale of the basal part of the Seabee Formation. The Ninuluk sandstone and the lower part of the Seabee Formation are interpreted as components of a transgressive-systems tract. The lowest, well-exposed strata in the Seabee Formation are a succession of shoreface sandstone beds in the middle of the formation. Integration of outcrop information and the Umiat No. 11 well log suggests that this sandstone succession rests on a sequence boundary and is capped by a marine-flooding surface. The sandstone succession is interpreted as a lowstand-systems tract. The upper part of the Seabee Formation includes a thick interval of organic-rich shale deposited in a dysaerobic offshore environment, and the gradational Seabee-Tuluvak contact is a coarsening-upward shale-to-sandstone succession deposited in a prodelta/delta-front environment. The observation that the upper part of the Seabee Formation correlates with seismic clinoforms suggests that dysaerobic conditions extended well up onto the prodelta slope during intervals of transgression and highstand. Correlation of the Umiat Mountain outcrop section with well logs and seismic data suggests that sequence boundaries and lowstand shoreface deposits may be common in the Seabee Formation and that wave action may have been important in transporting sand to the paleoshelf margin. These conclusions may contribute to an enhanced understanding of sand distribution in prospective lowstand turbidite deposits in the subsurface of

  15. Depositional Characteristics of Deltas and Their Relationship with Hydrocarbon Accumulation in the North Slope, Biyang Depression

    Institute of Scientific and Technical Information of China (English)

    ZHONG Jun-yi; ZHENG Jun-mao; WANG Guo-peng; LI Gui-lin; YU Gong-ming

    2006-01-01

    Tectonic movements in the North Slope of Biyang Depression are comparatively mild and stable, thus generating two categories of deltas. Elementary reasons for the coexistence of deltas are the existence of the palaeodrainage pattern and the effect of palaeotopography. The sedimentary facies is the most elementary factor controlling the physical property of reservoirs. The layout and spatial combination model of the sand body and faults are the major influential factors on the occurrence of hydrocarbons. Comparative study on Houzhang and Yanglou Braided Deltas as well as Zhangchang and Gucheng Meandering Deltas suggests that the hydrocarbons distribute primarily in the mouth bar subfacies and secondarily in the distal bar subfacies of the braided delta, while the oil-water and aqueous layers are mainly found in the subaquatic distributary channel. Although the sand body of the meandering delta has excellent stratification and high porosity, the thickness is far less than that of the braided delta. Therefore, the yield of hydrocarbon is relatively low. The mudstone of the delta front subfacies is a kind of source rock with a high content of organic matter. The conducting system for oil/gas migration in the North Slope is a composite one comprising faults and sandstone reservoirs. A large amount of oil/gas from the deep depression first migrated towards the slope along the sand body which stretches and connects with the source rocks, and then redistributed along the faults in the slope. After the movement reached a standstill, the faults formed the occlusion in the up-dip direction of the sand body, generating a great quantity of fault block hydrocarbon reservoirs in the North Slope.

  16. Alaska oil and gas: Energy wealth or vanishing opportunity

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, C.P.; Doughty, T.C.; Faulder, D.D.; Harrison, W.E.; Irving, J.S.; Jamison, H.C.; White, G.J.

    1991-01-01

    The purpose of the study was to systematically identify and review (a) the known and undiscovered reserves and resources of arctic Alaska, (b) the economic factors controlling development, (c) the risks and environmental considerations involved in development, and (d) the impacts of a temporary shutdown of the Alaska North Slope Oil Delivery System (ANSODS). 119 refs., 45 figs., 41 tabs.

  17. Analysis on Variations of the Temperature and Precipitation in North Slope Area of the Western Tianshan in Recent 50 Years

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective]The research aimed to analyze variation characteristics of the temperature and precipitation in north slope area of the Western Tianshan in recent 50 years.[Method] According to temperature and rainfall data from 1961 to 2010 at three meteorological stations in north slope area of the Western Tianshan,climate change in the zone in recent 50 years was analyzed by using linear trend analysis method and 5-year sliding average method.[Result] The temperature in north slope area of the Western Tiansha...

  18. 40 CFR 81.302 - Alaska.

    Science.gov (United States)

    2010-07-01

    ... AREAS FOR AIR QUALITY PLANNING PURPOSES Section 107 Attainment Status Designations § 81.302 Alaska... river. Also, Township 1 South, Range 1 East, Sections 7, 8, and 18 and the portion of Section 19 north... urban area designated Nonattainment Kobuk Election District Nome Election District North Slope...

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

    Science.gov (United States)

    Hobson, Anne Carrie Hickey

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

  20. Participatory Selection of Tree Species for Agroforestry on Sloping Land in North Korea

    Directory of Open Access Journals (Sweden)

    Jun He

    2015-11-01

    Full Text Available The action research project reported in this article used a participatory approach to select trees for sloping-land agroforestry as a key strategy for forest ecosystem restoration and local livelihood development. It was the first such project in the Democratic People’s Republic of Korea (North Korea to use a participatory approach, empowering local user groups to develop their preferences for agroforestry species. Local knowledge of the multiple functions of agroforestry species ensured that the tree selection criteria included the value of timber, fruit, fodder, oil, medicines, fuelwood, and erosion control. Involving 67 farmers from 3 counties, this participatory selection process resulted in Prunus armeniaca, Castanea crenata, and Ziziphus jujuba being selected as the top 3 species for the development of sloping-land agroforestry in North Hwanghae Province. These trees embody what the region’s farmers value most: erosion control, production of fruit, and economic value. The participatory approach in agroforestry could help to meet both local needs for food security and the national objective of environmental conservation and has great potential for wide adaptation in North Korea and beyond.

  1. Holocene Pacific North American plate interaction in southern Alaska: Implications for the Yakataga seismic gap

    Science.gov (United States)

    Lahr, John C.; Plafker, George

    1980-10-01

    The St. Elias, Alaska, earthquake (magnitude 7.1 Ms) on February 28, 1979, occurred along the complex Pacific North American plate boundary between Yakutat Bay and Prince William Sound, rupturing only a fraction of the seismic gap identified in that region. To aid in evaluating the potential for, and likely site of, a future earthquake occurring in the remainder of the gap, we have formulated a kinematic model of neotectonic deformation in southern Alaska from available geologic and seismic data. In this model the part of the North American plate bordering on the Gulf of Alaska is divided into three subblocks, which are partially coupled to the Pacific plate. On the basis of the model, the gap-filling rupture or ruptures would most likely be along the north-dipping thrust faults of the Pamplona zone between Icy Bay and the eastern end of the Aleutian Trench. If the accumulated strain of 3.8 m postulated for this region were released suddenly in one event involving the remainder of the gap, the result would be an earthquake as large as magnitude 8.

  2. Holocene Pacific - North American plate interaction in southern Alaska: implications for the Yakataga seismic gap.

    Science.gov (United States)

    Lahr, J.C.; Plafker, G.

    1980-01-01

    The St. Elias, Alaska, earthquake (magnitude 7.1 MS) on February 28, 1979, occurred along the complex Pacific-North American plate boundary between Yakutat Bay and Prince William Sound, rupturing only a fraction of the seismic gap identified in that region. To aid in evaluating the potential for, and likely site of, a future earthquake occurring in the remainder of the gap, we have formulated a kinematic model of neotectonic deformation in southern Alaska from available geologic and seismic data. In this model the part of the North American plate bordering on the Gulf of Alaska is divided into three subblocks, which are partially coupled to the Pacific plate. On the basis of the model, the gap-filling rupture or ruptures would most likely be along the north-dipping thrust faults of the Pamplona zone between Icy Bay and the eastern end of the Aleutian Trench. If the accumulated strain of 3.8 m postulated for this region were released suddenly in one event involving the remainder of the gap, the result would be an earthquake as large as magnitude 8. -Authors

  3. North Alaska petroleum analysis: the regional map compilation

    Science.gov (United States)

    Saltus, Richard W.; Bird, Kenneth J.

    2003-01-01

    The U.S. Geological Survey initiated an effort to model north Alaskan petroleum systems. The geographic and geologic basis for modeling systems is provided by a set of regional digital maps that allow evaluation of the widest possible extent of each system. Accordingly, we laid out a rectangular map grid 1300 km (800 miles) east-west and 600 km (375 miles) north-south. The resulting map area extends from the Yukon Territory of Canada on the east to the Russian-U.S. Chukchi Sea on the west and from the Brooks Range on the south to the Canada basin-Chukchi borderland on the north. Within this map region, we combined disparate types of publicly available data to produce structure contour maps. Data types range from seismic-based mapping as in the National Petroleum Reserve to well penetrations in areas of little or no seismic data where extrapolation was required. With these types of data, we produced structure contour maps on three horizons: top of pre-Mississippian (basement), top of Triassic (Ellesmerian sequence), and top of Neocomian (Beaufortian sequence). These horizons, when combined with present-day topography and bathymetry, provide the bounding structural/stratigraphic surfaces of the north Alaskan petroleum province that mark major defining moments of the region's geologic history and allow regional portrayal of preserved sediment accumulations.

  4. Preliminary discussion on gas hydrate reservoir system of Shenhu Area, North Slope of South China Sea

    Energy Technology Data Exchange (ETDEWEB)

    Wu, N.; Yang, S.; Liang, J.; Wang, H.; Fu, S. [Guangzhou Marine Geological Survey, Guangzhou (China); Zhang, H. [China Geological Survey, Beijing (China); Su, X. [China Univ. of Geosciences, Beijing (China)

    2008-07-01

    Gas hydrate is a type of ice-like solid substance formed by the combination of certain low-molecular-weight gases such as methane, ethane, and carbon dioxide with water. Gas hydrate primarily occurs naturally in sediments beneath the permafrost and the sediments of the continental slope with the water depth greater than 300 m. Marine gas hydrate geological systems are important because they may be sufficiently concentrated in certain locations to be an economically viable fossil fuel resource. However, gas hydrates can cause geo-hazards through large-scale slope destabilization and can release methane, a potential greenhouse gas, into the environment. This paper discussed the hydrate drilling results from a geological and geophysical investigation of the gas hydrate reservoir system of the Shenhu Area, located in the north slope of South China Sea. The paper identified the basic formation conditions, and discussed the pore-water geochemical features of shallow sediments and their inflected gas sources, gas hydrate distribution and seismic characteristics. It was concluded that the gas hydrate was heterogeneously distributed in space, and mainly distributed in certain ranges above the bottom of the gas hydrate stability zone. It was also concluded that methane gas that formed hydrate was likely from in-situ micro-biogenic methane. Last, it was found that distributed and in-situ micro-biogenic methane resulted in low methane flux, and formed the distributed pattern of gas hydrate system with the features of differential distribution and saturation. 34 refs., 2 tabs., 3 figs.

  5. Landfall tropical cyclone rainstorms on the north slope of the Dabie Mountains

    Science.gov (United States)

    Huang, Z. Y.; Wang, J. Y.; Lee, C.

    2016-08-01

    The formation and development mechanism of landfall cyclone rainstorms that occur on the north slope of the Dabie Mountains were investigated by the determination of typical occurrences. Interaction between the tropical cyclone and the westerly trough was characterized by the favorable circulation backgrounds of landfall tropical cyclone rainstorms on the north slope of the Dabie Mountains. A conveyor belt was created between the easterly jet flow of the tropical cyclone and the subtropical high pressure of the western equatorial Pacific Ocean and the southerly jet flow of the westerly trough front, creating a huge amount of energy and vapor from the landfall tropical cyclone in the rainstorm area and destabilizing the stratification. These conditions were advantageous to the frontogenesis of a warm front and the development of Mesoscale convective systems (MCS) in the westerly cold air that met the inverted trough located at the northern portion of the tropical cyclone. The existence and development of the mesoscale front area in the ground provide a trigger mechanism for the rainstorm. The MCS occurred and developed in the equivalent potential temperature theta se (θse) frontal zone, which is located between the low pressure area of the typhoon and the cold air, which is located at the rear of the westerly trough. The terrain block slowed or stopped the motion of the low pressure system formed by the landfall tropical cyclone, which was conducive to the enhancement of the rainstorm.

  6. NOAA marine environmental buoy data from the National Data Buoy Center in the Gulf of Alaska, Gulf of Mexico, Bering Sea, North Atlantic Ocean, North Pacific Ocean, Coastal Waters of SE Alaska, Coastal Waters of Western U.S., Great Lakes, North American Coastline-North, and North American Coastline-South from 2002-10-01 to 2002-10-31 (NCEI Accession 0000400)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pressure, temperature, and other data were collected from fixed platforms in the Gulf of Alaska, Gulf of Mexico, Bering Sea, North Atlantic Ocean, North Pacific...

  7. Massive submarine slope failures during the 1964 earthquake in Port Valdez, Alaska

    Science.gov (United States)

    Lee, H. J.; Ryan, H. F.; Suleimani, E.; Haeussler, P. A.; Kayen, R. E.; Hampton, M. A.

    2006-12-01

    The M9.2 Alaska earthquake of 1964 caused major damage to the port facilities and town of Valdez, resulting in a total of 32 deaths. Most of the damage and deaths in Valdez were caused by submarine-landslide generated tsunamis that occurred immediately after the earthquake. Some post-earthquake investigations were conducted in the 1960's. Dramatic changes in bathymetry were observed, including several hundred meters of deepening below the head of Port Valdez fjord, and these were attributed to submarine landsliding. Recent multibeam surveys of Port Valdez provide much more information about the morphology of landslide deposits. Also, we collected high-resolution (chirp) surveys over apparent landslide debris to evaluate the chronology and three-dimensional character of the deposits, and we performed quantitative evaluations of pre- and post-earthquake bathymetric data. Landslide morphologies include several forms. In the western part of the fjord, there is a field of large blocks (up to 40-m high) on the fjord floor near the location of the greatest tsunami-wave runup estimated for the 1964 earthquake (~50 m). The runup direction for the waves (northeast) is consistent with the failure of these blocks being the trigger. Surrounding the fields of blocks are lobes from two debris flows that likely occurred at the same time as the block slides. Both debris flows and block slides appear to have resulted from the failure of a large moraine front, formed by Shoup Glacier on the northwest side of Port Valdez. At the fjord head, near the location of the badly damaged old town of Valdez, is an intricate series of gullies, channels, and talus, although these features display little evidence for the large-scale mass movement that occurred. However, near the center of the fjord is the front of a large debris lobe that flowed from the east end of the fjord half-way down the fjord and stopped. This huge deposit represents material that failed at the fjord head, mobilized into a

  8. Massive submarine slope failures during the 1964 earthquake in Port Valdez, Alaska

    Science.gov (United States)

    Lee, H.; Ryan, H.F.; Suleimani, E.; Kayen, R.E.; Hampton, M.A.

    2006-01-01

    The M9.2 Alaska earthquake of 1964caused major damage to the port facilities and town of Valdez, resulting in a total of 32 deaths. Most of the damage and deaths in Valdez were caused by submarine-landslide generated tsunamis that occurred immediately after the earthquake. Some post-earthquake investigations were conducted in the 1960's. Dramatic changes in bathymetry were observed, including several hundred meters of deepening below the head of Port Valdezfjord, and these were attributed to submarine landsliding. Recent multibeam surveys of Port Valdez provide much more information about the morphology of landslide deposits. Also, we collected high-resolution (chirp) surveys over apparent landslide debris to evaluate the chronology and three-dimensional character of the deposits, and we performed quantitative evaluations of pre- and post-earthquake bathymetric data. Landslide morphologies include several forms. In the western part of the fjord, there is a field of large blocks (up to 40-m high) on the fjord floor near the location of the greatest tsunami-wave runup estimated for the 1964 earthquake (~50 m). The runup direction for the waves (northeast) is consistent with the failure of these blocks being the trigger. Surrounding the fields of blocks are lobes from two debris flows that likely occurred at the same time as the block slides. Both debris flows and block slides appear to have resulted from the failure of a large moraine front, formed by Shoup Glacier on the northwest side of Port Valdez. At the fjord head, near the location of the badly damaged old town of Valdez, is an intricate series of gullies, channels, and talus, although these features display little evidence for the large-scale mass movement that occurred. However, near the center of the fjord is the front of a large debris lobe that flowed from the east end of the fjord half-way down the fjord and stopped. This huge deposit represents material that failed at the fjord head

  9. Time-slice maps showing age, distribution, and style of deformation in Alaska north of 60° N.

    Science.gov (United States)

    Moore, Thomas E.; Box, Stephen E.

    2016-08-29

    The structural architecture of Alaska is the product of a complex history of tectonism that occurred along the Cordilleran and Arctic margins of North America through interactions with ancient and modern ocean plates and with continental elements derived from Laurentia, Siberia, and Baltica. To unravel the tectonic history of Alaska, we constructed maps showing the age, distribution, structural style, and kinematics of contractional and penetrative extensional deformation in Alaska north of latitude 60° N. at a scale of 1:5,000,000. These maps use the Geologic Map of the Arctic (Harrison and others, 2011) as a base map and follow the guidelines in the Tectonic Map of the Arctic project (Petrov and others, 2013) for construction, including use of the International Commission on Stratigraphy time scale (Cohen and others, 2013) divided into 20 time intervals. We find evidence for deformation in 14 of the 20 time intervals and present maps showing the known or probable extent of deformation for each time interval. Maps and descriptions of deformational style, age constraints, kinematics, and information sources for each deformational episode are discussed in the text and are reported in tabular form. This report also contains maps showing the lithologies and structural geology of Alaska, a terrane map, and the distribution of tectonically important units including post-tectonic sedimentary basins, accretionary complexes, ophiolites, metamorphic rocks.These new maps show that most deformational belts in Alaska are relatively young features, having developed during the late Mesozoic and Cenozoic. The oldest episode of deformation recognized anywhere in Alaska is found in the basement of the Farewell terrane (~1.75 Ga). Paleozoic and early Mesozoic deformational events, including Devonian deformation in the Arctic Alaska terrane, Pennsylvanian deformation in the Alexander terrane, Permian deformation in the Yukon Composite (Klondike orogeny) and Farewell terranes (Browns

  10. Aliphatic and aromatic hydrocarbon, organochlorine pesticide, and trace element concentrations in six fox livers from the Prudhoe Bay Oilfield, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This study was a portion of a multi-year assessment of contaminant concentrations from a variety of biotic and abiotic samples on the North Slope of Alaska. The...

  11. Geochemical and faunal investigation of shelf/slope environment of north-central Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Healy-Williams, N.; Trainor, D.M.; Williams, D.F.; Jenkins, P. (Univ. of South Carolina, Columbia (United States)); Gary, A. (Unocal, Brea, CA (United States))

    1991-03-01

    The shelf/slope environment of the northern Gulf of Mexico offers a complex pattern of marine and terrestrial derived sediments. The authors have performed geochemical and faunal investigations on approximately 80 box cores from 30 to 1,300 m water depth from the north-central Gulf of Mexico. The geochemical results relate the modern and late Holocene distribution of marine and terrestrial organic carbon to the present day depositional systems of this actively prograding system. Total organic carbon (%TOC) analyses of the surface sediment are used to characterize the distribution of TOC on the Louisiana shelf and slope as a function of distance from the Mississippi delta. Stable carbon isotopic analyses ({sup 13}C/{sup 12}C) of the TOC are used to distinguish marine from terrestrial organic carbon. Higher amounts of terrestrial organic carbon are associated with the western edge of the Mississippi delta. Marine organic carbon increases seaward of the deltaic system. The percentage of fine-grained (< 63 microns) calcium carbonate also increases seaward of the Mississippi delta as well as with lateral distance along the shelf-slope. Percent CaCO{sub 3} and {delta}{sup 13}C of the fine-grained carbonate determinations have been performed in Plio-Pleistocene cores and exploration wells from this region. The authors use this data to examine how the modern/late Holocene patterns of these variables have changed as a function of continental margin evolution. They have also analyzed the benthic foraminiferal distributions in terms of the sedimentary nature of the box cores. They note increased abundances in certain species in relation to deltaic vs nondeltaic environments along with some species altering their depth ranges between the two environments.

  12. Numerical Study of Tsunami Generated by Multiple Submarine Slope Failures in Resurrection Bay, Alaska, during the M W 9.2 1964 Earthquake

    Science.gov (United States)

    Suleimani, Elena; Hansen, Roger; Haeussler, Peter J.

    2009-02-01

    We use a viscous slide model of J iang and L eB lond (1994) coupled with nonlinear shallow water equations to study tsunami waves in Resurrection Bay, in south-central Alaska. The town of Seward, located at the head of Resurrection Bay, was hit hard by both tectonic and local landslide-generated tsunami waves during the M W 9.2 1964 earthquake with an epicenter located about 150 km northeast of Seward. Recent studies have estimated the total volume of underwater slide material that moved in Resurrection Bay during the earthquake to be about 211 million m3. Resurrection Bay is a glacial fjord with large tidal ranges and sediments accumulating on steep underwater slopes at a high rate. Also, it is located in a seismically active region above the Aleutian megathrust. All these factors make the town vulnerable to locally generated waves produced by underwater slope failures. Therefore it is crucial to assess the tsunami hazard related to local landslide-generated tsunamis in Resurrection Bay in order to conduct comprehensive tsunami inundation mapping at Seward. We use numerical modeling to recreate the landslides and tsunami waves of the 1964 earthquake to test the hypothesis that the local tsunami in Resurrection Bay has been produced by a number of different slope failures. We find that numerical results are in good agreement with the observational data, and the model could be employed to evaluate landslide tsunami hazard in Alaska fjords for the purposes of tsunami hazard mitigation.

  13. Sedimentology and Sequence Stratigraphy of the Lower Cretaceous Fortress Mountain and Torok Formations Exposed Along the Siksikpuk River, North-Central Alaska

    Science.gov (United States)

    Houseknecht, David W.; Schenk, Christopher J.; Wartes, Marwan A.

    2007-01-01

    An exposure of the Lower Cretaceous Fortress Mountain and Torok Formations along the Siksikpuk River in north-central Alaska provides a rare opportunity to observe the stratigraphic contact between these two formations and to interpret the depositional facies and sequence stratigraphy of the exposed strata. The Fortress Mountain Formation at the base of the measured section includes braided-fluvial and coastal-plain facies deposited in a lowstand-systems tract, and an overlying succession of mostly shallow marine facies deposited in the basal part of a transgressive-systems tract. The overlying Torok Formation includes a thick, upward-deepening succession of marine-shelf to marine-slope facies deposited in the upper part of the transgressive-systems tract. The upper part of the section includes marine-slope and incised-slope-channel turbidite deposits of the Torok Formation, interpreted as a highstand-systems tract. Consideration of the balance between accommodation and sediment flux inferred from the sequence-stratigraphic analysis suggests that both tectonics and eustasy may have influenced deposition of the lowstand-systems and transgressive-systems tracts. In contrast, the highstand-systems tract may have been primarily influenced by progradation of a regional sediment-dispersal system and by subsidence induced by sediment loading.

  14. Evaluation of the biodegradation of Alaska North Slope oil in microcosms using the biodegradation model BIOB

    Directory of Open Access Journals (Sweden)

    Jagadish eTorlapati

    2014-05-01

    Full Text Available We present the details of a numerical model, BIOB that is capable of simulating the biodegradation of oil entrapped in the sediment. The model uses Monod kinetics to simulate the growth of bacteria in the presence of nutrients and the subsequent consumption of hydrocarbons. The model was used to simulate experimental results of Exxon Valdez oil biodegradation in laboratory columns (Venosa et al. (2010. In that study, samples were collected from three different islands: Eleanor Island (EL107, Knight Island (KN114A, and Smith Island (SM006B, and placed in laboratory microcosms for a duration of 168 days to investigate oil bioremediation through natural attenuation and nutrient amendment. The kinetic parameters of the BIOB model were estimated by fitting to the experimental data using a parameter estimation tool based on Genetic Algorithms (GA. The parameter values of EL107 and KN114A were similar whereas those of SM006B were different from the two other sites; in particular biomass growth at SM006B was four times slower than at the other two islands. Grain size analysis from each site revealed that the specific surface area per unit mass of sediment was considerably lower at SM006B, which suggest that the surface area of sediments is a key control parameter for microbial growth in sediments. Comparison of the BIOB results with exponential decay curves fitted to the data indicated that BIOB provided better fit for KN114A and SM006B in nutrient amended treatments, and for EL107 and KN114A in natural attenuation. In particular, BIOB was able to capture the initial slow biodegradation due to the lag phase in microbial growth. Sensitivity analyses revealed that oil biodegradation at all three locations were sensitive to nutrient concentration whereas SM006B was sensitive to initial biomass concentration due to its slow growth rate. Analyses were also performed to compare the half-lives of individual compounds with the decay rate of the overall PAH.

  15. 2009 Aero-Metric Inc. Topographic LiDAR: North Slope Coastal Alaska

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This delivery contains point cloud data in LAS 1.2 format, with Absolute GPS Timestamps. No classification has been completed on these data. The nominal point...

  16. Sedimentological evolution of Mississippian Kekiktuk Formation, Sagavanirktok Delta area, North Slope, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Melvin, J.

    1985-04-01

    The reservoir interval in the Endicott field, located under the delta of the Sagavanirktok River east of Prudhoe Bay, is the Mississippian Kekiktuk formation. The lower-most interval (zone 1) rests directly on metamorphic basement and comprises interbedded coal, mudstones, siltstones, and fine-grained sandstones. These rocks were deposited in a very low-lying swamp plain containing local lakes and sluggish, highly sinuous streams. Zone 1 is overlain sharply by zone 2, which comprises medium to coarse-grained, multistory sandstone that was deposited within an unconstrained braided river system. The braid plain contained both ephemeral and permanent lakes, and periodic gravity flows deposited coarser sediment into the latter. That sequence passes gradationally upward into zone 3, which is composed of coarse-, medium-, and fine-grained sandstones, as well as siltstones, mudstones, and coals. The lower part of zone 3 is dominated by upward-fining sandstone sequences, interpreted as channel bars deposited within a moderately sinuous fluvial system. They pass gradationally upward into other, distinct upward-fining sequences, which differ in having higher proportions of siltstone, mudstone, and coal. Those rocks were deposited in a more highly sinuous (meandering) fluvial environment. The rocks grade upward into shallow marine sediments of the Kayak/Itkilyariak formations. The vertical sequence within the Kekiktuk in this area permits an interpretation of the structural history of the basin during Kekiktuk time.

  17. Assessment of the Phototoxicity of Weathered Alaska North Slope Crude Oil to Juvenile Pink Salmon

    Science.gov (United States)

    Petroleum products are known to have greater toxicity to the translucent embryos and larvae of aquatic organisms in the presence of ultraviolet radiation (UV) compared to toxicity determined in tests performed under standard laboratory lighting with minimal UV. This study assesse...

  18. Preliminary microfacies analysis and cyclicity of the Wahoo Limestone, Lisburne Field, North Slope, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, S.K.; Watts, K.F.

    1995-05-01

    A well from the Lisburne field near Prudhoe Bay was examined in core, thin section, and on well logs for comparison with Wahoo Limestone in the Arctic National Wildlife Refuge (ANWR). Carbonate cycles (parasequences) are well developed in both areas but the greater abundance of terrigenous sediment and associated carbonate facies indicate that the study well is located in a more landward position on the Wahoo carbonate ramp, closer to a source of terrigenous sediment. This report presents the preliminary results of microfacies analyses that have been conducted on 424 of a total 1,115 thin sections from the study well. The stratigraphic nomenclature extended from ANWR (the type locality of the Wahoo Limestone) is different that the terminology previously used for the subsurface Lisburne Group near Prudhoe Bay. We distinguish informal lower and upper members within the Mississippian to Pennsylvanian Wahoo Limestone which overlies the Mississippian Alapah Limestone. Our upper Alapah corresponds to the middle Alapah of previous workers. Our lower Wahoo Limestone member corresponds to the upper Alapah of previous workers. Our upper Wahoo Limestone member corresponds to the previous Wahoo Limestone and is the major hydrocarbon reservoir at the Lisburne field, which is characterized by well-developed carbonate cycles (parasequences).

  19. Arctic Shrub Growth Response to Climate Variation and Infrastructure Development on the North Slope of Alaska

    Science.gov (United States)

    Ackerman, D.; Finlay, J. C.; Griffin, D.

    2015-12-01

    Woody shrub growth in the arctic tundra is increasing on a circumpolar scale. Shrub expansion alters land-atmosphere carbon fluxes, nutrient cycling, and habitat structure. Despite these ecosystem effects, the drivers of shrub expansion have not been precisely established at the landscape scale. This project examined two proposed anthropogenic drivers: global climate change and local infrastructure development, a press disturbance that generates high levels of dust deposition. Effects of global change were studied using dendrochronology to establish a relationship between climate and annual growth in Betula and Salix shrubs growing in the Alaskan low Arctic. To understand the spatial heterogeneity of shrub expansion, this analysis was replicated in shrub populations across levels of landscape properties including soil moisture and substrate age. Effects of dust deposition on normalized difference vegetation index (NDVI) and photosynthetic rate were measured on transects up to 625 meters from the Dalton Highway. Dust deposition rates decreased exponentially with distance from road, matching previous models of road dust deposition. NDVI tracked deposition rates closely, but photosynthetic rates were not strongly affected by deposition. These results suggest that dust deposition may locally bias remote sensing measurements such as NDVI, without altering internal physiological processes such as photosynthesis in arctic shrubs. Distinguishing between the effects of landscape properties, climate, and disturbance will improve our predictions of the biogeochemical feedbacks of arctic shrub expansion, with potential application in climate change modeling.

  20. 78 FR 38358 - Call for Nominations: North Slope Science Initiative, Science Technical Advisory Panel, Alaska

    Science.gov (United States)

    2013-06-26

    ..., petroleum engineering, civil engineering, geology, sociology, cultural anthropology, economics, ornithology... will consist of individuals having a minimum of 5 years of work experience in the Arctic in their...

  1. Soil mixing and transport on steep pastoral slopes: North Island, New Zealand

    Science.gov (United States)

    Norton, Kevin; Hickey, Gareth; Bennett, John; Popelka-Filcoff, Rachel

    2013-04-01

    Convex hillslopes are typically the domain of high soil production rates and thin soils, related to the increasing mass flux in the downslope direction. Concave hillslopes tend to be depositional, with lower soil production rates and thicker soils. Hillslopes in pastoral settings have often been stripped of trees and shrubs in order to support grazing animals. The loss of vegetation can lead to extreme erosion of the existing soil stores. We have sampled 8 soil pits along two transects on a convex/concave hillslope in a typical pastoral New Zealand setting. While soil depths measured here support the idea of steady state soils with a negative depth/curvature relationship, the immobile element concentrations suggest more complex movement. The initial results suggest significant downslope transport of both dissolved and solid mass as well as mass addition to the soil. In a purely surface erosion-driven system, immobile element (Zr, Ti, Y, etc.) concentrations should increase towards the surface as other elements are preferentially removed. Likewise, soil density should increase with depth in a soil pit. None of the traditional immobile elements correlate well with soil depth. This suggests that these soils have undergone extensive mixing. High soil densities in the lowest convex soil pits further suggest that either significant soil erosion has occurred at the lower pits, or that mass is being advected down slope. The latter would also account for the dilution of zirconium. An alternative hypothesis for explaining the low concentrations of immobile elements in the soils is the addition of mass. This is a reasonable scenario in the lower North Island of New Zealand, with major volcanic centers within ~200km of the sample site. However, major cation concentrations increase in the downslope direction suggesting that advection of mass from the upper slope is the dominant mechanism.

  2. Migratory bird studies in Alaska: Comparative behavior and ecology of loons: Annual progress report, Northern Prairie Wildlife Research Center, January 1, 1970 to December 31, 1970

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Breeding biology of loon in the North slope region of Alaska. Mentions yellow-billed loons, artic loons, and red-throated loons. Studied courtship, nesting,...

  3. 75 FR 52370 - Notice of Public Meeting, North Slope Science Initiative-Science Technical Advisory Panel

    Science.gov (United States)

    2010-08-25

    ... plan to attend and need special assistance, such as sign language interpretation, transportation, or... do so. Dated: August 18, 2010. Julia Dougan, Acting Alaska State Director. BILLING CODE 1310-JA-M...

  4. Exploring Alaska's Seamounts on RV Atlantis in North Pacific Ocean and Gulf of Alaska between 20040730 and 20040823

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Five seamounts (Denson, Dickins, Pratt, Welker and Giacomini) in the Gulf of Alaska that had not previously been observed by manned submersible or ROV were...

  5. The effect of slope exposition on the growth dynamics of Larix gmelinii in permafrost conditions of Central Siberia. I. Differences in tree radial dynamics growth in the north- and south-facing slopes

    Directory of Open Access Journals (Sweden)

    А. V. Benkova

    2015-08-01

    Full Text Available This paper is devoted to revealing the distinctive characteristics of radial growth of larch trees (Larix gmelinii (Rupr. Rupr. growing in permafrost contrast conditions of the north and south facing slopes (Central Siberia, 64°19´23˝ N, 100°13´28˝ E. Even-aged larch stems regenerated after strong fire in 1899 in opposite north and south facing slopes of the hills situated on the banks of Kulingdakan stream were under study. Two sample sites at the middle part of the slopes were established. 23 model trees in the north facing slope and 13 ones in the south-facing slope were selected for dendrochronological analysis. From each tree, disks at 1.3 m height of the stems were taken. Tree ring widths were measured, comparative analysis of dynamics of radial growth in the slopes was made. In order to separate time intervals, characterized by distinctive climate impact on radial increment, sliding response functions were calculated and analyzed. Daily solar radiation for both sample sites was calculated. The results showed that solar radiation in the north-facing slope is 20 % less than that in south-facing slope. Solar radiation regime promotes intensive thickening of moss-lichen cover, so that its thickness to 2009 was nearly two times thicker than in south-facing slope. Both factors affected the worth thermal soil growth conditions in the north facing slope. The latter was responsible for narrower ring widths formation in the stems and governed higher sensitivity of the trees to air temperature in the periods of cambium reactivation, start and intensive growth.

  6. Literature and information related to the natural resources of the North Aleutian Basin of Alaska.

    Energy Technology Data Exchange (ETDEWEB)

    Stull, E.A.; Hlohowskyj, I.; LaGory, K. E.; Environmental Science Division

    2008-01-31

    The North Aleutian Basin Planning Area of the Minerals Management Service (MMS) is a large geographic area with significant natural resources. The Basin includes most of the southeastern part of the Bering Sea Outer Continental Shelf, including all of Bristol Bay. The area supports important habitat for a wide variety of species and globally significant habitat for birds and marine mammals, including several federally listed species. Villages and communities of the Alaska Peninsula and other areas bordering or near the Basin rely on its natural resources (especially commercial and subsistence fishing) for much of their sustenance and livelihood. The offshore area of the North Aleutian Basin is considered to have important hydrocarbon reserves, especially natural gas. In 2006, the MMS released a draft proposed program, 'Outer Continental Shelf Oil and Gas Leasing Program, 2007-2012' and an accompanying draft programmatic environmental impact statement (EIS). The draft proposed program identified two lease sales proposed in the North Aleutian Basin in 2010 and 2012, subject to restrictions. The area proposed for leasing in the Basin was restricted to the Sale 92 Area in the southwestern portion. Additional EISs will be needed to evaluate the potential effects of specific lease actions, exploration activities, and development and production plans in the Basin. A full range of updated multidisciplinary scientific information will be needed to address oceanography, fate and effects of oil spills, marine ecosystems, fish, fisheries, birds, marine mammals, socioeconomics, and subsistence in the Basin. Scientific staff at Argonne National Laboratory were contracted to assist MMS with identifying and prioritizing information needs related to potential future oil and gas leasing and development activities in the North Aleutian Basin. Argonne focused on three related tasks: (1) identify and gather relevant literature published since 1996, (2) synthesize and

  7. AFSC/REFM: Community Profiles for North Pacific Fisheries, Alaska 2011

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In 2005, the Alaska Fisheries Science Center (AFSC) compiled baseline socioeconomic information about 136 Alaska communities most involved in commercial fisheries....

  8. North Slope Inupiaq Grammar, Second Year (Preliminary Edition for Student Use Only).

    Science.gov (United States)

    MacLean, Edna Ahgeak

    The second-year grammar of Inupiaq, an Eskimo language spoken in northwestern Alaska, contains six chapters on these grammatical constructions: contemporative I mood; operative-imperative and negative contemporative moods; demonstrative adverbs in locative, vialis, ablative, and terminalis; transitive "present" and "past" tense…

  9. 75 FR 79017 - Notice of Public Meeting, North Slope Science Initiative-Science Technical Advisory Panel

    Science.gov (United States)

    2010-12-17

    ..., Interior. ACTION: Notice of public meeting. SUMMARY: In accordance with the Federal Land Policy and... will begin at 9 a.m. each day, at the University of Alaska Fairbanks, International Arctic Research..., cultural and Arctic fisheries. Planning for an NSSI workshop to be held in Barrow on March 29-31,...

  10. Temperature data acquired from the DOI/GTN-P Deep Borehole Array on the Arctic Slope of Alaska, 1973–2013

    Directory of Open Access Journals (Sweden)

    G. D. Clow

    2014-01-01

    Full Text Available A homogeneous set of temperature measurements obtained from the DOI/GTN-P Deep Borehole Array between 1973 and 2013 is presented. The 23-element array is located on the Arctic Slope of Alaska, a region of cold continuous permafrost. Most of the monitoring wells are situated on the arctic coastal plain between the Brooks Range and the Arctic Ocean, while others are in the foothills to the south. The data represent the true temperatures in the wellbores and surrounding rocks at the time of the measurements; they have not been corrected to remove the thermal disturbance caused by drilling the wells. With a few exceptions, the drilling disturbance is estimated to have been of order 0.1 K or less by 1989. Thus, most of the temperature measurements acquired during the last 25 yr are little affected by the drilling disturbance. The data contribute to ongoing efforts to monitor changes in the thermal state of permafrost in both hemispheres by the Global Terrestrial Network for Permafrost (GTN-P, one of the primary subnetworks of the Global Terrestrial Observing System (GTOS. The data will also be useful for refining our basic understanding of the physical conditions in permafrost in arctic Alaska, as well as provide important information for validating predictive models used for climate impact assessments. The processed data are available from the ACADIS repository at doi:10.5065/D6N014HK.

  11. Observations of the evening transition processes on opposing slopes of a north-south oriented mountain

    Science.gov (United States)

    Pardyjak, E.

    2014-12-01

    The MATERHORN (Mountain Terrain Atmospheric Modeling and Observation) Program is a multiuniversity, multidisciplinary research initiative designed to improve numerical weather prediction in complex terrain and to better understand the physics of complex terrain flow phenomena across a wide range of scales. As part of MATERHORN, field campaigns were conducted at Dugway, UT, USA in Autumn 2012 and Spring 2013. A subset of the campaigns included dense observations along the East Slope of Granite Peak (40.096° N, -113.253° W), as well as additional observations on the opposing west facing slope. East Slope observations included five multi-sonic anemometer eddy covariance towers (two with full energy budget stations), eleven small energy budget stations, fifteen automated weather stations, a distributed temperature sensing (DTS) system, hot-film anemometry, infrared camera surface temperature observations and up to three Doppler lidars. West Slope operations were less intense with three main towers, two of which included sonic anemometry and one, which included full surface energy balance observations. For this presentation, our analysis will focus on characterizing and contrasting the response of mean wind circulations and thermodynamics variables, as well as turbulence quantities during the evening transitions on both the East Slope and West Slope when solar irradiation differences of the slope surfaces is extremely large.

  12. Ship Track for Islands in the Stream 2002 - Exploration of Outer Shelf and Slope Habitats off the Coast of North Carolina - Office of Ocean Exploration

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Ship track of the R/V Seward Johnson during the 2002 "Islands in the Stream - Exploration of Outer Shelf and Slope Habitats off the Coast of North Carolina"...

  13. POTENTIALLY UNSTABLE SLOPE ABOVE ORE PROCESSING PLANT IN THE "OČURA" DOLOMITE QUARRY (LEPOGLAVA, NORTH CROATIA

    Directory of Open Access Journals (Sweden)

    Karlo Braun

    1993-12-01

    Full Text Available The complex engineering investigation, in the nearest surroun-dig of the conditionally stable high slope, close to ore processing facilities in the dolomite quarry »Očura« near Lepoglava (North Croatia, was carried out. Studying the tectonic features of the rock mass, discontinuities referent to the slope stability, was found out. Rock fragment size was measured and data processed using statistical design. According to rock fragment mean values, velocity of the longitudinal seismic waves was predicted. This values was compared with velocities of the longitudinal seismic waves, determined using gcophisical refraction seismic method. Physical and mechanical properties of the dolomite rock mass, considering longitudinal and transversal seismic wave velocities, and »RMR«-classification was assesed. All the results indicate, that the slope above the ore processing facilities should be consider as conditionally stable, with real probability to get unstable under the vibrations caused by blasting, during the exploitation in the field, close behind the investigated slope (the paper is published in Croatian.

  14. Mass transport deposits and processes in the north slope of the Xisha Trough, northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    QIN Zhiliang; WU Shiguo; WANG Dawei; LI Wei; GONG Shaojun; MI Lijun; SPENCE George

    2015-01-01

    Triple mass-transport deposits (MTDs) with areas of 625, 494 and 902 km2, respectively, have been identified on the north slope of the Xisha Trough, northern South China Sea margin. Based on high-resolution seismic reflection data and multi-beam bathymetric data, the Quaternary MTDs are characterized by typical geometric shapes and internal structures. Results of slope analysis showed that they are developed in a steep slope ranging from 5° to 35°. The head wall scarps of the MTDs arrived to 50 km in length (from headwall to termination). Their inner structures include well developed basal shear surface, growth faults, stepping lateral scarps, erosion grooves, and frontal thrust deformation. From seismic images, the central deepwater channel system of the Xisha Trough has been filled by interbedded channel-levee deposits and thick MTDs. Therefore, we inferred that the MTDs in the deepwater channel system could be dominated by far-travelled slope failure deposits even though there are local collapses of the trough walls. And then, we drew the two-dimensional process model and three-dimensional structure model diagram of the MTDs. Combined with the regional geological setting and previous studies, we discussed the trigger mechanisms of the triple MTDs.

  15. Temperature data acquired from the DOI/GTN-P Deep Borehole Array on the Arctic Slope of Alaska, 1973-2013

    Science.gov (United States)

    Clow, G. D.

    2014-05-01

    A homogeneous set of temperature measurements obtained from the DOI/GTN-P Deep Borehole Array between 1973 and 2013 is presented; DOI/GTN-P is the US Department of the Interior contribution to the Global Terrestrial Network for Permafrost (GTN-P). The 23-element array is located on the Arctic Slope of Alaska, a region of cold continuous permafrost. Most of the monitoring wells are situated on the Arctic coastal plain between the Brooks Range and the Arctic Ocean, while others are in the foothills to the south. The data represent the true temperatures in the wellbores and surrounding rocks at the time of the measurements; they have not been corrected to remove the thermal disturbance caused by drilling the wells. With a few exceptions, the drilling disturbance is estimated to have been on the order of 0.1 K or less by 1989. Thus, most of the temperature measurements acquired during the last 25 yr are little affected by the drilling disturbance. The data contribute to ongoing efforts to monitor changes in the thermal state of permafrost in both hemispheres by the Global Terrestrial Network for Permafrost, one of the primary subnetworks of the Global Terrestrial Observing System (GTOS). The data will also be useful for refining our basic understanding of the physical conditions in permafrost in Arctic Alaska, as well as providing important information for validating predictive models used for climate impact assessments. The processed data are available from the Advanced Cooperative Arctic Data and Information Service (ACADIS) repository at doi:10.5065/D6N014HK.

  16. Temperature data acquired from the DOI/GTN-P Deep Borehole Array on the Arctic Slope of Alaska, 1973–2013

    Directory of Open Access Journals (Sweden)

    G. D. Clow

    2014-05-01

    Full Text Available A homogeneous set of temperature measurements obtained from the DOI/GTN-P Deep Borehole Array between 1973 and 2013 is presented; DOI/GTN-P is the US Department of the Interior contribution to the Global Terrestrial Network for Permafrost (GTN-P. The 23-element array is located on the Arctic Slope of Alaska, a region of cold continuous permafrost. Most of the monitoring wells are situated on the Arctic coastal plain between the Brooks Range and the Arctic Ocean, while others are in the foothills to the south. The data represent the true temperatures in the wellbores and surrounding rocks at the time of the measurements; they have not been corrected to remove the thermal disturbance caused by drilling the wells. With a few exceptions, the drilling disturbance is estimated to have been on the order of 0.1 K or less by 1989. Thus, most of the temperature measurements acquired during the last 25 yr are little affected by the drilling disturbance. The data contribute to ongoing efforts to monitor changes in the thermal state of permafrost in both hemispheres by the Global Terrestrial Network for Permafrost, one of the primary subnetworks of the Global Terrestrial Observing System (GTOS. The data will also be useful for refining our basic understanding of the physical conditions in permafrost in Arctic Alaska, as well as providing important information for validating predictive models used for climate impact assessments. The processed data are available from the Advanced Cooperative Arctic Data and Information Service (ACADIS repository at doi:10.5065/D6N014HK.

  17. Literature and information related to the natural resources of the North Aleutian Basin of Alaska.

    Energy Technology Data Exchange (ETDEWEB)

    Stull, E.A.; Hlohowskyj, I.; LaGory, K. E.; Environmental Science Division

    2008-01-31

    The North Aleutian Basin Planning Area of the Minerals Management Service (MMS) is a large geographic area with significant natural resources. The Basin includes most of the southeastern part of the Bering Sea Outer Continental Shelf, including all of Bristol Bay. The area supports important habitat for a wide variety of species and globally significant habitat for birds and marine mammals, including several federally listed species. Villages and communities of the Alaska Peninsula and other areas bordering or near the Basin rely on its natural resources (especially commercial and subsistence fishing) for much of their sustenance and livelihood. The offshore area of the North Aleutian Basin is considered to have important hydrocarbon reserves, especially natural gas. In 2006, the MMS released a draft proposed program, 'Outer Continental Shelf Oil and Gas Leasing Program, 2007-2012' and an accompanying draft programmatic environmental impact statement (EIS). The draft proposed program identified two lease sales proposed in the North Aleutian Basin in 2010 and 2012, subject to restrictions. The area proposed for leasing in the Basin was restricted to the Sale 92 Area in the southwestern portion. Additional EISs will be needed to evaluate the potential effects of specific lease actions, exploration activities, and development and production plans in the Basin. A full range of updated multidisciplinary scientific information will be needed to address oceanography, fate and effects of oil spills, marine ecosystems, fish, fisheries, birds, marine mammals, socioeconomics, and subsistence in the Basin. Scientific staff at Argonne National Laboratory were contracted to assist MMS with identifying and prioritizing information needs related to potential future oil and gas leasing and development activities in the North Aleutian Basin. Argonne focused on three related tasks: (1) identify and gather relevant literature published since 1996, (2) synthesize and

  18. Gathering and Gardening in Alaska: Why IPM cannot be overlooked even at Latitude 64° North

    Science.gov (United States)

    Because of its geographical isolation and climatic constraints, Alaska agriculture is considered relatively free of diseases and insect pests. Early colonizers into the state did not encounter the pest problems of modern farmers. However, since 1973, the winter temperatures in Alaska have increased ...

  19. Contaminant concerns for West River National Wildlife Refuges: Slope and Dunn Counties, North Dakota

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — From 1990 to 1993 three National Wildlife Refuges (NWRs) located west of the Missouri River in North Dakota were surveyed for contaminants. Trace element...

  20. 348-YEAR PRECIPITATION RECONSTRUCTION FROM TREE-RINGS FOR THE NORTH SLOPE OF THE MIDDLE TIANSHAN MOUNTAINS

    Institute of Scientific and Technical Information of China (English)

    袁玉江; 李江风; 张家宝

    2001-01-01

    Correlation census shows that the correlation between the tree-ring chronologies in the Urumqi River Basin and precipitation during July in the last year to February in the concurrent year is significant, and the best single correlation coefficient is 0.74, with significance level of 0. 0001.Using two residual chronologies collected from west Baiyanggou and Boerqingou, precipitation for 348 years can be reconstructed in the North Slope of middle Tianshan Mountains, its explained variance is 62%. According to much verification from independent precipitation data, historical climate records, glacier and other data, it shows that the reconstructed precipitation series of 348 years is reliable. Analysis of precipitation features indicates that there were three wet periods occurring during 1671 (?) -1692, 1716-1794 and 1825-1866 and three dry periods during 1693 - 1715, 1795- 1824 and 1867- 1969. Two wet periods, during 1716- 1794 and 1825 - 1866,correspond to the times of the second and the third glacial terminal moraine formation, which is in front of No. 1 glacier in Urumqi River source. According to computation, corresponding annual precipitation amounts are 59 mm and 30 mm more than now. The reconstructed precipitation series has a significant drying trend from 1716 to 1969, and has better representativeness to the precipitation of Urumqi and Changji Prefecture on the North Slope of Tianshan Mountains.

  1. 78 FR 59714 - Notice of Public Meeting, North Slope Science Initiative-Science Technical Advisory Panel

    Science.gov (United States)

    2013-09-27

    ..., Interior. ACTION: Notice of public meeting. SUMMARY: In accordance with the Federal Land Policy and... begin at 9:00 a.m. in the Akasofu Building, International Arctic Research Center (IARC), Room 401, North... interactive session on remote ] sensing-derived monitoring products for the Arctic will provide...

  2. Response of rock-fissure seepage to snowmelt in Mount Taihang slope-catchment, North China.

    Science.gov (United States)

    Cao, Jiansheng; Liu, Changming; Zhang, Wanjun

    2013-01-01

    The complex physiographic and hydrogeological systems of mountain terrains facilitate intense rock-fissure seepages and multi-functional ecological interactions. As mountain eco-hydrological terrains are the common water sources of river basins across the globe, it is critical to build sufficient understanding into the hydrological processes in this unique ecosystem. This study analyzes infiltration and soil/rock-fissure seepage processes from a 65 mm snowfall/melt in November 2009 in the typical granitic gneiss slope catchment in the Taihang Mountains. The snowfall, snowmelt and melt-water processes are monitored using soil-water time-domain reflectometry (TDR) probes and tipping bucket flowmeters. The results suggest that snowmelt infiltration significantly influences soil/rock water seepage in the 0-100 cm soil depth of the slope-catchment. It is not only air temperature that influences snowmelt, but also snowmelt infiltration and rock-fissure seepage. Diurnal variations in rock-fissure seepage are in close correlation with air temperature (R(2) > 0.7). Temperature also varies with soil/rock water viscosity, which element in turn influences soil/rock water flow. Invariably, water dynamics in the study area is not only a critical water supply element for domestic, industrial and agricultural uses, but also for food security and social stability.

  3. The Structure of Genetic Diversity in Eelgrass (Zostera marina L.) along the North Pacific and Bering Sea Coasts of Alaska

    Science.gov (United States)

    Talbot, Sandra; Sage, Kevin; Rearick, Jolene; Fowler, Megan C.; Muñiz-Salazar, Raquel; Baibak, Bethany; Wyllie-Echeverria, Sandy; Cabello-Pasini, Alehandro; Ward, David H.

    2016-01-01

    Eelgrass (Zostera marina) populations occupying coastal waters of Alaska are separated by a peninsula and island archipelago into two Large Marine Ecosystems (LMEs). From populations in both LMEs, we characterize genetic diversity, population structure, and polarity in gene flow using nuclear microsatellite fragment and chloroplast and nuclear sequence data. An inverse relationship between genetic diversity and latitude was observed (heterozygosity: R2 = 0.738, P < 0.001; allelic richness: R2 = 0.327, P = 0.047), as was significant genetic partitioning across most sampling sites (θ = 0.302, P < 0.0001). Variance in allele frequency was significantly partitioned by region only in cases when a population geographically in the Gulf of Alaska LME (Kinzarof Lagoon) was instead included with populations in the Eastern Bering Sea LME (θp = 0.128–0.172; P < 0.003), suggesting gene flow between the two LMEs in this region. Gene flow among locales was rarely symmetrical, with notable exceptions generally following net coastal ocean current direction. Genetic data failed to support recent proposals that multiple Zostera species (i.e. Z. japonica and Z. angustifolia) are codistributed with Z. marina in Alaska. Comparative analyses also failed to support the hypothesis that eelgrass populations in the North Atlantic derived from eelgrass retained in northeastern Pacific Last Glacial Maximum refugia. These data suggest northeastern Pacific populations are derived from populations expanding northward from temperate populations following climate amelioration at the terminus of the last Pleistocene glaciation.

  4. Single nucleotide polymorphism (SNP) variation of wolves (Canis lupus) in Southeast Alaska and comparison with wolves, dogs, and coyotes in North America.

    Science.gov (United States)

    Cronin, Matthew A; Cánovas, Angela; Bannasch, Danika L; Oberbauer, Anita M; Medrano, Juan F

    2015-01-01

    There is considerable interest in the genetics of wolves (Canis lupus) because of their close relationship to domestic dogs (C. familiaris) and the need for informed conservation and management. This includes wolf populations in Southeast Alaska for which we determined genotypes of 305 wolves at 173662 single nucleotide polymorphism (SNP) loci. After removal of invariant and linked SNP, 123801 SNP were used to quantify genetic differentiation of wolves in Southeast Alaska and wolves, coyotes (C. latrans), and dogs from other areas in North America. There is differentiation of SNP allele frequencies between the species (wolves, coyotes, and dogs), although differentiation is relatively low between some wolf and coyote populations. There are varying levels of differentiation among populations of wolves, including low differentiation of wolves in interior Alaska, British Columbia, and the northern US Rocky Mountains. There is considerable differentiation of SNP allele frequencies of wolves in Southeast Alaska from wolves in other areas. However, wolves in Southeast Alaska are not a genetically homogeneous group and there are comparable levels of genetic differentiation among areas within Southeast Alaska and between Southeast Alaska and other geographic areas. SNP variation and other genetic data are discussed regarding taxonomy and management.

  5. The biogeochemistry of carbon in continental slope sediments: The North Carolina margin

    Energy Technology Data Exchange (ETDEWEB)

    Blair, N.; Levin, L.; DeMaster, D.; Plaia, G.; Martin, C.; Fornes, W.; Thomas, C.; Pope, R.

    1999-12-01

    The responses of the continental slope benthos to organic detritus deposition were studied with a multiple trace approach. Study sites were offshore of Cape Fear (I) and Cape Hatteras (III), N.C. (both 850 m water depth) and were characterized by different organic C deposition rates, macrofaunal densities (III>I in both cases) and taxa. Natural abundances of {sup 13}C and {sup 12}C in particulate organic carbon (POC), dissolved inorganic carbon (DIC) and macrofauna indicate that the reactive organic detritus is marine in origin. Natural abundance levels of {sup 14}C and uptake of {sup 13}C-labeled diatoms by benthic animals indicate that they incorporate a relatively young component of carbon into their biomass. {sup 13}C-labeled diatoms (Thalassiorsira pseudonana) tagged with {sup 210}Pb, slope sediment tagged with {sup 113}Sn and {sup 228}Th-labeled glass beads were emplaced in plots on the seafloor at both locations and the plots were sampled after 30 min., 1-1.5 d and 14 mo. At Site I, tracer diatom was intercepted at the surface primarily by protozoans and surface-feeding annelids. Little of the diatom C penetrated below 2 cm even after 14 months. Oxidation of organic carbon appeared to be largely aerobic. At Site III, annelids were primarily responsible for the initial uptake of tracer. On the time scale of days, diatom C was transported to a depth of 12 cm and was found in animals collected between 5-10 cm. The hoeing of tracer from the surface by the maldanid Praxillela sp. may have been responsible for some of the rapid nonlocal transport. Oxidation of the diatom organic carbon was evident to at least 10 cm depth. Anaerobic breakdown of organic matter is more important at Site III. Horizontal transport, which was probably biologically mediated, was an order of magnitude more rapid than vertical displacement over a year time scale. If the horizontal transport was associated with biochemical transformations of the organic matter, it may represent an

  6. Alaska Coal Geology, Resources, and Coalbed Methane Potential

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Estimated Alaska coal resources are largely in Cretaceous and Tertiary rocks distributed in three major provinces. Northern Alaska-Slope, Central Alaska-Nenana, and...

  7. North-south comparison of springtime dark slope structures on Mars, and the possibility of liquid water

    Science.gov (United States)

    Kereszturi, A.; Berczi, Sz.; Horvath, A.; Ganti, T.; Kuti, A.; Pocs, T.; Sik, A.; Szathmary, E.

    2008-09-01

    Introduction Various polar seasonal surface albedo structures were analyzed by several authors in the past [1, 2, 3, 4, 5, 6, 7, 8, 8, 9], partly in connection with the possibility of liquid water. In our previous work [10] we identified two groups of slope streaks emanating form Dark Dune Spots of polar dunes, which grow in size and number during spring with the advancement of the season. The diffuse shaped group appears earlier and formed probably by CO2 geysers [8]. The confine shaped group appears in a later seasonal phase, when the temperature is higher. They are probably connected with exposed water-ice on the surface, and may formed by the seepage of undercooled interfacial water on microscopic scale [11]. Methods For the analysis of northern slope structures we used MGS MOC, MRO HiRISE images, and MRG TES data [12] using the "vanilla" software. Temperature data show annual trend, and were derived for daytime. Note that the surface temperature values have spatial resolution around 3 km, and they can be taken only as a rough approach of the surface temperature of the whole dune complex, and not different parts of it. Discussion The target area of the analysis was (84N 233E) in the northern circumpolar sand sea, with 300-500 m diameter overlapping dunes. We searched for springtime confined and elongated dark slope streaks, similar to those, which we observed at south. Basic similarities between northern and southern structures are: 1. streaks always emanate from Dark Dune Spots in downward direction, 2. streaks are present in local spring, when the temperature is above the CO2 buffered level, suggesting there are parts of the surface without CO2 ice, where possibly H2O ice is exposed (Fig. 1.), 4. the streaks show branching pattern (Fig. 2.). Basic differences between the northern and southern structures: 1. at north there is a dark annulus around the Dark Dune Spots, which is absent at south, 2. there are fewer and fainter diffuse streaks of gas jet activity

  8. Alaska's indigenous muskoxen: a history

    Directory of Open Access Journals (Sweden)

    Peter C. Lent

    1998-03-01

    Full Text Available Muskoxen (Ovibos moschatus were widespread in northern and interior Alaska in the late Pleistocene but were never a dominant component of large mammal faunas. After the end of the Pleistocene they were even less common. Most skeletal finds have come from the Arctic Coastal Plain and the foothills of the Brooks Range. Archaeological evidence, mainly from the Point Barrow area, suggests that humans sporadically hunted small numbers of muskoxen over about 1500 years from early Birnirk culture to nineteenth century Thule culture. Skeletal remains found near Kivalina represent the most southerly Holocene record for muskoxen in Alaska. Claims that muskoxen survived into the early nineteenth century farther south in the Selawik - Buckland River region are not substantiated. Remains of muskox found by Beechey's party in Eschscholtz Bay in 1826 were almost certainly of Pleistocene age, not recent. Neither the introduction of firearms nor overwintering whalers played a significant role in the extinction of Alaska's muskoxen. Inuit hunters apparently killed the last muskoxen in northwestern Alaska in the late 1850s. Several accounts suggest that remnant herds survived in the eastern Brooks Range into the 1890s. However, there is no physical evidence or independent confirmation of these reports. Oral traditions regarding muskoxen survived among the Nunamiut and the Chandalar Kutchin. With human help, muskoxen have successfully recolonized their former range from the Seward Peninsula north, across the Arctic Slope and east into the northern Yukon Territory.

  9. Introduction to the North Pacific Research Board Gulf of Alaska Integrated Ecosystem Research Program (GOAIERP): Volume I

    Science.gov (United States)

    Dickson, Danielle M. S.; Baker, Matthew R.

    2016-10-01

    The North Pacific Research Board (NPRB) supports research to address pressing fishery management and ecosystem information needs in the marine waters of Alaska. Understanding dynamics at the scale of ecosystems requires integrated approaches that explore underlying mechanistic processes and interactions. It also requires analytic approaches that investigate the influence, cause, effect, and relative importance of various phenomena and drivers in determining ecosystem structure, processes and biophysical interactions. To address ecosystem-level hypotheses and questions at this scale, NPRB developed the Integrated Ecosystem Research Program (IERP). These programs employ multi-disciplinary and multi-institutional approaches to investigating ecosystem processes. The aim is to provide a basis for understanding core processes and to provide information and products that have targeted application to management priorities.

  10. Soil Sampling and Analysis Plan for the McGee Ranch-Riverlands and North Slope Units of the Hanford Reach National Monument

    Energy Technology Data Exchange (ETDEWEB)

    Fritz, Brad G.; Dirkes, Roger L.

    2004-12-27

    This document describes soil sampling that will be performed by Pacific Northwest National Laboratory's Surface Environmental Surveillance Project on two units of the Hanford Reach National Monument: the McGee Ranch-Riverlands Unit (Riverlands Unit) and the North Slope made up of the Saddle Mountain Unit and the Wahluke Slope Unit. This sampling fulfills a U.S. Department of Energy requirement to evaluate the potential for residual radioactive contamination on this land and determine compliance with the requirements of DOE Order 5400.5 prior to radiological release of the property.

  11. Physical and underway data collected aboard the Marcus G. Langseth during cruise MGL1109 in the Gulf of Alaska and North Pacific Ocean from 2011-06-06 to 2011-06-26 (NODC Accession 0104306)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0104306 includes physical and underway data collected aboard the Marcus G. Langseth during cruise MGL1109 in the Gulf of Alaska and North Pacific...

  12. Physical and underway data collected aboard the ATLANTIS during cruise AT15-67 in the Coastal Waters of SE Alaska and North Pacific Ocean from 2010-07-06 to 2010-07-27 (NODC Accession 0103934)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0103934 includes physical and underway data collected aboard the ATLANTIS during cruise AT15-67 in the Coastal Waters of SE Alaska and North Pacific...

  13. Physical and underway data collected aboard the THOMAS G. THOMPSON during cruise TN283 in the Coastal Waters of SE Alaska and North Pacific Ocean from 2012-03-11 to 2012-07-24 (NODC Accession 0104385)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0104385 includes physical and underway data collected aboard the THOMAS G. THOMPSON during cruise TN283 in the Coastal Waters of SE Alaska and North...

  14. Physical and underway data collected aboard the WECOMA during cruise W1009B in the Coastal Waters of SE Alaska and North Pacific Ocean from 2010-09-21 to 2010-10-09 (NODC Accession 0104379)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0104379 includes physical and underway data collected aboard the WECOMA during cruise W1009B in the Coastal Waters of SE Alaska and North Pacific...

  15. Chemical, physical and underway data collected aboard the HEALY during cruise HLY11TA in the Coastal Waters of SE Alaska and North Pacific Ocean from 2011-04-25 to 2011-05-07 (NODC Accession 0103989)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0103989 includes chemical, physical and underway data collected aboard the HEALY during cruise HLY11TA in the Coastal Waters of SE Alaska and North...

  16. Fish survey, fishing duration, and other data from net trawls in the Gulf of Alaska from the NORTH PACIFIC as part of Outer Continental Shelf Environmental Assessment Program (OCSEAP) from 03 May 1975 to 07 August 1975 (NODC Accession 7601886)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish survey, fishing duration, and other data were collected from net trawls in the Gulf of Alaska from the NORTH PACIFIC from 03 May 1975 to 07 August 1975. Data...

  17. Physical and profile data collected aboard the MELVILLE during cruise MV1403 in the Coastal Waters of SE Alaska and North Pacific Ocean from 2014-05-13 to 2014-06-06 (NCEI Accession 0132044)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0132044 includes physical and profile data collected aboard the MELVILLE during cruise MV1403 in the Coastal Waters of SE Alaska and North Pacific...

  18. Physical and underway data collected aboard the ATLANTIS during cruise AT15-47 in the Coastal Waters of SE Alaska and North Pacific Ocean from 2009-06-13 to 2009-06-28 (NODC Accession 0103877)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0103877 includes physical and underway data collected aboard the ATLANTIS during cruise AT15-47 in the Coastal Waters of SE Alaska and North Pacific...

  19. Physical and underway data collected aboard the WECOMA during cruise W1010C in the Coastal Waters of SE Alaska and North Pacific Ocean from 2010-10-22 to 2010-11-01 (NODC Accession 0104380)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0104380 includes physical and underway data collected aboard the WECOMA during cruise W1010C in the Coastal Waters of SE Alaska and North Pacific...

  20. Fish survey, fishing duration, and other data from net trawls in the Gulf of Alaska from the NORTH PACIFIC as part of Outer Continental Shelf Environmental Assessment Program (OCSEAP) from 03 May 1975 to 07 August 1975 (NODC Accession 7601885)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish survey, fishing duration, and other data were collected from net trawls in the Gulf of Alaska from the NORTH PACIFIC from 03 May 1975 to 07 August 1975. Data...

  1. Physical and underway data collected aboard the HEALY during cruise HLY11TB in the Coastal Waters of SE Alaska and North Pacific Ocean from 2011-05-27 to 2011-06-04 (NODC Accession 0103994)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0103994 includes physical and underway data collected aboard the HEALY during cruise HLY11TB in the Coastal Waters of SE Alaska and North Pacific...

  2. Atlas of Relations Between Climatic Parameters and Distributions of Important Trees and Shrubs in North America - Alaska Species and Ecoregions

    Science.gov (United States)

    Thompson, Robert S.; Anderson, Katherine H.; Strickland, Laura E.; Shafer, Sarah L.; Pelltier, Richard T.; Bartlein, Patrick J.

    2006-01-01

    Climate is the primary factor in controlling the continental-scale distribution of plant species, although the relations between climatic parameters and species' ranges is only now beginning to be quantified. Preceding volumes of this atlas explored the continental-scale relations between climatic parameters and the distributions of woody plant species across all of the continent of North America. This volume presents similar information for important woody species, groups of species, and ecoregions in more detail for the State of Alaska. For these analyses, we constructed a 25-kilometer equal-area grid of modern climatic and bioclimatic parameters for North America from instrumental weather records. We obtained a digital representation of the geographic distribution of each species or ecoregion, either from a published source or by digitizing the published distributions ourselves. The presence or absence of each species or ecoregion was then determined for each point on the 25-kilometer grid, thus providing a basis for comparison of the climatic data with the geographic distribution of each species or ecoregion. The relations between climate and these distributions are presented in graphical and tabular form.

  3. Alaska Energy Inventory Project: Consolidating Alaska's Energy Resources

    Science.gov (United States)

    Papp, K.; Clough, J.; Swenson, R.; Crimp, P.; Hanson, D.; Parker, P.

    2007-12-01

    Alaska has considerable energy resources distributed throughout the state including conventional oil, gas, and coal, and unconventional coalbed and shalebed methane, gas hydrates, geothermal, wind, hydro, and biomass. While much of the known large oil and gas resources are concentrated on the North Slope and in the Cook Inlet regions, the other potential sources of energy are dispersed across a varied landscape from frozen tundra to coastal settings. Despite the presence of these potential energy sources, rural Alaska is mostly dependent upon diesel fuel for both electrical power generation and space heating needs. At considerable cost, large quantities of diesel fuel are transported to more than 150 roadless communities by barge or airplane and stored in large bulk fuel tank farms for winter months when electricity and heat are at peak demands. Recent increases in the price of oil have severely impacted the price of energy throughout Alaska, and especially hard hit are rural communities and remote mines that are off the road system and isolated from integrated electrical power grids. Even though the state has significant conventional gas resources in restricted areas, few communities are located near enough to these resources to directly use natural gas to meet their energy needs. To address this problem, the Alaska Energy Inventory project will (1) inventory and compile all available Alaska energy resource data suitable for electrical power generation and space heating needs including natural gas, coal, coalbed and shalebed methane, gas hydrates, geothermal, wind, hydro, and biomass and (2) identify locations or regions where the most economic energy resource or combination of energy resources can be developed to meet local needs. This data will be accessible through a user-friendly web-based interactive map, based on the Alaska Department of Natural Resources, Land Records Information Section's (LRIS) Alaska Mapper, Google Earth, and Terrago Technologies' Geo

  4. The Alaska Lake Ice and Snow Observatory Network (ALISON): Hands-on Experiential K- 12 Learning in the North

    Science.gov (United States)

    Morris, K.; Jeffries, M.

    2008-12-01

    The Alaska Lake Ice and Snow Observatory Network (ALISON) was initiated by Martin Jeffries (UAF polar scientist), Delena Norris-Tull (UAF education professor) and Ron Reihl (middle school science teacher, Fairbanks North Star Borough School District). The snow and ice measurement protocols were developed in 1999-2000 at the Poker Flat Research Range (PFRR) by Geophysical Institute, University of Alaska scientists and tested by home school teacher/students in winter 2001-2002 in Fairbanks, AK. The project was launched in 2002 with seven sites around the state (PFRR, Fairbanks, Barrow, Mystic Lake, Nome, Shageluk and Wasilla). The project reached its broadest distribution in 2005-2006 with 22 sites. The schools range from urban (Wasilla) to primarily Alaska native villages (Shageluk). They include public schools, charter schools, home schooled students and parents, informal educators and citizen scientists. The grade levels range from upper elementary to high school. Well over a thousand students have participated in ALISON since its inception. Equipment is provided to the observers at each site. Measurements include ice thickness (with a hot wire ice thickness gauge), snow depth and snow temperature (surface and base). Snow samples are taken and snow density derived. Snow variables are used to calculate the conductive heat flux through the ice and snow cover to the atmosphere. All data are available on the Web site. The students and teachers are scientific partners in the study of lake ice processes, contributing to new scientific knowledge and understanding while also learning science by doing science with familiar and abundant materials. Each autumn, scientists visit each location to work with the teachers and students, helping them to set up the study site, showing them how to make the measurements and enter the data into the computer, and discussing snow, ice and polar environmental change. A number of 'veteran' teachers are now setting up the study sites on

  5. [Differentiation of vegetation characteristics on slope micro-topography of fenced watershed in loess area of north Shaanxi Province, Northwest China].

    Science.gov (United States)

    Wang, Jing; Zhu, Qing-Ke; Qin, Wei; Zhang, Hong-Zhi; Yun, Lei; Xie, Jing; Kuang, Gao-Ming

    2012-03-01

    Based on the investigation data of the vegetations in Hegou valley in Wuqi County of Shaanxi Province, this paper studied the vegetation characteristics on the five typical micro-topography categories including shallow gully, gully, collapse, platform, and scarp in the loess area of north Shaanxi, with the undisturbed slope as the control. There existed distinct differences in the species composition, quantitative characteristics, and species diversity of plant communities on the five typical micro-topography categories and the undisturbed slope. After twelve years of enclosure recovery, the study area formed herbaceous plant community, with Artemisia sacrorum and Artemisia giraldii as the dominant species. Among the main companion species, shrubs such as Prinsepia uniflora and Caragana korshinskii were found in scarp and gully, and hygrophyte Phragmites australis appeared in platform. The coverage, height, and biomass of the plant communities on most of the micro-topography categories, especially on the gully and collapse, were larger than those on the undisturbed slope. The Shannon index on the micro-topography categories and undisturbed slope was in the order of scarp > gully > shallow gully > undisturbed slope > platform > collapse.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1978-09-01

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

  7. The Characteristic and Genesis of Volcanic Ash Soil in the North Slope Toposequence of Kawi Mountain in Malang Regency

    Directory of Open Access Journals (Sweden)

    A.N. Putra

    2015-07-01

    Full Text Available The volcanic ash soil in Kawi Mountain is composed by the amorphous materials consist of allophane, imogolite and ferrihydrite. Results of previous study showed that the phosphate retention in all soil profiles of northern slope toposequence of Kawimountain was less than 85%, yet the phosphate retention of volcanic ash soils is usually > 85 %. This raised a question that there is a different characteristics of soil in the northern slope tosequence of the Kawi Mountain compared to the other places. This research was conducted to study soil characteristics, mineral contents, and genesis processessoccuring in soil on the northern slope toposequence of Kawi Mountain. 5 pedons between high elevation and low elevation (P1, P2, P3, P4 and P5 to identified the soil characteristics. The Al, Fe, and Si extracted by acid oxalate, natrium pyrophosphate, and dithionite citrate to calculate the amorphous mineral content. The results show that. The results showed that there is a different in terms of the thickness of the A horizon, the C organic content and the soil acidity level that mainly found in P3 and P4 profiles. The most important soil genesis processess in the formation of the volcanic ash soils were likely clay illuviation (P5, melanization and braunification (P3, littering (P1 and the reduction of andic soil properties from the upper slope (P1 profile up to the lower slope (P5 profile.

  8. Gathering, Gardening, and Agricultural Production in Alaska: Why IPM Cannot Be Overlooked Even at Latitude 64° North.

    Science.gov (United States)

    Because of its geographical isolation and climate constraints, Alaska agriculture is considered relatively free of diseases and insect pests. Early colonizers into the state did not encounter the pest problems of modern farmers. However, since 1973, the winter temperatures in Alaska have increased 2...

  9. Development of a glacially dominated shelf-slope-fan system in tectonically active southeast Alaska: Results of IODP Expedition 341 core-log-seismic integrated studies at glacial cycle resolution

    Science.gov (United States)

    Gulick, Sean; Jaeger, John; Mix, Alan; Swartz, John; Worthington, Lindsay; Reece, Robert

    2014-05-01

    Collision of the Yakutat microplate with North American formed the St. Elias Mountains in coastal Gulf of Alaska. While the tectonic driver for orogenesis has been ongoing since the Miocene, results from the Integrated Ocean Drilling Program Expedition 341 suggests that direct climatic perturbation of active orogenesis through glacial erosion is non-linear. Geophysical studies of the glaciated continental margin, slope, and adjacent deep-sea Surveyor Fan allow examination of the glaciated orogen from source to sink. Using high-resolution and crustal-scale seismic data and through comparison with other glaciated margins, we can identify key diagnostic seismic morphologies and facies indicative of glacial proximity and sediment routing. Expedition drilling results calibrated these images suggesting a timeline for initial advances of the Cordilleran ice sheet related glacial systems onto the shelf and a further timeline for the development of ice streams that reach the shelf edge. Comparisons can be made within this single margin between evolution of the tectonic-glacial system where erosion and sediment transport are occurring within a fold and thrust belt versus on a more stable shelf region. Onshore the Bering-Bagley glacial system in the west flows across the Yakataga fold and thrust belt, allowing examination of whether glacial erosion can cause tectonic feedbacks, whereas offshore the Bering-Bagley system interacts with the Pamplona Zone thrusts in a region of significant sediment accommodation. Results from Expedition 341 imply that timing of glacial advance to the shelf edge in this region may be driven by the necessity of filling up the accommodation through aggradation followed by progradation and thus is autogenic. In contrast the Malaspina-Hubbard glacial system to the east encountered significantly less accommodation and more directly responded to climatic forcing including showing outer shelf glacial occupation since the mid-Pleistocene transition-MPT to

  10. Response of geomorphic and geological processes to insufficient and ample sediment supply along the upper continental slope in the north-western South China Sea

    Science.gov (United States)

    Chen, Hongjun; Zhan, Wenhuan; Wu, Shiguo

    2016-12-01

    We document upper slope sedimentary process and strata on the passive margin of the north-western South China Sea (SCS) using multibeam bathymetry and high-resolution seismic data. The upper slope can be divided into two segments based on geomorphology, strata, and sediment supply. (1) The east segment is characterised by deep incised canyons and gullies, and slope failure. Submarine canyons with both U- and V-shaped morphology (13-28 km long × 2-4 km wide) are oriented NNE-SSW or NNW-SSE and are approximately perpendicular to the slope. Erosion is dominant, with escarpments, slumps, and several mass transport deposits (MTDs). Shelf-margin clinoforms show strongly upward vertical aggradation with time and are strongly aggradational in style. Since 5.5 Ma, the shelf break line migrated southwards and then retreated to its present position. The segment is classified as erosion-dominated due to insufficient sediment supply. (2) The west segment has a smooth surface, gentle gradient, and a strongly progradational style, with MTDs triggered by high sedimentation rates. Shelf-margin clinoforms display a combination of progradational and aggradational stacking patterns. The shelf break line migrated southwards with time. The segment is classified as deposition-dominated, resulting from plentiful sediment supply. Depositional models have been constructed for each segment: a constant shelf break model with insufficient sediment supply in the east, and a migration shelf break model with plenty sediment supply in the west. This case study contributes to the understanding of the upper slope sedimentary process and stratigraphic style under different sediment supply conditions.

  11. Response of geomorphic and geological processes to insufficient and ample sediment supply along the upper continental slope in the north-western South China Sea

    Indian Academy of Sciences (India)

    Hongjun Chen; Wenhuan Zhan; Shiguo Wu

    2016-12-01

    We document upper slope sedimentary process and strata on the passive margin of the north-western South China Sea (SCS) using multibeam bathymetry and high-resolution seismic data. The upper slope can be divided into two segments based on geomorphology, strata, and sediment supply. (1) The east segment is characterised by deep incised canyons and gullies, and slope failure. Submarine canyons with both U- and V-shaped morphology (13−28 km long × 2−4 km wide) are oriented NNE−SSW or NNW−SSE and are approximately perpendicular to the slope. Erosion is dominant, with escarpments, slumps, and several mass transport deposits (MTDs). Shelf-margin clinoforms show strongly upward vertical aggradation with time and are strongly aggradational in style. Since 5.5 Ma, the shelf break line migrated southwards and then retreated to its present position. The segment is classified as erosion-dominated due to insufficient sediment supply. (2) The west segment has a smooth surface, gentle gradient, and a strongly progradational style, with MTDs triggered by high sedimentation rates. Shelf-margin clinoforms display a combination of progradational and aggradational stacking patterns. The shelf break line migrated southwards with time. The segment is classified as deposition-dominated, resulting from plentiful sediment supply. Depositional models have been constructed for each segment: a constant shelf break model with insufficient sediment supply in the east, and a migration shelf break model with plenty sediment supply in the west. This case study contributes to the understanding of the upper slope sedimentary process and stratigraphic style under different sediment supply conditions.

  12. Thermochronology in southeast Alaska and southwest Yukon: Implications for North American Plate response to terrane accretion

    Science.gov (United States)

    Enkelmann, Eva; Piestrzeniewicz, Adam; Falkowski, Sarah; Stübner, Konstanze; Ehlers, Todd A.

    2017-01-01

    This study presents the first comprehensive dataset of low-temperature thermochronology from 43 bedrock samples collected north of the active Yakutat-North American plate boundary. Our apatite and zircon (U-Th)/He and fission-track data reveal the cooling history of the inboard Wrangellia Composite Terrane that is dominated by rapid cooling after Late Jurassic to Early Cretaceous arc magmatism followed by very little cooling and exhumation until today. Deformation resulting in rock exhumation due to the collision of the Yakutat microplate is spatially very limited (20-30 km) and is concentrated mainly in the Chugach-Prince William Terrane and rocks near the Border Ranges Fault. Focused exhumation from greater depths of ca. 10 km with very high rates (>5 km/Myr) is localized at the syntaxis region, starting ca. 10 Ma and shifted south through time. The rapid exhumation rates are explained by the development of strong feedbacks between tectonically driven surface uplift and erosion, which started already before glaciation of the area. The shift in the location towards the south is a consequence of continuous readjusting between tectonics and climate, which is changing on local and global scales since the Late Miocene.

  13. Mapping Arctic Tundra Vegetation Communities Using Field Spectroscopy and Multispectral Satellite Data in North Alaska, USA

    Directory of Open Access Journals (Sweden)

    Scott J. Davidson

    2016-11-01

    Full Text Available The Arctic is currently undergoing intense changes in climate; vegetation composition and productivity are expected to respond to such changes. To understand the impacts of climate change on the function of Arctic tundra ecosystems within the global carbon cycle, it is crucial to improve the understanding of vegetation distribution and heterogeneity at multiple scales. Information detailing the fine-scale spatial distribution of tundra communities provided by high resolution vegetation mapping, is needed to understand the relative contributions of and relationships between single vegetation community measurements of greenhouse gas fluxes (e.g., ~1 m chamber flux and those encompassing multiple vegetation communities (e.g., ~300 m eddy covariance measurements. The objectives of this study were: (1 to determine whether dominant Arctic tundra vegetation communities found in different locations are spectrally distinct and distinguishable using field spectroscopy methods; and (2 to test which combination of raw reflectance and vegetation indices retrieved from field and satellite data resulted in accurate vegetation maps and whether these were transferable across locations to develop a systematic method to map dominant vegetation communities within larger eddy covariance tower footprints distributed along a 300 km transect in northern Alaska. We showed vegetation community separability primarily in the 450–510 nm, 630–690 nm and 705–745 nm regions of the spectrum with the field spectroscopy data. This is line with the different traits of these arctic tundra communities, with the drier, often non-vascular plant dominated communities having much higher reflectance in the 450–510 nm and 630–690 nm regions due to the lack of photosynthetic material, whereas the low reflectance values of the vascular plant dominated communities highlight the strong light absorption found here. High classification accuracies of 92% to 96% were achieved using

  14. Temperature data acquired from the DOI/GTN-P Deep Borehole Array on the Arctic Slope of Alaska, 1973-2013

    Science.gov (United States)

    Clow, Gary D.

    2014-01-01

    A homogeneous set of temperature measurements obtained from the DOI/GTN-P Deep Borehole Array between 1973 and 2013 is presented; DOI/GTN-P is the US Department of the Interior contribution to the Global Terrestrial Network for Permafrost (GTN-P). The 23-element array is located on the Arctic Slope of

  15. Benthic Community Structure and Sediment Geochemical Properties at Hydrocarbon Seeps Along the Continental Slope of the Western North Atlantic

    Science.gov (United States)

    Demopoulos, A. W.; Bourque, J. R.; Brooke, S.

    2015-12-01

    Hydrocarbon seeps support distinct benthic communities capable of utilizing reduced chemical compounds for nutrition. In recent years, methane seepage has been increasingly documented along the continental slope of the U.S. Atlantic margin. In 2012 and 2013, two seeps were investigated in this region: a shallow site near Baltimore Canyon (410-450 m) and a deep site near Norfolk Canyon (1600 m). Both sites contain extensive mussel beds and microbial mats. Sediment cores and grab samples were collected to quantify the abundance, diversity, and community structure of benthic macrofauna (>300 mm) in relationship to the associated sediment environment (organic carbon and nitrogen, stable isotopes 13C and 15N, grain size, and depth) of mussel beds, mats, and slope habitats. Macrofaunal densities in microbial mats were four times greater than those present in mussel beds and slope sediments. Macrofaunal communities were distinctly different both between depths and among habitat types. Specifically, microbial mat sediments were dominated by the annelid families Dorvilleidae, Capitellidae, and Tubificidae, while mussel habitats had higher proportions of crustaceans. Diversity was lower in Baltimore microbial mat habitats, but higher in mussel and slope sediments compared to Norfolk seep habitats found at deeper depths. Multivariate statistical analysis identified sediment carbon:nitrogen (C:N) ratios and 13C values as important variables for structuring the macrofaunal communities. Higher C:N ratios were present within microbial mat habitats and depleted 13C values occurred in sediments adjacent to mussel beds found in Norfolk Canyon seeps. Differences in the quality and source of organic matter present in the seep habitats are known to be important drivers in macrofaunal community structure and associated food webs. The multivariate analysis provides new insight into the relative importance of the seep sediment quality in supporting dense macrofaunal communities compared

  16. Assessment of primary production and optical variability in shelf and slope waters near Cape Hatteras, North Carolina. Final project report

    Energy Technology Data Exchange (ETDEWEB)

    Redalje, Donald G.; Lohrenz, Stevern E.

    2001-02-12

    In this project we determined primary production and optical variability in the shelf and slope waters off of Cape Hatteras, N.C. These processes were addressed in conjunction with other Ocean Margins Program investigators, during the Spring Transition period and during Summer. We found that there were significant differences in measured parameters between Spring and Summer, enabling us to develop seasonally specific carbon production and ecosystem models as well as seasonal and regional algorithm improvements for use in remote sensing applications.

  17. Association of Syscenus infelix (Crustacea: Isopoda: Aegidae) with benthopelagic rattail fishes, Nezumia spp. (Macrouridae), along the western North Atlantic continental slope

    Science.gov (United States)

    Ross, S.W.; Sulak, K.J.; Munroe, T.A.

    2001-01-01

    During submersible surveys along the continental slope (summers of 1991 and 1992, 184-847 m) between False Cape, Virginia, and Cape Hatteras, North Carolina, USA, we observed the aegid isopod, Syscenus infelix Harger, attached to the macrourid Nezumia bairdii (Goode and Bean). This is the first report of S. infelix attached to fishes in the western North Atlantic. The association of this blind isopod with its host appears species specific. The large, conspicuous isopod always attached to a fish in the same location, the dorsal midline, immediately behind the first dorsal fin. Attachment appears to be long term, with the isopod forming a characteristic scar consisting of a distinct discolored oval depression with seven small, dark impressions that coalesce as the fish grows. Only one S. infelix was found on each host fish. The isopod occurred on 23.7% of N. bairdii observed from submersible on the middle continental slope off Virginia and North Carolina, compared with 16.6% of 1236 museum specimens of the same species (based on inspection for scars) collected at latitudes 26??-64??N. Prevalence of the fish-isopod association was not correlated with depth or latitude. We also found identical scars on preserved specimens of N. aequalis (2.6% of 660 specimens), N. sclerorhynchus (1.2% of 86 specimens), and N. suilla (14.3% of 7 specimens), mostly from areas outside the range of N. bairdii. No scars were found on museum specimens of N. atlantica (n = 27), N. cyrano (n = 57), or N. longebarbata (n = 7). The low incidence of isopod attachment on these species suggests that N. bairdii is the preferred host. Infestation by the isopod appears to result in erosion of host fish scales and tissue. We propose that S. infelix is an obligate associate of its host fish and should be considered parasitic.

  18. Hazard Analysis and Disaster Preparedness in the Fairbanks North Star Borough, Alaska using Hazard Simulations, GIS, and Network Analysis

    Science.gov (United States)

    Schaefer, K.; Prakash, A.; Witte, W.

    2011-12-01

    The Fairbanks North Star Borough (FNSB) lies in interior Alaska, an area that is dominated by semiarid, boreal forest climate. FNSB frequently witnesses flooding events, wild land fires, earthquakes, extreme winter storms and other natural and man-made hazards. Being a large 19,065 km2 area, with a population of approximately 97,000 residents, providing emergency services to residents in a timely manner is a challenge. With only four highways going in and out of the borough, and only two of those leading to another city, most residents do not have quick access to a main road. Should a major disaster occur and block one of the two highways, options for evacuating or getting supplies to the area quickly dwindle. We present the design of a Geographic Information System (GIS) and network analysis based decision support tool that we have created for planning and emergency response. This tool will be used by Emergency Service (Fire/EMS), Emergency Management, Hazardous Materials Team, and Law Enforcement Agencies within FNSB to prepare and respond to a variety of potential disasters. The GIS combines available road and address networks from different FNSB agencies with the 2010 census data. We used ESRI's ArcGIS and FEMA's HAZUS-MH software to run multiple disaster scenarios and create several evacuation and response plans. Network analysis resulted in determining response time and classifying the borough by response times to facilitate allocation of emergency resources. The resulting GIS database can be used by any responding agency in FNSB to determine possible evacuation routes, where to open evacuation centers, placement of resources, and emergency response times. We developed a specific emergency response plan for three common scenarios: (i) major wildfire threatening Fairbanks, (ii) a major earthquake, (iii) loss of power during flooding in a flood-prone area. We also combined the network analysis results with high resolution imagery and elevation data to determine

  19. l680bs.m77t - MGD77 data file for Geophysical data from field activity L-6-80-BS in North Bering Sea, Alaska from 07/08/1980 to 07/28/1980

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Single-beam bathymetry, gravity, and magnetic data along with DGPS navigation data was collected as part of field activity L-6-80-BS in North Bering Sea, Alaska from...

  20. l1081na.m77t - MGD77 data file for Geophysical data from field activity L-10-81-AA in North Aleutians, Alaska from 08/16/1981 to 08/23/1981

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Single-beam bathymetry data along with DGPS navigation data was collected as part of field activity L-10-81-AA in North Aleutians, Alaska from 08/16/1981 to...

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

    Science.gov (United States)

    Falkowski, Sarah; Enkelmann, Eva; Ehlers, Todd

    2016-04-01

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

  2. Effect of cropland management and slope position on soil organic carbon pool at the North Appalachian Experimental Watersheds

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Yueli; Lal, Rattan; Owens, Lloyd; Izaurralde, R Cesar C.; Post, W M.; Hothem, Daniel

    2002-12-01

    Soil organic matter is strongly related to soil type, landscape morphology, and soil and crop management practices. Therefore, long-term (15-36-years) effects of six cropland management systems on soil organic carbon (SOC) pool in 0-30 cm depth were studied for the period of 1939-1999 at the North Appalachian Experimental Watersheds (<3 ha, Dystric Cambisol, Haplic Luvisol, and Haplic Alisol) near Coshocton, OH, USA. Six management treatments were: (1) no tillage continuous corn with NPK (NC); (2) no tillage continuous corn with NPK and manure (NTC-M); (3) no tillage corn?soybean rotation (NTR); (4) chisel tillage corn?soybean rotation (CTR); (5) moldboard tillage with corn?wheat?meadow?meadow rotation with improved practices (MTR-I); (6) moldboard tillage with corn?wheat?meadow?meadow rotation with prevalent practices (MTR-P). The SOC pool ranged from 24.5Mgha?1 in the 32-years moldboard tillage corn (Zea mays L.)?wheat (Triticum aestivum L.)?meadow?meadow rotation with straight row farming and annual application of fertilizer (N:P:K = 5:9:17) of 56?112 kg ha?1 and cattle (Bos taurus) manure of 9Mg ha?1 as the prevalent system (MTR-P) to 65.5Mgha?1 in the 36-years no tillage continuous corn with contour row farming and annual application of 170?225 kgNha?1 and appropriate amounts of P and K, and 6?11Mgha?1 of cattle manure as the improved system (NTC-M).

  3. Interior Alaska Bouguer Gravity Anomaly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A 1 kilometer Complete Bouguer Anomaly gravity grid of interior Alaska. All grid cells within the rectangular data area (from 61 to 66 degrees North latitude and...

  4. Soil Sampling to Demonstrate Compliance with Department of Energy Radiological Clearance Requirements for the McGee Ranch-Riverlands and North Slope Units of the Hanford Reach National Monument

    Energy Technology Data Exchange (ETDEWEB)

    Fritz, Brad G.; Dirkes, Roger L.; Napier, Bruce A.

    2007-09-21

    The Hanford Reach National Monument (HRNM) was created by presidential proclamation in 2000. It is located along the Columbia River in south central Washington and consists of five distinct units. The McGee Ranch-Riverlands and the North Slope units are addressed in this report. North Slope refers to two of the HRNM units: the Saddle Mountain Unit and the Wahluke Slope Unit. The Saddle Mountain and Wahluke Slope Units are located north of the Columbia River, while the McGee Ranch-Riverlands Unit is located south of the Columbia River and north and west of Washington State Highway 24. To fulfill internal U.S. Department of Energy (DOE) requirements prior to any radiological clearance of land, the DOE must evaluate the potential for residual radioactive contamination on this land and determine compliance with the requirements of DOE Order 5400.5. Authorized limits for residual radioactive contamination were developed based on the DOE annual exposure limit to the public (100 mrem) using future potential land-use scenarios. The DOE Office of Environmental Management approved these authorized limits on March 1, 2004. Historical soil monitoring conducted on and around the HRNM indicated soil concentrations of radionuclides were well below the authorized limits (Fritz et al. 2003). However, the historical sampling was done at a limited number of sampling locations. Therefore, additional soil sampling was conducted to determine if the concentrations of radionuclides in soil on the McGee Ranch-Riverlands and North Slope units were below the authorized limits. Sixty-seven soil samples were collected from the McGee Ranch-Riverlands and North Slope units. A software package (Visual Sample Plan) was used to plan the collection to assure an adequate number of samples were collected. The number of samples necessary to decide with a high level of confidence (99%) that the soil concentrations of radionuclides on the North Slope and McGee Ranch-Riverlands units did not exceed the

  5. Feature Variations of Plant Functional Traits and Environmental Factor in South-and North-Facing Slope%阴阳坡植物功能性状与环境因子的变化特征

    Institute of Scientific and Technical Information of China (English)

    刘旻霞; 马建祖

    2013-01-01

    Plant traits link environmental factors, individuals and ecosystem structure and functions as plants respond and adapt to the environment. The characteristics of plant functional traits and variation law by environmental changes are important to understand plant community composition and adaptation mechanism in different environmental gradients. Plant functional traits and soil element contents were studied along north-facing slope to south-facing slope in the alpine meadow. The results showed that the variation of the soil water content, the total phosphorus and soil organic carbon in different habitats from south-facing slope to north-facing slope were in the sequence of south-facing slopenorth-facing slope. The plant functional traits of leaf phosphorus content (LPC) and specific leaf area (SLA) of the habitat from south-facing slope to north-facing slope were in the order of north-facing slope>south-facing slope, except that leaf nitrogen content, but leaf N : P ratio of north-facing slope were significantly less than the south-facing slope. Plant functional traits with the aspect of regular changes reflected the environmental filtering effects in the process of vegetation community forming in an alpine meadow. Correlation analysis showed that soil water content and soil nutrients were the important factors affecting plant functional traits in south-facing slope to north-facing slope, and soil water content was the dominant factor.%植物性状反映了植物对生长环境的响应和适应,将环境、植物个体和生态系统结构、过程与功能联系起来,研究植物功能性状特征及其随坡向梯度的变化规律,对认识不同环境梯度下植物群落的形成及其对环境的适应机制具有重要意义.以高寒草甸植被为研究对象,测定了阴阳坡植物功能性状和土壤元素含量.结果表明:阳坡阴坡不同生境的土壤含水量、土壤全磷含量和有机质含量的变化均为阳坡<阴坡;土壤全氮

  6. Trophic ecology of Lampanyctus crocodilus on north-west Mediterranean Sea slopes in relation to reproductive cycle and environmental variables.

    Science.gov (United States)

    Fanelli, E; Papiol, V; Cartes, J E; Rodriguez-Romeu, O

    2014-06-01

    This study examined the population structure, reproductive cycle and feeding pattern of the lanternfish Lampanyctus crocodilus in the Balearic Basin (north-west Mediterranean Sea) from a depth of 450 to 1800 m and at a seasonal scale. Juveniles were mainly located at shallower depths, but also at deepest stations in autumn, while adults mostly inhabited intermediate depths with their centre of population density (CPD) located at 800-1000 m of depth. The migration of adults to deeper depths was detected in late summer to autumn, probably linked to the occurrence of nepheloid layers at c. 1200 m, which in turn enhances the biomass of the zooplankton prey. The diet was mainly based on euphausiids and mysids, with marked seasonal variations both on the upper (450-800 m) and lower (1000-1800 m), where suprabenthic gammariids and pelagic decapods were also dominant. Stomach fullness increased from winter to autumn on the US, while it had a maximum in spring on the LS, in parallel with high consumption of gelatinous zooplankton, which is probably more available after the phytoplankton bloom in late winter. Reproduction occurred in winter, confirmed by the higher percentage of mature females and high gonadosomatic indices (I(G)) at both depth ranges. Hepatosomatic indices (I(H)) showed an inverse trend to I(G) on the US, except in autumn, and was almost parallel on the LS, probably attributable to the migration of adults, which determined different temporal schemes in energy use and storage for reproduction on the US v. LS. Consistent with the different patterns observed at the two depth ranges, environmental drivers of fullness (i.e. feeding intensity) and I(G) (as a proxy of reproductive cycle) differed on the US and LS. The biomass of mysids and euphausiids was the greatest explanatory variables of fullness on the US and LS, pointing to the increasing feeding intensity when a resource was more available. I(H) also explained fullness, suggesting that greater

  7. Integrating GIS-based geologic mapping, LiDAR-based lineament analysis and site specific rock slope data to delineate a zone of existing and potential rock slope instability located along the grandfather mountain window-Linville Falls shear zone contact, Southern Appalachian Mountains, Watauga County, North Carolina

    Science.gov (United States)

    Gillon, K.A.; Wooten, R.M.; Latham, R.L.; Witt, A.W.; Douglas, T.J.; Bauer, J.B.; Fuemmeler, S.J.

    2009-01-01

    Landslide hazard maps of Watauga County identify >2200 landslides, model debris flow susceptibility, and evaluate a 14km x 0.5km zone of existing and potential rock slope instability (ZEPRSI) near the Town of Boone. The ZEPRSI encompasses west-northwest trending (WNWT) topographic ridges where 14 active/past-active rock/weathered rock slides occur mainly in rocks of the Grandfather Mountain Window (GMW). The north side of this ridgeline is the GMW / Linville Falls Fault (LFF) contact. Sheared rocks of the Linville Falls Shear Zone (LFSZ) occur along the ridge and locally in the valley north of the contact. The valley is underlain principally by layered granitic gneiss comprising the Linville Falls/Beech Mountain/Stone Mountain Thrust Sheet. The integration of ArcGIS??? - format digital geologic and lineament mapping on a 6m LiDAR (Light Detecting and Ranging) digital elevation model (DEM) base, and kinematic analyses of site specific rock slope data (e.g., presence and degree of ductile and brittle deformation fabrics, rock type, rock weathering state) indicate: WNWT lineaments are expressions of a regionally extensive zone of fractures and faults; and ZEPRSI rock slope failures concentrate along excavated, north-facing LFF/LFSZ slopes where brittle fabrics overprint older metamorphic foliations, and other fractures create side and back release surfaces. Copyright 2009 ARMA, American Rock Mechanics Association.

  8. Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Barometric pressure sensor, Carbon dioxide (CO2) gas analyzer and other instruments from NOAA Ship OSCAR DYSON in the Bering Sea, Gulf of Alaska and North Pacific Ocean from 2014-03-03 to 2014-08-13 (NCEI Accession 0144980)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0144980 includes Surface underway data collected from NOAA Ship OSCAR DYSON in the Bering Sea, Gulf of Alaska and North Pacific Ocean from 2014-03-03...

  9. Wind wave spectra and meteorological data from FIXED PLATFORMS from the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska, Great Lakes, and other locations from 2002-06-01 to 2002-06-30 (NCEI Accession 0000771)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Wind wave spectra and meteorological data were collected from FIXED PLATFORMS in the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska,...

  10. Wind wave spectra and meteorological data from FIXED PLATFORMS from the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska, Great Lakes, and other locations from 2002-07-01 to 2002-07-31 (NCEI Accession 0000773)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Wind wave spectra and meteorological data were collected from FIXED PLATFORMS in the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska,...

  11. Wind wave spectra and meteorological data from FIXED PLATFORMS from the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska, Great Lakes, and other locations from 01 November 2002 to 31 November 2002 (NCEI Accession 0000835)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Wind wave spectra and meteorological data were collected from FIXED PLATFORMS in the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska,...

  12. Wind wave spectra and meteorological data from FIXED PLATFORMS from the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska, Great Lakes, and other locations from 01 September 2002 to 31 September 2002 (NODC Accession 0000799)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Wind wave spectra and meteorological data were collected from FIXED PLATFORMS in the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska,...

  13. Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from NOAA Ship DISCOVERER in the Gulf of Alaska and North Pacific Ocean from 1991-03-07 to 1991-04-07 (NODC Accession 0115175)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0115175 includes chemical, discrete sample, physical and profile data collected from NOAA Ship DISCOVERER in the Gulf of Alaska and North Pacific...

  14. Wind wave spectra and meteorological data from FIXED PLATFORMS from the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska, Great Lakes, and other locations from 2002-05-01 to 2002-05-31 (NODC Accession 0000752)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Wind wave spectra and meteorological data were collected from FIXED PLATFORMS in the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska,...

  15. Wind wave spectra and meteorological data from FIXED PLATFORMS from the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska, Great Lakes, and other locations from 2002-03-01 to 2002-03-31 (NCEI Accession 0000716)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Wind wave spectra and meteorological data were collected from FIXED PLATFORMS in the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska,...

  16. Wind wave spectra and meteorological data from FIXED PLATFORMS from the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska, Great Lakes, and other locations from 2002-08-01 to 2002-08-31 (NCEI Accession 0000785)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Wind wave spectra and meteorological data were collected from FIXED PLATFORMS in the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska,...

  17. Wind wave spectra and meteorological data from FIXED PLATFORMS from the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska, Great Lakes, and other locations from 2002-04-01 to 2002-04-30 (NCEI Accession 0000726)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Wind wave spectra and meteorological data were collected from FIXED PLATFORMS from the East/West coasts of US, North Pacific Ocean, Gulf of Mexico, Gulf of Alaska,...

  18. Investigating the 'Iron Hypothesis' in the North Pacific: Trans-Pacific Dust and Methanesulfonate (MSA) in the Denali Ice Core, Alaska

    Science.gov (United States)

    Saylor, P. L.; Osterberg, E. C.; Winski, D.; Ferris, D. G.; Koffman, B. G.; Kreutz, K. J.; Wake, C. P.; Campbell, S. W.

    2015-12-01

    Oceanic deposition of Asian-sourced, Iron-rich dust particulate has been linked to enhanced phytoplankton productivity in regions of the Pacific Ocean. High Nutrient Low Chlorophyll (HNLC) ocean regions, such as the North Pacific, are hypothesized to play a significant role in changing atmospheric CO­2 concentrations on glacial-interglacial timescales. Phytoplankton blooms generate methanesulfonate (MSA), an atmospheric oxidation product of dimethylsulfide (DMS) that is readily aerosolized and deposited in nearby glacial ice. In the summer of 2013, an NSF-funded team from Dartmouth College and the Universities of Maine and New Hampshire collected two 1000 year-long parallel ice cores to bedrock from the summit plateau of Mount Hunter in Denali National Park, Alaska (62.940° N, 151.088° W, 3912 m elevation). The Mt. Hunter ice core site is well situated to record changes in trans-Pacific dust flux and MSA emissions in the North Pacific. Here we investigate the history of dust flux to Denali over the last millennium using major and trace element chemistry and microparticle concentration and size distribution data from the Mt. Hunter cores. We evaluate potential controlling mechanisms on Denali dust flux including conditions at Asian dust sources (storminess, wind speed, precipitation), the strength of the Aleutian Low, and large-scale climate modes such as the El Niño-Southern Oscillation and the Pacific Decadal Oscillation. We also evaluate the Mt. Hunter record for relationships between dust flux and MSA concentrations to investigate whether dust fertilization enhanced North Pacific phytoplankton production over the past 1000 years. Future work will create a composite North Pacific dust record using new and existing Mt. Logan ice core records to evaluate these relationships over the entire Holocene.

  19. Alaska Center for Climate Assessment and Policy: Partnering with Decision-Makers in Climate Change Adaptation

    Science.gov (United States)

    White, D.; Trainor, S.; Walsh, J.; Gerlach, C.

    2008-12-01

    The Alaska Center for Climate Assessment and Policy (ACCAP; www.uaf.edu/accap) is one of several, NOAA funded, Regional Integrated Science and Policy (RISA) programs nation-wide (http://www.climate.noaa.gov/cpo_pa/risa/). Our mission is to assess the socio-economic and biophysical impacts of climate variability in Alaska, make this information available to local and regional decision-makers, and improve the ability of Alaskans to adapt to a changing climate. We partner with the University of Alaska?s Scenario Network for Alaska Planning (SNAP; http://www.snap.uaf.edu/), state and local government, state and federal agencies, industry, and non-profit organizations to communicate accurate and up-to-date climate science and assist in formulating adaptation and mitigation plans. ACCAP and SNAP scientists are members of the Governor?s Climate Change Sub-Cabinet Adaptation and Mitigation Advisory and Technical Working Groups (http://www.climatechange.alaska.gov/), and apply their scientific expertise to provide down-scaled, state-wide maps of temperature and precipitation projections for these groups. An ACCAP scientist also serves as co-chair for the Fairbanks North Star Borough Climate Change Task Force, assisting this group as they work through the five-step model for climate change planning put forward by the International Council for Local Environmental Initiatives (http://www.investfairbanks.com/Taskforces/climate.php). ACCAP scientists work closely with federal resource managers in on a range of projects including: partnering with the U.S. Fish and Wildlife Service to analyze hydrologic changes associated with climate change and related ecological impacts and wildlife management and development issues on Alaska?s North Slope; partnering with members of the Alaska Interagency Wildland Fire Coordinating Group in statistical modeling to predict seasonal wildfire activity and coordinate fire suppression resources state-wide; and working with Alaska Native Elders and

  20. Backpacking of the north slope

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report describes a backpacking trip on Arctic National Wildlife Refuge in July of 1970. Weather conditions, wildlife observations, and a description of the...

  1. Slope runoff study in situ using rainfall simulator in mountainous area of North China%华北山区坡地产流规律研究

    Institute of Scientific and Technical Information of China (English)

    于静洁; 杨聪; 刘昌明; 宋献方; 胡珊珊; 李发东; 唐常源

    2009-01-01

    Simulated rainfall is a valid tool to examine the runoff generation on the slope. 13 simulated rainfall experiments with different rainfall intensities and durations are completed in a 5 m ×10 m experimental plot in mountainous area of North China. Simultaneously, rainfall, surface runoff, soil-layer flow, mantel-layer flow and soil moisture are monitored respectively. From the results, it is found that the hydrographs in all layers have the characteristics of rapid rise and fall. The recessions of surface flow and soil-layer flow are much faster than that of mantel-layer flow. Surface flow, the main contributor, makes up more than 60% of the total runoff in the study area. It even exceeds 90% in the cases of high intensity rainfall events. Runoff coefficient (ratio of total runoff to rainfall amount) is mainly influenced by rainfall amount, rainfall intensity and antecedent soil moisture, and the relationship can be well ex-pressed by a multiple linear regression function a = 0.002P + 0.1821 + 4.88Wa - 0.821. The relation between the rainfall intensity and the lag time of three flows (surface runoff, soil-layer flow and mantel-layer flow) is shown to be exponential. Then, the result also shows that the recession constant is 0.75 for surface runoff, is 0.94 for soil-layer and mantel-layer flow in this area. In this study area, the dominant infiltration excess runoff is simulated by Horton model. About 0.10 mm/min percolation is observed under the condition of different rainfall intensities, therefore the value is regarded as the steady infiltration rate of the study area.

  2. Distribution and productivity of fall staging snow geese on the Arctic National Wildlife Refuge, Alaska, and North Slope, Yukon Territory: Results of 1980 surveys

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Population and distribution and productivity of snow geese from the Banks Island. Population that stage in fall on the arctic coastal plain between Barter Island,...

  3. Examination of core samples from the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope: Effects of retrieval and preservation

    Science.gov (United States)

    Kneafsey, T.J.; Lu, H.; Winters, W.; Boswell, R.; Hunter, R.; Collett, T.S.

    2011-01-01

    Collecting and preserving undamaged core samples containing gas hydrates from depth is difficult because of the pressure and temperature changes encountered upon retrieval. Hydrate-bearing core samples were collected at the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well in February 2007. Coring was performed while using a custom oil-based drilling mud, and the cores were retrieved by a wireline. The samples were characterized and subsampled at the surface under ambient winter arctic conditions. Samples thought to be hydrate bearing were preserved either by immersion in liquid nitrogen (LN), or by storage under methane pressure at ambient arctic conditions, and later depressurized and immersed in LN. Eleven core samples from hydrate-bearing zones were scanned using x-ray computed tomography to examine core structure and homogeneity. Features observed include radial fractures, spalling-type fractures, and reduced density near the periphery. These features were induced during sample collection, handling, and preservation. Isotopic analysis of the methane from hydrate in an initially LN-preserved core and a pressure-preserved core indicate that secondary hydrate formation occurred throughout the pressurized core, whereas none occurred in the LN-preserved core, however no hydrate was found near the periphery of the LN-preserved core. To replicate some aspects of the preservation methods, natural and laboratory-made saturated porous media samples were frozen in a variety of ways, with radial fractures observed in some LN-frozen sands, and needle-like ice crystals forming in slowly frozen clay-rich sediments. Suggestions for hydrate-bearing core preservation are presented.

  4. Regional long-term production modeling from a single well test, Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope

    Science.gov (United States)

    Anderson, B.J.; Kurihara, M.; White, M.D.; Moridis, G.J.; Wilson, S.J.; Pooladi-Darvish, M.; Gaddipati, M.; Masuda, Y.; Collett, T.S.; Hunter, R.B.; Narita, H.; Rose, K.; Boswell, R.

    2011-01-01

    Following the results from the open-hole formation pressure response test in the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well (Mount Elbert well) using Schlumberger's Modular Dynamics Formation Tester (MDT) wireline tool, the International Methane Hydrate Reservoir Simulator Code Comparison project performed long-term reservoir simulations on three different model reservoirs. These descriptions were based on 1) the Mount Elbert gas hydrate accumulation as delineated by an extensive history-matching exercise, 2) an estimation of the hydrate accumulation near the Prudhoe Bay L-pad, and 3) a reservoir that would be down-dip of the Prudhoe Bay L-pad and therefore warmer and deeper. All of these simulations were based, in part, on the results of the MDT results from the Mount Elbert Well. The comparison group's consensus value for the initial permeability of the hydrate-filled reservoir (k = 0.12 mD) and the permeability model based on the MDT history match were used as the basis for subsequent simulations on the three regional scenarios. The simulation results of the five different simulation codes, CMG STARS, HydrateResSim, MH-21 HYDRES, STOMP-HYD, and TOUGH+HYDRATE exhibit good qualitative agreement and the variability of potential methane production rates from gas hydrate reservoirs is illustrated. As expected, the predicted methane production rate increased with increasing in situ reservoir temperature; however, a significant delay in the onset of rapid hydrate dissociation is observed for a cold, homogeneous reservoir and it is found to be repeatable. The inclusion of reservoir heterogeneity in the description of this cold reservoir is shown to eliminate this delayed production. Overall, simulations utilized detailed information collected across the Mount Elbert reservoir either obtained or determined from geophysical well logs, including thickness (37 ft), porosity (35%), hydrate saturation (65%), intrinsic permeability (1000 mD), pore water salinity (5 ppt), and formation temperature (3.3-3.9 ??C). This paper presents the approach and results of extrapolating regional forward production modeling from history-matching efforts on the results from a single well test. ?? 2010 Elsevier Ltd.

  5. Heavy oil recovery process: Conceptual engineering of a downhole methanator and preliminary estimate of facilities cost for application to North Slope Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Gondouin, M.

    1991-10-31

    The West Sak (Upper Cretaceous) sands, overlaying the Kuparuk field, would rank among the largest known oil fields in the US, but technical difficulties have so far prevented its commercial exploitation. Steam injection is the most successful and the most commonly-used method of heavy oil recovery, but its application to the West Sak presents major problems. Such difficulties may be overcome by using a novel approach, in which steam is generated downhole in a catalytic Methanator, from Syngas made at the surface from endothermic reactions (Table 1). The Methanator effluent, containing steam and soluble gases resulting from exothermic reactions (Table 1), is cyclically injected into the reservoir by means of a horizontal drainhole while hot produced fluids flow form a second drainhole into a central production tubing. The downhole reactor feed and BFW flow downward to two concentric tubings. The large-diameter casing required to house the downhole reactor assembly is filled above it with Arctic Pack mud, or crude oil, to further reduce heat leaks. A quantitative analysis of this production scheme for the West Sak required a preliminary engineering of the downhole and surface facilities and a tentative forecast of well production rates. The results, based on published information on the West Sak, have been used to estimate the cost of these facilities, per daily barrel of oil produced. A preliminary economic analysis and conclusions are presented together with an outline of future work. Economic and regulatory conditions which would make this approach viable are discussed. 28 figs.

  6. Environmental Sensitivity Index (ESI) Atlas: North Slope, Alaska, Volume 1, geographic information systems data, Volume 2, maps in portable document format (NODC Accession 0014928)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — ESI data characterize the marine and coastal environments and wildlife by their sensitivity to spilled oil. The ESI data include information for three main...

  7. University of Alaska Coastal Marine Institute annual report number 5, fiscal year 1998

    Energy Technology Data Exchange (ETDEWEB)

    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.

  8. Ship Sensor Observations for Islands in the Stream 2002 - Exploration of Outer Shelf and Slope Habitats off the Coast of North Carolina - Office of Ocean Exploration

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hourly measurements made by selected ship sensors on the R/V Seward Johnson during the 2002 "Islands in the Stream - Exploration of Outer Shelf and Slope Habitats...

  9. Characteristics of Vertical Distribution of Vegetation Community in the North Slope of Qilian Mountain%祁连山北坡植被群落垂直分布特征

    Institute of Scientific and Technical Information of China (English)

    易玉媛; 王红义

    2013-01-01

    In order to explore the characteristics of distribution of vegetation community in vertical climatic zones in the north slope of Qilian Mountain ,adopting combined methods of sample survey & file data compilation ,gradient characteristic of vegetation community was discussed according to changes of altitude .Result shows that :(1) it has 84 families ,399 genera & 1 044 species in the north slope of Qilian mountain .These first ten families are Asterace-ae ,Poaceae ,Ranunculaceae ,Rosaceae ,Leguminosae ,Chenopodiaceae ,Umbelliferae ,Lamiaceae ,Caryophyllaceae ,Cru-ciferae ,which accounted for 54 .89% of all kinds of genera and species in Qilian Mountains .(2) according to altitude gradient ,five major vegetation zones and 16 typical vegetation communities were presented in the north slope of Qil-ian Mountain .%为了探索祁连山北坡垂直气候带植被群落分布特征,采用样地调查和档案资料整理相结合的方法,按照海拔梯度变化格局研究植被群落的梯度特征,结果表明:(1)祁连山北坡植物分属84科399属1044种,从大到小依次为菊科、禾本科、毛茛科、蔷薇科、豆科、藜科、伞形科、唇形科、石竹科、十字花科,这前10个科的属和种均占祁连山植物属和种的54.89%;(2)沿海拔梯度,祁连山北坡植被群落呈现5大植被带和16个主要的、典型的植被群落。

  10. Major solutes, metals, and alkylated aromatic compounds in high-latitude maritime snowpacks near the trans-Alaska pipeline terminal, Valdez, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Bower, Jonathan P; Hood, Eran; Hoferkamp, Lisa A [Department of Natural Sciences, University of Alaska Southeast, 11120 Glacier Highway, Juneau, AK 99801 (United States)], E-mail: jpbower@ucdavis.edu

    2008-10-15

    The chemical constituents within a snowpack can provide information about the atmosphere through which the snow was deposited. Valdez is located in south-central Alaska and has a high-latitude maritime climate, with annual snowfall typically exceeding 8 m within the city limits. Valdez is also the termination point of the trans-Alaska pipeline system, where tankers are loaded with crude oil from the North Slope of Alaska. Integrated samples of the top 1 m of snow were collected at seven sites near Valdez and analyzed for major solutes, lead, and alkylated aromatic compounds, in particular benzene, toluene, ethylbenzene, and xylene (BTEX). For comparison, sites were also sampled near Juneau, Alaska, which has a similar climate but no petroleum transport infrastructure. Major solute chemistry at all sites was dominated by chloride and was consistent with a marine air mass source of ions in precipitation. Sulfate levels in Valdez were typically on the order of 10 {mu}eq l{sup -1} and significantly higher than found in Juneau snow. Other major solute levels were low in Valdez and Juneau. Lead levels were below detection limits for all sites, with the exception of trace concentrations (<0.4 {mu}g l{sup -1}) reported at two Valdez locations. Alkylated organics were present at all Valdez locations, at levels similar to those documented previously in urban locations. No alkylated organics were detected in Juneau snowpacks.

  11. Central Gulf of Alaska Rockfish Permit Program

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The North Pacific Fishery Management Council adopted the Central Gulf of Alaska Rockfish Program (Rockfish Program) on June 14, 2010, to replace the expiring Pilot...

  12. Kensington Mine Area Baseline Contaminants Study, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Hardrock mining for gold and other metals is proposed for the Kensington Mine, located on Lynn Canal in Southeast Alaska, approximately 45 miles north of Juneau. The...

  13. Study on frost damage control measures for permanent slope of a hydroelectric station in North Xinjiang%北疆某水电站永久边坡冻害治理措施研究

    Institute of Scientific and Technical Information of China (English)

    孙根民

    2012-01-01

    A water control project in Xinjiang is located in the alpine region of the North Xinjiang; of which the permanent slope of the ground powerhouse for the hydropower plant is under the impact of frost damage due to the unsmooth seepage water drainage therein, i. e. the slope surface is even covered by the ice with the thickness up to 1 m during winter, and then a Larger damage is made on both Uie slope and the ground concrete nearby. Through the relevant study, the control measures of adding drainage adits, densifying drain-holes and making heat-insulation for drainage pipelines are adopted; thereby, the ice damage is eliminated at last.%新疆某水利工程地处新疆北部严寒地区,水电站地面厂房永久边坡因排水不畅受冻害影响,冬季坡面冰盖厚度达2 m以上,并对边坡及地面混凝土造成较大破坏.经研究,采用了增设排水洞,加密排水孔,并对排水管进行保温等治理措施,最终消除了冰害影响.

  14. Seismology Outreach in Alaska

    Science.gov (United States)

    Gardine, L.; Tape, C.; West, M. E.

    2014-12-01

    Despite residing in a state with 75% of North American earthquakes and three of the top 15 ever recorded, most Alaskans have limited knowledge about the science of earthquakes. To many, earthquakes are just part of everyday life, and to others, they are barely noticed until a large event happens, and often ignored even then. Alaskans are rugged, resilient people with both strong independence and tight community bonds. Rural villages in Alaska, most of which are inaccessible by road, are underrepresented in outreach efforts. Their remote locations and difficulty of access make outreach fiscally challenging. Teacher retention and small student bodies limit exposure to science and hinder student success in college. The arrival of EarthScope's Transportable Array, the 50th anniversary of the Great Alaska Earthquake, targeted projects with large outreach components, and increased community interest in earthquake knowledge have provided opportunities to spread information across Alaska. We have found that performing hands-on demonstrations, identifying seismological relevance toward career opportunities in Alaska (such as natural resource exploration), and engaging residents through place-based experience have increased the public's interest and awareness of our active home.

  15. Multi-year Estimates of Methane Fluxes in Alaska from an Atmospheric Inverse Model

    Science.gov (United States)

    Miller, S. M.; Commane, R.; Chang, R. Y. W.; Miller, C. E.; Michalak, A. M.; Dinardo, S. J.; Dlugokencky, E. J.; Hartery, S.; Karion, A.; Lindaas, J.; Sweeney, C.; Wofsy, S. C.

    2015-12-01

    We estimate methane fluxes across Alaska over a multi-year period using observations from a three-year aircraft campaign, the Carbon Arctic Reservoirs Vulnerability Experiment (CARVE). Existing estimates of methane from Alaska and other Arctic regions disagree in both magnitude and distribution, and before the CARVE campaign, atmospheric observations in the region were sparse. We combine these observations with an atmospheric particle trajectory model and a geostatistical inversion to estimate surface fluxes at the model grid scale. We first use this framework to estimate the spatial distribution of methane fluxes across the state. We find the largest fluxes in the south-east and North Slope regions of Alaska. This distribution is consistent with several estimates of wetland extent but contrasts with the distribution in most existing flux models. These flux models concentrate methane in warmer or more southerly regions of Alaska compared to the estimate presented here. This result suggests a discrepancy in how existing bottom-up models translate wetland area into methane fluxes across the state. We next use the inversion framework to explore inter-annual variability in regional-scale methane fluxes for 2012-2014. We examine the extent to which this variability correlates with weather or other environmental conditions. These results indicate the possible sensitivity of wetland fluxes to near-term variability in climate.

  16. ALASKA OIL AND GAS EXPLORATION, DEVELOPMENT, AND PERMITTING PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Richard McMahon; Robert Crandall; Chas Dense; Sean Weems

    2003-11-19

    This is the second technical report, covering the period from April 1, 2003 through September 30, 2003. This project brings together three parts of the oil exploration, development, and permitting process to form the foundation for a more fully integrated information technology infrastructure for the State of Alaska. The geo-technical component is a shared effort between the State Department of Administration and the US Department of Energy. The Alaska Oil and Gas Conservation Commission is rapidly converting high volumes of paper documents and geo-technical information to formats suitable for search and retrieval over the Internet. The permitting component is under the lead of the DNR Office of Project Management and Permitting. A web-based system will enable the public and other review participants to track permit status, submit and view comments, and obtain important project information on-line. By automating several functions of the current manual process, permit applications will be completed more quickly and accurately, and agencies will be able to complete reviews with fewer delays. Structural changes are taking place in terms of organization, statutory authority, and regulatory requirements. Geographic Information Systems are a central component to the organization of information, and the delivery of on-line services. Progress has been made to deploy the foundation system for the shared GIS based on open GIS protocols to the extent feasible. Alaska has nearly one-quarter of the nation's supply of crude oil, at least five billion barrels of proven reserves. The American Association of Petroleum Geologists report that the 1995 National Assessment identified the North Slope as having 7.4 billion barrels of technically recoverable oil and over 63 trillion cubic feet of natural gas. From these reserves, Alaska produces roughly one-fifth of the nation's daily crude oil production, or approximately one million barrels per day from over 1,800 active wells.

  17. Instabilities and deformation in the sedimentary cover on the upper slope of the southern Aquitaine continental margin, north of the Capbreton canyon (Bay of Biscay)

    OpenAIRE

    Gonthier, E; Cirac, P.; Faugeres, J; Gaudin, Mathieu; Cremer, M; Bourillet, Jean-francois

    2006-01-01

    Acoustic and core data have recently been collected on the shelf break and the upper part of the slope of the south Aquitaine continental margin. They reveal the major role played by mass-flow gravity processes in deposit erosion and redistribution, modelling of the sea-bed, and transfer of sediment toward the deep-sea. The study region is bounded in the south by the Capbreton canyon. The northern area, which shows a smooth morphology, is characterised by small-scale deformations due to sedim...

  18. Calculating Lake Morphology in the Colville River Delta, Alaska

    Science.gov (United States)

    McGraw, M.; Walker, H. J.

    2013-12-01

    The morphology and surface area of a lake can be determined using simple mathematical formulas. These formulas can be plugged into a Geographic Information System (GIS) and used to calculate the circularity, smoothness, compactness and orientation of a lake or pond in remotely sensed imagery. The calculated output can then be used to differentiate circular lakes from elongated lakes, lakes with smooth shorelines from those with complex shorelines, and lake orientation; such information can then be used to classify and quantify different types of lakes in complex environments such as river deltas. The Colville River delta is located on the North Slope of Arctic Alaska. Previous studies have classified the delta's 230,000+ lakes into five types: 1. thermokarst (thaw) lakes, 2. oriented lakes, 3. perched lakes, 4 channel lakes and 5. ice-wedge polygon ponds. This study uses 2004 aerial photography and 2011 satellite imagery to quantify the different types of lake in the delta.

  19. The Dynamics Response of Betula ermanii Population and Climate Change on Different Slopes Aspect of North Slope,Changbai Mountains%长白山北坡林线岳桦种群动态对气候变化响应的坡向分异

    Institute of Scientific and Technical Information of China (English)

    王晓东; 刘惠清

    2012-01-01

    To discover the relation between Betula ermanii population dynamics and climate change on treeline ecotone of Changbai Mountains,53 plots were selected on three different slope aspects(northeast,southeast,east slopes) through treeline ecotone on north slope of Changbai Mountains.Distributing character of the diameter-class(diameter at breast height(DBH)) structure of shrub and single-trunk forms were described by four aggregation indices.Trend analysis of distributing character was carried through by unitary linearity equations.Different reflection of the dynamics response of Betula ermanii population to climate change on different slope aspects was analyzed by stepwise regression and correlation analysis.The results are as follows:the results of trend analysis of the diameter-class distributing(slopes of equations are negative) shows the capacity expansion rate of shrub form is east slopes〉southeast slopes〉northeast slopes and that of single trunk form is northeast slopes〉east slopes〉southeast slopes.The population expansion is leapfrog and pulsatile from low to high(p〉0.01).The result of One-way ANOVA displays that daily mean temperature on three slopes are significant differences(p〈0.05) and the temperature change has synchronism.The results of correlation analysis between annual stem recruitment of Betula ermanii population and 14 ecological preferences of air temperature(1953-2008) show that the different response of population dynamics to climate change caused by different temperature on three slopes.The difference of climate change lead to different expansion of Betula ermanii population on different positions.%选取长白山北坡岳桦(Betula ermanii)苔原交错带3个不同坡向(东北坡、东南坡、东坡)的岳桦径级结构为研究对象,分析坡向在岳桦种群动态与气候变化之间关系的异同。结果表明:三坡向的岳桦种群扩张和气温高低存在明显差异。14个

  20. The Influence of Fold and Fracture Development on Reservoir Behavior of the Lisburne Group of Northern Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, Wesley K.; Hanks, Catherine L.; Whalen, Michael T.; Jensen1, Jerry; Shackleton, J. Ryan; Jadamec, Margarete A.; McGee, Michelle M.; Karpov1, Alexandre V.

    2001-07-23

    The Carboniferous Lisburne Group is a major carbonate reservoir unit in northern Alaska. The lisburne is detachment folded where it is exposed throughout the northeastern Brooks Range, but is relatively underformed in areas of current production in the subsurface of the North Slope. The objectives of this study are to develop a better understanding of four major aspects of the Lisburne: (1) The geometry and kinematics of detachment folds and their truncation by thrust faults, (2) The influence of folding on fracture patterns, (3) The influence of deformation on fluid flow, and (4) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics.

  1. Documentation only - no data type tows data collected in the Gulf of Alaska and North Pacific Ocean on the CHARTER/FISHING BOATS cruises GP0108, GP0207-01 and GP0207-02 as part of the NEP project from 2001-07-29 to 2002-08-06 (NODC Accession 0115275)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0115275 includes tows data collected aboard the CHARTER/FISHING BOATS during cruises GP0108, GP0207-01 and GP0207-02 in the Gulf of Alaska and North...

  2. ElevationSlope_SLOPE1M2009

    Data.gov (United States)

    Vermont Center for Geographic Information — This metadata applies to the following collection area(s): Barre Montpelier 2009 1m and related SLOPE datasets. Created using ArcGIS "SLOPE" command to produce...

  3. ElevationSlope_SLOPE2M

    Data.gov (United States)

    Vermont Center for Geographic Information — This metadata applies to the following collection area(s): Bennington County 2012 2.0m and related SLOPE datasets. Created using ArcGIS "SLOPE" command to produce...

  4. ElevationSlope_SLOPE1M2005

    Data.gov (United States)

    Vermont Center for Geographic Information — This metadata applies to the following collection area(s): Essex County 2005 1m and related SLOPE datasets. Created using ArcGIS "SLOPE" command to produce change in...

  5. ElevationSlope_SLOPE1M2010

    Data.gov (United States)

    Vermont Center for Geographic Information — This metadata applies to the following collection area(s): Bennington Floodplain 2010 1m and related SLOPE datasets. Created using ArcGIS "SLOPE" command to produce...

  6. ElevationSlope_SLOPE1M2007

    Data.gov (United States)

    Vermont Center for Geographic Information — This metadata applies to the following collection area(s): Bennington Floodplain 2007 1m and related SLOPE datasets. Created using ArcGIS "SLOPE" command to produce...

  7. Options for gas-to-liquids technology in Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, E.P.

    1999-12-01

    The purpose of this work was to assess the effect of applying new technology to the economics of a proposed natural gas-to-liquids (GTL) plant, to evaluate the potential of a slower-paced, staged deployment of GTL technology, and to evaluate the effect of GTL placement of economics. Five scenarios were economically evaluated and compared: a no-major-gas-sales scenario, a gas-pipeline/LNG scenario, a fast-paced GTL development scenario, a slow-paced GTL development scenario, and a scenario which places the GTL plant in lower Alaska, instead of on the North Slope. Evaluations were completed using an after-tax discounted cash flow analysis. Results indicate that the slow-paced GTL scenario is the only one with a rate of return greater than 10%. The slow-paced GTL development would allow cost saving on subsequent expansions. These assumed savings, along with the lowering of the transportation tariff, combine to distinguish this option for marketing the North Slope gas from the other scenarios. Critical variables that need further consideration include the GTL plant cost, the GTL product premium, and operating and maintenance costs.

  8. Options for Gas-to-Liquids Technology in Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, Eric Partridge

    1999-10-01

    The purposes of this work was to assess the effect of applying new technology to the economics of a proposed natural gas-to-liquids (GTL) plant, to evaluate the potential of a slower-paced, staged deployment of GTL technology, and to evaluate the effect of GTL placement of economics. Five scenarios were economically evaluated and compared: a no-major-gas-sales scenario, a gas-pipeline/LNG scenario, a fast-paced GTL development scenario, a slow-paced GTL development scenario, and a scenario which places the GTL plant in lower Alaska, instead of on the North Slope. Evaluations were completed using an after-tax discounted cash flow analysis. Results indicate that the slow-paced GTL scenario is the only one with a rate of return greater than 10 percent. The slow-paced GTL development would allow cost saving on subsequent expansions. These assumed savings, along with the lowering of the transportation tariff, combine to distinquish this option for marketing the North Slope gas from the other scenarios. Critical variables that need further consideration include the GTL plant cost, the GTL product premium, and operating and maintenance costs.

  9. The development rule of man-land relationship and Sustainable development for the artificial oasis in the east of north slopes of Tianshan Mountain

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The paper researches on the pattern of man-land relationship of artificial oasis in the east of north Tianshan Mountain, the development of Qitai artificial oasis and its relationship with environment, analyzes the factors influencing the change of Qitai artificial oasis and economic growth through grey analysis, and suggests the approaches of sustainable development of Qitai artificial oasis. Research shows that the pattern of artificial oasis and its environment had gone through three phases: the relatively harmonious stage, the unharmonious stage, and the new fragile balance stage. It also shows that the garden and the shelter-forest are useful to the sustainable development of Qitai oasis according to grey analysis.

  10. Wing size and shape variation of Phlebotomus papatasi (Diptera: Psychodidae) populations from the south and north slopes of the Atlas Mountains in Morocco.

    Science.gov (United States)

    Prudhomme, Jorian; Gunay, Filiz; Rahola, Nil; Ouanaimi, Fouad; Guernaoui, Souad; Boumezzough, Ali; Bañuls, Anne-Laure; Sereno, Denis; Alten, Bulent

    2012-06-01

    The wing shape and size morphology of populations of the medically important phlebotomine sand fly, Phlebotomus papatasi, were examined in two endemic (south of the Atlas Mountains) and nonendemic (north of the Atlas Mountains) foci of cutaneous leishmaniasis by using geometric morphometrics in Morocco. Although it is present in all of Morocco, P. papatasi is the main vector of Leishmania major in only southern part of the Atlas Mountains. There are four major mountain ranges that serve as geographical barriers for species distribution in the study area and at least four gaps were recognized among these barriers. We found statistically significant differences in wing shape morphology between southern and northern populations. Analysis clearly recognized two main groups of populations on both sides of the mountains. The graphical depiction of Principal Component Analysis (PCA) and Canonical Variates Analysis (CVA) confirmed our morphometric study suggesting that the difference in wing morphology between the populations indicates that the population of P. papatasi shows phenotypic plasticity in the study area. According to centroid size analyses, which were used as measures of wing size differences among different sites, the north population of P. papatasi had relatively larger wings than the south population.

  11. Evaluation of TRIGRS (transient rainfall infiltration and grid-based regional slope-stability analysis)'s predictive skill for hurricane-triggered landslides: A case study in Macon County, North Carolina

    Science.gov (United States)

    Liao, Z.; Hong, Y.; Kirschbaum, D.; Adler, R.F.; Gourley, J.J.; Wooten, R.

    2011-01-01

    The key to advancing the predictability of rainfall-triggered landslides is to use physically based slope-stability models that simulate the transient dynamical response of the subsurface moisture to spatiotemporal variability of rainfall in complex terrains. TRIGRS (transient rainfall infiltration and grid-based regional slope-stability analysis) is a USGS landslide prediction model, coded in Fortran, that accounts for the influences of hydrology, topography, and soil physics on slope stability. In this study, we quantitatively evaluate the spatiotemporal predictability of a Matlab version of TRIGRS (MaTRIGRS) in the Blue Ridge Mountains of Macon County, North Carolina where Hurricanes Ivan triggered widespread landslides in the 2004 hurricane season. High resolution digital elevation model (DEM) data (6-m LiDAR), USGS STATSGO soil database, and NOAA/NWS combined radar and gauge precipitation are used as inputs to the model. A local landslide inventory database from North Carolina Geological Survey is used to evaluate the MaTRIGRS' predictive skill for the landslide locations and timing, identifying predictions within a 120-m radius of observed landslides over the 30-h period of Hurricane Ivan's passage in September 2004. Results show that within a radius of 24 m from the landslide location about 67% of the landslide, observations could be successfully predicted but with a high false alarm ratio (90%). If the radius of observation is extended to 120 m, 98% of the landslides are detected with an 18% false alarm ratio. This study shows that MaTRIGRS demonstrates acceptable spatiotemporal predictive skill for landslide occurrences within a 120-m radius in space and a hurricane-event-duration (h) in time, offering the potential to serve as a landslide warning system in areas where accurate rainfall forecasts and detailed field data are available. The validation can be further improved with additional landslide information including the exact time of failure for each

  12. Importance of the national petroleum reserve-alaska for aquatic birds.

    Science.gov (United States)

    Bart, Jonathan; Platte, Robert M; Andres, Brad; Brown, Stephen; Johnson, James A; Larned, William

    2013-12-01

    We used data from aerial surveys (1992-2010) of >100,000 km(2) and ground surveys (1998-2004) of >150 km(2) to estimate the density and abundance of birds on the North Slope of Alaska (U.S.A.). In the ground surveys, we used double sampling to estimate detection ratios. We used the aerial survey data to compare densities of birds and Arctic fox (Vulpes lagopus), the major nest predator of birds, on the North Slope, in Prudhoe Bay, and in nearby areas. We partitioned the Prudhoe Bay oil field into 2 × 2 km plots and determined the relation between density of aquatic birds and density of roads, buildings, and other infrastructure in these plots. Abundance and density (birds per square kilometer) of 3 groups of aquatic birds-waterfowl, loons, and grebes; shorebirds; and gulls, terns, and jaegers-were highest in the National Petroleum Reserve-Alaska (NPRA) and lowest in the Arctic National Wildlife Refuge. Six other major wetlands occur in the Arctic regions of Canada and Russia, but the largest population of aquatic birds was in the NPRA. Aquatic birds were concentrated in the northern part of the NPRA. For example, an area that covered 18% of the NPRA included 53% of its aquatic birds. The aerial surveys showed that bird density was not lower and fox density was not higher in Prudhoe Bay than in surrounding areas. Density of infrastructure did not significantly affect bird density for any group of species. Our results establish that the NPRA is one of the most important areas for aquatic birds in the Arctic. Our results and those of others also indicate that oil production, as practiced in Prudhoe Bay, does not necessarily lead to substantial declines in bird density or productivity in or near the developed areas. Prioridades para la Conservación de Aves en el Norte de Alaska.

  13. ALASKA OIL AND GAS EXPLORATION, DEVELOPMENT, AND PERMITTING PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Richard McMahon; Robert Crandall; Chas Dense; Sean Weems

    2003-08-04

    The objective of this project is to eliminate three closely inter-related barriers to oil production in Alaska through the use of a geographic information system (GIS) and other information technology strategies. These barriers involve identification of oil development potential from existing wells, planning projects to efficiently avoid conflicts with other interests, and gaining state approvals for exploration and development projects. Each barrier is the result of either current labor-intensive methods or poorly accessible information. This project brings together three parts of the oil exploration, development, and permitting process to form the foundation for a more fully integrated information technology infrastructure for the State of Alaska. This web-based system will enable the public and other review participants to track permit status, submit and view comments, and obtain important project information online. By automating several functions of the current manual process, permit applications will be completed more quickly and accurately, and agencies will be able to complete reviews with fewer delays. The application will include an on-line diagnostic Coastal Project Questionnaire to determine the suite of permits required for a specific project. The application will also automatically create distribution lists based on the location and type of project, populate document templates for project review start-ups, public notices and findings, allow submission of e-comments, and post project status information on the Internet. Alaska has nearly one-quarter of the nation's supply of crude oil, at least five billion barrels of proven reserves. The American Association of Petroleum Geologists report that the 1995 National Assessment identified the North Slope as having 7.4 billion barrels of technically recoverable oil and over 63 trillion cubic feet of natural gas. From these reserves, Alaska produces roughly one-fifth of the nation's daily crude oil

  14. Harmonic Characteristics of Heat Flux Diurnal Variation of North Wall and Back Slope in Northern Solar Greenhouse%北方日光温室北墙和后坡热通量日变化的谐波特征

    Institute of Scientific and Technical Information of China (English)

    张昆; 黎贞发; 李天来

    2012-01-01

    为了确定日光温室北墙和后坡热通量日变化的谐波组成与相应周期,采用谐波分析法,以辽沈Ⅰ型日光温室为研究用温室,分别进行了有无作物条件下的试验.结果表明,无作物区日变化曲线由以π/72、π/36和π/24为周期的正弦曲线组成;作物区日变化曲线由以π/72、π/36为周期的正弦曲线组成,作物明显影响了日光温室北墙和后坡热通量日变化的谐波成分和相应周期.其中选定谐波所占比重均达到90%以上,说明日光温室北墙和后坡的热通量日变化可以用相应周期的谐波组合表达,并且可以利用谐波分析法进行日光温室热通量的日变化特征的研究.%To investigate harmonic component and corresponding period of heat flux diurnal variation on north wall and back slope in solar greenhouse, the experiment was conducted with Liaoshen Greenhouse I under different conditions with crops and without crops by using Harmonic analysis method. The results showed that diurnal variation curve was composed of sinusoids by π/72, π/36 and π/24 cycles without crops, and by π/72 and tt/36 cycles with crops. Crops affected harmonic component and corresponding period significantly. Moreover, investigated harmonic accounted for more than 90% , which indicated that heat flux diurnal variation on north wall and back slope could be expressed by harmonic component during corresponding period, and harmonic analysis could be used to research for heat flux diurnal variation in solar greenhouse.

  15. Introduction to Special Section: The Trans-Alaska Crustal Transect (TACT) Across Arctic Alaska

    Science.gov (United States)

    Plafker, George; Mooney, Walter D.

    1997-01-01

    This special section of the Journal of Geophysical Research addresses the composition and structural evolution of the lithosphere in northern Alaska. Investigations reported in this section were mainly undertaken as part of the Trans-Alaska Crustal Transect (TACT), an integrated geological and geophysical transect of the entire Alaskan lithosphere along a north-south corridor undertaken from 1984 to 1992 (Figure 1). The onshore segment of the transect approximately follows along the route of the trans-Alaskan pipeline; the offshore segment extends across the continental margin in the Gulf of Alaska to the Pacific plate. The TACT line is unique in that it provides a coordinated onshore/offshore geological and geophysical traverse of the North American plate in Alaska from the active convergent Pacific margin to the passive Arctic margin of the continent.

  16. Currents, attenuation, temperature, conductivity, and pressure in the North Atlantic Ocean on the New England Continental Slope from the RV OCEANUS from November 10th, 1982 through November 18th, 1984 (NODC Accession 0066097)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A study of currents on the Continental Slope designed to describe the currents and to investigate the transport of sediment from the shelf to the slope. This work...

  17. Cliff swallow populations in the southern Askinuk Mountains, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — During breeding season, cliff swallows are widely distributed throughout Alaska and North America south to Mexico, and they are locally common in western and...

  18. Trans-Alaska Crustal Transect and continental evolution involving subduction underplating and synchronous foreland thrusting

    Science.gov (United States)

    Fuis, G.S.; Moore, T.E.; Plafker, G.; Brocher, T.M.; Fisher, M.A.; Mooney, W.D.; Nokleberg, W.J.; Page, R.A.; Beaudoin, B.C.; Christensen, N.I.; Levander, A.R.; Lutter, W.J.; Saltus, R.W.; Ruppert, N.A.

    2008-01-01

    We investigate the crustal structure and tectonic evolution of the North American continent in Alaska, where the continent has grown through magmatism, accretion, and tectonic underplating. In the 1980s and early 1990s, we conducted a geological and geophysical investigation, known as the Trans-Alaska Crustal Transect (TACT), along a 1350-km-long corridor from the Aleutian Trench to the Arctic coast. The most distinctive crustal structures and the deepest Moho along the transect are located near the Pacific and Arctic margins. Near the Pacific margin, we infer a stack of tectonically underplated oceanic layers interpreted as remnants of the extinct Kula (or Resurrection) plate. Continental Moho just north of this underplated stack is more than 55 km deep. Near the Arctic margin, the Brooks Range is underlain by large-scale duplex structures that overlie a tectonic wedge of North Slope crust and mantle. There, the Moho has been depressed to nearly 50 km depth. In contrast, the Moho of central Alaska is on average 32 km deep. In the Paleogene, tectonic underplating of Kula (or Resurrection) plate fragments overlapped in time with duplexing in the Brooks Range. Possible tectonic models linking these two regions include flat-slab subduction and an orogenic-float model. In the Neogene, the tectonics of the accreting Yakutat terrane have differed across a newly interpreted tear in the subducting Pacific oceanic lithosphere. East of the tear, Pacific oceanic lithosphere subducts steeply and alone beneath the Wrangell volcanoes, because the overlying Yakutat terrane has been left behind as underplated rocks beneath the rising St. Elias Range, in the coastal region. West of the tear, the Yakutat terrane and Pacific oceanic lithosphere subduct together at a gentle angle, and this thickened package inhibits volcanism. ?? 2008 The Geological Society of America.

  19. A multiyear estimate of methane fluxes in Alaska from CARVE atmospheric observations

    Science.gov (United States)

    Miller, Scot M.; Miller, Charles E.; Commane, Roisin; Chang, Rachel Y.-W.; Dinardo, Steven J.; Henderson, John M.; Karion, Anna; Lindaas, Jakob; Melton, Joe R.; Miller, John B.; Sweeney, Colm; Wofsy, Steven C.; Michalak, Anna M.

    2016-10-01

    Methane (CH4) fluxes from Alaska and other arctic regions may be sensitive to thawing permafrost and future climate change, but estimates of both current and future fluxes from the region are uncertain. This study estimates CH4 fluxes across Alaska for 2012-2014 using aircraft observations from the Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) and a geostatistical inverse model (GIM). We find that a simple flux model based on a daily soil temperature map and a static map of wetland extent reproduces the atmospheric CH4 observations at the statewide, multiyear scale more effectively than global-scale process-based models. This result points to a simple and effective way of representing CH4 fluxes across Alaska. It further suggests that process-based models can improve their representation of key processes and that more complex processes included in these models cannot be evaluated given the information content of available atmospheric CH4 observations. In addition, we find that CH4 emissions from the North Slope of Alaska account for 24% of the total statewide flux of 1.74 ± 0.26 Tg CH4 (for May-October). Global-scale process models only attribute an average of 3% of the total flux to this region. This mismatch occurs for two reasons: process models likely underestimate wetland extent in regions without visible surface water, and these models prematurely shut down CH4 fluxes at soil temperatures near 0°C. Lastly, we find that the seasonality of CH4 fluxes varied during 2012-2014 but that total emissions did not differ significantly among years, despite substantial differences in soil temperature and precipitation.

  20. Origin and accumulation mechanism of shallow gas in the North Baodao slope, Qiongdongnan Basin, South China Sea%琼东南盆地宝岛北坡浅层天然气成因与成藏机制

    Institute of Scientific and Technical Information of China (English)

    黄保家; 李里; 黄合庭

    2012-01-01

    On the basis of geochemical characteristics and origins of gases in the North Baodao slope of the Qiongdongnan Basin, the gas migration and accumulation episodes and reservoir forming time are investigated and the reservoir forming model is built for the BD13 shallow gas pools. The chemical composition and carbon isotopic data of the shallow gas, are compared with the characteristics of BD19-2 high-mature gas from the south section of the same structural belt, which reveals that the shallow gas of the BD13 gas pools is a mixture of biogas/low mature gas and some mature gas. In combination with the associated condensate biomarkers and the inclusions data, it is inferred that the biogas and low mature gas in the BD13 gas pools came from the nearby immature to low mature source rocks of the Miocene to Oligocene and charged approximately 3 Ma ago; whereas the high-mature gas generated by the Yacheng Formation source rock in the Badao Sag migrated lately into the reservoirs. Geochemical and geological data show that the No.2 fault system acts as the key pathway for upward gas migration into the shallow reservoirs, and that the sand-bodies within the Miocene Meishan and Sanya Formations are the main conduits for lateral migration of the gas. This gas migration pattern implies that the Songdong-North Baodao slope has favorable gas exploration potential in the future gas exploration of the east shallow water area in the Qiongdongnan Basin.%根据琼东南盆地宝岛北坡天然气地球化学特征和来源,研究宝岛13区浅层气田运聚期次和成藏时间,建立天然气运移成藏模式.依据宝岛13区浅层天然气组成和δ13C1、δ13C2特征,并与同一构造带南部下倾方向宝岛19-2构造高成熟天然气特征比较,认为宝岛13区浅层天然气可能是以生物气/低熟气为主含有部分成熟气的混合气.结合共生的凝析油标志物特征和包裹体信息,推测生物气/低熟气源于附近未熟—低熟的中新统—渐

  1. Alaska Subsistence Use Combined 10 Years

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — In 2004 Stephen R. Braund & Associates, in association with the North Slope Borough Department of Wildlife and under contract to BOEM, initiated a subsistence...

  2. Study on Poisonous Pteridophyte Plants in the North Slope of Taibai Mountain Nature Reserve%太白山自然保护区北坡有毒蕨类植物研究

    Institute of Scientific and Technical Information of China (English)

    左茜; 李璟琦; 谢梓燚; 贺钰

    2014-01-01

    The distribution of wild poisonous pteridophyte plants in the north slope of Taibai Mountain Nature Reserve was studied by the author through three following ways :by reading references ,climbing up the mountain and investigating in wild field ,and studying the specimens preserved before .The results indicated that there are 7 species in Taibai Mountain Nature Reserve ,which takes 6 .4% species of the to-tal poisonous pteridophyte plants .According to different characters and usages ,poisonous pteridophyte plant were classified into medicine ,edibles and ornamental plants .The study provided scientific evidences for further exploitation and utilization of wild poisonous pteridophyte plants in Taibai Mountain Nature Reserve .%通过野外实地考察、室内标本鉴定和查阅整理资料相结合的方法,对太白山自然保护区有毒蕨类植物的种类、分布、有毒成分及其利用状况进行研究。结果表明:太白山自然保护区有毒蕨类植物有5科5属7种,均为小毒,占蕨类总数的6.4%,有药用、食用、观赏等多种用途。本研究可为合理开发和利用太白山有毒蕨类植物提供理论依据。

  3. North pacific right whale surveys conducted in the Bering Sea and North Pacific Ocean by Alaska Fisheries Science Center, National Marine Mammal Laboratory from 2007-08-01 to 2011-09-10 (NCEI Accession 0133935)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The North Pacific right whale (NPRW) was heavily hunted between the 17th and the 20th centuries. Protection was supposedly afforded by international treaties in the...

  4. Caledonian Deformation in Polydeformed Pre-Mississippian Rocks of the Northeast Brooks Range, Alaska

    Science.gov (United States)

    Johnson, B. G.; Toro, J.; Benowitz, J.

    2013-12-01

    In the northeastern Brooks Range of Alaska there are polydeformed metasedimentary and metavolcanic rocks exposed below a major pre-Mississippian unconformity. Elsewhere in northern Alaska it has been challenging to correlate the tectonic fabrics of these early Paleozoic to Neoproterozoic rocks to the different orogenic events of the Arctic because of the strong overprint of Mesozoic and Tertiary Brookian deformation. However, our recent field investigations along the Kongakut and Aichiklik rivers of ANWR have identified an older (pre-Brookian) structural event based on the orientation of penetrative cleavage planes and a contrast in folding style to Brookian structures. Many of the cleavage planes are north dipping and orientated parallel to the axial planes of south-vergent folds. Although metamorphic grade is generally low, in localized areas the cleavage planes contain white micas, whose petrologic and isotopic characteristics indicate that they crystallized during fabric formation. 40Ar/39Ar dating of the white micas yield a metamorphic age of ~400 Ma (Early Devonian). This is evidence for a south-directed structural event which is contemporaneous with Caledonian deformation in East Greenland and Svalbard. Stratigraphicaly, the basement consists of a diverse package of highly deformed marine clastic sediments, and a thick section of basaltic to andesitic flows and volcaniclastic rocks, the Whale Mountain volcanics, which have a sharp southern contact but grade northward and upwards into the clastic rocks. All units are metamorphosed to lower greenschist facies. We are currently investigating the age and geochemical characteristics of the Whale Mountain volcanics to determine their tectonic affinity and role in the assemblage of the North Slope block of Northern Alaska.

  5. Alaska Radiometric Ages

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Alaska Radiometric Age file is a database of radiometric ages of rocks or minerals sampled from Alaska. The data was collected from professional publications...

  6. Operational Challenges in Gas-To-Liquid (GTL) Transportation Through Trans Alaska Pipeline System (TAPS)

    Energy Technology Data Exchange (ETDEWEB)

    Godwin A. Chukwu; Santanu Khataniar; Shirish Patil; Abhijit Dandekar

    2006-06-30

    Oil production from Alaskan North Slope oil fields has steadily declined. In the near future, ANS crude oil production will decline to such a level (200,000 to 400,000 bbl/day) that maintaining economic operation of the Trans-Alaska Pipeline System (TAPS) will require pumping alternative products through the system. Heavy oil deposits in the West Sak and Ugnu formations are a potential resource, although transporting these products involves addressing important sedimentation issues. One possibility is the use of Gas-to-Liquid (GTL) technology. Estimated recoverable gas reserves of 38 trillion cubic feet (TCF) on the North Slope of Alaska can be converted to liquid with GTL technology and combined with the heavy oils for a product suitable for pipeline transport. Issues that could affect transport of this such products through TAPS include pumpability of GTL and crude oil blends, cold restart of the pipeline following a prolonged winter shutdown, and solids deposition inside the pipeline. This study examined several key fluid properties of GTL, crude oil and four selected blends under TAPS operating conditions. Key measurements included Reid Vapor Pressure, density and viscosity, PVT properties, and solids deposition. Results showed that gel strength is not a significant factor for the ratios of GTL-crude oil blend mixtures (1:1; 1:2; 1:3; 1:4) tested under TAPS cold re-start conditions at temperatures above - 20 F, although Bingham fluid flow characteristics exhibited by the blends at low temperatures indicate high pumping power requirements following prolonged shutdown. Solids deposition is a major concern for all studied blends. For the commingled flow profile studied, decreased throughput can result in increased and more rapid solid deposition along the pipe wall, resulting in more frequent pigging of the pipeline or, if left unchecked, pipeline corrosion.

  7. Ice core records of monoterpene- and isoprene-SOA tracers from Aurora Peak in Alaska since 1660s: Implication for climate change variability in the North Pacific Rim

    Science.gov (United States)

    Pokhrel, Ambarish; Kawamura, Kimitaka; Ono, Kaori; Seki, Osamu; Fu, Pingqing; Matoba, Sumio; Shiraiwa, Takayuki

    2016-04-01

    Monoterpene and isoprene secondary organic aerosol (SOA) tracers are reported for the first time in an Alaskan ice core to better understand the biological source strength before and after the industrial revolution in the Northern Hemisphere. We found significantly high concentrations of monoterpene- and isoprene-SOA tracers (e.g., pinic, pinonic, and 2-methylglyceric acids, 2-methylthreitol and 2-methylerythritol) in the ice core, which show historical trends with good correlation to each other since 1660s. They show positive correlations with sugar compounds (e.g., mannitol, fructose, glucose, inositol and sucrose), and anti-correlations with α-dicarbonyls (glyoxal and methylglyoxal) and fatty acids (e.g., C18:1) in the same ice core. These results suggest similar sources and transport pathways for monoterpene- and isoprene-SOA tracers. In addition, we found that concentrations of C5-alkene triols (e.g., 3-methyl-2,3,4-trihydroxy-1-butene, cis-2-methyl 1,3,4-trihydroxy-1-butene and trans-2-methyl-1,3,4-trihydroxy-1-butene) in the ice core have increased after the Great Pacific Climate Shift (late 1970s). They show positive correlations with α-dicarbonyls and fatty acids (e.g., C18:1) in the ice core, suggesting that enhanced oceanic emissions of biogenic organic compounds through the marine boundary layer are recorded in the ice core from Alaska. Photochemical oxidation process for these monoterpene- and isoprene-/sesquiterpene-SOA tracers are suggested to be linked with the periodicity of multi-decadal climate oscillations and retreat of sea ice in the Northern Hemisphere.

  8. Strength of the landward slopes of sea dikes in Vietnam

    NARCIS (Netherlands)

    Trung, L.H.; Verhagen, H.J.; Van der Meer, J.W.; Cat, V.M.

    2012-01-01

    The landware slopes of sea dikes in the north of Vietnam are steep and solely constructed by soil covered with grass due to the budget constraints and also the out-of-date design guidelines.The resistance against erosion due to wave overtopping of several grass covered slopes were tested with the Wa

  9. Monitoring Recent Surging of the Yulinchuan Glacier on North Slopes of Muztag Range by Remote Sensing%木孜塔格西北坡鱼鳞川冰川跃动遥感监测

    Institute of Scientific and Technical Information of China (English)

    郭万钦; 刘时银; 许君利; 魏俊锋; 丁良福

    2012-01-01

    Landsat monitoring discovered that the middle branch of Yulinchuan Glacier,located on the north slopes of Muztag Range,was surging during 2007-2011.As a result,its north terminus advanced(548±34) m.Further study revealed that the surging was substantially from October,2008 to March,2009.During the surging,the glacier surface changed a great deal;include rapid development of surface crevasses,fast surface movement and large horizontal displacement.Part of the glacier surface,about 4.8 km in length,had drastically cracked,with the first crevasse in the lower part of the accumulation area,and then gradually spread upwards and downwards.It was found that in most parts of the glacier between the terminus and central section there were evident horizontal displacements,more than 1 km.At the meantime,surface velocity calculation also demonstrated that most parts of the glacier have experienced drastic changing in moving velocity,with the maximum velocity of about(13.3±1.5) m·d-1 on the middle part of the glacier.The velocity change also expresses an impressive feature of the surging in middle Yulinchuan Glacier.That is the fast movement during the surging starting from the northern terminus and then extending upwards.%基于Landsat卫星数据的遥感监测发现,木孜塔格峰西北坡鱼鳞川冰川的中支在2007-2011年间发生了跃动,冰川北侧末端在几年内前进距离达到了(548±34)m.进一步的监测发现,该冰川的大幅跃动主要发生于2008年10月至2009年3月.跃动期间冰川表面约4.8km长的范围经历了急剧的破碎化过程,并呈现出最早由冰川中部积蓄区下段开始,然后向上下游逐渐扩展的特征.对冰面裂隙及其他特征点的追踪发现,冰川除积累区以外的部位都产生明显的位移,其中冰川中部以下至冰舌部各点的位移都在1km以上.同时,冰面运动速度的计算结果也显示,冰川各个部分都经历了急剧的运动速度变化过程,其中冰

  10. 天山北坡城市群空间组织形态的识别研究%Identification of spatial organization and spatial morphology of urban agglomeration in North Slope of Tianshan Mountains

    Institute of Scientific and Technical Information of China (English)

    季珏; 高晓路

    2012-01-01

    正确认识天山北坡城市群的空间组织结构以及空间发展形态,对于完善绿洲城市群的发展理论和规划具有重要意义.以天山北坡城市群为研究对象,通过资源环境承载力的分析,总结出未来城市群发展面临的客观制约因素;通过中心性分析、断裂点理论修正的Voronoi多边形等方法识别出城市群的中心城市及各自的辐射范围城市;通过引力模型识别出城市之间的社会经济联系强度.据此,利用多维尺度分析的方法,可视化地展现了天山北坡城市群发展的空间组织形态.经调查了解:(1)乌鲁木齐市与克拉玛依市是未来城市群发展的两个中心城市,五家渠市、阜康市、昌吉市、石河子市周边目前属于乌鲁木齐市的辐射范围城市,奎屯市,乌苏市属于克拉玛依市的辐射范围城市;(2)城市群内部的城市之间的联系比较松散,特别是两个中心城市之间联系较弱;(3)城市群的空间发展形态为串珠式,是一种特殊的走廊式空间形态.%Oasis urban agglomerations have distinctive spatial organizations and morphology with other urban agglomerations as their special landforms and environmental restricts. So how to understand the particularity of oasis urban agglomeration development, and then put forward the suitable development suggestions is an important issue. This paper takes urban agglomeration on the north slope of the Tianshan Mountains as an example, aiming to identify the particular development mode of this representative arid urban agglomeration. Many statistical models and methods were used to interpret the spatial organizations. To be mentioned, visualization of urban agglomeration's spatial morphology was innovatively made in this paper. There are three steps to identify the spatial organization of the urban agglomerations. First, central cities in this region should be picked up. Here, centricity analysis method was used to identify central

  11. Surface ocean velocities obtained by HF radar from stations located along coastal waters of Antarctica, Hawaii, North Slope Alaska, Puerto Rico/Virgin Islands, eastern US/Gulf of Mexico and western US during July 2015 (NCEI Accession 0138671)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The archival package contains ocean surface radial velocities collected from High frequency (HF) radar stations. NDBC, which with SIO assembles data from the IOOS HF...

  12. Surface ocean velocities obtained by HF radar from stations located along coastal waters of Antarctica, Hawaii, North Slope Alaska, Puerto Rico/Virgin Islands, eastern US/Gulf of Mexico and western US during September 2015 (NCEI Accession 0138948)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The archival package contains ocean surface radial velocities collected from High frequency (HF) radar stations. NDBC, which with SIO assembles data from the IOOS HF...

  13. Surface ocean velocities obtained by HF radar from stations located along coastal waters of Hawaii, North Slope Alaska, Puerto Rico/Virgin Islands, eastern US/Gulf of Mexico and western US during June 2016 (NCEI Accession 0155984)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The archival package contains ocean surface radial velocities collected from High frequency (HF) radar stations. NDBC, which with SIO assembles data from the IOOS HF...

  14. Surface ocean velocities obtained by HF radar from stations located along coastal waters of Antarctica, Hawaii, North Slope Alaska, Puerto Rico/Virgin Islands, eastern US/Gulf of Mexico and western US during August 2015 (NCEI Accession 0138776)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The archival package contains ocean surface radial velocities collected from High frequency (HF) radar stations. NDBC, which with SIO assembles data from the IOOS HF...

  15. Surface ocean velocities obtained by HF radar from stations located along coastal waters of Antarctica, Hawaii, North Slope Alaska, Puerto Rico/Virgin Islands, eastern US/Gulf of Mexico and western US during October 2015 (NCEI Accession 0139156)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The archival package contains ocean surface radial velocities collected from High frequency (HF) radar stations. NDBC, which with SIO assembles data from the IOOS HF...

  16. Surface ocean velocities obtained by HF radar from stations located along coastal waters of Hawaii, North Slope Alaska, Puerto Rico/Virgin Islands, eastern US/Gulf of Mexico and western US during August 2016 (NCEI Accession 0156626)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The archival package contains ocean surface radial velocities collected from High frequency (HF) radar stations. NDBC, which with SIO assembles data from the IOOS HF...

  17. Surface ocean velocities obtained by HF radar from stations located along coastal waters of Hawaii, North Slope Alaska, Puerto Rico/Virgin Islands, eastern US/Gulf of Mexico and western US during July 2016 (NCEI Accession 0156405)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The archival package contains ocean surface radial velocities collected from High frequency (HF) radar stations. NDBC, which with SIO assembles data from the IOOS HF...

  18. Surface ocean velocities obtained by HF radar from stations located along coastal waters of Antarctica, Hawaii, North Slope Alaska, Puerto Rico/Virgin Islands, eastern US/Gulf of Mexico and western US during November 2015 (NCEI Accession 0139553)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The archival package contains ocean surface radial velocities collected from High frequency (HF) radar stations. NDBC, which with SIO assembles data from the IOOS HF...

  19. Alaska coal geology, resources, and coalbed methane potential

    Science.gov (United States)

    Flores, Romeo M.; Stricker, Gary D.; Kinney, Scott A.

    2004-01-01

    Estimated Alaska coal resources are largely in Cretaceous and Tertiary rocks distributed in three major provinces. Northern Alaska-Slope, Central Alaska-Nenana, and Southern Alaska-Cook Inlet. Cretaceous resources, predominantly bituminous coal and lignite, are in the Northern Alaska-Slope coal province. Most of the Tertiary resources, mainly lignite to subbituminous coal with minor amounts of bituminous and semianthracite coals, are in the other two provinces. The combined measured, indicated, inferred, and hypothetical coal resources in the three areas are estimated to be 5,526 billion short tons (5,012 billion metric tons), which constitutes about 87 percent of Alaska's coal and surpasses the total coal resources of the conterminous United States by 40 percent. Coal mining has been intermittent in the Central Alaskan-Nenana and Southern Alaska-Cook Inlet coal provinces, with only a small fraction of the identified coal resource having been produced from some dozen underground and strip mines in these two provinces. Alaskan coal resources have a lower sulfur content (averaging 0.3 percent) than most coals in the conterminous United States are within or below the minimum sulfur value mandated by the 1990 Clean Air Act amendments. The identified resources are near existing and planned infrastructure to promote development, transportation, and marketing of this low-sulfur coal. The relatively short distances to countries in the west Pacific Rim make them more exportable to these countries than to the lower 48 States of the United States. Another untapped but potential resource of large magnitude is coalbed methane, which has been estimated to total 1,000 trillion cubic feet (28 trillion cubic meters) by T.N. Smith 1995, Coalbed methane potential for Alaska and drilling results for the upper Cook Inlet Basin: Intergas, May 15 - 19, 1995, Tuscaloosa, University of Alabama, p. 1 - 21.

  20. Arctic Slope and Trans-Alaska Pipeline Task Force report: The bird resources of Alaska's arctic slope and petroleum development

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report was written in order to better understand the possible effects of petroleum exploration, development, and related activities upon the bird resources of...

  1. Evaluate ERTS imagery for mapping and detection of changes of snowcover on land and on glaciers. [North Cascades, Washington and Tweedsmuir Glacier, Alaska

    Science.gov (United States)

    Meier, M. F. (Principal Investigator)

    1974-01-01

    The author has identified the following significant results. Snowlines on a small (6 sq km) drainage basin were accurately measured without use of digital processing, and snow patches as small as 150 m (maximum dimension) were correctly identified, proving that the resolution of ERTS is ample for snow mapping needs. The area of snow cover on 10 individual drainage basins in the North Cascades, Washington, has been determined at 12 different times; these data can be used for more accurate forecasts of streamflow. Progress has been made in distinguishing snow in trees using multispectral analysis. Motion of the surging Tweedsmuir Glacier was measured. Velocities ranged from 2 to 88 m per day; a zone of intense crevassing also appeared to spread up and down the glacier (at about 200 m per day upglacier). This tentative result may be of great importance to an understanding of surging glacier dynamics. ERTS images also show that the most recent debris flow (20-21 August 1973) from Mount Baker can be clearly discerned and mapped, in order to monitor this potential hazard.

  2. Chemical, optical and other data collected aboard the THOMAS G. THOMPSON during cruise TN255 in the Coastal Waters of SE Alaska and North Pacific Ocean from 2010-10-16 to 2010-10-20 (NODC Accession 0104360)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0104360 includes chemical, optical and other data collected aboard the THOMAS G. THOMPSON during cruise TN255 in the Coastal Waters of SE Alaska and...

  3. Physical, profile and underway data collected aboard the Sikuliaq during cruise SKQ201504T in the Bering Sea, Gulf of Alaska and North Pacific Ocean from 2015-03-13 to 2015-03-18 (NCEI Accession 0145946)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0145946 includes physical, profile and underway data collected aboard the Sikuliaq during cruise SKQ201504T in the Bering Sea, Gulf of Alaska and...

  4. Chemical, optical and other data collected aboard the THOMAS G. THOMPSON during cruise TN282 in the Coastal Waters of SE Alaska and North Pacific Ocean from 2012-03-11 to 2012-07-06 (NODC Accession 0104374)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0104374 includes chemical, optical and other data collected aboard the THOMAS G. THOMPSON during cruise TN282 in the Coastal Waters of SE Alaska and...

  5. Underway physical and meteorological data collected aboard NOAA Ship MILLER FREEMAN in the North Pacific and Gulf of Alaska from 2001-08-05 to 2001-11-11 (NODC Accession 0000626)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical, meteorological, and other data were collected from NOAA Ship MILLER FREEMAN in the Coastal Waters of Alaska from 5 August 2001 to 11 November 2001. Data...

  6. Underway physical and meteorological data collected aboard NOAA Ship MILLER FREEMAN in the North Pacific, Bering Sea, and Gulf of Alaska from 2002-01-29 to 2002-03-26 (NCEI Accession 0000711)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical, meteorological, and other data were collected from NOAA Ship MILLER FREEMAN in coastal Alaska/Washington/Oregon from 29 January 2002 to 26 March 2002....

  7. Chemical, optical and other data collected aboard the THOMAS G. THOMPSON during cruise TN266 in the Coastal Waters of SE Alaska and North Pacific Ocean from 2011-06-27 to 2011-07-27 (NODC Accession 0104365)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0104365 includes chemical, optical and other data collected aboard the THOMAS G. THOMPSON during cruise TN266 in the Coastal Waters of SE Alaska and...

  8. Chemical, optical and other data collected aboard the THOMAS G. THOMPSON during cruise TN270 in the Coastal Waters of SE Alaska and North Pacific Ocean from 2011-09-01 to 2011-10-21 (NODC Accession 0104369)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0104369 includes chemical, optical and other data collected aboard the THOMAS G. THOMPSON during cruise TN270 in the Coastal Waters of SE Alaska and...

  9. Chemical, optical and other data collected aboard the THOMAS G. THOMPSON during cruise TN254 in the Coastal Waters of SE Alaska and North Pacific Ocean from 2010-09-09 to 2010-10-11 (NODC Accession 0104359)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0104359 includes chemical, optical and other data collected aboard the THOMAS G. THOMPSON during cruise TN254 in the Coastal Waters of SE Alaska and...

  10. Chemical, optical and other data collected aboard the THOMAS G. THOMPSON during cruise TN269 in the Coastal Waters of SE Alaska and North Pacific Ocean from 2011-09-01 to 2011-10-08 (NODC Accession 0104368)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0104368 includes chemical, optical and other data collected aboard the THOMAS G. THOMPSON during cruise TN269 in the Coastal Waters of SE Alaska and...

  11. Chemical, optical and other data collected aboard the THOMAS G. THOMPSON during cruise TN268 in the Coastal Waters of SE Alaska and North Pacific Ocean from 2011-08-11 to 2011-09-01 (NODC Accession 0104367)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0104367 includes chemical, optical and other data collected aboard the THOMAS G. THOMPSON during cruise TN268 in the Coastal Waters of SE Alaska and...

  12. Slope Streaks in Terra Sabaea

    Science.gov (United States)

    2007-01-01

    [figure removed for brevity, see original site] Figure 1 Click on image for larger version This HiRISE image shows the rim of a crater in the region of Terra Sabaea in the northern hemisphere of Mars. The subimage (figure 1) is a close-up view of the crater rim revealing dark and light-toned slope streaks. Slope streak formation is among the few known processes currently active on Mars. While their mechanism of formation and triggering is debated, they are most commonly believed to form by downslope movement of extremely dry sand or very fine-grained dust in an almost fluidlike manner (analogous to a terrestrial snow avalanche) exposing darker underlying material. Other ideas include the triggering of slope streak formation by possible concentrations of near-surface ice or scouring of the surface by running water from aquifers intercepting slope faces, spring discharge (perhaps brines), and/or hydrothermal activity. Several of the slope streaks in the subimage, particularly the three longest darker streaks, show evidence that downslope movement is being diverted around obstacles such as large boulders. Several streaks also appear to originate at boulders or clumps of rocky material. In general, the slope streaks do not have large deposits of displaced material at their downslope ends and do not run out onto the crater floor suggesting that they have little reserve kinetic energy. The darkest slope streaks are youngest and can be seen to cross cut and superpose older and lighter-toned streaks. The lighter-toned streaks are believed to be dark streaks that have lightened with time as new dust is deposited on their surface. Observation Geometry Image PSP_001808_1875 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on 15-Dec-2006. The complete image is centered at 7.4 degrees latitude, 47.0 degrees East longitude. The range to the target site was 272.1 km (170.1 miles). At this distance the

  13. Study of conglomerate reservoir types and distribution in north slope zone, Dongying depression%东营凹陷北部陡坡带砂砾岩油藏类型及序列模式

    Institute of Scientific and Technical Information of China (English)

    刘鑫金; 宋国奇; 刘惠民; 徐兵; 田美荣

    2012-01-01

    There are several conglomerate reservoir types in the eastern north steep slope zone in Dongying depression, whose distribution has an ordered sequence. By the dissection of different conglomerate traps, the basic characteristics of these, reservoirs and controlling factors of their ordered distribution are discussed. On the basis of reservoir characteristic and distribution law, the ordered reservoir combination pattern includes under-salt condensate gas reservoir, fan root lithologic reservoir, structural-lithological reservoir, and the digenesis trap reservoir that is sealed by difference of physical properties. The reservoir series, that are in order of under-salt gas play, deep zone thin oil play, medium-deep thin oil play, and shallow layer heavy oil play, are distributed ring-shaped around the subsidence centre of the basin. Every reservoir type had its particular hydrocarbon accumulation controlling factors. The main pool controlling factors of deep condensate gas and thin oil lithologic reservoir are the sealing capacity of fan root, the one for medium-deep structural-lithologic reservoir is development of small anticlinal traps, and the heavy oil is thick, which is the key controlling factors for shallow layer reservoir that is sealed by difference of physical properties. Different exploration plans are designed according to the reservoir characters and oil distribution law.%东营凹陷北部陡坡带砂砾岩油藏表现出很强的有序性,通过对不同层系砂砾岩油藏的解剖,探讨了各类油藏的基本特征及其有序性展布的控制因素,建立了砂砾岩油藏序列模式.研究结果表明,砂砾岩油藏模式可概括为深层凝析气藏、深层扇根封堵岩性油藏、中深层构造-岩性油藏、中浅层物性差异封堵岩性油藏依次发育的油藏组合模式,在平面上呈环带状展布,由洼陷中心到盆地边缘依次发育深层气环带、深层稀油带、中深层稀油带和中浅层稠油环带.

  14. Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from ENDEAVOUR, JOHN P. TULLY and PARIZEAU in the Coastal Waters of SE Alaska, Gulf of Alaska and North Pacific Ocean from 1985-02-12 to 2010-06-18 (NODC Accession 0110260)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0110260 includes discrete sample and profile data collected from ENDEAVOUR, JOHN P. TULLY and PARIZEAU in the Coastal Waters of SE Alaska, Gulf of...

  15. Hazard assessment of vegetated slopes

    NARCIS (Netherlands)

    J.E. Norris; J.R. Greenwood; A. Achim; B.A. Gardiner; B.C. Nicoll; E. Cammeraat; S.B. Mickovski

    2008-01-01

    The hazard assessment of vegetated slopes are reviewed and discussed in terms of the stability of the slope both with and without vegetation, soil erosion and the stability of the vegetated slope from windthrow and snow loading. Slope stability can be determined by using either limit equilibrium or

  16. Zooplankton distribution and dynamics in a North Pacific Eddy of coastal origin: II. Mechanisms of eddy colonization by and retention of offshore species

    Science.gov (United States)

    Mackas, D. L.; Tsurumi, M.; Galbraith, M. D.; Yelland, D. R.

    2005-04-01

    Mesoscale anticyclonic eddies form annually in late winter along the eastern margin of the subarctic North Pacific. Eddies that originate off the southern tip of the Queen Charlotte Islands (near 52°N 132°W) are called 'Haida Eddies'. During the subsequent 1-3 years, they propagate westward into the Alaska Gyre. Enroute, the eddies are colonized by zooplankton originating from the central British Columbia continental shelf, the continental slope and along-slope boundary current, and the oceanic Alaska Gyre. Eddies also gradually lose kinetic energy, water properties, and biota to the surrounding ocean. In this paper, we analyze zooplankton samples from Haida eddies obtained in late winter, early summer and autumn of 2000, and in early summer and autumn of 2001, and compare the within-eddy zooplankton distributions, abundances, and community composition of the oceanic-origin species to observations from the continental margin and Alaska Gyre source regions. Most between-region comparisons were consistent with a hypothesis that the eddy zooplankton are a mixture intermediate in abundance and community composition between the BC continental margin and offshore Alaska Gyre source regions (although usually closer to the Alaska Gyre). However, about 30% of the comparisons showed within-eddy abundances higher than in either source region. This outcome cannot arise from mixing alone. Aggregation and retention appear to be linked to vertical distribution behavior: most of the successful taxa spend much of their time below the surface mixed layer. This minimizes their exposure to wash-out by three physical processes: Slow upwelling and surface divergence that accompanies weakening of the anticyclonic geostrophic currents. Rapid but intermittent flushing of the surface layer by Ekman transport during strong wind events. Exchange across the eddy margin/geostrophic streamlines caused by temporary displacement by wind-driven inertial currents.

  17. Slope constrained Topology Optimization

    DEFF Research Database (Denmark)

    Petersson, J.; Sigmund, Ole

    1998-01-01

    pointwise bounds on the density slopes. A finite element discretization procedure is described, and a proof of convergence of finite element solutions to exact solutions is given, as well as numerical examples obtained by a continuation/SLP (sequential linear programming) method. The convergence proof...

  18. Geologic cross section, gas desorption, and other data from four wells drilled for Alaska rural energy project, Wainwright, Alaska, coalbed methane project, 2007-2009

    Science.gov (United States)

    Clark, Arthur C.; Roberts, Stephen B.; Warwick, Peter D.

    2010-01-01

    Energy costs in rural Alaskan communities are substantial. Diesel fuel, which must be delivered by barge or plane, is used for local power generation in most off-grid communities. In addition to high costs incurred for the purchase and transport of the fuel, the transport, transfer, and storage of fuel products pose significant difficulties in logistically challenging and environmentally sensitive areas. The Alaska Rural Energy Project (AREP) is a collaborative effort between the United States Geological Survey (USGS) and the Bureau of Land Management Alaska State Office along with State, local, and private partners. The project is designed to identify and evaluate shallow (methane (CBM) and geothermal in the vicinity of rural Alaskan communities where these resources have the potential to serve as local-use power alternatives. The AREP, in cooperation with the North Slope Borough, the Arctic Slope Regional Corporation, and the Olgoonik Corporation, drilled and tested a 1,613 ft continuous core hole in Wainwright, Alaska, during the summer of 2007 to determine whether CBM represents a viable source of energy for the community. Although numerous gas-bearing coal beds were encountered, most are contained within the zone of permafrost that underlies the area to a depth of approximately 1,000 ft. Because the effective permeability of permafrost is near zero, the chances of producing gas from these beds are highly unlikely. A 7.5-ft-thick gas-bearing coal bed, informally named the Wainwright coal bed, was encountered in the sub-permafrost at a depth of 1,242 ft. Additional drilling and testing conducted during the summers of 2008 and 2009 indicated that the coal bed extended throughout the area outlined by the drill holes, which presently is limited to the access provided by the existing road system. These tests also confirmed the gas content of the coal reservoir within this area. If producible, the Wainwright coal bed contains sufficient gas to serve as a long

  19. Aerial Survey of Emperor Geese and other Waterbirds in Southwestern Alaska, Fall 1999

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A fall aerial emperor goose survey was conducted on the Alaska Peninsula for the 21st consecutive year in 1999. Replicate aerial surveys of the north side of the...

  20. Fall 1986 productivity estimates of emperor geese from aerial photographs on the Alaska peninsula

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Production estimates for emperor geese (Anser canagicus) were obtained from aerial photographs taken from six locations on the north side of the Alaska Peninsula in...

  1. Alaska geothermal bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Liss, S.A.; Motyka, R.J.; Nye, C.J. (comps.)

    1987-05-01

    The Alaska geothermal bibliography lists all publications, through 1986, that discuss any facet of geothermal energy in Alaska. In addition, selected publications about geology, geophysics, hydrology, volcanology, etc., which discuss areas where geothermal resources are located are included, though the geothermal resource itself may not be mentioned. The bibliography contains 748 entries.

  2. The Best of Alaska

    Institute of Scientific and Technical Information of China (English)

    郑钧

    2011-01-01

    Nothing awakes Alaska like a whale exploding out of the water or an eagle (鹰) pulling a silver fish from the river. Combine these images with high mountains, brilliant icebergs and wonderful meals and you really do have the best of Alaska!

  3. Renewable Energy in Alaska

    Energy Technology Data Exchange (ETDEWEB)

    2013-03-01

    This report examines the opportunities, challenges, and costs associated with renewable energy implementation in Alaska and provides strategies that position Alaska's accumulating knowledge in renewable energy development for export to the rapidly growing energy/electric markets of the developing world.

  4. 太白山北坡冬、春季鸟类群落多样性%Diversity of bird communities on the north slope of Taibai Mountain in winter and spring

    Institute of Scientific and Technical Information of China (English)

    罗磊; 赵洪峰; 张宏; 李先敏; 侯玉宝; 高学斌; 李双喜

    2012-01-01

    In the winter (November) of 2009, spring (April) of 2010, and spring (March and April) of 2011, a line transact method was adopted to investigate the bird communities along the north slope of Taibai Mountain, the summit of the Qinling Mountains in Northwest China. Based on the elevation and typical vegetation, six types of habitat were categorized, and representative sampling plots were selected for each habitat type. The relative abundance and estimated area were considered to calculate the relative bird density, and the dominant and common bird species were defined according to the density rank for each habitat type. Over the whole survey period with two seasons, a total of 121 bird species were recorded, belonging to 71 genera, 40 families, and 12 orders, among which, 92 species were residents, 24 species were summer breeders, and 5 species were passaging migrants. Both in winter and in spring, the birds in the habitats were mainly of resident species. There existed definite differences in the density and structure of bird communities in different habitat types within the same seasons and in the same habitat types be-tween different seasons. There also existed differences in the composition of dominant and com-mon bird species between different habitat types and different seasons. Among the habitat types, anthropogenic disturbed deciduous forest had the highest bird diversity index in both winter and spring, and deciduous forest had the highest bird evenness index in the two seasons. The similar-ity index was generally higher in adjacent habitats than in separate habitats. Except that the bird species number in the mixed forests at medium and high altitudes had somewhat increase over the previous adjacent vegetation type, the bird species richness decreased with increasing altitude, and the bird species composition had greater change, as compared with that between spring and winter.%2009年11月(冬季)、2010年4月和2011年3-4月(春季),依据海拔和典

  5. Characteristics of the air temperature and humidity on the north slope of Mt Qomolangma%珠穆朗玛峰北坡地区气温和湿度变化特征

    Institute of Scientific and Technical Information of China (English)

    杨兴国; 秦大河; 张廷军; 康世昌; 秦翔

    2012-01-01

    珠穆朗玛峰地区由于其独特的自然地理条件、举世无双的高度、脆弱而敏感的环境使其成为气候变化和环境变迁的敏感区.根据2007年5月至2008年8月在珠穆朗玛峰北坡地区7个不同海拔高度观测的逐时气温和空气湿度资料分析了该地区气温和湿度的时空变化特征.结果表明,在海拔5207、5792和5955m高度处的年平均气温分别为0.2、-4.4和-5.4℃,最高气温分别为14.6、9.1和18,6℃,最低气温分别为-24.2、-28.8和- 29.3℃;除在冰川表面以外,空气相对湿度随海拔高度的升高没有明显变化.气温和相对湿度的年变化幅度随海拔高度的升高而减小.由于冰面近地层逆温层顶部暖空气与冷空气的混合作用造成其最高气温出现时间晚于其他下垫面.年平均温度递减率为(0.72±0.01)℃/100 m,并且呈现出明显的季节变化特征.同时结合定日气象站1959--2007年的气温和降水资料,探讨了对珠穆朗玛峰北坡绒布冰川变化的影响.%Weather and climatic conditions over the Himalaya regions are of great interest to the scientific community at large. The objective of this study is to present spatial and temporal variations of air temperatures and the relative humidity on the north slope of Mt Qomolangma. Both the hourly air temperature and relative humidity were measured at the seven automatic weather stations (AWS) from 5207 to 7028 m a. s. 1. from May 2007 through September 2008. The preliminary results show that the elevational variation of the mean annual air temperature is non-linear, which decreases from 0. 2℃ at elevations of 5207 m to - 4. 4℃ at 5792 m, and - 5. 4℃ at 5955 m. The maxima are 14. 6℃ , 9. 1℃ , and 18. 6℃ , and the minima are - 24. 2℃ , - 28. 8℃ , and - 29. 3℃ at the three elevations, respectively. The relative humidity does not change significantly with increasing elevation except over the glacier ice, but the mixing ratio decreases due to the

  6. Alaska Problem Resource Manual: Alaska Future Problem Solving Program. Alaska Problem 1985-86.

    Science.gov (United States)

    Gorsuch, Marjorie, Ed.

    "Alaska's Image in the Lower 48," is the theme selected by a Blue Ribbon panel of state and national leaders who felt that it was important for students to explore the relationship between Alaska's outside image and the effect of that image on the federal programs/policies that impact Alaska. An overview of Alaska is presented first in…

  7. Slope earthquake stability

    CERN Document Server

    Changwei, Yang; Jing, Lian; Wenying, Yu; Jianjing, Zhang

    2017-01-01

    This book begins with the dynamic characteristics of the covering layerbedrock type slope, containing monitoring data of the seismic array, shaking table tests, numerical analysis and theoretical derivation. Then it focuses on the landslide mechanism and assessment method. It also proposes a model that assessing the hazard area based on the field investigations. Many questions, exercises and solutions are given. Researchers and engineers in the field of Geotechnical Engineering and Anti-seismic Engineering can benefit from it.

  8. ElevationSlope_SLOPE3p2M

    Data.gov (United States)

    Vermont Center for Geographic Information — This metadata applies to the following collection area(s): ( and related SLOPE datasets. Created using ArcGIS "SLOPE" command to produce change in elevation over the...

  9. ElevationSlope_SLOPE0p7M2013

    Data.gov (United States)

    Vermont Center for Geographic Information — This metadata applies to the following collection area(s): Rutland/GI Counties 2013 0.7m and related SLOPE datasets. Created using ArcGIS "SLOPE" command to produce...

  10. ElevationSlope_SLOPE0p7M2015

    Data.gov (United States)

    Vermont Center for Geographic Information — This metadata applies to the following collection area(s): Windham County 2015 0.7m and related SLOPE datasets. Created using ArcGIS "SLOPE" command to produce...

  11. ElevationSlope_SLOPE1p6M2010

    Data.gov (United States)

    Vermont Center for Geographic Information — This metadata applies to the following collection area(s): Missisquoi Upper 2010 1.6m and related SLOPE datasets. Created using ArcGIS "SLOPE" command to produce...

  12. ElevationSlope_SLOPE1p6M2012

    Data.gov (United States)

    Vermont Center for Geographic Information — This metadata applies to the following collection area(s): Addison County 2012 1.6m and related SLOPE datasets. Created using ArcGIS "SLOPE" command to produce...

  13. ElevationSlope_SLOPE0p7M2014

    Data.gov (United States)

    Vermont Center for Geographic Information — This metadata applies to the following collection area(s): Eastern VT 2014 0.7m and related SLOPE datasets. Created using ArcGIS "SLOPE" command to produce change in...

  14. ElevationSlope_SLOPE1p6M2008

    Data.gov (United States)

    Vermont Center for Geographic Information — This metadata applies to the following collection area(s): Missisquoi Lower 2008 1.6m and related SLOPE datasets. Created using ArcGIS "SLOPE" command to produce...

  15. ElevationSlope_SLOPE3p2M2004

    Data.gov (United States)

    Vermont Center for Geographic Information — This metadata applies to the following collection area(s): ( and related SLOPE datasets. Created using ArcGIS "SLOPE" command to produce change in elevation over the...

  16. Ocean Observing System Demonstrated in Alaska

    Science.gov (United States)

    Schoch, G. Carl; Chao, Yi

    2010-05-01

    To demonstrate the utility of an ocean observing and forecasting system with diverse practical applications—such as search and rescue, oil spill response (perhaps relevent to the current Gulf of Mexico oil spill), fisheries, and risk management—a unique field experiment was conducted in Prince William Sound, Alaska, in July and August 2009. The objective was to quantitatively evaluate the performance of numerical models developed for the sound with an array of fixed and mobile observation platforms (Figure 1). Prince William Sound was chosen for the demonstration because of historical efforts to monitor ocean circulation following the 1989 oil spill from the Exxon Valdez tanker. The sound, a highly crenulated embayment of about 10,000 square kilometers at approximately 60°N latitude along the northern coast of the Gulf of Alaska, includes about 6900 kilometers of shoreline, numerous islands and fjords, and an extensive system of tidewater glaciers descending from the highest coastal mountain range in North America. Hinchinbrook Entrance and Montague Strait are the two main deep water connections with the Gulf of Alaska. The economic base of communities in the region is almost entirely resource-dependent. For example, Cordova's economy is based on commercial fishing and Valdez's economy is supported primarily by the trans-Alaska oil pipeline terminal.

  17. Libraries in Alaska: MedlinePlus

    Science.gov (United States)

    ... this page: https://medlineplus.gov/libraries/alaska.html Libraries in Alaska To use the sharing features on ... JavaScript. Anchorage University of Alaska Anchorage Alaska Medical Library 3211 Providence Drive Anchorage, AK 99508-8176 907- ...

  18. Measuring acoustic emissions in an avalanche slope

    Science.gov (United States)

    Reiweger, Ingrid; Schweizer, Jürg

    2014-05-01

    Measurements of acoustic emissions are a common technique for monitoring damage and predicting imminent failure of a material. Within natural hazards it has already been used to successfully predict the break-off of a hanging glacier. To explore the applicability of the acoustic emission (AE) technique for avalanche prediction, we installed two acoustic sensors (with 30 kHz and 60 kHz resonance frequency) in an avalanche prone slope at the Mittelgrat in the Parsenn ski area above Davos, Switzerland. The slope is north-east facing, frequently wind loaded, and approximately 35° steep. The AE signals - in particular the event energy and waiting time distributions - were compared with slope stability. The latter was determined by observing avalanche activity. The results of two winter's measurements yielded that the exponent β of the inverse cumulative distribution of event energy showed a significant drop (from a value of 3.5 to roughly 2.5) at very unstable conditions, i.e. on the three days during our measurement periods when spontaneous avalanches released on our study slope.

  19. Alaska geology revealed

    Science.gov (United States)

    Wilson, Frederic H.; Labay, Keith A.

    2016-11-09

    This map shows the generalized geology of Alaska, which helps us to understand where potential mineral deposits and energy resources might be found, define ecosystems, and ultimately, teach us about the earth history of the State. Rock units are grouped in very broad categories on the basis of age and general rock type. A much more detailed and fully referenced presentation of the geology of Alaska is available in the Geologic Map of Alaska (http://dx.doi.org/10.3133/sim3340). This product represents the simplification of thousands of individual rock units into just 39 broad groups. Even with this generalization, the sheer complexity of Alaskan geology remains evident.

  20. Assessment and mapping of slope stability based on slope units: A case study in Yan’an, China

    Indian Academy of Sciences (India)

    Jianqi Zhuang; Jianbing Peng; Yonglong Xu; Qiang Xu; Xinghua Zhu; Wei Li

    2016-10-01

    Precipitation frequently triggers shallow landslides in the Loess Plateau of Shaanxi, China, resulting in loss of life, damage to gas and oil routes, and destruction of transport infrastructure and farmland. To assess the possibility of shallow landslides at different precipitation levels, a method to draw slope units and steepest slope profiles based on ARCtools and a new method for calculating slope stability areproposed. The methods were implemented in a case study conducted in Yan’an, north-west China. High resolution DEM (Digital Elevation Model) images, soil parameters from in-situ laboratory measurements and maximum depths of precipitation infiltration were used as input parameters in the method. Next,DEM and reverse DEM were employed to map 2146 slope units in the study area, based on which the steepest profiles of the slope units were constructed. Combining analysis of the water content of loess, strength of the sliding surface, its response to precipitation and the infinite slope stability equation, a newequation to calculate infinite slope stability is proposed to assess shallow landslide stability. The slope unit stability was calculated using the equation at 10-, 20-, 50- and 100-year return periods of antecedent effective precipitation. The number of slope units experiencing failure increased in response to increasing effective antecedent rainfall. These results were validated based on the occurrence of landslides in recent decades. Finally, the applicability and limitations of the model are discussed.

  1. Comments on the slope function

    CERN Document Server

    Kim, Minkyoo

    2016-01-01

    The exact slope function was first proposed in $SL(2)$ sector and generalized to $SU(2)$ sector later. In this note, we consider the slope function in $SU(1|1)$ sector of ${\\cal N}=4$ SYM. We derive the quantity through the method invented by N. Gromov and discuss about its validity. Further, we give comments on the slope function in deformed SYM.

  2. Bryophytes from Tuxedni Wilderness area, Alaska

    Science.gov (United States)

    Schofield, W.B.; Talbot, S. S.; Talbot, S.L.

    2002-01-01

    The bryoflora of two small maritime islands, Chisik and Duck Island (2,302 ha), comprising Tuxedni Wilderness in western lower Cook Inlet, Alaska, was examined to determine species composition in an area where no previous collections had been reported. The field study was conducted from sites selected to represent the totality of environmental variation within Tuxedni Wilderness. Data were analyzed using published reports to compare the bryophyte distribution patterns at three levels, the Northern Hemisphere, North America, and Alaska. A total of 286 bryophytes were identified: 230 mosses and 56 liverworts. Bryum miniatum, Dichodontium olympicum, and Orthotrichum pollens are new to Alaska. The annotated list of species for Tuxedni Wilderness expands the known range for many species and fills distribution gaps within Hulte??n's Central Pacific Coast district. Compared with bryophyte distribution in the Northern Hemisphere, the bryoflora of Tuxedni Wilderness primarily includes taxa of boreal (61%), montane (13%), temperate (11%), arctic-alpine (7%), cosmopolitan (7%), distribution; 4% of the total moss flora are North America endemics. A brief summary of the botanical exploration of the general area is provided, as is a description of the bryophytes present in the vegetation and habitat types of Chisik and Duck Islands.

  3. Aspect-Driven Changes in Slope Stability Due to Ecohydrologic Feedbacks

    Science.gov (United States)

    Poulos, M. J.; Pierce, J. L.; Flores, A. N.; Benner, S. G.; Smith, T. J.; McNamara, J. P.

    2009-12-01

    Seasonally integrated variation in insolation drives feedbacks among evapotranspiration, soil moisture, weathering, and erosion that lead to pronounced contrasts in slope angles and vegetation on north and south-facing hillslopes. Spatial variations in insolation associated with north-south contrasts in topographic aspect leads to corresponding variation in local microclimates and ecohydrologic regimes that, in turn, impact spatial patterns of weathering and erosion, ultimately impacting slope angles on north and south-facing slopes. Aspect-sensitive environments appear to be poised on a balance point between ecohydrologic systems, and may be especially susceptible to climate change. In the semi-arid Colorado Plateau of northeastern Arizona, cliffs often form on south-facing slopes where soil moisture is insufficient for weathering of clay-cemented sandstone that is susceptible to hydration. In contrast, cliffs are rare on northerly slopes, which are dominated by mantles of weathered sandstone and colluvium (Burnett et al., 2008, doi:10.1029/2007JF000789). However, in semi-arid regions of the Idaho Batholith, preliminary results indicate some north-facing slopes are significantly steeper than south-facing slopes. We hypothesize that in semi-arid areas with observable increases in vegetation on north vs. south-facing slopes, north-facing slopes will be steeper due to increased soil cohesion, increased capture of wind-borne loess due to vegetative wind-baffling, and differences in the type and magnitude of erosive processes. In moister areas where aspect does not visibly control vegetation type and density, differences in slope angles with aspect should not be observed. We investigate tectonically quiescent regions of the mostly-homogenous granodioritic Idaho Batholith to locate areas sensitive to aspect-induced variations in insolation and compare slope characteristics on north and south-facing slopes. Hillslopes within the Dry Creek Experimental Watershed, in the

  4. Caribou distribution during calving in the northeast National Petroleum Reserve-Alaska, June 1998 to 2000

    Directory of Open Access Journals (Sweden)

    Lynn E. Noel

    2003-04-01

    Full Text Available Barren ground caribou (Rangifer tarandus granti of the Teshekpuk Caribou Herd (TCH inhabit the western portion of Alaska's Arctic Coastal Plain within the National Petroleum Reserve—Alaska (NPR-A. Alaska's North Slope communities, management agencies, and private industry are interested in this herd because of its importance as a subsistence resource and location relative to potential petroleum development. From 1998 through 2000, we monitored caribou distribution during the calving period within the Northeast Planning Area of the NPR-A using systematic strip-transect aerial surveys, as well as VHF and satellite telemetry for cow caribou. Aerial survey and telemetry data indicated cows with calves were distributed around Teshekpuk Lake, with a concentration south of the lake in 1999 and 2000. Inconsistencies in weather conditions, survey timing (both strip-transect and VHF surveys, 100% coverage survey areas, and small sample sizes confound interpretations of our results. However, several patterns were apparent. Later transect survey timing (7—12 June versus 4—7 and 5—8 June resulted in more cow/calf pairs recorded. Our 18% coverage area, originally based on VHF telemetry data for the extent of TCH calving, covered a consistently high proportion (95% to 100% of the annual calving ranges (95% kernel utilization distributions, but accounted for only 24% to 46% of the adult cows in the TCH based on the current Alaska Department of Fish and Game population estimate (1999 and average 1998¬2000 herd composition. It appears that either our transect survey methodology significantly underestimated the true number of caribou cows in the study area, many cows calved outside the area or moved into the area and calved after our surveys, or we have over estimated the number of reproductive cows in the herd. Our 100% coverage transect areas covering oil and gas lease areas, contained 38% of the calving range with 23% of TCH cows in 1999; and 18% of

  5. 陕北黄土区封禁流域坡面微地形植被特征分异%Differentiation of vegetation characteristics on slope micro-topography of fenced watershed in loess area of north Shaanxi Province, Northwest China

    Institute of Scientific and Technical Information of China (English)

    王晶; 朱清科; 秦伟; 张宏芝; 云雷; 谢静; 邝高明

    2012-01-01

    Based on the investigation data of the vegetations in Hegou valley in Wuqi County of Shaanxi Province, this paper studied the vegetation characteristics on the five typical micro-topography categories including shallow gully, gully, collapse, platform, and scarp in the loess area of north Shaanxi, with the undisturbed slope as the control. There existed distinct differences in the species composition, quantitative characteristics, and species diversity of plant communities on the five typical micro-topography categories and the undisturbed slope. After twelve years of enclosure recovery, the study area formed herbaceous plant community, with Artemisia sacrorum and Artemisia giraldii as the dominant species. Among the main companion species, shrubs such as Prinsepia uni-flora and Caragana korshinskii were found in scarp and gully, and hygrophyte Phragmites australis appeared in platform. The coverage, height, and biomass of the plant communities on most of the micro-topography categories, especially on the gully and collapse, were larger than those on the undisturbed slope. The Shannon index on the micro-topography categories and undisturbed slope was in the order of scarp > gully> shallow gully> undisturbed slope> platform> collapse.%以陕西省吴起县合沟流域内微地形及原状坡面的植被调查数据为基础,研究浅沟、切沟、塌陷、缓台和陡坎5种黄土高原典型微地形植被特征及其与原状坡面的差异.结果表明:黄土区封禁流域坡面微地形内植物群落物种组成、数量特征及其多样性存在明显差异.经过12年的自然恢复,研究区域形成以铁杆蒿和茭蒿为优势种的草本群落,伴生种中,陡坎和切沟出现灌木扁核木和柠条,缓台出现湿生性植物芦苇.微地形植被的盖度、平均高度和生物量多优于原状坡面,且以切沟和塌陷最为显著.不同微地形Shannon指数的大小顺序为陡坎>切沟>浅沟>原状坡面>缓台>塌陷.

  6. Bibliography on Alaska estuaries

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This bibliography was compiled to assist in working up “profiles” for the estuaries in Alaska. The purpose of the profiles is to list in a narrative form the...

  7. Alaska waterfowl production, 1964

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Production and Habitat Survey for Alaska during 1964. The primary purpose of the survey is to provide information on duck...

  8. EXTENDED MILD-SLOPE EQUATION

    Institute of Scientific and Technical Information of China (English)

    黄虎; 丁平兴; 吕秀红

    2001-01-01

    The Hamiltonian formalism for surface waves and the mild-slope approximation were empolyed in handling the case of slowly varying three-dimensional currents and an uneven bottom, thus leading to an extended mild-slope equation. The bottom topography consists of two components: the slowly varying component whose horizontal length scale is longer than the surface wave length, and the fast varying component with the amplitude being smaller than that of the surface wave. The frequency of the fast varying depth component is, however, comparable to that of the surface waves. The extended mild- slope equation is more widely applicable and contains as special cases famous mild-slope equations below: the classical mild-slope equation of Berkhoff , Kirby' s mild-slope equation with current, and Dingemans' s mild-slope equation for rippled bed. The extended shallow water equations for ambient currents and rapidly varying topography are also obtained.

  9. Evaluation of the anthropogenic radionuclide concentrations in sediments and fauna collected in the Beaufort Sea and northern Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Efurd, D.W.; Miller, G.G.; Rokop, D.J. [and others

    1997-07-01

    This study was performed to establish a quality controlled data set about the levels of radio nuclide activity in the environment and in selected biota in the U.S. Arctic. Sediment and biota samples were collected by the National Oceanic and Atmospheric Administration (NOAA), the National Biological Service, and the North Slope Borough`s Department of Wildlife Management to determine the impact of anthropogenic radionuclides in the Arctic. The results summarized in this report are derived from samples collected in northwest Alaska with emphasis on species harvested for subsistence in Barrow, Alaska. Samples were analyzed for the anthropogenic radionuclides {sup 90}Sr, {sup 137}Cs, {sup 238}Pu, {sup 239}Pu, {sup 240}Pu and {sup 241}Am. The naturally occurring radionuclides {sup 40}K, {sup 212}Pb and {sup 214}Pb were also measured. One goal of this study was to determine the amounts of anthropogenic radionuclides present in the Beaufort Sea. Sediment samples were isotopically fingerprinted to determine the sources of radio nuclide activities. Biota samples of subsistence and ecological value were analyzed to search for evidence of bio-accumulation of radionuclides and to determine the radiation exposures associated with subsistence living in northern Alaska. The anthropogenic radio nuclide content of sediments collected in the Beaufort Sea was predominantly the result of the deposition of global fallout. No other sources of anthropogenic radionuclides could be conclusively identified in the sediments. The anthropogenic radio nuclide concentrations in fish, birds and mammals were very low. Assuming that ingestion of food is an important pathway leading to human contact with radioactive contaminants and given the dietary patterns in coastal Arctic communities, it can be surmised that marine food chains are presently not significantly affected.

  10. Recurring Slope Lineae in Mid-Latitude and Equatorial Mars

    Science.gov (United States)

    McEwen, A. S.; Dundas, C. M.; Mattson, S.; Toigo, A. D.; Ojha, L.; Wray, J. J.; Chojnacki, M.; Byrne, S.; Murchie, S. L.; Thomas, N.

    2013-12-01

    A key to potential present-day habitability of Mars is the presence of liquid H2O (water). Recurring slope lineae (RSL) could be evidence for the seasonal flow of water on relatively warm slopes. RSL are narrow (250 K to >300 K. In the past year we have monitored active RSL in equatorial (0°-15°S) regions of Mars, especially in the deep canyons of Valles Marineris. They are especially active on north-facing slopes in northern summer and spring and on south-facing slopes in southern spring and summer, following the most normal solar incidence angles on these steep slopes. However, predicted peak temperatures for north-facing slopes are nearly constant throughout the Martian year because orbital periapse occurs near the southern summer solstice. Although warm temperatures and steep low-albedo slopes are required, some additional effect besides temperature may serve to trigger and stop RSL activity. Seasonal variation in the atmospheric column abundance of water does not match the RSL activity. Although seasonal melting of shallow ice could explain the mid-latitude RSL, the equatorial activity requires a different explanation, perhaps migration of briny groundwater. To explain RSL flow lengths, exceeding 1 km in Valles Marineris, the water is likely to be salty. Several RSL attributes are not yet understood: (1) the relation between apparent RSL activity and dustiness of the atmosphere; (2) salt composition and concentration; (3) variability in RSL activity from year to year; (4) seasonal activity on north-facing equatorial slopes in spite of little change in temperature; and (5) temporal changes in the color properties of fans where RSL terminate. Continued orbital monitoring, laboratory experiments, and future orbital and landed exploration with new measurement types are needed. Equatorial water activity, if confirmed, creates new exploration opportunities and challenges. RSL >1 km long near boundary between Eos and Capri Chasmata of Valles Marineris, Mars.

  11. Bedrock geologic map of the northern Alaska Peninsula area, southwestern Alaska

    Science.gov (United States)

    Wilson, Frederic H.; Blodgett, Robert B.; Blome, Charles D.; Mohadjer, Solmaz; Preller, Cindi C.; Klimasauskas, Edward P.; Gamble, Bruce M.; Coonrad, Warren L.

    2017-03-03

    The northern Alaska Peninsula is a region of transition from the classic magmatic arc geology of the Alaska Peninsula to a Proterozoic and early Paleozoic carbonate platform and then to the poorly understood, tectonically complex sedimentary basins of southwestern Alaska. Physiographically, the region ranges from the high glaciated mountains of the Alaska-Aleutian Range to the coastal lowlands of Cook Inlet on the east and Bristol Bay on the southwest. The lower Ahklun Mountains and finger lakes on the west side of the map area show strong effects from glaciation. Structurally, a number of major faults cut the map area. Most important of these are the Bruin Bay Fault that parallels the coast of Cook Inlet, the Lake Clark Fault that cuts diagonally northeast to southwest across the eastern part of the map area, and the presently active Holitna Fault to the northwest that cuts surficial deposits.Distinctive rock packages assigned to three provinces are overlain by younger sedimentary rocks and intruded by widely dispersed latest Cretaceous and (or) early Tertiary granitic rocks. Much of the east half of the map area lies in the Alaska-Aleutian Range province; the Jurassic to Tertiary Alaska-Aleutian Range batholith and derivative Jurassic sedimentary rocks form the core of this province, which is intruded and overlain by the Aleutian magmatic arc. The Lime Hills province, the carbonate platform, occurs in the north-central part of the map area. The Paleozoic and Mesozoic Ahklun Mountains province in the western part of the map area includes abundant chert, argillite, and graywacke and lesser limestone, basalt, and tectonic mélange. The Kuskokwim Group, an Upper Cretaceous turbidite sequence, is extensively exposed and bounds all three provinces in the west-central part of the map area.

  12. Twelve Years of Interviews with the Inupiat people of Arctic Alaska: Report from a Community Workshop

    Science.gov (United States)

    Eisner, W. R.; Hinkel, K. M.; Cuomo, C.

    2015-12-01

    On 20 August 2015, a workshop was held in Barrow, Alaska, which presented the highlights of 12 years of research connecting local indigenous knowledge of landscape processes with scientific research on arctic lakes, tundra changes, and permafrost stability. Seventy-six Iñupiat elders, hunters, and other knowledge-holders from the North Slope villages of Barrow, Atqasuk, Wainwright, Nuiqsut, and Anaktuvuk Pass were interviewed, and over 75 hours of videotaped interviews were produced. The interviews provided information and observations on landforms, lakes, erosion, permafrost degradation and thermokarst, changes in the environment and in animal behavior, human modification of lakes, tundra damage from 4-wheel off-road vehicles, tundra trail expansion, and other phenomena. Community concerns regarding the impact of environmental change on food procurement, animal migration, human travel routes, and the future of subsistence practices were also prominent themes. Following an interview, each videotaped session was logged. Each time an elder pointed to a location on a map and explained a landscape event/observation or told a story, the time-stamp in the video was recorded. Each logged event consisted of a code and a short account of the observation. From these reference sheets, a Geographic Information System (GIS) dataset was created. A logged account for each videotape, with geographic coordinates, event code, and event description is available for each videotape. The goal of the workshop was to report on our findings, thank the community for their support, and collaboratively develop plans for archiving and disseminating this data. A complete video library and searchable, printed and digital issues of the logging dataset for archiving in the communities were also produced. Discussions with administrative personnel at the Tuzzy Library in Barrow and the Inupiat Heritage Center have enabled us to set standards and develop a timeline for turning over the library of

  13. Polar Gateways Arctic Circle Sunrise Conference 2008, Barrow, Alaska: IHY-IPY Outreach on Exploration of Polar and Icy Worlds in the Solar System

    Science.gov (United States)

    Cooper, John F.; Kauristie, Kirsti; Weatherwax, Allan T.; Sheehan, Glenn W.; Smith, Roger W.; Sandahl, Ingrid; Ostgaard, Nikolai; Chernouss, Sergey; Thompson, Barbara J.; Peticolas, Laura; Moore, Marla H.; Senske, David A.; Tamppari, Leslie K.; Lewis, Elaine M.

    2008-01-01

    Polar, heliophysical, and planetary science topics related to the International Heliophysical and Polar Years 2007-2009 were addressed during this circumpolar video conference hosted January 23-29, 2808 at the new Barrow Arctic Research Center of the Barrow Arctic Science Consortium in Barrow, Alaska. This conference was planned as an IHY-IPY event science outreach event bringing together scientists and educational specialists for the first week of sunrise at subzero Arctic temperatures in Barrow. Science presentations spanned the solar system from the polar Sun to Earth, Moon, Mars, Jupiter, Saturn, and the Kuiper Belt. On-site participants experienced look and feel of icy worlds like Europa and Titan by being in the Barrow tundra and sea ice environment and by going "on the ice" during snowmobile expeditions to the near-shore sea ice environment and to Point Barrow, closest geographic point in the U.S. to the North Pole. Many science presentations were made remotely via video conference or teleconference from Sweden, Norway, Russia, Canada, Antarctica, and the United States, spanning up to thirteen time zones (Alaska to Russia) at various times. Extensive educational outreach activities were conducted with the local Barrow and Alaska North Slope communities and through the NASA Digital Learning Network live from the "top of the world" at Barrow. The Sun- Earth Day team from Goddard, and a videographer from the Passport to Knowledge project, carried out extensive educational interviews with many participants and native Inupiaq Eskimo residents of Barrow. Video and podcast recordings of selected interviews are available at http://sunearthday.nasa.gov/2008/multimedidpodcasts.php. Excerpts from these and other interviews will be included in a new high definition video documentary called "From the Sun to the Stars: The New Science of Heliophysics" from Passport to Knowledge that will later broadcast on NASA TV and other educational networks. Full conference

  14. Multistage petroleum charges in the Silurian of Tazhong north slope of the Tarim basin, northwest China: evidence from fluid inclusions and organic geochemistry%中国塔里木盆地塔中北坡志留系多期石油充注:流体包裹体和有机地球化学证据

    Institute of Scientific and Technical Information of China (English)

    潘立银; 倪培; 欧光习; 李林强

    2007-01-01

    Well S provides a good opportunity to investigate the petroleum filling history in Tazhong North Slope. Petrographic investigations suggest that bitumen, oil, and petroleum inclusions coexist in Silurian sandstones from well S, reflecting a complicated reservoir filling history in the study area. Integration of organic geochemistry and fluid inclusion analysis shows that the Silurian reservoir has experienced three episodes of petroleum charge, that is from the late Silurian to the early Devonian, the early-middle Triassic and the Paleogene, respectively. The present-day reservoir fluids in the Silurian are the mixtures generated in multiple (at least two) episodes of petroleum charge. The oil charging into Silurian resevior in the early period had experienced considerable degradation, and was mixed with later non-degraded oil.

  15. Slope Morphology of Twin Peaks, Mars Pathfinder Landing Site

    Science.gov (United States)

    Hobbs, Steven; Paine, Colin; Clarke, Jon; Caprarelli, Graziella

    2010-05-01

    Development of slope form over time has long been a concern of geomorphologists, although recently this concern has been moved to slope processes rather than form. There are two basic approaches. The first is theoretical, involving modeling of different types and rates of processes, and calculation of results in terms of slope evolution over time. Comparisons with real-life slopes can follow this approach [1], [2]. The second, inductive, approach involves field measurements to test ideas about slope evolution starting from the assumption that observed slopes represent different stages of an essentially similar evolution [3]. Space is substituted for time, and a number of slopes, assumed to be of increasing age, are measured and placed in an evolutionary sequence (e.g. [4], [5], [6]). [5] showed that slope angles are modally distributed, with the modal angles controlled by the materials (regolith) of which the slopes are formed, and by the processes operating on them. Data can be obtained directly from field work or from digital elevation models (DEM) derived from remote sensing investigations [7]. DEMs are particularly useful to study inaccessible planets, such as Mars, where on site observations are restricted to only a few landing sites. Here we present a study of slopes on the Twin Peaks, two small hills located 780 m north and 910 m south of the Mars Pathfinder landing site at the mouth of the Ares and Tiu flood channels. The presence of streamlined hills, jumbled surfaces and conglomerates suggested the region was modified by massive flooding 1.8 - 3.5 billion years ago [8], [9]. The streamlined forms and terraces of the Twin Peaks were taken to indicate catastrophic flood conditions that were believed to be prevalent in the area [8]. It was also suggested that the northernmost peak was topped by floodwater, causing its flatter appearance. Other researchers postulated alternative geomorphological origins for the features observed at the Pathfinder landing site

  16. Regional Fluid Flow and Basin Modeling in Northern Alaska

    Science.gov (United States)

    Kelley, Karen D.

    2007-01-01

    INTRODUCTION The foothills of the Brooks Range contain an enormous accumulation of zinc (Zn) in the form of zinc sulfide and barium (Ba) in the form of barite in Carboniferous shale, chert, and mudstone. Most of the resources and reserves of Zn occur in the Red Dog deposit and others in the Red Dog district; these resources and reserves surpass those of most deposits worldwide in terms of size and grade. In addition to zinc and lead sulfides (which contain silver, Ag) and barite, correlative strata host phosphate deposits. Furthermore, prolific hydrocarbon source rocks of Carboniferous and Triassic to Early Jurassic age generated considerable amounts of petroleum that may have contributed to the world-class petroleum resources of the North Slope. Deposits of Zn-Pb-Ag or barite as large as those in the Brooks Range are very rare on a global basis and, accordingly, multiple coincident favorable factors must be invoked to explain their origins. To improve our understanding of these factors and to contribute to more effective assessments of resources in sedimentary basins of northern Alaska and throughout the world, the Mineral Resources Program and the Energy Resources Program of the U.S. Geological Survey (USGS) initiated a project that was aimed at understanding the petroleum maturation and mineralization history of parts of the Brooks Range that were previously poorly characterized. The project, titled ?Regional Fluid Flow and Basin Modeling in Northern Alaska,? was undertaken in collaboration with industry, academia, and other government agencies. This Circular contains papers that describe the results of the recently completed project. The studies that are highlighted in these papers have led to a better understanding of the following: *The complex sedimentary facies relationships and depositional settings and the geochemistry of the sedimentary rocks that host the deposits (sections 2 and 3). *The factors responsible for formation of the barite and zinc deposits

  17. National assessment of shoreline change: a GIS compilation of vector shorelines and associated shoreline change data for the north coast of Alaska, U.S.-Canadian border to Icy Cape

    Science.gov (United States)

    Gibbs, Ann E.; Karen A. Ohman,; Richmond, Bruce M.

    2015-01-01

    The Arctic Coastal Plain of northern Alaska is an area of strategic economic importance to the United States, is home to remote Native communities, and encompasses unique habitats of global significance. Coastal erosion along the Arctic coast is chronic, widespread, and may be accelerating, which threatens defense- and energy-related infrastructure, natural shoreline habitats, and Native communities. There is an increased demand for accurate information regarding past and present shoreline changes across the United States. To meet these national needs, the Coastal and Marine Geology Program of the U.S. Geological Survey is compiling existing reliable historical shoreline data along sandy shores of the conterminous United States and parts of Alaska and Hawaii under the National Assessment of Shoreline Change Project (hereafter referred to as the "National Assessment project";http://coastal.er.usgs.gov/shoreline-change/). A comprehensive database of digital vector shorelines and rates of shoreline change for Alaska, from the U.S.-Canadian border to Icy Cape, is presented in this report as part of the National Assessment project.

  18. Seasonal thaw settlement at drained thermokarst lake basins, Arctic Alaska

    Science.gov (United States)

    Liu, Lin; Schaefer, Kevin; Gusmeroli, Alessio; Grosse, Guido; Jones, Benjamin M.; Zhang, Tinjun; Parsekian, Andrew; Zebker, Howard

    2014-01-01

    Drained thermokarst lake basins (DTLBs) are ubiquitous landforms on Arctic tundra lowland. Their dynamic states are seldom investigated, despite their importance for landscape stability, hydrology, nutrient fluxes, and carbon cycling. Here we report results based on high-resolution Interferometric Synthetic Aperture Radar (InSAR) measurements using space-borne data for a study area located on the North Slope of Alaska near Prudhoe Bay, where we focus on the seasonal thaw settlement within DTLBs, averaged between 2006 and 2010. The majority (14) of the 18 DTLBs in the study area exhibited seasonal thaw settlement of 3–4 cm. However, four of the DTLBs examined exceeded 4 cm of thaw settlement, with one basin experiencing up to 12 cm. Combining the InSAR observations with the in situ active layer thickness measured using ground penetrating radar and mechanical probing, we calculated thaw strain, an index of thaw settlement strength along a transect across the basin that underwent large thaw settlement. We found thaw strains of 10–35% at the basin center, suggesting the seasonal melting of ground ice as a possible mechanism for the large settlement. These findings emphasize the dynamic nature of permafrost landforms, demonstrate the capability of the InSAR technique to remotely monitor surface deformation of individual DTLBs, and illustrate the combination of ground-based and remote sensing observations to estimate thaw strain. Our study highlights the need for better description of the spatial heterogeneity of landscape-scale processes for regional assessment of surface dynamics on Arctic coastal lowlands.

  19. Rock slope instabilities in Norway: First systematic hazard and risk classification of 22 unstable rock slopes

    Science.gov (United States)

    Böhme, Martina; Hermanns, Reginald L.; Oppikofer, Thierry; Penna, Ivanna

    2016-04-01

    average displacement rates of up to 6 cm are measured with differential GNSS and InSAR. Cosmogenic nuclide dating suggests an acceleration of the present displacement compared to the average displacement since the initiation of the gravitational movement approximately 7000 years ago. Furthermore, there exists a pre-historic rock avalanche 3 km north along the same slope. These characteristics result in a very high hazard for the Gamanjunni unstable rock slope. The consequence analyses focus on the possibility of life loss only. For this the number of persons in the area that can be affected by either the rock slope failure itself and/or its secondary consequence of a displacement wave in case that a rock slope failure would hit a water body is estimated. For Gamanjunni the direct consequences are approximately 40 casualties, representing medium consequences. A total of 48 scenarios were finally analyzed for hazard, consequences and risk. The results are plotted in a risk matrix with 5 hazard and 5 consequence classes, leading to 4 risk classes. One unstable rock slope was classified as very high hazard, 9 scenarios as high hazard, 25 as medium hazard and 13 as low hazard, while none were classified as very low hazard. The consequence analyses for those scenarios resulted in 5 scenarios with very high consequences (>1000 potential casualties), 13 scenarios with high consequences (100-1000 casualties), 9 scenarios with medium consequences (10-100 casualties), 6 scenarios with low consequences (1-10 casualties) and 15 scenarios with very low consequences (0-1 casualties). This resulted in a high risk for 6 scenarios, medium to high risk for 16 scenarios, medium risk for 7 scenarios and low risk for 19 scenarios. These results allow determining which unstable rock slopes do not require further follow-up and on which further investigations and/or mitigation measures should be considered.

  20. Tertiary thrust systems and fluid flow beneath the Beaufort coastal plain (1002 area), Arctic National Wildlife Refuge, Alaska, U.S.A.

    Science.gov (United States)

    Potter, Christopher J.; Grow, John A.; Perry, William J.; Moore, Thomas E.; O'Sullivan, Paul B.; Phillips, Jeffrey D.; Saltus, Richard W.

    2004-01-01

    Beneath the Arctic coastal plain (commonly referred to as "the 1002 area") in the Arctic National Wildlife Refuge, northeastern Alaska, United States, seismic reflection data show that the northernmost and youngest part of the Brookian orogen is preserved as a Paleogene to Neogene system of blind and buried thrust-related structures. These structures involve Proterozoic to Miocene (and younger?) rocks that contain several potential petroleum reservoir facies. Thermal maturity data indicate that the deformed rocks are mature to overmature with respect to hydrocarbon generation. Oil seeps and stains in outcrops and shows in nearby wells indicate that oil has migrated through the region; geochemical studies have identified three potential petroleum systems. Hydrocarbons that were generated from Mesozoic source rocks in the deformed belt were apparently expelled and migrated northward in the Paleogene, before much of the deformation in this part of the orogen. It is also possible that Neogene petroleum, which was generated in Tertiary rocks offshore in the Arctic Ocean, migrated southward into Neogene structural traps at the thrust front. However, the hydrocarbon resource potential of this largely unexplored region of Alaska's North Slope remains poorly known.

  1. Research on the slope spectrum of the Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A new concept dealing with digital analysis of loess terrain,slope spectrum,is presented and discussed in this paper,by introducing its characteristic,represen-tation and extracting method from DEMs. Using 48 geomorphological units in dif-ferent parts of the loess as test areas and 5 m-resolution DEMs as original test data,the quantitative depiction and spatial distribution of slope spectrum in China’s Loess Plateau have been studied on the basis of a series of carefully-designed experiments. In addition,initial experiment indicates a strong relationship between the slope spectrum and the loess landform types,displaying a potential importance of the slope spectrum in geomorphological studies. Based on the slope spectrums derived from the 25 m-resolution DEM data in whole loess terrain in northern part of Shaanxi,13 slope spectrum indices were extracted and integrated into a compre-hensive layer with image integration method. Based on that,a series of unsuper-vised classifications was applied in order to make a landform classification in northern Shaanxi Loess Plateau. Experimental results show that the slope spec-trum analysis is an effective method in revealing the macro landform features. A continuous change of slope spectrum from south to north in northern Shaanxi Loess Plateau shows an obvious spatial distribution of different loess landforms. This also proves the great significance of the slope spectrum method in describing the terrain roughness and landform evolution as well as a further understanding on landform genesis and spatial distribution rule of different landforms in the Loess Plateau.

  2. ElevationSlope_SLOPE1p6M

    Data.gov (United States)

    Vermont Center for Geographic Information — This metadata applies to the following collection area(s): Addison County 2012 1.6m; Missisquoi Upper 2010 1.6m; Missisquoi Lower 2008 1.6m and related SLOPE...

  3. Submarine landslides along the eastern Mediterranean Israeli continental slope

    Science.gov (United States)

    Reuven, Einav; Katz, Oded; Aharonov, Einat

    2013-04-01

    Numerous shallow submarine slope failures (scars and deposits) are observed in recent high resolution bathymetric grids of the continental slope off the Israeli eastern Mediterranean coast. The nature of these slope failures is currently not comprehensively understood as well as the question of whether the eastern Mediterranean continental slope is continuously or episodically unstable. We report here first steps towards understanding the present state of this submarine landslide system, which include mapping and analyzing the geology of the landslides and the hosting slopes. The continental slope extends from water depths of about 150 to more than 1000 meters with a slope of less than 5 degrees in general. Bathymetric grids with pixel resolution of 15 m till water depth of 700 m and 50 m till water depth of 1700 m were used. Analyzing the bathymetry revealed three main submarine surface features: (a) numerous shallow landslides, within the upper sequence of the post-Messenian sediments. Landslide widths range between hundreds to thousand of meters at the scar, with scar heights up to hundred meters. The toes of the landslides are not always mapable and lay up to a few kilometers down slope from the scar. Slope angles within the scars are 5 to more than15 degrees. At least two types of landslides were detected: presumably young slides with sharp scars, and presumably old slides with secondary slides and secondary drainage systems developed within the scar area; (b) a few kilometers long, north striking step-like lineaments. Step heights are up to 100 meters and the slopes are up to 20 degrees. The offset between parallel steps is less than a kilometer to a few kilometers. The steps are interpreted as surface expressions of growth faults rooted at the Messinian evaporates up to 1.5 kilometers below surface; (c) a few north striking channels were also detected with steep walls of more than 15 degrees, up to two kilometers width and a few kilometers length. The nature

  4. Venetie, Alaska energy assessment.

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Richard Pearson; Baca, Michael J.; Schenkman, Benjamin L.; Brainard, James Robert

    2013-07-01

    This report summarizes the Energy Assessment performed for Venetie, Alaska using the principals of an Energy Surety Microgrid (ESM) The report covers a brief overview of the principals of ESM, a site characterization of Venetie, a review of the consequence modeling, some preliminary recommendations, and a basic cost analysis.

  5. Current Ethnomusicology in Alaska.

    Science.gov (United States)

    Johnston, Thomas F.

    The systematic study of Eskimo, Indian, and Aleut musical sound and behavior in Alaska, though conceded to be an important part of white efforts to foster understanding between different cultural groups and to maintain the native cultural heritage, has received little attention from Alaskan educators. Most existing ethnomusical studies lack one or…

  6. Asthma and American Indians/Alaska Natives

    Science.gov (United States)

    ... Minority Population Profiles > American Indian/Alaska Native > Asthma Asthma and American Indians/Alaska Natives In 2014, 218, ... Native American adults reported that they currently have asthma. American Indian/Alaska Native children are 30% more ...

  7. Synoptic-scale fire weather conditions in Alaska

    Science.gov (United States)

    Hayasaka, Hiroshi; Tanaka, Hiroshi L.; Bieniek, Peter A.

    2016-09-01

    Recent concurrent widespread fires in Alaska are evaluated to assess their associated synoptic-scale weather conditions. Several periods of high fire activity from 2003 to 2015 were identified using Moderate Resolution Imaging Spectroradiometer (MODIS) hotspot data by considering the number of daily hotspots and their continuity. Fire weather conditions during the top six periods of high fire activity in the fire years of 2004, 2005, 2009, and 2015 were analyzed using upper level (500 hPa) and near surface level (1000 hPa) atmospheric reanalysis data. The top four fire-periods occurred under similar unique high-pressure fire weather conditions related to Rossby wave breaking (RWB). Following the ignition of wildfires, fire weather conditions related to RWB events typically result in two hotspot peaks occurring before and after high-pressure systems move from south to north across Alaska. A ridge in the Gulf of Alaska resulted in southwesterly wind during the first hotspot peak. After the high-pressure system moved north under RWB conditions, the Beaufort Sea High developed and resulted in relatively strong easterly wind in Interior Alaska and a second (largest) hotspot peak during each fire period. Low-pressure-related fire weather conditions occurring under cyclogenesis in the Arctic also resulted in high fire activity under southwesterly wind with a single large hot-spot peak.

  8. Seismicity of the Earth 1900-2013 offshore British Columbia-southeastern Alaska and vicinity

    Science.gov (United States)

    Hayes, Gavin P.; Smoczyk, Gregory M.; Ooms, Jonathan G.; McNamara, Daniel E.; Furlong, Kevin P.; Benz, Harley M.; Villaseñor, Antonio

    2014-01-01

    The tectonics of the Pacific margin of North America between Vancouver Island and south-central Alaska are dominated by the northwest motion of the Pacific plate with respect to the North America plate at a velocity of approximately 50 mm/yr. In the south of this mapped region, convergence between the northern extent of the Juan de Fuca plate (also known as the Explorer microplate) and North America plate dominate. North from the Explorer, Pacific, and North America plate triple junction, Pacific:North America motion is accommodated along the ~650-km-long Queen Charlotte fault system. Offshore of Haida Gwaii and to the southwest, the obliquity of the Pacific:North America plate motion vector creates a transpressional regime, and a complex mixture of strike-slip and convergent (underthrusting) tectonics. North of the Haida Gwaii islands, plate motion is roughly parallel to the plate boundary, resulting in almost pure dextral strike-slip motion along the Queen Charlotte fault. To the north, the Queen Charlotte fault splits into multiple structures, continuing offshore of southwestern Alaska as the Fairweather fault, and branching east into the Chatham Strait and Denali faults through the interior of Alaska. The plate boundary north and west of the Fairweather fault ultimately continues as the Alaska-Aleutians subduction zone, where Pacific plate lithosphere subducts beneath the North America plate at the Aleutians Trench. The transition is complex, and involves intraplate structures such as the Transition fault. The Pacific margin offshore British Columbia is one of the most active seismic zones in North America and has hosted a number of large earthquakes historically.

  9. Bentonite debris flows in northern alaska.

    Science.gov (United States)

    Anderson, D M; Reynolds, R C; Brown, J

    1969-04-11

    Seasonal freezing and thawing and the extreme cold of the arctic lead to the development of a variety of characteristic geomorphic features. A new one, bentonite debris flow channels, has been identified near Umiat, Alaska. These flows form when bentonite-rich Cretaceous Shales are exposed to Surface water on slopes of 5 to 30 degrees. The characteristic landform developed is a U-shaped channel 1 to 2 meters deep and from 8 to 10 meters in width. The channel shows a fluted floor and walls and is commonly flanked by a levee. The flow material is appa rently derived from the entire surface of the head portions of associated gullies. When this surface layer hydrates during snowmelt and runoff or during prolonged rain, the bentonite imbibes water and swells to a point at which its viscosity is lowered sufficiently to initiate creep or viscous flow.

  10. North Pacific right whale aerial surveys conducted in the southeastern Bering Sea by the Alaska Fisheries Scientific Center, National Marine Mammal Laboratory from 2008-07-24 to 2009-08-25 (NCEI Accession 0135767)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — As part of an inter-agency agreement between the National Marine Mammal Laboratory and the Bureau of Ocean Energy Management, aerial surveys of the North Aleutian...

  11. Sedimentological processes in a scarp-controlled rocky shoreline to upper continental slope environment, as revealed by unusual sedimentary features in the Neogene Coquimbo Formation, north-central Chile

    Science.gov (United States)

    Le Roux, J. P.; Gómez, Carolina; Fenner, Juliane; Middleton, Heather

    2004-03-01

    Exceptionally good outcrops of Miocene to Pliocene deposits in the vicinity of submarine Paleozoic basement scarps at Carrizalillo, north of La Serena, reveal a wealth of sedimentary features not commonly observed. The most proximal facies consist of rock fall and coarse-grained debris flow deposits directly abutting the basement wall from which they originated. Angular basement clasts are mixed with well-rounded cobbles, which probably formed as a basal gravel on a wave-cut platform at the beginning of marine flooding, subsequently accumulated at the scarp edge and were incorporated into the debris when the latter collapsed. The poor sorting, inverse grading, and protruding cobbles and boulders are classical debris flow features, with good clast imbrication indicating a laminar shearing action. A medial facies is represented by secondary channels running parallel to the major scarp about 1 km downslope of the first locality. In the largest channel, megaflutes at the base indicate the passage of highly turbulent, nondepositing flows eroding the soft, silty substrate. In the deepest, central part of the channel, a pebbly coquina shows horizontal and trough cross-stratification, with most of the bivalves oriented convex side up. Meter-scale rip-up clasts of the underlying siltstone are also present, indicating turbulent flow with a density sufficiently high to retard settling. The coquina is interpreted as a detachment deposit resulting from a hydroplaning debris flow along the central part of the channel, where the velocity and rate of pore pressure decay were highest. This deposit is overlain by fining upward, massive to horizontally stratified sandstone very similar in texture and composition to the matrix of the debris flow, suggesting its formation by surface transformation and elutriation of the latter. Along the channel margin, a basal centimeter-scale sandstone layer is virtually unaffected by the megaflute topography and clearly represents a subsequent event

  12. Multi-method Assessment of the Braided Planform Stability - Toklat River, Alaska

    Science.gov (United States)

    Adema, G. W.; Podolak, C.

    2011-12-01

    Maintaining infrastructure in the vicinity of a dynamic braided river is a challenging, yet necessary activity in Alaska and it requires some understanding of likely future river planform configurations. The intersection of the 150-kilometer-long gravel road which carries all of the traffic in the Denali National Park, AK, with the Toklat River, draining the north side of the glaciated Alaska Range, highlights several of these challenges. Immediately downstream from two bridges and a causeway crossing the 800-meter-wide braid plain, park infrastructure (a rest stop and a maintenance facility) is being threatened by bank erosion. In order to better protect this section of the park the National Park Service sought a geomorphic assessment of the Toklat River from the USGS. The assessment of likely planform configurations was conducted with a four-method approach - analyzing 1) channel patterns in the downstream direction, 2) changes in the lateral slope of the braidplain over time, 3) influences on the geometry of a significant tributary junction, and 4) probable post-avulsion channel configurations. This suite of analyses based on a series of cross section surveys and a large airborne LiDAR dataset were carried out using MATLAB, Quick Terrain Modeler, and ArcGIS. Patterns in the down- and cross-valley slopes, the braid plain width, and the cross-sectional forms demonstrate persistent forcings on the channel planform. Temporal trends in the cross section surveys, photographic evidence, and vegetation patterns show a braidplain that is regularly reworked. Relative discharge was estimated from two basins using a USGS-developed empirical method. The discharge was used along with confluence geometry constrain likely planform patterns downstream of a significant tributary junction. A simple momentum-based model showed a likely persistence of the current planform. The LiDAR-derived topography was used in a probabilistic analysis of likely avulsion scenarios and the likely

  13. Silurian Gastropoda from the Alexander terrane, southeast Alaska

    Science.gov (United States)

    Rohr, D.M.; Blodgett, R.B.

    2008-01-01

    Gastropods are described from Ludlow-age strata of the Heceta Limestone on Prince of Wales Island, southeast Alaska. They are part of a diverse megabenthic fauna of the Alexander terrane, an accreted terrane of Siberian or Uralian affinities. Heceta Limestone gastropods with Uralian affinities include Kirkospira glacialis, which closely resembles "Pleurotomaria" lindstromi Oehlert of Chernyshev, 1893, Retispira cf. R. volgulica (Chernyshev, 1893), and Medfracaulus turriformis (Chernyshev, 1893). Medfracaulus and similar morphotypes such as Coelocaulus karlae are unknown from rocks that are unquestionably part of the North American continent (Laurentia) during Late Silurian time. Beraunia is previously known only from the Silurian of Bohemia. Pachystrophia has previously been reported only from western North American terranes (Eastern Klamath, York, and Farewell terranes) and Europe. Bathmopterus Kirk, 1928, is resurrected and is only known from the Silurian of southeast Alaska. Newly described taxa include Hecetastoma gehrelsi n. gen. and n. sp. and Baichtalia tongassensis n. gen. and n. sp. ??2008 The Geological Society of America.

  14. Slope stability hazard management systems

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Weather-related geo-hazards are a major concern for both natural slopes and man-made slopes and embankments.Government agencies and private companies are increasingly required to ensure that there is adequate protection of sloping surfaces in order that interaction with the climate does not produce instability. Superior theoretical formulations and computer tools are now available to address engineering design issues related to the near ground surface soil-atmospheric interactions. An example is given in this paper that illustrates the consequences of not paying adequate attention to the hazards of slope stability prior to the construction of a highway in South America. On the other hand, examples are given from Hong Kong and Mainland China where significant benefits are derived from putting in place a hazard slope stability management system. Some results from a hazard management slope stability study related to the railway system in Canada are also reported. The study took advantage of recent research on unsaturated soil behaviour and applied this information to real-time modelling of climatic conditions. The quantification of the water balance at the ground surface, and subsequent infiltration, is used as the primary tool for hazard level assessment. The suggested hazard model can be applied at either specific high risk locations or in a more general, broad-based manner over large areas. A more thorough understanding of unsaturated soil behaviour as it applies to near ground surface soils,along with the numerical computational power of the computer has made it possible for new approaches to be used in slope hazard management engineering.

  15. Salinity data from moored current meter casts in the Northeast Pacific Ocean, Bering Sea, and Gulf of Alaska from 03 October 1984 - 01 May 1988 (NODC Accession 8900056)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Salinity data were collected using moored current meter casts in the North Pacific Ocean, Bering Sea, and Gulf of Alaska from October 3, 1984 to May 1, 1988. Data...

  16. The seismic structure of southeast Alaska

    Science.gov (United States)

    Bauer, Mark

    The convergent motion of the Pacific and North American Plates in Alaska has produced geologic features associated with subduction zones and has transported displaced terranes along the Queen Charlotte-Fairweather fault system that forms the northeastern boundary of the Pacific Plate. These subduction features stop abruptly at the edge of the Yakutat Block displaced terrane, approximately 300 km from the Queen Charlotte-Fairweather fault. The purpose of this study was to determine the type and geometry of the boundary between the Yakutat Block and North American as well as the cause of the offset volcanic arc and missing Wadati-Benioff zone. I calculated P and S-wave receiver functions for 57 broadband seismic stations located in southeast Alaska. S-wave data was migrated using a Common Conversion Point procedure. P-wave data was imaged via a three-dimensional, pre-stack migration using plane-wave decomposition weighted by an inverse generalized Radon transform to calculate the scattering potential for each event. I also calculated the temperatures at the top of the Yakutat slab and mantle wedge using three different analytical thermal models. The 3-D images and animations I produced show that the Yakutat Block is being subducted, continuous with the Pacific slab, and extends to the Queen Charlotte-Fairweather strike-slip fault systems. The subducted slab extends north to the Wrangell Volcanic Field with a dip than increases gradually from 10° in the west to 15° in the east, stripping approximately 15 km of overlying sediments. The location of the Wrangell Volcanic Field and lack of Wadati-Benioff zone are consistent with the temperatures I calculated for the top of slab and mantle wedge after stripping 15 km of sediment.

  17. Malaspina Glacier, Alaska as seen from STS-66 Atlantis

    Science.gov (United States)

    1994-01-01

    Malaspina Glacier can be seen in this north-northeastern photograph taken in November, 1994. The glacier, located in the south shore of Alaska is a classic example of a piedmont glacier lying along the foot of a mountain range. The principal source of ice for the glacier is provided by the Seward Ice Field to the north (top portion of the view) which flows through three narrow outlets onto the coastal plain. The glacier moves in surges that rush earlier-formed moraines outward into the expanding concentric patterns along the flanks of the ice mass.

  18. ElevationSlope_SLOPE0p7M

    Data.gov (United States)

    Vermont Center for Geographic Information — This metadata applies to the following collection area(s): Windham County 2015 0.7m; Eastern VT 2014 0.7m; Rutland/GI Counties 2013 0.7m and related SLOPE datasets....

  19. Sedimentology, conodonts, structure, and correlation of Silurian and Devonian metasedimentary rocks in Denali National Park, Alaska: A section in Geologic studies in Alaska by the U.S. Geological Survey, 1996

    Science.gov (United States)

    Dumoulin, Julie A.; Bradley, Dwight C.; Harris, Anita G.

    1998-01-01

    presumably are the product of Mesozoic plate convergence.Deep-water rocks of Silurian age have been recognized in six Alaskan terranes outside the Farewell terrane. Comparison of unit DOs with coeval strata in these terranes reveals closest sedimentologic and biostratigraphic similarities with rocks of east-central Alaska (Livengood terrane) and western Alaska (Seward terrane) and less striking similarities with rocks in southeastern Alaska (Alexander terrane) and northern Alaska (Hammond subterrane of Arctic Alaska terrane). Coeval sequences in easternmost Alaska (Porcupine and Tatonduk terranes) correlate least well with DOs because they lack both Silurian siliciclastic turbidites and Upper Devonian platform carbonate rocks. Our correlations permit the interpretation that all Alaskan terranes with Silurian deep-water strata originated along or adjacent to the North American continental margin, but imply a gradient in Silurian turbidite distribution along this margin. Volcanic material preserved in DOs and related rocks may have been derived from the island arc represented by the Alexander terrane.

  20. Investigation of gas hydrate-bearing sandstone reservoirs at the "Mount Elbert" stratigraphic test well, Milne Point, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Boswell, R.M.; Hunter, R. (ASRC Energy Services, Anchorage, AK); Collett, T. (USGS, Denver, CO); Digert, S. (BP Exploration (Alaska) Inc., Anchorage, AK); Hancock, S. (RPS Energy Canada, Calgary, Alberta, Canada); Weeks, M. (BP Exploration (Alaska) Inc., Anchorage, AK); Mt. Elbert Science Team

    2008-01-01

    In February 2007, the U.S. Department of Energy, BP Exploration (Alaska), Inc., and the U.S. Geological Survey conducted an extensive data collection effort at the "Mount Elbert #1" gas hydrates stratigraphic test well on the Alaska North Slope (ANS). The 22-day field program acquired significant gas hydrate-bearing reservoir data, including a full suite of open-hole well logs, over 500 feet of continuous core, and open-hole formation pressure response tests. Hole conditions, and therefore log data quality, were excellent due largely to the use of chilled oil-based drilling fluids. The logging program confirmed the existence of approximately 30 m of gashydrate saturated, fine-grained sand reservoir. Gas hydrate saturations were observed to range from 60% to 75% largely as a function of reservoir quality. Continuous wire-line coring operations (the first conducted on the ANS) achieved 85% recovery through 153 meters of section, providing more than 250 subsamples for analysis. The "Mount Elbert" data collection program culminated with open-hole tests of reservoir flow and pressure responses, as well as gas and water sample collection, using Schlumberger's Modular Formation Dynamics Tester (MDT) wireline tool. Four such tests, ranging from six to twelve hours duration, were conducted. This field program demonstrated the ability to safely and efficiently conduct a research-level openhole data acquisition program in shallow, sub-permafrost sediments. The program also demonstrated the soundness of the program's pre-drill gas hydrate characterization methods and increased confidence in gas hydrate resource assessment methodologies for the ANS.

  1. Shoreline type and subsurface oil persistence in the Exon Valdez spill zone of Prince William Sound, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Page, D.S. [Bowdoin College, Brunswick, ME (United States). Dept. of Chemistry; Boehm, P.D. [Exponent Inc., Maynard, MA (United States); Neff, J.M. [Neff and Associates, Duxbury, MA (United States)

    2008-07-01

    The grounding of the Exxon Valdez in Prince William Sound (PWS), Alaska in the spring of 1989 resulted in the release of 258,000 barrels of Alaska North Slope crude oil into the marine environment. Nearly 800 km of shoreline were oiled to some degree. There was an unprecedented oil spill cleanup effort following the spill. The shoreline surveys of the spill zone were synthesized in this paper in an effort to demonstrate the relationship between shoreline type and persistence of subsurface oil (SSO) residues. Shoreline surveys of surface and SSO indicate rapid initial oil loss with a decline from about 800 linear km of PWS shoreline in 1989 to about 10 km of oiled shoreline in 1992. The period of rapid loss was attributed to natural physical process, biodegradation and cleanup activities that removed accessible spill remnants from shorelines. This was followed by a slower natural average loss rate for less accessible surface and SSO deposits of about 22 per cent per year for the period 1992-2001. This paper emphasized that shoreline type plays a key role in determining SSO persistence. The geology of PWS is complex. Many of the shorelines where SSO persists have armouring layers composed of hard, dense clasts, such as the quartzite boulders and cobblestones that can protect SSO deposits. Eighteen years after the spill, persistent SSO deposits in PWS shorelines remain protected from tidal water-washing and biodegradation by a surface boulder/cobble armour and low sediment porosity. The SSO deposits are in a physical/chemical form and location where they do not pose a health risk to intertidal biological communities and animals. The surveys continue to substantiate that remaining SSO deposits in PWS continue to degrade and go away slowly. 37 refs., 5 tabs., 7 figs.

  2. Contemporary fault mechanics in southern Alaska

    Science.gov (United States)

    Kalbas, James L.; Freed, Andrew M.; Ridgway, Kenneth D.

    Thin-shell finite-element models, constrained by a limited set of geologic slip rates, provide a tool for evaluating the organization of contemporary faulting in southeastern Alaska. The primary structural features considered in our analysis are the Denali, Duke River, Totschunda, Fairweather, Queen Charlotte, and Transition faults. The combination of fault configurations and rheological properties that best explains observed geologic slip rates predicts that the Fairweather and Totschunda faults are joined by an inferred southeast-trending strike-slip fault that crosses the St. Elias Mountains. From a regional perspective, this structure, which our models suggest slips at a rate of ˜8 mm/a, transfers shear from the Queen Charlotte fault in southeastern Alaska and British Columbia northward to the Denali fault in central Alaska. This result supports previous hypotheses that the Fairweather-Totschunda connecting fault constitutes a newly established northward extension of the Queen Charlotte-Fairweather transform system and helps accommodate right-lateral motion (˜49 mm/a) of the Pacific plate and Yakutat microplate relative to stable North America. Model results also imply that the Transition fault separating the Yakutat microplate from the Pacific plate is favorably oriented to accommodate significant thrusting (23 mm/a). Rapid dip-slip displacement on the Transition fault does not, however, draw shear off of the Queen Charlotte-Fairweather transform fault system. Our new modeling results suggest that the Totschunda fault, the proposed Fairweather-Totschunda connecting fault, and the Fairweather fault may represent the youngest stage of southwestward migration of the active strike-slip deformation front in the long-term evolution of this convergent margin.

  3. Plant Functional Types and Their Impact Environmental Factors in a Naturally Recovered Poplar-birch Woodland on the North Slope of Qilian Mountains, China%祁连山北坡自然恢复杨桦林地植物功能型组成及其影响因素

    Institute of Scientific and Technical Information of China (English)

    石福习; 赵成章; 任珩; 周伟; 高福元; 盛亚萍; 李丽丽

    2012-01-01

    Plant functional types (PFTs) are important in understanding the dynamics and the functions of an ecosystems, which provide also useful information for ecosystem management. In 28 observation plots of a naturally recovered popiar-birch woodland on the north slope of Qilian Mountains, China, 81 plant species were classified into 18 plant functional types (PFTs), according to their life forms (including arbors, lianas, subshrub, shrub, perennial grasses, perennial forbs and annual or biennial grass) and ecotypes (including xerophyte, xerophytic and mesophytic, mesophyte and hygrophyte). The relationships between PFTs and environmental factors were studied using Canonical Correspondence Analysis (CCA). The results showed that the dominant PFTs were PFTsl6 (mesophytic perennial forbs), PFTs23 (hygrophytic perennial forbs), PFTs9 (xerophytic and mesophytic perennial forbs) and PFTslS (mesophytic shrub) on the poplar-birch restoration woodland. The stratificd structure with wood, shrub and herb layers indicated the plant life forms had a tendency of complication and structurization, and the emerging mesophyte plants reflected changes of the micro-environments. The distribution patterns of PFTs were controlled by the soil physical and chemical properties in that soil bulk density, soil organic carbon and content of nitrogen determined the characteristics of the plant life forms, while the soil water moisture and canopy cover were the main ecologis factors that affected the distribution of ecotypes. The slope position and slope aspect controlled the plant distribution pattem and formation of the community.%依据生活型(乔木、藤本、灌木、半灌木、多年生禾草、多年生杂类草和一二年生草本)和水分生态型(旱生、旱中生、中生和湿生)将祁连山北坡次生杨桦林28个调查样地中的81个物种划分为18种植物功能型(Plant function types,PFTs),并通过典范对应分析(CCA)方法研究植物功能型与环境因子间

  4. Biospheric and petrogenic organic carbon flux along southeast Alaska

    Science.gov (United States)

    Cui, Xingqian; Bianchi, Thomas S.; Jaeger, John M.; Smith, Richard W.

    2016-10-01

    Holocene fjords store ca. 11-12% of the total organic carbon (OC) buried in marine sediments with fjords along southeast (SE) Alaska possibly storing half of this OC (Smith et al., 2015). However, the respective burial of biospheric (OCbio) and petrogenic OC (OCpetro) remains poorly constrained, particularly across glaciated versus non-glaciated systems. Here, we use surface sediment samples to quantify the sources and burial of sedimentary OC along SE Alaska fjord-coastal systems, and conduct a latitudinal comparison across a suite of fjords and river-coastal systems with distinctive OC sources. Our results for SE Alaska show that surface sediments in northern fjords (north of Icy Strait) with headwater glaciers are dominated by OCpetro, in contrast to marine and terrestrially-derived fresh OC in non-glaciated southern fjords. Along the continental shelf of the Gulf of Alaska, terrestrial OC is exported from rivers. Using end-member mixing models, we determine that glaciated fjords have significantly higher burial rates of OCpetro (∼ 1.1 ×103 gOC m-2yr-1) than non-glaciated fjords and other coastal systems, making SE Alaska potentially the largest sink of OCpetro in North America. In contrast, non-glaciated fjords in SE Alaska are effective in burying marine OC (OCbio-mari) (13-82 g OC m-2yr-1). Globally, OC in fjord sediments are comprised of a mixture of OCpetro and fresh OCbio, in contrast to the pre-aged OC from floodplain river-coastal systems. We find that there may be a general latitudinal trend in the role of fjords in processing OC, where high-latitude temperate glacial fjords (e.g., Yakutat Bay, SE Alaska) rebury OCpetro and non-glacial mid-latitude fjords (e.g., Doubtful Sound, Fiordland) sequester CO2 from phytoplankton and/or temperate forests. Overall, we propose that fjords are effective in sequestering OCbio and re-burying OCpetro. Based on our study, we hypothesize that climate change will have a semi-predictable impact on fjords' OC cycling in

  5. Mitochondrial DNA phylogeography of least cisco Coregonus sardinella in Alaska.

    Science.gov (United States)

    Padula, V M; Causey, D; López, J A

    2017-03-01

    This study presents the first detailed analysis of the mitochondrial DNA diversity of least cisco Coregonus sardinella in Alaska using a 678 bp segment of the control region (D-loop) of the mitochondrial genome. Findings suggest that the history of C. sardinella in Alaska differs from that of other species of Coregonus present in the state and surrounding regions. The examined populations of C. sardinella are genetically diverse across Alaska. Sixty-eight distinct mitochondrial haplotypes were identified among 305 individuals sampled from nine locations. The haplotype minimum spanning network and phylogeny showed a modest level of geographic segregation among haplotypes, suggesting high levels of on-going or recent connectivity among distant populations. Observed ΦST values and the results of homogeneity and AMOVAs indicate incipient genetic differentiation between aggregations in three broad regional groups. Sites north of the Brooks Range formed one group, sites in the Yukon and Selawik Rivers formed a second group and sites south of the Yukon drainage formed the third group. Overall, the sequence data showed that a large proportion of mtDNA genetic variation in C. sardinella is shared across Alaska, but this variation is not homogeneously distributed across all regions and for all haplotype groups.

  6. Population structure and genetic diversity of moose in Alaska.

    Science.gov (United States)

    Schmidt, Jennifer I; Hundertmark, Kris J; Bowyer, R Terry; McCracken, Kevin G

    2009-01-01

    Moose (Alces alces) are highly mobile mammals that occur across arboreal regions of North America, Europe, and Asia. Alaskan moose (Alces alces gigas) range across much of Alaska and are primary herbivore consumers, exerting a prominent influence on ecosystem structure and functioning. Increased knowledge gained from population genetics provides insights into their population dynamics, history, and dispersal of these unique large herbivores and can aid in conservation efforts. We examined the genetic diversity and population structure of moose (n = 141) with 8 polymorphic microsatellites from 6 regions spanning much of Alaska. Expected heterozygosity was moderate (H(E) = 0.483-0.612), and private alleles ranged from 0 to 6. Both F(ST) and R(ST) indicated significant population structure (P moose from the Yakutat and Tetlin regions versus all other moose, with slight substructure observed among the second population. Estimates of dispersal differed between analytical approaches, indicating a high level of historical or current gene flow. Mantel tests indicated that isolation-by-distance partially explained observed structure among moose populations (R(2) = 0.45, P moose in Alaska with population expansion from interior Alaska westward toward the coast.

  7. Eelgrass (Zostera marina) Microsatellite DNA Data; Pacific Coast of North America, 2000-2009

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set contains genetic information collected from eelgrass (Zostera marina) populations along the Pacific coast of North America from Alaska to Baha...

  8. Evidence for Freshwater Discharge at a Gas Hydrate-Bearing Seafloor Mound on the Beaufort Sea Continental Slope

    Science.gov (United States)

    Pohlman, J.; Lorenson, T. D.; Hart, P. E.; Ruppel, C. D.; Joseph, C.; Torres, M. E.; Edwards, B. D.

    2011-12-01

    A deep-water (~2.5 km water depth) seafloor mound located ~150 km offshore of the North Slope Alaska, informally named the Canning Seafloor Mound (CSM), contains a documented occurrence of gas hydrate; the first from the Beaufort Sea. Gases and porewater extracted from cores taken at the CSM summit several months after core recovery provided surprisingly consistent and outstanding results. Gases migrating into the structure are likely a mixture of primary microbial gas formed by carbonate reduction and secondary microbial gas formed from degraded thermogenic gases, linking the system to deep oil and gas generation (see companion abstract by Lorenson et al.). Pore fluids extracted from the base of the 572 cm-long hydrate-bearing core had chloride values as low as 160 mM, which equates to an ~80% freshwater contribution. Low chloride values, often interpreted as a product of gas hydrate dissociation in hydrate-bearing cores, were coincident with sulfate values in excess of 1 mM and as high as 22 mM (seawater is ~28mM). High sulfate concentrations generally indicate an absence of methane, and, thus, gas hydrate; therefore, an allochthonous source of freshwater is required. Potential sources are clay mineral dehydration, clay membrane filtration and/or a meteoric water influx. Several lines of evidence indicate the Canning Seafloor Mound is connected to either a deep, landward freshwater aquifer or to an unusually fresh oil field brine. First, Na/Cl ratios decrease from marine (~0.86) near the seafloor to distinctly higher values of 1.20 at the bottom of the core. Second, clay dehydration and ion filtration processes have not, to our knowledge, yielded fluids as fresh as measured in these near-seafloor sediments. Third, and most importantly, δ18O-δD systematics of fluid end members are entirely consistent with a meteoric water source and inconsistent with trends expected for either gas hydrate dissociation, smectite to illite clay dewatering or ion filtration

  9. New Views of the Gulf of Alaska Margin Mapped for UNCLOS Applications

    Science.gov (United States)

    Mayer, L. A.; Gardner, J. V.; Armstrong, A.; Calder, B. R.; Malik, M.; Angwenyi, C.; Karlpata, S.; Montoro-Dantes, H.; Morishita, T.; Mustapha, A.; van Waes, M.; Wood, D.; Withers, A.

    2005-12-01

    Article 76 of the UN Convention on the Law of the Sea (UNCLOS) outlines a series of criteria that may allow a coastal state to extend its legal jurisdiction beyond the EEZ. The mapping required to support an UNCLOS submission generates datasets useful to a wide spectrum of disciplines; the new maps will provide a new framework for the next generation of continental-margin studies. As part of an ongoing U.S. UNCLOS effort, >162,000 km2 of the Gulf of Alaska (GOA) margin between the 1 and 4.5 km isobaths was mapped in 2005 with a 12-kHz multibeam echosounder (MBES) that provides bathymetry and co-registered backscatter. The data have a spatial resolution of 100 m. The north and east GOA shelf is truncated by the strike-slip Queen Charlotte-Fairweather and Transition Faults. The margin is draped by overlapping submarine-fans e modified by incised channel-levee systems. The Baranof Fan is composed of several fans. The southern-most mapped fan is a small feature from which springs the upper reaches of Mukluk Channel. Horizon channel-levee complex traverses SW across the margin. The two channels meet ~80 km down slope at a 90? junction where Mukluk Channel is captured by Horizon Channel. Chatham Fan covers more than 3000 km2 and is incised by an unnamed meandering channel and built by an associated levee complex. The levee is incised by a meandering channel-levee complex. The sediments of this fan have high backscatter. Vast zones of rotational sliding occupy the northern flanks of the levees. The slides typically are retrogressive and shear-dominated with limited down slope movement. The next fan complex to the north, Kruzofi fan, buries more than 7500 km2 of the margin. This fan developed between the levee of Chatham fan and a curving depositional ridge. Gravity data implies that this ridge may be structurally controlled. The growth of Kruzofi fan to the east appears to have been so rapid that the channels have been deflected to the NW so that they trend sub

  10. Southwest Alaska Regional Geothermal Energy Project

    Energy Technology Data Exchange (ETDEWEB)

    Holdmann, Gwen [Univ. of Alaska, Fairbanks, AK (United States)

    2015-04-30

    The village of Elim, Alaska is 96 miles west of Nome, on the Seward Peninsula. The Darby Mountains north of the village are rich with hydrothermal systems associated with the Darby granitic pluton(s). In addition to the hot springs that have been recorded and studied over the last 100 years, additional hot springs exist. They are known through a rich oral history of the region, though they are not labeled on geothermal maps. This research primarily focused on Kwiniuk Hot Springs, Clear Creek Hot Springs and Molly’s Hot Springs. The highest recorded surface temperatures of these resources exist at Clear Creek Hot Springs (67°C). Repeated water sampling of the resources shows that maximum temperatures at all of the systems are below boiling.

  11. Alaska Arctic marine fish ecology catalog

    Science.gov (United States)

    Thorsteinson, Lyman K.; Love, Milton S.

    2016-08-08

    The marine fishes in waters of the United States north of the Bering Strait have received new and increased scientific attention over the past decade (2005–15) in conjunction with frontier qualities of the region and societal concerns about the effects of Arctic climate change. Commercial fisheries are negligible in the Chukchi and Beaufort Seas, but many marine species have important traditional and cultural values to Alaska Native residents. Although baseline conditions are rapidly changing, effective decisions about research and monitoring investments must be based on reliable information and plausible future scenarios. For the first time, this synthesis presents a comprehensive evaluation of the marine fish fauna from both seas in a single reference. Although many unknowns and uncertainties remain in the scientific understanding, information presented here is foundational with respect to understanding marine ecosystems and addressing dual missions of the U.S. Department of the Interior for energy development and resource conservation. 

  12. Improving Sanitation and Health in Rural Alaska

    Science.gov (United States)

    Bubenheim, David L.

    2013-01-01

    In rural Alaskan communities personal health is threatened by energy costs and limited access to clean water, wastewater management, and adequate nutrition. Fuel-­-based energy systems are significant factors in determining local accessibility to clean water, sanitation and food. Increasing fuel costs induce a scarcity of access and impact residents' health. The University of Alaska Fairbanks (UAF) School of Natural Resources and Agricultural Sciences (SNRAS), NASA's Ames Research Center, and USDA Agricultural Research Service (ARS) have joined forces to develop high-efficiency, low­-energy consuming techniques for water treatment and food production in rural circumpolar communities. Methods intended for exploration of space and establishment of settlements on the Moon or Mars will ultimately benefit Earth's communities in the circumpolar north. The initial phase of collaboration is completed. Researchers from NASA Ames Research Center and SNRAS, funded by the USDA­-ARS, tested a simple, reliable, low-energy sewage treatment system to recycle wastewater for use in food production and other reuse options in communities. The system extracted up to 70% of the water from sewage and rejected up to 92% of ions in the sewage with no carryover of toxic effects. Biological testing showed that plant growth using recovered water in the nutrient solution was equivalent to that using high-purity distilled water. With successful demonstration that the low energy consuming wastewater treatment system can provide safe water for communities and food production, the team is ready to move forward to a full-scale production testbed. The SNRAS/NASA team (including Alaska students) will design a prototype to match water processing rates and food production to meet rural community sanitation needs and nutritional preferences. This system would be operated in Fairbanks at the University of Alaska through SNRAS. Long­-term performance will be validated and operational needs of the

  13. ALASKA1964_OBS - Alaska 1964 Tsunami Observations at Seaside, Oregon

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set is a point shapefile representing observations of inundation and water levels from the Alaska 1964 event obtained by Tom Horning (1997). The geospatial...

  14. 2005 Alaska Division of Geological & Geophysical Surveys Lidar: Unalakleet, Alaska

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This report is a summary of a LiDAR data collection over the community of Unalakleet, in the Norton Sound region of Alaska. The original data were collected on...

  15. The Influence of fold and fracture development on reservoir behavior of the Lisburne Group of northern Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Wesley K. Wallace; Catherine L. Hanks; Jerry Jensen: Michael T. Whalen; Paul Atkinson; Joseph Brinton; Thang Bui; Margarete Jadamec; Alexandre Karpov; John Lorenz; Michelle M. McGee; T.M. Parris; Ryan Shackleton

    2004-07-01

    The Carboniferous Lisburne Group is a major carbonate reservoir unit in northern Alaska. The Lisburne is folded and thrust faulted where it is exposed throughout the Brooks Range, but is relatively undeformed in areas of current production in the subsurface of the North Slope. The objectives of this study were to develop a better understanding of four major aspects of the Lisburne: (1) The geometry and kinematics of folds and their truncation by thrust faults. (2) The influence of folding on fracture patterns. (3) The influence of deformation on fluid flow. (4) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics. Symmetrical detachment folds characterize the Lisburne in the northeastern Brooks Range. In contrast, Lisburne in the main axis of the Brooks Range is deformed into imbricate thrust sheets with asymmetrical hangingwall anticlines and footwall synclines. The Continental Divide thrust front separates these different structural styles in the Lisburne and also marks the southern boundary of the northeastern Brooks Range. Field studies were conducted for this project during 1999 to 2001 in various locations in the northeastern Brooks Range and in the vicinity of Porcupine Lake, immediately south of the Continental Divide thrust front. Results are summarized below for the four main subject areas of the study.

  16. A possible transoceanic tsunami directed toward the U.S. west coast from the Semidi segment, Alaska convergent margin

    Science.gov (United States)

    von Huene, Roland; Miller, John J.; Dartnell, Peter

    2016-01-01

    The Semidi segment of the Alaska convergent margin appears capable of generating a giant tsunami like the one produced along the nearby Unimak segment in 1946. Reprocessed legacy seismic reflection data and a compilation of multibeam bathymetric surveys reveal structures that could generate such a tsunami. A 200 km long ridge or escarpment with crests >1 km high is the surface expression of an active out-of-sequence fault zone, recently referred to as a splay fault. Such faults are potentially tsunamigenic. This type of fault zone separates the relatively rigid rock of the margin framework from the anelastic accreted sediment prism. Seafloor relief of the ridge exceeds that of similar age accretionary prism ridges indicating preferential slip along the splay fault zone. The greater slip may derive from Quaternary subduction of the Patton Murray hot spot ridge that extends 200 km toward the east across the north Pacific. Estimates of tsunami repeat times from paleotsunami studies indicate that the Semidi segment could be near the end of its current inter-seismic cycle. GPS records from Chirikof Island at the shelf edge indicate 90% locking of plate interface faults. An earthquake in the shallow Semidi subduction zone could generate a tsunami that will inundate the US west coast more than the 1946 and 1964 earthquakes because the Semidi continental slope azimuth directs a tsunami southeastward.

  17. Results and synthesis of integrated geologic studies of the carboniferous Lisburne Group of Northeastern Alaska. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Watts, K.F.

    1995-05-01

    The primary objective of this project was to develop an integrated database to characterize reservoir heterogeneities resulting from numerous small-scale shallowing-upward cycles (parasequences) comprising the Pennsylvanian Wahoo 1imestone. The Wahoo Limestone is the upper part of an extensive carbonate platform sequence of the Carboniferous Lisburne Group which is widely exposed in the Brooks Range and is a widespread hydrocarbon reservoir unit in the subsurface of the North Slope of Alaska. A leading goal is to determine lateral and vertical variations in the complex mosaic of carbonate facies comprising the Wahoo. Aspects of rock units adjacent to the Wahoo, the underlying Endicott Group and Alapah Limestone and overlying Echooka Formation are also discussed. This report includes an overview of the regional geological framework; a discussion of biostratigraphic results; a summary of diagenetic studies; and preliminary results of comparative studies of a cored well in the Lisburne oil field. A computerized database system (the Wahoo database) was developed and is explained in a users manual. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  18. A possible transoceanic tsunami directed toward the U.S. west coast from the Semidi segment, Alaska convergent margin

    Science.gov (United States)

    von Huene, Roland; Miller, John J.; Dartnell, Peter

    2016-03-01

    The Semidi segment of the Alaska convergent margin appears capable of generating a giant tsunami like the one produced along the nearby Unimak segment in 1946. Reprocessed legacy seismic reflection data and a compilation of multibeam bathymetric surveys reveal structures that could generate such a tsunami. A 200 km long ridge or escarpment with crests >1 km high is the surface expression of an active out-of-sequence fault zone, recently referred to as a splay fault. Such faults are potentially tsunamigenic. This type of fault zone separates the relatively rigid rock of the margin framework from the anelastic accreted sediment prism. Seafloor relief of the ridge exceeds that of similar age accretionary prism ridges indicating preferential slip along the splay fault zone. The greater slip may derive from Quaternary subduction of the Patton Murray hot spot ridge that extends 200 km toward the east across the north Pacific. Estimates of tsunami repeat times from paleotsunami studies indicate that the Semidi segment could be near the end of its current inter-seismic cycle. GPS records from Chirikof Island at the shelf edge indicate 90% locking of plate interface faults. An earthquake in the shallow Semidi subduction zone could generate a tsunami that will inundate the US west coast more than the 1946 and 1964 earthquakes because the Semidi continental slope azimuth directs a tsunami southeastward.

  19. 75 FR 38758 - Pacific Halibut Fisheries; Limited Access for Guided Sport Charter Vessels in Alaska

    Science.gov (United States)

    2010-07-06

    ... for Guided Sport Charter Vessels in Alaska AGENCY: National Marine Fisheries Service (NMFS), National... guided sport fishery for Pacific halibut in the waters of International Pacific Halibut Commission... the halibut fishery management goals of the North Pacific Fishery Management Council. DATES:...

  20. THE EQUIVALENT SLOPE - A NEW METHOD FOR CALCULATING SOIL LOSS FROM IRREGULAR SLOPES

    Institute of Scientific and Technical Information of China (English)

    Xiaoguang ZHAO; Hui SHI; Ming'an SHAO

    2004-01-01

    The slopes in field conditions are always irregular, but the supposed uniform slopes are used in most erosion models. Some studies used several uniform slopes to approximate an irregular slope for estimating soil erosion. This approximation is both time-consuming and weak in physical insights. In this paper, the concept of equivalent slope is presented based on that runoff potential on uniform slope is equal to that of irregular slope, and the equivalent uniform slope is used to estimate soil erosion instead of the irregular slopes. The estimated results of slope-length factors for convex and concave slopes are consistent with those from the method of Foster and Wischmeier.The experiments in the southern part of the Loess Plateau in China confirmed the applicability of the present method. The method is simple and has, to some extent, clear physical meanings, and is applicable for estimating soil erosion from irregular slopes.

  1. Paleoseismic study of the Cathedral Rapids fault in the northern Alaska Range near Tok, Alaska

    Science.gov (United States)

    Koehler, R. D.; Farrell, R.; Carver, G. A.

    2010-12-01

    The Cathedral Rapids fault extends ~40 km between the Tok and Robertson River valleys and is the easternmost fault in a series of active south-dipping imbricate thrust faults which bound the northern flank of the Alaska Range. Collectively, these faults accommodate a component of convergence transferred north of the Denali fault and related to the westward (counterclockwise) rotation of the Wrangell Block driven by relative Pacific/North American plate motion along the eastern Aleutian subduction zone and Fairweather fault system. To the west, the system has been defined as the Northern Foothills Fold and Thrust Belt (NFFTB), a 50-km-wide zone of east-west trending thrust faults that displace Quaternary deposits and have accommodated ~3 mm/yr of shortening since latest Pliocene time (Bemis, 2004). Over the last several years, the eastward extension of the NFFTB between Delta Junction and the Canadian border has been studied by the Alaska Division of Geological & Geophysical Surveys to better characterize faults that may affect engineering design of the proposed Alaska-Canada natural gas pipeline and other infrastructure. We summarize herein reconnaissance field observations along the western part of the Cathedral Rapids fault. The western part of the Cathedral Rapids fault extends 21 km from Sheep Creek to Moon Lake and is characterized by three roughly parallel sinuous traces that offset glacial deposits of the Illinoian to early Wisconsinan Delta glaciations and the late Wisconsinan Donnelly glaciation, as well as, Holocene alluvial deposits. The northern trace of the fault is characterized by an oversteepened, beveled, ~2.5-m-high scarp that obliquely cuts a Holocene alluvial fan and projects into the rangefront. Previous paleoseismic studies along the eastern part of the Cathedral Rapids fault and Dot “T” Johnson fault indicate multiple latest Pleistocene and Holocene earthquakes associated with anticlinal folding and thrust faulting (Carver et al., 2010

  2. Level III Ecoregions of Alaska

    Data.gov (United States)

    U.S. Environmental Protection Agency — Ecoregions denote areas of general similarity in ecosystems and in the type, quality, and quantity of environmental resources. The ecoregions of Alaska are a...

  3. Predator control problems in Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One of the important wildlife management activities in Alaska is that of predator control. This simple statement requires some explanation. In the course of these...

  4. Alaska waterfowl production survey, 1968

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Production and Habitat Survey for Alaska during 1968. The primary purpose of the survey is to provide information on duck...

  5. Interior Alaska Bouguer Gravity Anomaly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A 1 kilometer Complete Bouguer Anomaly gravity grid of interior Alaska. Only those grid cells within 10 kilometers of a gravity data point have gravity values....

  6. Alaska Geoid Heights (GEOID96)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' x 4' geoid height grid for Alaska is distributed as a GEOID96 model. The computation used 1.1 million terrestrial and marine gravity data held in the...

  7. Kevadel Alaska talves / Tiiu Ehrenpreis

    Index Scriptorium Estoniae

    Ehrenpreis, Tiiu

    2007-01-01

    Autori muljeid 22.-25. märtsini Fairbanksis toimunud Alaska Ülikooli ja Ülemaailmse Arktika Uurimise Keskuse (IARC) juhtimisel GLOBE'i programmi uue projekti "Aastaajad ja bioomid" koolitusseminarist

  8. Alaska duck production surveys: 1990

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the duck production survey for Alaska during 1990. The primary purpose of the survey is to provide information on duck production from the...

  9. Recurring Slope Lineae and Future Exploration of Mars

    Science.gov (United States)

    McEwen, Alfred; Byrne, Shane; Chevrier, Vincent; Chojnacki, Matt; Dundas, Colin; Masse, Marion; Mattson, Sarah; Ojha, Lujendra; Pommerol, Antoine; Toigo, Anthony; Wray, James

    2014-05-01

    Recurring slope lineae (RSL) on Mars may be evidence for the seasonal flow or seepage of water on relatively warm slopes. RSL are narrow (250 K to >300 K. Over the past Martian year we have monitored active RSL in equatorial (0°-15°S) regions of Mars, especially in the deep canyons of Valles Marineris [McEwen et al., 2014, Nature Geoscience]. These equatorial RSL are especially active on north-facing slopes in northern summer and spring and on south-facing slopes in southern spring and summer, following the most normal solar incidence angles on these steep slopes. More recently we have confirmed RSL near 35°N in the low-albedo and low-altitude Acidalia Planitia. All RSL locations have warm peak daily temperatures (typically >273 K at the surface) in the seasons when RSL are active, and occur on steep, rocky, low-albedo slopes. However, most times and places with these properties lack apparent RSL, so there are additional, unseen requirements. We do not know what time of day RSL are actively flowing. Seasonal variation in the atmospheric column abundance of water vapor does not match the RSL activity. Seasonal melting of shallow ice best explains the RSL observations, but the origin and replenishment of such ice is not understood, especially in the tropics. Laboratory experiments are consistent with two key MRO observations: (1) that seeping water darkens basaltic soils but may only produce weak water absorption bands undetectable in ratio spectra after partial dehydration during the low-humidity middle afternoon conditions when MRO observes; and (2) the flows are more linear than under terrestrial conditions and do not erode channels under Martian atmospheric pressures [Masse et al., 2014, LPSC]. No dry process is known to create such slowly creeping seasonal flows. The potential for equatorial water activity creates new exploration opportunities, to search for extant life, as well as challenges such as the definition of special regions for planetary protection.

  10. An Alaska Soil Carbon Database

    Science.gov (United States)

    Johnson, Kristofer; Harden, Jennifer

    2009-05-01

    Database Collaborator's Meeting; Fairbanks, Alaska, 4 March 2009; Soil carbon pools in northern high-latitude regions and their response to climate changes are highly uncertain, and collaboration is required from field scientists and modelers to establish baseline data for carbon cycle studies. The Global Change Program at the U.S. Geological Survey has funded a 2-year effort to establish a soil carbon network and database for Alaska based on collaborations from numerous institutions. To initiate a community effort, a workshop for the development of an Alaska soil carbon database was held at the University of Alaska Fairbanks. The database will be a resource for spatial and biogeochemical models of Alaska ecosystems and will serve as a prototype for a nationwide community project: the National Soil Carbon Network (http://www.soilcarb.net). Studies will benefit from the combination of multiple academic and government data sets. This collaborative effort is expected to identify data gaps and uncertainties more comprehensively. Future applications of information contained in the database will identify specific vulnerabilities of soil carbon in Alaska to climate change, disturbance, and vegetation change.

  11. VT Lidar Slope (1 meter) - 2005 - Essex

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) This metadata applies to the following collection area(s): Essex County 2005 1m and related SLOPE datasets. Created using ArcGIS "SLOPE" command...

  12. Gravity-induced stresses in finite slopes

    Science.gov (United States)

    Savage, W.Z.

    1994-01-01

    An exact solution for gravity-induced stresses in finite elastic slopes is presented. This solution, which is applied for gravity-induced stresses in 15, 30, 45 and 90?? finite slopes, has application in pit-slope design, compares favorably with published finite element results for this problem and satisfies the conditions that shear and normal stresses vanish on the ground surface. The solution predicts that horizontal stresses are compressive along the top of the slopes (zero in the case of the 90?? slope) and tensile away from the bottom of the slopes, effects which are caused by downward movement and near-surface horizontal extension in front of the slope in response to gravity loading caused by the additional material associated with the finite slope. ?? 1994.

  13. Effect of Fertilizer Application Rates on Cassava N, P, K Accumulations and Allocation and Yield in Sloping Lands of North Guangdong%不同施肥水平对木薯氮磷钾养分积累、分配及其产量的影响

    Institute of Scientific and Technical Information of China (English)

    高志红; 陈晓远; 林昌华; 张宇鹏; 何永胜

    2011-01-01

    [目的]通过比较不同施肥水平下木薯氮磷钾养分积累、分配和产量的差异,探讨粤北坡岗地优质高产木薯氮磷钾养分的最佳用量.[方法]以木薯品种南美119为材料,采用"3414"方案,在粤北翁源进行大田试验.试验共设14个处理.[结果]施肥处理的氮素主要分配到地上部,不施肥处理的氮素则主要分配到根部;不同施肥处理的磷素均主要分配到地上部;不施肥处理和不施钾处理的钾素主要分配到根部,不施氮处理的钾素在根、冠间分配较均衡.在木薯不同生长阶段,植株氮磷钾含量均呈下降趋势,但施氮、磷、钾化学肥料处理植株氮磷钾含量的下降速度小于不施氮、磷、钾化学肥料的处理.处理NPK的氮、磷、钾含量和积累量在各生育期均为最大,不施肥处理(NPK)的氮、磷、钾含量和积累量在各生育期均为最小(PPK处理,为22 694.06 kg·hm,其次是NPK处理,为21 417.87 kg·hm.[结论]木薯产量、氮磷钾养分积累及其在根冠间的分配,对施肥水平高度敏感,适当比例的氮磷钾肥配合施用既可以显著增加木薯植株的氮磷钾含量和积累量,又可以提高产量.在粤北坡岗地木薯生产中,氮素最重要,在氮素得到满足的条件下,磷素较钾素更重要.在本试验条件下,氮磷钾养分最佳用量为358.80 kgN·hm、89.10 kg PO·hm和187.50 kg KO·hm.%[Objective] The present study was carried out to analyze the differences in cassava (Manihot esculenta Crantz) N,P, K accumulation, allocation and yields. The best N, P, K application rates were studied at sloping lands of Wengyuan of North Guangdong. [Method] Cassava genotype South America 119 was used as materials in a field experiment of "3414" conducted in Wengyuan of North Guangdong. The experiment have 14 treatments. [Result] Nitrogen in cassava with fertilizer treatment was mainly treatments allocated to the shoot, and nitrogen in cassava with out fertilizers

  14. Geologic map of Saint Lawrence Island, Alaska

    Science.gov (United States)

    Patton, William W.; Wilson, Frederic H.; Taylor, Theresa A.

    2011-01-01

    Saint Lawrence Island is located in the northern Bering Sea, 190 km southwest of the tip of the Seward Peninsula, Alaska, and 75 km southeast of the Chukotsk Peninsula, Russia (see index map, map sheet). It lies on a broad, shallow-water continental shelf that extends from western Alaska to northeastern Russia. The island is situated on a northwest-trending structural uplift exposing rocks as old as Paleozoic above sea level. The submerged shelf between the Seward Peninsula and Saint Lawrence Island is covered mainly with Cenozoic deposits (Dundo and Egiazarov, 1982). Northeast of the island, the shelf is underlain by a large structural depression, the Norton Basin, which contains as much as 6.5 km of Cenozoic strata (Grim and McManus, 1970; Fisher and others, 1982). Sparse test-well data indicate that the Cenozoic strata are underlain by Paleozoic and Proterozoic rocks, similar to those exposed on the Seward Peninsula (Turner and others, 1983). Saint Lawrence Island is 160 km long in an east-west direction and from 15 km to 55 km wide in a north-south direction. The east end of the island consists largely of a wave-cut platform, which has been elevated as much as 30 m above sea level. Isolated upland areas composed largely of granitic plutons rise as much as 550 m above the wave-cut platform. The central part of the island is dominated by the Kookooligit Mountains, a large Quaternary shield volcano that extends over an area of 850 km2 and rises to an elevation of 630 m. The west end of the island is composed of the Poovoot Range, a group of barren, rubble-covered hills as high as 450 m that extend from Boxer Bay on the southwest coast to Taphook Mountain on the north coast. The Poovoot Range is flanked on the southeast by the Putgut Plateau, a nearly flat, lake-dotted plain that stands 30?60 m above sea level. The west end of the island is marked by uplands underlain by the Sevuokuk pluton (unit Kg), a long narrow granite body that extends from Gambell on the

  15. ALASKA1964_RUNUP - Alaska 1964 Tsunami Runup Heights at Seaside, Oregon (alaska1964_runup.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set is a point shapefile representing tsunami inundation runup heights for the Alaska 1964 event based on observations and associated information obtained...

  16. Alaska Athabascan stellar astronomy

    Science.gov (United States)

    Cannon, Christopher M.

    2014-01-01

    Stellar astronomy is a fundamental component of Alaska Athabascan cultures that facilitates time-reckoning, navigation, weather forecasting, and cosmology. Evidence from the linguistic record suggests that a group of stars corresponding to the Big Dipper is the only widely attested constellation across the Northern Athabascan languages. However, instruction from expert Athabascan consultants shows that the correlation of these names with the Big Dipper is only partial. In Alaska Gwich'in, Ahtna, and Upper Tanana languages the Big Dipper is identified as one part of a much larger circumpolar humanoid constellation that spans more than 133 degrees across the sky. The Big Dipper is identified as a tail, while the other remaining asterisms within the humanoid constellation are named using other body part terms. The concept of a whole-sky humanoid constellation provides a single unifying system for mapping the night sky, and the reliance on body-part metaphors renders the system highly mnemonic. By recognizing one part of the constellation the stargazer is immediately able to identify the remaining parts based on an existing mental map of the human body. The circumpolar position of a whole-sky constellation yields a highly functional system that facilitates both navigation and time-reckoning in the subarctic. Northern Athabascan astronomy is not only much richer than previously described; it also provides evidence for a completely novel and previously undocumented way of conceptualizing the sky---one that is unique to the subarctic and uniquely adapted to northern cultures. The concept of a large humanoid constellation may be widespread across the entire subarctic and have great antiquity. In addition, the use of cognate body part terms describing asterisms within humanoid constellations is similarly found in Navajo, suggesting a common ancestor from which Northern and Southern Athabascan stellar naming strategies derived.

  17. On the climate and climate change of Sitka, Southeast Alaska

    Science.gov (United States)

    Wendler, Gerd; Galloway, Kevin; Stuefer, Martin

    2016-10-01

    observed warming is less pronounced than the values found for Interior and especially Arctic Alaska for later time period for which such a comparison was possible (Wendler et al. 2014). Significant correlation values were found with the Pacific Decadal Oscillation (PDO), the North Pacific (NP) Index, El Nino 3.4, and the 18.4 years nodal tide; the latter was previously reported in an excellent investigation by T. Royer (1993).

  18. In-Place Randomized Slope Selection

    DEFF Research Database (Denmark)

    Blunck, Henrik; Vahrenhold, Jan

    2006-01-01

    Slope selection, i.e. selecting the slope with rank k among all 􀀀n 2lines induced by a collection P of points, results in a widely used robust estimator for linefitting. In this paper, we demonstrate that it is possible to perform slope selection in expected O(n·log2 n) time using only...

  19. 天山北坡某集约化牛场生鲜乳质量安全分析%The Analysis of the Quality and Safety of Raw Milk in an Intensive Dairy Farm in North Slope of Tianshan Mountain

    Institute of Scientific and Technical Information of China (English)

    康立超; 卢春霞; 罗小玲

    2014-01-01

    To evaluate the quality and safety of raw milk of the north slope of Tianshan mountain, The raw milk somatic cell count, total bacteria, milk ingredients, harmful substances and antibiotics was analyzed by the national standard method, somatic cell detector and dairy ingredients analyzer, respectively. The results showed that the SCS was 780 600 cells/mL, the total number of bacteria was 232,000 CFU/mL. Milk fat ingredients were 4.48g/100g, non-fat milk solids were 7.69g/100g, a density was 1.026g/mL, protein content was 2.87g/100g, the freezing point was-0.48℃, impurity was 2.5mg/L, mineral content was 0.72g/100g. Hazardous substances and antibiotics were not detected. Conclusion was drawn that the raw milk has high somatic cells. The strict control of mastitis incidence was needed to improve the milk quality .%本文采用国标方法、体细胞检测仪和乳品成分分析仪检测分析了天山北坡某牛场生鲜乳体细胞数、细菌总数、乳成分、密度、冰点、杂质度及有害物质和抗生素等。结果体细胞数为78.06万/mL,细菌总数为23.20万CFU/mL,脂肪为4.48g/100g,非脂乳固体为7.69g/100g,蛋白质为2.87g/100g,矿物质为0.72g/100g,密度为1.026g/mL,冰点为-0.48℃,杂质度为2.5mg/L。有害物质和抗生素均未检出或远低于限量标准。可以得出:该集约化牛场生鲜乳体细胞数偏高,非脂乳固体和密度未达到国家标准要求。

  20. Satellite View of Alaska - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Satellite View of Alaska map layer is a 200-meter-resolution simulated-natural-color image of Alaska. Vegetation is generally green, with darker greens...

  1. Oceanographic profile data collected from CTD and sound velocimeter - moving vessel profiler casts aboard NOAA Ship FAIRWEATHER as part of project OPR-N324-FA-10 in the Coastal Waters of SE Alaska and North Pacific Ocean from 2010-06-02 to 2010-06-29 (NCEI Accession 0130657)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0130657 includes physical and profile data collected aboard NOAA Ship FAIRWEATHER during project OPR-N324-FA-10 in the Coastal Waters of SE Alaska and...

  2. Mycorrhizal aspects in slope stabilisation

    Science.gov (United States)

    Graf, Frank

    2016-04-01

    In order to re-colonise and stabilise slopes affected by superficial soil failure with plants essential requirements have to be met: the plants must grow the plants must survive sustainably plant succession must start and continuously develop These requirements, however, are anything but easy given, particularly under the often hostile environmental conditions dominating on bare and steep slopes. Mycorrhizal fungi, the symbiotic partners of almost all plants used in eco-engineering, are said to improve the plants' ability to overcome periods governed by strongly (growth) limiting factors. Subsequently, results of investigations are presented of mycorrhizal effects on different plant and soil functions related to eco-engineering in general and soil and slope stabilisation in particular. Generally, inoculation yielded higher biomass of the host plants above as well as below ground. Furthermore, the survival rate was higher for mycorrhized compared to non-mycorrhized plants, particularly under extreme environmental conditions. However, the scale of the mycorrhizal impact may be species specific of both the plant host as well as the fungal partner(s) and often becomes evident only after a certain time lag. Depending on the plant-fungus combination the root length per soil volume was found to be between 0 and 2.5 times higher for inoculated compared to non-inoculated specimens. On an alpine graded ski slope the survival of inoculated compared to non-treated Salix herbacea cuttings was significant after one vegetation period only for one of the three added mycorrhizal fungus species. However, after three years all of the inoculated plantlets performed significantly better than the non-inoculated controls. The analysis of the potential for producing and stabilising soil aggregates of five different ectomycorrhizal fungi showed high variation and, for the species Inocybe lacera, no significant difference compared to untreated soil. Furthermore, inoculation of Salix

  3. Modeled Climate and Disturbance Impacts to Carbon Sequestration of Recent Interior Boreal Alaska Ecosystem Productivity Declines

    Science.gov (United States)

    Neigh, C. S.; Carvalhais, N.; Collatz, G. J.; Tucker, C. J.

    2010-12-01

    Terrestrial Higher Northern Latitude Boreal ecosystems over the past half century have and are expected to incur substantial future climate warming altering long-term biophysical processes that mediate carbon sink status. Boreal ecosystems are one of the primary terrestrial pools with high organic and mineral soil carbon concentrations due to reduced decomposition from extended periods below freezing. Direct impacts of changing local to regional climate have altered Interior Alaska disturbance regimes shifting patterns of net primary production (NPP), soil heterotrophic respiration (Rh), net ecosystem production (NEP = NPP - Rh) and net biome production (NBP = NEP - De) which includes disturbance events (De). We investigated ecosystem dynamics with a satellite remote sensing driven model accounting for fine-scale heterogeneous events observed from multi temporal-spectral index vectors derived from Landsat. Our intent was to elucidate local to regional processes which have resulted in negative trends observed from the NOAA series of Advanced Very High Resolution Radiometers (AVHRR) over the past decade. The Carnegie-Ames-Stanford approach (CASA) model was run with changing fractional burned area to simulate bi-monthly patterns of net plant carbon fixation, biomass and nutrient allocation, litterfall, soil nitrogen mineralization, combustion emissions, and microbial CO2 production. Carbon reallocation was based on fire disturbances identified with remote sensing data (Landsat, IKONOS, and aerial photography) and disturbance perimeter maps from land management agencies. Warming coupled with insect and fire disturbance emissions reduced interior Boreal forest recalcitrant carbon pools for which losses greatly exceed the North Slope Tundra sink. Our multi spatial-temporal approach confirms substantial forested NPP declines in Landsat and AVHRR while distinguishing abiotic and biophysical disturbance frequency impacts upon NBP.

  4. The Influence of Shales on Slope Instability

    Science.gov (United States)

    Stead, Doug

    2016-02-01

    Shales play a major role in the stability of slopes, both natural and engineered. This paper attempts to provide a review of the state-of-the-art in shale slope stability. The complexities of shale terminology and classification are first reviewed followed by a brief discussion of the important physical and mechanical properties of relevance to shale slope stability. The varied mechanisms of shale slope stability are outlined and their importance highlighted by reference to international shale slope failures. Stability analysis and modelling of anisotropic rock slope masses are briefly discussed and the potential role of brittle rock fracture and damage highlighted. A short review of shale slopes in open pits is presented.

  5. Nuclear and mitochondrial markers reveal evidence for genetically segregated cryptic speciation in giant Pacific octopuses from Prince William Sound, Alaska

    Science.gov (United States)

    Toussaint, Rebecca K.; Scheel, David; Sage, G.K.; Talbot, S.L.

    2012-01-01

    Multiple species of large octopus are known from the north Pacific waters around Japan, however only one large species is known in the Gulf of Alaska (the giant Pacific octopus, Enteroctopus dofleini). Current taxonomy of E. dofleini is based on geographic and morphological characteristics, although with advances in genetic technology that is changing. Here, we used two mitochondrial genes (cytochrome b and cytochrome oxidase I), three nuclear genes (rhodopsin, octopine dehydrogenase, and paired-box 6), and 18 microsatellite loci for phylogeographic and phylogenetic analyses of octopuses collected from across southcentral and the eastern Aleutian Islands (Dutch Harbor), Alaska. Our results suggest the presence of a cryptic Enteroctopus species that is allied to, but distinguished from E. dofleini in Prince William Sound, Alaska. Existence of an undescribed and previously unrecognized taxon raises important questions about the taxonomy of octopus in southcentral Alaska waters.

  6. Tularemia in Alaska, 1938 - 2010

    Directory of Open Access Journals (Sweden)

    Hansen Cristina M

    2011-11-01

    Full Text Available Abstract Tularemia is a serious, potentially life threatening zoonotic disease. The causative agent, Francisella tularensis, is ubiquitous in the Northern hemisphere, including Alaska, where it was first isolated from a rabbit tick (Haemophysalis leporis-palustris in 1938. Since then, F. tularensis has been isolated from wildlife and humans throughout the state. Serologic surveys have found measurable antibodies with prevalence ranging from F. tularensis isolates from Alaska were analyzed using canonical SNPs and a multi-locus variable-number tandem repeats (VNTR analysis (MLVA system. The results show that both F. t. tularensis and F. t. holarctica are present in Alaska and that subtype A.I, the most virulent type, is responsible for most recently reported human clinical cases in the state.

  7. Alaska volcanoes guidebook for teachers

    Science.gov (United States)

    Adleman, Jennifer N.

    2011-01-01

    Alaska’s volcanoes, like its abundant glaciers, charismatic wildlife, and wild expanses inspire and ignite scientific curiosity and generate an ever-growing source of questions for students in Alaska and throughout the world. Alaska is home to more than 140 volcanoes, which have been active over the last 2 million years. About 90 of these volcanoes have been active within the last 10,000 years and more than 50 of these have been active since about 1700. The volcanoes in Alaska make up well over three-quarters of volcanoes in the United States that have erupted in the last 200 years. In fact, Alaska’s volcanoes erupt so frequently that it is almost guaranteed that an Alaskan will experience a volcanic eruption in his or her lifetime, and it is likely they will experience more than one. It is hard to imagine a better place for students to explore active volcanism and to understand volcanic hazards, phenomena, and global impacts. Previously developed teachers’ guidebooks with an emphasis on the volcanoes in Hawaii Volcanoes National Park (Mattox, 1994) and Mount Rainier National Park in the Cascade Range (Driedger and others, 2005) provide place-based resources and activities for use in other volcanic regions in the United States. Along the lines of this tradition, this guidebook serves to provide locally relevant and useful resources and activities for the exploration of numerous and truly unique volcanic landscapes in Alaska. This guidebook provides supplemental teaching materials to be used by Alaskan students who will be inspired to become educated and prepared for inevitable future volcanic activity in Alaska. The lessons and activities in this guidebook are meant to supplement and enhance existing science content already being taught in grade levels 6–12. Correlations with Alaska State Science Standards and Grade Level Expectations adopted by the Alaska State Department of Education and Early Development (2006) for grades six through eleven are listed at

  8. Three Practical Methods for Analyzing Slope Stability

    Institute of Scientific and Technical Information of China (English)

    XU Shiguang; ZHANG Shitao; ZHU Chuanbing; YIN Ying

    2008-01-01

    Since the environmental capacity and the arable as well as the inhabitant lands have actually reached a full balance, the slopes are becoming the more and more important options for various engineering constructions. Because of the geological complexity of the slope, the design and thedecision-making of a slope-based engineering is still not ractical to rely solely on the theoretical analysis and numerical calculation, but mainly on the experience of the experts. Therefore, it hasimportant practical significance to turn some successful experience into mathematic equations. Basedupon the abundant typical slope engineering construction cases in Yunnan, Southwestern China, 3methods for yzing the slope stability have been developed in this paper. First of all, the corresponded analogous mathematic equation for analyzing slope stability has been established through case studies. Then, artificial neural network and multivariate regression analysis have alsobeen set up when 7 main influencing factors are adopted

  9. Extending HTDP to address crustal motion across Alaska

    Science.gov (United States)

    Pearson, C. F.; Snay, R.

    2008-12-01

    Deformation in the western United States, due to tectonic forces associated with the Pacific-North American plate boundary, causes ongoing changes of the positions of points on the Earth's surface . As a result, accurate surveying in the western US requires an equally accurate description of this deformation to allow survey measurements conducted at different epochs to be corrected for such movement. NOAA's National Geodetic Survey (NGS) has developed the HTDP (horizontal time dependent positioning) software that enables its users to make these corrections for the horizontal component of motion. HTDP contains a model of the secular (continuous) velocity field for the contiguous United States (from 125º to 100ºW longitude and 31º to 49ºN latitude) and separate models for the displacements associated with 28 earthquakes. The software is updated periodically to address the displacements associated with new earthquakes, most recently in June 2008 with the release version 3.0. This presentation describes a major effort to update HTDP to accurately model earth deformation in Alaska. As a start in this process, the recent release of HTDP introduced a model for the Denali Earthquake of 2002 to accompany its pre-existing model for the Prince William Sound earthquake of 1964. The Denali Earthquake produced displacements of several meters near the fault and measurable displacements throughout most of central Alaska. The dislocation model we used was developed by Elliott et al. (2007). We tested the predicted movement associated with the Denali earthquake using a set of 126 measured displacement vectors distributed over most of the interior of Alaska. The agreement between predicted and observed displacements was good with a RMS misfit of 0.1m in both the north and east components. A few large (> 1m) discrepancies were found in the vicinity of the fault trace. These discrepancies probably indicate that complex fault geometry--that no simple dislocation model can match

  10. Mathematical Model of the Identical Slope Surface

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The formation of the identical slope surface and the method of construction are discussed. Onthe basement of building the parameter equation of variable-radius circle family envelope, the frequentlyused parameter equation of the identical slope surface of the top of taper moving along column helix,horizental arc and line is built. The equation can be used to construct the identical slope surface's con-tours, gradient lines and three dimensional figures correctly.

  11. Water availability for winter wheat affected by summer fallow tillage practices in sloping dryland

    NARCIS (Netherlands)

    Wang, X.B.; Cai, D.X.; Jin, K.; Wu, H.J.; Bai, Z.G.; Zhang, C.J.; Yao, Y.Q.; Lu, J.J.; Wang, Y.H.; Yang, B.; Hartman, R.; Gabriels, D.

    2003-01-01

    The tillage experiments for winter wheat were conducted on the slope farmland in Luoyang,Henan Province in the semihumid to arid loess plateau areas of North China. Different tillage methods inclu-ding reduced tillage (RT), no-till (NT), 2 crops/year (2C), subsoiling(SS), and conventional tillage (C

  12. Mathematical modelling of stability of closing slopes in large-scale surface coal mines

    Energy Technology Data Exchange (ETDEWEB)

    Kloss, K. (Stavebni Geologie, Prague (Czechoslovakia))

    1990-05-01

    Describes methods of modelling stability of slopes of the Krusne Hory mountains in North Bohemian brown coal mines using the finite element method and a large IBM computer, with output on a Digigraph plotter. Briefly discusses results for the Merkur, Jansky and Jiretin mines, illustrating their geological profiles with diagrams of finite element networks. 4 refs.

  13. Relationship Between Climate and Tree-ring Chronology of Betula ermanii on Tree-line in North Slope of the Changbai Mountains%长白山北坡林线处岳桦年轮年表及其与气候的关系

    Institute of Scientific and Technical Information of China (English)

    王晓明; 赵秀海; 高露双; 姜庆彪

    2012-01-01

    运用相关函数及响应分析等树木年轮气候学方法,研究了长白山北坡林线处岳桦(Betula ermanii径向生长及其与气候的关系.结果表明,林线处岳桦年轮宽度年表具有较强的气候敏感性.其径向生长与上年7月和当年3月的温度显著负相关(P<0.05),与上年9月和当年7月的温度显著正相关;同时与上年6月降水量显著正相关.与季节性气候因子的响应分析表明,岳桦径向生长与当年春季(1~3月)和当年生长季前(4、5月)的平均温度呈显著负相关,与当年生长季前的平均最高温度显著正相关,与降水量的相关关系不显著.利用多元逐步回归方法模拟了岳桦年轮宽度指数与气候因子间的关系,并据此预测在温度和降水增加的背景下,林线处岳桦径向生长将降低14.8%.%The tree-ring width chronologies were developed in north slope of the Changbai Mountains to analyze the Betula ermanii radial growth-climate relationships through dendrochronological methods including correlation and response analysis. The results showed that the radial growth of Betula ermanii exhibited a significantly nagative correlation with monthly temperature of both previous July and current March (P < 0.05), a significantly positive correlation with monthly temperature of previous September and current July, and a significantly positive correlation with monthly total precipitation of previous June. Besides, the analysis of response toseasonally climatic factors showed that the tree-ring growth of B. Ermanii had a significantly negative correlation with mean temperature of current spring (January to March), a significantly negative correlation with mean temperature of the period before current growth season (April and May), and a significantly positive correlation with mean maximum temperature of the period before current growth season. But it showed no significant correlation with seasonally precipitation. Furthermore, the

  14. 伊犁河谷北坡野果林木本植物种间关系及环境解释%Interspecific and environmental relationships of woody plant species in wild fruit-tree forests on the north slope of Ili Valley

    Institute of Scientific and Technical Information of China (English)

    田中平; 庄丽; 李建贵; 程模香

    2011-01-01

    伊犁河谷北坡野果林是天山山脉中一个重要的植被类型,对其种间关系进行研究将有助于揭示野果林群落的动态特征.我们于2009年在野果林的不同群落中设置了10个样地,记录了群落的物种组成以及环境因子,包括海拔、坡度和坡向,测定了土壤含水率和有机质等土壤参数.采用x2检验、Pearson相关系数和Spearman秩相关系数检验等方法,对野果林乔木层和灌木层种间关联性进行了研究.结果表明:Pearson相关检验优于x2检验,Spearman 秩相关检验比Pearson相关检验更加灵敏;乔木和灌木优势种绝大多数种对的联结关系未达到显著水平,群落结构较为松散,表明各群落可能处于演替的早期阶段;在影响物种分布的环境因子中,海拔起决定性的作用,其次是坡向、土壤含水率、有机质、全氮和pH值.%The wild fruit-tree forest on the north slope of the Ili Valley is a living testament to the vegetative history of the Tianshan region.It is a type of broad-leaved forest appearing in the desert region.However, little is known about interspecific relationships among the major woody species or their process of succession.In 2009, we sampled 10 typical communities and investigated the abundance, height and coverage of woody plants as well as the topographical and soil conditions within each quadrat (20 m×20 m quadrats for trees, 10 m×l0 m for shrubs).Interspecific associations were analyzed using continuity corrected X2 test, Pearson correlation and Spearman rank correlation.DCCA (detrended canonical correspondence analysis) was used to identify topographical and soil factors that affected woody plant distributions.The network diagram based on Pearson's and Spearman's rank correlation coefficients displayed interspecific relationships clearly.There were negative associations among overall tree or shrub species, indicating a strong independent relationship between species.However, correlation

  15. Slope Estimation from ICESat/GLAS

    Directory of Open Access Journals (Sweden)

    Craig Mahoney

    2014-10-01

    Full Text Available We present a novel technique to infer ground slope angle from waveform LiDAR, known as the independent slope method (ISM. The technique is applied to large footprint waveforms (\\(\\sim\\ mean diameter from the Ice, Cloud and Land Elevation Satellite (ICESat Geoscience Laser Altimeter System (GLAS to produce a slope dataset of near-global coverage at \\(0.5^{\\circ} \\times 0.5^{\\circ}\\ resolution. ISM slope estimates are compared against high resolution airborne LiDAR slope measurements for nine sites across three continents. ISM slope estimates compare better with the aircraft data (R\\(^{2}=0.87\\ and RMSE\\(=5.16^{\\circ}\\ than the Shuttle Radar Topography Mission Digital Elevation Model (SRTM DEM inferred slopes (R\\(^{2}=0.71\\ and RMSE\\(=8.69^{\\circ}\\ ISM slope estimates are concurrent with GLAS waveforms and can be used to correct biophysical parameters, such as tree height and biomass. They can also be fused with other DEMs, such as SRTM, to improve slope estimates.

  16. INFLUENCES OF SLOPE GRADIENT ON SOIL EROSION

    Institute of Scientific and Technical Information of China (English)

    刘青泉; 陈力; 李家春

    2001-01-01

    The main factors influencing soil erosion include the net rain excess, the water depth, the velocity, the shear stress of overland flows , and the erosion-resisting capacity of soil. The laws of these factors varying with the slope gradient were investigated by using the kinematic wave theory. Furthermore, the critical slope gradient of erosion was driven. The analysis shows that the critical slope gradient of soil erosion is dependent on grain size , soil bulk density , surface roughness, runoff length, net rain excess, and the friction coefficient of soil, etc. The critical slope gradient has been estimated theoretically with its range between 41. 5 °~ 50°.

  17. Fuzzy Logic System for Slope Stability Prediction

    Directory of Open Access Journals (Sweden)

    Tarig Mohamed

    2012-01-01

    Full Text Available The main goal of this research is to predict the stability of slopes using fuzzy logic system. GeoStudio, a commercially available software was used to compute safety factors for various designs of slope. The general formulation of the software could analyze slope stability using various methods of analysis i.e. Morgenstern-Price, Janbu, Bishop and Ordinary to calculate the safety factors. After analyzing, fuzzy logic was used to predict the slope stability. Fuzzy logic is based on natural language and conceptually easy to understand, flexible, tolerant of imprecise data and able to model nonlinear functions of arbitrary complexity. Several important parameters such as height of slope, unit weight of slope material, angle of slope, coefficient of cohesion and internal angle of friction were used as the input parameters, while the factor of safety was the output parameter. A model to test the stability of the slope was generated from the calculated data. This model presented a relationship between input parameters and stability of the slopes. Results showed that the prediction using fuzzy logic was accurate and close to the target data.

  18. Third International Volcanological Field School in Kamchatka and Alaska

    Science.gov (United States)

    Melnikov, D.; Eichelberger, J.; Gordeev, E.; Malcolm, J.; Shipman, J.; Izbekov, P.

    2005-12-01

    The Kamchatka State University, Institute of Volcanology and Seismology FEB RAS (Petropavlovsk-Kamchatsky, Russia) and University of Alaska Fairbanks have developed an international field school focused on explosive volcanism of the North Pacific. The concept of the field school envisages joint field studies by young Russian scientists and their peers from the United States and Japan. Beyond providing first-hand experience with some of Earth's most remarkable volcanic features, the intent is to foster greater interest in language study, cultures, and ultimately in international research collaborations. The students receive both theoretical and practical knowledge of active volcanic systems, as well experience in working productively in a harsh environment. Each year, the class is offered in both Alaska and Kamchatka. The Alaska session is held in the Valley of Ten Thousand Smokes, Katmai National Park, product of the greatest volcanic eruption of the 20th century. A highlight in 2005 was the discovery of a new 70-m crater atop Trident Volcano. Also this year, we added the Great Tolbachik Eruption of 1975-76 to the itinerary of the Kamchatka school. Day trips were conducted to summit craters of New Tolbachik volcanoes and Plosky Tolbachik, Tolbachik lava flows; fumarole fields of Mutnovsky volcano, and a geothermal area and 60 MWe power plant. Students who attended both the Alaska and Kamchatka sessions could ponder the implications of great lateral separation of active vents - 10 km at Katmai and 30 km at Tolbachik - with multiple magmas and non-eruptive caldera collapse at the associated stratocones. During the evenings and on days of bad weather, the school faculty conducted lectures on various topics of volcanology in either Russian or English, with translation. The field school is a strong stimulus for growth of young volcanologists and cooperation among Russia, USA and Japan, leading naturally to longer student exchange visits and to joint research projects.

  19. Using self-organizing maps to detail synoptic connections between climate indices and Alaska weather

    Science.gov (United States)

    Winnan, Reynir C.

    Seasonal forecasts for Alaska strongly depend on the phases of Pacific Decadal Oscillation (PDO), El Nino-Southern Oscillation (ENSO), and warm water in the North Pacific called the North Pacific Mode or more popularly the "Pacific blob." The canonical descriptions of these climate indices are based on seasonal averages, and anomalies that are based on a long-term mean. The patterns highlight general geographical placement and display a sharp contrast between opposing phases, but this may be misleading since seasonal averages hide much of the synoptic variability. Self-organizing maps (SOMs) are a way of grouping daily sea level pressure (SLP) patterns, over many time realizations into a specified set of maps (e.g. 35 maps) that describe commonly occurring patterns. This study uses the SOMs in the context of climate indices to describe the range of synoptic patterns that are relevant for Alaska. This study found that the patterns common during a given phase of the PDO include subtle differences that would result in Alaska weather that is very different from what is expected from the canonical PDO description, thus providing some explanation for recent studies that find the PDO link to Alaska climate is weakening. SOMs analysis is consistent with recent studies suggesting that the pattern responsible for the 2014 Pacific warm blob is linked to tropical sea-surface temperature (SST) forcing. An analysis of the summer SLP SOMs in the context of Alaska wildland fires was also conducted. This analysis identified several commonly occurring patterns during summers with large areas burned. These patterns are characterized by low pressure in the Bering Sea, which would be consistent with increased storm activity and thus an ignition source for the fires. Identifying synoptic patterns that occur during a particular phase of a teleconnection index contributes towards understanding the mechanisms of how these indices influence the weather and climate of Alaska.

  20. Dental caries in rural Alaska Native children--Alaska, 2008.

    Science.gov (United States)

    2011-09-23

    In April 2008, the Arctic Investigations Program (AIP) of CDC was informed by the Alaska Department of Health and Social Services (DHSS) of a large number of Alaska Native (AN) children living in a remote region of Alaska who required full mouth dental rehabilitations (FMDRs), including extractions and/or restorations of multiple carious teeth performed under general anesthesia. In this remote region, approximately 400 FMDRs were performed in AN children aged Dental caries can cause pain, which can affect children's normal growth and development. AIP and Alaska DHSS conducted an investigation of dental caries and associated risk factors among children in the remote region. A convenience sample of children aged 4-15 years in five villages (two with fluoridated water and three without) was examined to estimate dental caries prevalence and severity. Risk factor information was obtained by interviewing parents. Among children aged 4-5 years and 12-15 years who were evaluated, 87% and 91%, respectively, had dental caries, compared with 35% and 51% of U.S. children in those age groups. Among children from the Alaska villages, those aged 4-5 years had a mean of 7.3 dental caries, and those aged 12-15 years had a mean of 5.0, compared with 1.6 and 1.8 dental caries in same-aged U.S. children. Of the multiple factors assessed, lack of water fluoridation and soda pop consumption were significantly associated with dental caries severity. Collaborations between tribal, state, and federal agencies to provide effective preventive interventions, such as water fluoridation of villages with suitable water systems and provision of fluoride varnishes, should be encouraged.

  1. Slope of the Slope Derivative Surface used to characterize the complexity of the seafloor around St. John, USVI

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Slope of slope was calculated from the bathymetry surface for each raster cell by applying the ArcGIS Spatial Analyst 'Slope' Tool to a previously created slope...

  2. Geologic framework of the Alaska Peninsula, southwest Alaska, and the Alaska Peninsula terrane

    Science.gov (United States)

    Wilson, Frederic H.; Detterman, Robert L.; DuBois, Gregory D.

    2015-01-01

    The Alaska Peninsula is composed of the late Paleozoic to Quaternary sedimentary, igneous, and minor metamorphic rocks that record the history of a number of magmatic arcs. These magmatic arcs include an unnamed Late Triassic(?) and Early Jurassic island arc, the early Cenozoic Meshik arc, and the late Cenozoic Aleutian arc. Also found on the Alaska Peninsula is one of the most complete nonmetamorphosed, fossiliferous, marine Jurassic sedimentary sections known. As much as 8,500 m of section of Mesozoic sedimentary rocks record the growth and erosion of the Early Jurassic island arc.

  3. Collapse of the northern Jalisco continental slope:Subduction erosion, forearc slivering, or subduction beneath the Tres Marias escarpment?

    Science.gov (United States)

    Bandy, W. L.; Mortera-Gutierrez, C. A.; Ortiz-Zamora, G.; Ortega-Ramirez, J.; Galindo Dominguez, R. E.; Ponce-Núñez, F.; Pérez-Calderón, D.; Rufino-Contreras, I.; Valle-Hernández, S.; Pérez-González, E.

    2010-12-01

    The Jalisco subduction zone exhibits several interesting characteristics. Among these is that convergence between the Rivera and North American plate is highly oblique, especially north of 20N, the obliquity progressively increasing to the NW. By analogy to other better studied subduction zones, this distribution of forces should produce a NW-SE extension in the overriding plate, especially north of 20N. This has led to the proposal that the trench perpendicular Bahia de Banderas is an expression of this extension [Kostoglodov and Bandy, JGR, vol. 100, 1995]. To further investigate this proposal, multibeam bathymetric data and seafloor backscatter images, seismic reflection sub-bottom profiles and marine magnetic data were collected during the MORTIC08 campaign of the B.O. EL PUMA in March 2009. The bathymetric data provides for 100% coverage (20 to 200 meter spacing of the actual measured depth value depending on the water depth) of the continental slope and trench areas north of 20N. These data indicate that a marked change occurs in the morphology of the continental slope at 20N. To the north the slope consists of a broad, fairly flat plain lying between a steep lower inner trench slope to the west and a steep, concave seaward, escarpment to the east. In contrast, to the south the continental slope exhibits a more gradual deepening until the steep lower inner trench slope. A prominent submarine canyon deeply incises the continental slope between these two morphotectonic domains. This canyon appears to represent the boundary between two NW-SE diverging forearc blocks or slivers, consistent with the presence of oblique convergence. In contrast, the broad, fairly flat plain is better explained by subsidence induced by subduction erosion (i.e. erosion of the base of the overriding plate underneath the continental slope area). The shoaling of the trench axis northward towards the Puerto Vallarta Graben and subsequent deepening may be related to subduction of the

  4. Landslide Hazard and Risk Assessment on the Northern Slope of Mt. Changbai, China

    Institute of Scientific and Technical Information of China (English)

    LIU Zhenghua; ZHANG Yanbin; Yoshiharu ISHIKAWA; Hiroyuki NAKAMURA

    2008-01-01

    Landslide hazard and risk assessment on the northern slope of Mt. Changbai,a well-known tourist attraction near the North Korean-Chinese border, are assessed. This study is divided into two parts, namely, landslide hazard zonation and risk assessment. The 1992 Anbalagan and Singh method of landslide hazard zonation (LHZ) was modified and used in this area. In this way, an Associative Analysis Method was used in representative areas to get a measure for controlling factors (slope gradient, relative relief, vegetation, geology, discontinuity development, weak layer thickness and ground water). For the membership degree of factor to slope failure, the middle range of limited values was used to calculate LHZ. Based on an estimation of the potential damage from slope failure,a reasonable risk assessment map was obtained using the relationship of potential damage and probable hazard to aid future planning and prediction and to avert loss of life.

  5. Change in abundance of pacific brant wintering in alaska: evidence of a climate warming effect?

    Science.gov (United States)

    Ward, D.H.; Dau, C.P.; Lee, T.; Sedinger, J.S.; Anderson, B.A.; Hines, J.E.

    2009-01-01

    Winter distribution of Pacific Flyway brant (Branta bernicla nigricans) has shifted northward from lowtemperate areas to sub-Arctic areas over the last 42 years. We assessed the winter abundance and distribution of brant in Alaska to evaluate whether climate warming may be contributing to positive trends in the most northern of the wintering populations. Mean surface air temperatures during winter at the end of the Alaska Peninsula increased about 1??C between 1963 and 2004, resulting in a 23% reduction in freezing degree days and a 34% decline in the number of days when ice cover prevents birds from accessing food resources. Trends in the wintering population fluctuated with states of the Pacific Decadal Oscillation, increasing during positive (warm) phases and decreasing during negative (cold) phases, and this correlation provides support for the hypothesis that growth in the wintering population of brant in Alaska is linked to climate warming. The size of the wintering population was negatively correlated with the number of days of strong northwesterly winds in November, which suggests that the occurrence of tailwinds favorable for migration before the onset of winter was a key factor in whether brant migrated from Alaska or remained there during winter. Winter distribution of brant on the Alaska Peninsula was highly variable and influenced by ice cover, particularly at the heavily used Izembek Lagoon. Observations of previously marked brant indicated that the Alaska wintering population was composed primarily of birds originating from Arctic breeding colonies that appear to be growing. Numbers of brant in Alaska during winter will likely increase as temperatures rise and ice cover decreases at high latitudes in response to climate warming. ?? The Arctic Institute of North America.

  6. The Probable Whole of Slope Submarine Landslides of Southeast Queensland, Australia.

    Science.gov (United States)

    Hubble, T.

    2015-12-01

    A research cruise aboard the RV Southern Surveyor (SS2013-V01) conducted in January 2013 offshore east Australia collected regional bathymetric data for the seabed of the continental margin of southern Queensland for the seabed bounded by Noosa Heads in the south and Indian Head, Fraser Island in the north. This newly mapped area presents a particularly steep portion of continental slope (5o to 10 o) that presents numerous submarine landslides, including two 'whole-of-slope' features (The Wide Bay Canyon, and Inskip Slides. The slope is also dissected by three large submarine canyons offshore northern Fraser Island, Wide Bay and Noosa Heads (i.e. the Fraser Canyons, the Wide Bay Canyon and the Noosa Canyon). Dredge and core samples were collected from slide scars in the northern, central and southern areas of the bathymetric survey area. The initial examination of the area's bathymetry, the core and dredge sample sedimentology, and determination of biostratigraphic ages for these sediment samples indicates that the larger, submarine slides present in this study area have probably been shed from the slope since the late Pliocene and that canyon incision is currently active on this portion of the slope. In one case, canyon incision is partly responsible for generating slides due to undercutting and removal of the toe of the slope. Slope sediments are dominantly comprised of hemipelagic muds but the presence of massive coarse sands and graded sands in some cores above erosion surfaces that cut into slope mud units is interpreted to indicate that areas of the southern Queensland continental slope are probably subjected to abrasion by grain-flows and turbidites comprised of shelf-derived sands and upper slope sediment. The results from this voyage confirms and extends previous work on the southeastern Australian continental margin that indicates that sediment transport from the shelf to deep water on this margin is dominated by gravity mass transport and that the margin

  7. A continental slope stability evaluation in the Zhujiang River Mouth Basin in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    LIU Ke; WANG Jianhua

    2014-01-01

    In nature, a slope stability is determined by the ratio of a sliding resistance to a slide force. The slide force of a marine deep-water continental slope is mainly affected by sediment mechanics properties, a topography, and a marine seismic. However, the sliding resistance is mainly affected by sedimentary patterns and a sedi-mentary stress history. Both of these are different from case to case, and their impact can be addressed when the data are organized in a geographic information system (GIS). The study area on the continental slope in Zhujiang River Mouth Basin in South China Sea provides an excellent opportunity to apply GIS spatial analysis technology for the evaluation of the slope stability. In this area, a continental slope topography and a three-dimension (3-D) topography mapping show a sea-floor morphology and the distribution of a slope steepness in good detail, and the sediment analysis of seabed samples and an indoor appraisal reveals the variability of a sediment density near the sea-floor surface. On the basis of the results of nine geotechnical studies of submarine study areas, it has worked out that an equivalent cyclic shear stress ratio is roughly between 0.158 and 0.933, which is mainly depending on the initial water content of sediment. A regional density, slope and level of anticipated seismic shaking information are combined in a GIS framework to yield a map that illustrates a continental slope stability zoning under the influencing factors in Zhujiang River Mouth Basin in the South China Sea. The continental slope stability evaluation can contribute to north resources development in the South China Sea, the marine functional zoning, the marine engineering con-struction and adjust measures to local conditions, at the same time also can provide references for other deep-water slope stability analysis.

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

    Science.gov (United States)

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

    2006-12-01

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

  9. Bark beetle outbreaks in western North America: causes and consequences

    Science.gov (United States)

    Bentz, Barbara; Logan, Jesse; MacMahon, James A.; Allen, Craig D.; Ayres, Matt; Berg, Edward E; Carroll, Allan; Hansen, Matt; Hicke, Jeff H.; Joyce, Linda A.; Macfarlane, Wallace; Munson, Steve; Negron, Jose; Paine, Tim; Powell, Jim; Raffa, Kenneth; Regniere, Jacques; Reid, Mary; Romme, Bill; Seybold, Steven J.; Six, Diana; Vandygriff, Jim; Veblen, Tom; White, Mike; Witcosky, Jeff; Wood, David

    2005-01-01

    Since 1990, native bark beetles have killed billions of trees across millions of acres of forest from Alaska to northern Mexico. Although bark beetle infestations are a regular force of natural change in forested ecosystems, several of the current outbreaks, which are occurring simultaneously across western North America, are the largest and most severe in recorded history.

  10. Alaska Dental Health Aide Program

    Directory of Open Access Journals (Sweden)

    Sarah Shoffstall-Cone

    2013-08-01

    Full Text Available Background. In 1999, An Oral Health Survey of American Indian and Alaska Native (AI/AN Dental Patients found that 79% of 2- to 5-year-olds had a history of tooth decay. The Alaska Native Tribal Health Consortium in collaboration with Alaska’s Tribal Health Organizations (THO developed a new and diverse dental workforce model to address AI/AN oral health disparities. Objectives. This paper describes the workforce model and some experience to date of the Dental Health Aide (DHA Initiative that was introduced under the federally sanctioned Community Health Aide Program in Alaska. These new dental team members work with THO dentists and hygienists to provide education, prevention and basic restorative services in a culturally appropriate manner. Results. The DHA Initiative introduced 4 new dental provider types to Alaska: the Primary Dental Health Aide, the Expanded Function Dental Health Aide, the Dental Health Aide Hygienist and the Dental Health Aide Therapist. The scope of practice between the 4 different DHA providers varies vastly along with the required training and education requirements. DHAs are certified, not licensed, providers. Recertification occurs every 2 years and requires the completion of 24 hours of continuing education and continual competency evaluation. Conclusions. Dental Health Aides provide evidence-based prevention programs and dental care that improve access to oral health care and help address well-documented oral health disparities.

  11. Variations of marine pore water salinity and chlorinity in Gulf of Alaska sediments (IODP Expedition 341)

    Science.gov (United States)

    März, Christian; Mix, Alan C.; McClymont, Erin; Nakamura, Atsunori; Berbel, Glaucia; Gulick, Sean; Jaeger, John; Schneider (LeVay), Leah

    2014-05-01

    Pore waters of marine sediments usually have salinities and chlorinities similar to the overlying sea water, ranging around 34-35 psu (Practical Salinity Units) and around 550 mM Cl-, respectively. This is because these parameters are conservative in the sense that they do not significantly participate in biogeochemical cycles. However, pore water studies carried out in the frame of the International Ocean Discovery Program (IODP) and its predecessors have shown that salinities and chlorinities of marine pore waters can substantially deviate from the modern bottom water composition in a number of environmental settings, and various processes have been suggested to explain these phenomena. Also during the recent IODP Expedition 341 that drilled five sites in the Gulf of Alaska (Northeast Pacific Ocean) from the deep Surveyor Fan across the continental slope to the glaciomarine shelf deposits, several occurrences of pore waters with salinities and chlorinities significantly different from respective bottom waters were encountered during shipboard analyses. At the pelagic Sites U1417 and U1418 (~4,200 and ~3,700 m water depth, respectively), salinity and chlorinity maxima occur around 20-50 m sediment depth, but values gradually decrease with increasing drilling depths (down to 30 psu in ~600 m sediment depth). While the pore water freshening at depth is most likely an effect of clay mineral dehydration due to increasing burial depth, the shallow salinity and chlorinity maxima are interpreted as relicts of more saline bottom waters that existed in the North Pacific during the Last Glacial Maximum (Adkins et al., 2002). In contrast, the glaciomarine slope and shelf deposits at Site U1419 to U1421 (~200 to 1,000 m water depth) are characterised by unexpectedly low salinitiy and chlorinity values (as low as 16 psu and 295 mM Cl-, respectively) already in very shallow sediment depths (~10 m), and their records do not show systematic trends with sediment depth. Freshening

  12. Aerial Photogrammetric Analysis of a Scree Slope and Cliff

    Science.gov (United States)

    Saunders, Greg; Galland, Olivier; Mair, Karen

    2014-05-01

    Mapping the physical features of landslide tracks provides information about factors controlling landslide movement. The increasing availability of unmanned aerial vehicles (UAV) provides the opportunity to efficiently and cost effectively map terrain. The main goal of this field study is to create a streamlined work-flow from acquisition to interpretation for the photogrammetric analysis of landslide tracks. Here an open source software package MicMac is used for ortho-image and point-cloud creation. A series of two flights were conducted over a scree (rockfall) slope in Kolsas, Norway. The slope runs roughly 500 m north-south with a maximum width of 60 m. A cliff to the west is the source area for the scree. The cliff consists of conglomerate, basalt, and porphyry from bottom to top respectively. The grain size of boulders in the scree slope apparently varies due to lateral differences in the cliff composition. The flights were completed under cloud cover and consisted of multiple lengthwise passes over the scree field. There was a minimum of 75% overlap between images. During the first flight the altitude was roughly 100 m, the camera was positioned normal to the scree (60 degrees from horizontal), and the resolution was 2.7 cm per pixel. The second flight had an altitude of 200 m, the camera orientation was 30 degrees from horizontal, and the resolution was 4.0 cm per pixel. Using the Micmac engine, Ortho-photos and Digital Elevation Models (DEM) were created for both the scree and the cliff. This data will allow for analysis of grain-size, surface roughness, grain-shape, fracture plane orientation, as well as geological mapping. Further work will focus the quantitative assessment of the significance different camera altitudes and angles have on the results. The work-flow used in this study provides a repeatable method for aerial photogrammetric surveys of scree slopes.

  13. Air pocket removal from downward sloping pipes

    NARCIS (Netherlands)

    Pothof, I.W.M.; Clemens, F.H.L.R.

    2012-01-01

    Air-water flow is an undesired condition in water pipelines and hydropower tunnels. Water pipelines and wastewater pressure mains in particular are subject to air pocket accumulation in downward sloping reaches, such as inverted siphons or terrain slopes. Air pockets cause energy losses and an assoc

  14. Internal waves and temperature fronts on slopes

    Directory of Open Access Journals (Sweden)

    S. A. Thorpe

    Full Text Available Time series measurements from an array of temperature miniloggers in a line at constant depth along the sloping boundary of a lake are used to describe the `internal surf zone' where internal waves interact with the sloping boundary. More small positive temperature time derivatives are recorded than negative, but there are more large negative values than positive, giving the overall distribution of temperature time derivatives a small negative skewness. This is consistent with the internal wave dynamics; fronts form during the up-slope phase of the motion, bringing cold water up the slope, and the return flow may become unstable, leading to small advecting billows and weak warm fronts. The data are analysed to detect `events', periods in which the temperature derivatives exceed a set threshold. The speed and distance travelled by `events' are described. The motion along the slope may be a consequence of (a instabilities advected by the flow (b internal waves propagating along-slope or (c internal waves approaching the slope from oblique directions. The propagation of several of the observed 'events' can only be explained by (c, evidence that the internal surf zone has some, but possibly not all, the characteristics of the conventional 'surface wave' surf zone, with waves steepening as they approach the slope at oblique angles.

    Key words. Oceanography: general (benthic boundary layers; limnology, Oceanography: physical (internal and inertial waves

  15. Gas hydrate dissociation structures in submarine slopes

    Energy Technology Data Exchange (ETDEWEB)

    Gidley, I.; Grozic, J.L.H. [Calgary Univ., AB (Canada). Dept. of Civil Engineering

    2008-07-01

    Studies have suggested that gas hydrates may play a role in submarine slope failures. However, the mechanics surrounding such failures are poorly understood. This paper discussed experimental tests conducted on a small-scale physical model of submarine soils with hydrate inclusions. The laboratory tests investigated the effects of slope angle and depth of burial of the hydrate on gas escape structures and slope stability. Laponite was used to model the soils due to its ability to swell and produce a clear, colorless thixotropic gel when dispersed in water. An R-11 refrigerant was used to form hydrate layers and nodules. The aim of the experiment was to investigate the path of the fluid escape structures and the development of a subsequent slip plane caused by the dissociation of the R-11 hydrates. Slope angles of 5, 10, and 15 degrees were examined. Slopes were examined using high-resolution, high-speed imaging techniques. Hydrate placement and slope inclinations were varied in order to obtain stability data. Results of the study showed that slope angle influenced the direction of travel of the escaping gas, and that the depth of burial affected sensitivity to slope angle. Theoretical models developed from the experimental data have accurately mapped deformations and stress states during testing. Further research is being conducted to investigate the influence of the size, shape, and placement of the hydrates. 30 refs., 15 figs.

  16. How vegetation reinforces soil on slopes

    NARCIS (Netherlands)

    Stokes, A.; Norris, J.E.; van Beek, L.P.H.; Bogaard, T.; Cammeraat, E.; Mickovski, S.B.; Jenner, A.; Di Iorio, A.; Fourcaud, T.; Norris, J.E.; Stokes, A.; Mickovski, S.B.; Cammeraat, E.; van Beek, R.; Nicoll, B.C.; Achim, A.

    2008-01-01

    Once the instability process e.g. erosion or landslides has been identified on a slope, the type of vegetation to best reinforce the soil can then be determined. Plants improve slope stability through changes in mechanical and hydrological properties of the root-soil matrix. The architecture of a pl

  17. Stability Analysing of Unsaturated Soil Slope

    Institute of Scientific and Technical Information of China (English)

    张士林; 邵龙潭

    2003-01-01

    The stability of unsaturated soil slope has been the hot point recently. Especially, the seeping rainfall makes losing stability of unsaturated soil slope, and causes enormous loss to the producation and safety of other people. The seeping rainfall makes volumetric water content of unsaturated soil slope changing, and the volumetric water content has directly relationship with matric suction. And matric suction also has directly relationship with the stability of unsaturated soil slope. So the change of matric suction influence the stability changing, that is, safety coefficient has decided relationship with volumetric water content. The profile of dangerous volumetric water content curves of unsaturated soil slope has been obtained. If a volumetric water content curve of some unsaturated soil slope belongs to one of these dongerous curves, the unsaturated soil slope could be in danger. So this is called DVWCCP(dangerous volumetric water content curves profile). By monitoring the volumetric water content curves can obtain the stability information of some soil slope to serve producing and safety.

  18. In-Place Randomized Slope Selection

    DEFF Research Database (Denmark)

    Blunck, Henrik; Vahrenhold, Jan

    2006-01-01

    Slope selection is a well-known algorithmic tool used in the context of computing robust estimators for fitting a line to a collection P of n points in the plane. We demonstrate that it is possible to perform slope selection in expected O(nlogn) time using only constant extra space in addition...

  19. Eastern slopes grizzly bear project

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-01-01

    The cumulative effects of human activities on the grizzly bears in the central Canadian Rockies are not well known. As a result, a project was initiated in 1994 to address the urgent requirement for accurate scientific information on the habitat and populations of grizzly bears in the area of the Banff National Park and Kananaskis Country. This area is probably the most heavily used and developed area where the grizzly still survives. The information gathered throughout the course of this study will be used to better protect and manage the bears and other sensitive carnivores in the region. Using telemetry, researchers are monitoring 25 grizzly bears which were radio-collared in a 22,000 square-kilometer area in the upper Bow Valley drainage of the eastern Alberta slopes. The researchers involved in the project are working with representatives from Husky Oil and Talisman Energy on the sound development of the Moose Mountain oil and gas field without adversely affecting the grizzly bear population. Information collected over seven years indicated that the grizzly bears have few and infrequent offspring. Using the information gathered so far, the location of the Moose Mountain to Jumping Pound pipeline was carefully selected, since the bears recover very slowly from high mortality, and also considering that the food and cover had already been compromised by the high number of roads, trails and other human activities in the area. The status of the population and habitat of the grizzly bear will be assessed upon the conclusion of the field research phase in 2001. Models will be updated using the data obtained during eight years and will assist in the understanding of complex variables that affect grizzly bears.

  20. Subducting plate geology in three great earthquake ruptures of the western Alaska margin, Kodiak to Unimak

    Science.gov (United States)

    von Huene, Roland; Miller, John J.; Weinrebe, Wilhelm

    2012-01-01

    Three destructive earthquakes along the Alaska subduction zone sourced transoceanic tsunamis during the past 70 years. Since it is reasoned that past rupture areas might again source tsunamis in the future, we studied potential asperities and barriers in the subduction zone by examining Quaternary Gulf of Alaska plate history, geophysical data, and morphology. We relate the aftershock areas to subducting lower plate relief and dissimilar materials in the seismogenic zone in the 1964 Kodiak and adjacent 1938 Semidi Islands earthquake segments. In the 1946 Unimak earthquake segment, the exposed lower plate seafloor lacks major relief that might organize great earthquake rupture. However, the upper plate contains a deep transverse-trending basin and basement ridges associated with the Eocene continental Alaska convergent margin transition to the Aleutian island arc. These upper plate features are sufficiently large to have affected rupture propagation. In addition, massive slope failure in the Unimak area may explain the local 42-m-high 1946 tsunami runup. Although Quaternary geologic and tectonic processes included accretion to form a frontal prism, the study of seismic images, samples, and continental slope physiography shows a previous history of tectonic erosion. Implied asperities and barriers in the seismogenic zone could organize future great earthquake rupture.

  1. Bryophytes from Simeonof Island in the Shumagin Islands, southwestern Alaska

    Science.gov (United States)

    Schofield, W.B.; Talbot, S. S.; Talbot, S.L.

    2004-01-01

    Simeonof Island is located south of the Alaska Peninsula in the hyperoceanic sector of the middle boreal subzone. We examined the bryoflora of Simeonof Island to determine species composition in an area where no previous collections had been reported. This field study was conducted in sites selected to represent the spectrum of environmental variation within Simeonof Island. Data were analyzed using published reports to compare bryophyte distribution patterns at three levels, the Northern Hemisphere, North America, and Alaska. A total of 271 bryophytes were identified: 202 mosses and 69 liverworts. The annotated list of species for Simeonof Island expands the known range for many species and fills distribution gaps within Hulte??n's Western Pacific Coast district. Maps and notes on the distribution of 14 significant distribution records are presented. Compared with bryophyte distribution in the Northern Hemisphere, the bryoflora of Simeonof Island primarily includes taxa of boreal (55%), temperate (20%), arctic (10%), and cosmopolitan (8%) distribution; 6% of the moss flora are western North America endemics. A description of the bryophytes present in the vegetation and habitat types is provided as is a quantitative analysis of the most frequently occurring bryophytes in crowberry heath.

  2. The Morphologic Difference between Crater Slopes with and without Gullies on Mars.

    Science.gov (United States)

    Conway, S. J.; Mangold, N.; Balme, M. R.; Ansan, V.

    2012-04-01

    Gullies on Mars are km-scale landforms that resemble small fluvial features on Earth. Their discovery [1] challenged the paradigm that over the last ~2 Ga, Mars has been a dry, frozen desert. The gullies are found commonly in the mid-latitudes, have a pole-facing preference [e.g., 2] and are found many kinds of steep slope (valley wall, dunes, etc.). We have chosen to concentrate on gullies found on impact crater interior wall slopes, as this is the most common type [2]. The aim of our study is to determine whether the morphology of crater walls with and without gullies is different. We chose three study areas, two in the southern hemisphere (where gullies are most common), Terra Cimmeria and Noachis Terra and one in the northern hemisphere, Acidalia Planum. All study areas extend over at least 30° of latitude, from ~25° to 55° North or South. We mapped all craters using the catalog of [3] as a basis. We used HRSC elevation data at better than 100 m/pix to extract the slope and curvature of crater walls in the four cardinal directions. We mapped all the gullies on crater walls in the three areas with the aid of HiRISE, MOC, CTX and HRSC images, using polygons to delimit a slope section that contained gullies. Consistent with previous investigations we found gullies concentrated around 40° latitude, with a pole-facing preference. We also found that east-facing gullies were common in both hemispheres. Gullies were most common in Terra Cimmeria and uncommon in Noachis Terra. We found that for a given latitude band and orientation gullies tend to be found on craters with the steepest slopes and the highest curvature. The lack of gullies in Noachis Terra can be explained by the lack of steep, concave slopes in the mid-latitudes of this region. In Terra Cimmeria we found that almost all steep, concave crater slopes hosted gullies, whereas in Acidalia, in the north, only 10-20% of steep concave slopes had gullies. Crater slopes with gullies in the north are steeper

  3. [Effects of slope gradient on slope runoff and sediment yield under different single rainfall conditions].

    Science.gov (United States)

    He, Ji-Jun; Cai, Qiang-Guo; Liu, Song-Bo

    2012-05-01

    Based on the field observation data of runoff and sediment yield produced by single rainfall events in runoff plots, this paper analyzed the variation patterns of runoff and sediment yield on the slopes with different gradients under different single rainfall conditions. The differences in the rainfall conditions had little effects on the variation patterns of slope runoff with the gradient. Under the conditions of six different rainfall events in the study area, the variation patterns of slope runoff with the gradient were basically the same, i. e., the runoff increased with increasing gradient, but the increment of the runoff decreased slightly with increasing gradient, which was mainly determined by the infiltration flux of atmospheric precipitation. Rainfall condition played an important role on the slope sediment yield. Generally, there existed a critical slope gradient for slope erosion, but the critical gradient was not a fixed value, which varied with rainfall condition. The critical slope gradient for slope erosion increased with increasing slope gradient. When the critical slope gradient was greater, the variation of slope sediment yield with slope gradient always became larger.

  4. Automated sliding susceptibility mapping of rock slopes

    Directory of Open Access Journals (Sweden)

    A. Günther

    2004-01-01

    Full Text Available We present a suite of extensions for ARCVIEW GIS™ (ESRI that allows to map the spatial distribution of first-order mechanical slope-properties in hard rock terrain, e.g. for large slope areas like water reservoir slopes. Besides digital elevation data, this expert-system includes regional continuous grid-based data on geological structures that might act as potential sliding or cutoff planes for rockslides. The system allows rapid automated mapping of geometrical and kinematical slope properties in hard rock, providing the basis for spatially distributed deterministic sliding-susceptibility evaluations on a pixel base. Changing hydrostatic slope conditions and rock mechanical parameters can be implemented and used for simple predictive static stability calculations. Application is demonstrated for a study area in the Harz Mts., Germany.

  5. Hypsometric control on glacier mass balance sensitivity in Alaska

    Science.gov (United States)

    McGrath, D.; Sass, L.; Arendt, A. A.; O'Neel, S.; Kienholz, C.; Larsen, C.; Burgess, E. W.

    2015-12-01

    Mass loss from glaciers in Alaska is dominated by strongly negative surface balances, particularly on small, continental glaciers but can be highly variable from glacier to glacier. Glacier hypsometry can exert significant control on mass balance sensitivity, particularly if the equilibrium line altitude (ELA) is in a broad area of low surface slope. In this study, we explore the spatial variability in glacier response to future climate forcings on the basis of hypsometry. We first derive mass balance sensitivities (30-70 m ELA / 1° C and 40-90 m ELA / 50% decrease in snow accumulation) from the ~50-year USGS Benchmark glaciers mass balance record. We subsequently assess mean climate fields in 2090-2100 derived from the IPCC AR5/CMIP5 RCP 6.0 5-model mean. Over glaciers in Alaska, we find 2-4° C warming and 10-20% increase in precipitation relative to 2006-2015, but a corresponding 0-50% decrease in snow accumulation due to rising temperatures. We assess changes in accumulation area ratios (AAR) to a rising ELA using binned individual glacier hypsometries. For an ELA increase of 150 m, the mean statewide AAR drops by 0.45, representing a 70% reduction in accumulation area on an individual glacier basis. Small, interior glaciers are the primary drivers of this reduction and for nearly 25% of all glaciers, the new ELA exceeds the glacier's maximum elevation, portending eventual loss. The loss of small glaciers, particularly in the drier interior of Alaska will significantly modify streamflow properties (flashy hydrographs, earlier and reduced peak flows, increased interannual variability, warmer temperatures) with poorly understood downstream ecosystem and oceanographic impacts.

  6. Siberian Origins of Neoproterozoic to Upper Triassic Rocks of Arctic Alaska

    Science.gov (United States)

    Clough, J. G.; Blodgett, R. B.

    2007-12-01

    Evidence for a connection of the Arctic Alaska plate (including Chukotka) with Siberia from Cambrian until Late Triassic time can be made on the basis of paleobiogeography. Arctic Alaska contains a number of biogeographically distinctive megafossils for select time intervals, notably the Middle Cambrian, Early and Late Ordovician, Early and Middle Devonian, Mississippian, and Late Triassic. Middle Cambrian trilobites are strictly Siberian in affinity, but also show close affinities with coeval trilobites from the Farewell terrane of SW Alaska. Late Ordovician brachiopods, gastropods, trilobites, and ostracodes are known from the Shublik Mountains, NE Brooks Range and York Mountains of the Seward Peninsula. Affinities are likewise primarily with Siberia (sharing the primarily Siberian pentameroid brachiopod genera Tcherskidium and Eoconchidium and the strictly Siberian trilobite genus Monorakos), but also with the Farewell terrane. Late Early Devonian and Middle Devonian brachiopods and calcareous green algae from Arctic Alaska are similarly allied with Siberia and the Farewell and Alexander terranes of southern Alaska. Early Mississippian faunas from the lower part of the Lisburne Group and underlying Endicott Group contain relatively widespread fauna, including taxa recognized both in North America and Eurasia, consistent with the relatively cosmopolitan paleobiogeographic conditions of this interval. However, Late Mississippian brachiopod fauna from the upper part of the Lisburne Group contain many brachiopods of strictly Eurasian affinities, notably the gigantoproductids, which are unknown in cratonic North America, but widespread across Eurasia and even North Africa. Late Mississippian lycopods from this terrane have previously been noted as demonstrating strong Angaran affinities. Permian faunas of Arctic Alaska show strong affinities as well with the Siberian Arctic, virtually lacking any fusilinids and reefal buildups, which in contradistinction are commonly

  7. 76 FR 303 - Alaska: Adequacy of Alaska's Municipal Solid Waste Landfill Permit Program

    Science.gov (United States)

    2011-01-04

    ... AGENCY 40 CFR Parts 239 and 258 Alaska: Adequacy of Alaska's Municipal Solid Waste Landfill Permit... proposes to approve Alaska's modification of its approved Municipal Solid Waste Landfill (MSWLF) permit... Domenic Calabro, Office of Air, Waste, and Toxics, U.S. EPA, Region 10, 1200 Sixth Avenue, Suite...

  8. 76 FR 270 - Alaska: Adequacy of Alaska Municipal Solid Waste Landfill Permit Program

    Science.gov (United States)

    2011-01-04

    ... AGENCY 40 CFR Parts 239 and 258 Alaska: Adequacy of Alaska Municipal Solid Waste Landfill Permit Program... modification to Alaska's approved Municipal Solid Waste Landfill (MSWLF) permit program. The approved... 40 CFR 258.4. III. Statutory and Executive Order Reviews This action approves State solid...

  9. 76 FR 7788 - Fisheries of the Exclusive Economic Zone off Alaska; Western Alaska Community Development Quota...

    Science.gov (United States)

    2011-02-11

    ... Economic Zone off Alaska; Western Alaska Community Development Quota Program; Recordkeeping and Reporting... fisheries of the exclusive economic zone off Alaska. The proposed revisions would add a requirement that the... scale inspections. This proposed action is necessary to update and clarify regulations and is...

  10. Fisheries Education in Alaska. Conference Report. Alaska Sea Grant Report 82-4.

    Science.gov (United States)

    Smoker, William W., Ed.

    This conference was an attempt to have the fishing industry join the state of Alaska in building fisheries education programs. Topics addressed in papers presented at the conference include: (1) fisheries as a part of life in Alaska, addressing participation of Alaska natives in commercial fisheries and national efforts; (2) the international…

  11. Near-real-time surface ocean velocities derived from HF radar stations located along coastal waters of North Slope Alaska, Puerto Rico/Virgin Islands, eastern US/Gulf of Mexico, Hawaii and western US during August 2016 (NCEI Accession 0156623)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This archival package contains near-real-time ocean surface velocities, also known as total vector velocities, derived from HF radar stations. The velocities are...

  12. Near-real-time surface ocean velocities derived from HF radar stations located along coastal waters of North Slope Alaska, Puerto Rico/Virgin Islands, eastern US/Gulf of Mexico, Hawaii and western US during August 2015 (NCEI Accession 0131989)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This archival package contains near-real-time ocean surface velocities, also known as total vector velocities, derived from HF radar stations. The velocities are...

  13. Near-real-time surface ocean velocities derived from HF radar stations located along coastal waters of North Slope Alaska, Puerto Rico/Virgin Islands, eastern US/Gulf of Mexico, Hawaii and western US during October 2015 (NCEI Accession 0138228)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This archival package contains near-real-time ocean surface velocities, also known as total vector velocities, derived from HF radar stations. The velocities are...

  14. Near-real-time surface ocean velocities derived from HF radar stations located along coastal waters of North Slope Alaska, Puerto Rico/Virgin Islands, eastern US/Gulf of Mexico, Hawaii and western US during November 2015 (NCEI Accession 0139551)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This archival package contains near-real-time ocean surface velocities, also known as total vector velocities, derived from HF radar stations. The velocities are...

  15. Near-real-time surface ocean velocities derived from HF radar stations located along coastal waters of North Slope Alaska, Puerto Rico/Virgin Islands, eastern US/Gulf of Mexico, Hawaii and western US during September 2015 (NCEI Accession 0137285)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This archival package contains near-real-time ocean surface velocities, also known as total vector velocities, derived from HF radar stations. The velocities are...

  16. Near-real-time surface ocean velocities derived from HF radar stations located along coastal waters of North Slope Alaska, Puerto Rico/Virgin Islands, eastern US/Gulf of Mexico, Hawaii and western US during July 2016 (NCEI Accession 0156399)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This archival package contains near-real-time ocean surface velocities, also known as total vector velocities, derived from HF radar stations. The velocities are...

  17. Near-real-time surface ocean velocities derived from HF radar stations located along coastal waters of North Slope Alaska, Puerto Rico/Virgin Islands, eastern US/Gulf of Mexico, Hawaii and western US during July 2015 (NCEI Accession 0131976)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This archival package contains near-real-time ocean surface velocities, also known as total vector velocities, derived from HF radar stations. The velocities are...

  18. Cretaceous to Recent extension in the Bering Strait region, Alaska

    Science.gov (United States)

    Dumitru, Trevor A.; Miller, Elizabeth L.; O'Sullivan, Paul B.; Amato, Jeffrey M.; Hannula, Kimberly A.; Calvert, Andrew T.; Gans, Phillip B.

    1995-06-01

    A key issue presented by the geology of northern Alaska concerns the demise of the Brooks Range going west toward the Bering Strait region. The main Brookian tectonic and stratigraphic elements continue into the Russian Far East, but the thick crustal root and high elevations that define the modern physiographic Brooks Range die out approaching the Bering and Chukchi shelves, which form an unusually broad area of submerged continental crust. Structural, geochronologic, and apatite fission-track data indicate that at least three episodes of extension may have affected the crust beneath the Bering Strait region, in the middle to Late Cretaceous, Eocene-early Oligocene, and Pliocene(?)-Recent. This extension may explain the present thinner crust of the region, the formation of extensive continental shelves, and the dismemberment and southward translation of tectonic elements as they are traced from the Brooks Range toward Russia. Evidence for these events is recorded within a gently tilted 10- to 15-km thick crustal section exposed on the western Seward Peninsula. The earliest episode is documented at high structural levels by the postcollision exhumation history of blueschists. Structural data indicate exhumation was accomplished in part by thinning of the crust during north-south extension bracketed between 120 and 90 Ma by 40Ar/39Ar and U-Pb ages. The Kigluaik Mountains gneiss dome rose through the crust during the later stages of this extension at 91 Ma. Similar gneiss domes occur within a broad, discontinuous belt of Cretaceous magmatism linking interior Alaska with northeast Russia; mantle-derived melts within this belt likely heated the crust and facilitated extension. Apatite fission-track ages indicate cooling below ≈120-85°C occurred sometime between 100 and 70 Ma, and the area subsequently resided at shallow crustal depths (<3-4 km) until the present. This suggests that denudation of deep levels of the crust by erosion and/or tectonism was mostly

  19. Pacific Basin tsunami hazards associated with mass flows in the Aleutian arc of Alaska

    Science.gov (United States)

    Waythomas, Christopher F.; Watts, Philip; Shi, Fengyan; Kirby, James T.

    2009-01-01

    We analyze mass-flow tsunami generation for selected areas within the Aleutian arc of Alaska using results from numerical simulation of hypothetical but plausible mass-flow sources such as submarine landslides and volcanic debris avalanches. The Aleutian arc consists of a chain of volcanic mountains, volcanic islands, and submarine canyons, surrounded by a low-relief continental shelf above about 1000–2000 m water depth. Parts of the arc are fragmented into a series of fault-bounded blocks, tens to hundreds of kilometers in length, and separated from one another by distinctive fault-controlled canyons that are roughly normal to the arc axis. The canyons are natural regions for the accumulation and conveyance of sediment derived from glacial and volcanic processes. The volcanic islands in the region include a number of historically active volcanoes and some possess geological evidence for large-scale sector collapse into the sea. Large scale mass-flow deposits have not been mapped on the seafloor south of the Aleutian Islands, in part because most of the area has never been examined at the resolution required to identify such features, and in part because of the complex nature of erosional and depositional processes. Extensive submarine landslide deposits and debris flows are known on the north side of the arc and are common in similar settings elsewhere and thus they likely exist on the trench slope south of the Aleutian Islands. Because the Aleutian arc is surrounded by deep, open ocean, mass flows of unconsolidated debris that originate either as submarine landslides or as volcanic debris avalanches entering the sea may be potential tsunami sources. To test this hypothesis we present a series of numerical simulations of submarine mass-flow initiated tsunamis from eight different source areas. We consider four submarine mass flows originating in submarine canyons and four flows that evolve from submarine landslides on the trench slope. The flows have lengths

  20. Differential erosion by different-sized glaciers as reflected in 10Be-derived erosion rates of glacier valley walls, Kichatna Mts., Alaska

    Science.gov (United States)

    Ward, D.; Anderson, R. S.

    2009-12-01

    The Kichatna Mountains, Alaska Range, Alaska comprise a dramatic landscape carved into a small ~65 Ma granitic pluton about 100 km west of Denali, in which kilometer-tall rock walls and “cathedral” spires tower over a radial array of over a dozen individual valley glaciers. The sheer scale of the relief speaks to the relative rates of valley incision by glaciers and rockwall retreat, but absolute rates are difficult to determine. We use cosmogenic 10Be to measure rockwall backwearing rates (and discuss several very important caveats to this use) on timescales of 103-104 yr, with a straightforward sampling strategy that exploits ablation-dominated medial moraines. In simple cases, a medial moraine and its associated englacial debris serve as a conveyor belt that brings supraglacial rockfall debris from the accumulation zone valley wall to a moraine crest in the ablation zone. Our samples come from the largest medial moraine on each of three glaciers. The northeast-flowing Trident glacier is the largest (15 km long, 1.4 km wide) and most deeply incised, and it has the lowest modern snowline in the range (~1200 m). Its primary medial moraine is sourced from west-facing sidewalls. The north-flowing Shadows glacier is slightly smaller (13 km long, 0.8 km wide) and has a large moraine sourced in dominantly east-facing sidewalls. The south-flowing Caldwell glacier is the smallest of the three (7 km long, 0.7 km wide), has a high modern snowline (~1500 m), and is nearly completely covered in debris. Its primary moraine is sourced from all south-facing aspects. These three glaciers share divides in their headwaters, and so are sourced in identical rock. Sidewall relief is similar (~1 km) in all three catchments. Each sample was amalgamated from 25-35 clasts collected over a 1 km longitudinal transect of each moraine. Replicate samples are internally consistent. The lowest 10Be concentrations (8000 at/g), and thus the highest inferred sidewall erosion rates (1.4 mm

  1. Reinforcement mechanism of slope stability method with no cutting trees

    OpenAIRE

    Yuki, Chikata; Harushige, KUSUMI; 楠見, 晴重; Katsumi, TERAOKA

    2008-01-01

    The study in this paper is the slope stability. Although many slopes are prone to collapse, countermeasures against slop failures have not been progressed yet in Japan. Most slope protection methods were to cover shotcrete on the slope in 1960’s. However, the slope covered shotcrete have been deteriorating. Therefore, the slope failures frequently occur due to the natural disaster such as heavy rainfall and earthquake. It is important to develop an effective slope stability method. Moreover, ...

  2. Alaska's renewable energy potential.

    Energy Technology Data Exchange (ETDEWEB)

    2009-02-01

    This paper delivers a brief survey of renewable energy technologies applicable to Alaska's climate, latitude, geography, and geology. We first identify Alaska's natural renewable energy resources and which renewable energy technologies would be most productive. e survey the current state of renewable energy technologies and research efforts within the U.S. and, where appropriate, internationally. We also present information on the current state of Alaska's renewable energy assets, incentives, and commercial enterprises. Finally, we escribe places where research efforts at Sandia National Laboratories could assist the state of Alaska with its renewable energy technology investment efforts.

  3. Northern Alaska Landscape/Permafrost GIS Data

    Data.gov (United States)

    Arctic Landscape Conservation Cooperative — This data set represents an updated Ecological Subsection Map for Northern Alaska. This update includes permafrost mapping to include the following new layers:...

  4. Transition Fault and the Yakutat-Pacific-North American Triple Junction

    Science.gov (United States)

    Gulick, S. P.; Christeson, G. L.; Norton, I. O.; Pavlis, T. L.; Reece, R.; van Avendonk, H.; Worthington, L. L.

    2011-12-01

    In the Gulf of Alaska the Pacific Plate, Yakutat Terrane, and North American Plate interact in a complexly deformed zone on the continental slope near Kayak Island. This zone can be viewed as a fault-trench-trench (FTT) triple junction that can only be stable if the two trench segments are aligned. In this case the trench segments are: the deformation front along which the Pacific Plate subducts beneath North America (the Aleutian Trench) and the deformation front along which the Yakutat Terrane subducts at a more westerly direction (when compared to the Pacific subduction) beneath North America (the Pamplona Zone). These two deformation fronts are, to a first order, locally aligned. The complex member of the system is the Transition Fault which is a long-lived strike-slip fault separating the 15-30 km thick Yakutat oceanic plateau crust from the 5-7 km thick Pacific Plate crust, which is itself deforming along the north-south trending Gulf of Alaska Shear Zone (GASZ). A series of seismic reflection profiles crossing the Transition Fault allow us to examine the evolution of deformation as a function of proximity to the triple junction. East of the triple junction and the GASZ, the Transition Fault is a single near vertical strike-slip zone. Moving west to the area where the GASZ interacts with the Transition Fault, three seismic profiles show that the Fault bifurcates into a southern transpressional strand with a few 100 meters of seafloor relief and a northern strike-slip dominated strand. West of the GASZ and within the region proximal to the triple junction, two seismic lines show that the Transition Fault is expressed as a southern transpressional structure with significant amounts shortening (seafloor expression increased to ~1.8 km) and a northern dominantly strike-slip fault with minor transpression. Mapping the top of basement shows that the southern arm lies within and deforms the Pacific oceanic crust with the top of ocean crust reflection to the north

  5. MECHANICAL HARVESTING OF COFFEE IN HIGH SLOPE

    Directory of Open Access Journals (Sweden)

    FELIPE SANTINATO

    2016-01-01

    Full Text Available Brazilian coffee farming is carried out both on flat and steep lands. In flat areas, mechanized operations are intensive; however, in steep slope areas, certain mechanized operations cannot be performed, such as harvesting. Based on this, the industry has developed machinery to harvest coffee in areas with up to 30% slope. However, harvesters have their efficiency and operational performance influenced by land slope. Thus, this study aimed to evaluate the operational performance and harvesting efficiency of a steep-slope harvester under different situations, using different speed settings. The experiment was carried out in the county of Santo Antônio do Amparo, state of Minas Gerais, Brazil, using five coffee stands with 10, 15, 20, 25 and 30% slope. Evaluations were performed with a self-propelled harvester (Electron, TDI®, Araguari, MG, Brazil at three rotation speeds (600, 800 and 1.000 rpm and two ground speeds (800 and 1.000 m h-1. The results showed the lower speed (800 m h-1 was suitable for 10% slope areas since the amount of fallen coffee berries. For areas of 20% slope, harvesting time was 21.6% longer than in flatter areas. Downtime varied from 10.66 to 29.18% total harvest due to a higher number of maneuvers.

  6. Evaluation of gas production potential from gas hydrate deposits in National Petroleum Reserve Alaska using numerical simulations

    Science.gov (United States)

    Nandanwar, Manish S.; Anderson, Brian J.; Ajayi, Taiwo; Collett, Timothy S.; Zyrianova, Margarita V.

    2016-01-01

    An evaluation of the gas production potential of Sunlight Peak gas hydrate accumulation in the eastern portion of the National Petroleum Reserve Alaska (NPRA) of Alaska North Slope (ANS) is conducted using numerical simulations, as part of the U.S. Geological Survey (USGS) gas hydrate Life Cycle Assessment program. A field scale reservoir model for Sunlight Peak is developed using Advanced Processes & Thermal Reservoir Simulator (STARS) that approximates the production design and response of this gas hydrate field. The reservoir characterization is based on available structural maps and the seismic-derived hydrate saturation map of the study region. A 3D reservoir model, with heterogeneous distribution of the reservoir properties (such as porosity, permeability and vertical hydrate saturation), is developed by correlating the data from the Mount Elbert well logs. Production simulations showed that the Sunlight Peak prospect has the potential of producing 1.53 × 109 ST m3 of gas in 30 years by depressurization with a peak production rate of around 19.4 × 104 ST m3/day through a single horizontal well. To determine the effect of uncertainty in reservoir properties on the gas production, an uncertainty analysis is carried out. It is observed that for the range of data considered, the overall cumulative production from the Sunlight Peak will always be within the range of ±4.6% error from the overall mean value of 1.43 × 109 ST m3. A sensitivity analysis study showed that the proximity of the reservoir from the base of permafrost and the base of hydrate stability zone (BHSZ) has significant effect on gas production rates. The gas production rates decrease with the increase in the depth of the permafrost and the depth of BHSZ. From the overall analysis of the results it is concluded that Sunlight Peak gas hydrate accumulation behaves differently than other Class III reservoirs (Class III reservoirs are composed of a single layer of hydrate with no

  7. ANIMALS - INDIVIDUAL - COUNTS, Displacement Volume, TAXONOMIC CODE, SPECIES IDENTIFICATION - SEX and species abundance tows data collected in the Gulf of Alaska and North Pacific Ocean on the CHARTER/FISHING BOATS cruises GP0401-01 and GP0401-02 as part of the NEP project from 2004-10-19 to 2004-11-08 (NODC Accession 0115259)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0115259 includes tows and biological data collected aboard the CHARTER/FISHING BOATS during cruises GP0401-01 and GP0401-02 in the Gulf of Alaska and...

  8. Initial Results from a Study of Climatic Changes and the Effect on Wild Sheep Habitat in Selected Study Areas of Alaska

    Science.gov (United States)

    Pfeifer, Edwin; Ruhlman, Jana; Middleton, Barry; Dye, Dennis; Acosta, Alex

    2010-01-01

    data bases relating to Dall sheep habitats in selected study areas. Alaska's sheep habitats are typified by long, narrow bands of mountainous uplifts generally arrayed west-to-east, and perpendicular to prevailing south-to-north weather-front movements. Classic Dall sheep habitat occurs on snow-shadowed slopes within these narrow mountainous habitats. On the basis of these data, we offer an explanatory hypothesis relating Dall sheep welfare to weather and climate-influenced nutrition and a monitoring scheme, which should produce data sufficient to test the robustness of this hypothesis. If correlated with population changes, the methods used in our comparative observations may provide long-term monitoring tools for wildlife managers and be applicable in other widely-dispersed wild sheep habitats. If no significant correlations emerge from our modeling exercises, the notion that wild sheep are a sufficiently sensitive species to be seen as an indicator species will have to be reexamined.

  9. Four new species of Haplosclerida (Porifera, Demospongiae) from the Aleutian Islands, Alaska.

    Science.gov (United States)

    Lehnert, Helmut; Stone, Robert P

    2013-01-01

    Four new species of Haplosclerida are described from the Aleutian Islands, Alaska: Callyspongia mucosa n.sp., Cladocroce infundibulum n. sp., Cladocroce attu n. sp. and Cladocroce kiska n. sp. The new species are described and compared to congeners of the region. This is the northernmost record of the genus Callyspongia and the first record of the subgenus Callyspongia from the North Pacific Ocean. To accommodate Cladocroce kiska in its genus the definition has to be broadened to allow sigmas.

  10. 1964 Great Alaska Earthquake: a photographic tour of Anchorage, Alaska

    Science.gov (United States)

    Thoms, Evan E.; Haeussler, Peter J.; Anderson, Rebecca D.; McGimsey, Robert G.

    2014-01-01

    On March 27, 1964, at 5:36 p.m., a magnitude 9.2 earthquake, the largest recorded earthquake in U.S. history, struck southcentral Alaska (fig. 1). The Great Alaska Earthquake (also known as the Good Friday Earthquake) occurred at a pivotal time in the history of earth science, and helped lead to the acceptance of plate tectonic theory (Cox, 1973; Brocher and others, 2014). All large subduction zone earthquakes are understood through insights learned from the 1964 event, and observations and interpretations of the earthquake have influenced the design of infrastructure and seismic monitoring systems now in place. The earthquake caused extensive damage across the State, and triggered local tsunamis that devastated the Alaskan towns of Whittier, Valdez, and Seward. In Anchorage, the main cause of damage was ground shaking, which lasted approximately 4.5 minutes. Many buildings could not withstand this motion and were damaged or collapsed even though their foundations remained intact. More significantly, ground shaking triggered a number of landslides along coastal and drainage valley bluffs underlain by the Bootlegger Cove Formation, a composite of facies containing variably mixed gravel, sand, silt, and clay which were deposited over much of upper Cook Inlet during the Late Pleistocene (Ulery and others, 1983). Cyclic (or strain) softening of the more sensitive clay facies caused overlying blocks of soil to slide sideways along surfaces dipping by only a few degrees. This guide is the document version of an interactive web map that was created as part of the commemoration events for the 50th anniversary of the 1964 Great Alaska Earthquake. It is accessible at the U.S. Geological Survey (USGS) Alaska Science Center website: http://alaska.usgs.gov/announcements/news/1964Earthquake/. The website features a map display with suggested tour stops in Anchorage, historical photographs taken shortly after the earthquake, repeat photography of selected sites, scanned documents

  11. Model slope infiltration experiments for shallow landslides early warning

    Science.gov (United States)

    Damiano, E.; Greco, R.; Guida, A.; Olivares, L.; Picarelli, L.

    2009-04-01

    simple empirical models [Versace et al., 2003] based on correlation between some features of rainfall records (cumulated height, duration, season etc.) and the correspondent observed landslides. Laboratory experiments on instrumented small scale slope models represent an effective way to provide data sets [Eckersley, 1990; Wang and Sassa, 2001] useful for building up more complex models of landslide triggering prediction. At the Geotechnical Laboratory of C.I.R.I.AM. an instrumented flume to investigate on the mechanics of landslides in unsaturated deposits of granular soils is available [Olivares et al. 2003; Damiano, 2004; Olivares et al., 2007]. In the flume a model slope is reconstituted by a moist-tamping technique and subjected to an artificial uniform rainfall since failure happens. The state of stress and strain of the slope is monitored during the entire test starting from the infiltration process since the early post-failure stage: the monitoring system is constituted by several mini-tensiometers placed at different locations and depths, to measure suction, mini-transducers to measure positive pore pressures, laser sensors, to measure settlements of the ground surface, and high definition video-cameras to obtain, through a software (PIV) appositely dedicated, the overall horizontal displacement field. Besides, TDR sensors, used with an innovative technique [Greco, 2006], allow to reconstruct the water content profile of soil along the entire thickness of the investigated deposit and to monitor its continuous changes during infiltration. In this paper a series of laboratory tests carried out on model slopes in granular pyroclastic soils taken in the mountainous area north-eastern of Napoli, are presented. The experimental results demonstrate the completeness of information provided by the various sensors installed. In particular, very useful information is given by the coupled measurements of soil water content by TDR and suction by tensiometers. Knowledge of

  12. Assessment of undiscovered petroleum resources of the Arctic Alaska Petroleum Province

    Science.gov (United States)

    Houseknecht, David W.; Bird, Kenneth J.; Garrity, Christopher P.

    2012-01-01

    The Arctic Alaska Petroleum Province encompasses all lands and adjacent continental shelf areas north of the Brooks Range-Herald arch tectonic belts and south of the northern (outboard) margin of the Alaska rift shoulder. Even though only a small part is thoroughly explored, it is one of the most prolific petroleum provinces in North America, with total known resources (cumulative production plus proved reserves) of about 28 billion barrels of oil equivalent. For assessment purposes, the province is divided into a platform assessment unit, comprising the Alaska rift shoulder and its relatively undeformed flanks, and a fold-and-thrust belt assessment unit, comprising the deformed area north of the Brooks Range and Herald arch tectonic belts. Mean estimates of undiscovered, technically recoverable resources include nearly 28 billion barrels of oil and 122 trillion cubic feet of nonassociated gas in the platform assessment unit and 2 billion barrels of oil and 59 trillion cubic feet of nonassociated gas in the fold-and-thrust belt assessment unit.

  13. ElevationOther_SLOPE10M

    Data.gov (United States)

    Vermont Center for Geographic Information — Used ElevationDEM_DEM10M and the Arc/Info SLOPE command with the "PERCENT_RISE" and ".3048" Z_unit options to create this data layer. Input source dataset is...

  14. Percent Agricultural Land Cover on Steep Slopes

    Data.gov (United States)

    U.S. Environmental Protection Agency — Clearing land for agriculture tends to increase soil erosion. The amount of erosion is related to the steepness of the slope, farming methods used and soil type....

  15. On Front Slope Stability of Berm Breakwaters

    DEFF Research Database (Denmark)

    Burcharth, Hans F.

    2013-01-01

    The short communication presents application of the conventional Van der Meer stability formula for low-crested breakwaters for the prediction of front slope erosion of statically stable berm breakwaters with relatively high berms. The method is verified (Burcharth, 2008) by comparison with the r......The short communication presents application of the conventional Van der Meer stability formula for low-crested breakwaters for the prediction of front slope erosion of statically stable berm breakwaters with relatively high berms. The method is verified (Burcharth, 2008) by comparison...... test results including tests presented in Sigurdarson and Van der Meer (2011) are discussed. A proposal is presented for performance of new model tests with the purpose of developing more accurate formulae for the prediction of front slope erosion as a function of front slope, relative berm height...

  16. Multi-scale Evidence of Large CO2 and CH4 Emissions from Permafrost During Spring Thaw in Northern Alaska

    Science.gov (United States)

    Raz Yaseef, N.; Torn, M. S.; Billesbach, D. P.; Wu, Y.; Kneafsey, T. J.; Romanovsky, V. E.; Cook, D. R.; Commane, R.; Henderson, J.; Miller, C. E.; Wullschleger, S. D.

    2015-12-01

    Arctic warming will amplify climate change especially if thawing tundra emits increasingly greater amounts of CO2 and CH4 due to rising temperatures in the coming decades. However, uncertainties about flux rates and sources limit the prediction of these feedbacks. The few observations of tundra carbon fluxes during snowmelt suggest that there may be large releases during spring thaw, but little is known about the underlying mechanisms and whether emissions of greenhouse gases are widespread enough to influence atmospheric concentrations. To address this question we employed a multi-scale approach, including ecosystem-scale measurements, a mechanistic soil-core thawing experiment, and airborne observations of atmospheric carbon concentrations. We show that fluxes during the 2-week period of snow and surface-ice melt in 2014 near Barrow, Alaska, reduced the net snow-free season uptake of CO2 by 46% and added 6% to the CH4 emissions. A controlled laboratory experiment revealed that when frozen permafrost was exposed to warming temperatures, it released an immediate, large pulse of CO2 and CH4 that had been trapped under the surface ice. While the Alaskan North Slope was undergoing snowmelt, changes in the concentrations of CO2 and CH4 measured by aircraft were correlated to fluxes of CO2 and CH4 measured by eddy-covariance. Airborne measurements from the aircraft reflected local observations, and confirmed that the pulse had influence on regional atmospheric concentrations. This research suggests that the Arctic carbon spring pulse is a result of a delayed release of biogenic production in fall, and that this pulse is widespread and large enough to offset a significant fraction of the moderate Arctic tundra carbon sink.

  17. Investigation of gas hydrate-bearing sandstone reservoirs at the Mount Elbert stratigraphic test well, Milne Point, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Boswell, R. [United States Dept. of Energy, Morgantown, WV (United States). National Energy Technology Lab; Hunter, R. [ASRC Energy Services, Anchorage, AK (United States); Collett, T. [United States Geological Survey, Denver, CO (United States); Digert, S.; Weeks, M. [BP Exploration Alaska Inc., Anchorage, AK (United States); Hancock, S. [RPS Energy Canada, Calgary, AB (Canada)

    2008-07-01

    Gas hydrates occur within the shallow sand reservoirs on the Alaska North Slope (ANS). The mean estimate for gas hydrate in-place resources on the ANS is 16.7 trillion cubic metres. In the past, they were viewed primarily as a drilling hazard to be managed during the development of deeper oil resources. In 2002, a cooperative research program was launched to help determine the potential for environmentally-sound and economically-viable production of methane from gas hydrates. Additional objectives were to refine ANS gas hydrate resource potential, improve the geologic and geophysical methods used to locate and asses gas hydrate resources, and develop numerical modeling capabilities that are essential in both planning and evaluating gas hydrate field programs. This paper reviewed the results of the an extensive data collection effort conducted at the Mount Elbert number 1 gas hydrates stratigraphic test well on the ANS. The 22-day field program acquired significant gas hydrate-bearing reservoir data, including a suite of open-hole well logs, over 500 feet of continuous core, and open-hole formation pressure response tests. The logging program confirmed the existence of approximately 30 m of gas hydrate saturated, fine-grained sand reservoir. Gas hydrate saturations were observed to range from 60 to 75 per cent. Continuous wire-line coring operations achieved 85 per cent recovery. The Mount Elbert field program also involved gas and water sample collection. It demonstrated the ability to safely and efficiently conduct a research-level open-hole data acquisition program in shallow, sub-permafrost sediments and increased confidence in gas hydrate resource assessment methodologies for the ANS. 10 refs., 9 figs.

  18. Relationships between hyperspectral data and components of vegetation biomass in Low Arctic tundra communities at Ivotuk, Alaska

    Science.gov (United States)

    Bratsch, Sara; Epstein, Howard; Buchhorn, Marcel; Walker, Donald; Landes, Heather

    2017-02-01

    Warming in the Arctic has resulted in a lengthening of the growing season and changes to the distribution and composition of tundra vegetation including increased biomass quantities in the Low Arctic. Biomass has commonly been estimated using broad-band greenness indices such as NDVI; however, vegetation changes in the Arctic are occurring at spatial scales within a few meters. The aim of this paper is to assess the ability of hyperspectral remote sensing data to estimate biomass quantities among different plant tissue type categories at the North Slope site of Ivotuk, Alaska. Hand-held hyperspectral data and harvested biomass measurements were collected during the 1999 growing season. A subset of the data was used as a training set, and was regressed against the hyperspectral bands using LASSO. LASSO is a modification of SPLS and is a variable selection technique that is useful in studies with high collinearity among predictor variables such as hyperspectral remote sensing. The resulting equations were then used to predict biomass quantities for the remaining Ivotuk data. The majority of significant biomass-spectra relationships (65%) were for shrubs categories during all times of the growing season and bands in the blue, green, and red edge wavelength regions of the spectrum. The ability to identify unique biomass-spectra relationships per community is decreased at the height of the growing season when shrubs obscure lower-lying vegetation such as mosses. The results of this study support previous research arguing that shrubs are dominant controls over spectral reflectance in Low Arctic communities and that this dominance results in an increased ability to estimate shrub component biomass over other plant functional types.

  19. Potential emigration of Siberian cattle germplasm on Chirikof Island, Alaska

    Indian Academy of Sciences (India)

    M. D. MACNEIL; L. J. ALEXANDER; J. KANTANEN; I. A. AMMOSOV; Z. I. IVANOVA; R. G. POPOV; M. OZEROV; A. MILLBROOKE; M. A. CRONIN

    2017-03-01

    Feral cattle residing in Chirikof Island, Alaska, are relatively distinct from breeds used in commercial production in North America. However, preliminary evidence suggested that they exhibit substantial genetic relationship with cattle fromYakutian region of Siberia. Thus, our objective was to further elucidate quantify the origins, admixture and divergence of the Chirikof Island cattle relative to cattle from Siberia and USA. Subject animals were genotyped at 15 microsatellite loci.Compared with Turano–Mongolian and North American cattle, Chirikof Island cattle had similar variation, with slightly less observed heterozygosity, fewer alleles per locus and a positive fixation index. Analysis of the genetic distances revealed two primary clusters; one that contained the North American breeds and the Kazakh White head, and a second that contained the Yakutian and Kalmyk breeds, and the Chirikof population. Thus, it is suggested that Chirikof Island cattle may be a composite of British breeds emanating from North America and Turano–Mongolian cattle. A potential founder effect, consistent withhistorical records of the Russian–American period, may contribute to the adaptation of the Chirikof Island cattle to their harsh high-latitude environment. Further study of adaptive mechanisms manifest by these cattle is warranted.

  20. Numerical Computation of Homogeneous Slope Stability

    Directory of Open Access Journals (Sweden)

    Shuangshuang Xiao

    2015-01-01

    Full Text Available To simplify the computational process of homogeneous slope stability, improve computational accuracy, and find multiple potential slip surfaces of a complex geometric slope, this study utilized the limit equilibrium method to derive expression equations of overall and partial factors of safety. This study transformed the solution of the minimum factor of safety (FOS to solving of a constrained nonlinear programming problem and applied an exhaustive method (EM and particle swarm optimization algorithm (PSO to this problem. In simple slope examples, the computational results using an EM and PSO were close to those obtained using other methods. Compared to the EM, the PSO had a small computation error and a significantly shorter computation time. As a result, the PSO could precisely calculate the slope FOS with high efficiency. The example of the multistage slope analysis indicated that this slope had two potential slip surfaces. The factors of safety were 1.1182 and 1.1560, respectively. The differences between these and the minimum FOS (1.0759 were small, but the positions of the slip surfaces were completely different than the critical slip surface (CSS.

  1. Prediction of slope failure due to earthquake

    Institute of Scientific and Technical Information of China (English)

    CHEN XiaoLi; KATO Nobuaki; TSUNAKI Ryosuke; MUKAI Keiji

    2009-01-01

    The earthquake-triggered landslides and slope failures are common phenomena during strong earthquakes and have drawn more attention from the world because of severe hazards they induced.These hazards usually cannot be prevented by current mitigating measures,thus,it becomes more and more important to develop a precise technique for the risk assessment of earthquake-induced failures in the mountainous area.The application of discrimination analysis method is proved to be successful and effective in the prediction of earthquake-triggered landslides and slope failures in the region of Imokawa Basin in Japan.Diacriminant score can be used to assess the relative risk of slope failures,as the score increases,the possibility of slope failures occurrence increases accordingly.At the same time,the variables in the judgement formula,such as slope gradient,slope curvature and seismic peak ground acceleration,are easy to obtain.This advantage makes this method more practical and manipulable than others at present.In order to apply this method more effectively,there are still several problems to resolve.

  2. Preliminary assessment report for Camp Carroll Training Center, Installation 02045, Anchorage, Alaska. Installation Restoration Program

    Energy Technology Data Exchange (ETDEWEB)

    Krokosz, M.; Sefano, J.

    1993-08-01

    This report presents the results of the preliminary assessment (PA) conducted by Argonne National Laboratory at the Alaska Army National Guard property known as Camp Carroll Training Center, located on the Fort Richardson Army facility near Anchorage, Alaska. Preliminary assessments of federal facilities are being conducted to compile the information necessary for the completion of preremedial activities and to provide a basis for establishing, corrective actions in response to releases of hazardous substances. The principal objective of the PA is to characterize the site accurately and determine the need for further action by examining site activities, types and quantities of hazardous substances used, the nature and amounts of wastes generated or stored at the facility, and potential pathways by which contamination could affect public health and the environment. The primary environmentally significant operations (ESOs) associated with the property are (1) the Alaska Air National Guard storage area behind Building S57112 (Organizational Maintenance Shop [OMS] 6); (2) the state of Alaska maintenance facility and the soil/tar-type spill north of the state of Alaska maintenance facility; (3) the waste storage area adjacent to OMS 6; (4) the contaminated area from leaking underground storage tanks (USTs) and the oil-water separator; and (5) soil staining in the parking area at the Camp Carroll Headquarters Building. Camp Carroll appears to be in excellent condition from an environmental standpoint, and current practices are satisfactory. Argonne recommends that the Alaska Department of Military Affairs consider remediation of soil contamination associated with all storage areas, as well as reviewing the practices of other residents of the facility. Argonne also recommends that the current methods of storing waste material behind Building S57112 (OMS 6) be reviewed for alternatives.

  3. 77 FR 16314 - Alaska Disaster #AK-00024

    Science.gov (United States)

    2012-03-20

    ... ADMINISTRATION Alaska Disaster AK-00024 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a notice of an Administrative declaration of a disaster for the State of Alaska dated 03/13/2012... INFORMATION CONTACT: A. Escobar, Office of Disaster Assistance, U.S. Small Business Administration, 409...

  4. 78 FR 39822 - Alaska Disaster #AK-00028

    Science.gov (United States)

    2013-07-02

    ... ADMINISTRATION Alaska Disaster AK-00028 AGENCY: U.S. Small Business Administration. ACTION: Notice SUMMARY: This is a Notice of the Presidential declaration of a major disaster for the State of Alaska (FEMA-4122-DR... INFORMATION CONTACT: A. Escobar, Office of Disaster Assistance, U.S. Small Business Administration, 409...

  5. Biomarker based reconstruction of Pleistocene climate and environmental conditions in the Gulf of Alaska: Preliminary results obtained from IODP Expedition 341 sediments

    Science.gov (United States)

    Müller, Juliane; Sanchez Montes, Maria Luisa; McClymont, Erin; Stein, Ruediger; Fahl, Kirsten; Mangelsdorf, Kai; Wilkes, Heinz; 341 Scientists, Expedition

    2014-05-01

    A remarkable sedimentary record that extends from the Miocene to the late Pleistocene/Holocene has been drilled during IODP Expedition 341 (May - July 2013) in the Gulf of Alaska. The recovery and examination of sediments along a transect of five drill sites (U1417 - U1421) from the deep ocean towards the continental slope and shelf offshore the St. Elias Mountains enables the reconstruction of the palaeoceanographic and environmental development in the NE Pacific during a period of significant global cooling and directly addresses the overall research objectives of the IODP programme. The knowledge about palaeo sea surface conditions and their relation to climate changes in the subpolar NE Pacific is relatively scarce and mainly confined to the past 17 ka BP (Barron et al., 2009; Davies et al., 2011; Addison et al., 2012). Biomarker based reconstructions of the sea surface conditions (i.e. sea surface temperature (SST), sea ice coverage, marine primary productivity) that characterised the subpolar NE Pacific during critical time intervals of Plio- and Pleistocene climate change may provide new information on oceanic and atmospheric feedback mechanisms and further enable the identification of teleconnections between the palaeoceanographic evolution in the North Pacific and the North Atlantic. Here we present preliminary biomarker data obtained from sediments from the distal deepwater site U1417 and the proximal site U1419 located at the Gulf of Alaska continental slope. Variability in the distribution and abundance of short- and long-chain n-alkanes, sterols, and C25-highly branched isoprenoids (HBIs) is interpreted to reflect changes in the environmental setting. These data provide insight in marine primary productivity changes (in response to cooling and warming intervals) and the variable input of terrigenous organic matter via meltwater and/or iceberg discharge events. The C25-HBI diene/triene ratio - hitherto used as a sea ice proxy in the Southern Ocean

  6. Feature of resistivity response of slope from steady to unsteady

    Institute of Scientific and Technical Information of China (English)

    谢忠球; 张玉池; 温佩琳; 段靓靓

    2008-01-01

    Using resistivity as index and referring to the law about effect of slope to resistivity,the apparent resistivities of geophysical model concerned with unsteady rock type slope failure were calculated systematically by using the boundary integral equation method.After studying the feature of resistivity response of slope failure,the variety of resistivity during evolution of slope from steady to unsteady was found and the characteristics of resistivity response about slope failure was concluded.These make electrical exploring method for detecting the slip plane or structural plane of slope failure,evaluating the stability of the slope,and forecasting slope failure become true.

  7. Decision Guide for Roof Slope Selection

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, T.R.

    1988-01-01

    This decision guide has been written for personnel who are responsible for the design, construction, and replacement of Air Force roofs. It provides the necessary information and analytical tools for making prudent and cost-effective decisions regarding the amount of slope to provide in various roofing situations. Because the expertise and experience of the decision makers will vary, the guide contains both basic slope-related concepts as well as more sophisticated technical data. This breadth of information enables the less experienced user to develop an understanding of roof slope issues before applying the more sophisticated analytical tools, while the experienced user can proceed directly to the technical sections. Although much of this guide is devoted to the analysis of costs, it is not a cost-estimating document. It does, however, provide the reader with the relative costs of a variety of roof slope options; and it shows how to determine the relative cost-effectiveness of different options. The selection of the proper roof slope coupled with good roof design, a quality installation, periodic inspection, and appropriate maintenance and repair will achieve the Air Force's objective of obtaining the best possible roofing value for its buildings.

  8. Serologic survey of Toxoplasma gondii in grizzly bears (Ursus arctos) and black bears (Ursus americanus), from Alaska, 1988 to 1991.

    Science.gov (United States)

    Chomel, B B; Zarnke, R L; Kasten, R W; Kass, P H; Mendes, E

    1995-10-01

    We tested 644 serum samples from 480 grizzly bears and 40 black bears from Alaska (USA), collected between 1988 and 1991, for Toxoplasma gondii antibodies, using a commercially available latex agglutination test (LAT). A titer > or = 64 was considered positive. Serum antibody prevalence for T. gondii in grizzly bears (Ursus arctos) was 18% (87 of 480). Prevalence ranged from 9% (seven of 77) on Kodiak Island to 28% (15 of 54) in northern Alaska. Prevalence was directly correlated to age. No grizzly bears grizzly bears captured north of the Arctic Circle. Antibody prevalence in black bears (Ursus americanus) from Interior Alaska was 15% (six of 40), similar to the prevalence in grizzly bears from the same area (13%; five of 40).

  9. Going coastal: Shared evolutionary history between coastal British Columbia and Southeast Alaska wolves (canis lupus)

    Science.gov (United States)

    Weckworth, B.V.; Dawson, N.G.; Talbot, S.L.; Flamme, M.J.; Cook, J.A.

    2011-01-01

    Background: Many coastal species occupying the temperate rainforests of the Pacific Northwest in North America comprise endemic populations genetically and ecologically distinct from interior continental conspecifics. Morphological variation previously identified among wolf populations resulted in recognition of multiple subspecies of wolves in the Pacific Northwest. Recently, separate genetic studies have identified diverged populations of wolves in coastal British Columbia and coastal Southeast Alaska, providing support for hypotheses of distinct coastal subspecies. These two regions are geographically and ecologically contiguous, however, there is no comprehensive analysis across all wolf populations in this coastal rainforest. Methodology/Principal Findings: By combining mitochondrial DNA datasets from throughout the Pacific Northwest, we examined the genetic relationship between coastal British Columbia and Southeast Alaska wolf populations and compared them with adjacent continental populations. Phylogenetic analysis indicates complete overlap in the genetic diversity of coastal British Columbia and Southeast Alaska wolves, but these populations are distinct from interior continental wolves. Analyses of molecular variation support the separation of all coastal wolves in a group divergent from continental populations, as predicted based on hypothesized subspecies designations. Two novel haplotypes also were uncovered in a newly assayed continental population of interior Alaska wolves. Conclusions/Significance: We found evidence that coastal wolves endemic to these temperate rainforests are diverged from neighbouring, interior continental wolves; a finding that necessitates new international strategies associated with the management of this species. ?? 2011 This is an open-access article.

  10. Going coastal: shared evolutionary history between coastal British Columbia and Southeast Alaska wolves (Canis lupus.

    Directory of Open Access Journals (Sweden)

    Byron V Weckworth

    Full Text Available BACKGROUND: Many coastal species occupying the temperate rainforests of the Pacific Northwest in North America comprise endemic populations genetically and ecologically distinct from interior continental conspecifics. Morphological variation previously identified among wolf populations resulted in recognition of multiple subspecies of wolves in the Pacific Northwest. Recently, separate genetic studies have identified diverged populations of wolves in coastal British Columbia and coastal Southeast Alaska, providing support for hypotheses of distinct coastal subspecies. These two regions are geographically and ecologically contiguous, however, there is no comprehensive analysis across all wolf populations in this coastal rainforest. METHODOLOGY/PRINCIPAL FINDINGS: By combining mitochondrial DNA datasets from throughout the Pacific Northwest, we examined the genetic relationship between coastal British Columbia and Southeast Alaska wolf populations and compared them with adjacent continental populations. Phylogenetic analysis indicates complete overlap in the genetic diversity of coastal British Columbia and Southeast Alaska wolves, but these populations are distinct from interior continental wolves. Analyses of molecular variation support the separation of all coastal wolves in a group divergent from continental populations, as predicted based on hypothesized subspecies designations. Two novel haplotypes also were uncovered in a newly assayed continental population of interior Alaska wolves. CONCLUSIONS/SIGNIFICANCE: We found evidence that coastal wolves endemic to these temperate rainforests are diverged from neighbouring, interior continental wolves; a finding that necessitates new international strategies associated with the management of this species.

  11. Deformation during terrane accretion in the Saint Elias orogen, Alaska

    Science.gov (United States)

    Bruhn, R.L.; Pavlis, T.L.; Plafker, G.; Serpa, L.

    2004-01-01

    The Saint Elias orogen of southern Alaska and adjacent Canada is a complex belt of mountains formed by collision and accretion of the Yakutat terrane into the transition zone from transform faulting to subduction in the northeast Pacific. The orogen is an active analog for tectonic processes that formed much of the North American Cordillera, and is also an important site to study (1) the relationships between climate and tectonics, and (2) structures that generate large- to great-magnitude earthquakes. The Yakutat terrane is a fragment of the North American plate margin that is partly subducted beneath and partly accreted to the continental margin of southern Alaska. Interaction between the Yakutat terrane and the North American and Pacific plates causes significant differences in the style of deformation within the terrane. Deformation in the eastern part of the terrane is caused by strike-slip faulting along the Fairweather transform fault and by reverse faulting beneath the coastal mountains, but there is little deformation immediately offshore. The central part of the orogen is marked by thrusting of the Yakutat terrane beneath the North American plate along the Chugach-Saint Elias fault and development of a wide, thin-skinned fold-and-thrust belt. Strike-slip faulting in this segment may he localized in the hanging wall of the Chugach-Saint Elias fault, or dissipated by thrust faulting beneath a north-northeast-trending belt of active deformation that cuts obliquely across the eastern end of the fold-and-thrust belt. Superimposed folds with complex shapes and plunging hinge lines accommodate horizontal shortening and extension in the western part of the orogen, where the sedimentary cover of the Yakutat terrane is accreted into the upper plate of the Aleutian subduction zone. These three structural segments are separated by transverse tectonic boundaries that cut across the Yakutat terrane and also coincide with the courses of piedmont glaciers that flow from

  12. Morphometric interpretation of the northwest and southeast slopes of Tenerife, Canary Islands

    Science.gov (United States)

    1997-01-01

    occurs within the deposit. Although the avalanche and associated debris flow surfaces on the northwest slope appear pristine, being only partially covered by lava flow from a volcano in one of the channels, those on the southeast slope are partially buried by postfailure volcanics and detrital sediments. At the distal end of the slope failure masses, there are extensive fans. On the southeast slope these depocenters were reworked into a sediment drift field of northeast trending ridges by the southerly flowing North Atlantic Deep Water. On the surfaces of the fans off the northwest slope, there are exotic blocks transported downslope from their original positions either by riding on the surface of the highly dense debris avalanche or by being transported within the avalanche itself.

  13. Asteroid absolute magnitudes and slope parameters

    Science.gov (United States)

    Tedesco, Edward F.

    1991-01-01

    A new listing of absolute magnitudes (H) and slope parameters (G) has been created and published in the Minor Planet Circulars; this same listing will appear in the 1992 Ephemerides of Minor Planets. Unlike previous listings, the values of the current list were derived from fits of data at the V band. All observations were reduced in the same fashion using, where appropriate, a single basis default value of 0.15 for the slope parameter. Distances and phase angles were computed for each observation. The data for 113 asteroids was of sufficiently high quality to permit derivation of their H and G. These improved absolute magnitudes and slope parameters will be used to deduce the most reliable bias-corrected asteroid size-frequency distribution yet made.

  14. Assessment of Slope Instability and Risk Analysis of Road Cut Slopes in Lashotor Pass, Iran

    Directory of Open Access Journals (Sweden)

    Mohammad Hossein Taherynia

    2014-01-01

    Full Text Available Assessment of the stability of natural and artificial rock slopes is an important topic in the rock mechanics sciences. One of the most widely used methods for this purpose is the classification of the slope rock mass. In the recent decades, several rock slope classification systems are presented by many researchers. Each one of these rock mass classification systems uses different parameters and rating systems. These differences are due to the diversity of affecting parameters and the degree of influence on the rock slope stability. Another important point in rock slope stability is appraisal hazard and risk analysis. In the risk analysis, the degree of danger of rock slope instability is determined. The Lashotor pass is located in the Shiraz-Isfahan highway in Iran. Field surveys indicate that there are high potentialities of instability in the road cut slopes of the Lashotor pass. In the current paper, the stability of the rock slopes in the Lashotor pass is studied comprehensively with different classification methods. For risk analyses, we estimated dangerous area by use of the RocFall software. Furthermore, the dangers of falling rocks for the vehicles passing the Lashotor pass are estimated according to rockfall hazard rating system.

  15. Reliability analysis method applied in slope stability: slope prediction and forecast on stability analysis

    Institute of Scientific and Technical Information of China (English)

    Wenjuan ZHANG; Li CHEN; Ning QU; Hai'an LIANG

    2006-01-01

    Landslide is one kind of geologic hazards that often happens all over the world. It brings huge losses to human life and property; therefore, it is very important to research it. This study focused in combination between single and regional landslide, traditional slope stability analysis method and reliability analysis method. Meanwhile, methods of prediction of slopes and reliability analysis were discussed.

  16. Hyperspectral surveying for mineral resources in Alaska

    Science.gov (United States)

    Kokaly, Raymond F.; Graham, Garth E.; Hoefen, Todd M.; Kelley, Karen D.; Johnson, Michaela R.; Hubbard, Bernard E.

    2016-07-07

    Alaska is a major producer of base and precious metals and has a high potential for additional undiscovered mineral resources. However, discovery is hindered by Alaska’s vast size, remoteness, and rugged terrain. New methods are needed to overcome these obstacles in order to fully evaluate Alaska’s geology and mineral resource potential. Hyperspectral surveying is one method that can be used to rapidly acquire data about the distributions of surficial materials, including different types of bedrock and ground cover. In 2014, the U.S. Geological Survey began the Alaska Hyperspectral Project to assess the applicability of this method in Alaska. The primary study area is a remote part of the eastern Alaska Range where porphyry deposits are exposed. In collaboration with the Alaska Division of Geological and Geophysical Surveys, the University of Alaska Fairbanks, and the National Park Service, the U.S. Geological Survey is collecting and analyzing hyperspectral data with the goals of enhancing geologic mapping and developing methods to identify and characterize mineral deposits elsewhere in Alaska.

  17. Research on monitoring system for slope deformation

    Institute of Scientific and Technical Information of China (English)

    LIU Xiao-sheng; ZHANG Xue-zhuang; WANG Ai-gong

    2007-01-01

    The monitoring system for slope deformation which bases on Leica (TCA series)was researched and developed. This system consists of electronic total stations, high precision thermometer, digital barometer, photoelectric frequency adjustor and other related instruments and data collection and processing software. The system can monitor a series of targets automatically to obtain accurate data of distance at predetermined time, besides,it can timely display targets' coordinates and deformation value, velocity, etc. in graph as well. To compare of the results of different monitoring time, we can find the problems of mine slope deformation rapidly and accurately.

  18. The Sloping Land Conversion Program in China

    DEFF Research Database (Denmark)

    Liu, Zhen

    conversion program. Our results show that SLCP works as a valid external policy intervention on rural livelihood diversification. In addition, the findings demonstrate that there exist heterogeneous effects of SLCP implementation on livelihood diversification across different rural income groups. The lower......By overcoming the barriers that limit access to financial liquidity and human resource, the Sloping Land Conversion Program (SLCP) can promote rural livelihood diversification. This paper examines this effect using a household survey data set spanning the 1999 implementation of the Sloping land...... income group was more affected by the program in terms of income diversification....

  19. Survey of Indoor Air Quality in the University of Alaska

    DEFF Research Database (Denmark)

    Kotol, Martin; Craven, Colin; Rode, Carsten

    2014-01-01

    In cold climates living inside the heated space requires considerable amounts of heat. With the intention to decrease the heating demand, people are insulating their homes and make them more air tight. With the natural infiltration being brought close to zero there has been an increase of a new...... problem which is poor indoor air quality (IAQ). During summer 2012 four student homes were built in Fairbanks, Alaska as a part of Sustainable Village project. The aim of this project is to promote sustainable ways of living in the Arctic and to study new technologies and their applicability in the cold...... north. This paper presents the results of an IAQ survey performed in the homes during two weeks in December 2012. During this survey the air temperature, relative humidity (RH) and CO2 concentration were measured in all occupied bedrooms along with monitoring of the ventilation units. The results have...

  20. Volcanic tremor and plume height hysteresis from Pavlof Volcano, Alaska.

    Science.gov (United States)

    Fee, David; Haney, Matthew M; Matoza, Robin S; Eaton, Alexa R; Cervelli, Peter; Schneider, David J; Iezzi, Alexandra M

    2017-01-06

    The March 2016 eruption of Pavlof Volcano, Alaska, produced an ash plume that caused the cancellation of more than 100 flights in North America. The eruption generated strong tremor that was recorded by seismic and remote low-frequency acoustic (infrasound) stations, including the EarthScope Transportable Array. The relationship between the tremor amplitudes and plume height changes considerably between the waxing and waning portions of the eruption. Similar hysteresis has been observed between seismic river noise and discharge during storms, suggesting that flow and erosional processes in both rivers and volcanoes can produce irreversible structural changes that are detectable in geophysical data. We propose that the time-varying relationship at Pavlof arose from changes in the tremor source related to volcanic vent erosion. This relationship may improve estimates of volcanic emissions and characterization of eruption size and intensity.

  1. Alaska LandCarbon wetland distribution map

    Science.gov (United States)

    Wylie, Bruce K.; Pastick, Neal J.

    2017-01-01

    This product provides regional estimates of specific wetland types (bog and fen) in Alaska. Available wetland types mapped by the National Wetlands Inventory (NWI) program were re-classed into bog, fen, and other. NWI mapping of wetlands was only done for a portion of the area so a decision tree mapping algorithm was then developed to estimate bog, fen, and other across the state of Alaska using remote sensing and GIS spatial data sets as inputs. This data was used and presented in two chapters on the USGS Alaska LandCarbon Report.

  2. Submarine landslides along the eastern Mediterranean Israeli continental slope - a possible source for tsunami

    Science.gov (United States)

    Katz, O.; Reuven, E.; Aharonov, E.

    2013-12-01

    Numerous shallow submarine slope failures (scars and deposits) are observed in recent high resolution bathymetric grids of the continental slope off the Israeli eastern Mediterranean coast. The nature of these slope failures is currently not comprehensively understood as well as the question of whether the eastern Mediterranean continental slope is continuously or episodically unstable. This question is relevant to tsunami hazard along the densely populated eastern Mediterranean shores. We report here first steps towards understanding the present state of this submarine landslide system, which include mapping and analyzing the geology of the landslides and the hosting slopes. The continental slope extends from water depths of about 150 to more than 1000 meters with a slope of less than 5 degrees in general. Bathymetric grids with pixel resolution of 15 m till water depth of 700 m and 50 m till water depth of 1700 m were used. Analyzing the bathymetry revealed three main submarine surface features on the continental slope: (a) numerous shallow landslides, within the upper sequence of the post-Messenian sediments. Landslide widths range between hundreds to thousand of meters at the scar, with scar heights up to hundred meters. The toes of the landslides are not always mapable and lay up to a few kilometers down slope from the scar. Slope angles within the scars are 5 degrees to more than 15 degrees. In general landslides size decreases from south to north where their head scar depth turns to be shallower northwards. At least two types of landslides were detected: presumably young slides with sharp scars and presumably old slides with secondary slides and secondary drainage systems developed within the scar area; (b) a few kilometers long, north striking step-like lineaments. Step heights are up to 100 meters and the slopes are up to 20 degrees. The offset between parallel steps is less than a kilometer to a few kilometers. Analyzing seismic lines, the steps are

  3. INITIAL SLOPE OF THE HYSTERESIS CURVE

    OpenAIRE

    Gerritsma, G.J.; Stam, M.T.H.C.W.; Lodder, J. C.; Popma, Th.J.A.

    1988-01-01

    An analytical expression for the initial slope T of the hysteresis curve is derived for a stripe domain structure in a thin magnetic film, giving that T-1 is proportional to t-1/2 (t = film thickness). This is confirmed by measurements on RF sputtered CoCr films with 20 nm ≤ t ≤ 950 nm.

  4. Initial slope of the hysteresis curve

    NARCIS (Netherlands)

    Gerritsma, G.J.; Stam, M.T.H.C.W.; Lodder, J.C.; Popma, Th.J.A.

    1988-01-01

    An analytical expression for the initial slope T of the hysteresis curve is derived for a stripe domain structure in a thin magnetic film, giving that T-1 is proportional to t-1/2 (t = film thickness). This is confirmed by measurements on RF sputtered CoCr films with 20 nm £ t £ 950 nm.

  5. Level-Slope-Curvature - Fact or Artefact?

    NARCIS (Netherlands)

    R. Lord (Roger); A.A.J. Pelsser (Antoon)

    2005-01-01

    textabstractThe first three factors resulting from a principal components analysis of term structure data are in the literature typically interpreted as driving the level, slope and curvature of the term structure. Using slight generalisations of theorems from total positivity, we present sufficient

  6. Improved wavefront reconstruction algorithm from slope measurements

    Science.gov (United States)

    Phuc, Phan Huy; Manh, Nguyen The; Rhee, Hyug-Gyo; Ghim, Young-Sik; Yang, Ho-Soon; Lee, Yun-Woo

    2017-03-01

    In this paper, we propose a wavefront reconstruction algorithm from slope measurements based on a zonal method. In this algorithm, the slope measurement sampling geometry used is the Southwell geometry, in which the phase values and the slope data are measured at the same nodes. The proposed algorithm estimates the phase value at a node point using the slope measurements of eight points around the node, as doing so is believed to result in better accuracy with regard to the wavefront. For optimization of the processing time, a successive over-relaxation method is applied to iteration loops. We use a trial-and-error method to determine the best relaxation factor for each type of wavefront in order to optimize the iteration time and, thus, the processing time of the algorithm. Specifically, for a circularly symmetric wavefront, the convergence rate of the algorithm can be improved by using the result of a Fourier Transform as an initial value for the iteration. Various simulations are presented to demonstrate the improvements realized when using the proposed algorithm. Several experimental measurements of deflectometry are also processed by using the proposed algorithm.

  7. A Novel Way To Practice Slope.

    Science.gov (United States)

    Kennedy, Jane B.

    1997-01-01

    Presents examples of using a tic-tac-toe format to practice finding the slope and identifying parallel and perpendicular lines from various equation formats. Reports the successful use of this format as a review in both precalculus and calculus classes before students work with applications of analytic geometry. (JRH)

  8. Slope stability and erosion control: Ecotechnological solutions

    NARCIS (Netherlands)

    Norris, J.E.; Stokes, A.; Mickovski, S.B.; Cammeraat, E.; van Beek, R.; Nicoll, B.C.; Achim, A.

    2008-01-01

    This book is designed to assist the civil and geotechnical engineer, geomorphologist, forester, landscape architect or ecologist in choosing ecotechnological solutions for slopes that are prone to a variety of mass movements e.g. shallow failure or erosion. Within this book, the 'engineer' is used i

  9. Arctic Animals of Alaska. First Grade Activity. Schools of California Online Resources for Education (SCORE): Connecting California's Classrooms to the World.

    Science.gov (United States)

    Boe, Sandra

    The Arctic is covered with ice and snow for most of the year. Animals that live in Alaska's arctic region must be able to survive long winters and very cold temperatures. Surprisingly, many animals live in the harsh, cold climate. This first-grade activity plan helps students learn about the animals of the far north. The plan gives six steps for…

  10. Assessment of the impact of a Trans-Alaska Pipeline oil spill on the birds and mammals of the Atigun River system

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — An oil spill resulting from a crack in the Trans-Alaska Pipeline was discovered on June 10, 1979 near pipeline mile post 166, on the north side of Atigun Pass....

  11. Slope Stability Assessment of the Sarcheshmeh Landslide, Northeast Iran, Investigated Using InSAR and GPS Observations

    Directory of Open Access Journals (Sweden)

    Mahdi Motagh

    2013-07-01

    Full Text Available The detection and monitoring of mass movement of susceptible slopes plays a key role in mitigating hazards and potential damage associated with creeping slopes and landslides. In this paper, we use observations from both Interferometric Synthetic Aperture Radar (InSAR and Global Positioning System (GPS to assess the slope stability of the Sarcheshmeh ancient landslide in the North Khorasan province of northeast Iran. InSAR observations were obtained by the time-series analysis of Envisat SAR images covering 2004–2006, whereas repeated GPS observations were conducted by campaign measurements during 2010–2012. Surface displacement maps of the Sarcheshmeh landslide obtained from InSAR and GPS are both indicative of slope stability. Hydrogeological analysis suggests that the multi-year drought and lower than average precipitation levels over the last decade might have contributed to the current dormancy of the Sarcheshmeh landslide.

  12. Summer Monsoon and Annual Variability of Sea Surface Slope and Their Effects on Alongshore Current near Qingdao

    Institute of Scientific and Technical Information of China (English)

    蒲书箴; 程军; 张义钧; 石强; 骆敬新; 范文静

    2004-01-01

    Based on the monthly mean sea level data obtained from 3 years′ (1999-2001) tide-gauge measurements, the annual variability of the sea level near Qingdao and Jiaozhou Bay is studied and discussed in this paper. Results show that the sea surface height at all the tide gauges becomes higher in summer than that in winter,with an obvious seasonal variability.Furthermore the sea surface height measured at a short distance outside the bay is lower than that in thebay, showing a sea surface slope downward from north to south. The reasons for the formation of the slope are explained as well, The dynamic action ofthe summer monsoon and the sea surface slope, and their effects on the monthly mean current are studied by means of dynamics principles. The importance of the summer monsoon and the pressure gradient generated by the sea surface slope, with their effects on the alongshore current, is pointed out and emphasized in this paper.

  13. Geodetic Imaging of Glacio-Seismotectonic Processes in Southern Alaska

    Science.gov (United States)

    Sauber, J.; Bruhn, R.; Forster, R.; Hofton, M.

    2008-12-01

    Across southern Alaska the northwest directed motion of the Pacific plate is accompanied by migration and collision of the Yakutat terrane. The Yakutat terrane is a fragment of the North American plate margin that is partly subducted beneath and partly accreted to the continental margin. Over the last couple of decades the rate of ongoing deformation associated with subduction and a locked main thrust zone has been estimated by geodetic measurements. In the last five years more extensive geodetic measurements, structural and tectonic field studies, thermochronolgy, and high-resolution lidar have been acquired and analyzed as part of the STEEP project [Pavlis et al., 2006]. The nature and magnitude of accretion and translation on upper crustal faults and folds remains uncertain, however, due to complex variations in the style of tectonic deformation, pervasive and changing glaciation, and the logistical challenges of conducting field studies in formidable topography. In this study, we analyze new high-resolution lidar data to extract locations, geometry, and heights of seismogenic faults and zones of active folding across the Malaspina-Seward-Bagley region of the southern Alaska plate boundary that is hypothesized to accommodate upper crustal shortening and right-lateral slip. Airborne Topographic Mapper (ATM) lidar swath data acquired by Krabill et al. in the summer of 2005 and ICESat data (1993-present) cross a number of proposed faults and folds partially masked by glaciation, including the Malaspina thrust, Esker Creek, Chugach-St.Elias thrust, and Contact. Focal mechanisms from this region indicate mostly shallow (0-30 km) thrust and oblique strike-slip faulting. Similarly, rupture in the 1979 St. Elias earthquake (M=7.4) started as a shallow, north-dipping thrust that later changed to more steeply NE dipping with a large right-lateral strike-slip component. Additionally, we are using the morphology and dynamics of glaciers derived from L-Band SAR ice

  14. Depositional settings, correlation, and age carboniferous rocks in the western Brooks Range, Alaska

    Science.gov (United States)

    Dumoulin, J.A.; Harris, A.G.; Blome, C.D.; Young, L.E.

    2004-01-01

    The Kuna Formation (Lisburne Group) in northwest Alaska hosts the Red Dog and other Zn-Pb-Ag massive sulfide deposits in the Red Dog district. New studies of the sedimentology and paleontology of the Lisburne Group constrain the setting, age, and thermal history of these deposits. In the western and west-central Brooks Range, the Lisburne Group includes both deep- and shallow-water sedimentary facies and local volcanic rocks that are exposed in a series of thrust sheets or allochthons. Deep-water facies in the Red Dog area (i.e., the Kuna Formation and related rocks) are found chiefly in the Endicott Mountains and structurally higher Picnic Creek allochthons. In the Red Dog plate of the Endicott Mountains allochthon, the Kuna consists of at least 122 m of thinly interbedded calcareous shale, calcareous spiculite, and bioclastic supportstone (Kivalina unit) overlain by 30 to 240 m of siliceous shale, mudstone, calcareous radiolarite, and calcareous lithic turbidite (Ikalukrok unit). The Ikalukrok unit in the Red Dog plate hosts all massive sulfide deposits in the area. It is notably carbonaceous, is generally finely laminated, and contains siliceous sponge spicules and radiolarians. The Kuna Formation in the Key Creek plate of the Endicott Mountains allochthon (60-110 m) resembles the Ikalukrok unit but is unmineralized and has thinner carbonate layers that are mainly organic-rich dolostone. Correlative strata in the Picnic Creek allochthon include less shale and mudstone and more carbonate (mostly calcareous spiculite). Conodonts and radiolarians indicate an age range of Osagean to early Chesterian (late Early to Late Mississippian) for the Kuna in the Red Dog area. Sedimentologic, faunal, and geochemical data imply that most of the Kuna formed in slope and basin settings characterized by anoxic or dysoxic bottom water and by local high productivity. Shallow-water facies of th e Lisburne Group in the Red Dog area are present locally in the Endicott Mountains

  15. Geology of the Johnson River Area Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The vegetation, topography, and geology of the Johnson River area are representative of the entire eastern interior region of Alaska. This area has a vegetational...

  16. Permafrost Soils Database for Northern Alaska 2014

    Data.gov (United States)

    Arctic Landscape Conservation Cooperative — This database contains soil and permafrost stratigraphy for northern Alaska compiled from numerous project data files and reports. The Access Database has main data...

  17. Seward, Alaska 3 arc-second DEM

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 3 arc-second Seward Alaska Elevation Grid provides bathymetric data in ASCII raster format of 2.67-second resolution in geographic coordinates. This grid is...

  18. Aerial Gamma-Ray Surveys in Alaska

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Data generated by aerial sensing of radiation emanating from the earth's surface in Alaska provides general estimates of the geographic distribution of Uranium,...

  19. Alaska East-West Deflections (DEFLEC96)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' x 4' surface deflection of the vertical grid for Alaska is the DEFLEC96 model. The computation used about 1.1 millionterrestrial and marine gravity data held...

  20. Fish and wildlife research in Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Problems, information needs, research facilities, current research, and documents related to long term planning of fish and wildlife research in Alaska. Appendices...