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  • Breeding biology of storm-petrels at Wooded Islands, Alaska

    Quinlan, Susan E. (1979-12)
    Fork-tailed and Leach’s Storm-Petrels were studied at Wooded Islands, Alaska, 59°52‘ N, 147°25’W, to document and compare their breeding biology. Measurements of both species from California to the Aleutian Islands showed clinal variation; current subspecies divisions are not justified. Fork-tailed Storm-Petrels nested in a wider variety of habitats, arrived earlier at night, nested earlier, and fledged young in a shorter period than Leach’s Storm-Petrels, apparently because of their different oceanic distributions. River otter predation was the major cause of nest failures. Nesting success was higher within an exclosure than in areas exposed to predation. Predation was greater at low than high nest densities, and greater in soil than in rock habitat. Continued otter predation may decimate soil-nesting populations. Fork-tailed Storm-Petrel chick growth patterns did not vary between habitats, or nest densities. Mid- and late hatched fork-tail chicks grew faster, attained heavier weights, and had shorter nestling periods than early hatched chicks.
  • Porphyry copper, copper skarn, and volcanogenic massive sulfide occurrences in the Chandalar copper district, Alaska

    Nicholson, Lisa; Keskinen, Mary (1990-05)
    Metamorphosed porphyry copper, copper skarn, and volcanogenic massive sulfide (VMS) occurrences have been found in 5 key prospects within Devonian rocks of the Chandalar copper district, Alaska. The Venus, Victor, Eva, and Evelyn Lee prospects contain "proximal" porphyry copper/copper skarn mineralization, whereas the Luna prospect contains "distal" Cu-Zn skarn and Cu-Zn VMS mineralization. Porphyry copper mineralization is recognized by granodiorite composition meta-intrusives; zoned potassic, sericitic and propylitic alteration; and del34S values of -1.5 to -0.6 per mil. Skarns consist of andraditic garnet (Ad30-100) and diopsidic pyroxene (Hd9-46), and have del34S values of -4.7 to -1.1 per mil. Alteration types in intrusive rocks and adjacent skarn are generally compatible. VMS occurrences contain chloritic and silicic alteration, and massive sulfides have del34S values of -0.8 to 6.9 per mil, consistent with values from known Devonian VMS deposits.
  • Use of Social Media By Alaskan Libraries

    Kingsley, Ilana (2018-11-19)
    This paper summarizes a survey study of the use of social media by school, public, and academic libraries in Alaska. Librarians at 243 Alaskan libraries were contacted and asked to participate in the study; 83 librarians responded by taking the survey. Results show that public libraries are heavily engaged in social media; academic libraries regularly use social media; and some school libraries use social media but many face school district restrictions on usage. The top reasons Alaskan libraries use social media is to promote library news and events; promote specific resources; and promote specific services. Reasons for not using social media include: not having enough time; social media isn’t deemed as important; and poor Internet connectivity in rural communities. Social media platforms are selected based on librarian preference and comfort level, as opposed to audience characteristics. Libraries that aren’t under prohibitive restrictions, such as policies against using social media or poor internet/bandwidth issues, should frequently reassess their use of social media platforms to best engage with patrons and the community.
  • The kinetics of glucose limited growth by a marine yeast

    McNab, Allen David (1969-05)
    The kinetics of glucose limited growth by a marine yeast, shown to be a Rhodotorula species, have been studied in a continuous culture apparatus. The saturation constant, in synthetic media, has been calculated to be 0.25 mg/l, on the assumption that saturation kinetics are followed, The maximum growth rate was determined in both synthetic media, and artificial sea water. On the basis of inhibition kinetics, the kinetic behavior of this yeast in the marine environment has been predicted. The effect of temperature on the maximum growth rate has been determined and, on the assumption of a similar effect on the saturation constant, the saturation constant has been postulated to be in agreement with similar values determined for other microorganisms.
  • Picture Alaska: an index

    Drazan, Joseph; Burke, Joseph A. (Elmer E. Rasmuson Library, University of Alaska, 1974)
  • Elmer E. Rasmuson Papers, 1898-2000

    Morris, Lisa M. (Archives and Manuscripts, Alaska and Polar Regions Collections, Elmer E. Rasmuson Library, University of Alaska Fairbanks, 2005-12)
  • Alaska Natives: a guide to current reference sources in the Rasmuson Library

    Goniwiecha, Mark C. (Elmer E. Rasmuson Library, University of Alaska - Fairbanks, 1985)
  • Guide to the Mike Gravel Papers, 1957-1980

    Tabbert, Barbara M. (Alaska and Polar Regions Department, Elmer E. Rasmuson Library, University of Alaska - Fairbanks, 1986)
  • The changing vista of the northern Northwest Coast Indian Deer Ritual

    Austin, Kenneth Frank (1999-08)
    From time immemorial until the start of the 20th century, when disputing Tlingits decided to end a conflict, Tlingit clan leaders and elders met in council and negotiated an equitable peace settlement. After reaching a satisfactory negotiation, a peace dance took place to validate the settlement. Besides the Tlingits, the neighboring Indian groups in Southeast Alaska and British Columbia practiced this custom. When the European and Western powers assumed governance, the deer ritual--a judicial function of the Pacific Northwest Coast Indians--was modified, and new forms appeared. Presently, while elders know their regional history, many do not remember the protocol and formalities of the rite that was performed. This thesis undertakes a step into the past when the rite had an active and viable purpose in settling disputes and validating agreements
  • Small spatial and fast temporal ionosphere -magnetosphere coupling processes

    Zhu, Hua; Otto, Antonius (2000)
    I have developed a two-dimensional, three-fluid model (electrons, ions and neutrals) to simulate small-scale magnetosphere-ionosphere coupling processes. The code includes ionization and recombination processes, the Hall term in Ohm's law, and various heat sources in the energy equations. The electro-dynamic response and the evolution of the collision frequencies are treated self-consistently in a height resolved ionosphere. The model allows for the propagation of Alfven waves. The simulation is particularly suited for fast temporal variations and small spatial scale ionospheric structures associated with filamentary aurora and ionospheric heating experiments (e.g. HAARP). I have investigated the evolution of field-aligned currents in the magnetosphere-ionosphere system and found several notable effects---ion heating due to plasma-neutral friction, electron heating resulting from energetic particle precipitation and ohmic dissipation by strong field-aligned currents. The simulation of plasma. heating in the ionosphere is motivated by a specific auroral event that was simultaneously observed with optical and radar instruments. The results indicate that a consistent explanation of this event requires ohmic heating of electrons in a strong field-aligned electric current layer. They suggest strongly that the observed sequence of events can be explained only if spatial structure is present in the ionosphere so that it requires at least a two-dimensional model. Electron heating in strong field-aligned currents also provides a mechanism to deposit energy in the F-region of ionosphere and thus can explain the formation of tall auroral arcs. The simulation of the formation of field-aligned currents shows a strong plasma density depletion in the region of downward field-aligned current layer. The depletion is due to the divergent flow of the plasma. Similarly, the plasma density increases in the region of upward field-aligned current because of the convergent plasma motion. A modification of the ionospheric conditions by localized particle precipitation has an interesting effect. At the edge of the precipitation region, a new field-aligned current filament is formed. Finally, the simulation code is not limited by steady state assumptions commonly used for the Hall model and Pedersen conductivities.
  • Modeling of Arctic stratus cloud formation and the maintenance of the cloudy Arctic boundary layer

    Zhang, Qiuqing; Stamnes, Knut; Harrington, Jerry; Sentman, Davis; Watkins, Brenton (1999)
    The formation of Arctic stratus clouds (ASCs) and the maintenance of the cloudy Arctic boundary layer are studied with two models: a one-dimensional radiative-convective model and a three-dimensional large eddy simulation (LES) model. The one-dimensional radiative-convective model consists of a comprehensive radiative module, a cloud parameterization with detailed microphysics and a convective adjustment scheme. The model is designed specifically for studying ASC formation. With this model, the roles of radiation and cloud microphysics in the formation of ASCs and multiple cloud layers are investigated. The simulations reproduce both single and multiple cloud layers that were observed with inversions of temperature and humidity occurring near the cloud top. The detailed cloud microstructure produced by the model also compares well with the observations. The physics of the formation of both single and multiple cloud layers is investigated. Radiative cooling plays a key role during the initial stage of cloud formation in a atmosphere. It leads to a continual temperature decrease promoting water vapor condensation on available cloud condensation nuclei. The vertical distribution of humidity and temperature determines the radiative cooling and eventually where and when the cloud forms. The observed temperature inversion may also be explained by radiative cooling. The three-dimensional LES model is adopted to evaluate the one-dimensional model, especially the convective adjustment scheme. The advantages and limitations of the one-dimensional model are discussed. The LES results suggest that the convective adjustment scheme is capable of capturing the main features of the vertical heat and moisture fluxes in the cloudy Arctic boundary layer. The LES model is also used to investigate the maintenance of the cloudy Arctic boundary layer. The turbulence in the cloudy Arctic boundary layer is primarily maintained by the buoyancy effect due to the cloud top cooling. It is found that weak large scale downward motion aids in cloud development and maintenance.
  • Single and multiple electromagnetic scattering by size -shape distributions of small nonspherical particles

    Schulz, Frank Michael (1998)
    A comprehensive model for light scattering by size-shape distributions of randomly oriented nonspherical particles is developed. The model uses spheroids as model particles. The vector Helmholtz equation is solved with a new separation of variables (SVM) approach that allows one to calculate the ensemble-averaged single scattering optical properties of ensembles of randomly oriented particles analytically. Since the use of the SVM in spheroidal coordinates properly accounts for the geometry of the particles, the method is applicable to a large range of shapes ranging from elongated prolate needles via spheres to flat oblate disks. The relation between geometric symmetries of particles and symmetry relations of the electromagnetic scattering solution is investigated systematically in the general framework of the theory of point groups. The results are exploited in the model for increasing the computational efficiency. A comprehensive vector radiative transfer model is in part developed in this work. This radiative transfer model takes the output of the single scattering model as input and computes the Stokes vector components in a vertically inhomogeneous, plane parallel medium as a function of polar and azimuth angle and as a function of optical depth. The single scattering model is applied to investigate the impact of particle shape on the optical properties of size-shape distributions of randomly oriented particles, such as aerosol layers or ice clouds in the atmosphere. The optical properties are found to be much more sensitive to a variation in the effective aspect ratio than to a variation in the effective variance of a shape-distribution. The results of this study are used as input to the vector radiative transfer model in order to study the shape-sensitivity of the radiation field in a macroscopic medium containing a size-shape distribution of randomly oriented particles. It is found that both the radiance, and the degree of linear polarization, and the degree of circular polarization are strongly shape-sensitive in most viewing directions.
  • Ice -wedge networks and "whale-hole" ponds in frozen ground

    Plug, Lawrence J.; Hopkins, David M. (2000)
    The patterns of ice-wedge networks and of whale-hole ponds in frozen ground self-organize by strong interactions between pattern elements. Mechanisms for the consistent spacing (15--25 m) and orientation between ice wedges are examined in a model encapsulating the opening of fractures under a combination of thermally-induced tensile stress, stress reduction near open fractures, and heterogeneity of frozen ground and insulating snow. Modeled networks are similar to ice-wedge networks on the Espenberg coastal plain, Bering Land-Bridge National Park, Alaska, at the level of variation among Espenberg networks, as indicated by: (i) comparisons of distributions of relative orientation and spacing between wedges; and (ii) application of nonlinear spatial forecasting to modeled and Espenberg network patterns. Spacing in modeled networks is sensitive to fracture depth and weakly sensitive to thermally-induced tensile stress and substrate strength, consistent with the narrow range of spacing between natural ice wedges in different regions. In an extended model that includes recurring fractures over thousands of winters, networks similar to natural ice-wedge networks form. The annual pattern of fractures diverges from the ice-wedge pattern, with only ½--¾ of wedges fracturing in a single year at a steady-state reached after approximately 103 y. Short-lived sequences of extreme stress from cooling can permanently alter the spacing between and the fracture frequency of modeled ice wedges, suggesting that the existence and characteristics of existing and relic natural ice-wedge networks reflect extreme, not mean, climate conditions. Ponds on the Espenberg beach-ridge plain, approximately 2 m across and 1 m deep and surrounded by raised rings of ice-rich permafrost 2 m across and 0.5 m high, form through an interplay between localized bacterial decomposition of peat, thawing of frozen ground and frost heaving of peat in rings. Groups of hundreds of ponds at Espenberg assemble through time because new ponds are favored to form adjacent to raised rings around existing ponds. The nonlinear behavior that results from strong interactions in patterns of ice-wedge networks and in ponds suggests general limitations in the application of linear approaches to inferring the response of geomorphic systems to changes in forcing, such as climate change.
  • Predator-prey dynamics between mountain lions and mule deer: Effects on distribution, population regulation, habitat selection, and prey selection

    Pierce, Becky Miranda; Bowyer, R. T.; Bleich, V. C. (1999)
    Mountain lions (Puma concolor) and mule deer ( Odocoileus hemionus), which share a winter range in the Eastern Sierra Nevada in Round Valley, California, USA, were fitted with radio-telemetry collars and tracked to determine their movements and cause of mortality. The mountain lion population of Round Valley refers to a group of individuals that lived in close proximity to one another, essentially isolated from similar groups during the winter, and fed on the migratory herd of mule deer that overwinter in Round Valley. Mountain lions migrated seasonally with the deer population, and two distinct patterns for coping with variability in abundance of prey were observed. The unique migratory behavior identified for the mountain lions in this study indicates a more flexible social system for mountain lions than previously described. Tests of whether the presence of another mountain lion affected where individuals to killed deer indicated that social interactions had no effect and that social behavior was not regulating the population of mountain lions via spatial partitioning of prey. Examination of habitat selection by mule deer and mountain lions revealed that mule deer selected habitat at higher elevations (P < 0.001) with more bitterbrush ( Purshia tridentata) and less rabbitbrush (Chrysothamnus nauseosum ) than random locations. Mountain lions killed deer in relatively open areas with more desert peach (Prunus andersonii) than locations in which deer foraged. Those results indicated that deer were not confronted with a tradeoff in terms of habitat selection on the winter range because habitat with the best forage (e.g. bitterbrush), also provided the least predation risk. Comparisons of mule deer killed by mountain lions, coyotes, and automobiles indicated that mountain lions selected young (<1 year old) deer and both predators selected older age classes among adults. Furthermore, there was no selection by either predator for animals in poor condition. Among mountain lions in different social categories, female mountain lions with kittens selected more young deer than did other social categories. This study indicated that ambush predators (mountain lions) may be as selective for prey as coursing predators (coyotes) and that lactation in mountain lions may play a role in determining prey selection. ion.
  • Seismic investigations of subsurface volcanic structures and processes at Mount Spurr, Alaska and Soufriere Hills Volcano, Montserrat, West Indies

    Power, John A.; Wyss, Max (1998)
    Seismological techniques are used to infer the subsurface structures and volcanic processes at two recently active volcanoes: Mount Spurr, Alaska, and Soufriere Hills Volcano, Montserrat, West Indies. The three-dimensional P-wave velocity structure of Mount Spurr is determined to depths of 10 km by tomographic inversion of 3,754 P-wave arrival times from local earthquakes. Results show a prominent low-velocity zone beneath the southeast flank of Crater Peak extending from the surface to 3--4 km below sea level, spatially coincident with an active geothermal system. Beneath Crater Peak an approximately 3-km-wide zone of relatively low velocities correlates with a near vertical band of seismicity, suggestive of a magma conduit. No large low-velocity zone indicative of a magma chamber occurs within the upper 10 km of the crust. In the three years bracketing the 1992 eruptions of Mount Spurr's Crater Peak vent, approximately 2,500 located events were classified as Volcano-Tectonic (VT) earthquakes, Long-Period (LP) events, or Hybrid events. An unusual mix of VT, LP, and hybrid events at 20 to 40 km depth began coincident with the onset of unrest and peaked shortly after eruptive activity ended. The classified seismic events are combined with geophysical and geological data to develop a simplified model of the magmatic plumbing system of Mount Spurr. The major components of this model are a deep magma source zone at 20--40 km depth, a smaller storage zone at about 10 km depth, and a pipe-like conduit that extends to the surface. The frequency-magnitude distribution of earthquakes measured by the b-value is determined as a function of space beneath Soufriere Hills Volcano, from data recorded between August 1, 1995 and March 31, 1996. A volume of high b-values (b > 3.0) with a 1.5 Ian radius is imaged between 0 and 1.5 Ian beneath English's Crater and Chance's Peak. This anomaly extends southwest to Gage's Soufriere. At depths greater than 2.5 km, volumes of comparatively low b-values ( b <math> <f> ~</f> </math> 1) are found beneath St. George's Hill, Windy Hill, and below 2.5 kin to the south of English's Crater.
  • Cloud and surface properties and the solar radiation budget derived from satellite data over the Arctic Ocean: Comparisons with surface measurements and in situ aircraft data

    Xiong, Xiaozhen; Stamnes, Knut (2000)
    Use of satellite data to study the surface and cloud properties and the solar radiation budget (SRB) is very important for improving our understanding of cloud and sea-ice albedo feedback in the Arctic. Based on an accurate and comprehensive Radiative Transfer Model (RTM), algorithms were developed for using the National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR) data for the discrimination of cloud from snow/ice surfaces, retrieval of snow surface properties and surface albedo, and retrieval of cloud optical depth (tau) and effective droplet size ( re). Through the improved estimation of solar reflectance in AVHRR channel 3 (3.75 mum) and atmospheric anisotropic correction, a threshold function was found and used for developing an automatic cloud discrimination algorithm over snow/ice surfaces. Thin cirrus was discriminated using the brightness temperature difference between AVHRR channels 4 and 5 and brightness temperature in channel 4. Retrieval of snow grain size and mass-fraction of soot from AVHRR is difficult because of the effects of aerosol in channel 1 and the strong water vapor absorption in channel 2. Retrieval of surface albedo is more promising, but, with the melt of snow/ice, different narrow-to-broadband conversion relations should be used to derive broadband albedo. AVHRR channels 2, 3 and 4 are used to retrieve tau, r e and cloud top temperature simultaneously. Validation of these algorithms with in-situ aircraft measurements by the NCAR C-130 and the NASA ER-2 and with surface measurements obtained during the Surface Heat Budget of the Arctic Ocean (SHEBA) experiment indicates that the retrieved re is close to the "true" value of re, but the retrieved tau tends to be overestimated. Uncertainties of cloud retrievals with regard to cloud cover fraction, vertical inhomogeneity, multi-layer stratification and cloud phase were examined. Inter comparison of different satellite data demonstrates that NOAA-14 AVHRR data for SHEBA is overestimated by 10--20% using the calibration by Rao and Chen (1996). Finally, seasonal variation of surface albedo, cloud properties and SRB over SHEBA was derived based on 1 or 2 AVHRR overpasses per day from April to August, 1998.

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