• Applicability of the Walder-Hallet frost fracture model to laboratory cyclic uni- and bi-direction freeze-thaw of limestone and sandstone

      Haas, Abram; Peterson, Rorik; Kim, Sunwoo; Zhang, Lei (2021-08)
      Due to changing climate conditions, new geographic areas are being impacted by diurnal and seasonal freezing and thawing conditions. Many geologic materials in far north latitude areas, that had not undergone significant freeze and thaw previously, are now expected to experience those conditions more often. The bedrock in these northern regions is often used as the foundation for many buildings and other infrastructure, and so it is extremely important to understand the integrity of this material with the changing conditions. Walder and Hallet created a theoretical model to analyze the temperature of fine cracks within a rock when subjected to freezing conditions, and the growth of fine cracks due to thermally-induced water migration followed by freezing. More recently, Dr. Murton conducted multiple cyclic unidirectional and bidirectional freeze-thaw experiments in the laboratory that simulated active layer rocks both with and without permafrost below. These experiments measured temperature and pore pressure of the rock, and monitored the formation and growth of macroscopic (i.e. observable) cracks. Using Walder and Hallet's model as a starting point, I have created a numerical model to analyze the cyclic fluctuating temperature conditions used by Murton in his experimental work, but is not accounted for in the original Walder and Hallet model. I then compared his laboratory results with the numerical model predictions of temperature and location of observable crack growth. This required adjusting some model parameters used by Walder and Hallet to correspond with the experimental conditions and geological materials used. I found that the model predicts the correct location of maximum cracking, and the time of observable crack growth, for the unidirectional experiments. However, it predicted nearly the opposite of the laboratory results for the bidirectional experiments. To obtain these numerical results, I had to adjust parameters that attempt to describe the flow resistance within a fine-grained freezing rock material; a difficult and little understood phenomenon. Future work should focus on improving some of the original model assumptions that do not apply to most experimental situations including those of Murton. These include the angle of cracks, and the potential interaction between adjacent cracks. While the results of this numerical model did not predict all the observed results of Murton's experiments, it has shown what portions of the numerical model appear to work correctly, and what assumptions from the original theoretical model by Walder and Hallet need to be adjusted and improved.
    • Application of probabilistic decline curve analysis to unconventional reservoirs

      Egbe, Uchenna C.; Awoleke, Obadare; Goddard, Scott; Ahmadi, Mohabbat (2022-05)
      This work presents the various probabilistic methodology for forecasting petroleum production in shale reservoirs. Two statistical methods are investigated, Bayesian and frequentist, combined with various decline curve deterministic models. A robust analysis of well-completion properties and how they affect the production forecast is carried out. Lastly, a look into the uncertainties introduced by the statistical methods and the decline curve models are investigated to discover any correlation and plays that otherwise would not be apparent. We investigated two Bayesian methods - Absolute Bayesian Computation (ABC) and GIBBS sampler - and two frequentist methods - Conventional Bootstrap (BS) and Modified Bootstrap (MBS). We combined these statistical methods with five empirical models - Arps, Duong, Power Law Model (PLE), Logistic Growth Model (LGA), and Stretched Exponential Decline Model (SEPD) - and an analytical Jacobi 2 theta model. This allowed us to make a robust comparison of all these approaches on various unconventional plays across the United States, including Permian, Marcellus, Eagle Ford, Haynesville, Barnett, and Bakken shale, to get detailed insight on how to forecast production with minimal prediction errors effectively. Analysis was carried out on a total of 1800 wells with varying production history data lengths ranging from 12 to 60 months on a 12-month increment and a total production length of 96 months. We developed a novel approach for developing and integrating informative model parameter priors into the Bayesian statistical methods. Previous work assumed a uniform distribution for model parameter priors, which was inaccurate and negatively impacted forecasting performance. Our results show the significant superior performance of the Bayesian methods, most notably at early hindcast size (12 to 24 months production history). Furthermore, we discovered that production history length was the most critical factor in production forecasting that leveled the performance of all probabilistic methods regardless of the decline curve model or statistical methodology implemented. The novelty of this work relies on the development of informative priors for the Bayesian methodologies and the robust combination of statistical methods and model combination studied on a wide variety of shale plays. In addition, the whole methodology was automated in a programming language and can be easily reproduced and used to make production forecasts accurately.
    • Application of vortex tubes in an underground mine ventilation system

      Dumakor-Dupey, Nelson K.; Arya, Sampurna N.; Ghosh, Tathagata; Chen, Gang (2021-12)
      A major challenge for deep underground mines in tropical regions is high-temperature climate conditions at a working face. The high-temperature conditions can cause discomfort to people working underground and lead to health and safety issues. In some instances, airflow from primary ventilation and central refrigeration systems is not adequate to reduce the ambient temperature below a permissible limit at remotely located working faces. In some mines, mobile cooling systems are used in conjunction with an existing central cooling system. However, mining companies are often skeptical about implementing the combined cooling system due to its high operating costs involved with refrigeration infrastructure. This research examines the potential of a low-cost, maintenance-free vortex tube spot cooling system that operates on compressed air and can work with or without a central cooling system. Using an underground metal mine in Ghana as a case study, the impact of a vortex tube cooling system at a working face was evaluated using the computational fluid dynamics (CFD) technique. An integrated CFD model of vortex tube, ventilation duct, and development heading was developed. The airflow was simulated within the CFD model with a varying number of vortex tubes and locations. The simulation result shows that the mine can achieve a decent temperature drop from 28°C (82.4°F) to 24°C (75.2°F) with 20 vortex tubes at the working face.
    • Applications of stable isotope analysis to advancing the understanding of brown bear dietary ecology

      Rogers, Matthew C.; Barnes, Brian; Welker, Jeffrey; Brinkman, Todd; Gustine, David; Hilderbrand, Grant (2021-08)
      Dietary ecology is one of the most important drivers of brown bear fitness at the individual and population levels. However, researchers do not have an in-depth understanding of the trophic niche breadth, diet composition, and seasonal diet variation for most Alaskan populations. I set out to better understand multiple facets of brown bear dietary ecology using stable isotope analysis (¹³C & ¹⁵N) as the primary tool to infer brown bear diet and gain insights into their trophic niche, dietary seasonality, dietary generalism and specialism, and isotopic trophic discrimination factors. I determined that using sectioned hair samples is the best practice for determining the isotopic trophic niche of brown bears. Additionally, I determined amino acid trophic discrimination factors for brown bears and explored the ability to separate salmon species in bear diets. I also used stable isotope mixing models with sectioned hair samples to infer seasonal dietary patterns of individual bears in five distinct Alaskan ecosystems. Approximately one-quarter of bears relied solely on vegetation over multiple years despite access to other sources of nutrition; these bears could be considered specialists. Other bears, approximately half, switched diets seasonally but had the same pattern of resource use year over year, a foraging class that I termed persistent seasonal generalism. Approximately one-quarter of bears did not have a persistent dietary pattern across years and could be considered true generalists. Most bears appear to have preferred dietary patterns that are persistent through time, which may be indicative of foraging inertia; maintaining foraging patterns even when faced with changing resource availability due to natural fluctuations, disturbance, or climate change. The sum of this work advances our understanding of brown bear dietary ecology from the individual seasonal level to population level degrees of generalism and specialism, and the methods developed can be applied to many species for which dietary ecology information is difficult to obtain.
    • Assessing adverse effects of mercury in two pinniped species

      Lian, Marianne; O'Hara, Todd M.; Rea, Lorrie D.; Kuhn, Thomas B.; Van Wijngaarden, Edwin (2020-08)
      This dissertation studies measures of adverse effects in free-ranging pinnipeds associated with relatively high total mercury ([THg]) or monomethylmercury ([MeHg+]) concentrations, relatively low total selenium ([TSe]) concentrations and/or low TSe:THg molar ratios. Both the Steller sea lion (SSL, Eumetopias jubatus) and Pacific harbor seal (HS, Phoca vitulina richardii) inhabit coasts of the North Pacific, and are considered important sentinel species for One Health (environmental, animal and human health). Relatively high [THg] is reported for some animals in both species, causing concern for adverse effects especially in the developing fetus. Maternal piscivorous diet can expose the fetus to MeHg⁺ at a vulnerable developmental stage, with potential for adverse effects on several organ systems. This dissertation focused on two of these: nervous system development and function and oxidant/antioxidant homeostasis. In Chapter 2 I outlined capture and field anesthesia of free-ranging SSL. I found faster induction times for sevoflurane over isoflurane, with a significant interaction for anesthetist. Difference among the two agents is most likely attributed to the different chemical properties for these gases (blood solubility), whereas personal experience/comfort level most likely explains the differences between the human operators. Severe hypothermia was also documented, associated with the time of year, sex and duration of anesthetic event. There was an overall low mortality rate, and the protocols were effective for relatively safe field anesthesia of a large mammal. Chapter 3 assessed oxidant/antioxidant status and associations with [THg], [MeHg⁺], [TSe] and TSe:THg molar ratio in anesthetized free-ranging SSL pups. The anesthesia protocols described in Chapter 2 were used as a physiological stressor for measuring oxidative stress in SSL. Pinnipeds as diving mammals are naturally adapted with high antioxidant activity to survive long breath-holds during foraging. However, the relatively high [THg] found in some SSL cause concern for sequestration of Se due to its high binding affinity to Hg, and subsequently decreased antioxidant capacity (Se-dependent glutathione peroxidase (GPx)). I found a significant negative relationship between lipid peroxidation and [TSe], suggesting the potential for decreased antioxidant protection from Se. There were also significant associations between increased GPx activity and lipid peroxidation, possibly protecting pups with relatively high [THg] and low TSe:THg molar ratios. In Chapter 4 I repeatedly evaluated live-stranded HS pups admitted to The Marine Mammal Center, using weekly clinical and behavior assessments, which were analyzed for associations with [THg]. There was a significant association between [THg] in hair and/or blood and decreased response to tactile stimulation, less movement and longer stays in rehabilitation. These findings will help us better assess similar [THg] in hair and blood of SSL in Alaska that we currently study as well as other pinnipeds. In summary, this dissertation confirms the potential for adverse effects in two free-ranging species of pinnipeds exposed to MeHg⁺ in utero.
    • Assessing the demographic and genetic contributions of precocial males in a naturally spawning population of coho salmon

      King, Erika M.; McPhee, Megan; Tallmon, David; Vulstek, Scott; Cunningham, Curry (2022-05)
      Despite the importance of alternative life history strategies to population productivity, little is known about the mating structure of precocial ('jack') males in Pacific salmon. The number of successful matings obtained by jacks in the wild is not well characterized and the impact of including or excluding jacks in the management of Pacific salmon populations is unknown. This study aims to fill knowledge gaps in the understanding of jack life history by 1) determining the typical contribution of jacks to the next generation in a natural mating population; and 2) estimating the impact of jacks on genetic diversity. The study capitalizes upon 11 years of demographic and genetic data from a naturally spawning population of Coho Salmon from Auke Creek, in Juneau, Alaska. Individuals returning over this time period (~8,000 individuals) were genotyped at ~250 single-nucleotide polymorphism (SNP) loci. Using these genotypes, we quantified the adult-to-adult reproductive success of different male types using parentage analysis for each of seven return years and compared genetic and demographic estimates of effective population size. We demonstrated that although jacks were less successful than full-size males on a per individual basis, they contributed substantially to the population and influenced population and evolutionary dynamics.
    • Assessing the long-term growth response and age estimation precision for Arctic whitefishes in a rapidly changing nearshore environment

      Gatt, Kyle P.; Sutton, Trent M.; von Biela, Vanessa R.; McPhee, Megan V. (2021-05)
      Accurate monitoring of population-level health and productivity is essential for assessing the status and availability of subsistence harvested species at the forefront of climate change. This study used otolith biochronology to assess the long-term growth response of Arctic Cisco Coregonus autumnalis during a period of rapid environmental change in the Beaufort Sea region and to identify drivers of growth. A biochronology spanning 22 years (1996-2018) revealed significant interannual variation, with faster growth rates in years with warmer (R² = 0.31) and more saline (R² = 0.47) waters during the ice-free summer feeding period (July-September). These results suggested that warming may benefit Arctic Cisco. This study also compared age estimates made using fin rays, scales, and otoliths of four subsistence whitefishes (Arctic Cisco, Least Cisco Coregonus sardinella, Broad Whitefish Coregonus nasus, and Humpback Whitefish Coregonus pidschian) from the Beaufort Sea to compare the aging precision of non-lethal structures (fin rays and scales) to otoliths. Fin rays and scales provided similar age estimates as otoliths until the age of sexual maturity and underestimated otolith age for mature individuals. Scales underestimated age more often and were more difficult to which to assign age than the other two structures. Among Arctic Cisco in Alaska, fin rays and scales provided similar age estimates as otoliths for all age and size classes examined because most individuals in the study area were immature fish. These results suggested that dorsal fin rays may be used to estimate age in Least Cisco <300 mm, Broad Whitefish <450 mm, and Humpback Whitefish <350 mm, and that otoliths should remain the primary aging structure for the largest whitefishes. Overall, this research complements existing monitoring by providing evidence of an Arctic subsistence species that may benefit in part from warming and highlights non-lethal alternatives for monitoring the age structure of juvenile whitefishes.
    • At the edge of somewhere: journeying on the Dalton Highway

      Wheeler, Charlotte A.; Farmer, Daryl; Holt, Joseph; Ehrlander, Mary (2022-05)
      Some journeys need to be made. In At the Edge of Somewhere, the writer embarks on a cycle ride from Fairbanks to Prudhoe Bay on Alaska's remote and dangerous Dalton Highway. Drawn obsessively to the Arctic sea ice some years earlier and, now, onto "the road," her journey attempts to bring closure to the long-standing need to be on the move, at once not able or even wanting to settle but also seeking a place within herself, and therefore a physical location, she might call home. She travels with a found notebook, acquired unexpectedly at the start of her ride, which reveals the heart-wrenching story of Samuel Morgan. As she journeys through boreal forest, high alpine and tundra, we learn not only of Samuel's abandonment to boarding school as a young boy but of the writer's traumatic childhood. Painful memories, reminiscences of working on "the road" and new encounters blend with Samuel's search for peace amid an encounter with the artistic works of an 18th century German Romantic painter. Touching on themes of trauma, art, and their relationships with the landscape, both the writer and Samuel reach Prudhoe Bay and the Arctic Ocean ready to let go of their pasts.
    • Atmospheric modeling of natural hazards

      Hirtl, Marcus; Stuefer, Martin; Webley, Peter; Simpson, William; Grell, Georg (2021-05)
      Airborne hazards either in gaseous form or particulate matter can originate from a variety of sources. The most common natural airborne hazards are ash and SO₂ released during volcanic eruptions, smoke emitted caused by wildfires and dust storms. Once released into the atmosphere they can have a significant impact on different parts of the environment e.g. air quality, soil and water, as well as air traffic and ground transportation networks. This latter field is an important aspect of everyday life that is affected during hazardous events. Aviation is one of the most critical ways of transport in this century. Even short interruptions in flight schedules can lead to major economic damages. Volcanic eruptions comprise one of the most important airborne hazards to aviation. These are considered rare as compared to severe weather, but with an extremely high impact. This dissertation focusses on dispersion modeling tools and how they can support emergency response during different phases of volcanic eruption events. The impact of the volcanic ash cloud on the prediction of meteorological parameters and furthermore the dispersion of the ash is demonstrated by applying the Weather Research Forecasting (WRF) model with on-line integrated chemical transport (WRF-Chem) to simulate the 2010 Eyjafjallajökull eruption in Iceland. Comprehensive observational data sets have been collected to evaluate the model and to show the added value of integrating direct-feedback processes into the simulations. The case of the Eyjafjallajökull eruption showed the necessity to further develop the volcanic emission preprocessor of WRF-Chem which has been extended for flexible and complex ash and SO₂ source terms. Furthermore, the thesis describes how scientists could support operational centers to mitigate hazards during a large volcanic eruption event. The author of the dissertation coordinated a large exercise including experts across all Europe within a project funded by the European Union. The exercise aimed to develop and test new tools, models, and data to support real-time decision making in aviation flight planning during a volcanic crisis event. New state-of-the-art modeling applications were integrated into a flight planning software during a fictitious eruption of the Etna volcano in Italy with contributions from scientists, the military and the aviation community.
    • Barriers to completing degrees for UAF Ph.D. students

      Whitaker, Hannah L.; Gifford, Valerie; Renes, Susan; Carr, Kiana (2021-12)
      A student faces several challenges when working towards a doctoral degree. Previous research has demonstrated that discrimination, lack of support, poor mentorship, funding issues, mental health concerns, and minority stress are barriers to degree completion. The available research also suggests that these difficulties are especially challenging for underrepresented students. Although universities are currently attempting to mitigate certain of these barriers, more can be done to understand the doctoral experience as a way of supporting students. Focus groups were conducted for this thesis to explore the barriers, strengths, and advice for others that doctoral students have at the University of Alaska Fairbanks. Key findings of this study included racism, discrimination, and funding as the primary barriers to degree engagement and completion. The results also suggested the importance of effective mentorship and community support for doctoral students. Implications for students, staff and faculty, and universities are discussed. This information is important in creating a more productive and inclusive environment for doctoral students at UAF.
    • Beyond trending: using risking connection as a framework for moving agency culture toward trauma-informed care

      Healey, Michael J.; Renes, Susan L.; Strange, Anthony; Baker, Courtney; Anahita, Sine (2020-08)
      The prevalence and pervasive impact of adverse childhood experiences (ACEs), and more broadly, trauma, are well supported in the extant literature. Despite this evidence, there remains a significant dearth of formal training and educational programs that prepare staff who work with trauma survivors within complex behavioral health systems. Trauma-informed care (TIC) has moved beyond a trend in the mental health field and is gaining momentum as a leading philosophical paradigm that is being infused as an operational framework for agencies that work with survivors. Risking Connection (RC) is a curriculum-based training program that works with agencies interested in becoming trauma-informed. The current study examined the impact of RC on trainee outcomes for knowledge gain, attitude change, and vicarious trauma (VT) on 119 participants who all work for a therapeutic group home system being operated by a provincial government in Atlantic Canada. The findings in this study suggest that RC is effective in improving knowledge gain and attitude change in a favorable direction toward TIC. The study also supported previous findings associated with the improvement of VT.
    • Blood falls, Taylor Glacier, Antarctica: subglacially-sourced outflow at the surface of a cold polar glacier as recorded by time-lapse photography, seismic data, and historical observations

      Carr, Chris G.; Pettit, Erin; Carmichael, Joshua; Truffer, Martin; Tape, Carl (2021-05)
      Blood Falls forms when iron-rich, hypersaline, subglacially-sourced brine flows from a crack in the surface of Taylor Glacier, Antarctica. If air temperatures are low enough, the brine freezes to form a fan-shaped icing deposit. In chapter two, historical observations (including photos, oral histories, written descriptions, and field sketches) are evaluated using a confidence assessment framework to compile a history of brine icing deposit presence or absence during summer field seasons between 1903-1904 and 1993-1994. Additionally, an alternative explanation for a small, localized advance of a portion of the terminus is proposed: rather than temperature-driven ice viscosity changes, rising lake level drove temporary, localized basal sliding which induced advance, thinning, and collapse of a part of the terminus previously grounded on a proglacial moraine. In chapter three, time-lapse imagery is used to document a 2014 wintertime brine release that occurred in the absence of surface melt. This suggests that meltwater-driven fracture propagation of surface crevasses downward into the glacier was not a likely factor in this brine release event, as has been previously proposed. Further, there is no evidence for an increase in Rayleigh-wave activity prior to or during the brine release that would be characteristic of shallow seismic sources. Together, this suggests that sufficient pressure is built in the subglacial system to trigger basal crevassing and fracture propagation upward to allow brine release at the surface. In chapter four, two different seismic detectors that use ratios of short-term to long-term seismic energy variance to identify seismic events are compared. The detectors use different statistical distributions to determine what constitutes a large enough ratio to trigger an event detection. Differences between what the two detectors identify as events rather than background noise are interpreted as environmental microseismicity with a distinct diurnal and seasonal occurrence. Minimum detectable event sizes over 3-day time windows are compared. Together, these studies provide context for the history of brine release events, wintertime brine release characteristics, and descriptions of the local seismic environment at Taylor Glacier.
    • Born to burn: characterizing fuel loads, flammability and plant traits across spatio-temporal gradients of black spruce dominated communities

      Grzesik, Emilia J.; Ruess, Roger; Hollingsworth, Teresa; Turetsky, Merritt (2020-12)
      The flammability of black spruce forests is influenced by the fuel loadings and quality of fuels within a site, whereas the ability of a site to self-replace after fire, and thus forest resiliency, depends on the fire-ecological trait attributes of the plant community. Black spruce plant communities have been undergoing self-replacement succession from low to moderate severity fires for thousands of years, however, recent intensification of interior Alaska's fire regime is leading to shifts in post-fire successional trajectories, resulting in many ecological implications. This study focuses on understanding the variation in black spruce forest flammability, based on fuel load quantity and quality, and fire-ecological plant traits in 28 black spruce dominated sites ranging across age and moisture gradients in interior Alaska. I quantified tree canopy, understory and below-ground fuel loads, developed models to predict fuel loads and then utilized my measurements of above-ground fuel load quantity and quality to calculate a site-level flammability index. Based on my analyses, significantly greater flammability indices, and thus burning potential, occur in sites greater than 34 years in age, at elevations greater than 302 m and with dry site moisture, which are representative of dry, nonacidic upland black spruce and dry, acidic upland black spruce-lichen forest ecosystems. Furthermore, although fire-ecological plant trait attributes of Hylocomium splendens and Vaccinium uliginosum vary with age and moisture gradients, the amount of intra-specific trait variation within a site could not be explained by stand age or moisture and thus forest resiliency is also likely independent of age and moisture gradients. Further research is necessary to explore both abiotic and biotic explanatory variables related to intra-specific plant trait variation to better understand variation in black spruce forest resiliency on the landscape. The results from this study can assist fire managers in the prediction of black spruce forest burning potential and its vulnerability to ecosystem shift post-fire.
    • Bridging expert knowledge and fisheries data to inform assessment and management of rockfishes in the Gulf of Alaska

      Gordon, Jesse; Beaudrau, Anne; Carothers, Courtney; Williams, Benjamin (2021-08)
      Over the past few decades, nearshore rockfishes (Sebastes spp.) have experienced increased pressure from multiple fisheries throughout the Gulf of Alaska. The unique life history traits of rockfishes pose a host of challenges that make them difficult to monitor and vulnerable to overfishing. Rockfishes are economically and culturally important to coastal communities in the Gulf of Alaska. Therefore, the inclusion of fishers' knowledge in rockfish assessment and management will help to address biological goals and meet the needs of a growing fishery. This thesis examines the recent history and current management issues in nearshore rockfish fisheries in the Gulf of Alaska through triangulation of expert knowledge, fishery data, and biological surveys. We conducted semi-structured interviews with 43 fishers and agency staff who have long-term knowledge of and experience in rockfish fisheries within the Sitka and Kodiak areas. Chapter One presents a synthesis of changes in commercial and recreational rockfish fisheries since the 1970s, based on datasets from the Alaska Department of Fish and Game (ADF&G) and expert knowledge from interviews. Harvest data indicated both increases and decreases in nearshore fishing effort and harvest patterns, depending on the fishery sector, region, and rockfish species. Fishers and agency staff offered a longer-term and contextual understanding of changes in rockfish abundance. Most experts observed an overall decline in pelagic rockfishes near Sitka, AK and more variable patterns of abundance near Kodiak, AK. While many experts were hopeful about future sustainability of rockfish fisheries, others expressed concern about increases in localized fishing pressure, growth of charter fishing, barriers to access in some fisheries, and declines in rockfish biomass. Chapter Two identified institutional pathways and gaps in public engagement with rockfish fisheries management in Alaska. Fishers and agency staff highlighted the value of formal and informal institutions for effective engagement and emphasized the importance of relationship building and trust between fishers and agency staff. Fishers demonstrated stewardship over their fisheries through participation in local to state management processes, establishing norms of sustainability within fishing associations, and by taking personal actions to promote fishery conservation. Experts identified institutional gaps which included transparency issues regarding regulations, underrepresentation of recreational and subsistence harvesters in the Board of Fisheries public process, and communication barriers between the sport and commercial divisions of ADF&G. Our findings highlight the challenges of bringing together disparate data sources and the benefits of including multiple ways of knowing to produce a more complete understanding of dynamic fishery systems.
    • Bristol Bay dual permit operations, vessel heterogeneity, and the migration of Alaskan permit holders

      Gho, Marcus J.; Criddle, Keith; Adkison, Milo; Adkison, Milo; Twomley, Bruce; Brown, Benjamin (2020-08)
      This dissertation examines three aspects of Alaska's Limited Entry program. Chapter 1 explores the outcome of dual-permit regulations. The Alaska Board of Fisheries passed regulations allowing for dual permit operations in the Bristol Bay Pacific salmon drift gillnet fishery starting in 2004. These regulations allow two permit holders to fish from a single vessel with additional gear. Policymakers anticipated that the dual permit regulations would encourage young fishermen to enter the fishery and reduce the number of limited entry permits transferred from local fishermen to nonlocal fishermen and nonresidents. Statistical analyses reported in Chapter 1 indicate that the dual-permit program successfully offset part of the adverse influence of increases in the market value of permits on the number of new entrants and that implementation of dual-permit regulations was followed by a reduction in the median age of new entrants, particularly among nonresidents. However, the implementation of dual-permit regulation failed to staunch the outflow of limited entry permits. Chapter 2 examines the persistence of heterogeneity in the size of fishing vessels active in the Bristol Bay salmon drift gillnet fishery. When entry was limited, the commercial fishing fleet included a mix of vessels up to the long-established 32-foot maximum length. The race for fish that so often arises under license limitation favors the adoption of vessel and gear configurations that maximize catch-perday and could be anticipated to lead to increased homogeneity in fleet composition. Yet, statistical analyses indicate that even after over four decades, the composition of this fleet remains heterogeneous in vessel size and vessel value. Multivariate analysis of time series observations of vessel values indicates that vessels captained by permit holders who were given their permit are less capitalized than vessels captained by permit holders who purchased their permit. Likewise, vessels operated by local resident permit holders are less capitalized than vessels owned by nonlocal Alaskan or nonresident permit holders. In addition, vessels operated by older permit holders are less capitalized than vessels operated by younger permit holders. Chapter 3 examines the factors that influence the migration of permit holders. Since limitation, there have been concerns that ever more of the permits issued to individuals local to Alaska's fisheries would come to be held by individuals who were not local to the fisheries. The count of permit holders local to a fishery can change because of transfers, administrative cancellations, or because permit holders migrate either to or from fisheries where the permit is used. Chapter 3 considers possible factors that predict permit migration to or from different residency classes. Included in our analysis was a look at season length, fleet participation rates, permit transfers, the size of the fleet, gear type, wages of construction workers to serve as a proxy for substitute employment, and the local unemployment rate. Statistical analyses indicate that fisheries with longer seasons show slightly elevated migration from local to nonresident status of permit holders. Permit latency and permit holder migration have a negative relationship among the significant variables. Transfers serve as a substitute for permit migrations and provide the largest influence on permit migrations. For every resident type of migration, as the transfer rate increases, fewer permit holders migrate. The total number of permits within the fishery also affects the migration of permit holders, albeit only minimally. The second-largest influence on permit migration is gear type. Migrations to local setnet permit holders had a smaller magnitude of change than migrations from permit holders across most categories. Generally speaking, migration tends to move towards a nonresident status of permit holders. Wages of construction workers were only significant at the 5% level for transfers from locals to nonresidents and from nonresidents to locals, but both variables were positive. As the local unemployment rate increases, the rate of locals emigrating outside of Alaska increased.
    • Broad whitefish (Coregonus nasus) ecology and habitat use in Arctic Alaska: spawning habitat suitability, isotopic niches, life-history variations, and climate change risks to subsistence fisheries

      Leppi, Jason C.; Wipfli, Mark S.; Rinella, Daniel J.; Seitz, Andrew C.; Falke, Jeffrey A. (2021-08)
      Broad Whitefish (Coregonus nasus) is a critically important subsistence species for Alaska's Indigenous communities, yet little is known about the basic ecology of this species at the individual level. Understanding habitat use by Broad Whitefish is challenging due to their mobility and our limited ability to track fish throughout their lives as they move among a suite of habitats that are spatially dispersed, change over time, and are often temporary. The Arctic is undergoing major landscape and ecosystem transformation from climate change and oil and gas development, which may threaten Arctic ecosystems used by Broad Whitefish. This dissertation presents new information on the ecology of Broad Whitefish captured in the Colville River, Alaska. In Chapter 1, an intrinsic potential (IP) model for Broad Whitefish was used to estimate the potential of streams across the watershed to provide spawning habitat. Results were compared with movement patterns of radio-tagged prespawn Broad Whitefish. In Chapter 2, ecological niches utilized by Broad Whitefish were investigated via stable isotope analyses of muscle and liver tissue and otoliths from mature fish. In Chapter 3, strontium isotope (⁸⁷Sr/⁸⁶Sr, ⁸⁸Sr) otolith chronologies across individuals' lives were used to quantify life-history attributes and reconstruct migration patterns of fish. Finally, in Chapter 4, the current understanding of ongoing and future changes to the habitat, productivity, and behavior of Broad Whitefish were summarized to assess risks facing Arctic freshwater ecosystems and fishes more broadly. IP model results showed the majority of habitat with high IP (≥ 0.6) was located within the braided sections of the main channel, which encompassed > 1,548 km, and starting in mid-July, prespawn fish used habitats in the middle and lower watershed. Stable isotope analysis revealed a range of [delt]¹³C (-31.8- -21.9‰) and [delta]¹⁵N (6.6- 13.1‰) across tissue types and among individuals. Cluster analysis of muscle tissue δ¹³Cˈ, δ¹⁵N, δ¹⁸O, and δD indicated that Broad Whitefish occupied four different foraging niches that relied on marine-and land-based (i.e., freshwater and terrestrial) food sources to varying degrees across the summer period. Strontium isotopes revealed six main life histories, including three anadromous types (59%), one semi-anadromous type (28%), and two nonanadromous types (13%), suggesting greater complexity in life-history types than previously documented. Climate change is expected to continue to alter Arctic hydrology and, therefore, suitability, connectivity, and availability of habitats critical for Broad Whitefish population persistence. Warming and lengthening of the growing season will likely increase fish growth rates; however, the exceedance of threshold stream temperatures will likely increase physiological stress and alter life histories, which is likely to have mixed effects on Arctic subsistence fishes and fisheries. This information on Broad Whitefish spawning intrinsic potential, foraging niches, and life histories provides crucial knowledge to understand critical habitats used across time and space, which will help managers and conservation planners better understand the risks of anthropogenic impacts, such as climate change and oil and gas development, and help conserve this vital subsistence resource.
    • Brooks Range perennial snowfields : mapping and modeling change in Alaska's cryosphere

      Tedesche, Molly E.; Barnes, David L.; Fassnacht, Steven R.; Trochim, Erin D.; Wolken, Gabriel J. (2021-08)
      Perennial snowfields, such as those found in the Brooks Range of Alaska, are a critical component of the cryosphere. They serve as habitat for an array of wildlife, some of which are crucial for rural subsistence hunters. Snowfields also influence hydrology, vegetation, permafrost, and have the potential to preserve valuable archaeological artifacts. In this study, perennial snowfield extents in the Brooks Range are derived from satellite remote sensing, field acquired data, and snowmelt modeling. The remote sensing data are used to map and quantify snow cover area changes across multiple temporal scales, spatial resolutions, and geographic sub-domains. Perennial snowfield classification techniques were developed using optical multi-spectral imagery from NASA Landsat and European Space Agency Sentinel-2 satellites. A Synthetic Aperture Radar change detection algorithm was also developed to quantify snow cover area using Sentinel-1 data. Results of the remote sensing analyses were compared to helicopter and manually collected field data. Also, a snowfield melt model was developed using an adaptation of the temperature index method to determine probability of melt via binary logistic regression in two dimensions. The logistic temperature melt model considers summer season snow cover area changes per pixel in remotely sensed products and relationships to several independent variables, including elevation-lapse-adjusted air temperature and terrain-adjusted solar radiation. Evaluations of the Synthetic Aperture Radar change detection algorithm via comparison with results from optical imagery analysis, as well as via comparison with field acquired data, indicate that the radar algorithm performs best in small, focused geographic sub-domains. The multi-spectral approach appears to perform similarly well within multiple geographic domain sizes. This may be the result of synthetic aperture radar algorithm dependency on backscatter thresholding techniques and slope corrections in mountainous complex topography. Results indicate that perennial snowfield extents in the Brooks Range are decreasing over decadal time scales, with short-lived, interannual and seasonal increases. Results also show that perennial snowfields are more persistent at higher elevations over time with notable consistency in at least one of the Brooks Range sub-domains of this study, Gates of the Arctic National Park and Preserve. Climate change may be altering the distribution, elevation, melt behavior, and overall extents of the Brooks Range perennial snowfields. Such changes could have significant implications for hydrology, wildlife, vegetation, and subsistence hunting in rural Alaska.
    • Carbon dioxide enhanced oil recovery and sequestration in the Orion Oil Field in the North Slope region of Alaska

      Dogah, Banabas D.; Ahmadi, Mohabbat; Atashbari, Vahid; Awoleke, Obadare (2021-12)
      Carbon dioxide flooding in viscous oil systems has been proven to improve oil recovery and store CO₂ in several geologic basins worldwide. With global energy steadily transitioning towards decarbonization, CO₂-EOR and Sequestration can reduce the carbon footprint from crude oil production. Although well accepted globally, the potential of improved oil recovery and CO₂ storage capacity has not been extensively studied in Alaska. Since the CO₂ injection process involves phase transition, reservoir simulation becomes more complex. It requires reliable techniques to estimate the ultimate recovery factor, oil production rate, and CO₂ storage volumes precisely. This study focuses on carbon dioxide enhanced oil recovery (CO₂-EOR) and storage in the Orion satellite field of Alaska, its ability to reduce greenhouse gases, and the technical and economic feasibility of a CO₂ flooding project. In this study, the Peng-Robinson equation of state is tuned to model fluid behavior from the respective sands accurately. Core flooding results from the Orion Oil Pool in the Schrader Bluff Formation provided the basis for developing relative permeability curves for the various layers in the geological model. The geological model was then coupled with the developed fluid model and introduced into a compositional simulator capable of handling the heterogeneous complexity to simulate CO₂ injection. Simulations suggested that the CO₂ gas injection is partially miscible in the Orion reservoir at pressures close to the average initial reservoir pressure. Consequently, CO₂ mixes with oil in the reservoir, reduces oil viscosity, increases oil mobility, and improves oil recovery. Different simulation scenarios were considered and compared, including the effects of fluid injection mixtures on oil recovery, well trajectory effects, and production bottom hole pressure effects on oil recovery. A considerable volume of injected CO₂ is expected to be sequestered in the reservoir, for which economic analysis is conducted for tax credit purposes. The results show that 40% Enriched CO₂ injection achieved the highest oil recovery, which highlights the importance of selecting the appropriate injector and producer well trajectory. This work provides insights into the optimum CO₂ gas flooding controlling parameters for incremental oil production through sensitivity analysis. The study's novelty is further expanded by quantifying the potential of CO₂ sequestration in each layer of the Orion oil field.
    • The catalyst for contemporary jihad: the religious leaders and their strategies

      DeWitt, Ronnie; Duke, Rob; Skya, Walter; Sine, Don; Botros, Maged; Boylan, Brandon (2021-08)
      This dissertation provides insight in the methodologies utilized by leaders of jihadist terrorist organizations who create a dedicated following in their pursuit of establishing a global caliphate. The research in this project illustrates a linkage from these charismatic leaders to the sacred edicts of the Koran, the Hadith, the Sunna, Sharia (Islamic jurisprudence), and the prophet Muhammad. Moreover, it bears out a unique perspective in academic national security studies which delves deeper than similar published works regarding subject matter focused on both violent and stealth jihad (also known as the non-violent usurpation of non-Islamic cultures). These subjects are discussed in detail with real-world examples that focus on the surreptitious use of political propaganda and sustaining influence, which are key ingredients necessary to recruit empathetic followers into doing the bidding of Islamic-based terrorist organizations. Without studying the psychological aspect that motivates potential terrorists it would be a daunting task to develop countermeasures in defeating this global threat. This dissertation also reviews key literature related to this concept. This investigative study bears out a perspective that uniquely differs from any previously published work in this discipline due to the author's professional experience outside of academic research. This will become clear in chapter seven which focuses upon the infamous Day of Terror trial in the Southern District of New York Federal Court in 1995. This episode, coupled with other evidence, will prove that jihadists have been striving to establish a global Islamist caliphate by utilizing terrorism and cultural usurpation.
    • Celebrating Alutiiq cultural revitalization: pathways to holistic individual health and community wellness

      Mete, Margaret Susan Draskovich; John, Theresa; Koskey, Michael; Counceller, April; Drabek, Alisha; Topkok, Sean Asiqłuq (2021-12)
      It is well understood that disease is a consequence of varied causation. Despite the fact that many health care providers acknowledge the importance of treating patients in a comprehensive manner in order to successfully cure sickness or alleviate symptoms, the contemporary medical system dispenses care in a fragmented and frequently incomplete manner. The essential differences between Indigenous epistemologies and the predominant Western worldview has had a more devastating impact on well-being and infirmity than is often recognized. The intention of this research is to explore the importance of promoting balanced holistic health care at a deeper and more essential level in order to address root causes, accessed through communication with the natural and spiritual realms, versus merely treating the physical expressions of illness.