RSS 1.0ScholarWorks@UA
ScholarWorks@UA is University of Alaska's institutional repository created to share research and works by UA faculty, students, and staff.
Communities in Scholarworks@UA
Select a community to browse its collections.
Recently Added
-
The effects of winter street treatment on Chester Creek Water Quality During Snow Melt EventsWater quality parameters for temperature, electrical conductivity, dissolved oxygen, pH, and turbidity and ion activity for calcium, chloride, and magnesium were measured during a period of five winters at eight locations along Chester Creek that flows from the Chugach Mountains east of the Municipality of Anchorage through the Municipality to the west into Knik Arm. The goal of the project was to identify the impact of meltwater on water quality due to common winter street treatments. Each year had its unique conditions. Melt events occurred when air temperature reached above freezing which were sometimes accompanied by rain events that enhanced snowmelt. Melt events throughout the season varied between four and nine with no considerable trend over the duration of the project. Maximum snowpack due to record snowfall occurred in winter 2022/2023 and 2023/2024. Electrical conductivity, which measured the total ion concentration in the water, and turbidity, which measured the concentration of particles, showed the major impact on water quality during melt events. Both parameters can be related to street treatments with salt/deicer and sand/gravel which are used on streets, parking lots, and walkways to reduce hazardous conditions, and both parameters generally increase from the east to the west as the creek runs through the Municipality. The highest electrical conductivity and turbidity were measured in the Middle Fork of Chester Creek at the Northern Lights location and directly in storm drainages at the Seward Highway location. The electrical conductivity correlated well with chloride concentration--a major compound of deicing agents and salts. This supports the assumption that the increase in electrical conductivity is due to street treatments. The total amount of ions, derived from electrical conductivity, is related to the area of each sub basin upstream from each sampling location, and indicates that the sub basin of the Seward Highway sampling location contributes fewer total ions to the creek per sub basin area than other sub basins. Comparing the measured values to water quality standards for aquatic life and propagation (18 AAC 70 Water Quality Standards, March 2020), the electrical conductivity should not exceed 1,500 µS/cm, and this value was only exceeded once on March 26, 2021 in the Middle Fork. Turbidity should not exceed background values by more than 10%. Background values for the sampling locations derived from times before freezing and in the absence of rain range from 0.7 to 5.17 NTU from east to west. Values measured during melt events and summer rain events frequently exceeded this water quality standard.
-
Teaching Spanish as a world language in Waldorf schools for grades one to eightWaldorf education provides a unique opportunity for students to fully experience their lessons in an integrative, artistic, and purposeful way, and this is certainly true for world language classes. Throughout a typical curriculum, various art forms are utilized along with physical movements and actions, allowing students to live through the lessons in an interesting and enjoyable way. At times, it becomes difficult to separate between songs, poems, skits, gestures, plays, or games, when all of these methods can be interwoven simultaneously. By integrating rhyme, repetition, gestures, music, movement, and visuals, classes become quite lively and interactive. It takes a lot of planning and preparation to teach this way, and Waldorf teachers typically juxtapose songs, poems, skits, plays, games, and activities that reinforce important topics, vocabulary, and themes throughout the year. In addition to memorizing material and delivering enthusiastic, heartfelt, and artistic lessons from memory, the teacher must gather all the various resources for a topic and decide on the best way to present them to the class. This project offers many of those connections for Spanish language lessons in a Waldorf setting, and it can also be altered and adapted for other world languages. Much of the foundational theory is common across different world languages, but it is helpful to find enough authentic and original material in the target language that has not been translated. Specific examples are given for Spanish language classes, as well as many commonly known stories that can be delivered in any language. Goals, activities, topics, skills, and milestones are suggested for each grade. This project provides the world language teacher with a solid outline or template for creating lessons in each grade, with enough material and references to start right away.
-
Factors affecting nest and brood survival of rock ptarmigan (Lagopus muta) in Interior AlaskaRock ptarmigan (Lagopus muta) are a circumpolar species endemic to high elevations and latitudes of North America and are common throughout Alaska. The r- selected life history of ptarmigan indicates that reproduction and specifically nest and brood survival is the most important component of population growth. However, factors affecting these population parameters have not been studied extensively or intensively, since there have only been three studies done in Alaska. Rock ptarmigan exhibit population fluctuations, which may be caused by changes in reproduction and survival due to predation and weather events. Warming climatic patterns and shifts in the range of their food resources may also be impacting rock ptarmigan populations. Previous research on rock ptarmigan in Alaska was completed five decades ago and methods of assessing their populations have improved. Therefore, a better understanding of factors affecting nest and brood survival is essential for understanding factors limiting population growth, particularly in a rapidly changing environment. In this study, we investigated whether variations in hen age, weather, timing of nest initiation, and nesting habitat affected nest and brood survival across two study sites. We focused this study on previously studied alpine populations of rock ptarmigan at Eagle Summit and Denali Highway sites in Interior Alaska from spring through summer in 2018 and 2019. Hens outfitted with transmitters were monitored weekly to determine the status of their nest or brood. We found canopy cover around the nest had the most effect on nest survival. Survival of nests with a closed canopy was more than five times higher than those with an open canopy at the Eagle Summit site and nearly two times higher at the Denali Highway site. Ptarmigan at Eagle Summit had higher brood survival than ptarmigan at the Denali Highway site. Our modeling indicated that survival of nests and broods was not affected by fluctuations in seasonal weather (e.g., minimum temperature and maximum precipitation). Establishing a basis for understanding temporal and spatial trends in population ecology is essential for effective management in a rapidly changing environment and these findings may improve the management of rock ptarmigan.
-
Toward multidisciplinary volcanic eruption models and forecasts in Alaska: contributions from automated seismic and acoustic signal detectionExplosive, ash-generating volcanic eruptions pose an increasing threat to a growing, globally connected population. Accurate forecasts of volcanic eruptions remain challenging due to the complexity of volcanic systems, but recent multidisciplinary synthesis efforts have proven effective. The National Science Foundation Prediction of and Resilience against Extreme Events (PREEVENTS) project aims to re-analyze and combine multidisciplinary observations at eight Alaska volcanoes to develop eruption forecast models. Leading the seismology and infrasound discipline, this dissertation details the development of automated tools capable of producing high-resolution catalogs of volcanic unrest signals from continuous seismic and acoustic data. By leveraging these catalogs and synthesizing insights from other disciplines, we re-examine past eruptions at select Alaska volcanoes and investigate their underlying mechanisms. Chapter 1 provides an overview of volcano monitoring in Alaska, and how different disciplinary insights converge to help us infer pre-, syn- and inter-eruptive processes. Chapter 2 presents an integrated workflow for improving volcanic earthquake catalogs. Using a combination of standard triggering, cross-correlation clustering, matched- filtering, and earthquake relocation methods, we recover previously undocumented seismic activity and refine interpretations of seismogenic zones at Redoubt and Augustine volcanoes. Chapter 3 introduces the Volcano Infrasound and Seismic Spectrogram Neural Network (VOISS-Net), a machine learning method for detecting and characterizing volcanic tremor and other transient signals. VOISS-Net provides a rapid and consistent means of classifying data in near real time and summarizing long-term data. Trained and applied on Pavlof Volcano, VOISS-Net reveals vent-specific seismic tremor profiles. Chapter 4 builds upon this idea of vent-specific unrest, integrating geodetic, petrologic, gas and thermal remote sensing data. We find that the summit and southeast flank vents at Pavlof Volcano exhibit contrasting eruption dynamics, which we attribute to differences in volatile content, magmatic ascent rate, and conduit geometry. Lastly, Chapter 5 concludes with a discussion of other relevant work and future research directions.
