Current state of Alaska's glaciers and evolution of Black Rapids Glacier constrained by observations and modeling

Thesis (Ph.D.) University of Alaska Fairbanks, 2016Glaciological studies rely on a wide range of input data, the most basic of which, accurate glacier extents, were not available on an Alaska wide scale prior to this work. We thus compiled a glacier database for Alaska and neighboring Canada using multi-sensor satellite data from 2000 to 2011. The inventory yielded a glacierized area of 86,720 km², which corresponds to ~12% of the global glacierized area outside the ice sheets. For each of the ~27,100 glaciers, we derived outlines and 51 variables, including centerline lengths, outline types, and debris cover, which provide key input for observational and modeling studies across Alaska. Expanding on this large-scale observational snapshot, we conducted two case studies on Black Rapids Glacier, Eastern Alaska Range, to assess its evolution during the late 20th and 21st centuries. Black Rapids Glacier, 250 km² in area, was chosen given its surge-type dynamics and proximity to critical infrastructure. Remotely sensed and in-situ elevation observations over the 1980--2001--2010 period indicated strong mass loss of Black Rapids Glacier (~0.5 m w.e. a⁻¹), with higher thinning rates over the 2001--2010 (~0.65 m w.e. a⁻¹) than the 1980--2001 period (~0.4 m w.e. a⁻¹). A coupled surface mass balance-glacier dynamics model, driven by reanalysis climate data, reproduced the glacier shrinkage. It identified the increasingly negative summer balances, a consequence of the warming atmosphere, as the main driver for the negative mass balance trend. Elevation observations in Black Rapids' surge reservoir suggested a surge was not imminent at the time of the analysis due to the lack of ice thickening. Re-initiation of sufficient elevation growth in the surge reservoir would require more favorable surface mass balances, as observed in the early 1980s. Compared to nearby Gulkana Glacier (a USGS benchmark glacier), the observed specific mass losses at Black Rapids Glacier were less pronounced, ~0.4 vs. 0.5 m w.e. a⁻¹ (1980--2001) and ~0.65 vs. 0.95 m w.e. a⁻¹ (2001--2010). The larger difference between the two glaciers' mass balances over the 2001--2010 period was partly caused by rockslide debris deposited on Black Rapids Glacier in 2002. This ~4.5 m thick debris layer, spread across 11.7 km² of Black Rapids lower ablation area, was modeled to suppress Black Rapids' glacier wide mass loss by ~20%. Modeling Black Rapids' evolution until 2100 suggested sustained glacier retreat, even under a repeated constant climate scenario, with ~225 km² of area remaining in 2100. Using a warming scenario (RCP 8.5), the modeled retreat was strongly accelerated with only ~50 km² of glacier area left in 2100. Given its thick, low-slope valley portion, Black Rapids Glacier is very susceptible to climate change. Its neighboring glaciers in the Eastern Alaska Range have similar properties, suggesting region wide glacier retreat in the future. To constrain this further, the Black Rapids case studies should be extended to the regional scale, a step now facilitated by the new Alaska wide glacier database.Chapter 1 General Introduction -- Chapter 2 Derivation and analysis of a complete modern-date glacier inventory for Alaska and northwest Canada -- Chapter 3 Geodetic mass balance of surge-type Black Rapids Glacier, Alaska, 1980--2001--2010, including role of rockslide deposition and earthquake displacement -- Chapter 4 Mass balance evolution of Black Rapids Glacier, Alaska, 1980--2015--2100, and its implications for surge recurrence -- Chapter 5 General Conclusions

Gaps in Indigenous Health Care

Indigenous people of the United States make up roughly 1.7% of the total population; this is including those of mixed race but still qualify for indigenous benefits. These 5.2 million individuals are dispersed across the nation and some live in rural and isolated locations where health care has not always been readily available. When the Indian Health Care Improvement Act of 1976 was implemented it meant that any indigenous person that met racial qualifications was financially covered if the care was provided by an indigenous health service or facility. Due to this act, health and wellness of indigenous people across the nation increased and statistics regarding mortality rate and death due to illness began to decline. Although this implementation proved to be beneficial for short term care, there are still gaps in the care offered to indigenous people and the resources that are still readily available in rural and isolated communities. This dissertation will be discussing the gaps in indigenous health care across the nation and how they have hindered the improvements made by the Indian Health Care Improvement Act of 1976. By analyzing literature and statistics that demonstrate health trends that correlate with the implementation of acts chronologically, it will analyze the need for improvements that are still a right of indigenous people for proper health care. It’s important to understand the significance of reparations and how it has aided and will continue to aid indigenous health care and their future wellbeing

Know Thyself: Churchmans Inquiring Systems and the Future of IT Enabled Knowledge Management

Inquiring systems, as presented by C. West Churchman (1971) possess the necessary scope by which to elucidate and facilitate the acceleration and advancement of organizational learning and change that is required within the field of knowledge management/ecology. This tutorial provides a readily accessible means by which to expedite the shift in thinking needed to accomodate the demands of the faster, more complex cycle of knowledge creation and action needed today and in the future, especially in terms of how to best deal with unpredictability and complexity, and in terms of how people actually go about acquiring, creating and sharing knowledge

Evaluation of Bi-level Drainage Theory with a Viscous-flow Analog

The basic objective in the design of subsurface drainage systems is to determine the most economical placement of drain lines which will enable control of the water t able so that optimum crop growth is permitted. One way this goal can be achieved is to place drain lines at a depth and spacing that will not allow the water table to rise above a given elevation during the growing season . For example, the Bureau of Reclamation, in establishing design criteria for the proposed Oahe Unit irrigation project in central and northeastern South Dakota, stated that the water table should normally be more than three feet below the soil surface ( United States Department of the Interior, 1965). The Bureau estimated that drain lines placed nine feet deep and 790 feet apart would most economically meet the three foot design criteria for average Oahe Unit soil conditions. The installation of these drain lines requires the construction of open trenches, a method that has been used for centuries

New algorithms for the compilation of glacier inventories

Thesis (M.S.) University of Alaska Fairbanks, 2013Glacier inventories are used for many applications in glaciology, however, their manual compilation is time-consuming. Here, we present two new algorithms for the automatic compilation of glacier inventories. The first approach is based on hydrological modeling tools and separates glacier complexes into individual glaciers, requiring a digital elevation model (DEM) and glacier complex outlines as input. Its application to > 60,000 km² of ice in Alaska (~98% success rate) and southern Arctic Canada (~97% success rate) indicates the method is robust if DEMs and glacier complex outlines of good quality are available. The second algorithm relies on glacier outlines and a DEM and derives centerlines in a three-step 'cost grid -- least cost route' procedure. First, termini and heads are determined for every glacier. Second, centerlines are derived by determining the least cost route on a previously determined cost grid. Third, the centerlines are split into branches, followed by the attribution of a branch order. Application to > 21,000 Alaska glaciers shows that ~5.5% of the glacier heads and ~3.5% of the termini require manual correction. With corrected heads and termini, ~1.5% of the actual derived centerlines need edits. Comparison with alternative approaches reveals that the centerlines vary significantly depending on the algorithm used.Chapter 1. General introduction -- Chapter 2. A new semi-automatic approach for dividing glacier complexes into individual glaciers -- Chapter 3. A new method for deriving glacier centerlines applied to glaciers in Alaska and northwest Canada -- Chapter 4. General conclusions

Metaknowledge Management in Inquiring Organizations: Towards a Knowledge Ecology

Metaknowledge management is the judicious or strategic management or leveraging of the different ways in which we come “to know,” based on Churchman’s (1971) classic work, “The Design of Inquiring Systems” so that we respond to situations in the most appropriate way. It differs from knowledge management in that it is concerned more with how we know what we know than with what we know per se (information and knowledge). By helping individuals and organizations to understand and be aware of their preferred ways of thinking and knowing, in terms of Churchman’s inquiring systems, organizations can leverage their knowledge assets and collective wisdom to increase innovation and responsiveness. This workshop builds on, and provides a means to integrate, the Churchmanian based works of Courtney, Croasdell and Paradise’s (1998) work on Inquiring Organizations, Harrison and Bramson’s (1982) Inquiry Modes, Malhotra’s ( 1997, 1998) work on Knowledge Management in Inquiring Organizations and Knowledge Ecology, and Mitroff and Linstone’s (1993) work on New Thinking for the Information Age and Unbounded Systems Thinking. Such a synthesis can provide a practical and applied approach to the development of a knowledge ecology conducive to the generation and utilization of actionable knowledge at the individual, group, and organizational/community levels

Investigations of Heat-labile and Heat-stable Enterotoxins Produced by Escherichia Coli Isolated from Naturally Occurring Bovine Colibacillosis

Colibacillosis (CB) is a collective term which has been used to describe a group of diseases cause by the gram negative bacillus Escherichia coli. The disease affects neonatal calves, lambs, and piglets, weaned pigs and poultry. Certain E. coli also cause a diarrheal disease in human adults and infants. The research reported herein includes examination of 37 bovine E. coli strains to determine entero pathogenicity and the reliability of different assay methods, characterization of bovine LT ad comparison of bovine LT with porcine LT, comparison of three culture media to determine which one provides maximum ST production, and partial purification of bovine ST

Biomechanics of transapical mitral valve implantation

2014 Summer.Includes bibliographical references.Heart disease is the number one killer in the United States. Within this sector, valve disease plays a very important role: Approximately 6% of the entire population has either prolapse or stenosis of the mitral valve and this percentage only increases when looking only at the elderly population. Transapical mitral valve implantation has promised to be a potential therapy for high-risk patients presenting with MR; however it is unclear what the best method of securing a valve within the mitral annulus may be to provide a safe and efficient valve replacement. The objective of this research is to study and understand the underlying biomechanics of fixation of transapical mitral valves within the native mitral annulus. Two different transapical mitral valve prosthesis designs were tested: One valve design has a portion of the leaflets atrialized such that it has a shorter stent height and the valve itself sits within the native annulus, the other design is not atrialized and protrudes further into the left ventricle. The valves were implanted in a left heart simulator to assess leaflet kinematics and hemodynamics using high speed imagery and particle image velocimetry techniques. An in vitro passive beating heart model was then used to assess the two different fixation methods (namely, anchored at the apex vs. anchored at the annulus) with respect to paravalvular regurgitation. Leaflet kinematics and hemodynamics revealed proper leaflet coaptation and acceptable pressure gradients and inflow fillings; however, both designs yielded elevated turbulence stresses within the ventricle. At 60 beats per minute, leaflet opening and closing times were both under 0.1 seconds, max Reynolds shear stresses were between 40 and 60 N/m2 and maximum velocities were approximately 1.4 m/s. Assessment of the different fixation methods during implantation revealed the superiority of the atrialized valve when anchored at the annulus (p<0.05), but showed no such comparison during tethered implantation. In addition to the results of statistical testing, observations show that the importance of the relationship between ventricular stent height and fixation method compared with native anatomy plays an important role in overall prosthesis function regardless of implantation method

Inventory and analysis of tree injuries in a rockfall-damaged forest stand

Rockfall is a major threat to settlements and transportation routes in many places. Consequently, the protective function of mountain forests has recently gained particular interest. However, much is still unknown about the ideal properties of protective forest stands. Therefore the present paper discusses a method for the inventory and analysis of tree injuries in a rockfall-damaged forest stand. With this method, the interrelation between stand geometry and rockfall injuries in a subalpine Polygalo chamaebuxi-Piceetum was examined. The study site of 0.3Ha is located in the transit zone of frequently passing, small rockfall fragments (~10cm in diameter) causing healable tree injuries. Tree and injury parameters were recorded and analysed as to injury number, height and size. The spatial distribution of the 157 trees (diameter at breast height dbh>5cm) in the stand as well as of the 1,704 identified rockfall injuries showed a very uneven pattern. As expected, number, height and size of the injuries generally declined with increasing distance from the cliff as well as due to higher stem densities. In contrast, results indicated that the dbh of trees has no significant influence on the number of injuries per tree. However, this study showed a clear interrelation between tree and injury distribution: in general, large trees close to the cliff and smaller trees with a high density further down the slope seem to be favourable for good protection. At least an uneven-aged, multilayered stand should be sustained. Overall, the combined analysis of stand geometry and injury parameters provides information on the spatial distribution of rockfall and on the influence of tree arrangement

Trenched Plots Under Forest Canopies

The relative importance of light and soil moisture in particular is better known than that of other environmental factors. We are coming to believe that the nature and condition of the reproduction and other surface vegetation beneath living canopies are not due to any single factor such as light or soil moisture, but to a complex of factors