<p dir="ltr">This research aims to examine the effect that mantle tractions have on surface deformation throughout the Pacific-North America plate boundary zone in Alaska, western Canada, and the Bering Sea region. We use 3-D geodynamic models to simulate the crust and upper mantle in order to investigate the tectonic force balance between plate boundary interactions, gravitational collapse, and basal tractions. We determine that mantle tractions with a magnitude of ~2.5-3.8 MPa, directed to the southeast, in conjunction with forces from the Yakutat flat slab, best fit the steady-state plate motion estimates in Alaska. We also show how these mantle tractions have likely aided in concentrating deformation to the northwest of incoming Yakutat oceanic plateau throughout the ~50 Ma evolution of flat slab subduction in this region. Finally, we conclude that mantle tractions also impact the broad zone of distributed deformation surrounding the Bering Sea. The confluence of basal forces and tectonic extrusion, due to the Yakutat flat slab, may lead to the evolution of a new plate boundary extending from northwest Alaska to the Kuril-Kamchatka subduction zone.</p>

No description available.

<p>Seasonal road design in mountainous terrain consists of four main phases: route selection, field investigation, surveying, and analysis. The first phase, route selection, consists of two parts: selecting control points at strategic locations, and then determining potential routes between those points. Two geographic information system (GIS) geoprocessing automations were developed to aid a road planner in determining routes between control points. Both automations utilized Environmental Systems Research Institute&rsquo;s (ESRI) ArcGIS software package. The first method developed was the least cost path method, which makes use of ArcGIS&rsquo;s cost path tool to find a route between points following a gradual slope. The second automation was the side hill method, which utilized a variety of ArcGIS tools to maintain a uniform grade along the side of a hill between two points. The two methods were compared and contrasted based on control point locations. The least cost path method was determined to be preferable for main thoroughfares along flat valleys and ridge lines, while the side hill method was preferable for secondary roads that could be used to access steeper ground. It was concluded that the two methods can save time and increase accuracy of GIS road features for land managers planning new seasonal roads. </p>

<p> This single-case study was to explore how Geographical Information Systems (GIS) could contribute to reducing dropout and non-attainment rates in Nepal&rsquo;s secondary school system. GIS specialists analyzed information collected from parents on why their school-age children either dropped out or otherwise did not attain a secondary school education. The sample size in this study was eight, which included five sets of parent(s) whose children ages 13 to 16; either dropped out or otherwise did not attend a secondary school system, and three GIS specialists. Economics, teachers, and government were three themes that emerged from the parents&rsquo; interview. Interviews with GIS specialists reveled that GIS could assist in addressing dropout and non-attainment issues. In the context of Nepal, GIS is a still a new technology. The Government of Nepal lacks adequate infrastructure in areas of human resources, training and technical resources, and the central data repository system required for the proper use of GIS. GIS specialists recommended augmenting Nepal's information technology infrastructure by implementing a sustainable Enterprise GIS, and an Educational Management Information System. This research work recommends that identification of strategic solutions for student retention issues will require a concerted effort by not only governmental leadership, but also policy-makers, and non-government community leaders. The Government of Nepal may need to play vital role in overcoming existing economic and political barriers to improve IT infrastructure. GIS technology is certain to emerge as an important tool for making a difference in the planning process for minimizing dropout rates and enhancing enrollment ratios across the country. The recognition of both a need for change and the changes required are two important themes that emerged from the research study.</p>

<p> There is a global need for energy technologies that reduce the adverse impacts of societal progress and that address today's challenges without creating tomorrow's problems. Life cycle impact assessment (LCIA) can support technology developers in achieving these prerequisites of sustainability by providing a systems perspective. However, modeling the early-stage scale up and impacts of technology systems may lead to unreliable or incomplete results due to a lack of representative technical, spatial, and temporal data. The goal of this dissertation is to support the acceleration of clean energy technology development by providing information about the regional variation of impacts and benefits resulting from plausible deployment scenarios. Three emerging energy technologies are selected as case studies: (1) brine management for carbon dioxide sequestration; (2) carbon dioxide capture, utilization, and sequestration; (3) stationary fuel cells for combined heat and power in commercial buildings. In all three case studies, priority areas are identified where more reliable data and models are necessary for reducing uncertainty, and vital information is revealed on how impacts vary spatially and temporally. Importantly, moving away from default technology and waste management hierarchies as a source of data fosters goal-driven systems thinking which in turn leads to the discovery of technology improvement potentials.</p>

<p> The Coastal and Marine Ecological Classification Standard (CMECS) provides a comprehensive framework of common terminology for organizing physical, chemical, biological, and geological information about marine ecosystems. Federally endorsed as a dynamic content standard, all federally funded data must be compliant by 2018; however, applying CMECS to deep sea datasets and underwater video have not been extensively examined. The presented research demonstrates the extent to which CMECS can be applied to deep sea benthic habitats, assesses the feasibility of applying CMECS to remotely operated vehicle (ROV) video data in near-real-time, and establishes best practices for mapping environmental aspects and observed deep sea habitats as viewed by the ROV&rsquo;s forward-facing camera. All data were collected during 2014 in the Northern Gulf of Mexico by the National Oceanic and Atmospheric Administration&rsquo;s (NOAA) ROV <i> Deep Discoverer</i> and ship <i>Okeanos Explorer.</i></p>

<p> Healthcare access is a highly reported problem for immigrant populations in the United States, especially for Hispanic migrants at the US-Mexico border. This statement holds particularly true for populations living in unincorporated communities known as <i>colonias</i> in the borderland region. Residents of a <i>colonia</i> are estimated to suffer from preventable or treatable illnesses including tuberculosis, hepatitis A, cholera, hypertension, type 2 diabetes, depression, substance abuse, among other health problems, at two to four times the national average (Matthiesen 1997; Anders et al. 2010:366; Mier et al. 2013:208; Sharkey et al. 2011; Davidhizar 1999). This apparent disparity is a result of unequal healthcare access due to social, legal, economic, and physical/spatial barriers. Using a structural violence framework as a lens, this study attempted to determine the barriers impeding access to healthcare for <i>colonia</i> residents, as well as analyze the interrelationships between the types of barriers. This study utilized semi-structured interviews to gain an understanding of perceived social, legal, spatial/physical, and other suggested barriers preventing healthcare access in El Paso County, TX <i>colonias</i>. In order to fully demonstrate the role of spatial/physical barriers on access to care, this study utilized Geographic Information Systems (GIS) to map obstacles in the targeted communities.</p>

<p> This study compared two remote sensing water indices: the Normalized Difference Water Index (NDWI) and the Modified NDWI (MNDWI). Both indices were calculated using publically-available data from the Landsat 8 Operational Land Imager (OLI). The research goal was to determine whether the indices are effective in locating open water and measuring surface soil moisture. To demonstrate the application of water indices, analysis was conducted for freshwater wetlands in the Tualatin River Basin in northwestern Oregon to estimate hydrologic connectivity and hydrological permanence between these wetlands and nearby water bodies. Remote sensing techniques have been used to study wetlands in recent decades; however, scientific studies have rarely addressed hydrologic connectivity and hydrologic permanence, in spite of the documented importance of these properties. Research steps were designed to be straightforward for easy repeatability: 1) locate sample sites, 2) predict wetness with water indices, 3) estimate wetness with soil samples from the field, 4) validate the index predictions against the soil samples from the field, and 5) in the demonstration step, estimate hydrologic connectivity and hydrological permanence. Results indicate that both indices predicted the presence of large, open water features with clarity; that dry conditions were predicted by MNDWI with more subtle differentiation; and that NDWI results seem more sensitive to sites with vegetation. Use of this low-cost method to discover patterns of surface moisture in the landscape could directly improve the ability to manage wetland environments.</p>

<p> People often become disoriented when navigating in complex, multi-level buildings. To efficiently find destinations located on different floors, navigators must refer to a globally coherent mental representation of the multi-level environment, which is termed a multi-level cognitive map. However, there is a surprising dearth of research into underlying theories of why integrating multi-level spatial knowledge into a multi-level cognitive map is so challenging and error-prone for humans. This overarching problem is the core motivation of this dissertation.</p><p> We address this vexing problem in a two-pronged approach combining study of both basic and applied research questions. Of theoretical interest, we investigate questions about how multi-level built environments are learned and structured in memory. The concept of multi-level cognitive maps and a framework of multi-level cognitive map development are provided. We then conducted a set of empirical experiments to evaluate the effects of several environmental factors on users' development of multi-level cognitive maps. The findings of these studies provide important design guidelines that can be used by architects and help to better understand the research question of why people get lost in buildings. Related to application, we investigate questions about how to design user-friendly visualization interfaces that augment users' capability to form multi-level cognitive maps. An important finding of this dissertation is that increasing visual access with an X-ray-like visualization interface is effective for overcoming the disadvantage of limited visual access in built environments and assists the development of multi-level cognitive maps. These findings provide important human-computer interaction (HCI) guidelines for visualization techniques to be used in future indoor navigation systems. </p><p> In sum, this dissertation adopts an interdisciplinary approach, combining theories from the fields of spatial cognition, information visualization, and HCI, addressing a long-standing and ubiquitous problem faced by anyone who navigates indoors: why do people get lost inside multi-level buildings. Results provide both theoretical and applied levels of knowledge generation and explanation, as well as contribute to the growing field of real-time indoor navigation systems.</p>

Em função da rapidez e precisão na obtenção de coordenadas, o Global Positioning System (GPS) revolucionou o posicionamento espacial. Entretanto, a maior necessidade em aplicações nas áreas de Geodésia, Geofísica e Engenharia, em termos de altitude, é voltada para a altitude ortométrica e não para a elipsoidal (determinada por GPS). Um modelo de ondulação geoidal mais acurado possibilitaria tranformar altitudes elipsoidais em ortométricas, mantendo o mesmo nível de precisão da determinação GPS. Neste trabalho foram gerados modelos geoidais gravimétricos para o Brasil, GEOIDE2005 e STOKES2005, por meio da técnica 'remover-calcular-repor' em conjunto com a modificação do núcleo da integral de Stokes proposta por Featherstone, no caso do cálculo por FFT, e a proposta por Vanicek e Kleusberg, para o cálculo por integração numérica. As informações gravimétricas utilizadas no cálculo, provenientes de diversas instituições brasileiras e sul-americanas, foram compiladas, validadas e homogeneizadas de modo a gerar uma malha de 10' x 10' de anomalias médias de gravidade de Helmert, em continente, e ar-livre, nas áreas oceânicas. A contribuição dos longos comprimentos de onda do geóide, relativa à área externa à calota de integração, é fornecida por um modelo de geopotencial. A escolha desse modelo foi feita a partir de comparações de diferentes modelos de geopotencial para identificar o que melhor se ajusta ao país. O modelo digital de terreno foi selecionado a partir de estudos detalhados e foi utilizado para gerar valores de altitudes médias, reconstituir anomalias Bouguer em Helmert, calcular correção de terreno e efeito indireto. Foram organizadas e analisadas informações sobre estações que possuíam altitude elipsoidal, determinada por levantamentos GPS, e altitude ortométrica, obtidas por meio de nivelamento geométrico. A diferença entre essas duas altitudes forneceu as ondulações geoidais utilizadas para avaliação dos modelos de geopotencial e dos modelos geoidais aqui apresentados. Ao final, são relacionados os resultados das comparações, relatadas conclusões, levantadas as perspectivas futuras e sugeridas recomendações para futuros trabalhos. / The Global Positoning System (GPS) generated a revolutionon on coordinates acquisition, considering quickness and precision. However, the major need in Geodesy, Geophysics and Engineering areas, regarding heights, is directed to orthometric height, not to ellipsoidal (determined by GPS). A more accurate geoid undulation model would allow the transformation of ellipsoidal to orthometric heights, keeping the same precision level of GPS determinations. This work generated gravity geoid models to Brasil, GEOIDE2005 and STOKES2005, using the “remove-restore" technique together with the modification of Stokes integral kernel proposed by Featherstone, in FFT computation, and the Vanicek and Kleusberg proposal, in numerical integration computation. The gravimetric informations used in the computations, from several Brazilian and South American organizations, were compiled, validated and homogenized to generate a 10’x 10’Helmert mean gravity grid, on terrestrial areas, and free-air, on ocean. The geoid long wavelength contribution, related to integration cap’s external area, is provided by a geopotential model. The choice of this model was done from comparisons of different geopotential models in order to identify the one that best fits to the country. The digital terrain model was selected from detailed studies and was used to generate mean height values, reconstitute Helmert anomalies from Bouguer, compute terrain correction and indirect effect. Informations about stations with ellipsoidal height, determined by GPS surveys, and orthometric height, obtained by spirit levelling,, were organized and analyzed. The differences between these two heights provided the geoid undulations used to evaluate geopotential models and geoid models presented here. At the end, the results from comparisons and conclusions are informed, future perspectives are raised and recommendations are suggested.