Digital Commons Network^™

Evaluating The Relationship Between Methane Seeps And Seafloor Geomorphology On The Northern Us Atlantic Margin, Gabriel Hernandez

Theses and Dissertations

Methane seeps are a transport pathway for carbon from seafloor sediments to the marine environment with important implications for global biogeochemical cycling. Accordingly, there is substantial interest in better understanding the processes that control seep location and predicting the distribution of seeps with existing seafloor datasets. Visual evaluation of methane seeps, in multibeam sonar water column data, suggests a spatial relationship between seeps and specific seafloor morphologic features such as ridge crests. In this thesis, seafloor geomorphology at 1996 seep detection sites on the US Atlantic margin was quantitatively characterized by geomorphologic phonotype, bathymetric position index, slope, rugosity, and aspect …

Digitizing Dinosaur National Monument's Carnegie Quarry, Rebecca Esplin

Theses and Dissertations

The Carnegie Quarry in northeastern Utah is world-renowned for the dinosaur skeletons it has produced and for its in situ display of dinosaur bones. The specimens excavated at Carnegie Quarry are displayed and curated in 20 repositories, most in North America. Data on these specimens in the forms of notes, photographs, publications, field maps, and so on, are scattered in an array of formats and institutions. The primary goal of this thesis is to develop a database linking these data with a digital map (GIS system) to make them readily accessible. To this end, a relational database was created using …

Utilizing Remote Sensing Imagery To Monitor Vegetation Change Within World Heritage Sites, Mimi Eve Hatzis

Theses and Dissertations

ABSTRACT

World Heritage sites provide a glimpse into the stories and civilizations of the past. There are currently 1007 unique World Heritage properties with 779 being classified as cultural sites, 197 as natural sites, and 31 falling into the categories of both cultural and natural sites (UNESCO & World Heritage Centre, 1992-2015). However, of these 1007 World Heritage sites, at least 46 are categorized as in danger and this number continues to grow. These unique and irreplaceable sites are exceptional because of their universality. Consequently, since World Heritage sites belong to all the people of the world and provide inspiration …

The Rate And Timing Of Direct Mountain Front Recharge In An Arid Environment, Silver Island Mountains, Utah, Gregory T. Carling

Theses and Dissertations

Direct mountain front recharge (MFR), water table recharge at the base of the mountain front, was evaluated on the arid (<250 mm/yr precipitation) Silver Island Mountains by comparing mountain precipitation to groundwater response. Direct MFR contributions were assessed on two catchments, one bedrock (i.e., mountain block) dominated and the other alluvial fan (i.e., mountain front) dominated. Catchment precipitation and shallow groundwater levels at each catchment outlet were measured for a 24 month period beginning October 2005. This time period captured one complete hydrologic cycle (December 2005-February 2007) for which annual and seasonal direct MFR rates were calculated. Annual direct MFR was calculated using a modified version of the water table fluctuation (WTF) method as 0.015-0.016% of precipitation on both catchments, with seasonal variations of 0% in summer up to 0.023% in winter, spring and fall. Seasonal direct MFR contributions are similar on the bedrock and the alluvial fan dominated catchments, with a notable exception during fall 2006 when direct MFR was twice as effective on the bedrock dominated system than on the alluvial fan dominated system (0.022% and 0.011% of precipitation, respectively). Darcy's law calculations show similarly low annual direct MFR contributions (0.013-0.032% of precipitation) as those calculated by the WTF method. Calculated direct MFR is 10% or less than typical calculated combined MFR (near surface recharge and deep underflow from the mountain block) for similar terrains and climates, and is only 3.5% of the combined MFR for the Silver Island Mountains as calculated by the Maxey-Eakin model. However, based on total recharge to the adjacent playa, it is apparent that the Maxey-Eakin model overestimates combined MFR, and the small calculated direct MFR is at least 50% of combined MFR. Despite some uncertainty in the numerical results, several patterns are evident in the data. The data show that direct MFR occurs in response to small rainfall events throughout much of the year, and that snowmelt is not necessary to produce direct MFR. The data also show that direct MFR responds more quickly and flushes through the system faster on the alluvial fan catchment than on the bedrock catchment.

Pre-Historic Landslides On The Southeast Flank Of The Uinta Mountains, Utah: Character And Causes Of Slope Failure, Todd D. Bradfield

Theses and Dissertations

More than 100 landslides have been mapped along the southeast flank of the Uinta Mountains. Large landslide deposits are up to 4.6 kilometers long and have an area of approximately 5-9 km². Landslide types include multiple and successive rock slumps, debris slumps and debris flows. Most landslides have a main head scarp in the Bishop Conglomerate and the large landslides have many minor scarps. Multiple slump blocks are manifest by repeated transverse ridges and trenches in the head area of some landslides. Most body and toe areas are deeply incised by gully erosion (up to 91 meters deep) and drainages …

Pluton Zonation Unveiled By Gamma-Ray Spectrometry And Magnetic Susceptibility; A Case Study Of The Sheeprock Granite, Western, Utah, Paul D. Richardson

Theses and Dissertations

A radiometric survey of the zoned 21 Ma, A-type Sheeprock granite, western Utah, combined with measurements of magnetic susceptibility and field observations were analyzed using a geographic information system. The intrusion spans 25 square km and is roughly eliptical in shape with its long axis trending northwest. Concentration maps (composed of more than 500 survey stations) of eU, eTh, texture, magnetic susceptibility, color, and joint density help to constrain magmatic and post-magmatic processes related to its chemical and physical zonation. Uranium ranges from 3.9 to 26.9 ppm (mean 12.7) and thorium from 1.7 to 125.7 ppm (mean 45.5). Similarities in …