Earth Sciences Commons^™

Evidence Of Atmospheric Gravity Waves During The 2008 Eruption Of Okmok Volcano From Seismic And Remote Sensing Observations, S. De Angelis, Stephen R. Mcnutt, P. W. Webley

School of Geosciences Faculty and Staff Publications

Okmok volcano erupted on July 12, 2008, following an 11-year hiatus. Detailed inspection of the syn-eruptive seismograms revealed the presence of an ultra long-period mode at a frequency of 1.7 mHz, which is not a characteristic of the background seismic noise at Okmok. Data collected by the National Oceanic and Atmospheric Administration Geostationary Operational Environmental Satellite (GOES) and National Aeronautical and Space Administration Moderate Resolution Imaging Spectroradiometer (MODIS) sensors displayed the propagation of a vigorous ash-and-steam plume up to about 17 km above sea level. We suggest that the observed ultra long-period signals represent the response of the seismometer to …

Quantifying Evapotranspiration And Water Table Interactions In Regions Of Shallow Groundwater: Sensitivity To Soil Properties, Vegetation, And Climate Variability, Mehmet E. Soylu

School of Natural Resources: Dissertations, Theses, and Student Research

Evapotranspiration (ET) is an important component of the water and energy balance, yet it is also one of the most challenging components to estimate. There has been great effort to understand the nature of controlling mechanisms and interactions between ET and other earth system processes. The controlling factors of ET can be grouped into two broad categories – namely moisture availability and energy availability (e.g., solar radiation). Soil moisture is a key factor that most of the land surface hydrologic processes are dependent on. While plant water use is mainly controlled by radiation, temperature is another key factor for ET …

Process-Based Management Of Downy Brome In Salt Desert Shrublands: Assessing Pre- And Post- Rehabilitation Soil And Vegetation Attributes, Merilynn Carol Hirsch

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As an ecosystem driver, downy brome (Bromus tectorum L.) presents obstacles to land rehabilitation efforts, including restoring desirable species cover. Because damaged ecosystems may have crossed both abiotic and biotic thresholds, ecologically-based control strategies may assist with altering successional trajectories and restoring desirable plant species. My thesis research had three objectives: 1) assess soil and vegetation relationships in degraded salt desert ecosystems prior to implementing downy brome control treatments, 2) determine the effects of control treatments on soil properties and resident plant species, and 3) evaluate the relative importance of shrubland soil type, herbicide type, and herbicide rate on seedling …

Pleistocene Climate In Alaska From Stable Isotopes In An Ice Wedge, Corinne Y. Griffing

UNLV Theses, Dissertations, Professional Papers, and Capstones

The CRREL permafrost tunnel offers a unique opportunity to sample ice wedges in a climate-controlled environment, penetrating frozen silts which host massive ground ice that may record Dansgaard-Oeschger (D-O) and Heinrich Events. Ice wedges in the tunnel have been dated to approximately 36-22 ka (Hamilton et al., 1988), allowing the paleoclimate of the region to be reconstructed during MIS 3, when D-O and Heinrich events were documented in various other records. These climate cycles are rapid climate oscillations that have been recognized in records from the Arctic and subarctic, and suggest that climate can rapidly shift by 10°C over millennial …

Complex Vs Profiles To 100 M Depth From Rayleigh Waves And 3-D Vs Model For Las Vegas Valley, Helena Murvosh

UNLV Theses, Dissertations, Professional Papers, and Capstones

A three-dimensional (3-D) shear wave velocity (VS) model was developed for the heterogeneous shallow sediments (to nearly 400 m) of the Las Vegas Valley (LVV), Nevada. The model was based on more than 200 VS profiles and 1400 geologic well logs. Five sediment units including a cemented unit were defined from geologic log descriptions. A characteristic VS profile for four of the units was obtained by correlating between closely spaced pairs of VS and sediment data; a constant VS was assigned to the cemented unit. VS profiles were then assigned to each well location based on type of sediment according …

Molecular Organic Geochemistry Of The Oil And Source Rocks In Railroad Valley, Eastern Great Basin, Nevada, United States, Laode Ahdyar

UNLV Theses, Dissertations, Professional Papers, and Capstones

A comprehensive geochemical study of oils from Railroad Valley, Nevada and two candidate source rock intervals from the nearby Egan Range, was conducted in order to establish oil-oil and oil-source rock correlations. Analyses consisted of total organic carbon, Rock-Eval pyrolysis, and vitrinite reflectance for source rock samples, as well as biomarker, diamondoids, and stable carbon isotope analyses on source rock extracts and oil samples.

Total organic carbon analyses showed high organic content in the Mississippian Chainman Shale. However, outcrop samples of the Paleogene Sheep Pass Formation Member B are organically lean. Strata in both of these units are immature to …

Lateral Variability Of Facies And Cycles In The Furongian (Late Cambrian) Carbonate Platform: An Example From The Big Horse Member Of The Orr Formation In Western Utah, U.S.A., Ratna Widiarti

UNLV Theses, Dissertations, Professional Papers, and Capstones

Carbonate depositional cycles and sequences have been proposed to be formed by glacioeustatic sea-level changes. This mechanism would be questionable during times of high atmospheric CO2 and negligible continental ice sheets such as the supergreenhouse time in the Furongian (late Cambrian), during which limited glacioeustatic sea-level changes would be expected. A detailed sedimentological study of the Furongian Orr Formation in western Utah is aimed at testing the hypothesis that, under supergreenhouse climate conditions, most meter-scale carbonate cycles may have been formed through autocyclic processes and thus they should be laterally variable. The research was conducted in a small area ( …

Impacts Of Climate Change And Weather Modification On Hydrologic Characteristics Of Watersheds In The Western United States, Anil Acharya

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research quantifies the impacts of climate change and weather modification (WM) on hydrologic characteristics of watersheds in the arid regions of the western United States. This research performs a long-term simulation of streamflow for present and future climate conditions in the North Platte (NP) Watershed, Wyoming; a shorter duration simulation is then performed to observe the likely impacts of event based changes in an urban watershed in Las Vegas, Nevada.

First, a study is carried out in Chapter 3 that evaluates the impacts of WM on water supply by developing a hydrologic model for the NP Watershed. The variable …

Co-Development Of Biological Soil Crusts, Soil-Geomorphology, And Landscape Biogeochemistry In The Mojave Desert, Nevada, U.S.A. – Implications For Ecological Management, Amanda Jean Williams

UNLV Theses, Dissertations, Professional Papers, and Capstones

Biological soil crusts (BSCs) are complex matrices of soil particles, mosses, lichens, and cyanobacteria that prevent erosion and influence water and energy balances, soil fertility, and vascular plant germination. The processes that form BSCs, the factors that control their distribution, and the ecosystem feedbacks that they sustain are poorly understood. This dissertation employed a novel interdisciplinary approach to address those research unknowns through investigations of the micromorphological structure, soil-geomorphic relationships, and biogeochemical feedbacks of BSCs in the Mojave Desert.

A micromorphological study of BSCs resulted in a succession model that illustrates how crust formative processes and structures change through time. …

Mesozoic Burial, Mesozoic And Cenozoic Exhumation Of The Funeral Mountains Core Complex, Death Valley, Southeastern California, Mengesha Assefa Beyene

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Funeral Mountains of Death Valley National Park, CA, provide an opportunity to date metamorphism resulting from crustal shortening and subsequent episodic extensional events in the Sevier hinterland. It was not clear whether crustal shortening and thus peak temperature metamorphism in the hinterland of the Sevier-Laramide orogenic wedge have occurred whether in Late Jurassic, Early Cretaceous , Late Cretaceous or somewhere between. Particularly ambiguous is the timing of crustal shortening in the deep levels of the hinterland of the Sevier belt, now manifest in the metamorphic core complexes, and how and when these middle-to-lower crustal rocks were exhumed. A 6-point …

Vertebrate Taxonomic Composition, Species Diversity, And Paleoecology Of Two Pliocene Mid-Latitude, Inland-Basin Fossil Assemblages: Panaca Local Fauna (Lincoln County, Nevada) And Hagerman Local Fauna (Twin Falls County, Idaho), Vicki Lynn Meyers

UNLV Theses, Dissertations, Professional Papers, and Capstones

I studied the sedimentology, species diversity, relative abundance, paleoenvironment, and paleoecology of the vertebrate fauna of the early Pliocene (Blancan Land Mammal Age) Panaca Formation of southeastern Nevada, and I compared these data with the slightly younger Hagerman fauna of south-central Idaho. The purpose of this study is to characterize the paleoecology and species diversity of mid-latitude inland basins during the Blancan Land Mammal Age, a time of climate change and immigrating taxa from Asia and South America. This study involved surface collecting and screenwashing of the Panaca Formation sediment in Meadow Valley, as well as a compilation of data …

Extent Of Gully Erosion In An Agricultural Field In Northeastern Nebraska At Section 35 Township 29 North Range 1 West In Cedar County, Crystal Starkel

Department of Environmental Studies: Undergraduate Student Theses

My thesis project examined a gully within Section 35 Township 29 North Range 1 West. This gully has been noticed for five years and has grown substantially in those five years. The extent and causes of gully erosion were examined by considering the soil, the climate, the land management history, by measuring the gully physically, by using GIS, and by using an economic support tool was estimate soil loss. Appropriate recommendations were developed to reduce gully erosion.

Improving Energy Sustainability In Pound Hall, Craig Adams

Department of Environmental Studies: Undergraduate Student Theses

This research project deals with improving energy sustainability in Pound Hall dormitory located on the University of Nebraska at Lincoln’s (UNL) city campus.  An investigation on the current energy usage of Pound Hall showed that its energy rates worsened between the years of 2009 and 2010.  These combined (electricity, steam, and water) energy rates were compared with those of the newly renovated Othmer Hall to emphasize the lack of sustainability in the older dormitory.  In order to improve Pound Hall’s energy rates, an energy benefit analysis of implementing a green roof was performed.  Having a green roof on this dormitory …

Population Structure Based On Age-Class Distribution Of Tapirus Polkensis From The Gray Fossil Site Tennessee., Matthew L. Gibson

Electronic Theses and Dissertations

Individuals of Tapirus polkensis from the Gray Fossil Site exhibit an excellent level of preservation. Intact skulls collected from the site were arranged in a rough age class system separated into 7 categories based on the teeth present and amount of dental wear. Such an eruption series is useful for general comparisons amongst the individual tapirs; however, the classes do not represent an age in years due to a lack of data on living tapirs. Consequently, it is possible that some age classes may contain several years of a tapirs life, or comparatively only a few months. In this study …

An Analysis Of The Stability And Transport Of Co2 On Mars And Iapetus: Increasing Accuracy Via Experiments And Photometry, David Garrison Blackburn

Graduate Theses and Dissertations

Volatile transport of carbon dioxide is most relevant on two planetary bodies in our solar system: Mars and Iapetus. We experimentally measured the sublimation rate of CO2 ice under simulated martian conditions and developed a model based on our experimental results. We experimentally verified that solar irradiance is the primary control for the sublimation of CO2 ice on the martian poles with the amount of radiation striking the surface being controlled by variations in the optical depth, ensuring the formation and sublimation of the seasonal cap. Our model, supported by comparison of MGS-MOC and MRO-HiRISE images, shows that ~ 0.4 …

Geochemical Controls On Mercury Methylation In Backwaters Of A Gulf Coastal Plain River System, Implications For Water Column Processes, Liam N. Schenk

Graduate Theses and Dissertations

The abundance and distribution of mercury and methyl mercury were investigated at three sites in the lower Ouachita River in the summer of 2010 in an effort to provide the first characterization of the extent of mercury contamination in this river system, and to investigate the potential for mercury methylation in the water column of backwaters off of the main channel. Results showed that filtered methyl mercury was positively correlated to dissolved organic carbon (r2=0.76) for water samples taken from the bottom 1 ft of the water column at three sites, suggesting the importance of dissolved organic carbon in mercury …

Determining Middle Miocene Through Pliocene Changes In Provenance And Basal Ice Conditions Through Sedimentological Analyses Of Subglacial Diamictites In And-2a, Ross Sea, Antarctica, Melissa Anne Hansen

Theses, Dissertations and Culminating Projects

Prior to the mid-Miocene the Antarctic ice sheet is believed to have been very dynamic with periods of expansion and contraction (Naish et ah, 2001). Previous studies have suggested that the ice sheet changed from a wet-based temperate ice-sheet to a drybased polar ice sheet at ca. 14 Ma (Lewis et al., 2007). Utilizing a sediment core obtained through the Antarctic Geological Drilling (ANDRILL) program, changes in the flow configurations and conditions in the basal ice were documented across the middle Miocene climate transition. Glaciers eroded bedrock from the Transantarctic Mountains and deposited sediments into the embayment mixing with materials …

Geochemical Analysis And Regional Correlations Bbetween Granitic Gneisses Of The Western Hudson Highlands, New York, Elyse Kirsten Peterson

Theses, Dissertations and Culminating Projects

The Byram Intrusive Suite granite gneisses of the New Jersey Highlands are believed to be similar in chemical composition as well as age to the Storm King hornblende granite gneisses of the Hudson Highlands of New York (Drake et al., 1991, Ratcliffe and Aleinikoff, 2001; Volkert et ah, 2010). The goal of this project is to determine the geochemical continuity between the Byram Intrusive Suite of the NJ Highlands and the Storm King granite gniesses, located near Bear Mountain, NY. Thirtytwo samples of granitic gneisses with similar field relations and textures to the Byram and Storm King granite gneisses were …

Salt Contamination Of Ground And Surface Water In Connecticut: A Compilation And Synthesis Of Historic Data And Local Scale Testing, James P. Cassanelli

Master's Theses

No abstract provided.

About A Peri-Gondwanan-North African Enlarged Acceptance Of The Caledonian Orogeny, Ioan Balintoni, Constantin Balica, Horst-Peter Hann

Studia UBB Geologia

The notion of “Caledonian Orogeny” is restricted by most authors to the Ordovician-Devonian thermotectonic events associated with the Laurentia-Baltica- Avalonia suturing. However, some views consider an orogeny as the sum of tectonic, metamorphic and magmatic events accompanying an entire supercontinent assembly or Wilson cycle. Following this line of thinking, the Caledonian and Variscan orogenies successively assembled Pangea. During the Ordovician Period, rifting, collision, deformation, metamorphism and magmatism took place within the Gondwana margin. All these events are known today in the basement of the Cadomian terranes from Iberia through the Alps up to the Romanian Carpathians and Balkans. We plead …

In Memoriam, Lukas Plan, Michele Citterio

Studia UBB Geologia

In Memoriam - Willi Dansgaard & Robert Seemann

Verification Of The Cobb Snowfall Forecasting Algorithm, Josh Barnwell

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

 Forecasting storm total snow accumulation is one of the most difficult aspects of meteorological forecasting.  The forecaster has to interpret three main variables in order to forecast snowfall accurately.  These forecasting variables are the duration of the snowfall, the amount of liquid water the storm will produce, and the snow density or snow ratio.  With the advancement of computer models in recent history, the need for a quick and easy interpretation of these variables has grown, and to improve on previous forecasting techniques’ disadvantages with including the three snow forecasting variables.  The Cobb Method snowfall forecasting algorithm utilizes model data …

Geologic Mapping Of Exhumed, Mid-Cretaceous Paleochannel Complexes Near Castle Dale, Emery County, Utah: On The Correlative Relationship Between The Dakota Sandstone And The Mussentuchit Member Of The Cedar Mountain Formation, Amanda Elizabeth Mackay Sorensen

Theses and Dissertations

Numerous well-preserved, exhumed paleochannels in the Morrison, Cedar Mountain and Dakota Sandstone formations are exposed east of Castle Dale, Utah. These channels consist primarily of point bar complexes and scattered, low sinuosity channels. To determine the vertical and lateral relationships of these channels within the Cedar Mountain and Dakota Sandstone formations, a 1:24,000 scale geologic map covering ~140 km2 was created showing the fluvial sandstones. In the study area the Cedar Mountain Formation consists, from bottom to top, of 2.5-10 m of Buckhorn Conglomerate Member equivalent units, ~80 m of the Ruby Ranch Member, and ~30 m of the Mussentuchit …

Groundwater: Solution To The Las Vegas Water Problem?, Rosa Perez, Christopher Ruiz

Festival of Communities: UG Symposium (Posters)

A contentious debate is taking place in different sectors of the community on how to manage the states groundwater system. It is a battle whose outcome, regardless of who wins, will have a tremendous impact on the future of Las Vegas. Economic benefits always seem to downplay environmental considerations in the policy-making process often with serious consequences. This paper takes a look at the SNWAʼs Groundwater Development Project and provides a discussion of the issues for and against it. Groundwater is inexpensive, relatively abundant and accessible. However, over-pumping of groundwater can have significant environmental consequences, as well. It is our …

Elastic Plastic Self Consistent (Epsc) Modeling Of Plastic Deformation In Fayalite Olivine, Christopher J. Cline Ii, Pamela Burnley

Festival of Communities: UG Symposium (Posters)

We are using an Elastic Plastic Self Consistent Model (a type of numerical simulation) to study deformation of olivine. Olivine is one of the major constituents of the Earth’s upper mantle and its deformation properties have an important influence on how the Earth’s crust deforms. For example, the flow strength of olivine limits the size of the largest earthquakes and the heights of the tallest mountains on Earth. By comparing the results of our simulations with data from olivine deformation experiments we are able to better interpret the experimental data.

Volatile Bubble Growth In The Aztec Wash Pluton, Brett Perry, Adam Simon, Rachael Johnsen

Festival of Communities: UG Symposium (Posters)

Plutons are well preserved magma chambers that have been preserved in the rock record and allow the study of magmatic processes. Magma chambers are composed of silicate magmas, crystals, and volatiles. Volatiles are a key control in driving eruptive processes, which vent greenhouse gases into the atmosphere, thus a better understanding of the mechanisms of volatile transport within a pluton is necessary. Microscopy was used to analyze the size and density of cavities and feldspars from various stratigraphic sections of the pluton. Microscopy showed that cavities were a result of volatile partial pressure, as well as, a progressive increase in …

In-Situ Synchrotron X-Ray Diffraction Study Of Quartz Deformation Using The D-Dia Apparatus, May Sas, Dawn Pape, Brian Erickson, Sylvia-Monique Thomas, Pamela Burnley

Festival of Communities: UG Symposium (Posters)

Deformation is a rock’s mechanical response to external parameters such as temperature and pressure. Knowledge of deformation is necessary to understand geodynamic processes. The behavior of rocks and minerals during deformation depends on the behavior of individual grains within those minerals as they interact. The mineral we are studying is quartz, which we chose since it is very well studied and is highly abundant. We use high-pressure high temperature experiments to simulate conditions of Earth’s interior and the D-DIA apparatus combined with synchrotron x-ray diffraction allows us to record data directly during the process of deformation. The data we collect …

Serpentinite Weathering And Implications For Mars, Valerie Tu, Julie Baumeister, Rodney Metcalf, A. Olsen, Elisabeth Hausrath

Festival of Communities: UG Symposium (Posters)

In the search for life on Mars near-surface soil environments may be important habitats for life accessible to future missions. Serpentinite rocks have been documented on Mars, as well as other clay minerals including smectite and kaolinites. Previous studies of soils formed on serpentinites on Earth have documented the formation of extensive clays. Serpentinites are additionally of interest as habitats for life such as methanogens. Here we examine weathering of serpentinites from bedrock to soil surface, as a potential route for the formation of clay minerals on Mars from abundant ultramafic minerals. We additionally test for the presence of Fe-oxidizing …

Melt Inclusions In Volcanic Rocks, Kirellos Sefein, Kelly L. Robertson, Adam Simon

Festival of Communities: UG Symposium (Posters)

We studied melt inclusions from Mutnovsky Volcano, Kamchatka, Russia as part of a larger project designed to contrain the eruptive history of Mutnovsky. Transmitted and reflected light petrographic microscopy was used to characterize melt inclusions in grain mounts of mineral separates, standard 30 micron thin sections, and 200 micron thick sections of the samples from the Mutnovsky. The inclusions were further divided into three main categories: recrystallized, partially recrystallized, and glassy inclusions. After all the melt inclusions have been categorized, they will be analyzed by using LA-ICP-MS to determine their major, minor and trace element compositions.

Evaluation Of Drought Indices Based On Thermal Remote Sensing Of Evapotranspiration Over The Continental United States, Martha C. Anderson, Christopher R. Hain, Brian Wardlow, Agustin Pimstein, John R. Mecikalski, William P. Kustas

National Drought Mitigation Center: Faculty Publications

The reliability of standard meteorological drought indices based on measurements of precipitation is limited by the spatial distribution and quality of currently available rainfall data. Furthermore, they reflect only one component of the surface hydrologic cycle, and they cannot readily capture nonprecipitation-based moisture inputs to the land surface system (e.g., irrigation) that may temper drought impacts or variable rates of water consumption across a landscape. This study assesses the value of a new drought index based on remote sensing of evapotranspiration (ET). The evaporative stress index (ESI) quantifies anomalies in the ratio of actual to potential ET (PET), mapped using …