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Earth Sciences

2011

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Full-Text Articles in Physical Sciences and Mathematics

Topographic Control Of Asynchronous Glacial Advances: A Case Study From Annapurna, Nepal, Beth Pratt-Sitaula, Douglas W. Burbank, Arjun M. Heimsath, Neil F. Humphrey, Michael Oskin, Jaakko Putkonen Dec 2011

Topographic Control Of Asynchronous Glacial Advances: A Case Study From Annapurna, Nepal, Beth Pratt-Sitaula, Douglas W. Burbank, Arjun M. Heimsath, Neil F. Humphrey, Michael Oskin, Jaakko Putkonen

All Faculty Scholarship for the College of the Sciences

Differences in the timing of glacial advances, which are commonly attributed to climatic changes, can be due to variations in valley topography. Cosmogenic 10Be dates from 24 glacial moraine boulders in 5 valleys define two age populations, late-glacial and early Holocene. Moraine ages correlate with paleoglacier valley hypsometries. Moraines in valleys with lower maximum altitudes date to the lateglacial, whereas those in valleys with higher maximum altitudes are early Holocene. Two valleys with similar equilibrium-line altitudes (ELAs), but contrasting ages, are < 5 km apart and share the same aspect, such that spatial differences in climate can be excluded. A glacial mass-balance cellular automata model of these two neighboring valleys predicts that change from a cooler-drier to warmer-wetter climate (as at the Holocene onset) would lead to the glacier in the higher altitude catchment advancing, while the lower one retreats or disappears, even though the ELA only shifted by ~120 m.


Collisional Reactivation Of Rift Margin Fracture Zones, Taiwan And The Taconic Allochthon, David C. Mirakian Dec 2011

Collisional Reactivation Of Rift Margin Fracture Zones, Taiwan And The Taconic Allochthon, David C. Mirakian

Master's Theses

Chapter I. Transverse Topographic Development due to the Reactivation of a Partially-Subducted Fracture Zone: The Southwest Hsüehshan Range, Central Taiwan

Abstract — The southwest flank of the Hsüehshan Range is defined by a topographic break which cuts across regionally mapped structures in central Taiwan. The mountain front trends ~345°, slightly oblique to the Sanyi-Puli seismic zone which has been previously interpreted as a reactivated continental margin fracture zone. Structural data collected along the length of the topographic break reveal two populations of cross-cutting faults with distinct fault-zone materials and a series of southwest-plunging folds. Paleostress axes were reconstructed using the …


Mineralogy And Geochemistry Of Anorogenic Granitic Miarolitic Pegmatites Associated With The White Mountain Intrusive Suite, New Hampshire, Kristen F. Camp Dec 2011

Mineralogy And Geochemistry Of Anorogenic Granitic Miarolitic Pegmatites Associated With The White Mountain Intrusive Suite, New Hampshire, Kristen F. Camp

University of New Orleans Theses and Dissertations

Subvolcanically emplaced granitic, miarolitic pegmatites associated with the White Mountain Igneous Province (WMIP), New Hampshire, were sampled and analyzed using modern analytical techniques including X-ray fluorescence, electron microprobe, scanning electron microscopy, and direct-coupled plasma spectrophotometry. Analytical results suggest that all the sampled miarolitic pegmatites from this study are petrogenetically related to the same intrusive suite, the WMIP. Based on the geochemical data, all the samples formed in an anorogenic tectonic setting and are rift-related. They are classified as NYF-type and plot in the “within plate granite” field on tectonic discrimination diagrams. The majority of the samples are peraluminous, A1 …


Understanding Uplift Of The Ethiopian Plateau From Longitudinal Profile Analysis Of The Blue Nile Drainage System, Prabhat Chandra Neupane Dec 2011

Understanding Uplift Of The Ethiopian Plateau From Longitudinal Profile Analysis Of The Blue Nile Drainage System, Prabhat Chandra Neupane

University of New Orleans Theses and Dissertations

The Ethiopian Plateau is one of the few tectonically-active regions on Earth that is situated in continental rift zones. About 1.6 km deep gorge of the Nile was carved by the Blue Nile River on the Ethiopian Plateau, as the plateau has been experiencing continuous uplift and exhumation in the Cenozoic. Here, we used quantitative analysis of longitudinal rive-profile forms and parameters (knickpoint and normalized steepness-index ksn) of the Blue Nile tributaries to tease out regional tectonic signals.

244 knickpoints were examined in the tributaries, majority (>80%) of which are unassociated with lithology or geological structures. Knickpoint …


Exchange Flows In An Urban Water Body: Bayou St. John Responses To The Removal Of Flood Control Structures, Future Water Elevation Control, And Water Quality, Robin L. Schroeder Dec 2011

Exchange Flows In An Urban Water Body: Bayou St. John Responses To The Removal Of Flood Control Structures, Future Water Elevation Control, And Water Quality, Robin L. Schroeder

University of New Orleans Theses and Dissertations

Bayou St. John, an urban water body extending south from Lake Pontchartrain, has two anthropogenic structures that regulate flow from the Lake . The City of New Orleans has plans to remove the inner control structure to improve water quality. Field and numerical methods used in this study show removing this structure increased water elevations throughout the Bayou but resulted in lower water elevation signal amplitudes that caused a lower tidal flow exchange from north to south. Bulk Richardson numbers showed mixing was inversely related to flow and the Bayou generally remains stratified. Resuspension of contaminated sediment could negatively impact …


Evaluation Of Pgaa Data For Provenance Of Lithic Artifacts, Otis N. Crandell Dec 2011

Evaluation Of Pgaa Data For Provenance Of Lithic Artifacts, Otis N. Crandell

Studia UBB Geologia

The objectives of the study were to determine whether Prompt Gamma Activation Analyses (PGAA) could be successfully used to trace the source(s) of various Neolithic artifacts made of microcrystaline quartz. Two macroscopically identical sources of jasper from central and western Romania were analyzed by PGAA along with five Neolithic artifacts from the Limba site (Alba County). Due to the limited number of trace elements, which can be measured by PGAA, this method when used alone might produce inconclusive results for discriminating between jaspers from different sources. The interpretation of the data may be used for general assessments of provenance involving …


Quantitative Field Testing Rotylenchulus Reniformis Dna From Metagenomic Samples Isolated Directly From Soil., Kurt Showmaker, Gary W. Lawrence, Shien Lu, Clarissa Balbalian, Vincent P. Klink Dec 2011

Quantitative Field Testing Rotylenchulus Reniformis Dna From Metagenomic Samples Isolated Directly From Soil., Kurt Showmaker, Gary W. Lawrence, Shien Lu, Clarissa Balbalian, Vincent P. Klink

College of Agriculture & Life Sciences Publications and Scholarship

A quantitative PCR procedure targeting the ?-tubulin gene determined the number of Rotylenchulus reniformis Linford & Oliveira 1940 in metagenomic DNA samples isolated from soil. Of note, this outcome was in the presence of other soil-dwelling plant parasitic nematodes including its sister genus Helicotylenchus Steiner, 1945. The methodology provides a framework for molecular diagnostics of nematodes from metagenomic DNA isolated directly from soil.


3-D Transient Hydraulic Tomography In Unconfined Aquifers With Fast Drainage Response, Michael Cardiff, Warren Barrash Dec 2011

3-D Transient Hydraulic Tomography In Unconfined Aquifers With Fast Drainage Response, Michael Cardiff, Warren Barrash

CGISS Publications and Presentations

We investigate, through numerical experiments, the viability of three-dimensional transient hydraulic tomography (3DTHT) for identifying the spatial distribution of groundwater flow parameters (primarily, hydraulic conductivity K) in permeable, unconfined aquifers. To invert the large amount of transient data collected from 3DTHT surveys, we utilize an iterative geostatistical inversion strategy in which outer iterations progressively increase the number of data points fitted and inner iterations solve the quasi-linear geostatistical formulas of Kitanidis. In order to base our numerical experiments around realistic scenarios, we utilize pumping rates, geometries, and test lengths similar to those attainable during 3DTHT field campaigns performed at …


Hydrological Parameter Estimations From A Conservative Tracer Test With Variable-Density Effects At The Boise Hydrogeophysical Research Site, B. Dafflon, Warren Barrash, Michael Cardiff, T. C. Johnson Dec 2011

Hydrological Parameter Estimations From A Conservative Tracer Test With Variable-Density Effects At The Boise Hydrogeophysical Research Site, B. Dafflon, Warren Barrash, Michael Cardiff, T. C. Johnson

CGISS Publications and Presentations

Reliable predictions of groundwater flow and solute transport require an estimation of the detailed distribution of the parameters (e.g., hydraulic conductivity, effective porosity) controlling these processes. However, such parameters are difficult to estimate because of the inaccessibility and complexity of the subsurface. In this regard, developments in parameter estimation techniques and investigations of field experiments are still challenging and necessary to improve our understanding and the prediction of hydrological processes. Here we analyze a conservative tracer test conducted at the Boise Hydrogeophysical Research Site in 2001 in a heterogeneous unconfined fluvial aquifer. Some relevant characteristics of this test include: variable-density …


Thermal Plume Transport From Sand And Gravel Pits Potential Thermal Impacts On Cool-Water Streams, Jeffrey M. Markle Dec 2011

Thermal Plume Transport From Sand And Gravel Pits Potential Thermal Impacts On Cool-Water Streams, Jeffrey M. Markle

Electronic Thesis and Dissertation Repository

Potential thermal impacts from below-water-table aggregate extraction on a cool-water stream were investigated by monitoring thermal plumes, moving through an unconfined glacial-outwash aquifer, and assessing their subsurface persistence. The growing demand for aggregate and increased pressure to pursue extraction in ecologically sensitive areas has driven the need for this work. During a 10-year period, ground and surface water temperatures were measured monthly, including two periods of intensive monitoring (22 months and 2.5 years). The aquifer hydraulic conductivity (K) is quantified at the laboratory and field scale. The mean K’s from the multi-scale tests depend on test-support volume and …


Paleomagnetic Constraints On Deformation Of Superfast-Spread Oceanic Crust Exposed At Pito Deep Rift, Andrew J. Horst, R. J. Varga, J. S. Gee, J. A. Karson Dec 2011

Paleomagnetic Constraints On Deformation Of Superfast-Spread Oceanic Crust Exposed At Pito Deep Rift, Andrew J. Horst, R. J. Varga, J. S. Gee, J. A. Karson

Natural Resources and Earth Sciences Faculty Research

The uppermost oceanic crust produced at the superfast spreading (∼142 km Ma −1, full‐spreading rate) southern East Pacific Rise (EPR) during the Gauss Chron is exposed in a tectonic window along the northeastern wall of the Pito Deep Rift. Paleomagnetic analysis of fully oriented dike (62) and gabbro (5) samples from two adjacent study areas yield bootstrapped mean remanence directions of 38.9° ± 8.1°, −16.7° ± 15.6°, n = 23 (Area A) and 30.4° ± 8.0°, −25.1° ± 12.9°, n = 44 (Area B), both are significantly distinct from the Geocentric Axial Dipole expected direction at 23° S. Regional tectonics …


Rock Magnetism Of Hematitic "Bombs" From The Araguainha Impact Structure, Brazil, Luigi Jovane, Elder Yokoyama, Takele Seda, Russ F. Burmester, Ricardo I.F. Trindade, Bernard A. Housen Dec 2011

Rock Magnetism Of Hematitic "Bombs" From The Araguainha Impact Structure, Brazil, Luigi Jovane, Elder Yokoyama, Takele Seda, Russ F. Burmester, Ricardo I.F. Trindade, Bernard A. Housen

Geology Faculty Publications

Hematite impact “bombs” are one of the most striking (and enigmatic) features of the large Araguainha impact structure in central Brazil. They have both porous or massive textures, elongated shapes from 5 to 50 cm in diameter, and botryoidal textures that suggest hydrothermal origin. Some authors have considered these objects as a possible analog of hematite nodules found in Mars, and consequently related to a hydrothermal system. Here we report rock magnetic measurements, X-ray diffraction and Mössbauer spectra for both massive and porous samples for a detailed description of the hematite. Room temperature magnetic measurements, including hysteresis loops, back-field and …


An Integrated Geophysical And Geologic Study Of The Paleogene-Age Volcanic Body And Possible Landslide Deposit On The South Slope Of The Traverse Mountains, Utah, John C. Hoopes Dec 2011

An Integrated Geophysical And Geologic Study Of The Paleogene-Age Volcanic Body And Possible Landslide Deposit On The South Slope Of The Traverse Mountains, Utah, John C. Hoopes

Theses and Dissertations

Development of homes, roads, and commercial buildings in northern Utah has grown significantly during the last several decades. Construction has expanded from the valley floor to higher elevations of benches, foothills, and other elevated regions of the Wasatch Mountain Front. Construction in the higher elevation areas are a concern due to potential for landslides, both new and reactivated. Landslides have been identified in this region and are dated as Pleistocene to historical in age. A possible landslide of about 0.5 km2 on the south slope of Traverse Mountain has been mapped by the Utah Geological Survey in 2005. Its surface …


Quantification Of Glacier Melt Volume In The Indus River Watershed, Maria Nicole Asay Dec 2011

Quantification Of Glacier Melt Volume In The Indus River Watershed, Maria Nicole Asay

Theses and Dissertations

Quantifying the contribution of glaciers to water resources is particularly important in locations where glaciers may provide a large percentage of total river discharge. In some remote locations, direct field measurements of melt rates are difficult to acquire, so alternate approaches are needed. Positive degree-day modeling (PDD) of glacier melt is a valuable tool to making first order approximations of the volume of melt coming from glaciers. In this study, a PDD-melt model is applied to glaciers in the Indus River watershed located in Afghanistan, China, India, and Pakistan. Here, millions of people rely on the water from the Indus …


Remote Analysis Of Grain Size Characteristic In Submarine Pyroclastic Deposits From Kolumbo Volcano, Greece, Clara Smart, D. P. Whitesell, Christopher N. Roman, Steven Carey Dec 2011

Remote Analysis Of Grain Size Characteristic In Submarine Pyroclastic Deposits From Kolumbo Volcano, Greece, Clara Smart, D. P. Whitesell, Christopher N. Roman, Steven Carey

Graduate School of Oceanography Faculty Publications

Grain size characteristics of pyroclastic deposits provide valuable information about source eruption energetics and depositional processes. Maximum size and sorting are often used to discriminate between fallout and sediment gravity flow processes during explosive eruptions. In the submarine environment the collection of such data in thick pyroclastic sequences is extremely challenging and potentially time consuming. A method has been developed to extract grain size information from stereo images collected by a remotely operated vehicle (ROV). In the summer of 2010 the ROV Hercules collected a suite of stereo images from a thick pumice sequence in the caldera walls of Kolumbo …


Investigating The Impact Of Restricted Irrigation Practices On Soil Moisture Variability And Distribution In A Dry Farmed Vineyard Site, Boise, Idaho, J. Duffin, David Wilkins, J. Guenther Dec 2011

Investigating The Impact Of Restricted Irrigation Practices On Soil Moisture Variability And Distribution In A Dry Farmed Vineyard Site, Boise, Idaho, J. Duffin, David Wilkins, J. Guenther

David E. Wilkins

Changing climate in semiarid regions may result in increased water stresses for agricultural production as timing and form of precipitation may result in diminished surface water for irrigation. To prepare for these changing conditions, studies are being conducted on the possibility of dry farmed agriculture as an alternative to irrigated production. This study specifically investigates the ability to grow productive wine grapes with limited or zero irrigation in the Boise Front Foothills, West Foothills TIC Vineyard, located in a climate zone receiving less than 300 mm of annual precipitation. Traditional vineyard performance factors such as planting densities, soil type, rootstock, …


Sophomore Field Experiences As An Introduction To The Nature Of Geosciences: Data Collection And Analysis Using Dendrochronology, David Wilkins, M. Kunkel Dec 2011

Sophomore Field Experiences As An Introduction To The Nature Of Geosciences: Data Collection And Analysis Using Dendrochronology, David Wilkins, M. Kunkel

David E. Wilkins

Opportunities for field experiences are often presented as a primary reason that undergraduate students gravitate towards geosciences as a major field of study. What those students may not understand is that, for professional geoscientists, field experiences go beyond the freshman-level field trip, and students may overlook the processes of observation, data collection and analysis that are inherent to the science. The Department of Geosciences at Boise State has developed a set of sophomore field experience courses designed to "set the hook" into new majors and prepare them for field experiences in upper division coursework. These sophomore courses have been shown …


Remote Analysis Of Grain Size Characteristic In Submarine Pyroclastic Deposits From Kolumbo Volcano, Greece, C. Smart, D. P. Whitesell, C. Roman, S. Carey Dec 2011

Remote Analysis Of Grain Size Characteristic In Submarine Pyroclastic Deposits From Kolumbo Volcano, Greece, C. Smart, D. P. Whitesell, C. Roman, S. Carey

Christopher N. Roman

Grain size characteristics of pyroclastic deposits provide valuable information about source eruption energetics and depositional processes. Maximum size and sorting are often used to discriminate between fallout and sediment gravity flow processes during explosive eruptions. In the submarine environment the collection of such data in thick pyroclastic sequences is extremely challenging and potentially time consuming. A method has been developed to extract grain size information from stereo images collected by a remotely operated vehicle (ROV). In the summer of 2010 the ROV Hercules collected a suite of stereo images from a thick pumice sequence in the caldera walls of Kolumbo …


Whole-Rock Lead-Lead Systematics And Major Element Analyses On The 1.85 Ga. Flin Flon Paleosol, Manitoba, Canada: Implications For Uranium Mobility., Federico Arturo Valencia Dec 2011

Whole-Rock Lead-Lead Systematics And Major Element Analyses On The 1.85 Ga. Flin Flon Paleosol, Manitoba, Canada: Implications For Uranium Mobility., Federico Arturo Valencia

Geosciences Theses

The 1.85 Ga Flin Flon paleosol located in Flin Flon, Manitoba, Canada, is studied with the purpose of determining the timing and geochemical trend of uranium migration. Radiometric minimum ages of sediments and paleosols indicates the presence of a post-depositional event, these ages are bracketed by the Trans-Hudson orogeny event (2155–1750 Ma) which resulted in the alteration of κ(Th/U) and µ(U/Pb) ratios by exposing volcanics to the atmosphere and instigating the mobilization of U. The profile shows that the Missi sediments lost Uby 84% average relative to corrected average upper crust value. The upper paleosol gained U by 11% and …


Erasing Boundaries: Global Resource Sharing In The 21st Century, Robert A. Seal Dec 2011

Erasing Boundaries: Global Resource Sharing In The 21st Century, Robert A. Seal

Robert A Seal

Academic libraries have long been accustomed to participating in cooperative ventures with neighboring institutions as well as with those in other regions of their country. In large part, such activities have grown out of a desire to reduce or control costs, as well as to provide users with a broader base of materials for research, study, and teaching. Because not even a well-developed national library is able to fulfill all its users' needs all the time, today's university libraries must depend upon one another to fulfill those needs. For many decades, the resource sharing tradition has been particularly strong among …


Dendroclimatology And Woodland Dynamics On The Volcanic Badlands Of Western New Mexico, U.S.A., Mark Daniel Spond Dec 2011

Dendroclimatology And Woodland Dynamics On The Volcanic Badlands Of Western New Mexico, U.S.A., Mark Daniel Spond

Doctoral Dissertations

My dissertation research addressed woodland dynamics and dendroclimatology on the volcanic badlands of western New Mexico. The research was intended to complement previous studies by: (1) assessing vegetation structure and composition dynamics at El Malpais National Monument between 1948–2010 using repeat photography; (2) improving knowledge of the influence of climate and land use on vegetation dynamics at El Malpais National Monument; (3) providing a unique tree-ring data set from Rocky Mountain juniper growing on the malpais; (4) elucidating relationships between Pacific teleconnections and radial growth in Rocky Mountain juniper; and (5) improving understanding of the dynamic nature of climate in …


Experimental Investigations Of Fluid–Mineral Interactions In Olivine And Dolomite, Michael Thomas Deangelis Dec 2011

Experimental Investigations Of Fluid–Mineral Interactions In Olivine And Dolomite, Michael Thomas Deangelis

Doctoral Dissertations

Geochemical processes involving the interaction of fluids and minerals occur in nearly every environment on the surface and in the crust of the Earth. The variety of fluid–mineral processes on the Earth is quite diverse, and these various processes can occur under a large range of geochemical conditions. Aqueous dissolution and alteration, hydration, protonation, solution–precipitation, diffusion, and fluid and isotope exchange are among the many fluid–mineral interaction processes that contribute to the overall cycling of elements on Earth. This dissertation uses analog experiments to examine fluid­–mineral interaction processes found in different geological environments and under a range of environmental conditions. …


Vulnerability Of High Latitude Soil Organic Carbon In North America To Disturbance, Guido Grosse, Jennifer Harden, Merritt Turetsky, David A. Mcguire, Philip Camill, Charles Tarnocai, Steve Frolking, Edward A.G. Schuur, Torre Jorgenson, Sergei Marchenko, Vladimir Romanovsky, Kimberly P. Wickland, Nancy H. F. French, Mark Waldrop, Laura Bourgeau-Chavez, Robert G. Striegl Dec 2011

Vulnerability Of High Latitude Soil Organic Carbon In North America To Disturbance, Guido Grosse, Jennifer Harden, Merritt Turetsky, David A. Mcguire, Philip Camill, Charles Tarnocai, Steve Frolking, Edward A.G. Schuur, Torre Jorgenson, Sergei Marchenko, Vladimir Romanovsky, Kimberly P. Wickland, Nancy H. F. French, Mark Waldrop, Laura Bourgeau-Chavez, Robert G. Striegl

Michigan Tech Research Institute Publications

This synthesis addresses the vulnerability of the North American high-latitude soil organic carbon (SOC) pool to climate change. Disturbances caused by climate warming in arctic, subarctic, and boreal environments can result in significant redistribution of C among major reservoirs with potential global impacts. We divide the current northern high-latitude SOC pools into (1) near-surface soils where SOC is affected by seasonal freeze-thaw processes and changes in moisture status, and (2) deeper permafrost and peatland strata down to several tens of meters depth where SOC is usually not affected by short-term changes. We address key factors (permafrost, vegetation, hydrology, paleoenvironmental history) …


Groundwater Chemistry Of The Weaber Plain: Preliminary Results, Adam Lillicrap, Paul Raper, Richard J. George Dr, D L. Bennett Dec 2011

Groundwater Chemistry Of The Weaber Plain: Preliminary Results, Adam Lillicrap, Paul Raper, Richard J. George Dr, D L. Bennett

Resource management technical reports

In 2008, the Ord Irrigation Expansion Project was approved by the Western Australian Government to develop irrigated agriculture on the Weaber Plain. Construction of the M2 supply channel connecting the ORIA and the Weaber Plain, and the final period of irrigation design, environmental management and related approval processes, commenced later in 2009. This process followed a protracted period of public and private industry planning and environmental assessment (Kinhill 2000). This report summarises an analysis of groundwater salinity trends on the Ivanhoe and Weaber plains and the preliminary results of an intensive water-quality sampling program carried out in 2010 as part …


Surface Water Characteristics Of The Weaber Plain And Lower Keep River Catchments: Data Review And Preliminary Results, D L. Bennett, Richard J. George Dr Dec 2011

Surface Water Characteristics Of The Weaber Plain And Lower Keep River Catchments: Data Review And Preliminary Results, D L. Bennett, Richard J. George Dr

Resource management technical reports

In 2008, the Ord Irrigation Expansion Project was approved by the Western Australian Government to develop irrigated agriculture on the Weaber Plain.

An important concern is the effect the Weaber Plain agricultural development may have on the water quality of the downstream Border Creek and Keep River

This report assembles and reviews all available physico-chemical water quality data for the lower Keep River and Border Creek systems and presents data from the initial year of a targeted baseline monitoring program (June 2010 – June 2013).


The Use Of Tilt Angle In Gravity And Magnetic Methods, Uğur Akin, Betül Işikdeni̇z Şeri̇foğlu, Mehmet Duru Dec 2011

The Use Of Tilt Angle In Gravity And Magnetic Methods, Uğur Akin, Betül Işikdeni̇z Şeri̇foğlu, Mehmet Duru

Bulletin of the Mineral Research and Exploration

Tilt angle method, which has been recently used in investigating the boundaries of structures, reveals useful information on deep and shallow structures. Tilt angle is expressed as the arctan value of the ratio of the vertical derivative of the potential field to its horizontal derivative. The method was applied to Kýrþehir-Ý31 Sheet. As a result, the presence of volcanites buried under terrestrial sediments was demonstrated.


Environmental Impact Of The Three Kids Mine Tailings, Henderson, Nv, Ji Hye Park Dec 2011

Environmental Impact Of The Three Kids Mine Tailings, Henderson, Nv, Ji Hye Park

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research focused on the distribution of the Three Kids Mine tailings in surface soils in and around the mine in Henderson, Nevada. It is situated next to the communities of Calico Ridge and Lake Las Vegas Resort, and, just the west of the Lake Mead Recreation area. Even though the mine has been inactive for almost 50 years (1917-1961), tailing piles and other sources of contamination on the mine are currently exposed to the atmosphere. In this study, surface soil samples were collected along eight transects emanating from the center of Three Kids Mine tailing piles up to five …


Three-Dimensionally Preserved Integument Reveals Hydrodynamic Adaptations In The Extinct Marine Lizard Ectenosaurus (Reptilia, Mosasauridae), Johan Lindgren, Michael J. Everhart, Michael W. Caldwell Dec 2011

Three-Dimensionally Preserved Integument Reveals Hydrodynamic Adaptations In The Extinct Marine Lizard Ectenosaurus (Reptilia, Mosasauridae), Johan Lindgren, Michael J. Everhart, Michael W. Caldwell

Sternberg Museum of Natural History Faculty Publications

The physical properties of water and the environment it presents to its inhabitants provide stringent constraints and selection pressures affecting aquatic adaptation and evolution. Mosasaurs (a group of secondarily aquatic reptiles that occupied a broad array of predatory niches in the Cretaceous marine ecosystems about 98-65 million years ago) have traditionally been considered as anguilliform locomotors capable only of generating short bursts of speed during brief ambush pursuits. Here we report on an exceptionally preserved, long-snouted mosasaur (Ectenosaurus clidastoides) from the Santonian (Upper Cretaceous) part of the Smoky Hill Chalk Member of the Niobrara Formation in western Kansas, USA, that …


Atlantic Multidecadal Oscillation-Forced Regional Summertime Precipitation Variations In The Central United States, Michael C. Veres Dec 2011

Atlantic Multidecadal Oscillation-Forced Regional Summertime Precipitation Variations In The Central United States, Michael C. Veres

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

The purpose of this research is to identify the regional mechanisms by which the Atlantic Multidecadal Oscillation (AMO) influences summer (June-August) precipitation in the central U.S. This was accomplished by running two different sets of simulations using the Weather Research and Forecasting (WRF) regional climate model, one forced by observations and the other forced only by variations in the AMO as obtained via a global climate model (GCM). The results reveal a complex set of mechanisms active in the lower and middle troposphere by which the AMO influences summer circulation and precipitation in the central U.S. During the cold phase …


High-Resolution Study Of Layering Within The Percolation And Soaked Facies Of The Greenland Ice Sheet, Joel Brown, Joel T. Harper, W. Tad Pfeffer, Neil Humphrey, John H. Bradford Dec 2011

High-Resolution Study Of Layering Within The Percolation And Soaked Facies Of The Greenland Ice Sheet, Joel Brown, Joel T. Harper, W. Tad Pfeffer, Neil Humphrey, John H. Bradford

Geosciences Faculty Publications

Within the percolation and soaked facies of the Greenland ice sheet, the relationship between radar-derived internal reflection horizons and the layered structure of the firm column is unclear. We conducted two small-scale ground-penetrating radar (GPR) surveys in conjunction with 10 m firm cores that we colleced within the percolation and soaked facies of the Greenland ice sheet. The two surveys were separated by the distance of about 50 km and about 340 m of elevation leading to about 40 days of difference in the duration of average annual melt. At the higher site (about 1997 ma.s.l.), which receives less melt, …