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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.


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 …


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 …


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 …


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) …


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, …


Assessment Of Corrosion Potential Of Coarse Backfill Aggregates For Mechanically Stabilized Earth Walls, Anita Thapalia, David M. Borrok, Soheil Nazarian, Jose Garibay Dec 2011

Assessment Of Corrosion Potential Of Coarse Backfill Aggregates For Mechanically Stabilized Earth Walls, Anita Thapalia, David M. Borrok, Soheil Nazarian, Jose Garibay

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The service life of mechanically stabilized earth walls depends on the rate of corrosion of the metallic reinforcements used in their construction. The assessment of corrosion potential requires an accurate evaluation of pH, resistivity, and sulfate and chloride concentrations of aqueous solutions in contact with the surrounding aggregate. Highway agencies tend to use larger aggregates that contain only a small amount of fine material (passing the Number 40 sieve) in the backfill. Evaluation of the electrochemical parameters of coarse aggregates is challenging because traditional evaluation methods call for the use of fine material. In this study, the suitability of traditional …


Co2 Sequestration In Basalt: Carbonate Mineralization And Fluid Substitution, Thomas L. Otheim, Ludmila Adam, Kasper Van Wijk, Michael L. Batzle, Travis Mcling, Robert Podgorney Dec 2011

Co2 Sequestration In Basalt: Carbonate Mineralization And Fluid Substitution, Thomas L. Otheim, Ludmila Adam, Kasper Van Wijk, Michael L. Batzle, Travis Mcling, Robert Podgorney

CGISS Publications and Presentations

Geologicalsequestration of carbon dioxide in deep reservoirs may provide alarge-scale option for reducing the emissions of this gas intothe atmosphere. The effectiveness of sequestration depends on the storagecapacity and stability of the reservoir and risk of leakageinto the overburden. Reservoir rocks can react with a CO2-watermixture, potentially resulting in the precipitation of minerals in theavailable matrix pore space and within pre-existing fractures. This inducedmineralization may form internal seals that could help mitigate theleakage of CO2 into the overburden. For basaltic host rocks,carbonic acid partially dissolves minerals in the host rock, suchas the calcium plagioclase mineral, freeing various …


Assessing Flood Inundation Mapping With The Use Of A Dem And Gis Along The Missouri River At Sioux City, Iowa, Kathryn A. Pfaffle Dec 2011

Assessing Flood Inundation Mapping With The Use Of A Dem And Gis Along The Missouri River At Sioux City, Iowa, Kathryn A. Pfaffle

Department of Environmental Studies: Undergraduate Student Theses

There are various methods that are used to predict flood inundation. The U.S. Army Corps of Engineers provided inundation maps for the 2011 Missouri River flood event that did not utilized aerial photo imagery. This study assesses the suitability of using a digital elevation model (DEM) in combination with aerial photo imagery within a geographic information system to predict flood inundation mapping along the Missouri River in Sioux City, Iowa. GPS data was collected during the height of this flood event in order to validate the positional accuracy of the DEM. Using the GPS receiver’s accuracy standards to determine the …


Spring Migration Of Mallards From Arkansas As Determined By Satellite Telemetry, David George Krementz, Kwasi Asante, Luke W. Naylor Dec 2011

Spring Migration Of Mallards From Arkansas As Determined By Satellite Telemetry, David George Krementz, Kwasi Asante, Luke W. Naylor

United States Geological Survey: Staff Publications

We used satellite telemetry to document spring migration phenology, routes, stopover regions, and nesting sites of mallards Anas platyrhynchos marked in Arkansas during the winters of 2004–2007. Of the 143 marked mallards that migrated from Arkansas, they did so, on average, by mid-March. Mallards flew over the Missouri Ozarks and 42% made an initial stopover in Missouri, where they used areas that had larger rivers (Mississippi River, Missouri River) embedded in an agricultural landscape. From this stopover region they either migrated directly to the Prairie Pothole Region (PPR) or they migrated north to Minnesota where they either moved next to …


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).


Land Systems Of The Kimberley Region, Western Australia, A L. Payne, N Schoknecht Dec 2011

Land Systems Of The Kimberley Region, Western Australia, A L. Payne, N Schoknecht

Technical Bulletins

The Land Systems of the Kimberley Region Report describes and maps the landscapes, soils and vegetation of the Kimberley region. This report is a consolidation of surveys carried out by different organisations, across different areas of the Kimberley, since the 1940s. The Kimberley region, as defined in this bulletin, covers 330 070km². The report categorises the Kimberley region into 111 land systems. Under each land system, the report identifies the vulnerabilities of those areas, and provides recommendations on how to achieve sustainable use. The report also publishes pasture types for the entire region and the grazing potential for each pasture, …


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 …


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 …


Surfactant Induced Reservoir Wettability Alteration: Recent Theoretical And Experimental Advances In Enhanced Oil Recovery, Yefei Wang, Huaimin Xu, Weizhao Yu, Baojun Bai, Xinwang Song, Jichao Zhang Dec 2011

Surfactant Induced Reservoir Wettability Alteration: Recent Theoretical And Experimental Advances In Enhanced Oil Recovery, Yefei Wang, Huaimin Xu, Weizhao Yu, Baojun Bai, Xinwang Song, Jichao Zhang

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Reservoir wettability plays an important role in various oil recovery processes. The origin and evolution of reservoir wettability were critically reviewed to better understand the complexity of wettability due to interactions in crude oil-brine-rock system, with introduction of different wetting states and their influence on fluid distribution in pore spaces. The effect of wettability on oil recovery of waterflooding was then summarized from past and recent research to emphasize the importance of wettability in oil displacement by brine. The mechanism of wettability alteration by different surfactants in both carbonate and sandstone reservoirs was analyzed, concerning their distinct surface chemistry, and …


Multiple Storm Event Impacts On Epikarst Storage And Transport Of Organic Soil Amendments In South-Central Kentucky, Sean M. Vanderhoff Dec 2011

Multiple Storm Event Impacts On Epikarst Storage And Transport Of Organic Soil Amendments In South-Central Kentucky, Sean M. Vanderhoff

Masters Theses & Specialist Projects

The groundwater in agricultural karst areas is susceptible to contamination from organic soil amendments and pesticides. During major storm events during 2011, dye traces were initiated using sulphorhodamine-B, fluorescein and eosine in a groundwater recharge area where manure was applied to the ground. Fecal coliform samples were collected from significant storm events from January-September 2011. Water samples and geochemical data were collected every four hours before, during, and between the storm events from a waterfall in Crumps cave flowing from the known recharge area to track the transport and residence time of the epikarst water and organic soil amendments during …


A Comprehensive Method For Fractionating Soil Organic Matter Not Protected And Protected From Decomposition By Physical And Chemical Mechanisms, César Plaza, José M. Fernández, Engil Isadora Pujol Pereira, Alfredo Polo Nov 2011

A Comprehensive Method For Fractionating Soil Organic Matter Not Protected And Protected From Decomposition By Physical And Chemical Mechanisms, César Plaza, José M. Fernández, Engil Isadora Pujol Pereira, Alfredo Polo

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

The objective of this work was to describe a method for isolating meaningful and measurable soil organic matter (SOM) pools that differ in the mechanisms by which they are protected from decomposition. The proposed method is appropriate for soil C stabilization and sequestration studies. Unlike previous fractionation schemes, this procedure allows free SOM located between aggregates (unprotected C pool) and SOM occluded within both macroaggregates and microaggregates (C weakly and strongly protected by physical mechanisms, respectively) to be recovered separately, freed from the soil mineral matrix and the mineral-associated SOM pool (C pool protected by chemical mechanisms) and thus well …


Stratigraphic Record Of Holocene Coseismic Subsidence, Padang, West Sumatra, Tina Dura, Charles M. Rubin, Harvey M. Kelsey, Benjamin P. Horton, Andrea Hawkes, Christopher H. Vane, Mudrik Daryono, Candace Grand Pre, Tyler Landinsky, Sarah Bradley Nov 2011

Stratigraphic Record Of Holocene Coseismic Subsidence, Padang, West Sumatra, Tina Dura, Charles M. Rubin, Harvey M. Kelsey, Benjamin P. Horton, Andrea Hawkes, Christopher H. Vane, Mudrik Daryono, Candace Grand Pre, Tyler Landinsky, Sarah Bradley

All Faculty Scholarship for the College of the Sciences

Stratigraphic evidence is found for two coseismic subsidence events that underlie a floodplain 20 km south of Padang, West Sumatra along the Mentawai segment (0.5°S–0.3°S) of the Sunda subduction zone. Each earthquake is marked by a sharp soil‐mud contact that represents a sudden change from mangrove to tidal flat. The earthquakes occurred about 4000 and 3000 cal years B.P. based on radiocarbon ages of detrital plant fragments and seeds. The absence of younger paleoseismic evidence suggests that late Holocene relative sea level fall left the floodplain too high for an earthquake to lower it into the intertidal zone. Our results …


Does Gender Bias Influence Awards Given By Societies?, Mary Anne Holmes, Pranoti Asher, John Farrington, Rana Fine, Margaret S. Leinen, Phoebe Leboy Nov 2011

Does Gender Bias Influence Awards Given By Societies?, Mary Anne Holmes, Pranoti Asher, John Farrington, Rana Fine, Margaret S. Leinen, Phoebe Leboy

Department of Earth and Atmospheric Sciences: Faculty Publications

AGU is a participant in a U.S. National Science Foundation (NSF)–funded project called Advancing Ways of Awarding Recognition in Disciplinary Societies (AWARDS), which seeks to examine whether gender bias affects selection of recipients of society awards. AGU is interested in learning why there is a higher proportion of female recipients of service and education awards over the past 2 decades. Combined with a lower rate of receipt of research awards, these results suggest that implicit (subconscious) bias in favor of male candidates still influences awardee selection.

Six other professional societies (American Chemical Society, American Mathematical Society, American Society of Anesthesiologists, …


Flow Dynamics Of An Accumulation Basin: A Case Study Of Upper Kahiltna Glacier, Mount Mckinley, Alaska, Seth Campbell, Karl Kreutz, Erich Osterberg, Steven Arcone Nov 2011

Flow Dynamics Of An Accumulation Basin: A Case Study Of Upper Kahiltna Glacier, Mount Mckinley, Alaska, Seth Campbell, Karl Kreutz, Erich Osterberg, Steven Arcone

Dartmouth Scholarship

We interpreted flow dynamics of the Kahiltna Pass Basin accumulation zone on Mount McKinley, Alaska, USA, using 40, 100 and 900 MHz ground-penetrating radar profiles and GPS surface velocity measurements. We found dipping, englacial surface-conformable strata that experienced vertical thickening as the glacier flowed westward from a steep, higher-velocity (60 m a−1) region into flat terrain associated with a 90° bend in the glacier and lower velocities (15 m a−1) to the south. Stratigraphy near the western side of the basin was surface-conformable to ∼170 m depth and thinned as flow diverged southward, down-glacier. We found complex strata beneath the …


Geosciences Newsletter - 2011, Department Of Geosciences Nov 2011

Geosciences Newsletter - 2011, Department Of Geosciences

Geological and Environmental Sciences News

Vol. 5, No. 1

  • Publications
  • MGRRE
  • Field Trips
  • Graduate News
  • Alumni
  • Advisory Board
  • Gifts
  • Grants
  • Alumni Update


Magnetic Susceptibility As A Proxy For Investigating Microbially Mediated Iron Reduction, Farag M. Mewafy, Estella A. Atekwana, D. Dale Werkema, Lee D. Slater, Dimitrios Ntarlagiannis, Andre Revil, Magnus E. Skold, Geoffrey N. Delin Nov 2011

Magnetic Susceptibility As A Proxy For Investigating Microbially Mediated Iron Reduction, Farag M. Mewafy, Estella A. Atekwana, D. Dale Werkema, Lee D. Slater, Dimitrios Ntarlagiannis, Andre Revil, Magnus E. Skold, Geoffrey N. Delin

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

We investigated magnetic susceptibility (MS) variations in hydrocarbon contaminated sediments. Our objective was to determine if MS can be used as an intrinsic bioremediation indicator due to the activity of iron-reducing bacteria. A contaminated and an uncontaminated core were retrieved from a site contaminated with crude oil near Bemidji, Minnesota and subsampled for MS measurements. The contaminated core revealed enriched MS zones within the hydrocarbon smear zone, which is related to iron-reduction coupled to oxidation of hydrocarbon compounds and the vadose zone, which is coincident with a zone of methane depletion suggesting aerobic or anaerobic oxidation of methane is coupled …


Understanding Melt Generation Beneath The Slow-Spreading Kolbeinsey Ridge Using (238)U, (230)Th, And (231)Pa Excesses, Lynne J. Elkins, K.W.W. Sims, J. Prytulak, T. Elliot, N. Mattielli, J. Blichert-Toft, J. Blusztajn, N. Dunbar, C. Devey, D. F. Mertz, J. G. Schilling, M. Murrell Nov 2011

Understanding Melt Generation Beneath The Slow-Spreading Kolbeinsey Ridge Using (238)U, (230)Th, And (231)Pa Excesses, Lynne J. Elkins, K.W.W. Sims, J. Prytulak, T. Elliot, N. Mattielli, J. Blichert-Toft, J. Blusztajn, N. Dunbar, C. Devey, D. F. Mertz, J. G. Schilling, M. Murrell

Geology Faculty Research and Scholarship

To examine the petrogenesis and sources of basalts from the Kolbeinsey Ridge, one of the shallowest locations along the global ridge system, we present new measurements of Nd, Sr, Hf, and Pb isotopes and U-series disequilibria on 32 axial basalts. Young Kolbeinsey basalts (full-spreading rate = 1.8 cm/yr; 67 degrees 05'-70 degrees 26'N) display ((230)Th/(238)U) < 1 and ((230)Th/(238)U) > 1 with ((230)Th/(238)U) from 0.95 to 1.30 and have low U (11.3-65.6 ppb) and Th (33.0 ppb-2.40 ppm) concentrations. Except for characteristic isotopic enrichment near the Jan Mayen region, the otherwise depleted Kolbeinsey basalts (e. g. (87)Sr/(86)Sr = 0.70272-0.70301, epsilon(Nd) = 8.4-10.5, epsilon(Hf) = 15.4-19.6 …


Suspended Sediment Concentration In The Brushy Creek Watershed, Kentucky, Tyler Wade, Walter S. Borowski Nov 2011

Suspended Sediment Concentration In The Brushy Creek Watershed, Kentucky, Tyler Wade, Walter S. Borowski

EKU Faculty and Staff Scholarship

Suspended sediment concentration (SSC) can be used as a proxy for environmental health of stream water. For example, large sediment loads can cause harm to aquatic life and are a mechanism for introducing and transporting fecal microbes. We measure SSC of the Brushy Creek watershed, located in Rockcastle, Pulaski, and Lincoln Counties, where the Eastern Kentucky Environmental Research Institute (EK-ERI) has been conducting an assessment of the watershed. Two auto sampling units were placed in Brushy Creek to collect water samples for determination of SSC. The units collect samples every 14 hours for a two-week period, then samples are retrieved …


Nutrient And Fecal Microbe Assessment Of The Water Quality Of Tates Creek, Madison County, Kentucky, Krisopher H. Carroll, Walter S. Borowski Nov 2011

Nutrient And Fecal Microbe Assessment Of The Water Quality Of Tates Creek, Madison County, Kentucky, Krisopher H. Carroll, Walter S. Borowski

EKU Faculty and Staff Scholarship

Tates Creek is a significant tributary to the Kentucky River that has shown high levels of microbial and nutrient pollution. We sampled the waters of Tates Creek comprehensively by occupying 25 stations along its 13-mile length, collecting stream water at the confluence of major tributaries from its headwaters to the Kentucky River. Samples were collected four times between May and August 2011 during dry periods as well as immediately after rainfall events.

We measured ammonium (NH4+), nitrate (NO3-) and phosphate (PO4-) concentrations using colorimetry. Microbial samples were measured for total coliform …


Stress Modulation On The San Andreas Fault By Interseismic Fault System Interactions, John P. Loveless, Brendan J. Meade Nov 2011

Stress Modulation On The San Andreas Fault By Interseismic Fault System Interactions, John P. Loveless, Brendan J. Meade

Geosciences: Faculty Publications

During the interseismic phase of the earthquake cycle, between large earthquakes, stress on faults evolves in response to elastic strain accumulation driven by tectonic plate motions. Because earthquake cycle processes induce non-local stress changes, the interseismic stress accumulation rate on one fault is influenced by the behavior of all nearby faults. Using a geodetically constrained block model, we show that the total interseismic elastic strain field generated by fault interactions within Southern California may increase stressing rates on the Mojave and San Bernardino sections of the San Andreas fault within the Big Bend region by as much as 38% relative …