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Articles 181 - 210 of 275

Full-Text Articles in Earth Sciences

Climate Change Effects On Vibrio Bacteria In The Winyah Bay Estuary And The Projected Spread Of Vibrio Under Future Climatic Scenarios., Reem Deeb Jan 2013

Climate Change Effects On Vibrio Bacteria In The Winyah Bay Estuary And The Projected Spread Of Vibrio Under Future Climatic Scenarios., Reem Deeb

Theses and Dissertations

While there are several studies on the distribution ofVibrio vulnificusandVibrio parahaemolyticusin estuarine waters around the world, there is little information on the distribution of both organisms in South Carolina waters. Monthly sampling of surface and bottom water from 9 sites in Winyah Bay was conducted over the period April-October 2012. Both organisms were enumerated on CHROMagarVibriomedia. TheVibriocounts obtained were mainly less than 20 Colony Forming Units (CFU)/ml which is typical for what was found elsewhere along the coast of the Carolinas. TheVibrio vulnificuscounts were the highest when salinity ranged between 5 ppt and 20 ppt.Vibrio parahaemolyticusdid not show a clear …


Thermal History Of Nearly Metamict Zircon Of The Taza-Guercif Basin (Morocco) Revealed Using Scanning Electron Microscope High-Density Fission-Track Dating, Tyler Michael Izykowski Jan 2013

Thermal History Of Nearly Metamict Zircon Of The Taza-Guercif Basin (Morocco) Revealed Using Scanning Electron Microscope High-Density Fission-Track Dating, Tyler Michael Izykowski

Theses and Dissertations

Northwest Africa provides unique insight into a wide range of geologic processes throughout a vast portion of Earth's history. Moroccan geology in particular can provide valuable insight, from the formations of West Africa through the Eburnian orogeny (~2000 Ma), Gondwana during the Pan-African orogeny (~900-500 Ma), and Pangaea by means of the Hercynian (Variscan) orogeny (~400-300 Ma), to more recent crustal and climatic events, such as the Messinian salinity crisis (5.96-5.33 Ma). However, the current lack of western literature regarding this region presents a significant obstacle in understanding the aforementioned processes. Herein, I employ a new technique in zircon fission-track …


Tidal Flux Of Trace Metals And Rare Earth Elements In A Barrier Island Salt Marsh, Ryan Antle Jan 2013

Tidal Flux Of Trace Metals And Rare Earth Elements In A Barrier Island Salt Marsh, Ryan Antle

Theses and Dissertations

Barrier island salt marshes are known as sources of nutrients to the coastal ocean but it is unclear whether they are also sources or sinks of trace metals in regards to coastal waters. Salt marshes are characterized by steep redox and biogeochemical gradients, which constantly fluctuate as a result of tidal pumping. While several studies have examined metal budgets between terrestrial fresh water, estuarine subterranean fluids, and coastal saline waters, there is little data regarding fluid chemistry for metals in salt water estuaries in the absence of fresh water input. This study investigated a back barrier salt marsh on Cabretta …


Tectonics Of The South Georgia Rift, David Michael Heffner Jan 2013

Tectonics Of The South Georgia Rift, David Michael Heffner

Theses and Dissertations

Triassic rifting of the supercontinent Pangea left behind numerous basins on what is now the eastern North American margin. The South Georgia Rift (SGR) was thought to be the best preserved of these basins having been capped by thick basalt flows of the Central Atlantic Magmatic Province (CAMP) and later buried beneath the Cretaceous and younger Coastal Plain. Because it is buried beneath the Coastal Plain, the SGR is only known through sparse drilling and geophysical methods. Despite this limited dataset, the SGR is the only one of the eastern North American Triassic basins known to overlie the ancient Alleghanian …


Energy Metrics For State Government Buildings, Trevor Michael Jan 2013

Energy Metrics For State Government Buildings, Trevor Michael

Theses and Dissertations

Measuring true progress towards energy conservation goals requires the accurate reporting and accounting of energy consumption. An accurate energy metrics framework is also a critical element for verifiable Greenhouse Gas Inventories. Energy conservation in government can reduce expenditures on energy costs leaving more funds available for public services. In addition to monetary savings, conserving energy can help to promote energy security, air quality, and a reduction of carbon footprint. With energy consumption/GHG inventories recently produced at the Federal level, state and local governments are beginning to also produce their own energy metrics systems.

In recent years, many states have passed …


Amplitude Vs. Offset Effects On Gas Hydrates At Woolsey Mound, Gulf Of Mexico, Walter R. Anderson Jan 2013

Amplitude Vs. Offset Effects On Gas Hydrates At Woolsey Mound, Gulf Of Mexico, Walter R. Anderson

Theses and Dissertations

Due to the estimated massive quantities of natural methane hydrates, they represent one of the largest sources of future alternative energy on Earth. Methane hydrates have been found in the shallow sub-seafloor of the Northern Gulf of Mexico where the water depth is in excess of ~900 m. Mississippi Canyon Block 118 has been chosen by the Gulf of Mexico Hydrates Research Consortium to be the site of a multi-sensor, multi-discipline sea-floor observatory for gas hydrate research. First evidence for gas hydrates at MC 118 was observed at Woolsey Mound. Subsurface evidence for gas hydrates has subsequently been substantiated by …


The Effects Of Mean Sea Level And Tidal Amplitude On Ground Water Discharge And Pore-Water Salinity Distribution Along A Forest/Marsh Boundary, North Inlet, Sc, John Bradley Peurifoy Jan 2013

The Effects Of Mean Sea Level And Tidal Amplitude On Ground Water Discharge And Pore-Water Salinity Distribution Along A Forest/Marsh Boundary, North Inlet, Sc, John Bradley Peurifoy

Theses and Dissertations

Advective groundwater flow in salt marshes is an important mechanism through which nutrients are exported to adjacent coastal waters. Groundwater flow also influences the distribution of pore-water salinity in the subsurface marsh, which affects botanical zonation, nutrient transport, and primary productivity. Recent idealized marsh island simulations have suggested that increases in tidal amplitude result in increased groundwater discharge, and that the elevation of MWL relative to the marsh platform is inversely related to groundwater discharge. These simulations were only representative of marsh islands (as opposed to forest-marsh boundaries) and relied on simulated tides and MWL position. The results were not …


Subsurface Imaging And Petrophysical Analysis Of The South Georgia Rift Basin, South Carolina, Olusoga Martins Akintunde Jan 2013

Subsurface Imaging And Petrophysical Analysis Of The South Georgia Rift Basin, South Carolina, Olusoga Martins Akintunde

Theses and Dissertations

The Triassic-Jurassic South Georgia Rift (SGR) basin, buried beneath Coastal Plain sediments of southern South Carolina, southeastern Georgia, western Florida, and southern Alabama, consists of an assemblage of continental rift deposits (popularly called red beds), and mafic igneous rocks (basalt flows and diabase sills). The red beds are capped by basalts and/or diabase sills, and constitute the target for supercritical CO2 storage as part of a Department of Energy funded project to study feasibility for safe and long-term sequestration. This study addresses key stratigraphic, structural and petrophysical issues critical to determine subsurface suitability for CO2 storage as well as improved …


Identifying Values And Benefits Of Congaree National Park, Maka Bitsadze Jan 2013

Identifying Values And Benefits Of Congaree National Park, Maka Bitsadze

Theses and Dissertations

Protected areas are important tools for the conservation of biological diversity. They also support a wide range of ecosystem services and provide economic, cultural and social values and benefits. Many values and benefits of protected areas are poorly understood and greatly under-valued by decision-makers, the business sector, and the general public. Accordingly, identification and assessment of values and benefits of protected areas has been increasingly promoted during recent years.

This research investigates values and benefits of Congaree National Park and provides guidance for the further economic valuation of identified values and benefits. While the ecological significance of Congaree National Park …


Dissolved Organic Matter Composition And Bioavailability Reflect Ecosystem Productivity In The Western Arctic Ocean, Yuan Shen, Cedric Fichot, Ronald Benner Dec 2012

Dissolved Organic Matter Composition And Bioavailability Reflect Ecosystem Productivity In The Western Arctic Ocean, Yuan Shen, Cedric Fichot, Ronald Benner

Faculty Publications

Dissolved organic carbon (DOC) and total dissolved amino acids (TDAA) were measured in high (Chukchi Sea) and low (Beaufort Sea) productivity regions of the western Arctic Ocean to investigate the composition and bioavailability of dissolved organic matter (DOM). Concentrations and DOC-normalized yields of TDAA in Chukchi surface waters were relatively high, indicating an accumulation of bioavailable DOM. High concentrations and yields of TDAA were also observed in the upper halocline of slope and basin waters, indicating off-shelf transport of bioavailable DOM from the Chukchi Sea. In contrast, concentrations and yields of TDAA in Beaufort surface waters were relatively low, indicting …


Atmospheric Organic Material And The Nutrients Nitrogen And Phosphorus It Carries To The Ocean, Maria Kanakidou, Robert A. Duce, Joseph M. Prospero, Alex R. Baker, Claudia R. Benitez-Nelson, Frank J. Dentener, Keith A. Hunter, Peter S. Liss, Natalie Mahowald, Gregory S. Okin, Manmohan Sarin, Kostas Tsigaridis, Mitsuo Uematsu, Lauren M. Zamora, Tong Zhu Sep 2012

Atmospheric Organic Material And The Nutrients Nitrogen And Phosphorus It Carries To The Ocean, Maria Kanakidou, Robert A. Duce, Joseph M. Prospero, Alex R. Baker, Claudia R. Benitez-Nelson, Frank J. Dentener, Keith A. Hunter, Peter S. Liss, Natalie Mahowald, Gregory S. Okin, Manmohan Sarin, Kostas Tsigaridis, Mitsuo Uematsu, Lauren M. Zamora, Tong Zhu

Faculty Publications

[1] The global tropospheric budget of gaseous and particulate non‐methane organic matter (OM) is re‐examined to provide a holistic view of the role that OM plays in transporting the essential nutrients nitrogen and phosphorus to the ocean. A global 3‐dimensional chemistry‐transport model was used to construct the first global picture of atmospheric transport and deposition of the organic nitrogen (ON) and organic phosphorus (OP) that are associated with OM, focusing on the soluble fractions of these nutrients. Model simulations agree with observations within an order of magnitude. Depending on location, the observed water soluble ON fraction ranges from ∼3% to …


Potential Role Of Inorganic Polyphosphate In The Cycling Of Phosphorus Within The Hypoxic Water Column Of Effingham Inlet, British Columbia, Julia M. Diaz, Ellery D. Ingall, Samuel D. Snow, Claudia R. Benitez-Nelson, Martial Taillefert, Jay A. Brandes Jun 2012

Potential Role Of Inorganic Polyphosphate In The Cycling Of Phosphorus Within The Hypoxic Water Column Of Effingham Inlet, British Columbia, Julia M. Diaz, Ellery D. Ingall, Samuel D. Snow, Claudia R. Benitez-Nelson, Martial Taillefert, Jay A. Brandes

Faculty Publications

[1] The upper basin of Effingham Inlet possesses permanently anoxic bottom waters, with a water column redox transition zone typically occurring at least 40 m above the sediment‐water interface. During our sampling campaign in April and July 2007, this redox transition zone was associated with sharp peaks in a variety of parameters, including soluble reactive phosphorus (SRP) and total particulate phosphorus (TPP). Based on sequential extraction results, TPP maxima exhibited preferential accumulation of an operationally defined class of loosely adsorbed organic phosphorus (P), which may contain a substantial fraction of polyphosphate (poly‐P). This poly‐P may furthermore be involved in the …


Magnitude And Composition Of Sinking Particulate Phosphorus Fluxes In Santa Barbara Basin, California, Emily Sekula‐Wood, Claudia R. Benitez-Nelson, Melissa A. Bennett, Robert Thunell May 2012

Magnitude And Composition Of Sinking Particulate Phosphorus Fluxes In Santa Barbara Basin, California, Emily Sekula‐Wood, Claudia R. Benitez-Nelson, Melissa A. Bennett, Robert Thunell

Faculty Publications

[1] The composition and bioavailability of particulate P influence marine biological community production on both modern and geologic time‐scales, and continental margins play a critical role in the supply, modification, and storage of particulate P. This study examined particulate P cycling in the Santa Barbara Basin (SBB) off the coast of southern California using a ∼520 m deep‐moored sediment trap deployed from 1993–2006 and a sediment core collected in 2005 directly beneath the sediment trap at 590 m. Total particulate P (TPP), particulate inorganic P (PIP), and particulate organic P (POP) were quantified using a 5‐step sequential extraction method (SEDEX) …


The Transcriptome And Proteome Of The Diatom Thalassiosira Pseudonana Reveal A Diverse Phosphorus Stress Response, Sonya T. Dyhrman, Bethany D. Jenkins, Tatiana A. Rynearson, Mak A. Saito, Melissa L. Mercier, Harriet Alexander, Leann P. Whitney, Andrea Drzewianowski, Vladimir V. Bulygin, Erin M. Bertrand, Zhijin Wu, Claudia R. Benitez-Nelson, Abigail Heithoff Mar 2012

The Transcriptome And Proteome Of The Diatom Thalassiosira Pseudonana Reveal A Diverse Phosphorus Stress Response, Sonya T. Dyhrman, Bethany D. Jenkins, Tatiana A. Rynearson, Mak A. Saito, Melissa L. Mercier, Harriet Alexander, Leann P. Whitney, Andrea Drzewianowski, Vladimir V. Bulygin, Erin M. Bertrand, Zhijin Wu, Claudia R. Benitez-Nelson, Abigail Heithoff

Faculty Publications

Phosphorus (P) is a critical driver of phytoplankton growth and ecosystem function in the ocean. Diatoms are an abundant class of marine phytoplankton that are responsible for significant amounts of primary production. With the control they exert on the oceanic carbon cycle, there have been a number of studies focused on how diatoms respond to limiting macro and micronutrients such as iron and nitrogen. However, diatom physiological responses to P deficiency are poorly understood. Here, we couple deep sequencing of transcript tags and quantitative proteomics to analyze the diatom Thalassiosira pseudonana grown under P-replete and P-deficient conditions. A total of …


H2/Ch4 Ratios Cannot Reliably Distinguish Abiotic Vs. Biotic Methane In Natural Hydrothermal Systems, Susan Q. Lang, G. L. Früh-Green, D. S. Kelley, M. D. Lilley, G. Proskurowski, E. P. Reeves Jan 2012

H2/Ch4 Ratios Cannot Reliably Distinguish Abiotic Vs. Biotic Methane In Natural Hydrothermal Systems, Susan Q. Lang, G. L. Früh-Green, D. S. Kelley, M. D. Lilley, G. Proskurowski, E. P. Reeves

Faculty Publications

No abstract provided.


Measurements And Three-Dimensional Modeling Of Nearshore Circulation On A South Carolina Beach, Nirnimesh Kumar, George Voulgaris, John C. Warner Apr 2011

Measurements And Three-Dimensional Modeling Of Nearshore Circulation On A South Carolina Beach, Nirnimesh Kumar, George Voulgaris, John C. Warner

Faculty Publications

A numerical modeling system for simulating nearshore surf zone conditions and tidal processes is presented and evaluated with in situ data. The modeling system is comprised of the Regional Ocean Modeling System (ROMS v 3.0), a three-dimensional numerical ocean model, coupled with Simulating Waves Nearshore (SWAN), a spectral wave propagation model. The system has been modified with a new vertical distribution of radiation stress terms for applications in very shallow waters. The model performance is evaluated by comparing simulations to hydrodynamic data (wave height, direction, longshore and cross-shore currents) collected in the surf zone in northern South Carolina, U.S. Model …


Two-Stepping Into The Icehouse: East Antarctic Weathering During Progressive Ice-Sheet Expansion At The Eocene–Oligocene Transition, Howie Scher, Steven M. Bohaty, James C. Zachos, Margaret L. Delaney Apr 2011

Two-Stepping Into The Icehouse: East Antarctic Weathering During Progressive Ice-Sheet Expansion At The Eocene–Oligocene Transition, Howie Scher, Steven M. Bohaty, James C. Zachos, Margaret L. Delaney

Faculty Publications

In conjunction with increasing benthic foraminiferal 18O values at the Eocene–Oligocenetransition (EOT; ca. 34 Ma), coarse-grained ice-rafted debris (IRD; >425 μm) appearsabruptly alongside fossil fi sh teeth with continentally derived neodymium (Nd) isotope ratios( Nd) in Kerguelen Plateau (Southern Ocean) sediments. Increased Antarctic weathering fl ux,as inferred from two steps to less radiogenic Nd values, coincides with two steps in benthicforaminiferal 18O values. These results indicate that two distinct surges of weathering weregenerated by East Antarctic ice growth during the EOT. Weathering by ice sheets during aprecursor glaciation at 33.9 Ma did not produce signifi cant IRD accumulation during the …


Detecting Toxic Diatom Blooms From Ocean Color And A Regional Ocean Model, Clarissa R. Anderson, Raphael M. Kudela, Claudia R. Benitez-Nelson, Emily Sekula-Wood, Christopher T. Burrell, Yi Chao, Gregg Langlois, Jo Goodman, David A. Siegel Feb 2011

Detecting Toxic Diatom Blooms From Ocean Color And A Regional Ocean Model, Clarissa R. Anderson, Raphael M. Kudela, Claudia R. Benitez-Nelson, Emily Sekula-Wood, Christopher T. Burrell, Yi Chao, Gregg Langlois, Jo Goodman, David A. Siegel

Faculty Publications

[1] An apparent link between upwelling‐related physical signatures, macronutrients, and toxic diatom blooms in the various “hotspots” throughout California has motivated attempts to forecast harmful algal blooms (HABs) as a function of select environmental variables. Empirical models for predicting toxic Pseudo‐nitzschia blooms in one such region, the Santa Barbara Channel (SBC), are tested in a nowcast mode using predictions based on merging data from MODIS ocean color geophysical products and the Regional Ocean Modeling System (ROMS) applied to the Southern California Bight. Thresholds for each model generate event forecasts. Spatially‐explicit, monthly HAB maps are compared to shipboard observations and California …


Shelf Edge Tide Correlated Eddies Along The Southeastern United States, Dana K. Savidge, Jonathan Norman, Colton Smith, Julie A. Amft, Trent Moore, Catherine Edwards, George Voulgaris Nov 2010

Shelf Edge Tide Correlated Eddies Along The Southeastern United States, Dana K. Savidge, Jonathan Norman, Colton Smith, Julie A. Amft, Trent Moore, Catherine Edwards, George Voulgaris

Faculty Publications

High frequency radar observations in the Southeastern United States have revealed sequences of small short‐lived cyclonic eddies along the shoreward edge of the Gulf Stream, that spin up as the local tide turns alongshelf antiparallel to the Stream. Eddies propagate equatorward along the shelf edge, sometimes progressing shoreward before dissipating one to three hours later. They are distinctly different from Gulf Stream meander eddies, which propagate poleward. In this article, radar and mooring data are used to establish three important aspects of these neweddies: they represent an instability process operating at a previously unidentified frequency, scale, and cross‐Stream position; they …


Insights Into Particle Formation And Remineralization Using The Short-Lived Radionuclide, Thorium-234, Kanchan Maiti, Claudia R. Benitez-Nelson, Ken O. Buesseler Aug 2010

Insights Into Particle Formation And Remineralization Using The Short-Lived Radionuclide, Thorium-234, Kanchan Maiti, Claudia R. Benitez-Nelson, Ken O. Buesseler

Faculty Publications

[1] Simple mass balance models are applied to a high resolution 234Th profile from the northwest Pacific to examine the magnitude, rate, and depth distribution of particle remineralization processes below the euphotic zone (Ez). Here, excess 234Th (234Th > 238U) below the Ez is attributed to fragmentation processes that result in the conversion of sinking to non‐sinking particles. By considering particulate organic carbon (POC) to 234Th ratios on particles, we show that POC flux attenuation is larger than for 234Th, which we attribute to bacterial and zooplankton consumption of sinking POC. Three case studies are used to demonstrate how different combinations …


Wind Speed Dependence Of Single-Site Wave-Height Retrievals From High-Frequency Radars, Brian K. Haus, Lynn K. Shay, Paul A. Work, George Voulgaris, Rafael J. Ramos, Jorge Martinez-Pedraja Aug 2010

Wind Speed Dependence Of Single-Site Wave-Height Retrievals From High-Frequency Radars, Brian K. Haus, Lynn K. Shay, Paul A. Work, George Voulgaris, Rafael J. Ramos, Jorge Martinez-Pedraja

Faculty Publications

Wave-height observations derived from single-site high-frequency (HF) radar backscattered Doppler spectra are generally recognized to be less accurate than overlapping radar techniques but can provide significantly larger sampling regions. The larger available wave-sampling region may have important implications for observing system design. Comparison of HF radar–derived wave heights with acoustic Doppler profiler and buoy data revealed that the scale separation between the Bragg scattering waves and the peak energy-containing waves may contribute to errors in the single-site estimates in light-to-moderate winds. A wave-height correction factor was developed that explicitly considers this scale separation and eliminates the trend of increasing errors …


Structural And Stratigraphic Control On The Migration Of A Contaminant Plume At The P Reactor Area, Savannah River Site, South Carolina, Antonio E. Cameron González, Camelia C. Knapp, Michael G. Waddell, Adrian Addison, John M. Shafer Jun 2010

Structural And Stratigraphic Control On The Migration Of A Contaminant Plume At The P Reactor Area, Savannah River Site, South Carolina, Antonio E. Cameron González, Camelia C. Knapp, Michael G. Waddell, Adrian Addison, John M. Shafer

Faculty Publications

Geophysical methods, including a shallow seismic reflection (SSR) survey, surface and borehole ground-penetrating radar (GPR) data, and electrical resistivity imaging (ERI), were conducted at the Savannah River site (SRS), South Carolina, to investigate the shallow stratigraphy, hydrogeophysical zonation, and the applicability and performance of these geophysical techniques for hydrogeological characterization in contaminant areas. The study site is the P Reactor area located within the upper Atlantic coastal plain, with clastic sediments ranging from Late Cretaceous to Miocene in age. The target of this research was the delineation and prediction of migration pathways of a trichloroethylene (TCE) contaminant plume that originates …


The Holocene Depositional History Of Thousand Acre Marsh (Georgetown County, Sc, Usa) From Correlation Of Ground Penetrating Radar With Subsurface Stratigraphy, A L. Springer, Camelia C. Knapp, Paul T. Gayes, Leonard R. Gardiner May 2010

The Holocene Depositional History Of Thousand Acre Marsh (Georgetown County, Sc, Usa) From Correlation Of Ground Penetrating Radar With Subsurface Stratigraphy, A L. Springer, Camelia C. Knapp, Paul T. Gayes, Leonard R. Gardiner

Faculty Publications

No abstract provided.


Slab Window Migration And Terrane Accretion Preserved By Low‐Temperature Thermochronology Of A Magmatic Arc, Northern Antarctic Peninsula, William R. Guenthner, David L. Barbeau Jr, Peter W. Reiners, Stuart N. Thomson Mar 2010

Slab Window Migration And Terrane Accretion Preserved By Low‐Temperature Thermochronology Of A Magmatic Arc, Northern Antarctic Peninsula, William R. Guenthner, David L. Barbeau Jr, Peter W. Reiners, Stuart N. Thomson

Faculty Publications

Existing paleogeographic reconstructions indicate that the northern Antarctic Peninsula was central to several Mesozoic and Cenozoic tectonic events that have implications for ocean circulation and continental margin evolution. To evaluate the exhumational record of these processes, we collected new samples and measured fission track and (U‐Th)/He cooling ages of apatite and zircon from 13 Jurassic and Cretaceous granitoids in western Graham Land between the northern tip of the peninsula and the Antarctic Circle. Apatite He data reveal distinct ages and systematic age patterns north and south of Anvers Island, near the midpoint of the study area: To the south, apatite …


Analysis Of Fluvial Suspended Sediment Load Contribution Through Anthropocene History To The South Atlantic Bight Coastal Zone, U.S.A., K Mccarney-Castle, George Voulgaris, A J. Kettner Jan 2010

Analysis Of Fluvial Suspended Sediment Load Contribution Through Anthropocene History To The South Atlantic Bight Coastal Zone, U.S.A., K Mccarney-Castle, George Voulgaris, A J. Kettner

Faculty Publications

Discerning the effects of anthropogenic activities (i.e., reservoir construction, land use change), as opposed to those of natural processes (i.e., climate variability), on suspended sediment flux has become an increasingly difficult challenge. This contribution presents water and suspended sediment flux from five major watersheds that discharge into the southeastern U.S. Atlantic, a region that is currently considered sediment starved. Three periods of Anthropocenetime were defined and evaluated: (1) “pre-European conditions” (1680–1700), (2) “pre-dam conditions" (1905-1925), and (3) "post-dam conditions" (1985-2005). Physical and hydrologic watershed data were used to run a climate-driven hydrological transport numerical model (HydroTrend) to estimate …


Application Of Foreland Basin Detrital-Zircon Geochronology To The Reconstruction Of The Southern And Central Appalachian Orogen, Hyunmee Park, David L. Barbeau Jr, Alan Rickenbaker, Denise Bachmann-Krug, George E. Gehrels Jan 2010

Application Of Foreland Basin Detrital-Zircon Geochronology To The Reconstruction Of The Southern And Central Appalachian Orogen, Hyunmee Park, David L. Barbeau Jr, Alan Rickenbaker, Denise Bachmann-Krug, George E. Gehrels

Faculty Publications

We report the U-Pb age distribution of detrital zircons collected from central and southern Appalachian foreland basin strata, which record changes of sediment provenance in response to the different phases of the Appalachian orogeny. Taconic clastic wedges have predominantly ca. 1080–1180 and ca. 1300–1500 Ma zircons, whereas Acadian clastic wedges contain abundant Paleozoic zircons and minor populations of 550–700 and 1900–2200 Ma zircons consistent with a Gondwanan affinity. Alleghanian clastic wedges contain large populations of ca. 980–1080 Ma and ca. 2700 Ma and older Archean zircons and fewer Paleozoic zircons than occur in the Acadian clastic wedges. The abundance of …


Empirical Mode Decomposition Operator For Dewowing Gpr Data, Bradley M. Battista, Adrian Addison, Camelia C. Knapp Dec 2009

Empirical Mode Decomposition Operator For Dewowing Gpr Data, Bradley M. Battista, Adrian Addison, Camelia C. Knapp

Faculty Publications

Signal processing tools available to ground penetrating radar data used for shallow subsurface imaging and hydrogeophysical parameter estimation are significantly handled using the same tools available to seismic reflection data. Overall, the same tools produce interpretable images from both data types, but particular noise (wow noise) in electromagnetic data must be removed before stable and accurate quantitative results can be produced. Wow noise is an inherent, nonlinear electromagnetic interference and a significant component of GPR data. Further, the nonlinear and non-stationary nature of wow noise provides a strong argument for preprocessing radar traces with time-domain operators. Time-domain operators designed for …


Improved Hydrogeophysical Parameter Estimation From Empirical Mode Decomposition Processed Ground Penetrating Radar Data, Adrian Addison, Bradley M. Battista, Camelia C. Knapp Dec 2009

Improved Hydrogeophysical Parameter Estimation From Empirical Mode Decomposition Processed Ground Penetrating Radar Data, Adrian Addison, Bradley M. Battista, Camelia C. Knapp

Faculty Publications

Various techniques have been designed to maximize the use of ground penetrating radar (GPR) as an exploration tool. Improvements in signal processing are expected to further facilitate the accuracy of parameters derived from using GPR in certain geologic environments. Common-offset GPR data were collected at the Marine Corps Air Station (MCAS) in Beaufort, South Carolina, and dielectric constants were calculated following the application of the empirical mode decomposition (EMD) for dewowing GPR traces. Conventional signal processing is applied to the GPR traces to provide hydrogeophysical parameter estimates such as volumetric water content, porosity, and hydraulic conductivity. The results are validated …


Revised Crustal Architecture Of The Southeastern Carpathian Foreland From Active And Passive Seismic Data, Dana M. Enciu, Camelia C. Knapp, James H. Knapp Aug 2009

Revised Crustal Architecture Of The Southeastern Carpathian Foreland From Active And Passive Seismic Data, Dana M. Enciu, Camelia C. Knapp, James H. Knapp

Faculty Publications

Integration of active and passive source seismic data is employed in order to study the nature of the relationships between crustal seismicity and geologic structures in the southeastern (SE) Carpathian foreland of Romania and the possible connection with the Vrancea Seismogenic Zone (VSZ) of intermediatedepth seismicity, one of the most active earthquakeprone areas in Europe. Crustal epicenters and focal mechanisms are correlated with four deep industry seismic profiles, the reprocessed Danube and Carpathian Integrated Action on Process in the Lithosphere and Neotectonics (DACIA PLAN) profile and the Deep Reflection Acquisition Constraining Unusual Lithospheric Activity II and III (DRACULA) profiles in …


Developing A Robust Geologic Conceptual Model Using Pseudo 3-D P-Wave Seismic Reflection Data, Adrian Addison, Michael G. Waddell, Camelia C. Knapp, Duke T. Brantley, John M. Shafer Mar 2009

Developing A Robust Geologic Conceptual Model Using Pseudo 3-D P-Wave Seismic Reflection Data, Adrian Addison, Michael G. Waddell, Camelia C. Knapp, Duke T. Brantley, John M. Shafer

Faculty Publications

As part of a multiscale hydrogeophysical and modeling study, a pseudo three-dimensional (3-D) seismic surveywas conducted over a contaminant plume at P area, Savannah River site (South Carolina), to enhance the existing geologicmodel by resolving uncertainties in the lithostratigraphic sequence. The geometry of the dissolved phase trichloroethylene plume, based on initial site characterization, appears to be confined to a narrow corridor within the Eocene sand overlying a clay unit approximately 25m(82 ft) below land surface. Processing the seismic data as a 3-D data volume instead of a series of closely spaced two-dimensional lines allowed for better interpretation of the target …