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Full-Text Articles in Geology

Response Of Antarctic Cryoconite Microbial Communities To Light, Elizabeth A. Bagshaw, Jemma L. Wadham, Martyn Tranter, Rupert Perkins, Alistair Morgan, Christopher J. Williamson, Andrew G. Fountain, Sean Fitzsimons, Ashley Dubnick Jan 2016

Response Of Antarctic Cryoconite Microbial Communities To Light, Elizabeth A. Bagshaw, Jemma L. Wadham, Martyn Tranter, Rupert Perkins, Alistair Morgan, Christopher J. Williamson, Andrew G. Fountain, Sean Fitzsimons, Ashley Dubnick

Geology Faculty Publications and Presentations

Microbial communities on polar glacier surfaces are found dispersed on the ice surface, or concentrated in cryoconite holes and cryolakes, which are accumulations of debris covered by a layer of ice for some or all of the year. The ice lid limits the penetration of photosynthetically available radiation (PAR) to the sediment layer, since the ice attenuates up to 99% of incoming radiation. This suite of field and laboratory experiments demonstrates that PAR is an important control on primary production in cryoconite and cryolake ecosystems. Increased light intensity increased efficiency of primary production in controlled laboratory incubations of debris from …


Geotherms From The Temperature-Depth–Constrained Solutions Of 1-D Steady-State Heat-Flow Equation, Dhananjay Ravat, P. Morgan, A. R. Lowry Jan 2016

Geotherms From The Temperature-Depth–Constrained Solutions Of 1-D Steady-State Heat-Flow Equation, Dhananjay Ravat, P. Morgan, A. R. Lowry

Earth and Environmental Sciences Faculty Publications

We use the Curie depth derived from spectral analysis of near-surface magnetic anomaly data to constrain the solution of a one-dimensional (1-D) steady-state heat-flow equation. The method, in addition to anchoring the geotherm at deep levels in the crust, yields the ratio of radiogenic heat pro- duction to thermal conductivity. We evaluate the utility of this constraint in two granitic regions in the United States where radiogenic heat production, thermal conductivity, and heat flow are well determined. We also examine the results of this method in the context of previous research in the central Red Sea and coastal Saudi Arabia. …


Sedimentologic And Stratigraphic Analysis Of Synrift Siliciclastic Fluvial And Lacustrine Strata In The Lower Cretaceous Upper Yucca Formation, Indio Mountains, West Texas, Matthew Robert Fox Jan 2016

Sedimentologic And Stratigraphic Analysis Of Synrift Siliciclastic Fluvial And Lacustrine Strata In The Lower Cretaceous Upper Yucca Formation, Indio Mountains, West Texas, Matthew Robert Fox

Open Access Theses & Dissertations

Outcrops of the upper Yucca Formation in the Indio Mountains near Van Horn, Texas provide temporal, tectonic, and climatic similarities to Lower Cretaceous, synrift, greenhouse pre-salt lacustrine strata along in the subsurface of the South Atlantic margin. These "pre-salt" strata hold prolific petroleum reservoirs but despite extensive seismic studies performed for regional scale hydrocarbon exploration in these lacustrine reservoirs, sedimentologic and stratigraphic analyses have rarely been published. The Upper Yucca Formation in the Indio Mountains contain lacustrine reservoir analogs that intertongue with fluvial and deltaic sandstones. Near Squaw Canyon, fluvial-deltaic sandstones are reduced in abundance to lacustrine carbonates by nearly …


Modeling Spring Catchment Discharge: A Case Study Of Candela, Panama, Central America, Jordan P. Van Sickle Jan 2016

Modeling Spring Catchment Discharge: A Case Study Of Candela, Panama, Central America, Jordan P. Van Sickle

Dissertations, Master's Theses and Master's Reports

Where the proper geological and hydrological conditions exist, natural springs have provided a reliable source of clean water to mankind for eons. Changing climates and land development can negatively impact spring source replenishment and threaten their reliability as a source of water. In the face of prospects of diminishing supplies and increasing population demands, community leaders question whether and how to invest in development for enhancing sustainability and protecting water quality, causing water managers to dispute their reliability given decreasing flows. Springs located in the rugged jungle of western Panama serve as the primary water supply for many indigenous communities, …


Coherent Late-Holocene Climate-Driven Shifts In The Structure Of Three Rocky Mountain Lakes, Jeffrey R. Stone, Jasmine E. Saros, Gregory T. Pederson Jan 2016

Coherent Late-Holocene Climate-Driven Shifts In The Structure Of Three Rocky Mountain Lakes, Jeffrey R. Stone, Jasmine E. Saros, Gregory T. Pederson

United States Geological Survey: Staff Publications

Large-scale atmospheric pressure centers, such as the Aleutian and Icelandic Low, have a demonstrated relationship with physical lake characteristics in contemporary monitoring studies, but the responses to these phenomena are rarely observed in lake records. We observe coherent changes in the stratification patterns of three deep (>30 m) lakes inferred from fossil diatom assemblages as a response to shifts in the location and intensity of the Aleutian Low and compare these changes with similar long-term changes observed in the 18O record from the Yukon. Specifically, these records indicate that between 3.2 and 1.4 ka, the Aleutian Low shifted …


Using Satellite Vegetation And Compound Topographic Indices To Maphighly Erodible Cropland Buffers For Cellulosic Biofuel Cropdevelopments In Eastern Nebraska, Usa, Yingxin Gu, Bruce K. Wylie Jan 2016

Using Satellite Vegetation And Compound Topographic Indices To Maphighly Erodible Cropland Buffers For Cellulosic Biofuel Cropdevelopments In Eastern Nebraska, Usa, Yingxin Gu, Bruce K. Wylie

United States Geological Survey: Staff Publications

Cultivating annual row crops in high topographic relief waterway buffers has negative environmental effects and can be environmentally unsustainable. Growing perennial grasses such as switchgrass(Panicum virgatum L.) for biomass (e.g., cellulosic biofuel feedstocks) instead of annual row crops in these high relief waterway buffers can improve local environmental conditions (e.g., reduce soil erosion and improve water quality through lower use of fertilizers and pesticides) and ecosystem services (e.g.,minimize drought and flood impacts on production; improve wildlife habitat, plant vigor, and nitro-gen retention due to post-senescence harvest for cellulosic biofuels; and serve as carbon sinks). The main objectives of this …


Deep Subsurface Drip Irrigation Using Coal-Bed Sodic Water: Part Ii. Geochemistry, Carleton R. Bern, George N. Breit, Richard W. Healy, John W. Zupancic Jan 2016

Deep Subsurface Drip Irrigation Using Coal-Bed Sodic Water: Part Ii. Geochemistry, Carleton R. Bern, George N. Breit, Richard W. Healy, John W. Zupancic

United States Geological Survey: Staff Publications

Waters with low salinity and high sodium adsorption ratios (SARs) present a challenge to irrigation because they degrade soil structure and infiltration capacity. In the Powder River Basin of Wyoming, such low salinity (electrical conductivity, EC 2.1 mS cm−1) and high-SAR (54) waters are co-produced with coal-bed methane and some are used for subsurface drip irrigation (SDI). The SDI system studied mixes sulfuric acid with irrigation water and applies water year-round via drip tubing buried 92 cm deep. After six years of irrigation, SAR values between 0 and 30 cm depth (0.5–1.2) are only slightly increased over non-irrigated …


Geochemical Evidence For Seasonal Controls On The Transportation Of Holocene Loess, Matanuska Valley, Southern Alaska, Usa, Daniel R. Muhs, James R. Budahn, Gary Skipp, John P. Mcgeehin Jan 2016

Geochemical Evidence For Seasonal Controls On The Transportation Of Holocene Loess, Matanuska Valley, Southern Alaska, Usa, Daniel R. Muhs, James R. Budahn, Gary Skipp, John P. Mcgeehin

United States Geological Survey: Staff Publications

Loess is a widespread Quaternary deposit in Alaska and loess accretion occurs today in some regions, such as the Matanuska Valley. The source of loess in the Matanuska Valley has been debated for more than seven decades, with the Knik River and the Matanuska River, both to the east, being the leading candidates and the Susitna River, to the west, as a less favorable source. We report here new stratigraphic, mineralogic, and geochemical data that test the competing hypotheses of these river sources. Loess thickness data are consistent with previous studies that show that a source or sources lay to …


Retrospective: Adjusting Contaminant Concentrations In Bird Eggs To Account For Moisture And Lipid Loss During Their Incubation, Barnett A. Rattner, Stanley N. Wiemeyer, Lawrence J. Blus Jan 2016

Retrospective: Adjusting Contaminant Concentrations In Bird Eggs To Account For Moisture And Lipid Loss During Their Incubation, Barnett A. Rattner, Stanley N. Wiemeyer, Lawrence J. Blus

United States Geological Survey: Staff Publications

By the 1960s, research and monitoring efforts on chlorinated

pesticide residues in tissues of wildlife were well

underway in North America and Europe. Conservationists

and natural resource managers were attempting to resolve

whether pesticide exposure and accumulated residues were

related to population declines in several species of predatory

and scavenging birds (e.g., bald eagle Haliaeetus

leucocephalus, peregrine falcon Falco peregrinus, brown

pelican Pelecanus occidentalis and osprey Pandion haliaetus).

The avian egg was a favored sampling matrix even

before the realization that eggshell thinning was linked to

population declines (Ratcliffe 1967; Hickey and Anderson

1968) and that the …


Component Greenhouse Gas Fluxes And Radiative Balance From Two Deltaic Marshes In Louisiana: Pairing Chamber Techniques And Eddy Covariance, Ken W. Krauss, Guerry O. Holm Jr., Brian C. Perez, David E. Mcwhorter, Nicole Cormier, Rebecca F. Moss, Darren J. Johnson, Scott C. Neubauer, Richard C. Raynie Jan 2016

Component Greenhouse Gas Fluxes And Radiative Balance From Two Deltaic Marshes In Louisiana: Pairing Chamber Techniques And Eddy Covariance, Ken W. Krauss, Guerry O. Holm Jr., Brian C. Perez, David E. Mcwhorter, Nicole Cormier, Rebecca F. Moss, Darren J. Johnson, Scott C. Neubauer, Richard C. Raynie

United States Geological Survey: Staff Publications

Coastal marshes take up atmospheric CO2 while emitting CO2, CH4, and N2O. This ability to sequester carbon (C) is much greater for wetlands on a per area basis than from most ecosystems, facilitating scientific, political, and economic interest in their value as greenhouse gas sinks. However, the greenhouse gas balance of Gulf of Mexico wetlands is particularly understudied. We describe the net ecosystem exchange (NEEc) of CO2 and CH4 using eddy covariance (EC) in comparison with fluxes of CO2, CH4, and N2O using …


Mapping Marginal Croplands Suitable For Cellulosic Feedstock Crops In The Great Plains, United States, Yingxin Gu, Bruce K. Wylie Jan 2016

Mapping Marginal Croplands Suitable For Cellulosic Feedstock Crops In The Great Plains, United States, Yingxin Gu, Bruce K. Wylie

United States Geological Survey: Staff Publications

Growing cellulosic feedstock crops (e.g., switchgrass) for biofuel is more environmentally sustainable than cornbased ethanol. Specifically, this practice can reduce soil erosion and water quality impairment from pesticides and fertilizer, improve ecosystem services and sustainability (e.g., serve as carbon sinks), and minimize impacts on global food supplies. The main goal of this study was to identify high-risk marginal croplands that are potentially suitable for growing cellulosic feedstock crops (e.g., switchgrass) in the US Great Plains (GP). Satellitederived growing season Normalized Difference Vegetation Index, a switchgrass biomass productivity map obtained from a previous study, US Geological Survey (USGS) irrigation and crop …


Evaluating Methods To Establish Habitat Suitability Criteria: A Case Study In The Upper Delaware River Basin, Usa, H. S. Galbraith, C. J. Blakeslee, J. C. Cole, C. A. Talbert, K. O. Maloney Jan 2016

Evaluating Methods To Establish Habitat Suitability Criteria: A Case Study In The Upper Delaware River Basin, Usa, H. S. Galbraith, C. J. Blakeslee, J. C. Cole, C. A. Talbert, K. O. Maloney

United States Geological Survey: Staff Publications

Defining habitat suitability criteria (HSC) of aquatic biota can be a key component to environmental flow science. HSC can be developed through numerous methods; however, few studies have evaluated the consistency of HSC developed by different methodologies. We directly compared HSC for depth and velocity developed by the Delphi method (expert opinion) and by two primary literature meta-analyses (literature- derived range and interquartile range) to assess whether these independent methods produce analogous criteria for multiple species (rainbow trout, brown trout, American shad, and shallow fast guild) and life stages. We further evaluated how these two independently developed HSC affect calculations …


Evaluating Land Cover Influences On Model Uncertainties—A Case Study Of Cropland Carbon Dynamics In The Mid-Continent Intensive Campaign Region, Zhengpeng Li, Shuguang Liu, Xuesong Zhang, Tristram O. West, Stephen M. Ogle, Naijun Zhou Jan 2016

Evaluating Land Cover Influences On Model Uncertainties—A Case Study Of Cropland Carbon Dynamics In The Mid-Continent Intensive Campaign Region, Zhengpeng Li, Shuguang Liu, Xuesong Zhang, Tristram O. West, Stephen M. Ogle, Naijun Zhou

United States Geological Survey: Staff Publications

tQuantifying spatial and temporal patterns of carbon sources and sinks and their uncertainties acrossagriculture-dominated areas remains challenging for understanding regional carbon cycles. Character-istics of local land cover inputs could impact the regional carbon estimates but the effect has not beenfully evaluated in the past. Within the North American Carbon Program Mid-Continent Intensive (MCI)Campaign, three models were developed to estimate carbon fluxes on croplands: an inventory-basedmodel, the Environmental Policy Integrated Climate (EPIC) model, and the General Ensemble biogeo-chemical Modeling System (GEMS) model. They all provided estimates of three major carbon fluxes oncropland: net primary production (NPP), net ecosystem production (NEP), and …


Processes Contributing To Resilience Of Coastal Wetlands To Sea-Level Rise, Camille L. Stagg, Ken W. Krauss, Donald R. Cahoon, Nicole Cormier, William H. Conner, Christopher M. Swarzenski Jan 2016

Processes Contributing To Resilience Of Coastal Wetlands To Sea-Level Rise, Camille L. Stagg, Ken W. Krauss, Donald R. Cahoon, Nicole Cormier, William H. Conner, Christopher M. Swarzenski

United States Geological Survey: Staff Publications

The objectives of this study were to identify processes that contribute to resilience of coastal wetlands subject to rising sea levels and to determine whether the relative contribution of these processes varies across different wetland community types. We assessed the resilience of wetlands to sea-level rise along a transitional gradient from tidal freshwater forested wetland (TFFW) to marsh by measuring processes controlling wetland elevation. We found that, over 5 years of measurement, TFFWs were resilient, although some marginally, and oligohaline marshes exhibited robust resilience to sea-level rise. We identified fundamental differences in how resilience is maintained across wetland community types, …


Conserving California Condors In The 1980s, Noel F.R. Snyder Jan 2016

Conserving California Condors In The 1980s, Noel F.R. Snyder

United States Geological Survey: Staff Publications

By the late 1970s, the California condor (Gymnogyps californianus) was in serious trouble, with probably no more than about 30 birds left in existence, all in a mountainous region just north of Los Angeles that is vegetated mainly in chaparral and grasslands. All estimates of population size and trends offered since the early condor studies by Carl Koford in the 1930s and 1940s indicated a continuing decline toward extinction, and it appeared that few years were left before the species would be gone (see Koford, 1953; Wilbur, 1978). Evidently, the conservation steps that had been taken, including the …


Patuxent’S American Black Duck Studies From Chesapeake Bay To Maine And Beyond, Jerry R. Longcore Jan 2016

Patuxent’S American Black Duck Studies From Chesapeake Bay To Maine And Beyond, Jerry R. Longcore

United States Geological Survey: Staff Publications

The information in this chapter draws on published literature and unpublished reports written by staff members of the U.S. Geological Survey, Patuxent Wildlife Research Center (Patuxent), during its 75-year history. Reports by Bureau of Biological Survey (Biological Survey) and U.S. Fish and Wildlife Service (USFWS) personnel are included because the research entity currently known as Patuxent was formerly administered by these agencies. Some of the cited reports were prepared by USFWS scientists while they were not working at Patuxent. Literature resulting from work at other Federal and State agencies and private and academic institutions that influenced research at Patuxent on …


The Migratory Bird And Habitat Research Laboratory And The Accelerated Research Program, Richard A. Coon Jan 2016

The Migratory Bird And Habitat Research Laboratory And The Accelerated Research Program, Richard A. Coon

United States Geological Survey: Staff Publications

The Patuxent Wildlife Research Center (Patuxent) housed two important programs that were not supervised through the office of the Director of Patuxent during the 1960s and 1970s. Although they received administrative support from Patuxent, they were supervised from the U.S. Fish and Wildlife Service (USFWS) headquarters in Washington, D.C. One, the Migratory Bird Populations Station (MBPS), was established in 1961; the other, the Migratory Bird and Habitat Research Laboratory (MBHRL), was established in 1972 (Perry, 2004). This chapter briefly discusses MBPS and how some of its functions were transferred to MBHRL when this new laboratory was created.


Amino Acid Specific Stable Nitrogen Isotope Values In Avian Tissues: Insights From Captive American Kestrels And Wild Herring Gulls, C.E. Hebert, B.N. Popp, K.J. Fernie, C. Ka’Apu-Lyons, B.A. Rattner, N. Wallsgrove Jan 2016

Amino Acid Specific Stable Nitrogen Isotope Values In Avian Tissues: Insights From Captive American Kestrels And Wild Herring Gulls, C.E. Hebert, B.N. Popp, K.J. Fernie, C. Ka’Apu-Lyons, B.A. Rattner, N. Wallsgrove

United States Geological Survey: Staff Publications

Through laboratory and field studies, the utility of amino acid compound-specific nitrogen isotope analysis (AA-CSIA) in avian studies is investigated. Captive American kestrels (Falco sparverius) were fed an isotopically characterized diet and patterns in δ15N values of amino acids (AAs) were compared to those in their tissues (muscle and red blood cells) and food. Based upon nitrogen isotope discrimination between diet and kestrel tissues, AAs could mostly be categorized as source AAs (retaining baseline δ15N values) and trophic AAs (showing 15N enrichment). Trophic discrimination factors based upon the source (phenylalanine, Phe) and trophic (glutamic acid, Glu) AAs were 4.1 (muscle) …


Non-Linear Responses Of Glaciated Prairie Wetlands To Climate Warming, W. Carter Johnson, Brett Werner, Glenn R. Guntenspergen Jan 2016

Non-Linear Responses Of Glaciated Prairie Wetlands To Climate Warming, W. Carter Johnson, Brett Werner, Glenn R. Guntenspergen

United States Geological Survey: Staff Publications

The response of ecosystems to climate warming is likely to include threshold events when small changes in key environmental drivers produce large changes in an ecosystem. Wetlands of the Prairie Pothole Region (PPR) are especially sensitive to climate variability, yet the possibility that functional changes may occur more rapidly with warming than expected has not been examined or modeled. The productivity and biodiversity of these wetlands are strongly controlled by the speed and completeness of a vegetation cover cycle driven by the wet and dry extremes of climate. Two thresholds involving duration and depth of standing water must be exceeded …


Pranked By Audubon: Constantine S. Rafinesque’S Description Of John James Audubon’S Imaginary Kentucky Mammals, Neal Woodman Jan 2016

Pranked By Audubon: Constantine S. Rafinesque’S Description Of John James Audubon’S Imaginary Kentucky Mammals, Neal Woodman

United States Geological Survey: Staff Publications

The North American naturalist Constantine S. Rafinesque spent much of the year 1818 engaged in a solo journey down the Ohio River Valley to explore parts of what was then the western United States. Along the way, he visited a number of fellow naturalists, and he spent more than a week at the Henderson, Kentucky, home of artist and ornithologist John James Audubon. During the succeeding two years, Rafinesque published descriptions of new species that resulted from his expedition, including eleven species of fishes that eventually proved to have been invented by Audubon as a prank on the credulous naturalist. …


Amino Acid Specific Stable Nitrogen Isotope Values In Avian Tissues: Insights From Captive American Kestrels And Wild Herring Gulls, C.E. Hebert, B.N. Popp, K.J. Fernie, C. Ka’Apu-Lyons, B.A. Rattner, N. Wallsgrove Jan 2016

Amino Acid Specific Stable Nitrogen Isotope Values In Avian Tissues: Insights From Captive American Kestrels And Wild Herring Gulls, C.E. Hebert, B.N. Popp, K.J. Fernie, C. Ka’Apu-Lyons, B.A. Rattner, N. Wallsgrove

United States Geological Survey: Staff Publications

Through laboratory and field studies, the utility of amino acid compound-specific nitrogen isotope analysis (AA-CSIA) in avian studies is investigated. Captive American kestrels (Falco sparverius) were fed an isotopically characterized diet and patterns in δ15N values of amino acids (AAs) were compared to those in their tissues (muscle and red blood cells) and food. Based upon nitrogen isotope discrimination between diet and kestrel tissues, AAs could mostly be categorized as source AAs (retaining baseline δ15N values) and trophic AAs (showing 15N enrichment). Trophic discrimination factors based upon the source (phenylalanine, Phe) and trophic (glutamic acid, Glu) AAs were 4.1 (muscle) …


Non-Linear Responses Of Glaciated Prairie Wetlands To Climate Warming, W. Carter Johnson, Brett Werner, Glenn R. Guntenspergen Jan 2016

Non-Linear Responses Of Glaciated Prairie Wetlands To Climate Warming, W. Carter Johnson, Brett Werner, Glenn R. Guntenspergen

United States Geological Survey: Staff Publications

The response of ecosystems to climate warming is likely to include threshold events when small changes in key environmental drivers produce large changes in an ecosystem. Wetlands of the Prairie Pothole Region (PPR) are especially sensitive to climate variability, yet the possibility that functional changes may occur more rapidly with warming than expected has not been examined or modeled. The productivity and biodiversity of these wetlands are strongly controlled by the speed and completeness of a vegetation cover cycle driven by the wet and dry extremes of climate. Two thresholds involving duration and depth of standing water must be exceeded …


Pranked By Audubon: Constantine S. Rafinesque’S Description Of John James Audubon’S Imaginary Kentucky Mammals, Neal Woodman Jan 2016

Pranked By Audubon: Constantine S. Rafinesque’S Description Of John James Audubon’S Imaginary Kentucky Mammals, Neal Woodman

United States Geological Survey: Staff Publications

The North American naturalist Constantine S. Rafinesque spent much of the year 1818 engaged in a solo journey down the Ohio River Valley to explore parts of what was then the western United States. Along the way, he visited a number of fellow naturalists, and he spent more than a week at the Henderson, Kentucky, home of artist and ornithologist John James Audubon. During the succeeding two years, Rafinesque published descriptions of new species that resulted from his expedition, including eleven species of fishes that eventually proved to have been invented by Audubon as a prank on the credulous naturalist. …


Coal Genesis, John J. Renton, Thomas Repine Jan 2016

Coal Genesis, John J. Renton, Thomas Repine

Readings and Notes

Most textbooks classify coal as a sedimentary rock even though it does not fit the definition of a sedimentary rock. While a sedimentary rock is a "rock formed from the products of weathering and erosion", coal forms from the remains of land plants. In fact, coal doesn't even fit the definition of a rock. A rock is defined as "mixture of minerals" and minerals are defined as "natural occurring, solid, inorganic substances ..• " Coal is composed largely (􀀴90+%) of organic substances (macerals) which, by definition, are not minerals. If coal must be classified as a rock, because it forms …


Comparison Of Different Seismic Filtering Techniques On Prestack Inversion For Penobscot Area-Nova Scotia, Omer Emre Uygun Jan 2016

Comparison Of Different Seismic Filtering Techniques On Prestack Inversion For Penobscot Area-Nova Scotia, Omer Emre Uygun

Dissertations, Master's Theses and Master's Reports

The goal of this study is to compare three different type of seismic filtering according to their inversion results and their quality of data improvements. To do this bandpass filter, Inverse Q, and Radon transform are applied to the original NMO corrected pre-stack data from Nova-Scotia offshore Canada.

The seismic data used was provided as pre-stack data of generally good quality. The test for quality of data improvement comes from the results of inversion based on different types of filtering performed on the pre-stack gathers.

Bandpass filter, Inverse Q, and Radon transform are applied to the migrated prestack data, over …


Submarine Channel Evolution Linked To Rising Salt Dome, Mississippi Canyon, Gulf Of Mexico, Rachel C. Carter Dec 2015

Submarine Channel Evolution Linked To Rising Salt Dome, Mississippi Canyon, Gulf Of Mexico, Rachel C. Carter

LSU New Orleans Theses and Dissertations

By examining halokinetics and channel evolution in a deep-water system, we investigate how submarine channel morphology is affected by changing seascape linked to diapirism. The study area is located in Mississippi Canyon, Gulf of Mexico (GOM), situated directly off the continental slope in a prominent salt dome region. Interactions of salt domes with submarine channels in the GOM are poorly documented. Utilizing 3D seismic data and seismic geomorphology techniques, a long-lived Plio-Pleistocene submarine channel system has been investigated to develop a relationship between variable phases of salt movement and plan-form morphology of preserved channels.

We suggest that halokinetics acts as …


Stratigraphic And Structural Analysis Of Middle Atoka Formation In Aetna Gas Field, Franklin, Johnson And Logan Counties, Arkansas, Ikramuddin Bahram Dec 2015

Stratigraphic And Structural Analysis Of Middle Atoka Formation In Aetna Gas Field, Franklin, Johnson And Logan Counties, Arkansas, Ikramuddin Bahram

Graduate Theses and Dissertations

Arkoma basin is a prolific natural gas basin. The defining feature of this basin is the Atoka Formation that was deposited in the early-middle Pennsylvanian. The Atoka is held equivalent to the tectonic and structural evolution of the basin. This study focuses on one of the many gas fields in the Arkoma Basin in Arkansas to assess the stratigraphic and structural evolution that the strata in this particular field display.

Aetna Gas Field extends from T. 8N. R. 27 W to T. 9 N, R. 27 W and T. 8 N, R. 26 W to 8N, R. 27. Geographically, Aetna …


Feasibility Study Of Porous Media Compressed Air Energy Storage In South Carolina, United States Of America, Alexandra-Selene Jarvis Dec 2015

Feasibility Study Of Porous Media Compressed Air Energy Storage In South Carolina, United States Of America, Alexandra-Selene Jarvis

All Theses

Renewable Energy Systems (RES) such as solar and wind, are expected to play a progressively significant role in electricity production as the world begins to move away from an almost total reliance on nonrenewable sources of power. In the US there is increasing investment in RES as the Department of Energy (DOE) expands its wind power network to encompass the use of offshore wind resources in places such as the South Carolina (SC) Atlantic Coastal Plain. Because of their unstable nature, RES cannot be used as reliable grid-scale power sources unless power is somehow stored during excess production and recovered …


Understanding Acceptable Level Of Risk: Incorporating The Economic Cost Of Under-Managing Invasive Species, Alisha D. Davidson, Chad L. Hewitt, Donna R. Kashian Nov 2015

Understanding Acceptable Level Of Risk: Incorporating The Economic Cost Of Under-Managing Invasive Species, Alisha D. Davidson, Chad L. Hewitt, Donna R. Kashian

Environmental Science and Geology Faculty Research Publications

Management of nonindigenous species includes prevention, early detection and rapid response and control. Early detection and rapid response depend on prioritizing and monitoring sites at risk for arrival or secondary spread of nonindigenous species. Such monitoring efforts require sufficient biosecurity budgets to be effective and meet management or policy directives for reduced risk of introduction. Such consideration of risk reduction is rarely considered, however. Here, we review the concepts of acceptable level of risk (ALOR) and associated costs with respect to nonindigenous species and present a framework for aligning risk reduction priorities with available biosecurity resources. We conclude that available …


The Vulnerability Of Indo-Pacific Mangrove Forests To Sea-Level Rise, Catherine E. Lovelock, Donald R. Cahoon, Daniel A. Friess, Glenn R. Guntenspergen, Ken W. Krauss, Ruth Reef, Kerrylee Rogers, Megan L. Saunders, Frida Sidik, Andrew Swales, Neil Saintilan, Le Xuan Thuyen, Tran Triet Oct 2015

The Vulnerability Of Indo-Pacific Mangrove Forests To Sea-Level Rise, Catherine E. Lovelock, Donald R. Cahoon, Daniel A. Friess, Glenn R. Guntenspergen, Ken W. Krauss, Ruth Reef, Kerrylee Rogers, Megan L. Saunders, Frida Sidik, Andrew Swales, Neil Saintilan, Le Xuan Thuyen, Tran Triet

United States Geological Survey: Staff Publications

Sea-level rise can threaten the long-term sustainability of coastal communities and valuable ecosystems such as coral reefs, salt marshes and mangroves1,2. Mangrove forests have the capacity to keep pace with sea-level rise and to avoid inundation through vertical accretion of sediments, which allows them to maintain wetland soil elevations suitable for plant growth3. The Indo- Pacific region holds most of the world’s mangrove forests4, but sediment delivery in this region is declining, owing to anthropogenic activities such as damming of rivers5. This decline is of particular concern because the Indo-Pacific region is …