Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Geology (173)
- Environmental Sciences (147)
- Life Sciences (73)
- Hydrology (72)
- Oceanography and Atmospheric Sciences and Meteorology (67)
-
- Soil Science (60)
- Environmental Monitoring (45)
- Other Earth Sciences (41)
- Water Resource Management (40)
- Geochemistry (38)
- Geophysics and Seismology (38)
- Other Environmental Sciences (30)
- Social and Behavioral Sciences (29)
- Natural Resources Management and Policy (28)
- Environmental Indicators and Impact Assessment (27)
- Plant Sciences (26)
- Fresh Water Studies (23)
- Biogeochemistry (20)
- Geography (19)
- Climate (18)
- Natural Resources and Conservation (18)
- Engineering (17)
- Geomorphology (17)
- Oceanography (16)
- Agriculture (14)
- Glaciology (14)
- Ecology and Evolutionary Biology (13)
- Biology (12)
- Institution
-
- University of Nebraska - Lincoln (101)
- University of South Florida (40)
- TÜBİTAK (37)
- University of Kentucky (33)
- University of Nevada, Las Vegas (29)
-
- Louisiana State University (21)
- Boise State University (20)
- Missouri University of Science and Technology (16)
- California Polytechnic State University, San Luis Obispo (15)
- Department of Primary Industries and Regional Development, Western Australia (15)
- Old Dominion University (15)
- University of Texas at El Paso (15)
- Utah State University (13)
- Western Kentucky University (13)
- Brigham Young University (9)
- Central Washington University (9)
- Clemson University (9)
- Montclair State University (9)
- Portland State University (9)
- Smith College (9)
- Wright State University (9)
- University of South Carolina (8)
- Furman University (6)
- University of Texas at Arlington (6)
- West Chester University (6)
- Bryn Mawr College (5)
- Eastern Kentucky University (5)
- University of North Dakota (5)
- Columbus State University (4)
- Michigan Technological University (4)
- Keyword
-
- Water quality (13)
- Groundwater (12)
- Kentucky (12)
- Geochemistry (10)
- Department of Earth and Environmental Sciences (9)
-
- Karst (9)
- Research (9)
- Sediment (8)
- CGISS (7)
- Environmental studies (7)
- Geomorphology (7)
- Nebraska (7)
- Soil (7)
- Climate (6)
- Climate change (6)
- Copper (6)
- Environmental sciences (6)
- Furman University (6)
- Geology (6)
- Lake restoration (6)
- Salinity (6)
- Soil moisture (6)
- Agriculture (5)
- Antarctica (5)
- Caves (5)
- Drought (5)
- Geochronology (5)
- Geophysics (5)
- Hydrogeology (5)
- Natural resources (5)
- Publication
-
- Turkish Journal of Earth Sciences (37)
- Department of Earth and Atmospheric Sciences: Faculty Publications (33)
- United States Geological Survey: Staff Publications (28)
- LSU Master's Theses (19)
- UNLV Theses, Dissertations, Professional Papers, and Capstones (17)
-
- Open Access Theses & Dissertations (15)
- Studia UBB Geologia (14)
- Theses and Dissertations (13)
- International Journal of Speleology (12)
- Kentucky Alfalfa and Stored Forage Conference (11)
- Earth and Soil Sciences (10)
- All Theses (9)
- Browse all Theses and Dissertations (9)
- Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research (9)
- Faculty Publications (9)
- Geosciences: Faculty Publications (9)
- School of Geosciences Faculty and Staff Publications (9)
- Boise State University Theses and Dissertations (8)
- Department of Environmental Studies: Undergraduate Student Theses (8)
- Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works (8)
- Geosciences Faculty Publications and Presentations (7)
- OES Faculty Publications (7)
- Resource management technical reports (7)
- University of Kentucky Master's Theses (7)
- All Graduate Theses and Dissertations, Spring 1920 to Summer 2023 (6)
- Furman Lake Restoration Book Gallery (6)
- Masters Theses & Specialist Projects (6)
- Theses, Dissertations and Culminating Projects (6)
- EKU Faculty and Staff Scholarship (5)
- Earth & Environmental Sciences Theses - Archive (5)
- Publication Type
Articles 31 - 60 of 581
Full-Text Articles in Earth Sciences
Geochemical, Isotopic, And U-Pb Geochronologic Investigations Of Intrusive Basement Rocks From The Wallowa And Olds Ferry Arc Terranes, Blue Mountains Province, Oregon-Idaho, Gene Alan Kurz
Boise State University Theses and Dissertations
Late Paleozoic to Mesozoic arc terranes comprising the Blue Mountains Province of northeastern Oregon and western Idaho are poorly understood in terms of the timing and duration of recorded magmatism and deformation. Intrusive basement rocks of the Wallowa and Olds Ferry arc terranes are investigated using a combination of highprecision U-Pb geochronology, radiogenic isotope and trace element geochemistry, and structural geology to help constrain their tectonomagmatic evolution and to provide a better understanding for the accretionary history of the Blue Mountains Province.
The Cougar Creek Complex is a compositionally diverse intrusive complex interpreted as the mid-crustal portion of the Wallowa …
Kinematics And Vorticity In Kangmar Dome, Southern Tibet: Testing Midcrustal Channel-Flow Models For The Himalaya, Tom Wagner, Jeffrey Lee, Bradley R. Hacker, Gareth Seward
Kinematics And Vorticity In Kangmar Dome, Southern Tibet: Testing Midcrustal Channel-Flow Models For The Himalaya, Tom Wagner, Jeffrey Lee, Bradley R. Hacker, Gareth Seward
All Faculty Scholarship for the College of the Sciences
Kinematic, kinematic vorticity (Wm), and deformation temperature analyses were completed to test the hypothesis that midcrustal rocks exposed in the core of the Kangmar gneiss dome, southern Tibet record ductile deformation patterns of a “frozen” segment of a southward flowing midcrustal channel. Microscopic and mesoscopic kinematic indicators exhibit a downward transition from a subequal mix of top-north and top-south shear in garnet zone rocks to dominantly top-north shear in staurolite/kyanite zone and deeper rocks. Kinematic vorticity values indicate an increase in pure shear component with depth from ∼48% pure shear in chloritoid zone rocks through ∼62% in …
Amaila Falls Hydroelectric Project Model Development And Scenarios, Chris Berger, Scott A. Wells, Vanessa Wells
Amaila Falls Hydroelectric Project Model Development And Scenarios, Chris Berger, Scott A. Wells, Vanessa Wells
Civil and Environmental Engineering Faculty Publications and Presentations
The focus of this present study is to perform the following tasks:
* Develop a hydrodynamic and water quality model of the reservoir formed by the Amaila Falls Hydroelectric Project
* Develop and run modeling scenarios
Water quality model simulations of the 23.3 km2 reservoir for Amaila Falls Hydroelectric Project were conducted for low, average, and high flow years. A scenario with no vegetation removed from the reservoir for an average flow was also simulated. Conditions downstream of the reservoir were also modeled using a river model.
The model used for the reservoir formed by Amaila Falls Hydroelectric Project …
Phosphorus Export From A Restored Wetland Ecosystem In Response To Natural And Experimental Hydrologic Fluctuations, Marcelo Ardón, Shaena Montanari, Jennifer L. Morse, Martin W. Doyle, Emily S. Bernhardt
Phosphorus Export From A Restored Wetland Ecosystem In Response To Natural And Experimental Hydrologic Fluctuations, Marcelo Ardón, Shaena Montanari, Jennifer L. Morse, Martin W. Doyle, Emily S. Bernhardt
Environmental Science and Management Faculty Publications and Presentations
Wetland restoration is a commonly used approach to reduce nutrient loading to freshwater and coastal ecosystems, with many wetland restoration efforts occurring in former agricultural fields. Restored wetlands are expected to be effective at retaining or removing both nitrogen and phosphorus (P), yet restoring wetland hydrology to former agricultural fields can lead to the release of legacy fertilizer P. Here, we examined P cycling and export following rewetting of the Timberlake Restoration Project, a 440 ha restored riverine wetland complex in the coastal plain of North Carolina. We also compared P cycling within the restored wetland to two minimally disturbed …
Rare Earth Element Transport In The Yucca Mountain Region, Liqiong Zhang
Rare Earth Element Transport In The Yucca Mountain Region, Liqiong Zhang
UNLV Theses, Dissertations, Professional Papers, and Capstones
In sync with environmental pollution of solutes in nature, from source, process to consequence, geochemical processes (leaching and sorption) and hydraulic transportation of the rare earth elements (REEs) have been investigated at Yucca Mountain (YM), Nevada. This research includes the leaching behavior of trace elements (including REEs) from aquifer rocks, the surface complexation reactions of REEs in synthetic groundwater, and transportation of reactive REEs in the local-scale groundwater system of YM. This dissertation includes three projects. These studies indicate that surface complexation reactions may retard the transportation of REEs along groundwater paths in YM, which suggests a similar behavior of …
Heavy Metal Concentrations In Water And Surface Sediments Of Wilgreen Lake, Madison County, Kentucky, Chad Von Gruenigen, Walter S. Borowski
Heavy Metal Concentrations In Water And Surface Sediments Of Wilgreen Lake, Madison County, Kentucky, Chad Von Gruenigen, Walter S. Borowski
EKU Faculty and Staff Scholarship
Heavy metal pollution remains problematic in natural waters, particularly for localities near plausible anthropogenic sources. We assayed the level of heavy metals in surface waters and within surface sediments of Wilgreen Lake, whose watershed drains industrial, urban, agricultural, and residential areas near Richmond, Kentucky. Water samples were treated according to Environmental Protection Agency (EPA) protocols and digested with trace-metal-grade nitric and hydrochloric acids. Sediment samples were collected with a grab sampler and digested using established EPA procedures with hydrogen peroxide and trace-metal-grade nitric acid. Both water samples and sediment samples were sent to Activation Laboratories for analysis, and were measured …
Estimates Of The Hydraulic Parameters Of Aquifers In Cache Valley, Utah And Idaho, Paul C. Inkenbrandt
Estimates Of The Hydraulic Parameters Of Aquifers In Cache Valley, Utah And Idaho, Paul C. Inkenbrandt
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Hydraulic parameters of aquifers in Cache Valley were compiled from existing but largely unpublished data, from specific capacity data reported in well drillers' records, and from aquifer tests conducted for this study. A GIS database was also created to organize this information.
A complete and thorough literature review was performed, which included obtaining unpublished aquifer test data from state and federal agencies, as well as reviewing Drinking Water Source Protection plans for each municipality in the valley.
Well drillers' records were obtained from the Utah Division of Water Rights website and examined for pertinent information. Screened unit intervals from 1,314 …
Policy And Science Of Geothermal Heat Use At Mcmurdo Station, Antarctica, Joe Alvine
Policy And Science Of Geothermal Heat Use At Mcmurdo Station, Antarctica, Joe Alvine
Department of Environmental Studies: Undergraduate Student Theses
My thesis research project deals with the use of geothermal heat in Antarctica. Currently it is not allowed due to article 7 of the 1991 Protocol on Environmental Protection that placed a 50 moratorium on the exploitation of mineral resources. The US main base in Antarctica, McMurdo Station is currently powered by diesel generators that are inefficient, cause environmental damage, and is expensive to run. By exploring alternative energy options, McMurdo Station can reduce its dependence on non-renewable energy sources. By determining the geothermal potential of McMurdo Station, this project explores the possibilities and benefits that would occur with the …
A Comprehensive Uncertainty Analysis And Method Of Geometric Calibration For A Circular Scanning Airborne Lidar, Michael Oliver Gonsalves
A Comprehensive Uncertainty Analysis And Method Of Geometric Calibration For A Circular Scanning Airborne Lidar, Michael Oliver Gonsalves
Dissertations
This dissertation describes an automated technique for ascertaining the values of the geometric calibration parameters of an airborne lidar. A least squares approach is employed that adjusts the point cloud to a single planar surface which could be either a narrow airport runway or a dynamic sea surface. Going beyond the customary three boresight angles, the proposed adjustment can determine up to eleven calibration parameters to a precision that renders a negligible contribution to the point cloud’s positional uncertainty.
Presently under development is the Coastal Zone Mapping and Imaging Lidar (CZMIL), which, unlike most contemporary systems that use oscillating mirrors …
Geophysics At The Interface: Response Of Geophysical Properties To Solid-Fluid, Fluid-Fluid, And Solid-Solid Interfaces, Rosemary Knight, Laura J. Pyrak-Nolte, Lee D. Slater, Estella A. Atekwana, Anthony L. Endres, Jil T. Geller, David P. Lesmes, Seiji Nakagawa, Andre Revil, Mukul M. Sharma, Christian Straley
Geophysics At The Interface: Response Of Geophysical Properties To Solid-Fluid, Fluid-Fluid, And Solid-Solid Interfaces, Rosemary Knight, Laura J. Pyrak-Nolte, Lee D. Slater, Estella A. Atekwana, Anthony L. Endres, Jil T. Geller, David P. Lesmes, Seiji Nakagawa, Andre Revil, Mukul M. Sharma, Christian Straley
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
Laboratory studies reveal the sensitivity of measured geophysical properties to solid-fluid, fluid-fluid, and solid-solid interfaces in granular and fractured materials. In granular materials, electrical properties and nuclear magnetic resonance relaxation times exhibit a strong dependence on the size and properties of the solid-fluid interface. The electrical and seismic properties of granular materials and the seismic properties of fractured materials reveal a dependence on the size or geometry of fluid-fluid interfaces. Seismic properties of granular and fractured materials are affected by the effective stress and cementing material at solid-solid interfaces. There have been some recent studies demonstrating the use of field-scale …
Seismic Anisotropy Beneath The Afar Depression And Adjacent Areas: Implications For Mantle Flow, Stephen S. Gao, Kelly H. Liu, Mohammed G. Abdel Salam
Seismic Anisotropy Beneath The Afar Depression And Adjacent Areas: Implications For Mantle Flow, Stephen S. Gao, Kelly H. Liu, Mohammed G. Abdel Salam
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
Shear wave splitting is a robust tool to infer the direction and strength of seismic anisotropy in the lithosphere and underlying asthenosphere. Previous shear wave splitting studies in the Afar Depression and adjacent areas concluded that either Precambrian sutures or vertical magmatic dikes are mostly responsible for the observed anisotropy. Here we report results of a systematic analysis of teleseismic shear wave splitting using all the available broadband seismic data recorded in the Afar Depression, Main Ethiopian Rift (MER), and Ethiopian Plateau. We found that while the ~450 measurements on the Ethiopian Plateau and in the MER show insignificant azimuthal …
The Interaction Of Rock And Water During Shock Decompression: A Hybrid Model For Fluidized Ejecta Formation, Audrey Hughes Rager
The Interaction Of Rock And Water During Shock Decompression: A Hybrid Model For Fluidized Ejecta Formation, Audrey Hughes Rager
UNLV Theses, Dissertations, Professional Papers, and Capstones
Crater and ejecta morphology provide insight into the composition and structure of the target material. Martian rampart craters, with their unusual single-layered (SLE), double-layered (DLE), and multi-layered ejecta (MLE), are the subject of particular interest among planetary geologists because these morphologies are thought to result from the presence of water in the target. Also of interest are radial lines extending from the crater rim to the distal rampart of DLE craters. Exactly how these layered ejecta morphologies and radial lines form is not known, but they are generally thought to result from interaction of the ejecta with the atmosphere, subsurface …
Carbon Isotopic Fractionation Across A Late Cambrian Carbonate Platform: A Regional Response To The Spice Event As Recorded In The Great Basin, Jonathan Lloyd Baker
Carbon Isotopic Fractionation Across A Late Cambrian Carbonate Platform: A Regional Response To The Spice Event As Recorded In The Great Basin, Jonathan Lloyd Baker
UNLV Theses, Dissertations, Professional Papers, and Capstones
Geochemical models have suggested that the late Cambrian was characterized by a greenhouse climate with high pCO2. Furthermore, stableisotope analyses within the Great Basin have documented a large carbonate isotope (δ13Ccarb) excursion, known as the Steptoean Positive Carbon Isotope Excursion (SPICE). This event has been documented globally, and is interpreted as having resulted from enhanced organic carbon burial. Unless the size of carbon reservoirs in the Cambrian ocean was significantly different from those of the Cenozoic, this forcing should have resulted in a comparable carbon-isotope excursion in organic matter (δ13Corg). It is also predicted that increased organic carbon burial would …
Age And Petrogenesis Of The Roaring Mountain Rhyolites, Yellowstone Volcanic Field, Wyoming, Kathleen Marie Wooton
Age And Petrogenesis Of The Roaring Mountain Rhyolites, Yellowstone Volcanic Field, Wyoming, Kathleen Marie Wooton
UNLV Theses, Dissertations, Professional Papers, and Capstones
Extracaldera rhyolites in the Norris-Mammoth Corridor of the Yellowstone Volcanic Field (YVF) appear to be unrelated to intracaldera volcanism, resulting instead from a new crustal magma source derived from northeastward propagation of the Yellowstone “melting anomaly.” The youngest extracaldera rhyolite unit, the Roaring Mountain Member (RM), is chemically distinct from the previous extracaldera lavas, reverting to more primitive compositions.
This study suggests that the majority of the RM rhyolites erupted from the same large-scale silicic magma system. Based on geochemistry and 40Ar/39Ar geochronology, the Crystal Spring mingled rhyolite and Obsidian Cliff rhyolite erupted concurrently at 59.1 ± 2.0 ka. The …
Late Paleozoic Deformation In The Osgood Mountains And Dry Hills, Northern Nevada, Samuel A. Siebenaler
Late Paleozoic Deformation In The Osgood Mountains And Dry Hills, Northern Nevada, Samuel A. Siebenaler
UNLV Theses, Dissertations, Professional Papers, and Capstones
Pennsylvanian (IP) and Permian (P) deposits (Etchart Formation) and structures in the northern Osgood Mountains and Dry Hills are identified and interpreted to reconstruct a late Paleozoic tectonic history for the time between the Antler and Sonoma orogenies. Mapping, field observations, fusulinid-based unit ages, and structural analysis are used to identify three fold and fault sets, a fault set, a fold set, and at least two angular unconformities. The faults consist of N to S striking normal faults (fault set 1) that are cross cut by WSW-ENE striking thrust faults (fault set 2). Fault sets 1 and 2 are cross …
Characterization Of Unsaturated Flow In Dual-Porosity Granular Media, Jeevan A. Jayakodilage
Characterization Of Unsaturated Flow In Dual-Porosity Granular Media, Jeevan A. Jayakodilage
UNLV Theses, Dissertations, Professional Papers, and Capstones
A geological medium made up of uncemented coarse porous rock fragments may be described as a “dual-porosity granular medium” due to the presence of two types of pores; small pores within individual fragments and large pores between the fragments. Crushed stone found in heap leach piles, mine waste, backfills, rock drains, and engineered capillary barrier systems fit this description. Unsaturated flow in a dualporosity granular medium will occur both through the fragments (matrix flow), and on the fragment surfaces (film flow). The relative influence of gravity and capillary forces on these two flow regimes will be largely different. Therefore, unsaturated …
Effect Of Spatial And Temporal Variability Of Antecedent Moisture Content On Model-Generated Runoff From An Arid Watershed, William J. Meyer
Effect Of Spatial And Temporal Variability Of Antecedent Moisture Content On Model-Generated Runoff From An Arid Watershed, William J. Meyer
UNLV Theses, Dissertations, Professional Papers, and Capstones
Streams in the arid southwest are typically ephemeral, and stream gages are not commonly available. Consequently, runoff data from storm events is not available, and flood control facility design or other water resource related decisions are based on synthetic hydrographs. In the Mojave Desert region of Southern Nevada, the duration of storm used to develop these synthetic hydrographs is the 6 hour storm. The 6 hour storm is used to simulate high intensity summer storms. Additionally, soils information used in the calculations for these synthetic hydrographs is taken from maps that are generally developed for a broad range of issues …
Sequence And Chemostratigraphy Of The Middle Cambrian Succession In Nevada And Utah, Robyn A. Howley
Sequence And Chemostratigraphy Of The Middle Cambrian Succession In Nevada And Utah, Robyn A. Howley
UNLV Theses, Dissertations, Professional Papers, and Capstones
The House Range Embayment of western Utah and eastern Nevada was a prominent topographic feature on the passive margin of western North America during the middle and late Cambrian. In this study, detailed documentation of sequence boundaries, and their intervening sequences across a platform-to-basin transect of the House Range Embayment was used to establish a sequence-stratigraphic framework from which the depositional history of the embayment was deciphered. This framework was then used to test the hypothesis that the House Range Embayment formed by tectonic subsidence. In addition, the chemostratigraphic (δ13Ccarb) record across the embayment was analyzed within this framework to …
The Dependence Of Electrical Resistivity, Saturation And Saturation Exponent On Multi-Phase Flow Instability, Zuolin Liu
The Dependence Of Electrical Resistivity, Saturation And Saturation Exponent On Multi-Phase Flow Instability, Zuolin Liu
All Theses
Multiphase flow channeling in oil reservoirs during water floods reduces oil recovery. Electrical methods may be used to monitor reservoirs and detect the onset of channeling, but the dependence of electrical resistivity on reservoir flow conditions is complex. The present study is directed toward understanding how the parameters of Archie's law, a commonly assumed relationship between electrical resistivity and water saturation in a porous medium, depends on multiphase flow instability leading to flow channeling. In this research a series of 34 flow experiments were conducted in a thin, two-dimensional tank (55cm x 55cm x 3.75cm) packed with 2mm glass beads …
A Synthetic Analysis Of Integrated Data Fusion: Combining Hydrologic And Geophysical Data Collected During A Tracer Test To Estimate Aquifer Flow And Transport Parameters, Dylan Fowler
All Theses
Integrated data fusion (IDF), also known as coupled inversion, is becoming a more widely used method for estimating hydrologic parameters from geophysical data. IDF is being used in this research as an approach to inversion that couples mathematical models of groundwater flow, solute transport, and electrical resistivity for the direct estimation of hydraulic conductivity, porosity, and dispersivity from transient resistivity data collected during a tracer test. In this work, synthetic field resistivity data are generated using only a single current electrode pair and many potential electrodes. This data is then used within the IDF framework to a) estimate hydraulic conductivity …
Evaluation Of A Pilot-Scale Constructed Wetland Treatment System For Renovation Of A Specific Oilfield Produced Water For Beneficial Use, Jennifer Horner
Evaluation Of A Pilot-Scale Constructed Wetland Treatment System For Renovation Of A Specific Oilfield Produced Water For Beneficial Use, Jennifer Horner
All Theses
Oilfield produced waters (OPWs) are brought to the surface when oil reservoirs contained in water-bearing geologic units are extracted. Large volumes of OPW present environmental challenges concerning disposal, as well as potential opportunities for beneficial use if constituents posing risk can be remediated. In this study a pilot-scale constructed wetland treatment system (CWTS) was specifically designed to treat an OPW from sub-Saharan Africa for use in irrigation and livestock watering. Three major objectives were to: characterize and identify constituents of concern in the OPW in terms of beneficial use, evaluate treatment performance of a pilot-scale constructed wetland treatment system for …
Identification Of Patterns And Controls Of The Distribution Of Groundwater Discharge To Streams, Curtis Gebhard
Identification Of Patterns And Controls Of The Distribution Of Groundwater Discharge To Streams, Curtis Gebhard
All Theses
Groundwater discharge is a key component in understanding the interaction between groundwater and surface water. It provides baseflow to streams and can transport nutrients and contaminants to related aquatic ecosystems. It can also influence fish behaviour, spawning, migration and provide areas of refuge during summer and winter months. There are a variety of techniques that are used to characterize the magnitude of groundwater discharge including seepage meters, field permeameters, and piezometers and manometers, however the controls for the magnitude and distribution of discharge remain poorly understood. The purpose of this study was to conduct field investigations complimented with numerical analysis …
Pilot-Scale Constructed Wetland Treatment System For Ammonia Removal From Oil-Field Produced Water, Yun Song
Pilot-Scale Constructed Wetland Treatment System For Ammonia Removal From Oil-Field Produced Water, Yun Song
All Theses
This investigation examined the feasibility of using free-water surface constructed wetland systems (CWTSs) to decrease the ammonia concentration in oil-field produced water. The objective of this research was to design constructed wetland experiments to determine specific conditions that decrease aqueous ammonia concentrations in simulated oilfield produced water. The design of these experiments was based on biogeochemical pathways of nitrification and denitrification. The experiments included three scales: bench-scale, single-cell, and pilot-scale. Bench-scale reactors contained wetland plants (Typha latifolia) and hydrosoil in 5-gallon buckets. Single wetland cells were constructed by adding hydrosoil and plants (T. latifolia and Schoenoplectus californicus) to 70-gallon containers. …
The Distribution And Comparative Biogeochemistry Of Silver With Other Selected Trace Metals In Coastal Waters Near Massachusetts, Usa, Christian F. Krahforst
The Distribution And Comparative Biogeochemistry Of Silver With Other Selected Trace Metals In Coastal Waters Near Massachusetts, Usa, Christian F. Krahforst
Graduate Doctoral Dissertations
Water samples and hydrologic data were collected during 1994-1996 in New England coastal waters near Massachusetts, USA to examine the distribution of silver and other trace metals (Cu, Pb, Cd, Zn, and Fe) in the coastal systems of Massachusetts and Cape Cod Bays. These investigations were designed to test the hypothesis that silver could serve as a tracer of dispersion of municipal wastewater in Boston Harbor into Massachusetts and Cape Cod Bays and estimate the relative contribution of wastewater discharge to the overall silver budget of the Massachusetts Bays system. Silver concentrations in both particulate and filtered (<0.4 µm) fractions averaged 103 and 117 pmol kg-1 for Boston Harbor, 34 and 10 pmol kg-1 in western Massachusetts Bay, and 11 and 7 pmol kg-1 in the central portion of Massachusetts Bay, respectively. Average Ag concentrations in southern Gulf of Maine coastal waters were 10 and 2 pmol kg-1 for filtered and particulate fractions, respectively. While nearly half of the silver existed in particulate form in Boston Harbor, nearly 80% of the silver in Massachusetts and Cape Cod Bays occurred in the filterable fraction. Coastal water surveys revealed non-conservative Ag behavior and probably the result of incomplete mixing of three or more water masses with unique Ag signatures (e.g., Merrimack River, Boston Harbor, surface and intermediate Gulf of Maine waters). Quasi-steady state mass balance approaches estimate most of the silver entering into the Massachusetts Bays system during the study period was the result of municipal wastewater discharge to Boston Harbor (84-93%).
Multivariate analyses …
0.4>Effect Of Mica Content On Surface Infiltration Of Soils In Northwestern Kern County, California, Steven Keyes Stakland
Effect Of Mica Content On Surface Infiltration Of Soils In Northwestern Kern County, California, Steven Keyes Stakland
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
A soils infiltration rate (IR) is the measured rate that soil is able to absorb water, either from precipitation or irrigation. A low IR can cause damage to crops if the necessary amount of water cannot penetrate to the plant roots in the time needed. The damage can be common in permanent plantings such as almond and pistachio orchards where regular tillage is avoided. This indicates a physical aspect to the problem because tillage increases IR. However, there is also an electrochemical side to infiltration problems because certain calcium surfactant treatments can increase IR. Various other methods have been used …
Stable Isotopes Of Fossil Teeth Corroborate Key General Circulation Model Predictions For The Last Glacial Maximum In North America, Matthew J. Kohn, Moriah Mckay
Stable Isotopes Of Fossil Teeth Corroborate Key General Circulation Model Predictions For The Last Glacial Maximum In North America, Matthew J. Kohn, Moriah Mckay
Geosciences Faculty Publications and Presentations
Oxygen isotope data provide a key test of general circulation models (GCMs) for the Last Glacial Maximum (LGM) in North America, which have otherwise proved difficult to validate. High δ18O pedogenic carbonates in central Wyoming have been interpreted to indicate increased summer precipitation sourced from the Gulf of Mexico. Here we show that tooth enamel δ18O of large mammals, which is strongly correlated with local water and precipitation δ18O, is lower during the LGM in Wyoming, not higher. Similar data from Texas, California, Florida and Arizona indicate higher δ18O values than in the Holocene, which is also predicted by GCMs. …
Recent Uplift Of The Burica Peninsula, Panama And Costa Rica, Recorded By Marine Terraces, Daniel Davidson
Recent Uplift Of The Burica Peninsula, Panama And Costa Rica, Recorded By Marine Terraces, Daniel Davidson
Earth and Environmental Geosciences Student Honors Theses
Deformation and uplift of the Burica Peninsula along the Panama-Costa Rica border results from eastward migration of the Panama Triple Junction (PTJ); the boundary between three tectonic plates. As the triple junction migrates to the southeast at ~55 mm/yr along the Middle America Trench (MAT), the Panama Fracture Zone (PFZ), separating the Cocos and Nazca plates, subducts under the Panama microplate. Differences in the thickness of the plates across the PFZ, as well as the rate and angle of subduction between the Cocos and Nazca plates, cause the Panama microplate to step up and over the Cocos plate. A flight …
Testing Mechanisms Of Subduction Zone Segmentation And Seismogenesis With Slip Distributions From Recent Andean Earthquakes, John P. Loveless, M. E. Pritchard, K. Kukowski
Testing Mechanisms Of Subduction Zone Segmentation And Seismogenesis With Slip Distributions From Recent Andean Earthquakes, John P. Loveless, M. E. Pritchard, K. Kukowski
Geosciences: Faculty Publications
A long-standing goal of subduction zone earthquake studies is to determine whether or not there are physical processes that control seismogenesis and the along-strike segmentation of the megathrust. Studies of individual earthquakes and global compilations of earthquakes find favorable comparison between coseismic interplate slip distributions and several different long-lived forearc characteristics, such as bathymetry, coastline morphology, crustal structure, and interplate frictional properties, but no single explanation seems to govern the location and slip distribution of all earthquakes. One possible reason for the lack of a unifying explanation is that the inferred earthquake parameters, most importantly the slip distribution, calculated in …
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
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 …
Morphological Specification Of Chinianella Scheympflugi Hofmann, 1994, A Late Jurassic (?Earliest Cretaceous) Dasycladalean Alga Of The Western Tethyan Domain, Felix Schlagintweit
Morphological Specification Of Chinianella Scheympflugi Hofmann, 1994, A Late Jurassic (?Earliest Cretaceous) Dasycladalean Alga Of The Western Tethyan Domain, Felix Schlagintweit
Studia UBB Geologia
The dasycladalean alga Chinianella? scheympflugi was described by Hofmann (1994) from the Tithonian of the Ernstbrunn Limestone of Lower Austria. This alga, so far unreported besides its type-locality, is reported from the Late Jurassic of Poland, the Northern Calcareous Alps of Austria, Crimea (Ukraine), and Greece (Parnassos Zone). Facies are well-agitated outer platform habitats (peri-reefal and back-reefal facies). The cylindrical thallus consists of three parts: a sterile Salpingoporella-like basal part (stalk), a fertile Chinianella-type main portion and a short sterile top part. The transition from the stalk to the main thallus portion is well marked and abrupt. The stratigraphic range …