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Full-Text Articles in Geophysics and Seismology
Revealing The Core Dynamics Of Vesta: Insights From Experimental Investigations Of Electrical Resistivity And Thermal Conductivity, Oluwasanmi A. Orole Mr
Revealing The Core Dynamics Of Vesta: Insights From Experimental Investigations Of Electrical Resistivity And Thermal Conductivity, Oluwasanmi A. Orole Mr
Electronic Thesis and Dissertation Repository
Insights from high pressure and temperature experiments involving in-situ measurements of the electrical resistivity of Fe-5wt%Ni at temperatures of up to 2000 K, under pressures of 2-5 GPa in a 1000-ton cubic-anvil press have been used to reveal Vesta’s core dynamics. The Wiedemann–Franz law was used to calculate the thermal conductivity from the measured electrical resistivity data. Comparing the findings of this study with prior investigations on both pure Fe and Fe-10wt%Ni indicates that an increase in Ni ranging from 0-10wt% has negligible effect on the electrical resistivity of Fe alloys. By comparing the range of estimated heat flux through …
Exploring The Effects Of Tree Roots On Infiltration Process, Nazife Onaral
Exploring The Effects Of Tree Roots On Infiltration Process, Nazife Onaral
Masters Theses
Effects of the root structures on soil infiltration dynamics are not clearly defined. Imaging the complex tree root structures and movement of water through the root ball is a challenging task to achieve without damaging the trees and roots by conventional methods. Commonly used methods are invasive, labor-intensive, and not easily accessible. Ground Penetrating Radar (GPR) has commonly been used to characterize soil profiles and it can be a reliable tool to map complex root structures with a novel high-resolution circular data collection technique. Electrical resistivity tomography (ERT) is another reliable geophysical method to image infiltration processes by the change …
Hydrothermal Alteration Targeting And Geophysical Mineral Exploration Of Eureka And Sylvanite Mining Districts, Southwest New Mexico, Kenneth Singh
Hydrothermal Alteration Targeting And Geophysical Mineral Exploration Of Eureka And Sylvanite Mining Districts, Southwest New Mexico, Kenneth Singh
Open Access Theses & Dissertations
As part of the southwestern North American porphyry copper province, mining of natural resources in New Mexico has historically played a crucial role in economic development for over 150 years including this project area in the Little Hatchet Mountains. The northern half of the Little Hatchet Mountains lies in Grant County and includes the Eureka Mining District (EMD) whereas the southern half is in Hidalgo County and includes the Sylvanite Mining District (SMD), 38 miles southeast of Lordsburg. The EMD, a copper and silver-lead mining district from 1880-1961, had a total estimated production from the Laramide veins of 2.9 million …
Electrical Resistivity Of Nickel, Iron And Iron-Silicon Alloy Melts At High Pressure With Implications For The Thermal Conductivity Of The Earth’S Core, Reynold E. Silber
Electrical Resistivity Of Nickel, Iron And Iron-Silicon Alloy Melts At High Pressure With Implications For The Thermal Conductivity Of The Earth’S Core, Reynold E. Silber
Electronic Thesis and Dissertation Repository
The Earth’s liquid outer core (OC) is composed of Fe alloyed with up to 10% Ni and a small fraction of light elements. However, the effect of light elements such as Si on the transport properties of liquid Fe-alloy in Earth’s OC is not clear. Thermal conductivity (κ) and related electrical resistivity (ρ) are the least constrained parameters in OC. Therefore, the characterization of transport properties of Ni, Fe and Fe-Si at high pressure has important geophysical implications for the Earth’s core. The ρ of solid and liquid Ni, Fe and Fe 4%Si was measured at …
Detection Of Bedrock Fractures And Joints Beneath Cover: Geophysical Approaches To An Engineering Geology Problem, Muthanna Yousif Yaqoob Aldiney
Detection Of Bedrock Fractures And Joints Beneath Cover: Geophysical Approaches To An Engineering Geology Problem, Muthanna Yousif Yaqoob Aldiney
Dissertations
This research used geophysical methods to detect the presence of sub-vertical failure planes, their direction(s), and their frequency in bedrock beneath soil or glacial drift overburden. Azimuthal measurements using the seismic, electrical resistivity (ER), and electromagnetic conductivity were made to evaluate which techniques might provide the best indication of the bedrock joints, faults, or shear zones. Measurements were made at multiple sites near each of three locations: Jackson, Alpena, and Grand Ledge, Michigan. The first two are former limestone quarries and the third is underlain by sandstone. Seismic measurements began with one or two linear refraction spreads, used to establish …
Seismic Refraction And Electrical Resistivity Tests For Fracture Induced Anisotropy In A Mountain Watershed, Aida Mendieta
Seismic Refraction And Electrical Resistivity Tests For Fracture Induced Anisotropy In A Mountain Watershed, Aida Mendieta
Boise State University Theses and Dissertations
The critical zone (CZ) is the earth’s layer where water, air, rock, and life meet. It is the zone with which humans interact most. The National Research council (2001) defines the CZ as a “heterogeneous, near surface environment in which complex interactions involving rock, soil, water, air, and living organisms regulate the natural habitat and determine the availability of life sustaining resources”. The CZ may extend roughly from the top of the vegetation canopy to the deepest part of the rock column where meteoric water circulates – this is often in the 10 – 30 m range. The upper 1-2 …
Characterizing Subsurface Void Spaces And Water Distribution And Flow Patterns In Cave Hill Karst Using Resistivity, Jacob A. Gochenour
Characterizing Subsurface Void Spaces And Water Distribution And Flow Patterns In Cave Hill Karst Using Resistivity, Jacob A. Gochenour
Senior Honors Projects, 2010-2019
Describing the distribution of groundwater is essential in understanding the evolution of geomorphologic features in karst topography. Electrical resistivity allows us to find a model of subsurface distribution of resistivity that enables the visual recognition of groundwater and void spaces. The purpose of this research is to implement electrical resistivity to describe the spatial relationship of groundwater and karstic features at Grand Caverns National Natural Landmark, Grottoes, Virginia. Two locations of interest, a karstic swale and sinkhole area, were identified for the deployment of electrical resistivity. Both, dipole-dipole and Schlumberger arrays were collected for each deployment. A total of ten …
Use Of Laboratory Geophysical And Geotechnical Investigation Methods To Characterize Gypsum Rich Soils, Raghava A. Bhamidipati
Use Of Laboratory Geophysical And Geotechnical Investigation Methods To Characterize Gypsum Rich Soils, Raghava A. Bhamidipati
Theses and Dissertations--Civil Engineering
Gypsum rich soils are found in many parts of the world, particularly in arid and semi-arid regions. Most gypsum occurs in the form of evaporites, which are minerals that precipitate out of water due to a high rate of evaporation and a high mineral concentration. Gypsum rich soils make good foundation material under dry conditions but pose major engineering hazards when exposed to water. Gypsum acts as a weak cementing material and has a moderate solubility of about 2.5 g/liter. The dissolution of gypsum causes the soils to undergo unpredictable collapse settlement leading to severe structural damages. The damages incur …
Deep Groundwater And Potential Subsurface Habitats Beneath An Antarctic Dry Valley, J. A. Mikucki, E. Auken, S. Tulaczyk, R. A. Virginia, C. Schamper, K. I. Sørensen, P. T. Doran, H. Dugan, N Foley
Deep Groundwater And Potential Subsurface Habitats Beneath An Antarctic Dry Valley, J. A. Mikucki, E. Auken, S. Tulaczyk, R. A. Virginia, C. Schamper, K. I. Sørensen, P. T. Doran, H. Dugan, N Foley
Dartmouth Scholarship
The occurrence of groundwater in Antarctica, particularly in the ice-free regions and along the coastal margins is poorly understood. Here we use an airborne transient electromagnetic (AEM) sensor to produce extensive imagery of resistivity beneath Taylor Valley. Regional- scale zones of low subsurface resistivity were detected that are inconsistent with the high resistivity of glacier ice or dry permafrost in this region. We interpret these results as an indication that liquid, with sufficiently high solute content, exists at temperatures well below freezing and considered within the range suitable for microbial life. These inferred brines are widespread within permafrost and extend …
Investigation Of Spatial And Temporal Processes Of Lake-Aquifer Interactions In The Nebraska Sand Hills, John T. Ong
Investigation Of Spatial And Temporal Processes Of Lake-Aquifer Interactions In The Nebraska Sand Hills, John T. Ong
Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research
Interaction between surface water and groundwater is an important component of the water cycle that affects the physicochemical and biological characteristics of lakes, streams, wetlands, and seacoasts. Due to the complex interaction of geologic, topographic, and hydrologic factors, flow between lakes and groundwater remains poorly understood. Evolution of conceptual models over the past 30 years describes processes of advection, dispersion, and free convection that occur in different lake flow regimes. Few detailed field studies document the validity of these conceptual models because of the difficulty of studying the subsurface and the prohibitive cost of instrumenting large areas. In the semi-arid …