Mesopause Airglow Disturbances Driven By Nonlinear Infrasonic Acoustic Waves Generated By Large Earthquakes,
2020
Embry-Riddle Aeronautical University
Mesopause Airglow Disturbances Driven By Nonlinear Infrasonic Acoustic Waves Generated By Large Earthquakes, P. A. Inchin, J. B. Snively, J. Aguilar Guerrero, M. D. Zettergren, A. Williamson, D. Melgar
Publications
Near-epicentral mesopause airglow perturbations, driven by infrasonic acoustic waves (AWs) during a nighttime analog of the 2011 M9.1 Tohoku-Oki earthquake, are simulated through the direct numerical computation of the 3D nonlinear Navier-Stokes equations. Surface dynamics from a forward seismic wave propagation simulation, initialized with a kinematic slip model and performed with the SPECFEM3D_GLOBE model, are used to excite AWs into the atmosphere from ground level. Simulated mesopause airglow perturbations include steep oscillations and persistent nonlinear depletions up to 50% and 70% from the background state, respectively, for the hydroxyl OH(3,1) and oxygen O(1S) 557.7-nm emissions. Results suggest that …
Delineating Subsurface Karst Potential Using Electrical Resistivity In The Shell Mountain Province, Fort Hood Military Installation, Texas,
2020
Stephen F Austin State University
Delineating Subsurface Karst Potential Using Electrical Resistivity In The Shell Mountain Province, Fort Hood Military Installation, Texas, Annie Robison
Electronic Theses and Dissertations
Fort Hood Military Installation is located within the Lampasas Cut Plain in Bell and Coryell counties, Texas, and is characterized by exposures of Lower Cretaceous Trinity and Fredericksburg Group carbonates. The Shell Mountain Province is an elevated plateau located in western Fort Hood utilized by the military for heavy mechanical (troop and wheeled) maneuver training and hosts significant surficial and subsurface karst. Ongoing karst inventories in western Fort Hood conducted by range managers have documented over 100 individual karst features. Recent studies utilizing LiDAR and remote sensing techniques delineated karst potential in this area and identified over 13,909 discrete depressions. …
On The Seismic Performance Of Skewed Special Moment Frame Reduced Beam Section Connections,
2020
University of Arkansas, Fayetteville
On The Seismic Performance Of Skewed Special Moment Frame Reduced Beam Section Connections, Damaso Daniel Dominguez
Graduate Theses and Dissertations
Special Moment Frames (SMFs) are frequently used in high seismic areas for architecturally constrained designs, as they provide lateral system stiffness without the use of braces which often obstruct views and architectural features. Reduced beam section (RBS) connections are popular SMF connection details developed following the Northridge earthquake to limit brittle fractures within connection welds. Current American Institute of Steel Construction (ASIC) provisions (i.e. AISC 341-16) provide prequalified SMF RBS connection details (including welding requirements); however, all prequalified details only consider orthogonal connections between the beam and column. This dissertation investigates the effect of adding skew within SMF RBS connections …
Development Of Vs Profiles And Site Periods In The Mexico City Basin,
2020
University of Arkansas, Fayetteville
Development Of Vs Profiles And Site Periods In The Mexico City Basin, Landon Joel Woodfield
Graduate Theses and Dissertations
This study presents dynamic site characterization measurements at 25 sites within the Mexico City Basin. The primary focus of the testing was along the western edge of the Mexico City Basin. At each site, active source Multi-channel Analysis of Surface Waves (MASW) arrays and passive source Microtremor Array Measurements (MAM) L-arrays and circular arrays were used to acquire dispersion data. Horizontal to Vertical Spectral Ratio (HVSR) data was collected to determine site periods at each location. These experimental dispersion data and site periods were fit using a joint inversion of Rayleigh and Love wave dispersion data and HVSR site period …
What In Tarnation? Monitoring Animal Entrapments At The Rozel Tar Seeps,
2020
Westminster College, Salt Lake City
What In Tarnation? Monitoring Animal Entrapments At The Rozel Tar Seeps, Mary Sanchez, Cayla Martin, Jaimi Butler, David Kimberly, Foad Yousef
Utah Space Grant Consortium
The Great Salt Lake (GSL) is one of the largest migratory stops for many species of birds in North America. At Rozel Point, along the banks of the Great Salt Lake, there are tar seeps where some species of birds have gotten entrapped and died. These petroleum seeps are both naturally occurring and human created. The temperature that the seeps become sticky, the possibility of prey animals drawing predators in, and the appearance of the tar seeps are all important aspects of why birds are drawn to these seeps. Using motion sensor cameras and temperature monitoring devices, the animals that …
Geology And Geophysics Of The Mogollon Mining District And The Bearwallow Mountain 7.5 Minute Quadrangle, Catron County, New Mexico,
2020
Missouri State University
Geology And Geophysics Of The Mogollon Mining District And The Bearwallow Mountain 7.5 Minute Quadrangle, Catron County, New Mexico, Charles Frost Hoffman
Graduate Theses/Dissertations
The Mogollon Mining District and the Bearwallow Mountain 7.5-minute quadrangle are located in southwestern New Mexico, and are comprised of mid-Tertiary volcanic rocks that were the result of voluminous eruptions within the Mogollon-Datil Volcanic Field. This thesis aims to better understand the geology and structure of the Bearwallow Mountain 7.5-minute quadrangle and the Mogollon Mining District, and to analyze the use of Very Low Frequency electromagnetic techniques to delineate buried structures in volcanic terranes. I use Very Low Frequency electromagnetic methods and field mapping to evaluate the effectiveness of the method, and to better understand the geology and ore bodies …
Joint Inversion Of Gpr And Er Data,
2020
Boise State University
Joint Inversion Of Gpr And Er Data, Diego Domenzain
Boise State University Theses and Dissertations
Imaging the subsurface can shed knowledge on important processes needed in a modern day human's life such as ground-water exploration, water resource monitoring, contaminant and hazard mitigation, geothermal energy exploration and carbon dioxide storage. As computing power expands, it is becoming ever more feasible to increase the physical complexity of Earth's exploration methods, and hence enhance our understanding of the subsurface.
We use non-invasive geophysical active source methods that rely on electromagnetic fields to probe the depths of the Earth. In particular, we use Ground penetrating radar (GPR) and Electrical resistivity (ER). Both methods are sensitive to electrical conductivity while …
Rayleigh-Wave Multicomponent Crosscorrelation-Based Estimation Of Phase Velocities And Ambient Seismic Source Distributions,
2020
Boise State University
Rayleigh-Wave Multicomponent Crosscorrelation-Based Estimation Of Phase Velocities And Ambient Seismic Source Distributions, Zongbo Xu
Boise State University Theses and Dissertations
One uses seismic interferometry (SI) to recover Green’s functions (i.e. impulse response) from ambient seismic recordings and estimate surface-wave phase velocities to investigate subsurface structure. This method has been commonly used in the last 20 years because this method only utilizes ambient seismic recordings from seismic stations/sensors and does not rely on traditional seismic sources (e.g. earthquakes or active sources). SI assumes that the ambient seismic wavefield is isotropic, but this assumption is rarely met in practice. We demonstrate that, with linear-array spatial sampling of an anisotropic ambient seismic wavefield, SI provides a better estimate of Rayleigh-wave phase velocities than …
Archaeological, Geophysical, And Geospatial Analysis At David Crockett Birthplace State Park, In Upper East Tennessee,
2020
East Tennessee State University
Archaeological, Geophysical, And Geospatial Analysis At David Crockett Birthplace State Park, In Upper East Tennessee, Reagan Cornett
Electronic Theses and Dissertations
A geophysical survey was conducted at David Crockett Birthplace State Park (40GN205, 40GN12) using ground-penetrating radar (GPR) and magnetometry. The data indicated multiple levels of occupation that were investigated by Phase II and Phase III archaeological excavations. New cultural components were discovered, including the remnants of a Protohistoric Native American structure containing European glass trade beads and Middle Woodland artifacts that suggest trade with Hopewell groups from Ohio. A circular Archaic hearth was uncovered at one meter below surface and similar deep anomalies were seen in the GPR data at this level. A semi-automated object-based image analysis (OBIA) was implemented …
Stacking The Odds For Better Gpr: An Antenna Comparison,
2020
East Tennessee State University
Stacking The Odds For Better Gpr: An Antenna Comparison, Montana Kruske
Electronic Theses and Dissertations
Ground penetrating radar (GPR) is limited by depth penetration and signal-to-noise ratio (SNR), impacting the ability to resolve subsurface features. Stacking, a process of averaging multiple scans in the same location, improves SNR. Digital antennas are capable of stacking at much higher rates than analog antennas. Four sites were examined using a GSSI SIR-4000 GPR unit with a 400 MHz analog antenna and a 350 MHz digital “hyperstacking” (350 HS) antenna. Sites represent various soil conditions, with known features. Data were compared qualitatively and quantitatively for differences in antenna outputs. Visual inspection of radargrams indicate a reduction in noise in …
Core And Geophysical Analysis Of Biogenic Tufa Deposits In The Spring River In Northern Arkansas,
2020
Missouri State University
Core And Geophysical Analysis Of Biogenic Tufa Deposits In The Spring River In Northern Arkansas, Tyler W. Engelbart
Graduate Theses/Dissertations
The Spring River is fed by Mammoth Spring, a large spring on the Missouri-Arkansas border which produces roughly 240 million gallons of water per day (MGD). In this area there are deposits that appear as dams which cause water to pool upstream. Aerial analysis of the dams shows that there are approximately 100 of these features present in the first 45 miles downstream of Mammoth Spring. These deposits, known as tufa, are not uncommon in a karstic area of a spring fed river, but these are more frequent farther downriver than near the mouth of the spring. Preliminary mapping data …
Understanding Ice Mixtures Under Pluto Simulated Conditions And Their Implications For Geophysical Processes,
2020
University of Arkansas, Fayetteville
Understanding Ice Mixtures Under Pluto Simulated Conditions And Their Implications For Geophysical Processes, Caitlin Joannah Ahrens
Graduate Theses and Dissertations
New Horizons at Pluto has given the planetary science community the first images of Pluto’s surface, including geologic wonders and compositional variability. Methane, nitrogen, and carbon monoxide make up the bulk of the volatile plutonian surface along with water ice. In this work, these three main volatiles are specifically investigated in the laboratory setting to understand the spectral properties and behavior of binary and ternary mixtures. The spectra are taken in the near-infrared wavelengths (1 – 2.5 µm) using Fourier transform infrared (FTIR) spectroscopy techniques utilizing the Pluto Simulation Chamber housed at the University of Arkansas, which can reach conditions …
An Isotopic Assessment Of Late Prehistoric Interregional Warfare In The Southcentral Us,
2020
University of Arkansas, Fayetteville
An Isotopic Assessment Of Late Prehistoric Interregional Warfare In The Southcentral Us, John R. Samuelsen
Graduate Theses and Dissertations
Skull burials are found all over the world. The cause of such ancient Native Americans deposits often lead to disagreement among scholars torn between warfare and ancestor veneration. One skull-and-mandible deposit, representing at least 352 people (A.D. 1253-1399), was uncovered at the Crenshaw site, a multiple-mound Caddo ceremonial center in southwest Arkansas. Most previous research suggested they were victims of interregional warfare from the Southern Plains or Mississippi Valley. One previous study hypothesized that this was a Caddo burial practice which expanded during the Middle Caddo period (A.D. 1200-1500) due to the adoption of maize as a staple and a …
Arc‐Type Magmatism Due To Continental‐Edge Plowing Through Ancient Subduction‐Enriched Mantle,
2020
Utrecht University
Arc‐Type Magmatism Due To Continental‐Edge Plowing Through Ancient Subduction‐Enriched Mantle, Douwe J.J. Van Hinsbergen, Wim Spakman, Hugo De Boorder, Michiel Van Dongen, Simon M. Jowitt, Paul R.D. Mason
Geoscience Faculty Research
The puzzling... (See article for full abstract).
An Analysis Of The Reactivation Potential Of A Deep-Seated Landslide In The Oregon Coast Range Under Varying Hydrologic Conditions With Seismic Triggering,
2020
Portland State University
An Analysis Of The Reactivation Potential Of A Deep-Seated Landslide In The Oregon Coast Range Under Varying Hydrologic Conditions With Seismic Triggering, Emily E. Smoot
Anthós
Landslides can occur in many locations across the world and have the potential to be extremely destructive if failures occur near populated areas. Failures are most likely to occur on slopes that have already experienced numerous failures. This means they are a considerable hazard, and the risk involved with building in areas that have previously experienced landslides should be adequately understood. This study examines the reactivation potential of a deep-seated landslide located in the Oregon Coast Range. The analysis of this landslide included creating a map of the surface morphology and computing the factor of safety for the deposit using …
Nonlinear Least Squares 3-D Geolocation Solutions Using Time Differences Of Arrival,
2020
University of New Mexico
Nonlinear Least Squares 3-D Geolocation Solutions Using Time Differences Of Arrival, Michael V. Bredemann
Mathematics & Statistics ETDs
This thesis uses a geometric approach to derive and solve nonlinear least squares minimization problems to geolocate a signal source in three dimensions using time differences of arrival at multiple sensor locations. There is no restriction on the maximum number of sensors used. Residual errors reach the numerical limits of machine precision. Symmetric sensor orientations are found that prevent closed form solutions of source locations lying within the null space. Maximum uncertainties in relative sensor positions and time difference of arrivals, required to locate a source within a maximum specified error, are found from these results. Examples illustrate potential requirements …
Testing A Drone-Based Magnetic Field Surveying System,
2020
University of Nebraska-Lincoln
Testing A Drone-Based Magnetic Field Surveying System, Erik Jacobson, Irina Filina
UCARE: Research Products
Aeromagnetic surveys are conducted by geoscientists to study subsurface geologic structures, such as faults. This type of survey uses a magnetometer mounted upon an airborne vehicle to collect magnetic field data. Magnetic anomalies are caused by variations in subsurface geology, namely in magnetic properties of subsurface rocks. Jacobson and Filina (2019) reported on the development of a new low cost drone, based magnetic field surveying system by the UNL Geophysics Team. This drone-based magnetic system is capable of collecting high resolution data at low speeds and low altitudes. The current study focuses on testing this system by conducting two flights …
A Geophysical Survey Near Blacktail Creek In The Thompson Park Area Near Butte, Montana,
2020
Montana Tech
A Geophysical Survey Near Blacktail Creek In The Thompson Park Area Near Butte, Montana, Guolong Wu
Graduate Theses & Non-Theses
Subsurface electrical information can be obtained by electrical and self-potential methods. These geophysical methods, compared to drilling, provide a much cheaper option for investigating the hydrogeological setting. In this project report, we carried out resistivity and self-potential survey along Blacktail Creek in the Thompson Park area near Butte, Montana to understand the hydrogeological setting.
Three geophysical methods have been used: 2D electrical resistivity, 3D electrical resistivity, and self-potential. The least-square inversion resistivity model results showed a general variation of resistivity with depth and delineated the extent of the ground water. The ERT results show three electrical layers, one of them …
Characterization Of Magma Storage And Dynamics At Akutan, Semisopochnoi, And Okmok Volcanoes From Analytical And Numerical Models Of Geodetic, Seismic, And Petrologic Data,
2020
Southern Methodist University
Characterization Of Magma Storage And Dynamics At Akutan, Semisopochnoi, And Okmok Volcanoes From Analytical And Numerical Models Of Geodetic, Seismic, And Petrologic Data, Kimberly Degrandpre
Earth Sciences Theses and Dissertations
Volcanic eruptions can cause significant socioeconomic loss, but a better understanding of the processes and dynamics influencing the evolution of volcanic plumbing systems will advance the development of eruption forecasting models that will ultimately mitigate hazards and risks associated with eruptive events. Geologic and geophysical data must be integrated in 3D, finite- element, multiphysical, numerical models to define the coupled evolution of magmatic and crustal stress regimes in volcanic environments, but in data limited regions this is not always an option. The remote nature of the Aleutian Island Arc restricts ground-based monitoring and sampling efforts, and due to sparse temporal …
Feel The Vibration! Measuring The Ground Motion Caused By Racecars At The Zmax Dragway,
2020
University of South Carolina - Columbia
Feel The Vibration! Measuring The Ground Motion Caused By Racecars At The Zmax Dragway, Gabrielle Herrin
Senior Theses
Dragsters raced down a 1,000 ft track at the zMAX Dragway and the resulting ground motion was recorded, analyzed, and displayed live to fans. At the NGK Spark Plugs NHRA Four-Wide Nationals on April 26 – 28, 2019 and the NTK NHRA Carolina Nationals on October 11-13, 2019 the ground motion was recorded with novel devices anchored on the track walls. The devices were fit with Raspberry Pis, precise clocks, and accelerometers recording at 400 samples per second. In April, the geometry of the devices was located near the start line and in October, devices were anchored to the outside …
