Computational Approaches To Understanding Subduction Zone Geodynamics, Surface Heat Flow, And The Metamorphic Rock Record,
2022
Boise State University
Computational Approaches To Understanding Subduction Zone Geodynamics, Surface Heat Flow, And The Metamorphic Rock Record, Buchanan C. Kerswell
Boise State University Theses and Dissertations
Pressure-temperature (PT) estimates from exhumed high-pressure (HP) metamorphic rocks and global surface heat flow observations evidently encode information about subduction zone thermal structure and the nature of mechanical and chemical processing of subducted materials along the interface between converging plates. Previous work demonstrates the possibility of decoding such geodynamic information by comparing numerical geodynamic models with empirical observations of surface heat flow and the metamorphic rock record. However, ambiguous interpretations can arise from this line of inquiry with respect to thermal gradients, plate coupling, and detachment and recovery of subducted materials. This dissertation applies a variety of computational techniques to …
A Conservative Numerical Scheme For The Multilayer Shallow Water Equations,
2022
Clemson University
A Conservative Numerical Scheme For The Multilayer Shallow Water Equations, Evan Butterworth
All Theses
An energy-conserving numerical scheme is developed for the multilayer shallow water equations (SWE’s). The scheme is derived through the Hamiltonian formulation of the inviscid shallow water flows related to the vorticity-divergence variables. Through the employment of the skew-symmetric Poisson bracket, the continuous system for the multilayer SWE’s is shown to preserve an infinite number of quantities, most notably the energy and enstrophy. An energy-preserving numerical scheme is then developed through the careful discretization of the Hamiltonian and the Poisson bracket, ensuring the skew-symmetry of the latter. This serves as the groundwork for developing additional schemes that preserve other conservation properties …
Characterization And Evolution Of The Professor Valley Pennsylvanian Salt Body (Paradox Basin, Ut) Using Gravity And Magnetotellurics,
2022
The University of Texas at El Paso
Characterization And Evolution Of The Professor Valley Pennsylvanian Salt Body (Paradox Basin, Ut) Using Gravity And Magnetotellurics, Derek Scott
Open Access Theses & Dissertations
Syndepositional halokinetic movement of the Pennsylvanian Paradox Formation in the Paradox Basin, UT & CO behaved as a control over the development of depositional systems during the Late Paleozoic and early Mesozoic periods (Trudgill, 2011). Understanding the controls on halokinetic evolution in the area serves as an invaluable outcrop analogue for similar subsurface salt bodies in petroleum-bearing basins and provides key insights for hydrocarbon exploration in salt basins world wide. Professor Valley, located 15 miles Northeast of Moab, UT is situated between the Fisher Valley (Onion Creek) and Cache/Salt Valley salt walls. It includes an anomalous, isolated 0.5 km² outcrop …
Quantitative Analysis Of The Maximum Rate And Minimum Duration For A 200 Km Stepwise Retreat Of The Bindschadler Ice Stream At ~11.5 Cal Kyr Bp,
2022
Louisiana State University
Quantitative Analysis Of The Maximum Rate And Minimum Duration For A 200 Km Stepwise Retreat Of The Bindschadler Ice Stream At ~11.5 Cal Kyr Bp, Matthew E Kratochvil
LSU Master's Theses
Small-scale morainal ridges on the middle continental shelf of the Whales Deep Basin partly record the rapid opening of a 200-km grounding line embayment slightly after ~11.5 cal kyr BP. The overlapping pattern of backstepped moraines indicates that the grounding line oscillated back and forth during the retreat. Published sediment fluxes were combined with new sediment volume mapping of the moraines to infer the rates at which the grounding line retreated. The analyses indicate that the rates of grounding line retreat on the eastern flank of the embayment ranged from ~490 m a-1 to 1,300 m a-1. …
Seismic Inversion And Modeling For Improving Earthquake Hazard Assessment,
2022
Louisiana State University and Agricultural and Mechanical College
Seismic Inversion And Modeling For Improving Earthquake Hazard Assessment, Rasheed Ajala
LSU Doctoral Dissertations
The substantial research and the uncertain timeline to achieve deterministic earthquake prediction make the ground-shaking estimation of realistic earthquake scenarios a helpful approach in seismic hazard assessment. The accuracy of these computations depends on having structural subsurface models with good representations of sedimentary basins, fault zones, and crustal heterogeneity. We develop higher resolution seismic models for the Coachella Valley in Southern California and Indo-Burma. These areas have rising populations, expanding infrastructure, and highly anticipated disruptive earthquakes. We utilize data from recent seismic deployments and newly developed seismic imaging algorithms and the techniques of travel time tomography, wave propagation simulation, and …
Gps Observations Of Subsidence In South Louisiana Over Seasonal And Sub-Seasonal Timescales Associated With Hydrologic Loading,
2022
Louisiana State University and Agricultural and Mechanical College
Gps Observations Of Subsidence In South Louisiana Over Seasonal And Sub-Seasonal Timescales Associated With Hydrologic Loading, Nicholas Schuler
LSU Master's Theses
Louisiana’s primary environmental concern is arguably coastal wetland loss due to high subsidence rates, previously estimated to range from 1-14 mm/yr across much of the coast. Spatially and temporally varying strong short-term and seasonal components of deformation associated with changes in hydrologic loading throughout the year can give information about the elastic properties of the shallow crust, having implications for better understanding long-term subsidence trends across the region. Therefore, we quantify and characterize vertical deformation that occurs on annual to sub-annual timescales across southeast Louisiana. Vertical deformation is evaluated using publicly available daily GPS positions from 2016–2020 at 16 stations …
Comparing Satellite Vs Marine Potential Fields Data Over The Bathymetrists Seamounts,
2022
University of Nebraska - Lincoln
Comparing Satellite Vs Marine Potential Fields Data Over The Bathymetrists Seamounts, Alexa Fernandez, Irina Filina
UNL Student Research Days Posters, Graduate
The Bathymetrists Seamounts (BSM) are located north of the Sierra Leone Rise (SLR) in the mid-Atlantic Ocean. The seamounts reside on oceanic crust that is 105 to 45 million years old. However, dredging over the Bathymetrists Seamounts dated rocks at ~40 Myr. The general trend of the seamounts contradicts the eastward motion of the African tectonic plate. The origin and tectonic history of the Bathymetrists Seamounts remains debated in literature. Potential fields (gravity and magnetic) data can provide important insight into the formation and evolution of the seamounts. The purpose of this study is to compare available gravity and magnetic …
Processing Seismic, Gravity And Magnetic Data Over Diebold
Knoll On Juan De Fuca Plate,
2022
University of Nebraska-Lincoln
Processing Seismic, Gravity And Magnetic Data Over Diebold Knoll On Juan De Fuca Plate, Md Ariful Islam, Irina Filina
UNL Student Research Days Posters, Graduate
The Juan de Fuca plate is subducting beneath the North American plate along the Cascadia Subduction Zone. The CSZ is associated with multiple earthquakes, although compared to other subduction zones, it is less active. Many studies suggest that subduction will cause major mega thrust earthquake in near future, while others oppose this view. This project is focused on the Diebold Knoll on the JdF plate Various geophysical methods will be integrated to determine its origin and tectonic history.
A Robust Age Model For The Cryogenian Pocatello Formation Of Southeastern Idaho (Northwestern Usa) From Tandem In Situ And Isotope Dilution U-Pb Dating Of Volcanic Tuffs And Epiclastic Detrital Zircons,
2022
Boise State University
A Robust Age Model For The Cryogenian Pocatello Formation Of Southeastern Idaho (Northwestern Usa) From Tandem In Situ And Isotope Dilution U-Pb Dating Of Volcanic Tuffs And Epiclastic Detrital Zircons, Vincent H. Isakson, Mark D. Schmitz, Carol M. Dehler, Francis A. Macdonald, W. Adolph Yonkee
Geosciences Faculty Publications and Presentations
Tandem in situ and isotope dilution U-Pb analysis of zircons from pyroclastic volcanic rocks and both glacial and non-glacial sedimentary strata of the Pocatello Formation (Idaho, northwestern USA) provides new age constraints on Cryogenian glaciation in the North American Cordillera. Two dacitic tuffs sampled within glacigenic strata of the lower diamictite interval of the Scout Mountain Member yield high-precision chemical abrasion isotope dilution U-Pb zircon eruption and depositional ages of 696.43 ± 0.21 and 695.17 ± 0.20 Ma. When supplemented by a new high-precision detrital zircon maximum depositional age of ≤ 670 Ma for shoreface and offshore sandstones unconformably overlying …
Systematic Integration Of Applications Into The Surface Biology And Geology (Sbg) Earth Mission Architecture Study,
2022
California Institute of Technology
Systematic Integration Of Applications Into The Surface Biology And Geology (Sbg) Earth Mission Architecture Study, Christine M. Lee, Nancy F. Glenn, E. Natasha Stavros, Jeff Luvall, Karen Yuen, Stephanie Schollaert Uz
Geosciences Faculty Publications and Presentations
The Surface Biology and Geology (SBG) concept is the first National Aeronautics and Space Administration (NASA) Earth mission to develop and implement systematic integration of science application needs at the architecture study stage. Prior NASA mission concept and planning activities presumed that science measurement needs would encompasss application measurement needs and so did not explicitly evaluate and include applications at this stage. However, the effort presented here identified, documented and integrated application needs that would not have been included by considering research science needs only. First, a low latency of no greater than 24 hr was identified as the optimal …
Observations On The Stress Related Variations Of Soil Radon Concentration In The Gulf Of Corinth, Greece,
2022
National Observatory of Athens
Observations On The Stress Related Variations Of Soil Radon Concentration In The Gulf Of Corinth, Greece, Vassilios K. Karastathis, George Eleftheriou, Menas Kafatos, Kanaris Tsinganos, G-Akis Tselentis, Evangelos Mouzakiotis, Dimitar Ouzounov
Mathematics, Physics, and Computer Science Faculty Articles and Research
Our observations indicate a characteristic pattern in the long-term variation of soil radon concentrations, which seems to be consistent with the expected variation of regional stress in relation to seismicity. However, it seems that the major changes in radon level begin before the rock rapture, i.e. before the earthquake occurs. These conclusions have emerged after long-term observations with continuous and thorough real-time gamma-radiation monitoring in the seismically active area of the Gulf of Corinth, Greece. The recordings acquired close to a hot spring were of very high quality, implying that the deep hydraulic flow can possibly play a key role …
Potassic Volcanism Induced By Mantle Upwelling Through A Slab Window: Evidence From Shear Wave Splitting Analyses In Central Java,
2022
Missouri University of Science and Technology
Potassic Volcanism Induced By Mantle Upwelling Through A Slab Window: Evidence From Shear Wave Splitting Analyses In Central Java, Fansheng Kong, Stephen S. Gao, Kelly H. Liu, Jiabiao Li
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
To delineate the mantle flow fields in the vicinity of a previously proposed slab window and the possible roles that they may play in the formation of potassic volcanism in Central Java, we conduct shear wave splitting analyses using both local S and teleseismic XKS waves (including SKS, SKKS, and PKS) recorded by 121 onshore stations and two ocean bottom seismometers (OBSs). The XKS fast orientations from the OBSs are trench normal and in accord with previous subslab anisotropy measurements. In the eastern part of Central Java, the XKS and local S fast orientations from the onshore stations are mostly …
Continental Break-Up Under A Convergent Setting: Insights From P Wave Radial Anisotropy Tomography Of The Woodlark Rift In Papua New Guinea,
2022
Missouri University of Science and Technology
Continental Break-Up Under A Convergent Setting: Insights From P Wave Radial Anisotropy Tomography Of The Woodlark Rift In Papua New Guinea, Youqiang Yu, Frederik Tilmann, Dapeng Zhao, Stephen S. Gao, Kelly H. Liu
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
To explore the dynamic mechanism of continental rifting within a convergent setting, we determine the first P wave radial anisotropic tomography beneath the Woodlark rift in southeastern Papua New Guinea, which develops within the obliquely colliding zone between the Australian and southwest Pacific plates. The rift zone is depicted as localized low-velocity anomalies with positive radial anisotropy, which rules out a dominant role of active mantle upwelling in promoting the rift development and favors passive rifting with decompression melting as main processes. Downwelling slab relics in the upper mantle bounding the rift zone are revealed based on observed high-velocity anomalies …
Simulation Of Infrasonic Acoustic Wave Imprints On Airglow Layers During The 2016 M7.8 Kaikoura Earthquake,
2022
Embry-Riddle Aeronautical University
Simulation Of Infrasonic Acoustic Wave Imprints On Airglow Layers During The 2016 M7.8 Kaikoura Earthquake, P. A. Inchin, J. Aguilar Guerrero, J. B. Snively, Y. Kaneko
Publications
Simulations of hypothesized but unobserved mesopause airglow (MA) disturbances generated by infrasonic acoustic waves (IAWs) during the 2016 M7.8 Kaikoura earthquake are performed. Realistic surface displacements are calculated in a forward seismic wave propagation model and incorporated into a 3-D nonlinear compressible neutral atmosphere model as a source of IAWs at the surface-air interface. Inchin et al. (2021), https://doi.org/10.1029/2020av000260 previously showed that Global Positioning System-based total electron content (TEC) observations can be used to constrain the finite-fault kinematics of the Kaikoura earthquake. However, due to limitations of Global Navigation Satellite System network coverage and coalescence of nonlinear IAW fronts, they …
Evidence For Short Temporal Atmospheric Variations Observed By Infrasonic Signals: 1. The Troposphere,
2022
Southern Methodist University
Evidence For Short Temporal Atmospheric Variations Observed By Infrasonic Signals: 1. The Troposphere, G. Averbuch, M. Ronac-Giannone, S. Arrowsmith, J. F. Anderson
Geosciences Faculty Publications and Presentations
Infrasound monitoring is used in the forensic analysis of events, studying the physical processes of sources of interest, and probing the atmosphere. The dynamical nature of the atmosphere and the use of infrasound as a forensic tool lead to the following questions; (1) what is the timescale of atmospheric variability that affects infrasonic signals? (2) how do infrasound signals vary as a function of time? This study addresses these questions by monitoring a repetitive infrasound source and its corresponding tropospheric returns 54 km away. Source-receiver empirical Green's functions are obtained every 20 s and used to demonstrate the effect of …
Developing A Soil Column System To Measure Hydrogeophysical Properties Of Unconsolidated Sediment,
2022
Boise State University
Developing A Soil Column System To Measure Hydrogeophysical Properties Of Unconsolidated Sediment, Taylor Bienvenue, Jing Xie, Qifei Niu
Geosciences Faculty Publications and Presentations
Geophysical methods have been increasingly used to characterize the Earth's critical zone (CZ) and monitor hydrological processes occurring within it. For a quantitative interpretation, geophysical studies of CZ materials are necessary, and thus require more sophisticated laboratory setups. In this study, we develop a hydrogeophysical soil column system to measure key hydraulic and electrical properties of regolith in CZs. The developed soil column system consists of two components: (a) a novel hydrogeophysical probe that measures pore water pressure and electrical potential in soils and (b) a cylindrical cell to hold soil samples. The system can be arranged to perform both …
Toward The Understanding Of The 2018 Arnold, Ne Earthquake Cluster: Relocation Of Hypocenters And Establishment Of New Gravity Base Stations,
2022
University of Nebraska-Lincoln
Toward The Understanding Of The 2018 Arnold, Ne Earthquake Cluster: Relocation Of Hypocenters And Establishment Of New Gravity Base Stations, Kris Guthrie
Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research
In 2018, 27 unexpected earthquakes occurred in central Nebraska near Arnold. These earthquakes have no readily apparent cause and no evidence of the responsible fault system is seen at the surface. A joint analysis of vintage, regional gravity and magnetic datasets before the first earthquake revealed a lineament that could represent a pre-existing fault system. New high resolution potential fields data are needed to confidently map the subsurface features around the cluster. To design a survey and collect the data, the following tasks need to be addressed: [1] The earthquakes’ hypocenters need to be improved (relocated) to increase the efficiency …
Prediction Of Soil Water Content And Electrical Conductivity Using Random Forest Methods With Uav Multispectral And Ground-Coupled Geophysical Data,
2022
Missouri University of Science and Technology
Prediction Of Soil Water Content And Electrical Conductivity Using Random Forest Methods With Uav Multispectral And Ground-Coupled Geophysical Data, Yunyi Guan, Katherine R. Grote, Joel Schott, Kelsi Leverett
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
The volumetric water content (VWC) of soil is a critical parameter in agriculture, as VWC strongly influences crop yield, provides nutrients to plants, and maintains the microbes that are needed for the biological health of the soil. Measuring VWC is difficult, as it is spatially and tempo-rally heterogeneous, and most agricultural producers use point measurements that cannot fully capture this parameter. Electrical conductivity (EC) is another soil parameter that is useful in agricul-ture, since it can be used to indicate soil salinity, soil texture, and plant nutrient availability. Soil EC is also very heterogeneous; measuring EC using conventional soil sampling …
Predicting Seismic Site Coefficients For Northeast Arkansas (Nea) By Performing Site Specific Ground Motion Response Analysis (Ssgmra),
2022
Arkansas State University
Predicting Seismic Site Coefficients For Northeast Arkansas (Nea) By Performing Site Specific Ground Motion Response Analysis (Ssgmra), Md Radiue Islam
Student Theses and Dissertations
Northeast Arkansas (NEA) has a deep deposition of soil overlying the bedrock. The code-based design approach e.g., the American Association of State Highway and Transportation Officials (AASHTO) does not account for deep deposition of soil overlying the bedrock. As a result, structures with short-period spectral accelerations are overdesigned at significant cost, and structures with long-period spectral accelerations are under-designed at significant risk. The purpose of this study is to perform SSGMRA for areas in NEA and predict seismic site factors. Seismic hazard analyses have been carried out, and one dimensional (1D) site response analysis has been performed for seven different …
Incorporating Microtopography In A Land Surface Model And Quantifying The Effect On The Carbon Cycle,
2022
Boise State University
Incorporating Microtopography In A Land Surface Model And Quantifying The Effect On The Carbon Cycle, J. D. Graham, D. M. Ricciuto, N. F. Glenn, P. J. Hanson
Geosciences Faculty Publications and Presentations
Northern peatlands are a terrestrial carbon store, with an annual sink of 0.1 Pg C yr−1 and a total storage estimate of 547 Pg C. Northern peatlands are also major contributors of atmospheric methane. Most land surface models do not accurately represent peatland carbon emissions, partly because they do not represent the hydrologic cycle and/or microtopography adequately. Interactions between water table depth and microtopography in peatlands influence decomposition and modulate CO2 and CH4 fluxes. A modified version of the land surface component of the Energy Exascale Earth System Model, was recently created to represent the microtopography and …
