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Articles 181 - 210 of 2451

Full-Text Articles in Geophysics and Seismology

Response Of Open Volcanic Systems To Static Stress Changes, Aimee Zimmerman Jan 2024

Response Of Open Volcanic Systems To Static Stress Changes, Aimee Zimmerman

Dissertations, Master's Theses and Master's Reports

Large earthquakes of magnitude 7.0 or greater can alter volcanic emissions and even trigger eruptions at nearby volcanoes. The stress changes imparted by large earthquakes can cause otherwise stable conditions within the magmatic system to be disturbed, potentially inducing volcanic activity. The extent of the triggering potential is still unknown due to insufficient understanding of the mechanisms involved. We model static stress changes for 174 earthquake-volcano pairs from 2000-2023 at volcanoes within 500 km, computing changes in both the normal stress perpendicular to the direction of horizontal maximum stress and dilatational strain. We then use thermal satellite data to measure …

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Thermochronology And Exhumation Dynamics Of Metamorphic Units In The Salmon River Suture Zone, Jonathan J. Cone Jan 2024

Thermochronology And Exhumation Dynamics Of Metamorphic Units In The Salmon River Suture Zone, Jonathan J. Cone

Graduate Theses/Dissertations

The Salmon River suture zone in western Idaho records the Jurassic-Cretaceous (160-90 Ma) accretion of amalgamated volcanic arc terranes onto the North American continent. Rocks exposed at the surface record burial to depths of more than 20 kilometers, with unclear drivers for uplift and exhumation. Two competing hypotheses have been proposed to explain the transport of deep crustal rocks to the surface: (1) delamination of a dense lithospheric root resulted in rapid isostatic uplift of the crust and (2) exhumation of crustal blocks along thrust faults. To test these models, I present temperature-time (T-t) paths for mid-crustal metamorphic rocks constructed …

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Geology Of The Bishop 7.5-Minute Quadrangle And Geophysical Modeling To Constrain Syndepositional Deformation Of The Black Warrior Foreland Basin, Joseph Edward Lane Jan 2024

Geology Of The Bishop 7.5-Minute Quadrangle And Geophysical Modeling To Constrain Syndepositional Deformation Of The Black Warrior Foreland Basin, Joseph Edward Lane

Graduate Theses/Dissertations

The Black Warrior basin is a foreland basin formed by the Ouachita–Appalachian orogeny during the late Paleozoic Era. Mississippian strata record the transition from the carbonate platform within the Tuscumbia Limestone to the clastic-rich units within the overlying Pride Mountain Formation and Hartselle Sandstone. The western and southern-most fringes of the Black Warrior basin are covered by thin, post orogenic Cretaceous sediments of the East Gulf Coastal Plain. Geological mapping of the Bishop 7.5-Minute quadrangle revealed subtle deformation in Mississippian strata in the form of gentle folds (

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Advances In Machine Learning Aided Seismic Interpretation And Inversion For Subsurface Characterization, Tobi Micheal Ore Jan 2024

Advances In Machine Learning Aided Seismic Interpretation And Inversion For Subsurface Characterization, Tobi Micheal Ore

Graduate Theses, Dissertations, and Problem Reports (ETD)

Geophysical data are used to “remotely sense” the subsurface to illuminate structures, stratigraphy, and features that are of interest in the exploration for energy, suitable storage for carbon dioxide, geothermal development, and environmental considerations. The interpretations of these data typically are regarded as partially an art, as it depends on the experience of the interpreter. This is further exacerbated with the big data era as this data is large and takes several days, even longer, to manually interpret. To bridge this gap of speed and subjective bias, machine learning has been successfully applied to automate the geophysical interpretation process. This …

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Integration Of 3d Structural Modelling And Well Logging Analysis In The Evaluation Of October Oil Field, Gulf Of Suez, Egypt, Lamiaa Yahia, Mostafa Toni, Farouk I. Metwalli, M. H. Mansour, Amir Ismail Jan 2024

Integration Of 3d Structural Modelling And Well Logging Analysis In The Evaluation Of October Oil Field, Gulf Of Suez, Egypt, Lamiaa Yahia, Mostafa Toni, Farouk I. Metwalli, M. H. Mansour, Amir Ismail

Trends in advanced sciences and technology

An extensive study of the NUBIA and MAT reservoirs, incorporating numerous data sources, enhances the accuracy of production forecasts for hydrocarbon exploration and development. This study aims to integrate seismic and well data for re-assessment and to delineate the geological and petrophysical characteristics of the October oil field which is one of the most productive in the central Gulf of Suez, but it has recently witnessed a drop in output in some regions, and some wells have begun to depletion. While facies modeling enabled the spatial distribution of lithologic facies inside the constructed 3D structural model, which reflected two types …

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Modeling Earthquake Catalog (1985-2022) In Northern Egypt Using Space-Time Epidemic-Type Aftershock Sequences (Etas), Mariam Ramadan, Amir Ismail, Amin E. Khalil, Hesham Abdelhafiez, Nouran S. Salama Jan 2024

Modeling Earthquake Catalog (1985-2022) In Northern Egypt Using Space-Time Epidemic-Type Aftershock Sequences (Etas), Mariam Ramadan, Amir Ismail, Amin E. Khalil, Hesham Abdelhafiez, Nouran S. Salama

Trends in advanced sciences and technology

Earthquakes have the largest damaging effects among natural disasters on a global scale. Efforts for reducing their effects have taken place for a long time. The prediction of earthquakes was the main target, however the studies conducted were not successful. As a replacement, seismic hazard assessments were adopted to predict the levels of ground motion for the possible future large earthquakes. This approach is probabilistic in nature that rely on the quality of earthquake catalog. The probabilistic model adopted is built on the assumption that the events in the earthquake catalog are random Poisson distribution, assuming that events are independent …

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Simulation Of Wave Propagation In Granular Particles Using A Discrete Element Model, Syed Tahmid Hussan Jan 2024

Simulation Of Wave Propagation In Granular Particles Using A Discrete Element Model, Syed Tahmid Hussan

College of Graduate Studies: Theses & Dissertations

The understanding of Bender Element mechanism and utilization of Particle Flow Code (PFC) to simulate the seismic wave behavior is important to test the dynamic behavior of soil particles. Both discrete and finite element methods can be used to simulate wave behavior. However, Discrete Element Method (DEM) is mostly suitable, as the micro scaled soil particle cannot be fully considered as continuous specimen like a piece of rod or aluminum. Recently DEM has been widely used to study mechanical properties of soils at particle level considering the particles as balls. This study represents a comparative analysis of Voigt and Best …

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Investigating The Viability Of Low Frequency Mhvsr Estimates Using Deep Shear Wave Velocity Profile, T. Mai, C. C. Nweke, P. Wang, F. J. Ornelas Jan 2024

Investigating The Viability Of Low Frequency Mhvsr Estimates Using Deep Shear Wave Velocity Profile, T. Mai, C. C. Nweke, P. Wang, F. J. Ornelas

Civil & Environmental Engineering Faculty Publications

Site response describes the alterations of seismic energy due to its interaction with subsurface geological interfaces and structures, which is usually estimated by one dimensional (1D) ground response analysis (GRA). However, 1D GRA requires subsurface information (e.g., shear wave velocity profile), which makes it not widely applicable, particularly for the sites where subsurface information is unavailable. Alternatively, the microtremor horizontal-to-vertical spectral ratio (mHVSR) from three-component recordings of ambient noise on the ground surface is easily measured and is believed to have the potential for site response prediction (the peaks in mHVSR are strongly associated with the site resonant frequencies). However,the …

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Modeling Apparent Pb Loss In Zircon U-Pb Geochronology, Glenn R. Sharman, Matthew A. Malkowski Jan 2024

Modeling Apparent Pb Loss In Zircon U-Pb Geochronology, Glenn R. Sharman, Matthew A. Malkowski

Geosciences Faculty Publications and Presentations

The loss of radiogenic Pb from zircon is known to be a major factor that can cause inaccuracy in the U–Pb geochronological system; hence, there is a need to better characterize the distribution of Pb loss in natural samples. Treatment of zircon by chemical abrasion (CA) has become standard practice in isotope dilution–thermal ionization mass spectrometry (ID-TIMS), but CA is much less commonly employed prior to in situ analysis via laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) or secondary ionization mass spectrometry (SIMS). Differentiating the effects of low levels of Pb loss in Phanerozoic zircon with relatively low-precision in situ U–Pb …

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Exploring Background Noise With A Large-N Infrasound Array: Waterfalls, Thunderstorms, And Earthquakes, L. T. Scamfer, J. F. Anderson Dec 2023

Exploring Background Noise With A Large-N Infrasound Array: Waterfalls, Thunderstorms, And Earthquakes, L. T. Scamfer, J. F. Anderson

Geosciences Faculty Publications and Presentations

Ambient infrasound noise contains an abundance of information that is typically overlooked due to limitations of typical infrasound arrays. To evaluate the ability of large-N infrasound arrays to identify weak signals hidden in background noise, we examine data from a 22-element array in central Idaho, USA, spanning 58 days using a standard beamforming method. Our results include nearly continuous detections of diverse weak signals from infrasonic radiators, sometimes at surprising distances. We observe infrasound from both local (8 km) and distant (195 km) waterfalls. Thunderstorms and earthquakes are also notable sources, with distant thunderstorm infrasound observed from ∼800 to 900 …

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Studying The Impact Of The Geospace Environment On Solar Lithosphere Coupling And Earthquake Activity, Dimitar Ouzounov, Galina Khachikyan Dec 2023

Studying The Impact Of The Geospace Environment On Solar Lithosphere Coupling And Earthquake Activity, Dimitar Ouzounov, Galina Khachikyan

Mathematics, Physics, and Computer Science Faculty Articles and Research

In solar–terrestrial physics, there is an open question: does a geomagnetic storm affect earthquakes? We expand research in this direction, analyzing the seismic situation after geomagnetic storms (GMs) accompanied by the precipitation of relativistic electrons from the outer radiation belt to form an additional radiation belt (RB) around lower geomagnetic lines. We consider four widely discussed cases in the literature for long-lived (weeks, months) RBs due to GMs and revealed that the 1/GMs 24 March 1991 with a new RB at L~2.6 was followed by an M7.0 earthquake in Alaska, 30 May 1991, near footprint L = 2.69; the 2/GMs …

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Transport And Mixing Of Water Masses Across The Southeast Caribbean Ocean Imaged By Seismic Reflection Data, Joseph Renzaglia Dec 2023

Transport And Mixing Of Water Masses Across The Southeast Caribbean Ocean Imaged By Seismic Reflection Data, Joseph Renzaglia

Earth Sciences Theses and Dissertations

The Caribbean Sea serves as a major pathway for global thermohaline circulation (THC), which is a complex and vital component of the Earth’s climate system, influencing global heat distribution and oceanic circulation. Though relatively stratified, it is the boundary layer that distributes mass and temperature between the surface waters and the deep ocean where we observe various multiscale mixing processes from mesoscale to fine-scale. In regions where bathymetry is shallower and mechanical mixing forces, such as winds and tides, are more dominant, diapycnal diffusivity is typically stronger, driving vertical mixing. This type of mixing occurs at small scales, typically as …

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How Low Can You Go?: Widespread Challenges In Measuring Low Stream Discharge And A Path Forward, Erin C. Seybold, Anna Bergstrom, C. Nathan Jones, Amy J. Burgin, Sam Zipper, Sarah E. Godsey, Walter K. Dodds, Margaret A. Zimmer, Margaret Shanafield, Thibault Datry, Raphael D. Mazor, Mathis L. Messager, Julian D. Olden, Adam Ward, Songyan Yu, Kendra E. Kaiser, Arial Shogren, Richard H. Walker Dec 2023

How Low Can You Go?: Widespread Challenges In Measuring Low Stream Discharge And A Path Forward, Erin C. Seybold, Anna Bergstrom, C. Nathan Jones, Amy J. Burgin, Sam Zipper, Sarah E. Godsey, Walter K. Dodds, Margaret A. Zimmer, Margaret Shanafield, Thibault Datry, Raphael D. Mazor, Mathis L. Messager, Julian D. Olden, Adam Ward, Songyan Yu, Kendra E. Kaiser, Arial Shogren, Richard H. Walker

Geosciences Faculty Publications and Presentations

Low flows pose unique challenges for accurately quantifying streamflow. Current field methods are not optimized to measure these conditions, which in turn, limits research and management. In this essay, we argue that the lack of methods for measuring low streamflow is a fundamental challenge that must be addressed to ensure sustainable water management now and into the future, particularly as climate change shifts more streams to increasingly frequent low flows. We demonstrate the pervasive challenge of measuring low flows, present a decision support tool (DST) for navigating best practices in measuring low flows, and highlight important method developmental needs.

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Subduction Initiation Recorded In The Dadeville Complex Of Alabama And Georgia, Southeastern United States, Naomi A. Becker, Freya R. George, George L. Guice, James L. Crowley, Wendy R. Nelson, Joseph F. Browning-Hanson, Supratik Roy, Daniel R. Viete Dec 2023

Subduction Initiation Recorded In The Dadeville Complex Of Alabama And Georgia, Southeastern United States, Naomi A. Becker, Freya R. George, George L. Guice, James L. Crowley, Wendy R. Nelson, Joseph F. Browning-Hanson, Supratik Roy, Daniel R. Viete

Geosciences Faculty Publications and Presentations

The Dadeville Complex of Alabama and Georgia (southeastern United States) represents the largest suite of exposed mafic-ultramafic rocks in the southern Appalachians. Due to poor preservation, chemical alteration, and tectonic reworking, a specific tectonic origin for the Dadeville Complex has been difficult to deduce. We obtained new whole-rock and mineral geochemistry coupled with zircon U-Pb geochronology to investigate the magmatic and metamorphic processes recorded by the Dadeville Complex, as well as the timing of these processes. Our data reveal an up-stratigraphic evolution in the geochemistry of the volcanic rocks, from forearc basalts to boninites. Our new U-Pb zircon crystallization data—obtained …

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Geophysics-Informed Hydrologic Modeling Of A Mountain Headwater Catchment For Studying Hydrological Partitioning In The Critical Zone, Hang Chen, Qifei Niu, Aida Mendieta, John Bradford, James Mcnamara Dec 2023

Geophysics-Informed Hydrologic Modeling Of A Mountain Headwater Catchment For Studying Hydrological Partitioning In The Critical Zone, Hang Chen, Qifei Niu, Aida Mendieta, John Bradford, James Mcnamara

Geosciences Faculty Publications and Presentations

Hydrologic modeling has been a useful approach for analyzing water partitioning in catchment systems. It will play an essential role in studying the responses of watersheds under projected climate changes. Numerous studies have shown it is critical to include subsurface heterogeneity in the hydrologic modeling to correctly simulate various water fluxes and processes in the hydrologic system. In this study, we test the idea of incorporating geophysics-obtained subsurface critical zone (CZ) structures in the hydrologic modeling of a mountainous headwater catchment. The CZ structure is extracted from a three-dimensional seismic velocity model developed from a series of two-dimensional velocity sections …

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A Multidisciplinary Approach To Resolving The End-Guadalupian Extinction, Christopher R. Fielding, Scott E. Bryan, James L. Crowley, Tracy D. Frank, Michael T. Hren, Chris Mays, Stephen Mcloughlin, Jun Shen, Peter J. Wagner, Arne Winguth, Cornelia Winguth Dec 2023

A Multidisciplinary Approach To Resolving The End-Guadalupian Extinction, Christopher R. Fielding, Scott E. Bryan, James L. Crowley, Tracy D. Frank, Michael T. Hren, Chris Mays, Stephen Mcloughlin, Jun Shen, Peter J. Wagner, Arne Winguth, Cornelia Winguth

Geosciences Faculty Publications and Presentations

The transition from the middle to late Permian (Guadalupian–Lopingian) is claimed to record one or more extinction events that rival the ‘Big Five’ in terms of depletion of biological diversity and reorganization of ecosystem structure. Yet many questions remain as to whether the events recorded in separate regions were synchronous, causally related, or were of a magnitude rivaling other major crises in Earth's history. In this paper, we survey some major unresolved issues related to the Guadalupian–Lopingian transition and offer a multidisciplinary approach to advance understanding of this under-appreciated biotic crisis by utilizing records in Southern Hemisphere high-palaeolatitude settings. We …

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A Survey Of Non-Usgs Continuous Streamflow Gaging Networks In The Pacific Northwest, Kendra E. Kaiser, Kyle Blasch, Mcallister Hall Dec 2023

A Survey Of Non-Usgs Continuous Streamflow Gaging Networks In The Pacific Northwest, Kendra E. Kaiser, Kyle Blasch, Mcallister Hall

Geosciences Faculty Publications and Presentations

Extensive streamflow data sources exist beyond the largest streamflow data provider in the United States, the U.S. Geological Survey. We developed and distributed a survey to about 300 individuals and organizations that collect streamflow data across the Pacific Northwest (Idaho, Oregon, Washington). We received 100 responses with 56% of those sufficiently complete to include in the analysis. From these responses, there are about 2000 streamflow monitoring locations in the region beyond the USGS monitoring network. The duration of record for gages is related to the size of the streamflow gaging network, with small and large networks generally operating monitoring locations …

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The Surface Atmosphere Integrated Field Laboratory (Sail) Campaign, D. R. Feldman, A. C. Aiken, W. R. Boos, R. W. H. Carroll, V. Chandrasekar, S. Collis, J. M. Creamean, G. De Boer, J. Deems, P. J. Demott, J. Fan, A. N. Flores, D. Gochis, M. Grover, T. C. J. Hill, A. Hodshire, E. Hulm, C. C. Hume, R. Jackson, F. Junyent, A. Kennedy, M. Kumjian, E. J. T. Levin, J. D. Lundquist, J. O'Brien, M. S. Raleigh, J. Reithel, A. Rhoades, K. Rittger, W. Rudisill, Z. Sherman, E. Siirila-Woodburn, S. M. Skiles, J. N. Smith, R. C. Sullivan, A. Theisen, M. Tuftedal, A. C. Varble, A. Wiedlea, S. Wielandt, K. Williams, Z. Xu Dec 2023

The Surface Atmosphere Integrated Field Laboratory (Sail) Campaign, D. R. Feldman, A. C. Aiken, W. R. Boos, R. W. H. Carroll, V. Chandrasekar, S. Collis, J. M. Creamean, G. De Boer, J. Deems, P. J. Demott, J. Fan, A. N. Flores, D. Gochis, M. Grover, T. C. J. Hill, A. Hodshire, E. Hulm, C. C. Hume, R. Jackson, F. Junyent, A. Kennedy, M. Kumjian, E. J. T. Levin, J. D. Lundquist, J. O'Brien, M. S. Raleigh, J. Reithel, A. Rhoades, K. Rittger, W. Rudisill, Z. Sherman, E. Siirila-Woodburn, S. M. Skiles, J. N. Smith, R. C. Sullivan, A. Theisen, M. Tuftedal, A. C. Varble, A. Wiedlea, S. Wielandt, K. Williams, Z. Xu

Geosciences Faculty Publications and Presentations

The science of mountainous hydrology spans the atmosphere through the bedrock and inherently crosses physical and disciplinary boundaries: land–atmosphere interactions in complex terrain enhance clouds and precipitation, while watersheds retain and release water over a large range of spatial and temporal scales. Limited observations in complex terrain challenge efforts to improve predictive models of the hydrology in the face of rapid changes. The Upper Colorado River exemplifies these challenges, especially with ongoing mismatches between precipitation, snowpack, and discharge. Consequently, the U.S. Department of Energy’s (DOE) Atmospheric Radiation Measurement (ARM) user facility has deployed an observatory to the East River Watershed …

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Using Shallow Electromagnetic And Magnetic Techniques To Map Soil Texture And Characterize Salinity And Water Dynamics Below Pecan Orchards, El Paso County, Texas, Kristina Sasser Dec 2023

Using Shallow Electromagnetic And Magnetic Techniques To Map Soil Texture And Characterize Salinity And Water Dynamics Below Pecan Orchards, El Paso County, Texas, Kristina Sasser

Open Access Theses & Dissertations

Non-invasive, near surface geophysical tools provide a time efficient and cost-effective approach to study the shallow subsurface. Electromagnetic induction (EMI) instruments are a category of these near surface methods that provide spatial and temporal information (2-D to 4-D) about shallow (<6 m) subsurface properties, from which soil salinity, clay content, and water content can be estimated. However, deconstructing soil apparent electrical conductivity (ECa) from EMI methods into its component parts remains a challenge. This research uses EMI and magnetic geophysical techniques to: (1) compare and contrast the distribution and behavior of ECa, both spatially and temporally, at two flood irrigated agricultural sites (pecan orchards) with different soil layers, properties, and controls on electrical conductivities that lie within the same floodplain in far west Texas; and (2) develop a one-dimensional inversion model using ECa and soil texture data at specified layers from established sites of known high and low ECa to determine soil layer resistivities at various dates during the irrigation season. Data are compared to soil sensor bulk EC and volumetric water content data at corresponding depths to validate results. Soils at both sites exhibit large ECa contributions from textural controls, and irrigation frequency. The combination of these two controls dictate where and how quickly secondary minerals precipitate, clog soil pores, reduce infiltration, and salinize the groundwater. Insight from this research aids in ongoing efforts to characterize vadose zone hydrology in dryland critical zones with high infiltration and serves as a guide for locations where future soil sampling will occur.

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Uas-Based Quantification Of Dynamic Lahar Channel Morphology At Volcán De Fuego, Guatemala, Jerry Clay Mock Dec 2023

Uas-Based Quantification Of Dynamic Lahar Channel Morphology At Volcán De Fuego, Guatemala, Jerry Clay Mock

Boise State University Theses and Dissertations

Lahars are responsible for 26% of the deaths associated with volcanic activity reported since 1500 AD, and are extremely destructive to infrastructure (Thouret et al., 2020). Secondary lahars are volcanic mudflows commonly triggered by rainfall. Valuable land and buildings may be covered or destroyed by thick deposits including heavy boulders, mud, and debris. Bridges and roads can be washed out, cutting people off from vital services and potentially placing them in danger from other hazards. Volcán de Fuego in Guatemala actively produces pyroclastic material in small Strombolian eruptions every 15-20 minutes. Fuego occasionally has larger eruptions and has produced over …

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Investigating Seismicity And Structure Of The Pecos, Texas Region Of The Delaware Basin Using A Temporary Nodal Network, Jenna Lynn Faith Dec 2023

Investigating Seismicity And Structure Of The Pecos, Texas Region Of The Delaware Basin Using A Temporary Nodal Network, Jenna Lynn Faith

Open Access Theses & Dissertations

With increasing earthquakes in the Delaware Basin since 2009, earthquake studies, including accurate hypocenters, are critically needed in the Delaware Basin to identify the structures producing earthquakes, and to determine if they are related to unconventional petroleum development and production. In 2018, with funding from the Texas Seismological Network (TexNet), the University of Texas at El Paso deployed and maintained a nodal network of 25 Magseis Fairfield Z-Land Generation 2 5-Hz seismic nodes in the Pecos, Texas region of the Delaware Basin, known as The Pecos Array. The network was deployed from November 2018 until the beginning of January 2020, …

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Modeling The Peak Ground Acceleration And Assessing The Economic Loss And Casualty Due To Potential Earthquakes Of Various Magnitudes In The New Madrid Seismic Zone, Mahmud Afroz Dec 2023

Modeling The Peak Ground Acceleration And Assessing The Economic Loss And Casualty Due To Potential Earthquakes Of Various Magnitudes In The New Madrid Seismic Zone, Mahmud Afroz

Graduate Theses and Dissertations

The New Madrid Seismic Zone (NMSZ) is one of the active tectonic zones capable of producing big earthquakes in the southcentral USA. The objective of this study was to assess the economic losses and casualties that might be caused by various magnitudes of seismic events in the NMSZ. The manifestation is the estimation for each magnitude which is using the Peak Ground Acceleration (PGA) that might occur during an earthquake. It is calculated using an attenuation function that correlates the intensity of local ground movement, the earthquake magnitude, and the distance from its epicenter. The assessment of casualties was conducted …

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Examining The Spatial Periodicity Of Force Chains And Strain Localization In Polycrystal Models, Richard D. Panduro-Allanson Dec 2023

Examining The Spatial Periodicity Of Force Chains And Strain Localization In Polycrystal Models, Richard D. Panduro-Allanson

UNLV Theses, Dissertations, Professional Papers, and Capstones

Shear strain localization is typical in deforming rocks and is vital for developing faults and tectonic boundaries. There are various proposed drivers of shear localization (temperature, fluid, phase transformation, and microstructure); we will explore the effects of elastic heterogeneity (a microstructural influence) on shear localization in polycrystal models. Elastic heterogeneity can lead to varied stress states in material and drive shear localization. Previous simulations of elastically heterogeneous polycrystal models have shown that the stress distribution can be described as forming an anastomosing pattern of high-stress streams parallel to the compression direction. This anastomosing patterning resembles force chains; linear, high-stress features …

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Electrofacies Analysis Using A Geostatistical Approach, Northern Iraq Case Study, Hussein S. Hussein Nov 2023

Electrofacies Analysis Using A Geostatistical Approach, Northern Iraq Case Study, Hussein S. Hussein

Polytechnic Journal

The distribution of petrophysical parameters is governed by lithology, hence understanding the spatial variation in lithology is essential for reservoir characterisation. This study points out the use of well logs to estimate the lithology of carbonate rocks (limestone, marly limestone, dolomite, and dolomitic limestone) found in Upper Cretaceous to Miocene formations at the Khabbaz Oil Field in Northern Iraq. Applying the multivariate regression technique to neutron, and density data enabled accurate lithology prediction. By using independent values (well log data) to predict a dependent value (lithology), this technique is a progression of regression analysis. The formations under study comprised a …

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Evaluating 3 Decades Of Precipitation In The Upper Colorado River Basin From A High-Resolution Regional Climate Model, William Rudisill, Alejandro Flores, Rosemary Carroll Nov 2023

Evaluating 3 Decades Of Precipitation In The Upper Colorado River Basin From A High-Resolution Regional Climate Model, William Rudisill, Alejandro Flores, Rosemary Carroll

Geosciences Faculty Publications and Presentations

Convection-permitting regional climate models (RCMs) have recently become tractable for applications at multi-decadal timescales. These types of models have tremendous utility for water resource studies, but better characterization of precipitation biases is needed, particularly for water-resource-critical mountain regions, where precipitation is highly variable in space, observations are sparse, and the societal water need is great. This study examines 34 years (1987–2020) of RCM precipitation from the Weather Research and Forecasting model (WRF; v3.8.1), using the Climate Forecast System Reanalysis (CFS; CFSv2) initial and lateral boundary conditions and a 1 km × 1 km innermost grid spacing. The RCM is centered …

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Groundwater System Characterisation: Fortescue Alluvial Fan, Michael J. Donn, Olga V. Barron, Axel Suckow, Chris Turnadge, John A. Simons, Robert J. Paul, Christopher Schelfhout Dr Nov 2023

Groundwater System Characterisation: Fortescue Alluvial Fan, Michael J. Donn, Olga V. Barron, Axel Suckow, Chris Turnadge, John A. Simons, Robert J. Paul, Christopher Schelfhout Dr

Natural resources commissioned reports

This report focuses on groundwater system characterisation in the region north of Newman, based on analysis of pre-existing data and data newly acquired during project activities. Groundwater system characterisation was an important research component supporting the assessment of managed aquifer recharge opportunities, using mine dewatering surplus generated (due to mining below the watertable) at large BHP Billiton Iron Ore operations in the eastern Pilbara mining zone, and aiming to support irrigated agriculture. The assessment area is located north of Ethel Gorge and covers the Upper Fortescue River floodplain and surroundings. The project added much knowledge to this largely ‘data-poor’ region, …

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U–Pb Zircon Ages, Mapping, And Biostratigraphy Of The Payette Formation And Idaho Group North Of The Western Snake River Plain, Idaho: Implications For Hydrocarbon System Correlation, Renee L. Love, Reed S. Lewis, Spencer H. Wood, Dennis M. Feeney, Mark D. Schmitz Nov 2023

U–Pb Zircon Ages, Mapping, And Biostratigraphy Of The Payette Formation And Idaho Group North Of The Western Snake River Plain, Idaho: Implications For Hydrocarbon System Correlation, Renee L. Love, Reed S. Lewis, Spencer H. Wood, Dennis M. Feeney, Mark D. Schmitz

Geosciences Faculty Publications and Presentations

Sedimentary deposits north of the western Snake River Plain host Idaho’s first and only producing oil and gas field. They consist of the lower to middle Miocene Payette Formation, the middle to upper Miocene Poison Creek and Chalk Hills Formations, and the Pliocene to lower Pleistocene Glenns Ferry Formation. Using new geochronology, palynomorph biostratigraphy, and geologic mapping, we connect updip surface features to subsurface petroleum play elements. The Payette Formation is a likely main source of the hydrocarbons, and acts as one of the reservoirs in the unnamed basin. Here, we redefine the Payette Formation as 0 to ~3,500 ft …

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Astronomical And Tectonic Influences On Climate And Deposition Revealed Through Radioisotopic Geochronology And Bayesian Age-Depth Modeling Of The Early Eocene Green River Formation, Wyoming, Usa, Benjamin T. Bruck, Brad S. Singer, Mark D. Schmitz, Alan R. Carroll, Stephen Meyers, Andrew P. Walters, Brian R. Jicha Nov 2023

Astronomical And Tectonic Influences On Climate And Deposition Revealed Through Radioisotopic Geochronology And Bayesian Age-Depth Modeling Of The Early Eocene Green River Formation, Wyoming, Usa, Benjamin T. Bruck, Brad S. Singer, Mark D. Schmitz, Alan R. Carroll, Stephen Meyers, Andrew P. Walters, Brian R. Jicha

Geosciences Faculty Publications and Presentations

The Wilkins Peak Member (WPM) of the Green River Formation in Wyoming, USA, comprises alternating lacustrine and alluvial strata that preserve a record of terrestrial climate during the early Eocene climatic optimum. We use a Bayesian framework to develop age-depth models for three sites, based on new 40Ar/39Ar sanidine and 206Pb/238U zircon ages from seven tuffs. The new models provide two- to ten-fold increases in temporal resolution compared to previous radioisotopic age models, confirming eccentricity-scale pacing of WPM facies, and permitting their direct comparison to astronomical solutions. Starting at ca. 51 Ma, the median …

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Reducing Uncertainty In Sea-Level Rise Prediction: A Spatial-Variability-Aware Approach, Subhankar Ghosh, Shuai An, Arun Sharma, Jayant Gupta, Shashi Shekhar, Aneesh Subramanian Oct 2023

Reducing Uncertainty In Sea-Level Rise Prediction: A Spatial-Variability-Aware Approach, Subhankar Ghosh, Shuai An, Arun Sharma, Jayant Gupta, Shashi Shekhar, Aneesh Subramanian

I-GUIDE Forum

Given multi-model ensemble climate projections, the goal is to accurately and reliably predict future sea-level rise while lowering the uncertainty. This problem is important because sea-level rise affects millions of people in coastal communities and beyond due to climate change's impacts on polar ice sheets and the ocean. This problem is challenging due to spatial variability and unknowns such as possible tipping points (e.g., collapse of Greenland or West Antarctic ice-shelf), climate feedback loops (e.g., clouds, permafrost thawing), future policy decisions, and human actions. Most existing climate modeling approaches use the same set of weights globally, during either regression or …

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Snowpack Relative Permittivity And Density Derived From Near-Coincident Lidar And Ground-Penetrating Radar, Randall Bonnell, Daniel Mcgrath, Andrew R. Hedrick, Ernesto Trujillo, Tate G. Meehan, Keith Williams, Hans-Peter Marshall, Graham Sexstone, John Fulton, Michael J. Ronayne, Steven R. Fassnacht, Ryan Webb, Katherine E. Hale Oct 2023

Snowpack Relative Permittivity And Density Derived From Near-Coincident Lidar And Ground-Penetrating Radar, Randall Bonnell, Daniel Mcgrath, Andrew R. Hedrick, Ernesto Trujillo, Tate G. Meehan, Keith Williams, Hans-Peter Marshall, Graham Sexstone, John Fulton, Michael J. Ronayne, Steven R. Fassnacht, Ryan Webb, Katherine E. Hale

Geosciences Faculty Publications and Presentations

Depth-based and radar-based remote sensing methods (e.g., lidar, synthetic aperture radar) are promising approaches for remotely measuring snow water equivalent (SWE) at high spatial resolution. These approaches require snow density estimates, obtained from in-situ measurements or density models, to calculate SWE. However, in-situ measurements are operationally limited, and few density models have seen extensive evaluation. Here, we combine near-coincident, lidar-measured snow depths with ground-penetrating radar (GPR) two-way travel times (twt) of snowpack thickness to derive >20 km of relative permittivity estimates from nine dry and two wet snow surveys at Grand Mesa, Cameron Pass, and Ranch Creek, Colorado. …

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