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2023

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Articles 61 - 90 of 93

Full-Text Articles in Geophysics and Seismology

Critical Workforce Skills For Bachelor-Level Geoscientists: An Analysis Of Geoscience Job Advertisements, G. W. Shafer, K. Viskupic, A. E. Egger Apr 2023

Critical Workforce Skills For Bachelor-Level Geoscientists: An Analysis Of Geoscience Job Advertisements, G. W. Shafer, K. Viskupic, A. E. Egger

Geosciences Faculty Publications and Presentations

Understanding the skills bachelor-level geoscientists need to enter the workforce is critical to their success. The goal of this study was to identify the workforce skills that are most requested from a broad range of geoscience employers. We collected 3668 job advertisements for bachelor-level geoscientists and used a case-insensitive, code-matching function in Matlab to determine the skills geoscience employers seek. Written communication (67%), field skills (63%), planning (53%), and driving (51%) were most frequently requested. Field skills and data collection were frequently found together in the ads. Written communication skills were common regardless of occupation. Quantitative skills were requested less …


Tectonomagmatic Evolution Of Southwestern Laurentia: Insights From Zircon U-Pb Geochronology And Hafnium Isotopic Composition Of The Red Bluff Granite Suite, West Texas, Usa, Munazzam Ali Mahar, Philip C. Goodell, Jason W. Ricketts, Eric J. Kappus, James L. Crowley, Anthony M. Alvarez Apr 2023

Tectonomagmatic Evolution Of Southwestern Laurentia: Insights From Zircon U-Pb Geochronology And Hafnium Isotopic Composition Of The Red Bluff Granite Suite, West Texas, Usa, Munazzam Ali Mahar, Philip C. Goodell, Jason W. Ricketts, Eric J. Kappus, James L. Crowley, Anthony M. Alvarez

Geosciences Faculty Publications and Presentations

We provide laser ablation–multicollector–inductively coupled plasma–mass spectrometry (LA-MC-ICP-MS) and high-precision chemical abrasion–isotope dilution–thermal ionization mass spectrometry (CA-ID-TIMS) U-Pb ages and Hf isotopic compositions of zircons from the Red Bluff Granite Suite and mafic dikes in the Franklin Mountains of El Paso, Texas, USA. Granitoids exposed in the Franklin Mountains were previously divided into five magmatic stages based on cross-cutting relationships. Major and trace element compositions showed that these granitoids are ferroan, alkaline, and A2 type. Homogeneity in the whole-rock geochemistry suggests that the granite stages are genetically related and share similar petrogenetic histories. Weighted mean zircon 206Pb/238U …


Advances In Our Understanding Of Pyroclastic Current Behavior From The 1980 Eruption Sequence Of Mount St. Helens Volcano (Washington), Usa, Brittany D. Brand, Aaron A. Marshall Apr 2023

Advances In Our Understanding Of Pyroclastic Current Behavior From The 1980 Eruption Sequence Of Mount St. Helens Volcano (Washington), Usa, Brittany D. Brand, Aaron A. Marshall

Geosciences Faculty Publications and Presentations

This review summarizes what the volcanology community has learned thus far from studying the deposits of pyroclastic currents (PCs) from the 1980 eruption sequence at Mount St. Helens. The review includes mass flow events during the May 18 eruption, including the lateral blast, the afternoon column collapse and boil-over PC activity, and some aspects of the debris avalanche. We also include a summary of PCs generated in the smaller eruptions following the climactic May 18 event. Our objective is to summarize the state of our understanding of PC transport and emplacement mechanisms from the combination of field and laboratory observations, …


New Insights Into The Age And Origin Of Two Small Cretaceous Seamount Chains Proximal To The Northwestern Hawaiian Ridge, Arturo Sotomayor, Andrea Balbas, Kevin Konrad, Anthony A. P. Koppers, Jasper G. Konter, V. Dorsey Wanless, Thomas F. Hourigan, Christopher Kelley, Nicole Raineault Apr 2023

New Insights Into The Age And Origin Of Two Small Cretaceous Seamount Chains Proximal To The Northwestern Hawaiian Ridge, Arturo Sotomayor, Andrea Balbas, Kevin Konrad, Anthony A. P. Koppers, Jasper G. Konter, V. Dorsey Wanless, Thomas F. Hourigan, Christopher Kelley, Nicole Raineault

Geosciences Faculty Publications and Presentations

The Northwestern Hawaiian Ridge is an age-progressive volcanic chain sourced from the Hawaiian mantle plume. Proximal to the Northwestern Hawaiian Ridge are several clusters of smaller seamounts and ridges with limited age constraints and unknown geodynamic origins. This study presents new bathymetric data and 40Ar/39Ar age determinations from lava flow samples recovered by remotely operated vehicle (ROV) from two east–west-trending chains of seamounts that lie north of the Pūhāhonu and Mokumanamana volcanoes. The previously unexplored Naifeh Chain (28°48′N,167°48′W) and Plumeria Chain (25°36′N, 164°35′W) contain five volcanic structures each, including three guyots in the Naifeh Chain. New 40 …


Quantifying Oil And Gas Industry Related Geohazard Using Radar Interferometry And Hydro-Geomechanical Modeling, Weiyu Zheng Apr 2023

Quantifying Oil And Gas Industry Related Geohazard Using Radar Interferometry And Hydro-Geomechanical Modeling, Weiyu Zheng

Earth Sciences Theses and Dissertations

The Permian Basin, containing a large amount of oil and gas, has been intensively developed for hydrocarbon production. However, the hazards related to the oil and gas industry including surface deformation and the underlying mechanisms in this region have not been well known. My PhD study aims to monitor the geohazards in the Permian Basin and better comprehend the subsurface mechanisms with the aid of high-resolution and high-accuracy Interferometric Synthetic Aperture Radar (InSAR) images. Generally, as the pore pressure is influenced by wastewater injection/hydrocarbon production, the pressure changes can propagate to other surrounding underground and overlying rock/soil layers, resulting in …


Benthic Habitat Mapping Of Mountain Top Bank Within The Northern Gulf Of Mexico Through Integrated Geophysical And Visual Data Analysis, Bethany Pertain Mar 2023

Benthic Habitat Mapping Of Mountain Top Bank Within The Northern Gulf Of Mexico Through Integrated Geophysical And Visual Data Analysis, Bethany Pertain

Master's Theses

Mesophotic coral ecosystems (MCEs) are among the seafloor ecosystems that have been poorly studied throughout the world’s oceans, but they are a vital and diverse ecosystem that should be prioritized for future mapping and ecological studies. Priority should be given to them because they possess natural, social, and economic values, and face a variety of threats, all of which, if not better understood will result in the loss of this unique ecosystem. Insights into these ecosystems, among other deep-sea environments, are lacking due to difficulty accessing them, inherent lag between data collection by an autonomous system and observation by a …


Dynamic Mass Loss From Greenland's Marine-Terminating Peripheral Glaciers (1985–2018), Katherine E. Bollen, Ellyn M. Enderlin, Rebecca Muhlheim Feb 2023

Dynamic Mass Loss From Greenland's Marine-Terminating Peripheral Glaciers (1985–2018), Katherine E. Bollen, Ellyn M. Enderlin, Rebecca Muhlheim

Geosciences Faculty Publications and Presentations

Global glacier mass balance decreased rapidly over the last two decades, exceeding mass loss from the Greenland and Antarctic Ice Sheets. In Greenland, peripheral glaciers and ice caps (GICs) cover only ~5% of Greenland's area but contributed ~20% of the island's ice mass loss between 2000 and 2018. Although Greenland GIC mass loss due to surface meltwater runoff has been estimated using atmospheric models, mass lost to changes in ice discharge into oceans (i.e., dynamic mass loss) remains unquantified. We use the flux gate method to estimate discharge from Greenland's 585 marine-terminating peripheral glaciers between 1985 and 2018, and compute …


Lidar And Deep Learning Reveal Forest Structural Controls On Snowpack, Ahmad Hojatimalekshah, Joel Gongora, Josh Enterkine, Nancy F. Glenn, T. Trevor Caughlin, Hans-Peter Marshall, Christopher A. Hiemstra Feb 2023

Lidar And Deep Learning Reveal Forest Structural Controls On Snowpack, Ahmad Hojatimalekshah, Joel Gongora, Josh Enterkine, Nancy F. Glenn, T. Trevor Caughlin, Hans-Peter Marshall, Christopher A. Hiemstra

Geosciences Faculty Publications and Presentations

Forest structure has a strong relationship with abiotic components of the environment. For example, canopy morphology controls snow depth through interception and modifies incoming thermal radiation. In turn, snow water availability affects forest growth, carbon sequestration, and nutrient cycling. We investigated how structural diversity and topography affect snow depth patterns across scales. The study site, Grand Mesa, Colorado, is representative of many areas worldwide where declining snowpack and its consequences for forest ecosystems are increasingly an environmental concern. On the basis of a convolution neural network model (R2 of 0.64; root mean squared error of 0.13 m), we …


Sediment Transport And Geomorphological Evolution In The Northern Gulf Of Mexico, Kelli Moran Jan 2023

Sediment Transport And Geomorphological Evolution In The Northern Gulf Of Mexico, Kelli Moran

LSU Doctoral Dissertations

This dissertation explores the mechanisms driving sediment transport and deposition on the continental shelf and within the bays of the northern Gulf of Mexico via a suite of geophysical methods and sediment cores on a variety of timescales. This dissertation is comprised of three main chapters, each focusing on a different location, environment, and process but tied together using geophysical survey, a thematic focus on geomorphic change and sediment transport within the deltaic cycle and deltaic plain environments, and the implications this change poses for both past and future sediment transport and environmental change in response to sea level change. …


The Kanarra Fold-Thrust Structure - The Leading Edge Of The Sevier Fold-Thrust Belt, Southwestern Utah: Geology Of The Intermountain West, William J. Chandonia, John P. Hogan Jan 2023

The Kanarra Fold-Thrust Structure - The Leading Edge Of The Sevier Fold-Thrust Belt, Southwestern Utah: Geology Of The Intermountain West, William J. Chandonia, John P. Hogan

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The multiple origins proposed for the Kanarra anticline in southwestern Utah as a drag-fold along the Hurricane fault, a Laramide monocline, a Sevier fault-propagation fold, or a combination of these process­es, serve to muddy its tectonic significance. This in part reflects the structural complexity of the exposed eastern half of the fold. The fold evolved from open and up-right to overturned and tight, is cross-cut by multiple faults, and was subsequently dismembered by the Hurricane fault. The western half of the fold is obscured because of burial, along with the hanging wall of the Hurricane fault, beneath Neogene and younger …


Operational Water Forecast Ability Of The Hrrr-Isnobal Combination: An Evaluation To Adapt Into Production Environments, Joachim Meyer, John Horel, Patrick Kormos, Andrew Hedrick, Ernesto Trujillo, S. Mckenzie Skiles Jan 2023

Operational Water Forecast Ability Of The Hrrr-Isnobal Combination: An Evaluation To Adapt Into Production Environments, Joachim Meyer, John Horel, Patrick Kormos, Andrew Hedrick, Ernesto Trujillo, S. Mckenzie Skiles

Geosciences Faculty Publications and Presentations

Operational water-resource forecasters, such as the Colorado Basin River Forecast Center (CBRFC) in the Western United States, currently rely on historical records to calibrate the temperature-index models used for snowmelt runoff predictions. This data dependence is increasingly challenged, with global and regional climatological factors changing the seasonal snowpack dynamics in mountain watersheds. To evaluate and improve the CBRFC modeling options, this work ran the physically based snow energy balance iSnobal model, forced with outputs from the High-Resolution Rapid Refresh (HRRR) numerical weather prediction model across 4 years in a Colorado River Basin forecast region. Compared to in situ, remotely sensed, …


The Geology Of El Paso, William Cornell, Diane Doser, Richard Langford, Joshua Villalobos, Jason Ricketts Jan 2023

The Geology Of El Paso, William Cornell, Diane Doser, Richard Langford, Joshua Villalobos, Jason Ricketts

Books & Monographs

The Geology of El Paso describes the history of El Paso, Texas and its surrounding region from the Precambrian formation of the continent to the modern use of geologic resources. This book is written in an easy to digest format, with definitions or links for specific geologic terms and references for further reading. It reviews the formation and evolution of local landmark features such as the Franklin Mountains, Cerro Cristo Rey, and the Sierra de Juarez. Fossils and stratigraphic units of the El Paso area are described as well as important geologic features. The book puts the events that shaped …


Magnetic Anomaly Data Products Of The Central And Eastern United States, Dhananjay Ravat Jan 2023

Magnetic Anomaly Data Products Of The Central And Eastern United States, Dhananjay Ravat

Earth and Environmental Sciences Research Data

This data set contains Central and Eastern U.S. Magnetic Anomaly, DRTP, Tilt Derivative, and Analytic Signal Amplitude Products ultimately derived from Ravat, D., Finn, C., Hill, P., Kucks, R., Phillips, J., Blakely, R., Bouligand, C., Sabaka, T., Elshayat, A., Aref, A., and Elawadi, E., 2009, A preliminary, full spectrum, magnetic anomaly grid of the United States with improved long wavelengths for studying continental dynamics--A website for distribution of data: U.S. Geological Survey Open- File Report 2009–1258, 2 p.


Precise Zircon U-Pb Dating Of The Mesoproterozoic Gawler Large Igneous Province, South Australia, Elizabeth A. Jagodzinski, Anthony J. Reid, James L. Crowley, Claire E. Wade, Stacey Curtis Jan 2023

Precise Zircon U-Pb Dating Of The Mesoproterozoic Gawler Large Igneous Province, South Australia, Elizabeth A. Jagodzinski, Anthony J. Reid, James L. Crowley, Claire E. Wade, Stacey Curtis

Geosciences Faculty Publications and Presentations

The Mesoproterozoic Gawler Range Volcanics and Benagerie Volcanic Suite of the Gawler Craton and Curnamona Province, South Australia, together with associated intrusive magmatism, define an intracontinental, subaerial large igneous province (LIP) preserving an estimated 110 000 km3 of volcanic rock, which hosts one of the world's largest orebodies, the Fe oxide-Cu-Au-U deposit at Olympic Dam, and numerous other related Cu-Au deposits. New high-precision Chemical Abrasion Isotope Dilution Thermal Ionization Mass Spectrometry (CA-TIMS) U-Pb dates on volcanic zircons allow for regional correlations between stratigraphic units of the GRV and BVS, and an understanding of how magmatic styles, temperatures, composition and …


Drivers Of Spatiotemporal Patterns Of Surface Water Inputs In A Catchment At The Rain-Snow Transition Zone Of The Water-Limited Western United States, E. Trujillo, J. Mcnamara Jan 2023

Drivers Of Spatiotemporal Patterns Of Surface Water Inputs In A Catchment At The Rain-Snow Transition Zone Of The Water-Limited Western United States, E. Trujillo, J. Mcnamara

Geosciences Faculty Publications and Presentations

Spatial and temporal dynamics of rainfall and snowmelt (i.e., surface water inputs, SWI) control soil moisture, groundwater recharge, and streamflow at annual, seasonal, and event scales. In the rain-snow transition zone, comprising a large portion of the mountainous western United States, there is limited understanding of the sensitivity of spatiotemporal SWI dynamics across hydrologically variable water years (WYs). We modeled rainfall and snowpack dynamics in a small headwater catchment (1.8 km2) spanning the rain-snow transition in southwestern Idaho, USA, for two hydrologically distinct WYs (2011 and 2014). In wet WY 2011 and dry WY 2014, total precipitation drove …


Elastic Thermobarometry, Matthew J. Kohn, Mattia L. Mazzucchelli, Matteo Alvaro Jan 2023

Elastic Thermobarometry, Matthew J. Kohn, Mattia L. Mazzucchelli, Matteo Alvaro

Geosciences Faculty Publications and Presentations

Upon exhumation and cooling, contrasting compressibilities and thermal expansivities induce differential strains (volume mismatches) between a host crystal and its inclusions. These strains can be quantified in situ using Raman spectroscopy or X-ray diffraction. Knowing equations of state and elastic properties of minerals, elastic thermobarometry inverts measured strains to calculate the pressure-temperature conditions under which the stress state was uniform in the host and inclusion. These are commonly interpreted to represent the conditions of inclusion entrapment. Modeling and experiments quantify corrections for inclusion shape, proximity to surfaces, and (most importantly) crystal-axis anisotropy, and they permit accurate application of the more …


Pacific Northwest Streamflow Data Landscape: A Report From The 2022 Streamflow Data Roundtables, Kendra E. Kaiser Jan 2023

Pacific Northwest Streamflow Data Landscape: A Report From The 2022 Streamflow Data Roundtables, Kendra E. Kaiser

Geosciences Faculty Publications and Presentations

This project was funded by the U.S. Geological Survey Northwest Climate Adaptation Science Center to catalog the location, temporal extent and purpose of non-USGS streamflow datasets. As part of this project, roundtable meetings convened local, state and federal agencies, and nonprofits to explore the complexity of gathering and integrating the identified datasets and identify issues surrounding data-sharing across organizations.

This report synthesizes discussions from each of the state roundtable discussions convened in the spring of 2022, and highlights common challenges and needs across the region. Additional information from organizations not able to be present at the meetings were added after …


New Age Constraints On The Break-Up Of Rodinia And Amalgamation Of Southwestern Gondwana From The Choquequirao Formation In Southwestern Peru, Eben Blake Hodgin, Victor Carlotto, Francis A. Macdonald, Mark D. Schmitz, James L. Crowley Jan 2023

New Age Constraints On The Break-Up Of Rodinia And Amalgamation Of Southwestern Gondwana From The Choquequirao Formation In Southwestern Peru, Eben Blake Hodgin, Victor Carlotto, Francis A. Macdonald, Mark D. Schmitz, James L. Crowley

Geosciences Faculty Publications and Presentations

The Choquequirao Formation is a >3 km-thick amphibolite-grade succession that outcrops in the Central Andes of southern Peru. To constrain its age and tectonostratigraphic setting, detrital zircon and metamorphic zircon, titanite, and rutile U–Pb isotopic analyses were conducted. Mantle-derived c. 640 Ma detrital zircons constrain the maximum age of the lower part of the succession and 550–490 Ma metamorphic zircon domains constrain its minimum age. The absence of early Paleozoic detrital zircons suggests that deposition predated early Paleozoic orogenesis in southwestern Gondwana. The close similarity of detrital zircon age spectra to those from sediments deposited on the Arequipa basement suggests …


Insights Into Initial Continental Rifting Of Marginal Seas From Seismic Evidence For Slab Relics In The Mid-Mantle Of The Woodlark Rift, Southwestern Pacific, Youqiang Yu, Frederik Tilmann, Stephen S. Gao, Kelly H. Liu, Jiaji Xi Jan 2023

Insights Into Initial Continental Rifting Of Marginal Seas From Seismic Evidence For Slab Relics In The Mid-Mantle Of The Woodlark Rift, Southwestern Pacific, Youqiang Yu, Frederik Tilmann, Stephen S. Gao, Kelly H. Liu, Jiaji Xi

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The initiation and evolution of marginal seas, especially those developing under a convergent setting, is one of the more enigmatic aspects of plate tectonics. Here, we report the presence of slab relics in the mid-mantle of the Woodlark rift in the southwestern Pacific based on a new map of the topography of the mantle discontinuities from a receiver function analysis and evidence from body-wave tomography. the widespread mantle transition-zone thickening rules out active mantle upwelling, and the revealed slab relics in both the upper and middle mantle may hydrate the upper mantle, which can be expected to further weaken the …


Ongoing Fragmentation Of The Subducting Cocos Slab, Central America, Tu Xue, Diandian Peng, Kelly H. Liu, Jonathan Obrist-Farner, Marek Locmelis, Stephen S. Gao, Lijun Liu Jan 2023

Ongoing Fragmentation Of The Subducting Cocos Slab, Central America, Tu Xue, Diandian Peng, Kelly H. Liu, Jonathan Obrist-Farner, Marek Locmelis, Stephen S. Gao, Lijun Liu

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Fundamental to plate tectonics is the subduction of cold and mechanically strong oceanic plates. While the subducted plates are conventionally regarded to be impermeable to mantle flow and separate the mantle wedge and the sub slab region, isolated openings have been proposed. by combining new shear wave splitting measurements with results from geodynamic modeling and recent seismic tomography and geochemical observations, we show that the upper ~200 km of the Cocos slab in northern Central America is intensively fractured. the slab there is strong enough to produce typical arc volcanoes and Benioff Zone earthquakes but allows mantle flow to traverse …


Erratum: New Estimates Of The Magnitude Of The Sea-Level Jump During The 8.2 Ka Event, (Geology (2022), 50(1), (86–90), (10.1130/G49296.1)), Jonathan Obrist-Farner, Mark Brenner, Jeffery R. Stone, Marta Wojewódka-Przybył, Thorsten Bauersachs, Andreas Eckert, Marek Locmelis, Jason H. Curtis, Susan R.H. Zimmerman, Alex Correa-Metrio, Lorenz Schwark, Edward Duarte, Antje Schwalb, Etienne Niewerth, Paula Gabriela Echeverría-Galindo, Liseth Pérez Jan 2023

Erratum: New Estimates Of The Magnitude Of The Sea-Level Jump During The 8.2 Ka Event, (Geology (2022), 50(1), (86–90), (10.1130/G49296.1)), Jonathan Obrist-Farner, Mark Brenner, Jeffery R. Stone, Marta Wojewódka-Przybył, Thorsten Bauersachs, Andreas Eckert, Marek Locmelis, Jason H. Curtis, Susan R.H. Zimmerman, Alex Correa-Metrio, Lorenz Schwark, Edward Duarte, Antje Schwalb, Etienne Niewerth, Paula Gabriela Echeverría-Galindo, Liseth Pérez

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

No abstract provided.


Causes, Responses, And Implications Of Anthropogenic Versus Natural Flow Intermittence In River Networks, Kendra E. Kaiser Jan 2023

Causes, Responses, And Implications Of Anthropogenic Versus Natural Flow Intermittence In River Networks, Kendra E. Kaiser

Geosciences Faculty Publications and Presentations

Rivers that do not flow year-round are the predominant type of running waters on Earth. Despite a burgeoning literature on natural flow intermittence (NFI), knowledge about the hydrological causes and ecological effects of human-induced, anthropogenic flow intermittence (AFI) remains limited. NFI and AFI could generate contrasting hydrological and biological responses in rivers because of distinct underlying causes of drying and evolutionary adaptations of their biota. We first review the causes of AFI and show how different anthropogenic drivers alter the timing, frequency and duration of drying, compared with NFI. Second, we evaluate the possible differences in biodiversity responses, ecological functions, …


Carbon Capture, Utilization, And Storage, University Of North Dakota. Energy And Environmental Research Center Jan 2023

Carbon Capture, Utilization, And Storage, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet about carbon capture, utilization, and storage (CCUS) and the Energy & Environmental Research Center’s CCUS capabilities. Includes information on the Plains CO2 Reduction (PCOR) Partnership initiative, Brine Extraction and Storage Test (BEST), Carbon Storage Assurance Facility Enterprise (CarbonSAFE), Red Trail Energy Carbon Capture and Storage, a feed study at Coal Creek Station, Bell Creek and Cedar Creek anticline projects, and Partnership for CO2 Capture (PCO2C).


Closing The Modern Seismic Gap Along The Teton Fault Via Seismic Mapping Of Mass Transport Deposits In Jackson Lake, Wy, Callia Jacqueline Cortese Jan 2023

Closing The Modern Seismic Gap Along The Teton Fault Via Seismic Mapping Of Mass Transport Deposits In Jackson Lake, Wy, Callia Jacqueline Cortese

Theses and Dissertations--Earth and Environmental Sciences

Terrestrial paleoseismological records along the Teton fault have historically indicated two-to-three major post-Pinedale (~14 ka) earthquake events, leaving an unresolved 6-9 m offset along the modern scarp. Recent studies of Jenny Lake have augmented this record, but the triggering mechanism is still equivocal until new paleo-earthquake records are developed. The earthquake record of the Teton fault is complicated by quiescence from ~5 ka to present, demonstrating the need for additional paleoseismic investigations. Compressed, high-intensity radar pulse (CHIRP) reflection data from Jackson Lake indicates multiple potentially seismically-induced mass transport deposits (MTDs). At least six MTD Groups representing chronostratigraphic intervals were interpreted …


Discovery Of The Middle Mantle Transition Zone (Mmtz) And Its Geodynamic Significance, Yuping Wang Jan 2023

Discovery Of The Middle Mantle Transition Zone (Mmtz) And Its Geodynamic Significance, Yuping Wang

Theses and Dissertations--Earth and Environmental Sciences

Global mantle discontinuities and mantle transition zones are crucial to the earth’s evolution. By employing K-Means clustering, which belongs to cluster analysis in machine learning (ML), on shear velocity variation data, we generate heterogeneity percentage profiles for three different global tomographic models (Models S362WMANI+M, SEMUCB-WM1, and S40RTS). Key cluster percentage shifts, which are observed at around 400 km, 650 km, 1050 km, 1500 km, and 2700 km, suggest global mantle discontinuities at corresponding depths. All profiles also indicate a global discontinuity in the lower mantle between 2200 km and 2600 km. The middle mantle transition zone (MMTZ), bounded between 1050 …


Constraining Rock Type Controls On Geophysical Properties: Implications For Earthquake Hazard Assessment Near Ellensburg, Washington, Zachary Stevens Jan 2023

Constraining Rock Type Controls On Geophysical Properties: Implications For Earthquake Hazard Assessment Near Ellensburg, Washington, Zachary Stevens

All Master's Theses

High precision geophysical modeling can constrain the geometry of structures in the upper to middle crust beyond what is possible with surface data alone, which allows for a better understanding of seismic hazards. This modeling requires values of both the magnetic susceptibility and density relevant to rocks at depth; this study presents a combination of field and laboratory measurements of basement units to determine these properties. The basement rock of the Kittitas Valley is made up of a complex series of metamorphic and igneous bodies, so it was important to gather a representative suite of samples of the most volumetrically …


Paleoseismic Investigation Of Rupture On The Dead Coyote Fault In The Kittitas Valley, Washington, Garet Huddleston Jan 2023

Paleoseismic Investigation Of Rupture On The Dead Coyote Fault In The Kittitas Valley, Washington, Garet Huddleston

All Master's Theses

Recently discovered fault scarps along the Dead Coyote Fault (DCF) in the northern Kittitas Valley (KV) of central Washington suggests active faulting in the late Quaternary, but constraints on the timing and potential magnitude of earthquakes along the fault zone are limited. The KV lies at the northwestern edge of the Yakima Fold and Thrust Belt (YFTB), a low-strain region where individual structures are capable of producing M~7 earthquakes.

This investigation uses surficial geologic mapping and topographic analysis of the DCF scarps, ground penetrating radar transects, and paleoseismic trenching to determine the rupture history of the DCF. The trench was …


Communicating Hazard Location Through Text And Map In Earthquake Early Warnings: A Mixed Methods Study, Jeannette Sutton, Michele M. Wood, Nicholas A. Waugh, Savanah Crouch Jan 2023

Communicating Hazard Location Through Text And Map In Earthquake Early Warnings: A Mixed Methods Study, Jeannette Sutton, Michele M. Wood, Nicholas A. Waugh, Savanah Crouch

Emergency Preparedness, Homeland Security, and Cybersecurity Faculty Scholarship

The purpose of this research was to examine the effect of presenting hazard location in different formats on key warning message outcomes—understanding, personalizing, believing, deciding, and milling. We conducted two studies using experiment and focus group methods. In the experiment, we compared a standard ShakeAlert earthquake early warning message, which merely implied location, to three enhanced messages that communicated information about the earthquake epicenter via text, map, or a combined text-and-map format. Focus groups explored reactions to warning messages accompanied by different types of maps. Overall, the standard ShakeAlert message was associated with worse message outcomes compared to messages that …


Comprehensive Analysis Of Seismic Signals From Pacaya Volcano Using Deep Learning Event Detection, Jessica L. Devlieg Jan 2023

Comprehensive Analysis Of Seismic Signals From Pacaya Volcano Using Deep Learning Event Detection, Jessica L. Devlieg

Dissertations, Master's Theses and Master's Reports

Pacaya volcano located 30 km SW of Guatemala City, Guatemala, has been erupting intermittently since 1961. Monitoring of seismicity is crucial to understanding current activity levels within Pacaya. Traditional methods of picking these small earthquakes in this noisy environment are imprecise. Pacaya produces many small events that can easily blend in with the background noise. A possible solution for this problem is a machine learning program to pick first arrivals for these earthquakes. We tested a deep learning algorithm (Mousavi et al., 2020) for fast and reliable seismic signal detection within a volcanic system. Data from multiple deployments were used, …


Evaluating The Sensitivity Of Crustal Deformation To Bedrock Hydrology In A Mountain Watershed, Brett J. Oliver Jan 2023

Evaluating The Sensitivity Of Crustal Deformation To Bedrock Hydrology In A Mountain Watershed, Brett J. Oliver

Graduate Student Theses, Dissertations, & Professional Papers

We evaluate the sensitivity of Earth's elastic deformation to groundwater hydraulic diffusivity using coupled groundwater and elastic deformation models. Seasonal changes in terrestrial water storage cause deformation to the Earth’s crust and deeper interior that is within the observational capacity of GPS instruments. We couple finite difference groundwater simulations with geodetic forward models of crustal displacement to investigate the ability of geodetic deformation to constrain bedrock hydrologic properties. We use MODFLOW-2005 to simulate seasonal changes in groundwater flow and storage, and then use the LoadDef elastic deformation model to forward model surface displacement caused by the change in terrestrial water …