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Full-Text Articles in Volcanology

Seismological Investigations Of Magmatic Systems Using Dense Nodal Arrays, Wenkai Song Dec 2025

Seismological Investigations Of Magmatic Systems Using Dense Nodal Arrays, Wenkai Song

Earth and Planetary Sciences ETDs

Understanding the internal architecture of magmatic systems is crucial for volcanology, yet conventional geophysical techniques often lack the resolution to image their fine-scale structures. This dissertation leverages unique datasets from dense nodal arrays to investigate the upper crustal magmatic systems beneath Yellowstone Caldera, Valles Caldera, and Mount St. Helens. At Yellowstone, I processed vibroseis data to delineate the top of the modern magma reservoir and evaluate the thermal connection between the magmatic and the overlying hydrothermal systems. At Valles, 3D radial seismic anisotropy imaging reveals strong positive radial anisotropy within the reservoir, indicating an organized structure of horizontally sill-like melt …


Seeking Structure In Complex Systems: From Feature Analysis To Space-Time Causal Discovery With Earth Science Applications, Jeffrey J. Nichol Jul 2025

Seeking Structure In Complex Systems: From Feature Analysis To Space-Time Causal Discovery With Earth Science Applications, Jeffrey J. Nichol

Computer Science ETDs

Complex systems are difficult to study because of their many interacting parts, emergent phenomena, and feedback loops. These systems underpin all life on Earth. We need improved tools for seeking an understanding of them. This body of research presents my investigations into data-driven methods for understanding complex systems, including my invention of a novel causal discovery meta-algorithm for space-time gridded data. I demonstrated machine learning feature importance and causal discovery capabilities for comparing simulated and observed climate data. I developed a new benchmark for modeling space-time dynamics of locally driven phenomena and examined a prominent causal discovery algorithm. Finding that …


Aerial Robotic Studies Of Volcanic Co2 Emissions, John Ericksen May 2025

Aerial Robotic Studies Of Volcanic Co2 Emissions, John Ericksen

Computer Science ETDs

Volcanic systems are inherently complex, involving dynamic interactions among magma flow, gas emissions, and atmospheric dispersion. This dissertation focuses on developing and analyzing autonomous UAS algorithms for efficiently surveying volcanic CO2 plumes, introducing several novel methods: the LoCUS algorithm, a swarm coordination and self-healing algorithm that supports gradient-based plume tracking, a transect-based technique that employs a 2D Gaussian fit to calculate CO2 plume flux, and the Sketch algorithm for rapid plume boundary tracing. By treating multiple UAS as a single scientific instrument, these methods leverage swarm algorithms to use in-situ data in ways impossible with individual drones. Validated through simulations …


Remote Sensing Techniques To Determine Volcanic Gas Components And Fluxes: Application For Lascar, Chile And Fagradalsfjall, Iceland Volcanos., Felipe S. Rojas Vilches Apr 2024

Remote Sensing Techniques To Determine Volcanic Gas Components And Fluxes: Application For Lascar, Chile And Fagradalsfjall, Iceland Volcanos., Felipe S. Rojas Vilches

Earth and Planetary Sciences ETDs

Volcanic plumes allow us to understand different aspects of a volcanic system including magma movements, dynamics, mass transfer, overall gas emissions to the atmosphere, and many processes that impact human life. However, the H₂O gas is poorly constrained due to the intrinsic difficulties of this gas, with high background values and easily dispersed/integrated into the background. In this work we study the gas emissions from Lascar volcano, and Fagradalsfjall volcano, in Chile and Iceland, respectively, using a combination of different ground-based remote sensing techniques and in situ plume measurements, we measure H₂O, SO₂, CO₂, CO, and H₂S from longer and …


Quantifying Co2 And Heat Fluxes At Roosevelt Hot Springs, Hydrothermal Area, Samantha R. Wolf Nov 2023

Quantifying Co2 And Heat Fluxes At Roosevelt Hot Springs, Hydrothermal Area, Samantha R. Wolf

Earth and Planetary Sciences ETDs

Roosevelt Hot Springs is an actively producing hydrothermal system that has been extensively studied by field, geophysical and geochemical techniques since the 1970’s. Roosevelt Hot Springs sits at the western base of the Mineral Mountains in Utah, an area that has formed because of many volcanic, thermal and structural events since the late Oligocene. The work in this manuscript is the first of its kind to incorporate measurements of spring-based CO2 fluxes with diffuse measurements to quantify the total CO2 Flux in tons per day of a Basin and Range and Colorado Plateau Transition Zone-hosted hydrothermal system. Using …


Seismic Shadow Zone Investigation In The Upper Magma Reservoir Of The Yellowstone Caldera, Sarah Nolt-Caraway Aug 2023

Seismic Shadow Zone Investigation In The Upper Magma Reservoir Of The Yellowstone Caldera, Sarah Nolt-Caraway

Earth and Planetary Sciences ETDs

This study investigates whether the Yellowstone Caldera has enough melt to mute S-waves, creating a seismic shadow zone. Using a dense nodal deployment of ~650 stations, 7-9 earthquakes during the nodal deployment, and 21 broadband stations with 3,000-4,000 events per station; amplitude and noise maps, seismograms, and automatic phase picks probabilities from a deep learning model were analyzed to assess the potential role of melt, crustal attenuation, and noise in affecting body waves, particularly S-phases. The results are inconclusive, with unclear evidence whether observed amplitude decay is normal signal decay due to distance, noise-related, melt, or from scattering and intrinsic …


Deformation At Uturuncu Volcano, Bolivia: Modeling The Effect Of Volatile Movement In The Hydrothermal System, Karissa Rosenberger May 2023

Deformation At Uturuncu Volcano, Bolivia: Modeling The Effect Of Volatile Movement In The Hydrothermal System, Karissa Rosenberger

Earth and Planetary Sciences ETDs

Deformation at volcanos is often a precursor to an eruption, but sometimes volcanos experience uplift without actually erupting. Determining the mechanisms behind this deformation and whether it will lead to an eruption is an important part of understanding volcanic systems. Uturuncu volcano in Bolivia has been experiencing deformation for decades, but the last time it erupted was 250,000 years ago. The reason behind this deformation is unknown, but one possible cause is volatiles moving into the hydrothermal system and getting trapped, causing the volume to increase and the surface to uplift. To test this hypothesis, the current volume change of …


Petrology And Geochemistry Of Evolved Achondrites: Planetesimal Mantles And Crusts, Zoltan Vaci Jul 2021

Petrology And Geochemistry Of Evolved Achondrites: Planetesimal Mantles And Crusts, Zoltan Vaci

Earth and Planetary Sciences ETDs

Melting and differentiation are fundamental to early solar system evolution on planetary bodies that accreted enough material to heat up radioactively or through impacts and breach their solidi. Partially and fully melted material is present in the meteorite record in the form of primitive achondrites and achondrites, which are fragments of planetesimals that underwent heating events in the first few million years of solar system history. Although the vast majority of this material is mafic or ultramafic, new evolved samples, recovered in the last few decades, are pushing the petrologic and geochemical boundaries of planetesimal melting, differentiation, and crust formation. …


Diffuse Flux And Carbon Isotope Composition Of Carbon Dioxide Emitted From Valles Caldera, Yellowstone Caldera, And Southwestern Utah Geothermal Sites, Kristen Rahilly May 2020

Diffuse Flux And Carbon Isotope Composition Of Carbon Dioxide Emitted From Valles Caldera, Yellowstone Caldera, And Southwestern Utah Geothermal Sites, Kristen Rahilly

Earth and Planetary Sciences ETDs

Carbon dioxide (CO2) has the lowest solubility in silicate melt and is one of the most abundant and earliest degassed species present in volcanic and geothermal systems. A significant quantity of CO2 is passively degassed through soils in volcanic and geothermal systems, called diffuse degassing. In Chapter 1, I measure the diffuse CO2 flux over the site of a prospective enhanced geothermal system in southwestern Utah. I conclude that the CO2 emitted from soils in the enhanced geothermal site is biogenically-sourced. In Chapter 3, I examine the diffuse CO2 flux from Roosevelt Hot Springs …


Magmatic Hydrothermal Alteration And Secondary Post-Shock Features In Martian Olivine-Phyric Basalt Northwest Africa 10416; Petrology And Geochemistry Of Primitive Achondrite Northwest Africa 11042, Zoltan Vaci May 2017

Magmatic Hydrothermal Alteration And Secondary Post-Shock Features In Martian Olivine-Phyric Basalt Northwest Africa 10416; Petrology And Geochemistry Of Primitive Achondrite Northwest Africa 11042, Zoltan Vaci

Earth and Planetary Sciences ETDs

The Martian olivine-phyric basalt Northwest Africa (NWA) 10416 contains large olivine xenocrysts whose cores have been stained brown by hydrothermal alteration and whose rims are composed of pristine olivine overgrowths. Microanalysis of these olivine cores reveals various degrees of amorphization, some of which have been overprinted by terrestrial weathering, evident as part of a weathering rind along the exposed surface of the meteorite. Studies of a completely unweathered terrestrial analogue basalt from southern Colorado reveal similar features and indicate that both basalts were altered in a supersolidus magma chamber setting. The alteration features in NWA 10416 thus imply the presence …


Classifying Microseismicty At Mount St. Helens Using A Large-N Array, Margaret E. Glasgow Apr 2017

Classifying Microseismicty At Mount St. Helens Using A Large-N Array, Margaret E. Glasgow

Earth and Planetary Sciences ETDs

A dense array of ~1,000 continuously recording, short-period geophones was deployed in the summer of 2014 within ~15 km of Mount St. Helens. Two earthquake catalogs created using reverse time imaging and template detection techniques, increase the detection rate and completeness of the earthquake catalog when compared to the permanent network, Pacific Northwest Seismic Network, catalog. An investigation into event type for ~200 of the earthquake detections leads to the discrimination of two major classification groups, volcano-tectonic and long period. Previous to this study, long period earthquakes had not been identified in the upper crust during a volcanically inactive period …


Birth And Evolution Of The Rio Grande Fluvial System In The Last 8 Ma:Progressive Downward Integration And Interplay Between Tectonics, Volcanism, Climate, And River Evolution, Marisa N. Repasch Sep 2016

Birth And Evolution Of The Rio Grande Fluvial System In The Last 8 Ma:Progressive Downward Integration And Interplay Between Tectonics, Volcanism, Climate, And River Evolution, Marisa N. Repasch

Earth and Planetary Sciences ETDs

The Rio Grande-Rio Chama (RG-RC) fluvial system has evolved dramatically over the last 8 Ma, undergoing channel migrations, drainage capture and integration events, volcanic damming, and carving and refilling of paleocanyons. Volcanism concurrent with the development of the river system provides a unique opportunity to apply multiple geochronometers to the study of its incision and drainage evolution. This paper reports 19 new 40Ar/39Ar basalt ages and 19 detrital mineral samples (zircon and sanidine) collected from RG-RC alluvium overlain by dated basalt flows in the context of a compilation of published 40Ar/39Ar basalt ages. The …