Volcanology Commons^™

Debris Fan Produced By Failure Of Canyon-Blocking Pyroclastic Flows, Michael L. Cummings

Geology Faculty Publications and Presentations

Ash-rich pyroclastic flows from the cataclysmic eruption of Mount Mazama (~7700 yr. B. P.), Cascade volcanic arc, Oregon, entered and blocked the narrow, bedrock-lined canyon of the Williamson River approximately 35 to 44 km from the source volcano. The blockage impounded a body of water which then released producing four stratigraphic units in the downstream debris fan. The four stratigraphic units are a boulder core comprised of locally sourced bedrock boulders and three sand-rich units including a fine-grained sand unit, a sandy pumice gravel (±basalt/hydrovolcanic tuff) unit, and a pumice pebble-bearing, crystal-rich sand unit. Hand-drilled auger holes up to ~1.6 …

Mantle Sources And Geochemical Evolution Of The Picture Gorge Basalt, Columbia River Basalt Group, Emily B. Cahoon, Martin J. Streck, Richard W. Carlson, Ilya N. Bindeman

Geology Faculty Publications and Presentations

The Columbia River Basalt Group (CRBG) is the youngest continental flood basalt province, proposed to be sourced from the deep-seated plume that currently resides underneath Yellowstone National Park. If so, the earliest erupted basalts from this province, such as those in the Picture Gorge Basalt (PGB), aid in understanding and modeling plume impingement and the subsequent evolution of basaltic volcanism. Using geochemical and isotopic data, this study explores potential mantle sources and magma evolution of the PGB. Long known geochemical signatures of the PGB include overall large ion lithophile element (LILE) enrichment and relative depletion of high field strength elements …

Deformation Mapping And Modeling Of The Aleutian Volcanoes With Insar And Numerical Models, Jiahui Wang

Earth Sciences Theses and Dissertations

Surface deformation mapping is an essential component for comprehensive monitoring of volcanic activities, serving as a vital tool for discerning crucial insights into magma dynamics, storage, and migration for accurate hazard forecasting, assessment, and mitigation. However, monitoring of the volcanic deformation across the Aleutian volcanic arc is usually limited by the lack of terrestrial sensors deployed due to their remote locations and hostile environmental conditions, necessitating alternative methodologies for data acquisition and analysis.

My PhD study aims at precisely mapping the crustal deformation for the Aleutian volcanoes and tracking the evolution of the magmatic system with Interferometric Synthetic Aperture Radar …

Textural Investigation Into Rapid Welding Transitions In The Tuff Of Leslie Gulch Along Succor Creek At The Mahogany Mountain-Three Fingers Rhyolite Field, Southeastern Oregon, Alicia J. Martinez-Garling, Martin J. Streck

Student Research Symposium

The Mahogany Mountain-Three Fingers Rhyolite Field (MM-TFrf) in southeastern Oregon, associated with mid-Miocene rhyolite activity and Columbia River flood basalts, has been the subject of geological scrutiny. Previous studies proposed separate origins for the tuff of Leslie Gulch (LGT) and Spring Creek, but Benson and Mahood (2006) suggested a single ignimbrite event at 15.8 Ma, prompting a reassessment of MM-TFrf's history. This research focuses on LGT, investigating textural disparities between welded and non-welded tuff formations. Petrographic examinations delve into the transformation stages of pyroclastic tuff deposition, revealing the dynamic influences of volcanological and magmatic processes on welded and non-welded tuff …

Pre-Plinian Perplexity: Identifying And Constraining An Anomalous Pdc During The Initial Stages Of The May 18, 1980 Mt. St. Helens Eruption, Justin Crevier

Geosciences Undergraduate Theses

The Mount St. Helens (MSH) 18 May 1980 eruption was a formative event for a generation of volcanologists. With so much data available from detailed studies of the Blast and Plinian phases, MSH could aptly be called one of volcanology's greatest teachers—and the volcano may yet have more to teach us. The transition period, which occurred between the end of the Blast phase (0830) and the beginning of the Plinian phase (0920) on the morning of May 18, 1980, has not yet benefited from the same degree of comprehensive review as either of those phases. The conditions which caused the …

Volcanic Ash In Lincoln County, Kansas, Logan Erichsen

SACAD: Scholarly Activities

This report outlines the analysis of Pearlette volcanic ash in Lincoln County Kansas. Both field and lab methods were used to compile this report. Fort Hays State University alumni Dr. Ron Whitmer allowed use of his property on which the ash is found. Auguring was utilized as the main form of field work which allowed mapping of the subsurface ash layer. The ash was analyzed by UMKC using their scanning electron microscope (SEM). At Fort Hays, the SEM reports were compared to thin sections of the ash using plane and cross polarized light in petrographic microscopes. The ash is comprised …

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 …

The Influence Of Volcano Edifice Resonance On The Seismic Triggering Of Thermal Activity At Active Volcanoes, Morgana M. Wilke

Dissertations, Master's Theses and Master's Reports

There is an established correlation between large earthquakes and volcanic unrest, however the mechanisms between this connection are not well understood. Relatively small changes in stress within a volcanic system could be enough to initiate a response. One aspect that could serve to amplify small dynamic stress changes is volcanic edifice resonance triggered by surface waves at resonant frequency. In this paper, we investigate the relationship between thermal activity of volcanoes and various minimum thresholds of Love wave amplitudes at resonance caused by teleseismic earthquakes above a 7.0 M. Satellite-derived thermal data from 25 volcanoes are modeled in relation to …

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 …

A Bayesian Inversion For Emissions And Export Productivity Across The End-Cretaceous Boundary, Alexander A. Cox

Dartmouth College Master’s Theses

The end-Cretaceous mass extinction was marked by both the Chicxulub impact and the ongoing emplacement of the Deccan Traps flood basalt province. Both of these events perturbed the environment by the emission of climate-active volatiles, primarily CO2 and SO2. To understand the mechanism of extinction, we must disentangle the timing, duration, and intensity of volcanic and meteoritic environmental forcings. In this thesis, we used a parallel Markov chain Monte Carlo approach to invert for the aforementioned volatile emissions, export productivity, and remineralization from 67 to 65 million years ago using the LOSCAR (Long-term Ocean-atmosphere-Sediment CArbon cycle Reservoir) model. The parallel …

Ice-Marginal Volcanic Sequence In Iceland Found On A Nondescript Gradual Hillslope: An Unexpected Record Of Ice Thickness Late In Deglaciation, Audrey R. Putnam, Kristen L. Siebach, Candice C. Bedford, Sarah L. Simpson, Michael T. Thorpe, Joseph J. Tamborski

OES Faculty Publications

Volcanism increases when glaciers melt because isostatic rebound during deglaciation decreases the pressure on the mantle, which enhances decompression melting. Anthropogenic climate change is now causing ice sheets and valley glaciers to melt around the world and this deglaciation could stimulate volcanic activity and associated hazards in Iceland, Antarctica, Alaska, and Patagonia. However, current model predictions for volcanic activity associated with anthropogenic deglaciation in Iceland are poorly constrained, in part due to uncertainties in past volcanic output over time compared to ice sheet arrangements. Further work specifically characterizing glaciovolcanic and ice-marginal volcanoes in Iceland is needed to reconstruct volcanic output …

Eruption Initiation Mechanisms And Timescales At A Very-High-Threat Washington Volcano: Clues From Crystal Cargo In Lavas From Mount Baker (Koma Kulshan), Emily Yoder

All Master's Theses

Understanding the timescales of pre-eruptive processes is key for improving forecast models of future eruptions. Mount Baker (Koma Kulshan), WA, is part of the northern Cascade volcanic arc and classified as a very high threat volcano. However, we lack an understanding of the duration of time between the final magmatic process before eruption (potentially the process that initiated the eruption) and the eruption itself. This study focuses on (1) estimating eruption initiation timescales via diffusion chronometry and (2) determining eruption initiation mechanisms for three andesitic lava flows from Mount Baker: Dobbs Creek (~119 ka), Dobbs Cleaver (~105 ka), and Swift …

Timescales Of Magma Storage And The Pre-Eruptive History For The Most Recent Lava Flow At Mount Baker (Koma Kulshan), Wa, Desiree Cunningham

All Master's Theses

Mount Baker, ranked as a very-high threat volcano in the United States, is in a well-populated area in northern WA, putting many at risk in the event of a future eruption. Previous work on Mount Baker focused on understanding the magmatic architecture beneath the volcano and has identified multiple magmatic components that contributed to different eruptions throughout its history. The youngest lava flow in the Mount Baker Volcanic Field is the 9.8 ka Sulphur Creek lava flow. The last study conducted on this flow by Garvey (2022) determined the most recent magma mush configuration that was tapped for this eruption. …

A Petrographic And Geochemical Study Of The Rangataua Lava Flows, Mount Ruapehu, Aotearoa New Zealand, Lucy Smith

Scripps Senior Theses

Mount Ruapehu is a large stratovolcano on the North Island of Aotearoa New Zealand. The Rangataua lava flow is situated on the southern flanks of Ruapehu, and extends for 15-16 km. The flow is of andesite composition and comprised of three units: proximal, medial and distal. Mount Ruapehu is both scientifically and culturally significant.

Geochemical analyses of 13 whole rock samples, Electron Microprobe analyses of three polished thin sections, and geothermobarometry calculations were conducted to obtain data on pre-eruptive intensive parameters. Petrographic observations were used to investigate disequilibrium textures and shed light on magma chamber processes.

Results of this study …

Petrologic And Geochemical Constraints On The Pre-Eruptive Storage Conditions Of Magmas Erupted During The ~12.5 Ka Flare Up Of Medicine Lake Volcano, Ca, Regina M. Khoury

Cal Poly Humboldt theses and projects

The Medicine Lake Volcano (MLV) system in the California Cascades is composed of a large shield volcano with numerous basaltic to rhyolitic vents on and around the flanks, many of which are aligned with N-S trending normal faults. A significant portion of the post-glacial volcanic activity at MLV is comprised of the ~12.5 ka “flare up” eruptions of basalt and basaltic andesite magmas from seven discrete flank vents. Prior work documented surface areas (0.02-198 km²), volumes (0.0001-4.35 km³), and eruption styles (Hawaiian to Strombolian; Donnelly-Nolan, 2010) of the ~12.5 ka deposits. This study uses new geologic …

Million-Year Melt-Presence In Mogollon-Datil Volcanic Field Rhyolites: Constraining The Histories Of The Bursum Caldera Resurgent Domes, Ethan Wagner

Graduate Theses/Dissertations

The Mogollon-Datil volcanic field which is located in southwestern New Mexico, is the result of punctuated volcanism and the transition between arc and rift magmatism. The resurgent domes within the 28 Ma Bursum caldera records the transition from rhyolitic to basaltic andesite volcanism that occurred between 27-26 Ma. Using a combination of new zircon U-Pb ages using chemical abrasion isotope dilution thermal ionization mass spectrometry (CA-ID-TIMS) with zircon U-Pb geochronology and trace element contents by laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) and whole rock and mineral trace element contents and isotope geochemistry this study investigates the temporal and …

Ice-Marginal Lava Delta In Iceland Found On A Nondescript Shallow Slope: An Unexpected Record Of Ice Thickness Late In Deglacian, Audrey Putnam, Kirsten Siebach, Candice Bedford, Sarah Simpson, Elizabeth Rampe, Joseph Tamborski, Michael Thorpe

OES Faculty Publications

Volcanism increases when glaciers melt because isostatic rebound during deglaciation decreases the pressure on the mantle, which enhances decompression melting. Anthropogenic climate change is now causing ice sheets and valley glaciers to melt around the world and this deglaciation could stimulate volcanic activity and associated hazards in Iceland, Antarctica, Alaska, and Patagonia. However, current model predictions for volcanic activity associated with anthropogenic deglaciation in Iceland are poorly constrained, in part due to uncertainties in past volcanic output over time compared to ice sheet arrangements. Further work specifically characterizing glaciovolcanic and ice-marginal volcanoes in Iceland is needed to reconstruct volcanic output …

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 …

Volcanic Diffuse Volatile Emissions Tracked By Plant Responses Detectable From Space, Robert R. Bogue, Peter M. J. Douglas, Joshua B. Fisher, John Stix

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Volcanic volatile emissions provide information about volcanic unrest but are difficult to detect with satellites. Volcanic degassing affects plants by elevating local CO2 and H2O concentrations, which may increase photosynthesis. Satellites can detect plant health, or a reaction to photosynthesis, through a Normalized Difference Vegetation Index (NDVI). This can act as a potential proxy for detecting changes in volcanic volatile emissions from space. We tested this method by analyzing 185 Landsat 5 and 8 images of the Tern Lake thermal area (TLTA) in northeast Yellowstone caldera from 1984 to 2022. We compared the NDVI values of the thermal area with …

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 …