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Articles 121 - 150 of 308

Full-Text Articles in Volcanology

Petrology And Geochemistry Of The Bearwallow Mountain Andesite, Mogollon-Datil Volcanic Field, New Mexico, Conor Lee O'Dowd May 2019

Petrology And Geochemistry Of The Bearwallow Mountain Andesite, Mogollon-Datil Volcanic Field, New Mexico, Conor Lee O'Dowd

Graduate Theses/Dissertations

The Mogollon-Datil volcanic field (MDVF), located in southern New Mexico, is the result of episodic volcanism and the transition between arc and rift magmatism. The MDVF has been the focus of several mapping, stratigraphic, petrologic, geochronological, and geochemical studies to understand the complete volcanic and tectonic history. However, the majority of previous studies lack geochemical analyses on intermediate composition volcanic rocks, giving more attention to the large-volume ignimbrites and rhyolite flows as well as the minor basalt flows that occurred between 36 and 20 Ma. I present new whole-rock major- and trace-element analyses and petrographic textures on one of the …


Petrogenesis Of Off-Axis Lavas Erupted Along The 8˚20’ N Seamount Chain, East Pacific Rise, Molly Kassandra Anderson May 2019

Petrogenesis Of Off-Axis Lavas Erupted Along The 8˚20’ N Seamount Chain, East Pacific Rise, Molly Kassandra Anderson

Boise State University Theses and Dissertations

Lavas erupted at off-axis seamounts provide a window into mantle heterogeneity and melting systematics that are not easily observed on-axis at fast spreading mid-ocean ridges (MORs). This is because axial melts are efficiently mixed and homogenized within shallow axial magma chambers prior to eruption. To understand the deeper magmatic processes contributing to oceanic crustal formation, we examine the compositions of lavas erupted along a chain of off-axis seamounts, adjacent to the East Pacific Rise (EPR). Essential questions include: (1) What is the range of compositional variability erupted off-axis and how does that compare to lavas erupted on-axis? (2) Is there …


A Systematic Assessment Of Socio-Economic Impacts Of Prolonged Episodic Volcano Crises, Justin Peers May 2019

A Systematic Assessment Of Socio-Economic Impacts Of Prolonged Episodic Volcano Crises, Justin Peers

Electronic Theses and Dissertations

Uncertainty surrounding volcanic activity can lead to socio-economic crises with or without an eruption as demonstrated by the post-1978 response to unrest of Long Valley Caldera (LVC), CA. Extensive research in physical sciences provides a foundation on which to assess direct impacts of hazards, but fewer resources have been dedicated towards understanding human responses to volcanic risk. To evaluate natural hazard risk issues at LVC, a multi-hazard, mail-based, household survey was conducted to compare perceptions of volcanic, seismic, and wildfire hazards. Impacts of volcanic activity on housing prices and businesses were examined at the county-level for three volcanoes with a …


Tropospheric And Ionospheric Anomalies Induced By Volcanic And Saharan Dust Events As Part Of Geosphere Interaction Phenomena, Valerio Tramutoli, Francesco Marchese, Alfredo Falconieri, Carolina Filizzola, Nicola Genzano, Katsumi Hattori, Mariano Lisi, Jann-Yenq Liu, Dimitar Ouzounov, Michel Parrot, Nicola Pergola, Sergey Pulinets Apr 2019

Tropospheric And Ionospheric Anomalies Induced By Volcanic And Saharan Dust Events As Part Of Geosphere Interaction Phenomena, Valerio Tramutoli, Francesco Marchese, Alfredo Falconieri, Carolina Filizzola, Nicola Genzano, Katsumi Hattori, Mariano Lisi, Jann-Yenq Liu, Dimitar Ouzounov, Michel Parrot, Nicola Pergola, Sergey Pulinets

Mathematics, Physics, and Computer Science Faculty Articles and Research

In this work, we assessed the possible relation of ionospheric perturbations observed by Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions (DEMETER), Global Positioning System total electron content (GPS TEC), National Oceanic and Atmospheric Administration (NOAA)-derived outgoing longwave-Earth radiation (OLR), and atmospheric chemical potential (ACP) measurements, with volcanic and Saharan dust events identified by ground and satellite-based medium infrared/thermal infrared (MIR/TIR) observations. The results indicated that the Mt. Etna (Italy) volcanic activity of 2006 was probably responsible for the ionospheric perturbations revealed by DEMETER on 4 November and 6 December and by GPS TEC observations on 4 November and 12 …


There She Blows: Public Perceptions Of Mt. Merapi And Mt. Agung, Trey Atticus Spadone Apr 2019

There She Blows: Public Perceptions Of Mt. Merapi And Mt. Agung, Trey Atticus Spadone

Independent Study Project (ISP) Collection

Since Indonesia sits on the Pacific Ring of Fire, the archipelago is repeatedly affected by tsunamis, landslides, earthquakes, and volcanic eruptions. Indonesia has the most active volcanoes of any country in the world due to subduction zones between the Eurasian and Indo-Australian plates. The last major eruptions were in 2017 (Mt. Agung in Bali) and 2010 (Mt. Merapi in Central Java) which both required thousands of people to be evacuated from their homes. Since volcanoes have such a geological presence in the country, I was interested in investigating how aware the public is of volcanoes and their associated risks. Where …


Engaging The Greater Lafayette Community In A Journey Through The Earth Sciences: Purdue’S Eaps Earth Science Passport Day Event, Dara Laczniak, Bradley Garczynski Mar 2019

Engaging The Greater Lafayette Community In A Journey Through The Earth Sciences: Purdue’S Eaps Earth Science Passport Day Event, Dara Laczniak, Bradley Garczynski

Engagement & Service-Learning Summit

No abstract provided.


Trace Elements Of Volcanic Soils And Coffee – Kona, Kathryn Mollison, Nathaniel Bos, C. Renee Sparks Jan 2019

Trace Elements Of Volcanic Soils And Coffee – Kona, Kathryn Mollison, Nathaniel Bos, C. Renee Sparks

Summer Research

Much of the world's coffee is grown on soils that have developed from the chemical and physical weathering of basalt, a volcanic rock with relatively high iron content. Volcanic rocks vary in composition depending on the relative amounts of major elements that produce minerals such as plagioclase, pyroxene and olivine. The breakdown of these minerals is dependent on climate and slope as well as the initial composition. Chemical weathering associated with climate, eventually leads to the development of clay minerals, oxides, and hydroxides that are key components of the soil chemistry. The soil transfers elements to the coffee plant through …


Globally Detected Volcanic Lightning And Umbrella Dynamics During The 2014 Eruption Of Kelud, Indonesia, Kirstin A. Hargie, Alexa R. Van Eaton, L. G. Mastin, Robert H. Holzworth, John W. Ewert, Michael Pavolonis Jan 2019

Globally Detected Volcanic Lightning And Umbrella Dynamics During The 2014 Eruption Of Kelud, Indonesia, Kirstin A. Hargie, Alexa R. Van Eaton, L. G. Mastin, Robert H. Holzworth, John W. Ewert, Michael Pavolonis

Geology Faculty Publications and Presentations

Volcanic lightning shows considerable promise as a monitoring and research tool to characterize explosive eruptions. Its key strengths are rapid and remote detection, because the radio signals produced by lightning can propagate thousands of km at the speed of light. Despite these tantalizing properties, the scientific work on volcanic lightning has only recently started gaining momentum. Much more is needed to understand what lightning reveals about the evolution of an eruption in near-real time. Here we examine the timing and energy release of lightning generated by the eruption of Kelud volcano in Indonesia on 13 February 2014, as detected by …


Volcanic Glass As A Proxy For Cenozoic Elevation And Climate In The Cascade Mountains, Oregon, Usa, John Bershaw, Elizabeth J. Cassell, Tessa Boe Carlson, Ashley R. Streig, Martin J. Streck Jan 2019

Volcanic Glass As A Proxy For Cenozoic Elevation And Climate In The Cascade Mountains, Oregon, Usa, John Bershaw, Elizabeth J. Cassell, Tessa Boe Carlson, Ashley R. Streig, Martin J. Streck

Geology Faculty Publications and Presentations

After deposition, volcanic glass hydrates with ambient water, recording the average hydrogen isotope ratio (δD or δ2H) of local meteoric water during the hydration period. Previous researchers have used ancient glass δD values to reconstruct paleotopography and paleoclimate, while others have questioned the long-term reliability of the proxy as a recorder of ancient meteoric water. In this study, we sampled volcanic glasses ranging in age ~33 Ma to(east) side of the Oregon Cascade Mountains. Our results strongly suggest that volcanic glass acquires and preserves δD values that are proportional to the stable isotopic composition of environmental water at the time …


Testing The Use Of Vegetation Indices As Indicators Of Pre-Eruptive Volcanic Unrest At Kilauea Volcano, Hawaii, Quelyn Bekkering Jan 2019

Testing The Use Of Vegetation Indices As Indicators Of Pre-Eruptive Volcanic Unrest At Kilauea Volcano, Hawaii, Quelyn Bekkering

Dissertations, Master's Theses and Master's Reports

Satellite remote sensing has become an integral part of pre-eruptive and long-term volcano monitoring due to its low cost, spatial and temporal coverage, and time-series analysis capabilities. Pre-eruptive unrest at volcanoes can include increased fluxes of heat and volcanic gases, which can be manifested either directly (e.g., the appearance of thermal anomalies or fumaroles) or indirectly (e.g., through impacts on vegetation health and extent). We are evaluating the use of novel, high spatial and temporal resolution data from the Planet Labs cubesat constellation to monitor changes in vegetation related to volcanic unrest. We present results from a study of key …


Carbonatites As A Record Of The Carbon Isotope Composition Of Large Igneous Province Outgassing, Ellen Gales Jan 2019

Carbonatites As A Record Of The Carbon Isotope Composition Of Large Igneous Province Outgassing, Ellen Gales

Dissertations and Theses

Large igneous province (LIP) eruptions have been linked in some cases to major perturbations of Earth’s carbon cycle. However, few observations directly constrain the isotopic composition of carbon released by LIP magmas because carbon isotopes fractionate during degassing, which hampers understanding of the relative roles of mantle versus crustal carbon reservoirs. Carbonatite magmatism associated with LIPs provides a unique window into the isotopic systematics of LIP carbon because the majority of carbon in carbonatites crystalizes rather than degassing. Here, we present new δ13C data for the Guli carbonatites in the Siberian Traps. In addition, we compile ~260 published …


Quantifying Magma Recharge At Parinacota Volcano, Northern Chile (52 Ka - Recent): Insight From The Magma Chamber Simulator, Jennifer Mcleod Jan 2019

Quantifying Magma Recharge At Parinacota Volcano, Northern Chile (52 Ka - Recent): Insight From The Magma Chamber Simulator, Jennifer Mcleod

All Master's Theses

The Magma Chamber Simulator (MCS; Bohrson et al., 2014) was used to produce new thermodynamic models that constrain and quantify recharge and fractional crystallization (RFC) processes for the Old Cone (OC; 52-20 ka; 56-66 wt.% SiO2) and Healing Flows (HF; >8 ka-recent; 58-64 wt.% SiO2) eruptive stages of Parinacota volcano, northern Chile. Using the MCS, over 200 RFC models were produced that constrain host magma initial conditions, including pressure, fO2 and H2O, and host and recharge magma masses, temperatures and compositions. A Rhyolite Domes (RD; 47-40 ka; 74 wt.% SiO2) …


Linking Historical, Field, And Satellite Data To Determine The Relationship Between Gas Emissions And Vegetation Change In The Puhimau Geothermal Area East Rift Zone Kilauea, Hawaii, Christie Torres Rosa Jan 2019

Linking Historical, Field, And Satellite Data To Determine The Relationship Between Gas Emissions And Vegetation Change In The Puhimau Geothermal Area East Rift Zone Kilauea, Hawaii, Christie Torres Rosa

Dissertations, Master's Theses and Master's Reports

The Puhimau geothermal area, located near the summit of the Kilauea volcano, Hawaii, has been suggested to represent a ‘window’ into the East Rift Zone. The quantification of CO2 and H2S soil gas emissions improves our understanding of its gas emission mode- including total emission and spatial distribution and contribute to a more accurate estimation of total CO2 and H2S in the thermal area – and how these gas emissions relate to observed vegetation health from satellite data. The total emission of CO2 and H2S was interpolated by the sequential Gaussian …


Seismic Signals And Sources At Fuego Volcano, Guatemala During January 2012, Kyle Brill Jan 2019

Seismic Signals And Sources At Fuego Volcano, Guatemala During January 2012, Kyle Brill

Dissertations, Master's Theses and Master's Reports

Forecasting volcanic activity is challenging. The task is uniquely difficult at open vent volcanoes which present persistent low-level eruptions over long periods of time. Volcán de Fuego in Guatemala began its current eruptive episode in 1999. Fuego exhibited “background” levels of activity during January of 2012 when we installed a temporary monitoring network to produce a detailed baseline description of the volcano’s behavior. We accomplish this using data from two low-frequency microphone arrays, nine broadband (50 Hz to 30 second flat response) seismic stations, and visual time-lapse imagery collected over a period of ten days. We begin with a detailed …


Volatiles And Trace Element Contents In Melt Inclusions From The Zoned Green Tuff Ignimbrite (Pantelleria, Sicily): Petrological Inferences., Pierangelo Romano, John C. White, Alessandro Ciulla, Ida Di Carlo, Claudia D'Oriano, Patrizia Landi, Silvio G. Rotolo Jan 2019

Volatiles And Trace Element Contents In Melt Inclusions From The Zoned Green Tuff Ignimbrite (Pantelleria, Sicily): Petrological Inferences., Pierangelo Romano, John C. White, Alessandro Ciulla, Ida Di Carlo, Claudia D'Oriano, Patrizia Landi, Silvio G. Rotolo

EKU Faculty and Staff Scholarship

The island of Pantelleria is one of the best known localities of bimodal mafic-felsic magmatism (alkali basalt and trachyte-pantellerite). Among the felsic rocks, the coexistence in a single eruption of products of both trachyte and pantellerite compositions is limited to few occurrences, the Green Tuff (GT) ignimbrite being one of these. The GT is compositionally zoned from pantellerite (70.1 wt% SiO2, mol Na+K/Al = 1.86, 1871 ppm Zr) at the base to crystal-rich (>30 vol%) comenditic trachyte (63.4 wt% SiO2, mol Na+K/Al = 1.10, 265 ppm Zr) at the top, although the pantellertic compositions dominate the erupted volume. We …


The Leyva Canyon Volcano, Big Bend Ranch State Park, Presidio Co., Texas., John C. White, Kevin M. Urbanczyk, Kelly Watson Jan 2019

The Leyva Canyon Volcano, Big Bend Ranch State Park, Presidio Co., Texas., John C. White, Kevin M. Urbanczyk, Kelly Watson

EKU Faculty and Staff Scholarship

Leyva Canyon volcano is an Oligocene (37.3 to 27.1 Ma) trachyte shield volcano whose eruptive and volcaniclastic deposits of rhyolite and trachyte lavas, ash-flow tuffs, lahars, and associated sedimentary rocks comprise the Leyva Canyon Member of the Rawls Formation. The lavas and tuffs originated from vents located near the present-day "Bofecillos vent" in the central Bofecillos Mountains, approximately 5 km west of the Sauceda Ranger Station in Big Bend Ranch State Park in southernmost Presidio County, Texas. The pyroclastic and volcaniclastic units form the distinctive cliffs and caves at the periphery of the Bofecillos Mountains, with the caves developing in …


Regional Sulfur Isotope Study Of The Vms Deposits In The Penokean Volcanic Belt, Nicholas M. Moleski Dec 2018

Regional Sulfur Isotope Study Of The Vms Deposits In The Penokean Volcanic Belt, Nicholas M. Moleski

Masters Theses

The Penokean Volcanic Belt (PVB), located in northern Wisconsin and Upper Peninsula, Michigan hosts several volcanogenic massive sulfide deposits (VMS) including the well-known deposits of Flambeau and Crandon. The host rocks of the VMS deposits are Paleoproterozoic in age overlying Archean age basement rocks. This study provides δ34S (VCDT) values for the following deposits within the PVB; (1) Eisenbrey, (2) Schoolhouse, (3) Bend, (4) Flambeau, (5) Reef, (6) Horseshoe, and (7) Back Forty, and explains the distribution of δ34S values in the region.

The study reveals tight ranges of δ34S values for each deposit …


Compositional And Thermodynamic Variability In A Stratified Magma Chamber: Evidence From The Green Tuff Ignimbrite (Pantelleria, Italy)., Katarzyna M. Liszewska, John C. White, Ray Macdonald, Bogusław Bagiński Dec 2018

Compositional And Thermodynamic Variability In A Stratified Magma Chamber: Evidence From The Green Tuff Ignimbrite (Pantelleria, Italy)., Katarzyna M. Liszewska, John C. White, Ray Macdonald, Bogusław Bagiński

EKU Faculty and Staff Scholarship

The Green Tuff Ignimbrite, Pantelleria, is compositionally zoned from pantellerite at the base to comenditic trachyte at the top, the variation apparently representing an inverted vertical zonation in the pre-eruptive reservoir. The main phenocryst assemblages are alkali feldspar + olivine + clinopyroxene + ilmenite + apatite in the trachytes and alkali feldspar + aenigmatite + clinopyroxene + quartz in the rhyolites. Thermodynamic modelling indicates that the temperature range was ~900–700°C, fO2 FMQ –1.5 to FMQ –0.5 (where FMQ is fayalite–magnetite–quartz buffer) and aSiO2 (relative to quartz saturation) 0.74–1.00. Melt water contents ranged from ~1wt % in the trachytes to ~4wt …


Interpreting The Origin And Evolution Of ‘Karst’ Features From A Siliceous Hydrothermal Terrane: A Case Study From The Upper Geyser Basin In Yellowstone National Park, Usa, Kevin W. Blackwood, Lainee A. Sanders, Stacy I. Gantt-Blackwood Nov 2018

Interpreting The Origin And Evolution Of ‘Karst’ Features From A Siliceous Hydrothermal Terrane: A Case Study From The Upper Geyser Basin In Yellowstone National Park, Usa, Kevin W. Blackwood, Lainee A. Sanders, Stacy I. Gantt-Blackwood

International Journal of Speleology

The Upper Geyser Basin in Yellowstone National Park occurs over a siliceous hydrothermal terrane containing numerous hot springs and geysers. The pool and vent-conduit geometries of these hydrothermal features share a resemblance to conventional karst features known from other rock types, suggesting karst processes could be responsible for their origin and/or evolution. Hypogene speleogenesis is a cave-forming process in which the formation of caves is decoupled from and occurs independently of surface recharge. The geologic setting for hypogene speleogenesis typically occurs at the distal end of regional groundwater systems wherein the hydrogeology is manifested by ascending fluids and/or by geochemical …


Volcanic Glass As A Paleoenvironmental Proxy: Comparing Preparation Methods On Ashes From The Lee Of The Cascade Range In Oregon, Usa, Tessa Boe Carlson Jul 2018

Volcanic Glass As A Paleoenvironmental Proxy: Comparing Preparation Methods On Ashes From The Lee Of The Cascade Range In Oregon, Usa, Tessa Boe Carlson

Dissertations and Theses

Deuterium ratios (δD) of hydrated volcanic glass have been used to reconstruct paleoenvironments, although the reliability and proper sample preparation protocol have been debated. In this study, hydrated volcanic ash samples from the lee of the Cascades were prepared using two separate methods. Method 1 involves sonicating and rinsing samples with hydrochloric acid (HCl) followed by hand-selection of glass shards (125-212µm). Method 2 requires hydrochloric acid (HCl) and hydrofluoric acid (HF) abrasion as well as heavy liquid separation of shards (70-150µm). Method 2 produced more consistent results with decreased intra-replicate variability in both water content (-0.92 wt. %) and deuterium …


Extremely High Diversity Of Sulfate Minerals In Caves Of The Irazú Volcano (Costa Rica) Related To Crater Lake And Fumarolic Activity, Andrés Ulloa, Fernando Gázquez, Aurelio Sanz-Arranz, Jesús Medina, Fernando Rull, José María Calaforra, Guillermo E. Alvarado, María Martínez, Geoffroy Avard, J. Maarten De Moor, Jo De Waele Jun 2018

Extremely High Diversity Of Sulfate Minerals In Caves Of The Irazú Volcano (Costa Rica) Related To Crater Lake And Fumarolic Activity, Andrés Ulloa, Fernando Gázquez, Aurelio Sanz-Arranz, Jesús Medina, Fernando Rull, José María Calaforra, Guillermo E. Alvarado, María Martínez, Geoffroy Avard, J. Maarten De Moor, Jo De Waele

International Journal of Speleology

The caves of the Irazú volcano (Costa Rica), became accessible after the partial collapse of the NW sector of the Irazú volcano in 1994, offering the opportunity to investigate active minerogenetic processes in volcanic cave environments. We performed a detailed mineralogical and geochemical study of speleothems in the caves Cueva los Minerales and Cueva Los Mucolitos, both located in the northwest foothills of the main crater. Mineralogical analyses included X-ray diffraction (XRD) and Raman spectroscopy, while geochemical characterization used Energy Dispersive X-ray spectroscopy (EDX) coupled to Scanning Electron Microscopy (SEM). In addition, measurements of environmental parameters in the caves, …


Infrasound Tornillos Produced By Volcán Cotopaxi’S Deep Crater, J. B. Johnson, M. C. Ruiz, H. D. Ortiz, L. M. Watson, G. Viracucha, P. Ramon, M. Almeida Jun 2018

Infrasound Tornillos Produced By Volcán Cotopaxi’S Deep Crater, J. B. Johnson, M. C. Ruiz, H. D. Ortiz, L. M. Watson, G. Viracucha, P. Ramon, M. Almeida

CGISS Publications and Presentations

We characterize and interpret a new type of infrasound signal originating from the summit of Volcán Cotopaxi (Ecuador) that was primarily observed between September 2015 and March 2016, following the 2015 eruptive period. This infrasound waveform is a slowly decaying sinusoid with exceptional low-frequency (fp = 0.2 Hz) and high quality factor (Q = ~10) and resembles the shape of tornillo seismic waveforms. The repeating events, occurring about once per day in early 2016, are stable in frequency content, and we attribute them to excitation of a vertical-walled crater, with radius of about 125mand length of 300 …


Lava, Ash Flows, Mudslides And Nasty Gases: Good Reasons To Respect Volcanoes, Brittany Brand May 2018

Lava, Ash Flows, Mudslides And Nasty Gases: Good Reasons To Respect Volcanoes, Brittany Brand

Geosciences Faculty Publications and Presentations

Volcanoes are beautiful and awe-inspiring, but the ongoing eruption of Kilauea on Hawaii’s Big Island is showing how dangerous these events can be. So far this event has destroyed dozens of homes and displaced hundreds of people, but no deaths or serious injuries have been reported. Other volcanic eruptions have had deadlier impacts.


Estimation Of Porosity And Water Saturation In Dual-Porosity Pyroclastic Deposits From Joint Analysis Of Compression, Shear, And Electromagnetic Velocities, Andrew C. Gase, John H. Bradford, Brittany D. Brand May 2018

Estimation Of Porosity And Water Saturation In Dual-Porosity Pyroclastic Deposits From Joint Analysis Of Compression, Shear, And Electromagnetic Velocities, Andrew C. Gase, John H. Bradford, Brittany D. Brand

Geosciences Faculty Publications and Presentations

In situ measurements of porosity and water saturation of pyroclastic deposits have the potential to improve interpretations of geology and hydrology in volcanic regions, and to provide more accurate estimates of dense rock equivalent for volcanic eruptions. However, rock-property models must consider the dual-porosity structure of pyroclastic deposits (i.e., vesicles within pumices and intergranular pores). Vesicularity, intergranular porosity, and water saturation all affect the density, elasticity, and dielectric properties of pyroclastic materials, which control seismic and electromagnetic velocities. The data from active seismic and ground-penetrating radar (GPR) techniques may improve porosity and water saturation estimation if the responses of seismic …


Diverse Eruptive Activity Revealed By Acoustic And Electromagnetic Observations Of The 14 July 2013 Intense Vulcanian Eruption Of Tungurahua Volcano, Ecuador, J. F. Anderson, J. B. Johnson, A. L. Steele, M. C. Ruiz, B. D. Brand Apr 2018

Diverse Eruptive Activity Revealed By Acoustic And Electromagnetic Observations Of The 14 July 2013 Intense Vulcanian Eruption Of Tungurahua Volcano, Ecuador, J. F. Anderson, J. B. Johnson, A. L. Steele, M. C. Ruiz, B. D. Brand

CGISS Publications and Presentations

During the powerful July 2013 eruption of Tungurahua volcano, Ecuador, we recorded exceptionally high amplitude, long‐period infrasound (1,600‐Pa peak‐to‐peak amplitude, 5.5‐s period) on sensors within 2km of the vent alongside electromagnetic signals from volcanic lightning serendipitously captured as interference. This explosion was one of Tungurahua's most powerful vulcanian eruptions since recent activity began in 1999, and its acoustic wave is among the most powerful volcanic infrasound ever recorded anywhere. We use these data to quantify erupted volume from the main explosion and to classify postexplosive degassing into distinct emission styles. Additionally, we demonstrate a highly effective method of recording lightning‐related …


Areal Extent And Volumes Of The Dinner Creek Tuff Units, Eastern Oregon Based On Lithology, Bulk Rock Composition And Feldspar Mineralogy, Teresa Rae Hanna Apr 2018

Areal Extent And Volumes Of The Dinner Creek Tuff Units, Eastern Oregon Based On Lithology, Bulk Rock Composition And Feldspar Mineralogy, Teresa Rae Hanna

Dissertations and Theses

The Dinner Creek Tuff erupted during a period of rhyolitic volcanism coeval to the flood volcanism associated with the Columbia River Basalt Group. The High Rock Caldera Complex, Lake Owyhee and McDermitt volcanic fields account for ~90% of the rhyolites erupted between 16.7-15.0 Ma. Situated at the northern end of the Lake Owyhee volcanic field, the Dinner Creek Tuff was originally mapped as a ~2,000 km2 single ignimbrite confined to the Malheur Gorge. Streck et al. (2015) correlated tuff outcrops previously mapped as generic Miocene welded tuff as well as local units such as the "Mascall" or "Pleasant Valley" …


Forecasting The Eruption Of An Open‐Vent Volcano Using Resonant Infrasound Tones, Jeffrey B. Johnson, Leighton M. Watson, Jose L. Palma, Eric M. Dunham, Jacob F. Anderson Mar 2018

Forecasting The Eruption Of An Open‐Vent Volcano Using Resonant Infrasound Tones, Jeffrey B. Johnson, Leighton M. Watson, Jose L. Palma, Eric M. Dunham, Jacob F. Anderson

CGISS Publications and Presentations

Open‐vent volcanic systems with active degassing are particularly effective at producing infrasound that exhibits resonant tones controlled by the geometry of the volcano's crater. Changes in the infrasound character can thus provide constraints on a crater's lava level, which may vary dynamically in the lead‐up to an eruption. Here we show that the increasing frequency content and damping characteristics of the resonant infrasound at Volcán Villarrica (Chile) relate to lava lake position in its crater/conduit preceding its 2015 eruption. We model the acoustic response of Villarrica's crater to determine that the lake began to rise on 27 February and reached …


Trace Element And Isotopic Fingerprinting Of Olivine Phenocrysts As Recorders Of Magmatic Processes In The Golden Trout Volcanic Field, Kern Plateau, Ca, Mark E. Szymanski Jan 2018

Trace Element And Isotopic Fingerprinting Of Olivine Phenocrysts As Recorders Of Magmatic Processes In The Golden Trout Volcanic Field, Kern Plateau, Ca, Mark E. Szymanski

Cal Poly Humboldt theses and projects

Quaternary mafic volcanism in the western Basin and Range and in the southeastern Sierra Nevada is largely controlled by extensional stresses that promote magma generation through decompression melting of the lithospheric and asthenospheric mantle. Where volcanism occurs in the Sierra Nevada, like at the Golden Trout Volcanic Field GTVF), the eruption rate, number of vents, and eruption volume is an order of magnitude less than at neighboring Basin and Range volcanic fields such as the Big Pine Volcanic Field (BPVF). To determine the factors that cause these differences in adjacent and contemporaneous volcanic fields, I sampled rocks from both fields …


Giant Plagioclase In The Steens Basalt, Se Oregon: Cumulate Entrainment Revealed By Textural And In Situ Chemical Analysis, Conner H. Toth Jan 2018

Giant Plagioclase In The Steens Basalt, Se Oregon: Cumulate Entrainment Revealed By Textural And In Situ Chemical Analysis, Conner H. Toth

All Master's Theses

Many of the lava flows comprising the Steens Basalt in SE Oregon, the oldest and most mafic formation of the Columbia River Basalt Group (CRBG), contain exceptionally large (up to 5 cm) and abundant (up to 40 modal %) plagioclase crystals. This thesis presents a model for giant plagioclase formation in a complex system that integrates petrographic and in situ plagioclase compositional analyses with whole-rock data and computational modeling to explain systematic textural and chemical differences between plagioclase of the lower and upper Steens Basalt sub-sections. Lower Steens plagioclase are typically more chemically homogenous than upper Steens plagioclase and exhibit …


A New Approach To Probabilistic Lava Flow Hazard Assessments, Applied To The Idaho National Laboratory, Eastern Snake River Plain, Idaho, Usa, Elisabeth Gallant, Jacob Richardson, Charles Connor, Paul Wetmore, Laura Connor Jan 2018

A New Approach To Probabilistic Lava Flow Hazard Assessments, Applied To The Idaho National Laboratory, Eastern Snake River Plain, Idaho, Usa, Elisabeth Gallant, Jacob Richardson, Charles Connor, Paul Wetmore, Laura Connor

School of Geosciences Faculty and Staff Publications

We present a new probabilistic lava flow hazard assessment for the U.S. Department of Energy’s Idaho National Laboratory (INL) nuclear facility that (1) explores the way eruptions are defined and modeled, (2) stochastically samples lava flow parameters from observed values for use in MOLASSES, a lava flow simulator, (3) calculates the likelihood of a new vent opening within the boundaries of INL, (4) determines probabilities of lava flow inundation for INL through Monte Carlo simulation, and (5) couples inundation probabilities with recurrence rates to determine the annual likelihood of lava flow inundation for INL. Results show a 30% probability of …