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Boise State University

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Articles 31 - 60 of 524

Full-Text Articles in Geophysics and Seismology

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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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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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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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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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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Early Ordovician Seamounts Preserved In The Canadian Cordillera: Implications For The Rift History Of Western Laurentia, Rose N. Cobbett, Luke P. Beranek, Stephen J. Piercey, James L. Crowley, Maurice Colpron Oct 2023

Early Ordovician Seamounts Preserved In The Canadian Cordillera: Implications For The Rift History Of Western Laurentia, Rose N. Cobbett, Luke P. Beranek, Stephen J. Piercey, James L. Crowley, Maurice Colpron

Geosciences Faculty Publications and Presentations

The breakup of the supercontinent Rodinia and development of the western Laurentian rifted margin are in part recorded by Neoproterozoic to mid-Paleozoic igneous and sedimentary rock successions in the Canadian Cordillera. New bedrock mapping and volcanic facies analysis of Early Ordovician mafic rocks assigned to the Menzie Creek Formation in central Yukon allow reconstruction of the depositional environment during the volcanic eruptions, whole-rock geochemical data constrain the melting depth and crust-mantle source regions of the igneous rocks within the study area, and zircon U-Pb age studies provide determination of the precise timing of submarine eruptions. Menzie Creek Formation volcanic rocks …

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Assessing Controls On Ice Dynamics At Crane Glacier, Antarctic Peninsula, Using A Numerical Ice Flow Model, Rainey Aberle, Ellyn M. Enderlin, Hans-Peter Marshall, Michal Kopera, Tate G. Meehan Oct 2023

Assessing Controls On Ice Dynamics At Crane Glacier, Antarctic Peninsula, Using A Numerical Ice Flow Model, Rainey Aberle, Ellyn M. Enderlin, Hans-Peter Marshall, Michal Kopera, Tate G. Meehan

Geosciences Faculty Publications and Presentations

The Antarctic Peninsula's widespread glacier retreat and ice shelf collapse have been attributed to atmospheric and oceanic warming. Following the initial post-collapse period of retreat, several former tributary glaciers of the Larsen A and B ice shelves have been slowly re-advancing for more than a decade. Here, we use a flowline model of Crane Glacier to gauge the sensitivity of former tributary glaciers to future climate change following this period of long-term dynamic adjustment. The glacier's long-term geometry and speed changes are similar to those of other former Larsen A and B tributaries, suggesting that Crane Glacier is a reasonable …

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The Influence Of Volcano Topographic Changes On Infrasound Amplitude: Lava Fountains At Mt. Etna In 2021, Adriana Iozzia, Leighton M. Watson, Massimo Cantarero, Emanuela De Beni, Giuseppe Di Grazia, Gaetana Ganci, Jeffrey B. Johnson, Eugenio Privitera, Cristina Proietti, Mariangela Sciotto, Andrea Cannata Oct 2023

The Influence Of Volcano Topographic Changes On Infrasound Amplitude: Lava Fountains At Mt. Etna In 2021, Adriana Iozzia, Leighton M. Watson, Massimo Cantarero, Emanuela De Beni, Giuseppe Di Grazia, Gaetana Ganci, Jeffrey B. Johnson, Eugenio Privitera, Cristina Proietti, Mariangela Sciotto, Andrea Cannata

Geosciences Faculty Publications and Presentations

Infrasound signals are used to investigate and monitor active volcanoes during eruptive and degassing activity. Infrasound amplitude information has been used to estimate eruptive parameters such as plume height, magma discharge rate, and lava fountain height. Active volcanoes are characterized by pronounced topography and, during eruptive activity, the topography can change rapidly, affecting the observed infrasound amplitudes. While the interaction of infrasonic signals with topography has been widely investigated over the past decade, there has been limited work on the impact of changing topography on the infrasonic amplitudes. In this work, the infrasonic signals accompanying 57 lava fountain paroxysms at …

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Archean (3.3 Ga) Paleosols And Paleoenvironments Of Western Australia, Gregory J. Retallack, Mark D. Schmitz Sep 2023

Archean (3.3 Ga) Paleosols And Paleoenvironments Of Western Australia, Gregory J. Retallack, Mark D. Schmitz

Geosciences Faculty Publications and Presentations

The Pilbara craton of northwestern Australia is known for what were, when reported, the oldest known microfossils and paleosols on Earth. Both interpretations are mired in controversy, and neither remain the oldest known. Both the microfossils and the paleosols have been considered hydrothermal artefacts: carbon films of vents and a large hydrothermal cupola, respectively. This study resampled and analyzed putative paleosols within and below the Strelley Pool Formation (3.3 Ga), at four classic locations: Strelley Pool, Steer Ridge, Trendall Ridge, and Streckfuss, and also at newly discovered outcrops near Marble Bar. The same sequence of sedimentary facies and paleosols was …

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Constraints On Near-Ridge Magmatism Using 40Ar/39Ar Geochronology Of Enriched Morb From The 8°20' N Seamount Chain, Molly K. Anderson, Michael R. Perfit, Leah E. Morgan, Daniel J. Fornari, Michael Cosca, V. Dorsey Wanless Sep 2023

Constraints On Near-Ridge Magmatism Using 40Ar/39Ar Geochronology Of Enriched Morb From The 8°20' N Seamount Chain, Molly K. Anderson, Michael R. Perfit, Leah E. Morgan, Daniel J. Fornari, Michael Cosca, V. Dorsey Wanless

Geosciences Faculty Publications and Presentations

Our understanding of the spatial-temporal-compositional relationships between off-axis magmatism and mid-ocean ridge spreading centers is limited. Determining the 40Ar/39Ar ages of mid-ocean ridge basalt (MORB) lavas erupting near mid-ocean ridges (MOR) has been a challenge due to the characteristically low K2O contents in incompatible element-depleted normal MORB (NMORB). High-precision 40Ar/39Ar geochronology is used here to determine ages of young, basaltic lavas erupted along the 8°20' N seamount chain west of the East Pacific Rise (EPR) axis that have a range of incompatible element enrichments (EMORB) suitable for 40Ar/39Ar geochronology …

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Is Macroporosity Controlled By Complexed Clay And Soil Organic Carbon?, Aaron N. Koop, Daniel R. Hirmas, Sharon A. Billings, Li Li, Alejandro Cueva, Xi Zhang, Hang Wen, Attila Nemes, Lígia F. T. Souza, Hoori Ajami, Alejandro N. Flores, Aoesta K. Rudick, Annalise Guthrie, Lola M. Klamm, Micah Unruh, Pamela L. Sullivan Sep 2023

Is Macroporosity Controlled By Complexed Clay And Soil Organic Carbon?, Aaron N. Koop, Daniel R. Hirmas, Sharon A. Billings, Li Li, Alejandro Cueva, Xi Zhang, Hang Wen, Attila Nemes, Lígia F. T. Souza, Hoori Ajami, Alejandro N. Flores, Aoesta K. Rudick, Annalise Guthrie, Lola M. Klamm, Micah Unruh, Pamela L. Sullivan

Geosciences Faculty Publications and Presentations

Multi-scale evidence of rapid, climate-induced soil structural changes occurring at yearly to decadal timescales is mounting. As a result, it has become increasingly important to identify the properties and mechanisms controlling the development and maintenance of soil structure and associated macroporosity. This is especially relevant since macroporosity has disproportionate effects on saturated hydraulic conductivity (Ksat) which strongly influences water storage and flux, thus, affecting the water cycle. In this study, we use decision trees and piecewise linear regression to assess the influence of soil and climate properties on effective porosity (EP; a proxy of macroporosity) in both …

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U-Pb Zircon Dates From North American And British Avalonia Bracket The Lower–Middle Cambrian Boundary Interval, With Evaluation Of The Miaolingian Series As A Global Unit, Ed Landing, Mark D. Schmitz, Stephen R. Westrop, Gerd Geyer Sep 2023

U-Pb Zircon Dates From North American And British Avalonia Bracket The Lower–Middle Cambrian Boundary Interval, With Evaluation Of The Miaolingian Series As A Global Unit, Ed Landing, Mark D. Schmitz, Stephen R. Westrop, Gerd Geyer

Geosciences Faculty Publications and Presentations

High-precision U-Pb zircon ages on SE Newfoundland tuffs now bracket the Avalonian Lower–Middle Cambrian boundary. Upper Lower Cambrian Brigus Formation tuffs yield depositional ages of 507.91 ± 0.07 Ma (Callavia broeggeri Zone) and 507.67 ± 0.08 Ma and 507.21 ± 0.13 Ma (Morocconus-Condylopyge eli Assemblage interval). Lower Middle Cambrian Chamberlain’s Brook Formation tuffs have depositional ages of 506.34 ± 0.21 Ma (Kiskinella cristata Zone) and 506.25 ± 0.07 Ma (Eccaparadoxides bennetti Zone). The composite unconformity separating the Brigus and Chamberlain’s Brook formations is constrained between these ages. An Avalonian Lower–Middle Cambrian boundary between 507.2 ± 0.1 …

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The Temporal Evolution Of Subduction Initiation In The Samail Ophiolite: High-Precision U–Pb Zircon Petrochronology Of The Metamorphic Sole, Matthew Rioux, Joshua M. Garber, Michael Searle, James L. Crowley, Sally Stevens, Mark Schmitz, Andrew Kylander-Clark, Kayla Leal, Tyler Ambrose, Andrew J. Smye Aug 2023

The Temporal Evolution Of Subduction Initiation In The Samail Ophiolite: High-Precision U–Pb Zircon Petrochronology Of The Metamorphic Sole, Matthew Rioux, Joshua M. Garber, Michael Searle, James L. Crowley, Sally Stevens, Mark Schmitz, Andrew Kylander-Clark, Kayla Leal, Tyler Ambrose, Andrew J. Smye

Geosciences Faculty Publications and Presentations

High-precision dating of the metamorphic sole of ophiolites can provide insight into the tectonic evolution of ophiolites and subduction zone processes. To understand subduction initiation beneath a young, well-preserved and well-characterized ophiolite, we performed coupled zircon laser-ablation inductively coupled mass spectrometry trace element analyses and high-precision isotope dilution-thermal ionization mass spectrometry U–Pb dating on 25 samples from the metamorphic sole of the Samail ophiolite (Oman-United Arab Emirates). Zircon grains from amphibolite- to granulite-facies (0.8–1.3 GPa, ~700–900°C), garnet- and clinopyroxene-bearing amphibolite samples (n = 18) show systematic trends of decreasing heavy rare earth element slope (HREE; Yb/Dy) with decreasing Yb …

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Uav-Based Quantification Of Dynamic Lahar Channel Morphology At Volcán De Fuego, Guatemala, Jerry C. Mock, Jeffrey B. Johnson, Armando Pineda, Gustavo Bejar, Amilcar Roca Aug 2023

Uav-Based Quantification Of Dynamic Lahar Channel Morphology At Volcán De Fuego, Guatemala, Jerry C. Mock, Jeffrey B. Johnson, Armando Pineda, Gustavo Bejar, Amilcar Roca

Geosciences Faculty Publications and Presentations

This study quantified erosional and depositional processes for secondary lahars in Las Lajas drainage at Volcán de Fuego, Guatemala, during the rainy season from May to October 2021. Abundant pyroclastic material from ongoing eruptive activity is remobilized seasonally during heavy precipitation, which can impact infrastructure and populations living near Fuego. Our region of focus was in an agricultural zone 6 to 10 km from the summit, surveyed with an unoccupied aerial vehicle (UAV) quadcopter at monthly intervals. Imagery was processed into overlapping time-lapse structure from motion digital elevation models (DEMs). DEMs were differenced to find volumetric changes as a function …

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Revisiting The Diffuse Layer Polarization Of A Spherical Grain In Electrolytes With Numerical Solutions Of Nernst-Planck-Poisson Equations, Qifei Niu Aug 2023

Revisiting The Diffuse Layer Polarization Of A Spherical Grain In Electrolytes With Numerical Solutions Of Nernst-Planck-Poisson Equations, Qifei Niu

Geosciences Faculty Publications and Presentations

Induced polarization (IP) has been frequently used in solid earth geophysics, hydrology, and environmental sciences. A mechanistic understanding of the IP responses of geological materials is crucial for correctly interpreting field IP measurements. In this study, the fully-coupled, nonlinear Nernst-Planck-Poisson equations are numerically solved to analyze the electrochemical mechanism of diffuse layer polarization around a spherical grain immersed in electrolytes. The numerical results show diffuse layer polarization is formed by the charge separation between counterions in the diffuse layer and charges on the grain surface. Both tangential and normal movements of counterions in the diffuse layer are involved in the …

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Whitewater Sound Dependence On Discharge And Wave Configuration At An Adjustable Wave Feature, Taylor A. Tatum, Jacob F. Anderson, Timothy J. Ronan Aug 2023

Whitewater Sound Dependence On Discharge And Wave Configuration At An Adjustable Wave Feature, Taylor A. Tatum, Jacob F. Anderson, Timothy J. Ronan

Geosciences Faculty Publications and Presentations

Stream acoustics has been proposed as a means of monitoring discharge and wave hazards from outside the stream channel. To better understand the dependence of sound on discharge and wave characteristics, this study analyzes discharge and infrasound data from an artificial wave feature which is adjusted to accommodate daily changes in recreational use and seasonal changes in irrigation demand. Monitorable sound is only observed when discharge exceeds ∼35 m3/s, and even above that threshold the sound-discharge relationship is non-linear and inconsistent. When sound is observed, it shows consistent dependence on wave type within a given year, but the …

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Effects Of Discharge And Morphology On Fluvial Sound, Scott J. Gauvain Aug 2023

Effects Of Discharge And Morphology On Fluvial Sound, Scott J. Gauvain

Boise State University Theses and Dissertations

Rivers, streams, and tributaries play a critical role in the global water cycle and their dispersion of freshwater is essential for widespread human consumption, crop irrigation, waste management, and hydropower generation. Currently, there is a need for innovative, non-invasive, and low-cost methods of surface freshwater discharge gauging. With careful site selection, recording the acoustics produced by streamflow could be used reliably and inexpensively to infer changes in local discharge. An important knowledge gap currently preventing the use of acoustics for stream gauging is the unknown relationships by which stream sounds depend on discharge and stream morphology. To address this, I …

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Cambrian Explosion Condensed: High-Precision Geochronology Of The Lower Wood Canyon Formation, Nevada, Lyle L. Nelson, James L. Crowley, Emily F. Smith, Darin M. Schwartz, Eben B. Hodgin, Mark D. Schmitz Jul 2023

Cambrian Explosion Condensed: High-Precision Geochronology Of The Lower Wood Canyon Formation, Nevada, Lyle L. Nelson, James L. Crowley, Emily F. Smith, Darin M. Schwartz, Eben B. Hodgin, Mark D. Schmitz

Geosciences Faculty Publications and Presentations

The geologically rapid appearance of fossils of modern animal phyla within Cambrian strata is a defining characteristic of the history of life on Earth. However, temporal calibration of the base of the Cambrian Period remains uncertain within millions of years, which has resulted in mounting challenges to the concept of a discrete Cambrian explosion. We present precise zircon U–Pb dates for the lower Wood Canyon Formation, Nevada. These data demonstrate the base of the Cambrian Period, as defined by both ichnofossil biostratigraphy and carbon isotope chemostratigraphy, was younger than 533 Mya, at least 6 My later than currently recognized. This …

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Brief Communication: Is Vertical Shear In An Ice Shelf (Still) Negligible?, Chris Miele, Timothy C. Bartholomaus, Ellyn M. Enderlin Jul 2023

Brief Communication: Is Vertical Shear In An Ice Shelf (Still) Negligible?, Chris Miele, Timothy C. Bartholomaus, Ellyn M. Enderlin

Geosciences Faculty Publications and Presentations

Vertical shear is recognized today as a key component of the stress balance of ice shelves. However, the first ice shelf models were built on the neglect of vertical shear. Partly due to its historical treatment, it remains common to discuss vertical shear as though it were still considered negligible in ice shelf models. Here, we offer a historical perspective on the changing treatment of vertical shear over time, and we emphasize the term's non-negligibility in current ice shelf modeling. We illustrate our discussion in the simplest context of an analytic, isothermal, shallow-ice-shelf model.

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Early Permian Zircon Ages From The P. Confluens And P. Pseudoreticulata Spore-Pollen Zones In The Southern Bonaparte And Canning Basins, Northwestern Australia, A. J. Mory, J. Crowley, J. Backhouse, R. S. Nicoll, J. D. Gorter Jun 2023

Early Permian Zircon Ages From The P. Confluens And P. Pseudoreticulata Spore-Pollen Zones In The Southern Bonaparte And Canning Basins, Northwestern Australia, A. J. Mory, J. Crowley, J. Backhouse, R. S. Nicoll, J. D. Gorter

Geosciences Faculty Publications and Presentations

The Pseudoreticulatispora confluens–P. pseudoreticulata spore-pollen zonal datum typically coincides with the end of widespread Permian glacial deposits in Western Australia. Although previously attributed to the mid-Sakmarian, chemical abrasion isotope dilution thermal ionisation mass spectrometry (TIMS) dating of zircons from volcanic tuffs in the Ditji Formation of the Bonaparte Basin and the Grant Group in the Canning Basin point to an Asselian age of about 295.25 Ma for this datum. All dated zircons from the Ditji Formation came from petroleum well cuttings but the accompanying palynology was mostly from sidewall cores; however, all Grant Group samples were from conventional core. TIMS …

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Apatite Reference Materials For Sims Microanalysis Of Isotopes And Trace Elements, James L. Crowley, Mark Schmitz Jun 2023

Apatite Reference Materials For Sims Microanalysis Of Isotopes And Trace Elements, James L. Crowley, Mark Schmitz

Geosciences Faculty Publications and Presentations

Twelve apatite samples have been tested as secondary ion mass spectrometry (SIMS) reference materials. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) analysis shows that the SLAP, NUAN and GR40 apatite gems are internally homogeneous, with most trace element mass fractions having 2 standard deviations (2s) ≤ 2.0%. BR2, BR5, OL2, AFG2 and AFB1, which have U > 63 μg g-1, 206Pb/204Pb > 283, and homogeneous SIMS U-Pb data, have respective isotope dilution thermal ionisation mass spectrometry (ID-TIMS) ages of 2053.83 ± 0.21 Ma, 2040.34 ± 0.09 Ma, 868.87 ± 0.25 Ma, 478.71 ± 0.22 Ma and …

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Estimating Snow Accumulation And Ablation With L-Band Interferometric Synthetic Aperture Radar (Insar), Jack Tarricone, Ryan W. Webb, Hans-Peter Marshall, Anne W. Nolin, Franz J. Meyer May 2023

Estimating Snow Accumulation And Ablation With L-Band Interferometric Synthetic Aperture Radar (Insar), Jack Tarricone, Ryan W. Webb, Hans-Peter Marshall, Anne W. Nolin, Franz J. Meyer

Geosciences Faculty Publications and Presentations

Snow is a critical water resource for the western United States and many regions across the globe. However, our ability to accurately measure and monitor changes in snow mass from satellite remote sensing, specifically its water equivalent, remains a challenge. To confront these challenges, NASA initiated the SnowEx program, a multiyear effort to address knowledge gaps in snow remote sensing. During SnowEx 2020, the Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) team acquired an L-band interferometric synthetic aperture radar (InSAR) data time series to evaluate the capabilities and limitations of repeat-pass L-band InSAR for tracking changes in snow water equivalent …

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Volcano Opto-Acoustics: Mapping The Infrasound Wavefield At Yasur Volcano (Vanuatu), J. B. Johnson, T. Boyer, L. M. Watson, J. F. Anderson Apr 2023

Volcano Opto-Acoustics: Mapping The Infrasound Wavefield At Yasur Volcano (Vanuatu), J. B. Johnson, T. Boyer, L. M. Watson, J. F. Anderson

Geosciences Faculty Publications and Presentations

We explore the capabilities of volcano opto-acoustics, a promising technique for measuring explosion and infrasound resonance phenomena at open-vent volcanoes. Joint visual and infrasound study at Yasur Volcano (Vanuatu) demonstrate that even consumer-grade cameras are capable of recording infrasound with high fidelity. Passage of infrasonic waves, ranging from as low as 5 Pa to hundreds of Pa, from both explosions and persistent tremor, pressurizes and depressurizes ambient plumes inducing visible vaporization and condensation respectively. Optical tracking of these pressure wavefields can be used to identify spectral characteristics, which vary within Yasur's two deep craters and are distinct for explosion and …

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Infrasound Detection Of Approaching Lahars, J. B. Johnson, J. F. Anderson, J. Mock, A. Bosa Apr 2023

Infrasound Detection Of Approaching Lahars, J. B. Johnson, J. F. Anderson, J. Mock, A. Bosa

Geosciences Faculty Publications and Presentations

Infrasound may be used to detect the approach of hazardous volcanic mudflows, known as lahars, tens of minutes before their flow fronts arrive. We have analyzed signals from more than 20 secondary lahars caused by precipitation events at Fuego Volcano during Guatemala’s rainy season in May through October of 2022. We are able to quantify the capabilities of infrasound monitoring through comparison with seismic data, time lapse camera imagery, and high-resolution video of a well-recorded event on August 17. We determine that infrasound sensors, deployed adjacent to the lahar path and in small-aperture (10 s of meters) arrays, are particularly …

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New U–Pb Geochronology For The Central Atlantic Magmatic Province, Critical Reevaluation Of High-Precision Ages And Their Impact On The End-Triassic Extinction Event, Alisson L. Oliveira, Mark D. Schmitz, Corey J. Wall, James L. Crowley, Antomat A. Macêdo Filho, Maria Helena B. M. Hollanda Apr 2023

New U–Pb Geochronology For The Central Atlantic Magmatic Province, Critical Reevaluation Of High-Precision Ages And Their Impact On The End-Triassic Extinction Event, Alisson L. Oliveira, Mark D. Schmitz, Corey J. Wall, James L. Crowley, Antomat A. Macêdo Filho, Maria Helena B. M. Hollanda

Geosciences Faculty Publications and Presentations

The end-Triassic extinction (ETE) event represents one of the ‘big five’ episodes of mass extinction. The leading hypothesis for the cause of the ETE is the intrusion of voluminous magmas of the Central Atlantic Magmatic Province (CAMP) into carbon-rich sediments of two South American sedimentary basins, around 201.5 Ma. The timing of dikes and sills emplacement, however, must be considered in light of age models from CAMP rocks occurring in North America. In this work, we present new high-precision ages for critical samples in NE Brazil (201.579 ± 0.057 Ma) and Canada (201.464 ± 0.017 Ma), in order to evaluate …

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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 …

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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 …

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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, …

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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 …

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