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Full-Text Articles in Geology

Reflectance Spectroscopy Datasets For The Validation Of Tanager, Kristiana Lapo, Kathleen Hoza, Sammy Theuer, Melissa S. Rice Apr 2024

Reflectance Spectroscopy Datasets For The Validation Of Tanager, Kristiana Lapo, Kathleen Hoza, Sammy Theuer, Melissa S. Rice

Geology Faculty Publications

The Three-Axis N-sample Automated Goniometer for Evaluating Reflectance (TANAGER) is a custom goniometer designed to rapidly acquire spectra of natural rock surfaces across the full scattering hemisphere. TANAGER interfaces with a Malvern Panalytical ASD Fieldspec 4 Hi-Res reflectance spectrometer to collect data from 350-2500 nm at a range of incidence, emission and azimuth angles. To validate the accuracy and repeatability of data collected with TANAGER - and to characterize any instrument noise, artifacts or sample heating effects - we collected spectra from three categories of targets: (1) powdered calcium sulfate (anhydrite), (2) naturally weathered basalt surfaces, and (3) color calibration …


Deglacial And Holocene Environmental Change Recorded In Lake Sediments From The Snowy Mountains, Kosciuszko National Park, Southeastern Australia, Emma J. Mickelson Jan 2024

Deglacial And Holocene Environmental Change Recorded In Lake Sediments From The Snowy Mountains, Kosciuszko National Park, Southeastern Australia, Emma J. Mickelson

WWU Graduate School Collection

The sediment record from Lake Albina, the Snowy Mountains, southeastern Australia suggests significant environmental change mostly reflecting shifts in climate from the LGM through the Holocene. Immediately following deglaciation, approximately 19.4 thousand cal ky BP, Lake Albina experienced cold and/or dry conditions with minimal vegetation in the catchment. Cooler conditions persisted with a slight increase in moisture throughout the Antarctic Cold Reversal (ACR; 14.7-13 cal ky BP) aligning closest with a strengthening of the Atlantic Meridional overturning circulation (AMOC) and a northward shift of the South Westerly Winds (SWW). Between 12.9-9.7 cal ky BP, Lake Albina recorded a climate reversal …


Using Trace Element Concentrations In Volcanic Ash To Elucidate Magma Sources To Koma Kulshan’S (Mount Baker) Most Recent Explosive Eruption – The 6.7 Ka Ba (Black Ash) Tephra, Stone Machel Oct 2023

Using Trace Element Concentrations In Volcanic Ash To Elucidate Magma Sources To Koma Kulshan’S (Mount Baker) Most Recent Explosive Eruption – The 6.7 Ka Ba (Black Ash) Tephra, Stone Machel

Geology Graduate and Undergraduate Student Scholarship

Koma Kulshan (Mount Baker) is an active stratovolcano in the northern Washington Cascades. Kulshan’s most recent magmatic eruption at 6.7 ka was explosive, producing the ~0.2 km3 BA tephra (black ash) from the edifice (Scott et al. 2019). Comprehensive geochemical data for the BA tephra were previously limited to major elements from one whole rock lapillus (silicic andesite) and several in situ glass analyses (dacite), despite being Kulshan’s most voluminous Holocene tephra. Here, I present the first extensive major and trace element study of the pyroxene- and plagioclase-bearing BA tephra glass to determine magma source and eruption processes. My …


Shared Roots: A Geochemical Investigation Of Basaltic Andesites To Understand Magmatic Cogenesis At The Middle Sister And South Sister Volcanoes, Central Oregon, Sean Francis Halstead Oct 2023

Shared Roots: A Geochemical Investigation Of Basaltic Andesites To Understand Magmatic Cogenesis At The Middle Sister And South Sister Volcanoes, Central Oregon, Sean Francis Halstead

WWU Honors College Senior Projects

The Middle Sister and South Sister volcanoes, near Bend, Oregon, are overlapping, active Cascade Arc stratovolcanoes which share a complex, contemporaneous eruptive history. This history is characterized by an extreme compositional diversity of lavas erupted in alternating phases of high activity from one neighboring volcano to the other, with both vents producing material ranging from basaltic andesite to rhyolite. This system is understood to be predominantly fed by basaltic andesites fractionated from partial mantle melts within the lower crust, but magma compositions are additionally impacted by mixing, assimilation, and crustal contamination while in transit to the surface. Thus, the subterranean …


An Analysis Of Clinopyroxene Reaction Rims As Assimilation Chronometers At Cinder Cone Volcano, Lassen National Volcanic Park, California, Annabelle Carozza Oct 2023

An Analysis Of Clinopyroxene Reaction Rims As Assimilation Chronometers At Cinder Cone Volcano, Lassen National Volcanic Park, California, Annabelle Carozza

WWU Honors College Senior Projects

Cinder Cone is a monogenetic cinder cone volcano located in Lassen National Volcanic Park, California. It erupted in 1666 CE and had three eruptive phases, each producing tephra and lava flows that ranged in style from Hawaiian (low explosivity) to Strombolian (moderate to high explosivity). This eruptive style variability at Cinder Cone was not caused by viscosity or volatile differences, and ascent rate has been proposed as a causal factor in the observed explosivity difference between phases. Ubiquitous quartz crystals are entrained within tephra and lava and were likely sourced from the assimilation of a granitic basement rock underlying the …


Using Two Coeval Andesites From Middle Sister And South Sister, Oregon, As Clues To Understanding Connectivity Between Adjacent, Coincident Stratovolcanoes, James Peale Jun 2023

Using Two Coeval Andesites From Middle Sister And South Sister, Oregon, As Clues To Understanding Connectivity Between Adjacent, Coincident Stratovolcanoes, James Peale

Geology Graduate and Undergraduate Student Scholarship

The Three Sisters Volcanic Complex in central Oregon is a cluster of three primary stratovolcanoes and a mafic periphery which lies at the intersection of the Cascade volcanic arc and the Basin and Range extensional province. This project focuses on the two youngest stratovolcanoes, Middle Sister and South Sister. Middle Sister experienced a period of frequent eruptive activity from approximately 27 ka to 14 ka, during which it erupted dacites, andesites, and basaltic andesites. South Sister experienced an intense period of eruptive activity from approximately 36 ka to 22 ka, during which it erupted a diverse suite of magmas ranging …


Understanding Potential Reservoir Interconnectivity Between Two Contemporaneous Volcanoes During The Onset Of Cone-Building Activity, Middle Sister And South Sister, Central Oregon, Emma Calvert Jun 2023

Understanding Potential Reservoir Interconnectivity Between Two Contemporaneous Volcanoes During The Onset Of Cone-Building Activity, Middle Sister And South Sister, Central Oregon, Emma Calvert

Geology Graduate and Undergraduate Student Scholarship

Klah Klanee (Three Points) is located in the central Cascades near Bend, Oregon. The Three Sisters Volcanic Complex (TSVC) lies at a tectonically complex intersection of the Cascade Subduction Zone, the Basin and Range Province, and the High Lava Plains. The TSVC is a compositionally diverse volcanic field consisting of four stratovolcanoes and numerous periphery cones and vents. Middle Sister and South Sister are the youngest of the stratovolcanoes and they share a largely contemporaneous and semi-alternating episodic eruptive history. These parallel histories could indicate a complex, interconnected magmatic root system within the crust below the TSVC and the surrounding …


Using Mineral Magnetism To Characterize Compositions Of Fe-Ti Oxide Phases Of The Sulphur Creek Lava Flow (Kulshan), Elika Zilis Apr 2023

Using Mineral Magnetism To Characterize Compositions Of Fe-Ti Oxide Phases Of The Sulphur Creek Lava Flow (Kulshan), Elika Zilis

WWU Honors College Senior Projects

The aim of this study is to examine variations in the composition of Fe-Ti oxide minerals in the Sulphur Creek lava flow (SE margin of Kulshan), using magnetic techniques and electron microscopy. Geochemical and petrological data from these rocks dated ~9.8 ka may be a product of two distinct magma pulses (Garvey, 2002) with two distinct compositions: andesitic basalt and basalt. The composition of cubic oxides (magnetite and ulvöspinel) is influenced by the geochemistry of the crystallizing magma and can be used to provide information about the chemical evolution of these magmas, but also to help frame future paleomagnetic studies …


Silicon And Oxygen In Earth’S Core: Applications Of Machine Learning To Metal-Silicate Equilibria And Core Formation, Ruben Keane Jan 2023

Silicon And Oxygen In Earth’S Core: Applications Of Machine Learning To Metal-Silicate Equilibria And Core Formation, Ruben Keane

WWU Honors College Senior Projects

Within Earth’s core, light elements (Si, O, C, S, N, H) are known to make up a small fraction of the total mass of the core with respect to heavy elements. The degree to which these elements exist in the cores of terrestrial planets have geophysical and geochemical implications, most notably the presence of core convection and a geodynamo, thermal conductivity within the core, and core temperature. Comparison of the composition of chondrites to Earth’s mantle composition and the Preliminary Reference Earth Model have given an estimation of about 10 % light elements in Earth’s core. The concentrations of each …


Modeling 21st Century Peak Flows In The Nooksack River Basin In Northwestern Washington State Using Dynamically-Downscaled Global Climate Model Projections, Evan A. Paul Jan 2023

Modeling 21st Century Peak Flows In The Nooksack River Basin In Northwestern Washington State Using Dynamically-Downscaled Global Climate Model Projections, Evan A. Paul

WWU Graduate School Collection

The Nooksack River in northwestern Washington State provides freshwater for agriculture, municipal, and industrial use and serves as a vital habitat for endangered salmon, a resource that is of cultural and economic importance to the Nooksack Indian Tribe and the surrounding region. As more landscape becomes exposed to rain rather than snow and heavy winter precipitation events intensify (i.e., atmospheric rivers), peak flows and sediment delivery to streams will increase due to rapid runoff, resulting in salmon habitat degradation and increased flood risk. Thus, anticipating the effect of climate change on peak flows is crucial for salmon habitat restoration efforts …


Connections Between Eruption Style And Magmatic Reservoir Evolution: Insights From Augustine Volcano, Alaska, Usa, Mahinaokalani G. Robbins Jan 2023

Connections Between Eruption Style And Magmatic Reservoir Evolution: Insights From Augustine Volcano, Alaska, Usa, Mahinaokalani G. Robbins

WWU Graduate School Collection

At a single volcano, eruptive behavior can change through time as the plumbing system evolves. Augustine Volcano, a frequently active intermediate stratovolcano in the Alaska-Aleutian arc (USA), is an ideal setting to investigate magma reservoir processes due to its frequent modern and Holocene eruption history. Its most recent 2006 CE eruption included mixed effusive and moderately explosive (VEI 3) events and has been studied in detail. Proximal fall deposits from this eruption were generally mixed fine ash to lapilli with variable thickness, but typically ~5 cm on the island (Wallace et al., 2010). The Pre-contact “Tephra M” was deposited by …


A Mixed-Methods Study Of Geoscience Identity, Race/Ethnicity, And Gender In Senior Undergraduate Geoscience Majors, Willa Rowan Jan 2023

A Mixed-Methods Study Of Geoscience Identity, Race/Ethnicity, And Gender In Senior Undergraduate Geoscience Majors, Willa Rowan

WWU Graduate School Collection

I conducted a mixed methods study of geoscience identity in undergraduate students to examine the cultural and social aspects of geoscience degree programs. White students are overrepresented in geoscience, and a priority of anti-racism efforts in the field is listening to the experiences of students who are Black, Indigenous, or people of color (BIPOC) to better inform equity and inclusion goals. Structural racism in geoscience pushes BIPOC students out of the field, and it can be better understood by studying socially constructed aspects of learning such as geoscience identity. This study is the first to measure geoscience identity with a …


Using Camera-Monitored Sediment Traps To Evaluate Sediment Availability And The Role Of Waves In Resuspending Seafloor Sediment, Bellingham Bay, Wa, Liam Horner Jan 2023

Using Camera-Monitored Sediment Traps To Evaluate Sediment Availability And The Role Of Waves In Resuspending Seafloor Sediment, Bellingham Bay, Wa, Liam Horner

WWU Graduate School Collection

Understanding nearshore sediment budgets and processes is important for evaluating coastal hazards, habitats, and contaminant fate to enable informed decisions in coastal planning and management. I aimed to evaluate the role of waves in resuspending and redistributing sediments and by proxy contaminants in the urban/estuarine Bellingham Bay, and better understand the transport and rate of fluvial sediment moving through the nearshore. I integrated analyses using camera-mounted sediment traps, seafloor grain-size data, short-lived radioisotopes, and other fluvial, physical oceanographic, and wind data. I paired cameras with sediment traps, to identify the timing and rate of sedimentation on the seafloor at hourly …


Biomarker Study Of Bellingham Bay : Identifying How Urbanization Has Affected Carbon Storage And Eelgrass, Jess Shulman Jan 2023

Biomarker Study Of Bellingham Bay : Identifying How Urbanization Has Affected Carbon Storage And Eelgrass, Jess Shulman

WWU Graduate School Collection

Understanding sediment sources and fluxes throughout coastal zones is essential to evaluate shoreline stability, ecosystem health, and the potential for carbon storage. In Bellingham Bay, WA, like many developed coastal settings, urban areas have replaced forested cover and altered sediment fluxes, yet little is known of their offshore impacts. I analyzed n-alkanes, found in plant leaf waxes preserved in marine sediments of Bellingham Bay to characterize sediment sources and reconstruct changes in the relative contributions of eelgrass beds to sedimentary organic matter since pre-industrial times using a linear mixing model. Eight 2-meter-long cores were analyzed in order to determine how …


Reconstructing Wildfire Regime During The Warm Paleocene-Eocene Climate Using Molecular Biomarkers From The Chuckanut Formation In Northwest Washington, U.S.A., Alexandra Thompson Jan 2023

Reconstructing Wildfire Regime During The Warm Paleocene-Eocene Climate Using Molecular Biomarkers From The Chuckanut Formation In Northwest Washington, U.S.A., Alexandra Thompson

WWU Graduate School Collection

Wildfires are expected to increase in frequency and severity as climate changes in the Pacific Northwest of North America. To better understand the effect of warming climate on wildfire regimes, I present the first reconstruction of past wildfire frequency and severity during the Paleocene-Eocene transition in northwest Washington state, U.S.A. The Chuckanut Formation is a late Paleocene to Eocene sedimentary unit with a robust paleobotanical record showing the existence of subtropical forests in northwest Washington during the Paleocene, transitioning to a relatively cooler Eocene, dominated by temperate mixed forests. Geochemical records of environmental change coinciding with Paleocene-Eocene climatic change in …


Using Chemical Zoning In Minerals To Understand Magmatic Processes At Augustine Volcano, Alaska, Sloane Kennedy Jan 2023

Using Chemical Zoning In Minerals To Understand Magmatic Processes At Augustine Volcano, Alaska, Sloane Kennedy

WWU Graduate School Collection

The eruption behavior of a volcano is intrinsically linked to magmatic evolution. Augustine Volcano is an active stratovolcano in the Aleutian Arc (AK, USA), showing stratigraphic evidence that eruptions before 1,800 C.E. were more explosive, producing thick pumice deposits, compared to the six eruptions observed in the last 200 years. Tephra B, an understudied ~400-year-old pumice fall unit, represents the last more explosive style eruption at Augustine - making it ideal for studying how changes in magmatic evolution can result in changes in eruption style. For this thesis, I used textural zoning patterns and chemical variations (major and trace elements) …


U-Pb Zircon Geochronology And Structure Of Regional Blueschist Units In The Easton Metamorphic Suite, Northwest Cascades, Wa, Katherine Lang Jan 2023

U-Pb Zircon Geochronology And Structure Of Regional Blueschist Units In The Easton Metamorphic Suite, Northwest Cascades, Wa, Katherine Lang

WWU Graduate School Collection

The Easton metamorphic suite of the Northwest Cascades Thrust System (NWCS) is a well-preserved subduction accretion complex in Washington State. The regional blueschist units of the Easton metamorphic suite include the Mt. Josephine semi-schist, Darrington Phyllite, and Shuksan greenschist/blueschist and all are interpreted to have accreted after the onset of Jurassic subduction beneath North America. This study uses zircon U-Pb geochronology, structure, and field observations to test the regional correlations between units in the Easton metamorphic suite and address models for the timing of subduction accretion along the North American margin in the Late Jurassic – Early Cretaceous. The results …


Investigating Kīlauea’S 2018 Offshore Lava Emplacement Through Hydroacoustic Data, Olana Costa Jan 2023

Investigating Kīlauea’S 2018 Offshore Lava Emplacement Through Hydroacoustic Data, Olana Costa

WWU Graduate School Collection

The 2018 eruption of Kīlauea Volcano produced an unprecedented volume of lava, creating 3.5 km2 of new land on Hawai`i’s Big Island (Soule et al., 2021). Lava expelled from the Ahu`aila`au vent (originally called Fissure 8) traveled ~13 km to where it entered the ocean. Over half of the lava erupted in 2018 was emplaced offshore where it produced four new submarine lava deltas (Soule et al., 2021). In response to the eruption, a network of 12 ocean-bottom seismometers (OBS) with attached hydrophones was deployed on Kīlauea’s submarine south flank. Ten of the instruments successfully recorded data from July …


Does Sediment Supply Impact The Threshold For Initial Sediment Motion In Natural, Gravel Bedded Streams?, Emily Loucks Jan 2023

Does Sediment Supply Impact The Threshold For Initial Sediment Motion In Natural, Gravel Bedded Streams?, Emily Loucks

WWU Graduate School Collection

Sediment transport in river channels control channel morphology, streamflow, and benthic ecosystems. Predicting sediment transport rates through a channel is required for sediment management for stream restoration and aquatic habitat assessment. The critical Shields stress (τ*c), is a dimensionless parameter used in sediment transport models that characterizes the river bed surface shear stress required to initiate sediment motion. The τ*c is typically assumed constant in transport models, yet compilations of field data have shown that τ*c can vary wildly, causing sediment transport models to over- or under-predict fluxes by an order of magnitude or more. Understanding …


Paleomagnetic Determination Of Vertical Axis Block Rotation Near The Doty Fault In Southwestern Washington, Charles Linneman Jan 2023

Paleomagnetic Determination Of Vertical Axis Block Rotation Near The Doty Fault In Southwestern Washington, Charles Linneman

WWU Graduate School Collection

In this paper I present the results of paleomagnetically derived vertical axis rotations (VARs) of sites in two different flows of the Columbia River Basalt (CRB) – the 16 Ma Sentinel Bluffs member of the Grande Ronde flow and the 12 Ma Pomona Member of the Packsack Lookout – near the Doty fault in southwestern Washington. In two field seasons, I collected 99 cores from 14 sites, 11 in the Grande Ronde flow and three in the Pomona member flow. Of the 227 specimens that I demagnetized, 212 had well-defined magnetic directions. Positive fold and reversal tests results confirm the …


Quantifying Channel Change Following Post-Fire Debris Flows In A Steep, Coastal Stream, Big Sur, California, Telemak Olsen Jan 2023

Quantifying Channel Change Following Post-Fire Debris Flows In A Steep, Coastal Stream, Big Sur, California, Telemak Olsen

WWU Graduate School Collection

Debris flows commonly occur following wildfire in steep landscapes, introducing large volumes of sediment to downstream fluvial systems. Fire-related sediment supply perturbations impact channel morphology, and importantly, fragile aquatic and riparian ecosystems downstream of disturbance. The Big Creek watershed drains 57 km2 of steep chaparral and coast redwood forest along California’s Central Coast. Streams in the Big Creek watershed typically exhibit step-pool/cascade morphology and serve as vital spawning habitat for anadromous Steelhead Trout (Oncorhynchus mykiss). In 2020, 97% of the Big Creek watershed burned in the Dolan Wildfire. In January 2021, an atmospheric river event triggered a series of …


Modeling The Effects Of Projected Climate Warming On Stream Temperatures In The Stillaguamish River Basin, Emily E. Smoot Jan 2023

Modeling The Effects Of Projected Climate Warming On Stream Temperatures In The Stillaguamish River Basin, Emily E. Smoot

WWU Graduate School Collection

The Stillaguamish River is a snow-and-rain mixed basin and the fifth largest river in the Puget Sound basin. Elevations in the 1700 km2 Stillaguamish River basin reach roughly 2000 m and historically a snowpack is sustained above 1000 m. Snowmelt in the basin is important for sustaining spring and summer streamflow and buffering stream temperatures. Stream temperature increases are of significant concern because of the threatened Chinook salmon (Oncorhynchus tshawytscha) population.

I reexamined projected stream temperatures in the Stillaguamish River by forcing the coupled Distributed Hydrology Soil Vegetation Model and River Basin Model with dynamically downscaled meteorological …


Magnetic Methods To Characterize The Emplacement Of The Nodule Point Intrusion (Marrowstone Island, Wa), Charlie Nuncio Oct 2022

Magnetic Methods To Characterize The Emplacement Of The Nodule Point Intrusion (Marrowstone Island, Wa), Charlie Nuncio

Geology Graduate and Undergraduate Student Scholarship

The mafic intrusion of Nodule Point, Marrowstone Island, WA has sparse scientific literature to substantiate the local geologic history around its emplacement conditions. To fill this gap, rock magnetism and paleomagnetic methods have been applied to the intrusion and the sandstone of Scow Bay host rock. Samples taken from both lithologies were subject to thermal and alternating field demagnetization to assess paleomagnetic components. The Anisotropy of Magnetic Susceptibility (AMS) of samples was measured, and the maximum axis of susceptibility, K1, was used as an analog to hypothesize emplacement conditions. The host rock: the sandstone of Scow Bay, returned magnetization characteristics …


A Field Guide To Jezero Crater, Mars, Lee Adair Oct 2022

A Field Guide To Jezero Crater, Mars, Lee Adair

WWU Honors College Senior Projects

This project aims to blend art, creative writing, and scientific inquiry to explore the possibilities of geology research on our neighboring planet, Mars. This exploratory field guide combines journals, notes, and images to inform the reader of what they can expect to see on the Martian surface.


Mastcam Multispectral Database From The Curiosity Rover’S Traverse In Gale Crater, Mars (Sols 0-2302), Melissa S. Rice May 2022

Mastcam Multispectral Database From The Curiosity Rover’S Traverse In Gale Crater, Mars (Sols 0-2302), Melissa S. Rice

Geology Faculty Publications

The Mars Science Laboratory (MSL) Curiosity rover has explored fluvio-deltaic, lacustrine, and aeolian strata as it climbed over 400 m in elevation over the first 2302 sols of its traverse. Curiosity’s Mast Camera (Mastcam) instrument is a pair of multispectral imagers covering visible to near-infrared (VNIR) wavelengths (445 nm - 1013 nm). Mastcam spectra can broadly distinguish between iron phases and oxidation states, and in combination with chemical data from other instruments, Mastcam spectra can help constrain mineralogy, depositional origin, and diagenesis. This dataset includes representative Mastcam spectra from >600 multispectral observations acquired across Curiosity’s traverse through Vera Rubin ridge …


Can Women Science?: A Climate Survey To Address Gender Inequity In Wwu’S Geology And Physics/Astronomy Departments, Raina Shaw Apr 2022

Can Women Science?: A Climate Survey To Address Gender Inequity In Wwu’S Geology And Physics/Astronomy Departments, Raina Shaw

WWU Honors College Senior Projects

This research study aims to assess and analyze gendered differences in student perceptions of the environment and climate in WWU’s Geology and Physics & Astronomy Departments. Underlying hypotheses involve the perceptions, comfort, and discrimination of women and gender minorities in male-dominated spaces. We also theorize that these gendered differences will increase with seniority and more so within physics than in geology. In addition to testing these hypotheses, we sought to collect relevant student feedback on factors that influence their perceptions of the climate & environment, to identify areas for future study and formal program assessment. From 56 respondents, this study …


Extraction And Interpretation Of Fatty Alcohols In The Chuckanut Formation, Ellis Lower Apr 2022

Extraction And Interpretation Of Fatty Alcohols In The Chuckanut Formation, Ellis Lower

WWU Honors College Senior Projects

Earth’s climate can be tracked through geologic time by studying palaeobotanical conditions, as plants are sensitive to fluctuations in climate. Plant biomarkers (molecules found in the epicuticular wax of leaves) can be preserved for millions of years in sedimentary rocks, act as molecular fossils, and provide insight into the type of vegetation cover at the time of deposition. This project focused on extracting one such class of compounds: fatty alcohols. We used fatty alcohols as biomarkers to improve palaeobotanical reconstructions of the Chuckanut Formation during the Eocene. The fatty alcohols found in samples lacking macrofossils from the Slide member of …


Google Earth Model Of The Southern Alisitos Arc Crustal Section, Baja California, Rebecca Morris, Sarah Medynski, Susan M. Debari, Cathy Busby Mar 2022

Google Earth Model Of The Southern Alisitos Arc Crustal Section, Baja California, Rebecca Morris, Sarah Medynski, Susan M. Debari, Cathy Busby

Geology Faculty Publications

The Cretaceous Alisitos Ocean Arc 3D Model version 1 (v1) is a publically accessible and interactive 3D arc crustal model, with geologic map overlays on Google Earth. The model provides a virtual field trip through the upper- to middle-crust transition in the exhumed 110 Ma southern Alisitos Arc, Baja California, Mexico. This region was chosen for the model as it exposes a structurally intact and minimally altered transition zone between heterogeneous volcanic upper crust through the underlying plutonic rocks (up to ~7 km deep). The model is organized into three paleo-volcanic centers, which include (from north to south): a northern …


To Erupt Or Not To Erupt? That Is The Question: Extremely High Levels Of Background Seismicity And Lack Of Eruptivity From 2003-2019 At Gareloi Volcano, Aleutian Islands, Alaska, Kiana Tamarie Harris Jan 2022

To Erupt Or Not To Erupt? That Is The Question: Extremely High Levels Of Background Seismicity And Lack Of Eruptivity From 2003-2019 At Gareloi Volcano, Aleutian Islands, Alaska, Kiana Tamarie Harris

WWU Graduate School Collection

Mount Gareloi, one of the westernmost volcanoes in the Aleutian arc, has not erupted since 1989, yet it continuously exhibits extremely high levels of background seismicity. Hundreds of volcanic earthquakes are recorded per day on the island since seismometer installation in 2003. I analyzed and classified seismic data collected from 2003-2019 to explore the geophysical processes causing this consistent seismicity with no subsequent eruptive activity. Analysis of waveform and corresponding spectra indicate the vast majority of Gareloi earthquakes are characterized by frequencies between 1 and 5 Hz, which are typical of long-period (LP) events, and these events are particularly dominant …


Cycles Or Repetitions: A Quantitative Analysis Of Alluvial Bed Thicknesses, Kristopher D. Phillips Jan 2022

Cycles Or Repetitions: A Quantitative Analysis Of Alluvial Bed Thicknesses, Kristopher D. Phillips

WWU Graduate School Collection

Sedimentary strata display a range of repetitive patterns from interbedded lithofacies through recurring sequence stratigraphic systems tracts. Highly structured, large-scale patterns are commonly ascribed to cyclic allogenic forcings such as eustasy and climate. In contrast, autogenic processes are typically thought to impart stochastic noise or limited small-scale structure on stratigraphy. Recent studies indicate some autogenic processes in fluvial and fluvio-deltaic systems such as the large-scale compensational deposition (i.e., the tendency for a channel to occupy and fill topographic lows in a basin), can occur on spatiotemporal scales that may overlap with some allogenic forcings. These autogenic processes could impart deterministic, …