Physical Sciences and Mathematics Commons^™

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

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, …

Structural History Of The Formidable-Le Conte Mountain Area, North Cascades, Wa, Nyle Weldon

WWU Graduate School Collection

A record of Permian to Tertiary polyphase deformation, metamorphism and magmatism is preserved in the Cascades River region of the North Cascades Crystalline Core, Washington. The tectonic history recorded here can be used to understand the deep crustal processes occurring within active convergent plate margins around the world. New structural and geochronologic data from this study are used to advance our understanding of terrane origin, accretion, and processes that altered and thickened the crust of the North Cascades.

The study focuses on several rock units within an accreted Permian-Jurassic island arc, the Chelan Mountains terrane, that was tectonized in Cretaceous …

Using Crystal Zoning, Thermobarometry, And Melts To Elucidate Koma Kulshan’S (Mt. Baker) Transcrustal Magma Storage System, Northern Cascade Arc, Brendan Garvey

WWU Graduate School Collection

Koma Kulshan (Mt. Baker) is classified as a high-threat volcano due to its past eruptive history and its proximity to populations, yet its eruptive products are understudied. Combining mineral chemistry from complexly zoned crystals with thermobarometry and thermodynamic modeling (MELTS) is a powerful way to provide constraints on magmatic processes beneath an active volcano. Up to four populations each of pyroxene, plagioclase, and olivine occur as phenocrysts and crystal clusters in the youngest (9.8 ka) lava flow at Koma Kulshan and represent four co-crystallizing assemblages derived from distinct magmas. These co-crystallizing assemblages are defined by petrologic observations and mineral chemistry …

Reconstructing Deglacial And Holocene Climatic And Environmental Change In The Snowy Mountains Of Southeast Australia, Aidan Warner Burdick

WWU Graduate School Collection

Multi-proxy, long-term records of deglacial and Holocene climatic and environmental change in southeast Australia are rare, leaving the region a gap in local and large-scale synoptic climate reconstructions. The Snowy Mountains include the highest and coldest regions of mainland Australia and were the only part of the mainland that was glaciated during the late Pleistocene. Lakes formed by the glaciers have provided continuous sediment traps since glacial retreat following the Last Glacial Maximum. In this report, I reconstruct the maximum ice extents of glaciers during the last glacial period and estimate their equilibrium line altitudes, revising the work of Barrows …

Forearc Erosion In Response To Megathrust Plate Coupling Along The Wairarapa Coastline, New Zealand, Chantel E. Jensen

WWU Graduate School Collection

How the subduction zone earthquake cycle contributes to uplift, erosion, and permanent deformation of the overlying forearc remains largely unknown. The Hikurangi subduction zone (HSZ), along the east coast of the North Island of New Zealand, provides a unique location to examine the effects of subduction coupling on forearc deformation over multiple millennia. There, the Wairarapa coastline runs parallel to the HSZ and spans a transitional boundary between locked and freely slipping portions of the plate interface. Using digital topographic analysis and catchment-averaged erosion rates from ¹⁰Be in fluvial sands, I examined the geomorphology of the HSZ forearc to …

Testing Potential Triggering Mechanisms Of Long-Runout Catastrophic Rock Avalanches In The Nooksack River Basin, Whatcom County, Washington, Eric R. Brown

WWU Graduate School Collection

The Nooksack basin contains five large Holocene long-runout rock avalanche deposits. Similarities and spatial proximity of the deposits suggest that they may share a common triggering mechanism. Two of the deposits, Van Zandt Landslide Complex (VZLC) and Church Mountain Sturzstrom (CMS) have published ages that overlap with prehistoric earthquakes, suggesting seismicity may be the cause. To further test this idea, I mapped and dated the remaining three deposits, Racehorse Creek (RHC), Middle Fork (MFN), and Maple Falls (MF). To establish ages for the slides, I combined radiocarbon dating of organics in sediment cores from bogs in the debris fields and …

Spectral Variability In Naturally Weathered Rock Surfaces And Implications For Mars, Sabrina Curtis

WWU Graduate School Collection

Rock weathering products are important clues for understanding past environmental conditions on Mars. They can be identified using reflectance spectroscopy because the formation of new minerals and textures on a rock surface will change its spectral signature. Previous studies demonstrate that the spectral signature of coated rock surfaces can vary with viewing geometry (the angle between incident and emitted light); however, these photometric effects have not been extensively characterized for naturally weathered rocks. My goal in this study is to quantify how both weathering and viewing geometry affect visible to near-infrared (VNIR) reflectance spectra of a subset of naturally weathered …

Eruption Evolution Of West Mata Volcano, Ne Lau Basin Using Hydroacoustic And Video Data, Mikkel Shanice Louis

WWU Graduate School Collection

West Mata Volcano located in the NE Lau Basin is the site of the deepest observed submarine volcanic eruption, 1,200 meters below sea level. In May 2009, a research cruise collected video data of two eruptive vents showcasing different eruption styles. During the same research cruise, a Bprobe^TM portable hydrophone was deployed at the summit of West Mata and collected data that coincides with video recorded at the vents during ROV dives. These data sets were correlated to better understand the spectral signatures associated with the two eruptive vents. Both vents were near the summit, about 50 meters apart, …

Structural History Of The Bald Mountain Mining District, Nevada, Usa, David Paul Ryan

WWU Graduate School Collection

The Bald Mountain Mining district, like much of central Nevada, has experienced a complex deformation history. The mining district is considered here as a southern extension of the well-studied Carlin trend of gold deposits to the north. In order to gain a better understanding of how the Bald Mountain Mining District structural style relates to other structural models developed to the north in the Carlin trend, I completed a mapping and structural domain analysis in the district, with a focus on the North Mooney basin area where a high spatial concentration of Carlin-type gold deposits occur. The identification of structural …

Modeling 21st Century Peak Streamflows In The Stillaguamish Watershed Using Dynamically Downscaled General Circulation Model Projections, James Marcell Robinson

WWU Graduate School Collection

Climate change is projected to increase river flooding in the Puget Sound region of Washington State by reducing snowpack and yielding more intense storm events. Pairing meteorological forcings from general circulation models (GCMs) with a physically based hydrologic model is a robust method of assessing watershed response to projected climate. Before GCM forcings can be applied to regional hydrologic models, some form of downscaling or regionalization is required. Dynamical downscaling is a means of incorporating mesoscale atmospheric processes within GCM-informed boundary conditions. Here I apply climate projections, dynamically downscaled using the Weather Research and Forecasting model (WRF), to the Stillaguamish …

A Mastcam Multispectral Investigation Of Rock Variability In Gale Crater, Mars: Implications For Alteration In The Clay-Sulfate Transition Of Mount Sharp, Alivia Eng

WWU Graduate School Collection

The Mars Science Laboratory Curiosity rover has explored over 650 m of strata since landing in 2012. After leaving Vera Rubin Ridge (VRR), the rover traversed though the phyllosilicate-rich region, Glen Torridon, and the Mg-sulfate-bearing strata that lies above it, with excursions onto the Greenheugh Pediment and Amapari Marker Band. These unique stratigraphic units were investigated using Curiosity's instrument suite which includes the Mast Camera (Mastcam) pair of multispectral imagers. Mastcam’s narrowband filters are sensitive to iron-bearing phases and some hydrated minerals. We used Mastcam spectra, in combination with chemical data from Curiosity’s CheMin, APXS and ChemCam instruments, to assess …

Glacier Peak And The Chocolate Factory: Recurring Debris Flows From The Eastern Flank Of Glacier Peak Stratovolcano, North Cascades, Washington State, Usa, Edward M. Fordham

WWU Graduate School Collection

Alpine mass wasting events can have wide ranging impacts that extend past their headwater origins reaching down to lowland population centers. The Suiattle River, which drains the eastern flank of Glacier Peak in the North Cascades of Washington State, is a dominant contributor of suspended sediment in the region. Normalized for drainage area, the Suiattle River supplies more suspended sediment than nearly any other river in the region and more than twice as much as the White Chuck River, which drains the western flank of the volcano. Despite its known importance to the regional sediment budget, the specific geomorphic drivers …