Physical Sciences and Mathematics Commons^™

Predicting Landscape Effects Of Mississippi River Diversions On Soil Organic Carbon Sequestration, Hongqing Wang, Gregory D. Steyer, Brady R. (Brady Randall) Couvillion, Holly Beck, John M. Rybczyk, Victor H. Rivera-Monroy, Ken W. Krauss, Jenneke M. (Jenneke Maria) Visser

Environmental Sciences Faculty and Staff Publications

Large Mississippi River (MR) diversions (peak water flow >1416 m³/s and sediment loads >165 kg/s) have been proposed as part of a suite of coastal restoration projects and are expected to rehabilitate and rebuild wetlands to alleviate the significant historic wetland loss in coastal Louisiana. These coastal wetlands are undergoing increasing eustatic sea-level rise, land subsidence, climate change, and anthropogenic disturbances. However, the effect of MR diversions on wetland soil organic carbon (SOC)

sequestration in receiving basins remains unknown. The rate of SOC sequestration or carbon burial in wetlands is one of the variables used to assess the …

Western Spruce Budworm And Wildfire: Is There A Connection?, Daniel G. Gavin, Aquila Flower, Greg M. Cohn, Russell A. Parsons, Emily K. Heyerdahl

Environmental Sciences Faculty and Staff Publications

In the interior Pacific Northwest, extensive defoliation of mixed conifer forests during outbreaks of western spruce budworm (WSB) may leave the visual impression of a tinderbox with trees primed to burst into flame. But is this the case?

We addressed this question with funding from the USDA/U.S. Department of the Interior Joint Fire Science Program (project 09– 1–06–5). Here we summarize our three recent publications exploring the potential relationship between WSB outbreaks and fire. We used a multimethod approach to explore potential disturbance interactions that might cause one disturbance to change the occurrence or severity of the other. We used …

Occam's Razor Vol. 7 - Full (2017)

Occam's Razor

No abstract provided.

Rainbow Turán Problems For Paths And Forests Of Stars, Daniel Johnston, Cory Palmer, Amites Sarkar

Mathematics Faculty Publications

For a fixed graph F, we would like to determine the maximum number of edges in a properly edge-colored graph on n vertices which does not contain a rainbow copy of F, that is, a copy of F all of whose edges receive a different color. This maximum, denoted by ex^∗ (n, F), is the rainbow Turán number of F, and its systematic study was initiated by Keevash, Mubayi, Sudakov and Verstraëte [Combinatorics, Probability and Computing 16 (2007)]. We determine ex^∗ (n, F) exactly when F is a forest of stars, and …

Weierstrass Points On X 0+(P) And Supersingular J-Invariants, Stephanie Treneer

Mathematics Faculty Publications

We study the arithmetic properties of Weierstrass points on the modular curves X₀⁺(p) for primes p. In particular, we obtain a relationship between the Weierstrass points on X₀⁺(p) and the j-invariants of supersingular elliptic curves in characteristic p.

The Planet, 2017, Winter, Jesse Nichols, Huxley College Of The Environment, Western Washington University

The Planet

No abstract provided.

Phillipsite And Al-Tobermorite Mineral Cements Produced Through Low-Temperature Water-Rock Reactions In Roman Marine Concrete, Sean R. Mulcahy, Marie D. Jackson, Heng Chen, Yao Li, Piergiulio Cappelletti, Hans-Rudolf Wenk

Geology Faculty Publications

Pozzolanic reaction of volcanic ash with hydrated lime is thought to dominate the cementing fabric and durability of 2000-year-old Roman harbor concrete. Pliny the Elder, however, in first century CE emphasized rock-like cementitious processes involving volcanic ash (pulvis) “that as soon as it comes into contact with the waves of the sea and is submerged becomes a single stone mass (fierem unum lapidem), impregnable to the waves and every day stronger” (Naturalis Historia 35.166). Pozzolanic crystallization of Al-tobermorite, a rare, hydrothermal, calcium-silicate-hydrate mineral with cation exchange capabilities, has been previously recognized in relict lime clasts of the concrete. Synchrotron-based X-ray …

A Pulsed-Air Model Of Blue Whale B Call Vocalizations, R. P. Dziak, J. H. Haxel, T-K. Lau, S. Heimlich, Jacqueline Caplan-Auerbach, D. K. Mellinger, H. Matsumoto, B. Mate

Geology Faculty Publications

Blue whale sound production has been thought to occur by Helmholtz resonance via air flowing from the lungs into the upper respiratory spaces. This implies that the frequency of blue whale vocalizations might be directly proportional to the size of their sound-producing organs. Here we present a sound production mechanism where the fundamental and overtone frequencies of blue whale B calls can be well modeled using a series of short-duration (<1 >s) wavelets. We propose that the likely source of these wavelets are pneumatic pulses caused by opening and closing of respiratory valves during air recirculation between the lungs and …

Population Characteristics And Habitat Use By The Recently Introduced Asiatic Clam (Corbicula Fluminea) In Lake Whatcom, Washington, Jason A. (Jason Alexander) Buehler

WWU Graduate School Collection

The Asiatic Clam (Corbicula fluminea) was found in Lake Whatcom in 2011. This exotic clam is common throughout North America and is spread between watersheds by infested boats, fishing activities, as well as passively by waterfowl. Corbicula fluminea is a well documented invasive species that survives in many environments and exhibits an rselected life history which can lead to potentially rapid population growth via a clonal reproductive ability typical among invasive bivalves and members of the family Corbiculidae. There are more reproductive strategies in Corbiculidae than any other freshwater bivalve. This rapid growth of a single organism and its associated …

Seismicity And Velocity Structure Of Offshore Hawai`I, Including Lo`Ihi Submarine Volcano, Dara K. Merz

WWU Graduate School Collection

This study presents the earthquake data collected from a nine month deployment (September 2010 - June 2011) of a temporary ocean bottom seismometer (OBS) network fully surrounding Lo‘ihi submarine volcano, Hawai‘i. This allowed us to widen the aperture of earthquake detection around the Big Island, lower the magnitude detection threshold, and better constrain the hypocentral depths of offshore seismicity that occurs between the OBS network and the Hawaiian Volcano Observatory (HVO) land based network. Although this deployment occurred during a time of volcanic quiescence for Lo‘ihi, it establishes an important basis for background seismicity of the volcano. 463 earthquakes were …

Ongoing Exhumation And Recent Exposure Of Sedimentary Outcrops On Mars, Joshua M. Williams

WWU Graduate School Collection

Determining the habitability of ancient environments on Mars and their biosignature preservation potential is a primary goal of all recent Mars exploration missions. Because cosmogenic radiation destroys organic biosignatures at the Martian surface, freshly-exposed outcrops that have been previously protected by overburden provide potential sites where organic biosignatures could be observed. Scarp retreat is one common mechanism for exposing fresh outcrop surfaces. The absence of liquid water on Mars leaves aeolian processes to be the dominant eroding agent, and aeolian erosion drives scarp retreat by undercutting erosion-resistant cap rock that fails and breaks off from outcrops. This continual action creates …

A Climactic Unimak Island Caldera-Forming Eruption, Aleutian Arc, Alaska: Magma Storage And Pre-Eruption P-T-Fo2-H2o Conditions Of The Rhyodacite Magma, Olivia E. (Olivia ElišKa) Anderson

WWU Graduate School Collection

Understanding the mingling interactions between felsic and mafic end-member magmas is essential in understanding the physical processes occurring in bimodal eruptions. The Fisher caldera-forming eruption (CFE), which co-erupted rhyodacite (~69 wt.% SiO₂) and basaltic andesite (~53 wt.% SiO₂) ~9400 yBP, was studied to better understand the scenarios under which bimodal CFEs erupt. The shallow rhyodacite had a pre-eruptive temperature of 877 – 908°C and the basaltic andesite had a pre-eruptive temperature of 1065 – 1147°C. Preeruptive water contents of ~4±1.5 wt.% H2O for the rhyodacite and ~0 – 2.5 wt.% H2O for the basaltic andesite suggest …

An Investigation Of Acid Rock Drainage In Glacial Streams Through Multivariate Exploratory Analysis And The Biotic Ligand Model In The Cordillera Blanca, Peru., Edward W. Bain

WWU Graduate School Collection

Water chemistry in the Cordillera Blanca, Peru, where glaciers provide crucial freshwater to the arid Andes Mountains, was characterized during the dry season (June-August), 2014. Metal concentrations, anion concentrations, and physical and chemical parameters were assessed at 94 sample sites in seven river valleys. Nonparametric multivariate exploratory statistics were used to compare sample sites.

Compared to other river valleys, high metal concentrations were evident in the Quilcayhuanca valley. Water chemistry and visual signs indicated that acid rock drainage (ARD) is occurring in the Cordillera Blanca, likely due to glacial recession. Hierarchical clustering analysis was performed on the results of a …

Simulation Modeling Of Population Expansion For Introduced Mountain Goats In The Olympic Mountains Of Washington State, Melissa M. Oscarson

WWU Graduate School Collection

Mountain goats (Oreamnos americanus) are not native to the Olympic Peninsula as they are to other regions of Washington State. A total of eleven or twelve animals were translocated from Alaska and British Columbia between 1925 and 1929 then released in the foothills of Mount Storm King. By 1970 these founding goats had colonized the entire Olympic range and concerns about the management of this introduced species developed as damage to alpine soil and vegetation was noted. An aerial census of the Olympic range conducted in July 1983 estimated the mountain goat population at 1,175 (95% CI 840 – 1510). …

Gender Stereotype And Spatial Reasoning: The Milankovitch Cycles, Kristina Gustovich

WWU Graduate School Collection

Stereotype threat, a phenomenon in which learners feel at risk of confirming negative stereotypes about their abilities, is often associated with spatial reasoning abilities in geoscience and has a disproportionately negative effect on women. This study examines how students’ growth or fixed mindsets mediate or amplify the effects of stereotype threat regarding self-perception of their spatial skills and learning how Earth’s cyclical orbital geometry influences its climate.

Undergraduate, introductory-level Geology students at Western Washington University were given a Pre-Test and Post-Test, a spatial reasoning test, and an assessment of their spatial reasoning abilities. Of the 154 participants, 41 had a …

Holocene Fault Reactivation And Landscape Evolution In The Eastern Cascades, Wa, Benjamin M. Carlson

WWU Graduate School Collection

Significant uncertainty remains in how and where modest, distributed shortening is accommodated throughout the eastern Cascade Range in Washington State. Using lidar imagery, I identified a ~5 km long lineament in Swakane Canyon near Wenatchee, roughly coincident with a strand of the Entiat fault. Topographic profiles show the lineament is formed by a southwest-side-up break in slope with between 2 and 42 m of vertical separation of the ground surface. Trenching reveals deformed saprolite and colluvium consistent with southwest-side-up folding caused by blind reverse faulting at depth. Radiocarbon and luminescence dating combined with stratigraphic constraints suggest up to three Holocene …

Changes In Water Chemistry And Biological Communities Associated With Metal Mining In Streams In The North Cascades, Brooke G. Bannerman

WWU Graduate School Collection

Hard rock and placer mining have been occurring throughout the mountains in the northern portion of Washington State since the late-1800s. As a result, aquatic ecosystems in this region are susceptible to the physical, chemical and biological changes that result from mining activities. These alterations, which include changes in water chemistry, habitat modifications, and reduction or contamination of food sources, can adversely impact aquatic communities of periphyton, benthic macroinvertebrates and fish. To evaluate changes in water chemistry and biological communities in two regions with extensive mining histories, the Ruby Creek watershed and Upper Skagit River watershed, I analyzed metals in …

Mothers' Roots Curriculum Project, Sonya Gobert

WWU Graduate School Collection

Since time immemorial, Indigenous mothers have taught their children how to survive in Indigenous way of being. When we remind our daughters of the strength, and the generations of resiliency and self-love before them, is when we will see real change. The truth is, when we teach our children their identity, we are giving them the tools to restore and rebuild their roots. These children are then the seeds which will be planted with the promise to grow in the awareness of true sovereignty, nationhood, and self-empowerment steeped in Indigenous truth which will ultimately trickle down in their own parenting …

A Theoretical And Experimental Study Into The Kinetics Of Solution Phase Thin Film Deposition, Cyrus Schaaf

WWU Graduate School Collection

The performance of electronic and optoelectronic devices based on solution-processed organic semiconductor layers is strongly influenced by their mesoscale polycrystalline structure, including domain size and spatial distributions. In solution-processed films prepared by spin casting, solvent-based printing, and related methods, morphology is governed by a combination of interrelated thermodynamic and kinetic factors. Classical models of crystal formation in bulk solution or on bare surfaces in vacuum-deposited films fail to adequately capture these effects; the current theoretical understanding of crystallization in solution-deposited films is generally unable to provide much insight, let alone predictive design guidance for tailoring films with specific structural characteristics …

Structural Evolution Of The San Juan Thrust System, Orcas And Shaw Islands, Wa, Kevin Quillan

WWU Graduate School Collection

The San Juan Thrust System represents the western elements of the Cascades orogen and preserves evidence for Cretaceous Cordilleran margin tectonics. The kinematics of deformation phases and their temporal relationship to accretionary wedge high-pressure low-temperature metamorphism remains uncertain. The structural and metamorphic evolution of the San Juan Thrust System was studied on Orcas and Shaw Islands in Western Washington. Detailed field mapping indicates that a widespread S1 flattening fabric (formed during D1) is subparallel to and cut by an S2 fabric found within brittle-ductile shear zones that bound the terranes (formed during D2). Post-cleavage brittle structures (formed during D3) offset …

Probing The Catalytic Properties Of Ni-Based Bimetallic Phosphides For Deep Hydrodesulfurization, Peter J. Topalian

WWU Graduate School Collection

Global demand for transportation fuels continues to rise while environmental standards for sulfur impurities in fuels have become more stringent. Upgrading crude oil feed stocks via deep hydrodesulfurization (HDS) is necessary to meet the ultra-low sulfur standards for transportation fuels. Transition metal phosphides (e.g. Ni₂P, Ru₂P) represents a new class of hydrotreating catalysts that show promise for improved HDS properties relative to conventional molybdenum sulfide based catalysts. Incorporating a second metal into Ni₂P can influence the surface properties and be used to tailor the catalytic properties (activity, selectivity) for improved hydrotreating performance. Bimetallic phosphides …

Modeling, Design And Fabrication Of Biocompatible Silk-Based Electronics And Actuators, Nicholas Ostrovsky-Snider

WWU Graduate School Collection

Biocompatible actuators are widely desired for a variety of biomedical devices such as micromanipulators, steerable catheters and artificial muscles but current devices have shortcomings in the range of motion they can achieve. Biocompatible electrodes made from conducting polymers (CPs) have been successfully created but achieving the spatial patterning of these polymers needed for electronic devices like strain gauges, stimulation electrodes and micro circuitry has been difficult. Previous work has relied on complex chemical incorporation of CPs into photoresists or electropolymerization onto vapor-deposited metal substrates. A simple method to produce metal-free flexible electronics would be highly desirable for biomedical electronics. This …

A Computational Investigation Of Bodipy Excited State Properties And Photosensitization Of Molecular Oxygen, Keenan Komoto

WWU Graduate School Collection

Cancer has long been a significant problem that has affected our world’s population for years and continues to this day. With the number of cases expected to increase annually there is a societal pressure to find effective treatment methods for eliminating cancer. Current forms of cancer treatment tend to cause detrimental effects to the human body and are usually quite expensive and long lasting, some costing upwards of $30,000 over an 8 week period. A more recently established form of cancer treatment known as photodynamic therapy is an effective treatment option for ridding cancers that lie on or just below …

Interpreting The Dynamics Of Submarine Landslides Through Hydroacoustic Modeling, West Mata Volcano, Ne Lau Basin, Jonathan G. Drobiarz

WWU Graduate School Collection

Landslides are an integral process in the development of submarine volcanoes, but these events are rarely recorded and observed. Therefore, understanding how the morphology of volcanoes evolve requires information on landslides. Hydroacoustic signals were analyzed for the purposes of characterizing frequent landslides on West Mata volcano during a 5-month eruptive period. Over 200 landslide signals have been compared in conjunction with hydroacoustic modeling to better understand the dynamics that control them. We used interference patterns produced by multipath rays to identify and model these slope failures. Landslides were most clearly captured on the north and west stations, suggesting a source …

Effectiveness Of Salmon Carcass Analogs As A Form Of Nutrient Enhancement For Juvenile Coho Salmon (Oncorhynchus Kisutch) In Three Lower Columbia Watersheds, Matthew T. Sturza

WWU Graduate School Collection

Adult Pacific salmon exhibit a form of parental care after spawning and perishing by depositing a subsidy of marine derived nutrients (MDN) that may be incorporated into the stream food web and feed juvenile salmon. Adult salmon populations have significantly declined since the late 19th century, thereby reducing the amount of MDN within Pacific Northwest Streams. This loss in nutrients within stream food webs may be limiting the growth and survival of juvenile salmon and therefore reducing the population sizes of adult salmon. One strategy to mitigate for nutrient deficiencies within a stream is the use of salmon carcass analogs …

Testing The Time Dependence Of Slip On The Western Klamath Lake Fault Zone, Oregon, Gunnar Speth

WWU Graduate School Collection

New geomorphic mapping and cosmogenic 3He geochronology on the Western Klamath Lake fault zone in southern Oregon reveals moderate, but resolvable changes in the rate of normal-fault slip rates over the past ~170 kyr. We focus on a sequence of glacial and post-glacial surfaces that record progressive offset by the fault zone over multiple time intervals. Thirty-nine new cosmogenic ³He surface exposure dates and a cosmogenic nuclide depth profile establish the first late-Pleistocene glacial chronology in the Cascade Range of Oregon and constrains the timing of the last two major glacial advances in the region at 17.6 ± 2.1 …

Plant Community And Nutrient Development Within Four Estuary Restoration Sites In Kitsap County, Washington, Shannon M. (Shannon Marie) Call

WWU Graduate School Collection

Coastal wetland ecosystems are some of the most productive ecosystems on the planet and link freshwater and marine environments. Coastal wetlands provide invaluable ecosystem services such as carbon sequestration, storm abatement, biogeochemical cycling, and water filtration. However, estuaries affected by physical barriers, such as culverts, experience reduced hydrological inputs and reduced connectivity above and below the site of impact. Loss of connectivity results in loss of ecosystem function such as carbon and nitrogen cycling. We investigated soil nutrients and vegetation composition of estuarine communities in four estuary restoration locations in Kitsap County, Washington and the following questions were addressed: 1) …

Do Conspecific Soil Microorganisms Inhibit Potentilla Recta?, Faythe Duran

WWU Graduate School Collection

In the U.S., Potentilla recta is an invasive, exotic forb. Previous research suggests that the soil microbes of native congeners (relatives within the same genus as P. recta) may inhibit P. recta, presumably because phylogenetically similar species may culture and be susceptible to similar pathogens. Our study aimed to answer three questions: (1) how do the fungal communities within the roots of P. recta compare to the fungal communities within the roots of neighboring congeners Potentilla gracilis and Drymocallis glandulosa (hereinafter referred to as the congeners) and native forbs, (2) what are the effects of the whole microbial …

Intermolecular Interactions That Lead To The Activation And Inhibition Of Ribosome-Dependent Gtpases, Amanda J. Weis

WWU Graduate School Collection

Ribosomes are the macromolecular machines responsible for protein synthesis across all domains of life. Translation of genetic information into a polypeptide by ribosomes is facilitated by a multitude of proteins called translation factors, many of which belong to the guanosine 5’ triphosphate hydrolase (GTPase) superfamily that utilize the hydrolysis of GTP to exert their function. Many naturally occurring antibiotics inhibit protein biosynthesis by targeting the bacterial ribosome or associated translation factors and with increasing antibiotic resistance due to bacterial evolution, the importance of studying ribosome-translation factor interactions is amplified. Determination of high-resolution structures of the ribosome has significantly bolstered our …

Building Arc Crust – Plutonic To Volcanic Connections In An Extensional Island Arc, The Alisitos Arc Crustal Section (Southern Rosario Segment), Baja California, Rebecca A. (Rebecca Anne) Morris

WWU Graduate School Collection

The southern volcano-bounded basin of the Rosario segment of the Cretaceous Alisitos oceanic arc provides outstanding 3-D exposures of the upper 7 km of an extensional arc, where crustal generation processes are recorded in the upper crustal volcanic rocks and underlying plutonic rocks. These exceptional exposures allow for the study of the physical and chemical links between the rock units, and helps constrain the differentiation processes active during the growth and evolution of the arc.

Upper crustal volcanic rocks comprise a 3-5 km thick volcanic-volcaniclastic stratigraphy with shallow sill and dike intrusions. Coarse-grained plutonic rocks intrude these units over a …