The dense Corvallis array deployed in January of 2022 aided in the high-resolution study of local geology. This array was made of 177 SmartSolo 3-component 5 Hz geophones around Corvallis, with a 93 geophone profile going west towards Bald Hill for approximately 5 km at an average of 64 m...
Strong ground motions from earthquakes can result in the reduction of the shear modulus and wave propagation characteristics of soils, and can produce liquefaction and cyclic softening during shaking and for some time following the seismic event. While the ground motions produced from controlled blasting are different than those in...
Residents in South Falls City, a small town in the foothills of Oregon's Coast Range, battle intense flooding during the rainy season. Disagreements about surface water management pit neighbor against neighbor, but preliminary evidence suggests that groundwater flooding is an underlying cause. OSU researchers pair the emerging literature on groundwater...
Distributed deformation in the backarc of Cascadia is complex. Off the west coast lies the Cascadia convergent margin. East of the plate boundary, clockwise rotation of the Oregon Coast Range block with respect to stable North America influences backarc deformation, causing extensional faults in southeast Oregon, contraction folding in southeast...
In coastal and ocean engineering, understanding the ocean environment and the forces from waves, tsunamis and waterborne debris on structures and floating bodies is an important aspect of designing safe and effective infrastructure. Understanding the impact of these forces on structures becomes an important question in the design process. Answering...
The passive charge compensation (PCC) technique was introduced for switched capacitor (SC) circuit to increase the slew rate and enhance the linearity performance, as PCC techniques are used on the Delta-Sigma modulator (DSM) in ADC circuitry. The PCC technique of the project was applied to the design of a SC...
Survival of ecological systems pivot on critical moments. In the arid John Day Basin of Eastern Oregon, extensive restoration of the stream and floodplain focused on supporting salmon has been ongoing for the past 20 years, but recurring short periods of extreme temperature increase and low flows result in mortality...
Cross-laminated timber (CLT) is revolutionizing the use of wood in the construction sector of North America as a solution for walls and diaphragms in mid-rise or even high-rise timber structures on account of its environmental advantages, high strength-to-weight ratio, fire-safety performance, and propensity for prefabrication. However, considering the hygroscopic nature...
Portions of Yellowstone Lake sit on top of a vigorous but not well understood hydrothermal system situated in a region of intense geologic and environmental forcings. A heat flow study conducted over the Stevenson Island Vent Field (SIVF), a vent field at the bottom of Yellowstone Lake underlain by an...
CLT is becoming global. New countries and regions increasingly realize the potential of what can be done with CLT. As a result, new markets are forming and new companies are entering the industry. Every new region or country that opens its doors to CLT has its own challenges and opportunities....
The aim of this research is to understand and quantify the modeling differences between CSiBridge and OpenSees, and to determine sensitive model parameters. When designing bridges for the high seismic region of California, the California Department of Transportation (Caltrans) performs nonlinear time history analysis of their bridge models. For three-dimensional...
The development of cross-laminated timber (CLT) panel technology has opened up new opportunities for wood in tall buildings. Several characteristics including seismic performance and speed of construction have raised interest among designers. As CLT gains acceptance in the industry, alternative structural solutions need to be investigated to improve performance of...
Three-dimensional gravity analysis is the process of removing the predictable
components from the free-air gravity anomalies and has proven to be useful for
interpreting the subsurface structures and active processes at mid-ocean ridges. The
three-dimensional effects of the seafloor and Moho topography, assuming a constant
crustal thickness and constant crust...
End users develop more software than any other group of programmers, using software authoring devices such as e-mail filtering editors, by-demonstration macro builders, and spreadsheet environments. Despite this, there has been only a little research on finding ways to help these programmers with the dependability of the software they create....
Diking and channelizing in the Toppenish Creek basin, associated with irrigated agricultural development, has altered its natural ecosystem function and hydraulic processes. We seek to answer two research questions: if surface waters are diverted for aquifer recharge in the winter, will this water be available for ecosystem function in the...
The seismic response of deep deposits of liquefiable and cyclic-softening susceptible soils has presented the geotechnical profession with significant engineering challenges. Strong ground motions may serve to soften soils under cyclic shear, trigger liquefaction, and produce damaging displacements as a consequence. This study improves the understanding of the in-situ, nonlinear,...
Microbial communities in aquatic systems are dominant drivers of chemical transformation, including contaminants of emerging concern (CECs). This study quantified shifts in microbial communities and their relationship to shifts in chemical composition in surface waters in the Willamette Valley, Oregon. In addition to bulk chemical composition shifts, the relationship between...
The Mahakam Delta which was once among the largest mangrove forests in Indonesia, has been subjected to dramatic changes in structure and function due to massive shifts from mangrove forest to shrimp ponds and oil and gas development. To understand the impacts of mangrove loss to the greenhouse gas (GHG)...
Contiential margins on plate boundaries are complex systems with morphologies and characteristics dictated by the interplay of sediment deposition and erosion, tectonic faulting, folding, and strong ground motion generating mass wasting events. With ever increasing advances in high-resolution remote sensing techniques these systems are increasingly becoming illuminated.
A ~120 km...
Damage estimates to the built environment from tsunamis are important for disaster mitigation, including planning emergency response and recovery. This dissertation evaluates the damage states of buildings in a small urban coastal city, Seaside, Oregon, from tsunami hazards generated by a Cascadia Subduction Zone (CSZ) event. This study is separated...
The Central Oregon High Cascade Range is an anomalously mafic segment of the Cascade Arc due to ongoing intra-arc extension, which allows most magmas to traverse the crust without stalling and evolving to more evolved compositions. North Sister, a composite volcano in this arc segment, has produced a seemingly monotonous...
This dissertation explores the idea of applying machine learning technologies to help computer users find information and better organize electronic resources, by presenting the research work conducted in the following three applications: FolderPredictor, Stacking Recommendation Engines, and Integrating Learning and Reasoning.
FolderPredictor is an intelligent desktop software tool that helps...
During the last 15 years, numerous geophysical surveys and geological sampling and coring expeditions have helped to characterize the tectonic setting, subsurface stratigraphy, and gas hydrate occurrence and abundance within the region of the accretionary wedge surrounding Hydrate Ridge. Because of these investigations, Hydrate Ridge has developed as an international...
Two examples of Pacific rim plate boundary deformation are presented. In the first
part of the thesis crustal models are derived for the northwestern part of the Vizcaino
block in California using marine seismic and gravity data collected by the Mendocino
Triple Junction Seismic Experiment. A northwest-southeast trending kink in...
The purpose of this research study was to describe and improve understanding of the meaning of institutionalized sustainability and the role that a college president plays in institutionalizing sustainability on a community college campus. The following questions guided the research: (a) What does it mean to have sustainability “institutionalized” at...