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,...
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...
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...
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...
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...
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 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...
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...