Earth Sciences Commons^™

A New Numerical Model Of Coupled Inland Ice Sheet, Ice Stream, And Ice Shelf Flow And Its Application To The West Antarctic Ice Sheet, Christina L. Hulbe, D. R. Macayeal

Geology Faculty Publications and Presentations

We have developed a dynamic/thermodynamic finite element numerical model that couples inland ice sheet, ice stream, and ice shelf dynamics. This new model stands apart from other whole ice sheet models in its explicit treatment of ice stream flow. Additionally, the model accounts for both horizontal and vertical advection and diffusion of temperature in the flowing ice. In present day simulations of the West Antarctic Ice Sheet (WAIS), modeled ice velocity agrees well with observed ice flow. In particular, the model reproduces the pattern of speed variation across ice streams although the continuous downstream speed up of ice flow cannot …

Modeling Macrophytes Of The Columbia Slough, Oregon, Chris Berger, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

The Columbia Slough is a tidally influenced freshwater system of wetlands, channels, and lakes located within the Portland, Oregon metropolitan area at the confluence of the Willamette and Columbia Rivers. It is a eutrophic water body susceptible to algae blooms and crashes and periods of high pH which violate water quality standards. High nutrient loads from groundwater principally controls algae productivity. Past structural changes to the Columbia Slough have included filling of wetlands and lakes and the construction of levees, dikes, culverts and irrigation channels. These changes have altered the natural flow dynamics creating an environment more conducive to eutrophication. …

Hydrogeology And Paleohydrology In The Williamson River Basin, Klamath County, Oregon, Jeffrey Scott Conaway

Dissertations and Theses

Stress on the water resources of the Williamson River basin has led to their regulation to protect important habitat. Quantification of this resource is required for accurate regulation. A portion of this study is a hydrogeologic reconnaissance that suggests directions for future work. Measured discharge and deuterium isotope data from points above and below the Williamson River canyon indicate that the river receives 99% of its discharge from ground water during periods of low flow. The principle aquifer of the southern Klamath Marsh is a fractured basalt, while continental sediments that are up to 200 m thick provide high artesian …

Analytical Modeling Of Cake Filtration, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

The specific resistance model of cake filtration is based on the assumption that the average cake resistance is constant over time. This implies also that the spatially average values of porosity and pressure differential are also constant over time since specific resistance is a function of both parameters.

An analytical cake filtration model based on Tiller (1975) was derived using constitutive properties of kaolin suspensions in distilled water. Constitutive properties were determined by experiments performed using high-energy X-rays and porewater pressure probes to determine the spatial and temporal distributions of porosity and porewater pressure. Using these constitutive properties, predictions were …