Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 19 of 19

Full-Text Articles in Physical Sciences and Mathematics

Geothermometry Of Two Cascade Geothermal Systems, Donnel Alexander Malkemus Dec 2016

Geothermometry Of Two Cascade Geothermal Systems, Donnel Alexander Malkemus

Dissertations and Theses

For this thesis I applied classical and multi-component geothermometry techniques to new water chemistry data from Breitenbush Hot Springs, Oregon and the Wind River Valley, Washington. A total of 20 well, spring, and stream samples from Breitenbush Hot Springs and 4 spring samples from the Wind River Valley were collected and analyzed for major, minor, and select trace anions and cations, as well as stable oxygen and hydrogen isotopes. I used two computer programs, GeoT and RTEst, to conduct multi-component geothermometry reservoir condition estimation on each water sample. Water chemistry data from Breitenbush Hot Springs indicates a range of thermal, …


Sedimentologic Changes In The Deposits Of An Evolving Lahar-Flood In 2006, Hood River Basin, Mount Hood, Oregon, Matthew Ray Poole Dec 2016

Sedimentologic Changes In The Deposits Of An Evolving Lahar-Flood In 2006, Hood River Basin, Mount Hood, Oregon, Matthew Ray Poole

Dissertations and Theses

Over a span of six days from November 2-7, 2006 approximately 43 cm of precipitation fell over the Hood River Basin in Oregon. A lahar was initiated on the Eliot Branch of the Middle Fork Hood River by two or more landslides that occurred on the lateral moraines of the Eliot Glacier on the early part of November 7th, 2006. The Eliot Branch lahar was embedded within the larger regional flood that was occurring in the Hood River Basin and traveled a total of 48 km from the initiation points on the north flank of Mount Hood to the Hood …


Investigation Of Jet Dynamics In Cross-Flow: Quantifying Volcanic Plume Behavior, Graham Freedland Nov 2016

Investigation Of Jet Dynamics In Cross-Flow: Quantifying Volcanic Plume Behavior, Graham Freedland

Dissertations and Theses

Volcanic eruption columns inject high concentrations of ash into the atmosphere. Some of this ash is carried downwind forming ash clouds in the atmosphere that are hazardous for private and commercial aviation. Current models rely on inputs such as plume height, duration, eruption rate, and meteorological wind fields. Eruption rate is estimated from plume height using relations that depend on the rate of air entrainment into the plume, which is not well quantified. A wind tunnel experiment has been designed to investigate these models by injecting a vertical air jet into a cross-flow. The ratio of the cross-flow and jet …


From Drought Monitoring To Forecasting: A Combined Dynamical-Statistical Modeling Framework, Hongxiang Yan Nov 2016

From Drought Monitoring To Forecasting: A Combined Dynamical-Statistical Modeling Framework, Hongxiang Yan

Dissertations and Theses

Drought is the most costly hazard among all natural disasters. Despite the significant improvements in drought modeling over the last decade, accurate provisions of drought conditions in a timely manner is still one of the major research challenges. In order to improve the current drought monitoring and forecasting skills, this study presents a hybrid system with a combination of remotely sensed data assimilation based on particle filtering and a probabilistic drought forecasting model. Besides the proposed drought monitoring system through land data assimilation, another novel aspect of this dissertation is to seek the use of data assimilation to quantify land …


Hydrogeochemical Evaluation Of The Uinta Formation And Green River Formation, Piceance Creek Basin, Northwestern Colorado, Usa, Megan E. Masterson Nov 2016

Hydrogeochemical Evaluation Of The Uinta Formation And Green River Formation, Piceance Creek Basin, Northwestern Colorado, Usa, Megan E. Masterson

Dissertations and Theses

The Piceance Creek Basin in northwestern Colorado contains extensive oil shale deposits that produce natural gas and which could potentially yield ~1.5 trillion barrels of shale oil. However, much of the oil shale lies at depths too great for traditional mining practices and various innovative approaches for in situ conversion of kerogen to oil have been proposed. A firm understanding of the existing hydrogeochemistry is needed as resulting mineralogical changes or rock-fluid reactions may affect rock porosity and permeability. Using an existing database complied by the USGS, the water chemistry of 267 surface and groundwater samples in the Piceance Creek …


Modeling Of Historic Columbia River Flood Impacts Based On Delft 3d Simulations, Lumas Terence Helaire Sep 2016

Modeling Of Historic Columbia River Flood Impacts Based On Delft 3d Simulations, Lumas Terence Helaire

Dissertations and Theses

Natural and anthropogenic processes over the past 150 years have altered the bathymetry of the Lower Columbia River (LCR) and have changed the long wave propagation of tides and floods. Possible causes for the increase in tidal amplitudes (+7% in tidal range in Astoria) are decreases in river discharge, lengthening of the river channel due to the construction of jetties at the mouth, dredging and deepening of the shipping channel, and reduction of the tidal prism due to the filling and diking of tidal wetlands. In this study, changes in the characteristics of long waves are elucidated by developing two …


Silicic Volcanism At The Northern And Western Extent Of The Columbia River Basalt Rhyolite Flare-Up: Rhyolites Of Buchanan Volcanic Complex And Dooley Mountain Volcanic Complex, Oregon, Adam M. Large Aug 2016

Silicic Volcanism At The Northern And Western Extent Of The Columbia River Basalt Rhyolite Flare-Up: Rhyolites Of Buchanan Volcanic Complex And Dooley Mountain Volcanic Complex, Oregon, Adam M. Large

Dissertations and Theses

Two mid-Miocene (16.5-15 Ma) rhyolite volcanic centers in eastern Oregon, the Buchanan rhyolite complex and Dooley Mountain rhyolite complex, were investigated to characterize eruptive units through field and laboratory analysis. Results of petrographic and geochemical analysis add to field observations to differentiate and discriminate the eruptive units. Additionally, new geochemical data are used to correlate stratigraphically younger and older basalt and ash-flow tuff units with regional eruptive units to constrain the eruptive periods with modern Ar-Ar age dates.

Previous work at the Buchanan rhyolite complex was limited to regional mapping (Piper et al., 1939; Greene et al., 1972) and brief …


Groundwater-Surface Water Interactions Near Mosier, Oregon, Cullen Brandon Jones Aug 2016

Groundwater-Surface Water Interactions Near Mosier, Oregon, Cullen Brandon Jones

Dissertations and Theses

The town of Mosier, Oregon, is located near the east, dry end of the Columbia River Gorge, and the local area is known for cherry orchards that rely heavily on groundwater for irrigation. The CRBG groundwater system in Mosier has experienced groundwater declines of up to 60 meters due to over-pumping and or commingling. Declining groundwater levels have led to concerns over the sustainability of the resource, as it is the principle water source for irrigation and domestic use. Despite numerous previous studies of groundwater flow in CRBG aquifers here and elsewhere in the Columbia River basin, an aspect that …


The Terroir Of Pinot Noir Wine In The Willamette Valley, Oregon : A Broad Analysis Of Vineyard Soils, Grape Juice And Wine Chemistry, Kathryn Nora Barnard Jun 2016

The Terroir Of Pinot Noir Wine In The Willamette Valley, Oregon : A Broad Analysis Of Vineyard Soils, Grape Juice And Wine Chemistry, Kathryn Nora Barnard

Dissertations and Theses

Terroir is determined by a combination of factors in the vineyard including the grape varietal, geology and soil, soil hydrology, physiography, and climate. Although most studies have examined regional differences in wine flavors and associated provenance of wine based on chemistry, few have examined the chemistry of the soil and the ability to trace that chemistry to grape juice and, finally, to the wine. This dissertation examines what soil physical and chemical differences specific to this region might influence grape juice chemistry and wine chemistry.

Wine-grapes in the Willamette Valley, Oregon, are grown on three major soil parent materials: volcanic, …


Factors Driving The Concentration Of Ephemeral Flow, Gretchen Anne Guyer May 2016

Factors Driving The Concentration Of Ephemeral Flow, Gretchen Anne Guyer

Dissertations and Theses

In spite of decades of related research, stream channel initiation is still not well understood. Current theories of channel initiation are grounded in research conducted by Montgomery and Dietrich, largely in the transport limited, temperate, humid climate of the Pacific Northwest, USA. This field data driven work concluded that the drainage area required for channel initiation is directly correlated to the slope of the contributing area. However, there are a host of related variables that have yet to be examined in the field. This study revisits the slope-area relationship focusing on ephemeral overland flow in headwaters of both the Pacific …


Arsenic Mobilization From Silicic Volcanic Rocks In The Southern Willamette Valley, Gabriela Ribeiro De Sena Ferreira Mar 2016

Arsenic Mobilization From Silicic Volcanic Rocks In The Southern Willamette Valley, Gabriela Ribeiro De Sena Ferreira

Dissertations and Theses

Volcanic tuffs and tuffaceous sediments are frequently associated with elevated As groundwater concentrations even though their bulk As contents (~ 5 mg kg-1; Savoie, 2013) are only marginally greater than the average crustal abundance of 4.8 mg g-1 (Rudnick & Gao, 2003). Thus, As mobilization must be facilitated by conditions particular to these rocks. Alkaline desorption, anionic competition, reactive glass dissolution, and reductive dissolution of iron oxides are proposed processes of As release from volcanic rocks. Geogenic As contamination of groundwater in the southern Willamette Valley in western Oregon has been well-documented since the early 1960s, and …


Field Geology And Petrologic Investigation Of The Strawberry Volcanics, Northeast Oregon, Arron Richard Steiner Feb 2016

Field Geology And Petrologic Investigation Of The Strawberry Volcanics, Northeast Oregon, Arron Richard Steiner

Dissertations and Theses

The Strawberry Volcanics of Northeast Oregon are a group of geochemically related lavas with a diverse chemical range (basalt to rhyolite) that erupted between 16.2 and 12.5 Ma and co-erupted with the large, (~200,000 km3) Middle Miocene tholeiitic lavas of the Columbia River Basalt Group (CRBG), which erupted near and geographically surround the Strawberry Volcanics. The rhyolitic lavas of the Strawberry Volcanics produced the oldest 40Ar/39Ar ages measured in this study with ages ranging from 16.2 Ma to 14.6 Ma, and have an estimated total erupted volume of 100 km3. The mafic and intermediate lavas of the Strawberry Volcanics include …


Slope Failure Detection Through Multi-Temporal Lidar Data And Geotechnical Soils Analysis Of The Deep-Seated Madrone Landslide, Coast Range, Oregon, Michael Scott Marshall Jan 2016

Slope Failure Detection Through Multi-Temporal Lidar Data And Geotechnical Soils Analysis Of The Deep-Seated Madrone Landslide, Coast Range, Oregon, Michael Scott Marshall

Dissertations and Theses

Landslide hazard assessment of densely forested, remote, and difficult to access areas can be rapidly accomplished with airborne light detection and ranging (lidar) data. An evaluation of geomorphic change by lidar-derived digital elevation models (DEMs) coupled with geotechnical soils analysis, aerial photographs, ground measurements, precipitation data, and numerical modeling can provide valuable insight to the reactivation process of unstable landslides. A landslide was selected based on previous work by Mickleson (2011) and Burns et al. (2010) that identified the Madrone Landslide with significant volumetric changes. This study expands on previous work though an evaluation of the timing and causation of …


Analyzing Evapotranspiration In The Tropical Montane Cloud Forest At Sierra De Bahoruco, Dominican Republic, Emmanuel Rodriguez-Gonzalez Jan 2016

Analyzing Evapotranspiration In The Tropical Montane Cloud Forest At Sierra De Bahoruco, Dominican Republic, Emmanuel Rodriguez-Gonzalez

Dissertations and Theses

Lake Enriquillo is located in the southwestern extreme of Dominican Republic and has been experiencing a rapid expansion in surface area, along with other water bodies in the same region, since 2004 causing major flooding to the surrounding agricultural and cattle-raising lands, infrastructure and communities. Understanding why the lake is expanding at such rapid rate and accurately forecast how they will behave in the future is the main goal of The Hispaniola Lakes Project. The purpose of this project is to investigate the effects that hydrometeorological drivers are having on the forested areas located in Sierra de Bahoruco, which is …


Modern Foraminiferal Assemblages Of The Denmark Strait, Laura Larocca Jan 2016

Modern Foraminiferal Assemblages Of The Denmark Strait, Laura Larocca

Dissertations and Theses

Foraminifera occupy a geological range from the early Cambrian to the present day. Their well preserved shells, high relative abundance, and short response time to changing environmental conditions make foraminifera ideal proxies for environmental change. Benthic foraminifera are a valuable but poorly understood paleobiological proxy for the reconstruction of environmental conditions on continental shelves occupied by arctic and subarctic waters. This study identifies, examines, and quantifies calcareous benthic foraminiferal faunas from a sediment core taken from the Denmark Strait. Our analysis of three-thousand individuals from ten discrete samples aim to provide a better understanding of the modern patterns of foraminiferal …


Assessing The Utility Of Imaging Radar For Identifying White Sand Vegetation Structure, Jessica Rosenqvist Jan 2016

Assessing The Utility Of Imaging Radar For Identifying White Sand Vegetation Structure, Jessica Rosenqvist

Dissertations and Theses

White sand vegetation communities are wide spread across South America; found in Peru, Venezuela, Brazilian Amazon and Guyana. They are distributed in patches ranging from <1 km2 to greater than tens of square kilometers and their origins and locations are still not well understood. The communities are related to a variety of factors (soil type, flooding, nutrient content and fire); hence a precise definition for the ecosystem is still not fully defined. Nevertheless, the result of these variations creates a unique environment for endemic plant and animal species to thrive. Furthermore, analysis of these areas has been very scattered and identification of local white sand areas (<1 km2) have not been accomplished. In addition, identification of these locations has currently only used optical satellite imagery (Landsat, MODIS). Hence, in this project, we have attempted to use synthetic aperture radar to create a classification system to locate the white sand vegetation systems. The goal is to be able to apply this method to identify white sand vegetation distribution across South America. The region of focus for this thesis has been in Aracá, a large white sand area located in Brazil in the State of Amazonas. Due to the lack of ground reference data, a classified map by Capurucho et al. (2013), generated using Landsat data, was used as a comparison and reference. JAXA’s ALOS-1 PALSAR (L-band), ESA’s Sentinel-1A (C-band) and NASA’s SRTM sensors were used for land classification. As microwave signals penetrate clouds and haze, the advantage of using sensors with this wavelength allows for an unobstructed coverage of the landscape all year round. Different combinations of polarizations and wavelengths were used during the analysis to try and separate the white sand vegetation from water and terra firme forest. The resulting classification images showed a 30% agreement with the classification map by Capurucho et al. It is important to note, that this number is in fact an agreement percentage as the map used was a classification image and coarse in resolution (due to the lack of reference data). Therefore, this value does not imply a bad classification. Future work will include time-series data, precise ground reference points and data from other sensors such as ALOS-2 PALSAR, to improve the classification accuracy.


Adsorption Of Antibiotics By Vermiculite, Mosa J. Ferdous Jan 2016

Adsorption Of Antibiotics By Vermiculite, Mosa J. Ferdous

Dissertations and Theses

The occurrence of residual antibiotics in the environment has been a worldwide issue and warrants the development of inexpensive yet effective methods for antibiotics removal from contaminated water. In this thesis work, the adsorption of four antibiotics, namely chlorotetracycline (CTC), oxytetracycline (OTC), ofloxacin (OFL), and enrofloxacin (ENR), onto natural vermiculite has been studied using batch (static) and column (dynamic) adsorption techniques. The Langmuir and Freundlich isotherm models were initially used to explain the adsorption processes. The separation factor (RL) values derived from the Langmuir model and the 1/n values derived from Freundlich model in the present investigation were less than …


3d Structural And Stratigraphic Architecture Of The Northwest Santa Barbara Basin And Implications For Submarine Landslide Generation, Alexis Wright Jan 2016

3d Structural And Stratigraphic Architecture Of The Northwest Santa Barbara Basin And Implications For Submarine Landslide Generation, Alexis Wright

Dissertations and Theses

Multiple submarine landslides have been previously documented on the north flank of the Santa Barbara Channel, and such failures are considered to be capable of generating local tsunamis hazards to the Santa Barbara region. 2D seismic-reflection datasets provide a general view of regional framework geology, including faulting and folding associated with north-south compression. However, better understanding of the relationships between faults, folds, stratigraphic architecture, and submarine landslides can be obtained with 3D seismic datasets. In this study we use an industry 3D seismic-reflection volume that encompasses the slope and shelfbreak surrounding the Gaviota submarine landslide (3.8 km2) to investigate structural …


Evidence For The Drainage Of A Superglacial Lake As The Source Of Seismic Waves Recorded At A Regional Distance, Erik J. Orantes Jan 2016

Evidence For The Drainage Of A Superglacial Lake As The Source Of Seismic Waves Recorded At A Regional Distance, Erik J. Orantes

Dissertations and Theses

Surface melting during the summer leads to the formation of lakes on the Greenland Ice Sheet surface, known as supraglacial lakes. Some of these lakes drain through cracks in their beds and release the water into the ice sheet. Previous studies suggest that some of the water reaches the bedrock, enabling basal sliding, which could potentially increase glacial discharge (Sundal et al., 2009). Das et al. (2008) showed that supraglacial lake drainage can be accompanied by seismic activity, but little work has been done on the regional detection of such waves. The present study analyzes seismic data for the period …