Paleoclimate records from glacial Indian and Pacific oceans sediments document millennial-scale fluctuations of subsurface dissolved oxygen levels and denitrification coherent with North Atlantic temperature oscillations. Yet the mechanism of this teleconnection between the remote ocean basins remains elusive. Here we present model simulations of the oxygen and nitrogen cycles that...
In the face of dramatic declines in groundfish populations and a lack of sufficient stock assessment information, a need has arisen for new methods of assessing groundfish populations. We describe the integration of seafloor transect data gathered by a manned submersible with high-resolution sonar imagery to produce a habitat- based...
One of the most persistent questions regarding the phase equilibria of mid-ocean ridge basalts (MORB) pertains to the petrogenesis of the anorthitic plagioclase phenocrysts (>An₉₀) that are characteristic of the more primitive members of such suites. Anorthitic phenocrysts are present in many if not most MORB suites in spite of...
Debris flows have typically been viewed as two-phase mixtures of sediment and water, but in forested mountain landscapes, wood can represent a sizable fraction of total flow volume. The effects of this third phase on flow behavior are poorly understood. To evaluate whether wood can have a significant effect on...
Steepland valleys subject to debris flows incise bedrock even as episodic deposition typically covers valley bottoms. This paper’s hypothesis is that, while continual fluvial processes evacuate deposits, storage of episodic deposition drives valley widening and, thereby, creation of accommodation space for sediment storage on the valley floor. Data from three...
The magnitude, seasonality, and duration of peak discharge responses to forest removal and regrowth and roads in 10 pairs of experimental basins in the western Cascade Range of Oregon are consistent with fundamental water balance and routing concepts in hydrology. Hypothesized effects of forestry treatments on evapotranspiration, cloud water interception,...
This study examined daily streamflow response over up to four decades in northwest conifer forest and eastern deciduous forest sites in the United States. We used novel methods to analyze daily observations of climate and streamflow spanning more than 900 basin years of record at 14 treated/control basin pairs where...
The modeling of fluvial systems is constrained by a lack of spatial information about the continuity and structure of streambed sediments. There are few methods for noninvasive characterization of streambeds. Invasive methods using wells and cores fail to provide detailed spatial information on the prevailing architecture and its continuity. Geophysical...
We propose the experimental use of resazurin (Raz) and develop a metabolically active transient storage (MATS) model to include processes that may provide additional information on transient storage from a biogeochemical perspective in stream ecosystems. Raz is a phenoxazine compound that reduces irreversibly to resorufin (Rru) in the presence of...
We have reconstructed chronology for the disturbed bottom parts of the GRIP and GISP2 ice cores using the combined paleoatmospheric records of CH₄ concentration and δ¹⁸O[subscript atm] in the trapped gases. Our reconstructed ages for basal ice samples are based on comparison of published measurements of CH₄ and δ¹⁸O[subscript atm]...
Using new and existing ice core CO₂ data from 65 ∼ 30 ka a new chronology for CO₂ is established and synchronized with Greenland ice core records to study how high latitude climate change and the carbon cycle were linked during the last glacial period. Atmospheric CO₂ rose several thousand...
The origin of the Pacific Decadal Oscillation (PDO), the leading mode of sea surface temperature variability for the North Pacific, is a matter of considerable debate. One paradigm views the PDO as an independent mode centered in the North Pacific, while another regards it as a largely reddened response to...
The High Lava Plains province (HLP) is a late Cenozoic bimodal volcanic field at the northern margin of the Basin and Range province in southeastern Oregon that hosts a westward younging trend of silicic volcanism that crudely mirrors northeastward migration of silicic volcanism along the Yellowstone–Snake River Plain (YSRP) trend....
The collapse of the Laurentide Ice Sheet over Hudson Bay ∼8.47 ka allowed the rapid drainage of glacial Lake Agassiz into the Labrador Sea, an event identified as causing a reduction in Atlantic meridional overturning circulation (AMOC) and the 8.2 ka cold event. Atmosphere‐ocean models simulations based on this forcing,...
Coral reef ecosystems are the most diverse on earth, and their subsistence is being threatened by natural and adverse anthropogenic patterns and processes. In an effort to understand and protect these marine environments, several programs have outlined strategies and initiatives. For example, the United States Coral Reef Task Force’s Mapping...
New seafloor mapping and sampling demonstrates that the eruption of the high-Ca boninites is clearly associated with rifting of the northern Tonga ridge and the northern Lau Basin at the northern termination of the Tonga Trench. There is very strong evidence for OIB plume related mantle sources involved in the...
The Mount Fubilan Intrusion is part of a geologically young hypabyssal stock in the Star Mountains of Papua New Guinea. This stock was mapped as the Ok Tedi Intrusive Complex and divided into four separate bodies: the Mount Fubilan, Sydney Intrusion, Kalgoorlie, and Ningi Intrusions. Hydrothermal fluids caused alteration of...
A model for the spatial and temporal evolution of the gray sericitic (GS) and sericite with remnant biotite (SBr) hydrothermal alteration selvages within the Butte Quartz Monzonite (BQM) of the porphyry copper deposit at Butte, Montana, is presented. The model provides a mathematical description for the location and advance of...
This thesis presents a hydrogeologic study of the Parrett Mountain Region,
located approximately 20 miles south of Portland, Oregon. The aim of the study was
to investigate the impacts of Columbia River Basalt on the regional groundwater
system, to expand our understanding of flow through fractured basalt, to improve
management...
Glacial deposits on San Francisco Mountain, Arizona, were mapped in order to provide constraints on ice extents in separate valleys for late Pleistocene glacial events. Qualitative and semi-quantitative relative dating methods were employed in order to correlate moraines between drainages and to provide a basis for distinguishing between separate glacial...
Fast ice flow and unstable ice sheet behavior were characteristic features of the Lake Michigan Lobe of the southern Laurentide Ice Sheet. Such behavior may result from some combination of subglacial-sediment deformation and decoupled sliding at the ice-bed interface. Both mechanisms depend on high water pressure relative to ice pressure....
The High Lava Plains province (HLP) of southeastern Oregon is a Miocene to Recent volcanic upland characterized by widespread basaltic volcanism and west-migrating rhyolitic volcanism. New ⁴⁰Ar/³⁹Ar ages for HLP rhyolites demonstrate that the trend of migrating rhyolitic volcanism is robust, reflecting westward migration at a rate of -35 km/m.y....
The San Vicente zinc lead deposit is located in the Eastern Andes of
Central Peru. The deposit is an epigenetic Mississippi Valley-type deposit
based on stratigraphic, geologic, petrographic, and geochemical evidence.
The dolomite host rocks of the Pucara Group are of Triassic-Jurassic
age. The source of metals are red sandstones...
As part of a study to determine the history and potential for conflict in international freshwater
basins, an estimate was made of the location of arable and irrigable land in the world.
Knowledge about the world's arable and irrigable land was desired since this information could
be an indicator of...
El Niflo and La Nifia are oceanographic and atmospheric phenomena that have been
catalogued for well over a centuly. In El Nifio years, Peru's otherwise thy west coast is
subjected to torrential rainfall. Higher ocean temperatures off the coast are deemed the
culprit. Attempts to quantify this began in the...
This paper evaluates Oregon Statewide Planning Goal 5: Natural Resources and Goal 17
Coastal Shorelands, planning programs and makes recommendations for improvement to the
Oregon members of the Columbia River Estuary Study Task Force (CREST). CREST is a
Council of Governments formed in 1974 which includes the local counties, cities...
Networks are a structure common to many disciplines. Research on
networks has taken different forms in domains such as graph theory, sociology,
vascular networks, small-world networks, geomorphology, ecology, evolution and
engineering. Networks may be modeled as non-spatial networks (unvalued
graphs), which contain only topological information, or as spatial networks (valued...
The main purpose of this project is to describe the hydrologic characteristics, with and without
regulation by dams, of the Coast and Middle Forks of the Willamette River, including the
floodplain, from the confluence to approximately eight miles upstream. The research is intended
to assess the future potential of the...
The purpose of this paper was to examine if the depth and degree of circularity of weathering pits affects the accumulation of sediment. Thirty pits were surveyed over two one-week periods on Dance Hall Rock. Weathering pits were measured to determine their maximum width, minimum width, vertical depth, and depth...
One of the most pressing concerns in the Geographic Information Science community is the distribution of spatial datasets over the Internet. Two projects of the Department of Geosciences at Oregon State University are in the process of distributing data. The Oregon Coast Geospatial Clearinghouse was implemented with the goal of...
An emergency management system integrating remote sensing and geographic
information systems applied to emergency preparation, response, and recovery could
have reduced casualties and damage after the August 17, 1999 Kocaeli, Turkey
earthquake. Model system components include a horizontally and vertically distributed
knowledge base, LIDAR 3D urban modeling, automatic feature extraction,...
Ecoregions are regions of relative homogeneity with respect to specific
ecosystem variables (Bailey 1976; Omernik 1995). There has been an increasing
awareness that effective management of environmental resources must be undertaken
with an ecosystem perspective (Omernik, 1995). Ecoregions serve as a spatial
framework for assessing, managing, and monitoring ecosystems that...
The visualization of climate patterns is a major theme in cartography. Short-term
dramatic weather events such as hurricanes and tornado outbreaks are mapped and
displayed immediately in order to capitalize on the sensational nature of the events, and
to quickly and accurately convey the information to emergency workers and the...
The Geographic Information System (GIS) is an invaluable tool in manipulating and
interpreting world scale datasets. In recent years it has become the standard link between
water resource study and the ever-increasing numbers of high quality data sets. This
paper describes the use of Geographic Information Systems for gathering and...
Stream temperature response of first and second order streams to the Blue River Landscape
Study (BRLS), an alternative land management strategy based on historic fire regimes, was
analyzed in the central Oregon Cascades. The BRLS treatment prescription of a 50% canopy
reduction and low intensity burn was applied with a...
The application of the collinearity solution by resection of the interior and exterior
orientation parameters of historical photographs is investigated. The spatial coordinates of seven
or more identifiable control points in the field of view of an historical photograph, combined
with image coordinates of the control point images, allow solution...
In this study, LIDAR, light detection and ranging, was examined as to its ability to
depict the existence of forest roads and 'legacy' roads. LIDAR is most often used to
'see' though the trees or vegetation to get an accurate representation of the terrain. As
opposed to trying to remove...
This study traces the development history of the city of Corvallis, Oregon. Historic
reconstruction methods and GIS analysis are used to define and describe spatial aspects of the
city's expansion through time.
Pre-settlement and early settlement landscape conditions are considered. The city's
history is divided into three time periods, 1845-1900,...
Many studies have looked at human settlements around individual volcanoes for
volcanic risk analyses, but few have done a comparative study to identify possible global
patterns. With the use of Landsat ETM+ data, this study identifies and compares urban
proximity to the Decade Volcanoes to identify volcanic settlement patterns. These...
Tsunamis pose a major threat to Oregon's coastal communities. Evacuation is
the best method to mitigate for tsunamis. Planning for tsunami evacuation is underway
in Oregon's coastal communities. Current methodologies use tsunami inundation
models and population for evacuation planning. Tsunamis from a Cascadia subduction
zone (CSZ) earthquake will create more...
Despite their significance, physical interactions between surface and
groundwater have largely been ignored in international water law. While surface water
has been given considerable attention as a transboundary natural resource, groundwater
has not received the same recognition. International legal doctrines regarding water, such
as the 1997 United Nations Convention on...
This paper discusses the methods used to create a maintainable
tracking system for used by the City of Corvallis' Plaiming Division for the
purpose of historic preservation. The system includes a Microsoft Access2000
database and an ArcView GIS component. In addition to this, there is a web site
component of...
The purpose of this study was to better understand the level of
wetland classification consistency among three different land cover layers
created using Geographical Information System (GIS) and remote sensor
technology. Where inconsistencies in data existed, the goal was to identify the
kinds of inconsistencies that occur. The results were...
The purpose of this study was to document the initial change in vegetative canopy cover
following winter seismic exploration on the North Slope of Alaska. The study conducted herein
focuses solely on the impact to wet sedge meadow vegetation.
The overarching goal of this study is to contribute some level...
Three (3) streams with desired similar characteristics, located in the Blue River
Watershed in the Central Oregon Cascades, were studied to better understand the impacts
of forest harvest on stream temperature and aquatic habitat. Of the 3 designated streams,
North Fork Quartz Creek, Blue River Face, and Wolf Mann, only...
Arizona has experienced tremendous growth in the last several decades, typically
characterized by sprawling suburban, polycentric or edge city development. Unchecked growth or
"sprawl" has generated intense debate amongst various interest groups and has emerged as a
major political issue in Arizona. This paper employs a dualistic approach to land...
A healthy river ecosystem is the definitive mark of success in international water quality
planning and management, but until the world's international river basins achieve this kind of success,
there must be other means to assess progress. In this paper, a theoretical background establishes the
complexities inherent in water quality...
Nearest-neighbor resampling is a common procedure used by cartographers to
reproject raster data sets. This type of resampling is useful because it retains the data
from the original raster data set. However, during nearest-neighbor resampling some of
the original data will be lost as it is reprojected, while other data...
GIS and other geographic mapping tools have become an integral part of our
society for disseminating spatial infonnation to assist in making informed land planning
decisions. Disc golf is a recreation activity, most commonly found on public lands, which
utilizes the natural landscape in a manner that enhances its enjoyment....
The density at which urban areas are developed has become a contentious issue, with
advocates for compact cities in conflict with advocates for larger lots and suburban
development. This research paper examines the associated impact of population density
(grouped by residential zones) as measured by vegetation (Normalized Difference Vegetation
Index)...