The probable pollution distribution and flushing times have been
calculated for the Columbia River Estuary, a coastal plain estuary.
The pollution distribution was determined by the fresh water fraction
and by the diffusion equation. The flushing times were calculated by
the modified tidal prism method and by the fraction of...
The results of measurements of the fluxes of momentum, moisture and sensible heat in the marine boundary layer are described.
Two techniques for obtaining the fluxes are discussed. The fluxes
of these quantities are most directly obtained by the eddy correlation
method, that is, by measuring the fluctuating vertical and...
Several series of measurements of the hydrography, currents,
and winds during the past ten years are used as a basis for an overview
of the physical oceanography and meteorology during the
upwelling season near Newport, Oregon. Data are described using
elementary statistics, progressive vector diagrams, coordinate system
independent spectra, and...
A technique was developed in the present study to determine
fault-plane solutions for small earthquakes. The method uses the
direction and amplitude of initial P-wave motions recorded at a
small number of seismic stations for epicentral distances less than
2000 km.
Seismic arrivals recorded on short-period seismograms were
identified as...
Subduction zone earthquake and tsunami hazards affect tens of millions worldwide and the recurrence of these disasters can be evaluated with paleoseismic techniques, because earthquake cycles (and their supercycles) typically span many millennia. In these three chapters, I discuss a suite of analyses I use to evaluate the sedimentary record...
This study examines the seasonal variability in temperature and
salinity of the nearshore waters off Oregon and Northern California.
Specifically, temperature and salinity variations during summer and
winter were ana1yzed from data gathered at shore stations along the
coast and from hydrographic data collected within 25 nautical miles
of shore....
Detailed current profiles between the sediment-water interface
and 20 cm above it reveal a viscous sublayer in the bottom boundary
layer on the Oregon continental shelf. Data from three field experiments
are used to test fundamental assumptions about boundary layer
flow in the ocean. The first study, discussed in Chapter...
Phytoplankton dynamics in Auke Bay, Alaska, were studied during
summer, 1969. Nitrate, chlorophyll a, particulate organic carbon,
phytoplankton and zooplankton species composition and hydrographic
and meteorological data were collected and analyzed.
Nitrate input into Auke Bay through freshwater runoff was negligible.
A bloom of Thalassiosira aestivalis formed the spring bloom...
A three component drag probe has been built, calibrated, and
used to measure velocities beneath deep water ocean waves and
turbulence in a tidal channel. Simple variable inductance devices
which may be submerged in water were used as displacement transducers
and the associated electronics provided voltage outputs which
were proportional...
Phytoplankton are a sentinel class of organisms in the marine environment. Through their photosynthetic activity in sunlit waters worldwide, phytoplankton shape the health and productivity of marine ecosystems and impact the global climate. In this work a range of ocean sensing technologies (via ships, surf zone sampling, moorings, gliders, and...
Paleoclimate archives have revealed abrupt climate events that are superimposed on more gradual climate changes throughout the last glacial and deglacial periods. The underlying causes of such rapid climate changes are still poorly understood, but the strong expression of these events in northern hemisphere records likely points to climatic mechanisms...
Two thermal convection problems of geophysical interest are
examined, theoretically. First, convection in the earth's mantle is
treated on the basis of a one-dimensional 'strip model'. This model
results from further simplification of the well known 'Rayleigh model'.
For homogeneous, Newtonian fluids, the strip model yields results
similar to those...
Dissolved oxygen profiles made with an in situ polarographic
device reveal structure in the form of inversions and gradient
changes in the 100-600 meter depth zone off Oregon. Inversions
10-70 meters thick are traced over distances of 40 miles in some
cases and are bracketed by a distance of 8...
The oceanic phenomenon of upwelling along the Oregon coast is
examined. Upwelling in both the open ocean and coastal regions is
discussed. An idealized model is used, envisaging the ocean off
Oregon to consist of homogeneous surface and deep layers separated
by a pycnocline. The equations of motion are solved...
The thesis examines the principal air-sea properties at Ocean
Station Vessel N (30N 140W). In a descriptive section, meteorological
and oceanographic data for N are analyzed over 20 years (1951-1970)
and 7 years (1964-1970), respectively. A rainfall estimate is constructed
for the 20 year period. The yearly average rainfall is...
A multidisciplinary western Beaufort Sea Ecological Cruise
(WEBSEC) was conducted from August 15 to September 20, 1971.
During the cruise, one hundred ninety-nine 0.1 m² Smith-McIntyre
grabs samples were taken at forty stations located on the continental
shelf and slope of the western Beaufort Sea. The Gammaridean
Amphipoda and Cumacea...
The distribution of Antarctic Intermediate Water in the South
Pacific has been examined using a model of horizontal advection,
along the Sigma-t surface 27.10, with three point vertical mixing.
The core of the Antarctic Intermediate Water mass was traced
from the Antarctic Convergence northward. The charts used to
describe the...
Quantifying the mass transport through marine sediments, and the geochemical response to such flow with numerical models has become a common and powerful approach for geochemical data interpretation. In this dissertation, I developed and applied transport-reaction models to unravel complex and interdependent reactions involving carbon, sulfur and silica transformations in...
Fourier transformed amplitudes of the compressional waves
recorded between 9° and 91° (about 1000 to 10,000 km) epicentral
distance from Gnome, Shoal, Haymaker,and Bilby underground
nuclear explosions have been compared with Fourier transformed
amplitudes of P waves measured at distances between 9.0 and
1 3. 0 km from the explosions....
Marine bacterioplankton play an important role in global elemental cycles because they return carbon dioxide and nutrients to the biosphere as they reduce organic matter. Furthermore, marine bacterioplankton are not uniformly active, and subpopulations of the in situ community may be more or less active at any given time. Defining...
Five lithologic units, ranging in age from Middle Miocene to Recent,
are defined on the basis of continuous seismic reflection profile records.
Two of the units are Miocene sedimentary and volcanic rocks that have been
truncated to form a major unconformity (post-orogenic surface) related to
the most recent major tectonism...
Small pelagic fish represent a critical trophic link between plankton and large predators in marine upwelling ecosystems such as the California Current System. Populations of these fish are highly variable over time and are characterized by extreme fluctuations in abundance, which have significant ecosystem impacts. The causes driving
this instability...
Euphausia pacifica, the North Pacific krill, is a key grazer in the California Current System and an important prey item for consumers such as salmon, seabirds, and whales. As a crucial link between phytoplankton and higher trophic levels, it is essential to understand both the behavior and bioenergetics of this...
Third order spectra computed from the rotary components of
winds and currents at the TOTEM buoy site off the Oregon coast provide
an insight to the nonlinear, quadratic interactions within and between
these vector fields. The topography of bispectra and cross-bispectra
as displayed on four tri-frequency planes shows that significant...
Calanoid copepod diet was investigated in Oregon coastal waters to determine
the trophic significance of phagotrophic protists as copepod prey within an ecosystem
where the microplankton biomass is typically dominated by large diatoms. Prior to and
during the 1991 upwelling season, clearance rates on phytoplankton and phagotrophic
ciliates were measured...
Radioactive chromium-51, a waste byproduct from operation
of nuclear reactors at Hanford, Washington, has been followed down
the Columbia River and into the Pacific Ocean. Chemical factors
influencing the partitioning of ⁵¹Cr between solution and sediment
have been considered.
Chromium-5l, in a hexavalent oxyanion when introduced into the
Columbia River,...
The climate and the exchange of heat between atmosphere and
ocean are examined in a region adjacent to Washington and Oregon,
and in two sub-regions adjacent to Oregon. The sub-regions are
chosen such that one contains the nearshore upwelling region and the
other borders it on the seaward side.
The...
The effects of alongshore variability in topography (banks and capes) and spatial variability in the wind forcing, including the wind-stress curl, on coastal ocean circulation are studied using a combination of observations and model simulations. Satellite sea surface temperature observations are used to describe the seasonal evolution of temperature fronts...
I compare the seasonal abundance variation, population dynamics, fecundity, egg hatching mechanism and success, and apostome ciliate parasites of the euphausiids Euphausia pac?fica and Thysanoessa spinfera from the Oregon coast, USA. Community structure and nearshore distributions were examined from bi-weekly oceanographic surveys (1970-1972). This region has a strong cross-shelf change...
Sediments on the inner portion of the Oregon continental shelf
consist of clean, well-sorted, detrital sand. This sand has an average
median diameter of 2.53Φ (. 173 mm) and is both positively and
negatively skewed. Deposits with median diameters in the coarse
sand and gravel classes occur at depths of...
Seismic refraction measurements along two unreversed lines
indicate that the earth's crust is 26 km thick in southeastern Alaska
and 30 km thick along the Inside Passage of British Columbia. The
crust in southeastern Alaska, north of Dixon Entrance, consists of
a layer 9 km thick with a seismic velocity...
A new method is introduced for incorporating bathymetric uncertainty into predictions of nearshore and river flows (i.e., unstratified flows primarily forced by pressure and radiation stress gradients). The method involves the use of the ensemble Kalman filter (EnKF) as a parameter estimation scheme, where the parameter to be estimated is...
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...
We examine the interactions and feedbacks between bathymetry, waves, currents, and
sediment transport. The first two pro jects focus on the use of remote sensing techniques
to expand our knowledge of the nearshore. Due to the plethora of snap-shot data that is
available from satellites and their distribution via Google...
This thesis describes the development of a rare earth element (REE) proxy for paleoceanographic studies of climate change. This work was done in three stages with the goal: (1) To develop a cleaning method that overcomes the problems of REE readsorption; (2) To measure pore water REEs for evaluation of...
Dramatic and ongoing changes pervading the Arctic and subarctic seas over
recent decades have motivated this effort to track and better understand hydrographic
variability using chemical tracers. Particular emphasis has been paid to differentiating
freshwater contributions to upper layers: namely Pacific water, meteoric water, and
sea-ice melt/formation.
Data collected in...
Plate boundaries are commonly regions of complex, diffuse deformation with
the motion across the boundary accommodated by numerous structural systems, rather
than being narrow, discrete zones of deformation. One such boundary occurs where
the North American plate makes contact with Juan de Fuca, Gorda, and Pacific plates
along the west...
An investigation has been made of several physical parameters of the effluent plume of the Columbia River as it enters the Pacific
Ocean. Radioactive material in trace amounts enters the Columbia River from the Hanford nuclear reactors at Richland, Washington. One of these nuclides, chromium -51, has been used to...
Fifty-two one-meter plankton net samples from four stations off Newport, Oregon, were examined for composition and abundance of euphausiids and copepods. They provided data on dominance, species associations and environmental relationships. The euphausiid-copepod population off Oregon is composed of 12 numerically dominant species. These species occurred in most of the...
The foraminiferal population of Yaquina Bay was investigated
to attempt a correlation of seasonal changes in the hydrography with
observed changes in the faunal distribution patterns. The results
are based on data from two spatial surveys conducted in July 1966,
and late February and March, 1967.
The hydrography of Yaquina...
Changes in environmental conditions in marine ecosystems could directly or indirectly influence distribution, abundance, settlement, and size at settlement of flatfish. Understanding species-specific and age-specific responses to environmental variability is important for managing commercially important flatfish stocks. Slope-spawning flatfish whose offspring rely on extensive drift from the slope (spawning) to...
Within systems characterized by substantial spatial and temporal variability, abundances of organisms tend to be higher in localized areas. Within the northern California Current system, the identification of such marine, biological hotspots would be of great importance to resource managers, conservationists, and research planners, and is consequently a growing area...
The subaerial beach, composed of sand dunes and the foreshore, provides a natural buffer zone between vulnerable land and the dissipation of storm wave energy due to wave breaking. The natural beauty of this region is attractive to people, and as a result, significant investment has been placed in this...
Understanding and modeling microbial responses and feedbacks to climate change is hampered by a lack of a framework in the pelagic environment by which to link local mechanism to large scale patterns. Where terrestrial ecology draws from landscape theory and practice to address issues of scale, the pelagic seascape concept...
Bimonthly plankton samples were collected from 1969 through
1971 along a transect off the central Oregon continental shelf (44°
39. l'N) to document the species of crab larvae present, their seasonality,
and their onshore-offshore distribution in relation to seasonal
changes in oceanographic conditions. A comprehensive key with
plates is given...
Experiments were designed to answer key questions about diatom-derived organic matter cycling (i.e., production and degradation) in coastal systems. Dissolved organic matter (DOM) production was examined in axenic batch cultures of five diatom species. Dissolved organic carbon (DOC) release rates varied between species, but were significantly higher for all species...
This dissertation investigates the dynamics of the tidally modulated outflow from the Columbia River mouth using high resolution measurements of velocity, density and turbulent microstructure. At high tide, flow through the river mouth reverses from flood (onshore) to ebb (offshore). During ebb, buoyant fluid issues from the river mouth and...
A mooring system was designed and constructed to make possible
the installation and the recovery of racks of sample panels for
a study of deep-ocean wood-boring molluscs. Racks containing
pine, fir, oak, and cedar boards were exposed to borer attack at
six stations with depths of 50, 100, 150, 200,...
The brine shrimp, Artemia, was used as an experimental
organism to study the effects of ⁶⁰Co gamma irradiation on the reproductive
performance of an animal population. The total reproductive
ability of the brine shrimp was fractionated into various components
and the effects of irradiation on each of these components
was...
Large-volume (20-liter) bioassays were carried out in order to
assess the effects of major nutrients and micro-nutrients on
natural phytoplankton populations in water collected from a site
close to the mouth of Yaquina Bay, Oregon. Seven long-term
experiments were conducted during the years 1975-1976. A stripping
technique employing activated carbon...
Global increases in ultraviolet-B radiation (UVBR:290-
320 nm) resulting from decreases in stratospheric ozone
concentration have the potential to alter marine primary
production and affect global climate and marine trophic
dynamics. Effects of UVBR on phytoplankton carbon fixation
were determined from open ocean exposure studies conducted
off the coast of...
We sharpen our view of an eastern boundary current region during
the upwelling season through the analysis of several data sets.
We focus on the mesoscale flow field off of northern California,
observed during the Coastal Transition Zone (CTZ) experiment of 1988.
First, we estimate tidal currents in the region...
Fourier techniques have recently become popular for the
description of underwater image transmission. Two properties
necessary for the application of Fourier techniques to any system
are those of linearity and invariance. This work describes a
laboratory investigation of these properties for a variety of
aqueous media. The hypothesis is found...
This research incorporates geochemical and helium isotopic analyses of Lau Basin volcanic glasses, along with helium isotopic analyses of water column hydrothermal plumes to better understand the processes that control the formation and evolution of this backarc basin. Lavas newly collected from the four southernmost segments of the Valu Fa...
This thesis investigates the behavior of major inorganic nutrients (P, N, Si), trace metals (Mn, Fe), and alkaline-earth metals (Ba) within Tillamook Bay over seasonal cycles and under a range of river discharge conditions from October 1997 through December 1999. Located in the Pacific Northwest region, Tillamook Bay is an...
The Pacific Ocean basin is home to a set of hotspots diverse in their eruption
rate, duration of volcanism, and basalt chemistry. Pacific hotspots are found in a
spectrum of distinct plate tectonic settings, from near a spreading ridge to intraplate.
Cobb hotspot, which resulted in formation of the Cobb-Eickelberg...
The continental terrace west of Oregon between 43° 50'N and
44° 40' N latitude is 50 to 55 miles wide. It consists of a continental
shelf, 16 to 35 miles wide, and a continental slope, 16 to 37 miles
wide. The eastern portion of the shelf is a smooth, sediment...
Marine sediments contain an abundance of methane that is biologically produced
and plays a significant role in the global carbon cycle. Microbes responsible for the
carbon cycle in marine sediments, and the processes that they carry out, need to be
characterized in order to fully understand the role of this...
