The behavior of the shore crab Hemigrapsus oregonensis was assessed
with and without exposure to polychlorinated biphenyls (Aroclor 1260).
After describing the crab's behavioral repertoire, activity budgets were
developed from observations of the time crabs spent in 20 categories of
shelter use, posture, and activity while held in habitat replicas...
Using wave and wind data from nearby buoys and gauges, real time
kinematic global positioning system (RTK-GPS) and light detection and ranging
(lidar) topographic survey data, and a robust video record, we have quantified the
Large Scale Coastal Behavior (LSCB) of a dissipative end member beach in the
Pacific Northwest....
The motions of a small spar buoy were measured in deep water.
The measured variables were two buoy tilts, three accelerations, two
wave slopes and the wave height. The variables were corrected for
buoy motion and rotated to stationary coordinates, Fast Fourier
Transformed, and analyzed spectrally. Analysis included power
spectra,...
The portion of the East Pacific Rise (EPR) between 5° and 12°S
can be subdivided into three areas by fracture zones that offset the
rise axis at about 6.5°S and 9°S. In all three regions, the spreading
axis of the EPR is defined by a topographic block 300 to 350...
Tropical coral reef ecosystems are very important from both the ecological and economical
points of view. However, they are also particularly fragile, and have been
declining in recent years in most regions of the world, since they are highly susceptible
to anthropogenic stressors operating at global scales (e.g., global warming...
Waves are the primary input of energy in the nearshore region, and together with the currents forced through the transfer of momentum that occurs during the wave breaking process they are the principal mechanism for sediment transport in the nearshore. The basic physics of waves and currents are thought to...
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...
Birth and pupping season records of Pacific harbor seals
(Phoca vitulina richardsi) were used in an analysis of
photoperiod effect on the timing of birth in this species. Dates
and latitudes of births were converted into photoperiods using a
photoperiod equation. Sequential dates from parturition were
converted into photoperiods and...
Illite, chlorite, montmorillonite and kaolinite, as well as
natural marine sediments and mixtures of the standards were subjected
to density separation by centrifugation in a linear heavy-liquid
gradient.
The density layers yielded by centrifugation were recovered
and analyzed by X-ray diffraction. Separates were not monomineralic
but rather were polymineralic usually...
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...
Moored instrument records, drogue displacements, and hydrographic
observations are used in describing the coastal currents and
upwelling off Peru. The data were obtained over the continental shelf
near 15°S. during a two week study in late March and early April of
1969.
First order statistics and graphical representations of current...
Coastal-based high-frequency (HF) radar systems are an increasingly used tool for measuring surface currents in the coastal ocean. These systems provide a spatial and temporal resolution not achievable with other methods. Standard-range sites typically generate hourly maps of surface currents on a 2km grid extending approximately 50km from shore while...
Current observations were obtained at three locations forming
a cross section along 70°34'W longitude in Long Island Sound. Fifteen
days of data were selected from each series so that nearly
simultaneous observations were used in the analysis.
Elementary statistics were computed for the data prior to
performing a least squares...
Direct measurements of vertical water motions were made in
the Oregon coastal region during the 1972 summer upwelling season.
The instruments used were the Webb-Voorhis vertical current meters
which are freely drifting neutrally buoyant floats capable of sensing
vertical motion. It was found that in the region studied, water tended...
The effectiveness of the passive anti-roll tank system aboard
the R/V YAQUINA was determined. Measurements of ship roll,
effective waveslope and tank water transfer were analyzed using a
systems analysis technique. Time series of the inputs and outputs of
the ship/tank system and of the tank itself were processed using...
A weather station was established on the dock of the Oregon State
University Marine Science Center, Yaquina Bay, Oregon. A total of
197 weather observations was made from 30 June 1966 to 23 September
1966, with emphasis on the determination of the rate of evaporation
from an evaporation pan and...
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...
Thermohaline interleaving is an important mechanism for laterally fluxing salt, heat, and nutrients between oceanic water masses. Interleaving is driven by a release of potential energy resulting from the vastly differing diffusivities of heat and salt in seawater. The flows are composed of stacked intrusions that flux more buoyant and...
Wind-driven coastal upwelling brings subsurface water onto the central-Oregon shelf after the spring transition each year. This cold and salty source water is oxygen-poor, yet above the hypoxic threshold, dissolved oxygen < 1.4 ml l⁻¹. Once on the shelf, dissolved oxygen (DO) concentrations of upwelled near-bottom waters are modified by...
Autonomous buoys were deployed in 2011 in the central Arctic: An Ice-Tethered Profiler (ITP) and Ice Mass Balance (IMB) buoys were deployed in the Makarov basin; a Polar Ocean Profiling System (POPS) and Ice Thickness (Ice-T) buoy were deployed on the Eurasian Basin. The two different sites were approximately 70km...
Sea level and current observations made over the Oregon
continental shelf exhibit wavelike characteristics in a frequency band
from approximately 0.15 to 0.45 cpd. In a narrow band around
0.22 cpd the current-sea level relationship is consistent with the
predicted values for the first mode of Robinson's continental shelf
waves....
A long and gradual transition between the summer and winter
oceanic regimes was observed off Oregon during the autumn of 1980.
Hydrographic sections and a single current meter mooring between
August and December show the ocean possessed characteristics during
fall that have not been observed during other seasons: a slow...
Freshwater provided from river discharge influences the dynamics and circulation of most continental shelves around the world. It has profound effects on the transport and fate of materials and substances originated from rivers and estuaries, as well as on the ocean biogeochemistry and marine ecosystems. The effect of buoyancy forcing...
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...
Short-term changes in the distribution, surface to 10 meters, of
phytoplankton-associated trace metals (Fe, Mn, Cr, Zn, Co, Ni, and
Cu) were studied in the near-shore waters off Humboldt Bay,
California, through the summer of 1971. The depth distribution of
phytoplankton-associated trace metals was related to local hydrography.
During periods...
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...
The fall-winter surface current field off Oregon was determined by analysis of ten years of drift bottle data. Computer programs were developed for generating bottle tracks on a numerical grid, for interpolating bottle velocity components to fill void grid points and for smoothing irregularities in the velocity fields. Charts are...
The objectives of this dissertation were to describe the complex oceanographic conditions around the Galápagos Archipelago (eastern equatorial Pacific), their seasonal variability, and their effects on patterns of cetacean occurrence. The physical and ecological factors leading to a plume of high phytoplankton biomass in the wake of the Galápagos were...
Thermal structure in the seasonal thermocline at Lake Tahoe was
investigated through the analysis of vertical temperature profiles
taken in the upper 70 m during late summer stratification. Different
ranges of horizontal and temporal scales were sampled in each of
three subsets of finestructure profiles: (1) a three-week sequence
at...
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...
Two separate studies on the distribution of gammarid amphipods in the bathyal and abyssal benthic environments demonstrated that different assemblages could be found at a single depth over distances on the order of 100 kilometers. These studies evaluated changes in the species composition and relative abundance of the amphipod assemblage...
Rates of benthic O₂ exchange are important measurements for determining organic matter remineralization, and can shed light on factors driving biogeochemical processes in coastal environments. Measurement of in situ O₂ consumption and production within permeable sediments, such as those found over ~43% of the Oregon-Washington shelf, has traditionally been done...
The objective of this study was to ascertain the magnitude and
distribution of rainfall over coastal waters of the northwestern United
States and to compare values with those at nearby land stations.
Precipitation was measured with gauges at Totem, rainfall amounts
were assessed from weather reports at lightships off the...
Discrete layers of phytoplankton and zooplankton were observed over the Oregon continental shelf in summer and fall of 2001 and summer 2002 using optical and acoustical technologies and a pump sampling system. Layers of phytoplankton had steep vertical gradients which were associated with gradients in density and local peaks in...
Instability and turbulence in sheared, salt-fingering favorable stratification are studied
using three-dimensional direct numerical simulations (DNS). Salt-fingering favorable
stratification is gravitationally stable, because the unstable vertical gradient of salinity
is stabilized by temperature (warm, salty over cool, fresh water-masses). Salt-fingering
instability can occur at the interface of these different water-masses....
Interactions between surface winds and meanders in mid-latitude sea surface temperature
(SST) fronts with horizontal length scales of 100-1000 km are investigated
from satellite observations and numerical simulations. Observations from the Sea-
Winds scatterometer on the QuikSCAT satellite show that the magnitude, direction,
curl, and divergence of the surface wind...
The deglacial behavior of the sub-Arctic North Pacific is poorly constrained, with many published records suffering from limited age control due to extensive post- depositional biogenic carbonate dissolution. Potential alternative dating methods could include the correlation of stable-isotopic and/or paleomagnetic secular variation records to an independently-dated regional template, however no...
Tropical instability waves (TIWs) are prominent seasonal features in both the equatorial Pacific and Atlantic Oceans. This work quantifies their role in modulating the distributions of nutrients and phytoplankton biomass. Using an eight year record of biannual ship observations along the Tropical Atmosphere Ocean (TAO) buoy array, cruise sections crossing...
The effects of wind forcing on coastal ocean circulation are studied using a
numerical modeling approach. The first region of interest is on the North Carolina
shelf, where the Coastal Ocean Processes (CoOP) Inner Shelf Study (ISS) took place
during August - November 1994. ISS observations are used to initialize,...
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...
The mathematical and physical connections between three different ways of quantifying linear predictability in geophysical fluid systems are studied in a series of analytical and numerical models. Normal modes, as they are traditionally formulated in the instabilities theories of geophysical fluid dynamics, characterize the asymptotic development of disturbances to stationary...
Gray whales accomplish an annual migration which
spans as much as 50° of latitude in the northeast
Pacific Ocean. This migration links their summer high
latitude feeding grounds with winter calving and breeding
areas. The purpose of this study was to determine how
adult females apportion their stored lipid reserves...
The Oregon continental shelf waters are typically characterized by four to five major upwelling events that occur between May and October. The upwelled water is rich in nutrients, which fuels an increase in phytoplankton biomass. The onset of El Nino, however, can disrupt the normal physical processes along the Oregon...
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...
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...