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Rainfall over coastal waters of the Pacific NorthwestReed, Ronald Keith 30 August 1972 (has links)
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 coast, and
precipitation frequencies at lightships and land stations were examined.
Results from the three methods were quite consistent; precipitation.
on at sea was only about one-third that at coastal land stations.
These values are appreciably less than previous estimates of oceanic
rainfall in this area, and they support the view that a significant
horizontal gradient of precipitation may exist between the coast and
open sea. Rainfall typically occurs both at sea and ashore on the
same day, but it rains fewer hours at sea. The relative amount of
rain at sea varies with the type of atmospheric system, and rainfall
at the coast appears to be intensified by frictional processes.
Estimates of evaporation minus precipitation are less negative
than earlier ones; consideration of their relation to surface salinity
leads to distributions that are in good agreement with oceanographic
knowledge. The newer values suggest that in this region the heat
gain by the atmosphere may be less (but moisture entrainment may
be greater) than was thought. / Graduation date: 1973
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A study of carbon dioxide partial pressures in surface waters of the Pacific OceanGordon, Louis Irwin, 1928- 20 November 1972 (has links)
Graduation date: 1973
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Temperature and velocity fields near the deep ocean floor west of OregonKorgen, Benjamin Jeffry 09 May 1969 (has links)
Graduation date: 1969
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Marine geology of Astoria deep-sea fanNelson, C. Hans (Carlton Hans), 1937- 13 February 1968 (has links)
Graduation date: 1968
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Crustal structures in the Pacific Northwest states from phase-velocity dispersion of seismic surface wavesChiburis, Edward Frank 08 August 1965 (has links)
Graduation date: 1966
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Sources, dispersal, and contributions of fine-grained terrigenous sediments on the Oregon and Washington continental slopeKrissek, Lawrence A. 13 April 1982 (has links)
Holocene hemipelagic deposition of terrigenous silts and clays
dominates sedimentation on most of the Oregon and Washington continental
slope. The sources of these sediments, the mechanisms causing sediment
dispersal, and the relative contributions of the various continental
sources to the marine deposits have been investigated using quantitative
mineral and geochemical data for the 2-20 μm and the <2 μm size fractions.
In the 2-20 μm size fraction, material derived from the Klamath
Mountains and the California and Washington Coast Ranges contains
chlorite and illite, but only Klamath material contains hornblende.
Columbia River material lacks chlorite, and the Oregon Coast Range
source is dominated by smectite. In the <2 μm fraction, source area
compositions are less distinctive due to the ubiquity of smectite, but
the northern and southern sources again contain both chlorite and
illite. Regional and local mineralogic and textural variations in the
fluvial sediments reflect geologic and geographic changes between
drainage basins. Amorphous material is a minor component in the 2-20 μm
fraction of the fluvial sediments, but may form 25-50% of the <2 μm
fraction in some source areas.
Sediments derived from all source areas are transported north
and northwestward across the margin, either by a poleward-flowing
undercurrent along the slope, by wind-driven surface currents on the
shelf and associated turbid layers on the slope, or by a combination
of the two processes. Columbia River <2 μm material may also be carried
southward along the shelf and upper slope by summer surface currents.
The poleward undercurrent (an eastern boundary undercurrent) appears to
have limited sedimentological significance when compared to the role
of the western boundary undercurrent in sediment transport and deposition
on the continental slope and rise of the eastern United States.
Linear programming has been applied successfully to estimate source
area contributions to the 2-20 μm marine sediments. The influence of
each source is largest in proximal environments, and the contribution
estimates indicate that material derived from each source area is
transported northward along the margin. Similar estimates for the
<2 μm material are considered unreliable because of internal inconsistencies
and the uniform nature of the <2 μm compositions used in the
modelling. The contributions have been used to calculate a sediment
budget for the 2-20 μm fraction. This budget indicates that the mass
accumulating on the entire slope within the study area contains 47%
Columbia River, 32% Klamath Mountain, and 21% California Coast Range
material in the 2-20 μm fraction, and demonstrates the importance of
multiple sediment sources and sediment mixing in the formation of
hemipelagic sediments on the continental margin. / Graduation date: 1982
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Holocene sedimentation and potential placer deposits on the continental shelf off the Rogue River, OregonChambers, David Marshall 25 September 1968 (has links)
Changes in sea level during the past 20,000 years are recorded
in sediments taken from the continental shelf off the Rogue River,
Oregon. Sea level has risen approximately 125 m. during the
Holocene (Curray, 1965) and the general transgression has been
interrupted by several stillstands and minor regressions.
Box core samples taken in the area of investigation depict the
nature of sedimentation during the last rise of sea level as well as
present-day equilibrium sediment relationships. Three sediment
facies, a recent fine-grained mud, a basal transgressive sand, and
an intermediate sediment, believed to be a mixture of the other two,
are defined on the shelf on the basis of textural parameters. The
mud facies dominates surface sediment on the central shelf while
the sand facies is the most commonly exposed on both the inner and
outer shelf.
The percentage of sand generally increases with depth in the
box cores, often producing a change in sediment facies with depth and
demonstrating the transgressive nature of the sediments. Grain-size
analysis of the sand fraction of the offshore sediments reveals that
offshore sands are finer-grained and better sorted than those occurring
on the present beaches. The offshore sands most likely
represent relict nearshore deposits and not ancient beach sands
which would occur lower in the sediment sequence.
High concentrations of heavy minerals are found in the sand
fraction of the offshore sediments as well as in beach sands in the
area. Brief stillstands of sea level may be reflected in depths where
the offshore sands contain anomalously high percentages of heavy
minerals.
Opaque minerals, chiefly magnetite, occur in placer accumulations
on the present beaches and high percentages of these minerals
in the offshore sands may be indicative of submerged beach environments
associated with stillstands of sea level. The magnetite may be
concentrated in sufficient quantity in the placers to produce detectable
magnetic anomalies, several of which have been recorded in the area.
Other lines of evidence used to determine the depths of
probable stillstands of sea level are bathymetric relief, the distribution
of shallow water fauna in sediments from deep water, and the
distribution of rounded gravels on the shelf. A compilation of the
several lines of evidence suggests several stillstands of sea level
associated with the Holocene transgression occurring at depths of
18, 29, 47, 71, 84, 102, and 150 meters. / Graduation date: 1969
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Comparison of sea level and currents off the Oregon coast using mean monthly dataMarthaler, James Gordon 06 October 1976 (has links)
Sea level and current data collected near Newport, Oregon are
compared to determine an empirical relationship from which the low
frequency (f < .1 cpd) alongshore current field over the continental
shelf is estimated from observed sea level measurements at the coast.
Regression analysis of the near-surface (20-25 m) currents
with sea level indicates the surface currents are in geostrophic
balance with the sea surface slope. Analysis of the alongshore shear
between the near-surface and deep (75-80 m) layers with sea level
shows the thermal wind relationship holds.
A near-surface regression model is developed from which the mean
monthly alongshore current 20-25 m below the surface can be estimated
with a standard estimate of error (σ[subscript ER]) less than six cm/sec.
The annual range at this depth is nearly 60 cm/sec. A regression
model for the alongshore shear is formed from which the mean vertical
shear is estimated with a σ[subscript ER] of .07-.10 cm/sec/m. The annual
range is approximately .8 cm/sec/m.
The surface currents are found to be predominantly driven by the
local meteorological conditions. Deep and near-bottom current observations
suggest the deep layer currents are primarily influenced by the
thermal wind relationship and the location of the California Undercurrent. / Graduation date: 1977
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An interpretation of the gravity and magnetic anomalies of the Rivera fracture zone, eastern Pacific OceanGumma, William Harold 07 September 1973 (has links)
Graduation date: 1974
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Vertical current measurement in the Oregon coastal upwelling regionDeckard, Dennis E. 30 August 1973 (has links)
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
to sink at depths of 40 to 60 meters under the influence of strong northward
and southward winds but that water tended to rise during the
slackening periods of a southward wind. Techniques used in processing the data, some problems encountered, and the results of four good
dives are presented along with possible correlations of vertical water
movements with wind, sea Level, and isopycnal movements. / Graduation date: 1974
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