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Constraining the duration and extent of low temperature alteration in the Pacific Ocean basinPaul, Heather J. 10 April 2008 (has links)
No description available.
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On the reduction and interpretation of ocean-floor temperature and heat flow dataShih, Keh-gong 14 November 1967 (has links)
In this thesis, the interpretation and reduction of ocean heat
flow measurements are discussed on the basis of theoretical models.
The instrument effect x heat flow measurements is investigated for the
case of long period measurements by studying the heat conduction
along the measurement probe for both steady and unsteady state bottom
temperatures. This effect is found to be unimportant. Measurement
errors due to recent bottom temperature transients are studied
and the possible magnitude of such errors is estimated. Moreover,
effects of climatic variation on the ocean floor temperature are estimated
on the basis of diffusion models. It is shown that climatic variations
with periods longer than one thousand years will be unattenuated
and will affect the entire ocean floor.
The perturbation method is used to study the effects of an irregular
topography and a variable thickness of ocean floor sediments on the heat flow. Some special examples are given to provide a comparison
between the perturbation solutions and exact solutions of similar
problems. The perturbation method is also applied to a buried body
with different thermal conductivity from its surroundings and the reliability
of the perturbation solution is examined.
Heat flow anomalies due to heat transport by magma intruded
into crustal layers is studied by solving the heat conduction equation.
It is shown that magmatic intrusions can lead to very large surface
heat flow anomalies.
Finally, the possibility of deriving the ocean floor thermal gradient
on the basis of on-ship measurements performed on sediment
cores is investigated. The results appear positive. The temperature
variations in flowing wells and the temperature variation in a cylindrical
sediment core influenced by the movement of water along the
axis of the core are also studied. / Graduation date: 1968
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The subsurface frontal zone beneath the subtropical convergence in the northeast Pacific OceanBlanton, J. O. 25 January 1968 (has links)
Graduation date: 1968
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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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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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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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A mesoscale study of coastal currents and upwelling off PeruEnfield, David B. 01 May 1970 (has links)
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
meter time series indicate that the longshore flow was poleward during
most of the study period, interrupted by a three day 'event' of
equatorward flow. The similarity of flow at all current meters indicates that the field of flow as quasi-barotropic. The depth, extent, and transport of poleward flow indicated by current meter time series
and geostrophic sections were similar to those described in the literature
for the Peru-Chile Undercurrent. The observations suggest
that this flow moved further offshore as equatorward flow appeared
over the shelf.
Power spectral analyses performed on current meter records
indicate the existence of semidiurnal tidal currents in the longshore
direction. The magnitude of these currents is estimated at 10% to
15% of period mean speeds.
Ten meter drogue displacements are compared with 25 m recorded
currents and with winds. The observations indicate that: the
drogues were affected by both the 25 m flow and the wind; the depth
of the wind drift layer was between 10 m and 25 m; the drogue displacements were in the sense expected from the Ekman model.
Vertical sections of sigma-t, oxygen, and nitrate indicate the
existence of conditions consistent with upwelling. Surface maps of
temperature, nitrate, and chlorophyll 'a' over the shelf are used to
define the horizontal field of upwelling and its variations in time.
The distributions suggest that upwelling existed throughout the period
and underwent temporal and spatial modulations in intensity. The
possibility of a causal mechanism between observed current and
upwelling variations is examined.
Vertical salinity sections indicated the presence of a weak salinity
minimum between the surface and 100 m. It is suggested that this
minimum manifests the remnants of a tongue of Subantarctic Water
embedded in a much larger mass of Equatorial Subsurface Water.
The occurrence of the minimum only in conjunction with poleward flow
suggests that the water was advected or mixed coastward somewhere
north of the area studied, was entrained in the Peru-Chile Undercurrent,
and was carried south again. / Graduation date: 1970
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The general circulation in the north Pacific Ocean referred to a variable reference surfaceMcAlister, William Bruce 18 May 1962 (has links)
Graduation date: 1962
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Observations and analysis of ocean currents above 250 meters off the Oregon coastMaughan, Paul M. 15 May 1963 (has links)
Graduation date: 1963
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Near-inertial motions off the Oregon coastAnderson, Iain 30 April 1982 (has links)
Nearly three months of current meter records from five moorings off
the Oregon coast taken between October 1977 and January 1978 were analyzed
for near-inertial motions. The moorings were located from the midshelf
out to the foot of the continental slope, spanning the continental
margin. All but two of the eleven current meters were continuously
below the mixed layer. For spectral analysis, the current observation
period was divided into two time periods, one with large amplitude
near-inertial motion (41.1 cm/sec maximum of the band-passed records)
throughout and the other with much less near-inertial energy. The
spectra of the current meter records showed between a 1 and 6% increase
in frequency of the near-inertial peak above f (= 0.0592 cph) in all
but three cases. The exceptions showed spectral peaks about 14% below
f and were linked to a Doppler shift. The period of large amplitude
near-inertial motion had diagonal coherence scales of over 450 meters
vertically and 115 kilometers horizontally. An east-west (cross-shelf)
wavelength of about 50 kilometers was estimated directly from the phase
differences between current meters with roughly horizontal separations.
The observed response of a current meter about 35 meters below
the mixed layer to sharp maxima in the wind stress was similar to that predicted by the Pollard and Millard (1970) model for wind forced
near-inertial motions in the surface mixed layer. The winds associated
with a series of atmospheric fronts were apparently responsible for
generating a 14-day period of large amplitude near-inertial motion
observed below the mixed layer. / Graduation date: 1982
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