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ScholarsArchive at Oregon State University
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The Marquesas archipelago is a short. NW-SE trending cluster of islands and seamounts that formed as a
result of volcanic activity over a weak hotspot. This volcanic chain lies at the northern margin of a broad
region of warm and compositionally...
1993-10-10 (iso8601)
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Determination of reliable crystallization ages by
K-Ar methods for young (<1 Ma), fresh basalts from the
seafloor has been frustrated by several effects. The small
amounts of radiogenic ⁴⁰Ar developed over these timescales in
such low-K rocks are...
1994-09-01 (iso8601)
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Persistent, long-lived, stationary sites of
excessive mantle melting are called hotspots. Hotspots
leave volcanic trails on lithospheric plates passing across
them. The global constellation of fixed hotspots thus
forms a convenient frame of...
1991 (iso8601)
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K-Ar and ⁴⁰Ar-³⁹Ar geochronologic
data reveal the Paleocene to Eocene eruptive
history of volcanic centers which produced the
basaltic basement rocks of the Coast Range of
Oregon and Washington. Volcanism was short
lived at each center and...
1982-12-10 (iso8601)
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Radiometric ages (K-Ar and ⁴⁰Ar-
³⁹Ar methods) have been determined on dredged
volcanic rocks from seven of the New England
Seamounts, a prominent northwest-southeast trending
volcanic lineament in the northwestern
Atlantic Ocean. The ⁴⁰Ar-³⁹Ar...
1984-11-10 (iso8601)
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Lithospheric cracking by remotely applied stresses or thermoelastic stresses has been
suggested to be the mechanism responsible for the formation of intraplate volcanic ridges
in the Pacific that clearly do not form above fixed hot spots. As part...
2006-11-25 (iso8601)
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Lavas of the Rano Rahi seamount field define a Nd-Pb-Sr isotopic array that connects, and substantially
overlaps, the arrays of the nearby East Pacific Rise axis and 5.6–28 Ma lavas of the Pukapuka ridge
system, situated between the seamount field...
2006-03-28 (iso8601)
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Analysis of the Bakota basalts exposed in the Zambezi Gorge some 40 km east of Victoria Falls characterizes them as high Fe, moderately high Ti, and low K, P, and Zr tholeiites. The ⁴⁰Ar-³⁹Ar age determinations are tightly clustered at 180-179 Ma....
2001-02-12 (iso8601)
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Theoretical scattering computations are performed on a phytoplankton model consisting of three
concentric spheres. The outer sphere represents the wall, membrane, or frustule and is assigned a
relatively high index of refraction with no...
1992 (iso8601)
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The relationships between beam attenuation, absorption, suspended particle concentration, size distribution and pigment content are examined for a region where the particle concentration and pigment maxima are widely separated. Mie scattering...
1990-11-15 (iso8601)
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Particle size distributions (8-105-μm diameter), chlorophyll a, and particulate carbon
were measured off the Oregon coast during July 1973. The particle counts were transformed
to volume concentration and then subjected to characteristic vector...
1975-09 (iso8601)
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Observations made during October and December 1971 on the Yaloc 71 Cruise of Oregon State University indicate the presence of the Cromwell Current on the east side of the Galapagos Islands. Light scattering, particle size distribution, nutrients,...
1973-11-20 (iso8601)
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One hundred and seventy pairs of temperature and light transmission profiles were obtained by simultaneous conductivity-temperature-depth (CTD) and light transmissometer casts in three cruises on the R/V Yaquina over the continental shelf off...
1977-09-20 (iso8601)
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Two separate time series observations of light transmission in the bottom water on the Continental
Rise off Nova Scotia show fluctuations of light transmission in a wide range, 0-50% transmission at λ
= 660 nm. The range corresponds approximately...
1983-05-20 (iso8601)
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Two distinct kinds of particle maxima (nepheloid layers) were observed off Oregon in November 1977
and off Washington in October 1978 by an in situ light transmissometer: one in the thermocline in the
euphotic zone and the other at intermediate...
1980-11-20 (iso8601)
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We looked at the influence of temperature
and salinity on the absorption coefficient of
water with emphasis on the red and near-IR portions
of the spectrum. The absorption coefficient of pure
water was found to have a strong dependence on...
1993 (iso8601)
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In the spring of 1992 an optical closure experiment was conducted at Lake
Pend Oreille, Idaho. A primary objective of the experiment was to compare techniques
for the measurement of the spectral absorption coefficient and other inherent optical...
1995-07-15 (iso8601)
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A fundamental relationship of inherent optical properties (IOP) is that the
beam attenuation coefficient is the sum of the volume absorption and scattering
coefficients (c = a + b). A relative calibration of a set of instruments can be provided...
1995-07-15 (iso8601)
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Suspended matter in Astoria canyon was monitored by means of an in situ nephelometer and by means of light-scattering and particle concentration measurements performed aboard ship on water samples. Nephelometer profiles obtained along the axis of...
1974-10-20 (iso8601)
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Profiles of light transmission versus depth have been studied in the region of the Scotian Rise of the
North Atlantic at bottom depths between 4900 and 5000 m. A component model has been developed
and consists of three components of transmission...
1982-11-20 (iso8601)
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Measurements of total irradiance versus depth and beam transmission versus depth were made at
stations near shore along the west coast of the North and South American continents. The water types at
each station were optically classified according...
1979-01-20 (iso8601)
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The distribution of suspended matter in the Panama basin was determined by means of
light scattering and Coulter counter measurements on water samples collected at 50 hydrographic
stations. The observed distribution indicates three probable...
1973-10-20 (iso8601)
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Monte Carlo simulations are carried out to determine the error in the
inversion of backscattering from remotely sensed reflectance when geometrical shape
factors of the light field are assumed to be unity. The results show that error in...
1995-07-15 (iso8601)
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The reflectance of the bottom is of importance when interpreting optical data in shallow water. Closure studies
of radiative transfer, interpretation of laser line scanner data, lidar, and remote sensing in shallow waters require
understanding of...
2003 (iso8601)
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Light transmission profiles have been used to study the optical properties of the suspended particles which are characteristic of the area of the Scotian Rise in the North Atlantic Ocean. This area is typified by very strong bottom currents and a...
1983-09-20 (iso8601)
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