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ScholarsArchive at Oregon State University
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We present an optical method (optical current meter) to measure the longshore
component of nearshore surface currents by measuring the alongshore drift of persistent
sea foam in the surf zone. The method uses short time series of video data...
2003-11-26 (iso8601)
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Recently, models for the onshore migration of nearshore sandbars were improved by including an empirical acceleration term in the sediment transport formulation (Hoefel and Elgar, 2003). Here, field observations of the fluid-sediment interface...
2006-03-04 (iso8601)
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Field observations of turbulence and sediment suspension in the nearshore wave bottom boundary layer obtained during the Duck94 field experiment on the North Caroline coast showed the generation of near-bed turbulence to be highly intermittent....
2006-04-27 (iso8601)
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A Regional Ocean Modeling System (ROMS) application for the coastal region of Kenya and Tanzania (0-10° S, 38.7-46.98° E) was developed with the aim of better resolving the circulation patterns in the coastal region that is poorly represented in...
2010-05-06T20:50:18Z (iso8601)
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Alongshore-separated time series of natural swash motions were obtained over a range of environmental conditions using a video technique. Although the frequency spectra and normalized wavenumber spectra for these motions were particularly bland,...
1999-06-15 (iso8601)
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Runup kinematics on a gently sloping natural beach are examined with detailed measurements from video images, resistance wires deployed at five elevations (between 5 and 25 cm) above and parallel to the beach face, and pressure sensors located in...
1995-03-15 (iso8601)
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Time and length scales of beach variability have been quantified using 16 years
of beach surveys sampled at the Army Corps of Engineers' Field Research Facility,
located on the U.S. Atlantic coast. Between 50% and 90% of the bathymetric...
1999-07-15 (iso8601)
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Four years of daily time exposure images from an embayed beach were examined to
study the spacing, persistence, and location preferences of rips in a natural rip channel
system. A total of 5271 rip channels was observed on 782 days. Occurrence...
2006 (iso8601)
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Sandbars are ubiquitous, yet not well understood
beach features that change their position and shape in
response to changing wave conditions. We propose and test
a simple empirical model consisting of two coupled linear
differential equations that...
2006 (iso8601)
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Several aspects of feedback mechanisms associated with surf zone sandbar
response have been characterized using bathymetric surveys, sampled approximately
monthly over a 16-year period at the Army Corps of Engineers' Field Research Facility
(North...
2001-01-15 (iso8601)
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Because of highly dissipative conditions and strong alongshore gradients in foreshore
beach morphology, wave run-up data collected along the central Oregon coast during
February 1996 stand in contrast to run-up data currently available in the...
2004 (iso8601)
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A study of swash zone sediment transport was conducted at Gleneden
Beach, Oregon during February 25-28, 1994. The data collected included suspended
sediment concentration (SSC), sea surface elevation, and velocity (initially 4 and 8
cm above the...
2000-07-15 (iso8601)
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The nonlinear dynamics of finite amplitude shear instabilities of
alongshore currents in the nearshore surf zone over barred beach topography are
studied using numerical experiments. These experiments extend the recent study
of Allen et al....
1998-08-15 (iso8601)
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The nonlinear dynamics of unstable alongshore currents in the nearshore
surf zone over variable barred beach topography are studied using numerical
experiments. These experiments extend the recent studies of Allen et al. [1996]
and Slnn et al....
2000-07-15 (iso8601)
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The temporal and spatial variability of crescentic sandbars is analyzed with hourly
long-term (months) video observations collected at four barred sites and are qualitatively
compared to the temporal and spatial variability predicted by hypotheses...
2004 (iso8601)
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The path of the Antarctic Polar Front (PF) is mapped using satellite sea surface temperature data from the NOAA/NASA Pathfinder program. The mean path and variability of the PF are strongly influenced by bathymetry. Meandering intensity is weaker...
1997-12-15 (iso8601)
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Helium isotopes are a robust geochemical tracer of a primordial mantle component in hot spot volcanism. The high ³He/⁴He (up to 35 RA, where RA is the atmospheric ³He/⁴He ratio of 1.39 X 10¯⁶) of some Hawaiian Island volcanism is perhaps the...
2004-12-31 (iso8601)
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As the Galápagos hot spot is approached from the west along the Galápagos Spreading Center there are systematic increases in crustal thickness and in the K/Ti, Nb/Zr, ³He/⁴He, H₂O, and Na₂O content of lavas recovered from the spreading axis. These...
2002-10-10 (iso8601)
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The submarine Amsterdam-St. Paul (ASP) Plateau, bisected by the Southeast Indian Ridge (SEIR), is a bathymetric high rising ~2 km above the surrounding seafloor that includes the islands of Amsterdam and St. Paul; this excess volcanism is...
2007-09-18 (iso8601)
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We have measured ³He/⁴He ratios and He and Ne concentrations on a suite of 24 basalt glasses from the neovolcanic zone of the Juan de Fuca Ridge (JdFR) from 44.6°N near the Blanco Transform up to 48.0°N on the Endeavour Segment. The helium isotope...
1993-09-03 (iso8601)
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Basalts from the four southernmost segments of the subducting Chile Ridge (numbered 1-4 stepping away from the trench) display large variations in Sr, Nd, Pb, and He isotope and trace element compositions. Klein and Karsten [1995] showed that...
1999-03-10 (iso8601)
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The Amsterdam-St. Paul Plateau is bisected by the intermediate-rate spreading Southeast Indian Ridge, and numerous geophysical and tectonic anomalies arise from the interactions of the Amsterdam-St. Paul hotspot and the spreading center. The plate...
2000-04-10 (iso8601)
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Hot spot–mid-ocean ridge interactions cause many of the largest structural and chemical anomalies in Earth’s ocean basins. Correlated geophysical and geochemical anomalies are widely explained by mantle plumes that deliver hot and compositionally...
2003-11-20 (iso8601)
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Currents and winds measured over the continental shelf and upper continental slope during the first
half of 1984 are analyzed to determine the character of the flow off central California (Point Conception
to San Francisco). The mean flow was...
1988-09-15 (iso8601)
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Seasonal variability of alongshore geostrophic velocity relative to 500 dbar is examined from 23 years
of hydrographic data along two sections off central California (one off Point Sur and the other off Point
Conception). The seasonal cycles are...
1984-05-20 (iso8601)
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