Index Catalog // ScholarsArchive@OSU

Creator:: Duncan, Robert A.
Abstract:: 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 total fusion and incremental heating ages show an increase in seamount construction age from southeast to...
Resource Type:: Article
Full Text:: dredged volcanic rocks at the Woods Hole Oceanographic Institution (courtesy of G. Thompson). These

Creator:: Duncan, Robert A.
Abstract:: 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 migrated with time from the northern and southern ends toward the center, near...
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Full Text:: CAPTURED ISLAND CHAIN IN THE COAST RANGE OF OREGON AND WASHINGTON Robert A. Duncan School of

Creator:: Miller, Robert N.
Abstract:: A series of observing system simulation experiments (OSSE) is performed on a simulated data set which was designed to mimic the wind-forced response of the tropical Pacific ocean. This data set was constructed by adding random perturbations to the FSU monthly mean pseudostress anomaly data. These perturbed pseudostress anomaly fields...
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Full Text:: ROBERT N. MILLER College of Oceanography, Oregon State University, Corvallis A series of observing

Creator:: VanLaningham, Sam, Duncan, Robert A., and Pisias, Nicklas G.
Abstract:: We use Ar-40-Ar-39 incremental heating to fingerprint bulk fluvial sediment entering the northeast Pacific Ocean, with the long-term intent of tracking sediment source and transport changes from the terrestrial system to the marine environment through time. We show reproducible age spectra from individual rivers accounting for the majority of sediment...
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Full Text:: ,1 Robert A. Duncan,1 and Nicklas G. Pisias1 Received 23 May 2006; accepted 8 September 2006

Creator:: Splinter, Kristen D., Holman, Robert A., and Plant, Nathaniel G.
Abstract:: A nonlinear model is developed to study the time‐dependent relationship between the alongshore variability of a sandbar, a(t), and alongshore‐averaged sandbar position, xc(t). Sediment transport equations are derived from energetics‐based formulations. A link between this continuous physical representation and a parametric form describing the migration of sandbars of constant shape...
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Full Text:: migration and 2DH evolution Kristen D. Splinter,1,2 Robert A. Holman,1 and Nathaniel G. Plant3 Received 29

Creator:: Davis, Michael G., Harris, Robert N., and Chapman, David S.
Abstract:: Borehole temperature profiles provide a record of ground surface temperature (GST) change at the decadal to centennial time scale. GST histories reconstructed from boreholes are particularly useful in climate reconstruction if changes in GST and surface air temperature (SAT) are effectively coupled at decadal and longer time periods and it...
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Full Text:: scale Michael G. Davis,1 Robert N. Harris,2 and David S. Chapman1 Received 10 August 2009; revised 11

Creator:: Bartlett, Marshall G., Chapman, David S., and Harris, Robert N.
Abstract:: Changes in snow’s influence on surface ground temperature (SGT) could create a bias in the borehole temperature record of climate change. Using a snow-ground thermal model which predicts changes in the mean annual offset between SGT and surface air temperature (SAT), we calculate the response of SGT to changes in...
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Full Text:: , 1950–2002 Marshall G. Bartlett, David S. Chapman, and Robert N. Harris Department of Geology and

Creator:: Harris, Robert N., Bartlett, Marshall G., and Chapman, David S.
Abstract:: [1] Borehole temperature-depth profiles contain a record of surface ground temperature (SGT) changes with time and complement surface air temperature (SAT) analysis to infer climate change over multiple centuries. Ground temperatures are generally warmer than air temperatures due to solar radiation effects in the summer and the insulating effect of...
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Full Text:: change Marshall G. Bartlett, David S. Chapman, and Robert N. Harris Department of Geology and Geophysics

Creator:: Holman, Robert A., Symonds, G., Thornton, E. B., and Ranasinghe, R.
Abstract:: 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 statistics showed no evidence of the preferred location pattern...
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Full Text:: beach R. A. Holman,1 G. Symonds,2,3 E. B. Thornton,4 and R. Ranasinghe5 Received 15 March 2005

Creator:: Pyle, D. G., Christie, David M., Mahoney, J. J., and Duncan, Robert A.
Abstract:: Within the Australian-Antarctic Discordance (AAD), a boundary exists between isotopically defined “Pacific-type” and “Indian-type” mid-ocean ridge basalt (MORB) erupted along the Southeast Indian Ridge (SEIR). This boundary has migrated westward beneath the easternmost AAD spreading segment at a minimum rate of 25 mm/yr since 4 Ma; however, its long-term history...
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Full Text:: seafloor D. G. Pyle and D. M. Christie College of Oceanic and Atmospheric Sciences, Oregon State

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