This investigation is an exploration of the use of inherent optical properties towards further elucidation of coastal circulation processes occurring on the continental shelf and slope in the Middle Atlantic Bight, south of Cape Cod Massachusetts, during 14-Aug to 1-Sep 1996 and 25-Apr to 15-May 1997. Assessing the possibility of...
Marine bacterioplankton play an important role in global elemental cycles because they return carbon dioxide and nutrients to the biosphere as they reduce organic matter. Furthermore, marine bacterioplankton are not uniformly active, and subpopulations of the in situ community may be more or less active at any given time. Defining...
A linearized model with two vertical modes has been developed to understand observed characteristics of monthly variability in the Equatorial Pacific from TOPEX/POSEIDON measurements of Sea Surface Height (SSH). The 2-mode model is obtained from an equatorial beta plane model that has been linearized about a geostrophically balanced mean flow...
This thesis describes the development of a rare earth element (REE) proxy for paleoceanographic studies of climate change. This work was done in three stages with the goal: (1) To develop a cleaning method that overcomes the problems of REE readsorption; (2) To measure pore water REEs for evaluation of...
This thesis investigates lithogenic sediments on the Siberian Arctic shelf, their sources, modes of dispersal, transport pathways and post-depositional diagenetic alteration. Working with cores collected from the Chukchi, East Siberian and Laptev Seas, we characterize surface-sediment elemental chemistry and clay mineralogy. We identify five regions with endmember sedimentary compositions. Comparing...
The objectives of this dissertation were to describe the complex oceanographic conditions around the Galápagos Archipelago (eastern equatorial Pacific), their seasonal variability, and their effects on patterns of cetacean occurrence. The physical and ecological factors leading to a plume of high phytoplankton biomass in the wake of the Galápagos were...
Precise in situ measurement of the spectral absorption and scattering coefficients in several regions has revealed patterns in the distribution of the inherent optical properties on spatial scales that were previously unobtainable. The precision of the measurements was found to be consistent and unbiased across a variety of oceanic regimes...
Tillamook Bay is the second largest estuary on the Oregon coast, and concerns have been raised whether human induced impacts have been responsible for the perceived increase in sedimentation rates during the past century. Major land-use practices within the five watersheds of the Bay include logging, forest fires, the construction...
Dissolved silicic acid (Si(OH)4) and biogenic silica (BSiO2) concentrations were measured on four different cruises in the Southern Ocean along 1700 W from late October 1997 to mid-March 1998. These data were used to construct a vertically integrated Si budget in the surface layer from 58° to 68° S. Throughout...
Here we investigate the relationships between modern foraminiferal assemblages from Atlantic and Pacific surface sediment samples and multiple environmental properties including water column and preservation variables using Canonical Correspondence Analysis (CCA). CCA finds two fauna] dimensions that are highly correlated to the environmental variables included in the analysis, and then...
Planktonic foraminiferal faunal assemblages were used to estimate sea-surface temperatures (SST) in the southeast Pacific Ocean during the Last Glacial Maximum (LGM) and off the coast of Peru over the last 150,000 years. Temperatures along the eastern boundary of South America were 6-8° C cooler during the LGM than at...
During the last 15 years, numerous geophysical surveys and geological sampling and coring expeditions have helped to characterize the tectonic setting, subsurface stratigraphy, and gas hydrate occurrence and abundance within the region of the accretionary wedge surrounding Hydrate Ridge. Because of these investigations, Hydrate Ridge has developed as an international...
This thesis investigates the behavior of major inorganic nutrients (P, N, Si), trace metals (Mn, Fe), and alkaline-earth metals (Ba) within Tillamook Bay over seasonal cycles and under a range of river discharge conditions from October 1997 through December 1999. Located in the Pacific Northwest region, Tillamook Bay is an...
The Oregon continental shelf waters are typically characterized by four to five major upwelling events that occur between May and October. The upwelled water is rich in nutrients, which fuels an increase in phytoplankton biomass. The onset of El Nino, however, can disrupt the normal physical processes along the Oregon...
Inner-shelf circulation and mechanisms of across-shelf transport of water masses were examined using seven years of observations collected by the Partnership for Interdisciplinary Studies of Coastal Oceans (PISCO) program, a long-term monitoring effort along the central Oregon coast. Since 1998, moored velocity and hydrographic measurements have been obtained during the...
An empirical statistical model is developed that relates the non-tidal motion of the ocean surface currents off the Oregon coast to forecasts of the coastal winds. The empirical statistical model is then used to produce predictions of the surface currents that are evaluated for their agreement with measured currents. Measurements...
