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Articles 1 - 12 of 12
Full-Text Articles in Physical Sciences and Mathematics
Hyperpycnal Discharge Of Fluvial Sediment To The Ocean: Impact Of Super‐Typhoon Herb (1996) On Taiwanese Rivers, John D. Milliman, Shuh-Ji Kao
Hyperpycnal Discharge Of Fluvial Sediment To The Ocean: Impact Of Super‐Typhoon Herb (1996) On Taiwanese Rivers, John D. Milliman, Shuh-Ji Kao
VIMS Articles
Hyperpycnal events (when suspended sediment concentrations exceed 40 g/L) occur in small‐ and medium‐sized rivers throughout the world but are particularly common in Taiwan; they are often related to landslides or debris flows initiated and transported by typhoon floods. Super‐Typhoon Herb, which swept across Taiwan on July 31–August 2, 1996, triggered floods and landslides throughout the southern part of the island. Sediment concentrations in at least seven rivers (Taan, Choshui, Pachang, Erhjen, Tsengwen, Kaoping, and Peinan) approached or exceeded 40 g/L. Calculated sediment discharged from nine rivers (these seven as well as the Wu and Houlung, neither of which apparently …
Effects Of Sunlight On Decomposition Of Estuarine Dissolved Organic C, N And P And Bacterial Metabolism, Sl Mccallister, Je Bauer, J Kelly, Hw Ducklow
Effects Of Sunlight On Decomposition Of Estuarine Dissolved Organic C, N And P And Bacterial Metabolism, Sl Mccallister, Je Bauer, J Kelly, Hw Ducklow
VIMS Articles
The effects of natural sunlight and microbial decomposition on DOC, DON, and DOP were investigated along the salinity gradient of a temperate coastal plain estuary. The impact of sunlight-irradiated DOM on bacterial properties (bacterial abundance, production, bacterial growth efficiency [BGE]) was also followed. Surface-water light levels resulted in no detectable abiotic production of NH4+ or PO43- or loss of DOC. Bacterial decomposition of DOC was enhanced by 27 to 200 % in irradiated relative to dark treatments. There was, however, no corresponding enhancement in DON and DOP remineralization. Significant differences in bacterial decomposition of light-exposed DOC were frequently observed following …
Radionuclide And Biomarker Proxies Of Past Ocean Circulation And Productivity In The Arabian Sea, A Pourmand, F Marcantonio, Ts Bianchi, Elizabeth A. Canuel, Ej Waterson
Radionuclide And Biomarker Proxies Of Past Ocean Circulation And Productivity In The Arabian Sea, A Pourmand, F Marcantonio, Ts Bianchi, Elizabeth A. Canuel, Ej Waterson
VIMS Articles
We present new excess Pa-231/Th-230 activity ratios and lipid biomarker results from northeastern Arabian Sea sediments (core 93KL) spanning the past 50 ka in an effort to constrain further the relationship between climate at low and high latitudes. Pa-231/Th-230 activity ratios are maintained at values significantly higher than the water-column production ratio of 0.093. Average Pa-231/Th-230 activity ratios are lower during the last glacial period than during the Holocene. The lowest Pa-231/Th-230 activity ratios coincide with the timing of Heinrich Events 1-5. Profiles of lipid biomarker fluxes and Pa-231/Th-230 activity ratios from 32 to 12 ka show similar patterns, suggesting …
Input Of Particulate Organic And Dissolved Inorganic Carbon From The Amazon To The Atlantic Ocean, Erm Druffel, Je Bauer, S Griffin
Input Of Particulate Organic And Dissolved Inorganic Carbon From The Amazon To The Atlantic Ocean, Erm Druffel, Je Bauer, S Griffin
VIMS Articles
We report concentrations and isotope measurements (radiocarbon and stable carbon) of dissolved inorganic carbon (DIC) and suspended particulate organic carbon (POC) in waters collected from the mouth of the Amazon River and the North Brazil Current. Samples were collected in November 1991, when the Amazon hydrograph was at its annual minimum and the North Brazil Current had retroflected into the equatorial North Atlantic. The DIC D 14 C results revealed postbomb carbon in river and ocean waters, with slightly higher values at the river mouth. The low DIC delta(13)C signature of the river end-member (-11%) demonstrates that about half of …
Planar Oxides As A Novel Approach To Metal Ion Sorption Studies: From The Lab To The Field, Christine F. Conrad
Planar Oxides As A Novel Approach To Metal Ion Sorption Studies: From The Lab To The Field, Christine F. Conrad
Dissertations, Theses, and Masters Projects
The purpose of this work is to investigate the use of planar oxides as tools for metal ion sorption studies that can be used in both laboratory and field settings. to do this, a three-step approach was used. In the first step, the reactivities of the planar gamma-Al2O3 surfaces relative to pure phase gamma alumina was investigated through Pb(II) sorption studies. The relative quantitative uptake of Pb(II) on the planar gamma alumina was found to be comparable to that on the bulk. XAS analysis showed that the coordination geometry and local binding environment of the Pb(II) complexes were similar on …
Sources Of Sedimentary Organic Matter In The Mississippi River And Adjacent Gulf Of Mexico, Elizabeth J. Waterson
Sources Of Sedimentary Organic Matter In The Mississippi River And Adjacent Gulf Of Mexico, Elizabeth J. Waterson
Dissertations, Theses, and Masters Projects
The development of accurate carbon budgets, as well as global climate models with predictive capabilities, requires an understanding of the delivery and fate of terrigenous carbon in the environment. Understanding the extent to which estuarine and continental shelf processes alter carbon transfer between marine and terrestrial systems, including estimates of organic matter accumulation in coastal sediments, is poorly known. Organic carbon and nutrients exported to the adjacent Gulf of Mexico by the Mississippi River are influenced by biological and physical processes including remineralization, hydrodynamic sorting, seabed mixing and bioturbation, and burial. These complex processes make it difficult to know the …
Hypoxia In Shallow Coastal Waters: A Case Study In Onancock Creek, Virginia, Taiping Wang
Hypoxia In Shallow Coastal Waters: A Case Study In Onancock Creek, Virginia, Taiping Wang
Dissertations, Theses, and Masters Projects
No abstract provided.
Linking Framework Geology And Nearshore Morphology: Correlation Of Paleo-Channels With Shore-Oblique Sandbars And Gravel Outcrops, A. Grace Browder
Linking Framework Geology And Nearshore Morphology: Correlation Of Paleo-Channels With Shore-Oblique Sandbars And Gravel Outcrops, A. Grace Browder
Dissertations, Theses, and Masters Projects
No abstract provided.
Little Creek Naval Amphibious Base Chesapeake Bay Shoreline, C. Scott Hardaway Jr., Donna A. Milligan, George R. Thomas, Linda M. Meneghini
Little Creek Naval Amphibious Base Chesapeake Bay Shoreline, C. Scott Hardaway Jr., Donna A. Milligan, George R. Thomas, Linda M. Meneghini
Reports
Little Creek Naval Amphibious Base (NAB) is located in Virginia Beach, Virginia. It’s shoreline along the southern Chesapeake Bay extends from Little Creek Inlet eastward approximately 1.5 miles to the NAB’s eastern boundary. In 1997, a study and report entitled “LITTLE CREEK NAVAL AMPHIBIOUS BASE, CHESAPEAKE BAY SHORELINE, SHORELINE MANAGEMENT PLAN and OFFICER’S BEACH SHORE PROTECTION EVALUATION” was produced by VIMS’s Shoreline Studies Program (Hardaway et al., 1997). The purpose of that report was to assess the rates and patterns of beach change along the Chesapeake Bay shoreline at Little Creek NAB in order to develop a shoreline management plan, …
Iron And Carbon Limitation Of Prokaryotic Growth In The Ocean, Jacques L. Oliver
Iron And Carbon Limitation Of Prokaryotic Growth In The Ocean, Jacques L. Oliver
Dissertations, Theses, and Masters Projects
Studies were undertaken to examine the roles of iron and carbon in modulating prokaryotic growth in the ocean. The context of the first study was an open-open iron fertilization experiment in the high nutrient, low chlorophyll (HNLC) regime in the Southern Ocean. The context of the second study was the oligotrophic, iron-replete, and organic carbon-limited northwest Sargasso Sea. Experimental sea water cultures were amended with an iron chelator, desferrioxamine B (DFOB), and other nutrients to examine the effects of iron and carbon limitation on growth. In the first study prokaryotic abundance, carbon production, and growth rate increased in response to …
Simulation Of Turbidity Maximums In The York River, Virginia, Jae-Il Kwon
Simulation Of Turbidity Maximums In The York River, Virginia, Jae-Il Kwon
Dissertations, Theses, and Masters Projects
Two of the most important processes in cohesive sediment transport, erosion rate and settling velocity, were the focus of this study. Settling velocities were estimated by the Owen tube method and the acoustic Doppler velocimeter (ADV) method. A novel erosion model, namely a constant erosion rate model, was implemented in a three-dimensional hydrodynamic eutrophication model (HEM-3D) to simulate the turbidity maximums in the York River system, Virginia. Two one-month periods of model simulations were conducted to mimic typical dry (November--December, 2001) and wet (March--April, 2002) seasons. In order to have enough data to verify the model, four slack water surveys …
Shore-Oblique Bars, Nearshore Gravel Outcrops, And Their Correlation To Shoreline Change, Courtney A. Schupp
Shore-Oblique Bars, Nearshore Gravel Outcrops, And Their Correlation To Shoreline Change, Courtney A. Schupp
Dissertations, Theses, and Masters Projects
No abstract provided.