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Full-Text Articles in Physical Sciences and Mathematics

Inferring Tidal Wetland Stability From Channel Sediment Fluxes: Observations And A Conceptual Model, Nk Ganju, Nj Nidzieko, Matthew L. Kirwan Dec 2013

Inferring Tidal Wetland Stability From Channel Sediment Fluxes: Observations And A Conceptual Model, Nk Ganju, Nj Nidzieko, Matthew L. Kirwan

VIMS Articles

Anthropogenic and climatic forces have modified the geomorphology of tidal wetlands over a range of timescales. Changes in land use, sediment supply, river flow, storminess, and sea level alter the layout of tidal channels, intertidal flats, and marsh plains; these elements define wetland complexes. Diagnostically, measurements of net sediment fluxes through tidal channels are high-temporal resolution, spatially integrated quantities that indicate (1) whether a complex is stable over seasonal timescales and (2) what mechanisms are leading to that state. We estimated sediment fluxes through tidal channels draining wetland complexes on the Blackwater and Transquaking Rivers, Maryland, USA. While the Blackwater …


Holocene Sedimentation On The Lanyang Plain And Adjacent Continental Shelf, Northwestern Taiwan, Chia-Yu Wu Jan 2013

Holocene Sedimentation On The Lanyang Plain And Adjacent Continental Shelf, Northwestern Taiwan, Chia-Yu Wu

Dissertations, Theses, and Masters Projects

The Lanyang Plain, along the northeastern Taiwan orogen, provides an excellent example of the tectonic and climatic controls on erosion and subsequent riverine sediment supply to the coastal ocean and deep sea. 12 deep borings on the Lanyang Plain and 2 long cores in Southern Okinawa Trough (MD12403, ODP1202), together with high-resolution seismic data on Ilan Shelf, provide a good record of the depositional history during Holocene, in both on-land and offshore areas. Based on these data, we find the sediment thickness reaches 216 m in Lanyang Plain, and the average sediment rate is estimated to be 3.6 Mt/yr - …


Composition, Sources, And Age Of Dissolved And Particulate Organic Matter In The Delaware River And Estuary, Hadley Allaben Mcintosh Jan 2013

Composition, Sources, And Age Of Dissolved And Particulate Organic Matter In The Delaware River And Estuary, Hadley Allaben Mcintosh

Dissertations, Theses, and Masters Projects

Estuaries are important sites of organic matter (OM) transformation, exchange, and burial but remain one of the least understood regions in the global carbon cycle. The carbon cycle within these regions is complex due to strong gradients in biological and physical processes, and increasing anthropogenic impacts. This is further complicated by the many sources of particulate and dissolved organic matter (OM) in estuaries, including materials derived from terrestrial and anthropogenic sources as well as aquatic and marine primary production. This study combined lipid biomarker analyses with stable and radiocarbon signatures of lipids and source-specific biomarkers to better understand the sources …


Application Of Acoustics And Optics For The Characterization Of Suspended Particulate Matter Within An Estuarine Observing System, Grace M. Cartwright Jan 2013

Application Of Acoustics And Optics For The Characterization Of Suspended Particulate Matter Within An Estuarine Observing System, Grace M. Cartwright

Dissertations, Theses, and Masters Projects

As part of this dissertation work, a long term observing station at Clay Bank on the York River in Virginia has been established and maintained since 2006, and was used to gain a better understanding of sediment processes in a muddy estuary and in muddy coastal environments in general. While data from this NSF-funded Multi-Disciplinary Benthic Exchange Dynamic (MUDBED) observing system has and will be used by other students for this general purpose, this dissertation focuses specifically on better understanding and interpretation of the data collected by key instrumentation regularly deployed at the observing station, especially the acoustic Doppler velocimeter …


Acoustic And Sedimentological Investigations Of Seabed Conditions And Related Bio-Geological Parameters In A Tidally Energetic, Fine-Grained Environment: York River Estuary, Virginia, Lindsey M. Kraatz Jan 2013

Acoustic And Sedimentological Investigations Of Seabed Conditions And Related Bio-Geological Parameters In A Tidally Energetic, Fine-Grained Environment: York River Estuary, Virginia, Lindsey M. Kraatz

Dissertations, Theses, and Masters Projects

The transport and fate of fine-grained sediments is a critical factor affecting the physical, chemical, and biological health of estuaries, coastal embayments, riverine, lacustrine, and continental shelf environments. A geophysical and sedimentological study of the York River as a part of the NSF Multi-disciplinary Benthic Exchange Dynamics (MUDBED) project was conducted to determine: 1) the primary drivers of sediment erodibility within a fine-grained system, 2) if these drivers can be accurately measured through sedimentological and acoustic information, and 3) the spatial and seasonal variability of erosion within the estuary. Previous studies indicate that increased erodibility within the York River Estuary …


Seasonal Nitrogen Uptake And Regeneration In The Water Column And Sea-Ice Of The Western Coastal Arctic, Steven E. Baer Jan 2013

Seasonal Nitrogen Uptake And Regeneration In The Water Column And Sea-Ice Of The Western Coastal Arctic, Steven E. Baer

Dissertations, Theses, and Masters Projects

The logistical difficulties of research in extremely low temperatures and lack of access to the Arctic have meant that there is a historic dearth of knowledge of coastal Arctic biogeochemistry, especially during winter when sea ice is present. Recent observations, however, indicate that the Arctic is changing rapidly. Changes include increased temperatures, decreased extent and volume of sea ice, and increased freshwater inputs. How these changes influence biogeochemical cycles is an open question, especially in the highly productive coastal regions of the Chukchi Sea. Here I present nitrogen (N) uptake and regeneration rates for phytoplankton and bacteria measured in the …


Submarine Groundwater Discharge To The York River Estuary: Quantifying Groundwater Flux And Potential For Biogeochemical Cycling, Jenna Lynn Luek Jan 2013

Submarine Groundwater Discharge To The York River Estuary: Quantifying Groundwater Flux And Potential For Biogeochemical Cycling, Jenna Lynn Luek

Dissertations, Theses, and Masters Projects

No abstract provided.


Regression Modeling Of The North East Atlantic Spring Bloom Suggests Previously Unrecognized Biological Roles For V And Mo, Nj Klein, Aj Beck, Da Hutchins, Sa Sanudo-Wilhelmy Jan 2013

Regression Modeling Of The North East Atlantic Spring Bloom Suggests Previously Unrecognized Biological Roles For V And Mo, Nj Klein, Aj Beck, Da Hutchins, Sa Sanudo-Wilhelmy

VIMS Articles

In order to identify the biogeochemical parameters controlling pCO(2), total chlorophyll a, and dimethyl sulfide (DMS) concentrations during the North East Atlantic Spring Bloom (NASB), we used previously unpublished particulate and dissolved elemental concentrations to construct several linear regression models; first by hypothesis testing, and then with exhaustive stepwise linear regression followed by leave-one-out cross-validation. The field data was obtained along a latitudinal transect from the Azores Islands to the North Atlantic, and best-fit models (determined by lowest predictive error) of up to three variables are presented. Total chlorophyll a is predicted best by biomass (POC, PON) parameters and by …