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Dissertations, Theses, and Masters Projects

2008

Earth Sciences

Articles 1 - 8 of 8

Full-Text Articles in Physical Sciences and Mathematics

Variability In Geologic Framework And Shoreline Change: Assateague And Wallops Islands, Eastern Shore Of Virginia, Geoffrey L. Wikel Jan 2008

Variability In Geologic Framework And Shoreline Change: Assateague And Wallops Islands, Eastern Shore Of Virginia, Geoffrey L. Wikel

Dissertations, Theses, and Masters Projects

No abstract provided.


Sediment Transport And Erodibility In The York River Estuary: A Model Study, Jeffrey Paul Rinehimer Jan 2008

Sediment Transport And Erodibility In The York River Estuary: A Model Study, Jeffrey Paul Rinehimer

Dissertations, Theses, and Masters Projects

A cohesive sediment bed model was implemented in the Community Sediment Transport Modeling System (CSTMS) to examine processes influencing sediment erodibility and suspended sediment concentrations. Estimates of eroded mass from the sediment bed model were calibrated and verified with erosion chamber measurements from the York River, Virginia, a tidally-dominated environment. A constant erosion rate parameter combined with depth-varying critical shear stress was sufficient to model erosion observations of depth-limited sediment cores. Sensitivity of total eroded mass to seasonal variations in erodibility and changes in consolidation time scale was evaluated during spring-neap variations in bottom stresses. Differences were greatest during spring …


Controls On Continental Shelf Stratigraphy: Waiapu River, New Zealand, Heidi M. Wadman Jan 2008

Controls On Continental Shelf Stratigraphy: Waiapu River, New Zealand, Heidi M. Wadman

Dissertations, Theses, and Masters Projects

A quantitative understanding of the processes controlling sediment transport and deposition across the land/sea interface is crucial to linking terrestrial and marine environments and understanding the formation of marine stratigraphy. The nature and distribution of terrestrial-derived sediment preserved in shelf stratigraphy in turn provides insight into the complex linkages inherent in source-to-sink sediment dynamics. Located inboard of an actively subducting plate boundary and characterized by one of the highest sediment yields in the world, the open-shelf setting off of the Waiapu River in New Zealand presents an excellent location to improve our understanding of the factors controlling the formation of …


Nearshore Morphology And Lithology: Links To Framework Geology And Shoreline Change, Jennifer L. Miselis Jan 2008

Nearshore Morphology And Lithology: Links To Framework Geology And Shoreline Change, Jennifer L. Miselis

Dissertations, Theses, and Masters Projects

Despite evidence of the geologic and morphologic complexity of inner shelves worldwide, there is a paucity of observations from the nearshore, inhibiting direct comparison of these factors to coastal change. Using geophysical instruments to characterize the geology of the nearshore, this research focuses on the relationships between nearshore stratigraphy, sediment heterogeneity, shoreface morphology and shoreline behavior. While generally not considered in engineering models of shoreline evolution, these factors influence nearshore processes. Overall, the findings presented highlight the importance of nearshore geology, both at the seafloor and underlying it, in contributing to modem sediment transport processes affecting beaches. Shallow, sub-seafloor geology …


Community Dynamics In Submersed Aquatic Vegetation: Intermediate Consumers As Mediators Of Environmental Change, James G. Douglass Jan 2008

Community Dynamics In Submersed Aquatic Vegetation: Intermediate Consumers As Mediators Of Environmental Change, James G. Douglass

Dissertations, Theses, and Masters Projects

Natural ecosystems are strongly affected by changes in resource supply (bottom-up forces) and by changes in upper trophic levels (top-down forces). The extent to which these processes impact a system depends largely on the responses of organisms at middle trophic levels. In seagrass beds, a group of mid-level consumers known as mesograzers form a critical link in the chain of impact, connecting seagrass and epiphytic algae with predatory fishes and crustaceans. I observed dramatic seasonal and interannual changes in mesograzer abundance and species composition in eelgrass (Zostera marina) beds of lower Chesapeake Bay, Virginia, and endeavored to explain the top-down …


Factors Controlling Tidal Flat Morphology In South San Francisco Bay Between The 1890s And 2005, Joshua Alexander Bearman Jan 2008

Factors Controlling Tidal Flat Morphology In South San Francisco Bay Between The 1890s And 2005, Joshua Alexander Bearman

Dissertations, Theses, and Masters Projects

There is currently a project underway to restore many of the man-made salt ponds along the shores of South San Francisco Bay (SSFB) back to tidal marsh, potentially reestablishing these areas as sinks for SSFB sediments. While there have been recent studies examining the evolution of newly restored marsh areas in SSFB, there have been no recent projects focusing on the expected response of valuable tidal flat environments adjacent to the restored marshes. To help fill this void, this project seeks to characterize SSFB tidal flat morphodynamics, both spatially and temporally, through examination of historic morphologic variability and change along …


A Modern Sediment Budget For The Continental Shelf Off The Waipaoa River, New Zealand, Andrea J. Miller Jan 2008

A Modern Sediment Budget For The Continental Shelf Off The Waipaoa River, New Zealand, Andrea J. Miller

Dissertations, Theses, and Masters Projects

No abstract provided.


Recent Sedimentation Patterns And Facies Distribution On The Waipaoa River Shelf, N.Z, Lila Eve Rose Jan 2008

Recent Sedimentation Patterns And Facies Distribution On The Waipaoa River Shelf, N.Z, Lila Eve Rose

Dissertations, Theses, and Masters Projects

No abstract provided.