Resuspension events and seabed dynamics in the Neuse River Estuary, NC / by Sophia C. Dillard.
| Author/creator | Dillard, Sophia C. author. |
| Other author | Walsh, J. P. (John Patrick), 1973- degree supervisor. |
| Other author | Corbett, D. Reide (David Reide), 1971- degree supervisor. |
| Other author | East Carolina University. Department of Geological Sciences. |
| Format | Theses and dissertations |
| Production | 2008. |
| Description | xvi, 131 leaves : illustrations (some color), maps (some color) ; 29 cm |
| Supplemental Content | Access via ScholarShip |
| Subjects |
| Summary | The Neuse River Estuary, NC (NRE) is commonly affected by disturbances such as anoxia and nuisance algal blooms, which are associated with excess nutrients. Because sediment resuspension in the NRE can release nutrients into the overlying water column, investigation of the frequency of resuspension events and the conditions associated with them is necessary. In this study, in situ monitoring measurements of physical estuarine conditions (e.g., waves and suspended-sediment concentrations) obtained from an instrumented tripod, wind and river discharge records, and sediment cores, and analyzed using ¹³⁷Cs, are incorporated to investigate modem seabed dynamics occurring in the NRE. Additionally, the wind record is used to analyze interannual and annual variations in resuspension events over a recent decade. Analyses of monitoring data collected at a mud-dominated site in the central NRE reveals that during events with waves greater than -0.5 m in height, resuspension occurs in the NRE when a critical bed shear stress of 0.08 N/m is exceeded. After waves and bed shear stresses are predicted using the wind record and compared to the observed data, it is determined that an average of 55 resuspension events are occurring annually at the study site, although there is considerable annual and interannual variability. Because of the relatively large total, a similar high resuspension frequency is likely throughout the region. Nine successive sediment cores taken at the study site over a 397-day time span reveal that the NRE is subject to frequent periods of erosion and deposition of seabed sediment, potentially of large-scale (up to 5 cm). This affirms the estimates of high frequency of resuspension events made from wind data and highlights the importance of redeposition, as well as erosion, in characterizing seabed dynamics of the NRE. The sediment cores also showed that the study area is accumulating sediment at a net rate up to 1 cm/year. This study shows that although the NRE is accumulating sediment, the seabed is subject to frequent periods of erosion and deposition throughout the year and. as such, is transient. |
| General note | Presented to the faculty of the Department of Geological Sciences. |
| General note | Advisor: J. P. Walsh |
| General note | Advisor: D. Reide Corbett |
| Dissertation note | M.S. East Carolina University 2008 |
| Bibliography note | Includes bibliographical references (leaves 114-123). |
| Genre/form | Academic theses. |
| Genre/form | Academic theses. |
| Genre/form | Thèses et écrits académiques. |
Availability
| Library | Location | Call Number | Status | Item Actions |
|---|---|---|---|---|
| Joyner | University Archives | ASK AT SPECIAL COLLECTIONS DESK | ✔ Available | Request Material |
| Electronic Resources | Access Content Online | ✔ Available |