HR: 0800h
AN: H41C-0306    [Abstracts]
TI: Morphological controls on marsh creek network flow patterns
AU: * Styles, R
EM: rstyles@geol.sc.edu
AF: University of South Carolina, 701 Sumter St, Columbia, SC 29208 United States
AU: Torres, R
EM: torres@geol.sc.edu
AF: University of South Carolina, 701 Sumter St, Columbia, SC 29208 United States
AB: An experimental study to investigate flow characteristics and salt marsh morphology was carried out in the North Inlet/Winyah Bay Estuary, South Carolina. Acoustic Doppler current meters (ADVs) were placed at the terminus of two abutting creek networks that were separated by a topographic divide. An additional acoustic profiler was placed near the mouth of one of the creeks. Flow patterns observed during spring tide indicated an abrupt switch in current direction during flood before vanishing at slack high water. This reversal in flow direction was mirrored during the ebb phase, in which initial ebbing did not drain the creek but rather flowed further onto the marsh surface. This pattern was also seen in the profile measurements at all depths. In contrast, the current moved up both creeks on flood and out on ebb during the neap phase. The marsh surrounding the study site is located within a meander of the main tidal channel. Although the cause of the spring tide flow pattern is not completely understood, it may be related to inundation of the marsh island producing a net fluid transport down the pressure gradient formed by the propagating tidal wave. Therefore, topography exerts the dominant control on the flow over the marsh surface during neap tide, yet topography and hydrodynamics exert control during spring tide.
DE: 4235 Estuarine processes
DE: 1824 Geomorphology (1625)
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting