HR: 0800h
AN: H41C-0309    [Abstracts]
TI: Topography of a Salt Marsh Island
AU: * Torres, R
EM: torres@geol.sc.edu
AF: University of South Carolina, Department of Geological Sciences, 701 Sumter Ave., EWS617, Columbia, SC 29204 United States
AB: Subtle variations in salt marsh topography affect over-marsh tidal currents and likely influence marsh sediment accumulation and resulting landforms. A DEM with vertical accuracy of ñ0.02 m was developed using real-time kinematic (RTK) GPS over a relatively pristine, uninhabited, 1.05 km2 salt marsh island. The island has 22 discrete tidal creek networks that typically become dry at low tide. The highest elevations are associated with discontinuous levees along the island perimeter, giving the island an overall "bowl" shape. The broad salt marsh platform consists of subtle ridges and valleys with up to 0.30 m of relief. The ridges separating discrete tidal creek networks. These ridges, however, are discontinuous and create hydraulic connections between discrete creek networks before the maximum tide height occurs. Topographic index analyses reveal two types of creek networks, one set that is relatively stable and a second set that may be undergoing headward extension.
UR: http://www.geol.sc.edu/torres
DE: 4235 Estuarine processes
DE: 1824 Geomorphology (1625)
DE: 1890 Wetlands
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting