HR: 0800h
AN: OS21B-1225    [Abstracts]
TI: The South Carolina Coastal Erosion Study: Nearshore Hydrodynamics Field Experiment
AU: * Haas, K A
EM: khaas@gtsav.gatech.edu
AF: Georgia Tech Savannah, 210 Technology Circle, Savannah, GA 31419 United States
AU: Voulgaris, G
EM: gvoulgaris@geol.sc.edu
AF: University of South Carolina, Department of Geological Sciences, Columbia, SC 29208 United States
AU: Demir, H
EM: hdemir@gtsav.gatech.edu
AF: Georgia Tech Savannah, 210 Technology Circle, Savannah, GA 31419 United States
AU: Work, P A
EM: pwork@gtsav.gatech.edu
AF: Georgia Tech Savannah, 210 Technology Circle, Savannah, GA 31419 United States
AU: Hanes, D M
EM: dhanes@usgs.gov
AF: US Geological Survey Pacific Science Center, 400 Natural Bridges Rd, Santa Cruz, CA 95060 United States
AB: As part of the South Carolina Coastal Erosion Study (SCCES) a nearshore field experiment was carried out for five days in December 2003 just north of Myrtle Beach, South Carolina, providing measurements of the waves, currents and morphological evolution. This experiment occurred concurrently with an extensive field campaign several kilometers offshore which included measurements of the waves and currents on and near a significant sand shoal. The purpose of the nearshore experiment was to aid in the identification of the effect of the offshore shoal on the nearshore processes. The resulting dataset will be used for verification of numerical models being used to investigate the hydrodynamics of the region. The experiment was carried out from December 10 to December 15 and consisted of measurements of the waves and currents, extensive surveys of the bathymetry every day, grab samples of the sediments, and video imagery. The hydrodynamics were measured using two Sontek Triton downward-looking Acoustic Doppler Velocimeters and two Nortek AquaDopp profilers arranged in a cross-shore line from inside the swash to several surf zone widths past the breakers. The bathymetric surveying was accomplished using both a differential GPS system and a total station. Surveying was performed each day in order to capture the morphological changes. On the last day, seven sediment samples were taken along a single cross-section to determine the sediment characteristics across the beach. Additionally, a video camera was located on a balcony of the top floor of a nearby hotel providing an excellent field of view of the entire experimental area. Digital video was captured directly onto a computer during all daylight hours and many control points were surveyed in each day to facilitate rectification of the imagery. A variety of conditions were encountered during the experiment, including two storm fronts which passed through, generating wind speeds up to 15 m/s. The first storm generated waves from the south driving a longshore current towards the north. After several relatively calm days with nearly normal incident waves the second front passed through the area with strong wind and waves approaching the shore with a large angle of incidence from the north. This drove an extremely strong longshore current in excess of 1.4 m/s and caused significant morphological changes.
DE: 4512 Currents
DE: 4546 Nearshore processes
DE: 4560 Surface waves and tides (1255)
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting