HR: 0800h
AN: H51I-0898    [Abstracts]
TI: Sand Ripples and Surficial Grain Size on the Florida Continental Shelf Following 2004 Hurricane Ivan
AU: * Hanes, D M
EM: dhanes@usgs.gov
AF: USGS Coastal and Marine Geology, 400 Natural Bridges Drive, Santa Cruz, CA 95060, United States
AU: Erikson, L H
EM: lerikson@usgs.gov
AF: USGS Coastal and Marine Geology, 400 Natural Bridges Drive, Santa Cruz, CA 95060, United States
AU: Traykovski, P
EM: ptraykovski@whoi.edu
AF: Woods Hole Oceanograhic Institute, MS#11, Woods Hole, MA 02543, United States
AB: Measurements of ripple dimensions, ripple orientation, and seabed surficial grain size were obtained from the Florida gulf coast (south of Fort Walton Beach) during the ONR RipplesDRI/SAX04 experiment. The data were collected with a ship-tethered tripod containing high resolution acoustic and optical sensors including cameras, projected light, and a scanning sonar. Measurements were collected on a cross-shore transect in water depths ranging from 3 m to 42 m. The measurements were conducted in September, 2004, two weeks after the passage of Hurricane Ivan (the "eye" made landfall 150 km to the west of the study area) and again in November, 2004. Ripples were found throughout the region during both measurement periods, even at the deepest measurement sites. Wave ripples, particularly in depths greater than 30 meters, are presumed to be relict, having been generated across the entire shelf by Hurricane Ivan. The measurements exhibit high spatial variability, with general trends for increasing ripple wavelength, ripple height, and bed sediment grain size with increasing depth and distance offshore.
DE: 3022 Marine sediments: processes and transport
DE: 3045 Seafloor morphology, geology, and geophysics
DE: 4217 Coastal processes
DE: 4219 Continental shelf and slope processes (3002)
DE: 4558 Sediment transport (1862)
SC: Hydrology [H]
MN: 2007 Fall Meeting