HR: 1340h
AN: OS53A-0978    [Abstracts]
TI: Geophysical and Geotechnical Determination of Sand Resources on the Florida Atlantic Continental Shelf: Preliminary Results
AU: * Finkl, C W
EM: cfinkl@coastalplanning.net
AF: Coastal Planning & Engineering, 2481 NW Boca Raton Blvd, Boca Raton, FL 33431, United States
AU: Andrews, J L
EM: jandrews@coastalplanning.net
AF: Coastal Planning & Engineering, 2481 NW Boca Raton Blvd, Boca Raton, FL 33431, United States
AU: Suthard, B C
EM: bsuthard@coastalplanning.net
AF: Coastal Planning & Engineering, 2481 NW Boca Raton Blvd, Boca Raton, FL 33431, United States
AU: Robertson, W
EM: wrobertson@coastalplanning.net
AF: Coastal Planning & Engineering, 2481 NW Boca Raton Blvd, Boca Raton, FL 33431, United States
AB: The State of Florida is committed to maintaining beaches to sustain beach width and protect coastal infrastructure. Nearshore sand resources must be identified and cataloged for potential beach nourishment projects in response to sea-level rise and increased tropical storm activity. Given the vast length of Florida coastline, application of a variety of remote sensing techniques are required for measuring large areas in a short amount of time. The study area encompasses a shelf area of about 2,053,220 ha (20,532 km2) from Miami to the Georgia State line (about 653 km shoreline length) and extends up to 27 km offshore to about the 45 m isobath offshore Jacksonville. The continental shelf along the east coast of the Florida peninsula contains a wide range of seafloor environments that lie above the Florida-Hatteras Slope on the shoreface and inner, middle, and outer shelf floors. This study used Airborne Laser Bathymetry (ALB), 3D digital terrain models based on reformatted NOAA bathymetric data, sidescan sonar, and seismic reflection profiling to map seafloor geomorphological conditions that range from coralline-algal reef systems to drowned karst, submerged paleo shorelines (drowned beach ridge plains), and buried paleo channels. Seatruthing of morphosedimentary features is achieved via jetprobe and vibracore surveys in the study of inter-reefal sand troughs, ebb-tidal deltas, transverse bars, shoals, sand waves, ridges, and banks. Preliminary results, which visualize seafloor topography as color-ramped morphoforms, indicate the presence of sedimentary deposits that may constitute viable sand resources for shore protection in the form of beach renourishment. Use of ALB and reformatted NOAA bathymetric data in the form of 3D terrain models permits classification of submarine landform topologies that was heretofore not possible using isobaths. The combination of multiple remote sensing methods showed the spatial distribution of morphosedimentary features and provided the ability to assess sand resource potential on the shelf. Sand resources on the Florida Atlantic continental shelf amount to something on the order of about 85 x 109 m3. These potential sand volumes, based on average 3 m depth assumptions, break down to about 1 x 109 m3 for the southeast (Miami, Broward, Palm Beach counties), 4.3 x 109 m3 for the central (Martin, St. Lucie, Indian River, Brevard counties), and 78.5 x 109 m3 for the northeast (Volusia, Flagler, St. Johns, Duval, Nassau counties) Florida shelf areas. It is effective to use multiple remote sensing methods to locate large sand bodies, but more detailed geotechnical surveys are required to better estimate these sand resource potentials.
DE: 0933 Remote sensing
DE: 3020 Littoral processes
DE: 3022 Marine sediments: processes and transport
DE: 3045 Seafloor morphology, geology, and geophysics
DE: 4217 Coastal processes
SC: Ocean Sciences [OS]
MN: 2007 Fall Meeting