Mapping and Characterization of Paleoshoreline Features on the West Florida Shelf

High-resolution bathymetry data is limited to less than 5% coverage of the wide, shallow West Florida Shelf. The Continental Shelf Characterization and Mapping Project (C-SCAMP) has collected over 1200km2 of high-resolution multibeam bathymetry and backscatter data from 2015 to 2017, amounting to an additional 1%, and mapping efforts are ongoing. Complementary data sets including sediment analysis of Shipek grab samples and visual analysis of towed-underwater video from the Camera-Based Assessment Survey System (C-BASS) help to further identify seafloor characteristics and habitat assemblages in these areas. Multibeam data reveal three paleoshoreline complexes of similar character between 40m and 80m water depth. These paleo-peninsulas extend 30-40km oblique to regional contours. Each area includes a main ridge axis with smaller ridge complexes splitting off on the southern end, and a prominent ridge along the steeper western margin of the feature. Preserved features observed in bathymetry within these paleo-peninsulas include shorelines, dune complexes, shoals, tidal deltas, and spit formations. Preliminary analysis of sediment samples shows that higher backscatter on the shallower portions of these features corresponds with coarser-grained sediments. The high-relief ridges apparent in bathymetry are shown to be moderate- to high-relief hard bottom in towed-underwater video. The analysis of these different data types will result in detailed description of the geomorphology and benthic habitat characteristics, including relationships between depth, slope, rugosity, backscatter, and bottom types. These characteristics are influenced by paleoshoreline structures. Previously collected sub-surface data, as well as modern analogs, such as the west coast of Florida, western Australia and other low-latitude, low-relief coasts provide insight into the geologic origin of these features.