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Looe Key, Florida, 1938-2004 Seafloor Elevation Stability Models, Maps, and Tables

July 27, 2021

The U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center (SPCMSC) conducted research to identify areas of seafloor elevation stability and instability based on elevation changes between the years of 1938 and 2004 at Looe Key coral reef near Big Pine Key, Florida, within a 19.06 square-kilometer area. USGS SPCMSC staff used seafloor elevation-change data from Yates and others (2017a) derived from an elevation-change analysis between two elevation datasets acquired in 1938 and 2004 using the methods of Yates and others (2017b). A seafloor stability threshold was determined for the 1938-2004 Looe Key elevation-change dataset based on the vertical uncertainty of the 1938 historical hydrographic survey and 2004 digital elevation model (DEM). Five stability categories (which include, Stable: 0.0 meters (m) to plus/minus 0.24 m or 0.0 m to plus/minus 0.49 m; Moderately stable: plus/minus 0.25 m to plus/minus 0.49 m; Moderately unstable: plus/minus 0.50 m to plus/minus 0.74 m; Mostly unstable: plus/minus 0.75 m to plus/minus 0.99 m; and Unstable: plus/minus 1.00 m to Max/Min elevation change) were created and used to define levels of stability and instability for each elevation-change value (1,687 data points) based on the amount of erosion and accretion during the 1938 to 2004 time period. Seafloor-stability point and triangulated irregular network (TIN) surface models were created at five different elevation-change data resolutions (1st order through 5th order) with each resolution becoming increasingly more detailed. The stability models were used to determine the level of seafloor stability at potential areas of interest for coral restoration and ten habitat types found at Looe Key. Stability surface (TIN) models were used for areas defined by specific XY geographic points, while stability point models were used for areas defined by bounding box coordinate locations.

This data release includes ArcGIS map packages containing the binned and color-coded stability point and surface (TIN) models, potential coral restoration locations, and habitat files; maps of each stability model; and data tables containing stability and elevation-change data for the potential coral restoration locations and habitat types. Data were collected under Florida Keys National Marine Sanctuary permit FKNMS-2016-068. Coral restoration locations were provided by Mote Marine Laboratory under Special Activity License SAL-18-1724-SCRP.

Yates, K.K., Zawada, D.G., Smiley, N.A., Tiling-Range, G., and Resnick, J.P., 2017a, Seafloor elevation change in Maui, St. Croix, St. Thomas, and the Florida Keys: U.S. Geological Survey data release,

Yates, K.K., Zawada, D.G., Smiley, N.A., and Tiling-Range, G., 2017b, Divergence of seafloor elevation and sea level rise in coral reef ecosystems: Biogeosciences, v. 14, p. 1739-1772,