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 2016 and 2017 at Crocker Reef near Islamorada, Florida, within a 33.62 square-kilometer area. USGS SPCMSC staff used seafloor elevation-change data from Yates and others (2019) derived from an elevation-change analysis between two elevation datasets acquired in 2016 and 2017 using the methods of Yates and others (2017). A seafloor stability threshold was determined for the 2016-2017 Crocker Reef elevation-change dataset based on the vertical uncertainty of the 2016 and 2017 digital elevation models (DEMs). 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 (8,402,223 data points at 2-m horizontal resolution) based on the amount of erosion and accretion during the 2016 to 2017 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 point models were used to determine the level of seafloor stability at nine habitat types found at Crocker Reef.
This data release includes ArcGIS map packages containing the binned and color-coded stability point and surface (TIN) models and habitat files; maps of each stability model; and data tables containing stability and elevation-change data for the habitat types. Data were collected under Florida Keys National Marine Sanctuary permit FKNMS-2016-068.
Yates, K.K., Zawada, D.G., Arsenault, S.R., and Fehr, Z.W., 2019, Seafloor elevation change from 2016 to 2017 at Crocker Reef, Florida Keys-Impacts from Hurricane Irma: U.S. Geological Survey data release, https://doi.org/10.5066/P9JI465S.
Yates, K.K., Zawada, D.G., Smiley, N.A., and Tiling-Range, G., 2017, Divergence of seafloor elevation and sea level rise in coral reef ecosystems: Biogeosciences, v. 14, p. 1739-1772, https://doi.org/10.5194/bg-14-1739-2017.