Single-Beam Bathymetry Data Collected in 2015 Nearshore Dauphin Island, Alabama

Dauphin Island, Alabama is a barrier island located in the Northern Gulf of Mexico that supports local residences, tourism, commercial infrastructure, and the historical Fort Gaines. During the past decade, Dauphin Island has been impacted by several major hurricanes (Ivan, 2004; Katrina, 2005; Isaac, 2012). Storms, along with sea level rise, present a continued threat to island stability. State and federal managers are taking a scientific, investigative approach to identify the best options available to formulate and implement a long-term plan to properly restore Dauphin Island and provide resilience against future storms and sea-level rise. Island morphology, including current bathymetry and shoreline data, is one of several aspects being investigated and funded through a grant from the National Fish and Wildlife Foundation Gulf Environmental Benefit Fund. In 2015, the United States Geological Survey Saint Petersburg Coastal and Marine Science Center (USGS SPCMSC), in cooperation with the United States Army Corps of Engineers (USACE) and the state of Alabama, conducted bathymetric surveys of the nearshore waters surrounding Dauphin Island. This data release provides 1,165-line kilometers (km) of processed single-beam bathymetry (SBB) data collected by the USGS SPCMSC in August 2015 (Field Activity Number [FAN] 2015-326-FA). Data were acquired aboard four separate survey vessels; the RV Sallenger (subFAN, 15BIM10), the RV Jabba Jaw (subFAN, 15BIM11), the RV Shark (subFAN, 15BIM12), and the RV Chum (subFAN, 15BIM13). The data are provided in three datums: 1) the International Terrestrial Reference Frame of 2000 (ITRF00), ellipsoid height (-47.04 meters [m] to -29.36 m); 2) the North American Datum of 1983, realization of CORS96 (NAD83 [CORS96]) horizontal, and the North American Vertical Datum 1988 (NAVD88) vertical (-0.24 m to -17.33 m); and 3) the NAD83 (CORS96) horizontal, and Mean Lower Low Water (MLLW) vertical (-0.12 m to -17.93 m). Additional files include trackline shapefiles, digital and handwritten Field Activity Collection Systems (FACS) logs, a comprehensive 50-meter Digital Elevation Model (DEM), and formal Federal Geographic Data Committee (FGDC) metadata.