Kyle W. Kelso

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

Dauphin Island, Alabama is a barrier island located in the Gulf of Mexico that supports local residence, tourism, commercial infrastructure, and the historical Fort Gaines. During the past decade the island has been impacted by several major hurricanes (Ivan, 2004; Katrina, 2005; Isaac, 2012). This, in addition to ongoing sea level rise, presents a continued threat to island stability. In an effort to properly restore and provide longer-term island resilience to future storms and sea-level rise, state and federal managers are taking a scientific investigative approach to identify the best options available to help formulate and implement a long-term plan for the Island s protection. Island morphology, including current seafloor and shoreline bathymetry data, is one of several aspects being investigated and funded through a grant from National Fish and Wildlife Foundation Gulf Environmental Benefit Fund. In August 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 only includes the single-beam data collected by the USGS. This USGS data release provides 1,165-line kilometers (km) of processed single-beam bathymetry (SBB) data collected by the USGS SPCMSC under the Field Activity Number (FAN) 2015-326-FA. This FAN encompasses four subFANs each of which represents one survey vessel; the RV Sallenger (15BIM10), the RV Jabba Jaw (15BIM11), the RV Shark (15BIM12), and the RV Chum (15BIM13). This data release provides SBB point data (x,y,z) in three datums: 1) the International Terrestrial Reference Frame of 2000 (ITRF00) and ellipsoid height (-47.04 meters (m) to -29.36 m); 2) the North American Datum 1983 in the CORS96 realization (NAD83 (CORS96)) for the horizontal and the North American Vertical Datum 1988 (NAVD88) for the vertical (-0.24 m to -17.33 m); and 3) NAD83 (CORS96) for the horizontal, and Mean Low or Lower Water (MLLW) for the vertical (-0.12 m to -17.93 m). Additional files include trackline shapefiles, respective digital and handwritten field logs, and a comprehensive 50-meter Digital Elevation Model (DEM).