Figure 5. Map showing modern sediment thickness offshore of Fire Island, New York, 2011. Regional bathymetric contours are in meters (m) below the North American Vertical Datum of 1988 (NAVD 88). The inset map shows the location of the chirp seismic-reflection profiles, overlain on bathymetry (fig. 3), that were used to map the Holocene transgressive surface (fig. 6) and thus the modern sediment thickness. Figure modified from Schwab and others (2013).