Figure 2. High-resolution chirp seismic-reflection profile illustrating stratigraphic features and geometries discussed in the text, offshore of Fire Island, New York, 2011. Location of the profile is shown in figure 1. Approximate water depth in meters is based on two-way travel time of 1,500 meters per second. A, The Holocene marine transgressive surface is marked by a yellow dotted line. Glaciofluvial channels and older Pleistocene sediments are marked by orange dotted lines, and the underlying Cretaceous-age coastal plain strata and the coastal plain unconformity are shown as green dotted lines. B, The chirp seismic-reflection profile displayed without interpretations. Figure modified from Schwab and others (2013).