Figure 1. Map showing the locations of the survey areas (shaded in red) and local physiographic features south of Martha's Vineyard and north of Nantucket, Massachusetts. The area shaded in orange was surveyed in 2007 by the U.S. Geological Survey (USGS), using the same bathymetric sonar and seismic system for an unrelated project. Is., Island; MA, Massachusetts; MassGIS, Massachusetts Office of Geographic Information; MOF, Marine Operations Facility; NGDC, National Geophysical Data Center; NOAA, National Oceanic and Atmospheric Administration; UTM, Universal Transverse Mercator; WGS 84, World Geodetic System of 1984.