The Topographic and Bathymetric Shaded Relief of North America map layer shows depth and elevation ranges using colors, with relief enhanced by shading. The image was derived from two pre-existing map layers; the Bathymetric Shaded Relief of North America, derived from ETOPO2 data, and the Color North America Shaded Relief, derived from GTOPO30 data. This layer is part of the 1997-2014 edition National Atlas of the United States. The topographic and bathymetric shaded relief image was developed to portray the land and water terrain of North America. The image is intended for visual purposes only. The original ETOPO2 and (or) GTOPO30 data must be used for conducting analysis and determining specific bathymetric and elevation values.