The Bathymetric Shaded Relief of North America map layer shows depth ranges using colors, with relief enhanced by shading. The image was derived from the National Geophysical Data Center's ETOPO2 elevation data, which is an elevation database gridded at 2-minute resolution, containing elevation and bathymetry for the world. The image was produced from the October 2001 data set. This layer is part of the 1997-2014 edition of the National Atlas of the United States.The bathymetric shaded relief image was developed to portray the underwater terrain of North America. The image is intended for visual purposes only. The original ETOPO2 data must be used for conducting analysis and determining specific bathymetric values.