Mode of access: Internet from the USGS web site. Address as of 11/6/07: http://pubs.usgs.gov/of/2007/1051/pdf/OF07-1051%5F508.pdf ; current access via PURL. System requirements: PC with Internet access and Adobe Acrobat Reader or similar software to handle .pdf (Portable Document Format) files.
Relief and depth shown by shading and gradient tints. Title from HTML index page (viewed on May 22, 2007).