THE NGMDB GEOLOGIC MAP IMAGE LIBRARY -- DELIVERING SCANNED GEOLOGIC MAPS ONLINE

The USGS National Geologic Map Database project (NGMDB) has initiated an effort to build and provide on the Internet an Image Library of scanned geologic maps available as high-resolution compressed imagery. This effort implements MrSID wavelet compression technology to deliver highly detailed renderings of scanned geologic maps to the user's desktop through a standard Web browser. A dynamic, web-hosted cartographic search application is being constructed to assist public and private sector end users to locate maps in the NGMDB Image Library. The initial development of this library web application incorporates a dominantly open-source architecture consisting of a MySQL database, Zope content management system, and SVG format interactive graphics. Future development of the USGS Image Library is focused on providing a resource that the USGS and State geological survey participants can use to archive and manage digital map imagery and to deliver geologic maps online.