Glaciers are highly sensitive indicators of past and present climate change. Their current area and volume are a response to both near-term and long-term changes in both temperature and precipitation. In recent decades most glaciers have been steadily shrinking. Because glaciers are important indicators of past and future climatic changes, it is important that a globally complete glacier inventory be maintained that contains the current extent as well as the rates of change of the world's glaciers. The GLIMS project (Global Land Ice Measurements from Space) is currently creating a unique glacier inventory storing critical information about the extent and rates of change of the world's estimated 200,000 glaciers.

GLIMS is an international collaborative project that includes more than sixty institutions world-wide: its goal is to create this globally comprehensive inventory of land ice including measurements of glacier area, geometry, surface velocity, and snow line elevation. To perform these analyses, the GLIMS project uses satellite data, primarily from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and the Landsat Enhanced Thematic Mapper Plus (ETM+) as well as historical information derived from maps and aerial photographs.

The analysis results are submitted to the GLIMS database at the National Snow and Ice Data Center (NSIDC) in Boulder, Colorado. The GLIMS database is funded through research grants from The National Aeronautics and Space Administration (NASA). The GLIMS database is designed to be a logical extension of the World Glacier Inventory (WGI) of the World Glacier Monitoring Service (WGMS) and stores the full complement of the WGMS-defined glacier characteristics. Each analysis received by the GLIMS team at NSIDC is ingested into the GLIMS Glacier Database and made available to the public via the World Wide Web using an interactive mapping web site based on the open source package MapServer. The web interface thus acts as a visual front-end providing easy access to the GLIMS Glacier Database. New glacier data are continually being added to the database.

The GLIMS MapServer web site allows users to view and query several thematic layers, including glacier outlines, GLIMS Regional Center locations, and the World Glacier Inventory. Query results can be downloaded into a number of GIS-compatible formats, including ESRI Shapefiles, MapInfo tables, and Geographic Mark-up Language (GML). The web site allows users to perform a variety functions on the data including attribute querying, selecting, and exporting the glacial data through the use of a visual selection map and/or a form-based selection process. The data are stored in a spatially enabled database (PostGIS), which has sophisticated functions for spatial data analysis and query. The GLIMS Glacier Database also allows the user to view reduced-resolution ASTER browse images and to query the ASTER image metadata. The MapServer application can serve data from the GLIMS Glacier Database to other OGC-compliant services via OGC-standard protocols, thereby increasing the utility of this glacier data set.