GLIMS: Progress in mapping the world’s glaciers

The global land ice measurement from space (GLIMS) project is a cooperative effort of over sixty institutions world-wide with the goal of inventorying a majority of the world´s estimated 160000 glaciers. Data sent from regional center analysts to the GLIMS team at the national snow and ice data center (NSIDC) in Boulder, Colorado are inserted into a geospatial database. The GLIMS Glacier Database now contains outlines of over 58 000 glaciers. As submissions to the database from all over the world increase, we find that we must accommodate a greater diversity in the character and quality of the data submitted than was originally anticipated. We present an overview of the current glacier outline inventory, and examine issues related to data coverage, and data quality. A significant achievement of the GLIMS project is that the database and interfaces to it, as well as the GLIMSView tool, provided to help in the production of GLIMS analyses, are all built from open source software. Issues we´ve dealt with to achieve a high-quality glacier database include: 1. data submitted without proper metadata; 2. data submitted with incorrect georegistration; 3. varying analyst interpretations of what exactly constitutes a glacier; 4. arbitrary termination of glacier boundaries at political boundaries; 5. arbitrary termination of glacier boundaries at edges of available satellite images.