Zhadang glacier
May 7, 2014

Scientists Complete First-Ever Global Inventory Of Glaciers

redOrbit Staff & Wire Reports - Your Universe Online

A team of 74 scientists from 18 countries, mostly working on an unpaid volunteer basis, have mapped and catalogued nearly 200,000 glaciers, creating the first-ever global inventory of icebergs and ice floes.

The catalogue, which was compiled as part of the Randolph Glacier Inventory (RGI) project, includes information about locations and size. It will allow for calculations of volume, as well as their ongoing contributions to climate change-related increases in global sea levels, the study authors said in a statement Tuesday.

Based on the survey team’s findings, which appear in the latest edition of the Journal of Glaciology, glaciers cover an area of approximately 730,000 km2 and have a volume of about 170,000 km3. In all, the scientists said that they discovered roughly 198,000 glaciers.

However, the authors explained that this number is in constant flux, as smaller glaciers frequently disappear and larger ones become fragmented. More important, they said, is the fact that each one is now represented by a computer-readable outline, which will make it easier for experts to produce glacier-climate interaction models.

“This boost to the infrastructure means that people can now do research that they simply couldn’t do properly before,” explained Trent University Professor Graham Cogley, one of the coordinators of the RGI project as well as a study author, in a separate statement.

He and his colleagues report that the total extent of the RGI glaciers is approximately 280,000 square miles or 727,000 square kilometers. For comparison sake, that’s an area slightly larger than the state of Texas, or the combined size of Germany, Switzerland and Poland. The team also estimated that the corresponding total volume of sea level rise collectively held by the world’s glaciers is 14 to 18 inches (or 350 to 470 millimeters).

One of the main reasons the researchers began working on the project was to provide the best quality data possible for the recently-released Fifth Assessment of the Intergovernmental Panel on Climate Change (IPCC). While it was found that both the Greenland and Antarctic ice sheets are losing mass, the RGI team found that smaller glaciers have been contributing the most to sea level increases (and will continue to do so).

“The rapid shrinkage of glaciers during the past 20 years is also well-recognizable in the Alps and other parts of the world,” said study co-author Dr. Frank Paul of the University of Zurich, who also served as the lead author of the first part of the IPCC report that was published last September.

“Here and in other parts of the world the diminishing glaciers also impact on regional to local scale hydrology, natural hazards, and livelihoods in otherwise dry mountain regions. Accurate knowledge of water reserves and their future evolution is thus key for local authorities for early implementation of mitigation measures,” added Tobias Bolch, who is affiliated with both the University of Zurich and Technische Universität Dresden.

A portion of the RGI data was based on the Global Land Ice Measurements from Space Initiative (GLIMS), which involved over 60 institutions and contributed to the project’s baseline dataset, the researchers said. The GLIMS glacier database and website are maintained by CU-Boulder's National Snow and Ice Data Center (NSIDC). The ESA, NASA, the EU’s Framework 7 Program and several universities also financially supported the research.