Glaciologists from the University of Colorado Boulder and Trent University of Ontario, Canada led an international team to completing the first global glacier mapping. Virtually all of the world's glaciers, including their sizes and locations, volume calculations and global sea rise contributions have now been accounted for.
As part of the immense Randolph Glacier Inventory (RGI), the team mapped and cataloged the 198,000 glaciers to understand the relationship between anthropogenic greenhouse gases and the rising seas over the next decade.
CU-Boulder Professor Graham Cogley led the team which included 74 scientists from 18 countries. Most of the team worked on an unpaid, volunteer basis.
The recently released Fifth Assessment of the Intergovernmental Panel on Climate Change (IPCC) is where the project information is destined. Pfeffer, lead author on the new IPCC sea rise chapter and fellow at CU-Boulder's Institute of Arctic and Alpine Research (INSTAAR), explained in a press release that although the large ice sheets in Greenland and the Antarctic are losing mass, it is actually the smaller glaciers that are contributing the most to the rising seas. In a CU-Boulder press release, Pffeffer said, " I don't think anyone could make meaningful progress on projecting glacier changes if the Randolph Inventory was not available."
Pfeffer, a professor in CU-Boulder's civil, environmental and architectural engineering department, is also the first author on the RGI paper published online today in the Journal of Glaciology. Pfeffer explained that while the funding in the United States has been exhausted, (exception: NASA) glacial studies have been able to continue due to funding by numerous European groups.
All of this research has many applications including making forecasts of glacier-climate interactions more precise. In the press release, Cogley was quoted as saying, " This means that people can now do research they simply could not do before. It's now possible to conduct much more robust modeling for what might happen to these glaciers in the future."
Pfeffer and the team mapped intricate glacier complexes in Alaska, Patagonia, central Asia and the Himalayas. Included, were the peripheral glaciers that surround the great ice sheets in Greenland and Antarctica. Pfeffer said, " In order to model these glaciers, we have to know their individual characteristics, not simply an average or aggregate picture. That was on of the most difficult parts of the project." Using satellite images and maps, the team outlined each glacier's area and location. The volume of each glacier was obtained with a combination of the area/location information and a digital elevation model, a technique known as "power law scaling".
Not only is sea rise a concern when it comes to melting glaciers, other results are a severe affect on regional water resources for uses like irrigation and hydropower, as well as "glacier outburst" floods.
For comparison, the extent of glaciers in the RGI is equal to an area slightly larger than Texas.
Another comparison, for perspectives sake, is that 1 percent of the collective amount of water stored in the Greenland and Antarctic giant ice sheets equals slightly more than 200 feet of sea rise. Pfeffer stated, "A lot of people think that the contribution of glaciers to sea rise is insignificant when compared with the big ice sheets. But in the first several decades of the present century it is going to be this glacier reservoir that will be the primary contributor to sea rise. The real concern for city planners and coastal engineers will be in the coming decades, because 2100 is pretty far off the have to make meaningful decisions."
Part of the RGI and the baseline dataset was based on the Global Land Ice Measurements from the Space Initiative (GLIMS), involving more than 60 institutions worldwide.
"Ice2Sea", a European funded program, was another important tool for the RGI and brings scientific and operational expertise from 24 leading institutions from Europe and around the world.
CU-Boulder's National Snow and Ice Data Center (NSIDC) maintains GLIMS glacier database and website.
GLIMS research team at NSIDC includes principal investigator Richard Armstrong, tech lead Bruce Raup and remote sensing sepcialist Siri Jodha Singh Khalsa.
NSIDC is a part of the Cooperative Institute for Research in Environmental Sciences (CIRES), a joint venture between CU-Boulder and the National Oceanic and Atmospheric Administration.
Information on INSTAAR ( httsp://instaar.colorado.edu ), NSIDC ( nsidc.org ), GLIMS ( www.glims.org ), Ice2Sea ( www.ice2sea.eu ), and CIRES ( cires.colorado.edu/index.html ) can be obtained at those websites.
credits: CU Boulder press release