Sea Ice | North Pole Observations | Glaciers | Snow Cover

Glaciers are different from sea ice in that they are regions of fresh water ice on land. Their retreat and loss of volume is an indicator of Arctic change. Note in the figure below (left) that the loss of glacier volume over the past twenty-five years has occurred primarily in North America (open circles), followed by Russia (squares). Eurasia (closed circles) actually has an increase in glacier area, as increased precipitation may have offset the influence of warming in this region.

The figure below (right) shows that the contribution from melting glaciers to sea level rise has been on the order of 25 mm since 1960. This small rate of increase indicates that the contribution of glaciers in the Arctic towards global sea level rise is an issue for later in the century.

Accumulated annual volume changes of ice caps and glaciers in the American Arctic (red), the Russian Arctic (green), the Eurasian Arctic (blue), and the entire Arctic (purple). [M. Dyurgerov, INSTARR, University of Colorado]		Contribution of mountain and subpolar glaciers to sea level. Shown are sea level change (mm/year, red) and sea level rise (mm, blue). [From M. Dyurgerov, INSTARR, University of Colorado]

The Greenland ice cap represents a major storage of frozen fresh water on land. The year 2002 had the maximum yearly melt in the observational record (below).

Time Series (1979-2002) of maximum summer melt extent over Greenland (left) and examples of the melt extent during 1992 and 2002 (right). 2004 was not as extreme as 2002. (Images courtesy of Konrad Steffen and Russell Huff, CIRES, University of Colorado at Boulder). From NSIDC and NASA, see http://earthobservatory.nasa.gov/Study/vanishing/.

Find more information (references and websites)

• Repeat photographs of Alaska Glaciers from the National Snow and Ice Data Center
• AAAS News Release New Study in Science Warns of Greenland’s Accelerating Glaciers, (16 February 2006).
• Dyurgerov, M. B. and Dwyer, J. D., 2001: The steepening of glacier mass balance gradients with northern hemisphere warming. Zeitschrift fur Gletscherkunde und Glazialgeologie, 36 (2000), s. 107-118.
• Steffen, K., S. V. Nghiem, R. Huff, and G. Neumann (2004), The melt anomaly of 2002 on the Greenland Ice Sheet from active and passive microwave satellite observations, Geophys. Res. Lett., 31, L20402, doi:10.1029/2004GL020444.
• "Arctic glacier photos show less ice, snow after 45 years", Anchorage Daily News, September 26, 2004. See photos of Arctic Glacier in 1958 and 2003.