Climate Fact: Byrd Glacier Slide
The East Antarctic Ice Sheet has existed for about 35-40 million years, and has been relatively stable for about the last three million (i.e. the West Antarctic and Greenland Ice Sheets respond much more dramatically to climate changes than the East Antarctic Ice Sheet does). Over the second half of the 20th century, the continent as a whole warmed by about 0.9 degrees Fahrenheit, which has resulted in a general increase in melting. This warming has also, however, increased the amount of precipitation that East Antarctica receives, and as a result the East Antarctic Ice Sheet is about the same size it was in 1996. Since about half of the world’s observed sea level rise since 1900 has been due to the melting of land based glaciers, glaciologists are trying to better understand the processes of glacial melting and glacial “flow.” Glaciers often have recently melted water flowing beneath them, and this water can act as a lubricant forcing parts of the glacier to increase the rate that the “flow.” In East Antarctica between December of 2005 and February of 2007, the Byrd Glacier, which is called an outlet glacier because it is a “tongue” of the main ice sheet and extends into the ocean, moved about ten percent faster than its average rate. This acceleration has been attributed to the discharge of about 0.4 cubic miles worth of water from a subglacial lake that flowed underneath the glacier during this period.
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Source: Stearns, LA et al. “Increased flow speed on a large East Antarctic outlet glacier caused by subglacial floods.” Nature Geoscience 1 (2008): 827-831 and National Snow and Ice Data Center: State of the Cryosphere Report. “The Contribution of the Cryosphere to Sea Level Rise.” 1 February 2008. Accessed Online 12 December 2008
