About 14 percent of the ice and permanent snow atop Washington state’s Mount Rainier melted in the past four decades, a new study suggests. Researchers arrived at that figure by comparing the estimated thickness and extent of ice seen in a 1970 aerial survey with those measured in 2007 and 2008. All but two of the 28 glaciers and snowfields on the mountain have thinned and shortened at their lower edges, and the exceptions probably thickened only because large amounts of rock fell upon the ice in recent years and insulated it from warming temperatures.
Overall, the volcanic peak lost enough ice to cover the entire state of Rhode Island to a depth of nearly eight inches during the 38-year interval between surveys, the researchers report online in the journal Geology. Mount Rainier’s ice and snow coverage expanded from the late 1950s to around 1980 during a wetter-than-normal phase of a climate cycle called the Pacific Decadal Oscillation. These recent trends indicate that Mount Rainier’s glaciers are very sensitive to warming and could grow again with modest changes in temperature or precipitation, the scientists say.
— ScienceNow, the daily online news service of the journal Science