The findings are consistent with shrinking glaciers elsewhere. A recent US Geological Survey study found that three long-observed glaciers in Alaska and Washington state have been shrinking at a faster rate in recent years. Other scientists have predicted that Montana's Glacier National Park will be devoid of glaciers by 2030.
Worldwide, the vast majority of glaciers measured below 15,000 feet have been shrinking in recent decades, said Richard Armstrong, a senior researcher with the National Snow and Ice Data Center at the University of Colorado in Boulder.
"The rate at which they are diminishing is more or less parallel to the increase in the rate of global warming," Armstrong said.
University of Wyoming civil engineering graduate students Jake Edmunds, Derrick Thompson, and Jeb Bell found that Teton Glacier on 13,776-foot Grand Teton has lost about20 percent of its surface area over the past 40 years or so. Middle Teton Glacier on 12,804-foot Middle Teton has lost about 25 percent of its surface area.
Ice lost from the two glaciers combined could fill more than 500 Olympic-size swimming pools.
The smaller Teepe Glacier, located between the other two, has lost about 60 percent of its surface area.
How much ice remains in the glaciers isn't known, because measuring the glacier's volume would require hauling bulky radar equipment up the mountains — and onto the treacherous sloping ice — to measure the glaciers' depth.