Anderson Glacier in the Olympic Mountains is gone, and the lack of glacial meltwater has caused the Quinault River to reach new lows.
Montana’s Glacier National Park had 150 glaciers in 1850; today there are 25.
Greenland’s Helheim Glacier is retreating 110 feet per day.
Bolivia’s Chacaltaya Glacier, at one time one of the highest-altitude ski resorts on earth, no longer exists, threatening water and power supplies in the Andean region.
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Glacial retreat has accelerated since the 1980s in the Alps, which contain 40 percent of Europe’s fresh water supply.
Eighty-two percent of the glaciers in the greater Himalayas, a source of drinking and irrigation water for more than one-sixth of the world’s population, shrank between 1950 and 2000.
A study published in Geophysical Research Letters, a journal of the American Geophysical Union, documents the importance of glaciers in recharging aquifers and keeping rivers flowing – and succinctly explains how glaciers do it. The study also illustrates what’s at stake as our glaciers disappear.
A research team from the U.S. Geological Survey and U.S. Army Corps of Engineers’ Cold Regions Research and Engineering Laboratory studied a watershed in a semi-dry climate in the eastern Alaska Range to look at how meltwater from two small mountain glaciers flowed through the system and influenced the mountain streams, rivers and groundwater all year long.
“I think that mountain glaciers in the Arctic and sub-Arctic have really been underappreciated as a source of water to the landscape,” Anna Liljedahl said in an announcement of the research. She is the study’s lead author and an associate professor at the University of Alaska Fairbanks’ Water and Environmental Research Center.
Through extensive field measurements, the team found that Alaska’s Jarvis and Gulkana glaciers contributed as much as 66 percent of the annual flow in mountain streams that drain into the Delta River. Yet when the team compared the water volume at an upper site and another site about 35 miles downstream on one of the major mountain streams, they found that half the water diverted into an aquifer, where it recharged groundwater supplies and drained into other streams.
“These headwater streams, coming off the mountains and into the lowland, are like [a] water line to your house peppered with holes – half of the water disappearing into the ground and recharging your neighbor’s house well, instead of it all reaching your kitchen faucet,” Liljedahl said in the announcement.
Liljedahl said the recharge of the aquifers is important because they don’t freeze during the winter and are the only source of water to the rivers during this time. In the town of Delta Junction, adjacent to the Delta River, the water table drops more than 33 feet each winter as the aquifers drain into the Tanana River.
