Looking at the planet’s cryosphere as a whole, Alaska’s glaciers account for far less than 1.0 percent of the world’s land ice. But their melt contributes about 7.0 percent of the water that is raising the world’s sea levels, according to a 2018 study published in the journal Geophysical Research Letters.
Melting due to global warming has left the slow-moving glaciers much diminished. Glaciers are still spectacular and cruise lines still bring boatloads of tourists to Alaska’s shores to view their beauty, however, they now represent the collapse of an important system that has for millions of years helped to keep our planet cool and our sea levels stable.
Lemon Creek Glacier in Juneau is one example of rapid ice loss. Geological records date back to the early 1940s. This is the second year that record mass loss of 3 meters (9.8 feet) has disappeared from the surface of the glacier, U.S. Geological Survey glaciologist Louis Sass told Reuters.
Surprisingly, the melt went all the way up to the summit, according to Sass. “That’s a really bad sign for a glacier,” he said, noting that high-altitude melt means there is no accumulation of snow to compact into ice and help offset lower-elevation losses.
And this past summer’s record temperatures helped to spark the melt, including 90-degree temperatures in a region where 60s and 70s are the norm. The melting caused rivers to flow out of their banks and all that meltwater poured into the ocean.
The Wolverine Glacier on the Kenai Peninsula south of Anchorage had the second-highest record mass loss. Sass said it failed to match the record set in 2004 only because so much of the glacier had already melted. “The lower part’s completely gone now,” he said.
Bear Glacier in Kenai Fjords National Park retreated by nearly a kilometer (0.62 miles) in just 11 months, according to August measurements by the National Park Service. This glacier is the one President Barack Obama visited to call attention to climate change.
“It’s almost like you popped it and it started to deflate,” said Nate Lewis, a Seward-based wilderness guide who takes travelers into the new lake that has formed at the foot of the shrinking glacier.
Melting glaciers also have a local impact, other than adding to increases in sea level. Glacial melt affects salmon spawning streams and marine animal and fish habitats. The voids in the ice lead to the creation of lakes, and the outburst from those lakes has been increasing in frequency.
A number of studies have been published this year as scientists attempt to put into hard numbers the amount of meltwater flowing from Alaska’s glaciers. “Alaska’s glaciers are in kind of a Goldilocks position,” says Twila Moon, a research scientist with the National Snow and Ice Data Center at the University of Colorado Boulder.
“They are far enough north that they get the snow necessary to form very large glaciers, but they’re also at that southern Arctic edge where we see so much change from warming.”
In one study, published in April this year, scientists estimated that glaciers have lost more than 9,000 billion tons (9 625 000 000 000 tons) of ice between 1961 and 2016, The largest contributors were glaciers in Alaska, followed by the melting ice fields in Patagonia and glaciers in the Arctic regions.
