A bedrock ridge is melting through the upper reaches of Hayden Glacier. This process will cut the lower glacier off from the snow that accumulates in the upper reaches, hastening its demise in the same manner that occurred for Bend Glacier.

In the battle against global warming, glaciers in the Central Oregon Cascades have not fared well in 2022. Collier and Bend glaciers, two massive sheets of moving ice high in the mountains west of Bend, lost an average thickness of 11 feet this summer.

“It was another lousy year to be a glacier in Oregon,” said Gordon Grant, a Corvallis-based research hydrologist with the U.S. Forest Service.

Glaciers are critical features of Central Oregon’s ecosystem as their late summer melt helps bring cool, clear water to

rivers and streams in the fall months, sustaining habitat for fish and other aquatic wildlife.

The availability of water for irrigation districts in Central Oregon is also threatened by the loss of glaciers as they provide the farming community with a steady source of late-season run-off.

“These hot summers are dramatically removing the ice volume in the Central Cascades,” said Anders Carlson, president of the Oregon Glaciers Institute, a nonprofit that documents Oregon’s glaciers, measures their health and projects the future of the state’s glaciers. “This isn’t just warm summers causing glacier margins to retreat to higher elevations. The summers are melting the glaciers away at all elevations.”

The loss of 11 feet of ice from Collier Glacier alone equates to 18,000 city buses, said Carlson. Converted to water, 400 million gallons melted away, enough to fill 650 Olympic-sized swimming pools.

Glacial melt has been intense in each of the past three summers and four out of the last six, said Carlson. The glaciers are melting in part because snowpack that normally rests on top of the glaciers — protecting them from the sun — has dwindled under the intense summer heat.

Carlson said just 4% of Collier Glacier had snow on it by the end of this past summer. A healthy glacier should have 70% of its surface covered by snow at the end of summer, he said. Any amount less than that results in a net loss of glacier volume.

High elevation thinning of glaciers expose bedrock, effectively splitting up the glaciers into separate chunks. When the lower and upper parts of a glacier are disconnected, it prevents ice in upper areas from replenishing the lower reaches, hastening their disappearance.

“This already happened in Bend Glacier and is occurring right now on Collier and Hayden glaciers,” said Carlson.

A century ago Oregon was home to at least 43 glaciers. There are just 27 left according to the institute. Glaciers have been shrinking for decades, but their rate of decline has accelerated in recent years, said Carlson.

“This makes three years in a row with no or minimal accumulation of snow on Collier. In fact, we now have six years of satellite measurements of snow cover for Collier and four out of those six years are abysmal,” Carlson said.

Collier Glacier did gain mass in 2017 and 2019, but those gains were wiped away by intense summertime heat each summer since 2020.

“Central Cascade glaciers are almost literally a block of ice taken out of the freezer and plopped on your kitchen counter where it melts on all sides, not just the lowest elevation side,” said Carlson.

The glacial melt this year came during one of the hottest summers on record in the Pacific Northwest. In August, Oregon’s average temperature was 6.6 degrees above normal, according to data from the National Oceanic and Atmospheric Administration.

This year’s high temps follow the heat dome event in June of 2021, which shattered temperature records. In 2020 the Pacific Northwest also experienced a long, hot summer that culminated with the extreme Labor Day forest fires.

While this year’s snowy spring and cool June held promise for a better year for glaciers, the hot August temperatures and warm autumn reversed those gains.

Summers are also growing longer in duration, said Carlson, with the month of October being unusually dry in recent years.

“I really thought we’d have a year of net gains on the glaciers, or at least not insane losses of mass, as the snowpack was quite high coming into the summer due to that cold and snowy spring,” said Carlson.

“Even when you think the cards are dealt in your favor, global warming has some trump cards up its sleeve.”