Oregon’s southernmost glacier has disappeared, observers say

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Until recently, Oregon’s southernmost glacier was on Mount Thielsen, an extinct volcanic mountain in the Cascade Range, east of Diamond Lake in Douglas County. But in the past five years, the Lathrop Glacier has disappeared.

Oregon Glaciers Institute President Anders Carlson said the Lathrop Glacier is just under half the size of a football field, with an area of ​​just 0.002 square kilometers. It was the smallest glacier in Oregon.

The glacier formed two arms descending from the steep falls. “It looked like a very vertical slide in a theme park, basically,” Carlson said.

Because of this, he collected avalanche slides, storing snow “almost like soda cans in a vending machine,” he said.

The area is heavily shaded, with very little direct sunlight. It was well designed to build a glacier in what is otherwise a hot, dry place – from a glacier’s perspective, anyway. A pond at the eastern end of the glacier-fed Thielsen Creek moraine has formed a miniature ecosystem.

“Lots of little vegetation living in a very lush setting that would not otherwise exist if it weren’t for a glacier that gives it water all summer, when there is no snow otherwise “said Carlson.

There is probably enough buried ice for the creek to keep functioning for another 10 or 20 years, but then it will dry up and the small ecosystem will disappear, he said.

The glacier had probably existed for hundreds, if not thousands of years. “Since the Romans or something like that, there had probably been some kind of glacier ice formed over that area over there,” Carlson said. But it wasn’t discovered until 1966, when Ted Lathrop spotted it on a hike.

Lathrop died in 1979, but The News-Review spoke to his nephew Ralph Nafziger, who returned with his uncle to Lathrop Glacier in 1968 and returned several times in the years since.

Nafziger worked as a geochemist for the US Bureau of Mines in Albany until 1996. He also enjoys hiking.

“I have climbed mountains all over the world and most of them were covered with glaciers,” he said.

The year before he saw the Mount Thielsen Glacier, Lathrop had been a resident physician on an expedition to the Juneau Icefields and had learned something about them. So when he looked at the steep north side of the mountain, he was pretty sure that was what he was seeing. Nafziger, Lathrop, and a US Forest Service district ranger took a closer look in 1968.

They followed the Pacific Crest Trail, climbed to a ridge, and looked straight down.

“It was a steep drop, almost 90 degrees. We were all young. We rappelled down to the ice on the glacier, ”said Nafziger.

A glacier must by definition be moving ice. So they put up stakes to measure the movement. The following year, they came back and saw that there was movement. But all their stakes had slipped and were lying in a heap at the bottom of the glacier.

As the glacier was clearly too steep to measure its exact movements with stakes, Nafziger decided to return regularly and photograph the glacier to record its changes. “We had to get there just at the right time because if we got there too early there was still snow to melt on the ice, and we couldn’t get an idea of ​​its size. If we got there too late then the new snow has started, ”he said.

Some years there was fresh snow as early as Labor Day. The other years, it was at the end of October. He learned that over time the glacier was shrinking. In 2016, the last year he saw it, there wasn’t much left.

Nafziger can no longer climb for health reasons, so he never saw him afterwards.

The exact date of Lathrop Glacier’s disappearance is not known. But in 2020, when the Oregon Glaciers Institute visited the site again, it was gone.

So what was the culprit behind Lathrop Glacier’s disappearance? The main suspects, according to Carlson, are climate change and the brutally hot summer of 2015.

It’s likely, he says, that they worked together to melt Lathrop down. The Cascades have warmed up considerably overall thanks to climate change. The summer average has risen between 2 and 3 degrees Fahrenheit since the early 1990s. “It’s a dramatic warming that is not seen at low altitudes,” Carlson said.

As it warms up, the snowpack melts earlier. Then came the summer of 2015. It was the hottest summer on record in the Cascades. The very hot summer was partly due to the fact that it was an El Niño year.

Then there was also the Blob, a “strange warm body of water” off the coast of Oregon that both warmed the air and blocked the snow, Carlson said. That year, the snowpack was the lowest on record. With the demise of Lathrop, the state’s southernmost glacier is now the Crook Glacier on Broken Top Mountain west of Bend.

Although Lathrop Glacier is gone, that doesn’t have to be the end of its story.

Professor Andrew Fountain’s long-standing love for snow and ice has evolved into a 40-year career in the study of glaciers. He said small glaciers like Lathrop often disappear one year and reform again.

“I would be very surprised if this had not happened before. In a good year of snow, I could see it coming back, ”he said. Yet, he said, 15% of Oregon and Washington’s glaciers have disappeared since the 1950s, and climate change is the “dominant force” in which this has happened.

Fountain said he recently submitted a study to the Journal of Geophysical Research which suggests that the glaciers in the Olympic Mountains will largely disappear by 2050 or 2060. Oregon will still have a few glaciers by then, but many of them. they will be gone, he said.

“I only realized a few months ago that, wait a minute, maybe 50 years from now no one will read my papers because there is nothing to read,” Fountain said.

Carlson predicted that Lathrop could return if humans stop contributing to climate change.

“We could start cooling down again if we could reduce greenhouse gases in the atmosphere. The state wants to grow glaciers and it wants to have snow, ”he said. With a cooler climate, the rain would turn to snow and the snow would stay long enough to form a glacier.

“It’s not yet a done deal. We could go back and the glaciers will grow back, ”he said.


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