THE BOOM
In 2017, the flooding of a stream left hikers trapped on Mount Baker’s Heliotrope Ridge Trail. As temperatures in the region continue to rise, rescuers and researchers think events like this could become more common and severe.
Story by Noah Matijascic| Photos by Riley Marcus and Hannah Gabrielson
“The look on her face will stay in my mind forever,” said hiker Paula Parisot, talking about what was supposed to be a summertime family picnic on the popular Heliotrope Ridge Trail on Washington state’s Mount Baker.
“Frankly, if she would’ve been swept down that stream she would have died. I don’t think anybody could have survived it,” she said.
On August 20, 2017, Parisot and over a dozen other hikers became stranded. The ankle-deep, glacier fed creek they had crossed 30 minutes before became a waist-deep torrent of muddy water and debris. What happened that day may seem like an extreme occurrence, but alpine flooding is a natural consequence of glaciers constantly shifting and changing. With mountain temperatures on the rise, it’s likely these events will become more frequent and severe.
“While we were sitting there eating our sandwiches we heard a large boom,” Parisot said. The noise seemed strange to them, but they quickly brushed it off. When they later returned to the stream they had easily crossed on their hike up the mountain, they were surprised by what they found.
“We could see that this wasn’t the same little stream we had just crossed,” she said.
Alton Byers, a senior research associate at the Institute of Arctic and Alpine Research at the University of Colorado, Boulder, speculates that the boom and subsequent flooding may have been caused by an englacial conduit flood. This is a little-studied phenomenon where water trapped in caves and pathways within glaciers suddenly escapes. He is one of the few people to ever document these floods, after witnessing one for himself in Nepal in 2016.
“Imagine these glaciers are like a big piece of Swiss cheese, filled with these caves that are, in turn, filled with water,” Byers said. “All it takes is for the ice lens holding in the water of one to burst.” This bursting is a potential source of the boom Parisot heard.
“I’m not sure what happened up on Mt. Baker, but the similarity [between the Mt. Baker and Nepal floods] was that people heard a loud explosion before the flood.”
Englacial conduit floods are just one of many glacial hazards that research suggests are increasing as the climate changes. A 2013 study published in Science of The Total Environment was conducted in the Swiss Alps and found that as glaciers shrink and change, the rate of events like lake formation, ice avalanches and landslides rises, destabilizing high-mountain environments.
“There is clear indication that floods like these are increasing in frequency,” Byers said, especially in the Himalayas. “They only used to occur about once every 50 years, but now it’s pretty much once every couple of years.”
When Parisot and the other hikers found the stream flooded, one woman tried to cross. A thin yellow rope tied from bank to bank was her only lifeline, and she slipped a few feet from the shore. Parisot’s husband and another hiker helped pull her to safety. Although they may have saved her life, they never learned her name. The hikers were stuck for three or four hours before Karl Henize and Katlynne Schaumberg, guides for the Bellingham-based American Alpine Institute, stumbled upon the scene while leading a group of climbers down the trail.
“We noticed that this greatly enlarged stream had gone into one of the existing creek beds and raised the water level to a point where it was no longer safe for anyone to cross,” Henize said. Seeing that there were people that needed help, Henize and Schaumberg stepped in.
The guides set up a traverse with a rope across the stream. Then, fixing their climbing harnesses to the rope, they began helping people over the muddy, debris-filled water.
“I got to about the last seven feet and I didn’t think I was going to be able to do it,” Parisot said about crossing the traverse. “But as soon as I thought that, I heard the sweetest little voice go ‘you’re almost there, you got it’. That was just what I needed to hear in that moment.”
The voice belonged to Schaumberg, who was helping the hikers cross. Thanks to the willingness and expertise of her and Henize, all of the hikers successfully made it across the stream and back down the mountain with only cuts, scrapes and an exciting story.
While the event that trapped the hikers on the Heliotrope trail was relatively minor, sometimes alpine flooding can be catastrophic. In 2012 a rock and ice fall triggered a flood that killed roughly 70 people in Nepal. An even more extreme example is a glacial lake outburst flood that occurred in Peru in 1941 and killed thousands in the nearby town of Huaraz. These floods occur when a lake formed by glacial meltwater suddenly releases water downstream, usually due to a landslide or avalanche.
One of the greatest challenges when it comes to determining any of the effects of climate change is that most environmental phenomenon, from glacial floods to hurricanes, already occur naturally. It’s tough to correlate any one natural event to climate change. However, one thing that’s certain is that increasing climatic temperatures are causing glaciers to both shrink and become more volatile.
Here in Whatcom County, Mount Baker’s glaciers have retreated an average of 14 percent since 1984, according to research by Mauri Pelto, director of the North Cascades Glacier Climate Project. Out of the 47 glaciers Pelto’s project monitors, four of them have disappeared entirely.
While the cause of the flooding that trapped Parisot and other hikers that day remain speculative, it’s well documented that increasing temperatures are causing profound changes to glaciers.
With those changes comes the potential for more encounters with hazards, like the flooding that trapped Parisot.
As Byers noted, “Glaciers do funny things, and it’s not at all uncommon for people to have an experience like this.”
