Navigating Mount Rainier's deadly ice caves for science

This team crossed invisible lakes of noxious gas to map the mountain's mysterious caves and search for clues to life on Mars.

How far would you go in the name of science and exploration? A team of cavers and researchers studying Mount Rainier’s curious network of glacier ice caves found out their answer after a permit rejection from the National Park Service.

The Mount Rainier Fumarole Cave Expedition team had requested permission to use a helicopter to shuttle 1,800 pounds of scientific, safety, medical, and expedition equipment to a camp at 14,250 feet. They needed the gear, which included small components that may one day be used in a Mars-roving NASA ice-climbing robot, to land at a volcanic crater just beneath Rainier’s summit. The Park Service, however, denied the helicopter request based on the need for an environmental-impact study.

Instead, Eddy Cartaya, a leader on the team, turned to old-fashioned 19th-century mountaineering tactics to get their gear to the top of the mountain.

Undeterred by 21st-century bureaucracy, Cartaya turned to old-fashioned 19th-century mountaineering tactics to get their gear to the top of the mountain.

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Expedition doctor Woody Peebles explores a previously unknown portion of a Mount Rainier cave.

In late July 2017, over 100 people—mountain rescuers, cavers from the National Speleological Society, and other locals—volunteered themselves to porter the equipment from the parking lot to the summit of the Cascades’ preeminent peak.

Adventure Atop a Volcano

Mount Rainier dominates the region’s landscape. It has a topographic prominence—the height it rises relative to the surrounding topography—of 13,210 feet, which is greater than that of K2. Ascending its heavily glaciated slopes takes most climbers two to three days, and by the time they reach the summit, they’re typically wrecked from the exertion and altitude.

“It’s all most climbers can do to snap a photo and run the hell down. No one in their right mind really would ever want to go up there and spend 10 days,” says Cartaya.

For Cartaya and his team, Rainier’s summit is the starting point for the real adventure. Deep within the glacier plugging the summit crater are the fumarole caves, a network of tunnels and chambers 2.2 miles long and 465 feet deep, carved into the ice cap by the slow release of fumarolic steam and gases from the belly of the mountain.

“It's terrible to be up there for so long,” says Cartaya. “You're always cold. You're always tired. You always feel sick. You’re exhausted. It really sucks. But everyone's excited because they're so passionate about doing this work and sharing it together as a team. It's this bizarre kind of elation, I guess, to be part of something like that.”

First explored by Seattle-based caver Bill Lokey in the early 1970s, Rainier’s fumarole caves haven’t been meaningfully surveyed or studied until now.

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Eddy Cartaya climbs down an ice wall with the help of James Frystak, placing ablation markers to measure the melting ice over time.

The goals of this multi-year expedition, slated to wrap in 2020, are to complete a three-dimensional survey of two cave systems in the ice cap and conduct geo-microbiology, geochemistry, and climatology studies.

Entering the caves, however, carries its own unique and extreme risks.

Invisible Killer Lakes

Invisible and odorless “lakes” of relatively heavier carbon-dioxide gas, released by the fumaroles, form at the bottom of pits and dead-end tunnels. These CO2 lakes represent one of the caves’ gravest dangers, forcing expedition members to carry CO2 monitors and re-breathers that would provide the 20 minutes of air needed to escape.

Exploring Toxic Ice Caves Inside an Active Volcano

"The caves themselves are very complex with hazards deep inside. The recipe is set for a cave rescue with a lot of dire consequences," says Eddy Cartaya, a National Geographic grantee leading an expedition into Mount Rainier's ice caves. With a background in search and rescue, Cartaya hopes that his team's data will help protect the thousands of people who attempt to climb Mount Rainier every year.

Already, the team has experienced close calls. During the 2017 trip, Christian Stenner, a Canadian caver, slipped and fell down a steep passage in one of the bore holes near the summit of Rainier. Giant boulders tumbled alongside him as he fell.

He came to a stop where the passage dead-ended and was fortunately unhurt. He was having trouble breathing, which he initially attributed to being shaken by the fall, but soon realized he was in a CO2 trap.

“I had a feeling of panic and a moment of impending doom,” says Stenner. “I knew I wasn’t getting enough air, and I felt like I was going to drop.”

Stenner hastily clawed his way back up to his teammate, where he composed himself, and ultimately the two managed to escape the cave before passing out.

In another incident, Cartaya himself experienced the surreal “chemical suffocation” of being in a CO2 trap. He says, “I remember feeling a sense of impending doom, just like someone's got a bag over your head. It's very scary feeling.”

Knowing the dangers of the CO2 in the caves, the team has worked to mitigate their risks with safety measures and protective equipment.

The Science Goes On

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Scientists Andreas Pflitsch and David Holmgren work to place a probe that measures temperature and depth at the bottom of Lake Adelie.

The Mount Rainier Fumarole Cave Expedition team has more than one goal. The geographical surveys will help in both mapping and future search and rescue efforts, as climbers have been known to duck into the caves to wait out bad weather. The scientific studies will help researchers understand the complex formation processes of the caves and model the ablation of the glacier.

There’s also an effort by Dr. Penny Boston, the director at NASA’s Astrobiology Institute, to study the geo-microbiology of the caves. Tiny, rare organisms broadly classified as “extremophiles” are living in these incredibly harsh environments, feeding off of the noxious gases released by the fumaroles. These environments could serve as models for life in places like Mars, and some of the experiments on Rainier may help further the development of an ice-climbing robot designed to collect these kinds of samples on Mars.

“It’s a huge source of satisfaction that we're furthering science and facilitating these academic discoveries to make a holistic representation of the cave,” says Cartaya.

Next year, Cartaya and his team are hoping to bring up a number of anemometers, expensive and extremely fragile devices that measure air flow, temperature, and other data. Cartaya, however, remains optimistic that his team will be granted a helicopter permit in 2019 to help them shuttle the delicate equipment.