IU geologist to continue study of Mount Rainier's ice caves

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IU geologist Lee Florea, left, and National Park Service ranger Tabbatha Cavendish examine mud samples from an underground lake within an ice cave on Mount Rainier. FX De Ruydts

When many of his colleagues are enjoying the end of their summer vacations, Indiana University geologist Lee Florea will be lugging a 65-pound pack up the slopes of 14,410-foot-high Mount Rainier and spending a week doing intensive research in one of the most inhospitable environments on Earth.

Florea, assistant director for research at the Indiana Geological and Water Survey at IU Bloomington, is part of a team working on the Mount Rainier Fumarole Cave Project, a multiyear effort to map and study the extensive system of ice caves under the glaciers on the mountain.

The caves result from fumaroles, vents that release steam and hot gases that rise from deep within the volcanic mountain and sculpt elaborate caverns at the base of the glaciers in the twin summit craters.

The project, which includes researchers from several institutions in the United States and Germany, seeks to gain a better understanding of the workings of Mount Rainier, an "episodically active" volcano that experienced its last significant eruption about 1,000 years ago. The scientists plan to spend a week in early August investigating the caves, collecting samples and conducting measurements.

"These data are useful for understanding the dynamics of the glacier and the volcano and how they are in equilibrium with each other," Florea said. "This study can help us understand whether the changes we see result from climate change or from changes in volcanic activity."

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Expedition member James Frystak in the main passage of an ice cave during the 2015 research trip. FX De Ruydts

Climbers discovered the fumarole caves in the late 1800s, but little was known about them beyond the fact that they existed. Explorers made attempts at mapping the caves in the 1950s and 1970s, but the harsh conditions restricted the work. Only recently have scientists acquired the tools to attempt sophisticated analysis of the forces that created and maintain the caves.

"The mountain has been studied, but there's been very little work done in the caves, and it's really hard to get work done there," Florea said.

The research project began with a preliminary investigation in 2014. Florea, then a faculty member at Ball State University, joined the following year, bringing expertise in geochemistry and geomorphology. An avid caver who has visited and surveyed caves in 30 U.S. states and in Europe, Asia and the Caribbean, he said that working in the Mount Rainier caves is a different experience.

Extreme and unpredictable weather can present serious challenges, even in mid-summer. The climb is steep and treacherous; glacier crossings, crevasses, and avalanches, storms and strong winds present real dangers. The air is thin, and breathing can be difficult. Project members and multiple teams of volunteer porters climb with heavy packs, carrying scientific equipment along with supplies and material for a week of frigid-weather camping.

"Getting up there requires a Herculean effort. And to add multiple days of science, it's just really hard," Florea said. "The climb is no walk in the park. There's a path, but it's almost vertical in some areas. You're in mountaineering gear, and you have to cross crevasses on ladders and with ropes."

The payoff is working in ice caves of unearthly beauty and attempting to reveal important information about the volcanic mountain and its 25 glaciers, the most of any mountain in the contiguous United States. It involves studying water flow, water chemistry, the changing thickness of ice and the communities of microorganisms that survive in an extreme environment.

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Lee Florea climbs Mount Rainier during a previous research expedition. James Frystak

Florea's focus is on water and ice, including analysis for trace levels of radioactive chlorine and iodine, isotopes of hydrogen and oxygen, and gases such as helium that can be used to determine the source and age of water in the caves. Moisture in the caves can obviously come from melting snow, Florea said; but it could also come from inside the volcano, where the subduction of tectonic plates that created the Cascade Mountains would have introduced seawater from the Pacific Ocean.

In addition to taking measurements and collecting new samples, he hopes to retrieve information from a datasonde, an instrument that he placed in the cave last summer and that has recorded readings for water level, temperature and conductivity at 15-minute intervals.

"The hope is that I can download that data and look at it for seasonal patterns, for 'burps' of volcanic gas and so forth, to gain information about changes related to the seasons or volcanic activity," he said.

Mount Rainier's glaciers cover 35 square miles but have been melting at an ever-faster pace, possibly because of climate change, scientists say. But the interplay of snowfall, climate and volcanic forces creates a complex puzzle for researchers to study as they ask what the ice caves can reveal about how Mount Rainier is changing and what to expect in the future.

Funding for the research comes from National Geographic, the Mountain Rescue Association, the Mazamas mountaineering education organization and the Petzl outdoor equipment company. Numerous business and organizations sponsor the project.