Taking the Pulse of Montana’s Melting Glaciers
Scientists hike to retreating ice to discern its fate.
The last obstacle in the 10-mile climb to Sperry Glacier--a 4,800-foot elevation gain--is a rock stairway cut in the raw stone, called "The Staircase." The ordinary name underplays the severity of the ascent. It has the exposure and verticality of a fire escape on a New York skyscraper. The steps are set in a triangular corner, which reaches up to a lofty window in the last 200-foot-high bench below the glacier. Mercifully, a cable railing is anchored to the rock. My right hand clenches it until knuckles rub raw. But there's no alternative. It's the only way to the window at the top.
The Staircase is precarious in the best of conditions, but rain or snow makes the limestone slick and treacherous. Today, nature's cruel joke is the wind. A forty-mile-per-hour burst of air tears through the vertical chamber, seemingly from all sides, as if the skin were being flayed off the building. The rock wall must be ricocheting the breeze: It's hard to make out its origin. The wind makes me more careful. Every step--there are 30 to my count--requires hefting my foot cautiously and, with one hand on the cable and one hand on my trekking pole, rolling my gait upward into the dark stairwell. Halfway up, my legs feel as heavy as waterlogged timber. But each new step brings me closer to heaven: Sunshine bathes the top of the chute.
Dan Fagre and his team of two--Kevin Jacks, forty, and Erich Peitzsch, 33--arrive two days later with impressive packs of gear, impressive not so much for their bulk as for the lethal accessories tied on top: ice axes, crampons, ice screws, and ropes. It is a tight squeeze through the Staircase--like threading the eye of a needle. A snag would be dangerous, but the three men slip through and break free cleanly.
Dropping their heavy packs, the men rearrange their equipment, getting set to make their rounds. From the beginning, field notebooks at the ready, it is clear the diagnostic work will be nothing like that of Grinnell Glacier. Here, Fagre must listen to the glacier more closely.
But first: precautions. To combat the threat of hidden crevasses, the three men don climbing harnesses and tie up to a fifty-meter, blue-and-green perlon rope. They attach crampons to their boots and arm themselves with ice axes. In case one of them falls into a crevasse, each man has ascenders to climb the rope back up to his comrades. The scientists will navigate the snow with half a rope length between each man. It will be critical that the line is taut. Tension on the line will detect a fall quickly-- like a quiver. If there is a fall, the second man will drive his axe into the ice deck, and the lower man will climb up the rope and out. That's if everything goes according to plan, but mountains sometimes have schemes of their own.
Before tackling the ice, the men are curious to check on their weather station, a remote listening post running since 2006. It sits on the prow of the rock rib just above the men, tethered to the rock. Resembling a lunar module, though even more compact, the station operates with only minor maintenance as long as the snow doesn't cover its solar panel. Snowfall can exceed thirty feet at Sperry. Thus, it shuts down each winter until late spring. But all summer long it senses and stores data on temperature, relative humidity, solar radiation, and wind. The solar panel recharges a car battery that runs the whole thing.
Fagre says, "We put the station here, carrying the works on our backs, to see if any weather conditions were different at this glacier. In a few more years, we'll have enough data to make a judgment. Maybe it's colder here than at similar places in the Park where there's no ice. Maybe it gets less sun. That would help explain why Sperry exists."