Yosemite's Lyell Glacier On The Brink - One Of CA's Last Glaciers & One Of Its Best-Tracked

1883


2018

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Stock poked around in the grass for another pile of rocks, which marked the spot where, in 1883, a geologist named Israel Russell looked 4,000 vertical feet up to the jagged summit of Mount Lyell, 13,114 feet above sea level and the tallest peak in Yosemite National Park. Standing right there, Russell took the first known photograph of the Lyell Glacier, which John Muir had found only 12 years earlier. In Russell’s photograph, 13 million square feet of ice spread like a white shawl across Mount Lyell’s black metamorphic shoulders.

Geologists and park employees have been returning to Russell’s photo point — and to the glacier itself — on a more or less regular basis ever since, replicating Russell’s images to create a scientific record 135 years old and counting. Stock has been the keeper of that tradition for over a decade, making the trip through Lyell Canyon more than 20 times to check the glacier’s vital signs. He has put gauges in runoff streams to measure meltwater trickling out of openings at the toe of the glacier. He has studied data from NASA’s Airborne Snow Observatory, an airplane outfitted with advanced sensing equipment that calculates the water volume in the Sierra snowpack and ice fields. Using much of the same technique that Muir did in 1871, Stock drove stakes into the Lyell to measure the downslope creep of ice that defines a glacier.

Like everyone who has ever studied the Lyell — and pretty much everyone who has ever studied any glacier — Stock documented shrinkage. The Lyell has lost depth and retreated upslope and broken into a smattering of white Rorschach blots that, as of 2014, amounted to about 3 million square feet of ice. In 2012, Stock had collected data showing that the main lobe of the Lyell was not flowing downhill. The pleasure of working in that quiet alpine sanctuary kept him coming back in a spirit of optimism. Still, when Stock looked through his camera’s viewfinder at the largest of the Lyell’s remaining white blots, in 2014, he was surprised to see that a familiar dark patch had grown much larger.

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Nothing in Stock’s professional life has prepared him to be the man who presides over the last days of a glacier, much less the end of an entire geological epoch in which glaciers have come and gone. “I suppose I was a little naive, thinking geologists didn’t have to deal with this,” he admits. “I’ve started to interact with geologists around the world, scientists who’ve dedicated their lives to studying glaciers and ice fields, and it’s tough for all of us to realize that we’re studying a system in decline, the demise of the cryosphere, that frozen part of the world.” In bedtime discussions with his wife, Stock says, “She’s reminded me that all it would take to restore the glaciers would be a change in the climate — more snow and cold enough temperatures for it to pile up. My response is, ‘Tell me when we’re going to have the next ice age.’ I feel like she’s lucky in that she and other biologists can be more hands-on in fighting to restore a species. I feel sort of helpless.”

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https://story.californiasunday.com/lyell-glacier-yosemite