Glacier scientist Timothy Bartholomaus swooped over a world of tortured, stretched ice in mid-June. He’d never seen anything like it.
The footage below, captured aboard a helicopter flying over the Turner Glacier in southeast Alaska, shows recently created ice canyons, caves, and leaning pinnacles. It’s twisted, unsettling, warped ice.
“It’s totally wild to see how torn apart this glacier is,” marveled Bartholomaus, a glaciologist at the University of Idaho who has seen plenty of glaciers. “This glacier just seemed threatening.” “It’s totally wild to see how torn apart this glacier is.”
The Turner Glacier did something just 1 percent of glaciers do: It surged. Yes, on a continually warming planet where most glaciers are thinning and receding, some glaciers still have fast bursts of movement forward. This means a glacier suddenly starts moving some 10 to 100 times faster than normal. Turner Glacier, which glaciologists are currently researching, typically moves three or so feet a day. During the surge, it’s advanced around 100 feet every day.
The results are stark. The glacier, a “river of ice,” has been stretched apart in many places, explained Bartholomaus. Turner’s crevasses — cracks that normally form on glaciers — have become precipitous canyons, some 100 feet deep, or more.
Turner Glacier surges on a schedule, around every six years. Knowing this, Bartholomaus and his team placed sensors on and around the glacier in August 2020, to learn more about why surges happen and to better grasp the behavior of glaciers generally (including Antarctic glaciers capable of creating catastrophic amounts of sea-level rise). Last summer, the surge had just started. When they returned in June 2021, the glacier transformed.
“It’s like coming upon a crime scene,” said Bartholomaus. “What happened here?”
The reason relatively few glaciers surge isn’t well understood. Glaciologists largely agree that surging involves water getting trapped under the ice, creating a more “slippery” environment below. But why this water gets trapped, and how a glacier rapidly starts and stops, are big, looming questions. The researchers’ seismic sensors, which measure ground motion, will better reveal what’s happening around and under Turner Glacier. “You can’t just open up the hood of a glacier and look,” noted Bartholomaus.
On a heating globe, which will continue to warm for at least decades, it’s possible surges may eventually become less common. Many glaciers, continuously melting, will have less ice to surge with.
“At some point…a warming climate will undermine the ability of surge-type glaciers to build an ice reservoir, so we should expect fewer surges in the long term,” Gwenn Flowers, a glaciologist and professor at Simon Fraser University in Canada, told Mashable in April after another Alaskan glacier (the Muldrow Glacier) started an impressive surge.
For now, Turner Glacier is dramatically surging. Standing near the glacier, Bartholomaus and his team recently listened to crashing blocks of ice.
“We could certainly hear it falling apart,” said Bartholomaus.
