Failure, Data, and the Slow Truth of Thwaites
Even when the drilling stops, the science—and the stakes—keep moving beneath Antarctica’s most consequential glacier
[My final PBS News Hour story from the Thwaites Glacier is embedded above]
The timing was awkward. New York University glaciologist David Holland and I landed on the surface of the Thwaites Glacier almost precisely when the expedition’s central goal—boring through three thousand feet of ice to install instruments in the ocean below—reached an unceremonious dead end.
For weeks, a determined team from the British Antarctic Survey and the Korea Polar Research Institute had battled bad weather, lethal terrain, and a tight timeframe to melt a narrow shaft to the hidden boundary where glacier, land, and sea meet. The plan was elegant and ambitious: leave behind sensors that could watch the ocean beneath Thwaites for perhaps a year, transforming a fleeting glimpse into enough data to understand the processes driving the relentless erosion of this icy leviathan.
Instead, the borehole closed in before the instruments could splash down in the Amundsen Sea.
Still, Holland was on a mission to install a Distributed Temperature Sensor (DTS) designed to measure continuously from surface to seafloor. With the hole shortened by refreezing ice and clogged with sensors, like a snarled pileup on the foggy interstate, the cable would fall about 650 feet short of the ocean it was meant to measure.
I asked him why he wanted to bother. Why accept half a loaf, which is really no loaf at all - in this binary business?
“It shows the possibility of what we can do in terms of remote instrumentation,” said Holland. “It would be sugar coating to saythat’s really great, but that’s better than nothing.”
As it turns out, I was better than nothing when it came time to install the DTS.
Holland asked me to give him a hand. As an arm amputee, it is literally all I have to offer. Suddenly, tragedy turned to comedy. Lucy and Ethel came to mind. We began toting the heavy equipment - a huge toolbox, a dozen car batteries, and a Starlink terminal among them.
All of this will remain on the surface connected to the fiber optic cable that went down the hole. A transmission tower should ensure this data will be transmitted on a regular basis. Everything works. But without readings of the ocean, it doesn't amount to much scientifically.
Holland didn’t soften the verdict. What they achieved, he told me, was “nothing… absolutely nothing,” a result he described with a hint of dark humor as “a little bit Shakespearean.”
Science that didn’t get holed up
The failed drilling was the marquee event of a month-long international campaign launched from the Korean research icebreaker Araon. But it was never the only science happening here.
A helicopter spent days flying long, chalk-line-straight surveys across the glacier, carrying a deep-penetrating radar capable of mapping hidden structures within the ice and the terrain beneath it. Over six flight days, the team recorded more than 1,800 miles of data—high-quality coverage that will help scientists refine models predicting how quickly Thwaites could retreat.
Those models matter because the glacier’s vulnerability lies not only in melting but also in what happens once the friction beneath it disappears. The glacier sits below sea level, and it is downhill all the way to the South Pole. The terrain near the grounding line is rugged - with a lot of natural “speed bumps” built in - but farther inland, it flattens out. Once the ice gets over the hump, there’s nothing to stop it from a runaway collapse.
Sea Ice at its Core
On the surface, other scientists worked at smaller scales to answer equally large questions. Sea-ice researcher Siobhan Johnson of the British Antarctic Survey drilled cores of firn—snow transitioning into ice—to measure density and track melt layers that reveal recent warming. She also spent a lot of time sampling sea ice - that is, frozen ocean.
In the Arctic, sea ice is declining rapidly—its volume has fallen by roughly 70 to 75 percent over the past five decades. But Antarctic sea ice held steady or even grew slightly until 2016, when it began a sharp, unexpected decline as the climate crisis reshaped wind and ocean currents.
Melting sea ice does not directly raise sea level, since it is already floating. But its loss can indirectly accelerate the melting of land ice - glaciers like Thwaites.
Meanwhile, oceanographers deployed moorings, sampled water chemistry, and launched an autonomous underwater glider to profile temperature and salinity through the water column. Each dataset is small on its own—together, they begin to sketch the invisible system driving Thwaites’ retreat.
Into the rifts
Some of the most novel science happened where the glacier is already breaking apart.
Polar geophysicist Jamin Greenbaum of the Scripps Institution of Oceanography at UC San Diego teamed up with helicopter maestro Dominic O’Rourke to fly into ice canyons on a series of daring missions.
They used a helicopter-delivered instrument called RIFT-OX to lower sampling canisters nearly 2,800 feet into fractured ice canyons. The goal: detect subglacial discharge—freshwater formed beneath the glacier by geothermal heat and friction, then injected into warm ocean water where it can intensify melting.
Greenbaum told me he thinks of the warm ocean currents beneath Thwaites as a fire. “And this subglacial discharge, I like to think of it like lighter fluid,” he said. “It’s getting sprayed into the fire, and it just blows the whole thing up.”
Greenbaum’s early measurements found exactly that signal where theory predicted it should be.
It’s a small confirmation in a vast system—but in Antarctica, small confirmations matter. There simply isn’t that much data to begin with. Any morsel is welcome.
Moving slower than the glacier
But for all this effort, the data morsels remain fragmentary.
Korea’s Polar Research Institute plans to return in two years, possibly to drill down once again. In addition to their failure this year, they were unable to drill at Thwaites in 2022 when a thick jam of sea ice prevented them from even reaching the glacier. So maybe the third time will be a charm.
The glacier is moving 30 feet a day as it collapses (giving new meaning to the term “glacial pace”), outpacing the scientific efforts to understand it. The stakes really could not be higher. Thwaites and the other ice shelves it supports, like a keystone, store enough water to raise global sea level by 10 feet. Talk about a phase change!
And yet the Koreans are all but alone in their effort to focus on it. The Trump administration has eviscerated the National Science Foundation and its Antarctic science enterprise. The US no longer even has a research icebreaker thanks to the draconian, shortsighted cuts to federally funded science.
As the US retreats, the world owes a debt of gratitude to the Koreans for taking a bold leadership role on such an important mission.
Perhaps the best way to show our thanks is to step up and support them. They will keep coming, but so should we all.
Thank you for sharing the story of Thwaites. It is important science, and I believe the U.S. will return to its role in research and discovery of our marvelous planet. If we don't all drown first. Keep the faith.👏✌🌟