Attempt to Drill Through Thwaites Glacier Is Foiled

Scientists lost their instruments within Antarctica’s most dangerously unstable glacier, though not before getting a glimpse at the warming waters underneath.

A daring attempt to study Antarctica’s fast-melting Thwaites Glacier collapsed over the weekend after the scientists’ instruments became entombed within the half-mile-thick ice.

A team of British and South Korean researchers was trying to install instruments beneath the immense glacier, where they would collect data, the first of its kind, on the warm ocean waters that are melting away the ice at a rate of hundreds of feet per year.

Scientists fear that if Thwaites sheds too much ice, it could cause more of the vast West Antarctic ice sheet to start sliding rapidly into the sea, swamping coastal communities worldwide with as much as 15 feet of extra water over the coming centuries.

The team of 10 scientists, engineers and guides camped for more than a week on Thwaites to set up their complex operation. They used a jet of water heated to 80 degrees Celsius, or 176 degrees Fahrenheit, to melt a hole through the glacier, one foot in diameter and roughly 3,300 feet deep. They then lowered instruments to gather data in the water beneath the ice.

The clock was ticking: The tiny hole would refreeze in about 48 hours unless the team kept shooting hot water into it. And bad weather was on the way. If the scientists didn’t finish by Monday, the helicopters on their research vessel, the Araon, might not be able to fly the team members and their many tons of gear off the glacier before the ship leaves Antarctica around Feb. 7.

The final stretch

Early Saturday, the scientists collected preliminary measurements with a small suite of instruments that they sent through the borehole and pulled out again. They then lowered nearly 3,900 feet of cable bearing another set of instruments that would remain in place for one to two years.

But those instruments only made it about three-quarters of the way through the ice, never reaching the water under the glacier. A project almost a decade in the making had crumbled at the final stage.

“Absolutely gutting” is how Keith Makinson, an oceanographer and drilling engineer at the British Antarctic Survey, described it. “You get your window of opportunity. You don’t have forever. And you see what you can do.”

In the end, it was not impenetrable Antarctic sea ice, abysmal weather or finicky equipment that denied these scientists their triumph. It was some combination of these factors and more, working together to rob the team of that most precious resource for any endeavor in the unforgiving polar wilderness: time.

There just wasn’t enough time to try again.

Still, the researchers are not leaving Thwaites empty-handed. The preliminary data they collected on Saturday is the first ever gathered from beneath the glacier’s fast-moving main trunk. The data shows that the waters underneath are turbulent and warm, and indicates that there is much to be understood before scientists can predict with confidence how soon Thwaites might go to pieces.

“This is not the end,” said Won Sang Lee, the expedition’s chief scientist. The new data confirms that “this is the place to go, whatever challenges there are,” he said.

Those challenges started coming well before the team unreeled the doomed cable on Saturday. Whipping winds last week delayed the start of hot-water drilling by a day. After work began, the researchers discovered they had bored through gaping crevasses.

On Friday, the depth gauge on their drilling system started giving faulty readings. And, that night, after tunneling through the bottom of the glacier, the hot-water drilling hose got stuck in the borehole as the team was pulling it out.

“It’s been a fight every step of the way, this one,” Peter Davis, an oceanographer, said as his colleagues tried to wrest the hose free. They finally succeeded at around 1 a.m. on Saturday morning.

The hose might have gotten trapped because the ice around it shifted, Dr. Davis said. Thwaites’s main trunk is sliding toward the sea at a rate of more than 30 feet a day, causing the glacier to stretch and crack. The researchers had been hearing booms beneath their feet all week.

At around 1:30 a.m., the scientists sent a camera down the hole. They didn’t see major obstructions, so Dr. Davis said they should start sending down scientific instruments right away.

They lowered a camera and several oceanographic devices, first through the glacier and then through the roughly 850 feet of ocean underneath. Then they reeled the instruments up through the water again, down and up five times in total. Yixi Zheng, a postdoctoral researcher, watched on her laptop as the data rolled in.

“The temperature is really high in this place,” Dr. Zheng said, studying the squiggly lines on her screen. In the seas around Thwaites, the scientists had recorded water temperatures of 1.1 to 1.3 degrees Celsius, or 34 to 34.3 degrees Fahrenheit, similar to what they were now seeing under the glacier. “But still, it’s so far away from the open ocean. Having this temperature is crazy.”

“There’s plenty of heat to drive melting,” Dr. Davis said.

Because these first instruments had gone through smoothly, the scientists decided to move ahead with their final task: installing the mooring that they would leave under Thwaites. The data collected by the moored instruments would be transmitted daily, by satellite, to the scientists back at their laboratories.

The first part of the mooring to go in was a rusty chain, weighing nearly 190 pounds, that would hold everything steady in the water. As the rest of the team helped unspool cable, Dr. Davis and Scott Polfrey, a mechanical engineer, stood above the borehole and attached instruments one by one as the cable went down.

“See you on the flip side, instruments,” Mr. Polfrey said, as the first pieces of equipment disappeared into the hole.

For the next four and a half hours, the team fought through yawns, brain fog and growling stomachs to install the mooring.

Shortly after 1 p.m., the cable had at last been reeled out to the desired length, and Dr. Davis knelt in the snow in front of his laptop to communicate with the instruments and see where they were.

He typed a bit and peered into the screen. He got up to fiddle with the wiring on the mooring cable. Then he knelt back down at his computer.

More typing. More peering. Finally, he lifted his head.

“I think it might be stuck.”

He radioed Mr. Polfrey, who was waiting at the controls about 200 feet away. He asked for the cable to be lowered, to see whether the instruments’ depth readings might change. Mr. Polfrey obliged. No luck.

Dr. Davis looked stricken. Dr. Zheng held her face in her hands.

“Realistically, whatever’s stuck there is frozen,” Dr. Makinson said.

At first, Dr. Davis thought a piece of ice might have broken off while the instruments were being lowered, pinning them partway through the hole. Then, he and Mr. Polfrey looked at the data on the amount of weight the cable had been supporting as it was being unspooled. It had fallen abruptly at one point, by 50 kilograms, or 110 pounds. What could have taken off such a big load?

After a moment, the answer came to Dr. Makinson. It might have been the rusty chain at the bottom. Somewhere in the hole, the walls may have refrozen enough that the bulky chain didn’t fit through, and the rest of the mooring simply piled up on top of it.

The researchers tried to break the ice’s grip by hauling up the cable.

“I suspect we’re not going to get very far,” Dr. Davis said.

“Let’s try,” Mr. Polfrey said.

Time to retreat

Dr. Davis trudged off across the snow, not saying anything. After a few paces, he stopped and bent into a crouch, staring off into space.

Taff Raymond, one of the team’s field guides, knelt beside him and put a hand on his shoulder. Dr. Davis rose and rubbed his eyes. “Let’s get this done,” Mr. Raymond said.

It took just 20 minutes of trying for the team to realize it was hopeless.

Dr. Lee, the chief scientist, conceived of this project nearly a decade ago, in 2017. It took years to pull together funding and gather a team with the British Antarctic Survey. On the group’s first attempt to drill through Thwaites, in 2022, the scientists never made it onto the glacier. Thick sea ice stopped the Araon from sailing close enough for the helicopters to fly the gear onto the ice. This time, the team got much further.

What motivated Dr. Lee to keep trying? South Korea started its polar science program later than Western countries, he said. Slowly, the nation has built up its research capabilities: It nurtured scientists, built the icebreaker Araon, established two Antarctic bases. All it needed was an achievement to set it apart.

“I wanted to find something unique that we could do and someone else cannot,” Dr. Lee said. Even if he and his team didn’t quite prove that this season, they had learned enough to keep trying, he said. “If you lose momentum, then it’s really hard to go back in the race.”

There wasn’t much time to ruminate on Saturday afternoon. The Araon’s helicopters had to start slinging cargo back to the ship the next morning. Piece by piece, the drilling camp was taken apart. Cables were coiled, hoses unplugged.

The power generators were switched off, and, for the first time in days, the glacier was silent.

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