Teams of scientists sailing to examine the “Doomsday Glacier” in Antarctica are having trouble getting there.

A large iceberg broke off the deteriorating Thwaites Glacier and, along with sea ice, it is blocking two research ships with dozens of scientists from examining how fast its crucial ice shelf is falling apart.

The scientists are part of an international effort to study the Florida-sized glacier by land, sea and below for the brief time the remote ice is reachable during the Antarctic summer.

Plans to examine the glacier’s crucial ice shelf have not been stopped but have been slightly sidetracked, officials said.

Scientist David Holland on the Dotson ice shelf in Antarctica
Scientist David Holland on the Dotson ice shelf in Antarctica (David Holland via AP)

This was the last of three international scientific expeditions aimed at the vulnerable ice shelf, said British Antarctic Survey geophysicist Rob Larter, chief scientist of the first research mission.

New York University environmental scientist David Holland, who planned to drill deep through the Thwaites ice shelf to measure the water’s warmth below it, is achingly close but not quite there.

Improvising, Mr Holland decamped at the nearby Dotson ice shelf to do his research where no human had been before.

He is hoping that along that blinding white ice and its rugged frozen cliffs he can learn about the unseen warm ocean water nibbling away at both Dotson and Thwaites from below. The smaller Dotson ice shelf is about 87 miles west of the Thwaites ice shelf.

The ice shelf “is the most important part of Thwaites and it’s protecting itself and hiding from us”, Mr Holland said in a first video interview from the Dotson ice shelf.

A satellite image from the European Space Agency, annotated by marine geophysicist Robert Larter, showing the positions of research vessels in Antarctica
A satellite image from the European Space Agency, annotated by Robert Larter, showing the positions of research vessels in Antarctica (Robert Larter/British Antarctic Survey, ESA via AP)

He called Dotson’s ice shelf “this beautiful white desert-like landscape, brilliantly white actually. And it will all be gone and replaced by the Pacific Ocean in due course”.

“Nobody can get to Thwaites this year,” Mr Holland told The Associated Press. “We tried to cut through it for a week. Couldn’t do it. So we’re next to it.”

Thwaites is spawning more icebergs as it is falling apart, Mr Holland said.

This iceberg used to be the tongue or leading edge of Thwaites until it broke off about 20 years ago, Mr Larter said.

It measures about 43 miles by 28 miles, almost the size of Rhode Island, according to the National Snow and Ice Data Centre.

Much of the problem is that loads of sea ice have gravitated around the huge iceberg. And that is ironic — and troublesome for researchers — because overall Antarctic sea ice is unusually low for this time of year, Mr Larter said.

The key to the future of Thwaites is the ice shelf and its tongue. These edges with warm water underneath border the ocean and provide “back support” that holds the rest of the glacier in place, preventing it from falling into the sea, Mr Holland said.

What worries scientists is that leading edge of the huge glacier is breaking apart in many places. Even though total collapse of the glacier could take hundreds or thousands of years, the edge is falling apart much sooner. And if that goes, researchers fear nothing may stop the rest from doing the same.

“I think the ice shelf will be gone in a matter of years to decades,” Mr Holland said. “But the actual inland ice, that’s the really unknown question.”

If all of Thwaites collapses, it could raise seas around the globe more than two feet but that could take hundreds of years, scientists say.

“Ultimately over time it’s going to rewrite the global coastline,” Mr Holland said.

While places like Greenland — where in 2019 Mr Holland studied the melting Helheim Glacier — are melting from warm air above, Thwaites and its neighbouring glaciers have it worse because they are melting from the warm water below the ice, which acts faster, Mr Holland said.

Equipment set up on the Dotson ice shelf in Antarctica
Equipment set up on the Dotson ice shelf in Antarctica (David Holland via AP)

Part of that is natural weather variations but on top of that climate change is playing a role, he said.

Computer models show that greenhouse gases from the burning of fossil fuels “are tilting the winds in a way that’s bringing more warm water south”, Mr Holland said.

That warm underground ocean water is what Mr Holland came to study with plans to drill hundreds of feet down and put sensors below the ice in the pools of warm water.

University of Washington ice scientist Ian Joughin, who is not part of the research consortium, cautioned that while Thwaites is a big concern, especially the collapse of giant ice cliffs, the earliest his computer simulations show that happening is 200 years from now.

“We need to take these glaciers seriously without sounding like Chicken Little,” Mr Joughin said.