Imminent Collapse of Doomsday Glacier’s Massive Ice Shelf: What You Need to Know

The front ice shelf of Thwaites Glacier is on the brink of collapse, increasing the instability of Antarctica’s most vulnerable glacier.

“Its imminent demise could occur suddenly, and to clarify, we are preparing an ‘obituary’ press release,” states Rob Larter from the British Antarctic Survey.

Thwaites Glacier, often referred to as the ‘Doomsday Glacier’, is approximately the size of the United Kingdom, rapidly shrinking and currently contributing to around 4% of global sea level rise. Furthermore, its collapse might instigate a domino effect across the West Antarctic ice sheet, leading to an alarming 3.3 meters of sea level rise and reshaping coastlines globally.

Numerous glaciers in Antarctica have ice shelves that float into the ocean, aiding the flow of ice from the continent. This includes the Eastern Thwaites Ice Shelf (TEIS), roughly the size of Greater London (1,500 square kilometers) and boasting a thickness of 350 meters. Recent satellite imagery reveals troubling indications that this ice shelf may soon become detached, with some experts asserting that this separation has already commenced.

“Suddenly, extensive areas were torn apart,” remarks Christian Wilde from the University of Innsbruck, Austria. “It resembles a shattered windshield.”

Significant cracks have emerged around the pinning points (the sections where the floating ice shelf is secured by underwater ridges) and along the grounding line, the area where the glacier transitions into the ocean and begins to float.

“It’s dramatic. I visited in 2019 or 2020, and now when I look at the satellite image, I can’t identify that ledge. There’s a considerable notch where there was none before,” comments Karen Alley, a professor at the University of Manitoba in Canada, who is examining how this divide might progress.

The primary cause of these changes is shifts in ocean circulation, which have led to the melting and thinning of the ice. Additionally, alterations in ice flow dynamics mean the shelf is colliding with stable points, causing fractures. “We’re transitioning from a robust, thick ice shelf anchored at specific points to a weakened, thinner ice shelf that’s disintegrating,” Alley explains.

The disappearance of ice shelves is also evident in the speed at which they flow. “From January 2020 to January 2026, the ice flow has tripled to over 2,000 meters per year, which is alarming,” Wilde states. This trend has intensified in the last five months. “We’re essentially in a state of free fall at this point.”

Simultaneously, fresh cracks are appearing along the grounding line. “These have emerged in the past few years as shelf displays have significantly accelerated,” comments Ted Scambos from the University of Colorado Boulder. This indicates that ice shelves are being pulled away from glaciers.

Predicting the exact moment of final breakup is exceedingly complex. “Forecasting ice shelf rupture is akin to predicting earthquakes,” Larter explains. “We recognize an event is in motion, but timing is reliant on unpredictable processes. The next satellite image we receive may reveal ice shelf collapse, but the same could be true next year.”

However, don’t expect a colossal iceberg to float into the ocean immediately. Due to the area’s geography, any detached ice is likely to remain in proximity, and, since TEIS is already so fractured, significant breaks are improbable.

While the dramatic collapse of giant icebergs often captures headlines, glaciologists emphasize that the primary concern lies in the diminishing strength of the ice shelf. Wilde remarks that the shelf is “effectively gone” when it ceases to impede the upstream flow. This results in a quicker movement of glaciers into the ocean.

In an upcoming study, Wilde and colleagues revealed that from January 2020 to 2026, the ice flow of glaciers previously supported by TEIS increased by roughly 33 percent. “There is evident proof that there is little to no buttressing in this region anymore,” he states. This reduction has effectively led to the collapse of the ice shelf.

This poses significant implications for future global sea levels. “Increased ice movement from Antarctica means more ice entering the ocean, contributing to rising sea levels,” Scambos notes, emphasizing that while this is not an immediate crisis, it will slowly unfold, affecting future sea levels over decades. “This will influence how Thwaites evolves and potentially contributes to 10 to 20 percent of future sea level rise.”

By 2067, Thwaites may lose approximately 190 gigatonnes of ice annually according to a January study by Daniel Goldberg from the University of Edinburgh and colleagues. This marks a 30 percent increase over current glacier losses, equating to the total ice currently lost from Antarctica.

While ice shelf break-offs are normal in polar cycles, current loss trends are alarming. “Since the 1990s, we’ve observed increasing instability in ice shelves,” Alley states. Notably, the adjoining Pine Island Glacier is also undergoing rapid changes, and its ice shelf is collapsing.

“Ice shelves remain stable primarily in extremely cold conditions,” Alley adds. “Both ocean and atmospheric temperatures must be low. However, as we warm the planet, we observe the corresponding loss of ice shelves, which is precisely what’s expected.”