As one of nature’s most dramatic warning signals, Thwaites Glacier has earned its ominous nickname for good reason.
This unusually broad glacier in the Antarctic has been severely affected by climate change and is now under constant scientific scrutiny. Hidden beneath it lies a vast cavity, and researchers warn that its collapse could significantly elevate global sea levels.
Some theories suggest it could destabilise with relatively little warning – an outsized danger that has led to its ‘Doomsday Glacier’ moniker.
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What is the Doomsday Glacier?
Thwaites Glacier is the widest glacier on Earth, reaching approximately 80 miles (120 kilometres) at its widest point. While it’s not the largest glacier of its kind, it’s considered to be one of the most remote, rapidly changing and unstable glaciers found in the Antarctic, according to the British Antarctic Survey.
According to the International Thwaites Glacier Collaboration, the Thwaites Glacier Basin measures 74,000 miles2 (192,000 kilometres2), making it larger than the US state of Florida (which has an area of 170,000 kilometres2).
It’s between 800 and 1,200 metres (0.8-1.2 kilometres) deep at its grounding line.
Thwaites Glacier is undergoing the largest changes of any ice-ocean system in Antarctica. In 2019, NASA discovered an underwater cavity under the glacier, which is 300 metres tall and two-thirds the size of Manhattan. It is estimated to have once held 14 billion tonnes of ice, which has now melted and contributed to the rising sea levels.
Where is the Doomsday Glacier?
It’s part of the West Antarctic Ice Sheet, due south of the western United States – about 7,000 miles (over 11,000 kilometres) from the US’ shores.
Why is it called Thwaites Glacier?
Thwaites Glacier is named after Fredrik T Thwaites, a glacial geologist. However, Thwaites never actually visited the glacier – he was simply a prominent expert in glacial geology.
What would happen if Thwaites Glacier collapsed?
Research has indicated that if Thwaites Glacier were to collapse entirely, global sea levels would increase by 65cm. But it’s already losing ice, contributing to around 4% of all global sea-level rise, with the possibility to contribute more.
Can we do anything to avoid its collapse?
While it’s unlikely that the total meltdown of Thwaites Glacier can be entirely prevented, geoengineering projects are being researched in an attempt to slow Antarctic ice melt.
Is it melting already?
Thwaites Glacier is already losing about 50 billion tonnes of ice more than it is receiving in snowfall, which means it’s contributing to the rising sea levels around the globe. Ice loss from Thwaites and its nearby glaciers has doubled over the last 30 years.
In February 2026, scientists drilled to the bottom of the Thwaites Glacier to learn more about why it’s been melting so rapidly.
How long have we known about Thwaites Glacier?
Thwaites Glacier was first identified in 1947, when the US Navy undertook airborne photographic surveys. The glacier was mapped more thoroughly at the end of the 1950s and into the 1960s.
Top image: Thwaites Glacier. Credit: BBC News/Getty Images
