Antarctica’s ‘Doomsday Glacier’ shedding ice at fastest rate in 5,000 years

‘Runaway ice loss’ could raise sea levels by over three metres in coming centuries

Harry Cockburn
Environment Correspondent
Thursday 16 June 2022 16:02
Comments
<p>The floating ice shelf currently preventing the rapid disintegration of the Thwaites glacier</p>

The floating ice shelf currently preventing the rapid disintegration of the Thwaites glacier

Leer en Español

Two Antarctic glaciers are now losing ice at a faster rate than any time over the past 5,500 years, with "potentially disastrous" implications for sea level rise, new research has found.

The Thwaites Glacier, known as the "Doomsday glacier", due to the grave risk its melting poses to the world, is around the size of Great Britain, and its neighbour, the Pine Island Glacier is only slightly smaller.

The two glaciers form part of the Western Antarctic Ice Sheet, which is being impacted by warming temperatures due to the climate crisis, and are already contributing to global sea level rise.

These glaciers are especially susceptible to rapid melting because they sit on an inland-sloping bed where relatively warm ocean water is able to flow underneath floating, sea-facing parts of the glacier tongues and erode the ice sheet from beneath.

This process can lead to runaway ice loss, the research team from the British Antarctic Survey, Imperial College London and the University of Maine said.

The rapid retreat of these two glaciers could reduce the size of the West Antarctic Ice Sheet, potentially contributing as much as 3.4 metres (11 feet) to global sea level rise over the next several centuries.

Over the last 40 years Thwaites is estimated to have lost around 595 billion tons of ice, contributing to a 4 per cent rise in the world’s sea levels.

The research team used radiocarbon dating of shells from ancient beaches that are now elevated above modern sea level to reconstruct changes in relative sea level over time. This showed exactly where the glaciers were at different points in time.

The results indicated relatively stable glacier behaviour over the past 5,500 years, with no evidence of large-scale glacier retreat or advance.

But that has changed in recent decades.

“Our work suggests that these vulnerable glaciers were relatively stable during the past millennia, yet their current rate of melting is accelerating and raising global sea level,” said co-author Dylan Rood, senior lecturer at Imperial College London.

“These currently elevated rates of ice melting may signal that those vital arteries from the heart of West Antarctic Ice Sheet have burst, leading to accelerating flow into the ocean that is potentially disastrous for future global sea level in a warming world.”

The research also suggested that the glaciers may have been much smaller than they are now in the geologically-recent past – namely, during the mid-Holocene period, an era over 5,000 years ago that was even warmer than the present day.

If the glaciers were smaller at this point, they must have subsequently re-grown, raising the hope that they could do this again in the future.

In December last year scientists suggested the ice shelf holding back the glacier was fracturing and may only last five years, leading to a faster flow of ice into the Southern Ocean.

The research is published in the journal Nature Geoscience.

Register for free to continue reading

Registration is a free and easy way to support our truly independent journalism

By registering, you will also enjoy limited access to Premium articles, exclusive newsletters, commenting, and virtual events with our leading journalists

Please enter a valid email
Please enter a valid email
Must be at least 6 characters, include an upper and lower case character and a number
Must be at least 6 characters, include an upper and lower case character and a number
Must be at least 6 characters, include an upper and lower case character and a number
Please enter your first name
Special characters aren’t allowed
Please enter a name between 1 and 40 characters
Please enter your last name
Special characters aren’t allowed
Please enter a name between 1 and 40 characters
You must be over 18 years old to register
You must be over 18 years old to register
Opt-out-policy
You can opt-out at any time by signing in to your account to manage your preferences. Each email has a link to unsubscribe.

By clicking ‘Create my account’ you confirm that your data has been entered correctly and you have read and agree to our Terms of use, Cookie policy and Privacy notice.

This site is protected by reCAPTCHA and the Google Privacy policy and Terms of service apply.

Already have an account? sign in

By clicking ‘Register’ you confirm that your data has been entered correctly and you have read and agree to our Terms of use, Cookie policy and Privacy notice.

This site is protected by reCAPTCHA and the Google Privacy policy and Terms of service apply.

Register for free to continue reading

Registration is a free and easy way to support our truly independent journalism

By registering, you will also enjoy limited access to Premium articles, exclusive newsletters, commenting, and virtual events with our leading journalists

Already have an account? sign in

By clicking ‘Register’ you confirm that your data has been entered correctly and you have read and agree to our Terms of use, Cookie policy and Privacy notice.

This site is protected by reCAPTCHA and the Google Privacy policy and Terms of service apply.

Join our new commenting forum

Join thought-provoking conversations, follow other Independent readers and see their replies

Comments

Thank you for registering

Please refresh the page or navigate to another page on the site to be automatically logged inPlease refresh your browser to be logged in