Antarctica’s Pine Island Ice Shelf is more vulnerable than previously thought – and could cause global sea levels to rise by 1.6 FEET if it collapses, study warns
- The Pine Island Ice Shelf holds back enough ice to raise sea levels by 1.6ft
- It could be more vulnerable to complete disintegration than previously thought
- In a warming climate, calving events are likely to become more frequent
- Experts hope the study will further signal the urgent need to reduce carbon emissions and mitigate the worst effects of climate change
Measuring roughly the same size as England, Antarctica’s Pine Island Glacier is one of the world’s largest and fastest-changing glaciers.
The glacier is responsible for approximately 25 per cent of ice loss from Antarctica – equivalent to the amount of water in 13,000 Olympic swimming pools.
But a new study has warned that the Pine Island Ice Shelf – the ice shelf that controls the flow of ice from the Pine Island Glacier – could be more vulnerable to complete disintegration than previously thought.
Worryingly, experts from the British Antarctic Survey (BAS) say that its collapse could cause global sea levels to rise by a whopping 1.6 feet (0.5 metres).
A new study has warned that the Pine Island Ice Shelf – the ice shelf that controls the flow of ice from the Pine Island Glacier – could be more vulnerable to complete disintegration than previously thought
Pine Island Glacier
The Pine Island Ice Shelf controls the flow of ice from Pine Island Glacier – roughly the size of England – into the Amundsen Sea.
This is a crucial role as the glacier is one of the world’s largest and fastest changing.
It is also responsible for approximately 25 per cent of ice loss from Antarctica.
This is equivalent to the amount of water in 13,000 Olympic swimming pools.
Previous studies have shown that the Pine Island Ice Shelf is becoming increasingly fragile due to two key processes.
Firstly, the ice shelf is experiencing enhanced thinning as a result of an increase in the amount of ice melting into the sea.
Meanwhile, calving events have also increased in recent years, during which masses of ice break off into icebergs.
Now, in a new study, researchers from BAS have shown that the combination of calving and melting will likely cause it to disintegrate faster than previously thought.
‘This study highlights the extreme sensitivity of ice shelves to climate change,’ said Dr Alex Bradley, an ocean modeller at BAS and lead author on the study.
‘It shows the interplay between calving and melting can promote disintegration of the Pine Island Ice Shelf, which we already thought was vulnerable to collapse.’
To reach this conclusion, the team used advanced ocean modelling techniques to simulate the effects of continued calving events.
Graphic shows how the ice front of the Pine Island Glacier ice front has retreated from 2009 to 2020
Previous studies have shown that the Pine Island Ice Shelf is becoming increasing fragile due to two key processes
Their simulations showed that calving events could result in further thinning of the ice shelf, which will in turn make the ice shelf more vulnerable to calving.
This suggests that a feedback loop between the two processes could exist and speed up the total collapse of the ice shelf.
This would reduce the ice shelf’s ability to stem the flow of ice from Pine Island Glacier into the sea and increase its contribution to global sea-level rise.
‘Complete disintegration of the Pine Island Ice Shelf will have profound consequences not only for Pine Island Glacier but all of West Antarctica as it is thought to play an integral role in maintaining the stability of the West Antarctic Ice Sheet,’ Dr Bradley explained.
In a warming climate, calving events are likely to become more frequent, the experts warn.
They hope the new study will further signal the urgent need to reduce carbon emissions and mitigate the worst effects of climate change.
The Pine Island Glacier isn’t the only one at risk of collapsing – earlier this month, a study warned that Antarctica’s Thwaites Glacier is also ‘holding on by its fingernails’.
BAS researchers discovered that the glacier – which is widely known as the Doomsday Glacier – has retreated twice as fast as previously thought over the past 200 years.
For the first time, scientists mapped in high-resolution a critical area of the seafloor in front of Thwaites that gives them a window into how fast the glacier has retreated and moved in the past.
The stunning imagery shows geological features that are new to science, and also provides a kind of crystal ball to see into Thwaites’ future.
Alarmingly, analysis of the new images indicates that the rate of Thwaites’ retreat that scientists have documented more recently is small compared to the fastest rates of change in its past.
GLACIERS AND ICE SHEETS MELTING WOULD HAVE A ‘DRAMATIC IMPACT’ ON GLOBAL SEA LEVELS
Global sea levels could rise as much as 10ft (3 metres) if the Thwaites Glacier in West Antarctica collapses.
Sea level rises threaten cities from Shanghai to London, to low-lying swathes of Florida or Bangladesh, and to entire nations such as the Maldives.
In the UK, for instance, a rise of 6.7ft (2 metres) or more may cause areas such as Hull, Peterborough, Portsmouth and parts of east London and the Thames Estuary at risk of becoming submerged.
The collapse of the glacier, which could begin with decades, could also submerge major cities such as New York and Sydney.
Parts of New Orleans, Houston and Miami in the south on the US would also be particularly hard hit.
A 2014 study looked by the union of concerned scientists looked at 52 sea level indicators in communities across the US.
It found tidal flooding will dramatically increase in many East and Gulf Coast locations, based on a conservative estimate of predicted sea level increases based on current data.
The results showed that most of these communities will experience a steep increase in the number and severity of tidal flooding events over the coming decades.
By 2030, more than half of the 52 communities studied are projected to experience, on average, at least 24 tidal floods per year in exposed areas, assuming moderate sea level rise projections. Twenty of these communities could see a tripling or more in tidal flooding events.
The mid-Atlantic coast is expected to see some of the greatest increases in flood frequency. Places such as Annapolis, Maryland and Washington, DC can expect more than 150 tidal floods a year, and several locations in New Jersey could see 80 tidal floods or more.
In the UK, a two metre (6.5 ft) rise by 2040 would see large parts of Kent almost completely submerged, according to the results of a paper published in Proceedings of the National Academy of Science in November 2016.
Areas on the south coast like Portsmouth, as well as Cambridge and Peterborough would also be heavily affected.
Cities and towns around the Humber estuary, such as Hull, Scunthorpe and Grimsby would also experience intense flooding.