The study warns that Antarctica’s Pine Island Ice Shelf is more vulnerable than previously thought—and could lead to a 1.6-foot rise in global sea levels.
- The Pine Island Ice Shelf raises sea level to 1.6 ft. holds enough snow to raise
- It may be more sensitive to complete dissolution than previously
- In warmer climates, buoyancy events are more likely to occur.
- Experts hope the study will signal an urgent need to further reduce carbon emissions and mitigate the worst effects of climate change
Antarctica’s Pine Island Glacier is roughly the same size as England, one of the largest and fastest-changing glaciers in the world.
The glacier is responsible for about 25 percent of ice loss from Antarctica – equivalent to the amount of water in 13,000 Olympic swimming pools.
But a new study warns that the Pine Island Ice Shelf – the ice shelf that controls ice flow from the Pine Island Glacier – may be more vulnerable to complete dissolution than previously thought.
Worryingly, experts from the British Antarctic Survey (BAS) say its collapse could raise global sea levels by up to 1.6 feet (0.5 metres).
A new study warns that the Pine Island Ice Shelf – the ice shelf that controls ice flow from Pine Island Glacier – may be more vulnerable to complete dissolution than previously thought.
Pine Island Glacier
The Pine Island Ice Shelf controls the flow of ice from the Pine Island Glacier – roughly the size of England – into the Amundsen Sea.
This is an important role as the glacier is one of the largest and fastest changing glaciers in the world.
It is also responsible for about 25 percent 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 major processes.
First, the ice shelf is experiencing increased thinning as a result of an increase in the amount of ocean ice melting.
Meanwhile, in recent years there has also been an increase in calving events, during which ice mass breaks up into icebergs.
Now, in a new study, BAS researchers have shown that the combination of calving and melting is likely to make it disintegrate faster than previously thought.
“This study highlights the extreme sensitivity of ice shelves to climate change,” said Dr. Alex Bradley, an ocean modeler at BAS and lead author of the study.
‘This demonstrates that the interplay between calving and melting may promote the dissolution of the Pine Island Ice Shelf, which we already thought was vulnerable to collapse.’
To reach this conclusion, the team used advanced ocean modeling techniques to simulate the effects of sustained calming events.
Graphic shows how the ice front of Pine Island Glacier has retreated from 2009 to 2020
Previous studies have shown that the Pine Island Ice Shelf is becoming fragile due to two major processes
Their simulations showed that calving events could result in further thinning of the ice shelf, which in turn would make the ice shelf more vulnerable to calving.
This suggests that a feedback loop may exist between the two processes and may have triggered the ice shelf’s total collapse.
This would reduce the ability of the ice shelf to block the flow of sea ice from Pine Island Glacier and increase its contribution to global sea-level rise.
Bradley explained, ‘The complete disintegration of the Pine Island Ice Shelf would have profound consequences not only for Pine Island Glacier but for the whole of West Antarctica as it is believed to play an integral role in maintaining the stability of the West Antarctic Ice Sheet.
In a warmer climate, calving events are likely to be more frequent, experts have warned.
He hopes the new study will signal an urgent need to reduce carbon emissions and mitigate the worst effects of climate change.
Not only is the Pine Island glacier in danger of collapsing – earlier this month, a study warned that Antarctica’s Thwaites Glacier is also ‘grabbing with its nails’.
BAS researchers found that the glacier – widely known as the Doomsday Glacier – has retreated twice as fast over the past 200 years as previously thought.
For the first time, scientists mapped in high-resolution a significant area of the ocean floor in front of Thwaites that gives them a window into how fast the glacier has retreated and moved past.
The stunning imagery shows geological features that are new to science, and also provides a crystal ball of sorts for looking into Thwaites’ future.
Worryingly, analysis of the new images indicates that the rate of retreat of Thwaites that scientists have recently documented is lower than the fastest rates of change in its past.
Melting of glaciers and ice sheets will have a ‘dramatic effect’ on global sea levels
Global sea levels could rise by as much as 10 feet (3 meters) if the Thwaites Glacier in West Antarctica collapses.
Sea level rise threatens entire countries from Shanghai to London, low-lying areas of Florida or Bangladesh, and the Maldives.
For example, in the UK, a rise of 6.7 feet (2 m) or more can put areas such as Hull, Peterborough, Portsmouth and parts of east London and the Thames Estuary at risk of being submerged.
Large cities such as New York and Sydney could also be submerged by a glacier collapse that could begin over decades.
Parts of New Orleans, Houston and Miami in the US South will also be particularly hard hit.
A 2014 study by the Consortium of Concerned Scientists looked at 52 indicators of sea level in communities across the US.
It found that tidal flooding would increase dramatically in many East and Gulf Coast locations, based on a conservative estimate of projected sea level rise based on current data.
The results showed that most of these communities will experience a significant increase in the number and severity of tidal flood events in the coming decades.
By 2030, more than half of the 52 communities studied are projected to experience an average of at least 24 tidal floods per year in exposed areas, assuming projections of moderate sea level rise. Twenty of these communities may see three times or more the incidence of tidal flooding.
The mid-Atlantic coast is expected to see some of the biggest increase in flood frequency. Places such as Annapolis, Maryland and Washington, D.C. can expect more than 150 tidal floods a year, and many places in New Jersey can see 80 tidal floods or more.
In the UK, by 2040 an increase of two meters (6.5 ft) will cause large parts of Kent to be almost completely submerged, according to the results of a paper published in November 2016 in the Proceedings of the National Academy of Science.
Portsmouth, as well as areas of the south coast such as Cambridge and Peterborough, will also be heavily affected.
Cities and towns around the Humber estuary, such as Hull, Scunthorpe and Grimsby, will also experience intense flooding.