- If Thwaites Glacier collapses, it could raise global sea level by as much as 10 feet
- Preventing warm water from melting it underneath could help it freeze and grow
- John Moore wants to anchor a giant curtain on the sea floor to block warm water
John Moore is on a mission to slow down the melting of the world’s widest glacier, nicknamed the ‘doomsday glacier’ for the havoc it could unleash on the world.
The 74,000 square mile Thwaites Glacier, located on the western edge of Antarctica, is losing about 50 billion more tons of ice than it receives in new snowfall
Professor Moore told DailyMail.com that he and his colleagues want to stop the glacier’s retreat by placing a 62-mile-long curtain in front of it to block warm ocean water from melting the underside.
Its melting alone already contributes about four percent to the world’s sea level rise, and if it were to melt all the way, it would raise sea levels around the entire world by as much as 10 feet – which is how it earned its ominous nickname.
That amount of sea level rise would put coastal cities around the world at serious risk of major flooding.
Their plan: Anchor a giant curtain along 62 miles of seafloor to block most of the warm water from melting the glacier from underneath.
The estimated cost: $50 billion. Moore said he is optimistic that the 29 countries in the Antarctic Treaty will foot the bill.
Most of the ice Thwaites loses comes from underneath, where the warm, salty waters circulating deep down in the sea wear it away.
As the climate warms, these deep ocean currents get warmer, melting the glacier’s underside even faster.
With warmer ocean temperatures, the winter cycle of re-freezing does less and less each year to recover the melted ice.
Occasionally, the glacier will calve – the scientific term for when a large piece of a glacier’s face falls off.
But this is just the obvious, outward sign of the much more serious problem of underwater melting.
Before the industrial revolution, when humans began belching millions of tons of CO2 and other greenhouse gases into Earth’s atmosphere, Thwaites and other glaciers had normal cycles of thinning and thickening.
In the winter, the glacier would grow as the ice thickened, and in the summer it would shrink back as the ice thinned.
As the planet warms, though, there is way more thickening than thinning.
To some degree, this process would be happening regardless of global warming, said John Moore, research professor of climate change at the University of Lapland’s Arctic Centre in Finland.
At a certain point, though, the melting is simply too much.
‘Beyond the tipping point, glaciers like Thwaites just collapse regardless of the CO2 concentration because the buttressing they need to be stable goes away as the floating shelf thins, like kicking away a prop holding up a fence,’ he told DailyMail.com.
‘So if we want to replace the buttressing, we need to mimic nature and allow the shelf to thicken again and buttress itself,’ said Moore. ‘The way to reduce the melt is to block off some of the warm water reaching it.’
This is where the curtain comes in.
They plan to anchor a curtain at the bottom of the Amundsen Sea, blocking undersea currents from hitting the underside of Thwaites Glacier.
Held up by a buoyant top edge and anchored at the bottom, the curtain would float at the bottom of the ocean, invisible from the water’s surface.
Getting it into place without damaging the glacier won’t be a problem, said Moore.
‘We would put the curtain a long way from the glacier, just blocking the warm water in deep channels where they are narrow and accessible,’ he said.
The biggest challenges, said Moore, are less about avoiding further damage to the glacier and more about the safety of the people putting the curtain in place.
‘The harsh conditions, the short working season with enough daylight, and the danger from the many icebergs that are around’ are the biggest challenges, he said.
It will still be years before they install the curtain, but Moore and his colleagues at Cambridge University are working on computer simulations right now to get the design right, as well as ‘some small scale tank tests, basically with fish tanks.’
Next, they plan to install a prototype in the River Cam in Cambridge next summer.
‘We also plan on testing in the Norwegian fjord a set of 10 different designs to see how they perform under realistic currents and wear and tear,’ he said.
‘Then later if there are no serious problems, we would try it on a fjord with a glacier inflow in Svalbard.’
If all of that goes according to plan, Moore and his team would see whether the Greenlanders wanted to use them – as well as whether an agreement could be worked out to put the curtain in Antarctica to protect Thwaites Glacier, of course.
Dr. Thomas Hughes is a UK-based scientist and science communicator who makes complex topics accessible to readers. His articles explore breakthroughs in various scientific disciplines, from space exploration to cutting-edge research.
