The world’s largest glacier is melting much faster and could add twice as much to global sea levels as previously expected over the next century.
uncertain
glacier → melt → century
New research published this week by a team of glaciologists has found that the Thwaites glacier in West Antarctica is losing mass rapidly because warm seawater is pushing underneath it and melting its core.
asserted
seawater → publish → core
This could add 1.2 inches (30mm) to water levels even if global warming does not accelerate as predicted.
uncertain
warming → add → levels
Recommended Stories
list of 4 items- list 1 of 4The Nepal floods question: When the Himalayas collapse, who gets warned?
asserted
who → collapse → items-
- list 2 of 4India to supply Nepal electricity after floods wrecked hydropower projects
- list 3 of 4El Nino reaches super status: Where will it bring rain, drought and heat?
- list 4 of 4‘The drought has left its mark’: Slovenia’s potato lovers lament low yields
The findings, published in the journal Nature Communications, add to a growing body of evidence that shows that the glacier, which has been receding for decades, is now losing mass even faster than scientists thought.
asserted
scientists → supply → mass
Researchers at the University of California in the United States collaborated with NASA’s Jet Propulsion Laboratory for the study.
asserted
Researchers → collaborate → study
Here’s what we know about the findings:
asserted
we → ’ → findings
Nicknamed the “Doomsday Glacier”, Thwaites is the largest glacier on Earth, spanning an area of around 192,000sq km (74,130sq miles) or roughly the size of Senegal – and larger than the US state of Florida.
asserted
Thwaites → nickname → Florida
It is located on the Walgreen Coast of Marie Byrd Land in remote western Antarctica and forms part of the great West Antarctic ice sheet, which includes other glaciers and is 14 times the size of Thwaites.
asserted
which → locate → Thwaites
The glacier was first mapped in 1947 and is named after the late American glaciologist Fredrik T Thwaites, although he never visited it.
asserted
he → map → it
In the 1980s, scientists discovered that Thwaites is melting rapidly and have closely monitored its melting process as concerns have grown ever since.
asserted
concerns → discover → process
Because it is so big, the glacier’s collapse would sharply raise global sea levels by a catastrophic amount – although researchers don’t project that will happen for many decades, or even a few centuries.
asserted
that → raise → decades
Together, Thwaites and other glaciers such as the Pine Island glacier – an ice stream in West Antarctica which flows into Pine Island Bay in the Amundsen Sea – act as a barrier that holds back the vast and vulnerable West Antarctic ice sheet.
asserted
that → flow → sheet
If melted, the ice sheet could cause many coastal cities to be submerged around the world.
uncertain
cities → melt → world
At present, ice loss from Thwaites contributes around four percent of all global sea-level rise.
asserted
loss → contribute → rise
Studies have calculated that the glacier has lost more than 1,000 billion tonnes of ice since 2000, and continues to lose 50 billion tonnes of ice per year.
asserted
glacier → calculate → year
Why is the glacier melting?
asserted
glacier → melt → ?
The main drivers are warm ocean water which is actively melting the Thwaites glacier from underneath it, according to several studies.
uncertain
which → melt → studies
Ocean warming is caused by human-induced climate change, in particular from the burning of polluting fossil fuels.
asserted
warming → cause → fuels
In a 2019 study, the NASA Jet Propulsion Laboratory discovered a giant underwater cavity beneath the Thwaites glacier that spread across an area two-thirds the size of Manhattan, which researchers said was likely speeding up the glacier’s thinning.
asserted
researchers → discover → thinning
Rising temperatures have caused glaciers to lose about five percent of their ice since 2000, according to the European Space Agency.
uncertain
glaciers → rise → Agency
What has the latest research found?
asserted
research → find → What
Thwaites could add as much as 1.2 inches (30mm) – double the current estimates – to sea levels by 2100, even without any additional global warming, the study found.
uncertain
study → add → warming
The researchers said they used new computer models that paint a clearer picture of melting activity under the threatened glacier at its grounding line – the boundary where it transitions from resting entirely on bedrock to spreading out over the sea in the form of ice shelves.
asserted
it → say → shelves
Where other ice sheet models conclude a grounding line is fixed, the scientists said they developed the concept of a broader “grounding zone” instead.
asserted
they → conclude → zone
In this scenario, seawater lifts and lowers the ice in a “tidal pumping” process that allows warm water to reach “deep underneath the ice sheets and causing vigorous melting,” lead author Mattia Poinelli, a project scientist at UCLA, told media.
asserted
Poinelli → lift → media
That melting process is accelerating the Thwaites’ “unpinning” from the Mouginot Ridge – an important underwater bedrock currently stabilising the glacier from below.
asserted
process → melt → glacier
The study concluded that there is a 60 percent chance that Thwaites could unpin from the ridge by the end of the century.
uncertain
Thwaites → conclude → century
However, experts say more studies are needed to accurately predict the volume of Thwaites’ ice loss.
asserted
studies → say → loss
In separate findings, scientists from the British Antarctic Survey concluded that Thwaites will continue losing ice for at least the next 150 years, even under the most extreme ocean cooling conditions imaginable.
asserted
Thwaites → conclude → conditions
The study, which used computer simulation models that examined the melting effects of the ocean over the next century and a half, was published in Geophysical Research Letters in July.
asserted
that → use → July
The Aporia
