Antarctic winter sea ice hits 'extreme' record low
September 26, 2023
Since recording began in 1979, the surface area of sea ice around Antarctica when it should be at its maximum size was at the lowest level "by a wide magin," according to US data.
The ice that packs the ocean around Antarctica reaches its largest size during the colder winter monthsImage: Sebnem Coskun/AA/picture alliance
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The sea ice around Antarctica has likely hit new record low levels this winter, the United States National Snow and Ice Data Center (NSIDC) said on Monday.
The winter sea ice around the southernmost continent had a record low surface area when it was at its maximum size, fuelling scientists' worries that the impact of climate change at the pole is building up.
Antarctic sea ice had only reached a maximum size of 16.96 million square kilometers (6.55 million square miles) this year, as recorded on September 10, NSIDC said, as the southern hemisphere goes into spring.
The ice that packs the ocean around Antarctica reaches its largest size during the colder winter months, so the September 10 record will likely remain the maximum for this year.
"This is the lowest sea ice maximum in the 1979 to 2023 sea ice record by a wide margin," NSIDC said.
The center said that the figures were preliminary and a full analysis will be released next month.
"It's not just a record-breaking year, it's an extreme record-breaking year," Walt Meier, a senior scientist at NSIDC, said.
Global warming concerns
For decades, the Antarctic sea ice pack had been stable, even expanding slightly.
But "since August 2016, the Antarctic sea ice extent trend took a sharp downturn across nearly all months," the center said.
Researchers have cautioned that the shift can have grave repercussions for animals like penguins who breed and rear their young on the sea ice.
They warn it could also hasten global warming by reducing how much sunlight is reflected by white ice back into space.
The cause behind this shift has been a point of debate among scientists. Some are hesitant about establishing a formal link with global warming.
The downward trend is "now thought to be linked to warming in the uppermost ocean layer," the NSIDC said.
"There is some concern that this may be the beginning of a long-term trend of decline for Antarctic sea ice, since oceans are warming globally."
Antarctica: Mighty Thwaites Glacier threatens to melt
Global warming is threatening ice shelves linked to the Thwaites Glacier. If they fracture and break, much of the glacier could melt into the sea, causing a dramatic sea level rise.
Image: NASA/Zumapress/picture alliance
Thawing giant
Thwaites Glacier is one of the largest of its kind in Antarctica. Covering an area of 192,000 square kilometers, it is roughly the size of the UK. One third of the glacier consists of large floating ice platforms, or ice shelves. Increasingly, however, these platforms have been fracturing.
Image: NASA/Zumapress/picture alliance
Ice shelf could shatter like a windshield
Researchers warn that the mighty glacier could be undergoing dramatic change. It is possible that, within the next three to five years, a 45-kilometer-long ice shelf segment could shatter and break like a car window, researchers from the International Thwaites Glacier Collaboration project say.
Image: NASA/AFP
Serious rise in sea level looms
The ice shelf currently prevents the gargantuan glacier from slipping into the sea. If it were to shatter, huge amounts of glacial ice could end up melting into the water. Much of the glacier would break up into floating icebergs, say scientists.
Image: M. DeFreitas /blickwinkel/imago images
No isolated event
It would not be the first incident of this kind. In July 2017, the vast A68 iceberg detached from the Larsen C ice shelf in West Antarctica. While icebergs break off constantly, the timing of the event — during the cold Antarctic winter months — baffled scientists. Many suspect global warming could be a factor.
Over the past 20 years, seven ice shelves along the Antarctic Peninsula have shattered, or drastically receded. This means more ice has melted into the sea, which has caused sea levels to rise.
Image: Michael S. Nolan/imago images
Warm water accelerates thaw
Climate change, or the warming of the sea more specifically, is to blame for the Thwaites Glacier melting. Warm water flowing beneath the ice shelves have caused large sections to thaw, forming glacier caves. This melting process has accelerated tremendously over the past 30 years. Scientists are closely monitoring the development.
Image: Michael S. Nolan/imago images
Breakup could trigger major sea level rise
Together, the melting Thwaites Glacier and Pine Island Glacier already account for a 10% rise in global sea levels. If the Thwaites Glacier were to break up entirely, releasing all its ice into the water, sea levels worldwide would rise by about 65 centimeters (25 inches).
Image: John Sonntag/Zumapress/picture alliance
'Doomsday Glacier'
The breakup of the Thwaites Glacier would trigger a dangerous chain reaction. Should it melt, other nearby glaciers (like the Pine Island Glacier, pictured) could follow. Vast swaths of the West Antarctica ice could break off, causing sea levels to rise by up to 3,3 meters. That’s why the Thwaites Glacier has been nicknamed the Doomsday Glacier.
