Bizarre blue streaks dotted across an ice shelf in Antarctica have been spotted by NASA.
These images, snapped by the OLI (Operational Land Imager) on January 1, show pools of pale blue meltwater peppered across the Amery Ice Shelf in East Antarctica.
This melting comes despite Antarctica only being halfway through its melting season—which runs between November 1 and March 31.
"The Amery is unique among Antarctic ice shelves given its long interior extent—greater than 500 kilometers (300 miles)—and extensive bordering bedrock exposures," Christopher Shuman, a glaciologist at the University of Maryland, Baltimore County, said in a statement.
"Yet, even in the deep chill of East Antarctica, the change of seasons causes surface melting far inland from the coastal ice front."
The Amery Ice Shelf is one of Antarctica's largest ice shelves, measuring about 23,200 square miles in area. It is fed primarily by the Lambert Glacier, one of the world's largest and longest glaciers, as well as other smaller glaciers like the Mellor and Fisher glaciers.
As the world warms due to climate change, Antarctica's ice has been increasingly declining. One 2018 study in the journal Nature found that Antarctica lost around 3 trillion metric tons of ice between 1992 and 2017, increasing in rate from 76 billion metric tons per year before 2012 to 219 billion metric tons per year in recent years.
The global numbers are out and 2024 was the world's warmest year since records began in 1850.
Global surface temperature was 2.32°F (1.29°C) above the 20th-century average. The 10 warmest years since 1850 have all occurred in the past decade. pic.twitter.com/RGBSVtjLMa
Last year, when Antarctica reached its lowest annual ice extent on February 20, 2024, it had 30 percent less ice than the 1981–2010 end-of-summer average. When it hit its annual maximum extent on September 19, it had the second lowest maximum in the satellite record—with the record low being set in 2023.
"The 2024 Antarctic maximum was 77,000 square miles above the 2023 record-low extent, but it was 598,000 square miles below the average maximum extent from 1981-2010," NOAA said.
Ice shelves like Amery act as buttresses, slowing the flow of glaciers into the sea, and playing a crucial role in stabilizing the Antarctic Ice Sheet.
The pale blue meltwater pools seen on the Amery are a common sight during Antarctica's melt season, caused by the warmer temperatures of the Southern Hemisphere's summer. The blue color of the pools can also exacerbate further melting, as the darker shades absorb more heat than the surrounding white ice.
If meltwater from these "blue puddles" drains through tiny cracks in the ice, it can weaken and destabilize the ice shelf, making it more vulnerable to breaking apart.
The pictured meltwater pools formed after an intense melt event in December last year, which broke the all-time record for melt extent.
Widespread coastal melting occurred in Antarctica through the second half of December and is continuing in the first few days of the new year in several areas. Read more in our latest Ice Sheets Today analysis. https://t.co/rZF1MPq9wf pic.twitter.com/srEUOXR9WQ
— National Snow and Ice Data Center (@NSIDC) January 9, 2025According to Bert Wouters, a researcher at TU Delft in the Netherlands, more of these meltwater pools had been observed popping up across the Amery in previous seasons compared to 2025.
"But on the other hand, it's still relatively early, so it's likely that we'll see more ponding in the coming weeks," he said.
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Reference
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