Dying iceberg turns bright blue
"It's hard to believe it won't be with us much longer."
In 1986, iceberg A-23A broke away from Antarctica’s Filchner Ice Shelf. Back then, it measured about 4,000 square kilometres — larger than Edmonton, Calgary, Winnipeg, Toronto, Montreal, and St. John’s combined.
But it has shrunken significantly over the years, with January 2026 estimates calculating the iceberg’s area now sits at 1,182 square kilometres after losing large chunks when it moved through warmer waters between the South Atlantic and Southern Ocean.
Now, images captured by NASA’s Terra satellite on December 26 and 27 2025 show the iceberg has turned bright blue due to large meltwater pools that are visible from its surface.
Speaking with NASA, Ted Scambos, a senior research scientist at the University of Colorado Boulder, suggests that the blue spots are likely due to disintegration events.
"You have the weight of the water sitting inside cracks in the ice and forcing them open," he explains.
Iceberg A-23A on December 26, 2025 (NASA/MODIS)
Iceberg could soon be gone
A white area to the left could be the result of water pooling, creating enough pressure to punch through it, and providing evidence that the iceberg has sprung a leak.
Experts say the imagery indicates the iceberg could be “days or weeks” from melting away completely.
"I certainly don't expect A-23A to last through the austral summer," Shurman told NASA.
A-23A is drifting toward an iceberg “graveyard” near South Georgia Island—where it will melt back into the ocean -- but, as of the time of this writing, it remains impressively large.
“Though much smaller than it once was, what remains is still among the largest icebergs in the ocean, covering an area larger than New York City,” NASA says in a statement.
Centuries-old lines
Another feature seen on the new images: Linear blue and white patterns, called striations, that likely formed when the ice was part of a glacier that dragged across Antarctic bedrock.
"The striations formed parallel to the direction of flow, which ultimately created subtle ridges and valleys on the top of the iceberg that now direct the flow of meltwater," Walt Meier, a senior research scientist at the National Snow & Ice Data Center, says in a statement.
"It's impressive that these striations still show up after so much time has passed, massive amounts of snow have fallen, and a great deal of melting has occurred from below," retired University of Maryland, Baltimore County scientist Chris Shuman added.
Iceberg A-23A on December 27, 2025 (NASA/MODIS)
A long journey
After detaching some 40 years ago, A-23A spent 30 years grounded in the Weddell Sea, breaking free in 2020 to spend several months spinning in an ocean vortex. It eventually broke away and made its way into the open ocean in 2025, where it has been disintegrating.
"I'm incredibly grateful that we've had the satellite resources in place that have allowed us to track it and document its evolution so closely," Shuman said.
"A-23A faces the same fate as other Antarctic bergs, but its path has been remarkably long and eventful. It's hard to believe it won't be with us much longer."