The year when iceberg A-23A first broke off from Antarctica. Filchner Ice ShelfRonald Reagan was President of the United States, and the film Top shooter set box office records. Forty years later, the massive tabular iceberg—one of the largest and longest-lived icebergs ever discovered by scientists—is soaked in blue meltwater and on the verge of complete disintegration, drifting in the South Atlantic between the eastern tip of South America and the island of South Georgia.
When it first broke away from Antarctica in 1986, the iceberg was almost twice the size of Rhode Island – about 4,000 square kilometers. Ratings According to the US National Ice Center, the iceberg had an area of 1,182 square kilometers (456 sq mi) in early January 2026 after breaking up several large pieces in July, AugustAnd September 2025 as it transitioned into relatively warm summer conditions by December.
When MODIS (Moderate Resolution Imaging Spectroradiometer) on NASA satellite Terra The satellite captured this image of what remained of the submerged berg on December 26, 2025, showing vast pools of blue meltwater on its surface. Although it is much smaller than it once was, it is still one of the largest icebergs in the ocean, covering an area larger than New York City. A day later, an astronaut aboard the International Space Station took a photo showing a closer view (below) of the iceberg with an even more extensive melt pool.
The “blue mess” areas are likely the result of ongoing disintegration processes, explained Ted Scambos, a senior research scientist at the University of Colorado Boulder. “The weight of the water sits inside the cracks in the ice and causes them to open,” he said. Note also the thin white line around the outer edge of the iceberg, which appears to be encased in blue meltwater.shaft-ditch“a pattern caused by the upward bending of an iceberg plate as its edges melt at the waterline.
The striking linear patterns of blue and white on the iceberg are likely due to stripes that were cleared hundreds of years ago when the ice was part of a glacier that ran along Antarctic bedrock.
“The stripes formed parallel to the direction of the flow, ultimately leading to the formation of thin ridges and depressions at the top of the iceberg that now direct the flow of meltwater,” explained Walt Meyer, senior scientist at the National Snow and Ice Data Center. “It's impressive that these bands are still showing up after so much time has passed, so much snow has fallen, and so much melting has occurred from below,” added former University of Maryland, Baltimore County scientist Chris Shuman.
The MODIS image suggests that the diseased iceberg also leaked. The white area to the left of it may be the result of what Schumann called a “blowout.” The weight of water accumulated on top of a towering iceberg would create enough pressure at the edges to break through. The release could have caused meltwater to spill tens of meters onto the ocean surface, forming what researchers call a “freshwater plume,” where it mixed with melange pieces of ice floating next to an iceberg.
Scientists say these signs indicate the iceberg may be just days or weeks away from completely disintegrating. “I certainly don’t expect A-23A to last through the southern summer,” Schumann said, noting that at this time of year skies typically become clear and air and water temperatures rise—factors that speed up the process of disintegration in an area known among ice experts as a “graveyard” for icebergs. It's already in water that's about 3 degrees Celsius, and the currents are pushing it toward even warmer waters, which are quickly eating away at it, Meyer added.
Even by Antarctic standards, A-23A has had a long and winding journey, filled with unexpected chapters that have improved scientists' understanding of the “megabergs” that are periodically washed up in the Southern Ocean. After more than 30 years moored in the shallow waters of the Weddell Sea, the A-23A broke free in 2020 and then spent several months in rotating ocean vortex called a Taylor column. In the end it's flew away and headed north almost colliding with South Georgia Island and overnight stay in shallow water for several months before escaping to the open ocean where he was quickly falls apart throughout 2025.
Scientists who have tracked the iceberg throughout their careers view its inevitable demise as a bittersweet moment. “I’m incredibly grateful that we have the satellite resources that have allowed us to track it so closely and document its evolution,” Schumann said. “A-23A faces the same fate as other Antarctic icebergs, but its journey was surprisingly long and eventful. It's hard to believe he won't be with us anymore.”
Even as A-23A disappears, other massive icebergs remain or drift along the Antarctic coastline. Some of them, including A-81, B22A and D15A, each have an area of more than 1,500 square kilometers and are waiting to break free and begin their journey north.
NASA Earth Observatory image by Michala Garrison using NASA MODIS data. EOSDIS LANCE And GIBS/Worldview. Photo of an ISS astronaut ISS074-E-8943 was purchased on December 27, 2025 with a Nikon Z 9 digital camera with a focal length of 500 millimeters. It is provided by the ISS Crew Earth Observation Center and the Earth Sciences and Remote Sensing Division of NASA's Johnson Space Center. The image was taken by a member Expedition 74 crew. The image was cropped and enhanced to improve contrast, and lens artifacts were removed. International Space Station program supports the laboratory within ISS National Laboratory help astronauts take photographs of Earth that will be of greatest value to scientists and the public, and make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed on the NASA/JSC website. Gateway to photographs of Earth taken by astronauts. Story by Adam Voyland.
- AP News (September 4, 2025) The strongest and largest iceberg is breaking apart, and new cracks are appearing in its death spiral.. As of January 7, 2026
- British Antarctic Survey (4 March 2025) The world's largest icebergs near the subantarctic island of South Georgia. As of January 7, 2026
- NASA Earth Observatory (September 24, 2025) The last drift of a giant iceberg. As of January 7, 2026
- NASA Earth Observatory (August 1, 2025) Shrinking size of Antarctic iceberg. As of January 7, 2026
- NASA Earth Observatory (May 6, 2025) Antarctic iceberg loses its edge. As of January 7, 2026
- NASA Earth Observatory (February 6, 2015) Upside down, dirty, amazing icebergs. As of January 7, 2026
- NPR (September 5, 2025) The world's oldest and largest iceberg will soon disappear. As of January 7, 2026
- Scambos, T., etc. (2025) How to tame your iceberg: Iceberg A23a drift track in 2024. Bulletin of the American Meteorological Society, 106(8), S357–S400.
- Scambos, T., etc. (2005) ICESat profiles of tabulated iceberg boundaries and iceberg decay at low latitudes. Geophysical Research Letters, 32(23).
- USA today (2025, September 4) The world's largest iceberg, A23a, breaks. Look at satellite and aerial images.. As of January 7, 2026
- US National Ice Center (January 7, 2026) Antarctic iceberg data. As of January 7, 2026
