Iceberg A-23A is turning bright blue as it melts

Satellite images from late December 2025 show iceberg A-23A has bright blue surface melt ponds; the iceberg's area has fallen from about 4,000 km² in 1986 to roughly 1,182 km² by January 2026.

Iceberg A-23A broke away from Antarctica's Filchner Ice Shelf in 1986 and was once about 4,000 square kilometres. By January 2026 its area is estimated at about 1,182 square kilometres after losing large chunks while moving through warmer waters between the South Atlantic and the Southern Ocean. NASA's Terra satellite captured images on December 26 and 27, 2025 that show bright blue areas on the iceberg's surface. Scientists describe those blue areas as large meltwater pools and say they are likely linked to ongoing disintegration. Key observations: - A-23A measured about 4,000 km² in 1986 and is estimated at about 1,182 km² as of January 2026. - Terra satellite images from December 26–27, 2025 show bright blue meltwater pools visible on the iceberg's surface. - Ted Scambos, a senior research scientist at the University of Colorado Boulder, suggested the blue spots are likely due to disintegration events where water in cracks forces them open. - A white area in the images may be water pooling that has punched through the ice, which was reported as evidence the iceberg has sprung a leak. Summary: The images indicate continued melting and possible structural weakening of A-23A, reflected in its reduced area and visible surface melt features. Undetermined at this time.