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April 12, 2025 - Iceberg A23a Remains Grounded
April 11, 2025
March 17, 2024
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In late February 2025, the slow drift of massive Iceberg A23a ground to a halt just off the coast of South Georgia Island. Satellite imagery, which had followed the course of the largest iceberg on Earth on its long and winding journey since it calved off Antarctica’s Filchner-Ronne Ice Shelf in 1986, showed that forward motion appeared to have stopped on February 25. The big berg appears to have become firmly grounded on the shelf that surrounds the remote island, remaining stuck well into April.
On April 11, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite acquired this true-color image of A23a surrounded by cloud and parked firmly off South Georgia Island. This is pared with a second Terra MODIS image acquired on March 17.
Clicking on the dates under the images shows that the mega-iceberg appears essentially frozen in the same location, with no forward motion. It also hasn’t turned, despite the influence of currents or winds, suggesting that it is truly firmly grounded in place. A23a also seems to remain nearly the same size, but small signs of wear can be seen on the northwestern edge, which has shed some ice. Several small icebergs can be seen floating near A23a, presumably slivers that have calved off the large iceberg in recent days.
Image Facts
Satellite:
Terra
Date Acquired: 4/11/2025
Resolutions:
1km (74.4 KB), 500m (197 KB), 250m (357.9 KB)
Bands Used: 1,4,3
Image Credit:
MODIS Land Rapid Response Team, NASA GSFC
April 11, 2025 March 17, 2024
In late February 2025, the slow drift of massive Iceberg A23a ground to a halt just off the coast of South Georgia Island. Satellite imagery, which had followed the course of the largest iceberg on Earth on its long and winding journey since it calved off Antarctica’s Filchner-Ronne Ice Shelf in 1986, showed that forward motion appeared to have stopped on February 25. The big berg appears to have become firmly grounded on the shelf that surrounds the remote island, remaining stuck well into April.
On April 11, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite acquired this true-color image of A23a surrounded by cloud and parked firmly off South Georgia Island. This is pared with a second Terra MODIS image acquired on March 17.
Clicking on the dates under the images shows that the mega-iceberg appears essentially frozen in the same location, with no forward motion. It also hasn’t turned, despite the influence of currents or winds, suggesting that it is truly firmly grounded in place. A23a also seems to remain nearly the same size, but small signs of wear can be seen on the northwestern edge, which has shed some ice. Several small icebergs can be seen floating near A23a, presumably slivers that have calved off the large iceberg in recent days.
Image Facts
Satellite:
Terra
Date Acquired: 4/11/2025
Resolutions:
1km (74.4 KB), 500m (197 KB), 250m (357.9 KB)
Bands Used: 1,4,3
Image Credit:
MODIS Land Rapid Response Team, NASA GSFC
