Iceberg on the Loose 

by | Dec 4, 2023

The full animated gif of the sequence can be viewed at the homepage. 

After being grounded on the ocean floor for well over four decades, the largest iceberg in the world is on the loose. 

The iceberg, known as A23a, calved from the Filchner-Ronne ice shelf in West Antarctica in 1986, but quickly ran aground. By 2020, it had lost its grip on seafloor and began drifting in the Weddell Sea. Scientists say it’s not unusual for icebergs to become grounded, but over time they shrink enough to unground and float. 

Now, however, driven by winds and currents, A23a has put a spurt on and is heading quickly away from Antarctic waters – as this animation of Copernicus Sentinel-1 images shows. The animation uses satellite images from Nov. 2, Nov. 14, and Nov. 26, 2023. 

Like most icebergs from the Weddell sector, A23a is likely to end up in the South Atlantic on a path called iceberg alley. 

Covering around 4,000 square kilometers, more than four times the size of New York city, and around 400 meters thick, A23a is currently the world’s biggest iceberg. 

Another image, also using aquisitions from Copernicus Sentinel-1, shows how the iceberg rotated and travelled between Nov. 2, 2023 and Nov. 26, 2023. 

Image Credit: (Contains modified Copernicus Sentinel data (2023), processed by ESA) 


October Issue 2023