World’s Largest Iceberg A23a Halts Near South Georgia

Image credit: gCaptain.

A23a, the world’s largest and oldest iceberg, has run aground near South Georgia Island, the British Antarctic Survey (BAS) confirms.  

The Iceberg’s Journey:

• A23a calved from Antarctica’s Filchner Ice Shelf in 1986.  
• It remained stationary in the Weddell Sea for over three decades.
• In 2020, it began drifting with Southern Ocean currents.
• It now sits approximately 90km from South Georgia Island.

Current Status:

• Dr. Andrew Meijers reports that the iceberg maintains its structure.  
• He predicts it will likely break up due to increased stress from grounding.
• In 2024, a Taylor Column temporarily immobilized the iceberg.  

Potential Impacts:

• Researchers don’t expect significant impacts on South Georgia’s wildlife.
• The berg may create challenges for commercial fishing operations due to smaller, harder-to-track ice fragments.  

Scientific Monitoring:

• Scientists are closely monitoring A23a to study its environmental effects.  
• Nutrients from the grounding and melt may boost the local ecosystem.  
• The British Antarctic Survey collects data to understand how “megabergs” influence the ocean.  

Climate Change Context:

• While A23a is not directly linked to climate change, ice shelf mass loss has accelerated since 2000.
• This mass loss, attributed to climate change, impacts ocean circulation and sea level rise.  

Future of A23a:

These smaller icebergs will ultimately melt.

Warmer waters, waves, and tides will eventually break the iceberg into smaller pieces.