Did you know South Asia was once part of Africa? Millions of years before you were born, the landmass you know today as India, Pakistan, and Bangladesh broke from Africa and drifted toward its present location. Imagine if you could witness something like that.
Well, now you can! The colossal iceberg A23a, the biggest on Earth, is making headlines as it breaks free from the Antarctic sea floor, slowly migrating from the Weddell Sea into the Southern Ocean. This gargantuan block of ice, measuring approximately 3,800 square kilometres — is bigger than 29 countries, such as Luxembourg, Bahrain, and Singapore — and stands around 400 meters tall.
Experts are amazed and afraid as they track this block of ice, only to see it disappear in years to come as it will come in contact with warmer currents and melt. And you, our readers, will certainly have the front-row seats to witness: this is how real climate change gets!
The A23a first broke from Antarctica’s Filchner Ice Shelf in 1986 and remained relatively stationary, grounding itself on the seabed of the Weddell Sea. Here, it remained until 2016, when it broke again — this time getting stuck in a Taylor column, which is a spinning vortex of water. The ocean currents, when they hit an underwater mountain, create this vortex. And this is what weakened the ground for A23a to break free.
Recent satellite tracking by the British Antarctic Survey (BAS) reveals that the iceberg is on a northward trajectory driven by ocean currents. It will likely take a path through the iceberg alley towards South Georgia Island. This region has seen similar icebergs stranded or broken apart under warmer conditions. For nature fans, we think South Georgia should be on your bucket travel list in the coming years.
What makes the breaking of this iceberg more fascinating than others is climate change. An iceberg of this magnitude can affect local ecosystems, water salinity, and marine life, so it requires constant monitoring to prepare for any and all eventualities. The movement of A23a is being closely monitored for scientific and ecological reasons.
Dr. Andrew Meijers, Polar Oceans Science Leader at BAS, recalled the sentiments of his team aboard the RRS Sir David Attenborough, a research vessel near the iceberg. He said they were fortunate to witness the block of ice and its sheer size, reminiscing that it was as far as the eyes could see. In his words:
“It’s exciting to see A23a on the move again after periods of being stuck. We are interested to see if it will take the same route the other large icebergs that have calved off Antarctica have taken. And more importantly, what impact this will have on the local ecosystem.”
Dr. Andrew’s team is leading the study on A23a and has collected seawater samples for the next step of the analysis. Laura Taylor explains,
“We know that these giant icebergs can provide nutrients to the waters they pass through, creating thriving ecosystems in otherwise less productive areas. What we don’t know is what difference particular icebergs, their scale, and their origins can make to that process.
We took samples of ocean surface waters behind, immediately adjacent to, and ahead of the iceberg’s route. They should help us determine what life could form around A23a and how it impacts carbon in the ocean and its balance with the atmosphere.”
We are certainly living in interesting times. The science behind climate change is real and fascinating, even if certain world leaders continue to dismiss it as a conspiracy. Icebergs breaking free is not a new phenomenon. However, A23a gets more traction as people become increasingly aware that sea currents are getting warmer, temperatures are rising, and our actions are accelerating such events. The scientific study of A23a will further empower the understanding of nature, a lens into its critical processes and progression.
