TechAntarctica's largest iceberg, A23a, begins drift after 30 years

Antarctica's largest iceberg, A23a, begins drift after 30 years

The largest iceberg in the world moved after 30 years.
The largest iceberg in the world moved after 30 years.
Images source: © Adobe Stock

3:56 PM EST, November 25, 2023

According to the Antarctic Survey organization, the world's largest iceberg, A23a, has started to drift away from Antarctica. This ice block, which is eight times larger than Warsaw, began to move after three decades of inactivity. It is currently heading toward the Atlantic waters and has reached the northern edge of the Antarctic Peninsula.

A23a was once a part of the Filchner ice shelf but broke off in 1986. Rather than drifting toward warmer waters and melting, it lodged into the seabed mud in the Weddell Sea, where it has remained a relatively stable ice island for around 35 years.

Separation of Iceberg A23a from Antarctica

A significant development occurred in 2020. Scientists from the British Antarctic Survey observed that the previously stationary A23a iceberg started showing signs of drifting.

In recent months, wind and ocean currents have caused A23a to drift more aggressively. It's now passing the northern edge of the Antarctic Peninsula. As such, it's expected that the Antarctic Circumpolar Current will push it towards the South Atlantic.

This pattern of self-destruction is typical for icebergs from the Weddell Sea region. As they drift away from Antarctica, they sail into progressively warmer waters and eventually melt. A23a's massive size indicates that its journey may be complex, but a disastrous end is not anticipated.

About Iceberg A23a

The drifting of A23a is not a surprising event. It's a normal phase in an iceberg's life cycle, with the formation of these icebergs being a natural phenomenon. A23a was formed due to glacier calving.

It's an unusually large iceberg because, instead of dividing into smaller pieces, it has remained intact for several decades. As a result, it is currently the largest iceberg in the world, though not the largest ever recorded.

The birth of iceberg A23a as a result of the calving of the Filchner glacier
The birth of iceberg A23a as a result of the calving of the Filchner glacier© USGS, Landsat

In November 1956, an even larger iceberg was spotted in Antarctica. Although no satellite documentation exists, it's estimated that it was approximately 208.16 miles long and 41.63 miles wide, covering an area of about 11,969.11 square miles.

While the melting of A23a could be rapid, it could have beneficial side effects. Its path cuts through South Georgia, a breeding ground for millions of seals and penguins. While the melting could pose a threat to these animals, it could also release nutrient-rich mineral dust, which could support the surrounding Antarctic fauna and flora.

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