The world’s largest iceberg is in operation – decades later

The massive iceberg, called A23a, broke off the edge of Antarctica in 1986. But it soon ran aground in the Weddell Sea. There it remained stuck until a few years ago.

– The first movement was noticed in 2020, says Andrew Fleming, a researcher at the British Antarctic Survey, to the BBC.

The iceberg’s area is larger than that of Jutland, which is approximately 3,200 square kilometers, and its thickness is about 400 metres.

These large icebergs come from the massive ice shelves surrounding Antarctica. Ice shelves form when the ice sheet flows toward the coast and sea, Nina Kirchner, lecturer in glaciology and director of the Tarvala Research Station at Stockholm University, tells TT.

I started moving

In recent months, A23a has begun to move a little faster due to currents and winds.

That the iceberg is starting to move again after being stuck since 1986 is not surprising.

– Sooner or later, even these huge mountains will always disintegrate. It breaks down slowly, but it is a huge iceberg, so it takes a long time, Ola Kalin, an oceanographer at SMHI, tells TT.

He says it was likely the effect of heat from ocean currents that was causing the iceberg to erode from below and from the side, meaning it is now loose.

It eventually dissolves

The iceberg is now likely to drift into an area north of the Antarctic Peninsula where many icebergs accumulate. In this case, it is caught by a strong ocean current.

– It rotates clockwise around Antarctica. There, they are transported offshore and towards warmer waters, breaking down and dissolving over time, says Ola Kalin.

Another possibility is that A23a could get stuck again, but this depends on what the bottom conditions look like and how the currents are going.