Giant iceberg on collision course for South Georgia Island

In 2017 iceberg A68a broke off from the Larsen C iceshelf in Antarctica. For most of the last two years it floated slowly out to sea in relatively slow currents. More recently though it has intersected the Antarctic Circumpolar current and is now on a fast-track course to impact South Georgia Island.

South Georgia is an inhabited island that was where Ernest Shackleton and his crew of shipwrecked explorers finally found rescue over 100 years ago. Though largely uninhabited by humans, there is a vast population of wildlife which would be dramatically affected if the projected impact were to take place in the coming days.

When it originally broke off from Larsen C it was 5,800 kilometers squared in surface area and 144 kilometers long; roughly the size of Chicago, Illinois in the USA and the country of Brunei.

As the iceberg approaches the island it will obliterate the ecosystem on the seabed as it makes it impact, and it is estimates to take up to 10 years to melt away. The islands 2 million penguins risk losing crucial elements of their seasonal food supply, and access to the ocean. As well, phytoplankton production will be disrupted as vast quantities of melted freshwater pour into the surrounding ocean.

A68 is the 5th largest iceberg to break off of Antarctica in the last 30 years; the biggest was B-15 which came from the Ross Ice shelf in 2000. Although A68 is not the biggest known iceberg to calve off in history, it has come from further inland than some of the other large icebergs, and begs the question if climate change is partly responsible for its detachment. The Antarctic continent is generally warming three times the rate of lower latitudes.

As recently as mid-December, A68a has taken a slightly more easterly track, and it is not certain if it will impact South Georgia Island or not. One of the atypical features of this particular iceberg is that it is somewhat thinner than a typical mega-berg, and can therefore be expected to ground itself much closer to islands, because of less ice protruding beneath the surface.

The iceberg is being tracked by the European Space Agency’s Copernicus Sentinel-1, and will be continually monitoring its voyage and glide path.

Sources: Reuters, European Space Agency, Gizmodo,