And that is certainly not the first time!

On the east coast of Antarctica, we find the Conger Ice Shelf: a mass of ice resting on the water that originated where the Conger Ice Shelf flows into the sea. The ice shelf has struggled for decades in a row; satellite images reveal that it has become much smaller in recent decades. And last month it was announced that the ice shelf – still quite unexpectedly – has completely disintegrated.

Island

It is always sad to see on satellite images how mighty ice shelves pulverize. But when it comes to the Conger Ice Shelf, the sad satellite images seem to have another surprise in store for us. In the images, for example, an island that was unknown to us until recently appears to be popping up.

Consistent

The ice-covered island is said to have been part of the mighty Conger Ice Shelf. When that ice shelf disintegrated and its fragments drifted away or melted, a striking circular remnant of ice bravely held out. It didn’t shrink or change shape—even when large icebergs created by the ice shelf breakup collided with it.

It leads researchers to the tentative conclusion that it must be an island. This is further supported by the fact that this bravely enduring patch of ice is remarkably high; it would in any case extend up to 35 meters above sea level in part.

Image: Joshua Stevens/Landsat data from US Geological Survey (via NASA Earth Observatory†

ice island

For now, researchers suspect that it is an ‘ice island’: a large, heavy ice sheet that is firmly anchored on a mountain hidden below sea level. At the moment, that ice sheet appears to be quite capable of sustaining itself. That means that the melt that occurs below sea level is compensated by the snow that falls on the island. However, it has not been proven that this will remain the case, according to researcher John Gibson, who works at the Australian Antarctic Division† For example, because the snowfall is less, the ice sheet can gradually become thinner and float away. “The island with no name is a more or less permanent feature in the landscape, but one day the ice may break away from the underlying rock and become an iceberg.” And then we have lost the island – which only exists by virtue of the ice that rests on the undersea mountain.

The islet (slightly top left center of the photo) is also visible on satellite images taken after the complete disintegration of the Conger Ice Shelf. Image: Lauren Dauphin (via NASA Earth Observatory†

Candidate

It is important to emphasize that the unnamed island is still a candidate island; although satellite images strongly indicate that solid ground lies directly beneath the ice, this has not been proven. “To be really sure, you’ll have to put a ship next to it and search for underlying rock and perhaps also determine the thickness of the ice using a radar system,” said glaciologist Christopher Shuman, of NASA’s Goddard Space Flight Center† That said, he is already quite convinced that we are dealing with an island here. For example, he points out again that satellite measurements indicate that its surface towers far above sea level.

Moreover, it would not be the first time that researchers encounter new islands with the erection of ice shelves. For example, in 2020 the island of Sif (see images below) was discovered. “The island was covered in the past by an ice shelf — glacial ice that flowed out toward the ocean and started floating on the water,” Julia Wellner told me at the time. Scientias.nl† “The island has always been above sea level, but we never saw it because it was under the ice. However, the ice shelf has retreated in recent years, exposing the island.” And years before that, a new island was discovered in the waters that were once the domain of the now completely disappeared Larsen B ice shelf, which later even got an official name: IJsbreker Eiland.

Whether the alleged island that has now been discovered off the coast of Antarctica deserves its own name, therefore, remains to be seen. What is certain for researchers like Wellner is that it seems unlikely that the islet is the last in a series of islands recently uncovered by languishing ice shelves. “It’s certainly possible that more new islands will be discovered as the ice retreats faster and faster.”