Ice Cathedral adrift over the ocean

Ice Cathedral adrift over the ocean

Metre-high waves cut arcs into the largest iceberg in the world (more than twice the size of London). The result was captured with drones by photographers on board a ship from the company EYOS Expeditions. The large iceberg with the rather technical name ‘A23a’ is rapidly drifting northwards away from Antarctica, melting due to warm air and warm surface water.

A23a was released as early as 1986. It calved from the floating Filchner Ice Shelf in West Antarctica, but due to its thickness (about 400 meters; the height of the Empire State Building) it almost immediately became stuck behind the ocean floor of the Weddell Sea, south of South America .

Photo Rob Suisted

But after almost four decades, satellite images showed that the iceberg is now moving, from the Weddell Sea towards the Southern Ocean. Presumably he was now able to break free from the muddy ocean floor because the ice floe became thinner at the bottom. According to the last measurement, the mountain floats at an altitude of about 60° south latitude. In 1990 and 2019, researchers reported Antarctic icebergs (C-02 and A-57a) reaching about 42.5° south latitude – the latitude where Tasmania is also located.

Like most icebergs in this area, A23a is likely to drift with the strong ocean currents, along a route called the ‘iceberg avenue’.

Image ESA

Source of nutrients

Scientists use satellites to monitor the iceberg’s route, because it can be risky for shipping. And if he gets stranded on an island, he could endanger a penguin colony. On the other hand, the meltwater is a source of nutrients for ocean life.

Although calving is a natural process, global warming is accelerating the process. Climate scientists are concerned about the ice in and around Antarctica. Last year there was the smallest amount of sea ice ever measured around Antarctica. In July (winter at the South Pole), the ice grew back extremely slowly. Compared to normal, an area sixty times less in the Netherlands grew.

Photo Ian Strachan / EYOS Expeditions / AFPS




SCIENCE