Halloween Crack for Halloween

Marking Halloween, we bring you this recent Copernicus Sentinel-2 image of the Halloween Crack in Antarctica.

First spotted on 31 October 2016, the Halloween Crack runs from an area known as McDonald Ice Rumples – which is where the underside of the floating ice sheet is grounded on the shallow seabed. This pinning point slows the flow of ice and fractures the ice surface.

The Halloween Crack, which is currently stable, runs adjacent the more precarious tip of Brunt Ice Shelf. This tip of the shelf is hanging by a thread – now only held in place by a narrow strip of ice around 600 m long at the northern end of the long chasm cutting through the western and remaining eastern part of the ice shelf. If and when this potential rupture point finally gives way, it is expected to spawn a huge iceberg about 1750 square kilometres, which is over five times bigger than the size of Malta.

Ice shelves float so when they calve icebergs the bergs do not actually add to sea-level rise. However, ice shelves act as a brake on how fast the glaciers on the land flow to the sea. Owing to climate change, Antarctica’s ice shelves are weakening, leading to greater risks of more land ice ending up in the oceans and thereby adding to sea-level rise, something arguably more frightening than Halloween.

Routine monitoring by satellites with different observing capabilities offer unprecedented views of events happening in remote regions like Antarctica, and how ice shelves are coping in response to changes in ice dynamics, air and ocean temperatures.

Zoom in to see this Copernicus Sentinel-2 image at it full 10 m resolution. The image was captured on 25 October 2022.