While a large iceberg was threatening to form from the Halloween Crack or Chasm 1, a new rift suddenly appeared in satellite images in September 2019 just north of these features. The rift zippered across the ice at remarkable speed during the Antarctic summer of 2020–2021. The third major rift in this ice shelf to become active in the past decade, the North Rift lengthened by about 20 km between November 18 and December 22, 2020. It then grew an additional 8 kilometers by January 12, 2021.

Watch the new rift widen and flow westward with the ice shelf in the images. As you flip through, notice the McDonald Ice Rumples remaining stationary.