“Another Large Iceberg Breaks Off From Brunt Ice Shelf in Antarctica”
Scientists were alerted to the formation of a massive new iceberg after a large chunk broke away from Antarctica’s Brunt Ice Shelf last week. Dubbed A-83, the iceberg measures approximately 375 square kilometers in size. Researchers have been monitoring signs of instability in this region, known as the “Halloween Crack”, which has spawned multiple iceberg calving events in recent years.
The Halloween Crack first emerged in October 2016 and runs along the floating portion of the Brunt Ice Shelf. It received its name due to being discovered around Halloween that year. Glaciologists have observed the long split progressing over time, noting it passes close to an already fragile tip of the ice shelf. If this tip eventually detaches, it could set adrift an iceberg covering around 1750 square kilometers in expanse.
While iceberg calving is a natural process, scientists say the Brunt Ice Shelf has shown vulnerability to the same pressures impacting Antarctica wide. Factors like low sea ice levels mean ice shelves have less protection from disruptive winds and waves. The ice in this area also flows over underwater high points in the seabed called “McDonald Ice Rumples”, which causes stress fractures and rifts to form on the surface over time.
By monitoring events like the recent shedding of A-83, researchers aim to better understand how Antarctica’s icy barriers are responding to the changing climate. Though calving alone does not signify instability, it provides clues regarding the stresses impacting these crucial buffers between glacial ice sheets and ocean waters.
