Antarctica’s Brunt Ice Shelf, the largest in the world, will soon lose a 660 square mile, almost 500 feet thick segment of ice—almost twice the size of the city of New York. The shelf is named for David Brunt, a British meteorologist and Physical Secretary of the Royal Secretary who organized the Royal Society Expedition to the Brunt Ice Shelf in 1955.
Two cracks in the shelf have been getting wider over the past few years. This process is known as calving: the splitting and shedding of ice chunks from the edge of a glacier. Glaciologists label these cracks or crevasses in the ice sheet as chasms. Chasm 1, the first fault line on the Brunt Ice Shelf, has been present and stable for over 35 years. But just lately, this crack has been edging north as fast as 2.5 miles a year. The second break, known as the Halloween crack, is upstream from what scientists call the McDonald Ice Rumples. These rumples form when the bottom of the ice shelf, which flows downhill toward the ocean, runs up against an underwater ridge. Chasm 1 is currently about 2.5 miles away from the McDonald Ice Rumples. Soon enough these two cracks will likely intersect, creating a massive iceberg that will begin to slowly float away from Antarctica.
Scientists closely observe the Brunt Ice Shelf with instruments measuring the distortion of the ice day by day. With the help of satellite images, ground penetrating radar and on-site drone footage, scientists have been able to track the progress of Chasm 1 and the Halloween crack.
This gigantic iceberg could elevate water levels enormously. According to National Geographic, rising sea levels could produce devastating effects on coastal areas, causing wetland flooding, aquifer and agricultural soil contamination with salt, destructive erosion, and habitat loss for fish, birds and plants. In the unlikely event that all the ice sheets and glaciers on earth melted, sea levels would rise by 216 feet.
This iceberg is not even the biggest to break off of the continent of Antarctica. In 2017, a glacier the size of Delaware broke off of the Larsen-C ice sheet:around 2,250 square miles in size. The biggestchunk to break off is Iceberg B-15. It measured around 4,200 square miles, larger than the island of Jamaica. It broke off from the Ross Ice Shelf in March 2000.
The Brunt Ice Shelf is not a stranger to cracks. Cracks that form during the summer have the potential to heal again over the winter months. Though cracks are common in ice shelves, the imminent calving of the Brunt Ice Shelf is unpredictable. The potential 660 square mile iceberg could raise sea levels drastically, impacting our coastal habitats and ultimately posing dangers to human health.
AMELIA BAUMANN is an aspiring writer and editor from New Jersey. I love to travel and am intrigued with the diversity of culture around the world. I am passionate about our environment and especially keeping our oceans clean.