An iceberg the size of Greater London broke off the Brunt Ice Shelf in Antarctica on Sunday, according to the British Antarctic Survey.
Scientists first discovered significant cracks in the ice shelf a decade ago, but there have been two major breaks in the past two years. The BAS Halley Research Station is located on the Brunt Ice Shelf and glaciologists say the research station is safe.
The iceberg is about 600 square miles, or 1550 square kilometers. The researchers say this event was expected and not a result of climate change.
“This calving is expected and part of the natural behavior of the Brunt Ice Shelf. It is not linked to climate change. Our science and operations teams continue to monitor the ice shelf in real time to ensure it is safe and to maintain the delivery of the science we undertake at Halley,” Professor Dominic Hodgson, a BAS glaciologist, said in a press release.
The calving comes amid a record low sea ice in Antarctica, where it is summer.
“While the decline in Antarctic sea ice always declines sharply at this time of year, it has been unusually rapid this year,” scientists at the National Snow and Ice Data Center reported in early January, “and in late December, Antarctic’s extent of sea ice was the lowest in the 45-year satellite record.”
Researchers at the data center say the low sea ice is due in part to a large band of warmer-than-normal air temperatures, which rose to 2 degrees Celsius above average over the Ross Sea in November and December. Strong winds have also accelerated the decline of sea ice, they reported.
Recent data shows that sea ice has not recovered since then, suggesting the continent could end the summer with a new record on the books for the second year in a row.
Antarctica has experienced a roller coaster of sea ice over the past few decades, swinging wildly from record highs to record lows. Unlike the Arctic, where scientists say climate change is accelerating impacts, the extent of sea ice in Antarctica is highly variable.
“There is a connection between what’s going on in Antarctica and the general warming trend in the rest of the world, but it’s different from what we’re seeing in mountain glaciers and what we’re seeing in the Arctic,” said Ted Scambos, a glaciologist at the University of Colorado Boulder and chief scientist at the National Snow and Ice Data Center, previously told CNN.
Satellite data dating back to 1978 shows that the region continued to produce record high amounts of sea ice in 2014 and 2015. Then it suddenly collapsed in 2016 and has remained below average ever since.