Glaciologists have been expecting this type of event for a decade.
An iceberg bigger than New York City broke an ice shelf in Antarctica, scientists say.
The 490 square mile glacier has separated from the Brunt ice shelf, where the British Antarctic Survey’s Halley research station is located, the research organization announced. New York City is approximately 302 square miles.
Glaciologists have been expecting a major birth event for at least a decade, according to BAS. The first indication that the glacier was going to break was in November, when a new chasm called the North Rift – the third large crack to become active on the ice shelf in the last 10 years – headed for another chasm about 20 miles away. distance.
The crack then pushed more than 800 meters a day to the northeast from January, cutting through the 490-foot-thick ice shelf, the scientists said. The iceberg formed when the crack widened on February 26, freeing it from the ice shelf.
“Our BAS teams have been prepared for the birth of an iceberg on the Brunt ice shelf for years,” said British Antarctic Research director Dame Jane Francis in a statement.
BAS monitors the ice shelf daily using an automated network of high-precision GPS instruments around the station, which measure how the ice shelf is deforming and moving. Satellite images from the European Space Agency, NASA and the German TerraSAR-X satellite are also used, said Francis.
The impact of childbirth on the ice shelf is unclear, the scientists said. In the coming weeks or months, the iceberg may move or may run aground and remain close to the ice shelf, Francis said.
The BAS research station is currently closed for the Antarctic winter and is unlikely to be affected by the birthing event, the scientists said. BAS said the station was moved inland in 2016 to “avoid the paths” of two chasms called “Chasm 1”, which formed in 2012, and “Halloween Crack”, which formed in 2016. None of them grew over the past 18 months.
British Antarctic Research Operations Director Simon Garrod said in a statement that changing the station was a “wise decision”.
“Our job now is to keep an eye on the situation and assess any potential impact of the current birth on the remaining ice shelf,” said Garrod. “We continually review our contingency plans to ensure the safety of our staff, protect our research station and maintain the delivery of the science that we carry out at Halley.”
Employees have only been hired at the Antarctic BAS station during the summer, since 2017, due to the difficulty of evacuation during the dark winter months, when the sky is pitch black.