WASHINGTON – One of the biggest icebergs ever recorded has broken off an ice shelf in the West Antarctic, researchers said Wednesday.
Researchers led by the University of Swansea in Wales monitored the progress of a 106-mile-long break in the ice shelf throughout the Antarctic winter – using the European Space Agency Copernicus Sentinel-1 satellites – in anticipation of the ice breaking off.
Researchers reported the rift rapidly advanced in January, May and June, so the break – known as calving – was believed to be imminent, researchers said earlier this month.
“The calving occurred sometime between Monday, July 10 and Wednesday, July 12, when a 5,800-square kilometer [2,200-square mile] section of Larsen C [ice shelf] finally broke away,” Swansea University said Wednesday in a statement, after scientists examined the latest satellite data from the area.
The final breakthrough was detected in data from NASA’s Aqua MODIS satellite instrument and confirmed by NASA’s Suomi VIIRS instrument.
The iceberg, which is expected to be named A68, is predicted to be one of the 10 largest ever recorded. It weighs a whopping 1 trillion tons and is 2,240 square miles – roughly the size of Delaware or four times the size of London, according to the researchers.
Icebergs regularly calve in Antarctica but because this one is so massive, it will be closely watched as it travels for any risk to shipping traffic.
“It may remain in one piece but is more likely to break into fragments. Some of the ice may remain in the area for decades, while parts of the iceberg may drift north into warmer waters,” Adrian Luckman of Swansea University, lead investigator of Project Midas, said in a statement released Wednesday. Project Midas is a UK-based research project that studies the effects of global warming on the Larsen C ice shelf.
“The iceberg weighs more than a trillion tons, but it was already floating before it calved away so has no immediate impact on sea level,” the research team said.
But if the glaciers that were held in check by the iceberg now split into the Antarctic Ocean, the global water mark could be lifted by about 4 inches, according to researchers.
Also, the calving may have increased the risk of the remaining ice shelf disintegrating, the Swansea team said. The ice shelf has now decreased by 10 percent and is in the most retreated position ever recorded, scientists said.
The Larsen A ice shelf collapsed in 1995 and the Larsen B shelf abruptly broke away in 2002.