The ice chunk, measuring some 2,300 feet long with an estimated depth of more than 1,000 feet, caused a stir when it was sighted by experts based on Australia’s remote Macquarie Island.
“I’ve never seen anything like it – we looked out to the horizon and just saw this huge floating island of ice,” said fur seal biologist Dean Miller.
Neal Young, an Australian Antarctic Division glaciologist, said the flat-topped slab could break into dozens of smaller icebergs as it moves in the direction of New Zealand, causing a possible shipping hazard.
“It’s rare to make a sighting like this – it’s certainly impressive-looking,” he said.
He said the iceberg had probably split from a major Antarctic ice shelf nine years ago, and said more could be expected in the area if global warming continues.
“If the current trends in global warming were to continue I would anticipate seeing more icebergs and the large ice shelves breaking up,” he added.
But Professor Jonathan Bamber, from Bristol University, said icebergs the size of Wales can break off the Antarctic and it is too early to say if it is caused by climate change.