'This is weird, it's strange'

Sea ice has fallen so fast from record highs that it has left the continent exposed to destructive elements and scientists are baffled

- Graham Readfearn

Most mornings since the end of March, before Will Hobbs has done much at all other than make a coffee, he scrolls his inbox looking for one particular email.

Generated and sent automatically from a colleague, the email arrives just after 4am and gives the latest data from a US government satellite showing how much sea ice is floating around Antarctica.

"Unprecedented is a word that gets bandied around a lot, but it doesn't really get to just how shocking this is," said Hobbs, a sea ice scientist at the University of Tasmania. "It is very much outside our understanding of this system." In February, the floating sea ice around Antarctica hit a record low for the second year running. Since satellites started tracking the region's ice in 1979, there had never been less ice.

As it does every year, as the temperatures around the continent plunged towards winter, the sea ice started to return. But the moderate alarm from scientists at that record low has turned to astonishment. Some are worried they could be witnessing the start of a slow collapse of Antarctica's sea ice.

By August, there would usually be about 16.4 million sq km of Antarctic sea ice. But last week, there was just 14.1 million sq km. An area bigger than Mexico has failed to freeze.

"There's a sense that something weird is going on. It's dropping way below anything we have seen in our record," said Dr Walt Meier, a senior scientist at the National Snow and Ice Data Centre (NSIDC) at the University of Colorado.

Meier's job is to help collate and present data from US satellites that have been recording sea ice since November 1978. It is the same data that gets presented in Hobbs' daily email and the same data that has been turned into charts and spread on social media around the world in recent weeks.