Antarctic rescue of Akademik Shokalskiy ship begins
The Shokalskiy has been trapped since Christmas Eve by thick sheets of ice driven by strong winds, about 1,500 nautical miles south of Hobart - the capital of the Australian state of Tasmania.
A Chinese helicopter arrived close to the vessel, bringing in a crew to assess the landing situation.
The aircraft left but then returned to begin ferrying the first passengers out to another vessel.
The Shokalskiy has been trapped since Christmas Eve. Its 22 crew are expected to remain on board once the 52 scientists and tourists have left.
The Shokalskiy was trapped by thick sheets of ice driven by strong winds, about 1,500 nautical miles south of Hobart - the capital of the Australian state of Tasmania.
The vessel is being used by the Australasian Antarctic Expedition to follow the route explorer Douglas Mawson travelled a century ago.
"The Chinese helicopter has arrived at the Shokalskiy. It's 100% we're off! A huge thanks to all," expedition leader Chris Turney tweeted.
Turney's post showed a video of a red helicopter touching down on a site that had been marked out by the Akademik's crew.
Members of the helicopter crew checked the site and the aircraft took off again.
Three hours later, Turney tweeted: "The first of the helicopters to take us home. Thanks everyone!"
The Australian Maritime Safety Authority's Rescue Co-ordination Centre (RCC), which is overseeing the operation, had earlier said it was unlikely the airlift would go ahead on Thursday as hoped because of the sea-ice conditions.
The rescue involves ferrying groups of passengers by helicopter to the Chinese icebreaker Xue Long.
The airlift could take about five hours, as the return journey to the Xue Long takes 45 minutes, and five flights could be needed.
The passengers will then be taken by a barge to the Australian icebreaker Aurora Australis.
They are not expected back in Tasmania until mid-January.
Several attempts to break through to the ship by sea - by the Xue Long, Aurora Australis and French-flagged L'Astrolabe - failed because of the thickness of the ice.
Despite being trapped, the scientists have continued their experiments, measuring temperature and salinity through cracks in the surrounding ice.
One of the aims is to track how quickly the Antarctic's sea ice is disappearing.
The ship has plenty of stocks and has never been in danger.
