An Illawarra scientist and a University of Wollongong historian are among a group of Australian explorers stranded near Antarctica after their ship became wedged in by thick sheets of sea ice.
Rescue ships headed to the Russian liner won't reach the stricken vessel until at least tonight, federal authorities said.
There are 50 tourists, scientists and explorers and 20 crew on the Russian ship MV Akademik Shokalskiy, which is on a Spirit of Mawson voyage along the edge of Antarctica.
University of Wollongong historian Ben Maddison and scientist Chris Turney, who lives in the Illawarra, are on the voyage.
Three ice-breaking ships have been sent to assist in the remote location more than 1500 nautical miles south of Hobart, after a distress call was sent on Christmas morning.
Australian Maritime Safety Authority spokeswoman Andrea Hayward-Maher said the ships still had some way to travel before reaching the trapped vessel.
"It is literally a very, very long way away," Ms Hayward-Maher said.
"The first vessels that have been tasked to respond won't be on the scene until the earliest late tomorrow [Friday] night."
She suspected "fast flowing ice" had caused the vessel to get stuck.
"The ocean is inherently unpredictable, and if there's different currents ... these sorts of things can happen," she said.
The Australian Maritime Safety Authority has previously said that those on board the ship are not in danger.
Yesterday Professor Turney wrote on Twitter: "An update from the AAE. We're in a blizzard at the moment but all are well. Blowing through later."
In a video posted to YouTube yesterday afternoon, Prof Turney said a low pressure system was sitting over their expedition vessel with wind speeds reaching in excess of 70km/h.
"The vessel hasn't moved in the last two days and we're surrounded by sea ice - we just can't get through," Prof Turney said in the video taken yesterday.
"In 24 hours' time we're expecting a Chinese ice-breaker, Snow Dragon, to arrive and break open the path to get us all home."
He said everyone was safe.
The voyage is part of a research expedition to commemorate the centenary of Douglas Mawson's exploration, and had sailed from New Zealand to visit several sites.