Expedition scientists on board a vessel in Antarctica have embarked on the last stage of their voyage — the search for the wreck of the steam-yacht Endurance, which was abandoned by the British polar explorer Ernest Shackleton in 1915 when it was crushed by sea ice.

They are just a few days away from the spot where the shipwreck is thought to lie at the bottom of Antarctica's Weddell Sea. [In Photos: Searching for Shackleton's 'Endurance' Shipwreck]

The expedition members, on board the Dutch research vessel Agulhas II, recently completed their scientific tasks on the voyage by surveying the storied Larsen C ice shelf alongside the Antarctic Peninsula and the gigantic A-68 iceberg that separated from it on July 12, 2017 — when what started as an enormous crack in Larsen C culminated in the separation of a Delaware-size, trillion-ton iceberg drifting through the Weddell Sea.

Now, the Agulhas II is making its way through heavy sea ice to the last known location of the Endurance, which the members of Shackleton's expedition carefully recorded using astronomical sightings.

The Dutch science research vessel Agulhas II has been in the Weddell Sea for about a month, surveying the newly exposed region beside the Larsen C ice shelf. (Image credit: Pierre Le Gall/Weddell Sea Expedition 2019)

British maritime archaeologist Mensun Bound, who heads the expedition's exploration phase, said the team is hopeful about finding the historic shipwreck — about 75 miles (120 kilometers) from their ship's present location — thanks to a break in the weather.

"Although the odds of success were initially against us, the mood within the team is upbeat given the favorable ice and weather conditions, which we think will allow us to reach the search area,' Bound said in a statement.

Antarctic survival

Shackleton led the expedition in 1914 in the hopes of crossing Antarctica, but the ship became trapped in the ice in February 1915. The expedition members stayed with the ship until it was crushed by the ice and sank that November.

Shackleton and the 27 expedition members then spent several months trekking across the sea ice and floating on ice floes, until they finally escaped in the ship's lifeboats, which they had recovered from the wreck, to Elephant Island, near the northern tip of the Antarctic Peninsula. [Icy Images: Antarctica Will Amaze You in Incredible Aerial Views]

Most of the crew sheltered there, surviving on seal meat, while Shackleton and five others navigated in a small lifeboat for 800 miles (1,280 km) to a whaling station on the subpolar island of South Georgia, arriving in May 1916.

Shackleton then made four attempts to rescue the remaining crew at Elephant Island. At the end of August 1916, he succeeded in doing so in a Chilean steam tug. Shackleton and all 27 members of the expedition survived the ordeal.

Shipwreck under ice

The researchers on board the Agulhas II hope to deploy an autonomous underwater vehicle (AUV) to search the seafloor for the shipwreck.

It is not known if the wreck is currently covered by a layer of sea ice or not, but the researchers hope the AUV and the detailed records left by Shackleton's expedition will help them locate the historic wreck in any case.

Meanwhile, scientists on board the Agulhas II are celebrating their successful voyage to the edge of the Larsen C ice shelf — a British expedition had to turn back last year because of bad weather and heavy sea ice.

"We have acquired detailed observations on the glaciology, oceanography, biology and geology of the little-known area around the Larsen C ice shelf and the huge A-68 iceberg," said Julian Dowdeswell, the director of the Scott Polar Research Institute at the University of Cambridge in the U.K.

"Analysis of this data will allow us to better understand the contemporary stability and past behavior of Larsen C, with its wider implications for ice-sheet stability more generally," he said.

Original article on Live Science.