An expedition to find Ernest Shackleton's lost ship the Endurance was called off this week.
CNN  — 

The team of the Weddell Sea Expedition aimed to locate the Endurance, the ship famously lost to the ice in 1915, during Ernest Shackleton’s attempt to make the first land crossing of the Antarctic. The search was called off this week, however, after marine archaeologists’ own underwater vehicle succumbed to the Weddell Sea ice.

An international team of marine archaeologists, glaciologists, oceanographers and marine biologists launched the expedition on January 1 to study the Larsen C ice shelf, from which a trillion-ton iceberg broke away in July 2017. While in Antarctica, they hoped to find the wreck of the Endurance, an enticing secondary pursuit alongside their main project.

An autonomous underwater vehicle, AUV7, was deployed earlier this month at the wreck site of the Endurance, which sank after the Antarctic ice enclosed and ultimately crushed it. But the vehicle, which the scientists had hoped would locate and photograph the lost ship, slipped under an ice floe and out of contact.

The expedition team undertook a round-the-clock rescue operation to recover the AUV. Weather conditions worsened, however, and the team was forced to abandon the search after several days – lest the polar research vessel S.A. Agulhas II, the expedition hub, meet a similar fate to the Endurance.

Expedition spokesperson Mark Antelme told CNN: “It’s a reminder of what Shackleton and his team experienced in terms of the harshness of the environment.”

The Weddell Sea Expedition team abandoned the search for the Endurance, fearing the S.A. Agulhas II would become trapped in the ice.

British explorer Ernest Shackleton and his crew set out on the Imperial Trans-Antarctic Expedition in 1914. Shackleton planned to sail to Antarctica’s Vahsel Bay before leading a journey across the continent, via the South Pole, on foot.

The expedition was thwarted by the Weddell Sea, however, as the waters around the Endurance froze. After abandoning the ship, the crew survived in makeshift camps for an improbable 17 months, after which they were rescued from the remote Elephant Island.

The failure of the Weddell Sea Expedition to find the sunken wreckage was “really disappointing,” Antelme told CNN, adding, “We don’t know whether that AUV had in fact recorded images of Endurance, which is very frustrating.”

The study of the Larsen C ice shelf, however, went more smoothly. The team hopes the ice shelf “will be able to provide some insight into global warming and climate change,” Antelme said.