To keep photographic film fresh, professional photography shops store film stock inside large refrigerators. For long-term storage, film manufacturers suggest freezing film if storing for six months or longer at zero degrees Fahrenheit. The power of cold storage for preservation cannot be overstressed; in 2013, 100-year-old negatives from the most famous, and ill-fated, polar expeditions in history were discovered frozen in ice on Antarctica.

The Shackleton expedition began in 1914, when Ernest Shackelton set out with his crew to cross Antarctica on foot—a feat that no one had ever achieved. One group, led by Shackleton, planned to enter the continent from South Georgia, while the other group, The Ross Sea Party, created a supply route from the continent’s Australian side. The plan was for the two crews to meet in the middle, but unfortunately, they never made it.

Shackleton’s ship Endurance became stuck in pack ice for nine months. Eventually, the crew abandoned ship to walk over the thick ice that had formed. Three days later, the ship sank and the group set up camp to wait out the blizzard-like conditions. Several months later, food rations dwindled and the situation became dire. The crew took three lifeboats to Elephant Island, landing on the shores of South Georgia a few weeks later. Twenty-two months after launching the expedition, they were back in South Georgia and the mission was considered a failure. Miraculously, there were no fatalities.

Meanwhile, the Ross Sea Party was setting up supply routes. They too encountered numerous disasters, including the sinking of their ship during a blizzard, leaving the crew stranded on Antarctica. The group was eventually rescued, only after several members of their crew died during the expedition.

100 years later, conservationists of the New Zealand Antarctic Heritage Trust were restoring exploration huts in Antarctica when they discovered a box of cellulose nitrate negatives made by the crewmembers of the Ross Sea Party. The identity of the photographer is unknown, but the expedition’s official photographer was Arnold Patrick Spencer-Smith, and the photographs are thought to be his.

When unfreezing film, it is critical to allow it to warm up by 25 degrees Fahrenheit, which could take approximately three hours for 35mm film. This must be done slowly and carefully so as not to risk cracking and breaking the brittle film. This particular restoration involved larger sheets of film. Restorers carefully separated the negatives from each other, cleaning and removing the mold, and then consolidating the cellulose nitrate image layers. Each negative was then turned into a digital positive.

Despite having been frozen in ice for a century, the team successfully restored 22 photographs, revealing never-before-seen evidence of the historic expedition. The photographs were found in the hut of Captain Robert Falcon Scott and include images of icebergs, portraits of explorers, and a candid look of life in the arctic waters. The photographs can be viewed at the New Zealand Antarctic Heritage Trust.

Kat Kiernan is the Editor-in-Chief of Don’t Take Pictures.