Mawson’s Huts at Cape Denison (Photo: Geoff Ashley/Mawson’s Huts Foundation)

One of the many problems with maintaining a tourist attraction in Antarctica is that an iceberg might block the access of the people who are trying to visit.

At least, that’s what happened to Mawson’s Huts, the site of four huts that Douglas Mawson and his crew erected in 1912 for their Australasian Antarctic Expedition. After the Mawson’s Huts Foundation restored the huts, in the late 1990s, cruise ships used to bring passengers to Cape Denison during the summer to visit the hut.

“Once we had done the initial work on the huts, they became a popular tourist destination,” says David Jensen, the chairman and CEO of the foundation. (Popular for Antarctica, at least: three different cruise companies would bring visitors to the site.)  But five years ago, an iceberg wedged itself against the ocean floor right at a point where it blocked access to the bay on which the huts are located. Since then, access has been limited, although last summer—that’s December through March in the southern hemisphere—the ice started breaking up. “There is a cruise book shop booked to visit the huts of January of next year,” says Jensen. “And we’re hoping the sea ice will again break up.”

But limited access is just one of the challenges that face preservationists of polar heritage and archaeological sites. The small structures and evidence that humans ever visited the extremes of our planet are in danger of disappearing — and, in some place, climate change is making all the more likely that they’ll be lost altogether.

Inside Robert Falcon Scott’s hut, in 2000 (Photo: Kuno Lechner/Wikimedia)

Polar preservation is a relatively recent concern: the first humans to reach the South Pole made it there barely more than a century ago, and though the people who explored these regions did want to leave some evidence of their achievements, immediate survival was often a more pressing concern. But the past couple of decades, as polar tourism has increased and territorial claims gone unresolved, heritage sites in the polar regions have been officially recognized and legal protections put in place. Norway, for instance, protects all human sites predating 1946 on the Arctic archipelago of Svalbard, and under the Antarctic treaty, 90 historic sites and monuments have been recognized—flag masts, rock cairn, sledges, cemeteries, and the huts and tents of polar explorers. It’s illegal to damage, remove, or destroy these sites.

Protecting polar sites from people, though, isn’t always enough to preserve them. Because Antarctica is dry, buildings there don’t decay particularly quickly. But they can be threatened by the ice that builds up along the outside wall, on the roof, and inside. They can trap just enough moisture, too, for decay to start setting in. In the past two decades, organizations like Mawson’s Hut Foundation have been created to do the work of keeping these buildings in tact.

The most visible of these efforts is the Antarctic Heritage Trust, which oversees the conservation of huts used by some of the continent’s most famous explorers, including Robert Falcon Scott, Edmund Hillary, and Ernest Shackleton. Since the beginning of the 2000s, the trust has made a significant push to conserve the huts and artifacts found in the Ross Sea region, which has meant chipping away huge slabs of ice and dealing the rust and decay of objects, but also discovering treasures like rolls of exposed film and, once, a caché of whisky.

The Lady Franklin Bay Expedition, at Ellesmere Island in 1881 (Photo: Library of Congress/Wikimedia)

The conditions that have kept historic polar and archaeological sites relatively intact, though, are quickly changing. At the 2014 International Polar Heritage Conference, the keynote address covered “climate changes and the vulnerability of our Arctic heritage.” In some places, for instance, newly melting permafrost is threatening the stability of historic buildings, and some sites that had always been frozen are now thawing out, which affects how their materials (wood, in particular) decay. One team of researchers looked at a midden at a 4,500-year-old settlement called Qajaa, in West Greenland, where some parts of the midden had started thawing every summer while some parts stayed frozen. “We found that the permafrozen wood was still extremely well preserved even after 4,000 years and resembled fresh wood,” says Henning Matthiesen, one of the researchers who worked on the study. The thawing wood, on the other hand, had lost 25 percent of its dry mass.

The speed at which thawing wood decays will vary, depending on the moisture in the area and the fungi that live there. But it’s not only danger these sites face from climate change, either. On the coasts of Canada and Greenland, permafrost melting, erosion and storm surges mean that some sites could simply disappear into the ocean.

In the past few years, some polar researchers have started using digital scanners to help preserve the sites. In Canada, a project based at the University of Calgary has used a 3D digital scanner to document the location and conditions of the buildings and artifacts at Fort Conger, at Ellesmere Island, which served as a base for Arctic exploration. For a host of reasons—the deterioration of the structures, erosion, vandalism, and the possible need for environmental remediation of pollution—the park responsible for the site wanted to document its current conditions. These digital scans are detailed enough that preservation teams were able to bring pre-made replacement boards to the site during the next season; they also provide a blueprint for restoration or, in a worst case scenario, reconstruction, should the site be further damaged or lost altogether.

The fact that any of these structures are still around is remarkable, though.  ”Mawson built the huts really not expecting them to survive,” says Jensen. And the point of preserving them is, in some ways, abstract—a point of pride for the countries who claim parts of these extreme regions, a hedge that future researchers will want access to physical evidence of this history. And while tourism is increasing, any place in Antarctica still very difficult to reach. “There are more people that have climbed Everest than have been inside Mawson’s huts,” Jensen says. “And that’ll be the case for some time.”