Glaciers are melting faster than ever, and while that might spell disaster for the planet, it has opened up a new field of research called glacial archaeology. Artifacts, bodies, and viruses frozen deep in ice for millions of years are now thawing out and washing to the surface; the warmer climate is also allowing archaeologists to navigate areas that were once too dangerous to excavate.
About 10 percent of the world is currently covered in glacial ice. The substance acts as a time machine, preserving the state of trapped objects as they were when they first frosted over. Glacial archaeologists do not have to worry about buried objects decaying, which makes them a great record of the past. Some of the most productive sites include Norway, Yellowstone National Park, and Siberia.
The 1991 discovery of Ötzi—a prehistoric human who is estimated to have lived in the 4th millennium BCE—in a melting glacier in the Italian Alps currently remains the greatest discovery for glacial archaeology. But it’s not the only noteworthy find we’ve seen in the last two decades.
Treasure trove of arrows
Earlier in September, Pilø and his team were searching through the Jotunheimen mountains in eastern Norway and uncovered a wooden arrow with a quartzite arrowhead and three feathers. Ancient people used feathers to stabilize the arrow and guide it to its target. These accents usually decay over time, but the ice kept them intact. The arrow is estimated to be 3,000 years old and may have belonged to a reindeer hunter from the early Bronze Age. It’s one of several arrows that have been surfaced from Norway’s melting ice in recent years.
Pilø says the favorite artifact he’s found was a 1,400-year-old wooden arrow with a blunt end. At close to 10 inches, it’s very small, which Pilø thinks would not have inflicted any kind of damage if shot. Further analysis revealed it to be a toy arrow, likely used by a child trying to master archery—and suggests the emphasis on hunting in this time period. “We can imagine the arrow got lost in the snow, and the child was very unhappy thinking he lost the toy forever, when actually, 1,400 years later, it melted out and we found it,” Pilø adds.
In 2014, Pilø and his colleagues uncovered a prehistoric ski in a melting ice patch in Norway. The ski is thought to be 1,300 years old, and had the bindings still intact. In 2021, they came across the second ski, making it one of the most well-preserved prehistoric skis to date. Because the skis were very well-preserved, Pilø says they were able to make replicas and race down slopes with iron-age skis. “That was a lot of fun.”
In August 2010, a partially preserved carcass of a baby wooly mammoth was found in Siberia’s permafrost. Nicknamed Yuka, the frozen animal is estimated to be around 30,000 years old, which puts it back in the last ice age. Based on where the specimen was discovered, it’s likely that the mammoth wandered away from its herd in the grasslands and got stuck in mud. Given that the lower body was well-preserved in ice, it gave researchers an opportunity to analyze the extinct species in-depth and extract its frozen blood.
The melting snow in Antarctica has also led to some interesting evolutionary findings. During a 2016 research expedition, Steven Emslie uncovered the preserved remains of 800-year-old Adelie penguins, along with some less well-preserved remains of the aquatic birds estimated to be around 5,000 years old. According to a study he published in 2020, the penguins were likely moving because of changing sea-ice conditions and were covered up by increasing snowfall, which prevented their remains from decaying.
Melting ice patches have also helped archaeologists identify objects belonging to the ancestors of early Native Americans around the northern US. Unlike glaciers, ice patches are smaller and move more slowly, making them better at preserving historical objects, explains Craig Lee, an environmental archaeologist at Montana State University who has conducted fieldwork on ice patches in Yellowstone and Alaska. He and others in the field have located all sorts of historical materials in these hotspots, from ancient arrow shafts and spears to well-preserved remains of ancient animals.
Lee and his collaborators have also been able to identify organic materials like wood, textiles, and flake-stone tools in the artifacts they’ve retrieved. “It’s very unusual for us to get access to ancient organic materials because they’re much more subjected to the natural processes of decay,” Lee explains. “Ice patches provide this uniquely preservative environment.” One example is a birch-bark basket found in a shrinking ice patch in Alaska in 2012, estimated to be around 650 years old.
A muddy future
While the warming climate is paving the way to more discoveries of the ancient past, there are some hiccups. Ross MacPhee, a paleontologist at the American Museum of Natural History, says that though it’s easier to access places that were once inhospitable, melting snow can be a poor substrate for research. “Everything is a mudhole,” which makes it much more complicated to look for fossils, he explains.
There is also the issue of ancient artifacts washing away: Pilø estimates 60 to 80 percent of mountain ice in Norway is in danger of melting by the end of this century. He describes it as a race against time. “If we are not ready to search for these finds, they will get lost, and so will the stories they could have told us.”
A combination of resources from aerial photography of mountains, digital models of terrain, and satellite imagery has helped glacial archaeologists melting glaciers and any areas where artifacts may have thawed out. However, their efforts can only go so far as ice around the poles continues to melt at unprecedented speeds. If temperatures continue to rise—July 2023, for example, was the hottest month ever recorded in human history—Pilø warns that 90 percent of mountain ice in Norway might disappear by 2100.
Still, archaeologists like Pilø are taking advantage of this fleeting opportunity to dig through the soft ice while they can. While the chances are tiny, he still holds out hope that the melting glaciers will help him find the next ice mummy.