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Melting glaciers reveal ancient bodies

In August 1999, three sheep hunters were hiking through Tatshenshini-Alsek Park in northern British Columbia when they came upon a surprise: A human body was poking out of the ice at the foot of a glacier. They had stumbled upon the well-preserved (though headless) 550- to 600-year-old body of a man. Alongside “Kwäday Dän Ts’ìnchí,” or “Long Ago Man Found” as he is called, were hunting tools, a hat, a fur robe and some food — a pouch of dried salmon — preserved in exquisite detail. Subsequent tests have revealed that the man likely lived near the coast in British Columbia but traveled inland, and was about 20 years old and healthy when he died. The cause of death was likely exposure in a blizzard. Buried for hundreds of years, his body was only revealed when it melted out of the glacier.

This scenario is becoming less and less rare, as warming temperatures continue to melt alpine glaciers and ice fields at a high rate. Bodies and artifacts have melted out of glaciers on at least three continents and the likelihood of discovering more — possibly on every inhabited continent — and older and older ones, grows with each passing year.

In Wrangell-St. Elias National Park in Alaska, a large, centuries-old pile of caribou dung melted out of the ice patch shown here. Researchers are using the caribou dung as one variable in a model to locate archaeologically significant spots that might be revealed by shrinking glaciers and ice patches. If caribou congregated at the site, it is possible that ancient humans went there too. Photo by Craig Lee, INSTAAR.


Glaciers around the world have been retreating since the end of the Little Ice Age around 1850, says Lonnie Thompson, a glaciologist at the Ohio State University in Columbus. Mountain glaciers lock up about 100,000 cubic kilometers of ice (as compared to Greenland and Antarctica, which comprise 32 million cubic kilometers of ice), and most mountain glaciers, including all tropical glaciers, are shrinking, Thompson says.

The rates of glacial change, however, vary regionally. In North America, average glacial cover has been reduced by at least 25 percent, though in Glacier National Park in Montana, two-thirds of the glaciers have disappeared in less than 100 years. In South America, where most of the world’s tropical glaciers lie, some High Andes glaciers have lost more than 50 percent in area and two-thirds in volume in the 1990s alone. In Africa and Asia, the majority of glaciers are thinning rapidly. On Kilimanjaro, glaciers that have persisted for more than 11,000 years have decreased in area by 60 to 70 percent and may be gone by 2020, Thompson says. Thus, studying glaciers and figuring out what they may be ready to reveal is a time-sensitive field of incredible importance, he says.

Indeed, “one benefit, if you can call it that,” of global warming, says Johan Reinhard, a high-altitude archaeologist and Explorer-in-Residence with the National Geographic Society, is that as glaciers retreat and expose land that has not been at the surface for thousands of years, more bodies and artifacts are likely to be found. And “an ancient frozen body has to be one of the most valuable things on Earth,” says Reinhard, who discovered the Inca Ice Maiden in the Andes in 1995 and has since been back to the Andes to search for well-preserved clues to Incan life.

The kind of information that can be retrieved from a frozen mummy is irreplaceable and neverending, especially as forensic technology keeps improving, Reinhard says. If recovered soon after it melts out of a glacier, the preservation of a body is so good that a variety of different analyses can be done, including DNA, radiometric dating and isotopic analyses, such as were done on Kwäday Dän Ts’ìnchí. They can even test blood for antibodies to see what diseases these ancient humans may have encountered, Reinhard says, and check stomach contents to see what they ate.

“Freezing may be the most ideal condition under which prehistoric organic remains can be preserved,” wrote James Dixon, an anthropologist at the Colorado Institute of Arctic and Alpine Research, and colleagues in the January issue of American Antiquity. Usually, clothing, tools and other organic materials decompose quickly after deposition, but freezing can nearly perfectly preserve these items for thousands of years, Dixon says.

It is possible, some archaeologists say, to predict where to find archaeological sites preserved in glaciers, as certain locations have revealed more artifacts than others. For example, near the site where Kwäday Dän Ts’ìnchí was found and throughout British Columbia and the Yukon Territory, archaeologists have found about 180 ancient artifacts, including hunting darts and arrows, some of which have dated to more than 9,500 years old, in alpine glaciers and ice fields since 1997, says Greg Hare, an archaeologist with the Yukon government.

And in Europe, four bodies have melted out of glaciers in the same vicinity in the Italian Alps. In perhaps the most well-known glacial find, German hikers found Ötzi (the “Iceman”), a 5,300-year-old body, poking out of an alpine glacier in 1991 (see Geotimes, February 2004). And last August, an amateur historian found the frozen, preserved bodies of three World War I Austro-Hungarian soldiers melting out of a glacier on San Matteo Peak, the site of an important battle between the Italians and Austro-Hungarians.

Natives in North America and Europe had known trails through alpine glaciers in mountain passes, and in the High Andes of South America, ancient civilizations used mountain summits and glaciers as burial and sacrificial grounds, Reinhard says, making these good places to start to look for archaeologically significant finds. But “right now, it really is serendipity that you happen to be in the right place at the right time” to find a body or artifact, Thompson says. Thus, Dixon adds, “we need to focus our energy on the few [places] that might.”

So Dixon and colleagues William Manley and Craig Lee created a systematic approach that combines a variety of biologic (such as caribou ranges), geologic (such as the extent of glacial movement), and socio-cultural (such as transportation routes and historical information) datasets with satellite imagery and GIS software to spatially evaluate the relative archaeological potential of sites. Developing and testing their model, called MAPIS (Modeling Archaeological Potential of Ice and Snow), in Wrangell-St. Elias National Park and Preserve in Alaska, the most glaciated area in the United States, the scientists pinpointed potential sites for archaeological finds. On two subsequent field surveys during summer melts, the team found 14 sites with artifacts ranging in age from 170 to 2,880 years old.

This system worked well in the park, Dixon says, and the researchers hope next to look at another site in Alaska using the same model. While MAPIS is specific to the region in which Dixon’s team worked, it could certainly be transferred to other locations, he says, with the caveat that the model is not a formula that can simply be applied. Geoarchaeologists need first to figure out the cultural, geologic and biologic variables and components specific to the region in which they are working.

Even with satellite data, models and increasing glacial melt, however, it is going to remain difficult to find anything, says Wolfgang Müller, a geochemist at Royal Holoway University of London who has done extensive work on Ötzi. “Retreating glaciers will not reveal too many new well-preserved bodies similar to the Iceman, because it simply requires too many chance events to happen all at once,” he says — chance events such as just the right glacial dynamics (not carrying a body downstream and depositing it quickly), instant burial by a large snowstorm and no scavenging by animals.

Even if all these factors combine to preserve a body, challenges remain to actually recovering one, even in a spot known to be archaeologically significant, Dixon says, such as figuring out the timing of when an artifact or body might melt out of a glacier or ice patch, and being there to recover it. Such research is interdisciplinary, he says, involving glacial dynamics, archaeology, biology, anthropology, history and remote sensing.

Procuring funding is also not easy, Reinhard says. For the most part, organizations don’t want to fund a “going out to search for something that might not be there” kind of research project, he says. “So we need to get people to understand the incredible value” of these finds, and quickly, because “once these things are gone, they’re gone forever.”

Megan Sever

Link:
"Iceman's origins," in the feature "Geoarchaeology: The Past Comes to Light," Geotimes, February 2004

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