Researchers at the University of Colorado at Boulder are working to pinpoint rapidly melting glaciers and ice fields they believe may hold human artifacts and other organic materials, which could revolutionize anthropological theories and provide invaluable clues to human migration, colonization and adaptation dating back thousands of years.
As global warming continues to melt glaciers and ice fields at an unprecedented rate, increasingly older and significant artifacts--as well as plant material, animal carcasses and ancient feces--are being released from ice that has gripped them for thousands of years, according to James Dixon, curator of the Museum and Field Studies program at the CU Museum and a fellow at INSTAAR.
"There is a certain urgency to this because a lot of these artifacts are melting out now," Dixon said. "And once exposed, they decompose or are destroyed quickly."
Once seen as archaeological wastelands, some glaciers and ice fields are beginning to be recognized as areas rich in artifacts.
Dixon and INSTAAR Research Scientist William Manley have spent the past three years developing and testing a Geographic Information System model, or GIS, to identify glaciers and ice fields in Alaska that are likely to hold artifacts. To do this, they pulled together independent data sets and layered them to produce maps with the hope of defining the most promising areas.
The independent sets detail cultural, biological and physical data from a number of sources. For example, the researchers sought ice fields that may have been used by prehistoric hunters to kill animals seeking refuge from insect swarms in the summer, or glaciers that may have provided them a pass over a mountain range. By overlaying these maps with the known historic ranges of animals and ice patches, they have identified specific sites where artifact "hot spots" might be located.
"The final maps show us where we can expect to find archaeological remains on glaciers," Manley said.
"Based on what we understand about glacier flow, we can expect to find concentrations of remains in certain places and of a certain age," he said.
During summer 2001, Dixon and Manley put their model to the test in the Wrangell-St. Elias National Park and Preserve in southeast Alaska. Despite poor conditions due to heavy winter snows and cool summer conditions that didn't allow for a lot of snowmelt, they were able to identify 32 sites at which archaeological and paleontological specimens were found.
Among the items found was a well-preserved antler projectile point that may have punctured a large mammal scapula found at the same site. They also found several perfectly preserved rodent carcasses, as well as horseshoe nails and horse hoof rinds left behind when someone shod a horse, probably during the gold rush at the turn of the last century, according to Dixon.
Quick retrieval of these artifacts is necessary to save them, because rodents and other scavengers often find and dispose of animal carcasses that may be hundreds or even thousands of years old, and they are quick to gnaw on bones that are released from the ice, he said. Articles of clothing and other organic materials, once thawed and exposed to the elements, also decompose quickly.
"People may find these artifacts and not have any idea what they are, or how old they are," Dixon said.
An estimated 10 percent of the Earth's land surface is covered with perennial snow, glaciers and ice fields, providing plenty of opportunities for exploration. The organic remains locked within these unique and significant environments remain virtually unknown and unexplored by archaeologists and other scientists, Dixon said. And once they melt out of the ice, if they aren't found, they will be lost forever.
Dixon and Manley's research was cited in an April 19 article in the journal Science and in a recent address by National Science Foundation Director Rita Colwell at the Arctic Forum in May. The National Science Foundation funded the research.