Rewriting forgotten ice core fossils from Greenland’s frozen past
The secret military plan never happened; engineers quickly learned how quickly and unpredictably the ice could change, making the site highly unstable and completely unsuitable for nuclear weapons. Colgan, project manager Camp Century Climate Monitoring ProgramHe is one of the few people on the site of the former Army facility, which is now buried under more than 100 meters of accumulated snow and ice. “The tunnels have collapsed and are compressed,” he says. “The snow has turned to ice with the crepe debris.”
Camp Century was abandoned in 1967, a year after the engineers achieved their true scientific feat: drilling the first ice cores. Along with new nuclei from other parts of Antarctica and Greenland, these thin ice cylinders have provided researchers with a crucial record of ancient climatic conditions since then, both to understand the past and to shape our future. Colgan says Camp Century has been invaluable to science now more than ever.
“Camp Century was the first ice core program, and we’re still learning,” says Colgan, adding that the Cold War-era team probably realized that the site was not suitable as a missile base for their work very early on, but insisted on the name of science . The subglacial sample, he says, “is only there because they wouldn’t take the answer. They put traces in the base and even then they went on.”
A mile-long Camp Century ice cores were previously studied. After being collected in 1966, however, a sample of the ice core — the frozen mud beneath the ice and the base about 12 feet long — was stored in an Army laboratory freezer, then at the University at Buffalo. The sample was eventually sent to Denmark, where it was interrupted again, in the ice core archive at the University of Copenhagen.
In 2017, while staff were preparing to renovate the facility, someone saw boxes of samples from an unopened Camp Century hill. Inside, rather than the thin cylinders that are common in ice cores, they found glass vessels and frozen sediments in glacial rocks. Almost immediately, the discovery became a sensation on the field. It would be prohibitively expensive to obtain a peer-to-peer sample using modern drilling technology today.
“We knew how important those samples would be. We all started to shake and support a little bit, “says Schaefer. As the news spread, Paul Bierman went to Copenhagen with a geologist at the University of Vermont to negotiate some of the material.” We tried not to see how excited we were. We tried to keep it together. “.
Beneath the layer of ice, the drill collects sediment and subglacial material collected from the place where the rock hit the base. The exposed rock, like everything else on the Earth’s surface, is bombarded with cosmic rays, creating chemical signatures, called cosmogenic nuclides, that can be used to determine whether an area is ice-free. “Nucleids are formed only if the rock sees the open sky,” says Schaefer. Colgan says the work of dating the material is “really, really hard,” but the Camp Century sample was initially dated with confidence, dating back less than a million years, in line with a sample from central Greenland.
Christ, Schaefer, and their colleagues continue to study Camp Century material to reduce its age range and learn more about the plant material it preserves, which is unique in that massive ice deposits typically destroy organic material. The next phase of the research, already underway, is to look for DNA traces that could be used to determine existing species and rebuild the entire ecosystem. So far it is similar to the modern Arctic tundra.
There is still the core of Camp Century to explore. The lower layers of the sample contain sediments up to 3 million years old, says Christ, and may contain more organic matter, which may be “the oldest material ever recovered from under ice.”
Camp Century was never going to take up nuclear weapons, but it is proving to be far more significant than its planners imagined.
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