Top secret Cold War project yielded plants that once thrived under miles of Greenland ice

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A long-lost earth core drilled from miles of ice in northwestern Greenland in the 1960s has shown that it was once home to an overgrown landscape in the last 1 million years – and perhaps as many as 400,000 years ago. .

Scientists had expected to find sand and stone in the dirt, but were instead surprised to see twigs and leaves.

“We found frozen parts of plants – twigs, leaves and mosses – that resemble the Arctic tundra found in the few ice-free areas of Greenland today. The biggest difference between then and now is that the miles of ice that must have melted this part of Greenland” , said Andrew Christ, a postdoctoral fellow at Gund and a lecturer in geology at the Gund Institute for Environment at the University of Vermont.

“The landscape was probably dotted with small ponds and streams, while tundra plants covered the landscape.”

The discovery is more evidence of a new and disturbing understanding that the Greenland ice sheet completely melted away during a recent warm period in Earth’s history – periods not much different from those we are in today – and accelerated by the man-made global warming.
“Over the last million years, Earth’s climate was interrupted by relatively short warm periods of about 10,000 years, called interglacials, when there was less ice on the poles and the sea level was higher. We think it is possible that one of those interglacials “possibly about 1 million years ago or 400,000 years ago, was the last time this part of Greenland melted and tundra grew on the landscape,” said Christ, lead author of the study published Monday in the journal PNAS.
Shown is a winding river in Greenland.

Project ice worm

The material analyzed in the study has a unique and intriguing story. It came from Camp Century, a Cold War military base dug into the ice sheet far above the Arctic Circle in the 1960s.

It was called Project Iceworm and its true mission was to hide 600 nuclear missiles under the ice near the Soviet Union.

As a cover, the military presented the camp as a polar science station. The military mission failed, and the cores of ice and dirt they had collected were moved from one place to another in cookie jars. The samples spent a period at the University at Buffalo in upstate New York in the 1970s before being moved to another freezer in Copenhagen, Denmark in the 1990s. That’s where the cores sat for decades until they were moved to a new freezer and accidentally rediscovered in 2017.

The latest dating techniques allowed scientists to analyze the sediment and the perfectly preserved plant fossils. The research team dated within the past million years.

Engineers at the Cold Regions Research and Engineering Laboratory conquer an ice core at Camp Century, Greenland, c. 1966.

“We used two different techniques. First, we used cleanroom chemistry and a particle accelerator to count atoms that form in rocks and sediment when exposed to natural radiation that bombardes Earth. Then a colleague used an ultra-sensitive method to detect the emitted light. measuring grains of sand to determine when they were last exposed to sunlight. Both methods tell us how long the ancient soil has been buried under ice, ”Christ explained via email.

Merging what happened last time Greenland was warmer than the present is critical as the ice sheet is believed to contain up to 7 meters (23 feet) of sea level rise – a shift in sea level that could inundate many major cities around the world.

“In the geologic past, it would have taken thousands of years for the ice sheet to melt. We are rapidly warming the climate at a rate higher than anything observed in the last million years.

“That is a concern for the melting of the Greenland ice sheet and the sea level raising significantly during our lifetime and especially in the lives of our grandchildren.”

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