Glaciers usually scrape away any soil or even bedrock beneath them; researchers were shocked to discover a "tundra landscape" hidden beneath two miles of ice from the Greenland Ice Sheet.
"We found organic soil that has been frozen to the bottom of the ice sheet for 2.7 million years," University of Vermont geologist Paul Bierman said in a University of Vermont news release.
The Greeenland Ice Sheet is as large as Alaska, and provides a wealth of insight into climate change and rising sea levels.
"The ancient soil under the Greenland ice sheet helps to unravel an important mystery surrounding climate change," Dylan Rood a co-author on the new study from the Scottish Universities Environmental Research Centre and the University of California, said in the news release. "How did big ice sheets melt and grow in response to changes in temperature?"
Millions of years' worth of global warming and cooling could have allowed the tundra to stay stable as it was engulfed in ice. The ice sheet's center has acted as a "refrigerator" preserving the ancient landscape as opposed to a method of erosion.
To make their findings the researchers examined 17 "dirty ice" samples from the ancient ice cores.
"Over twenty years, only a few people had looked hard at the sediments from the bottom of the core," Bierman said.
The team found an element called beryllium in the frozen sediments, this element usually falls from the sky and sticks to rocks and soil. The beryllium isotope was found in surprisingly high concentrations considering the sediment had not been exposed to the sky in so long.
"So we thought we were going looking for a needle in haystack," Bierman said. "It turned out that we found an elephant in a haystack."
This concentration of beryllium is usually only found in soils that have been developing over millennia.
The finding indicates the "soil had been stable and exposed at the surface for somewhere between 200,000 and one million years before being covered by ice," Ben Crosby, a member of the research team from Idaho State University said in the news release.
The presence of organic compounds, such as remnants of nitrogen and carbon, suggest the region was once a wooded area.
"Greenland really was green! However, it was millions of years ago," Roodsaid. "Greenland looked like the green Alaskan tundra, before it was covered by the second largest body of ice on Earth."