Scientists find evidence of ancient tundra landscape frozen for nearly 3 million years, which indicates the Greeenland ice sheet could persist much longer than previously thought, according an international study published Friday.

The study, which involved researchers from University of Glasgow in UK and several American universities, offers key insights into climate change patterns.

This international team found organic soil frozen to the bottom of the Greenland Ice Sheet for 2.7 million years, this provides a strong evidence that the ice sheet has endured many periods of past global warming.

Glaciers have been thought to be like sanding machines, scraping off everything from vegetation, soil and even the top layer of bedrock as they move over the land. The scientists were therefore very surprised to discover an ancient tundra landscape preserved under two miles of ice.

Co-author of the paper, Dr Dylan Rood of the University of Glasgow said: "The ancient soil under the Greenland Ice Sheet helps to unravel an important mystery surrounding climate change - how did big ice sheets melt and grow in response to changes in temperature?"

According to researchers, the new discovery indicates that even during the warmest period since the ice sheet formed, the center of Greenland remained stable. This allowed a tundra landscape to be locked away under ice, unmodified, through millions of years of global warming and cooling.