Scientists have long used ancient shorelines to predict the stability of today's largest ice sheets in Greenland and Antarctica believing, for example, that markings of a high shoreline from 3,000,000 years ago during a warm period on Earth were evidence of a high sea level due to ice sheet collapse at the time.

This assumption has, in turn, led many to hypothesize that if the world's largest ice sheets collapsed before, the same could very well happen again as the Earth continues to warm again.

More than ever, however, this theory is at risk of disintegrating under the weight of new evidence put forth in a study led by David Rowley, a professor at the University of Chicago, who believes he has found evidence that the markings are in fact the result of Earth's hot mantle pushing up segments of ancient shorelines over millions of years.

Such a phenomenon, Rowley and his colleagues point out, would make the shorelines appear higher now than they originally were millions of years ago.

In particular, the group studied the coast from Virginia to Florida using computer simulations to follow the movement of the mantle and tectonic plates that occurred over time. 

"Our findings suggest that the previous connections scientists made between ancient shoreline height and ice volumes are erroneous and that perhaps our ice sheets were more stable in the past than we originally thought," Rowley said in a press release. "Our study is telling scientists that they can no longer ignore the Earth's interior dynamics when predicting historic sea levels and ice volumes."

Going forward, the team hopes to try to make accurate predictions in other locations in the world.