Researchers from the University of Chicago have found that the world's largest ice sheets in Antarctica and Greenland are more stable than previously believed.
Ancient shorelines have been used for decades by scientists to predict the stability of some of the largest ice sheets in the world. Shoreline markings from millions of years ago were high, scientists predicted it to be because of rising sea levels due to the melting of ice sheets. Over the past few years, shoreline markings have reportedly been very high, leading scientists to believe that the world's biggest ice sheets in Antarctica and Greenland are melting rapidly.
However, a new research conducted by researchers from the University of Chicago found that these large ice sheets are actually more stable than previously believed. They used the east coast of the U.S. as their laboratory and found that the high shoreline markers were not because of rise in sea level but something else.
David Rowley, CIFAR Senior Fellow and professor at the University of Chicago, found that Earth's hot mantle pushed up segments of ancient shorelines over millions of years, making them appear higher now than they originally were millions of years ago.
"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," says Rowley. "Our study is telling scientists that they can no longer ignore the effect of Earth's interior dynamics when predicting historic sea levels and ice volumes."
For the study, the research team used computer simulations to follow the movement of mantle and tectonic plates that occurred over time. Their findings on how the ancient shoreline would have developed over millions of years matches what geologists mapping this ancient coast have observed.
"The paper is important because it shows that no prediction of ancient ice volumes can ever again ignore the Earth's interior dynamics," explains Rowley. "It also provides a novel bridge between two disciplines in Earth science that rarely intersect: mantle dynamics and long-term climate. It is the kind of study that changes how people think about our past climate and what our future holds."
The findings were published May 16 online in the journal Science. The research was a collaboration between CIFAR Senior Fellows Alessandro Forte (Université du Québec à Montréal) and Jerry Mitrovica (Harvard), and a former CIFAR-supported post-doctoral fellow Rob Moucha (Syracuse).
