To see how deeply interconnected the planet truly is, look no further than the massive ice sheets on the Northern Hemisphere and South Pole.
To see how deeply interconnected the planet truly is, look no further than the massive ice sheets on the Northern Hemisphere and South Pole.
Thousands of miles apart, they are hardly next-door neighbors, but according to new research from a team of international scientists — led by Natalya Gomez, Ph.D. ’14, and including Harvard Professor Jerry X. Mitrovica — what happens in one region has a surprisingly direct and outsized effect on the other, in terms of ice expanding or melting.
The analysis, published in Nature, shows for the first time that changes in the Antarctic ice sheet were caused by the melting of ice sheets in the Northern Hemisphere. The influence was driven by sea-level changes caused by the melting ice in the north during the past 40,000 years. Understanding how this works can help climate scientists grasp future changes as global warming increases the melting of major ice sheets and ice caps, researchers said.
The study models how this seesaw effect works. Scientists found that when ice on the Northern Hemisphere stayed frozen during the last peak of the Ice Age, about 20,000 to 26,000 years ago, it led to reduced sea levels in Antarctica and growth of the ice sheet there. When the climate warmed after that peak, the ice sheets in the north started melting, causing sea levels in the southern hemisphere to rise. This rising ocean triggered the ice in Antarctica to retreat to about the size it is today over thousands of years, a relatively quick response in geologic time.
Read more at Harvard University
Image: An iceberg in the central Scotia Sea in 2019. (Credit: Thomas Ronge)
