Study: Ice Melting Can Warp Earth's Crust
A new study has found that ice melting can warp Earth’s crust horizontally more than 1,000 kilometers away from the glacier.
The study, conducted at Harvard University, paired satellite data of ice loss with a model showing how changes in mass (from ice sheets, glaciers, and ice caps) impact the planet’s outermost shell. It found that from 2003 to 2018, much of the Northern hemisphere shifted horizontally due to melting ice in Greenland and the Arctic. Canada and the U.S. shifted up to 0.3 mm per year.
As ice melts around the world, Earth’s topography is changing. Heavy glaciers compress the ground underneath them and cause ‘forebulges’: areas of Earth’s crust surrounding the glacier that rise up. As the ice melts and gets lighter, the crust and upper mantle shift and rise underneath the glacier, and the forebulges sink.
While the vertical changes in the crust are well known, this study is one of the first to look at horizontal shifts. It found that, even far from melting ice, the horizontal movement was greater than the vertical in some areas.