The melting of polar ice is not only shifting the levels of our oceans, it is changing the planet Earth itself. Newly minted Ph.D. Sophie Coulson and her colleagues explained in a recent paper in Geophysical Research Letters that as glacial ice from Greenland, Antarctica and the Arctic Islands melts, Earth's crust beneath these land masses warps, an impact that can be measured hundreds and perhaps thousands of miles away. "Scientists have done a lot of work directly beneath ice sheets and glaciers," said Coulson, who did her work in the Department of Earth and Planetary Sciences and received her doctorate in May from the Graduate School of Arts and Sciences. "So they knew that it would define the region where the glaciers are, but they hadn't realized that it was global in scale." By analyzing satellite data on melt from 2003 to 2018 and studying changes in Earth's crust, Coulson and her colleagues were able to measure the shifting of the crust horizontally. Their research, which was highlighted in Nature, found that in some places the crust was moving more horizontally than it was lifting. In addition to the surprising extent of its reach, the Nature brief pointed out, this research provides a potentially new way to monitor modern ice mass changes. - Phys.Org