Ancient changes along the Hudson offer glimpse into how ice sheets grew
In a kind of geological mystery, scientists have known for decades that a massive ice sheet stretched to cover most of Canada and much of the northeastern U.S. 25,000 years ago. What’s been trickier to pin down is how — and especially how quickly — it reached its ultimate size. One clue to answering that, Tamara Pico said, may involve changes to the Hudson River. Pico, who is a Graduate School of Arts and Sciences Ph.D. student working in the group led by Jerry Mitrovica, the Frank B. Baird Jr. Professor of Science, is the lead author of a study that estimates how glaciers moved by examining how the weight of the ice sheet altered topography and led to changes in the river’s course. The study is described in a July paper published in Geology. “The Hudson River has changed course multiple times over the last million years,” Pico said. “The last time...