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. A graduate student working in the group led by Jerry Mitrovica, the Frank B. Baird Jr. Professor of Science, Pico 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 was about 30,000 years ago, just before the...