A team of researchers from Columbia University's Lamont-Doherty Earth Observatory and the University of Oregon used changes in the Hudson River over thousands of years to develop a new model for how glaciers grew during the last ice age. The study, published in the journal Nature Communications, found that changes in the river's flow and sediment load played a key role in determining the size and shape of glaciers.

The researchers studied sediment cores from the Hudson River estuary, which contains a record of the river's flow and sediment load over the past 20,000 years. They found that during periods when the river's flow was high and its sediment load was low, glaciers were larger. This is because the increased flow of water helped to transport sediment away from the glaciers, which reduced the amount of melting that occurred.

Conversely, during periods when the river's flow was low and its sediment load was high, glaciers were smaller. This is because the reduced flow of water allowed sediment to accumulate near the glaciers, which increased the amount of melting that occurred.

The researchers' model suggests that changes in the Hudson River's flow and sediment load were a key factor in determining the size and shape of glaciers during the last ice age. This information could help scientists to better understand how glaciers will respond to future climate change.

"Our study provides a new way to understand how glaciers grew during the last ice age," said lead author Jessica Badgeley, a postdoctoral research scientist at Lamont-Doherty. "This information could help us to better predict how glaciers will respond to future climate change."

The study was funded by the National Science Foundation.