The recession of the Mendenhall Glacier, located in Mendenhall Valley, about 12 miles from downtown Juneau, has revealed the remains of the forest, the Juneau Empire reported. Tree stumps and logs litter the field along the west side of the glacier, with some of the bits of wood rubbed smooth, some with their bark still attached.
University of Alaska Southeast professor of geology and environmental science program coordinator Cathy Conner said she's been tracking the emergence of the forest and said the trees would have snapped as the glacier advanced. The stumps were then buried and protected under gravel.
She said some of the stumps were as old as 2,350 years old, while other dated between 1,200 to 1,400, and 1,870 to 2,000 years old.
“We’re seeing the Mendenhall wax and wane through time a little bit,” she said.
Conner said she hoped to find a pocket of sediment below the ice to find even older preserved forests, but the rock around the glacier is hard with fewer layers of sediment.
“The tricky part is, as the ice advances in earlier time, it tends to scour away whatever was there before,” she said. “So often you just get the latest chapter of the story, rather than come in at the introduction … It’s the luck of the Irish how you get a little bit of the story still remaining that hasn’t gotten ravaged and sent down the Mendenhall (River) and out to Gastineau Channel. Most of the story is now in the sea sediments and a little hard to decipher.”