Situated in Southeast Alaska is the 13.6 mile-long Mendenhall Glacier which is one of the most scenic places in the state. The glacier is also home to various ice caves where an ancient forest was revealed in the last decade, due to the melting ice.
Ultimately, glaciers are a high amount of accumulated snow, which has compacted into ice. Unfortunately, these slowly moving rivers of ice have been retreating in Alaska as a result of the warming climate in Southeast Alaska and Mendenhall Glacier is also a victim of this process. It has retreated 1.75 miles since 1929 and will do so in the foreseeable future as well.
As Mendenhall Glacier is shrinking and retreating, the remains of an ancient forest have been revealed from under the melting ice. The preserved stumps and trunks are now exposed for the first time in over 1000 years.
Some trees that popped up still have intact roots in the ground, even bearing a bit of bark. Based on the diameter of the trunks and the trees growing in the region today, a team of researchers has identified the trees as either spruce or hemlock.
“There are a lot of them, and being in a growth position is exciting because we can see the outermost part of the tree and count back to see how old the tree was,” Cathy Connor, a geology professor at the University of Alaska Southeast who was involved in studying the trees stumps, told LiveScience. “Mostly, people find chunks of wood helter-skelter, but to see these intact upright is kind of cool.”
The Earth has gone through a series of ice ages, in which glaciers and ice sheets grew, advanced, and then retreated. During these events, they often discharge molten ice streams that push aprons of gravel beyond the edge of glaciers.
A layer of gravel, about 4 to 5 feet (1.2 to 1.5 meters) high, likely engulfed the forest, before the glacier finally advanced enough to plow over the trees, snapping off limbs and encasing the stumps in an ice tomb.
The Mendenhall Glacier in Alaska has been experiencing significant retreat, with an average loss of about 170 feet per year since 2005. Recent unusually warm summer temperatures are expected to accelerate the Mendenhall Glacier’s retreat even further. This rapid glacial decline is causing concern among local communities, who worry about rising sea levels and the potential loss of crucial freshwater sources.
The retreat of glaciers, while alarming, has unexpectedly provided scientists with a unique opportunity to study well-preserved remnants of ancient ecosystems. Researchers plan to return to the Mendenhall Glacier site to examine sediment and vegetation, including pine needles from the recently exposed trees. By analyzing growth bands in these trees, they hope to determine their age at the time of death and gain insights into the area’s past climate and environmental conditions.