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.

Magical ice cave at Mendenhall Glacier. Image credit: adam_gulkis

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 2000 years.

Mendenhall Glacier in all of its might. Image credit: blmiers2

Some trees that popped up still have intact roots in the ground, even bearing a bit of bark. And the trees being in a growth position, it’s possible to determine how old they are. 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.

The cave is full of pebble stones and gravel which buried the forest a long time ago. Image credit: AER Wilmington DE

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 likely engulfed the forest, encasing the trees in a protective tomb of gravel.

The entrance of an ice cave at Mendenhall Glacier. Image credit: Gillfoto

The retreat and melting of glaciers are a cause for alarm. At the same time, these ancient trees give us the opportunity to learn about the climate of the past.