Moutonnée Lake

Moutonnée Lake is a second epi-shelf lake formed where George VI Ice Shelf impinges on Alexander Island. Unlike Ablation Lake it does not have a floating tongue extending into it; rather it has a combination of a moraine-covered rock bar and an ice cliff across its mouth. There are several exposures of striated bedrock in this valley, in addition to some rather poorly developed roches moutonnées.

Moutonnée Lake
Overview of frozen Moutonnée Lake showing George VI Ice Shelf with its cliff and the moraine-covered rock bar to the left, and the distant mountains of Palmer Land in the background. In the middle distance, the flat area was once used as an airstrip for landing field parties, but has since been abandoned because of potential soft ground.
Moutonnée Lake
View from a high-level terrace, looking south along the moraine-covered rock bar with Moutonnée Lake on the right and George VI Ice Shelf on the left.
Moutonnée Lake
The head of Moutonnée Valley, showing small cirque glaciers beginning to emerge from the extensive winter snow cover.
Moutonnée Lake
Two small un-named cirque glaciers at the head of Moutonnée Valley. Glacial debris mantles the valley floor.
Moutonnée Lake
Melt-pool developing at the margin of Moutonnée Lake, adjacent to the rock bar.
Moutonnée Lake
Fifteen metre-high ice cliff of George VI Ice Shelf as it enters Moutonnée Lake. It is likely that the ice is mainly grounded at this point. Note the small ridge of lake ice pushed up in front of the cliff.
Moutonnée Lake
Striated basalt bedrock surface in the rock bar adjacent to Moutonnée Lake. Ice flow to the east indicates that they were created by expanded glaciers in Moutonnée Valley, rather than by the ice shelf.
Moutonnée Lake
Diamicton (poorly sorted sediment interpreted as basal till) in the upper part of Moutonnée Valley. This contains Palmer Land erratics, and therefore was deposited by an expanded George VI Ice Shelf, following the creation of striated surfaces by local glaciers.
Photos Michael Hambrey, November and December 2012.