Glacier Types: Piedmont

The massive lobe of Malaspina Glacier in Alaska is clearly visible in this photograph taken from a Space Shuttle flight in 1989. Agassiz Glacier is the smaller glacier to the left. The Malaspina Glacier is one of the most famous examples of this type of glacier, and is the largest piedmont glacier in the world. Spilling out of the Seward Ice Field (visibile near the top of the photograph, Malaspina Glacier covers over 5,000 square kilometers as it spreads across the coastal plain.

Glacier of the ice cap on byam Martin Mountains. Sitauted near Navy Board Inlet, which divides Baffin and Bylot Islands, this glacier has an expanded foot, characteristic of a piedmont glacier, where it widens onto a lowland. The 3-km wide terminus shows several medial moraines which are the combination of lateral moraines from adjacent tributary glaciers. —Source: Natural Resources Canada. Copyright Terrain Sciences Division, Geological Survey of Canada.

Marginal features of a piedmont glacier. This piedmont glacier expanding onto a lowland shows various sedimentary features. The dark lines along the glacier are medial moraines, the merged lateral moraines of tributary glaciers. The dark lines arcing parallel to the margin are debris-rich ice layers which have been sheared up from the base of the glacier. The intersecting sharp-crested ridges in front of the ice margin are crevasse fillings, ridges of till or gravel deposited in cracks in the ice. The ridge which borders the ice to the left, especially upstream, is a moraine pushed up when the glacier was thicker and more extensive during the Neoglacial advance a few centuries ago.—Source: Natural Resources Canada. Photograph by Ron DiLabio. Copyright Terrain Sciences Division, Geological Survey of Canada.

Piedmont glacier, west of Lake Hazen, Ellesmere Island. An outlet glacier from a montane ice cap has expanded its snout onto the adjacent lowlands to form a nearly circular mass.—Source: Natural Resources Canada. Photograph by Douglas Hodgson. Copyright Terrain Sciences Division, Geological Survey of Canada.