Loading ...tropical storms, but this 7-minute video is an informative primer on near-surface geomorphology and melting of ground ice. This erosive process has been documented to be quite significant on Pelly Island on the seaward edge of the Mackenzie River delta, where coastal retreat as a result of melting of ground ice has been recorded as high as 40 meters per year on some parts of this island facing the Beaufort Sea. Caution is recommended for location and placement of human-made structures on the vegetated capping of near-surface soil.