Ice Scour

Ice Scour

When floating ice features (typically an iceberg or sea ice) drift into shallower waters, their keel may come into contact with the seabed. As they keep drifting, they produce long, narrow furrows most often called gouges, or scours (Wadhams 2000, p. 72, Weeks 2010, ch. 13). This phenomenon is common in offshore environments where ice is known to exist. Although it also occurs in rivers and lakes (Noble and Comfort 1982, Grass 1984), this phenomenon appears to be better documented from oceans and sea expanses.

Gouges produced via this mechanism should not be confused with strudel scours. These results from spring run-off water flowing onto the surface of a given sea ice expanse, which eventually drains away through cracks, seal breathing holes, etc. When that happens at shallow water depths, the resulting turbulence generates a depression into the seafloor (Abdalla et al. 2008, Fig. 5). Seabed scouring by ice should also be distinguished from another scouring mechanism: the erosion of the sediments around a structure due to water currents, a well known issue in ocean engineering and river hydraulics (e.g. Annandale 2006) – see bridge scour.