High Quality Content by WIKIPEDIA articles! 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.