Insitu Break-up Melting in place. Lake Ice Ice formed on a lake, regardless of observed location. Lead Long, narrow opening in the ice. Polynya Any non-linear shaped opening enclosed by ice. Puddle An accumulation of melt water on ice, mainly due to melting snow but in the more advanced stages also to the melting of ice.
Initial stage consists of patches of melted snow.
Rafted Ice Type of deformed ice formed by one piece of ice overriding another. Rafting Pressure processes whereby one piece of ice overrides another. Most common in new ice. Ridge A line or wall of broken ice forced up by pressure. May be fresh or weathered.