
.topic 50
Submerged ice attached or anchored to the bottom, irrespective of the nature of its formation

.topic 60
Submerged ice attached or anchored to the bottom, irrespective of the nature of its formation

.topic 80
An area of freely navigable water in which ice of land origin is present in concentrations less than 1/10. There may be sea ice present, altough the total concentration of all ice shall not exceed 1/10


.topic 90
Accumulations of floating ice made up of fragments not more than 2 m across, the wreckage of other forms of ice.


.topic 100
From the point of view of the submariner, a downward projection from the underside of the ice canopy; the counterpart of a hummock.


.topic 110
The ratio expressed in tenths or oktas describing the mean areal density of ice in a given area.


.topic 120
pack ice in which the concentration is 10/10 and the floes are frozen together


.topic 660
Nilas which is under 5 cm in thickness and is very dark in color.


.topic 700
Part of an inland ice sheet which the ice flows more rapidly and not necessarily in the same direction as the surrounding ice. The margins are sometimes clearly marked by a change in direction of the surface slope but may be indistinct.


.topic 710
Nilas which is more than 5 cm in thickness and rather lighter in color than dark nilas


.topic 740
Any non-linear shaped opening enclosed in ice. Polynyas may contain brash ice and/or be covered with new ice, nilas or young ice; submariners refer to these as skylights. Sometimes the polynya is limited on one side by the coast and is called a shore polynya or by fast ice and is called a flaw polynya. If it recurs in the same position every year, it is called a recursing polynya.


.topic 730
An accumulation on ice of melt-water, 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.


.topic 750
A line or wall of broken ice forced up by pressure. May be fresh or weathered. The submerged volume of broken ice under a ridge, forced downwards by pressure, is termed an ice keel

.topic 770

.topic 780
weathering: processes of ablation and accumulation which gradually eliminate irregularities in an ice surface.


