This term is used in the glaciological literature to refer to the melting point of ice under pressure. As the pressure increases in the downward direction, the melting temperature of ice decreases. This pressure melting point can reach values many degrees below 0°C.
Due to geothermal heat flux from below, the temperature at the same time increases. The level where ice can start melting is where the pressure melting point equals the actual temperature. In static equilibrium conditions, this would be the highest level where water can exist in a glacier. It would also be the level of the base of an ice shelf, or the ice-water interface of a subglacial lake.
Famous quotes containing the words pressure, melting and/or point:
“The area [of toilet training] is one where a child really does possess the power to defy. Strong pressure leads to a powerful struggle. The issue then is not toilet training but who holds the reins—mother or child? And the child has most of the ammunition!”
—Dorothy Corkville Briggs (20th century)
“Pushkin’s composition is first of all and above all a phenomenon of style, and it is from this flowered rim that I have surveyed its seep of Arcadian country, the serpentine gleam of its imported brooks, the miniature blizzards imprisoned in round crystal, and the many-hued levels of literary parody blending in the melting distance.”
—Vladimir Nabokov (1899–1977)
“I stand here tonight to say that we have never known defeat; we have never been vanquished. We have not always reached the goal toward which we have striven, but in the hour of our greatest disappointment we could always point to our battlefield and say: “There we fought our good fight, there we defended the principles for which our ancestors and yours laid down their lives; there is our battlefield for justice, equality and freedom. Where is yours?””
—Anna Howard Shaw (1847–1919)