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 universal social pressure upon women to be all alike, and do all the same things, and to be content with identical restrictions, has resulted not only in terrible suffering in the lives of exceptional women, but also in the loss of unmeasured feminine values in special gifts. The Drama of the Woman of Genius has too often been a tragedy of misshapen and perverted power.”
—Anna Garlin Spencer (1851–1931)
“Slow, slow, fresh fount, keep time with my salt tears;
Yet slower yet, oh faintly gentle springs:
List to the heavy part the music bears,
“Woe weeps out her division when she sings.”
Droop herbs and flowers;
Fall grief in showers;
“Our beauties are not ours”:
Oh, I could still,
Like melting snow upon some craggy hill,
Drop, drop, drop, drop,
Since nature’s pride is, now, a withered daffodil.”
—Ben Jonson (1572–1637)
“From a purely external point of view there is no will; and to find will in any phenomenon requires a certain empathy; we observe a man’s actions and place ourselves partly but not wholly in his position; or we act, and place ourselves partly in the position of an outsider.”
—T.S. (Thomas Stearns)