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:
“Destiny is an absolutely definite and inexorable ruler. Physical ability and moral determination count for nothing. It is impossible to perform the simplest act when the gods say “no.” I have no idea how they bring pressure to bear on such occasions; I only know that it is irresistible.”
—Aleister Crowley (1875–1947)
“Fearful of sentimentality, I disown my tears and melting heart.”
—Mason Cooley (b. 1927)
“The point is, that the function of the novel seems to be changing; it has become an outpost of journalism; we read novels for information about areas of life we don’t know—Nigeria, South Africa, the American army, a coal-mining village, coteries in Chelsea, etc. We read to find out what is going on. One novel in five hundred or a thousand has the quality a novel should have to make it a novel—the quality of philosophy.”
—Doris Lessing (b. 1919)