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:
“We believe that civilization has been created under the pressure of the exigencies of life at the cost of satisfaction of the instincts.”
—Sigmund Freud (1856–1939)
“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)
“An accent mark, perhaps, instead of a whole western accent—a point of punctuation rather than a uniform twang. That is how it should be worn: as a quiet point of character reference, an apt phrase of sartorial allusion—macho, sotto voce.”
—Phil Patton (b. 1953)