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:
“Amid the pressure of great events, a general principle gives no help.”
—Georg Wilhelm Friedrich Hegel (1770–1831)
“O ruddier than the cherry,
O sweeter than the berry,
O Nymph more bright
Than moonshine night,
Like kidlings blithe and merry.
Ripe as the melting cluster,
No lily has such lustre,
Yet hard to tame,
As raging flame,
And fierce as storms that bluster.”
—John Gay (1685–1732)
“The trouble with Reason is that it becomes meaningless at the exact point where it refuses to act.”
—Bernard Devoto (1897–1955)