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:
“He who is of a calm and happy nature will hardly feel the pressure of age, but to him who is of an opposite disposition youth and age are equally a burden.”
—Plato (c. 427–347 B.C.)
“Since to the awe of thy imperious wit
Our troublesome language bends, made only fit
With her tough thick-ribbed hoops to gird about
Thy giant fancy, which had proved too stout
For their soft melting phrases.”
—Thomas Carew (1589–1639)
“This was a great point gained; the archdeacon would certainly not come to morning service at Westminster Abbey, even though he were in London; and here the warden could rest quietly, and, when the time came, duly say his prayers.”
—Anthony Trollope (1815–1882)