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:
“This is a catastrophic universe, always; and subject to sudden reversals, upheavals, changes, cataclysms, with joy never anything but the song of substance under pressure forced into new forms and shapes.”
—Doris Lessing (b. 1919)
“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)
“Some parents feel that if they introduce their children to alcohol gradually in the home environment, the children will learn to use alcohol in moderation. I’m not sure that’s such a good idea. First of all, alcohol is not healthy for the growing child. Second, introducing alcohol to a child suggests that you condone drinking—even to the point where you want to teach your child how to drink.”
—Lawrence Balter (20th century)