Pipe and Sheet Flow
The flow of water under the glacial surface can have a large effect on the motion of the glacier itself. Subglacial lakes contain significant amounts of water, which can move fast: cubic kilometres can be transported between lakes over the course of a couple of years.
This motion is thought to occur in two main modes: pipe flow involves liquid water moving through pipe-like conduits, like a sub-glacial river; sheet flow involves motion of water in a thin layer. A switch between the two flow conditions may be associated with surging behaviour. Indeed, the loss of sub-glacial water supply has been linked with the shut-down of ice movement in the Kamb ice stream. The subglacial motion of water is expressed in the surface topography of ice sheets, which slump down into vacated subglacial lakes.
Read more about this topic: Ice Sheet Dynamics
Famous quotes containing the words pipe and, pipe, sheet and/or flow:
“Wind and Thistle for pipe and dancers
And never a ploughman under the Sun.
Never a ploughman. Never a one.”
—Hilaire Belloc (1870–1953)
“Blest are those
Whose blood and judgment are so well commingled
That they are not a pipe for Fortune’s finger
To sound what stop she please.”
—William Shakespeare (1564–1616)
“No Time, spoke the clocks, no God, rang the bells,
I drew the white sheet over the islands
And the coins on my eyelids sang like shells.”
—Dylan Thomas (1914–1953)
“Opinionated writing is always the most difficult ... simply because it involves retaining in the cold morning-after crystal of the printed word the burning flow of molten feeling.”
—Gavin Lyall (b. 1932)