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)
“It is not that the Englishman can’t feel—it is that he is afraid to feel. He has been taught at his public school that feeling is bad form. He must not express great joy or sorrow, or even open his mouth too wide when he talks—his pipe might fall out if he did.”
—E.M. (Edward Morgan)
“There is a continual exchange of ideas between all minds of a generation. Journalists, popular novelists, illustrators, and cartoonists adapt the truths discovered by the powerful intellects for the multitude. It is like a spiritual flood, like a gush that pours into multiple cascades until it forms the great moving sheet of water that stands for the mentality of a period.”
—Auguste Rodin (1849–1917)
“On the idle hill of summer,
Sleepy with the flow of streams,”
—A.E. (Alfred Edward)