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)
“Some days your hat’s off to the full-time mothers for being able to endure the relentless routine and incessant policing seven days a week instead of two. But on other days, merely the image of this woman crafting a brontosaurus out of sugar paste and sheet cake for her two-year-old’s birthday drives a stake through your heart.”
—Melinda M. Marshall (20th century)
“For as the interposition of a rivulet, however small, will occasion the line of the phalanx to fluctuate, so any trifling disagreement will be the cause of seditions; but they will not so soon flow from anything else as from the disagreement between virtue and vice, and next to that between poverty and riches.”
—Aristotle (384–322 B.C.)