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:
“I am dead against art’s being self-expression. I see an inherent failure in any story which fails to detach itself from the author—detach itself in the sense that a well-blown soap-bubble detaches itself from the bowl of the blower’s pipe and spherically takes off into the air as a new, whole, pure, iridescent world. Whereas the ill-blown bubble, as children know, timidly adheres to the bowl’s lip, then either bursts or sinks flatly back again.”
—Elizabeth Bowen (1899–1973)
““Wotever is, is right, as the young nobleman sveetly remarked wen they put him down in the pension list ‘cos his mother’s uncle’s vife’s grandfather vunce lit the king’s pipe vith a portable tinder-box.””
—Charles Dickens (1812–1870)
“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)
“But even suppose blood should flow. Is there not a sort of blood shed when the conscience is wounded? Through this wound a man’s real manhood and immortality flow out, and he bleeds to an everlasting death. I see this blood flowing now.”
—Henry David Thoreau (1817–1862)