Internal Waves in The Ocean
Most people think of waves as a surface phenomenon, which acts between water (as in lakes or oceans) and the air. Where low density water overlies high density water in the ocean, internal waves propagate along the boundary. They are especially common over the continental shelf regions of the world oceans and where brackish water overlies salt water at the outlet of large rivers. There is typically little surface expression of the waves, aside from slick bands that can form over the trough of the waves.
Internal waves are the source of a curious phenomenon called dead water, first reported by the Norwegian oceanographer Fridtjof Nansen, in which a boat may experience strong resistance to forward motion in apparently calm conditions. This occurs when the ship is sailing on a layer of relatively fresh water whose depth is comparable to the ship's draft. This causes a wake of internal waves that dissipates a lot of energy.
Read more about this topic: Internal Wave
Famous quotes containing the words internal, waves and/or ocean:
“Unlike femininity, relaxed masculinity is at bottom empty, a limp nullity. While the female body is full of internal potentiality, the male is internally barren.... Manhood at the most basic level can be validated and expressed only in action.”
—George Gilder (b. 1939)
“With these I would be.
And with water: the waves coming forward, without cessation,
The waves, altered by sand-bars, beds of kelp, miscellaneous
driftwood,
Topped by cross-winds, tugged at by sinuous undercurrents
The tide rustling in, sliding between the ridges of stone,
The tongues of water, creeping in, quietly.”
—Theodore Roethke (1908–1963)
“We only seem to learn from Life that Life doesn’t matter so much as it seemed to do—it’s not so burningly important, after all, what happens. We crawl, like blinking sea-creatures, out of the Ocean onto a spur of rock, we creep over the promontory bewildered and dazzled and hurting ourselves, then we drop in the ocean on the other side: and the little transit doesn’t matter so much.”
—D.H. (David Herbert)