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:
“You will see Coleridgehe who sits obscure
In the exceeding lustre and the pure
Intense irradiation of a mind,
Which, with its own internal lightning blind,
Flags wearily through darkness and despair
A cloud-encircled meteor of the air,
A hooded eagle among blinking owls.”
—Percy Bysshe Shelley (17921822)
“the whole sea become an entanglement of watery bodies
lost to the world bearing what they cannot hold. Broken,
beaten, desolate, reaching from the dead to be taken up
they cry out, failing, failing! their cries rising
in waves still as the skillful yachts pass over.”
—William Carlos Williams (18831963)
“To the Ocean now I fly,
And those happy climes that ly
Where day never shuts his eye,
Up in the broad fields of the sky:”
—John Milton (16081674)