scattering layer

Scientific  

1. A concentrated layer of marine organisms found in most oceanic waters that reflects and scatters sound waves, as from sonar. The layer is of varying composition and can include both plankton and nekton (free-swimming organisms such as copepods, krill, and small fish). Scattering layers, which may occur at more than one depth in the same location, typically move upward at night to feed on phytoplankton and downward during the day, as deep as 1,000 m (3,280 ft), probably to escape predators.

2. Also called deep scattering layer

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Example Sentences

The deep scattering layer, as it came to be known, is in fact created by sound waves bouncing off the gas-filled swim bladders of twilight zone fish and the bodies of other migrating animals, such as the relatives of jellyfish called siphonophores.

From National Geographic

Early recordings of diel migration date to World War II, when ships and submarines using sonar to sweep the oceans for enemy subs detected something odd—parts of the seafloor seemed to be moving up and down, creating a deep “scattering layer” that reflected the sonar signals.

From Scientific American

“From these preliminary observations there appears to be some direct correlation of the planktonic animals with the scattering layer,” Johnson wrote.

From Scientific American

This phenomenon we now call the deep scattering layer is made up of millions of small fish, but when viewed from 1951 its first detection retains enough proximity and mystery to send a shiver up one's spine.

From Scientific American

Then, during World War II, came the discovery of the “deep scattering layer”: a zone in the oceans that unexpectedly deflected pings of Navy sonar and mysteriously disappeared each night, like a phantom seabed.

From Scientific American