Nepheloid layer

The Gulf of Mexico, which contains a significant nepheloid layer

A nepheloid layer or nepheloid zone is a layer of water in the deep ocean basin, above the ocean floor, that contains significant amounts of suspended sediment.[1] It is from 200 to 1000 m thick. The name comes from Greek: nephos, "cloud". The particles in the layer may come from the upper ocean layers and from stripping the sediments from the ocean floor by currents.[2] Its thickness depends on bottom current velocity and is a result of balance between gravitational settling of particles and turbulence of the current. The formation mechanisms of nepheloid layers may vary, but primarily depend on deep ocean convection. Nepheloid layers can impact the accuracy of instruments when measuring bathymetry as well as affect the types of marine life in an area. There are several significant examples of nepheloid layers across the globe, including within the Gulf of Mexico and the Porcupine Bank.

  1. ^ Glossary of Geology, 5th Edition (American Geological Institute)
  2. ^ Hunkins, Kenneth; Thorndike, Edward; Mathieu, Guy (1969). "Nepheloid layers and bottom currents in the Arctic Ocean". Journal of Geophysical Research. 74 (28): 6995–7008. Bibcode:1969JGR....74.6995H. doi:10.1029/JC074i028p06995.