Deep-sea bottom currents: Their nature and distribution

Citation

Stow D, Smillie Z & Esentia I (2019) Deep-sea bottom currents: Their nature and distribution. In: Cochran JK, Bokuniewicz H & Yager P (eds.) Encyclopedia of Ocean Sciences, Vol. 4. 3rd edn ed. Reference Module in Earth Systems and Environmental Sciences. Academic Press, pp. 90-96. https://doi.org/10.1016/B978-0-12-409548-9.10878-4

Abstract
Bottom currents affect the deep-ocean water masses beneath the thermocline. The oceans are stratified according to their different physical properties. Each layer shows very sluggish movement, but has zones where flow speed is greater and distinct bottom currents can be identified. There are three main types recognized: wind-driven, thermohaline, and deep tidal currents. They are semi-continuous processes of long duration, but all show significant variability in speed, direction and sediment concentration. These currents erode, transport and deposit deep-sea sediment, leading to the deposition of contourites, contourite drifts and related sediment facies.

Keywords
Bottom current; Coriolis force; Current velocity; Eddies; Nepheloid layer; Oceanic gateway; Ocean stratification; Sedimentation rate; Surface current; Thermohaline circulation; Tidal current; Wind-driven circulation