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Long‐range sediment transport in the world's oceans by stably stratified turbidity currents
Author(s) -
Kneller Benjamin,
NasrAzadani Mohamad M.,
Radhakrishnan Senthil,
Meiburg Eckart
Publication year - 2016
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1002/2016jc011978
Subject(s) - turbidity current , turbidity , submarine , current (fluid) , sediment , sedimentation , entrainment (biomusicology) , richardson number , geology , dissipation , range (aeronautics) , turbidite , oceanography , environmental science , geomorphology , mechanics , turbulence , physics , materials science , sedimentary depositional environment , rhythm , acoustics , composite material , thermodynamics , structural basin
Submarine fans, supplied primarily by turbidity currents, constitute the largest sediment accumulations on Earth. Generally accepted models of turbidity current behavior imply they should dissipate rapidly on the very small gradients of submarine fans, thus their persistence over long distances is enigmatic. We present numerical evidence, constrained by published field data, suggesting that turbidity currents traveling on low slopes and carrying fine particles have a stably stratified shear layer along their upper interface, which dramatically reduces dissipation and entrainment of ambient fluid, allowing the current to propagate over long distances. We propose gradient Richardson number as a useful criterion to discriminate between the different behaviors exhibited by turbidity currents on high and low slopes.