Abstract

Turbidity currents are sediment-laden flows that travel over a sloping bed under a stagnant ambient fluid, driven by the density difference between the current and the ambient. Turbidity currents transport large amounts of carbon, nutrients and fresh water through oceans and play an important role in global geochemical cycling and seafloor ecosystems. Supercritical currents are observed in steeper slopes. Subcritical currents are observed in milder slopes, where the near-bed and interface layers are prevented from interacting across the velocity maximum. Past works show the existence of such a barrier to vertical momentum transfer is essential for the body of the subcritical current to extend over hundreds of kilometers in length without much increase in height. Here we observe the body of subcritical currents to have a three layer structure, where the turbulent near-bed layer and the non-turbulent interface layer are separated by an intermediate layer of negative turbulence production. We explain the mechanism by which this layer prevents the near-bed turbulent structures from penetrating into the interface layer by transferring energy back from turbulence to the mean flow.

This study investigates the underlying physical mechanisms of turbidity currents travelling thousands of miles in confined submarine settings, rather than diffusing after short distance. Using high resolution simulations with up to a billion grid points helps to understand the evolving layered structure of a current.

Details

Title
Anatomy of subcritical submarine flows with a lutocline and an intermediate destruction layer
Author
Salinas, Jorge S 1   VIAFID ORCID Logo  ; Balachandar, S 1   VIAFID ORCID Logo  ; Shringarpure, M 2 ; Fedele, J 2 ; Hoyal, D 2 ; Zuñiga, S 3 ; Cantero, M I 3 

 University of Florida, Department of Mechanical and Aerospace Engineering, Gainesville, USA (GRID:grid.15276.37) (ISNI:0000 0004 1936 8091) 
 ExxonMobil Upstream Research Company, Houston, USA (GRID:grid.421234.2) (ISNI:0000 0004 1112 1641) 
 Instituto Balseiro, Universidad Nacional de Cuyo, San Carlos de Bariloche, Argentina (GRID:grid.466813.e); Comisión Nacional de Energía Atómica, Centro Atómico Bariloche, San Carlos de Bariloche, Argentina (GRID:grid.418851.1) (ISNI:0000000417842677); Consejo Nacional de Investigaciones Científicas y Técnicas, San Carlos de Bariloche, Argentina (GRID:grid.423606.5) (ISNI:0000 0001 1945 2152) 
Publication year
2021
Publication date
2021
Publisher
Nature Publishing Group
e-ISSN
20411723
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2500686239
Copyright
© The Author(s) 2021. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.