University of Hull logo

Self-sharpening induces jet-like structure in seafloor gravity currents

Dorrell, R. M.; Peakall, J.; Darby, S. E.; Parsons, D. R.; Johnson, J.; Sumner, E. J.; Wynn, R. B.; Özsoy, E.; Tezcan, D.

Authors

J. Peakall

S. E. Darby

J. Johnson

E. J. Sumner

R. B. Wynn

E. Özsoy

D. Tezcan

Abstract

Gravity currents are the primary means by which sediments, solutes and heat are transported across the ocean-floor. Existing theory of gravity current flow employs a statistically-stable model of turbulent diffusion that has been extant since the 1960s. Here we present the first set of detailed spatial data from a gravity current over a rough seafloor that demonstrate that this existing paradigm is not universal. Specifically, in contrast to predictions from turbulent diffusion theory, self-sharpened velocity and concentration profiles and a stable barrier to mixing are observed. Our new observations are explained by statistically-unstable mixing and self-sharpening, by boundary-induced internal gravity waves; as predicted by recent advances in fluid dynamics. Self-sharpening helps explain phenomena such as ultra-long runout of gravity currents and restricted growth of bedforms, and highlights increased geohazard risk to marine infrastructure. These processes likely have broader application, for example to wave-turbulence interaction, and mixing processes in environmental flows.

Journal Article Type Article
Publication Date 2019-12
Journal Nature Communications
Electronic ISSN 2041-1723
Publisher Nature Publishing Group
Peer Reviewed Peer Reviewed
Volume 10
Issue 1
Article Number 1381
Institution Citation Dorrell, R. M., Peakall, J., Darby, S. E., Parsons, D. R., Johnson, J., Sumner, E. J., …Tezcan, D. (2019). Self-sharpening induces jet-like structure in seafloor gravity currents. Nature communications, 10(1), https://doi.org/10.1038/s41467-019-09254-2
DOI https://doi.org/10.1038/s41467-019-09254-2
Keywords General Biochemistry, Genetics and Molecular Biology; General Physics and Astronomy; General Chemistry
Publisher URL https://www.nature.com/articles/s41467-019-09254-2

Files

Article (2.2 Mb)
PDF

Copyright Statement
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.




You might also like


Downloadable Citations