Skip to main content

Research Repository

Advanced Search

Biomediation of submarine sediment gravity flow dynamics

Craig, Melissa J.; Baas, Jaco H.; Amos, Kathryn J.; Strachan, Lorna J.; Manning, Andrew J.; Paterson, David M.; Hope, Julie A.; Nodder, Scott D.; Baker, Megan L.

Biomediation of submarine sediment gravity flow dynamics Thumbnail


Melissa J. Craig

Jaco H. Baas

Kathryn J. Amos

Lorna J. Strachan

Andrew J. Manning

David M. Paterson

Julie A. Hope

Scott D. Nodder


Sediment gravity flows are the primary process by which sediment and organic carbon are transported from the continental margin to the deep ocean. Up to 40% of the total marine organic carbon pool is represented by cohesive extracellular polymeric substances (EPS) produced by microorganisms. The effect of these polymers on sediment gravity flows has not been investigated, despite the economic and societal importance of these flows. We present the first EPS concentrations measured in deep-sea sediment, combined with novel laboratory data that offer insights into the modulation of the dynamics of clay-laden, physically cohesive sediment gravity flows by biological cohesion. We show that EPS can profoundly affect the character, evolution, and runout of sediment gravity flows and are as prevalent in deep oceans as in shallow seas. Transitional and laminar plug flows are more susceptible to EPS-induced changes in flow properties than turbulent flows. At relatively low concentrations, EPS markedly decrease the head velocity and runout distance of transitional flows. This biological cohesion is greater, per unit weight, than the physical cohesion of cohesive clay and may exert a stronger control on flow behavior. These results significantly improve our understanding of the effects of an unrealized biological component of sediment gravity flows. The implications are wide ranging and may influence predictive models of sediment gravity flows and advance our understanding about the ways in which these flows transport and bury organic carbon globally.


Craig, M. J., Baas, J. H., Amos, K. J., Strachan, L. J., Manning, A. J., Paterson, D. M., …Baker, M. L. (2020). Biomediation of submarine sediment gravity flow dynamics. Geology, 48(1), 72-76.

Journal Article Type Article
Acceptance Date Oct 4, 2019
Online Publication Date Oct 19, 2019
Publication Date 2020-01
Deposit Date Mar 20, 2020
Publicly Available Date Jul 1, 2020
Journal Geology
Print ISSN 0091-7613
Electronic ISSN 1943-2682
Publisher Geological Society of America
Peer Reviewed Peer Reviewed
Volume 48
Issue 1
Pages 72-76


You might also like

Downloadable Citations