Melissa J. Craig
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.
Jaco H. Baas
Kathryn J. Amos
Lorna J. Strachan
Andrew J. Manning
David M. Paterson
Julie A. Hope
Scott D. Nodder
Dr Megan Baker email@example.com
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. https://doi.org/10.1130/g46837.1
|Journal Article Type||Article|
|Acceptance Date||Oct 4, 2019|
|Online Publication Date||Oct 19, 2019|
|Deposit Date||Mar 20, 2020|
|Publicly Available Date||Jul 1, 2020|
|Publisher||Geological Society of America|
|Peer Reviewed||Peer Reviewed|
Published Journal Article
Publisher Licence URL
© 2019 The Authors. Gold Open Access: This paper is published under the terms of the CC-BY license.
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