Benthic biology influences sedimentation in submarine channel bends: Coupling of biology, sedimentation and flow

Azpiroz-Zabala, M.; Sumner, E. J.; Cartigny, M. J.B.; Peakall, J.; Clare, M. A.; Darby, S. E.; Parsons, D. R.; Dorrell, R. M.; Özsoy, E.; Tezcan, D.; Wynn, R. B.; Johnson, J.

Abstract

Submarine channels are key features for the transport of flow and nutrients into deep water. Previous studies of their morphology and channel evolution have treated these systems as abiotic, and therefore assume that physical processes are solely responsible for morphological development. Here, a unique dataset is utilised that includes spatial measurements around a channel bend that hosts active sediment gravity flows. The data include flow velocity and density, alongside bed grain size and channel-floor benthic macrofauna. Analysis of these parameters demonstrate that while physical processes control the broadest scale variations in sedimentation around and across the channel, benthic biology plays a critical role in stabilising sediment and trapping fines. This leads to much broader mixed grain sizes than would be expected from purely abiotic sedimentation, and the maintenance of sediment beds in positions where all the sediment should be actively migrating. Given that previous work has also shown that submarine channels can be biological hotspots, then the present study suggests that benthic biology probably plays a key role in channel morphology and evolution, and that these need to be considered both in the modern and when considering examples preserved in the rock record.

Citation

Azpiroz-Zabala, M., Sumner, E. J., Cartigny, M. J., Peakall, J., Clare, M. A., Darby, S. E., …Johnson, J. (2024). Benthic biology influences sedimentation in submarine channel bends: Coupling of biology, sedimentation and flow. The Depositional Record, https://doi.org/10.1002/dep2.265

• Journal Article Type: Article
• Acceptance Date: Dec 15, 2023
• Online Publication Date: Jan 29, 2024
• Publication Date: 2024
• Deposit Date: Feb 19, 2024
• Publicly Available Date: Feb 20, 2024
• Journal: Depositional Record
• Electronic ISSN: 2055-4877
• Publisher: International Association of Sedimentologists
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.1002/dep2.265
• Keywords: Gravity flow; Interplay flow-sediment-biology; Subaqueous channel evolution; Submarine channel bend
• Public URL: https://hull-repository.worktribe.com/output/4548949