Seabed seismographs reveal duration and structure of longest runout sediment flows on Earth

Baker, Megan L.; Talling, Peter J.; Burnett, Richard; Pope, Ed L.; Ruffell, Sean C.; Urlaub, Morelia; Clare, Michael A.; Jenkins, Jennifer; Dietze, Michael; Neasham, Jeffrey; Silva Jacinto, Ricardo; Hage, Sophie; Hasenhündl, Martin; Simmons, Steve M.; Heerema, Catharina J.; Heijnen, Maarten S.; Kunath, Pascal; Cartigny, Matthieu J.B.; McGhee, Claire; Parsons, Daniel R.

Abstract

Turbidity currents carve the deepest canyons on Earth, deposit its largest sediment accumulations, and break seabed telecommunication cables. Powerful canyon-flushing turbidity currents break sensors placed in their path, making them notoriously challenging to measure, and thus poorly understood. This study provides the first remote measurements of canyon-flushing flows, using ocean-bottom seismographs located outside the flow's destructive path, revolutionizing flow monitoring. We recorded the internal dynamics of the longest sediment flows yet monitored on Earth, which traveled >1,000km down the Congo Canyon-Channel at 3.7–7.6m s−1 and lasted >3weeks. These observations allow us to test fundamental models for turbidity current behavior and reveal that flows contain dense and fast frontal-zones up to ∼400km in length. These frontal-zones developed near-uniform durations and speeds for hundreds of kilometres despite substantial seabed erosion, enabling flows to rapidly transport prodigious volumes of organic carbon, sediment, and warm water to the deep-sea.

Citation

Baker, M. L., Talling, P. J., Burnett, R., Pope, E. L., Ruffell, S. C., Urlaub, M., Clare, M. A., Jenkins, J., Dietze, M., Neasham, J., Silva Jacinto, R., Hage, S., Hasenhündl, M., Simmons, S. M., Heerema, C. J., Heijnen, M. S., Kunath, P., Cartigny, M. J., McGhee, C., & Parsons, D. R. (2024). Seabed seismographs reveal duration and structure of longest runout sediment flows on Earth. Geophysical research letters, 51(23), Article e2024GL111078. https://doi.org/10.1029/2024GL111078

• Journal Article Type: Article
• Acceptance Date: Nov 6, 2024
• Online Publication Date: Nov 28, 2024
• Publication Date: Dec 16, 2024
• Deposit Date: Nov 19, 2024
• Publicly Available Date: Dec 5, 2024
• Journal: Geophysical Research Letters
• Print ISSN: 0094-8276
• Publisher: American Geophysical Union
• Peer Reviewed: Peer Reviewed
• Volume: 51
• Issue: 23
• Article Number: e2024GL111078
• DOI: https://doi.org/10.1029/2024GL111078
• Keywords: Seismic monitoring; Turbidity currents; Ocean fluxes; Ocean-bottom seismographs; Organic carbon
• Public URL: https://hull-repository.worktribe.com/output/4920620