Ocean-bottom seismometers reveal surge dynamics in Earth’s longest-runout sediment flows

Kunath, Pascal; Talling, Peter J.; Lange, Dietrich; Chi, Wu-Cheng; Baker, Megan L.; Urlaub, Morelia; Berndt, Christian

Abstract

Turbidity currents carve Earth’s deepest canyons, form Earth’s largest sediment deposits, and break seabed telecommunications cables. Directly measuring turbidity currents is notoriously challenging due to their destructive impact on instruments within their path. This is especially the case for canyon-flushing flows that can travel >1000 km at >5 m/s, whose dynamics are poorly understood. We deployed ocean-bottom seismometers safely outside turbidity currents, and used emitted seismic signals to remotely monitor canyon-flushing events. By analyzing seismic power variations with distance and signal polarization, we distinguish signals generated by turbulence and sediment transport and document the evolving internal speed and structure of flows. Flow-fronts have dense near-bed layers comprising multiple surges with 5-to-30-minute durations, continuing for many hours. Fastest surges occur 30–60 minutes behind the flow-front, providing momentum that sustains flow-fronts for >1000 km. Our results highlight surging within dense near-bed layers as a key driver of turbidity currents’ long-distance runout.

Citation

Kunath, P., Talling, P. J., Lange, D., Chi, W.-C., Baker, M. L., Urlaub, M., & Berndt, C. (2025). Ocean-bottom seismometers reveal surge dynamics in Earth’s longest-runout sediment flows. Communications Earth & Environment, 6(1), Article 147. https://doi.org/10.1038/s43247-025-02137-z

• Journal Article Type: Article
• Acceptance Date: Feb 14, 2025
• Online Publication Date: Feb 25, 2025
• Publication Date: Feb 25, 2025
• Deposit Date: Feb 25, 2025
• Publicly Available Date: Feb 25, 2025
• Journal: Communications Earth & Environment
• Electronic ISSN: 2662-4435
• Publisher: Nature Research
• Peer Reviewed: Peer Reviewed
• Volume: 6
• Issue: 1
• Article Number: 147
• DOI: https://doi.org/10.1038/s43247-025-02137-z
• Public URL: https://durham-repository.worktribe.com/output/3547678