The Black Sea flow provides a unique natural laboratory to study the dynamics of sea floor density-driven flow. The team measured the density-driven flow in unprecedented detail by flying a state-of-the-art 2.4 tonne, 7 metre submersible marine robot (Autosub III) at speeds up to 10 km per hour within a full-scale deep-ocean density current, less than 5m above the seafloor, for the first time.
Dr Dorrell, lead author, said: “The field measurements represent a true step-change, as the new level of detail provided shows that large-scale mixing processes drive self-organisation in the flow. The emergence of self-organisation, from chaotic turbulent fluid motion, is fascinating, operating against preconceived notions of increasing entropy, and demonstrates higher levels of physical complexity than was previously understood. By demonstrating self-organisation of the flow, and thus a stable mechanism for reducing mixing with the surrounding water, we are now able to explain how density-driven flows travel so far.”
Professor Jeff Peakall, project principal investigator, from the School of Earth and Environment at the University of Leeds, said:“These deep-sea channels are some of the least understood natural systems on our planet. There has been more attention given to the channels on Mars than to these density-driven flows, despite their important role in transporting carbon, nutrients and heat across the deep-sea floor. Our research explains for the first time how these massive flows are able to travel such vast distances. Improving our understanding of the huge power of these flows will help us better safeguard vital continent-spanning deep-sea infrastructure.”
The international research team included colleagues from the Universities of Leeds and Southampton, the Middle East Technical and the Istanbul Technical Universities, and the UK’s National Oceanography Centre (NOC). Their research findings are critical to forecasting the real hazard risks these flows can pose to critical seafloor infrastructure, such as submarine telecommunications cables, which carry over 95% of global internet traffic, and oil and gas pipelines.
The seafloor channel of the Black Sea density-driven flow