|
|
|
|
|
| Hage, Sophie; Cartigny, Matthieu J.b.; Sumner, Esther J.; Clare, Michael A.; Hughes Clarke, John E.; Talling, Peter J.; Lintern, D. Gwyn; Simmons, Stephen M.; Silva Jacinto, Ricardo; Vellinga, Age J.; Allin, Joshua R.; Azpiroz‐zabala, Maria; Gales, Jenny A.; Hizzett, Jamie L.; Hunt, James E.; Mozzato, Alessandro; Parsons, Daniel R.; Pope, Ed L.; Stacey, Cooper D.; Symons, William O.; Vardy, Mark E.; Watts, Camilla. |
| Rivers (on land) and turbidity currents (in the ocean) are the most important sediment transport processes on Earth. Yet, how rivers generate turbidity currents as they enter the coastal ocean remains poorly understood. The current paradigm, based on laboratory experiments, is that turbidity currents are triggered when river plumes exceed a threshold sediment concentration of ~1 kg.m‐3. Here we present direct observations of an exceptionally dilute river‐plume, with sediment concentrations one order of magnitude below this threshold (0.07 kg.m‐3), which generated a fast (1.5 m.s‐1), erosive, short‐lived (6 min) turbidity current. However, no turbidity current occurred during subsequent river‐plumes. We infer that turbidity currents are generated when... |
| Tipo: Text |
|
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00514/62594/66952.pdf |
| |
|
|
| Clare, Michael; Lintern, D. Gwyn; Rosenberger, Kurt; Hughes Clarke, John E.; Paull, Charles; Gwiazda, Roberto; Cartigny, Matthieu J. B.; Talling, Peter J.; Perara, Daniel; Xu, Jingping; Parsons, Daniel; Silva Jacinto, Ricardo; Apprioual, Ronan. |
| Turbidity currents transport globally significant volumes of sediment and organic carbon into the deep-sea and pose a hazard to critical infrastructure. Despite advances in technology, their powerful nature often damages expensive instruments placed in their path. These challenges mean that turbidity currents have only been measured in a few locations worldwide, in relatively shallow water depths (,,2 km). Here, we share lessons from recent field deployments about how to design the platforms on which instruments are deployed. First, we show how monitoring platforms have been affected by turbidity currents including instability, displacement, tumbling and damage. Second, we relate these issues to specifics of the platform design, such as exposure of large... |
| Tipo: Text |
|
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00640/75200/75333.pdf |
| |
|
|
|
