Direct Monitoring Reveals Initiation of Turbidity Currents From Extremely Dilute River Plumes.

ABSTRACT: 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/m³. Here we present direct observations of an exceptionally dilute river plume, with sediment concentrations 1 order of magnitude below this threshold (0.07 kg/m³), which generated a fast (1.5 m/s), erosive, short-lived (6 min) turbidity current. However, no turbidity current occurred during subsequent river plumes. We infer that turbidity currents are generated when fine sediment, accumulat

SUBMITTER: Hage S 

PROVIDER: S-EPMC6919390 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature