Detailed Seafloor Imagery of Turbidity Current Bedforms Reveals New Insight Into Fine-Scale Near-Bed Processes

High-resolution imagery of the morphological character of modern active turbidite systems are critical for understanding the complexity of turbidity current processes occurring on the seafloor. Here, we describe a 30 cm-resolution autonomous underwater vehicle repeat bathymetric dataset that allows to significantly increase the geomorphological detail of crescentic bedforms in turbidite systems. This repeat imagery shows the erosion produced by dense basal layers at the base of turbidity currents, the inception of plunge pools, and the controls that hydraulic jump troughs have on subsequent flow path of weaker turbidity currents. Transverse small-scale scours located in cyclic step troughs suggest that weak flows follow local relief, therefore explaining the wide variability of turbidity current flow indicators observed in outcrops. This imagery demonstrates that turbidite systems are formed by the superimposition of erosion surfaces and depositional patterns recording contrasted flow behavior and provides new views on turbidity current behavior in natural environments.

Automated summary

High-resolution imagery of modern active turbidite systems reveals detailed information about the morphology and behavior of turbidity currents. This study presents a dataset obtained from an autonomous underwater vehicle with 30 cm-resolution, which provides new insights into the erosional and depositional processes associated with turbidity currents. The imagery shows the impact of basal layer erosion, the formation of plunge pools, and the influence of hydraulic jump troughs on flow paths. Additionally, small-scale scours suggest that weak flows follow local relief and explain the variability of flow indicators observed in outcrops.