Fig. 5: Schematic model comparing landslide-dam impacts on rivers and turbidity currents in submarine canyons.
From: Carbon and sediment fluxes inhibited in the submarine Congo Canyon by landslide-damming
a, Terrestrial landslide-dammed river. Fluvial landslide-dam traps water and sediment. Trapped water forms a lake behind the dam, and deltaic sediment is deposited when river water enters the lake or within the body of the lake. Once accommodation space has been filled, river water is able to overtop the dam and continue downstream. b, Submarine landslide-dam. Landslide-dam blocks the submarine canyon, interrupting the passage of turbidity currents. c, Partial flow reflection and ponding. Landslide-dam results in trapping, ponding and reflection of turbidity currents. d, Turbidity current deposits backfill accommodation space behind landslide-dam. As turbidity currents depend on their velocity to keep sediment entrained, this sediment is rapidly deposited. Parts of the turbidity current that are able to overtop the landslide-dam quickly dissipate as their sediment load is now greatly reduced. e, Gradual sediment release. Once the accommodation space is filled, more-erosive, faster-moving parts of turbidity currents are able to overtop the dam. These are able to erode the dam, leading to knickpoint formation as a new channel is incised into the infill. Turbidity current in panel b is a scaled representation of the flows described in ref. 8 under a CC BY license.
