Experimental investigation of subaqueous clay-rich debris flows, turbidity generation and sediment deposition

Abstract

The characteristics of submarine debris flows and the generated turbidity as well as their relationship with the deposit thickness are discussed herein. There is a gap in our understanding of the processes in which a submarine debris flow and the overriding turbidity form seabed deposits and how the deposits relate to the parent landslide. The experimental program reported here studied subaqueous gravity flows of different clay-rich slurries in a flume. The flume results provide insight into the thickness of the slurry flows with the overriding turbidity clouds and the deposited sediments and lays groundwork for future studies. The thickness of the slurry head tends to decrease with increasing slurry clay content whereas the thickness of the turbidity overriding the slurry head tends to decrease with increasing clay content. Further, the thickness of the deposited layer measured a few seconds after termination of the slurry flow increases with clay content. Geometrically, the flume experiments represented flowing debris of a landslide from 50 m to 120 m water depths with a 600 m travelling distance and downstream velocities between 5 and 13.5 m/s. © Springer Science + Business Media B.V. 2010.