Abstract

This paper presents a non-invasive acoustic reflection technique to visualize sediment-laden flows over a wide range of sediment concentrations (5–75% by volume) in the laboratory. A Panametrics V301-SU Immersion transducer with 0.5 MHz center frequency was used to generate acoustic reflections that were sampled at 10 MHz. The strength of this technique is the direct characterization of both the internal structure of sediment-laden flows and their deposits, especially for high-concentration conditions. A combination of reflection continuity, amplitude, and mutual coherence were used to identify three distinct acoustic facies: short-scatter, long-scatter, and continuous-reflection. Here we present two examples in which the acoustic facies allows the interpretation of (a) the temporal evolution of internal mixing and stratification within a flow and contemporaneous deposition of its sediment and (b) the horizontal and vertical partitioning of mud and sand within a deposit generated by a sediment-laden flow.