New insights into the structure of alluvial deposits using a parametric echosounder

SAMBROOK SMITH, G.; BEST, J.; ORFEO, O.; VARDY,M; ZINGER, J.

Leeds

Congreso; International Conference on Fluvial Sedimentology; 2013

University of Leeds

The key result from this work is that the PES is capable of generating images of subsurface structure beneath dunes with remarkable clarity and resolution (Fig. 1). The PES is able to capture contrasts in subsurface architecture at the decimetric scale i.e. comparable to ground penetrating radar (GPR). This allows the larger unit bar sets that are seen lower down in the profile to be imaged in addition to the individual bounding surfaces of dune sets from which set thickness can be measured. Additionally, the internal architecture of both active dunes at the surface and preserved dune sets can also be determined. The analysis of dune set thicknesses shows broad agreement with theory relating to thickness and dune height and depth but with a large degree of variability. Overall, the new high-resolution datasets of dune internal stratigraphy we present demonstrate how new understanding of dune preservation can be generated and how the PES has the potential to be a transformative tool in river science.