New paper on lobe thickness scales in steep and sandy submarine fans

Our paper on the connection between hydraulic and sediment transport processes and channel and lobe geometry in supercritical submarine fans was recently published in Journal of Sedimentary Research.

Hamilton, P., Gaillot, G., Strom, K., Fedele, J., and Hoyal, D. (2017). Linking hydraulic properties in supercritical submarine distributary channels to depositional-lobe geometry. Journal of Sedimentary Research, 87(9):935-950. doi: 10.2110/jsr.2017.53

The ratio of lobe thickness to channel depth versus densimetric Froude number. The solid black line represents the sequent depth ratio defined by a simple momentum balance.

For the study, we use a set of laboratory experiments from Paul Hamilton’s PhD work and high-resolution seismic data from the Golo fan, developed by Gwladys Gaillot from ExxonMobil, to explore the ability of 1D-hydraulic equations to provide insight on vertical deposit scales within nested lobate bodies at the end of supercritical distributary channels. Specifically, we hypothesize that higher Froude numbers will lead to lobate deposits that have larger ratios of lobe-element thickness to channel depth compared to those produced at lower Froude numbers. Both the laboratory and field data support this hypothesis. However, the conclusions are dependent on the correct hierarchical linkage between elements in the field and in experiments. In the analysis, the maximum lobe-element thickness was found to be well approximated by the sequent depth of the supercritical flow in the distributary channel. Therefore, this approximation yields a prediction of the lobe-element thickness based only on the hydraulic properties of the distributary channel without the need for any calibration or regression coefficients in the prediction (see figure).