Database-informed analysis of sedimentary systems at the marine shelf-to-slope transition

Submarine canyons and shelf-edge deltas are important elements of continental margins, which influence sediment transport dynamics across shelves and slopes to deep-water basins, and the storage of sediment. However, the factors that control their evolution and their relative importance remain poorly understood. Via three separate metastudies this thesis presents a quantitative, global study of submarine canyons and shelf-edge deltas in the context of (i) their physiographic setting, (ii) their associated source-to-sink (S2S) system, and (iii) their environmental setting, resulting in a novel quantitative characterisation of submarine canyons and shelf-edge deltas. The principal findings of this project are as follows: (i) Overall, scaling relationships of submarine canyons and shelf-edge deltas with descriptors of their physiographic setting and environment are weak, which reflects the complex influence of multiple factors, both allogenic and autogenic, on their geomorphologies, and how these factors might amplify, weaken or overprint a scaling relationship. (ii) Despite the complex and variable geomorphologies demonstrated for studied examples of submarine canyons and shelf-edge deltas, some morphometric attributes of both sedimentary system types do differ between environmental settings, indicating a greater genetic influence of certain individual environmental variables over others. (iii) Moderate and strong scaling of morphometric attributes in submarine canyons and shelf-edge deltas with each other, and with variables of the physiographic setting and associated S2S system, suggest that the geomorphologies of submarine canyons and shelf-edge deltas can be predicted to some degree, based on knowledge of their environmental setting, and vice versa. The findings from this project help to clarify the complex influence of multiple factors on the geomorphologies of submarine canyons and shelf-edge deltas, providing a framework for the prediction of their geomorphologic characteristics across environmental settings and for the integration of submarine canyons and shelf-edge deltas into S2S system analyses.