Seafloor slopes control submarine canyon distribution: A global analysis.

Abstract

Earth's continental margins are dissected by submarine canyons that convey sediments, carbon, and nutrients to the deep ocean, regulating global biogeochemical fluxes. Despite their importance in the Earth system, the controls on canyon occurrence remain poorly understood. We report results from a spatial statistical model that explains global canyon distribution. By analyzing >2000 canyons, we show that canyon occurrence correlates with the inclination of continental slopes. Onshore orogeny and associated surface processes, long considered key controls on canyon formation, play a subordinate role. Instead, our results suggest slope inclination as the primary control on submarine canyon density. Because continental slope morphology is fundamentally shaped by marine tectonic and thermal processes, these large-scale forces indirectly govern canyon formation and distribution globally. As a result, they influence the presence of pathways that facilitate the transfer of sediments, carbon, and nutrients to the deep ocean, with implications for biogeochemical cycles over geological timescales.