The Continental Shelf and Continental Slope

The continental shelf and continental slope, with a combined surface area equivalent to about 55% of the entire continental landmass, represent a key part of the sediment cycle. Rivers, glaciers and coastal erosion input about 20.8 × 19.1 × 1012 kg yr−1 of sediment to the continental slope. Of this, about 19.1 × 1012 kg yr−1 accumulates on the continental shelf and slope. However, the dynamics of the sediment cascade in this environment are poorly understood. In particular, few continental shelves have adequately constrained sediment budgets, and little is known about the role of high-magnitude–low-frequency mass movements on the continental slope in moving sediment into the deep ocean. Recent research shows that density currents can occur under a greater range of circumstances than previously understood, and that submarine mass movements can move sediment considerable distances on to the abyssal plains.