Many canyons are associated with major rivers such as the Congo, Hudson, and others. The depth of the rise ranges from 2000 to 5000 meters deep. Its breadth is up 300 kilometers wide. This feature was created by the merging of accumulated deposits at the mouths of the many submarine canyons. Each canyon's thick fan-shaped sedimentary deposit is called an abyssal fans .
Numerous volcanoes populate the floor of the ocean basins.
Scientists estimate that there are approximately 10,000 volcanoes on the ocean floor. These features are involved in the generation of new oceanic crust from volcanic fissures produced by mantle up-welling. In the center of the mid-oceanic ridge is a rift valley, between 30 to 50 kilometers wide, that dissects 1000 to 3000 meters deep into the ridge system. Generally, the trenches mark the transition between continents and ocean basins, especially in the Pacific basin. Trenches are also the tectonic areas where oceanic crust is subducted and melted back into the mantle.