A
submarine canyon is a steep-sided
valley cut into the
sea floor of the
continental slope, sometimes extending well onto the
continental shelf and having relief comparable to even the largest of land canyons. About 3% of submarine
canyons are joined to shelf valleys that connect with large
rivers; the largest canyons (equal to about 29% by number) incise into the continental shelf but the largest number of canyons (about 69%) terminate on the slope, making so-called “blind” or “headless” canyons. Canyons cutting the continental slopes have been found at depths greater than 2 km below
sea level. Many submarine canyons continue as
submarine channels across continental rise areas and may extend seawards for hundreds of kilometres onto the abyssal plain. Ancient examples have been found in rocks dating back to the
Neoproterozoic.
Turbidites are formed in submarine canyons.