- Submarine canyon, any of a class of narrow steep-sided valleys that cut into continental slopes and continental rises of the oceans.
- Submarine canyons originate either within continental slopes or on a continental shelf.
- They are rare on continental margins that have extremely steep continental slopes or escarpments.
- Submarine canyons are so called because they resemble canyons made by rivers on land.
- For years the origin of submarine canyons has been the subject of much debate among investigators.
- Various ideas have been proposed, but prevailing theory favours sub-aerial erosion as the starting point for a good number of undersea canyons.
- Such erosion is thought to have begun with the lowering of sea level during the glaciations of the Pleistocene Epoch (about 2,600,000 to 11,700 years ago).
- It is perceived, however, that sub – aerial erosion alone could scarcely have excavated deep canyons that extend down to the seafloor.
- Evidence seems to suggest that the principal agents responsible for the formation of submarine canyons are marine processes, most notably the erosion and transportation of sediments by turbidity currents activated by the slumping of unconsolidated rock material near the heads of the canyons.