Coastal and Oceanic Landform ( 49.Submarine Canyon )

                                                                                                                                         Back to Coastal and Oceanic Landform 

• It  is a steep-sided valley.

• That cut into the sea floor of the continental slope.

• It extending to the continental shelf.

• Found at large rivers.

• Canyons cutting the continental slopes.

• Depths greater than 2 km below sea level.

• They continue as submarine channels.

• It extend for 100 of km.

The Congo Canyon

• Common submarine canyons ; 

                                            steep slopes  found on active margins.
                                            gentler slopes found on passive margins.

• The walls are generally very steep (near vertical).

• The walls are subject to erosion by bioerosion / slumping.

• Canyons present today were carved during glacial times.

• The major mechanism to be turbidity currents &  underwater landslides.

• Turbidity currents are dense.

• Slope failures landslides are;

                  1. Mass wasting =  -Slower and smaller action of material moving downhill.

                                                        -The effects of ;

                                                                                    bioerosion

                                                                                    burrowing

                                                                                    ingestion 

                                                       -Defecation of sediment performed by organisms.

                 2. Slumping   =  - Rotational movement of masses on a hillside,Landslides, / slides.

                                                 - Comprise  detachment &  displacement of sediment masses.

                3.Submarine =  - Sea  bed  cut off from the larger ocean.

                                                 - The sea normally repleted by contact.

                                                 - Inflow from the ocean.

• Avilés Canyon = The deepest submarine canyon.

                                           Up to 4,750 m from the slope.
                                           Southern Bay of Biscay, NE Atlantic,Spain.

• Congo Canyon = The largest river canyon.

                                           Extending from the Congo River.
                                          800 km long.
                                          1,200 m deep.

• Zhemchug Canyon = The largest submarine canyon.

                                                        Located on he Bering sea.

• Amazon Canyon,Amazon River

• Hudson Canyon,  Hudson River

• Ganges Canyon,Ganges

• Indus Canyon,Indus River

• Monterey Canyon, off the coast of central California

• Bering Canyon, Bering Sea

• Kaikoura Canyon, Offshore from the Kaikoura Peninsula, New Zealand