Just like river valleys on land, are V-shaped and formed through the process of erosion. They are believed to be created when ocean levels fall and the continental slope becomes exposed.

submarine canyons

Explanation:

Erosion can be defined as a geological process which typically involves the wearing out of earthen (soil) materials and the transportation of these materials by natural forces like water, wind, etc. Soil erosion is greatest when the soil is steep.

The steepness of a body such as river or stream refers to the downward slope or gradient of the body of water.

Generally, the steepness of a body affects the rate at which other materials would flow or move around. Thus, the steeper a river or stream, the greater would be its rate of erosion.

Just like river valleys on land, submarine canyons have a V-shape and are typically formed as a result of an erosion on a land surface or area.

Hence, they are considered to be created when there is a fall in ocean levels and the continental slope becomes exposed.