A canyon is a steep gorge with very high sides and a minimal valley floor. Canyons are generally larger and deeper than ravines, a related geological formation, and they are narrower and steeper than valleys. Canyons can be found all over the world, from the peaks of the Himalayas to the bottom of the oceans, and they are quite diverse, varying widely in terms of width, depth, and length. One of the most notable and large canyons in the world is the Grand Canyon, which stretches across the American Southwest.
Canyons form through processes of erosion, although in a few instances they can be caused by the movement of tectonic plates. A canyon starts out as a riverbed, and over centuries of time, the river cuts more and more deeply into the rock, creating a deep gorge. As the canyon grows deeper, the rate of erosion tends to be accelerated, as it acts as a drainage point for a watershed, encouraging the flow of even more water. The exposure of the canyon walls also creates a surface for the wind and other elements to eat away at, deepening the canyon even further.
One of the defining characteristics of a canyon is stepped walls, which are caused by rock strata of varying thicknesses and densities. As softer, more crumbly rocks are worn away, harder rocks remain, creating clear layers in the canyon walls which can be examined to learn more about the geology of the area. Most canyons also host the original waterway which led to the formation of the canyon in the first place, and some act as a form of habitat for plants and wildlife in the area.
The sport of traveling through canyons is known as canyoning. Canyoners use a wide variety of techniques to travel, ranging from kayaks to horses. This sport can offer a fascinating glimpse into the natural environment of a region, as people may pass through several zones as they explore a canyon. It can also be dangerous; canyons are notorious for their flash floods, and their walls can also be very fragile, potentially creating slides of rock and dirt which can injure or kill people.
When traveling in and around canyons, it is a good idea to be safety conscious. People should stand will back from the rim of a canyon, as canyon rims are often undercut and subject to severe erosion. Shifting weight near the edge of a canyon can cause the rim to crumble, causing someone to fall and be badly injured. It is also important to be aware of weather conditions when traveling in a canyon, as a flash flood can be brought on by surprisingly light rainfall.