Definitions

canaille

Cliff

[klif]

In geography and geology, a cliff is a significant vertical, or near vertical, rock exposure. Cliffs are formed as erosion landforms due to the processes of erosion and weathering that produce them. Cliffs are common on coasts, in mountainous areas, escarpments and along rivers. Cliffs are usually formed by rock that is resistant to erosion and weathering. Sedimentary rocks most likely to form sandstone, limestone, chalk, and dolomite. Igneous rocks, such as granite and basalt also often form cliffs.

An escarpment (or scarp) is a type of cliff, formed by the movement of a geologic fault, or a landslide.

Most cliffs have some form of scree slope at their base. In arid areas or under high cliffs, these are generally exposed jumbles of fallen rock. In areas of higher moisture, a soil slope may obscure the talus.

Many cliffs also feature tributary waterfalls or rock shelters. Sometimes a cliff peters out at the end of a ridge, with tea tables or other types of rock columns remaining.

Given that a cliff need not be exactly vertical, there can be ambiguity about whether a given slope is a cliff or not, and also about how much of a certain slope to count as a cliff. (For example, given a truly vertical rock wall above a very steep slope, one could count only the rock wall, or the combination.) This makes listings of cliffs an inherently uncertain endeavor.

The highest cliff (rock wall, mountain face) in the world, is Nanga Parbat's Rupal Flank in the Himalayas, that rises 4600 meters above its base.

According to some sources, the highest cliff in the world, about 1,340 m high, is the east face of Great Trango in the Karakoram mountains of northern Pakistan. (This uses a fairly stringent notion of cliff, as the 1,340 m figure refers to a nearly vertical headwall; adding in a very steep approach brings the total height to over 1,600 m.) The highest sea cliffs, 1,010 m high, are located at Kalaupapa, Hawaii. (This uses a less stringent definition, as the average slope of these cliffs is about 1.7, corresponding to an angle of 60 degrees.)

Considering a truly vertical drop, Mount Thor on Baffin Island in Arctic Canada is often considered the highest at 1,370 m (4,500 ft) high in total (the top 480 m (1,600 ft) is overhanging), and is said to give it the longest purely vertical drop on Earth at 1,250 m (4,100 ft). There is some doubt as to whether this height is exceeded by other cliffs on Baffin Island or in Greenland, however.

The Ordnance Survey distinguish between cliffs (continuous line along the top edge with projections down the face) and outcrops (continuous lines along lower edge).

Large and famous cliffs

The highest cliff in the solar system may be Verona Rupes, an approximately 20 km (12 mile) high fault scarp on Miranda, a moon of Uranus. The following is an incomplete list of cliffs of the world. (see also Cliffs)

Asia

Above Land

Europe

Above Sea

Above Land

North America

Several big granite faces in the Arctic regions vie for the title of 'highest purely vertical drop on Earth', but reliable measurements are not always available. The possible contenders include (measurements are approximate):

  • Mount Thor, Baffin Island, Canada; 1,370 m (4,500 ft) total; top 480 m (1,600 ft) is overhanging. This is commonly regarded as being the largest purely vertical drop on Earth at 1,250 m (4,100 ft).
  • The sheer north face of Polar Sun Spire, in the Sam Ford fjord of Baffin Island, has been reported as exceeding Mount Thor's west face in height .
  • Ketil's west face in Tasermiut, Greenland has been reported as 1,400 m - 1,450 m high, (although some doubt has been cast on this).

Other notable cliffs include:

South America

Africa

Above Sea

Above Land

Oceania

Above Sea

References

Search another word or see canailleon Dictionary | Thesaurus |Spanish
Copyright © 2014 Dictionary.com, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature