Cliff

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File:Trango Towers 2.jpg
The Trango Towers in Pakistan. Their vertical faces are the world's tallest cliffs. Trango Tower center; Trango Monk center left; Trango II far left; Great Trango right.
File:Troll Wall in shadow.jpg
Europe's tallest cliff, Troll wall in Norway. A famous BASE location for jumpers from around the world.

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 are 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.

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

File:Northern Areas 40.jpg
The far southwestern aspect of Nanga Parbat's Rupal face, highest cliff (rock wall/mountain face) in the world. The steepest part of the face lies 2km to the northeast.

Large and famous cliffs

File:TalusConesIsfjorden.jpg
Cliffs along the north shore of Isfjord, Svalbard, Norway.
File:Miranda scarp.jpg
Close-up view of Verona Rupes, a 20 km high fault scarp on Miranda, a moon of Uranus.[1]

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.

Some of the largest cliffs on Earth are found underwater. For example, an 8000-meter drop over a 4250-meter span can be found at a ridge sitting inside the Kermadec Trench.

The highest cliff (rock wall, mountain face) in the world, is Nanga Parbat's Rupal Flank, which rises approximately 4600 meters, or 15,000 feet, above its base. According to other sources, the highest cliff in the world, about 1340 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 1340 m figure refers to a nearly vertical headwall; adding in a very steep approach brings the total height to over 1600 m.

The location of the world's highest sea cliffs depends also on the definition of 'cliff' that is used. The Guinness record books claim it is Kalaupapa, Hawaii,[2] at 1010 m high. Another contender is the north face of Mitre Peak, which drops 1683 meters to Milford Sound, New Zealand.[3] These are subject to a less stringent definition, as the average slope of these cliffs at Kaulapapa is about 1.7, corresponding to an angle of 60 degrees, and Mitre Peak is similar. A more vertical drop into the sea can be found at Maujit Qaqarssuasia (also known as the 'Thumbnail') which is situated in the Torssakutak fjord area at the very tip of South Greenland and drops 1560m near-vertically.[4][5]

Considering a truly vertical drop, Mount Thor on Baffin Island in Arctic Canada is often considered the highest at 1370 m (4500 ft) high in total (the top 480 m (1600 ft) is overhanging), and is said to give it the longest purely vertical drop on Earth at 1250 m (4,100 ft). However, cliffs on Baffin Island, such as Polar Sun Spire, or others in remote areas of Greenland may be higher.

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.

Asia

Above Sea

Above Land

Europe

Above Sea

Above Land

North America

File:Mount Thor.jpg
Mount Thor, Baffin Island, Nunavut, Canada, commonly regarded as the highest purely vertical drop on Earth
File:Yosemite El Capitan.jpg
Southwest face of El Capitan from Yosemite Valley
File:NotchPeakSunset.JPG
The face of Notch Peak at sunset

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; 1370 m (4500 ft) total; top 480 m (1600 ft) is overhanging. This is commonly regarded as being the largest purely vertical drop on Earth [cn] at 1250 m (4100 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.[7]
  • Ketil's west face in Tasermiut, Greenland (also known as God's Thumbnail), has been reported as 1400 m – 1450 m high, (although some doubt has been cast on this).[8][9]

Other notable cliffs include:

South America

Africa

Above Sea

Above Land

  • Drakensberg Amphitheatre, South Africa 1,200 m (3,900 ft) above base, 5 km (3.1 mi) long. The Tugela Falls, the world's second tallest waterfall, falls 948 m (3,110 ft) over the edge of the cliff face.
  • Mount Meru, Tanzania Caldera Cliffs, 1,500 m (4,900 ft)
  • Klein Winterhoek, Western Cape, South Africa, 1,220 m (4,000 ft) above base.
  • Wall of Fire, Swartberg, Western Cape, South Africa 700 m (2,300 ft) cliff composed of vertically displaced quartzite
  • Tsaranoro, Madagascar, 700 m (2,300 ft) above base
  • Karambony, Madagascar, 380 m (1,200 ft) above base.
  • Innumerable peaks in the Drakensberg mountains of South Africa are spectacular cliff formations. The Drakensberg Range is regarded, together with Ethiopia's Simien Mountains, as one of the two finest erosional mountain ranges on Earth. Because of their near-unique geological formation, the range has an extraordinarily high percentage of cliff faces making up its length, particularly along the highest portion of the range. This portion of the range is virtually uninterrupted cliff faces, ranging from 600 m (2,000 ft) to 1,200 m (3,900 ft) in height for almost 250 km (160 mi). Of all, the "Drakensberg Amphitheatre" (mentioned above) is probably the most impressive individual formation. Other notable cliffs include the Trojan Wall, Cleft Peak, Injisuthi Triplets, Cathedral Peak, Monk's Cowl, Mnweni Buttress, etc. The cliff faces of the Blyde River Canyon, technically still part of the Drakensberg, may be over 800 m (2,600 ft), with the main face of the Swadini Buttress approximately 1,000 m (3,300 ft) tall.

Oceania

Above Sea

As habitat determinants

Cliff landforms provide unique habitat niches to a variety of plants and animals, whose preferences and needs are suited by the vertical geometry of this landform type. For example, a number of birds have decided affinities for choosing cliff locations for nesting,[11] often driven by the defensibility of these locations as well as absence of certain predators.

See also

References

  1. "Natural world: the solar system: highest cliffs". Guinness World Records. Archived from the original on 2006-05-21. http://web.archive.org/web/20060521223224/http://www.guinnessworldrecords.com/content_pages/record.asp?recordid=54819. Retrieved 2006-08-05. 
  2. "Highest Cliffs". Guinness World Records. Archived from the original on 2005-11-27. http://web.archive.org/web/20051127032740/http://www.guinnessworldrecords.com/content_pages/record.asp?recordid=47602. Retrieved 2006-05-02. 
  3. The Encyclopedia of Tourism and Recreation in Marine Environments By Michael Lück. Google Books. http://books.google.co.uk/books?id=Yuc2Aro6ukkC&pg=PA177&lpg=PA176&ots=ZM97kgqt8X. Retrieved 2009-08-01. 
  4. "Planet Fear". http://www.planetfear.co.uk/articles/Greenland_New_Route_on_Thumbnail_926.html. Retrieved 2009-08-04. 
  5. "TS2 satellites (Expedition Sponsor)". http://www.ts2.pl/en/News/1/56. Retrieved 2009-08-04. 
  6. http://www.southwestcoastpath.com/main/sections/index.cfm?fsa=dspSectionDetail&w_id=147
  7. "Polar Sun Spire". SummitPost.Org. http://www.summitpost.org/mountain/rock/152417/polar-sun-spire.html. Retrieved 2008-07-31. 
  8. "Climbing in Tasermiut". bigwall.dk. http://www.bigwall.dk/galleri/klatring/tasermiu/pages-uk/uk05keti.htm. Retrieved 2008-09-02. 
  9. "The American Alpine Journal 1986". http://www.americanalpineclub.org/AAJO/pdfs/1986/175_canada_greenland_aaj1986.pdf. Retrieved 2008-09-02. [dead link]
  10. "Geology Fieldnotes". National Park Service. http://www.nature.nps.gov/geology/parks/zion/index.cfm. Retrieved 2010-11-28. 
  11. C.Michael Hogan. 2010. Abiotic factor. Encyclopedia of Earth. eds Emily Monosson and C. Cleveland. National Council for Science and the Environment. Washington DC
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