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24-540: Some towns are located at the foot of the Tagant Plateau's slopes, which form cliffs in some places. Among these areas are Tichit , Moudjéria and Rachid . Tidjikdja lies on the Tagant itself. The Assaba Massif , where Late Ordovician glacial formations have been identified, is a southward prolongation of the Tagant Plateau. The Aoukar , the dry basin of a former lake lies beyond the southern escarpments of

48-402: A cliff peters out at the end of a ridge, with mushroom rocks or other types of rock columns remaining. Coastal erosion may lead to the formation of sea cliffs along a receding coastline. The British Ordnance Survey distinguishes between around most cliffs (continuous line along the topper edge with projections down the face) and outcrops (continuous lines along lower edge). Cliff comes from

72-542: A moon of Uranus. The following is an incomplete list of cliffs of the world. Above Sea Above Land Several big granite faces in the Arctic region vie for the title of 'highest 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 (1600 ft)

96-530: 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, often driven by the defensibility of these locations as well as absence of certain predators. Humans have also inhabited cliff dwellings . The population of the rare Borderea chouardii , during 2012, existed only on two cliff habitats within western Europe. Kermadec Trench The Kermadec Trench

120-406: 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 just the rock wall or the combination. Listings of cliffs are thus inherently uncertain. Some of the largest cliffs on Earth are found underwater. For example, an 8,000 m drop over a 4,250 m span can be found at a ridge sitting inside

144-630: Is a linear ocean trench in the south Pacific Ocean . It stretches about 1,000 km (620 mi) from the Louisville Seamount Chain in the north (26°S) to the Hikurangi Plateau in the south (37°S), north-east of New Zealand 's North Island . Together with the Tonga Trench to the north, it forms the 2,000 km (1,200 mi)-long, near-linear Kermadec-Tonga subduction system , which began to evolve in

168-472: Is a type of cliff formed by the movement of a geologic fault , a landslide, or sometimes by rock slides or falling rocks which change the differential erosion of the rock layers. Most cliffs have some form of scree slope at their base. In arid areas or under high cliffs, they 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

192-534: 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 Torssukátak fjord area at the very tip of South Greenland and drops 1,560 m near-vertically. Considering a truly vertical drop, Mount Thor on Baffin Island in Arctic Canada is often considered

216-516: Is almost perfectly straight and its simple geometry is the result of the uniformity of the subducting sea-floor. This sea-floor formed at the extinct Osbourn Trough , located just north of the Louisville Seamount Chain . Abyssal hills on the subducting sea-floor are oriented perpendicular to the old spreading centre and the sea-floor is 72–80 Ma near the Louisville seamounts at the northern end and more than 100 Ma near Hikurangi Plateau at

240-597: Is currently subducting under the southern part of the Kermadec Arc but most of it has already been subducted. The LIP-arc collision occurred 250 km (160 mi) north of its present location, but oblique plate convergence has migrated the subducted plateau southward. In 2012, deep sea researchers discovered individuals of a species of giant amphipod at the trench's lowest depths. Unlike most amphipods , which are approximately 2.5 cm (1 inch) long, this species reaches up to 34 cm (13 inches) in length, and

264-518: Is milky-white. The second-deepest fish, the hadal snailfish Notoliparis kermadecensis , is endemic to the trench and occupies a very limited depth range, 6,472 to 7,561 m (21,234 to 24,806 ft). A species of pearlfish , Echiodon neotes , has been caught in the Kermadec Trench at a depth of 8,200–8,300 m (26,900–27,200 ft). All other known pearlfishes live in the range 1,800–2,000 m (5,900–6,600 ft) and

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288-505: Is overhanging. This is commonly regarded as being the largest vertical drop on Earth [1] ot:leapyear at 1,250 m (4,100 ft). of Baffin Island , rises 4,300 ft above the flat frozen fjord, although the lower portion of the face breaks from the vertical wall with a series of ledges and buttresses. Other notable cliffs include: Above Sea Above Land Above Sea Above Land Submarine Above Sea Above Land Cliff landforms provide unique habitat niches to

312-584: The Eocene when the Pacific Plate started to subduct beneath the Australian Plate . Convergence rates along this subduction system are among the fastest on Earth, 80 mm (3.1 in)/yr in the north and 45 mm (1.8 in)/yr in the south. The Kermadec Trench is one of Earth's deepest oceanic trenches, reaching a depth of 10,047 metres (32,963 ft). Formed by the subduction of

336-581: The Kermadec Trench . 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 of two stacked pillars; adding in a very steep approach brings the total drop from the East Face precipice to

360-607: The Pacific Plate under the Indo-Australian Plate , it runs parallel with and to the east of the Kermadec Ridge and island arc . The Tonga Trench marks the continuation of subduction to the north. The Kermadec Trench has a southern continuation in the turbidite -filled Hikurangi Trough , but a series of seamounts on the Australian Plate act as a dam and prevents this turbidity from reaching

384-515: The Old English word clif of essentially the same meaning, cognate with Dutch, Low German, and Old Norse klif 'cliff'. These may in turn all be from a Romance loanword into Primitive Germanic that has its origins in the Latin forms clivus / clevus ("slope" or "hillside"). Given that a cliff does not need to be exactly vertical, there can be ambiguity about whether a given slope

408-607: The Tagant Plateau. Beginning in mid-17th century, migrants from the Adrar Plateau region moved in and displaced the native population of the Tagant Plateau, the Toucouleur people , who now inhabit Futa Toro along the Senegal river . The Tartega Gueltas oasis is one of the few wetlands in the region where there were still desert crocodiles in 1976. The population was reported to be extinct in 1996, but as of 2011

432-543: 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 vertical drop on Earth at 1,250 m (4,100 ft). However, other cliffs on Baffin Island, such as Polar Sun Spire in the Sam Ford Fjord , 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 mi) high fault scarp on Miranda ,

456-432: The nearby Dunge Glacier to nearly 2,000 m. The location of the world's highest sea cliffs depends also on the definition of 'cliff' that is used. Guinness World Records states it is Kalaupapa, Hawaii , at 1,010 m high. Another contender is the north face of Mitre Peak , which drops 1,683 m to Milford Sound , New Zealand. These are subject to a less stringent definition, as the average slope of these cliffs at Kaulapapa

480-632: The presence of E. neotes at this depth remains unexplained. In May 2014, the Nereus , an unmanned research submarine operated by the Woods Hole Oceanographic Institution (WHOI), imploded due to high pressure at a depth of 9,990 metres while exploring the Kermadec Trench. In December 2022, a research team from the Chinese Academy of Sciences and National Institute of Water and Atmospheric Research reached

504-457: The processes of weathering and erosion , with the effect of gravity . Cliffs are common on coasts, in mountainous areas, escarpments and along rivers. Cliffs are usually composed of rock that is resistant to weathering and erosion. The sedimentary rocks that are most likely to form cliffs include sandstone , limestone , chalk , and dolomite . Igneous rocks such as granite and basalt also often form cliffs. An escarpment (or scarp)

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528-512: The sediment-starved Kermadec Trench. Debris from a larger subducted seamount probably dammed the trench from 2 Ma to 0.5 Ma and similar events probably redirected sediments in similar ways before that. Two oceanic plates meet at the Kermadec Trench which is located far from any larger landmass. Because of this, the Pacific Plate as well as the trench itself is only covered by c. 200 m (660 ft) of sediments. The trench

552-570: The southern end. There are no seamounts on the sea-floor near the Kermadec Trench except one sitting on the trench slope at 31°30′S 176°27′W  /  31.50°S 176.45°W  / -31.50; -176.45 which has been dated to 54.8±1.9 Ma. The Hikurangi Plateau formed part of the Ontong-Java - Manihiki - Hikurangi large igneous province (LIP) during the Ontong Java Event 120  Ma . The Manihiki Plateau

576-505: Was still present, particularly in the Lake Gabou area. 18°28′09″N 11°03′08″W  /  18.4692°N 11.0522°W  / 18.4692; -11.0522 This Mauritania location article is a stub . You can help Misplaced Pages by expanding it . Cliff In geography and geology, a cliff or rock face is an area of rock which has a general angle defined by the vertical, or nearly vertical. Cliffs are formed by

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