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Wikipedia

Dune

A dune is a landform composed of wind- or water-driven sand. It typically takes the form of a mound, ridge, or hill.[1] An area with dunes is called a dune system[2][3][4][5] or a dune complex.[6] A large dune complex is called a dune field,[7] while broad, flat regions covered with wind-swept sand or dunes with little or no vegetation are called ergs or sand seas.[8][9][10] Dunes occur in different shapes and sizes, but most kinds of dunes are longer on the stoss (upflow) side, where the sand is pushed up the dune, and have a shorter slip face in the lee side.[11] The valley or trough between dunes is called a dune slack.[12]

Coastal dunes in De Panne, Belgium
Coastal dunes at the Yyteri Beach in Pori, Finland
Sand dunes of the Empty Quarter to the east of Liwa Oasis, United Arab Emirates

Dunes are most common in desert environments, where the lack of moisture hinders the growth of vegetation that would otherwise interfere with the development of dunes. However, sand deposits are not restricted to deserts, and dunes are also found along sea shores, along streams in semiarid climates, in areas of glacial outwash, and in other areas where poorly cemented sandstone bedrock disintegrates to produce an ample supply of loose sand.[13] Subaqueous dunes can form from the action of water flow (fluvial processes) on sand or gravel beds of rivers, estuaries, and the sea-bed.[14][15]

Some coastal areas have one or more sets of dunes running parallel to the shoreline directly inland from the beach. In most cases, the dunes are important in protecting the land against potential ravages by storm waves from the sea.[16] Artificial dunes are sometimes constructed to protect coastal areas.[17][18] The dynamic action of wind and water can sometimes cause dunes to drift, which can have serious consequences. For example, the town of Eucla, Western Australia, had to be relocated in the 1890s because of dune drift.[19]

The modern word "dune" came into English from French around 1790,[20] which in turn came from Middle Dutch dūne.[14]

Formation

 
Sand hitting sand is more likely to stick; sand hitting a more coherent surface is more likely to bounce (saltation). This exacerbating feedback loop helps sand accumulate into dunes.

A universally precise distinction does not exist between ripples, dunes, and a draa,[21] which are all deposits of the same type of materials. Dunes are generally defined as greater than 7 cm tall and may have ripples, while ripples are deposits that are less than 3 cm tall.[22] A draa is a very large eolian landform, with a length of several kilometers and a height of tens to hundreds of meters, and which may have superimposed dunes.[23]

Dunes are made of sand-sized particles, and may consist of quartz, calcium carbonate, snow, gypsum, or other materials. The upwind/upstream/upcurrent side of the dune is called the stoss side; the downflow side is called the lee side. Sand is pushed (creep) or bounces (saltation) up the stoss side, and slides down the lee side. A side of a dune that the sand has slid down is called a slip face (or slipface).

The Bagnold formula gives the speed at which particles can be transported.

Aeolian dunes

Aeolian dune shapes

Five basic dune types are recognized: crescentic, linear, star, dome, and parabolic. Dune areas may occur in three forms: simple (isolated dunes of basic type), compound (larger dunes on which smaller dunes of same type form), and complex (combinations of different types).[24]

Barchan or crescentic

 
Isolated barchan dunes on the surface of Mars. Dominant wind direction would be from left to right.

Barchan dunes are crescent-shaped mounds which are generally wider than they are long. The lee-side slipfaces are on the concave sides of the dunes. These dunes form under winds that blow consistently from one direction (unimodal winds). They form separate crescents when the sand supply is comparatively small. When the sand supply is greater, they may merge into barchanoid ridges, and then transverse dunes (see below).

Some types of crescentic dunes move more quickly over desert surfaces than any other type of dune. A group of dunes moved more than 100 metres per year between 1954 and 1959 in China's Ningxia Province, and similar speeds have been recorded in the Western Desert of Egypt. The largest crescentic dunes on Earth, with mean crest-to-crest widths of more than three kilometres, are in China's Taklamakan Desert.[24]

See lunettes and parabolic dunes, below, for dunes similar to crescent-shaped ones.

Transverse dunes

Abundant barchan dunes may merge into barchanoid ridges, which then grade into linear (or slightly sinuous) transverse dunes, so called because they lie transverse, or across, the wind direction, with the wind blowing perpendicular to the ridge crest.[25]

Seif or longitudinal dunes

Seif dunes are linear (or slightly sinuous) dunes with two slip faces.[25] The two slip faces make them sharp-crested. They are called seif dunes after the Arabic word for "sword". They may be more than 160 kilometres (100 miles) long, and thus easily visible in satellite images (see illustrations).

Seif dunes are associated with bidirectional winds. The long axes and ridges of these dunes extend along the resultant direction of sand movement (hence the name "longitudinal").[26] Some linear dunes merge to form Y-shaped compound dunes.[24]

Formation is debated. Ralph Bagnold, in The Physics of Blown Sand and Desert Dunes, suggested that some seif dunes form when a barchan dune moves into a bidirectional wind regime, and one arm or wing of the crescent elongates. Others suggest that seif dunes are formed by vortices in a unidirectional wind.[25] In the sheltered troughs between highly developed seif dunes, barchans may be formed, because the wind is constrained to be unidirectional by the dunes.

Seif dunes are common in the Sahara. They range up to 300 m (980 ft) in height and 300 km (190 mi) in length. In the southern third of the Arabian Peninsula, a vast erg, called the Rub' al Khali or Empty Quarter, contains seif dunes that stretch for almost 200 km (120 mi) and reach heights of over 300 m (980 ft).

Linear loess hills known as pahas are superficially similar. These hills appear to have been formed during the last ice age under permafrost conditions dominated by sparse tundra vegetation.

Star

Radially symmetrical, star dunes are pyramidal sand mounds with slipfaces on three or more arms that radiate from the high center of the mound. They tend to accumulate in areas with multidirectional wind regimes. Star dunes grow upward rather than laterally. They dominate the Grand Erg Oriental of the Sahara. In other deserts, they occur around the margins of the sand seas, particularly near topographic barriers. In the southeast Badain Jaran Desert of China, the star dunes are up to 500 metres tall and may be the tallest dunes on Earth.

Dome

Oval or circular mounds that generally lack a slipface. Dome dunes are rare and occur at the far upwind margins of sand seas.

Lunettes

Fixed crescentic dunes that form on the leeward margins of playas and river valleys in arid and semiarid regions in response to the direction (s) of prevailing winds, are known as lunettes, source-bordering dunes, bourrelets and clay dunes. They may be composed of clay, silt, sand, or gypsum, eroded from the basin floor or shore, transported up the concave side of the dune, and deposited on the convex side. Examples in Australia are up to 6.5 km long, 1 km wide, and up to 50 metres high. They also occur in southern and West Africa, and in parts of the western United States, especially Texas.[27]

Parabolic

 
Schematic of coastal parabolic dunes

U-shaped mounds of sand with convex noses trailed by elongated arms are parabolic dunes. These dunes are formed from blowout dunes where the erosion of vegetated sand leads to a U-shaped depression. The elongated arms are held in place by vegetation; the largest arm known on Earth reaches 12 km. Sometimes these dunes are called U-shaped, blowout, or hairpin dunes, and they are well known in coastal deserts. Unlike crescent shaped dunes, their crests point upwind. The bulk of the sand in the dune migrates forward.

In plan view, these are U-shaped or V-shaped mounds of well-sorted, very fine to medium sand with elongated arms that extend upwind behind the central part of the dune. There are slipfaces that often occur on the outer side of the nose and on the outer slopes of the arms.

These dunes often occur in semiarid areas where the precipitation is retained in the lower parts of the dune and underlying soils. The stability of the dunes was once attributed to the vegetative cover but recent research has pointed to water as the main source of parabolic dune stability. The vegetation that covers them—grasses, shrubs, and trees—help anchor the trailing arms. In inland deserts, parabolic dunes commonly originate and extend downwind from blowouts in sand sheets only partly anchored by vegetation. They can also originate from beach sands and extend inland into vegetated areas in coastal zones and on shores of large lakes.

Most parabolic dunes do not reach heights higher than a few tens of metres except at their nose, where vegetation stops or slows the advance of accumulating sand.

Simple parabolic dunes have only one set of arms that trail upwind, behind the leading nose. Compound parabolic dunes are coalesced features with several sets of trailing arms. Complex parabolic dunes include subsidiary superposed or coalesced forms, usually of barchanoid or linear shapes.

Parabolic dunes, like crescent dunes, occur in areas where very strong winds are mostly unidirectional. Although these dunes are found in areas now characterized by variable wind speeds, the effective winds associated with the growth and migration of both the parabolic and crescent dunes probably are the most consistent in wind direction.

The grain size for these well-sorted, very fine to medium sands is about 0.06 to 0.5 mm. Parabolic dunes have loose sand and steep slopes only on their outer flanks. The inner slopes are mostly well packed and anchored by vegetation, as are the corridors between individual dunes. Because all dune arms are oriented in the same direction, and, the inter-dune corridors are generally swept clear of loose sand, the corridors can usually be traversed in between the trailing arms of the dune. However to cross straight over the dune by going over the trailing arms, can be very difficult. Also, traversing the nose is very difficult as well because the nose is usually made up of loose sand without much if any vegetation.

A type of extensive parabolic dune that lacks discernible slipfaces and has mostly coarse grained sand is known as a zibar.[28] The term zibar comes from the Arabic word to describe "rolling transverse ridges ... with a hard surface".[29] The dunes are small, have low relief, and can be found in many places across the planet from Wyoming (United States) to Saudi Arabia to Australia.[30] Spacing between zibars ranges from 50 to 400 metres and they don't become more than 10 metres high.[31] The dunes form at about ninety degrees to the prevailing wind which blows away the small, fine-grained sand leaving behind the coarser grained sand to form the crest.[32]

Reversing dunes

 
Reversing dune showing short minor slipface atop the major stoss (upwind) face

Occurring wherever winds periodically reverse direction, reversing dunes are varieties of any of the above shapes. These dunes typically have major and minor slipfaces oriented in opposite directions. The minor slipfaces are usually temporary, as they appear after a reverse wind and are generally destroyed when the wind next blows in the dominant direction.[25]

Draas

 
Dune Nine in Sossusvlei, Namibia, is over 300m high.

Draas are very large-scale dune bedforms; they may be tens or a few hundreds of metres in height, kilometres wide, and hundreds of kilometres in length.[25] After a draa has reached a certain size, it generally develops superimposed dune forms.[33] They are thought to be more ancient and slower-moving than smaller dunes,[25] and to form by vertical growth of existing dunes. Draas are widespread in sand seas and are well-represented in the geological record.[33]

Dune complexity

All these dune shapes may occur in three forms: simple (isolated dunes of basic type), compound (larger dunes on which smaller dunes of same type form), and complex (combinations of different types).[24] Simple dunes are basic forms with the minimum number of slipfaces that define the geometric type. Compound dunes are large dunes on which smaller dunes of similar type and slipface orientation are superimposed. Complex dunes are combinations of two or more dune types. A crescentic dune with a star dune superimposed on its crest is the most common complex dune. Simple dunes represent a wind regime that has not changed in intensity or direction since the formation of the dune, while compound and complex dunes suggest that the intensity and direction of the wind has changed.

Dune movement

The sand mass of dunes can move either windward or leeward, depending on if the wind is making contact with the dune from below or above its apogee. If wind hits from above, the sand particles move leeward; the leeward flux of sand is greater than the windward flux. Conversely, if sand hits from below, sand particles move windward. Further, if the wind is carrying sand particles when it hits the dune, the dune's sand particles will saltate more than if the wind had hit the dune without carrying sand particles.[34]

Coastal dunes

 
Coastal dunes covered in grasses around the mouth of the Liver Å river in Denmark
Newborough Dune Rejuvenation, Wales; video of work done by Natural Resources Wales; 2015

Coastal dunes[35] form when wet sand is deposited along the coast and dries out and is blown along the beach.[36] Dunes form where the beach is wide enough to allow for the accumulation of wind-blown sand, and where prevailing onshore winds tend to blow sand inland. The three key ingredients for coastal dune formation are a large sand supply, winds to move said sand supply, and a place for the sand supply to accumulate.[37] Obstacles—for example, vegetation, pebbles and so on—tend to slow down the wind and lead to the deposition of sand grains.[38] These small "incipient dunes or "shadow dunes" tend to grow in the vertical direction if the obstacle slowing the wind can also grow vertically (i.e., vegetation). Coastal dunes expand laterally as a result of lateral growth of coastal plants via seed or rhizome.[39][40] Models of coastal dunes suggest that their final equilibrium height is related to the distance between the water line and where vegetation can grow.[41] Coastal dunes can be classified by where they develop, or begin to take shape. Dunes are commonly grouped into either the Primary Dune Group or the Secondary Dune Group.[35] Primary dunes gain most of their sand from the beach itself, while secondary dunes gain their sand from the primary dune. Along the Florida Panhandle, most dunes are considered to be foredunes or hummocks.[42][43] Different locations around the globe have dune formations unique to their given coastal profile.

Coastal sand dunes can provide privacy and/or habitats to support local flora and fauna. Animals such as sand snakes, lizards, and rodents can live in coastal sand dunes, along with insects of all types.[44] Often the vegetation of sand dunes is discussed without acknowledging the importance that coastal dunes have for animals. Further, some animals, such as foxes and feral pigs can use coastal dunes as hunting grounds to find food.[45] Birds are also known to utilize coastal dunes as nesting grounds. All these species find the coastal environment of the sand dune vital to their species' survival.

Over the course of time coastal dunes may be impacted by tropical cyclones or other intense storm activity, dependent on their location. Recent work has suggested that coastal dunes tend to evolve toward a high or low morphology depending on the growth rate of dunes relative to storm frequency.[46][47] During a storm event, dunes play a significant role in minimizing wave energy as it moves onshore. As a result, coastal dunes, especially those in the foredune area affected by a storm surge, will retreat or erode.[48] To counteract the damage from tropical activity on coastal dunes, short term post-storm efforts can be made by individual agencies through fencing to help with sand accumulation.[49]

How much a dune erodes during any storm surge is related to its location on the coastal shoreline and the profile of the beach during a particular season. In those areas with harsher winter weather, during the summer a beach tends to take on more of a convex appearance due to gentler waves, while the same beach in the winter may take on more of a concave appearance. As a result, coastal dunes can get eroded much more quickly in the winter than in the summer. The converse is true in areas with harsher summer weather.[50]

There are many threats to these coastal communities. Some coastal dunes, for example ones in San Francisco, have been completely altered by urbanization; reshaping the dune for human use. This puts native species at risk. Another danger, in California and places in the UK specifically, is the introduction of invasive species. Plant species, such as Carpobrotus edulis, were introduced from South Africa in an attempt to stabilize the dunes and provide horticultural benefits, but instead spread taking land away from native species. Ammophila arenaria, known as European beachgrass, has a similar story, though it has no horticulture benefits. It has great ground coverage and, as intended, stabilized the dunes but as an unintended side effect prevented native species from thriving in those dunes. One such example is the dune field at Point Reyes, California. There are now efforts to get rid of both of these invasive species.[51][52]

Ecological succession on coastal dunes

As a dune forms, plant succession occurs. The conditions on an embryo dune are harsh, with salt spray from the sea carried on strong winds. The dune is well drained and often dry, and composed of calcium carbonate from seashells. Rotting seaweed, brought in by storm waves adds nutrients to allow pioneer species to colonize the dune. For example, in the United Kingdom these pioneer species are often marram grass, sea wort grass and other sea grasses. These plants are well adapted to the harsh conditions of the foredune, typically having deep roots which reach the water table, root nodules that produce nitrogen compounds, and protected stoma, reducing transpiration. Also, the deep roots bind the sand together, and the dune grows into a foredune as more sand is blown over the grasses. The grasses add nitrogen to the soil, meaning other, less hardy plants can then colonize the dunes. Typically these are heather, heaths and gorses. These too are adapted to the low soil water content and have small, prickly leaves which reduce transpiration. Heather adds humus to the soil and is usually replaced by coniferous trees, which can tolerate low soil pH, caused by the accumulation and decomposition of organic matter with nitrate leaching.[53] Coniferous forests and heathland are common climax communities for sand dune systems.

Young dunes are called yellow dunes and dunes which have high humus content are called grey dunes. Leaching occurs on the dunes, washing humus into the slacks, and the slacks may be much more developed than the exposed tops of the dunes. It is usually in the slacks that more rare species are developed and there is a tendency for the dune slacks' soil to be waterlogged where only marsh plants can survive. In Europe these plants include: creeping willow, cotton grass, yellow iris, reeds, and rushes. As for vertebrates in European dunes, natterjack toads sometimes breed here.

Coastal dune floral adaptations

 
Sand dunes of Hyypänmäki in Hailuoto, Finland
Sea dune erosion at Talacre, Wales

Dune ecosystems are extremely difficult places for plants to survive. This is due to a number of pressures related to their proximity to the ocean and confinement to growth on sandy substrates. These include:

  • Little available soil moisture
  • Little available soil organic matter/nutrients/water
  • Harsh winds
  • Salt spray
  • Erosion/shifting and sometimes burial or exposure (from shifting)
  • Tidal influences

Plants have evolved many adaptations to cope with these pressures:

  • Deep taproot to reach water table (Pink Sand Verbena)
  • Shallow but extensive root systems
  • Rhizomes
  • Prostrate growth form to avoid wind/salt spray (Abronia spp., Beach Primrose)
  • Krummholz growth form (Monterrey Cypress-not a dune plant but deals with similar pressures)
  • Thickened cuticle/Succulence to reduce moisture loss and reduce salt uptake (Ambrosia/Abronia spp., Calystegia soldanella)
  • Pale leaves to reduce insolation (Artemisia/Ambrosia spp.)
  • Thorny/Spiky seeds to ensure establishment in vicinity of parent, reduces chances of being blown away or swept out to sea (Ambrosia chamissonis)

Gypsum dunes

 
Gypsum dune fields, White Sands National Park, New Mexico, United States

In deserts where large amounts of limestone mountains surround a closed basin, such as at White Sands National Park in south-central New Mexico, occasional storm runoff transports dissolved limestone and gypsum into a low-lying pan within the basin where the water evaporates, depositing the gypsum and forming crystals known as selenite. The crystals left behind by this process are eroded by the wind and deposited as vast white dune fields that resemble snow-covered landscapes. These types of dune are rare, and only form in closed arid basins that retain the highly soluble gypsum that would otherwise be washed into the sea.[54]

Nabkha dunes

A nabkha, or coppice dune, is a small dune anchored by vegetation. They usually indicate desertification or soil erosion, and serve as nesting and burrow sites for animals.

Sub-aqueous dunes

Sub-aqueous (underwater) dunes form on a bed of sand or gravel under the actions of water flow. They are ubiquitous in natural channels such as rivers and estuaries, and also form in engineered canals and pipelines.[55][56][57] Dunes move downstream as the upstream slope is eroded and the sediment deposited on the downstream or lee slope in typical bedform construction.[58] In the case of sub-aqueous barchan dunes, sediment is lost by their extremities, known as horns.[59][60]

These dunes most often form as a continuous 'train' of dunes, showing remarkable similarity in wavelength and height. The shape of a dune gives information about its formation environment.[61] For instance, rivers produce asymmetrical ripples, with the steeper slip face facing downstream. Ripple marks preserved in sedimentary strata in the geological record can be used to determine the direction of current flow, and thus an indication of the source of the sediments.

Dunes on the bed of a channel significantly increase flow resistance, their presence and growth playing a major part in river flooding.

Lithified dunes

 
Cross-bedding in lithified aeolian sand dunes preserved as sandstone in Zion National Park, Utah

A lithified (consolidated) sand dune is a type of sandstone that is formed when a marine or aeolian sand dune becomes compacted and hardened. Once in this form, water passing through the rock can carry and deposit minerals, which can alter the color of the rock. Cross-bedded layers of stacks of lithified dunes can produce the cross-hatching patterns, such as those seen in Zion National Park in the western United States.

A slang term, used in the southwest US, for consolidated and hardened sand dunes is "slickrock", a name that was introduced by pioneers of the Old West because their steel-rimmed wagon wheels could not gain traction on the rock.[citation needed]

Desertification

Sand dunes can have a negative impact on humans when they encroach on human habitats. Sand dunes move via a few different means, all of them helped along by wind. One way that dunes can move is by saltation, where sand particles skip along the ground like a bouncing ball. When these skipping particles land, they may knock into other particles and cause them to move as well, in a process known as creep. With slightly stronger winds, particles collide in mid-air, causing sheet flows. In a major dust storm, dunes may move tens of metres through such sheet flows. Also as in the case of snow, sand avalanches, falling down the slipface of the dunes—that face away from the winds—also move the dunes forward.

Sand threatens buildings and crops in Africa, the Middle East, and China. Drenching sand dunes with oil stops their migration, but this approach uses a valuable resource and is quite destructive to the dunes' animal habitats. Sand fences might also slow their movement to a crawl, but geologists are still analyzing results for the optimum fence designs.[62] Preventing sand dunes from overwhelming towns, villages, and agricultural areas has become a priority for the United Nations Environment Programme. Planting dunes with vegetation also helps to stabilise them.

Conservation

 
Sand blowing off a crest in the Kelso Dunes of the Mojave Desert, California, USA

Dune habitats provide niches for highly specialized plants and animals, including numerous rare species and some endangered species. Due to widespread human population expansion, dunes face destruction through land development and recreational usages, as well as alteration to prevent the encroachment of sand onto inhabited areas. Some countries, notably the United States, Australia, Canada, New Zealand, the United Kingdom, Netherlands, and Sri Lanka have developed significant programs of dune protection through the use of sand dune stabilization. In the U.K., a Biodiversity Action Plan has been developed to assess dunes loss and to prevent future dunes destruction.

Examples

Africa

 
A dune in Sossusvlei, in the greater Namib-Naukluft National Park, Namibia. Note the trees being engulfed for scale.
 
Camelthorn trees and bushes scattered on dunes in the Kalahari Desert in Namibia (2017)
 
Sand dune in the Libyan Desert near Dakhla Oasis at sunset.
 
Wind ripples on crescent-shaped sand dunes (barchans) in southwest Afghanistan (Sistan)

Asia

 
Fronting the Mediterranean Sea in Oliva, Valencian Community, Spain

Europe

 
50 m (160 ft) tall dune in Salir do Porto, Portugal
 
Sand dunes of Lemnos, Greece

North America

 
Cadiz Dunes Wilderness, California

South America

 
White sand dunes in the Lençóis Maranhenses National Park, Maranhão, Brazil
 
Coastal dunes at Stockton Beach in the City of Newcastle

Oceania

World's highest dunes

Note: This table is partially based on estimates and incomplete information.
Dune Height from Base feet/metres Height from Sea Level feet/metres Location Notes
Duna Federico Kirbus ≈4,035/1,230 ≈9,334/2,845 Bolsón de Fiambalá, Fiambalá, Catamarca Province, Argentina Highest in the world[71]
Cerro Blanco ≈3,860/1,176 ≈6,791/2,080 Nazca Province, Ica Region, Peru 14°52′05″S 74°50′17″W / 14.868°S 74.838°W / -14.868; -74.838 (Cerro Blanco Dune) Highest in Peru, second highest in the world
Badain Jaran Dunes ≈1,640/500 ≈6,640/2,020 Badain Jaran Desert, Alashan Plain, Inner Mongolia, Gobi Desert, China World's tallest stationary dunes and highest in Asia[72]
Rig-e Yalan Dune ≈1,542/470 ≈3,117/950 Lut Desert, Kerman, Iran Hottest place on Earth (Gandom Beryan)
Average Highest Area Dunes 1,410/430? ≈6,500/1,980? Isaouane-n-Tifernine Sand Sea, Algerian Sahara Highest in Africa
Big Daddy/Dune 7
(Big Mama?)[73]
1,256/383 ≈1,870/570 Sossusvlei Dunes, Namib Desert, Namibia / Near Walvis Bay Namib Desert, Namibia according to the Namibian Ministry of Environment & Tourism the highest dune in the world
Mount Tempest ≈920/280 ≈920/280 Moreton Island, Brisbane, Australia Highest in Australia
Star Dune >750/230 ≈8,950/2,730 Great Sand Dunes National Park and Preserve, Colorado, USA Highest in North America
Dune of Pyla ≈345/105 ≈699/130 Bay of Arcachon, Aquitaine, France Highest in Europe
Ming-Sha Dunes ? 5,660/1,725 Dunhuang Oasis, Taklamakan Desert, Gansu, China
Medanoso Dune ≈1805/550 ≈5446/1,660 Atacama Desert, Chile Highest in Chile

Sand dune systems

(coastal dunes featuring succession)

Extraterrestrial dunes

 
Sand dune on Mars

Dunes can likely be found in any environment where there is a substantial atmosphere, winds, and dust to be blown. Dunes are common on Mars and in the equatorial regions of Titan.

Titan's dunes include large expanses with modal lengths of about 20–30 km. The regions are not topographically confined, resembling sand seas. These dunes are interpreted to be longitudinal dunes whose crests are oriented parallel to the dominant wind direction, which generally indicates west-to-east wind flow. The sand is likely composed of hydrocarbon particles, possibly with some water ice mixed in.[74]

Dunes are a popular theme in science fiction, featuring in depictions of dry Desert planets[75] appearing as early as the 1956 film Forbidden Planet and Frank Herbert's 1965 novel Dune.[76][77][78] The environment of the desert planet Arrakis (also known as Dune) in the Dune franchise[79] Dune in turn inspired the Star Wars franchise,[80] which includes prominent theme of dunes on fictional planets such as Tatooine, Geonosis, and Jakku.

See also

Notes

  1. ^ Jackson, Julia A., ed. (1997). "Dune [geomorph]". Glossary of geology (Fourth ed.). Alexandria, Virginia: American Geological Institute. ISBN 0922152349.
  2. ^ Pavlovic, Noel B. (2005). "Dune system". Encyclopedia of Chicago. Retrieved 15 January 2021.
  3. ^ "Sand dunes". Biology fieldwork. Field Studies Council. 2016. Retrieved 15 January 2021.
  4. ^ "Dune systems" (PDF). Michigan Department of Environmental Quality. (PDF) from the original on 20 September 2017. Retrieved 15 January 2021.
  5. ^ "The dune system". Restoconlife. Parco Nazionale Arcipelago Toscano. 2010. Retrieved 15 January 2021.
  6. ^ Jackson 1997, "Dune complex".
  7. ^ Jackson 1997, "Dune field".
  8. ^ "Erg Landforms". WorldLandForms. Retrieved 13 October 2019.
  9. ^ Jackson 1997, "Erg".
  10. ^ Jackson 1997, "Sand sea".
  11. ^ Jackson 1997, "Slip face".
  12. ^ Allaby, Michael, ed. (2008). "Dune slack". A dictionary of geology and earth sciences (Fourth ed.). Oxford: Oxford University Press. ISBN 9780199653065.
  13. ^ Thornbury, William D. (1969). Principles of geomorphology (2d ed.). New York: Wiley. pp. 288–302. ISBN 0471861979.
  14. ^ a b Fowler, H.W.; Fowler, F.G. (1984). Sykes, J.B. (ed.). The Concise Oxford Dictionary of Current English (7th ed.). Oxford: Clarendon Press. ISBN 978-0-19-861132-5.
  15. ^ Jackson 1997, "Dune [streams]".
  16. ^ McClelland, Mac (March 2015). "Slip Sliding Away". Audubon.
  17. ^ Rijckaert, Alix (20 November 2009). "Dutch construct dunes against rising seas". The Telegraph. Archived from the original on 11 January 2022. Retrieved 15 January 2021.
  18. ^ "Artificial Sand Dunes and Dunes Rehabilitation" (PDF). UNET DTU Partnership. 14 June 2018. (PDF) from the original on 17 November 2019. Retrieved 15 January 2021.
  19. ^ The intercolonial telegraph line at Eucla, accessed 1 April 2007.
  20. ^ "Dune—Define Dune". Dictionary.com. Dictionary.com, LLC. Retrieved 1 May 2018.
  21. ^ M.R. Leeder (6 December 2012). Sedimentology: Process and Product. Springer Science & Business Media. pp. 97–. ISBN 978-94-009-5986-6.
  22. ^ F. J. Pettijohn; P. E. Potter; R. Siever (6 December 2012). Sand and Sandstone. Springer Science & Business Media. pp. 346–. ISBN 978-1-4615-9974-6.
  23. ^ Jackson 1997, "Draa".
  24. ^ a b c d "Types of Dunes". U.S. Geological Survey. 29 October 1997. from the original on 14 March 2012. Retrieved 8 March 2012.
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References

Further reading

  • Ralph Lorenz; James Zimbelman (2014). Dune Worlds: How Wind-blown Sand Shapes Planetary Landscapes. Springer. ISBN 978-3-540-89724-8.
  • Anthony J. Parsons, A. D. Abrahams, ed. (2009). Geomorphology of Desert Environments. Springer. ISBN 978-1-4020-5718-2.
  • Pye, Kenneth; Tsoar, Haim (2009). Aeolian Sand and Sand Dunes. Springer. ISBN 978-3-540-85909-3.
  • . NASA Earth Observatory. Archived from the original on 30 September 2006. Retrieved 28 April 2006.
  • Badescu, V.; Cathcart, R. B.; Bolonkin, A. A. (2008). "Sand dune fixation: A solar-powered Sahara seawater pipeline macroproject". Land Degradation & Development. 19 (6): 676–691. doi:10.1002/ldr.864. S2CID 128961228.
  • . Desert Processes Working Group; Knowledge Sciences, Inc. Archived from the original on 21 October 2010. Retrieved 6 October 2010.
  • . Les dossiers thématiques du CSFD. Archived from the original on 25 July 2011. Retrieved 4 January 2011.

External links

  • Loibor Seder Kenya's Biggest Sand Dune
  • The Bibliography of Aeolian Research

dune, fiction, franchise, franchise, other, uses, disambiguation, dune, landform, composed, wind, water, driven, sand, typically, takes, form, mound, ridge, hill, area, with, dunes, called, dune, system, dune, complex, large, dune, complex, called, dune, field. For the fiction franchise see Dune franchise For other uses see Dune disambiguation A dune is a landform composed of wind or water driven sand It typically takes the form of a mound ridge or hill 1 An area with dunes is called a dune system 2 3 4 5 or a dune complex 6 A large dune complex is called a dune field 7 while broad flat regions covered with wind swept sand or dunes with little or no vegetation are called ergs or sand seas 8 9 10 Dunes occur in different shapes and sizes but most kinds of dunes are longer on the stoss upflow side where the sand is pushed up the dune and have a shorter slip face in the lee side 11 The valley or trough between dunes is called a dune slack 12 Coastal dunes in De Panne Belgium Coastal dunes at the Yyteri Beach in Pori Finland Cadiz Dunes Wilderness Sand dunes of the Empty Quarter to the east of Liwa Oasis United Arab Emirates Dunes are most common in desert environments where the lack of moisture hinders the growth of vegetation that would otherwise interfere with the development of dunes However sand deposits are not restricted to deserts and dunes are also found along sea shores along streams in semiarid climates in areas of glacial outwash and in other areas where poorly cemented sandstone bedrock disintegrates to produce an ample supply of loose sand 13 Subaqueous dunes can form from the action of water flow fluvial processes on sand or gravel beds of rivers estuaries and the sea bed 14 15 Some coastal areas have one or more sets of dunes running parallel to the shoreline directly inland from the beach In most cases the dunes are important in protecting the land against potential ravages by storm waves from the sea 16 Artificial dunes are sometimes constructed to protect coastal areas 17 18 The dynamic action of wind and water can sometimes cause dunes to drift which can have serious consequences For example the town of Eucla Western Australia had to be relocated in the 1890s because of dune drift 19 The modern word dune came into English from French around 1790 20 which in turn came from Middle Dutch dune 14 Contents 1 Formation 2 Aeolian dunes 2 1 Aeolian dune shapes 2 1 1 Barchan or crescentic 2 1 2 Transverse dunes 2 1 3 Seif or longitudinal dunes 2 1 4 Star 2 1 5 Dome 2 1 5 1 Lunettes 2 1 6 Parabolic 2 1 7 Reversing dunes 2 1 8 Draas 2 2 Dune complexity 2 3 Dune movement 2 4 Coastal dunes 2 4 1 Ecological succession on coastal dunes 2 4 2 Coastal dune floral adaptations 2 5 Gypsum dunes 2 6 Nabkha dunes 3 Sub aqueous dunes 4 Lithified dunes 5 Desertification 6 Conservation 7 Examples 7 1 Africa 7 2 Asia 7 3 Europe 7 4 North America 7 5 South America 7 6 Oceania 7 7 World s highest dunes 7 8 Sand dune systems 7 9 Extraterrestrial dunes 8 See also 9 Notes 10 References 11 Further reading 12 External linksFormation Edit Sand hitting sand is more likely to stick sand hitting a more coherent surface is more likely to bounce saltation This exacerbating feedback loop helps sand accumulate into dunes A universally precise distinction does not exist between ripples dunes and a draa 21 which are all deposits of the same type of materials Dunes are generally defined as greater than 7 cm tall and may have ripples while ripples are deposits that are less than 3 cm tall 22 A draa is a very large eolian landform with a length of several kilometers and a height of tens to hundreds of meters and which may have superimposed dunes 23 Dunes are made of sand sized particles and may consist of quartz calcium carbonate snow gypsum or other materials The upwind upstream upcurrent side of the dune is called the stoss side the downflow side is called the lee side Sand is pushed creep or bounces saltation up the stoss side and slides down the lee side A side of a dune that the sand has slid down is called a slip face or slipface The Bagnold formula gives the speed at which particles can be transported Aeolian dunes EditAeolian dune shapes Edit Five basic dune types are recognized crescentic linear star dome and parabolic Dune areas may occur in three forms simple isolated dunes of basic type compound larger dunes on which smaller dunes of same type form and complex combinations of different types 24 Barchan or crescentic Edit Main article barchan Isolated barchan dunes on the surface of Mars Dominant wind direction would be from left to right Barchan dunes are crescent shaped mounds which are generally wider than they are long The lee side slipfaces are on the concave sides of the dunes These dunes form under winds that blow consistently from one direction unimodal winds They form separate crescents when the sand supply is comparatively small When the sand supply is greater they may merge into barchanoid ridges and then transverse dunes see below Some types of crescentic dunes move more quickly over desert surfaces than any other type of dune A group of dunes moved more than 100 metres per year between 1954 and 1959 in China s Ningxia Province and similar speeds have been recorded in the Western Desert of Egypt The largest crescentic dunes on Earth with mean crest to crest widths of more than three kilometres are in China s Taklamakan Desert 24 See lunettes and parabolic dunes below for dunes similar to crescent shaped ones Transverse dunes Edit Abundant barchan dunes may merge into barchanoid ridges which then grade into linear or slightly sinuous transverse dunes so called because they lie transverse or across the wind direction with the wind blowing perpendicular to the ridge crest 25 Seif or longitudinal dunes Edit Seif dunes are linear or slightly sinuous dunes with two slip faces 25 The two slip faces make them sharp crested They are called seif dunes after the Arabic word for sword They may be more than 160 kilometres 100 miles long and thus easily visible in satellite images see illustrations Seif dunes are associated with bidirectional winds The long axes and ridges of these dunes extend along the resultant direction of sand movement hence the name longitudinal 26 Some linear dunes merge to form Y shaped compound dunes 24 Formation is debated Ralph Bagnold in The Physics of Blown Sand and Desert Dunes suggested that some seif dunes form when a barchan dune moves into a bidirectional wind regime and one arm or wing of the crescent elongates Others suggest that seif dunes are formed by vortices in a unidirectional wind 25 In the sheltered troughs between highly developed seif dunes barchans may be formed because the wind is constrained to be unidirectional by the dunes Rub al Khali Arabian Empty Quarter sand dunes imaged by Terra EOS AM 1 Most of these dunes are seif dunes Their origin from barchans is suggested by the stubby remnant hooks seen on many of the dunes Wind would be from left to right Large linear seif dunes in the Great Sand Sea in southwest Egypt seen from the International Space Station The distance between each dune is 1 5 2 5 km The average direction longitudinal model of seif dune formation By contrast transverse dunes form with the wind blowing perpendicular to the ridges and have only one slipface on the lee side The stoss side is less steep Transverse dunes lie perpendicular to the wind which moves them forwards producing the cross bedding shown here Seif dunes are common in the Sahara They range up to 300 m 980 ft in height and 300 km 190 mi in length In the southern third of the Arabian Peninsula a vast erg called the Rub al Khali or Empty Quarter contains seif dunes that stretch for almost 200 km 120 mi and reach heights of over 300 m 980 ft Linear loess hills known as pahas are superficially similar These hills appear to have been formed during the last ice age under permafrost conditions dominated by sparse tundra vegetation Star Edit Radially symmetrical star dunes are pyramidal sand mounds with slipfaces on three or more arms that radiate from the high center of the mound They tend to accumulate in areas with multidirectional wind regimes Star dunes grow upward rather than laterally They dominate the Grand Erg Oriental of the Sahara In other deserts they occur around the margins of the sand seas particularly near topographic barriers In the southeast Badain Jaran Desert of China the star dunes are up to 500 metres tall and may be the tallest dunes on Earth Dome Edit Oval or circular mounds that generally lack a slipface Dome dunes are rare and occur at the far upwind margins of sand seas Lunettes Edit Fixed crescentic dunes that form on the leeward margins of playas and river valleys in arid and semiarid regions in response to the direction s of prevailing winds are known as lunettes source bordering dunes bourrelets and clay dunes They may be composed of clay silt sand or gypsum eroded from the basin floor or shore transported up the concave side of the dune and deposited on the convex side Examples in Australia are up to 6 5 km long 1 km wide and up to 50 metres high They also occur in southern and West Africa and in parts of the western United States especially Texas 27 Parabolic Edit Schematic of coastal parabolic dunes U shaped mounds of sand with convex noses trailed by elongated arms are parabolic dunes These dunes are formed from blowout dunes where the erosion of vegetated sand leads to a U shaped depression The elongated arms are held in place by vegetation the largest arm known on Earth reaches 12 km Sometimes these dunes are called U shaped blowout or hairpin dunes and they are well known in coastal deserts Unlike crescent shaped dunes their crests point upwind The bulk of the sand in the dune migrates forward In plan view these are U shaped or V shaped mounds of well sorted very fine to medium sand with elongated arms that extend upwind behind the central part of the dune There are slipfaces that often occur on the outer side of the nose and on the outer slopes of the arms These dunes often occur in semiarid areas where the precipitation is retained in the lower parts of the dune and underlying soils The stability of the dunes was once attributed to the vegetative cover but recent research has pointed to water as the main source of parabolic dune stability The vegetation that covers them grasses shrubs and trees help anchor the trailing arms In inland deserts parabolic dunes commonly originate and extend downwind from blowouts in sand sheets only partly anchored by vegetation They can also originate from beach sands and extend inland into vegetated areas in coastal zones and on shores of large lakes Most parabolic dunes do not reach heights higher than a few tens of metres except at their nose where vegetation stops or slows the advance of accumulating sand Simple parabolic dunes have only one set of arms that trail upwind behind the leading nose Compound parabolic dunes are coalesced features with several sets of trailing arms Complex parabolic dunes include subsidiary superposed or coalesced forms usually of barchanoid or linear shapes Parabolic dunes like crescent dunes occur in areas where very strong winds are mostly unidirectional Although these dunes are found in areas now characterized by variable wind speeds the effective winds associated with the growth and migration of both the parabolic and crescent dunes probably are the most consistent in wind direction The grain size for these well sorted very fine to medium sands is about 0 06 to 0 5 mm Parabolic dunes have loose sand and steep slopes only on their outer flanks The inner slopes are mostly well packed and anchored by vegetation as are the corridors between individual dunes Because all dune arms are oriented in the same direction and the inter dune corridors are generally swept clear of loose sand the corridors can usually be traversed in between the trailing arms of the dune However to cross straight over the dune by going over the trailing arms can be very difficult Also traversing the nose is very difficult as well because the nose is usually made up of loose sand without much if any vegetation A type of extensive parabolic dune that lacks discernible slipfaces and has mostly coarse grained sand is known as a zibar 28 The term zibar comes from the Arabic word to describe rolling transverse ridges with a hard surface 29 The dunes are small have low relief and can be found in many places across the planet from Wyoming United States to Saudi Arabia to Australia 30 Spacing between zibars ranges from 50 to 400 metres and they don t become more than 10 metres high 31 The dunes form at about ninety degrees to the prevailing wind which blows away the small fine grained sand leaving behind the coarser grained sand to form the crest 32 Reversing dunes Edit Reversing dune showing short minor slipface atop the major stoss upwind face Occurring wherever winds periodically reverse direction reversing dunes are varieties of any of the above shapes These dunes typically have major and minor slipfaces oriented in opposite directions The minor slipfaces are usually temporary as they appear after a reverse wind and are generally destroyed when the wind next blows in the dominant direction 25 Draas Edit Dune Nine in Sossusvlei Namibia is over 300m high Draas are very large scale dune bedforms they may be tens or a few hundreds of metres in height kilometres wide and hundreds of kilometres in length 25 After a draa has reached a certain size it generally develops superimposed dune forms 33 They are thought to be more ancient and slower moving than smaller dunes 25 and to form by vertical growth of existing dunes Draas are widespread in sand seas and are well represented in the geological record 33 Dune complexity Edit All these dune shapes may occur in three forms simple isolated dunes of basic type compound larger dunes on which smaller dunes of same type form and complex combinations of different types 24 Simple dunes are basic forms with the minimum number of slipfaces that define the geometric type Compound dunes are large dunes on which smaller dunes of similar type and slipface orientation are superimposed Complex dunes are combinations of two or more dune types A crescentic dune with a star dune superimposed on its crest is the most common complex dune Simple dunes represent a wind regime that has not changed in intensity or direction since the formation of the dune while compound and complex dunes suggest that the intensity and direction of the wind has changed Dune movement Edit The sand mass of dunes can move either windward or leeward depending on if the wind is making contact with the dune from below or above its apogee If wind hits from above the sand particles move leeward the leeward flux of sand is greater than the windward flux Conversely if sand hits from below sand particles move windward Further if the wind is carrying sand particles when it hits the dune the dune s sand particles will saltate more than if the wind had hit the dune without carrying sand particles 34 Coastal dunes Edit Coastal dunes covered in grasses around the mouth of the Liver A river in Denmark source source source source source source source source Newborough Dune Rejuvenation Wales video of work done by Natural Resources Wales 2015 Coastal dunes 35 form when wet sand is deposited along the coast and dries out and is blown along the beach 36 Dunes form where the beach is wide enough to allow for the accumulation of wind blown sand and where prevailing onshore winds tend to blow sand inland The three key ingredients for coastal dune formation are a large sand supply winds to move said sand supply and a place for the sand supply to accumulate 37 Obstacles for example vegetation pebbles and so on tend to slow down the wind and lead to the deposition of sand grains 38 These small incipient dunes or shadow dunes tend to grow in the vertical direction if the obstacle slowing the wind can also grow vertically i e vegetation Coastal dunes expand laterally as a result of lateral growth of coastal plants via seed or rhizome 39 40 Models of coastal dunes suggest that their final equilibrium height is related to the distance between the water line and where vegetation can grow 41 Coastal dunes can be classified by where they develop or begin to take shape Dunes are commonly grouped into either the Primary Dune Group or the Secondary Dune Group 35 Primary dunes gain most of their sand from the beach itself while secondary dunes gain their sand from the primary dune Along the Florida Panhandle most dunes are considered to be foredunes or hummocks 42 43 Different locations around the globe have dune formations unique to their given coastal profile Coastal sand dunes can provide privacy and or habitats to support local flora and fauna Animals such as sand snakes lizards and rodents can live in coastal sand dunes along with insects of all types 44 Often the vegetation of sand dunes is discussed without acknowledging the importance that coastal dunes have for animals Further some animals such as foxes and feral pigs can use coastal dunes as hunting grounds to find food 45 Birds are also known to utilize coastal dunes as nesting grounds All these species find the coastal environment of the sand dune vital to their species survival Over the course of time coastal dunes may be impacted by tropical cyclones or other intense storm activity dependent on their location Recent work has suggested that coastal dunes tend to evolve toward a high or low morphology depending on the growth rate of dunes relative to storm frequency 46 47 During a storm event dunes play a significant role in minimizing wave energy as it moves onshore As a result coastal dunes especially those in the foredune area affected by a storm surge will retreat or erode 48 To counteract the damage from tropical activity on coastal dunes short term post storm efforts can be made by individual agencies through fencing to help with sand accumulation 49 How much a dune erodes during any storm surge is related to its location on the coastal shoreline and the profile of the beach during a particular season In those areas with harsher winter weather during the summer a beach tends to take on more of a convex appearance due to gentler waves while the same beach in the winter may take on more of a concave appearance As a result coastal dunes can get eroded much more quickly in the winter than in the summer The converse is true in areas with harsher summer weather 50 There are many threats to these coastal communities Some coastal dunes for example ones in San Francisco have been completely altered by urbanization reshaping the dune for human use This puts native species at risk Another danger in California and places in the UK specifically is the introduction of invasive species Plant species such as Carpobrotus edulis were introduced from South Africa in an attempt to stabilize the dunes and provide horticultural benefits but instead spread taking land away from native species Ammophila arenaria known as European beachgrass has a similar story though it has no horticulture benefits It has great ground coverage and as intended stabilized the dunes but as an unintended side effect prevented native species from thriving in those dunes One such example is the dune field at Point Reyes California There are now efforts to get rid of both of these invasive species 51 52 Ecological succession on coastal dunes Edit As a dune forms plant succession occurs The conditions on an embryo dune are harsh with salt spray from the sea carried on strong winds The dune is well drained and often dry and composed of calcium carbonate from seashells Rotting seaweed brought in by storm waves adds nutrients to allow pioneer species to colonize the dune For example in the United Kingdom these pioneer species are often marram grass sea wort grass and other sea grasses These plants are well adapted to the harsh conditions of the foredune typically having deep roots which reach the water table root nodules that produce nitrogen compounds and protected stoma reducing transpiration Also the deep roots bind the sand together and the dune grows into a foredune as more sand is blown over the grasses The grasses add nitrogen to the soil meaning other less hardy plants can then colonize the dunes Typically these are heather heaths and gorses These too are adapted to the low soil water content and have small prickly leaves which reduce transpiration Heather adds humus to the soil and is usually replaced by coniferous trees which can tolerate low soil pH caused by the accumulation and decomposition of organic matter with nitrate leaching 53 Coniferous forests and heathland are common climax communities for sand dune systems Young dunes are called yellow dunes and dunes which have high humus content are called grey dunes Leaching occurs on the dunes washing humus into the slacks and the slacks may be much more developed than the exposed tops of the dunes It is usually in the slacks that more rare species are developed and there is a tendency for the dune slacks soil to be waterlogged where only marsh plants can survive In Europe these plants include creeping willow cotton grass yellow iris reeds and rushes As for vertebrates in European dunes natterjack toads sometimes breed here Coastal dune floral adaptations Edit Sand dunes of Hyypanmaki in Hailuoto Finland source source source source source source source source Sea dune erosion at Talacre Wales Dune ecosystems are extremely difficult places for plants to survive This is due to a number of pressures related to their proximity to the ocean and confinement to growth on sandy substrates These include Little available soil moisture Little available soil organic matter nutrients water Harsh winds Salt spray Erosion shifting and sometimes burial or exposure from shifting Tidal influencesPlants have evolved many adaptations to cope with these pressures Deep taproot to reach water table Pink Sand Verbena Shallow but extensive root systems Rhizomes Prostrate growth form to avoid wind salt spray Abronia spp Beach Primrose Krummholz growth form Monterrey Cypress not a dune plant but deals with similar pressures Thickened cuticle Succulence to reduce moisture loss and reduce salt uptake Ambrosia Abronia spp Calystegia soldanella Pale leaves to reduce insolation Artemisia Ambrosia spp Thorny Spiky seeds to ensure establishment in vicinity of parent reduces chances of being blown away or swept out to sea Ambrosia chamissonis Gypsum dunes Edit Gypsum dune fields White Sands National Park New Mexico United States In deserts where large amounts of limestone mountains surround a closed basin such as at White Sands National Park in south central New Mexico occasional storm runoff transports dissolved limestone and gypsum into a low lying pan within the basin where the water evaporates depositing the gypsum and forming crystals known as selenite The crystals left behind by this process are eroded by the wind and deposited as vast white dune fields that resemble snow covered landscapes These types of dune are rare and only form in closed arid basins that retain the highly soluble gypsum that would otherwise be washed into the sea 54 Nabkha dunes Edit A nabkha or coppice dune is a small dune anchored by vegetation They usually indicate desertification or soil erosion and serve as nesting and burrow sites for animals Sub aqueous dunes EditMain article Ripple marks Sub aqueous underwater dunes form on a bed of sand or gravel under the actions of water flow They are ubiquitous in natural channels such as rivers and estuaries and also form in engineered canals and pipelines 55 56 57 Dunes move downstream as the upstream slope is eroded and the sediment deposited on the downstream or lee slope in typical bedform construction 58 In the case of sub aqueous barchan dunes sediment is lost by their extremities known as horns 59 60 These dunes most often form as a continuous train of dunes showing remarkable similarity in wavelength and height The shape of a dune gives information about its formation environment 61 For instance rivers produce asymmetrical ripples with the steeper slip face facing downstream Ripple marks preserved in sedimentary strata in the geological record can be used to determine the direction of current flow and thus an indication of the source of the sediments Dunes on the bed of a channel significantly increase flow resistance their presence and growth playing a major part in river flooding Lithified dunes Edit Cross bedding in lithified aeolian sand dunes preserved as sandstone in Zion National Park Utah A lithified consolidated sand dune is a type of sandstone that is formed when a marine or aeolian sand dune becomes compacted and hardened Once in this form water passing through the rock can carry and deposit minerals which can alter the color of the rock Cross bedded layers of stacks of lithified dunes can produce the cross hatching patterns such as those seen in Zion National Park in the western United States A slang term used in the southwest US for consolidated and hardened sand dunes is slickrock a name that was introduced by pioneers of the Old West because their steel rimmed wagon wheels could not gain traction on the rock citation needed Desertification EditMain article Desertification Sand dunes can have a negative impact on humans when they encroach on human habitats Sand dunes move via a few different means all of them helped along by wind One way that dunes can move is by saltation where sand particles skip along the ground like a bouncing ball When these skipping particles land they may knock into other particles and cause them to move as well in a process known as creep With slightly stronger winds particles collide in mid air causing sheet flows In a major dust storm dunes may move tens of metres through such sheet flows Also as in the case of snow sand avalanches falling down the slipface of the dunes that face away from the winds also move the dunes forward Sand threatens buildings and crops in Africa the Middle East and China Drenching sand dunes with oil stops their migration but this approach uses a valuable resource and is quite destructive to the dunes animal habitats Sand fences might also slow their movement to a crawl but geologists are still analyzing results for the optimum fence designs 62 Preventing sand dunes from overwhelming towns villages and agricultural areas has become a priority for the United Nations Environment Programme Planting dunes with vegetation also helps to stabilise them Conservation Edit Sand blowing off a crest in the Kelso Dunes of the Mojave Desert California USA Dune habitats provide niches for highly specialized plants and animals including numerous rare species and some endangered species Due to widespread human population expansion dunes face destruction through land development and recreational usages as well as alteration to prevent the encroachment of sand onto inhabited areas Some countries notably the United States Australia Canada New Zealand the United Kingdom Netherlands and Sri Lanka have developed significant programs of dune protection through the use of sand dune stabilization In the U K a Biodiversity Action Plan has been developed to assess dunes loss and to prevent future dunes destruction Examples EditAfrica Edit A dune in Sossusvlei in the greater Namib Naukluft National Park Namibia Note the trees being engulfed for scale Camelthorn trees and bushes scattered on dunes in the Kalahari Desert in Namibia 2017 Sand dune in the Libyan Desert near Dakhla Oasis at sunset Alexandria Coastal Dunefields in the Eastern Cape South Africa 63 Witsand Nature Reserve in the Kalahari Desert South Africa The white dunes of De Hoop Nature Reserve South Africa The dunes of the Suguta Valley a desert part of the Great Rift Valley in northwestern Kenya The dunes of the Danakil Depression northeastern Ethiopia toward the border with Eritrea The dunes of Sossusvlei in the greater Namib Naukluft National Park Namibia The coastal dunes of Iona National Park in the southwesternmost part of Angola Khawa dunes in the Kgalagadi Transfrontier Park the southwesternmost part of Botswana La Dune Rose in the city of Gao in northern Mali near the Niger River Erg Aoukar in southeastern Mauritania extending into Mali Erg Chech in southwestern Algeria and northern Mali Erg Chebbi and Erg Chigaga in southern Morocco Grand Erg Oriental in northeastern Algeria and southern Tunisia Grand Erg Occidental in western Algeria The Idehan Ubari and the Idehan Murzuq in southwestern Libya The Corralejo dunes in the Canary Islands Spain The Rebiana Sand Sea in southeastern Libya The Great Sand Sea in southeastern Libya and southwestern Egypt The Selima Sand Sheet in northwestern Sudan The dunes of the Bayuda Desert in northern Sudan The dunes of the Lompoul Desert in northwestern Senegal The coastal dunes of Bazaruto Island Mozambique Erg du Djourab in northern Chad The dunes of the Mourdi Depression in northeastern Chad The dunes of Tin Toumma Desert in southeastern Niger Grand Erg de Bilma in the Tenere in northern Niger The dunes of Oursi in the Sahel Region northern Burkina Faso Tanzania s Shifting Sands near Olduvai Gorge Wind ripples on crescent shaped sand dunes barchans in southwest Afghanistan Sistan Asia Edit Sunset view dunes in the Alankuda village on Kalpitiya peninsula in Sri Lanka https goo gl maps Hy96XnvbkQBAB53F8 The dunes in the Thar Desert in India and Pakistan Tottori Sand Dunes Tottori Prefecture Japan Rig e Jenn in the Central Desert of Iran Rig e Lut in the Southeast of Iran The Ilocos Norte Sand Dunes in the Philippines particularly Paoay Sand Dunes Moreeb Dune in Liwa Oasis United Arab Emirates used as an arena for drag motor sports and Sandboarding Gumuk Pasir Parangkusumo near Parangtritis beach in Yogyakarta Indonesia Mui Ne Vietnam Wahiba Sands Oman Teri red dune complex in southern India The dunes of the Taklamakan Desert in southwest Xinjiang in Northwest China Tukulans of the Central Yakutian Lowland Russia Fronting the Mediterranean Sea in Oliva Valencian Community Spain Europe Edit 50 m 160 ft tall dune in Salir do Porto Portugal Sand dunes of Lemnos Greece The Dunes of Dyuni near Pomorie Bulgaria vast area of sand dunes in the Burgas Province The Dune of Pilat not far from Bordeaux France is the largest known sand dune in Europe The Dunes of Piscinas in the south west of Sardinia island Sands of Forvie within the Ythan Estuary complex Aberdeenshire Scotland Oxwich Dunes near Swansea is on the Gower Peninsula in Wales Winterton Dunes Norfolk England Slowinski National Park Poland Siedlec Desert Poland Starczynow Desert now mostly forested dunes Poland Sand dunes of Lemnos Lesbos Prefecture Greece Akrotiri Sand Dune Lemesos Cyprus Rabjerg mile Northern Jutland Denmark Thy National Park North Denmark Region Denmark Dunes of Corrubedo Spain Cresmina Dune Portugal Northern Littoral Natural Park Portugal Dune of Salir Portugal Sao Jacinto Dunes Natural Reserve Portugal Rera e Hedhur in Shengjin Albania De Hoge Veluwe National Park Veluwe Netherlands Kootwijkerzand Veluwe Netherlands 7 km2 Dunes of Texel National Park Texel Netherlands Zuid Kennemerland National Park North Holland Netherlands Ammothines Lemnou Lemnos Greece Dunes of the Curonian Spit Lithuania and Russia Parnidis Dune Vecekrugas Dune Curonian Spit Lithuania Oleshky Sands Ukraine Ullahau Sweden Big Parabel Dune and dune systemNorth America Edit Guadalupe Nipomo Dunes Cadiz Dunes Wilderness California Victoria Island Sand Dunes 160 km North West of Cambridge Bay Nunavut Canada Approximately 600 square kilometers the largest in Canada third largest in North America and the largest in the Arctic There are two lakes with direct access to the Dunes from float planes Herring Cove 64 Race Point 65 and The Province Lands bicycle path 66 in Provincetown Massachusetts as part of the US National Park Service of the Cape Cod National Seashore Great Kobuk Sand Dunes Kobuk Valley National Park Alaska 67 The Athabasca Sand Dunes located in the Athabasca Sand Dunes Provincial Park Saskatchewan The Cadiz Dunes in the Mojave Trails National Monument in California The Kelso Dunes in the Mojave Desert of California Eureka Valley Sand Dunes and Mesquite Flat Sand Dunes in Death Valley National Park California Great Sand Dunes National Park Colorado White Sands National Park New Mexico Little Sahara Recreation Area Utah Sleeping Bear Dunes National Lakeshore Michigan on the east shore of Lake Michigan Indiana Dunes National Park Indiana on the south shore of Lake Michigan 68 69 Warren Dunes State Park Michigan on the east shore of Lake Michigan Grand Sable Dunes in the Pictured Rocks National Lakeshore Michigan Samalayuca Dunes in the state of Chihuahua Mexico Algodones Dunes near Brawley California Guadalupe Nipomo Dunes on the central coast of California Monahans Sandhills State Park near Odessa Texas Beaver Dunes State Park near Beaver Oklahoma The Killpecker sand dunes of the Red Desert in southwestern Wyoming Jockey s Ridge State Park on the Outer Banks North Carolina The Great Dune found in Cape Henlopen State Park in Lewes Delaware Oregon Dunes National Recreation Area near Florence Oregon on the Pacific Coast Bruneau Dunes State Park Owyhee Desert Idaho Hoffmaster State Park Muskegon Michigan Silver Lake State Park a sand dunes that allows off road vehicle use located near Mears Michigan Carcross Desert near Carcross Yukon Grey Cloud Dunes Minnesota 70 South America Edit White sand dunes in the Lencois Maranhenses National Park Maranhao Brazil Lencois Maranhenses National Park in the state of Maranhao Brazil Jericoacoara National Park in the state of Ceara Brazil Genipabu in Natal Brazil Medanos de Coro National Park near the town of Coro in Falcon State Venezuela Duna Federico Kirbus in Catamarca Province Argentina Villa Gesell in Buenos Aires Province Argentina Cerro Blanco in Nazca Province Peru Huacachina in Ica Region Peru Cerro Medanoso in Atacama Region Chile Colun Beach Valdivian Coastal Reserve in Chile es Dunas de Concon Chile es Cerro Dragon Chile urban dune in Iquique Chile Coastal dunes at Stockton Beach in the City of Newcastle Oceania Edit Simpson Desert sand dunes in the Northern Territory Queensland and South Australia Australia Fraser Island in Queensland Australia Cronulla sand dunes in New South Wales Australia Stockton Beach in New South Wales Australia Lancelin sand dunes in Western Australia Australia Te Paki sand dunes near Cape Reinga New Zealand World s highest dunes Edit Note This table is partially based on estimates and incomplete information Dune Height from Base feet metres Height from Sea Level feet metres Location NotesDuna Federico Kirbus 4 035 1 230 9 334 2 845 Bolson de Fiambala Fiambala Catamarca Province Argentina Highest in the world 71 Cerro Blanco 3 860 1 176 6 791 2 080 Nazca Province Ica Region Peru 14 52 05 S 74 50 17 W 14 868 S 74 838 W 14 868 74 838 Cerro Blanco Dune Highest in Peru second highest in the worldBadain Jaran Dunes 1 640 500 6 640 2 020 Badain Jaran Desert Alashan Plain Inner Mongolia Gobi Desert China World s tallest stationary dunes and highest in Asia 72 Rig e Yalan Dune 1 542 470 3 117 950 Lut Desert Kerman Iran Hottest place on Earth Gandom Beryan Average Highest Area Dunes 1 410 430 6 500 1 980 Isaouane n Tifernine Sand Sea Algerian Sahara Highest in AfricaBig Daddy Dune 7 Big Mama 73 1 256 383 1 870 570 Sossusvlei Dunes Namib Desert Namibia Near Walvis Bay Namib Desert Namibia according to the Namibian Ministry of Environment amp Tourism the highest dune in the worldMount Tempest 920 280 920 280 Moreton Island Brisbane Australia Highest in AustraliaStar Dune gt 750 230 8 950 2 730 Great Sand Dunes National Park and Preserve Colorado USA Highest in North AmericaDune of Pyla 345 105 699 130 Bay of Arcachon Aquitaine France Highest in EuropeMing Sha Dunes 5 660 1 725 Dunhuang Oasis Taklamakan Desert Gansu ChinaMedanoso Dune 1805 550 5446 1 660 Atacama Desert Chile Highest in ChileSand dune systems Edit coastal dunes featuring succession Athabasca Sand Dunes Provincial Park Alberta and Saskatchewan Ashdod Sand Dune Israel Bamburgh Dunes Northumberland England Bradley Beach New Jersey Circeo National Park a Mediterranean dune area on the southwest coast of the Lazio region of Italy Cronulla sand dunes NSW Australia Crymlyn Burrows Wales Dawlish Warren Devon England Fraser Island Queensland Australia largest sand island in the world Indiana Dunes National Park Indiana Kenfig Burrows Wales Margam burrows Wales Murlough Sand Dunes Newcastle Co Down Northern Ireland Morfa Harlech sand dunes Gwynedd Wales Newborough Warren North Wales Oregon Dunes National Recreation Area near North Bend Oregon Penhale Sands Cornwall England Sleeping Bear Dunes National Lakeshore Michigan Sandy Island Beach State Park Richland New York Studland Dorset England Thy National Park North Denmark Region Denmark Winterton Norfolk England Woolacombe Devon England Ynyslas Sand Dunes WalesExtraterrestrial dunes Edit Sand dune on Mars See also List of extraterrestrial dune fields Dunes can likely be found in any environment where there is a substantial atmosphere winds and dust to be blown Dunes are common on Mars and in the equatorial regions of Titan Titan s dunes include large expanses with modal lengths of about 20 30 km The regions are not topographically confined resembling sand seas These dunes are interpreted to be longitudinal dunes whose crests are oriented parallel to the dominant wind direction which generally indicates west to east wind flow The sand is likely composed of hydrocarbon particles possibly with some water ice mixed in 74 Dunes are a popular theme in science fiction featuring in depictions of dry Desert planets 75 appearing as early as the 1956 film Forbidden Planet and Frank Herbert s 1965 novel Dune 76 77 78 The environment of the desert planet Arrakis also known as Dune in the Dune franchise 79 Dune in turn inspired the Star Wars franchise 80 which includes prominent theme of dunes on fictional planets such as Tatooine Geonosis and Jakku See also EditAntidune Devil s stovepipe Ice dune List of landforms Masseira Medanos Sandhill Sand wave Singing sand Strand plainNotes Edit Jackson Julia A ed 1997 Dune geomorph Glossary of geology Fourth ed Alexandria Virginia American Geological Institute ISBN 0922152349 Pavlovic Noel B 2005 Dune system Encyclopedia of Chicago Retrieved 15 January 2021 Sand dunes Biology fieldwork Field Studies Council 2016 Retrieved 15 January 2021 Dune systems PDF Michigan Department of Environmental Quality Archived PDF from the original on 20 September 2017 Retrieved 15 January 2021 The dune system Restoconlife Parco Nazionale Arcipelago Toscano 2010 Retrieved 15 January 2021 Jackson 1997 Dune complex Jackson 1997 Dune field Erg Landforms WorldLandForms Retrieved 13 October 2019 Jackson 1997 Erg Jackson 1997 Sand sea Jackson 1997 Slip face Allaby Michael ed 2008 Dune slack A dictionary of geology and earth sciences Fourth ed Oxford Oxford University Press ISBN 9780199653065 Thornbury William D 1969 Principles of geomorphology 2d ed New York Wiley pp 288 302 ISBN 0471861979 a b Fowler H W Fowler F G 1984 Sykes J B ed The Concise Oxford Dictionary of Current English 7th ed Oxford Clarendon Press ISBN 978 0 19 861132 5 Jackson 1997 Dune streams McClelland Mac March 2015 Slip Sliding Away Audubon Rijckaert Alix 20 November 2009 Dutch construct dunes against rising seas The Telegraph Archived from the original on 11 January 2022 Retrieved 15 January 2021 Artificial Sand Dunes and Dunes Rehabilitation PDF UNET DTU Partnership 14 June 2018 Archived PDF from the original on 17 November 2019 Retrieved 15 January 2021 The intercolonial telegraph line at Eucla accessed 1 April 2007 Dune Define Dune Dictionary com Dictionary com LLC Retrieved 1 May 2018 M R Leeder 6 December 2012 Sedimentology Process and Product Springer Science amp Business Media pp 97 ISBN 978 94 009 5986 6 F J Pettijohn P E Potter R Siever 6 December 2012 Sand and Sandstone Springer Science amp Business Media pp 346 ISBN 978 1 4615 9974 6 Jackson 1997 Draa a b c d Types of Dunes U S Geological Survey 29 October 1997 Archived from the original on 14 March 2012 Retrieved 8 March 2012 a b c d e f Mangimeli John 10 September 2007 Geology of Sand Dunes U S A National Park Service Retrieved 15 January 2021 Radebaugh Jani Sharma Priyanka Korteniemi Jarmo Fitzsimmons Kathryn E 2014 Longitudinal Dunes or Linear Dunes Encyclopedia of Planetary Landforms pp 1 11 doi 10 1007 978 1 4614 9213 9 460 2 ISBN 978 1 4614 9213 9 Twidale C R amp Campbell E M 2005 revised edition Australian landforms understanding a low flat arid and old landscape Rosenberg Publishing pp 241 3 ISBN 1 877058 32 7 Goudie Ron Cooke Andrew Warren Andrew 1996 Desert geomorphology 2 impr ed London UCL Press pp 395 396 ISBN 978 1 85728 017 3 Goudie Ron Cooke Andrew Warren Andrew 1996 Desert geomorphology 2 impr ed London UCL Press p 395 ISBN 978 1 85728 017 3 USGS Landform Glossary PDF United States Geological Survey Retrieved 3 October 2013 permanent dead link Warren A December 1971 Dunes in the Tenere Desert The Geographical Journal 137 4 458 461 doi 10 2307 1797141 JSTOR 1797141 Nielson Jamie Kocurek Gary June 1986 Climbing Zibars of the Algodones Sedimentary Geology 48 1 2 1 15 Bibcode 1986SedG 48 1N doi 10 1016 0037 0738 86 90078 3 a b Lancaster N 1 March 1988 The development of large aeolian bedforms Sedimentary Geology 55 1 2 69 89 Bibcode 1988SedG 55 69L doi 10 1016 0037 0738 88 90090 5 Jiang Hong Dun Hongchao Tong Ding Huang Ning 15 April 2017 Sand transportation and reverse patterns over leeward face of sand dune Geomorphology 283 41 47 Bibcode 2017Geomo 283 41J doi 10 1016 j geomorph 2016 12 030 a b Sloss C R Shepherd M Hesp P 2012 Coastal Dunes Geomorphology Nature Education Knowledge 3 10 2 Retrieved 15 January 2021 Bird ECF 1976 Coasts an introduction to systematic geomorphology Canberra Australia Australian National University Press ASIN B004750SVK Goldsmith Victor 1978 Coastal Dunes Coastal Sedimentary Environments 171 235 doi 10 1007 978 1 4684 0056 4 5 ISBN 978 1 4684 0058 8 Hesp P 1989 A review of biological and geomorphological processes involved in the initiation and development of incipient foredunes Proceedings of the Royal Society of Edinburgh Section B Biological Sciences 96 181 201 doi 10 1017 S0269727000010927 Godfrey P J 1 September 1977 Climate plant response and development of dunes on barrier beaches along the U S east coast International Journal of Biometeorology 21 3 203 216 Bibcode 1977IJBm 21 203G doi 10 1007 BF01552874 ISSN 0020 7128 S2CID 85391018 Goldstein Evan B Moore Laura J Vinent Orencio Duran 8 August 2017 Lateral vegetation growth rates exert control on coastal foredune hummockiness and coalescing time Earth Surface Dynamics 5 3 417 427 doi 10 5194 esurf 5 417 2017 ISSN 2196 6311 Duran O Moore L J 2013 Vegetation controls on the maximum size of coastal dunes Proceedings of the National Academy of Sciences 110 43 17217 17222 Bibcode 2013PNAS 11017217D doi 10 1073 pnas 1307580110 PMC 3808624 PMID 24101481 Houser C Hapke C Hamilton S 15 August 2008 Controls on coastal dune morphology shoreline erosion and barrier island response to extreme storms Geomorphology 100 3 4 223 40 Bibcode 2008Geomo 100 223H doi 10 1016 j geomorph 2007 12 007 Claudino Sales V Wang P Horwitz MH 15 March 2008 Factors controlling the survival of coastal dunes during multiple hurricane impacts in 2004 and 2005 Santa Rosa Barrier Island Florida Geomorphology 95 3 4 295 315 Bibcode 2008Geomo 95 295C doi 10 1016 j geomorph 2007 06 004 Ronica D 27 October 2008 How sand dunes work HowStuffWorks Retrieved 4 December 2018 Hill K Dune Habitats Smithsonian Marine Station Retrieved 4 December 2018 Duran Vinent Orencio Moore Laura February 2015 Barrier island bistability induced by biophysical interactions Nature Climate Change 5 2 158 162 Bibcode 2015NatCC 5 158D doi 10 1038 nclimate2474 ISSN 1758 6798 Goldstein Evan B Moore Laura J 2016 Stability and bistability in a one dimensional model of coastal foredune height Journal of Geophysical Research Earth Surface 121 5 964 977 Bibcode 2016JGRF 121 964G doi 10 1002 2015JF003783 ISSN 2169 9011 Morton RA 1 May 1976 Effects of Hurricane Eloise on beach and coastal structures Florida Panhandle Geology 4 5 277 80 Bibcode 1976Geo 4 277M doi 10 1130 0091 7613 1976 4 lt 277 EOHEOB gt 2 0 CO 2 Charbonneau B Wnek JP 24 September 2018 Reactionary fence installation for post Superstorm Sandy dune recovery EarthArXiv Retrieved 4 December 2018 Maine Sea Grant Seasonal changes Maine Sea Grant College Program Archived from the original on 5 December 2018 Retrieved 4 December 2018 Large scale removal of beachgrass leads to new life for endangered coastal lupine The Source Washington University in St Louis The Source 6 February 2018 Retrieved 9 June 2020 Hottentot Fig Removal amp Control IWS Ltd Invasive Weed Solutions UK Retrieved 9 June 2020 Miles J 1985 The pedogenic effects of different species and vegetation types and the implications of succession European Journal of Soil Science 36 4 571 584 doi 10 1111 j 1365 2389 1985 tb00359 x Geology of White Sands United States National Park Service Retrieved 20 January 2021 Franklin E M Charru F 2009 Morphology and displacement of dunes in a closed conduit flow Powder Technology 190 1 2 247 251 arXiv 1608 07729 doi 10 1016 j powtec 2008 04 065 S2CID 93576651 Franklin E M Charru F 2011 Subaqueous barchan dunes in turbulent shear flow Part 1 Dune motion Journal of Fluid Mechanics 675 199 222 Bibcode 2011JFM 675 199F doi 10 1017 S0022112011000139 S2CID 51792324 Cardona Florez Jorge Eduar Franklin Erick de Moraes 2016 The formation and migration of sand ripples in closed conduits Experiments with turbulent water flows Experimental Thermal and Fluid Science 71 95 102 arXiv 1608 04792 Bibcode 2016arXiv160804792E doi 10 1016 j expthermflusci 2015 10 017 S2CID 119268350 Prothero D R and Schwab F 1996 Sedimentary Geology pg 45 49 ISBN 0 7167 2726 9 Alvarez Carlos A Franklin Erick M 18 December 2017 Birth of a subaqueous barchan dune Physical Review E 96 6 062906 arXiv 1712 07162 Bibcode 2017PhRvE 96f2906A doi 10 1103 PhysRevE 96 062906 PMID 29347350 S2CID 25558699 Alvarez Carlos A Franklin Erick M 19 October 2018 Role of Transverse Displacements in the Formation of Subaqueous Barchan Dunes Physical Review Letters 121 16 164503 arXiv 1810 11074 Bibcode 2018PhRvL 121p4503A doi 10 1103 PhysRevLett 121 164503 PMID 30387641 S2CID 53231618 Ripples Archived from the original on 1 May 2018 Retrieved 11 January 2018 Grafals Soto Rosana 2012 Effects of sand fences on coastal dune vegetation distribution Geomorphology 145 146 45 55 Bibcode 2012Geomo 145 45G doi 10 1016 j geomorph 2011 12 004 Alexandria Coastal Dunefields UNESCO World Heritage Archived from the original on 18 November 2009 Retrieved 11 January 2010 Herring Cove Beach Cape Cod National Seashore U S National Park Service www nps gov Retrieved 29 July 2018 Race Point Beach Cape Cod National Seashore U S National Park Service www nps gov Retrieved 29 July 2018 Province Lands Bike Trail Cape Cod National Seashore U S National Park Service www nps gov Retrieved 29 July 2018 Mann D H Heiser P A Finney B P 2002 Holocene history of the Great Kobuk Sand Dunes Northwestern Alaska PDF Quaternary Science Reviews 21 4 709 731 Bibcode 2002QSRv 21 709M CiteSeerX 10 1 1 419 8948 doi 10 1016 S0277 3791 01 00120 2 Archived from the original PDF on 19 September 2015 Smith S amp Mark S 2006 Alice Gray Dorothy Buell and Naomi Svihla Preservationists of Ogden Dunes The South Shore Journal 1 Account Suspended Archived from the original on 13 September 2012 Retrieved 11 June 2012 Smith S amp Mark S 2009 The Historical Roots of the Nature Conservancy in the Northwest Indiana Chicagoland Region From Science to Preservation The South Shore Journal 3 Account Suspended Archived from the original on 1 January 2016 Retrieved 22 November 2015 Blvd Mailing Address 111 E Kellogg Paul Suite 105 Saint Us MN 55101 Phone 651 293 0200 This is the general phone line at the Mississippi River Visitor Center Contact Grey Cloud Dunes Scientific and Natural Area Mississippi National River amp Recreation Area U S National Park Service www nps gov Retrieved 21 April 2023 Tallest Sand Dunes in the World Surf the Sand 9 December 2020 Retrieved 9 December 2020 Mystery of world s tallest sand dunes solved 24 November 2004 New Scientist Archived 26 October 2008 at the Wayback Machine Big Mama highest dune Archived 2 September 2009 at the Wayback Machine Peeking Through the Haze Titan s Surface part II The Planetary Society Blog The Planetary Society Archived 28 April 2007 at the Wayback Machine Touponce William F 1988 Intellectual Background Frank Herbert Boston Twayne Publishers imprint G K Hall amp Co p 119 ISBN 978 0 8057 7514 3 Wright Les Forbidden Planet 1956 Culturevulture net Internet Archive Archived from the original on 7 May 2006 Retrieved 7 May 2006 Hladik Tamara I Classic Sci Fi Reviews Dune SciFi com Archived from the original on 20 April 2008 Retrieved 20 April 2008 Michaud Jon 12 July 2013 Dune Endures The New Yorker Retrieved 27 November 2013 Lynch Tom Glotfelty Cheryll Armbruster Karla 2012 The Bioregional Imagination Literature Ecology and Place University of Georgia Press p 230 ISBN 9780820343679 Star Wars is Dune D A Houdek Retrieved 1 October 2006 References EditBagnold Ralph 2012 1941 The Physics of Blown Sand and Desert Dunes Courier Dover Publications ISBN 978 0 486 14119 0 Further reading EditRalph Lorenz James Zimbelman 2014 Dune Worlds How Wind blown Sand Shapes Planetary Landscapes Springer ISBN 978 3 540 89724 8 Anthony J Parsons A D Abrahams ed 2009 Geomorphology of Desert Environments Springer ISBN 978 1 4020 5718 2 Pye Kenneth Tsoar Haim 2009 Aeolian Sand and Sand Dunes Springer ISBN 978 3 540 85909 3 Nouakchott Mauritania NASA Earth Observatory Archived from the original on 30 September 2006 Retrieved 28 April 2006 Badescu V Cathcart R B Bolonkin A A 2008 Sand dune fixation A solar powered Sahara seawater pipeline macroproject Land Degradation amp Development 19 6 676 691 doi 10 1002 ldr 864 S2CID 128961228 Summary Dunes Parabolic Desert Processes Working Group Knowledge Sciences Inc Archived from the original on 21 October 2010 Retrieved 6 October 2010 Fighting wind erosion One aspect of the combat against desertification Les dossiers thematiques du CSFD Archived from the original on 25 July 2011 Retrieved 4 January 2011 External links Edit Wikimedia Commons has media related to Dune category Loibor Seder Kenya s Biggest Sand Dune Coastal Sand Dunes Dune pattern identification U S Army The Bibliography of Aeolian Research Retrieved from https en wikipedia org w index php title Dune amp oldid 1151047688, wikipedia, wiki, book, books, library,

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