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{{short description|Hill of loose sand built by aeolian processes or the flow of water}}
{{for-multi|the fiction franchise|Dune (franchise){{!}}''Dune'' (franchise)||Dune (disambiguation)}}
{{Use British English|date=December 2018}}
{{Use dmy dates|date=December 2019}}
[[File:Rub al Khali 002.JPG|thumb|Sand dunes of the [[Empty Quarter]] to the east of [[Liwa Oasis]], United Arab Emirates]]

A '''dune''' is a [[landform]] composed of wind- or water-driven [[sand]]. It typically takes the form of a mound, ridge, or hill.<ref name="AGI-dune">{{cite book |editor1-last=Jackson |editor1-first=Julia A. |title=Glossary of geology. |date=1997 |publisher=American Geological Institute |location=Alexandria, Virginia |isbn=0-922152-34-9 |edition=Fourth |chapter=Dune [geomorph]}}</ref> An area with dunes is called a '''dune system'''<ref>{{cite encyclopedia |chapter-url=http://www.encyclopedia.chicagohistory.org/pages/394.html |access-date=15 January 2021 |chapter=Dune system |title=Encyclopedia of Chicago |last1=Pavlovic |first1=Noel B. |year=2005}}</ref><ref>{{cite web |url=https://www.biology-fieldwork.org/a-level/succession/sand-dunes/ |access-date=15 January 2021 |title=Sand dunes |website=Biology fieldwork |publisher=Field Studies Council |year=2016}}</ref><ref>{{cite web |url=https://www.michigan.gov/documents/deq/wrd-cda-dune-systems_558207_7.pdf |archive-url=https://web.archive.org/web/20170920225124/http://www.michigan.gov/documents/deq/wrd-cda-dune-systems_558207_7.pdf |archive-date=2017-09-20 |url-status=live |access-date=15 January 2021 |title=Dune systems |publisher=Michigan Department of Environmental Quality}}</ref><ref>{{cite web |url=https://www.restoconlife.eu/en/habitat-to-be-protected/the-dune-system/ |access-date=15 January 2021 |title=The dune system |website=Restoconlife |publisher=Parco Nazionale Arcipelago Toscano |year=2010 |archive-date=25 March 2023 |archive-url=https://web.archive.org/web/20230325133706/https://www.restoconlife.eu/en/habitat-to-be-protected/the-dune-system/ |url-status=usurped }}</ref> or a '''dune complex'''.{{sfn|Jackson|1997|loc="Dune complex"}} A large dune complex is called a '''dune field''',{{sfn|Jackson|1997|loc="Dune field"}} while broad, flat regions covered with wind-swept sand or dunes, with little or no vegetation, are called ''[[Erg (landform)|ergs]]'' or ''sand seas''.<ref>{{cite web |url=http://worldlandforms.com/landforms/erg/ |title=Erg Landforms |access-date=13 October 2019 |work=WorldLandForms}}</ref>{{sfn|Jackson|1997|loc="Erg"}}{{sfn|Jackson|1997|loc="Sand sea"}} Dunes occur in different shapes and sizes, but most kinds of dunes are longer on the [[wiktionary:stoss|stoss]] (upflow) side, where the sand is pushed up the dune, and have a shorter ''slip face'' in the lee side.{{sfn|Jackson|1997|loc="Slip face"}} The valley or trough between dunes is called a ''dune slack''.<ref>{{cite book |editor1-last=Allaby |editor1-first=Michael |title=A dictionary of geology and earth sciences |date=2008 |publisher=Oxford University Press |location=Oxford |isbn=978-0-19-965306-5 |edition=Fourth |chapter=Dune slack}}</ref>

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 [[Outwash plain|glacial outwash]], and in other areas where poorly cemented [[sandstone]] bedrock disintegrates to produce an ample supply of loose sand.<ref name="thornbury-1969">{{cite book |last1=Thornbury |first1=William D. |title=Principles of geomorphology |date=1969 |publisher=Wiley |location=New York |isbn=0-471-86197-9 |pages=288–302 |edition=2d}}</ref> Subaqueous dunes can form from the action of water flow ([[fluvial]] processes) on sand or [[gravel]] beds of [[river]]s, [[estuary|estuaries]], and the sea-bed.<ref name="oxford">{{cite dictionary |last1=Fowler |first1=H.W. |author-link=H. W. Fowler |last2=Fowler |first2=F.G. |author2-link=F. G. Fowler |editor-last=Sykes |editor-first=J.B. |title=The Concise Oxford Dictionary of Current English |title-link=The Concise Oxford Dictionary of Current English |year=1984 |publisher=[[Clarendon Press]] |location=Oxford |isbn=978-0-19-861132-5 |edition=7th}}</ref>{{sfn|Jackson|1997|loc="Dune [streams]"}}

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]].<ref>{{Cite journal |last1=McClelland |first1=Mac | url=https://www.audubon.org/magazine/march-april-2015/slip-sliding-away |title = Slip Sliding Away|date = March 2015 |journal=[[Audubon (magazine)|Audubon]] |volume=348 |issue=6239 |page=1102 |bibcode=2015Sci...348.1102L }}</ref> Artificial dunes are sometimes constructed to protect coastal areas.<ref>{{cite news |url=https://www.telegraph.co.uk/expat/expatnews/6613101/Dutch-construct-dunes-against-rising-seas.html |archive-url=https://ghostarchive.org/archive/20220111/https://www.telegraph.co.uk/expat/expatnews/6613101/Dutch-construct-dunes-against-rising-seas.html |archive-date=11 January 2022 |url-status=live |access-date=15 January 2021 |title=Dutch construct dunes against rising seas |first1=Alix |last1=Rijckaert |date=20 November 2009 |periodical=The Telegraph |url-access=registration}}{{cbignore}}</ref><ref>{{cite web |url=https://www.ctc-n.org/sites/www.ctc-n.org/files/UNFCCC_docs/ref18x43_35.pdf |archive-url=https://web.archive.org/web/20191117121521/https://www.ctc-n.org/sites/www.ctc-n.org/files/UNFCCC_docs/ref18x43_35.pdf |archive-date=2019-11-17 |url-status=live |access-date=15 January 2021 |publisher=UNET DTU Partnership |title=Artificial Sand Dunes and Dunes Rehabilitation |date=14 June 2018}}</ref> 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.<ref>[http://members.iinet.net.au/~oseagram/eucla.html The intercolonial telegraph line at Eucla], accessed 1 April 2007.</ref>

The modern word "dune" came into English from French around 1790,<ref>{{cite dictionary |url=http://www.dictionary.com/browse/dune |title=Dune—Define Dune |dictionary=[[Dictionary.com]] |access-date=1 May 2018 |publisher=[[Dictionary.com, LLC]]}}</ref> which in turn came from [[Middle Dutch]] ''dūne''.<ref name="oxford"/>{{TOC limit}}

==Formation==
[[File:Saltation on sand dune.png|thumb|upright=1.25|Sand hitting sand is more likely to stick; sand hitting a more coherent surface is more likely to bounce ([[saltation (geology)|saltation]]). This exacerbating [[feedback loop]] helps sand accumulate into dunes.]]

A universally precise distinction does not exist between ripples, dunes, and [[#Draa|draas]],<ref name="Leeder2012">{{cite book|author=M.R. Leeder|title=Sedimentology: Process and Product|url=https://books.google.com/books?id=CUTvCAAAQBAJ&pg=PA97|date=6 December 2012|publisher=Springer Science & Business Media|isbn=978-94-009-5986-6|pages=97–}}</ref> which are all deposits of the same type of materials. Dunes are generally defined as greater than 7&nbsp;cm tall and may have ripples, while ripples are deposits that are less than 3&nbsp;cm tall.<ref name="PettijohnPotter2012">{{cite book|author1=F. J. Pettijohn|author2=P. E. Potter|author3=R. Siever|title=Sand and Sandstone|url=https://books.google.com/books?id=FFEyBwAAQBAJ&pg=PA346|date=6 December 2012|publisher=Springer Science & Business Media|isbn=978-1-4615-9974-6|pages=346–}}</ref> A draa is a very large aeolian landform, with a length of several kilometers and a height of tens to hundreds of meters, and which may have superimposed dunes.{{sfn|Jackson|1997|loc="Draa"}}

{{anchor|Slip face}}
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 (geology)|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).<ref name="USG Types of Dunes"/>

====Barchan or crescentic====
{{main|barchan}}
[[File:Barchan in Noachis.jpg|thumbnail|right|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).<ref name=dkp>{{cite book|title=The Ultimate Visual Family Dictionary|chapter=Geology, Geography, and Meteorology|pages=282–283|publisher=[[DK (publisher)|D.K. Pub.]]|year=2012|location=New Delhi|language=en|isbn=978-0-1434-1954-9}}</ref> 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).<ref name=Mangimeli/>

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 (Egypt)|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]].<ref name="USG Types of Dunes">{{cite web|title=Types of Dunes|url=https://pubs.usgs.gov/gip/deserts/dunes/|access-date=8 March 2012|url-status=live|archive-url=https://web.archive.org/web/20120314161113/http://pubs.usgs.gov/gip/deserts/dunes/|archive-date=14 March 2012 |publisher=[[U.S. Geological Survey]] |date=29 October 1997}}</ref>

====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.<ref name=Mangimeli/><ref name=dkp/>

====Seif or longitudinal dunes====
<!--[[Seif dune]] redirects here-->
Seif dunes are linear (or slightly sinuous) dunes with two slip faces. The dunes lie generally parallel to each other<ref name=Mangimeli/><ref name=dkp/> 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").<ref name=seif_terminology>{{cite book |doi=10.1007/978-1-4614-9213-9_460-2 |chapter=Longitudinal Dunes (or Linear Dunes) |title=Encyclopedia of Planetary Landforms |pages=1–11 |year=2014 |last1=Radebaugh |first1=Jani |last2=Sharma |first2=Priyanka |last3=Korteniemi |first3=Jarmo |last4=Fitzsimmons |first4=Kathryn E. |isbn=978-1-4614-9213-9 }}</ref> Some linear dunes merge to form Y-shaped compound dunes.<ref name="USG Types of Dunes"/>

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 [[vortex|vortices]] in a unidirectional wind.<ref name=Mangimeli/> In the sheltered troughs between highly developed seif dunes, barchans may be formed, because the wind is constrained to be unidirectional by the dunes.

<!-- The first image (Rub' al Khali) would be better rotated 90 degrees clockwise to match it with the contrasting image to the right --> 
<gallery mode="packed" heights="150">
File:Rub' al Khali (Arabian Empty Quarter) sand dunes imaged by Terra (EOS AM-1).jpg|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.
File:ISS-31 Linear dunes in the Great Sand Sea in southwest Egypt.jpg|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&nbsp;km.
File:Longitudinal_dune.jpg|The average-direction-longitudinal model of seif dune formation
File:Tranverse dune.jpg|alt=Transverse dune with wind blowing across crest|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.
File:Cross-bedding.gif|alt=Animation of wind pushing transverse dunes along. The sand blows from the stoss side down onto the less side, where it is buried by the next layer. The dune thus moves, and a cross-section through it shown diagonal cross-bedding|Transverse dunes lie perpendicular to the wind, which moves them forwards, producing the [[cross-bedding]] shown here.
</gallery>

Seif dunes are common in the Sahara. They range up to {{convert|300|m|ft|abbr=on}} in height and {{convert|300|km|mi|abbr=on}} in length. In the southern third of the Arabian Peninsula, a vast [[Erg (landform)|erg]], called the [[Rub' al Khali]] or Empty Quarter, contains seif dunes that stretch for almost {{convert|200|km|mi|abbr=on}} and reach heights of over {{convert|300|m|ft|abbr=on}}.

Linear [[loess]] hills known as [[paha (landform)|pahas]] are superficially similar. These hills appear to have been formed during the last [[Quaternary glaciation|ice age]] under [[permafrost]] conditions dominated by sparse [[tundra]] vegetation.

====Star====
[[File:Elk and Star Dune (49097789642).jpg|thumb|Star dunes with a rough pyramidal shape and ridges at [[Great Sand Dunes National Park and Preserve]]]]
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.<ref name=dkp/> 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 sea]]s, 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 [[Dry lake|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&nbsp;km long, 1&nbsp;km wide, and up to 50 metres high. They also occur in [[Southern Africa|southern]] and [[West Africa]], and in parts of the western United States, especially Texas.<ref>[[Charles Rowland Twidale|Twidale, C.R.]] & 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}}</ref>

====Parabolic====
[[File:Parabolic dune.jpg|thumb|upright=1.5|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&nbsp;km. Sometimes these dunes are called U-shaped, [[blowout (geology)|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 [[soil]]s. 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&nbsp;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''.<ref>{{cite book|last=Goudie|first=Ron Cooke; Andrew Warren; Andrew|title=Desert geomorphology|year=1996|publisher=UCL Press|location=London|isbn=978-1-85728-017-3|pages=395–396|edition=2. impr.}}</ref> The term zibar comes from the [[Arabic]] word to describe "rolling transverse ridges ... with a hard surface".<ref>{{cite book|last=Goudie|first=Ron Cooke; Andrew Warren; Andrew|title=Desert geomorphology|year=1996|publisher=UCL Press|location=London|isbn=978-1-85728-017-3|page=395|edition=2. impr.}}</ref> 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.<ref>{{Cite FTP |title=USGS Landform Glossary|url=ftp://ftp-fc.sc.egov.usda.gov/NSSC/Soil_Survey_Handbook/629_glossary.pdf|server=United States Geological Survey|url-status=dead|access-date=3 October 2013}}</ref> Spacing between zibars ranges from 50 to 400 metres and they do not become more than 10 metres high.<ref>{{cite journal |last1=Warren |first1=A. |title=Dunes in the Tenere Desert |journal=The Geographical Journal |date=December 1971 |volume=137 |issue=4 |pages=458–461 |doi=10.2307/1797141|jstor=1797141 |bibcode=1971GeogJ.137..458W }}</ref> 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.<ref>{{cite journal |last1=Nielson |first1=Jamie |last2=Kocurek |first2=Gary |title=Climbing Zibars of the Algodones |journal=Sedimentary Geology |date=June 1986 |volume=48 |issue=1–2 |pages=1–15 |doi=10.1016/0037-0738(86)90078-3|bibcode=1986SedG...48....1N }}</ref>

====Reversing dunes====
[[File:Libya 4608 Idehan Ubari Dunes Luca Galuzzi 2007.jpg|thumb|left|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.<ref name=Mangimeli/>

{{anchor|Draa}}

====Draas====
[[File:350m Düne Deadvlei Sossusvlei.JPG|thumb|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.<ref name=Mangimeli>{{cite web| publisher = U.S.A. National Park Service| last = Mangimeli| first = John| title = Geology of Sand Dunes| date = 10 September 2007 |url=https://home.nps.gov/whsa/learn/nature/loader.cfm?csModule=security/getfile&PageID=2033934 |access-date=15 January 2021}}</ref> After a draa has reached a certain size, it generally develops superimposed dune forms.<ref name=Lancaster>{{cite journal|title=The development of large aeolian bedforms|first=N.|last=Lancaster|date=1 March 1988|journal=Sedimentary Geology|volume=55|issue=1–2|pages=69–89|doi=10.1016/0037-0738(88)90090-5|bibcode=1988SedG...55...69L}}</ref> They are thought to be more ancient and slower-moving than smaller dunes,<ref name=Mangimeli/> and to form by vertical growth of existing dunes. Draas are widespread in sand seas and are [[Cross-bedding|well-represented in the geological record]].<ref name=Lancaster/>

===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).<ref name="USG Types of Dunes"/> 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.<ref>{{Cite journal|last1=Jiang|first1=Hong|last2=Dun|first2=Hongchao|last3=Tong|first3=Ding|last4=Huang|first4=Ning|date=15 April 2017|title=Sand transportation and reverse patterns over leeward face of sand dune|journal=Geomorphology|volume=283|pages=41–47|doi=10.1016/j.geomorph.2016.12.030|bibcode=2017Geomo.283...41J}}</ref>

===Coastal dunes===
[[File:LIVER AAS UDLOEB I JULI 2012 (ubt)-002.JPG|thumb|Coastal dunes covered in grasses around the mouth of the Liver Å river in Denmark]]
[[File:Newborough Dune Rejuvenation.webm|thumb|Newborough Dune Rejuvenation, Wales; video of work done by [[Natural Resources Wales]]; 2015]]

Coastal dunes<ref name="sloss-etal-2012">{{Cite journal |url=https://www.nature.com/scitable/knowledge/library/coastal-dunes-geomorphology-25822000/ |last1=Sloss |first1=C. R. |last2=Shepherd |first2=M. |last3=Hesp |first3=P |year=2012 |title=Coastal Dunes: Geomorphology |journal=Nature Education Knowledge |volume=3 |number=10 |page=2  |access-date=15 January 2021}}</ref> form when wet sand is deposited along the coast and dries out and is blown along the beach.<ref>{{cite book |last1=Bird |first1=ECF |title=Coasts: an introduction to systematic geomorphology |date=1976 |publisher=Australian National University Press |location=Canberra, Australia |asin=B004750SVK}}</ref> 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.<ref>{{cite book |last1=Goldsmith |first1=Victor |title=Coastal Sedimentary Environments |chapter=Coastal Dunes |date=1978 |doi=10.1007/978-1-4684-0056-4_5 |pages=171–235|isbn=978-1-4684-0058-8 }}</ref> Obstacles—for example, vegetation, pebbles and so on—tend to slow down the wind and lead to the deposition of sand grains.<ref name=Hesp1989>{{Cite journal| last = Hesp | first = P.| year = 1989| title = A review of biological and geomorphological processes involved in the initiation and development of incipient foredunes| journal = Proceedings of the Royal Society of Edinburgh, Section B: Biological Sciences| volume = 96| pages = 181–201| doi =  10.1017/S0269727000010927 }}</ref> 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]].<ref>{{Cite journal|last=Godfrey|first=P. J.|date=1 September 1977|title=Climate, plant response and development of dunes on barrier beaches along the U.S. east coast|journal=International Journal of Biometeorology|volume=21|issue=3|pages=203–216|doi=10.1007/BF01552874|issn=0020-7128|bibcode=1977IJBm...21..203G|s2cid=85391018}}</ref><ref>{{Cite journal|last1=Goldstein|first1=Evan B.|last2=Moore|first2=Laura J.|last3=Vinent|first3=Orencio Durán|date=8 August 2017|title=Lateral vegetation growth rates exert control on coastal foredune "hummockiness" and coalescing time|journal=Earth Surface Dynamics|volume=5|issue=3|pages=417–427|doi=10.5194/esurf-5-417-2017|issn=2196-6311|doi-access=free}}{{open access}}</ref> Models of coastal dunes suggest that their final equilibrium height is related to the distance between the water line and where vegetation can grow.<ref name=DuranMoore2013>{{Cite journal| last1 = Durán | first1 = O.| last2=Moore|first2= L. J. |year = 2013| title = Vegetation controls on the maximum size of coastal dunes| journal = Proceedings of the National Academy of Sciences| volume = 110 | issue = 43 |  pages = 17217–17222| doi =  10.1073/pnas.1307580110 | pmid=24101481 | pmc=3808624| bibcode = 2013PNAS..11017217D| doi-access = free}}</ref> 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.<ref name="sloss-etal-2012"/> 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.<ref>{{cite journal |last1=Houser |first1=C |last2=Hapke |first2=C |last3=Hamilton |first3=S |title=Controls on coastal dune morphology, shoreline erosion and barrier island response to extreme storms |journal=Geomorphology |date=15 August 2008 |volume=100 |issue=3–4 |pages=223–40|doi=10.1016/j.geomorph.2007.12.007 |bibcode=2008Geomo.100..223H }}</ref><ref>{{cite journal |last1=Claudino-Sales |first1=V |last2=Wang |first2=P |last3=Horwitz |first3=MH |title=Factors controlling the survival of coastal dunes during multiple hurricane impacts in 2004 and 2005: Santa Rosa Barrier Island, Florida |journal=Geomorphology |date=15 March 2008 |volume=95 |issue=3–4 |pages=295–315|doi=10.1016/j.geomorph.2007.06.004 |bibcode=2008Geomo..95..295C }}</ref> 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.<ref>{{cite web |last1=Ronica |first1=D |title=How sand dunes work |url=https://science.howstuffworks.com/environmental/earth/geology/sand-dune3.htm |website=HowStuffWorks |access-date=4 December 2018|date=27 October 2008 }}</ref> 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.<ref>{{cite web |last1=Hill |first1=K |title=Dune Habitats |url=https://naturalhistory2.si.edu/smsfp/IRLSpec/Dunes.htm |website=Smithsonian Marine Station |access-date=4 December 2018}}</ref> 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 cyclone]]s 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.<ref>{{Cite journal|last1=Durán Vinent|first1=Orencio|last2=Moore|first2=Laura|date=February 2015|title=Barrier island bistability induced by biophysical interactions|journal=Nature Climate Change|volume=5|issue=2|pages=158–162|doi=10.1038/nclimate2474|issn=1758-6798|bibcode=2015NatCC...5..158D|url=https://cdr.lib.unc.edu/downloads/1257b286c}}</ref><ref>{{Cite journal|last1=Goldstein|first1=Evan B.|last2=Moore|first2=Laura J.|date=2016|title=Stability and bistability in a one-dimensional model of coastal foredune height|journal=Journal of Geophysical Research: Earth Surface|volume=121|issue=5|pages=964–977|doi=10.1002/2015JF003783|issn=2169-9011|bibcode=2016JGRF..121..964G|doi-access=free}}</ref> 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.<ref>{{cite journal |last1=Morton |first1=RA |title=Effects of Hurricane Eloise on beach and coastal structures, Florida Panhandle |journal=Geology |date=1 May 1976 |volume=4 |issue=5 |pages=277–80|doi=10.1130/0091-7613(1976)4<277:EOHEOB>2.0.CO;2 |bibcode=1976Geo.....4..277M }}</ref> 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.<ref>{{cite journal |last1=Charbonneau |first1=B |last2=Wnek |first2=JP |title=Reactionary fence installation for post-Superstorm Sandy dune recovery |url=https://eartharxiv.org/ntjsc |journal=Eartharxiv ePrints |date=24 September 2018 |doi=10.31223/osf.io/ntjsc |bibcode=2018EaArX....NTJSCC |access-date=4 December 2018 |archive-date=30 July 2020 |archive-url=https://web.archive.org/web/20200730053248/https://eartharxiv.org/ntjsc |doi-access=free }}</ref>

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.<ref>{{cite web |last1=Maine Sea Grant |title=Seasonal changes |url=https://www.seagrant.umaine.edu/coastal-hazards-guide/beaches-and-dunes/learn-more/seasonal-changes |website=Maine Sea Grant College Program |access-date=4 December 2018 |archive-url=https://web.archive.org/web/20181205003653/https://www.seagrant.umaine.edu/coastal-hazards-guide/beaches-and-dunes/learn-more/seasonal-changes |archive-date=5 December 2018 }}</ref>

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|Point Reyes, California]]. There are now efforts to get rid of both of these invasive species.<ref>{{Cite web|date=2018-02-06|title=Large-scale removal of beachgrass leads to new life for endangered coastal lupine {{!}} The Source {{!}} Washington University in St. Louis|url=https://source.wustl.edu/2018/02/large-scale-removal-beachgrass-leads-new-life-endangered-coastal-lupine/|access-date=2020-06-09|website=The Source|language=en-US}}</ref><ref>{{Cite web|title=Hottentot Fig Removal & Control {{!}} IWS Ltd|url=https://www.invasiveweedsolutions.co.uk/invasive-weeds/non-native/hottentot-fig/|access-date=2020-06-09|website=Invasive Weed Solutions UK|language=en-GB}}</ref>

====Ecological succession on coastal dunes====
As a dune forms, plant [[Ecological succession|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 [[Ammophila (Poaceae)|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 [[Calluna|heather]], [[Heath (habitat)|heath]]s and [[gorse]]s. These too are adapted to the low [[Soil#Soil moisture|soil water]] content and have small, prickly leaves which reduce transpiration. Heather adds [[humus]] to the soil and is usually replaced by [[conifer]]ous trees, which can tolerate low [[soil pH]], caused by the accumulation and decomposition of organic matter with nitrate leaching.<ref name=Miles1985>{{Cite journal| last = Miles | first = J.| year = 1985| title = The pedogenic effects of different species and vegetation types and the implications of succession| journal = European Journal of Soil Science| volume = 36| issue = 4| pages = 571–584| doi = 10.1111/j.1365-2389.1985.tb00359.x| bibcode = 1985EuJSS..36..571M}}</ref> Coniferous forests and [[heathland]] are common [[climax community|climax communities]] for sand dune systems.

Young dunes are called [[yellow dune]]s and dunes which have high humus content are called [[grey dune]]s. 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 toad]]s sometimes breed here.

==== Coastal dune floral adaptations ====
[[File:Hyypänmäki Hailuoto 2012-06-06 (1).jpg|thumb|Sand dunes of Hyypänmäki in [[Hailuoto]], Finland]]
[[File:Sea dune Erosion at Talace, Wales.webm|thumb|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 ([[Abronia umbellata|Pink Sand Verbena]])
* Shallow but extensive root systems
*[[Rhizome]]s
* 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===
[[File:Aerial view of dunefield, White Sands National Park, New Mexico, United States.png|thumb|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 (mineral)|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.<ref>{{cite web |url=https://www.nps.gov/whsa/learn/geology-of-white-sands.htm |title=Geology of White Sands|publisher=United States National Park Service|access-date=20 January 2021}}</ref>

===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.

==Subaqueous dunes==
[[File:Cross-section of Migrating Subaqueous Dunes.jpg|thumb|Idealized cross-section of sets of cross-bedding left behind by migrating subaqueous dunes in unidirectional current]]
{{main|Ripple marks}}
Subaqueous ([[underwater]]) dunes form on a bed of sand or gravel under the actions of water flow. They are ubiquitous in natural [[Channel (geography)|channels]] such as rivers and estuaries, and also form in engineered [[canal]]s and pipelines.<ref>{{cite journal |doi=10.1016/j.powtec.2008.04.065 |title=Morphology and displacement of dunes in a closed-conduit flow |journal=Powder Technology |volume=190 |issue=1–2 |pages=247–251 |year=2009 |last1=Franklin |first1=E.M. |last2=Charru |first2=F. |arxiv=1608.07729 |s2cid=93576651 }}</ref><ref>{{cite journal |doi=10.1017/S0022112011000139 |title=Subaqueous barchan dunes in turbulent shear flow. Part 1. Dune motion |journal=Journal of Fluid Mechanics |volume=675 |pages=199–222 |year=2011 |last1=Franklin |first1=E. M. |last2=Charru |first2=F. |bibcode=2011JFM...675..199F |s2cid=51792324 }}</ref><ref>{{cite journal |doi=10.1016/j.expthermflusci.2015.10.017 |title=The formation and migration of sand ripples in closed conduits: Experiments with turbulent water flows |journal=Experimental Thermal and Fluid Science |volume=71 |pages=95–102 |year=2016 |last1=Cardona Florez |first1=Jorge Eduar |last2=Franklin |first2=Erick de Moraes |arxiv=1608.04792 |bibcode=2016ETFS...71...95C |s2cid=119268350 }}</ref> Dunes move downstream as the upstream slope is eroded and the sediment deposited on the downstream or lee slope in typical [[bedform]] construction.<ref>Prothero, D. R. and Schwab, F., 1996, ''[[Sedimentary Geology (journal)|Sedimentary Geology]]'', pg. 45–49, {{ISBN|0-7167-2726-9}}</ref> In the case of subaqueous barchan dunes, sediment is lost by their extremities, known as horns.<ref>{{Cite journal|last1=Alvarez|first1=Carlos A.|last2=Franklin|first2=Erick M.|date=18 December 2017|title=Birth of a subaqueous barchan dune|journal=Physical Review E|volume=96|issue=6|article-number=062906|doi=10.1103/PhysRevE.96.062906|pmid=29347350|arxiv=1712.07162|bibcode=2017PhRvE..96f2906A|s2cid=25558699}}</ref><ref>{{Cite journal|last1=Alvarez|first1=Carlos A.|last2=Franklin|first2=Erick M.|date=19 October 2018|title=Role of Transverse Displacements in the Formation of Subaqueous Barchan Dunes|journal=Physical Review Letters|volume=121|issue=16|article-number=164503|doi=10.1103/PhysRevLett.121.164503|pmid=30387641|arxiv=1810.11074|bibcode=2018PhRvL.121p4503A|s2cid=53231618}}</ref>

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.<ref>{{cite web |url=https://www4.uwm.edu/course/geosci697/ripple-indices/Ripple%20Indices.html |title=Ripples |access-date=11 January 2018 |url-status=live |archive-url=https://web.archive.org/web/20180501201547/https://www4.uwm.edu/course/geosci697/ripple-indices/Ripple%20Indices.html |archive-date=1 May 2018  }}</ref> 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==
[[File:Cross-bedding Of Sandstone Near Mt Carmel Road Zion Canyon Utah.jpg|thumb|Cross-bedding in lithified aeolian sand dunes preserved as sandstone in Zion National Park, Utah]]
A [[Lithification|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 colour of the rock. [[Cross-bedding|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 [[Southwestern United States|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.<ref>{{Cite book |title=Toward a sociology of the trace |date=2010 |publisher=University of Minnesota Press |isbn=978-0-8166-5597-7 |editor-last=Gray |editor-first=Herman |location=Minneapolis, Minn |pages=197–198 |editor-last2=Gómez-Barris |editor-first2=Macarena}}</ref>

==Desertification==
{{Main|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 (geology)|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 (sand dunes)|creep]]. With slightly stronger winds, particles collide in mid-air, causing [[sheet flow]]s. In a major [[dust storm]], dunes may move tens of metres through such sheet flows. Also as in the case of snow, sand [[avalanche]]s, 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 fence]]s might also slow their movement to a crawl, but geologists are still analyzing results for the optimum fence designs.<ref>{{Cite journal|last=Grafals-Soto|first=Rosana|title=Effects of sand fences on coastal dune vegetation distribution|journal=Geomorphology|year=2012|language=en|volume=145-146|pages=45–55|doi=10.1016/j.geomorph.2011.12.004|bibcode=2012Geomo.145...45G}}</ref> 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==
[[File:KelsoSand.JPG|thumb|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===
[[File:Düne S-Schlag Sossusvlei.JPG|thumb|A dune in [[Sossusvlei]], in the greater [[Namib-Naukluft National Park]], Namibia. Note the trees being engulfed for scale.]]
[[File:Sand dune in the Kalahari Desert (Namibia).jpg|thumb|[[Vachellia erioloba|Camelthorn]] trees and bushes scattered on dunes in the [[Kalahari Desert]] in Namibia (2017)]]
[[File:Sand dunes, Libyan Desert, Dakhla Oasis, Egypt.jpg|thumb|Sand dune in the [[Libyan Desert]] near [[Dakhla Oasis]] at sunset.]]
* [[Alexandria Coastal Dunefields]], in the [[Eastern Cape]], [[South Africa]]<ref name="unesco-alexandriadunes">{{cite web|url=https://whc.unesco.org/en/tentativelists/5453/|title=Alexandria Coastal Dunefields|publisher=[[World Heritage Site|UNESCO World Heritage]]|access-date=11 January 2010|url-status=live|archive-url=https://web.archive.org/web/20091118220211/https://whc.unesco.org/en/tentativelists/5453/|archive-date=18 November 2009}}</ref>
* 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]]
* [[Chad Basin National Park]] in northern [[Nigeria]]
* The coastal dunes of [[Iona National Park]] in the southwesternmost part of [[Angola]]
* [[Khawa, Botswana|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|Lompoul Desert]] in northwestern [[Senegal]]
* The coastal dunes of [[Bazaruto Island]], [[Mozambique]]
* [[Djurab Desert|Erg du Djourab]] in northern [[Chad]]
* The dunes of the [[Mourdi Depression]] in northeastern [[Chad]]
* The dunes of [[Termit Massif Reserve|Tin Toumma Desert]], in southeastern [[Niger]]
* [[Great Bilma Erg|Grand Erg de Bilma]] in the [[Ténéré]], in northern [[Niger]]
* The dunes of [[Oursi Department|Oursi]] in the [[Sahel Region]], northern [[Burkina Faso]]
* [[Tanzania]]'s Shifting Sands near [[Olduvai Gorge]]

[[File:1969 Afghanistan (Sistan) wind ripples.tiff|thumb|upright|Wind ripples on crescent-shaped sand dunes (barchans) in southwest [[Afghanistan]] ([[Sistan]])]]

===Asia===
* Sunset view dunes in the Alankuda village on [[Kalpitiya Peninsula|Kalpitiya peninsula]] in [[Sri Lanka]].<ref>{{Cite web |title=Sand Dune · 3PF5+CXG, Etalai, Sri Lanka |url=https://www.google.com/maps/place/Sand+Dune/@8.073306,79.7084833,17z/data=!4m5!3m4!1s0x0:0x57dd140727bb048a!8m2!3d8.0735645!4d79.7099652?shorturl=1 |access-date=2024-02-19 |website=Sand Dune · 3PF5+CXG, Etalai, Sri Lanka |language=en}}</ref>
* 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]].
* [[Dasht-e Lut|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]].
* Lautan Pasir, a volcanic dune in [[Bromo Tengger Semeru National Park]], Indonesia.
* Mui Ne, Vietnam.
* [[Sharqiya Sands]], [[Oman]]
* [[Teri (geology)|Teri]], red dune complex in southern India
*  The dunes of the [[Taklamakan Desert]] in southwest [[Xinjiang]] in [[Northwest China]]
*[[Tukulan]]s of the [[Central Yakutian Lowland]], Russia

[[File:Mediterranean Sea in Oliva, Valencia Region of the Spain 01.JPG|thumb|Fronting the Mediterranean Sea in [[Oliva]], Valencian Community, Spain]]

===Europe===
[[File:Duna de Salir do Porto - Portugal (267165155).jpg|thumb|right|{{convert|50|m|ft|abbr=on}} tall dune in [[Salir do Porto]], Portugal]]
[[File:Lemnosdesert.jpg|thumb|Sand dunes of Lemnos, Greece]]
* The [[Dyuni|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 [[Arbus, Sardinia|Dunes of Piscinas]], in the south west of [[Sardinia]] island.
* [[Forvie National Nature Reserve|Sands of Forvie]] within the [[Ythan Estuary]] complex, [[Aberdeenshire]], [[Scotland]].
* [[Oxwich Bay|Oxwich Dunes]], near [[Swansea]], is on the [[Gower Peninsula]] in [[Wales]].
* [[Winterton Dunes]] – [[Norfolk]], [[England]]
* [[Słowiński National Park]], [[Poland]]
*[[Siedlec Desert]], Poland
*[[Starczynów Desert]], now mostly forested dunes, Poland
* [[Pachies Ammoudies of Lemnos|Sand dunes of Lemnos]], [[Lesbos Prefecture]], [[Greece]]
* [[Akrotiri Peninsula (Cyprus)|Akrotiri]] Sand Dune, [[Limassol District|Lemesos]], [[Cyprus]]
* [[Råbjerg mile]], [[Northern Jutland]], [[Denmark]]
* [[Thy National Park]], [[North Denmark Region]], [[Denmark]]
* [[The Dunes of Corrubedo Natural Park|Dunes of Corrubedo]], [[Spain]]
* [[Cresmina Dune]], [[Portugal]]
* [[Northern Littoral Natural Park]], [[Portugal]]
* [[Salir do Porto|Dune of Salir]], [[Portugal]]
* [[São Jacinto Dunes Natural Reserve]], [[Portugal]]
* Rëra e Hedhur in [[Shëngjin]], [[Albania]]
* [[De Hoge Veluwe National Park]], [[Veluwe]], [[Netherlands]]
* [[Kootwijk]]erzand, Veluwe, Netherlands, 7&nbsp;km<sup>2</sup>
* [[Dunes of Texel National Park]], [[Texel]], Netherlands
* [[Zuid-Kennemerland National Park]], [[North Holland]], Netherlands
* [[Berkheide]], 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 system

===North America===
[[File:Guadalupe Dunes County Park road.JPG|thumb|[[Guadalupe-Nipomo Dunes]]]]
[[File:My Public Lands Roadtrip- Cadiz Dunes Wilderness in California (18720555819).jpg|thumb|[[Cadiz Dunes Wilderness]], [[California]]]]
[[File:CroneseCat.JPG | thumb | Cat Dune, [[Cronese Mountains]], California]]
==== Canada ====
* Victoria Island Sand Dunes,160&nbsp;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.
* The Athabasca Sand Dunes, located in the [[Athabasca Sand Dunes Provincial Park]], [[Saskatchewan]].
* [[Carcross Desert]] near [[Carcross, Yukon]]

==== United States ====

* Alaska:
** [[Nogahabara Sand Dunes]] in western [[Alaska]].<ref>{{Cite web |last=Rozell |first=Ned |date=September 22, 2022 |title=Alaska sand dunes hint at ancient past |url=https://www.uaf.edu/news/alaska-sand-dunes-hint-at-ancient-past.php |url-status=live |archive-url=https://web.archive.org/web/20221007025820/https://www.uaf.edu/news/alaska-sand-dunes-hint-at-ancient-past.php |archive-date=October 7, 2022 |access-date=July 27, 2024 |website=University of Alaska Fairbanks}}</ref>
** Great Kobuk Sand Dunes, [[Kobuk Valley National Park]], [[Alaska]]<ref name="qsr">{{cite journal |last1=Mann |first1=D. H. |last2=Heiser |first2=P. A. |last3=Finney |first3=B. P. |year=2002 |title=Holocene history of the Great Kobuk Sand Dunes, Northwestern Alaska |url=http://www.lter.uaf.edu/pdf/921_Mann_Heiser_2002.pdf |journal=Quaternary Science Reviews |volume=21 |issue=4 |pages=709–731 |bibcode=2002QSRv...21..709M |citeseerx=10.1.1.419.8948 |doi=10.1016/S0277-3791(01)00120-2 |archive-url=https://web.archive.org/web/20150919202606/http://www.lter.uaf.edu/pdf/921_Mann_Heiser_2002.pdf |archive-date=19 September 2015}}</ref>
* California:
**The [https://web.archive.org/web/20160817155504/http://www.blm.gov/ca/st/en/fo/needles/wilderness/cadiz_dunes.html Cadiz Dunes] in the [https://web.archive.org/web/20160216044509/http://www.blm.gov/ca/st/en/prog/nlcs/Mojave_Trails.html Mojave Trails National Monument] in [[California]].
** The [[Kelso Dunes]] in the [[Mojave Desert]] of [[California]].
**[[Eureka Valley Sand Dunes]] and [[Places of interest in the Death Valley area#Mesquite Flat Sand Dunes|Mesquite Flat Sand Dunes]] in [[Death Valley National Park]], [[California]].
**[[Algodones Dunes]] near [[Brawley, California]].
**[[Guadalupe-Nipomo Dunes]], on the central coast of [[California]].
**Cat Dune in the [[Cronese Mountains]] is a rare type of dune called a ''sand ramp''.
*[[Great Sand Dunes National Park]], [[Colorado]].
*The Great Dune found in [[Cape Henlopen State Park]] in [[Lewes, Delaware]].
*[[Bruneau Dunes State Park]] – [[Owyhee Desert]], [[Idaho]]
*[[Indiana Dunes National Park]], [[Indiana]], on the south shore of [[Lake Michigan]].<ref>Smith, S. & Mark, S. (2006). Alice Gray, Dorothy Buell, and Naomi Svihla: "Preservationists of Ogden Dunes". ''The South Shore Journal'', 1.
{{cite web |title=Account Suspended |url=http://www.southshorejournal.org/index.php/issues/volume-1-2006/78-journals/vol-1-2006/117-alice-gray-dorothy-buell-and-naomi-svihla-preservationists-of-ogden-dunes |archive-url=https://web.archive.org/web/20120913013557/http://www.southshorejournal.org/index.php/issues/volume-1-2006/78-journals/vol-1-2006/117-alice-gray-dorothy-buell-and-naomi-svihla-preservationists-of-ogden-dunes |archive-date=13 September 2012 |access-date=11 June 2012}}
</ref><ref>Smith, S. & 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. {{cite web |title=Account Suspended |url=http://www.southshorejournal.org/index.php/issues/volume-3-2009/83-journals/vol-3-2009/75-the-historical-roots-of-the-nature-conservancy-in-the-northwest-indianachicagoland-region-from-science-to-preservation |archive-url=https://web.archive.org/web/20160101021140/http://www.southshorejournal.org/index.php/issues/volume-3-2009/83-journals/vol-3-2009/75-the-historical-roots-of-the-nature-conservancy-in-the-northwest-indianachicagoland-region-from-science-to-preservation |archive-date=1 January 2016 |access-date=22 November 2015}}</ref>
*Herring Cove,<ref>{{Cite web |title=Herring Cove Beach – Cape Cod National Seashore (U.S. National Park Service) |url=https://www.nps.gov/caco/planyourvisit/herring-cove-beach.htm |access-date=29 July 2018 |website=www.nps.gov}}</ref> Race Point<ref>{{Cite web |title=Race Point Beach – Cape Cod National Seashore (U.S. National Park Service) |url=https://www.nps.gov/caco/planyourvisit/race-point-beach.htm |access-date=29 July 2018 |website=www.nps.gov}}</ref> and The Province Lands bicycle path<ref>{{Cite web |title=Province Lands Bike Trail – Cape Cod National Seashore (U.S. National Park Service) |url=https://www.nps.gov/caco/planyourvisit/province-lands-bike-trail.htm |access-date=29 July 2018 |website=www.nps.gov}}</ref> in [[Provincetown, Massachusetts]] as part of the [[National Park Service|US National Park Service]] of the [[Cape Cod National Seashore]].
* Michigan:
**[[Sleeping Bear Dunes National Lakeshore]], [[Michigan]], on the east shore of [[Lake Michigan]].
**[[Warren Dunes State Park]], [[Michigan]], on the east shore of [[Lake Michigan]].
**[[Grand Sable Dunes]], in the [[Pictured Rocks National Lakeshore]], [[Michigan]].
**[[Hoffmaster State Park]] – [[Muskegon]], [[Michigan]]
**[[Silver Lake State Park (Michigan)|Silver Lake State Park]] — a sand dunes that allows off-road vehicle use located near [[Mears, Michigan]].
*Grey Cloud Dunes- [[Minnesota]]<ref>{{Cite web |last1=Blvd |first1=Mailing Address: 111 E. Kellogg |last2=Paul |first2=Suite 105 Saint |last3=Us |first3=MN 55101 Phone: 651-293-0200 This is the general phone line at the Mississippi River Visitor Center Contact |title=Grey Cloud Dunes Scientific and Natural Area - Mississippi National River & Recreation Area (U.S. National Park Service) |url=https://www.nps.gov/miss/planyourvisit/greydune.htm |access-date=2023-04-21 |website=www.nps.gov |language=en}}</ref>
*[[White Sands National Park]], [[New Mexico]].
*[[Jockey's Ridge State Park]] – on the [[Outer Banks]], [[North Carolina]].
* [[Beaver Dunes State Park]] near [[Beaver, Oklahoma]].
* [[Oregon Dunes National Recreation Area]] near [[Florence, Oregon]], on the Pacific Coast.
*[[Monahans Sandhills State Park]] near [[Odessa, Texas]].
*[[Little Sahara Recreation Area]], [[Utah]].
*The Killpecker sand dunes of the [[Red Desert (Wyoming)|Red Desert]] in southwestern [[Wyoming]].

==== Mexico ====

*[[Samalayuca Dune Fields|Samalayuca Dunes]], in the state of [[Chihuahua (state)|Chihuahua]], [[Mexico]]

===South America===
[[File:Lencois Maranhenses 7.jpg|thumb|White sand dunes in the [[Lençóis Maranhenses National Park]], Maranhão, Brazil]]
[[File:Dunas do Araça Ilha Comprida.JPG|thumb|Araça Dunes, in [[Ilha Comprida Environmental Protection Area]], [[São Paulo (state)|São Paulo]], Brazil]]
[[File:Joaquina (3493428239).jpg|thumb|Joaquina Beach, [[Santa Catarina (state)|Santa Catarina]]]]
* Argentina:
** [[Duna Federico Kirbus]] in [[Catamarca Province]], [[Argentina]]
** [[Villa Gesell]] in [[Buenos Aires Province]], Argentina
* Brazil:
** [[Lençóis Maranhenses National Park]] in the state of [[Maranhão]], [[Brazil]]
** [[Ilha Comprida Environmental Protection Area]] in the state of [[São Paulo (state)|São Paulo]], Brazil
** Joaquina Beach Dunes in [[Florianópolis]], in the state of [[Santa Catarina (state)|Santa Catarina]], Brazil
** [[Jericoacoara National Park]], in the state of [[Ceará]], Brazil
** [[Genipabu]] in [[Natal, Rio Grande do Norte|Natal]], Brazil
* Chile:
** Cerro Medanoso in [[Atacama Region]], [[Chile]]
** [[Colún Beach]], [[Valdivian Coastal Reserve]] in Chile
** {{ill|Dunas de Concón|es|vertical-align=sup}}, [[Chile]]
** {{ill|Cerro Dragón (Chile)|es|vertical-align=sup}}, urban dune in Iquique, Chile
* Peru:
** Cerro Blanco in [[Nazca Province]], [[Peru]]
** [[Huacachina]] in [[Ica Region]], [[Peru]]
* [[Medanos de Coro National Park]] near the town of [[Coro (city)|Coro]], in [[Falcón State]], [[Venezuela]]

[[File:Camels in the Desert (8332117351).jpg|thumb|Coastal dunes at Stockton Beach in the [[City of Newcastle]]]]

===Oceania===
* [[Simpson Desert]] sand dunes in the [[Northern Territory]], [[Queensland]] and [[South Australia]], [[Australia]]
* [[Coorong National Park]] in South Australia, Australia
* [[Lincoln National Park]] in South Australia, Australia
* [[Coffin Bay National Park]] in South Australia, Australia
* [[Fraser Island]] in Queensland, Australia
* [[Cronulla sand dunes]] in [[New South Wales]], Australia
* [[Stockton Beach]] in New South Wales, Australia
* [[Lancelin, Western Australia|Lancelin]] sand dunes in Western Australia, Australia
* Te Paki sand dunes near [[Cape Reinga]], New Zealand

{{clear}}

===World's highest dunes===
{| class="wikitable sortable"
|+ Note: This table is partially based on estimates and incomplete information.
|- style=background:silver; color:black
! width="200"|Dune !! width="130"|Height from base metres (feet) !! width="160"|Height from sea level metres (feet) !! width="460"|Location !! width="180"|Notes
|-
![[Duna Federico Kirbus]]
|≈{{cvt|1,230|m}} || ≈{{cvt|2,845|m}} || Bolsón de Fiambalá, [[Fiambalá]], [[Catamarca Province]], [[Argentina]] || Highest in the world<ref>{{cite web|url=http://sand-boarding.com/tallest-sand-dunes-in-the-world/|title=Tallest Sand Dunes in the World|website=Surf the Sand|date=9 December 2020|access-date=9 Dec 2020}}</ref>
|-
!Cerro Blanco
|≈{{cvt|1,176|m}} || ≈{{cvt|2,080|m}} || [[Nazca Province]], [[Ica Region]], [[Peru]] {{coord|-14.868|-74.838|type:mountain_globe:earth_region:PE-ICA_scale:150000|name=Cerro Blanco Dune}}|| Highest in Peru, second highest in the world
|-
!Badain Jaran Dunes
| ≈{{cvt|500|m}} || ≈{{cvt|2,020|m}} || [[Badain Jaran Desert]], Alashan Plain, Inner Mongolia, [[Gobi Desert]], China || World's tallest stationary dunes and highest in Asia<ref>[https://www.newscientist.com/article.ns?id=dn6712 "Mystery of world's tallest sand dunes solved"—24 November 2004—''New Scientist''<!-- Bot generated title -->] {{webarchive|url=https://web.archive.org/web/20081026210614/http://www.newscientist.com/article.ns?id=dn6712 |date=26 October 2008 }}</ref>
|-
!Rig-e Yalan Dune
| ≈{{cvt|470|m}} || ≈{{cvt|950|m}} || [[Lut Desert]], Kerman, Iran|| Hottest place on Earth (Gandom Beryan)
|-
|-
!Average Highest Area Dunes
| {{cvt|430|m}}? || ≈{{cvt|1,980|m}}? || Isaouane-n-Tifernine Sand Sea, Algerian Sahara || Highest in Africa
|-
!Big Daddy/Dune 7<br />(Big Mama?)<ref>[http://www.met.gov.na/dpwm/parkprof/Sossusvlei/2nd%20Fact%20sheet%20Sossusvlei.pdf Big Mama highest dune] {{webarchive|url=https://web.archive.org/web/20090902115328/http://www.met.gov.na/dpwm/parkprof/Sossusvlei/2nd%20Fact%20sheet%20Sossusvlei.pdf |date=2 September 2009 }}</ref>
| {{cvt|383|m}} || ≈{{cvt|570|m}} || 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
| ≈{{cvt|280|m}} || ≈{{cvt|280|m}} || [[Moreton Island]], [[Brisbane]], Australia || Highest in Australia
|-
!Star Dune
| >{{cvt|230|m}} || ≈{{cvt|2,730|m}} || [[Great Sand Dunes National Park and Preserve]], Colorado, USA || Highest in North America
|-
![[Dune of Pyla|Dune of Pilat]]
| ≈{{cvt|105|m}} || ≈{{cvt|130|m}} || Bay of [[Arcachon]], Aquitaine, France || Highest in Europe
|-
!Ming-Sha Dunes
| ? || {{cvt|1,725|m}} || [[Dunhuang]] Oasis, Taklamakan Desert, Gansu, China ||
|-
!Medanoso Dune
| ≈{{cvt|550|m}} || ≈{{cvt|1,660|m}} || [[Atacama Desert]], Chile || Highest in Chile
|}

===Sand dune systems===
:[[File:Sleeping Bear Dunes Wilderness (886c714f-8cf1-4a2a-ad85-c05e8dce5642).jpg|thumb|[[Sleeping Bear Dunes National Lakeshore|Sleeping Bear Dunes]] in [[Michigan]]]](coastal dunes featuring succession)
* [[Athabasca Sand Dunes Provincial Park]], [[Alberta]] and [[Saskatchewan]]
* [[Ashdod Sand Dune]], [[Israel]]
* [[Bamburgh Dunes]], [[Northumberland]], England
* [[Bradley Beach, New Jersey|Bradley Beach]], [[New Jersey]]
* [[Circeo National Park]], a Mediterranean dune area on the southwest coast of the [[Lazio]] region of [[Italy]]
* [[Cronulla sand dunes]], [[New South Wales|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, County Down|Newcastle]], [[County Down|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]], [[Wales]]

===Extraterrestrial dunes===
[[File:Gusev Crater, Mars.jpg|thumb|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 (moon)|Titan]].

Titan's dunes include large expanses with modal lengths of about 20–30&nbsp;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.<ref>[http://www.planetary.org/blog/article/00000733/ Peeking Through the Haze: Titan's Surface, part II—The Planetary Society Blog | The Planetary Society<!-- Bot generated title -->] {{webarchive|url=https://web.archive.org/web/20070428143333/http://www.planetary.org/blog/article/00000733/ |date=28 April 2007 }}</ref>

Dunes are a popular theme in science fiction, featuring in depictions of dry [[Desert planet]]s<ref name="Touponce 7">{{Cite book|last=Touponce |first=William F. |year=1988 |title=Frank Herbert|chapter=Intellectual Background |location=[[Boston]]|publisher=Twayne Publishers imprint, G. K. Hall & Co|page=119 |isbn=978-0-8057-7514-3}}</ref> appearing as early as the 1956 film ''[[Forbidden Planet]]'' and [[Frank Herbert]]'s 1965 novel ''[[Dune (novel)|Dune]]''.<ref>{{cite web|url=http://www.culturevulture.net/Movies4/ForbiddenPlanet.htm |first=Les|last=Wright|title=''Forbidden Planet'' (1956)|publisher=Culturevulture.net ([[Internet Archive]]) |access-date=May 7, 2006 |archive-url= https://web.archive.org/web/20060507194241/http://www.culturevulture.net/Movies4/ForbiddenPlanet.htm |archive-date=May 7, 2006}}</ref><ref name="Hladik">{{cite web|url=http://www.scifi.com/sfw/issue42/classic.html |title=Classic Sci-Fi Reviews: ''Dune''|first=Tamara I.|last=Hladik|publisher=SciFi.com|access-date=April 20, 2008 |archive-url =https://web.archive.org/web/20080420150907/http://www.scifi.com/sfw/issue42/classic.html |archive-date = April 20, 2008}}</ref><ref name="Dune Endures">{{Cite magazine |first=Jon |last=Michaud |url=http://www.newyorker.com/online/blogs/books/2013/07/dune-endures.html |title=''Dune'' Endures |magazine=The New Yorker |date=July 12, 2013 |access-date=November 27, 2013}}</ref> The environment of the desert planet [[Arrakis]] (also known as Dune) in the [[Dune (franchise)|''Dune'' franchise]]<ref>{{cite book |last1=Lynch |first1=Tom |last2=Glotfelty |first2=Cheryll |last3=Armbruster |first3=Karla |title=The Bioregional Imagination: Literature, Ecology, and Place |date=2012 |publisher=[[University of Georgia Press]] |isbn=978-0-8203-4367-9 |page=230 |url=https://books.google.com/books?id=flt4Uea3oOcC&pg=PA230}}</ref> ''Dune'' in turn inspired the ''[[Star Wars]]'' franchise,<ref>{{cite web |work=D. A. Houdek |title=Star Wars is Dune |url=http://www.dahoudek.com/pages/starwarsdune.htm |access-date=October 1, 2006 |archive-date=8 October 2006 |archive-url=https://web.archive.org/web/20061008120525/http://www.dahoudek.com/pages/starwarsdune.htm }}</ref> which includes prominent theme of dunes on fictional planets such as [[Tatooine]], [[Geonosis]], and [[Jakku]].

==See also==
{{div col|colwidth=20em|rules=yes}}
* [[Antidune]]
* [[Devil's stovepipe]]
* [[Ice dune]]
* [[List of landforms]]
* [[Masseira]]
* [[Médanos (geology)|Médanos]]
* [[Sandhill]]
* [[Sand wave]]
* [[Singing sand]]
* [[Strand plain]]
{{Div col end}}

==Notes==
{{Reflist}}

==References==
* {{cite book|last=Bagnold|first=Ralph|author-link=Ralph Bagnold|title=The Physics of Blown Sand and Desert Dunes|year=2012|orig-date=1941|publisher=Courier Dover Publications|isbn=978-0-486-14119-0}}

== Further reading ==
* {{Cite book |author1=Ralph Lorenz |author2=James Zimbelman |title=Dune Worlds: How Wind-blown Sand Shapes Planetary Landscapes |publisher=Springer |year=2014 |isbn=978-3-540-89724-8}}
* {{cite book|editor= Anthony J. Parsons, A. D. Abrahams|title=Geomorphology of Desert Environments|year=2009|publisher=Springer|isbn=978-1-4020-5718-2}}
* {{cite book|last1=Pye|first1=Kenneth|last2=Tsoar|first2=Haim|title=Aeolian Sand and Sand Dunes|year=2009|publisher=Springer|isbn=978-3-540-85909-3}}
* {{Cite web | url=http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=17168 | title=Nouakchott, Mauritania | publisher=[[NASA Earth Observatory]] | access-date=28 April 2006 | archive-url=https://web.archive.org/web/20060930235428/http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=17168 | archive-date=30 September 2006}}
*{{cite journal |doi=10.1002/ldr.864 |title=Sand dune fixation: A solar-powered Sahara seawater pipeline macroproject |journal=Land Degradation & Development |volume=19 |issue=6 |pages=676–691 |year=2008 |last1=Badescu |first1=V. |last2=Cathcart |first2=R. B. |last3=Bolonkin |first3=A. A. |arxiv=0707.3234 |bibcode=2008LDeDe..19..676B |s2cid=128961228 }}
* {{Cite web | url=http://www.agc.army.mil/research/products/desert_guide/lsmsheet/lspara.htm | title=Summary: Dunes, Parabolic | publisher=Desert Processes Working Group; Knowledge Sciences, Inc. | access-date=6 October 2010 | archive-url=https://web.archive.org/web/20101021072044/http://www.agc.army.mil/research/products/desert_guide/lsmsheet/lspara.htm | archive-date=21 October 2010}}
* {{Cite web | url=http://www.csf-desertification.org/index.php/bibliotheque/publications-csfd/les-dossiers-du-csfd-english/doc_details/142-mainguet-monique-a-dumay-frederic-2011-fighting-wind-erosion- | title=Fighting wind erosion. One aspect of the combat against desertification | publisher=Les dossiers thématiques du CSFD | access-date=4 January 2011 | archive-url=https://web.archive.org/web/20110725212257/http://www.csf-desertification.org/index.php/bibliotheque/publications-csfd/les-dossiers-du-csfd-english/doc_details/142-mainguet-monique-a-dumay-frederic-2011-fighting-wind-erosion- | archive-date=25 July 2011}}

==External links==
{{Commons and category|Dune|Dunes}}
*[https://physicalgeography.org/sand-dunes-and-different-types-of-sand-dunes/ Types of Sand Dunes]
*[https://beginnorthadventures.com/loibor-seder-sand-dune-kenya/ Loibor Seder Kenya's Biggest Sand Dune]
*[https://web.archive.org/web/20060819172200/http://www.geography-site.co.uk/pages/physical/coastal/dunes.html Coastal Sand Dunes]
*[https://web.archive.org/web/20060308183125/http://www.tec.army.mil/research/products/desert_guide/lpisheet/lpdunes1.htm Dune pattern identification, U.S. Army]
*{{URL|https://data.mendeley.com/datasets/675gwk5jp7/1|The Bibliography of Aeolian Research}}

{{River morphology}}
{{coastal geography}}
{{Patterns in nature}}
{{sediment transport}}

{{Authority control}}

[[Category:Dunes| ]]
[[Category:Aeolian landforms]]
[[Category:Coastal and oceanic landforms]]
[[Category:Coastal geography]]
[[Category:Sedimentology]]