Dune

Dune fields in the Australian desert.
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.[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]

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]

  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. Archived (PDF) from the original on 20 September 2017. Retrieved 15 January 2021.
  5. ^ "The dune system". Restoconlife. Parco Nazionale Arcipelago Toscano. 2010. Archived from the original on 25 March 2023. 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. Archived (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.