Satellite photos of peninsulas, clockwise from the top left: The Fennoscandian Peninsula, the Floridian Peninsula, the Horn of Africa, and the Arabian Peninsula.

A peninsula (from Latin paeninsula; from paene 'almost', and insula 'island')[1][2] is a landform that extends from a mainland and is surrounded by water on most, but not all of its borders.[3][4][5] A peninsula is also sometimes defined as a piece of land bordered by water on three of its sides.[3][6] Peninsulas exist on all continents.[7][2] The size of a peninsula can range from tiny to very large.[7] The largest peninsula in the world is the Arabian Peninsula.[8][9] Peninsulas form due to a variety of causes.


Peninsula derives from Latin paeninsula, which is translated as 'peninsula'. Paeninsula itself was derived from paene 'almost', and insula 'island', or together, 'almost an island'.[3] The word entered English in the 16th century.[3]


A peninsula is usually defined as a piece of land surrounded on most, but not all sides, by water,[5] but is sometimes instead defined as a piece of land bordered by water on three of its sides.[6]

A peninsula may be bordered by more than one body of water, and the body of water does not have to be an ocean or a sea.[10] A piece of land on a very tight river bend or one between two rivers is sometimes said to form a peninsula, for example in the New Barbadoes Neck in New Jersey, United States.[5] A peninsula may be connected to the mainland via an isthmus, for example, in the isthmus of Corinth which connects to the Peloponnese peninsula.[11]

Formation and types

Peninsulas can be formed from continental drift, glacial erosion, glacial meltwater, glacial deposition, marine sediment, marine transgressions, volcanoes, divergent boundaries or river sedimentation.[12] More than one factor may play into the formation of a peninsula. For example, in the case of Florida, continental drift, marine sediment, and marine transgressions were all contributing factors to its shape.[13]


In the case of formation from glaciers (e.g., the Antarctic Peninsula or Cape Cod), peninsulas can be created due to glacial erosion, meltwater or deposition.[14] If erosion formed the peninsula, softer and harder rocks were present, and since the glacier only erodes softer rock, it formed a basin.[14] This may create peninsulas, and occurred for example in the Keweenaw Peninsula.[14]

In the case of formation from meltwater, melting glaciers deposit sediment and form moraines, which act as dams for the meltwater.[14] This may create bodies of water that surround the land, forming peninsulas.[14]

If deposition formed the peninsula, the peninsula was composed of sedimentary rock, which was created from a large deposit of glacial drift.[15][16] The hill of drift becomes a peninsula if the hill formed near water but was still connected to the mainland, for example during the formation of Cape Cod about 23,000 years ago.[17][18]


In the case of formation from volcanoes, when a volcano erupts magma near water, it may form a peninsula (e.g., the Alaskan Peninsula).[15] Peninsulas formed from volcanoes are especially common when the volcano erupts near shallow water.[19] Marine sediment may form peninsulas by the creation of limestone.[20] A rift peninsula may form as a result of a divergent boundary in plate tectonics (e.g. the Arabian Peninsula),[21][22] while a convergent boundary may also form peninsulas (e.g. Gibraltar or the Indian subcontinent).[23] Peninsulas can also form due to sedimentation in rivers. When a river carrying sediment flows into an ocean, the sediment is deposited, forming a delta peninsula.[24]

Marine transgressions (changes in sea level) may form peninsulas, but also may affect existing peninsulas. For example, the water level may change, which causes a peninsula to become an island during high water levels.[25] Similarly, wet weather causing higher water levels make peninsulas appear smaller, while dry weather make them appear larger.[26] Sea level rise from global warming will permanently reduce the size of some peninsulas over time.[27]


Peninsulas are noted for their use as shelter for humans and Neanderthals.[28] The landform is advantageous because it gives hunting access to both land and sea animals.[28] They can also serve as markers of nation's borders.[29]

List of peninsulas

Main article: List of peninsulas

See also: Category:Lists of peninsulas

See also


  1. ^ "peninsula". The American Heritage Dictionary of the English Language (5th ed.). HarperCollins. Retrieved 2016-05-01.
  2. ^ a b Nadeau 2006, p. 5.
  3. ^ a b c d HMH 2004, p. 216.
  4. ^ "Definition of peninsula". Cambridge Dictionaries Online. Cambridge University Press. Retrieved 1 May 2016.
  5. ^ a b c Kersey, Paul (23 July 2021). "What is a Peninsula?". Infoplease. Retrieved 2022-04-30.
  6. ^ a b "list of peninsulas". Britannica. Retrieved 2022-04-30.
  7. ^ a b Society, National Geographic (2011-01-21). "peninsula". National Geographic Society. Retrieved 2022-04-30.
  8. ^ Mis 2009, p. 20.
  9. ^ Niz 2006, p. 19.
  10. ^ Heos 2010, p. 15.
  11. ^ Heos 2010, p. 9.
  12. ^ Mis 2009, p. 6.
  13. ^ Heos 2010, p. 8.
  14. ^ a b c d e Heos 2010, p. 31.
  15. ^ a b Nadeau 2006, p. 6.
  16. ^ Heos 2010, p. 32–33.
  17. ^ Nadeau 2006, p. 9.
  18. ^ Wyckoff 1999, p. 328.
  19. ^ Heos 2010, p. 44.
  20. ^ Heos 2010, p. 21–23.
  21. ^ Nadeau 2006, p. 10.
  22. ^ Heos 2010, pp. 43–44.
  23. ^ Heos 2010, p. 40.
  24. ^ Nadeau 2006, p. 13.
  25. ^ Niz 2006, p. 7.
  26. ^ Niz 2006, p. 13.
  27. ^ Nadeau 2006, p. 21.
  28. ^ a b Heos 2010, p. 45.
  29. ^ Heos 2010, p. 48.