A hotspot is a region of high volcanic activity not located at a tectonic plate boundary. It is caused by upwelling of deep mantle plumes. Hotspots are 100 to 200 km across.
Hawaii is the best known example of hotspot volcanism. The mantle plumes are long lived and relatively stable. As an area moves over the plume new volcanoes form producing a chain of volcanoes.
Hotspots are irregularly distributed over half the world's surface and estimates of their total number varies from 42 to 117.
A recent theory suggests that Antipodal hotspots were caused by oceanic large-body impacts.
Volcanic Hotspots of the World
Afar, Amsterdam, Anahim, Ascension, Azores, Balleny, Bermuda, Bouvet, Bowie, Cameroon, Canary, Cape Verde, Caroline, Cobb, Comoros, Crozet, Darfur, Discovery, East Australia, Easter, Eifel, Fernando, Galápagos, Gough, Guadalupe, Hawaii, Heard, Hoggar, Iceland, Jan Mayen, Juan Fernandez, Kerguelen, Lord Howe, Louisville, Macdonald, Madeira, Marion, Marquesas, Meteor hotspot, New England, Pitcairn, Raton, Réunion, St. Helena, St. Paul, Samoa, San Felix, Shona, Society, Socorro, Tasmanid, Tibesti, Trindade, Tristan, Vema, Yellowstone.