Portal:Iceland/Selected article/11

The Iceland hotspot is a hotspot which is partly responsible for the high volcanic activity which has formed the island of Iceland. Iceland is one of the most active volcanic regions in the world, with eruptions occurring on average roughly every five years. About a third of the basaltic lavas erupted in recorded history have been produced by Icelandic eruptions. Notable eruptions have included that of Eldgjá in 934 (the world's largest basaltic eruption ever witnessed), Laki in 1783 (the world's second largest), and several eruptions beneath ice caps, which have generated devastating glacial bursts, most recently in 1996.

Iceland's location astride the Mid-Atlantic Ridge, where the Eurasian and North American Plates are moving apart, is partly responsible for this intense volcanic activity, but an additional cause is necessary to explain why Iceland is a substantial island while the rest of the ridge mostly consists of seamounts, with peaks below sea level. It is believed that a mantle plume must lie beneath the island, enhancing the volcanism already caused by plate separation. As well as driving volcanism in the centre of the island, the plume is also believed to feed magma to the Reykjanes ridge, another region of enhanced volcanism to the southwest of Iceland's main volcanic zone.