||This article includes a list of references, but its sources remain unclear because it has insufficient inline citations. (February 2008)|
Eldfell, June 2007
|Elevation||200 m (656 ft)|
|
||This article includes a list of references, but its sources remain unclear because it has insufficient inline citations. (February 2008)|
Eldfell, June 2007
|Elevation||200 m (656 ft)|
|Prominence||200 m (656 ft)|
|Location||Heimaey island, Vestmannaeyjar, Iceland|
|Age of rock||Historical|
|Volcanic arc/belt||Southern Volcanic Flank Zone|
|Last eruption||January to June 1973|
Eldfell is a composite volcanic cone just over 200 metres (660 ft) high on the Icelandic island of Heimaey. It formed in a volcanic eruption which began on the eastern side of Heimaey in the Westman Island on 23 January 1973. This came without any sign of warning. The name of Eldfell means Mountain of Fire in Icelandic.
The eruption caused a major crisis for the island and nearly led to its permanent evacuation. Volcanic ash fell over most of the island, destroying around 400 homes, and a lava flow threatened to close off the harbour, the island's main income source via its fishing fleet. An operation was mounted to cool the advancing lava flow by pumping sea water onto it, which was successful in preventing the loss of the harbour.
After the eruption, the islanders used heat from the cooling lava flows to provide hot water and to generate electricity. They also used some of the extensive tephra, fall-out of airborne volcanic material, to extend the runway at the island's small airport, and as landfill, on which 200 new houses were built. 
Iceland is a region of frequent volcanic activity, due to its location astride the Mid-Atlantic Ridge, where the North American and Eurasian Plates are moving apart, and also over the Iceland hotspot, which greatly enhances the volcanic activity. It is estimated that a third of all the basaltic lava erupted in the world in recorded history has been produced by Icelandic eruptions.
The Vestmannaeyjar (Westman Islands) archipelago lies off the south coast of Iceland, and consists of several small islands, all formed by eruptions in the Holocene epoch. Heimaey, the largest island in the group and the only inhabited one, also contains some material from the Pleistocene era. The most prominent feature on Heimaey before 1973 was Helgafell, a 200 meters (650 ft) high volcanic cone formed in an eruption about 5,000 years ago.
The Vestmannaeyjar archipelago was settled in about 874 AD, originally by escaped Irish slaves belonging to Norse settlers on the mainland. These settlers gave the islands their name, Ireland being west of mainland Scandinavia. Although plagued by poor water supplies and piracy during much of its history, Heimaey became the most important centre of the Icelandic fishing industry, having one of the few good harbours on the southern side of the country, and being situated in very rich fishing grounds.
Since the settlement, no eruptions had been known to occur on the islands until 1963, when a new member of the archipelago, Surtsey, was formed by a four-year eruption which began offshore about 20 kilometres (12 mi) south-west of Heimaey. However, offshore eruptions may have taken place in 1637 and 1896. Scientists have speculated that volcanic activity in the archipelago may be increasing due to the southward propagation of the rift zone that crosses Iceland.
The eruption begins
At about 20:00 on 21 January 1973, a series of small tremors began to occur around Heimaey. They were too wea