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Arenal: recent activity 10 June 2008

Posted by admin in activity reports, Arenal, Costa Rica, volcanoes.
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Arenal volcano in Costa Rica is a youthful and vigorous stratovolcano, almost continually active since its current phase of activity began with a violent and deadly eruption in 1968. To quote the Global Volcanism Program’s Arenal summary, ‘Continuous explosive activity accompanied by slow lava effusion and the occasional emission of pyroclastic flows has occurred since then from vents at the summit and on the upper western flank’.

The most recent instance of this type of activity was reported by the Observatorio Vulcanológico y Sismológico de Costa Rica (the inevitable acronym is OVISCORI) on 6 June 2008. A pyroclastic flow was generated on the south-western flank of Arenal when an accumulation of blocky, andesitic lava at the summit, the remnant of a March 2007 lava flow, collapsed. The flow descended some 800m, with pulverized material rising from it to produce a tall plume of gases and dust that provoked alarm in tourists and park officials The park was quickly evacuated and closed, no-one was hurt, and there was no further activity.

Bulletins on this activity (PDF) in both Spanish and English can be accessed from OVISCORI’s ‘Informes de Prensa’ page.

Arenal provides a fascinating case study in the ways human societies interact with and live alongside active volcanoes: its spectacular but largely safe activity attracts thousands of visitors, and it is at the heart of a national park that is one of Costa Rica’s main tourist attractions, while the lake at the foot of the volcano, Lago Arenal, has become the site of a large hydroelectric scheme that provides around 40% of the country’s electricity. Arenal.net, a travel-oriented site, offers a great deal of information about the volcano including maps, photographs and links.

UPDATE: There’s a report on what’s happened at Arenal, with some nice clear discussion of the science behind this kind of activity, over at Erik’s Eruptions blog.

Information
Global Volcanism Program: Arenal – volcano information for Arenal (1405-033)
Observatorio Vulcanológico y Sismológico de Costa Rica – main page for Ovsicori

The Volcanism Blog