Volcano - Le Piton de la Fournaise
Geologic Background:
A basaltic shield volcano, Piton de la Fournaise, forms the SE half of Réunion Island, 800 km E of Madagascar. It has been one of the most active oceanic volcanoes, with more than 100 eruptions in the last 300 years and there have been between two and four eruptions annually since 1998.
Much of its more than 530,000 year history overlapped with eruptions of the deeply dissected Piton des Neiges shield volcano to the NW. Three calderas formed at about 250,000, 65,000, and less than 5,000 years ago by progressive eastward slumping of the volcano. Numerous pyroclastic cones dot the floor of the calderas and their outer flanks.
Historical Activity:
Most historical eruptions have originated from the summit and flanks of a 400-m-high lava shield that has grown within the youngest caldera (Enclos Fouqué), which is 8 km wide and breached to below sea level on the eastern side.
More than 150 eruptions, most of which have produced fluid basaltic lava flows, have occurred since the 17th century.
Only six eruptions, in 1708, 1774, 1776, 1800, 1977, and 1986, have originated from fissures on the outer flanks of the caldera. But don't go away, 2006 could offer a little extra...
Click here for a link to the site of the "Observatoire de La Piton de la Fournaise" - in French
