Report on Piton de la Fournaise (France) — 20 October-26 October 2010
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 20 October-26 October 2010
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2010. Report on Piton de la Fournaise (France). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 20 October-26 October 2010. Smithsonian Institution and US Geological Survey.
Piton de la Fournaise
21.244°S, 55.708°E; summit elev. 2632 m
All times are local (unless otherwise noted)
OVPDLF reported that an eruption from Piton de la Fournaise that began on 14 October from a fissure near the Château Fort crater, about 1.5 km SE of the Dolomieu crater rim, continued during 19-25 October. On 19 October, explosive and degassing activity from vents along the fissure increased, but was still below the intensity noted at the beginning of the eruption. During 20-21 October small lava fountains fed lava flows that traveled as far as 2 km E and SE. Decreased gas emissions were concentrated to the S and W of the fissure. During 22-24 October fountains and gas emissions originated from one vent, and lava traveled ESE. Gas emissions decreased significantly.
Geologic Background. The massive Piton de la Fournaise basaltic shield volcano on the French island of Réunion in the western Indian Ocean is one of the world's most active volcanoes. 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 5000 years ago by progressive eastward slumping of the volcano. Numerous pyroclastic cones dot the floor of the calderas and their outer flanks. Most historical eruptions have originated from the summit and flanks of Dolomieu, a 400-m-high lava shield that has grown within the youngest caldera, 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. The Piton de la Fournaise Volcano Observatory, one of several operated by the Institut de Physique du Globe de Paris, monitors this very active volcano.