Report on Piton de la Fournaise (France) — 30 August-5 September 2006
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
30 August-5 September 2006
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2006. Report on Piton de la Fournaise (France). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 30 August-5 September 2006. 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)
A small "seismic crisis" at Piton de la Fournaise began at 1000 on 30 August. A summit eruption started from the SSE edge of Dolomieu Crater at 1135 and scientists witnessed the opening of a fissure on the crater floor. A large portion of the crater floor was covered with lava by the afternoon. A second fissure opened just outside of the crater and produced a lava flow on the E flank. On 31 August, seismicity remained high and a new cone had formed in Dolomieu Crater.
Geological Summary. Piton de la Fournaise is a massive basaltic shield volcano on the French island of Réunion in the western Indian Ocean. 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 scarps formed at about 250,000, 65,000, and less than 5,000 years ago by progressive eastward slumping, leaving caldera-sized embayments open to the E and SE. Numerous pyroclastic cones are present on the floor of the scarps and their outer flanks. Most recorded eruptions have originated from the summit and flanks of Dolomieu, a 400-m-high lava shield that has grown within the youngest scarp, which is about 9 km wide and about 13 km from the western wall to the ocean on the E 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 outside the scarps.