Report on Piton de la Fournaise (France) — 5 October-11 October 2005
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
5 October-11 October 2005
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2005. Report on Piton de la Fournaise (France). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 5 October-11 October 2005. 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 started at Piton de la Fournaise on 4 October at 1426 after 4 months of almost continuous inflation and increased seismicity at the volcano. The eruption was preceded by a 56-minute-long seismic crisis and strong summit inflation. The low-intensity eruption occurred at Dolomieu crater and produced pahoehoe lava flows that covered a small area of the western part of the 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.