Report on Piton de la Fournaise (France) — 14 March-20 March 2001
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
14 March-20 March 2001
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2001. Report on Piton de la Fournaise (France). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 14 March-20 March 2001. 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)
The OVPDLF reported that instrumental measurements suggest that Piton de la Fournaise may be entering a phase of heightened activity. Periods of increased seismic activity were recorded in late January with up to 13 earthquakes per day, in late February to early March with up to 126 earthquakes per day, and from 10 March until at least 15 March with up to 20 earthquakes per day. Inflation was detected at the volcano's summit from mid-January to early February, and from the end of February to early March. Since mid-January a continuous opening of fissures was recorded at the N and S bases of the volcano, indicating inflation of the summit area. Similar variations in activity were observed before eruptions on the E and S flanks of the volcano in 1999 and 2000.
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.