Report on Piton de la Fournaise (France) — July 1998
Bulletin of the Global Volcanism Network, vol. 23, no. 7 (July 1998)
Managing Editor: Richard Wunderman.
Piton de la Fournaise (France) New lava flow traverses 12 km across the E flank
Please cite this report as:
Global Volcanism Program, 1998. Report on Piton de la Fournaise (France) (Wunderman, R., ed.). Bulletin of the Global Volcanism Network, 23:7. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199807-233020.
Piton de la Fournaise
21.244°S, 55.708°E; summit elev. 2632 m
All times are local (unless otherwise noted)
The eruption that began in March (BGVN 23:03) continued in August. A new lava flow crossed the Plaine des Osmondes and went down the E flank towards the sea. As of 31 July its front had reached 250 m from the new national road. By 3 August it had slowly progressed to within 100 m of the road. On 4 August the front moved forward suddenly; within a few hours it had crossed the old national road and stopped ~3 m in front of the new national road. No new movement of the lava flow was observed during the next week. The flow had reached a total length of 12 km. Some small but new lava flows were visible in the upper part of the Grand Brûlé. Tremor episodes had diminished in the past few months, but beginning on 6 August there was a sudden tenfold increase over levels of the preceding weeks. The increased activity persisted the following week.
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.
Information Contacts: Thomas Staudacher, Observatoire Volcanologique du Piton de la Fournaise (OVPF), 14 RN3, le 27Km, 97418 La Plaine des Cafres, La Réunion, France.