Report on Piton de la Fournaise (France) — December 1988
Scientific Event Alert Network Bulletin, vol. 13, no. 12 (December 1988)
Managing Editor: Lindsay McClelland.
Piton de la Fournaise (France) Fissure eruption in N part of caldera
Please cite this report as:
Global Volcanism Program, 1988. Report on Piton de la Fournaise (France) (McClelland, L., ed.). Scientific Event Alert Network Bulletin, 13:12. Smithsonian Institution.
Piton de la Fournaise
21.244°S, 55.708°E; summit elev. 2632 m
All times are local (unless otherwise noted)
The onset of the 14 December eruption, at 1303, followed 40 minutes of 1-Hz tremor. Data from the tilt network had allowed geologists to reach the field 2 hours earlier and provided an excellent forecast of vent location. Geologists heard (and saw through clouds) the opening of a 400-m fissure N of Faujas Crater that ejected 20-50-m fountains of aphyric basalt and built a new cone. A second fissure opened to the SW, but lava production was low. During the following days, a significant number of discrete seismic events accompanied vigorous tremor. Most seismic events were limited to the summit zone, but some were recorded in the N part of the caldera. Eruptive activity stopped suddenly on 29 December at 0150. Since then, seismic activity has progressively resumed.
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: H. Delorme, P. Nerbusson, D. Vandamme, J. Delmond, and P. Taochi, OVPDLF; P. Bachelery, Univ de la Réunion; J. Dubois, J-L. Cheminée, A. Hirn, J. LePine; P. Blum, and J. Zlotnicki, IPGP.