Report on Piton de la Fournaise (France) — 27 February-5 March 2019
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 27 February-5 March 2019
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2019. Report on Piton de la Fournaise (France). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 27 February-5 March 2019. 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)
OVPF reported that the fissure that opened 19 February at a site located at 1,800 m elevation at the foot of Piton Madoré, E of Piton de la Fournaise’s Dolomieu Crater, continued during 27 February-5 March. RSAM measurements showed fluctuating intensities though an overall upwards trend. Based on satellite images, the main flow front progressed slowly during 22-28 February, advancing only 300 m to 1,200 m elevation. A new lava flow emerged from an area near the cone and traveled NE; the more southern branches did not advance during 28 February-1 March. Scientists conducted fieldwork on 5 March and noted that the cone had grown to 100 m wide at the base, 25 m tall, and had a vent opening 50 m wide. High-temperature gas emissions rose from the vent, and Strombolian activity ejected material. White steam rose from the base of the cone, likely from the presence of lava tubes. The northernmost lava flow remained active.
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.