Report on Piton de la Fournaise (France) — 5 February-11 February 2020
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 5 February-11 February 2020
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2020. Report on Piton de la Fournaise (France). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 5 February-11 February 2020. 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 a seismic crisis at Piton de la Fournaise began at 1027 on 10 February, accompanied by rapid deformation. Volcanic tremor began just 23 minutes later, at 1050, heralding the start of a new eruption. During an overflight conducted during 1300-1330 in partly cloudy weather, observers noted that several fissures had opened on the E flank of Dolomieu Crater, between the crater rim and 2,000 m elevation. The fissures all were at least 1 km long and produced lava fountains that were no higher than 10 m. Lava flows had traveled E to 1,700 m elevation by 1315. In the evening mapping of the lava flows based on satellite data revealed a larger flow field that what was visually observed during the overflight hours before. Lava flows spanned from the E to the S, with the farthest flow traveling E to 1,400 m elevation. The data showed that the fissures at the highest elevation had opened in the same area as those from the 18 February and 11 June 2019 eruptions.
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.