Report on Piton de la Fournaise (France) — 12 February-18 February 2020
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 12 February-18 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, 12 February-18 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 the longest-travelling lava flow that began to effuse on 10 February from fissures on the E flank of Piton de la Fournaise’s Dolomieu Crater was no longer advancing by 13 February. The end of the longest active flow was located below Marco Crater around 1,900 m elevation, based on field an aerial observations. A cone was building over three vents and had grown to 30 m high; lava fountains from the three vents rose 10-15 m above the rim of the cone. Tremor levels rapidly decreased around 1400 on 15 February, though inclement weather conditions prevented visual confirmation of changes to the surficial activity. Observers noted no activity while aboard an overflight during 0730-0800 on 16 February, though tremor continued to be recorded. By 1412 tremor ceased, signifying the end of lava effusion.
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.