Report on Piton de la Fournaise (France) — 26 August-1 September 2015
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 26 August-1 September 2015
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2015. Report on Piton de la Fournaise (France) (Sennert, S, ed.). Weekly Volcanic Activity Report, 26 August-1 September 2015. 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)
OVPDLF reported that the eruption at Piton de la Fournaise fluctuated during 26-27 August, causing variations in the height of the lava fountains and emissions. One vent remained active, and lava flows from that vent traveled at least as far as 3.5 km. At daybreak on 28 August a small plume rose 400 m and drifted S; inclement weather prevented views during most of the day. During an overflight the next day, scientists observed two growing cinder cones housing lava lakes and lava fountains. An 'a'a lava flow was active, and a large gas plume rose 3 km.
Geological Summary. Piton de la Fournaise is a massive basaltic shield volcano on the French island of Réunion in the western Indian Ocean. 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 scarps formed at about 250,000, 65,000, and less than 5,000 years ago by progressive eastward slumping, leaving caldera-sized embayments open to the E and SE. Numerous pyroclastic cones are present on the floor of the scarps and their outer flanks. Most recorded eruptions have originated from the summit and flanks of Dolomieu, a 400-m-high lava shield that has grown within the youngest scarp, which is about 9 km wide and about 13 km from the western wall to the ocean on the E 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 outside the scarps.