Piton de la Fournaise (France) – Report for 6 March-12 March 2019

During an overflight between 0700 and 0800 on 6 March tourists observed a new active fissure on the NW flank of Piton de la Fournaise?s Piton Madoré, 150 m upstream of the main vent. The fissure likely opened the day before during 0900 and 1900. The tourist report noted that a small cone had formed, and a lava flow was traveling N. In the morning of 7 March at least six new vents were visible, although weather conditions prevented OVPF volcanologists from confirming if they were along a new fissure. During fieldwork on 8 March volcanologists inspected the 5 March fissure and observed a small cone ejecting material up to 10 m above the rim. Lava from the W side flowed a few tens of meters, and a flow from the N side progressed E. The new vents that opened on 7 March were confirmed to be along an E-W trending fissure. The vents were active, each producing 50-m-high lava fountains. The report also noted that samples from the 5 March and 7 March vents had different compositions, though no other details were noted. Lava flows traveled to around 1,000 m elevation.

Satellite images showed sulfur dioxide plumes drifting 450-550 km E on 8 March. Lava flows rapidly progressed during 8-9 March; the lava emission rate was variable, ranging up to 25 cubic meters per second (based on satellite data), although since the new fissures opened the highest values (over 50 cubic meters per second) measured the past few days were approximately 10 times higher than the average values recorded during the 2017-2018 eruptions. By 0800 on 9 March the flow front was at an estimated elevation of 650-700 m. After a phase of intense surficial activity during 9-10 March, with lava fountains rising as high as 100 m, lava-flow emissions ceased around 0628 on 10 March and seismicity significantly decreased.

Source: Observatoire Volcanologique du Piton de la Fournaise (OVPF)