Eruption at Piton de la Fournaise volcano, Reunion

A new eruption started at Piton de la Fournaise volcano, Reunion at around 23:30 UTC on December 21, 2021. The alert level was raised to 2-1. Trails in the upper part of the summit were closed for the public.

The seismic crisis started at around 21:15 UTC, suggesting magma is rising toward the surface. Just a few minutes before the eruption started, instruments at the volcano recorded rapid ground deformation.

By 23:30 UTC (03:30 LT on December 22), three eruptive fissures opened on the volcano’s southern flank, followed by fourth several hours later.¹

At 03:30 UTC on December 22, the most important activity was on the lowest fissure at an altitude of 2 km (1.2 miles).

 

Début d’éruption au #PitondelaFournaise ce 22/12/2021. Suite à la crise sismique débutée à 01h15 heure locale, le trémor volcanique est enregistré depuis environ 03h30 environ heure locale. L’éruption est localisée sur le flanc sud dans l’Enclos. https://t.co/iYIfNPMxBD pic.twitter.com/dpr8ORWeYm

— Observatoire Volcanologique Piton de la Fournaise (@ObsFournaise) December 22, 2021

Première image de l’éruption débutée aujourd’hui 22/12/2021 aux alentours de 3h30 heure locale au #PitondelaFournaise sur les webcams de l’OVPF-IPGP.
Les webcams en direct sur ce lien: https://t.co/0f6rwWNKy1 pic.twitter.com/eAgKI5g0XX

— Observatoire Volcanologique Piton de la Fournaise (@ObsFournaise) December 22, 2021

 Début d’éruption au #PitondelaFournaise ce jour, 22/12/2021 aux alentours de 3h30. Au moins 3 fissures éruptives se sont ouvertes sur le flanc sud du volcan. ©OVPF-IPGP pic.twitter.com/JXdfBDZW3d

— Observatoire Volcanologique Piton de la Fournaise (@ObsFournaise) December 22, 2021

 L’éruption au #PitondelaFournaise se poursuit. Ce sont au final 4 fissures qui se sont ouvertes sur le flanc sud. A 8h30 l’activité la plus importante se situait sur la fissure la plus basse en altitude à 2000 m. ©️OVPF-IPGP. Communiqué complet ici https://t.co/CDi2nTAAsL pic.twitter.com/9S1OrW1KMR

— Observatoire Volcanologique Piton de la Fournaise (@ObsFournaise) December 22, 2021

 

The last eruption of this volcano took place in April and May 2021.²

Geological summary

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 5 000 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 (1 312 feet) lava shield that has grown within the youngest caldera, which is 8 km (26 247 feet) 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 17^th 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 (IPGP), monitors this very active volcano.³

References:

¹ Communiqué du 22/12/2021 – 11h45 (heure locale) – OVPF

² Effusive eruption continues at Piton de la Fournaise volcano, lava reaches Piton le Bonnet, Reunion – The Watchers

³ Piton de la Fournaise – geological summary – GVP

Featured image credit: OVPF-IFGP