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Earth of fire

Actualité volcanique, Articles de fond sur étude de volcan, tectonique, récits et photos de voyage

Publié le par Bernard Duyck
Publié dans : #volcanic activity, #Sismologia, #Tectonics

According to visual feedback from the OVPF-IPGP webcams, and thanks to short gaps in the cloud mass very present on the relief of Piton de la Fournaise, at least four eruptive cracks could be observed. These cracks are located on the southern flank at the base of the terminal cone, to the southeast of the Piton Kala Pélé and to the southwest of the Château Fort crater. The lowest point of emission is around 2000 m above sea level. At 8:30 am on December 22, all four cracks were still active but the most activity was on the lower crack in altitude.

On the evening of December 22, activity focused on only one of the eruptive fissures, the one further downstream, where a cone began to form under the activity of a lava fountain of about 60 m. height.

Piton de La Fournaise - webcam Piton de Bert 22.12.2021 / 13h55 TU - OVPF

Piton de La Fournaise - webcam Piton de Bert 22.12.2021 / 13h55 TU - OVPF

Piton de La Fournaise - webcam Piton de Bert 22.12.2021 / 15:06 UT - OVPF

Piton de La Fournaise - webcam Piton de Bert 22.12.2021 / 15:06 UT - OVPF

Piton de La Fournaise - only the downstream fountain is active on the evening of December 22, with the start of the formation of a cone - OVPF

Piton de La Fournaise - only the downstream fountain is active on the evening of December 22, with the start of the formation of a cone - OVPF

Piton de La Fournaise - trémor at 23.12.2021 / 07h - Doc .OVPF

Piton de La Fournaise - trémor at 23.12.2021 / 07h - Doc .OVPF

Over the last 24 hours:

- The surface deformations do not show any particular displacement.

- Thanks to a milder weather forecast, estimates of lava flow could be established by satellite method with the HOTVOLC platform (OPGC - Clermont Auvergne university), with an average of 4-7 m3 / sec and peaks at 22 m3 / sec.

Since last night, activity has only focused on one of the eruptive cracks, the one further downstream (around 2030 m altitude), where a cone began to form.

 

A field reconnaissance was made on the morning of December 23 thanks to the assistance of the Air Section of the Gendarmerie and the PGHM. This mission made it possible to precisely locate the vent which is still active and the flow front around 9:30 am (local time):

- the lava flow, in graton, had traveled 2.2 km from its point of emission (and was located at approximately 2000 m altitude)

- the flow front was located 550 m from the southern rampart, 3.2 km from the top of the major slopes, 8.1 km from the road and 9 km from the ocean.

This mission also made it possible to recover samples of lava (slag projected by lava fountains and lava flows) which will be very useful, once analyzed, to better understand the path taken by the in-depth magma and the dynamism of the rash. At 9:30 a.m. local time, the lava fountain regime was still very active but with heights only intermittently exceeding the height of the cone, estimated at 10 m.

 

Alert level: Alert 2-1 (eruption in the enclosure)

 

Source: OVPF

Piton de La Fournaise - 12.23.2021 / 9:30 am - location of the emission center and the casting front - Doc. OVPF

Piton de La Fournaise - 12.23.2021 / 9:30 am - location of the emission center and the casting front - Doc. OVPF

Piton de La Fournaise - the eruptive cone on 12/23/2021 / 9 a.m. loc.- photoOVPF

Piton de La Fournaise - the eruptive cone on 12/23/2021 / 9 a.m. loc.- photoOVPF

Lava dome growth continues at Sheveluch, strong fumarole activity, and incandescence of the lava dome and hot avalanches accompany this process. Satellite data from KVERT showed that explosions sent ash on December 23, 2021 up to 5.7-6.0 km altitude, and the ash plume extended 31 km northeast of volcano.

The extrusive eruption of the volcano continues. Ash explosions up to 10-15 km altitude. could arise at any time. Current activity could affect international and low-flying aircraft.

 

The aviation code remains orange.

 

Source: KVERT

Sheveluch - The Growing Dome - photo archives 09.2021 / Andrew Matseevsky

Sheveluch - The Growing Dome - photo archives 09.2021 / Andrew Matseevsky

The summit eruption of the Kīlauea volcano has stopped. Depending on the size and length of recent breaks, the current break should last for several days. All recent lava activity remains confined to Halema'uma'u Crater in Hawai'i Volcanoes National Park, and there is no sign of migrating activity elsewhere on Kīlauea.
The rapid deflationary trend began yesterday, December 20, 2021 around 11 a.m. and subsided early on December 21. The volcanic tremor associated with the eruption has practically ceased and the seismic activity remains below the background noise.

The surface of the lake became crusted after a sequence of partial overturns last night. The lake has experienced a total elevation of around 69 meters since lava emerged on September 29. The total erupting volume since the start of the eruption was estimated to be around 30 million cubic meters on November 16.

 

Source: HVO Daily Report

Kilauea - Halema'uma'u - active vent on 12.20.2021 - photo S. Carr - HVO

Kilauea - Halema'uma'u - active vent on 12.20.2021 - photo S. Carr - HVO

Kilauea - Halema'uma'u - crust over the lava lake on 12.21.2021 - HVO webcam

Kilauea - Halema'uma'u - crust over the lava lake on 12.21.2021 - HVO webcam

In the Reykjanes Peninsula, the earthquakes are aligned with the SW-NE direction, directly above the intrusion that caused the eruption earlier this year. The activity has recently moved south. The main activity last night was in Litla Hrút, but now appears to be south of the Geldingadalur eruption sites.

These earthquakes all appear to be at a relatively great depth, they are all at a depth of around 6-7 kilometers, according to volcanologist Þorvaldur Þórðarson.

The most important earthquake of M4.9 took place on December 22 at 10 a.m.

 

General seismic cracks on the Reykjanes Peninsula align with the N-S direction and are connected to the boundaries of the plates that cross the peninsula. The rows of craters and intrusions on the Reykjanes Peninsula, on the other hand, are almost always laid out in this diagonal fashion.

There is some uncertainty as to what scenarios can occur, but one of the scenarios is that magma can rise to the surface quite quickly.

 

Source: IMO

Reykjanes Peninsula - seismic swarm - location and magnitude of earthquakes as of 23.12.2021 / 07:10 - Doc. IMO
Reykjanes Peninsula - seismic swarm - location and magnitude of earthquakes as of 23.12.2021 / 07:10 - Doc. IMO
Reykjanes Peninsula - seismic swarm - location and magnitude of earthquakes as of 23.12.2021 / 07:10 - Doc. IMO

Reykjanes Peninsula - seismic swarm - location and magnitude of earthquakes as of 23.12.2021 / 07:10 - Doc. IMO

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