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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
Piton de La Fournaise - the Dolomieu , Bory et Maillard craters - photo archives © Bernard Duyck 2017 - one click to enlarge

Piton de La Fournaise - the Dolomieu , Bory et Maillard craters - photo archives © Bernard Duyck 2017 - one click to enlarge

The seismic crisis that began on September 7 at 4:54 p.m. local time ended in the evening (around 7 p.m. local time). This seismic crisis was accompanied by weak deformation at the summit (< 1 cm), according to the Volcanological Observatory of Piton de la Fournaise.

The cessation of the seismic crisis means that the progression of magma has ceased at depth (intrusion) below the summit and has not reached the surface.

Since then, seismicity has remained sustained with 2 or 3 earthquakes recorded per hour.

Piton de La Fournaise -: Location map (epicentres) and northwest - southeast and southwest - northeast sections (showing the location in depth, hypocentres) of the earthquakes recorded and located by the OVPF-IPGP on September 7 under Reunion. Only localizable earthquakes have been shown on the map. The observatory records seismic events not represented on this map because they cannot be located, due to their too low magnitude - Doc. OVPF

Piton de La Fournaise -: Location map (epicentres) and northwest - southeast and southwest - northeast sections (showing the location in depth, hypocentres) of the earthquakes recorded and located by the OVPF-IPGP on September 7 under Reunion. Only localizable earthquakes have been shown on the map. The observatory records seismic events not represented on this map because they cannot be located, due to their too low magnitude - Doc. OVPF

No hypothesis is ruled out (permanent cessation of seismicity, resumption of intrusion, new intrusion) as to the evolution of the future situation given this persistent seismicity.

In the past such intrusions have sometimes preceded the final injection of magma leading to the eruption by a few days, as was recently observed in October 2019 and December 2020.

Alert level 1 is maintained. As a result, public access to the entire Piton de la Fournaise enclosure, whether from the Pas de Bellecombe trail or from any other trail, is prohibited until further notice.

 

The seismology of September 7 is characterized by:

- Number of landslides on 07-09-2022: 10
Areas affected by landslides: Summit cone and Enclosure

- Number of volcano-tectonic earthquakes (VT) of 07-09-2022: 307
Area concerned by the VTs: Summit cone - The earthquakes were located on the northern edge of the Dolomieu crater.

- Volcano-tectonic earthquake of greater magnitude of 07-09-2022: Duration: 10.52 s - Duration magnitude: 1.17

- Number of local earthquakes (outside the Piton de la Fournaise massif) of 07-09-2022: 4

 

Sources: OVPF communication September 08, 2022 – 8:00 a.m. (local time) – 4:00 a.m. (UTC time) & daily bulletin.

Find all the information relating to the activity of Piton de la Fournaise on the various OVPF-IPGP media: - the website: ipgp.fr/fr/ovpf/actualites-ovpf - the Twitter account: twitter. com/obsfournaise - the Facebook account: facebook.com/ObsVolcanoPitonFournaise

Sangay – 07.09.2022 at sunrise, we can see the traces of incandescent material that fell from its face without snow during the night – Eqphos_photography via Volcan Sangay Facebook - one click to enlarge

Sangay – 07.09.2022 at sunrise, we can see the traces of incandescent material that fell from its face without snow during the night – Eqphos_photography via Volcan Sangay Facebook - one click to enlarge

The level of activity in Sangay, in Ecuador, remains high both internally and on the surface from 06 to 07 September / 11 a.m.
Seismicity is characterized by Explosion (EXP) 446, Long Period (LP) 9, Emission Quake (TREMI) 66
VAAC Washington reported 3 emission alerts, with a maximum height of 1,770 m above crater level, in a westerly direction. The area is mostly cloudy today, there are no observations from
on the surface.
Alert level - SNGRE: Yellow

 

Sources: IGEPN & Volcan Sangay FB

Marapi / Sumatra - photo archives PVMBG - one click to enlarge

Marapi / Sumatra - photo archives PVMBG - one click to enlarge

In a special notice issued on September 2, PVMBG reported that tiltmeter deformation data for Marapi Volcano in Central Sumatra showed a trend of summit inflation and deflation along the flanks.

Seismicity continued to fluctuate with the dominant signal indicating hydrothermal activity. A phreatic eruption was the most likely type of volcanic activity that could occur at the volcano, based on recent data, and it could occur without warning.

The PVMBG reminded the public to stay at least 3 km from the summit. The alert level remained at 2 (on a scale of 1 to 4).

 

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) via GVP

Semeru - a thinning reveals the summit on 05.09.2022 / 07:44 - webcam MSJ-BPBD-CCTV - one click to enlarge

Semeru - a thinning reveals the summit on 05.09.2022 / 07:44 - webcam MSJ-BPBD-CCTV - one click to enlarge

The activity of Semeru, on the island of Java, was maintained between August 31 and September 06, according to the PVMBG.

The seismicity of the week is characterized by:
- 567 eruption earthquakes
- 3 collapse earthquakes
- 17 emission earthquakes
- 1 volcanic earthquake
- 1 episode of harmonic tremor.

Activity level remains at 3/siaga, with recommendations
- to carry out no activity in the southeastern sector along Besuk Kobokan, up to 13 km from the summit (the center of the eruption). Outside of this distance, the community does not conduct activities within 500 meters of the bank (river edge) along Besuk Kobokan due to the potential for expansion from hot clouds and lava flows. at a distance of 17 km from the summit.
- not to move within a radius of 5 km from the crater / summit of Mount Semeru because it is subject to the danger of stone throwing (incandescent).

 

Source: PVMBG

Semeru - summary of activity between August 31 and September 06, 2022 - Doc. PVMBG

Semeru - summary of activity between August 31 and September 06, 2022 - Doc. PVMBG

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